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Sample records for chromatography thin layer

  1. Modern Thin-Layer Chromatography.

    Science.gov (United States)

    Poole, Colin F.; Poole, Salwa K.

    1989-01-01

    Some of the important modern developments of thin-layer chromatography are introduced. Discussed are the theory and instrumentation of thin-layer chromatography including multidimensional and multimodal techniques. Lists 53 references. (CW)

  2. High Performance Thin Layer Chromatography.

    Science.gov (United States)

    Costanzo, Samuel J.

    1984-01-01

    Clarifies where in the scheme of modern chromatography high performance thin layer chromatography (TLC) fits and why in some situations it is a viable alternative to gas and high performance liquid chromatography. New TLC plates, sample applications, plate development, and instrumental techniques are considered. (JN)

  3. Thin Layer Chromatography (TLC) of Chlorophyll Pigments.

    Science.gov (United States)

    Foote, Jerry

    1984-01-01

    Background information, list of materials needed, procedures used, and discussion of typical results are provided for an experiment on the thin layer chromatography of chlorophyll pigments. The experiment works well in high school, since the chemicals used are the same as those used in paper chromatography of plant pigments. (JN)

  4. Christhin: Quantitative Analysis of Thin Layer Chromatography

    CERN Document Server

    Barchiesi, Maximiliano; Renaudo, Carlos; Rossi, Pablo; Pramparo, María de Carmen; Nepote, Valeria; Grosso, Nelson Ruben; Gayol, María Fernanda

    2012-01-01

    Manual for Christhin 0.1.36 Christhin (Chromatography Riser Thin) is software developed for the quantitative analysis of data obtained from thin-layer chromatographic techniques (TLC). Once installed on your computer, the program is very easy to use, and provides data quickly and accurately. This manual describes the program, and reading should be enough to use it properly.

  5. Thin-Layer Chromatography: Four Simple Activities for Undergraduate Students.

    Science.gov (United States)

    Anwar, Jamil; And Others

    1996-01-01

    Presents activities that can be used to introduce thin-layer chromatography at the undergraduate level in relatively less developed countries and that can be performed with very simple and commonly available apparati in high schools and colleges. Activities include thin-layer chromatography with a test-tube, capillary feeder, burette, and rotating…

  6. Thin-Layer and Paper Chromatography.

    Science.gov (United States)

    Sherma, Joseph; Fried, Bernard

    1984-01-01

    Reviews literature on chromatography examining: books, reviews, student experiments; chromatographic systems, techniques, apparatus; detecting and identification of separated zones; preparative chromatography and radiochromatography; and applications related to specific materials (such as acids, alcohols, amino acids, antibiotics, enzymes, dyes,…

  7. A Thin Layer Chromatography Laboratory Experiment of Medical Importance

    Science.gov (United States)

    Sharma, Loretta; Desai, Ankur; Sharma, Ajit

    2006-01-01

    A thin layer chromatography experiment of medical importance is described. The experiment involves extraction of lipids from simulated amniotic fluid samples followed by separation, detection, and scanning of the lecithin and sphingomyelin bands on TLC plates. The lecithin-to-sphingomyelin ratio is calculated. The clinical significance of this…

  8. Thin-Layer Chromatography: The "Eyes" of the Organic Chemist

    Science.gov (United States)

    Dickson, Hamilton; Kittredge, Kevin W.; Sarquis, Arlyne

    2004-01-01

    Thin-layer chromatography (TLC) methods are successfully used in many areas of research and development such as clinical medicine, forensic chemistry, biochemistry, and pharmaceutical analysis as TLC is relatively inexpensive and has found widespread application as an easy to use, reliable, and quick analytic tool. The usefulness of TLC in organic…

  9. 21 CFR 862.2270 - Thin-layer chromatography system for clinical use.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Thin-layer chromatography system for clinical use... Instruments § 862.2270 Thin-layer chromatography system for clinical use. (a) Identification. A thin-layer... a mixture. The mixture of compounds is absorbed onto a stationary phase or thin layer of...

  10. Separation of zirconium by thin-layer chromatography.

    Science.gov (United States)

    Oguma, K

    1969-03-01

    The thin-layer Chromatographie separation of a number of metal ions [Sc, Y, Zr, La, Sm, Th, U(VI), etc.] with solvent mixtures of mesityl oxide, ethanol and 5M nitric acid on silica gel-cellulose (5:1) thin-layer plates is reported. Zirconium remains stationary whilst the other metal ions move with the solvent, thus allowing a selective separation of zirconium from about 20 metal ions in ratios ranging from 100:1 to 1:100. Mixtures of various metal ions can also be separated.

  11. Phytochemical analysis of ethanolic extract of Dichrostachys Cinerea W and Arn leaves by a thin layer chromatography, high performance thin layer chromatography and column chromatography

    OpenAIRE

    Vijayalakshmi, M; K Periyanayagam; Kavitha, K; K Akilandeshwari

    2013-01-01

    Background: The leaves of Dichrostachys cinerea are used as laxative, diuretic, painkiller. It is also used in the treatment of gonorrhoea, boils, oedema, gout, veneral diseases and nasopharyngeal affections, etc. Materials and Methods: The Phytochemical investigation of ethanolic extract of D. cinerea leaves were performed by standard chemical tests, thin layer chromatography (TLC) by using various solvent systems, and by high performance liquid chromatography (HPTLC). Two compounds were...

  12. High performance thin layer chromatography profile of Cassytha filiformis

    Institute of Scientific and Technical Information of China (English)

    Mythili Sathiavelu; Sathiavelu Arunachalam

    2012-01-01

    Objective: To study the phenols, flavonoids, saponin profile of the medicinal plant Cassytha filiformis (C. filiformis) using high performance thin layer chromatography (HPTLC). Methods:The extracts were tested to determine the presence of various phytochmeicals like alkaloids, phenolic compounds, flavonoids, carbohydrates, glycosides, saponins, terpenoids, tannins, fixed oils, fats and protein and aminoacids (Harborne and Harborne, 1998). HPTLC studies were carried out by Harborne and Wagner et al method. Different compositions of the mobile phase for HPTLC analysis were tested in order to obtain high resolution and reproducible peaks. Results: The results of the preliminary phytochemical studies confirm the presence of phenols, alkaloids, carbohydrates, saponins, flavanoids, terpenoids and tannins in the methanolic extracts of C. filiformis. The methanolic extracts of C. filiformis displayed the presence of 13 types of phenolic substances with 13 different Rf values ranging from 0.01 to 0.96. The results illustrated the presence of 9 different types of flavonoides with 9 different Rf values ranging from 0.01 to 0.97. The results of HPTLC analysis of saponins demonstrated the presence of 11 different types of saponins with 11 different Rf values ranging from 0.04 to 0.92. Conclusions: In the present study we observed the phenols, flavonoids, saponin profile of the medicinal plant C. filiformis using high performance thin layer chromatography (HPTLC). Hence it was concluded that the phenolic compounds present in the methonolic extract could be responsible for antioxidant activities. Plant derived antioxidants, especially phenols and flavonoids, have been described to have various properties like anticancer, antiaging and prevention of cardiovascular diseases. Furthur, separation and characterization of the bioactive compound from the plant is to be evaluated and reported in near future.

  13. [Use of column and thin layer chromatography for detection of vanillyl mandelic acid in urine].

    Science.gov (United States)

    Riabichenko, V V; Barchukov, V G; Chernyĭ, A V; Salenko, Iu A

    2002-03-01

    The excretion of vanillylmandelic acid was measured by column chromatography of urinary samples on aluminum oxide with subsequent thin-layer chromatography on silica gel. Use of aluminum oxide allowed application of greater urine samples (up to 0.1% of 24-h diuresis) onto chromatographic plates and essentially improved the quality of separation of vanillylmandelic acid from other phenylcarbonic acids by thin-layer chromatography, as well as the specificity and reproducibility of measurements.

  14. Thin layer chromatography-ion mobility spectrometry (TLC-IMS).

    Science.gov (United States)

    Ilbeigi, Vahideh; Tabrizchi, Mahmoud

    2015-01-06

    Ion mobility spectrometry (IMS) is a fast and sensitive analytical method which operates at the atmospheric pressure. To enhance the capability of IMS for the analysis of mixtures, it is often used with preseparation techniques, such as GC or HPLC. Here, we report for the first time the coupling of the thin-layer chromatography and IMS. A variety of coupling schemes were tried that included direct electrospray from the TLC strip tip, indirect electrospray from a needle connected to the TLC strip, introducing the moving solvent into the injection port, and, the simplest way, offline introduction of scratched or cut pieces of strips into the IMS injection port. In this study a special solvent tank was designed and the TLC strip was mounted horizontally where the solvent would flow down. A very small funnel right below the TLC tip collected the solvent and transferred it to a needle via a capillary tubing. Using the TLC-ESI-IMS technique, acceptable separations were achieved for two component mixtures of morphine-papaverine and acridine-papaverine. A special injection port was designed to host the pieces cut off the TLC. The method was successfully used to identify each spot on the TLC by IMS in a few seconds.

  15. Isolation of Three Components from Spearmint Oil: An Exercise in Column and Thin-Layer Chromatography

    Science.gov (United States)

    Davies, Don R.; Johnson, Todd M.

    2007-01-01

    A simple experiment for undergraduate organic chemistry students to separate a colorless mixture using column chromatography and then monitor the outcome of the separation using thin-layer chromatography (TLC) and infrared spectroscopy(IR) is described. The experiment teaches students the principle and techniques of column and thin-layer…

  16. Normal and Reversed-Phase Thin Layer Chromatography of Green Leaf Extracts

    Science.gov (United States)

    Sjursnes, Birte Johanne; Kvittingen, Lise; Schmid, Rudolf

    2015-01-01

    Introductory experiments of chromatography are often conducted by separating colored samples, such as inks, dyes, and plant extracts, using filter paper, chalk, or thin layer chromatography (TLC) plates with various solvent systems. Many simple experiments have been reported. The relationship between normal chromatography and reversed-phase…

  17. Peak broadening in paper chromatography and related techniques : III. Peak broadening in thin-layer chromatography on cellulose powder

    NARCIS (Netherlands)

    Ligny, C.L. de; Remijnse, A.G.

    1968-01-01

    The mechanism of peak broadening in thin-layer chromatography on cellulose powder was investigated by comparing the peak widths obtained in chromatography with those caused only by diffusion in the cellulose powder, for a set of amino acids of widely differing RF values and six kinds of cellulose po

  18. The weight of flash chromatography: A tool to predict its mass intensity from thin-layer chromatography

    Directory of Open Access Journals (Sweden)

    Freddy Pessel

    2016-11-01

    Full Text Available Purification by flash chromatography strongly impacts the greenness of a process. Unfortunately, due to the lack of the relevant literature data, very often this impact cannot be assessed thus preventing the comparison of the environmental factors affecting the syntheses. We developed a simple mathematical approach to evaluate the minimum mass intensity of flash chromatography from the retention factor values determined by thin-layer chromatography.

  19. Simultaneous determination of cyclodol and diprazin by thin layer chromatography and high performance liquid chromatography.

    Science.gov (United States)

    Makharadze, R; Adeishvili, L; Chelidze, T; Imnadze, N; Nizharadze, N

    2009-11-01

    Ciklodol (trihexyphenidil)--the central and peripheral m-cholinoblocker is currently used with other antipsychotic drugs such as phenotiazines and tricycle antidepressants. For the purpose of simultaneous determination of ciklodol and diprazine, were selected two methods of analysis: Thin Layer Chromatography (TLC) and High Performance Liquid Chromatography (HPLC). During development of TLC method was studied the 10 visualizing system and 24 mobile systems. For individual or simultaneous determination of ciklodol and diprazine were recommended the following solvents' systems: 1. Toluene-acetone-ethanole-25%NH(4)OH (45:45: 7.5:2.5), 2. Hexane-ethyl acetate (15:5), 3. Chloroform-heptene-25%NH(4)OH (16:3:3), 4. Ethylacetate-hexane (10:10), 5. Acetonitrile-metanol (10:10) and 6.Heptene-chloroform-ethanol-25% NH(4)OH (5:10:3:1). As visualizing systems were chosen: Iodine vapors, blacklight (UV254) and reagent of FNP. Reagent of FNP gives colored spot just with diprazine and it is also could be used for separation of both objects in simultaneous analysis. Developed HPLC method of simultaneous determination of ciklodol and diprazine: like mobile phase is recommended: Acetonitril- 0.05M KH(2)PO4 (55:45) (v/v) +H(3)PO(4) (pH3.5), column EC250 x 4.6mm, with solid phase Nucleosil, flow rate 1ml/min, sample volume 40 microl. In given conditions, the retention time of ciklodol is 6.005min and diprazine 7.227min. Developed method of simultaneous determination and separation of ciklodol and diprazine in respective mixtures could be successfully applied as in the pharmaceutical, as well in the chemical-toxicological laboratories.

  20. Phospholipids, Dietary Supplements, and Chicken Eggs: An Inquiry-Based Exercise Using Thin-Layer Chromatography

    Science.gov (United States)

    Potteiger, Sara E.; Belanger, Julie M.

    2015-01-01

    This inquiry-based experiment is designed for organic or biochemistry undergraduate students to deduce the identity of phospholipids extracted from chicken eggs and dietary supplements. This is achieved using thin-layer chromatography (TLC) data, a series of guided questions of increasing complexity, and provided relative retention factor (Rf)…

  1. Analysis of Peppermint Leaf and Spearmint Leaf Extracts by Thin-Layer Chromatography

    Science.gov (United States)

    Pelter, Libbie S. W.; Amico, Andrea; Gordon, Natalie; Martin, Chylah; Sandifer, Dessalyn; Pelter, Michael W.

    2008-01-01

    In this inquiry-based activity, the usefulness of thin-layer chromatography (TLC) to visualize the difference between spearmint and peppermint is explored. The experiment may be used in any class where TLC is discussed from high school to college. We have used this activity with science majors in an organic chemistry laboratory, with non-science…

  2. Analysis and Identification of Acid-Base Indicator Dyes by Thin-Layer Chromatography

    Science.gov (United States)

    Clark, Daniel D.

    2007-01-01

    Thin-layer chromatography (TLC) is a very simple and effective technique that is used by chemists by different purposes, including the monitoring of the progress of a reaction. TLC can also be easily used for the analysis and identification of various acid-base indicator dyes.

  3. A Simple and Inexpensive Capillary Holder for Thin-Layer Chromatography

    Science.gov (United States)

    Pintea, Beniamin-Nicolae V.

    2011-01-01

    Thin-layer chromatography (TLC) is a widely used method of qualitative analysis in organic synthesis, as it uniquely combines low cost, rapidity, simplicity, versatility, small quantities of sample and low detection limits. The simplest and most economical method for the application of samples onto TLC plates is by hand, using glass capillaries.…

  4. Evaluating Mechanisms of Dihydroxylation by Thin-Layer Chromatography: A Microscale Experiment for Organic Chemistry

    Science.gov (United States)

    Burlingham, Benjamin T.; Rettig, Joseph C.

    2008-01-01

    A microscale experiment is presented in which cyclohexene is dihydroxylated under three sets of conditions: epoxidation-hydrolysis, permanganate oxidation, and the Woodward dihydroxylation. The products of the reactions are determined by the use of thin-layer chromatography. Teams of students are presented with proposed mechanisms for each…

  5. Digitally Enhanced Thin-Layer Chromatography: An Inexpensive, New Technique for Qualitative and Quantitative Analysis

    Science.gov (United States)

    Hess, Amber Victoria Irish

    2007-01-01

    A study conducted shows that if digital photography is combined with regular thin-layer chromatography (TLC), it could perform highly improved qualitative analysis as well as make accurate quantitative analysis possible for a much lower cost than commercial equipment. The findings suggest that digitally enhanced TLC (DE-TLC) is low-cost and easy…

  6. Development of optimized mobile phases for protein separation by high performance thin layer chromatography.

    Science.gov (United States)

    Biller, Julia; Morschheuser, Lena; Riedner, Maria; Rohn, Sascha

    2015-10-09

    In recent years, protein chemistry tends inexorably toward the analysis of more complex proteins, proteoforms, and posttranslational protein modifications. Although mass spectrometry developed quite fast correspondingly, sample preparation and separation of these analytes is still a major issue and quite challenging. For many years, electrophoresis seemed to be the method of choice; nonetheless its variance is limited to parameters such as size and charge. When taking a look at traditional (thin-layer) chromatography, further parameters such as polarity and different mobile and stationary phases can be utilized. Further, possibilities of detection are manifold compared to electrophoresis. Similarly, two-dimensional separation can be also performed with thin-layer chromatography (TLC). As the revival of TLC developed enormously in the last decade, it seems to be also an alternative to use high performance thin-layer chromatography (HPTLC) for the separation of proteins. The aim of this study was to establish an HPTLC separation system that allows a separation of protein mixtures over a broad polarity range, or if necessary allowing to modify the separation with only few steps to improve the separation for a specific scope. Several layers and solvent systems have been evaluated to reach a fully utilized and optimized separation system.

  7. Thin-layer chromatography and colorimetric analysis of multi-component explosive mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Pagoria, Philip F.; Mitchell, Alexander R.; Whipple, Richard E.; Carman, M. Leslie

    2014-08-26

    A thin-layer chromatography method for detection and identification of common military and peroxide explosives in samples includes the steps of provide a reverse-phase thin-layer chromatography plate; prepare the plate by marking spots on which to deposit the samples by touching the plate with a marker; spot one micro liter of a first standard onto one of the spots, spot one micro liter of a second standard onto another of the spots, and spot samples onto other of spots producing a spotted plate; add eluent to a developing chamber; add the spotted plate to the developing chamber; remove the spotted plate from the developing chamber producing a developed plate; place the developed plate in an ultraviolet light box; add a visualization agent to a dip tank; dip the developed plate in the dip tank and remove the developed plate quickly; and detect explosives by viewing said developed plate.

  8. Analysis of biodiesel conversion using thin layer chromatography and nonlinear calibration curves

    DEFF Research Database (Denmark)

    Fedosov, Sergey; Brask, Jesper; Xu, Xuebing

    2011-01-01

    acquisition of a large body of data. The two well-established methods of gas chromatography (GC) and HPLC are time consuming and expensive when analyzing multiple samples. Additionally, it is not always possible to record all the reactants on one elution profile. We examined applicability of thin layer...... chromatography (TLC) for this purpose, where the detection was based on either flame ionization detector (FID) or a modified staining procedure. The suggested staining method gave no background and appeared well suited for quantitative analysis. The relevant calibrations are presented, and the general principles...

  9. A reversed-phase compatible thin-layer chromatography autography for the detection of acetylcholinesterase inhibitors.

    Science.gov (United States)

    Ramallo, I Ayelen; García, Paula; Furlan, Ricardo L E

    2015-11-01

    A dual readout autographic assay to detect acetylcholinesterase inhibitors present in complex matrices adsorbed on reversed-phase or normal-phase thin-layer chromatography plates is described. Enzyme gel entrapment with an amphiphilic copolymer was used for assay development. The effects of substrate and enzyme concentrations, pH, incubation time, and incubation temperature on the sensitivity and the detection limit of the assay were evaluated. Experimental design and response surface methodology were used to optimize conditions with a minimum number of experiments. The assay allowed the detection of 0.01% w/w of physostigmine in both a spiked Sonchus oleraceus L. extract chromatographed on normal phase and a spiked Pimenta racemosa (Mill.) J.W. Moore leaf essential oil chromatographed on reversed phase. Finally, the reversed-phase thin-layer chromatography assay was applied to reveal the presence of an inhibitor in the Cymbopogon citratus (DC.) Stapf essential oil. The developed assay is able to detect acetylcholinesterase inhibitors present in complex matrixes that were chromatographed in normal phase or reversed-phase thin-layer chromatography. The detection limit for physostigmine on both normal and reversed phase was of 1×10(-4) μg. The results can be read by a change in color and/or a change in fluorescence.

  10. Qualitative analysis of Cu2+, Co2+, and Ni2+ cations using thin-layer chromatography.

    Science.gov (United States)

    Ergül, Soner

    2004-03-01

    The M(DEDTC)2 (M = Cu, Co, or Ni) and M(PyDTC)2 (M = Cu or Co) complexes prepared by reactions of sodium diethyldithiocarbamate and ammonium pyrollidinedithiocarbamate with metal (II) nitrates are examined for qualitative analysis and separation using thin-layer chromatography systems. These complexes and their mixtures are spotted to the activated thin layers of silica gel 60GF254 (Si-60GF254) with a 250-microm thickness. Pure toluene and a toluene-cyclohexane mixture (3:1, v/v) are used as mobile phases for running of the complexes. These chromatographic systems are successfully used for qualitative analysis of corresponding metal cations and separation of components in both M(DEDTC)2 and M(PyDTC)2 complex mixtures.

  11. Analyzing salvia divinorum and its active ingredient salvinorin a utilizing thin layer chromatography and gas chromatography/mass spectrometry.

    Science.gov (United States)

    Jermain, John D; Evans, Hiram K

    2009-05-01

    In recent years, Salvia divinorum has become a major focus by state legislatures throughout the United States looking to prohibit the sale of the psychoactive plant. After researching testing procedures presented in the literature and those employed by crime laboratories throughout the country, it was decided that thin layer chromatography (TLC) and gas chromatography/mass spectrometry (GC/MS) were the methods to use to analyze plant material for salvinorin A. With TLC, salvinorin A was detected from extracted plant material and was easily distinguishable from 13 other Salvia species as well as Cannabis sativa L. (marijuana). When using GC/MS, salvinorin A was best extracted from plant material with chloroform at ambient temperature when using a nonpolar solvent and acetone at ambient temperature when using a polar solvent. By utilizing these techniques, criminalists are now able to confirm the presence of salvinorin A in a submitted plant material suspected to be Salvia divinorum.

  12. EVALUATION OF FOOD COLOR CONSUMPTION AND DETERMINING COLOR TYPE BY THIN LAYER CHROMATOGRAPHY

    OpenAIRE

    Fereshteh Farzianpour; Gholamreza Jahead Khaniki; Masoud Younesian; Bahman Banaei Ghahferkhi; Mehraban Sadeghi; Shayan Hosseini

    2013-01-01

    The aim of this research was to investigate the role of the social demographic parameters of the people in charge of the facilities producing pastry, poolak (a type of coin-shaped candy) and rock candy in the consumption of food colors and to determine color type by thin layer chromatography in Shahr-e-kord city in 2011. This research was an interventional-analytical study and its target population is the people in charge of the facilities producing pastry, poolak and rock candy in Shahr-e-ko...

  13. EVALUATION OF FOOD COLOR CONSUMPTION AND DETERMINING COLOR TYPE BY THIN LAYER CHROMATOGRAPHY

    Directory of Open Access Journals (Sweden)

    Fereshteh Farzianpour

    2013-01-01

    Full Text Available The aim of this research was to investigate the role of the social demographic parameters of the people in charge of the facilities producing pastry, poolak (a type of coin-shaped candy and rock candy in the consumption of food colors and to determine color type by thin layer chromatography in Shahr-e-kord city in 2011. This research was an interventional-analytical study and its target population is the people in charge of the facilities producing pastry, poolak and rock candy in Shahr-e-kord city. Social demographic data of the participants were collected using checklists and 720 samples of pastry, poolak and rock candy weighing at least 250 gr were randomly taken over a period of 10 months. With respect to color additives, the samples were analyzed by Thin Layer Chromatography (TLC in four groups: natural colors permitted artificial colors, forbidden artificial colors and without colors. 48.47% contained food color and 6.52% contained forbidden artificial food color. Sunset Yellow was the color the most consumed among the colors used. Regarding the results obtained, there is a high rate of consumption of artificial colors (41.22%, sunset Yellow being the most consumed. Therefore, it is of great importance to raise the awareness and change the attitude of the people in charge in these jobs as well as the consumers with regard to the side effects of artificial colors, which can be done through the mass media and NGOs.

  14. Two-dimensional thin-layer chromatography for the specific detection of hippurate hydrolysis by microorganisms.

    Science.gov (United States)

    Lin, J Y; Chen, K C; Hale, J; Totten, P A; Holmes, K K

    1986-01-01

    Glycine, one of the end products of hippurate hydrolysis by microorganisms, was detected by a rapid, specific technique utilizing two-dimensional thin-layer chromatography. A loopful of growth of each organism from its suitable agar medium was washed, suspended, and incubated with 0.1% sodium hippurate for 30 min at 37 degrees C. The supernatant of the incubated suspension from each organism was then dansylated, and the dansyl derivatives were separated by two-dimensional thin-layer chromatography on polyamide sheets. Glycine, a product of hippurate hydrolysis, was detected under UV light. This technique does not require prolonged incubation and was found to be more specific and reliable than the standard ninhydrin reaction. In addition, it is inexpensive and can be easily conducted in a clinical microbiological reference laboratory. By this method, 100% (22/22) of Campylobacter jejuni and 0% (0/9) of Campylobacter coli reference strains were positive. In addition, 100% (13/13) of group B streptococci, 100% (24/24) of group D streptococci, and 90% (18/20) of Gardenerella vaginalis clinical isolates were positive for hippurate hydrolysis. This method is useful for the identification to the species level of Campylobacter organisms and the biotyping of Gardnerella organisms and for the detection of hippurate hydrolysis by unknown microorganisms. Images PMID:3517036

  15. Two-dimensional thin-layer chromatography in the analysis of secondary plant metabolites.

    Science.gov (United States)

    Cieśla, Lukasz; Waksmundzka-Hajnos, Monika

    2009-02-13

    Drugs, derived from medicinal plants, have been enjoying a renaissance in the last years. It is due to a great pharmacological potential of herbal drugs, as many natural compounds have been found to exhibit biological activity of wide spectrum. The introduction of whole plants, plant extracts, or isolated natural compounds has led to the need to create the analytical methods suitable for their analysis. The identification of isolated substances is relatively an easy task, but the analysis of plant extracts causes a lot of problems, as they are usually very complex mixtures. Chromatographic methods are one of the most popular techniques applied in the analysis of natural mixtures. Unfortunately the separation power of traditional, one-dimensional techniques, is usually inadequate for separation of more complex samples. In such a case the use of multidimensional chromatography is advised. Planar chromatography gives the possibility of performing two-dimensional separations with the use of one adsorbent with two different eluents or by using bilayer plates or graft thin-layer chromatography (TLC) technique; combinations of different multidimensional techniques are also possible. In this paper, multidimensional planar chromatographic methods, commonly applied in the analysis of natural compounds, were reviewed. A detailed information is given on the methodology of performing two-dimensional separations on one adsorbent, on bilayer plates, with the use of graft TLC and hyphenated methods. General aspects of multidimensionality in liquid chromatography are also described. Finally a reader will find a description of variable two-dimensional methods applied in the analysis of compounds, most commonly encountered in plant extracts. This paper is aimed to draw attention to the potential of two-dimensional planar chromatography in the field of phytochemistry. It may be useful for those who are interested in achieving successful separations of multicomponent mixtures by means

  16. Thin layer chromatography coupled to paper spray ionization mass spectrometry for cocaine and its adulterants analysis.

    Science.gov (United States)

    De Carvalho, Thays C; Tosato, Flavia; Souza, Lindamara M; Santos, Heloa; Merlo, Bianca B; Ortiz, Rafael S; Rodrigues, Rayza R T; Filgueiras, Paulo R; França, Hildegardo S; Augusti, Rodinei; Romão, Wanderson; Vaz, Boniek G

    2016-05-01

    Thin layer chromatography (TLC) is a simple and inexpensive type of chromatography that is extensively used in forensic laboratories for drugs of abuse analysis. In this work, TLC is optimized to analyze cocaine and its adulterants (caffeine, benzocaine, lidocaine and phenacetin) in which the sensitivity (visual determination of LOD from 0.5 to 14mgmL(-1)) and the selectivity (from the study of three different eluents: CHCl3:CH3OH:HCOOHglacial (75:20:5v%), (C2H5)2O:CHCl3 (50:50v%) and CH3OH:NH4OH (100:1.5v%)) were evaluated. Aiming to improve these figures of merit, the TLC spots were identified and quantified (linearity with R(2)>0.98) by the paper spray ionization mass spectrometry (PS-MS), reaching now lower LOD values (>1.0μgmL(-1)). The method developed in this work open up perspective of enhancing the reliability of traditional and routine TLC analysis employed in the criminal expertise units. Higher sensitivity, selectivity and rapidity can be provided in forensic reports, besides the possibility of quantitative analysis. Due to the great simplicity, the PS(+)-MS technique can also be coupled directly to other separation techniques such as the paper chromatography and can still be used in analyses of LSD blotter, documents and synthetic drugs.

  17. Thin-Layer Chromatography: Comparative Estimation of Soil’s Atrazine

    Directory of Open Access Journals (Sweden)

    Vijay Kumar

    2013-12-01

    Full Text Available Herbicide atrazine is a broad spectrum herbicide, used worldwide to protect the crops from weeds, but overuse of atrazine have caused the huge environmental problems from few decades. So it is very essential to study and develop the lab based analytical methods, which are important for the detection of atrazine in environment as well as in biological media. In this study we have collected the soils samples from farm fields and extracted the atrazine by Soxhlet method. Also we have extracted the atrazine from formulated grade considered as standard/pure sample in our study. Both extracted/standard and atrazine samples were characterized by UV and FTIR analysis. Further thin layer chromatography was run to check the purity of soil extracted sample.

  18. Reversed-phase thin-layer chromatography behavior of aldopentose derivatives

    Directory of Open Access Journals (Sweden)

    Malbaša Radomir V.

    2012-01-01

    Full Text Available Quantitative structure-retention relationships (QSRR have been used to study the chromatographic behavior of some aldopentose. The behavior of aldopentose derivatives was investigated by means of the reversed-phase thin-layer chromatography (RP TLC on the silica gel impregnated with paraffin oil stationary phases. Binary mixtures of methanol-water, acetone-water and dioxane-water were used as mobile phases. Retention factors, RM0, corresponding to zero percent organic modifier in the aqueous mobile phase was determined. Lipophilicity C0 was calculated as the ratio of the intercept and slope values. There was satisfactory correlation between them and log P values calculated using different theoretical procedures. Some of these correlations offer very good predicting models, which are important for a better understanding of the relationships between chemical structure and retention. The study showed that the hydrophobic parameters RM0 and C0 can be used as a measures of lipophilicity of investigated compounds.

  19. Random forest models of the retention constants in the thin layer chromatography

    CERN Document Server

    Kursa, Miron B; Rudnicki, Witold R

    2011-01-01

    In the current study we examine an application of the machine learning methods to model the retention constants in the thin layer chromatography (TLC). This problem can be described with hundreds or even thousands of descriptors relevant to various molecular properties, most of them redundant and not relevant for the retention constant prediction. Hence we employed feature selection to significantly reduce the number of attributes. Additionally we have tested application of the bagging procedure to the feature selection. The random forest regression models were built using selected variables. The resulting models have better correlation with the experimental data than the reference models obtained with linear regression. The cross-validation confirms robustness of the models.

  20. Preliminary phytochemical investigation and thin layer chromatography profiling of sequential extracts of Moringa oleifera pods

    Directory of Open Access Journals (Sweden)

    Veena Sharma

    2013-01-01

    Full Text Available Context: Moringa oleifera Lam (Moringaceae is a highly valued plant, distributed in many countries of the tropics and subtropics. It has an impressive range of medicinal uses with high nutritional value. Aim: The present study, primarily aims to carry out a preliminary phytochemical screening so as to detect the major class of compounds present in M. oleifera and to perform thin layer chromatography (TLC profiling of all sequential extracts. Materials and Methods: Phytochemical analysis was performed by various qualitative methods and TLC profiling was carried out using various solvent system of varying polarity. Results and Conclusions: Qualitative phytochemical analysis reflects the presence of phenolics, triterpenoids, cardiac glycosides, steroid, alkaloids and saponin in the plant extract. TLC profiling of the M. oleifera pods was carried out using sequential extracts of petroleum ether, benzene, petroleum ether, benzene, chloroform, ethyl acetate, ethanol and water respectively. The results obtained in the present investigation indicated M. oleifera pods as a rich source of natural antioxidants.

  1. Recent trends in electrospinning of polymer nanofibers and their applications in ultra thin layer chromatography.

    Science.gov (United States)

    Moheman, Abdul; Alam, Mohammad Sarwar; Mohammad, Ali

    2016-03-01

    Fabrication of polymer derived electrospun nanofibers by electrospinning as chromatographic sorbent bed for ultra-thin layer chromatography (UTLC) is a very demanding topic in analytical chemistry. This review presents an overview of recent development in the fabrication of polymer derived electrospun nanofibers and their applications to design UTLC plates as stationary phases for on-plate identification and separation of analytes from their mixture solutions. It has been reported that electrospun fiber based stationary phases in UTLC have enhanced separation efficiency to provide separation of analyte mixture in a shorter development time than those of traditional particle-based TLC stationary phases. In addition, electrospun UTLC is cost effective and can be modified for obtaining different surface selectivities by changing the polymer materials to electrospun devices. Electrospun UTLC plates are not available commercially till date and efforts are being rendered for their commercialization. The morphology and diameter of electrospun nanofibers are highly dependent on several parameters such as type of polymer, polymer molecular weight, solvent, viscosity, conductivity, surface tension, applied voltage, collector distance and flow rate of the polymer solution during electrospinning process. Among the aforementioned parameters, solution viscosity is an important parameter which is mainly influenced by polymer concentration. This review provides evidence for the fabrication of UTLC plates containing electrospun polymer nanofibers. Furthermore, the future prospects related to electrospinning and its application in obtaining of different types of electrospun nanofibers are discussed. The present communication is aimed to review the work which appeared during 2009-2014 on the application of polymer derived electrospun nanofibers in ultra thin layer chromatography.

  2. Differentiation of coloured inks of inkjet printer cartridges by thin layer chromatography and high performance liquid chromatography.

    Science.gov (United States)

    Poon, N L; Ho, S S H; Li, C K

    2005-01-01

    Document examiners are frequently asked to determine whether or not a colour printout has originated from a particular inkjet printer. The printer can rarely be identified unless some unique defects or irregularities of the printer are present on the printout. However, it is possible to decipher the make and/or model of the printer by comparing the ink-profile of the questioned printout with that of a seized inkjet printer cartridge or from one in a database. This paper presents an overview of a systematic approach to characterising and discriminating the inks of different inkjet printer cartridges using thin layer chromatography (TLC) and high pressure liquid chromatography (HPLC) with multi-wavelength ultra-violet/visible (UV/Vis) detection. Ink samples from 23 different inkjet printer cartridges (including originals and substitutes) of different brands and colour printouts, printed by known printers were examined with newly developed chromatographic methods. Subsequently, a database of the ink-profiles was generated. The methods provide a useful tool for discriminating coloured inks in inkjet printer cartridges of different brands.

  3. The laser desorption/laser ionization mass spectra of some methylated xanthines and the laser desorption of caffeine and theophylline from thin layer chromatography plates

    Science.gov (United States)

    Rogers, Kevin; Milnes, John; Gormally, John

    1993-02-01

    Laser desorption/laser ionization time-of-flight mass spectra of caffeine, theophylline, theobromine and xanthine are reported. These mass spectra are compared with published spectra obtained using electron impact ionization. Mass spectra of caffeine and theophylline obtained by IR laser desorption from thin layer chromatography plates are also described. The laser desorption of materials from thin layer chromatography plates is discussed.

  4. A simplified method for rapid quantification of intracellular nucleoside triphosphates by one-dimensional thin-layer chromatography

    DEFF Research Database (Denmark)

    Jendresen, Christian Bille; Kilstrup, Mogens; Martinussen, Jan

    2011-01-01

    -pyrophosphate (PRPP), and inorganic pyrophosphate (PPi) in cell extracts. The method uses one-dimensional thin-layer chromatography (TLC) and radiolabeled biological samples. Nucleotides are resolved at the level of ionic charge in an optimized acidic ammonium formate and chloride solvent, permitting...

  5. Extraction of Nutraceuticals from Spirulina (Blue-Green Alga): A Bioorganic Chemistry Practice Using Thin-layer Chromatography

    Science.gov (United States)

    Herrera Bravo de Laguna, Irma; Toledo Marante, Francisco J.; Luna-Freire, Kristerson R.; Mioso, Roberto

    2015-01-01

    Spirulina is a blue-green alga (cyanobacteria) with high nutritive value. This work provides an innovative and original approach to the consideration of a bioorganic chemistry practice, using Spirulina for the separation of phytochemicals with nutraceutical characteristics via thin-layer chromatography (TLC) plates. The aim is to bring together…

  6. Extraction of nutraceuticals from Spirulina (blue-green alga): A bioorganic chemistry practice using thin-layer chromatography.

    Science.gov (United States)

    Herrera Bravo de Laguna, Irma; Toledo Marante, Francisco J; Luna-Freire, Kristerson R; Mioso, Roberto

    2015-01-01

    Spirulina is a blue-green alga (cyanobacteria) with high nutritive value. This work provides an innovative and original approach to the consideration of a bioorganic chemistry practice, using Spirulina for the separation of phytochemicals with nutraceutical characteristics via thin-layer chromatography (TLC) plates. The aim is to bring together current research, theory, and practice, and always in accordance with pedagogical ideas.

  7. Quantitative Determination of Photosynthetic Pigments in Green Beans Using Thin-Layer Chromatography and a Flatbed Scanner as Densitometer

    Science.gov (United States)

    Valverde, Juan; This, Herve; Vignolle, Marc

    2007-01-01

    A simple method for the quantitative determination of photosynthetic pigments extracted from green beans using thin-layer chromatography is proposed. Various extraction methods are compared, and it is shown how a simple flatbed scanner and free software for image processing can give a quantitative determination of pigments. (Contains 5 figures.)

  8. Indirect fluorometric detection techniques on thin layer chromatography and effect of ultrasound on gel electrophoresis

    Energy Technology Data Exchange (ETDEWEB)

    Yinfa, Ma.

    1990-12-10

    Thin-layer chromatography (TLC) is a broadly applicable separation technique. It offers many advantages over high performance liquid chromatography (HPLC), such as easily adapted for two-dimensional separation, for whole-column'' detection and for handling multiple samples, etc. However, due to its draggy development of detection techniques comparing with HPLC, TLC has not received the attention it deserves. Therefore, exploring new detection techniques is very important to the development of TLC. It is the principal of this dissertation to present a new detection method for TLC -- indirect fluorometric detection method. This detection technique is universal sensitive, nondestructive, and simple. This will be described in detail from Sections 1 through Section 5. Section 1 and 3 describe the indirect fluorometric detection of anions and nonelectrolytes in TLC. In Section 2, a detection method for cations based on fluorescence quenching of ethidium bromide is presented. In Section 4, a simple and interesting TLC experiment is designed, three different fluorescence detection principles are used for the determination of caffeine, saccharin and sodium benzoate in beverages. A laser-based indirect fluorometric detection technique in TLC is developed in Section 5. Section 6 is totally different from Sections 1 through 5. An ultrasonic effect on the separation of DNA fragments in agarose gel electrophoresis is investigated. 262 refs.

  9. The bridge between thin layer chromatography-mass spectrometry and high-performance liquid chromatography-mass spectrometry: The realization of liquid thin layer chromatography-mass spectrometry (LTLC-MS).

    Science.gov (United States)

    Li, Yafeng; Wang, Jianing; Zhan, Lingpeng; Wleklinski, Michael; Wang, Jiyun; Xiong, Caiqiao; Liu, Huihui; Zhou, Yueming; Nie, Zongxiu

    2016-08-19

    The combination of thin layer chromatography (TLC) and mass spectrometry (MS) has been studied for decades, but for most cases MS detection is done after TLC separation is finished. Here, an online simultaneous TLC-MS analysis system, liquid thin layer chromatography-mass spectrometry (LTLC-MS), is developed which successfully synchronize TLC separation process and MS detection process like GC-MS and HPLC-MS do. And there's no need to use specially designed TLC, just regular TLC plates are enough. LTLC-MS method is composed of a newly developed ambient ionization method, glow discharge-matrix assisted infrared desorption ionization (GD-MAIRDI), and forced-flow TLC (FFTLC) technique, which guarantees the MS detection process does not disturb the TLC separation process throughout the whole analysis. The whole LTLC-MS analysis only need two steps and less than 15min. Mixtures as well as the two main components of a pain relief pills have been successfully analyzed by LTLC-MS. This proof of concept study opens up new possibilities of combining TLC with MS, and will further broaden the application abilities of TLC.

  10. [Analysis of phthalates in plastic food-packaging bags by thin layer chromatography].

    Science.gov (United States)

    Chen, Hui; Wang, Yuan; Zhu, Ruohua

    2006-01-01

    The method for simultaneous determination of four phthalates, namely dimethyl phthalate (DMP), diethyl phthalate (DEP), di-n-butyl phthalate (DBP) and di (2-ethylhexyl) phthalate (DEHP) in plastic food-packaging bags by thin layer chromatography (TLC) was developed. The plastic food-packaging bags were extracted with ethanol by ultrasonication, then the mixture was filtrated through membrane (0.45 microm). The mixture of ethyl acetate-anhydrous ether-isooctane (1 : 4 : 15, v/v) was used as developing agent on the TLC silica gel plate for development. The filtered liquid was spotted on the TLC plate dealt by acetone, and detected with scanning wavelength of 275 nm and reference wavelength of 340 nm. The qualitative analysis of the phthalates was performed using the R(f) values of the chromatogram. The quantitative analysis was performed with external standard method. Good linearities were obtained for DMP, DEP, DBP and DEHP. The detection limits were 2.1 ng for DMP, 2.4 ng for DEP, 3.4 ng for DBP and 4.0 ng for DEHP. The relative standard deviations (RSDs) of the four phthalates were 2.8% - 3.5%. The recoveries of the four phthalate standards in real sample were 78.58% - 111.04%. The method presented has the advantages of high precision, high sensitivity, small sample size, and simple pretreatment . The method was used to detect the four phthalates in the food-packaging bags. The contents in real samples were close to the results by gas chromatography.

  11. Data acquisition and processing system for drug release characterization by thin layer chromatography.

    Science.gov (United States)

    Ryoo, J P; Greer, R; Carlson, D

    1989-01-01

    Samples of an antibiotic released from an ocular insert in an in vitro test are characterized by thin layer chromatography (TLC). Conventional characterization methods include cutting and weighing strip chart paper peak profiles obtained with a scanning densitometer for spotted TLC plates, and relating peaks for unknowns to peaks for standards on the basis of relative weights. A data collection and processing system is described in which the data collection and processing is highly automated utilizing a specially developed software program. A Kontes densitometer (Model 800) and a personal computer (IBM PC-AT or Zenith-248) are interfaced using a Keithley 570 data acquisition system. Two BASIC software programs were developed to provide quantitative evaluation of chromatograms of an antibiotic (tylosin tartrate); the first program generates chromatograms on the computer screen through initiating controlled operation of a scanning densitometer for TLC plate analysis, and the second program processes the data providing quantitative analysis of the spectral output through a peak detection and peak integration routine. The approach represents a new general, versatile, quick and effective method to characterize TLC samples for various numbers of peaks for unknowns and standards for different concentration levels.

  12. Screening method for the analysis of polycyclic aromatic hydrocarbons by high performance thin layer chromatography

    Energy Technology Data Exchange (ETDEWEB)

    Butler, H.T.

    1983-01-01

    Investigations were carried out to develop a routine analytical method for the determination of the polycyclic aromatic hydrocarbons (PAH) in environmental samples. The method used high performance thin layer chromatography (HPTLC) for the separation of the PAH's. Densitometric measurements using selective fluorescence detection was employed for the quantitative aspects of the method. High performance silica gel, cellulose, acetylated cellulose and reversed-phase plates as the separation media were evaluated. Reversed-phase plates with 60% silanization and solvent system of methanol:water using continuous multiple developments produced the best separation. The method was evaluated using shale oil, air particulate, diesel exhaust particulate and an in-house dust samples. During the course of the studies a characterization of the fluorescence and single wavelength double beam reflectance modes was performed. Based on observations made during the characterization studies, a calibration method employing a single standard solution was developed. The method had an operating range of approximately 0.5 to 20 ng and is suitable as a scouting technique to determine approximate concentrations of unknown samples in HPTLC. A method for expressing the relative fluorescence intensity of the PAH's at a given excitation wavelength was also developed. The emission response ratios (ERR) were useful in approximating interferences and determining optimal wavelength combinations.

  13. Characterization of drug authenticity using thin-layer chromatography imaging with a mobile phone.

    Science.gov (United States)

    Yu, Hojeong; Le, Huy M; Kaale, Eliangiringa; Long, Kenneth D; Layloff, Thomas; Lumetta, Steven S; Cunningham, Brian T

    2016-06-05

    Thin-layer chromatography (TLC) has a myriad of separation applications in chemistry, biology, and pharmacology due to its simplicity and low cost. While benchtop laboratory sample application and detection systems for TLC provide accurate quantitation of TLC spot positions and densities, there are many applications where inexpensive and portable instruments would greatly expand the applicability of the technology. In this work, we demonstrate identity verification and concentration determination of pharmaceutical compounds via TLC using a custom 3D-printed cradle that interfaces with an ordinary mobile phone. The cradle holds the mobile phone's internal, rear-facing camera in a fixed position relative to a UV lamp and a TLC plate that includes a phosphor in the stationary phase. Analysis of photographs thus reveals the locations and intensities of principal spots of UV--absorbing drugs. Automated image analysis software determines the center location and density of dark spots, which, using integrated calibration spots of known drug compounds and concentrations, can be used to determine if a drug has been diluted or substituted. Two independent image processing approaches have been developed that may be selected based upon the processing capabilities of the smartphone. Each approach is able to discern 5% drug concentration differences. Using single-component solutions of nevirapine, amodiaquine, and paracetamol that have been manually applied, the mobile phone-based detection instrument provides measurements that are equivalent to those obtained with a commercially available lab-based desktop TLC densitometer.

  14. HPTLC-aptastaining – Innovative protein detection system for high-performance thin-layer chromatography

    Science.gov (United States)

    Morschheuser, Lena; Wessels, Hauke; Pille, Christina; Fischer, Judith; Hünniger, Tim; Fischer, Markus; Paschke-Kratzin, Angelika; Rohn, Sascha

    2016-05-01

    Protein analysis using high-performance thin-layer chromatography (HPTLC) is not commonly used but can complement traditional electrophoretic and mass spectrometric approaches in a unique way. Due to various detection protocols and possibilities for hyphenation, HPTLC protein analysis is a promising alternative for e.g., investigating posttranslational modifications. This study exemplarily focused on the investigation of lysozyme, an enzyme which is occurring in eggs and technologically added to foods and beverages such as wine. The detection of lysozyme is mandatory, as it might trigger allergenic reactions in sensitive individuals. To underline the advantages of HPTLC in protein analysis, the development of innovative, highly specific staining protocols leads to improved sensitivity for protein detection on HPTLC plates in comparison to universal protein derivatization reagents. This study aimed at developing a detection methodology for HPTLC separated proteins using aptamers. Due to their affinity and specificity towards a wide range of targets, an aptamer based staining procedure on HPTLC (HPTLC-aptastaining) will enable manifold analytical possibilities. Besides the proof of its applicability for the very first time, (i) aptamer-based staining of proteins is applicable on different stationary phase materials and (ii) furthermore, it can be used as an approach for a semi-quantitative estimation of protein concentrations.

  15. Incompatibility studies by high performance thin-layer chromatography: In case of curcumin

    Directory of Open Access Journals (Sweden)

    Alankar Shrivastava

    2013-01-01

    Full Text Available Curcumin[1,7-bis (4-hydroxy-3-methoxy-phenyl hepta-1, 6-diene-3, 5-dione] is one of the component present in the turmeric. Curcumin has been in use for its medicinal benefits since centuries and its therapeutic potential is continuously explored through various researchers throughout the world. To investigate the interaction of curcumin with commonly used excipients such as microcrystalline cellulose, starch, colloidal silica, talc, ascorbic acid, lactose, ethyl cellulose (EC, sodium carboxymethylcellulose (Na-CMC, hydroxyl propyl methyl cellulose and magnesium stearate. High performance thin-layer chromatography (HPTLC is commonly used technique for the determination of phytoconstituents, but its application in incompatibility studies is still not investigated. Thus, we initiated our study with HPTLC followed by Fourier transform infrared and differential scanning calorimetry. Since interaction of curcumin with ascorbic acid, EC, Na-CMC and Mg-stearate confirmed by all three techniques these four excipients should be avoided during the formulation development of curcumin. The presented study also establishes HPTLC′s usefulness in such interaction studies.

  16. Nevirapine concentrations in saliva measured by thin layer chromatography and self-reported adherence in patients on antiretroviral therapy at kilimanjaro christian medical centre, Tanzania

    NARCIS (Netherlands)

    George, L.; Muro, E.P.; Ndaro, A.; Dolmans, W.M.; Burger, D.M.; Kisanga, E.R.

    2014-01-01

    BACKGROUND: Thin layer chromatography (TLC) can be used to perform therapeutic drug monitoring in resource-limited settings, where more expensive analytical methods, such as high-performance liquid chromatography or liquid chromatography-mass spectrometry, are not feasible. OBJECTIVES: The aim of th

  17. Separation and Detection of Ceramides by HPLC Followed by Evaporative Light-Scattering Detection and Thin Layer Chromatography

    Institute of Scientific and Technical Information of China (English)

    张琳; 周全; 傅学奇; 陈国强

    2002-01-01

    Ceramides are important signaling molecules involved in a variety of cellular processes, including cell growth, differentiation, and apoptosis. Currently, different methods are used for ceramide analysis, some of which are insensitive or cumbersome. This paper described methods utilizing thin layer chromatography (TLC) and high-performance liquid chromatography (HPLC) followed by evaporative light scattering detection (ELSD) to detect ceramide directly in cell extracts without derivatization, which was proved to be efficient and reproducible. Five kinds of ceramides were used as standards. Both TLC and normal-phase HPLC/ELSD results indicate that yeast contains several kinds of ceramides.

  18. The phytochemical screening and thin layer chromatography results of Jatropha gossypiifolia seeds

    Directory of Open Access Journals (Sweden)

    Anis Nurwidayati

    2013-05-01

    , the intermediary for schistosomiasis is widespread in this region. Eradication has been done by spraying chemical molluscicides. This study aimed to identify the class of chemical compounds in the methanol extract of red castor seed.Methods: The study was conducted in May 2009. Red castor seeds were collected from Palu, Central Sulawesi. Red castor seeds extraction was done by percolation method using methanol solvent. Phytochemical screening test was performed with a tube to detect the compound in red castor bean extract. Screening was followed by thin layer chromatography testing to ensure the screening results of the test tube.Results:Extracts that was produced from 500 grams of red castor dry seed powder with 2500 ml of methanol solvent was 250 ml thick reddish brown fluid. Phytochemical screening with a test tube showed positive results of alkaloid by the formation of deposits in Meyer test, Wagner test, and Dragendorff test. Screening the methanol extracts of red castor seed also showed positive results on saponins by foam test and LiebermanBurchard test. Positive results on Killiani Keller tests and Kedde test suggests that red castor bean extract contains cardenoline and bufadienol. Thin-layer chromatography analysis showed that the red castor bean extract is positive for terpenes with the formation of spots on the silica gel plate when terpenes was sprayed (cerium sulfate reagent. Conclusion: Chemical components contained in the methanol extract of red castor beans consisted of alkaloids, saponins, cardenolin, bufadienol, and terpenes. (Health Science Indones 2012;2:xx-xxKeywords: schistosomiasis, Jatropha gossypifolia, chemical compound

  19. Thin-layer chromatography analysis and scavenging activity of marigold (Calendula officinalis L extracts

    Directory of Open Access Journals (Sweden)

    Ćetković Gordana S.

    2003-01-01

    Full Text Available The methanol, petroleum ether, chloroform, ethyl acetate, n-butanol and water extracts were obtained by extraction of marigold flower (Calendula officinalis L. The content of total phenolic compounds, determined by UV spectrophotometric method using the Folin-Ciocalteu reagent, was 15.12 mg/g. The content of total flavonoids, determined by UV spectrophotometric method according to Markham, was 5.13 mg/g. Qualitative determination of phenolic compounds in the extracts was performed by one- and two-dimensional thin-layer chromatography (TLC procedures. The results of one- and two-dimensional TLC analyses showed that different flavonoids and phenolic acids were present in the investigated extracts. The greatest number of flavonoids (rutin, quercetin and some unidentified flavonoid glycosides and phenolic acids (chlorogenic, caffeic, coumaric and vanillic acid were deteminated in methanol extract. The influence of marigold extracts, in concentration range 0.6-1.2 mg/mL, on 2,2’-diphenyl-1-picrylhydrazyl (DPPH free radicals was investigated by electron spin resonance (ESR spectroscopy. All extracts showed scavenging activity (SA in the following order: ethyl acetate > n-butanol > methanol > water > chloroform > petroleum ether. The SA increased with increasing concentration of extracts. The ethyl acetate and n-butanol extracts exibited the most significant SA. These extracts in concentration of 1.2 mg/mL eliminated completely DPPH radicals. The lowest SA had chloroform and petroleum ether extracts (in concentration of 0.6 mg/mL SA=0%. The SA of marigold extracts is attributed to its hydrogen-donating ability and scavenging effect.

  20. High Performance Thin Layer Chromatography method for analysis of 3,4-methylenedioxymethamphetamine in seized tablets

    Directory of Open Access Journals (Sweden)

    Boris E. Duffau

    2015-12-01

    Full Text Available Context: Consumption of synthetic drugs had increased in recent years, used as a recreational drug by young people who presume that consumption of this drug is harmless for health; however clinical studies have shown that this stimulant and its metabolites are toxic. Due to these reasons, chemical analysis of this illicit drug is crucial from the points of view of occupational medicine, toxicology, and law enforcement with the aim of pursuit the traffic of illegal drug. Aims: Implement and fully validate a rapid and simple method for detection and quantitation of MDMA by High-Performance Thin Layer Chromatography in seized samples. Methods: With the implemented method was analyzed 12 positive samples seized by Chilean police, to found the concentration of MDMA in ecstasy tablets. Results: The method was fully validated, the linearity of the method was evaluated by the calibration curve between 51.0 – 510.0 µg/band (R2 0.9977; limit of detection was 12.1 µg per band, and limit of quantitation was 36.8 µg per band. The precision of the method (RSD was lower than 5.0%. Accuracy was evaluated by determination of the percentage of MDMA recovered by the assay (99.13%, and relative Uncertainty was 6.66%. With this method, it was analyzed real seized samples of MDMA, results showed that all samples contained MDMA and concentration was between 18.15 – 59.84 % w/w. Conclusions: The method is selective, sensitive, and specific, with possible application in forensic analysis. To the best of our knowledge, this is the first report about concentration of MDMA in ecstasy pills in Chile.

  1. Thin-Layer Chromatography/Desorption Electrospray Ionization Mass Spectrometry: Investigation of Goldenseal Alkaloids

    Energy Technology Data Exchange (ETDEWEB)

    Van Berkel, Gary J [ORNL; Tomkins, Bruce A [ORNL; Kertesz, Vilmos [ORNL

    2007-01-01

    Desorption electrospray ionization mass spectrometry was investigated as a means to qualitatively identify and to quantify analytes directly from developed normal-phase thin layer chromatography plates. The atmospheric sampling capillary of a commercial ion trap mass spectrometer was extended to permit sampling and ionization of analytes in bands separated on intact TLC plates (up to 10 cm x 10 cm). A surface positioning software package and the appropriate hardware enabled computer-controlled surface scanning along the length of development lanes or at fixed RF value across the plates versus the stationary desorption electrospray emitter. Goldenseal (Hydrastis canadensis) and related alkaloids and commercial dietary supplements were used as standards and samples. Alkaloid standards and samples were spotted and separated on aluminum- or glass-backed plates using established literature methods. The mass spectral signal levels as a function of desorption spray solvent were investigated with acetonitrile proving superior to methanol. The detection levels (ca. 5 ng each or 14 -28 pmol) in mass spectral full scan mode were determined statistically from the calibration curves (2.5 - 100 pmol) for the standards berberine, palmatine and hydrastinine spotted as a mixture and separated on the plates. Qualitative screening of the major alkaloids present in six different over-the-counter "goldenseal" dietary supplements was accomplished by obtaining full scan mass spectra during surface scans along the development lane in the direction of increasing RF value. In one sample, alkaloids were detected that strongly suggested the presence of at least one additional herb undeclared on the product label. These same data indicated the misidentification of one of the alkaloids in the TLC literature. Quantities of the alkaloids present in two of the samples determined using the mass spectral data were in reasonable agreement with the label values indicating the quantitative ability of

  2. Simple Identification of the Neutral Chlorinated Auxin in Pea by Thin Layer Chromatography

    DEFF Research Database (Denmark)

    Engvild, Kjeld Christensen

    1980-01-01

    One of the neutral chlorinated auxins of immature pea seeds was readily identified by thin layer procedures simple enough to serve in student's laboratory courses. 4-Chloroindole-3-acetic acid methyl ester was extracted from 50 g of commercial, frozen peas by either water or acetone, concentrated...

  3. Hydrophobic-hydrophilic monolithic dual-phase layer for two-dimensional thin-layer chromatography coupled with surface-enhanced Raman spectroscopy detection.

    Science.gov (United States)

    Zheng, Binxing; Liu, Yanhua; Li, Dan; Chai, Yifeng; Lu, Feng; Xu, Jiyang

    2015-08-01

    Hydrophobic-hydrophilic monolithic dual-phase plates have been prepared by a two-step polymerization method for two-dimensional thin-layer chromatography of low-molecular-weight compounds, namely, several dyes. The thin 200 μm poly(glycidyl methacrylate-co-ethylene dimethacrylate) layers attached to microscope glass plates were prepared using a UV-initiated polymerization method within a simple glass mold. After cutting and cleaning the specific area of the layer, the reassembled mold was filled with a polymerization mixture of butyl methacrylate and ethylene dimethacrylate and subsequently irradiated with UV light. During the second polymerization process, the former layer was protected from the UV light with a UV mask. After extracting the porogens and hydrolyzing the poly(glycidyl methacrylate-co-ethylene dimethacrylate) area, these two-dimensional layers were used to separate a mixture of dyes with great difference in their polarity using reversed-phase chromatography mode within the hydrophobic layer and then hydrophilic interaction chromatography mode along the hydrophilic area. In the latter dimension only the specific spot was developed further. Detection of the separated dyes could be achieved with surface-enhanced Raman spectroscopy.

  4. Thin-layer chromatographie separation of alkaline earth metals on diethylaminoethyl cellulose.

    Science.gov (United States)

    Ishida, K

    1969-12-01

    Thin-layer Chromatographic behaviour of magnesium, calcium, strontium and barium on diethylaminoethyl cellulose has been investigated in methanol-nitric acid mixtures. R(f) values are in the order magnesium > calcium > strontium > barium. The differences in R(f) values are large enough to allow good separations of the four metal ions from each other. The best separation is obtained by the ascending technique with methanol-8M nitric acid (20:1, v v ).

  5. A validated high performance thin layer chromatography method for determination of yohimbine hydrochloride in pharmaceutical preparations

    OpenAIRE

    Badr, Jihan M.

    2013-01-01

    Background: Yohimbine is an indole alkaloid used as a promising therapy for erectile dysfunction. A number of methods were reported for the analysis of yohimbine in the bark or in pharmaceutical preparations. Materials and Method: In the present work, a simple and sensitive high performance thin layer chromatographic method is developed for determination of yohimbine (occurring as yohimbine hydrochloride) in pharmaceutical preparations and validated according to International Conference of Ha...

  6. Analysis of the Nucleoside Content of Cordyceps sinensis Using the Stepwise Gradient Elution Technique of Thin-Layer Chromatography

    Institute of Scientific and Technical Information of China (English)

    MA,King-Wah(马敬桦); CHAU,Foo-Tim(周福添); WU,Jian-Yong(吴建勇)

    2004-01-01

    Nucleoside is the main class of active components in Cordyceps sinensis. Thin-layer chromatography (TLC) is one of the most commonly used methods in pharmacopoeias for analyzing chemical components of herbal medicine. Since the isocratic elution method cannot be applied successfully in TLC analysis for separating all the nucleoside components, the stepwise gradient elution has been developed in this work to separate eight nucleoside standards with success. In this way, quantitative analyses of the samples of Cordyceps sinensis were achieved via the proposed TLC procedure coupled with the scanning densitometric techniques of CAMAG and TLCQA methods for qualitative and quantitative analysis.

  7. Rapid method for hydrocarbon-type analysis of heavy oils and synthetic fuels by pyrolysis thin layer chromatography

    Energy Technology Data Exchange (ETDEWEB)

    Poirier, M.A.; George, A.E.

    1982-09-01

    This work describes a rapid method for hydrocargon-type analysis applying thin layer chromatography (TLC) to the pentane-soluble fraction *malthenes) of the petroleum and synthetic fuels boiling above 200/sup 0/C. The principal component types encountered in this paper are saturates (SA), aromatics (AR), (mono and di together) polynuclear aromatics (PNA) and polar material (PO). The method uses a Iatroscan TLC pyrolyzer which combines the resolution capabilities of TLC with the possibility of quantification by using a flame-ionization detector (FID). Comparison of the results with those obtained by the API-60 procedure is presented.

  8. Application of high-performance, thin-layer chromatography to quality control of antimetabolite analogue infusion bags.

    Science.gov (United States)

    Perello, L; Demirdjian, S; Dory, A; Bourget, P

    2001-01-01

    A global postproduction quality program was developed to secure chemotherapy infusion at the Gustave Roussy Institute. Despite rigorous procedures and computerized prescriptions, an analytical check was necessary to improve the quality of ready-to-use solutions of cytotoxic drugs in our Centralized Antineoplastics Reconstitution Unit. High-performance, thin-layer chromatography was selected as the analytical tool to assay 12 anticancer drugs. One of the analytical methods can separate 4 antimetabolite substances, i.e., fludarabine (FDB), cytarabine (CTB), gemcitabine (GTB), and fluorouracil (5 FU). For all infusion bags manufactured, up to 26 samples could be assayed per series using a double standard calibration (GTB and 5 FU).

  9. Peak broadening in paper chromatography and related techniques VI. The efficiency of various kinds of chromatography paper and thin-layer cellulose powder for the separation of amino acids

    NARCIS (Netherlands)

    Ligny, C.L. de; Kok, E.C.M.

    1968-01-01

    The efficiency of several chromatography papers and thin-layer cellulose powders for the separation of amino acids is investigated, using the minimum elution time for a given resolution as the criterion.

  10. Separation of Berberine Hydrochloride and Tetrahydropalmatine and Their Quantitative Analysis with Thin Layer Chromatography Involved with Ionic Liquids

    Directory of Open Access Journals (Sweden)

    Jing Lu

    2015-01-01

    Full Text Available [BMIM]OH was used in mobile and stationary phase of thin layer chromatography (TLC to analyze berberine hydrochloride and tetrahydropalmatine for the first time. Supported imidazole ionic liquid with hydroxide ion on silica gel (SiO2·Im+·OH− was synthesized through simple procedure and characterized by Fourier transform infrared spectroscopy (FT-IR, elemental analysis, and scanning electron microscope (SEM. Moreover, on the plates prepared by SiO2·Im+·OH−, the contents of the above alkaloids in the Chinese patent medicine (CPM of “Stomacheasy” capsule were successfully determined by TLC scanner. The key conditions and chromatographic behaviors were also investigated in detail. According to similar ways, ionic liquids (ILs also can be used in other planar chromatographies in two modes. This study is expected to be helpful in expanding the application of IL and its bonded silica gel in TLC separation field.

  11. Preparation of porous styrenics-based monolithic layers for thin layer chromatography coupled with matrix-assisted laser-desorption/ionization time-of-flight mass spectrometric detection.

    Science.gov (United States)

    Lv, Yongqin; Lin, Zhixing; Tan, Tianwei; Svec, Frantisek

    2013-11-01

    Monolithic 50 μm thin poly(4-methylstyrene-co-chloromethylstyrene-co-divinylbenzene) layers attached to 6.0 cm × 3.3 cm glass plates have been prepared, using a thermally initiated polymerization process. These layers had a well-defined porous structure with a globular morphology demonstrated with SEM images and exhibited superhydrophobic properties characterized with a water contact angle of 157°. They were then used for thin-layer chromatography of peptides and proteins fluorescently labeled with fluorescamine. The spots of individual separated compounds were visualized using UV light, and their identities were confirmed with a matrix-assisted laser desorption/ionization time of flight mass spectrometry. The presence of chloromethylstyrene units in the polymer enabled hypercrosslinking via a Friedel-Crafts alkylation reaction, and led to monoliths with much larger surface areas, which were suitable for separations of small dye molecules.

  12. Monitoring of monooctanoyl phosphatidylcholine synthesis by enzymatic acidolysis between soybean phosphatidylcholine and caprylic acid by thin-layer chromatography with a flame ionization detector

    DEFF Research Database (Denmark)

    Vikbjerg, Anders Falk; Mu, Huiling; Xu, Xuebing

    2005-01-01

    Thin-layer chromatography with flame ionization detector (TLC-FID) method was used for monitoring the production of structured phospholipids (ML-type: L-long chain fatty acids; M-medium chain fatty acids) by enzyme-catalyzed acidolysis between soybean phosphatidylcholine (PC) and caprylic acid....... It was found that the structured PC fractionated into 2-3 distinct bands on both plate thin layer chromatography (TLC) and Chromarod TLC. These 3 bands represented PC of LL-type, ML-type and MM-type, respectively. The TLC-FID method was applied in the present study to examine the influence of enzyme dosage...

  13. Qualitative and quantitative two-dimensional thin-layer chromatography/high performance liquid chromatography/diode-array/electrospray-ionization-time-of-flight mass spectrometry of cholinesterase inhibitors.

    Science.gov (United States)

    Mroczek, Tomasz

    2016-09-10

    Recently launched thin-layer chromatography-mass spectrometry (TLC-MS) interface enabling extraction of compounds directly from TLC plates into MS ion source was unusually extended into two-dimensional thin-layer chromatography/high performance liquid chromatography (2D, TLC/HPLC) system by its a direct connection to a rapid resolution 50×2.1mm, I.D. C18 column compartment followed by detection by diode array (DAD) and electrospray ionisation time-of-flight mass spectrometry (ESI-TOF-MS). In this way, even not separated bands of complicated mixtures of natural compounds could be analysed structurally, only within 1-2min after development of TLC plates. In comparison to typically applied TLC-MS interface, no ion suppression for acidic mobile phases was observed. Also, substantial increase in ESI-TOF-MS sensitivities and quality of spectra, were noticed. It has been utilised in combination with TLC- based bioautographic approaches of acetylcholinesterase (AChE) inhibitors, However, it can be also applied in any other procedures related to bioactivity (e.g. 2,2-Diphenyl-1-picryl-hydrazyl-DPPH screen test for radicals). This system has been also used for determination of half maximal inhibitory concentration (IC50 values) of the active inhibitor-galanthamine, as an example. Moreover, AChE inhibitory potencies of some of purified plant extracts, never studied before, have been quantitatively measured. This is first report of usage such the 2D TLC/HPLC/MS system both for qualitative and quantitative evaluation of cholinesterase inhibitors in biological matrices.

  14. [Using thin-layer chromatography of fecal bile acid to study the Persian leopard (Panthera pardus ciscaucasica) population].

    Science.gov (United States)

    Khorozian, I G; Cazon, A; Malkhasian, A G; Abramov, A V

    2007-01-01

    Thin-layer chromatography (TLC) of fecal bile acids has been used to confirm visual identification of 30 scat samples found in Armenia from April 2004 to November 2005 and attributed to the Persian leopard (Panthera pardus ciscaucasica). The results of TLC do not differ significantly from those of visual identification, confirming the reliability of the latter method. All samples identified incorrectly (lynx and wolf scats) are from the Meghri Ridge, indicating that the ecological niches of the three predators apparently overlap in this area. Taking into account the frequency and distribution of scats, two priority areas for leopard conservation have been identified: the Central and Khachadzor districts of the Khosrov Nature Reserve and the Nuvadi-Shvanidzor area in eastern Meghri ridge.

  15. Rolling--a new application technique for luminescent bacteria on high-performance thin-layer chromatography plates.

    Science.gov (United States)

    Baumgartner, Vera; Hohl, Christopher; Schwack, Wolfgang

    2011-05-13

    High-performance thin-layer chromatography (HPTLC) coupled with bioluminescence detection using Vibrio fischeri bacteria can be used for screening for unknown substances. This is accomplished by dipping the HPTLC plate in an aqueous bacteria solution. Especially polar substances, however, can start to dissolve during this process, which leads to blurring and tailing of the zones on the plate. To overcome this disadvantage, we applied the bacteria solution by rolling. This method has been described for chemical derivatizations, but is very rarely used. The rolling device was made of commercially available household articles. Using octhilinone and methylparaben as test compounds, rolling was compared with dipping. Despite of performing the rolling process manually, the results were reproducible. Depending on the substance and its amount on the HPTLC plate, peaks were narrower, up to a factor of 4 higher and with a higher signal-to-noise ratio than after dipping.

  16. Validation Thin Layer Chromatography for the Determination of Acetaminophen in Tablets and Comparison with a Pharmacopeial Method

    Directory of Open Access Journals (Sweden)

    Alina Pyka

    2013-01-01

    Full Text Available Adsorption thin layer chromatography (NP-TLC with densitometry has been established for the identification and the quantification of acetaminophen in three leading commercial products of pharmaceutical tablets coded as brand: P1 (Product no. 1, P2 (Product no. 2, and P3 (Product no. 3. Applied chromatographic conditions have separated acetaminophen from its related substances, namely, 4-aminophenol and and 4′-chloroacetanilide. UV densitometry was performed in absorbance mode at 248 nm. The presented method was validated by specificity, range, linearity, accuracy, precision, detection limit, quantitative limit, and robustness. The TLC-densitometric method was also compared with a pharmacopeial UV-spectrophotometric method for the assay of acetaminophen, and the results confirmed statistically that the NP-TLC-densitometric method can be used as a substitute method. It could be said that the validated NP-TLC-densitometric method is suitable for the routine analysis of acetaminophen in quantity control laboratories.

  17. Validated high-performance thin-layer chromatography method for steviol glycosides in Stevia rebaudiana.

    Science.gov (United States)

    Jaitak, Vikas; Gupta, A P; Kaul, V K; Ahuja, P S

    2008-08-05

    A high-performance thin-layer chromatographic (HPTLC) method was developed and validated as per ICH (International Conferences on Harmonization) guidelines for simultaneous quantification of three steviol glycosides, i.e. steviolbioside, stevioside and rebaudioside-A in Stevia rebaudiana leaves. For achieving good separation, mobile phase of ethyl acetate-ethanol-water (80:20:12, v/v/v) on pre-coated silica gel 60 F254 HPTLC plates were used. The densitometric quantification of steviol glycosides was carried out at lambda=510 nm in reflection-absorption mode after spraying with acetic anhydride:sulphuric acid:ethanol reagent. The calibration curves were linear in the range of 160-960 ng/spot for steviolbioside, 1-6 microg/spot for stevioside and 0.5-3 microg/spot for rebaudioside-A with good correlation coefficients (0.998-0.999). The method was found to be reproducible for quantitative analysis of steviol glycosides in S. rebaudiana leaves collected from ten different locations and will serve as a quality control indicator to monitor the commercial production of stevioside and its allied molecules during different stages of its processing.

  18. Application of thin-layer chromatography of fat and oil, fatty acid and mineral oil for science education. Yushi, shibosan, koyu no hakuso chromatography to sono kyozaiteki katsuyo

    Energy Technology Data Exchange (ETDEWEB)

    Kawabuchi, K. (Ehime Univ., Ehime (Japan)); Takechi, Y.; Morimoto, M. (Ehime (Japan))

    1990-08-20

    In this article, with regard to application of thin-layer chromatography of fat and oil, fatty acid and mineral oil for science education, a study was made mainly on quality finding of n-hexane extracts provided in the law of prevention of water pollution, and separation of hydrolysis products of fat and oil. As a result, the existance of fat and oil, fatty acid and mineral oil in the enviromental water and the hydrolysis process of fat and oil could experimentally be confirmed. This is considered to be useful for studying teaching material on fat and oil. This report deals with the reagents and device, and specifies standard solution, thin-layer plate, spread solvent, spread tank and thermostat, and states, for its operation, the method using enzyme for hydrolysis of fat and oil and the method using potassium hydroxide. It also contemplates on R {sub f} values of fat and oil, fatty acid and mineral oil, etc., as well as spread of fat and oil, oils contained in n-hexane extracts and hydrolysis products of fat and oil. 6 refs., 4 figs., 1 tab.

  19. Validation of an analytical method for the determination of spiramycin, virginiamycin and tylosin in feeding-stuffs bij thin-layer chromatography and bio-autography

    NARCIS (Netherlands)

    Vincent, U.; Gizzi, G.; Holst, von C.; Jong, de J.; Michard, J.

    2007-01-01

    An inter-laboratory validation was carried out to determine the performance characteristics of an analytical method based on thin-layer chromatography (TLC) coupled to microbiological detection (bio-autography) for screening feed samples for the presence of spiramycin, tylosin and virginiamycin. Twe

  20. Determination of ivermectin stability by high-performance thin-layer chromatography

    Directory of Open Access Journals (Sweden)

    Mohd. Ali

    2011-06-01

    Full Text Available A rapid, sensi tive and stabi l i ty-signi fying high-performance thin-layer chromatographic (HPTLC method was developed and validated for the quantitative estimation of ivermectin (IVM as a bulk drug and in pharmaceutical formulations. The separation was achieved on Lichrospher TLC aluminum plates pre-coated with silica gel 60F-254 (20cm×10cm×200 :m using n-hexane: acetone: ethylacetate (6.5: 3.5: 0.1 v/v/v as mobi le phase. The densitometric analysis was carried out at 247 nm wavelength. Compact spots of IVM were found at Rf = 26±0.02. For proposed procedure, linearity (r2 = 0.9989, limit of quantification (24.9 ng spot−1, limit of detection (8.22 ng spot−1 recovery (98.25–100.16%, and inter as well intra-day precision (≤2.21 was found to be satisfactory. We have synthesized polymeric nanoparticles encapsulated formulat ion of ivermectin (IVM-NPs ; ut i l izing micel lar aggregates of cross-l inked random copolymer Nisopropylacrylamide (NIPAAM with N-vinyl-2-pyrrolidone (VP and polyethyleneglycol monoacrylate (PEG-A for lymphat ic targeting and i t was also quanti f ied by the developed method. IVM and formulations were subjected to acid and alkali hydrolysis, oxidation and photo-degradation. The drug undergoes degradation under acidic, basic, light and oxidation conditions. This indicates that the drug is susceptible to acid- base hydrolysis, oxidation and photo-oxidation and the developed method is selective for quantifying IVM even in the presence of degradatnts. The method was applicable for routine analysis and stability testing of IVM in pharmaceutical drug delivery systems. As the method could effectively separate the said drug from its degradation products, it can be employed as a stability indicating one.

  1. Determination of 2-Aminoacetophenone in wine by high-performance thin-layer chromatography-fluorescence detection.

    Science.gov (United States)

    Horlacher, Nora; Schwack, Wolfgang

    2016-02-01

    2-Aminoacetophenone (AAP) is closely correlated with the appearance of the sensory phenomenon of UTA ("untypical aging off-flavor") in wine. AAP analyses are generally performed by gas chromatography and mass selective detection (GC/MS), when AAP is extracted from wines by liquid-liquid, solid-liquid or solid phase microextraction. Here we present a rapid, selective and sensitive method for the determination of AAP in wine by high-performance thin-layer chromatography with fluorescence detection (HPTLC-FLD). As internal standard, 2-amino-4-methoxyacetophenone was used. Liquid-liquid extraction with t-butyl methyl ether was followed by a basic cleanup of the extracts, which were applied onto HPTLC amino plates developed with methylene chloride/toluene (7+3, v/v) as mobile phase. Dipping the dried plate into hexane-paraffin solution enhanced fluorescence that was scanned at 366/>400nm. Limits of detection and quantitation were determined to be 0.1 and 0.3μgL(-1) wine, respectively, while only AAP concentrations >0.5μgL(-1) result in UTA. Recoveries were near 100% for model, white, rosé and red wines. Thus, the HPTLC-FLD method enables the analysis of AAP in wines clearly below the odor thresholds and represents a rapid and convenient screening alternative to existing GC/MS methods.

  2. Assessment of aflatoxin B1 in livestock feed and feed ingredients by high-performance thin layer chromatography

    Directory of Open Access Journals (Sweden)

    Korrapati Kotinagu

    2015-12-01

    Full Text Available Aim: Detection of aflatoxin B1 in Livestock compound Feed and feed ingredients by high-performance thin layer chromatography (HPTLC. Materials and Methods: Chromatography was performed on HPTLC silica gel 60 F 254, aluminum sheets by CAMAG automatic TLC sampler 4, with mobile phase condition chloroform:acetone:water (28:4:0.06. Extraction of aflatoxin B1 from samples was done as per AOAC method and screening and quantification done by HPTLC Scanner 4 under wavelength 366 nm. Results: A total of 97 livestock feed (48 and feed ingredients (49 samples received from different livestock farms and farmers were analyzed for aflatoxin B1of which 29 samples were contaminated, constituting 30%. Out of 48 livestock compound feed samples, aflatoxin B1 could be detected in 16 samples representing 33%, whereas in livestock feed ingredients out of 49 samples, 13 found positive for aflatoxin B1 representing 24.5%. Conclusion: HPTLC assures good recovery, precision, and linearity in the quantitative determination of aflatoxin B1 extracted from Livestock compound feed and feed ingredients. As more number of feed and feed ingredients are contaminated with aflatoxin B1 which causes deleterious effects in both animal and human beings, so there is a need for identifying the source of contamination, executing control measures, enabling better risk assessment techniques, and providing economic benefits.

  3. [Determination of the four generic fractions of aged bitumen by thin-layer chromatography with flame ionization detection].

    Science.gov (United States)

    Feng, Zhengang; Zhang, Jianbin; Li, Xinjun; Yu, Jianying

    2015-02-01

    The aging process of bitumen has been paid more and more attention by the researchers. The four generic fractions (saturates, aromatics, resins and asphaltenes) of bitumen change significantly during the aging process. The analysis of the changes of the four generic fractions of bitumen is very helpful to reveal the bitumen aging mechanisms and guide its engineering applications. In this study, the bitumen was aged by thin film oven test (TFOT) , pressurized aging vessel (PAV) test and ultraviolet (UV) aging test, respectively. Then the four generic fractions of bitumen before and after aging were analyzed by thin-layer chromatography with flame ionization detection (TLC-FID) , which was further compared with the solubility procedures and chromatographic technique ( named as Corbett method). The compositions of the expanded solvents were also investigated. Finally, the correlation between the TLC-FID and Corbett method was further studied, which revealed a proper TLC-FID meth- od for detection of aged bitumen. The bitumen solution dissolved by dichloromethane was successively expanded by n-heptane, toluene/n-heptane (80 :20, v/v) and toluene/ethanol (55: 45, v/v) , followed by TLC-FID. This method is of great significance for the analysis of the four generic fractions of bitumen and for the exploration of bitumen aging mechanisms.

  4. Investigation of Symphytum cordatum alkaloids by liquid-liquid partitioning, thin-layer chromatography and liquid chromatography-ion-trap mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Mroczek, Tomasz [Department of Pharmacognosy with Medicinal Plants Laboratory, Medical University, 1 Chodzki St., 20-093 Lublin (Poland)]. E-mail: tmroczek@pharmacognosy.org; Ndjoko-Ioset, Karine [Laboratoire de Pharmacognosie et Phytochimie, Ecole de Pharmacie Geneve-Lausanne, Universite de Geneve, Quai Ernest-Ansermet 30, CH-1211 Geneva 4 (Switzerland); Glowniak, Kazimierz [Department of Pharmacognosy with Medicinal Plants Laboratory, Medical University, 1 Chodzki St., 20-093 Lublin (Poland); Mietkiewicz-Capala, Agnieszka [Department of Pharmacognosy with Medicinal Plants Laboratory, Medical University, 1 Chodzki St., 20-093 Lublin (Poland); Hostettmann, Kurt [Laboratoire de Pharmacognosie et Phytochimie, Ecole de Pharmacie Geneve-Lausanne, Universite de Geneve, Quai Ernest-Ansermet 30, CH-1211 Geneva 4 (Switzerland)

    2006-05-04

    From the alkalised crude extract of Symphytum cordatum (L.) W.K. roots, pyrrolizidine alkaloids (PAs) were extracted as free tertiary bases and polar N-oxides in a merely one-step liquid-liquid partitioning (LLP) in separation funnel and subsequently pre-fractionated by preparative multiple-development (MD) thin-layer chromatography (TLC) on silica gel plates. In this way three alkaloid fractions of different polarities and retention on silica gel plates were obtained as: the most polar N-oxides of the highest retention, the tertiary bases of medium retention, and diesterified N-oxides of the lowest retention. The former fraction was reduced into free bases by sodium hydrosulfite and purified by LLP on Extrelut-NT3 cartridge. It was further analysed together with the two other fractions by high-performance liquid chromatography (HPLC)-ion-trap mass spectrometry with atmospheric pressure chemical ionization (APCI) interface on XTerra C{sub 18} column using a gradient elution. Based on MS {sup n} spectra, 18 various alkaloids have been tentatively determined for the first time in this plant as the following types of structure: echimidine-N-oxide (three diasteroisomers), 7-sarracinyl-9-viridiflorylretronecine (two diasteroisomers), echimidine (two diasteroisomers), lycopsamine (two diasteroisomers), dihydroechinatine-N-oxide, dihydroheliospathuline-N-oxide, lycopsamine-N-oxide (three diasteroisomers), 7-acetyllycopsamine-N-oxide, symphytine-N-oxide (two diasteroisomers) and 2'',3''-epoxyechiumine-N-oxide.

  5. Separation of the Carotenoid Bixin from Annatto Seeds Using Thin-Layer and Column Chromatography

    Science.gov (United States)

    McCullagh, James V.; Ramos, Nicholas

    2008-01-01

    In this experiment the carotenoid bixin is isolated from annatto ("Bixa orellana") seeds using column chromatography. The experiment has several key advantages over previous pigment separation experiments. First, unlike other experiments significant quantities of the carotenoid (typically 20 to 25 mg) can be isolated from small quantities of plant…

  6. Method development for Lawsone estimation in Trichup herbal hair powder by high-performance thin layer chromatography.

    Science.gov (United States)

    Patel, Maunang M; Solanki, Bhavna R; Gurav, Nilesh C; Patel, Prateek H; Verma, Shweta S

    2013-07-01

    A simple, specific, accurate, precise and robust high-performance thin-layer chromatographic method has been developed and validated for estimation of Lawsone in Trichup herbal hair powder (coded as a THHP), polyherbal formulation. The chromatographic development was carried out on aluminum plates pre-coated with silica gel 60F254 and good resolution was achieved with Toluene: Ethyl acetate: Glacial acetic acid (8:1:1 v/v/v) as mobile phase. Lawsone detection was carried out densitometrically at 277 nm and obtained retardation factor value was 0.46 ± 0.02. The method was validated with respect to specificity, linearity, accuracy, precision and robustness. The calibration curve was achieved to be linear over a range of 5-60 μg/ml and regression coefficient was obtained 0.998. Accuracy of chromatographic method was evaluated by standard addition method; recovery was obtained 99.25 ± 0.61%. The peak purity of Lawsone was achieved 0.999 r. Relative standard deviation for intraday and inter-day precision was 0.37-0.56% and 0.42-0.55%, respectively. The limit of detection and limit of quantification of the Lawsone were found to be 1.08 μg/m land 3.28 μg/ml, respectively. This result shows that the method was well validated. In the present study, the Lawsone content was found 0.322 ± 0.014% in THHP. This study reveals that the proposed high performance thin layer chromatography method is accurate, fast and cost- effective for routine estimation of Lawsone in polyherbal formulation.

  7. Method development for Lawsone estimation in Trichup herbal hair powder by high-performance thin layer chromatography

    Directory of Open Access Journals (Sweden)

    Maunang M Patel

    2013-01-01

    Full Text Available A simple, specific, accurate, precise and robust high-performance thin-layer chromatographic method has been developed and validated for estimation of Lawsone in Trichup herbal hair powder (coded as a THHP, polyherbal formulation. The chromatographic development was carried out on aluminum plates pre-coated with silica gel 60F 254 and good resolution was achieved with Toluene: Ethyl acetate: Glacial acetic acid (8:1:1 v/v/v as mobile phase. Lawsone detection was carried out densitometrically at 277 nm and obtained retardation factor value was 0.46 ± 0.02. The method was validated with respect to specificity, linearity, accuracy, precision and robustness. The calibration curve was achieved to be linear over a range of 5-60 μg/ml and regression coefficient was obtained 0.998. Accuracy of chromatographic method was evaluated by standard addition method; recovery was obtained 99.25 ± 0.61% . The peak purity of Lawsone was achieved 0.999 r. Relative standard deviation for intraday and inter-day precision was 0.37-0.56% and 0.42-0.55%, respectively. The limit of detection and limit of quantification of the Lawsone were found to be 1.08 μg/m land 3.28 μg/ml, respectively. This result shows that the method was well validated. In the present study, the Lawsone content was found 0.322 ± 0.014% in THHP. This study reveals that the proposed high performance thin layer chromatography method is accurate, fast and cost- effective for routine estimation of Lawsone in polyherbal formulation.

  8. Chromatography.

    Science.gov (United States)

    Brantley, L. Reed, Sr.; Demanche, Edna L.; Klemm, E. Barbara; Kyselka, Will; Phillips, Edwin A.; Pottenger, Francis M.; Yamamoto, Karen N.; Young, Donald B.

    This booklet presents some activities on chromatography. Directions for preparing leaf pigment extracts using alcohol are given, and paper chromatography and thin-layer chromatography are described as modifications of the basic principles of chromatography. (KHR)

  9. Lipophilic properties of anti-Alzheimer's agents determined by micellar electrokinetic chromatography and reversed-phase thin-layer chromatography.

    Science.gov (United States)

    Godyń, Justyna; Hebda, Michalina; Więckowska, Anna; Więckowski, Krzysztof; Malawska, Barbara; Bajda, Marek

    2017-02-07

    Lipophilicity as one of the most important physicochemical properties of the biologically active compounds is closely related to their pharmacokinetic parameters and therefore, it is taken into account at the design stage of new drugs. Among the novel, fast and reliable methods for determination of the lipophilicity of compounds micellar electrokinetic chromatography (MEKC) is considered to be an appropriate one for bioactive molecules, as it closely mimics the physiological conditions. In this paper MEKC was used for the estimation of log P values for 49 derivatives of phthalimide, tetrahydroisochinoline and indole, designed and synthesized as potential anti-Alzheimer's agents with cholinesterase inhibitory activity. RP-TLC method was applied for determination of another lipophilicity descriptor - RM0 . The results of both experimental methods were compared with each other giving satisfactory correlation (R = 0.784), and with computational methods (Marvin, ChemOffice Software) resulting in weaker correlation (R = 0.466 - 0.687). The lipophilicity-activity relationship was finally established, showing significant influence of lipophilicity on cholinesterase inhibition in some subgroups of phthalimide derivatives. This article is protected by copyright. All rights reserved.

  10. Thin-layer chromatography-densitometric analysis of alpha-mangostin content in Garcinia mangostana fruit rind extracts.

    Science.gov (United States)

    Pothitirat, Werayut; Gritsanapan, Wandee

    2008-01-01

    The fruit rinds of mangosteen (Garcinia mangostana Linn.) have long been used as traditional medicines for treatment of skin infections, wounds, and diarrhea. A simple thin-layer chromatography (TLC)-densitometric method has been developed for the simultaneous quantification of alpha-mangostin in the extracts from unripe and ripe fruit rinds of G. mangostana. It was found in the ranges of 10.48 +/- 0.83 and 16.65 +/- 0.38% (w/w) in the dried unripe and ripe fruit rinds, respectively. The method was validated for linearity, precision, accuracy, limit of detection (LOD), and limit of quantitation (LOQ). The linearity was found over the range of 100-500 ng/spot with regression coefficient 0.999. Intraday and interday precision studies showed the relative standard deviation was <2%. Accuracy of the method was determined by a recovery study conducted at 3 different levels, and the average recovery was 99.49%. The LOD and LOQ were 40 and 100 ng, respectively. The proposed TLC-densitometric method was found to be simple, precise, specific, sensitive, and accurate. This method can be used for routine quality control of raw material of G. mangostana fruit rind, extract, and its products. It also can be applied in quantifying this marker compound in other drugs.

  11. Multivariate image analysis-thin layer chromatography (MIA-TLC) for simultaneous determination of co-eluting components.

    Science.gov (United States)

    Hemmateenejad, Bahram; Mobaraki, Nabiollah; Shakerizadeh-Shirazi, Fatemeh; Miri, Ramin

    2010-07-01

    This paper addresses the solution of peak overlapping, as a fundamental problem in TLC, by multivariate analysis of the images recorded by a digital camera. We report the results of our study on the application of multivariate image analysis (MIA) for simultaneous determination of several species on thin layer chromatography (TLC) sheet for the first time. An imaging system, composed of a dark cabinet, a digital camera and a multivariate image analysis program, was prepared for recording the images of TLC plates after development of a multi-component solution. The written program was able to produce 2- and 3-dimensional chromatograms of the solutions, which were subsequently used as inputs of partial least squares, as an efficient multivariate calibration method. The ability of the proposed MIA-TLC method for simultaneous determination of the co-eluting components was validated by analysis of ternary synthetic mixtures of indicators of highly overlapped chromatograms (i.e., methyl yellow, bromocresol green and creseol red) and a real mixture of nifedipine and its photo-degradation product. By application of different strategies like principal component analysis and variable selection, models were obtained that could estimate the concentration of indicators in the external prediction set with relative errors of lower than 10% and in most cases lower than 5%.

  12. Detection of adulterated copaiba (Copaifera multijuga Hayne oil-resins by refractive index and thin layer chromatography

    Directory of Open Access Journals (Sweden)

    Karol de S. Barbosa

    2009-03-01

    Full Text Available The refractive indices (RI of the eight samples of copaiba oils, collected for this study at RDS Tupé ranged from 1.50284 to 1.50786. The thin layer chromatography (TLC plates of these oils revealed with anisaldehyde-sulphuric acid reagent showed dark lilac stains with several small stains at low Rf and a large rounded stain at high Rf. On the other hand, the twelve copaiba oils purchased at local markets presented RI between 1.48176 and 1.50886, and the TLC plates, showed as general profile blue stains, with smaller superimposed stains at low Rf, bigger superimposed stains like elongated stain at high Rf and a colorless rounded stain at middle Rf. Among 12 purchased oils at local markets, a three oil-resins presented similar RI and TLC profile to those observed for collected copaiba oils; b six oils showed same RI and TLC profiles to those observed for soybean oil; c three samples presented RI near to those showed by copaiba oil-resin, however the TLC profile was near to profile observed for a prepared mixture soybean oil: copaiba oil, two samples with 3:1 proportion and one sample with 1:3 proportion. Therefore, the RI determination and the TLC profiles could be considered rapid and efficient procedures for detection of vegetal oil in the copaiba oil-resins.

  13. Thin-layer chromatography and mass spectrometry coupled using proximal probe thermal desorption with electrospray or atmospheric pressure chemical ionization.

    Science.gov (United States)

    Ovchinnikova, Olga S; Van Berkel, Gary J

    2010-06-30

    An atmospheric pressure proximal probe thermal desorption sampling method coupled with secondary ionization by electrospray or atmospheric pressure chemical ionization was demonstrated for the mass spectrometric analysis of a diverse set of compounds (dyestuffs, pharmaceuticals, explosives and pesticides) separated on various high-performance thin-layer chromatography plates. Line scans along or through development lanes on the plates were carried out by moving the plate relative to a stationary heated probe positioned close to or just touching the stationary phase surface. Vapors of the compounds thermally desorbed from the surface were drawn into the ionization region of a combined electrospray ionization/atmospheric pressure chemical ionization source where they merged with reagent ions and/or charged droplets from a corona discharge or an electrospray emitter and were ionized. The ionized components were then drawn through the atmospheric pressure sampling orifice into the vacuum region of a triple quadrupole mass spectrometer and detected using full scan, single ion monitoring, or selected reaction monitoring mode. Studies of variable parameters and performance metrics including the proximal probe temperature, gas flow rate into the ionization region, surface scan speed, read-out resolution, detection limits, and surface type are discussed.

  14. Flowing atmospheric pressure afterglow combined with laser ablation for direct analysis of compounds separated by thin-layer chromatography.

    Science.gov (United States)

    Cegłowski, Michał; Smoluch, Marek; Reszke, Edward; Silberring, Jerzy; Schroeder, Grzegorz

    2016-01-01

    A thin-layer chromatography-mass spectrometry (TLC-MS) setup for characterization of low molecular weight compounds separated on standard TLC plates has been constructed. This new approach successfully combines TLC separation, laser ablation, and ionization using flowing atmospheric pressure afterglow (FAPA) source. For the laser ablation, a low-priced 445-nm continuous-wave diode laser pointer, with a power of 1 W, was used. The combination of the simple, low-budget laser pointer and the FAPA ion source has made this experimental arrangement broadly available, also for small laboratories. The approach was successfully applied for the characterization of low molecular weight compounds separated on TLC plates, such as a mixture of pyrazole derivatives, alkaloids (nicotine and sparteine), and an extract from a drug tablet consisting of paracetamol, propyphenazone, and caffeine. The laser pointer used was capable of ablating organic compounds without the need of application of any additional substances (matrices, staining, etc.) on the TLC spots. The detection limit of the proposed method was estimated to be 35 ng/cm(2) of a pyrazole derivative.

  15. Simultaneous determination of withanolide A and bacoside A in spansules by high-performance thin-layer chromatography

    Directory of Open Access Journals (Sweden)

    P B Shinde

    2011-01-01

    Full Text Available The objective of this work was to develop and validate a simple, rapid, precise, and accurate high performance thin layer chromatography method for simultaneous determination of withanolide A and bacoside A in combined dosage form. The stationary phase used was silica gel G60F 254 . The mobile phase used was mixture of ethyl acetate: methanol: toluene: water (4:1:1:0.5 v/v/v/v. The detection of spots was carried out at 320 nm using absorbance reflectance mode. The method was validated in terms of linearity, accuracy, precision and specificity. The calibration curve was found to be linear between 200 to 800 ng/spot for withanolide A and 50 to 350 ng/spot for bacoside A. The limit of detection and limit of quantification for the withanolide A were found to be 3.05 and 10.06 ng/spot, respectively and for bacoside A 8.3 and 27.39 ng/spot, respectively. The proposed method can be successfully used to determine the drug content of marketed formulation.

  16. Simultaneous determination of withanolide a and bacoside a in spansules by high-performance thin-layer chromatography.

    Science.gov (United States)

    Shinde, P B; Aragade, P D; Agrawal, M R; Deokate, U A; Khadabadi, S S

    2011-03-01

    The objective of this work was to develop and validate a simple, rapid, precise, and accurate high performance thin layer chromatography method for simultaneous determination of withanolide A and bacoside A in combined dosage form. The stationary phase used was silica gel G60F(254). The mobile phase used was mixture of ethyl acetate: methanol: toluene: water (4:1:1:0.5 v/v/v/v). The detection of spots was carried out at 320 nm using absorbance reflectance mode. The method was validated in terms of linearity, accuracy, precision and specificity. The calibration curve was found to be linear between 200 to 800 ng/spot for withanolide A and 50 to 350 ng/spot for bacoside A. The limit of detection and limit of quantification for the withanolide A were found to be 3.05 and 10.06 ng/spot, respectively and for bacoside A 8.3 and 27.39 ng/spot, respectively. The proposed method can be successfully used to determine the drug content of marketed formulation.

  17. Simple, Rapid Mycobacterium ulcerans Disease Diagnosis from Clinical Samples by Fluorescence of Mycolactone on Thin Layer Chromatography.

    Directory of Open Access Journals (Sweden)

    Anita Wadagni

    2015-11-01

    Full Text Available Mycobacterium ulcerans infection, known as Buruli ulcer, is a disease of the skin and subcutaneous tissues which is an important but neglected tropical disease with its major impact in rural parts of West and Central Africa where facilities for diagnosis and management are poorly developed. We evaluated fluorescent thin layer chromatography (f-TLC for detection of mycolactone in the laboratory using samples from patients with Buruli ulcer and patients with similar lesions that gave a negative result on PCR for the IS2404 repeat sequence of M. ulcerans.Mycolactone and DNA extracts from fine needle aspiration (FNA, swabs and biopsy specimen were used to determine the sensitivity and specificity of f-TLC when compared with PCR for the IS2404. For 71 IS2404 PCR positive and 28 PCR negative samples the sensitivity was 73.2% and specificity of 85.7% for f-TLC. The sensitivity was similar for swabs (73%, FNAs (75% and biopsies (70%.We have shown that mycolactone can be detected from M. ulcerans infected skin tissue by f-TLC technique. The technique is simple, easy to perform and read with minimal costs. In this study it was undertaken by a member of the group from each endemic country. It is a potentially implementable tool at the district level after evaluation in larger field studies.

  18. Comparative study on the inclusion behaviour of cyclodextrin derivatives with venoruton and rutin by thin layer chromatography.

    Science.gov (United States)

    Guo, Xiliang; Shuang, Shaomin; Wang, Xiaoping; Dong, Chuan; Pan, Jinghao; Aboul-Enein, Hassan Y

    2004-10-01

    The interaction of rutin and venoruton (troxerutin), with alpha-, beta- and gamma-cyclodextrin (CD), hydroxypropyl-beta-cyclodextrin (HP-beta-CD) and methyl-beta-cyclodextrin (M-beta-CD) was investigated by reversed-phase thin layer chromatography on polyamide plates. A mobile phase consisted of NH(4)OH; NH(4)Cl buffer solution containing various CD concentrations (pH = 9.7, 20 degrees C) was used as mobile phase. The equilibrium constants (K(f)) and the retention factor (R(f)) were determined and used to study the inclusion process. The in fluence of CDs on the solubility of rutin and venoruton was characterized by R(M) values and the increasing hydrophilicity of drugs. The results show that the inclusion capacity of cyclodextrins follows the order HP-beta-CD > M-beta-CD > beta-CD > gamma-CD, and rutin is more easily included by the studied cyclodextrins than venoruton. In addition, the thermodynamic parameters (Delta H, Delta S) for the formation of complexes were obtained from the van't Hoff equation, displaying the enthalpy-entropy compensation effect.

  19. Evaluation of group of Alpinia galanga n-hexane-Extract against Candida albicans by bioautography and thin layer chromatography

    Directory of Open Access Journals (Sweden)

    Eni Kusumaningtyas

    2008-12-01

    Full Text Available Alpinia galanga has been used for centuries as a remedy for human diseases because it contains of therapeutic compounds. The objectives of this study was to define groups of the antifungal compounds of Alpinia galangal n-hexane-extract. Alpinia galanga was extracted by maceration method and the compounds were analyzed by phytochemical analysis. The extract was run on the thin layer chromatography (TLC plate silica gel GF254 with dichloromethane and toluene. Bioautography was conducted to determine antifungal compounds against Candida albicans. Active compounds on the previous step were identified by running extract on TLC plate and sprayed with Vanilin sulphuric acid and Liebermann-Burchard I. The results of phytochemical analysis showed that Alpinia galanga n-hexane-extract contains alkaloids, flavonoids, saponins, triterpenoid, tannins and aromatic oil. Bioautogram revealed that there was one inhibition zone against Candida albicans. The active compounds in the inhibition zone were in Rf value 0.75 and 0.89. One out of the two compounds was identified as a compound from terpenoid group.

  20. A novel high-performance thin layer chromatography method for quantification of long chain aliphatic hydrocarbons from Cissus quadrangularis

    Directory of Open Access Journals (Sweden)

    Vandana Jain

    2016-08-01

    Full Text Available Context: A high-performance thin layer chromatography (HPTLC is an analytical technique, which can be used for the determination of constituents or marker components in various parts of the plants. Earlier studies have estimated phytoconstituents from the stem and other aerial plant parts of Cissus quadrangularis Linn. Estimation of hydrocarbons can also be successfully done using HPTLC technique using suitable derivatization. Aims: To develop and validate a simple and rapid method for the estimation of long chain aliphatic hydrocarbons from the leaves of C. quadrangularis using HPTLC technique. Methods: Precoated silica gel 60 F254 plates were used as stationary phase. The mobile phase used was hexane (100 %. The detection of spots was carried out using berberine sulphate as detecting reagent. Results: The method was validated in terms of linearity, sensitivity, accuracy, and precision. Linearity range was found to be 2-10 µg/mL, limit of detection 0.127 µg/mL, and limit of quantification 0.384 µg/mL. Conclusions: A novel, simple, accurate, precise and sensitive HPTLC method has been developed and validated for the estimation of long chain aliphatic hydrocarbons obtained from the leaves of C. quadrangularis Linn.

  1. High performance thin layer chromatography fingerprinting, phytochemical and physico-chemical studies of anti-diabetic herbal extracts

    Science.gov (United States)

    Itankar, Prakash R.; Sawant, Dattatray B.; Tauqeer, Mohd.; Charde, Sonal S.

    2015-01-01

    Introduction: Herbal medicines have gained increasing popularity in the last few decades, and this global resurgence of herbal medicines increases their commercial value. However, this increasing demand has resulted in a decline in their quality, primarily due to a lack of adequate regulations pertaining to herbal medicines. Aim: To develop an optimized methodology for the standardization of herbal raw materials. Materials and Methods: The present study has been designed to examine each of the five herbal anti-diabetic drugs, Gymnema sylvester R. Br., Pterocarpus marsupium Roxburgh., Enicostema littorale Blume., Syzygium cumini (L.) Skeels. and Emblica officinalis Gaertn. The in-house extracts and marketed extracts were evaluated using physicochemical parameters, preliminary phytochemical screening, quantification of polyphenols (Folin–Ciocalteu colorimetric method) and high performance thin layer chromatography (HPTLC) fingerprint profiling with reference to marker compounds in plant extracts. Results: All the plants mainly contain polyphenolic compounds and are quantified in the range of 3.6–21.72% w/w. E. officinalis contain the highest and E. littorale contain the lowest content of polyphenol among plant extracts analyzed. HPTLC fingerprinting showed that the in-house extracts were of better quality than marketed extracts. Conclusion: The results obtained from the study could be utilized for setting limits for the reference phytoconstituents (biomarker) for the quality control and quality assurance of these anti-diabetic drugs. PMID:27011722

  2. Development and validation of high-performance liquid chromatography and high-performance thin-layer chromatography methods for the quantification of khellin in Ammi visnaga seed

    Directory of Open Access Journals (Sweden)

    Abid Kamal

    2015-01-01

    Full Text Available Objective: The present study was used to design simple, accurate and sensitive reversed phase-high-performance liquid chromatography RP-HPLC and high-performance thin-layer chromatography (HPTLC methods for the development of quantification of khellin present in the seeds of Ammi visnaga. Materials and Methods: RP-HPLC analysis was performed on a C18 column with methanol: Water (75: 25, v/v as a mobile phase. The HPTLC method involved densitometric evaluation of khellin after resolving it on silica gel plate using ethyl acetate: Toluene: Formic acid (5.5:4.0:0.5, v/v/v as a mobile phase. Results: The developed HPLC and HPTLC methods were validated for precision (interday, intraday and intersystem, robustness and accuracy, limit of detection and limit of quantification. The relationship between the concentration of standard solutions and the peak response was linear in both HPLC and HPTLC methods with the concentration range of 10–80 μg/mL in HPLC and 25–1,000 ng/spot in HPTLC for khellin. The % relative standard deviation values for method precision was found to be 0.63–1.97%, 0.62–2.05% in HPLC and HPTLC for khellin respectively. Accuracy of the method was checked by recovery studies conducted at three different concentration levels and the average percentage recovery was found to be 100.53% in HPLC and 100.08% in HPTLC for khellin. Conclusions: The developed HPLC and HPTLC methods for the quantification of khellin were found simple, precise, specific, sensitive and accurate which can be used for routine analysis and quality control of A. visnaga and several formulations containing it as an ingredient.

  3. Thin Layer Chromatography-Bioautography and Gas Chromatography-Mass Spectrometry of Antimicrobial Leaf Extracts from Philippine Piper betle L. against Multidrug-Resistant Bacteria

    Directory of Open Access Journals (Sweden)

    Demetrio L. Valle

    2016-01-01

    Full Text Available This study isolated and identified the antimicrobial compounds of Philippine Piper betle L. leaf ethanol extracts by thin layer chromatography- (TLC- bioautography and gas chromatography-mass spectrometry (GC-MS. Initially, TLC separation of the leaf ethanol extracts provided a maximum of eight compounds with Rf values of 0.92, 0.86, 0.76, 0.53, 0.40, 0.25, 0.13, and 0.013, best visualized when inspected under UV 366 nm. Agar-overlay bioautography of the isolated compounds demonstrated two spots with Rf values of 0.86 and 0.13 showing inhibitory activities against two Gram-positive multidrug-resistant (MDR bacteria, namely, methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococcus. The compound with an Rf value of 0.86 also possessed inhibitory activity against Gram-negative MDR bacteria, namely, carbapenem-resistant Enterobacteriaceae-Klebsiella pneumoniae and metallo-β-lactamase-producing Acinetobacter baumannii. GC-MS was performed to identify the semivolatile and volatile compounds present in the leaf ethanol extracts. Six compounds were identified, four of which are new compounds that have not been mentioned in the medical literature. The chemical compounds isolated include ethyl diazoacetate, tris(trifluoromethylphosphine, heptafluorobutyrate, 3-fluoro-2-propynenitrite, 4-(2-propenylphenol, and eugenol. The results of this study could lead to the development of novel therapeutic agents capable of dealing with specific diseases that either have weakened reaction or are currently not responsive to existing drugs.

  4. Thin Layer Chromatography-Bioautography and Gas Chromatography-Mass Spectrometry of Antimicrobial Leaf Extracts from Philippine Piper betle L. against Multidrug-Resistant Bacteria.

    Science.gov (United States)

    Valle, Demetrio L; Puzon, Juliana Janet M; Cabrera, Esperanza C; Rivera, Windell L

    2016-01-01

    This study isolated and identified the antimicrobial compounds of Philippine Piper betle L. leaf ethanol extracts by thin layer chromatography- (TLC-) bioautography and gas chromatography-mass spectrometry (GC-MS). Initially, TLC separation of the leaf ethanol extracts provided a maximum of eight compounds with R f values of 0.92, 0.86, 0.76, 0.53, 0.40, 0.25, 0.13, and 0.013, best visualized when inspected under UV 366 nm. Agar-overlay bioautography of the isolated compounds demonstrated two spots with R f values of 0.86 and 0.13 showing inhibitory activities against two Gram-positive multidrug-resistant (MDR) bacteria, namely, methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococcus. The compound with an R f value of 0.86 also possessed inhibitory activity against Gram-negative MDR bacteria, namely, carbapenem-resistant Enterobacteriaceae-Klebsiella pneumoniae and metallo-β-lactamase-producing Acinetobacter baumannii. GC-MS was performed to identify the semivolatile and volatile compounds present in the leaf ethanol extracts. Six compounds were identified, four of which are new compounds that have not been mentioned in the medical literature. The chemical compounds isolated include ethyl diazoacetate, tris(trifluoromethyl)phosphine, heptafluorobutyrate, 3-fluoro-2-propynenitrite, 4-(2-propenyl)phenol, and eugenol. The results of this study could lead to the development of novel therapeutic agents capable of dealing with specific diseases that either have weakened reaction or are currently not responsive to existing drugs.

  5. Qualitative and quantitative analysis of four species of Curcuma rhizomes using twice development thin layer chromatography.

    Science.gov (United States)

    Zhang, J S; Guan, J; Yang, F Q; Liu, H G; Cheng, X J; Li, S P

    2008-11-04

    The rhizomes of Curcuma phaeocaulis, Curcuma kwangsiensis, Curcuma wenyujin and Curcuma longa are used as Ezhu or Jianghuang in traditional Chinese medicine for a long time. Due to their similar morphological characters, it is difficult to distinguish their origins of raw materials used in clinic. In this study, a simple, rapid and reliable twice development TLC method was developed for qualitative and quantitative analysis of the four species of Curcuma rhizomes. The chromatography was performed on silica gel 60F(254) plate with chloroform-methanol-formic acid (80:4:0.8, v/v/v) and petroleum ether-ethyl acetate (90:10, v/v) as mobile phase for twice development. The TLC markers were colorized with 1% vanillin-H(2)SO(4) solution. The four species of Curcuma were easily discriminated based on their characteristic TLC profiles, and simultaneous quantification of eight compounds, including bisdemethoxycurcumin, demethoxycurcumin, curcumine, curcumenol, curcumol, curdione, furanodienone and curzerene, in Curcuma were also performed densitometrically at lambda(scan)=518nm and lambda(reference)=800 nm. The investigated compounds had good linearity (r(2)>0.9905) within test ranges. Therefore, the developed TLC method can be used for quality control of Curcuma rhizomes.

  6. Employment of High-Performance Thin-Layer Chromatography for the Quantification of Oleuropein in Olive Leaves and the Selection of a Suitable Solvent System for Its Isolation with Centrifugal Partition Chromatography.

    Science.gov (United States)

    Boka, Vasiliki-Ioanna; Argyropoulou, Aikaterini; Gikas, Evangelos; Angelis, Apostolis; Aligiannis, Nektarios; Skaltsounis, Alexios-Leandros

    2015-11-01

    A high-performance thin-layer chromatographic methodology was developed and validated for the isolation and quantitative determination of oleuropein in two extracts of Olea europaea leaves. OLE_A was a crude acetone extract, while OLE_AA was its defatted residue. Initially, high-performance thin-layer chromatography was employed for the purification process of oleuropein with fast centrifugal partition chromatography, replacing high-performance liquid-chromatography, in the stage of the determination of the distribution coefficient and the retention volume. A densitometric method was developed for the determination of the distribution coefficients, KC = CS/CM. The total concentrations of the target compound in the stationary phase (CS) and in the mobile phase (CM) were calculated by the area measured in the high-performance thin-layer chromatogram. The estimated Kc was also used for the calculation of the retention volume, VR, with a chromatographic retention equation. The obtained data were successfully applied for the purification of oleuropein and the experimental results confirmed the theoretical predictions, indicating that high-performance thin-layer chromatography could be an important counterpart in the phytochemical study of natural products. The isolated oleuropein (purity > 95%) was subsequently used for the estimation of its content in each extract with a simple, sensitive and accurate high-performance thin-layer chromatography method. The best fit calibration curve from 1.0 µg/track to 6.0 µg/track of oleuropein was polynomial and the quantification was achieved by UV detection at λ 240 nm. The method was validated giving rise to an efficient and high-throughput procedure, with the relative standard deviation % of repeatability and intermediate precision not exceeding 4.9% and accuracy between 92% and 98% (recovery rates). Moreover, the method was validated for robustness, limit of quantitation, and limit of detection. The amount of oleuropein for

  7. A comparative study on various spectrometries with thin layer chromatography for simultaneous analysis of drotaverine and nifuroxazide in capsules.

    Science.gov (United States)

    Ayad, Magda Mohammed; Youssef, Nadia Fayek; Abdellatif, Hisham Ezzat; Soliman, Suzan Mahmod

    2006-06-01

    Three spectrophotometric methods including Vierordt's method, derivative, ratio spectra derivative, and thin layer chromatography (TLC)-UV densitometric method were developed for simultaneous determination of drotaverine HCl (DRT) and nifuroxazide (NIF) in presence of its impurity, 4-hydroxybenzohydrazide (4-HBH). In Vierordt's method, (E(1 cm)(1%)) values were calculated at 227 and 368 nm in the zero-order spectra of DRT and NIF. By derivative spectrophotometry, the zero-crossing method, drotaverine HCl was determined using the second derivative at 245 nm and the third derivative at 238 nm, while nifuroxazide was determined using the first derivative at 399 nm and the second derivative at 411 nm. The ratio spectra derivative spectrophotometry is based on the measure of the amplitude at 459 nm for DRT and at 416 nm for NIF in the first derivative of the ratio spectra. Calibration graphs of the three spectrophotometric methods were plotted in the range 1-10 microg/ml of DRT and 2-20 microg/ml of NIF. TLC-UV densitometric method was achieved on silica gel plates using ethyl acetate : methanol : ammonia 33% (10 : 1 : 0.1 v/v/v) as the mobile phase. The Rf values were 0.74, 0.50, 0.30+/-0.01 for DRT, NIF and 4-HBH, respectively. On the fluorescent plates, the spots were located by fluorescence quenching and the densitometrical area were measured at 308 and 287 nm with linear range 0.2-4 microg/spot and 0.6-12 microg/spot for DRT and NIF, respectively. The proposed methods have been successfully applied to the commercial pharmaceutical formulation without any interference of excipients. Mean recoveries, relative standard deviations and the results of the proposed methods were compared with those obtained by applying the alternate methods.

  8. Quantitative Characterization of Gold Nanoparticles by Coupling Thin Layer Chromatography with Laser Ablation Inductively Coupled Plasma Mass Spectrometry.

    Science.gov (United States)

    Yan, Neng; Zhu, Zhenli; Jin, Lanlan; Guo, Wei; Gan, Yiqun; Hu, Shenghong

    2015-06-16

    Metal nanoparticles (NPs) determination has recently attracted considerable attention because of the continuing boom of nanotechnology. In this study, a novel method for separation and quantitative characterization of NPs in aqueous suspension was established by coupling thin layer chromatography (TLC) with laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). Gold nanoparticles (AuNPs) of various sizes were used as the model system. It was demonstrated that TLC not only allowed separation of gold nanoparticles from ionic gold species by using acetyl acetone/butyl alcohol/triethylamine (6:3:1, v/v) as the mobile phase, but it also achieved the separation of differently sized gold nanoparticles (13, 34, and 47 nm) by using phosphate buffer (0.2 M, pH = 6.8), Triton X-114 (0.4%, w/v), and EDTA (10 mM) as the mobile phase. Various experimental parameters that affecting TLC separation of AuNPs, such as the pH of the phosphate buffer, the coating of AuNPs, the concentrations of EDTA and Triton X-114, were investigated and optimized. It was found that separations of AuNPs by TLC displayed size dependent retention behavior with good reproducibility, and the retardation factors (R(f) value) increased linearly with decreasing nanoparticle size. The analytical performance of the present method was evaluated under optimized conditions. The limits of detection were in the tens of pg range, and repeatability (RSD, n = 7) was 6.3%, 5.9%, and 8.3% for 30 ng of 13 nm AuNPs, 34 nm AuNPs, and 47 nm AuNPs, respectively. The developed TLC-LA-ICP-MS method has also been applied to the analysis of spiked AuNPs in lake water, river water, and tap water samples.

  9. Simultaneous Determination of Size and Quantification of Gold Nanoparticles by Direct Coupling Thin layer Chromatography with Catalyzed Luminol Chemiluminescence

    Science.gov (United States)

    Yan, Neng; Zhu, Zhenli; He, Dong; Jin, Lanlan; Zheng, Hongtao; Hu, Shenghong

    2016-04-01

    The increasing use of metal-based nanoparticle products has raised concerns in particular for the aquatic environment and thus the quantification of such nanomaterials released from products should be determined to assess their environmental risks. In this study, a simple, rapid and sensitive method for the determination of size and mass concentration of gold nanoparticles (AuNPs) in aqueous suspension was established by direct coupling of thin layer chromatography (TLC) with catalyzed luminol-H2O2 chemiluminescence (CL) detection. For this purpose, a moving stage was constructed to scan the chemiluminescence signal from TLC separated AuNPs. The proposed TLC-CL method allows the quantification of differently sized AuNPs (13 nm, 41 nm and 100 nm) contained in a mixture. Various experimental parameters affecting the characterization of AuNPs, such as the concentration of H2O2, the concentration and pH of the luminol solution, and the size of the spectrometer aperture were investigated. Under optimal conditions, the detection limits for AuNP size fractions of 13 nm, 41 nm and 100 nm were 38.4 μg L‑1, 35.9 μg L‑1 and 39.6 μg L‑1, with repeatabilities (RSD, n = 7) of 7.3%, 6.9% and 8.1% respectively for 10 mg L‑1 samples. The proposed method was successfully applied to the characterization of AuNP size and concentration in aqueous test samples.

  10. Quick identification of xanthine oxidase inhibitor and antioxidant from Erycibe obtusifolia by a drug discovery platform composed of multiple mass spectrometric platforms and thin-layer chromatography bioautography.

    Science.gov (United States)

    Chen, Zhiyong; Tao, Hongxun; Liao, Liping; Zhang, Zijia; Wang, Zhengtao

    2014-08-01

    As a final step of the purine metabolism process, xanthine oxidase catalyzes the oxidation of hypoxanthine and xanthine into uric acid. Our research has demonstrated that Erycibe obtusifolia has xanthine oxidase inhibitory properties. The purpose of this paper is to describe a new strategy based on a combination of multiple mass spectrometric platforms and thin-layer chromatography bioautography for effectively screening the xanthine oxidase inhibitory and antioxidant properties of E. obtusifolia. This strategy was accomplished through the following steps. (i) Separate the extract of E. obtusifolia into fractions by an autopurification system controlled by liquid chromatography with mass spectrometry. (ii) Determine the active fractions of E. obtusifolia by thin-layer chromatography bioautography. (iii) Identify the structure of the main active compounds with the information provided by direct analysis in real time mass spectrometry. (iv) Calculate the IC50 value of each compound against xanthine oxidase using high-performance liquid chromatography. Using the caulis of E. obtusifolia as the experimental material, seven target peaks were screened out as xanthine oxidase inhibitors or antioxidants. Our screening strategy allows for rapid analysis of small molecules with almost no sample preparation and can be completed within a week, making it a useful assay to identify unstable compounds and provide the empirical foundation for E. obtusifolia as a natural remedy for gout and oxidative-stress-related diseases.

  11. Standardisation of Gymnema sylvestre R.Br. by high-performance thin-layer chromatography: an improved method.

    Science.gov (United States)

    Raju, Valivarthi S R; Kannababu, S; Subbaraju, Gottumukkala V

    2006-01-01

    An improved high-performance thin-layer chromatographic (HPTLC) method for the standardisation of Gymnema sylvestre is reported. The method involves the initial hydrolysis of gymnemic acids, the active ingredients, to a common aglycone followed by the quantitative estimation of gymnemagenin. The present method rectifies an error found in an HPTLC method reported recently.

  12. The detection of some halogenated phenols and nitrophenols in thin-layer chromatography by means of bromine

    NARCIS (Netherlands)

    Tadema, G.; Batelaan, P.H.

    1968-01-01

    A method is described for the detection of halogeno- and nitro-phenols in sub-microgram quantities. Theses compounds are made visible by exposure of the developed thin layer plates to bromine vapour and subsequent spraying with an aqueous solution of potassium iodide or an ethanolic solution of fluo

  13. Quantitative Thin-Layer Chromatography/Mass Spectrometry Analysis of Caffeine Using a Surface Sampling Probe Electrospray Ionization Tandem Mass Spectrometry System

    Energy Technology Data Exchange (ETDEWEB)

    Ford, Michael J [ORNL; Deibel, Michael A. [Earlham College; Tomkins, Bruce A [ORNL; Van Berkel, Gary J [ORNL

    2005-01-01

    Quantitative determination of caffeine on reversed-phase C8 thin-layer chromatography plates using a surface sampling electrospray ionization system with tandem mass spectrometry detection is reported. The thin-layer chromatography/electrospray tandem mass spectrometry method employed a deuterium-labeled caffeine internal standard and selected reaction monitoring detection. Up to nine parallel caffeine bands on a single plate were sampled in a single surface scanning experiment requiring 35 min at a surface scan rate of 44 {mu}m/s. A reversed-phase HPLC/UV caffeine assay was developed in parallel to assess the mass spectrometry method performance. Limits of detection for the HPLC/UV and thin-layer chromatography/electrospray tandem mass spectrometry methods determined from the calibration curve statistics were 0.20 ng injected (0.50 {mu}L) and 1.0 ng spotted on the plate, respectively. Spike recoveries with standards and real samples ranged between 97 and 106% for both methods. The caffeine content of three diet soft drinks (Diet Coke, Diet Cherry Coke, Diet Pepsi) and three diet sport drinks (Diet Turbo Tea, Speed Stack Grape, Speed Stack Fruit Punch) was measured. The HPLC/UV and mass spectrometry determinations were in general agreement, and these values were consistent with the quoted values for two of the three diet colas. In the case of Diet Cherry Coke and the diet sports drinks, the determined caffeine amounts using both methods were consistently higher (by 8% or more) than the literature values.

  14. Óleo essencial de limão no ensino da cromatografia em camada delgada Lime essential oil in the teaching of thin layer chromatography

    Directory of Open Access Journals (Sweden)

    Rosaly S. Silva

    2009-01-01

    Full Text Available This paper describes a simple experiment employing the essential oil of limes which can be applied in undergraduate organic chemistry laboratory classes for the teaching of thin layer chromatography (TLC. The experiment consists in submit lime peel oil to TLC separation employing hexane and dichloromethane as the eluents and five different systems for visualization of the chromatogram. In one experiment it is possible to teach the different variables of the TLC technique. This experiment may also be performed following vapor distillation and liquid-liquid extraction technique in experimental classes.

  15. Simplified and rapid method for extraction of ergosterol from natural samples and detection with quantitative and semi-quantitative methods using thin-layer chromatography

    OpenAIRE

    2004-01-01

    A new and simplified method for extraction of ergosterol (ergoste-5,7,22-trien-3-beta-ol) from fungi in soil and litter was developed using pre-soaking extraction and paraffin oil for recovery. Recoveries of ergosterol were in the range of 94 - 100% depending on the solvent to oil ratio. Extraction efficiencies equal to heat-assisted extraction treatments were obtained with pre-soaked extraction. Ergosterol was detected with thin-layer chromatography (TLC) using fluorodensitometry with a quan...

  16. [Process analysis for levulinic acid generated in waste wood liquefaction by non-development thin-layer chromatography based on oblique projection].

    Science.gov (United States)

    Su, Hui; Ge, Jun; Fang, Feng; Yao, Zhixiang; Song, Guangjun

    2014-01-01

    A rapid and quantitative method is presented for multi-component process analysis, based on multi-wavelength thin-layer chromatography (TLC) scanning but without the routine development. The samples from the waste wood liquefaction process are applied on silica plates, and just the last sample of spot need to be developed for getting separated spectra. These spectra are divided into two parts of production (levulinic acid) and background, respectively, to build an oblique projection operator. The other process samples do not need to be developed repeatedly, and are scanned to collect hybrid spectra immediately. The pure production spectrum can be separated from the process spectrum by the oblique projection algorithms to realize the production quantification. It was showed that the relative errors between the determination results by this method and those by high performance liquid chromatography (HPLC) were less than 3.27%, and so the consistency is perfect.

  17. Comparison of thin-layer chromatography, spectrofluorimetry and bright greenish-yellow fluorescence test for aflatoxin detection in corn

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    Elisabete Yurie Sataque Ono

    2010-06-01

    Full Text Available In this study the bright greenish-yellow fluorescence test, widely used by the corn milling industry, was compared to the thin-layer chromatography (TLC and spectrofluorimetry methods for aflatoxin detection in 40 corn samples naturally contaminated by the Aspergillus section Flavi. According to the corn processing industry criteria, all the samples were adequate for human and animal consumption by the bright greenish-yellow fluorescence test, but TLC and spectrofluorimetry analysis detected aflatoxins above the maximum tolerated limit (20 µg/kg in 7 and 8 samples, respectively. Aflatoxins were detected in 16 (40% corn samples by TLC, with levels ranging from 4.0 to 54.0 µg/kg (mean 19.97 ± 15.97 µg/kg, and in 25 (62.5% samples by spectrofluorimetry, with levels ranging from 1.0 to 58.66 µg/kg (mean 17.14 ± 17.81 µg/kg. The results indicated a good correlation (ρ = 0.97 between TLC and spectrofluorimetry for aflatoxin determination in naturally contaminated corn. The bright greenish-yellow fluorescence test was simple and quick, but it showed 20% false-negative results, suggesting its use only as screening method for detecting the suspected lots of grains that should be tested further for aflatoxin by more sensitive methods.Neste trabalho a contagem de fluorescência luminosa amarelo-esverdeada, amplamente utilizada pela indústria de processamento de milho, foi comparada à cromatografia em camada delgada (CCD e espectrofluorimetria para detecção de aflatoxinas em 40 amostras de milho naturalmente contaminadas por Aspergillus section Flavi. De acordo com os critérios da indústria processadora de milho, todas as amostras estavam adequadas para o consumo humano e animal pela contagem de fluorescência luminosa amarelo-esverdeada (CFLAE, porém as análises por CCD e espectrofluorimetria detectaram aflatoxinas acima do limite máximo tolerado (20 µg/kg em 7 e 8 amostras, respectivamente. As aflatoxinas foram detectadas em 16 (40

  18. Marker based standardization of polyherbal formulation (SJT-DI-02 by high performance thin layer chromatography method

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    Bhakti J Ladva

    2014-01-01

    purity of the bands due to marker compounds in the sample extracts were confirmed by overlaying the absorption spectra recorded at start, middle and end position of the band in the sample tracks. After conforming all these things fingerprints were developed for all three formulations which will be act as authentification and quality control tool. Results: % w/w of asarones is 3.61, % w/w of marmelosin is 4.60, % w/w of gallic acid is 10.80 and % w/w of lupeol is 4.13.The method was validated in terms of linearity, precision, repeatability, limit of detection, limit of quantification and accuracy. In well-developed mobile phase system linearity was found to be in the range of 0.983-0.995, % recovery was found to be in the range of 97.48-99.63, % RSD for intraday and interday was found to be 0.13- 0.70 and 0.32 -1.41 and LOD and LOQ was found to be in the range of 0.15- 0.61 and 0.45 -1.83 microgram per ml. Conclusion: Thus High performance thin layer chromatography (HPTLC methods were developed and validated in terms of linearity, precision, repeatability, limit of detection, limit of quantification and accuracy. The methods were rapid, sensitive, reproducible and economical. It does not suffer any positive or negative interference due to common other component present in the formulation and would also serve as a tool for authentication of herbal products containing marmelosin, gallic acid, lupeol and asarones. Thus this work provides standardized and therapeutically active polyherbal formulations for the different ailments.

  19. A simple analytical platform based on thin-layer chromatography coupled with paper-based analytical device for determination of total capsaicinoids in chilli samples.

    Science.gov (United States)

    Dawan, Phanphruk; Satarpai, Thiphol; Tuchinda, Patoomratana; Shiowatana, Juwadee; Siripinyanond, Atitaya

    2017-01-01

    A new analytical platform based on the use of thin-layer chromatography (TLC) coupled with paper-based analytical device (PAD) was developed for the determination of total capsaicinoids in chilli samples. This newly developed TLC-PAD is simple and low-cost without any requirement of special instrument or skillful person. The analysis consisted of two steps, i.e., extraction of capsaicinoids from chilli samples by using ethanol as solvent and separation of capsaicinoids by thin-layer chromatography (TLC) and elution of capsaicinoids from the TLC plate with in situ colorimetric detection of capsaicinoids on the PAD. For colorimetric detection, Folin-Ciocalteu reagent was used to detect phenolic functional group of capsaicinoids yielding the blue color. The blue color on the PAD was imaged by a scanner followed by evaluation of its grayscale intensity value by ImageJ program. This newly developed TLC-PAD method provided a linear range from 50 to 1000mgL(-1) capsaicinoids with the limit of detection as low as 50mgL(-1) capsaicinoids. The proposed method was applied to determine capsaicinoids in dried chilli and seasoning powder samples and the results were in good agreement with those obtained by HPLC method.

  20. Rapid validated high performance thin layer chromatography method for simultaneous estimation of mangiferin and scopoletin in Canscora decussata (South Indian Shankhpushpi extract

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    Neeraj K. Sethiya

    2015-06-01

    Full Text Available AbstractMangiferin (polyphenolic xanthone and scopoletin (phenolic coumarin are well-studied biological markers present in Canscora decussata(Roxb. Roem. & Schult., Gentianaceae. The objective set for the present studies is to establish and develop a new, simple, selective, sensitive, and precise high performance thin layer chromatography method for the simultaneous estimation of mangiferin and scopoletin in hydroalcoholic extract of C. decussata. The thin layer chromatographic separation of these biomarkers was carried out on aluminum plate pre-coated with silica gel 60F254, eluted with ethyl acetate:acetic acid:formic acid:water (10:0.5:0.5:1.5. The plate was then dried and densitometric scanning was performed at 254 nm using a Camag TLC scanner III. The system was found to give compact spots for mangiferin (RF 0.22 and scopoletin (RF 0.78. A good relationship of linear precision between the concentrations (100–600 ng/spot and peak areas was obtained with correlation coefficient (r of 0.9979 (mangiferin and 0.9962 (scopoletin, respectively. The limits of detection and limit of quantification were determined to be 46 and 94 ng/spot for mangiferin and 31 and 78 ng/spot for scopoletin respectively. The percentage of recovery was found from 99.91 to 99.94% for mangiferin and 99.75 to 99.86% for scopoletin. Results obtained from recovery studies showed excellent reliability and reproducibility of the method. Present communication on validated high performance thin layer chromatography method may provide a new, selective, sensitive, and precise method to estimate mangiferin and scopoletin as phytomarkers in the hydroalcoholic extract of C. decussata used in Ayurvedic formulations.

  1. STUDY ON THE SEPARATION THROUGH THIN LAYER CHROMATOGRAPHY OF THE CHOLESTEROL IN THE BUFFALO MILK ORIGINATING IN THE MESENDORF FARM

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    AURELIA PECE

    2013-12-01

    Full Text Available Within the present study, we conducted a thin layer chromatographic separation of neuter fats in buffalo milk, following sodium metoxyde saponification and the exposition to λ=366 nm. The extraction of free and esterized milk cholesterol was conducted according to the Folch et al. (1957 method. The free and esterized cholesterol, as well as triglycerids appear as brown spots (iodine complexes with the double connections between the compounds under anlysis. Qualitative identification was conducted through the comparison of Rfs for free and esterized cholesterol, in the samples analyzed with existing standards. The semi-quantitative anlysis was conducted through a visual comparison of the intensity encountered in free cholesterol spots within samples under anlysis and the standard of different concentrations applied on the same board. Buffalo milk samples originated in the Mesendorf Farm, considered and certified as an ecologic farm.

  2. Tea tree oil concentration in follicular casts after topical delivery: determination by high-performance thin layer chromatography using a perfused bovine udder model.

    Science.gov (United States)

    Biju, S S; Ahuja, Alka; Khar, Roop K

    2005-02-01

    Tea tree oil, a popular antimicrobial agent is recommended for the treatment of acne vulgaris, a disease of the pilosebaceous unit. Tea tree oil formulations (colloidal bed, microemulsion, multiple emulsion, and liposomal dispersion containing 5% w/w tea tree oil) were applied to bovine udder skin. The follicular uptake of tea tree oil upon application was determined by a cyanoacrylate method. Tea tree oil was determined by quantifying terpinen-4-ol content using high-performance thin layer chromatography. The accumulation of tea tree oil in the follicular casts was 0.43 +/- 0.01, 0.41 +/- 0.009, 0.21 +/- 0.006, and 0.16 +/- 0.005 percentage by weight (milligram oil/gram of sebum plug) for microemulsion, liposomal dispersion, multiple emulsion, and colloidal bed, respectively. This is the first study of its kind to quantify tea tree oil concentration in the follicles.

  3. Quantification of Sunscreen Benzophenone-4 in Hair Shampoos by Hydrophilic Interactions Thin-Layer Chromatography/Densitometry or Derivative UV Spectrophotometry

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    Anna W. Sobańska

    2015-01-01

    Full Text Available Benzophenone-4 (BZ4 was separated from surfactants, dyes, preservatives, and other components of hair shampoos by thin-layer chromatography on silica gel 60 stationary phase, with ethyl acetate-ethanol-water-pH 6 phosphate buffer (15 : 7 : 5 : 1 v/v/v/v as mobile phase. Densitometry scanning of chromatograms was performed at 285 nm. The densitometric calibration curve for BZ4 was nonlinear (second-degree polynomial, with R>0.999. The limits of detection and quantification were ca. 0.03 and ca. 0.1 μg spot−1, respectively. The results obtained by HPTLC-densitometry were compared to those obtained by zero and 2nd derivative UV spectrophotometry. In the case of spectrophotometric methods, calibration curves were linear with R>0.9998. The chromatographic method was fully validated.

  4. Determination of neomycin in the form of neomycin derivative with dabsyl chloride by thin layer chromatography and densitometry.

    Science.gov (United States)

    Hubicka, Urszula; Zuromska-Witek, Barbara; Piotrowska, Joanna; Krzek, Jan

    2015-01-01

    A thin layer chromatographic-densitometric method has been developed for identification and quantitative determination of neomycin derivative with dabsyl chloride. The analysis of antibiotic was achieved on the silica gel TLC plates with fluorescent indicator with n-butanol--2-butanone--25% ammonia--water (10 : 6 : 2 : 2, v/v/v/v) as the mobile phase. The densitometric measurements were made at 460 nm. Under these conditions good separation of chosen aminoglycoside antibiotic from reagent used to make a complex was obtained. The method is characterized by high sensitivity, LOD from 0.1953 μg per band and LOQ from 0.5918 μg per band, wide linearity range from 0.5918 to 2.1960 μg per band for neomycin. The precision of the method was good; RSD varied from 1.17 to 2.05%. Satisfactory results of validation of the method were also confirmed by determination of selected antibiotic in pharmaceutical commercial preparation. The results obtained by TLC-densitometric method were compared with those obtained by spectrophotometric method.

  5. Analysis of phenolics in wine by high performance thin-layer chromatography with gradient elution and high resolution plate imaging.

    Science.gov (United States)

    Agatonovic-Kustrin, Snezana; Hettiarachchi, Chandima G; Morton, David W; Razic, Slavica

    2015-01-01

    Health benefits of wine, especially with red wine, have been linked to the presence of a wide range of phenolic antioxidants. Thus, the aim of this study was to develop a simple, high performance thin layer chromatographic (HPTLC) method combined with high resolution digital plate images to visually compare multiple wine samples simultaneously on a single chromatographic plate and to quantify levels of gallic acid, caffeic acid, resveratrol and rutin, as representatives of the four different classes of phenolics found in wines. We also wanted to investigate the contribution of the investigated phenolic compounds to the total polyphenolic content (TPC) and total antioxidant capacity (TAC) of the wine samples. The average concentrations of caffeic acid, gallic acid, resveratrol, and rutin in the red wines were 2.15, 30.17, 0.59 and 2.47 mg/L respectively with their concentration below limit of quantification in the white wine samples. The highest concentration of resveratrol and rutin is found in the Cabernet and Shiraz wine samples. The amounts of gallic acid are correlated with TPC (r=0.58). Italian wines have the highest correlation between TPC and TAC (r=0.99) although they do not contain detectable amounts of resveratrol, they contain significant amount of rutin. Therefore, antioxidant properties might be associated with the presence of flavanols in these wines.

  6. Application de la chromatographie sur couche mince à l'étude quantitative et qualitative des extraits de roches et des huiles Application of Thin-Layer Chromatography to the Quantitative and Qualitative Analysis of Rock and Oil Extracts

    Directory of Open Access Journals (Sweden)

    Huc A. Y.

    2006-11-01

    Full Text Available La technique développée ici répond à un besoin de miniaturisation des analyses des huiles et des extraits de roche. La chromatographie sur couche mince permet en effet l'analyse qualitative et quantitative de faibles quantités d'échantillons. On peut grace à cette méthode étudier les extraits obtenus à partir des cuttings (5 à 10 g de roche. Nous nous sommes attachés à faire une étude critique de l'information obtenue et de comparer cette dernière aux résultats fournis par les autres méthodes analytiques (chromatographie liquide. The technique described here meets the need to miniaturize analyses of ails and rock extracts. Thin-layer chromatography tan be used for the qualitative and quantitative analysis of small amounts of samples. This method is capable of onalyzing extracts from cuttings (5 ta 10 g of rock. This article attempts to make a critical study of the information obtained and to compare il with results using other analytical methods (liquid chromatography.

  7. Analysis of Bioactive Components of Oilseed Cakes by High-Performance Thin-Layer Chromatography-(Bioassay Combined with Mass Spectrometry

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    Sue-Siang Teh

    2015-03-01

    Full Text Available Hemp, flax and canola seed cakes are byproducts of the plant oil extraction industry that have not received much attention in terms of their potential use for human food instead of animal feed. Thus, the bioactivity profiling of these oilseed cakes is of interest. For their effect-directed analysis, planar chromatography was combined with several (bioassays, namely 2,2-diphenyl-1-picrylhydrazyl scavenging, acetylcholine esterase inhibition, planar yeast estrogen screen, antimicrobial Bacillus subtilis and Aliivibrio fischeri assays. The streamlined high-performance thin-layer chromatography (HPTLC-bioassay method allowed the discovery of previously unknown bioactive compounds present in these oilseed cake extracts. In contrast to target analysis, the direct link to the effective compounds allowed comprehensive information with regard to selected effects. HPTLC-electrospray ionization-mass spectrometry via the elution-head based TLC-MS Interface was used for a first characterization of the unknown effective compounds. The demonstrated bioactivity profiling on the feed/food intake side may guide the isolation of active compounds for production of functional food or for justified motivation of functional feed/food supplements.

  8. Stability-indicating reversed-phase high-performance thin-layer chromatography/densitometry estimation of lafutidine in bulk and tablets

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    Prajapati Nitin D.

    2013-01-01

    Full Text Available Lafutidine (LTD is a histamine H2 receptor antagonist, with anti-ulcer and mucosal protective activity. A sensitive and selective stability-indicating reversed- phase high -performance thin-layer chromatography (RP-HPTLC/Densitometry method is suggested for the determination of LTD in the presence of its acid, alkaline, oxidative and dry heat degradation products. Stress testing of LTD was done according to the International Conference on Harmonization (ICH guidelines in order to validate the stability-indicating power of the analytical procedures. Stress testing demonstrated that LTD underwent acid, alkaline, oxidative and dry heat degradation; on the other hand, it showed stability towards neutral and photo degradation. Chromatography was performed on aluminum-backed silica gel 60 RP-18 F254 S plates with Methanol: Water: Triethylamine 8: 2: 0.5 (v/v as mobile phase. Densitometric scanning was performed at 276 nm. The system gave compact bands for LTD (Rf 0.67 ± 0.02. Linear regression analysis data for the calibration plots discovered a good linear relationship with r2 > 0.99 in the working concentration range 500 to 3000 ng per band. The limits of detection and quantification were 23.51 ng and 71.26 ng, respectively. The developed method can routinely be used for analysis of LTD in bulk and pharmaceutical formulations.

  9. 双向薄层色谱法分析混合糖组分%Two-step thin layer chromatography for saccharides analysis of mixed saccharides liquid

    Institute of Scientific and Technical Information of China (English)

    刘秀花; 崔孟岐; 王莉; 张淑红; 宋兆齐; 梁峰

    2015-01-01

    薄层色谱法分析糖类混合物的组分简便快速,但是并不能将甘露糖、阿拉伯糖、半乳糖、木糖、葡萄糖进行彻底分离。本文采用双向层析的方法分别以V乙腈∶V水=85∶15为第一向展层剂,以V正丁醇∶V乙酸乙酯∶V水=7∶2∶1为第二向展层剂优化层析。结果显示,得到了较好的分离效果,可以定性检测出糖类组分。对比国内外研究,此方法简单,因此双向薄层色谱法可以作为一种简单、准确、清晰、便利的方法定性检测糖类混合物的组分。%The thin layer chromatography ( TLC) analysis of the mixed saccharides liquid composition effect is good , simple and rapid , but it doesn′t put the mannose , arabinose , galactose , xylose , glucose separately .This paper using the two step-TLC, the first step by Vacetonitrile∶Vwater =85∶15,and the second step by Vn-butanol∶V ethyl acetate∶V Water =7∶2∶1 as developing solvent for optimization of chromatography .Results show that using the above method to analyze saccharides mixture , got the good separation effect , can the qualitative detection of saccharides components , comparative research both at home and abroad , the use effect of the method is very simple and intuitive.Therefore, the two step thin layer chromatography ( TLC) can be used as a simple , accurate, clear and convenient method of qualitative detection of saccharide mixture components .

  10. 苦马豆生物碱成分薄层色谱分析%Alkaloid Content Analysis of Sphaerophysa salsula by Thin-layer Chromatography

    Institute of Scientific and Technical Information of China (English)

    白玛桑姆; 杨晓雯; 马烽; 周启武; 刘晓学; 王磊; 赵宝玉

    2014-01-01

    In order to determine whether Sphaerophysa salsula contains swainsonine and analysis alkaloid, we used alkaloid extraction,thin layer chromatography analysis techniques and software of planar chroma-tography for quantitative image.The results showed that 5 kg Sphaerophysa salsula got 650.2 g total ex-tract by the reflow method of industrial alcohol (the rate is 13%).We chose 200 g extract and then pro-cessed by acidification,alkalization,chloroform and n-butyl alcohol.We got extract 3.01 g,0.53 g and 23.13 g in the parts of acidity chloroform,basic chloroform and basic n-butyl alcohol (the rate is 1.51%, 0.27% and 11.57%).By thin layer chromatography analysis,we found that Sphaerophysa salsula con-tained at least 5 kinds of alkaloids in the parts of basic chloroform and basic n-butyl alcohol.Swainsonine was mainly in the part of basic n-butyl alcohol.We used the method of column chromatography on silica gel to isolate and purify this part,after comparing with swainsonine standard sample,our study found this part contained swainsonine.%为了确证苦马豆(Swainsona salsula )是否含有苦马豆素等生物碱成分,采用生物碱系统提取法、薄层色谱分析、平面色谱图像定量分析软件及柱层析分离等技术,对苦马豆生物碱成分进行分析和分离。结果显示,5 kg 苦马豆地上部分干草粉经工业酒精回流提取得到总浸膏650.2 g,出膏率为13%。取200 g醇浸膏分别经酸化和碱化处理,氯仿和正丁醇萃取得到,酸性氯仿、碱性氯仿和碱性正丁醇萃取液,浓缩后分别得到3.01、0.53、23.13 g,出膏率分别为1.51%、0.27%和11.57%;薄层色谱分析发现,碱性氯仿和碱性正丁醇萃取部分至少含有5种生物碱成分,且苦马豆生物碱主要集中在碱性正丁醇萃取部分;碱性正丁醇萃取部分经硅胶柱层析分离纯化,并与苦马豆素标准品对照证明其含有苦马豆素。

  11. Evaluation of thin-layer chromatography methods for quality control of commercial products containing Aesculus hippocastanum, Turnera diffusa, Matricaria recutita, Passiflora incarnata, and Tilia occidentalis.

    Science.gov (United States)

    Ramírez-Durón, Rosalba; Ceniceros-Almaguer, Lucía; Salazar-Aranda, Ricardo; Salazar-Cavazos, Ma de la Luz; Waksman de Torres, Noemi

    2007-01-01

    In Mexico, plant-derived products with health claims are sold as herbal dietary supplements, and there are no rules for their legal quality control. Aesculus hippocastanum, Turnera diffusa, Matricaria recutita, Passiflora incarnata, and Tilia occidentalis are some of the major commercial products obtained from plants used in this region. In this paper, we describe the effectiveness of thin-layer chromatography methods to provide for the quality control of several commercial products containing these plants. Standardized extracts were used. Of the 49 commercial products analyzed, only 32.65% matched the chromatographic characteristic of standardized extracts. A significant number of commercial products did not match their label, indicating a problem resulting from the lack of regulation for these products. The proposed methods are simple, sensitive, and specific and can be used for routine quality control of raw herbals and formulations of the tested plants. The results obtained show the need to develop simple and reliable analytical methods that can be performed in any laboratory for the purpose of quality control of dietary supplements or commercial herbal products sold in Mexico.

  12. Algerian mint species: high performance thin layer chromatography quantitative determination of rosmarinic acid and in vitro inhibitory effects on linoleic acid peroxidation

    Directory of Open Access Journals (Sweden)

    Brahmi Fatiha

    2014-12-01

    Full Text Available Objective: To determine the quantitative paremeters of rosmarinic acid in Algerian mints, Mentha spicata L. (M. spicata, Mentha pulegium L. and Mentha rotundifolia (L. Huds by high performance thin layer chromatography (HPTLC-densitometric method and screen the effects of these plant extracts on linoleic acid peroxidation. Methods: The analyses were performed on HPTLC silica gel 60 F254 plates with chloroform: acetone: formic acid (75:16.5:8.5, v/v as the mobile phase. Rosmarinic acid was determined in UV at 365 nm and fluorescence at λexc 325 nm with a 550 nm filter, respectively. The effects of plants extracts on linoleic acid peroxidation were measured by an indirect in vitro colorimetric method. Results: Chromatographic resolution permitted reliable quantification in both measurement modes and calibration curves were linear in a range of 150-1 000 ng/spot. M. spicata was found to contain significantly higher concentrations of rosmarinic acid. The densitometric quantification allowed the analysis of many samples in a short time with reasonable precision (total precision for Mentha spp extracts, 5.1% and 5.8% for UV and fluorescence detection, respectively. The HPTLC data, allied to assays of linoleic acid peroxidation prevention, suggested the potential of M. spicata (52% Trolox® equivalents as a natural source for inhibitors of lipid peroxidation. Conclusions: Densitometry can be used for routine determination and quality control of rosmarinic acid in herbal and formulations containing Mentha species.

  13. Thin layer chromatography-spray mass spectrometry: a method for easy identification of synthesis products and UV filters from TLC aluminum foils.

    Science.gov (United States)

    Himmelsbach, Markus; Waser, Mario; Klampfl, Christian W

    2014-06-01

    A straightforward procedure for direct mass spectrometric (MS) analysis of spots from thin layer chromatography (TLC) plates, without the need of an external ion source, was developed using the aluminum plate backing as spray tip. The spots were cut out shaped as a tip with a 60° angle, mounted in front of the MS orifice, and after addition of a spray solvent spectra were obtained immediately. A high-resolution time-of-flight MS was used since the method is of particular interest for rapid identification or confirmation of spots from TLC plates. The practical benefits of this technique were demonstrated by detection of by-products of organic reactions, by identification of degradation products, and by accurate confirmation of spots when UV filters in sunscreens were analyzed by TLC. Employing the described method TLC spots can be evaluated fast without the need of an external ion source or devices for analyte transfer from TLC to MS, only a basic MS instrument and a high-voltage power supply is required.

  14. Qualitative and quantitative high performance thin layer chromatography analysis of Calendula officinalis using high resolution plate imaging and artificial neural network data modelling.

    Science.gov (United States)

    Agatonovic-Kustrin, S; Loescher, Christine M

    2013-10-10

    Calendula officinalis, commonly known Marigold, has been traditionally used for its anti-inflammatory effects. The aim of this study was to investigate the capacity of an artificial neural network (ANN) to analyse thin layer chromatography (TLC) chromatograms as fingerprint patterns for quantitative estimation of chlorogenic acid, caffeic acid and rutin in Calendula plant extracts. By applying samples with different weight ratios of marker compounds to the system, a database of chromatograms was constructed. A hundred and one signal intensities in each of the HPTLC chromatograms were correlated to the amounts of applied chlorogenic acid, caffeic acid, and rutin using an ANN. The developed ANN correlation was used to quantify the amounts of 3 marker compounds in calendula plant extracts. The minimum quantifiable level (MQL) of 610, 190 and 940 ng and the limit of detection (LD) of 183, 57 and 282 ng were established for chlorogenic, caffeic acid and rutin, respectively. A novel method for quality control of herbal products, based on HPTLC separation, high resolution digital plate imaging and ANN data analysis has been developed. The proposed method can be adopted for routine evaluation of the phytochemical variability in calendula extracts.

  15. Detection and Estimation of alpha-Amyrin, beta-Sitosterol, Lupeol, and n-Triacontane in Two Medicinal Plants by High Performance Thin Layer Chromatography

    Directory of Open Access Journals (Sweden)

    Saikat S. Mallick

    2014-01-01

    Full Text Available A normal phase high performance thin layer chromatography (HPTLC method has been developed and validated for simultaneous estimation of four components, namely, alpha-amyrin, beta-sitosterol, lupeol, and n-triacontane from two medicinally important plants, Leptadenia reticulata Wight & Arn. and Pluchea lanceolata (DC. CB. Clarke. In Ayurveda, both plants have been reported to possess immunomodulatory activity. Chromatographic separation of the four components from the methanolic extracts of whole plant powders of Leptadenia reticulata Wight & Arn. and Pluchea lanceolata (DC. CB. Clarke. was performed on TLC aluminium plates precoated with silica gel 60F254 using a suitable mobile phase. The densitometric scanning was done after derivatization at λ = 580 nm for α-amyrin, β-sitosterol, and lupeol, and at 366 nm for n-triacontane. The developed HPTLC method has been validated and used for simultaneous quantitation of the four components from the methanolic extracts of whole plant powders of Leptadenia reticulata Wight & Arn. and Pluchea lanceolata (DC. CB. Clarke. The developed HPTLC method is simple, rapid, and precise and can be used for routine quality control.

  16. Building blocks for the development of an interface for high-throughput thin layer chromatography/ambient mass spectrometric analysis: a green methodology.

    Science.gov (United States)

    Cheng, Sy-Chyi; Huang, Min-Zong; Wu, Li-Chieh; Chou, Chih-Chiang; Cheng, Chu-Nian; Jhang, Siou-Sian; Shiea, Jentaie

    2012-07-17

    Interfacing thin layer chromatography (TLC) with ambient mass spectrometry (AMS) has been an important area of analytical chemistry because of its capability to rapidly separate and characterize the chemical compounds. In this study, we have developed a high-throughput TLC-AMS system using building blocks to deal, deliver, and collect the TLC plate through an electrospray-assisted laser desorption ionization (ELDI) source. This is the first demonstration of the use of building blocks to construct and test the TLC-MS interfacing system. With the advantages of being readily available, cheap, reusable, and extremely easy to modify without consuming any material or reagent, the use of building blocks to develop the TLC-AMS interface is undoubtedly a green methodology. The TLC plate delivery system consists of a storage box, plate dealing component, conveyer, light sensor, and plate collecting box. During a TLC-AMS analysis, the TLC plate was sent to the conveyer from a stack of TLC plates placed in the storage box. As the TLC plate passed through the ELDI source, the chemical compounds separated on the plate would be desorbed by laser desorption and subsequently postionized by electrospray ionization. The samples, including a mixture of synthetic dyes and extracts of pharmaceutical drugs, were analyzed to demonstrate the capability of this TLC-ELDI/MS system for high-throughput analysis.

  17. Two-dimensional thin-layer chromatography with adsorbent gradient as a method of chromatographic fingerprinting of furanocoumarins for distinguishing selected varieties and forms of Heracleum spp.

    Science.gov (United States)

    Cieśla, Lukasz; Bogucka-Kocka, Anna; Hajnos, Michał; Petruczynik, Anna; Waksmundzka-Hajnos, Monika

    2008-10-17

    There are a lot of taxonomic classifications of the genus Heracleum, and many authors indicate they need revision. Morphological identification is difficult to perform, as there are only few characteristic differences between each Heracleum species, varieties and forms. Furanocoumarins are characteristic compounds for the Apiaceae family, and they can be found in the whole genus in large quantities. Despite this fact, it is difficult to use the furanocoumarin profiles of plants, for their discrimination, as furanocoumarins are difficult to separate, due to their similar chemical structures and physicochemical properties. In this paper, a new, simple method is proposed for the discrimination of selected species, varieties and forms of the genus Heracleum. Thin-layer chromatography (TLC) with an adsorbent gradient (unmodified silica gel+octadecylsilica wettable with water) enables complete separation of the structural analogues. The proposed method gives the possibility to distinguish selected species, varieties and forms of the Heracleum genus, as they produce distinctive furanocoumarin fingerprints. The method is characterised by high specificity, precision, reproducibility and stability values. It is for the first time that graft TLC is used for constructing fingerprints of herbs. The complete separation of ten structural analogues, by combining gradient TLC with the unidimensional multiple development technique, has not been reported yet.

  18. Thin layer chromatography-densitometric determination of some non-sedating antihistamines in combination with pseudoephedrine or acetaminophen in synthetic mixtures and in pharmaceutical formulations.

    Science.gov (United States)

    El-Kommos, Michael E; El-Gizawy, Samia M; Atia, Noha N; Hosny, Noha M

    2014-03-01

    The combination of certain non-sedating antihistamines (NSA) such as fexofenadine (FXD), ketotifen (KET) and loratadine (LOR) with pseudoephedrine (PSE) or acetaminophen (ACE) is widely used in the treatment of allergic rhinitis, conjunctivitis and chronic urticaria. A rapid, simple, selective and precise densitometric method was developed and validated for simultaneous estimation of six synthetic binary mixtures and their pharmaceutical dosage forms. The method employed thin layer chromatography aluminum plates precoated with silica gel G 60 F254 as the stationary phase. The mobile phases chosen for development gave compact bands for the mixtures FXD-PSE (I), KET-PSE (II), LOR-PSE (III), FXD-ACE (IV), KET-ACE (V) and LOR-ACE (VI) [Retardation factor (Rf ) values were (0.20, 0.32), (0.69, 0.34), (0.79, 0.13), (0.36, 0.70), (0.51, 0.30) and (0.76, 0.26), respectively]. Spectrodensitometric scanning integration was performed at 217, 218, 218, 233, 272 and 251 nm for the mixtures I-VI, respectively. The linear regression data for the calibration plots showed an excellent linear relationship. The method was validated for precision, accuracy, robustness and recovery. Limits of detection and quantitation were calculated. Statistical analysis proved that the method is reproducible and selective for the simultaneous estimation of these binary mixtures.

  19. Comparison and characterization of soybean and sunflower lecithins used for chocolate production by high-performance thin-layer chromatography with fluorescence detection and electrospray mass spectrometry.

    Science.gov (United States)

    Krüger, Stephanie; Bürmann, Laura; Morlock, Gertrud E

    2015-03-25

    The scarce availability of nongenetically modified soybeans on the world market represents a growing problem for food manufacturers. Hence, in this study the effects of substituting soybean with sunflower lecithin were investigated with regard to chocolate production. The glycerophospholipid pattern of the different lecithin samples was investigated by high-performance thin-layer chromatography fluorescence detection (HPTLC-FLD) and by HPTLC-positive ion electrospray ionization mass spectrometry (ESI(+)-MS) via the TLC-MS Interface and by scanning HPTLC-matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOFMS). Especially, the contents of phosphatidylcholine (PC) and phosphatidylethanolamine (PE) were of interest due to the influencing effects of these two glycerophospholipids on the rheological parameters of chocolate production. The lecithin substitution led to only slight differences in the rheological parameters of milk and dark chocolate. Limits of detection (LODs) and limits of quantification (LOQs) of seven glycerophospholipids were studied for three detection modes. Mean LODs ranged from 8 to 40 mg/kg for HPTLC-FLD and, using a single-quadrupole MS, from 10 to 280 mg/kg for HPTLC-ESI(+)-MS as well as from 15 to 310 mg/kg for HPTLC-FLD-ESI(+)-MS recorded after derivatization with the primuline reagent.

  20. Validation of an analytical method for the determination of spiramycin, virginiamycin and tylosin in feeding-stuffs by thin-layer chromatography and bio-autography.

    Science.gov (United States)

    Vincent, Ursula; Gizzi, Gisele; von Holst, Christoph; De Jong, Jacob; Michard, Jacques

    2007-04-01

    An inter-laboratory validation was carried out to determine the performance characteristics of an analytical method based on thin-layer chromatography (TLC) coupled to microbiological detection (bio-autography) for screening feed samples for the presence of spiramycin, tylosin and virginiamycin. Twenty-four samples including blank samples and samples with concentrations of the target analytes ranging between 1 and 5 mg kg(-1) (expressed in microbiological activity) were analysed by seven laboratories participating in the study. The required detection limit was 1 mg kg(-1) (expressed in microbiological activity). For spiramycin, acceptable values for the sensitivity (at least 95%) indicating the rate of correct positive results were obtained for samples containing this substance at or above 2 mg kg(-1), whereas at 1 mg kg(-1), the sensitivity rate dropped to about 70%. Therefore, it was concluded that the detection limit was 2 mg kg(-1). For tylosin and virginiamycin, acceptable values of the sensitivity were obtained for all concentrations including 1 mg kg(-1). Therefore, the method fulfils the criterion regarding the required sensitivity at the target detection limit for tylosin and virginiamycin.

  1. Algerian mint species:high performance thin layer chromatography quantitative determination of rosmarinic acid and in vitro inhibitory effects on linoleic acid peroxidation

    Institute of Scientific and Technical Information of China (English)

    Brahmi Fatiha; Madani Khodir; Stvigny Caroline; Chibane Mohamed; Duez Pierre

    2014-01-01

    Objective: To determine the quantitative paremeters of rosmarinic acid in Algerian mints,Mentha spicata L. (M. spicata), Mentha pulegium L. and Mentha rotundifolia (L.) Huds by high performance thin layer chromatography (HPTLC)-densitometric method and screen the effects of these plant extracts on linoleic acid peroxidation.Methods:The analyses were performed on HPTLC silica gel 60 F254 plates with chloroform:acetone: formic acid (75:16.5:8.5, v/v) as the mobile phase. Rosmarinic acid was determined in UV at 365 nm and fluorescence at λexc 325 nm with a 550 nm filter, respectively. The effects of plants extracts on linoleic acid peroxidation were measured by an indirect in vitro colorimetric method.Results:Chromatographic resolution permitted reliable quantification in both measurement modes and calibration curves were linear in a range of 150-1000 ng/spot. M. spicata was found to contain significantly higher concentrations of rosmarinic acid. The densitometric quantification allowed the analysis of many samples in a short time with reasonable precision (total precision for Mentha spp extracts, 5.1% and 5.8% for UV and fluorescence detection, respectively). The HPTLC data, allied to assays of linoleic acid peroxidation prevention, suggested the potential of M. spicata (52% Trolox®equivalents) as a natural source for inhibitors of lipid peroxidation.Conclusions:Densitometry can be used for routine determination and quality control of rosmarinic acid in herbal and formulations containing Mentha species.

  2. Application of thin-layer chromatography with fluorescence scanning densitometry for analysing saturates in heavy liquids derived from co-pyrolysis of biomass and plastics

    Energy Technology Data Exchange (ETDEWEB)

    Cebolla, V.L. [Consejo Superior de Investigaciones Cientificas (CSIC), Instituto de Carboquimica, Zaragoza (Spain); Matt, M. [Institute of Chemistry and Chemical Technology, Krasnoyarsk (Russian Federation). Siberian Branch of Russian Academy of Sciences; Membrado, L. [Universite de Metz, Saint-Avold (FR). Laboratoire de Chimie et Applications] [and others

    2002-01-01

    Two alternative methods, based on Thin-Layer Chromatography (TLC) with Fluorescence Scanning Densitometry have been developed for characterization of heavy liquids from copyrolysis of different kinds of biomass and plastics in autoclaves under inert atmosphere. A conventional TLC system, which includes a vertical developing tank, and a High Performance TLC (HPTLC) system, with a horizontal developing chamber and the use of HPTLC plates, have been used. The analytical method involves in both cases the measurement of two chromatograms per sample: the first, on a silica gel berberine-impregnated plate, for detection of saturates using the phenomenon of berberine-induced fluorescence; and the second, on a silica gel plate, for detection of aromatic-polars and polars, by native fluorescence. Although the HPTLC system is more sensitive and faster, both techniques represent an improvement with regard to current methods for analyzing these kinds of products. However their application depends on the particular solubility of each sample and on its slope of the fluorescent response-sample load regression. (orig.)

  3. Identification and semi-quantitative determination of anti-oxidants in lubricants employing thin-layer chromatography-spray mass spectrometry.

    Science.gov (United States)

    Kreisberger, Georg; Himmelsbach, Markus; Buchberger, Wolfgang; Klampfl, Christian W

    2015-02-27

    A quick and simple method for identification and semi-quantitative determination of nine antioxidants commonly used in lubricants is presented. A dual step thin-layer chromatography (TLC) separation, removes in a first step the oil matrix whereas in a second step the antioxidants are separated. Cutting the spots out of the TLC-plate in the form of triangles allows direct-spray mass spectrometric (MS) measurements, providing MS and MS(n) spectra (if an appropriate MS instrument is employed) of the antioxidants, allowing their identification but also giving information about potential oxidation or degradation of these additives. Calibration curves within the concentration range relevant for the analysis of real oil samples (0.2-1.2gL(-1)) were constructed with R(2) values above 0.98 (when using an appropriate internal standard). This allowed the semi-quantitative determination of the selected antioxidants in real oils samples. Comparison with results from HPLC-UV measurement showed acceptable agreement for all analytes.

  4. Application of 2-Trichloromethylbenzimidazole in Analytical Chemistry: A Highly Selective Chromogenic Reagent for Thin-Layer Chromatography and Some Other Analytical Uses

    Directory of Open Access Journals (Sweden)

    Leszek Konopski

    2012-01-01

    Full Text Available 2-Trichloromethylbenzimidazole (TCMB was used as a chromogenic reagent in organic or inorganic analysis, mainly in thin-layer chromatography (TLC. In reactions of TCMB with some heteroaromatic nitrogen containing compounds, such as azines, azoles and benzazoles, a formation of high colored products occurred. For azines, the chromogenic reaction was highly regioselective, since the both adjacent α-positions versus the nitrogen atom(s must not be substituted. A TLC method of detection was developed. Thirty azines, azoles, and benzazoles were detected at the detection limit 10 ng to 1 μg. This method was also applied for detection of heteroaromatic pesticides, and the attempts to construct active and passive dosimeters for nicotine were made. In a prechromatographic reaction of aromatic o-diamines with methyl trichloroacetimidate, TCMB or its derivatives were formed in situ. Followed by TLC and visualization in pyridine vapors, this procedure was applied for detection of o-phenylenediamine derivatives. The reaction product of TCMB and pyridine (LI Complex was identified and fully characterized. Two different reaction mechanisms: with electron deficient basic heteroaromatic compounds, like pyridine, and with more acidic compounds, for example, pyrrole, were discussed. In aqueous solutions, the LI Complex may be also used as a new indicator for complexometric, adsorption and acid-base titration of inorganic compounds.

  5. Rapid Identification and Comparison of Compounds with Antioxidant Activity in Coreopsis tinctoria Herbal Tea by High-Performance Thin-Layer Chromatography Coupled with DPPH Bioautography and Densitometry.

    Science.gov (United States)

    Lam, Shing-Chung; Lam, Sio-Fong; Zhao, Jing; Li, Shao-Ping

    2016-09-01

    A simple and efficient method based on high-performance thin-layer chromatography coupled with 2,2-diphenyl-1-picrylhydrazyl (DPPH) bioautography (HPTLC-DPPH) was established for the screening and comparison of antioxidants in different parts of Coreopsis tinctoria herbal tea from different origins and other related herbal tea materials, which used Chrysanthemum morifolium cv. "Gongju" and "Hangju" in this study. Scanning densitometry after DPPH derivatization was applied for the determination of antioxidant capacities of isolated compounds in each sample. It is considered that ethanol extracts of C. tinctoria had stronger antioxidant activity and more characteristic bands than those of 2 compared samples, C. morifolium cv. "Gongju" and "Hangju." Chemometric analysis results showed that the combination of hierarchical clustering analysis and principal component analysis based on determined antioxidant capacities could be used for the discrimination of different parts of C. tinctoria and C. morifolium. Results showed that 7 compounds made up the major contributions of antioxidant activity in C. tinctoria, including okanin, isookanin, marein, flavanomarein, 5,7,3',5'-tetrahydroxyflavanone-7-O-glucoside, 3,5-dicaffeoylquinic acid, and chlorogenic acid. Therefore, 7 compounds were identified as major antioxidant biomarkers for quality control of C. tinctoria. Results demonstrated that the established method could be applied for the identification of C. tinctoria, and were beneficial for the bioactivity-based quality control of C. tinctoria.

  6. Simultaneous Analysis of Losartan Potassium, Amlodipine Besylate, and Hydrochlorothiazide in Bulk and in Tablets by High-Performance Thin Layer Chromatography with UV-Absorption Densitometry

    Directory of Open Access Journals (Sweden)

    Karunanidhi Santhana Lakshmi

    2012-01-01

    Full Text Available A Simple high-performance thin layer chromatography (HPTLC method for separation and quantitative analysis of losartan potassium, amlodipine, and hydrochlorothiazide in bulk and in pharmaceutical formulations has been established and validated. After extraction with methanol, sample and standard solutions were applied to silica gel plates and developed with chloroform : methanol : acetone : formic acid 7.5 : 1.3 : 0.5 : 0.03 (/// as mobile phase. Zones were scanned densitometrically at 254 nm. The values of amlodipine besylate, hydrochlorothiazide, and losartan potassium were 0.35, 0.57, and 0.74, respectively. Calibration plots were linear in the ranges 500–3000 ng per spot for losartan potassium, amlodipine and hydrochlorothiazide, the correlation coefficients, r, were 0.998, 0.998, and 0.999, respectively. The suitability of this method for quantitative determination of these compounds was by validation in accordance with the requirements of pharmaceutical regulatory standards. The method can be used for routine analysis of these drugs in bulk and in formulation.

  7. Determination of Four Major Saponins in Skin and Endosperm of Seeds of Horse Chestnut (Aesculus Hippocastanum L.) Using High Performance Liquid Chromatography with Positive Confirmation by Thin Layer Chromatography

    Science.gov (United States)

    Abudayeh, Zead Helmi Mahmoud; Al Azzam, Khaldun Mohammad; Naddaf, Ahmad; Karpiuk, Uliana Vladimirovna; Kislichenko, Viktoria Sergeevna

    2015-01-01

    Purpose: To separate and quantify four major saponins in the extracts of the skin and the endosperm of seeds of horse chestnut (Aesculus hippocastanum L.) using ultrasonic solvent extraction followed by a high performance liquid chromatography-diode array detector (HPLC-DAD) with positive confirmation by thin layer chromatography (TLC). Methods: The saponins: escin Ia, escin Ib, isoescin Ia and isoescin Ib were extracted using ultrasonic extraction method. The optimized extraction conditions were: 70% methanol as extraction solvent, 80 °C as extraction temperature, and the extraction time was achieved in 4 hours. The HPLC conditions used: Zorbax SB-ODS-(150 mm × 2.1 mm, 3 μm) column, acetonitrile and 0.10% phosphoric acid solution (39:61 v/v) as mobile phase, flow rate was 0.5 mL min−1 at 210 nm and 230 nm detection. The injection volume was 10 μL, and the separation was carried out isothermally at 30 °C in a heated chamber. Results: The results indicated that the developed HPLC method is simple, sensitive and reliable. Moreover, the content of escins in seeds decreased by more than 30% in endosperm and by more than 40% in skin upon storage for two years. Conclusion: This assay can be readily utilized as a quality control method for horse chestnut and other related medicinal plants. PMID:26819933

  8. Linear modeling of the soil-water partition coefficient normalized to organic carbon content by reversed-phase thin-layer chromatography.

    Science.gov (United States)

    Andrić, Filip; Šegan, Sandra; Dramićanin, Aleksandra; Majstorović, Helena; Milojković-Opsenica, Dušanka

    2016-08-05

    Soil-water partition coefficient normalized to the organic carbon content (KOC) is one of the crucial properties influencing the fate of organic compounds in the environment. Chromatographic methods are well established alternative for direct sorption techniques used for KOC determination. The present work proposes reversed-phase thin-layer chromatography (RP-TLC) as a simpler, yet equally accurate method as officially recommended HPLC technique. Several TLC systems were studied including octadecyl-(RP18) and cyano-(CN) modified silica layers in combination with methanol-water and acetonitrile-water mixtures as mobile phases. In total 50 compounds of different molecular shape, size, and various ability to establish specific interactions were selected (phenols, beznodiazepines, triazine herbicides, and polyaromatic hydrocarbons). Calibration set of 29 compounds with known logKOC values determined by sorption experiments was used to build simple univariate calibrations, Principal Component Regression (PCR) and Partial Least Squares (PLS) models between logKOC and TLC retention parameters. Models exhibit good statistical performance, indicating that CN-layers contribute better to logKOC modeling than RP18-silica. The most promising TLC methods, officially recommended HPLC method, and four in silico estimation approaches have been compared by non-parametric Sum of Ranking Differences approach (SRD). The best estimations of logKOC values were achieved by simple univariate calibration of TLC retention data involving CN-silica layers and moderate content of methanol (40-50%v/v). They were ranked far well compared to the officially recommended HPLC method which was ranked in the middle. The worst estimates have been obtained from in silico computations based on octanol-water partition coefficient. Linear Solvation Energy Relationship study revealed that increased polarity of CN-layers over RP18 in combination with methanol-water mixtures is the key to better modeling of

  9. Development and Validation of High Performance Thin-Layer Chromatography and Derivative Spectrophotometry methods for determination of Diazepam and Propranolol Hydrochloride in Combined Dosage Form

    Directory of Open Access Journals (Sweden)

    Bhadani Shweta

    2013-03-01

    Full Text Available The manuscript describes validated high performance thin layer chromatography (HPTLC and first derivative UV spectrophotometric methods for the estimation of diazepam (DZP and propranolol hydrochloride (PRO in combined dosage form. The HPTLC separation was achieved on an aluminium-backed layer of silica gel 60F254 using mobile phase ethylacetate-methanol-toluene-triethylamine (1.0 + 3.0 + 6.0 + 0.1, v/v/v/v. Quantification was achieved with UV detection at 235 nm over the concentration range 25 – 250 ng/spot and 200 – 2000 ng/spot for DZP and PRO respectively, with mean recovery of 100.3 ± 0.54 and 100.2 ± 0.35 % for DZP and PRO, respectively by HPTLC method. Derivative spectrophotometric method was based on the estimation of both the drugs at their respective zero crossing point (ZCP. The first-order derivative spectra were obtained at N = 1 (scaling factor, Δλ = 2.0 nm, and the determinations were made at 248 nm (ZCP of PRO for DZP and 242 nm (ZCP of DZP for PRO over the concentration range of 2.5–30 μg/mL for both DZP and PRO with mean recovery of 100.2 ± 0.49 and 100.1 ± 0.13 % for DZP and PRO, respectively by first derivative UV spectrophotometric method. These methods were found to be simple, sensitive, accurate, precise, reproducible and economical and applicable for the simultaneous determination of DZP and PRO in combined dosage form.

  10. High performance thin layer chromatography (HPTLC) and high performance liquid chromatography (HPLC) for the qualitative and quantitative analysis of Calendula officinalis-advantages and limitations.

    Science.gov (United States)

    Loescher, Christine M; Morton, David W; Razic, Slavica; Agatonovic-Kustrin, Snezana

    2014-09-01

    Chromatography techniques such as HPTLC and HPLC are commonly used to produce a chemical fingerprint of a plant to allow identification and quantify the main constituents within the plant. The aims of this study were to compare HPTLC and HPLC, for qualitative and quantitative analysis of the major constituents of Calendula officinalis and to investigate the effect of different extraction techniques on the C. officinalis extract composition from different parts of the plant. The results found HPTLC to be effective for qualitative analysis, however, HPLC was found to be more accurate for quantitative analysis. A combination of the two methods may be useful in a quality control setting as it would allow rapid qualitative analysis of herbal material while maintaining accurate quantification of extract composition.

  11. Anti-inflammatory activity and qualitative analysis of different extracts of Maytenus obscura (A. Rich.) Cuf. by high performance thin layer chromatography method

    Institute of Scientific and Technical Information of China (English)

    Mohamed F. Alajmi; Perwez Alam

    2014-01-01

    Objective: To perform aqueous ethanol soluble fraction (AESF) and dichloromethane extract of aerial parts of Maytenus obscura (A. Rich.) Cuf. using high performance thin layer chromatography (HPTLC) and to test anti-inflammatory activity of these extracts.Methods:HPTLC studies were carried out using CAMAG HPTLC system equipped with Linomat IV applicator, TLC scanner 3, Reprostar 3, CAMAG ADC 2 and WIN CATS-4 software were used. The anti-inflammatory activity was tested by injecting different groups of rats (6 each) with formalin in hind paw and measuring the edema volume before and 1 h later formalin injection. Control group received saline i.p. The extracts treatment was injected i.p. in doses of 100 and 200 mg/kg 1 h before formalin administration. Indomethacin (30 mg/kg) was used as standard.Results:The results of preliminary phytochemical studies confirmed the presence of protein, lipid, carbohydrate, phenol, flavonoid, saponin, triterpenoid, alkaloid and anthraquinone in both extracts. Chromatography was performed on glass-backed silica gel 60 F254 HPTLC plates with the green solvents toluene: ethyacetate: glacial acetic acid (5:3:0.2, v/v/v) as mobile phase. HPTLC finger printing of AESF revealed major eight peaks with Rf values in the range of 0.28 to 0.80 and the dichloromethane revealed major 11 peaks with Rf values in the range of 0.12 to 0.76. The purity of sample was confirmed by comparing the absorption spectra at start, middle and end position of the band. Treatment of rats (i.p.) with AESF and dichloromethane in doses of 100 and 200 mg/kg inhibited singnificantly (P<0.05, n=6) formalin-induced inflammation by 50%, 55.9%, 45.5%, and 51.4%, respectively.Conclusions:HPTLC finger printing of AESF and dichloromethane of Maytenus obscura revealed eight major spots for alcoholic extracts and nine major spots for dichloromethane extracts. These HPTLC profiles may be of great usefulness in the quality control of herbal products containing these extracts. The

  12. Identity-based High-performance thin Layer Chromatography Fingerprinting Profile and Tumor Inhibitory Potential of Anisochilus carnosus (L.f.) wall Against Ehrlich Ascites Carcinoma

    Science.gov (United States)

    Gupta, Nilesh; Lobo, Richard; Kumar, Nimmy; Bhagat, Jay Kumar; Mathew, Jessy Elizabeth

    2015-01-01

    Context: Anisochilus carnosus (L.f.) wall belonging to the family Lamiaceae is a plant that is widely used in folk medicine for treating eczema, cold, cough, and fever. Objective: In the present study, we explored the anticancer potential of A. carnosus leaves against Ehrlich ascites carcinoma (EAC) and estimated the quantity of luteolin present in various extracts and fractions of A. carnosus by high-performance thin layer chromatography (HPTLC) fingerprinting. Materials and Methods: Various factors such as tumor volume, tumor cell viability, tumor weight, prolongation of lifespan, and hematological parameters were assessed. Result: We observed a significant lowering in tumor volume, tumor weight, and cell viability in EAC-induced mice following intervention with A. carnosus extracts. Also, there was a considerable prolongation of host lifespan and restoration of hematological parameters to almost normal levels with A. carnosus treatment. HPTLC fingerprinting of various extracts and fractions of A. carnosus along with luteolin as the reference standard revealed the occurrence of luteolin in all tested extracts and fractions of A. carnosus with the highest concentration being reported in the ethanol fraction. Conclusion: A. carnosus exhibits potent anti-tumor potential which can most likely be attributed to the occurrence of different phytochemicals such as phytosterols, terpenoids, and flavonoids in the plant. Further studies to isolate compounds from A. carnosus and understand the mechanism of anti-tumor activity would be worthwhile. SUMMARY EAC induced mice that received A. carnosus treatment exhibited significant reduction in tumor volume, tumor weight and tumor cell viability. Their life span was considerably prolonged. We detected luteolin in A. carnosus aqueous and ethanol extract using HPTLC. Hence, anticancer activity of A. carnosus can be partly attributed to the presence of luteolin. PMID:26929584

  13. Detection and quantification of quinolone signalling molecule: a third quorum sensing molecule of Pseudomonas aeruginosa by high performance-thin layer chromatography.

    Science.gov (United States)

    Bala, Anju; Gupta, Ravi Kumar; Chhibber, Sanjay; Harjai, Kusum

    2013-07-01

    Sophisticated network of quorum sensing involves the production of chemical signals which regulate the combined expression of virulence genes and biofilm formation in Pseudomonas aeruginosa. Two well-characterized acyl homoserine lactone based las and rhl systems together with alkyl quinolone based Pseudomonas quinolone signalling (PQS) are fundamental components of this network. Third signalling molecule, 2-heptyl-3-hydroxy-4-quinolone (PQS) is of paramount importance because of its interconnecting role in quorum sensing hierarchy in P. aeruginosa. Accurate detection of PQS molecule is very important to understand the involvement of this system in infection process of P. aeruginosa. In this study, high performance-thin layer chromatography (HP-TLC) method was developed for detection as well as quantification of PQS signal molecules in P. aeruginosa, which combines conventional method like TLC with sophisticated instrumentation. This method was validated using parameters like linearity, accuracy, precision, reproducibility and sensitivity. Intra- and inter-day accuracy and precision values were determined which were found to be within acceptable level and hence showed reproducibility. Measurement of PQS in the range of 0.01nmol indicated excellent sensitivity of this approach for quantifying PQS molecule. Automated sampling, rapid and simultaneous analysis of large number of samples and minimal errors make this method more suitable for analysis of PQS signalling molecules. Production of PQS was found to be strain dependent since variation in amount of PQS was observed among different P. aeruginosa isolates. Further, PQS production was also dependent on growth phase of P. aeruginosa with maximum production in late stationary phase.

  14. Children better powder identified by thin layer chromatography%小儿吐泻宁散剂薄层层析鉴别

    Institute of Scientific and Technical Information of China (English)

    刘秋伟; 姜亚玲; 李占灵

    2016-01-01

    小儿吐泻宁散剂作为芳香化湿药,主要含广藿香、甘草、厚朴、陈皮、半夏等药材。实验通过薄层层析色谱法来鉴别这五种药材的有效成分进而来鉴别小儿吐泻宁散剂。通过制备五种药物主要成分的供试液、阴性、阳性对照液,在经过严格的薄层色谱鉴别后绘制了完善的色谱图。通过直观的色谱图观察,得到了满意的实验结果。成功地鉴别了小儿吐泻宁散剂中的五种主药。%As aromatization wet medicine mainly containing patchouli,liquorice,magnolia bark and herbs such as dried tangerine or orange peel.This experiment made by thin layer chromatography to identify the active ingredients of the me-dicinal materials to identify four children in children better dispersing agent.By making four drugs main composition of the fluid,feminine positive control under test,and the purchase of four main components:the autumn lee alcohol,ammonium glycyrrhetatehonokiol,Beta sitosterol.After strict TLC was used to prepare the perfect chromatogram.Through intuitive chromatogram observation,the satisfactory experimental results were obtained,and successfully identify the pediatric chil-dren better dispersing agent`s five ingredients.

  15. Direct analysis of Salvia divinorum leaves for salvinorin A by thin layer chromatography and desorption electrospray ionization multi-stage tandem mass spectrometry.

    Science.gov (United States)

    Kennedy, Joseph H; Wiseman, Justin M

    2010-05-15

    Salvia divinorum is widely cultivated in the US, Mexico, Central and South America and Europe and is consumed for its ability to produce hallucinogenic effects similar to those of other scheduled hallucinogenic drugs, such as LSD. Salvinorin A (SA), a kappa opiod receptor agonist and psychoactive constituent, is found primarily in the leaves and to a lesser extent in the stems of the plant. Herein, the analysis of intact S. divinorum leaves for SA and of acetone extracts separated using thin layer chromatography (TLC) is demonstrated using desorption electrospray ionization (DESI) mass spectrometry. The detection of SA using DESI in the positive ion mode is characterized by several ions associated with the compound - [M+H](+), [M+NH(4)](+), [M+Na](+), [2M+NH(4)](+), and [2M+Na](+). Confirmation of the identity of these ions is provided through exact mass measurements using a time-of-flight (ToF) mass spectrometer. The presence of SA in the leaves was confirmed by multi-stage tandem mass spectrometry (MS(n)) of the [M+H](+) ion using a linear ion trap mass spectrometer. Direct analysis of the leaves revealed several species of salvinorin in addition to SA as confirmed by MS(n), including salvinorin B, C, D/E, and divinatorin B. Further, the results from DESI imaging of a TLC separation of a commercial leaf extract and an acetone extract of S. divinorum leaves were in concordance with the TLC/DESI-MS results of an authentic salvinorin A standard. The present study provides an example of both the direct analysis of intact plant materials for screening illicit substances and the coupling of TLC and DESI-MS as a simple method for the examination of natural products.

  16. Identification of Ginkgo biloba supplements adulteration using high performance thin layer chromatography and ultra high performance liquid chromatography-diode array detector-quadrupole time of flight-mass spectrometry.

    Science.gov (United States)

    Avula, Bharathi; Sagi, Satyanarayanaraju; Gafner, Stefan; Upton, Roy; Wang, Yan-Hong; Wang, Mei; Khan, Ikhlas A

    2015-10-01

    Ginkgo biloba is one of the most widely sold herbal supplements and medicines in the world. Its popularity stems from having a positive effect on memory and the circulatory system in clinical studies. As ginkgo popularity increased, non-proprietary extracts were introduced claiming to have a similar phytochemical profile as the clinically tested extracts. The standardized commercial extracts of G. biloba leaf used in ginkgo supplements contain not less than 6% sesquiterpene lactones and 24% flavonol glycosides. While sesquiterpene lactones are unique constituents of ginkgo leaf, the flavonol glycosides are found in many other botanical extracts. Being a high value botanical, low quality ginkgo extracts may be subjected to adulteration with flavonoids to meet the requirement of 24% flavonol glycosides. Chemical analysis by ultra high performance liquid chromatography-mass spectrometry revealed that adulteration of ginkgo leaf extracts in many of these products is common, the naturally flavonol glycoside-rich extract being spiked with pure flavonoids or extracts made from another flavonoid-rich material, such as the fruit/flower of Japanese sophora (Styphnolobium japonicum), which also contains the isoflavone genistein. Recently, genistein has been proposed as an analytical marker for the detection of adulteration of ginkgo extracts with S. japonicum. This study confirms that botanically authenticated G. biloba leaf and extracts made therefrom do not contain genistein, and the presence of which even in trace amounts is suggestive of adulteration. In addition to the mass spectrometric approach, a high performance thin layer chromatography method was developed as a fast and economic method for chemical fingerprint analysis of ginkgo samples.

  17. Correlation between ultra-high performance liquid chromatography-tandem mass spectrometry and reversed-phase thin-layer chromatography hydrophobicity data for evaluation of angiotensin-converting enzyme inhibitors absorption.

    Science.gov (United States)

    Odovic, Jadranka V; Markovic, Bojan D; Injac, Rade D; Vladimirov, Sote M; Karljikovic-Rajic, Katarina D

    2012-10-05

    In this research seven ACE inhibitors (enalapril, quinapril, fosinopril, lisinopril, cilazapril, ramipril, benazepril) were studied to evaluate the correlation between their absorption and ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS) and reversed-phase thin-layer chromatography (RP-TLC) hydrophobicity data (φ(0) or C(0) parameters, respectively). Their absorption values were in the range of 25-60%, while calculated KOWWIN logP values were from -0.94 to 6.61. Additionally, perindopril (absorption 70%, KOWWIN logP 2.59) and moexipril (absorption 22%, KOWWIN logP 3.36) were introduced for the theoretical considerations due to their high/low absorption values which were on the opposite sites in comparison with the majority of ACE inhibitors (25-60%). In the theoretical considerations it was shown that the solubility data (logS) must be considered, as independent variable, simultaneously with KOWWIN logP to obtain reliable correlation (r(2)=0.7208) between absorption and ACE inhibitors lipophilicity. As the main topic of this study, the relationships between literature available and absorption data predicted by multiple linear regression (MLR) using logS values besides chromatographically obtained hydrophobicity parameters C(0) (r(2)=0.6424) or φ(0) (r(2)=0.6762) were studied proving that these parameters could be used in ACE inhibitors absorption evaluation. The UHPLC-MS method provides the direct application of experimentally obtained φ(0) values that is the advantage of this method. For better MLR correlation of ACE inhibitors absorption with C(0) parameters (RP-TLC) and logS, mathematical conversion of C(0) parameters to logC(0) values was necessary based on requisite for probability value of regression analysis (P<0.05). The accordance and differences between hydrophobicity parameters obtained by UHPLC-MS and RP-TLC were defined.

  18. Thin-layer chromatography/direct analysis in real time time-of-flight mass spectrometry and isotope dilution to analyze organophosphorus insecticides in fatty foods.

    Science.gov (United States)

    Kiguchi, Osamu; Oka, Kazuko; Tamada, Masafumi; Kobayashi, Takashi; Onodera, Jun

    2014-11-28

    To assess food safety emergencies caused by highly hazardous chemical-tainted foods, simultaneous analysis of organophosphorus insecticides in fatty foods such as precooked foods was conducted using thin-layer chromatography/direct analysis in real time time-of-flight mass spectrometry (TLC/DART-TOFMS) and isotope dilution technique. Polar (methamidophos and acephate) and nonpolar organophosphorus insecticides (fenitrothion, diazinon, and EPN) were studied. Experiments to ascertain chromatographic patterns using TLC/DART-TOFMS reveal that it was more useful than GC/MS or GC/MS/MS for the simultaneous analyses of polar and nonpolar pesticides, while obviating the addition of a protective agent for tailing effects of polar pesticides. Lower helium gas temperature (260°C) for DART-TOFMS was suitable for the simultaneous analysis of target pesticides. Linearities were achieved respectively at a lower standard concentration range (0.05-5 μg) for diazinon and EPN and at a higher standard concentration range (2.5-25 μg) for methamidophos, acephate, and fenitrothion. Their respective coefficients of determination were ≥ 0.9989 and ≥ 0.9959. A few higher repeatabilities (RSDs) for diazinon and EPN were found (>20%), although isotope dilution technique was used. Application to the HPTLC plate without an automatic TLC sampler might be inferred as a cause of their higher RSDs. Detection limits were estimated in the higher picogram range for diazinon and EPN, and in the lower nanogram range for methamidophos, acephate, and fenitrothion. Aside from methamidophos, recovery results (n=3) obtained using a highly insecticide-tainted fatty food (dumpling) and raw food (grapefruit) samples (10mg/kg) using TLC/DART-TOFMS with both complex and simpler cleanups were not as susceptible to matrix effects (95-121%; RSD, 1.3-14%) as those using GC/MS/MS (102-117%; RSD, 0.4-8.5%), although dumpling samples using GC/MS were remarkably susceptible to matrix effects. The coupled method of

  19. Study on Corydalis Yanhusuo Rhubarb Curcuma and Dragon's Blood in Pain -Restraining Medicinal Membrane by Thin -layer Chromatography%克痛药膜中元胡大黄姜黄血竭的薄层色谱研究

    Institute of Scientific and Technical Information of China (English)

    谢浩洋; 丁关生

    2012-01-01

    目的:研究克痛药膜中的元胡、血竭、姜黄、大黄4味中药的薄层色谱.方法:采用薄层色谱法,在硅胶G薄层板上,以环己烷-丙酮(8∶2)为展开剂,鉴别元胡;以石油醚( 60 ~ 90℃) -乙醚(3∶2)为展开剂,鉴别大黄;以三氯甲烷-甲醇-甲酸(96∶4∶0.7)为展开剂为展开剂,鉴别姜黄;以三氯甲烷-甲醇(19∶1)为展开剂,鉴别血竭.结果:依据正文所述方法,薄层展开后,色谱斑点显色清晰,分离效果好,与对照药材显色一致.结论:依据正文所述方法,针对元胡、血竭、姜黄、大黄4味中药,其薄层色谱图的检出成分消除了其它成分的干扰,专属性强,重现性好,方法简便,可以作为该制剂质量控制的检测标准.%Objective: To research corydalis yanhusuo,rhubarb,curcuma and dragons blood in pain - restraining medici-nal membrane by thin - layer chromatography. Methods: Adopting the thin - layer chromatography, on the thin layer of the silicon G, identified corydalis yanhusuo using cyclohexane - acetone (8 : 2 ) as the developing agent; identified rhubarb using petroleum ether(60 ~90℃ ) -aether(3 : 2)as the developing agent;identified curcuma using chloroform -methanol -meth-anoic acid(96 :4 : 0.7) as the developing agent; identified dragons blood using chlorqform -methanol (19 : l)as the develo-ping agent. Results :According to the related method,after the thin layer expanded,every main fleck was clearly colored, well disparted and have the same color with the respective contrast medicinal materialss main flecks. Conclusions: Accord-ing to the related method,the thin - layer chromatography clearly showed the component of corydalis yanhusuo,rhubarb,cur-cuma and dragons blood which were distinctly detected without the interference of other elements. The related method was specific, repeatable, simple, and could be taken as the standard to control the quality of this preparation.

  20. Determinação de fármacos diuréticos em associação por cromatografia em camada delgada e espectrofotometria Determination of diuretic drugs by thin layer chromatography and spectrophotometry

    Directory of Open Access Journals (Sweden)

    Dênia Mendes de Sousa Valladão

    2008-01-01

    Full Text Available A rapid, sensitive and reliable thin-layer chromatography/spectrophotometry screening procedure was developed for quantitative determination of diuretics associated in pharmaceutical dosage forms. The chromatographic method employed microcrystalline cellulose and butanol : acetic acid : water (4:1:1 or amilic alcohol : ammonium hydroxide 25% (9:1 as mobile phases and detection by U.V. light. The drugs were extracted using a simple procedure and were quantified by U.V. spectrophotometry. Results varied from 97.5 to 102.5% and are similar to those obtained by conventional methods. This method of quantification of diuretics is promising for quality control of drugs.

  1. 火炭母药材薄层鉴别方法的研究%Study on Identification Methods of the Polygonum Chinensis L. of Thin-layer Chromatography

    Institute of Scientific and Technical Information of China (English)

    程建国; 侯丽丽; 晏永新

    2015-01-01

    Polygonum chinensis L. had been recorded in chinese veterinary pharmacopoeia (second part, 2010 edition), the current standard contains microscopic, physical and chemical method.According to the requirements of standards, drug quality standard should be controlled main ingredients or active ingredients.Now study on i-dentification methods of the polygonum chinensis L. of thin-layer chromatography, and made identification meth-ods of the polygonum chinensis L. of thin-layer chromatography.%火炭母药材现收载《中华人民共和国兽药典》2010版二部,现行标准只有显微、理化等鉴别方法,按标准制修订要求,方法应控制主要成分或有效成分,现对火炭母药材进行了薄层鉴别方法研究,并制定了薄层鉴别方法.

  2. Determination of furanochromones and pyranocoumarins in drugs and Ammi visnaga fruits by combined solid-phase extraction-high-performance liquid chromatography and thin-layer chromatography-high-performance liquid chromatography.

    Science.gov (United States)

    Zgórka, G; Dragan, T; Głowniak, K; Basiura, E

    1998-02-27

    A new, simple and rapid solid-phase extraction method for the determination of furanochromones and pyranocoumarins in Ammi visnaga L. fruits and pharmaceuticals by reversed-phase high-performance liquid chromatography (RP-HPLC) was developed. The isolation of compounds examined was carried out on octadecyl BakerBond SPE columns using various concentrations of methanol, acetonitrile and tetrahydrofuran in water. High and reproducible recoveries were obtained. To compare the results of quantitative analysis a preparative TLC procedure was also elaborated and carried out.

  3. Gold nanoparticles grafted modified silica gel as a new stationary phase for separation and determination of steroid hormones by thin layer chromatography

    Directory of Open Access Journals (Sweden)

    Mitra Amoli-Diva

    2015-06-01

    Full Text Available A new thin layer chromatographic layer using gold nanoparticles grafted 3-triethoxysilyl propylamine modified silica gel (Au NPs-APTS modified silica gel was developed as a stationary phase for separation and determination of two steroid hormones, namely progesterone and testosterone. Acetone–n-hexane 25:75 (v/v was used as the mobile phase, and the results were compared with those obtained using plain (i.e., unmodified silica gel plates. Some chromatographic parameters used for separation of the two steroids on an Au NPs-APTS modified silica gel plate as well as on a plain silica gel plate, including ΔRF, separation factor (α, and resolution (RS, were evaluated and compared. The reproducibility of RF values was also determined by analysis of the two steroids in 7 consecutive days on both plates. Validity of the method was investigated, and a wide linear range of 1–200 ng per spot, and low detection limits of 0.16 ng and 0.13 ng per spot, low quantification limits of 0.51 ng and 0.40 ng per spot, and good precision (expressed as percent relative standard deviation lower than 3.1% and 2.7% were obtained for progesterone and testosterone, respectively. As the results revealed, the proposed method is rapid and sensitive, and it is applicable to separation and determination of progesterone and testosterone in biological matrices such as urine samples.

  4. 薄层色谱法检测海州常山桐树叶中肾上腺素的含量%Identification and quantification of adrenaline from the leaves of Clerodendrum phlomidis using thin-layer chromatography

    Institute of Scientific and Technical Information of China (English)

    Muthu Kumaradoss Mohan Maruga Raja; Ruchi Sureshbhai Patel; Shri Hari Mishra

    2011-01-01

    @@ In the Ayurvedic, Siddha and other medical systems of India, products derived from herbs,used either as active ingredients or as adjuvants,hold paramount importance as alternative medi-cines.However, their standardization poses a great challenge.Correct identification of these drugs is often problematic in both their complete form as well as in powder form, since these medicinal plants are known by a variety of vernacular names and frequently many medicinal plants share the same name.Comparative thin-layer chromatography (co-TLC) with chemical or biological marker compounds can be used to standardize raw materials.Moreover, due to its simplicity, accuracy, cost effectiveness and rapidity, TLC is often used as an alternative to other chromatographic tech-niques for quantifying plant products.

  5. Effects of Different Levels of Echinostoma caproni Miracidial Dose on Glucose and Maltose Composition of Biomphalaria glabrata Snails as Determined by High Performance Thin-Layer Chromatography-Densitometry

    Directory of Open Access Journals (Sweden)

    Dolcie DeGrandchamp

    2015-04-01

    Full Text Available The effects of 5, 25, and 40 Echinostoma caproni miracidia on the sugar content of young adult and mature adult Biomphalaria glabrata were studied using high performance thin layer chromatography (HPTLC-densitometry. Analysis was done on the snail’s digestive gland gonad complex (DGG at two and four weeks postmiracidial exposure. The sugars were extracted from the DGG using 70% ethanol and analyzed on silica gel HPTLC plates with a preadsorbent zone using 1-butanol-glacial acetic acid-diethyl ether-deionized water (27:18:5:3 mobile phase. The separated bands were then detected using alpha-naphthol-sulfuric reagent and quantified by densitometry at 515 nm. Significant differences were found in the maltose content between two and four weeks post exposure for both age groups. Additionally, significantly lower maltose and glucose levels were observed in the high exposure groups of both ages.

  6. Determination of alpha-solanine and alpha-chaconine in potatoes by high-performance thin-layer chromatography/densitometry.

    Science.gov (United States)

    Bodart, P; Kabengera, C; Noirfalise, A; Hubert, P; Angenot, L

    2000-01-01

    A high-performance thin-layer chromatographic (HPTLC) method was used to determine the glycoalkaloids alpha-solanine and alpha-chaconine in potatoes. Alpha-solanine and alpha-chaconine are extracted from dehydrated potatoes with boiling methanol-acetic acid (95 + 5, v/v). The analytes are separated on a Silica Gel 60 F254 HPTLC plate by a saturated mixture of dichloromethane-methanol-water-concentrated ammonium hydroxide (70 + 30 + 4 + 0.4, v/v), which is used for vertical development of the plate up to a distance of 85 mm. For visualization, the plate is dipped 3 times into a modified Carr-Price reagent, 20% (w/v) antimony(III) chloride in acetic acid-dichloromethane (1 + 3, v/v), and subsequently heated on a hot plate at 105 degrees C for 5 min. The glycoalkaloids all appear as red chromatographic zones on a colorless background. Densitometric quantification is performed at 507 nm by reflectance scanning. After determination of the appropriate response function, the proposed method was validated. Good results with respect to linearity, accuracy, and precision were obtained in the concentration range studied.

  7. Thin-layer chromatography of total alkaloids in Croton tiglium%巴豆生物碱的薄层色谱鉴别研究

    Institute of Scientific and Technical Information of China (English)

    李晓伟; 易智彪; 曾宝; 李生梅; 唐君苹; 袁捷

    2013-01-01

    Objective:To establish a thin layer chromatographic(TLC) method for the Croton alkaloids,and to offer evidence for quality evaluation of Fructus Crotonis. Methods: The determination was done by using TLC. With isoguanosine and magnoflorine as reference, water (6∶4∶1,5 drops of ammonia) as the develop system was established. After launching and took out air driesand developed with iodine vapor. Results: A same color spots in the TLC graph of sample existed at the corresponding positions compared with the controls. Conclusions: The established method is simple and accurate,and have a good repeatability,which will supply evidence for the quality evaluation of medicinal material of Fructus Crotonis.%  目的:建立巴豆生物碱的薄层鉴别方法,为巴豆药材的质量评价提供依据。方法:采用 TLC 法,以巴豆苷和木兰花碱为对照品,以氯仿-甲醇-水(6∶4∶1,加5滴氨水)为展开系统,碘熏显色。结果:在日光下检视,在两组对照品相应位置上,显出相同颜色的斑点。结论:该方法简便、准确、重现性好,为评价巴豆药材定性鉴别及内在质量提供了科学依据。

  8. Use of thin layer chromatography for the determination of radiochemical purity of radiopharmaceuticals in nuclear medicine services of Paraiba and Rio Grande do Norte, Brazil; Utilizacao da cromatografia em camada delgada para determinacao da pureza radioquimica de radiofarmacos em servicos de medicina nuclear da Paraiba e Rio Grande do Norte, Brasil

    Energy Technology Data Exchange (ETDEWEB)

    Andrade, W.G.; Santos, P.A.L.; Lima, F.R.A. [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Programa de Pos-Graduacao em Tecnologia Energetica; Lima, F.F., E-mail: wellington.gandrade@gmail.com [Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (Brazil)

    2012-07-01

    The paper chromatography and the thin layer chromatography are separation techniques in which the radioactive components migrate because of their affinity with the eluent (mobile phase) or stationary phase, respectively. In radiopharmaceuticals labeled with {sup 99m}Tc, besides its own radiopharmaceutical, {sup 99m}TcO{sup 4-} free and TcO{sub 2} can be identified and quantified. The evaluation of radiochemical purity of radiopharmaceuticals is essential to produce images free of artifacts as well as avoid unnecessary absorbed dose to the patient. Once they are managed in humans it is important and necessary that they undergo to strict quality control. Because of this, ANVISA in its 'Resolucao da Diretoria Colegiada (RDC) 38 of June 4th, 2008 states the obligation of performing a minimum of tests in nuclear medicine services routine prior to human administration. This work evaluated, by the method of thin layer chromatography (TLC), radiochemical purity, determined the pH of the radiopharmaceutical DEXTRAN- 500, DMSA, DTPA, PHYTATE, MDP, MIBI and Sn-Col used in nuclear medicine services in the states of Paraiba and Rio Grande do Norte - Brazil. The results show that the use of thin layer chromatography (TLC) as a standard method in routine of nuclear medicine services is possible, because it provides important data for the evaluation of radiochemical purity, allowing the exclusion of a radiopharmaceutical poorly marked. (author)

  9. Correct assignment of lipophilic dye mixtures? A case study for high-performance thin-layer chromatography-mass spectrometry and performance data for the TLC-MS Interface.

    Science.gov (United States)

    Morlock, Gertrud E; Brett, Neil

    2015-04-17

    The TLC-MS Interface, the successor of the ChromeXtract, has been available for elution head-based coupling of high-performance thin-layer chromatography with mass spectrometry (HPTLC-MS) since 2009, and is meanwhile widespread in use, mainly for compound confirmation. Until now, quantitative performance data has not been reported in detail and thus were investigated in this study. The performance data of HPTLC-electrospray ionization (ESI)-MS via the TLC-MS Interface showed good mean precisions (%RSD, n=5) for 6 dyes in a commercially available dye mixture investigated at two different concentrations (7.3% for the 1:8 dilution, and 10.1% for the 1:16 diluted) in a selected worst case scenario. The respective mean precisions of absorbance measurements were ≤1.3%. For calibrations by HPTLC-ESI-MS, the mean determination coefficient was 0.9975 for the 6 dyes (versus 0.9997 for absorbance measurement). HPTLC-MS analysis revealed the incorrect assignment of components in two commercially available dye mixtures. Using an additional software (MassWorks) that delivered a 100 times increased mass accuracy, the proposal of molecular formulae was shown to be obtainable under certain conditions with a low resolution single quadrupole mass spectrometer and in the case of helpful information such as the double bond equivalents. This enabled the identification of the incorrectly assigned unknown dyes and clearly demonstrated the benefit of using HPTLC-MS for zone confirmation.

  10. A rapid, micro-scale preliminary screening method for active components in Galangal with protective effect against hydrogen peroxide induced cell apoptosis through "thin layer chromatography" and "tetrazolium-based colorimetric assay" array correspondence.

    Science.gov (United States)

    Cheng, Yuan; Li, Yuanting; Li, Jin; Deng, Yifeng

    2015-05-22

    A new method has been established for rapid preliminary screening active ingredients in natural products through thin layer chromatography (TLC) array responding with tetrazolium-based colorimetric assay (MTT assay) along with post LC-MS in micro-scale. The extract of the natural product was first separated by TLC. The separated spots obtained from TLC were visualized in situ with vanillin-ethanolic sulfuric acid agent to define the array correspondence between TLC spots and 384-cell culture plate for MTT cell viability assay. The TLC spots from the replicate TLC plates were then eluted and transferred into the wells of 384-cell culture plates according to the array respondence. The TLC spots with significant antioxidant activities were further screened by MTT assay, and subsequently traced and identified by LC-MS based on the TLC-MTT assay array correspondence. This new method was successfully applied to screen active ingredients in a Chinese medicine known as Galangal. Two major inhibitors for the decline of PC12 cell survival (Galangin, m/z 269.1, and 5-hydroxy-7-(4'-hydroxy-3'-methoxyphenyl)-1-phenyl-3-heptanone, m/z 327.2) were effectively screened and identified by this method.

  11. Cromatografia em camada delgada para o diagnóstico da intoxicação por aldicarb ("chumbinho" em cães e gatos Thin-layer chromatography for aldicarb poisoning diagnosis in dogs and cats

    Directory of Open Access Journals (Sweden)

    F.G. Xavier

    2007-10-01

    Full Text Available Avaliou-se a cromatografia em camada delgada (CCD como método de diagnóstico toxicológico para os casos de intoxicação por aldicarb em cães e gatos, utilizando-se 50 amostras de conteúdo gástrico obtidas durante a necropsia e 50 amostras de alimentos utilizados como iscas para intoxicar criminalmente os animais. Todas as amostras resultaram positivas para o aldicarb, mostrando ser a CCD uma técnica qualitativa eficiente, rápida e de baixo custo, com uso potencial na toxicologia veterinária forense.The present study concerns about the identification of aldicarb residues using thin-layer chromatography (TLC in 50 samples of gastric content obtained from the necropsy of dogs and cats and 50 samples of foods suspected of being used as baits. All samples resulted positive for aldicarb showing that the TLC is an efficient, fast and not expensive qualitative method for the detection of aldicarb, being useful for this purpose in the forensic veterinary toxicology.

  12. The deconjugation ability of bacteria isolated from the jejunal fluids in the blind loop syndrome with high sup 14 CO sub 2 excretion. Using the breath analysis technique and thin-layer chromatography

    Energy Technology Data Exchange (ETDEWEB)

    Shindo, K.; Yamazaki, R.; Mizuno, T.; Shionoiri, H.; Sugiyama, M. (Yokohama City Univ. School of Medicine, (Japan))

    1989-01-01

    Five patients with blind loop syndrome (Billroth II) were examined by measuring {sup 14}CO{sub 2} specific activity of expired breath samples taken at intervals after a meal containing glycine-1-{sup 14}C cholate. The 5 patients tested showed a marked increase of {sup 14}CO{sub 2} specific activity. Furthermore, the ability of deconjugation of bacteria isolated from the jejunal fluids in the efferent loop of these patients was tested by thin-layer chromatography. The bacterial species identified from the samples were as follows: enterococcus, Lactobacillus buchneri, L. bifidus, L. brevis, Eubacterium lentum, Bacteroides vulgaricus, B. filamentosum, Corynebacterium granulosum, Escherichia coli, Staphylococcus epidermidis, and Aerobacter aerogenes. These species of bacteria, except E. coli and A. aerogenes, showed the deconjugation ability by which conjugated bile acids in ox gall was hydrolyzed. Administration of chloramphenicol to the 5 patients reduced {sup 14}CO{sub 2} specific activity significantly. On the other hand, 9 healthy men who were tested showed a flat curve, and 8 of the 9 had no growth of bacteria isolated from the jejunal fluids. The remaining healthy man showed an over growth of E. coli and Pseudomonas aeruginosa, but the species did not have the ability of deconjugation.

  13. Suitability of thin-layer chromatography-flame ionization detection with regard to quantitative characterization of different fossil fuel products. II. Calibration methods concerning quantitative hydrocarbon-group type analysis

    Energy Technology Data Exchange (ETDEWEB)

    Vela, J.; Membrado, L.; Cebolla, V.L.; Ferrando, A.C. [CSIC, Zaragoza (Spain). Inst. de Carboquimica, Dept. de Procesos Quimicos

    1998-10-01

    Time-consuming external standard-based calibration methods are usually performed for hydrocarbon group type analysis (HGTA) of fossil fuels, regardless of the instrumental chromatographic technique. HGTA of a broad variety of coal and petroleum products was performed using a modern thin-layer chromatography-flame ionization detection (TLC-FID) system and a rapid method based on internal normalization. Repeatability, linear intervals, and sample load ranges for quantitative application of this method are given, namely a heavy oil and its derived hydrocracked products, raw and chemically-modified petroleum asphaltenes, a coal-tar pitch, several coal extracts, and coal hydroliquefaction products. Results from external standard calibration and a normalization method (both obtained by TLC-FID) are in agreement, and they are validated using TLC-ultraviolet scanning. The use of the latter demonstrates that TLC-FID can also be applied to products such as coal extracts and hydroliquefaction products, despite these products being more volatile than petroleum asphaltenes or heavy oils. 14 refs., 3 figs., 5 tabs.

  14. Delamination of Compressed Thin Layers at Corners

    DEFF Research Database (Denmark)

    Sørensen, Kim D.; Jensen, Henrik Myhre; Clausen, Johan

    2008-01-01

    An analysis of delamination for a thin elastic layer under compression, attached to a substrate at a corner is carried out. The analysis is performed by combining results from interface fracture mechanics and the theory of thin shells. In contrast with earlier results for delamination on a flat...

  15. Physicochemical properties of silica gel coated with a thin layer of polyaniline (PANI) and its application in non-suppressed ion chromatography.

    Science.gov (United States)

    Sowa, Ireneusz; Kocjan, Ryszard; Wójciak-Kosior, Magdalena; Swieboda, Ryszard; Zajdel, Dominika; Hajnos, Mieczysław

    2013-10-15

    Physicochemical properties of a new sorbent and its potential application in non-suppressed ion chromatography (IC) have been investigated. The sorbent was obtained in a process of covering silica gel particles with a film of polyaniline (PANI). The properties of silica modified with polyaniline such as particle size, porosity, average quantity of polyaniline covering carrier and density of sorbent were determined. In our study the following methods were used: microscopic analysis, laser diffraction technique, combustion analysis, mercury porosimetry and helium pycnometry. Column with the newly obtained packing was used for the separation of inorganic anions. Optimized chromatographic system was successfully employed for analysis of iodide and bromide in selected pharmaceutical products (Bochnia salt and Iwonicz salt) applied in chronic respiratory disease. Analysis was carried out using 0.1M solution of HCl in mixture of methanol/water (50:50v/v) as a mobile phase; the flow rate was 0.3 mL min(-1), temperature was 24°C and λ=210 nm. Validation parameters such as correlation coefficient, RSD values, recovery, detection and quantification limits were found to be satisfactory.

  16. Delamination of Compressed Thin Layers at Corners

    DEFF Research Database (Denmark)

    Sørensen, Kim Dalsten; Jensen, Henrik Myhre; Clausen, Johan

    2008-01-01

    An analysis of delamination for a thin elastic layer under compression, attached to a substrate at a corner is carried out. The analysis is performed by combining results from interface fracture mechanics and the theory of thin shells. In contrast with earlier results for delamination on a flat s...... results for the fracture mechanical properties have been obtained, and these are applied in a study of the effect of contacting crack faces. Special attention has been given to analyse conditions under which steady state propagation of buckling driven delamination takes place.......An analysis of delamination for a thin elastic layer under compression, attached to a substrate at a corner is carried out. The analysis is performed by combining results from interface fracture mechanics and the theory of thin shells. In contrast with earlier results for delamination on a flat...

  17. Study on Thin-layer Chromatography Separation and Anti-bacterial Activity of Mentha spicata Linn Essential Oil%留兰香挥发油的薄层分离及抗菌活性研究

    Institute of Scientific and Technical Information of China (English)

    张晓伟; 李青雨; 王德国; 石倩倩; 王佳华

    2011-01-01

    [目的]对留兰香挥发油的组分及抗菌活性进行研究.[方法]采用薄层色谱法对留兰香挥发油的组分进行初步分离,采用扩散法及紫外可见分光光度法对留兰香挥发油的抗菌活性进行测定.[结果]以石油醚:乙酸乙酯(V:V=6:1)为层析液时,留兰香挥发油的分离效果最好,分离出4种主要物质;留兰香精油对3种试验菌株的抑菌性为枯草芽孢杆菌(Bacillus subtdis)>金黄色葡萄球菌(Staphylococcus aureus)>大肠杆菌(Escherichia coli);对枯草芽孢杆菌、金黄色葡萄球菌、大肠杆菌的最低抑菌浓度(MIC)分别为:0.50,1.00,3.50μl/ml.[结论]留兰香挥发油具有抑菌作用,这为综合开发留兰香提供了理论基础.%[ Objective ] To study the composition and the anti-bacterial activity of volatile oil from Mentha spicata Linn. [ Method ] Using thin-layer chromatography ( TLC ), the compositions of essential oil from Mentha spicata Linn were separated. The inhibitory activity was determined by diffusion method combining with UV spectrophotometry. [ Result] Using petroleum ether- ethyl acetate ( V: V =6:1 ) as chromatography liquid, the essential oil from Mentha spicata Linn was best in separation and four components were obtained. The inhibitory effect of volatile oil from Mentha spicata Linn to three test strains was determined to be Bacillus subtilis > Staphylococcus aureus > Escherichia coli with MIC value of 0.50, 1.00 and 3.50 ul/ml, respectively. [ Conclusion ] The volatile oil from Mentha spicata Linn had anti-bacterial effect, which provided theoretical basis for comprehensive development of Mentha spicata Linn.

  18. Ionic liquids as additive in thin layer chromatography on separation of amino acids%离子液体作薄层色谱添加剂对氨基酸分离的研究

    Institute of Scientific and Technical Information of China (English)

    刘建平; 何丽君

    2011-01-01

    The separation of two alkaline amino acids ( argi-nine and lysine) was performed using 1-butyl-3-methylimid-azolium tetrafluoroborate ionic liquid ( [ Bmim ] BF4 ) as the eluent additives in thin layer chromatography. The addition of ionic liquid improved the separation the free silanol group markedly. The retardation factor ( R1) of the analytes firstly increased and then remained constant with the increase of the concentration of ionic liquids. In addition,the comparison results showed that the inhibition effect of [ Bmim ] PF6 for free silanol group was more effective than that of [ Bmim] BF4.%将1-丁基-3-甲基咪唑基四氟硼酸盐([Bmim]BF4)离子液体作为薄层色谱展开剂添加剂,讨论了[Bmim]BF4浓度对精氨酸和赖氨酸两种碱性氨基酸分离的影响.结果表明:添加离子液体能有效改善碱性氨基酸的展开效果,而且分析物的Rf值随离子液体浓度的增加而增加,浓度增加到一定后Rf保持不变.另外,比较了[Bmim]PF6和[Bmim]BF4两种离子液体对自由硅羟基抑制作用的效果,前者对自由硅羟基的抑制作用比后者更有效.

  19. Multi-Instrument Characterization of the Surfaces and Materials in Microfabricated, Carbon Nanotube-Templated Thin Layer Chromatography Plates. An Analogy to ‘The Blind Men and the Elephant’

    Energy Technology Data Exchange (ETDEWEB)

    Jensen, David S.; Kanyal, Supriya S.; Madaan, Nitesh; Hancock, Jared M.; Dadson, Andrew; Vail, Michael A.; Vanfleet, Richard; Shutthanandan, V.; Zhu, Zihua; Engelhard, Mark H.; Linford, Matthew R.

    2013-08-08

    Herein we apply a suite of surface/materials analytical tools to characterize some of the materials created in the production of microfabricated thin layer chromatography plates. Techniques used include X-ray photoelectron spectroscopy (XPS), valence band spectroscopy, static time-of-flight secondary ion spectrometry (ToF-SIMS) in both positive and negative ion modes, Rutherford backscattering spectroscopy (RBS), and helium ion microscopy (HIM). Materials characterized include: the Si(100) substrate with native oxide: Si/SiO2, alumina (35 nm) deposited as a diffusion barrier on the Si/SiO2: Si/SiO2/Al2O3, iron (6 nm) thermally evaporated on the Al2O3: Si/SiO2/Al2O3/Fe, the iron film annealed in H2 to make Fe catalyst nanoparticles: Si/SiO2/Al2O3/Fe(NP), and carbon nanotubes (CNTs) grown from the Fe nanoparticles: Si/SiO2/Al2O3/Fe(NP)/CNT. The Fe thin films and nanoparticles are found in an oxidized state. Some of the analyses of the CNTs/CNT forests reported appear to be unique: the CNT forest appears to exhibit an interesting ‘channeling’ phenomenon by RBS, we observe an odd-even effect in the ToF-SIMS spectra of Cn- species for n = 1 – 6, with ions at even n showing greater intensity than the neighboring signals, and ions with n ≥ 6 showing a steady decrease in intensity, and valence band characterization of CNTs using X-radiation is reported. The information obtained from the combination of the different analytical tools provides a more complete understanding of our materials than a single technique, which is analogous to the story of ‘The Blind Men and the Elephant’. (Of course there is increasing emphasis on the use of multiple characterization tools in surface and materials analysis.) The raw XPS and ToF-SIMS spectra from this study will be submitted to Surface Science Spectra for archiving.

  20. Thin layer chromatography of camel urine

    Directory of Open Access Journals (Sweden)

    Tarig Hab,

    2011-06-01

    Full Text Available General screening of 10 camel urine samples was carried out to determine the most common constituent of camel urine. Samples used were crude, ethanolic and chlorofermic extracts and compared with their lyophilysed urine. The study revealed the presence of alkaloids and triterpene. The objectives of this investigation are to verify camel urine major chemical constituents which are extremely valuable information for detecting new drugs of natural origin.

  1. Perovskite Thin Films via Atomic Layer Deposition

    KAUST Repository

    Sutherland, Brandon R.

    2014-10-30

    © 2014 Wiley-VCH Verlag GmbH & Co. KGaA. (Graph Presented) A new method to deposit perovskite thin films that benefit from the thickness control and conformality of atomic layer deposition (ALD) is detailed. A seed layer of ALD PbS is place-exchanged with PbI2 and subsequently CH3NH3PbI3 perovskite. These films show promising optical properties, with gain coefficients of 3200 ± 830 cm-1.

  2. Perovskite thin films via atomic layer deposition.

    Science.gov (United States)

    Sutherland, Brandon R; Hoogland, Sjoerd; Adachi, Michael M; Kanjanaboos, Pongsakorn; Wong, Chris T O; McDowell, Jeffrey J; Xu, Jixian; Voznyy, Oleksandr; Ning, Zhijun; Houtepen, Arjan J; Sargent, Edward H

    2015-01-01

    A new method to deposit perovskite thin films that benefit from the thickness control and conformality of atomic layer deposition (ALD) is detailed. A seed layer of ALD PbS is place-exchanged with PbI2 and subsequently CH3 NH3 PbI3 perovskite. These films show promising optical properties, with gain coefficients of 3200 ± 830 cm(-1) .

  3. Carbon nanofiber growth on thin rhodium layers

    NARCIS (Netherlands)

    Chinthaginjala, J.K.; Unnikrishnan, S.; Smithers, M.A.; Kip, G.A.M.; Lefferts, L.

    2012-01-01

    A thinlayer of carbon nanofibers (CNFs) was synthesized on a thin polycrystalline rhodium (Rh) metal layer by decomposing ethylene in the presence of hydrogen. Interaction of Rh crystals with carbon results in fragmentation and formation of Rh-nanoparticles, facilitating CNF growth. CNFs are immobil

  4. Ocorrência de aflatoxinas em arroz consumido por militares do Exército Brasileiro por cromatografia em camada delgada e cromatografia líquida de alta eficiência Incidence of aflatoxins in rice to be consumed by militaries in the brazilian army by thin layer chromatography and high performance liquid chromatography methods

    Directory of Open Access Journals (Sweden)

    Jader Oliveira da Silva

    2008-08-01

    November 2003 to febuary 2004 when the incidence of aflatoxins B1, B2, G1 and G2 was measured by thin layer chromatography (TLC and high performance liquid chromatography (HPLC methods. This work had the aim of comparing the thin layer chromatography and high performance liquid chromatography techniques and contributed for the quality control of the foods to be consumed by militaries of the Brazilian army, concerning the control of the aflatoxins levels. From a total of 30 samples were tested performed by tlc, no aflatoxin was detected. From 26 samples, analysed trough high performance liquid chromatography, 6 (23, 07% presented positive results for aflatoxin B1 with 0, 54 2, 04 µg/kg and, 1 (3, 84% presented a positive result for aflatoxins B2 with 1, 84 µg/kg.

  5. Subsurface Raman analysis of thin painted layers.

    Science.gov (United States)

    Conti, Claudia; Colombo, Chiara; Realini, Marco; Zerbi, Giuseppe; Matousek, Pavel

    2014-01-01

    Here we present, for the first time, an extension of spatially offset Raman spectroscopy to thin (tens of micrometers thick), highly turbid stratified media such as those encountered in paintings. The method permits the non-destructive interrogation of painted layers in situations where conventional Raman microscopy is not applicable due to high turbidity of the top layer(s). The concept is demonstrated by recovering the pure Raman spectra of paint sub-layers that are completely obscured by paint over-layers. Potential application areas include the analysis of paintings in art preservation and restoration avoiding the cross-sectional analysis used currently with this type of samples. The technique also holds promise for the development as a non-destructive subsurface tool for in situ analysis using portable instruments.

  6. Thin Layer Chromatography-High Performance Liquid Chromatographic Method for the Determination of Sudan Red in Food%薄层层析-高效液相色谱法测定食品中苏丹红

    Institute of Scientific and Technical Information of China (English)

    李春香; 黄坚; 马慧雪; 张祥

    2011-01-01

    The new method of determining banned additives in the food such as Sudan red Ⅰ and Ⅱ was established with thin layer chromatography(TLC) and high performance liquid chromatography(HPLC) two methods combined.Sudan red and impurities can be separated by silica gel plate.Under the condition of chromatography in setting,the concentration in the 0.1~20.0 μg/mL range,the peak areas(Y) and concentration(X) present good linear relationship,Sudan red Ⅰ,Ⅱ regression equations Y1=-18785+138962X,Y2=-2623+131432X.Correlation coefficient R1=0.9997,R2=0.9998.Its application of determing the Sudan red Ⅰ and Ⅱ in chili powder,chili oil,and tomato sauce was studied,and got the detection limit of 0.024 μg/g,0.027 μg/g,respectively.%建立了薄层层析-高效液相色谱联合技术测定食品中违禁添加物苏丹红Ⅰ、Ⅱ的新方法。采用硅胶板将苏丹红与杂质分离,在设定的色谱条件下测得浓度在0.1~20.0μg/mL范围内,峰面积(Y)与浓度(X)呈良好线性关系,苏丹红Ⅰ、的回归方程为Y1=-18785+138962X,Y2=-2623+131432X,相关系数R1=0.9997,R2=0.9998。将该法应用于辣椒粉、辣椒油、番茄酱等中的苏丹红Ⅰ、Ⅱ的检测。其检出限分别为0.024μg/g0、.027μg/g。

  7. The deconjugation ability of bacteria isolated from the jejunal fluids in the blind loop syndrome with high 14CO2 excretion--using the breath analysis technique and thin-layer chromatography.

    Science.gov (United States)

    Shindo, K; Yamazaki, R; Mizuno, T; Shionoiri, H; Sugiyama, M

    1989-01-01

    Five patients with blind loop syndrome (Billroth II) were examined by measuring 14CO2 specific activity of expired breath samples taken at intervals after a meal containing glycine-1-14C cholate. The 5 patients tested showed a marked increase of 14CO2 specific activity. Furthermore, the ability of deconjugation of bacteria isolated from the jejunal fluids in the efferent loop of these patients was tested by thin layer chromatography. The bacterial species identified from the samples were as follows: enterococcus, Lactobacillus (L) buchneri, L. bifidus, L. brevis, Eubacterium (E) lentum, Bacteroides (B) vulgaricus, B. filamentosum, Corynebacterium (C) granulosum, Escherichia (E) coli, Staphylococcus (S) epidermidis, and Aerobacter (A) aerogenes. These species of bacteria, except E. coli and A. aerogenes, showed the deconjugation ability by which conjugated bile acids in ox gall was hydrolyzed. Administration of chloramphenicol (1g per day for 14 days orally divided doses) to the 5 patients reduced 14CO2 specific activity significantly. On the other hand, 9 healthy men (control subjects) who were tested showed a flat curve, and 8 of the 9 had no growth of bacteria isolated from the jejunal fluids. The remaining healthy man showed an overgrowth of E. coli and Pseudomonas (P) aeruginosa, but the species did not have the ability of deconjugation. Thus, we concluded that the patients with blind loop syndrome(Billroth II) had the bacterial overgrowth in the efferent loop that contained species with deconjugation ability, and, as a result the bacterial overgrowth contributed to causing abnormalities (increased deconjugation) in the metabolism of bile acids in the small intestine. When the concentration of conjugated bile acids in the small intestine was reduced to levels below the critical micellar concentration by several factors, fat malabsorption and subsequent steatorrhea were induced (1,-4). Furthermore, H. Fromm and A. F. Hofmann presented in vivo that the patients

  8. An Electrochemical Experiment Using an Optically Transparent Thin Layer Electrode

    Science.gov (United States)

    DeAngelis, Thomas P.; Heineman, William R.

    1976-01-01

    Describes a unified experiment in which an optically transparent thin layer electrode is used to illustrate the techniques of thin layer electrochemistry, cyclic voltammetry, controlled potential coulometry, and spectroelectrochemistry. (MLH)

  9. Silver buffer layers for YBCO thin films

    Energy Technology Data Exchange (ETDEWEB)

    Azoulay, J. [Tel Aviv Univ. (Israel). Center for Technol. Education Holon

    1999-09-01

    A simple economical conventional vacuum system was used for evaporation of YBCO thin films on as-deposited unbuffered Ag layers on MgO substrates. The subsequent heat treatment was carried out in low oxygen partial pressure at a relative low temperature and short dwelling time. The films thus obtained were characterized for electrical properties using dc four probe electrical measurements and inspected for structural properties and chemical composition by scanning electron microscopy (SEM). (orig.)

  10. Method of transferring a thin crystalline semiconductor layer

    Science.gov (United States)

    Nastasi, Michael A.; Shao, Lin; Theodore, N. David

    2006-12-26

    A method for transferring a thin semiconductor layer from one substrate to another substrate involves depositing a thin epitaxial monocrystalline semiconductor layer on a substrate having surface contaminants. An interface that includes the contaminants is formed in between the deposited layer and the substrate. Hydrogen atoms are introduced into the structure and allowed to diffuse to the interface. Afterward, the thin semiconductor layer is bonded to a second substrate and the thin layer is separated away at the interface, which results in transferring the thin epitaxial semiconductor layer from one substrate to the other substrate.

  11. Determinação de aflatoxina B1 em pimenta (Piper nigrum L. e orégano (Origanum vulgare L. por cromatografia em camada delgada e densitometria Determination of aflatoxin B1 (Piper nigrum L. and oregano (Origanum vulgare L. by thin-layer chromatography and densitometry

    Directory of Open Access Journals (Sweden)

    Guilherme Prado

    2008-01-01

    Full Text Available An analytical study based on extraction with methanol-water, immunoaffinity cleanup and separation, identification and quantification of aflatoxin B1 by thin-layer chromatography,in ground black and white pepper and oregano was carried out. Validation of the applied methodology was done through accuracy and precision studies. Recoveries of aflatoxin B1 and relative standard deviations, from spice samples spiked at levels from 4.86 to 97.70 µg/kg, were, respectively, higher than 72% and lower than 20%. Application to spice samples available in Minas Gerais state, purchased at popular markets, showed no contamination with aflatoxin B1.

  12. 茶叶中儿茶素薄层色谱分离所用展开剂的优化%Optimization of developing solvents of high performance thin-layer chromatography for separating catechins in tea

    Institute of Scientific and Technical Information of China (English)

    王丽丽; 王坤波; 黄建安; 徐仲溪

    2012-01-01

    室温条件下,以硅胶板为固定相,用5种展开剂(体积比9:9:2的甲苯-丙酮-甲酸、5.0:10.0:1.0:0.5的甲苯-甲酸乙酯-甲醇-甲酸、8.0:5.0:15.0:0.3的甲苯-三氯钾烷-丙酮-甲酸、12.5:7.5:1.8:0.6的三氯钾烷-丙酮-甲醇-水、12.5:7.5:1.8:0.6的三氯钾烷-丙酮-甲酸-水)对茶叶中的儿茶素进行薄层色谱分离,筛选出其中较优的展开剂后,进一步优化其配比,并用其分离绿茶和白茶提取物中的儿茶素以进行验证.结果表明,以体积比12.5:7.5:2.2的三氯甲烷-丙酮-甲酸为展开剂,茶叶内主要的4种儿茶素单体(EGCg、EGC、ECg、EC)可得到良好分离,绿茶与白茶提取物中的儿茶素能较好地得以分离.%At room temperature, methylbenzene-acetone-formic acid (9∶9 ∶ 2, V/V), methylbenzene-ethyl formatemethanol-formic acid (5.0 ∶10.0∶ 1.0 ∶0.5, V/V), methylbenzene-chloroform-acetone-formic acid (8.0 ∶5.0∶ 15.0∶ 0.3, V/V), chloroform-acetone-methanol-water(12.5 ∶7.5 ∶1.8 ∶ 0.6, V/V) and chloroform-acetone-formic acid-water (12.5 ∶ 7.5 ∶ 1.8 ∶ 0.6, V/V) on silica gel marked as solvent Ⅰ,Ⅱ,Ⅲ,Ⅳ and Ⅴ respectively were applied as developing solvent respectively in high performance thin-layer chromatography (HPTLC) for isolating catechins in the tea. Among them, solvent Ⅴ was found to be the best for separation of catechins, this solvent was then modified mainly regarding the volume ratios of formic acid. The results showed the modified solvent Ⅴ, namely, chloroform- acetone- formic acid (12.5 ∶ 7.5 ∶2.2, V/V) was the optimum for separation of the four main catechins (EGCg, EGC, Ecg, EC) in the tea. The applicability of the optimized developing solvent was further confirmed by separation of catechins in the extracts of the green and the white tea.

  13. SDS-PAGE-薄层扫描联用法测定3种不同来源的乳铁蛋白%Determination of Lactoferrin from Different Sources by SDS-PAGE Followed by Thin Layer Chromatography Scanning

    Institute of Scientific and Technical Information of China (English)

    邢志恩; 王军; 戴蕴青; 陈燕卉; 陈敏

    2011-01-01

    目的:建立快速、简便测定鲜牛奶、转基因牛奶和人乳中乳铁蛋白的方法。方法:在对样品脱脂和去除酪蛋白时,水洗乳脂、酪蛋白以提高乳铁蛋白的回收率。通过十二烷基磺酸钠-聚丙烯酰胺凝胶电泳(sodiumdodecyl sulfate-polyacrylamide gel electrophoresis,SDS-PAGE)分离乳清蛋白,薄层扫描法定量。对电泳和薄层扫描的条件进行优化,电泳使用1.0mm×10齿的试样格、分离胶质量浓度12g/mL、分离电压100V、上样量5μL、染色3h、脱色2h;薄层扫描采取锯齿、双波长、透射的扫描方式,Y步长和摆幅宽分别为0.1mm和8mm。结果:可以分离不同来源乳中的乳铁蛋白、α-乳白蛋白和β-乳球蛋白;乳铁蛋白加标回收率分别为104.53%、108.37%,同板精密度RSD值为3.1003%和1.8151%,在100~2000μg/mL范围内呈线性关系,相关系数为0.9988和0.9990。结论:此方法可以用于3种乳中乳铁蛋白的测定。%The aim of this study was to develop a rapid and simple method for the determination of lactoferrin from fresh bovine milk,transgenic bovine milk and human milk.After removing fat by centrifugation and precipitating caseins by adjusting pH,the lactoferrin contents were separated by SDS-PAGE(100 V,12 g/mL gel,comb:1.0 × 10 teeth,5μL injection,staining for 3 h and destaining for 2 h);and then the target fractions in the gel were examined by thin layer chromatography scanner(transmission,zigzag scan,dual wavelength,swing width: 8 mm,delta Y: 0.1 mm).The results showed that good separation was achieved for lactoferrin(LF),α-lactalbumin(α-La) and β-lactoglobulin(β-Lg) from three different sources.The recoveries for LFI(LF standard obtained from fresh bovine milk) in fresh bovine milk and LFII(LF standard obtained from transgenic bovine milk) in transgenic bovine milk across three spike levels were 104.53% and 108.37%,respectively.The intra-plate assay precision RSDs for

  14. Thermal analysis of thin layer boilover

    Energy Technology Data Exchange (ETDEWEB)

    Kozanoglu, Bulent [Universidad de las Americas, Puebla (Mexico); Mechanical Engineering Department, Cholula, Puebla (Mexico); Ferrero, Fabio; Munoz, Miguel; Arnaldos, Josep; Casal, Joaquim [Universitat Politecnica de Catalunya, Barcelona (Spain)

    2008-10-15

    A mathematical model is developed to simulate the thin layer boilover phenomenon. This model takes into account convective currents as well as conduction and radiation absorption through the fuel layer and is resolved numerically employing a scheme of Runge-Kutta, combined with the numerical method of lines. Solutions of the model showed a good agreement with the experimental data, both from this work and by other authors, demonstrating the importance of the convective currents. The model provided velocities of these currents, of the same order of magnitude as the values reported in the technical literature. Thickness of the remaining fuel and the interface temperature are correctly calculated by the model, allowing the prediction of the time required for the boilover to start. (orig.)

  15. RF screening by thin resistive layers

    CERN Document Server

    Caspers, Friedhelm; González, C; Jensen, E; Keil, Eberhard; Morvillo, M; Ruggiero, F; Schröder, G; Zotter, Bruno W; Dyachkov, M

    1999-01-01

    We discuss the results of recent impedance measurements for an LHC dump kicker prototype, performed at CERN using the coaxial wire method. The kicker design includes a vacuum barrier consisting of a ceramic chamber internally coated with a thin metallic layer having good electric contact with the external beam pipe. For the bench test the coated ceramic tube was replaced by a kapton foil with a 0.2 \\mu\\m copper layer having the same DC resistance of 0.7 Ømega\\m. The measurements show that this resistive coating provides a very effective RF screening down to frequencies below 1 MHz, where the skin depth is two orders of magnitude larger than the layer thickness and one could expect full penetration of the electromagnetic fields. We also present simulation results and analytic considerations in agreement with the measurements, showing that the return currents almost entirely flow through the copper layer down to frequencies where the reactive impedance of the kicker elements located behind it becomes comparabl...

  16. An improved method for thin layer chromatographic analysis of saponins.

    Science.gov (United States)

    Sharma, Om P; Kumar, Neeraj; Singh, Bikram; Bhat, Tej K

    2012-05-01

    Analysis of saponins by thin layer chromatography (TLC) is reported. The solvent system was n-butanol:water:acetic acid (84:14:7). Detection of saponins on the TLC plates after development and air-drying was done by immersion in a suspension of sheep erythrocytes, followed by washing off the excess blood on the plate surface. Saponins appeared as white spots against a pink background. The protocol provided specific detection of saponins in the saponins enriched extracts from Aesculusindica (Wall. ex Camb.) Hook.f., Lonicera japonica Thunb., Silene inflata Sm., Sapindusmukorossi Gaertn., Chlorophytum borivilianum Santapau & Fernandes, Asparagusadscendens Roxb., Asparagus racemosus Willd., Agave americana L., Camellia sinensis [L.] O. Kuntze. The protocol is convenient, inexpensive, does not require any corrosive chemicals and provides specific detection of saponins.

  17. Thin layer convection-drying of mushrooms

    Energy Technology Data Exchange (ETDEWEB)

    Pal, U.S.; Chakraverty, A. [Indian Inst. of Tech., Kharagpur (India). Dept. of Agricultural Engineering

    1997-06-01

    Dehydration characteristics of the Oyster Pleurotus variety of mushroom were studied. Both untreated and treated (steam blanching followed by sulphiting and citric acid pretreatment before drying) mushrooms were dried in the thin layer experimental equipment at each of the drying air temperatures of 45, 50 and 60{sup o}C with air velocities of 0.9 and 1.6 m/s. Studies on the equilibrium moisture content (EMC) of both untreated and treated dehydrated mushrooms were performed at different relative humidities ranging from 11.2 to 86.3% at 30{sup o}C. Taking drying time and quality of the dehydrated product into account, a combination of a drying air temperature of 50{sup o}C and an air velocity of 0.9 m/s appears to be suitable for drying of both untreated and treated mushrooms for a good dehydrated product. (author)

  18. Plant thin cell layers: update and perspectives

    Directory of Open Access Journals (Sweden)

    Teixeira da Silva Jaime A.

    2015-12-01

    Full Text Available Thin cell layers (TCLs are small and versatile explants for the in vitro culture of plants. At face value, their morphogenic productivity may appear to be less than conventional explants, but once the plant growth correction factor and geometric factor have been applied, the true (potential productivity exceeds that of a conventional explant. It is for this reason that for almost 45 years, TCLs have been applied to the in vitro culture of almost 90 species or hybrids, mainly ornamentals and orchids, but also to field and vegetable crops and medicinal plants. Focusing on 12 new studies that have emerged in the recent past (2013-2015, this paper brings promise to other horticultural species that could benefit from the use of TCLs.

  19. Plant-determined variation in the cardenolide content, thin-layer chromatography profiles, and emetic potency of monarch butterflies,Danaus plexippus L. Reared on milkweed plants in California: 2.Asclepias speciosa.

    Science.gov (United States)

    Brower, L P; Seiber, J N; Nelson, C J; Lynch, S P; Holland, M M

    1984-04-01

    . About 80% of the lower emetic potency of monarchs reared on A. speciosa compared to those reared onA. eriocarpa appears attributable to the higher polarity of the cardenolides inA. speciosa. Thin-layer Chromatographie separation of the cardenolides in two different solvent systems showed that there are 23 cardenolides in theA. speciosa plants of which 20 are stored by the butterflies. There were no differences in the cardenolide spot patterns due either to geographic origin or the sex of the butterflies. As when reared onA. eriocarpa, the butterflies did not store the plant cardenolides withR f values greater than digitoxigenin. However, metabolic transformation of the cardenolides by the larvae appeared minor in comparison to when they were reared onA. eriocarpa. AlthoughA. eriocarpa andA. speciosa contain similar numbers of cardenolides and both contain desglucosyrioside, the cardenolides ofA. speciosa overall are more polar. ThusA. speciosa has no or only small amounts of the nonpolar labriformin and labriformidin, whereas both occur in high concentrations inA. eriocarpa. A. speciosa plants and butterflies also contain uzarigen, syriogenin, and possibly other polar cardenolides withR f values lower than digitoxin. The cardenolide concentration in the leaves is not only considerably less than inA. eriocarpa, but the latex has little to immeasurable cardenolide, whereas that ofA. eriocarpa has very high concentrations of several cardenolides. Quantitative analysis ofR f values of the cardenolide spots, their intensities, and their probabilities of occurrence in the chloroform-methanol-formamide TLC system produced a cardenolide fingerprint pattern very different from that previously established for monarchs reared onA. eriocarpa. This dispels recently published skepticism about the predictibility of chemical fingerprints based upon ingested secondary plant chemicals.

  20. Scaling percolation in thin porous layers

    Science.gov (United States)

    Médici, E. F.; Allen, J. S.

    2011-12-01

    Percolation in porous media is a complex process that depends on the flow rate, material, and fluids properties as well as the boundary conditions. Traditional methods of characterizing percolation rely upon visual observation of a flow pattern or a pressure-saturation relation valid only in the limit of no flow. In this paper, the dynamics of fluid percolation in thin porous media is approached through a new scaling. This new scaling in conjunction with the capillary number and the viscosity ratio has resulted in a linear non-dimensional correlation of the percolation pressure and wetted area in time unique to each porous media. The effect of different percolation flow patterns on the dynamic pressure-saturation relation can be condensed into a linear correlation using this scaling. The general trend and implications of the scaling have been analyzed using an analytical model of a fluid percolating between two parallel plates and by experimental testing on thin porous media. Cathode porous transport layers (PTLs), also known as gas diffusion layers, of a proton exchange membrane (PEM) fuel cell having different morphological and wetting properties were tested under drainage conditions. Images of the fluid percolation evolution and the percolation pressure in the PTLs were simultaneously recorded. A unique linear correlation is obtained for each type of PTL samples using the new scaling. The correlation derived from this new scaling can be used to quantitatively characterize porous media with respect to percolation. While the characterization method discussed herein was developed for the study of porous materials used in PEM fuel cells, the method and scaling are applicable to any porous media.

  1. Development and validation of a simple high performance thin layer chromatography method combined with direct 1,1-diphenyl-2-picrylhydrazyl assay to quantify free radical scavenging activity in wine.

    Science.gov (United States)

    Agatonovic-Kustrin, Snezana; Morton, David W; Yusof, Ahmad P

    2016-04-15

    The aim of this study was to: (a) develop a simple, high performance thin layer chromatographic (HPTLC) method combined with direct 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay to rapidly assess and compare free radical scavenging activity or anti-oxidant activity for major classes of polyphenolics present in wines; and (b) to investigate relationship between free radical scavenging activity to the total polyphenolic content (TPC) and total antioxidant capacity (TAC) in the wine samples. The most potent free radical scavengers that we tested for in the wine samples were found to be resveratrol (polyphenolic non-flavonoid) and rutin (flavonoid), while polyphenolic acids (caffeic acid and gallic acid) although present in all wine samples were found to be less potent free radical scavengers. Therefore, the total antioxidant capacity was mostly affected by the presence of resveratrol and rutin, while total polyphenolic content was mostly influenced by the presence of the less potent free radical scavengers gallic and caffeic acids.

  2. Thin layer Characterization by ZGV Lamb modes

    Energy Technology Data Exchange (ETDEWEB)

    Ces, Maximin; Clorennec, Dominique; Royer, Daniel; Prada, Claire, E-mail: maximin.ces@espci.fr [Laboratoire Ondes et Acoustique, ESPCI- Universite Paris 7- CNRS UMR 7587, 10 rue Vauquelin, 75231 Paris Cedex 05- France (France)

    2011-01-01

    Ultrasonic non-destructive testing of plates can be performed with Lamb modes guided by the structure. Non contact generation and detection of the elastic waves can be achieved with optical means such as a pulsed laser source and an interferometer. With this setup, we propose a method using zero group velocity (ZGV) Lamb modes rather than propagating modes. These ZGV modes have noteworthy properties, in particular their group velocity vanishes, whereas their phase velocity remains finite. Thus, a significant part of the energy deposited by the pulsed laser can be trapped in the source area. For example, in a homogeneous isotropic plate and at the minimum frequency of the S{sub 1}-Lamb mode a very sharp resonance can be observed, the frequency of which only depends on the plate thickness, for a given material. In fact, other ZGV modes exist and the set of ZGV resonance frequencies provide a local and absolute measurement of Poisson's ratio. These non-propagating modes can also be used to characterize multi-layered structures. Experimentally, we observed that a thin (500 nm) gold layer deposited on a thick (1.5 mm) Duralumin plate induces a sensitive down-shift of the set of ZGV resonance frequencies. This shift, which is typically 5 kHz for the S{sub 1}-Lamb mode at 1.924 MHz, can be approximated by a formula providing the layer thickness. Thickness down to 100 nm can be estimated by this method. Such a sensitivity with conventional ultrasound inspection by acoustic microscopy would require an operating frequency in the GHz range.

  3. Thin-Layer Fuel Cell for Teaching and Classroom Demonstrations

    Science.gov (United States)

    Shirkhanzadeh, M.

    2009-01-01

    A thin-layer fuel cell is described that is simple and easy to set up and is particularly useful for teaching and classroom demonstrations. The cell is both an electrolyzer and a fuel cell and operates using a thin layer of electrolyte with a thickness of approximately 127 micrometers and a volume of approximately 40 microliters. As an…

  4. A simple and rapid method for the determination of taxol produced by fungal endophytes from medicinal plants using high performance thin layer chromatography%高效薄层色谱法快速测定由药用植物内生真菌产生的紫杉醇

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Taxol is an important anticancer drug used widely in the clinical field. In this study, some endophytic fungi were isolated from selected medicinal plants, and were screened for their potential in the production of taxol, using a rapid separation technique of high performance thin layer chromatography ( HPTLC ). Of the 20 screened fungi, only 13 fungal species produced taxol in the artificial culture medium.The results of HPTLC showed that the 13 fungal species had identical ultraviolet (UV) characteristics, positive reactivity with a spray reagent, yielding a blue spot, which turned to dark gray after 24 hours, and had Rf values identical to that of the authentic taxol. The amount of taxol was also quantified by comparing the peak area and the peak height of the fungal samples with those of authentic taxol.

  5. 薄层色谱-热辅助水解甲基化-气相色谱法测定生物柴油中的甘油酯%Determination of Glycerides in Biodiesel by Thin Layer Chromatography-Thermally Assisted Hydrolysis and Methylation-gas Chromatography

    Institute of Scientific and Technical Information of China (English)

    王鹏; 孙杨; 刘哲益; 傅宇飞; 潘再法; 王丽丽

    2011-01-01

    A method was developed for the determination of residual glycerides in biodiesel on the basis of thin layer chromatography-thermally assisted hydrolysis and methylation-gas chromatography (TLC-THM-GC) using a pyrolysis-GC system. With the THM in the presence of an organic alkali, trimethylsulfonium hydroxide (TMSH), glycerides were converted into their corresponding fatty acid methyl esters. Thus, residual glycerides could be determined well by the total peak area of fatty acid methyl esters formed. Glycerides in samples were separated by TLC, and then were extracted. The results showed that by adding 3 μL TMSH (0. 1 mol/L) methanol solution to 3 μL extract of sample and methylating the mixture at 350 °C , the glycerides would be sensitively determined. The calibration curves of monoglyceride, diglyceride and triglyceride exhibited good linearity with the regression coefficients from 0. 9863 to 0. 9993 at the concentration ranged from 60 to 2000 mg/L. The reproduc-ibility was fairly good with the RSD (n = 5) from 3. 2% to 7. 2% for four kinds of diglycerides at 250 mg/L concentration level. The potential of the proposed method was assessed by applying it to the determination of residual glyceride in biodiesel. The results prove this TLC-THM-GC technique is an accurate and sensitive method for determining residual glyceride in biodiesel samples.%建立了薄层色谱-热辅助水解甲基化-气相色谱法测定生物柴油中残余甘油酯含量的方法.样品中的甘油酯经薄层色谱分离,萃取后与三甲基氢氧化硫(0.1 mol/L)各3 μL先后加入到样品杯中,在350℃下,于裂解器中进行衍生化反应,气相色谱测定生成的脂肪酸甲酯,确定甘油酯的含量.生物柴油中常见的甘油一酯、二酯、三酯在60~2000 mg/L浓度范围内线性关系良好,r2为0.9863~0.9993.对于浓度为250 mg/L的4种甘油二酯重复测定5次,相对标准偏差为3.2%~7.2%.本方法对实际样品中的甘油酯的测定结果表明,方法准确、灵敏.

  6. Thin layer joining by gas adsorption

    Energy Technology Data Exchange (ETDEWEB)

    Taga, Yasunori, E-mail: y-taga@isc.chubu.ac.jp; Fukumura, Toshio

    2014-10-01

    Highlights: • We report thin layer molecular joining between glass and COP by gas adsorption. Thickness of joining layer is 1–2 nm and joining process was carried out at low temperature at about 100 °C. • Adhesion strength measured by 180 degree peel test revealed to be 1–10 N/25 mm and the joined stack showed high durability for practical use. - Abstract: Attempt has been made to join borosilicate glass and cycloolefin (COP) polymer film by using gas adsorption method. After corona plasma treat, COP was exposed to (3-glycidoxypropyl) trimethoxysilane (GPS) and glass to (3-aminopropyl) triethoxysilane (APS) both in air atmosphere, resulting in co-adsorption of water vapor in the atmosphere and organosilane gases. Surface characterization of plasma treated and gas adsorbed surfaces was carried out by X-ray photoelectron spectroscopy (XPS) using Mg Kα X-ray source. Joining was carried out by a roll laminator after contact of both surfaces at room temperature, followed by annealing at 130 °C for 10 min. Adhesion strength was evaluated by 180 degree peel test based on ASTM D-903 and durability was examined under the conditions of 60 °C and 95% RH. It was found that after plasma treatment, complex functional groups such as C-H, C-O, C=O, O-C=O and CO{sub 3} were found on COP and O-H on glass. Thickness of GPS gas adsorption layer on COP was evaluated by the XPS to be at least 1.1 nm by taking inelastic mean free path of Si{sub 2p} photoelectron into consideration. Joining force was found to be more than 5 N/25 mm corresponding to almost equal to COP bulk tensile strength. In addition, durability of this adhesion strength remained unchanged over 2000 h even after exposure to the durability test conditions of 60 °C and 95% RH. The results can be explained in terms of formation of H-H hydrogen bonding and Si-O covalent bonding via silanols will be made at the interface as a result of lamination and annealing processes. In conclusion, ultrathin joining method

  7. 薄层层析-分光光度法检测纤毛虫中的卵磷脂%Determination of Phosphatidylcholine in Protozoa by Thin Layer Chromatography-Spectroscopy

    Institute of Scientific and Technical Information of China (English)

    盛东峰; 孙明俊

    2012-01-01

    卵磷脂(PC)在纤毛虫中含量比较稳定,通过纤毛虫PC含量来估计出纤毛虫的量.采用薄层层析-分光光度法测定了山羊瘤胃纤毛虫中PC的含量,结果表明山羊瘤胃纤毛虫PC含量为17.9~24.1 mg/g.该法简便、快速、有效,可作为纤毛虫卵磷脂含量的检测方法.%Phosphatidylcholine (PC) is a special stable marker in the protozoa, the content of which could be used as an indicator for evaluating the quantity of protozoa. Thin layer chrornatography-spectroscopy was established to determine the content of PC in the protozoa. The results showed that the content of phosphatidylcholine in protozoa was in the range of 17.8~ 24.2 mg/g. In conclusion, this method was simple, rapid and efficient. It can be used for determining the relative content of phosphatidylcholine in protozoa.

  8. Thin-layer Chromatographic (TLC) Separations and Bioassays of Plant Extracts to Identify Antimicrobial Compounds

    OpenAIRE

    Kagan, Isabelle A.; Flythe, Michael D.

    2014-01-01

    A common screen for plant antimicrobial compounds consists of separating plant extracts by paper or thin-layer chromatography (PC or TLC), exposing the chromatograms to microbial suspensions (e.g. fungi or bacteria in broth or agar), allowing time for the microbes to grow in a humid environment, and visualizing zones with no microbial growth. The effectiveness of this screening method, known as bioautography, depends on both the quality of the chromatographic separation and the care taken wit...

  9. Thin layer drying of tomato slices.

    Science.gov (United States)

    Das Purkayastha, Manashi; Nath, Amit; Deka, Bidyut Chandra; Mahanta, Charu Lata

    2013-08-01

    The hot air convective drying characteristics of blanched tomato (Lycopersicon esculantum L.) slices have been investigated. Drying experiments were carried out at four different temperatures (50, 60, 65 and 70 °C). The effect of drying temperatures on the drying behavior of the tomato slices was evaluated. All drying experiments had only falling rate period. The average effective diffusivity values varied from 0.5453 × 10(-9) to 2.3871 × 10(-9) m(2)/s over the temperature range studied and the activation energy was estimated to be 61.004 kJ/mol. In order to select a suitable form of the drying curve, six different thin layer drying models (Henderson-Pabis, Page, Diamante et al., Wang and Singh, Logarithmic and Newton models) were fitted to the experimental data. The goodness of fit tests indicated that the Logarithmic model gave the best fit to experimental results, which was closely followed by the Henderson-Pabis model. The influence of varied drying temperatures on quality attributes of the tomato slices viz. Hunter color parameters, ascorbic acid, lycopene, titratable acidity, total sugars, reducing sugars and sugar/acid ratio of dried slices was also studied. Slices dried at 50 and 60 °C had high amount of total sugars, lycopene, sugar/acid ratio, Hunter L- and a-values. Drying of slices at 50 °C revealed optimum retention of ascorbic acid, sugar/acid ratio and red hue, whereas, drying at higher temperature (65 and 70 °C) resulted in a considerable decrease in nutrients and colour quality of the slices.

  10. Thickness and dielectric constant determination of thin dielectric layers

    NARCIS (Netherlands)

    Bruijn, de Helene E.; Minor, Marcel; Kooyman, Rob P.H.; Greve, Jan

    1993-01-01

    We derive a method for the determination of the dielectric constant and thickness of a thin dielectric layer, deposited on top of a thick dielectric layer which is in turn present on a metal film. Reflection of p- and s-polarized light from the metal layer yields minima for certain angles of inciden

  11. Thin-Layer Spectroelectrochemistry on an Aqueous Micro-drop

    Energy Technology Data Exchange (ETDEWEB)

    Schroll, Cynthia A.; Chatterjee, Sayandev; Heineman, William R.; Bryan, Samuel A.

    2012-05-01

    Here we report the ability to perform thin-layer spectroelectrochemistry using an aqueous micro-drop. The thin-layer setup was evaluated using [Fe(CN){sub 6}]{sup 3-/4-} as a absorbance based model analyte and [Ru(bpy){sub 3}]{sup 3+/2+} as an emission based model analyte. The thin-layer capability of the electrochemical cell was validated with these two chemical systems using cyclic voltammetry, and UV-visible absorbance and luminescence spectroscopies. This work supports our FCRD process monitoring work and is a direct result of the collaboration under subcontract with University of Cincinnati.

  12. 薄层色谱法鉴定原子印油印文盖印形成时间%Identifying stamping time of atomic seal ink on paper by thin layer chromatography

    Institute of Scientific and Technical Information of China (English)

    张凌燕; 潘自勤; 祁堃; 荣静月; 陈浩

    2012-01-01

    建立了用薄层色谱法鉴定原子印油印文盖印形成时间的新方法.详细研究了萃取剂、反应时间、反应温度等的影响,建立了萃取动力学曲线.在优化条件下,盖印时间在36个月内的新鲜原子印油印文,萃取速率值与盖印时间的线性方程为y=-0.0166x+0.7025(R2=0.9554),检测下线为3个月.用该方法对10余种原子印文盖印形成时间进行了鉴定,均有同样结果.%A novel method for identifying the stamping time of atomic seal ink on paper by thin layer chromato-graph was established. The influences of extractants, reaction time and reaction temperature were studied, and the dynamic extraction curves were plotted. Under the optimized conditions, the linear regression equation of the extraction rate and stamping time is y = 0. 166x + 0. 7025 (R2 = 0. 9554) for atomic seal ink stamped within 36 months with the lower detection limit of 3 months. The method has been used for identifying stamping times of more than 10 atomic seal ink of different brands and the similar results have been obtained.

  13. Plant-determined variation in the cardenolide content, thin-layer chromatography profiles, and emetic potency of monarch butterflies,Danaus plexippus reared on the milkweed,Asclepias eriocarpa in California.

    Science.gov (United States)

    Brower, L P; Seiber, J N; Nelson, C J; Lynch, S P; Tuskes, P M

    1982-03-01

    This paper is the first in a series on cardenolide fingerprinting of the monarch butterfly. New methodologies are presented which allow both qualitative and quantitative descriptions of the constituent cardenolides which these insects derive in the wild from specificAsclepias foodplants. Analyses of thin-layer Chromatographic profiles ofAsclepias eriocarpa cardenolides in 85 individual plant-butterfly pairs collected at six widely separate localities in California indicate a relatively invariant pattern of 16-20 distinct cardenolides which we here define as theAsclepias eriocarpa cardenolide fingerprint profile. Cardenolide concentrations vary widely in the plant samples, but monarchs appear able to regulate total storage by increasing their concentrations relative to their larval host plant when reared on plants containing low concentrations, and vice versa. Forced-feeding of blue jays with powdered butterfly and plant material and with one of the constituent plant cardenolides, labriformin, established that theA. eriocarpa cardenolides are extremely emetic, and that monarchs which have fed on this plant contain an average of 16 emetic-dose fifty (ED50) units. The relatively nonpolar labriformin and labriformidin in the plant are not stored by the monarch but are metabolized in vivo to desglucosyrioside which the butterfly does store. This is chemically analogous to the way in which monarchs and grasshoppers metabolize another series of milkweed cardenolides, those found inA. curassavica. It appears that the sugar moiety through functionality at C-3' determines which cardenolides are metabolized and which are stored. The monarch also appears able to store several lowR f cardenolides fromA. eriocarpa without altering them. Differences in the sequestering process in monarchs and milkweed bugs (Oncopeltus) may be less than emphasized in the literature. The monarch is seen as a central organism involved in a coevolutionary triad simultaneously affecting and affected

  14. Delamination of Compressed thin Layers at Corners

    DEFF Research Database (Denmark)

    Clausen, Johan; Jensen, Henrik Myhre; Sørensen, Kim Dalsten

    2008-01-01

    An analysis of delamination for a thin elastic film, attached to a substrate with a corner, is carried out. The film is in compression and the analysis is performed by combining results from fracture mechanics and the theory of thin shells. The results show a very strong dependency of the angle...

  15. Buffer layer for thin film structures

    Science.gov (United States)

    Foltyn, Stephen R.; Jia, Quanxi; Arendt, Paul N.; Wang, Haiyan

    2006-10-31

    A composite structure including a base substrate and a layer of a mixture of strontium titanate and strontium ruthenate is provided. A superconducting article can include a composite structure including an outermost layer of magnesium oxide, a buffer layer of strontium titanate or a mixture of strontium titanate and strontium ruthenate and a top-layer of a superconducting material such as YBCO upon the buffer layer.

  16. Diamond nucleation on surface of C60 thin layers

    Institute of Scientific and Technical Information of China (English)

    杨国伟; 袁放成; 刘大军; 何金田; 张兵临

    1997-01-01

    Diamond nucleation on the surface of C60 thin layers and intermediate layer of Si substrates are studied by scanning electron microscopy (SEM). The cross-section SEM images of diamond films show that diamond grains really nucleate on the surface of C60 thin layers. The SEM images of diamond nucleating sites show the nucleating aggregation of diamond on C60 surfaces. The preferential oriented diamond films are observed. The plasma pre-treatment of C60 sublimating layers is a key factor for diamond nucleation.

  17. Layer-by-Layer Assembly of a pH-Responsive and Electrochromic Thin Film

    Science.gov (United States)

    Schmidt, Daniel J.; Pridgen, Eric M.; Hammond, Paula T.; Love, J. Christopher

    2010-01-01

    This article summarizes an experiment on thin-film fabrication with layer-by-layer assembly that is appropriate for undergraduate laboratory courses. The purpose of this experiment is to teach students about self-assembly in the context of thin films and to expose students to the concepts of functional polymeric coatings. Students dip coat…

  18. The Physical Context for Thin Layers in the Coastal Ocean

    Science.gov (United States)

    2010-03-01

    their statistics is in preparation. This latter article will be co-authored by MIT/WHOI Joint Program student Nick Woods who was partially supported...Abstract OS34M-05. Fratantoni, D. M., B. A. Hodges , and J. M. Lund, Autonomous Investigation of Thin Phytoplankton Layers and Their Physical Context...Poster presented at AGU Ocean Sciences Meeting, March 2008, Orlando, FL. Hodges , B. A., Fratantoni, D. M, and J. M. Lund, Propagation of a thin layer

  19. Thin layer structure of dissipation rate of scalar turbulence

    Institute of Scientific and Technical Information of China (English)

    ZHOU; Haibing; (周海兵); CUI; Guixiang; (崔桂香); XU; Chunxiao; (许春晓); ZHANG; Zhaoshun; (张兆顺)

    2003-01-01

    The structure of scalar turbulence dissipation is studied by means of direct numerical simulation. It has been discovered that the scalar turbulence dissipation exhibits thin layer structure. Based on the analysis of transportation equation of scalar turbulence dissipation, we have investigated the effect of turbulent strains on the generation of scalar turbulence dissipation and found that fluctuating scalar gradients trend to the third principal direction of turbulent strains. Therefore the generation of the thin layer structure of scalar turbulence dissipation is well interpreted.

  20. Buffer layers for high-Tc thin films on sapphire

    Science.gov (United States)

    Wu, X. D.; Foltyn, S. R.; Muenchausen, R. E.; Cooke, D. W.; Pique, A.; Kalokitis, D.; Pendrick, V.; Belohoubek, E.

    1992-01-01

    Buffer layers of various oxides including CeO2 and yttrium-stabilized zirconia (YSZ) have been deposited on R-plane sapphire. The orientation and crystallinity of the layers were optimized to promote epitaxial growth of YBa2Cu3O(7-delta) (YBCO) thin films. An ion beam channeling minimum yield of about 3 percent was obtained in the CeO2 layer on sapphire, indicating excellent crystallinity of the buffer layer. Among the buffer materials used, CeO2 was found to be the best one for YBCO thin films on R-plane sapphire. High Tc and Jc were obtained in YBCO thin films on sapphire with buffer layers. Surface resistances of the YBCO films were about 4 mOmega at 77 K and 25 GHz.

  1. Thin-film organic photonics molecular layer deposition and applications

    CERN Document Server

    Yoshimura, Tetsuzo

    2011-01-01

    Among the many atomic/molecular assembling techniques used to develop artificial materials, molecular layer deposition (MLD) continues to receive special attention as the next-generation growth technique for organic thin-film materials used in photonics and electronics. Thin-Film Organic Photonics: Molecular Layer Deposition and Applications describes how photonic/electronic properties of thin films can be improved through MLD, which enables precise control of atomic and molecular arrangements to construct a wire network that achieves ""three-dimensional growth"". MLD facilitates dot-by-dot--o

  2. Comparison on the Contents of Cholic Acid in Natural Calculus Bovis and Calculus Bovis Artifactus Determined by Thin Layer Chromatography Scanning%薄层扫描法测定天然牛黄与人工牛黄胆酸含量比较

    Institute of Scientific and Technical Information of China (English)

    王志强; 刘海津

    2011-01-01

    Objective:To determine and compare the total contents of cholic acid in natural calculus bovis and calculus bovis artifactus in 6 product units. Methods: The silica G thin layer plate was used with isooctane - butyl acetate - glacial acetic acid - formic acid (8 : 4 : 2 : 1) as developing solvent, λs =380 nm,λR =650 nm,in the reflection of jagged scanning. Results:The content of cholic acid in calculus bovis artifactus was the same as that in natural calculus bovis. The content of free bile acid in calculus bovis artifactus was more than that in natural calculus bovis. Therefore, calculus bovis artifactus could be the substitute for natural calculus bovis within limits. Conclusion: Thin layer chromatography ( TLC ) scanning is a reliable method to determine the contents of cholic acid in natural calculus bovis and calculus bovis artifactus.%摘要:目的:测定天然牛黄与6个生产单位的人工牛黄中胆酸的含量总量比较。方法:硅胶G薄层板,异辛烷—醋酸丁酯—冰醋酸—甲酸(8∶4∶2∶1)为展开剂,λS= 380ntm,λR=650ntm,用反射法锯齿形扫描。结果:人工牛黄与天然牛黄中的胆酸成分相同,且人工牛黄中的游离胆汁酸比天然牛黄略高,在一定范围内,人工牛黄可替代天然牛黄。结论:薄层扫描法测定天然牛黄与人工牛黄中胆酸含量方法可靠。

  3. Thin film photovoltaic devices with a minimally conductive buffer layer

    Science.gov (United States)

    Barnes, Teresa M.; Burst, James

    2016-11-15

    A thin film photovoltaic device (100) with a tunable, minimally conductive buffer (128) layer is provided. The photovoltaic device (100) may include a back contact (150), a transparent front contact stack (120), and an absorber (140) positioned between the front contact stack (120) and the back contact (150). The front contact stack (120) may include a low resistivity transparent conductive oxide (TCO) layer (124) and a buffer layer (128) that is proximate to the absorber layer (140). The photovoltaic device (100) may also include a window layer (130) between the buffer layer (128) and the absorber (140). In some cases, the buffer layer (128) is minimally conductive, with its resistivity being tunable, and the buffer layer (128) may be formed as an alloy from a host oxide and a high-permittivity oxide. The high-permittivity oxide may further be chosen to have a bandgap greater than the host oxide.

  4. Chromatographic separation of inorganic ions on thin layers of titanium phosphate ion-exchanger

    Institute of Scientific and Technical Information of China (English)

    Vanik GHOULIPOUR; Moharram SAFARI

    2014-01-01

    The chromatographic behavior of 30 inorganic cations has been studied on thin layers of titanium phosphate ion-exchanger using several aqueous,organic and mixed mobile phases. The separation of one ion from several other ions and also ternary and binary separations have been developed. Some important analytical separations are reported. The effect of pH of the mobile phase on retention factor(Rf)values of the cations in the presence of complex-forming anion along with the separation power of the ion-exchanger were studied. This ion-exchanger exhibits high sorption capacity and varying selectivity towards metal ions and makes it a suitable stationary phase in thin layer chromatography.

  5. Chromatographic separation of inorganic ions on thin layers of titanium phosphate ion-exchanger.

    Science.gov (United States)

    Ghoulipour, Vanik; Safari, Moharram

    2014-12-01

    The chromatographic behavior of 30 inorganic cations has been studied on thin layers of titanium phosphate ion-exchanger using several aqueous, organic and mixed mobile phases. The separation of one ion from several other ions and also ternary and binary separations have been developed. Some important analytical separations are reported. The effect of pH of the mobile phase on retention factor (Rf) values of the cations in the presence of complex-forming anion along with the separation power of the ion-exchanger were studied. This ion-exchanger exhibits high sorption capacity and varying selectivity towards metal ions and makes it a suitable stationaiy phase in thin layer chromatography.

  6. Neuere Chromatographie

    Science.gov (United States)

    Hostettmann, K.

    1983-04-01

    Besides high-performance liquid chromatography (HPLC) which is now a well-established and currently used technique, several emerging methods for the isolation and separation of natural products are receiving considerable attention. Centrifugal thin-layer chromatography is a very rapid technique, but limited in resolution. Of special interest are the recently developed support-free liquid-liquid chromatography methods such as droplet counter-current chromatography (DCCC) and rotation locular counter-current chromatography (RLCC). This latter method was applied to the separation of the enantiomers of (±)-norephedrine.

  7. Epitaxy of layered semiconductor thin films

    Science.gov (United States)

    Brahim Otsmane, L.; Emery, J. Y.; Jouanne, M.; Balkanski, M.

    1993-03-01

    Epilayers of InSe on InSe(00.1) and GaSe(00.1) have been grown by the molecular beam epitaxy (MBE) technique. Raman spectroscopy was used for a characterization of the structure and crystallinity in InSe/InSe(00.1) (homoepitaxy) and InSe/GaSe(00.1) (heteroepitaxy). The Raman spectra of the InSe thin films are identical to those of polytype γ-InSe. An activation of the E(LO) mode at 211 cm -1 is observed in these films here. Scanning electron microscopy (SEM) is also used to investigate surfaces of these films.

  8. Identification of Triterpene Acids Including Oleanolic Acid and Ursolic Acid in Fructus chaenomelis by Thin-layer Chromatography%木瓜齐墩果酸和熊果酸等三萜酸类薄层色谱分离鉴别

    Institute of Scientific and Technical Information of China (English)

    程菁菁; 谢晓梅; 张圣龙; 葛晓郡; 黄丽丹

    2012-01-01

    目的 建立木瓜齐墩果酸、熊果酸等三萜酸薄层色谱分离鉴别方法.方法 将点于硅胶G板上的样品点浸入1%碘-二氯甲烷溶液中预处理,以环己烷-丙酮-乙酸乙酯-甲酸(9∶2∶1∶0.2)为展开剂.结果 木瓜中熊果酸、齐墩果酸以及3-O-乙酰熊果酸能够被很好地分离和检识.结论 薄层色谱法简便、可靠,使木瓜鉴别更具客观性和专属性.%Objective To establish efficient methods for identifying triterpene acids, including oleanolic acid and ursolic acid, in Fructus chaenomelis by thin-layer chromatography (TLC). Methods The drops of samples on the plate of silica gel G were preprocessed with methylene dichloride solution containing 1% iodine, and then developed with the developer consisting of cyclohexane-acetone-acetic ether - methanoic acid (9:2:1: 0. 2). Results Oleanolic acid, ursolic acid, and 3-O-acetyl ursolic acid in Fructus chaenomelis could be identified clearly. Conclusion TLC is simple and reliable, and it has specificity and objectivity for identifying Fructus chaenornelis.

  9. Atomically thin semiconducting layers and nanomembranes: a review

    Science.gov (United States)

    Dragoman, Mircea; Dragoman, Daniela; Tiginyanu, Ion

    2017-03-01

    This article reviews the main physical properties of atomically thin semiconductors and the electronic devices based on them. We start with graphene, describing its physical properties and growth methods, followed by a discussion of its electronic device applications. Then, transition metal dichalcogenides (TMDs) are analyzed as a prototype of atomically thin semiconductors, their physical properties, growth methods, and electronic devices are discussed in detail. Finally, non-layered semiconducting membranes with thicknesses ranging from a few nanometers to about 50 nm, and considered as counterparts of atomically thin semiconductors, are analyzed, and their applications presented.

  10. Ultra-thin Metal and Dielectric Layers for Nanophotonic Applications

    DEFF Research Database (Denmark)

    Shkondin, Evgeniy; Leandro, Lorenzo; Malureanu, Radu;

    2015-01-01

    In our talk we first give an overview of the various thin films used in the field of nanophotonics. Then we describe our own activity in fabrication and characterization of ultra-thin films of high quality. We particularly focus on uniform gold layers having thicknesses down to 6 nm fabricated by......-beam deposition on dielectric substrates and Al-oxides/Ti-oxides multilayers prepared by atomic layer deposition in high aspect ratio trenches. In the latter case we show more than 1:20 aspect ratio structures can be achieved....

  11. High-performance thin-layer chromatography linked with (bio)assays and mass spectrometry - a suited method for discovery and quantification of bioactive components? Exemplarily shown for turmeric and milk thistle extracts.

    Science.gov (United States)

    Taha, Mahmoud N; Krawinkel, Michael B; Morlock, Gertrud E

    2015-05-15

    Extraction parameters, chemical fingerprint, and the single compounds' activity levels were considered for the selection of active botanicals. For an initial survey, the total bioactivity (i.e., total reducing capacity, total flavonoids contents and free radical scavenging capacity) of 21 aqueous and 21 ethanolic plant extracts was investigated. Ethanolic extracts showed a higher yield and were further analyzed by HPTLC in detail to obtain fingerprints of single flavonoids and further bioactive components. Exemplarily shown for turmeric (Curcuma longa) and milk thistle (Silybum marianum), effect-directed analysis (EDA) was performed using three selected (bio)assays, the Aliivibrio fischeri bioassay, the Bacillus subtilis bioassay and the 2,2-diphenyl-1-picrylhydrazyl (DPPH*) assay. As a proof of principle, the bioactive components found in the extracts were confirmed by HPTLC-MS. Bioassays in combination with planar chromatography directly linked to the known, single effective compounds like curcumin and silibinin. However, also some unknown bioactive components were discovered and exemplarily characterized, which demonstrated the strength of this kind of EDA. HPTLC-UV/Vis/FLD-EDA-MS could become a useful tool for selection of active botanicals and for the activity profiling of the active ingredients therein. The flexibility in effect-directed detections allows a comprehensive survey of effective ingredients in samples. This streamlined methodology comprised a non-targeted, effect-directed screening first, followed by a highly targeted characterization of the discovered bioactive compounds. HPTLC-EDA-MS can also be recommended for bioactivity profiling of food on the food intake side, as not only effective phytochemicals, but also unknown bioactive degradation products during food processing or contamination products or residues or metabolites can be detected. Thus, an efficient survey on potential food intake effects on wellness could be obtained. Having performed

  12. Peculiarities of neutron waveguides with thin Gd layer

    CERN Document Server

    Khaydukov, Yu; Progliado, V; Ustinov, V; Nikitenko, Yu; Keller, T; Aksenov, V; Keimer, B

    2015-01-01

    Peculiarities of the formation of a neutron enhanced standing wave in the structure with a thin highly absorbing layer of gadolinium are considered in the article. An analogue of the poisoning effect well known in reactor physics was found. The effect is stronger for the Nb/Gd/Nb system. Despite of this effect, for a Nb/Gd bilayer and a Nb/Gd/Nb trilayer placed between Al2O3 substrate and Cu layer, it is shown theoretically and experimentally that one order of magnitude enhancement of neutron density is possible in the vicinity of the Gd layer. This enhancement makes it possible to study domain formation in the Gd layer under transition of the Nb layer(s) into the superconducting state (cryptoferromagnetic phase).

  13. ANTIREFLECTION MULTILAYER COATINGS WITH THIN METAL LAYERS

    OpenAIRE

    L. A. Gubanova

    2016-01-01

    The design of anti-reflective coatings for metal surfaces of Al, Ti, N,i Cr is proposed. The coatings have the form of alternating layers of dielectric/metal/dielectric with the number of cells up to15. The method of calculation of such coatings is proposed. We have calculated the coatings of the type [HfO2/Cr/HfO2]15, [ZrO2/Ti/Al2O3]15, [ZrO2/Cr/ZrO2]15. It is shown that the proposed interference coatings provide reduction of the residual reflectance of the metal several times (from 3.5 to 6...

  14. ANTIREFLECTION MULTILAYER COATINGS WITH THIN METAL LAYERS

    Directory of Open Access Journals (Sweden)

    L. A. Gubanova

    2016-03-01

    Full Text Available The design of anti-reflective coatings for metal surfaces of Al, Ti, N,i Cr is proposed. The coatings have the form of alternating layers of dielectric/metal/dielectric with the number of cells up to15. The method of calculation of such coatings is proposed. We have calculated the coatings of the type [HfO2/Cr/HfO2]15, [ZrO2/Ti/Al2O3]15, [ZrO2/Cr/ZrO2]15. It is shown that the proposed interference coatings provide reduction of the residual reflectance of the metal several times (from 3.5 to 6.0 in a wide spectral range (300-1000 nm. The proposed coatings can be recommended as anti-reflective coatings for energy saving solar systems and batteries, and photovoltaic cells.

  15. Spatial atomic layer deposition of zinc oxide thin films

    NARCIS (Netherlands)

    Illiberi, A.; Roozeboom, F.; Poodt, P.W.G.

    2012-01-01

    Zinc oxide thin films have been deposited at high growth rates (up to ~1 nm/s) by spatial atomic layer deposition technique at atmospheric pressure. Water has been used as oxidant for diethylzinc (DEZ) at deposition temperatures between 75 and 250 °C. The electrical, structural (crystallinity and mo

  16. Transparent conducting oxide layers for thin film silicon solar cells

    NARCIS (Netherlands)

    Rath, J.K.; Liu, Y.; de Jong, M.M.; de Wild, J.; Schuttauf, J.A.; Brinza, M.; Schropp, R.E.I.

    2009-01-01

    Texture etching of ZnO:1%Al layers using diluted HCl solution provides excellent TCOs with crater type surface features for the front contact of superstrate type of thin film silicon solar cells. The texture etched ZnO:Al definitely gives superior performance than Asahi SnO2:F TCO in case of nanocry

  17. Layered Organization in the Coastal Ocean: 4-D Assessment of Thin Layer Structure, Dynamics and Impacts

    Science.gov (United States)

    2008-01-01

    Donaghay, in press. Spatial characteristics of thin scattering layers observed by airborn LIDAR. ICES Journal of Marine Systems [in press, refereed...scattering layers observed by airborne LIDAR. ICES Journal of Marine Systems [in press, refereed]. Holliday, D.V., P.L. Donaghay, C.F. Greenlaw, J.M. Napp

  18. Thin layer joining by gas adsorption

    Science.gov (United States)

    Taga, Yasunori; Fukumura, Toshio

    2014-10-01

    Attempt has been made to join borosilicate glass and cycloolefin (COP) polymer film by using gas adsorption method. After corona plasma treat, COP was exposed to (3-glycidoxypropyl) trimethoxysilane (GPS) and glass to (3-aminopropyl) triethoxysilane (APS) both in air atmosphere, resulting in co-adsorption of water vapor in the atmosphere and organosilane gases. Surface characterization of plasma treated and gas adsorbed surfaces was carried out by X-ray photoelectron spectroscopy (XPS) using Mg Kα X-ray source. Joining was carried out by a roll laminator after contact of both surfaces at room temperature, followed by annealing at 130 °C for 10 min. Adhesion strength was evaluated by 180 degree peel test based on ASTM D-903 and durability was examined under the conditions of 60 °C and 95% RH. It was found that after plasma treatment, complex functional groups such as Csbnd H, Csbnd O, Cdbnd O, Osbnd Cdbnd O and CO3 were found on COP and Osbnd H on glass. Thickness of GPS gas adsorption layer on COP was evaluated by the XPS to be at least 1.1 nm by taking inelastic mean free path of Si2p photoelectron into consideration. Joining force was found to be more than 5 N/25 mm corresponding to almost equal to COP bulk tensile strength. In addition, durability of this adhesion strength remained unchanged over 2000 h even after exposure to the durability test conditions of 60 °C and 95% RH. The results can be explained in terms of formation of Hsbnd H hydrogen bonding and Sisbnd O covalent bonding via silanols will be made at the interface as a result of lamination and annealing processes. In conclusion, ultrathin joining method by gas adsorption was established by the formation of hydrogen and covalent bonds at the interface by low temperature reaction process.

  19. Laser powder coating by multi-thin-layer technics

    Science.gov (United States)

    Sepold, Gerd; Becker, Reinhard

    1990-10-01

    The laser beam is an interesting tool for production of thin surface layers. The energy input is locally limited thus leading to a snall heat loading of the substrate. The geometric dinensions of the coatings are small as compared to conventional thermal technics like surface melting and coating. In the following the multithin-layer technique is introduced. By this process coatings of small dimensions could be produced. Due to high processing speeds high cooling rates up to lO K/s are achieved by heat conduction into the substrate. This process results in fine microcrystalline structures of the deposit. Using NiCrBSi as coating material it will be shown how and to which extent different parameters influence structure and geometry of the coating. 2. MULTI-THIN-LAYER TECHNIQUE The multi-pass thin layer technique is in principle a powder feed process. Under an oblique angle a powder is blown by an inert gas stream into the laser beam. On their way to the surface the powder particles are partially heated. The surface itself is melted by the laser beam. So a good adherence is ensured between the molten surface and the impinging melting particles. This process can be repeated several times thus forming a coating by a multithinlayer technique see fig. 2. In principle the powder feed process is a well known " thick coating " process for conventional coatings like turbine blades dyes etc. /1/. In this however very small dimensions are desired which may be used for reasons of wear or corrosion resistance or for conductive or insolating layers in micro technics. In this work we investigated the influence of some processing parameters in order to achieve layers or traces of small geometries. 3. MULTIPLE THIN LAYER COATING OF NiCrBSi NiCrBSi had been used as a coating material to produce thin layers or traces. These alloys are hard and wear resistant materials which are usually applied by conventional powder spraying methods followed by arc- or flame-fusing of the sprayed layer

  20. Thin hybrid pixel assembly fabrication development with backside compensation layer

    Science.gov (United States)

    Bates, R.; Buttar, C.; McMullen, T.; Cunningham, L.; Ashby, J.; Doherty, F.; Pares, G.; Vignoud, L.; Kholti, B.; Vahanen, S.

    2017-02-01

    The ATLAS and CMS experiments will both replace their entire tracking systems for operation at the HL-LHC in 2026. This will include a significantly larger pixel systems, for example, for ATLAS approximately 15 m2. To keep the tracker material budget low it is crucial to minimize the mass of the pixel modules via thinning both the sensor and readout chip to about 150 μm each. The bump yield of thin module assemblies using solder based bump bonding can be problematic due to wafer bowing during solder reflow at high temperature. A new bump-bonding process using backside compensation on the readout chip to address the issue of low yield will be presented. The objective is to compensate dynamically the stress of the front side stack by adding a compensating layer to the backside of the wafer. A SiN and Al:Si stack has been chosen for the backside layer. The bow reducing effect of applying a backside compensation layer will be demonstrated using the FE-I4 wafer. The world's first results from assemblies produced from readout wafers thinned to 100 μm with a stress compensation layer are presented with bond yields close to 100% measured using the FE-I4 readout chip.

  1. SIMULTANEOUS ESTIMATION AND VALIDATION OF VARDENAFIL AND DAPOXETINE HYDROCHLORIDE IN PHARMACEUTICAL FORMULATION BY THIN LAYER CHROMATOGRAPHIC DENSITOMETRIC METHOD

    OpenAIRE

    Bhavin Chapla; Gunjan Amin; Ashutosh Pandya; Jagdish Kakadiya; Nehal Shah

    2012-01-01

    The present manuscript describes new, simple, accurate, and precise high performance thin layer chromatography method for the simultaneous determination of Vardenafil and Dapoxetine in combined tablet dosage form. Chromatographic separation of the drugs was performed on aluminium plates pre coated with silica gel 60 F254 as the stationary phase and the solvent system consisted of Chloroform: Methanol: Acetonitrile: Formic acid (4: 0.8: 4: 1 v/v/v/v). Densitometric evaluation of the separated ...

  2. Effect of pirfenidone delivered using layer-by-layer thin film on excisional wound healing.

    Science.gov (United States)

    Mandapalli, Praveen Kumar; Labala, Suman; Bojja, Jagadeesh; Venuganti, Venkata Vamsi Krishna

    2016-02-15

    The aim of this study was to evaluate the effect of a new anti-fibrotic agent, pirfenidone (PFD), delivered using polyelectrolyte multilayer films on excisional wound healing. Polyelectrolyte multilayer films were prepared by layer-by-layer (LbL) sequential adsorption of chitosan and sodium alginate. The UV-spectrophotometer, FTIR and differential scanning calorimeter were used to characterize the LbL thin films. The PFD was entrapped within the LbL thin films and its effect on excisional wound healing was studied in C57BL/6. The total protein, collagen content and TGF-β expression within the wound tissue were determined after application of PFD using LbL thin films, chitosan hydrogel and polyethylene glycol hydrogel. UV-spectrophotometer and FTIR studies showed a sequential adsorption of chitosan and alginate polymer layers to form LbL thin films. The thickness of LbL thin films with 15 bilayers was found to be 15 ± 2 μm. HPLC analysis showed a PFD loading efficiency of 1.0 ± 0.1mg in 1cm(2) area of LbL thin film. In vivo wound healing studies in C57BL/6 mice showed an accelerated (healing.

  3. Methacrylate-based monolithic layers for planar chromatography of polymers.

    Science.gov (United States)

    Maksimova, E F; Vlakh, E G; Tennikova, T B

    2011-04-29

    A series of macroporous monolithic methacrylate-based materials was synthesized by in situ free radical UV-initiated copolymerization of functional monomers, such as glycidyl methacrylate (GMA), butyl methacrylate (BuMA), 2-aminoethyl methacrylate (AEMA), 2-hydroxyethyl methacrylate (HEMA) and 2-cyanoethyl methacrylate (CEMA), with crosslinking agent, namely, ethylene glycol dimethacrylate (EDMA). The materials obtained were applied as the stationary phases in simple and robust technique - planar chromatography (PLC). The method of separation layer fabrication representing macroporous polymer monolith bound to the specially prepared glass surface was developed and optimized. The GMA-EDMA and BuMA-EDMA matrixes were successfully applied for the separation of low molecular weight compounds (the mixture of several dies), as well as poly(vinylpyrrolidone) and polystyrene homopolymers of different molecular weights using reversed-phase mechanism. The materials based on copolymers AEMA-HEMA-EDMA and CEMA-HEMA-EDMA were used for normal-phase PLC separation of 2,4-dinitrophenyl amino acids and polystyrene standards.

  4. Investigation of multi-layer thin films for energy storage.

    Energy Technology Data Exchange (ETDEWEB)

    Renk, Timothy Jerome; Monson, Todd

    2009-01-01

    We investigate here the feasibility of increasing the energy density of thin-film capacitors by construction of a multi-layer capacitor device through ablation and redeposition of the capacitor materials using a high-power pulsed ion beam. The deposition experiments were conducted on the RHEPP-1 facility at Sandia National Laboratories. The dielectric capacitor filler material was a composition of Lead-Lanthanum-Zirconium-Titanium oxide (PLZT). The energy storage can be increased by using material of intrinsically high dielectric constant, and constructing many thin layers of this material. For successful device construction, there are a number of challenging requirements including correct stoichiometric and crystallographic composition of the deposited PLZT. This report details some success in satisfying these requirements, even though the attempt at device manufacture was unsuccessful. The conclusion that 900 C temperatures are necessary to reconstitute the deposited PLZT has implications for future manufacturing capability.

  5. Thin-Layer Drying Characteristics and Modeling of Chinese Jujubes

    Directory of Open Access Journals (Sweden)

    Xiao-Kang Yi

    2012-01-01

    Full Text Available A mathematical modeling of thin-layer drying of jujubes in a convective dryer was established under controlled conditions of temperature and velocity. The drying process took place both in the accelerating rate and falling rate period. We observed that higher temperature reduced the drying time, indicating higher drying rates of jujubes. The experimental drying data of jujubes were used to fit ten different thin-layer models, then drying rate constants and coefficients of models tested were determined by nonlinear regression analysis using the Statistical Computer Program. As for all the drying models, the Weibull distribution model was superior and best predicted the experimental values. Therefore, this model can be used to facilitate dryer design and promote efficient dryer operation by simulation and optimization of the drying processes. The volumetric shrinkable coefficient of jujubes decreased as the drying air temperature increased.

  6. Transmittance jump in a thin aluminium layer during laser ablation

    Energy Technology Data Exchange (ETDEWEB)

    Bykovsky, N E; Senatsky, Yu V [P N Lebedev Physics Institute, Russian Academy of Sciences, Moscow (Russian Federation); Pershin, S M; Samokhin, A A [A M Prokhorov General Physics Institute, Russian Academy of Sciences, Moscow (Russian Federation)

    2016-02-28

    A jump in the transmittance (from ∼0.1% to ∼50% for ∼1 ns) of an optical gate on a Mylar film (a thin aluminium layer on a Lavsan substrate) irradiated by nanosecond (10{sup -7} – 10{sup -8} s) pulses of a neodymium laser with an intensity up to 0.1 GW cm{sup -2} has been recorded. The mechanism of a fast (10{sup -10} – 10{sup -11} s) increase in the transmittance of the aluminium layer upon its overheating (without boiling) to the metal – insulator phase-transition temperature is discussed. (interaction of laser radiation with matter. laser plasma)

  7. Numerical simulation of thin layer coffee drying by control volumes

    OpenAIRE

    CIRO-VELÁSQUEZ, HÉCTOR J.; ABUD-CANO, LUIS C.; PÉREZ-ALEGRÍA, LUIS. R.

    2011-01-01

    The thin layer drying model proposed by Sokhansanj and Bruce (1987) was implemented to model the drying process of parchment coffee beans. A computational model based on a control volume approach was developed to simulate the drying process of parchment coffee. A one dimensional transient analysis was implemented in the radial direction applied to a spherical coffee bean of equivalent radius. The results found that, even though the numerical value for the mass transfer coefficient is a small ...

  8. The collective motion of nematodes in a thin liquid layer

    CERN Document Server

    Gart, Sean; Jung, Sunghwan

    2010-01-01

    Many organisms live in confined fluidic environments such as the thin liquid layers on the skin of host organisms or in partially- saturated soil. We investigate the collective behaviour of nematodes in a thin liquid layer, which was first observed by Gray and Lissmann, [J. Exp. Biol. 41, 135 (1964)]. We show experimentally that nematodes confined by a thin liquid film come into contact and only separate again after some intervention. We attribute this collective motion to an attractive force between them arising from the surface tension of the layer and show that for nearby nematodes this force is typically stronger than the force that may be exerted by the nematodes' muscles. We believe this to be the first demonstration of the "Cheerios effect" acting on a living organism. However, we find that being grouped together does not significantly alter the body stroke and kinematic performance of the nematode: there are no statistically significant changes of the Strouhal number and the ratio of amplitude to wave...

  9. Spray Layer-by-Layer Assembled Clay Composite Thin Films as Selective Layers in Reverse Osmosis Membranes.

    Science.gov (United States)

    Kovacs, Jason R; Liu, Chaoyang; Hammond, Paula T

    2015-06-24

    Spray layer-by-layer assembled thin films containing laponite (LAP) clay exhibit effective salt barrier and water permeability properties when applied as selective layers in reverse osmosis (RO) membranes. Negatively charged LAP platelets were layered with poly(diallyldimethylammonium) (PDAC), poly(allylamine) (PAH), and poly(acrylic acid) (PAA) in bilayer and tetralayer film architectures to generate uniform films on the order of 100 nm thick that bridge a porous poly(ether sulfone) support to form novel RO membranes. Nanostructures were formed of clay layers intercalated in a polymeric matrix that introduced size-exclusion transport mechanisms into the selective layer. Thermal cross-linking of the polymeric matrix was used to increase the mechanical stability of the films and improve salt rejection by constraining swelling during operation. Maximum salt rejection of 89% was observed for the tetralayer film architecture, with an order of magnitude increase in water permeability compared to commercially available TFC-HR membranes. These clay composite thin films could serve as a high-flux alternative to current polymeric RO membranes for wastewater and brackish water treatment as well as potentially for forward osmosis applications. In general, we illustrate that by investigating the composite systems accessed using alternating layer-by-layer assembly in conjunction with complementary covalent cross-linking, it is possible to design thin film membranes with tunable transport properties for water purification applications.

  10. Chemometrics in Fingerprinting by Means of Thin Layer Chromatography

    Directory of Open Access Journals (Sweden)

    Łukasz Komsta

    2012-01-01

    Full Text Available The paper is written as an introductory review, presenting summary of current knowledge about chemometric fingerprinting in the context of TLC, due to a rather small interest in the literature about joining TLC and chemometrics. The paper shortly covers the most important aspects of the chemometric fingerprinting in general, creating the TLC fingerprints, denoising, baseline removal, warping/registering, and chemometric processing itself. References being good candidates as a starting point are given for each topic and processing step.

  11. Analysis of Impurities in Composition B by Thin Layer Chromatography

    Science.gov (United States)

    1978-04-01

    tube with a stirring rod to manimize the entrapment of impurities ir. the solid mass. The mixture was centrifuged for 3 to Z4 minutes to separate the...flask. The washing was repeated twice. To prevent scattering in the spectrophotometric recording. care %as exercised to as- sure that no solid material...corner of the TLC sheet 3.3 cm from each edge. Care was taken to avoid sampling of solid residue into the syringe. The syringe was clamped on a stand

  12. Infrared analysis of thin layers by attenuated total reflection spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Rochat, N.; Chabli, A.; Bertin, F.; Vergnaud, C.; Mur, P.; Petitdidier, S.; Besson, P

    2003-09-15

    Interests in infrared spectroscopy (IRS) have been stimulated by the increasing need for non-destructive surface characterization providing structural and chemical informations about the new materials used in microelectronic devices. Standard infrared spectroscopy of thin layers is limited because of its lack of sensitivity. The use of optical configurations such as the attenuated total reflection (ATR) allows to characterize nanometric layers. This paper will present the results of a study conducted for a better understanding of the capabilities and limitations of this technique. A theoretical analysis based on a perturbation method is used to elucidate the results of ATR measurements performed on silicon oxide layers of different thickness on silicon substrates. This analysis shows that the absorbance ATR spectrum in p polarization is the image of the layer energy loss function, under specific conditions. The exact ATR spectrum simulation using a matrix formalism showed that the straightforward interpretation in terms of the layer dielectric function is limited to a very narrow layer thickness range. The fitting process of the ATR spectrum is evaluated for the interpretation of experimental spectra obtained for the growth of chemical silicon oxide layers.

  13. Thin layer chromatographic separation of cobalt from nickel on impregnated silica gel layers:quantitative determination by digital image analysis%Thin layer chromatographic separation of cobalt from nickel on impregnated silica gel layers: quantitative determination by digital image analysis

    Institute of Scientific and Technical Information of China (English)

    P A MOHAMED NAJAR; R G SONALI; M T NIMJE; K V RAMANA RAO

    2012-01-01

    Thin layer chromatography (TLC) of cobalt and nickel has been performed on silica gel layers induced with alkali mediated cellulose extract.A novel combination of 10% aqueous solutions of Tween-20 and potassium thiocyanate in 1∶ 1 (v/v) was identified as the best mobile phase for the selective separation of Co2+ from Ni2+ on the impregnated Silica Gel G layers.The chromatographic characteristics of the cations were studied and the limits of detection as well as the limits of quantification for Co2+ and Ni2+ were determined.The quantitative estimation of the cations was achieved from the digital image analysis of respective chromatograms.The proposed quantitative method was successfully applied with 0-0.50% error for the determination of Co2+ from Ni2+ in spiked samples of bauxite,soil and rock containing common cations such as Al3+,Fe2+,Ti4+,Zn2+,Mn2+,Cu2+,Cr6+,Mg2+ etc.under the optimized chromatographic conditions.

  14. Fracture Patterns Induced by Desiccation in a Thin Layer

    CERN Document Server

    Kitsunezaki, S

    1999-01-01

    We study a theoretical model of mud cracks, that is, the fracture patterns resulting from the contraction with drying in a thin layer of a mixture of granules and water. In this model, we consider the slip on the bottom of this layer and the relaxation of the elastic field that represents deformation of the layer. Analysis of the one-dimensional model gives results for the crack size that are consistent with experiments. We propose an analytical method of estimation for the growth velocity of a simple straight crack to explain the very slow propagation observed in actual experiments. Numerical simulations reveal the dependence of qualitative nature of the formation of crack patterns on material properties.

  15. Reflection of infrared radiation from thin aluminium layers

    CERN Document Server

    Calatroni, Sergio

    2001-01-01

    The thermal shielding of the LHC magnets cryostats will make use of Multi-Layer Insulation. This is a sandwich of several Mylar (polyester) foils 6 µm thick coated with a thin film of aluminium, having a thickness of some 30 nm. The thickness of the aluminium film must be kept at a minimum to minimise lateral thermal conduction. The outer layer of this sandwich stays at a temperature of 20 K or below, and receives IR radiation from surfaces at 77 K (wavelength of 37.6 µm at the peak of blackbody radiation), which should be reflected with the highest efficiency. The minimum thickness for the aluminium layer to avoid transmission of the radiation can be calculated by making use of the skin effect theory, taking into account the changes in electrical properties that are due to the extremely low thickness of the film.

  16. Properties of Ultra-Thin Hafnium Oxide and Interfacial Layer Deposited by Atomic Layer Deposition

    Institute of Scientific and Technical Information of China (English)

    Taeho Lee; Young-Bae Kim; Kyung-Il Hong; Duck-Kyun Choi; Jinho Ahn

    2004-01-01

    Ultra-thin hafnium-oxide gate dielectric films deposited by atomic layer deposition technique using HfCl4 and H2O precursor on a hydrogen-terminated Si substrate were investigated. X-ray photoelectron spectroscopy indicates that the interface layer is Hf-silicate rather than phase separated Hf-silicide and silicon oxide structure. The Hf-silicate interfacial layer partially changes into SiOx after high temperature annealing, resulting in a complex HfO2-silicate-SiOx dielectric structure. Electrical measurements confirms that HfO2 on Si is stable up to 700 ℃ for 30 s under N2 ambient.

  17. Effects of different wetting layers on the growth of smooth ultra-thin silver thin films

    Science.gov (United States)

    Ni, Chuan; Shah, Piyush; Sarangan, Andrew M.

    2014-09-01

    Ultrathin silver films (thickness below 10 nm) are of great interest as optical coatings on windows and plasmonic devices. However, producing these films has been a continuing challenge because of their tendency to form clusters or islands rather than smooth contiguous thin films. In this work we have studied the effect of Cu, Ge and ZnS as wetting layers (1.0 nm) to achieve ultrasmooth thin silver films. The silver films (5 nm) were grown by RF sputter deposition on silicon and glass substrates using a few monolayers of the different wetting materials. SEM imaging was used to characterize the surface properties such as island formation and roughness. Also the optical properties were measured to identify the optical impact of the different wetting layers. Finally, a multi-layer silver based structure is designed and fabricated, and its performance is evaluated. The comparison between the samples with different wetting layers show that the designs with wetting layers which have similar optical properties to silver produce the best overall performance. In the absence of a wetting layer, the measured optical spectra show a significant departure from the model predictions, which we attribute primarily to the formation of clusters.

  18. Two approaches for enhancing the hydrogenation properties of palladium: Metal nanoparticle and thin film over layers

    Indian Academy of Sciences (India)

    Manika Khanuja; B R Mehta; S M Shivaprasad

    2008-11-01

    In the present study, two approaches have been used for enhancing the hydrogenation properties of Pd. In the first approach, metal thin film (Cu, Ag) has been deposited over Pd and hydrogenation properties of bimetal layer Cu (thin film)/Pd(thin film) and Ag(thin film)/Pd(thin film) have been studied. In the second approach, Ag metal nanoparticles have been deposited over Pd and hydrogenation properties of Ag (nanoparticle)/Pd (thin film) have been studied and compared with Ag(thin film)/Pd(thin film) bimetal layer system. The observed hydrogen sensing response is stable and reversible over a number of hydrogen loading and deloading cycles in both bimetallic systems. Alloying between Ag and Pd is suppressed in case of Ag(nanoparticle)/Pd(thin film) bimetallic layer on annealing as compared to Ag (thin film)/Pd(thin film).

  19. Ion Exchange and Thin Layer Chromatographic Separation and Identification of Amino Acids in a Mixture: An Experiment for General Chemistry and Biotechnology Laboratories

    Science.gov (United States)

    Brunauer, Linda S.; Caslavka, Katelyn E.; Van Groningen, Karinne

    2014-01-01

    A multiday laboratory exercise is described that is suitable for first-year undergraduate chemistry, biochemistry, or biotechnology students. Students gain experience in performing chromatographic separations of biomolecules, in both a column and thin layer chromatography (TLC) format. Students chromatographically separate amino acids (AA) in an…

  20. A contribution to the determination of aflatoxin B1, quinine hydrochloride and L(+)-ascorbic acid in foodstuffs by quantitative in situ thin-layer chromatographic analysis

    NARCIS (Netherlands)

    Beljaars, P.R.

    1974-01-01

    The application of quantitative thin-layer chromatography (TLC) involving in situ spectrodensitometric measurements with a flying-spot densitometer is described in this study for the analysis of aflatoxin B 1 , quinine hydrochloride and L(+)-ascorbic acid (vitamin C

  1. Comparação das técnicas de cromatografia em camada delgada e ELISA na quantificação de aflatoxinas em amostras de milho Comparison of thin layer chromatography and ELISA techniques in the quantification of aflatoxins in corn samples

    Directory of Open Access Journals (Sweden)

    Marize Silva OLIVEIRA

    2000-12-01

    Full Text Available A comparação das técnicas de Enzyme Linked Immunosorbent Assay (ELISA e cromatografia em camada delgada (CCD por quantificação visual e densitométrica foi utilizada na determinação de aflatoxina total, em amostras de milho naturalmente contaminadas. Os teores de aflatoxina total encontrados pelas técnicas de CCD e ELISA, apresentaram maior freqüência na faixa de 0-30 mig/kg e acima de 300 mig/kg. Os resultados das amostras apresentaram coeficiente de variação concentrados abaixo de 20, 30 e 40% para a técnica de ELISA e CCD com quantificação densitométrica e visual, respectivamente. Os coeficientes de correlação foram altamente significativos para as relações entre as quantificações visual e densitométrica (r = 0,9219; t = 26,36; p Two methods, enzyme linked immunosorbent assay (ELISA and thin layer chromatography (TLC by visual and densitometric, were compared for determination of aflatoxins in corn samples. The highest incidence of total aflatoxin detected by those methods were ranged from 0-30 mug/kg and above 300 mug/kg. For aflatoxins B2, G1, G2 the levels were ranged from 0-30mug/kg. The samples results showed variation coefficient below of 20, 30 and 40% for ELISA and CCD with densitometric and visual quantification, respectively. The correlation coefficients were highly significative for the relation between visual quantification and densitometric (r = 0,9219; t = 28,36; p<0,001, ELISA and visual quantification (r =0,8277; t = 17,58; p< 0,001, ELISA e quantification densitometric (r = 0,7373; t=13,01; p< 0,001, in the total aflatoxin detemination of all corn samples. confirming the equivalence of the studied methods.

  2. Thin-Layer Solutions of the Helmholtz and Related Equations

    KAUST Repository

    Ockendon, J. R.

    2012-01-01

    This paper concerns a certain class of two-dimensional solutions to four generic partial differential equations-the Helmholtz, modified Helmholtz, and convection-diffusion equations, and the heat conduction equation in the frequency domain-and the connections between these equations for this particular class of solutions.S pecifically, we consider thin-layer solutions, valid in narrow regions across which there is rapid variation, in the singularly perturbed limit as the coefficient of the Laplacian tends to zero.F or the wellstudied Helmholtz equation, this is the high-frequency limit and the solutions in question underpin the conventional ray theory/WKB approach in that they provide descriptions valid in some of the regions where these classical techniques fail.E xamples are caustics, shadow boundaries, whispering gallery, and creeping waves and focusing and bouncing ball modes.It transpires that virtually all such thin-layer models reduce to a class of generalized parabolic wave equations, of which the heat conduction equation is a special case. Moreover, in most situations, we will find that the appropriate parabolic wave equation solutions can be derived as limits of exact solutions of the Helmholtz equation.W e also show how reasonably well-understood thin-layer phenomena associated with any one of the four generic equations may translate into less well-known effects associated with the others.In addition, our considerations also shed some light on the relationship between the methods of matched asymptotic, WKB, and multiple-scales expansions. © 2012 Society for Industrial and Applied Mathematics.

  3. Active Constrained Layer Damping of Thin Cylindrical Shells

    Science.gov (United States)

    RAY, M. C.; OH, J.; BAZ, A.

    2001-03-01

    The effectiveness of the active constrained layer damping (ACLD) treatments in enhancing the damping characteristics of thin cylindrical shells is presented. A finite element model (FEM) is developed to describe the dynamic interaction between the shells and the ACLD treatments. Experiments are performed to verify the numerical predictions. The obtained results suggest the potential of the ACLD treatments in controlling the vibration of cylindrical shells which constitute the major building block of many critical structures such as cabins of aircrafts, hulls of submarines and bodies of rockets and missiles.

  4. Obtaining shape memory alloy thin layer using PLD technique

    Directory of Open Access Journals (Sweden)

    Cimpoeşu N.

    2014-01-01

    Full Text Available Copper-based shape memory alloy (SMA was obtained through a classic melting method. The material was analyzed in heat treated and deformed states using scanning electrons microscopy (SEM, dilatometry (DIL, differential scanning calorimetry (DSC, dynamic mechanical analyzer (DMA and energy dispersive X-ray analyze (EDAX to establish the material microstructure, memory properties like martensitic transformation domain and rate or damping capacity. The material exhibits a good shape memory effect and high internal friction and it is proposed as target in a pulsed laser deposition (PLD process for obtaining thin films. The deposition process is described in this paper through presented experimental results on the layer.

  5. Electrochemical Thin Layers in Nanostructures for Energy Storage.

    Science.gov (United States)

    Noked, Malachi; Liu, Chanyuan; Hu, Junkai; Gregorczyk, Keith; Rubloff, Gary W; Lee, Sang Bok

    2016-10-18

    Conventional electrical energy storage (EES) electrodes, such as rechargeable batteries, are mostly based on composites of monolithic micrometer sized particles bound together with polymeric and conductive carbon additives and binders. The kinetic limitations of these monolithic chunks of material are inherently linked to their electrical properties, the kinetics of ion insertion through their interface and ion migration in and through the composite phase. Redox chemistry of nanostructured materials in EES systems offer vast gains in power and energy. Furthermore, due to their thin nature, ion and electron transport is dramatically increased, especially when thin heterogeneous conducting layers are employed synergistically. However, since the stability of the electrode material is dictated by the nature of the electrochemical reaction and the accompanying volumetric and interfacial changes from the perspective of overall system lifetime, research with nanostructured materials has shown often indefinite conclusions: in some cases, an increase in unwanted side-reactions due to the high surface area (bad). In other cases, results have shown significantly better handling of mechanical stress that results from lithiation/delithiation (good). Despite these mixed results, scientifically informed design of thin electrode materials, with carefully chosen architectures, is considered a promising route to address many limitations witnessed in EES systems by reducing and protecting electrodes from parasitic reactions, accommodating mechanical stress due to volumetric changes from electrochemical reactions, and optimizing charge carrier mobilities from both the "ionic" and "electronic" points of view. Furthermore, precise nanoscale control over the electrode structure can enable accurate measurement through advanced spectroscopy and microscopy techniques. This Account summarizes recent findings related to thin electrode materials synthesized by atomic layer deposition (ALD) and

  6. Impactfactors and optimization method on the separation of active components in licorice by micellar thin layer chromatography%胶束薄层色谱分离甘草活性成分的影响因素及优化方法

    Institute of Scientific and Technical Information of China (English)

    崔淑芬; 林焕冰; 王小如

    2012-01-01

    目的:为甘草的胶束薄层色谱指纹图谱寻找最优胶束流动相.方法:首先采用单因子法,寻找影响甘草胶束薄层色谱的影响因素,在此基础上,采用控制加权可变步长单纯形优化法进行甘草胶束薄层色谱指纹图谱的流动相优化.结果:对甘草的胶束薄层色谱分离条件(表面活性剂的种类和含量、醇和酸改性剂的影响等)进行了实验,表明纯胶束薄层色谱的柱效较低,加入醇和酸类改性剂后柱效有明显提高.通过对改性胶束的进一步优化(控制加权可变步长单纯形优化法),得到优化的甘草改性胶束展开剂组成为:0.23 mol·L-1的SDS+ 16%(v/v)正丁醇+11%(v/v)甲酸.本研究对胶束薄层色谱的一些分离机理亦进行了探讨.结论:胶束薄层色谱的表面活性剂和各添加剂间存在交互作用,需采用合适的优化方法,才能达到分离中药材复杂活性成分群的目的.%Objective: To seek the best mobile phase of micellar thin - layer chromatography ( MTLC) of licorice fingerprint. Method: Single impact factor of mobile phase in licorice MTLC fingerprint was tested individually and controlled weighted centroid simplex method was used finally to optimize the mobile phase of licorice MTLC fingerprint. Results: The selectivity of micellar TLC was studied for the separation of active components in licorice under various operation variables including concentrations of surfactant and co - surfactant, surfactant type, addition of acid modifier,et al. The results show that the low chromatography efficiency of micellar TLC could be improved by the addition of alcohol and acid modifier. Using controlled weighted centroid simplex method,optimization micellar TLC developing system of licorice was achieved which consists of 0. 23 mol · L-1 SDS,16% (v/v)n -butanol and 11% (v/v)methyl acid. In addition,the separation mechanism of micellar TLC was also discussed. Conclusion: he appropriate optimization method should

  7. Process for the production of thin layers, preferably for a photovoltaic cell

    NARCIS (Netherlands)

    Nanu, M.; Meester, B.; Goossens, A.; Schoonman, J.

    2006-01-01

    The invention is directed to a process for the production of a thin layer, preferably for a photovoltaic cell, which cell has at least a first contact layer, a p-type semiconductor layer, an n-type semiconductor layer, or a combined p-type/n-type semiconductor layer, and a second contact layer, said

  8. Light scattering of thin azobenzene side-chain polyester layers

    DEFF Research Database (Denmark)

    Kerekes, Á.; Lörincz, E.; Ramanujam, P.S.;

    2002-01-01

    Light scattering properties of liquid crystalline and amorphous azobenzene side-chain polyester layers used for optical data storage were examined by means of transmissive scatterometry. Comparative experiments show that the amorphous polyester has significantly lower light scattering...... characteristics than the liquid crystalline polyester. The amorphous samples have negligible polarization part orthogonal to the incident beam. the liquid crystalline samples have relative high orthogonal polarization part in light scattering, The light scattering results can be used to give a lower limit...... for the domain size in thin liquid crystalline polyester layers being responsible for the dominant light scattering. The characteristic domain Sizes obtained from the Fourier transformation of polarization microscopic Pictures confirm these values....

  9. Thin layer chromatographic analysis of some common over the counter (OTC cough–cold preparations

    Directory of Open Access Journals (Sweden)

    Manpreet Kaur Chahal

    2016-12-01

    Full Text Available In the present study, potential utility of thin layer chromatography to differentiate some common OTC cough–cold preparations was evaluated. Twenty solvent systems were examined from which a solvent systems A comprising methanol:ammonia in the ratio of 100:1.5 (v/v and B comprising chloroform:methanol in the ratio of 90:10 (v/v were found to be most suitable as it showed a high degree of separation of different components of these preparations. It was also found that iodine fuming technique is the best visualizing method for examining the TLC chromatograms of these drug samples prior to subsequent instrumental analysis.

  10. Selective separation and determination of isoproterenol on thin layers of bismuth silicate ion-exchanger

    Institute of Scientific and Technical Information of China (English)

    Vanik GHOULIPOUR; Zahra HASSANKHANI-MAJD

    2015-01-01

    A simple and sensitive method for the separation and determination of isoproterenol from other do-ping drugs has been developed on thin layers of bismuth silicate,a synthetic inorganic ion exchanger as adsor-bent in thin layer chromatography(TLC). A mixture of methanol and 0. 1 mol/L formic acid(3:7,v/v)was employed as the mobile phase. The development time was 32 min. The quantitative measurement were per-formed with a Camag TLC Scanner-3 at wavelength(λ)of 410 nm. The isoproterenol recovery in this procedure was 98. 9%. The linear correlation coefficient was greater than 0. 987 1 and the relative standard deviation (RSD)was less than 0.94. The limit of detection(LOD)and limit of quantification(LOQ)were 7.7×10-7 mol/L and 3. 85 ×10-6 mol/L,respectively. This method has been applied in the determination of isoproterenol in dosage forms and in biological fluids.

  11. Selective separation and determination of isoproterenol on thin layers of bismuth silicate ion-exchanger.

    Science.gov (United States)

    Ghoulipour Vanik; Hassankhani-Majd Zahra

    2015-06-01

    A simple and sensitive method for the separation and determination of isoproterenol from other doping drugs has been developed on thin layers of bismuth silicate, a synthetic inorganic ion exchanger as adsorbent in thin layer chromatography (TLC). A mixture of methanol and 0.1 mol/L formic acid (3:7, v/v) was employed as the mobile phase. The development time was 32 min. The quantitative measurement were performed with a Camag TLC Scanner-3 at wavelength (λ) of 410 nm. The isoproterenol recovery in this procedure was 98.9%. The linear correlation coefficient was greater than 0. 987 1 and the relative standard deviation (RSD) was less than 0.94. The limit of detection (LOD) and limit of quantification ( LOQ) were 7.7 x 10(-7) mol/L and 3.85 x 10(-6) mol/L, respectively. This method has been applied in the determination of isoproterenol in dosage forms and in biological fluids.

  12. Structural properties of dopping metallic impurities on CdS thin layers

    Directory of Open Access Journals (Sweden)

    S. Ghasemzadeh

    2016-12-01

    Full Text Available (Cu,Zn-dopped CdS thin layers were deposited on glass substrates by chemical bath deposition technique. The effects of the doping on the structural properties of CdS thin layers were studied by SEM and EDAX analysis. Hetero junction layers were produced with different nano structures and different fraction of voids and metallic ions.

  13. Structural properties of dopping metallic impurities on CdS thin layers

    OpenAIRE

    S. Ghasemzadeh; H. kangarlou

    2016-01-01

    (Cu,Zn)-dopped CdS thin layers were deposited on glass substrates by chemical bath deposition technique. The effects of the doping on the structural properties of CdS thin layers were studied by SEM and EDAX analysis. Hetero junction layers were produced with different nano structures and different fraction of voids and metallic ions.

  14. Polymer Thin Films and Interfaces; a Layer-by-Layer Approach

    Science.gov (United States)

    White, Ronald; Lipson, Jane

    2013-03-01

    In this talk we discuss new ways to model polymer films and interfaces, including properties such as density and concentration gradients, interfacial tension, and surface enrichment. We build on recent work where we developed a very simple equation of state approach for polymer thin films, and successfully applied it to determine thermodynamic properties and even to make predictions for the thickness-dependent depression of the thin film glass transition temperature. In that very simplified mean field model, the film properties across the entire interface region were treated as a ``whole sample'' average. Here, we take the next step, and develop a layer-by-layer equation of state model wherein details of the interface region are captured by allowing properties to vary from one discretized layer (within which properties are uniform) to the next. The model can be solved by imposing hydrostatic equilibrium in each layer, which then leads to predictions for the corresponding density gradient and other key interface properties. Work supported by the National Science Foundation.

  15. Structural properties of produced CuO/NiO/glass thin layers Produced by chemical method

    Directory of Open Access Journals (Sweden)

    A. Ramezani

    2016-12-01

    Full Text Available Nickel Oxide and Copper oxide on Nickel Oxide thin layers were produced by chemical bath deposition method. There nano structures were investigated by SEM and EDAX analysis. By producing CuO/NiO/glass sandwich layers nano structure of NiO/glass layer changed and fraction of voids decreases. In sandwich layer physical property of outer layer was dominant

  16. Redox cycling for electrolysis of pure water in a thin layer cell

    OpenAIRE

    李, 春艳

    2013-01-01

    The redox cycling can achieve in thin layer cell because products of electrode reactions diffuse in opposite directions across the thin layer to the electrodes where they can react again. This redox cycling can enhance the current, and hence improve the sensitivity and selectivity. The redox cycling can make the current be under steady state in thin layer electrolysis. The aim of this thesis is to get controlling factors of redox cycling in electrolysis of water. the factors include not only ...

  17. Underpotential deposition-mediated layer-by-layer growth of thin films

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jia Xu; Adzic, Radoslav R.

    2015-05-19

    A method of depositing contiguous, conformal submonolayer-to-multilayer thin films with atomic-level control is described. The process involves the use of underpotential deposition of a first element to mediate the growth of a second material by overpotential deposition. Deposition occurs between a potential positive to the bulk deposition potential for the mediating element where a full monolayer of mediating element forms, and a potential which is less than, or only slightly greater than, the bulk deposition potential of the material to be deposited. By cycling the applied voltage between the bulk deposition potential for the mediating element and the material to be deposited, repeated desorption/adsorption of the mediating element during each potential cycle can be used to precisely control film growth on a layer-by-layer basis. This process is especially suitable for the formation of a catalytically active layer on core-shell particles for use in energy conversion devices such as fuel cells.

  18. Measurement of a thin layers thickness using independent component analysis of ground penetrating radar data

    Institute of Scientific and Technical Information of China (English)

    LI Xiang-tang; ZHANG Xiao-ning; WANG Duan-yi

    2008-01-01

    To detect overlapped echoes due to the thin pavement layers, we present a thickness measurement approach for the very thin layer of pavement structures. The term "thin" is relative to the incident wavelength or pulse. By means of independent component analysis of noisy signals received by a single radar sensor, the over-lapped echoes can be successfully separated. Once the echoes from the top and bottom side of a thin layer have been separated, the time delay and the layer thickness determination follow immediately. Results of the simula-tion and real data re fy the feasibility of the presented method.

  19. Crystallinity Improvement of ZnO Thin Film on Different Buffer Layers Grown by MBE

    OpenAIRE

    2012-01-01

    The material and optical properties of ZnO thin film samples grown on different buffer layers on sapphire substrates through a two-step temperature variation growth by molecular beam epitaxy were investigated. The thin buffer layer between the ZnO layer and the sapphire substrate decreased the lattice mismatch to achieve higher quality ZnO thin film growth. A GaN buffer layer slightly increased the quality of the ZnO thin film, but the threading dislocations still stretched along the c-axis o...

  20. Tensile strength of thin resin composite layers as a function of layer thickness.

    Science.gov (United States)

    Alster, D; Feilzer, A J; De Gee, A J; Davidson, C L

    1995-11-01

    As a rule, cast restorations do not allow for free curing contraction of the resin composite luting cement. In a rigid situation, the resulting contraction stress is inversely proportional to the resin layer thickness. Adhesive technology has demonstrated, however, that thin joints may be considerably stronger than thicker ones. To investigate the effects of layer thickness and contraction stress on the tensile strength of resin composite joints, we cured cylindrical samples of a chemically initiated resin composite (Clearfil F2) in restrained conditions and subsequently loaded them in tension. The samples had a diameter of 5.35 mm and thicknesses of 50, 100, 200, 300, 400, 500, 600, and 700 microns, 1.4 mm, or 2.7 mm. None of the samples fractured due to contraction stress prior to tensile loading. Tensile strength decreased gradually from 62 +/- 2 MPa for the 50-microns layer to 31 +/- 4 MPa for the 2.7-mm layer. The failures were exclusively cohesive in resin for layers between 50 and 400 microns thick. Between 500 and 700 microns, the failures were cohesive or mixed adhesive/cohesive, while the 1.4- and 2.7-mm layers always failed in a mixed adhesive/cohesive mode. For the resin composite tested, the contraction stress did not endanger the cohesive strength. It was concluded that if adhesion to tooth structure were improved, thinner adhesive joints might enhance the clinical success of luted restorations.

  1. The Untapped Potential Of Plant Thin Cell Layers

    Directory of Open Access Journals (Sweden)

    Teixeira da Silva Jaime

    2015-12-01

    Full Text Available Thin cell layers (TCLs, which contain a small number of cells or tissues, are explants excised from different organs (stems, leaves, roots, inflorescences, flowers, cotyledons, hypocotyls/epicotyls, and embryos. After almost 45 years of research, this culture system has been used for several monocotyledonous and dicotyledonous plants of commercial importance, and for model plants. The limited amount of cells in a TCL is of paramount importance because marker molecules/genes of differentiation can be easily localized in situ in the target/responsive cells. Thus, the use of TCLs has allowed, and continues to allow, for the expansion of knowledge in plant research in a practical and applied manner into the fields of tissue culture and micropropagation, cell and organ genetics, molecular biology, biochemistry, and development. Starting from a brief historical background, the actual and potential uses of the TCL system are briefly reviewed.

  2. Thin layer modelling of Gelidium sesquipedale solar drying process

    Energy Technology Data Exchange (ETDEWEB)

    Ait Mohamed, L. [Laboratoire d' Energie Solaire et des Plantes Aromatiques et Medicinales, Ecole Normale Superieure, BP 2400, Marrakech (Morocco); Faculte des Sciences Semlalia, BP 2390, Marrakech (Morocco); Ethmane Kane, C.S. [Faculte des Sciences de Tetouan, BP 2121, Tetouan (Morocco); Kouhila, M.; Jamali, A. [Laboratoire d' Energie Solaire et des Plantes Aromatiques et Medicinales, Ecole Normale Superieure, BP 2400, Marrakech (Morocco); Mahrouz, M. [Faculte des Sciences Semlalia, BP 2390, Marrakech (Morocco); Kechaou, N. [Ecole Nationale d' Ingenieurs de Sfax, BPW 3038 (Tunisia)

    2008-05-15

    The effect of air temperature and air flow rate on the drying kinetics of Gelidium sesquipedale was investigated in convective solar drying. Drying was conducted at 40, 50 and 60 C. The relative humidity was varied from 50% to 57%, and the drying air flow rate was varied from 0.0277 to 0.0833 m{sup 3}/s. The expression for the drying rate equation is determined empirically from the characteristic drying curve. Thirteen mathematical models of thin layer drying are selected in order to estimate the suitable model for describing the drying curves. The two term model gives the best prediction of the drying curves and satisfactorily describes the drying characteristics of G. sesquipedale with a correlation coefficient R of 0.9999 and chi-square ({chi}{sup 2}) of 3.381 x 10{sup -6}. (author)

  3. KINETICS OF THIN LAYER DRYING OF POULTRY MANURE

    Directory of Open Access Journals (Sweden)

    A. E. Ghaly

    2012-01-01

    Full Text Available The poultry industry is one of the largest and fastest growing sectors of livestock production in the world. The estimated 2010 world flock was over 18 billion birds with a yearly manure output of 22 million tonnes. Storage and disposal of raw poultry manure has become an environmental problem because of the associated air, water and soil pollution. Environmental and health problems such as odor and pathogens that may arise during and after land application of raw manure can be eliminated by drying. Dried manure can be utilized as a soil conditioner to improve soil tilth and reduce the problems associated with soil compaction and as a feed for ruminants because of its high nitrogen content. The aim of this study was to investigate the kinetics of thin layer drying of poultry manure and evaluate the effects of drying with heated air on the chemical and biological properties of manure. The effects of temperature and depth of manure layer were evaluated. The profile of the moisture content of poultry manure followed an exponential decay curve. The moisture decay constant was affected by the drying temperature and the depth of the manure layer. At the three temperature levels studied, the time required to dry poultry manure in 1 cm-deep layer was the least, followed by 2 and 3 cm-deep layers, respectively. The diffusion coefficient increased with both temperature and depth of drying layer, but did not show a linear increase with either variable. The optimum depth for drying manure (at which the highest drying effectiveness occurred was 3 cm. Drying manure at 40-60°C resulted in the loss of 44-55% of the total Kjeldahl nitrogen, with losses increasing with both the temperature and depth of manure. The pH of the manure decreased from the initial value of 8.4 before drying to about 6.6 after drying. The odor analysis indicated that dried poultry manure did not have an offensive odor. Drying achieved 65.3 and 69.3% reductions in odor intensity and

  4. Intoxicação em cães e gatos: diagnóstico toxicológico empregando cromatografia em camada delgada e cromatografia líquida de alta pressão com detecção ultravioleta em amostras estomacais Intoxication in dogs and cats: toxicological diagnosis using thin layer chromatography and high pressure liquid chromatography with ultraviolet detection in stomach samples

    Directory of Open Access Journals (Sweden)

    Rachel Picada Bulcão

    2010-05-01

    óticos mais envolvidos nessas intoxicações.The pesticides and rodenticides are responsible for several human and animal intoxications. Preliminary data suggest that the illegal use of these compounds to poison small animals is a common practice in the central region of the Rio Grande do Sul state. The Laboratory of Toxicology received samples, of cases in which the main suspected cause of death is poisoning by pesticides or exogenous rodenticides (licit and illicit. The aim of this study was show the survey of small animals poisoned and analyzed by LATOX during the period of 2004 to 2008 identifying the xenobiotics by optimized analytical methods, including screening by thin-layer chromatography (TLC and a possible confirmation by high performance liquid chromatography - ultraviolet detection (HPLC-UV. In this period 68 samples were analyzed from small poisoned animals. The biological samples analyzed were stomach and stomach content and the TLC permitted carbamates, warfarin and stricnine identification. This proved to be an efficient and adequate technique for this purpose, relatively fast, inexpensive and with low matrix interference. The screening by HPLC for N-methyl carbamates was also realized: aldicarb, carbaryl, carbofuran and propoxur. The analysis showed that the main toxic agent found was aldicarb (chumbinho, responsible for 39.7% of poisoning (27 cases, followed by stricnine (6 cases, warfarin (3 cases and sodium monofluoracetate (1 case. Thus, the 'chumbinho' was the main agent involved in dogs and cats poisoning in the central region of the state, during the analyzed period. The analytical methods TLC and HPLC can be used efficiently in laboratorial routine for identification and confirmation of xenobiotics involved in these poisonings.

  5. Symmetrical periods used as matching layers in multilayer thin film design

    Institute of Scientific and Technical Information of China (English)

    Dan Wang; Zhengxiu Fan; Jianbing Huang; Jun Bi; Yingjian Wang

    2006-01-01

    Properties of symmetrical layers as matching layers in multilayer thin film design were analyzed. Acalculation method was presented to derive parameters of desired equivalent refractive index. A harmonicbeam splitter was designed and fabricated to test this matching method.

  6. Thin hybrid pixel assembly with backside compensation layer on ROIC

    Science.gov (United States)

    Bates, R.; Buttar, C.; McMullen, T.; Cunningham, L.; Ashby, J.; Doherty, F.; Gray, C.; Pares, G.; Vignoud, L.; Kholti, B.; Vahanen, S.

    2017-01-01

    The entire ATLAS inner tracking system will be replaced for operation at the HL-LHC . This will include a significantly larger pixel detector of approximately 15 m2. For this project, it is critical to reduce the mass of the hybrid pixel modules and this requires thinning both the sensor and readout chips to about 150 micrometres each. The thinning of the silicon chips leads to low bump yield for SnAg bumps due to bad co-planarity of the two chips at the solder reflow stage creating dead zones within the pixel array. In the case of the ATLAS FEI4 pixel readout chip thinned to 100 micrometres, the chip is concave, with the front side in compression, with a bow of +100 micrometres at room temperature which varies to a bow of -175 micrometres at the SnAg solder reflow temperature, caused by the CTE mismatch between the materials in the CMOS stack and the silicon substrate. A new wafer level process to address the issue of low bump yield be controlling the chip bow has been developed. A back-side dielectric and metal stack of SiN and Al:Si has been deposited on the readout chip wafer to dynamically compensate the stress of the front side stack. In keeping with a 3D process the materials used are compatible with Through Silicon Via (TSV) technology with a TSV last approach which is under development for this chip. It is demonstrated that the amplitude of the correction can be manipulated by the deposition conditions and thickness of the SiN/Al:Si stack. The bow magnitude over the temperature range for the best sample to date is reduced by almost a factor of 4 and the sign of the bow (shape of the die) remains constant. Further development of the backside deposition conditions is on-going with the target of close to zero bow at the solder reflow temperature and a minimal bow magnitude throughout the temperature range. Assemblies produced from FEI4 readout wafers thinned to 100 micrometres with the backside compensation layer have been made for the first time and

  7. Thin-layer chromatographic specification and separation of Cu(1+), Cu(2+), Ni(2+), and Co(2+) cations.

    Science.gov (United States)

    Savasci, Sahin; Akçay, Mehmet; Ergül, Soner

    2010-07-01

    The M(PyDTC)(2) (M: Cu, Co, or Ni) and CuPyDTC complexes, prepared by reactions of ammonium pyrrolidinedithiocarbamate with metal nitrates, are examined for qualitative analysis, speciation, and mutual separation using thin-layer chromatography systems. These complexes and their mixtures are spotted to the activated and non-activated thin layers of silica gel 60GF(254) (Si-60GF(254)) with a 250-microm thickness. Toluene-dichloromethane mixtures (4:1, 1:1, 1:4 v/v) are used as mobile phases for running of the complexes. All of these chromatographic systems are successfully used for speciation of Cu(2+) and Cu(1+) cations. The best analytical separation for the qualitative analysis of corresponding metal cations and mutual separation of components in M(PyDTC)(2) and CuPyDTC complexes are obtained when using pure toluene-dichloromethane (1:1 v/v) on the activated layer. This study shows that it is possible to qualitatively analyze and satisfactorily separate a mixture of Cu(1+), Cu(2+), Ni(2+), and Co(2+) cations on cited chromatographic systems. These results may be also said for the adaptability or validity on column chromatography.

  8. Modeling the influence of the seeding layer on the transition behavior of a ferroelectric thin film

    Energy Technology Data Exchange (ETDEWEB)

    Oubelkacem, A.; Essaoudi, I. [Laboratoire de Physique des Materiaux et Modelisation des Systemes, Unite Associee au CNRST, URAC: 08, University of Moulay Ismail, Faculty of Sciences, Physics Department, B.P. 11201, Meknes (Morocco); Ainane, A., E-mail: ainane@pks.mpg.de [Laboratoire de Physique des Materiaux et Modelisation des Systemes, Unite Associee au CNRST, URAC: 08, University of Moulay Ismail, Faculty of Sciences, Physics Department, B.P. 11201, Meknes (Morocco); Max-Planck-Institut fuer Physik Complexer Systeme, Noethnitzer Str. 38 D-01187 Dresden (Germany); Laboratoire de Physique des Milieux Denses (LPMD) Institut de Chimie, Physique et Materiaux (ICPM), 1 Bd. Arago, 57070, Metz (France); INFM-Dip. Fisica. Univ. Padova, via Marzolo 8, 54124 Padova (Italy); Saber, M. [Laboratoire de Physique des Materiaux et Modelisation des Systemes, Unite Associee au CNRST, URAC: 08, University of Moulay Ismail, Faculty of Sciences, Physics Department, B.P. 11201, Meknes (Morocco); Max-Planck-Institut fuer Physik Complexer Systeme, Noethnitzer Str. 38 D-01187 Dresden (Germany); Dujardin, F. [Laboratoire de Physique des Milieux Denses (LPMD) Institut de Chimie, Physique et Materiaux (ICPM), 1 Bd. Arago, 57070, Metz (France)

    2011-10-31

    The transition properties of a ferroelectric thin film with seeding layers were studied using the effective field theory with a probability distribution technique that accounts for the self-spin correlation functions. The effect of interaction parameters for the seeding layer on the phase diagram was also examined. We calculated the critical temperature and the polarization of the ferroelectric thin film for different seeding layer structures. We found that the seeding layer can greatly increase the Curie temperature and the polarization.

  9. Graphene oxide monolayers as atomically thin seeding layers for atomic layer deposition of metal oxides

    Science.gov (United States)

    Nourbakhsh, Amirhasan; Adelmann, Christoph; Song, Yi; Lee, Chang Seung; Asselberghs, Inge; Huyghebaert, Cedric; Brizzi, Simone; Tallarida, Massimo; Schmeißer, Dieter; van Elshocht, Sven; Heyns, Marc; Kong, Jing; Palacios, Tomás; de Gendt, Stefan

    2015-06-01

    Graphene oxide (GO) was explored as an atomically-thin transferable seed layer for the atomic layer deposition (ALD) of dielectric materials on any substrate of choice. This approach does not require specific chemical groups on the target surface to initiate ALD. This establishes GO as a unique interface which enables the growth of dielectric materials on a wide range of substrate materials and opens up numerous prospects for applications. In this work, a mild oxygen plasma treatment was used to oxidize graphene monolayers with well-controlled and tunable density of epoxide functional groups. This was confirmed by synchrotron-radiation photoelectron spectroscopy. In addition, density functional theory calculations were carried out on representative epoxidized graphene monolayer models to correlate the capacitive properties of GO with its electronic structure. Capacitance-voltage measurements showed that the capacitive behavior of Al2O3/GO depends on the oxidation level of GO. Finally, GO was successfully used as an ALD seed layer for the deposition of Al2O3 on chemically inert single layer graphene, resulting in high performance top-gated field-effect transistors.Graphene oxide (GO) was explored as an atomically-thin transferable seed layer for the atomic layer deposition (ALD) of dielectric materials on any substrate of choice. This approach does not require specific chemical groups on the target surface to initiate ALD. This establishes GO as a unique interface which enables the growth of dielectric materials on a wide range of substrate materials and opens up numerous prospects for applications. In this work, a mild oxygen plasma treatment was used to oxidize graphene monolayers with well-controlled and tunable density of epoxide functional groups. This was confirmed by synchrotron-radiation photoelectron spectroscopy. In addition, density functional theory calculations were carried out on representative epoxidized graphene monolayer models to correlate the

  10. Determinação de daidzeína, genisteína e gliciteína em cápsulas de isoflavonas por cromatografia em camada delgada (CCD e cromatografia líquida de alta eficiência (CLAE Determination of daidzein, genistein and glycitein in isoflavone capsules by thin layer chromatography (TLC and high performance liquid chromatography (HPLC

    Directory of Open Access Journals (Sweden)

    Isabela da Costa César

    2007-12-01

    isoflavone capsules, carried out by high performance liquid chromatography (HPLC, showed high variation in the content of the three aglycones, after acid hydrolysis. The contents varied in the following way, in the 18 batches of evaluated capsules: daidzein (13.34 to 76.20 mg/capsule, genistein (0.61 to 27.18 mg/capsule and glycitein (0.49 to 8.80 mg/capsule.

  11. Using thin metal layers on composite structures for shielding the electromagnetic pulse caused by nearby lightning

    NARCIS (Netherlands)

    Blaj, M.A.; Buesink, F.J.K.; Damstra, G.C.; Leferink, F.B.J.

    2011-01-01

    Electronic systems in composite structures could be vulnerable to the (dominant magnetic) field caused by a lightning strike, because only thin layers of metal can be used on composite structures. Thin layers result in a very low shielding effectiveness against magnetic fields. Many experiments usin

  12. Proteins at fluid interfaces: adsorption layers and thin liquid films.

    Science.gov (United States)

    Yampolskaya, Galina; Platikanov, Dimo

    2006-12-21

    A review in which many original published results of the authors as well as many other papers are discussed. The structure and some properties of the globular proteins are shortly presented, special accent being put on the alpha-chymotrypsin (alpha-ChT), lysozyme (LZ), human serum albumin (HSA), and bovine serum albumin (BSA) which have been used in the experiments with thin liquid films. The behaviour of protein adsorption layers (PAL) is extensively discussed. The dynamics of PAL formation, including the kinetics of adsorption as well as the time evolution of the surface tension of protein aqueous solutions, are considered. A considerable place is devoted to the surface tension and adsorption isotherms of the globular protein solutions, the simulation of PAL by interacting hard spheres, the experimental surface tension isotherms of the above mentioned proteins, and the interfacial tension isotherms for the protein aqueous solution/oil interface. The rheological properties of PAL at fluid interfaces are shortly reviewed. After a brief information about the experimental methods for investigation of protein thin liquid (foam or emulsion) films, the properties of the protein black foam films are extensively discussed: the conditions for their formation, the influence of the electrolytes and pH on the film type and stability, the thermodynamic properties of the black foam films, the contact angles film/bulk and their dynamic hysteresis. The next center of attention concerns some properties of the protein emulsion films: the conditions for formation of emulsion black films, the formation and development of a dimpling in microscopic, circular films. The protein-phospholipid mixed foam films are also briefly considered.

  13. Design of step composition gradient thin film transistor channel layers grown by atomic layer deposition

    Science.gov (United States)

    Ahn, Cheol Hyoun; Hee Kim, So; Gu Yun, Myeong; Koun Cho, Hyung

    2014-12-01

    In this study, we proposed the artificially designed channel structure in oxide thin-film transistors (TFTs) called a "step-composition gradient channel." We demonstrated Al step-composition gradient Al-Zn-O (AZO) channel structures consisting of three AZO layers with different Al contents. The effects of stacking sequence in the step-composition gradient channel on performance and electrical stability of bottom-gate TFT devices were investigated with two channels of inverse stacking order (ascending/descending step-composition). The TFT with ascending step-composition channel structure (5 → 10 → 14 at. % Al composition) showed relatively negative threshold voltage (-3.7 V) and good instability characteristics with a reduced threshold voltage shift ( Δ 1.4 V), which was related to the alignment of the conduction band off-set within the channel layer depending on the Al contents. Finally, the reduced Al composition in the initial layer of ascending step-composition channel resulted in the best field effect mobility of 4.5 cm2/V s. We presented a unique active layer of the "step-composition gradient channel" in the oxide TFTs and explained the mechanism of adequate channel design.

  14. Graphene oxide monolayers as atomically thin seeding layers for atomic layer deposition of metal oxides.

    Science.gov (United States)

    Nourbakhsh, Amirhasan; Adelmann, Christoph; Song, Yi; Lee, Chang Seung; Asselberghs, Inge; Huyghebaert, Cedric; Brizzi, Simone; Tallarida, Massimo; Schmeisser, Dieter; Van Elshocht, Sven; Heyns, Marc; Kong, Jing; Palacios, Tomás; De Gendt, Stefan

    2015-06-28

    Graphene oxide (GO) was explored as an atomically-thin transferable seed layer for the atomic layer deposition (ALD) of dielectric materials on any substrate of choice. This approach does not require specific chemical groups on the target surface to initiate ALD. This establishes GO as a unique interface which enables the growth of dielectric materials on a wide range of substrate materials and opens up numerous prospects for applications. In this work, a mild oxygen plasma treatment was used to oxidize graphene monolayers with well-controlled and tunable density of epoxide functional groups. This was confirmed by synchrotron-radiation photoelectron spectroscopy. In addition, density functional theory calculations were carried out on representative epoxidized graphene monolayer models to correlate the capacitive properties of GO with its electronic structure. Capacitance-voltage measurements showed that the capacitive behavior of Al2O3/GO depends on the oxidation level of GO. Finally, GO was successfully used as an ALD seed layer for the deposition of Al2O3 on chemically inert single layer graphene, resulting in high performance top-gated field-effect transistors.

  15. Note: Automatic layer-by-layer spraying system for functional thin film coatings

    Science.gov (United States)

    Seo, Seongmin; Lee, Sangmin; Park, Yong Tae

    2016-03-01

    In this study, we have constructed an automatic spray machine for producing polyelectrolyte multilayer films containing various functional materials on wide substrates via the layer-by-layer (LbL) assembly technique. The proposed machine exhibits advantages in terms of automation, process speed, and versatility. Furthermore, it has several features that allow a fully automated spraying operation, such as various two-dimensional spraying paths, control of the flow rate and operating speed, air-assist fan-shaped twin-fluid nozzles, and an optical display. The robot uniformly sprays aqueous mixtures containing complementary (e.g., oppositely charged, capable of hydrogen bonding, or capable of covalent bonding) species onto a large-area substrate. Between each deposition of opposite species, samples are spray-rinsed with deionized water and blow-dried with air. The spraying, rinsing, and drying areas and times are adjustable by a computer program. Twenty-bilayer flame-retardant thin films were prepared in order to compare the performance of the spray-assisted LbL assembly with a sample produced by conventional dipping. The spray-coated film exhibited a reduction of afterglow time in vertical flame tests, indicating that the spray-LbL technique is a simple method to produce functional thin film coatings.

  16. The effect of solvent grade on thin layer chromatographic analysis of writing inks.

    Science.gov (United States)

    Barker, Julia; Ramotowski, Robert; Nwokoye, Jennie

    2016-09-01

    The effects on the separation of writing ink dyes and the repeatability of the Rf values from using different grades of chemicals used in solvent system I (SSI) and solvent system II (SSII) for thin-layer chromatographic (TLC) ink analysis were studied. Solvent system I consists of a 70:35:30 mixture of ethyl acetate, ethanol, and water. Solvent system II consists of a 50:10:15 mixture of ethanol, water, and n-butanol. Since 1991, the ASTM International Guideline E 1422 has recommended that the purity of solvents should be "reagent grade" and that water quality should be "distilled or equivalent." A total of 25 blue and 25 black inks were selected for analysis. Thirteen of each color ink were ballpoint and the remainder were non-ballpoint. The observations show that there is a solvent grade effect on both the separation and clarity of the ink dyes and the repeatability of their Rf values. These results indicate that the grades and manufacturers of solvents used in solvent systems for thin-layer chromatography must be consistent. This is especially critical for searching TLC plates against those from a large ink library in casework. Overall, the combination of solvents that produced the best results for solvent system I consisted of denatured ethanol, HPLC grade water, and ACS grade ethyl acetate. There was no consensus for the best combination of solvent grades for solvent system II; however, it was shown that different grades did have an effect on the separation of ink components.

  17. Amplitude various angles (AVA) phenomena in thin layer reservoir: Case study of various reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Nurhandoko, Bagus Endar B., E-mail: bagusnur@bdg.centrin.net.id, E-mail: bagusnur@rock-fluid.com [Wave Inversion and Subsurface Fluid Imaging Research Laboratory (WISFIR), Basic Science Center A 4" t" hfloor, Physics Dept., FMIPA, Institut Teknologi Bandung (Indonesia); Rock Fluid Imaging Lab., Bandung (Indonesia); Susilowati, E-mail: bagusnur@bdg.centrin.net.id, E-mail: bagusnur@rock-fluid.com [Rock Fluid Imaging Lab., Bandung (Indonesia)

    2015-04-16

    Amplitude various offset is widely used in petroleum exploration as well as in petroleum development field. Generally, phenomenon of amplitude in various angles assumes reservoir’s layer is quite thick. It also means that the wave is assumed as a very high frequency. But, in natural condition, the seismic wave is band limited and has quite low frequency. Therefore, topic about amplitude various angles in thin layer reservoir as well as low frequency assumption is important to be considered. Thin layer reservoir means the thickness of reservoir is about or less than quarter of wavelength. In this paper, I studied about the reflection phenomena in elastic wave which considering interference from thin layer reservoir and transmission wave. I applied Zoeppritz equation for modeling reflected wave of top reservoir, reflected wave of bottom reservoir, and also transmission elastic wave of reservoir. Results show that the phenomena of AVA in thin layer reservoir are frequency dependent. Thin layer reservoir causes interference between reflected wave of top reservoir and reflected wave of bottom reservoir. These phenomena are frequently neglected, however, in real practices. Even though, the impact of inattention in interference phenomena caused by thin layer in AVA may cause inaccurate reservoir characterization. The relation between classes of AVA reservoir and reservoir’s character are different when effect of ones in thin reservoir and ones in thick reservoir are compared. In this paper, I present some AVA phenomena including its cross plot in various thin reservoir types based on some rock physics data of Indonesia.

  18. Mathematical analogies in physics. Thin-layer wave theory

    Directory of Open Access Journals (Sweden)

    José M. Carcione

    2014-03-01

    Full Text Available Field theory applies to elastodynamics, electromagnetism, quantum mechanics, gravitation and other similar fields of physics, where the basic equations describing the phenomenon are based on constitutive relations and balance equations. For instance, in elastodynamics, these are the stress-strain relations and the equations of momentum conservation (Euler-Newton law. In these cases, the same mathematical theory can be used, by establishing appropriate mathematical equivalences (or analogies between material properties and field variables. For instance, the wave equation and the related mathematical developments can be used to describe anelastic and electromagnetic wave propagation, and are extensively used in quantum mechanics. In this work, we obtain the mathematical analogy for the reflection/refraction (transmission problem of a thin layer embedded between dissimilar media, considering the presence of anisotropy and attenuation/viscosity in the viscoelastic case, conductivity in the electromagnetic case and a potential barrier in quantum physics (the tunnel effect. The analogy is mainly illustrated with geophysical examples of propagation of S (shear, P (compressional, TM (transverse-magnetic and TE (transverse-electric waves. The tunnel effect is obtained as a special case of viscoelastic waves at normal incidence.

  19. Junction conditions in quadratic gravity: thin shells and double layers

    CERN Document Server

    Reina, Borja; Vera, Raül

    2015-01-01

    The junction conditions for the most general gravitational theory with a Lagrangian containing terms quadratic in the curvature are derived. We include the cases with a possible concentration of matter on the joining hypersurface -termed as thin shells, domain walls or braneworlds in the literature- as well as the proper matching conditions where only finite jumps of the energy-momentum tensor are allowed. In the latter case we prove that the matching conditions are more demanding than in General Relativity. In the former case, we show that generically the shells/domain walls are of a new kind because they possess, in addition to the standard energy-momentum tensor, a double layer energy-momentum contribution which actually induces an external energy flux vector and an external scalar pressure/tension on the shell. We prove that all these contributions are necessary to make the entire energy-momentum tensor divergence-free, and we present the field equations satisfied by these energy-momentum quantities. The ...

  20. Somatic Embryogenesis of Lilium from Microbulb Transverse Thin Cell Layers.

    Science.gov (United States)

    Marinangeli, Pablo

    2016-01-01

    A reliable somatic embryogenesis protocol is a prerequisite for application of other plant biotechniques. Several protocols were reported for genus Lilium, with variable success. Between them, transverse Thin Cell Layers (tTCL) were used efficiently to induce indirect somatic embryogenesis of Lilium. Somatic embryogenesis potential is dependent on the genotype, explant, and culture medium composition, especially as for plant growth regulators and environmental conditions. Usually, the process comprises three phases: embryogenic callus induction, embryogenic callus proliferation and somatic embryo germination. Somatic embryo germination can be achieved in light or dark. In the first case, complete plantlets are formed, with green leaves and pseudobulb in the base. In darkness, microbulbs are formed from single somatic embryos or clusters. A last phase of microbulb enlargement allows plantlets or microbulbs to increase their biomass. These enlarged microbulbs do not need special acclimatization conditions when transferred to soil and quickly produce sturdy plants. This chapter describes a protocol for somatic embryogenesis of Lilium using tTCL from microbulbs.

  1. Characterization of Thin Layer Hot Air Drying of Celery Root

    Directory of Open Access Journals (Sweden)

    Xiaohong Wei

    2015-08-01

    Full Text Available The hot air drying characteristics of celery root were evaluated in a laboratory scale dryer at the drying temperatures of 50, 60, 70 and 80°C. The effect of hot air drying on drying time, drying rate, moisture content, moisture ratio and effective moisture diffusivity of celery root was investigated. Fifteen thin layer drying models were fitted by using experimental drying data. The fitting effect of model predictions was evaluated by using the values of coefficient of determination, sum squared error, root mean square error and chi-square. The results showed fitting accuracy of model 15 (Hii et al.,2009 gave a better fit for all drying conditions applied. The average values of effective moisture diffusivities of celery root ranged from 1.957×10-9 to 9.016×10-9 within the given drying temperature range. With in a certain temperature range (50-70°C, the average effective moisture diffusivities of celery root increased with increased temperature. The activation energy was estimated as 21.817 KJ/mol using an exponential expression based on the Arrhenius equation.

  2. Junction conditions in quadratic gravity: thin shells and double layers

    Science.gov (United States)

    Reina, Borja; Senovilla, José M. M.; Vera, Raül

    2016-05-01

    The junction conditions for the most general gravitational theory with a Lagrangian containing terms quadratic in the curvature are derived. We include the cases with a possible concentration of matter on the joining hypersurface—termed as thin shells, domain walls or braneworlds in the literature—as well as the proper matching conditions where only finite jumps of the energy-momentum tensor are allowed. In the latter case we prove that the matching conditions are more demanding than in general relativity. In the former case, we show that generically the shells/domain walls are of a new kind because they possess, in addition to the standard energy-momentum tensor, a double layer energy-momentum contribution which actually induces an external energy flux vector and an external scalar pressure/tension on the shell. We prove that all these contributions are necessary to make the entire energy-momentum tensor divergence-free, and we present the field equations satisfied by these energy-momentum quantities. The consequences of all these results are briefly analyzed.

  3. Fibromyalgia Is Correlated with Retinal Nerve Fiber Layer Thinning

    Science.gov (United States)

    Garcia-Martin, Elena; Garcia-Campayo, Javier; Puebla-Guedea, Marta; Ascaso, Francisco J.; Roca, Miguel; Gutierrez-Ruiz, Fernando; Vilades, Elisa; Polo, Vicente; Larrosa, Jose M.; Pablo, Luis E.; Satue, Maria

    2016-01-01

    Objective To investigate whether fibromyalgia induces axonal damage in the optic nerve that can be detected using optical coherence tomography (OCT), as the retinal nerve fiber layer (RNFL) is atrophied in patients with fibromyalgia compared with controls. Methods Fibromyalgia patients (n = 116) and age-matched healthy controls (n = 144) were included in this observational and prospective cohort study. All subjects underwent visual acuity measurement and structural analysis of the RNFL using two OCT devices (Cirrus and Spectralis). Fibromyalgia patients were evaluated according to Giesecke’s fibromyalgia subgroups, the Fibromyalgia Impact Questionnaire (FIQ), and the European Quality of Life-5 Dimensions (EQ5D) scale. We compared the differences between fibromyalgia patients and controls, and analyzed the correlations between OCT measurements, disease duration, fibromyalgia subgroups, severity, and quality of life. The impact on quality of life in fibromyalgia subgroups and in patients with different disease severity was also analyzed. Results A significant decrease in the RNFL was detected in fibromyalgia patients compared with controls using the two OCT devices: Cirrus OCT ganglion cell layer analysis registered a significant decrease in the minimum thickness of the inner plexiform layer (74.99±16.63 vs 79.36±3.38 μm, respectively; p = 0.023), nasal inferior, temporal inferior and temporal superior sectors (p = 0.040; 0.011 and 0.046 respectively). The Glaucoma application of the Spectralis OCT revealed thinning in the nasal, temporal inferior and temporal superior sectors (p = 0.009, 0.006, and 0.002 respectively) of fibromyalgia patients and the Axonal application in all sectors, except the nasal superior and temporal sectors. The odds ratio (OR) to estimate the size effect of FM in RNFL thickness was 1.39. RNFL atrophy was detected in patients with FIQ scores fibromyalgia (FIQ≥60) compared with patients with mild fibromyalgia (FIQfibromyalgia exhibited

  4. Fermi level de-pinning of aluminium contacts to n-type germanium using thin atomic layer deposited layers

    Energy Technology Data Exchange (ETDEWEB)

    Gajula, D. R., E-mail: dgajula01@qub.ac.uk; Baine, P.; Armstrong, B. M.; McNeill, D. W. [School of Electronics, Electrical Engineering and Computer Science, Queen' s University Belfast, Ashby Building, Stranmillis Road, Belfast BT9 5AH (United Kingdom); Modreanu, M.; Hurley, P. K. [Tyndall National Institute, University College Cork, Lee Maltings, Cork (Ireland)

    2014-01-06

    Fermi-level pinning of aluminium on n-type germanium (n-Ge) was reduced by insertion of a thin interfacial dielectric by atomic layer deposition. The barrier height for aluminium contacts on n-Ge was reduced from 0.7 eV to a value of 0.28 eV for a thin Al{sub 2}O{sub 3} interfacial layer (∼2.8 nm). For diodes with an Al{sub 2}O{sub 3} interfacial layer, the contact resistance started to increase for layer thicknesses above 2.8 nm. For diodes with a HfO{sub 2} interfacial layer, the barrier height was also reduced but the contact resistance increased dramatically for layer thicknesses above 1.5 nm.

  5. Investigation of crystallization behavior of CIG-Se bi-layer thin films.

    Science.gov (United States)

    Park, Mi Sun; Sung, Shi-Joon; Kim, Dae-Hwan; Kang, Jin-Kyu

    2012-04-01

    Copper indium gallium diselenide (CIGSe) thin film was fabricated via a thermal treatment of GIG-Se bi-layer thin films. A CIG layer was prepared first, by a chemical solution deposition (CSD) process. The Se layer was deposited separately on the CIG layer by evaporation. The GIG-Se bi-layer then underwent a thermal treatment to cause a reaction between the two layers. In order to investigate the mechanism of CIG-Se bi-layer crystallization, the thermal treatment temperature was varied. The properties of the prepared CIGSe2 thin films were analyzed using X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive spectrometry (EDS), and UV-visible spectrophotometry.

  6. Photoluminescence-based quality control for thin film absorber layers of photovoltaic devices

    Energy Technology Data Exchange (ETDEWEB)

    Repins, Ingrid L.; Kuciauskas, Darius

    2015-07-07

    A time-resolved photoluminescence-based system providing quality control during manufacture of thin film absorber layers for photovoltaic devices. The system includes a laser generating excitation beams and an optical fiber with an end used both for directing each excitation beam onto a thin film absorber layer and for collecting photoluminescence from the absorber layer. The system includes a processor determining a quality control parameter such as minority carrier lifetime of the thin film absorber layer based on the collected photoluminescence. In some implementations, the laser is a low power, pulsed diode laser having photon energy at least great enough to excite electron hole pairs in the thin film absorber layer. The scattered light may be filterable from the collected photoluminescence, and the system may include a dichroic beam splitter and a filter that transmit the photoluminescence and remove scattered laser light prior to delivery to a photodetector and a digital oscilloscope.

  7. Identificação de alcalóides xantínicos do guaraná (Paullinia cupana KBK por cromatografia em camada delgada em amostras de urina Identification of xanthine alkaloids of guaraná in urine samples using thin-layer chromatography

    Directory of Open Access Journals (Sweden)

    Maurílio de Carvalho Mousinho

    1986-01-01

    Full Text Available É proposto um esquema analítico, simples e sensível, para identificação de bases xânticas do guaraná em material biológico. Amostras de urina de consumidores de guaraná são submetidos à extração com clorofórmio em meio alcalino. Após evaporação dos extratos, os resíduos são transferidos para uma cromatoplaca de silicagel G (0,25 mm e desenvolvidos em acetato de etilaciclohexano-metanol-hidróxido de amônio, 70:15:10:5 (11,5 cm e, a seguir, acetato de etilaciclohexano-hidróxido de amônio, 50:40:0,1 (15,5 cm na mesma direção. A revelação é feita com o reativo de DRAGENDORFF iodado.A simple and sensitive thin layer chromatographic analytical method is proposed for the identification of xanthic bases of guarana Paullinia cupana HBK in urine samples. The samples were obtained from the consumers of the stimulant drink and submitted to extraction with chloroform in alkaline medium. After evaporation of the extracts residues were transferred to silicagel G (0,25 mm thin-layer plates and developed with ethylacetatecyclohexane-methanol, ammonium hydroxide 50:40:0,1 for 14,5 cm in the same dimension. The spots were revealed with Dragendorff-iodate chromogen agent.

  8. Back contact buffer layer for thin-film solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Compaan, Alvin D.; Plotnikov, Victor V.

    2014-09-09

    A photovoltaic cell structure is disclosed that includes a buffer/passivation layer at a CdTe/Back contact interface. The buffer/passivation layer is formed from the same material that forms the n-type semiconductor active layer. In one embodiment, the buffer layer and the n-type semiconductor active layer are formed from cadmium sulfide (CdS). A method of forming a photovoltaic cell includes the step of forming the semiconductor active layers and the buffer/passivation layer within the same deposition chamber and using the same material source.

  9. The photoluminescent lifetime of polyelectrolytes in thin films formed via layer by layer self-assembly.

    Science.gov (United States)

    Reilly, Roseanne S; Smyth, Ciarán A; Rakovich, Yury P; McCabe, Eithne M

    2009-03-04

    We present results on luminescence lifetime studies of thin multilayer films of polyelectrolyte molecules produced via layer by layer (LbL) electrostatic assembly. We found that, in contrast to common assumptions, LbL films show measurable photoluminescent lifetimes with an average value of 6 ns. Scanning fluorescence lifetime imaging microscopy studies combined with steady-state photoluminescence measurements imply that this lifetime may be due to aggregation of polyelectrolyte molecules during preparation of LbL films. This conclusion has been further confirmed by atomic force microscopy (AFM). AFM images clearly show the presence of 100-200 nm high aggregates on the surface of these films. This aggregation of polyelectrolyte molecules contributes significantly to the experimentally detected luminescence decays of any light-emitting samples attached to LbL film, especially in a single molecule detection regime. To demonstrate this effect we compare photoluminescence lifetime results for CdTe quantum dots deposited on the surface of LbL polyelectrolyte films.

  10. A model for thin layer formation by delayed particle settling at sharp density gradients

    Science.gov (United States)

    Prairie, Jennifer C.; White, Brian L.

    2017-02-01

    Thin layers - regions where plankton or particles accumulate vertically on scales of a few meters or less - are common in coastal waters, and have important implications for both trophic dynamics and carbon cycling. These features can form by a variety of biological and physical mechanisms, including localized growth, shear-thinning, and directed swimming. An additional mechanism may result in the formation of thin layers of marine aggregates, which have been shown to decrease their settling velocity when passing through sharp density gradients, a behavior termed delayed settling. Here, we apply a simple vertical advection-diffusion model to predict the properties of aggregate thin layers formed by this process. We assume a constant vertical flux of particles from the surface, which is parameterized by observations from laboratory experiments with marine aggregates. The formation, maintenance, and shape of the layers are described in relation to non-dimensional numbers that depend on environmental conditions and particle settling properties. In particular, model results demonstrate layer intensity and sharpness both increase with higher Péclet number (Pe), that is, under conditions with weaker mixing relative to layer formation. Similarly, more intense and sharper layers are found when the delayed settling behavior of aggregates is characterized by a lower velocity minimum. The model also predicts layers that are vertically asymmetric and highly "peaky" when compared with a Gaussian distribution, features often seen in thin layers in natural environments. Lastly, by comparing model predictions with observations of thin layers in the field, we are able to gain some insight into the applicability of delayed settling as a thin layer formation mechanism in different environmental conditions.

  11. Thin-layer chromatographic (TLC) separations and bioassays of plant extracts to identify antimicrobial compounds.

    Science.gov (United States)

    Kagan, Isabelle A; Flythe, Michael D

    2014-03-27

    A common screen for plant antimicrobial compounds consists of separating plant extracts by paper or thin-layer chromatography (PC or TLC), exposing the chromatograms to microbial suspensions (e.g. fungi or bacteria in broth or agar), allowing time for the microbes to grow in a humid environment, and visualizing zones with no microbial growth. The effectiveness of this screening method, known as bioautography, depends on both the quality of the chromatographic separation and the care taken with microbial culture conditions. This paper describes standard protocols for TLC and contact bioautography with a novel application to amino acid-fermenting bacteria. The extract is separated on flexible (aluminum-backed) silica TLC plates, and bands are visualized under ultraviolet (UV) light. Zones are cut out and incubated face down onto agar inoculated with the test microorganism. Inhibitory bands are visualized by staining the agar plates with tetrazolium red. The method is applied to the separation of red clover (Trifolium pratense cv. Kenland) phenolic compounds and their screening for activity against Clostridium sticklandii, a hyper ammonia-producing bacterium (HAB) that is native to the bovine rumen. The TLC methods apply to many types of plant extracts and other bacterial species (aerobic or anaerobic), as well as fungi, can be used as test organisms if culture conditions are modified to fit the growth requirements of the species.

  12. Growth of α-sexithiophene nanostructures on C60 thin film layers

    DEFF Research Database (Denmark)

    Radziwon, Michal Jędrzej; Madsen, Morten; Balzer, Frank

    2014-01-01

    Organic molecular beam grown -sexithiophene (-6T) forms nanostructured thin films on buckminsterfullerene (C60) thin film layers. At substrate temperatures of 300K during growth a rough continuous film is observed, which develop to larger elongated islands and dendritic- as well as needle like...

  13. Optimization of optical absorption in thin layers of amorphous silicon enhanced by silver nanospheres

    CERN Document Server

    Omelyanovich, Mikhail; Simovski, Constantin

    2015-01-01

    We study a highly controllable perfect plasmonic absorber -- a thin metamaterial layer which possess balanced electric and magnetic responses in some frequency range. We show that this regime is compatible with both metal-backed variant of the structure or its semitransparent variant. This regime can be implemented in a prospective thin-film photovoltaic cell with negligible parasitic losses.

  14. nvestigation on influencing factors in determination of hydrocarbons in heavy oils by thin-layer chromatography flame/ionization detector.%棒状薄层色谱/氢火焰离子化检测器法测定重油烃族组成影响因素的探讨

    Institute of Scientific and Technical Information of China (English)

    杨海鹰; 顾洁; 蔺玉贵

    2001-01-01

    The influencing factors in the determination of hydrocarbons (saturates, aromatics, resins) in heavy oils by thin layer chromatography/flame ionization detection (TLC/FID) were investigated. It has been found that the solvent co -volatization may cause sample loss during the spotting and developing process, and that the quantitative calibration factors can not be used universally. Because the flame temperature of TLC/FLD is much lower than that of GC/FID, the transformation of different compounds in the flame of FID is varied.%对应用棒状薄层色谱/氢火焰离子化检测器(TLC/FID)测定重油烃族组成(饱和烃、芳烃、胶质)时的影响因素作了探讨。研究发现,在点样及展开过程中,溶剂共挥发可引起样品损失;而且,由于TLC/FID的火焰温度远低于一般GC条件下FID的火焰温度,使不同化合物在FID上的燃烧转化情况有差异,因而其定量校正因子不具有通用性。

  15. In situ Validation of the Source of Thin Layers Detected by NOAA Airborne Fish Lidar

    Science.gov (United States)

    2010-09-30

    2009, doi:10.1093/icesjms/fsp029. Donaghay, P.L., Osborn, T.R., 1997. Toward a theory of biological-physical control of harmful algal bloom ...DISTRIBUTION STATEMENT A: Approved for public release; distribution is unlimited. In situ Validation of the Source of Thin Layers Detected by...resulting thin layers impact in situ and remote sensing technologies of critical interest to the Navy. We are also interested in improving our ability

  16. Crystallinity Improvement of ZnO Thin Film on Different Buffer Layers Grown by MBE

    Directory of Open Access Journals (Sweden)

    Shao-Ying Ting

    2012-01-01

    Full Text Available The material and optical properties of ZnO thin film samples grown on different buffer layers on sapphire substrates through a two-step temperature variation growth by molecular beam epitaxy were investigated. The thin buffer layer between the ZnO layer and the sapphire substrate decreased the lattice mismatch to achieve higher quality ZnO thin film growth. A GaN buffer layer slightly increased the quality of the ZnO thin film, but the threading dislocations still stretched along the c-axis of the GaN layer. The use of MgO as the buffer layer decreased the surface roughness of the ZnO thin film by 58.8% due to the suppression of surface cracks through strain transfer of the sample. From deep level emission and rocking curve measurements it was found that the threading dislocations play a more important role than oxygen vacancies for high-quality ZnO thin film growth.

  17. Conduction mechanisms in thin atomic layer deposited Al{sub 2}O{sub 3} layers

    Energy Technology Data Exchange (ETDEWEB)

    Spahr, Holger; Montzka, Sebastian; Reinker, Johannes; Hirschberg, Felix; Kowalsky, Wolfgang; Johannes, Hans-Hermann, E-mail: h2.johannes@ihf.tu-bs.de [Institut für Hochfrequenztechnik, Technische Universität Braunschweig, Schleinitzstraße 22, 38106 Braunschweig (Germany)

    2013-11-14

    Thin Al{sub 2}O{sub 3} layers of 2–135 nm thickness deposited by thermal atomic layer deposition at 80 °C were characterized regarding the current limiting mechanisms by increasing voltage ramp stress. By analyzing the j(U)-characteristics regarding ohmic injection, space charge limited current (SCLC), Schottky-emission, Fowler-Nordheim-tunneling, and Poole-Frenkel-emission, the limiting mechanisms were identified. This was performed by rearranging and plotting the data in a linear scale, such as Schottky-plot, Poole-Frenkel-plot, and Fowler-Nordheim-plot. Linear regression then was applied to the data to extract the values of relative permittivity from Schottky-plot slope and Poole-Frenkel-plot slope. From Fowler-Nordheim-plot slope, the Fowler-Nordheim-energy-barrier was extracted. Example measurements in addition to a statistical overview of the results of all investigated samples are provided. Linear regression was applied to the region of the data that matches the realistic values most. It is concluded that ohmic injection and therefore SCLC only occurs at thicknesses below 12 nm and that the Poole-Frenkel-effect is no significant current limiting process. The extracted Fowler-Nordheim-barriers vary in the range of up to approximately 4 eV but do not show a specific trend. It is discussed whether the negative slope in the Fowler-Nordheim-plot could in some cases be a misinterpreted trap filled limit in the case of space charge limited current.

  18. Studies of oxide-based thin-layered heterostructures by X-ray scattering methods

    Energy Technology Data Exchange (ETDEWEB)

    Durand, O. [Thales Research and Technology France, Route Departementale 128, F-91767 Palaiseau Cedex (France)]. E-mail: olivier.durand@thalesgroup.com; Rogers, D. [Nanovation SARL, 103 bis rue de Versailles 91400 Orsay (France); Universite de Technologie de Troyes, 10-12 rue Marie Curie, 10010 (France); Teherani, F. Hosseini [Nanovation SARL, 103 bis rue de Versailles 91400 Orsay (France); Andrieux, M. [LEMHE, ICMMOCNRS-UMR 8182, Universite d' Orsay, Batiment 410, 91410 Orsay (France); Modreanu, M. [Tyndall National Institute, Lee Maltings, Prospect Row, Cork (Ireland)

    2007-06-04

    Some X-ray scattering methods (X-ray reflectometry and Diffractometry) dedicated to the study of thin-layered heterostructures are presented with a particular focus, for practical purposes, on the description of fast, accurate and robust techniques. The use of X-ray scattering metrology as a routinely working non-destructive testing method, particularly by using procedures simplifying the data-evaluation, is emphasized. The model-independent Fourier-inversion method applied to a reflectivity curve allows a fast determination of the individual layer thicknesses. We demonstrate the capability of this method by reporting X-ray reflectometry study on multilayered oxide structures, even when the number of the layers constitutive of the stack is not known a-priori. Fast Fourier transform-based procedure has also been employed successfully on high resolution X-ray diffraction profiles. A study of the reliability of the integral-breadth methods in diffraction line-broadening analysis applied to thin layers, in order to determine coherent domain sizes, is also reported. Examples from studies of oxides-based thin-layers heterostructures will illustrate these methods. In particular, X-ray scattering studies performed on high-k HfO{sub 2} and SrZrO{sub 3} thin-layers, a (GaAs/AlOx) waveguide, and a ZnO thin-layer are reported.

  19. Crystalline-crystalline phase transformation in two-dimensional In2Se3 thin layers.

    Science.gov (United States)

    Tao, Xin; Gu, Yi

    2013-08-14

    We report, for the first time, the fabrication of single-crystal In2Se3 thin layers using mechanical exfoliation and studies of crystalline-crystalline (α → β) phase transformations as well as the corresponding changes of the electrical properties in these thin layers. Particularly, using electron microscopy and correlative in situ micro-Raman and electrical measurements, we show that, in contrast to bulk single crystals, the β phase can persist in single-crystal thin layers at room temperature (RT). The single-crystal nature of the layers before and after the phase transition allows for unambiguous determination of changes in the electrical resistivity. Specifically, the β phase has an electrical resistivity about 1-2 orders of magnitude lower than the α phase. Furthermore, we find that the temperature of the α → β phase transformation increases by as much as 130 K with the layer thickness decreasing from ~87 nm to ~4 nm. These single-crystal thin layers are ideal for studying the scaling behavior of the phase transformations and associated changes of the electrical properties. For these In2Se3 thin layers, the accessibility of the β phase at RT, with distinct electrical properties than the α phase, provides the basis for multilevel phase-change memories in a single material system.

  20. Preparation and characterization of polymeric thin films containing gold nanoshells via electrostatic layer-by-layer self-assembly

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sang Ho; Jamison, Andrew C.; Hoffman, David M., E-mail: hoffman@uh.edu; Jacobson, Allan J., E-mail: ajjacob@uh.edu; Lee, T. Randall, E-mail: trlee@uh.edu

    2014-05-02

    As an initial step in the development of surfaces for collecting thermal energy, gold shell/silica core particles (∼ 200 nm in diameter with shells ∼ 25 nm thick) were synthesized and incorporated into organic polymeric thin films. The morphologies of these nanoshells were characterized with scanning and transmission electron microscopy. Powder X-ray diffraction demonstrated that the gold layers were highly crystalline. Thin films containing the gold nanoshells and polyethyleneimine were generated using dip-coating techniques based on electrostatic layer-by-layer self-assembly methods. Scanning electron microscopy was used to image the resultant composite films, which contained uniformly distributed gold nanoshells with limited aggregation. The optical properties were analyzed by absorption spectroscopy, revealing broad extinctions ranging from the visible to the near-IR spectral regions. X-ray photoelectron spectroscopy spectra were also obtained to determine the elements present and the oxidation states of these elements. - Highlights: • Prepared gold nanoshells with broad light absorption from visible to near IR. • Added the gold nanoshells to polyethyleneimine films via layer-by-layer assembly. • The resulting layered thin films exhibited minimal gold nanoshell aggregation.

  1. Review: Applications of chromatography in forensic sciences

    Directory of Open Access Journals (Sweden)

    Manoj S. Charde

    2014-04-01

    Full Text Available This article reviews the use of different Chromatography techniques in the forensic science, Chromatographic technique is very sensitive and selective. Different types of chromatography techniques used were Liquid chromatography -mass spectrometry, Gas chromatography–mass spectrometry, Thin layer chromatography, HPTLC in investigating criminal cases of which chemical warfare’s, terrorist attacks, smugglers, drug abuse, alcoholics. This techniques are promising to detect even pictogram or very less, with selectivity and sensitivity.

  2. Solution processed metal oxide thin film hole transport layers for high performance organic solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Steirer, K. Xerxes; Berry, Joseph J.; Chesin, Jordan P.; Lloyd, Matthew T.; Widjonarko, Nicodemus Edwin; Miedaner, Alexander; Curtis, Calvin J.; Ginley, David S.; Olson, Dana C.

    2017-01-10

    A method for the application of solution processed metal oxide hole transport layers in organic photovoltaic devices and related organic electronics devices is disclosed. The metal oxide may be derived from a metal-organic precursor enabling solution processing of an amorphous, p-type metal oxide. An organic photovoltaic device having solution processed, metal oxide, thin-film hole transport layer.

  3. Cracks in nano-ceramic thin layers produced by laser treatments

    NARCIS (Netherlands)

    De Hosson, JTM; Teeuw, DHJ; Beltz, GE; Selinger, RLB; Kim, KS; Marder, MP

    1999-01-01

    Sol-gel derived thin nano-ceramic layers of TiO2 and Al2O3 are studied using scanning electron microscopy to reveal the microstructure and morphologies of the layers. The low-voltage scanning electron microscope with a field emission gun is equipped with an especially designed lens, where the specim

  4. Thin TaC layer produced by ion mixing

    DEFF Research Database (Denmark)

    Barna, Árpád; Kotis, László; Pécz, Béla

    2012-01-01

    Ion-beam mixing in C/Ta layered systems was investigated. C 8nm/Ta 12nm and C 20nm/Ta 19nm/C 20nm layer systems were irradiated by Ga+ ions of energy in the range of 2–30keV. In case of the 8nm and 20nm thick C cover layers applying 5–8keV and 20–30keV Ga+ ion energy, respectively resulted...... in strongly asymmetric ion mixing; the carbon was readily transported to the Ta layer, while the reverse process was much weaker. Because of the asymmetrical transport the C/TaC interface remained sharp independently from the applied fluence. The carbon transported to the Ta layer formed Ta......Cx. The stoichiometry of the carbide produced varied along the depth. The TaCx layer contained implanted Ga, the concentration of which decreased with increasing depth. The thickness of the TaCx layer could be tailored by the ion fluence and energy making possible to produce coating layer of desired thickness....

  5. 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.

  6. TWO-LAYER MODEL DESCRIPTION OF POLYMER THIN FILM DYNAMICS

    Institute of Scientific and Technical Information of China (English)

    Dong-dong Peng; Ran-xing Nancy Li; Chi-hang Lam; Ophelia K.C.Tsui

    2013-01-01

    Experiments in the past two decades have shown that the glass transition temperature of polymer films can become noticeably different from that of the bulk when the film thickness is decreased below ca.100 nm.It is broadly believed that these observations are caused by a nanometer interfacial layer with dynamics faster or slower than that of the bulk.In this paper,we examine how this idea may be realized by using a two-layer model assuming a hydrodynamic coupling between the interfacial layer and the remaining,bulk-like layer in the film.Illustrative examples will be given showing how the two-layer model is applied to the viscosity measurements of polystyrene and polymethylmethacrylate films supported by silicon oxide,where divergent thickness dependences are observed.

  7. Thin-layer voltammetry of soluble species on screen-printed electrodes: proof of concept.

    Science.gov (United States)

    Botasini, S; Martí, A C; Méndez, E

    2016-10-17

    Thin-layer diffusion conditions were accomplished on screen-printed electrodes by placing a controlled-weight onto the cast solution and allowing for its natural spreading. The restricted diffusive conditions were assessed by cyclic voltammetry at low voltage scan rates and electrochemical impedance spectroscopy. The relationship between the weight exerted over the drop and the thin-layer thickness achieved was determined, in such a way that the simple experimental set-up designed for this work could be developed into a commercial device with variable control of the thin-layer conditions. The experimental results obtained resemble those reported for the voltammetric features of electroactive soluble species employing electrodes modified with carbon nanotubes or graphene layers, suggesting that the attainment of the benefits reported for these nanomaterials could be done simply by forcing the solution to spread over the screen-printed electrodic system to form a thin layer solution. The advantages of thin-layer voltammetry in the kinetic characterization of quasi-reversible and irreversible processes are highlighted.

  8. Thin tungsten telluride layer preparation by thermal annealing

    Science.gov (United States)

    Lu, Wei; Zhang, Yudao; Zhu, Zusong; Lai, Jiawei; Zhao, Chuan; Liu, Xuefeng; Liu, Jing; Sun, Dong

    2016-10-01

    We report a simple method to prepare a thin Tungsten Telluride (WTe2) flake with accurate thickness control, which allows preparing and studying this two dimensional material conveniently. First, the WTe2 flake, which is relatively thick due to its strong interlayer van der Waals forces, is obtained by a conventional mechanical exfoliation method. Then, the exfoliated flake is annealed at 600 °C under a constant Ar protecting flow. Raman and atomic force spectroscopy characterizations demonstrate that thermal annealing can effectively thin down the WTe2 flake and retain its original lattice structure, though its surface smoothness is slightly deteriorated. Additionally, systematical study indicates that the thinning process strongly depends on the initial thickness of the WTe2 flake before annealing: the thinning rate increases from 0.12 nm min-1 to 0.36 nm min-1 as the initial thickness increases from 10 nm to 45 nm, while the roughness of the final product also increases with the increase of its initial thickness. However, the method fails when it is applied to WTe2 flakes thicker than 100 nm, resulting in uneven or burnt surface, which is possibly caused by big cavities formed by a large amount of defects gathered at the top surface.

  9. Microstructure and mechanical behavior of a shape memory Ni-Ti bi-layer thin film

    Energy Technology Data Exchange (ETDEWEB)

    Mohri, Maryam [School of Metallurgy and Materials Engineering, College of Engineering, University of Tehran, Tehran (Iran, Islamic Republic of); Karlsruhe Institute of Technology, Institute of Nanotechnology, 76021 Karlsruhe (Germany); Nili-Ahmadabadi, Mahmoud, E-mail: nili@ut.ac.ir [School of Metallurgy and Materials Engineering, College of Engineering, University of Tehran, Tehran (Iran, Islamic Republic of); Center of Excellence for High Performance Materials, University of Tehran, Tehran (Iran, Islamic Republic of); Ivanisenko, Julia [Karlsruhe Institute of Technology, Institute of Nanotechnology, 76021 Karlsruhe (Germany); Schwaiger, Ruth [Karlsruhe Institute of Technology, Institute for Applied Materials, 76021 Karlsruhe (Germany); Hahn, Horst; Chakravadhanula, Venkata Sai Kiran [Karlsruhe Institute of Technology, Institute of Nanotechnology, 76021 Karlsruhe (Germany)

    2015-05-29

    Two different single-layers and a bi-layer Ni-Ti thin films with chemical compositions of Ni{sub 45}Ti{sub 50}Cu{sub 5}, Ni{sub 50.8}Ti{sub 49.2} and Ni{sub 50.8}Ti{sub 49.2}/Ni{sub 45}Ti{sub 50}Cu{sub 5} (numbers indicate at.%) determined by energy dispersive X-ray spectroscopy were deposited on Si (111) substrates using DC magnetron sputtering. The structures, surface morphology and transformation temperatures of annealed thin films at 500 °C for 15 min and 1 h were studied using grazing incidence X-ray diffraction, transmission electron microscopy (TEM), atomic force microscopy and differential scanning calorimetry (DSC), respectively. Nanoindentation was used to characterize the mechanical properties. The DSC and X-ray diffraction results indicated the austenitic structure of the Ni{sub 50.8}Ti{sub 49.2} and martensitic structure of the Ni{sub 45}Ti{sub 50}Cu{sub 5} thin films while the bi-layer was composed of austenitic and martensitic thin films. TEM study revealed that copper encourages crystallization in the bi-layer such that crystal structure containing nano-precipitates in the Ni{sub 45}Ti{sub 50}Cu{sub 5} layer was detected after 15 min annealing while the Ni{sub 50.8}Ti{sub 49.2} layer crystallized after 60 min at 500 °C. Furthermore, after annealing at 500 °C for 15 min, a precipitate free zone and thin layer amorphous were observed closely to the interface in the top layer. The bi-layer was completely crystallized at 500 °C for 1 h and the orientation of the Ni-rich precipitates indicated a stress gradient in the bi-layer. The bi-layer thin film showed different transformation temperatures and mechanical behavior from the single-layers. The developed bi-layer has different phase transformation temperatures, the higher temperatures of shape memory effect and lower temperature of pseudo-elastic behavior compared to the single-layers. Also, the bi-layer thin film exhibited a combined pseudo-elastic behavior and shape memory effect with a reduced

  10. Fermentation efficiency of cells immobilized on delignified brewers' spent grains after low- and high-temperature thin layer thermal drying.

    Science.gov (United States)

    Tsaousi, Konstantina; Koutinas, Athanasios A; Bekatorou, Argyro; Loukatos, Paul

    2010-09-01

    Low-cost dried yeasts immobilized on delignified brewers' spent grains for use in wine making and brewing were produced by simple thermal drying techniques. To optimize the thermal drying process, vacuum and air stream conditions were examined. Drying of thin layers of the biocatalysts was performed at low (30-38 degrees C) and high temperatures (40-70 degrees C). The fermentation efficiency of the thermally dried biocatalysts was acceptable, with immobilized cells showing a significantly higher thermotolerance compared with free cells. Immobilized cells dried at high temperatures presented slightly improved glucose fermentation efficiency compared with the low-temperature dried biocatalysts. Gas chromatography-mass spectrometry analysis of aroma volatiles of the fermented products revealed an increase of esters, lower higher alcohol formation, and significantly lower concentration of carbonylic compounds.

  11. Co-precipitation of tobramycin into biomimetically coated orthopedic fixation pins employing submicron-thin seed layers of hydroxyapatite.

    Science.gov (United States)

    Sörensen, Jan H; Lilja, Mirjam; Åstrand, Maria; Sörensen, Torben C; Procter, Philip; Strømme, Maria; Steckel, Hartwig

    2014-01-01

    The migration, loosening and cut-out of implants and nosocomial infections are current problems associated with implant surgery. New innovative strategies to overcome these issues are emphasized in today's research. The current work presents a novel strategy involving co-precipitation of tobramycin with biomimetic hydroxyapatite (HA) formation to produce implant coatings that control local drug delivery to prevent early bacterial colonization of the implant. A submicron- thin HA layer served as seed layer for the co-precipitation process and allowed for incorporation of tobramycin in the coating from a stock solution of antibiotic concentrations as high as 20 mg/ml. Concentrations from 0.5 to 20 mg/ml tobramycin and process temperatures of 37 °C and 60 °C were tested to assess the optimal parameters for a thin tobramycin- delivering HA coating on discs and orthopedic fixation pins. The morphology and thickness of the coating and the drug-release profile were evaluated via scanning electron microscopy and high performance liquid chromatography. The coatings delivered pharmaceutically relevant amounts of tobramycin over a period of 12 days. To the best of our knowledge, this is the longest release period ever observed for a fast-loaded biomimetic implant coating. The presented approach could form the foundation for development of combination device/antibiotic delivery vehicles tailored to meet well-defined clinical needs while combating infections and ensuring fast implant in-growth.

  12. Single-borehole measuring method for broken rock zone in gently inclined thin layer weakness structure

    Institute of Scientific and Technical Information of China (English)

    CHEN Qing-fa; ZHOU Ke-ping; LONG Teng-teng; GAO Feng

    2008-01-01

    According to the structural characteristics of gently inclined thin layer rock mass in which lots of weak interlayer existed, the concept of gently inclined thin layer weakness structure was proposed. If single-borehole measuring method of the acoustic along the conventional arrangement mode was used in measuring the broken rock zone in this structure, the change of the relationship curves (Vp-L) between acoustic p-wave velocity (Vp) and borehole depth (L) would present the irregular feature due to the mechanical characteristics of layered rock mass and harmful effects of weak interlayers, and the scope of broken rock zone couldn't be defined quickly. Based on the analysis of the mechanical characteristics of layered rock mass, the propagation rule of acoustic and distributions characteristics of plastic zone and slip zone in layered rock mass, new arrangement mode of acoustic measuring boreholes for broken rock zone in gently inclined thin layer weakness structure was proposed. Namely, the measuring boreholes in two sides were parallel to the strata, the measuring boreholes in the roof and floor perpendicular to the strata. Besides the controlling depth of the measuring boreholes in the scope of the large plastic zones or the large slip zones should be increased. Engineering exampleshowed that new acoustic measuring boreholes arrangement mode had the better applicability and could determine the scope of the broken rock zone in the gently inclined thin layer weakness structure quickly.

  13. X-Ray Diffractometry of Thin Layers - Possibilities and Problems

    Directory of Open Access Journals (Sweden)

    Vladimir Zucha

    2005-01-01

    Full Text Available Efficieney of two deconvolution methods used in X-ray powder diffraction analysis is compared for thin films of Pd and Pt. The first method is the classical Stokes method and the second one is method of indirect deconvolution. But calculated integral breadth of Gauss and Cauchy components of Voigt function which describe the physical broadening are different. The analysis of the all found pheromones show that the method of indirect deconvolution gives more accurate results.

  14. Bi-layer Channel AZO/ZnO Thin Film Transistors Fabricated by Atomic Layer Deposition Technique.

    Science.gov (United States)

    Li, Huijin; Han, Dedong; Liu, Liqiao; Dong, Junchen; Cui, Guodong; Zhang, Shengdong; Zhang, Xing; Wang, Yi

    2017-12-01

    This letter demonstrates bi-layer channel Al-doped ZnO/ZnO thin film transistors (AZO/ZnO TFTs) via atomic layer deposition process at a relatively low temperature. The effects of annealing in oxygen atmosphere at different temperatures have also been investigated. The ALD bi-layer channel AZO/ZnO TFTs annealed in dry O2 at 300 °C exhibit a low leakage current of 2.5 × 10(-13)A, I on/I off ratio of 1.4 × 10(7), subthreshold swing (SS) of 0.23 V/decade, and high transmittance. The enhanced performance obtained from the bi-layer channel AZO/ZnO TFT devices is explained by the inserted AZO front channel layer playing the role of the mobility booster.

  15. Relating performance of thin-film composite forward osmosis membranes to support layer formation and structure

    KAUST Repository

    Tiraferri, Alberto

    2011-02-01

    Osmotically driven membrane processes have the potential to treat impaired water sources, desalinate sea/brackish waters, and sustainably produce energy. The development of a membrane tailored for these processes is essential to advance the technology to the point that it is commercially viable. Here, a systematic investigation of the influence of thin-film composite membrane support layer structure on forward osmosis performance is conducted. The membranes consist of a selective polyamide active layer formed by interfacial polymerization on top of a polysulfone support layer fabricated by phase separation. By systematically varying the conditions used during the casting of the polysulfone layer, an array of support layers with differing structures was produced. The role that solvent quality, dope polymer concentration, fabric layer wetting, and casting blade gate height play in the support layer structure formation was investigated. Using a 1M NaCl draw solution and a deionized water feed, water fluxes ranging from 4 to 25Lm-2h-1 with consistently high salt rejection (>95.5%) were produced. The relationship between membrane structure and performance was analyzed. This study confirms the hypothesis that the optimal forward osmosis membrane consists of a mixed-structure support layer, where a thin sponge-like layer sits on top of highly porous macrovoids. Both the active layer transport properties and the support layer structural characteristics need to be optimized in order to fabricate a high performance forward osmosis membrane. © 2010 Elsevier B.V.

  16. BAlN thin layers for deep UV applications

    Energy Technology Data Exchange (ETDEWEB)

    Li, Xin; Voss, Paul L.; Ougazzaden, Abdallah [School of Electrical and Computer Engineering, Georgia Institute of Technology, Metz (France); UMI 2958, Georgia Tech-CNRS, Metz (France); Sundaram, Suresh; El Gmili, Youssef; Moudakir, Tarik [UMI 2958, Georgia Tech-CNRS, Metz (France); Genty, Frederic [Supelec, LMOPS, EA 4423, Metz (France); Bouchoule, Sophie; Patriarche, Gilles [LPN CNRS, UPR20, Marcoussis (France); Dupuis, Russell D. [Center for Compound Semiconductors and School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, GA (United States); Salvestrini, Jean-Paul [UMI 2958, Georgia Tech-CNRS, Metz (France); Universite de Lorraine, LMOPS, EA 4423, Metz (France)

    2015-04-01

    In this work, wurtzite BAlN layers with boron composition as high as 12% were successfully grown by MOVPE. The growth was performed at 650 C and then annealed at 1020 C. Low temperature growth was used in order to alleviate B-rich phase poisoning under high TEB/III ratio. The growth was performed by continuous epitaxy as well as by flow-modulate epitaxy. BAlN single layers with clearly defined X-ray diffraction peaks were achieved on AlN templates which are appropriate substrates for deep UV devices, as well as on GaN templates to facilitate distinguishing of the XRD peak of BAlN from the substrate peak. The layer demonstrated columnar crystalline features and inherited wurtzite structure from substrates. Cross-section STEM image (bright field) of 75 nm thick BAlN layers containing 12% boron taken along the [11-2 0] zone axis. Zone A is lattice-oriented along c-axis and zone B has columnar structure; (b) higher magnification image for the top part of the layer; (c) higher magnification image for the film/substrate interface. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  17. Multi-layer boron thin-film detectors for neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Zhehui [Los Alamos National Laboratory; Morris, Christopher L [Los Alamos National Laboratory

    2010-01-01

    Intrinsic efficiencies of the multilayer boron detectors have been examined both theoretically and experimentally. It is shown that due to the charge loss in the boron layers, the practical efficiencies of most multi-layer {sup 10}B detectors are limited up to about 42%, much less than 77% of the 2 bar 2-inch diameter {sup 3}He detectors. It is suggested that the same charge loss mechanism will prevent essentially all substrate-based boron detectors from ever reaching the efficiencies of high-pressure {sup 3}He tubes, independent of the substrate geometry and material composition (including silicon). Meanwhile, the experimental data indicate that the multi-layer approach can increase the efficiencies up to the theoretical limit. Good n/{gamma} discrimination has also achieved using the ionization charnber technique.

  18. Crystallization study of amorphous sputtered NiTi bi-layer thin film

    Energy Technology Data Exchange (ETDEWEB)

    Mohri, Maryam, E-mail: mmohri@ut.ac.ir [School of Metallurgy and Materials Engineering, College of Engineering, University of Tehran, Tehran (Iran, Islamic Republic of); Karlsruhe Institute of Technology, Institute of Nanotechnology, 76021 Karlsruhe (Germany); Nili-Ahmadabadi, Mahmoud [School of Metallurgy and Materials Engineering, College of Engineering, University of Tehran, Tehran (Iran, Islamic Republic of); Center of Excellence for High Performance Materials, University of Tehran, Tehran (Iran, Islamic Republic of); Chakravadhanula, Venkata Sai Kiran [Karlsruhe Institute of Technology, Institute of Nanotechnology, 76021 Karlsruhe (Germany)

    2015-05-15

    The crystallization of Ni-rich/NiTiCu bi-layer thin film deposited by magnetron sputtering from two separate alloy targets was investigated. To achieve the shape memory effect, the NiTi thin films deposited at room temperature with amorphous structure were annealed at 773 K for 15, 30, and 60 min for crystallization. Characterization of the films was carried out by differential scanning calorimetry to indicate the crystallization temperature, grazing incidence X-ray diffraction to identify the phase structures, atomic force microscopy to evaluate surface morphology, scanning transmission electron microscopy to study the cross section of the thin films. The results show that the structure of the annealed thin films strongly depends on the temperature and time of the annealing. Crystalline grains nucleated first at the surface and then grew inward to form columnar grains. Furthermore, the crystallization behavior was markedly affected by composition variations. - Highlights: • A developed bi-layer Ni45TiCu5/Ni50.8Ti was deposited on Si substrate and crystallized. • During crystallization, The Ni{sub 45}TiCu{sub 5} layer is thermally less stable than the Ni-rich layer. • The activation energy is 302 and 464 kJ/mol for Cu-rich and Ni-rich layer in bi-layer, respectively.

  19. Perpendicular magnetic tunnel junction with thin CoFeB/Ta/Co/Pd/Co reference layer

    Energy Technology Data Exchange (ETDEWEB)

    Gan, Huadong, E-mail: huadong@avalanche-technology.com; Malmhall, Roger; Wang, Zihui; Yen, Bing K; Zhang, Jing; Wang, Xiaobin; Zhou, Yuchen; Hao, Xiaojie; Jung, Dongha; Satoh, Kimihiro; Huai, Yiming [Avalanche Technology, 46600 Landing Parkway, Fremont, California 94538 (United States)

    2014-11-10

    Integration of high density spin transfer torque magnetoresistance random access memory requires a thin stack (less than 15 nm) of perpendicular magnetic tunnel junction (p-MTJ). We propose an innovative approach to solve this challenging problem by reducing the thickness and/or moment of the reference layer. A thin reference layer structure of CoFeB/Ta/Co/Pd/Co has 60% magnetic moment of the conventional thick structure including [Co/Pd] multilayers. We demonstrate that the perpendicular magnetization of the CoFeB/Ta/Co/Pd/Co structure can be realized by anti-ferromagnetically coupling to a pinned layer with strong perpendicular anisotropy via Ruderman-Kittel-Kasuya-Yosida exchange interaction. The pMTJ with thin CoFeB/Ta/Co/Pd/Co reference layer has a comparable TMR ratio (near 80%) as that with thick reference layer after annealing at 280 °C. The pMTJ with thin reference layer has a total thickness less than 15 nm, thereby significantly increasing the etching margin required for integration of high density pMTJ array on wafers with form factor of 300 mm and beyond.

  20. Computationally efficient parabolic equation solutions to seismo-acoustic problems involving thin or low-shear elastic layers.

    Science.gov (United States)

    Metzler, Adam M; Collis, Jon M

    2013-04-01

    Shallow-water environments typically include sediments containing thin or low-shear layers. Numerical treatments of these types of layers require finer depth grid spacing than is needed elsewhere in the domain. Thin layers require finer grids to fully sample effects due to elasticity within the layer. As shear wave speeds approach zero, the governing system becomes singular and fine-grid spacing becomes necessary to obtain converged solutions. In this paper, a seismo-acoustic parabolic equation solution is derived utilizing modified difference formulas using Galerkin's method to allow for variable-grid spacing in depth. Propagation results are shown for environments containing thin layers and low-shear layers.

  1. Surface structure of thin pseudomorphous GeSi layers

    Science.gov (United States)

    Nikiforov, A. I.; Timofeev, V. F.; Pchelyakov, O. P.

    2015-11-01

    Reflection high-energy electron diffraction (RHEED) was used to study the evolution of thin GexSi1-x film surface superstructures s in the course of molecular beam epitaxy. The (2 × N) superstructure of the epitaxial film surface at periodicity N from 14 to 8, the latter being characteristic of pure germanium at the Si(1 0 0) surface. The epitaxial film thickness that is required for the formation of the (2 × 8) superstructure depends on the deposition temperature and germanium content in the solid solution. The germanium segregation on the growing film surface is shown to be responsible for the observed superstructural changes.

  2. Deposition of thin insulation layers from the gas phase

    Science.gov (United States)

    Behn, R.; Hagedorn, H.; Kammermaier, J.; Kobale, M.; Packonik, H.; Ristow, D.; Seebacher, G.

    1981-01-01

    The continuous deposition of thin organic dielectric films on metallized carrier foils by glow discharge in monomeric gases is described. Depending on the applied monomers, the films had a dissipation factor of .001 to .003 (1 kHz), a relative permittivity of 2.3 to 2.5 and a resistivity of about 10 to the 17th power omega cm. Additionally, they proved to have a high mechanical homogeneity. Self-healing rolled capacitors with a very high capacitance per volume and of consistently high quality were fabricated from the metallized carrier foils covered with the dielectric film.

  3. Controlled nucleation and growth of thin hydroxyapatite layers on titanium implants by using induction heating technique.

    Science.gov (United States)

    Gómez Morales, J; Rodríguez Clemente, R; Armas, B; Combescure, C; Berjoan, R; Cubo, J; Martínez, E; García Carmona, J; Garelik, S; Murtra, J; Muraviev, D N

    2004-06-22

    This paper reports the results obtained by the development of a new wet method of hydroxyapatite (HA) thin layer deposition. The method is based on the localized precipitation of HA on metallic substrates activated by induction heating. The technique developed has been shown to allow for the complete coating of substrates with micrometric thin films of HA within a low processing time. The method has been successfully applied to coat Ti plaques and Ti-6A1-4V cylinders.

  4. Electrospun nanofiber layers with incorporated photoluminescence indicator for chromatography and detection of ultraviolet-active compounds.

    Science.gov (United States)

    Kampalanonwat, Pimolpun; Supaphol, Pitt; Morlock, Gertrud E

    2013-07-19

    For the first time, electrospun nanofiber phases were fabricated with manganese-activated zinc silicate as photoluminescent indicator (UV254) to transfer and enlarge its application to the field of UV-active compounds. By integration of such an indicator, UV-active compounds got visible on the chromatogram. The separation of 7 preservatives and a beverage sample were studied on the novel luminescent polyacrylonitrile layers. The mat thickness and mean fiber diameters were calculated for additions of different UV254 indicator concentrations. The separation efficiency on the photoluminescent layers was characterized by comparison to HPTLC layers and calculation of the plate numbers and resolutions. Some benefits were the reduction in migration distance (3cm), migration time (12min), analyte (10-nL volumes) and mobile phase volumes (1mL). As ultrathin stationary phase, such layers are suited for their integration into the Office Chromatography concept. For the first time, electrospun nanofiber layers were hyphenated with mass spectrometry and the confirmation of compounds was successfully performed using the elution-head based TLC-MS Interface.

  5. The effects of layering in ferroelectric Si-doped HfO2 thin films

    Science.gov (United States)

    Lomenzo, Patrick D.; Takmeel, Qanit; Zhou, Chuanzhen; Liu, Yang; Fancher, Chris M.; Jones, Jacob L.; Moghaddam, Saeed; Nishida, Toshikazu

    2014-08-01

    Atomic layer deposited Si-doped HfO2 thin films approximately 10 nm thick are deposited with various Si-dopant concentrations and distributions. The ferroelectric behavior of the HfO2 thin films are shown to be dependent on both the Si mol. % and the distribution of Si-dopants. Metal-ferroelectric-insulator-semiconductor capacitors are shown to exhibit a tunable remanent polarization through the adjustment of the Si-dopant distribution at a constant Si concentration. Inhomogeneous layering of Si-dopants within the thin films effectively lowers the remanent polarization. A pinched hysteresis loop is observed for higher Si-dopant concentrations and found to be dependent on the Si layering distribution.

  6. Thin layer microcolony culture associated with PCR for early identification of Mycobacterium bovis

    Directory of Open Access Journals (Sweden)

    Tatiana Reis do Rosário

    2014-01-01

    Full Text Available The initial growth of mycobacteria from 49 samples of cattle and buffalo organs collected in commercial slaughterhouses was compared between modified Middlebrook 7H11 thin layer microcolony culture and Stonebrink medium used in the isolation of Mycobacterium bovis. Aliquots were decontaminated by Petroff's method, processed and cultured in both media. The identity of the acid-fast bacilli stained by Ziehl-Neelsen was confirmed by PCR. Optical microscopy showed that results of the early observation of Mycobacterium bovis colonies in thin layer culture were similar to those obtained in macroscopic observation of the colonies in Stonebrink medium. However, early observation of the colonies enabled early confirmation by PCR, given the shorter time to the visualization of colonies when thin layer culture was used (between the 12nd and 25th day of culture.

  7. Thin layer drying of cassava starch using continuous vibrated fluidized bed dryer

    Science.gov (United States)

    Suherman, Trisnaningtyas, Rona

    2015-12-01

    This paper present the experimental work and thin layer modelling of cassava starch drying in continuous vibrated fluidized bed dryer. The experimental data was used to validate nine thin layer models of drying curve. Cassava starch with 0.21 initial moisture content was dried in different air drying temperature (50°C, 55°C, 60°C, 65°C, 70°C), different weir height in bed (0 and 1 cm), and different solid feed flow (10 and 30 gr.minute-1). The result showed air dryer temperature has a significant effect on drying curve, while the weir height and solid flow rate are slightly. Based on value of R2, χ2, and RMSE, Page Model is the most accurate simulation for thin layer drying model of cassava starch.

  8. Interfacial double layer mediated electrochemical growth of thin-walled platinum nanotubes

    Science.gov (United States)

    Zhang, Liqiu; Kim, Sang Min; Cho, Sanghyun; Jang, Hee-Jeong; Liu, Lichun; Park, Sungho

    2017-01-01

    This work demonstrates that thin-walled platinum nanotubes can be readily synthesized by controlling the interfacial double layer in alumina nanochannels. The gradient distribution of ions in nanochannels enables the creation of Pt nanotubes with walls as thin as 5 nm at the top end when using a solution containing polyvinylpyrrolidone (PVP) and chloroplatinic acid (H2PtCl6) under the influence of an electric potential in nanochannels. The highly efficient formation of thin-walled Pt nanotubes is a result of the concentration gradient of {{{{PtCl}}}6}2- and a thick double layer, which was caused by the low concentration of Pt precursors and the enhanced surface charge density induced by protonated PVP steric adsorption. This well-controlled synthesis reveals that the interfacial double layer is a useful tool to tailor the structure of nanomaterials in a nanoscale space, and holds promise in the construction of more complex functional nanostructures.

  9. Determination of thin layer thickness from alpha particle energy spectra

    Energy Technology Data Exchange (ETDEWEB)

    Hnatowicz, V.; Kvitek, J. (Ceskoslovenska Akademie Ved, Prague. Ustav pro Elektrotechniku); Rybka, V.; Krejci, P. (Tesla, Prague (Czechoslovakia). Vyzkumny Ustav pro Sdelovaci Techniku); Pelikan, L. (Ceske Vysoke Uceni Technicke, Prague (Czechoslovakia). Fakulta Elektrotechnicka); Mikusik, P. (Ceskoslovenska Akademie Ved, Prague. Ustav Fyzikalni Chemie a Elektrochemie J. Heyrovskeho)

    1982-10-01

    A method which uses alpha particles from the /sup 10/B(n,alpha)/sup 7/Li nuclear reaction for the determination of surface layer thicknesses is described and experimentally checked. The thickness measurements can be performed on samples implanted with boron.

  10. Enhanced second harmonic generation of MoS2 layers on a thin gold film.

    Science.gov (United States)

    Zeng, Jianhua; Yuan, Maohui; Yuan, Weiguang; Dai, Qiaofeng; Fan, Haihua; Lan, Sheng; Tie, Shaolong

    2015-08-28

    The linear and nonlinear optical properties of thin MoS2 layers exfoliated on an Au/SiO2 substrate were investigated both numerically and experimentally. It was found that the MoS2 layers with different thicknesses exhibited different colors on the gold film. The reflection spectra of the MoS2 layers with different thicknesses were calculated by using the finite-difference time-domain technique and the corresponding chromaticity coordinates were derived. The electric field enhancement factors at both the fundamental light and the second harmonic were calculated and the enhancement factors for second harmonic generation (SHG) were estimated for the MoS2 layers with different thicknesses. Different from the MoS2 layers on a SiO2/Si substrate where the maximum SHG was observed in the single-layer MoS2, the maximum SHG was achieved in the 17 nm-thick MoS2 layer on the Au/SiO2 substrate. As compared with the MoS2 layers on the SiO2/Si substrate, a significant enhancement in SHG was found for the MoS2 layers on the Au/SiO2 substrate due to the strong localization of the electric field. More interestingly, it was demonstrated experimentally that optical data storage can be realized by modifying the SHG intensity of a MoS2 layer through thinning its thickness.

  11. Enhanced electrical properties of oxide semiconductor thin-film transistors with high conductivity thin layer insertion for the channel region

    Science.gov (United States)

    Nguyen, Cam Phu Thi; Raja, Jayapal; Kim, Sunbo; Jang, Kyungsoo; Le, Anh Huy Tuan; Lee, Youn-Jung; Yi, Junsin

    2017-02-01

    This study examined the performance and the stability of indium tin zinc oxide (ITZO) thin film transistors (TFTs) by inserting an ultra-thin indium tin oxide (ITO) layer at the active/insulator interface. The electrical properties of the double channel device (ITO thickness of 5 nm) were improved in comparison with the single channel ITZO or ITO devices. The TFT characteristics of the device with an ITO thickness of less than 5 nm were degraded due to the formation of an island-like morphology and the carriers scattering at the active/insulator interface. The 5 nm-thick ITO inserted ITZO TFTs (optimal condition) exhibited a superior field effect mobility (∼95 cm2/V·s) compared with the ITZO-only TFTs (∼34 cm2/V·s). The best characteristics of the TFT devices with double channel layer are due to the lowest surface roughness (0.14 nm) and contact angle (50.1°) that result in the highest hydrophicility, and the most effective adhesion at the surface. Furthermore, the threshold voltage shifts for the ITO/ITZO double layer device decreased to 0.80 and -2.39 V compared with 6.10 and -6.79 V (for the ITZO only device) under positive and negative bias stress, respectively. The falling rates of EA were 0.38 eV/V and 0.54 eV/V for the ITZO and ITO/ITZO bi-layer devices, respectively. The faster falling rate of the double channel devices suggests that the trap density, including interface trap and semiconductor bulk trap, can be decreased by the ion insertion of a very thin ITO film into the ITZO/SiO2 reference device. These results demonstrate that the double active layer TFT can potentially be applied to the flat panel display.

  12. Structural, morphology and electrical properties of layered copper selenide thin film

    Science.gov (United States)

    Ying Chyi Liew, J.; Talib, Zainal; Mahmood, W.; Yunus, M.; Zainal, Zulkarnain; Halim, Shaari; Moksin, Mohd; Yusoff, Wan; Pah Lim, K.

    2009-06-01

    Thin films of copper selenide (CuSe) were physically deposited layer-by-layer up to 5 layers using thermal evaporation technique onto a glass substrate. Various film properties, including the thickness, structure, morphology, surface roughness, average grain size and electrical conductivity are studied and discussed. These properties are characterized by X-ray diffraction (XRD), atomic force microscopy (AFM), ellipsometer and 4 point probe at room temperature. The dependence of electrical conductivity, surface roughness, and average grain size on number of layers deposited is discussed.

  13. Drift of scroll waves in thin layers caused by thickness features: asymptotic theory and numerical simulations.

    Science.gov (United States)

    Biktasheva, I V; Dierckx, H; Biktashev, V N

    2015-02-13

    A scroll wave in a very thin layer of excitable medium is similar to a spiral wave, but its behavior is affected by the layer geometry. We identify the effect of sharp variations of the layer thickness, which is separate from filament tension and curvature-induced drifts described earlier. We outline a two-step asymptotic theory describing this effect, including asymptotics in the layer thickness and calculation of the drift of so-perturbed spiral waves using response functions. As specific examples, we consider drift of scrolls along thickness steps, ridges, ditches, and disk-shaped thickness variations. Asymptotic predictions agree with numerical simulations.

  14. Low Energy Scanned Electron-Beam Dose Distribution in Thin Layers

    DEFF Research Database (Denmark)

    McLaughlin, W. L.; Hjortenberg, P. E.; Pedersen, Walther Batsberg

    1975-01-01

    Thin radiochromic dye film dosimeters, calibrated by means of calorimetry, make possible the determination of absorbed-dose distributions due to low-energy scanned electron beam penetrations in moderately thin coatings and laminar media. For electrons of a few hundred keV, calibrated dosimeters...... of about 30–60 μm thickness may be used in stacks or interleaved between layers of materials of interest and supply a sufficient number of experimental data points throughout the depth of penetration of electrons to provide a depth-dose curve. Depth doses may be resolved in various polymer layers...

  15. STUDY ON DETERMINATION OF TRACE Fe BY Fe(Ⅱ)-VA THIN LAYER RESIN PHASE SPECTROPHOTOMETRY

    Institute of Scientific and Technical Information of China (English)

    SONG Huanyu; YAN Yongsheng; WANG Yun

    2006-01-01

    A new method for the determination of Fe by thin layer resin phase spectrophotometry in alkali condition was reported. The complex anion formed by Fe(Ⅱ) and VA was absorbed on the 717#resin and Fe was determined by making thin layer. This method had a high sensitivity (ε620=3.0×105 L/mol·cm), which was 15 times higher than that of liquid phase spectrophotometry. It had been proved a satisfactory precision (5.0μg Fe, n=6, RSD=1.8%). The trace Fe in natural water was determined and the recovery was 97%.

  16. Anti-fogging and anti-frosting behaviors of layer-by-layer assembled cellulose derivative thin film

    Science.gov (United States)

    Shibraen, Mahmoud H. M. A.; Yagoub, Hajo; Zhang, Xuejian; Xu, Jian; Yang, Shuguang

    2016-05-01

    Two cellulose derivatives, quaternized cellulose (QC) and carboxymethyl cellulose (CMC), were layer-by-layer (LbL) assembled to prepare a thin film. QC was also LbL assembled with two synthetic polyelectrolytes, poly(acrylic acid) (PAA) and poly(styrene sulfonate) (PSS), separately. The anti-fogging and anti-frosting properties of the assembled films were studied. QC/CMC thin film exhibits anti-fogging and anti-frosting behaviors, whereas QC/PAA and QC/PSS films do not have capacity for anti-fogging and anti-frosting. The anti-fogging and anti-frosting properties of QC/CMC film are attributed to that water molecules can be quickly adsorbed into the matrix of the film. The water adsorption of QC/CMC film was illustrated by the optical thickness increment.

  17. Monolithic growth of partly cured polydimethylsiloxane thin film layers

    DEFF Research Database (Denmark)

    Yu, Liyun; Skov, Anne Ladegaard

    2014-01-01

    to enable interlayer crosslinking reactions either by application of an adhesion promoter or by ensuring that there are reactive, complementary sites available on the two surfaces. Polydimethylsiloxane (PDMS) is a widely used polymer for DEAPs. In this work, two-layered PDMS films are adhered together...... at different curing times. The monolithic films are investigated by rheology, scanning electron microscope, mechanical testing, dielectric relaxation spectroscopy, thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC). The morphology, mechanical and dielectric properties, as well...... as thermal stabilities of the bilayer elastomer films are observed to change with the curing time of the monolayers before lamination. The objective of this work is to create adhesion of two layers without destroying the original viscoelastic properties of the PDMS films, and hence enable, for example...

  18. Ultraviolet laser deposition of graphene thin films without catalytic layers

    KAUST Repository

    Sarath Kumar, S. R.

    2013-01-09

    In this letter, the formation of nanostructured graphene by ultraviolet laser ablation of a highly ordered pyrolytic graphite target under optimized conditions is demonstrated, without a catalytic layer, and a model for the growth process is proposed. Previously, graphene film deposition by low-energy laser (2.3 eV) was explained by photo-thermal models, which implied that graphene films cannot be deposited by laser energies higher than the C-C bond energy in highly ordered pyrolytic graphite (3.7 eV). Here, we show that nanostructured graphene films can in fact be deposited using ultraviolet laser (5 eV) directly over different substrates, without a catalytic layer. The formation of graphene is explained by bond-breaking assisted by photoelectronic excitation leading to formation of carbon clusters at the target and annealing out of defects at the substrate.

  19. Spotting 2D atomic layers on aluminum nitride thin films.

    Science.gov (United States)

    Chandrasekar, Hareesh; Bharadwaj B, Krishna; Vaidyuala, Kranthi Kumar; Suran, Swathi; Bhat, Navakanta; Varma, Manoj; Srinivasan Raghavan

    2015-10-23

    Substrates for 2D materials are important for tailoring their fundamental properties and realizing device applications. Aluminum nitride (AIN) films on silicon are promising large-area substrates for such devices in view of their high surface phonon energies and reasonably large dielectric constants. In this paper epitaxial layers of AlN on 2″ Si wafers have been investigated as a necessary first step to realize devices from exfoliated or transferred atomic layers. Significant thickness dependent contrast enhancements are both predicted and observed for monolayers of graphene and MoS2 on AlN films as compared to the conventional SiO2 films on silicon, with calculated contrast values approaching 100% for graphene on AlN as compared to 8% for SiO2 at normal incidences. Quantitative estimates of experimentally measured contrast using reflectance spectroscopy show very good agreement with calculated values. Transistors of monolayer graphene on AlN films are demonstrated, indicating the feasibility of complete device fabrication on the identified layers.

  20. Analysis of layer-by-layer thin-film oxide growth using RHEED and Atomic Force Microscopy

    Science.gov (United States)

    Adler, Eli; Sullivan, M. C.; Gutierrez-Llorente, Araceli; Joress, H.; Woll, A.; Brock, J. D.

    2015-03-01

    Reflection high energy electron diffraction (RHEED) is commonly used as an in situ analysis tool for layer-by-layer thin-film growth. Atomic force microscopy is an equally common ex situ tool for analysis of the film surface, providing visual evidence of the surface morphology. During growth, the RHEED intensity oscillates as the film surface changes in roughness. It is often assumed that the maxima of the RHEED oscillations signify a complete layer, however, the oscillations in oxide systems can be misleading. Thus, using only the RHEED maxima is insufficient. X-ray reflectivity can also be used to analyze growth, as the intensity oscillates in phase with the smoothness of the surface. Using x-ray reflectivity to determine the thin film layer deposition, we grew three films where the x-ray and RHEED oscillations were nearly exactly out of phase and halted deposition at different points in the growth. Pre-growth and post-growth AFM images emphasize the fact that the maxima in RHEED are not a justification for determining layer completion. Work conducted at the Cornell High Energy Synchrotron Source (CHESS) supported by NSF Awards DMR-1332208 and DMR-0936384 and the Cornell Center for Materials Research Shared Facilities are supported through DMR-1120296.

  1. Fullerenes as adhesive layers for mechanical peeling of metallic, molecular and polymer thin films.

    Science.gov (United States)

    Wieland, Maria B; Slater, Anna G; Mangham, Barry; Champness, Neil R; Beton, Peter H

    2014-01-01

    We show that thin films of C60 with a thickness ranging from 10 to 100 nm can promote adhesion between a Au thin film deposited on mica and a solution-deposited layer of the elastomer polymethyldisolaxane (PDMS). This molecular adhesion facilitates the removal of the gold film from the mica support by peeling and provides a new approach to template stripping which avoids the use of conventional adhesive layers. The fullerene adhesion layers may also be used to remove organic monolayers and thin films as well as two-dimensional polymers which are pre-formed on the gold surface and have monolayer thickness. Following the removal from the mica support the monolayers may be isolated and transferred to a dielectric surface by etching of the gold thin film, mechanical transfer and removal of the fullerene layer by annealing/dissolution. The use of this molecular adhesive layer provides a new route to transfer polymeric films from metal substrates to other surfaces as we demonstrate for an assembly of covalently-coupled porphyrins.

  2. Design of a 1200-V Thin-Silicon-Layer p-Channel SOI LDMOS Device

    Institute of Scientific and Technical Information of China (English)

    胡盛东; 张玲; 罗小蓉; 张波; 李肇基; 吴丽娟

    2011-01-01

    A 1200-V thin-silicon-layer p-channel silicon-on-insulator(SOI)lateral double-diffused metal-oxide-semiconductor (LDMOS)transistor is designed.The device named INI SO1 p-LDMOS is characterized by a series of equidistant high concentration n+ islands inserted at the interface of a top silicon layer and a buried oxide layer.Accumulation-mode holes,caused by the electric potential dispersion between the device surface and the substrate,are located in the spacing between two neighboring n+ islands,and greatly enhance the electric field of the buried oxide layer and therefore,effectively increase the device breakdown voltage.Based on a 2-μm-thick buried oxide layer and a 1.5-μm-thick top silicon layer,a breakdown voltage of 1224 V is obtained,resulting in the high electric field(608 V/μm)of the buried oxide layer.%A 1200-V thin-silicon-layer p-channel silicon-on-insulator (SOI) lateral double-diffused metal-oxide-semiconductor (LDMOS) transistor is designed. The device named INI SOI p-LDMOS is characterized by a series of equidistant high concentration n+ islands inserted at the interface of a top silicon layer and a buried oxide layer. Accumulation-mode holes, caused by the electric potential dispersion between the device surface and the substrate, are located in the spacing between two neighboring n+ islands, and greatly enhance the electric field of the buried oxide layer and therefore, effectively increase the device breakdown voltage. Based on a 2-[im-thick buried oxide layer and a 1.5-um-thick top silicon layer, a breakdown voltage of 1224 V is obtained, resulting in the high electric field (608 V/\\im) of the buried oxide layer.

  3. Uniaxially aligned electrospun cellulose acetate nanofibers for thin layer chromatographic screening of hydroquinone and retinoic acid adulterated in cosmetics.

    Science.gov (United States)

    Tidjarat, Siripran; Winotapun, Weerapath; Opanasopit, Praneet; Ngawhirunpat, Tanasait; Rojanarata, Theerasak

    2014-11-01

    Uniaxially aligned cellulose acetate (CA) nanofibers were successfully fabricated by electrospinning and applied to use as stationary phase for thin layer chromatography. The control of alignment was achieved by using a drum collector rotating at a high speed of 6000 rpm. Spin time of 6h was used to produce the fiber thickness of about 10 μm which was adequate for good separation. Without any chemical modification after the electrospinning process, CA nanofibers could be readily devised for screening hydroquinone (HQ) and retinoic acid (RA) adulterated in cosmetics using the mobile phase consisting of 65:35:2.5 methanol/water/acetic acid. It was found that the separation run on the aligned nanofibers over a distance of 5 cm took less than 15 min which was two to three times faster than that on the non-aligned ones. On the aligned nanofibers, the masses of HQ and RA which could be visualized were 10 and 25 ng, respectively, which were two times lower than those on the non-aligned CA fibers and five times lower than those on conventional silica plates due to the appearance of darker and sharper of spots on the aligned nanofibers. Furthermore, the proposed method efficiently resolved HQ from RA and ingredients commonly found in cosmetic creams. Due to the satisfactory analytical performance, facile and inexpensive production process, uniaxially aligned electrospun CA nanofibers are promising alternative media for planar chromatography.

  4. Stabilisation of the amorphous state of a thin layer sandwiched between two crystals

    Energy Technology Data Exchange (ETDEWEB)

    Hyot, B.; Poupinet, L.; Desre, P.J

    2003-11-01

    It has been experimentally proven that thinning an amorphous layer, sandwiched between two crystals, up to the nanometer scale, leads to a higher crystallization temperature. The present work is an attempt to explain such behaviour on the basis of thermodynamical arguments. The approach assumes that a nanometric amorphous layer is submitted to the crystal field leading to a gradient of atomic density across the glassy layer. It is shown that the stabilisation of the glassy layer is expected when approaching a thickness of few nanometers. This study is closely related to the concerns of the phase change optical storage because such a technology involves both the use of very thin films and fast structural transitions between the two states (amorphous and crystalline) of the active material.

  5. Enhancement of absorption in vertically-oriented graphene sheets growing on a thin copper layer

    Science.gov (United States)

    Rozouvan, Tamara; Poperenko, Leonid; Kravets, Vasyl; Shaykevich, Igor

    2017-02-01

    The optical properties and surface structure of graphene films grown on thin copper Cu (1 μm) layer using chemical vapour deposition method were investigated via spectroscopic ellipsometry and nanoscopic measurements. Angle variable ellipsometry measurements were performed to analyze the features of dispersion of the complex refractive index and optical conductivity. It was observed significant enhancement of the absorption band in the vertically-oriented graphene sheets layer with respect to the bulk graphite due to interaction between excited localized surface plasmon at surface of thin Cu layer and graphene's electrons. Scanning tunneling microscopy measurements with atomic spatial resolution revealed vertical crystal lattice structure of the deposited graphene layer. The obtained results provide direct evidence of the strong influence of the growing condition and morphology of nanostructure on electronic and optical behaviours of graphene film.

  6. Transmission electron microscopy study on ion-beam-synthesized amorphous Fe-Si thin layers

    Science.gov (United States)

    Naito, Muneyuki; Ishimaru, Manabu; Hirotsu, Yoshihiko; Valdez, James A.; Sickafus, Kurt E.

    2005-12-01

    Ion-beam-synthesized amorphous Fe-Si thin layers have been characterized using transmission electron microscopy (TEM) in combination with imaging plate techniques. Si single crystals with a (111) orientation were irradiated with 120keV Fe+ ions to a fluence of 4.0×1017cm-2 at cryogenic temperature (120K). Cross-sectional TEM observations indicated the formation of an amorphous bilayer on the topmost layer of the Si substrate. It was found that the upper layer is an amorphous Fe-Si with the composition, in terms of atomic ratio, of Fe /Si ˜1/2, while the lower one is an amorphous Si. Atomic pair-distribution functions extracted from microbeam electron diffraction patterns revealed that the nature of short-range order in amorphous Fe-Si thin layer can be well described by the atomic arrangements of crystalline iron silicides.

  7. Epitaxially grown polycrystalline silicon thin-film solar cells on solid-phase crystallised seed layers

    Energy Technology Data Exchange (ETDEWEB)

    Li, Wei, E-mail: weili.unsw@gmail.com; Varlamov, Sergey; Xue, Chaowei

    2014-09-30

    Highlights: • Crystallisation kinetic is used to analyse seed layer surface cleanliness. • Simplified RCA cleaning for the seed layer can shorten the epitaxy annealing duration. • RTA for the seed layer can improve the quality for both seed layer and epi-layer. • Epitaxial poly-Si solar cell performance is improved by RTA treated seed layer. - Abstract: This paper presents the fabrication of poly-Si thin film solar cells on glass substrates using seed layer approach. The solid-phase crystallised P-doped seed layer is not only used as the crystalline template for the epitaxial growth but also as the emitter for the solar cell structure. This paper investigates two important factors, surface cleaning and intragrain defects elimination for the seed layer, which can greatly influence the epitaxial grown solar cell performance. Shorter incubation and crystallisation time is observed using a simplified RCA cleaning than the other two wet chemical cleaning methods, indicating a cleaner seed layer surface is achieved. Cross sectional transmission microscope images confirm a crystallographic transferal of information from the simplified RCA cleaned seed layer into the epi-layer. RTA for the SPC seed layer can effectively eliminate the intragrain defects in the seed layer and improve structural quality of both of the seed layer and the epi-layer. Consequently, epitaxial grown poly-Si solar cell on the RTA treated seed layer shows better solar cell efficiency, V{sub oc} and J{sub sc} than the one on the seed layer without RTA treatment.

  8. Squeezing molecularly thin alkane lubrication films: Layering transistions and wear

    DEFF Research Database (Denmark)

    Sivebæk, Ion Marius; Samoilov, V. N.; Persson, B. N. J.

    2004-01-01

    The properties of alkane lubricants confined between two approaching solids are investigated by a model that accounts for the curvature and the elastic properties of the solid surfaces. We consider linear alkane molecules of different chain lengths, C(3)H(8); C(4)H(10); C(8)H(18); C(9)H(20); C(10)H......(22); C(12)H(26), and C(14)H(30) confined between smooth gold surfaces. We observe well-defined molecular layers develop in the lubricant film when the width of the film is of the order of a few atomic diameters. An external squeezing-pressure induces discontinuous changes in the number n of lubricant...

  9. Grazing Processes and the Structure and Persistence of Thin Biological Layers

    Science.gov (United States)

    1999-09-30

    technique and subsequent capture onto a black Nuclepore filter for epifluorescence microscopy preserves the colony’s gelatinous matrix. We are able to...However, the diatom’s gelatinous matrix is not preserved in aldehyde, preventing adequate processing of this important species in those samples. Obtaining...growth and loss) in and around thin layers and the first cm-scale profiles of nano- and micro- plankton collected in a layered coastal water column

  10. Confirmation of sublunarean voids and thin layering in mare deposits

    Science.gov (United States)

    Robinson, M. S.; Ashley, J. W.; Boyd, A. K.; Wagner, R. V.; Speyerer, E. J.; Ray Hawke, B.; Hiesinger, H.; van der Bogert, C. H.

    2012-08-01

    Typical flow thicknesses of lunar mare basalts were not well constrained in the past, because as craters and rilles age, downslope movement of loose material tends to mix and bury stratigraphy, obscuring the three dimensional nature of the maria. New Lunar Reconnaissance Orbiter Camera high resolution images unambiguously reveal thicknesses of mare basalt layers exposed in impact craters, rilles, and steep-walled pits. Pits up to one hundred meters deep present relatively unmodified, near-vertical sections of mare in three cases, and many young impact craters also expose well preserved sections of mare. Oblique views of each pit and many of these craters reveal multiple layers, 3 to 14 m thick, indicating that eruptions typically produced a series of ˜10 m thick flows (or flow lobes) rather than flows many tens to hundreds of meters thick. Additionally, these images unambiguously show that the floors of two pits extend beneath the mare surfaces, thus revealing sublunarean voids of unknown lateral extent. We also document the occurrence of pits that may be expressions of collapse into subsurface voids in non-mare impact melt deposits. These voids are compelling targets for future human and robotic exploration, with potential as temporary shelters, habitations, or geologic museums.

  11. Tandem organic light-emitting diode with a molybdenum tri-oxide thin film interconnector layer

    Institute of Scientific and Technical Information of China (English)

    Lu Fei-Ping; Wang Qian; Zhou Xiang

    2013-01-01

    A 10-nm-thick molybdenum tri-oxide (MoO3) thin film was used as the interconnector layer in tandem organic lightemitting devices (OLEDs).The tandem OLEDs with two identical emissive units consisting of N,N'-bis(naphthalen-1-yl)-N,N'-bis(phenyl)-benzidine (NPB) / tris(8-hydroxyquinoline) aluminum (Alq3) exhibited current efficiency-current density characteristics superior to the conventional single-unit devices.At 20 mA/cm2,the current efficiency of the tandem OLEDs using the interconnector layers of MoO3 thin film was about 4.0 cd/A,which is about twice that of the corresponding conventional single-unit device (1.8 cd/A).The tandem OLED showed a higher power efficiency than the conventional single-unit device for luminance over 1200 cd/m2.The experimental results demonstrated that a MoO3 thin film with a proper thickness can be used as an effective interconnector layer in tandem OLEDs.Such an interconnector layer can be easily fabricated by simple thermal evaporation,greatly simplifying the device processing and fabrication processes required by previously reported interconnector layers.A possible explanation was proposed for the carrier generation of the MoO3 interconnector layer.

  12. Epitaxially grown polycrystalline silicon thin-film solar cells on solid-phase crystallised seed layers

    Science.gov (United States)

    Li, Wei; Varlamov, Sergey; Xue, Chaowei

    2014-09-01

    This paper presents the fabrication of poly-Si thin film solar cells on glass substrates using seed layer approach. The solid-phase crystallised P-doped seed layer is not only used as the crystalline template for the epitaxial growth but also as the emitter for the solar cell structure. This paper investigates two important factors, surface cleaning and intragrain defects elimination for the seed layer, which can greatly influence the epitaxial grown solar cell performance. Shorter incubation and crystallisation time is observed using a simplified RCA cleaning than the other two wet chemical cleaning methods, indicating a cleaner seed layer surface is achieved. Cross sectional transmission microscope images confirm a crystallographic transferal of information from the simplified RCA cleaned seed layer into the epi-layer. RTA for the SPC seed layer can effectively eliminate the intragrain defects in the seed layer and improve structural quality of both of the seed layer and the epi-layer. Consequently, epitaxial grown poly-Si solar cell on the RTA treated seed layer shows better solar cell efficiency, Voc and Jsc than the one on the seed layer without RTA treatment.

  13. Nano-oxide thin films deposited via atomic layer deposition on microchannel plates.

    Science.gov (United States)

    Yan, Baojun; Liu, Shulin; Heng, Yuekun

    2015-01-01

    Microchannel plate (MCP) as a key part is a kind of electron multiplied device applied in many scientific fields. Oxide thin films such as zinc oxide doped with aluminum oxide (ZnO:Al2O3) as conductive layer and pure aluminum oxide (Al2O3) as secondary electron emission (SEE) layer were prepared in the pores of MCP via atomic layer deposition (ALD) which is a method that can precisely control thin film thickness on a substrate with a high aspect ratio structure. In this paper, nano-oxide thin films ZnO:Al2O3 and Al2O3 were prepared onto varied kinds of substrates by ALD technique, and the morphology, element distribution, structure, and surface chemical states of samples were systematically investigated by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), and X-ray photoemission spectroscopy (XPS), respectively. Finally, electrical properties of an MCP device as a function of nano-oxide thin film thickness were firstly studied, and the electrical measurement results showed that the average gain of MCP was greater than 2,000 at DC 800 V with nano-oxide thin film thickness approximately 122 nm. During electrical measurement, current jitter was observed, and possible reasons were preliminarily proposed to explain the observed experimental phenomenon.

  14. Optical layer development for thin films thermal conductivity measurement by pulsed photothermal radiometry

    Energy Technology Data Exchange (ETDEWEB)

    Martan, J., E-mail: jmartan@ntc.zcu.cz [New Technologies Research Centre, University of West Bohemia, Univerzitní 8, 306 14 Plzeň (Czech Republic)

    2015-01-15

    Measurement of thermal conductivity and volumetric specific heat of optically transparent thin films presents a challenge for optical-based measurement methods like pulsed photothermal radiometry. We present two approaches: (i) addition of an opaque optical layer to the surface and (ii) approximate correction of the mathematical model to incorporate semitransparency of the film. Different single layer and multilayer additive optical layers were tested. The materials of the optical layers were chosen according to analysis and measurement of their optical properties: emissivity and absorption coefficient. Presented are thermal properties’ measurement results for 6 different thin films with wide range of thermal conductivity in three configurations of surface: as deposited, added Ti layer, and added Ti/TiAlSiN layer. Measurements were done in dependence on temperature from room temperature to 500 °C. The obtained thermal effusivity evolution in time after the laser pulse shows different effects of the surface layers: apparent effusivity change and time delay. Suitability of different measurement configurations is discussed and results of high temperature testing of different optical layers are presented.

  15. Thin hydroxyapatite surface layers on titanium produced by ion implantation

    CERN Document Server

    Baumann, H; Bilger, G; Jones, D; Symietz, I

    2002-01-01

    In medicine metallic implants are widely used as hip replacement protheses or artificial teeth. The biocompatibility is in all cases the most important requirement. Hydroxyapatite (HAp) is frequently used as coating on metallic implants because of its high acceptance by the human body. In this paper a process is described by which a HAp surface layer is produced by ion implantation with a continuous transition to the bulk material. Calcium and phosphorus ions are successively implanted into titanium under different vacuum conditions by backfilling oxygen into the implantation chamber. Afterwards the implanted samples are thermally treated. The elemental composition inside the implanted region was determined by nuclear analysis methods as (alpha,alpha) backscattering and the resonant nuclear reaction sup 1 H( sup 1 sup 5 N,alpha gamma) sup 1 sup 2 C. The results of X-ray photoelectron spectroscopy indicate the formation of HAp. In addition a first biocompatibility test was performed to compare the growing of m...

  16. A mass transfer model of ethanol emission from thin layers of corn silage

    Science.gov (United States)

    A mass transfer model of ethanol emission from thin layers of corn silage was developed and validated. The model was developed based on data from wind tunnel experiments conducted at different temperatures and air velocities. Multiple regression analysis was used to derive an equation that related t...

  17. Residual stress fields in sol-gel-derived thin TiO2 layers

    NARCIS (Netherlands)

    Teeuw, D.H.J.; Haas, M. de; Hosson, J.Th.M. De

    1999-01-01

    This paper discusses the induction of residual stresses during the curing process of thin titania layers, which are derived using a sol-gel process. During this process, stresses may build up in the spinning stage, the drying stage, and the consolidation stage. The magnitude and character of these s

  18. Performance improvement in pentacene organic thin film transistors by inserting a C60 ultrathin layer

    Institute of Scientific and Technical Information of China (English)

    Sun Qin-Jun; Xu Zheng; Zhao Su-Ling; Zhang Fu-Jun; Gao Li-Yan

    2011-01-01

    The contact effect on the performances of organic thin film transistors is studied here. A C60 ultrathin layer is inserted between Al source-drain electrode and pentacene to reduce the contact resistance. By a 3 nm C60 modification,the injection harrier is lowered and the contact resistance is reduced. Thus, the field-effect mobility increases from 0.12to 0.52 cm2/(V.s). It means that inserting a C60 ultra thin layer is a good method to improve the organic thin film transistor (OTFT) performance. The output curve is simulated by using a charge drift model. Considering the contact of OTFTs should be carried out.

  19. Density measurement of thin layers by electron energy loss spectroscopy (EELS).

    Science.gov (United States)

    Thomas, Jürgen; Ramm, Jürgen; Gemming, Thomas

    2013-07-01

    A method to measure the density of thin layers is presented which utilizes electron energy loss spectroscopy (EELS) techniques within a transmission electron microscope. The method is based on the acquisition of energy filtered images in the low loss region as well as of an element distribution map using core loss edges. After correction of multiple inelastic scattering effects, the intensity of the element distribution map is proportional to density and thickness. The dependence of the intensities of images with low energy loss electrons on the density is different from that. This difference allows the calculation of the relative density pixel by pixel and to determine lateral density gradients or fluctuations in thin films without relying on a constant specimen thickness. The method is demonstrated at thin carbon layers produced with density gradients.

  20. Thin metal layer as transparent electrode in n-i-p amorphous silicon solar cells

    Directory of Open Access Journals (Sweden)

    Theuring Martin

    2014-07-01

    Full Text Available In this paper, transparent electrodes, based on a thin silver film and a capping layer, are investigated. Low deposition temperature, flexibility and low material costs are the advantages of this type of electrode. Their applicability in structured n-i-p amorphous silicon solar cells is demonstrated in simulation and experiment. The influence of the individual layer thicknesses on the solar cell performance is discussed and approaches for further improvements are given. For the silver film/capping layer electrode, a higher solar cell efficiency could be achieved compared to a reference ZnO:Al front contact.

  1. Optical properties of PZT thin films deposited on a ZnO buffer layer

    OpenAIRE

    Schneider, T.; Leduc, D; Cardin, J.; LUPI, C; Barreau, N; Gundel, H.

    2007-01-01

    International audience; The optical properties of lead zirconate titanate (PZT) thin films deposited on ZnO were studied by m-lines spectroscopy. In order to retrieve the refractive index and the thickness of both layers from the m-lines spectra, we develop a numerical algorithm for the case of a two-layer system and show its robustness in the presence of noise. The sensitivity of the algorithm of the two-layer model allows us to relate the observed changes in the PZT refractive index to the ...

  2. Optical properties of PZT thin films deposited on a ZnO buffer layer

    OpenAIRE

    Schneider, T.; Leduc, D; Cardin, J.; LUPI, C; Barreau, N; Gundel, H.

    2015-01-01

    The optical properties of lead zirconate titanate (PZT) thin films deposited on ZnO were studied by m-lines spectroscopy. In order to retrieve the refractive index and the thickness of both layers from the m-lines spectra, we develop a numerical algorithm for the case of a two-layer system and show its robustness in the presence of noise. The sensitivity of the algorithm of the two-layer model allows us to relate the observed changes in the PZT refractive index to the PZT structural change du...

  3. Stereospecific micellar electrokinetic chromatography assay of methionine sulfoxide reductase activity employing a multiple layer coated capillary.

    Science.gov (United States)

    Zhu, Qingfu; El-Mergawy, Rabab G; Heinemann, Stefan H; Schönherr, Roland; Jáč, Pavel; Scriba, Gerhard K E

    2013-09-01

    A micellar electrokinetic chromatography method for the analysis of the l-methionine sulfoxide diastereomers employing a successive multiple ionic-polymer layer coated fused-silica capillary was developed and validated in order to investigate the stereospecificity of methionine sulfoxide reductases. The capillary coating consisted of a first layer of hexadimethrine and a second layer of dextran sulfate providing a stable strong cathodic EOF and consequently highly repeatable analyte migration times. The methionine sulfoxide diastereomers, methionine as product as well as β-alanine as internal standard were derivatized by dabsyl chloride and separated using a 35 mM sodium phosphate buffer, pH 8.0, containing 25 mM SDS as BGE and a separation voltage of 25 kV. The method was validated in the range of 0.15-2.0 mM with respect to linearity and precision. The LODs of the analytes ranged between 0.04 and 0.10 mM. The assay was subsequently applied to determine the stereospecificity of methionine sulfoxide reductases as well as the enzyme kinetics of human methionine sulfoxide reductase A. Monitoring the decrease of the l-methionine-(S)-sulfoxide Km = 411.8 ± 33.8 μM and Vmax = 307.5 ± 10.8 μM/min were determined.

  4. Disturbance amplification in boundary layers over thin wall films

    Science.gov (United States)

    Saha, Sandeep; Page, Jacob; Zaki, Tamer A.

    2016-02-01

    In single-fluid boundary layers, streaks can amplify at sub-critical Reynolds numbers and initiate early transition to turbulence. Introducing a wall film of different viscosities can appreciably alter the stability of the base flow and, in particular, the transient growth of the perturbation streaks. The formalism of seminorms is used to identify optimal disturbances which maximize the kinetic energy in the two-fluid flow. An examination of optimal growth over a range of viscosity ratios of the film relative to the outer flow reveals three distinct regimes of amplification, each associated with a particular combination of the eigenfunctions. In order to elucidate the underlying amplification mechanisms, a model problem is formulated: An initial value problem is solved using an eigenfunction expansion and is used to compute the evolution of pairs of eigenfunctions. By appropriately selecting the pair, the initial value problem qualitatively reproduces the temporal evolution of the optimal disturbance, and provides an unambiguous explanation of the dynamics. Two regimes of transient growth are attributed to the evolution of the interface mode along with free-stream vortical modes; the third regime is due to the evolution of the interface and a discrete mode. The results demonstrate that a lower-viscosity film can effectively reduce the efficacy of the lift-up mechanism and, as a result, transient growth of disturbances. However, another mechanism of amplification of wall-normal vorticity arises due to the deformation of the two-fluid interface and becomes dominant below a critical viscosity ratio.

  5. Optical behavior of silver nanoparticles embedded in polymer thin film layers

    Science.gov (United States)

    Carlberg, M.; Pourcin, F.; Margeat, O.; Le Rouzo, J.; Berginc, G.; Sauvage, R.-M.; Ackermann, J.; Escoubas, L.

    2016-09-01

    The study of metal nanoparticles (NPs) is challenging for the control of the light matter interaction phenomena. In this context, our work is focused on optical characterization and modeling of polymer thin films layers with inclusions of previously chemically synthesized NPs. Through the presence of metallic NPs in polymer thin films, the optical properties are assumed to become tunable. Thin film layers with inclusions of differently shaped and sized silver NPs, such as nanospheres and nanoprisms, are optically characterized to get the scattering, the reflection and the absorption of the layers. One step and two step seed based methods of silver ions reduction are used for the chemical synthesis of nanospheres and nanoprisms. The plasmonic resonance peaks of these colloidal solutions range from 360 to 1300 nm. A poly vinyl pyrrolidone (PVP) polymer matrix is chosen for its light non-absorbing and NP-stabilizing properties. Knowledge on the shape and size of the NPs embedded in the spin coated layers is obtained by transmission electron microscopy (TEM) imaging. The optical properties include spectrophotometry and spectroscopic ellipsometry (SE) measurements to get the reflectance, the transmittance, the absorptance and the optical indices n and k of the heterogeneous layers. A redshift in absorption is measured between deposited nanospheres and other shaped NPs. FDTD simulations allow calculation of far and near field properties. The visualization of the NP interactions and the electric field enhancement, on and around the NPs, are studied to improve the understanding of the far field properties.

  6. Growth and optical characteristics of high-quality ZnO thin films on graphene layers

    Directory of Open Access Journals (Sweden)

    Suk In Park

    2015-01-01

    Full Text Available We report the growth of high-quality, smooth, and flat ZnO thin films on graphene layers and their photoluminescence (PL characteristics. For the growth of high-quality ZnO thin films on graphene layers, ZnO nanowalls were grown using metal-organic vapor-phase epitaxy on oxygen-plasma treated graphene layers as an intermediate layer. PL measurements were conducted at low temperatures to examine strong near-band-edge emission peaks. The full-width-at-half-maximum value of the dominant PL emission peak was as narrow as 4 meV at T = 11 K, comparable to that of the best-quality films reported previously. Furthermore, the stimulated emission of ZnO thin films on the graphene layers was observed at the low excitation energy of 180 kW/cm2 at room temperature. Their structural and optical characteristics were investigated using X-ray diffraction, transmission electron microscopy, and PL spectroscopy.

  7. On elastic waves in an thinly-layered laminated medium with stress couples under initial stress

    Directory of Open Access Journals (Sweden)

    P. Pal Roy

    1988-01-01

    Full Text Available The present work is concerned with a simple transformation rule in finding out the composite elastic coefficients of a thinly layered laminated medium whose bulk properties are strongly anisotropic with a microelastic bending rigidity. These elastic coefficients which were not known completely for a layered laminated structure, are obtained suitably in terms of initial stress components and Lame's constants λi, μi of initially isotropic solids. The explicit solutions of the dynamical equations for a prestressed thinly layered laminated medium under horizontal compression in a gravity field are derived. The results are discussed specifying the effects of hydrostatic, deviatoric and couple stresses upon the characteristic propagation velocities of shear and compression wave modes.

  8. Treatment of ice cover and other thin elastic layers with the parabolic equation method.

    Science.gov (United States)

    Collins, Michael D

    2015-03-01

    The parabolic equation method is extended to handle problems involving ice cover and other thin elastic layers. Parabolic equation solutions are based on rational approximations that are designed using accuracy constraints to ensure that the propagating modes are handled properly and stability constrains to ensure that the non-propagating modes are annihilated. The non-propagating modes are especially problematic for problems involving thin elastic layers. It is demonstrated that stable results may be obtained for such problems by using rotated rational approximations [Milinazzo, Zala, and Brooke, J. Acoust. Soc. Am. 101, 760-766 (1997)] and generalizations of these approximations. The approach is applied to problems involving ice cover with variable thickness and sediment layers that taper to zero thickness.

  9. Noninvasive analysis of thin turbid layers using microscale spatially offset Raman spectroscopy.

    Science.gov (United States)

    Conti, Claudia; Realini, Marco; Colombo, Chiara; Sowoidnich, Kay; Afseth, Nils Kristian; Bertasa, Moira; Botteon, Alessandra; Matousek, Pavel

    2015-06-01

    Here, we demonstrate, for the first time, the extension of applicability of recently developed microscale spatially offset Raman spectroscopy (SORS), micro-SORS, from the area of cultural heritage to a wider range of analytical problems involving thin, tens of micrometers thick diffusely scattering turbid layers. The method can be applied in situations where a high turbidity of layers prevents the deployment of conventional confocal Raman microscopy with its depth resolving capability. The method was applied successfully to detect noninvasively the presence of thin, highly turbid layers within polymers, wheat seeds, and paper. An invasive, cross sectional analysis confirmed the micro-SORS findings. Micro-SORS represents a new Raman imaging modality expanding the portfolio of noninvasive, chemically specific analytical tools.

  10. Characterization and modeling tools for light management in heterogeneous thin film layers

    Science.gov (United States)

    Le Rouzo, J.; Duché, D.; Ruiz, C. M.; Thierry, F.; Carlberg, M.; Berginc, G.; Pasquinelli, M.; Simon, J.-J.; Escoubas, L.; Flory, F.

    2016-09-01

    The extraordinary progresses in the design and realization of structures in inorganic or organic thin films, whether or not including nanoparticles, make it possible to develop devices with very specific properties. Mastering the links between the macroscopic optical properties and the opto-geometrical parameters of these heterogeneous layers is thus a crucial issue. We propose to present the tools used to characterize and to model thin film layers, from an optical point of view, highlighting the interest of coupling both experimental and simulation studies for improving our knowledge on the optical response of the structure. Different examples of studies are presented on CIGS, Perovskite, P3HT:ZnO, PC70BM, organic layer containing metallic nanoparticles and colored solar cells.

  11. The development of chloride ion selective polypyrrole thin film on a layer-by-layer carbon nanotube working electrode

    Science.gov (United States)

    Liu, Yang; Lynch, Jerome

    2011-04-01

    A chloride ion selective thin film sensor is proposed for measuring chloride ion concentration, which is an environmental parameter correlated to corrosion. In this work, electrochemical polymerization of Polypyrrole (PPy) doped with chloride ions was achieved on the top of a carbon nanotube (CNT) thin film as a working electrode in an electrochemical cell. The underlying CNT layer conjugated with doped PPy thin film can form a multifunctional "selfsensing" material platform for chloride ion detection in a concrete environment. The paper presents the first type of work using CNT and PPy as hybrid materials for chloride ion sensing. Electrochemical polymerization of PPy results in oxidation that yields an average of one positive charge distributed over four pyrrole units. This positive charge is compensated by negatively-charged chloride ions in the supporting electrolyte. In effect, the chloride ion-doped PPy has become molecularly imprinted with chloride ions thereby providing it with some degree of perm-selectivity for chloride ions. The detection limit of the fabricated chloride ion-doped PPy thin film can reach 10-8 M and selectivity coefficients are comparable to those in the literature. The reported work aims to lay a strong foundation for detecting chloride ion concentrations in the concrete environment.

  12. Layer-by-layer epitaxial thin films of the pyrochlore Tb2Ti2O7

    Science.gov (United States)

    Bovo, Laura; Rouleau, Christopher M.; Prabhakaran, Dharmalingam; Bramwell, Steven T.

    2017-02-01

    Layer-by-layer epitaxial growth of the pyrochlore magnet Tb2Ti2O7 on the isostructural substrate Y2Ti2O7 results in high-quality single crystal films of up to 60 nm thickness. Substrate-induced strain is shown to act as a strong and controlled perturbation to the exotic magnetism of Tb2Ti2O7, opening up the general prospect of strain-engineering the diverse magnetic and electrical properties of pyrochlore oxides.

  13. Preparation of Cu{sub 2}ZnSnS{sub 4} thin films by sulfurizing stacked precursor thin films via successive ionic layer adsorption and reaction method

    Energy Technology Data Exchange (ETDEWEB)

    Su Zhenghua; Yan Chang; Sun Kaiwen; Han Zili [School of Metallurgical Science and Engineering, Central South University, Changsha 410083 (China); Liu Fangyang, E-mail: liufangyang@csu.edu.cn [School of Metallurgical Science and Engineering, Central South University, Changsha 410083 (China); Liu Jin [School of Metallurgical Science and Engineering, Central South University, Changsha 410083 (China); Lai Yanqing, E-mail: laiyanqingcsu@163.com [School of Metallurgical Science and Engineering, Central South University, Changsha 410083 (China); Li Jie; Liu Yexiang [School of Metallurgical Science and Engineering, Central South University, Changsha 410083 (China)

    2012-07-15

    Earth-abundant Cu{sub 2}ZnSnS{sub 4} is a promising alternative photovoltaic material which has been examined as absorber layer of thin film solar cells. In this study, Cu{sub 2}ZnSnS{sub 4} (CZTS) thin films have been successfully fabricated by sulfurizing stacked precursor thin films via successive ionic layer adsorption and reaction (SILAR) method. The prepared CZTS thin films have been characterized by X-ray diffraction, energy dispersive spectrometer, Raman spectroscopy, UV-vis spectroscopy, Hall effect measurements and photoelectrochemical tests. Results reveal that the thin films have kesterite structured Cu{sub 2}ZnSnS{sub 4} and the p-type conductivity with a carrier concentration in the order of 10{sup 18} cm{sup -3} and an optical band gap of 1.5 eV, which are suitable for applications in thin film solar cells.

  14. Preparation of Cu2ZnSnS4 thin films by sulfurizing stacked precursor thin films via successive ionic layer adsorption and reaction method

    Science.gov (United States)

    Su, Zhenghua; Yan, Chang; Sun, Kaiwen; Han, Zili; Liu, Fangyang; Liu, Jin; Lai, Yanqing; Li, Jie; Liu, Yexiang

    2012-07-01

    Earth-abundant Cu2ZnSnS4 is a promising alternative photovoltaic material which has been examined as absorber layer of thin film solar cells. In this study, Cu2ZnSnS4 (CZTS) thin films have been successfully fabricated by sulfurizing stacked precursor thin films via successive ionic layer adsorption and reaction (SILAR) method. The prepared CZTS thin films have been characterized by X-ray diffraction, energy dispersive spectrometer, Raman spectroscopy, UV-vis spectroscopy, Hall effect measurements and photoelectrochemical tests. Results reveal that the thin films have kesterite structured Cu2ZnSnS4 and the p-type conductivity with a carrier concentration in the order of 1018 cm-3 and an optical band gap of 1.5 eV, which are suitable for applications in thin film solar cells.

  15. Zinc-oxide charge trapping memory cell with ultra-thin chromium-oxide trapping layer

    Directory of Open Access Journals (Sweden)

    Nazek El-Atab

    2013-11-01

    Full Text Available A functional zinc-oxide based SONOS memory cell with ultra-thin chromium oxide trapping layer was fabricated. A 5 nm CrO2 layer is deposited between Atomic Layer Deposition (ALD steps. A threshold voltage (Vt shift of 2.6V was achieved with a 10V programming voltage. Also for a 2V Vt shift, the memory with CrO2 layer has a low programming voltage of 7.2V. Moreover, the deep trapping levels in CrO2 layer allows for additional scaling of the tunnel oxide due to an increase in the retention time. In addition, the structure was simulated using Physics Based TCAD. The results of the simulation fit very well with the experimental results providing an understanding of the charge trapping and tunneling physics.

  16. Zinc-oxide charge trapping memory cell with ultra-thin chromium-oxide trapping layer

    Energy Technology Data Exchange (ETDEWEB)

    El-Atab, Nazek; Rizk, Ayman; Nayfeh, Ammar [Institute Center for Microsystems – iMicro, Department of Electrical Engineering and Computer Science (EECS), Masdar Institute of Science and Technology Abu Dhabi (United Arab Emirates); Okyay, Ali K. [Department of Electrical and Electronics Engineering, Bilkent University, 06800 Ankara (Turkey); UNAM-National Nanotechnology Research Center and Institute of Materials Science and Nanotechnology, Bilkent University, 06800 Ankara (Turkey)

    2013-11-15

    A functional zinc-oxide based SONOS memory cell with ultra-thin chromium oxide trapping layer was fabricated. A 5 nm CrO{sub 2} layer is deposited between Atomic Layer Deposition (ALD) steps. A threshold voltage (V{sub t}) shift of 2.6V was achieved with a 10V programming voltage. Also for a 2V V{sub t} shift, the memory with CrO{sub 2} layer has a low programming voltage of 7.2V. Moreover, the deep trapping levels in CrO{sub 2} layer allows for additional scaling of the tunnel oxide due to an increase in the retention time. In addition, the structure was simulated using Physics Based TCAD. The results of the simulation fit very well with the experimental results providing an understanding of the charge trapping and tunneling physics.

  17. Zinc-oxide charge trapping memory cell with ultra-thin chromium-oxide trapping layer

    Science.gov (United States)

    El-Atab, Nazek; Rizk, Ayman; Okyay, Ali K.; Nayfeh, Ammar

    2013-11-01

    A functional zinc-oxide based SONOS memory cell with ultra-thin chromium oxide trapping layer was fabricated. A 5 nm CrO2 layer is deposited between Atomic Layer Deposition (ALD) steps. A threshold voltage (Vt) shift of 2.6V was achieved with a 10V programming voltage. Also for a 2V Vt shift, the memory with CrO2 layer has a low programming voltage of 7.2V. Moreover, the deep trapping levels in CrO2 layer allows for additional scaling of the tunnel oxide due to an increase in the retention time. In addition, the structure was simulated using Physics Based TCAD. The results of the simulation fit very well with the experimental results providing an understanding of the charge trapping and tunneling physics.

  18. Estimation of optical constants of a bio-thin layer (onion epidermis), using SPR spectroscopy

    Science.gov (United States)

    Rehman, Saif-ur-; Mumtaz, Huma; Hayashi, Shinji; Shaukat, S. F.; Sekkat, Zouheir

    2014-12-01

    We estimate the optical constants of a biological thin layer (Allium cepa) by surface plasmon resonance (SPR) spectroscopy. For this study, the fresh inner thin epidermis of an onion bulb was used and stacked directly on gold (Au) and silver (Ag) film surfaces in order to identify the shift in SPR mode of each metal film at an operating wavelength of 632.8 nm. The thickness and dielectric constants of the biological thin layer were determined by matching the experimental SPR curves to theoretical ones. The thickness and roughness of bare Au and Ag thin films were also measured by atomic force microscopy (AFM); the results of which are in good agreement with those obtained through experiment. Due to the high surface roughness of the natural onion epidermis layer, AFM could not measure the exact thickness of an onion epidermis. It is estimated that the value of the real part of the dielectric constant of an onion epidermis is between the dielectric constants of water and air.

  19. Spectroscopic investigations on thin adhesive layers in multi-material laminates.

    Science.gov (United States)

    Voronko, Yuliya; Chernev, Boril S; Eder, Gabriele C

    2014-01-01

    Three different spectroscopic approaches, Raman linescans, Raman imaging, and attenuated total reflection Fourier transform infrared spectroscopy (ATR FT-IR) imaging were evaluated for the visualization of the thin adhesive layers (3-6 μm) present in polymeric photovoltaic backsheets. The cross-sections of the multilayer laminates in the original, weathered, and artificially aged samples were investigated spectroscopically in order to describe the impact of the environmental factors on the evenness and thickness of the adhesive layers. All three methods were found to be suitable tools to detect and visualize these thin layers within the original and aged polymeric laminates. However, as the adhesive layer is not very uniform in thickness and partly disintegrates upon weathering and/or artificial aging, Raman linescans yield only qualitative information and do not allow for an estimation of the layer thickness. Upon increasing the measuring area by moving from one-dimensional linescans to two-dimensional Raman images, a much better result could be achieved. Even though a longer measuring time has to be taken into account, the information on the uniformity and evenness of the adhesive layer obtainable using the imaging technique is much more comprehensive. Although Raman spectroscopy is known to have the superior lateral resolution as compared with ATR FT-IR spectroscopy, the adhesive layers of the samples used within this study (layer thickness 3-6 μm) could also be detected and visualized by applying the ATR FT-IR spectroscopic imaging method. However, the analysis of the images was quite a demanding task, as the thickness of the adhesive layer was in the region of the resolution limit of this method. The information obtained for the impact of artificial aging and weathering on the adhesive layer obtained using Raman imaging and ATR FT-IR imaging was in good accordance.

  20. Thin-shell wormholes with a double layer in quadratic F(R) gravity

    CERN Document Server

    Eiroa, Ernesto F

    2016-01-01

    We present a family of spherically symmetric Lorentzian wormholes in quadratic F(R) gravity, with a thin shell of matter corresponding to the throat. At each side of the shell the geometry has a different constant value of the curvature scalar R. The junction conditions determine the equation of state between the pressure and energy density at the throat, where a double layer is also located. We analyze the stability of the configurations under perturbations preserving the spherical symmetry. In particular, we study thin-shell wormholes with mass and charge. We find that there exist values of the parameters for which stable static solutions are possible.

  1. Long-living plasmoids generation by high-voltage discharge through thin conducting layers

    CERN Document Server

    Pirozerski, A L

    2006-01-01

    A new type of pulse high voltage electric discharge through a thin conducting layer on the surface of glass plate has been investigated. The afterglow plasma of this discharge forms quasi-spherical object with a lifetime about 0.2-0.3 s. Electric properties of the objects were studied by electric probe method. Measurements of plasma radiation spectra kinetics at visible and near ultraviolet spectral ranges have been carried out. Comparative analysis of the physical properties of the plasmoids appearing in this discharges and of ones generated via thin metal wires burning is given. Possible mechanism of the plasma metastability are discussed.

  2. Layer-by-layer assembly of thin organic films on PTFE activated by cold atmospheric plasma

    Directory of Open Access Journals (Sweden)

    Tóth András

    2014-12-01

    Full Text Available An air diffuse coplanar surface barrier discharge is used to activate the surface of polytetrafluoroethylene (PTFE samples, which are subsequently coated with polyvinylpyrrolidone (PVP and tannic acid (TAN single, bi- and multilayers, respectively, using the dip-coating method. The surfaces are characterized by X-ray Photoelectron Spectroscopy (XPS, Attenuated Total Reflection – Fourier Transform Infrared Spectroscopy (ATR-FTIR and Atomic Force Microscopy (AFM. The XPS measurements show that with plasma treatment the F/C atomic ratio in the PTFE surface decreases, due to the diminution of the concentration of CF2 moieties, and also oxygen incorporation through formation of new C–O, C=O and O=C–O bonds can be observed. In the case of coated samples, the new bonds indicated by XPS show the bonding between the organic layer and the surface, and thus the stability of layers, while the gradual decrease of the concentration of F atoms with the number of deposited layers proves the creation of PVP/TAN bi- and multi-layers. According to the ATR-FTIR spectra, in the case of PVP/TAN multilayer hydrogen bonding develops between the PVP and TAN, which assures the stability of the multilayer. The AFM lateral friction measurements show that the macromolecular layers homogeneously coat the plasma treated PTFE surface.

  3. Influence of Surface Transition Layers on Phase Transformation and Pyroelectric Properties of Ferroelectric Thin Film

    Institute of Scientific and Technical Information of China (English)

    SUN Pu-Nan; L(U) Tian-Quan; CHEN Hui; CAO Wen-Wu

    2008-01-01

    Taking into account surface transition layers (STLs), we study the phase transformation and pyroelectric properties of ferroelectric thin films by employing the transverse Ising model (TIM) in the framework of the mean field approximation. The distribution functions representing the intra-layer and inter-layer couplings between the two nearest neighbour pseudo-spins are introduced to characterize STLs. Compared with the results obtained by the traditional treatments for the thin films using only the single surface transition layer (SSL), it is shown that the STL model reflects a more realistic and comprehensive situation of films. The effects of various parameters on the phase transformation properties have shown that STL can make the Curie temperature of the film higher or lower than that of the corresponding bulk material, and the thickness of STL is a key factor influencing the film properties. For a film with definite thickness, there exists a critical STL thickness at which ferroelectricity will disappear when the intra-layer and inter-layer interactions are weak.

  4. n +-Microcrystalline-Silicon Tunnel Layer in Tandem Si-Based Thin Film Solar Cells

    Science.gov (United States)

    Lee, Ching-Ting; Lee, Hsin-Ying; Chen, Kuan-Hao

    2016-10-01

    In this study, the p-SiC/ i-Si/ n-Si cell and the p-SiC/ i-SiGe/ n-Si cell deposited using plasma-enhanced chemical vapor deposition were cascaded for forming the tandem Si-based thin film solar cells to absorb the wide solar spectrum. To further improve the performances of the tandem Si-based thin film solar cells, a 5-nm-thick n +-microcrystalline-Si ( n +-μc-Si) tunnel layer deposited using the laser-assisted plasma-enhanced chemical vapor deposition was inserted between the p-SiC/ i-Si/ n-Si cell and the p-SiC/ i-SiGe/ n-Si cell. Since both the plasma and the CO2 laser were simultaneously utilized to efficiently decompose the reactant and doping gases, the carrier concentration and the carrier mobility of the n +-μc-Si tunnel layer were significantly improved. The ohmic contact formed between the p-SiC layer and the n +-μc-Si tunnel layer with low resistance was beneficial to the generated current transportation and the carrier recombination rate. Therefore, the conversion efficiency of the tandem solar cells was promoted from 8.57% and 8.82% to 9.91% compared to that without tunnel layer and with 5-nm-thick n +-amorphous-Si tunnel layer.

  5. Formation of hydrated layers in PMMA thin films in aqueous solution

    Energy Technology Data Exchange (ETDEWEB)

    Akers, Peter W. [School of Chemical Sciences, University of Auckland, Auckland (New Zealand); Nelson, Andrew R.J. [The Bragg Institute, Australian Nuclear Science and Technology Organisation, Menai, NSW (Australia); Williams, David E. [School of Chemical Sciences, University of Auckland, Auckland (New Zealand); MacDiarmid Institute of Advanced Materials and Nanotechnology, Wellington (New Zealand); McGillivray, Duncan J., E-mail: d.mcgillivray@auckland.ac.nz [School of Chemical Sciences, University of Auckland, Auckland (New Zealand); MacDiarmid Institute of Advanced Materials and Nanotechnology, Wellington (New Zealand)

    2015-10-30

    Graphical abstract: - Highlights: • Homogeneous thin PMMA films prepared on Si/SiOx substrates and measured in air and water. • Reproducible formation of highly hydrated layer containing 50% water at the PMMA/SiOx interface. • When heated the films swell at 50 °C without loss of material. • Upon re-cooling to 25 °C the surface roughens and material is lost. - Abstract: Neutron reflectometry (NR) measurements have been made on thin (70–150 Å) poly(methylmethacrylate) (PMMA) films on Si/SiOx substrates in aqueous conditions, and compared with parameters measured using ellipsometry and X-Ray reflectometry (XRR) on dry films. All techniques show that the thin films prepared using spin-coating techniques were uniform and had low roughness at both the silicon and subphase interfaces, and similar surface energetics to thicker PMMA films. In aqueous solution, NR measurements at 25 °C showed that PMMA forms a partially hydrated layer at the SiOx interface 10 Å under the film, while the bulk film remains intact and contains around 4% water. Both the PMMA film layer and the sublayer showed minimal swelling over a period of 24 h. At 50 °C, PMMA films in aqueous solution roughen and swell, without loss of PMMA material at the surface. After cooling back to 25 °C, swelling and roughening increases further, with loss of material from the PMMA layer.

  6. Theoretical analysis and experimental study on the influence of electric double layer on thin film lubrication

    Institute of Scientific and Technical Information of China (English)

    WANG Xin-jie; BAI Shao-xian; HUANG Ping

    2006-01-01

    A new mathematical model for thin film lubrication is established by taking into account the effect of an electric double layer.In the present paper,experiments are carried out on a self-made tester.With a composite block and a rotating disk,influence of electric double layer on thin film lubrication is studied.Two different methods are used to reconstruct the field of electric double layer so as to change its effect.One is to change the ionic concentration of lubricants by adding additives,and the other is to apply an external electric field on friction pairs.According theoretical analysis,both the methods will apparently change the electro-viscosity of the lubricant film so as to change the lubrication performances.After theoretical calculation of electro-viscosity is amended according to the experimental results,the equations of electro-viscosity are presented.The results show that the equivalent viscosity of fluid induced by the effect of electric double layer apparently increases with the decrease of thickness of the film while the lubrication film is thin enough.The effect of electro-viscosity is weakened as the thickness of the film increases.Moreover,the effect of electro-viscosity increases with the increase of external electric field at first.When the voltage reaches a certain value,the electro-viscosity begins to decrease.

  7. Exhaustive thin-layer cyclic voltammetry for absolute multianalyte halide detection.

    Science.gov (United States)

    Cuartero, Maria; Crespo, Gastón A; Ghahraman Afshar, Majid; Bakker, Eric

    2014-11-18

    Water analysis is one of the greatest challenges in the field of environmental analysis. In particular, seawater analysis is often difficult because a large amount of NaCl may mask the determination of other ions, i.e., nutrients, halides, and carbonate species. We demonstrate here the use of thin-layer samples controlled by cyclic voltammetry to analyze water samples for chloride, bromide, and iodide. The fabrication of a microfluidic electrochemical cell based on a Ag/AgX wire (working electrode) inserted into a tubular Nafion membrane is described, which confines the sample solution layer to less than 15 μm. By increasing the applied potential, halide ions present in the thin-layer sample (X(-)) are electrodeposited on the working electrode as AgX, while their respective counterions are transported across the perm-selective membrane to an outer solution. Thin-layer cyclic voltammetry allows us to obtain separated peaks in mixed samples of these three halides, finding a linear relationship between the halide concentration and the corresponding peak area from about 10(-5) to 0.1 M for bromide and iodide and from 10(-4) to 0.6 M for chloride. This technique was successfully applied for the halide analysis in tap, mineral, and river water as well as seawater. The proposed methodology is absolute and potentially calibration-free, as evidenced by an observed 2.5% RSD cell to cell reproducibility and independence from the operating temperature.

  8. Correlation between active layer thickness and ambient gas stability in IGZO thin-film transistors

    Science.gov (United States)

    Gao, Xu; Lin, Meng-Fang; Mao, Bao-Hua; Shimizu, Maki; Mitoma, Nobuhiko; Kizu, Takio; Ou-Yang, Wei; Nabatame, Toshihide; Liu, Zhi; Tsukagoshi, Kazuhito; Wang, Sui-Dong

    2017-01-01

    Decreasing the active layer thickness has been recently reported as an alternative way to achieve fully depleted oxide thin-film transistors for the realization of low-voltage operations. However, the correlation between the active layer thickness and device resistivity to environmental changes is still unclear, which is important for the optimized design of oxide thin-film transistors. In this work, the ambient gas stability of IGZO thin-film transistors is found to be strongly correlated to the IGZO thickness. The TFT with the thinnest IGZO layer shows the highest intrinsic electron mobility in a vacuum, which is greatly reduced after exposure to O2/air. The device with a thick IGZO layer shows similar electron mobility in O2/air, whereas the mobility variation measured in the vacuum is absent. The thickness dependent ambient gas stability is attributed to a high-mobility region in the IGZO surface vicinity with less sputtering-induced damage, which will become electron depleted in O2/air due to the electron transfer to adsorbed gas molecules. The O2 adsorption and deduced IGZO surface band bending is demonstrated by the ambient-pressure x-ray photoemission spectroscopy results.

  9. Layer-by-layer assembly of thin films containing exfoliated pristine graphene nanosheets and polyethyleneimine.

    Science.gov (United States)

    Sham, Alison Y W; Notley, Shannon M

    2014-03-11

    A method for the modification of surface properties through the deposition of stabilized graphene nanosheets is described. Here, the thickness of the film is controlled through the use of the layer-by-layer technique, where the sequential adsorption of the cationic polyethyleneimine (PEI) is followed by the adsorption of anionic graphene sheets modified with layers of polyethylene oxide-polypropylene oxide-polyethylene oxide (PEO-PPO-PEO) surfactants. The graphene particles were prepared using the surfactant-assisted liquid-phase exfoliation technique, with the low residual negative charge arising from edge defects. The buildup of the multilayer assembly through electrostatic interactions was strongly influenced by the solution conditions, including pH, ionic strength, and ionic species. Thereby, not only could the thickness of the film be tailored through the choice of the number of bilayers deposited but the viscoelastic properties of the film could also be modified by changing solution conditions at which the different species were deposited. The quartz crystal microbalance was used to measure the mass of graphene and polyelectrolyte immobilized at the interface as well as to probe the energy dissipated in the adsorbed layer.

  10. Excitation of Love waves in a thin film layer by a line source.

    Science.gov (United States)

    Tuan, H.-S.; Ponamgi, S. R.

    1972-01-01

    The excitation of a Love surface wave guided by a thin film layer deposited on a semiinfinite substrate is studied in this paper. Both the thin film and the substrate are considered to be elastically isotropic. Amplitudes of the surface wave in the thin film region and the substrate are found in terms of the strength of a line source vibrating in a direction transverse to the propagating wave. In addition to the surface wave, the bulk shear wave excited by the source is also studied. Analytical expressions for the bulk wave amplitude as a function of the direction of propagation, the acoustic powers transported by the surface and bulk waves, and the efficiency of surface wave excitation are obtained. A numerical example is given to show how the bulk wave radiation pattern depends upon the source frequency, the film thickness and other important parameters of the problem. The efficiency of surface wave excitation is also calculated for various parameter values.

  11. Growth of bismuth telluride thin film on Pt by electrochemical atomic layer epitaxy

    Institute of Scientific and Technical Information of China (English)

    ZHU Wen; YANG Jun-you; GAO Xian-hui; HOU Jie; ZHANG Tong-jun; CUI Kun

    2005-01-01

    An automated thin-layer flow cell electrodeposition system was developed for growing Bi2 Te3 thin film by ECALE. The dependence of the Bi and Te deposition potentials on Pt electrode was studied. In the first attempt,this reductive Te underpotential deposition (UPD)/reductive Bi UPD cycle was performed to 100 layers. A better linearity of the stripping charge with the number of cycles has been shown and confirmed a layer-by-layer growth mode, which is consistent with an epitaxial growth. The 4: 3 stoichiometric ratio of Bi to Te suggests that the incomplete charge transfer in HTeO2+ reduction excludes the possibility of Bi2 Te3 formation. X-ray photoelectron spectroscopy (XPS) analysis also reveals that the incomplete charge transfer in HTeO2+ occurs in Te direct deposition. The effective way of depositing Bi2 Te3 on Pt consists in oxidative Te UPD and reductive Bi UPD. The thin film deposited by this procedure was characterized by X-ray diffraction(XRD), scanning electron microscopy(SEM) and X-ray photoelectron spectroscopy(XPS). A polycrystalline characteristic was confirmed by XRD. The 2 : 3 stoichiometric ratio was confirmed by XPS. The SEM image indicates that the deposit looks like a series of buttons about 0.3 - 0.4 μm in diameter, which is corresponding with calculated thickness of the epitaxial film. This suggests that the particle growth appears to be linear with the number of cycles, as it is consistent with a layer by layer growth mode.

  12. Successful implementation of the stepwise layer-by-layer growth of MOF thin films on confined surfaces: Mesoporous silica foam as a first case study

    KAUST Repository

    Shekhah, Osama

    2012-01-01

    Here we report the successful growth of highly crystalline homogeneous MOF thin films of HKUST-1 and ZIF-8 on mesoporous silica foam, by employing a layer-by-layer (LBL) method. The ability to control and direct the growth of MOF thin films on confined surfaces, using the stepwise LBL method, paves the way for new prospective applications of such hybrid systems. © 2012 The Royal Society of Chemistry.

  13. Ultra-thin resistive switching oxide layers self-assembled by field-induced oxygen migration (FIOM) technique.

    Science.gov (United States)

    Lee, Sangik; Hwang, Inrok; Oh, Sungtaek; Hong, Sahwan; Kim, Yeonsoo; Nam, Yoonseung; Lee, Keundong; Yoon, Chansoo; Kim, Wondong; Park, Bae Ho

    2014-11-03

    High-performance ultra-thin oxide layers are required for various next-generation electronic and optical devices. In particular, ultra-thin resistive switching (RS) oxide layers are expected to become fundamental building blocks of three-dimensional high-density non-volatile memory devices. Until now, special deposition techniques have been introduced for realization of high-quality ultra-thin oxide layers. Here, we report that ultra-thin oxide layers with reliable RS behavior can be self-assembled by field-induced oxygen migration (FIOM) at the interface of an oxide-conductor/oxide-insulator or oxide-conductor/metal. The formation via FIOM of an ultra-thin oxide layer with a thickness of approximately 2-5 nm and 2.5% excess oxygen content is demonstrated using cross-sectional transmission electron microscopy and secondary ion mass spectroscopy depth profile. The observed RS behavior, such as the polarity dependent forming process, can be attributed to the formation of an ultra-thin oxide layer. In general, as oxygen ions are mobile in many oxide-conductors, FIOM can be used for the formation of ultra-thin oxide layers with desired properties at the interfaces or surfaces of oxide-conductors in high-performance oxide-based devices.

  14. Thermally activated decomposition of (Ga,Mn)As thin layer at medium temperature post growth annealing

    Science.gov (United States)

    Melikhov, Y.; Konstantynov, P.; Domagala, J.; Sadowski, J.; Chernyshova, M.; Wojciechowski, T.; Syryanyy, Y.; Demchenko, I. N.

    2016-05-01

    The redistribution of Mn atoms in Ga1-xMnxAs layer during medium-temperature annealing, 250-450 oC, by Mn K-edge X-ray absorption fine structure (XAFS) recorded at ALBA facility, was studied. For this purpose Ga1-xMnxAs thin layer with x=0.01 was grown on AlAs buffer layer deposited on GaAs(100) substrate by molecular beam epitaxy (MBE) followed by annealing. The examined layer was detached from the substrate using a “lift-off” procedure in order to eliminate elastic scattering in XAFS spectra. Fourier transform analysis of experimentally obtained EXAFS spectra allowed to propose a model which describes a redistribution/diffusion of Mn atoms in the host matrix. Theoretical XANES spectra, simulated using multiple scattering formalism (FEFF code) with the support of density functional theory (WIEN2k code), qualitatively describe the features observed in the experimental fine structure.

  15. Influence of adhesive layer properties on laser-generated ultrasonic waves in thin bonded plates

    Institute of Scientific and Technical Information of China (English)

    Sun Hong-Xiang; Xu Bai-Qiang; Zhang Hua; Gao Qian; Zhang Shu-Yi

    2011-01-01

    This paper studies quantitatively the generation of Lamb waves in thin bonded plates subjected to laser illumination, after considering the viscoelasticity of the adhesive layer. The displacements of such plates have been calculated in the frequency domain by using the finite element method, and the time domain response has been reconstructed by applying an inverse fast Fourier transform. Numerical results are presented showing the normal surface displacement for several configurations: a single aluminum plate, a three-layer bonded plate, and a two-layer plate. The characteristics of the laser-generated Lamb waves for each particular case have been investigated. In addition, the sensitivity of the transient responses to variations of material properties (elastic modulus, viscoelastic modulus, and thickness) of the adhesive layer has been studied in detail.

  16. Analysis of the p+/p window layer of thin film solar cells by simulation

    Institute of Scientific and Technical Information of China (English)

    林爱国; 丁建宁; 袁宁一; 王书博; 程广贵; 卢超

    2012-01-01

    The application of a p+/p configuration in the window layer of hydrogenated amorphous silicon thin film solar cells is simulated and analyzed utilizing an AMPS-1D program.The differences between p+-p-i-n configuration solar cells and p-i-n configuration solar cells are pointed out.The effects of dopant concentration,thickness of p+-layer,contact barrier height and defect density on solar cells are analyzed.Our results indicate that solar cells with a p+-p-i-n configuration have a better performance.The open circuit voltage and short circuit current were improved by increasing the dopant concentration of the p+ layer and lowering the front contact barrier height.The defect density at the p/i interface which exceeds two orders of magnitude in the intrinsic layer will deteriorate the cell property.

  17. Mathematical modelling of the thin layer solar drying of banana, mango and cassava

    Energy Technology Data Exchange (ETDEWEB)

    Koua, Kamenan Blaise; Fassinou, Wanignon Ferdinand; Toure, Siaka [Laboratoire d' Energie Solaire, Universite de Cocody- Abidjan, 22 BP 582 Abidjan 22 (Ivory Coast); Gbaha, Prosper [Laboratoire d' Energie Nouvelle et Renouvelable, Institut National Polytechnique, Felix HOUPHOUET - BOIGNY de Yamoussoukro (Ivory Coast)

    2009-10-15

    The main objectives of this paper are firstly to investigate the behaviour of the thin layer drying of plantain banana, mango and cassava experimentally in a direct solar dryer and secondly to perform mathematical modelling by using thin layer drying models encountered in literature. The variation of the moisture content of the products studied and principal drying parameters are analysed. Seven statistical models, which are empirical or semi-empirical, are tested to validate the experimental data. A non-linear regression analysis using a statistical computer program is used to evaluate the constants of the models. The Henderson and Pabis drying model is found to be the most suitable for describing the solar drying curves of plantain banana, mango and cassava. The drying data of these products have been analysed to obtain the values of the effective diffusivity during the falling drying rate phase. (author)

  18. Influence of electric double layer on thin film lubrication and elastohydrodynamic lubrication

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    In the present paper, the influence of electric double layer (EDL) on thin film lubricationand elastohydrodynamic lubrication is studied. With modified Reynolds equation for electric doublelayer, the effect of zeta-potential on the film thickness and pressure is numerically calculated. Theresults show that the influence of electric double layer on the lubrication film thickness is significantonly for thin film. The minimum film thickness will increase greatly if the influence of EDL is con-sidered. As the initial film thickness increases, the effect will greatly decrease. The existence ofEDL will decrease the friction coefficient of the lubrication film. Furthermore, the above tendency isstill applicable even if the materials of the friction pair are different.

  19. Electrophoretic deposition of siderite thin layers: Influence of electrode potential and deposition time

    Energy Technology Data Exchange (ETDEWEB)

    Ithurbide, A., E-mail: aurelie.ithurbide@cea.f [CEA Saclay/DEN/DPC/SECR, Laboratoire de Mesures et Modelisation de la Migration des Radionucleides, 91191 Gif-sur-Yvette (France); Peulon, S., E-mail: sophie.peulon@univ-evry.f [CNRS-Universite d' Evry-CEA, Laboratoire Analyse et Modelisation pour la Biologie et l' Environnement, UMR 8587, Boulevard Francois Mitterrand, 91025 Evry (France); Miserque, F. [CEA Saclay/DEN/DPC/SCP, Laboratoire de Reactivite des Surfaces et des Interfaces, 91191 Gif-sur-Yvette (France); Beaucaire, C. [CEA Saclay/DEN/DPC/SECR, Laboratoire de Mesures et Modelisation de la Migration des Radionucleides, 91191 Gif-sur-Yvette (France); Chausse, A. [CNRS-Universite d' Evry-CEA, Laboratoire Analyse et Modelisation pour la Biologie et l' Environnement, UMR 8587, Boulevard Francois Mitterrand, 91025 Evry (France); Poinssot, Ch. [CNRS-Universite d' Evry-CEA, Laboratoire Analyse et Modelisation pour la Biologie et l' Environnement, UMR 8587, Boulevard Francois Mitterrand, 91025 Evry (France); CEA Marcoule Saclay/DEN, Departement RadioChimie et Procedes, BP 17171 30207 Bagnols-sur-Ceze (France)

    2010-03-01

    Siderite thin layers have been obtained by electrophoretic deposition on an inert substrate (gold). Scanning electron microscopy image exhibits a compact and homogeneous film composed of round grains which diameter is about 1-2 {mu}m. The influence of two parameters, namely the electrode potential and the deposition time, on its thickness and its microstructure was investigated. The thickness was shown to be slightly dependent of the electrode potential (1.2 {mu}m for - 0.70 V and 1.7 {mu}m for - 0.95 V after 17 h). The crystallite size, estimated by X-ray diffraction patterns, was about 5 nm, depending on both electrode potential and deposition time. Despite its high sensitivity to oxygen, X-ray photoelectron spectroscopy spectra prove that the siderite surface has been kept out from oxidation. These siderite thin layers could be used as modified electrodes for further interaction studies.

  20. STUDY ON THE DETERMINATION OF TRACE Fe(Ⅲ) BY THIN LAYER RESIN PHASE SPECTROPHOTOMETRY

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A method to determine Fe(Ⅲ) by thin layer resin phase spectrophotometry has been developed in this paper. The colored complex formed by Fe(Ⅲ) and 1,2-benzendiol is concentrated on the 717# resin, then Fe(Ⅲ) can be determined directly by making thin layer. The method is sensitive with a apparent molar absorption of 4.8×104L/mol·cm, which is 16 times higher than that of liquid phase spectrophotometry, most coexisting ions do not influence the determination. The detection limit for Fe(Ⅲ) is 1.47μg/L with the precision of 3.3% [n=6, 7μg/50mL Fe(Ⅲ)]. The calibration curve is linear in the range of 0~25μg/50mL. The preposed method was applied to the determination of Fe(Ⅲ) in water sample with satisfactory results.

  1. STUDY ON THE DETERMINATION OF TRACE Fe(Ⅲ) BY THIN LAYER RESIN PHASE SPECTROPHOTOMETRY

    Institute of Scientific and Technical Information of China (English)

    HOU Yanmin; YANG Yongsheng; XIE Jimin; HUANG Weihong

    2007-01-01

    A method to determine Fe(Ⅲ) by thin layer resin phase spectrophotometry has been developed in this paper. The colored complex formed by Fe(Ⅲ) and 1,2-benzendiol is concentrated on the 717# resin, then Fe(Ⅲ) can be determined directly by making thin layer. The method is sensitive with a apparent molar absorption of 4.8×104L/mol. cm, which is 16 times higher than that of liquid phase spectrophotometry, most coexisting ions do not influence the determination. The detection limit for Fe(Ⅲ) is 1.47μg/L with the precision of 3.3% [n=6, 7μg/50mL Fe(Ⅲ)]. The calibration curve is linear in the range of 0~25μg/50mL. The preposed method was applied to the determination of Fe(Ⅲ) in water sample with satisfactory results.

  2. Magnetic domain observation of FeCo thin films fabricated by alternate monoatomic layer deposition

    Energy Technology Data Exchange (ETDEWEB)

    Ohtsuki, T., E-mail: ohtsuki@spring8.or.jp; Kotsugi, M.; Ohkochi, T. [Japan Synchrotron Radiation Research Institute (JASRI), 1-1-1 Koto, Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Kojima, T.; Mizuguchi, M.; Takanashi, K. [Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577 (Japan)

    2014-01-28

    FeCo thin films are fabricated by alternate monoatomic layer deposition method on a Cu{sub 3}Au buffer layer, which in-plane lattice constant is very close to the predicted value to obtain a large magnetic anisotropy constant. The variation of the in-plane lattice constant during the deposition process is investigated by reflection high-energy electron diffraction. The magnetic domain images are also observed by a photoelectron emission microscope in order to microscopically understand the magnetic structure. As a result, element-specific magnetic domain images show that Fe and Co magnetic moments align parallel. A series of images obtained with various azimuth reveal that the FeCo thin films show fourfold in-plane magnetic anisotropy along 〈110〉 direction, and that the magnetic domain structure is composed only of 90∘ wall.

  3. Bismuth iron oxide thin films using atomic layer deposition of alternating bismuth oxide and iron oxide layers

    Energy Technology Data Exchange (ETDEWEB)

    Puttaswamy, Manjunath; Vehkamäki, Marko [University of Helsinki, Department of Chemistry, P.O. Box 55, FI-00014 Helsinki (Finland); Kukli, Kaupo, E-mail: kaupo.kukli@helsinki.fi [University of Helsinki, Department of Chemistry, P.O. Box 55, FI-00014 Helsinki (Finland); University of Tartu, Institute of Physics, W. Ostwald 1, EE-50411 Tartu (Estonia); Dimri, Mukesh Chandra [National Institute of Chemical Physics and Biophysics, Akadeemia tee 23, EE-12618 Tallinn (Estonia); Kemell, Marianna; Hatanpää, Timo; Heikkilä, Mikko J. [University of Helsinki, Department of Chemistry, P.O. Box 55, FI-00014 Helsinki (Finland); Mizohata, Kenichiro [University of Helsinki, Department of Physics, P.O. Box 64, FI-00014 Helsinki (Finland); Stern, Raivo [National Institute of Chemical Physics and Biophysics, Akadeemia tee 23, EE-12618 Tallinn (Estonia); Ritala, Mikko; Leskelä, Markku [University of Helsinki, Department of Chemistry, P.O. Box 55, FI-00014 Helsinki (Finland)

    2016-07-29

    Bismuth iron oxide films with varying contributions from Fe{sub 2}O{sub 3} or Bi{sub 2}O{sub 3} were prepared using atomic layer deposition. Bismuth (III) 2,3-dimethyl-2-butoxide, was used as the bismuth source, iron(III) tert-butoxide as the iron source and water vapor as the oxygen source. The films were deposited as stacks of alternate Bi{sub 2}O{sub 3} and Fe{sub 2}O{sub 3} layers. Films grown at 140 °C to the thickness of 200–220 nm were amorphous, but crystallized upon post-deposition annealing at 500 °C in nitrogen. Annealing of films with intermittent bismuth and iron oxide layers grown to different thicknesses influenced their surface morphology, crystal structure, composition, electrical and magnetic properties. Implications of multiferroic performance were recognized in the films with the remanent charge polarization varying from 1 to 5 μC/cm{sup 2} and magnetic coercivity varying from a few up to 8000 A/m. - Highlights: • Bismuth iron oxide thin films were grown by atomic layer deposition at 140 °C. • The major phase formed in the films upon annealing at 500 °C was BiFeO{sub 3}. • BiFeO{sub 3} films and films containing excess Bi favored electrical charge polarization. • Slight excess of iron oxide enhanced saturative magnetization behavior.

  4. Matter Effects of Thin Layers Detecting Oil by Oscillations of Solar Neutrinos

    CERN Document Server

    Ioannisian, A N; Ioannisian, Ara N.; Smirnov, Alexei Yu.

    2002-01-01

    We consider a possibility to use the solar neutrinos for studies of small scale structures of the Earth and for geological research. Effects of thin layers of matter with density contrast on oscillations of Beryllium neutrinos inside the Earth are studied. We find that change of the $^7Be$ neutrino flux can reach 0.25 % for layers with density of oil and size $(10 - 100)$ km. Problems of detection are discussed. Hypothetical method would consist of measuring the $^7Be -$ flux by e.g. large deep underwater detector-submarine which could change its location.

  5. Influence of a thin metal layer on a beam propagation in a biconical optical fibre taper

    Science.gov (United States)

    Stasiewicz, K. A.; Moś, J. E.

    2016-12-01

    The paper presents results of a simulation of the plasmon effect achieved between a thin precious metal layer and a biconical optical fibre taper, manufactured on a standard single mode fibre. Gold, silver and titanium were used as a metal which fulfilled a cladding function for a small diameter structure. For simulation Mode Solution software was used on which modal and frequency analyses of a wavelength were provided in the range of 800-1700 nm. A displacement of a plasmon pick in dependence of thickness of a deposited precious layer for the highest plasmon effects was observed.

  6. PECULIARITIES OF LAMB WAVE PROPAGATION THROUGH TWO-LAYERED THIN PLATE MATERIALS

    Directory of Open Access Journals (Sweden)

    A. R. Baev

    2008-01-01

    Full Text Available Peculiarities of the plate wave propagation through two-layered thin plate have been analyzed and formulas for velocity determination of the quickest plate mode have been proposed.  The ascertained interaction makes it possible   to determine coating layer thickness in accordance with the given and known elastic parameters of contacting materials. On the basis of the developed methodology experiments have been carried out that revealed qualitative and quantitative correspondence  between theoretical and experimental data. The paper shows a principle possibility for assessment  of  material separation surface by time propagation data of the investigated mode .

  7. Lamb waves in a thin isotropic layer between two anisotropic layers

    Institute of Scientific and Technical Information of China (English)

    ZHANG Haiyan; ZHOU Quan; L(U) Donghui

    2004-01-01

    Attenuative Lamb wave propagation in adhesively bonded anisotropic composite plates is introduced. The isotropic adhesive exhibits viscous behavior to stimulate the poor curing of the middle layer. Viscosity is assumed to vary linearly with frequency, implying that attenuation per wavelength is constant. Attenuation can be implemented in the analysis through modification of elastic properties of isotropic adhesive. The new properties become complex, but cause no further complications in the analysis. The characteristic equation is the same as that used for the elastic plate case, except that both real and imaginary parts of the wave number (i.e., the attenuation) must be computed. Based on the Lowe's solution in finding the complex roots of characteristic equation, the effect of longitudinal and shear attenuation coefficients of the middle adhesive layer on phase velocity dispersion curves and attenuation dispersion curves of Lamb waves propagating in bonded anisotropic composites is visualized numerically.

  8. Slow invasion of a nonwetting fluid from multiple inlet sources in a thin porous layer.

    Science.gov (United States)

    Ceballos, L; Prat, M; Duru, P

    2011-11-01

    We numerically study the process of quasistatic invasion of a nonwetting fluid in 2D and 3D porous layers from multiple inlet injection sources and show that a porous layer acts as a two-phase filter as a result of the repeated convergence of flow paths: The probability for a pore at the outlet to be a breakthrough point is significantly lower than the fraction of active injection points at the inlet owing to the merging within the porous layer of liquid paths originating from different inlet injection points. The study of the breakthrough point statistics indicates that the number of breakthrough points diminishes with the system thickness and that the behavior of thin layers, defined here as systems of typical thicknesses of less than 15 lattice spacing units (≈15 pore or grain mean sizes), is distinct from thicker layers. For thicker systems, it is found that the probability of an outlet pore to be a breakthrough pore scales as l(1-d) where l is the system thickness and d is the space dimensionality, whereas, a power law behavior is not obtained with a thin system. Other properties, such as the invading phase occupancy profiles are studied. We also described a kinetic algorithm that allowed us to compute the occurrence times of breakthrough points. The distribution of these times is markedly different in 2D and in 3D.

  9. Reduced Cu concentration in CuAl-LPE-grown thin Si layers

    Energy Technology Data Exchange (ETDEWEB)

    Wang, T.H.; Ciszek, T.F.; Asher, S.; Reedy, R. [National Renewable Energy Lab., Golden, CO (United States)

    1995-08-01

    Cu-Al has been found to be a good solvent system to grow macroscopically smooth Si layers with thicknesses in tens of microns on cast MG-Si substrates by liquid phase epitaxy (LPE) at temperatures near 900{degrees}C. This solvent system utilizes Al to ensure good wetting between the solution and substrate by removing silicon native oxides, and employs Cu to control Al doping into the layers. Isotropic growth is achieved because of a high concentration of solute silicon in the solution and the resulting microscopically rough interface. The incorporation of Cu in the Si layers, however, was a concern since Cu is a major solution component and is generally regarded as a bad impurity for silicon devices due to its fast diffusivity and deep energy levels in the band gap. A study by Davis shows that Cu will nonetheless not degrade solar cell performance until above a level of 10{sup 17} cm{sup -3}. This threshold is expected to be even higher for thin layer silicon solar cells owing to the less stringent requirement on minority carrier diffusion length. But to ensure long term stability of solar cells, lower Cu concentrations in the thin layers are still preferred.

  10. Deposition of metal chalcogenide thin films by successive ionic layer adsorption and reaction (SILAR) method

    Indian Academy of Sciences (India)

    H M Pathan; C D Lokhande

    2004-04-01

    During last three decades, successive ionic layer adsorption and reaction (SILAR) method, has emerged as one of the solution methods to deposit a variety of compound materials in thin film form. The SILAR method is inexpensive, simple and convenient for large area deposition. A variety of substrates such as insulators, semiconductors, metals and temperature sensitive substrates (like polyester) can be used since the deposition is carried out at or near to room temperature. As a low temperature process, it also avoids oxidation and corrosion of the substrate. The prime requisite for obtaining good quality thin film is the optimization of preparative provisos viz. concentration of the precursors, nature of complexing agent, pH of the precursor solutions and adsorption, reaction and rinsing time durations etc. In the present review article, we have described in detail, successive ionic layer adsorption and reaction (SILAR) method of metal chalcogenide thin films. An extensive survey of thin film materials prepared during past years is made to demonstrate the versatility of SILAR method. Their preparative parameters and structural, optical, electrical properties etc are described. Theoretical background necessary for the SILAR method is also discussed.

  11. Atomically thin layered NiFe double hydroxides assembled 3D microspheres with promoted electrochemical performances

    Science.gov (United States)

    Li, Xiaomin; Zai, Jiantao; Liu, Yuanyuan; He, Xiaobo; Xiang, Shijie; Ma, Zifeng; Qian, Xuefeng

    2016-09-01

    LDHs in atomic thickness (mono-/bi-layers) usually exhibit novel physicochemical properties, especially in surface-dependent energy storage and catalysis areas. However, the thickness of the commonly reported 2D LDHs is in nanoscale and the bottom-up synthesis of atomically thin LDHs is rarely reported. Herein, high-quality atomically thin layered NiFe-LDHs assembled 3D microspheres were synthesized via a rational designed reaction system, where the formation of atomically thin building blocks was controlled by the synergetic effects of released carbonate anions and butanol. Furthermore, the complexant and solvents played important effects on the process of coprecipitation and the assembling of LDHs. Due to the nature of atomically thin LDHs nanosheets and unique 3D hierarchical structures, the obtained microspheres exhibited excellent electrocatalytic oxygen evolution reaction (OER) activity in alkaline medium with an onset overpotential (0.435 V, which is lower than that of common LDHs) and good durability. The as-prepared 3D NiFe-LDHs microspheres were also firstly used as supercapacitor materials and displayed a high specific capacitance of 1061 F g-1 at the current density of 1 A g-1.

  12. Study of Surface Loss Process on a Simulated Fe-based Material by Thin Layer Activation

    Institute of Scientific and Technical Information of China (English)

    HUANGDong-hui; WANGPing-sheng; ZHANGShi-shen; TIANWei-zhi; NIBang-fa; ZHANGLan-zhi; ZHANGGui-ying; LIUCun-xiong

    2003-01-01

    Taking the advantages of high sensitivity, non-destruction, and the capability of on-line measurement at favorable conditions, thin layer activation (TLA) is recognized as a method of choice in the study on surface loss processes of various materials. In present work, corrosion process of simulated Fe-based material (A3) was studied by TLA. The functionchemical peeling and weighing is established.of the residual activity versus the thickness lost from chemical peeling and weighing is established.

  13. Investigation of ZnS thin layers by thermal evaporation method (PVD)

    OpenAIRE

    2011-01-01

    Thin layers of ZnS in two different temperature conditions of 25 or 2000C and also with different thicknesses from 100nm to 600nm were prepared by physical vapor deposition. Absorption and also transmission spectra of the films were obtained to determine absorption coefficient, extinction constant and optical band gap of the films. It was found that by decreasing the substrate temperature or decreasing the film's thickness, optical band gap of ZnS films were increased or decreased, respective...

  14. Electrochemical investigations on crevice corrosion of a martensitic stainless steel in a thin-layer cell

    OpenAIRE

    Marcelin, Sabrina; Pébère, Nadine; Régnier, Sophie

    2015-01-01

    International audience; This paper focuses on crevice corrosion resistance of a martensitic stainless steel. First, electrochemical measurements were performed in deaerated bulk electrolytes for different chloride concentrations and different values of the pH to determine the critical parameters leading to dissolution or breakdown of the passive film. Then, a thin-layer cell was designed to confine the electrolyte between two parallel stainless steel planes. Impedance measurements obtained fo...

  15. Transmission spectroscopy in a thin vapour layer and its derivative properties

    Institute of Scientific and Technical Information of China (English)

    赵延霆; 赵建明; 肖连团; 贾锁堂

    2003-01-01

    A novel method of high-resolution spectroscopy of gases is proposed. The method is based on observing the optical behaviour of thin vapour layer when the particles cross the light beam or collide with the cell walls. The atomic motion and electronic quenching on gas-solid interfaces are explored by numerical analysis. The periodicity of peak values of transmission spectra and its derivative spectra demonstrates a sub-Doppler structure corresponding to the resonant transitions.

  16. Infection of Cultured Thin Cell Layer Roots of Lycopersicon esculentum by Meloidogyne incognita

    OpenAIRE

    Radin, D. N.; Eisenback, J. D.

    1991-01-01

    A new aseptic culture system for studying interactions between tomato (Lycopersicon esculentum) and Meloidogyne incognita is described. Epidermal thin cell layer explants from peduncles of tomato produced up to 20 adventitious roots per culture in 4-9 days on Murashige &Scoog medium plus kinetin and indole acetic acid. Rooted cultures were transferred to Gamborg's B-5 medium and inoculated with infective second-stage juveniles. Gall formation was apparent 5 days after inoculation and egg prod...

  17. Growth of Cu thin films by the successive ionic layer adsorption and reaction (SILAR) method

    Energy Technology Data Exchange (ETDEWEB)

    Lindroos, S.; Ruuskanen, T.; Ritala, M.; Leskelae, M

    2004-07-22

    Copper thin films were grown on reduced indium tin oxide, molybdenum and polymer substrates using successive ionic layer adsorption and reaction (SILAR) method. Copper films were grown sequentially in a controlled way using simple copper salt and basic solution of formaldehyde as precursors. The copper films were polycrystalline with no preferred orientation as characterised by X-ray diffraction. On all substrates, the growth was clearly island growth in the beginning but after the whole surface was covered, the growth was more homogeneous.

  18. Phonon and electron temperature and non-Fourier heat transport in thin layers

    Science.gov (United States)

    Carlomagno, I.; Cimmelli, V. A.; Sellitto, A.

    2017-04-01

    We present a thermodynamic model of heat conductor which allows for different temperatures of phonons and electrons. This model is applied to calculate the steady-state radial temperature profile in a circular thin layer. The compatibility of the obtained temperature profiles with the second law of thermodynamics is investigated in view of the requirement of positive entropy production and of a nonlocal constitutive equation for the entropy flux.

  19. Low-temperature atomic layer deposition of TiO{sub 2} thin layers for the processing of memristive devices

    Energy Technology Data Exchange (ETDEWEB)

    Porro, Samuele, E-mail: samuele.porro@polito.it; Conti, Daniele; Guastella, Salvatore; Ricciardi, Carlo [Applied Science and Technology Department, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino (Italy); Jasmin, Alladin; Pirri, Candido F. [Applied Science and Technology Department, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino, Italy and Center for Space Human Robotics@PoliTo, Istituto Italiano di Tecnologia, C.so Trento 21, 10129 Torino (Italy); Bejtka, Katarzyna; Perrone, Denis; Chiolerio, Alessandro [Center for Space Human Robotics@PoliTo, Istituto Italiano di Tecnologia, C.so Trento 21, 10129 Torino (Italy)

    2016-01-15

    Atomic layer deposition (ALD) represents one of the most fundamental techniques capable of satisfying the strict technological requirements imposed by the rapidly evolving electronic components industry. The actual scaling trend is rapidly leading to the fabrication of nanoscaled devices able to overcome limits of the present microelectronic technology, of which the memristor is one of the principal candidates. Since their development in 2008, TiO{sub 2} thin film memristors have been identified as the future technology for resistive random access memories because of their numerous advantages in producing dense, low power-consuming, three-dimensional memory stacks. The typical features of ALD, such as self-limiting and conformal deposition without line-of-sight requirements, are strong assets for fabricating these nanosized devices. This work focuses on the realization of memristors based on low-temperature ALD TiO{sub 2} thin films. In this process, the oxide layer was directly grown on a polymeric photoresist, thus simplifying the fabrication procedure with a direct liftoff patterning instead of a complex dry etching process. The TiO{sub 2} thin films deposited in a temperature range of 120–230 °C were characterized via Raman spectroscopy and x-ray photoelectron spectroscopy, and electrical current–voltage measurements taken in voltage sweep mode were employed to confirm the existence of resistive switching behaviors typical of memristors. These measurements showed that these low-temperature devices exhibit an ON/OFF ratio comparable to that of a high-temperature memristor, thus exhibiting similar performances with respect to memory applications.

  20. An approach to characterize ultra-thin conducting films protected against native oxidation by an in-situ capping layer

    NARCIS (Netherlands)

    Van Bui, H.; Wiggers, F.B.; Jong, de M.P.; Kovalgin, A.Y.

    2014-01-01

    We propose and demonstrate the application of a test structure to characterize electrical properties of ultra-thin titanium nitride films passivated by a non-conducting amorphous silicon layer. The amorphous silicon layer is used to prevent the oxidation of the conducting layer. Platinum electrodes

  1. Mathematical modeling of thin-layer drying of fermented and non-fermented sugarcane bagasse

    Energy Technology Data Exchange (ETDEWEB)

    Mazutti, Marcio A.; Zabot, Giovani; Boni, Gabriela; Skovronski, Aline; de Oliveira, Debora; Di Luccio, Marco; Oliveira, J. Vladimir; Treichel, Helen [Department of Food Engineering, URI - Campus de Erechim, P.O. Box 743, CEP 99700-000, Erechim - RS (Brazil); Rodrigues, Maria Isabel; Maugeri, Francisco [Department of Food Engineering, Faculty of Food Engineering, University of Campinas - UNICAMP, P.O. Box 6121, CEP 13083-862, Campinas - SP (Brazil)

    2010-05-15

    This work reports hot-air convective drying of thin-layer fermented and non-fermented sugarcane bagasse. For this purpose, experiments were carried out in a laboratory-scale dryer assessing the effects of solid-state fermentation (SSF) on the drying kinetics of the processing material. The fermented sugarcane bagasse in SSF was obtained with the use of Kluyveromyces marxianus NRRL Y-7571. Drying experiments were carried out at 30, 35, 40 and 45 C, at volumetric air flow rates of 2 and 3 m{sup 3} h{sup -1}. The ability of ten different thin-layer mathematical models was evaluated towards representing the experimental drying profiles obtained. Results showed that the fermented sugarcane bagasse presents a distinct, faster drying, behavior from that verified for the non-fermented material at the same conditions of temperature and volumetric air flow rate. It is shown that the fermented sugarcane bagasse presented effective diffusion coefficient values of about 1.3 times higher than the non-fermented material. A satisfactory agreement between experimental data and model results of the thin-layer drying of fermented and non-fermented sugarcane bagasse was achieved at the evaluated experimental conditions. (author)

  2. Thin layered drawing media probed by THz time-domain spectroscopy

    CERN Document Server

    Tasseva, J; Bartolini, P; Striova, J; Fontana, R; Torre, R

    2016-01-01

    Dry and wet drawing materials were investigated by THz time-domain spectroscopy in transmission mode. Carbon-based and iron-gall inks have been studied, some prepared following ancient recipes and others using current synthetic materials; a commercial ink was studied as well. We measured the THz signals on thin film of liquid inks deposited on polyethylene pellicles, comparing the results with the thick pellets of dried inks blended with polyethylene powder. This study required the implementation of a new experimental method and data analysis procedure able to provide a reliable extraction of the material transmission parameters from a structured sample composed of thin layers, down to thickness of few tens of micrometers. THz measurements on thin ink layers enabled the determination of both the absorption and the refractive index in an absolute scale in the 0.1 - 3 THz range, as well as the layer thickness. THz spectroscopic features of a paper sheet dyed by one of the iron-gall inks were also investigated. ...

  3. Electrical characterization of graphene oxide and organic dielectric layers based on thin film transistor

    Energy Technology Data Exchange (ETDEWEB)

    Karteri, İbrahim, E-mail: ibrahimkarteri@gmail.com [Department of Materials Science And Engineering, Kahramanmaras Sutcu Imam University, Kahramanmaraş 4610 (Turkey); Karataş, Şükrü [Department of Physics, Kahramanmaras Sutcu Imam University, Kahramanmaraş 4610 (Turkey); Yakuphanoğlu, Fahrettin [Department of Physics, Fırat University, Elazıg 2310 (Turkey)

    2014-11-01

    Highlights: • We report the synthesis of graphene oxide nanosheets and electrical characterization of graphene oxide based thin film transistor. • Graphene oxide (GO) nanosheets were prepared by using modified Hummers method. • We used insulator layers which are polymethylmethacrylate (PMMA) and polyvinyl phenol (PVP) for graphene oxide based thin flim transistor. - Abstract: We have studied the electrical characteristics of graphene oxide based thin flim transistor with the polymer insulators such as polymethyl methacrylate (PMMA) and poly-4-vinylphenol (PVP). Graphene oxide (GO) nanosheets were prepared by using modified Hummers method. The structural properties of GO nanosheets were characterized with Ultraviolet Visible (UV–vis), FT-IR spectroscopy and X-rays diffraction (XRD). Graphene oxide based thin flim transistor (GO-TFT) was prepared by a spin-coating and thermal evaporation technique. The electrical characterization of GO-TFT was analyzed by output and transfer characteristics by using Keithley-4200 semiconductor characterization system (SCS). The graphene oxide based thin flim transistor devices show p-type semiconducting behavior. The mobility, threshold voltage, sub-threshold swing value and I{sub on}/I{sub off} of GO-TFT were found to be 0.105 cm{sup 2} V{sup −1} s{sup −1}, −8.7 V, 4.03 V/decade and 10, respectively.

  4. Low-Dimensional Nanomaterials as Active Layer Components in Thin-Film Photovoltaics

    Science.gov (United States)

    Shastry, Tejas Attreya

    Thin-film photovoltaics offer the promise of cost-effective and scalable solar energy conversion, particularly for applications of semi-transparent solar cells where the poor absorption of commercially-available silicon is inadequate. Applications ranging from roof coatings that capture solar energy to semi-transparent windows that harvest the immense amount of incident sunlight on buildings could be realized with efficient and stable thin-film solar cells. However, the lifetime and efficiency of thin-film solar cells continue to trail their inorganic silicon counterparts. Low-dimensional nanomaterials, such as carbon nanotubes and two-dimensional metal dichalcogenides, have recently been explored as materials in thin-film solar cells due to their exceptional optoelectronic properties, solution-processability, and chemical inertness. Thus far, issues with the processing of these materials has held back their implementation in efficient photovoltaics. This dissertation reports processing advances that enable demonstrations of low-dimensional nanomaterials in thin-film solar cells. These low-dimensional photovoltaics show enhanced photovoltaic efficiency and environmental stability in comparison to previous devices, with a focus on semiconducting single-walled carbon nanotubes as an active layer component. The introduction summarizes recent advances in the processing of carbon nanotubes and their implementation through the thin-film photovoltaic architecture, as well as the use of two-dimensional metal dichalcogenides in photovoltaic applications and potential future directions for all-nanomaterial solar cells. The following chapter reports a study of the interaction between carbon nanotubes and surfactants that enables them to be sorted by electronic type via density gradient ultracentrifugation. These insights are utilized to construct of a broad distribution of carbon nanotubes that absorb throughout the solar spectrum. This polychiral distribution is then shown

  5. Semiconductor thin film transfer by wafer bonding and advanced ion implantation layer splitting technologies

    Science.gov (United States)

    Lee, Tien-Hsi

    Wafer bonding is an attractive technology for modern semiconductor and microelectronic industry due to its variability in allowing combination of materials. Initially, the bonding of wafers of the same material, such as silicon-silicon wafer bonding has been major interest. In the meantime, research interest has shifted to the bonding of dissimilar materials such as silicon to quartz or to sapphire. Thermal stress coming from the different expansion coefficients usually is a barrier to the success of dissimilar material bonding. Thermal stress may cause debonding, sliding, cracking, thermal misfit dislocations, or film wrinkle to impair the quality of the transferred layer. This dissertation presents several effective approaches to solve the thermal stress problem. These approaches concern bonding processes (low vacuum bonding and storage), thinning (advanced ion implantation layer splitting), and annealing processes (accumulative effect of blister generation) and are combined to design the best heat-treatment cycle. For this propose the concept of hot bonding is used in order to effectively minimize the thermal mismatch of dissimilar material bonding during the bonding and thinning procedures. During the initial bonding and bond strengthening phase, the difference in the temperature between bonding and annealing processes should be decreased as much as possible to avoid excessive thermal stresses. This concept can be realized either by increasing the bonding temperature or by decreasing the annealing temperature. A thinning technique has to employed that can thin the device wafer before debonding occurs due to the thermal stress generated either from the cooling-down process in the first case or by the annealing process itself in the late case. The ion implantation layer splitting method, also known as the Smart-cutsp°ler process, developed by Bruel at LEIT in France is a practical thinning technique which satisfies the above requirement. In the study, an

  6. System and Method for Fabricating Super Conducting Circuitry on Both Sides of an Ultra-Thin Layer

    Science.gov (United States)

    Brown, Ari D. (Inventor); Mikula, Vilem (Inventor)

    2017-01-01

    A method of fabricating circuitry in a wafer includes depositing a superconducting metal on a silicon on insulator wafer having a handle wafer, coating the wafer with a sacrificial layer and bonding the wafer to a thermally oxide silicon wafer with a first epoxy. The method includes flipping the wafer, thinning the flipped wafer by removing a handle wafer, etching a buried oxide layer, depositing a superconducting layer, bonding the wafer to a thermally oxidized silicon wafer having a handle wafer using an epoxy, flipping the wafer again, thinning the flipped wafer, etching a buried oxide layer from the wafer and etching the sacrificial layer from the wafer. The result is a wafer having superconductive circuitry on both sides of an ultra-thin silicon layer.

  7. Copper(II) Schiff base complexes and their mixed thin layers with ZnO nanoparticles

    Indian Academy of Sciences (India)

    MAGDALENA BARWIOLEK; ROBERT SZCZĘSNY; EDWARD SZŁYK

    2016-07-01

    Cu(II) complexes with Schiff bases derived from ethylenediamine (en) and 2-pyridinecarboxaldehyde (pyca), 2,5-dimethoxybenzaldehyde (dmbaH) or 4-imidazolecarboxaldehyde (4Him) were obtained and studied by elemental analysis, UV-VIS and IR spectra. Zinc oxide was synthesized using a simple homogeneous precipitation method with zinc acetate as a starting material. Thin layers of the studied Cu(II) complexes were deposited on Si(111) or ZnO/Si(111) substrates by a spin coating method and characterized with a scanningelectron microscopy (SEM/EDS), atomic force microscopy (AFM) and fluorescence spectroscopy. For Cu(II) layers the most intensive fluorescence bands due to intra-ligand transitions were observed between 462 and 503 nm. The fluorescence intensity of thin layers was corelated to the rotation speed. In the case of the [Cu(II)(en(4Him)₂)Cl₂](2a)/ZnO/Si and [Cu(en(dmbaH)₂)Cl₂](3a)/ZnO/Si layers the quenching of the emission band from ZnO at 440 nm (λex = 330 nm) associated with various intrinsic or extrinsic lattice defects was noted.

  8. Understanding geometric instabilities in thin films via a multi-layer model.

    Science.gov (United States)

    Lejeune, Emma; Javili, Ali; Linder, Christian

    2016-01-21

    When a thin stiff film adhered to a compliant substrate is subject to compressive stresses, the film will experience a geometric instability and buckle out of plane. For high film/substrate stiffness ratios with relatively low levels of strain, the primary mode of instability will either be wrinkling or buckling delamination depending on the material and geometric properties of the system. Previous works approach these systems by treating the film and substrate as homogenous layers, either consistently perfectly attached, or perfectly unattached at interfacial flaws. However, this approach neglects systems where the film and substrate are uniformly weakly attached or where interfacial layers due to surface modifications in either the film or substrate are present. Here we demonstrate a method for accounting for these additional thin surface layers via an analytical solution verified by numerical results. The main outcome of this work is an improved understanding of how these layers influence global behavior. We demonstrate the utility of our model with applications ranging from buckling based metrology in ultrathin films, to an improved understanding of the formation of a novel surface in carbon nanotube bio-interface films. Moving forward, this model can be used to interpret experimental results, particularly for systems which deviate from traditional behavior, and aid in the evaluation and design of future film/substrate systems.

  9. Electric-Field Noise above a Thin Dielectric Layer on Metal Electrodes

    CERN Document Server

    Kumph, Muir; Rabl, Peter; Brownnutt, Michael; Blatt, Rainer

    2015-01-01

    The electric-field noise above a layered structure composed of a planar metal electrode covered by a thin dielectric is evaluated and it is found that the dielectric film considerably increases the noise level, in proportion to its thickness. Importantly, even a thin (mono) layer of a low-loss dielectric can enhance the noise level by several orders of magnitude compared to the noise above a bare metal. Close to this layered surface, the power spectral density of the electric field varies with the inverse fourth power of the distance to the surface, rather than with the inverse square, as it would above a bare metal surface. Furthermore, compared to a clean metal, where the noise spectrum does not vary with frequency (in the radio-wave and microwave bands), the dielectric layer can generate electric-field noise which scales in inverse proportion to the frequency. For various realistic scenarios, the noise levels predicted from this model are comparable to those observed in trapped-ion experiments. Thus, these...

  10. Atomic layer deposition of absorbing thin films on nanostructured electrodes for short-wavelength infrared photosensing

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Jixian; Sutherland, Brandon R.; Hoogland, Sjoerd; Fan, Fengjia; Sargent, Edward H., E-mail: ted.sargent@utoronto.ca [Department of Electrical and Computer Engineering, University of Toronto, 10 King' s College Road, Toronto, Ontario M5S 3G4 (Canada); Kinge, Sachin [Advanced Technology, Materials and Research, Research and Development, Hoge Wei 33- Toyota Technical Centre, B-1930 Zaventem (Belgium)

    2015-10-12

    Atomic layer deposition (ALD), prized for its high-quality thin-film formation in the absence of high temperature or high vacuum, has become an industry standard for the large-area deposition of a wide array of oxide materials. Recently, it has shown promise in the formation of nanocrystalline sulfide films. Here, we demonstrate the viability of ALD lead sulfide for photodetection. Leveraging the conformal capabilities of ALD, we enhance the absorption without compromising the extraction efficiency in the absorbing layer by utilizing a ZnO nanowire electrode. The nanowires are first coated with a thin shunt-preventing TiO{sub 2} layer, followed by an infrared-active ALD PbS layer for photosensing. The ALD PbS photodetector exhibits a peak responsivity of 10{sup −2} A W{sup −1} and a shot-derived specific detectivity of 3 × 10{sup 9} Jones at 1530 nm wavelength.

  11. Electrochemical Examination of the Structure of Thin Hydrogel Layers Anchored to Regular and Microelectrode Surfaces.

    Science.gov (United States)

    Kaniewska, Klaudia; Karbarz, Marcin; Ziach, Krzysztof; Siennicka, Alicja; Stojek, Zbigniew; Hyk, Wojciech

    2016-09-01

    For the examination of hydrogel structure, thin layers of thermoresponsive gels based on poly(N-isopropylacrylamide) (pNIPA) and copolymer poly(N-isopropylacrylamide-co-sodium acrylate) (p(NIPA-co-AS)) were successfully anchored to microelectrode and regular electrode surfaces using the electrochemically induced free radical polymerization. The obtained layers were stable and covered the entire surface of the electrodes. Electroactive probes 1,1'-ferrocenedimethanol (Fc(CH2OH)2) and synthesized derivatives of ferrocene modified with polyethylene glycol units (Fc-PEGn) of various length (n = 4, 9, 75, and 135) were employed for studying the volume phase transition of the thin hydrogel layers and for the determination of their structural parameters. The quantitative information on the structural parameters of the hydrogel layers was derived from the obstruction model for diffusion using the voltammetrically determined diffusion coefficients for the model redox probe Fc(CH2OH)2. An approach to the determination of the effective radii of the gel openings (channels) for pNIPA and p(NIPA-co-AS) microlayers was developed. The obtained results were matched with the experimental results and allowed derivation of quantitative conclusions. The voltammograms obtained with modified electrodes in solutions containing Fc-PEG4, Fc-PEG9, and Fc-PEG75 were well defined and of appropriate height. However, the voltammograms recorded for Fc-PEG135, the hydrodynamic radius of which exceeded the size of the gel channels, were at the baseline level.

  12. Sound transmission through finite lightweight multilayered structures with thin air layers.

    Science.gov (United States)

    Dijckmans, A; Vermeir, G; Lauriks, W

    2010-12-01

    The sound transmission loss (STL) of finite lightweight multilayered structures with thin air layers is studied in this paper. Two types of models are used to describe the vibro-acoustic behavior of these structures. Standard transfer matrix method assumes infinite layers and represents the plane wave propagation in the layers. A wave based model describes the direct sound transmission through a rectangular structure placed between two reverberant rooms. Full vibro-acoustic coupling between rooms, plates, and air cavities is taken into account. Comparison with double glazing measurements shows that this effect of vibro-acoustic coupling is important in lightweight double walls. For infinite structures, structural damping has no significant influence on STL below the coincidence frequency. In this frequency region, the non-resonant transmission or so-called mass-law behavior dominates sound transmission. Modal simulations suggest a large influence of structural damping on STL. This is confirmed by experiments with double fiberboard partitions and sandwich structures. The results show that for thin air layers, the damping induced by friction and viscous effects at the air gap surfaces can largely influence and improve the sound transmission characteristics.

  13. White organic light-emitting diodes with an ultra-thin premixed emitting layer

    CERN Document Server

    Jeon, T; Tondelier, Denis; Bonnassieux, Yvan; Forget, Sebastien; Chenais, Sebastien; Ishow, Elena

    2014-01-01

    We described an approach to achieve fine color control of fluorescent White Organic Light-Emitting Diodes (OLED), based on an Ultra-thin Premixed emitting Layer (UPL). The UPL consists of a mixture of two dyes (red-emitting 4-di(4'-tert-butylbiphenyl-4-yl)amino-4'-dicyanovinylbenzene or fvin and green-emitting 4-di(4'-tert-butylbiphenyl-4-yl)aminobenzaldehyde or fcho) premixed in a single evaporation cell: since these two molecules have comparable structures and similar melting temperatures, a blend can be evaporated, giving rise to thin films of identical and reproducible composition compared to those of the pre-mixture. The principle of fine color tuning is demonstrated by evaporating a 1-nm-thick layer of this blend within the hole-transport layer (4,4'-bis[N-(1-naphtyl)-N-phenylamino]biphenyl (\\alpha-NPB)) of a standard fluorescent OLED structure. Upon playing on the position of the UPL inside the hole-transport layer, as well as on the premix composition, two independent parameters are available to finel...

  14. Organic and inorganic–organic thin film structures by molecular layer deposition: A review

    Directory of Open Access Journals (Sweden)

    Pia Sundberg

    2014-07-01

    Full Text Available The possibility to deposit purely organic and hybrid inorganic–organic materials in a way parallel to the state-of-the-art gas-phase deposition method of inorganic thin films, i.e., atomic layer deposition (ALD, is currently experiencing a strongly growing interest. Like ALD in case of the inorganics, the emerging molecular layer deposition (MLD technique for organic constituents can be employed to fabricate high-quality thin films and coatings with thickness and composition control on the molecular scale, even on complex three-dimensional structures. Moreover, by combining the two techniques, ALD and MLD, fundamentally new types of inorganic–organic hybrid materials can be produced. In this review article, we first describe the basic concepts regarding the MLD and ALD/MLD processes, followed by a comprehensive review of the various precursors and precursor pairs so far employed in these processes. Finally, we discuss the first proof-of-concept experiments in which the newly developed MLD and ALD/MLD processes are exploited to fabricate novel multilayer and nanostructure architectures by combining different inorganic, organic and hybrid material layers into on-demand designed mixtures, superlattices and nanolaminates, and employing new innovative nanotemplates or post-deposition treatments to, e.g., selectively decompose parts of the structure. Such layer-engineered and/or nanostructured hybrid materials with exciting combinations of functional properties hold great promise for high-end technological applications.

  15. Validated binary high-performance thin-layer chromatographic fingerprints of polyphenolics for distinguishing different Salvia species.

    Science.gov (United States)

    Ciesla, Łukasz; Hajnos, Michał; Staszek, Dorota; Wojtal, Łukasz; Kowalska, Teresa; Waksmundzka-Hajnos, Monika

    2010-07-01

    Salvia (sage) is the largest plant genus in the family Lamiaceae, embracing ca. 900 species. There is a growing interest in investigating chemical contents of different Salvia species, as some of them have been reported to exhibit a wide spectrum of biological activity. In this paper, conjugated (i.e., binary) chromatographic fingerprints have been introduced for the twenty Salvia species that are grown and cultivated in Poland. Apart from videoscans traditionally used for a comparison of the high-performance thin-layer chromatography fingerprints, digital scanning profiles and images obtained with use of the image processing program have also been employed. It is the first time that binary chromatographic fingerprints are used for the investigation of chemical contents of the Salvia species. The proposed procedure is rapid when compared with the similar ones presented in the literature, and moreover, it is easy to handle. The proposed method offers a possibility to discern the investigated species. It can be applied not only for chemotaxonomic purposes but also for finding new plant species that can be used as medical herbs (as it has been proposed, with S. triloba having a similar profile to S. officinalis). Validation of the method reveals that it is specific, reproducible, precise, and robust.

  16. SIMULTANEOUS ESTIMATION AND VALIDATION OF VARDENAFIL AND DAPOXETINE HYDROCHLORIDE IN PHARMACEUTICAL FORMULATION BY THIN LAYER CHROMATOGRAPHIC DENSITOMETRIC METHOD

    Directory of Open Access Journals (Sweden)

    Bhavin Chapla

    2012-05-01

    Full Text Available The present manuscript describes new, simple, accurate, and precise high performance thin layer chromatography method for the simultaneous determination of Vardenafil and Dapoxetine in combined tablet dosage form. Chromatographic separation of the drugs was performed on aluminium plates pre coated with silica gel 60 F254 as the stationary phase and the solvent system consisted of Chloroform: Methanol: Acetonitrile: Formic acid (4: 0.8: 4: 1 v/v/v/v. Densitometric evaluation of the separated zones was performed at 232 nm. The two drugs were satisfactorily resolved with Rf values 0.47 and 0.79 for Vardenafil and Dapoxetine Hydrochloride, respectively. The linear regression data for the calibration plots showed good relationship with r2 = 0.9995 from 150-750 ng/spot for Vardenafil and r2 = 0.9980 from 450-2250 ng/spot for Dapoxetine Hydrochloride. The methods were validated for precision, accuracy, and recovery. The percentage recovery for Vardenafil was found to be 99.58 – 100.72 % and 99.97 – 100.21% for Dapoxetine Hydrochloride. The limits of detection and quantification were 21.86 and 66.25 ng/spot per spot for Vardenafil and 128.58. and 389.64 ng/spot per spot for Dapoxetine Hydrochloride, respectively.

  17. Zinc oxide-based thin film functional layers for chemiresistive sensors

    Energy Technology Data Exchange (ETDEWEB)

    Miller, James B.; Ashok, Tejasvi; Lee, Sojung; Broitman, Esteban

    2012-08-31

    Sol-gel wet-chemical techniques were used to prepare ZnO, Al-ZnO (Al:Zn = 1:10 mol/mol) and Cu-ZnO (Cu:Zn = 1:10 mol/mol) thin films for characterization as functional layers for chemiresistive oxygen sensors. Cu and Al minor components influence the ZnO films' topography and their thermally induced chemical and structural evolution. As prepared (room temperature) films have the structure of layered basic zinc acetate, a lamellar ZnO precursor. Upon annealing at temperatures through 973 K, the films display similar chemical evolution patterns-temperatures above 773 K are needed to completely desorb solvents and decompose precursors. Cu facilitates c-axis orientation of the film as its structure matures, while Al slows its crystallization. Chemiresistive sensors, fabricated by coating thin film functional layers onto interdigitated electrode (IDE) transducers, were evaluated for their responses to oxygen at operating temperatures through 873 K. A ZnO/IDE sensor displays high sensitivity for O{sub 2} at an intermediate temperature, 673 K, reflecting an optimal balance between surface O{sub 2} coverage and carrier availability. At 1:10 mol/mol Cu:Zn and Al:Zn, the developing ZnO structure cannot accommodate all minor component atoms. Surplus atoms accumulate in independent phases at grain boundaries, contributing to both high base resistances (in N{sub 2}) and low sensitivity to oxygen. - Highlights: Black-Right-Pointing-Pointer Cu modification of a ZnO thin film improves c-axis alignment. Black-Right-Pointing-Pointer Al modification of ZnO thin film delays crystallization. Black-Right-Pointing-Pointer At 1:10 mol/mol Zn, the ZnO structure cannot accommodate all Cu or Al atoms. Black-Right-Pointing-Pointer Excess modifier causes high film resistance and low sensitivity as O{sub 2} sensors.

  18. Assessment of doses caused by electrons in thin layers of tissue-equivalent materials, using MCNP.

    Science.gov (United States)

    Heide, Bernd

    2013-10-01

    Absorbed doses caused by electron irradiation were calculated with Monte Carlo N-Particle transport code (MCNP) for thin layers of tissue-equivalent materials. The layers were so thin that the calculation of energy deposition was on the border of the scope of MCNP. Therefore, in this article application of three different methods of calculation of energy deposition is discussed. This was done by means of two scenarios: in the first one, electrons were emitted from the centre of a sphere of water and also recorded in that sphere; and in the second, an irradiation with the PTB Secondary Standard BSS2 was modelled, where electrons were emitted from an (90)Sr/(90)Y area source and recorded inside a cuboid phantom made of tissue-equivalent material. The speed and accuracy of the different methods were of interest. While a significant difference in accuracy was visible for one method in the first scenario, the difference in accuracy of the three methods was insignificant for the second one. Considerable differences in speed were found for both scenarios. In order to demonstrate the need for calculating the dose in thin small zones, a third scenario was constructed and simulated as well. The third scenario was nearly equal to the second one, but a pike of lead was assumed to be inside the phantom in addition. A dose enhancement (caused by the pike of lead) of ∼113 % was recorded for a thin hollow cylinder at a depth of 0.007 cm, which the basal-skin layer is referred to in particular. Dose enhancements between 68 and 88 % were found for a slab with a radius of 0.09 cm for all depths. All dose enhancements were hardly noticeable for a slab with a cross-sectional area of 1 cm(2), which is usually applied to operational radiation protection.

  19. Fabrication of (110)-one-axis-oriented perovskite-type oxide thin films and their application to buffer layer

    Science.gov (United States)

    Sato, Tomoya; Ichinose, Daichi; Kimura, Junichi; Inoue, Takaaki; Mimura, Takanori; Funakubo, Hiroshi; Uchiyama, Kiyoshi

    2016-10-01

    BaCe0.9Y0.1O3-δ (BCYO) and SrZr0.8Y0.2O3-δ (SZYO) thin films of perovskite-type oxides were deposited on (111)Pt/TiO x /SiO2/(100)Si substrates. X-ray diffraction patterns showed that the (110)-oriented BCYO and SZYO thin films were grown on (111)Pt/Si substrates directly without using any buffer layers. Thin films of SrRuO3 (SRO), a conductive perovskite-type oxide, were also deposited on those films and highly (110)-oriented SRO thin films were obtained. We believe that this (110)-oriented SRO works as a buffer layer to deposit (110)-oriented perovskite-type ferroelectric oxide thin films as well as a bottom electrode and can modify the ferroelectric properties of the oxide thin films by controlling their crystallographic orientations.

  20. Layer-by-Layer Thin Films for Co-Delivery of TGF-β siRNA and Epidermal Growth Factor to Improve Excisional Wound Healing.

    Science.gov (United States)

    Mandapalli, Praveen Kumar; Labala, Suman; Jose, Anup; Bhatnagar, Shubhmita; Janupally, Renuka; Sriram, Dharmarajan; Venuganti, Venkata Vamsi Krishna

    2016-06-27

    The major challenge with treatment of dermal wounds is accelerating healing process, while preventing the scar formation. Herein, we have fabricated layer-by-layer (LbL) polyelectrolyte multilayer films containing epidermal growth factor (EGF) and TGF-β siRNA to improve excisional wound healing and decrease scar formation. The chitosan and sodium alginate LbL thin films showed 13.0 MPa tensile strength and 2.22 N/cm(2) skin adhesion strength. The LbL thin films were found to be cytocompatible, where A431 epidermal keratinocytes adhered to the film and showed 86.2 ± 0.8% cell growth compared with cells cultured in the absence of LbL thin film. In contrast, LbL thin film did not promote the Escherichia coli and Staphylococcus aureus bacterial colony formation. In a C57BL/6 mouse excisional wound model, application of LbL thin films containing TGF-β siRNA significantly (p thin films containing EGF showed improved wound contraction (thin films resulted in accelerated wound healing and decreased collagen deposition. Furthermore, the LbL thin films with TGF-β siRNA and EGF combination showed greater reepithelialization. Taken together, we have successfully demonstrated the co-delivery of TGF-β siRNA and EGF peptide using LbL thin films to promote wound healing and decrease scar formation.

  1. Epitaxial TiN(001) wetting layer for growth of thin single-crystal Cu(001)

    Energy Technology Data Exchange (ETDEWEB)

    Chawla, J. S.; Zhang, X. Y.; Gall, D. [Department of Materials Science and Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180 (United States)

    2011-08-15

    Single-crystal Cu(001) layers, 4-1400 nm thick, were deposited on MgO(001) with and without a 2.5-nm-thick TiN(001) buffer layer. X-ray diffraction and reflection indicate that the TiN(001) surface suppresses Cu-dewetting, yielding a 4 x lower defect density and a 9 x smaller surface roughness than if grown on MgO(001) at 25 deg. C. In situ and low temperature electron transport measurements indicate that ultra-thin (4 nm) Cu(001) remains continuous and exhibits partial specular scattering at the Cu-vacuum boundary with a Fuchs-Sondheimer specularity parameter p = 0.6 {+-} 0.2, suggesting that the use of epitaxial wetting layers is a promising approach to create low-resistivity single-crystal Cu nanoelectronic interconnects.

  2. Significant Improvement of Organic Thin-Film Transistor Mobility Utilizing an Organic Heterojunction Buffer Layer

    Institute of Scientific and Technical Information of China (English)

    PAN Feng; QIAN Xian-Rui; HUANG Li-Zhen; WANG Hai-Bo; YAN Dong-Hang

    2011-01-01

    High-mobility vanadyl phthalocyanine (VOPc)/5,5″′-bis(4-fluorophenyl)-2,2′:5′,2″:5″,2″′-quaterthiophene (F2-P4T) thin-film transistors are demonstrated by employing a copper hexadecafluorophthalocyanine (F16 CuPc)/copper phthalocyanine (CuPc) heterojunction unit,which are fabricated at different substrate temperatures,as a buffer layer. The highest mobility of 4.08cm2/Vs is achieved using a F16CuPc/CuPc organic heterojunction buffer layer fabricated at high substrate temperature.Compared with the random small grain-like morphology of the room-temperature buffer layer,the high-temperature organic heterojunction presents a large-sized fiber-like film morphology,resulting in an enhanced conductivity.Thus the contact resistance of the transistor is significantly reduced and an obvious improvement in device mobility is obtained.

  3. Mass Transport in a Thin Layer of Bi-Viscous Mud Under Surface Waves

    Institute of Scientific and Technical Information of China (English)

    NG Chiu-on; FU Sau-chung; BAI Yu-chuan(白玉川)

    2002-01-01

    The mass transport in a thin layer of non-Newtonian bed mud under surface waves is examined with a two-fluidStokes boundary layer model. The mud is assumed to be a bi-viscous fluid, which tends to resist motion for small-appliedstresses, but flows readily when the yield stress is exceeded. Asymptotic expansions suitable for shallow fluid layers areapplied, and the second-order solutions for the mass transport induced by surface progressive waves are obtained numeri-cally. It is found that the stronger the non-Newtonian behavior of the mud, the more pronounced intermittency of theflow. Consequently, the mass transport velocity is diminished in magnitude, and can even become negative (i. e., oppo-site to wave propagation) for a certain range of yield stress.

  4. Large-Area Growth of Uniform Single-Layer MoS2 Thin Films by Chemical Vapor Deposition.

    Science.gov (United States)

    Baek, Seung Hyun; Choi, Yura; Choi, Woong

    2015-12-01

    We report the largest-size thin films of uniform single-layer MoS2 on sapphire substrates grown by chemical vapor deposition based on the reaction of gaseous MoO3 and S evaporated from solid sources. The as-grown thin films of single-layer MoS2 were continuous and uniform in thickness for more than 4 cm without the existence of triangular-shaped MoS2 clusters. Compared to mechanically exfoliated crystals, the as-grown single-layer MoS2 thin films possessed consistent chemical valence states and crystal structure along with strong photoluminescence emission and optical absorbance at high energy. These results demonstrate that it is possible to scale up the growth of uniform single-layer MoS2 thin films, providing potentially important implications on realizing high-performance MoS2 devices.

  5. Double-layer indium doped zinc oxide for silicon thin-film solar cell prepared by ultrasonic spray pyrolysis

    Institute of Scientific and Technical Information of China (English)

    Jiao Bao-Chen; Zhang Xiao-Dan; Wei Chang-Chun; Sun Jian; Ni Jian; Zhao Ying

    2011-01-01

    Indium doped zinc oxide (ZnO:In) thin films were prepared by ultrasonic spray pyrolysis on corning eagle 2000 glass substrate. 1 and 2 at.% indium doped single-layer ZnO:In thin films with different amounts of acetic acid added in the initial solution were fabricated. The 1 at.% indium doped single-layers have triangle grains. The 2 at.% indium doped single-layer with 0.18 acetic acid adding has the resistivity of 6.82 × 10-3 Ω· cm and particle grains. The double-layers structure is designed to fabricate the ZnO:In thin film with low resistivity (2.58×10-3 Ω· cm) and good surface morphology. It is found that the surface morphology of the double-layer ZnO:In film strongly depends on the substrate-layer, and the second-layer plays a large part in the resistivity of the double-layer ZnO:In thin film. Both total and direct transmittances of the double-layer ZnO:In film are above 80% in the visible light region. Single junction a-Si:H solar cell based on the double-layer ZnO:In as front electrode is also investigated.

  6. Indium sulfide thin films as window layer in chemically deposited solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Lugo-Loredo, S. [Universidad Autónoma de Nuevo León, UANL, Fac. de Ciencias Químicas, Av. Universidad S/N Ciudad Universitaria San Nicolás de Los Garza Nuevo León, C.P. 66451 (Mexico); Peña-Méndez, Y., E-mail: yolapm@gmail.com [Universidad Autónoma de Nuevo León, UANL, Fac. de Ciencias Químicas, Av. Universidad S/N Ciudad Universitaria San Nicolás de Los Garza Nuevo León, C.P. 66451 (Mexico); Calixto-Rodriguez, M. [Universidad Tecnológica Emiliano Zapata del Estado de Morelos, Av. Universidad Tecnológica No. 1, C.P. 62760 Emiliano Zapata, Morelos (Mexico); Messina-Fernández, S. [Universidad Autónoma de Nayarit, Ciudad de la Cultura “Amado Nervo” S/N, C.P. 63190 Tepic, Nayarit (Mexico); Alvarez-Gallegos, A. [Universidad Autónoma del Estado de Morelos, Centro de Investigación en Ingeniería y Ciencias Aplicadas, Av. Universidad 1001, C.P. 62209, Cuernavaca Morelos (Mexico); Vázquez-Dimas, A.; Hernández-García, T. [Universidad Autónoma de Nuevo León, UANL, Fac. de Ciencias Químicas, Av. Universidad S/N Ciudad Universitaria San Nicolás de Los Garza Nuevo León, C.P. 66451 (Mexico)

    2014-01-01

    Indium sulfide (In{sub 2}S{sub 3}) thin films have been synthesized by chemical bath deposition technique onto glass substrates using In(NO{sub 3}){sub 3} as indium precursor and thioacetamide as sulfur source. X-ray diffraction studies have shown that the crystalline state of the as-prepared and the annealed films is β-In{sub 2}S{sub 3}. Optical band gap values between 2.27 and 2.41 eV were obtained for these films. The In{sub 2}S{sub 3} thin films are photosensitive with an electrical conductivity value in the range of 10{sup −3}–10{sup −7} (Ω cm){sup −1}, depending on the film preparation conditions. We have demonstrated that the In{sub 2}S{sub 3} thin films obtained in this work are suitable candidates to be used as window layer in thin film solar cells. These films were integrated in SnO{sub 2}:F/In{sub 2}S{sub 3}/Sb{sub 2}S{sub 3}/PbS/C–Ag solar cell structures, which showed an open circuit voltage of 630 mV and a short circuit current density of 0.6 mA/cm{sup 2}. - Highlights: • In{sub 2}S{sub 3} thin films were deposited using the Chemical Bath Deposition technique. • A direct energy band gap between 2.41 to 2.27 eV was evaluated for the In{sub 2}S{sub 3} films. • We made chemically deposited solar cells using the In{sub 2}S{sub 3} thin films.

  7. Iridescent Art Nouveau glass - IBA and XPS for the characterisation of thin iridescent layers

    Science.gov (United States)

    Jembrih, D.; Neelmeijer, C.; Schreiner, M.; Mäder, M.; Ebel, M.; Svagera, R.; Peev, M.

    2001-07-01

    The external proton beam of the Tandem accelerator of the Research Centre in Rossendorf/Germany was used to carry out non-destructive particle-induced X-ray emission (PIXE) particle-induced gamma-ray emission (PIGE) and Rutherford backscattering (RBS) measurements simultaneously on Art Nouveau artifacts produced around 1900 by Tiffany/USA and Loetz/Austria. These studies should proof the technology of producing an iridescent layer on a glass surface. By means of the yield ratio Y(Si-K)/ Y(Si-γ) of both characteristic X-radiation (Si-K) and γ-radiation (Si-γ) of the element silicon it could be shown that a thin top layer is present on the glass surface due to the treatment of the heated artifacts (about 500°C) with an alcoholic solution of SnCl 2[1]. Combined evaluation of the PIXE and RBS spectra resulted in a thickness of 20-300 nm for this top layer. In addition, a transition region between the iridescent layer and the bulk glass was obtained by RUMP simulations. Approximately 80% of the total amount of the Sn were found to be present in this transition layer and only 10-20% in the outermost surface region. XPS studies showed that the outermost layer consists of SnO 2. The formation of other Sn compounds in the outermost near-surface region based on Sn-Si-O during the manufacturing process can be excluded.

  8. Iridescent Art Nouveau glass - IBA and XPS for the characterisation of thin iridescent layers

    Energy Technology Data Exchange (ETDEWEB)

    Jembrih, D. E-mail: dubravka.jembrih@fch.akbild.ac.at; Neelmeijer, C.; Schreiner, M.; Maeder, M.; Ebel, M.; Svagera, R.; Peev, M

    2001-07-01

    The external proton beam of the Tandem accelerator of the Research Centre in Rossendorf/Germany was used to carry out non-destructive particle-induced X-ray emission (PIXE) particle-induced gamma-ray emission (PIGE) and Rutherford backscattering (RBS) measurements simultaneously on Art Nouveau artifacts produced around 1900 by Tiffany/USA and Loetz/Austria. These studies should proof the technology of producing an iridescent layer on a glass surface. By means of the yield ratio Y(Si-K)/Y(Si-{gamma}) of both characteristic X-radiation (Si-K) and {gamma}-radiation (Si-{gamma}) of the element silicon it could be shown that a thin top layer is present on the glass surface due to the treatment of the heated artifacts (about 500 deg. C) with an alcoholic solution of SnCl{sub 2} . Combined evaluation of the PIXE and RBS spectra resulted in a thickness of 20-300 nm for this top layer. In addition, a transition region between the iridescent layer and the bulk glass was obtained by RUMP simulations. Approximately 80% of the total amount of the Sn were found to be present in this transition layer and only 10-20% in the outermost surface region. XPS studies showed that the outermost layer consists of SnO{sub 2}. The formation of other Sn compounds in the outermost near-surface region based on Sn-Si-O during the manufacturing process can be excluded.

  9. Temperature stability of ultra-thin mixed BaSr-oxide layers and their transformation.

    Science.gov (United States)

    Müller-Sajak, D; Islam, S; Pfnür, H; Hofmann, K R

    2012-08-01

    In the context of investigations of physical, chemical and electrical properties of ultra-thin layers of epitaxial and monocrystalline Sr(0.3)Ba(0.7)O on Si(100), we also investigated their thermal stability with x-ray photoelectron spectroscopy (XPS), electron energy loss spectroscopy (EELS), and low energy electron diffraction (LEED). At temperatures above 400 °C, transformation into silicate layers sets in. The stoichiometry after complete transformation was determined to be close to (Ba(0.8)Sr(0.2))(2)SiO(4) except for layers of only a few monolayers, where the silicate is not stoichiometric. There are strong indications that this silicate is stable until it desorbs at temperatures above 750 °C. Crystallinity, as seen with LEED, is lost during this transformation. Although transformation into silicate is coupled with metal desorption and compactification of the layers, they seem to remain closed. In addition, traces of Ba silicide at the Si interface were detected after layer desorption. This silicide cannot be desorbed thermally. The silicate layer has a bandgap of 5.9 ± 0.2 eV already for 3 ML thickness. Upon exposure to air, carbon and oxygen containing species, but no hydroxide, are formed irreversibly.

  10. Transient Response of Thin Wire above a Layered Half-Space Using TDIE/FDTD Hybrid Method

    Directory of Open Access Journals (Sweden)

    Bing Wei

    2012-01-01

    Full Text Available The TDIE/FDTD hybrid method is applied to calculate the transient responses of thin wire above a lossy layered half-space. The time-domain reflection of the layered half space is computed by one-dimensional modified FDTD method. Then, transient response of thin wire induced by two excitation sources (the incident wave and reflected wave is calculated by TDIE method. Finally numerical results are given to illustrate the feasibility and high efficiency of the presented scheme.

  11. Long-range surface plasmon polaritons at THz frequencies in thin semiconductor layers

    Institute of Scientific and Technical Information of China (English)

    Yichen Zhang; Audrey Berrier; Jaime Gómez Rivas

    2011-01-01

    Surface plasmon polaritons (SPPs) are electromagnetic waves coupled to the free charge carriers at the interface between a metal and a dielectric[1].These waves propagate along the interface,while decaying evanescently away from it.The propagation length of SPPs is mainly limited by Ohmic losses in the metal.A possible way to lower these losses is to reduce the penetration of the electromagnetic field inside the metal,which can be achieved by coupling the SPPs at the opposite sides of a thin metallic film.These coupled SPPs are known as long-range surface plasmon polaritons (LRSPPs) and have been thoroughly investigated at optical frequencies in thin layers of noble metals[2].%We present a theoretical investigation of THz long-range surface plasmon polaritons propagating on thin layers of InSb. The metallic behavior of doped semiconductors at THz frequencies allows the excitation of surface plasmon polaritons with propagation and confinement lengths that can be actively controlled. This control is achieved by acting on the free carrier density, which can be realized by changing the temperature of InSb.

  12. Bimodal Latex Effect on Spin-Coated Thin Conductive Polymer-Single-Walled Carbon Nanotube Layers.

    Science.gov (United States)

    Moradi, Mohammad-Amin; Larrakoetxea Angoitia, Katalin; van Berkel, Stefan; Gnanasekaran, Karthikeyan; Friedrich, Heiner; Heuts, Johan P A; van der Schoot, Paul; van Herk, Alex M

    2015-11-10

    We synthesize two differently sized poly(methyl methacrylate-co-tert-butyl acrylate) latexes by emulsion polymerization and mix these with a sonicated single-walled carbon nanotube (SWCNT) dispersion, in order to prepare 3% SWCNT composite mixtures. We spin-coat these mixtures at various spin-speed rates and spin times over a glass substrate, producing a thin, transparent, solid, conductive layer. Keeping the amount of SWCNTs constant, we vary the weight fraction of our smaller 30-nm latex particles relative to the larger 70-nm-sized ones. We find a maximum in the electrical conductivity up to 370 S/m as a function of the weight fraction of smaller particles, depending on the overall solid content, the spin speed, and the spin time. This maximum occurs at 3-5% of the smaller latex particles. We also find a more than 2-fold increase in conductivity parallel to the radius of spin-coating than perpendicular to it. Atomic force microscopy points at the existence of lanes of latex particles in the spin-coated thin layer, while large-area transmission electron microscopy demonstrates that the SWCNTs are aligned over a grid fixed on the glass substrate during the spin-coating process. We extract the conductivity distribution on the surface of the thin film and translate this into the direction of the SWCNTs in it.

  13. Layer-by-layer TiO(2)/WO(3) thin films as efficient photocatalytic self-cleaning surfaces.

    Science.gov (United States)

    Patrocinio, Antonio Otavio T; Paula, Leonardo F; Paniago, Roberto M; Freitag, Janna; Bahnemann, Detlef W

    2014-10-08

    New TiO2/WO3 films were produced by the layer-by-layer (LbL) technique and successfully applied as self-cleaning photocatalytic surfaces. The films were deposited on fluorine doped tin oxide (FTO) glass substrates from the respective metal oxide nanoparticles obtained by the sol-gel method. Thirty alternative immersions in pH = 2 TiO2 and pH = 10 WO3 sols resulted in ca. 400 nm thick films that exhibited a W(VI)/Ti(IV) molar ratio of 0.5, as determined by X-ray photoelectron spectroscopy. Scanning electron microscopy, along with atomic force images, showed that the resulting layers are constituted by aggregates of very small nanoparticles (films were investigated by UV-vis spectrophotometry and ultraviolet photoelectron spectroscopy. The films behave as nanoscale heterojunctions, and the presence of WO3 nanoparticles caused a decrease in the optical band gap of the bilayers compared to that of pure LbL TiO2 films. The TiO2/WO3 thin films exhibited high hydrophilicity, which is enhanced after exposition to UV light, and they can efficiently oxidize gaseous acetaldehyde under UV(A) irradiation. Photonic efficiencies of ξ = 1.5% were determined for films constituted by 30 TiO2/WO3 bilayers in the presence of 1 ppm of acetaldehyde, which are ∼2 times higher than those observed for pure LbL TiO2 films. Therefore, these films can act as efficient and cost-effective layers for self-cleaning, antifogging applications.

  14. Experimental evidence of tunable space-charge-layer-induced electrical properties of nanocrystalline ceria thin films.

    Science.gov (United States)

    Lee, Kyung-Ryul; Lee, Jong-Ho; Yoo, Han-Ill

    2013-10-07

    Fully dense nanocrystalline ceria films were successfully deposited on a MgO single crystal by pulsed laser deposition (PLD). The electrical conductivity of the nanocrystalline thin film was 20 times higher than that of the bulk sample. The activation energy of bulk ceria was 2.3 eV, whereas the activation energy of the nanocrystalline sample was only 1.2 eV. After post-annealing at 1273 K in which the grain size of the nanocrystalline thin film increased to ~400 nm, the electrical conductivity and activation energy of the film were changed similar to those of bulk. These unique electrical properties of the nano-crystalline thin-film can be attributed to the grain size effect, or more specifically, to the space charge layer (SCL) effect. Furthermore, the electrical conductivity of the nanocrystalline thin film became similar to that of the bulk in an extremely reducing atmosphere because of the unusual dependence of the SCL effect on the oxygen partial pressure.

  15. Thin-film monocrystalline-silicon solar cells based on a seed layer approach with 11% efficiency

    Science.gov (United States)

    Gordon, I.; Qiu, Y.; Van Gestel, D.; Poortmans, J.

    2010-09-01

    Solar modules made from thin-film crystalline-silicon layers of high quality on glass substrates could lower the price of photovoltaic electricity substantially. Almost half of the price of wafer-based silicon solar modules is currently due to the cost of the silicon wafers themselves. Using crystalline-silicon thin-film as the active material would substantially reduce the silicon consumption while still ensuring a high cell-efficiency potential and a stable cell performance. One way to create a crystalline-silicon thin film on glass is by using a seed layer approach in which a thin crystalline-silicon layer is first created on a non-silicon substrate, followed by epitaxial thickening of this layer. In this paper, we present new solar cell results obtained on 10-micron thick monocrystalline-silicon layers, made by epitaxial thickening of thin seed layers on transparent glass-ceramic substrates. We used thin (001)-oriented silicon single-crystal seed layers on glass-ceramic substrates provided by Corning Inc. that are made by a process based on anodic bonding and implant-induced separation. Epitaxial thickening of these seed layers was realized in an atmospheric-pressure chemical vapor deposition system. Simple solar cell structures in substrate configuration were made from the epitaxial mono-silicon layers. The Si surface was plasma-textured to reduce the front-side reflection. No other light trapping features were incorporated. Efficiencies of up to 11% were reached with Voc values above 600 mV indicating the good electronic quality of the material. We believe that by further optimizing the material quality and by integrating an efficient light trapping scheme, the efficiency potential of these single-crystal silicon thin films on glass-ceramics should be higher than 15%.

  16. Thin and thick layers of resin-based sealer cement bonded to root dentine compared: Adhesive behaviour.

    Science.gov (United States)

    Pane, Epita S; Palamara, Joseph E A; Messer, Harold H

    2015-12-01

    This study aims to evaluate tensile and shear bond strengths of one epoxy (AH) and two methacrylate resin-based sealers (EZ and RS) in thin and thick layers bonded to root dentine. An alignment device was prepared for accurate positioning of 20 root dentine cylinders in a predefined gap of 0.1 or 1 mm. Sealer was placed in the interface. Bond strength tests were conducted. Mode of failures and representative surfaces were evaluated. Data were analysed using anova and post-hoc tests, with P layer of sealer produced higher bond strength, except for the shear bond strength of EZ. Significant differences between thin and thick layers were found only in tensile bond strengths of AH and RS. Mixed type of failure was constantly found with all sealers. Bond strengths of thick layers of resin-based sealers to root dentine tended to be higher than with thin layers.

  17. Visible light dynamical diffraction in a 1-D photonic crystal-based interferometer with an extremely thin spacer layer

    Science.gov (United States)

    Prudnikov, I. R.

    2016-01-01

    Properties of light diffraction in a Fabry-Pérot-like interferometer composed of two 1-D photonic crystals and a nanometer-thick spacer layer are analytically investigated. It is shown that the resonant enhancement of light wave intensity in such a layer is possible because of light dynamical diffraction from the photonic crystals of the interferometer. Numerical simulations of (i) light reflectivity and transmittance curves of the interferometer having an ultra-thin spacer layer (its thickness changes from less than 1 nm to about 10 nm) and (ii) the resonant distribution of the light wave intensity in the vicinity of the layer are performed. Based on the numerical simulations, potentialities for the determination of the structural parameters (e.g., thicknesses and refraction indexes) of ultra-thin spacer films are discussed. A difference is found to appear in resonant intensity enhancements inside the ultra-thin spacer layers between s- and p-polarized light waves.

  18. Preparation of bismuth telluride thin film by electrochemical atomic layer epitaxy(ECALE)

    Institute of Scientific and Technical Information of China (English)

    ZHU Wen; YANG Junyou; GAO Xianhui; HOU Jie; BAO Siqian; FAN Xian

    2007-01-01

    Thin-layer electrochemical studies of the underpotential deposition(UPD)of Bi and Te on cold rolled silver substrate have been performed.The voltammetric analysis of underpotential shift demonstrates that the initial Te UPD on Bi-covered Ag and Bi UPD on Te-covered Ag fitted UPD dynamics mechanism.A thin film of bismuth telluride was formed by alternately depositing Te and Bi via an automated flow deposition system.X-ray diffraction indicated the deposits of Bi2Te3.Energy Dispersive X-ray Detector quantitative analysis gave a 2:3 stoichiornetric ratio of Bi to Te,which was consistent with X-ray Diffraction results.Electron probe microanalysis of the deposits showed a network structure that results from the surface defects of the cold rolled Ag substrate and the lattice mismatch between substrate and deposit.

  19. Characterization of chemical bath deposited buffer layers for thin film solar cell applications

    Energy Technology Data Exchange (ETDEWEB)

    Dwyer, D.; Efstathiadis, H.; Haldar, P. [College of Nanoscale Science and Engineering, University at Albany - State University of New York, 257 Fuller Rd., Albany, NY 12203 (United States); Sun, R. [Angstrom Sun Technologies Inc., 33 Nagog Park, Acton, MA 01720 (United States)

    2010-10-15

    Cadmium sulfide (CdS), indium sulfide (In{sub 2}S{sub 3}) and zinc sulfide (ZnS) thin films have been deposited by chemical bath deposition (CBD) for buffer layer applications in Cu-chalcopyrite-based thin film solar cells. Films were characterized by scanning electron microscopy (SEM), UV-Vis transmission, X-ray photoelectron spectroscopy (XPS), grazing-incidence X-ray diffraction (GIXRD), and spectroscopic ellipsometry. Results indicate CdS can be deposited with low oxygen content and high light transmission over 245-1700 nm. CBD-ZnS and CBD-InS both exhibit 5-10% less light transmission than CdS in the same thickness range. In terms of light transmission and degree of impurities CdS appears to be a better buffer material than CBD-ZnS or CBD-InS. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  20. Role of interfacial friction for flow instabilities in a thin polar-ordered active fluid layer

    Science.gov (United States)

    Sarkar, Niladri; Basu, Abhik

    2015-11-01

    We construct a generic coarse-grained dynamics of a thin inflexible planar layer of polar-ordered suspension of active particles that is frictionally coupled to an embedding isotropic passive fluid medium with a friction coefficient Γ . Being controlled by Γ , our model provides a unified framework to describe the long-wavelength behavior of a variety of thin polar-ordered systems, ranging from wet to dry active matter and free-standing active films. Investigations of the linear instabilities around a chosen orientationally ordered uniform reference state reveal generic moving and static instabilities in the system that can depend sensitively on Γ . Based on our results, we discuss estimation of bounds on Γ in experimentally accessible systems.

  1. Solution-processed In2S3 buffer layer for chalcopyrite thin film solar cells

    Directory of Open Access Journals (Sweden)

    Wang Lan

    2016-01-01

    Full Text Available We report a route to deposit In2S3 thin films from air-stable, low-cost molecular precursor inks for Cd-free buffer layers in chalcopyrite-based thin film solar cells. Different precursor compositions and processing conditions were studied to define a reproducible and robust process. By adjusting the ink properties, this method can be applied in different printing and coating techniques. Here we report on two techniques, namely spin-coating and inkjet printing. Active area efficiencies of 12.8% and 12.2% have been achieved for In2S3-buffered solar cells respectively, matching the performance of CdS-buffered cells prepared with the same batch of absorbers.

  2. Solution-processed In2S3 buffer layer for chalcopyrite thin film solar cells

    Science.gov (United States)

    Wang, Lan; Lin, Xianzhong; Ennaoui, Ahmed; Wolf, Christian; Lux-Steiner, Martha Ch.; Klenk, Reiner

    2016-02-01

    We report a route to deposit In2S3 thin films from air-stable, low-cost molecular precursor inks for Cd-free buffer layers in chalcopyrite-based thin film solar cells. Different precursor compositions and processing conditions were studied to define a reproducible and robust process. By adjusting the ink properties, this method can be applied in different printing and coating techniques. Here we report on two techniques, namely spin-coating and inkjet printing. Active area efficiencies of 12.8% and 12.2% have been achieved for In2S3-buffered solar cells respectively, matching the performance of CdS-buffered cells prepared with the same batch of absorbers.

  3. Experimental Evaluation of the RF Shielding Properties of a Thin Resistive Layer in a Ceramic Chamber

    CERN Document Server

    Brandt, D; Mostacci, A; Rinolfi, Louis; Ruggiero, F; Tsutsui, H; Vos, L

    2000-01-01

    In order to better understand the RF shielding properties of a thin resistive layer inside a ceramic vacuum chamber, an experimental set-up has been installed in the Electron Positron Accumulator (EPA) at CERN. A 500 MeV single bunch of about 7 x 1010 electrons (rms s=1 ns) is extracted into this dedicated beam line at a repetition rate of about 1 Hz. Wideband magnetic field probes are installed on the outer surfaces of a resistively coated ceramic test chamber as well as on a reference non-coated chamber located 2.5 m downstream the line. At the end of the extraction line, the beam passes through a thin Aluminum foil and is absorbed in an external dump. The experimental layout and the first results are presented. A comparison with theoretical expectations as well as possible implications for future machines are also discussed.

  4. ZnS Thin Films Deposited by a Spin Successive Ionic Layer Adsorption and Reaction Process

    Energy Technology Data Exchange (ETDEWEB)

    Han, Seungyeol; Lee, D. H.; Ryu, S. O.; Chang, Chih-hung

    2010-05-20

    In this article, we reported a spin successive ionic layer adsorption and reaction (SILAR) method for the first time. ZnS thin films were deposited by spin SILAR using ZnCl2 and Na2S aqueous precursor solutions at room temperature and atmosphere pressure. The optical, structural, and morphological characterizations of the films were studied by scanning electron microscopy, atomic force microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, and UV/visible spectroscopy. Smooth (average roughness <3 nm), uniform, and highly transparent ZnS (transmittance of over 90% in the visible band) thin films could be successfully deposited using this technique with shorter cycle time and much less solvent usage.

  5. Estimation of porosity in thin-layered reservoirs by seismic inversion

    Energy Technology Data Exchange (ETDEWEB)

    He, Nanqun; Reynolds, A.C. [Univ. of Tulsa, OK (United States)

    1995-12-31

    An effective method is presented to determine porosity distributions from seismic data for cases where the reservoir layers are thin. Porosity is determined by solving the inverse problem using a constrained generalized linear inversion (GLI) procedure. The inversion procedure estimates porosities directly rather than inverting for acoustic impedance or velocities and then estimating porosities. It is shown that sensitivity coefficients for porosity, i.e., the derivative of amplitudes with respect to porosity, can be computed analytically. Artificial interfaces are used to reduce non-uniquiness caused by lack of knowledge of thin bed reflection times. The artificial interfaces are generated by integration of seismic with log data. By using the artificial interfaces, the number of parameters to be estimated can be reduced and known formation information can be added as constraints. Inversion is done on only the seismic record associated with the reservoir instead of the whole seismic record.

  6. Reduced growth temperature of Bi6FeCoTi3O18 thin films by conductive bottom layers

    Science.gov (United States)

    Yun, Yu; Huang, Haoliang; Meng, Dechao; Cui, Zhangzhang; Wang, Jianlin; Fu, Zhengping; Peng, Ranran; Zhai, Xiaofang; Lu, Yalin

    2016-11-01

    The Aurivillius layered oxide homologous series attract wide interests due to their room temperature multiferroic properties. Unfortunately, the synthesis of such layered oxide epitaxial thin films has been a major challenge owing to the occurrence of growth defects and narrow growth temperature window. To obtain high quality epitaxial Bi6FeCoTi3O18 (BFCTO) thin films, the effects of insulating and conductive bottom layers were studied by laser molecular beam epitaxy. We found that the optimal deposition temperature for growth on conductive bottom layers is more than 90 °C lower than that on insulating bottom layers, which indicates the interface between BFCTO and conductive bottom layers has smaller interfacial energy than the interface between BFCTO and insulating bottom layers. The magnetic and ferroelectric properties of the optimized BFCTO thin films on insulating substrate and conductive bottom layers were studied. This study is important to control the growth of complex layered oxide thin films and exploit the applications for future room temperature multiferroic devices.

  7. Synthesis of multiferroic Er-Fe-O thin films by atomic layer and chemical vapor deposition

    Energy Technology Data Exchange (ETDEWEB)

    Mantovan, R., E-mail: roberto.mantovan@mdm.imm.cnr.it; Vangelista, S.; Wiemer, C.; Lamperti, A.; Tallarida, G. [Laboratorio MDM IMM-CNR, I-20864 Agrate Brianza (MB) (Italy); Chikoidze, E.; Dumont, Y. [GEMaC, Université de Versailles St. Quentin en Yvelines-CNRS, Versailles (France); Fanciulli, M. [Laboratorio MDM IMM-CNR, I-20864 Agrate Brianza (MB) (Italy); Dipartimento di Scienza dei Materiali, Università di Milano Bicocca, Milano (Italy)

    2014-05-07

    R-Fe-O (R = rare earth) compounds have recently attracted high interest as potential new multiferroic materials. Here, we report a method based on the solid-state reaction between Er{sub 2}O{sub 3} and Fe layers, respectively grown by atomic layer deposition and chemical vapor deposition, to synthesize Er-Fe-O thin films. The reaction is induced by thermal annealing and evolution of the formed phases is followed by in situ grazing incidence X-ray diffraction. Dominant ErFeO{sub 3} and ErFe{sub 2}O{sub 4} phases develop following subsequent thermal annealing processes at 850 °C in air and N{sub 2}. Structural, chemical, and morphological characterization of the layers are conducted through X-ray diffraction and reflectivity, time-of-flight secondary ion-mass spectrometry, and atomic force microscopy. Magnetic properties are evaluated by magnetic force microscopy, conversion electron Mössbauer spectroscopy, and vibrating sample magnetometer, being consistent with the presence of the phases identified by X-ray diffraction. Our results constitute a first step toward the use of cost-effective chemical methods for the synthesis of this class of multiferroic thin films.

  8. Synthesis of multiferroic Er-Fe-O thin films by atomic layer and chemical vapor deposition

    Science.gov (United States)

    Mantovan, R.; Vangelista, S.; Wiemer, C.; Lamperti, A.; Tallarida, G.; Chikoidze, E.; Dumont, Y.; Fanciulli, M.

    2014-05-01

    R-Fe-O (R = rare earth) compounds have recently attracted high interest as potential new multiferroic materials. Here, we report a method based on the solid-state reaction between Er2O3 and Fe layers, respectively grown by atomic layer deposition and chemical vapor deposition, to synthesize Er-Fe-O thin films. The reaction is induced by thermal annealing and evolution of the formed phases is followed by in situ grazing incidence X-ray diffraction. Dominant ErFeO3 and ErFe2O4 phases develop following subsequent thermal annealing processes at 850 °C in air and N2. Structural, chemical, and morphological characterization of the layers are conducted through X-ray diffraction and reflectivity, time-of-flight secondary ion-mass spectrometry, and atomic force microscopy. Magnetic properties are evaluated by magnetic force microscopy, conversion electron Mössbauer spectroscopy, and vibrating sample magnetometer, being consistent with the presence of the phases identified by X-ray diffraction. Our results constitute a first step toward the use of cost-effective chemical methods for the synthesis of this class of multiferroic thin films.

  9. Surface acoustic wave characterization of optical sol-gel thin layers.

    Science.gov (United States)

    Fall, Dame; Compoint, François; Duquennoy, Marc; Piombini, Hervé; Ouaftouh, Mohammadi; Jenot, Frédéric; Piwakowski, Bogdan; Belleville, Philippe; Ambard, Chrystel

    2016-05-01

    Controlling the thin film deposition and mechanical properties of materials is a major challenge in several fields of application. We are more particularly interested in the characterization of optical thin layers produced using sol-gel processes to reduce laser-induced damage. The mechanical properties of these coatings must be known to control and maintain optimal performance under various solicitations during their lifetime. It is therefore necessary to have means of characterization adapted to the scale and nature of the deposited materials. In this context, the dispersion of ultrasonic surface waves induced by a micrometric layer was studied on an amorphous substrate (fused silica) coated with a layer of ormosil using a sol-gel process. Our ormosil material is a silica-PDMS mixture with a variable polydimethylsiloxane (PDMS) content. The design and implementation of Surface Acoustic Wave InterDigital Transducers (SAW-IDT) have enabled quasi-monochromatic Rayleigh-type SAW to be generated and the dispersion phenomenon to be studied over a wide frequency range. Young's modulus and Poisson's ratio of coatings were estimated using an inverse method.

  10. Prediction of transmittance spectra for transparent composite electrodes with ultra-thin metal layers

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Zhao; Alford, T. L., E-mail: TA@asu.edu [School for Engineering of Matter, Transport, and Energy, Arizona State University, Tempe, Arizona 85287 (United States); Khorasani, Arash Elhami [ON Semiconductor Corp., Phoenix, Arizona 85005 (United States); Theodore, N. D. [CHD-Fab, Freescale Semiconductor Inc., Tempe, Arizona 85224 (United States); Dhar, A. [Intel Corp., 2501 NW 229th Ave, Hillsboro, Oregon 97124 (United States)

    2015-11-28

    Recent interest in indium-free transparent composite-electrodes (TCEs) has motivated theoretical and experimental efforts to better understand and enhance their electrical and optical properties. Various tools have been developed to calculate the optical transmittance of multilayer thin-film structures based on the transfer-matrix method. However, the factors that affect the accuracy of these calculations have not been investigated very much. In this study, two sets of TCEs, TiO{sub 2}/Au/TiO{sub 2} and TiO{sub 2}/Ag/TiO{sub 2}, were fabricated to study the factors that affect the accuracy of transmittance predictions. We found that the predicted transmittance can deviate significantly from measured transmittance for TCEs that have ultra-thin plasmonic metal layers. The ultrathin metal layer in the TCE is typically discontinuous. When light interacts with the metallic islands in this discontinuous layer, localized surface plasmons are generated. This causes extra light absorption, which then leads to the actual transmittance being lower than the predicted transmittance.

  11. Magnetoimpedance exchange coupling in different magnetic strength thin layers electrodeposited on Co-based magnetic ribbons

    Science.gov (United States)

    Jamilpanah, L.; Hajiali, M. R.; Morteza Mohseni, S.; Erfanifam, S.; Majid Mohseni, S.; Houshiar, M.; Ehsan Roozmeh, S.

    2017-04-01

    A systematic study of the effect of the deposition of cobalt (Co) and nickel (Ni) layers of various thicknesses on the magnetoimpedance (MI) response of a soft ferromagnetic amorphous ribbon (Co68.15Fe4.35Si12.5B15) is performed. The Co and Ni layers with thicknesses of 5, 10, 20 and 40 nm were grown on both sides of the amorphous ribbons by the electrodeposition technique. Microstrutures determined by x-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM) showed higher crystallinity of Ni-deposited layers and the amorphous ferromagnetic nature of Co-deposited. The vibrating sample magnetometry (VSM) does not represent significant changes between samples because of the small contribution of such a thin layer deposited on thick ribbons, but the MI response dictates that the magnetic coupling effect occurred at the interface of such bilayers, which is sensitive to the skin effect. The MI response of Co-deposited ribbons showed MI hysteretic behavior depending on the deposited layer thicknesses with an optimum response for the thickness of 20 nm whereas no hysteretic behavior was measured for Ni-deposited ribbons. This behavior is explained according to the exchange coupling between magnetization of electrodeposited layers and magnetic ribbons with respect to different magnetic properties of Co and Ni at different thicknesses. Also the MI response of Ni- and Co-deposited ribbons enhanced significantly at low thicknesses relative to bare ribbon. By increasing the thickness of deposited layers, MI response decreases considerably. Differences in MI ratios of Co- and Ni-deposited ribbons are explained according to exchange length, crystallinity and roughness of deposited layers. Our results could address a simple way to achieve a higher MI response, and explains physical aspects of exchange coupling in MI response all towards a better performance of magnetic field sensors.

  12. Thin layer imaging process for microlithography using radiation at strongly attenuated wavelengths

    Science.gov (United States)

    Wheeler, David R.

    2004-01-06

    A method for patterning of resist surfaces which is particularly advantageous for systems having low photon flux and highly energetic, strongly attenuated radiation. A thin imaging layer is created with uniform silicon distribution in a bilayer format. An image is formed by exposing selected regions of the silylated imaging layer to radiation. The radiation incident upon the silyliated resist material results in acid generation which either catalyzes cleavage of Si--O bonds to produce moieties that are volatile enough to be driven off in a post exposure bake step or produces a resist material where the exposed portions of the imaging layer are soluble in a basic solution, thereby desilylating the exposed areas of the imaging layer. The process is self limiting due to the limited quantity of silyl groups within each region of the pattern. Following the post exposure bake step, an etching step, generally an oxygen plasma etch, removes the resist material from the de-silylated areas of the imaging layer.

  13. High mobility indium zinc oxide thin film field-effect transistors by semiconductor layer engineering.

    Science.gov (United States)

    Walker, Daniel E; Major, Marton; Yazdi, Mehrdad Baghaie; Klyszcz, Andreas; Haeming, Marc; Bonrad, Klaus; Melzer, Christian; Donner, Wolfgang; von Seggern, Heinz

    2012-12-01

    Indium zinc oxide thin-film transistors are fabricated via a precursor in solution route on silicon substrates with silicon dioxide gate dielectric. It is found that the extracted mobility rises, peaks, and then decreases with increasing precursor concentration instead of rising and saturating. Investigation with scanning probe techniques reveals full thickness variations within the film which are assumed to adversely affect charge transport. Additional layers are coated, and the extracted mobility is observed to increase up to 19.7 cm(2) V(-1) s(-1). The reasons for this are examined in detail by direct imaging with scanning tunneling microscopy and extracting electron density profiles from X-ray reflection measurements. It is found that the optimal concentration for single layer films is suboptimal when coating multiple layers and in fact using many layers of very low concentrations of precursor in the solution, leading to a dense, defect and void free film, affording the highest mobilities. A consistent qualitative model of layer formation is developed explaining how the morphology of the film develops as the concentration of precursor in the initial solution is varied.

  14. Properties Evaluation of Thin Microhardened Surface Layer of Tool Steel after Wire EDM

    Directory of Open Access Journals (Sweden)

    Ľuboslav Straka

    2016-04-01

    Full Text Available This paper describes results of experimental research on the thin microhardened surface layer of a machined surface that occurs in materials using wire electrical discharge machining (WEDM with brass wire electrode. The direct influence of microhardened surface layer on resulting machined surface quality of tool steel EN X210Cr12 (W.-Nr. 1.2080 was examined. The aim of the experiment was to contribute to the knowledge of mutual interactions between main WEDM technological parameters, the influence of these parameters on the total affected depth, and on the variation of microhardness of sub-surface layers of machined surface. Based on the microhardness experimental measurements, mathematical models were established by the Least Square Method (LSM in order to simulate and predict final quality of machined surface after WEDM. Recommendations are given for setting the main technological parameters of the discharge process concerning minimization of total microhardened surface layer depth and microhardened surface layer homogeneity along the whole cross-section profile of the machined surface.

  15. Magnetic field dependence of the superconducting proximity effect in a two atomic layer thin metallic film

    Energy Technology Data Exchange (ETDEWEB)

    Caminale, Michael; Leon Vanegas, Augusto A.; Stepniak, Agnieszka; Oka, Hirofumi; Fischer, Jeison A.; Sander, Dirk; Kirschner, Juergen [Max-Planck-Institut fuer Mikrostrukturphysik, Halle (Germany)

    2015-07-01

    The intriguing possibility to induce superconductivity in a metal, in direct contact with a superconductor, is under renewed interest for applications and for fundamental aspects. The underlying phenomenon is commonly known as proximity effect. In this work we exploit the high spatial resolution of scanning tunneling spectroscopy at sub-K temperatures and in magnetic fields. We probe the differential conductance along a line from a superconducting 9 ML high Pb nanoisland into the surrounding two layer thin Pb/Ag wetting layer on a Si(111) substrate. A gap in the differential conductance indicates superconductivity of the Pb island. We observe an induced gap in the wetting layer, which decays with increasing distance from the Pb island. This proximity length is 21 nm at 0.38 K and 0 T. We find a non-trivial dependence of the proximity length on magnetic field. Surprisingly, we find that the magnetic field does not affect the induced superconductivity up to 0.3 T. However, larger fields of 0.6 T suppress superconductivity in the wetting layer, where the Pb island still remains superconducting. We discuss the unexpected robustness of induced superconductivity in view of the high electronic diffusivity in the metallic wetting layer.

  16. STUDY ON THE DETERMINATION OF TRACE BISMUTH(Ⅲ) BY THIN-LAYER RESIN PHASE SPECTROPHOTOMETRY

    Institute of Scientific and Technical Information of China (English)

    YAN Yongsheng; LU Xiaohua; FU Chengguang

    2003-01-01

    In this paper, a new thin-layer ion-exchange resin phase analytical method is introduced. It is based on that, the bismuthous cation can associate with iodic anions, so as to formed an anioncomplex [BiI-4] in a strong acidic environments. This anion complex can also exchanges with a weaker anions on the surface active site of anion exchange resin, so that a [R+] [BiI-4] solid phase binary associational system is produced. Owing to the solid system is a great many dispersive particulates, it can be pressed to a thin-layer by press tools of the so called "thin-layer resin phase"or "resin phase ", and using this solid association system spectrophotometry for the determination of trace metals. So it can increase the analytical sensitivity. This association system exhibits maximum absorbance at 460nm, and obeys Beer's law over the concentration range 0. 01ug/ml~1.20ug/ml of bismuthous(Ⅲ). It has a molar absorptivity of 7.1 ×105 [L/mol cm]. It indicated the resin phase spectrophotometry is a sensitive analytical method for trace bismuthous. It is 18 times higher than routine aqueous spectrophotometry. The relative standard deviations is 1.82% (n=6) for the measurements of 0. 5ug/ml Bi(Ⅲ). The detection limit of Bismuthous(Ⅲ) is 1.4 ×10-8mol/L. The method has applied to the analysis Bi(Ⅲ) in environmental water samples.

  17. Investigation of ZnS thin layers by thermal evaporation method (PVD

    Directory of Open Access Journals (Sweden)

    MR Khanlary

    2011-03-01

    Full Text Available Thin layers of ZnS in two different temperature conditions of 25 or 2000C and also with different thicknesses from 100nm to 600nm were prepared by physical vapor deposition. Absorption and also transmission spectra of the films were obtained to determine absorption coefficient, extinction constant and optical band gap of the films. It was found that by decreasing the substrate temperature or decreasing the film's thickness, optical band gap of ZnS films were increased or decreased, respectively. These phenomena can be attributed to the quantum size effect.

  18. Bearing Capacity of Footings on Thin Layer of Sand on Soft Cohesive Soil

    DEFF Research Database (Denmark)

    Philipsen, J.; Sørensen, Carsten S.

    2004-01-01

    This paper contains the results of some numerical calculations performed with the aim to determine the bearing capacities of footings placed on a thin layer of sand underlain by soft cohesive soil. During the last 30-35 years different analytical and empirical calculation methods for this situation...... have been presented. These methods often give widely different results. Therefore, in the light of the numerical calculations, the analytical and empirical calculation methods have been evaluated and compared. The calculations have been carried out based on results from well documented and well...

  19. Bound exciton photoluminescence from ion‑implanted phosphorus in thin silicon layers.

    Science.gov (United States)

    Sumikura, Hisashi; Nishiguchi, Katsuhiko; Ono, Yukinori; Fujiwara, Akira; Notomi, Masaya

    2011-12-01

    We report the observation of clear bound exciton (BE) emission from ion-implanted phosphorus. Shallow implantation and high-temperature annealing successfully introduce active donors into thin silicon layers. The BE emission at a wavelength of 1079 nm shows that a part of the implanted donors are definitely activated and isolated from each other. However, photoluminescence and electron spin resonance studies find a cluster state of the activated donors. The BE emission is suppressed by this cluster state rather than the nonradiative processes caused by ion implantation. Our results provide important information about ion implantation for doping quantum devices with phosphorus quantum bits.

  20. High performance thin layer chromatographic method for simultaneous estimation of ibuprofen and pseudoephedrine hydrochloride

    Directory of Open Access Journals (Sweden)

    Chitlange S

    2008-01-01

    Full Text Available High performance thin layer chromatographic method is developed for simultaneous estimation of ibuprofen and pseudoephedrine hydrochloride in tablets. Silica gel 60F 254 plates were used as stationary phase and t.butanol: ethyl acetate: glacial acetic acid: water (7:4:2:2 v/v as mobile phase. Wavelength selected for analysis was 254 nm. Percent estimation of ibuprofen and pseudoephedrine hydrochloride was found to be 99.56% and 98.77%, respectively. Percent recovery for both the drugs was found in the range of 98.27% to 100.91%, respectively.