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Sample records for chemical solution stains

  1. 21 CFR 864.1850 - Dye and chemical solution stains.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Dye and chemical solution stains. 864.1850 Section 864.1850 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Biological Stains § 864.1850 Dye and chemical...

  2. A useful single-solution polychrome stain for plant material...Brook Cyte-Chrome I.

    Science.gov (United States)

    Stanley L Krugman; Julia F. Littlefield

    1968-01-01

    Fresh and chemically fixed sectioned plant material can be quickly stained by applying a Brook Cyte Chrome I polychrome stain. Staining time averaged only about 10 minutes. And exact timing of staining and de-staining is not as critical as with most of the commonly used stains. The overall quality is comparable to that of the traditional stains.

  3. Color stability of ceramic brackets immersed in potentially staining solutions.

    Science.gov (United States)

    Guignone, Bruna Coser; Silva, Ludimila Karsbergen; Soares, Rodrigo Villamarim; Akaki, Emilio; Goiato, Marcelo Coelho; Pithon, Matheus Melo; Oliveira, Dauro Douglas

    2015-01-01

    To assess the color stability of five types of ceramic brackets after immersion in potentially staining solutions. Ninety brackets were divided into 5 groups (n = 18) according to brackets commercial brands and the solutions in which they were immersed (coffee, red wine, coke and artificial saliva). The brackets assessed were Transcend (3M/Unitek, Monrovia, CA, USA), Radiance (American Orthodontics, Sheboygan, WI, USA), Mystique (GAC International Inc., Bohemia, NY, USA) and Luxi II (Rocky Mountain Orthodontics, Denver, CO, USA). Chromatic changes were analyzed with the aid of a reflectance spectrophotometer and by visual inspection at five specific time intervals. Assessment periods were as received from the manufacturer (T0), 24 hours (T1), 72 hours (T2), as well as 7 days (T3) and 14 days (T4) of immersion in the aforementioned solutions. Results were submitted to statistical analysis with ANOVA and Bonferroni correction, as well as to a multivariate profile analysis for independent and paired samples with significance level set at 5%. The duration of the immersion period influenced color alteration of all tested brackets, even though these changes could not always be visually observed. Different behaviors were observed for each immersion solution; however, brackets immersed in one solution progressed similarly despite minor variations. Staining became more intense over time and all brackets underwent color alterations when immersed in the aforementioned solutions.

  4. Color stability of ceramic brackets immersed in potentially staining solutions

    Directory of Open Access Journals (Sweden)

    Bruna Coser Guignone

    2015-08-01

    Full Text Available OBJECTIVE: To assess the color stability of five types of ceramic brackets after immersion in potentially staining solutions.METHODS: Ninety brackets were divided into 5 groups (n = 18 according to brackets commercial brands and the solutions in which they were immersed (coffee, red wine, coke and artificial saliva. The brackets assessed were Transcend (3M/Unitek, Monrovia, CA, USA, Radiance (American Orthodontics, Sheboygan, WI, USA, Mystique (GAC International Inc., Bohemia, NY, USA and Luxi II (Rocky Mountain Orthodontics, Denver, CO, USA. Chromatic changes were analyzed with the aid of a reflectance spectrophotometer and by visual inspection at five specific time intervals. Assessment periods were as received from the manufacturer (T0, 24 hours (T1, 72 hours (T2, as well as 7 days (T3 and 14 days (T4 of immersion in the aforementioned solutions. Results were submitted to statistical analysis with ANOVA and Bonferroni correction, as well as to a multivariate profile analysis for independent and paired samples with significance level set at 5%.RESULTS: The duration of the immersion period influenced color alteration of all tested brackets, even though these changes could not always be visually observed. Different behaviors were observed for each immersion solution; however, brackets immersed in one solution progressed similarly despite minor variations.CONCLUSIONS: Staining became more intense over time and all brackets underwent color alterations when immersed in the aforementioned solutions.

  5. Colour stability, staining and roughness of silorane after prolonged chemical challenges

    DEFF Research Database (Denmark)

    Benetti, Ana Raquel; Ribeiro de Jesus, Vivian Cristiane Bueno; Martinelli, Natan Luiz

    2013-01-01

    methacrylate or silorane composites. Specimens were individually stored at 37°C in 0.02 N citric acid, 0.02 N phosphoric acid, 75% ethanol or distilled water for 7, 14, 21 and 180 days, when new measurements were performed. A staining test was performed after the chemical challenge by immersion in coffee...... considered acceptable (although significantly different) after immersion in water, citric acid, phosphoric acid or ethanol, but were unacceptable for the silorane composite immersed in ethanol for 180 days. The methacrylate-based resins stored in ethanol were significantly more stained by coffee than those...... stored in other media. The silorane composite demonstrated no staining, but increased roughness, when compared to the methacrylate-based resins. CONCLUSIONS: No effect of the immersion solution was noticed on roughness of the investigated materials. Ethanol influenced colour stability and staining...

  6. Color stability and staining of silorane after prolonged chemical challenges

    DEFF Research Database (Denmark)

    de Jesus, Vivian CBR; Martinelli, Nata Luiz; Poli-Frederico, Regina Célia

    Objectives: The purpose of this study was to investigate the effect of prolonged chemical challenges on color stability and staining susceptibility of a silorane-based composite material when compared to methacrylate-based composites. Methods: Cylindrical specimens (n=24) were fabricated from...... methacrylate (Filtek Z250, 3M ESPE; Filtek Z350XT, 3M ESPE; Master Fill, Biodinâmica) or silorane-based (Filtek P90, 3M ESPE) composite materials. Initial color was registered in a spectrophotometer. Specimens were divided in four groups and individually stored at 37°C in 0.02N citric acid, 0.02N phosphoric...... acid, 75% ethanol or distilled water (control) for 7, 14, 21, and 180 days, when new measurements were performed. A staining test was performed (n=12) after 21 days of chemical challenge by immersion in coffee during 3 weeks at 37°C. Color changes (¿E) were characterized using the CIEL*a*b* color...

  7. Detection of stain formation on teeth by oral antiseptic solution using fiber optic displacement sensor

    Science.gov (United States)

    Rahman, H. A.; Rahim, H. R. A.; Harun, S. W.; Yasin, M.; Apsari, R.; Ahmad, H.; Wan Abas, W. A. B.

    2013-02-01

    The application of a simple intensity modulated fiber optic displacement sensor for the detection of stain formation on human teeth is demonstrated. The proposed sensor uses a concentric type bundled plastic optical fiber (POF) as a probe in conjunction with the surfaces of five human teeth as the reflecting targets. Prior to the experiment, the stains were produced extrinsically by soaking the teeth in different concentrations of oral antiseptic solution containing hexetidine. The concentration of the oral antiseptic solution is measured in volume%. For a concentration change from 0% to 80%, the peak voltage decreases exponentially from 1.15 mV to 0.41 mV with a measured resolution of 0.48% and 1.75% for concentration ranges of 0-40% and 40-80%, respectively. The correlation between the detector output and variation in the color of human tooth surface has successfully been examined. Simple in design and low in cost, this sensor can detect color changes due to hexetidine-induced stain on a tooth surface in a fast and convenient way. Thus, this sensor will be very promising in esthetic dentistry, dental color matching techniques, chemical and biomedical applications.

  8. The physico-chemical problems involved in condenser cooling, circuit sealing and stain

    International Nuclear Information System (INIS)

    Ropars, Jean.

    1975-01-01

    Today thermal production of electric energy requiers the use of steam turbines and then needs cold sources (condensers), the latter being obtained by means of a water circulation. Considerable amounts of water are involved. For instance, as for a 900MW power plant of the PWR type, a 12 deg C heating needs 40m 3 /s of cooling water. The needs in water introduce a limitation in the possible site selection for power plant settling (seaside or river with an important steady flow). The important amounts of heat involved create environmental problems. Means for limiting the heat amount released consist in using atmospheric cooling systems. A further constraint relating to scaling is added to the usual corrosion and stain problems when operating the devices. Changes in the carbon dioxide equilibrium and concentration due to the passage through the air cooling systems causes such scaling formation. The evolution of the physico-chemical parameters of the cooling water is described with the risks resulting for the circuits. Means to be developed for preventing scaling, stain and corrosion are presented. The solutions kept by E.D.F. for the exploitation of cooling circuits are indicated. The procedure developed must avoid any chemical pollution of water wastes [fr

  9. Standard Test Method to Determine Color Change and Staining Caused by Aircraft Maintenance Chemicals upon Aircraft Cabin Interior Hard Surfaces

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2001-01-01

    1.1 This test method covers the determination of color change and staining from liquid solutions, such as cleaning or disinfecting chemicals or both, on painted metallic surfaces and nonmetallic surfaces of materials being used inside the aircraft cabin. The effects upon the exposed specimens are measured with the AATCC Gray Scale for Color Change and AATCC Gray Color Scale for Staining. Note 1—This test method is applicable to any colored nonmetallic hard surface in contact with liquids. The selected test specimens are chosen because these materials are present in the majority of aircraft cabin interiors. 1.2This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  10. Effect of staining solutions and repolishing on color stability of direct composites

    Directory of Open Access Journals (Sweden)

    Fabrício Mariano Mundim

    2010-06-01

    Full Text Available OBJECTIVES: The purpose of this study was to assess the color change of three types of composite resins exposed to coffee and cola drink, and the effect of repolishing on the color stability of these composites after staining. MATERIALS AND METHODS: Fifteen specimens (15 mm diameter and 2 mm thick were fabricated from microhybrid (Esthet-X; Dentsply and Filtek Z-250; 3M ESPE and high-density hybrid (Surefil; Dentsply composites, and were finished and polished with aluminum oxide discs (Sof-Lex; 3M ESPE. Color of the specimens was measured according to the CIE L*a*b* system in a refection spectrophotometer (PCB 6807; BYK Gardner. After baseline color measurements, 5 specimens of each resin were immersed in different staining solutions for 15 days: G1 - distilled water (control, G2 - coffee, G3 - cola soft drink. Afterwards, new color measurement was performed and the specimens were repolished and submitted to new color reading. Color stability was determined by the difference (ΔE between the coordinates L*, a*, and b* obtained from the specimens before and after immersion into the solutions and after repolishing. RESULTS: There was no statistically signifcant difference (ANOVA, Tukey's test; p>0.05 among the ΔE values for the different types of composites after staining or repolishing. For all composite resins, coffee promoted more color change (ΔE>3.3 than distilled water and the cola soft drink. After repolishing, the ΔE values of the specimens immersed in coffee decreased to clinically acceptable values (ΔE<3.3, but remained signifcantly higher than those of the other groups. CONCLUSIONS: No signifcant difference was found among composite resins or between color values before and after repolishing of specimens immersed in distilled water and cola. Immersing specimens in coffee caused greater color change in all types of composite resins tested in this study and repolishing contributed to decrease staining to clinically acceptable

  11. Effect of finishing and polishing on the color stability of a composite resin immersed in staining solutions

    Directory of Open Access Journals (Sweden)

    Maiara Justo Polli

    2015-01-01

    Full Text Available Objective: To evaluate the influence of finishing/polishing methods and staining solutions using different immersion periods on the color stability of a microhybrid composite resin. Materials and Methods: Ninety specimens were fabricated using a stainless steel mold and polyester strips. The samples were randomly divided into five groups according to the finishing and polishing performed: Control group (no surface treatment was performed, Diamond Pro group, Diamond burs group, Enhance group, and SiC paper group. After finishing and polishing, six samples from each group were immersed in coffee, red wine, or water for 30 days. The color measurements were obtained using digital photography before immersion and after 7, 15, and 30 days of immersion. The red, green, and blue values provided by the Adobe Photoshop software were converted into CIELab values. A three-way analysis of variance and Tukey's test were used for statistical analysis (P ≤ 0.05. Results: The finishing and polishing methods, staining solutions, immersion times, and their interaction had statistically significant effects on the color change (P = 0.00. Coffee and red wine caused intense staining. Among the polishing methods, the highest color change value was observed in the control group (P < 0.05 and the Diamond Pro disks provided the most stain-resistant surfaces (P ≤ 0.05. Conclusion: The finishing and polishing method, staining solution, and immersion time influences the color stability. Finishing and polishing should be applied to obtain a more stain-resistant surface.

  12. The combined effect of food-simulating solutions, brushing and staining on color stability of composite resins

    Science.gov (United States)

    Silva, Tânia Mara Da; Sales, Ana Luísa Leme Simões; Pucci, Cesar Rogerio; Borges, Alessandra Bühler; Torres, Carlos Rocha Gomes

    2017-01-01

    Abstract Objective: This study evaluated the effect of food-simulating media associated with brushing and coffee staining on color stability of different composite resins. Materials and methods: Eighty specimens were prepared for each composite: Grandio SO (Voco), Amaris (Voco), Filtek Z350XT (3M/ESPE), Filtek P90 (3M/ESPE). They were divided into four groups according to food-simulating media for 7 days: artificial saliva (control), heptane, citric acid and ethanol. The composite surface was submitted to 10,950 brushing cycles (200 g load) in an automatic toothbrushing machine. The specimens were darkened with coffee solution at 37 °C for 24 h. After each treatment, color measurements were assessed by spectrophotometry, using CIE L*a*b* system. The overall color change (ΔE) was determined for each specimen at baseline (C1) and after the treatments (food-simulating media immersion/C2, brushing/C3 and dye solution/C4). Data were analyzed by two-way repeated measures ANOVA and Tukey’s tests (p composites (p = .001), time (p = .001) and chemical degradation (p = .002). The mean of ΔE for composites were: Z350XT (5.39)a, Amaris (3.89)b, Grandio (3.75)bc, P90 (3.36)c. According to food-simulating media: heptane (4.41)a, citric acid (4.24)a, ethanol (4.02)ab, artificial saliva (3.76)b. For the treatments: dye solution (4.53)a, brushing (4.26)a, after food-simulating media (3.52)b. Conclusions: The composite resin Filtek Z350XT showed significantly higher staining than all other composite resin tested. The immersion in heptane and citric acid produced the highest color alteration than other food-simulating media. The exposure of samples to brushing protocols and darkening in coffee solution resulted in significant color alteration of the composite resins. PMID:28642926

  13. Enamels in stained glass windows: Preparation, chemical composition, microstructure and causes of deterioration

    International Nuclear Information System (INIS)

    Schalm, O.; Van der Linden, V.; Frederickx, P.; Luyten, S.; Van der Snickt, G.; Caen, J.; Schryvers, D.; Janssens, K.; Cornelis, E.; Van Dyck, D.; Schreiner, M.

    2009-01-01

    Stained glass windows incorporating dark blue and purple enamel paint layers are in some cases subject to severe degradation while others from the same period survived the ravages of time. A series of dark blue, green-blue and purple enamel glass paints from the same region (Northwestern Europe) and from the same period (16-early 20th centuries) has been studied by means of a combination of microscopic X-ray fluorescence analysis, electron probe micro analysis and transmission electron microscopy with the aim of better understanding the causes of the degradation. The chemical composition of the enamels diverges from the average chemical composition of window glass. Some of the compositions appear to be unstable, for example those with a high concentration of K 2 O and a low content of CaO and PbO. In other cases, the deterioration of the paint layers was caused by the less than optimal vitrification of the enamel during the firing process. Recipes and chemical compositions indicate that glassmakers of the 16-17th century had full control over the color of the enamel glass paints they made. They mainly used three types of coloring agents, based on Co (dark blue), Mn (purple) and Cu (light-blue or green-blue) as coloring elements. Blue-purple enamel paints were obtained by mixing two different coloring agents. The coloring agent for red-purple enamel, introduced during the 19th century, was colloidal gold embedded in grains of lead glass.

  14. Influence of staining solutions and whitening procedures on discoloration of hybrid composite resins.

    Science.gov (United States)

    Garoushi, Sufyan; Lassila, Lippo; Hatem, Marwa; Shembesh, Muneim; Baady, Lugane; Salim, Ziad; Vallittu, Pekka

    2013-01-01

    The aim was to evaluate the color stability and water uptake of two hybrid composite resins polymerized in two different conditions after exposure to commonly consumed beverages. In addition, the effect of repolishing and bleaching on the stained composite was evaluated. Eighty specimens (12 mm × 12 mm × 3 mm) were made from two hybrid composite resins of shade A2. Forty specimens of each composite were divided into two groups (n = 20 per each) according to the curing method used (hand light cure HLC or oven light cure OLC). Then each group (HLC or OLC) was sub-divided randomly into four sub-groups (n = 5), which were immersed for 60 days in different beverages (distal water, coffee, tea and pepsi) and incubated at 37°C. Water uptake was measured during this time and followed by measurement of color difference (ΔE) by using a spectrophotometer. After complete staining, repolishing (grit 4000 FEPA at 300 rpm under water) and bleaching (40% hydrogen peroxide bleaching gel) were conducted. The repolished and bleached specimens were submitted to new color measurements. Color value of the specimens immersed in tea displayed the highest statistically significant (p pepsi was significantly lower than the others. After staining of the composite resins, both the bleaching and repolishing were able to reduce the ΔE value. All beverages used affected the color stability of tested composite resins. The effect of beverages on color change of composites depends on type of beverage and water uptake value of resins used. A superior whitening effect was obtained with repolishing technique compared to bleaching.

  15. Waste processing of chemical cleaning solutions

    International Nuclear Information System (INIS)

    Peters, G.A.

    1991-01-01

    This paper reports on chemical cleaning solutions containing high concentrations of organic chelating wastes that are difficult to reduce in volume using existing technology. Current methods for evaporating low-level radiative waste solutions often use high maintenance evaporators that can be costly and inefficient. The heat transfer surfaces of these evaporators are easily fouled, and their maintenance requires a significant labor investment. To address the volume reduction of spent, low-level radioactive, chelating-based chemical cleaning solutions, ECOSAFE Liquid Volume Reduction System (LVRS) has been developed. The LVRS is based on submerged combustion evaporator technology that was modified for treatment of low-level radiative liquid wastes. This system was developed in 1988 and was used to process 180,000 gallons of waste at Oconee Nuclear Station

  16. Characterization of stain etched p-type silicon in aqueous HF solutions containing HNO{sub 3} or KMnO{sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Mogoda, A.S., E-mail: awad_mogoda@hotmail.com [Department of Chemistry, Faculty of Science, Cairo University, Giza (Egypt); Ahmad, Y.H.; Badawy, W.A. [Department of Chemistry, Faculty of Science, Cairo University, Giza (Egypt)

    2011-04-15

    Research highlights: {yields} Stain etching of p-Si in aqueous HF solutions containing HNO{sub 3} or KMnO{sub 4} was investigated. {yields} The electrical conductivity of the etched Si surfaces was measured using impedance technique. {yields} Scanning electron microscope and energy disperse X-ray were used to analyze the etched surfaces. {yields} Etching in aqueous HF solution containing HNO{sub 3} led to formation of a porous silicon layer. {yields} The formation of the porous silicon layer in HF/KMnO{sub 4} was accompanied by deposition of K{sub 2}SiF{sub 6} on the pores surfaces. - Abstract: Stain etching of p-type silicon in hydrofluoric acid solutions containing nitric acid or potassium permanganate as an oxidizing agent has been examined. The effects of etching time, oxidizing agent and HF concentrations on the electrochemical behavior of etched silicon surfaces have been investigated by electrochemical impedance spectroscopy (EIS). An electrical equivalent circuit was used for fitting the impedance data. The morphology and the chemical composition of the etched Si surface were studied using scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) techniques, respectively. A porous silicon layer was formed on Si etched in HF solutions containing HNO{sub 3}, while etching in HF solutions containing KMnO{sub 4} led to the formation of a porous layer and simultaneous deposition of K{sub 2}SiF{sub 6} inside the pores. The thickness of K{sub 2}SiF{sub 6} layer increases with increasing the KMnO{sub 4} concentration and decreases as the concentration of HF increases.

  17. Solutal Marangoni flow as the cause of ring stains from drying salty colloidal drops

    Science.gov (United States)

    Marin, Alvaro; Karpitschka, Stefan; Rossi, Massimiliano; Kaehler, Christian J.; Noguera-Marin, Diego; Rodriguez-Valverde, Miguel A.

    2017-11-01

    Salts can be found in different forms in almost any evaporating droplet in nature, our homes and in laboratories. The transport processes in such apparently simple systems differ strongly from `sweet' evaporating droplets since the liquid flows in the inverse direction due to Marangoni stresses at the surface. Such an effect has crucial consequences to salt crystallization processes and to the evaporation itself. In this work we show measurements that not only confirm clearly the details of the inverted flow patterns, but also permit us to calculate the surface tension gradients responsible for the reversal. Such a reversal does not prevent the coffee-stain effect; on the contrary, particles accumulate and get trapped at the liquid-air interface driven by the surface flow. In order to prove this, we show measurements of the full three-dimensional flow inside the evaporating salty droplet, confocal imaging is used to quantify the growth of the particle deposits for different salt concentrations, and we compare the experimental results with numerical simulations that capture the solvent evaporation, the evaporation-induced liquid flow and the quasi-equilibrium liquid-gas interface.

  18. Fractal solutions of recirculation tubular chemical reactors

    International Nuclear Information System (INIS)

    Berezowski, Marek

    2003-01-01

    Three kinds of fractal solutions of model of recirculation non-adiabatic tubular chemical reactors are presented. The first kind concerns the structure of Feigenbaum's diagram on the limit of chaos. The second kind and the third one concern the effect of initial conditions on the dynamic solutions of models. In the course of computations two types of recirculation were considered, viz. the recirculation of mass (return of a part of products' stream) and recirculation of heat (heat exchange in the external heat exchanger)

  19. Chemicals in Household Products: Problems with Solutions

    Science.gov (United States)

    Glegg, Gillian A.; Richards, Jonathan P.

    2007-12-01

    The success of a regulatory regime in decreasing point-source emissions of some harmful chemicals has highlighted the significance of other sources. A growing number of potentially harmful chemicals have been incorporated into an expanding range of domestic household products and are sold worldwide. Tighter regulation has been proposed, and the European Commission has introduced the Regulation on the Registration, Evaluation, and Authorisation of Chemicals to address this concern. However, it is clear that in addition to the regulation, there is a potential to effect change through retailer and consumer attitudes and behaviours. Interviews were conducted with 7 key stakeholder groups to identify critical issues, which were then explored using a public survey questionnaire (1,008 respondents) and 8 subsequent focus groups. The findings demonstrated that the issue of chemicals in products is of concern to consumers for reasons of personal health rather than environmental protection. Key obstacles to the wider purchase of “green-alternative” products included perceived high cost and poor performance, lack of availability of products, and poor information concerning such products. Although improved regulation was seen as part of the solution, consumers must also play a role. It was clear from this study that consumers are not currently able to make informed choices about the chemicals they use but that they would be receptive to moving toward a more sustainable use of chemicals in the future if empowered to do so.

  20. Chemical deposition methods using supercritical fluid solutions

    Science.gov (United States)

    Sievers, Robert E.; Hansen, Brian N.

    1990-01-01

    A method for depositing a film of a desired material on a substrate comprises dissolving at least one reagent in a supercritical fluid comprising at least one solvent. Either the reagent is capable of reacting with or is a precursor of a compound capable of reacting with the solvent to form the desired product, or at least one additional reagent is included in the supercritical solution and is capable of reacting with or is a precursor of a compound capable of reacting with the first reagent or with a compound derived from the first reagent to form the desired material. The supercritical solution is expanded to produce a vapor or aerosol and a chemical reaction is induced in the vapor or aerosol so that a film of the desired material resulting from the chemical reaction is deposited on the substrate surface. In an alternate embodiment, the supercritical solution containing at least one reagent is expanded to produce a vapor or aerosol which is then mixed with a gas containing at least one additional reagent. A chemical reaction is induced in the resulting mixture so that a film of the desired material is deposited.

  1. Color stability of sealed composite resin restorative materials after ultraviolet artificial aging and immersion in staining solutions.

    Science.gov (United States)

    Catelan, Anderson; Briso, André Luiz Fraga; Sundfeld, Renato Hermann; Goiato, Marcelo Coelho; dos Santos, Paulo Henrique

    2011-04-01

    The color alteration of resin-based materials is one of the most common reasons to replace esthetic dental restorations. This study assessed the influence of surface sealant (Biscover) on the color stability of nanofilled (Supreme XT) and microhybrid (Vit-l-escence and Opallis) composite resins after artificial aging. One hundred disc-shaped (6 × 1.5 mm) specimens were made for each composite resin. After 24 hours, all specimens were polished and sealant was applied to 50 specimens of each material. Baseline color was measured according to the CIE L*a*b* system using a reflection spectrophotometer. Ten specimens of each group were aged for 252 h in an ultraviolet (UV)-accelerated aging chamber or immersed for 4 weeks in cola soft drink, orange juice, red wine staining solutions or distilled water as control. Color difference (ΔE) after aging was calculated based on the color coordinates before (baseline) and after aging/staining treatment. Data were analyzed with 2-way ANOVA and Fisher's test (α=.05). The results showed significant changes in color after artificial aging in all the groups (Paging, and the cola soft drink. The lowest values of ΔE were found for specimens stored in distilled water. All composite resins showed some color alteration after the aging methods. The surface sealant did not alter the color stability of the tested materials. Copyright © 2011 The Editorial Council of the Journal of Prosthetic Dentistry. Published by Mosby, Inc. All rights reserved.

  2. Chemical denitration of aqueous nitrate solutions

    International Nuclear Information System (INIS)

    Burrill, K.A.

    1987-11-01

    The Plant for Active Waste Liquids (PAWL) at CRNL will immobilize in glass the fission products in waste from Mo-99 production. The nitrate ions in the waste can be destroyed by heating, but also by chemical reaction with formic acid (HCOOH). Since chemical denitration has several advantages over thermal denitration it was studied in the course of vitrification process development. Two free radical mechanisms are examined here to explain kinetic data on chemical denitration of nitric acid solutions with formic acid. One mechanism is applicable at > 1 mol/L HNO 3 and involves the formate radical (HCOO . ). The second mechanism holds at 3 and involves the hyponitrous radical (HNO . ). Mass balances for various species were written based on the law of mass action applied to the equations describing the reaction mechanism. Analytical and numerical solutions were obtained and compared. Literature data on batch denitration were used to determine some of the rate constants while others were set arbitrarily. Observed stoichiometry and trends in reactant concentrations are predicted accurately for batch data. There are no literature data to compare with the prediction of negligible induction time

  3. Ultrasonic filtration of industrial chemical solutions

    Science.gov (United States)

    Cosma, T.

    1974-01-01

    The practical results obtained as a result of filtering industrial chemical solutions under continuous flow conditions with the aid of an ultrasonic filter are presented. The main part of the assembly consists of an ultrasonic generator with an output power of about 400 W and the filtration assembly, in which there is a magnetostrictive amplifier constructed for 20.5 kHz. In addition to ensuring a continuous flow of filtered solution, ultrasonic filters can be replaced or cleaned at intervals of time that are 8-10 times greater than in the case of mechanical filters. They yield considerably better results as far as the size of the filtered particles is concerned. The parameters on which filtration quality depends are also presented.

  4. Iron Stain on Wood

    Science.gov (United States)

    Mark Knaebe

    2013-01-01

    Iron stain, an unsightly blue–black or gray discoloration, can occur on nearly all woods. Oak, redwood, cypress, and cedar are particularly prone to iron stain because these woods contain large amounts of tannin-like extractives. The discoloration is caused by a chemical reaction between extractives in the wood and iron in steel products, such as nails, screws, and...

  5. Chemical characterization of the stained glass window from the rose window, Siena Duomo (Italy, 1288-1289)

    Energy Technology Data Exchange (ETDEWEB)

    Gimeno, D.; Aulinas, M.; Bazzocchi, F.; Fernandez-Turiel, J. L.; Garcia-Valles, M.; Novembre, D.; Basso, E.; Messiga, B.; Riccardi, M. P.; Tarozzi, C.; Mendera, M.

    2010-07-01

    The chemical composition of nine medieval coloured stained glasses from Duomo (Catedral) of Siena, Italy, has been characterized. They come from the rose window elaborated under the drawing of Duccio di Buoninsegna masterwork (1288- 89 AD). This note explains the results obtained by EMPA, representative of bulk chemistry of several coloured glasses (deep green, olive green, yellow, purple, pink, deep blue, light blue, red plaque and also uncoloured), as well as the associated trace elements (obtained by Induced Coupled Plasma Mass Spectrometry) that represent the chemical fingerprint of these glasses. The studied samples are sodium-calcium glass (chemical compositions in the range 13-14 wt% Na{sub 2}O, 56-64 wt% SiO{sub 2}, 4 wt% MgO, 9-10 wt% CaO, 2,5-4 wt% K{sub 2}O); thus of Mediterranean tradition.This fact has been found by our team in previous studies (stained glasses from the church of Monestir de Pedralbes, Barcelona) for XIV century glass made at least 40 years later. As a general rule, the conservation state of these sodium glasses is good, except for the cohesion of grisaille to glass mesostase. This study allowed to identify three glass groups developed from different raw material formulations: a first group is constituted by deep green, olive green, light blue and yellow glass; a second one comprises by uncoloured, deep purple, deep blue and pink glass; and finally, the plaque red glass that shows deeply different composition. Pink and yellow glass was produced following the traditional recipe compiled by Theophilus, a monk who lived at the beginning of XII century. This implies a separate process of raw material purification and a careful control of the redox kiln conditions; thus, these glasses can be considered as traditional or technologically not evolved. The deep blue, light blue and deep purple were obtained after the artisan dosed addition of a cobalt salt. Olive green and deep green glasses were produced with addition of copper (together with

  6. Microscopic, chemical, and molecular-biological investigation of the decayed medieval stained window glasses of two Catalonian churches.

    Science.gov (United States)

    Piñar, Guadalupe; Garcia-Valles, Maite; Gimeno-Torrente, Domingo; Fernandez-Turiel, Jose Luis; Ettenauer, Jörg; Sterflinger, Katja

    2013-10-01

    We investigated the decayed historical church window glasses of two Catalonian churches, both under Mediterranean climate. Glass surfaces were studied by scanning electron microscopy (SEM), energy dispersive spectrometry (EDS), and X-ray diffraction (XRD). Their chemical composition was determined by wavelength-dispersive spectrometry (WDS) microprobe analysis. The biodiversity was investigated by molecular methods: DNA extraction from glass, amplification by PCR targeting the16S rRNA and ITS regions, and fingerprint analyses by denaturing gradient gel electrophoresis (DGGE). Clone libraries containing either PCR fragments of the bacterial 16S rDNA or the fungal ITS regions were screened by DGGE. Clone inserts were sequenced and compared with the EMBL database. Similarity values ranged from 89 to 100% to known bacteria and fungi. Biological activity in both sites was evidenced in the form of orange patinas, bio-pitting, and mineral precipitation. Analyses revealed complex bacterial communities consisting of members of the phyla Proteobacteria, Bacteroidetes, Firmicutes, and Actinobacteria. Fungi showed less diversity than bacteria, and species of the genera Cladosporium and Phoma were dominant. The detected Actinobacteria and fungi may be responsible for the observed bio-pitting phenomenon. Moreover, some of the detected bacteria are known for their mineral precipitation capabilities. Sequence results also showed similarities with bacteria commonly found on deteriorated stone monuments, supporting the idea that medieval stained glass biodeterioration in the Mediterranean area shows a pattern comparable to that on stone.

  7. Prediction of wood mechanical and chemical properties in the presence and absence of blue stain using two near infrared instruments

    Science.gov (United States)

    Brian K. Via; Chi-Leung So; Todd F. Shupe; Lori G. Eckhardt; Michael Stine; Leslie H. Groom

    2005-01-01

    The objective of this research was to (a) determine if blue stain in solid wood influenced calibration equations developed from a nonstained wood population, (b) assess the bias introduced when scanning was performed by the slave instrument without calibration transfer from the master instrument and (c) partition absorbance-based variation by instrument, stain and...

  8. Gram staining.

    Science.gov (United States)

    Coico, Richard

    2005-10-01

    Named after Hans Christian Gram who developed the method in 1884, the Gram stain allows one to distinguish between Gram-positive and Gram-negative bacteria on the basis of differential staining with a crystal violet-iodine complex and a safranin counterstain. The cell walls of Gram-positive organisms retain this complex after treatment with alcohol and appear purple, whereas gram-negative organisms decolorize following such treatment and appear pink. The method described here is useful for assessing bacterial contamination of tissue culture samples or for examining the Gram stain status and morphological features of bacteria isolated from mixed or isolated bacterial cultures.

  9. Chemical stability of oseltamivir in oral solutions.

    Science.gov (United States)

    Albert, K; Bockshorn, J

    2007-09-01

    The stability of oseltamivir in oral aqueous solutions containing the preservative sodium benzoate was studied by a stability indicating HPLC-method. The separation was achieved on a RP-18 ec column using a gradient of mobile phase A (aqueous solution of 50 mM ammonium acetate) and mobile phase B (60% (v/v) acetonitrile/40% (v/v) mobile phase A). The assay was subsequently validated according to the ICH guideline Q2(R1). The extemporaneously prepared "Oseltamivir Oral Solution 15 mg/ml for Adults or for Children" (NRF 31.2.) according to the German National Formulary ("Neues Rezeptur-Formularium") was stable for 84 days if stored under refrigeration. After storage at 25 degrees C the content of oseltamivir decreased to 98.4%. Considering the toxicological limit of 0.5% of the 5-acetylamino derivative (the so-called isomer I) the solution is stable for 46 days. Oseltamivir was less stable in a solution prepared with potable water instead of purified water. Due to an increasing pH the stability of this solution decreased to 14 days. Furthermore a white precipitate of mainly calcium phosphate was observed. The addition of 0.1% anhydrous citric acid avoided these problems and improved the stability of the solution prepared with potable water to 63 days. Sodium benzoate was stable in all oral solutions tested.

  10. Chemical-milling solution for invar alloy

    Science.gov (United States)

    Batiuk, W.

    1980-01-01

    Excellent surface finishes and tolerances are achieved using two formulations. Solution A gives finish of 3.17 micrometers after milling at 57 to 63 deg C. Constituents of A are: Hydrofluoric acid (70%), 5,8 oz/gal; nitric acid (40-42) degrees Baume), 40 oz/gal. Alternative solution gives 2.16 micrometer finish, and differs from A by addition of 7% phosphoric acid. Formulations eliminate channeling at root fillets, dishing, island formation, and overhangs.

  11. Chemical decontamination solutions: Effects on PWR equipment

    International Nuclear Information System (INIS)

    Pezze, C.M.; Colvin, E.R.; Aspden, R.G.

    1992-01-01

    A critical objective for the nuclear industry is the reduction of personnel exposure to radiation. Reductions have been achieved through industry's radiation management programs including training and radiation awareness concepts. Increased plant maintenance and higher radiation fields at many sites continue to raise concerns. To alleviate the radiation exposure problem, the sources of radiation which contribute to personnel exposure must be removed from the plant. A feasible was of significantly reducing these sources from a Pressurized Water Reactor (PWR) is to chemically decontaminate the entire reactor coolant system (RCS). A program was conducted to determine the technical acceptability of using certain dilute chemical solvent processes for full RCS chemical decontamination. The two processes evaluated were CAN-DEREM and LOMI. The purpose of the program was to define and complete a systematic evaluation of the major issues that need to be addressed for the successful decontamination of the entire RCS and affected portions of the auxiliary systems of a four-loop PWR system. A test program was designed to evaluate the corrosion effects of the two decontamination processes under expected plant conditions. Materials and sample configurations dictated by generic PWR components were evaluated. The testing also included many standard corrosion coupons. The test data were then used to assess the impact of chemical decontamination on the physical condition and operability of the components, equipment and mechanical systems that make up the RCS. An overview of the test program, sample configurations, data and engineering evaluations is presented. The data demonstrate that through detailed engineering evaluations of corrosion data and equipment function, the impact of full RCS chemical decontamination on plant equipment is established

  12. Chemical Solutions of Fire Protection Problems

    Directory of Open Access Journals (Sweden)

    Vakhitova, L.M.

    2015-11-01

    Full Text Available The modern approaches to the creation of fire protective coatings by modifying intumescent systems by nanomaterials with study of the chemical reaction mechanisms under the high temperatures influence were considered. A systematic study of the interactions of components of polyphosphate type intumescent blend were carried out, a well-defined correlations between the directions of chemical processes and fire retardant properties of intumescent coatings were found. Efficient ways to simultaneous increase of fireprotective efficiency and performance characteristics of intumescent coatings (operatin life, resistance to environmental factors and bioсontamination were proposed. The results of fundamental research allowed to develop new formulations of flame retardant compositions, whose properties have been confirmed by tests in accordance with existing standardized methods, these results were introduced into production.

  13. Coupling between solute transport and chemical reactions models

    International Nuclear Information System (INIS)

    Samper, J.; Ajora, C.

    1993-01-01

    During subsurface transport, reactive solutes are subject to a variety of hydrodynamic and chemical processes. The major hydrodynamic processes include advection and convection, dispersion and diffusion. The key chemical processes are complexation including hydrolysis and acid-base reactions, dissolution-precipitation, reduction-oxidation, adsorption and ion exchange. The combined effects of all these processes on solute transport must satisfy the principle of conservation of mass. The statement of conservation of mass for N mobile species leads to N partial differential equations. Traditional solute transport models often incorporate the effects of hydrodynamic processes rigorously but oversimplify chemical interactions among aqueous species. Sophisticated chemical equilibrium models, on the other hand, incorporate a variety of chemical processes but generally assume no-flow systems. In the past decade, coupled models accounting for complex hydrological and chemical processes, with varying degrees of sophistication, have been developed. The existing models of reactive transport employ two basic sets of equations. The transport of solutes is described by a set of partial differential equations, and the chemical processes, under the assumption of equilibrium, are described by a set of nonlinear algebraic equations. An important consideration in any approach is the choice of primary dependent variables. Most existing models cannot account for the complete set of chemical processes, cannot be easily extended to include mixed chemical equilibria and kinetics, and cannot handle practical two and three dimensional problems. The difficulties arise mainly from improper selection of the primary variables in the transport equations. (Author) 38 refs

  14. Determination of chemical solute transport parameters effecting radiostrontium interbed sediments

    International Nuclear Information System (INIS)

    Hemming, C.; Bunde, R.L.; Rosentreter, J.J.

    1993-01-01

    The extent to which radionuclides migrate in an aquifer system is a function of various physical, chemical, and biological processes. A measure of this migration rate is of primary concern when locating suitable storage sites for such species. Parameters including water-rock interactions, infiltration rates, chemical phase modification, and biochemical reactions all affect solute transport. While these different types of chemical reactions can influence solute transport in subsurface waters, distribution coefficients (Kd) can be send to effectively summarize the net chemical factors which dictate transport efficiency. This coefficient describes the partitioning of the solute between the solution and solid phase. Methodology used in determining and interpreting the distribution coefficient for radiostrontium in well characterized sediments will be presented

  15. Chemical solution deposition of functional oxide thin films

    CERN Document Server

    Schneller, Theodor; Kosec, Marija

    2014-01-01

    Chemical Solution Deposition (CSD) is a highly-flexible and inexpensive technique for the fabrication of functional oxide thin films. Featuring nearly 400 illustrations, this text covers all aspects of the technique.

  16. Chemical milling solution produces smooth surface finish on aluminum

    Science.gov (United States)

    Lorenzen, H. C.

    1966-01-01

    Elementary sulfur mixed into a solution of caustic soda and salts produces an etchant which will chemically mill end-grain surfaces on aluminum plate. This composition results in the least amount of thickness variation and pitting.

  17. Chemical colostomy irrigation with glyceryl trinitrate solution.

    Science.gov (United States)

    O'Bichere, A; Bossom, C; Gangoli, S; Green, C; Phillips, R K

    2001-09-01

    Colostomy irrigation may improve patient quality of life, but is time consuming. This study tests the hypothesis that irrigation with glyceryl trinitrate solution, by inducing gastrointestinal smooth muscle relaxation, may accelerate expulsion of stool by passive emptying, thereby reducing irrigation time. Fifteen colostomy irrigators(with more than 3 years' experience) performed washout with tap water compared with water containing 0.025 mg/kg glyceryl trinitrate. Fluid inflow time, total washout time, and hemodynamic changes occurring during glyceryl trinitrate irrigation were documented by an independent observer. Subjects recorded episodes of fecal leakage and overall satisfaction on a visual analog scale. Cramps, headaches, and whether or not a stoma bag was used were expressed as a percentage of number of irrigations. Comparison of fluid inflow time, total washout time, leakage, and satisfaction was by Wilcoxon's signed-rank test and headaches, cramps, and stoma bag use was by McNemar's test. Pulse rate (paired t-test), systolic and diastolic blood pressures (Wilcoxon's test) at 20 and 240 minutes after washout with glyceryl trinitrate solution were compared with baseline. Fifteen patients (9 female), with a mean age of 53 (31-73) years, provided 30 sessions (15 with water and 15 with glyceryl trinitrate). Medians (interquartile ranges) for water vs. glyceryl trinitrate were fluid inflow time 7 (4-10) vs. 4, (3-5; P = 0.001); total washout time 40 (30-55) vs. 21, (15-24; P colostomy irrigation time compared with the generally recommended tap water. Patients suffer fewer leakages and are highly satisfied, but side effects are potential drawbacks. Other colonoplegic agent solutions should now be evaluated.

  18. Modeling Complex Chemical Systems: Problems and Solutions

    Science.gov (United States)

    van Dijk, Jan

    2016-09-01

    Non-equilibrium plasmas in complex gas mixtures are at the heart of numerous contemporary technologies. They typically contain dozens to hundreds of species, involved in hundreds to thousands of reactions. Chemists and physicists have always been interested in what are now called chemical reduction techniques (CRT's). The idea of such CRT's is that they reduce the number of species that need to be considered explicitly without compromising the validity of the model. This is usually achieved on the basis of an analysis of the reaction time scales of the system under study, which identifies species that are in partial equilibrium after a given time span. The first such CRT that has been widely used in plasma physics was developed in the 1960's and resulted in the concept of effective ionization and recombination rates. It was later generalized to systems in which multiple levels are effected by transport. In recent years there has been a renewed interest in tools for chemical reduction and reaction pathway analysis. An example of the latter is the PumpKin tool. Another trend is that techniques that have previously been developed in other fields of science are adapted as to be able to handle the plasma state of matter. Examples are the Intrinsic Low Dimension Manifold (ILDM) method and its derivatives, which originate from combustion engineering, and the general-purpose Principle Component Analysis (PCA) technique. In this contribution we will provide an overview of the most common reduction techniques, then critically assess the pros and cons of the methods that have gained most popularity in recent years. Examples will be provided for plasmas in argon and carbon dioxide.

  19. Chemical solution deposition techniques for epitaxial growth of complex oxides

    NARCIS (Netherlands)

    ten Elshof, Johan E.; Koster, G.; Huijben, Mark; Rijnders, G.

    2015-01-01

    The chemical solution deposition (CSD) process is a wet-chemical process that is employed to fabricate a wide variety of amorphous and crystalline oxide thin films. This chapter describes the typical steps in a CSD process and their influence on the final microstructure and properties of films, and

  20. COMPARISON OF HEMATOXYLIN AND EOSIN STAINING WITH AND WITHOUT PRE TREATMENT WITH MARCHI’S SOLUTION ON NERVE SAMPLES FOR NERVE DEGENERATION AND REGENERATION STUDIES

    Directory of Open Access Journals (Sweden)

    Malik Abu Rafee

    2017-12-01

    Full Text Available The study was conducted on four healthy guinea pigs (Cavia porcellus of either sex in which the nerve was identified and subjected to crush injury with the tip (3mm of a curved hemostatic forceps. 30 days after the injury nerve samples were collected and subjected to Hematoxylin and Eosin staining with or without pretreatment with Marchi’s solution. The routine Hematoxylin and Eosin (H&E stained all neural elements in various intensities of pink and in purple and the degenerative changes were seen as vacuoles ranging from vacuolated foci- containing eosinophilic material and associated with a distorted cell nucleus to larger, multilocular, linear array of compartmentalized digestion chambers supposed to contain myelin debris .The myelin on the other hand appeared as empty zones in H&E staining. Combining Marchi’s and H & E procedures revealed the presence black aggregates/ deposits in the vacuoles and digestion chambers. This method confirmed the presence of degenerated myelin inside the vacuoles and digestion chambers and thus may allow better analysis of nerve damage and regeneration.

  1. Electrical Conductivity and Chemical Composition of Soil Solution: Comparison of Solution Samplers in Tropical Soils

    Directory of Open Access Journals (Sweden)

    Davi Lopes do Carmo

    2016-01-01

    Full Text Available ABSTRACT Soil solution samplers may have the same working principle, but they differ in relation to chemical and physical characteristics, cost and handling, and these aspects exert influence on the chemical composition of the soil solution obtained. This study was carried out to evaluate, over time, the chemical composition of solutions extracted by Suolo Acqua, with the hydrophilic membrane (HM as a standard, using soils with contrasting characteristics, and to determine the relationship between electrical conductivity (EC and concentration of ions and pH of soil solution samples. This study was carried out under laboratory conditions, using three soils samples with different clay and organic matter (OM contents. Soil solution contents of F−, Cl−, NO−3, Br−, SO42−, Na+, NH4+, K+, Mg2+, Ca2+, were analyzed, as well as inorganic, organic, and total C contents, pH, and EC, in four successive sampling times. Soil solution chemical composition extracted by the Suolo Acqua sampler is similar to that collected by the HM, but the Suolo Acqua extracted more Na+ and soluble organic C than the HM solution. Solution EC, cation and anion concentrations, and soluble C levels are higher in the soil with greater clay and OM contents (Latossolo and Cambissolo in this case. Soil solution composition varied over time, with considerable changes in pH, EC, and nutrient concentrations, especially associated with soil OM. Thus, single and isolated sampling of the soil solution must be avoided, otherwise composition of the soil solution may not be correctly evaluated. Soil solution EC was regulated by pH, as well as the sum of cation and anion concentrations, and the C contents determined in the soil liquid phase.

  2. Ions in solution basic principles of chemical interactions

    CERN Document Server

    Burgess, J

    1999-01-01

    This outline of the principles and chemical interactions in inorganic solution chemistry delivers a course module in an area of considerable complexity. Problems with solutions and tutorial hints to test comprehension have been added as a feature to check readers' understanding and assist self-study. Exercises and projects are also provided to help readers deepen and extend their knowledge and understanding. Inorganic solution chemistry is treated thoroughly Emphasis is placed upon NMR, UV-VIS, IR Raman spectroscopy, X-ray diffraction, and such topics as acid-base behaviour, stability constants and kinetics.

  3. A New Topology of Solutions of Chemical Equations

    International Nuclear Information System (INIS)

    Risteski, Ice B.

    2013-01-01

    In this work is induced a new topology of solutions of chemical equations by virtue of point-set topology in an abstract stoichiometrical space. Subgenerators of this topology are the coefficients of chemical reaction. Complex chemical reactions, as those of direct reduction of hematite with a carbon, often exhibit distinct properties which can be interpreted as higher level mathematical structures. Here we used a mathematical model that exploits the stoichiometric structure, which can be seen as a topology too, to derive an algebraic picture of chemical equations. This abstract expression suggests exploring the chemical meaning of topological concept. Topological models at different levels of realism can be used to generate a large number of reaction modifications, with a particular aim to determine their general properties. The more abstract the theory is, the stronger the cognitive power is

  4. Molecular dynamics simulations of solutions at constant chemical potential

    Science.gov (United States)

    Perego, C.; Salvalaglio, M.; Parrinello, M.

    2015-04-01

    Molecular dynamics studies of chemical processes in solution are of great value in a wide spectrum of applications, which range from nano-technology to pharmaceutical chemistry. However, these calculations are affected by severe finite-size effects, such as the solution being depleted as the chemical process proceeds, which influence the outcome of the simulations. To overcome these limitations, one must allow the system to exchange molecules with a macroscopic reservoir, thus sampling a grand-canonical ensemble. Despite the fact that different remedies have been proposed, this still represents a key challenge in molecular simulations. In the present work, we propose the Constant Chemical Potential Molecular Dynamics (CμMD) method, which introduces an external force that controls the environment of the chemical process of interest. This external force, drawing molecules from a finite reservoir, maintains the chemical potential constant in the region where the process takes place. We have applied the CμMD method to the paradigmatic case of urea crystallization in aqueous solution. As a result, we have been able to study crystal growth dynamics under constant supersaturation conditions and to extract growth rates and free-energy barriers.

  5. Chemical nickel plating in tartrate solutions with borohydride reducing agent

    International Nuclear Information System (INIS)

    Plokhov, V.A.

    1986-01-01

    The authors investigate the influence of various factors on the rate of chemical nickel plating in strongly alkaline tartrate solutions with a borohydride reducing agent. After 30 min of the process of nickel plating, the final concentration of sodium borohydride decreases to 0.26 g/liter, leading to stoppage of the process. The nickel plating process can be intensified by increasing the concentration of sodium hydroxide in the solution, suppressing hydrolysis of borohydride, and also by introducing additives which suppress hydrolysis of borohydride. For chemical deposition of nickel-boron coatings from tartrate solutions the authors recommend the following composition (g/liter): nickel chloride 15-25, Rochelle salt 450-550, sodium hydroxide 140-160, sodium borohydride 0.8-1.0, thallium nitrate 0.003-0.008. The process temperature is 92-95 C, and the deposition rate is 4-6 um/h

  6. Six-month color change and water sorption of 9 new-generation flowable composites in 6 staining solutions

    Directory of Open Access Journals (Sweden)

    Maria ARREGUI

    Full Text Available Abstract Color match and water sorption are two factors that affect restorative materials. Discoloration is essential in the lifespan of restorations. The aim of this study was to evaluate color change and water sorption of nine flowable composites at multiple time points over 6 months. 60 samples of each composite were divided into two groups (Color Change and Water Sorption/Solubility. Each Color Change group was divided into six subgroups, which were immersed in distilled water (DW, coffee (CF, Coca-Cola (CC, red wine (RW, tea (TE and orange juice (OJ. The color was measured at the baseline, 1, 2, 3 and 4 weeks, and 3 and 6 months and color change values (ΔE were calculated. Each Water Sorption [WS]/Solubility [WL] group was tested according to ISO 4049:2009. The data were evaluated using two-way ANOVA, Fisher’s post-hoc test and Pearson’s correlation test. The composite with the lowest ΔE differed for each solution: Filtek™ Bulk Fill in DW (∆E = 0.73 (0.17–1.759; Vertise Flow in CF (∆E = 14.75 (7.91–27.41, in TE (∆E = 7.27 (2.81–24.81 and OJ (∆E = 3.17 (0.87–9.92; Tetric EvoFlow® in CC (∆E = 1.27 (0.45–4.02; and Filtek™ Supreme XTE in RW (∆E = 8.88 (5.23–19.59. RW caused the most discoloration (∆E = 23.62 (4.93–51.36. Vertise Flow showed the highest water sorption (WS = 69.10 ± 7.19. The Pearson test showed statistically significant positive correlations between water sorption and solubility and between water sorption and ∆E; the positive solubility-∆E correlation was not statistically significant. The findings suggest that water sorption is one factor associated with the ability of composites to discolor; however, discoloration is a multifactorial problem.

  7. Six-month color change and water sorption of 9 new-generation flowable composites in 6 staining solutions.

    Science.gov (United States)

    Arregui, Maria; Giner, Luis; Ferrari, Marco; Vallés, Marta; Mercadé, Montserrat

    2016-11-28

    Color match and water sorption are two factors that affect restorative materials. Discoloration is essential in the lifespan of restorations. The aim of this study was to evaluate color change and water sorption of nine flowable composites at multiple time points over 6 months. 60 samples of each composite were divided into two groups (Color Change and Water Sorption/Solubility). Each Color Change group was divided into six subgroups, which were immersed in distilled water (DW), coffee (CF), Coca-Cola (CC), red wine (RW), tea (TE) and orange juice (OJ). The color was measured at the baseline, 1, 2, 3 and 4 weeks, and 3 and 6 months and color change values (ΔE) were calculated. Each Water Sorption [WS]/Solubility [WL] group was tested according to ISO 4049:2009. The data were evaluated using two-way ANOVA, Fisher's post-hoc test and Pearson's correlation test. The composite with the lowest ΔE differed for each solution: Filtek™ Bulk Fill in DW (∆E = 0.73 (0.17-1.759)); Vertise Flow in CF (∆E = 14.75 (7.91-27.41)), in TE (∆E = 7.27 (2.81-24.81)) and OJ (∆E = 3.17 (0.87-9.92)); Tetric EvoFlow® in CC (∆E = 1.27 (0.45-4.02)); and Filtek™ Supreme XTE in RW (∆E = 8.88 (5.23-19.59)). RW caused the most discoloration (∆E = 23.62 (4.93-51.36)). Vertise Flow showed the highest water sorption (WS = 69.10 ± 7.19). The Pearson test showed statistically significant positive correlations between water sorption and solubility and between water sorption and ∆E; the positive solubility-∆E correlation was not statistically significant. The findings suggest that water sorption is one factor associated with the ability of composites to discolor; however, discoloration is a multifactorial problem.

  8. Physical and chemical stability of pemetrexed in infusion solutions.

    Science.gov (United States)

    Zhang, Yanping; Trissel, Lawrence A

    2006-06-01

    Pemetrexed is a multitargeted, antifolate, antineoplastic agent that is indicated for single-agent use in locally advanced or metastatic non-small-cell lung cancer after prior chemotherapy and in combination with cisplatin for the treatment of malignant pleural mesothelioma not treatable by surgery. Currently, there is no information on the long-term stability of pemetrexed beyond 24 hours. To evaluate the longer-term physical and chemical stability of pemetrexed 2, 10, and 20 mg/mL in polyvinyl chloride (PVC) bags of dextrose 5% injection and NaCl 0.9% injection. Triplicate samples of pemetrexed were prepared in the concentrations and infusion solutions required. Evaluations for physical and chemical stability were performed initially and over 2 days at 23 degrees C protected from light and exposed to fluorescent light, and over 31 days of storage at 4 degrees C protected from light. Physical stability was assessed using turbidimetric and particulate measurement as well as visual observation. Chemical stability was evaluated by HPLC. All pemetrexed solutions remained chemically stable, with little or no loss of pemetrexed over 2 days at 23 degrees C, protected from light and exposed to fluorescent light, and over 31 days of storage at 4 degrees C, protected from light. The room temperature samples were physically stable throughout the 48 hour test period. However, pemetrexed admixtures developed large numbers of microparticulates during refrigerated storage exceeding 24 hours. Pemetrexed is chemically stable for 2 days at room temperature and 31 days refrigerated in dextrose 5% injection and NaCl 0.9% injection. However, substantial numbers of microparticulates may form in pemetrexed diluted in the infusion solutions in PVC bags, especially during longer periods of refrigerated storage. Limiting the refrigerated storage period to the manufacturer-recommended 24 hours will limit particulate formation.

  9. Radiation-chemical degradation of chloroform in water solutions

    International Nuclear Information System (INIS)

    Ahmadov, S.A; Gurbanov, M.A; Iskenderova, Z.I; Abdullaev, E.T; Ibadov, N.A.

    2006-01-01

    Full text: Chloroform is the major chlorine-containing compound forming at chlorination of drinking water. As our basic water resources of Kur and Araz rivers are mostly polluted along the territory of the neighbor republics their chlorination for the purpose of biological purification can result in forming of chloroform. Unfortunately, there are only poor data about containing of chloroform in drinking water in the Republic, however the particular problem is to develop new methods of drinking water purification from chloroform, taking into account the high toxicity of this compounds. Appropriate works indicate that radiation-chemical processing can mostly reduce the concentration of chloroform in drinking water. The purification degree can achieve 95-98%. This work studies the tendency of chloroform decomposition at its radiolysis processes in percentage. Taking into account the dissolvability of chloroform in water solutions it can be said that examined water solutions are homogeneous. Following advancements are studied: b Determination of radiation-chemical yield of chloroform decomposition at its various initial concentrations;Impact of adsorbed dose on pH of solutions;Formation of by-products.It is set that radiation-chemical output of chloroform decomposition is equal to 3.10-3-125 mol 100ev.

  10. Efficacy of 1.5% Dish Washing Solution and 95% Lemon Water in Substituting Perilous Xylene as a Deparaffinizing Agent for Routine H and E Staining Procedure: A Short Study

    Directory of Open Access Journals (Sweden)

    Anuradha Ananthaneni

    2014-01-01

    Full Text Available Aim. To assess the efficacy of dish washing solution and diluted lemon water in deparaffinizing sections during conventional hematoxylin and eosin staining technique. Objective. The objective is to utilize eco-friendly economical substitute for xylene. Materials and Methods. Using twenty paraffin embedded tissue blocks, three sections each were prepared. One section was stained with conventional H and E method (Group A and the other two sections with xylene-free (XF H and E (Groups B and C. Staining characteristics were compared with xylene and scoring was given. Total score of 3–5 was regarded as adequate for diagnosis and less than that inadequate for diagnosis. Statistical Analysis. Chi-square test, Kruskal Wallis ANOVA test, and Mann-Whitney U test were used. Results. Adequacy of nuclear staining, crispness, and staining for diagnosis were greater in both Groups A and C (100% than Group B (95%. Adequacy of cytoplasmic staining was similar in all the three groups (100%. Group B showed comparatively superior uniform staining and less retention of wax. Conclusion. Dish washing solution or diluted lemon water can be replaced for xylene as deparaffinizing agent in hematoxylin and eosin procedure.

  11. Chemical solution deposition: a path towards low cost coated conductors

    International Nuclear Information System (INIS)

    Obradors, X; Puig, T; Pomar, A; Sandiumenge, F; Pinol, S; Mestres, N; Castano, O; Coll, M; Cavallaro, A; Palau, A; Gazquez, J; Gonzalez, J C; Gutierrez, J; Roma, N; Ricart, S; Moreto, J M; Rossell, M D; Tendeloo, G van

    2004-01-01

    The achievement of low cost deposition techniques for high critical current YBa 2 Cu 3 O 7 coated conductors is one of the major objectives to achieve a widespread use of superconductivity in power applications. Chemical solution deposition techniques are appearing as a very promising methodology to achieve epitaxial oxide thin films at a low cost, so an intense effort is being carried out to develop routes for all chemical coated conductor tapes. In this work recent achievements will be presented towards the goal of combining the deposition of different type of buffer layers on metallic substrates based on metal-organic decomposition with the growth of YBa 2 Cu 3 O 7 layers using the trifluoroacetate route. The influence of processing parameters on the microstructure and superconducting properties will be stressed. High critical currents are demonstrated in 'all chemical' multilayers

  12. Delay chemical master equation: direct and closed-form solutions.

    Science.gov (United States)

    Leier, Andre; Marquez-Lago, Tatiana T

    2015-07-08

    The stochastic simulation algorithm (SSA) describes the time evolution of a discrete nonlinear Markov process. This stochastic process has a probability density function that is the solution of a differential equation, commonly known as the chemical master equation (CME) or forward-Kolmogorov equation. In the same way that the CME gives rise to the SSA, and trajectories of the latter are exact with respect to the former, trajectories obtained from a delay SSA are exact representations of the underlying delay CME (DCME). However, in contrast to the CME, no closed-form solutions have so far been derived for any kind of DCME. In this paper, we describe for the first time direct and closed solutions of the DCME for simple reaction schemes, such as a single-delayed unimolecular reaction as well as chemical reactions for transcription and translation with delayed mRNA maturation. We also discuss the conditions that have to be met such that such solutions can be derived.

  13. Chemical and Physical Methods to Analyze a Multicomponent Traditional Chinese Herbal Prescription Using LC-MS/MS, Electron Microscope, and Congo Red Staining

    Directory of Open Access Journals (Sweden)

    Chia-Ming Lu

    2013-01-01

    Full Text Available This study develops several chemical and physical methods to evaluate the quality of a traditional Chinese formulation, Jia-Wei-Xiao-Yao-San. Liquid chromatography-tandem mass spectrometry (LC-MS/MS coupled with electrospray ionization was used to measure the herbal biomarkers of saikosaponin A, saikosaponin D, ferulic acid, and paeoniflorin from this herbal formula. A scanning electron microscope (SEM and light microscopy photographs with Congo red staining were used to identify the cellulose fibers if raw herbal powder had been added to the herbal pharmaceutical product. Moreover, water solubility and crude fiber content examination were used to inspect for potential herbal additives to the herbal pharmaceutical products. The results demonstrate that the contents of the herbal ingredients of saikosaponin A, saikosaponin D, ferulic acid, and paeoniflorin were around 0.351 ± 0.017, 0.136 ± 0.010, 0.140 ± 0.005, and 2.281 ± 0.406 mg/g, respectively, for this herbal pharmaceutical product. The physical examination data demonstrate that the raw herbal powder had rough, irregular, lumpy, filamentous, and elongated shapes, as well as strong Congo red staining. In addition, water solubility and crude fiber content were not consistent in the herbal pharmaceutical products.

  14. Evaluation of the capacity of Raman Microscopy in the mineralogical and physico-chemical characterization of archaeological material: corroded metals, stained-glass and pigments

    International Nuclear Information System (INIS)

    Bouchard-Abouchacra, Michel

    2001-01-01

    This study is based on the evaluation of the capacity of non-destructive physico-chemical analysis by Raman Microscopy in three artistic and archaeological domains: metal corrosion, stained-glass and Prehistoric pigments. The study presents different levels of results depending on the field of application. In relation to Prehistoric pigments the results show clearly the capacity of distinguishing in black pigments, manganese oxide from amorphous carbon, or, the facility of identification of hematite in red pigments. Concerning the study of the corrosion products of metals, RM is indubitably an ideal technique for the identification and differentiation of the diverse alteration products observed on archaeological metallic material (sulphates, chlorides, oxides...). Finally, in the case of stained-glass, the positive results obtained in the study of the glass itself or in the study of the superficial coloration is counterbalanced by the complexity of identification of glass coloration due to metallic colloid particles, or by the fluorescent problem particularly important in this last application. However, the global result is clearly optimistic and demonstrate the utility of such a non-destructive technique for archaeologists, restorers or conservators. (author) [fr

  15. A comparison of chemical reference materials for solution calorimeters.

    Science.gov (United States)

    Ramos, Rita; Gaisford, Simon; Buckton, Graham; Royall, Paul G; Yff, Barbara T S; O'Neill, Michael A A

    2005-08-11

    Solution calorimeters are based on semi-adiabatic or isothermal heat-conduction principles and differ in the way they record data. They also have different measuring sensitivities and require different quantities of solute and solvent. As such, the choice of chemical test substance is not straightforward. Usually the dilution of KCl is recommended; it is possible to purchase a reference sample of KCl that has a certified enthalpy of solution and this standard material is usually used to test semi-adiabatic instruments. Here, we review the suitability of a range of chemical test substances (KCl, sucrose and Tris) for an isothermal heat-conduction solution calorimeter. It was found that KCl was not the best test material because its relatively high enthalpy of solution (DeltasolH) necessitated the use of small samples (2 mg), resulting in a relatively large standard deviation (sigman-1) in the values recorded (DeltasolH=17.14+/-0.49 kJ mol-1); furthermore, KCl data must be corrected to account for the effect of dilution, although the correction was found to be small (0.07 kJ mol-1) under the experimental conditions employed here. Sucrose appears to be a much more robust test material for isothermal heat-conduction instruments because its lower enthalpy of solution allows the use of much larger samples (20 mg), which minimises experimental errors. The DeltasolH value returned (6.14+/-0.08 kJ mol-1) is in excellent agreement with the literature. It is also cheap, readily available and requires minimal preparation although its widespread use would require the preparation of a certified reference sample.

  16. Radiation-chemical degradation of chloroform in water solutions

    International Nuclear Information System (INIS)

    Ahmadov, S.A.; Gurbanov, M.A.; Iskenderova, Z.I.; Abdullayev, E.T.; Ibadov, N.A.

    2006-01-01

    Full text: Chloroform is the major chlorine-containing compound forming at chlorination of drinking water. As our basic water resources of Kur and Araz rivers are mostly polluted along the territory of the neighbour republics their chlorination for the purpose of biological purification can result in forming of chloroform. Unfortunately, there are only poor data about containing of chloroform in drinking water in the Republic, however the particular problem is to develop new methods of drinking water purification from chloroform, taking into account the high toxicity of this compounds. Appropriate works indicate that radiation-chemical processing can mostly reduce the concentration of chloroform in drinking water. The purification degree can achieve 95-98 percent. This work studies the tendency of chloroform decomposition at its radiolysis processes in water solutions. The concentration of chloroform changed in the range of 0,03-1 weight percentage. Taking into account the dissolvability of chloroform in water solutions it can be said that examined water solutions are homogeneous. Following advancements are studied: 1) Determination of radiation-chemical yield of chloroform decomposition at its various initial concentrations; 2) Impact of adsorbed dose on pH of solutions; 3) Formation of by-products. It is set that radiation-chemical output of chloroform decomposition is equal to 3 * 10 - 3 - 125 mol/100 ev. The high yield of chloroform decomposition can be connected with the chain process of oxidation with presence of dissolved oxygen. However, taking into account the fact that at its water radiolysis the yield of active particles of OH, e - aq, H-atoms does not exceed 6-7 particles/100 ev, the observed high yield can be explained only with the chain process with presence of dissolved oxygen

  17. Chemical behaviour of plutonium in aqueous chloride solutions

    International Nuclear Information System (INIS)

    Bueppelmann, K.; Kim, J.I.

    1988-06-01

    The chemical behaviour of Plutonium has been investigated in concentrated NaCl solutions in the neutral pH range. The α-radiation induced radiolysis reactions oxidize the Cl - -ion to Cl 2 , HClO, ClO - and other species, which produce a strongly oxidizing medium. Under these conditions the Pu ions of lower oxidation states are readily oxidized to Pu(VI), which then undergo depending on the pH of the solution, various chemical reactions to produce PuO 2 Cl n , PuO 2 (ClO) m or PuO 2 (OH) x species. In addition to primary radiolysis reactions taking place in NaCl solutions, the reactions leading to the PuO 2 (Cl) n and PuO 2 (ClO) m species have been characterized and quantified systematically by spectroscopic and thermodynamic evaluation. The redox and complexation reactions of Pu ions under varying NaCl concentration, specific α-activity and pH are discussed. (orig.) [de

  18. Zn(II)-cyclam based chromogenic sensors for recognition of ATP in aqueous solution under physiological conditions and their application as viable staining agents for microorganism.

    Science.gov (United States)

    Mahato, Prasenjit; Ghosh, Amrita; Mishra, Sanjiv K; Shrivastav, Anupama; Mishra, Sandhya; Das, Amitava

    2011-05-02

    Two chromogenic complexes, L.Zn (where L is (E)-4-((4-(1,4,8,11-tetraazacyclotetradecan-1-ylsulfonyl)phenyl)diazenyl)-N,N-dimethylaniline) and its [2]pseudorotaxane form (α-CD.L.Zn), were found to bind preferentially to adenosine triphosphate (ATP), among all other common anions and biologically important phosphate (AMP, ADP, pyrophosphate, and phosphate) ions in aqueous HEPES buffer medium of pH 7.2. Studies with live cell cultures of prokaryotic microbes revealed that binding of these two reagents to intercellular ATP, produced in situ, could be used in delineating the gram-positive and the gram-negative bacteria. More importantly, these dyes were found to be nontoxic to living microbes (eukaryotes and prokaryotes) and could be used for studying the cell growth dynamics. Binding to these two viable staining agents to intercellular ATP was also confirmed by spectroscopic studies on cell growth in the presence of different respiratory inhibitors that influence the intercellular ATP generation. © 2011 American Chemical Society

  19. Exact solutions for chemical bond orientations from residual dipolar couplings

    International Nuclear Information System (INIS)

    Wedemeyer, William J.; Rohl, Carol A.; Scheraga, Harold A.

    2002-01-01

    New methods for determining chemical structures from residual dipolar couplings are presented. The fundamental dipolar coupling equation is converted to an elliptical equation in the principal alignment frame. This elliptical equation is then combined with other angular or dipolar coupling constraints to form simple polynomial equations that define discrete solutions for the unit vector(s). The methods are illustrated with residual dipolar coupling data on ubiquitin taken in a single anisotropic medium. The protein backbone is divided into its rigid groups (namely, its peptide planes and C α frames), which may be solved for independently. A simple procedure for recombining these independent solutions results in backbone dihedral angles φ and ψ that resemble those of the known native structure. Subsequent refinement of these φ-ψ angles by the ROSETTA program produces a structure of ubiquitin that agrees with the known native structure to 1.1 A C α rmsd

  20. Differential staining of bacteria: gram stain.

    Science.gov (United States)

    Moyes, Rita B; Reynolds, Jackie; Breakwell, Donald P

    2009-11-01

    In 1884, Hans Christian Gram, a Danish doctor, developed a differential staining technique that is still the cornerstone of bacterial identification and taxonomic division. This multistep, sequential staining protocol separates bacteria into four groups based on cell morphology and cell wall structure: Gram-positive cocci, Gram-negative cocci, Gram-positive rods, and Gram-negative rods. The Gram stain is useful for assessing bacterial contamination of tissue culture samples or for examining the Gram stain status and morphological features of bacteria isolated from mixed or isolated bacterial cultures. (c) 2009 by John Wiley & Sons, Inc.

  1. Solution-gated graphene transistors for chemical and biological sensors.

    Science.gov (United States)

    Yan, Feng; Zhang, Meng; Li, Jinhua

    2014-03-01

    Graphene has attracted much attention in biomedical applications for its fascinating properties. Because of the well-known 2D structure, every atom of graphene is exposed to the environment, so the electronic properties of graphene are very sensitive to charged analytes (ions, DNA, cells, etc.) or an electric field around it, which renders graphene an ideal material for high-performance sensors. Solution-gated graphene transistors (SGGTs) can operate in electrolytes and are thus excellent candidates for chemical and biological sensors, which have been extensively studied in the recent 5 years. Here, the device physics, the sensing mechanisms, and the performance of the recently developed SGGT-based chemical and biological sensors, including pH, ion, cell, bacterial, DNA, protein, glucose sensors, etc., are introduced. Their advantages and shortcomings, in comparison with some conventional techniques, are discussed. Conclusions and challenges for the future development of the field are addressed in the end. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Chemical metallization of KMPR photoresist polymer in aqueous solutions

    Energy Technology Data Exchange (ETDEWEB)

    Zeb, Gul [MiQro Innovation Collaborative Centre (C2MI), 45, boul. de l' Aéroport, Bromont, QC, J2L 1S8 (Canada); Mining & Materials Engineering, McGill University, 3610,University Street, Montreal, QC, H3A 0C5 (Canada); Duong, Xuan Truong [Department of Mechanical Engineering, Ecole polytechnique de Montréal, Montréal, QC, H3C 3T5 (Canada); Thai Nguyen University of Technology, 3-2 Street, Thai Nguyen City (Viet Nam); Vu, Ngoc Pi; Phan, Quang The; Nguyen, Duc Tuong; Ly, Viet Anh [Thai Nguyen University of Technology, 3-2 Street, Thai Nguyen City (Viet Nam); Salimy, Siamak [ePeer Review LLC, 145 Pine Haven Shores Rd, Suite 1000-X, Shelburne, VT 05482 (United States); Le, Xuan Tuan, E-mail: xuantuan.le@teledyne.com [MiQro Innovation Collaborative Centre (C2MI), 45, boul. de l' Aéroport, Bromont, QC, J2L 1S8 (Canada); Thai Nguyen University of Technology, 3-2 Street, Thai Nguyen City (Viet Nam)

    2017-06-15

    Highlights: • Electroless deposition of Ni-B film on KMPR photoresist polymer insulator with excellent adhesion has been achieved. • This metallization has been carried out in aqueous solutions at low temperature. • Polyamine palladium complexes grafts serve as seeds for the electroless plating on KMPR. • This electroless metallization process is simple, industrially feasible, chromium-free and environment-friendly. - Abstract: While conventional methods for preparing thin films of metals and metallic alloys on insulating substrates in the field of microelectromechanical systems (MEMS) include vapor deposition techniques, we demonstrate here that electroless deposition can be considered as an alternate efficient approach to metallize the surface of insulating substrates, such as KMPR epoxy photoresist polymer. In comparison with the physical and chemical vapor deposition methods, which are well-established for metallization of photoresist polymers, our electroless nickel plating requires only immersing the substrates into aqueous solutions in open air at low temperatures. Thin films of nickel alloy have been deposited electrolessly on KMPR surface, through a cost-effective and environmental chromium-free process, mediated through direct grafting of amine palladium complexes in aqueous medium. This covalent organic coating provides excellent adhesion between KMPR and the nickel film and allows better control of the palladium catalyst content. Covalent grafting and characterization of the deposited nickel film have been carried out by means of Fourier-transform infrared spectroscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy techniques.

  3. Chemical dosimetry by UV spectrophotometry of aqueous ascorbic acid solutions

    International Nuclear Information System (INIS)

    Alian, A.; El-Assay, N.B.; Abdel-Rehim, F.; Amin, N.E.; McLaughlin, W.L.; Roushdy, H.

    1984-01-01

    The decrease in the ultraviolet absorption of aqueous solutions of ascorbic acid brought about by large doses of gamma radiation has been investigated as a means of developing a new chemical dosimeter. Because of spontaneous ring opening under various conditions after dissolution in water, some additives were examined as possible stabilizers against such denaturing of aqueous ascorbic acid. At an ascorbic acid concentration of 10 -4 M, either 1 to 2% glycine or 0.2 M NaCl was found to be a good stabilizer. A mechanism of radiation chemistry has been proposed based on hydroxyl radical and hydroxyl adduct intermediates, leading to dehydroascorbic acid through the ascorbate complex. The optimum dosimeter solution covers an absorbed dose range approx. 50 to 350 Gy, when measured at 264 nm wavelength. The G-values for dehydroascorbic acid production were determined to be 2.94 +- 0.33 and 2.43 +- 0.11 (100 eV) -1 , with glycine and NaCl used respectively as stabilizers. (author)

  4. Port-Wine Stains

    Science.gov (United States)

    ... Safe Videos for Educators Search English Español Port-Wine Stains KidsHealth / For Parents / Port-Wine Stains What's ... Manchas de vino de oporto What Are Port-Wine Stains? A port-wine stain is a type ...

  5. Application of an immunoperoxidase staining method for detection of 7,8-dihydro-8-oxodeoxyguanosine as a biomarker of chemical-induced oxidative stress in marine organisms

    International Nuclear Information System (INIS)

    Machella, Nicola; Regoli, Francesco; Cambria, Antonio; Santella, Regina M.

    2004-01-01

    7,8-Dihydro-8-oxodeoxyguanosine (8-oxo-dG) is a typical modification of DNA caused by oxygen free radicals and can be an useful biomarker for pollutants inducing oxidative stress. An immunoperoxidase method using monoclonal antibody 1F7 toward 8-oxo-dG was applied to tissues and smeared cells of marine organisms for detection and quantification of oxidative DNA damage in such models. The assay, previously employed on human cells, was assessed for the first time on Mediterranean mussels (Mytilus galloprovincialis) and European eels (Anguilla anguilla), exposed to model pro-oxidant chemicals, namely benzo[a]pyrene (B[a]P) and copper. Quantification of 8-oxo-dG was microscopically carried out and expressed as relative nuclear staining intensity. Higher levels of oxidative DNA damage were detected in the digestive glands of treated mussels compared to controls, while the effect was less pronounced in haemocytes, characterized by more elevated basal levels of 8-oxo-dG. The assay was suitable for detection of 8-oxo-dG also in fish liver sections indicating consistent damage after B[a]P exposure. The main advantage of the immunohistochemical approach is the elimination of DNA extraction which considerably reduces the processing of biological samples. In addition, the assay requires small amounts of frozen tissues or fixed cells for detection of 8-oxo-dG and is potentially able to discriminate variable susceptibility to oxidative stress in different cell types. Although further investigations are required for the improvement and the validation of the assay in field conditions, laboratory exposures provided useful indications on the consistency of the approach and the efficacy of antibody 1F7 in marine organisms for a rapid assessment of pollutant-induced oxidative DNA damage

  6. Chemical metallization of KMPR photoresist polymer in aqueous solutions

    Science.gov (United States)

    Zeb, Gul; Duong, Xuan Truong; Vu, Ngoc Pi; Phan, Quang The; Nguyen, Duc Tuong; Ly, Viet Anh; Salimy, Siamak; Le, Xuan Tuan

    2017-06-01

    While conventional methods for preparing thin films of metals and metallic alloys on insulating substrates in the field of microelectromechanical systems (MEMS) include vapor deposition techniques, we demonstrate here that electroless deposition can be considered as an alternate efficient approach to metallize the surface of insulating substrates, such as KMPR epoxy photoresist polymer. In comparison with the physical and chemical vapor deposition methods, which are well-established for metallization of photoresist polymers, our electroless nickel plating requires only immersing the substrates into aqueous solutions in open air at low temperatures. Thin films of nickel alloy have been deposited electrolessly on KMPR surface, through a cost-effective and environmental chromium-free process, mediated through direct grafting of amine palladium complexes in aqueous medium. This covalent organic coating provides excellent adhesion between KMPR and the nickel film and allows better control of the palladium catalyst content. Covalent grafting and characterization of the deposited nickel film have been carried out by means of Fourier-transform infrared spectroscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy techniques.

  7. Short Nissl staining for incubated cryostat sections of the brain.

    Science.gov (United States)

    Lindroos, O F

    1991-01-01

    Nissl stain often binds poorly to cryostat sections which have been incubated in solutions of radiolabeled ligands. Such incubation is used in receptor autoradiography of the brain when using the in vitro method. We have developed a rapid (16 min) modification of Nissl staining for sections that bind stain poorly, e.g., incubated sections. The method stains well sections which cannot be stained with other rapid Nissl staining methods.

  8. Chemical solution route to self-assembled epitaxial oxide nanostructures.

    Science.gov (United States)

    Obradors, X; Puig, T; Gibert, M; Queraltó, A; Zabaleta, J; Mestres, N

    2014-04-07

    Self-assembly of oxides as a bottom-up approach to functional nanostructures goes beyond the conventional nanostructure formation based on lithographic techniques. Particularly, chemical solution deposition (CSD) is an ex situ growth approach very promising for high throughput nanofabrication at low cost. Whereas strain engineering as a strategy to define nanostructures with tight control of size, shape and orientation has been widely used in metals and semiconductors, it has been rarely explored in the emergent field of functional complex oxides. Here we will show that thermodynamic modeling can be very useful to understand the principles controlling the growth of oxide nanostructures by CSD, and some attractive kinetic features will also be presented. The methodology of strain engineering is applied in a high degree of detail to form different sorts of nanostructures (nanodots, nanowires) of the oxide CeO2 with fluorite structure which then is used as a model system to identify the principles controlling self-assembly and self-organization in CSD grown oxides. We also present, more briefly, the application of these ideas to other oxides such as manganites or BaZrO3. We will show that the nucleation and growth steps are essentially understood and manipulated while the kinetic phenomena underlying the evolution of the self-organized networks are still less widely explored, even if very appealing effects have been already observed. Overall, our investigation based on a CSD approach has opened a new strategy towards a general use of self-assembly and self-organization which can now be widely spread to many functional oxide materials.

  9. Solutions of the chemical kinetic equations for initially inhomogeneous mixtures.

    Science.gov (United States)

    Hilst, G. R.

    1973-01-01

    Following the recent discussions by O'Brien (1971) and Donaldson and Hilst (1972) of the effects of inhomogeneous mixing and turbulent diffusion on simple chemical reaction rates, the present report provides a more extensive analysis of when inhomogeneous mixing has a significant effect on chemical reaction rates. The analysis is then extended to the development of an approximate chemical sub-model which provides much improved predictions of chemical reaction rates over a wide range of inhomogeneities and pathological distributions of the concentrations of the reacting chemical species. In particular, the development of an approximate representation of the third-order correlations of the joint concentration fluctuations permits closure of the chemical sub-model at the level of the second-order moments of these fluctuations and the mean concentrations.

  10. Method for Non-Invasive Determination of Chemical Properties of Aqueous Solutions

    Science.gov (United States)

    Todd, Paul W. (Inventor); Jones, Alan (Inventor); Thomas, Nathan A. (Inventor)

    2016-01-01

    A method for non-invasively determining a chemical property of an aqueous solution is provided. The method provides the steps of providing a colored solute having a light absorbance spectrum and transmitting light through the colored solute at two different wavelengths. The method further provides the steps of measuring light absorbance of the colored solute at the two different transmitted light wavelengths, and comparing the light absorbance of the colored solute at the two different wavelengths to determine a chemical property of an aqueous solution.

  11. Equilibrium Constant as Solution to the Open Chemical Systems

    OpenAIRE

    Zilbergleyt, B.

    2008-01-01

    According to contemporary views, equilibrium constant is relevant only to true thermodynamic equilibria in isolated systems with one chemical reaction. The paper presents a novel formula that ties-up equilibrium constant and chemical system composition at any state, isolated or open as well. Extending the logarithmic logistic map of the Discrete Thermodynamics of Chemical Equilibria, this formula maps the system population at isolated equilibrium into the population at any open equilibrium at...

  12. Chemical milling solution reveals stress corrosion cracks in titanium alloy

    Science.gov (United States)

    Braski, D. N.

    1967-01-01

    Solution of hydrogen flouride, hydrogen peroxide, and water reveals hot salt stress corrosion cracks in various titanium alloys. After the surface is rinsed in water, dried, and swabbed with the solution, it can be observed by the naked eye or at low magnification.

  13. Effect of textural and chemical characteristics of activated carbons on phenol adsorption in aqueous solutions

    OpenAIRE

    Vargas Diana P.; Giraldo Liliana; Moreno-Piraján Juan Carlos

    2017-01-01

    The effect of textural and chemical properties such as: surface area, pore volume and chemical groups content of the granular activated carbon and monoliths on phenol adsorption in aqueous solutions was studied. Granular activated carbon and monolith samples were produced by chemical activation. They were characterized by using N2 adsorption at 77 K, CO2 adsorption at 273 K, Boehm Titrations and immersion calorimetry in phenol solutions. Microporous materials with different pore size distribu...

  14. Detecting Chemical Weapons: Threats, Requirements, Solutions, and Future Challenges

    Science.gov (United States)

    Boso, Brian

    2011-03-01

    Although chemicals have been reportedly used as weapons for thousands of years, it was not until 1915 at Ypres, France that an industrial chemical, chlorine, was used in World War I as an offensive weapon in significant quantity, causing mass casualties. From that point until today the development, detection, production and protection from chemical weapons has be an organized endeavor of many of the world's armed forces and in more recent times, non-governmental terrorist organizations. The number of Chemical Warfare Agents (CWAs) has steadily increased as research into more toxic substances continued for most of the 20 th century. Today there are over 70 substances including harassing agents like tear gas, incapacitating agents, and lethal agents like blister, blood, chocking, and nerve agents. The requirements for detecting chemical weapons vary depending on the context in which they are encountered and the concept of operation of the organization deploying the detection equipment. The US DoD, for example, has as a requirement, that US forces be able to continue their mission, even in the event of a chemical attack. This places stringent requirements on detection equipment. It must be lightweight (developed for this application, including, but not limited to: mass spectroscopy, IR spectroscopy, RAMAN spectroscopy, MEMs micro-cantilever sensors, surface acoustic wave sensors, differential mobility spectrometry, and amplifying fluorescence polymers. In the future the requirements for detection equipment will continue to become even more stringent. The continuing increase in the sheer number of threats that will need to be detected, the development of binary agents requiring that even the precursor chemicals be detected, the development of new types of agents unlike any of the current chemistries, and the expansion of the list of toxic industrial chemical will require new techniques with higher specificity and more sensitivity.

  15. Radiation-chemical oxidation of neptunium in perchloric acid solutions

    International Nuclear Information System (INIS)

    Shilov, V.P.; Gusev, Yu.K.; Pikaev, A.K.; Stepanova, E.S.; Krot, N.N.

    1979-01-01

    The γ-radiation effect (at a dose rate of 5x10 16 eV/mlxs) on 1x10 -3 Np(6) and Np(5) perchloric acid solutions is studied. The output of Np(6) loss in aerated 0.001-0.005M HClO 4 solutions was 2.4 ions/100 eV. The output of Np(5) loss in solutions saturated with nitrous oxide was 2.1 ions/100 eV at pH-4. In aerated 0.1-1.0 M HClO 4 solutions in presence of XeO 4 the output of Np(5) loss grows from 6.6 to 13.5 ions/100 eV as (XeO 3 ) 0 increases from 1x10 -3 to 2x10 -2 M. Possible process mechanisms have been proposed

  16. leaves extracts as counter stain in gram staining reaction 56

    African Journals Online (AJOL)

    DR. AMINU

    is a stain with color contrasting to the principal stain, making the stained ... technology today, the Gram's staining method remains ... was aimed at employing the use of Henna leaves extract as ... fragrant, white or rose flowers in clusters. It is.

  17. Nuclear staining with alum hematoxylin.

    Science.gov (United States)

    Llewellyn, B D

    2009-08-01

    The hematoxylin and eosin stain is the most common method used in anatomic pathology, yet it is a method about which technologists ask numerous questions. Hematoxylin is a natural dye obtained from a tree originally found in Central America, and is easily converted into the dye hematein. This dye forms coordination compounds with mordant metals, such as aluminum, and the resulting lake attaches to cell nuclei. Regressive formulations contain a higher concentration of dye than progressive formulations and may also contain a lower concentration of mordant. The presence of an acid increases the life of the solution and in progressive solutions may also affect selectivity of staining. An appendix lists more than 60 hemalum formulations and the ratio of dye to mordant for each.

  18. In-situ chemical analyses of trans-polyisoprene by histochemical staining and Fourier transform infrared microspectroscopy in a rubber-producing plant, Eucommia ulmoides Oliver.

    Science.gov (United States)

    Bamba, Takeshi; Fukusaki, Ei-Ichiro; Nakazawa, Yoshihisa; Kobayashi, Akio

    2002-10-01

    The localization of polyisoprene in young stem tissues of Eucommia ulmoides Oliver was investigated by histochemical staining and Fourier transform infrared (FT-IR) microspectroscopy. The fibrous structures were stained with Oil Red O. FT-IR microspectroscopic analysis proved that the fibrous structures were trans-polyisoprene. Granular structures stained with the dye, and characteristic absorptions at 2,960 cm(-1) and 1,430 cm(-1) in FT-IR suggested that trans-polyisoprene accumulated in the vicinity of the cambium layer. We have thus successfully shown for the first time the localization of trans-polyisoprene in plant tissues, and our histological investigation allowed us to presume the main sites of biosynthesis and accumulation of trans-rubber. Furthermore, a new technical approach, the preparation of sections using an electronic freezing unit and the in situ analysis of polyisoprene using FT-IR microspectroscopy, is demonstrated to be a promising method for determining the accumulation of polyisoprene as well as other metabolites.

  19. Differential staining of bacteria: acid fast stain.

    Science.gov (United States)

    Reynolds, Jackie; Moyes, Rita B; Breakwell, Donald P

    2009-11-01

    Acid-fastness is an uncommon characteristic shared by the genera Mycobacterium (Section 10A) and Nocardia. Because of this feature, this stain is extremely helpful in identification of these bacteria. Although Gram positive, acid-fast bacteria do not take the crystal violet into the wall well, appearing very light purple rather than the deep purple of normal Gram-positive bacteria. (c) 2009 by John Wiley & Sons, Inc.

  20. Computer Facilitated Mathematical Methods in Chemical Engineering--Similarity Solution

    Science.gov (United States)

    Subramanian, Venkat R.

    2006-01-01

    High-performance computers coupled with highly efficient numerical schemes and user-friendly software packages have helped instructors to teach numerical solutions and analysis of various nonlinear models more efficiently in the classroom. One of the main objectives of a model is to provide insight about the system of interest. Analytical…

  1. Histological Stains: A Literature Review and Case Study.

    Science.gov (United States)

    Alturkistani, Hani A; Tashkandi, Faris M; Mohammedsaleh, Zuhair M

    2015-06-25

    The history of histology indicates that there have been significant changes in the techniques used for histological staining through chemical, molecular biology assays and immunological techniques, collectively referred to as histochemistry. Early histologists used the readily available chemicals to prepare tissues for microscopic studies; these laboratory chemicals were potassium dichromate, alcohol and the mercuric chloride to harden cellular tissues. Staining techniques used were carmine, silver nitrate, Giemsa, Trichrome Stains, Gram Stain and Hematoxylin among others. The purpose of this research was to assess past and current literature reviews, as well as case studies, with the aim of informing ways in which histological stains have been improved in the modern age. Results from the literature review has indicated that there has been an improvement in histopathology and histotechnology in stains used. There has been a rising need for efficient, accurate and less complex staining procedures. Many stain procedures are still in use today, and many others have been replaced with new immunostaining, molecular, non-culture and other advanced staining techniques. Some staining methods have been abandoned because the chemicals required have been medically proven to be toxic. The case studies indicated that in modern histology a combination of different stain techniques are used to enhance the effectiveness of the staining process. Currently, improved histological stains, have been modified and combined with other stains to improve their effectiveness.

  2. Chemical hazards from decontamination solutions in low level waste

    International Nuclear Information System (INIS)

    Leventhal, L.; Miller, A.; Turney, J.; Naughton, M.; IMPELL Corp., Walnut Creek, CA; Electric Power Research Inst., Palo Alto, CA)

    1985-01-01

    Recent regulations are focussing more attention on the non-radioactive matrix materials associated with radioactive wastes. Decontamination of operating facilities is becoming a more significant source of low-level waste. This study reviewed the chemical and biological hazards of over 50 decontamination processes. Seventeen of the most prominent hard and soft decontamination processes were examined in detail. The chemical and biological hazards of these seventeen are presented in this paper. These hazards influence the choice of radwaste processing and packaging operations and methods. Federal, state and local regulations further impact on operations and waste disposal. Hazards to personnel, in plant and off-site, resulting from the decontamination cycle are evaluated. 1 fig., 5 tabs

  3. An expanded conceptual framework for solution-focused management of chemical pollution in European waters

    NARCIS (Netherlands)

    Munthe, John; Brorström-Lundén, Eva; Rahmberg, Magnus; Posthuma, Leo; Altenburger, Rolf; Brack, Werner; Bunke, Dirk; Engelen, Guy; Gawlik, Bernd Manfred; van Gils, Jos; Herráez, David López; Rydberg, Tomas; Slobodnik, Jaroslav; van Wezel, Annemarie

    2017-01-01

    Background: This paper describes a conceptual framework for solutions-focused management of chemical contaminants built on novel and systematic approaches for identifying, quantifying and reducing risks of these substances. Methods: The conceptual framework was developed in interaction with

  4. Chemical treatment of ammonium fluoride solution in uranium reconversion plant

    International Nuclear Information System (INIS)

    Carvalho Frajndlich, E.U. de.

    1992-01-01

    A chemical procedure is described for the treatment of the filtrate, produced from the transformation of uranium hexafluoride (U F 6 ) into ammonium uranyl carbonate (AUC). This filtrate is an intermediate product in the U F 6 to uranium dioxide (U O 2 ) reconversion process. The described procedure recovers uranium as ammonium peroxide fluoro uranate (APOFU) by precipitation with hydrogen peroxide (H 2 O 2 ), and as later step, its calcium fluoride (CaF 2 ) co-precipitation. The recovered uranium is recycled to the AUC production plant. (author)

  5. Determination of trace amounts of chemical warfare agent degradation products in decontamination solutions with NMR spectroscopy.

    Science.gov (United States)

    Koskela, Harri; Rapinoja, Marja-Leena; Kuitunen, Marja-Leena; Vanninen, Paula

    2007-12-01

    Decontamination solutions are used for an efficient detoxification of chemical warfare agents (CWAs). As these solutions can be composed of strong alkaline chemicals with hydrolyzing and oxidizing properties, the analysis of CWA degradation products in trace levels from these solutions imposes a challenge for any analytical technique. Here, we present results of application of nuclear magnetic resonance spectroscopy for analysis of trace amounts of CWA degradation products in several untreated decontamination solutions. Degradation products of the nerve agents sarin, soman, and VX were selectively monitored with substantially reduced interference of background signals by 1D 1H-31P heteronuclear single quantum coherence (HSQC) spectrometry. The detection limit of the chemicals was at the low part-per-million level (2-10 microg/mL) in all studied solutions. In addition, the concentration of the degradation products was obtained with sufficient confidence with external standards.

  6. Quantifying solute transport processes: are chemically "conservative" tracers electrically conservative?

    Science.gov (United States)

    Singha, Kamini; Li, Li; Day-Lewis, Frederick D.; Regberg, Aaron B.

    2012-01-01

    The concept of a nonreactive or conservative tracer, commonly invoked in investigations of solute transport, requires additional study in the context of electrical geophysical monitoring. Tracers that are commonly considered conservative may undergo reactive processes, such as ion exchange, thus changing the aqueous composition of the system. As a result, the measured electrical conductivity may reflect not only solute transport but also reactive processes. We have evaluated the impacts of ion exchange reactions, rate-limited mass transfer, and surface conduction on quantifying tracer mass, mean arrival time, and temporal variance in laboratory-scale column experiments. Numerical examples showed that (1) ion exchange can lead to resistivity-estimated tracer mass, velocity, and dispersivity that may be inaccurate; (2) mass transfer leads to an overestimate in the mobile tracer mass and an underestimate in velocity when using electrical methods; and (3) surface conductance does not notably affect estimated moments when high-concentration tracers are used, although this phenomenon may be important at low concentrations or in sediments with high and/or spatially variable cation-exchange capacity. In all cases, colocated groundwater concentration measurements are of high importance for interpreting geophysical data with respect to the controlling transport processes of interest.

  7. Fluctuation theory of solutions applications in chemistry, chemical engineering, and biophysics

    CERN Document Server

    Smith, Paul E

    2013-01-01

    There are essentially two theories of solutions that can be considered exact: the McMillan-Mayer theory and Fluctuation Solution Theory (FST). The first is mostly limited to solutes at low concentrations, while FST has no such issue. It is an exact theory that can be applied to any stable solution regardless of the number of components and their concentrations, and the types of molecules and their sizes. Fluctuation Theory of Solutions: Applications in Chemistry, Chemical Engineering, and Biophysics outlines the general concepts and theoretical basis of FST and provides a range of applications

  8. Chemical systems in aqueous solutions for using in the holographic ionizing radiation

    International Nuclear Information System (INIS)

    Nicolau-Rebigan, S.

    1979-01-01

    Some types of chemical systems in aqueous solutions for utilization as active media in holographic ionizing radiation dosimeter are presented. One discussed some advantages of the holographic dosimeter comparatively with another existing types. It is outlined the advantages of using aqueousss solutions as active media in holographic dosimeter. (author)

  9. Crystal chemical analysis of formation of solid solutions on the basis of compounds with garnet structure

    International Nuclear Information System (INIS)

    Kuz'micheva, G.M.; Kozlikin, S.N.

    1989-01-01

    Crystal chemical formulas permitting to evaluate the character of changes in interatomic distances during isomorphous substitution and, hence, the probability of formation of internal solid solutions and successive isomorphous substitution, are presented. The possibility of formation of introduction solid solutions is considered, using as an example Sc, Y oxides, rare earths with garnet structure

  10. State estimation of chemical engineering systems tending to multiple solutions

    Directory of Open Access Journals (Sweden)

    N. P. G. Salau

    2014-09-01

    Full Text Available A well-evaluated state covariance matrix avoids error propagation due to divergence issues and, thereby, it is crucial for a successful state estimator design. In this paper we investigate the performance of the state covariance matrices used in three unconstrained Extended Kalman Filter (EKF formulations and one constrained EKF formulation (CEKF. As benchmark case studies we have chosen: a a batch chemical reactor with reversible reactions whose system model and measurement are such that multiple states satisfy the equilibrium condition and b a CSTR with exothermic irreversible reactions and cooling jacket energy balance whose nonlinear behavior includes multiple steady-states and limit cycles. The results have shown that CEKF is in general the best choice of EKF formulations (even if they are constrained with an ad hoc clipping strategy which avoids undesired states for such case studies. Contrary to a clipped EKF formulation, CEKF incorporates constraints into an optimization problem, which minimizes the noise in a least square sense preventing a bad noise distribution. It is also shown that, although the Moving Horizon Estimation (MHE provides greater robustness to a poor guess of the initial state, converging in less steps to the actual states, it is not justified for our examples due to the high additional computational effort.

  11. Physical and chemical stability of proflavine contrast agent solutions for early detection of oral cancer.

    Science.gov (United States)

    Kawedia, Jitesh D; Zhang, Yan-Ping; Myers, Alan L; Richards-Kortum, Rebecca R; Kramer, Mark A; Gillenwater, Ann M; Culotta, Kirk S

    2016-02-01

    Proflavine hemisulfate solution is a fluorescence contrast agent to visualize cell nuclei using high-resolution optical imaging devices such as the high-resolution microendoscope. These devices provide real-time imaging to distinguish between normal versus neoplastic tissue. These images could be helpful for early screening of oral cancer and its precursors and to determine accurate margins of malignant tissue for ablative surgery. Extemporaneous preparation of proflavine solution for these diagnostic procedures requires preparation in batches and long-term storage to improve compounding efficiency in the pharmacy. However, there is a paucity of long-term stability data for proflavine contrast solutions. The physical and chemical stability of 0.01% (10 mg/100 ml) proflavine hemisulfate solutions prepared in sterile water was determined following storage at refrigeration (4-8℃) and room temperature (23℃). Concentrations of proflavine were measured at predetermined time points up to 12 months using a validated stability-indicating high-performance liquid chromatography method. Proflavine solutions stored under refrigeration were physically and chemically stable for at least 12 months with concentrations ranging from 95% to 105% compared to initial concentration. However, in solutions stored at room temperature increased turbidity and particulates were observed in some of the tested vials at 9 months and 12 months with peak particle count reaching 17-fold increase compared to baseline. Solutions stored at room temperature were chemically stable up to six months (94-105%). Proflavine solutions at concentration of 0.01% were chemically and physically stable for at least 12 months under refrigeration. The solution was chemically stable for six months when stored at room temperature. We recommend long-term storage of proflavine solutions under refrigeration prior to diagnostic procedure. © The Author(s) 2014.

  12. Crystal-chemical features of the solid solutions

    Energy Technology Data Exchange (ETDEWEB)

    Titov, V.V.; Kesler, Ya.A.; Gordeev, I.V.; Mozhaev, A.P.

    1988-04-01

    The unusual magnetic properties of the solid solutions of CuCr/sub 2/S/sub 4/ in Cu/sub 0.5/Mo/sub 0.5/Cr/sub 2/S/sub 4/ (M = Al, Ga, In) are closely related to the crystal chemistry of these compounds. Specimens for structural investigation were obtained by solid-phase synthesis in evacuated quartz capsules. X-ray phase analysis of all the compounds was made by the powder method in a DRON-1 diffractometer with Cu K..cap alpha.. filtered radiation. The experimental confirmation of the ordering of the cations in the tetrahedral sublattice of the investigated spinels was obtained by the authors from their IR absorption spectra taken in the range 400-33 cm/sup /minus/1/. The presence of seven intense absorption bands in the spectra of the specimens indicates that these materials belong to the space group F/anti/43m, i.e., that there is ordering in the A sublattice. Their investigation led them to the conclusion that in a number of cases the vibrational spectra of the crystals are more sensitive in the investigation of atomic ordering than the spectra of x-ray and neutron diffraction, in agreement with the theoretical predictions.

  13. A new chemical system solution for acid gas removal

    Energy Technology Data Exchange (ETDEWEB)

    Seiler, M.; Rolker, J.; Witthaut, D.; Schulze, S. [Evonik Industries AG, Hanau (Germany); Buchholz, S. [Evonik Industries AG, Marl (Germany)

    2012-07-01

    An energy-efficient absorbent formulation fors eparating acid gases (e.g. CO{sub 2}, H2S) from gas streams such as natural gas, syngas or flue gas is important for a number of industrial applications. In many cases, a substantial share of their costs is driven by the operational expenditure (OPEX) of the CO{sub 2} separation unit. One possible strategy for reducing OPEX is the improvement of the absorbent performance. Although a number of absorbents for the separation of CO{sub 2} from gas streams exist, there is still a need to develop CO{sub 2} absorbents with an improved absorption performance, less corrosion and foaming, no nitrosamine formation, lower energy requirement and therefore less OPEX. This contribution aims at giving a brief state-of-the-art overview followed by an introduction and performance characterization of a new family of amine-based CO{sub 2} absorbents. High cyclic capacities in the range of 2.9 to 3.2 mol CO{sub 2} kg{sup -1} absorbent and low absorption enthalpies of about -30 kJ mol{sup -1} allow for significant savings in the regeneration energy of the new absorbent system. Calculations with the modified Kremser model indicate a reduction in the specific reboiler heat duty of 45 %. Moreover, the high-performance absorbents developed show much lower corrosion rates than state-of-the-art solutions that are currently employed. (orig.)

  14. An expanded conceptual framework for solution-focused management of chemical pollution in European waters.

    Science.gov (United States)

    Munthe, John; Brorström-Lundén, Eva; Rahmberg, Magnus; Posthuma, Leo; Altenburger, Rolf; Brack, Werner; Bunke, Dirk; Engelen, Guy; Gawlik, Bernd Manfred; van Gils, Jos; Herráez, David López; Rydberg, Tomas; Slobodnik, Jaroslav; van Wezel, Annemarie

    2017-01-01

    This paper describes a conceptual framework for solutions-focused management of chemical contaminants built on novel and systematic approaches for identifying, quantifying and reducing risks of these substances. The conceptual framework was developed in interaction with stakeholders representing relevant authorities and organisations responsible for managing environmental quality of water bodies. Stakeholder needs were compiled via a survey and dialogue. The content of the conceptual framework was thereafter developed with inputs from relevant scientific disciplines. The conceptual framework consists of four access points: Chemicals, Environment, Abatement and Society, representing different aspects and approaches to engaging in the issue of chemical contamination of surface waters. It widens the scope for assessment and management of chemicals in comparison to a traditional (mostly) perchemical risk assessment approaches by including abatement- and societal approaches as optional solutions. The solution-focused approach implies an identification of abatement- and policy options upfront in the risk assessment process. The conceptual framework was designed for use in current and future chemical pollution assessments for the aquatic environment, including the specific challenges encountered in prioritising individual chemicals and mixtures, and is applicable for the development of approaches for safe chemical management in a broader sense. The four access points of the conceptual framework are interlinked by four key topics representing the main scientific challenges that need to be addressed, i.e.: identifying and prioritising hazardous chemicals at different scales; selecting relevant and efficient abatement options; providing regulatory support for chemicals management; predicting and prioritising future chemical risks. The conceptual framework aligns current challenges in the safe production and use of chemicals. The current state of knowledge and implementation

  15. New Grocott Stain without Using Chromic Acid

    International Nuclear Information System (INIS)

    Shiogama, Kazuya; Kitazawa, Kayo; Mizutani, Yasuyoshi; Onouchi, Takanori; Inada, Ken-ichi; Tsutsumi, Yutaka

    2015-01-01

    We established a new “ecological” Grocott stain for demonstrating fungi, based upon a 4R principle of refusal, reduction, reuse, and recycle of waste management. Conventional Grocott stain employs environmentally harsh 5% chromic acid for oxidization. Initially, we succeeded in reducing the concentration of chromic acid from 5% to 1% by incubating the solution at 60°C and using five-fold diluted chromic acid solution at which point it was reusable. Eventually, we reached the refusal level where 1% periodic acid oxidization was efficient enough, when combined with preheating of sections in the electric jar, microwave oven, or pressure pan. For convenience sake, we recommend pressure pan heating in tap water for 10 min. Stainability of fungi in candidiasis and aspergillosis was comparable with conventional Grocott stain, while Mucor hyphae showed enhanced staining. The modified sequence was further applicable to detecting a variety of mycotic pathogens in paraffin sections. Our environmentally-friendly Grocott stain also has the advantage of avoiding risk of human exposure to hexavalent chromium solution in the histopathology laboratory. The simple stain sequence is can be easily applied worldwide

  16. Port-wine stain

    Science.gov (United States)

    ... About MedlinePlus Show Search Search MedlinePlus GO GO About MedlinePlus Site Map FAQs Customer Support Health Topics Drugs & Supplements Videos & Tools Español You Are Here: Home → Medical Encyclopedia → Port-wine stain URL of this page: //medlineplus.gov/ency/ ...

  17. Stool Gram stain

    Science.gov (United States)

    ... stool sample. The Gram stain method is sometimes used to quickly diagnose bacterial infections. How the Test is Performed You will need to collect a stool sample. There are many ways to collect the sample. You can catch the stool on plastic wrap that is loosely placed over the toilet bowl ...

  18. Stained Glass and Flu

    Centers for Disease Control (CDC) Podcasts

    2017-02-01

    Dr. Robert Webster, an Emeritus member of the Department of Infectious Diseases at St. Jude Children's Research Hospital, discusses his cover art story on stained glass and influenza.  Created: 2/1/2017 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 2/1/2017.

  19. A quantitative comparison between electrocoagulation and chemical coagulation for boron removal from boron-containing solution

    International Nuclear Information System (INIS)

    Yilmaz, A. Erdem; Boncukcuoglu, Recep; Kocakerim, M. Muhtar

    2007-01-01

    This paper provides a quantitative comparison of electrocoagulation and chemical coagulation approaches based on boron removal. Electrocoagulation process delivers the coagulant in situ as the sacrificial anode corrodes, due to a fixed current density, while the simultaneous evolution of hydrogen at the cathode allows for pollutant removal by flotation. By comparison, conventional chemical coagulation typically adds a salt of the coagulant, with settling providing the primary pollutant removal path. Chemical coagulation was carried out via jar tests using aluminum chloride. Comparison was done with the same amount of coagulant between electrocoagulation and chemical coagulation processes. Boron removal obtained was higher with electrocoagulation process. In addition, it was seen that chemical coagulation has any effect for boron removal from boron-containing solution. At optimum conditions (e.g. pH 8.0 and aluminum dose of 7.45 g/L), boron removal efficiencies for electrocoagulation and chemical coagulation were 94.0% and 24.0%, respectively

  20. A quantitative comparison between electrocoagulation and chemical coagulation for boron removal from boron-containing solution

    Energy Technology Data Exchange (ETDEWEB)

    Yilmaz, A. Erdem [Atatuerk University, Faculty of Engineering, Department of Environmental Engineering, 25240 Erzurum (Turkey)], E-mail: aerdemy@atauni.edu.tr; Boncukcuoglu, Recep [Atatuerk University, Faculty of Engineering, Department of Environmental Engineering, 25240 Erzurum (Turkey); Kocakerim, M. Muhtar [Atatuerk University, Faculty of Engineering, Department of Chemical Engineering, 25240 Erzurum (Turkey)

    2007-10-22

    This paper provides a quantitative comparison of electrocoagulation and chemical coagulation approaches based on boron removal. Electrocoagulation process delivers the coagulant in situ as the sacrificial anode corrodes, due to a fixed current density, while the simultaneous evolution of hydrogen at the cathode allows for pollutant removal by flotation. By comparison, conventional chemical coagulation typically adds a salt of the coagulant, with settling providing the primary pollutant removal path. Chemical coagulation was carried out via jar tests using aluminum chloride. Comparison was done with the same amount of coagulant between electrocoagulation and chemical coagulation processes. Boron removal obtained was higher with electrocoagulation process. In addition, it was seen that chemical coagulation has any effect for boron removal from boron-containing solution. At optimum conditions (e.g. pH 8.0 and aluminum dose of 7.45 g/L), boron removal efficiencies for electrocoagulation and chemical coagulation were 94.0% and 24.0%, respectively.

  1. Modified Alizarin Red S-Alcian Blue Staining for Reptilian Skeleton

    Directory of Open Access Journals (Sweden)

    Muhammad Ja’far Luthfi

    2016-04-01

    Full Text Available Skeletal staining is an important method in anatomical study. The aim of the research was to develop staining and clearing method of Reptilian skeleton using Alizarin Red S-Alcian Blue. The specimen were eviscerated, fixed, stained, cleared, and keep in glycerine solution. This modified double-staining has successfully stain bone and cartilage of Reptilian.

  2. The Synthesis of Silver Nanoparticles Produced by Chemical Reduction of Silver Salt Solution

    International Nuclear Information System (INIS)

    Sri Budi Harmani; Dewi Sondari; Agus Haryono

    2008-01-01

    Described in this research are the synthesis of silver nanoparticle produced by chemical reduction of silver salt (silver nitrate AgNO 3 ) solution. As a reducer, sodium citrate (C 6 H 5 O 7 Na 3 ) was used. Preparation of silver colloid is done by using chemical reduction method. In typical experiment 150 ml of 1.10 -3 M AgNO 3 solution was heated with temperature variation such as 90, 100, 110 degree of Celsius. To this solution 15 ml of 1 % trisodium citrate was added into solution drop by drop during heating. During the process, solution was mixed vigorously. Solution was heated until colour's change is evident (pale yellow solution is formed). Then it was removed from the heating element and stirred until cooled to room temperature. Experimental result showed that diameter of silver nanoparticles in colloid solution is about 28.3 nm (Ag colloid, 90 o C); 19.9 nm (Ag colloid, 100 o C)and 26.4 nm (Ag colloid, 110 o C). Characterization of the silver nanoparticle colloid conducted by using UV-Vis Spectroscopy, Particles Size Analyzer (PSA) and Scanning Electron Microscope (SEM) indicate the produced structures of silver nanoparticles. (author)

  3. Viscous-shock-layer solutions for turbulent flow of radiating gas mixtures in chemical equilibrium

    Science.gov (United States)

    Anderson, E. C.; Moss, J. N.

    1975-01-01

    The viscous-shock-layer equations for hypersonic laminar and turbulent flows of radiating or nonradiating gas mixtures in chemical equilibrium are presented for two-dimensional and axially-symmetric flow fields. Solutions were obtained using an implicit finite-difference scheme and results are presented for hypersonic flow over spherically-blunted cone configurations at freestream conditions representative of entry into the atmosphere of Venus. These data are compared with solutions obtained using other methods of analysis.

  4. Viscous shock layer solutions for turbulent flow of radiating gas mixtures in chemical equilibrium

    Science.gov (United States)

    Anderson, E. C.; Moss, J. N.

    1975-01-01

    The viscous shock layer equations for hypersonic laminar and turbulent flows of radiating or nonradiating gas mixtures in chemical equilibrium are presented for two-dimensional and axially symmetric flow fields. Solutions are obtained using an implicit finite difference scheme and results are presented for hypersonic flow over spherically blunted cone configurations at free stream conditions representative of entry into the atmosphere of Venus. These data are compared with solutions obtained using other methods of analysis.

  5. Research on pre-staining gel electrophoresis

    International Nuclear Information System (INIS)

    Zhong Ruibo; Liu Yushuang; Zhang Ping; Liu Jingran; Zhao Guofen; Zhang Feng

    2014-01-01

    Background: Gel electrophoresis is a powerful biochemical separation technique. Most biological molecules are completely transparent in the visible region of light, so it is necessary to use staining to show the results after gel electrophoresis, and the general steps of conventional staining methods are time-consuming. Purpose: We try to develop a novel approach to simplify the gel electrophoresis: Pre-Staining Gel Electrophoresis (PSGE), which can make the gel electrophoresis results monitored in real time. Methods: Pre-stain the protein samples with Coomassie Brilliant Blue (CBB) for 30 min before loading the sample into the gel well. Results and Conclusion: PSGE can be successfully used to analyze the binding efficiency of Bovine Serum Albumin (BSA) and amphiphilic polymer via chemical coupling and physical absorption, and the double PSGE also shows a great potential in bio-analytical chemistry. (authors)

  6. Computational Protocols for Prediction of Solute NMR Relative Chemical Shifts. A Case Study of L-Tryptophan in Aqueous Solution

    DEFF Research Database (Denmark)

    Eriksen, Janus J.; Olsen, Jógvan Magnus H.; Aidas, Kestutis

    2011-01-01

    to the results stemming from the conformations extracted from the MM conformational search in terms of replicating an experimental reference as well as in achieving the correct sequence of the NMR relative chemical shifts of L-tryptophan in aqueous solution. We find this to be due to missing conformations......In this study, we have applied two different spanning protocols for obtaining the molecular conformations of L-tryptophan in aqueous solution, namely a molecular dynamics simulation and a molecular mechanics conformational search with subsequent geometry re-optimization of the stable conformers...... using a quantum mechanically based method. These spanning protocols represent standard ways of obtaining a set of conformations on which NMR calculations may be performed. The results stemming from the solute–solvent configurations extracted from the MD simulation at 300 K are found to be inferior...

  7. Modified Field's staining--a rapid stain for Trichomonas vaginalis.

    Science.gov (United States)

    Afzan, M Yusuf; Sivanandam, S; Kumar, G Suresh

    2010-10-01

    Trichomonas vaginalis, a flagellate protozoan parasite commonly found in the human genitourinary tract, is transmitted primarily by sexual intercourse. Diagnosis is usually by in vitro culture method and staining with Giemsa stain. There are laboratories that use Gram stain as well. We compared the use of modified Field's (MF), Giemsa, and Gram stains on 2 axenic and xenic isolates of T. vaginalis, respectively. Three smears from every sediment of spun cultures of all 4 isolates were stained, respectively, with each of the stains. We showed that MF staining, apart from being a rapid stain (20 s), confers sharper staining contrast, which differentiates the nucleus and the cytoplasm of the organism when compared to Giemsa and Gram staining especially on parasites from spiked urine samples. The alternative staining procedure offers in a diagnostic setting a rapid stain that can easily visualize the parasite with sharp contrasting characteristics between organelles especially the nucleus and cytoplasm. Vacuoles are more clearly visible in parasites stained with MF than when stained with Giemsa. Copyright © 2010 Elsevier Inc. All rights reserved.

  8. Determination of solute organic concentration in contaminated soils using a chemical-equilibrium soil column system

    DEFF Research Database (Denmark)

    Gamst, Jesper; Kjeldsen, Peter; Christensen, Thomas Højlund

    2007-01-01

    using two soils with different content of organic carbon (f(oc) of 1.5 and 6.5%, respectively). A quadruple blind test of the ER-V system using glass beads in stead of soil showed an acceptable recovery (65-85%) of all of the 11 VOCs tested. Only for the most volatile compound (heptane, K-H similar...... to 80) an unacceptable recovery was found (9%). The contact time needed for obtaining chemical equilibrium was tested in the ER-H system by performing five test with different duration (1, 2, 4, 7 and 19 days) using the low organic carbon soil. Seven days of contact time appeared sufficient...... for determination of solute concentration in a contaminated soil were developed; (1) a chemical Equilibrium and Recirculation column test for Volatile organic chemicals (ER-V) and (2) a chemical Equilibrium and Recirculation column test for Hydrophobic organic chemicals (ER-H). The two test systems were evaluated...

  9. Chemical composition and Zn bioavailability of the soil solution extracted from Zn amended variable charge soils.

    Science.gov (United States)

    Zampella, Mariavittoria; Adamo, Paola

    2010-01-01

    A study on variable charge soils (volcanic Italian and podzolic Scottish soils) was performed to investigate the influence of soil properties on the chemical composition of soil solution. Zinc speciation, bioavailability and toxicity in the soil solution were examined. The soils were spiked with increasing amounts of Zn (0, 100, 200, 400 and 1000 mg/kg) and the soil solutions were extracted using rhizon soil moisture samplers. The pH, total organic carbon (TOC), base cations, anions, total Zn and free Zn2+ in soil solution were analysed. A rapid bioassay with the luminescent bacterium Escherichia coli HB101 pUCD607 was performed to assess Zn toxicity. The influence of soil type and Zn treatments on the chemical composition of soil solution and on Zn toxicity was considered and discussed. Different trends of total and free Zn concentrations, base cations desorption and luminescence of E. coli HB101 pUCD607 were observed. The soil solution extracted from the volcanic soils had very low total and free Zn concentrations and showed specific Zn2+/Ca2+ exchange. The soil solution from the podzolic soil had much higher total and free Zn concentrations and showed no evidence of specific Zn2+/Ca2+ exchange. In comparison with the subalkaline volcanic soils, the acidic podzol showed enhanced levels of toxic free Zn2+ and consequently stronger effects on E. coli viability.

  10. Chemical solution deposition of CaCu3Ti4O12 thin film

    Indian Academy of Sciences (India)

    Administrator

    CaCu3Ti4O12; thin film; chemical solution deposition; dielectric properties. 1. Introduction. The CaCu3Ti4O12. (CCTO) compound has recently attracted considerable ... and Kelvin probe force microscopy (Chung et al 2004). Intrinsic .... SEM images of CCTO thin films as a function of sintering temperature. silicon based ...

  11. Epitaxial ternary nitride thin films prepared by a chemical solution method

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Hongmei [Los Alamos National Laboratory; Feldmann, David M [Los Alamos National Laboratory; Wang, Haiyan [TEXAS A& M; Bi, Zhenxing [TEXAS A& M

    2008-01-01

    It is indispensable to use thin films for many technological applications. This is the first report of epitaxial growth of ternary nitride AMN2 films. Epitaxial tetragonal SrTiN2 films have been successfully prepared by a chemical solution approach, polymer-assisted deposition. The structural, electrical, and optical properties of the films are also investigated.

  12. NMR determination of chemically related metals in solution as a new method of inorganic analysis

    International Nuclear Information System (INIS)

    Fedorov, L.A.

    1989-01-01

    An NMR spectroscopic method for the determination of chemically related metals in solution is suggested. The metals are determined in complexes with specially selected polydentate ligands. Structural requirements to ligands, analytical properties and general limits of the application of the method are discussed. (orig.)

  13. A Two-Level Undercut-Profile Substrate for Chemical-Solution-Based Filamentary Coated Conductors

    DEFF Research Database (Denmark)

    Wulff, Anders Christian; Lundeman, Jesper H.; Hansen, Jørn B.

    2016-01-01

    . In the present study, the 2LUPS concept is applied to a commercial cube-textured Ni-5at.% W tape, and the surface of the 2LUPS coated with two Gd2Zr2O7 buffer layers using chemical solution deposition is examined. Except for narrow regions near the edge of upper plateaus, the plateaus are found to be covered...

  14. Chemical solution deposition of CaCu 3 Ti 4 O 12 thin film

    Indian Academy of Sciences (India)

    CaCu3Ti4O12 (CCTO) thin film was successfully deposited on boron doped silica substrate by chemical solution deposition and rapid thermal processing. The phase and microstructure of the deposited films were studied as a function of sintering temperature, employing X-ray diffractometry and scanning electron ...

  15. Alcian blue-stained particles in a eutrophic lake

    DEFF Research Database (Denmark)

    Worm, J.; Søndergaard, Morten

    1998-01-01

    We used a neutral solution of Alcian Blue to stain transparent particles in eutrophic Lake Frederiksborg Slotss0, Denmark. Alcian Blue-stained particles (ABSP) appeared to be similar to the so-called transparent exopolymer particles (TEP) identified with an acidic solution of Alcian Blue. Our...

  16. Influence of chemical heterogeneity of solid solutions on brittleness in chromium steels

    International Nuclear Information System (INIS)

    Madyanov, S.A.; Sedov, V.K.; Apaev, B.A.

    1985-01-01

    The role of chemical heterogeneity of solid solutions in formation of mechanical properties of Kh09, Kh15, Kh20, Kh19N2G5T chromium steels has been investigated. It is established that besides the known regioA of chemical heterogeneity in the vicinity of 475 deg C exists a high-temperature region (1000-1050 deg C), where maximum heteroge=- neity of chromium distribution in solid solution, is observed. Both types of chemical heterogeneity cause essential hardening of alloys, which becomes apparent in abrupt change of capability to microplastic deformation The mechanism of occurrence of the given temper brittleness consists in carbon diffusion into microvolunes enriched in carbide-forming elements

  17. Numerical solutions of several reflected shock-wave flow fields with nonequilibrium chemical reactions

    Science.gov (United States)

    Hanson, R. K.; Presley, L. L.; Williams, E. V.

    1972-01-01

    The method of characteristics for a chemically reacting gas is used in the construction of the time-dependent, one-dimensional flow field resulting from the normal reflection of an incident shock wave at the end wall of a shock tube. Nonequilibrium chemical reactions are allowed behind both the incident and reflected shock waves. All the solutions are evaluated for oxygen, but the results are generally representative of any inviscid, nonconducting, and nonradiating diatomic gas. The solutions clearly show that: (1) both the incident- and reflected-shock chemical relaxation times are important in governing the time to attain steady state thermodynamic properties; and (2) adjacent to the end wall, an excess-entropy layer develops wherein the steady state values of all the thermodynamic variables except pressure differ significantly from their corresponding Rankine-Hugoniot equilibrium values.

  18. Effect of textural and chemical characteristics of activated carbons on phenol adsorption in aqueous solutions

    Directory of Open Access Journals (Sweden)

    Vargas Diana P.

    2017-12-01

    Full Text Available The effect of textural and chemical properties such as: surface area, pore volume and chemical groups content of the granular activated carbon and monoliths on phenol adsorption in aqueous solutions was studied. Granular activated carbon and monolith samples were produced by chemical activation. They were characterized by using N2 adsorption at 77 K, CO2 adsorption at 273 K, Boehm Titrations and immersion calorimetry in phenol solutions. Microporous materials with different pore size distribution, surface area between 516 and 1685 m2 g−1 and pore volumes between 0.24 and 0.58 cm3 g−1 were obtained. Phenol adsorption capacity of the activated carbon materials increased with increasing BET surface area and pore volume, and is favored by their surface functional groups that act as electron donors. Phenol adsorption capacities are in ranged between 73.5 and 389.4 mg · g−1.

  19. Radiation-chemical behaviour of Rh(4) in perchlorate and nitrate solutions

    International Nuclear Information System (INIS)

    Vladimirova, M.V.; Khalkina, E.V.

    1994-01-01

    Kinetic of rhodium(4) reduction in the process of radiolysis in solutions of perchloric (0.6-3.2 mol/l) and nitric (2-9 mol/l) acids with rhodium (4) concentration (0.4-5)x10 -3 mol/l has been studied. Irradiation of the solutions was carried out using a 60 Co source with dose rate of 3.5 Gy/s in the absorbed dose range up to 10 4 Gy. A mechanism of radiation-chemical reduction of rhodium(4) in perchloric and nitric acid solutions in suggested, the reason for high radiation-chemical yields of reduction is discussed. 7 refs.; 9 figs.; 2 tabs

  20. A mathematical model for chemical reactions with actinide elements in the aqueous nitric acid solution: REACT

    International Nuclear Information System (INIS)

    Tachimori, Shoichi

    1990-02-01

    A mathematical model of chemical reactions with actinide elements: REACT code, was developed to simulate change of valency states of U, Pu and Np in the aqueous nitric acid solution. Twenty seven rate equations for the redox reactions involving some reductants, disproportionation reactions, and radiolytic growth and decay reaction of nitrous acid were programmed in the code . Eight numerical solution methods such as Porsing method to solve the rate equations were incorporated parallel as options depending on the characteristics of the reaction systems. The present report gives a description of the REACT code, e.g., chemical reactions and their rate equations, numerical solution methods, and some examples of the calculation results. A manual and a source file of the program was attached to the appendix. (author)

  1. Investigation of radiation-chemical behaviour of divalent palladium in perchloric acid solutions

    International Nuclear Information System (INIS)

    Vladimirova, M.V.; Kalinina, S.V.

    1988-01-01

    Gamma-radiolysis of divalent palladium in perchloric acid solutions is studied. Absorption spectra of intermediate palladium compounds formed in the irradiated solution are taken. The analysis of literature data as well as comparative analysis of the absorption spectra obtained under irradiation of palladium (2) perchloric acid solutions with absorption spectra of palladium chlorocomplexes allows to suppose that the mentioned compounds are chlorocomplexes of palladium (2) of different composition depending on HClO 4 concentration in the initial solution and absorbed radiation dose. Radiation-chemical reduction of palladium (2) up to metal is stated to take place in the whole studied range of initial concentrations of components of the system and dose rates. Kinetic dependences of metallic palladium formation are obtained. Values of radiation-chemical yields of metallic palladium formation depending on the initial concentrations of palladium (2) and perchloric acid are given. A mechanism of radiolytic reduction of palladium (2) in the investigated system is suggested based on the experimental data, and a theoretical value of the radiation-chemical yield of palladium (2) reduction being in a good agreement with experimentally found values is calculated

  2. Chemical solution synthesis and ferromagnetic resonance of epitaxial thin films of yttrium iron garnet

    Science.gov (United States)

    Lucas, Irene; Jiménez-Cavero, Pilar; Vila-Fungueiriño, J. M.; Magén, Cesar; Sangiao, Soraya; de Teresa, José Maria; Morellón, Luis; Rivadulla, Francisco

    2017-12-01

    We report the fabrication of epitaxial Y3F e5O12 (YIG) thin films on G d3G a5O12 (111) using a chemical solution method. Cubic YIG is a ferrimagnetic material at room temperature, with excellent magneto-optical properties, high electrical resistivity, and a very narrow ferromagnetic resonance, which makes it particularly suitable for applications in filters and resonators at microwave frequencies. But these properties depend on the precise stoichiometry and distribution of F e3 + ions among the octahedral/tetrahedral sites of a complex structure, which hampered the production of high-quality YIG thin films by affordable chemical methods. Here we report the chemical solution synthesis of YIG thin films, with excellent chemical, crystalline, and magnetic homogeneity. The films show a very narrow ferromagnetic resonance (long spin relaxation time), comparable to that obtained from high-vacuum physical deposition methods. These results demonstrate that chemical methods can compete to develop nanometer-thick YIG films with the quality required for spintronic devices and other high-frequency applications.

  3. Chemical dosimetry at less than 1000 rad: aqueous trimesic acid solutions

    International Nuclear Information System (INIS)

    Matthews, R.W.; Wilson, J.G.

    1981-01-01

    Aqueous solutions of trimesic acid were investigated for possible use as a chemical dosimeter. In aerated 10 -2 M sulphuric acid solution containing 10 -3 M trimesic acid, a highly fluorescent product is formed with its maximum fluorescence at 450nm when excited by 350nm light. The product has fluorescence characteristics very similar to quinine in 0.05 M sulphuric acid. The fluorescence intensity is linear with dose in the range 1-1000 rad and a precision of +-2% was obtained from a number of runs. Solutions are stable for at least several days before and after irradiation. The yield is little affected by moderate changes in trimesic acid concentration, oxygen concentration, water purity, energy of radiation and irradiation temperature. The small dependence of the yield on dose rate and the effect of measurement temperature on the fluorescence signal have been quantified. The most significant factor affecting the fluorescence signal is the hydrogen ion concentration of the solution. In aerated neutral and alkaline (pH 10) solutions, hydroxytrimesic acid (HTMA) is formed with G(HTMA) equal to 2.07 +- 0.04 and 2.21 +- 0.04, for 10 -3 M trimesate. In these solutions, G(HTMA) increases appreciably with increase in the trimesate concentration. The main fluorescent product formed in irradiated acid solutions was not identified but it was not HTMA. (author)

  4. General-purpose chemical analyzer for on-line analyses of radioactive solutions

    International Nuclear Information System (INIS)

    Spencer, W.A.; Kronberg, J.W.

    1983-01-01

    An automated analyzer is being developed to perform analytical measurements on radioactive solutions on-line in a hostile environment. This General Purpose Chemical Analyzer (GPCA) samples a process stream, adds reagents, measures solution absorbances or electrode potentials, and automatically calculates the results. The use of modular components, under microprocessor control, permits a single analyzer design to carry out many types of analyses. This paper discusses the more important design criteria for the GPCA, and describes the equipment being tested in a prototype unit

  5. Orientation control of chemical solution deposited LaNiO3 thin films

    International Nuclear Information System (INIS)

    Ueno, Kengo; Yamaguchi, Toshiaki; Sakamoto, Wataru; Yogo, Toshinobu; Kikuta, Koichi; Hirano, Shin-ichi

    2005-01-01

    High quality LaNiO 3 (LNO) thin films with preferred orientation could be synthesized on Pt/Ti/SiO 2 /Si substrates at 700 deg. C using the chemical solution deposition method. The homogeneous and stable LNO precursor solutions were prepared using lanthanum isopropoxide and nickel (II) acetylacetonate in a mixed solvent of absolute ethanol and 2-methoxyethanol. The oriented LNO thin films exhibit metallic electro-conduction, and their resistivity at room temperature is sufficiently low for making them an alternative electrode material for functional ceramic thin films

  6. Controlled growth of epitaxial CeO2 thin films with self-organized nanostructure by chemical solution method

    DEFF Research Database (Denmark)

    Yue, Zhao; Grivel, Jean-Claude

    2013-01-01

    Chemical solution deposition is a versatile technique to grow oxide thin films with self-organized nanostructures. Morphology and crystallographic orientation control of CeO2 thin films grown on technical NiW substrates by a chemical solution deposition method are achieved in this work. Based...

  7. Comparison of chemical solution deposition systems for the fabrication of lead zirconate titanate thin films

    International Nuclear Information System (INIS)

    Lecarpentier, F.; Daglish, M.; Kemmitt, T.

    2001-01-01

    Ferroelectric thin films of lead zirconate titanate Pb(Zr x Ti 1-x )O 3 (PZT) were prepared from five chemical solution deposition (CSD) systems, namely methoxyethanol, citrate, diol, acetic acid and triethanolamine. Physical characteristics of the solutions, processing parameters and physical and electrical properties of the films were used to assess the relative advantages and disadvantages of the different chemical systems. All the CSD systems decomposed to produce single phase perovskite PZT at temperatures above 650 deg C. Thin film deposition was influenced by the specific characteristics of each system such as wetting on the substrate and viscosity. Distinct precursor effects on the thin film crystallinity and electrical performance were revealed. The diol route yielded films with the highest crystallite size, highest permittivity and lowest loss tangent. The relative permittivity exhibited by films made by the other routes were 25% to 35% lower at equivalent thicknesses. Copyright (2001) The Australian Ceramic Society

  8. Preparation of potassium tantalate niobate thin films by chemical solution deposition and their characterization

    Czech Academy of Sciences Publication Activity Database

    Buršík, Josef; Železný, Vladimír; Vaněk, Přemysl

    2005-01-01

    Roč. 25, č. 12 (2005), s. 2151-2154 ISSN 0955-2219 R&D Projects: GA ČR GA202/02/0238; GA MŠk(CZ) LN00A028; GA MŠk OC 528.001 Institutional research plan: CEZ:AV0Z40320502 Keywords : films * tantalates * chemical solution deposition Subject RIV: CA - Inorganic Chemistry Impact factor: 1.567, year: 2005

  9. Physical and chemical stability of palonosetron HCl in 4 infusion solutions.

    Science.gov (United States)

    Trissel, Lawrence A; Xu, Quanyun A

    2004-10-01

    Palonosetron HCl is a selective 5-HT(3) receptor antagonist used for the prevention of chemotherapy-induced nausea and vomiting. Palonosetron HCl may be diluted in an infusion solution for administraton. Consequently, stability information is needed for palonosetron HCl admixed in common infusion solutions. To evaluate the physical and chemical stability of palonosetron HCl in concentrations of 5 and 30 microg/mL in dextrose 5% injection, NaCl 0.9% injection, dextrose 5% in NaCl 0.45% injection, and dextrose 5% in lactated Ringer's injection. Triplicate test samples of palonosetron HCl at each concentration in each diluent were tested. Samples were stored and evaluated at appropriate intervals for up to 48 hours at room temperature ( approximately 23 degrees C) and 14 days under refrigeration (4 degrees C). Physical stability was assessed using turbidimetric and particulate measurement, as well as visual inspection. Chemical stability was assessed by HPLC. All of the admixtures were initially clear and colorless when viewed in normal fluorescent room light and with a Tyndall beam. Measured turbidity and particulate content were low initially and remained low throughout the study. The drug concentration was unchanged in any of the samples at either temperature throughout the study. Palonosetron HCl is physically and chemically stable in all 4 common infusion solutions for at least 48 hours at room temperature and 14 days under refrigeration.

  10. Thinning of CIGS solar cells: Part I: Chemical processing in acidic bromine solutions

    Energy Technology Data Exchange (ETDEWEB)

    Bouttemy, M.; Tran-Van, P. [Institut Lavoisier de Versailles (ILV-UMR 8180 CNRS/UVSQ), 45 av. des Etats Unis, 78035 Versailles (France); Gerard, I., E-mail: gerard@chimie.uvsq.fr [Institut Lavoisier de Versailles (ILV-UMR 8180 CNRS/UVSQ), 45 av. des Etats Unis, 78035 Versailles (France); Hildebrandt, T.; Causier, A. [Institut Lavoisier de Versailles (ILV-UMR 8180 CNRS/UVSQ), 45 av. des Etats Unis, 78035 Versailles (France); Pelouard, J.L.; Dagher, G. [Laboratoire de Photonique et de Nanostructures (LPN-CNRS), route de Nozay 91460 Marcoussis (France); Jehl, Z.; Naghavi, N. [Institut de Recherche et Developpement sur l' Energie Photovoltaique (IRDEP -UMR 7174 CNRS/EDF/Chimie-ParisTech), 6 quai Watier, 78401 Chatou (France); Voorwinden, G.; Dimmler, B. [Wuerth Elektronik Research GmbH, Industriestr. 4, 70565 Stuttgart (Germany); Powalla, M. [Zentrum fuer Sonnenenergie- und Wasserstoff-Forschung (ZSW), Industriestr. 6, 70565 Stuttgart (Germany); Guillemoles, J.F. [Institut de Recherche et Developpement sur l' Energie Photovoltaique (IRDEP -UMR 7174 CNRS/EDF/Chimie-ParisTech), 6 quai Watier, 78401 Chatou (France); Lincot, D. [Laboratoire de Photonique et de Nanostructures (LPN-CNRS), route de Nozay 91460 Marcoussis (France); Etcheberry, A. [Institut Lavoisier de Versailles (ILV-UMR 8180 CNRS/UVSQ), 45 av. des Etats Unis, 78035 Versailles (France)

    2011-08-31

    CIGSe absorber was etched in HBr/Br{sub 2}/H{sub 2}O to prepare defined thicknesses of CIGSe between 2.7 and 0.5 {mu}m. We established a reproducible method of reducing the absorber thickness via chemical etching. We determine the dissolution kinetics rate of CIGSe using trace analysis by graphite furnace atomic absorption spectrometry of Ga and Cu. The roughness of the etching surface decreases during the first 500 nm of the etching to a steady state value of the root-mean-square roughness near 50 nm. X-ray photoelectron spectroscopy analyses demonstrate an etching process occurring with a constant chemical composition of the treated surface acidic bromine solutions provide a controlled chemical thinning process resulting in an almost flat surface and a very low superficial Se{sup 0} enrichment.

  11. Chemical and physical stability of smectites and illite in electrolyte solutions: experimental study at 150 C

    International Nuclear Information System (INIS)

    Boutiche, M.

    1995-01-01

    Chemical interactions between electrolytic solutions commonly used i drilling muds and clays have been studies under P-T conditions similar to those of drillings (150 deg C) in order to determine the eventual consequences on the stability of clay rich formations. The experimental work has been carried out using several solutions (water, NaOH (pH 8, 10, 12), KCI (0,1, 1 2 mol./l), sea water, and K 2 CO 3 ) and clay minerals with low to high amounts of swelling layers (smectite (Na, Na-Ca, Ca), mixed layered illite-smectite minerals). Run products are studied by X-ray diffraction and electronic microprobe. Smectite layers show series of mineralogical changes (cation exchange in the interlayer site, formation of non-swelling layers, hydrolysis), which, however, do not yield to the formation of new minerals, except in the case of the interaction with K 2 CO 3 at 150 deg C (zeolite crystallisation). Cation exchange in the interlayer depends on the nature of the cation, cation concentration in the solution, exchange constants, and liquid/solid ratio. In dilute solutions ( 1 mol./l), because they favour the collapse of swelling layers, and dispersion. Solutions of K 2 CO 3 at 150 deg C are at the origin of the transformation of smectite to zeolites, and high pH - highly saline solutions are rather aggressive, and would probably not stabilize the argilites. (author)

  12. Combined LAURA-UPS solution procedure for chemically-reacting flows. M.S. Thesis

    Science.gov (United States)

    Wood, William A.

    1994-01-01

    A new procedure seeks to combine the thin-layer Navier-Stokes solver LAURA with the parabolized Navier-Stokes solver UPS for the aerothermodynamic solution of chemically-reacting air flowfields. The interface protocol is presented and the method is applied to two slender, blunted shapes. Both axisymmetric and three dimensional solutions are included with surface pressure and heat transfer comparisons between the present method and previously published results. The case of Mach 25 flow over an axisymmetric six degree sphere-cone with a noncatalytic wall is considered to 100 nose radii. A stability bound on the marching step size was observed with this case and is attributed to chemistry effects resulting from the noncatalytic wall boundary condition. A second case with Mach 28 flow over a sphere-cone-cylinder-flare configuration is computed at both two and five degree angles of attack with a fully-catalytic wall. Surface pressures are seen to be within five percent with the present method compared to the baseline LAURA solution and heat transfers are within 10 percent. The effect of grid resolution is investigated and the nonequilibrium results are compared with a perfect gas solution, showing that while the surface pressure is relatively unchanged by the inclusion of reacting chemistry the nonequilibrium heating is 25 percent higher. The procedure demonstrates significant, order of magnitude reductions in solution time and required memory for the three dimensional case over an all thin-layer Navier-Stokes solution.

  13. Formation of by-products at radiation - chemical treatment of water solutions of chloroform

    International Nuclear Information System (INIS)

    Ahmedov, S.A.; Abdullayev, E.T.; Gurbanov, M.A.; Gurbanov, A.H.; Ibadov, N.A.

    2006-01-01

    Full text: Radiation-chemical treatment is considered as a perspective method of water purification from chloroform. It provides the high level of purification (98 percent) of water solutions from chloroform and other chlorine-containing compounds. Meanwhile, other chlorine-containing products can be formed during the process of chloroform degradation and as a result of it the quality of water can change. This work studies the formation of by-products of γ-radiolysis of water solutions at various initial contents of chloroform. Dichlormethane and tetrachlorethane are identified as by-products. It is shown that at high contents of chloroform after certain adsorbed dose the forming products are reducing till their full disappearing. At small contents of chloroform in the studied interval of doses di-chlor-methane is forming. Differences of dose dependences of by-products at various contents of chloroform can be connected with the transition from radical mechanism to chain reaction at high concentrations of chloroform in solutions saturated by oxygen. pH-solutions also reduces during the radiation till pH=1, although this reduction also depends on initial concentration of chloroform. Essential change of pH occurs only at the radiolysis of water solutions containing chloroform ≥0,2 percent. And at radiating of 0,03 percent solution pH reduces only till 4 - 4,5

  14. Molecular interactions in ethyl acetate-chlorobenzene binary solution: Dielectric, spectroscopic studies and quantum chemical calculations

    Science.gov (United States)

    Karthick, N. K.; Kumbharkhane, A. C.; Joshi, Y. S.; Mahendraprabu, A.; Shanmugam, R.; Elangovan, A.; Arivazhagan, G.

    2017-05-01

    Dielectric studies using Time Domain Reflectometry method has been carried out on the binary solution of Ethyl acetate (EA) with Chlorobenzene (CBZ) over the entire composition range. Spectroscopic (FTIR and 13C NMR) signatures of neat EA, CBZ and their equimolar binary solution have also been recorded. The results of the spectroscopic studies favour the presence of (CBZ) Csbnd H ⋯ Odbnd C (EA), (EA) methylene Csbnd H ⋯ π electrons (CBZ) and (EA) methyl Csbnd H ⋯ Cl (CBZ) contacts which have been validated using quantum chemical calculations. Dimerization of CBZ has been identified. Presence of β-clusters has been identified in all the solutions. Although EA and CBZ molecules have nearly equal molar volumes, CBZ molecules experience larger hindrance for the rotation than EA molecules. Very small excess dielectric constant (εE) values may be correlated with weak heteromolecular forces and/or closed heteromolecular association.

  15. Chemical nonequilibrium Navier-Stokes solutions for hypersonic flow over an ablating graphite nosetip

    Science.gov (United States)

    Chen, Y. K.; Henline, W. D.

    1993-01-01

    The general boundary conditions including mass and energy balances of chemically equilibrated or nonequilibrated gas adjacent to ablating surfaces have been derived. A computer procedure based on these conditions was developed and interfaced with the Navier-Stokes solver for predictions of the flow field, surface temperature, and surface ablation rates over re-entry space vehicles with ablating Thermal Protection Systems (TPS). The Navier-Stokes solver with general surface thermochemistry boundary conditions can predict more realistic solutions and provide useful information for the design of TPS. A test case with a proposed hypersonic test vehicle configuration and associated free stream conditions was developed. Solutions with various surface boundary conditions were obtained, and the effect of nonequilibrium gas as well as surface chemistry on surface heating and ablation rate were examined. The solutions of the GASP code with complete ablating surface conditions were compared with those of the ASC code. The direction of future work is also discussed.

  16. Optimal Solutions of Multiproduct Batch Chemical Process Using Multiobjective Genetic Algorithm with Expert Decision System

    Science.gov (United States)

    Mokeddem, Diab; Khellaf, Abdelhafid

    2009-01-01

    Optimal design problem are widely known by their multiple performance measures that are often competing with each other. In this paper, an optimal multiproduct batch chemical plant design is presented. The design is firstly formulated as a multiobjective optimization problem, to be solved using the well suited non dominating sorting genetic algorithm (NSGA-II). The NSGA-II have capability to achieve fine tuning of variables in determining a set of non dominating solutions distributed along the Pareto front in a single run of the algorithm. The NSGA-II ability to identify a set of optimal solutions provides the decision-maker DM with a complete picture of the optimal solution space to gain better and appropriate choices. Then an outranking with PROMETHEE II helps the decision-maker to finalize the selection of a best compromise. The effectiveness of NSGA-II method with multiojective optimization problem is illustrated through two carefully referenced examples. PMID:19543537

  17. Rheology and physical-chemical characteristics of the solutions of the medicines

    International Nuclear Information System (INIS)

    Urakov, A; Urakova, N

    2015-01-01

    In the laboratory studied the dynamics of rheology of water solutions with plasma- inflammatory and antiseptic funds when mixing them with blood, plasma and pus under the influence of the following physical and chemical factors of local interaction: gravity, specific gravity, temperature, relative viscosity, internal pressure, sparkling water, total concentration of the ingredients, surface activity, volume of acid and osmotic activity of medicines. Found that the rheology of biological liquids improve hyperthermic, highly alkaline and highly carbonated solution medicines. For the dilution of pus, dense festering mass of sulfur plugs and tear stones invited to apply heated to +39 – +42°C with aqueous solution of 0.5 – 3% hydrogen peroxide and 0.5 – 10% sodium bicarbonate saturated with carbon dioxide to excess pressure 0.2 ATM. (paper)

  18. A decontamination system for chemical weapons agents using a liquid solution on a solid sorbent.

    Science.gov (United States)

    Waysbort, Daniel; McGarvey, David J; Creasy, William R; Morrissey, Kevin M; Hendrickson, David M; Durst, H Dupont

    2009-01-30

    A decontamination system for chemical warfare agents was developed and tested that combines a liquid decontamination reagent solution with solid sorbent particles. The components have fewer safety and environmental concerns than traditional chlorine bleach-based products or highly caustic solutions. The liquid solution, based on Decon Greentrade mark, has hydrogen peroxide and a carbonate buffer as active ingredients. The best solid sorbents were found to be a copolymer of ethylene glycol dimethacrylate and n-lauryl methacrylate (Polytrap 6603 Adsorber); or an allyl methacrylate cross-linked polymer (Poly-Pore E200 Adsorber). These solids are human and environmentally friendly and are commonly used in cosmetics. The decontaminant system was tested for reactivity with pinacolyl methylphosphonofluoridate (Soman, GD), bis(2-chloroethyl)sulfide (Mustard, HD), and S-(2-diisopropylaminoethyl) O-ethyl methylphosphonothioate (VX) by using NMR Spectroscopy. Molybdate ion (MoO(4)(-2)) was added to the decontaminant to catalyze the oxidation of HD. The molybdate ion provided a color change from pink to white when the oxidizing capacity of the system was exhausted. The decontaminant was effective for ratios of agent to decontaminant of up to 1:50 for VX (t(1/2) decontamination solution were measured to show that the sorbent decreased the vapor concentration of GD. The E200 sorbent had the additional advantage of absorbing aqueous decontamination solution without the addition of an organic co-solvent such as isopropanol, but the rate depended strongly on mixing for HD.

  19. Chemical Changes in Nonthermal Plasma-Treated N-Acetylcysteine (NAC) Solution and Their Contribution to Bacterial Inactivation.

    Science.gov (United States)

    Ercan, Utku K; Smith, Josh; Ji, Hai-Feng; Brooks, Ari D; Joshi, Suresh G

    2016-02-02

    In continuation of our previous reports on the broad-spectrum antimicrobial activity of atmospheric non-thermal dielectric barrier discharge (DBD) plasma treated N-Acetylcysteine (NAC) solution against planktonic and biofilm forms of different multidrug resistant microorganisms, we present here the chemical changes that mediate inactivation of Escherichia coli. In this study, the mechanism and products of the chemical reactions in plasma-treated NAC solution are shown. UV-visible spectrometry, FT-IR, NMR, and colorimetric assays were utilized for chemical characterization of plasma treated NAC solution. The characterization results were correlated with the antimicrobial assays using determined chemical species in solution in order to confirm the major species that are responsible for antimicrobial inactivation. Our results have revealed that plasma treatment of NAC solution creates predominantly reactive nitrogen species versus reactive oxygen species, and the generated peroxynitrite is responsible for significant bacterial inactivation.

  20. Transparent conducting oxide films of group V doped titania prepared by aqueous chemical solution deposition

    International Nuclear Information System (INIS)

    Elen, Ken; Capon, Boris; De Dobbelaere, Christopher; Dewulf, Daan; Peys, Nick; Detavernier, Christophe; Hardy, An; Van Bael, Marlies K.

    2014-01-01

    Transparent conducting oxide (TCO) films of titania doped with vanadium (V), niobium (Nb) and tantalum (Ta) are obtained by aqueous Chemical Solution Deposition (CSD). The effect of the dopant on the crystallization and microstructure of the resulting films is examined by means of X-ray diffraction and electron microscopy. During annealing of the thin films, in-situ characterization of the crystal structure and sheet resistance is carried out. Niobium doped anatase films, obtained after annealing in forming gas, show a resistivity of 0,28 Ohm cm, which is the lowest resistivity reported for a solution deposited anatase-based TCO so far. Here, we demonstrate that aqueous CSD may provide a strategy for scalable TCO production in the future. - Highlights: • Aqueous chemical solution deposition of doped titanium dioxide • Doping delays the phase transition from anatase to rutile • Lowest resistivity after doping with niobium and annealing in Forming Gas • Transparency higher than 80% in the visible range of optical spectrum

  1. Transparent conducting oxide films of group V doped titania prepared by aqueous chemical solution deposition

    Energy Technology Data Exchange (ETDEWEB)

    Elen, Ken [Inorganic and Physical Chemistry, Institute for Materials Research, Hasselt University, Agoralaan Building D, B-3590 Diepenbeek (Belgium); IMEC vzw division IMOMEC, Agoralaan Building D, B-3590 Diepenbeek (Belgium); Strategisch Initiatief Materialen (SIM), SoPPoM Program (Belgium); Capon, Boris [Strategisch Initiatief Materialen (SIM), SoPPoM Programm (Belgium); Coating and Contacting of Nanostructures, Ghent University, Krijgslaan 281 S1, B-9000 Ghent (Belgium); De Dobbelaere, Christopher [Inorganic and Physical Chemistry, Institute for Materials Research, Hasselt University, Agoralaan Building D, B-3590 Diepenbeek (Belgium); Dewulf, Daan [Inorganic and Physical Chemistry, Institute for Materials Research, Hasselt University, Agoralaan Building D, B-3590 Diepenbeek (Belgium); IMEC vzw division IMOMEC, Agoralaan Building D, B-3590 Diepenbeek (Belgium); Peys, Nick [Inorganic and Physical Chemistry, Institute for Materials Research, Hasselt University, Agoralaan Building D, B-3590 Diepenbeek (Belgium); IMEC vzw, Kapeldreef 75, B-3001 Heverlee (Belgium); Detavernier, Christophe [Coating and Contacting of Nanostructures, Ghent University, Krijgslaan 281 S1, B-9000 Ghent (Belgium); Hardy, An [Inorganic and Physical Chemistry, Institute for Materials Research, Hasselt University, Agoralaan Building D, B-3590 Diepenbeek (Belgium); IMEC vzw division IMOMEC, Agoralaan Building D, B-3590 Diepenbeek (Belgium); Van Bael, Marlies K., E-mail: marlies.vanbael@uhasselt.be [Inorganic and Physical Chemistry, Institute for Materials Research, Hasselt University, Agoralaan Building D, B-3590 Diepenbeek (Belgium); IMEC vzw division IMOMEC, Agoralaan Building D, B-3590 Diepenbeek (Belgium)

    2014-03-31

    Transparent conducting oxide (TCO) films of titania doped with vanadium (V), niobium (Nb) and tantalum (Ta) are obtained by aqueous Chemical Solution Deposition (CSD). The effect of the dopant on the crystallization and microstructure of the resulting films is examined by means of X-ray diffraction and electron microscopy. During annealing of the thin films, in-situ characterization of the crystal structure and sheet resistance is carried out. Niobium doped anatase films, obtained after annealing in forming gas, show a resistivity of 0,28 Ohm cm, which is the lowest resistivity reported for a solution deposited anatase-based TCO so far. Here, we demonstrate that aqueous CSD may provide a strategy for scalable TCO production in the future. - Highlights: • Aqueous chemical solution deposition of doped titanium dioxide • Doping delays the phase transition from anatase to rutile • Lowest resistivity after doping with niobium and annealing in Forming Gas • Transparency higher than 80% in the visible range of optical spectrum.

  2. Passivation of mechanically polished, chemically etched and anodized zirconium in various aqueous solutions: Impedance measurements

    International Nuclear Information System (INIS)

    Abo-Elenien, G.M.; Abdel-Salam, O.E.

    1987-01-01

    Zirconium and its alloys are finding increasing applications especially in water-cooled nuclear reactors. Because of the fact that zirconium is electronegative (E 0 = -1.529V) its corrosion resistance in aqueous solutions is largely determined by the existence of a thin oxide film on its surface. The structure and properties of this film depend in the first place on the method of surface pre-treatment. This paper presents an experimental study of the nature of the oxide film on mechanically polished, chemically etched and anodized zirconium. Ac impedance measurements carried out in various acidic, neutral and alkaline solutions show that the film thickness depends on the method of surface pre-treatment and the type of electrolyte solution. The variation of the potential and impedance during anodization of zirconium at low current density indicates that the initial stages of polarization consist of oxide build-up at a rate dependent on the nature of the electrode surface and the electrolyte. Oxygen evolution commences at a stage where oxide thickening starts to decline. The effect of frequency on the measured impedance indicates that the surface reactivity, and hence the corrosion rate, decreases in the following order: mechanically polished > chemically etched > anodized

  3. Chemical and physical compatibility of an intravenous solution of epinephrine with calcium chloride.

    Science.gov (United States)

    Weeks, Phillip A; Teng, Yang; Wu, Lei; Sun, Mary; Yang, Zhen; Chow, Diana S-L

    2014-01-01

    An infusion of epinephrine combined with calcium chloride has been used historically as an intravenous inotropic solution to support critically ill heart failure patients with severe cardiogenic shock. There is no reliable data on the stability of this solution beyond three hours. This study was conducted to evaluate the chemical and physical compatibility of epinephrine (0.032 mg/mL) combined with calcium chloride (4 mg/mL) in a solution for intravenous administration up to 26 hours at room temperature. The chemical stability of epinephrine was monitored by measuring epinephrine concentrations using high-performance liquid chromatography. The physical compatibility of the mixture was determined by measuring spectrophotometric absorbance between 400 to 700 nm. Absorbance greater than 0.010 AU was considered an indicator of the presence of precipitation. The results showed epinephrine with calcium chloride was stable together in normal saline up to 26 hours at room temperature, irrespective of exposure to light. The absorbance of epinephrine throughout the study was less than 0.010 AU, indicating no significant precipitation. Conclusions indicate that epinephrine (0.032 mg/mL) combined with calcium chloride (4 mg/mL) in normal saline at room temperature is acceptably stable up to 26 hours for intravenous administration.

  4. Effect of adsorbents and chemical treatments on the removal of strontium from aqueous solutions

    International Nuclear Information System (INIS)

    Ahmadpour, A.; Zabihi, M.; Tahmasbi, M.; Bastami, T. Rohani

    2010-01-01

    In the present investigation, three different solid wastes namely almond green hull, eggplant hull, and moss were initially treated and used as adsorbents for the adsorption of strontium ion from aqueous solutions. Adsorbent types and chemical treatments are proved to have effective roles on the adsorption of Sr(II) ion. Among the three adsorbents, almond green hull demonstrated strong affinity toward strontium ion in different solutions. The effectiveness of this new adsorbent was studied in batch adsorption mode under a variety of experimental conditions such as: different chemical treatments, various amounts of adsorbent, and initial metal-ion concentration. The optimum doses of adsorbent for the maximum Sr(II) adsorption were found to be 0.2 and 0.3 g for 45 and 102 mg L -1 solutions, respectively. High Sr(II) adsorption efficiencies were achieved only in the first 3 min of adsorbent's contact time. The kinetics of Sr(II) adsorption on almond green hull was also examined and it was observed that it follows the pseudo second-order behavior. Both Langmuir and Freundlich models well predicted the experimental adsorption isotherm data. The maximum adsorption capacity on almond green hull was found to be 116.3 mg g -1 . The present study also confirmed that these low cost agriculture byproducts could be used as efficient adsorbents for the removal of strontium from wastewater streams.

  5. Compactness and robustness: Applications in the solution of integral equations for chemical kinetics and electromagnetic scattering

    Science.gov (United States)

    Zhou, Yajun

    This thesis employs the topological concept of compactness to deduce robust solutions to two integral equations arising from chemistry and physics: the inverse Laplace problem in chemical kinetics and the vector wave scattering problem in dielectric optics. The inverse Laplace problem occurs in the quantitative understanding of biological processes that exhibit complex kinetic behavior: different subpopulations of transition events from the "reactant" state to the "product" state follow distinct reaction rate constants, which results in a weighted superposition of exponential decay modes. Reconstruction of the rate constant distribution from kinetic data is often critical for mechanistic understandings of chemical reactions related to biological macromolecules. We devise a "phase function approach" to recover the probability distribution of rate constants from decay data in the time domain. The robustness (numerical stability) of this reconstruction algorithm builds upon the continuity of the transformations connecting the relevant function spaces that are compact metric spaces. The robust "phase function approach" not only is useful for the analysis of heterogeneous subpopulations of exponential decays within a single transition step, but also is generalizable to the kinetic analysis of complex chemical reactions that involve multiple intermediate steps. A quantitative characterization of the light scattering is central to many meteoro-logical, optical, and medical applications. We give a rigorous treatment to electromagnetic scattering on arbitrarily shaped dielectric media via the Born equation: an integral equation with a strongly singular convolution kernel that corresponds to a non-compact Green operator. By constructing a quadratic polynomial of the Green operator that cancels out the kernel singularity and satisfies the compactness criterion, we reveal the universality of a real resonance mode in dielectric optics. Meanwhile, exploiting the properties of

  6. Physico-chemical stability of eribulin mesylate containing concentrate and ready-to-administer solutions.

    Science.gov (United States)

    Spindeldreier, Kirsten; Thiesen, Judith; Lipp, Hans-Peter; Krämer, Irene

    2014-06-01

    The aim of this study was to determine the stability of commercially available eribulin mesylate containing injection solution as well as diluted ready-to-administer solutions stored under refrigeration or at room temperature. Stability was studied by a novel developed stability-indicating reversed-phase high-performance liquid chromatography (RP-HPLC) assay with ultraviolet detection (detection wavelength 200 nm). Triplicate test solutions of eribulin mesylate containing injection concentrate (0.5 mg/mL) and with 0.9% sodium chloride solution diluted ready-to-administer preparations (0.205 mg/mL eribulin mesylate in polypropylene (PP) syringes, 0.020 mg/mL eribulin mesylate in polypropylene/polyethylene (PE) bags) were stored protected from light either at room temperature (25) or under refrigeration (2-8). Samples were withdrawn on day 0 (initial), 1, 3, 5, 7, 14, 21 and 28 of storage and assayed. Physical stability was determined by measuring the pH value once a week and checking for visible precipitations or colour changes. The stability tests revealed that concentrations of eribulin mesylate remained unchanged over a period of 28 days irrespective of concentration, container material or storage temperature. Neither colour changes nor visible particles have been observed. The pH value varied slightly over time but remained in the stability favourable range of 5-9. Eribulin mesylate injection (0.5 mg/mL) is physico-chemically stable over a period of 28 days after first puncture of the vial. After dilution with 0.9% NaCl vehicle solution, ready-to-administer eribulin mesylate injection solutions (0.205 mg/mL in PP syringe) and infusion solutions (0.02 mg/mL in prefilled PP/PE bags) are physico-chemically stable for a period of at least four weeks either refrigerated or stored at room temperature. For microbiological reasons storage under refrigeration is recommended.

  7. Atmospheric-pressure electric discharge as an instrument of chemical activation of water solutions

    Science.gov (United States)

    Rybkin, V. V.; Shutov, D. A.

    2017-11-01

    Results of experimental studies and numerical simulations of physicochemical characteristics of plasmas generated in different types of atmospheric-pressure discharges (pulsed streamer corona, gliding electric arc, dielectric barrier discharge, glow-discharge electrolysis, diaphragmatic discharge, and dc glow discharge) used to initiate various chemical processes in water solutions are analyzed. Typical reactor designs are considered. Data on the power supply characteristics, plasma electron parameters, gas temperatures, and densities of active particles in different types of discharges excited in different gases and their dependences on the external parameters of discharges are presented. The chemical composition of active particles formed in water is described. Possible mechanisms of production and loss of plasma particles are discussed.

  8. Determination of Gibbs energies of formation in aqueous solution using chemical engineering tools.

    Science.gov (United States)

    Toure, Oumar; Dussap, Claude-Gilles

    2016-08-01

    Standard Gibbs energies of formation are of primary importance in the field of biothermodynamics. In the absence of any directly measured values, thermodynamic calculations are required to determine the missing data. For several biochemical species, this study shows that the knowledge of the standard Gibbs energy of formation of the pure compounds (in the gaseous, solid or liquid states) enables to determine the corresponding standard Gibbs energies of formation in aqueous solutions. To do so, using chemical engineering tools (thermodynamic tables and a model enabling to predict activity coefficients, solvation Gibbs energies and pKa data), it becomes possible to determine the partial chemical potential of neutral and charged components in real metabolic conditions, even in concentrated mixtures. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Chemical concentration of a new natural spontaneously fissionable nuclide from solutions with low salt background

    International Nuclear Information System (INIS)

    Korotkin, Yu.S.; Ter-Akop'yan, G.M.; Popeko, A.G.; Drobina, T.P.; Zhuravleva, E.L.

    1982-01-01

    The results of experiments on further concentration of a new natural spontaneously fissionable nuclide, the concentrates of which form the Cheleken geothermal brines have been obtained, are presented. The conclusions are drown about the chemical nature of a new spontaneously fissionable nuclide. It is a chalcophile element which copreipitates with sulphides of copper, lead, arsenic and mercury from weakly acid solutions. The behaviour of the new nuclide in sulphide systems in many respects is similar to the behaviour of polonium, astatine and probably of bismuth. The most probable stable valence of the new nuclide varies from +1 up to +3. The data available on the chemical behaviour of the new nuclide as well as the analysis over contamination by spontaneously fissionable isotopes permit to state that the new natural spontaneously fissionable nuclide does not relate to the known isotopes

  10. Chemical aspects of the precise and accurate determination of uranium and plutonium from nuclear fuel solutions

    International Nuclear Information System (INIS)

    Heinonen, O.J.

    1981-01-01

    A method for the simultaneous or separate determination of uranium and plutonium has been developed. The method is based on the sorption of uranium and plutonium as their chloro complexes on Dowex 1x10 column. When separate uranium and plutonium fractions are desired, plutonium ions are reduced to Pu (III) and eluted, after which the uranium ions are eluted with dilute HCl. Simultaneous stripping of a mass ratio U/Pu approximately 1 fraction for mass spectrometric measurements is achieved by proper choice of eluant HC1 concentration. Special attention was paid to the obtaining of americium free plutonium fractions. The distribution coefficient measurements showed that at 12.5-M HCl at least 30 % of americium ions formed anionic chloro complexes. The chemical aspects of isotopic fractionation in a multiple filament thermal ionization source were also investigated. Samples of uranium were loaded as nitrates, chlorides, and sulphates and the dependence of the measured uranium isotopic ratios on the chemical form of the loading solution as well as on the filament material was studied. Likewise the dependence of the formation of uranium and its oxide ions on various chemical and instrumental conditions was investigated using tungsten and rhenium filaments. Systematic errors arising from the chemical conditions are compared with errors arising from the automatic evaluation of of spectra. (author)

  11. Chemical solution deposition of YBCO thin film by different polymer additives

    International Nuclear Information System (INIS)

    Wang, W.T.; Li, G.; Pu, M.H.; Sun, R.P.; Zhou, H.M.; Zhang, Y.; Zhang, H.; Yang, Y.; Cheng, C.H.; Zhao, Y.

    2008-01-01

    A polymer-assisted chemical solution deposition approach has been proposed for the preparation of YBCO thin film. Different additives like PVB (polyvinyl butyral), PEG (polyethylene glycol) and PVP (polyvinylpyrrolidone) have been used to adjust the final viscosity of the precursor solution and thus the film formation. In this fluorine-free approach, YBCO has been deposited on single crystal substrates with metal acetates being starting materials. Biaxially textured YBCO thin films have been obtained. However, different additives lead to different microstructure. Dense, smooth and crack-free YBCO film prepared with PVB as additive yields sharp superconducting transition around T c = 90 K as well as high J c (0 T, 77 K) over 3 MA/cm 2

  12. Radiolytic effect on the chemical state of iodine in aqueous solution

    International Nuclear Information System (INIS)

    Shiraishi, H.; Kimiya, T.; Ohmae, M.; Ishigure, K.

    1988-01-01

    The oxidation state of iodine dissolved in an aqueous solution is easily changed in the presence of radiation field. Hence, it is essential to take the radiolytic effect into account when one is to estimate chemical forms of iodine after being released into the containment under an LOCA condition. This paper summarizes results of γ-radiolysis experiments on aqueous solutions containing iodine species, which have been carried out to extend the previously reported study on the same system. Variation in iodine product distribution with time has been examined as before, utilizing a flow system under irradiation. Attention has been paid to the effect of oxygen, to that of an initial oxidation state of iodine, and to the influence of temperature. Some kinetic analysis on the system was also undertaken

  13. Chemical solution deposition of YBCO thin film by different polymer additives

    Energy Technology Data Exchange (ETDEWEB)

    Wang, W.T.; Li, G.; Pu, M.H.; Sun, R.P.; Zhou, H.M.; Zhang, Y. [Key Laboratory of Magnetic Levitation Technologies and Maglev Trains, Ministry of Education of China, Superconductivity R and D Center (SRDC), Mail Stop 165, Southwest Jiaotong University, Chengdu 610031 (China); Zhang, H. [Department of Physics, Peking University, Beijing 100871 (China); Yang, Y. [Key Laboratory of Magnetic Levitation Technologies and Maglev Trains, Ministry of Education of China, Superconductivity R and D Center (SRDC), Mail Stop 165, Southwest Jiaotong University, Chengdu 610031 (China); Cheng, C.H. [Key Laboratory of Magnetic Levitation Technologies and Maglev Trains, Ministry of Education of China, Superconductivity R and D Center (SRDC), Mail Stop 165, Southwest Jiaotong University, Chengdu 610031 (China); School of Materials Science and Engineering, University of New South Wale, Sydney, 2052 NSW (Australia); Zhao, Y. [Key Laboratory of Magnetic Levitation Technologies and Maglev Trains, Ministry of Education of China, Superconductivity R and D Center (SRDC), Mail Stop 165, Southwest Jiaotong University, Chengdu 610031 (China); School of Materials Science and Engineering, University of New South Wale, Sydney, 2052 NSW (Australia)], E-mail: yzhao@swjtu.edu.cn

    2008-09-15

    A polymer-assisted chemical solution deposition approach has been proposed for the preparation of YBCO thin film. Different additives like PVB (polyvinyl butyral), PEG (polyethylene glycol) and PVP (polyvinylpyrrolidone) have been used to adjust the final viscosity of the precursor solution and thus the film formation. In this fluorine-free approach, YBCO has been deposited on single crystal substrates with metal acetates being starting materials. Biaxially textured YBCO thin films have been obtained. However, different additives lead to different microstructure. Dense, smooth and crack-free YBCO film prepared with PVB as additive yields sharp superconducting transition around T{sub c} = 90 K as well as high J{sub c} (0 T, 77 K) over 3 MA/cm{sup 2}.

  14. Textured indium tin oxide thin films by chemical solution deposition and rapid thermal processing

    International Nuclear Information System (INIS)

    Mottern, Matthew L.; Tyholdt, Frode; Ulyashin, Alexander; Helvoort, Antonius T.J. van; Verweij, Henk; Bredesen, Rune

    2007-01-01

    The microstructure of state-of-the-art chemical solution deposited indium tin oxide thin films typically consists of small randomly oriented grains, high porosity and poor homogeneity. The present study demonstrates how the thin film microstructure can be improved significantly by tailoring the precursor solutions and deposition conditions to be kinetically and thermodynamically favorable for generation of homogeneous textured thin films. This is explained by the occurrence of a single heterogeneous nucleation mechanism. The as-deposited thin films, crystallized at 800 deg. C, have a high apparent density, based on a refractive index of ∼ 1.98 determined by single wavelength ellipsometry at 633 nm. The microstructure of the films consists of columnar grains with preferred orientation as determined by X-ray diffraction and transmission electron microscopy. The resistivity, measured by the four point probe method, is ∼ 2 x 10 -3 Ω cm prior to post-deposition treatments

  15. Chemical activation of tea waste and use for the removal of chromium (Vi) from aqueous solution

    International Nuclear Information System (INIS)

    Qureshi, K.; Bhatti, I.; Ansari, A.K.

    2009-01-01

    Tea waste is the residue left after the preparation of tea. At present the tea waste is regarded as a waste product having no use. In this study, tea waste is converted into an adsorbent. Tea waste is chemically activated with phosphoric acid at low temperature 450 degree C. This activated carbon is then utilized as an adsorbent for the removal of Chromium (VI) from aqueous solution. The various sorption parameters i.e pH, sorbent dose sorbate concentration, shaking time and shaking speed are first optimized. 75% of chromium from aqueous solution is effectively removed at pH 2. The best optimum conditions were obtained when 1 gm of sorbent was agitated at 100 rpm with 60 mg/l of sorbate for 50 minutes. Better results were obtained when low concentrations of sorbates were used. Hence tea waste could also be successfully used for the sorption of Chromium (VI), from industrial waste water. (author)

  16. Electronic tongue - an array of non-specific chemical sensors - for analysis of radioactive solutions

    International Nuclear Information System (INIS)

    Legin, A.; Rudnitskaya, A.; Babain, V.

    2006-01-01

    Multisensor systems, combining chemical sensor arrays with multivariate data processing engines (electronic tongue) rapidly and successfully developing in the last years are capable of simultaneous quantitative analysis of several species, e.g. metals, in complex real solutions. The expansion of the metals (metal ions) and species to be detected in radioactive waste requires permanent enhancement of sensing materials and sensors, with seriously different properties from those known earlier. A prospective direction of R and D of novel sensing materials is exploitation of radiochemical extraction systems and application of extraction substances as active components of new sensors. The sensors based on bidentate phosphorous organic compounds and their combinations with chlorinated cobalt dicarbollide displayed high sensitivity and selectivity to rare-earth metal ions La 3+ , Pr 3+ , Nd 3+ , Eu 3+ . The results indicated good promise for the development of novel analytical tools for detection of multivalent metal cations in different media, particularly in corrosive solutions such as radioactive wastes and solutions derived from spent nuclear fuel. The sensors and sensor arrays made on their basis can play an important role in the development of 'electronic tongue' systems for rapid analytical determinations of different components in complex radioactive solutions

  17. Chemical analysis of bleach and hydroxide-based solutions after decontamination of the chemical warfare agent O-ethyl S-2-diisopropylaminoethyl methylphosphonothiolate (VX).

    Science.gov (United States)

    Hopkins, F B; Gravett, M R; Self, A J; Wang, M; Chua, Hoe-Chee; Hoe-Chee, C; Lee, H S Nancy; Sim, N Lee Hoi; Jones, J T A; Timperley, C M; Riches, J R

    2014-08-01

    Detailed chemical analysis of solutions used to decontaminate chemical warfare agents can be used to support verification and forensic attribution. Decontamination solutions are amongst the most difficult matrices for chemical analysis because of their corrosive and potentially emulsion-based nature. Consequently, there are relatively few publications that report their detailed chemical analysis. This paper describes the application of modern analytical techniques to the analysis of decontamination solutions following decontamination of the chemical warfare agent O-ethyl S-2-diisopropylaminoethyl methylphosphonothiolate (VX). We confirm the formation of N,N-diisopropylformamide and N,N-diisopropylamine following decontamination of VX with hypochlorite-based solution, whereas they were not detected in extracts of hydroxide-based decontamination solutions by nuclear magnetic resonance (NMR) spectroscopy or gas chromatography-mass spectrometry. We report the electron ionisation and chemical ionisation mass spectroscopic details, retention indices, and NMR spectra of N,N-diisopropylformamide and N,N-diisopropylamine, as well as analytical methods suitable for their analysis and identification in solvent extracts and decontamination residues.

  18. Say goodbye to coffee stains

    NARCIS (Netherlands)

    Eral, Burak; van den Ende, Henricus T.M.; Mugele, Friedrich Gunther

    2012-01-01

    Discussing ideas over a mug of coffee or tea is the lifeblood of science, but have you ever thought about the stains that can be inadvertently left behind? H Burak Eral, Dirk van den Ende and Frieder Mugele explain how these stains, which can be a major annoyance in some biology techniques, can be

  19. Study on CexLa1-xO2 Buffer Layer used in Coated Conductors by Chemical Solution Method

    DEFF Research Database (Denmark)

    Zhao, Yue; Suo, Hongli; Grivel, Jean-Claude

    2009-01-01

    Developing multi-functional single buffer layer is one of the most important challenges for simplification of coated conductors configuration. Ladoped CeO2 films were prepared by chemical solution method. And surface morphology and texture quality of the La-doped CeO2 films were investigated...... method. It suggects that Ce0.9La0.1O2 film prepared by chemical solution route have a promising prospect for the simplification of coated conductors configuration....

  20. Effectiveness of clean-up procedures on stain susceptibility of different orthodontic adhesives

    Directory of Open Access Journals (Sweden)

    Swati Pundlik Mane

    2014-01-01

    Conclusion: Chemical-cure adhesive showed higher stain susceptibility than light-cure adhesive in all clean-up procedures. Both adhesives would show less stain susceptibility with polishing step with rubber cup and pumice.

  1. Chemical bonding and the equilibrium composition of Grignard reagents in ethereal solutions.

    Science.gov (United States)

    Henriques, André M; Barbosa, André G H

    2011-11-10

    A thorough analysis of the electronic structure and thermodynamic aspects of Grignard reagents and its associated equilibrium composition in ethereal solutions is performed. Considering methylmagnesium halides containing fluorine, chlorine, and bromine, we studied the neutral, charged, and radical species associated with their chemical equilibrium in solution. The ethereal solvents considered, tetrahydrofuran (THF) and ethyl ether (Et(2)O), were modeled using the polarizable continuum model (PCM) and also by explicit coordination to the Mg atoms in a cluster. The chemical bonding of the species that constitute the Grignard reagent is analyzed in detail with generalized valence bond (GVB) wave functions. Equilibrium constants were calculated with the DFT/M06 functional and GVB wave functions, yielding similar results. According to our calculations and existing kinetic and electrochemical evidence, the species R(•), R(-), (•)MgX, and RMgX(2)(-) must be present in low concentration in the equilibrium. We conclude that depending on the halogen, a different route must be followed to produce the relevant equilibrium species in each case. Chloride and bromide must preferably follow a "radical-based" pathway, and fluoride must follow a "carbanionic-based" pathway. These different mechanisms are contrasted against the available experimental results and are proven to be consistent with the existing thermodynamic data on the Grignard reagent equilibria.

  2. A decontamination system for chemical weapons agents using a liquid solution on a solid sorbent

    Energy Technology Data Exchange (ETDEWEB)

    Waysbort, Daniel [Israel Institute for Biological Research, PO Box 19, Ness-Ziona 74100 (Israel); McGarvey, David J. [R and T Directorate, Edgewood Chemical and Biological Center (ECBC), Aberdeen Proving Ground-Edgewood Area, MD 21010 (United States)], E-mail: david.mcgarvey@us.army.mil; Creasy, William R.; Morrissey, Kevin M.; Hendrickson, David M. [SAIC, P.O. Box 68, Gunpowder Branch, Aberdeen Proving Ground, MD 21010 (United States); Durst, H. Dupont [R and T Directorate, Edgewood Chemical and Biological Center (ECBC), Aberdeen Proving Ground-Edgewood Area, MD 21010 (United States)

    2009-01-30

    A decontamination system for chemical warfare agents was developed and tested that combines a liquid decontamination reagent solution with solid sorbent particles. The components have fewer safety and environmental concerns than traditional chlorine bleach-based products or highly caustic solutions. The liquid solution, based on Decon Green{sup TM}, has hydrogen peroxide and a carbonate buffer as active ingredients. The best solid sorbents were found to be a copolymer of ethylene glycol dimethacrylate and n-lauryl methacrylate (Polytrap 6603 Adsorber); or an allyl methacrylate cross-linked polymer (Poly-Pore E200 Adsorber). These solids are human and environmentally friendly and are commonly used in cosmetics. The decontaminant system was tested for reactivity with pinacolyl methylphosphonofluoridate (Soman, GD), bis(2-chloroethyl)sulfide (Mustard, HD), and S-(2-diisopropylaminoethyl) O-ethyl methylphosphonothioate (VX) by using NMR Spectroscopy. Molybdate ion (MoO{sub 4}{sup -2}) was added to the decontaminant to catalyze the oxidation of HD. The molybdate ion provided a color change from pink to white when the oxidizing capacity of the system was exhausted. The decontaminant was effective for ratios of agent to decontaminant of up to 1:50 for VX (t{sub 1/2} {<=} 4 min), 1:10 for HD (t{sub 1/2} < 2 min with molybdate), and 1:10 for GD (t{sub 1/2} < 2 min). The vapor concentrations of GD above the dry sorbent and the sorbent with decontamination solution were measured to show that the sorbent decreased the vapor concentration of GD. The E200 sorbent had the additional advantage of absorbing aqueous decontamination solution without the addition of an organic co-solvent such as isopropanol, but the rate depended strongly on mixing for HD.

  3. A decontamination system for chemical weapons agents using a liquid solution on a solid sorbent

    International Nuclear Information System (INIS)

    Waysbort, Daniel; McGarvey, David J.; Creasy, William R.; Morrissey, Kevin M.; Hendrickson, David M.; Durst, H. Dupont

    2009-01-01

    A decontamination system for chemical warfare agents was developed and tested that combines a liquid decontamination reagent solution with solid sorbent particles. The components have fewer safety and environmental concerns than traditional chlorine bleach-based products or highly caustic solutions. The liquid solution, based on Decon Green TM , has hydrogen peroxide and a carbonate buffer as active ingredients. The best solid sorbents were found to be a copolymer of ethylene glycol dimethacrylate and n-lauryl methacrylate (Polytrap 6603 Adsorber); or an allyl methacrylate cross-linked polymer (Poly-Pore E200 Adsorber). These solids are human and environmentally friendly and are commonly used in cosmetics. The decontaminant system was tested for reactivity with pinacolyl methylphosphonofluoridate (Soman, GD), bis(2-chloroethyl)sulfide (Mustard, HD), and S-(2-diisopropylaminoethyl) O-ethyl methylphosphonothioate (VX) by using NMR Spectroscopy. Molybdate ion (MoO 4 -2 ) was added to the decontaminant to catalyze the oxidation of HD. The molybdate ion provided a color change from pink to white when the oxidizing capacity of the system was exhausted. The decontaminant was effective for ratios of agent to decontaminant of up to 1:50 for VX (t 1/2 ≤ 4 min), 1:10 for HD (t 1/2 1/2 < 2 min). The vapor concentrations of GD above the dry sorbent and the sorbent with decontamination solution were measured to show that the sorbent decreased the vapor concentration of GD. The E200 sorbent had the additional advantage of absorbing aqueous decontamination solution without the addition of an organic co-solvent such as isopropanol, but the rate depended strongly on mixing for HD

  4. Colour stabilities of three types of orthodontic clear aligners exposed to staining agents.

    Science.gov (United States)

    Liu, Chen-Lu; Sun, Wen-Tian; Liao, Wen; Lu, Wen-Xin; Li, Qi-Wen; Jeong, Yunho; Liu, Jun; Zhao, Zhi-He

    2016-12-16

    The aim of this study was to evaluate and compare the colour stabilities of three types of orthodontic clear aligners exposed to staining agents in vitro. Sixty clear orthodontic aligners produced by three manufacturers (Invisalign, Angelalign, and Smartee) were immersed in three staining solutions (coffee, black tea, and red wine) and one control solution (distilled water). After 12-h and 7-day immersions, the aligners were washed in an ultrasonic cleaner and measured with a colourimeter. The colour changes (ΔE*) were calculated on the basis of the Commission Internationale de I'Eclairage L*a*b* colour system (CIE L*a*b*), and the results were then converted into National Bureau of Standards (NBS) units. Fourier transformation infrared (FT-IR) spectroscopy and scanning electron microscopy (SEM) were conducted to observe the molecular and morphologic alterations to the aligner surfaces, respectively. The three types of aligners exhibited slight colour changes after 12 h of staining, with the exception of the Invisalign aligners stained with coffee. The Invisalign aligners exhibited significantly higher ΔE* values (ranging from 0.30 to 27.81) than those of the Angelalign and Smartee aligners (ΔE* values ranging from 0.33 to 1.89 and 0.32 to 1.61, respectively, Paligners did not exhibit significant chemical differences before and after the immersions. The SEM results revealed different surface alterations to the three types of aligner materials after the 7-day staining. The three types of aesthetic orthodontic appliances exhibited colour stability after the 12-h immersion, with the exception of the Invisalign aligners stained by coffee. The Invisalign aligners were more prone than the Angelalign and Smartee aligners to pigmentation. Aligner materials may be improved by considering aesthetic colour stability properties.

  5. Improved Nissl method to stain formaldehyde or glutaraldehyde-fixed material.

    Science.gov (United States)

    Böck, P

    1979-05-15

    Nissl staining of paraffin sections from formaldehyde- or glutaraldehyde-fixed specimens is significantly intensified when sections are kept in a 50% (w/v) aqueous solution of potassium metabisulfite before being stained by a conventional Nissl method.

  6. Chemical degradation of 3H-labeled substance P in tris buffer solution

    International Nuclear Information System (INIS)

    Higa, T.; Desiderio, D.M.

    1988-01-01

    Substance P (SP) is an important neuropeptide that has been implicated in several physiological processes, and it is necessary to devise an analytical procedure to measure endogenous SP with a combination of high sensitivity and maximum molecular specificity. However, the unique chemical nature of SP (polarity, chemical stability, ease of oxidation, peptide bond lability) plays a significant role in its analysis, such as in receptor assays, immunoassays, chromatography, and mass spectrometry. In this study, we evaluated in polypropylene and glass assay tubes the effects on the recovery and stability of tritiated SP ([3H]SP) of several pertinent experimental parameters such as buffer, pH, multiple freeze-thaw cycles, and incubation temperature and time. Bovine serum albumin (BSA) effectively reduced the absorption of [3H]SP to polypropylene and glass tube surfaces. Following multiple (6X) freeze-thaw cycles of solutions in BSA-precoated tubes, the recovery of radioactive [3H]SP remained high (greater than 75%) after the last cycle, whereas recovery was minimal in uncoated or siliconized glass tubes. A high level of radioactivity recovery was maintained for 14 days of storage of [3H]SP in triethylamine formate (TEAF) solution in BSA-precoated tubes at 4 and -20 degrees C, but decreased at 37 degrees C to less than 80% in only 3 h. Following storage in Tris-HCl (pH 7.4) buffer, a combination of HPLC and mass spectrometric analyses revealed that a significant amount of peptide bond cleavage occurred to produce the two peptides ArgProLys (RPK) and ArgProLysProGlnGln (RPKPQQ), with only a small amount of remaining intact SP. That decomposition was not observed in triethylamine formate TEAF (pH 3.14) buffer solutions

  7. A procedure to create isoconcentration surfaces in low-chemical-partitioning, high-solute alloys

    International Nuclear Information System (INIS)

    Hornbuckle, B.C.; Kapoor, M.; Thompson, G.B.

    2015-01-01

    A proximity histogram or proxigram is the prevailing technique of calculating 3D composition profiles of a second phase in atom probe tomography. The second phase in the reconstruction is delineated by creating an isoconcentration surface, i.e. the precipitate–matrix interface. The 3D composition profile is then calculated with respect to this user-defined isoconcentration surface. Hence, the selection of the correct isoconcentration surface is critical. In general, the preliminary selection of an isoconcentration value is guided by the visual observation of a chemically partitioned second phase. However, in low-chemical -partitioning systems, such a visual guide is absent. The lack of a priori composition information of the precipitate phase may further confound the issue. This paper presents a methodology of selecting an appropriate elemental species and subsequently obtaining an isoconcentration value to create an accurate isoconcentration surface that will act as the precipitate–matrix interface. We use the H-phase precipitate in the Ni–Ti–Hf shape memory alloy as our case study to illustrate the procedure. - Highlights: • A procedure for creating accurate isoconcentration surface for low-chemical-partitioning, high-solute alloys. • Determine the appropriate element to create the isosconcentration surface. • Subsequently identify the accurate isoconcentration value to create an isoconcentration surface.

  8. A Pilot Chemical and Physical Stability Study of Extemporaneously Compounded Levetiracetam Intravenous Solution.

    Science.gov (United States)

    Raphael, Chenzira D; Zhao, Fang; Hughes, Susan E; Juba, Katherine M

    2015-01-01

    Levetiracetam is a commonly used antiepileptic medication for tumor-related epilepsy. However, the 100 mL intravenous (IV) infusion volume can be burdensome to imminently dying hospice patients. A reduced infusion volume would improve patient tolerability. The purpose of this study was to evaluate the stability of 1000 mg/25 mL (40 mg/mL) levetiracetam IV solution in sodium chloride 0.9%. We prepared levetiracetam 40 mg/mL IV solution and added it to polyvinyl chloride (PVC) bags, polyolefin bags, and polypropylene syringes. Triplicate samples of each product were stored at refrigeration (2-8°C) and analyzed on days 0, 1, 4, 7, and 14. Samples were subjected to visual inspection, pH measurement, and stability-indicating high-performance liquid chromatography (HPLC) analysis. Over the 2-week storage period, there was no significant change in visual appearance or pH for any of the stability samples. The HPLC results confirmed that all stability samples retained 94.2-101.3% of initial drug concentration and no degradation products or leachable material from the packaging materials were observed. We conclude that levetiracetam 1000 mg/25 mL IV solution in sodium chloride 0.9% is physically and chemically stable for up to 14 days under refrigeration in polypropylene syringes, PVC bags, and polyolefin bags.

  9. Comparison of Nonequilibrium Solution Algorithms Applied to Chemically Stiff Hypersonic Flows

    Science.gov (United States)

    Palmer, Grant; Venkatapathy, Ethiraj

    1995-01-01

    Three solution algorithms, explicit under-relaxation, point implicit, and lower-upper symmetric Gauss-Seidel, are used to compute nonequilibrium flow around the Apollo 4 return capsule at the 62-km altitude point in its descent trajectory. By varying the Mach number, the efficiency and robustness of the solution algorithms were tested for different levels of chemical stiffness.The performance of the solution algorithms degraded as the Mach number and stiffness of the flow increased. At Mach 15 and 30, the lower-upper symmetric Gauss-Seidel method produces an eight order of magnitude drop in the energy residual in one-third to one-half the Cray C-90 computer time as compared to the point implicit and explicit under-relaxation methods. The explicit under-relaxation algorithm experienced convergence difficulties at Mach 30 and above. At Mach 40 the performance of the lower-upper symmetric Gauss-Seidel algorithm deteriorates to the point that it is out performed by the point implicit method. The effects of the viscous terms are investigated. Grid dependency questions are explored.

  10. Numerical solution of chemically reactive non-Newtonian fluid flow: Dual stratification

    Science.gov (United States)

    Rehman, Khalil Ur; Malik, M. Y.; Khan, Abid Ali; Zehra, Iffat; Zahri, Mostafa; Tahir, M.

    2017-12-01

    We have found that only a few attempts are available in the literature relatively to the tangent hyperbolic fluid flow induced by stretching cylindrical surfaces. In particular, temperature and concentration stratification effects have not been investigated until now with respect to the tangent hyperbolic fluid model. Therefore, we have considered the tangent hyperbolic fluid flow induced by an acutely inclined cylindrical surface in the presence of both temperature and concentration stratification effects. To be more specific, the fluid flow is attained with the no slip condition, which implies that the bulk motion of the fluid particles is the same as the stretching velocity of a cylindrical surface. Additionally, the flow field situation is manifested with heat generation, mixed convection and chemical reaction effects. The flow partial differential equations give a complete description of the present problem. Therefore, to trace out the solution, a set of suitable transformations is introduced to convert these equations into ordinary differential equations. In addition, a self-coded computational algorithm is executed to inspect the numerical solution of these reduced equations. The effect logs of the involved parameters are provided graphically. Furthermore, the variations of the physical quantities are examined and given with the aid of tables. It is observed that the fluid temperature is a decreasing function of the thermal stratification parameter and a similar trend is noticed for the concentration via the solutal stratification parameter.

  11. Convergence to equilibrium of renormalised solutions to nonlinear chemical reaction–diffusion systems

    Science.gov (United States)

    Fellner, Klemens; Tang, Bao Quoc

    2018-06-01

    The convergence to equilibrium for renormalised solutions to nonlinear reaction-diffusion systems is studied. The considered reaction-diffusion systems arise from chemical reaction networks with mass action kinetics and satisfy the complex balanced condition. By applying the so-called entropy method, we show that if the system does not have boundary equilibria, i.e. equilibrium states lying on the boundary of R_+^N, then any renormalised solution converges exponentially to the complex balanced equilibrium with a rate, which can be computed explicitly up to a finite-dimensional inequality. This inequality is proven via a contradiction argument and thus not explicitly. An explicit method of proof, however, is provided for a specific application modelling a reversible enzyme reaction by exploiting the specific structure of the conservation laws. Our approach is also useful to study the trend to equilibrium for systems possessing boundary equilibria. More precisely, to show the convergence to equilibrium for systems with boundary equilibria, we establish a sufficient condition in terms of a modified finite-dimensional inequality along trajectories of the system. By assuming this condition, which roughly means that the system produces too much entropy to stay close to a boundary equilibrium for infinite time, the entropy method shows exponential convergence to equilibrium for renormalised solutions to complex balanced systems with boundary equilibria.

  12. Comparison of 30% salicylic acid with jessner's solution for superficial chemical peeling in epidermal melasma

    International Nuclear Information System (INIS)

    Ejaz, A.; Raza, N.; Iftikhar, N.; Muzzafar, F.

    2008-01-01

    To compare the efficacy and safety of Jessner's solution with 30% salicylic acid as superficial chemical peeling agents in treating epidermal melasma in Asian skin. Sixty consenting patients with epidermal melasma were randomly divided into two groups. Group A was treated with Jessner's solution and Group B with 30% salicylic acid. Baseline Melasma Area Severity Index (MASI) score was noted and peeling started at 2-weekly intervals. Sunscreen in morning and moisturizer at night were prescribed in all patients. MASI score and adverse effects were recorded biweekly. Treatment was stopped at 12 weeks and patients were followed-up at 4 weekly intervals for further 12 weeks. Final MASI score and adverse effects were noted at the end of follow-up period. Mean MASI scores were compared using paired sample t-test and one-way ANOVA. Difference in baseline, treatment end and follow-up end MASI scores was not statistically significant between the two groups (p=0.54, 0.26, and 0.55 respectively). On the other hand, within group analysis of difference between pre and posttreatment MASI score was highly significant in both groups (p < 0.0001). Adverse effects were mild and comparable in both groups. Jessner's solution and 30% salicylic acid are equally effective and safe peeling agents for use in epidermal melasma in Asian skin. (author)

  13. Physical and chemical stability of reconstituted and diluted dexrazoxane infusion solutions.

    Science.gov (United States)

    Zhang, Yan-Ping; Myers, Alan L; Trinh, Van A; Kawedia, Jitesh D; Kramer, Mark A; Benjamin, Robert S; Tran, Hai T

    2014-02-01

    Dexrazoxane is used clinically to prevent anthracycline-associated cardiotoxicity. Hydrolysis of dexrazoxane prior to reaching the cardiac membranes severely hampers its mode of action; therefore, degradation during the preparation and administration of intravenous dexrazoxane admixtures demands special attention. Moreover, the ongoing national shortage of one dexrazoxane formulation in the United States has forced pharmacies to dispense other commercially available dexrazoxane products. However, the manufacturers' limited stability data restrict the flexibility of dexrazoxane usage in clinical practice. The aims of this study are to determine the physical and chemical stability of reconstituted and diluted solutions of two commercially available dexrazoxane formulations. The stability of two dexrazoxane products, brand and generic name, in reconstituted and intravenous solutions stored at room temperature without light protection in polyvinyl chloride bags was determined. The concentrations of dexrazoxane were measured at predetermined time points up to 24 h using a validated reversed phase high-performance liquid chromatography with ultraviolet detection assay. Brand (B-) and generic (G-) dexrazoxane products, reconstituted in either sterile water or 0.167 M sodium lactate (final concentration of 10 mg/mL), were found stable for at least to 8 h. Infusion solutions of B-dexrazoxane, prepared according to each manufacturer's directions, were stable for at least 24 h and 8 h at 1 mg/mL and 3 mg/mL, respectively. Infusion solutions of G-dexrazoxane, prepared in either 5% dextrose or 0.9% sodium chloride following the manufacturer's guidelines, were also stable for at least 24 h and 8 h at 1 mg/mL and 3 mg/mL, respectively. All tested solutions were found physically stable up to 24 h at room temperature. The stability of dexrazoxane infusion solutions reported herein permits advance preparation of dexrazoxane intravenous admixtures, facilitating

  14. Authenticity screening of stained glass windows using optical spectroscopy

    Science.gov (United States)

    Meulebroeck, Wendy; Wouters, Hilde; Nys, Karin; Thienpont, Hugo

    2016-11-01

    Civilized societies should safeguard their heritage as it plays an important role in community building. Moreover, past technologies often inspire new technology. Authenticity is besides conservation and restoration a key aspect in preserving our past, for example in museums when exposing showpieces. The classification of being authentic relies on an interdisciplinary approach integrating art historical and archaeological research complemented with applied research. In recent decades analytical dating tools are based on determining the raw materials used. However, the traditional applied non-portable, chemical techniques are destructive and time-consuming. Since museums oftentimes only consent to research actions which are completely non-destructive, optical spectroscopy might offer a solution. As a case-study we apply this technique on two stained glass panels for which the 14th century dating is nowadays questioned. With this research we were able to identify how simultaneous mapping of spectral signatures measured with a low cost optical spectrum analyser unveils information regarding the production period. The significance of this research extends beyond the re-dating of these panels to the 19th century as it provides an instant tool enabling immediate answering authenticity questions during the conservation process of stained glass, thereby providing the necessary data for solving deontological questions about heritage preservation.

  15. A finite state projection algorithm for the stationary solution of the chemical master equation

    Science.gov (United States)

    Gupta, Ankit; Mikelson, Jan; Khammash, Mustafa

    2017-10-01

    The chemical master equation (CME) is frequently used in systems biology to quantify the effects of stochastic fluctuations that arise due to biomolecular species with low copy numbers. The CME is a system of ordinary differential equations that describes the evolution of probability density for each population vector in the state-space of the stochastic reaction dynamics. For many examples of interest, this state-space is infinite, making it difficult to obtain exact solutions of the CME. To deal with this problem, the Finite State Projection (FSP) algorithm was developed by Munsky and Khammash [J. Chem. Phys. 124(4), 044104 (2006)], to provide approximate solutions to the CME by truncating the state-space. The FSP works well for finite time-periods but it cannot be used for estimating the stationary solutions of CMEs, which are often of interest in systems biology. The aim of this paper is to develop a version of FSP which we refer to as the stationary FSP (sFSP) that allows one to obtain accurate approximations of the stationary solutions of a CME by solving a finite linear-algebraic system that yields the stationary distribution of a continuous-time Markov chain over the truncated state-space. We derive bounds for the approximation error incurred by sFSP and we establish that under certain stability conditions, these errors can be made arbitrarily small by appropriately expanding the truncated state-space. We provide several examples to illustrate our sFSP method and demonstrate its efficiency in estimating the stationary distributions. In particular, we show that using a quantized tensor-train implementation of our sFSP method, problems admitting more than 100 × 106 states can be efficiently solved.

  16. A finite state projection algorithm for the stationary solution of the chemical master equation.

    Science.gov (United States)

    Gupta, Ankit; Mikelson, Jan; Khammash, Mustafa

    2017-10-21

    The chemical master equation (CME) is frequently used in systems biology to quantify the effects of stochastic fluctuations that arise due to biomolecular species with low copy numbers. The CME is a system of ordinary differential equations that describes the evolution of probability density for each population vector in the state-space of the stochastic reaction dynamics. For many examples of interest, this state-space is infinite, making it difficult to obtain exact solutions of the CME. To deal with this problem, the Finite State Projection (FSP) algorithm was developed by Munsky and Khammash [J. Chem. Phys. 124(4), 044104 (2006)], to provide approximate solutions to the CME by truncating the state-space. The FSP works well for finite time-periods but it cannot be used for estimating the stationary solutions of CMEs, which are often of interest in systems biology. The aim of this paper is to develop a version of FSP which we refer to as the stationary FSP (sFSP) that allows one to obtain accurate approximations of the stationary solutions of a CME by solving a finite linear-algebraic system that yields the stationary distribution of a continuous-time Markov chain over the truncated state-space. We derive bounds for the approximation error incurred by sFSP and we establish that under certain stability conditions, these errors can be made arbitrarily small by appropriately expanding the truncated state-space. We provide several examples to illustrate our sFSP method and demonstrate its efficiency in estimating the stationary distributions. In particular, we show that using a quantized tensor-train implementation of our sFSP method, problems admitting more than 100 × 10 6 states can be efficiently solved.

  17. Chemical effects associated to (n, γ) nuclear reactions in diluted aqueous solutions of liquid or frozen organic halogenides

    International Nuclear Information System (INIS)

    Bermudez Rodriguez, I.M.

    1985-09-01

    Chemical effects associated to nuclear transformation 37 Cl (n, γ) 38 Cl or 127 I (n, γ) 128 I in solid or liquid aqueous solutions of ethyl iodide, trichloro-ethylene, thyroxine or DDT irradiated in a nuclear reactor are studied. The retention of radiohalogen under its initial chemical shape decrease with solute concentration in liquid phase but is almost constant with solute dilution in the solid phase. Potential applications in neutron activation analysis evidencing halogenated molecules in irradiated media are discussed. 57 refs [fr

  18. Highly sensitive methanol chemical sensor based on undoped silver oxide nanoparticles prepared by a solution method

    International Nuclear Information System (INIS)

    Rahman, M.M.; Khan, S.B.; Asiri, A.M.; Jamal, A.; Faisal, M.

    2012-01-01

    We have prepared silver oxide nanoparticles (NPs) by a simple solution method using reducing agents in alkaline medium. The resulting NPs were characterized by UV-vis and FT-IR spectroscopy, X-ray powder diffraction, and field-emission scanning electron microscopy. They were deposited on a glassy carbon electrode to give a sensor with a fast response towards methanol in liquid phase. The sensor also displays good sensitivity and long-term stability, and enhanced electrochemical response. The calibration plot is linear (r 2 = 0.8294) over the 0.12 mM to 0.12 M methanol concentration range. The sensitivity is ∼ 2.65 μAcm -2 mM -1 , and the detection limit is 36.0 μM (at a SNR of 3). We also discuss possible future prospective uses of this metal oxide semiconductor nanomaterial in terms of chemical sensing. (author)

  19. Preparation of functional composite materials based on chemically derived graphene using solution process

    International Nuclear Information System (INIS)

    Kim, M; Hyun, W J; Mun, S C; Park, O O

    2015-01-01

    Chemically derived graphenes were assembled into functional composite materials using solution process from stable solvent dispersion. We have developed foldable electronic circuits on paper substrates using vacuum filtration of graphene nanoplates dispersion and a selective transfer process without need for special equipment. The electronic circuits on paper substrates revealed only a small change in conductance under various folding angles and maintained an electronic path after repetitive folding and unfolding. We also prepared flexible. binder-free graphene paper-like materials by addition of graphene oxide as a film stabilizer. This graphene papers showed outstanding electrical conductivity up to 26,000 S/m and high charge capacity as an anode in lithium-ion battery without any post-treatments. For last case, multi-functional thin film structures of graphene nanoplates were fabricated by using layer-by-layer assembly technique, showing optical transparency, electrical conductivity and enhanced gas barrier property. (paper)

  20. Chemically induced dynamic electron polarization. Pulse radiolysis of aqueous solutions of alcohols

    International Nuclear Information System (INIS)

    Trifunac, A.D.; Thurnauer, M.C.

    1975-01-01

    The radical pair model of chemically induced dynamic electron polarization (CIDEP) is experimentally verified. Aqueous solutions of alcohols were irradiated with 3 MeV electrons and observed with time resolved electron paramagnetic resonance (EPR) spectroscopy. Relative line intensities of the polarized EPR spectra of radicals from methanol and especially ethylene glycol, alone and in the presence of radicals from compounds containing halogens, illustrates the polarization dependence on the g-factor differences between the radical pair components. The observation of the relative polarization enhancement in the various lines of the multiline EPR spectra illustrates the polarization dependence on the hyperfine terms. Intrinsic enhancements are calculated and are shown to be proportional to the observed enhancement, showing that the radical pair model of CIDEP is qualitatively correct

  1. Steam bubble growth in the bulk of overheated N2O4-NO chemically reacting solution

    International Nuclear Information System (INIS)

    Nemtsev, V.A.; Cherkashin, A.M.

    1989-01-01

    A mathematical model and numerical investigation of the vapour bubble growth that begins from the bubble critical size at the positive radius fluctuation during the initial moment in the bulk of the overheated N 2 O 4 -NO liquid solution are presented. The mathematical model has been stated under the following assumptions: the movement of a bubble wall and surrounding liquid is spherically symmetrical; thermal parameters in the bubble are distributed uniformly; the vapour phase follows the ideal gas law; heat transfer is not affected by the compressibility of liquid; if dissolution of light components is determined by Henry's law, then Hertz-Knudsen's equation determines the velocity of phase transition for a N 2 O 4 component. The mathematical model presented can be applied to another fluids, including chemically reacting ones

  2. Elaboration of strontium ruthenium oxide thin films on metal substrates by chemical solution deposition

    Energy Technology Data Exchange (ETDEWEB)

    Seveno, R. [Universite de Nantes, Institut de Recherche en Electrotechnique et Electronique de Nantes Atlantique (IREENA), 2, rue de la Houssiniere, BP 92208, 44322 Nantes Cedex 3 (France)]. E-mail: raynald.seveno@univ-nantes.fr; Braud, A. [Universite de Nantes, Institut de Recherche en Electrotechnique et Electronique de Nantes Atlantique (IREENA), 2, rue de la Houssiniere, BP 92208, 44322 Nantes Cedex 3 (France); Gundel, H.W. [Universite de Nantes, Institut de Recherche en Electrotechnique et Electronique de Nantes Atlantique (IREENA), 2, rue de la Houssiniere, BP 92208, 44322 Nantes Cedex 3 (France)

    2005-12-22

    In order to improve the structural interface between a metal substrate and a lead zirconate titanate (Pb(ZrTi)O{sub 3}, PZT) ferroelectric thin film, the elaboration of strontium ruthenium oxide (SrRuO{sub 3}) by chemical solution deposition is studied. The SrRuO{sub 3} thin films were realized by multiple spin-coating technique and the temperature of the rapid thermal annealing process was optimized. The crystallization behavior was examined by X-ray diffraction; surface analyses using scanning electron microscope and atomic force microscope techniques showed the influence of the SrRuO{sub 3} layer at the interface PZT/metal on the morphology of the ferroelectric thin film. From the electrical measurements, a coercive electric field around 25 kV/cm and a remanent polarization of approximately 30 {mu}C/cm were found.

  3. Elaboration of strontium ruthenium oxide thin films on metal substrates by chemical solution deposition

    International Nuclear Information System (INIS)

    Seveno, R.; Braud, A.; Gundel, H.W.

    2005-01-01

    In order to improve the structural interface between a metal substrate and a lead zirconate titanate (Pb(ZrTi)O 3 , PZT) ferroelectric thin film, the elaboration of strontium ruthenium oxide (SrRuO 3 ) by chemical solution deposition is studied. The SrRuO 3 thin films were realized by multiple spin-coating technique and the temperature of the rapid thermal annealing process was optimized. The crystallization behavior was examined by X-ray diffraction; surface analyses using scanning electron microscope and atomic force microscope techniques showed the influence of the SrRuO 3 layer at the interface PZT/metal on the morphology of the ferroelectric thin film. From the electrical measurements, a coercive electric field around 25 kV/cm and a remanent polarization of approximately 30 μC/cm were found

  4. Decontamination of adsorbed chemical warfare agents on activated carbon using hydrogen peroxide solutions.

    Science.gov (United States)

    Osovsky, Ruth; Kaplan, Doron; Nir, Ido; Rotter, Hadar; Elisha, Shmuel; Columbus, Ishay

    2014-09-16

    Mild treatment with hydrogen peroxide solutions (3-30%) efficiently decomposes adsorbed chemical warfare agents (CWAs) on microporous activated carbons used in protective garments and air filters. Better than 95% decomposition of adsorbed sulfur mustard (HD), sarin, and VX was achieved at ambient temperatures within 1-24 h, depending on the H2O2 concentration. HD was oxidized to the nontoxic HD-sulfoxide. The nerve agents were perhydrolyzed to the respective nontoxic methylphosphonic acids. The relative rapidity of the oxidation and perhydrolysis under these conditions is attributed to the microenvironment of the micropores. Apparently, the reactions are favored due to basic sites on the carbon surface. Our findings suggest a potential environmentally friendly route for decontamination of adsorbed CWAs, using H2O2 without the need of cosolvents or activators.

  5. Chemical castration: It is an acceptable solution for preventing the commission of sex crimes against minors?

    Directory of Open Access Journals (Sweden)

    Miladinović-Stefanović Dušica

    2014-01-01

    Full Text Available In addition to envisaging criminal offences which incriminate the different forms of sexual violence against minor and introducing stricter forms of punishment for sex offenders, the formal social reaction to sex crimes against minors often involves a series of measures aimed at monitoring the convicted offenders after they have served their sentences. These measures are basically aimed at reducing the risk of recidivism. One of these measures is a special pharmacological treatment, generally known as chemical castration, which is applied for the purpose of suppressing the offender's sexual urges and reducing sexual misconduct. In spite of being an appealing solution, chemical castration is acceptable only under specific conditions. Hence, this matter has to be regulated with exquisite caution in order to avoid the objections that this treatment constitutes a violation of the prohibition of torture, inhuman and degrading treatment and punishment, as well as a violation of the right to respect for private life and the right to establish a family.

  6. Effects of deposition time in chemically deposited ZnS films in acidic solution

    Energy Technology Data Exchange (ETDEWEB)

    Haddad, H.; Chelouche, A., E-mail: azeddinechelouche@gmail.com; Talantikite, D.; Merzouk, H.; Boudjouan, F.; Djouadi, D.

    2015-08-31

    We report an experimental study on the synthesis and characterization of zinc sulfide (ZnS) single layer thin films deposited on glass substrates by chemical bath deposition technique in acidic solution. The effect of deposition time on the microstructure, surface morphology, optical absorption, transmittance, and photoluminescence (PL) was investigated by X-ray diffraction (XRD), scanning electronic microscopy (SEM), UV-Vis–NIR spectrophotometry and photoluminescence (PL) spectroscopy. The results showed that the samples exhibit wurtzite structure and their crystal quality is improved by increasing deposition time. The latter, was found to affect the morphology of the thin films as showed by SEM micrographs. The optical measurements revealed a high transparency in the visible range and a dependence of absorption edge and band gap on deposition time. The room temperature PL spectra indicated that all ZnS grown thin films emit a UV and blue light, while the band intensities are found to be dependent on deposition times. - Highlights: • Single layer ZnS thin films were deposited by CBD in acidic solution at 95 °C. • The effect of deposition time was investigated. • Coexistence of ZnS and ZnO hexagonal structures for time deposition below 2 h • Thicker ZnS films were achieved after monolayer deposition for 5 h. • The highest UV-blue emission observed in thin film deposited at 5 h.

  7. Multi-scale modelling of ions in solution: from atomistic descriptions to chemical engineering

    International Nuclear Information System (INIS)

    Molina, J.J.

    2011-01-01

    Ions in solution play a fundamental role in many physical, chemical, and biological processes. The PUREX process used in the nuclear industry to the treatment of spent nuclear fuels is considered as an example. For industrial applications these systems are usually described using simple analytical models which are fitted to reproduce the available experimental data. In this work, we propose a multi-scale coarse graining procedure to derive such models from atomistic descriptions. First, parameters for classical force-fields of ions in solution are extracted from ab-initio calculations. Effective (McMillan-Mayer) ion-ion potentials are then derived from radial distribution functions measured in classical molecular dynamics simulations, allowing us to define an implicit solvent model of electrolytes. Finally, perturbation calculations are performed to define the best possible representation for these systems, in terms of charged hard-sphere models. Our final model is analytical and contains no free 'fitting' parameters. It shows good agreement with the exact results obtained from Monte-Carlo simulations for the thermodynamic and structural properties. Development of a similar model for the electrolyte viscosity, from information derived from atomistic descriptions, is also introduced. (author)

  8. Calculation of chemical equilibrium between aqueous solution and minerals: the EQ3/6 software package

    International Nuclear Information System (INIS)

    Wolery, T.J.

    1979-01-01

    The newly developed EQ/36 software package computes equilibrium models of aqueous geochemical systems. The package contains two principal programs: EQ3 performs distribution-of-species calculations for natural water compositions; EQ6 uses the results of EQ3 to predict the consequences of heating and cooling aqueous solutions and of irreversible reaction in rock--water systems. The programs are valuable for studying such phenomena as the formation of ore bodies, scaling and plugging in geothermal development, and the long-term disposal of nuclear waste. EQ3 and EQ6 are compared with such well-known geochemical codes as SOLMNEQ, WATEQ, REDEQL, MINEQL, and PATHI. The data base allows calculations in the temperature interval 0 to 350 0 C, at either 1 atm-steam saturation pressures or a constant 500 bars. The activity coefficient approximations for aqueous solutes limit modeling to solutions of ionic strength less than about one molal. The mathematical derivations and numerical techniques used in EQ6 are presented in detail. The program uses the Newton--Raphson method to solve the governing equations of chemical equilibrium for a system of specified elemental composition at fixed temperature and pressure. Convergence is aided by optimizing starting estimates and by under-relaxation techniques. The minerals present in the stable phase assemblage are found by several empirical methods. Reaction path models may be generated by using this approach in conjunction with finite differences. This method is analogous to applying high-order predictor--corrector methods to integrate a corresponding set of ordinary differential equations, but avoids propagation of error (drift). 8 figures, 9 tables

  9. Physico-Chemical Study of the Separation of Calcium Isotopes by Chemical Exchange Between Amalgam and Salt Solutions

    International Nuclear Information System (INIS)

    Duie, P.; Dirian, G.

    1962-01-01

    In a preliminary study of the isotopic exchange between Ca amalgam and aqueous or organic solutions of Ca salts, the main parameters governing the feasibility of a separation process based on these systems such as separation factor, exchange kinetics, rate of decomposition of the amalgam were investigated. The separation factor between 40 Ca and 46 Ca was found to be of the order of 1.02. The rate of the exchange reaction is rather low for aqueous solutions, extremely low for organic solutions. The amalgam seems not to be attacked by dimethyl-formamide solutions; but it is rapidly decomposed by aqueous solutions of Ca halides. This decomposition is slow in the case of aqueous solutions of calcium formate and still slower for Ca(OH) 2 ; however, except in particular conditions, the observed rate is often much higher, owing to interfering reactions between amalgam and water vapor contained in H 2 bubbles. (authors) [fr

  10. Background-free, high sensitivity staining of proteins in one- and two-dimensional sodium dodecyl sulfate-polyacrylamide gels using a luminescent ruthenium complex.

    Science.gov (United States)

    Berggren, K; Chernokalskaya, E; Steinberg, T H; Kemper, C; Lopez, M F; Diwu, Z; Haugland, R P; Patton, W F

    2000-07-01

    SYPRO Ruby dye is a permanent stain comprised of ruthenium as part of an organic complex that interacts noncovalently with proteins. SYPRO Ruby Protein Gel Stain provides a sensitive, gentle, fluorescence-based method for detecting proteins in one-dimensional and two-dimensional sodium dodecyl sulfate-polyacrylamide gels. Proteins are fixed, stained from 3h to overnight and then rinsed in deionized water or dilute methanol/acetic acid solution for 30 min. The stain can be visualized using a wide range of excitation sources commonly used in image analysis systems including a 302 nm UV-B transilluminator, 473 nm second harmonic generation (SHG) laser, 488 nm argon-ion laser, 532 nm yttrium-aluminum-garnet (YAG) laser, xenon arc lamp, blue fluorescent light bulb or blue light-emitting diode (LED). The sensitivity of SYPRO Ruby Protein Gel Stain is superior to colloidal Coomassie Brilliant Blue (CBB) stain or monobromobimane labeling and comparable with the highest sensitivity silver or zinc-imidazole staining procedures available. The linear dynamic range of SYPRO Ruby Protein Gel stain extends over three orders of magnitude, which is vastly superior to silver, zinc-imidazole, monobromobimane and CBB stain. The fluorescent stain does not contain superfluous chemicals (formaldehyde, glutaraldehyde, Tween-20) that frequently interfere with peptide identification in mass spectrometry. While peptide mass profiles are severely altered in protein samples prelabeled with monobromobimane, successful identification of proteins by peptide mass profiling using matrix-assisted laser desorption/ionization mass spectrometry was easily performed after protein detection with SYPRO Ruby Protein Gel stain.

  11. Root-induced Changes in the Rhizosphere of Extreme High Yield Tropical Rice: 2. Soil Solution Chemical Properties

    Directory of Open Access Journals (Sweden)

    Mitsuru Osaki

    2012-09-01

    Full Text Available Our previous studies showed that the extreme high yield tropical rice (Padi Panjang produced 3-8 t ha-1 without fertilizers. We also found that the rice yield did not correlate with some soil properties. We thought that it may be due to ability of root in affecting soil properties in the root zone. Therefore, we studied the extent of rice root in affecting the chemical properties of soil solution surrounding the root zone. A homemade rhizobox (14x10x12 cm was used in this experiment. The rhizobox was vertically segmented 2 cm interval using nylon cloth that could be penetrated neither root nor mycorrhiza, but, soil solution was freely passing the cloth. Three soils of different origins (Kuin, Bunipah and Guntung Papuyu were used. The segment in the center was sown with 20 seeds of either Padi Panjang or IR64 rice varieties. After emerging, 10 seedlings were maintained for 5 weeks. At 4 weeks after sowing, some chemical properties of the soil solution were determined. These were ammonium (NH4+, nitrate (NO3-, phosphorus (P and iron (Fe2+ concentrations and pH, electric conductivity (EC and oxidation reduction potential (ORP. In general, the plant root changed solution chemical properties both in- and outside the soil rhizosphere. The patterns of changes were affected by the properties of soil origins. The release of exudates and change in ORP may have been responsible for the changes soil solution chemical properties.

  12. YBa2Cu3O7-x thin films prepared by chemical solution deposition

    International Nuclear Information System (INIS)

    Apetrii, Claudia

    2009-01-01

    The discovery of superconductivity in ceramic materials by Bednorz and Mueller in early 1987, immediately followed by Wu et al., who showed that YBa 2 Cu 3 O 7-x (YBCO) becomes superconducting (92 K) well above the boiling point of nitrogen (77 K) created a great excitement in superconductivity research. Potential applications of high T c -superconductors require large critical currents and high-applied magnetic fields. Effective ways to increase the critical current density at high magnetic fields in YBCO are the introduction of nanoparticles and chemical substitution of yttrium by other rare earth elements. Since low costs and environmental compatibility are essential conditions for the preparation of long length YBCO films, the cost effective chemical solution deposition (CSD) procedure was selected, given that no vacuum technology is required. To reveal the flexibility and the good optimization possibilities of the CSD approach two main processes were chosen for comparison: a fluorine-free method, namely the polymer-metal precursor technique, and a fluorine-based method, the metalorganic deposition (MOD) using the trifluoroacetates (TFA) technique. Sharp transition temperature widths ΔT c of 1.1 K for the polymer metal method, 0.8 K for TFA method and critical current densities J c of ∼3.5 MA/cm 2 shows that high quality YBCO thin films can be produced using both techniques. Especially interesting is the magnetic field dependence of the critical current density J c (B) of the Y(Dy)BCO (80 %) films showing that for the lower magnetic fields the critical current density J c (B) is higher for a standard YBCO film, but at fields higher than 4.5 T the critical current density J c (B) of Y(Dy)BCO is larger than that for the YBCO. Above 8 T, J c (B) of the Y(Dy)BCO film is more than one order of magnitude higher than in pure YBCO film. (orig.)

  13. Effect of acidic aqueous solution on chemical and physical properties of polyamide NF membranes

    Science.gov (United States)

    Jun, Byung-Moon; Kim, Su Hwan; Kwak, Sang Kyu; Kwon, Young-Nam

    2018-06-01

    This work was systematically investigated the effects of acidic aqueous solution (15 wt% sulfuric acid as model wastewater from smelting process) on the physical and chemical properties of commercially available nanofiltration (NF) polyamide membranes, using piperazine (PIP)-based NE40/70 membranes and m-phenylene diamine (MPD)-based NE90 membrane. Surface properties of the membranes were studied before and after exposure to strong acid using various analytical tools: Scanning Electron Microscopy (SEM), Attenuated Total Reflectance-Fourier Transform Infrared spectroscopy (ATR-FTIR), X-ray photoelectron spectroscopy (XPS), Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS), contact angle analyzer, and electrophoretic light scattering spectrophotometer. The characterization and permeation results showed piperazine-based NE40/70 membranes have relatively lower acid-resistance than MPD-based NE90 membrane. Furthermore, density functional theory (DFT) calculation was also conducted to reveal the different acid-tolerances between the piperazine-based and MPD-based polyamide membranes. The easiest protonation was found to be the protonation of oxygen in piperazine-based monomer, and the N-protonation of the monomer had the lowest energy barrier in the rate determining step (RDS). The calculations were well compatible with the surface characterization results. In addition, the energy barrier in RDS is highly correlated with the twist angle (τD), which determines the delocalization of electrons between the carbonyl πCO bond and nitrogen lone pair, and the tendency of the twist angle was also maintained in longer molecules (dimer and trimer). This study clearly explained why the semi-aromatic membrane (NE40/70) is chemically less stable than the aromatic membrane (NE90) given the surface characterizations and DFT calculation results.

  14. Theory of First Order Chemical Kinetics at the Critical Point of Solution.

    Science.gov (United States)

    Baird, James K; Lang, Joshua R

    2017-10-26

    Liquid mixtures, which have a phase diagram exhibiting a miscibility gap ending in a critical point of solution, have been used as solvents for chemical reactions. The reaction rate in the forward direction has often been observed to slow down as a function of temperature in the critical region. Theories based upon the Gibbs free energy of reaction as the driving force for chemical change have been invoked to explain this behavior. With the assumption that the reaction is proceeding under relaxation conditions, these theories expand the free energy in a Taylor series about the position of equilibrium. Since the free energy is zero at equilibrium, the leading term in the Taylor series is proportional to the first derivative of the free energy with respect to the extent of reaction. To analyze the critical behavior of this derivative, the theories exploit the principle of critical point isomorphism, which is thought to govern all critical phenomena. They find that the derivative goes to zero in the critical region, which accounts for the slowing down observed in the reaction rate. As has been pointed out, however, most experimental rate investigations have been carried out under irreversible conditions as opposed to relaxation conditions [Shen et al. J. Phys. Chem. A 2015, 119, 8784-8791]. Below, we consider a reaction governed by first order kinetics and invoke transition state theory to take into account the irreversible conditions. We express the apparent activation energy in terms of thermodynamic derivatives evaluated under standard conditions as well as the pseudoequilibrium conditions associated with the reactant and the activated complex. We show that these derivatives approach infinity in the critical region. The apparent activation energy follows this behavior, and its divergence accounts for the slowing down of the reaction rate.

  15. Inkjet-Printed Chemical Solution Y2O3 Layers for Planarization of Technical Substrates

    Directory of Open Access Journals (Sweden)

    Marta Vilardell

    2017-12-01

    Full Text Available The implementation of the Chemical Solution Deposition (CSD methodology with the Drop on Demand (DoD inkjet printing (IJP technology has been successfully employed to develop a Solution Deposition Planarization (SDP method. We have used nanocrystalline yttrium oxide (Y2O3 to decrease the roughness of technical metallic substrates by filling the surface imperfections and thus avoiding costly polishing steps. This alternative process represents an outstanding methodology to reduce the final cost of the second-generation coated conductors manufacturing. Two Y2O3 metalorganic precursor ink formulations were successfully developed and tested to obtain surfaces as smooth as possible with adequate mechanical properties to hold the internal stress developed during the growth of the subsequent layers. By using these inks as precursors for IJP and after a proper tuning of the rheological and wetting parameters, we firstly obtained centimeter length uniform 100 nm-thick SDP-Y2O3 films on unpolished stainless-steel substrate from Bruker HTS. The scalability of the roll to roll (R2R-IJP process to 100 m is then demonstrated on metallic substrates as well. A complete characterization of the prepared SDP-Y2O3 inkjet-printed layers was carried out using optical microscopy, FIB-SEM (Focus Ion Beam coupled to Scanning Electron Microscopy, XRD (X-ray Diffraction, AFM (Atomic Force Microscopy, reflectometry and nanoindentation techniques. Then, the morphology, thickness, crystallinity and mechanical properties were evaluated, together with the surface roughness in order to assess the resulting layer planarity. The impact of planarity was additionally studied via growth of biaxially textured buffer layers as well as further functional layers. 1.1 µm-thick YSZ layers with in-plane textures better than the stainless steel (SS polished reference were successfully deposited on top of 100 nm SDP-Y2O3 films yielding 50% of Ic in contrast to the standard SS reference.

  16. Direct solution of the Chemical Master Equation using quantized tensor trains.

    Directory of Open Access Journals (Sweden)

    Vladimir Kazeev

    2014-03-01

    Full Text Available The Chemical Master Equation (CME is a cornerstone of stochastic analysis and simulation of models of biochemical reaction networks. Yet direct solutions of the CME have remained elusive. Although several approaches overcome the infinite dimensional nature of the CME through projections or other means, a common feature of proposed approaches is their susceptibility to the curse of dimensionality, i.e. the exponential growth in memory and computational requirements in the number of problem dimensions. We present a novel approach that has the potential to "lift" this curse of dimensionality. The approach is based on the use of the recently proposed Quantized Tensor Train (QTT formatted numerical linear algebra for the low parametric, numerical representation of tensors. The QTT decomposition admits both, algorithms for basic tensor arithmetics with complexity scaling linearly in the dimension (number of species and sub-linearly in the mode size (maximum copy number, and a numerical tensor rounding procedure which is stable and quasi-optimal. We show how the CME can be represented in QTT format, then use the exponentially-converging hp-discontinuous Galerkin discretization in time to reduce the CME evolution problem to a set of QTT-structured linear equations to be solved at each time step using an algorithm based on Density Matrix Renormalization Group (DMRG methods from quantum chemistry. Our method automatically adapts the "basis" of the solution at every time step guaranteeing that it is large enough to capture the dynamics of interest but no larger than necessary, as this would increase the computational complexity. Our approach is demonstrated by applying it to three different examples from systems biology: independent birth-death process, an example of enzymatic futile cycle, and a stochastic switch model. The numerical results on these examples demonstrate that the proposed QTT method achieves dramatic speedups and several orders of

  17. chemical studies on the extraction of certain metal ions from aqueous solution by liquid emulsion membrane

    International Nuclear Information System (INIS)

    Kassem, A.T.

    2011-01-01

    In this thesis four systems are addressed related to the use of liquid emulsion membranes (ELM) based on Co(III)dicarbiolide and. The system was dedicated for permeation of cadmium , cobalt Nickel and lead for use of this system for preconcentration and separation of cadmium, cobalt, nickel and lead. The work carried out in this thesis is presented in three parts, namely; introduction, experimental and results and discussion.The first chapter is the introduction which includes aim of work, basic concepts of liquid membranes; liquid emulsion membranes; different models of emulsion permeation, literature survey of extraction chemistry of cadmium, cobalt, nickel and lead. Chapter two includes the experimental part. In this part detailed outlines on the chemicals and different elements used were given. Different instruments as well as analytical techniques were outlines. The preparation of liquid emulsion membrane and the permeation techniques were presented in details. The third chapter deals with the results and discussion. This chapter is divided into four main parts, the four parts is concerned with cadmium/Co(III) dicarbolide/NTA, EDTA, DPTA and DCTA systems. In this part the permeation of Cd(II) aqueous solution by the membrane used was experimented based on liquid-liquid extraction studies of cadmium from different sodium chloride molarities (from 0.01 to 0.1 M) by 0.01 M Cobalt(III) dicarbolides. It was found that the extraction of with cadmium is higher following in the first system, the permeation of the toxic elements, Cd(II) from HCl/sodium chloride medium was carried out using liquid emulsion membrane containing Co(III)dicarbiolide in xylene as carrier, Spain 80/ Spain 85(1:3) as surfactant and NTA, EDTA, DPTA and DCTA as a stripping solutions.

  18. Uranium adsorption by non-treated and chemically modified cactus fibres in aqueous solutions

    International Nuclear Information System (INIS)

    Melpomeni Prodromou; Ioannis Pashalidis

    2013-01-01

    The adsorption efficiency of Opuntia ficus indica fibres regarding the removal of hexavalent uranium [U(VI)] from aqueous solutions has been investigated prior and after the chemical treatment (e.g. phosphorylation and MnO 2 -coating) of the biomass. The separation/removal efficiency has been studied as a function of pH, uranium concentration, adsorbent mass, ionic strength, temperature and contact time. Evaluation of the experimental data shows that biosorption is strongly pH-depended and that the MnO 2 -coated product presents the highest adsorption capacity followed by the phosphorylated and non-treated material. Experiments with varying ionic strength/salinity don't show any significant effect on the adsorption efficiency, indicating the formation of inner-sphere surface complexes. The adsorption reactions are in all cases exothermic and relatively fast, particularly regarding the adsorption on the MnO 2 -coated product. The results of the present study indicate that adsorption of uranium from waters is very effective by cactus fibres and particularly the modified treated fibres. The increased adsorption efficiency of the cactus fibres is attributed to their primary and secondary fibrillar structure, which result in a relative relative high specific surface available for sorption. (author)

  19. Chemical solution deposited BaPbO3 buffer layers for lead zirconate titanate ferroelectric films

    International Nuclear Information System (INIS)

    Tseng, T.-K.; Wu, J.-M.

    2005-01-01

    Conductive perovskite BaPbO 3 (BPO) films have been prepared successfully by chemical solution deposition method through spin-coating on Pt/Ti/SiO 2 /Si substrates. The choice of baking temperature is a key factor on the development of conducting BPO perovskite phase. When the baking temperature is higher than 350 deg. C, the BPO films contain a high content of BaCO 3 phase after annealing at temperatures higher than 500 deg. C. If the baking temperature is chosen lower than 300 deg. C, such as 200 deg. C, the annealed BPO films consist mostly of perovskite with only traces of BaCO 3 . Choosing 200 deg. C as the baking temperature, the BPO films developed single perovskite phase at temperatures as low as 550 deg. C. The perovskite BPO phase is stable in the range of 550-650 deg. C and the measured sheet resistance of the BPO films is about 2-3 Ω/square. The perovskite BPO film as a buffer layer provides improvement in electric properties of lead zirconate titanate films

  20. Deposition barium titanate (BaTiO3) doped lanthanum with chemical solution deposition

    International Nuclear Information System (INIS)

    Iriani, Y.; Nurhadi, N.; Jamaludin, A.

    2016-01-01

    Deposition of Barium Titanate (BaTiO 3 ) thin films used Chemical Solution Deposition (CSD) method and prepared with spin coater. BaTiO 3 is doped with lanthanum, 1%, 2%, and 3%. The thermal process use annealing temperature 900°C and holding time for 3 hours. The result of characterization with x-ray diffraction (XRD) equipment show that the addition of La 3+ doped on Barium Titanate caused the change of angle diffraction.The result of refine with GSAS software shows that lanthanum have been included in the structure of BaTiO 3 . Increasing mol dopant La 3+ cause lattice parameter and crystal volume become smaller. Characterization result using Scanning Electron Microscopy (SEM) equipment show that grain size (grain size) become smaller with increasing mole dopant (x) La 3+ . The result of characterization using Sawyer Tower methods show that all the samples (Barium Titanante and Barium Titanate doped lanthanum) are ferroelectric material. Increasing of mole dopant La 3+ cause smaller coercive field and remanent polarization increases. (paper)

  1. Chemical solution deposition of LaMnO3-based films for coated conductors

    International Nuclear Information System (INIS)

    Shi, D Q; Zhu, X B; Kim, J H; Wang, L; Zeng, R; Dou, S X; Lei, H C; Sun, Y P

    2008-01-01

    LaMnO 3 -based films were prepared using the chemical solution deposition method. It was found that the films on perovskite oxide single crystal substrates are highly (h00)-oriented when the annealing atmosphere is oxygen or air; however, when the substrate is yttrium-stabilized ZrO 2 , only the La 1-x Na x MnO 3 films are highly (h00)-oriented, and other LaMnO 3 -based films are (110)-oriented. Under a reducing annealing atmosphere, the atmosphere must be wet in order to create a suitable oxygen partial pressure to crystallize the LaMnO 3 -based films. After annealing under a wet reducing atmosphere the LaMnO 3 -based films are (110)-oriented when the films are directly deposited on Ni tapes; however, when SrTiO 3 -buffered Ni tapes are used, the LaMnO 3 films are (h00)-oriented, which is suitable for subsequent growth of YBCO. The results suggest that it is possible to tune the orientation of buffer layers using suitable templates, which can widen the selection of buffer layers for coated conductors in the all metallorganic deposition approach

  2. Physical chemical radiation effects in scintillator solutions content PPO and POPOP

    International Nuclear Information System (INIS)

    Fernandes Neto, Jose Mari; Hamada, Margarida Mizue; Duarte, Celina Lopes; Mesquita, Carlos Henrique de

    2005-01-01

    Samples containing PPO (1%, g/mL), diluted in toluene, were irradiated in a 60 Co irradiator (6.46 kGy/h) at different doses. The PPO concentration decay bi-exponentially with the dose, generating the degradation products: benzoic acid, benzamide and benzilic alcohol. The liquid scintillator system was not sensitive to the radiation damage until 20 kGy. Otherwise, the pulse height analysis showed that doses between 30 and 40 kGy generated significant loss of quality of the sensor (scintillating liquid) and the light yield was reduced in half with the dose of (34.04 ± 0.80) kGy. This value was confirmed by the photopeak position analysis that resulted in D1/2 = (31.7 ± 1.4) kGy. The transmittance, at 360 nm, of the irradiated solution decreased exponentially. The compartmental model using five compartments (fast decay PPO, slow decay PPO, benzamide, benzoic acid and benzilic alcohol) was satisfactory to explain the decay of the PPO in its degradation products as a function of the dose. The explanation coefficient r2 = 0.985636 demonstrates that the model was capable to explain 98.6% of the experimental variations. The energies involved in the chemical reactions were w = (0.239 ± 0.031) eV/damage (fast decay) and w (1.834 ± 0.301) eV/damage (slow decay). (author)

  3. Evaluation of unsaturated-zone solute-transport models for studies of agricultural chemicals

    Science.gov (United States)

    Nolan, Bernard T.; Bayless, E. Randall; Green, Christopher T.; Garg, Sheena; Voss, Frank D.; Lampe, David C.; Barbash, Jack E.; Capel, Paul D.; Bekins, Barbara A.

    2005-01-01

    Seven unsaturated-zone solute-transport models were tested with two data sets to select models for use by the Agricultural Chemical Team of the U.S. Geological Survey's National Water-Quality Assessment Program. The data sets were from a bromide tracer test near Merced, California, and an atrazine study in the White River Basin, Indiana. In this study the models are designated either as complex or simple based on the water flux algorithm. The complex models, HYDRUS2D, LEACHP, RZWQM, and VS2DT, use Richards' equation to simulate water flux and are well suited to process understanding. The simple models, CALF, GLEAMS, and PRZM, use a tipping-bucket algorithm and are more amenable to extrapolation because they require fewer input parameters. The purpose of this report is not to endorse a particular model, but to describe useful features, potential capabilities, and possible limitations that emerged from working with the model input data sets. More rigorous assessment of model applicability involves proper calibration, which was beyond the scope of this study.

  4. Effect of organic solvents on dissolution process of mechano-chemically activated molybdenum by inorganic acid solutions

    International Nuclear Information System (INIS)

    Shevtsova, I.Ya.; Chernyak, A.S.; Khal'zov, A.A.

    1992-01-01

    The process of chemical dissolution of mechanochemically activated and nonactivated molybdenite by inorganic acid solutions in certain organic solvents of different nature was considered. It is shown that the highest extraction of molybdenum in solution is achieved in the presence of nitric acid. The dissociation constant of the acid used in the given organic solvent does not affect molybdenite solubility. When dissolving molybdenite by solutions of nitric acid in carbonic acids, alcohols and esters, the solubility of the concentrate depends on the length of hydrocarbon chain of the organic solvent and dispersion degree of mineral source material

  5. Alteration of medieval stained-glasses. Contribution to the long-term behaviour of vitrified wastes

    International Nuclear Information System (INIS)

    Sterpenich, J.

    1998-01-01

    In this work, the behaviour of glasses during alteration have been studied in two different ways: 1)study of the alteration of medieval stained-glasses 2)experimental leaching of modelled glasses. Medieval stained-glasses have a silico-calcic and alkaline composition. It appears three different alteration modes for these glasses: 1)by condensation waters 2)by atmospheric agents 3)by porosity waters and humic acids. A chemical study of the altered areas has allowed to understand the alteration behaviour of a lot of elements: in particular transition elements, heavy metals and some rare earths. On the other hand, two vitrified wastes and a glass having the same composition of the potassic medieval stained-glasses have been leached in a static mode (pH=1 to 10, T=20 to 80 degrees Celsius, T=12 hours to 6 months). These experiments have revealed that the alteration mechanisms depend on the pH of the solution and on the chemical composition of the glass. An increasing durability of glasses in terms of the global polymerization degree has been revealed too. At last, the behaviours of glasses during alteration, observed with natural and experimental conditions, show that it is necessary to study natural analogous for predicting the long-term behaviour of vitrified wastes. (O.M.)

  6. Thick Fe2O3, Fe3O4 films prepared by the chemical solution deposition method

    Czech Academy of Sciences Publication Activity Database

    Buršík, Josef; Košovan, P.; Šubrt, Jan

    2006-01-01

    Roč. 39, č. 2 (2006), s. 85-94 ISSN 0928-0707 R&D Projects: GA ČR GA203/01/0408 Institutional research plan: CEZ:AV0Z40320502 Keywords : chemical solution deposition * thick films * alpha-Fe2O3 Subject RIV: CA - Inorganic Chemistry Impact factor: 1.009, year: 2006

  7. Chemical composition of the humus layer, mineral soil and soil solution of 150 forest stands in the Netherlands in 1990

    NARCIS (Netherlands)

    Vries, de W.; Leeters, E.E.J.M.

    2001-01-01

    A nationwide assessment of the chemical composition of the humus layer, mineral topsoil (0-30 cm) and soil solution in both topsoil and subsoil (60-100 cm) was made for 150 forest stands in the year 1990. The stands, which were part of the national forest inventory on vitality, included seven tree

  8. Studying Equilibrium in the Chemical Reaction between Ferric and Iodide Ions in Solution Using a Simple and Inexpensive Approach

    Science.gov (United States)

    Nikolaychuk, Pavel Anatolyevich; Kuvaeva, Alyona Olegovna

    2016-01-01

    A laboratory experiment on the study of the chemical equilibrium based on the reaction between ferric and iodide ions in solution with the formation of ferrous ions, free iodine, and triiodide ions is developed. The total concentration of iodide and triiodide ions in the reaction mixture during the reaction is determined by the argentometric…

  9. Chemical composition of the humus layer, mineral soil and soil solution of 200 forest stands in the Netherlands in 1995

    NARCIS (Netherlands)

    Leeters, E.E.J.M.; Vries, de W.

    2001-01-01

    A nationwide assessment of the chemical composition of the soil solid phase and the soil solution in the humus layer and two mineral layers (0-10 cm and 10-30 cm) was made for 200 forest stands in the year 1995. The stands were part of the national forest inventory on vitality, included seven tree

  10. Chemical equilibrium of hydrogen and aqueous solutions of 1 : 1 bicarbonate and formate salts with a common cation

    NARCIS (Netherlands)

    Engel, D.C.; Versteeg, G.F.; Swaaij, W.P.M. van

    1997-01-01

    The chemical equilibrium of hydrogen and aqueous solutions of 1:1 bicarbonate and formate salts with a common cation has been investigated in an intensively stirred batch reactor: MHCO3(aq) + H2(aq) ↔ MOOCH(aq) + H2O(l) This was accomplished for the sodium (M = Na), potassium (M = K) and ammonium (M

  11. Laboratory Evaluation of the Clean Earth Technologies Decontamination Solutions for Chemical and Biological Agents

    Science.gov (United States)

    2008-01-01

    TA. The DAAMs tubes are analyzed using a Marks UNITY/ULTRA thermal desorption system coupled to an Agilent 6890N gas chromatography -mass selective...tryptic- soy broth (TSB) or tryptic- soy agar (TSA). Frozen stock of bacterial cells, stored at -80 ’C in TSB supplemented with glycerol to a final...NNRidl) were prepared, heat-treated and ethanol-treated before staining with Malachite Green and viewed under oil immersion lens. The green to dark blue

  12. Ionic Diffusion and Kinetic Homogeneous Chemical Reactions in the Pore Solution of Porous Materials with Moisture Transport

    DEFF Research Database (Denmark)

    Johannesson, Björn

    2009-01-01

    Results from a systematic continuum mixture theory will be used to establish the governing equations for ionic diffusion and chemical reactions in the pore solution of a porous material subjected to moisture transport. The theory in use is the hybrid mixture theory (HMT), which in its general form......’s law of diffusion and the generalized Darcy’s law will be used together with derived constitutive equations for chemical reactions within phases. The mass balance equations for the constituents and the phases together with the constitutive equations gives the coupled set of non-linear differential...... general description of chemical reactions among constituents is described. The Petrov – Galerkin approach are used in favour of the standard Galerkin weighting in order to improve the solution when the convective part of the problem is dominant. A modified type of Newton – Raphson scheme is derived...

  13. Etika Berbusana Mahasiswa Stain Samarinda

    Directory of Open Access Journals (Sweden)

    Ida Suryani Wijaya

    2012-06-01

    Full Text Available Ethics is about behavior of human being, such as which one is right or wrong. The ethics is always affecting the human life. The ethics gives people orientation how he/she do manything every time every day. Islamic ethics consists of the way how someone interact each other; how someone should do or not to do, how to sit, how to walk, how to eat or drink, how to sleep, or how to get dressed. Al-Qur’an uses three terms to define about dressing, they are: libas, tsiyah, and sarahi. Dressing has a function as covering the body, as assessoris, as the way to do Islamic taqwa, and as an identiy. Dressing ethics of the female students of STAIN Samarinda has been regulated by the rector regulation No 19 of the year 2002 about relation and dressing ethics for the students of STAIN Samarinda.

  14. Solution of the chemical master equation by radial basis functions approximation with interface tracking

    NARCIS (Netherlands)

    Kryven, I.; Röblitz, S; Schütte, C.

    2015-01-01

    Background: The chemical master equation is the fundamental equation of stochastic chemical kinetics. This differential-difference equation describes temporal evolution of the probability density function for states of a chemical system. A state of the system, usually encoded as a vector, represents

  15. Improved method for combination of immunocytochemistry and Nissl staining.

    Science.gov (United States)

    Kádár, Andrea; Wittmann, Gábor; Liposits, Zsolt; Fekete, Csaba

    2009-10-30

    Nissl staining is a widely used method to study morphology and pathology of neural tissue. After standard immunocytochemistry, the Nissl staining labels only the nucleus of neurons and the characteristic staining of the neuronal perikarya is absent or very weak. We hypothesized that the RNA degradation during the immunocytochemical treatment results in the loss of cytoplasmic staining with Nissl-dyes. To test this hypothesis, we used RNAse-free conditions for all steps of immunostaining. To further prevent the RNA-degradation by RNAse contaminations, the RNAse inhibitor heparin was added to all antibody-containing solutions. The efficiency of Nissl staining after standard and RNAse-free double-labeling immunocytochemistry was compared using antibodies against c-Fos and neuropeptide Y (NPY) on tissues of rats refed after 3 days of fasting. After standard immunocytochemistry, the Nissl-staining labeled the nuclei of neurons and only very faintly the cytoplasm of these cells. The RNAse-free treatment did not alter the distribution of immunoreaction signal, but preserved the staining of neuronal perikarya by the Nissl-dyes. In conclusion, the RNAse-free conditions during immunocytochemistry allow the labeling of neuronal perikarya by Nissl-dyes. The described method facilitates the mapping of immunocytochemical signals and makes possible the light microscopic examination of the innervation of neurons identified by their nuclear protein content.

  16. Silver and Cyanine Staining of Oligonucleotides in Polyacrylamide Gel.

    Science.gov (United States)

    Tang, Weizhong; Zhou, Huafu; Li, Wei

    2015-01-01

    To explore why some oligonucleotides in denaturing polyacrylamide gel could not be silver-stained, 134 different oligonucleotides were analyzed using denaturing polyacrylamide gel electrophoresis stained with silver and asymmetric cyanine. As a result, we found that the sensitivity of oligos (dA), (dC), (dG) and (dT) to silver staining could be ranged as (dA) > (dG) > (dC) > (dT) from high to low. It was unexpected that oligo (dT) was hard to be silver-stained. Moreover, the silver staining of an oligonucleotide containing base T could be partially or completely inhibited by base T. The inhibition of silver staining by base T was a competitive inhibition which could be affected by the amounts of the argyrophil nucleobase and base T, the cis-distance between the argyrophil nucleobase and base T, and the gel concentration. The changes of the intensity of an oligonucleotide band caused by the changes of DNA base composition were diverse and interesting. The intensity of some oligonucleotide bands would significantly change when the changes of DNA base composition accumulated to a certain extent (usually ≥ 4 nt). The sensitivity of cyanine staining of ≤ 11-nt long oligonucleotides could be enhanced about 250-fold by fixing the gels with methanol fixing solution.

  17. A novel washing algorithm for underarm stain removal

    Science.gov (United States)

    Acikgoz Tufan, H.; Gocek, I.; Sahin, U. K.; Erdem, I.

    2017-10-01

    After contacting with human sweat which comprise around 27% sebum, anti-perspirants comprising aluminium chloride or its compounds form a jel-like structure whose solubility in water is very poor. In daily use, this jel-like structure closes sweat pores and hinders wetting of skin by sweat. However, when in contact with garments, they form yellowish stains at the underarm of the garments. These stains are very hard to remove with regular machine washing. In this study, first of all, we focused on understanding and simulating such stain formation on the garments. Two alternative procedures are offered to form jel-like structures. On both procedures, commercially available spray or deo-stick type anti-perspirants, standard acidic and basic sweat solutions and artificial sebum are used to form jel-like structures, and they are applied on fabric in order to get hard stains. Secondly, after simulation of the stain on the fabric, we put our efforts on developing a washing algorithm specifically designed for removal of underarm stains. Eight alternative washing algorithms are offered with varying washing temperature, amounts of detergent, and pre-stain removal procedures. Better algorithm is selected by comparison of Tristimulus Y values after washing.

  18. Chemical luminescence measurement of singlet oxygen generated by photodynamic therapy in solutions in real time

    Science.gov (United States)

    Luo, Shiming; Xing, Da; Zhou, Jing; Qin, Yanfang; Chen, Qun

    2005-04-01

    Photodynamic therapy (PDT) is a cancer therapy that utilizes optical energy to activate a photosensitizer drug in a target tissue. Reactive oxygen species (ROS), such as 1O2 and superoxide, are believed to be the major cytotoxic agents involved in PDT. Although current PDT dosimetry mostly involves measurements of light and photosensitizer doses delivered to a patient, the quantification of ROS production during a treatment would be the ultimate dosimetry of PDT. Technically, it is very difficult and expensive to directly measure the fluorescence from 1O2, due to its extreme short lifetime and weak signal strength. In this paper, Photofrin(R) and 635nm laser were used to generate 1O2 and superoxide in a PDT in solution. Compound 3,7- dihydro-6-{4-[2-(N"-(5-fluoresceinyl) thioureido) ethoxy] phenyl}-2- methylimidazo{1,2-a} pyrazin-3-one sodium salt,an Cyp- ridina luciferin analog commonly referred as FCLA, was used as a chemical reporter of ROS. The 532nm chemiluminescence (CL) from the reaction of the FCLA and ROS was detected with a photon multiplier tube (PMT) system operating at single photon counting mode. With the setup, we have made detections of ROS generated by PDT in real time. By varying the amount of conventional PDT dosage (photosensitizer concentration, light irradiation fluence and its delivery rate) and the amount of FCLA, the intensity of CL and its consumption rate were investigated. The results show that the intensity and temporal profile of CL are highly related to the PDT treatment parameters. This suggests that FCLA CL may provide a highly potential alternative for ROS detection during PDT.

  19. Deposition and characteristics of PbS thin films by an in-situ solution chemical reaction process

    Energy Technology Data Exchange (ETDEWEB)

    Ji, Junna; Ji, Huiming; Wang, Jian; Zheng, Xuerong; Lai, Junyun; Liu, Weiyan; Li, Tongfei [School of Materials Science and Engineering, Key Laboratory for Advanced Ceramics and Machining Technology of Ministry of Education, Tianjin University, Tianjin 300072 (China); Ma, Yuanliang; Li, Haiqin; Zhao, Suqin [College of Physics and Electronic Information Engineering, Qinghai University for Nationalities, Xining 810007 (China); Jin, Zhengguo, E-mail: zhgjin@tju.edu.cn [School of Materials Science and Engineering, Key Laboratory for Advanced Ceramics and Machining Technology of Ministry of Education, Tianjin University, Tianjin 300072 (China)

    2015-09-01

    Preferential oriented and uniform PbS thin films were deposited by a room temperature in-situ solution chemical reaction process, in which the lead nitrate as precursor in a form of thin solid films from lead precursor solution was used to react with ammonium sulfide ethanol solution. Influence of 1-butanol addition in the lead precursor solution, Pb:S molar ratios in the separate cationic and anionic solutions, deposition cycle numbers and annealing treatment in Ar atmosphere on structure, morphology, chemical composition and optical absorption properties of the deposited PbS films were investigated based on X-ray diffraction, field emission scanning electron microscopy, energy dispersive spectrometer, atomic force microscopy, selected area electron diffraction, UV–vis, near infrared ray and fourier transform infrared spectroscopy measurements. The results showed that the deposited PbS thin films had a cubic structure and highly preferred orientation along with the plane (100). The deposition rate of single-layer was stable, about 30 nm in thickness per deposition cycle. - Highlights: • Time-efficiency synthetic method for the preparation of lead sulfide (PbS) films • Effect of 1-butanol addition into cationic precursor solution is discussed. • Growth rate of the PbS films is stable at about 30 nm per cycle.

  20. On mechanism of chlorophos radiation-chemical decomposition in aqueous solutions

    International Nuclear Information System (INIS)

    Danilin, D.I.; Shubin, V.N.

    1992-01-01

    Quantitative indices of chlorophos decomposition in a aqueous solution and in solutions with a number of additions are studied. Chlorine ions and substances containing the carbonyl group are found among the products of gamma-irradiation of low-concentration chlorophos solutions. The data supporting the running of radiation destructive reactions of reduction nature rather than oxidation type, are presented

  1. Effects of Pig Slurry Application and Crops on Phosphorus Content in Soil and the Chemical Species in Solution

    Directory of Open Access Journals (Sweden)

    Lessandro De Conti

    2015-06-01

    Full Text Available The application of pig slurry rates and plant cultivation can modify the soil phosphorus (P content and distribution of chemical species in solution. The purpose of this study was to evaluate the total P, available P and P in solution, and the distribution of chemical P species in solution, in a soil under longstanding pig slurry applications and crop cultivation. The study was carried out in soil columns with undisturbed structure, collected in an experiment conducted for eight years in the experimental unit of the Universidade Federal de Santa Maria (UFSM, Santa Maria (RS. The soil was an Argissolo Vermelho distrófico arênico (Typic Hapludalf, subjected to applications of 0, 20, 40, and 80 m3 ha-1 pig slurry. Soil samples were collected from the layers 0-5, 5-10, 10-20, 20-30, 30-40, and 40-60 cm, before and after black oat and maize grown in a greenhouse, for the determination of available P, total P and P in the soil solution. In the solution, the concentration of the major cations, anions, dissolved organic carbon (DOC, and pH were determined. The distribution of chemical P species was determined by software Visual Minteq. The 21 pig slurry applications increased the total P content in the soil to a depth of 40 cm, and the P extracted by Mehlich-1 and from the solution to a depth of 30 cm. Successive applications of pig slurry changed the balance between the solid and liquid phases in the surface soil layers, increasing the proportion of the total amount of P present in the soil solution, aside from changing the chemical species in the solution, reducing the percentage complexed with Al and increasing the one complexed with Ca and Mg in the layers 0-5 and 5-10 cm. Black oat and maize cultivation increased pH in the solution, thereby increasing the proportion of HPO42- and reducing H2PO4- species.

  2. KDP Aqueous Solution-in-Oil Microemulsion for Ultra-Precision Chemical-Mechanical Polishing of KDP Crystal

    Directory of Open Access Journals (Sweden)

    Hui Dong

    2017-03-01

    Full Text Available A novel functional KH2PO4 (KDP aqueous solution-in-oil (KDP aq/O microemulsion system for KDP crystal ultra-precision chemical-mechanical polishing (CMP was prepared. The system, which consisted of decanol, Triton X-100, and KH2PO4 aqueous solution, was available at room temperature. The functional KDP aq/O microemulsion system was systematically studied and applied as polishing solution to KDP CMP technology. In this study, a controlled deliquescent mechanism was proposed for KDP polishing with the KDP aq/O microemulsion. KDP aqueous solution, the chemical etchant in the polishing process, was caged into the micelles in the microemulsion, leading to a limitation of the reaction between the KDP crystal and KDP aqueous solution only if the microemulsion was deformed under the effect of the external force. Based on the interface reaction dynamics, KDP aqueous solutions with different concentrations (cKDP were applied to replace water in the traditional water-in-oil (W/O microemulsion. The practicability of the controlled deliquescent mechanism was proved by the decreasing material removal rate (MRR with the increasing of the cKDP. As a result, the corrosion pits on the KDP surface were avoided to some degree. Moreover, the roughnesses of KDP with KDP aq/O microemulsion (cKDP was changed from 10 mM to 100 mM as polishing solutions were smaller than that with the W/O microemulsion. The smallest surface root-mean-square roughness of 1.5 nm was obtained at a 30 mmol/L KDP aq solution, because of the most appropriate deliquescent rate and MRR.

  3. Influence of activating solution and the addition of NaF on metakaolin-based geopolymer physico-chemical properties

    International Nuclear Information System (INIS)

    Agullo, J.; Muzeau, B.; Trepy, N.; L'Hostis, V.; Lambertin, D.

    2015-01-01

    The technology of geo-polymerisation is attracting a lot of interest due to the wide variety of potential applications. Recently emerging and alternative cementitious systems based on geo-polymers have been reported in literature. Geo-polymer materials have been proposed as new binders for safe radioactive waste containment. Moreover, their good fluidity and fire resistance make them compatible with industrial processes for embedding wastes. The purpose of this work was to investigate the physico-chemical properties of meta-kaolin-based geo-polymer which could be used as mineral binder for encapsulation of metallic nuclear wastes. To improve the knowledge of this binder, its microstructure and its interstitial solution have been characterized during hydration (up to 28 days). Interstitial solutions were extracted at different hydration time and subsequent analyses allow us to determine their chemical composition. pH measurements confirm the high alkalinity of the interstitial pore solution. The influence of the activating solution (NaOH or KOH) and the addition of NaF as corrosion inhibitor in the geo-polymer composition were also studied. The nature of different crystalline phases was identified by X-ray diffraction. Water accessible porosity for these materials was estimated around 59%. The pore size distribution was determined by mercury intrusion porosity. Alkaline cations have proved to induce changes in the pore size distribution, these ones coming from whether the activating solution or the NaF addition. (authors)

  4. Radiation-chemical behaviour of neptunium ions in nitric acid solutions in the presence of curium-244

    International Nuclear Information System (INIS)

    Frolova, L.M.; Frolov, A.A.; Vasil'ev, V.Ya.

    1984-01-01

    Radiation-chemical behaviour of neptunium ions in nitric acid solutions is studied under the action of intensive internal alpha-irradiation conditioned by curium nuclides. In 0.3-1.1 mol/l solutions of nitric acid radiation-chemical oxidation of neptunium (4) and reduction of neptunium (6) is obeyed to the first order law of reaction rate in respect to neptunium concentration. Effective constants of neptunium (4) oxidation rates and neptuniumi(6) reduction rates are not dependent on neptunium ion in1tial concentration and increase with a growth of a dose rate of alpha-irradiation of solution. In equilibrium only neptunium (5) and neptunium (6) are present in solutions with HNO 3 concentration less than 1 mol/l. In more concentrated solutions equilibrium between sexa-, penta- and tetravalent neptunium forms is established. Equilibrium concentrations of neptunium valent forms are not dependent on neptunium initial oxidation state under the same initial conditions (dose rate, neptunium concentration and acidity. It is shown form experimental data that under the action of alpha-irradiation neptunium (5) both is oxidated to neptunium (6) and is reduced to neptunium (4)

  5. Physico-chemical properties of aqueous drug solutions: From the basic thermodynamics to the advanced experimental and simulation results.

    Science.gov (United States)

    Bellich, Barbara; Gamini, Amelia; Brady, John W; Cesàro, Attilio

    2018-04-05

    The physical chemical properties of aqueous solutions of model compounds are illustrated in relation to hydration and solubility issues by using three perspectives: thermodynamic, spectroscopic and molecular dynamics simulations. The thermodynamic survey of the fundamental backgrounds of concentration dependence and experimental solubility results show some peculiar behavior of aqueous solutions with several types of similar solutes. Secondly, the use of a variety of experimental spectroscopic devices, operating under different experimental conditions of dimension and frequency, has produced a large amount of structural and dynamic data on aqueous solutions showing the richness of the information produced, depending on where and how the experiment is carried out. Finally, the use of molecular dynamics computational work is presented to highlight how the different types of solute functional groups and surface topologies organize adjacent water molecules differently. The highly valuable contribution of computer simulation studies in providing molecular explanations for experimental deductions, either of a thermodynamic or spectroscopic nature, is shown to have changed the current knowledge of many aqueous solution processes. While this paper is intended to provide a collective view on the latest literature results, still the presentation aims at a tutorial explanation of the potentials of the three methodologies in the field of aqueous solutions of pharmaceutical molecules. Copyright © 2018. Published by Elsevier B.V.

  6. Chemically and compositionally modified solid solution disordered multiphase nickel hydroxide positive electrode for alkaline rechargeable electrochemical cells

    Science.gov (United States)

    Ovshinsky, Stanford R.; Corrigan, Dennis; Venkatesan, Srini; Young, Rosa; Fierro, Christian; Fetcenko, Michael A.

    1994-01-01

    A high capacity, long cycle life positive electrode for use in an alkaline rechargeable electrochemical cell comprising: a solid solution nickel hydroxide material having a multiphase structure that comprises at least one polycrystalline .gamma.-phase including a polycrystalline .gamma.-phase unit cell comprising spacedly disposed plates with at least one chemical modifier incorporated around the plates, the plates having a range of stable intersheet distances corresponding to a 2.sup.+ oxidation state and a 3.5.sup.+, or greater, oxidation state; and at least one compositional modifier incorporated into the solid solution nickel hydroxide material to promote the multiphase structure.

  7. Autofluorescence of routinely hematoxylin and eosin- stained ...

    African Journals Online (AJOL)

    SERVER

    2008-03-04

    Mar 4, 2008 ... nary Tissue Bank” (www.veterinary-tissue-bank-egypt.com). All tissues were fixed in 10% formalin solution for at least 48 h, dehy-. *Corresponding author. ... amount and distribution of endogenous fluorophores and chemical-physical properties of their microenvironment. This was clear in our study through ...

  8. Accelerated staining technique using kitchen microwave oven

    Directory of Open Access Journals (Sweden)

    Archana Mukunda

    2015-01-01

    Full Text Available Introduction: Histopathological diagnosis of specimens is greatly dependent on good sample preparation and staining. Both of these processes is governed by diffusion of fluids and dyes in and out of the tissue, which is the key to staining. Diffusion of fluids can be accelerated by the application of heat that reduces the time of staining from hours to the minute. We modified an inexpensive model of kitchen microwave oven for staining. This study is an attempt to compare the reliability of this modified technique against the tested technique of routine staining so as to establish the kitchen microwave oven as a valuable diagnostic tool. Materials and Methods: Sixty different tissue blocks were used to prepare 20 pairs of slides for 4 different stains namely hematoxylin and eosin, Van Gieson′s, 0.1% toluidine blue and periodic acid-Schiff. From each tissue block, two bits of tissues were mounted on two different slides. One slide was stained routinely, and the other stained inside a microwave. A pathologist evaluated the stained slides and the results so obtained were analyzed statistically. Results: Microwave staining considerably cut down the staining time from hours to seconds. Microwave staining showed no loss of cellular and nuclear details, uniform-staining characteristics and was of excellent quality. Interpretation and Conclusion: The cellular details, nuclear details and staining characteristics of microwave stained tissues were better than or equal to the routine stained tissue. The overall quality of microwave-stained sections was found to be better than the routine stained tissue in majority of cases.

  9. Chemical analysis of freshly prepared and stored capsaicin solutions: implications for tussigenic challenges.

    Science.gov (United States)

    Kopec, Scott E; DeBellis, Ronald J; Irwin, Richard S

    2002-01-01

    The purpose of this study was to assess the stability of stored capsaicin solutions and the actual concentrations of prepared solutions. Capsaicin solutions ranging in concentration from 0.5 to 128 microM were mixed and analyzed using high performance liquid chromatography. Samples of varying concentrations were then stored under 4 environmental conditions: 4 degrees C and protected from light, room temperature (RT) exposed to light, RT protected from light, and -20 degrees C and protected from light. The concentrations were measured every other month for 1 year. Actual concentrations of freshly prepared solutions were on average 88.3% of predicted. For solutions stored at 4 degrees C, there was a decrease only in the lower concentrations (0.5, 1, and 2 microM) after 2 months (P=0.003). Solutions stored at RT exposed to light decreased in concentration after 6 months (P=0.020), and solutions stored at RT protected from light decreased in concentration after 4 months (P=0.026). The group stored at -20 degrees C decreased in concentration after 1 year (P=0.033). We conclude that the actual concentration of capsaicin solution is less than predicted, and solutions of 4 microM or higher concentration are stable for 1 year if stored at 4 degrees C protected from light.

  10. Chemical analysis of zinc electroplating solutions by x-ray fluorescence spectrometry

    International Nuclear Information System (INIS)

    Jung, Sung-Mo; Cho, Young-Mo; Na, Han-Gil

    2007-01-01

    A quantitative analysis method used to analyze chlorine, iron and zinc in electroplating solutions, using X-ray spectrometry in atmospheric He mode, is proposed. The present research concerns the replacement of the conventional analyses of electroplating solutions with rapid and reproducible quantification using X-ray fluorescence spectrometer. An in-depth investigation conducted in the present study identifies the species present in the real electroplating solutions. XRD patterns and semi-quantitative results for the electroplating solutions show synthetic standards based on the compositional range of solutions by analyzing the electroplating solutions obtained in real processes. 28 calibration standard solutions are prepared by diluting liquid standard solutions certified by titration and ICP-OES analyses used to construct the XRF calibration curves for Cl, Fe and Zn. The suggested method showed satisfactory precision and accuracy in the analysis of electroplating solutions. The present study provides evidences that the proposed XRF spectrometry could be an alternative analytical method to replace the conventional techniques by comparing the uncertainties estimated for each method. (author)

  11. Calculations of physical and chemical reactions with DNA in aqueous solution from Auger cascades

    International Nuclear Information System (INIS)

    Wright, H.A.; Hamm, R.N.; Turner, J.E.; Howell, R.W.; Rao, D.V.; Sastry, K.S.R.

    1989-01-01

    Monte Carlo calculations are performed of the physical and chemical interactions in liquid water by electrons produced during Auger cascades resulting from the decay of various radionuclides. Estimates are also made of the number of direct physical and indirect chemical interactions that would be produced on DNA located near the decay site. 13 refs., 8 figs

  12. Mystery Well: Chemical-Engineering Solution to the Internal Rain Problem.

    Czech Academy of Sciences Publication Activity Database

    Růžička, Marek

    2017-01-01

    Roč. 174, DEC 31 (2017), s. 396-402 ISSN 0009-2509 Institutional support: RVO:67985858 Keywords : precipitation * humidity-driven convection * buoyant instability Subject RIV: CI - Industrial Chemistry, Chemical Engineering OBOR OECD: Chemical process engineering Impact factor: 2.895, year: 2016

  13. Chemical effects induced by dissolving γ-irradiated alkali halides in aqueous nitrate, permanganate and chromate solutions

    International Nuclear Information System (INIS)

    Phansalkar, V.K.; Bapat, L.; Ravishankar, D.

    1982-01-01

    Dissolution of γ-irradiated alkali halides in aqueous solutions of sodium nitrate, potassium permanganate and potassium chromate at neutral pH induces chemical changes leading to the formation of NO 2 - in nitrate, Mn(IV) and Cr(III) species in permanganate and chromate solutions, respectively. Further, the studies on nitrate and permanganate systems show that the amount of NO 2 - and Mn(IV) formed grows by increasing the dose of γ-irradiation of the salt and the amount of irradiated salt. Moreover, the extent of chemical changes effected by irradiated chlorides has been found to be more than that of bromides. The mesh size of the irradiated salt and the presence of scavengers like I - and methanol in the system, affects the yield of NO 2 - . (author)

  14. A Cross-Age Study on the Understanding of Chemical Solutions and Their Components

    Science.gov (United States)

    Calik, Muammer; Ayas, Alipasa

    2005-01-01

    The aims of this study were considered under three headings. The first was to elicit misconceptions that students had about the terms "solute", "solvent" and "solution." The second was to understand how students' prior learning affected their misconceptions. The third was to determine if students were able to make a…

  15. Aqueous solutions that model the cytosol : studies on polarity, chemical reactivity and enzyme kinetics

    NARCIS (Netherlands)

    Asaad, N.; den Otter, M.J.; Engberts, J.B.F.N.

    2004-01-01

    Concentrated solutions of a series of organic compounds have been prepared and the effects of these solutes on the properties of the solvent system assessed as a function of their concentration and nature. Polarity, as measured by Reichardt's E-T(30) probe, exhibits a linear variation with both

  16. Modeling the chemical kinetics of atmospheric plasma for cell treatment in a liquid solution

    International Nuclear Information System (INIS)

    Kim, H. Y.; Kang, S. K.; Lee, H. Wk.; Lee, H. W.; Kim, G. C.; Lee, J. K.

    2012-01-01

    Low temperature atmospheric pressure plasmas have been known to be effective for living cell inactivation in a liquid solution but it is not clear yet which species are key factors for the cell treatment. Using a global model, we elucidate the processes through which pH level in the solution is changed from neutral to acidic after plasma exposure and key components with pH and air variation. First, pH level in a liquid solution is changed by He + and He(2 1 S) radicals. Second, O 3 density decreases as pH level in the solution decreases and air concentration decreases. It can be a method of removing O 3 that causes chest pain and damages lung tissue when the density is very high. H 2 O 2 , HO 2 , and NO radicals are found to be key factors for cell inactivation in the solution with pH and air variation.

  17. Role of the buffer solution in the chemical deposition of CdS films for CIGS solar cell applications

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sooho; Kim, Donguk; Baek, Dohyun; Hong, Byoungyou; Yi, Junsin; Lee, Jaehyeong [Sungkyunkwan University, Suwon (Korea, Republic of); Park, Yongseob [Chosun College of Science and and Technology, Gwangju (Korea, Republic of); Choi, Wonseok [Hanbat National University, Daejeon (Korea, Republic of)

    2014-05-15

    In this work, the effects of NH{sub 4}Ac on the structural and the electro-optical properties of CdS films were investigated. CdS thin films were deposited on soda-lime glass and indium-tin-oxide (ITO) coated glass from a chemical bath containing 0.025 M cadmium acetate, 0 M ∼ 0.2 M ammonium acetate, 0.5 M thiourea, and ammonia. Cadmium acetate was the cadmium source, ammonium acetate served as a buffer, ammonia was the complexing agent, and thiourea was the source of sulfur. A commonly- available chemical bath deposition system was successfully modified to obtain precise control over the pH of the solution at 75 .deg. C during the deposition. Chemically deposited CdS films were studied by using field-emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), optical transmittance, and electrical resistivity measurements.

  18. Improved AMOLED with aligned poly-Si thin-film transistors by laser annealing and chemical solution treatments

    International Nuclear Information System (INIS)

    Wu, G.M.; Chen, C.N.; Feng, W.S.; Lu, H.C.

    2009-01-01

    Low-temperature polycrystalline silicon (LTPS) thin-film transistors (TFT) were prepared for the active-matrix organic light-emitting displays (AMOLED). The excimer laser annealing (ELA) recrystallization technique was employed with a chemical solution treatment process to improve the TFT characteristic uniformity and the AMOLED display image quality. The characteristics of the poly-Si array thin films were influenced by XeCl ELA optic module design, TFT device channel direction, and laser irradiation overlap ratio. The ELA system module provided aligned poly-Si grain size of 0.3 μm by the homogenization lens design. The chemical solution treatment process included a dilute HF solution (DHF), ozone (O 3 ) water, and buffer oxide etching solution (BOE). The PMOS TFT showed better field effect mobility of 87.6 cm 2 /V s, and the threshold voltage was -1.35 V. The off current (I off ) was 1.25x10 -11 A, and the on/off current ratio was 6.27x10 6 . In addition, the image quality of the AMOLED display was highly improved using the 2T1C structure design without any compensation circuit.

  19. Nucleic acid stains as indicators of Giardia muris viability following cyst inactivation.

    Science.gov (United States)

    Taghi-Kilani, R; Gyürék, L L; Millard, P J; Finch, G R; Belosevic, M

    1996-06-01

    A reliable viability assay for Giardia is required for the development of disinfection process design criteria and pathogen monitoring by water treatment utilities. Surveys of single-staining nucleic acid dyes (stain dead parasites only), and double-staining vital dye kits from Molecular Probes (stain live and dead parasites) were conducted to assess the viability of untreated, heat-killed, and chemically inactivated Giardia muris cysts. Nucleic acid staining results were compared to those of in vitro excystation and animal infectivity. Nucleic acid stain, designated as SYTO-9, was considered the best among the single-staining dyes for its ability to stain dead cysts brightly and its relatively slow decay rate of visible light emission following DNA binding. SYTO-9 staining was correlated to animal infectivity. A Live/Dead BacLight was found to be the better of 2 double-staining viability kits tested. Logarithmic survival ratios based on SYTO-9 and Live/Dead BacLight were compared to excystation and infectivity results for G. muris cysts exposed to ozone or free chlorine. The results indicate that SYTO-9 and Live/Dead BacLight staining is stable following treatment of cysts with chemical disinfectants.

  20. Microwave Plasma Enhanced Chemical Vapor Deposition of Diamond in Vapor of Methanol-Based Liquid Solutions

    National Research Council Canada - National Science Library

    Tzeng, Yonhua

    2000-01-01

    .... Liquid solutions are prepared by mixing methanol with other carbon containing liquid compounds which contain a greater than one ratio of carbon to oxygen such as acetone, ethanol, and iso-propanol...

  1. Texturization of as-cut p-type monocrystalline silicon wafer using different wet chemical solutions

    Science.gov (United States)

    Hashmi, Galib; Hasanuzzaman, Muhammad; Basher, Mohammad Khairul; Hoq, Mahbubul; Rahman, Md. Habibur

    2018-06-01

    Implementing texturization process on the monocrystalline silicon substrate reduces reflection and enhances light absorption of the substrate. Thus texturization is one of the key elements to increase the efficiency of solar cell. Considering as-cut monocrystalline silicon wafer as base substrate, in this work different concentrations of Na2CO3 and NaHCO3 solution, KOH-IPA (isopropyl alcohol) solution and tetramethylammonium hydroxide solution with different time intervals have been investigated for texturization process. Furthermore, saw damage removal process was conducted with 10% NaOH solution, 20 wt% KOH-13.33 wt% IPA solution and HF/nitric/acetic acid solution. The surface morphology of saw damage, saw damage removed surface and textured wafer were observed using optical microscope and field emission scanning electron microscopy. Texturization causes pyramidal micro structures on the surface of (100) oriented monocrystalline silicon wafer. The height of the pyramid on the silicon surface varies from 1.5 to 3.2 µm and the inclined planes of the pyramids are acute angle. Contact angle value indicates that the textured wafer's surface fall in between near-hydrophobic to hydrophobic range. With respect to base material absolute reflectance 1.049-0.75% within 250-800 nm wavelength region, 0.1-0.026% has been achieved within the same wavelength region when textured with 0.76 wt% KOH-4 wt% IPA solution for 20 min. Furthermore, an alternative route of using 1 wt% Na2CO3-0.2 wt% NaHCO3 solution for 50 min has been exploited in the texturization process.

  2. Reactive solute transport in physically and chemically heterogeneous porous media with multimodal reactive mineral facies: the Lagrangian approach.

    Science.gov (United States)

    Soltanian, Mohamad Reza; Ritzi, Robert W; Dai, Zhenxue; Huang, Chao Cheng

    2015-03-01

    Physical and chemical heterogeneities have a large impact on reactive transport in porous media. Examples of heterogeneous attributes affecting reactive mass transport are the hydraulic conductivity (K), and the equilibrium sorption distribution coefficient (Kd). This paper uses the Deng et al. (2013) conceptual model for multimodal reactive mineral facies and a Lagrangian-based stochastic theory in order to analyze the reactive solute dispersion in three-dimensional anisotropic heterogeneous porous media with hierarchical organization of reactive minerals. An example based on real field data is used to illustrate the time evolution trends of reactive solute dispersion. The results show that the correlation between the hydraulic conductivity and the equilibrium sorption distribution coefficient does have a significant effect on reactive solute dispersion. The anisotropy ratio does not have a significant effect on reactive solute dispersion. Furthermore, through a sensitivity analysis we investigate the impact of changing the mean, variance, and integral scale of K and Kd on reactive solute dispersion. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Reformulation and solution of the master equation for multiple-well chemical reactions.

    Science.gov (United States)

    Georgievskii, Yuri; Miller, James A; Burke, Michael P; Klippenstein, Stephen J

    2013-11-21

    We consider an alternative formulation of the master equation for complex-forming chemical reactions with multiple wells and bimolecular products. Within this formulation the dynamical phase space consists of only the microscopic populations of the various isomers making up the reactive complex, while the bimolecular reactants and products are treated equally as sources and sinks. This reformulation yields compact expressions for the phenomenological rate coefficients describing all chemical processes, i.e., internal isomerization reactions, bimolecular-to-bimolecular reactions, isomer-to-bimolecular reactions, and bimolecular-to-isomer reactions. The applicability of the detailed balance condition is discussed and confirmed. We also consider the situation where some of the chemical eigenvalues approach the energy relaxation time scale and show how to modify the phenomenological rate coefficients so that they retain their validity.

  4. Interpretation of soil-to-plant transfer on the basis of soil solution chemical composition

    International Nuclear Information System (INIS)

    Lembrechts, J.F.; Van Loon, L.R.; Van Ginkel, J.H.; Desmet, G.M.

    1988-01-01

    Soil-to-plant translocation of a radionuclide depends on its availability on the one hand and on the efficiency of the uptake process on the other. Criticism on the use of transfer coefficients for the description of translocation mainly concerns the fact that the complex variety of processes, a.o. dependent on plant characteristics and soil type and treatment, is integrated in a single ratio. For the interpretation of the effect of counter-measures the static transfer coefficient proved to be hard to handle and knowledge of the separate underlying processes and their time dependence showed to be indispensible. Based upon translocation experiments with technetium, cobalt, strontium and zinc transfer was shown to be primarily related to the concentration of the plant available fraction in the soil solution as well as to the soil solution chemistry in general. The transfer factor of the first three elements expressed in the basis of soil solution activity (ml/g), was observed to decrease when the nutrient content of the soil solution -- reflected by its conductivity -- increased. The characteristics of the soil matrix (solid phase) furthermore showed to be of secondary importance for the explanation of the observed accumulation. Since the interstitial soil liquid phase mediates between solid phase and plant root, reliable interpretations of soil-to-plant transfer might as a rule be based on a separate study of the effect of soil properties on availability on the one hand of the uptake from nutrient solutions on the other

  5. Real cause of detrimental carbonation in chemically stabilized layers and possible solutions

    CSIR Research Space (South Africa)

    Botha, PB

    2005-10-01

    Full Text Available to determine the other reaction that may take place in the material. KEYWORDS CARBONATION/ CHEMICAL REACTIONS/ WATER CURING/ NEW TESTING PROTOCOL 1 INTRODUCTION This paper deals with the problems related to the “curing” of the stabilized layers... than CO2 driven. In actually fact the so-called “detrimental carbonation” chemical reaction cannot even take place without free water being available. The water is normally supplied by the specified curing 2 technique to keep the layer moist...

  6. Brahmaputra river basin groundwater: Solute distribution, chemical evolution and arsenic occurrences in different geomorphic settings

    Directory of Open Access Journals (Sweden)

    Swati Verma

    2015-09-01

    New hydrological insights for the region: Most groundwater solutes of RCD and YA terrains were derived from both silicate weathering and carbonate dissolution, while silicate weathering process dominates the solute contribution in OA groundwater. Groundwater samples from all terrains are postoxic with mean pe values between Fe(III and As(V–As(III reductive transition. While, reductive dissolution of (Fe–MnOOH is the dominant mechanism of As mobilization in RCD and YA aquifers, As in OA and PD aquifers could be mobilized by combined effect of pH dependent sorption and competitive ion exchange. The present study focuses on the major ion chemistry as well as the chemistry of the redox sensitive solutes of the groundwater in different geomorphic settings and their links to arsenic mobilization in groundwater.

  7. Gram staining with an automatic machine.

    Science.gov (United States)

    Felek, S; Arslan, A

    1999-01-01

    This study was undertaken to develop a new Gram-staining machine controlled by a micro-controller and to investigate the quality of slides that were stained in the machine. The machine was designed and produced by the authors. It uses standard 220 V AC. Staining, washing, and drying periods are controlled by a timer built in the micro-controller. A software was made that contains a certain algorithm and time intervals for the staining mode. One-hundred and forty smears were prepared from Escherichia coli, Staphylococcus aureus, Neisseria sp., blood culture, trypticase soy broth, direct pus and sputum smears for comparison studies. Half of the slides in each group were stained with the machine, the other half by hand and then examined by four different microbiologists. Machine-stained slides had a higher clarity and less debris than the hand-stained slides (p stained slides, some Gram-positive organisms showed poor Gram-positive staining features (p Gram staining with the automatic machine increases the staining quality and helps to decrease the work load in a busy diagnostic laboratory.

  8. Systems and methods for laser assisted sample transfer to solution for chemical analysis

    Science.gov (United States)

    Van Berkel, Gary J; Kertesz, Vilmos; Ovchinnikova, Olga S

    2013-08-27

    Systems and methods are described for laser ablation of an analyte from a specimen and capturing of the analyte in a dispensed solvent to form a testing solution. A solvent dispensing and extraction system can form a liquid microjunction with the specimen. The solvent dispensing and extraction system can include a surface sampling probe. The laser beam can be directed through the surface sampling probe. The surface sampling probe can also serve as an atomic force microscopy probe. The surface sampling probe can form a seal with the specimen. The testing solution including the analyte can then be analyzed using an analytical instrument or undergo further processing.

  9. The influence of the “cage effect” on the mechanism of reversible bimolecular multistage chemical reactions in solutions

    International Nuclear Information System (INIS)

    Doktorov, Alexander B.

    2015-01-01

    Manifestations of the “cage effect” at the encounters of reactants are theoretically treated by the example of multistage reactions in liquid solutions including bimolecular exchange reactions as elementary stages. It is shown that consistent consideration of quasi-stationary kinetics of multistage reactions (possible only in the framework of the encounter theory) for reactions proceeding near reactants contact can be made on the basis of the concepts of a “cage complex.” Though mathematically such a consideration is more complicated, it is more clear from the standpoint of chemical notions. It is established that the presence of the “cage effect” leads to some important effects not inherent in reactions in gases or those in solutions proceeding in the kinetic regime, such as the appearance of new transition channels of reactant transformation that cannot be caused by elementary event of chemical conversion for the given mechanism of reaction. This results in that, for example, rate constant values of multistage reaction defined by standard kinetic equations of formal chemical kinetics from experimentally measured kinetics can differ essentially from real values of these constants

  10. The influence of the "cage effect" on the mechanism of reversible bimolecular multistage chemical reactions in solutions.

    Science.gov (United States)

    Doktorov, Alexander B

    2015-08-21

    Manifestations of the "cage effect" at the encounters of reactants are theoretically treated by the example of multistage reactions in liquid solutions including bimolecular exchange reactions as elementary stages. It is shown that consistent consideration of quasi-stationary kinetics of multistage reactions (possible only in the framework of the encounter theory) for reactions proceeding near reactants contact can be made on the basis of the concepts of a "cage complex." Though mathematically such a consideration is more complicated, it is more clear from the standpoint of chemical notions. It is established that the presence of the "cage effect" leads to some important effects not inherent in reactions in gases or those in solutions proceeding in the kinetic regime, such as the appearance of new transition channels of reactant transformation that cannot be caused by elementary event of chemical conversion for the given mechanism of reaction. This results in that, for example, rate constant values of multistage reaction defined by standard kinetic equations of formal chemical kinetics from experimentally measured kinetics can differ essentially from real values of these constants.

  11. The influence of the “cage effect” on the mechanism of reversible bimolecular multistage chemical reactions in solutions

    Energy Technology Data Exchange (ETDEWEB)

    Doktorov, Alexander B., E-mail: doktorov@kinetics.nsc.ru [Voevodsky Institute of Chemical Kinetics & Combustion, Siberian Branch of the Russian Academy of Sciences, 630090 Novosibirsk, Russia and Novosibirsk State University, Novosibirsk 630090 (Russian Federation)

    2015-08-21

    Manifestations of the “cage effect” at the encounters of reactants are theoretically treated by the example of multistage reactions in liquid solutions including bimolecular exchange reactions as elementary stages. It is shown that consistent consideration of quasi-stationary kinetics of multistage reactions (possible only in the framework of the encounter theory) for reactions proceeding near reactants contact can be made on the basis of the concepts of a “cage complex.” Though mathematically such a consideration is more complicated, it is more clear from the standpoint of chemical notions. It is established that the presence of the “cage effect” leads to some important effects not inherent in reactions in gases or those in solutions proceeding in the kinetic regime, such as the appearance of new transition channels of reactant transformation that cannot be caused by elementary event of chemical conversion for the given mechanism of reaction. This results in that, for example, rate constant values of multistage reaction defined by standard kinetic equations of formal chemical kinetics from experimentally measured kinetics can differ essentially from real values of these constants.

  12. Erbium doped stain etched porous silicon

    International Nuclear Information System (INIS)

    Gonzalez-Diaz, B.; Diaz-Herrera, B.; Guerrero-Lemus, R.; Mendez-Ramos, J.; Rodriguez, V.D.; Hernandez-Rodriguez, C.; Martinez-Duart, J.M.

    2008-01-01

    In this work a simple erbium doping process applied to stain etched porous silicon layers (PSLs) is proposed. This doping process has been developed for application in porous silicon solar cells, where conventional erbium doping processes are not affordable because of the high processing cost and technical difficulties. The PSLs were formed by immersion in a HF/HNO 3 solution to properly adjust the porosity and pore thickness to an optimal doping of the porous structure. After the formation of the porous structure, the PSLs were analyzed by means of nitrogen BET (Brunauer, Emmett and Teller) area measurements and scanning electron microscopy. Subsequently, the PSLs were immersed in a saturated erbium nitrate solution in order to cover the porous surface. Then, the samples were subjected to a thermal process to activate the Er 3+ ions. Different temperatures and annealing times were used in this process. The photoluminescence of the PSLs was evaluated before and after the doping processes and the composition was analyzed by Fourier transform IR spectroscopy

  13. Mitigation options for chemicals of emerging concern in surface waters operationalising solutions-focused risk assessment

    NARCIS (Netherlands)

    Van Wezel, Annemarie P.; Ter Laak, Thomas L.; Fischer, Astrid; Bäuerlein, Patrick S.; Munthe, John; Posthuma, Leo

    2017-01-01

    The water system provides many services to society; industries, municipalities and agriculture all withdraw, use and return water and demand a water quality fit for the intended purposes. Both global production of chemicals and global water withdrawal grow faster than human population. This implies

  14. Model Experiments on Chemical Properties of Superheavy Elements in Aqueous Solutions

    CERN Document Server

    Szeglowski, Z

    2003-01-01

    This paper presents a brief review of model experiments on investigation of chemical properties of transactinide elements, ranging from 104 to 116. The possibilities of isolation of the nuclei of these elements from nuclear reaction products, using the ion-exchange method, are also considered.

  15. Control of Chemical Equilibrium by Solvent: A Basis for Teaching Physical Chemistry of Solutions

    Science.gov (United States)

    Prezhdo, Oleg V.; Craig, Colleen F.; Fialkov, Yuriy; Prezhdo, Victor V.

    2007-01-01

    The study demonstrates that the solvent present in a system can highly alter and control the chemical equilibrium of a system. The results show that the dipole moment and polarizibility of a system can be highly altered by using different mixed solvents.

  16. The chemical behavior of acidified chromium (3) solutions. B.S. Thesis

    Science.gov (United States)

    Terman, D. K.

    1981-01-01

    A unique energy-storage system has been developed at NASA's Lewis Research Center called REDOX. This NASA-REDOX system is an electrochemical storage device that utilized the oxidation and reduction of two fully soluble redox couples for charging and discharging. The redox couples now being investigated are acidified chloride solutions of chromium (Cr(+2)/Cr(+3)) and iron (Fe(+2)/Fe(+3)).

  17. [Physical and chemical stability of fortified ophtalmic ready-to-use solutions: review of literature].

    Science.gov (United States)

    Sourdeau, P; Evrard, J-M; Remy, G; Hecq, J-D

    2012-03-01

    Ophtalmic infections and inflammations are often encountered during hospitalization. They require the preparation of "fortified" ophtalmic solutions, i.e. pharmaceutical ophtalmic solutions which are hyperconcentrated in active substance. The data of physicochemical stabilities are modified and it is therefore essential to gather the results of the various publications devoted to this subject. In 2006, an initial literature review was undertaken to identify the molecules mostly used in the preparation of fortified ophtalmic solutions in hospital. A second review of the literature in 2010 has enriched the knowledge about it. Two new drugs have entered the summary table: amikacin and ticarcillin disodium. Date on 12 molecules already known in 2006 were updated to improve clinical practices. A review of the literature was undertaken in order to collect the results of the molecules mostly used for the preparation of the fortified ophtalmic solutions in hospitals. A summary table, indicating the active substance, its concentration, the assay method, the storage temperature and physicochemical modifications, presents all the results. This review of literature makes it possible to match stability and validity period to these preparations. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

  18. The etching of InP in HCl solutions : a chemical mechanism

    NARCIS (Netherlands)

    Notten, P.H.L.

    1984-01-01

    The etch rate of InP in solutions of high HCl concentration was shown to be independent of the applied potential ina wide potential range negative with respect to the flatband value. Dissolution of the solid led to the formation of PH3.The etch rate, which was not mass-transport controlled, was

  19. Effect of Solution pH on the Adsorption of Paracetamol on Chemically Modified Activated Carbons

    Directory of Open Access Journals (Sweden)

    Valentina Bernal

    2017-06-01

    Full Text Available Paracetamol adsorption in acidic, neutral and basic media on three activated carbons with different chemistry surfaces was studied. A granular activated carbon (GAC was prepared from coconut shell; starting from this sample, an oxidized activated carbon (GACo was obtained by treating the GAC with a boiling solution of 6 M nitric acid, so to generate a greater number of oxygenated surface groups. In addition, a reduced activated carbon (GACr was obtained by heating the GAC at 1173 K, to remove the oxygenated surface groups. Paracetamol adsorption was higher for GACr due to the lower presence of oxygenated surface functional groups. Moreover, adsorption was highest at neutral pH. The magnitude of the interactions between paracetamol molecules and activated carbons was studied by measuring the immersion enthalpies of activated carbons in solution of paracetamol at different concentrations and pH values and by calculating the interaction enthalpy. The highest value was obtained for GACr in a paracetamol solution of 1000 mg L−1 at pH 7, confirming that paracetamol adsorption is favoured on basic activated carbons at pH values near to neutrality. Finally, the Gibbs energy changes confirmed the latter result, allowing explaining the different magnitudes of the interactions between paracetamol and activated carbons, as a function of solution pH.

  20. Chemically modified carbon paste electrode for fast screening of oxalic acid levels in soil solutions

    Czech Academy of Sciences Publication Activity Database

    Šestáková, Ivana; Jakl, M.; Jaklová Dytrtová, J.

    2008-01-01

    Roč. 102, - (2008), s. 140-140 E-ISSN 1213-7103. [International Conference on Electroanalysis /12./. 16.06.2008-19.06.2008, Prague] R&D Projects: GA ČR GA521/06/0496 Institutional research plan: CEZ:AV0Z40400503 Keywords : oxalic acid * carbon paste electrodes * soil solutions Subject RIV: CG - Electrochemistry

  1. Two decades of chemical imaging of solutes in sediments and soils

    DEFF Research Database (Denmark)

    Santner, Jakob; Larsen, Morten; Kreuzeder, Andreas

    2015-01-01

    understanding of biogeochemical processes regulating the distribution of key elements and solutes including O2, CO2, pH, redox conditions as well as nutrient and contaminant ion species in structurally complex soils and sediments. Recently these methods have been applied in parallel or integrated as so...

  2. Chemical behaviour of americium in natural aquatic solutions: Hydrolysis, radiolysis and redox reactions

    International Nuclear Information System (INIS)

    Stadler, S.; Kim, J.I.

    1988-06-01

    Hydrolysis and redox reactions of the Am(III) and Am(V) ions have been investigated in NaClO 4 and NaCl solutions as well as in natural saline groundwaters. The hydrolysis constants of Am(OH) n 3-n species and the solubility product of Am(OH) 3 (s) have been determined in 0.1 M NaClO 4 , 0.1 M NaCl and 0.6 M NaCl solutions. As observed in concentrated NaCl solutions (> 3 M), the α-radiation induces the radiolytic oxidation of the Cl - -ion to produce Cl 2 , HClO, ClO - and other oxidized species, which result in a strongly oxidizing medium. Consequently Am(III) is oxidized to Am(V). Under these conditions the hydrolysis constants of AmO 2 (OH) n 1-n species and the solubility product are also determined. The α-radiation induced radiolysis reactions in NaCl solution and the subsequent oxidation reaction of Am(III) have been systematically investigated by varying pH, NaCl concentration and specific α-activity. Also included in the investigation are a few selected groundwaters of relatively high salinity from the Gorleben aquifer systems. (orig.) [de

  3. Indocyanine green staining facilitates detection of bleb leakage during trabeculectomy.

    Science.gov (United States)

    Okazaki, Teruhiko; Kiuchi, Takahiro; Kawana, Keisuke; Oshika, Tetsuro

    2007-03-01

    To report a new technique to visualize bleb leakage using indocyanine green (ICG) staining during trabeculectomy. The ICG solution was widely applied over the filtering bleb including the conjunctival wound before completion of trabeculectomy. This procedure was performed in 48 eyes of 44 consecutive patients undergoing trabeculectomy between December 2004 and October 2005. Without staining, bleb leakage was not identified by the direct observation under the operating microscope. ICG staining clearly visualized aqueous leakage from the bleb in 5 eyes (10.4%). The bleb leakage in these eyes was easily repaired with 10-0 nylon sutures, and no eyes, including these 5 cases, showed bleb leakage after surgery. There were no intraoperative and postoperative complications related to ICG application. The application of ICG during trabeculectomy is a simple and useful technique to facilitate detection and repair of the bleb leakage.

  4. Growing barium hexaferrite (BaFe{sub 12}O{sub 19}) thin films using chemical solution deposition

    Energy Technology Data Exchange (ETDEWEB)

    Budiawanti, Sri, E-mail: awanty77@yahoo.com [Graduate Program of Materials Science, Department of Physics, FMIPA, Universitas Indonesia, Kampus UI Depok (Indonesia); Faculty of Teacher Training and Education, Sebelas Maret University (Indonesia); Soegijono, Bambang [Multiferroic Laboratory, Department of Physics, FMIPA, Universitas Indonesia, Kampus UI Depok (Indonesia)

    2016-04-19

    Barium hexaferrite (BaFe{sub 12}O{sub 19}, or simply known as BaM) thin films has been recognized as a potential candidate for microwave-based devices, magnetic recording media and data storage. To grow BaM thin films, chemical solution deposition is conducted using the aqueous solution of metal nitrates, which involves spin coatings on Si substrates. Furthermore, Thermal Gravimeter Analysis (TGA), X-Ray Diffractometer (XRD), Scanning Electron Microscopy (SEM) and Vibrating Sample Magnetometer (VSM) are applied to evaluate the decomposition behavior, structure, morphology, and magnetic properties of BaM thin films. Additionally, the effects of number of layers variation are also investigated. Finally, magnetic properties analysis indicates the isotropic nature of the films.

  5. Structural analysis of flavonoids in solution through DFT 1H NMR chemical shift calculations: Epigallocatechin, Kaempferol and Quercetin

    Science.gov (United States)

    De Souza, Leonardo A.; Tavares, Wagner M. G.; Lopes, Ana Paula M.; Soeiro, Malucia M.; De Almeida, Wagner B.

    2017-05-01

    In this work, we showed that comparison between experimental and theoretical 1H NMR chemical shift patterns, calculated using Density Functional Theory (DFT), can be used for the prediction of molecular structure of flavonoids in solution, what is experimentally accessible for gas phase (electron diffraction methods) and solid samples (X-ray diffraction). The best match between B3LYP/6-31G(d,p)-PCM 1H NMR calculations for B ring rotated structures and experimental spectra can provide information on the conformation adopted by polyphenols in solution (usually DMSO-d6, acetone-d6 as solvents), which may differ from solid state and gas phase observed structures, and also DFT optimized geometry in the vacuum.

  6. Chemical composition and electronic structure of the passive layer formed on stainless steels in a glucose-oxidase solution

    Energy Technology Data Exchange (ETDEWEB)

    Marconnet, C. [Laboratoire de Genie des Procedes et des Materiaux, Ecole Centrale Paris, Grande Voie des Vignes, 92290 CHATENAY-MALABRY (France)], E-mail: cyril.marconnet@yahoo.fr; Wouters, Y. [Science et Ingenierie des Materiaux et Procedes, Institut National Polytechnique de Grenoble, F-38402 Saint-Martin d' Heres Cedex (France); Miserque, F. [Laboratoire de Reactivite des Surfaces et des Interfaces, CEA Saclay, Bat. 391, 91191 GIF-SUR-YVETTE (France); Dagbert, C. [Laboratoire de Genie des Procedes et des Materiaux, Ecole Centrale Paris, Grande Voie des Vignes, 92290 CHATENAY-MALABRY (France)], E-mail: catherine.dagbert@ecp.fr; Petit, J.-P. [Laboratoire d' Electrochimie et de Physico-chimie des Materiaux et des Interfaces, INPG, F-38402 Saint-Martin d' Heres Cedex (France); Galerie, A. [Science et Ingenierie des Materiaux et Procedes, Institut National Polytechnique de Grenoble, F-38402 Saint-Martin d' Heres Cedex (France); Feron, D. [Service de Corrosion et du Comportement des Materiaux dans leur Environnement, CEA Saclay, Bat. 458, 91191 GIF-SUR-YVETTE (France)

    2008-12-01

    This article deals with the interaction between the passive layer formed on UNS S30403 and S31254 stainless steels and an enzymatic solution containing glucose oxidase (GOx) and its substrate D-glucose. This enzymatic solution is often used to reproduce in laboratory the ennoblement occuring in non-sterile aerated aqueous environments because of the biofilm settlement on the surface of the metallic material. GOx catalyses the oxidation of D-glucose to gluconic acid by reducing oxygen to hydrogen peroxide and produces an organic acid. Thanks to photocurrent measurements, XPS analysis and Mott-Schottky diagrams, it is here shown that such an environment generates modifications in the chemical composition and electronic structure of the passive layer: it induces a relative enrichment of the n-type semi-conducting phase containing chromium (chromine Cr{sub 2}O{sub 3}) and an increase of the donors density in the space charge region.

  7. Chemical composition and electronic structure of the passive layer formed on stainless steels in a glucose-oxidase solution

    International Nuclear Information System (INIS)

    Marconnet, C.; Wouters, Y.; Miserque, F.; Dagbert, C.; Petit, J.-P.; Galerie, A.; Feron, D.

    2008-01-01

    This article deals with the interaction between the passive layer formed on UNS S30403 and S31254 stainless steels and an enzymatic solution containing glucose oxidase (GOx) and its substrate D-glucose. This enzymatic solution is often used to reproduce in laboratory the ennoblement occuring in non-sterile aerated aqueous environments because of the biofilm settlement on the surface of the metallic material. GOx catalyses the oxidation of D-glucose to gluconic acid by reducing oxygen to hydrogen peroxide and produces an organic acid. Thanks to photocurrent measurements, XPS analysis and Mott-Schottky diagrams, it is here shown that such an environment generates modifications in the chemical composition and electronic structure of the passive layer: it induces a relative enrichment of the n-type semi-conducting phase containing chromium (chromine Cr 2 O 3 ) and an increase of the donors density in the space charge region

  8. Growing barium hexaferrite (BaFe_1_2O_1_9) thin films using chemical solution deposition

    International Nuclear Information System (INIS)

    Budiawanti, Sri; Soegijono, Bambang

    2016-01-01

    Barium hexaferrite (BaFe_1_2O_1_9, or simply known as BaM) thin films has been recognized as a potential candidate for microwave-based devices, magnetic recording media and data storage. To grow BaM thin films, chemical solution deposition is conducted using the aqueous solution of metal nitrates, which involves spin coatings on Si substrates. Furthermore, Thermal Gravimeter Analysis (TGA), X-Ray Diffractometer (XRD), Scanning Electron Microscopy (SEM) and Vibrating Sample Magnetometer (VSM) are applied to evaluate the decomposition behavior, structure, morphology, and magnetic properties of BaM thin films. Additionally, the effects of number of layers variation are also investigated. Finally, magnetic properties analysis indicates the isotropic nature of the films.

  9. Standard test methods for chemical, mass spectrometric, spectrochemical, nuclear, and radiochemical analysis of nuclear-grade plutonium nitrate solutions

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2010-01-01

    1.1 These test methods cover procedures for the chemical, mass spectrometric, spectrochemical, nuclear, and radiochemical analysis of nuclear-grade plutonium nitrate solutions to determine compliance with specifications. 1.2 The analytical procedures appear in the following order: Sections Plutonium by Controlled-Potential Coulometry Plutonium by Amperometric Titration with Iron(II) Plutonium by Diode Array Spectrophotometry Free Acid by Titration in an Oxalate Solution 8 to 15 Free Acid by Iodate Precipitation-Potentiometric Titration Test Method 16 to 22 Uranium by Arsenazo I Spectrophotometric Test Method 23 to 33 Thorium by Thorin Spectrophotometric Test Method 34 to 42 Iron by 1,10-Phenanthroline Spectrophotometric Test Method 43 to 50 Impurities by ICP-AES Chloride by Thiocyanate Spectrophotometric Test Method 51 to 58 Fluoride by Distillation-Spectrophotometric Test Method 59 to 66 Sulfate by Barium Sulfate Turbidimetric Test Method 67 to 74 Isotopic Composition by Mass Spectrom...

  10. Modification of chemical reactivity of enzymatic hydrolysis lignin by ultrasound treatment in dilute alkaline solutions.

    Science.gov (United States)

    Ma, Zhuoming; Li, Shujun; Fang, Guizhen; Patil, Nikhil; Yan, Ning

    2016-12-01

    In this study, we have explored various ultrasound treatment conditions for structural modification of enzymatic hydrolysis lignin (EHL) for enhanced chemical reactivity. The key structural modifications were characterized by using a combination of analytical methods, including, Fourier Transform-Infrared spectroscopy (FTIR), Proton Nuclear Magnetic Resonance ( 1 H NMR), Gel permeation chromatography (GPC), X-ray photoelectron spectroscopy (XPS), and Folin-Ciocalteu (F-C) method. Chemical reactivity of the modified EHL samples was determined by both 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity and their reactivity towards formaldehyde. It was observed that the modified EHL had a higher phenolic hydroxyl group content, a lower molecular weight, a higher reactivity towards formaldehyde, and a greater antioxidant property. The higher reactivity demonstrated by the samples after treatment suggesting that ultrasound is a promising method for modifying enzymatic hydrolysis lignin for value-added applications. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. Data solutions for the 21st century: CEFIC's vision and intentions. The European Chemical Industry Council.

    Science.gov (United States)

    Money, C D

    2001-02-01

    Information on workplace exposures to chemicals has a role and importance that goes beyond compliance with occupational exposure limits (OELs). In particular, the increasing use of exposure data in regulatory risk assessment processes places added demands on the need to collect such information. Industry's challenge is to respond to these developments in a manner that ensures data are obtained, archived, and analyzed to standards consistent with evolving stakeholder expectations.

  12. A robust, efficient and flexible method for staining myelinated axons in blocks of brain tissue.

    Science.gov (United States)

    Wahlsten, Douglas; Colbourne, Frederick; Pleus, Richard

    2003-03-15

    Previous studies have demonstrated the utility of the gold chloride method for en bloc staining of a bisected brain in mice and rats. The present study explores several variations in the method, assesses its reliability, and extends the limits of its application. We conclude that the method is very efficient, highly robust, sufficiently accurate for most purposes, and adaptable to many morphometric measures. We obtained acceptable staining of commissures in every brain, despite a wide variety of fixation methods. One-half could be stained 24 h after the brain was extracted and the other half could be stained months later. When staining failed because of an exhausted solution, the brain could be stained successfully in fresh solution. Relatively small changes were found in the sizes of commissures several weeks after initial fixation or staining. A half brain stained to reveal the mid-sagittal section could then be sectioned coronally and stained again in either gold chloride for myelin or cresyl violet for Nissl substance. Uncertainty, arising from pixelation of digitized images was far less than errors arising from human judgments about the histological limits of major commissures. Useful data for morphometric analysis were obtained by scanning the surface of a gold chloride stained block of brain with an inexpensive flatbed scanner.

  13. A novel low-temperature chemical solution route for straight and dendrite-like ZnO nanostructures

    International Nuclear Information System (INIS)

    Zhang Hui; Du Ning; Wu Jianbo; Ma, Xiangyang; Yang Deren; Zhang Xiaobin; Yang Zhiqing

    2007-01-01

    The straight and dendrite-like growths of ZnO have been completely and simply controlled by the status of ZnO seed instead of surfactant, template, oriented attachment, and ZnO buffer layer on the substrate in the chemical reaction synthesis of ZnO nanostructures. The monodisperse ZnO seeds, which are prepared by in situ quickly injecting the cool mixed zinc acetate and potassium hydrate ethanol solution into the hot matrix aqueous solution of zinc nitrate hydrate and diethylenetriamine at 95 deg. C, improve the straight growth and lots of uniform, straight, and single-crystalline ZnO nanorods with about 20-30 nm in diameter and 300 nm in length are achieved. While, the aggregated ZnO seeds, which are prepared by dropwise adding potassium hydrate ethanol solution into zinc acetate ethanol solution at 60 deg. C for 3 h, result in the dendrite-like growth and the bur-like ZnO nanostructures consisting of hundreds of nanorods with about 30-50 nm in diameter and several micrometers in length are formed. Furthermore, the approach presented here provides a simple, low-cost, environmental-friendly and high efficiency route to synthesize the high quality ZnO nanorods and bur-like ZnO nanostructures

  14. [Chemical destruction of the prostate by Prostalyser-1 and Prostalyser-2 solutions: an experimental study in dogs].

    Science.gov (United States)

    Shioshvili, T I; Chokhonelidze, G Z; Shulaia, Ts A; Kazaishvili, E D; Gogoladze, T V

    2005-01-01

    The aim of the study was elaboration of a new minimally invasive but effective alternative method of BPH treatment. The experiments were carried out on 46 male dogs divided into two equal groups. 10 ml of Prostalyser-1 solution (natrii chloridi 9.5 g, dimethylsulfoxidi 0.5 g, aquae destill. Ad 1000.0 g) was given in a single injection into the prostates of the first group of animals. The same volume of Prostalyser-2 solution (spiritus ethilicus 96% - 76.5 g, DMSO 0.5 g, aq.destill ad 100.0 g)--into the prostates of the other group, respectively. The temperature of the solutions was +80 degrees C. Within the first 2 months, essential disorders were observed in the cellular Na-pump, membrane permeability system, there were lobular and diffusive necroses in prostatic alveolar epithelium and a decrease of the prostate weight by 68-66%. This condition of the prostate persisted for 4-6 months. Prostalyser-1 and Prostalyser-2 solutions can be recommended as very prospective substances for chemical destruction of the prostate in case of BPH.

  15. Spectral analysis and quantum chemical studies of chair and twist-boat conformers of cycloheximide in gas and solution phases

    Science.gov (United States)

    Tokatli, A.; Ucun, F.; Sütçü, K.; Osmanoğlu, Y. E.; Osmanoğlu, Ş.

    2018-02-01

    In this study the conformational behavior of cycloheximide in the gas and solution (CHCl3) phases has theoretically been investigated by spectroscopic and quantum chemical properties using density functional theory (wB97X-D) method with 6-31++G(d,p) basis set, for the first time. The calculated IR results reveal that in the ground state the molecule exits as a mixture of the chair and twist-boat conformers in the gas phase, while the calculated NMR results reveal that it only exits as the chair conformer in the solution phase. In order to obtain the contributions coming from intramolecular interactions to the stability of the conformers in the gas and solution phases, the quantum theory of atoms in molecules (QTAIM), noncovalent interactions (NCI) method, and natural bond orbital analysis (NBO) have been employed. The QTAIM and NCI methods indicated that by intramolecular interactions with bond critical point (BCP) the twist-boat conformer is more stabilized than the chair conformer, while by steric interactions it is more destabilized. Considering that these interactions balance each other, the stabilities of the conformers are understood to be dictated by the van der Waals interactions. The NBO analyses show that the hyperconjugative and steric effects play an important role in the stabilization in the gas and solution phases. Furthermore, to get a better understanding of the chemical behavior of this important antibiotic drug we have evaluated and, commented the global and local reactivity descriptors of the both conformers. Finally, the EPR analysis of γ-irradiated cycloheximide has been done. The comparison of the experimental and calculated data have showed the inducement of a radical structure of (CH2)2ĊCH2 in the molecule. The experimental EPR spectrum has also confirmed that the molecule simultaneously exists in the chair and twist-boat conformers in the solid phase.

  16. Influence of chemical disorder on energy dissipation and defect evolution in concentrated solid solution alloys

    International Nuclear Information System (INIS)

    Zhang, Yanwen; Wang, Lumin; Caro, Alfredo; Weber, William J.; Univ. of Tennessee, Knoxville, TN

    2015-01-01

    A long-standing objective in materials research is to understand how energy is dissipated in both the electronic and atomic subsystems in irradiated materials, and how related non-equilibrium processes may affect defect dynamics and microstructure evolution. Here we show that alloy complexity in concentrated solid solution alloys having both an increasing number of principal elements and altered concentrations of specific elements can lead to substantial reduction in the electron mean free path and thermal conductivity, which has a significant impact on energy dissipation and consequentially on defect evolution during ion irradiation. Enhanced radiation resistance with increasing complexity from pure nickel to binary and to more complex quaternary solid solutions is observed under ion irradiation up to an average damage level of 1 displacement per atom. Understanding how materials properties can be tailored by alloy complexity and their influence on defect dynamics may pave the way for new principles for the design of radiation tolerant structural alloys

  17. Optimization and analysis of large chemical kinetic mechanisms using the solution mapping method - Combustion of methane

    Science.gov (United States)

    Frenklach, Michael; Wang, Hai; Rabinowitz, Martin J.

    1992-01-01

    A method of systematic optimization, solution mapping, as applied to a large-scale dynamic model is presented. The basis of the technique is parameterization of model responses in terms of model parameters by simple algebraic expressions. These expressions are obtained by computer experiments arranged in a factorial design. The developed parameterized responses are then used in a joint multiparameter multidata-set optimization. A brief review of the mathematical background of the technique is given. The concept of active parameters is discussed. The technique is applied to determine an optimum set of parameters for a methane combustion mechanism. Five independent responses - comprising ignition delay times, pre-ignition methyl radical concentration profiles, and laminar premixed flame velocities - were optimized with respect to thirteen reaction rate parameters. The numerical predictions of the optimized model are compared to those computed with several recent literature mechanisms. The utility of the solution mapping technique in situations where the optimum is not unique is also demonstrated.

  18. System and method for laser assisted sample transfer to solution for chemical analysis

    Science.gov (United States)

    Van Berkel, Gary J; Kertesz, Vilmos

    2014-01-28

    A system and method for laser desorption of an analyte from a specimen and capturing of the analyte in a suspended solvent to form a testing solution are described. The method can include providing a specimen supported by a desorption region of a specimen stage and desorbing an analyte from a target site of the specimen with a laser beam centered at a radiation wavelength (.lamda.). The desorption region is transparent to the radiation wavelength (.lamda.) and the sampling probe and a laser source emitting the laser beam are on opposite sides of a primary surface of the specimen stage. The system can also be arranged where the laser source and the sampling probe are on the same side of a primary surface of the specimen stage. The testing solution can then be analyzed using an analytical instrument or undergo further processing.

  19. Study of the chemical interactions of actinide cations in solution at macroscopic concentrations

    International Nuclear Information System (INIS)

    Maurice, C.

    1983-01-01

    The aim of this work was to study the interactions of pentavalent neptunium in dodecane-diluted tributyl phosphate with other metallic cations, especially uranium VI and ruthenium present in reprocessing solutions. Pentavalent neptunium on its own was shown to exist in several forms complexed by water and TBP and also to dimerise. In the complex it forms with uranium VI the interaction via the neptunyl oxygen is considerably enhanced in organic solution. Dibutyl phosphoric acid strengthens the interaction between neptunium and uranium. The Np V-ruthenium interaction reveals the existence of a new cation-cation complex; the process takes place in two successive stage and leads to the formation, reinforced and accelerated by HDBP, of a highly to the formation, reinforced and accelerated by HDBP, of a highly stable complex. These results contribute towards a better knowledge of the behaviour of neptunium in the reprocessing operation [fr

  20. Action of acoustical oscillations and hydrodynamic factors on the chemical activity of iodne in solution

    International Nuclear Information System (INIS)

    Nikolaev, L.A.; Fadeev, G.N.

    1984-01-01

    Investigation results on the effect of acoustic oscillations within the frequency range of 1-500 Hz on aqueous iodine solutions and dark blue iodide-starch complex have been presented. Experiments were carried out within the range of action of acoustical and hydrodynamic oscillations without visual formation of bubbles. Form of kinetic dependences corresponds to the first order reaction in respect to iodine. Sharp increase of solution electric conductivity and noticeable increase of medium acidity were observed after the action of oscillations. It has been shown that low-frequency oscillations strengthen iodine hydrolysis and lead to iodate atom formation. Effect of oscillations with 25-30 Hz upon the iodide-starch complex results in the complex destruction, i. e. iodide atom chains removal out of clathrate starch cavities. Formation of iodide-starch complexes is promoted under the action of 250 Hz frequency, as such oscillations lead to the change of starch structure, but do not effect upon iodide

  1. Optimal Contrast Agent Staining of Ligaments and Tendons for X-Ray Computed Tomography.

    Science.gov (United States)

    Balint, Richard; Lowe, Tristan; Shearer, Tom

    2016-01-01

    X-ray computed tomography has become an important tool for studying the microstructures of biological soft tissues, such as ligaments and tendons. Due to the low X-ray attenuation of such tissues, chemical contrast agents are often necessary to enhance contrast during scanning. In this article, the effects of using three different contrast agents--iodine potassium iodide solution, phosphotungstic acid and phosphomolybdic acid--are evaluated and compared. Porcine anterior cruciate ligaments, patellar tendons, medial collateral ligaments and lateral collateral ligaments were used as the basis of the study. Three samples of each of the four ligament/tendon types were each assigned a different contrast agent (giving a total of twelve samples), and the progression of that agent through the tissue was monitored by performing a scan every day for a total period of five days (giving a total of sixty scans). Since the samples were unstained on day one, they had been stained for a total of four days by the time of the final scans. The relative contrast enhancement and tissue deformation were measured. It was observed that the iodine potassium iodide solution penetrated the samples fastest and caused the least sample shrinkage on average (although significant deformation was observed by the time of the final scans), whereas the phosphomolybdic acid caused the greatest sample shrinkage. Equations describing the observed behaviour of the contrast agents, which can be used to predict optimal staining times for ligament and tendon X-ray computed tomography, are presented.

  2. Evaluations of photo-solution chemical behaviors of Pu and Np

    International Nuclear Information System (INIS)

    Wada, Yukio; Morimoto, Kyouichi; Tomiyasu, Hiroshi.

    1995-01-01

    A photochemical method of removing Np from a mixture of nitric acid solutions of Pu and Np has been studied in connection with the Purex reprocessing procedure. From these experiments, we confirmed the potential of the photochemical valency adjustment technology as an advanced reprocessing one. Furthermore, the applicability of the installation for the process and the mechanism of photochemical reactions from the standpoint of thermodynamic considerations were discussed. (author)

  3. Staining of proteins in gels with Coomassie G-250 without organic solvent and acetic acid.

    Science.gov (United States)

    Lawrence, Ann-Marie; Besir, H Uuml Seyin

    2009-08-14

    In classical protein staining protocols using Coomassie Brilliant Blue (CBB), solutions with high contents of toxic and flammable organic solvents (Methanol, Ethanol or 2-Propanol) and acetic acid are used for fixation, staining and destaining of proteins in a gel after SDS-PAGE. To speed up the procedure, heating the staining solution in the microwave oven for a short time is frequently used. This usually results in evaporation of toxic or hazardous Methanol, Ethanol or 2-Propanol and a strong smell of acetic acid in the lab which should be avoided due to safety considerations. In a protocol originally published in two patent applications by E.M. Wondrak (US2001046709 (A1), US6319720 (B1)), an alternative composition of the staining solution is described in which no organic solvent or acid is used. The CBB is dissolved in bidistilled water (60-80 mg of CBB G-250 per liter) and 35 mM HCl is added as the only other compound in the staining solution. The CBB staining of the gel is done after SDS-PAGE and thorough washing of the gel in bidistilled water. By heating the gel during the washing and staining steps, the process can be finished faster and no toxic or hazardous compounds are evaporating. The staining of proteins occurs already within 1 minute after heating the gel in staining solution and is fully developed after 15-30 min with a slightly blue background that is destained completely by prolonged washing of the stained gel in bidistilled water, without affecting the stained protein bands.

  4. EFFECT OF STABILIZERS ON THE CHEMICAL AND PHOTODEGRADATION OF ASCORBIC ACID IN AQUEOUS SOLUTION

    Directory of Open Access Journals (Sweden)

    Iqbal Ahmad

    2016-06-01

    Full Text Available Ascorbic acid (vitamin C is susceptible to light and air and forms various degradation products. A number of stabilizers have been used to study their effect on the degradation of ascorbic acid (AH2 in dark and light at pH 4.0 and 6.0 alone and in combination with citric and tartaric acids. The assay of AH2 in degraded solutions was performed by a specific UV spectrometric method. The degradation product of AH2 at pH 4.0 and 6.0 was identified as dehydroascorbic acid. The degradation of AH2 has been found to follow first-order kinetics. The apparent first-order rate constants, t90 and percent inhibition in rate in the presence of stabilizers and the second-order rate constants for the interaction of stabilizers with AH2 have been determined. The highest stabilizing effect on AH2 was found by sodium metabisulfite, followed by sodium sulfite, sodium bisulfate, sodium thiosulfate and thiourea. The pH of the solutions has also been found to influence the degradation of AH2 as the rates are higher at pH 6.0 compared to those of pH 4.0, probably due to the ionization of AH2. A synergistic effect has been observed when citric or tartaric acid was added to the solutions containing stabilizers where citric acid showed comparatively better effect.

  5. Improved removal of malachite green from aqueous solution using chemically modified cellulose by anhydride.

    Science.gov (United States)

    Zhou, Yanmei; Min, Yinghao; Qiao, Han; Huang, Qi; Wang, Enze; Ma, Tongsen

    2015-03-01

    Cellulose modified with maleic (M) and phthalic (P) anhydride, to be named CMA and CPA, were tested as feasible adsorbents for the removal of malachite green from aqueous solution. At the same time, the uptake ability of natural cellulose was also studied for comparison. The structure of material was characterized by FT-IR and XRD. The effects of solution pH, initial dye concentration, contact time and temperature were investigated in detail by batch adsorption experiments. The kinetic and isotherm studies suggested that the adsorption followed the pseudo-second-order model and Langmuir isotherm. The maximum adsorption capacity on CMA and CPA were 370 mg g(-1) and 111 mg g(-1), respectively. Furthermore, the thermodynamics studies indicated the spontaneous nature of adsorption of malachite green on adsorbents. All the studied results showed that the modified cellulose could be used as effective adsorption material for the removal of malachite green from aqueous solutions. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. Coupling between solute transport and chemical reactions models. Acoplamiento de modelos de transporte de solutos y de modelos de reacciones quimicas

    Energy Technology Data Exchange (ETDEWEB)

    Samper, J.; Ajora, C. (Instituto de Ciencias de la Tierra, CSIC, Barcerlona (Spain))

    1993-01-01

    During subsurface transport, reactive solutes are subject to a variety of hydrodynamic and chemical processes. The major hydrodynamic processes include advection and convection, dispersion and diffusion. The key chemical processes are complexation including hydrolysis and acid-base reactions, dissolution-precipitation, reduction-oxidation, adsorption and ion exchange. The combined effects of all these processes on solute transport must satisfy the principle of conservation of mass. The statement of conservation of mass for N mobile species leads to N partial differential equations. Traditional solute transport models often incorporate the effects of hydrodynamic processes rigorously but oversimplify chemical interactions among aqueous species. Sophisticated chemical equilibrium models, on the other hand, incorporate a variety of chemical processes but generally assume no-flow systems. In the past decade, coupled models accounting for complex hydrological and chemical processes, with varying degrees of sophistication, have been developed. The existing models of reactive transport employ two basic sets of equations. The transport of solutes is described by a set of partial differential equations, and the chemical processes, under the assumption of equilibrium, are described by a set of nonlinear algebraic equations. An important consideration in any approach is the choice of primary dependent variables. Most existing models cannot account for the complete set of chemical processes, cannot be easily extended to include mixed chemical equilibria and kinetics, and cannot handle practical two and three dimensional problems. The difficulties arise mainly from improper selection of the primary variables in the transport equations. (Author) 38 refs.

  7. Compendium of shock wave data. Section C. Organic compounds excluding hydrocarbons. Section D. Mixtures. Section E. Mixtures and solutions without chemical characterization. Compendium index

    International Nuclear Information System (INIS)

    van Thiel, M.; shaner, J.; Salinas, E.

    1977-06-01

    This volume lists thermodynamic data for organic compounds excluding hydrocarbons, mixtures, and mixtures and solutions without chemical characterization. Alloys and some minerals are included among the mixtures. This volume also contains the index for the three-volume compendium

  8. Borax methylene blue: a spectroscopic and staining study.

    Science.gov (United States)

    Donaldson, P T; Russo, A; Reynolds, C; Lillie, R D

    1978-07-01

    Borax methylene blue is quite stable at room temperatures of 22-25 C. At 30 C polychroming is slow; during 50 days in a water bath at this temperature the absorption peak moves from 665 to 656 nm. At 35 C, the absorption peak reaches 660 nm in 7 days, 654 nm in 14. At 60 C polychroming is rapid, the absorption peak reaching 640-620 nm in 3 days. When the pH of the borax methylene blue solutions, normally about 9.0, is adjusted to pH 6.5, the absorption peak remains at 665 nm even when incubated at 60 C for extended periods. When used as a blood stain 0.4 ml borax methylene blue (1% methylene blue in 1% borax), 4 ml acetone, 2 ml borax-acid phosphate buffer to bring the solution to pH 6.5, and distilled water to make 40 ml, with 0.2 ml 1% eosin added just before using, an excellent Nocht-Giemsa type stain is achieved after 30 minutes staining. The material plasmodia P. falciparum, P. vivax, and P. berghei stain moderate blue with dark red chromatin and green to black pigment granules. The study confirms Malachowski's 1891 results and explains Gautier's 1896-98 failure to duplicate it.

  9. INNOVATIVE SOLUTIONS IN BIOTECHNOLOGIES OF COMBINED YOGURT DRINKS WITH BALANCED CHEMICAL CONTENTS

    Directory of Open Access Journals (Sweden)

    N. A. Tkachenko

    2017-10-01

    Full Text Available Expediency of development of recipes and innovative biotechnologies for combined milk-vegetational products with balanced chemical composition, strengthened probiotic properties and extended shelf life was proven in field of establishing proper diet for adult healthy people, both in everyday consumption and during treatment of illnesses and rehabilitation after it. Principles of scientific approach to creation of biotechnologies for fermented combined products with balance of basic food nutrients are described here, as well as innovative biotechnological approaches, which provide the possibility of getting desired products (yoghurt drinks with high probiotic properties and long shelf life. Main stages of development are described for recipes and biotechnologies of bifido-enabled combined yoghurt drinks with balanced chemical composition, rich on lively bifido- and Lactobacterium cells and long shelf life. A scheme for production of desired products with explanation of technological process parameters is provided, it was tested in industrial conditions at “Gormolzavod №1” Ltd. in Odesa, Ukraine. In samples of milk-rice and milk-spelt yoghurt drinks, which were produced in industrial conditions, we determined chemical composition and primary quality objectives. Desired products have balanced ratio of proteins : fats : carbohydrates (1 : 1 : 4, high sensory qualities, standard quality values during long shelf life (20 days in sealed tare, contain a high concentration of viable cells of probiotic cultures – such as B. animalis Bb-12 (not less than 3.6∙108 CFU / cm3 and mixed cultures of L. bulgaricus + S. thermophilus (not less than 4.0∙108 CFU/cm3, as well as physiologically significant number of prebiotics – lactulose and fiber (30 and 10%, according to the daily consumption norm when consuming 500 cm3 of product.

  10. Chemical dosimetry using an iodide/iodate aqueous solution: application to the gamma irradiation of blood

    Energy Technology Data Exchange (ETDEWEB)

    Rahn, Ronald O. E-mail: rahnr@ms.soph.uab.edu

    2003-01-01

    A method is presented for measuring and verifying the radiation dose in gamma irradiators used for treating blood prior to transfusion. This method employs the iodide/iodate dosimeter (0.6 M iodide, 0.1 M iodate, and 0.01 borate at pH 9.25) which forms triiodide upon exposure to ionizing radiation; for Cs-137 radiation the G value is 14.1. Samples were placed in a canister and irradiated in a conventional blood bank irradiator containing several Cs-137 sources. The following were exposed: (a) nine 1.5 ml plastic tubes containing dosimetry solution taped inside a 250 ml blood bag, which, in turn, was filled with either water or blood, (b) 50 ml plastic syringes containing varying amounts of dosimetry solution, (c) a whole blood bag containing 250 ml of the dosimetry solution. A water phantom was not used during exposure. The absorbance changes at 352 nm due to triiodide formation were used to determine a dose rate, which was on the order of 10 Gy/min ({+-}5%) for all samples measured. This value is consistent with an average time-decayed dose rate for the irradiation volume as determined from the manufacturers calibration of the unit taking into account the heterogeneous nature of the radiation field inside the irradiator and the absence of a water phantom. Because of its sensitivity, ease of operation, and reproducibility, it is suggested that the iodide/iodate dosimetry system be considered for on-site periodic conformation/verification of the radiation dose as part of a quality assurance requirement for blood irradiators.

  11. Chemical dosimetry using an iodide/iodate aqueous solution: application to the gamma irradiation of blood

    International Nuclear Information System (INIS)

    Rahn, Ronald O.

    2003-01-01

    A method is presented for measuring and verifying the radiation dose in gamma irradiators used for treating blood prior to transfusion. This method employs the iodide/iodate dosimeter (0.6 M iodide, 0.1 M iodate, and 0.01 borate at pH 9.25) which forms triiodide upon exposure to ionizing radiation; for Cs-137 radiation the G value is 14.1. Samples were placed in a canister and irradiated in a conventional blood bank irradiator containing several Cs-137 sources. The following were exposed: (a) nine 1.5 ml plastic tubes containing dosimetry solution taped inside a 250 ml blood bag, which, in turn, was filled with either water or blood, (b) 50 ml plastic syringes containing varying amounts of dosimetry solution, (c) a whole blood bag containing 250 ml of the dosimetry solution. A water phantom was not used during exposure. The absorbance changes at 352 nm due to triiodide formation were used to determine a dose rate, which was on the order of 10 Gy/min (±5%) for all samples measured. This value is consistent with an average time-decayed dose rate for the irradiation volume as determined from the manufacturers calibration of the unit taking into account the heterogeneous nature of the radiation field inside the irradiator and the absence of a water phantom. Because of its sensitivity, ease of operation, and reproducibility, it is suggested that the iodide/iodate dosimetry system be considered for on-site periodic conformation/verification of the radiation dose as part of a quality assurance requirement for blood irradiators

  12. Neptunium carbonato complexes in aqueous solution: an electrochemical, spectroscopic, and quantum chemical study.

    Science.gov (United States)

    Ikeda-Ohno, Atsushi; Tsushima, Satoru; Takao, Koichiro; Rossberg, André; Funke, Harald; Scheinost, Andreas C; Bernhard, Gert; Yaita, Tsuyoshi; Hennig, Christoph

    2009-12-21

    The electrochemical behavior and complex structure of Np carbonato complexes, which are of major concern for the geological disposal of radioactive wastes, have been investigated in aqueous Na(2)CO(3) and Na(2)CO(3)/NaOH solutions at different oxidation states by using cyclic voltammetry, X-ray absorption spectroscopy, and density functional theory calculations. The end-member complexes of penta- and hexavalent Np in 1.5 M Na(2)CO(3) with pH = 11.7 have been determined as a transdioxo neptunyl tricarbonato complex, [NpO(2)(CO(3))(3)](n-) (n = 5 for Np(V), and 4 for Np(VI)). Hence, the electrochemical reaction of the Np(V/VI) redox couple merely results in the shortening/lengthening of bond distances mainly because of the change of the cationic charge of Np, without any structural rearrangement. This explains the observed reversible-like feature on their cyclic voltammograms. In contrast, the electrochemical oxidation of Np(V) in a highly basic carbonate solution of 2.0 M Na(2)CO(3)/1.0 M NaOH (pH > 13) yielded a stable heptavalent Np complex of [Np(VII)O(4)(OH)(2)](3-), indicating that the oxidation reaction from Np(V) to Np(VII) in the carbonate solution involves a drastic structural rearrangement from the transdioxo configuration to a square-planar-tetraoxo configuration, as well as exchanging the coordinating anions from carbonate ions (CO(3)(2-)) to hydroxide ions (OH(-)).

  13. Physico-chemical stability of busulfan in injectable solutions in various administration packages.

    Science.gov (United States)

    Houot, Mélanie; Poinsignon, Vianney; Mercier, Lionel; Valade, Cyril; Desmaris, Romain; Lemare, François; Paci, Angelo

    2013-03-01

    Busulfan is used as part of a conditioning regimen prior to hematopoietic stem cell transplantation for the treatment of certain cancers and immune deficiency syndromes. Due to its instability in aqueous preparations, busulfan for infusion is prepared from a concentrate and has a relatively short shelf life once prepared. The purpose of this study was to identify the most suitable storage container and temperature to maximize the shelf life of busulfan therapeutic infusions prepared from Busilvex(®). Busilvex(®) 6 mg/mL was diluted to 0.55 mg/mL with 0.9 % NaCl and aliquots dispensed into polypropylene syringes, polyvinyl chloride bags, and glass bottles. Three storage temperatures were evaluated: 2-8 °C, 13-15 °C (thermostatically controlled chamber), and room temperature (20 ± 5 °C). At set time points, samples were analysed for busulfan content, using a high-performance liquid chromatography (HPLC) system with ultraviolet detection. The change in pH and osmolarity on storage was also determined, and solutions were inspected visually for formation of a precipitate or colour change. To determine the contribution of precipitation to loss of busulfan content on storage, samples from one time series were treated with the solvent dimethylacetamide prior to HPLC separation and quantitation of busulfan. The results of the active substance content monitoring study over a 48-h period demonstrate that busulfan solution is stable at a 5 % threshold, at 2-8 °C for 16 h in syringes, 14 h in glass bottles, and 6 h in bags. In addition, the period of stability decreases as the temperature increases (4 h at 20 ± 5 °C). The solution is considered to be stable, subject to precipitation liable to be observed regardless of the temperature. The best stability was observed for busulfan solutions placed at 2-8 °C in syringes. This study demonstrated that precipitation, in addition to hydrolysis, has a significant influence on the busulfan content.

  14. Colloidal copper in aqueous solutions: radiation-chemical reduction, mechanism of formation and properties

    International Nuclear Information System (INIS)

    Ershov, B.G.

    1994-01-01

    Colloidal copper was obtained upon γ-irradiation of aqueous solutions of divalent copper perchlorate in the presence of alcohol and polyethyleneimine (PEI). The sols were in the form of spherical particles 4 nm in diameter, which were promptly oxidized by oxygen or other oxidants. The copper ions were reduced on the surface of silver sols. The optical parameters of the obtained bimetallic particles were studied. The copper ions led to the broadening and shift of the absorption bands of the silver sols to the UV region

  15. Influence of lanthanum on the physico-chemical properties of solid solutions GeS0.5Se0.5

    International Nuclear Information System (INIS)

    Murquzov, M.I.; Alekperov, A.S.; Bayramov, R.B.

    2010-01-01

    By the methods of physical-chemical analysis (X-ray, MSA, as well as measurement of microhardness and density determination) the influence of La on the physico-chemical properties of solid solutions (GeS 0 .5Se 0 .5) 1 -x(La) x was studied and its microdiagram was plotted. At room temperature the GeS 0 .5Se 0 .5 based solid solution extent 4 at. percent of La. The dependence of lanthane microhardness was studied

  16. Growth and characterization of yttrium iron garnet films on Si substrates by Chemical Solution Deposition (CSD) technique

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Xin; Chen, Ying; Wang, Genshui [Key Laboratory of Inorganic Function Materials and Devices, Shanghai Institute of Ceramics, Chinese Academy of Sciences, University of Chinese Academy of Sciences, 1295 Dingxi Rd., Shanghai 200050 (China); Zhang, Yuanyuan [Key Laboratory of Polar Materials and Devices, Ministry of Education, Department of Electronic Engineering, East China Normal University, 500 Dongchuan Rd., Shanghai 200241 (China); Ge, Jun [Key Laboratory of Inorganic Function Materials and Devices, Shanghai Institute of Ceramics, Chinese Academy of Sciences, University of Chinese Academy of Sciences, 1295 Dingxi Rd., Shanghai 200050 (China); Tang, Xiaodong [Key Laboratory of Polar Materials and Devices, Ministry of Education, Department of Electronic Engineering, East China Normal University, 500 Dongchuan Rd., Shanghai 200241 (China); Ponchel, Freddy; Rémiens, Denis [Institute of Electronics, Microelectronics and Nanotechnology (IEMN)–DOAE, UMR CNRS 8520, Université des Sciences et Technologies de Lille, 59652 Villeneuve d’Ascq Cedex (France); Dong, Xianlin, E-mail: xldong@mail.sic.ac.cn [Key Laboratory of Inorganic Function Materials and Devices, Shanghai Institute of Ceramics, Chinese Academy of Sciences, University of Chinese Academy of Sciences, 1295 Dingxi Rd., Shanghai 200050 (China)

    2016-06-25

    Yttrium Iron Garnet (YIG) films were prepared on Si substrates by Chemical Solution Deposition (CSD) technique using acetic acid and deionized water as solvents. Well-crystallized and crack-free YIG films were obtained when annealed at 750 °C and 850 °C respectively, showing a low surface roughness of several nanometers. When annealed at 750 °C for 30 min, the saturated magnetization (Ms) and coercive field (Hc) of YIG films were 0.121 emu/mm{sup 3} (4πMs = 1.52 kGs) and 7 Oe respectively, which were similar to that prepared by PLD technique. The peak-to-peak linewidth of ferromagnetic resonance (FMR) was 220 Oe at 9.10 GHz. The results demonstrated that CSD was an excellent technique to prepare high quality yttrium iron garnet (YIG) films on silicon, which could provide a lower-cost way for large-scale production on Si-based integrated devices. - Highlights: • The preparation of YIG films by Chemical Solution Deposition are demonstrated. • Well-crystallized and crack-free YIG films can be obtained on Si substrate by CSD. • YIG films can be crystallized in 750 °C with good magnetic performances. • It's beneficial to large-scale production of YIG films on Si integrated devices.

  17. Chemical interaction of potassium diphosphate with cadmium nitrate in aqueous solution

    International Nuclear Information System (INIS)

    Kokhanovskij, V.V.

    1993-01-01

    Formation of low-soluble compounds in 1.5 mol/l isomolar cross section of K 4 P 2 O 7 -Cd(NO 3 ) 2 -H 2 O system was studied. Liquid phases are studied by the methods of refractometry and pH value measuring, an solid ones - by the methods of chemical and X-ray phase analysis, IR spectroscopy, chromatography and microscopy. Three individual chemical compounds K 2 CdP 2 O 7 x 4H 2 O, K 2 Cd 3 (P 2 O 7 ) 2 x 3H 2 O and Cd 2 P 2 O 7 x 3.5H 2 O and some their mixtures were isolated and investigated. It is shown that doulble diphosphate K 6 Cd(P 2 O 7 ) 2 x 6H 2 O does not precipitate spontanously, but instead of it in wide region of system K 2 CdP 2 O 7 x 4H 2 O crystallizes as elongated acicular crystals or as thin plates of improper form

  18. Effect of ethylenediamine on chemical degradation of insulin aspart in pharmaceutical solutions.

    Science.gov (United States)

    Poulsen, Christian; Jacobsen, Dorte; Palm, Lisbeth

    2008-11-01

    To examine the effect of different amine compounds on the chemical degradation of insulin aspart at pharmaceutical formulation conditions. Insulin aspart preparations containing amine compounds or phosphate (reference) were prepared and the chemical degradation was assessed following storage at 37 degrees C using chromatographic techniques. Ethylenediamine was examined at multiple concentrations and the resulting insulin-ethylenediamine derivates were structurally characterized using matrix assisted laser desorption ionization time-of-flight mass spectroscopy. The effects on ethylenediamine when omitting glycerol or phenolic compounds from the formulations were investigated. Ethylenediamine was superior in terms of reducing formation of high molecular weight protein and insulin aspart related impurities compared to the other amine compounds and phosphate. Monotransamidation of insulin aspart in the presence of ethylenediamine was observed at all of the six possible Asn/Gln residues with Asn(A21) having the highest propensity to react with ethylenediamine. Data from formulations studies suggests a dual mechanism of ethylenediamine and a mandatory presence of phenolic compounds to obtain the effect. The formation of high molecular weight protein and insulin aspart related impurities was reduced by ethylenediamine in a concentration dependant manner.

  19. Comparison of Electrocoagulation and Chemical Coagulation Processes in Removing Reactive red 196 from Aqueous Solution

    Directory of Open Access Journals (Sweden)

    Ali Assadi

    2016-06-01

    Full Text Available Background: Conventional chemical coagulation is considered as an old method to dye and COD removal in textile effluent. Electrocoagulation (EC process is a robust method to achieve maximum removal. Methods: This study was designed to compare the result of operational parameters including optimum pH and coagulant concentration for chemical coagulation with ferric chloride and alum also, voltage, electrolysis time, initial pH, and conductivity for EC with iron electrodes to remove reactive red 196 (RR 196. Results: The outcomes show that ferric chloride and alum at optimum concentration were capable of removing dye and COD by 79.63 % and 84.83% and 53% and 55%, respectively. In contrast, EC process removed the dye and COD by 99.98% and 90.4%, respectively. Conclusion: The highest treatment efficiency was obtained by increasing the voltage, electrolysis time, pH and conductivity. Increase initial dye concentration reduces removal efficiency. Ultimately, it could be concluded that EC technology is an efficient procedure for handling of colored industrial wastewaters.

  20. Experimental Study of the Effect for Water Depth on the Mass Transfer of Passive Solar Still Chemical Solutions

    Directory of Open Access Journals (Sweden)

    Fayadh M. Abed

    2018-01-01

    Full Text Available An experimental study on a passive solar distiller in the Tikrit city on (latitude line"34 36o north, longitude line "45 43o east, and purpose of that study to raise the efficiency and productivity of the solar distiller. And then design the monoclinic solar distiller and add reflector plate and a solar concentrate. The Practical tests were conducted at a rate of every half-hour from the beginning of February to the beginning of the month of June. The study began by comparing the solar distiller that contain the concentrates and without contain it. Then study the influence of adding coal and chemical solutions, like blue Thymol solution and blue bromophenol solution to see the additions effect on the productivity and efficiency of distiller, and also The study was conducted to see the effect of the water depth on the productivity of distiller with take four water depths within the basin are (2,1.5,1,0.5 cm of water. The tests were conducted in weather conditions close. and the results of the study, That distilled added his concentrates improved its productivity by 46% and efficiency increases 43% with non-use of concentrates, and coal increased efficiency by 36% and productivity improved up to 38%, the addition of  blue Thymol solution increases the efficiency by 19% and productivity by 16%, as well as bromophenol solution  increase productivity by 23% and improve efficiency by 25%, when comparing the additions found that the best one is coal. Through the study of the depth of the water show that increases productivity and efficiency by reducing the depth of the water in the basin distiller. DOI: http://dx.doi.org/10.25130/tjes.24.2017.13

  1. Behavior of Paramecium sp. in solutions containing Sr and Pb: Do Paramecium sp. alter chemical forms of those metals?

    International Nuclear Information System (INIS)

    Kozai, Naofumi; Ohnuki, Toshihiko; Koka, Masahi; Satoh, Takahiro; Kamiya, Tomihiro

    2011-01-01

    The behavior of Paramecium sp. (Paramecium bursaria) in aqueous solutions containing Sr and Pb was investigated to determine the role of protozoa in the migration of radionuclides in the environment. Precultured living cells of P. bursaria were exposed to aqueous solutions containing 0.01 or 0.05 mM Sr or Pb at pH 7 for 24 h. For comparison, pre-killed cells were treated with the metal solutions in the same way. Two-dimensional elemental mappings of cells were obtained by micro-PIXE. Aquatic species of Sr and Pb were analyzed by size exclusion chromatography (SEC) coupled online to ultraviolet (UV) spectroscopy and inductivity coupled plasma mass spectroscopy (ICP-MS). The amounts of Sr adsorbed or taken up by the cells surviving for 24 h and adsorbed on pre-killed cells were below the detection limit. Cells of P. bursaria adsorbed or took up a fraction of Pb. The Pb adsorbed or taken up by the cells surviving for 24 h in the Pb solution was barely detectable, while the Pb adsorbed on pre-killed cells was clearly mappable. These findings suggest that living cells of P. bursaria have functions that reduce adsorption or uptake of Pb on the cells. Quantitative and SEC-UV-ICP-MS analyses of the Sr and Pb in aqueous phases showed no clear evidences that living cells of P. bursaria alter the chemical form of Sr or Pb remaining in the aqueous phases after the cell-solution contact.

  2. Behavior of Paramecium sp. in solutions containing Sr and Pb: Do Paramecium sp. alter chemical forms of those metals?

    Science.gov (United States)

    Kozai, Naofumi; Ohnuki, Toshihiko; Koka, Masahi; Satoh, Takahiro; Kamiya, Tomihiro

    2011-10-01

    The behavior of Paramecium sp. (Paramecium bursaria) in aqueous solutions containing Sr and Pb was investigated to determine the role of protozoa in the migration of radionuclides in the environment. Precultured living cells of P. bursaria were exposed to aqueous solutions containing 0.01 or 0.05 mM Sr or Pb at pH 7 for 24 h. For comparison, pre-killed cells were treated with the metal solutions in the same way. Two-dimensional elemental mappings of cells were obtained by micro-PIXE. Aquatic species of Sr and Pb were analyzed by size exclusion chromatography (SEC) coupled online to ultraviolet (UV) spectroscopy and inductivity coupled plasma mass spectroscopy (ICP-MS). The amounts of Sr adsorbed or taken up by the cells surviving for 24 h and adsorbed on pre-killed cells were below the detection limit. Cells of P. bursaria adsorbed or took up a fraction of Pb. The Pb adsorbed or taken up by the cells surviving for 24 h in the Pb solution was barely detectable, while the Pb adsorbed on pre-killed cells was clearly mappable. These findings suggest that living cells of P. bursaria have functions that reduce adsorption or uptake of Pb on the cells. Quantitative and SEC-UV-ICP-MS analyses of the Sr and Pb in aqueous phases showed no clear evidences that living cells of P. bursaria alter the chemical form of Sr or Pb remaining in the aqueous phases after the cell-solution contact.

  3. Behavior of Paramecium sp. in solutions containing Sr and Pb: Do Paramecium sp. alter chemical forms of those metals?

    Energy Technology Data Exchange (ETDEWEB)

    Kozai, Naofumi, E-mail: kozai.naofumi@jaea.go.jp [Advanced Sciences Research Center, Japan Atomic Energy Agency (JAEA), Tokai, Ibaraki 319-1195 (Japan); Ohnuki, Toshihiko [Advanced Sciences Research Center, Japan Atomic Energy Agency (JAEA), Tokai, Ibaraki 319-1195 (Japan); Koka, Masahi; Satoh, Takahiro; Kamiya, Tomihiro [Takasaki Advanced Radiation Research Institute, JAEA, 1233 Watanuki-machi, Takasaki, Gunma 370-1292 (Japan)

    2011-10-15

    The behavior of Paramecium sp. (Paramecium bursaria) in aqueous solutions containing Sr and Pb was investigated to determine the role of protozoa in the migration of radionuclides in the environment. Precultured living cells of P. bursaria were exposed to aqueous solutions containing 0.01 or 0.05 mM Sr or Pb at pH 7 for 24 h. For comparison, pre-killed cells were treated with the metal solutions in the same way. Two-dimensional elemental mappings of cells were obtained by micro-PIXE. Aquatic species of Sr and Pb were analyzed by size exclusion chromatography (SEC) coupled online to ultraviolet (UV) spectroscopy and inductivity coupled plasma mass spectroscopy (ICP-MS). The amounts of Sr adsorbed or taken up by the cells surviving for 24 h and adsorbed on pre-killed cells were below the detection limit. Cells of P. bursaria adsorbed or took up a fraction of Pb. The Pb adsorbed or taken up by the cells surviving for 24 h in the Pb solution was barely detectable, while the Pb adsorbed on pre-killed cells was clearly mappable. These findings suggest that living cells of P. bursaria have functions that reduce adsorption or uptake of Pb on the cells. Quantitative and SEC-UV-ICP-MS analyses of the Sr and Pb in aqueous phases showed no clear evidences that living cells of P. bursaria alter the chemical form of Sr or Pb remaining in the aqueous phases after the cell-solution contact.

  4. Chemical analysis of multicomponent aqueous solutions using a system of nonselective sensor and artificial neural networks

    International Nuclear Information System (INIS)

    Vlasov, Yu.G.; Legin, A.V.; Rudnitskaya, A.M.; Amiko, A.D.; Natale, K.D.

    1997-01-01

    With the aim of creating a multisensor system for determining heavy-metal cations (Cu 2+ , Pb 2+ , Cd 2+ , and Zn 2+ ) and inorganic anions (Cl - , F - , and SO 4 2- ), measurements in mixed solutions were carried out with the use of an array of sensors based on chalcogenide glass electrodes, and the possibility of using various methods of mathematical processing of the resulting intricate signals was studied. Three methods of data processing were used: multilinear regression, partial least squares, and artificial neural networks. It was found that the multisensor system proposed were suitable for determining all of the analytes with an accuracy of 1-10%. Because the responses of sensors in solutions of complex composition deviated from linearity, the lowest determination errors were obtained with the use of an artificial neural network. As to the method of data securing (nonselective response of a sensor array) and processing (artificial neural network), the multisensor system developed may be considered a prototype of a device of the electronic tongue type

  5. Effect of temperature on chlorproguanil and proguanil hydrochloride solutions: a chemical stability study.

    Science.gov (United States)

    Kolawole, J A; Mustapha, A; Abdul-Aguye, I; Ochekpe, N

    1996-04-01

    Chlorproguanil and proguanil hydrochloride solutions in 0.5 M hydrochloric acid, water and 1 M ammonium hydroxide were subjected to different temperatures (22-80 degrees C) for 68 h. The decomposition rate constants for chlorproguanil ranged from 1.60 to 47.6 x 10(3) h-1 in acid, 3.5 to 18 x 10(3) h-1 in water and 3.87 to 32.5 x 10(3) h-1 in base, between 50 degrees C and 80 degrees C. The activation energy Ea was 96.5, 52.12 and 62.1 kJ mol-1 in acid, water and base respectively. The proguanil decomposition rate constant ranged from 1.72 to 18.5 x 10(3) h-1 in acid, 1.58 to 9.67 x 10(3) h-1 in water and 2.34 to 15.77 x 10(3) h-1 in base, between 50 degrees C and 80 degrees C, with Ea values of 54.7, 73.3 and 62.5 kJ mol-1. Three unidentified degradation products were separated in the acid solution for each of the compounds. Chlorproguanil and proguanil are stable (t1/2 values over 30 days and up to 287 days respectively) in acid, water and base at temperatures below 22 degrees C.

  6. Intratesticular hypertonic sodium chloride solution treatment as a method of chemical castration in cattle.

    Science.gov (United States)

    Neto, Olmiro Andrade; Gasperin, Bernardo G; Rovani, Monique T; Ilha, Gustavo F; Nóbrega, Janduí E; Mondadori, Rafael G; Gonçalves, Paulo B D; Antoniazzi, Alfredo Q

    2014-10-15

    Castration of male calves is necessary for trading to facilitate handling and prevent reproduction. However, some methods of castration are traumatic and lead to economic losses because of infection and myiasis. The objective of the present study was to evaluate the efficiency of intratesticular injection (ITI) of hypertonic sodium chloride (NaCl; 20%) solution in male calf castration during the first weeks of life. Forty male calves were allocated to one of the following experimental groups: negative control-surgically castrated immediately after birth; positive control -intact males; G1-ITI from 1- to 5-day old; G2-ITI from 15- to 20-day old; and G3-ITI from 25- to 30-day old. Intratesticular injection induced coagulative necrosis of Leydig cells and seminiferous tubules leading to extensive fibrosis. Testosterone secretion and testicular development were severely impaired in 12-month-old animals from G1 and G2 groups (P<0.05), in which no testicular structure and sperm cells were observed during breeding soundness evaluation. Rectal and scrotal temperatures were not affected by different procedures. In conclusion, ITI of hypertonic NaCl solution induces sterility and completely suppresses testosterone secretion when performed during the first 20 days of life. Copyright © 2014 Elsevier Inc. All rights reserved.

  7. Muon capture in metallic, chemical and solution systems - recent results and future plans at Los Alamos

    International Nuclear Information System (INIS)

    Naumann, R.A.; Schmidt, G.; Knight, J.D.; Mausner, L.F.; Orth, C.J.; Schillaci, M.E.

    1977-01-01

    The recent results on capture ratios and the KX-ray intensity patterns in negative muon capture experiments carried out at Los Alamos are outlined. A set of experiments was devoted to capture process in alkali halide compounds. The capture ratio for alkali chlorides and for potassium halides was found to reveal the fall-out with increasing atomic number. The measurements carried out on aqueous ions of NaCl verifies the indication that the muonic KX-ray intensity patterns show enhanced intensity of the higher K numbers in comparison to that in crystalline NaCl. The systematic investigations of the variations of the K mesic X-ray intensity pattern was carried out for pure elements with atomic number ranging from 6 to 34. The dependence of the X-ray intensity pattern on atomic number exhibits a maximum in the vicinity of Z=25 (manganese). Another research program is concerned with quantitative tests of the dependence of the muon capture on composition for solid solutions. Measurements are underway using two binary metallic alloy systems of aluminium-copper, silver-zinc and three continuous solid solutions formed by sodium chloride-sodium bromide, potassium chloride-potassium bromide and potassium bromide-potassium iodide

  8. STUDY OF CHEMICAL INTERACTION OF MAGNESIA CEMENT WITH HIGH CONCENTRATION MAGNESIUM CHLORIDE SOLUTIONS

    Directory of Open Access Journals (Sweden)

    DEREVIANKO V. N.

    2015-10-01

    Full Text Available Problem statement. In activating MgO by electrolyte salts, as a result of formation of non water-resist magnesium silicate hydrate are obtained the durable cement stone having the low water-resist. I. P. Vyrodov considers [9; 5], that magnesia cement curing in mixing with sufficiently concentrated (C > 20 % solutions MgCl2 is caused with the crystallization of oxyhydrochloride composition: 3MgO∙MgCl2∙11Н2О, 5MgO∙MgCl2∙13Н2О and 7MgO∙MgCl2∙15Н2О. In the lower concentration parts of MgCl2 solution is formed a transitional compound of Mg[(OHnCl2-n] with isomorphous Mg(OH2 structure. At very low Cl concentration only Mg(OH2 is practically formed. Purpose. The Formation of water-resist magnesium silicate hydrates for obtaining of fast curing and solid structure of the magnesia stone. Conclusion. The dependence of the formation of the magnesia stone from the ratio (MgO/MgCl2 of the magnesia cement (MgO and the magnesium chloride solution (MgCl2 of different density has been identified in order to obtain the best content for oxyhydrochloride 3MgO•MgCl2•11Н2О, 5MgO•MgCl2•13Н2О and magnesium hydroxide (Mg(OH2. In putting into the system MgO∙–∙H2О of the silicic acid or fine ground quartz grains with size of less than 20 – 30 microns, over 1 month for the magnesium silicate hydrates formation is needed, where from 2 to 5 % of the total number of newgrowths are created. The study is proved by the expert opinion, that magnesium silicate hydrates do not have binding properties, unlike calcium silicate hydrates, and the main role in the system curing is played with the Mg(OH2 gel recrystallization, which provides the acceptable stone strength (R ≈ 30MPa in a few years. It has been also established, that in mixing of cement with low concentration MgO solutions of less than 1,5 mol/l (or 13% 1,1g/sm3, the final product in the stone structure is Mg(OH2. With increasing the sealer (MgCl2 solution there is formed by turn in

  9. As (V) biosorption in an aqueous solution using chemically treated lemon (Citrus aurantifolia Swingle) residues.

    Science.gov (United States)

    Marín-Rangel, Vania Marilyn; Cortés-Martínez, Raúl; Villanueva, Ruth Alfaro Cuevas; Garnica-Romo, Ma Guadalupe; Martínez-Flores, Héctor Eduardo

    2012-01-01

    The use of biosorbents to remove metals and metalloids from contaminated water systems has gained great usage in various parts of the world. The objective of the current study was to test lemon peels as biosorbents for As (V). Lemon peels were chemically characterized and arsenic contact experiments were performed to determine the adsorption capacity of the peels using different empirical models. The model that fit the experimental data was the Lagergren empirical model with a correlation coefficient of R= 0.8841. The results show that lemon peels were able to retain 474.8 μg of As (V)/g of biosorbent. Lemon agro-industrial waste can be useful in the removal of heavy metals, such as arsenic, from aqueous media. © 2011 Institute of Food Technologists®

  10. Pectin gelation with chlorhexidine: Physico-chemical studies in dilute solutions.

    Science.gov (United States)

    Lascol, Manon; Bourgeois, Sandrine; Guillière, Florence; Hangouët, Marie; Raffin, Guy; Marote, Pedro; Lantéri, Pierre; Bordes, Claire

    2016-10-05

    Low methoxyl pectin is known to gel with divalent cations (e.g. Ca(2+), Zn(2+)). In this study, a new way of pectin gelation in the presence of an active pharmaceutical ingredient, chlorhexidine (CX), was highlighted. Thus chlorhexidine interactions with pectin were investigated and compared with the well-known pectin/Ca(2+) binding model. Gelation mechanisms were studied by several physico-chemical methods such as zeta potential, viscosity, size measurements and binding isotherm was determined by Proton Nuclear Magnetic Resonance Spectroscopy ((1)H NMR). The binding process exhibited similar first two steps for both divalent ions: a stoichiometric monocomplexation of the polymer followed by a dimerization step. However, stronger interactions were observed between pectin and chlorhexidine. Moreover, the dimerization step occurred under stoichiometric conditions with chlorhexidine whereas non-stoichiometric conditions were involved with calcium ions. In the case of chlorhexidine, an additional intermolecular binding occurred in a third step. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Problems and solutions in the estimation of genetic risks from radiation and chemicals

    International Nuclear Information System (INIS)

    Russell, W.L.

    1980-01-01

    Extensive investigations with mice on the effects of various physical and biological factors, such as dose rate, sex and cell stage, on radiation-induced mutation have provided an evaluation of the genetics hazards of radiation in man. The mutational results obtained in both sexes with progressive lowering of the radiation dose rate have permitted estimation of the mutation frequency expected under the low-level radiation conditions of most human exposure. Supplementing the studies on mutation frequency are investigations on the phenotypic effects of mutations in mice, particularly anatomical disorders of the skeleton, which allow an estimation of the degree of human handicap associated with the occurrence of parallel defects in man. Estimation of the genetic risk from chemical mutagens is much more difficult, and the research is much less advanced. Results on transmitted mutations in mice indicate a poor correlation with mutation induction in non-mammalian organisms

  12. Chemical, mass spectrometric, spectrochemical, nuclear, and radiochemical analysis of nuclear-grade plutonium nitrate solutions

    International Nuclear Information System (INIS)

    Anon.

    1981-01-01

    These analytical procedures are designed to show whether a given material meets the purchaser's specifications as to plutonium content, effective fissile content, and impurity content. The following procedures are described in detail: plutonium by controlled-potential coulometry; plutonium by amperometric titration with iron(II); free acid by titration in an oxalate solution; free acid by iodate precipitation-potentiometric titration method; uranium by Arsenazo I spectrophotometric method; thorium by thorin spectrophotometric method; iron by 1,10-phenanthroline spectrophotometric method; chloride by thiocyanate spectrophotometric method; fluoride by distillation-spectrophotometric method; sulfate by barium sulfate turbidimetric method; isotopic composition by mass spectrometry; americium-241 by extraction and gamma counting; americium-241 by gamma counting; gamma-emitting fission products, uranium, and thorium by gamma-ray spectroscopy; rare earths by copper spark spectrochemical method; tungsten, niobium (columbium), and tantalum by spectrochemical method; simple preparation by spectrographic analysis for general impurities

  13. A comparison of three-dimensional nonequilibrium solution algorithms applied to hypersonic flows with stiff chemical source terms

    Science.gov (United States)

    Palmer, Grant; Venkatapathy, Ethiraj

    1993-01-01

    Three solution algorithms, explicit underrelaxation, point implicit, and lower upper symmetric Gauss-Seidel (LUSGS), are used to compute nonequilibrium flow around the Apollo 4 return capsule at 62 km altitude. By varying the Mach number, the efficiency and robustness of the solution algorithms were tested for different levels of chemical stiffness. The performance of the solution algorithms degraded as the Mach number and stiffness of the flow increased. At Mach 15, 23, and 30, the LUSGS method produces an eight order of magnitude drop in the L2 norm of the energy residual in 1/3 to 1/2 the Cray C-90 computer time as compared to the point implicit and explicit under-relaxation methods. The explicit under-relaxation algorithm experienced convergence difficulties at Mach 23 and above. At Mach 40 the performance of the LUSGS algorithm deteriorates to the point it is out-performed by the point implicit method. The effects of the viscous terms are investigated. Grid dependency questions are explored.

  14. Electro chemical studies on stress corrosion cracking of Incoloy-800 in caustic solution, part I: As received samples

    Directory of Open Access Journals (Sweden)

    Dinu Alice

    2005-01-01

    Full Text Available Many non-volatile impurities accidentally introduced into the steam generator tend to Concentrate on its surface in restricted flow areas. In this way these impurities can lead to stress corrosion cracking (SCC on stressed tubes of the steam generator. Such impurities can be strong alkaline or acid solutions. To evaluate the effect of alkaline concentrated environments on SCC of steam generator tubes, the tests were con ducted on stressed samples of Incoloy-800 in 10% NaOH solution. To accelerate the SCC process, stressed specimens were anodically polarised in a caustic solution in an electro chemical cell. The method of stressing of Incoloy-800 tubes used in our experiments was the C-ring. Using the cathodic zone of the potentiodynamic curves it was possible to calculate the most important electrochemical parameters: the corrosion current, the corrosion rate, and the polarization resistance. We found that the value of the corrosion potential to initiate the SCC microcracks was -100 mV. The tested samples were examined using the metallographic method. The main experimental results showed that the in crease of the stress state promoted the in crease of the SCC susceptibility of Incoloy-800 samples tested under the same conditions, and that the length of the SCC-type microcracks in creased with the growth of the stress value.

  15. Chemical studies on the distribution of some heavy metals between two immiscible solutions

    International Nuclear Information System (INIS)

    Rizk, S.E.M.

    2011-01-01

    Separation and recovery of divalent zinc and cobalt ions from mixed sulphate and thiocyanate solutions have been carried out using CYANEX 921 (trioctylphosphine oxide), CYANEX 923 (a mixture of straight chain alkylated phosphine oxides) and CYANEX 925 (a mixture of branched chain alkylated phosphine oxides) in kerosene. Different parameters affecting the extraction equilibrium of Zn(II) and Co(II) in addition to temperature, were studied and the stoichiometry of the extracted Zn(II) and Co(II) species were postulated based on slope analysis method. The respective loaded organic phases were stripped with different mineral acids. The extraction percent of metal ions was found to increase with increasing ph and zinc was preferentially extracted over cobalt in the different investigated systems. The highest separation factor was obtained when using 0.015 M CYANEX 925 as extractant. Based on the obtained results, application of the method was tested to separate Zn(II) and Co(II) from Nickel Metal Hydride batteries (Ni-MH batteries) leached by 2.0 M H 2 SO 4 and good results were obtained. The extraction of Zn(II) and Co(II) from aqueous mixed sulphate and thiocyanate medium through supported liquid membrane (SLM) using CYANEX 925 in kerosene as carrier supported on cellulose nitrate membrane was studied. The influence of different parameters on the permeation of the investigated metals such as ph, extractant concentration, sulphuric acid concentration, thiocyanate concentration and strip solution concentration were also studied. The selectivity of the used system for Zn / Co separation is evaluated.

  16. Variations in the chemical composition of the solution extracted from a Latosol under fertigation with vinasse

    Directory of Open Access Journals (Sweden)

    João Paulo Francisco

    2016-06-01

    Full Text Available ABSTRACT The aim of this work was to evaluate the change in electrical conductivity and pH of a soil solution and its composition, with regard to the levels of nitrate and potassium, in a Latosol cultivated with pineapple and subjected to applications of different levels of vinasse. The experiment was conducted in a greenhouse at the Department of Biosystems Engineering of ESALQ/USP. The treatments comprised the application of five levels of vinasse: T1 - 0 m3 ha-1, T2 - 231 m3 ha-1, T3 - 347 m3 ha-1, T4 - 462 m3 ha-1, and T5 - 578 m3 ha-1. Application was every 20 days, using a localised irrigation system with emitters having a nominal flow rate of 4 L h-1 and spaced 0.40 m apart. The applied doses of vinasse were calculated by following the recommendations of CETESB standard P4.231, so that treatment T4 would supply the demand of the pineapple plant for potassium. The solution was collected by means of porous capsule extractors at 30, 120 and 210 days from the start of vinasse application. It was found that increases in the volume of the applied levels resulted in greater values for the electrical conductivity of the soil (ECs and in the concentration of potassium (K and nitrate (NO3, with higher values being obtained in the 0.20 m layer. The results demonstrated that pH decreased with increases in the vinasse being applied.

  17. Improvement of malaria diagnostic system based on acridine orange staining.

    Science.gov (United States)

    Kimura, Masatsugu; Teramoto, Isao; Chan, Chim W; Idris, Zulkarnain Md; Kongere, James; Kagaya, Wataru; Kawamoto, Fumihiko; Asada, Ryoko; Isozumi, Rie; Kaneko, Akira

    2018-02-07

    Rapid diagnosis of malaria using acridine orange (AO) staining and a light microscope with a halogen lamp and interference filter was deployed in some malaria-endemic countries. However, it has not been widely adopted because: (1) the lamp was weak as an excitation light and the set-up did not work well under unstable power supply; and, (2) the staining of samples was frequently inconsistent. The halogen lamp was replaced by a low-cost, blue light-emitting diode (LED) lamp. Using a reformulated AO solution, the staining protocol was revised to make use of a concentration gradient instead of uniform staining. To evaluate this new AO diagnostic system, a pilot field study was conducted in the Lake Victoria basin in Kenya. Without staining failure, malaria infection status of about 100 samples was determined on-site per one microscopist per day, using the improved AO diagnostic system. The improved AO diagnosis had both higher overall sensitivity (46.1 vs 38.9%: p = 0.08) and specificity (99.0 vs 96.3%) than the Giemsa method (N = 1018), using PCR diagnosis as the standard. Consistent AO staining of thin blood films and rapid evaluation of malaria parasitaemia with the revised protocol produced superior results relative to the Giemsa method. This AO diagnostic system can be set up easily at low cost using an ordinary light microscope. It may supplement rapid diagnostic tests currently used in clinical settings in malaria-endemic countries, and may be considered as an inexpensive tool for case surveillance in malaria-eliminating countries.

  18. Prophylactic Cefazolin in Amnioinfusions Administered for Meconium-Stained Amniotic Fluid

    Directory of Open Access Journals (Sweden)

    R. K. Edwards

    1999-01-01

    Full Text Available Objective: To determine if amnioinfusion with an antibiotic solution decreased the rate of clinical chorioamnionitis and puerperal endometritis in patients with meconium-stained amniotic fluid.

  19. Laser treatment of Port-wine stains

    OpenAIRE

    Boffa, Michael J.

    2001-01-01

    A state-of-the-art pulsed dye laser machine to treat port-wine stains and other vascular lesions has been available in the Malta Health Service since 1999. This article reviews the pathophysiology and clinical features of port- wine stains and describes the principles of laser treatment for this condition.

  20. CHEMICALS

    CERN Multimedia

    Medical Service

    2002-01-01

    It is reminded that all persons who use chemicals must inform CERN's Chemistry Service (TIS-GS-GC) and the CERN Medical Service (TIS-ME). Information concerning their toxicity or other hazards as well as the necessary individual and collective protection measures will be provided by these two services. Users must be in possession of a material safety data sheet (MSDS) for each chemical used. These can be obtained by one of several means : the manufacturer of the chemical (legally obliged to supply an MSDS for each chemical delivered) ; CERN's Chemistry Service of the General Safety Group of TIS ; for chemicals and gases available in the CERN Stores the MSDS has been made available via EDH either in pdf format or else via a link to the supplier's web site. Training courses in chemical safety are available for registration via HR-TD. CERN Medical Service : TIS-ME :73186 or service.medical@cern.ch Chemistry Service : TIS-GS-GC : 78546

  1. Chemical, mass spectrometric, spectrochemical, nuclear, and radiochemical analysis of nuclear-grade uranyl nitrate solutions

    International Nuclear Information System (INIS)

    Anon.

    1981-01-01

    The standard covers analytical procedures to determine compliance of nuclear-grade uranyl nitrate solution to specifications. The following methods are described in detail: uranium by ferrous sulfate reduction-potassium dichromate titrimetry and by ignition gravimetry; specific gravity by pycnometry; free acid by oxalate complexation; thorium by the Arsenazo(III) (photometric) method; chromium by the diphenylcarbazide (photometric) method; molybdenum by the thiocyanate (photometric) method; halogens separation by steam distillation; fluorine by specific ion electrode; halogen distillate analysis: chloride, bromide and iodide by amperometric microtitrimetry; bromine by the fluorescein (photometric) method; sulfate sulfur by (photometric) turbidimetry; phosphorus by the molybdenum blue (photometric) method; silicon by the molybdenum blue (photometric) method; carbon by persulfate oxidation-acid titrimetry; nonvolatile impurities by spectrography; volatile impurities by rotating-disk spark spectrography; boron by emission spectrography; impurity elements by spark source mass spectrography; isotopic composition by multiple filament surface-ionization mass spectrometry; uranium-232 by alpha spectrometry; total alpha activity by direct alpha counting; fission product activity by beta and gamma counting; entrained organic matter by infrared spectrophotometry

  2. Dynamic chemical characteristics of soil solution after pig manure application: a column study.

    Science.gov (United States)

    Hao, Xiuzhen; Zhou, Dongmei; Sun, Lei; Li, Lianzhen; Zhang, Hailin

    2008-06-01

    When manures from intensive livestock operations are applied to agricultural or vegetable fields at a high rate, large amounts of salts and metals will be introduced into soils. Using a column leaching experiment, this study assessed the leaching potential of the downward movement of Cu and Zn as well as some salt ions after an intensive farm pig manure at rates of 0%, 5% and 10% (w/w) were applied to the top 20 cm of two different textured soils (G soil -sandy loam soil; H soil-silty clay loam soil), and investigated the growth of amaranth and Cu and Zn transfer from soil to amaranth (Amaranthus tricolor). Soil solutions were obtained at 20, 40 and 60 cm depth of the packed column and analyzed for pH, electrical conductivity (EC), dissolved organic matter (DOC) and Cu and Zn concentrations. The results indicated that application of pig manure containing Cu and Zn to sandy loam soil might cause higher leaching and uptake risk than silty clay loam soil, especially at high application rates. And manure amendment at 5% and 10% significantly decreased the biomass of amaranth, in which the salt impact rather than Cu and Zn toxicity from manures played more important role in amaranth growth. Thus the farmer should avoid application the high rate of pig manure containing metal and salt to soil at a time, especially in sandy soil.

  3. Optimisation of chemical solution deposition of indium tin oxide thin films

    Energy Technology Data Exchange (ETDEWEB)

    Sunde, Tor Olav Løveng; Einarsrud, Mari-Ann; Grande, Tor, E-mail: grande@ntnu.no

    2014-12-31

    An environmentally friendly aqueous sol–gel process has been optimised to deposit indium tin oxide (ITO) thin films, aiming to improve the film properties and reduce the deposition costs. It was demonstrated how parameters such as cation concentration and viscosity could be applied to modify the physical properties of the sol and thereby reduce the need for multiple coatings to yield films with sufficient conductivity. The conductivity of the thin films was enhanced by adjusting the heat treatment temperature and atmosphere. Both increasing the heat treatment temperature of the films from 530 to 800 °C and annealing in reducing atmosphere significantly improved the electrical conductivity, and conductivities close to the state of the art sputtered ITO films were obtained. A pronounced decreased conductivity was observed after exposing the thin films to air and the thermal reduction and ageing of the film was studied by in situ conductivity measurements. - Highlights: • Spin coating of indium tin oxide using an aqueous solution was optimised. • The conductivity was enhanced by thermal annealing in reducing atmosphere. • The conductivity of is comparable to the conductivity of sputtered films. • A relaxation process in the reduced thin film was observed after exposure in air.

  4. Computational modeling of chemical reactions and interstitial growth and remodeling involving charged solutes and solid-bound molecules.

    Science.gov (United States)

    Ateshian, Gerard A; Nims, Robert J; Maas, Steve; Weiss, Jeffrey A

    2014-10-01

    Mechanobiological processes are rooted in mechanics and chemistry, and such processes may be modeled in a framework that couples their governing equations starting from fundamental principles. In many biological applications, the reactants and products of chemical reactions may be electrically charged, and these charge effects may produce driving forces and constraints that significantly influence outcomes. In this study, a novel formulation and computational implementation are presented for modeling chemical reactions in biological tissues that involve charged solutes and solid-bound molecules within a deformable porous hydrated solid matrix, coupling mechanics with chemistry while accounting for electric charges. The deposition or removal of solid-bound molecules contributes to the growth and remodeling of the solid matrix; in particular, volumetric growth may be driven by Donnan osmotic swelling, resulting from charged molecular species fixed to the solid matrix. This formulation incorporates the state of strain as a state variable in the production rate of chemical reactions, explicitly tying chemistry with mechanics for the purpose of modeling mechanobiology. To achieve these objectives, this treatment identifies the specific theoretical and computational challenges faced in modeling complex systems of interacting neutral and charged constituents while accommodating any number of simultaneous reactions where reactants and products may be modeled explicitly or implicitly. Several finite element verification problems are shown to agree with closed-form analytical solutions. An illustrative tissue engineering analysis demonstrates tissue growth and swelling resulting from the deposition of chondroitin sulfate, a charged solid-bound molecular species. This implementation is released in the open-source program FEBio ( www.febio.org ). The availability of this framework may be particularly beneficial to optimizing tissue engineering culture systems by examining the

  5. Integrating chemical imaging of cationic trace metal solutes and pH into a single hydrogel layer

    International Nuclear Information System (INIS)

    Hoefer, Christoph; Santner, Jakob; Borisov, Sergey M.; Wenzel, Walter W.; Puschenreiter, Markus

    2017-01-01

    Gel-based, two-dimensional (2D) chemical imaging techniques are versatile methods for investigating biogeochemically active environments at high spatial resolution (sub-mm). State-of-the-art solute imaging techniques, such as diffusive gradients in thin films (DGT) and planar optodes (PO), employ passive solute sampling or sensing. Combining these methods will provide powerful tools for studying the biogeochemistry of biological niches in soils and sediments. In this study we aimed at developing a combined single-layer gel for direct pH imaging using PO and sampling of anionic and cationic solutes by DGT, with subsequent analysis of the bound solutes by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). We tested three ultra-thin (<100 μm) polyurethane-based gels, incorporating anion and cation binding materials and the fluorescent pH indicator DCIFODA (2′,7′-dichloro-5(6)-N-octadecyl-carboxamidofluorescein). Results showed that PO-based pH sensing using DCIFODA was impossible in the presence of the anion binding materials due to interferences with DCIFODA protonation. One gel, containing only a cation binding material and DCIFODA, was fully characterized and showed similar performance characteristics as comparable DGT-only gels (applicable pH range: pH 5–8, applicable ionic strength range: 1–20 mmol L"-"1, cation binding capacity ∼24 μg cm"−"2). The dynamic range for PO-based pH mapping was between pH 5.5 and 7.5 with t_9_0 response time of ∼60 min. In a case study we demonstrated the gel's suitability for multi-analyte solute imaging and mapped pH gradients and concurrent metal solubility patterns in the rhizosphere of Salix smithiana. pH decreases in the rooted soil were co-localized with elevated solute fluxes of Al"3"+, Co"2"+, Cu"2"+, Fe, Mn"2"+, Ni"2"+ and Pb"2"+, indicating pH-induced metal solubilisation. - Highlights: • Diffusive gradients in thin films (DGT) and planar optode (PO) imaging is combined. • A

  6. Integrating chemical imaging of cationic trace metal solutes and pH into a single hydrogel layer

    Energy Technology Data Exchange (ETDEWEB)

    Hoefer, Christoph [Department of Forest and Soil Sciences, Institute of Soil Research, University of Natural Resources and Life Sciences, Vienna, Konrad-Lorenz-Strasse 24, A-3430 Tulln (Austria); Santner, Jakob, E-mail: jakob.santner@boku.ac.at [Department of Forest and Soil Sciences, Institute of Soil Research, University of Natural Resources and Life Sciences, Vienna, Konrad-Lorenz-Strasse 24, A-3430 Tulln (Austria); Department of Crop Sciences, Division of Agronomy, University of Natural Resources and Life Sciences, Vienna, Konrad-Lorenz-Strasse 24, 3430 Tulln (Austria); Borisov, Sergey M. [Institute of Analytical Chemistry and Food Chemistry, Graz University of Technology, Stremayrgasse 9, A-8010, Graz (Austria); Wenzel, Walter W.; Puschenreiter, Markus [Department of Forest and Soil Sciences, Institute of Soil Research, University of Natural Resources and Life Sciences, Vienna, Konrad-Lorenz-Strasse 24, A-3430 Tulln (Austria)

    2017-01-15

    Gel-based, two-dimensional (2D) chemical imaging techniques are versatile methods for investigating biogeochemically active environments at high spatial resolution (sub-mm). State-of-the-art solute imaging techniques, such as diffusive gradients in thin films (DGT) and planar optodes (PO), employ passive solute sampling or sensing. Combining these methods will provide powerful tools for studying the biogeochemistry of biological niches in soils and sediments. In this study we aimed at developing a combined single-layer gel for direct pH imaging using PO and sampling of anionic and cationic solutes by DGT, with subsequent analysis of the bound solutes by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). We tested three ultra-thin (<100 μm) polyurethane-based gels, incorporating anion and cation binding materials and the fluorescent pH indicator DCIFODA (2′,7′-dichloro-5(6)-N-octadecyl-carboxamidofluorescein). Results showed that PO-based pH sensing using DCIFODA was impossible in the presence of the anion binding materials due to interferences with DCIFODA protonation. One gel, containing only a cation binding material and DCIFODA, was fully characterized and showed similar performance characteristics as comparable DGT-only gels (applicable pH range: pH 5–8, applicable ionic strength range: 1–20 mmol L{sup -1}, cation binding capacity ∼24 μg cm{sup −2}). The dynamic range for PO-based pH mapping was between pH 5.5 and 7.5 with t{sub 90} response time of ∼60 min. In a case study we demonstrated the gel's suitability for multi-analyte solute imaging and mapped pH gradients and concurrent metal solubility patterns in the rhizosphere of Salix smithiana. pH decreases in the rooted soil were co-localized with elevated solute fluxes of Al{sup 3+}, Co{sup 2+}, Cu{sup 2+}, Fe, Mn{sup 2+}, Ni{sup 2+} and Pb{sup 2+}, indicating pH-induced metal solubilisation. - Highlights: • Diffusive gradients in thin films (DGT) and planar

  7. Colour stabilities of three types of orthodontic clear aligners exposed to staining agents

    OpenAIRE

    Liu, Chen-Lu; Sun, Wen-Tian; Liao, Wen; Lu, Wen-Xin; Li, Qi-Wen; Jeong, Yunho; Liu, Jun; Zhao, Zhi-He

    2016-01-01

    The aim of this study was to evaluate and compare the colour stabilities of three types of orthodontic clear aligners exposed to staining agents in vitro. Sixty clear orthodontic aligners produced by three manufacturers (Invisalign, Angelalign, and Smartee) were immersed in three staining solutions (coffee, black tea, and red wine) and one control solution (distilled water). After 12-h and 7-day immersions, the aligners were washed in an ultrasonic cleaner and measured with a colourimeter. Th...

  8. Properties of NiO thin films deposited by chemical spray pyrolysis using different precursor solutions

    Energy Technology Data Exchange (ETDEWEB)

    Cattin, L. [Universite de Nantes, Nantes Atlantique Universites, LAMP, EA 3825, Faculte des Sciences et des Techniques, 2 rue de la Houssiniere, BP 92208, Nantes F-44000 (France); Reguig, B.A.; Khelil, A. [Universite d' Oran Es-Senia, LPCM2E (Algeria); Morsli, M. [Universite de Nantes, Nantes Atlantique Universites, LAMP, EA 3825, Faculte des Sciences et des Techniques, 2 rue de la Houssiniere, BP 92208, Nantes F-44000 (France); Benchouk, K. [Universite d' Oran Es-Senia, LPCM2E (Algeria); Bernede, J.C. [Universite de Nantes, Nantes Atlantique Universites, LAMP, EA 3825, Faculte des Sciences et des Techniques, 2 rue de la Houssiniere, BP 92208, Nantes F-44000 (France)], E-mail: Jean-Christian.Bernede@univ-nantes.fr

    2008-07-15

    NiO thin films have been deposited by chemical spray pyrolysis using a perfume atomizer to grow the aerosol. The influence of the precursor, nickel chloride hexahydrate (NiCl{sub 2}.6H{sub 2}O), nickel nitrate hexahydrate (Ni(NO{sub 3}){sub 2}.6H{sub 2}O), nickel hydroxide hexahydrate (Ni(OH){sub 2}.6H{sub 2}O), nickel sulfate tetrahydrate (NiSO{sub 4}.4H{sub 2}O), on the thin films properties has been studied. In the experimental conditions used (substrate temperature 350 deg. C, precursor concentration 0.2-0.3 M, etc.), pure NiO thin films crystallized in the cubic phase can be achieved only with NiCl{sub 2} and Ni(NO{sub 3}){sub 2} precursors. These films have been post-annealed at 425 deg. C for 3 h either in room atmosphere or under vacuum. If all the films are p-type, it is shown that the NiO films conductivity and optical transmittance depend on annealing process. The properties of the NiO thin films annealed under room atmosphere are not significantly modified, which is attributed to the fact that the temperature and the environment of this annealing is not very different from the experimental conditions during spray deposition. The annealing under vacuum is more efficient. This annealing being proceeded in a vacuum no better than 10{sup -2} Pa, it is supposed that the modifications of the NiO thin film properties, mainly the conductivity and optical transmission, are related to some interaction between residual oxygen and the films.

  9. Adsorption of ibuprofen from aqueous solution on chemically surface-modified activated carbon cloths

    Directory of Open Access Journals (Sweden)

    Hanen Guedidi

    2017-05-01

    Full Text Available This study aims to investigate the performance of an activated carbon cloth for adsorption of ibuprofen. The cloth was oxidized by a NaOCl solution (0.13 mol L−1 or thermally treated under N2 (700 °C for 1 hour. The raw and modified cloths were characterized by N2 adsorption–desorption measurement at 77 K, CO2 adsorption at 273 K, Boehm titrations, pHPZC measurements, X-ray Photoelectron Spectroscopy analysis, and by infrared spectroscopy. The NaOCl treatment increases the acidic sites, mostly creating phenolic and carboxylic groups and decreases both the specific surface area and slightly the micropore volume. However, the thermal treatment at 700 °C under N2 induced a slight increase in the BET specific surface area and yielded to the only increase in the carbonyl group content. Ibuprofen adsorption studies of kinetics and isotherms were carried out at pH = 3 and 7. The adsorption properties were correlated to the cloth porous textures, surface chemistry and pH conditions. The isotherms of adsorption were better reproduced by Langmuir–Freundlich models at 298, 313 and 328 K. The adsorption of ibuprofen on the studied activated carbon cloths at pH 3 was an endothermic process. The pore size distributions of all studied ibuprofen-loaded fabrics were determined by DFT method to investigate the accessible porosity of the adsorbate. Both treatments do not influence the kind of micropores where the adsorption of ibuprofen occurred.

  10. Improvement in fatigue property for a PZT ferroelectric film device with SRO electrode film prepared by chemical solution deposition

    International Nuclear Information System (INIS)

    Miyazaki, H.; Miwa, Y.; Suzuki, H.

    2007-01-01

    PZT films with (1 0 0) and (1 1 0) orientation were prepared by spin coating using the chemical solution deposition (CSD) method on an SRO/Si or a Pt/Ti/SiO 2 /Si substrate. The remnant polarization and the saturation polarization of the PZT/SRO/Si film were 21 and 35 μC/cm 2 , and those of the PZT/Pt/Ti/SiO 2 /Si film were 20 and 31 μC/cm 2 . The remnant polarization of the PZT/SRO/Si film maintained more than 10 8 switching cycles, and the fatigue property was observed for the PZT film fabricated on the Pt/Ti/SiO 2 /Si electrode

  11. Standard test methods for chemical, mass spectrometric, spectrochemical, nuclear, and radiochemical analysis of nuclear-grade uranyl nitrate solutions

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    1999-01-01

    1.1 These test methods cover procedures for the chemical, mass spectrometric, spectrochemical, nuclear, and radiochemical analysis of nuclear-grade uranyl nitrate solution to determine compliance with specifications. 1.2 The analytical procedures appear in the following order: Sections Determination of Uranium 7 Specific Gravity by Pycnometry 15-20 Free Acid by Oxalate Complexation 21-27 Determination of Thorium 28 Determination of Chromium 29 Determination of Molybdenum 30 Halogens Separation by Steam Distillation 31-35 Fluoride by Specific Ion Electrode 36-42 Halogen Distillate Analysis: Chloride, Bromide, and Iodide by Amperometric Microtitrimetry 43 Determination of Chloride and Bromide 44 Determination of Sulfur by X-Ray Fluorescence 45 Sulfate Sulfur by (Photometric) Turbidimetry 46 Phosphorus by the Molybdenum Blue (Photometric) Method 54-61 Silicon by the Molybdenum Blue (Photometric) Method 62-69 Carbon by Persulfate Oxidation-Acid Titrimetry 70 Conversion to U3O8 71-74 Boron by ...

  12. Effective Remediation of Lead Ions from Aqueous Solution by Chemically Carbonized Rubber Wood Sawdust: Equilibrium, Kinetics, and Thermodynamic Study

    Directory of Open Access Journals (Sweden)

    Swarup Biswas

    2015-01-01

    Full Text Available Rubber wood sawdust was carbonized into charcoal by chemical treatment which was used for removal of lead ion from aqueous solution. The work involves batch experiments to investigate the pH effect, initial concentration of adsorbate, contact time, and adsorbent dose. Experimental data confirmed that the adsorption capacities increased with increasing inlet concentration and bed height and decreased with increasing flow rate. Adsorption results showed a maximum adsorption capacity of 37 mg/g at 308 K. Langmuir, Freundlich, and Temkin model adsorption isotherm models were applied to analyze the process where Temkin was found as a best fitted model for present study. Simultaneously kinetics of adsorption like pseudo-first-order, pseudo-second-order, and intraparticle diffusion models were investigated. Thermodynamic parameters were used to analyze the adsorption experiment. Fourier transform infrared spectroscopy, scanning electron microscope, and energy dispersive X-ray spectroscopy confirmed the batch adsorption of lead ion onto chemically carbonized rubber wood sawdust.

  13. Chemical Stability of Cd(II and Cu(II Ionic Imprinted Amino-Silica Hybrid Material in Solution Media

    Directory of Open Access Journals (Sweden)

    Buhani, Narsito, Nuryono, Eko Sri Kunarti

    2015-12-01

    Full Text Available Chemical stability of Cd(II and Cu(II ionic imprinted hybrid material of (i-Cd-HAS and i-Cu-HAS derived from silica modification with active compound (3-aminopropyl-trimethoxysilane (3-APTMS has been studied in solution media. Stability test was performed with HNO3 0.1 M (pH 1.35 to investigate material stability at low pH condition, CH3COONa 0.1 M (pH 5.22 for adsorption process optimum pH condition, and in the water (pH 9.34 for base condition. Material characteristics were carried out with infrared spectrophotometer (IR and atomic absorption spectrophotometer (AAS. At interaction time of 4 days in acid and neutral condition, i-Cd-HAS is more stable than i-Cu-HAS with % Si left in material 95.89 % (acid media, 43.82 % (close to neutral, and 9.39 % (base media.Keywords: chemical stability, amino-silica hybrid, ionic imprinting technique

  14. Lie Group Solution for Free Convective Flow of a Nanofluid Past a Chemically Reacting Horizontal Plate in a Porous Media

    Directory of Open Access Journals (Sweden)

    M. M. Rashidi

    2014-01-01

    Full Text Available The optimal homotopy analysis method (OHAM is employed to investigate the steady laminar incompressible free convective flow of a nanofluid past a chemically reacting upward facing horizontal plate in a porous medium taking into account heat generation/absorption and the thermal slip boundary condition. Using similarity transformations developed by Lie group analysis, the continuity, momentum, energy, and nanoparticle volume fraction equations are transformed into a set of coupled similarity equations. The OHAM solutions are obtained and verified by numerical results using a Runge-Kutta-Fehlberg fourth-fifth order method. The effect of the emerging flow controlling parameters on the dimensionless velocity, temperature, and nanoparticle volume fraction have been presented graphically and discussed. Good agreement is found between analytical and numerical results of the present paper with published results. This close agreement supports our analysis and the accuracy of the numerical computations. This paper also includes a representative set of numerical results for reduced Nusselt and Sherwood numbers in a table for various values of the parameters. It is concluded that the reduced Nusselt number increases with the Lewis number and reaction parameter whist it decreases with the order of the chemical reaction, thermal slip, and generation parameters.

  15. Chemical Stability of Cd(II and Cu(II Ionic Imprinted Amino-Silica Hybrid Material in Solution Media

    Directory of Open Access Journals (Sweden)

    Buhani Buhani

    2012-02-01

    Full Text Available Chemical stability of Cd(II and Cu(II ionic imprinted amino-silica (HAS material of (i-Cd-HAS and i-Cu-HAS derived from silica modification with active compound (3-aminopropyl-trimethoxysilane (3-APTMS has been studied in solution media.  Stability test was performed with HNO3 0.1 M (pH 1.35 to investigate material stability at low pH condition, acetat buffer at pH 5.22 for adsorption process optimum pH condition, and in the water (pH 9.34 for base condition.  Material characteristics were carried out with infrared spectrophotometer (IR and atomic absorption spectrophotometer (AAS.  At interaction time of 4 days in acid and neutral condition, i-Cd-HAS is more stable than i-Cu-HAS with % Si left in material 95.89 % (acid media, 43.82 % (close to neutral, and 9.39 % (base media.Keywords: chemical stability, amino-silica hybrid, ionic imprinting technique.

  16. Multicenter Assessment of Gram Stain Error Rates.

    Science.gov (United States)

    Samuel, Linoj P; Balada-Llasat, Joan-Miquel; Harrington, Amanda; Cavagnolo, Robert

    2016-06-01

    Gram stains remain the cornerstone of diagnostic testing in the microbiology laboratory for the guidance of empirical treatment prior to availability of culture results. Incorrectly interpreted Gram stains may adversely impact patient care, and yet there are no comprehensive studies that have evaluated the reliability of the technique and there are no established standards for performance. In this study, clinical microbiology laboratories at four major tertiary medical care centers evaluated Gram stain error rates across all nonblood specimen types by using standardized criteria. The study focused on several factors that primarily contribute to errors in the process, including poor specimen quality, smear preparation, and interpretation of the smears. The number of specimens during the evaluation period ranged from 976 to 1,864 specimens per site, and there were a total of 6,115 specimens. Gram stain results were discrepant from culture for 5% of all specimens. Fifty-eight percent of discrepant results were specimens with no organisms reported on Gram stain but significant growth on culture, while 42% of discrepant results had reported organisms on Gram stain that were not recovered in culture. Upon review of available slides, 24% (63/263) of discrepant results were due to reader error, which varied significantly based on site (9% to 45%). The Gram stain error rate also varied between sites, ranging from 0.4% to 2.7%. The data demonstrate a significant variability between laboratories in Gram stain performance and affirm the need for ongoing quality assessment by laboratories. Standardized monitoring of Gram stains is an essential quality control tool for laboratories and is necessary for the establishment of a quality benchmark across laboratories. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  17. Effect of soaking in water and rumen digeta solutions on metabolizable energy content and chemical composition of barley seeds for use in poultry diet.

    Science.gov (United States)

    Tabatabee, S N; Sadeghi, G H; Tabeidian, S A

    2007-03-15

    An experiment was carried out to evaluate the effect of soaking in water and different rumen digesta solutions on nutritional value of dry barley seeds. Treatments were included distilled water as control and rumen digesta that diluted with distilled water to obtain 20, 40 and 60% digesta solutions. Solutions have added to 10 kg of barley seed samples to achieve final 30% moisture content. After 21 days the chemical composition and energy content of barley seed were determined. Gross energy of barley seeds did not affected by different experimental treatments. Use of 20% rumen digesta solution resulted to a significant (pcontent of barley seeds. Barley seed that treated with 40% of rumen digesta solution had highest TME and TMEn content and its different from seeds that treated with 60 and 100% rumen digesta solutions was significant (prumen digesta solutions increased crud protein, ether extract, crude fiber and ash content of barley seeds numerically.

  18. Surface staining of small intestinal biopsies

    DEFF Research Database (Denmark)

    Poulsen, Steen Seier

    1977-01-01

    Small intestinal biopsies are most often by routine examined under a stereo-microscope, prior to embedding for histological examination. This is done in order to get a view of the appearance of the mucosal pattern, especially villus configuration. The distinctness of the surface pattern however......, is improved considerably if the biopsies are stained with Alcian Green and/or PAS before they are examined. In the present paper a detailed description is given of staining of small intestinal biopsies as whole mounts. The difference between the unstained and the stained biopsies is illustrated by a few...

  19. The mechanism study of efficient degradation of hydrophobic nonylphenol in solution by a chemical-free technology of sonophotolysis

    Energy Technology Data Exchange (ETDEWEB)

    Xu, L.J.; Chu, W., E-mail: cewchu@polyu.edu.hk; Lee, Po-Heng; Wang, Jian

    2016-05-05

    Highlights: • pH influenced NP sonophotolysis by changing its existing form and light absorption. • NO{sub 3}{sup −} accelerated NP sonophotolysis while HCO{sub 3}{sup −} showed insignificant influence. • Both ortho- and meta-hydroxy-NP species can exist together thermodynamically. • Only the ortho-4-nonyl-benzoquinone is dominant thermodynamically. • The mechanism of ortho-hydroxy-NP formation was the addition of HO· and H· - Abstract: Nonylphenol is a hydrophobic endocrine disrupting compound, which can inhibit the growth of sewage bacteria in biological processes. This study investigated the degradation of 4-n-nonylphenol (NP) in water by a chemical-free technology of sonophotolysis with emphasis on the impacts of several important parameters, including light intensity, solution pH, two commonly seen inorganic ions (i.e. NO{sub 3}{sup −} and HCO{sub 3}{sup −}), and principally on the examination of degradation mechanisms. It was found that, solution pH could significantly influence both NP degradation efficiency and the synergistic effect of sonophotolytic process, where higher synergistic effect was obtained at more acidic condition. In addition, the presence of NO{sub 3}{sup −} accelerated NP degradation by both acting as a photosensitizer and providing NO{sub 2}· radicals, while HCO{sub 3}{sup −} had little effect on NP degradation. Identification of intermediates of NP degradation indicated that NP sonophotolysis was mainly initiated by the formation of hydroxy-NP, and a new intermediate di-hydroxy-NP was identified for the first time ever in this study. Through thermodynamic analysis, results indicated that both ortho- and meta-hydroxy-NP species can coexist in the solution but the ortho-4-NBZQ (4-nonyl-benzoquinone) is dominant. In addition, the mechanism of ortho-hydroxy-NP formation was suggested by the addition of HO· and H· radicals.

  20. Synthesis and characterization of nanoporous strontium-doped lanthanum cobaltite thin film using metal organic chemical solution deposition

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jun-Sik [Department of Mechanical Convergence Engineering, Hanyang University, Seoul 133-791 (Korea, Republic of); Kim, Young-Beom, E-mail: ybkim@hanyang.ac.kr [Department of Mechanical Convergence Engineering, Hanyang University, Seoul 133-791 (Korea, Republic of); Institute of Nano Science and Technology, Hanyang University, Seoul 133-791 (Korea, Republic of)

    2016-01-29

    By employing strontium as a dopant of lanthanum cobaltite (LaCoO{sub 3}), strontium-doped lanthanum cobaltite (La{sub 1−x}Sr{sub x}CoO{sub 3−δ}, LSC) thin film was fabricated using a metal organic chemical solution deposition (MOCSD) method. Lanthanum nitrate hexahydrate [La(NO{sub 3}){sub 3}6H{sub 2}O], strontium acetate [Sr(CH{sub 3}COO){sub 2}], and cobalt acetate tetrahydrate [Co(CH{sub 3}COO){sub 2}4H{sub 2}O] were used as precursors. The coating process was performed through a spin coating method on a substrate, which were then heat treated under various temperature conditions. Electrical properties, microstructures, and crystalline structures with respect to sintering temperature were analyzed. According to these analyses, the change in surface morphology, phase shift, and conductive properties were closely related, which could explain their respective behaviors. Furthermore, sintered strontium-doped lanthanum perovskite oxides showed various conductivities according to the amount of dopant. With the molar ratio of strontium that is stoichiometrically equivalent to lanthanum (La{sub 0.5}Sr{sub 0.5}CoO{sub 3−δ}) thin film showed the best conductivity in the sintering temperature range of 650–700 °C, with perovskite phases formed at this temperature condition. As the electrically conductive properties of the thin film are a function of thickness, the films were coated several times to a thickness of approximately 300 nm, with the lowest resistivity (approximately 9.06 × 10{sup −4} Ω cm) observed at the optimized sintering temperature and solution composition. - Highlights: • LSC thin film was fabricated by metal organic chemical solution deposition (MOCSD). • The film shows good agreement on the electrical conductivity of LSC by conventional methods. • The properties of LSC film are influenced by the surface morphology and crystalline phase. • Optimal molar ratio of strontium for the highest conductivity was investigated.

  1. Chemical Speciation and Bond Lengths of Organic Solutes by Core-Level Spectroscopy: pH and Solvent Influence on p-Aminobenzoic Acid.

    Science.gov (United States)

    Stevens, Joanna S; Gainar, Adrian; Suljoti, Edlira; Xiao, Jie; Golnak, Ronny; Aziz, Emad F; Schroeder, Sven L M

    2015-05-04

    Through X-ray absorption and emission spectroscopies, the chemical, electronic and structural properties of organic species in solution can be observed. Near-edge X-ray absorption fine structure (NEXAFS) and resonant inelastic X-ray scattering (RIXS) measurements at the nitrogen K-edge of para-aminobenzoic acid reveal both pH- and solvent-dependent variations in the ionisation potential (IP), 1s→π* resonances and HOMO-LUMO gap. These changes unequivocally identify the chemical species (neutral, cationic or anionic) present in solution. It is shown how this incisive chemical state sensitivity is further enhanced by the possibility of quantitative bond length determination, based on the analysis of chemical shifts in IPs and σ* shape resonances in the NEXAFS spectra. This provides experimental access to detecting even minor variations in the molecular structure of solutes in solution, thereby providing an avenue to examining computational predictions of solute properties and solute-solvent interactions. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Comparison of special stains for keratin with routine hematoxylin and eosin stain.

    Science.gov (United States)

    Rao, Roopa S; Patil, Shankargouda; Majumdar, Barnali; Oswal, Rakesh G

    2015-03-01

    Keratins are the most abundant proteins and are characteristic findings in many epithelial pathologies, making it a diagnostically important marker, both histopathologically and immunohistochemically. Since, immunohistochemistry is an expensive diagnostic tool, special stains to detect the degree of keratinization could serve as a faster and economic option. The aim of the present study was to compare the efficacy of special stains for keratin with standard hematoxylin and eosin stain (H and E). Objectives include: (i) To subject the diagnosed cases of keratin disorders to the selected special stains: Ayoub-shklar method, Dane-Herman method, Alcian blue -periodic acid Schiff 's (PAS), rapid papanicolaou (PAP) and Gram's stain. (ii) To compare the staining specificity and staining intensity of special stains with respect to routine hematoxylin and eosin (H and E) stain. (iii) To compare the efficacy of special stains to routine H and E stain in identification of the type of keratin present in the selected cases. A total of 80 cases of known pathology for keratin were retrieved from the department archive, which included 10 each of normal gingiva, hyperkeratosis, squamous papilloma, verrucous hyperplasia, verrucous carcinoma, well-differentiated squamous cell carcinoma, orthokeratinized odontogenic cyst and keratocystic odontogenic tumors. Six sections of 4 µ each from the paraffin blocks were made, stained with H and E and the special stains and these were evaluated by 2 pathologists based on the modified scoring criteria from Rahma Al-Maaini and Philip Bryant 2008. The results were tabulated using Chi square and kappa statistics. The statistical values for identification of the type of keratinization was insignificant showing that ortho and parakeratinized epithelia could be correctly identified by both H and E as well as all the special stains. Furthermore, all the special stains showed a positive result and statistical significance (P < 0.001) with respect to

  3. Gram staining apparatus for space station applications

    Science.gov (United States)

    Molina, T. C.; Brown, H. D.; Irbe, R. M.; Pierson, D. L.

    1990-01-01

    A self-contained, portable Gram staining apparatus (GSA) has been developed for use in the microgravity environment on board the Space Station Freedom. Accuracy and reproducibility of this apparatus compared with the conventional Gram staining method were evaluated by using gram-negative and gram-positive controls and different species of bacteria grown in pure cultures. A subsequent study was designed to assess the performance of the GSA with actual specimens. A set of 60 human and environmental specimens was evaluated with the GSA and the conventional Gram staining procedure. Data obtained from these studies indicated that the GSA will provide the Gram staining capability needed for the microgravity environment of space.

  4. Mechanisms of superficial micropunctate corneal staining with sodium fluorescein: the contribution of pooling.

    Science.gov (United States)

    Bandamwar, Kalika L; Garrett, Qian; Papas, Eric B

    2012-04-01

    To establish if sodium fluorescein (SFL) dye accumulation within intercellular spaces on the ocular surface contributes to the appearance of superficial punctate corneal staining. Thirteen subjects bilaterally wore PureVision™ lenses that had been pre-soaked in ReNu MultiPlus® multipurpose solution. After 1h of lens wear, corneal staining with SFL was assessed using a standard slit-lamp technique. Participants who presented with bilateral, corneal staining were selected for further evaluation. A randomly selected eye was rinsed with saline three times. Fellow eyes (control) received no rinsing. After each rinse, the appearance of SFL staining was recorded without any further instillation of the dye. To eliminate any confounding effects of staining due to residual fluorescein in the tear menisci, corneal staining was induced in freshly excised, isolated, rabbit eyes by topical administration of 0.001% PHMB and staining, rinsing and grading were performed as above. Nine out of 13 subjects presented with bilateral diffuse corneal staining (mean grade±SD: 2.4±0.7). The mean staining grades in test and control eyes respectively after each of the three rinses were (1) 2.41±0.41, 2.25±0.69 (p=0.9); (2) 2.34±0.79, 2.1±0.83 (p=0.8); and (3) 1.71±0.65, 1.60±0.79 (p=0.6) there was no significant reduction in staining with rinsing (p>0.05) and no difference was observed between test and control eyes at any sampling-point. Similar observations made in ex vivo rabbit eyes replicated these results. Pooling or accumulation of SFL solution within intercellular spaces does not appear to contribute to the appearance of superficial micropunctate corneal staining. Copyright © 2011 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

  5. The Luna stain, an improved selective stain for detection of microsporidian spores in histologic sections

    Science.gov (United States)

    Peterson, Tracy S.; Spitsbergen, Jan M.; Feist, Stephen W.; Kent, Michael L.

    2014-01-01

    Microsporidia in histologic sections are most often diagnosed by observing spores in host tissues. Spores are easy to identify if they occur in large aggregates or xenomas when sections are stained with hematoxylin and eosin (H&E). However, individual spores are not frequently detected in host tissues with conventional H&E staining, particularly if spores are scattered within the tissues, areas of inflammation or small spores in nuclei (i.e., Nucleospora salmonis). Hence, a variety of selective stains that enhance visualization of spores are recommended. We discovered that the Luna stain, used to highlight eosinophils, red blood cells and chitin in arthropods and other invertebrates, also stains spores of Pseudoloma neurophilia. We compared this stain to the Gram, Fite’s acid fast, Giemsa, and H&E stains on eight aquatic microsporidian organisms that were readily available in our two laboratories: Loma salmonae, Glugea anomala, Pseudoloma neurophilia, Pleistophora hyphessobryconis, Pleistophora vermiformis, Glugea sp., Steinhausia mytilovum and an unidentified microsporidian from E. sinensis, UK. Based on tinctorial properties and background staining, the Luna stain performed better for detection of 6 of the 8 microsporidia. Gram stain was superior for the two microsporidia from invertebrates, Steinhausia mytilovum and the unidentified microsporidian from E. sinensis. PMID:21848126

  6. Comparative study of ZnSe thin films deposited from modified chemical bath solutions with ammonia-containing and ammonia-free precursors

    International Nuclear Information System (INIS)

    Chen Liangyan; Zhang Daoli; Zhai Guangmei; Zhang Jianbing

    2010-01-01

    Ammonia is one of the complexing agents which are the most commonly used in the precursors of ZnSe thin films by chemical bath deposition, but its high volatility may be harmful to human beings and environments. In our experiments, ZnSe films were obtained from modified chemical solutions with ammonia-containing and ammonia-free precursors. X-ray diffraction, field-emission scanning electron microscope (FSEM), and absorption spectrum were applied to investigate the microstructure, morphology and optical properties of the samples obtained from both growth conditions, which were investigated in this work. The ammonia-free chemical bath deposited ZnSe films showed comparable properties with the ammonia-containing ones, indicating that ZnSe films from ammonia-free chemical solution may be preferred buffer layer in thin film solar cells with less environmental contamination.

  7. A Multiple Time-Step Finite State Projection Algorithm for the Solution to the Chemical Master Equation

    National Research Council Canada - National Science Library

    Munsky, Brian; Khammash, Mustafa

    2006-01-01

    At the mesoscopic scale, chemical processes have probability distributions that evolve according to an infinite set of linear ordinary differential equations known as the chemical master equation (CME...

  8. In-Situ Synchrotron X-ray Study of the Phase and Texture Evolution of Ceria and Superconductor Films Deposited by Chemical Solution Method

    DEFF Research Database (Denmark)

    Yue, Zhao; Grivel, Jean-Claude; He, Dong

    2012-01-01

    In situ synchrotron x-ray diffraction is used to study the phase and texture formation of ceria based films and superconductor films deposited by the chemical solution method on technical substrates. Combined analysis using in situ synchrotron x-ray diffraction, thermogravimetry/differential ther......In situ synchrotron x-ray diffraction is used to study the phase and texture formation of ceria based films and superconductor films deposited by the chemical solution method on technical substrates. Combined analysis using in situ synchrotron x-ray diffraction, thermogravimetry...

  9. Influence of lanthanium atoms on the physico-chemical properties of GeS0,5Se0,5 solid solutions

    International Nuclear Information System (INIS)

    Murguzov, M.I.; Alakbarov, A.S.; Bayramov, R.B.

    2010-01-01

    By the methods of physical-chemical analysis (DTA, X-ray, MSA, as well as measurement of microhardness and density determination) the influence of La on the physico-chemical properties of solid solutions (GeS 0 ,5Se 0 ,5) 1 -x(La) x was studied and its microdiagram was plotted. At room temperature the GeS 0 ,5Se 0 ,5 based solid solid solution extent to 4 at. percent La. The dependence of lanthane microhardness was studied

  10. Low-temperature transport properties of chemical solution deposited polycrystalline La0.7Sr0.3MnO3 ferromagnetic films under a magnetic field

    International Nuclear Information System (INIS)

    Zhu, Junyu; Chen, Ying; Xu, Wenfei; Yang, Jing; Bai, Wei; Wang, Genshui; Duan, Chungang; Tang, Zheng; Tang, Xiaodong

    2011-01-01

    Polycrystalline La 0.7 Sr 0.3 MnO 3 (LSMO) films were prepared on SiO 2 /Si (001) substrates by chemical solution deposition technique. Electrical and magnetic properties of LSMO were investigated. A minimum phenomenon in resistivity is found at the low temperature ( 0.7 Sr 0.3 MnO 3 films were grown by a modified chemical solution deposition route. → High quality LSMO thin films were prepared directly onto SiO 2 /Si substrates. → Abnormality in resistivity of LSMO films at low temperatures was studied in detail. → The abnormality was mainly attributed to Kondo-like spin dependent scattering.

  11. Enhanced magnetic properties of chemical solution deposited BiFeO3 thin film with ZnO buffer layer

    International Nuclear Information System (INIS)

    Rajalakshmi, R.; Kambhala, Nagaiah; Angappane, S.

    2012-01-01

    Highlights: ► Enhanced magnetization of BiFeO 3 is important for strong magnetoelectric coupling. ► BiFeO 3 film with ZnO buffer layer was successfully synthesized by chemical method. ► Magnetization of BiFeO 3 has increased by more than 10 times with ZnO buffer layer. ► A mechanism for enhancement in ferromagnetism of BiFeO 3 film is proposed. - Abstract: Magnetic properties of BiFeO 3 films deposited on Si substrates with and without ZnO buffer layer have been studied in this work. We adopted the chemical solution deposition method for the deposition of BiFeO 3 as well as ZnO films. The x-ray diffraction measurements on the deposited films confirm the formation of crystalline phase of BiFeO 3 and ZnO films, while our electron microscopy measurements help to understand the morphology of few micrometers thick films. It is found that the deposited ZnO film exhibit a hexagonal particulate surface morphology, whereas BiFeO 3 film fully covers the ZnO surface. Our magnetic measurements reveal that the magnetization of BiFeO 3 has increased by more than ten times in BiFeO 3 /ZnO/Si film compared to BiFeO 3 /Si film, indicating the major role played by ZnO buffer layer in enhancing the magnetic properties of BiFeO 3 , a technologically important multiferroic material.

  12. Chemically modified Moringa oleifera seed husks as low cost adsorbent for removal of copper from aqueous solution

    Science.gov (United States)

    Ghafar, Faridah; Mohtar, Aminullah; Sapawe, Norzahir; Hadi, Norulakmal Nor; Salleh, Marmy Roshaidah Mohd

    2017-12-01

    Moringa oleifera husks (MOH) are an agricultural byproduct that may have potential as adsorbent for removal of heavy metal ions in wastewater such as copper (Cu2+). The release of Cu2+ to the environment by the mining and electroplating industries cause a major problem because it is toxic and can cause liver and kidney problems. Hence, it is important to remove copper before the wastewater can be discharged to the environment. In order to increase the adsorption capacity, the MOH was chemically modified using citric acid. The raw and modified MOH were analyzed using Fourier Transform Infra-Red (FTIR) for identification of functional groups present at the adsorbent surface. The adsorption study was carried out using the batch technique in water bath shaker investigating different parameters; adsorbent dosage (30 - 70 g/L), initial concentration of copper (30 - 150 mg/L), contact time (2 - 90 min), temperature (27 - 60 °C) at constant agitation of 100 rpm. The concentrations of copper in aqueous solution before and after the adsorption process was analyzed using Atomic Absorption Spectrum (AAS). The highest percentage removal of copper was found at 10g/L of adsorbent dosage with 30 mg/L of initial concentration and temperature 30 °C. It was also observed that the adsorption of copper by MOH was approaching to equilibrium at 60 min of reaction time. From the FTIR analysis, it was found that the MOH contains hydroxyl, carboxyl and amine groups. The high adsorption capacity of modified MOH to remove copper from aqueous solution makes it preferable and attractive alternative to commercial adsorbent.

  13. Preparation of colloidal gold for staining proteins electrotransferred onto nitrocellulose membranes.

    Science.gov (United States)

    Yamaguchi, K; Asakawa, H

    1988-07-01

    This paper describes a simple method of preparing colloidal gold for staining protein blots. Colloidal gold was prepared from 0.005 or 0.01% HAuCl4 by the addition of formalin as a reductant and potassium hydroxide. Staining of small cell carcinoma tissue extract blotted onto nitrocellulose membranes with this colloidal gold solution resulted in the appearance of a large number of clear wine-red bands. The sensitivity of gold staining was 60 times higher than that of Coomassie brilliant blue staining and almost comparable to that of silver staining of proteins in polyacrylamide gel. The sensitivity of this method was also satisfactory in comparison with that of enzyme immunoblotting. The colloidal gold prepared by this method is usable for routine work.

  14. Selection and application of exterior stains for wood

    Science.gov (United States)

    R. Sam. Williams; William C. Feist

    1999-01-01

    Exterior stains for wood protect the wood surface from sunlight and moisture. Because stains are formulated to penetrate the wood surface, they are not prone to crack or peel as can film-forming finishes, such as paints. This publication describes the properties of stains and wood, methods for applying stains, and the expected service life of stains.

  15. Improving chemical solution deposited YBa 2Cu 3O 7- δ film properties via high heating rates

    Science.gov (United States)

    Siegal, M. P.; Dawley, J. T.; Clem, P. G.; Overmyer, D. L.

    2003-12-01

    The superconducting and structural properties of YBa 2Cu 3O 7- δ (YBCO) films grown from chemical solution deposited (CSD) metallofluoride-based precursors improve by using high heating rates to the desired growth temperature. This is due to avoiding the nucleation of undesirable a-axis grains at lower temperatures, from 650 to 800 °C in p(O 2)=0.1%. Minimizing time spent in this range during the temperature ramp of the ex situ growth process depresses a-axis grain growth in favor of the desired c-axis orientation. Using optimized conditions, this results in high-quality YBCO films on LaAlO 3(1 0 0) with Jc(77 K) ∼ 3 MA/cm 2 for films thicknesses ranging from 60 to 140 nm. In particular, there is a dramatic decrease in a-axis grains in coated-conductors grown on CSD Nb-doped SrTiO 3(1 0 0) buffered Ni(1 0 0) tapes.

  16. Surface modeling and chemical solution deposition of SrO(SrTiO3)n Ruddlesden-Popper phases

    International Nuclear Information System (INIS)

    Zschornak, M.; Gemming, S.; Gutmann, E.; Weissbach, T.; Stoecker, H.; Leisegang, T.; Riedl, T.; Traenkner, M.; Gemming, T.; Meyer, D.C.

    2010-01-01

    Strontium titanate (STO) is a preferred substrate material for functional oxide growth, whose surface properties can be adjusted through the presence of Ruddlesden-Popper (RP) phases. Here, density functional theory (DFT) is used to model the (1 0 0) and (0 0 1) surfaces of SrO(SrTiO 3 ) n RP phases. Relaxed surface structures, electronic properties and stability relations have been determined. In contrast to pure STO, the near-surface SrO-OSr stacking fault can be employed to control surface roughness by adjusting SrO and TiO 2 surface rumpling, to stabilize SrO termination in an SrO-rich surrounding or to increase the band gap in the case of TiO 2 termination. RP thin films have been epitaxially grown on (0 0 1) STO substrates by chemical solution deposition. In agreement with DFT results, the fraction of particular RP phases n = 1-3 changes with varying heating rate and molar ratio Sr:Ti. This is discussed in terms of bulk formation energy.

  17. Physical and Chemical Characterization of Fat and Oil Deposits in Mashhad City Sewer Lines and the Solutions Developed

    Directory of Open Access Journals (Sweden)

    Mahdi kamali

    2017-01-01

    Full Text Available Formation of oil, fat, and grease deposits in sewer pipelines is a major concern as they result in sewage overflow and pose health problems. Analysis of two sample deposits collected from the sewer lines of Imam Reza Street in the city of Mashhad suggested that the chemical reactions promoted by edible oils in the sewer lines lead to the formation of insoluble soap and deposits. Being sticky, the deposits accumulate over time to eventually block the lines. The analysis also showed that the moisture content of the samples ranged between 50‒62%, indicating that water does not play a main role in their formation. The samples were also found to contain 61.78% and 84.35% saturated fatty acids, with palmitic acid being the dominant one. Calcium was the main metal in the samples, which is due to both water hardness and corrosion of the sewer lines. Based on the results obtained, the origin of these deposits, and the relevant protocols for the management of oil and fat wastes, solutions were proposed to prevent deposit formation and sewer line clogging that suit the special cultural and environmental conditions of the city. These proposals are under consideration for implementation in the region.

  18. Hybrid quantum and classical methods for computing kinetic isotope effects of chemical reactions in solutions and in enzymes.

    Science.gov (United States)

    Gao, Jiali; Major, Dan T; Fan, Yao; Lin, Yen-Lin; Ma, Shuhua; Wong, Kin-Yiu

    2008-01-01

    A method for incorporating quantum mechanics into enzyme kinetics modeling is presented. Three aspects are emphasized: 1) combined quantum mechanical and molecular mechanical methods are used to represent the potential energy surface for modeling bond forming and breaking processes, 2) instantaneous normal mode analyses are used to incorporate quantum vibrational free energies to the classical potential of mean force, and 3) multidimensional tunneling methods are used to estimate quantum effects on the reaction coordinate motion. Centroid path integral simulations are described to make quantum corrections to the classical potential of mean force. In this method, the nuclear quantum vibrational and tunneling contributions are not separable. An integrated centroid path integral-free energy perturbation and umbrella sampling (PI-FEP/UM) method along with a bisection sampling procedure was summarized, which provides an accurate, easily convergent method for computing kinetic isotope effects for chemical reactions in solution and in enzymes. In the ensemble-averaged variational transition state theory with multidimensional tunneling (EA-VTST/MT), these three aspects of quantum mechanical effects can be individually treated, providing useful insights into the mechanism of enzymatic reactions. These methods are illustrated by applications to a model process in the gas phase, the decarboxylation reaction of N-methyl picolinate in water, and the proton abstraction and reprotonation process catalyzed by alanine racemase. These examples show that the incorporation of quantum mechanical effects is essential for enzyme kinetics simulations.

  19. Characterization of paint layers and stained glasses

    International Nuclear Information System (INIS)

    Biagi Maino, D.; Ciancabilla, L.; Gandolfi, G.; Maino, G.; Bruni, S.; Ferriani, S.; Visparelli, D.

    2000-01-01

    Due to the higher magnification with respect to traditional optical microscopes, the scanning electron microscopy (SEM) has been extensively applied in recent years to the investigation of elemental composition of many different types of artistic objects. The back-scattered and secondary electrons produced when the SEM electron beam hits the sample can be detected and converted in electronic signals which give rise to images of the scanned area. These images can be recorded in digital format and stored on a computer for subsequent processing. Moreover, in addition to the back-scattered and secondary electrons, the impact of the electron beam on the sample produces a X-ray spectrum, which can be further processed and analysed using an X-ray spectrometer coupled to the SEM. Therefore, it is possible to yield the chemical composition of the sample, analogously to the X-ray fluorescence analysis. Moreover, the transmission electron microscopy (TEM) can be applied to the characterization of paint layers, making ultra-thin sections in which the paint and ground layers are preserved intact. In comparison with usual SEM measurements, the TEM technique is more precise, because of the higher spatial resolution in both the microanalysis and diffraction modes, of the order of 10-20 nm. This precision allows unique identification of each component in the layer and determination of the crystallographic structure, thus characterizing even the smallest particles of each pigment and pointing out minor components. It is then possible to establish whether a pigment is natural, manufactured, its origin as well as approximate datations. In this work, we describe the research activities performed in the laboratory recently established at the ENEA (Italian National Agency for New Technology, Energy and Environment) Applied Physics Division, where dedicated SEM and TEM are connected by a suitable imaging system to a powerful computing system for image acquisition and processing. Use has

  20. Comparison of algorithms for blood stain detection applied to forensic hyperspectral imagery

    Science.gov (United States)

    Yang, Jie; Messinger, David W.; Mathew, Jobin J.; Dube, Roger R.

    2016-05-01

    Blood stains are among the most important types of evidence for forensic investigation. They contain valuable DNA information, and the pattern of the stains can suggest specifics about the nature of the violence that transpired at the scene. Early detection of blood stains is particularly important since the blood reacts physically and chemically with air and materials over time. Accurate identification of blood remnants, including regions that might have been intentionally cleaned, is an important aspect of forensic investigation. Hyperspectral imaging might be a potential method to detect blood stains because it is non-contact and provides substantial spectral information that can be used to identify regions in a scene with trace amounts of blood. The potential complexity of scenes in which such vast violence occurs can be high when the range of scene material types and conditions containing blood stains at a crime scene are considered. Some stains are hard to detect by the unaided eye, especially if a conscious effort to clean the scene has occurred (we refer to these as "latent" blood stains). In this paper we present the initial results of a study of the use of hyperspectral imaging algorithms for blood detection in complex scenes. We describe a hyperspectral imaging system which generates images covering 400 nm - 700 nm visible range with a spectral resolution of 10 nm. Three image sets of 31 wavelength bands were generated using this camera for a simulated indoor crime scene in which blood stains were placed on a T-shirt and walls. To detect blood stains in the scene, Principal Component Analysis (PCA), Subspace Reed Xiaoli Detection (SRXD), and Topological Anomaly Detection (TAD) algorithms were used. Comparison of the three hyperspectral image analysis techniques shows that TAD is most suitable for detecting blood stains and discovering latent blood stains.

  1. Surface engineering of biaxial Gd2Zr2O7 thin films deposited on Ni–5at%W substrates by a chemical solution method

    DEFF Research Database (Denmark)

    Yue, Zhao; Grivel, Jean-Claude; Liu, Min

    2012-01-01

    crystal structure along the film thickness observed by a transmission electron microscope. On the basis of the enhanced understanding of the crystallization processes, we demonstrate a possibility of engineering the surface morphology and texture in the film deposited on technical substrates using...... a chemical solution deposition route....

  2. Microspectroscopic imaging of solution plasma: How do its physical properties and chemical species evolve in atmospheric-pressure water vapor bubbles?

    Science.gov (United States)

    Yui, Hiroharu; Banno, Motohiro

    2018-01-01

    In this article, we review the development of scientific instruments for obtaining information on the evolution of physical properties and chemical species of solution plasma (SP). When a pulsed high voltage is applied between electrodes immersed in an aqueous solution, SP is formed in water vapor bubbles transiently generated in the solution under atmospheric pressure. To clarify how SP emerges in water vapor bubbles and is sustained in solutions, an instrument with micrometer spatial resolution and nanosecond temporal resolution is required. To meet these requirements, a microscopic system with a custom-made optical discharge cell was newly developed, where the working distance between the SP and the microscopic objective lens was minimized. A hollow electrode equipped in the discharge cell also enabled us to control the chemical composition in water vapor bubbles. To study the spatial and temporal evolutions of chemical species in micrometer and nano- to microsecond regions, a streak camera with a spectrometer and a CCD detector with a time-gated electronic device were combined with the microscope system. The developed instrument is expected to contribute to providing a new means of developing new schemes for chemical reactions and material syntheses.

  3. Superconducting Dy1-x(Gd,Yb)xBa2Cu3O7-δ thin films made by Chemical Solution Deposition

    DEFF Research Database (Denmark)

    Opata, Yuri Aparecido; Wulff, Anders Christian; Hansen, Jørn Otto Bindslev

    2016-01-01

    Dy1-x(Gd or Yb)xBa2Cu3O7-δ samples were prepared using chemical solution deposition (CSD), based on trifluoroacetate metal-organic decomposition (MOD) methods. X-ray diffraction results demonstrated the formation of the RE123 superconducting phase with a strong in-plane and out-of-plane texture. c...

  4. SrAl12O19 thin films by chemical solution deposition and their use as buffer layers for oriented growth of hexagonal ferrites

    Czech Academy of Sciences Publication Activity Database

    Buršík, Josef; Uhrecký, Róbert; Kaščáková, Dorota; Kužel, R.; Holý, V.; Dopita, M.

    2016-01-01

    Roč. 616, OCT (2016), s. 228-237 ISSN 0040-6090 R&D Projects: GA ČR(CZ) GA14-18392S Institutional support: RVO:61388980 Keywords : Chemical solution deposition * Hexagonal aluminates * Hexagonal ferrites Subject RIV: CA - Inorganic Chemistry Impact factor: 1.879, year: 2016

  5. M-type ferrites as template layers for the growth of oriented Y-type ferrites through chemical solution deposition method

    Czech Academy of Sciences Publication Activity Database

    Buršík, Josef; Uhrecký, Róbert; Kaščáková, Dorota; Slušná, Michaela; Dopita, M.; Kužel, R.

    2016-01-01

    Roč. 36, č. 13 (2016), s. 3173-3183 ISSN 0955-2219 R&D Projects: GA ČR(CZ) GA14-18392S Institutional support: RVO:61388980 Keywords : Chemical solution deposition * Hexagonal ferrites * Lattice misfit * Seed layer * Thin films Subject RIV: CA - Inorganic Chemistry Impact factor: 3.411, year: 2016

  6. Comparism of Various Staining Techniques in the Diagnosis of ...

    African Journals Online (AJOL)

    SITWALA COMPUTERS

    external intermediate host, usually an animal, in which sporogenesis and oocyst ... the parasite was detected in 111 of the samples stained,. 100(90.0%) of which .... screen stained slide was the auramine fluorochrome stain. The widely used ...

  7. Contribution to research on the metabolism of fission product. Studies on the physico-chemical state and the metabolic fate of radio-cerium solution

    International Nuclear Information System (INIS)

    Aeberhardt, A.

    1961-01-01

    This paper describes a study of the physico-chemical state of radio-cerium in dilute solutions on the tracer scale, as a function of the pH of the solution. The way in which this radioelement is transported in the blood is studied in vitro and in vivo, with reference to the ionic or colloidal state of the radio-cerium used. The distribution of cerium amongst the various components of the blood is studied by a new method of blood fractionation and by paper electrophoresis. Evidence of a cerium globulin connection is shown in the case of ionic cerium. A study of the initial distribution of radio-cerium in rats, after intravenous administration of ionic or colloidal solutions, shows considerable differences according to the physico-chemical state of the cerium injected. (author) [fr

  8. YBa{sub 2}Cu{sub 3}O{sub 7-x} thin films prepared by chemical solution deposition

    Energy Technology Data Exchange (ETDEWEB)

    Apetrii, Claudia

    2009-11-25

    The discovery of superconductivity in ceramic materials by Bednorz and Mueller in early 1987, immediately followed by Wu et al., who showed that YBa{sub 2}Cu{sub 3}O{sub 7-x} (YBCO) becomes superconducting (92 K) well above the boiling point of nitrogen (77 K) created a great excitement in superconductivity research. Potential applications of high T{sub c}-superconductors require large critical currents and high-applied magnetic fields. Effective ways to increase the critical current density at high magnetic fields in YBCO are the introduction of nanoparticles and chemical substitution of yttrium by other rare earth elements. Since low costs and environmental compatibility are essential conditions for the preparation of long length YBCO films, the cost effective chemical solution deposition (CSD) procedure was selected, given that no vacuum technology is required. To reveal the flexibility and the good optimization possibilities of the CSD approach two main processes were chosen for comparison: a fluorine-free method, namely the polymer-metal precursor technique, and a fluorine-based method, the metalorganic deposition (MOD) using the trifluoroacetates (TFA) technique. Sharp transition temperature widths {delta}T{sub c} of 1.1 K for the polymer metal method, 0.8 K for TFA method and critical current densities J{sub c} of {approx}3.5 MA/cm{sup 2} shows that high quality YBCO thin films can be produced using both techniques. Especially interesting is the magnetic field dependence of the critical current density J{sub c}(B) of the Y(Dy)BCO (80 %) films showing that for the lower magnetic fields the critical current density J{sub c}(B) is higher for a standard YBCO film, but at fields higher than 4.5 T the critical current density J{sub c}(B) of Y(Dy)BCO is larger than that for the YBCO. Above 8 T, J{sub c}(B) of the Y(Dy)BCO film is more than one order of magnitude higher than in pure YBCO film. (orig.)

  9. Pleural and Pulmonary Staining at Inferior Phrenic Arteriography Mimicking a Tumor Staining of Hepatocellular Carcinoma

    International Nuclear Information System (INIS)

    Lee, Deok Hee; Hwang, Jae Cheol; Lim, Soo Mee; Yoon, Hyun-Ki; Sung, Kyu-Bo; Song, Ho-Young

    2000-01-01

    Purpose: To describe the findings of pleural and pulmonary staining of the inferior phrenic artery, which can be confused with tumor staining during transarterial chemoembolization (TACE) of hepatoma.Methods: Fifteen patients who showed pleural and pulmonary staining without relationship to hepatic masses at inferior phrenic arteriography were enrolled. The staining was noted at initial TACE (n = 8), at successive TACE (n = 5), and after hepatic surgery (n = 2). The angiographic pattern, the presence of pleural change on computed tomography (CT), and clinical history were evaluated.Results: Draining pulmonary veins were seen in all cases. The lower margin of the staining corresponded to the lower margin of the pleura in 10 patients. CT showed pleural and/or pulmonary abnormalities in all cases. After embolization of the inferior phrenic artery, the accumulation of iodized oil in the lung was noted.Conclusion: Understanding the CT and angiographic findings of pleural and pulmonary staining during TACE may help differentiate benign staining from tumor staining

  10. Anodic processes in the chemical and electrochemical etching of Si crystals in acid-fluoride solutions: Pore formation mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Ulin, V. P.; Ulin, N. V.; Soldatenkov, F. Yu., E-mail: f.soldatenkov@mail.ioffe.ru [Ioffe Physical–Technical Institute (Russian Federation)

    2017-04-15

    The interaction of heavily doped p- and n-type Si crystals with hydrofluoric acid in the dark with and without contact with metals having greatly differing work functions (Ag and Pd) is studied. The dependences of the dissolution rates of Si crystals in HF solutions that contain oxidizing agents with different redox potentials (FeCl{sub 3}, V{sub 2}O{sub 5} and CrO{sub 3}) on the type and level of silicon doping are determined. Analysis of the experimental data suggests that valence-band holes in silicon are not directly involved in the anodic reactions of silicon oxidation and dissolution and their generation in crystals does not limit the rate of these processes. It is also shown that the character and rate of the chemical process leading to silicon dissolution in HF-containing electrolytes are determined by the interfacial potential attained at the semiconductor–electrolyte interface. The mechanism of electrochemical pore formation in silicon crystals is discussed in terms of selfconsistent cooperative reactions of nucleophilic substitution between chemisorbed fluorine anions and coordination- saturated silicon atoms in the crystal subsurface layer. A specific feature of these reactions for silicon crystals is that vacant nonbonding d{sup 2}sp{sup 3} orbitals of Si atoms, associated with sixfold degenerate states corresponding to the Δ valley of the conduction band, are involved in the formation of intermediate complexes. According to the suggested model, the pore-formation process spontaneously develops in local regions of the interface under the action of the interfacial potential in the adsorption layer and occurs as a result of the detachment of (SiF{sub 2}){sub n} polymer chains from the crystal. Just this process leads to the preferential propagation of pores along the <100> crystallographic directions. The thermodynamic aspects of pore nucleation and the effect of the potential drop across the interface, conduction type, and free-carrier concentration

  11. Preparation of SmBiO{sub 3} buffer layer on YSZ substrate by an improved chemical solution deposition route

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Xiaolei [Key Laboratory of Advanced Technologies of Materials (Ministry of Education of China), Superconductivity and New Energy R& D Center, Mail Stop 165#, Southwest Jiaotong University, Chengdu, Sichuan 610031 (China); Pu, Minghua, E-mail: mhpu@home.swjtu.edu.cn [Key Laboratory of Advanced Technologies of Materials (Ministry of Education of China), Superconductivity and New Energy R& D Center, Mail Stop 165#, Southwest Jiaotong University, Chengdu, Sichuan 610031 (China); Zhao, Yong [Key Laboratory of Advanced Technologies of Materials (Ministry of Education of China), Superconductivity and New Energy R& D Center, Mail Stop 165#, Southwest Jiaotong University, Chengdu, Sichuan 610031 (China); School of Materials Science and Engineering, University of New South Wale, Sydney, NSW 2052 (Australia)

    2016-12-15

    Highlights: • The proper conditions for SBO growth are 794 °C for 60 min in flowing Ar gas, the temperature of epitaxial growth is relatively low. • The total time by SSD technique for organic solvent removing, salts decomposition and layer growth is not up to 2 h, which are much less than that needed for traditional CSD of over 10 h. • SBO layer on YSZ prepared by SSD technique are suitable for the growth of YBCO, The results may be the usable reference for continuous preparation of SBO buffer layer on IBAD-YSZ/Ni-based alloy tapes. - Abstract: A quick route for chemical solution deposition (CSD) has been developed to prepare SmBiO{sub 3} (SBO) layers on yttria stabilized zirconia (YSZ) substrates rapidly by using of solid state decomposition (SSD) technique. The proper conditions for volatilization of lactic acid, which as solvent in precursor coated layer, and SBO growth are 115°C for 30 min and 794°C for 60 min in flowing Ar gas. The coated layers are amorphous structure of mixture oxides and quasi-crystal structure of SBO before and after growth, respectively. The total time by this quick CSD route for organic solvent volatilization, salts decomposed and layer growth is not up to 2 h, which are much less than that needed for traditional CSD of over 10 h. SBO layer is directly epitaxial growth on YSZ substrate without any lattice rotation. SBO layer prepared by this quick route as well as that by traditional route are suitable for the growth of YBCO. The superconducting transition temperature and critical current density of the coated YBCO layer on SBO/YSZ obtained by this quick route are up to 90 K and 1.66 MA/cm{sup 2}. These results may be the usable reference for continuous preparation of SBO buffer layer on IBAD-YSZ/Ni-based alloy tapes.

  12. Melamine derivatives as effective corrosion inhibitors for mild steel in acidic solution: Chemical, electrochemical, surface and DFT studies

    Science.gov (United States)

    Verma, Chandrabhan; Haque, J.; Ebenso, Eno E.; Quraishi, M. A.

    2018-06-01

    In present study two condensation products of melamine (triazine) and glyoxal namely, 2,2-bis(4,6-diamino-1,3,5-triazin-2-ylamino)acetaldehyde (ME-1) and (N2,N2‧E,N2,N2‧E)-N2,N2‧-(ethane-1,2-diylidene)-bis-(1,3,5-triazine-2,4,6-triamine) (ME-2) are tested as mild steel corrosion inhibitors in acidic solution (1M HCl). The inhibition efficiency of ME-1 and ME-2 increases with increase in their concentrations and maximum values of 91.47% and 94.88% were derived, respectively at 100 mgL-1 (34.20 × 10-5 M) concentration. Adsorption of ME-1 and ME-2 on the surface of metal obeyed the Langmuir adsorption isotherm. Polarization investigation revealed that ME-1 and ME-2 act as mixed type inhibitors with minor cathodic prevalence. The chemical and electrochemical analyses also supported by surface characterization methods where significant smoothness in the surface morphologies was observed in the images of SEM and AFM spectra. Several DFT indices such as EHOMO and ELUMO, ΔE, η, σ, χ, μ and ΔN were derived for both ME-1 and ME-2 molecules and correlated with experimental results. The DFT studies have also been carried out for protonated or cationic form of the inhibitor molecules by considering that in acidic medium the heteroatoms of organic inhibitors easily undergo protonation. The experimental and density functional theory (DFT) studies (neutral and protonated) were in good agreement.

  13. A comparative assessment of commonly employed staining ...

    African Journals Online (AJOL)

    Following an increase in the number of reports of Cryptosporidium infections and the problems encountered in detecting these organisms in faecal smears, a comparative assessment of a modification of the Sheather's flotation technique and other commonly employed staining procedures proved the modified Sheather's ...

  14. Photoacoustic imaging of port-wine stains

    NARCIS (Netherlands)

    Kolkman, Roy G. M.; Mulder, Miranda J.; Glade, Conrad P.; Steenbergen, Wiendelt; van Leeuwen, Ton G.

    2008-01-01

    BACKGROUND AND OBJECTIVE: To optimize laser therapy of port-wine stains (PWSs), information about the vasculature as well as lesion depth is valuable. In this study we investigated the use of photoacoustic imaging (PAI) to obtain this information. STUDY DESIGN/MATERIALS AND METHODS: PAI uses pulsed

  15. Photoacoustic Imaging of Port-Wine Stains

    NARCIS (Netherlands)

    Kolkman, R.G.M.; Mulder, M.J.; Mulder, Miranda J.; Glade, Conrad P.; Steenbergen, Wiendelt; van Leeuwen, Ton

    2008-01-01

    Background and Objective: To optimize laser therapy of port-wine stains (PWSs), information about the vasculature as well as lesion depth is valuable. In this study we investigated the use of photoacoustic imaging (PAI) to obtain this information. - Study Design/Materials and Methods: PAI uses

  16. Creatinine and creatininium cation in water solution. Tautomerism and quantitative interpretation of the solution acidity effect on 1H, 13C and 1:4N NMR chemical shifts

    International Nuclear Information System (INIS)

    Kotsyubynskyy, D.; Molchanov, S.; Gryff-Keller, A.

    2004-01-01

    1 H, 13 C and 1 :4N NMR chemical shifts for creatinine in water solution of various acidity have been measured. Analysis of these data enabled determination of the acidity constant of creatininium cation and the chemical shifts of the neutral and protonated forms of creatinine. Molecular energies and carbon and nitrogen magnetic shielding constants for various tautomeric structures of the investigated species have been calculated using the quantum chemistry method GIAO DFT B3LYP/6-311++G(2d,p). Compilation of the available experimental and theoretical results has provided additional information on the problem of tautomerism of this important biological molecule. (author)

  17. The effect of corrosion on stained glass windows

    Directory of Open Access Journals (Sweden)

    Laissner, Johanna

    1996-06-01

    Full Text Available Stained glass windows belong to the most important cultural heritage of Europe. Within the last decades a disastrous deterioration took place. The wonderful stained glass windows and their glass paintings as pieces of art are acutely menaced by environmental corrosive influences. This corrosion process is a very complex reaction which is not only influenced by temperature and humidity changes but also by gaseous pollutants like sulfur dioxide, nitrogen oxides or ozone, by dust and air, microorganisms as well as synergetic interactions. Strongly affected by these environmental attacks are medieval stained glasses due to their chemical composition. They have a low content in silica and high contents of modifier ions (e.g. potassium and calcium. The corrosion phenomena can range from predominantly pitting on the surface to the formation of thick corrosion crusts which are turning the panel opaque and thus reducing strongly the transparency of the windows. In order to set up a conservation and restoration concept, it is necessary to know about the environmental conditions to which the stained glass windows are exposed. For this purpose very corrosion sensitive model glasses (so called glass sensors were developed which have a similar chemical composition as historic stained glasses. They exhibit the same corrosion reactions but react much faster, and are now widely used to estimate corrosive stresses on stained glass windows to give basic information about the corrosive impacts which work on the historic glasses. In this paper principle corrosion mechanisms of stained glass windows and their enhancing factors are discussed. For the evaluation of the environmental impact, the application of glass sensors is demonstrated.

    Las vidrieras coloreadas pertenecen al legado cultural más importante de Europa. En las últimas décadas se ha producido en ellas un desastroso deterioro. Las maravillosas vidrieras coloreadas y sus policromías est

  18. Rich Ground State Chemical Ordering in Nanoparticles: Exact Solution of a Model for Ag-Au Clusters

    DEFF Research Database (Denmark)

    Larsen, Peter Mahler; Jacobsen, Karsten Wedel; Schiøtz, Jakob

    2018-01-01

    We show that nanoparticles can have very rich ground state chemical order. This is illustrated by determining the chemical ordering of Ag-Au 309-atom Mackay icosahedral nanoparticles. The energy of the nanoparticles is described using a cluster expansion model, and a Mixed Integer Programming (MIP......) approach is used to find the exact ground state configurations for all stoichiometries. The chemical ordering varies widely between the different stoichiometries, and display a rich zoo of structures with non-trivial ordering....

  19. Comparison of the solution and crystal structures of staphylococcal nuclease with 13C and 15N chemical shifts used as structural fingerprints

    International Nuclear Information System (INIS)

    Cole, H.B.R.; Sparks, S.W.; Torchia, D.A.

    1988-01-01

    The authors report high-resolution 13 C and 15 N NMR spectra of crystalline staphylococcal nuclease (Nase) complexed to thymidine 3',5'-diphosphate and Ca 2+ . High sensitivity and resolution are obtained by applying solid-state NMR techniques-high power proton decoupling and cross-polarization magic angle sample spinning (CPMASS)-to protein samples that have been efficiently synthesized and labeled by an overproducing strain of Escherichia coli. A comparison of CPMASS and solution spectra of Nase labeled with either [methyl- 13 C]methionine or [ 15 ]valine shows that the chemical shifts in the crystalline and solution states are virtually identical. This result is strong evidence that the protein conformations in the solution and crystalline states are nearly the same. Because of the close correspondence of the crystal and solution chemical shifts, sequential assignments obtained in solution apply to the crystal spectra. It should therefore be possible to study the molecular structure and dynamics of many sequentially assigned atomic sites in Nase crystals. Similar experiments are applicable to the growing number of proteins that can be obtained from efficient expression systems

  20. Determination of Hydraulic and Transport Parameters of Organic Chemical and Inorganic Anions Solutes for Unfractured Cores of Berea Sandstone Using a Hydraulic Coreholder

    Science.gov (United States)

    Blanford, W. J.; Neil, L.

    2017-12-01

    To better evaluate the potential for toxic organic chemicals to migrate upward through the rock strata from hydraulic fracturing zones and into groundwater resources, a series of miscible displacement solute transport studies of cores of Berea Sandstone have been conducted using hydrostatic core holder. These tests involved passing aqueous solutions with natural background level of salts using a high pressure LC pump through 2 in wide by 3 in long unfractured cores held within the holder. Relative solute transport of 100 to 500ml pulses of target solutes including a series of chlorinated solvents and methylated benzenes was measured through in-line UV and fluorescence detectors and manual sampling and analysis with GCMS. The results found these sandstones to result in smooth ideal shaped breakthrough curves. Analysis with 1D transport models (CXTFIT) of the results found strong correlation with chemical parameters (diffusion coefficients, aqueous solubility, and octanol-water partitioning coefficients) showing that these parameter and QSPR relationships can be used to make accurate predictions for such a system. In addition to the results of the studies, lessons learned from this novel use of a coreholder for evaluation of porosity, water-saturated permeability, and solute transport of these sandstones (K = 1.5cm/day) and far less permeable sandstones samples (K = 0.15 cm/yr) from a hydraulic fracturing site in central Pennsylvania will be presented.

  1. Chemical state analysis of iron(III) compounds precipitated homogeneously from solutions containing urea by means of Moessbauer spectrometry and x-ray diffractometry

    International Nuclear Information System (INIS)

    Ujihira, Yusuke; Ohyabu, Matashige; Murakami, Tetsuro; Horie, Tsuyoshi.

    1978-01-01

    Chemical states of iron(III) compounds, precipitated homogeneously by heating the iron(III) salt solution at 363 K in the presence of urea, was studied by means of Moessbauer spectrometry and X-ray diffractometry. The pH-time relation of urea hydrolysis revealed that the precipitation process from homogeneous solution is identical to the hydrolysis of iron(III) ion at pH around 2 under the homogeneous supply of OH - ion, which is generated by hydrolysis of urea. Accordingly, iron(III) oxide hydroxide or similar compounds to the hydrolysis products of iron(III) ion was precipitated by the precipitation from homogeneous solution methods. Akaganeite (β-FeOOH) was crystallized from 0.1 M iron(III) chloride solution. Goethite(α-FeOOH) and hematite(α-Fe 2 O 3 ) was precipitated from 0.1 M iron(III) nitrate solution, vigorous liberation of OH - ion favoring the crystallization of hematite. The addition of chloride ion to the solution resulted in the formation of akaganeite. Basic salt of iron sulfate[NH 4 Fe 3 (OH) 6 (SO 4 ) 2 ] and goethite were formed from 0.1 M iron(III) sulfate solution, the former being obtained in the more moderate condition of the urea hydrolysis ( 363 K). (author)

  2. Adsorption of nitrate from aqueous solution by magnetic amine-crosslinked biopolymer based corn stalk and its chemical regeneration property

    Energy Technology Data Exchange (ETDEWEB)

    Song, Wen [Key Laboratory of Water Pollution Control and Recycling (Shandong), School of Environmental Science and Engineering, Shandong University, Jinan 250100 (China); Gao, Baoyu, E-mail: bygao@sdu.edu.cn [Key Laboratory of Water Pollution Control and Recycling (Shandong), School of Environmental Science and Engineering, Shandong University, Jinan 250100 (China); Xu, Xing; Wang, Fang; Xue, Nan; Sun, Shenglei [Key Laboratory of Water Pollution Control and Recycling (Shandong), School of Environmental Science and Engineering, Shandong University, Jinan 250100 (China); Song, Wuchang; Jia, Ruibao [Jinan Water and Wastewater Monitoring Center, 250033 Jinan (China)

    2016-03-05

    Graphical abstract: Scheme of mechanism for HCl and NaCl regeneration of MAB-CS. - Highlights: • Magnetic amine-crosslinked bio-adsorbent was prepared for nitrate uptake. • The characters of adsorbent were determined by VSM, TGA, XRD, SEM, TEM, FT-IR and XPS. • This novel bio-adsorbent could achieve rapid separation from effluents. • Chemical regeneration of the saturated magnetic bio-adsorbent was conducted. • The adsorption followed the pseudo second order model and Langmuir model. - Abstract: A novel adsorbent of magnetic amine-crosslinked biopolymer based corn stalk (MAB-CS) was synthesized and used for nitrate removal from aqueous solution. The characters and adsorption mechanisms of this bio-adsorbent were determined by using VSM, TGA, XRD, SEM, TEM, FT-IR and XPS, respectively. The results revealed that the saturated magnetization of MAB-CS reached 6.25 emu/g. Meanwhile, the studies of various factors indicated that this novel magnetic bio-adsorbent performed well over a considerable wide pH range of 6.0∼9.0, and the presence of PO{sub 4}{sup 3−} and SO{sub 4}{sup 2−} would markedly decrease the nitrate removal efficiency. Furthermore, the nitrate adsorption by MAB-CS perfectly fitted the Langmuir isotherm model (R{sup 2} = 0.997–0.999) and pseudo second order kinetic model (R{sup 2} = 0.953–0.995). The calculated nitrate adsorption capacity of MAB-CS was 102.04 mg/g at 318 K by Langmuir model, and thermodynamic study showed that nitrate adsorption is an spontaneous endothermic process. The regeneration experiments indicated its merit of regeneration and stability with the recovery efficient of 118∼147%. By integrating the experimental results, it was found that the removal of nitrate was mainly via electrostatic attraction and ion exchange. And this novel bio-adsorbent prepared in this work could achieve effective removal of nitrate and rapid separation from effluents simultaneously.

  3. Ferroelectrics onto silicon prepared by chemical solution deposition methods: from the thin film to the self-assembled systems

    Directory of Open Access Journals (Sweden)

    Calzada, M. L.

    2006-06-01

    Full Text Available The work of the authors during the last years on ferroelectric thin and ultra-thin films deposited by Chemical Solution Deposition (CSD onto silicon based substrates is reviewed in this paper. Ferroelectric layers integrated with silicon substrates have potential use in the new micro/nanoelectronic devices. Two hot issues are here considered: 1 the use of low processing temperatures of the ferroelectric film, with the objective of not producing any damage on the different elements of the device heterostructure, and 2 the downscaling of the ferroelectric material with the aim of achieving the high densities of integration required in the next generation of nanoelectronic devices. The UV-assisted Rapid Thermal Processing has successfully been used in our laboratory for the fabrication of ferroelectric films at low temperatures. Preliminary results on the CSD preparation of nanosized ferroelectric structures are shown.

    Este artículo revisa el trabajo realizado por los autores durante los últimos años sobre lámina delgada y ultra-delgada ferroeléctrica preparada mediante el depósito químico de disoluciones (CSD sobre substratos de silicio. Las películas ferroeléctricas integradas con silicio tienen potenciales usos en los nuevos dispositivos micro/nanoelectrónicos. Dos aspectos claves son aquí considerados: 1 el uso de bajas temperaturas de procesado de la lámina ferroeléctrica, con el fin de no dañar los diferentes elementos que forman la heteroestructura del dispositivo y 2 la disminución de tamaño del material ferroeléctrico con el fin de conseguir las altas densidades de integración requeridas en la próxima generación de dispositivos nanoelectróncos. Los procesos térmicos rápidos asistidos con irradiación UV se están usando en nuestro laboratorio para conseguir la fabricación del material ferroeléctrico a temperaturas bajas compatibles con la tecnología del silicio. Se muestran resultados preliminares sobre

  4. chemical studies on the reactivity of some organic extractants for extraction and separation of certain elements from aqueous solutions

    International Nuclear Information System (INIS)

    Aly, M.M.I.

    2010-01-01

    Lanthanide elements such as lanthanum and neodymium are important elements in photo-electronic and metallurgical industries as well as in nuclear technology. The main constituents of the spent nuclear fuel are actinides like uranium, thorium and various fission products including lanthanides. The co-ordination compounds of the trivalent lanthanum and neodymium continues to be an active research area, which includes the specific spectroscopic and magnetic properties of rare earth ions and their applications as super molecular device, contrast-enhancing agents in magnetic resonance imaging, optical signal amplifiers and electroluminescent (EL) devices. Hence, the separation and purification of these elements is of great concern. Solvent extraction technique is employed to separate and purify rare earth elements in an industrial scale, but the separation of lanthanum and neodymium is a difficult task, as lanthanide ions exhibit similar chemical and physical properties. They have generally common and stable +3 oxidation state that requires synthesis of certain extractants which are able to extract them from different aqueous solutions. During the last twenty years, different publications have pointed out the remarkable properties of alkyl amide in the field of separation chemistry. These extractants are able to form stable co-ordination compounds with different metallic ions. In this concern, this thesis deals with the synthesis of different amide extractants namely N, N diethylacetoamide (DEAA), N, N Teteraphenyl malonamide (TPMA), N, N diphenylbenzamide (DPBA), N, N' diphenylacetoamide (DPAA), and N, N' Teteraethyl malonamide (TEMA), which were synthesized, characterized and compared with Aliquat-336 in kerosene for extraction and separation of La (III) and Nd (III). The effect of the different parameters affecting the extraction of these metals from aqueous nitric acid medium in the different systems has been studied in terms of shaking time, nitric acid, hydrogen

  5. Laser Treatment of Port Wine Stains

    Science.gov (United States)

    Majaron, Boris; Nelson, J. Stuart

    Port wine stain (PWS), also called nevus flammeus, is a congenital, cutaneous vascular malformation involving post-capillary venules which produce a light pink to red to dark-red-violet discoloration of human skin [1]. PWS occurs in an estimated 3 children per 1000 live births, affecting males and females and all racial groups equally [2]. There appears to be no hereditary predilection for PWS within families. There are no known risk factors or ways to prevent PWS.

  6. Physico-Chemical Study of the Separation of Calcium Isotopes by Chemical Exchange Between Amalgam and Salt Solutions; Etude physico-chimique de la separation des isotopes du calcium par echange chimique entre amalgame et solution saline

    Energy Technology Data Exchange (ETDEWEB)

    Duie, P; Dirian, G [Commissariat a l' Energie Atomique. Centre d' Etudes Nucleaires de Saclay, 91 - Gif-sur-Yvette (France)

    1962-07-01

    In a preliminary study of the isotopic exchange between Ca amalgam and aqueous or organic solutions of Ca salts, the main parameters governing the feasibility of a separation process based on these systems such as separation factor, exchange kinetics, rate of decomposition of the amalgam were investigated. The separation factor between {sup 40}Ca and {sup 46}Ca was found to be of the order of 1.02. The rate of the exchange reaction is rather low for aqueous solutions, extremely low for organic solutions. The amalgam seems not to be attacked by dimethyl-formamide solutions; but it is rapidly decomposed by aqueous solutions of Ca halides. This decomposition is slow in the case of aqueous solutions of calcium formate and still slower for Ca(OH){sub 2}; however, except in particular conditions, the observed rate is often much higher, owing to interfering reactions between amalgam and water vapor contained in H{sub 2} bubbles. (authors) [French] On a fait une etude preliminaire, pour des systemes amalgame de calcium - solution aqueuse ou organique de sels de calcium, des principaux parametres pouvant intervenir dans l'application d'un procede d'echange a l'enrichissement isotopique du calcium: facteur de separation, cinetique de l'echange, cinetique de la decomposition de l'amalgame. Les facteurs de separation {sup 40}Ca-{sup 46}Ca sont de l'ordre de 1,02. L'echange est assez lent pour les solutions aqueuses, extremement lent pour les solutions organiques. La decomposition de l'amalgame est pratiquement inexistante avec les solutions dans le dimethyl- formamide, appreciable pour les solutions alcooliques, rapide pour les solutions aqueuses d'halogenures; elle est normalement lente pour les solutions aqueuses de formiate et surtout de chaux, mais la decomposition est en general acceleree par une reaction parasite entre l'amalgame et l'eau a l'etat vapeur, reaction que l'on n'evite dans des conditions tres particulieres. (auteurs)

  7. Stain Deconvolution Using Statistical Analysis of Multi-Resolution Stain Colour Representation.

    Directory of Open Access Journals (Sweden)

    Najah Alsubaie

    Full Text Available Stain colour estimation is a prominent factor of the analysis pipeline in most of histology image processing algorithms. Providing a reliable and efficient stain colour deconvolution approach is fundamental for robust algorithm. In this paper, we propose a novel method for stain colour deconvolution of histology images. This approach statistically analyses the multi-resolutional representation of the image to separate the independent observations out of the correlated ones. We then estimate the stain mixing matrix using filtered uncorrelated data. We conducted an extensive set of experiments to compare the proposed method to the recent state of the art methods and demonstrate the robustness of this approach using three different datasets of scanned slides, prepared in different labs using different scanners.

  8. Investigation of black soot staining in houses

    Energy Technology Data Exchange (ETDEWEB)

    Fugler, D. [Canada Mortgage and Housing Corp., Ottawa, ON (Canada)

    2000-07-01

    Air quality investigators are frequently called upon to determine the origin of streaking, staining or soot marks in both new and old homes. Those marks display common characteristics: black marks along baseboards at interior or exterior walls, behind furniture and at doorways; black smudges on window frames and plastic cabinets; and even shadowing of studs on exterior wall drywall in a few cases. In most instances, carbon soot from a combustion source is the culprit. The combustion sources include furnaces, water heaters, fireplaces, gas dryers, gas ranges, smoking, vehicle exhaust and candle burning. Scepticism about candle soot is prevalent among callers. As a result, a study was initiated in homes where occupants burn candles regularly to investigate soot problems. Samples were collected from five homes, and included stained carpets, filters, and swab samples of black dust or soot. All the houses selected for the study had been built within a three-year period. Some samples of candles commonly burned in those homes were burnt in a laboratory. Air quality audits had been performed in the homes and had revealed other potential pollutant sources. Best practices for cost-effective clean up and control of soot were researched in industry information. The tests conducted in the laboratory found materials consistent with candle soot or residue during microscopic investigations, but no link was established with the stained material obtained from the homes. A few tips for homeowners were included concerning candle burning, and tips for builders were also offered. 1 tab.

  9. Development of One Meter Long Double-Sided CeO2 Buffered Ni-5at.%W Templates by Reel-to-Reel Chemical Solution Deposition Route

    DEFF Research Database (Denmark)

    Yue, Zhao; Konstantopoulou, K.; Wulff, Anders Christian

    2013-01-01

    High performance long-length coated conductors fabricated using various techniques have attracted a lot of interest recently. In this work, a reel-to-reel design for depositing double-sided coatings on long-length flexible metallic tapes via a chemical solution method is proposed and realized...... layer are 7.2◦ and 5.8◦ with standard deviation of 0.26◦ and 0.34◦, respectively, being indicative of the high quality epitaxial growth of the films prepared in the continuous manner. An all chemical solution derived YBCOLow−TFA/Ce0.9La0.1O2/Gd2Zr2O7/CeO2 structure is obtained on a short sample...

  10. REACT-Mod: a mathematical model for transient calculation of chemical reactions with U-Pu-Np-Tc in the aqueous nitric acid solution

    International Nuclear Information System (INIS)

    Tachimori, Shoichi; Kitamura, Tatsuaki.

    1996-10-01

    A computer code REACT-Mod which simulates various chemical reactions in an aqueous nitric acid solution involving uranium, plutonium, neptunium, technetium etc. e.g., redox, radiolytic and disproportionation reactions of 68, was developed based on the kinetics model. The numerical solution method adopted in the code are two, a kinetics model totally based on the rate law of which differential equations are solved by the modified Porsing method, and a two-step model based on both the rate law and equilibrium law. Only the former treats 27 radiolytic reactions. The latter is beneficially used to have a quick and approximate result by economical computation. The present report aims not only to explain the concept, chemical reactions treated and characteristics of the model but also to provide details of the program for users of the REACT-Mod code. (author)

  11. Generation of InN nanocrystals in organic solution through laser ablation of high pressure chemical vapor deposition-grown InN thin film

    International Nuclear Information System (INIS)

    Alkis, Sabri; Alevli, Mustafa; Burzhuev, Salamat; Vural, Hüseyin Avni; Okyay, Ali Kemal; Ortaç, Bülend

    2012-01-01

    We report the synthesis of colloidal InN nanocrystals (InN-NCs) in organic solution through nanosecond pulsed laser ablation of high pressure chemical vapor deposition-grown InN thin film on GaN/sapphire template substrate. The size, the structural, the optical, and the chemical characteristics of InN-NCs demonstrate that the colloidal InN crystalline nanostructures in ethanol are synthesized with spherical shape within 5.9–25.3, 5.45–34.8, 3.24–36 nm particle-size distributions, increasing the pulse energy value. The colloidal InN-NCs solutions present strong absorption edge tailoring from NIR region to UV region.

  12. Controlled synthesis of high-quality nickel sulfide chain-like tubes and echinus-like nanostructures by a solution chemical route

    International Nuclear Information System (INIS)

    Zhang Yahui; Guo Lin; He Lin; Liu, Kang; Chen Chinping; Zhang Qi; Wu Ziyu

    2007-01-01

    Chain-like NiS tubes and echinus-like nickel sulfide (Ni 3 S 2 ) nanostructures were synthesized successfully by a solution chemical route. The growth models of these two materials and the most possible mutation process between these two different morphologies are discussed. The temperature and field dependent magnetizations, M(T) and M(H), show that both the samples have a very weak ferromagnetism and exhibit a strong paramagnetic response in a high applied field

  13. Liquid dish washing soap: An excellent substitute for xylene and alcohol in hematoxylin and eosin staining procedure

    Directory of Open Access Journals (Sweden)

    Surekha Ramulu

    2012-01-01

    Full Text Available Aims: Liquid dish washing solution (DWS was used as a substitute for xylene to dewax tissue sections during hematoxylin and eosin (H and E staining. The aim was to test and compare the hypothesis that xylene-ethanol free (XEF sections deparaffinized with diluted DWS are better than or at par with the conventional H and E sections. Materials and Methods: Fifty paraffin-embedded tissue blocks was included. One section was stained with conventional HandE (group A and the other with XEF HandE (group B staining method. Slides were scored for parameters: nuclear, cytoplasmic, clarity, uniformity, and crispness of staining. Z test was used for statistical analysis. For accuracy of diagnosis, sensitivity, specificity, positive predictive value, and negative predictive value were tested. Results: Adequate nuclear staining was noted in 94% in group A and 96% in group B, -adequate cytoplasmic staining in 92% in group A and 86% in group B, clarity in 94% of group A and 96% of group B sections, uniform staining in 92% of group A and 80% of group B sections, crisp stain in 96% of group A and 88% of group B sections, and 94% of group A sections stained adequately for diagnosis as compared with 90% in group B sections. Conclusion: Liquid DWS can be used as an alternative and effective substitute to xylene and ethanol in routine HandE staining procedure.

  14. On the performance of quantum chemical methods to predict solvatochromic effects. The case of acrolein in aqueous solution

    DEFF Research Database (Denmark)

    Aidas, Kestutis; Møgelhøj, Andreas; Nilsson, Elna Johanna Kristina

    2008-01-01

    The performance of the Hartree–Fock method and the three density functionals B3LYP, PBE0, and CAM-B3LYP is compared to results based on the coupled cluster singles and doubles model in predictions of the solvatochromic effects on the vertical n¿* and ¿* electronic excitation energies of acrolein...... of acrolein in vapor phase and aqueous solution. The gas-to-aqueous solution shift of the n¿* excitation energy is well reproduced by using all density functional methods considered. However, the B3LYP and PBE0 functionals completely fail to describe the ¿* electronic transition in solution, whereas...... the recent CAM-B3LYP functional performs well also in this case. The ¿* excitation energy of acrolein in water solution is found to be very dependent on intermolecular induction and nonelectrostatic interactions. The computed excitation energies of acrolein in vacuum and solution compare well to experimental...

  15. Controlling the Release of Indomethacin from Glass Solutions Layered with a Rate Controlling Membrane Using Fluid-Bed Processing. Part 1: Surface and Cross-Sectional Chemical Analysis.

    Science.gov (United States)

    Dereymaker, Aswin; Scurr, David J; Steer, Elisabeth D; Roberts, Clive J; Van den Mooter, Guy

    2017-04-03

    Fluid bed coating has been shown to be a suitable manufacturing technique to formulate poorly soluble drugs in glass solutions. Layering inert carriers with a drug-polymer mixture enables these beads to be immediately filled into capsules, thus avoiding additional, potentially destabilizing, downstream processing. In this study, fluid bed coating is proposed for the production of controlled release dosage forms of glass solutions by applying a second, rate controlling membrane on top of the glass solution. Adding a second coating layer adds to the physical and chemical complexity of the drug delivery system, so a thorough understanding of the physical structure and phase behavior of the different coating layers is needed. This study aimed to investigate the surface and cross-sectional characteristics (employing scanning electron microscopy (SEM) and time of flight secondary ion mass spectrometry (ToF-SIMS)) of an indomethacin-polyvinylpyrrolidone (PVP) glass solution, top-coated with a release rate controlling membrane consisting of either ethyl cellulose or Eudragit RL. The implications of the addition of a pore former (PVP) and the coating medium (ethanol or water) were also considered. In addition, polymer miscibility and the phase analysis of the underlying glass solution were investigated. Significant differences in surface and cross-sectional topography of the different rate controlling membranes or the way they are applied (solution vs dispersion) were observed. These observations can be linked to the polymer miscibility differences. The presence of PVP was observed in all rate controlling membranes, even if it is not part of the coating solution. This could be attributed to residual powder presence in the coating chamber. The distribution of PVP among the sample surfaces depends on the concentration and the rate controlling polymer used. Differences can again be linked to polymer miscibility. Finally, it was shown that the underlying glass solution layer

  16. Characterization of Cu–Ni nanostructured alloys obtained by a chemical route. Influence of the complexing agent content in the starting solution

    Energy Technology Data Exchange (ETDEWEB)

    Carreras, Alejo C., E-mail: acarreras@famaf.unc.edu.ar [Instituto de Física Enrique Gaviola (IFEG), Facultad de Matemática, Astronomía y Física, Universidad Nacional de Córdoba—CONICET, Medina Allende s/n, Ciudad Universitaria, 5016 Córdoba (Argentina); Cangiano, María de los A.; Ojeda, Manuel W.; Ruiz, María del C. [Instituto de Investigaciones en Tecnología Qumica (INTEQUI), Facultad de Química, Bioquímica y Farmacia, Universidad Nacional de San Luis—CONICET, Chacabuco y Pedernera, 5700 San Luis (Argentina)

    2015-03-15

    The influence of the amount of complexing agent added to the starting solution on the physicochemical properties of Cu–Ni nanostructured alloys obtained through a chemical route, was studied. For this purpose, three Cu–Ni nanoalloy samples were synthesized by a previously developed procedure, starting from solutions with citric acid to metal molar ratios (C/Me) of 0.73, 1.00 and 1.50. The synthesis technique consisted in preparing a precursor via the citrate-gel method, and carrying out subsequent thermal treatments in controlled atmospheres. Sample characterization was performed by scanning electron microscopy, X-ray microanalysis, X-ray diffraction, transmission electron microscopy, X-ray nanoanalysis and electron diffraction. In the three cases, copper and nickel formed a solid solution with a Cu/Ni atomic ratio close to 50/50, and free of impurities inside the crystal structure. The citric acid content of the starting solution proved to have an important influence on the morphology, size distribution, porosity, and crystallinity of the Cu–Ni alloy microparticles obtained, but a lesser influence on their chemical composition. The molar ratio C/Me = 1.00 resulted in the alloy with the Cu/Ni atomic ratio closest to 50/50. - Highlights: • We synthesize Cu–Ni nanoalloys by a chemical route based on the citrate-gel method. • We study the influence of the complexing agent content of the starting solution. • We characterize the samples by electron microscopy and X-ray techniques. • Citric acid influences the shape, size, porosity and crystallinity of the alloys.

  17. Stain removal and whitening by baking soda dentifrice: A review of literature.

    Science.gov (United States)

    Li, Yiming

    2017-11-01

    Tooth discoloration may be caused by intrinsic or extrinsic stains or a combination of both. There are 2 major approaches to removing the stains, including the chemical mechanism using peroxides for tooth bleaching and the mechanical mechanism using abrasives in prophylactic pastes and dentifrices to remove stains, resulting in a whitening effect. Attempts have also been made to add a low concentration of peroxides to dentifrices to enhance their abrasive cleaning to remove tooth stains. This article provides a review of both in vitro and clinical studies on stain removal and whitening effect of dentifrices containing sodium bicarbonate (baking soda). In recent years, whitening dentifrices have become popular because of little additional effort for use, ease of availability, low cost, and accumulated evidence of clinical efficacy and safety in the literature. Advances in research and technology have led to innovative formulations of dentifrices using baking soda as the sole abrasive or a component of an abrasive system. Baking soda is biologically compatible with acid-buffering capacities, antibacterial at high concentrations, and has a relatively lower abrasivity. The evidence available in the literature indicates that baking soda-based dentifrices are effective and safe for tooth stain removal and consequently whitening. A number of clinical studies have also shown that baking soda-based dentifrices are more effective in stain removal and whitening than some non-baking soda-containing dentifrices with a higher abrasivity. So far, research efforts have mainly focused on stain removal and tooth-whitening efficacy and clinical safety of baking soda dentifrices used with manual toothbrushes, with only a few studies investigating their effects using powered toothbrushes, for which further research is encouraged. As part of a daily oral hygiene practice, baking soda-based dentifrice is a desirable, alternative or additional measure for tooth stain removal and whitening

  18. Weathering effects on materials from historical stained glass windows

    Directory of Open Access Journals (Sweden)

    García-Heras, M.

    2003-06-01

    Full Text Available A selection of materials (stained glasses, lead cames, support elements and putty from historical stained glass windows of different periods (13th-19th centuries have been studied. Optical microscopy, scanning electron microscopy, energy dispersive X-ray spectrometry and X-ray diffraction were used as characterization techniques. Degradation of historical stained glass windows is due to the particular chemical composition oftlie materials used for their production: stained glasses, lead network, metallic support elements and refilling putty. However, the presence of a given chemical composition is not the only factor involved in the degradation process. It is necessary the occurrence of other external factors that contribute to the development and progress of alteration problems in the materials mentioned above. The presence of gaseous pollution in the air produces a negative interaction with the surface of the stained glass windows materials. Firstly, the stained glasses and the grisailles begin a dealkalinisation process and a silica gel layer is formed during the early contact between the glasses and the wet environment. After that, insoluble salt deposits and corrosion crusts are formed as a consequence of a deeper chemical attack which results in a depolymerisation of the glass network. The lead cames and the metallic support elements are also altered by weathering. Such materials are oxidized and both pits and crusts appear on their surfaces. The transport of ions and other substances from the corrosion crusts of the metallic elements gives rise new deposits upon the stained glasses, which could intensify their own degradation processes. The putty experiments a noticeable shrinkage and cracking. Likewise, adverse environmental conditions favour the transport of putty substances towards the other materials of the stained glass window, thereby increasing the crusts thickness and adding elements that contribute to the total alteration of the

  19. Histological staining methods preparatory to laser capture microdissection significantly affect the integrity of the cellular RNA

    Directory of Open Access Journals (Sweden)

    Li Ming-Chung

    2006-04-01

    Full Text Available Abstract Background Gene expression profiling by microarray analysis of cells enriched by laser capture microdissection (LCM faces several technical challenges. Frozen sections yield higher quality RNA than paraffin-imbedded sections, but even with frozen sections, the staining methods used for histological identification of cells of interest could still damage the mRNA in the cells. To study the contribution of staining methods to degradation of results from gene expression profiling of LCM samples, we subjected pellets of the mouse plasma cell tumor cell line TEPC 1165 to direct RNA extraction and to parallel frozen sectioning for LCM and subsequent RNA extraction. We used microarray hybridization analysis to compare gene expression profiles of RNA from cell pellets with gene expression profiles of RNA from frozen sections that had been stained with hematoxylin and eosin (H&E, Nissl Stain (NS, and for immunofluorescence (IF as well as with the plasma cell-revealing methyl green pyronin (MGP stain. All RNAs were amplified with two rounds of T7-based in vitro transcription and analyzed by two-color expression analysis on 10-K cDNA microarrays. Results The MGP-stained samples showed the least introduction of mRNA loss, followed by H&E and immunofluorescence. Nissl staining was significantly more detrimental to gene expression profiles, presumably owing to an aqueous step in which RNA may have been damaged by endogenous or exogenous RNAases. Conclusion RNA damage can occur during the staining steps preparatory to laser capture microdissection, with the consequence of loss of representation of certain genes in microarray hybridization analysis. Inclusion of RNAase inhibitor in aqueous staining solutions appears to be important in protecting RNA from loss of gene transcripts.

  20. Histological staining methods preparatory to laser capture microdissection significantly affect the integrity of the cellular RNA.

    Science.gov (United States)

    Wang, Hongyang; Owens, James D; Shih, Joanna H; Li, Ming-Chung; Bonner, Robert F; Mushinski, J Frederic

    2006-04-27

    Gene expression profiling by microarray analysis of cells enriched by laser capture microdissection (LCM) faces several technical challenges. Frozen sections yield higher quality RNA than paraffin-imbedded sections, but even with frozen sections, the staining methods used for histological identification of cells of interest could still damage the mRNA in the cells. To study the contribution of staining methods to degradation of results from gene expression profiling of LCM samples, we subjected pellets of the mouse plasma cell tumor cell line TEPC 1165 to direct RNA extraction and to parallel frozen sectioning for LCM and subsequent RNA extraction. We used microarray hybridization analysis to compare gene expression profiles of RNA from cell pellets with gene expression profiles of RNA from frozen sections that had been stained with hematoxylin and eosin (H&E), Nissl Stain (NS), and for immunofluorescence (IF) as well as with the plasma cell-revealing methyl green pyronin (MGP) stain. All RNAs were amplified with two rounds of T7-based in vitro transcription and analyzed by two-color expression analysis on 10-K cDNA microarrays. The MGP-stained samples showed the least introduction of mRNA loss, followed by H&E and immunofluorescence. Nissl staining was significantly more detrimental to gene expression profiles, presumably owing to an aqueous step in which RNA may have been damaged by endogenous or exogenous RNAases. RNA damage can occur during the staining steps preparatory to laser capture microdissection, with the consequence of loss of representation of certain genes in microarray hybridization analysis. Inclusion of RNAase inhibitor in aqueous staining solutions appears to be important in protecting RNA from loss of gene transcripts.

  1. Investigation of the main chemical properties of water-magnesium chloride solutions. Application to the understanding of stress corrosion phenomena in 17.12 Mo stainless steel

    International Nuclear Information System (INIS)

    Hasni, Abdellatif

    1988-01-01

    This research thesis reports the investigation of the main chemical properties of concentrated aqueous solutions of MgCl 2 and of their influence of stress corrosion of 17Cr-12Ni-2Mo stainless steel. It shows that the most important chemical properties are the equilibrium pH and the acidity range of MgCl 2 aqueous solutions, and that they strongly depend on solution temperature and concentration. The medium pH is governed by the increased acidity of water in presence of Mg ++ ions, while the acidity range is determined by a hydrolysis reaction of these ions which results in a precipitation of magnesium hydroxyl-chlorides. The investigation of stress corrosion behaviour of the steel in MgCl 2 solutions with varying temperature and concentration shows that this behaviour comes down to a prevailing pH effect which results from the variation of these both parameters, with a not negligible but less important effect of temperature. A study of cracking surfaces indicates that it is possible to pass from a transgranular to an intergranular mode by a variation of either media aggressiveness (pH, temperature, voltage) or strain rate. These results are explained by a concept of kinetic factor which limits stress corrosion [fr

  2. Oriented growth of Sr n+1Ti n O3n+1 Ruddlesden-Popper phases in chemical solution deposited thin films

    International Nuclear Information System (INIS)

    Gutmann, Emanuel; Levin, Alexandr A.; Reibold, Marianne; Mueller, Jan; Paufler, Peter; Meyer, Dirk C.

    2006-01-01

    Oriented thin films of perovskite-related Sr n +1 Ti n O 3 n +1 Ruddlesden-Popper phases (n=1, 2, 3) were grown on (001) single-crystalline SrTiO 3 substrates. Preparation of the films was carried out by wet chemical deposition from metalorganic Sr-Ti solutions (rich in Sr) and subsequent conversion into the crystalline state by thermal treatment in air atmosphere at a maximum temperature of 700 deg. C. Solutions were prepared by a modified Pechini method. The films were investigated by wide-angle X-ray scattering and high-resolution transmission electron microscopy. The phase content of powders prepared from the dried solutions and annealed under similar conditions differed from that present in the films, i.e. only polycrystalline SrTiO 3 was detected together with oxides of Ti and Sr. - Graphical abstract: Cross-sectional image of an oriented chemical solution deposited thin film obtained by high-resolution transmission electron microscopy. Periodical spacings corresponding to SrTiO 3 substrate (right) and Sr 2 TiO 4 Ruddlesden-Popper phase (n=1) film region (left) are marked

  3. Structural characterization of chemical warfare agent degradation products in decontamination solutions with proton band-selective (1)H-(31)P NMR spectroscopy.

    Science.gov (United States)

    Koskela, Harri; Hakala, Ullastiina; Vanninen, Paula

    2010-06-15

    Decontamination solutions, which are usually composed of strong alkaline chemicals, are used for efficient detoxification of chemical warfare agents (CWAs). The analysis of CWA degradation products directly in decontamination solutions is challenging due to the nature of the matrix. Furthermore, occasionally an unforeseen degradation pathway can result in degradation products which could be eluded to in standard analyses. Here, we present the results of the application of proton band-selective (1)H-(31)P NMR spectroscopy, i.e., band-selective 1D (1)H-(31)P heteronuclear single quantum coherence (HSQC) and band-selective 2D (1)H-(31)P HSQC-total correlation spectroscopy (TOCSY), for ester side chain characterization of organophosphorus nerve agent degradation products in decontamination solutions. The viability of the approach is demonstrated with a test mixture of typical degradation products of nerve agents sarin, soman, and VX. The proton band-selective (1)H-(31)P NMR spectroscopy is also applied in characterization of unusual degradation products of VX in GDS 2000 solution.

  4. Phase Evolution of YBa2Cu3O7-x films by all-chemical solution deposition route for coated conductors

    DEFF Research Database (Denmark)

    Yue, Zhao; Tang, Xiao; Wu, Wei

    2014-01-01

    In order to understand the all-chemical-solution-deposition (CSD) processes for manufacturing coated conductors, we investigated the phase evolution of YBa2Cu3O7 (YBCO) films deposited by a low-fluorine metal-organic solution deposition (LF-MOD) method on CSD derived Ce0.9La0.1O2/Gd2Zr2O7/Ni......W. It is shown that the phase transition from the pyrolyzed film to fully converted YBCO film in the LF-MOD process is similar to that in typical trifluoroacetates-metal organic deposition (TFA-MOD) processes even though the amount of TFA in the solution is reduced by almost one half compared with typical TFA...

  5. Efficient Computational Research Protocol to Survey Free Energy Surface for Solution Chemical Reaction in the QM/MM Framework: The FEG-ER Methodology and Its Application to Isomerization Reaction of Glycine in Aqueous Solution.

    Science.gov (United States)

    Takenaka, Norio; Kitamura, Yukichi; Nagaoka, Masataka

    2016-03-03

    In solution chemical reaction, we often need to consider a multidimensional free energy (FE) surface (FES) which is analogous to a Born-Oppenheimer potential energy surface. To survey the FES, an efficient computational research protocol is proposed within the QM/MM framework; (i) we first obtain some stable states (or transition states) involved by optimizing their structures on the FES, in a stepwise fashion, finally using the free energy gradient (FEG) method, and then (ii) we directly obtain the FE differences among any arbitrary states on the FES, efficiently by employing the QM/MM method with energy representation (ER), i.e., the QM/MM-ER method. To validate the calculation accuracy and efficiency, we applied the above FEG-ER methodology to a typical isomerization reaction of glycine in aqueous solution, and reproduced quite satisfactorily the experimental value of the reaction FE. Further, it was found that the structural relaxation of the solute in the QM/MM force field is not negligible to estimate correctly the FES. We believe that the present research protocol should become prevailing as one computational strategy and will play promising and important roles in solution chemistry toward solution reaction ergodography.

  6. The comparison of pyrosequencing molecular Gram stain, culture, and conventional Gram stain for diagnosing orthopaedic infections.

    Science.gov (United States)

    Kobayashi, Naomi; Bauer, Thomas W; Tuohy, Marion J; Lieberman, Isador H; Krebs, Viktor; Togawa, Daisuke; Fujishiro, Takaaki; Procop, Gary W

    2006-08-01

    We have developed a combined real-time PCR and pyrosequencing assay that successfully differentiated the vast majority of gram-positive and gram-negative bacteria when bacterial isolates were tested. The purpose of this study was to evaluate this assay on clinical specimens obtained from orthopedic surgeries, and to prospectively compare the results of "molecular Gram stain" with culture and conventional direct Gram stain. Forty-five surgical specimens were obtained from patients who underwent orthopedic surgery procedures. The DNA was extracted and a set of broad-range PCR primers that targeted a part of the 16S rDNA gene was used for pan-bacterial PCR. The amplicons were submitted for pyrosequencing and the resulting molecular Gram stain characteristics were recorded. Culture and direct Gram staining were performed using standard methods for all cases. Surgical specimens were reviewed histologically for all cases that had a discrepancy between culture and molecular results. There was an 86.7% (39/45) agreement between the traditional and molecular methods. In 12/14 (85.7%) culture-proven cases of bacterial infection, molecular Gram stain characteristics were in agreement with the culture results, while the conventional Gram stain result was in agreement only for five cases (35.7%). In the 31 culture negative cases, 27 cases were also PCR negative, whereas 4 were PCR positive. Three of these were characterized as gram negative and one as gram positive by this molecular method. Molecular determination of the Gram stain characteristics of bacteria that cause orthopedic infections may be achieved, in most instances, by this method. Further studies are necessary to understand the clinical importance of PCR-positive/culture-negative results.

  7. Catalytic destruction of perchlorate in ferric chloride and hydrochloric acid solution with control of temperature, pressure and chemical reagents

    Science.gov (United States)

    Gu, Baohua; Cole, David R.; Brown, Gilbert M.

    2004-10-05

    A method is described to decompose perchlorate in a FeCl.sub.3 /HCl aqueous solution such as would be used to regenerate an anion exchange resin used to remove perchlorate. The solution is mixed with a reducing agent, preferably an organic alcohol and/or ferrous chloride, and can be heated to accelerate the decomposition of perchlorate. Lower temperatures may be employed if a catalyst is added.

  8. Ca{sub 2−x}Li{sub 2x}GeO{sub 4} solid solutions. Chemical composition range and flux crystal growth

    Energy Technology Data Exchange (ETDEWEB)

    Ivanov, V.A. [N.I. Lobachevsky State University of Nizhni Novgorod, Nizhni Novgorod, 603950 (Russian Federation); Marychev, M.O., E-mail: marychev@yandex.ru [N.I. Lobachevsky State University of Nizhni Novgorod, Nizhni Novgorod, 603950 (Russian Federation); Andreev, P.V.; Lykov, V.A.; Faddeev, M.A. [N.I. Lobachevsky State University of Nizhni Novgorod, Nizhni Novgorod, 603950 (Russian Federation); Koseva, I. [Bulgarian Academy of Science, Institute of General and Inorganic Chemistry, BU-1113 Sofia (Bulgaria); Nikolov, V. [N.I. Lobachevsky State University of Nizhni Novgorod, Nizhni Novgorod, 603950 (Russian Federation)

    2015-11-01

    A series of Ca{sub 2−x}Li{sub 2x}GeO{sub 4} specimens with 0 < 2x < 2, were synthesized by the classical solid state method. X-ray analysis revealed that for 0 < 2x < 0.6 only Ca{sub 2−x}Li{sub 2x}GeO{sub 4} solid solutions of Ca{sub 2}GeO{sub 4} structure crystallized. The cell parameters of these solid solutions linearly decreased upon increasing the lithium concentration, which means that the solutions are in accordance with the Vegard's law. For 2x > 0.6 the specimens contained two phases: (i) Ca{sub 2−x}Li{sub 2x}GeO{sub 4} solid solutions with maximum lithium concentration approximately equal to that for 2x = 0.6 and minimum values of the cell parameters and (ii) Li{sub 2}CaGeO{sub 4} phase. Li{sub 2}O·MoO{sub 3}–Ca{sub 2}GeO{sub 4} high-temperature solutions were used to grow Ca{sub 2−x}Li{sub 2x}GeO{sub 4} solid solutions and Li{sub 2}CaGeO{sub 4} single crystals by the high temperature solution (flux) method. Li{sub 2}CaGeO{sub 4} crystals were grown in the concentration range 8–26 wt. % Ca{sub 2}GeO{sub 4} in the temperature range 830–980 °C. Crystals with chemical compositions of the Ca{sub 2−x}Li{sub 2x}GeO{sub 4} solid solutions with different Li concentrations were grown in the concentration range 26–40 wt. % Ca{sub 2}GeO{sub 4} in the temperature range 980–1090 °C. - Highlights: • Ca{sub 2−x}Li{sub 2x}GeO{sub 4} solid solutions are established for the first time. • The Li concentration range into the solutions is between 0 and 0.6. • The solid solutions are in accordance to Vegard's law. • Suitable solutions are found out for Ca{sub 2−x}Li{sub 2x}GeO{sub 4} and Li{sub 2}CaGeO{sub 4} crystal growth.

  9. Two-dimensional analytical solutions for chemical transport in aquifers. Part 1. Simplified solutions for sources with constant concentration. Part 2. Exact solutions for sources with constant flux rate

    International Nuclear Information System (INIS)

    Shan, C.; Javandel, I.

    1996-05-01

    Analytical solutions are developed for modeling solute transport in a vertical section of a homogeneous aquifer. Part 1 of the series presents a simplified analytical solution for cases in which a constant-concentration source is located at the top (or the bottom) of the aquifer. The following transport mechanisms have been considered: advection (in the horizontal direction), transverse dispersion (in the vertical direction), adsorption, and biodegradation. In the simplified solution, however, longitudinal dispersion is assumed to be relatively insignificant with respect to advection, and has been neglected. Example calculations are given to show the movement of the contamination front, the development of concentration profiles, the mass transfer rate, and an application to determine the vertical dispersivity. The analytical solution developed in this study can be a useful tool in designing an appropriate monitoring system and an effective groundwater remediation method

  10. Selenium Incorporated Cationic Organochalcogen: Live Cell Compatible and Highly Photostable Molecular Stain for Imaging and Localization of Intracellular DNA.

    Science.gov (United States)

    Gaur, Pankaj; Kumar, Ajay; Dey, Gourab; Kumar, Rajendra; Bhattacharyya, Shalmoli; Ghosh, Subrata

    2016-05-04

    Successful integration of selenium unit into a newly designed cationic chemical architecture led to the development of a highly photostable molecular maker PA5 to be used in fluorescence microscopy as cellular nucleus staining agent for longer duration imaging under continuous laser illumination. Adaptation of a targeted single-atom modification strategy led to the development of a series of proficient DNA light-up probes (PA1-PA5). Further, their comparative photophysical studies in the presence of DNA revealed the potential of electron rich heteroatoms of chalcogen family in improving binding efficiency and specificity of molecular probes toward DNA. The findings of cell studies confirmed the outstanding cell compatibility of probe PA5 in terms of cell permeability, biostability, and extremely low cytotoxicity. Moreover, the photostability experiment employing continuous laser illumination in solution phase as well as in cell assay (both fixed and live cells) revealed the admirable photobleaching resistance of PA5. Finally, while investigating the phototoxicity of PA5, the probe was found not to exhibit light-induced toxicity even when irradiated for longer duration. All these experimental results demonstrated the promising standing of PA5 as a futuristic cell compatible potential stain for bioimaging and temporal profiling of DNA.

  11. WITHDRAWN: Amnioinfusion for meconium-stained liquor in labour.

    Science.gov (United States)

    Hofmeyr, G Justus

    2009-01-21

    Amnioinfusion aims to prevent or relieve umbilical cord compression during labour by infusing a solution into the uterine cavity. It is also thought to dilute meconium when present in the amniotic fluid and so reduce the risk of meconium aspiration. However, it may be that the mechanism of effect is that it corrects oligohydramnios (reduced amniotic fluid), for which thick meconium staining is a marker. The objective of this review was to assess the effects of amnioinfusion for meconium-stained liquor on perinatal outcome. The Cochrane Pregnancy and Childbirth Group trials register (October 2001) and the Cochrane Controlled Trials Register (Issue 3, 2001) were searched. Randomised trials comparing amnioinfusion with no amnioinfusion for women in labour with moderate or thick meconium-staining of the amniotic fluid. Eligibility and trial quality were assessed by one reviewer. Twelve studies, most involving small numbers of participants, were included. Under standard perinatal surveillance, amnioinfusion was associated with a reduction in the following: heavy meconium staining of the liquor (relative risk 0.03, 95% confidence interval 0.01 to 0.15); variable fetal heart rate deceleration (relative risk 0.65, 95% confidence interval 0.49 to 0.88); and reduced caesarean section overall (relative risk 0.82, 95% confidence interval 0.69 to 1.97). No perinatal deaths were reported. Under limited perinatal surveillance, amnioinfusion was associated with a reduction in the following: meconium aspiration syndrome (relative risk 0.24, 95% confidence interval 0.12 to 0.48); neonatal hypoxic ischaemic encephalopathy (relative risk 0.07, 95% confidence interval 0.01 to 0.56) and neonatal ventilation or intensive care unit admission (relative risk 0.56, 95% confidence interval 0.39 to 0.79); there was a trend towards reduced perinatal mortality (relative risk 0.34, 95% confidence interval 0.11 to 1.06). Amnioinfusion is associated with improvements in perinatal outcome

  12. LSENS: A General Chemical Kinetics and Sensitivity Analysis Code for homogeneous gas-phase reactions. Part 1: Theory and numerical solution procedures

    Science.gov (United States)

    Radhakrishnan, Krishnan

    1994-01-01

    LSENS, the Lewis General Chemical Kinetics and Sensitivity Analysis Code, has been developed for solving complex, homogeneous, gas-phase chemical kinetics problems and contains sensitivity analysis for a variety of problems, including nonisothermal situations. This report is part 1 of a series of three reference publications that describe LENS, provide a detailed guide to its usage, and present many example problems. Part 1 derives the governing equations and describes the numerical solution procedures for the types of problems that can be solved. The accuracy and efficiency of LSENS are examined by means of various test problems, and comparisons with other methods and codes are presented. LSENS is a flexible, convenient, accurate, and efficient solver for chemical reaction problems such as static system; steady, one-dimensional, inviscid flow; reaction behind incident shock wave, including boundary layer correction; and perfectly stirred (highly backmixed) reactor. In addition, the chemical equilibrium state can be computed for the following assigned states: temperature and pressure, enthalpy and pressure, temperature and volume, and internal energy and volume. For static problems the code computes the sensitivity coefficients of the dependent variables and their temporal derivatives with respect to the initial values of the dependent variables and/or the three rate coefficient parameters of the chemical reactions.

  13. Designing Solutions by a Student Centred Approach: Integration of Chemical Process Simulation with Statistical Tools to Improve Distillation Systems

    Directory of Open Access Journals (Sweden)

    Isabel M. Joao

    2017-09-01

    Full Text Available Projects thematically focused on simulation and statistical techniques for designing and optimizing chemical processes can be helpful in chemical engineering education in order to meet the needs of engineers. We argue for the relevance of the projects to improve a student centred approach and boost higher order thinking skills. This paper addresses the use of Aspen HYSYS by Portuguese chemical engineering master students to model distillation systems together with statistical experimental design techniques in order to optimize the systems highlighting the value of applying problem specific knowledge, simulation tools and sound statistical techniques. The paper summarizes the work developed by the students in order to model steady-state processes, dynamic processes and optimize the distillation systems emphasizing the benefits of the simulation tools and statistical techniques in helping the students learn how to learn. Students strengthened their domain specific knowledge and became motivated to rethink and improve chemical processes in their future chemical engineering profession. We discuss the main advantages of the methodology from the students’ and teachers perspective

  14. Influence of the pore structure and surface chemical properties of activated carbon on the adsorption of mercury from aqueous solutions

    International Nuclear Information System (INIS)

    Lu, Xincheng; Jiang, Jianchun; Sun, Kang; Wang, Jinbiao; Zhang, Yanping

    2014-01-01

    Highlights: • Activated carbons with different pore structure and surface chemical properties were prepared by modification process. • HgCl 2 as a pollution target to evaluate the adsorption performance. • Influence of pore structure and surface chemical properties of activated carbon on adsorption of mercury was investigated. -- Abstract: Reactivation and chemical modification were used to obtain modified activated carbons with different pore structure and surface chemical properties. The samples were characterized by nitrogen absorption–desorption, Fourier transform infrared spectroscopy and the Bothem method. Using mercury chloride as the target pollutant, the Hg 2+ adsorption ability of samples was investigated. The results show that the Hg 2+ adsorption capacity of samples increased significantly with increases in micropores and acidic functional groups and that the adsorption process was exothermic. Different models and thermodynamic parameters were evaluated to establish the mechanisms. It was concluded that the adsorption occurred through a monolayer mechanism by a two-speed process involving both rapid adsorption and slow adsorption. The adsorption rate was determined by chemical reaction

  15. A study comparing chemical peeling using modified jessner′s solution and 15% trichloroacetic acid versus 15% trichloroacetic acid in the treatment of melasma

    Directory of Open Access Journals (Sweden)

    Safoury Omar

    2009-01-01

    Full Text Available Background: Melasma is a symmetric progressive hyperpigmentation of the facial skin that occurs in all races but has a predilection for darker skin phenotypes. Depigmenting agents, laser and chemical peeling as classic Jessner′s solution, modified Jessner′s solution and trichloroacetic acid have been used alone and in combination in the treatment of melasma. Objectives: The aim of the study was to compare the therapeutic effect of combined 15% Trichloroacetic acid (TCA and modified Jessner′s solution with 15% TCA on melasma. Materials and Methods: Twenty married females with melasma (epidermal type, with a mean age of 38.25 years, were included in this study. All were of skin type III or IV. Fifteen percent TCA was applied to the whole face, with the exception of the left malar area to which combined TCA 15% and modified Jessner′s solution was applied. Results: Our results revealed statistically highly significant difference between MASI Score (Melasma Area and Severity Index between the right malar area and the left malar area. Conclusion: Modified Jessner′s solution proved to be useful as an adjuvant treatment with TCA in the treatment of melasma, improving the results and minimizing postinflammatory hyperpigmentation.

  16. Combining NMR ensembles and molecular dynamics simulations provides more realistic models of protein structures in solution and leads to better chemical shift prediction

    International Nuclear Information System (INIS)

    Lehtivarjo, Juuso; Tuppurainen, Kari; Hassinen, Tommi; Laatikainen, Reino; Peräkylä, Mikael

    2012-01-01

    While chemical shifts are invaluable for obtaining structural information from proteins, they also offer one of the rare ways to obtain information about protein dynamics. A necessary tool in transforming chemical shifts into structural and dynamic information is chemical shift prediction. In our previous work we developed a method for 4D prediction of protein 1 H chemical shifts in which molecular motions, the 4th dimension, were modeled using molecular dynamics (MD) simulations. Although the approach clearly improved the prediction, the X-ray structures and single NMR conformers used in the model cannot be considered fully realistic models of protein in solution. In this work, NMR ensembles (NMRE) were used to expand the conformational space of proteins (e.g. side chains, flexible loops, termini), followed by MD simulations for each conformer to map the local fluctuations. Compared with the non-dynamic model, the NMRE+MD model gave 6–17% lower root-mean-square (RMS) errors for different backbone nuclei. The improved prediction indicates that NMR ensembles with MD simulations can be used to obtain a more realistic picture of protein structures in solutions and moreover underlines the importance of short and long time-scale dynamics for the prediction. The RMS errors of the NMRE+MD model were 0.24, 0.43, 0.98, 1.03, 1.16 and 2.39 ppm for 1 Hα, 1 HN, 13 Cα, 13 Cβ, 13 CO and backbone 15 N chemical shifts, respectively. The model is implemented in the prediction program 4DSPOT, available at http://www.uef.fi/4dspothttp://www.uef.fi/4dspot.

  17. Combining NMR ensembles and molecular dynamics simulations provides more realistic models of protein structures in solution and leads to better chemical shift prediction

    Energy Technology Data Exchange (ETDEWEB)

    Lehtivarjo, Juuso, E-mail: juuso.lehtivarjo@uef.fi; Tuppurainen, Kari; Hassinen, Tommi; Laatikainen, Reino [University of Eastern Finland, School of Pharmacy (Finland); Peraekylae, Mikael [University of Eastern Finland, Institute of Biomedicine (Finland)

    2012-03-15

    While chemical shifts are invaluable for obtaining structural information from proteins, they also offer one of the rare ways to obtain information about protein dynamics. A necessary tool in transforming chemical shifts into structural and dynamic information is chemical shift prediction. In our previous work we developed a method for 4D prediction of protein {sup 1}H chemical shifts in which molecular motions, the 4th dimension, were modeled using molecular dynamics (MD) simulations. Although the approach clearly improved the prediction, the X-ray structures and single NMR conformers used in the model cannot be considered fully realistic models of protein in solution. In this work, NMR ensembles (NMRE) were used to expand the conformational space of proteins (e.g. side chains, flexible loops, termini), followed by MD simulations for each conformer to map the local fluctuations. Compared with the non-dynamic model, the NMRE+MD model gave 6-17% lower root-mean-square (RMS) errors for different backbone nuclei. The improved prediction indicates that NMR ensembles with MD simulations can be used to obtain a more realistic picture of protein structures in solutions and moreover underlines the importance of short and long time-scale dynamics for the prediction. The RMS errors of the NMRE+MD model were 0.24, 0.43, 0.98, 1.03, 1.16 and 2.39 ppm for {sup 1}H{alpha}, {sup 1}HN, {sup 13}C{alpha}, {sup 13}C{beta}, {sup 13}CO and backbone {sup 15}N chemical shifts, respectively. The model is implemented in the prediction program 4DSPOT, available at http://www.uef.fi/4dspothttp://www.uef.fi/4dspot.

  18. Cell wall staining with Trypan Blue enables quantitative analysis of morphological changes in yeast cells

    Directory of Open Access Journals (Sweden)

    Johannes eLiesche

    2015-02-01

    Full Text Available Yeast cells are protected by a cell wall that plays an important role in the exchange of substances with the environment. The cell wall structure is dynamic and can adapt to different physiological states or environmental conditions. For the investigation of morphological changes, selective staining with fluorescent dyes is a valuable tool. Furthermore, cell wall staining is used to facilitate sub-cellular localization experiments with fluorescently-labeled proteins and the detection of yeast cells in non-fungal host tissues. Here, we report staining of Saccharomyces cerevisiae cell wall with Trypan Blue, which emits strong red fluorescence upon binding to chitin and yeast glucan; thereby, it facilitates cell wall analysis by confocal and super-resolution microscopy. The staining pattern of Trypan Blue was similar to that of the widely used UV-excitable, blue fluorescent cell wall stain Calcofluor White. Trypan Blue staining facilitated quantification of cell size and cell wall volume when utilizing the optical sectioning capacity of a confocal microscope. This enabled the quantification of morphological changes during growth under anaerobic conditions and in the presence of chemicals, demonstrating the potential of this approach for morphological investigations or screening assays.

  19. Cell wall staining with Trypan blue enables quantitative analysis of morphological changes in yeast cells.

    Science.gov (United States)

    Liesche, Johannes; Marek, Magdalena; Günther-Pomorski, Thomas

    2015-01-01

    Yeast cells are protected by a cell wall that plays an important role in the exchange of substances with the environment. The cell wall structure is dynamic and can adapt to different physiological states or environmental conditions. For the investigation of morphological changes, selective staining with fluorescent dyes is a valuable tool. Furthermore, cell wall staining is used to facilitate sub-cellular localization experiments with fluorescently-labeled proteins and the detection of yeast cells in non-fungal host tissues. Here, we report staining of Saccharomyces cerevisiae cell wall with Trypan Blue, which emits strong red fluorescence upon binding to chitin and yeast glucan; thereby, it facilitates cell wall analysis by confocal and super-resolution microscopy. The staining pattern of Trypan Blue was similar to that of the widely used UV-excitable, blue fluorescent cell wall stain Calcofluor White. Trypan Blue staining facilitated quantification of cell size and cell wall volume when utilizing the optical sectioning capacity of a confocal microscope. This enabled the quantification of morphological changes during growth under anaerobic conditions and in the presence of chemicals, demonstrating the potential of this approach for morphological investigations or screening assays.

  20. Novel 'heavy' dyes for retinal membrane staining during macular surgery: multicenter clinical assessment

    NARCIS (Netherlands)

    Veckeneer, Marc; Mohr, Andreas; Alharthi, Essam; Azad, Rajvardhan; Bashshur, Ziad F.; Bertelli, Enrico; Bejjani, Riad A.; Bouassida, Brahim; Bourla, Dan; Crespo, Iñigo Corcóstegui; Fahed, Charbel; Fayyad, Faisal; Mura, Marco; Nawrocki, Jerzy; Rivett, Kelvin; Scharioth, Gabor B.; Shkvorchenko, Dmitry O.; Szurman, Peter; van Wijck, Hein; Wong, Ian Y.; Wong, David S. H.; Frank, Johannes; Oellerich, Silke; Bruinsma, Marieke; Melles, Gerrit R. J.

    2014-01-01

    Purpose: To evaluate the feasibility of two novel heavy' dye solutions for staining the internal limiting membrane (ILM) and epiretinal membranes (ERMs), without the need for a prior fluid-air exchange, during macular surgery. Methods: In this prospective nonrandomized multicenter cohort study, the

  1. Influence of physical and chemical parameters on the irradiation of aqueous solutions of phenol by electron beam

    International Nuclear Information System (INIS)

    Pellizzari, Fabien

    2005-01-01

    The aim of this work was the study of the influence of different parameters by electron beam irradiation on the decomposition of phenol in aqueous solution. A simulation based on a simplified mechanism emphasized the importance of the oxygenation of the solutions in the removal of phenol by ionisation. A model of the reactor used was proposed from the study of the influence of the beam energy on the decomposition of phenol. Penetration depths of the electrons were determined. Phenol degradation was found to increase with the dose rate. The fraction of the dose into several passages under the electron beam improved the abatement of the phenol. The reoxygenation of the solutions between each passage and the kinetic expressions of irradiation could explain this effect. As expected, the first by-products identified were originated from the reaction of phenol with hydroxyl radicals. [fr

  2. Investigation Of The Color Changing Properties Of Wood Stain Derived From Pinar Leaves

    Directory of Open Access Journals (Sweden)

    Abdi Atılgan

    2011-11-01

    Full Text Available This study was designed to develop an environmentally friendly wood stain derived pinar (Quercus aucheri leaves and determine the color stability of this stain when exposed to UV light irradiation. Wood stains derived from pinar leaves were prepared from aqueous solution with %3 iron (FeSO4.7H2O , % 5 alum ((KAl(SO42.12H2O, and % 10 vinegar mordant mixtures. Scots pine (Pinus sylvestris L., Turkish oriental beech (Fagus orientalis Lipsky and oak (Quercus petraea L. wood specimens were used as staining substrates. After treatment with the stain, the wood panels were exposed to UV light irradiation for periods of 100, 200, and 300 hours and determinated the total color changes was according to ISO 2470 standards. Results showed that wood stain derived from pinar extract provided some color stability after UV irradiation. According to results, Scots pine specimens treated with the pinar extract + iron mixture provided the smallest total color changes. Meanwhile the highest total color change provided on the Scots pine treated with pinar extract+alum mixture.

  3. An investigation on the chemical stability and a novel strategy for long-term stabilization of diphenylalanine nanostructures in aqueous solution

    Directory of Open Access Journals (Sweden)

    H. Nezammahalleh

    2015-01-01

    Full Text Available The stability of diphenylalanine (FF microwires and microtubes in phosphate buffer solution was investigated and a novel strategy was developed for their chemical stabilization. This stability investigation was carried out by optical microscopy and by high performance liquid chromatography (HPLC. These microstructures dissolve in the solution depending upon their degree of FF saturation. The dissolution mechanisms of the structures in kinetically limited processes were found by accurately fitting the experimental dissolution data to a theoretical kinetic equation. The dissolution data were well fitted to the particular Avrami-Erofe’ev kinetic expression (R2 > 0.98. These findings suggest that the structures can be stabilized by a decrease in the hydration of the constituent molecules thorough a chemical conformational induced transition upon heat treatment. The stable microtubes were fabricated in a novel three step procedure consisting of the reduction of silver ions in unstable FF microtubes by a citrate reductant, the stabilization by chemical conformational induced transition upon heat treatment, and the consequent oxidation of the reduced silver by a persulfate oxidant. These materials were characterized by electron microscopy and powder X-ray diffraction techniques. The long-term stability of both structures was also confirmed by optical microscopy and HPLC.

  4. Study of the crystallographic phase change on copper (I) selenide thin films prepared through chemical bath deposition by varying the pH of the solution

    Energy Technology Data Exchange (ETDEWEB)

    Sandoval-Paz, M.G., E-mail: myrnasandoval@udec.cl [Departament of Physics, Faculty of Physical Sciences and Mathematics, University of Concepcion, Box 160-C, Concepción (Chile); Rodríguez, C.A. [Department of Materials Engineering, Faculty of Engineering, University of Concepción, Edmundo Larenas 270, Concepción 4070409 (Chile); Porcile-Saavedra, P.F. [Departament of Physics, Faculty of Physical Sciences and Mathematics, University of Concepcion, Box 160-C, Concepción (Chile); Trejo-Cruz, C. [Department of Physics, Faculty of Science, University of Biobío, Avenue Collao 1202, Box 5C, Concepción 4051381 (Chile)

    2016-07-15

    Copper (I) selenide thin films with orthorhombic and cubic structure were deposited on glass substrates by using the chemical bath deposition technique. The effects of the solution pH on the films growth and subsequently the structural, optical and electrical properties of the films were studied. Films with orthorhombic structure were obtained from baths wherein both metal complex and hydroxide coexist; while films with cubic structure were obtained from baths where the metal hydroxide there is no present. The structural modifications are accompanied by changes in bandgap energy, morphology and electrical resistivity of the films. - Graphical abstract: “Study of the crystallographic phase change on copper (I) selenide thin films prepared through chemical bath deposition by varying the pH of the solution” by M. G. Sandoval-Paz, C. A. Rodríguez, P. F. Porcile-Saavedra, C. Trejo-Cruz. Display Omitted - Highlights: • Copper (I) selenide thin films were obtained by chemical bath deposition. • Orthorhombic to cubic phase change was induced by varying the reaction solution pH. • Orthorhombic phase is obtained mainly from a hydroxides cluster mechanism. • Cubic phase is obtained mainly from an ion by ion mechanism. • Structural, optical and electrical properties are presented as a function of pH.

  5. Changes in soil toxicity by phosphate-aided soil washing: effect of soil characteristics, chemical forms of arsenic, and cations in washing solutions.

    Science.gov (United States)

    Jho, Eun Hea; Im, Jinwoo; Yang, Kyung; Kim, Young-Jin; Nam, Kyoungphile

    2015-01-01

    This study was set to investigate the changes in the toxicity of arsenic (As)-contaminated soils after washing with phosphate solutions. The soil samples collected from two locations (A: rice paddy and B: forest land) of a former smelter site were contaminated with a similar level of As. Soil washing (0.5 M phosphate solution for 2 h) removed 24.5% As, on average, in soil from both locations. Regardless of soil washing, Location A soil toxicities, determined using Microtox, were greater than that of Location B and this could be largely attributed to different soil particle size distribution. With soils from both locations, the changes in As chemical forms resulted in either similar or greater toxicities after washing. This emphasizes the importance of considering ecotoxicological aspects, which are likely to differ depending on soil particle size distribution and changes in As chemical forms, in addition to the total concentration based remedial goals, in producing ecotoxicologically-sound soils for reuse. In addition, calcium phosphate used as the washing solution seemed to contribute more on the toxic effects of the washed soils than potassium phosphate and ammonium phosphate. Therefore, it would be more appropriate to use potassium or ammonium phosphate than calcium phosphate for phosphate-aided soil washing of the As-contaminated soils. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. Ni removal from aqueous solutions by chemical reduction: Impact of pH and pe in the presence of citrate

    International Nuclear Information System (INIS)

    Li, Chi-Wang; Yu, Jui-Hsuan; Liang, Yang-Min; Chou, Yi-Hsuan; Park, Hyung-June; Choo, Kwang-Ho; Chen, Shiao-Shing

    2016-01-01

    The chemical precipitation of Ni ions from industrial wastewater at alkaline pH values creates waste chemical sludge (e.g., Ni(OH)_2). We herein focused on Ni removal via chemical reduction using dithionite, by converting Ni(II) to its elemental or other valuable forms. Without the presence of a chelator (e.g., citrate), the nickel reduction efficiency increased with increasing dithionite:Ni molar ratio, reaching 99% at ratios above 3:1. The effect of pH on Ni reduction was in agreement with the standard redox potentials (pe"0) of dithionite, which became more negative with an increase in pH leading to greater Ni reduction efficiencies. With the formation of Ni-citrate chelates, however, the Ni reduction deteriorated. Elevated pH and temperature improved nickel reduction, due to the greater reducing power of dithionite. The optimal pH value for Ni(II) reduction was found to be 8. Injecting Cu seed particles enhanced the rate and amount of Ni reduced. NiS and Ni_3S_2 were identified in the crystal of the resulting solids by X-ray crystallography, and the presence of elemental Ni was explained by X-ray photoelectron spectroscopy. The chemical reduction of actual printed circuit board wastewater with the dithionite:Ni(II) molar ratio dose of 12:1 retrieved 99% nickel after 30-min reaction at 40 °C.

  7. Osmotic Pressure of Aqueous Electrolyte Solutions via Molecular Simulations of Chemical Potentials: Application to NaCl.

    Czech Academy of Sciences Publication Activity Database

    Smith, W.R.; Moučka, F.; Nezbeda, Ivo

    2016-01-01

    Roč. 407, Sl (2016), s. 76-83 ISSN 0378-3812 Grant - others:NSERC(CA) OGP1041 Institutional support: RVO:67985858 Keywords : osmotic pressure * chemical potential * molecular simulation Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.473, year: 2016

  8. Ni removal from aqueous solutions by chemical reduction: Impact of pH and pe in the presence of citrate

    Energy Technology Data Exchange (ETDEWEB)

    Li, Chi-Wang, E-mail: chiwang@mail.tku.edu.tw [Department of Water Resources and Environmental Engineering, Tamkang University, No. 151 Yingzhuan Road, Tamsui District, New Taipei City, 25137, Taiwan (China); Yu, Jui-Hsuan [Department of Water Resources and Environmental Engineering, Tamkang University, No. 151 Yingzhuan Road, Tamsui District, New Taipei City, 25137, Taiwan (China); Department of Marine Leisure and Tourism, Taipei College of Maritime Technology, No. 150, Sec. 3, Binhai Road, Tamsui District, New Taipei City, 251, Taiwan (China); Liang, Yang-Min; Chou, Yi-Hsuan [Department of Water Resources and Environmental Engineering, Tamkang University, No. 151 Yingzhuan Road, Tamsui District, New Taipei City, 25137, Taiwan (China); Park, Hyung-June [Department of Environmental Engineering, Kyungpook National University, 80 Daehak-ro, Buk-gu, Daegu, 41566 (Korea, Republic of); Choo, Kwang-Ho, E-mail: chookh@knu.ac.kr [Department of Environmental Engineering, Kyungpook National University, 80 Daehak-ro, Buk-gu, Daegu, 41566 (Korea, Republic of); Chen, Shiao-Shing [Institute of Environmental Engineering and Management, National Taipei University of Technology, No. 1, Sec. 3, Chung-Hsiao E. Road, Taipei, 106, Taiwan (China)

    2016-12-15

    The chemical precipitation of Ni ions from industrial wastewater at alkaline pH values creates waste chemical sludge (e.g., Ni(OH){sub 2}). We herein focused on Ni removal via chemical reduction using dithionite, by converting Ni(II) to its elemental or other valuable forms. Without the presence of a chelator (e.g., citrate), the nickel reduction efficiency increased with increasing dithionite:Ni molar ratio, reaching 99% at ratios above 3:1. The effect of pH on Ni reduction was in agreement with the standard redox potentials (pe{sup 0}) of dithionite, which became more negative with an increase in pH leading to greater Ni reduction efficiencies. With the formation of Ni-citrate chelates, however, the Ni reduction deteriorated. Elevated pH and temperature improved nickel reduction, due to the greater reducing power of dithionite. The optimal pH value for Ni(II) reduction was found to be 8. Injecting Cu seed particles enhanced the rate and amount of Ni reduced. NiS and Ni{sub 3}S{sub 2} were identified in the crystal of the resulting solids by X-ray crystallography, and the presence of elemental Ni was explained by X-ray photoelectron spectroscopy. The chemical reduction of actual printed circuit board wastewater with the dithionite:Ni(II) molar ratio dose of 12:1 retrieved 99% nickel after 30-min reaction at 40 °C.

  9. Port wine stain on a child's face (image)

    Science.gov (United States)

    Port wine stains are always present at birth. In an infant, they are flat, pink, vascular lesions. Common locations ... may be present anywhere on the body. Port wine stains may appear in association with other syndromes.

  10. SIMULTANEOUS ABSORPTION AND DESORPTION WITH REVERSIBLE 1ST-ORDER CHEMICAL-REACTION - ANALYTICAL SOLUTION AND NEGATIVE ENHANCEMENT FACTORS

    NARCIS (Netherlands)

    WINKELMAN, JGM; BEENACKERS, AACM

    The problem of ps absorption accompanied by a first-order reversible reaction, producing a volatile reaction product, is considered. A general analytical solution is developed for the film model, resulting in explicit relations for the concentration profiles in the film and for the mass transfer

  11. Modified Genta triple stain for identifying Helicobacter pylori.

    OpenAIRE

    el-Zimaity, H M; Wu, J; Graham, D Y

    1999-01-01

    AIM: To evaluate whether lead nitrate could replace uranyl nitrate in the Genta stain for H pylori without sacrificing the advantages of the triple stain (Steiner silver impregnation combined with Alcian blue and haematoxylin/eosin (H&E)). METHODS: A comparison was made in 16 specimens between the original triple stain and the revised version. One pathologist evaluated all sections. RESULTS: Direct substitution of lead nitrate for uranium nitrate produced well stained organisms without interf...

  12. Utility of Modified Ultrafast Papanicolaou Stain in Cytological Diagnosis.

    Science.gov (United States)

    Sinkar, Prachi; Arakeri, Surekha Ulhas

    2017-03-01

    Need for minimal turnaround time for assessing Fine Needle Aspiration Cytology (FNAC) has encouraged innovations in staining techniques that require lesser staining time with unequivocal cell morphology. The standard protocol for conventional Papanicolaou (PAP) stain requires about 40 minutes. To overcome this, Ultrafast Papanicolaou (UFP) stain was introduced which reduces staining time to 90 seconds and also enhances the quality. However, reagents required for this were not easily available hence, Modified Ultrafast Papanicolaou (MUFP) stain was introduced subsequently. To assess the efficacy of MUFP staining by comparing the quality of MUFP stain with conventional PAP stain. FNAC procedure was performed by using 10 ml disposable syringe and 22-23 G needle. Total 131 FNAC cases were studied which were lymph node (30), thyroid (38), breast (22), skin and soft tissue (24), salivary gland (11) and visceral organs (6). Two smears were prepared and stained by MUFP and conventional PAP stain. Scores were given on four parameters: background of smears, overall staining pattern, cell morphology and nuclear staining. Quality Index (QI) was calculated from ratio of total score achieved to maximum score possible. Statistical analysis using chi square test was applied to each of the four parameters before obtaining the QI in both stains. Students t-test was applied to evaluate the efficacy of MUFP in comparison with conventional PAP stain. The QI of MUFP for thyroid, breast, lymph node, skin and soft tissue, salivary gland and visceral organs was 0.89, 0.85, 0.89, 0.83, 0.92, and 0.78 respectively. Compared to conventional PAP stain QI of MUFP smears was better in all except visceral organ cases and was statistically significant. MUFP showed clear red blood cell background, transparent cytoplasm and crisp nuclear features. MUFP is fast, reliable and can be done with locally available reagents with unequivocal morphology which is the need of the hour for a cytopathology set-up.

  13. Discriminative staining methods for the nervous system: luxol fast blue--periodic acid-Schiff--hematoxylin triple stain and subsidiary staining methods.

    Science.gov (United States)

    Goto, N

    1987-09-01

    This paper describes a new series of staining methods which can discriminatively demonstrate every structure of the nervous system, including axons and capillaries, in animal and human materials. Methods described in this paper consist of one primary stain, luxol fast blue-periodic acid Schiff-hematoxylin (LPH) and six different subsidiary staining methods. The LPH triple stain can precisely differentiate the following structures: neurons (Nissl bodies, cytoplasm, nuclear membrane and nucleolus), various kinds of nuclei (glia, ependyma, endothelium, leucocyte, connective tissue, etc.), myelin sheaths, neuronal processes (axons and dendrites), reacted glial cell bodies (protoplasmic astrocytes, foamy cells, etc.), blood vessels (arteries, veins and capillaries), meninges, intervening connective tissue, erythrocytes, lipofuscin granules, amyloid bodies, and others. Subsidiary staining methods are also described briefly. Applications are discussed in the context of staining technology and neuromorphological research.

  14. Theoretical study of the influence of chemical reactions and physical parameters on the convective dissolution of CO2 in aqueous solutions

    Science.gov (United States)

    Loodts, Vanessa; Rongy, Laurence; De Wit, Anne

    2014-05-01

    Subsurface carbon sequestration has emerged as a promising solution to the problem of increasing atmospheric carbon dioxide (CO2) levels. How does the efficiency of such a sequestration process depend on the physical and chemical characteristics of the storage site? This question is emblematic of the need to better understand the dynamics of CO2 in subsurface formations, and in particular, the properties of the convective dissolution of CO2 in the salt water of aquifers. This dissolution is known to improve the safety of the sequestration by reducing the risks of leaks of CO2 to the atmosphere. Buoyancy-driven convection makes this dissolution faster by transporting dissolved CO2 further away from the interface. Indeed, upon injection, the less dense CO2 phase rises above the aqueous layer where it starts to dissolve. The dissolved CO2 increases the density of the aqueous solution, thereby creating a layer of denser CO2-rich solution above less dense solution. This unstable density gradient in the gravity field is at the origin of convection. In this framework, we theoretically investigate the effect of CO2 pressure, salt concentration, temperature, and chemical reactions on the dissolution-driven convection of CO2 in aqueous solutions. On the basis of a linear stability analysis, we assess the stability of the time-dependent density profiles developing when CO2 dissolves in an aqueous layer below it. We predict that increasing CO2 pressure destabilizes the system with regard to buoyancy-driven convection, because it increases the density gradient at the origin of the instability. By contrast, increasing salt concentration or temperature stabilizes the system via effects on CO2 solubility, solutal expansion coefficient, diffusion coefficient and on the viscosity and density of the solution. We also show that a reaction of CO2 with chemical species dissolved in the aqueous solution can either enhance or decrease the amplitude of the convective dissolution compared

  15. 7 CFR 28.442 - Middling Yellow Stained Color.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Middling Yellow Stained Color. 28.442 Section 28.442... Stained Color. Middling Yellow Stained Color is American Upland cotton which in color is deeper than Middling Tinged Color. [57 FR 34498, Aug. 5, 1992] below color grade cotton ...

  16. 7 CFR 28.441 - Strict Middling Yellow Stained Color.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Strict Middling Yellow Stained Color. 28.441 Section... Strict Middling Yellow Stained Color. Strict Middling Yellow Stained Color is color which is deeper than that of Strict Middling Tinged Color. [57 FR 34498, Aug. 5, 1992] ...

  17. CD3 immunohistochemical staining in diagnosis of lymphocytic colitis

    DEFF Research Database (Denmark)

    Fiehn, Anne-Marie Kanstrup; Engel, Ulla; Holck, Susanne

    2016-01-01

    and eosin (HE) stainings were available. At the second assessment, a supplementary CD3 immunohistochemical staining was also available. The aim was to evaluate whether a supplementary CD3 would increase the diagnostic agreement among pathologists, and whether a CD3 stain would change the diagnosis based...

  18. The role of a chemical bond in thermal expansion of TlIn1-xYbxSe2 solid solutions

    International Nuclear Information System (INIS)

    Zarbaliev, M.M.; Sardarova, N.S.; Mamedov, E.G.; Nagiyev, A.B.

    2008-01-01

    Report focuses on the study of the role of the chemical bond in the thermal expansion of solid solutions TLIn 1 -x Yb x Se 2 (0chemical bonds between atoms in a crystal lattice one and the same. It leads to the same temperature changes of enharmonic part of the thermal variations of atoms in the crystal lattice. But the level of anharmonism depends on the character interatomic interaction and temperature, which defined the value of α

  19. Influence of Chemical Composition on Rupture Properties at 1200 Degrees F. of Forged Chromium-Cobalt-Nickel-Iron Base Alloys in Solution-Treated and Aged Condition

    Science.gov (United States)

    Reynolds, E E; Freeman, J W; White, A E

    1951-01-01

    The influence of systematic variations of chemical composition on rupture properties at 1200 degrees F. was determined for 62 modifications of a basic alloy containing 20 percent chromium, 20 percent nickel, 20 percent cobalt, 3 percent molybdenum, 2 percent tungsten, 1 percent columbium, 0.15 percent carbon, 1.7 percent manganese, 0.5 percent silicon, 0.12 percent nitrogen and the balance iron. These modifications included individual variations of each of 10 elements present and simultaneous variations of molybdenum, tungsten, and columbium. Laboratory induction furnace heats were hot-forged to round bar stock, solution-treated at 2200 degrees F., and aged at 1400 degrees F. The melting and fabrication conditions were carefully controlled in order to minimize all variable effects on properties except chemical composition. Information is presented which indicates that melting and hot-working conditions play an important role in high-temperature properties of alloys of the type investigated.

  20. The influence of the "cage" effect on the mechanism of reversible bimolecular multistage chemical reactions proceeding from different sites in solutions.

    Science.gov (United States)

    Doktorov, Alexander B

    2016-08-28

    Manifestations of the "cage" effect at the encounters of reactants have been theoretically treated on the example of multistage reactions (including bimolecular exchange reactions as elementary stages) proceeding from different active sites in liquid solutions. It is shown that for reactions occurring near the contact of reactants, consistent consideration of quasi-stationary kinetics of such multistage reactions (possible in the framework of the encounter theory only) can be made on the basis of chemical concepts of the "cage complex," just as in the case of one-site model described in the literature. Exactly as in the one-site model, the presence of the "cage" effect gives rise to new channels of reactant transformation that cannot result from elementary event of chemical conversion for the given reaction mechanism. Besides, the multisite model demonstrates new (as compared to one-site model) features of multistage reaction course.

  1. Chemical modification of silica gel with synthesized Schiff base hydrazone derivative and application for preconcentration and separation of U(VI) ions from aqueous solutions

    International Nuclear Information System (INIS)

    Gamze Karayel Incili; Gul Asiye Aycik

    2014-01-01

    Schiff base hydrazone derivative (HL) sorbent was synthesized according to the literature to be used in the adsorption and preconcentration of U(VI) ions from aqueous solution and it was exposed to immobilization, and new solid support material was obtained. For this purpose, Schiff base hydrazone derivative (HL) was chemically bonded to silica gel surface immobilized 3-aminopropyl trimethoxysilane, then analyzed by Fourier transform infrared, Brunauer-Emmett-Teller, scanning electron microscopy and elemental analysis. The influence of the solution pH, amount of sorbent, contact time, temperature, foreign ion effect and initial U(VI) concentration was investigated. The maximum U(VI) uptake capacity was found to be 8.46 mg/g. (author)

  2. Sorption behaviour of W, Hf, Lu, U, and Th on ion exchangers from HCl/H2O2 solutions. Model experiments for chemical studies of seaborgium (Sg)

    International Nuclear Information System (INIS)

    Schumann, D.; Andrassy, M.; Nitsche, H.; Misiak, R.; Schaedel, M.; Bruechle, W.; Schausten, B.; Kratz, J.V.

    1997-08-01

    In model experiments with W, Hf, Th, and U radionuclides, a chemical system was developed for the separation of seaborgium from element 104 and heavy actinides, i.e., cation exchange on DOWEX 50 x 8 from solutions containing 0.1-1.0 M HCl and 0.5-2.0 vol.% H 2 O 2 . The system should be suitable for fast on-line experiments if seaborgium exibits a non-uranium-like behaviour. Adding hydrogen peroxide to mixed HCl/HF solutions suppresses the partial sorption of W and, presumably seaborgium, on the cation exchanger. This way, the elution volume can be minimized. Prospects for anion exchange separations of group 6 from 4 elements are also briefly discussed. (orig.)

  3. Sm-doped CeO2 single buffer layer for YBCO coated conductors by polymer assisted chemical solution deposition (PACSD) method

    International Nuclear Information System (INIS)

    Li, G.; Pu, M.H.; Sun, R.P.; Wang, W.T.; Wu, W.; Zhang, X.; Yang, Y.; Cheng, C.H.; Zhao, Y.

    2008-01-01

    An over 150 nm thick Sm 0.2 Ce 0.8 O 1.9-x (SCO) single buffer layer has been deposited on bi-axially textured NiW (2 0 0) alloy substrate. Highly in-plane and out-of-plane oriented, dense, smooth and crack free SCO single layer has been obtained via a polymer-assisted chemical solution deposition (PACSD) approach. YBCO thin film has been deposited equally via a PACSD route on the SCO-buffered NiW, the as grown YBCO yielding a sharp transition at T c0 = 87 K as well as J c (0 T, 77 K) ∼ 1 MA/cm 2 . These results indicates that RE (lanthanides other than Ce) doping may be an effective approach to improve the critical thickness of solution derived CeO 2 film, which renders it a promising candidate as single buffer layer for YBCO coated conductors

  4. Waste treatment process for removal of contaminants from aqueous, mixed-waste solutions using sequential chemical treatment and crossflow microfiltration, followed by dewatering

    Science.gov (United States)

    Vijayan, S.; Wong, C.F.; Buckley, L.P.

    1994-11-22

    In processes of this invention aqueous waste solutions containing a variety of mixed waste contaminants are treated to remove the contaminants by a sequential addition of chemicals and adsorption/ion exchange powdered materials to remove the contaminants including lead, cadmium, uranium, cesium-137, strontium-85/90, trichloroethylene and benzene, and impurities including iron and calcium. Staged conditioning of the waste solution produces a polydisperse system of size enlarged complexes of the contaminants in three distinct configurations: water-soluble metal complexes, insoluble metal precipitation complexes, and contaminant-bearing particles of ion exchange and adsorbent materials. The volume of the waste is reduced by separation of the polydisperse system by cross-flow microfiltration, followed by low-temperature evaporation and/or filter pressing. The water produced as filtrate is discharged if it meets a specified target water quality, or else the filtrate is recycled until the target is achieved. 1 fig.

  5. Controlled synthesis of high-quality nickel sulfide chain-like tubes and echinus-like nanostructures by a solution chemical route

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Yahui [School of Materials Science and Engineering, Beijing University of Aeronautics and Astronautics, Beijing 100083 (China); Guo Lin [School of Materials Science and Engineering, Beijing University of Aeronautics and Astronautics, Beijing 100083 (China); He Lin [Department of Physics, Peking University, Beijing 100871 (China); Liu, Kang [Department of Physics, Peking University, Beijing 100871 (China); Chen Chinping [Department of Physics, Peking University, Beijing 100871 (China); Zhang Qi [School of Materials Science and Engineering, Beijing University of Aeronautics and Astronautics, Beijing 100083 (China); Wu Ziyu [Institute of High Energy Physics, Chinese of Academy of Science, Beijing 100039 (China)

    2007-12-05

    Chain-like NiS tubes and echinus-like nickel sulfide (Ni{sub 3}S{sub 2}) nanostructures were synthesized successfully by a solution chemical route. The growth models of these two materials and the most possible mutation process between these two different morphologies are discussed. The temperature and field dependent magnetizations, M(T) and M(H), show that both the samples have a very weak ferromagnetism and exhibit a strong paramagnetic response in a high applied field.

  6. Study of the chemical composition of waters in Morro do Ferro (MG), Brazil: transport of thorium and several tracer alements in solution

    International Nuclear Information System (INIS)

    Pivetta, F.R.

    1983-01-01

    The chemical composition of surface and well waters in the Morro do Ferro (Pocos de Caldas-MG.) Brazil, because the transport in solution may represent one important way of environmental contamination is studied. Samples of one stream in the base of the hill, of perfuration wells and of one galery were analysed in the period from 1980 (October) to 1982 (May). The contents of Mn, Fe, SiO 2 , SO 2- 4 , PO 3- 4 , NO - 3 and CO 2 is analysed in situ. (M.J.C.) [pt

  7. Effect of molecular weight on radiation chemical degradation yield of chain scission of γ-irradiated chitosan in solid state and in aqueous solution

    International Nuclear Information System (INIS)

    Tahtat, Djamel; Mahlous, Mohamed; Benamer, Samah; Nacer Khodja, Assia; Larbi Youcef, Souad

    2012-01-01

    Chitosan A 1 , A 2 and A 3 with molecular weight of 471, 207 and 100 kDa respectively, produced from squid pen chitin was degraded by gamma rays in the solid state and in aqueous solution with various doses in air at ambient temperature. Effect of molecular weight on radiation chemical degradation yield of chain scission and degradation rate constants of γ-irradiated chitosan in solid state and in aqueous solution was investigated. The radiation chemical degradation yield G (s) and degradation rate values were calculated. The molecular weight changes were monitored by capillary viscometry method and the chemical structure changes were followed by UV analysis. The results showed that, the degradation of chitosan was faster in solution, than in solid state. The values of G (s) in solid state and in aqueous solution were respectively 1.1×10 −8 mol/J and 0.074×10 −7 mol/J for A 1 , 4.42×10 −8 mol/J and 0.28×10 −7 mol/J for A 2 and 6.08×10 −8 mol/J and 0.38×10 −7 mol/J for A 3 . Degradation rate constants values ranged from 0.41×10 −5 to 2.1×10 −5 kGy −1 in solid state, whereas in solution they ranged from 13×10 −5 to 68×10 −5 kGy −1 . The chitosan A 3 was more sensitive to radiolysis than A 1 and A 2 . The chain scission yield, G (s) and degradation rate constants seems to be greatly influenced by the initial molecular weight of the chitosan. Structural changes in irradiated chitosan are revealed by the apparition of absorption peaks at 261 and 295 nm, which could be attributed to the formation of carbonyl groups. In both conditions the peak intensity was higher in chitosan A 3 than in A 1 and A 2 , the oxidative products decreased with increasing molecular weight of chitosan. - Highlights: ► We investigated the effects of MW on G (s) value of γ-irradiated chitosan in solid and aqueous state. ► Chitosan with low molecular weight was more sensitive to radiolysis than high molecular weight. ► G (s) value and degradation rate

  8. Possibilities of chemical isolation of element 106 from aqueous solutions according to the model experiments with short lived tungsten isotopes

    International Nuclear Information System (INIS)

    Szeglowski, Z.; Bruchertseifer, H.; Brudanin, V.B.

    1993-01-01

    A rapid method for continuous separation of short-lived tungsten isotopes from the lanthanides has been developed. It consists in transforming nuclear reaction products from the target by an aerosol jet to an absorber where the KCl particulates are dissolved in 0.2 M HF and percolating the product solution through three successively linked columns filled with ion exchange resins Dowex 50X8 (cationite), Dowex 1X8 (anionite) and again Dowex 50X8. 3 refs

  9. Manufacture of Bi-cuprate thin films on MgO single crystal substrates by chemical solution deposition

    DEFF Research Database (Denmark)

    Grivel, Jean-Claude; Bertelsen, Christian Vinther; Andersen, Niels Hessel

    2014-01-01

    Bi2Sr2CaCu2O8 thin films have been deposited on MgO single crystal substrates by spin-coating a solution based on 2-ethylhexanoate precursors dissolved in xylene. Pyrolysis takes place between 200°C and 450°C and is accompanied by the release of 2-ethylhexanoic acid, CO2 and H2O vapour. Highly c...

  10. Tribological performance evaluation of coated steels with TiNbCN subjected to tribo-chemical wear in Ringers solution

    International Nuclear Information System (INIS)

    Caballero G, J.; Aperador, W.; Caicedo, J. C.

    2016-01-01

    With the aim of generating solutions against the deterioration of the joint prostheses, it was studied the tribo-corrosive behavior of titanium niobium carbonitride (TiNbCN) deposited on stainless steel AISI 316 LVM using the technique of magnetron sputtering physical vapor deposition. The tests were performed in a balanced saline solution (Ringers solution) which represents the characteristics of the body fluids, using an equipment where the micro-abrasive wear is generated by the contact of micro particles in the system; the micro-abrasion-corrosion mechanism is described by means of the incorporation of an electrochemical cell consisting of three electrodes. Both the substrate and the coating, were subjected to micro-abrasive wear simultaneously with the electrochemical tests of Tafel polarization curves and electrochemical impedance spectroscopy (EIS); subsequently of the tests, the specimens were analyzed by optical microscopy and scanning electron microscopy characterizing the surface morphology. It was observed that the coating presents an increase in its corrosion and wear resistance with the presence of a simulated biological fluid. The samples were characterized via X-ray diffraction. (Author)

  11. Tribological performance evaluation of coated steels with TiNbCN subjected to tribo-chemical wear in Ringers solution

    Energy Technology Data Exchange (ETDEWEB)

    Caballero G, J.; Aperador, W. [Universidad Militar Nueva Granada, Volta Research Group, 101-80 Bogota (Colombia); Caicedo, J. C., E-mail: g.ing.materiales@gmail.com [Universidad del Valle, Tribology Polymers, Powder Metallurgy and Processing of Solid Recycled Research Group, Cali (Colombia)

    2016-11-01

    With the aim of generating solutions against the deterioration of the joint prostheses, it was studied the tribo-corrosive behavior of titanium niobium carbonitride (TiNbCN) deposited on stainless steel AISI 316 LVM using the technique of magnetron sputtering physical vapor deposition. The tests were performed in a balanced saline solution (Ringers solution) which represents the characteristics of the body fluids, using an equipment where the micro-abrasive wear is generated by the contact of micro particles in the system; the micro-abrasion-corrosion mechanism is described by means of the incorporation of an electrochemical cell consisting of three electrodes. Both the substrate and the coating, were subjected to micro-abrasive wear simultaneously with the electrochemical tests of Tafel polarization curves and electrochemical impedance spectroscopy (EIS); subsequently of the tests, the specimens were analyzed by optical microscopy and scanning electron microscopy characterizing the surface morphology. It was observed that the coating presents an increase in its corrosion and wear resistance with the presence of a simulated biological fluid. The samples were characterized via X-ray diffraction. (Author)

  12. EFFECT OF SILICATE ON GRAM STAINING AND VIABILITY OF PNEUMOCOCCI AND OTHER BACTERIA

    Science.gov (United States)

    MacLeod, Colin M.; Roe, Amy S.

    1956-01-01

    Application of silicate solutions to living or heat-killed pneumococci and to certain "viridans" streptococci causes their conversion from a Gram-positive to a Gram-negative state. The original staining properties can be restored by suspending the silicate-treated bacteria in alkaline solutions of various salts but not by simple washing in water. Living pneumococci and the strains of streptococci whose staining properties are similarly affected are killed when suspended in silicate solutions. In other Gram-positive species silicate causes conversion to Gram negativity but restoration to positivity occurs upon washing in water. In a third group of Gram-positive organisms silicate has no effect on the Gram reaction. The viability of organisms in these two groups is unaffected by silicate under the conditions employed. No effect on staining or viability of Gram-negative bacteria has been observed. The effects of silicate on staining and viability are inhibited by nutrient broth or whole serum but not by purified serum albumin. Lecithin, choline, and other substituted ammonium compounds also inhibit the effects of silicate on pneumococci. PMID:13306854

  13. Color stability of CAD/CAM Zirconia ceramics following exposure to acidic and staining drinks

    Science.gov (United States)

    Colombo, Marco; Cavallo, Marco; Miegge, Matteo; Dagna, Alberto; Beltrami, Riccardo; Chiesa, Marco

    2017-01-01

    Background The aim of this in vitro study was to evaluate the color stability of CAD/CAM Zirconia ceramics following exposure to acidic drink (Coca Cola) and after exposure to staining solution (coffee). Material and Methods All the samples were immersed in different staining solutions over a 28-day test period. A colorimetric evaluation according to the CIE L*a*b* system was performed by a blind trained operator at 7, 14, 21, 28 days of the staining process. Shapiro Wilk test and Kruskal-Wallis ANOVA were applied to assess significant differences among restorative materials. Paired t-test was applied to test which CIE L*a*b* parameters significantly changed after immersion in staining solutions. Results One week immersion in acidic drink did not cause a perceivable discoloration for all restorative materials (ΔE < 3.3). Subsequent immersion in coffee affected color stability of all Zirconia samples, even if Kruskal-Wallis ANOVA found significant differences among the various restorative materials. Conclusions The ∆Es of CAD/CAM Zirconia ceramics after immersion in coffee varied among the products, but color integrity is not affected by contact with acidic drinks. Key words:CAD/CAM restorative materials, CIE Lab, Zirconia ceramics. PMID:29302281

  14. Color stability of CAD/CAM Zirconia ceramics following exposure to acidic and staining drinks.

    Science.gov (United States)

    Colombo, Marco; Cavallo, Marco; Miegge, Matteo; Dagna, Alberto; Beltrami, Riccardo; Chiesa, Marco; Poggio, Claudio

    2017-11-01

    The aim of this in vitro study was to evaluate the color stability of CAD/CAM Zirconia ceramics following exposure to acidic drink (Coca Cola) and after exposure to staining solution (coffee). All the samples were immersed in different staining solutions over a 28-day test period. A colorimetric evaluation according to the CIE L*a*b* system was performed by a blind trained operator at 7, 14, 21, 28 days of the staining process. Shapiro Wilk test and Kruskal-Wallis ANOVA were applied to assess significant differences among restorative materials. Paired t-test was applied to test which CIE L*a*b* parameters significantly changed after immersion in staining solutions. One week immersion in acidic drink did not cause a perceivable discoloration for all restorative materials (ΔE < 3.3). Subsequent immersion in coffee affected color stability of all Zirconia samples, even if Kruskal-Wallis ANOVA found significant differences among the various restorative materials. The ∆Es of CAD/CAM Zirconia ceramics after immersion in coffee varied among the products, but color integrity is not affected by contact with acidic drinks. Key words: CAD/CAM restorative materials, CIE Lab, Zirconia ceramics.

  15. Concentration-discharge relationships during an extreme event: Contrasting behavior of solutes and changes to chemical quality of dissolved organic material in the Boulder Creek Watershed during the September 2013 flood: SOLUTE FLUX IN A FLOOD EVENT

    Energy Technology Data Exchange (ETDEWEB)

    Rue, Garrett P. [Institute of Arctic and Alpine Research, University of Colorado, Boulder Colorado USA; Rock, Nathan D. [Institute of Arctic and Alpine Research, University of Colorado, Boulder Colorado USA; Gabor, Rachel S. [Institute of Arctic and Alpine Research, University of Colorado, Boulder Colorado USA; Pitlick, John [Department of Geography, University of Colorado, Boulder Colorado USA; Tfaily, Malak [Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland Washington USA; McKnight, Diane M. [Institute of Arctic and Alpine Research, University of Colorado, Boulder Colorado USA

    2017-07-01

    During the week of September 10-17, 2013, close to 20 inches of rain fell across Boulder County, Colorado, USA. This rainfall represented a 1000-year event that caused massive hillslope erosion, landslides, and mobilization of sediments. The resultant stream flows corresponded to a 100-year flood. For the Boulder Creek Critical Zone Observatory (BC-CZO), this event provided an opportunity to study the effect of extreme rainfall on solute concentration-discharge relationships and biogeochemical catchment processes. We observed base cation and dissolved organic carbon (DOC) concentrations at two sites on Boulder Creek following the recession of peak flow. We also isolated three distinct fractions of dissolved organic matter (DOM) for chemical characterization. At the upper site, which represented the forested mountain catchment, the concentrations of the base cations Ca, Mg and Na were greatest at the peak flood and decreased only slightly, in contrast with DOC and K concentrations, which decreased substantially. At the lower site within urban corridor, all solutes decreased abruptly after the first week of flow recession, with base cation concentrations stabilizing while DOC and K continued to decrease. Additionally, we found significant spatiotemporal trends in the chemical quality of organic matter exported during the flood recession, as measured by fluorescence, 13C-NMR spectroscopy, and FTICR-MS. Similar to the effect of extreme rainfall events in driving landslides and mobilizing sediments, our findings suggest that such events mobilize solutes by the flushing of the deeper layers of the critical zone, and that this flushing regulates terrestrial-aquatic biogeochemical linkages during the flow recession.

  16. Centrifuge-operated specimen staining method and apparatus

    Science.gov (United States)

    Clarke, Mark S. F. (Inventor); Feeback, Daniel L. (Inventor)

    1999-01-01

    A method of staining preselected, mounted specimens of either biological or nonbiological material enclosed within a staining chamber where the liquid staining reagents are applied and removed from the staining chamber using hypergravity as the propelling force. In the preferred embodiment, a spacecraft-operated centrifuge and method of diagnosing biological specimens while in orbit, characterized by hermetically sealing a shell assembly. The assembly contains slide stain apparatus with computer control therefor, the operative effect of which is to overcome microgravity, for example on board an International Space Station.

  17. Nanostructured ZnO thin films by chemical bath deposition in basic aqueous ammonia solutions for photovoltaic applications

    Energy Technology Data Exchange (ETDEWEB)

    Chu, J.B.; Huang, S.M.; Zhang, D.W.; Bian, Z.Q.; Li, X.D.; Sun, Z. [East China Normal University, Engineering Research Center for Nanophotonics and Advanced Instrument, Ministry of Education, Department of Physics, Shanghai (China); Yin, X.J. [Singapore Polytechnic, Advanced Materials Technology Center, Singapore (Singapore)

    2009-06-15

    This paper presents further insights and observations of the chemical bath deposition (CBD) of ZnS thin films using an aqueous medium involving Zn-salt, ammonium sulfate, aqueous ammonia, and thiourea. Results on physical and chemical properties of the grown layers as a function of ammonia concentration are reported. Physical and chemical properties were analyzed using scanning electron microscopy (SEM), X-ray energy dispersive (EDX), and X-ray diffraction (XRD). Rapid growth of nanostructured ZnO films on fluorine-doped SnO{sub 2} (FTO) glass substrates was developed. ZnO films crystallized in a wurtzite hexagonal structure and with a very small quantity of Zn(OH){sub 2} and ZnS phases were obtained for the ammonia concentration ranging from 0.75 to 2.0 M. Flower-like and columnar nanostructured ZnO films were deposited in two ammonia concentration ranges, respectively: one between 0.75 and 1.0 M and the other between 1.4 and 2.0 M. ZnS films were formed with a high ammonia concentration of 3.0 M. The formation mechanisms of ZnO, Zn(OH){sub 2}, and ZnS phases were discussed in the CBD process. The developed technique can be used to directly and rapidly grow nanostructured ZnO film photoanodes. Annealed ZnO nanoflower and columnar nanoparticle films on FTO substrates were used as electrodes to fabricate the dye sensitized solar cells (DSSCs). The DSSC based on ZnO-nanoflower film showed an energy conversion efficiency of 0.84%, which is higher compared to that (0.45%) of the cell being constructed using a photoanode of columnar nanoparticle ZnO film. The results have demonstrated the potential applications of CBD nanostructured ZnO films for photovoltaic cells. (orig.)

  18. Hirschsprung's disease diagnosis: Comparison of immunohistochemical, hematoxilin and eosin staining

    Science.gov (United States)

    Memarzadeh, Mehrdad; Talebi, Ardeshir; Edalaty, Masod; Hosseinpour, Mehrdad; Vahidi, Nasrin

    2009-01-01

    Background: The diagnosis of Hirschsprung's disease (HD) is based on the absence of ganglion cells. In hemotoxilin and eosin (H and E) as well as acetylcholine esterase staining there are limitations in the diagnosis of immature ganglion cells in neonates. Methods: In this prospective study, 54 biopsies taken from suspected HD patients (five mucosal specimens and 49 full thickness specimens) were studied. In the laboratory, after preparing sections of paraffin embedded tissues, H and E staining slides were compared with immunohistochemical (IHC) staining including: S100, NSE, CD117, CD56, Cathepsin D, Vimentin, BCL2, GFAP, Synaptophysin and chromogranin. Results: The study revealed 30 negative (absence of ganglion cells) cases (55.5%), 17 positive cases (31.04%) and seven suspected cases (12.9%) of ganglion cells on the H and E staining. On IHC staining with CD56 and Cathepsin D, all of the 17 positive cases detected through H and E, were confirmed for having ganglion cells and out of 30 cases reported negative on H and E staining, 28(93.3%) were reported negative and two (6.7%) positive by IHC staining. Of the seven suspected cases H and E staining), IHC staining detectedganglion cells only in five slides; two remained negative. Conclusions: IHC staining using CD56 and Cathepsin D improved the accuracy of diagnosis in HD when used in addition to H and E staining technique, especially for negative or suspicious slides. PMID:20671847

  19. Influence of alkaline (PH 8.3-12.0) and saline solutions on chemical, mineralogical and physical properties of two different bentonites - batch experiments at 25 deg. C

    International Nuclear Information System (INIS)

    Heikola, Tiina; Vuorinen, Ulla; Kumpulainen, Sirpa; Kiviranta, Leena; Korkeakoski, Petri

    2012-01-01

    Document available in extended abstract form only. Construction of a spent fuel repository deep in the bedrock will need supporting structures using cement materials. A part of them can be removed before closure but still it is estimated that about 1000 tonnes will remain in the host rock. Degradation of cementitious materials produces leachates of high pH. If such an alkaline plume reaches the bentonite buffer, it may induce mineralogical and chemical changes in bentonite over long term, and further affect the safety functions of the buffer. Laboratory experiments were done with the objective to gain data of possible alterations in mineralogical, chemical and physical properties of bentonites contacted with high-pH saline solutions. Two untreated, high grade, Na- and Ca-bentonites, were used in batch experiments, which were carried out in an anaerobic glove-box at 25±1 deg. C for 554 days. Each bentonite sample (20 g) was leached with approximately 3.8 L of leaching solution, which equals 190 mL/g of bentonite. The bentonites were leached with three types of simulated cement waters (pH 9.7, 11.3 and 12.0) and one saline groundwater simulate (pH 8.3) as a reference. The leaching solutions were 0.3 M, and contained NaCl and CaCl 2 , and trace amounts of SiO 2 , K, Br, Mg and SO 4 . Dissolved oxygen and carbon dioxide were removed from leaching solutions before mixing of bentonite in PC bottles. The samples were placed on a platform shaker in order to allow better contact between bentonite and the leaching solution. The evolution of pH in the samples was followed by measuring the pH-value of each sample in the solution phase approximately twice a week and the solution was renewed when values of two to three consecutive measurements did not change. On average, the leaching solution was renewed once a month. For each renewal of the leaching solution the phases were separated, the reacted solution withdrawn, and the chemical composition analysed. Before analysis the

  20. A Comprehensive Strategy to Evaluate Compatible Stability of Chinese Medicine Injection and Infusion Solutions Based on Chemical Analysis and Bioactivity Assay.

    Science.gov (United States)

    Li, Jian-Ping; Liu, Yang; Guo, Jian-Ming; Shang, Er-Xin; Zhu, Zhen-Hua; Zhu, Kevin Y; Tang, Yu-Ping; Zhao, Bu-Chang; Tang, Zhi-Shu; Duan, Jin-Ao

    2017-01-01

    Stability of traditional Chinese medicine injection (TCMI) is an important issue related with its clinical application. TCMI is composed of multi-components, therefore, when evaluating TCMI stability, several marker compounds cannot represent global components or biological activities of TCMI. Till now, when evaluating TCMI stability, method involving the global components or biological activities has not been reported. In this paper, we established a comprehensive strategy composed of three different methods to evaluate the chemical and biological stability of a typical TCMI, Danhong injection (DHI). UHPLC-TQ/MS was used to analyze the stability of marker compounds (SaA, SaB, RA, DSS, PA, CA, and SG) in DHI, UHPLC-QTOF/MS was used to analyze the stability of global components (MW 80-1000 Da) in DHI, and cell based antioxidant capability assay was used to evaluate the bioactivity of DHI. We applied this strategy to assess the compatible stability of DHI and six infusion solutions (GS, NS, GNS, FI, XI, and DGI), which were commonly used in combination with DHI in clinic. GS was the best infusion solution for DHI, and DGI was the worst one based on marker compounds analysis. Based on global components analysis, XI and DGI were the worst infusion solutions for DHI. And based on bioactivity assay, GS was the best infusion solution for DHI, and XI was the worst one. In conclusion, as evaluated by the established comprehensive strategy, GS was the best infusion solution, however, XI and DGI were the worst infusion solutions for DHI. In the compatibility of DHI and XI or DGI, salvianolic acids in DHI would be degraded, resulting in the reduction of original composition and generation of new components, and leading to the changes of biological activities. This is the essence of instability compatibility of DHI and some infusion solutions. Our study provided references for choosing the reasonable infusion solutions for DHI, which could contribute the improvement of safety

  1. Quantum chemical calculations and spectroscopic measurements of spectroscopic and thermodynamic properties of given uranyl complexes in aqueous solutions with possible environmental and industrial applications

    Directory of Open Access Journals (Sweden)

    Višňak Jakub

    2016-01-01

    Full Text Available A brief introduction into computational methodology and preliminary results for spectroscopic (excitation energies, vibrational frequencies in ground and excited electronic states and thermodynamic (stability constants, standard enthalpies and entropies of complexation reactions properties of some 1:1, 1:2 and 1:3 uranyl sulphato- and selenato- complexes in aqueos solutions will be given. The relativistic effects are included via Effective Core Potential (ECP, electron correlation via (TDDFT/B3LYP (dispersion interaction corrected and solvation is described via explicit inclusion of one hydration sphere beyond the coordinated water molecules. We acknowledge limits of this approximate description – more accurate calculations (ranging from semi-phenomenological two-component spin-orbit coupling up to four-component Dirac-Coulomb-Breit hamiltonian and Molecular Dynamics simulations are in preparation. The computational results are compared with the experimental results from Time-resolved Laser-induced Fluorescence Spectroscopy (TRLFS and UV-VIS spectroscopic studies (including our original experimental research on this topic. In case of the TRLFS and UV-VIS speciation studies, the problem of complex solution spectra decomposition into individual components is ill-conditioned and hints from theoretical chemistry could be very important. Qualitative agreement between our quantum chemical calculations of the spectroscopic properties and experimental data was achieved. Possible applications for geochemical modelling (e.g. safety studies of nuclear waste repositories, modelling of a future mining site and analytical chemical studies (including natural samples are discussed.

  2. [Influence of surface chemical properties and pore structure characteristics of activated carbon on the adsorption of nitrobenzene from aqueous solution].

    Science.gov (United States)

    Liu, Shou-Xin; Chen, Xi; Zhang, Xian-Quan

    2008-05-01

    Commercial activated carbon was treated by HNO3 oxidation and then subsequently heat treated under N2 atmosphere. Effect of surface chemical properties and pore structure on the adsorption performance of nitrobenzene was investigated. N2/77K adsorption isotherm and scanning electron microscopy (SEM) were used to characterize the pore structure and surface morphology of carbon. Boehm titration, Fourier transform infrared spectroscopy (FTIR), the point of zero charge (pH(PZC)) measurement and elemental analysis were used to characterize the surface properties. The results reveal that HNO3 oxidation can modify the surface chemical properties, increase the number of acidic surface oxygen-containing groups and has trivial effect on the pore structure of carbon. Further heat treatment can cause the decomposition of surface oxygen-containing groups, and increase the external surface area and the number of mesopores. Adsorption capacity of nitrobenzene on AC(NO-T), AC(raw) and AC(NO) was 1011.31, 483.09 and 321.54 mg x g(-1), respectively. Larger external surface area and the number of meso-pores, together with the less acid surface oxygen-containing groups were the main reason for the larger adsorption capacity AC(NO-T).

  3. Quantitative phase analysis using the whole-powder-pattern decomposition method. Pt. 1. Solution from knowledge of chemical compositions

    International Nuclear Information System (INIS)

    Toraya, H.; Tusaka, S.

    1995-01-01

    A new procedure for quantitative phase analysis using the whole-powder-pattern decomposition method is proposed. The procedure consists of two steps. In the first, the whole powder patterns of single-component materials are decomposed separately. The refined parameters of integrated intensity, unit cell and profile shape for respective phases are stored in computer data files. In the second step, the whole powder pattern of a mixture sample is fitted, where the parameters refined in the previous step are used to calculate the profile intensity. The integrated intensity parameters are, however, not varied during the least-squares fitting, while the scale factors for the profile intensities of individual phases are adjusted instead. Weight fractions are obtained by solving simultaneous equations, coefficients of which include the scale factors and the mass-absorption coefficients calculated from chemical formulas of respective phases. The procedure can be applied to all mixture samples, including those containing an amorphous material, if single-component samples with known chemical compositions and their approximate unit-cell parameters are provided. The procedure has been tested by using two-to five-component samples, giving average deviations of 1 to 1.5%. Optimum refinement conditions are discussed in connection with the accuracy of the procedure. (orig.)

  4. Use of non-Conventional Material to Remove Cu+2 ions from Aqueous Solutions using Chemical Coagulation

    Directory of Open Access Journals (Sweden)

    Muna Yousif Abdul. Ahad

    2015-05-01

    Full Text Available Coagulation - flocculation are basic chemical engineering method in the treatment of metal-bearing industrial wastewater because it removes colloidal particles, some soluble compounds and very fine solid suspensions initially present in the wastewater by destabilization and formation of flocs. This research was conducted to study the feasibility of using natural coagulant such as okra and mallow and chemical coagulant such as alum for removing Cu and increase the removal efficiency and reduce the turbidity of treated water. Fourier transform Infrared (FTIR was carried out for okra and mallow before and after coagulant to determine their type of functional groups. Carbonyl and hydroxyl functional groups on the surface of okra and mallow were the major groups responsible for coagulation process. By using alum (conventional coagulants, okra and mallow (as a primary coagulant or in combination with the other two primary coagulants and by the jar testing, the optimum pH-value and dose of the coagulants were determined. The results indicated that the optimal pH values were 6.7, 8 and 6 for alum, okra and mallow, respectively. Mathematical modeling show significant results (sig.<0.05 for the % Cu removal (dependent variable with respect to coagulant dose (independent variable for the okra as a primary coagulant, alum with okra and alum with mallow as binary coagulants and alum, okra and mallow as ternary coagulants .

  5. Diluting ferric carboxymaltose in sodium chloride infusion solution (0.9% w/v) in polypropylene bottles and bags: effects on chemical stability.

    Science.gov (United States)

    Philipp, Erik; Braitsch, Michaela; Bichsel, Tobias; Mühlebach, Stefan

    2016-01-01

    This study was designed to assess the physicochemical stability of colloidal ferric carboxymaltose solution (Ferinject) when diluted and stored in polypropylene (PP) bottles and bags for infusion. Two batches of ferric carboxymaltose solution (Ferinject) were diluted (500 mg, 200 mg and 100 mg iron in 100 mL saline) in PP bottles or bags under aseptic conditions. The diluted solutions were stored at 30°C and 75%±5% relative humidity (rH) for 72 h, and samples were withdrawn aseptically at preparation and after 24 h, 48 h and 72 h. Multiple parameters were used to test stability-related measures (pH, total iron and iron (II) content, molecular weight range determination, microbial contamination and particles count ≥10 μm). Overall, Ferinject diluted in 0.9% (w/v) NaCl solution and stored in PP bottles and bags was stable within the specifications for the complex and the acceptability limits set for all assays. In both containers, total iron content remained stable, within 10% of the theoretical iron content, and levels of iron (II) remained far below the threshold of acceptability. All preparations were free from sediments, particle numbers were acceptable and there was no microbial contamination. The molecular weight distribution and polydispersity index were also acceptable. Under the tested experimental conditions, colloidal ferric carboxymaltose solution (Ferinject) diluted in saline in PP infusion bottles or bags demonstrated physical and chemical stability for up to 72 h at 30°C and 75% rH. Because of the lack of additional clinical data, when using ferric carboxymaltose, physicians/pharmacists should refer to the dilution and storing recommendations given in the product's summary of product characteristics.

  6. Simultaneous surface coating and chemical activation of the Li-rich solid solution lithium rechargeable cathode and its improved performance

    International Nuclear Information System (INIS)

    Wu, Yingqiang; Ming, Jun; Zhuo, Linhai; Yu, Yancun; Zhao, Fengyu

    2013-01-01

    In this study, highly dispersive spherical Li-rich solid solution (Li 1.2 Mn 0.54 Ni 0.13 Co 0.13 O 2 ) particles are successfully synthesized by a co-precipitation method. Then these particles are treated with aluminum nitrates ethanol solution at 80 °C. The treatment can extract lithium (Li 2 O) from the Li 2 MnO 3 component in the composite of Li 1.2 Mn 0.54 Ni 0.13 Co 0.13 O 2 . Simultaneously, a thin layer of Al 2 O 3 can be precipitated on the surface of the electrode particles via direct thermal decomposition of aluminum nitrates. After treatment, the first-cycle coulombic efficiency of the electrode increases from 72.1% to 93.6%, meanwhile it shows a superior cycling stability at 100 mA g −1 with a discharge capacity of around 220 mAh g −1 and retention of 92.5% after 100 cycles, which is much higher than that of the pristine electrode (83.2%). Even at a high current density of 2 A g −1 (10 C), the discharge capacity could still achieve and well maintain as high as 140 mAh g −1

  7. Phase-selective staining of metal salt for scanning electron microscopy imaging of block copolymer film

    Energy Technology Data Exchange (ETDEWEB)

    Li, Jing Ze, E-mail: Lijinge@uestc.edu.cn [State Key Laboratory of Electronic Thin Films and Integrated Devices, School of Microelectronic and Solid-state Electronic, University of Electronic Science and Technology of China, Chengdu 610054 (China); State Key Laboratory of Polymer Materials Engineering (Sichuan University), Chengdu 610054 (China); Xinjiang Key Laboratory of Electronic Information Materials and Devices, Urumuqi 830011 (China); Wang, Ying; Hong Wang, Zhi; Mei, Di; Zou, Wei [State Key Laboratory of Electronic Thin Films and Integrated Devices, School of Microelectronic and Solid-state Electronic, University of Electronic Science and Technology of China, Chengdu 610054 (China); Min Chang, Ai [State Key Laboratory of Polymer Materials Engineering (Sichuan University), Chengdu 610054 (China); Wang, Qi [Xinjiang Key Laboratory of Electronic Information Materials and Devices, Urumuqi 830011 (China); Komura, Motonori; Ito, Kaori [Division of Integrated Molecular Engineering, Chemical Resources Laboratory, Tokyo Institute of Technology, Yokohama 226-8503 (Japan); Iyoda, Tomokazu, E-mail: Iyoda.t.aa@m.titech.ac.jp [Division of Integrated Molecular Engineering, Chemical Resources Laboratory, Tokyo Institute of Technology, Yokohama 226-8503 (Japan)

    2010-09-15

    Three metal salts, i.e., AgNO{sub 3}, HAuCl{sub 4}, and KCl, were proposed as novel staining reagents instead of traditional RuO{sub 4} and OsO{sub 4} labeled with expensive price and extreme toxicity for scanning electron microscopy (SEM) imaging of microphase separated block copolymer film. A simple and costless aqueous solution immersion procedure could ensure selective staining of the metal slat in specific phase of the nanostructured copolymer film, leading to a clear phase contrasted SEM image. The heavy metal salt has better staining effect, demonstrating stable and high signal-to-noise SEM image even at an acceleration voltage as high as 30 kV and magnification up to 250,000 times.

  8. Electrostatic control of the coffee stain effect

    Science.gov (United States)

    Wray, Alex; Papageorgiou, Demetrios; Sefiane, Khellil; Matar, Omar

    2013-11-01

    The ``coffee stain effect,'' as first explained by Deegan et al. 1997, has received a great deal of attention amongst modellers and experimentalists in recent years, perhaps due in part to its obvious casual familiarity. However, it maintains interest because of its intriguing reliance on an interplay of a trio of effects: contact line pinning, inhomogeneous mass flux, and resulting capillarity-driven flow. What is more, the effect, and especially its suppression or reversal, find applications in fields as diverse as sample recovery, mass spectroscopy and the printing of Organic LEDs. We examine the motion a nanoparticle-laden droplet deposited on a precursor film, incorporating the effects of capillarity, concentration-dependent rheology, together with a heated substrate and resultant mass flux and Marangoni effects. We allow the substrate to act as an electrode and incorporate a second electrode above the droplet. The potential difference together with a disparity in electrical properties between the two regions results in electrical (Maxwell) stresses at the interface. We show via lubrication theory and via direct numerical simulations that the ring effect typically observed may be suppressed or augmented via appropriate use of electric fields. EPSRC DTG

  9. Time Course of Detection of Human Male DNA from Stained Blood Sample on Various Surfaces by Loop Mediated Isothermal Amplification and Polymerase Chain Reaction

    OpenAIRE

    Panan Kanchanaphum

    2018-01-01

    This study explores determining the sex of humans from blood stains taken from different surfaces and compares the time course of detection with the conventional PCR, Conventional Loop Mediated Isothermal Amplification (LAMP), and LAMP-Lateral Flow Dipstick (LFD). For the DNA templates, 7 male and 7 female blood stained samples were extracted and added to LAMP and PCR reaction solution to amplify the SRY gene. The DNA samples were extracted from the following blood stained materials: cloth, w...

  10. A flow-cytometric gram-staining technique for milk-associated bacteria.

    Science.gov (United States)

    Holm, Claus; Jespersen, Lene

    2003-05-01

    A Gram-staining technique combining staining with two fluorescent stains, Oregon Green-conjugated wheat germ agglutinin (WGA) and hexidium iodide (HI) followed by flow-cytometric detection is described. WGA stains gram-positive bacteria while HI binds to the DNA of all bacteria after permeabilization by EDTA and incubation at 50 degrees C for 15 min. For WGA to bind to gram-positive bacteria, a 3 M potassium chloride solution was found to give the highest fluorescence intensity. A total of 12 strains representing some of the predominant bacterial species in bulk tank milk and mixtures of these were stained and analyzed by flow cytometry. Overall, the staining method showed a clear differentiation between gram-positive and gram-negative bacterial populations. For stationary-stage cultures of seven gram-positive bacteria and five gram-negative bacteria, an average of 99% of the cells were correctly interpreted. The method was only slightly influenced by the growth phase of the bacteria or conditions such as freezing at -18 degrees C for 24 h. For any of these conditions, an average of at least 95% of the cells were correctly interpreted. When stationary-stage cultures were stored at 5 degrees C for 14 days, an average of 86% of the cells were correctly interpreted. The Gram-staining technique was applied to the flow cytometry analysis of bulk tank milk inoculated with Staphylococcus aureus and Escherichia coli. These results demonstrate that the technique is suitable for analyzing milk samples without precultivation.

  11. Inhibition of precipitation of carbonate apatite by trisodium citrate analysed in base of the formation of chemical complexes in growth solution

    Energy Technology Data Exchange (ETDEWEB)

    Prywer, Jolanta, E-mail: jolanta.prywer@p.lodz.pl [Institute of Physics, Lodz University of Technology, ul. Wólczańska 219, 93-005 Łódź (Poland); Olszynski, Marcin [Institute of Physics, Lodz University of Technology, ul. Wólczańska 219, 93-005 Łódź (Poland); Mielniczek-Brzóska, Ewa [Institute of Chemistry, Environment Protection and Biotechnology, Jan Długosz University of Częstochowa, ul. Armii Krajowej 13/15, 42-200 Częstochowa (Poland)

    2015-11-15

    Effect of trisodium citrate on the precipitation of carbonate apatite is studied. The experimental series are performed in the solution of artificial urine. The investigations are related to infectious urinary stones formation as carbonate apatite is one of the main components of this kind of stones. To mimic a real infection in urinary tract the aqueous ammonia solution was added to the solution of artificial urine. The spectrophotometric results demonstrate that trisodium citrate increases induction time with respect to carbonate apatite formation and decreases the efficiency of carbonate apatite precipitation. The inhibitory effect of trisodium citrate on the precipitation of carbonate apatite is explained in base of chemical speciation analysis. Such an analysis demonstrates that the inhibitory effect is mainly related with the fact that trisodium citrate binds Ca{sup 2+} ions and causes the formation of CaCit{sup −} and Ca{sub 10}(PO{sub 4}){sub 6}CO{sub 3} complexes. Trisodium citrate binds Ca{sup 2+} ions in the range of pH from 6 to 9.5 for which carbonate apatite is favored to be formed. - Highlights: • Trisodium citrate (TC) increases induction time of carbonate apatite (CA) formation. • TC decreases the efficiency of CA precipitation. • The inhibitory effect of TC is explained in base of chemical speciation analysis. • The inhibitory effect is mainly related with the fact that TC binds Ca{sup 2+} ions. • TC binds Ca{sup 2+} ions in the range of pH from 6 to 9.5 for which CA is formed.

  12. Effects of intratesticular injection of zinc-based solution in rats in combination with anti-inflammatory and analgesic drugs during chemical sterilization

    Directory of Open Access Journals (Sweden)

    Simone Regina Barros de Macedo

    2018-05-01

    Full Text Available Aim: Chemical sterilization is a non-surgical method of contraception based on compounds injected into the testis to induce infertility. However, these injections can cause discomfort and pain able to impair the recovery of animals after this treatment. The objective of this study was to investigate if anti-inflammatories or pain relievers inhibited the sterilizing effect of zinc gluconate-based solution on the testis. Materials and Methods: Adult rats were treated in groups: G1 (control, G2 (dimethyl sulfoxide + dipyrone; G3 (dipyrone/ zinc; G4 (dipyrone + celecoxib/zinc; G5 (dipyrone + meloxicam/zinc, and G6 (dipyrone + dexamethasone/zinc in a single dose per day during 7 days. Animals were analyzed at 7, 15, and 30 days after treatments. Results: The zinc-induced a widespread testicular degeneration and decreased testosterone levels even in combination with anti-inflammatories or pain relievers. Testis, epididymis, prostate, and seminal vesicle had a weight reduction. The anti-inflammatory effect of dexamethasone interfered in the desired action of zinc gluconate in the 1st 15 days and celecoxib up to 7 days. Conclusion: Meloxicam plus dipyrone did not impair the chemical sterilization based on zinc gluconate, and it can be used to reduce nociceptive effects in animals after chemical sterilization.

  13. MOVPE gallium-nitride nanostructures fabricated on ZnO nanorod templates grown from aqueous chemical solution

    Energy Technology Data Exchange (ETDEWEB)

    Fuendling, Soenke; Li Shunfeng; Postels, Bianca; Al-Suleiman, Mohamed; Wehmann, Hergo-Heinrich; Bakin, Andrey; Waag, Andreas, E-mail: s.fuendling@tu-bs.de [Institut fuer Halbleitertechnik, Technische Universitaet Braunschweig, 38096 Braunschweig (Germany)

    2009-11-15

    Concerning optoelectronic devices fabricated by epitaxial methods, the combination of ZnO and GaN has promising aspects regarding their good optical properties and a relatively good lattice matching between both as compared to other foreign substrates like sapphire or silicon. Moreover ZnO nanopillar arrays may serve as a template for GaN nanopillar fabrication or for high quality GaN layers by lateral overgrowth of the ZnO nanopillars. In this work, we investigate the combination of two very different growth methods - aqueous chemical low temperature growth (ACG) for the ZnO nanopillar templates on silicon substrates and metalorganic vapor phase epitaxy (MOVPE) for the GaN overgrowth - in order to show to which extent the very cost efficient ZnO templates suit the high demands of GaN MOVPE. By a combination of annealing and photoluminescence experiments we show that the properties of the heterostructures change significantly with temperature.

  14. Chemical synthesis of composite HML / PDMcT / PAni and its application as the trhiodan adsorbent in aqueous solutions

    International Nuclear Information System (INIS)

    Girotto, L.G.; Pacheco, I.; Freitas, L.L. de; Oliveira, R.S.; Amaral, F.A. do; Canobre, S.C.

    2016-01-01

    The mixed hydroxide lamellar [Co -Al- Cl] was synthesize by the co- precipitation method constant pH 8. The synthesis composite HML/PDMcT/PAni was carried out via chemical. The DRX composite HML/PDMcT/PAni showed that one amorphicity in the conductor polymer doesn't hid the diffraction peaks characteristic of HML. The MEV micrographs of composite HDL / PDMcT / PAni showed a large number of crystallites compacts with several shapes characteristic to PDMcT and nanofibers of polyaniline indicating an association between the different constituents forming the composite. The results of the adsorption was 98% of the pesticide in the composite HML / PDMcT / PAni , the composite can contribute so significantly to one Thiodon withdrawal in contaminated pesticide waters. (author)

  15. Solute-solvent complex switching dynamics of chloroform between acetone and dimethylsulfoxide-two-dimensional IR chemical exchange spectroscopy.

    Science.gov (United States)

    Kwak, Kyungwon; Rosenfeld, Daniel E; Chung, Jean K; Fayer, Michael D

    2008-11-06

    Hydrogen bonds formed between C-H and various hydrogen bond acceptors play important roles in the structure of proteins and organic crystals, and the mechanisms of C-H bond cleavage reactions. Chloroform, a C-H hydrogen bond donor, can form weak hydrogen-bonded complexes with acetone and with dimethylsulfoxide (DMSO). When chloroform is dissolved in a mixed solvent consisting of acetone and DMSO, both types of hydrogen-bonded complexes exist. The two complexes, chloroform-acetone and chloroform-DMSO, are in equilibrium, and they rapidly interconvert by chloroform exchanging hydrogen bond acceptors. This fast hydrogen bond acceptor substitution reaction is probed using ultrafast two-dimensional infrared (2D-IR) vibrational echo chemical exchange spectroscopy. Deuterated chloroform is used in the experiments, and the 2D-IR spectrum of the C-D stretching mode is measured. The chemical exchange of the chloroform hydrogen bonding partners is tracked by observing the time-dependent growth of off-diagonal peaks in the 2D-IR spectra. The measured substitution rate is 1/30 ps for an acetone molecule to replace a DMSO molecule in a chloroform-DMSO complex and 1/45 ps for a DMSO molecule to replace an acetone molecule in a chloroform-acetone complex. Free chloroform exists in the mixed solvent, and it acts as a reactive intermediate in the substitution reaction, analogous to a SN1 type reaction. From the measured rates and the equilibrium concentrations of acetone and DMSO, the dissociation rates for the chloroform-DMSO and chloroform-acetone complexes are found to be 1/24 ps and 1/5.5 ps, respectively. The difference between the measured rate for the complete substitution reaction and the rate for complex dissociation corresponds to the diffusion limited rate. The estimated diffusion limited rate agrees well with the result from a Smoluchowski treatment of diffusive reactions.

  16. Standard Gibbs free energies of reactions of ozone with free radicals in aqueous solution: quantum-chemical calculations.

    Science.gov (United States)

    Naumov, Sergej; von Sonntag, Clemens

    2011-11-01

    Free radicals are common intermediates in the chemistry of ozone in aqueous solution. Their reactions with ozone have been probed by calculating the standard Gibbs free energies of such reactions using density functional theory (Jaguar 7.6 program). O(2) reacts fast and irreversibly only with simple carbon-centered radicals. In contrast, ozone also reacts irreversibly with conjugated carbon-centered radicals such as bisallylic (hydroxycylohexadienyl) radicals, with conjugated carbon/oxygen-centered radicals such as phenoxyl radicals, and even with nitrogen- oxygen-, sulfur-, and halogen-centered radicals. In these reactions, further ozone-reactive radicals are generated. Chain reactions may destroy ozone without giving rise to products other than O(2). This may be of importance when ozonation is used in pollution control, and reactions of free radicals with ozone have to be taken into account in modeling such processes.

  17. Chemical stability of diphenhydramine hydrochloride from an elixir and lidocaine hydrochloride from a viscous solution when mixed together.

    Science.gov (United States)

    Gupta, Vishnu D

    2006-01-01

    The stability of diphenhydramine hydrochloride (from an elixir) and lidocaine hydrochloride (from a viscous solution) in a mixture (1:1) was studied using a stability-indicating high-peformance liquid chromatographic assay method. The concentrations of the drugs were related directly to peak heights and the percent relative standard deviations based on five injections were 1.4 for diphenhydramine and 1.3 for lidocaine. The products of hydrolysis from the both the drugs and a number of excipients present in the dosage forms did not interfere with the developed assay procedure. The mixture was stable for at least 21 days when stored in amber-colored bottles at room temperature. The pH value of the mixture remained constant, and the physical appearance did not change during the study period.

  18. Physico-chemical investigation of cement carbonation in aqueous solution in equilibrium with calcite and with a controlled CO2 partial pressure at 25 and 50 deg. C

    International Nuclear Information System (INIS)

    Chomat, Laure; Trepy, Nadia; Le Bescop, Patrick; Dauzeres, Alexandre; Monguillon, Corinne

    2012-01-01

    In the framework of radioactive waste geological disposal, structural concretes have to be adapted to underground chemical conditions. For concrete in water saturated medium, it is believed that carbonation will have a major impact on the interaction between concrete and the geological medium. So, to understand the complex degradation of the cement paste in that context, it is interesting to study a simplified system such as degradation in carbonated water solution. This solution must be at equilibrium with a CO 2 partial pressure 30 times higher than the atmospheric pCO 2 , to reproduce underground natural conditions of Callovo-Oxfordian clayey rock of Bure (France). In this study, the behaviour of a new low pH material (CEM I + silica fume + fly ashes) is compared with a CEM I cement paste, both of them being submitted to carbonation in aqueous solution in equilibrium with calcite and with a pCO 2 equal to 1.32 kPa (1.3 10 -2 atm). Two different temperatures, 25 and 50 C, are considered. To realize these experiments, two different original types of devices were developed

  19. Effect of precursor solutions stirring on deep level defects concentration and spatial distribution in low temperature aqueous chemical synthesis of zinc oxide nanorods

    Energy Technology Data Exchange (ETDEWEB)

    Alnoor, Hatim, E-mail: hatim.alnoor@liu.se; Chey, Chan Oeurn; Pozina, Galia; Willander, Magnus; Nur, Omer [Department of Science and Technology (ITN), Campus Norrköping, Linköping University, SE-601 74 Norrköping (Sweden); Liu, Xianjie; Khranovskyy, Volodymyr [Department of Physics, Chemistry and Biology (IFM), Linköping University, SE-583 81 Linköping (Sweden)

    2015-08-15

    Hexagonal c-axis oriented zinc oxide (ZnO) nanorods (NRs) with 120-300 nm diameters are synthesized via the low temperature aqueous chemical route at 80 °C on silver-coated glass substrates. The influence of varying the precursor solutions stirring durations on the concentration and spatial distributions of deep level defects in ZnO NRs is investigated. Room temperature micro-photoluminesnce (μ-PL) spectra were collected for all samples. Cathodoluminescence (CL) spectra of the as-synthesized NRs reveal a significant change in the intensity ratio of the near band edge emission (NBE) to the deep-level emission (DLE) peaks with increasing stirring durations. This is attributed to the variation in the concentration of the oxygen-deficiency with increasing stirring durations as suggested from the X-ray photoelectron spectroscopy analysis. Spatially resolved CL spectra taken along individual NRs revealed that stirring the precursor solutions for relatively short duration (1-3 h), which likely induced high super saturation under thermodynamic equilibrium during the synthesis process, is observed to favor the formation of point defects moving towards the tip of the NRs. In contrary, stirring for longer duration (5-15 h) will induce low super saturation favoring the formation of point defects located at the bottom of the NRs. These findings demonstrate that it is possible to control the concentration and spatial distribution of deep level defects in ZnO NRs by varying the stirring durations of the precursor solutions.

  20. Chemical process research and development in the 21st century: challenges, strategies, and solutions from a pharmaceutical industry perspective.

    Science.gov (United States)

    Federsel, Hans-Jürgen

    2009-05-19

    In process research and development (PR&D), the generation and manipulation of small-molecule drugs ranges from bench-scale (laboratory) chemistry to pilot plant manufacture to commercial production. A broad range of disciplines, including process chemistry (organic synthesis), analytical chemistry, process engineering (mass and heat transfer, unit operations), process safety (chemical risk assessment), regulatory compliance, and plant operation, must be effectively applied. In the critical handover between medicinal chemistry and PR&D, compound production is typically scaled up from a few hundred grams to several kilograms. Can the methodologies applied to the former also satisfy the technical, safety, and scalability aspects that come into play in the latter? Occasionally, the transition might occur smoothly, but more often the situation is the opposite: much work and resources must be invested to design a process that is feasible for manufacturing on pilot scale and, eventually, for commercial production. Authentic examples provide enlightening illustrations of dos and don'ts for developing syntheses designed for round-flask operation into production-scale processes. Factors that are easily underestimated or even neglected in the laboratory, such as method robustness, chemical hazards, safety concerns, environmental impact, availability of starting materials and building blocks in bulk quantities, intellectual property (IP) issues, and the final cost of the product, will come into play and need to be addressed appropriately. The decision on which route will be the best for further development is a crucial event and should come into focus early on the R&D timeline. In addition to scientific and technical concerns, the parameter of speed has come to the forefront in the pharmaceutical arena. Although historically the drug industry has tolerated a total time investment of far more than 10 years from idea to market, the current worldwide paradigm requires a

  1. Evaluation of methods for stain removal in acrylic resin denture teeth: in vitro study

    Directory of Open Access Journals (Sweden)

    Ana Flávia Balestrero CASSIANO

    Full Text Available Abstract Introduction The staining of artificial teeth can be related to the acrylic resin abrasion caused by brushing, resulting in higher deposition of dyes from the beverage, and consequently higher aesthetic damage. Objective The aim of this in vitro study was to evaluate methods for removal of stains from acrylic denture teeth using spectrophotometric analysis. Material and method Artificial teeth were divided into twelve groups (n=10 according to the type of treatment (re-polishing - Re or immersion in Corega Tabs - Sp, staining solutions, coffee (Cf and Coca-Cola® (Cc or water (W and with/without toothbrushing (B. The Sp specimens were submitted to seven immersion cycles (5 min each. The Re specimens were polished with pumice stone followed by Spain white paste. Color differences (ΔE were captured by a spectrophotometer: T0 (baseline, T1 (after brushing/immersion in solutions and T2 (after Re or Sp. Result Statistically significant color change between T1 and T2 (paired T-test; α =.05 was observed for the group CfSp (p=.032; and for the groups BWRe (p=.000, BCfRe (p=.049 and CcRe (p=.042. Higher color changes were observed for the specimens submitted to toothbrushing (ANOVA two way; p<.001. Conclusion It could be concluded that the immersion in sodium perborate (Corega Tabs can be used for removal of coffee stains from denture teeth, and re-polishing for removal of Coca-Cola® stains. Still, toothbrushing produced greater color changes on denture teeth, regardless of the immersion solution.

  2. Chemical-specific screening criteria for interpretation of biomonitoring data for volatile organic compounds (VOCs)--application of steady-state PBPK model solutions.

    Science.gov (United States)

    Aylward, Lesa L; Kirman, Chris R; Blount, Ben C; Hays, Sean M

    2010-10-01

    The National Health and Nutrition Examination Survey (NHANES) generates population-representative biomonitoring data for many chemicals including volatile organic compounds (VOCs) in blood. However, no health or risk-based screening values are available to evaluate these data from a health safety perspective or to use in prioritizing among chemicals for possible risk management actions. We gathered existing risk assessment-based chronic exposure reference values such as reference doses (RfDs), reference concentrations (RfCs), tolerable daily intakes (TDIs), cancer slope factors, etc. and key pharmacokinetic model parameters for 47 VOCs. Using steady-state solutions to a generic physiologically-based pharmacokinetic (PBPK) model structure, we estimated chemical-specific steady-state venous blood concentrations across chemicals associated with unit oral and inhalation exposure rates and with chronic exposure at the identified exposure reference values. The geometric means of the slopes relating modeled steady-state blood concentrations to steady-state exposure to a unit oral dose or unit inhalation concentration among 38 compounds with available pharmacokinetic parameters were 12.0 microg/L per mg/kg-d (geometric standard deviation [GSD] of 3.2) and 3.2 microg/L per mg/m(3) (GSD=1.7), respectively. Chemical-specific blood concentration screening values based on non-cancer reference values for both oral and inhalation exposure range from 0.0005 to 100 microg/L; blood concentrations associated with cancer risk-specific doses at the 1E-05 risk level ranged from 5E-06 to 6E-02 microg/L. The distribution of modeled steady-state blood concentrations associated with unit exposure levels across VOCs may provide a basis for estimating blood concentration screening values for VOCs that lack chemical-specific pharmacokinetic data. The screening blood concentrations presented here provide a tool for risk assessment-based evaluation of population biomonitoring data for VOCs and

  3. Colorimetric sensor for triphosphates and their application as a viable staining agent for prokaryotes and eukaryotes.

    Science.gov (United States)

    Ghosh, Amrita; Shrivastav, Anupama; Jose, D Amilan; Mishra, Sanjiv K; Chandrakanth, C K; Mishra, Sandhya; Das, Amitava

    2008-07-15

    The chromogenic complex 1 x Zn (where 1 is (E)-4-(4-dimethylamino-phenylazo)-N,N-bispyridin-2-ylmethyl-benzenesulfonamide) showed high affinity toward the phosphate ion in tetrabutylammonium phosphate in acetonitrile solution and could preferentially bind to adenosine triphosphate (ATP) in aqueous solution at physiological pH. This binding caused a visual change in color, whereas no such change was noticed with other related anions (adenosine monophosphate, adenosine diphosphate, pyrophosphate, and phosphate) of biological significance. Thus, 1 x Zn could be used as a staining agent for different biological cells through binding to the ATP, generated in situ by the mitochondria (in eukaryotes). For prokaryotes (bacteria) the cell membrane takes care of the cells' energy conversion, since they lack mitochondria. ATP is produced in their unique cell structure on the cell membrane, which is not found in any eukaryotes. These stained cells could be viewed with normal light microscopy. This reagent could even be used for distinguishing the gram-positive and the gram-negative bacteria (prokaryotes). This dye was found to be nonlipophilic in nature and nontoxic to living microbes (eukaryotes and prokaryotes). Further, stained cells were found to grow in their respective media, and this confirmed the maintenance of viability of the microbes even after staining, unlike with many other dyes available commercially.

  4. Efficacy test of a toothpaste in reducing extrinsic dental stain

    Science.gov (United States)

    Agustanti, A.; Ramadhani, S. A.; Adiatman, M.; Rahardjo, A.; Callea, M.; Yavuz, I.; Maharani, D. A.

    2017-08-01

    This clinical trial compared the external dental stain reduction achieved by tested toothpaste versus placebo in adult patients. In this double-blind, parallel, randomised clinical trial, 45 female volunteers with a mean age of 20 years old were included. All study subjects front teeth were topically applicated with Silver Diamine Fluoride (SDF) to create external dental stains. Subjects were randomized into test (n=22) and control (n=23) groups. Toothpastes were used for two days to analyse the effects of removing external stains on the labial surfaces of all anterior teeth. VITA Easyshade Advance 4.0 was used to measure dental extrinsic stains changes. The analysis showed statistically significant efficacy of the tested toothpaste in reducing external dental stain caused by SDF, comparing to the placebo toothpaste, after one and two days of usage. The tested toothpaste was effective in reducing dental stain.

  5. Post-staining electroblotting for efficient and reliable peptide blotting.

    Science.gov (United States)

    Lee, Der-Yen; Chang, Geen-Dong

    2015-01-01

    Post-staining electroblotting has been previously described to transfer Coomassie blue-stained proteins from polyacrylamide gel onto polyvinylidene difluoride (PVDF) membranes. Actually, stained peptides can also be efficiently and reliably transferred. Because of selective staining procedures for peptides and increased retention of stained peptides on the membrane, even peptides with molecular masses less than 2 kDa such as bacitracin and granuliberin R are transferred with satisfactory results. For comparison, post-staining electroblotting is about 16-fold more sensitive than the conventional electroblotting for visualization of insulin on the membrane. Therefore, the peptide blots become practicable and more accessible to further applications, e.g., blot overlay detection or immunoblotting analysis. In addition, the efficiency of peptide transfer is favorable for N-terminal sequence analysis. With this method, peptide blotting can be normalized for further analysis such as blot overlay assay, immunoblotting, and N-terminal sequencing for identification of peptide in crude or partially purified samples.

  6. Gram staining in the diagnosis of acute septic arthritis.

    Science.gov (United States)

    Faraj, A A; Omonbude, O D; Godwin, P

    2002-10-01

    This study aimed at determining the sensitivity and specificity of Gram staining of synovial fluid as a diagnostic tool in acute septic arthritis. A retrospective study was made of 22 patients who had arthroscopic lavage following a provisional diagnosis of acute septic arthritis of the knee joint. Gram stains and cultures of the knee aspirates were compared with the clinical and laboratory parameters, to evaluate their usefulness in diagnosing acute arthritis. All patients who had septic arthritis had pain, swelling and limitation of movement. CRP was elevated in 90% of patients. The incidence of elevated white blood cell count was higher in the group of patients with a positive Gram stain study (60%) as compared to patients with a negative Gram stain study (33%). Gram staining sensitivity was 45%. Its specificity was however 100%. Gram staining is an unreliable tool in early decision making in patients requiring urgent surgical drainage and washout.

  7. Techniques for controlling variability in gram staining of obligate anaerobes.

    Science.gov (United States)

    Johnson, M J; Thatcher, E; Cox, M E

    1995-01-01

    Identification of anaerobes recovered from clinical samples is complicated by the fact that certain gram-positive anaerobes routinely stain gram negative; Peptostreptococcus asaccharolyticus, Eubacterium plautii, Clostridium ramosum, Clostridium symbiosum, and Clostridium clostridiiforme are among the nonconformists with regard to conventional Gram-staining procedures. Accurate Gram staining of American Type Culture Collection strains of these anaerobic bacteria is possible by implementing fixing and staining techniques within a gloveless anaerobic chamber. Under anaerobic conditions, gram-positive staining occurred in all test organisms with "quick" fixing techniques with both absolute methanol and formalin. The results support the hypothesis that, when anaerobic bacteria are exposed to oxygen, a breakdown of the physical integrity of the cell wall occurs, introducing Gram stain variability in gram-positive anaerobes. PMID:7538512

  8. Factors influencing extract of Hibiscus sabdariffa staining of rat testes.

    Science.gov (United States)

    Bassey, R B; Bakare, A A; Peter, A I; Oremosu, A A; Osinubi, A A

    2012-08-01

    Some plant extracts can be used in biology and medicine to reveal or identify cellular components and tissues. We investigated the effects of time and concentration on staining of histological sections of rat testes by an acidified extract of Hibiscus sabdariffa. An ethanolic extract of H. sabdariffa was diluted using 1% acetic acid in 70% ethanol to stain histological sections of testes at concentrations of 0.2, 0.1 and 0.05 g/ml for 5, 10, 15, 30, 45 and 60 min. The sections of testes were stained deep red. The staining efficiency of H. sabdariffa was greater at a high concentration and required less time to achieve optimal staining. H. sabdariffa is a strongly basic dye that can be used for various diagnostic purposes. Staining time and concentration must be considered to achieve optimal results.

  9. Improvement of solar cells performances by surface passivation using porous silicon chemically treated with LiBr solution

    Energy Technology Data Exchange (ETDEWEB)

    Haddadi, Ikbel; Dimassi, Wissem; Bousbih, Rabaa; Hajji, Massoud; Kanzari, M. Ali; Ezzaouia, Hatem [Laboratoire de Photovoltaique, Centre de Recherche et des Technologies de l' Energie, Hammam Lif (Tunisia)

    2011-03-15

    Solar cells need efficient light absorption to achieve high efficiencies. In this paper, we present a study on the immersion effect of porous silicon (PS) in a Lithium Bromide (LiBr) aqueous solution, followed by thermal annealing at 100 C for 30 min under nitrogen atmosphere on solar cells performances. The surface morphology was studied by Atomic Force Microscopy (AFM). All samples were analyzed by Fourier transmission infrared spectroscopy (FTIR) before and after LiBr immersion. Good electrical properties were observed after thermal annealing at 100 C for 30 min under nitrogen atmosphere. The reflection spectra of PS, before and after LiBr treatment, performed in the 300-1200 nm wavelength range, showed an important decrease of the reflectivity by this new treatment. A significant increase of the photoluminescence (PL) intensity was obtained after LiBr treatment. An enhancement of the light beam induced current (LBIC) as well as the internal quantum efficiency (IQE) were shown after LiBr treatment. I-V characteristics, under AM1.5 illumination, were improved owing to the increase of the minority carrier diffusion length (L) and an excellent enhancement of the surface recombination velocity (V{sub s}) (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  10. Physico-chemical Stability of MabThera Drug-product Solution for Subcutaneous Injection under in-use Conditions with Different Administration Materials.

    Science.gov (United States)

    Mueller, Claudia; Dietel, Elke; Heynen, Severin R; Nalenz, Heiko; Goldbach, Pierre; Mahler, Hanns-Christian; Schmidt, Johannes; Grauschopf, Ulla; Schoenhamnmer, Karin

    2015-01-01

    MabThera is an essential component of the standard-of-care regimens in the treatment of non-Hodgkin lymphoma and Chronic Lymphatic Leukemia. MabThera for subcutaneous injection is a novel line extension that has been approved by the European Medicines Agency for the treatment of patients with follicular lymphoma and diffuse large B-cell lymphoma. This study aimed to evaluate in-use stability data of MabThera subcutaneous drug-product solution in single-use syringes for subcutaneous administration according to the European Medicines Agency guideline. The drug-product solution was exposed to material contact surfaces of five different administration setups commonly used in subcutaneous drug delivery. MabThera subcutaneous was transferred under aseptic conditions into polypropylene and polycarbonate syringes and stored for 1, 2, and 4 weeks at 2°C to 8°C followed by 24 hours at 30°C. After storage, subcutaneous administration was simulated and MabThera subcutaneous drug-product solution quality attributes were evaluated by using compendial physico-chemical tests, as well as suitable and validated molecule- and formulation-specific analytical methods. MabThera subcutaneous vials were treated and analyzed in parallel. The physico-chemical results of MabThera subcutaneous in the different setups were comparable to the control for all timepoints. No change in drug-product quality after storage and simulated administration was found compared to the control. However, since single-dose products do not contain preservatives, microbial contamination and growth needs to be avoided and product sterility needs to be ensured. The results showed that MabThera subcutaneous remains compatible and stable, from a physico-chemical perspective, for up to 4 weeks at 2°C to 8°C followed by 24 hours at 30°C with the contact materials tested in this study. In order to avoid and minimize microbial growth, MabThera subcutaneous should be used immediately after removal from the original

  11. Diagnosing periprosthetic infection: false-positive intraoperative Gram stains.

    Science.gov (United States)

    Oethinger, Margret; Warner, Debra K; Schindler, Susan A; Kobayashi, Hideo; Bauer, Thomas W

    2011-04-01

    Intraoperative Gram stains have a reported low sensitivity but high specificity when used to help diagnose periprosthetic infections. In early 2008, we recognized an unexpectedly high frequency of apparent false-positive Gram stains from revision arthroplasties. The purpose of this report is to describe the cause of these false-positive test results. We calculated the sensitivity and specificity of all intraoperative Gram stains submitted from revision arthroplasty cases during a 3-month interval using microbiologic cultures of the same samples as the gold standard. Methods of specimen harvesting, handling, transport, distribution, specimen processing including tissue grinding/macerating, Gram staining, and interpretation were studied. After a test modification, results of specimens were prospectively collected for a second 3-month interval, and the sensitivity and specificity of intraoperative Gram stains were calculated. The retrospective review of 269 Gram stains submitted from revision arthroplasties indicated historic sensitivity and specificity values of 23% and 92%, respectively. Systematic analysis of all steps of the procedure identified Gram-stained but nonviable bacteria in commercial broth reagents used as diluents for maceration of periprosthetic membranes before Gram staining and culture. Polymerase chain reaction and sequencing showed mixed bacterial DNA. Evaluation of 390 specimens after initiating standardized Millipore filtering of diluent fluid revealed a reduced number of positive Gram stains, yielding 9% sensitivity and 99% specificity. Clusters of false-positive Gram stains have been reported in other clinical conditions. They are apparently rare related to diagnosing periprosthetic infections but have severe consequences if used to guide treatment. Even occasional false-positive Gram stains should prompt review of laboratory methods. Our observations implicate dead bacteria in microbiologic reagents as potential sources of false-positive Gram

  12. Near-UV laser treatment of extrinsic dental enamel stains.

    Science.gov (United States)

    Schoenly, J E; Seka, W; Featherstone, J D B; Rechmann, P

    2012-04-01

    The selective ablation of extrinsic dental enamel stains using a 400-nm laser is evaluated at several fluences for completely removing stains with minimal damage to the underlying enamel. A frequency-doubled Ti:sapphire laser (400-nm wavelength, 60-nanosecond pulse duration, 10-Hz repetition rate) was used to treat 10 extracted human teeth with extrinsic enamel staining. Each tooth was irradiated perpendicular to the surface in a back-and-forth motion over a 1-mm length using an ∼300-µm-diam 10th-order super-Gaussian beam with fluences ranging from 0.8 to 6.4 J/cm(2) . Laser triangulation determined stain depth and volume removed by measuring 3D surface images before and after irradiation. Scanning electron microscopy evaluated the surface roughness of enamel following stain removal. Fluorescence spectroscopy measured spectra of unbleached and photobleached stains in the spectral range of 600-800 nm. Extrinsic enamel stains are removed with laser fluences between 0.8 and 6.4 J/cm(2) . Stains removed on sound enamel leave behind a smooth enamel surface. Stain removal in areas with signs of earlier cariogenic acid attacks resulted in isolated and randomly located laser-induced, 50-µm-diam enamel pits. These pits contain 0.5-µm diam, smooth craters indicative of heat transfer from the stain to the enamel and subsequent melting and water droplet ejection. Ablation stalling of enamel stains is typically observed at low fluences (Laser ablation of extrinsic enamel stains at 400 nm is observed to be most efficient above 3 J/cm(2) with minimal damage to the underlying enamel. Unsound underlying enamel is also observed to be selectively removed after irradiation. Copyright © 2012 Wiley Periodicals, Inc.

  13. Adsorption of Procion Blue MX-R dye from aqueous solutions by lignin chemically modified with aluminium and manganese

    International Nuclear Information System (INIS)

    Adebayo, Matthew A.; Prola, Lizie D.T.; Lima, Eder C.; Puchana-Rosero, M.J.; Cataluña, Renato; Saucier, Caroline; Umpierres, Cibele S.; Vaghetti, Julio C.P.; Silva, Leandro G. da; Ruggiero, Reinaldo

    2014-01-01

    Graphical abstract: - Highlights: • Complexes of carboxy-methylated lignin with Al and Mn were used as adsorbents. • The optimum adsorption conditions were achieved at pH 2 and 298 K. • Maximum adsorption capacities are 73.52 mg g −1 (CML-Al) and 55.16 mg g −1 (CML-Mn). • CML-Al could remove ca. 95.83% of dye-contaminated industrial effluents. • CML-Al and CML-Mn are effective for treatment of simulated dye-house effluents. - Abstract: A macromolecule, CML, was obtained by purifying and carboxy-methylating the lignin generated from acid hydrolysis of sugarcane bagasse during bioethanol production from biomass. The CMLs complexed with Al 3+ (CML-Al) and Mn 2+ (CML-Mn) were utilised for the removal of a textile dye, Procion Blue MX-R (PB), from aqueous solutions. CML-Al and CML-Mn were characterised using Fourier transform infrared spectroscopy (FTIR), scanning differential calorimetry (SDC), scanning electron microscopy (SEM) and pH PZC . The established optimum pH and contact time were 2.0 and 5 h, respectively. The kinetic and equilibrium data fit into the general order kinetic model and Liu isotherm model, respectively. The CML-Al and CML-Mn have respective values of maximum adsorption capacities of 73.52 and 55.16 mg g −1 at 298 K. Four cycles of adsorption/desorption experiments were performed attaining regenerations of up to 98.33% (CML-Al) and 98.08% (CML-Mn) from dye-loaded adsorbents, using 50% acetone + 50% of 0.05 mol L −1 NaOH. The CML-Al removed ca. 93.97% while CML-Mn removed ca. 75.91% of simulated dye house effluents

  14. Adsorption of Procion Blue MX-R dye from aqueous solutions by lignin chemically modified with aluminium and manganese

    Energy Technology Data Exchange (ETDEWEB)

    Adebayo, Matthew A. [Institute of Chemistry, Federal University of Rio Grande do Sul (UFRGS), Av. Bento Gonçalves 9500, Postal Box 15003, 91501-970 Porto Alegre, RS (Brazil); Department of Chemical Sciences, Ajayi Crowther University, PMB 1066 Oyo, Oyo State (Nigeria); Prola, Lizie D.T. [Institute of Chemistry, Federal University of Rio Grande do Sul (UFRGS), Av. Bento Gonçalves 9500, Postal Box 15003, 91501-970 Porto Alegre, RS (Brazil); Lima, Eder C., E-mail: eder.lima@ufrgs.br [Institute of Chemistry, Federal University of Rio Grande do Sul (UFRGS), Av. Bento Gonçalves 9500, Postal Box 15003, 91501-970 Porto Alegre, RS (Brazil); Puchana-Rosero, M.J.; Cataluña, Renato; Saucier, Caroline; Umpierres, Cibele S.; Vaghetti, Julio C.P. [Institute of Chemistry, Federal University of Rio Grande do Sul (UFRGS), Av. Bento Gonçalves 9500, Postal Box 15003, 91501-970 Porto Alegre, RS (Brazil); Silva, Leandro G. da; Ruggiero, Reinaldo [Institute of Chemistry, Federal University of Uberlândia (UFU), AV. João Naves de Ávila 2121 block 1D—Campus Santa Mônica, 38400-902 Uberlândia, MG (Brazil)

    2014-03-01

    Graphical abstract: - Highlights: • Complexes of carboxy-methylated lignin with Al and Mn were used as adsorbents. • The optimum adsorption conditions were achieved at pH 2 and 298 K. • Maximum adsorption capacities are 73.52 mg g{sup −1} (CML-Al) and 55.16 mg g{sup −1} (CML-Mn). • CML-Al could remove ca. 95.83% of dye-contaminated industrial effluents. • CML-Al and CML-Mn are effective for treatment of simulated dye-house effluents. - Abstract: A macromolecule, CML, was obtained by purifying and carboxy-methylating the lignin generated from acid hydrolysis of sugarcane bagasse during bioethanol production from biomass. The CMLs complexed with Al{sup 3+} (CML-Al) and Mn{sup 2+} (CML-Mn) were utilised for the removal of a textile dye, Procion Blue MX-R (PB), from aqueous solutions. CML-Al and CML-Mn were characterised using Fourier transform infrared spectroscopy (FTIR), scanning differential calorimetry (SDC), scanning electron microscopy (SEM) and pH{sub PZC}. The established optimum pH and contact time were 2.0 and 5 h, respectively. The kinetic and equilibrium data fit into the general order kinetic model and Liu isotherm model, respectively. The CML-Al and CML-Mn have respective values of maximum adsorption capacities of 73.52 and 55.16 mg g{sup −1} at 298 K. Four cycles of adsorption/desorption experiments were performed attaining regenerations of up to 98.33% (CML-Al) and 98.08% (CML-Mn) from dye-loaded adsorbents, using 50% acetone + 50% of 0.05 mol L{sup −1} NaOH. The CML-Al removed ca. 93.97% while CML-Mn removed ca. 75.91% of simulated dye house effluents.

  15. [Histochemical stains for minerals by hematoxylin-lake method].

    Science.gov (United States)

    Miyagawa, Makoto

    2013-04-01

    The present study was undertaken to establish the experimental animal model by histological staining methods for minerals. After intraperitoneal injections of minerals, precipitates deposited on the surface of the liver. Liver tissues were fixed in paraformaldehyde, embedded in paraffin and cut into thin sections which were used as minerals containing standard section. Several reagents for histological stains and spectrophotometry for minerals were applied in both test-tube experiments and stainings of tissue sections to test for minerals. Hematoxylin-lake was found of capable of staining minerals in tissue. A simple technique used was described for light microscopic detection of minerals.

  16. Utility of Gram staining for diagnosis of Malassezia folliculitis.

    Science.gov (United States)

    Tu, Wei-Ting; Chin, Szu-Ying; Chou, Chia-Lun; Hsu, Che-Yuan; Chen, Yu-Tsung; Liu, Donald; Lee, Woan-Ruoh; Shih, Yi-Hsien

    2018-02-01

    Malassezia folliculitis (MalF) mimics acne vulgaris and bacterial folliculitis in clinical presentations. The role of Gram staining in rapid diagnosis of MalF has not been well studied. In our study, 32 patients were included to investigate the utility of Gram staining for MalF diagnosis. The final diagnoses of MalF were determined according to clinical presentation, pathological result and treatment response to antifungal agents. Our results show that the sensitivity and specificity of Gram staining are 84.6% and 100%, respectively. In conclusion, Gram staining is a rapid, non-invasive, sensitive and specific method for MalF diagnosis. © 2017 Japanese Dermatological Association.

  17. Histopathological evaluation of ocular microsporidiosis by different stains

    Directory of Open Access Journals (Sweden)

    Sharma Savitri

    2006-06-01

    Full Text Available Abstract Background There is limited data on comparing stains in the detection of microsporidia in corneal biopsies. Hence we wanted to evaluate various stains for their ability to detect microsporidia in corneal tissue sections. Methods Four cases diagnosed with microsporidiosis on Hematoxylin and Eosin and Periodic Acid Schiff's stained sections of the corneal button between January 2002 and December 2004, were included. Further sections were prospectively stained with calcofluor white, Gram, Giemsa, Masson's trichrome, acridine orange, Gomori's methenamine silver, Gram's chromotrope and modified acid fast stain. The stained sections were analyzed for the spore characteristics in terms of size, shape, color contrast, cell wall morphology, waist band in cytoplasm and ease of detection. Results All sections showed microsporidial spores as 3 – 5 μm, oval bodies. 1% acid fast, Gram's chromotrope and GMS stains provided a reliable diagnosis of microsporidia as diagnostic waist band could be identified and good contrast helped distinguish the spores from inflammatory debris. Conclusion Considering the ease of performance, cost effectiveness and rapidity of the technique, 1% acid fast stain and Gram's chromotrope stain are ideal for the detection of microsporidia.

  18. Efficacy of in-house fluorescent stain for fungus

    Directory of Open Access Journals (Sweden)

    K. R. L. Surya Kirani

    2017-01-01

    Full Text Available Context: Mycotic infections are gaining importance in the present day medicine, and definite demonstration of fungus is essential for diagnosis. Small numbers of organisms in the smear can be identified by fluorescence microscopy. Calcofluor white (CFW fluorescent stain is a textile brightener mixed with Evans blue. It is expensive and not easily available. Aims: (1 To assess the efficacy of in-house CFW fluorescent stain for fungus in relation to conventional CFW stain, histopathology, and culture. (2 To determine sensitivity, specificity, negative predictive value (NPV, and positive predictive value (PPV with culture as gold standard. Settings and Design: One hundred cases of suspected dermatophytosis and 15 cases of systemic mycosis were included in the study. Subjects and Methods: The local whitener Ranipal is added with Robin blue, another brightener, and was used to stain teased fungal cultures. Skin, hair, and nails require pretreatment with potassium hydroxide (KOH. Biopsy slides require deparaffinization and pretreatment with KOH before staining. Conventional calcofluor stain, histopathology, and culture were done. Statistical Analysis Used: Statistical analysis was performed using sensitivity, specificity, NPV, and PPV. Results: The results are consistently comparable with conventional stain. The sensitivity was 100%, specificity was 93.3%, NPV was 100%, and PPV was 85.7%. It is also cost effective when compared to commercial stains. Conclusions: In-house stain can be used for screening of fungus in direct samples, biopsies as alternative in resource-constrained laboratories.

  19. The effect of γ-ray irradiation on the adsorption properties and chemical stability of AMP/SiO2 towards Cs(I) in HNO3 solution

    International Nuclear Information System (INIS)

    Xiaoxia Zhang; Yan Wu; Yuezhou Wei; Guangxi University, Nanning

    2016-01-01

    Silica based ammonium molybdophosphate (AMP/SiO 2 ) adsorbent was used to remove Cs(I) from HNO 3 solution. The adsorbent with different absorbed dose (0-300 kGy) was characteristed by X-ray power diffraction. The adsorption data against different γ-ray absorbed doses were analyzed by the Langmuir isotherm. The adsorption capacity decreased slightly from 23.22 to 22.37 mg/g with the increase of the absorbed dose. The breakthrough properties of Cs(I) were conducted using column packed with AMP/SiO 2 before and after irradiation. The chemical stability of AMP/SiO 2 at 300 kGy absorbed dose in 3 mol/L (M) HNO 3 was excellent. (author)

  20. ELNES study of chemical solution deposited SrO(SrTiO3)n Ruddlesden-Popper films: Experiment and simulation

    International Nuclear Information System (INIS)

    Riedl, T.; Gemming, T.; Weissbach, T.; Seifert, G.; Gutmann, E.; Zschornak, M.; Meyer, D.C.; Gemming, S.

    2009-01-01

    This article analyzes electron energy-loss near-edge fine structures of the SrO(SrTiO 3 ) n=1 Ruddlesden-Popper system and of the parent compounds SrTiO 3 and SrO by comparison with first principles calculations. For that, the fine structures of chemical solution deposited Ruddlesden-Popper films have been experimentally recorded by means of transmission electron microscopy. Moreover, density of states computations using an all-electron density-functional code have been performed. It is shown that the appearance and shape of the experimental O-K and Ti-L 2,3 fine structure features result from the crystallography-dependent electronic structure of the investigated oxides, which display technologically interesting dielectric as well as lattice-structural properties.