Enhanced Silver Nanoparticle Chemiluminescence Method for the Determination of Gemifloxacin Mesylate using Sequential Injection Analysis

International Nuclear Information System (INIS)

Alarfaj, N.A.; Aly, F.A.; Tamimi, A.A.

2013-01-01

A sequential injection analysis (SIA) with chemiluminescence detection has been proposed for the determination of the antibiotic gemifloxacin mesylate (GFX). The developed method is based on the enhancement effect of silver nanoparticles (Ag NPs) on the chemiluminescence (CL) signal of luminol-potassium ferricyanide reaction in alkaline medium. The introduction of gemifloxacin in this system produced a significant decrease in the CL intensity in presence of (Ag NPs). The optimum conditions for CL emission were investigated. Linear relationship between the decrease in CL intensity and concentration was obtained in the range 0.01-1000 ng mL-1, (r = 0.9997) with detection limit of 2.0 pg mL-1 and quantification limit of 0.01 pg mL-1. The relative standard deviation was 1.3 %. The proposed method was employed for the determination of gemifloxacin in bulk drug, in its pharmaceutical dosage forms and biological fluids such as human serum and urine. The interference of some common additive compounds such as glucose, lactose, starch, talc and magnesium stearate was investigated, and no interference was found from these excipients. The obtained SIA results were statistically compared with those obtained from a reported method and did not show any significant difference at confidence level 95%. (author)

A novel chemiluminescence method for determination of bisphenol Abased on the carbon dot-enhanced HCO3−–H2O2 system

International Nuclear Information System (INIS)

Amjadi, Mohammad; Manzoori, Jamshid L.; Hallaj, Tooba

2015-01-01

A simple and sensitive chemiluminescence (CL) method on the basis of carbon dot (C-dot) enhanced HCO 3 − –H 2 O 2 system, is designed for the determination of bisphenol A (BPA). The very weak CL of the HCO 3 − –H 2 O 2 system is enhanced by a factor of ∼100 in the presence of C-dots. Possible mechanisms that lead to the effect were elucidated by recording fluorescence and CL spectra and studying the effect of some radical scavengers. This enhancement is inhibited by BPA in the concentration range from 1.0 to 100 µg L −1 . This is exploited for its trace determination with a detection limit (3 s) of 0.3 µg L −1 . The established method was applied to the determination of BPA in baby bottle and water samples with satisfactory results. - Highlights: • The effect of carbon dots on HCO 3 − –H 2 O 2 chemiluminescence reaction is studied. • Carbon dots greatly enhance the CL signal of this reaction (∼100 fold). • The new CL system was applied to determination of bisphenol A in real samples

Encapsulation of Hemin in Metal-Organic Frameworks for Catalyzing the Chemiluminescence Reaction of the H2O2-Luminol System and Detecting Glucose in the Neutral Condition.

Science.gov (United States)

Luo, Fenqiang; Lin, Yaolin; Zheng, Liyan; Lin, Xiaomei; Chi, Yuwu

2015-06-03

Novel metal-organic frameworks (MOFs) based solid catalysts have been synthesized by encapsulating Hemin into the HKUST-1 MOF materials. These have been first applied in the chemiluminescence field with outstanding performance. The functionalized MOFs not only maintain an excellent catalytic activity inheriting from Hemin but also can be cyclically utilized as solid mimic peroxidases in the neutral condition. The synthesized Hemin@HKUST-1 composites have been used to develop practical sensors for H2O2 and glucose with wide response ranges and low detection limits. It was envisioned that catalyst-functionalized MOFs for chemiluminescence sensing would have promising applications in green, selective, and sensitive detection of target analytes in the future.

Solid-state chemiluminescence assay for ultrasensitive detection of antimony using on-vial immobilization of CdSe quantum dots combined with liquid–liquid–liquid microextraction

Energy Technology Data Exchange (ETDEWEB)

Costas-Mora, Isabel; Romero, Vanesa; Lavilla, Isela; Bendicho, Carlos, E-mail: bendicho@uvigo.es

2013-07-25

Graphical abstract: -- Highlights: •Solid-state chemiluminescence based on CdSe QDs was developed. •QDs immobilization in a vial was achieved in a simple and fast way. •Antimony detection was achieved by inhibition of the CdSe QDs/H{sub 2}O{sub 2} CL reaction. •LLLME allowed improving the selectivity and sensitivity of the CL assay. •The capping ligand played a critical role in the selectivity of the CL system. -- Abstract: On-vial immobilized CdSe quantum dots (QDs) are applied for the first time as chemiluminescent probes for the detection of trace metal ions. Among 17 metal ions tested, inhibition of the chemiluminescence when CdSe QDs are oxidized by H{sub 2}O{sub 2} was observed for Sb, Se and Cu. Liquid–liquid–liquid microextraction was implemented in order to improve the selectivity and sensitivity of the chemiluminescent assay. Factors influencing both the CdSe QDs/H{sub 2}O{sub 2} chemiluminescent system and microextraction process were optimized for ultrasensitive detection of Sb(III) and total Sb. In order to investigate the mechanism by which Sb ions inhibit the chemiluminescence of the CdSe QDs/H{sub 2}O{sub 2} system, atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), UV–vis absorption and fluorescence measurements were performed. The selection of the appropriate CdSe QDs capping ligand was found to be a critical issue. Immobilization of QDs caused the chemiluminescence signal to be enhanced by a factor of 100 as compared to experiments carried out with QDs dispersed in the bulk aqueous phase. Under optimized conditions, the detection limit was 6 ng L{sup −1} Sb and the repeatability expressed as relative standard deviation (N = 7) was about 1.3%. An enrichment factor of 95 was achieved within only 3 min of microextraction. Several water samples including drinking, spring, and river waters were analyzed. The proposed method was validated against CRM NWTM-27.2 fortified lake water, and a recovery study was

Enhanced chemiluminescence for trazodone trace analysis based on acidic permanganate oxidation in concurrent presence of rhodamine 6G.

Science.gov (United States)

Fujimori, Keiichi; Sakata, Yuta; Moriuchi-Kawakami, Takayo; Shibutani, Yasuhiko

2017-11-01

A new sensitized chemiluminescence method by acidic permanganate oxidation was developed for the sensitive determination of trazodone. A fluorescent dye as used rhodamine 6G to increase a chemiluminescence intensity. Under optimum conditions, the liner range of the calibration curve was obtained for 1-5000 nmol/L. The limit of detection was calculated from 3σ of a blank was 0.23 nmol/L. The coexistent ions and substances had no interference with the chemiluminescence measurement. The chemiluminescence spectra were measured to elucidate a possible mechanism for the system. The present method was satisfactorily used in the determination of the drugs in pharmaceutical samples and animal serums. Copyright © 2017 John Wiley & Sons, Ltd.

Advancing liquid metal reactor technology with nitride fuels

International Nuclear Information System (INIS)

Lyon, W.F.; Baker, R.B.; Leggett, R.D.; Matthews, R.B.

1991-08-01

A review of the use of nitride fuels in liquid metal fast reactors is presented. Past studies indicate that both uranium nitride and uranium/plutonium nitride possess characteristics that may offer enhanced performance, particularly in the area of passive safety. To further quantify these effects, the analysis of a mixed-nitride fuel system utilizing the geometry and power level of the US Advanced Liquid Metal Reactor as a reference is described. 18 refs., 2 figs., 2 tabs

Flow-based determination of methionine in pharmaceutical formulations exploiting TGA-capped CdTe quantum dots for enhancing the luminol-KIO{sub 4} chemiluminescence

Energy Technology Data Exchange (ETDEWEB)

Zhou, Min, E-mail: mzhou8367@sina.com [Key Laboratory of Eco-Environment-Related Polymer Materials, Ministry of Education, Key Laboratory of Polymer Materials of Gansu Province, Key Laboratory of Bioelectrochemistry & Environmental Analysis of Gansu Province, College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou 730070 (China); Wang, Ailian [Key Laboratory of Eco-Environment-Related Polymer Materials, Ministry of Education, Key Laboratory of Polymer Materials of Gansu Province, Key Laboratory of Bioelectrochemistry & Environmental Analysis of Gansu Province, College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou 730070 (China); Jiuquan Enviromental Protection Bureau, Jiuquan 735000 (China); Li, Cong; Luo, Xiaowei; Ma, Yongjun [Key Laboratory of Eco-Environment-Related Polymer Materials, Ministry of Education, Key Laboratory of Polymer Materials of Gansu Province, Key Laboratory of Bioelectrochemistry & Environmental Analysis of Gansu Province, College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou 730070 (China)

2017-03-15

A novel flow-injection chemiluminescence method (FI-CL) was established for the determination of methionine in this paper, based on its strong enhancement on CL intensity of the luminol-KIO{sub 4} system catalyzed by thioglycolic acid-capped CdTe quantum dots in alkaline media. Under the optimized conditions, the relative CL intensity was in proportion to methionine concentration in the range from 1.0×10{sup −8} to 1.0×10{sup −5} g mL{sup −1} with a detection limit of 6.6×10{sup −9} g mL{sup −1} (3σ). The relative standard deviation (RSD) of the CL intensity for 1.0×10{sup −6} g mL{sup −1} standard methionine solution was 0.97% (n=11). The proposed method was successfully applied to determine methionine in commercial pharmaceutical formulations with recoveries between 98.0% and 101.9%. The possible CL mechanism was discussed as well. - Graphical abstract: Methionine in commercial pharmaceutical formulations was determined by flow-injection chemiluminescence and the possible chemiluminescence mechanism was discussed as well.

Zinc oxide nanoparticle-enhanced ultrasensitive chemiluminescence immunoassay for the carcinoma embryonic antigen

International Nuclear Information System (INIS)

Pal, Souvik; Bhand, Sunil

2015-01-01

An ultrasensitive enzyme-linked immunosorbent assay (ELISA) is reported for the determination of carcinoma embryonic antigen (CEA) in human serum. It was realized using a microplate reader using a 384-well plate. Monoclonal antibody (Ab) against CEA (1° Ab) acting as the capture probe was immobilized on zinc oxide nanoparticles (ZnO-NPs) in the form of self-assembled monolayers (SAMs). CEA captured by 1° Ab was quantified using a sandwich ELISA wherein a polyclonal second antibody against CEA (2° Ab) was used for detection and quantified using an HRP-labeled secondary antibody (3° Ab). The ZnO-NPs-CEA capture probe was deposited on the bottom of the wells in order to enhance capture of CEA. A 3-fold enhancement in the chemiluminescence (CL) signal of luminol is found (compared to a conventional ELISA). CEA can be quantified by this method in concentrations as low as 1 pg · mL −1 . The upper limit of detection is 20 ng · mL −1 . The use of ZnO-NPs also imparts improved thermal stability. When stored at 4 °C in phosphate-buffered saline of pH 7.4, the probe displays stability of up to 30 days. (author)

Chemiluminescence emission from irradiated polytetrafluoroethylene (PTFE)

International Nuclear Information System (INIS)

Zhong Xiaoguang; Sun Jiazhen; Yoshii, Fumio; Sasaki, Takashi; Makuuchi, Keizo

2000-01-01

PTFE is well known for its chemical and high temperature resistance and also for its high-energy radiation sensitivity. The present work deals with the radiation-induced emission of chemiluminescence from PTFE film, which is generally thought as a measure of radiation induced oxidation reaction in irradiated polymer. The observation that the much stronger chemiluminescence emission from PTFE than that from other polymeric system indicate the unusual high degree of radiation induced oxidation in PTFE. On the other hand the temperature and atmosphere effect during radiation on emission of chemiluminescence were also reported. (author)

Advances in metal forming expert system for metal forming

CERN Document Server

Hingole, Rahulkumar Shivajirao

2015-01-01

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

Direct current-induced electrogenerated chemiluminescence of hydrated and chelated Tb(III) at aluminum cathodes

International Nuclear Information System (INIS)

Hakansson, M.; Jiang, Q.; Spehar, A.-M.; Suomi, J.; Kotiranta, M.; Kulmala, S.

2005-01-01

Cathodic DC polarization of oxide-covered aluminum produces electrogenerated chemiluminescence from hydrated and chelated Tb(III) ions in aqueous electrolyte solutions. At the moment of cathodic voltage onset, a strong cathodic flash is observed, which is attributed to a tunnel emission of hot electrons into the aqueous electrolyte solution and the successive chemical reactions with the luminophores. However, within a few milliseconds the insulating oxide film is damaged and finally dissolved due to (i) indiffusion of protons or alkali metal ions into the thin oxide film, (ii) subsequent hydrogen evolution at the aluminum/oxide interface and (iii) alkalization of the electrode surface induced by hydrogen evolution reaction. When the alkalization of the electrode surface has proceeded sufficiently, chemiluminescence is generated with increasing intensity. Aluminum metal, short-lived Al(II), Al(I) or atomic hydrogen and its conjugated base form, hydrated electron, can act as highly reducing species in addition to the less energetic heterogeneously transferred electrons from the aluminum electrode. Tb(III) added as a hydrated ion in the solution probably luminesces in the form of Tb(OH) 3 or Tb(OH) 4 - by direct redox reactions of the central ion whereas multidentate aromatic ligand chelated Tb(III) probably luminesces by ligand sensitized chemiluminescence mechanism in which ligand is first excited by one-electron redox reactions, which is followed by intramolecular energy transfer to the central ion which finally emits light

Applications of chemiluminescence to bacterial analysis

Science.gov (United States)

Searle, N. D.

1975-01-01

Luminol chemiluminescence method for detecting bacteria was based on microbial activation of the oxidation of the luminol monoanion by hydrogen peroxide. Elimination of the prior lysing step, previously used in the chemiluminescence technique, was shown to improve considerably the reproducibility and accuracy of the method in addition to simplifying it. An inexpensive, portable photomultiplier detector was used to measure the maximum light intensity produced when the sample is added to the reagent. Studies of cooling tower water show that the luminol chemiluminescence technique can be used to monitor changes in viable cell population both under normal conditions and during chlorine treatment. Good correlation between chemiluminescence and plate counts was also obtained in the analysis of process water used in paper mills. This method showed good potential for monitoring the viable bacteria populations in activated sludge used in waste treatment plants to digest organic matter.

Investigation of RuBPS-Ce(IV) chemiluminescence reaction and its application in determination of two diuretics

Energy Technology Data Exchange (ETDEWEB)

Xi Juan [College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072 (China); Ji Xinghu [College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072 (China); Zhang Shaohong [College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072 (China); Xiang Fan Vocational and Technical College, Xiangfan 441021 (China); Ai Xinping [College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072 (China); He Zhike [College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072 (China)]. E-mail: zhkhe@whu.edu.cn

2005-06-13

The chemiluminescence mechanism of tris-(4,7-diphenyl-1,10-phenanthrolinedisulfonic acid)ruthenium(II) (RuBPS)-Ce(IV) system and the effects of two diuretics, hydrochlorothiazide and furosemide, on its chemiluminescence intensity were investigated in detail. It was found that each of the two diuretics could enhance the chemiluminescence emission intensity of RuBPS-Ce(IV) system, based on which, they were sensitively detected by chemiluminescence analysis, respectively. Under the optimum experimental conditions, the linear range and detection limit of hydrochlorothiazide were 2.5 x 10{sup -3} to 6.0 x 10{sup -1} {mu}g ml{sup -1} and 1.0 x 10{sup -3} {mu}g ml{sup -1}, respectively; those of furosemide were 1.0 x 10{sup -2} to 4.0 {mu}g ml{sup -1} and 8.8 x 10{sup -3} {mu}g ml{sup -1}, respectively. The proposed method has been applied to analyze the pharmaceuticals with satisfied results.

40 CFR 1065.270 - Chemiluminescent detector.

Science.gov (United States)

2010-07-01

... Chemiluminescent detector. (a) Application. You may use a chemiluminescent detector (CLD) to measure NOX concentration in raw or diluted exhaust for batch or continuous sampling. We generally accept a CLD for NOX...) Component requirements. We recommend that you use a CLD that meets the specifications in Table 1 of § 1065...

DNA imaging and quantification using chemi-luminescent probes; Imagerie et quantification d`ADN par chimiluminescence

Energy Technology Data Exchange (ETDEWEB)

Dorner, G; Redjdal, N; Laniece, P; Siebert, R; Tricoire, H; Valentin, L [Groupe I.P.B., Experimental Research Division, Inst. de Physique Nucleaire, Paris-11 Univ., 91 - Orsay (France)

1999-11-01

During this interdisciplinary study we have developed an ultra sensitive and reliable imaging system of DNA labelled by chemiluminescence. Based on a liquid nitrogen cooled CCD, the system achieves sensitivities down to 10 fg/mm{sup 2} labelled DNA over a surface area of 25 x 25 cm{sup 2} with a sub-millimeter resolution. Commercially available chemi-luminescent - and enhancer molecules are compared and their reaction conditions optimized for best signal-to-noise ratios. Double labelling was performed to verify quantification with radioactive probes. (authors) 1 fig.

Rational design for enhancing inflammation-responsive in vivo chemiluminescence via nanophotonic energy relay to near-infrared AIE-active conjugated polymer.

Science.gov (United States)

Seo, Young Hun; Singh, Ajay; Cho, Hong-Jun; Kim, Youngsun; Heo, Jeongyun; Lim, Chang-Keun; Park, Soo Young; Jang, Woo-Dong; Kim, Sehoon

2016-04-01

H2O2-specific peroxalate chemiluminescence is recognized as a potential signal for sensitive in vivo imaging of inflammation but the effect of underlying peroxalate-emitter energetics on its efficiency has rarely been understood. Here we report a simple nanophotonic way of boosting near-infrared chemiluminescence with no need of complicated structural design and synthesis of an energetically favored emitter. The signal enhancement was attained from the construction of a nanoparticle imaging probe (∼26 nm in size) by dense nanointegration of multiple molecules possessing unique photonic features, i.e., i) a peroxalate as a chemical fuel generating electronic excitation energy in response to inflammatory H2O2, ii) a low-bandgap conjugated polymer as a bright near-infrared emitter showing aggregation-induced emission (AIE), and iii) an energy gap-bridging photonic molecule that relays the chemically generated excitation energy to the emitter for its efficient excitation. From static and kinetic spectroscopic studies, a green-emissive BODIPY dye has proven to be an efficient relay molecule to bridge the energy gap between the AIE polymer and the chemically generated excited intermediate of H2O2-reacted peroxalates. The energy-relayed nanointegration of AIE polymer and peroxalate in water showed a 50-times boosted sensing signal compared to their dissolved mixture in THF. Besides the high H2O2 detectability down to 10(-9) M, the boosted chemiluminescence presented a fairly high tissue penetration depth (>12 mm) in an ex vivo condition, which enabled deep imaging of inflammatory H2O2 in a hair-covered mouse model of peritonitis. Copyright © 2016 Elsevier Ltd. All rights reserved.

Comparison of the performance of the borax buffer-based HRP-enhanced reagent and the 'Lumi-Phos 530' chemiluminescence systems in the detection of biotinylated DNA.

Science.gov (United States)

Cercek, B; Roby, K; Siaw, M

1995-01-01

A comparison of two chemiluminescence methods, the borax buffer-based HRP-enhanced reagent and Lumi-Phos 530, applied to the detection of a biotinylated 30-mer DNA slot blotted onto a nylon membrane, is presented. A streptavidin-HRP and streptavidin-ALP mediated detection system was used. The HRP-enhanced system is up to 15-fold greater with respect to the signal/background ratios than the Lumi-Phos 530 system at 0.5 microgram biotinylated DNA with at least a two-fold improvement in detection sensitivity for 0.5 ng biotinylated DNA.

Cathodic electrogenerated chemiluminescence of aromatic Tb(III) chelates at polystyrene-graphite composite electrodes

International Nuclear Information System (INIS)

Salminen, Kalle; Grönroos, Päivi; Tuomi, Sami; Kulmala, Sakari

2017-01-01

Tb(III) chelates exhibit intense hot electron-induced electrogenerated chemiluminescence during cathodic polarization of metal/polystyrene-graphite (M/PG) electrodes in fully aqueous solutions. The M/PG working electrode provides a sensitive means for the determination of aromatic Tb(III) chelates at nanomolar concentration levels with a linear log-log calibration curve spanning more than five orders of magnitude. The charge transport and other properties of these novel electrodes were studied by electrochemiluminescence measurements and cyclic voltammetry. The present composite electrodes can by utilized both under pulse polarization and DC polarization unlike oxide-coated metal electrodes which do not tolerate cathodic DC polarization. The present cost-effective electrodes could be utilized e.g. in immunoassays where polystyrene is extensively used as a solid phase for various bioaffinity assays by using electrochemiluminescent Tb(III) chelates or e.g. Ru(bpy) 3 2+ as labels. - Highlights: • Generation of hydrated electrons at Polystyrene-graphite electrodes. • The insulating polystyrene layer on the outer electrode surface seems necessary. • Hydrated electrons are able to produce chemiluminescence. • Strongest signal and lowest std. dev. achieved at same graphite weight fraction.

Strong enhancement of the chemiluminescence of the Cu(II)-H2O2 system on addition of carbon nitride quantum dots, and its application to the detection of H2O2 and glucose.

Science.gov (United States)

Hallaj, Tooba; Amjadi, Mohammad; Song, Zhenlun; Bagheri, Robabeh

2017-12-19

The authors report that carbon nitride quantum dots (CN QDs) exert a strong enhancing effect on the Cu(II)/H 2 O 2 chemiluminescent system. Chemiluminescence (CL) intensity is enhanced by CN QDs by a factor of ~75, while other carbon nanomaterials have a much weaker effect. The possible mechanism of the effect was evaluated by recording fluorescence and CL spectra and by examining the effect of various radical scavengers. Emitting species was found to be excited-state CN QDs that produce green CL peaking at 515 nm. The new CL system was applied to the sensitive detection of H 2 O 2 and glucose (via glucose oxidase-catalyzed formation of H 2 O 2 ) with detection limits (3σ) of 10 nM for H 2 O 2 and 100 nM for glucose. The probe was employed for glucose determination in human plasma samples with satisfactory results. Graphical abstract The effect of carbon nitride quantum dots (CN QDs) on Cu(II)-H 2 O 2 chemiluminescence reaction was studied and the new CL system was applied for sensitive detection of glucose based on the glucose oxidase (GOx)-catalyzed formation of H 2 O 2 .

Comparative study of β-glucan induced respiratory burst measured by nitroblue tetrazolium assay and real-time luminol-enhanced chemiluminescence assay in common carp (Cyprinus carpio L.).

Science.gov (United States)

Vera-Jimenez, N I; Pietretti, D; Wiegertjes, G F; Nielsen, M E

2013-05-01

The respiratory burst is an important feature of the immune system. The increase in cellular oxygen uptake that marks the initiation of the respiratory burst is followed by the production of reactive oxygen species (ROS) such as superoxide anion and hydrogen peroxide which plays a role in the clearance of pathogens and tissue regeneration processes. Therefore, the respiratory burst and associated ROS constitute important indicators of fish health status. This paper compares two methods for quantitation of ROS produced during the respiratory burst in common carp: the widely used, single-point measurement based on the intracellular reduction of nitroblue tetrazolium (NBT) and a real-time luminol-enhanced assay based on the detection of native chemiluminescence. Both assays allowed for detection of dose-dependent changes in magnitude of the respiratory burst response induced by β-glucans in head kidney cells of carp. However, whereas the NBT assay was shown to detect the production of only superoxide anions, the real-time luminol-enhanced assay could detect the production of both superoxide anions and hydrogen peroxide. Only the chemiluminescence assay could reliably record the production of ROS on a real-time scale at frequent and continual time intervals for time course experiments, providing more detailed information on the respiratory burst response. The real-time chemiluminescence assay was used to measure respiratory burst activity in macrophage and neutrophilic granulocyte-enriched head kidney cell fractions and total head kidney cell suspensions and proved to be a fast, reliable, automated multiwell microplate assay to quantitate fish health status modulated by β-glucans. Copyright © 2013 Elsevier Ltd. All rights reserved.

Capillary electrophoresis microchip coupled with on-line chemiluminescence detection

International Nuclear Information System (INIS)

Su Rongguo; Lin Jinming; Qu Feng; Chen Zhifeng; Gao Yunhua; Yamada, Masaaki

2004-01-01

In the present work, chemiluminescence detection was integrated with capillary electrophoresis microchip. The microchip was designed on the principle of flow-injection chemiluminescence system and capillary electrophoresis. It has three main channels, five reservoirs and a detection cell. As model samples, dopamine and catechol were separated and detected using a permanganate chemiluminescent system on the prepared microchip. The samples were electrokinetically injected into the double-T cross section, separated in the separation channel, and then oxidized by chemiluminescent reagent delivered by a home-made micropump to produce light in the detection cell. The electroosmotic flow could be smoothly coupled with the micropump flow. The detection limits for dopamine and catechol were 20.0 and 10.0 μM, respectively. Successful separation and detection of dopamine and catechol demonstrated the distinct advantages of integration of chemiluminescent detection on a microchip for rapid and sensitive analysis

The Applications of Gold Nanoparticle-Initialed Chemiluminescence in Biomedical Detection

Science.gov (United States)

Liu, Zezhong; Zhao, Furong; Gao, Shandian; Shao, Junjun; Chang, Huiyun

2016-10-01

Chemiluminescence technique as a novel detection method has gained much attention in recent years owning to the merits of high sensitivity, wider linear ranges, and low background signal. Similarly, nanotechnology especially for gold nanoparticles has emerged as detection tools due to their unique physical and chemical properties. Recently, it has become increasingly popular to couple gold nanoparticles with chemiluminescence technique in biological agents' detection. In this review, we describe the superiority of both chemiluminescence and gold nanoparticles and conclude the different applications of gold nanoparticle-initialed chemiluminescence in biomedical detection.

Free radical scavenging activity of coenzyme Q measured by a chemiluminescent assay

International Nuclear Information System (INIS)

Battino, Maurizio; Ferri, Elida; Girotti, Stefano; Lenaz, Giorgio

1991-01-01

Involvement of coenzyme Q (CoQ) in anti-oxydant activities, in addition to its major redox role, has frequently been suggested in recent years. In order to elucidate if CoQ could really be engaged in scavenging free radicals produced endogenously in a biological system, an experimental system was developed in which beef heart mitochondria in the presence of a saturating NADH concentration and of rotenone produce free radicals. The presence of oxygen-reactive forms was easily detected by a luminol-dependent chemiluminescence process. The chemi-luminescence assay showed that short-chain CoQ homologues can act as pro-oxidants, enhancing free radical effects, while exogenous coenzyme Q 10 could scavenge free radicals, especially at very low concentration. In this system, exogenous CoQ 10 was more effective than α-tocopherol at the same concentration in scavenging free radicals. The molecular mechanism that leads to this activity is still unclear, but these results are of biochemical importance because they indicate that CoQ may act as an anti=oxidant in situations mimicking physiopathological conditions. This direct chemiluminescent method is promising for studies of biochemical processes which involve active oxygen species. (author). 24 refs.; 4 figs

An automatic enzyme immunoassay based on a chemiluminescent lateral flow immunosensor.

Science.gov (United States)

Joung, Hyou-Arm; Oh, Young Kyoung; Kim, Min-Gon

2014-03-15

Microfluidic integrated enzyme immunosorbent assay (EIA) sensors are efficient systems for point-of-care testing (POCT). However, such systems are not only relatively expensive but also require a complicated manufacturing process. Therefore, additional fluidic control systems are required for the implementation of EIAs in a lateral flow immunosensor (LFI) strip sensor. In this study, we describe a novel LFI for EIA, the use of which does not require additional steps such as mechanical fluidic control, washing, or injecting. The key concept relies on a delayed-release effect of chemiluminescence substrates (luminol enhancer and hydrogen peroxide generator) by an asymmetric polysulfone membrane (ASPM). When the ASPM was placed between the nitrocellulose (NC) membrane and the substrate pad, substrates encapsulated in the substrate pad were released after 5.3 ± 0.3 min. Using this delayed-release effect, we designed and implemented the chemiluminescent LFI-based automatic EIA system, which sequentially performed the immunoreaction, pH change, substrate release, hydrogen peroxide generation, and chemiluminescent reaction with only 1 sample injection. In a model study, implementation of the sensor was validated by measuring the high sensitivity C-reactive protein (hs-CRP) level in human serum. © 2013 Elsevier B.V. All rights reserved.

A rapid and simple chemiluminescence method for screening levels of inosine and hypoxanthine in non-traumatic chest pain patients.

Science.gov (United States)

Farthing, Don E; Sica, Domenic; Hindle, Michael; Edinboro, Les; Xi, Lei; Gehr, Todd W B; Gehr, Lynne; Farthing, Christine A; Larus, Terri L; Fakhry, Itaf; Karnes, H Thomas

2011-01-01

A rapid and simple chemiluminescence method was developed for detection of inosine and hypoxanthine in human plasma. The method utilized a microplate luminometer with direct injectors to automatically dispense reagents during sample analysis. Enzymatic conversions of inosine to hypoxanthine, followed by hypoxanthine to xanthine to uric acid, generated superoxide anion radicals as a useful metabolic by-product. The free radicals react with Pholasin(®) , a sensitive photoprotein used for chemiluminescence detection, to produce measurable blue-green light. The use of Pholasin(®) and a chemiluminescence signal enhancer, Adjuvant-K™, eliminated the need for plasma clean-up steps prior to analysis. The method used 20 μL of heparinized plasma, with complete analysis of total hypoxanthine levels (inosine is metabolized to hypoxanthine using purine nucleoside phosphorylase) in approximately 3.7 min. The rapid chemiluminescence method demonstrated the capability of differentiating total hypoxanthine levels between healthy individuals, and patients presenting with non-traumatic chest pain and potential acute cardiac ischemia. The results support the potential use of chemiluminescence methodology as a diagnostic tool to rapidly screen for elevated levels of inosine and hypoxanthine in human plasma, potential biomarkers of acute cardiac ischemia. Copyright © 2009 John Wiley & Sons, Ltd.

A decade of advances in metallic fuel

International Nuclear Information System (INIS)

Lahm, C.E.; Pahl, R.G.; Porter, D.L.; Tsai, H.; Seidel, B.R.; Batte, G.L.; Dodds, N.E.; Hofman, G.L.; Walters, L.C.

1991-01-01

Significant advances in the understanding of behavior and performance of metallic fuels to high burnup have been achieved over the past four decades. Metallic fuels were the first fuels for liquid-metal-cooled fast reactors (LMR) but in the late 1960's worldwide interest turned toward ceramic fuels before the full potential of metallic fuel could be achieved. Now metallic fuels are recognized as a preferred viable option with regard to safety, integral fuel cycle, waste minimization and deployment economics. This paper reviews the key advances in the last decade and highlights the behavior and performance features which have demonstrated a much greater potential than previously expected

Effect of the dimetilsulfoxido in the response chemiluminescent and the consumption of oxygen of neutrophils activated human

International Nuclear Information System (INIS)

Garcia, J.

2001-01-01

Dimethylsulfoxide (DMSO), a hydroxyl radical scavenger, exerted a dose dependent inhibition on the luminol and lucigenin-enhanced chemiluminescent responses of human neutrophils activated with soluble and particulate stimulants. DMSO inhibition of the luminol chemiluminescense induced by calcium ionophore A23187 was probably due to OH scavenging, whereas inhibition of the lucigenin chemiluminescence suggested DMSO negatively affects the NADPH-dependent membrane oxidase of neutrophils. In agreement with this, DMSO moderately inhibited O2 consumption in PMN suspensions stimulated with chemotactic peptide and opsonized zymosan-induced luminol chemiluminescense was observed only when added before or in conjunction with stimulants, whereas A23187-induced chemiluminescense was inhibited by DMSO regardless of time of addition. Washing of DMSO-treated PMN resulted in increased luminol enhanced chemiluminescense in response to chemotactic peptide and opsonized zymosan. This is consistent with the idea that DMSO may be interfering with activation of the membrane subunits of the oxidase by translocation and docking of the cytoplasmic, regulatory subunits. These data imply that DMSO inhibits neutrophil chemiluminescense both by OH scavenging and interfering with oxidase activation. Key words:Dimethylsulfoxide, chemiluminescent, luminol, lucigenin,neutrophils [es

Sensitive determination of 4-nitrophenol based on its enhancement of a peroxyoxalate chemiluminescence system containing graphene oxide quantum dots and fluorescein

International Nuclear Information System (INIS)

Chen, Donghua; Peng, Rulin; Zhou, Hong; Liu, Hui

2016-01-01

Graphene oxide quantum dots (GOQD) are capable of enhancing the green chemiluminescence (CL) of the system composed of bis (2,4,6-trichlorophenyl) oxalate, hydrogen peroxide and fluorescein (TCPO/H_2O_2/fluorescein). It was found that 4-nitrophenol (4-NP) causes a further enhancement of the system, and this was exploited to develop a CL detection scheme for 4-NP. The optimum reaction concentrations were established, and under these conditions the calibration plot is linear in the 1.0 to 300 pmol L"−"1 concentration range, with a 0.3 pmol L"−"1 detection limit (at 3σ).We assume that CL enhancement is due to energy transfer from GOQD to fluorescein which is promoted by the interaction of 4-NP with the GOQD. The method was applied to the determination of 4-NP in spiked tap water and river water and gave recoveries between 93.4 and 107.9 %, with relative standard deviations of <4.0 %. (author)

A decade of advances in metallic fuel

International Nuclear Information System (INIS)

Seidel, B.R.; Batte, G.L.; Dodds, N.E.; Hofman, G.L.; Lahm, C.E.; Pahl, R.G.; Porter, D.L.; Tsai, H.; Walters, L.C.

1990-01-01

Significant advances in the understanding of behavior and performance of metallic fuels to high burnup have been achieved over the past four decades. Metallic fuels were the first fuels for liquid-metal-cooled fast reactors (LMR) but in the late 1960s worldwide interest turned toward ceramic fuels before the full potential of metallic fuel could be achieved. Now metallic fuels are recognized as a preferred viable option with regard to safety, integral fuel cycle, waste minimization and deployment economics. This paper reviews the key advances in the last decade and highlights the behavior and performance features which have demonstrated a much greater potential than previously expected. 28 refs., 2 figs., 1 tab

Kinetics and selectivity of permanganate chemiluminescence: a study of hydroxyl and amino disubstituted benzene positional isomers.

Science.gov (United States)

Slezak, Teo; Smith, Zoe M; Adcock, Jacqui L; Hindson, Christopher M; Barnett, Neil W; Nesterenko, Pavel N; Francis, Paul S

2011-11-30

Examination of the chemiluminescence reactions of dihydroxybenzenes, aminophenols and phenylenediamines with acidic potassium permanganate has provided a new understanding of the relationships between analyte structure, reaction conditions, kinetics of the light-producing pathway and emission intensity, with broad implications for this widely utilised chemiluminescence detection system. Using a permanganate reagent prepared in a polyphosphate solution and adjusted to pH 2.5, large differences in the rate of reaction with different positional isomers were observed, with the meta-substituted forms reacting far slower and therefore exhibiting much lower chemiluminescence intensities in flow analysis systems. The preliminary partial reduction of permanganate to form significant concentrations of Mn(III) increased the rate of reaction with all analytes tested, resulting in comparable or (in the case of aminophenol and phenylenediamine) even greater emission intensities for the meta-isomers, demonstrating the opportunity to tune the selectivity of the reagent towards certain classes of compound or even specific positional isomers of the same compound. Using more acidic permanganate reagents, in which polyphosphates are not required, the discrepancy between the chemiluminescence intensities was still observed, but was less prominent due to the generally faster rates of reaction. The enhancement of these chemiluminescence reactions by on-line addition of formic acid or formaldehyde can in part also be attributed to the generation of significant pools of the key Mn(III) precursor to the emitting species. Copyright © 2011 Elsevier B.V. All rights reserved.

Metal-enhanced fluorescence exciplex emission.

Science.gov (United States)

Zhang, Yongxia; Mali, Buddha L; Geddes, Chris D

2012-01-01

In this letter, we report the first observation of metal-enhanced exciplex fluorescence, observed from anthracene in the presence of diethylaniline. Anthracene in the presence of diethylaniline in close proximity to Silver Island Films (SIFs) shows enhanced monomer and exciplex emission as compared to a non-silvered control sample containing no silver nanoparticles. Our findings suggest two complementary methods for the enhancement: (i) surface plasmons can radiate coupled monomer and exciplex fluorescence efficiently, and (ii) enhanced absorption (enhanced electric near-field) further facilitates enhanced emission. Our exciplex studies help us to further understand the complex photophysics of the metal-enhanced fluorescence technology. Copyright © 2011 Elsevier B.V. All rights reserved.

Evaluation of a new serological test for syphilis based on chemiluminescence assay in a tertiary care hospital.

Science.gov (United States)

Tiwari, Aseem K; Pandey, Prashant K; Dara, Ravi C; Rawat, Ganesh S; Raina, Vimarsh; Bhargava, Richa

2015-01-01

Syphilis is a transfusion transmissible infections and it is mandatory to do serological test for syphilis (STS) on all donor blood samples. STS is usually based on detection of antibodies against the cardiolipin-lecithin antigen or against the Treponema-specific antigen. STS with good sensitivity and specificity helps enhance blood safety and consolidation of STS along with other transfusion transmittable infections such as human immunodeficiency virus, hepatitis-C virus, and hepatitis-B virus helps in reducing the errors and enhances efficiency. This study was designed to evaluate the performance of newly introduced VITROS(®) syphilis Treponema pallidum agglutination (TPA) assay based on enhanced chemiluminescence principle for its analytical performance for use as a STS on donor blood samples at a tertiary care health center in National Capital Region, India. A total of 108 random blood units collected from the donors (both voluntary and replacement donors) and 28 known syphilis sero-reactive samples stored at -20°C, were used to evaluate the performance of VITROS(®) syphilis TPA assay based on enhanced chemiluminescence assay on VITROS(®) ECiQ immunodiagnostics system along with its analytical performance in terms of its sensitivity, precision, cross-reactivity and interference studies. VITROS(®) syphilis TPA showed 100% sensitivity and specificity with precision (20 days study) of endogenous interfering substances like free hemoglobin or fats. Performance of the VITROS(®) syphilis TPA assay meets the requirements for its use as STS in blood bank, thus allowing consolidation with other transfusion transmittable infections screening assay on chemiluminescence platform, which is highly valuable for optimizing workflow and efficiency.

Highly luminescent S,N co-doped carbon quantum dots-sensitized chemiluminescence on luminol-H2 O2 system for the determination of ranitidine.

Science.gov (United States)

Chen, Jianqiu; Shu, Juan; Chen, Jiao; Cao, Zhiran; Xiao, An; Yan, Zhengyu

2017-05-01

S,N co-doped carbon quantum dots (N,S-CQDs) with super high quantum yield (79%) were prepared by the hydrothermal method and characterized by transmission electron microscopy, photoluminescence, UV-Vis spectroscopy and Fourier transformed infrared spectroscopy. N,S-CQDs can enhance the chemiluminescence intensity of a luminol-H 2 O 2 system. The possible mechanism of the luminol-H 2 O 2 -(N,S-CQDs) was illustrated by using chemiluminescence, photoluminescence and ultraviolet analysis. Ranitidine can quench the chemiluminescence intensity of a luminol-H 2 O 2 -N,S-CQDs system. So, a novel flow-injection chemiluminescence method was designed to determine ranitidine within a linear range of 0.5-50 μg ml -1 and a detection limit of 0.12 μg ml -1 . The method shows promising application prospects. Copyright © 2016 John Wiley & Sons, Ltd.

Quantum dots as chemiluminescence enhancers tested by sequential injection technique: Comparison of flow and flow-batch conditions

Czech Academy of Sciences Publication Activity Database

Sklenářová, H.; Voráčová, Ivona; Chocholouš, P.; Polášek, M.

2017-01-01

Roč. 184, APR (2017), s. 235-241 ISSN 0022-2313 Institutional support: RVO:68081715 Keywords : quantum dots * chemiluminescence * sequentialinjectionanalysis Subject RIV: CB - Analytical Chemistry, Separation OBOR OECD: Analytical chemistry Impact factor: 2.686, year: 2016

Fluorescence and chemiluminescence behavior of distyrylbenzene bearing two arms of dipicolylaminomethyl groups: Interactions with zinc ion and ATP

Science.gov (United States)

Motoyoshiya, Jiro; Wada, Jun-ya; Itoh, Keiko; Wakabayashi, Kazuaki; Maruyama, Takayuki; Ono, Kazuki; Fukasawa, Kota; Fujimoto, Tetsuya; Akaiwa, Yuji; Nonaka, Eiji

2018-04-01

The absorption and fluorescence spectral study of the distyrylbenzene bearing two arms of the dipicolylaminomethyl groups, the effective ligands for Zn2+, was studied in the presence of Zn2+ and ATP. Upon complexation of the distyrylbenzene with zinc ions in acetonitrile, enhancement of the fluorescence intensity was observed due to inhibition of intramolecular PET (photo-induced electron transfer) quenching, but no effect was found in aqueous media because the equilibrium laid to the free form of the ligands. In contrast, the addition of ATP disodium salt was effective to enhance the fluorescence intensity of the combination of the distyrylbenzne and Zn2+ in aqueous media. This assembly was applied to the peroxyoxalate chemiluminescence system and a significant increase in the intensity was observed, which provides a potential detection for ATP by chemiluminescence.

Graphene-based chemiluminescence resonance energy transfer for homogeneous immunoassay.

Science.gov (United States)

Lee, Joon Seok; Joung, Hyou-Arm; Kim, Min-Gon; Park, Chan Beum

2012-04-24

We report on chemiluminescence resonance energy transfer (CRET) between graphene nanosheets and chemiluminescent donors. In contrast to fluorescence resonance energy transfer, CRET occurs via nonradiative dipole-dipole transfer of energy from a chemiluminescent donor to a suitable acceptor molecule without an external excitation source. We designed a graphene-based CRET platform for homogeneous immunoassay of C-reactive protein (CRP), a key marker for human inflammation and cardiovascular diseases, using a luminol/hydrogen peroxide chemiluminescence (CL) reaction catalyzed by horseradish peroxidase. According to our results, anti-CRP antibody conjugated to graphene nanosheets enabled the capture of CRP at the concentration above 1.6 ng mL(-1). In the CRET platform, graphene played a key role as an energy acceptor, which was more efficient than graphene oxide, while luminol served as a donor to graphene, triggering the CRET phenomenon between luminol and graphene. The graphene-based CRET platform was successfully applied to the detection of CRP in human serum samples in the range observed during acute inflammatory stress.

Reagentless chemiluminescence-based fiber optic sensors for regenerative life support in space

Science.gov (United States)

Atwater, James E.; Akse, James R.; DeHart, Jeffrey; Wheeler, Richard R., Jr.

1995-04-01

The initial feasibility demonstration of a reagentless chemiluminescence based fiber optic sensor technology for use in advanced regenerative life support applications in space and planetary outposts is described. The primary constraints for extraterrestrial deployment of any technology are compatibility with microgravity and hypogravity environments; minimal size, weight, and power consumption; and minimal use of expendables due to the great expense and difficulty inherent to resupply logistics. In the current research, we report the integration of solid state flow through modules for the production of aqueous phase reagents into an integrated system for the detection of important analytes by chemiluminescence, with fiber optic light transmission. By minimizing the need for resupply expendables, the use of solid phase modules makes complex chemical detection schemes practical. For the proof of concept, hydrogen peroxide and glucose were chosen as analytes. The reaction is catalyzed by glucose oxidase, an immobilized enzyme. The aqueous phase chemistry required for sensor operation is implemented using solid phase modules which adjust the pH of the influent stream, catalyze the oxidation of analyte, and provide the controlled addition of the luminophore to the flowing aqueous stream. Precise control of the pH has proven essential for the long-term sustained release of the luminophore. Electrocatalysis is achieved using a controlled potential across gold mesh and gold foil electrodes which undergo periodic polarity reversals. The development and initial characterization of performance of the reagentless fiber optic chemiluminescence sensors are presented in this paper.

Bio- and chemiluminescence imaging in analytical chemistry

International Nuclear Information System (INIS)

Roda, Aldo; Guardigli, Massimo; Pasini, Patrizia; Mirasoli, Mara; Michelini, Elisa; Musiani, Monica

2005-01-01

Bio- and chemiluminescence imaging techniques combine the high sensitivity of bio- and chemiluminescence detection with the ability of current light imaging devices to localize and quantify light emission down to the single-photon level. These techniques have been successfully exploited for the development of sensitive analytical methods relying on the evaluation of the spatial distribution of the light emitted from a target sample. In this paper, we report on recent applications of bio- and chemiluminescence imaging for in vitro and in vivo assays, including: quantitative assays performed in various analytical formats, such as microtiter plates, microarrays and miniaturized analytical devices, used in the pharmaceutical, clinical, diagnostic and environmental fields; luminescence imaging microscopy based on enzymatic, immunohistochemical and in situ hybridization reactions for the localization of metabolites, enzymes, antigens and gene sequences in cells and tissues; whole-body luminescence imaging in live animals for evaluating biological and pathological processes and for pharmacological studies

Microplate-reader method for the rapid analysis of copper in natural waters with chemiluminescence detection

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Axel eDurand

2013-01-01

Full Text Available We have developed a method for the determination of copper in natural waters at nanomolar levels. The use of a microplate-reader minimises sample processing time (~ 25 sec per sample, reagent consumption (~ 120 μL per sample and sample volume (~ 700 μL. Copper is detected by chemiluminescence. This technique is based on the formation of a complex between copper and 1,10-phenanthroline and the subsequent emission of light during the oxidation of the complex by hydrogen peroxide. Samples are acidified to pH 1.7 and then introduced directly into a 24-well plate. Reagents are added during data acquisition via two reagent injectors. When trace metal clean protocols are employed, the reproducibility is generally less then 7% on blanks and the detection limit is 0.7 nM for seawater and 0.4 nM for freshwater. More than 100 samples per hour can be analyzed with this technique, which is simple, robust, and amenable to at-sea analysis. Seawater samples from Storm Bay in Tasmania illustrate the utility of the method for environmental science. Indeed other trace metals for which optical detection methods exist (e.g. chemiluminescence, fluorescence and absorbance could be adapted to the microplate-reader.

Performance analysis of a mixed nitride fuel system for an advanced liquid metal reactor

International Nuclear Information System (INIS)

Lyon, W.F.; Baker, R.B.; Leggett, R.D.

1991-01-01

In this paper, the conceptual development and analysis of a proposed mixed nitride driver and blanket fuel system for a prototypic advanced liquid metal reactor design is performed. As a first step, an intensive literature survey is completed on the development and testing of nitride fuel systems. Based on the results of this survey, prototypic mixed nitride fuel and blanket pins is designed and analyzed using the SIEX computer code. The analysis predicts that the nitride fuel consistently operated at peak temperatures and cladding strain levels that compared quite favorably with competing fuel designs. These results, along with data available in the literature on nitride fuel performance, indicate that a nitride fuel system should offer enhanced capabilities for advanced liquid metal reactors

Performance analysis of a mixed nitride fuel system for an advanced liquid metal reactor

International Nuclear Information System (INIS)

Lyon, W.F.; Baker, R.B.; Leggett, R.D.

1990-11-01

The conceptual development and analysis of a proposed mixed nitride driver and blanket fuel system for a prototypic advanced liquid metal reactor design has been performed. As a first step, an intensive literature survey was completed on the development and testing of nitride fuel systems. Based on the results of this survey, prototypic mixed nitride fuel and blanket pins were designed and analyzed using the SIEX computer code. The analysis predicted that the nitride fuel consistently operated at peak temperatures and cladding strain levels that compared quite favorably with competing fuel designs. These results, along with data available in the literature on nitride fuel performance, indicate that a nitride fuel system should offer enhanced capabilities for advanced liquid metal reactors. 13 refs., 10 figs., 2 tabs

Evaluation of enhanced chemiluminescence enzymeimmunoassay(CLEIA) in the determination of thyrotropin(TSH) using amerlite system

International Nuclear Information System (INIS)

Lee, Chae H.; Kim, Hwan k.; Kim, Jin Gyu

1989-01-01

The determination of thyrotropin(TSH) is useful in diagnosis of thyroid diseases. And the widely-used method for the determination of thyrotropin is radioimmunoassay so far because of its sensitivity. But its radiohazard and relatively short half-life of isotopes necessitates alternative methods. So many novel non-isotopic immunoassays are developed and now replacing RIA in routine laboratory measurements. We evaluated the enhanced chemiluminescence enzymeimmunoassay (Amerlite, Amersham International plc., U.K.) for the determination of serum TSH. We got good precision result with control sera. Within-assay and between-assay precision revealed less than 10%(C.V.) respectively. And comparision with CLEIA to RIA showed good correlation (y=0.648x + 0.170, r=0.978, y=value of CLEIA, x=values of RIA, n=35). We also got good correlation between singletons and duplicates result from 35 patients sera (y=0.967x + 0.0281, r=0.997, y=values of singletons, x=values of duplicates). We concluded that CLEIA is vary reliable and economic method for the determination of human TSH substitutive for RIA because of its precision and unnecessary duplicate measurements. (Author)

Quantum dots as chemiluminescence enhancers tested by sequential injection technique: Comparison of flow and flow-batch conditions

Energy Technology Data Exchange (ETDEWEB)

Sklenářová, Hana, E-mail: sklenarova@faf.cuni.cz [Charles University in Prague, Faculty of Pharmacy in Hradec Králové, Department of Analytical Chemistry, Hradec Králové (Czech Republic); Voráčová, Ivona [Institute of Analytical Chemistry of the CAS, v. v. i., Brno (Czech Republic); Chocholouš, Petr; Polášek, Miroslav [Charles University in Prague, Faculty of Pharmacy in Hradec Králové, Department of Analytical Chemistry, Hradec Králové (Czech Republic)

2017-04-15

The effect of 0.01–100 µmol L{sup −1} Quantum Dots (QDs) with different emission wavelengths (520–640 nm) and different surface modifications (mercaptopropionic, mercaptoundecanoic, thioglycolic acids and mercaptoethylamine) on permanganate-induced and luminol–hydrogen peroxide chemiluminescence (CL) was studied in detail by a sequential injection technique using a spiral detection flow cell and a flow-batch detection cell operated in flow and stop-flow modes. In permanganate CL system no significant enhancement of the CL signal was observed while for the luminol–hydrogen peroxide CL substantial increase (>100% and >90% with the spiral detection cell in flow and stop-flow modes, respectively) was attained for CdTe QDs. Enhancement exceeding 120% was observed for QDs with emissions at 520, 575 and 603 nm (sizes of 2.8 nm, 3.3 nm and 3.6 nm) using the flow-batch detection cell in the stop-flow mode. Pronounced effect was noted for surface modifications while mercaptoethylamine was the most efficient in CL enhancement compared to mercaptopropionic acid the most commonly applied coating. Significant difference between results obtained in flow and flow-batch conditions based on the entire kinetics of the extremely fast CL reaction was discussed. The increase of the CL signal was always accompanied by reduced lifetime of the CL emission thus application of QDs in flow techniques should be always coupled with the study of the CL lifetime.

Metal-enhanced galactic winds. I

International Nuclear Information System (INIS)

Vader, J.P.

1986-01-01

Supernova-driven gas loss during the early evolution of elliptical galaxies is considered as a possible explanation for the correlations among the observed chemical and structural properties of these systems. Mass loss from systems with a chemically homogeneous interstellar medium does not work. It is pointed out that supernova-driven winds are in fact metal-enhanced with respect to the star-forming gas because the metal production of any supernova that drives the wind is directly flushed out of the galaxy. The fraction of the total metal production lost in the wind is thus at least as large as the fraction epsilon(z) of supernovae that power the wind, independent of the total mass loss. As a corollary, the yield of heavy elements that are recycled in the galaxy is reduced by a factor 1 - epsilon(z). Metal-enhanced galactic winds, which can carry away a large fraction of the metal production in spite of a moderate total mass loss, offer a promising explanation for the low metallicities of dwarf elliptical galaxies. 62 references

Simultaneous determination of isoniazid and p-aminosalicylic acid by capillary electrophoresis using chemiluminescence detection.

Science.gov (United States)

Zhang, Xinfeng; Xuan, Yuelan; Sun, Aimin; Lv, Yi; Hou, Xiandeng

2009-01-01

It was found that isoniazid (ISO) or p-aminosalicylic acid (PAS) could enhance the chemiluminescence (CL) emission from Cu (II)-luminol-hydrogen peroxide system, and the increased chemiluminescence signals were proportional to their concentrations, respectively. Based on this phenomenon, a chemiluminescence method coupled to capillary electrophoresis (CE) was established for simultaneous determination of ISO and PAS. The CE conditions including running buffer and running voltage were investigated in detail. The effects of the pH of H(2)O(2) solution and the concentrations of luminol, H(2)O(2) and Cu (II) on the CL signal were also investigated carefully. Under the optimized conditions, the analysis could be accomplished within 10 min, with the limits of detection of 0.3 microg mL(-1) for ISO and 1.1 microg mL(-1) for PAS, corresponding to 7.2 and 26.4 pg per injection (24 nL), respectively. Finally, the method was validated by determining the two analytes in pharmaceutical preparation and spiked human serum samples. The results of pharmaceutical tablet analysis were in good agreement with the labeled amounts. The recoveries for ISO and PAS in human serum were in the range of 92-104% and 90-113%, respectively. Copyright 2008 John Wiley & Sons, Ltd.

Evaluation of a new serological test for syphilis based on chemiluminescence assay in a tertiary care hospital

Directory of Open Access Journals (Sweden)

Aseem K Tiwari

2015-01-01

Full Text Available Context: Syphilis is a transfusion transmissible infections and it is mandatory to do serological test for syphilis (STS on all donor blood samples. STS is usually based on detection of antibodies against the cardiolipin-lecithin antigen or against the Treponema-specific antigen. STS with good sensitivity and specificity helps enhance blood safety and consolidation of STS along with other transfusion transmittable infections such as human immunodeficiency virus, hepatitis-C virus, and hepatitis-B virus helps in reducing the errors and enhances efficiency. Aims: This study was designed to evaluate the performance of newly introduced VITROS ® syphilis Treponema pallidum agglutination (TPA assay based on enhanced chemiluminescence principle for its analytical performance for use as a STS on donor blood samples at a tertiary care health center in National Capital Region, India. Materials and Methods: A total of 108 random blood units collected from the donors (both voluntary and replacement donors and 28 known syphilis sero-reactive samples stored at −20°C, were used to evaluate the performance of VITROS ® syphilis TPA assay based on enhanced chemiluminescence assay on VITROS ® ECiQ immunodiagnostics system along with its analytical performance in terms of its sensitivity, precision, cross-reactivity and interference studies. Results: VITROS ® syphilis TPA showed 100% sensitivity and specificity with precision (20 days study of <10% co-efficient of variation. There was no cross-reactivity with other viral and auto-immune antibodies. No interference was observed from endogenous interfering substances like free hemoglobin or fats. Conclusions: Performance of the VITROS ® syphilis TPA assay meets the requirements for its use as STS in blood bank, thus allowing consolidation with other transfusion transmittable infections screening assay on chemiluminescence platform, which is highly valuable for optimizing workflow and efficiency.

High-performance liquid chromatographic assay of parabens in wash-off cosmetic products and foods using chemiluminescence detection

International Nuclear Information System (INIS)

Zhang Qunlin; Lian Mei; Liu Lijuan; Cui Hua

2005-01-01

A new method for the simultaneous determination of parabens including methylparaben, ethylparaben, propylparaben, and butylparaben by high-performance liquid chromatography (HPLC) coupled with chemiluminescence detection was developed. The procedure was based on the chemiluminescent enhancement by parabens of the cerium(IV)-rhodamine 6G system in the strong sulfuric acid medium. The good separation of parabens was carried out with an isocratic elution using a mixture of methanol and water (60:40, v/v) within 8.5 min. Under the optimized conditions, a linear working range extends three orders of magnitude with the relative standard deviations of intra- and inter-day precision below 4.5%, and the detection limits were 1.9 x 10 -9 , 2.7 x 10 -9 , 3.9 x 10 -9 , and 5.3 x 10 -9 g ml -1 for methylparaben, ethylparaben, propylparaben, and butylparaben, respectively. The chemiluminescence reaction was well compatible with the mobile phase of high-performance liquid chromatography. The proposed method has been successfully applied to the assay of parabens in wash-off cosmetic products and foods with the minimal sample preparation

A High Sensitivity Micro Format Chemiluminescence Enzyme Inhibition Assay for Determination of Hg(II

Directory of Open Access Journals (Sweden)

Kanchanmala Deshpande

2010-06-01

Full Text Available A highly sensitive and specific enzyme inhibition assay based on alcohol oxidase (AlOx and horseradish peroxidase (HRP for determination of mercury Hg(II in water samples has been presented. This article describes the optimization and miniaturization of an enzymatic assay using a chemiluminescence reaction. The analytical performance and detection limit for determination of Hg(II was optimized in 96 well plates and further extended to 384 well plates with a 10-fold reduction in assay volume. Inhibition of the enzyme activity by dissolved Hg(II was found to be linear in the range 5–500 pg.mL−1 with 3% CVin inter-batch assay. Due to miniaturization of assay in 384 well plates, Hg(II was measurable as low as 1 pg.mL−1 within15 min. About 10-fold more specificity of the developed assay for Hg(II analysis was confirmed by challenging with interfering divalent metal ions such as cadmium Cd(II and lead Pb(II. Using the proposed assay we could successfully demonstrate that in a composite mixture of Hg(II, Cd(II and Pb(II, inhibition by each metal ion is significantly enhanced in the presence of the others. Applicability of the proposed assay for the determination of the Hg(II in spiked drinking and sea water resulted in recoveries ranging from 100–110.52%.

Nanoporous metals for advanced energy technologies

CERN Document Server

Ding, Yi

2016-01-01

This book covers the state-of-the-art research in nanoporous metals for potential applications in advanced energy fields, including proton exchange membrane fuel cells, Li batteries (Li ion, Li-S, and Li-O2), and supercapacitors. The related structural design and performance of nanoporous metals as well as possible mechanisms and challenges are fully addressed. The formation mechanisms of nanoporous metals during dealloying, the microstructures of nanoporous metals and characterization methods, as well as miscrostructural regulation of nanoporous metals through alloy design of precursors and surface diffusion control are also covered in detail. This is an ideal book for researchers, engineers, graduate students, and government/industry officers who are in charge of R&D investments and strategy related to energy technologies.

Evaluation of Antibacterial Enrofloxacin in Eggs by Matrix Solid Phase Dispersion-Flow Injection Chemiluminescence

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Xiaocui Duan

2014-01-01

Full Text Available The study based on the chemiluminescence (CL reaction of potassium ferricyanide and luminol in sodium hydroxide medium, enrofloxacin (ENRO could dramatically enhance CL intensities and incorporated with matrix solid-phase dispersion (MSPD technique (Florisil used as dispersant, dichloromethane eluted the target compounds. A simple flow injection chemiluminescence (FL-CL method with MSPD technique for determination of ENRO in eggs was described. Under optimal conditions, the CL intensities were linearly related to ENRO concentration ranging from 4.0×10-8 g.L−1 to 5.0×10-5 g.L−1, with a correlation coefficient of 0.9989 and detection limit of 5.0×10-9 g.L−1. The relative standard deviation was 3.6% at an ENRO concentration of 2.0×10-6 g.L−1. Our testing technique can help ensure food safety, and thus, protect public health.

Ultrasensitive chemiluminescence of tetracyclines in the presence of MCLA

Energy Technology Data Exchange (ETDEWEB)

Zeng, Wangsheng; Zhu, Chenyao [School of Public Health, Nanchang University, Nanchang 330006 (China); Liu, Hongcheng [Institute of Quality Standard and Testing Technology, Yunnan Academy of Agriculture Science, 650223 Kunming (China); Liu, Jing; Cai, Hongping [School of Public Health, Nanchang University, Nanchang 330006 (China); Cheng, Xianglei, E-mail: chengxlsd@163.com [School of Public Health, Nanchang University, Nanchang 330006 (China); Wei, Lijun, E-mail: weilj7681@163.com [School of Public Health, Nanchang University, Nanchang 330006 (China)

2017-06-15

In this article, five tetracyclines (TCs) showed ultrasensitive chemiluminescence (CL) based on the novel CL system of methoxylated Cypridina luciferin analogues (MCLA) and Ce(IV). It was found that the CL intensity of MCLA-Ce(IV) system was enhanced 30 times by adding 10 pmol chlortetracycline. Mechanisms of MCLA-Ce(IV)-TCs were investigated by CL spectra, radical scavengers and UV spectra. The results indicated that singlet oxygen, resulting from the reaction between Ce(IV) and TCs, was involved in the enhancement of CL phenomenon. This CL system coupling with flow injection analysis was developed for the determination of five common TCs. Linear ranged from 100 fmol to 20 pmol (r>0.999) with limit of detection of 20 to 50 fmol (S/N=3). The sensitivity of the present method is comparable to that of UPLC-MS/MS detection for TCs.

Recent advances in chemiluminescence detection coupled with capillary electrophoresis and microchip capillary electrophoresis.

Science.gov (United States)

Liu, Yuxuan; Huang, Xiangyi; Ren, Jicun

2016-01-01

CE is an ideal analytical method for extremely volume-limited biological microenvironments. However, the small injection volume makes it a challenge to achieve highly sensitive detection. Chemiluminescence (CL) detection is characterized by providing low background with excellent sensitivity because of requiring no light source. The coupling of CL with CE and MCE has become a powerful analytical method. So far, this method has been widely applied to chemical analysis, bioassay, drug analysis, and environment analysis. In this review, we first introduce some developments for CE-CL and MCE-CL systems, and then put the emphasis on the applications in the last 10 years. Finally, we discuss the future prospects. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Luminol Chemiluminescence Catalyzed by Silver Nanoparticles for the Sensitive Determination of Penicillamine

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Fakhr Eldin O. Suliman

2018-01-01

Full Text Available A sequential injection method for the determination of penicillamine (PA was developed based on quenching the chemiluminescence generated by oxidation of luminol by hydrogen peroxide in presence of silver nanoparticles (AgNPs. The chemiluminescence (CL of the reaction was found to greatly enhance in presence of AgNPs due to the increased catalyst surface area. The method was sensitive and found suitable for analysis of penicillamine in pharmaceutical preparations. Linear calibration curve is obtained in the range 0.2-1.0 mg mL-1 with a relative standard deviation less than 2%. A recovery percent of 102.3 ±0.2 was obtained with the tablets matrix indicating reasonable selectivity of the method for PA in tablets. The mechanism of quenching of the CL reaction was investigated by UV-Visible spectroscopy and transmission electron microscopy as well as by theoretical calculations using DFT-B3LYP method. The covalent attachment of PA to the AgNPs triggers aggregation of the particles thereby diminishing the surface significantly. The method was applied for the assay of PA in pharmaceutical preparations.

Advances in bioleaching for recovery of metals and bioremediation of fuel ash and sewage sludge.

Science.gov (United States)

Gu, Tingyue; Rastegar, Seyed Omid; Mousavi, Seyyed Mohammad; Li, Ming; Zhou, Minghua

2018-08-01

Bioleaching has been successfully used in commercial metal mining for decades. It uses microbes to biosolubilize metal-containing inorganic compounds such as metal oxides and sulfides. There is a growing interest in using bioleaching for bioremediation of solid wastes by removing heavy metals from ash and sewage sludge. This review presents the state of the art in bioleaching research for recovery of metals and bioremediation of solid wastes. Various process parameters such as reaction time, pH, temperature, mass transfer rate, nutrient requirement, pulp density and particle size are discussed. Selections of more effective microbes are assessed. Pretreatment methods that enhance bioleaching are also discussed. Critical issues in bioreactor scale-up are analyzed. The potential impact of advances in biofilm and microbiome is explained. Copyright © 2018 Elsevier Ltd. All rights reserved.

Observation of vapor pressure enhancement of rare-earth metal-halide salts in the temperature range relevant to metal-halide lamps

Energy Technology Data Exchange (ETDEWEB)

Curry, J. J.; Henins, A.; Hardis, J. E. [National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States); Estupinan, E. G. [Osram Sylvania Inc., Beverly, Massachusetts 01915 (United States); Lapatovich, W. P. [Independent Consultant, 51 Pye Brook Lane, Boxford, Massachusetts 01921 (United States); Shastri, S. D. [Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439 (United States)

2012-02-20

Total vapor-phase densities of Dy in equilibrium with a DyI{sub 3}/InI condensate and Tm in equilibrium with a TmI{sub 3}/TlI condensate have been measured for temperatures between 900 K and 1400 K. The measurements show strong enhancements in rare-earth vapor densities compared to vapors in equilibrium with the pure rare-earth metal-halides. The measurements were made with x-ray induced fluorescence on the sector 1-ID beam line at the Advanced Photon Source. The temperature range and salt mixtures are relevant to the operation of metal-halide high-intensity discharge lamps.

Chemiluminescence behavior based on oxidation reaction of rhodamine B with cerium(IV) in sulfuric acid medium

International Nuclear Information System (INIS)

Ma Yongjun; Jin Xiaoyong; Zhou Min; Zhang Ziyu; Teng Xiulan; Chen Hui

2003-01-01

The chemiluminescence (CL) of the rhodamine B (RhB)-cerium(IV) system was investigated by flow-injection. Rhodamine B was suggested to be a suitable chemiluminescent reagent in acidic conditions. When the concentration of rhodamine B was 100 mg l -1 and cerium sulfate was 1.6 mmol l -1 in sulfuric acid, the chemiluminescent intensity was found to be highest by using 0.3 mol l -1 sulfuric acid as a carrier solution. The particular chemiluminescent system could tolerate such distinct acidic environments that it was utilized for detecting many compounds that are stable in acidic solutions. Furthermore, by virtue of IR, UV-Vis and luminescence spectroscopic measurements, the chemiluminescent behavior of rhodamine B was studied and a possible mechanism for this chemiluminescent reaction was proposed. The emitter was affirmed to be a radical species due to one of the oxidation products of RhB; the chemiluminescent emissive wavelength was about 425 nm

Chemiluminescence behavior based on oxidation reaction of rhodamine B with cerium(IV) in sulfuric acid medium

Energy Technology Data Exchange (ETDEWEB)

Ma Yongjun; Jin Xiaoyong; Zhou Min; Zhang Ziyu; Teng Xiulan; Chen Hui

2003-08-18

The chemiluminescence (CL) of the rhodamine B (RhB)-cerium(IV) system was investigated by flow-injection. Rhodamine B was suggested to be a suitable chemiluminescent reagent in acidic conditions. When the concentration of rhodamine B was 100 mg l{sup -1} and cerium sulfate was 1.6 mmol l{sup -1} in sulfuric acid, the chemiluminescent intensity was found to be highest by using 0.3 mol l{sup -1} sulfuric acid as a carrier solution. The particular chemiluminescent system could tolerate such distinct acidic environments that it was utilized for detecting many compounds that are stable in acidic solutions. Furthermore, by virtue of IR, UV-Vis and luminescence spectroscopic measurements, the chemiluminescent behavior of rhodamine B was studied and a possible mechanism for this chemiluminescent reaction was proposed. The emitter was affirmed to be a radical species due to one of the oxidation products of RhB; the chemiluminescent emissive wavelength was about 425 nm.

Chemiluminescence of creatinine/H2O2/Co(2+) and its application for selective creatinine detection.

Science.gov (United States)

Hanif, Saima; John, Peter; Gao, Wenyue; Saqib, Muhammad; Qi, Liming; Xu, Guobao

2016-01-15

Creatinine is an important biomarker in clinical diagnosis and biomonitoring programs as well as urinary metabolomic/metabonomics research. Current methods are either nonselective, time consuming or require heavy and expensive instruments. In this study, chemiluminescence of creatinine with hydrogen peroxide has been reported for the first time, and its chemiluminescence is remarkably enhanced in the presence of cobalt ions. By utilizing these phenomena, we have developed a sensitive and selective chemiluminescence method for creatinine determination by coupling with flow injection analysis. The calibration curve is linear in the range of 1×10(-7)-3×10(-5)mol/L with a limit of detection (S/N=3) of 7.2×10(-8)mol/L, which is adequate for detecting creatinine in the clinically accepted range. The relative standard deviation for seven measurements of 3×10(-5)mol/L creatinine is 1.2%. The chemiluminescence method was then utilized to detect creatinine in human urine samples after simple dilution with water. It takes less than 1min each measurement and the recoveries for spiked urine samples were 100-103%. The interference study demonstrates that some common species in urine, such as amino acids, ascorbic acid and creatine, have negligible effects on creatinine detection. The present method does not use expensive instruments, enzymes and separation technique. This method has the advantages of sensitivity, selectivity, simplicity, rapidity, and low cost. It holds great promise for basic or comprehensive metabolic panel, drug screening, anti-dopping, and urinary metabolomic/metabonomics research. Copyright © 2015 Elsevier B.V. All rights reserved.

FEATURES OF CHEMILUMINESCENT ACTIVITY OF NEUTROPHILIC GRANULOCYTES IN PATIENTS WITH CHRONIC GASTRITIS, CHRONIC ATROPHIC GASTRITIS AND GASTRIC CANCER

Directory of Open Access Journals (Sweden)

O. V. Smirnova

2017-01-01

Full Text Available Chronic gastritis is the most common disease of gastro-intestinal tract. Precancerous potential is among most important epidemiological features of chronic gastritis. Immune system plays a distinct role in transformation from precancerous state to malignancy. In this context, the aim of our work was a study of spontaneous and induced chemiluminescence activity of neutrophilic granulocytes in patients with chronic superficial gastritis, chronic atrophic gastritis and gastric cancer. The work presents results of comprehensive laboratory examination of patients with chronic gastritis (CG (a total of 85 persons. 25 patients with chronic atrophic gastritis (CAG, and 50 patients with gastric cancer (GC at the age of 19 to 70 years were enrolled. Control group included 115 healthy donors without gastrointestinal complaints at the age of 19 to 67 years. The study was performed with venous blood samples taken from cubital vein into Vacutainer tubes with sodium heparin (5 U/mL prior to starting any pathogenic treatment. Evaluation of spontaneous and induced chemiluminescence was performed for 90 minutes at a 36-channel “CL 3606” chemiluminescence analyzer (Russia. In our study, patients with gastric cancer showed clear unidirectional changes in chemiluminescent activity of neutrophilic granulocytes (NG. When measuring spontaneous and induced NG chemiluminescence, we diagnosed a decreased phagocytic activity characterized by prolonged time-to-peak and area under the curve for spontaneous and induced CL, thus presuming longer activation time required in cases of reduced phagocytic function. The NG activity in patients with chronic gastritis is not impaired, but, similar changes of time-to-peak and area under were detected. Chemiluminescent activity of NG is increased in the group of CAG patients, and, considering similar changes in activation time and area under the curve, NG also produce greater amount of reactive oxygen species. Thus, for all H

Chemiluminescence immunoassay for prostate-specific antigen

International Nuclear Information System (INIS)

Zhang Xuefeng; Liu Yibing; Jia Juanjuan; Xu Wenge; Li Ziying; Chen Yongli; Han Shiquan

2008-01-01

The chemiluminescence immunoassay (CLIA) for serum total prostate-specific antigen (T-PSA) was developed. The reaction of luminol with hydrogen peroxide was introduced into this chemiluminescence system. The detection limit is established as 0.12 μg/L (n=10, mean of zero standard + 2SD) and the analytical recovery of PSA is 83.8%-118.7%. The intra-assay and inter-assay CVs vary from 4.4%-5.0% and 6.2%-11.7%, respectively. The experimental correlation coefficient of dilution is found to be 0.999. Compared with immunoradiometric assay (IRMA) kits, the correlative equation is y=1.07x+0.68, and correlation coefficient r=0.97. The standard range for the method is 1.5-80 μg/L, and it presents good linearity. (authors)

A Novel Technique for Generating and Observing Chemiluminescence in a Biological Setting

KAUST Repository

Bü chel, Gabriel E.; Carney, Brandon; Tang, Jun; Zeglis, Brian M.; Eppinger, Jö rg; Reiner, Thomas

2017-01-01

not yet explored for intraoperative imaging: chemiluminescent imaging. This method employs a ruthenium-based chemiluminescent reporter along with a custom-built nebulizing system to produce ex vivo or in vivo images with high signal-to-noise ratios

3D-printed and CNC milled flow-cells for chemiluminescence detection.

Science.gov (United States)

Spilstead, Kara B; Learey, Jessica J; Doeven, Egan H; Barbante, Gregory J; Mohr, Stephan; Barnett, Neil W; Terry, Jessica M; Hall, Robynne M; Francis, Paul S

2014-08-01

Herein we explore modern fabrication techniques for the development of chemiluminescence detection flow-cells with features not attainable using the traditional coiled tubing approach. This includes the first 3D-printed chemiluminescence flow-cells, and a milled flow-cell designed to split the analyte stream into two separate detection zones within the same polymer chip. The flow-cells are compared to conventional detection systems using flow injection analysis (FIA) and high performance liquid chromatography (HPLC), with the fast chemiluminescence reactions of an acidic potassium permanganate reagent with morphine and a series of adrenergic phenolic amines. Copyright © 2014 Elsevier B.V. All rights reserved.

Chemiluminescence. Principles and applications in biology and medicine

Energy Technology Data Exchange (ETDEWEB)

Campbell, A K

1988-01-01

Chemiluminescence, the emission of light caused by a chemical reaction, is a phenomenon used for many applications and of wide biological importance. It occurs in bacteria and insects (including glow-worms and fireflies), in many of the animals in the deep sea and even in human cells. The last 25 years have witnessed fast progress in the elucidation of the reactions and mechanisms underlying bioluminescence and light production by synthetic systems. Together with the development of highly sensitive light detectors, this has made available new biomedical methods and has given rise to new concepts concerning the biology and pathology of the cell. The book describes the occurrence, chemistry and measurement of chemiluminescence. It deals with the biological function and evolutionary significance, and looks at the many biomedical applications. The author describes the uses of chemiluminescence to measure enzymes, substrates and metabolites, to detect the changes of calcium concentration in living cells, to determine oxygen radicals or to replace the radioactive labels in immunoassays. Future applications in research and clinical laboratories are also discussed.

A chemiluminescent method for determination of lipid peroxidation

International Nuclear Information System (INIS)

Liang Xiaofeng; Hu Tianxi; Fan Xiaobing

2003-01-01

We established a chemiluminescent system for determination of lipid peroxidation and screening anti-oxidants. The lipid containing unsaturated fatly acids was injected into a galls tube. Luminol solution and the deionized water were added into it too. The glass tube was put into a preincubation box to incubate it for 0.5 h at 37 degree C. AAPH solution was injected into the tube for immediate measurement in a biochemiluminometer at 38-39 degree C. The pulses /6s(CP6s) were determined with T-2 program. Chemiluminescent dynamic and lipid peroxidation changes were observed continuously. Once the CL intensity of lipid peroxidation got peak, the antioxidant which has different concentration was added immediately in situ. A certain CL intensity (CP6s) was chosen as evaluation index to compare the activity of antioxidants. A luminol chemiluminescent system for determination of lipid peroxidation has been made. It was found that Vit. C, teapolyphenol, and glutathione have effects on scavenging lipid free radicals. The new method is quick, sensitive, and simple for determination of lipid peroxidation and screening antioxidants

Potential applications of robotics in advanced liquid-metal reactors

International Nuclear Information System (INIS)

Carroll, D.G.; Thompson, M.L.

1990-01-01

The advanced liquid-metal reactor (ALMR) design includes a range of robots and automation devices. They extend from stationary robots that are a part of the current design to more exotic concepts with mobile, autonomous units, which may become part of the design. Development of robotic application requirements is enhanced by using computer models of work spaces in three dimensions. The primary goals of the more autonomous machines are to: (1) extent and/or enhance one's capabilities in a hazardous environment; some tasks could encounter high temperatures (up to 800 degree F), high radiation (fields up to several hundred thousand roentgens per hour), rooms filled with inert gas and/or sodium aerosol, or combinations of these; (2) reduce operating and maintenance cost through inservice inspection (ISI) of various parts of the reactor, through consideration of as-low-as-reasonably achievable radiation levels, and through automation of some maintenance/processing operations. This paper discusses some applications in the fuel cycle, in refueling operations, and in inspection

Biological water quality monitoring using chemiluminescent and bioluminescent techniques

Science.gov (United States)

Thomas, R. R.

1978-01-01

Automated chemiluminescence and bioluminescence sensors were developed for the continuous monitoring of microbial levels in water supplies. The optimal chemical procedures were determined for the chemiluminescence system to achieve maximum sensitivity. By using hydrogen peroxide, reaction rate differentiation, ethylene diamine tetraacetic acid (EDTA), and carbon monoxide pretreatments, factors which cause interference were eliminated and specificity of the reaction for living and dead bacteria was greatly increased. By employing existing technology with some modifications, a sensitive and specific bioluminescent system was developed.

Simplex optimization of the variables influencing the determination of pefloxacin by time-resolved chemiluminescence

Science.gov (United States)

Murillo Pulgarín, José A.; Alañón Molina, Aurelia; Jiménez García, Elisa

2018-03-01

A new chemiluminescence (CL) detection system combined with flow injection analysis (FIA) for the determination of Pefloxacin is proposed. The determination is based on an energy transfer from Pefloxacin to terbium (III). The metal ion enhances the weak CL signal produced by the KMnO4/H2SO3/Pefloxacin system. A modified simplex method was used to optimize chemical and instrumental variables. The influence of the interaction of the permanganate, Tb (III), sodium sulphite and sulphuric acid concentrations, flow rate and injected sample volume was thoroughly investigated by using a modified simplex optimization procedure. The results revealed a strong direct relationship between flow rate and CL intensity throughout the studied range that was confirmed by a gamma test. The response factor for the CL emission intensity was used to assess performance in order to identify the optimum conditions for maximization of the response. Under such conditions, the CL response was proportional to the Pefloxacin concentration over a wide range. The detection limit as calculated according to Clayton's criterion 13.7 μg L- 1. The analyte was successfully determined in milk samples with an average recovery of 100.6 ± 9.8%.

Flow-injection chemiluminescence assay for ultra-trace determination of DNA using rhodamine B-Ce(IV)-DNA ternary system in sulfuric acid media

International Nuclear Information System (INIS)

Ma Yongjun; Zhou Min; Jin Xiaoyong; Zhang Ziyu; Teng Xiulan; Chen Hui

2004-01-01

A novel flow-injection chemiluminescence method for the determination of DNA at ultra-trace level has been established. In 0.8 M sulfuric acid media, the chemiluminescence of the rhodamine B-cerium (IV) or Ce(IV) system is enhanced by DNA, activated previously by imidazole-HCl buffer solution (pH 7.0). The enhanced intensity of chemiluminescence is in proportion to log DNA concentration 1.0x10 -8 to 0.1 μg ml -1 for herring sperm DNA and 2.0x10 -6 to 0.2 μg ml -1 for calf thymus DNA with 3σ detection limits of 8.3x10 -9 μg ml -1 for herring sperm DNA and 3.5x10 -7 μg ml -1 for calf thymus DNA, respectively. The relative standard deviation for 1.0x10 -4 μg ml -1 herring sperm DNA was 0.99% and 2.0x10 -3 μg ml -1 for calf thymus DNA was 1.1% (n=11). Using the optimized system, DNA contents in six synthetic samples has been determined with recoveries of 99.5-109.0%. The possible mechanism has also been studied in this paper

Flow-injection chemiluminescence assay for ultra-trace determination of DNA using rhodamine B-Ce(IV)-DNA ternary system in sulfuric acid media

Energy Technology Data Exchange (ETDEWEB)

Ma Yongjun; Zhou Min; Jin Xiaoyong; Zhang Ziyu; Teng Xiulan; Chen Hui

2004-01-09

A novel flow-injection chemiluminescence method for the determination of DNA at ultra-trace level has been established. In 0.8 M sulfuric acid media, the chemiluminescence of the rhodamine B-cerium (IV) or Ce(IV) system is enhanced by DNA, activated previously by imidazole-HCl buffer solution (pH 7.0). The enhanced intensity of chemiluminescence is in proportion to log DNA concentration 1.0x10{sup -8} to 0.1 {mu}g ml{sup -1} for herring sperm DNA and 2.0x10{sup -6} to 0.2 {mu}g ml{sup -1} for calf thymus DNA with 3{sigma} detection limits of 8.3x10{sup -9} {mu}g ml{sup -1} for herring sperm DNA and 3.5x10{sup -7} {mu}g ml{sup -1} for calf thymus DNA, respectively. The relative standard deviation for 1.0x10{sup -4} {mu}g ml{sup -1} herring sperm DNA was 0.99% and 2.0x10{sup -3} {mu}g ml{sup -1} for calf thymus DNA was 1.1% (n=11). Using the optimized system, DNA contents in six synthetic samples has been determined with recoveries of 99.5-109.0%. The possible mechanism has also been studied in this paper.

Safety design analyses of Korea Advanced Liquid Metal Reactor

International Nuclear Information System (INIS)

Suk, S.D.; Park, C.K.

2000-01-01

The national long-term R and D program updated in 1997 requires Korea Atomic Energy Research Institute (KAERI) to complete by the year 2006 the basic design of Korea Advanced Liquid Metal Reactor (KALIMER), along with supporting R and D work, with the capability of resolving the issue of spent fuel storage as well as with significantly enhanced safety. KALIMER is a 150 MWe pool-type sodium cooled prototype reactor that uses metallic fuel. The conceptual design is currently under way to establish a self consistent design meeting a set of the major safety design requirements for accident prevention. Some of current emphasis include those for inherent and passive means of negative reactivity insertion and decay heat removal, high shutdown reliability, prevention of and protection from sodium chemical reaction, and high seismic margin, among others. All of these requirements affect the reactor design significantly and involve supporting R and D programs of substance. This paper summarizes some of the results of engineering and design analyses performed for the safety of KALIMER. (author)

Chemiluminescence determination of ultramicro DNA with a flow-injection method

International Nuclear Information System (INIS)

Chen Hui; Zhou Min; Jin Xiaoyong; Song Yumin; Zhang Ziyu; Ma Yongjun

2002-01-01

A high sensitive flow-injection chemiluminescence method for determination of calf thymus DNA and herring sperm DNA has been developed. The method is based on the chemiluminescence reaction of Rhodamine B-cerium(IV)-thermally denatured DNAs in sulfuric acid media. The proposed procedure allows quantitation of DNAs in the range 2.6x10 -5 to 0.26 μg ml -1 for calf thymus DNA and 5.0x10 -8 to 5.0x10 -5 μg ml -1 for herring sperm DNA with correlation coefficients 0.9998 and 0.9996 (both n=11), respectively. The detection limits (3σ) are 6.5x10 -6 μg ml -1 for calf thymus DNA and 4.3x10 -8 μg ml -1 for herring sperm DNA. The possible mechanism of chemiluminescence in the system is discussed

Determination of hyperin in seed of Cuscuta chinensis Lam. by enhanced chemiluminescence of CdTe quantum dots on calcein/K3Fe(CN)6 system.

Science.gov (United States)

Kang, Jing; Li, Xuwen; Geng, Jiayang; Han, Lu; Tang, Jieli; Jin, Yongri; Zhang, Yihua

2012-10-15

In this paper, 3-mercaptocarboxylic acid (MPA) modified CdTe quantum dots (QDs) were used as sensitizers, to enhance the chemiluminescence (CL) of the calcein/K(3)Fe(CN)(6) system. A new CL system of CdTe/calcein/K(3)Fe(CN)(6) was developed. The effects of reactant concentrations and the particle sizes of CdTe QDs on the CL emission were investigated in detail. The possible enhancement mechanism of the CL was also further investigated based on the photoluminescence (PL) and CL spectra. Polyphenols such as chlorogenic acid, quercetin, hyperin, catechin and kaempferol, were observed to inhibit the CL signal of the CdTe/calcein/K(3)Fe(CN)(6) system and determined by the proposed method. The proposed method was applied to the determination of hyperin in seed of Cuscuta chinensis Lam. and the results obtained were satisfactory. Copyright © 2012 Elsevier Ltd. All rights reserved.

Determination of cyanide using a chemiluminescence system composed of permanganate, rhodamine B, and gold nanoparticles

International Nuclear Information System (INIS)

Amjadi, Mohammad; Hassanzadeh, Javad; Manzoori, Jamshid L.

2014-01-01

We describe a new chemiluminescence (CL) system based on the oxidation of rhodamine B (RhoB) with alkaline potassium permanganate in the presence of gold nanoparticles (Au-NPs) and anionic detergent sodium dodecyl sulfate. Free RhoB is weakly chemiluminescent when oxidized with permanganate at alkaline pH values. However, a remarkably strong enhancement of CL is observed in the presence of Au-NPs, probably due to a strong interaction between RhoB and the NPs. The possible mechanism was studied via recording the CL emission. It is also found that the intensity of CL gradually decreases in the presence of cyanide due to its interaction with the Au-NPs. The relation between the decreased CL intensity and cyanide concentration was exploited to develop a method for the determination of cyanide in the 0.01–0.5 μM concentration range, with a detection limit of 2.8 nM. The method was used to determine cyanide in spiked water, urine, and serum. (author)

Utility industry evaluation of the metal fuel facility and metal fuel performance for liquid metal reactors

International Nuclear Information System (INIS)

Burstein, S.; Gibbons, J.P.; High, M.D.; O'Boyle, D.R.; Pickens, T.A.; Pilmer, D.F.; Tomonto, J.R.; Weinberg, C.J.

1990-02-01

A team of utility industry representatives evaluated the liquid metal reactor metal fuel process and facility conceptual design being developed by Argonne National Laboratory (ANL) under Department of Energy sponsorship. The utility team concluded that a highly competent ANL team was making impressive progress in developing high performance advanced metal fuel and an economic processing and fabrication technology. The utility team concluded that the potential benefits of advanced metal fuel justified the development program, but that, at this early stage, there are considerable uncertainties in predicting the net overall economic benefit of metal fuel. Specific comments and recommendations are provided as a contribution towards enhancing the development program. 6 refs

Long-term chemiluminescence signal is produced in the course of luminol oxidation catalyzed by enhancer-independent peroxidase purified from Jatropha curcas leaves.

Science.gov (United States)

Duan, Peipei; Cai, Feng; Luo, Yongting; Chen, Yangxi; Zou, Shujuan

2015-09-01

Isoenzyme c of horseradish peroxidase (HRP-C) is widely used in enzyme immunoassay combined with chemiluminescence (CL) detection. For this application, HRP-C activity measurement is usually based on luminol oxidation in the presence of hydrogen peroxide (H2O2). However, this catalysis reaction was enhancer dependent. In this study, we demonstrated that Jatropha curcas peroxidase (JcGP1) showed high efficiency in catalyzing luminol oxidation in the presence of H2O2. Compared with HRP-C, the JcGP1-induced reaction was enhancer independent, which made the enzyme-linked immunosorbent assay (ELISA) simpler. In addition, the JcGP1 catalyzed reaction showed a long-term stable CL signal. We optimized the conditions for JcGP1 catalysis and determined the favorable conditions as follows: 50 mM Tris buffer (pH 8.2) containing 10 mM H2 O2, 14 mM luminol and 0.75 M NaCl. The optimum catalysis temperature was 30°C. The detection limit of JcGP1 under optimum condition was 0.2 pM. Long-term stable CL signal combined with enhancer-independent property indicated that JcGP1 might be a valuable candidate peroxidase for clinical diagnosis and enzyme immunoassay with CL detection. Copyright © 2014 John Wiley & Sons, Ltd.

Imaging and high-sensitivity quantification of chemiluminescent labeled DNA-blots

International Nuclear Information System (INIS)

Dorner, G.

1997-01-01

The present thesis has for objective the development of both, methods of DNA labeling by chemiluminescence (via the catalytic activity of the enzyme alkaline phosphatase - AP) and an appropriate imaging system. Offering a competitive alternative to the detection of classical radio-labels in molecular-biological experiments of the blotting type, this technique should permit the realization of quantitative studies of gene expression at ultra-high sensitivity necessary in particular for differential-screening experiments. To reach our aim. we separated the project into three different parts. In a first step an imager based on a liquid-nitrogen-cooled CCD coupled to a standard optics (50 mm/fl.2) has been installed and characterized. This system offers a sensitive area of up to 625 cm 2 , a spatial resolution of 0.3-1 mm (depending on the field of view) and a sensitivity sufficient to detect 10 fg/mm 2 labeled DNA. In a second part, the chemiluminescent light-generation process in solution has been investigated to optimize the parameters temperature. pH and concentration of the substrate as well as the enzyme. The substrate offering the highest light yield (CDP-Star in addition with the enhancer EMERALD II) allows quantification of AP down to 10 -15 M within a dynamic range of 10 4 in solution. Finally. preparation, immobilization and detection of AP-labeled DNA probes (via a biotin-streptavidin-biotin-AP bridge) on nylon membranes has been optimized. A linear relation between the light intensities and the amount of DNA was observed in a range of 10 fg/mm 2 - 100 pg/mm 2 . Hybridization of the probes to bacterial cloned target-DNA has been addressed after examination of the best hybridization conditions. Our protocol includes the treatment of a proteinase, which resulted in a significantly lower background on the filter. The results of our investigations suggest that the main conditions for a reliable differential-screening experiment are fulfilled when using

Chemiluminescence determination of ultramicro DNA with a flow-injection method

Energy Technology Data Exchange (ETDEWEB)

Chen Hui; Zhou Min; Jin Xiaoyong; Song Yumin; Zhang Ziyu; Ma Yongjun

2002-02-12

A high sensitive flow-injection chemiluminescence method for determination of calf thymus DNA and herring sperm DNA has been developed. The method is based on the chemiluminescence reaction of Rhodamine B-cerium(IV)-thermally denatured DNAs in sulfuric acid media. The proposed procedure allows quantitation of DNAs in the range 2.6x10{sup -5} to 0.26 {mu}g ml{sup -1} for calf thymus DNA and 5.0x10{sup -8} to 5.0x10{sup -5} {mu}g ml{sup -1} for herring sperm DNA with correlation coefficients 0.9998 and 0.9996 (both n=11), respectively. The detection limits (3{sigma}) are 6.5x10{sup -6} {mu}g ml{sup -1} for calf thymus DNA and 4.3x10{sup -8} {mu}g ml{sup -1} for herring sperm DNA. The possible mechanism of chemiluminescence in the system is discussed.

Dendrimer-based biosensor for chemiluminescent detection of DNA hybridization

International Nuclear Information System (INIS)

Liu, P.; Hun, X.; Qing, H.

2011-01-01

We report on a highly sensitive chemiluminescent (CL) biosensor for the sequence-specific detection of DNA using a novel bio barcode DNA probe modified with gold nanoparticles that were covered with a dendrimer. The modified probe is composed of gold nanoparticles, a dendrimer, the CL reagent, and the DNA. The capture probe DNA was immobilized on magnetic beads covered with gold. It first hybridizes with the target DNA and then with one terminal end of the signal DNA on the barcoded DNA probe. CL was generated by adding H 2 O 2 and Co(II) ions as the catalyst. The immobilization of dendrimer onto the gold nanoparticles can significantly enhance sensitivity and gives a detection limit of 6 fmol L -1 of target DNA. (author)

Advances in Metal Supported Cells in the METSOFC EU Consortium

DEFF Research Database (Denmark)

McKenna, Brandon J.; Christiansen, Niels; Schauperl, Richard

2012-01-01

Employing a mechanically robust metal support as the structural element in SOFC has been the objective of various development efforts. The EU-sponsored project “METSOFC”, completed at the end of 2011, resulted in a number of advancements towards implementing this strategy. These include robust me...... outcomes of the METSOFC consortium are covered, along with associated work supported by the Danish National Advanced Technology Foundation.......Employing a mechanically robust metal support as the structural element in SOFC has been the objective of various development efforts. The EU-sponsored project “METSOFC”, completed at the end of 2011, resulted in a number of advancements towards implementing this strategy. These include robust...... metal supported cells (MSCs) having low ASR at low temperature, incorporation into small stacks of powers approaching ½kW, and stack tolerance to various operation cycles. DTU Energy Conversion's (formerly Risø DTU) research into planar MSCs has produced an advanced cell design with high performance...

The effect of advanced treatment of sewage effluents on metal speciation and (bio)availability.

Science.gov (United States)

Peters, A; Merrington, G; Leverett, D; Ellor, B; Lofts, S; Gravell, A

2014-02-01

The bioavailability of metals can be strongly influenced by dissolved organic carbon (DOC). Wastewater treatment effluents add considerable quantities of DOC and metals to receiving waters, and as effluent controls become more stringent advanced effluent treatments may be needed. We assessed the effects of two types of advanced treatment processes on metal availability in wastewater effluents. Trace metal availability was assessed using diffuse gradients in thin films and predicted through speciation modelling. The results show little difference in metal availability post-advanced treatment. EDTA-like compounds are important metal complexants in the effluents.

NATO Advanced Study Institute on Metal Hydrides

CERN Document Server

1981-01-01

In the last five years, the study of metal hydrides has ex­ panded enormously due to the potential technological importance of this class of materials in hydrogen based energy conversion schemes. The scope of this activity has been worldwide among the industrially advanced nations. There has been a consensus among researchers in both fundamental and applied areas that a more basic understanding of the properties of metal/hydrogen syster;,s is required in order to provide a rational basis for the selection of materials for specific applications. The current worldwide need for and interest in research in metal hydrides indicated the timeliness of an Advanced Study Insti­ tute to provide an in-depth view of the field for those active in its various aspects. The inclusion of speakers from non-NATO coun­ tries provided the opportunity for cross-fertilization of ideas for future research. While the emphasis of the Institute was on basic properties, there was a conscious effort to stimulate interest in the applic...

Determination of ethamsylate in pharmaceutical preparations based on an auto-oxidation chemiluminescence reaction.

Science.gov (United States)

Yang, Fengzhen; Zhang, Chao; Baeyens, Willy R G; Zhang, Xinrong

2002-10-15

Strong chemiluminescence emission has been observed by mixing alkaline hydrolytic products of ethamsylate with Tween 80 in acidic rhodamine 6G solution. This phenomenon has been utilized to design a flow-injection chemiluminescence method for the determination of ethamsylate in a pharmaceutical preparation. Under the optimum conditions, the proposed procedure has a linear range between 0.05 and 2.0 microg ml(-1), with a detection limit of 0.02 microg ml(-1) for ethamsylate. The method was applied to the determination of ethamsylate in pharmaceutical preparations. The possible mechanism of this chemiluminescence reaction was proposed. Copyright 2002 Elsevier Science B.V.

Metal Advanced Manufacturing Bot-Assisted Assembly (MAMBA) Process, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Tethers Unlimited, Inc. (TUI) proposes to develop the Metal Advanced Manufacturing Bot-Assisted Assembly (MAMBA) Process, a robotically managed metal press and...

Metal Enhanced Fluorescence on Super-Hydrophobic Clusters of Gold Nanoparticles

KAUST Repository

Battista, Edmondo; Coluccio, Maria Laura; Alabastri, Alessandro; Barberio, Marianna; Causa, Filippo; Netti, Paolo Antonio; Di Fabrizio, Enzo M.; Gentile, Francesco

2016-01-01

We used optical lithography, electroless deposition and deep reactive ion etching techniques to realize arrays of super-hydrophobic gold nanoparticles arranged in a hierarchical structure. At the micro-scale, silicon-micro pillars in the chip permit to manipulate and concentrate biological solutions, at the nano-scale, gold nanoparticles enable metal enhanced fluorescence (MEF) effects, whereby fluorescence signal of fluorophores in close proximity to a rough metal surface is amplified by orders of magnitude. Here, we demonstrated the device in the analysis of fluorescein derived gold-binding peptides (GBP-FITC). While super-hydrophobic schemes and MEF effects have been heretofore used in isolation, their integration in a platform may advance the current state of fluorescence-based sensing technology in medical diagnostics and biotechnology. This scheme may be employed in protein microarrays where the increased sensitivity of the device may enable the early detection of cancer biomarkers or other proteins of biomedical interest.

Metal Enhanced Fluorescence on Super-Hydrophobic Clusters of Gold Nanoparticles

KAUST Repository

Battista, Edmondo

2016-12-15

We used optical lithography, electroless deposition and deep reactive ion etching techniques to realize arrays of super-hydrophobic gold nanoparticles arranged in a hierarchical structure. At the micro-scale, silicon-micro pillars in the chip permit to manipulate and concentrate biological solutions, at the nano-scale, gold nanoparticles enable metal enhanced fluorescence (MEF) effects, whereby fluorescence signal of fluorophores in close proximity to a rough metal surface is amplified by orders of magnitude. Here, we demonstrated the device in the analysis of fluorescein derived gold-binding peptides (GBP-FITC). While super-hydrophobic schemes and MEF effects have been heretofore used in isolation, their integration in a platform may advance the current state of fluorescence-based sensing technology in medical diagnostics and biotechnology. This scheme may be employed in protein microarrays where the increased sensitivity of the device may enable the early detection of cancer biomarkers or other proteins of biomedical interest.

Precious-metal-base advanced materials

International Nuclear Information System (INIS)

Nowicki, T.; Carbonnaux, C.

1993-01-01

Precious metals constitute also the base of several advanced materials used in the industry in hundreds of metric tons. Platinum alloys have been used as structural materials for equipments in the glass industry. The essential reason for this is the excellent resistance of platinum alloys to oxidation and electrolytical corrosion in molten glasses at temperatures as high as 1200-1500 C. The major drawback is a weak creep resistance. The unique way for significant improvement of platinum base materials creep resistance is a strengthening by an oxide dispersion (ODS). In the case of CLAL's patented ''Plativer'' materials, 0.05 wt% of Y 2 O 3 is incorporated within the alloy matrix by the flame spraying process. Further improvement of platinum base materials is related, in the authors opinion, to the development of precious metals base intermetallics. Another interesting applications of precious metals are silver base electrical contacts. They are in fact silver matrix composites containing varying amounts of well-dispersed particles of constituents such as CdO, SnO 2 , Ni, WC or C. In the case of such materials, particular properties are required and tested : resistance to arc erosion, resistance to welding and contact resistance. Many other technically fascinating precious metals base materials exist: brazing alloys for assembling metals, superconductors and ceramics; dental materials including magnetic biocompatible alloys; silver composites for superconductor wire jackets. The observation of current evolution indicates very clearly that precious metals cannot be replaced by common metals because of their unique characteristics due to their atomic level properties

Characteristic of peroxyoxalate-chemiluminescence intensity in the presence of Chlorpheniramine maleate and its analytical application

International Nuclear Information System (INIS)

Samadi-Maybodi, Abdolraouf; Akhoondi, Reza

2011-01-01

It has been shown that Chlorpheniramine maleate (CPM) increases chemiluminescence intensity of bis-(2,4,6-trichlorophenyl)oxalate (TCPO) with hydrogen peroxide in the presence of biphenylquinoxaline as a fluorophore. In this work, the effect of CPM on the intensity of chemiluminescence (CL) in the system of (TCPO-sodium salicylate-fluorophore-hydrogen peroxide) was investigated. The fall and rise rates constants were also studied. A pooled-intermediate model was used for determining the kinetics parameters of CL with and without CPM. Results indicated that addition of CMP to this system increases the fall rate constant and decreases the rise rate constant. Results also specified that there is a linear relationship between CPA concentration and chemiluminescence intensity in the range 0.66-21.5 μg/ml. Detection limit 0.18 μg/ml and the relative standard deviation (RSD) 2 O 2 - sodium salicylate- fluorescer) in the presence of chlorpheniramine maleate. → Results also introduced a reliable method for determination of chlorpheniramine using peroxyoxalte chemiluminescence system. → A pooled-intermediate model was used for determination the kinetics parameters of chemiluminescence with and without chlorpheniramine maleate. → Results also specified that there is a linear relationship between chlorpheniramine maleate concentration and chemiluminescence intensity.

СHANGES IN PARAMETERS OF LUMINOL-DEPENDENT AND LUCIGENIN-DEPENDENT CHEMILUMINESCENCE OF PERIPHERAL BLOOD NEUTROPHILS IN PATIENTS WITH BLADDER CANCER IN THE DISEASE DYNAMICS

Directory of Open Access Journals (Sweden)

L. M. Kurtasova

2015-01-01

Full Text Available The study deals with parameters of luminol-dependent and lucigenin-dependent chemiluminescence (CL of peripheral blood neutrophils from patients with bladder cancer (BC prior to surgical treatment. We examined sixty patients (45 to 55 years old with advanced bladder cancer (TNM prior to the operation, and forty-six patients at 10 days after surgical treatment. A control group consisted of 56 healthy donors. Luminol-dependent and lucigenin-dependent chemiluminescence of blood neutrophils was assessed according to De Sole et al. (1983. Chemiluminescence assays of peripheral blood neutrophils from the patients with bladder cancer revealed changes in production of reactive oxygen species (ROS, both for initial stage of oxidation reaction, and total level of active oxygen radicals. We have found disturbed values of primary-to-secondary ROS ratio in the cells. In the patients with bladder cancer, some changes in oxidative metabolism of the blood neutrophils have been registered. These alterations may play an important role in promotion of potential effector cell functions, thus, probably, affecting the whole-scale development of a cytopathic effect exerted by neutrophilic granulocytes. 

A readout circuit dedicated for the detection of chemiluminescence using a silicon photomultiplier

Science.gov (United States)

Baszczyk, M.; Dorosz, P.; Mik, L.; Kucewicz, W.; Reczynski, W.; Sapor, M.

2018-05-01

A readout circuit dedicated for the detection of the chemiluminescence phenomenon using a silicon photomultiplier (SiPM) is presented. During chemiluminescence, light is generated as a result of chemical reaction. Chemiluminescence is used in many applications within medicine, chemistry, biology and biotechnology, and is one of the most important sensing techniques in biomedical science and clinical medicine. The front-end electronics consist of a preamplifier and a fast shaper—this produces pulses, the peaking time which is 3.6 ns for a single photon and the FWHM is 3.8 ns. The system has been optimised to measure chemiluminescence—it is sensitive at the level of single photons, it generates a low number of overlapping pulses and is accurate. Two methods of signal detection are analysed and compared: the counting of events and amplitude detection. The relationship between the chemiluminescence light intensity and the concentration of the chemical compound (luminol) is linear in the range of the tested concentrations and has strong linearity parameters and low prediction intervals.

Advanced liquid metal reactor plant control system

International Nuclear Information System (INIS)

Dayal, Y.; Wagner, W.; Zizzo, D.; Carroll, D.

1993-01-01

The modular Advanced Liquid Metal Reactor (ALMR) power plant is controlled by an advanced state-of-the-art control system designed to facilitate plant operation, optimize availability, and protect plant investment. The control system features a high degree of automatic control and extensive amount of on-line diagnostics and operator aids. It can be built with today's control technology, and has the flexibility of adding new features that benefit plant operation and reduce O ampersand M costs as the technology matures

Laser-saturated fluorescence of nitric oxide and chemiluminescence measurements in premixed ethanol flames

Energy Technology Data Exchange (ETDEWEB)

Marques, Carla S.T.; Barreta, Luiz G.; Sbampato, Maria E.; dos Santos, Alberto M. [Aerothermodynamic and Hypersonic Division, Institute of Advanced Studies - General Command of Aerospatial Technology, Rodovia dos Tamoios, km 5.5, 12228-001 Sao Jose dos Campos - SP (Brazil)

2010-11-15

In this study, nitric oxide laser-saturated fluorescence (LSF) measurements were acquired from premixed ethanol flames at atmospheric pressure in a burner. NO-LSF experimental profiles for fuel-rich premixed ethanol flames ({phi} = 1.34 and {phi} = 1.66) were determined through the excitation/detection scheme of the Q{sub 2}(26.5) rotational line in the A{sup 2}{sigma}{sup +} - X{sup 2}{pi} (0,0) vibronic band and {gamma}(0,1) emission band. A calibration procedure by NO doping into the flame was applied to establish the NO concentration profiles in these flames. Chemiluminescent emission measurements in the (0, 0) vibronic emission bands of the OH{sup *} (A{sup 2}{sigma}{sup +} - X{sup 2}{pi}) and CH{sup *}(A{sup 2}{delta} - X{sup 2}{pi}) radicals were also obtained with high spatial and spectral resolution for fuel-rich premixed ethanol flames to correlate them with NO concentrations. Experimental chemiluminescence profiles and the ratios of the integrated areas under emission spectra (A{sub CH*}/A{sub CH*}(max.) and A{sub CH*}/A{sub OH*}) were determined. The relationships between chemiluminescence and NO concentrations were established along the premixed ethanol flames. There was a strong connection between CH{sup *} radical chemiluminescence and NO formation and the prompt-NO was identified as the governing mechanism for NO production. The results suggest the optimum ratio of the chemiluminescence of two radicals (A{sub CH*}/A{sub OH*}) for NO diagnostic purposes. (author)

Investigation of iron(III) reduction and trace metal interferences in the determination of dissolved iron in seawater using flow injection with luminol chemiluminescence detection

Energy Technology Data Exchange (ETDEWEB)

Ussher, Simon J. [School of Earth, Ocean and Environmental Sciences (SEOES), University of Plymouth, Drake Circus, Plymouth PL4 8AA (United Kingdom); Milne, Angela [School of Earth, Ocean and Environmental Sciences (SEOES), University of Plymouth, Drake Circus, Plymouth PL4 8AA (United Kingdom); Department of Oceanography, Florida State University, Tallahassee, FL 32306-4320 (United States); Landing, William M. [Department of Oceanography, Florida State University, Tallahassee, FL 32306-4320 (United States); Attiq-ur-Rehman, Kakar [Department of Chemistry, University of Balochistan, Quetta (Pakistan); Seguret, Marie J.M.; Holland, Toby [School of Earth, Ocean and Environmental Sciences (SEOES), University of Plymouth, Drake Circus, Plymouth PL4 8AA (United Kingdom); Achterberg, Eric P. [National Oceanography Centre, University of Southampton, European Way, Southampton SO14 3ZH (United Kingdom); Nabi, Abdul [Department of Chemistry, University of Balochistan, Quetta (Pakistan); Worsfold, Paul J., E-mail: pworsfold@plymouth.ac.uk [School of Earth, Ocean and Environmental Sciences (SEOES), University of Plymouth, Drake Circus, Plymouth PL4 8AA (United Kingdom)

2009-10-12

A detailed investigation into the performance of two flow injection-chemiluminescence (FI-CL) manifolds (with and without a preconcentration column) for the determination of sub-nanomolar dissolved iron (Fe(II) + Fe(III)), following the reduction of Fe(III) by sulphite, in seawater is described. Kinetic experiments were conducted to examine the efficiency of reduction of inorganic Fe(III) with sulphite under different conditions and a rigorous study of the potential interference caused by other transition metals present in seawater was conducted. Using 100 {mu}M concentrations of sulphite a reduction time of 4 h was sufficient to quantitatively reduce Fe(III) in seawater. Under optimal conditions, cobalt(II) and vanadium(IV)/(III) were the major positive interferences and strategies for their removal are reported. Specifically, cobalt(II) was masked by the addition of dimethylglyoxime to the luminol solution and vanadium(IV) was removed by passing the sample through an 8-hydroxyquinoline column in a low pH carrier stream. Manganese(II) also interfered by suppression of the CL response but this was not significant at typical open ocean concentrations.

Electroluminescence Efficiency Enhancement using Metal Nanoparticles

National Research Council Canada - National Science Library

Soref, Richard A; Khurgin, J. B; Sun, G

2008-01-01

We apply the "effective mode volume" theory to evaluate enhancement of the electroluminescence efficiency of semiconductor emitters placed in the vicinity of isolated metal nanoparticles and their arrays...

Application of multi-step excitation schemes for detection of actinides and lanthanides in solutions by luminescence/chemiluminescence laser spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Izosimov, I. [Joint Institute for Nuclear Research, Joliot Curie 6, Dubna 141980 (Russian Federation)

2016-07-01

The use of laser radiation with tunable wavelength allows the selective excitation of actinide/lanthanide species with subsequent registration of luminescence/chemiluminescence for their detection. This work is devoted to applications of the time-resolved laser-induced luminescence spectroscopy and time-resolved laser-induced chemiluminescence spectroscopy for the detection of lanthanides and actinides. Results of the experiments on U, Eu, and Sm detection by TRLIF (Time Resolved Laser Induced Fluorescence) method in blood plasma and urine are presented. Data on luminol chemiluminescence in solutions containing Sm(III), U(IV), and Pu(IV) are analyzed. It is shown that appropriate selectivity of lanthanide/actinide detection can be reached when chemiluminescence is initiated by transitions within 4f- or 5f-electron shell of lanthanide/actinide ions corresponding to the visible spectral range. In this case chemiluminescence of chemiluminogen (luminol) arises when the ion of f element is excited by multi-quantum absorption of visible light. The multi-photon scheme of chemiluminescence excitation makes chemiluminescence not only a highly sensitive but also a highly selective tool for the detection of lanthanide/actinide species in solutions. (author)

Metal-enhanced luminescence: Current trend and future perspectives- A review

International Nuclear Information System (INIS)

Ranjan, Rajeev; Esimbekova, Elena N.; Kirillova, Maria A.; Kratasyuk, Valentina A.

2017-01-01

Optically enhanced biosensing strategies are prerequisites for developing miniature and highly sensitive multiplexed analytical platforms. Such smart biosensing systems are highly promising for use in the fields of biomedicine and environmental monitoring. Optical signal enhancement during bioassays is attributed to the complex opto-electronic interactions of incoming photonic signals at the nanomaterial interface. Research on the use of metals other than gold and silver for such purposes tends to extend the spectral window to observe luminescence enhancement effects. Such manifold increase in luminescence may be explained by the principles of plasmon coupling, directional emission led high collection efficiency, Rayleigh scattering and related opto-electronic events. The present review begins with a mechanistic description of important phenomena associated with metal-induced luminescence enhancement, particularly focusing on the origin of metal-enhanced luminescence. This review further analyses the hybrid nanostructure capabilities responsible for maintaining unique opto-electronic properties during bio-functionalisation. Current research trends in this area, future scope of this field for designing useful bioassays and concluding remarks are then discussed. - Highlights: • Nanomaterials significantly differ from their bulk counterparts. • Strong and pronounced photophysical effects at the metal surface provide opportunities for designing novel biosensors. • Metal-enhanced luminescence increases the quantum yield of luminescent reactions. • Under optimal conditions, plasmon coupling enhances the optical effects at the nanometal surface.

Metal-enhanced luminescence: Current trend and future perspectives- A review

Energy Technology Data Exchange (ETDEWEB)

Ranjan, Rajeev [Laboratory of Bioluminescent Biotechnologies, Department of Biophysics, Institute of Fundamental Biology and Biotechnology, Siberian Federal University, 79 Svobodny Prospect, Krasnoyarsk 660041 (Russian Federation); Esimbekova, Elena N., E-mail: esimbekova@yandex.ru [Laboratory of Bioluminescent Biotechnologies, Department of Biophysics, Institute of Fundamental Biology and Biotechnology, Siberian Federal University, 79 Svobodny Prospect, Krasnoyarsk 660041 (Russian Federation); Institute of Biophysics SB RAS, Federal Research Center “Krasnoyarsk Science Center SB RAS”, Akademgorodok 50/50, Krasnoyarsk 660036 (Russian Federation); Kirillova, Maria A. [Laboratory of Bioluminescent Biotechnologies, Department of Biophysics, Institute of Fundamental Biology and Biotechnology, Siberian Federal University, 79 Svobodny Prospect, Krasnoyarsk 660041 (Russian Federation); Kratasyuk, Valentina A. [Laboratory of Bioluminescent Biotechnologies, Department of Biophysics, Institute of Fundamental Biology and Biotechnology, Siberian Federal University, 79 Svobodny Prospect, Krasnoyarsk 660041 (Russian Federation); Institute of Biophysics SB RAS, Federal Research Center “Krasnoyarsk Science Center SB RAS”, Akademgorodok 50/50, Krasnoyarsk 660036 (Russian Federation)

2017-06-08

Optically enhanced biosensing strategies are prerequisites for developing miniature and highly sensitive multiplexed analytical platforms. Such smart biosensing systems are highly promising for use in the fields of biomedicine and environmental monitoring. Optical signal enhancement during bioassays is attributed to the complex opto-electronic interactions of incoming photonic signals at the nanomaterial interface. Research on the use of metals other than gold and silver for such purposes tends to extend the spectral window to observe luminescence enhancement effects. Such manifold increase in luminescence may be explained by the principles of plasmon coupling, directional emission led high collection efficiency, Rayleigh scattering and related opto-electronic events. The present review begins with a mechanistic description of important phenomena associated with metal-induced luminescence enhancement, particularly focusing on the origin of metal-enhanced luminescence. This review further analyses the hybrid nanostructure capabilities responsible for maintaining unique opto-electronic properties during bio-functionalisation. Current research trends in this area, future scope of this field for designing useful bioassays and concluding remarks are then discussed. - Highlights: • Nanomaterials significantly differ from their bulk counterparts. • Strong and pronounced photophysical effects at the metal surface provide opportunities for designing novel biosensors. • Metal-enhanced luminescence increases the quantum yield of luminescent reactions. • Under optimal conditions, plasmon coupling enhances the optical effects at the nanometal surface.

Autometallography: tissue metals demonstrated by a silver enhancement kit

DEFF Research Database (Denmark)

Danscher, G; Nørgaard, J O; Baatrup, E

1987-01-01

, primarily intended for the amplification of colloidal gold particles, has been used to demonstrate these catalytic tissue metals. Sections from animals exposed intravitally to aurothiomalatate, silver lactate, mercury chloride, sodium selenite or perfused with sodium sulphide were subjected to a commercial......In biological tissue, minute accumulations of gold, silver, mercury and zinc can be visualized by a technique whereby metallic silver is precipitated on tiny accumulations of the two noble metals, or on selenites or sulphides of all four metals. In the present study a silver enhancement kit...... silver enhancement kit (IntenSE, Janssen Pharmaceutica). It was found that the kit performs adequately to the silver lactate gum arabic developer and to the photographic emulsion technique. The kit can be used as a silver enhancement medium for the demonstration of zinc by the Neo-Timm and selenium...

Enhancement of metal bioremediation by use of microbial surfactants

International Nuclear Information System (INIS)

Singh, Pooja; Cameotra, Swaranjit Singh

2004-01-01

Metal pollution all around the globe, especially in the mining and plating areas of the world, has been found to have grave consequences. An excellent option for enhanced metal contaminated site bioremediation is the use of microbial products viz. microbial surfactants and extracellular polymers which would increase the efficiency of metal reducing/sequestering organisms for field bioremediation. Important here is the advantage of such compounds at metal and organic compound co-contaminated site since microorganisms have long been found to produce surface-active compounds when grown on hydrocarbons. Other options capable of proving efficient enhancers include exploiting the chemotactic potential and biofilm forming ability of the relevant microorganisms. Chemotaxis towards environmental pollutants has excellent potential to enhance the biodegradation of many contaminants and biofilm offers them a better survival niche even in the presence of high levels of toxic compounds

Determination of phenolic compounds using high-performance liquid chromatography with Ce4+-Tween 20 chemiluminescence detection

International Nuclear Information System (INIS)

Cui Hua; Zhou Jian; Xu Feng; Lai Chunze; Wan Guohui

2004-01-01

A novel method for the simultaneous determination of phenolic compounds such as salicylic acid, resorcinol, phloroglucinol, p-hydroxybenzoic acid, 2,4-dihydroxybenzoic acid, and m-nitrophenol by high-performance liquid chromatography (HPLC) coupled with chemiluminescence (CL) detection was developed. The procedure was based on the chemiluminescent enhancement by phenolic compounds of the cerium(IV)-Tween 20 system in a sulfuric acid medium. The separation was carried out with an isocratic elution or with a gradient elution using a mixture of methanol and 1.5% acetic acid. For six phenolic compounds, the detection limits (3σ) were in the range 1.40-5.02 ng/ml and the relative standard deviations (n=11) for the determination of 0.1 μg/ml compounds were in the range 1.9-2.9%. The CL reaction was well compatible with the mobile phase of HPLC, no baseline drift often occurred in HPLC-CL detection was observed with a gradient elution. The method has been successfully applied to the determination of salicylic acid and resorcinol in Dermatitis Clear Tincture and p-hydroxybenzoic acid in apple juices

Enhancement of periodate-hydrogen peroxide chemiluminescence by nitrogen doped carbon dots and its application for the determination of pyrogallol and gallic acid.

Science.gov (United States)

Shah, Syed Niaz Ali; Li, Haifang; Lin, Jin-Ming

2016-06-01

A new sensitized chemiluminescence (CL) was developed to broaden the analytical application of KIO4-H2O2 system. The nitrogen doped carbon dots (N-CDs) dramatically boosted the CL intensity of KIO4-H2O2 system which was further enriched by basic medium. In light of EPR analysis, free radical scavenging studies and CL spectra the detail mechanism for the enhancement was conferred in the presence of N-CDs and NaOH. The results suggested that CL of KIO4-H2O2 system in the presence and absence of N-CDs and NaOH proceeds via radical pathway. The enhanced CL was used for the determination of pyrogallol and gallic acid in range of 1.0×10(-4)-1.0×10(-7)M with 4.6×10(-8) and 6.1×10(-8)M limit of detection respectively. The relative standard deviation (RSD) at a concentration of 10(-5) for gallic acid and pyrogallol was 1.4% and 2.3% respectively (n=11). The attained results unveil that the present method is sensitive, faster, simpler and less costly compared to other methods and could be applied to determine polyphenols in real samples. Copyright © 2016 Elsevier B.V. All rights reserved.

Surface-enhanced Raman scattering from metal and transition metal nano-caped arrays

Science.gov (United States)

Sun, Huanhuan; Gao, Renxian; Zhu, Aonan; Hua, Zhong; Chen, Lei; Wang, Yaxin; Zhang, Yongjun

2018-03-01

The metal and transition metal cap-shaped arrays on polystyrene colloidal particle (PSCP) templates were fabricated to study the surface-enhanced Raman scattering (SERS) effect. We obtained the Ag and Fe complex film by a co-sputtering deposition method. The size of the deposited Fe particle was changed by the sputtering power. We also study the SERS enhancement mechanism by decorating the PATP probe molecule on the different films. The SERS signals increased firstly, and then decreased as the size of Fe particles grows gradually. The finite-difference time domain (FDTD) simulation and experimental Raman results manifest that SERS enhancement was mainly attributed to surface plasma resonance (SPR) between Ag and Ag nanoparticles. The SERS signals of PATP molecule were enhanced to reach a lowest detectable concentration of 10-8 mol/L. The research demonstrates that the SERS substrates with Ag-Fe cap-shaped arrays have a high sensitivity.

Conceptual safety design analysis of Korea advanced liquid metal reactor

International Nuclear Information System (INIS)

Suk, S. D.; Park, C. K.

1999-01-01

The national long-term R and D program, updated in 1977, requires Korea Atomic Energy Research Institute (KAERI) to complete by the year 2006 the basic design of Korea Advanced Liquid Metal Reactor (KALIMER), along with supporting R and D work, with the capability of resolving the issue of spent fuel storage as well as with significantly enhanced safety. KALIMER is a 150 Mwe pool-type sodium cooled prototype reactor that uses metallic fuel. The conceptual design is currently under way to establish a self-consistent design meeting a set of major safety design requirements for accident prevention. Some of the current emphasis includes those for inherent and passive means of negative reactivity insertion and decay heat removal, high shutdown reliability, prevention of and protection from sodium chemical reaction, and high seismic margin, among others. All of these requirements affect the reactor design significantly and involve extensive supporting R and D programs. This paper summarizes some of the results of conceptual engineering and design analyses performed for the safety of KALIMER in the area of inherent safety, passive decay heat removal, sodium water reaction, and seismic isolation. (author)

[Research advances in heavy metals pollution ecology of diatom].

Science.gov (United States)

Ding, Teng-Da; Ni, Wan-Min; Zhang, Jian-Ying

2012-03-01

Diatom, due to its high sensitivity to environmental change, is one of the bio-indicators of aquatic ecosystem health, and some typical diatom species have been applied to indicate the heavy metals pollution of water body. With the focus on the surface water heavy metals pollution, this paper reviewed the research advances in the toxic effect of heavy metals pollution on diatom, biosorption and bioaccumulation of heavy metals by diatom, ecological adaptation mechanisms of diatom to heavy metals pollution, and roles of diatom as bio-indicator and in ecological restoration of heavy metals pollution. The growth tendency of diatom and the morphological change of frustule under heavy metals pollution as well as the differences in heavy metals biosorption and bioaccumulation by diatom, the ecological adaptation mechanisms of diatom on heavy metals surface complexation and ion exchange, and the roles of diatom as bio-indicator and in ecological restoration of heavy metals polluted water body were also discussed. This review could provide scientific evidences for the prevention of aquatic ecosystems heavy metals pollution and related early warning techniques.

Advances in liquid metal cooled ADS systems, and useful results for the design of IFMIF

International Nuclear Information System (INIS)

Massaut, V.; Debruyn, D.; Decreton, M.

2007-01-01

Full text of publication follows: Liquid metal cooled Accelerator Driven Systems (ADS) have a lot of design commonalities with the design of IFMIF. The use of a powerful accelerator and a liquid metal spallation source makes it similar to the main features of the IFMIF irradiator. Developments in the field of liquid metal ADS can thus be very useful for the design phase of IFMIF, and synergy between both domains should be enhanced to avoid dubbing work already done. The liquid metal ADS facilities are developed for testing materials under high fast (> 1 MeV) neutron flux, and also for studying the transmutation of actinides as foreseen in the P and T (Partitioning and Transmutation) strategy of future fission industry. The ADS are mostly constituted of a sub-critical fission fuel assembly matrix, a spallation source (situated at the centre of the fuel arrangement) and a powerful accelerator targeting the spallation source. In liquid metal ADS, the spallation source is a liquid metal (like Pb-Bi) which is actively cooled to remove the power generated by the particle beam, spallation reactions and neutrons. Based on an advanced ADS design (e.g. the MYRRHA/XT-ADS facility), the paper shows the various topics which are common for both facilities (ADS and IFMIF) and highlights their respective specificities, leading to focused R and D activities. This would certainly cover the common aspects related to high power accelerators, liquid metal targets and beam-target coupling. But problems of safety, radioprotection, source heating and cooling, neutrons shielding, etc... lead also to common features and developments. Results already obtained for the ADS development will illustrate this synergy. This paper will therefore allow to take profit of recent developments in both fission and fusion programs and enhance the collaboration among the R and D teams in both domains. (authors)

Advances in liquid metal cooled ADS systems, and useful results for the design of IFMIF

Energy Technology Data Exchange (ETDEWEB)

Massaut, V.; Debruyn, D. [SCK CEN, Mol (Belgium); Decreton, M. [Ghent Univ., Dept. of Applied Physics (Belgium)

2007-07-01

Full text of publication follows: Liquid metal cooled Accelerator Driven Systems (ADS) have a lot of design commonalities with the design of IFMIF. The use of a powerful accelerator and a liquid metal spallation source makes it similar to the main features of the IFMIF irradiator. Developments in the field of liquid metal ADS can thus be very useful for the design phase of IFMIF, and synergy between both domains should be enhanced to avoid dubbing work already done. The liquid metal ADS facilities are developed for testing materials under high fast (> 1 MeV) neutron flux, and also for studying the transmutation of actinides as foreseen in the P and T (Partitioning and Transmutation) strategy of future fission industry. The ADS are mostly constituted of a sub-critical fission fuel assembly matrix, a spallation source (situated at the centre of the fuel arrangement) and a powerful accelerator targeting the spallation source. In liquid metal ADS, the spallation source is a liquid metal (like Pb-Bi) which is actively cooled to remove the power generated by the particle beam, spallation reactions and neutrons. Based on an advanced ADS design (e.g. the MYRRHA/XT-ADS facility), the paper shows the various topics which are common for both facilities (ADS and IFMIF) and highlights their respective specificities, leading to focused R and D activities. This would certainly cover the common aspects related to high power accelerators, liquid metal targets and beam-target coupling. But problems of safety, radioprotection, source heating and cooling, neutrons shielding, etc... lead also to common features and developments. Results already obtained for the ADS development will illustrate this synergy. This paper will therefore allow to take profit of recent developments in both fission and fusion programs and enhance the collaboration among the R and D teams in both domains. (authors)

Performance and safety design of the advanced liquid metal reactor

International Nuclear Information System (INIS)

Berglund, R.C.; Magee, P.M.; Boardman, C.E.; Gyorey, G.L.

1991-01-01

The Advanced Liquid Metal Reactor (ALMR) program led by General Electric is developing, under U.S. Department of Energy sponsorship, a conceptual design for an advanced sodium-cooled liquid metal reactor plant. This design is intended to improve the already excellent level of plant safety achieved by the nuclear power industry while at the same time providing significant reductions in plant construction and operating costs. In this paper, the plant design and performance are reviewed, with emphasis on the ALMR's unique passive design safety features and its capability to utilize as fuel the actinides in LWR spent fuel

Screening test for rapid food safety evaluation by menadione-catalysed chemiluminescent assay.

Science.gov (United States)

Yamashoji, Shiro; Yoshikawa, Naoko; Kirihara, Masayuki; Tsuneyoshi, Toshihiro

2013-06-15

The chemiluminescent assay of menadione-catalysed H2O2 production by living mammalian cells was proposed to be useful for rapid food safety evaluation. The tested foods were extracted with water, ethanol and dimethylsulfoxide, and each extract was incubated with NIH3T3, Neuro-2a and HepG2 cells for 4h. Menadione-catalysed H2O2 production by living mammalian cells exposed to each extract was determined by the chemiluminescent assay requiring only 10 min, and the viability of the cells was estimated as percentage based on H2O2 production by intact cells. In this study the cytotoxicity of food was rated in order of inhibitory effect on H2O2 production by intact cells. The well known natural toxins such as Fusarium mycotoxin, tomato toxin tomatine, potato toxin solanine and marine toxins terodotoxin and brevetoxin could be detected by the above chemiluminescent assay. Copyright © 2012 Elsevier Ltd. All rights reserved.

A competitive chemiluminescence enzyme immunoassay for rapid and sensitive determination of enrofloxacin

Science.gov (United States)

Yu, Fei; Wu, Yongjun; Yu, Songcheng; Zhang, Huili; Zhang, Hongquan; Qu, Lingbo; Harrington, Peter de B.

With alkaline phosphatase (ALP)-adamantane (AMPPD) system as the chemiluminescence (CL) detection system, a highly sensitive, specific and simple competitive chemiluminescence enzyme immunoassay (CLEIA) was developed for the measurement of enrofloxacin (ENR). The physicochemical parameters, such as the chemiluminescent assay mediums, the dilution buffer of ENR-McAb, the volume of dilution buffer, the monoclonal antibody concentration, the incubation time, and other relevant variables of the immunoassay have been optimized. Under the optimal conditions, the detection linear range of 350-1000 pg/mL and the detection limit of 0.24 ng/mL were provided by the proposed method. The relative standard deviations were less than 15% for both intra and inter-assay precision. This method has been successfully applied to determine ENR in spiked samples with the recovery of 103%-96%. It showed that CLEIA was a good potential method in the analysis of residues of veterinary drugs after treatment of related diseases.

Flame structure of methane/oxygen shear coaxial jet with velocity ratio using high-speed imaging and OH*, CH* chemiluminescence

Science.gov (United States)

Shim, Myungbo; Noh, Kwanyoung; Yoon, Woongsup

2018-06-01

In this study, the effects of gaseous methane/oxygen injection velocity ratio on the shear coaxial jet flame structure are analyzed using high-speed imaging along with OH* and CH* chemiluminescence. The images show that, as the velocity ratio is increased, the visual flame length increases and wrinkles of the flame front are developed further downstream. The region near the equivalence ratio 1 condition in the flame could be identified by the maximum OH* position, and this region is located further downstream as the velocity ratio is increased. The dominant CH* chemiluminescence is found in the near-injector region. As the velocity ratio is decreased, the signal intensity is higher at the same downstream distance in each flame. From the results, as the velocity ratio is decreased, there is increased entrainment of the external jet, the mixing of the two jets is enhanced, the region near the stoichiometric mixture condition is located further upstream, and consequently, the flame length decreases.

Dual-peak electrogenerated chemiluminescence of carbon dots for iron ions detection.

Science.gov (United States)

Zhang, Pengjia; Xue, Zhenjie; Luo, Dan; Yu, Wei; Guo, Zhihui; Wang, Tie

2014-06-17

Carbon dots (CDs) have rigorously been investigated on their unique fluorescent properties but rarely their electrogenerated chemiluminescence (ECL) behavior. We are here to report a dual-peak ECL system of CDs, one at -2.84 V (ECL-1) and the other at -1.71 V (ECL-2) during the cyclic sweep between -3.0 and 3.0 V at scan rate of 0.2 V s(-1) in 0.1 M tetrabutyl ammonium bromide (TBAB) ethanol solution, which is more efficiency to distinguish metallic ions than single-peak ECL. The electron transfer reaction between individual electrochemically reduced nanocrystal species and coreactants led to ECL-1, in which the electron injected to the conduction band of CDs in the cathodic process. Ion annihilation reactions induced direct formation of exciplexes that produced another ECL signal, ECL-2. ECL-1 showed higher sensitivity to the surrounding environment than ECL-2 and thus was used for ECL detection of metallic ions. Herein, we can serve as an internal standard method to detect iron ions. A linear relationship of the intensity ratio R of ECL-1 and ECL-2 to iron ions was observed in the concentration extending from 5 × 10(-6) to 8 × 10(-5) M with a detection limit of 7 × 10(-7) M.

Enhancing CO2 Electroreduction with the Metal-Oxide Interface.

Science.gov (United States)

Gao, Dunfeng; Zhang, Yi; Zhou, Zhiwen; Cai, Fan; Zhao, Xinfei; Huang, Wugen; Li, Yangsheng; Zhu, Junfa; Liu, Ping; Yang, Fan; Wang, Guoxiong; Bao, Xinhe

2017-04-26

The electrochemical CO 2 reduction reaction (CO 2 RR) typically uses transition metals as the catalysts. To improve the efficiency, tremendous efforts have been dedicated to tuning the morphology, size, and structure of metal catalysts and employing electrolytes that enhance the adsorption of CO 2 . We report here a strategy to enhance CO 2 RR by constructing the metal-oxide interface. We demonstrate that Au-CeO x shows much higher activity and Faradaic efficiency than Au or CeO x alone for CO 2 RR. In situ scanning tunneling microscopy and synchrotron-radiation photoemission spectroscopy show that the Au-CeO x interface is dominant in enhancing CO 2 adsorption and activation, which can be further promoted by the presence of hydroxyl groups. Density functional theory calculations indicate that the Au-CeO x interface is the active site for CO 2 activation and the reduction to CO, where the synergy between Au and CeO x promotes the stability of key carboxyl intermediate (*COOH) and thus facilitates CO 2 RR. Similar interface-enhanced CO 2 RR is further observed on Ag-CeO x , demonstrating the generality of the strategy for enhancing CO 2 RR.

Detection of gamma irradiated pepper and papain by chemiluminescence

International Nuclear Information System (INIS)

Sattar, Abdus; Delincee, H.; Diehl, J.F.

1987-01-01

Chemiluminescence (CL) measurements of black pepper and of papain using luminol and lucigenin reactions were studied. Effects of grinding, irradiation (5-20 kGy) and particle size (750-140 μm) on CL of pepper, and of irradiation (10-30 kGy) on CL of papain, were investigated. All the tested treatments affected the luminescence response in both the luminol and lucigenin reactions; however, the pattern of changes in each case, was inconsistent. Optimum pepper size for maximum luminescence was 560 μm, and optimum irradiation doses were > 15 kGy for pepper and > 20 kGy for papain. Chemiluminescence may possibly be used as an indicator or irradiation treatment for pepper and papain at a dose of 10 kGy or higher, but further research is needed to establish the reliability of this method. (author)

Ion implantation enhanced metal-Si-metal photodetectors

Science.gov (United States)

Sharma, A. K.; Scott, K. A. M.; Brueck, S. R. J.; Zolper, J. C.; Myers, D. R.

1994-05-01

The quantum efficiency and frequency response of simple Ni-Si-Ni metal-semiconductor-metal (MSM) photodetectors at long wavelengths are significantly enhanced with a simple, ion-implantation step to create a highly absorbing region approx. 1 micron below the Si surface. The internal quantum efficiency is improved by a factor of approx. 3 at 860 nm (to 64%) and a full factor of ten at 1.06 microns (to 23%) as compared with otherwise identical unimplanted devices. Dark currents are only slightly affected by the implantation process and are as low as 630 pA for a 4.5-micron gap device at 10-V bias. Dramatic improvement in the impulse response is observed, 100 ps vs. 600 ps, also at 10-V bias and 4.5-micron gap, due to the elimination of carrier diffusion tails in the implanted devices. Due to its planar structure, this device is fully VLSI compatible. Potential applications include optical interconnections for local area networks and multi-chip modules.

Metal nanoinks as chemically stable surface enhanced scattering (SERS) probes for the analysis of blue BIC ballpoint pens.

Science.gov (United States)

Alyami, A; Saviello, D; McAuliffe, M A P; Mirabile, A; Lewis, L; Iacopino, D

2017-06-07

Metal nanoinks constituted by Ag nanoparticles and Au nanorods were employed as probes for the Surface Enhanced Raman Scattering (SERS) analysis of a blue BIC ballpoint pen. The dye components of the pen ink were first separated by thin layer chromatography (TLC) and subsequently analysed by SERS at illumination wavelengths of 514 nm and 785 nm. Compared to normal Raman conditions, enhanced spectra were obtained for all separated spots, allowing easy identification of phthalocyanine Blue 38 and triarylene crystal violet in the ink mixture. A combination of effects such as molecular resonance, electromagnetic and chemical effects were the contributing factors to the generation of spectra enhanced compared to normal Raman conditions. Enhancement factors (EFs) between 5 × 10 3 and 3 × 10 6 were obtained, depending on the combination of SERS probes and laser illumination used. In contrast to previous conflicting reports, the metal nanoinks were chemically stable, allowing the collection of reproducible spectra for days after deposition on TLC plates. In addition and in advance to previously reported SERS probes, no need for additional aggregating agents or correction of electrostatic charge was necessary to induce the generation of enhanced SERS spectra.

Analysis of chemiluminescence measurements by grey-scale ICCD and colour digital cameras

International Nuclear Information System (INIS)

Migliorini, F; Maffi, S; De Iuliis, S; Zizak, G

2014-01-01

Spectral, grey-scale and colour chemiluminescence measurements of C 2 * and CH* radicals' emission are carried out on the flame front of a methane–air premixed flame at different equivalence ratios. To this purpose, properly spatially resolved optical equipment has been implemented in order to reduce the background emission from other burned gas regions. The grey-scale (ICCD + interference filters) and RGB colour (commercial digital camera) approaches have been compared in order to find a correspondence between the C 2 * and the green component, as well as the CH* and the blue component of the emission intensities. The C 2 */CH* chemiluminescence ratio has been investigated at different equivalence ratios and a good correlation has been obtained, showing the possibility of sensing the equivalence ratio in practical systems. The grey-scale and colour chemiluminescence analysis has then been applied to a meso-scale not premixed swirl combustor fuelled with a methane–air mixture and operating at 0.3 MPa. 2D results are presented and discussed in this work. (paper)

Gold nanodisc arrays as near infrared metal-enhanced fluorescence platforms with tuneable enhancement factors

KAUST Repository

Pang, J.; Theodorou, I. G.; Centeno, A.; Petrov, P. K.; Alford, N. M.; Ryan, M. P.; Xie, F.

2016-01-01

Metal enhanced fluorescence (MEF) is a physical effect through which the near-field interaction of fluorophores with metallic nanoparticles can lead to large fluorescence enhancement. MEF can be exploited in many fluorescence-based biomedical applications, with potentially significant improvement in detection sensitivity and contrast enhancement. Offering lower autofluorescence and minimal photoinduced damage, the development of effective and multifunctional MEF platforms in the near-infrared (NIR) region, is particularly desirable. In this work, the enhancement of NIR fluorescence caused by interaction with regular arrays of cylindrical gold (Au) nanoparticles (nanodiscs), fabricated through nanosphere lithography, is reported. Significant MEF of up to 235 times is obtained, with tuneable enhancement factors. The effect of array structure on fluorescence enhancement is investigated by semi-quantitatively de-convoluting excitation enhancement from emission enhancement, and modelling the local electric field enhancement. By considering arrays of Au nanodiscs with the same extinction maximum, it is shown that the excitation enhancement, due to increased electric field, is not significantly different for the particle sizes and separation distances considered. Rather, it is seen that the emission from the fluorophore is strongly enhanced, and is dependent on the topography, in particular particle size. The results show that the structural characteristics of Au nanodisc arrays can be manipulated to tune their enhancement factor, and hence their sensitivity.

Gold nanodisc arrays as near infrared metal-enhanced fluorescence platforms with tuneable enhancement factors

KAUST Repository

Pang, J.

2016-12-28

Metal enhanced fluorescence (MEF) is a physical effect through which the near-field interaction of fluorophores with metallic nanoparticles can lead to large fluorescence enhancement. MEF can be exploited in many fluorescence-based biomedical applications, with potentially significant improvement in detection sensitivity and contrast enhancement. Offering lower autofluorescence and minimal photoinduced damage, the development of effective and multifunctional MEF platforms in the near-infrared (NIR) region, is particularly desirable. In this work, the enhancement of NIR fluorescence caused by interaction with regular arrays of cylindrical gold (Au) nanoparticles (nanodiscs), fabricated through nanosphere lithography, is reported. Significant MEF of up to 235 times is obtained, with tuneable enhancement factors. The effect of array structure on fluorescence enhancement is investigated by semi-quantitatively de-convoluting excitation enhancement from emission enhancement, and modelling the local electric field enhancement. By considering arrays of Au nanodiscs with the same extinction maximum, it is shown that the excitation enhancement, due to increased electric field, is not significantly different for the particle sizes and separation distances considered. Rather, it is seen that the emission from the fluorophore is strongly enhanced, and is dependent on the topography, in particular particle size. The results show that the structural characteristics of Au nanodisc arrays can be manipulated to tune their enhancement factor, and hence their sensitivity.

Advanced Modelling of Trusses with Punched Metal Plate Fasteners

DEFF Research Database (Denmark)

Ellegaard, Peter; Nielsen, Jacob

Most of the finite element programs for design of timber trusses with punched metal fasteners are based on models using beam and fictitious elements. Different models have been used for different types of joints. Common problems for all the models are how to calculate the forces in the nail groups...... and the plates and furthermore, how big 'the deformations in the joints are. By developing an advanced model that includes all parts of the joint, i.e. plate, nail groups and contact it is possible to give a better description of the joint. An advanced model with these properties is presented. The advanced model...

Observation of chemiluminescence induced by hydrodynamic cavitation in microchannels.

Science.gov (United States)

Podbevsek, D; Colombet, D; Ledoux, G; Ayela, F

2018-05-01

We have performed hydrodynamic cavitation experiments with an aqueous luminol solution as the working fluid. Light emission, together with the high frequency noise which characterizes cavitation, was emitted by the two-phase flow, whereas no light emission from luminol was recorded in the single phase liquid flow. Light emission occurs downstream transparent microdiaphragms. The maximum level of the recorded signal was around 180 photons per second with flow rates of 380 µl/s, that corresponds to a real order of magnitude of the chemiluminescence of 75,000 photons per second. The yield of emitted photons increases linearly with the pressure drop, which is proportional to the square of the total flow rate. Chemiluminescence of luminol is a direct and a quantitative demonstration of the presence of OH hydroxyl radicals created by hydrodynamic cavitation. The presented method could be a key to optimize channel geometry for processes where radical production is essential. Copyright © 2018 Elsevier B.V. All rights reserved.

Metals as radio-enhancers in oncology: The industry perspective

Energy Technology Data Exchange (ETDEWEB)

Pottier, Agnés, E-mail: agnes.pottier@nanobiotix.com; Borghi, Elsa; Levy, Laurent

2015-12-18

Radio-enhancers, metal-based nanosized agents, could play a key role in oncology. They may unlock the potential of radiotherapy by enhancing the radiation dose deposit within tumors when the ionizing radiation source is ‘on’, while exhibiting chemically inert behavior in cellular and subcellular systems when the radiation beam is ‘off’. Important decision points support the development of these new type of therapeutic agents originated from nanotechnology. Here, we discuss from an industry perspective, the interest of developing radio-enhancer agents to improve tumor control, the relevance of nanotechnology to achieve adequate therapeutic attributes, and present some considerations for their development in oncology. - Highlights: • Oncology is a field of high unmet medical need. • Despites of its widespread usage, radiation therapy presents a narrow therapeutic window. • High density material at the nanoscale may enhance radiation dose deposit from cancer cells. • Metal-based nanosized radio-enhancers could unlock the potential of radiotherapy.

An enhanced cerium(IV)-rhodamine 6G chemiluminescence system using guest-host interactions in a lab-on-a-chip platform for estimating the total phenolic content in food samples.

Science.gov (United States)

Al Haddabi, Buthaina; Al Lawati, Haider A J; Suliman, FakhrEldin O

2016-04-01

Two chemiluminescence-microfluidic (CL-MF) systems, e.g., Ce(IV)-rhodamine B (RB) and Ce(IV)-rhodamine 6G (R6G), for the determination of the total phenolic content in teas and some sweeteners were evaluated. The results indicated that the Ce(IV)-R6G system was more sensitive in comparison to the Ce(IV)-RB CL system. Therefore, a simple (CL-MF) method based on the CL of Ce(IV)-R6G was developed, and the sensitivity, selectivity and stability of this system were evaluated. Selected phenolic compounds (PCs), such as quercetin (QRC), catechin (CAT), rutin (RUT), gallic acid (GA), caffeic acid (CA) and syringic acid (SA), produced analytically useful chemiluminescence signals with low detection limits ranging from 0.35 nmol L(-1) for QRC to 11.31 nmol L(-1) for SA. The mixing sequence and the chip design were crucial, as the sensitivity and reproducibility could be substantially affected by these two factors. In addition, the anionic surfactant (i.e., sodium dodecyl sulfate (SDS)) can significantly enhance the CL signal intensity by as much as 300% for the QRC solution. Spectroscopic studies indicated that the enhancement was due to a strong guest-host interaction between the cationic R6G molecules and the anionic amphiphilic environment. Other parameters that could affect the CL intensities of the PCs were carefully optimized. Finally, the method was successfully applied to tea and sweetener samples. Six different tea samples exhibited total phenolic/antioxidant levels from 7.32 to 13.5 g per 100g of sample with respect to GA. Four different sweetener samples were also analyzed and exhibited total phenolic/antioxidant levels from 500.9 to 3422.9 mg kg(-1) with respect to GA. The method was selective, rapid and sensitive when used to estimate the total phenolic/antioxidant level, and the results were in good agreement with those reported for honey and tea samples. Copyright © 2015 Elsevier B.V. All rights reserved.

Comparison of ultraviolet absorbance and NO-chemiluminescence for ozone measurement in wildfire plumes at the Mount Bachelor Observatory

Science.gov (United States)

Gao, Honglian; Jaffe, Daniel A.

2017-10-01

The goal of this paper is to evaluate the accuracy of the commonly used ozone (O3) instrument (the ultraviolet (UV) photometer) against a Federal Reference Method (Nitric Oxide -chemiluminescence) for ozone measurement in wildfire smoke plumes. We carried out simultaneous ozone measurement with two UV O3 photometers and one nitric oxide-chemiluminescence (NO-CL) ozone detectors during wildfire season (Aug. 1-Sept. 30) in 2015 at the Mount Bachelor Observatory (MBO, 2763 m above mean sea level, Oregon, USA). The UV O3 shows good agreement and excellent correlation to NO-CL O3, with linear regression slopes close to unity and R2 of 0.92 for 1-h average data and R2 of 0.93 for O3 daily maximum 8-h average (MDA8). During this two-month period we identified 35 wildfire events. Ozone enhancements in those wildfire plumes measured by NO-CL O3 and UV O3 monitors also show good agreement and excellent linear correlation, with a slope and R2 of 1.03 and 0.86 for O3 enhancements (ΔO3) and 1.00 and 0.98 for carbon monoxide (CO)-normalized ozone enhancement ratios (ΔO3/ΔCO), respectively. Overall, the UV O3 was found to have a positive bias of 4.7 ± 2.8 ppbv compared to the NO-CL O3. The O3 bias between NO-CL O3 and UV O3 is independent of wildfire plume tracers such as CO, particulate matter (PM1), aerosol scattering, and ultrafine particles. The results demonstrate that the UV O3 absorbance method is reliable, even in highly concentrated wildfire plumes.

Engineering Metallic Nanoparticles for Enhancing and Probing Catalytic Reactions.

Science.gov (United States)

Collins, Gillian; Holmes, Justin D

2016-07-01

Recent developments in tailoring the structural and chemical properties of colloidal metal nanoparticles (NPs) have led to significant enhancements in catalyst performance. Controllable colloidal synthesis has also allowed tailor-made NPs to serve as mechanistic probes for catalytic processes. The innovative use of colloidal NPs to gain fundamental insights into catalytic function will be highlighted across a variety of catalytic and electrocatalytic applications. The engineering of future heterogenous catalysts is also moving beyond size, shape and composition considerations. Advancements in understanding structure-property relationships have enabled incorporation of complex features such as tuning surface strain to influence the behavior of catalytic NPs. Exploiting plasmonic properties and altering colloidal surface chemistry through functionalization are also emerging as important areas for rational design of catalytic NPs. This news article will highlight the key developments and challenges to the future design of catalytic NPs. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Projection model for flame chemiluminescence tomography based on lens imaging

Science.gov (United States)

Wan, Minggang; Zhuang, Jihui

2018-04-01

For flame chemiluminescence tomography (FCT) based on lens imaging, the projection model is essential because it formulates the mathematical relation between the flame projections captured by cameras and the chemiluminescence field, and, through this relation, the field is reconstructed. This work proposed the blurry-spot (BS) model, which takes more universal assumptions and has higher accuracy than the widely applied line-of-sight model. By combining the geometrical camera model and the thin-lens equation, the BS model takes into account perspective effect of the camera lens; by combining ray-tracing technique and Monte Carlo simulation, it also considers inhomogeneous distribution of captured radiance on the image plane. Performance of these two models in FCT was numerically compared, and results showed that using the BS model could lead to better reconstruction quality in wider application ranges.

Numerical and Experimental Investigation of Computed Tomography of Chemiluminescence for Hydrogen-Air Premixed Laminar Flames

Directory of Open Access Journals (Sweden)

Liang Lv

2016-01-01

Full Text Available Computed tomography of chemiluminescence (CTC is a promising technique for combustion diagnostics, providing instantaneous 3D information of flame structures, especially in harsh circumstance. This work focuses on assessing the feasibility of CTC and investigating structures of hydrogen-air premixed laminar flames using CTC. A numerical phantom study was performed to assess the accuracy of the reconstruction algorithm. A well-designed burner was used to generate stable hydrogen-air premixed laminar flames. The OH⁎ chemiluminescence intensity field reconstructed from 37 views using CTC was compared to the OH⁎ chemiluminescence distributions recorded directly by a single ICCD camera from the side view. The flame structures in different flow velocities and equivalence ratios were analyzed using the reconstructions. The results show that the CTC technique can effectively indicate real distributions of the flame chemiluminescence. The height of the flame becomes larger with increasing flow velocities, whereas it decreases with increasing equivalence ratios (no larger than 1. The increasing flow velocities gradually lift the flame reaction zones. A critical cone angle of 4.76 degrees is obtained to avoid blow-off. These results set up a foundation for next studies and the methods can be further developed to reconstruct 3D structures of flames.

3D metal droplet printing development and advanced materials additive manufacturing

Directory of Open Access Journals (Sweden)

Lawrence E. Murr

2017-01-01

Full Text Available While commercial additive manufacturing processes involving direct metal wire or powder deposition along with powder bed fusion technologies using laser and electron beam melting have proliferated over the past decade, inkjet printing using molten metal droplets for direct, 3D printing has been elusive. In this paper we review the more than three decades of development of metal droplet generation for precision additive manufacturing applications utilizing advanced, high-temperature metals and alloys. Issues concerning process optimization, including product structure and properties affected by oxidation are discussed and some comparisons of related additive manufactured microstructures are presented.

Development of Korea advanced liquid metal reactor

International Nuclear Information System (INIS)

Park, C.K.

1998-01-01

Future nuclear power plants should not only have the features of improved safety and economic competitiveness but also provide a means to resolve spent fuel storage problems by minimizing volume of high level wastes. It is widely believed that liquid metal reactors (LMRs) have the highest potential of meeting these requirements. In this context, the LMR development program was launched as a national long-term R and D program in 1992, with a target to introduce a commercial LMR around 2030. Korea Advanced Liquid Metal Reactor (KALIMER), a 150 MWe pool-type sodium cooled prototype reactor, is currently under the conceptual design study with the target schedule to complete its construction by the mid-2010s. This paper summarizes the KALIMER development program and major technical features of the reactor system. (author)

Plasticity enhancement mechanisms in refractory metals and intermetallics

International Nuclear Information System (INIS)

Gibala, R.; Chang, H.; Czarnik, C.M.; Edwards, K.M.; Misra, A.

1993-01-01

Plasticity enhancement associated with surface films and precipitates or dispersoids in bcc refractory metals is operative in ordered intermetallic compounds. Some results are given for NiAl and MoSi 2 -based materials. The monotonic and cyclic plasticity of NiAl at room temperature can be enhanced by surface films. Ductile second phases also enhance the plasticity of NiAl. MoSi 2 exhibits similar effects of surface films and dispersoids, but primarily at elevated temperatures. The plasticity enhancement is associated with enhanced dislocation generation from constrained deformation at the film-substrate or precipitate/dispersoid-matrix interface of the composite systems

Multiple layered metallic nanostructures for strong surface-enhanced Raman spectroscopy enhancement

International Nuclear Information System (INIS)

Xia, Ming; Xie, Ya-Hong; Qiao Kuan; Cheng Zhiyuan

2016-01-01

We report a systematic study on a practical way of patterning metallic nanostructures to achieve high surface-enhanced Raman spectroscopy (SERS) enhancement factors (EFs) and high hot-spot density. By simply superimposing a 1-layer Au nanotriangle array on another to form a multilayer nanotriangle array, the SERS signal can be enhanced by 2 orders of magnitude compared with a 1-layer nanotriangle array. The drastic increases in the SERS EF and the hot spot density of the multilayer Au nanotriangle array are due to the increase in the number of gaps formed between Au nanotriangles and the decrease of the gap width. (author)

Plasmon-enhanced fluorescence near nonlocal metallic nanospheres

DEFF Research Database (Denmark)

Tserkezis, Christos; Stefanou, N.; Wubs, Martijn

Spontaneous emission and fluorescence of organic molecules are known to strongly depend on the local electromagnetic environment. Plasmonic nanoparticles are widely explored as templates for controlling light-matter interactions, and can be tailored to optimize the fluorescence rate (Ȗem......) and the generalized nonlocal optical response (GNOR) theory [2] shows that a significant decrease in fluorescence enhancement is obtained for emitters close to small metallic nanospheres or thin metallic nanoshells, while the optimum emitter position is also affected. In this respect, our recent work introduces...

Enhanced X-ray yields in PIXE analysis of some binary metal fluorides

International Nuclear Information System (INIS)

Peisach, M.; Pineda, C.A.; Pillay, A.E.

1993-01-01

Enhanced X-ray yields from the metal components of homogeneous thick targets of binary metal fluorides were observed during PIXE irradiations with protons, deuterons and 3 He ions. The absence of these effects in the pure metals and in the corresponding metal oxides, nitrides and borides suggests that the fluoride component in such compounds plays a key role in producing the enhancement. Coulomb excitation of the extremely low-lying levels of the fluorine nucleus is discussed as a possible mechanism for the improved yields via secondary excitation. (orig.)

Smart electrochemical biosensors: From advanced materials to ultrasensitive devices

Energy Technology Data Exchange (ETDEWEB)

Sadik, Omowunmi A., E-mail: osadik@binghamton.ed [Department of Chemistry, Center for Advanced Sensors and Environmental Monitoring (CASE), State University of New York-Binghamton, P.O. Box 6000, Binghamton, NY 13902 (United States); Mwilu, Samuel K.; Aluoch, Austin [Department of Chemistry, Center for Advanced Sensors and Environmental Monitoring (CASE), State University of New York-Binghamton, P.O. Box 6000, Binghamton, NY 13902 (United States)

2010-05-30

The specificity, simplicity, and inherent miniaturization afforded by advances in modern electronics have allowed electrochemical sensors to rival the most advanced optical protocols. One major obstacle in implementing electrochemistry for studying biomolecular reaction is its inadequate sensitivity. Recent reports however showed unprecedented sensitivities for biomolecular recognition using enhanced electronic amplification provided by new classes of electrode materials (e.g. carbon nanotubes, metal nanoparticles, and quantum dots). Biosensor technology is one area where recent advances in nanomaterials are pushing the technological limits of electrochemical sensitivities, thus allowing for the development of new sensor chemistries and devices. This work focuses on our recent work, based on metal-enhanced electrochemical detection, and those of others in combining advanced nanomaterials with electrochemistry for the development of smart sensors for proteins, nucleic acids, drugs and cancer cells.

Smart electrochemical biosensors: From advanced materials to ultrasensitive devices

International Nuclear Information System (INIS)

Sadik, Omowunmi A.; Mwilu, Samuel K.; Aluoch, Austin

2010-01-01

The specificity, simplicity, and inherent miniaturization afforded by advances in modern electronics have allowed electrochemical sensors to rival the most advanced optical protocols. One major obstacle in implementing electrochemistry for studying biomolecular reaction is its inadequate sensitivity. Recent reports however showed unprecedented sensitivities for biomolecular recognition using enhanced electronic amplification provided by new classes of electrode materials (e.g. carbon nanotubes, metal nanoparticles, and quantum dots). Biosensor technology is one area where recent advances in nanomaterials are pushing the technological limits of electrochemical sensitivities, thus allowing for the development of new sensor chemistries and devices. This work focuses on our recent work, based on metal-enhanced electrochemical detection, and those of others in combining advanced nanomaterials with electrochemistry for the development of smart sensors for proteins, nucleic acids, drugs and cancer cells.

Allotropic Carbon Nanoforms as Advanced Metal-Free Catalysts or as Supports

Directory of Open Access Journals (Sweden)

Hermenegildo Garcia

2014-01-01

Full Text Available This perspective paper summarizes the use of three nanostructured carbon allotropes as metal-free catalysts (“carbocatalysts” or as supports of metal nanoparticles. After an introductory section commenting the interest of developing metal-free catalysts and main features of carbon nanoforms, the main body of this paper is focused on exemplifying the opportunities that carbon nanotubes, graphene, and diamond nanoparticles offer to develop advanced catalysts having active sites based on carbon in the absence of transition metals or as large area supports with special morphology and unique properties. The final section provides my personal view on future developments in this field.

Chemiluminescence in cryogenic matrices

Science.gov (United States)

Lotnik, S. V.; Kazakov, Valeri P.

1989-04-01

The literature data on chemiluminescence (CL) in cryogenic matrices have been classified and correlated for the first time. The role of studies on phosphorescence and CL at low temperatures in the development of cryochemistry is shown. The features of low-temperature CL in matrices of nitrogen and inert gases (fine structure of spectra, matrix effects) and the data on the mobility and reactivity of atoms and radicals at very low temperatures are examined. The trends in the development of studies on CL in cryogenic matrices, such as the search for systems involving polyatomic molecules and extending the forms of CL reactions, are followed. The reactions of active nitrogen with hydrocarbons that are accompanied by light emission and CL in the oxidation of carbenes at T >= 77 K are examined. The bibliography includes 112 references.

[Heavy metal pollution ecology of macro-fungi: research advances and expectation].

Science.gov (United States)

Zhou, Qi-xing; An, Xin-long; Wei, Shu-he

2008-08-01

Macro-fungi are the main component of biosphere and one of the ecological resources, and play very important roles in matter cycling and in maintaining ecological balances. This paper summarized and reviewed the research advances in the eco-toxicological effects of heavy metals on macro-fungi, the bioaccumulation function of macro-fungi on heavy metals, the ecological adaptation mechanisms of macro-fungi to heavy metal pollution, the role of macro-fungi as a bio-indicator of heavy metal pollution, and the potential of macro-fungi in the ecological remediation of contaminated environment. To strengthen the researches on the heavy metal pollution ecology of macro-fungi would be of practical significance in the reasonable utilization of macro-fungi resources and in the ecological remediation of contaminated environment.

Metal fires and their implications for advanced reactors.

Energy Technology Data Exchange (ETDEWEB)

Nowlen, Steven Patrick; Figueroa, Victor G.; Olivier, Tara Jean; Hewson, John C.; Blanchat, Thomas K.

2010-10-01

This report details the primary results of the Laboratory Directed Research and Development project (LDRD 08-0857) Metal Fires and Their Implications for Advance Reactors. Advanced reactors may employ liquid metal coolants, typically sodium, because of their many desirable qualities. This project addressed some of the significant challenges associated with the use of liquid metal coolants, primary among these being the extremely rapid oxidation (combustion) that occurs at the high operating temperatures in reactors. The project has identified a number of areas for which gaps existed in knowledge pertinent to reactor safety analyses. Experimental and analysis capabilities were developed in these areas to varying degrees. In conjunction with team participation in a DOE gap analysis panel, focus was on the oxidation of spilled sodium on thermally massive surfaces. These are spills onto surfaces that substantially cool the sodium during the oxidation process, and they are relevant because standard risk mitigation procedures seek to move spill environments into this regime through rapid draining of spilled sodium. While the spilled sodium is not quenched, the burning mode is different in that there is a transition to a smoldering mode that has not been comprehensively described previously. Prior work has described spilled sodium as a pool fire, but there is a crucial, experimentally-observed transition to a smoldering mode of oxidation. A series of experimental measurements have comprehensively described the thermal evolution of this type of sodium fire for the first time. A new physics-based model has been developed that also predicts the thermal evolution of this type of sodium fire for the first time. The model introduces smoldering oxidation through porous oxide layers to go beyond traditional pool fire analyses that have been carried out previously in order to predict experimentally observed trends. Combined, these developments add significantly to the safety

Enhanced chemiluminescence of the luminol–KMnO4 system by CuO nanosheets and its application for determination of meropenem in water and human serum

International Nuclear Information System (INIS)

Khataee, A.R.; Fathinia, M.; Hasanzadeh, A.; Iranifam, M.; Moradkhannejhad, L.

2014-01-01

CuO nanosheets were synthesized by an easy and green sonochemical method. It was found that, CuO nanosheets could significantly catalyze the chemiluminescence (CL) reaction of luminol–KMnO 4 in an alkaline condition. Based on this finding, a new CL system (luminol–KMnO 4 –CuO nanosheets) combined with flow injection analysis has been developed for the determination of meropenem for the first time. Moreover, the CL intensity was enhanced when meropenem was presented in the reaction system. Under the optimum conditions, the enhanced CL intensity was proportional to the concentration of meropenem in the ranges of 0.005–6.00 mg L −1 , with a detection limit (3σ) of 0.0036 mg L −1 . The precision of the method was calculated by analyzing samples containing 1.0 mg L −1 meropenem (n=11) and the relative standard deviation (RSD) was 1.7%. Also, a total analysis time per sample was 30 s which confirmed the rapidity of the proposed assay. The practicality of the proposed CL system was evaluated by determining meropenem in spiked environmental water samples and human serum. A discussion on the possible CL reaction mechanism was also presented. - Highlights: • CuO nanosheets (NSs) were successfully prepared by a green sonochemical method. • CuO NSs were found to be an excellent enhancer for luminol−KMnO 4 CL system. • Meropenem was determined using a novel luminol−KMnO 4 −CuO NSs flow injection CL system. • The enhancement mechanism of meropenem on the CL emission was proposed. • Appropriate sensitivity and selectivity were notable features of the proposed method

Eco-friendly synthesis of gelatin-capped bimetallic Au-Ag nanoparticles for chemiluminescence detection of anticancer raloxifene hydrochloride.

Science.gov (United States)

Alarfaj, Nawal A; El-Tohamy, Maha F

2016-09-01

This study described the utility of green analytical chemistry in the synthesis of gelatin-capped silver, gold and bimetallic gold-silver nanoparticles (NPs). The preparation of nanoparticles was based on the reaction of silver nitrate or chlorauric acid with a 1.0 wt% aqueous gelatin solution at 50°C. The gelatin-capped silver, gold and bimetallic NPs were characterized using transmission electron microscopy, UV-vis, X-ray diffraction and Fourier transform infrared spectroscopy, and were used to enhance a sensitive sequential injection chemiluminescence luminol-potassium ferricyanide system for determination of the anticancer drug raloxifene hydrochloride. The developed method is eco-friendly and sensitive for chemiluminescence detection of the selected drug in its bulk powder, pharmaceutical injections and biosamples. After optimizing the conditions, a linear relationship in the range of 1.0 × 10(-9) to 1.0 × 10(-1)  mol/L was obtained with a limit of detection of 5.0 × 10(-10)  mol/L and a limit of quantification of 1.0 × 10(-9)  mol/L. Statistical treatment and method validation were performed based on ICH guidelines. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Spontaneous Emission Enhancement at Finite-length Metal

DEFF Research Database (Denmark)

Filonenko, K.; Willatzen, Morten; Bordo, V.

2013-01-01

We study spontaneous emission enhancement of a two-level atomic emitter placed in a dielectric medium near a finite-length cylindrical metal nanowire. We calculate the dependence of the Purcell factor and the normalized decay rate to a continuous spectrum on the nanowire radius for several emitter...

The path to the enhanced and advanced LIGO gravitational-wave detectors

International Nuclear Information System (INIS)

Smith, J R

2009-01-01

We report on the status of the Laser Interferometric Gravitational-Wave Observatory (LIGO) and the plans and progress toward Enhanced and Advanced LIGO. The initial LIGO detectors have finished a two-year long data run during which a full year of triple-coincidence data was collected at design sensitivity. Much of this run was also coincident with the data runs of interferometers in Europe, GEO600 and Virgo. The joint analysis of data from this international network of detectors is ongoing. No gravitational wave signals have been detected in analyses completed to date. Currently two of the LIGO detectors are being upgraded to increase their sensitivity in a program called Enhanced LIGO. The Enhanced LIGO detectors will start another roughly one-year long data run with increased sensitivity in 2009. In parallel, construction of Advanced LIGO, a major upgrade to LIGO, has begun. Installation and commissioning of Advanced LIGO hardware at the LIGO sites will commence at the end of the Enhanced LIGO data run in 2011. When fully commissioned, the Advanced LIGO detectors will be ten times as sensitive as the initial LIGO detectors. Advanced LIGO is expected to make several gravitational-wave detections per year.

Enhanced metal recovery through oxidation in liquid and/or supercritical carbon dioxide

KAUST Repository

Blanco, Mario; Buttner, Ulrich

2017-01-01

Process for enhanced metal recovery from, for example, metal-containing feedstock using liquid and/or supercritical fluid carbon dioxide and a source of oxidation. The oxidation agent can be free of complexing agent. The metal-containing feedstock

Carbon-enhanced metal-poor stars in dwarf galaxies

OpenAIRE

Salvadori, Stefania; Skuladottir, Asa; Tolstoy, Eline

2015-01-01

We investigate the frequency and origin of carbon-enhanced metal-poor (CEMP) stars in Local Group dwarf galaxies by means of a statistical, data-calibrated cosmological model for the hierarchical build-up of the Milky Way and its dwarf satellites. The model self-consistently explains the variation with dwarf galaxy luminosity of the observed: i) frequency and [Fe/H] range of CEMP stars; ii) metallicity distribution functions; iii) star formation histories. We show that if primordial faint sup...

Reaction of uranium (IV) with xenon difluoride by chemiluminescence, spectrophotometric, and spectrofluorimetric methods

Energy Technology Data Exchange (ETDEWEB)

Mamykin, A.V.; Kazakov, V.P.

1988-07-01

A study is made of the kinetics of the chemiluminescent reaction of oxidation of uranium (IV) by xenon difluoride in 1M HClO/sub 4/ U/sup 4 +/ + XeF/sub 2/ ..-->.. UO/sub 2//sup 2 +/ = h/eta/. The optical density D and the intensity of the photoluminescence of the solution I/sub PL/ were measured in parallel with recording of the luminescence intensity I/sub CL/. I/sub CL/ attains a maximum value some time after the beginning of the reaction, after which it decays exponentially. On the kinetic curves of the time dependence of D and I/sub PL/ an induction period is observed, the extent of which depends on concentrations of reagents and temperature of the solution. The maximum of I/sub CL/ coincides with the end of the induction period if the measurements are carried out under identical conditions. The rate of the reaction after the induction period is described by a first order equation in U/sup (IV)/. The rate constants of the reaction, obtained by chemiluminescence, spectrophotometric, and spectrofluorimetric methods, have close values 2.0 +- 0.4, 1.8 +- 0.3, and 2.1 +- 0.3 sec/sup /minus/1/ x 10/sup 2/, respectively. On the basis of the results obtained, we conclude that the stages of formation of UO/sub 2//sup 2 +/ and of chemiluminescence coincide, i.e., formation of the excited state (UD/sub 2//sup 2 +/) and of chemiluminescence coincide, i.e., formation of the excited state (UD/sub 2//sup 2 +/)* takes place during the reaction. It is proposed and experimentally verified that the reaction passes through an intermediate stage of formation of uranyl ion UO/sub 2//sup +/.

Comparison of the ability of organic acids and EDTA to enhance the phytoextraction of metals from a multi-metal contaminated soil.

Science.gov (United States)

Kim, Sung-Hyun; Lee, In-Sook

2010-02-01

Chelates have been shown to enhance the phytoextraction of metal from contaminated soil. In this study, we evaluated the ability of chelates to enhance the phytoextraction of metals by barnyard grass (Echinochloa crus-galli) from soils contaminated with multiple metals. The results revealed that EDTA increased the ability of barnyard grass to take up Cd, Cu and Pb, but that it resulted in increased soil leaching. Conversely, citric acid induced the removal of Cd, Cu and Pb from soil without increasing the risk of leaching. Furthermore, E.crus-galli showed no signs of phytotoxicity in response to treatment with citric acid, whereas its shoot growth decreased in response to treatment with EDTA (p acid is a good agent for the enhancement of the phytoextraction of metals.

The US Advanced Liquid-Metal Reactor Program

International Nuclear Information System (INIS)

Brolin, E.C.

1992-01-01

Based on National Energy Strategy projections, utilities will be required to substantially increase electric generating capacity over the next 40 yr to meet economic growth requirements and replace retiring capacity. Although aggressive conservation measures can save up to 85 GW(electric), ∼195 GW(electric) of additional generating capcity will still be needed by 2010. Assuming startup of new plants around 2000, US Department of Energy (DOE) analyses show that nuclear power can contribute 195 GW(electric) of capacity by 2030, or ∼20% of total electric generation. The DOE is involved in a number of strategies designed to revitalize the nuclear power industry and enable it to meet this projected need for additional capacity. Among these is an integrated overall strategy for advanced reactor development and high-level waste management. A high priority in pursuit of this strategy is the Advanced Liquid-Metal Reactor (ALMR) Program

Fabrication and characterisation of ligand-functionalised ultrapure monodispersed metal nanoparticle nanoassemblies employing advanced gas deposition technique

Science.gov (United States)

Geremariam Welearegay, Tesfalem; Cindemir, Umut; Österlund, Lars; Ionescu, Radu

2018-02-01

Here, we report for the first time the fabrication of ligand-functionalised ultrapure monodispersed metal nanoparticles (Au, Cu, and Pt) from their pure metal precursors using the advanced gas deposition technique. The experimental conditions during nanoparticle formation were adjusted in order to obtain ultrafine isolated nanoparticles on different substrates. The morphology and surface analysis of the as-deposited metal nanoparticles were investigated using scanning electron microscopy, x-ray diffraction and Fourier transform infra-red spectroscopy, which demonstrated the formation of highly ordered pure crystalline nanoparticles with a relatively uniform size distribution of ∼10 nm (Au), ∼4 nm (Cu) and ∼3 nm (Pt), respectively. A broad range of organic ligands containing thiol or amine functional groups were attached to the nanoparticles to form continuous networks of nanoparticle-ligand nanoassemblies, which were characterised by scanning electron microscopy and x-ray photoelectron spectroscopy. The electrical resistance of the functional nanoassemblies deposited in the gap spacing of two microfabricated parallel Au electrodes patterned on silicon substrates ranged between tens of kΩ and tens of MΩ, which is suitable for use in many applications including (bio)chemical sensors, surface-enhanced Raman spectroscopy and molecular electronic rectifiers.

Passive safety and the advanced liquid metal reactors

International Nuclear Information System (INIS)

Hill, D.J.; Pedersen, D.R.; Marchaterre, J.F.

1988-01-01

Advanced Liquid Metal Reactors being developed today in the USA are designed to make maximum use of passive safety features. Much of the LMR safety work at Argonne National Laboratory is concerned with demonstrating, both theoretically and experimentally, the effectiveness of the passive safety features. The characteristics that contribute to passive safety are discussed, with particular emphasis on decay heat removal systems, together with examples of Argonne's theoretical and experimental programs in this area

Recent advances of capillary electrophoresis in pharmaceutical analysis.

Science.gov (United States)

Suntornsuk, Leena

2010-09-01

This review covers recent advances of capillary electrophoresis (CE) in pharmaceutical analysis. The principle, instrumentation, and conventional modes of CE are briefly discussed. Advances in the different CE techniques (non-aqueous CE, microemulsion electrokinetic chromatography, capillary isotachophoresis, capillary electrochromatography, and immunoaffinity CE), detection techniques (mass spectrometry, light-emitting diode, fluorescence, chemiluminescence, and contactless conductivity), on-line sample pretreatment (flow injection) and chiral separation are described. Applications of CE to assay of active pharmaceutical ingredients (APIs), drug impurity testing, chiral drug separation, and determination of APIs in biological fluids published from 2008 to 2009 are tabulated.

Biotechnology for the extractive metals industries

Science.gov (United States)

Brierley, James A.

1990-01-01

Biotechnology is an alternative process for the extraction of metals, the beneficiation of ores, and the recovery of metals from aqueous systems. Currently, microbial-based processes are used for leaching copper and uranium, enhancing the recovery of gold from refractory ores, and treating industrial wastewater to recover metal values. Future developments, emanating from fundamental and applied research and advances through genetic engineering, are expected to increase the use and efficiency of these biotechnological processes.

JTEL Winter School for Advanced Technologically Enhanced Learning

NARCIS (Netherlands)

Glahn, Christian; Gruber, Marion

2010-01-01

Glahn, C., & Gruber, M. (2010). JTEL Winter School for Advanced Technologically Enhanced Learning. In ~mail. Das Magazin des Tiroler Bildungsinstituts, 01/10, März (p. 3-4). Innsbruck: Grillhof, Medienzentrum.

High Density Periodic Metal Nanopyramids for Surface Enhanced Raman Spectroscopy

NARCIS (Netherlands)

Jin, Mingliang

2012-01-01

The work presented in this thesis is focused on two areas. First, a new type of nanotextured noble-metal surface has been developed. The new nanotextured surface is demonstrated to enhance inelastic (Raman) scattering, called surface enhanced Raman scattering (SERS), from molecules adsorbed on the

Chemiluminescence evidence supporting the selective role of ligands in the permanganate oxidation of micropollutants.

Science.gov (United States)

Roderick, Mark S; Adcock, Jacqui L; Terry, Jessica M; Smith, Zoe M; Parry, Samuel; Linton, Stuart M; Thornton, Megan T; Barrow, Colin J; Francis, Paul S

2013-10-10

The selective increase in the oxidation rate of certain organic compounds with permanganate in the presence of environmental "ligands" and reduced species has been ascribed to the different reactivity of the target compounds toward Mn(III), which bears striking similarities to recent independent investigations into the use of permanganate as a chemiluminescence reagent. In spite of the importance of Mn(III) in the light-producing pathway, the dependence of the oxidation mechanism for any given compound on this intermediate could not be determined solely through the emission intensity. However, target compounds susceptible to single-electron oxidation by Mn(III) (such as bisphenol A and triclosan) can be easily distinguished by the dramatic increase in chemiluminescence intensity when a permanganate reagent containing high, stable concentrations of Mn(III) is used. The differences are accentuated under the low pH conditions that favor the chemiluminescence emission due to the greater reactivity of Mn(III) and the greater influence of complexing agents. This study supports the previously postulated selective role of ligands and reducing agents in permanganate oxidations and demonstrates a new approach to explore the chemistry of environmental manganese redox processes.

Bare and protected sputtered-noble-metal films for surface-enhanced Raman spectroscopy

Science.gov (United States)

Talaga, David; Bonhommeau, Sébastien

2014-11-01

Sputtered silver and gold films with different surface morphologies have been prepared and coated with a benzenethiol self-assembled monolayer. Rough noble metal films showed strong Raman features assigned to adsorbed benzenethiol molecules upon irradiation over a wide energy range in the visible spectrum, which disclosed the occurrence of a significant surface-enhanced Raman scattering with maximal enhancement factors as high as 6 × 106. In addition, the adsorption of ethanethiol onto silver surfaces hinders their corrosion over days while preserving mostly intact enhancement properties of naked silver. This study may be applied to develop stable and efficient metalized probes for tip-enhanced Raman spectroscopy.

A fluorescent and chemiluminescent difunctional mesoporous silica nanoparticle as a label for the ultrasensitive detection of cancer cells

Energy Technology Data Exchange (ETDEWEB)

Tao Liang [Key Laboratory of Analytical Chemistry for Life Science of Shaanxi Province, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi' an 710062 (China); Song Chaojun; Sun Yuanjie [Department of Immunology, The Fourth Military Medical University, Xi' an 710032 (China); Li Xiaohua; Li Yunyun [Key Laboratory of Analytical Chemistry for Life Science of Shaanxi Province, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi' an 710062 (China); Jin Boquan [Department of Immunology, The Fourth Military Medical University, Xi' an 710032 (China); Zhang Zhujun, E-mail: zhangzj@snnu.edu.cn [Key Laboratory of Analytical Chemistry for Life Science of Shaanxi Province, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi' an 710062 (China); Yang Kun, E-mail: yangkunkun@fmmu.edu.cn [Department of Immunology, The Fourth Military Medical University, Xi' an 710032 (China)

2013-01-25

Highlights: Black-Right-Pointing-Pointer Difunctional amino mesoporous silica nanoparticles (FCMSN) were synthesized. Black-Right-Pointing-Pointer The fluorescence and chemiluminescence properties of the FCMSN were studied. Black-Right-Pointing-Pointer The NaIO{sub 4} oxidation method was used for modification of the FCMSN. Black-Right-Pointing-Pointer Liver cancer 7721 cell was detected. Black-Right-Pointing-Pointer The specificity affected by FCMSN's amino groups was studied. - Abstract: A new kind of ultrabright fluorescent and chemiluminescent difunctional mesoporous silica nanoparticle (FCMSN) is reported. A luminescent dye, Rhodamine 6G or tris(2,2 Prime -bipyridyl)dichlororuthenium(II) hexahydrate (Rubpy), is doped inside nanochannels of a silica matrix. The hydrophobic groups in the silica matrix avoid the leakage of dye from open channels. The amines groups on the surface of the FCMSN improve the modification performance of the nanoparticle. Because the nanochannels are isolated by a network skeleton of silica, fluorescence quenching based on the inner filter effect of the fluorescent dyes immobilized in nanochannels is weakened effectively. The Quantum Yield of obtained 90 nm silica particles was about 61%. Compared with the fluorescent core-shell nanoparticle, the chemiluminescence reagents can freely enter the nanoparticles to react with fluorescent dyes to create chemiluminescence. The results show that the FCMSN are both fluorescent labels and chemiluminescent labels. In biological applications, the NaIO{sub 4} oxidation method was proven to be superior to the glutaraldehyde method. The amount of amino could affect the specificity of the FCMSN. The fluorescence microscopy imaging demonstrated that the FCMSN is viable for biological applications.

Chemiluminescence enzyme immunoassay based on magnetic nanoparticles for detection of hepatocellular carcinoma marker glypican-3

Directory of Open Access Journals (Sweden)

Qian-Yun Zhang

2011-08-01

Full Text Available Glypican-3 (GPC3 is reported as a great promising tumor marker for hepatocellular carcinoma (HCC diagnosis. Highly sensitive and accurate analysis of serum GPC3 (sGPC3, in combination with or instead of traditional HCC marker alpha-fetoprotein (AFP, is essential for early diagnosis of HCC. Biomaterial-functionalized magnetic particles have been utilized as solid supports with good biological compatibility for sensitive immunoassay. Here, the magnetic nanoparticles (MnPs and magnetic microparticles (MmPs with carboxyl groups were further modified with streptavidin, and applied for the development of chemiluminescence enzyme immunoassay (CLEIA. After comparing between MnPs- and MmPs-based CLEIA, MnPs-based CLEIA was proved to be a better method with less assay time, greater sensitivity, better linearity and longer chemiluminescence platform. MnPs-based CLEIA was applied for detection of sGPC3 in normal liver, hepatocirrhosis, secondary liver cancer and HCC serum samples. The results indicated that sGPC3 was effective in diagnosis of HCC with high performance. Keywords: Magnetic nanoparticle, Magnetic microparticle, Chemiluminescence enzyme immunoassay, Glypican-3, Hepatocellular carcinoma

Low temperature wetting and cleanup of alkali metal-advanced electrical machine systems

International Nuclear Information System (INIS)

Gass, W.R.; Witkowski, R.E.; Burrow, G.C.

1980-01-01

Advanced homopolar electrical machines employing high electrical current density, liquid metal sliprings for current transfer utilize NaK/sub 78/ (78 w/o potassium, 22 w/o sodium) for the conducting fluid. Experiments have been performed to improve alkali metal/oxide clean-up procedures. Studies have also confirmed chemical and materials compatibility between barium doped NaK/sub 78/ and typical machine structural materials. 4 refs

Advances in Metallic Fuels for High Burnup and Actinide Transmutation

Energy Technology Data Exchange (ETDEWEB)

Hayes, S. L.; Harp, J. M.; Chichester, H. J. M.; Fielding, R. S.; Mariani, R. D.; Carmack, W. J.

2016-10-01

Research and development activities on metallic fuels in the US are focused on their potential use for actinide transmutation in future sodium fast reactors. As part of this application, there is a desire to demonstrate a multifold increase in burnup potential. A number of metallic fuel design innovations are under investigation with a view toward significantly increasing the burnup potential of metallic fuels, since higher discharge burnups equate to lower potential actinide losses during recycle. Promising innovations under investigation include: 1) lowering the fuel smeared density in order to accommodate the additional swelling expected as burnups increase, 2) utilizing an annular fuel geometry for better geometrical stability at low smeared densities, as well as the potential to eliminate the need for a sodium bond, and 3) minor alloy additions to immobilize lanthanide fission products inside the metallic fuel matrix and prevent their transport to the cladding resulting in fuel-cladding chemical interaction. This paper presents results from these efforts to advance metallic fuel technology in support of high burnup and actinide transmutation objectives. Highlights include examples of fabrication of low smeared density annular metallic fuels, experiments to identify alloy additions effective in immobilizing lanthanide fission products, and early postirradiation examinations of annular metallic fuels having low smeared densities and palladium additions for fission product immobilization.

Chemiluminescence immunoassay for chloramphenicol

International Nuclear Information System (INIS)

Lin Si; Xu Wenge; Liu Yibing

2007-06-01

A simple, solid-phase chemiluminescence immunoassay (CLIA) for the measurement of Chloramphenicol(CAP) in foodstuffs is described. A rabbit anti-CAP IgG is passively adsorbed onto the walls of polypropylene plates. The labeled conjugant is horseradish peroxidase(HRP) conjugate of CAP. Luminol solution is used as the substrate of HRP. The light yield is inversely proportional to the concentration of CAP. The method has a similar sensitivity (0.05 ng/mL), specificity, precision, and accuracy to a conventional enzyme immunoassay (EIA). The intra-assay and inter-assay CVs of ten samples were <8 and <20%, respectively, and the analytical recovery of the method was 87% 100%. The experimental correlation coefficient of dilution was found to be 0.999 using milk supernatant as buffer. The assay range for the method was 0.1-10 ng/mL, and it displayed good linearity. (authors)

Percolation-enhanced nonlinear scattering from semicontinuous metal films

Science.gov (United States)

Breit, M.; von Plessen, G.; Feldmann, J.; Podolskiy, V. A.; Sarychev, A. K.; Shalaev, V. M.; Gresillon, S.; Rivoal, J. C.; Gadenne, P.

2001-03-01

Strongly enhanced second-harmonic generation (SHG), which is characterized by nearly isotropic distribution, is observed for gold-glass films near the percolation threshold. The diffuse-like SHG scattering, which can be thought of as nonlinear critical opalescence, is in sharp contrast with highly collimated linear reflection and transmission from these nanostructured semicontinuous metal films. Our observations, which can be explained by giant fluctuations of local nonlinear sources for SHG, verify recent predictions of percolation-enhanced nonlinear scattering.

Advances in Understanding How Heavy Metal Pollution Triggers Gastric Cancer

Directory of Open Access Journals (Sweden)

Wenzhen Yuan

2016-01-01

Full Text Available With the development of industrialization and urbanization, heavy metals contamination has become a major environmental problem. Numerous investigations have revealed an association between heavy metal exposure and the incidence and mortality of gastric cancer. The mechanisms of heavy metals (lead, cadmium, mercury, chromium, and arsenic contamination leading to gastric cancer are concluded in this review. There are four main potential mechanisms: (1 Heavy metals disrupt the gastric mucosal barrier by decreasing mucosal thickness, mucus content, and basal acid output, thereby affecting the function of E-cadherin and inducing reactive oxygen species (ROS damage. (2 Heavy metals directly or indirectly induce ROS generation and cause gastric mucosal and DNA lesions, which subsequently alter gene regulation, signal transduction, and cell growth, ultimately leading to carcinogenesis. Exposure to heavy metals also enhances gastric cancer cell invasion and metastasis. (3 Heavy metals inhibit DNA damage repair or cause inefficient lesion repair. (4 Heavy metals may induce other gene abnormalities. In addition, heavy metals can induce the expression of proinflammatory chemokine interleukin-8 (IL-8 and microRNAs, which promotes tumorigenesis. The present review is an effort to underline the human health problem caused by heavy metal with recent development in order to garner a broader perspective.

Thermally generated metals for plasmonic coloring and surface-enhanced Raman sensing

Science.gov (United States)

Huang, Zhenping; Chen, Jian; Liu, Guiqiang; Wang, Yan; Liu, Yi; Tang, Li; Liu, Zhengqi

2018-03-01

Spectral coloring glass and its application on the surface-enhanced Raman scattering are demonstrated experimentally via a simple and moderate heat-treating of the top ultrathin gold film to create discrete nanoparticles, which can produce localized surface plasmon resonances and strong plasmonic near-field coupling effects. Ultrathin metal films with a wide range of thicknesses are investigated by different heat-treatment processes. The annealed metal films have been demonstrated with a series of spectral coloring responses. Moreover, the microscopy images of the metal film structures confirm the formation of distinct geometry features in these operation procedures. Densely packed nanoparticles are observed for the ultrathin metal film with the single-digit level of thickness. With increasing the film thickness over 10 nm, metallic clusters and porous morphologies can be obtained. Importantly, the metallic resonators can provide enhanced Raman scattering with the detection limit down to 10 - 7 molL - 1 of Rhodamine 6G molecules due to the excitation of plasmon resonances and strong near-field coupling effects. These features hold great potential for large-scale and low-cost production of colored glass and Raman substrate.

Chemiluminescence measurements as an identification method for gamma-irradiated foodstuffs

Energy Technology Data Exchange (ETDEWEB)

Boegl, W; Heide, L

1985-01-01

Samples of 19 different spices, milk powder, whole onions and frozen chicken were exposed to a Co-60 source with radiation doses up to 10/sup 4/ Gy. The subsequent reaction of the irradiated foodstuffs in a luminol solution resulted in light emission (chemiluminescence). This effect can be used as an indicator of radiation treatment.

Recent advances in nanoscale-metal assisted biochar derived from waste biomass used for heavy metals removal.

Science.gov (United States)

Ho, Shih-Hsin; Zhu, Shishu; Chang, Jo-Shu

2017-12-01

Pollution of heavy metals (HMs) is a detrimental treat to human health and need to be cleaned up in a proper way. Biochar (BC), a low-cost and "green" adsorbent, has attracted significant attention due to its considerable HMs removal capacity. In particular, nano-metals have recently been used to assist BC in improving its reactivity, surface texture and magnetism. Synthesis methods and metal precursors greatly influence the properties and structures of the nanocomposites, thereby affecting their HMs removal performance. This review presents advances in synthesis methods, formation mechanisms and surface characteristics of BC nanocomposites, along with the discussions on HMs removal mechanisms and the effects of environmental factors on HMs removal efficiency. Performance of using BC nanocomposites to remediate real HMs-containing wastewater and issues associated with its process scale-up are also discussed. This review aims to provide useful information to facilitate the development of HMs removal by nanoscale-metal assisted BC. Copyright © 2017 Elsevier Ltd. All rights reserved.

Safety characteristics of the US advanced liquid metal reactor core

International Nuclear Information System (INIS)

Magee, P.M.; Dubberley, A.E.; Gyorey, G.L.; Lipps, A.J.; Wu, T.

1991-01-01

The U.S. Advanced Liquid Metal Reactor (ALMR) design employs innovative, passive features to provide an unprecedented level of public safety and the ability to demonstrate this safety to the public. The key features employed in the core design to produce the desired passive safety characteristics are: a small core with a tight restraint system, the use of metallic U-Pu-Zr fuel, control rod withdrawal limiters, and gas expansion modules. In addition, the reactor vessel and closure are designed to have the capability to withstand, with large margins, the maximum possible core disruptive accident without breach and radiological release. (author)

Tomographic reconstruction of OH* chemiluminescence in two interacting turbulent flames

International Nuclear Information System (INIS)

Worth, Nicholas A; Dawson, James R

2013-01-01

The tomographic reconstruction of OH* chemiluminescence was performed on two interacting turbulent premixed bluff-body stabilized flames under steady flow conditions and acoustic excitation. These measurements elucidate the complex three-dimensional (3D) vortex–flame interactions which have previously not been accessible. The experiment was performed using a single camera and intensifier, with multiple views acquired by repositioning the camera, permitting calculation of the mean and phase-averaged volumetric OH* distributions. The reconstructed flame structure and phase-averaged dynamics are compared with OH planar laser-induced fluorescence and flame surface density measurements for the first time. The volumetric data revealed that the large-scale vortex–flame structures formed along the shear layers of each flame collide when the two flames meet, resulting in complex 3D flame structures in between the two flames. With a fairly simple experimental setup, it is shown that the tomographic reconstruction of OH* chemiluminescence in forced flames is a powerful tool that can yield important physical insights into large-scale 3D flame dynamics that are important in combustion instability. (paper)

Studies in the reaction dynamics of beam-gas chemiluminescent reactions

International Nuclear Information System (INIS)

Prisant, M.G.

1984-01-01

This thesis develops techniques for the analysis and interpretation of data obtained from beam-gas chemiluminescence experiments. These techniques are applied to experimental studies of atom transfer reactions of the type A + BC → AB + C. A procedure is developed for determining the product rotational alignment in the center-of-mass frame from polarization measurements of chemiluminescent atom-diatom exchange reactions under beam-gas conditions. Knowledge of a vector property of a reaction, such as product alignment, provides information on the disposition of angular momentum by a chemical reaction. Fluorescence polarization and hence product alignment are measured for two prototype reactions. The reaction of metastable calcium atoms with hydrogen-chloride gas yields highly aligned calcium-chloride product which exhibits little variation of alignment with vibrational state. The reaction of ground-state calcium with fluorine gas yields moderately aligned product which shows strong variation of alignment with vibration. A multi-surface direct-interaction model is developed to interpret product alignment and population data. The predictions of this model for the reaction of calcium with fluorine show reasonable agreement with experiment

Chemiluminescence of curcumin and quenching effect of dimethyl sulfoxide on its peroxyoxalate system

Energy Technology Data Exchange (ETDEWEB)

Yari, Abdollah, E-mail: a.yari@ymail.co [Lorestan University, Department of Chemistry, Flakalaflak Street, 68178-17133 Khorramabad (Iran, Islamic Republic of); Saidikhah, Marzieh [Lorestan University, Department of Chemistry, Flakalaflak Street, 68178-17133 Khorramabad (Iran, Islamic Republic of)

2010-04-15

The chemiluminescence behavior of the reaction between bis(2,4,6-trichlorophenyl)oxalate (TCPO) and hydrogen peroxide, in the presence of curcumin as fluorophore, has been investigated. Experimental factors such as TCPO, sodium salicylate (SS), hydrogen peroxide and curcumin concentration were optimized. The chemiluminescence signal showed a linear decay while dimethyl sulfoxide (DMSO) was added to the peroxyoxalate (PO-CL) system. The reaction resulted in a Stern-Volmer plot with a K{sub q} value of 7.3x10{sup 4}. The evaluated lower and upper detection limits of measurable concentrations of DMSO are 3.50x10{sup -5} and 1.53x10{sup -4} M, respectively. The PO-CL parameters were estimated by computer fitting of the experimental CL intensity to proper models.

Metal fire implications for advanced reactors. Part 1, literature review

International Nuclear Information System (INIS)

Nowlen, Steven Patrick; Radel, Ross F.; Hewson, John C.; Olivier, Tara Jean; Blanchat, Thomas K.

2007-01-01

Public safety and acceptance is extremely important for the nuclear power renaissance to get started. The Advanced Burner Reactor and other potential designs utilize liquid sodium as a primary coolant which provides distinct challenges to the nuclear power industry. Fire is a dominant contributor to total nuclear plant risk events for current generation nuclear power plants. Utilizing past experience to develop suitable safety systems and procedures will minimize the chance of sodium leaks and the associated consequences in the next generation. An advanced understanding of metal fire behavior in regards to the new designs will benefit both science and industry. This report presents an extensive literature review that captures past experiences, new advanced reactor designs, and the current state-of-knowledge related to liquid sodium combustion behavior

A turn-on chemiluminescence biosensor for selective and sensitive detection of adenosine based on HKUST-1 and QDs-luminol-aptamer conjugates.

Science.gov (United States)

Lin, Yanna; Dai, Yuxue; Sun, Yuanling; Ding, Chaofan; Sun, Weiyan; Zhu, Xiaodong; Liu, Hao; Luo, Chuannan

2018-05-15

In this work, HKUST-1 and QDs-luminol-aptamer conjugates were prepared. The QDs-luminol-aptamer conjugates can be adsorbed by graphene oxide through π-π conjugation. When the adenosine was added, the QDs-luminol-aptamer conjugates were released from magnetic graphene oxide (MGO), the chemiluminescent switch was turned on. It was reported that HKUST-1 can catalyze the chemiluminescence reaction of luminol-H 2 O 2 system in an alkaline medium, and improve the chemiluminescence resonance energy transfer (CRET) between chemiluminescence and QDs indirectly. Thus, the adenosine can be detected sensitively. Based on this phenomenon, the excellent platform for detection of adenosine was established. Under the optimized conditions, the linear detection range for adenosine was 1.0 × 10 -12 -2.2 × 10 -10 mol/L with a detection limit of 2.1 × 10 -13 mol/L. The proposed method was successfully used for adenosine detection in biological samples. Copyright © 2018 Elsevier B.V. All rights reserved.

Significance of isolated reactive treponemal chemiluminescence immunoassay results.

Science.gov (United States)

Hunter, Michael G; Robertson, Peter W; Post, Jeffrey J

2013-05-01

Isolated reactive serum treponemal chemiluminescence immunoassay (CIA) specimens cause clinical uncertainty. Sera were screened by CIA, and reactive samples underwent reflex testing with rapid plasma reagin (RPR), Treponema pallidum particle agglutination (TPPA), and fluorescent treponemal antibody absorption (FTA Abs) assays. Samples reactive only on the CIA were deemed "isolated" reactive CIA samples. We undertook detailed review of a subset of subjects with isolated reactive CIA specimens. Of 28 261 specimens, 1171 (4.1%) were reactive on CIA, of which 133 (11.3%) had isolated CIA reactivity. Most subjects (66 of 82 [80.5%]) with isolated reactive CIA specimens were from high-prevalence populations. We found evidence of CIA, TPPA, and FTA Abs seroreversion. The median chemiluminescent signal-to-cutoff ratio was similar for isolated reactive CIA sera and sera that were reactive on either FTA Abs or TPPA assays (2.19 vs 2.32; P = .15) but lower than for sera reactive on both FTA Abs and TPPA assays (12.37; P < .001) or for sera reactive on RPR assays (25.53; P < .001). A total of 11 of 20 patients (55%) with an isolated reactive CIA specimen who underwent medical record review had previous or subsequent evidence of syphilis infection. Isolated reactive CIA specimens may represent true T. pallidum infection and may be found after seroreversion of traditional treponemal assays.

Metal hydride hydrogen compression: recent advances and future prospects

Science.gov (United States)

Yartys, Volodymyr A.; Lototskyy, Mykhaylo; Linkov, Vladimir; Grant, David; Stuart, Alastair; Eriksen, Jon; Denys, Roman; Bowman, Robert C.

2016-04-01

Metal hydride (MH) thermal sorption compression is one of the more important applications of the MHs. The present paper reviews recent advances in the field based on the analysis of the fundamental principles of this technology. The performances when boosting hydrogen pressure, along with two- and three-step compression units, are analyzed. The paper includes also a theoretical modelling of a two-stage compressor aimed at describing the performance of the experimentally studied systems, their optimization and design of more advanced MH compressors. Business developments in the field are reviewed for the Norwegian company HYSTORSYS AS and the South African Institute for Advanced Materials Chemistry. Finally, future prospects are outlined presenting the role of the MH compression in the overall development of the hydrogen-driven energy systems. The work is based on the analysis of the development of the technology in Europe, USA and South Africa.

Recent advances in functional assays of transcriptional enhancers.

Science.gov (United States)

Babbitt, Courtney C; Markstein, Michele; Gray, Jesse M

2015-09-01

In this special edition of Genomics, we present reviews of the current state of the field in identifying and functionally understanding transcriptional enhancers in cells and developing tissues. Typically several enhancers coordinate the expression of an individual target gene, each controlling that gene's expression in specific cell types at specific times. Until recently, identifying each gene's enhancers had been challenging because enhancers do not occupy prescribed locations relative to their target genes. Recently there have been powerful advances in DNA sequencing and other technologies that make it possible to identify the majority of enhancers in virtually any cell type of interest. The reviews in this edition of Genomics highlight some of these new and powerful approaches. Copyright © 2015 Elsevier Inc. All rights reserved.

Carbon-enhanced metal-poor stars in dwarf galaxies

NARCIS (Netherlands)

Salvadori, Stefania; Skúladóttir, Ása; Tolstoy, Eline

2015-01-01

We investigate the frequency and origin of carbon-enhanced metal-poor (CEMP) stars in Local Group dwarf galaxies by means of a statistical, data-calibrated cosmological model for the hierarchical build-up of the Milky Way and its dwarf satellites. The model self-consistently explains the variation

A novel chemiluminescence assay of organophosphorous pesticide quinalphos residue in vegetable with luminol detection

Directory of Open Access Journals (Sweden)

Yao Xin

2010-06-01

Full Text Available Abstract Background Organophosphorous pesticides are the most popular pesticides used in agriculture. As acetylcholinesterase inhibitors, organophosphorous pesticides are toxic organic chemicals. The control and detection of organophosphorous pesticide residue in food, water, and environment therefore plays a very important role in maintaining physical health. A sensitive, rapid, simple chemiluminescence(CL method has been developed for the determination of quinalphos based on the reaction of quinalphos with luminol-H2O2 in an alkaline medium. The method has been applied to detection of quinalphos in vegetable samples with satisfactory results. Results The CL method for the determination of organophosphorous pesticide quinalphos is based on the phenomenon that quinalphos can apparently enhance the CL intensity of the luminol-H2O2 system. The optimal conditions were: luminol concentration 5.0 × 10-4 mol/L, H2O2 concentration 0.05 mol/L.pH value 13. In order to restrain the interference from metal ions, 1.0 × 10-3 mol/L of EDTA was added to the luminol solution. The possible mechanism was proposed. Conclusion Under the optimum reaction conditions, CL was linear with the concentration of quinalphos in the range of 0.02 μg/mL -1.0 μg/mL and the detection limit was 0.0055 μg/mL (3σ. This method has been successfully applied to the detection of quinalphos in vegetable samples. According to the experimental data, the average recoveries for quinalphos in cherry tomato and green pepper 97.20% and 90.13%. Meanwhile, the possible mechanism was proposed.

Differentiating between intra- and extracellular chemiluminescence in diluted whole-blood samples

Czech Academy of Sciences Publication Activity Database

Rájecký, Michal; Lojek, Antonín; Číž, Milan

2012-01-01

Roč. 34, č. 2 (2012), s. 136-142 ISSN 1751-5521 R&D Projects: GA MŠk(CZ) OC10044 Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50040702 Keywords : chemiluminescence * isoluminol * whole blood Subject RIV: BO - Biophysics Impact factor: 1.293, year: 2012

Enhanced and tunable electric dipole-dipole interactions near a planar metal film

Science.gov (United States)

Zhou, Lei-Ming; Yao, Pei-Jun; Zhao, Nan; Sun, Fang-Wen

2017-08-01

We investigate the enhanced electric dipole-dipole interaction of surface plasmon polaritons (SPPs) supported by a planar metal film waveguide. By taking two nitrogen-vacancy (NV) center electric dipoles in diamond as an example, both the coupling strength and collective relaxation of two dipoles are studied with the numerical Green Function method. Compared to two-dipole coupling on a planar surface, metal film provides stronger and tunable coupling coefficients. Enhancement of the interaction between coupled NV center dipoles could have applications in both quantum information and energy transfer investigation. Our investigation provides systematic results for experimental applications based on a dipole-dipole interaction mediated with SPPs on a planar metal film.

Metal-chelating active packaging film enhances lysozyme inhibition of Listeria monocytogenes.

Science.gov (United States)

Roman, Maxine J; Decker, Eric A; Goddard, Julie M

2014-07-01

Several studies have demonstrated that metal chelators enhance the antimicrobial activity of lysozyme. This study examined the effect of metal-chelating active packaging film on the antimicrobial activity of lysozyme against Listeria monocytogenes. Polypropylene films were surface modified by photoinitiated graft polymerization of acrylic acid (PP-g-PAA) from the food contact surface of the films to impart chelating activity based on electrostatic interactions. PP-g-PAA exhibited a carboxylic acid density of 113 ± 5.4 nmol cm(-2) and an iron chelating activity of 53.7 ± 9.8 nmol cm(-2). The antimicrobial interaction of lysozyme and PP-g-PAA depended on growth media composition. PP-g-PAA hindered lysozyme activity at low ionic strength (2.48-log increase at 64.4 mM total ionic strength) and enhanced lysozyme activity at moderate ionic strength (5.22-log reduction at 120 mM total ionic strength). These data support the hypothesis that at neutral pH, synergy between carboxylate metal-chelating films (pKa(bulk) 6.45) and lysozyme (pI 11.35) is optimal in solutions of moderate to high ionic strength to minimize undesirable charge interactions, such as lysozyme absorption onto film. These findings suggest that active packaging, which chelates metal ions based on ligand-specific interactions, in contrast to electrostatic interactions, may improve antimicrobial synergy. This work demonstrates the potential application of metal-chelating active packaging films to enhance the antimicrobial activity of membrane-disrupting antimicrobials, such as lysozyme.

Phenylboronic acid immunoaffinity reactor coupled with flow injection chemiluminescence for determination of {alpha}-fetoprotein

Energy Technology Data Exchange (ETDEWEB)

Wu Yafeng [Jiangsu Provincial Key Lab of Biomaterials and Biodevices, School of Chemistry and Chemical Engineering, Southeast University, Nanjing 210096 (China); Zhuang Yafeng [Department of Chemistry, Changzhou Institute of Technology, Changzhou 213022 (China); Liu Songqin [Jiangsu Provincial Key Lab of Biomaterials and Biodevices, School of Chemistry and Chemical Engineering, Southeast University, Nanjing 210096 (China)], E-mail: liusq@seu.edu.cn; He Lin [Department of Chemistry, North Carolina State University, Raleigh, NC 27695-8204 (United States)

2008-12-23

A reusable and sensitive immunoassay based on phenylboronic acid immunoaffinity reactor in combination with flow injection chemiluminescence (CL) for determination of glycoprotein was described. The reactor was fabricated by immobilizing 3-aminophenylboronic acid (APBA) on glass microbeads with {gamma}-glycidoxypropyltrimethoxysilane (GPMS) as linkage. The {alpha}-fetoprotein (AFP) could be easily immobilized on the APBA coated beads through sugar-boronic interaction. After an off-line incubation, the mixture of the analyte AFP with horseradish peroxidase-labeled AFP antibody (HRP-anti-AFP) was injected into the reactor. This led the trapping of free HRP-anti-AFP by the surface coated AFP on glass beads. The trapped HRP-anti-AFP was detected by chemiluminescence due to its sensitizing effect on the reaction of luminol and hydrogen peroxide. Under optimal conditions, the chemiluminescent signal was proportional to AFP concentration in the range of 10-100 ng mL{sup -1}. The whole assay process including regeneration of the reactor could be completed within 31 min. The proposed system showed acceptable detection and fabrication reproducibility, and the results obtained with the present method were in acceptable agreement with those from parallel single-analyte test of practical clinical sera. The described method enabled a low-cost, time saving and was potential to detect the serum AFP level in clinical diagnosis.

Off-line phase-averaged particle image velocimetry and OH chemiluminescence measurements using acoustic time series

International Nuclear Information System (INIS)

Fischer, A; Bake, F; Heinze, J; Willert, C; Diers, O; Röhle, I

2009-01-01

In order to analyze unsteady flow phenomena in combustion facilities two phase-sorting methods have been developed and investigated for the retrieval of phase-resolved data from (randomly) sampled 'single-shot' data such as PIV recordings or chemiluminescence imagery in a post-processing step. This is made possible by simultaneously recorded continuous time traces of reference data (e.g., pressure signal). Using this off-line method synchronous phase-locked PIV and OH chemiluminescence visualizations could be recovered from data obtained in two different combustion facilities. This paper also presents some of the theoretical background necessary for the application of two different phase-sorting algorithms

Enhanced electrogenerated chemiluminescence of Ru(bpy){sub 3}{sup 2+}/TPrA (bpy=2,2'-bipyridine; TPrA=tri-n-propylamine) via oxygen quenching using melatonin

Energy Technology Data Exchange (ETDEWEB)

Witt, Maria D.; Roughton, Sarah; Isakson, Timothy J.; Richter, Mark M., E-mail: markrichter@missouristate.edu

2016-03-15

The effect on the electrogenerated chemiluminescence (ECL) of the Ru(bpy){sub 3}{sup 2+}/TPrA (bpy=2,2'-bipyridine; TPra=tri-n-propylamine) system when melatonin (N-acetyl-5-methoxytryptamine; MLT) and structurally related compounds (e.g., D- and L-Tryptophan (TRY), 7-Azatryptophan (7-AZA) and Serotonin (SER)) are present in aqueous buffered solution is reported. MLT, D- and L-TRY, SER and 7-AZA display weak intrinsic ECL when TPrA is used as an oxidative–reductive coreactant. However, micromolar concentrations of melatonin result in up to 2.5-fold enhancement of Ru(bpy){sub 3}{sup 2+}/TPrA ECL while the other analytes attenuate ECL between 2- and 1000-fold. Photoluminescence (PL) emission efficiencies do not change in the presence of melatonin unless the melatonin solution has undergone electrochemical bulk oxidation, at which point PL and ECL are nearly indistinguishable. Spectroscopic, electrochemical and spectroelectrochemical studies indicate that the mechanism involves oxygen scavenging by melatonin oxidation products. This scavenging prevents the quenching of the {sup *}Ru(bpy){sub 3}{sup 2+} excited states by dissolved oxygen in solution. Melatonin can be coupled with 30% by volume 2,2,2-trifluorethanol (TFE) or with the nonionic surfactant Triton X-100 (polyethylene glycol tert-octylphenyl ether) for even greater enhancement of Ru(bpy){sub 3}{sup 2+}/TPrA ECL.

ADVANCED TECHNOLOGIES FOR STRIPPER GAS WELL ENHANCEMENT

International Nuclear Information System (INIS)

Charles M. Boyer II; Ronald J. MacDonald P.G.

2001-01-01

As part of Task 1 in Advanced Technologies for Stripper Gas Well Enhancement, Schlumberger-Holditch Reservoir Technologies (H-RT) has joined with two Appalachian Basin producers, Great Lakes Energy Partners, LLC, and Belden and Blake Corporation to develop methodologies for identification and enhancement of stripper wells with economic upside potential. These industry partners have provided us with data for more than 700 wells in northwestern Pennsylvania. Phase 1 goals of this project are to develop and validate methodologies that can quickly and cost-effectively identify wells with enhancement potential. We have continued to enhance and streamline our software, and we are testing the final stages of our new Microsoft(trademark) Access/Excel based software. We are continuing to process this well data and are identifying potential candidate wells that can be used in Phase 2 to validate the new methodologies. In addition, preparation of the final technical report is underway

Carbon-enhanced metal-poor stars and thermohaline mixing

NARCIS (Netherlands)

Stancliffe, R.J.; Glebbeek, E.; Izzard, R.G.; Pols, O.R.

2007-01-01

One possible scenario for the formation of carbon-enhanced metal-poor stars is the accretion of carbon-rich material from a binary companion which may no longer visible. It is generally assumed that the accreted material remains on the surface of the star and does not mix with the interior until

The origin of enhanced optical absorption in solar cells with metal nanoparticles embedded in the active layer

KAUST Repository

Lee, Jung-Yong

2010-04-29

We analyze the enhancement in optical absorption of an absorbing medium when spherical metal nanoparticles are embedded in it. Our analysis uses generalized Mie theory to calculate the absorbed optical power as a function of the distance from the metal nanoparticle. This analysis is used to evaluate the potential of enhancing optical absorption in thin-film solar cells by embedding spherical metal nanoparticles. We consider the trade-off between maximizing overall optical absorption and ensuring that a large fraction of the incident optical power is dissipated in the absorbing host medium rather than in the metal nanoparticle. We show that enhanced optical absorption results from strong scattering by the metal nanoparticle which locally enhances the optical electric fields. We also discuss the effect of a thin dielectric encapsulation of the metal nanoparticles. ©2010 Optical Society of America.

The origin of enhanced optical absorption in solar cells with metal nanoparticles embedded in the active layer

KAUST Repository

Lee, Jung-Yong; Peumans, Peter

2010-01-01

We analyze the enhancement in optical absorption of an absorbing medium when spherical metal nanoparticles are embedded in it. Our analysis uses generalized Mie theory to calculate the absorbed optical power as a function of the distance from the metal nanoparticle. This analysis is used to evaluate the potential of enhancing optical absorption in thin-film solar cells by embedding spherical metal nanoparticles. We consider the trade-off between maximizing overall optical absorption and ensuring that a large fraction of the incident optical power is dissipated in the absorbing host medium rather than in the metal nanoparticle. We show that enhanced optical absorption results from strong scattering by the metal nanoparticle which locally enhances the optical electric fields. We also discuss the effect of a thin dielectric encapsulation of the metal nanoparticles. ©2010 Optical Society of America.

An Advanced Semimetal-Organic Bi Spheres-g-C3N4 Nanohybrid with SPR-Enhanced Visible-Light Photocatalytic Performance for NO Purification.

Science.gov (United States)

Dong, Fan; Zhao, Zaiwang; Sun, Yanjuan; Zhang, Yuxin; Yan, Shuai; Wu, Zhongbiao

2015-10-20

To achieve efficient photocatalytic air purification, we constructed an advanced semimetal-organic Bi spheres-g-C3N4 nanohybrid through the in-situ growth of Bi nanospheres on g-C3N4 nanosheets. This Bi-g-C3N4 compound exhibited an exceptionally high and stable visible-light photocatalytic performance for NO removal due to the surface plasmon resonance (SPR) endowed by Bi metal. The SPR property of Bi could conspicuously enhance the visible-light harvesting and the charge separation. The electromagnetic field distribution of Bi spheres involving SPR effect was simulated and reaches its maximum in close proximity to the Bi particle surface. When the Bi metal content was controlled at 25%, the corresponding Bi-g-C3N4 displayed outstanding photocatalytic capability and transcended those of other visible-light photocatalysts. The Bi-g-C3N4 exhibited a high structural stability under repeated photocatalytic runs. A new visible-light-induced SPR-based photocatalysis mechanism with Bi-g-C3N4 was proposed on the basis of the DMPO-ESR spin-trapping. The photoinduced electrons could transfer from g-C3N4 to the Bi metal, as revealed with time-resolved fluorescence spectra. The function of Bi semimetal as a plasmonic cocatalyst for boosting visible light photocatalysis was similar to that of noble metals, which demonstrated a great potential of utilizing the economically feasible Bi element as a substitute for noble metals for the advancement of photocatalysis efficiency.

Enhanced in-pile instrumentation at the advanced test reactor

Energy Technology Data Exchange (ETDEWEB)

Rempe, J. L.; Knudson, D. L.; Daw, J. E.; Unruh, T.; Chase, B. M.; Palmer, J.; Condie, K. G.; Davis, K. L. [Idaho National Laboratory, MS 3840, P.O. Box 1625, Idaho Falls, ID 83415 (United States)

2011-07-01

Many of the sensors deployed at materials and test reactors cannot withstand the high flux/high temperature test conditions often requested by users at U.S. test reactors, such as the Advanced Test Reactor (ATR) at the Idaho National Laboratory. To address this issue, an instrumentation development effort was initiated as part of the ATR National Scientific User Facility in 2007 to support the development and deployment of enhanced in-pile sensors. This paper reports results from this effort. Specifically, this paper identifies the types of sensors currently available to support in-pile irradiations and those sensors currently available to ATR users. Accomplishments from new sensor technology deployment efforts are highlighted by describing new temperature and thermal conductivity sensors now available to ATR users. Efforts to deploy enhanced in-pile sensors for detecting elongation and realtime flux detectors are also reported, and recently-initiated research to evaluate the viability of advanced technologies to provide enhanced accuracy for measuring key parameters during irradiation testing are noted. (authors)

Enhanced In-Pile Instrumentation at the Advanced Test Reactor

Science.gov (United States)

Rempe, Joy L.; Knudson, Darrell L.; Daw, Joshua E.; Unruh, Troy; Chase, Benjamin M.; Palmer, Joe; Condie, Keith G.; Davis, Kurt L.

2012-08-01

Many of the sensors deployed at materials and test reactors cannot withstand the high flux/high temperature test conditions often requested by users at U.S. test reactors, such as the Advanced Test Reactor (ATR) at the Idaho National Laboratory. To address this issue, an instrumentation development effort was initiated as part of the ATR National Scientific User Facility in 2007 to support the development and deployment of enhanced in-pile sensors. This paper provides an update on this effort. Specifically, this paper identifies the types of sensors currently available to support in-pile irradiations and those sensors currently available to ATR users. Accomplishments from new sensor technology deployment efforts are highlighted by describing new temperature and thermal conductivity sensors now available to ATR users. Efforts to deploy enhanced in-pile sensors for detecting elongation and real-time flux detectors are also reported, and recently-initiated research to evaluate the viability of advanced technologies to provide enhanced accuracy for measuring key parameters during irradiation testing are noted.

Negative interference by rheumatoid factor in alpha-fetoprotein chemiluminescent microparticle immunoassay.

Science.gov (United States)

Wang, Hui; Bi, Xiaohui; Xu, Lei; Li, Yirong

2017-01-01

Background Rheumatoid factor causes positive interference in multiple immunoassays. Recently, negative interference has also been found in immunoassays in the presence of rheumatoid factor. The chemiluminescent microparticle immunoassay is widely used to determine serum alpha-fetoprotein. However, it is not clear whether the presence of rheumatoid factor in the serum causes interference in the chemiluminescent microparticle immunoassay of alpha-fetoprotein. Methods Serum alpha-fetoprotein was determined using the ARCHITECT alpha-fetoprotein assay. The estimation of alpha-fetoprotein recovery was carried out in samples prepared by diluting high-concentration alpha-fetoprotein serum with rheumatoid factor-positive or rheumatoid factor-negative serum. Paramagnetic microparticles coated with hepatitis B surface antigen-anti-HBs complexes were used to remove rheumatoid factor from the serum. Results The average recovery of alpha-fetoprotein was 88.4% and 93.8% in the rheumatoid factor-positive and rheumatoid factor-negative serum samples, respectively. The recovery of alpha-fetoprotein was significantly lower in the rheumatoid factor-positive serum samples than in the rheumatoid factor-negative serum samples. In two of five rheumatoid factor-positive samples, a large difference was found (9.8%) between the average alpha-fetoprotein recoveries in the serially diluted and initial recoveries. Fourteen rheumatoid factor-positive serum samples were pretreated with hepatitis B surface antigen-anti-HBs complex-coated paramagnetic microparticles. The alpha-fetoprotein concentrations measured in the pretreated samples increased significantly. Conclusions It was concluded that the alpha-fetoprotein chemiluminescent microparticle immunoassay is susceptible to interference by rheumatoid factor, leading to significantly lower results. Eliminating the incidence of negative interference from rheumatoid factor should be an important goal for immunoassay providers. In the meantime

The chemiluminescence of luminol in aqueous solutions, a pulse radiolytic study

International Nuclear Information System (INIS)

Lind, J.

1980-01-01

The mechanism of chemiluminescence was studied when the luminol radical and superoxide were generated simultaneously. Hydroperoxide was formed at the first reaction step with a pKa value between 11 and 12. The dissociated form was found to undergo a monomolecular reaction leading to light generation and having a rate constant > 2 x 10 5 s -1 . The protonated form had the rate constant of approx. 2000 s -1 and formed a product which absorbed around 390 nm without light emission. The reaction of the two-electron oxidation product of luminol, 5-aminophthalazine-1, 4 dione (azaquinone), with hydrogenperoxide was stoichiometrically equivalent to the recombination of superoxide with the luminol radical. The pulseradiolytic generation of the chlorinedioxide radical ClO 2 in aqueous solution of sodium chlorite is described, and the oxidation of luminol by ClO 2 in two steps is reported: 1. Radical adducts are formed. 2. The reaction of ClO 2 x radical with the adduct to form azaquinone. The chemiluminescent reaction between the azaquinone and hydrogenperoxide consists of a second order reaction between HO 2 and the azaquinone to form a hydroperoxide followed by a monomolecular rearrangement of the dissociated form of the latter. Its acidbase equilibrium has a pKa of 10.6. A nitrogencentered structure is ascribed to the hydroperoxide formed by cross-recombination of the luminolradical and superoxide while the reaction between HO 2 and azaquinone yields a carboncentered hydroperoxide. The existence of two different emitters is evidenced by the following observations. 1. A slight difference in chemiluminescence spectra. 2. The formation of an endproduct with pKa approx. 10.2 in the luminolradical superoxide system. 3. The formation of an endproduct which acts as an efficient radial scavenger in the luminol radical superoxide system. (G.B.)

Chemiluminescence from the reaction of Ba 3D with nitric oxide

International Nuclear Information System (INIS)

Johnson, S.A.; Solarz, R.W.; Dubrin, J.W.; Brotzmann, R.

1977-01-01

The reaction of laser excited Ba*( 3 D) states with nitric oxide is presented. BaO product is not detected, although the channel is thermodynamically open, and instead chemiluminescence is observed. Experiments which suggest that radiative recombination, Ba + NO → BaNO* → BaNO, is the observed reaction channel will also be presented

Radiation effects on chemiluminescence of resting and immunologically activated alveolar macrophages

International Nuclear Information System (INIS)

Benichou, G.; Dormont, D.; Herodin, F.; Pasquier, C.; Hopital Saint Antoine, 75 - Paris

1986-01-01

In resting cells, for low radiation doses, a transient activation of chemiluminescence was observed, maximal at 3 Gy. At 10 Gy, CL returned to the control value; greater doses (above 30 Gy) induced a progressive diminution of the response which was abolished at 100 Gy. Activated alveolar macrophages showed a 30% decrease of the chemiluminescence at 10 Gy. The respiratory burst induced by opsonized zymosan was abolished at 30 Gy. IgG anti-MHC(IgGαB 1 ) activated specifically the GP S2 alveolar macrophages by alloantibody bipolar bridging; by contrast IgG which are directed against non-specific allogeneic determinants (IgG α B 3 ) or specific F(ab') 2 (F(ab') 2 αB 1 ) are unable to stimulate the cells. For all the tested doses, irradiation had no effect on this activation mechanism. The results with the three doses tested (3 Gy, 10 Gy, 30 Gy) are comparable to those using the positive control cells. The same results are obtained with the class II antigens and their specific IgG. (UK)

Recent advances in transition-metal-catalyzed intermolecular carbomagnesiation and carbozincation

Directory of Open Access Journals (Sweden)

Kei Murakami

2013-02-01

Full Text Available Carbomagnesiation and carbozincation reactions are efficient and direct routes to prepare complex and stereodefined organomagnesium and organozinc reagents. However, carbon–carbon unsaturated bonds are generally unreactive toward organomagnesium and organozinc reagents. Thus, transition metals were employed to accomplish the carbometalation involving wide varieties of substrates and reagents. Recent advances of transition-metal-catalyzed carbomagnesiation and carbozincation reactions are reviewed in this article. The contents are separated into five sections: carbomagnesiation and carbozincation of (1 alkynes bearing an electron-withdrawing group; (2 alkynes bearing a directing group; (3 strained cyclopropenes; (4 unactivated alkynes or alkenes; and (5 substrates that have two carbon–carbon unsaturated bonds (allenes, dienes, enynes, or diynes.

A Novel Technique for Generating and Observing Chemiluminescence in a Biological Setting

KAUST Repository

Büchel, Gabriel E.

2017-03-10

Intraoperative imaging techniques have the potential to make surgical interventions safer and more effective; for these reasons, such techniques are quickly moving into the operating room. Here, we present a new approach that utilizes a technique not yet explored for intraoperative imaging: chemiluminescent imaging. This method employs a ruthenium-based chemiluminescent reporter along with a custom-built nebulizing system to produce ex vivo or in vivo images with high signal-to-noise ratios. The ruthenium-based reporter produces light following exposure to an aqueous oxidizing solution and re-reduction within the surrounding tissue. This method has allowed us to detect reporter concentrations as low as 6.9 pmol/cm(2). In this work, we present a visual guide to our proof-of-concept in vivo studies involving subdermal and intravenous injections in mice. The results suggest that this technology is a promising candidate for further preclinical research and might ultimately become a useful tool in the operating room.

Electrogenerated chemiluminescence of luminol using low-cost electrodes

International Nuclear Information System (INIS)

Salgado, Guillermo; Navarrete, Jose; Bustos, Carlos; Sanchez, Cristian; Ugarte, Ricardo

2006-01-01

The purpose of the study was to observe eletrogenerated chemiluminescence (ECL) of luminol using different materials as electrodes such as wires, nails, coins, razor blades, etc. Based on the experimental observations and the mechanisms proposed in the literature, students should be capable of analyzing their results in order to understand the phenomena studied. Students could then elaborate a mechanism of action consistent with the experimental results which could rationalize the formation of intermediates in the reaction and the dependence of ECL on solution pH in addition to other points of interest. (author)

Advance directives as autonomy enhancers: reality or myth?

OpenAIRE

Navarro Michel, Mónica

2015-01-01

In the last few decades there has been a wealth of literature and legislation on advance directives. As you all know, it is an instrument by which a person can express their wishes as regards what treatment they should be given or, more to the point, not to be given, when he is in a situation when he can not do so himself. Regulations in the western world seem to promote advance directives as a way to enhance patient¿s autonomy in the context of human rights, and the media has presen...

Metal-core/semiconductor-shell nanocones for broadband solar absorption enhancement.

Science.gov (United States)

Zhou, Lin; Yu, Xiaoqiang; Zhu, Jia

2014-02-12

Nanostructure-based photovoltaic devices have exhibited several advantages, such as reduced reflection, extraordinary light trapping, and so forth. In particular, semiconductor nanostructures provide optical modes that have strong dependence on the size and geometry. Metallic nanostructures also attract a lot of attention because of the appealing plasmonic effect on the near-field enhancement. In this study, we propose a novel design, the metal-core/semiconductor-shell nanocones with the core radius varying in a linearly gradient style. With a thin layer of semiconductor absorber coated on a metallic cone, such a design can lead to significant and broadband absorption enhancement across the entire visible and near-infrared solar spectrum. As an example of demonstration, a layer of 16 nm thick crystalline silicon (c-Si) coated on a silver nanocone can absorb 27% of standard solar radiation across a broad spectral range of 300-1100 nm, which is equivalent to a 700 nm thick flat c-Si film. Therefore, the absorption enhancement factor approaching the Yablonovitch limit is achieved with this design. The significant absorption enhancement can be ascribed to three types of optical modes, that is, Fabry-Perot modes, plasmonic modes, and hybrid modes that combine the features of the previous two. In addition, the unique nanocone geometry enables the linearly gradient radius of the semiconductor shell, which can support multiple optical resonances, critical for the broadband absorption. Our design may find general usage as elements for the low cost, high efficiency solar conversion and water-splitting devices.

Molecularly imprinted polymer based on chemiluminescence imaging for the chiral recognition of dansyl-phenylalanine.

Science.gov (United States)

Wang, Li; Zhang, Zhujun; Huang, Lianggao

2008-03-01

A new molecularly imprinted polymer (MIP)-chemiluminescence (CL) imaging detection approach towards chiral recognition of dansyl-phenylalanine (Phe) is presented. The polymer microspheres were synthesized using precipitation polymerization with dansyl-L-Phe as template. Polymer microspheres were immobilized in microtiter plates (96 wells) using poly(vinyl alcohol) (PVA) as glue. The analyte was selectively adsorbed on the MIP microspheres. After washing, the bound fraction was quantified based on peroxyoxalate chemiluminescence (PO-CL) analysis. In the presence of dansyl-Phe, bis(2,4,6-trichlorophenyl)oxalate (TCPO) reacted with hydrogen peroxide (H2O2) to emit chemiluminescence. The signal was detected and quantified with a highly sensitive cooled charge-coupled device (CCD). Influencing factors were investigated and optimized in detail. Control experiments using capillary electrophoresis showed that there was no significant difference between the proposed method and the control method at a confidence level of 95%. The method can perform 96 independent measurements simultaneously in 30 min and the limits of detection (LODs) for dansyl-L-Phe and dansyl-D-Phe were 0.025 micromol L(-1) and 0.075 micromol L(-1) (3sigma), respectively. The relative standard deviation (RSD) for 11 parallel measurements of dansyl-L-Phe (0.78 micromol L(-1)) was 8%. The results show that MIP-based CL imaging can become a useful analytical technology for quick chiral recognition.

Performance Enhancements for Advanced Database Management Systems

OpenAIRE

Helmer, Sven

2000-01-01

New applications have emerged, demanding database management systems with enhanced functionality. However, high performance is a necessary precondition for the acceptance of such systems by end users. In this context we developed, implemented, and tested algorithms and index structures for improving the performance of advanced database management systems. We focused on index structures and join algorithms for set-valued attributes.

Soot and chemiluminescence in diesel combustion of bio-derived, oxygenated and reference fuels

NARCIS (Netherlands)

Klein-Douwel, R.J.H.; Donkerbroek, A.J.; Vliet, A.P. van; Boot, M.D.; Somers, L.M.T.; Baert, R.S.G.; Dam, N.J.; Meulen, J.J. ter

2009-01-01

High-speed imaging, spectroscopy and thermodynamical characterization are applied to an optically accessible, heavy-duty diesel engine in order to compare sooting and chemiluminescence behaviour of bio-derived, oxygenated fuels and various reference fuels. The fuels concerned include the bio-derived

Highly sensitive C-reactive protein (CRP) assay using metal-enhanced fluorescence (MEF)

International Nuclear Information System (INIS)

Zhang, Yi; Keegan, Gemma L.; Stranik, Ondrej; Brennan-Fournet, Margaret E.; McDonagh, Colette

2015-01-01

Fluorescence has been extensively employed in the area of diagnostic immunoassays. A significant enhancement of fluorescence can be achieved when noble metal nanoparticles are placed in close proximity to fluorophores. This effect, referred to as metal-enhanced fluorescence (MEF), has the potential to produce immunoassays with a high sensitivity and a low limit of detection (LOD). In this study, we investigate the fluorescence enhancement effect of two different nanoparticle systems, large spherical silver nanoparticles (AgNPs) and gold edge-coated triangular silver nanoplates, and both systems were evaluated for MEF. The extinction properties and electric field enhancement of both systems were modeled, and the optimum system, spherical AgNPs, was used in a sandwich immunoassay for human C-reactive protein with a red fluorescent dye label. A significant enhancement in the fluorescence was observed, which corresponded to an LOD improvement of ∼19-fold compared to a control assay without AgNPs

Highly sensitive C-reactive protein (CRP) assay using metal-enhanced fluorescence (MEF)

Energy Technology Data Exchange (ETDEWEB)

Zhang, Yi; Keegan, Gemma L., E-mail: gemmakeegan@gmail.com [Dublin City University, School of Physical Sciences, Biomedical Diagnostics Institute (Ireland); Stranik, Ondrej [Leibniz Institute of Photonic Technology, Department of NanoBiophotonics (Germany); Brennan-Fournet, Margaret E. [CMP-EMSE, MOC, Department of Bioelectronics, Ecole Nationale Superieure des Mines (France); McDonagh, Colette [Dublin City University, School of Physical Sciences, Biomedical Diagnostics Institute (Ireland)

2015-07-15

Fluorescence has been extensively employed in the area of diagnostic immunoassays. A significant enhancement of fluorescence can be achieved when noble metal nanoparticles are placed in close proximity to fluorophores. This effect, referred to as metal-enhanced fluorescence (MEF), has the potential to produce immunoassays with a high sensitivity and a low limit of detection (LOD). In this study, we investigate the fluorescence enhancement effect of two different nanoparticle systems, large spherical silver nanoparticles (AgNPs) and gold edge-coated triangular silver nanoplates, and both systems were evaluated for MEF. The extinction properties and electric field enhancement of both systems were modeled, and the optimum system, spherical AgNPs, was used in a sandwich immunoassay for human C-reactive protein with a red fluorescent dye label. A significant enhancement in the fluorescence was observed, which corresponded to an LOD improvement of ∼19-fold compared to a control assay without AgNPs.

ADVANCED TECHNOLOGIES FOR STRIPPER GAS WELL ENHANCEMENT

International Nuclear Information System (INIS)

Charles M. Boyer II; Ronald J. MacDonald P.G.

2001-01-01

As part of Task 1 in Advanced Technologies for Stripper Gas Well Enhancement, Schlumberger-Holditch Reservoir Technologies (H-RT) has joined with two Appalachian Basin producers, Great Lakes Energy Partners, LLC, and Belden and Blake Corporation to develop methodologies for identification and enhancement of stripper wells with economic upside potential. These industry partners have provided us with data for more than 700 wells in northwestern Pennsylvania. Phase 1 goals of this project are to develop and validate methodologies that can quickly and cost-effectively identify wells with enhancement potential. We are currently in the final stages of developing and testing our new Microsoft(trademark) Access/Excel based software. We will be processing this well data and identifying potential candidate wells that can be used in Phase 2 to validate these methodologies. Preparation of the final technical report is underway

Hollow metal nanostructures for enhanced plasmonics (Conference Presentation)

Science.gov (United States)

Genç, Aziz; Patarroyo, Javier; Sancho-Parramon, Jordi; Duchamp, Martial; Gonzalez, Edgar; Bastus, Neus G.; Houben, Lothar; Dunin-Borkowski, Rafal; Puntes, Victor F.; Arbiol, Jordi

2016-03-01

Complex metal nanoparticles offer a great playground for plasmonic nanoengineering, where it is possible to cover plasmon resonances from ultraviolet to near infrared by modifying the morphologies from solid nanocubes to nanoframes, multiwalled hollow nanoboxes or even nanotubes with hybrid (alternating solid and hollow) structures. We experimentally show that structural modifications, i.e. void size and final morphology, are the dominant determinants for the final plasmonic properties, while compositional variations allow us to get a fine tuning. EELS mappings of localized surface plasmon resonances (LSPRs) reveal an enhanced plasmon field inside the voids of hollow AuAg nanostructures along with a more homogeneous distributions of the plasmon fields around the nanostructures. With the present methodology and the appropriate samples we are able to compare the effects of hybridization at the nanoscale in hollow nanostructures. Boundary element method (BEM) simulations also reveal the effects of structural nanoengineering on plasmonic properties of hollow metal nanostructures. Possibility of tuning the LSPR properties of hollow metal nanostructures in a wide range of energy by modifying the void size/shell thickness is shown by BEM simulations, which reveals that void size is the dominant factor for tuning the LSPRs. As a proof of concept for enhanced plasmonic properties, we show effective label free sensing of bovine serum albumin (BSA) with some of our hollow nanostructures. In addition, the different plasmonic modes observed have also been studied and mapped in 3D.

Enhanced Endosomal Escape by Light-Fueled Liquid-Metal Transformer.

Science.gov (United States)

Lu, Yue; Lin, Yiliang; Chen, Zhaowei; Hu, Quanyin; Liu, Yang; Yu, Shuangjiang; Gao, Wei; Dickey, Michael D; Gu, Zhen

2017-04-12

Effective endosomal escape remains as the "holy grail" for endocytosis-based intracellular drug delivery. To date, most of the endosomal escape strategies rely on small molecules, cationic polymers, or pore-forming proteins, which are often limited by the systemic toxicity and lack of specificity. We describe here a light-fueled liquid-metal transformer for effective endosomal escape-facilitated cargo delivery via a chemical-mechanical process. The nanoscale transformer can be prepared by a simple approach of sonicating a low-toxicity liquid-metal. When coated with graphene quantum dots (GQDs), the resulting nanospheres demonstrate the ability to absorb and convert photoenergy to drive the simultaneous phase separation and morphological transformation of the inner liquid-metal core. The morphological transformation from nanospheres to hollow nanorods with a remarkable change of aspect ratio can physically disrupt the endosomal membrane to promote endosomal escape of payloads. This metal-based nanotransformer equipped with GQDs provides a new strategy for facilitating effective endosomal escape to achieve spatiotemporally controlled drug delivery with enhanced efficacy.

Advanced Melting Technologies: Energy Saving Concepts and Opportunities for the Metal Casting Industry

Energy Technology Data Exchange (ETDEWEB)

none,

2005-11-01

The study examines current and emerging melting technologies and discusses their technical barriers to scale-up issues and research needed to advance these technologies, improving melting efficiency, lowering metal transfer heat loss, and reducing scrap.

Finite Element Method Simulations of the Near-Field Enhancement at the Vicinity of Fractal Rough Metallic Surfaces

International Nuclear Information System (INIS)

Micic, Miodrag; Klymyshyn, Nicholas A.; Lu, H Peter

2004-01-01

Near-field optical enhancement at metal surfaces and methods such as surface plasmon resonance (SPR), surface-enhanced Raman scattering (SERS), fluorescent quenching and enhancement, and various near-field scanning microscopies (NSOM) all depend on a metals surface properties, mainly on its morphology and SPR resonant frequency. We report on simulations of the influence of different surface morphologies on electromagnetic field enhancements at the rough surfaces of noble metals and also evaluate the optimal conditions for the generation of a surface-enhanced Raman signal of absorbed species on a metallic substrate. All simulations were performed with a classical electrodynamics approach using the full set of Maxwells equations, which were solved with the three-dimensional finite element method (FEM). Two different classes of surfaces where modeled using fractals, representing diffusion limited aggregation growth dendritic structures, such as one on the surface of electrodes, and second one representing the sponge-like structure used to model surfaces of particles with high porosity, such as metal coated catalyst supports. The simulations depict the high inhomogeneity of an enhanced electromagnetic field as both a field enhancement and field attenuation near the surface. While the diffusion limited aggregation dendritical fractals enhanced the near-field electromagnetic field, the sponge fractals significantly reduced the local electromagnetic field intensity. Moreover, the fractal orders of the fractal objects did not significantly alter the total enhancement, and the distribution of a near-field enhancement was essentially invariant to the changes in the angle of an incoming laser beam

Rechargeable dual-metal-ion batteries for advanced energy storage.

Science.gov (United States)

Yao, Hu-Rong; You, Ya; Yin, Ya-Xia; Wan, Li-Jun; Guo, Yu-Guo

2016-04-14

Energy storage devices are more important today than any time before in human history due to the increasing demand for clean and sustainable energy. Rechargeable batteries are emerging as the most efficient energy storage technology for a wide range of portable devices, grids and electronic vehicles. Future generations of batteries are required to have high gravimetric and volumetric energy, high power density, low price, long cycle life, high safety and low self-discharge properties. However, it is quite challenging to achieve the above properties simultaneously in state-of-the-art single metal ion batteries (e.g. Li-ion batteries, Na-ion batteries and Mg-ion batteries). In this contribution, hybrid-ion batteries in which various metal ions simultaneously engage to store energy are shown to provide a new perspective towards advanced energy storage: by connecting the respective advantages of different metal ion batteries they have recently attracted widespread attention due to their novel performances. The properties of hybrid-ion batteries are not simply the superposition of the performances of single ion batteries. To enable a distinct description, we only focus on dual-metal-ion batteries in this article, for which the design and the benefits are briefly discussed. We enumerate some new results about dual-metal-ion batteries and demonstrate the mechanism for improving performance based on knowledge from the literature and experiments. Although the search for hybrid-ion batteries is still at an early age, we believe that this strategy would be an excellent choice for breaking the inherent disadvantages of single ion batteries in the near future.

Electrochemiluminescence and chemiluminescence of a carboxylic acid derivative of ruthenium(II) tris-(2,2'-bipyridine) chelate synthesized for labeling purposes

International Nuclear Information System (INIS)

Jiang Qinghong; Sun Shiguo; Hakansson, Markus; Langel, Kaarina; Ylinen, Tiina; Suomi, Johanna; Kulmala, Sakari

2006-01-01

Synthesis, purification and characterization of [4-ethoxycarbonyl-4'-carboxy-2,2'-bipyridine]bis(2,2'-bipyridine) ruthenium(II) hexafluorophosphate is described. This complex is shown to be electrochemiluminescent in aqueous solution during cathodic pulse polarization of thin insulating film-coated electrodes. Electrochemiluminescence (ECL) lifetime of the complex was observed to be ca. 40 μs at oxide-coated n-silicon electrodes; thus time-resolved detection is also possible. The ECL emission maximum of this carboxylate derivative is somewhat red-shifted when compared with an unmodified Ru(bpy) 3 2+ . Because the present complex can be easily covalently coupled with antibodies and oligonucleotides it is usable as an electrochemiluminescent label in various bioaffinity assays. The present chelates also produce strong chemiluminescence during dissolution of metallic magnesium in aqueous solution

Detection of γ-irradiation of foods. Use of H2O2-stimulated and photostimulated chemiluminescence. Pt. 1

International Nuclear Information System (INIS)

Lewin, G.; Popov, I.N.; Schreiber, G.A.; Helle, N.

1993-01-01

Beside methods for unequivocal identification of irradiation treatment of food screening methods which do not always give a final answer are needed for an effective control. In this paper preliminary results are presented which were obtained by measurement of the H 2 O 2 -stimulated and photostimulated chemiluminescence of apples treated by ionising radiation. Appels were chosen as a model for fresh fruit and vegetables. It seems that the H 2 O 2 -stimulated chemiluminescence can be used to screen fruit and vegetables to detect irradiation treatment. (orig.) [de

Origin of Shear Stability and Compressive Ductility Enhancement of Metallic Glasses by Metal Coating

Science.gov (United States)

Sun, B. A.; Chen, S. H.; Lu, Y. M.; Zhu, Z. G.; Zhao, Y. L.; Yang, Y.; Chan, K. C.; Liu, C. T.

2016-01-01

Metallic glasses (MGs) are notorious for the poor macroscopic ductility and to overcome the weakness various intrinsic and extrinsic strategies have been proposed in past decades. Among them, the metal coating is regarded as a flexible and facile approach, yet the physical origin is poorly understood due to the complex nature of shear banding process. Here, we studied the origin of ductile enhancement in the Cu-coating both experimentally and theoretically. By examining serrated shear events and their stability of MGs, we revealed that the thin coating layer plays a key role in stopping the final catastrophic failure of MGs by slowing down shear band dynamics and thus retarding its attainment to a critical instable state. The mechanical analysis on interplay between the coating layer and shear banding process showed the enhanced shear stability mainly comes from the lateral tension of coating layer induced by the surface shear step and the bonding between the coating layer and MGs rather than the layer thickness is found to play a key role in contributing to the shear stability. PMID:27271435

ADVANCED TECHNOLOGIES FOR STRIPPER GAS WELL ENHANCEMENT

International Nuclear Information System (INIS)

Charles M. Boyer II; Ronald J. MacDonald P.G.

2002-01-01

As part of Task 1 in Advanced Technologies for Stripper Gas Well Enhancement, Schlumberger-Holditch Reservoir Technologies (H-RT) has joined with two Appalachian Basin producers, Great Lakes Energy Partners, LLC, and Belden and Blake Corporation to develop methodologies for identification and enhancement of stripper wells with economic upside potential. These industry partners have provided us with data for more than 700 wells in northwestern Pennsylvania. Phase 1 goals of this project are to develop and validate methodologies that can quickly and cost-effectively identify wells with enhancement potential. We have continued to enhance and streamline our software, and we are testing the final stages of our new Microsoft(trademark) Access/Excel based software. We are continuing to process the information and are identifying potential candidate wells that can be used in Phase 2 to validate the new methodologies. In addition, preparation of the final technical report is underway. During this quarter, we have presented our project and discussed the software to numerous Petroleum Technology Transfer Council (PTTC) workshops located in various regions of the United States

Enhanced photochemistry on metal surfaces

International Nuclear Information System (INIS)

Goncher, G.M.; Parsons, C.A.; Harris, C.B.

1984-01-01

Due to the fast relaxation of molecular excited states in the vicinity of a metal or semiconductor surface, few observations of surface photochemistry have been reported. The following work concerns the surface-enhanced photo-reactions of a variety of physisorbed molecules on roughened Ag surfaces. In summary, photodecomposition leads to a graphitic surface carbon product which is monitored via surface-enhanced Raman scattering. In most cases an initial two-photon molecular absorption step followed by further absorption and fragmentation is thought to occur. Enhancement of the incident fields occurs through roughness-mediated surface plasmon resonances. This mechanism provides the amplified electromagnetic surface fields responsible for the observed photodecomposition. The photodecomposition experiments are performed under ultra-high vacuum. Surface characterization of the roughened surfaces was done by Scanning Electron Microscopy (SEM), and electron-stimulated emission. The SEM revealed morphology on the order of 300-400 A. This size of roughness feature, when modelled as isolated spheres should exhibit the well-known Mie resonances for light of the correct wavelengths. For protrusions existing on a surface these Mie resonances can be thought of as a coupling of the light with the surface plasmon. Experimental verification of these resonances was provided by the electron-stimulated light emission results. These showed that a polished Ag surface emitted only the expected transition radiation at the frequency of the Ag bulk plasmon. Upon roughening, however, a broad range of lower frequencies extending well into the visible are seen from electron irradiation of the surface. Large enhancements are expected for those frequencies which are able to couple into the surface modes

Lightweight, High Strength Metals With Enhanced Radiation Shielding - Technology Advancing Partnerships Challenge

Data.gov (United States)

National Aeronautics and Space Administration — The Technology Advancing Partnership (TAP) Challenge will seek to foster innovation throughout the Center by allowing the KSC workforce to identify a specific...

Metal Nanoshells for Plasmonically Enhanced Solar to Fuel Photocatalytic Conversion

Science.gov (United States)

2016-05-18

transfer, we anticipate this interlayer will modulate charge transfer from the metal to the semiconductor and vice versa. These new core-shell particles ...enhancement mechanism. In an extensive study using ten different samples, we found that GS-NS@ZIS particles with an LSPR absorption at ~700 nm and a silica...then coated with a thin layer of silica (SiO2), followed by a zinc indium sulfide (ZnIn2S4; ZIS) semiconductor shell. The blended-metal GS-NS cores

Layered double hydroxide-enhanced luminescence in a Fenton-like system for selective sensing of cobalt in Hela cells

Science.gov (United States)

Yu, Mei; Yuan, Zhiqin; Lu, Chao

2017-09-01

This work presented a facile and eco-friendly method for the determination of cobalt ions (Co(II)) in living cells based on layered double hydroxides (Mg-Al CO3-LDHs) enhanced chemiluminescence (CL) emission of a Co(II)-hydrogen peroxide-sodium hydroxide system. The enhanced CL emission was attributed to the large specific surface area of Mg-Al CO3-LDHs, which facilitates the generation of an excited-stated intermediate. The proposed method displayed high selectivity toward Co(II) over other metal ions. Under the optimal conditions, the increased CL intensity showed a linear response versus Co(II) concentration in the range of 5.0-1000 nM with a detection limit of 3.7 nM (S/N = 3). The relative standard deviation for nine repeated measurements of 100 nM Co(II) was 3.2%. Furthermore, the proposed method was successfully applied to detect Co(II) in living cell samples, and the results were agreed with those obtained by the standard ICP-MS method.

Advances in metal-induced oxidative stress and human disease

International Nuclear Information System (INIS)

Jomova, Klaudia; Valko, Marian

2011-01-01

Detailed studies in the past two decades have shown that redox active metals like iron (Fe), copper (Cu), chromium (Cr), cobalt (Co) and other metals undergo redox cycling reactions and possess the ability to produce reactive radicals such as superoxide anion radical and nitric oxide in biological systems. Disruption of metal ion homeostasis may lead to oxidative stress, a state where increased formation of reactive oxygen species (ROS) overwhelms body antioxidant protection and subsequently induces DNA damage, lipid peroxidation, protein modification and other effects, all symptomatic for numerous diseases, involving cancer, cardiovascular disease, diabetes, atherosclerosis, neurological disorders (Alzheimer's disease, Parkinson's disease), chronic inflammation and others. The underlying mechanism of action for all these metals involves formation of the superoxide radical, hydroxyl radical (mainly via Fenton reaction) and other ROS, finally producing mutagenic and carcinogenic malondialdehyde (MDA), 4-hydroxynonenal (HNE) and other exocyclic DNA adducts. On the other hand, the redox inactive metals, such as cadmium (Cd), arsenic (As) and lead (Pb) show their toxic effects via bonding to sulphydryl groups of proteins and depletion of glutathione. Interestingly, for arsenic an alternative mechanism of action based on the formation of hydrogen peroxide under physiological conditions has been proposed. A special position among metals is occupied by the redox inert metal zinc (Zn). Zn is an essential component of numerous proteins involved in the defense against oxidative stress. It has been shown, that depletion of Zn may enhance DNA damage via impairments of DNA repair mechanisms. In addition, Zn has an impact on the immune system and possesses neuroprotective properties. The mechanism of metal-induced formation of free radicals is tightly influenced by the action of cellular antioxidants. Many low-molecular weight antioxidants (ascorbic acid (vitamin C), alpha

Formation and Evolution of Carbon-Enhanced Metal-Poor Stars

NARCIS (Netherlands)

Abate, C.; Pols, O.R.; Izzard, R.G.

2010-01-01

Very metal-poor stars observed in the Galactic halo constitute a window on the primordial conditions under which the Milky Way was formed. A large fraction of these stars show a great enhancement in the abundance of carbon and other heavy elements. One explanation of this observation is that these

Insights into the ninhydrin chemiluminescent reaction and its potential for micromolar determination of human serum albumin

Energy Technology Data Exchange (ETDEWEB)

Alvarez, M. Rodriguez [Department of Physical and Analytical Chemistry, Faculty of Chemistry, University of Oviedo, Av. Julian Claveria, 8 33006 Oviedo (Spain); Laino, R. Badia [Department of Physical and Analytical Chemistry, Faculty of Chemistry, University of Oviedo, Av. Julian Claveria, 8 33006 Oviedo (Spain); Diaz-Garcia, M.E. [Department of Physical and Analytical Chemistry, Faculty of Chemistry, University of Oviedo, Av. Julian Claveria, 8 33006 Oviedo (Spain)]. E-mail: medg@uniovi.es

2006-06-15

The N-terminal region of human serum albumin (HSA) has an inherent affinity for Co(II) ions. On this basis a new continuous flow method for detection of HSA has been developed taking advantage of the strong quenching effect of the albumin in the ninhydrin-H{sub 2}O{sub 2}-Co(II) chemiluminescent system. The analytical potential of the system is compared with other conventional chemiluminescent reagents. The method gives linear responses from the detection limit (0.30 {mu}M HSA) up to 6.8 {mu}M. The repeatability of the method is good (RSD=7%), it is cheap and rapid to apply and does not require the use of insoluble or expensive reagents nor sophisticated equipment.

Role of organic amendments on enhanced bioremediation of heavy metal(loid) contaminated soils.

Science.gov (United States)

Park, Jin Hee; Lamb, Dane; Paneerselvam, Periyasamy; Choppala, Girish; Bolan, Nanthi; Chung, Jae-Woo

2011-01-30

As land application becomes one of the important waste utilization and disposal practices, soil is increasingly being seen as a major source of metal(loid)s reaching food chain, mainly through plant uptake and animal transfer. With greater public awareness of the implications of contaminated soils on human and animal health there has been increasing interest in developing technologies to remediate contaminated sites. Bioremediation is a natural process which relies on soil microorganisms and higher plants to alter metal(loid) bioavailability and can be enhanced by addition of organic amendments to soils. Large quantities of organic amendments, such as manure compost, biosolid and municipal solid wastes are used as a source of nutrients and also as a conditioner to improve the physical properties and fertility of soils. These organic amendments that are low in metal(loid)s can be used as a sink for reducing the bioavailability of metal(loid)s in contaminated soils and sediments through their effect on the adsorption, complexation, reduction and volatilization of metal(loid)s. This review examines the mechanisms for the enhanced bioremediation of metal(loid)s by organic amendments and discusses the practical implications in relation to sequestration and bioavailability of metal(loid)s in soils. Copyright © 2010 Elsevier B.V. All rights reserved.

Recent advancements in plasmon-enhanced promising third-generation solar cells

Directory of Open Access Journals (Sweden)

Thrithamarassery Gangadharan Deepak

2016-08-01

Full Text Available The unique optical properties possessed by plasmonic noble metal nanostructures in consequence of localized surface plasmon resonance (LSPR are useful in diverse applications like photovoltaics, sensing, non-linear optics, hydrogen generation, and photocatalytic pollutant degradation. The incorporation of plasmonic metal nanostructures into solar cells provides enhancement in light absorption and scattering cross-section (via LSPR, tunability of light absorption profile especially in the visible region of the solar spectrum, and more efficient charge carrier separation, hence maximizing the photovoltaic efficiency. This review discusses about the recent development of different plasmonic metal nanostructures, mainly based on Au or Ag, and their applications in promising third-generation solar cells such as dye-sensitized solar cells, quantum dot-based solar cells, and perovskite solar cells.

Analyzer for measurement of nitrogen oxide concentration by ozone content reduction in gas using solid state chemiluminescent sensor

Science.gov (United States)

Chelibanov, V. P.; Ishanin, G. G.; Isaev, L. N.

2014-05-01

Role of nitrogen oxide in ambient air is described and analyzed. New method of nitrogen oxide concentration measurement in gas phase is suggested based on ozone concentration measurement with titration by nitrogen oxide. Research of chemiluminescent sensor composition is carried out on experimental stand. The sensor produced on the base of solid state non-activated chemiluminescent composition is applied as ozone sensor. Composition is put on the surface of polymer matrix with developed surface. Sensor compositions includes gallic acid with addition of rodamine-6G. Model of interaction process between sensor composition and ozone has been developed, main products appeared during reaction are identified. The product determining the speed of luminescense appearance is found. This product belongs to quinone class. Then new structure of chemiluminescent composition was suggested, with absence of activation period and with high stability of operation. Experimental model of gas analyzer was constructed and operation algorithm was developed. It was demonstrated that developed NO measuring instrument would be applied for monitoring purposes of ambient air. This work was partially financially supported by Government of Russian Federation, Grant 074-U01

Induction skull melting facility: an advanced system for electromagnetic processing of metals and alloys

International Nuclear Information System (INIS)

Sugilal, G.; Agarwal, K.

2017-01-01

Induction Skull Melting (ISM) is an advanced technology for processing highly refractory and extremely reactive metals and their alloys to produce ultra-high purity products. In ISM, the metallic charge is melted in a water-cooled, copper crucible. The crucible is segmented so that the magnetic field can penetrate into the metallic charge to be melted. By virtue of the strong electromagnetic stirring, the ISM technology can also be used to homogenize alloys of metals, which are difficult to be combined uniformly in composition due to large difference in specific gravity. In view of various important applications in frontier areas of material research, development and production, Bhabha Atomic Research Centre developed the ISM technology indigenously

Light-enhanced acid catalysis over a metal-organic framework.

Science.gov (United States)

Xu, Caiyun; Sun, Keju; Zhou, Yu-Xiao; Ma, Xiao; Jiang, Hai-Long

2018-03-06

A Brønsted acid-functionalized metal-organic framework (MOF), MIL-101-SO 3 H, was prepared for acid-engaged esterification reactions. Strikingly, for the first time, the MOF exhibits significantly light-enhanced activity and possesses excellent activity and recyclability, with even higher activity than H 2 SO 4 under light irradiation.

Metallic stents provide better QOL than plastic stents in patients with stricture of unresectable advanced esophageal cancer

International Nuclear Information System (INIS)

Ohta, Kazuki; Nagahara, Akihito; Iijima, Katsuyori

2006-01-01

The aim of this study was to elucidate the utility and safety of treatment with esophageal stents (plastic and metallic stents) for unresectable advanced esophageal cancer. Between 1992 and 2002, 14 cases of unresectable advanced esophageal cancer were treated with esophageal stents (the plastic stent group, 7 cases; and the metallic stent group, 7 cases). Of these, 10 cases had a history of chemotherapy and or radiotherapy. An improvement in oral intake and performance status (PS), survival time, periods at home, and adverse events were compared between the two groups. After stenting, oral intake and PS were significantly improved in the metallic stent group. Follow-up at home was possible in 71.4%. There was no significant difference in survival or duration of time at home between the two groups. All adverse events were controllable and there was no difference between the two groups. Stenting not only improved oral intake and PS but also allowed a stay at home, resulting in a marked improvement in patients' quality of life (QOL). Stenting was performed safely even in cases with a history of radiotherapy. There was no difference in survival, ratios of staying at home, and safety between the two groups, but QOL was significantly improved in the metallic stent group. These outcomes indicate that placement of metallic stents should be actively considered to treat stricture due to advanced esophageal cancer. (author)

Chelation: Harnessing and Enhancing Heavy Metal Detoxification—A Review

Directory of Open Access Journals (Sweden)

Margaret E. Sears

2013-01-01

Full Text Available Toxic metals such as arsenic, cadmium, lead, and mercury are ubiquitous, have no beneficial role in human homeostasis, and contribute to noncommunicable chronic diseases. While novel drug targets for chronic disease are eagerly sought, potentially helpful agents that aid in detoxification of toxic elements, chelators, have largely been restricted to overt acute poisoning. Chelation, that is multiple coordination bonds between organic molecules and metals, is very common in the body and at the heart of enzymes with a metal cofactor such as copper or zinc. Peptides glutathione and metallothionein chelate both essential and toxic elements as they are sequestered, transported, and excreted. Enhancing natural chelation detoxification pathways, as well as use of pharmaceutical chelators against heavy metals are reviewed. Historical adverse outcomes with chelators, lessons learned in the art of using them, and successes using chelation to ameliorate renal, cardiovascular, and neurological conditions highlight the need for renewed attention to simple, safe, inexpensive interventions that offer potential to stem the tide of debilitating, expensive chronic disease.

Studies on an advanced repository system with enhanced engineered barriers (a framework)

International Nuclear Information System (INIS)

Fujiwara, A.; Tashiro, S.; Ikari, S.; Suzuki, A.

1993-01-01

In order to propose advanced designs of repositories with enhanced engineered barriers of relatively high radioactive wastes such as burnable poisons, channel boxes, control rods and highly irradiated metals, studies started in 1987 and completed the first phase in 1992. This paper presents the framework and brief results of the first phase. The studies set preliminary design concepts of the repositories with various combinations with engineered barriers and natural barriers for different models and locations such as a silo type in shallow land or a tunnel type in intermediate depth. Through the designs, four component technics were picked up and studied for (1) construction of the components in repository; (2) performance evaluation to realize repository design; (3) improvement of circumstances inside or around repository; and (4) surveillance of repository performance to realize the repository designs. Finally, some repository systems were provided using obtained results, and then the applicability and the economy were evaluated. The studies will continue to the second phase focusing on the long-term performance of the repositories

Recent advances in metal oxide-based electrode architecture design for electrochemical energy storage.

Science.gov (United States)

Jiang, Jian; Li, Yuanyuan; Liu, Jinping; Huang, Xintang; Yuan, Changzhou; Lou, Xiong Wen David

2012-10-02

Metal oxide nanostructures are promising electrode materials for lithium-ion batteries and supercapacitors because of their high specific capacity/capacitance, typically 2-3 times higher than that of the carbon/graphite-based materials. However, their cycling stability and rate performance still can not meet the requirements of practical applications. It is therefore urgent to improve their overall device performance, which depends on not only the development of advanced electrode materials but also in a large part "how to design superior electrode architectures". In the article, we will review recent advances in strategies for advanced metal oxide-based hybrid nanostructure design, with the focus on the binder-free film/array electrodes. These binder-free electrodes, with the integration of unique merits of each component, can provide larger electrochemically active surface area, faster electron transport and superior ion diffusion, thus leading to substantially improved cycling and rate performance. Several recently emerged concepts of using ordered nanostructure arrays, synergetic core-shell structures, nanostructured current collectors, and flexible paper/textile electrodes will be highlighted, pointing out advantages and challenges where appropriate. Some future electrode design trends and directions are also discussed. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A novel luminol chemiluminescent method catalyzed by silver/gold alloy nanoparticles for determination of anticancer drug flutamide.

Science.gov (United States)

Chaichi, Mohammad Javad; Azizi, Seyed Naser; Heidarpour, Maryam

2013-12-01

It was found that silver/gold alloy nanoparticles enhance the chemiluminescence (CL) of the luminol-H2O2 system in alkaline solution. The studies of UV-Vis spectra, CL spectra, effects of concentrations luminol, hydrogen peroxide and silver/gold alloy nanoparticles solutions were carried out to explore the CL enhancement mechanism. Flutamide was found to quench the CL signals of the luminol-H2O2 reaction catalyzed by silver/gold alloy nanoparticles, which made it applicable for the determination of flutamide. Under the optimum conditions, the CL intensity is proportional to the concentration of the flutamide in solution over the range 5.0 × 10(-7) to 1.0 × 10(-4)mol L(-1). Detection limit was obtained 1.2 × 10(-8)mol L(-1)and the relative standard deviation (RSD) γ5%. This work is introduced as a new method for the determination of flutamide in commercial tablets. Box-Behnken experimental design is applied to investigate and validate the CL measurement parameters. Copyright © 2013 Elsevier B.V. All rights reserved.

Estimation of tritium activity in bioassay samples having chemiluminescence

International Nuclear Information System (INIS)

Dwivedi, R.K.; Manu, Kumar; Kumar, Vinay; Soni, Ashish; Kaushik, A.K.; Tiwari, S.K.; Gupta, Ashok

2008-01-01

Tritium is recognized as major internal dose contributor in PHWR type of reactors. Estimation of internal dose due to tritium is carried out by analyzing urine samples in liquid scintillation analyzer (LSA). Presence of residual biochemical species in urine samples of some individuals under medical administration shows significant amount of chemiluminescence. If appropriate care is not taken the results obtained by liquid scintillation counter may be mistaken as genuine uptake of tritium. The distillation method described in this paper is used at RAPS-3 and 4 to assess correct tritium uptake. (author)

Flow Injection Photosensitized Chemiluminescence of Luminol with Cu(II-Rose Bengal: Mechanistic Approach and Vitamin A and C Determination

Directory of Open Access Journals (Sweden)

Muhammad Asgher

2014-01-01

Full Text Available Rose Bengal photosensitized flow injection chemiluminescence method is reported using luminol-Cu(II for the determination of vitamins A and C in pharmaceutical formulations. The reaction is based on the enhancement effect of analyte in the production of anion radicals of Rose Bengal (RB•− which rapidly interact with dissolved oxygen and generate superoxide anions radicals (O2•− and hydrogen peroxide (H2O2. Highly reactive hydroxyl radicals (•OH were produced via dismutation of H2O2 by catalyst (Cu2+. The generated superoxide anions radicals and hydroxyl radicals thus oxidize luminol in alkaline medium to generate strong chemiluminescence. The limit of detection (3s of the blank, n=6 of vitamins A and C and RB was found to be 0.008, 0.005, and 0.05 μg mL−1, respectively. The sample throughput of 70 h−1 for vitamins A and C and 30 h−1 for RB was found. Calibration curve was linear in the range of 0.05–15, 0.01–20, and 0.1–50 μg mL−1 for vitamins A and C and RB, respectively, with relative standard deviations (RSDs; n=3 in the range 1.6–3.6%. The method was successfully applied to pharmaceutical formulations and the results obtained were in good agreement with the labeled values.

Comparison of natural organic acids and synthetic chelates at enhancing phytoextraction of metals from a multi-metal contaminated soil

International Nuclear Information System (INIS)

Clistenes do Nascimento, Williams A.; Amarasiriwardena, Dula; Xing, Baoshan

2006-01-01

Chemically assisted phytoremediation has been developing to induce accumulation of metals by high biomass plants. Synthetic chelates have shown high effectiveness to reach such a goal, but they pose serious drawbacks in field application due to the excessive amount of metals solubilized. We compared the performance of synthetic chelates with naturally occurring low molecular weight organic acids (LMWOA) in enhancing phytoextraction of metals by Indian mustard (Brassica juncea) from multi-metal contaminated soils. Gallic and citric acids were able to induce removal of Cd, Zn, Cu, and Ni from soil without increasing the leaching risk. Net removal of these metals caused by LMWOA can be as much as synthetic chelates. A major reason for this is the lower phytotoxicity of LMWOA. Furthermore, supplying appropriate mineral nutrients increased biomass and metal removal. - Organic acids can be as efficient as synthetic chelates for use in phytoextraction of multi-metal contaminated soils

Merging Metallic Catalysts and Sonication: A Periodic Table Overview

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Claudia E. Domini

2017-04-01

Full Text Available This account summarizes and discusses recent examples in which the combination of ultrasonic waves and metal-based reagents, including metal nanoparticles, has proven to be a useful choice in synthetic planning. Not only does sonication often enhance the activity of the metal catalyst/reagent, but it also greatly enhances the synthetic transformation that can be conducted under milder conditions relative to conventional protocols. For the sake of clarity, we have adopted a structure according to the periodic-table elements or families, distinguishing between bulk metal reagents and nanoparticles, as well as the supported variations, thus illustrating the characteristics of the method under consideration in target synthesis. The coverage focuses essentially on the last decade, although the discussion also strikes a comparative balance between the more recent advancements and past literature.

Flame Structure and Chemiluminescence Emissions of Inverse Diffusion Flames under Sinusoidally Driven Plasma Discharges

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Maria Grazia De Giorgi

2017-03-01

Full Text Available Reduction of nitric oxides (NOx in aircraft engines and in gas turbines by lean combustion is of great interest in the design of novel combustion systems. However, the stabilization of the flame under lean conditions is a main issue. In this context, the present work investigates the effects of sinusoidal dielectric barrier discharge (DBD on a lean inverse diffusive methane/air flame in a Bunsen-type burner under different actuation conditions. The flame appearance was investigated with fixed methane loading (mass flux, but with varying inner airflow rate. High-speed flame imaging was done by using an intensified (charge-coupled device CCD camera equipped with different optical filters in order to selectively record signals from the chemiluminescent species OH*, CH*, or CO2* to evaluate the flame behavior in presence of plasma actuation. The electrical power consumption was less than 33 W. It was evident that the plasma flame enhancement was significantly influenced by the plasma discharges, particularly at high inner airflow rates. The flame structure changes drastically when the dissipated plasma power increases. The flame area decreases due to the enhancement of mixing and chemical reactions that lead to a more anchored flame on the quartz exit with a reduction of the flame length.

Heat transfer enhancement in energy storage in spherical capsules filled with paraffin wax and metal beads

International Nuclear Information System (INIS)

Ettouney, Hisham; Alatiqi, Imad; Al-Sahali, Mohammad; Al-Hajirie, Khalida

2006-01-01

Energy storage is an attractive option to conserve limited energy resources, where more than 50% of the generated industrial energy is discarded in cooling water and stack gases. This study focuses on the evaluation of heat transfer enhancement in phase change energy storage units. The experiments are performed using spherical capsules filled with paraffin wax and metal beads. The experiments are conducted by inserting a single spherical capsule filled with wax and metal beads in a stream of hot/cold air. Experimental measurements include the temperature field within the spherical capsule and in the air stream. To determine the enhancement effects of the metal beads, the measured data is correlated against those for a spherical capsule filled with pure wax. Data analysis shows a reduction of 15% in the melting and solidification times upon increasing the number and diameter of the metal beads. This reduction is caused by a similar decrease in the thermal load of the sphere due to replacement of the wax by metal beads. The small size of the spherical capsule limits the enhancement effects; this is evident upon comparison of the heat transfer in a larger size, double pipe energy storage unit, where 2% of the wax volume is replaced with metal inserts, result in a three fold reduction in the melting/solidification time and a similar enhancement in the heat transfer rate

Streptavidin-functionalized capillary immune microreactor for highly efficient chemiluminescent immunoassay

Energy Technology Data Exchange (ETDEWEB)

Yang Zhanjun [State Key Laboratory of Analytical Chemistry for Life Science, Department of Chemistry, Nanjing University, Nanjing 210093 (China); College of Chemistry and Engineering, Yangzhou University, 88 South University Avenue, Yangzhou 225002 (China); Zong Chen [State Key Laboratory of Analytical Chemistry for Life Science, Department of Chemistry, Nanjing University, Nanjing 210093 (China); Ju Huangxian, E-mail: hxju@nju.edu.cn [State Key Laboratory of Analytical Chemistry for Life Science, Department of Chemistry, Nanjing University, Nanjing 210093 (China); Yan Feng, E-mail: yanfeng2007@sohu.com [Jiangsu Institute of Cancer Prevention and Cure, Nanjing 210009 (China)

2011-11-07

Highlights: {yields} A novel capillary immune microreactor was proposed for highly efficient flow-through chemiluminescent immunoassay. {yields} The microreactor was prepared by functionalizing capillary inner wall with streptavidin for capture of biotinylated antibody. {yields} The proposed immunoassay method showed wide dynamic range, good reproducibility, stability and practicality. {yields} The microreactor was low-cost and disposable, and possessed several advantages over the conventional immunoreactors. - Abstract: A streptavidin functionalized capillary immune microreactor was designed for highly efficient flow-through chemiluminescent (CL) immunoassay. The functionalized capillary could be used as both a support for highly efficient immobilization of antibody and a flow cell for flow-through immunoassay. The functionalized inner wall and the capture process were characterized using scanning electron microscopy. Compared to conventional packed tube or thin-layer cell immunoreactor, the proposed microreactor showed remarkable properties such as lower cost, simpler fabrication, better practicality and wider dynamic range for fast CL immunoassay with good reproducibility and stability. Using {alpha}-fetoprotein as model analyte, the highly efficient CL flow-through immunoassay system showed a linear range of 3 orders of magnitude from 0.5 to 200 ng mL{sup -1} and a low detection limit of 0.1 ng mL{sup -1}. The capillary immune microreactor could make up the shortcoming of conventional CL immunoreactors and provided a promising alternative for highly efficient flow-injection immunoassay.

Development of luminol-N-hydroxyphthalimide chemiluminescence system for highly selective and sensitive detection of superoxide dismutase, uric acid and Co2.

Science.gov (United States)

Saqib, Muhammad; Qi, Liming; Hui, Pan; Nsabimana, Anaclet; Halawa, Mohamed Ibrahim; Zhang, Wei; Xu, Guobao

2018-01-15

N-hydroxyphthalimide (NHPI), a well known reagent in organic synthesis and biochemical applications, has been developed as a stable and efficient chemiluminescence coreactant for the first time. It reacts with luminol much faster than N-hydroxysuccinimide, eliminating the need of a prereaction coil used in N-hydroxysuccinimide system. Without using prereaction coil, the chemiluminescence peak intensities of luminol-NHPI system are about 102 and 26 times greater than that of luminol-N-hydroxysuccinimide system and classical luminol-hydrogen peroxide system, respectively. The luminol-NHPI system achieves the highly sensitive detection of luminol (LOD = 70pM) and NHPI (LOD = 910nM). Based on their excellent quenching efficiencies, superoxide dismutase and uric acid are sensitively detected with LODs of 3ng/mL and 10pM, respectively. Co 2+ is also detected a LOD of 30pM by its remarkable enhancing effect. Noteworthily, our method is at least 4 orders of magnitude more sensitive than previously reported uric acid detection methods, and can detect uric acid in human urine and Co 2+ in tap and lake water real samples with excellent recoveries in the range of 96.35-102.70%. This luminol-NHPI system can be an important candidate for biochemical, clinical and environmental analysis. Copyright © 2017 Elsevier B.V. All rights reserved.

Irradiation monitoring of spices by chemiluminescence method

International Nuclear Information System (INIS)

Bhatti, K.A.; Khan, H.M.; Sattar, A.; Ahmad, A.

2001-01-01

Some spices (cumin, coriander, black pepper and red pepper), commonly used due to their specific aroma and nutritional value were studied using chemiluminescence (CL) method to test whether the food has been irradiated or not. The spices were ground to different mesh sizes and subjected to gamma ray doses of 2.5, 5.0, 7.5 and 10 Kgy. The effect of radiation doses and particle size on the CL response of irradiated and un-irradiated samples was checked using luminol and lucigenin sensitizers. The storage experiment was also performed for all spices with both the sensitizers in order to pick the suitable sensitizer for CL study. During this study Co-60 gamma ray source and Bio-orbit 1250 luminometer were used after precise calibration

Root Fungal Endophytes Enhance Heavy-Metal Stress Tolerance of Clethra barbinervis Growing Naturally at Mining Sites via Growth Enhancement, Promotion of Nutrient Uptake and Decrease of Heavy-Metal Concentration.

Directory of Open Access Journals (Sweden)

Keiko Yamaji

Full Text Available Clethra barbinervis Sieb. et Zucc. is a tree species that grows naturally at several mine sites and seems to be tolerant of high concentrations of heavy metals, such as Cu, Zn, and Pb. The purpose of this study is to clarify the mechanism(s underlying this species' ability to tolerate the sites' severe heavy-metal pollution by considering C. barbinervis interaction with root fungal endophytes. We measured the heavy metal concentrations of root-zone soil, leaves, branches, and fine roots collected from mature C. barbinervis at Hitachi mine. We isolated fungal endophytes from surface-sterilized root segments, and we examined the growth, and heavy metal and nutrient absorption of C. barbinervis seedlings growing in sterilized mine soil with or without root fungal endophytes. Field analyses showed that C. barbinervis contained considerably high amounts of Cu, Zn, and Pb in fine roots and Zn in leaves. The fungi, Phialocephala fortinii, Rhizodermea veluwensis, and Rhizoscyphus sp. were frequently isolated as dominant fungal endophyte species. Inoculation of these root fungal endophytes to C. barbinervis seedlings growing in sterilized mine soil indicated that these fungi significantly enhanced the growth of C. barbinervis seedlings, increased K uptake in shoots and reduced the concentrations of Cu, Ni, Zn, Cd, and Pb in roots. Without root fungal endophytes, C. barbinervis could hardly grow under the heavy-metal contaminated condition, showing chlorosis, a symptom of heavy-metal toxicity. Our results indicate that the tree C. barbinervis can tolerate high heavy-metal concentrations due to the support of root fungal endophytes including P. fortinii, R. veluwensis, and Rhizoscyphus sp. via growth enhancement, K uptake promotion and decrease of heavy metal concentrations.

Advanced technologies for decontamination and conversion of scrap metal

International Nuclear Information System (INIS)

Valerie MacNair; Steve Sarten; Thomas Muth; Brajendra Mishra

1999-01-01

The Department of Energy (DOE) faces the task of decommissioning much of the vast US weapons complex. One challenge of this effort includes the disposition of large amounts of radioactively contaminated scrap metal (RSM) including but not limited to steel, nickel, copper, and aluminum. The decontamination and recycling of RSM has become a key element in the DOE's strategy for cleanup of contaminated sites and facilities. Recycling helps to offset the cost of decommissioning and saves valuable space in the waste disposal facilities. It also reduces the amount of environmental effects associated with mining new metals. Work on this project is geared toward finding decontamination and/or recycling alternatives for the RSM contained in the decommissioned gaseous diffusion plants including approximately 40,000 tons of nickel. The nickel is contaminated with Technetium-99, and is difficult to remove using traditional decontamination technologies. The project, titled ''Advanced Technologies for Decontamination and Conversion of Scrap Metal'' was proposed as a four phase project. Phase 1 and 2 are complete and Phase 3 will complete May 31, 1999. Stainless steel made from contaminated nickel barrier was successfully produced in Phase 1. An economic evaluation was performed and a market study of potential products from the recycled metal was completed. Inducto-slag refining, after extensive testing, was eliminated as an alternative to remove technetium contamination from nickel. Phase 2 included successful lab scale and pilot scale demonstrations of electrorefining to separate technetium from nickel. This effort included a survey of available technologies to detect technetium in volumetrically contaminated metals. A new process to make sanitary drums from RSM was developed and implemented. Phase 3 included a full scale demonstration of electrorefining, an evaluation of electro-refining alternatives including direct dissolution, melting of nickel into anodes, a laser cutting

Raman scattering enhancement in photon-plasmon resonance mediated metal-dielectric microcavity

International Nuclear Information System (INIS)

Guddala, Sriram; Narayana Rao, D.; Dwivedi, Vindesh K.; Vijaya Prakash, G.

2013-01-01

Here, we report the photon-plasmon interaction scheme and enhanced field strengths resulted into the amplification of phonon in a novel microcavity. A metal-dielectric microcavity, with unified cavity photonic mode and localized surface plasmon resonances, is visualized by impregnating the gold nanoparticles into the deep see-through nano-sized pores of porous silicon microcavity. The intense optical field strengths resulting from the photon-plasmon interactions are probed by both resonant and non-resonant Raman scattering experiments. Due to photon-plasmon-phonon interaction mechanism, several orders of enhancement in the intensity of scattered Raman Stokes photon (at 500 cm −1 ) are observed. Our metal nanoparticle-microcavity hybrid system shows the potential to improve the sensing figure of merit as well as the applications of plasmonics for optoelectronics, photovoltaics, and related technologies

Enhancement of oxygen reduction at Fe tetrapyridyl porphyrin by pyridyl-N coordination to transition metal ions

International Nuclear Information System (INIS)

Maruyama, Jun; Baier, Claudia; Wolfschmidt, Holger; Bele, Petra; Stimming, Ulrich

2012-01-01

One of the promising candidates as noble-metal-free electrode catalysts for polymer electrolyte fuel cells (PEFCs) is a carbon material with nitrogen atoms coordinating iron ions embedded on the surface (Fe-N x moiety) as the active site, although the activity is insufficient compared to conventional platinum-based electrocatalysts. In order to obtain fundamental information on the activity enhancement, a simple model of the Fe-N x active site was formed by adsorbing 5,10,15,20-Tetrakis(4-pyridyl)-21H,23H-porphine iron(III) chloride (FeTPyPCl) on the basal plane of highly oriented pyrolytic graphite (HOPG), and cathodic oxygen reduction was investigated on the surface in 0.1 M HClO 4 . The catalytic activity for oxygen reduction was enhanced by loading transition metal ions (Co 2+ , Ni 2+ , Cu 2+ ) together with FeTPyPCl. The X-ray photoelectron spectrum of the surface suggested that the metal was coordinated by the pyridine-N. The enhancement effect of the transition metals was supported by two different measurements: oxygen reduction at HOPG in 0.1 M HClO 4 dissolving FeTPyPCl and the metal ions; oxygen reduction in 0.1 M HClO 4 at the subsequently well-rinsed and dried HOPG. The ultraviolet–visible spectrum for the solution also suggested the coordination between the pyridyl-N and the metal ions. The oxygen reduction enhancement was attributed to the electronic interaction between the additional transition metal and the Fe center of the porphyrin through the coordination bonds. These results implied that the improvement of the activity of the noble-metal-free catalyst would be possible by the proper introduction of the transition metal ions around the active site.

Application of a Chemiluminescence Detector for the Measurement of Total Oxides of Nitrogen and Ammonia in the Atmosphere

Science.gov (United States)

Hodgeson, J. A.; Bell, J. P.; Rehme, K. A.; Krost, K. J.; Stevens, R. K.

1971-01-01

By means of the thermal conversion of nitrogen dioxide to the nitric oxide, the chemiluminescent nitric oxide monitor, based on the nitric oxide plus ozone reaction, may be used for monitoring nitrogen dioxide plus nitric oxide (NO(x)). Under conditions previously described, ammonia is also converted to nitric oxide and therefore interferes. A metal surface, gold wool or stainless steel, operated at two different temperatures has been used to convert only nitrogen dioxide or nitrogen dioxide plus ammonia. Quantitative conversion of nitrogen dioxide to nitric oxide has been obtained at temperatures as low as 200 C. Conversion of ammonia is effected at temperatures of 300 C or higher. By the addition of a converter the basic nitric oxide monitor may be used for measuring NO(x) or NO(x) plus ammonia. As an alternate mode, for a fixed high temperature, a specific scrubber is described for removing NH3 without affecting NO2 concentrations.

Microspot-based ELISA in microfluidics: chemiluminescence and colorimetry detection using integrated thin-film hydrogenated amorphous silicon photodiodes.

Science.gov (United States)

Novo, Pedro; Prazeres, Duarte Miguel França; Chu, Virginia; Conde, João Pedro

2011-12-07

Microfluidic technology has the potential to decrease the time of analysis and the quantity of sample and reactants required in immunoassays, together with the potential of achieving high sensitivity, multiplexing, and portability. A lab-on-a-chip system was developed and optimized using optical and fluorescence microscopy. Primary antibodies are adsorbed onto the walls of a PDMS-based microchannel via microspotting. This probe antibody is then recognised using secondary FITC or HRP labelled antibodies responsible for providing fluorescence or chemiluminescent and colorimetric signals, respectively. The system incorporated a micron-sized thin-film hydrogenated amorphous silicon photodiode microfabricated on a glass substrate. The primary antibody spots in the PDMS-based microfluidic were precisely aligned with the photodiodes for the direct detection of the antibody-antigen molecular recognition reactions using chemiluminescence and colorimetry. The immunoassay takes ~30 min from assay to the integrated detection. The conditions for probe antibody microspotting and for the flow-through ELISA analysis in the microfluidic format with integrated detection were defined using antibody solutions with concentrations in the nM-μM range. Sequential colorimetric or chemiluminescence detection of specific antibody-antigen molecular recognition was quantitatively detected using the photodiode. Primary antibody surface densities down to 0.182 pmol cm(-2) were detected. Multiplex detection using different microspotted primary antibodies was demonstrated.

Enhancing phytoextraction: the effect of chemical soil manipulation on mobility, plant accumulation, and leaching of heavy metals.

Science.gov (United States)

Schmidt, Ulrich

2003-01-01

For heavy metal-contaminated agricultural land, low-cost, plant-based phytoextraction measures can be a key element for a new land management strategy. When agents are applied into the soil, the solubility of heavy metals and their subsequent accumulation by plants can be increased, and, therefore, phytoextraction enhanced. An overview is given of the state of the art of enhancing heavy metal solubility in soils, increasing the heavy metal accumulation of several high-biomass-yielding and metal-tolerant plants, and the effect of these measures on the risk of heavy metal leaching. Several organic as well as inorganic agents can effectively and specifically increase solubility and, therefore, accumulation of heavy metals by several plant species. Crops like willow (Salix viminalis L.), Indian mustard [Brassica juncea (L.) Czern.], corn (Zea mays L.), and sunflower (Helianthus annuus L.) show high tolerance to heavy metals and are, therefore, to a certain extent able to use the surpluses that originate from soil manipulation. More than 100-fold increases of lead concentrations in the biomass of crops were reported, when ethylenediaminetetraacetic acid (EDTA) was applied to contaminated soils. Uranium concentrations could be strongly increased when citric acid was applied. Cadmium and zinc concentrations could be enhanced by inorganic agents like elemental sulfur or ammonium sulfate. However, leaching of heavy metals due to increased mobility in soils cannot be excluded. Thus, implementation on the field scale must consider measures to minimize leaching. So, the application of more than 1 g EDTA kg(-1) becomes inefficient as lead concentration in crops is not enhanced and leaching rate increases. Moreover, for large-scale applications, agricultural measures as placement of agents, dosage splitting, the kind and amount of agents applied, and the soil properties are important factors governing plant growth, heavy metal concentrations, and leaching rates. Effective

Application of direct-injection detector integrated with the multi-pumping flow system to chemiluminescence determination of the total polyphenol index.

Science.gov (United States)

Nalewajko-Sieliwoniuk, Edyta; Iwanowicz, Magdalena; Kalinowski, Sławomir; Kojło, Anatol

2016-03-10

In this work, we present a novel chemiluminescence (CL) method based on direct-injection detector (DID) integrated with the multi-pumping flow system (MPFS) to chemiluminescence determination of the total polyphenol index. In this flow system, the sample and the reagents are injected directly into the cone-shaped detection cell placed in front of the photomultiplier window. Such construction of the detection chamber allows for fast measurement of the CL signal in stopped-flow conditions immediately after mixing the reagents. The proposed DID-CL-MPFS method is based on the chemiluminescence of nanocolloidal manganese(IV)-hexametaphosphate-ethanol system. The application of ethanol as a sensitizer, eliminated the use of carcinogenic formaldehyde. Under the optimized experimental conditions, the chemiluminescence intensities are proportional to the concentration of gallic acid in the range from 5 to 350 ng mL(-1). The DID-CL-MPFS method offers a number of advantages, including low limit of detection (0.80 ng mL(-1)), high precision (RSD = 3.3%) and high sample throughput (144 samples h(-1)) as well as low consumption of reagents, energy and low waste generation. The proposed method has been successfully applied to determine the total polyphenol index (expressed as gallic acid equivalent) in a variety of plant-derived food samples (wine, tea, coffee, fruit and vegetable juices, herbs, spices). Copyright © 2016 Elsevier B.V. All rights reserved.

Extraordinary Magnetic Field Enhancement with Metallic Nanowire: Role of Surface Impedance in Babinet's Principle for Sub-Skin-Depth Regime

Science.gov (United States)

Koo, Sukmo; Kumar, M. Sathish; Shin, Jonghwa; Kim, Daisik; Park, Namkyoo

2009-12-01

We propose and analyze the “complementary” structure of a metallic nanogap, namely, the metallic nanowire for magnetic field enhancement. A huge enhancement of the field up to a factor of 300 was achieved. Introducing the surface impedance concept, we also develop and numerically confirm a new analytic theory which successfully predicts the field enhancement factors for metal nanostructures. Compared to the predictions of the classical Babinet principle applied to a nanogap, an order of magnitude difference in the field enhancement factor was observed for the sub-skin-depth regime nanowire.

Aqueous nitrite ion determination by selective reduction and gas phase nitric oxide chemiluminescence

Science.gov (United States)

Dunham, A. J.; Barkley, R. M.; Sievers, R. E.; Clarkson, T. W. (Principal Investigator)

1995-01-01

An improved method of flow injection analysis for aqueous nitrite ion exploits the sensitivity and selectivity of the nitric oxide (NO) chemilluminescence detector. Trace analysis of nitrite ion in a small sample (5-160 microL) is accomplished by conversion of nitrite ion to NO by aqueous iodide in acid. The resulting NO is transported to the gas phase through a semipermeable membrane and subsequently detected by monitoring the photoemission of the reaction between NO and ozone (O3). Chemiluminescence detection is selective for measurement of NO, and, since the detection occurs in the gas-phase, neither sample coloration nor turbidity interfere. The detection limit for a 100-microL sample is 0.04 ppb of nitrite ion. The precision at the 10 ppb level is 2% relative standard deviation, and 60-180 samples can be analyzed per hour. Samples of human saliva and food extracts were analyzed; the results from a standard colorimetric measurement are compared with those from the new chemiluminescence method in order to further validate the latter method. A high degree of selectivity is obtained due to the three discriminating steps in the process: (1) the nitrite ion to NO conversion conditions are virtually specific for nitrite ion, (2) only volatile products of the conversion will be swept to the gas phase (avoiding turbidity or color in spectrophotometric methods), and (3) the NO chemiluminescence detector selectively detects the emission from the NO + O3 reaction. The method is free of interferences, offers detection limits of low parts per billion of nitrite ion, and allows the analysis of up to 180 microL-sized samples per hour, with little sample preparation and no chromatographic separation. Much smaller samples can be analyzed by this method than in previously reported batch analysis methods, which typically require 5 mL or more of sample and often need chromatographic separations as well.

l-Tyrosine Contained in Dietary Supplement by Chemiluminescence Reaction of an Iron-Phthalocyanine Complex

Directory of Open Access Journals (Sweden)

Takao Ohtomo

2012-01-01

Full Text Available The chemiluminescence (CL signal immediately appeared when a hydrogen peroxide solution was injected into an iron-phthalocyanine tetrasulfonic acid (Fe-PTS aqueous solution. Moreover, the CL intensity of Fe-PTS decreased by adding L-tyrosine. Based on these results, the determination of trace amounts of L-tyrosine was developed using the quenching-chemiluminescence. The calibration curve of L-tyrosine was obtained in the concentration range of 2.0×10−7 M to 2.0×10−5 M. Moreover, the relative standard deviation (RSD was 1.63 % (=5 for 2.0×10−6 M L-tyrosine, and its detection limits (3σ were 1.81×10−7 M. The spike and recovery experiments for L-tyrosine were performed using a soft drink. Furthermore, the determination of L-tyrosine was applied to supplements containing various kinds of amino acids. Each satisfactory relative recovery was obtained at 98 to 102%.

Selective Detection of Neurotransmitters by Fluorescence and Chemiluminescence Imaging

Energy Technology Data Exchange (ETDEWEB)

Ziqiang Wang; Edward S. Yeung

2001-08-06

In recent years, luminescence imaging has been widely employed in neurochemical analysis. It has a number of advantages for the study of neuronal and other biological cells: (1) a particular molecular species or cellular constituent can be selectively visualized in the presence of a large excess of other species in a heterogeneous environment; (2) low concentration detection limits can be achieved because of the inherent sensitivity associated with fluorescence and chemiluminescence; (3) low excitation intensities can be used so that long-term observation can be realized while the viability of the specimen is preserved; and (4) excellent spatial resolution can be obtained with the light microscope so subcellular compartments can be identified. With good sensitivity, temporal and spatial resolution, the flux of ions and molecules and the distribution and dynamics of intracellular species can be measured in real time with specific luminescence probes, substrates, or with native fluorescence. A noninvasive detection scheme based on glutamate dehydrogenase (GDH) enzymatic assay combined with microscopy was developed to measure the glutamate release in cultured cells from the central nervous system (CNS). The enzyme reaction is very specific and sensitive. The detection limit with CCD imaging is down to {micro}M levels of glutamate with reasonable response time. They also found that chemiluminescence associated with the ATP-dependent reaction between luciferase and luciferin can be used to image ATP at levels down to 10 nM in the millisecond time scale. Similar imaging experiments should be feasible in a broad spectrum of biological systems.

Combining Nitrilotriacetic Acid and Permeable Barriers for Enhanced Phytoextraction of Heavy Metals from Municipal Solid Waste Compost by and Reduced Metal Leaching.

Science.gov (United States)

Zhao, Shulan; Jia, Lina; Duo, Lian

2016-05-01

Phytoextraction has the potential to remove heavy metals from contaminated soil, and chelants can be used to improve the capabilities of phytoextraction. However, environmentally persistent chelants can cause metal leaching and groundwater pollution. A column experiment was conducted to evaluate the viability of biodegradable nitrilotriacetic acid (NTA) to increase the uptake of heavy metals (Cd, Cr, Ni, Pb, Cu, and Zn) by L. in municipal solid waste (MSW) compost and to evaluate the effect of two permeable barrier materials, bone meal and crab shell, on metal leaching. The application of NTA significantly increased the concentrations and uptake of heavy metals in . The enhancement was more pronounced at higher dosages of NTA. In the 15 mmol kg NTA treatment using a crab shell barrier, the Cr and Ni concentrations in the plant shoots increased by approximately 8- and 10-fold, respectively, relative to the control. However, the addition of NTA also caused significant heavy metal leaching from the MSW compost. Bone meal and crab shell barriers positioned between the compost and the subsoil were effective in preventing metal leaching down through the soil profile by the retention of metals in the barrier. The application of a biodegradable chelant and the use of permeable barriers is a viable form of enhanced phytoextraction to increase the removal of metals and to reduce possible leaching. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

The synthesis and chemiluminescence of a stable 1,2-dioxetane : an organic chemistry laboratory experiment

NARCIS (Netherlands)

Meijer, E.W.; Wynberg, H.

1982-01-01

An expt. for the synthesis of adamantylideneadamantane-1,2-dioxetane illustrating the concepts of the singlet O reaction and chemiluminescence, is described. All intermediates and products can be identified by undergraduate students using routine spectroscopic anal. [on SciFinder (R)

Ruthenium(II) tris(2,2'-bipyridine) chelate as a chemiluminophore in extrinsic lyoluminescences of aluminium and magnesium in aqueous solution

International Nuclear Information System (INIS)

Jiang Qinghong; Kotiranta, Miia; Langel, Kaarina; Suomi, Johanna; Hakansson, Markus; Spehar, Anna-Maria; Ala-Kleme, Timo; Eskola, Jarkko; Kulmala, Sakari

2005-01-01

Ruthenium(II) tris(2,2'-bipyridine) chelate shows chemiluminescence (CL) both during dissolution of metallic aluminium in alkaline conditions, and during dissolution of magnesium metal in acidic conditions. The presence of peroxodisulfate ions strongly enhances the CL. Magnesium system provides considerably better detectability of the present chelate giving linear calibration plot spanning over many orders of magnitude of concentration down to subnanomolar concentration levels. The possible primary species generated and luminescence mechanisms are shortly discussed

Luminol-dependent chemiluminescence in antibody-sensitized neutrophils stimulated with protein A-bearing staphylococci.

Science.gov (United States)

Nishihara, S; Seki, K; Ikigai, H; Masuda, S

1988-01-01

When mouse polymorphonuclear leukocytes (PMNs) sensitized with rabbit antibody to mouse Ehrlich ascites tumor cells were stimulated by Staphylococcus aureus Cowan I cells, a conspicuous luminol-dependent chemiluminescence was observed in the absence of opsonin. The profile of the chemiluminescence (CL) response evoked by staphylococcal cells from antibody-sensitized PMNs had two peaks. An initial peak, observed within 1 min after stimulation, was sharp and high and a second peak, observed about 5 min after stimulation, was low and extended. The CL response of antibody-sensitized PMNs stimulated by S. aureus Cowan I cells was dose-dependently blocked by preincubation with soluble SpA. Cells of a mutant derived from S. aureus Cowan I strain with trace amounts of cell-bound SpA failed to stimulate the antibody-sensitized PMNs to generate the CL response. The antibody-sensitized PMNs were found to phagocytize SpA-bearing S. aureus cells even in the absence of opsonic serum. These results suggest that the observation presented here might provide a useful tool for the investigation of CL response of PMNs.

Permanganate-bromide-silver nanoparticles as a new chemiluminescence system and its application to captopril determination.

Science.gov (United States)

Amjadi, Mohammad; Manzoori, Jamshid L; Hassanzadeh, Javad; Sorouraddin, Mohammad H

2013-10-15

A novel chemiluminescence (CL) system based on the oxidation of bromide by permanganate in sulfuric acid medium is introduced. The enhancing effect of silver nanoparticles (NPs), synthesized by chemical reduction method, on this reaction was studied. It was demonstrated that spherical silver nanoparticles with average size of 18 nm had a most remarkable catalytic effect on this reaction. CL emission wavelengths and UV-vis spectra were used to characterize the system and propose a possible mechanism. Furthermore, it was found that captopril inhibits the action of NPs and decreases the intensity of CL. Based on this phenomenon, a new CL method was developed for the determination of captopril in the 3.0 × 10(-10) to 1.0 × 10(-7) mol L(-1) concentration range with a detection limit (3s) of 0.12 nmol L(-1). The method was successfully applied to the determination of captopril in pharmaceutical formulations, human urine and serum samples. Copyright © 2013 Elsevier B.V. All rights reserved.

The s-Process Nucleosynthesis in Extremely Metal-Poor Stars as the Generating Mechanism of Carbon Enhanced Metal-Poor Stars

Science.gov (United States)

Suda, Takuma; Yamada, Shimako; Fujimoto, Masayuki Y.

The origin of carbon-enhanced metal-poor (CEMP) stars plays a key role in characterising the formation and evolution of the first stars and the Galaxy since the extremely-metal-poor (EMP) stars with [Fe/H] ≤ -2.5 share the common features of carbon enhancement in their surface chemical compositions. The origin of these stars is not yet established due to the controversy of the origin of CEMP stars without the enhancement of s-process element abundances, i.e., so called CEMP-no stars. In this paper, we elaborate the s-process nucleosynthesis in the EMP AGB stars and explore the origin of CEMP stars. We find that the efficiency of the s-process is controlled by O rather than Fe at [Fe/H] ≲ -2. We demonstrate that the relative abundances of Sr, Ba, Pb to C are explained in terms of the wind accretion from AGB stars in binary systems.

FDTD/TDSE study of surface-enhanced infrared absorption by metal nanoparticles.

Energy Technology Data Exchange (ETDEWEB)

Chang, S.-H.; Schatz, G. C.; Gray, S. K.; Chemistry; Northwestern Univ.; National Cheng-Kung Univ.

2006-01-01

We study surface-enhanced infrared absorption, including multiphoton processes, due to the excitation of surface plasmons on metal nanoparticles. The time-dependent Schroedinger equation and finite-difference time-domain method are self-consistently coupled to treat the problem.

Recent advances in metal oxide-based electrode architecture design for electrochemical energy storage

Energy Technology Data Exchange (ETDEWEB)

Jiang, Jian; Liu, Jinping; Huang, Xintang [Institute of Nanoscience and Nanotechnology, Department of Physics, Central China Normal University, Wuhan, Hubei (China); Li, Yuanyuan [School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan (China); Yuan, Changzhou; Lou, Xiong Wen [School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore (China)

2012-10-02

Metal oxide nanostructures are promising electrode materials for lithium-ion batteries and supercapacitors because of their high specific capacity/capacitance, typically 2-3 times higher than that of the carbon/graphite-based materials. However, their cycling stability and rate performance still can not meet the requirements of practical applications. It is therefore urgent to improve their overall device performance, which depends on not only the development of advanced electrode materials but also in a large part ''how to design superior electrode architectures''. In the article, we will review recent advances in strategies for advanced metal oxide-based hybrid nanostructure design, with the focus on the binder-free film/array electrodes. These binder-free electrodes, with the integration of unique merits of each component, can provide larger electrochemically active surface area, faster electron transport and superior ion diffusion, thus leading to substantially improved cycling and rate performance. Several recently emerged concepts of using ordered nanostructure arrays, synergetic core-shell structures, nanostructured current collectors, and flexible paper/textile electrodes will be highlighted, pointing out advantages and challenges where appropriate. Some future electrode design trends and directions are also discussed. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

A sensitive chemiluminescent immunoassay to detect Chromotrope FB (Chr FB) in foods.

Science.gov (United States)

Xu, Kun; Long, Hao; Xing, Rongge; Yin, Yongmei; Eremin, Sergei A; Meng, Meng; Xi, Rimo

2017-03-01

Chromotrope FB (Chr FB) is a synthetic azo dye permitted for use in foods and medicines. An acceptable daily intake (ADI) of Chr FB was 0-0.5mg/kg in China. In this study, we synthesized a Chr FB hapten with an amino group to prepare its artificial immunogen. Polyclonal antibodies obtained from New Zealand rabbits were applied to develop an indirect competitive chemiluminescent immunoassay (icCLIA) to detect Chr FB in foods. A horseradish peroxidase (HRP)-luminol-H 2 O 2 system was used to yield CL signal with p-iodophenol as an enhancement reagent. The method showed good specificity towards Chr FB and could detect as low as 0.02ngmL -1 Chr FB in buffer, 0.07ngg -1 in yoghurt candy, 0.07ngg -1 in vitamin drink and 0.13ngg -1 in bread. Compared with HPLC method, the proposed method is more sensitive by two orders of magnitude. The accuracy and precision of this method are acceptable and comparable with HPLC method. Therefore, the proposed method could be used for rapid screening of Chr FB in the mentioned foodstuffs. Copyright © 2016. Published by Elsevier B.V.

Inducing half-metallicity with enhanced stability in zigzag graphene nanoribbons via fluorine passivation

Energy Technology Data Exchange (ETDEWEB)

Jaiswal, Neeraj K., E-mail: neerajkjaiswal@gmail.com [Discipline of Physics, Indian Institute of Information Technology Design & Manufacturing, Jabalpur 482005 (India); Tyagi, Neha [Department of Applied Physics, Delhi Technological University, Delhi 110042 (India); Kumar, Amit [Discipline of Physics, Indian Institute of Information Technology Design & Manufacturing, Jabalpur 482005 (India); Srivastava, Pankaj [Nanomaterials Research Group, ABV-Indian Institute of Information Technology & Management, Gwalior 474015 (India)

2017-02-28

Highlights: • F passivated zigzag graphene nanoribbon (F-ZGNR) are more favorable than pristine ones. • External electric field induces half metallicity in F-ZGNR. • The observed half metallicity is independent of ribbon widths. • Enhanced stability makes F-ZGNR preferable over pristine ribbon. - Abstract: Half metals are the primary ingredients for the realization of novel spintronic devices. In the present work, by employing density functional theory based first-principles calculation, we predict half metallic behavior in fluorine passivated zigzag graphene nanoribbons (F-ZGNR). Four different structures have been investigated viz. one edge F passivated ZGNR (F-ZGNR-1), both edges F passivated ZGNR (F-ZGNR-2), F passivation on alternate sites in first configuration (alt-1) and F passivation on alternate sites in second configuration (alt-2). Interestingly, it is noticed that F passivation is analogous to H passivation (pristine), however, F-ZGNR are reckoned energetically more stable than pristine ones. An spin induced band gap is noticed for all F-ZGNR irrespective of their widths although its magnitude is slightly less than the pristine counterparts. With an external transverse electric field, ribbons undergo semiconducting to half metallic transformation. The observed half metallic character with enhanced stability present F-ZGNR as a better candidate than pristine ZGNR towards the realization of upcoming spintronic devices.

Comparison of Oral Contrast-Enhanced Transabdominal Ultrasound Imaging With Transverse Contrast-Enhanced Computed Tomography in Preoperative Tumor Staging of Advanced Gastric Carcinoma.

Science.gov (United States)

He, Xuemei; Sun, Jing; Huang, Xiaoling; Zeng, Chun; Ge, Yinggang; Zhang, Jun; Wu, Jingxian

2017-12-01

This study assessed the diagnostic performance of transabdominal oral contrast-enhanced ultrasound (US) imaging for preoperative tumor staging of advanced gastric carcinoma by comparing it with transverse contrast-enhanced computed tomography (CT). This retrospective study included 42 patients with advanced gastric cancer who underwent laparoscopy, radical surgery, or palliative surgery because of serious complications and had a body mass index of less than 25 kg/m 2 . A cereal-based oral contrast agent was used for transabdominal oral contrast-enhanced US. Retrospective analyses were conducted using preoperative tumor staging data acquired by either transabdominal oral contrast-enhanced US or transverse contrast-enhanced CT. Both contrast-enhanced US and contrast-enhanced CT examinations were reviewed by 2 experienced radiologists independently for preoperative tumor staging according to the seventh edition of the TNM classification. The accuracy, sensitivity, and specificity were calculated by comparing the results of contrast-enhanced US and contrast-enhanced CT with pathologic findings. The overall accuracies of the imaging modalities were compared by the McNemar test. No significant difference was noted in the overall accuracy of transabdominal oral contrast-enhanced US (86% [36 of 42]) and transverse contrast-enhanced CT (83% [35 of 42] P > .999). For stage T2 to T4 gastric cancer, the accuracies of transabdominal oral contrast-enhanced US were 88%, 86%, and 98%, respectively, and those of transverse contrast-enhanced CT were 93%, 83%, and 90%. The overall accuracy of transabdominal oral contrast-enhanced US was comparable with that of transverse contrast-enhanced CT for preoperative tumor staging of advanced gastric cancer. © 2017 by the American Institute of Ultrasound in Medicine.

Inhibition of chemiluminescence by carvedilol in the cell-free system, whole human blood and blood cells

Czech Academy of Sciences Publication Activity Database

Nosál, R.; Jančinová, V.; Číž, Milan; Drábiková, K.; Lojek, Antonín; Fábryová, V.

2005-01-01

Roč. 65, č. 1 (2005), s. 55-64 ISSN 0036-5513 Institutional research plan: CEZ:AV0Z50040507 Keywords : blood platelets * carvedilol * chemiluminescence Subject RIV: BO - Biophysics Impact factor: 0.946, year: 2005

Development of advanced spent fuel management process. The fabrication and oxidation behavior of simulated metallized spent fuel

Energy Technology Data Exchange (ETDEWEB)

Ro, Seung Gy; Shin, Y.J.; You, G.S.; Joo, J.S.; Min, D.K.; Chun, Y.B.; Lee, E.P.; Seo, H.S.; Ahn, S.B

1999-03-01

The simulated metallized spent fuel ingots were fabricated and evaluated the oxidation rates and the activation energies under several temperature conditions to develop an advanced spent fuel management process. It was also checked the alloying characteristics of the some elements with metal uranium. (Author). 3 refs., 1 tab., 36 figs.

Water cooled metal optics for the Advanced Light Source

International Nuclear Information System (INIS)

McKinney, W.R.; Irick, S.C.; Lunt, D.L.J.

1991-01-01

The program for providing water cooled metal optics for the Advanced Light Source at Berkeley is reviewed with respect to fabrication and metrology of the surfaces. Materials choices, surface figure and smoothness specifications, and metrology systems for measuring the plated metal surfaces are discussed. Results from prototype mirrors and grating blanks will be presented, which show exceptionally low microroughness and mid-period error. We will briefly describe out improved version of the Long Trace Profiler, and its importance to out metrology program. We have completely redesigned the mechanical, optical and computational parts of the profiler system with the cooperation of Peter Takacs of Brookhaven, Continental Optical, and Baker Manufacturing. Most important is that one of our profilers is in use at the vendor to allow testing during fabrication. Metrology from the first water cooled mirror for an ALS beamline is presented as an example. The preplating processing and grinding and polishing were done by Tucson Optical. We will show significantly better surface microroughness on electroless nickel, over large areas, than has been reported previously

Flow injection chemiluminescence determination of lercanidipine based on N-chlorosuccinimide-eosin Y post-chemiluminescence reaction.

Science.gov (United States)

Wang, Guowei; Zhao, Fang; Gao, Ying

2014-12-01

A novel post-chemiluminescence (PCL) reaction was discovered when lercanidipine was injected into the CL reaction mixture of N-chlorosuccinimide with alkaline eosin Y in the presence of cetyltrimethylammonium bromide (CTAB), where eosin Y was used as the CL reagent and CTAB as the surfactant. Based on this observation, a simple and highly sensitive PCL method combined with a flow injection (FI) technique was developed for the assay of lercanidipine. Under optimum conditions, the CL signal was linearly related to the concentration of lercanidipine in the range 7.0 × 10(-10) to 3.0 × 10(-6)  g/mL with a detection limit of 2.3 × 10(-10) g/mL (3σ). The relative standard deviation (RSD) was 2.1% for 1.0 × 10(-8) g/mL lercanidipine (n = 13). The proposed method had been applied to the estimation of lercanidipine in tablets and human serum samples with satisfactory results. The possible CL mechanism is also discussed briefly. Copyright © 2014 John Wiley & Sons, Ltd.

Determination of vitamin C in drugs using of an optimized novel TCPO–Amplex red–gold/silver alloy nanoparticles–H2O2 chemiluminescence method by the Box–Behnken design

International Nuclear Information System (INIS)

Chaichi, M.J.; Alijanpour, S.O.

2013-01-01

Response surface methodology (RSM), based on a Box–Behnken design (BBD) was used to optimize three of the most important operating variables (concentrations of TCPO, Amplex red and pH effect) at peroxyoxalate-chemiluminescence (PO-CL) system. For the first time Amplex red (AR) was introduced as a new fluorescent emitter for predicting the reaction mechanism of PO-CL by means of the fluorescence property of its oxidation product. In optimum conditions, it was found that Au/Ag alloy nanoparticles (NPs) could enhance the CL intensity and the method sensitivity toward the evaluation of trace amount of vitamin C. Based on the antioxidant property of vitamin C noticeably the CL signal of the bis-(2,4,6-trichlorophenyl)oxalate–AR–NPs–hydrogen peroxide–sodium salicylate system was quenched in a low basic medium. A simple, rapid and sensitive CL method for the determination of vitamin C has been developed. The results showed a linear relationship between vitamin C concentration and PO-CL intensity in the range of 0.082–82.7 μg/mL. Detection limit of 0.012 μg/mL and the relative standard deviation (RSD)<4% was obtained. - Highlights: ► The Box-Behnken design was used to optimize peroxyoxalate-chemiluminescence system. ► Amplex red is as new fluorescent emitters for peroxyoxalate chemiluminescence. ► It is introduce a method for determination of vitamin C. ► Detection limit of vitamin C was obtained about 0.012 μg/mL.

Enhanced metal recovery through oxidation in liquid and/or supercritical carbon dioxide

KAUST Repository

Blanco, Mario

2017-08-24

Process for enhanced metal recovery from, for example, metal-containing feedstock using liquid and/or supercritical fluid carbon dioxide and a source of oxidation. The oxidation agent can be free of complexing agent. The metal-containing feedstock can be a mineral such as a refractory mineral. The mineral can be an ore with high sulfide content or an ore rich in carbonaceous material. Waste can also be used as the metal-containing feedstock. The metal-containing feedstock can be used which is not subjected to ultrafine grinding. Relatively low temperatures and pressures can be used. The metal-containing feedstock can be fed into the reactor at a temperature below the critical temperature of the carbon dioxide, and an exotherm from the oxidation reaction can provide the supercritical temperature. The oxidant can be added to the reactor at a rate to maintain isothermal conditions in the reactor. Minimal amounts of water can be used as an extractive medium.

Combustion stratification study of partially premixed combustion using Fourier transform analysis of OH* chemiluminescence images

KAUST Repository

Izadi Najafabadi, Mohammad

2017-11-06

A relatively high level of stratification (qualitatively: lack of homogeneity) is one of the main advantages of partially premixed combustion over the homogeneous charge compression ignition concept. Stratification can smooth the heat release rate and improve the controllability of combustion. In order to compare stratification levels of different partially premixed combustion strategies or other combustion concepts, an objective and meaningful definition of “stratification level” is required. Such a definition is currently lacking; qualitative/quantitative definitions in the literature cannot properly distinguish various levels of stratification. The main purpose of this study is to objectively define combustion stratification (not to be confused with fuel stratification) based on high-speed OH* chemiluminescence imaging, which is assumed to provide spatial information regarding heat release. Stratification essentially being equivalent to spatial structure, we base our definition on two-dimensional Fourier transforms of photographs of OH* chemiluminescence. A light-duty optical diesel engine has been used to perform the OH* bandpass imaging on. Four experimental points are evaluated, with injection timings in the homogeneous regime as well as in the stratified partially premixed combustion regime. Two-dimensional Fourier transforms translate these chemiluminescence images into a range of spatial frequencies. The frequency information is used to define combustion stratification, using a novel normalization procedure. The results indicate that this new definition, based on Fourier analysis of OH* bandpass images, overcomes the drawbacks of previous definitions used in the literature and is a promising method to compare the level of combustion stratification between different experiments.

Label-free genotyping of cytochrome P450 2D6*10 using ligation-mediated strand displacement amplification with DNAzyme-based chemiluminescence detection.

Science.gov (United States)

Wang, Hong-Qi; Wu, Zhan; Zhang, Yan; Tang, Li-Juan; Yu, Ru-Qin; Jiang, Jian-Hui

2012-01-13

Genotyping of cytochrome P450 monooxygenase 2D6*10 (CYP2D6*10) plays an important role in pharmacogenomics, especially in clinical drug therapy of Asian populations. This work reported a novel label-free technique for genotyping of CYP2D6*10 based on ligation-mediated strand displacement amplification (SDA) with DNAzyme-based chemiluminescence detection. Discrimination of single-base mismatch is firstly accomplished using DNA ligase to generate a ligation product. The ligated product then initiates a SDA reaction to produce aptamer sequences against hemin, which can be probed by chemiluminescence detection. The proposed strategy is used for the assay of CYP2D6*10 target and the genomic DNA. The results reveal that the proposed technique displays chemiluminescence responses in linear correlation to the concentrations of DNA target within the range from 1 pM to 1 nM. A detection limit of 0.1 pM and a signal-to-background ratio of 57 are achieved. Besides such high sensitivity, the proposed CYP2D6*10 genotyping strategy also offers superb selectivity, great robustness, low cost and simplified operations due to its label-free, homogeneous, and chemiluminescence-based detection format. These advantages suggest this technique may hold considerable potential for clinical CYP2D6*10 genotyping and association studies. Copyright © 2011 Elsevier B.V. All rights reserved.

A simple and sensitive immunoassay for the determination of human chorionic gonadotropin by graphene-based chemiluminescence resonance energy transfer.

Science.gov (United States)

Lei, Jiuqian; Jing, Tao; Zhou, Tingting; Zhou, Yusun; Wu, Wei; Mei, Surong; Zhou, Yikai

2014-04-15

In this study, we report a strategy of chemiluminescence resonance energy transfer (CRET) using graphene as an efficient long-range energy acceptor. Magnetic nanoparticles were also used in CRET for simple magnetic separation and immobilization of horseradish peroxidase (HRP)-labeled anti-HCG antibody. In the design of CRET system, the sandwich-type immunocomplex was formed between human chorionic gonadotropin (HCG, antigen) and two different antibodies bridged the magnetic nanoparticles and graphene (acceptors), which led to the occurrence of CRET from chemiluminescence light source to graphene. After optimizing the experimental conditions, the quenching of chemiluminescence signal depended linearly on the concentration of HCG in the range of 0.1 mIU mL(-1)-10 mIU mL(-1) and the detection limit was 0.06 mIU mL(-1). The proposed method was successfully applied for the determination of HCG levels in saliva and serum samples, and the results were in good agreement with the plate ELISA with colorimetric detection. It could also be developed for detection of other antigen-antibody immune complexes by using the corresponding antigens and respective antibodies. © 2013 Published by Elsevier B.V.

Backside versus frontside advanced chemical analysis of high-k/metal gate stacks

Energy Technology Data Exchange (ETDEWEB)

Martinez, E., E-mail: eugenie.martinez@cea.fr [Univ Grenoble Alpes, F-38000 Grenoble (France); CEA, LETI, MINATEC Campus, F-38054 Grenoble (France); Saidi, B. [STMicroelectronics, 850 rue Jean Monnet, 38926 Rousset Cedex, Crolles (France); Veillerot, M. [Univ Grenoble Alpes, F-38000 Grenoble (France); CEA, LETI, MINATEC Campus, F-38054 Grenoble (France); Caubet, P. [STMicroelectronics, 850 rue Jean Monnet, 38926 Rousset Cedex, Crolles (France); Fabbri, J-M. [Univ Grenoble Alpes, F-38000 Grenoble (France); CEA, LETI, MINATEC Campus, F-38054 Grenoble (France); Piallat, F. [STMicroelectronics, 850 rue Jean Monnet, 38926 Rousset Cedex, Crolles (France); Gassilloud, R. [Univ Grenoble Alpes, F-38000 Grenoble (France); CEA, LETI, MINATEC Campus, F-38054 Grenoble (France); Schamm-Chardon, S. [CEMES-CNRS et Université de Toulouse, 29 rue Jeanne Marvig, 31055 Toulouse (France)

2015-08-15

Highlights: • The backside approach is a promising solution for advanced chemical characterization of future MOSFETs. • Frontside ToF-SIMS and Auger depth profiles are affected by cumulative mixing effects and thus not relevant for analyzing ultra-thin layers. • Higher in-depth resolution is possible in the backside approach for Auger and ToF-SIMS depth profiling. • Backside depth profiling allows revealing ultra-thin layers and elemental in-depth redistribution inside high-k/metal gate stacks. • Backside XPS allows preserving the full metal gate, thus enabling the analysis of real technological samples. - Abstract: Downscaling of transistors beyond the 14 nm technological node requires the implementation of new architectures and materials. Advanced characterization methods are needed to gain information about the chemical composition of buried layers and interfaces. An effective approach based on backside analysis is presented here. X-ray photoelectron spectroscopy, Auger depth profiling and time-of-flight secondary ions mass spectrometry are combined to investigate inter-diffusion phenomena. To highlight improvements related to the backside method, backside and frontside analyses are compared. Critical information regarding nitrogen, oxygen and aluminium redistribution inside the gate stacks is obtained only in the backside configuration.

Evaluation and Comparison of Chemiluminescence and UV Photometric Methods for Measuring Ozone Concentrations in Ambient Air

Science.gov (United States)

The current Federal Reference Method (FRM) for measuring concentrations of ozone in ambient air is based on the dry, gas-phase, chemiluminescence reaction between ethylene (C2H4) and any ozone (O3) that may be p...

Surface-enhanced Raman scattering on periodic metal nanotips with tunable sharpness

International Nuclear Information System (INIS)

Linn, Nicholas C; Sun, C-H; Arya, Ajay; Jiang Peng; Jiang Bin

2009-01-01

This paper reports on a scalable bottom-up technology for producing periodic gold nanotips with tunable sharpness as surface-enhanced Raman scattering (SERS) substrates. Inverted silicon pyramidal pits, which are templated from non-close-packed colloidal crystals prepared by a spin-coating technology, are used as structural templates to replicate arrays of polymer nanopyramids with nanoscale sharp tips. The deposition of a thin layer of gold on the polymer nanopyramids leads to the formation of SERS-active substrates with a high enhancement factor (up to 10 8 ). The thickness of the deposited metal determines the sharpness of the nanotips and the resulting Raman enhancement factor. Finite-element electromagnetic modeling shows that the nanotips can significantly enhance the local electromagnetic field and the sharpness of nanotips greatly affects the SERS enhancement.

Oxidized Metal Powders for Mechanical Shock and Crush Safety Enhancers; TOPICAL

International Nuclear Information System (INIS)

GARINO, TERRY J.

2002-01-01

The use of oxidized metal powders in mechanical shock or crush safety enhancers in nuclear weapons has been investigated. The functioning of these devices is based on the remarkable electrical behavior of compacts of certain oxidized metal powders when subjected to compressive stress. For example, the low voltage resistivity of a compact of oxidized tantalum powder was found to decrease by over six orders of magnitude during compaction between 1 MPa, where the thin, insulating oxide coatings on the particles are intact, to 10 MPa, where the oxide coatings have broken down along a chain of particles spanning the electrodes. In this work, the behavior of tantalum and aluminum powders was investigated. The low voltage resistivity during compaction of powders oxidized under various conditions was measured and compared. In addition, the resistivity at higher voltages and the dielectric breakdown strength during compaction were also measured. A key finding was that significant changes in the electrical properties persist after the removal of the stress so that a mechanical shock enhancer is feasible. This was verified by preliminary shock experiments. Finally, conceptual designs for both types of enhancers are presented

Advanced technologies for decomtamination and conversion of scrap metal

Energy Technology Data Exchange (ETDEWEB)

Valerie MacNair; Steve Sarten; Thomas Muth; Brajendra Mishra

1999-05-27

The Department of Energy (DOE) faces the task of decommissioning much of the vast US weapons complex. One challenge of this effort includes the disposition of large amounts of radioactively contaminated scrap metal (RSM) including but not limited to steel, nickel, copper, and aluminum. The decontamination and recycling of RSM has become a key element in the DOE's strategy for cleanup of contaminated sites and facilities. Recycling helps to offset the cost of decommissioning and saves valuable space in the waste disposal facilities. It also reduces the amount of environmental effects associated with mining new metals. Work on this project is geared toward finding decontamination and/or recycling alternatives for the RSM contained in the decommissioned gaseous diffusion plants including approximately 40,000 tons of nickel. The nickel is contaminated with Technetium-99, and is difficult to remove using traditional decontamination technologies. The project, titled ``Advanced Technologies for Decontamination and Conversion of Scrap Metal'' was proposed as a four phase project. Phase 1 and 2 are complete and Phase 3 will complete May 31, 1999. Stainless steel made from contaminated nickel barrier was successfully produced in Phase 1. An economic evaluation was performed and a market study of potential products from the recycled metal was completed. Inducto-slag refining, after extensive testing, was eliminated as an alternative to remove technetium contamination from nickel. Phase 2 included successful lab scale and pilot scale demonstrations of electrorefining to separate technetium from nickel. This effort included a survey of available technologies to detect technetium in volumetrically contaminated metals. A new process to make sanitary drums from RSM was developed and implemented. Phase 3 included a full scale demonstration of electrorefining, an evaluation of electro-refining alternatives including direct dissolution, melting of nickel into anodes, a

Conversion of just-continuous metallic films to large particulate substrates for metal-enhanced fluorescence

OpenAIRE

Aslan, Kadir; Malyn, Stuart N.; Zhang, Yongxia; Geddes, Chris D.

2008-01-01

We report the effects of thermally annealing, non-, just-, and thick continuous silver films for their potential applications in metal-enhanced fluorescence, a near-field concept which can alter the free-space absorption and emissive properties of close-proximity fluorophores (excited states). We have chosen to anneal a noncontinuous particulate film 5 nm thick and two thicker continuous films, 15 and 25 nm thick, respectively. Our results show that the annealing of the 25 nm film has little ...

Enhanced vasculotoxic metal excretion in post-myocardial infarction patients following a single edetate disodium-based infusion.

Science.gov (United States)

Arenas, Ivan A; Navas-Acien, Ana; Ergui, Ian; Lamas, Gervasio A

2017-10-01

Toxic metals have been associated with cardiovascular mortality and morbidity. We have hypothesized that enhanced excretion of vasculotoxic metals might explain the positive results of the Trial to Assess Chelation Therapy (TACT). The purpose of this study was to determine whether a single infusion of the edetate disodium- based infusion used in TACT led to enhanced excretion of toxic metals known to be associated with cardiovascular events. Twenty six patients (post-MI, age > 50 years, serum creatinine ≤ 2.0mg/dL) were enrolled in this open-label study. Urinary levels of 20 toxic metals normalized to urinary creatinine concentrations were measured at baseline in overnight urine collections, for 6h following a placebo infusion of 500mL normal saline and 1.2% dextrose, and for 6h following a 3g edetate disodium-based infusion. Self-reported metal exposure, smoking status, food frequency, occupational history, drinking water source, housing and hobbies were collected at baseline by a metal exposure questionnaire. The mean age was 65 years (range 51-81 years). All patients were male. 50% had diabetes mellitus and 58% were former smokers. Mean (SD) serum creatinine was 0.95 (0.31) mg/dL. Toxic metals were detected in the baseline urine of >80% of patients. After placebo infusion there were no significant changes in total urinary metal levels. After edetate infusion, total urinary metal level increased by 71% compared to baseline (1500 vs. 2580µg/g creatinine; P<0.0001). The effect of edetate was particularly large for lead (3835% increase) and cadmium (633% increase). Edetate disodium-based infusions markedly enhanced the urinary excretion of lead and cadmium, toxic metals with established epidemiologic evidence and mechanisms linking them to coronary and vascular events. Copyright © 2017 Elsevier Inc. All rights reserved.

Evolution of the Pediatric Advanced Life Support course: enhanced learning with a new debriefing tool and Web-based module for Pediatric Advanced Life Support instructors.

Science.gov (United States)

Cheng, Adam; Rodgers, David L; van der Jagt, Élise; Eppich, Walter; O'Donnell, John

2012-09-01

To describe the history of the Pediatric Advanced Life Support course and outline the new developments in instructor training that will impact the way debriefing is conducted during Pediatric Advanced Life Support courses. The Pediatric Advanced Life Support course, first released by the American Heart Association in 1988, has seen substantial growth and change over the past few decades. Over that time, Pediatric Advanced Life Support has become the standard for resuscitation training for pediatric healthcare providers in North America. The incorporation of high-fidelity simulation-based learning into the most recent version of Pediatric Advanced Life Support has helped to enhance the realism of scenarios and cases, but has also placed more emphasis on the importance of post scenario debriefing. We developed two new resources: an online debriefing module designed to introduce a new model of debriefing and a debriefing tool for real-time use during Pediatric Advanced Life Support courses, to enhance and standardize the quality of debriefing by Pediatric Advanced Life Support instructors. In this article, we review the history of Pediatric Advanced Life Support and Pediatric Advanced Life Support instructor training and discuss the development and implementation of the new debriefing module and debriefing tool for Pediatric Advanced Life Support instructors. The incorporation of the debriefing module and debriefing tool into the 2011 Pediatric Advanced Life Support instructor materials will help both new and existing Pediatric Advanced Life Support instructors develop and enhance their debriefing skills with the intention of improving the acquisition of knowledge and skills for Pediatric Advanced Life Support students.

Metal oxide nanoparticle mediated enhanced Raman scattering and its use in direct monitoring of interfacial chemical reactions.

Science.gov (United States)

Li, Li; Hutter, Tanya; Finnemore, Alexander S; Huang, Fu Min; Baumberg, Jeremy J; Elliott, Stephen R; Steiner, Ullrich; Mahajan, Sumeet

2012-08-08

Metal oxide nanoparticles (MONPs) have widespread usage across many disciplines, but monitoring molecular processes at their surfaces in situ has not been possible. Here we demonstrate that MONPs give highly enhanced (×10(4)) Raman scattering signals from molecules at the interface permitting direct monitoring of their reactions, when placed on top of flat metallic surfaces. Experiments with different metal oxide materials and molecules indicate that the enhancement is generic and operates at the single nanoparticle level. Simulations confirm that the amplification is principally electromagnetic and is a result of optical modulation of the underlying plasmonic metallic surface by MONPs, which act as scattering antennae and couple light into the confined region sandwiched by the underlying surface. Because of additional functionalities of metal oxides as magnetic, photoelectrochemical and catalytic materials, enhanced Raman scattering mediated by MONPs opens up significant opportunities in fundamental science, allowing direct tracking and understanding of application-specific transformations at such interfaces. We show a first example by monitoring the MONP-assisted photocatalytic decomposition reaction of an organic dye by individual nanoparticles.

Determination of thiram in natural waters using flow-injection with cerium(IV)-quinine chemiluminescence system.

Science.gov (United States)

Waseem, Amir; Yaqoob, Mohammad; Nabi, Abdul

2010-01-01

A simple and rapid flow-injection chemiluminescence method has been developed for the determination of dithiocarbamate fungicide thiram based on the chemiluminescence reaction of thiram with ceric sulfate and quinine in aqueous sulfuric acid. The present method allowed the determination of thiram in the concentration range of 7.5-2500 ng/mL and the detection limit (signal-to-noise ratio = 3) was 7.5 ng/mL with sample throughput of 120/h. The relative standard deviation was 2.5% for 10 replicate analyses of 500 ng/mL thiram. The effects of foreign species including various anions and cations present in water at environmentally relevant concentrations and some pesticides were also investigated. The proposed method was applied to determine thiram in spiked natural waters using octadecyl bonded phase silica (C(18)) cartridges for solid-phase extraction. The recoveries were in the range 99 +/- 1 to 104 +/- 1%. Copyright (c) 2009 John Wiley & Sons, Ltd.

Flow-injection chemiluminescent determination of estrogen benzoate using the tris(1,10-phenanthroline) ruthenium(II)-permanganate system.

Science.gov (United States)

Ma, Yan; Cao, Wei; Qiao, Shuang; Liu, Wenwen; Yang, Jinghe

2011-01-01

Chemiluminescence (CL) detection for the determination of estrogen benzoate, using the reaction of tris(1,10-phenanthroline)ruthenium(II)-Na(2)SO(3)-permanganate, is described. This method is based on the CL reaction of estrogen benzoate (EB) with acidic potassium permanganate and tris(1,10-phenanthroline)ruthenium(II). The CL intensity is greatly enhanced when Na(2)SO(3) is added. After optimization of the different experimental parameters, a calibration graph for estrogen benzoate is linear in the range 0.05-10 µg/mL. The 3 s limit of detection is 0.024 µg/mL and the relative standard deviation was 1.3% for 1.0 µg/mL estrogen benzoate (n = 11). This proposed method was successfully applied to commercial injection samples and emulsion cosmetics. The mechanism of CL reaction was also studied. Copyright © 2011 John Wiley & Sons, Ltd.

A magnetic particles-based chemiluminescence enzyme immunoassay for rapid detection of ovalbumin.

Science.gov (United States)

Feng, Xiao-Li; Ren, Hong-Lin; Li, Yan-Song; Hu, Pan; Zhou, Yu; Liu, Zeng-Shan; Yan, Dong-Ming; Hui, Qi; Liu, Dong; Lin, Chao; Liu, Nan-Nan; Liu, Yan-Yan; Lu, Shi-Ying

2014-08-15

Egg allergy is an important public health and safety concern, so quantification and administration of food or vaccines containing ovalbumin (OVA) are urgently needed. This study aimed to establish a rapid and sensitive magnetic particles-chemiluminescence enzyme immunoassay (MPs-CLEIA) for the determination of OVA. The proposed method was developed on the basis of a double antibodies sandwich immunoreaction and luminol-H2O2 chemiluminescence system. The MPs served as both the solid phase and separator, the anti-OVA MPs-coated polyclonal antibodies (pAbs) were used as capturing antibody, and the horseradish peroxidase (HRP)-labeled monoclonal antibody (mAb) was taken as detecting antibody. The parameters of the method were evaluated and optimized. The established MPs-CLEIA method had a linear range from 0.31 to 100ng/ml with a detection limit of 0.24ng/ml. The assays showed low reactivities and less than 5% of intraassay and interassay coefficients of variation (CVs), and the average recoveries were between 92 and 97%. Furthermore, the developed method was applied in real samples analysis successfully, and the correlation coefficient with the commercially available OVA kit was 0.9976. Moreover, it was more rapid and sensitive compared with the other methods for testing OVA. Copyright © 2014 Elsevier Inc. All rights reserved.

A metallic metal oxide (Ti5O9)-metal oxide (TiO2) nanocomposite as the heterojunction to enhance visible-light photocatalytic activity.

Science.gov (United States)

Li, L H; Deng, Z X; Xiao, J X; Yang, G W

2015-01-26

Coupling titanium dioxide (TiO2) with other semiconductors is a popular method to extend the optical response range of TiO2 and improve its photon quantum efficiency, as coupled semiconductors can increase the separation rate of photoinduced charge carriers in photocatalysts. Differing from normal semiconductors, metallic oxides have no energy gap separating occupied and unoccupied levels, but they can excite electrons between bands to create a high carrier mobility to facilitate kinetic charge separation. Here, we propose the first metallic metal oxide-metal oxide (Ti5O9-TiO2) nanocomposite as a heterojunction for enhancing the visible-light photocatalytic activity of TiO2 nanoparticles and we demonstrate that this hybridized TiO2-Ti5O9 nanostructure possesses an excellent visible-light photocatalytic performance in the process of photodegrading dyes. The TiO2-Ti5O9 nanocomposites are synthesized in one step using laser ablation in liquid under ambient conditions. The as-synthesized nanocomposites show strong visible-light absorption in the range of 300-800 nm and high visible-light photocatalytic activity in the oxidation of rhodamine B. They also exhibit excellent cycling stability in the photodegrading process. A working mechanism for the metallic metal oxide-metal oxide nanocomposite in the visible-light photocatalytic process is proposed based on first-principle calculations of Ti5O9. This study suggests that metallic metal oxides can be regarded as partners for metal oxide photocatalysts in the construction of heterojunctions to improve photocatalytic activity.

Ester oxidation on an aluminum surface using chemiluminescence

Science.gov (United States)

Jones, William R., Jr.; Meador, Michael A.; Morales, Wilfredo

1986-01-01

The oxidation characteristics of a pure ester (trimethyolpropane triheptanoate) were studied by using a chemiluminescence technique. Tests were run in a thin film microoxidation apparatus with an aluminum alloy catalyst. Conditions included a pure oxygen atmosphere and a temperature range of 176 to 206 C. Results indicated that oxidation of the ester (containing .001 M diphenylanthracene as an intensifier) was accompanied by emission of light. The maximum intensity of light emission was a function of the amount of ester, the concentration of intensifier, and the test temperature. The induction period, or the time to reach one-half of maximum intensity was inversely proportional to test temperature. Decreases in light emission at the later stages of a test were caused by depletion of the intensifier.

Metal hydrides based high energy density thermal battery

International Nuclear Information System (INIS)

Fang, Zhigang Zak; Zhou, Chengshang; Fan, Peng; Udell, Kent S.; Bowman, Robert C.; Vajo, John J.; Purewal, Justin J.; Kekelia, Bidzina

2015-01-01

Highlights: • The principle of the thermal battery using advanced metal hydrides was demonstrated. • The thermal battery used MgH 2 and TiMnV as a working pair. • High energy density can be achieved by the use of MgH 2 to store thermal energy. - Abstract: A concept of thermal battery based on advanced metal hydrides was studied for heating and cooling of cabins in electric vehicles. The system utilized a pair of thermodynamically matched metal hydrides as energy storage media. The pair of hydrides that was identified and developed was: (1) catalyzed MgH 2 as the high temperature hydride material, due to its high energy density and enhanced kinetics; and (2) TiV 0.62 Mn 1.5 alloy as the matching low temperature hydride. Further, a proof-of-concept prototype was built and tested, demonstrating the potential of the system as HVAC for transportation vehicles

Determination of vitamin C in drugs using of an optimized novel TCPO-Amplex red-gold/silver alloy nanoparticles-H{sub 2}O{sub 2} chemiluminescence method by the Box-Behnken design

Energy Technology Data Exchange (ETDEWEB)

Chaichi, M.J., E-mail: jchaichi@yahoo.com [Faculty of Chemistry, University of Mazandaran, Babolsar (Iran, Islamic Republic of); Alijanpour, S.O. [Faculty of Chemistry, University of Mazandaran, Babolsar (Iran, Islamic Republic of)

2013-02-15

Response surface methodology (RSM), based on a Box-Behnken design (BBD) was used to optimize three of the most important operating variables (concentrations of TCPO, Amplex red and pH effect) at peroxyoxalate-chemiluminescence (PO-CL) system. For the first time Amplex red (AR) was introduced as a new fluorescent emitter for predicting the reaction mechanism of PO-CL by means of the fluorescence property of its oxidation product. In optimum conditions, it was found that Au/Ag alloy nanoparticles (NPs) could enhance the CL intensity and the method sensitivity toward the evaluation of trace amount of vitamin C. Based on the antioxidant property of vitamin C noticeably the CL signal of the bis-(2,4,6-trichlorophenyl)oxalate-AR-NPs-hydrogen peroxide-sodium salicylate system was quenched in a low basic medium. A simple, rapid and sensitive CL method for the determination of vitamin C has been developed. The results showed a linear relationship between vitamin C concentration and PO-CL intensity in the range of 0.082-82.7 {mu}g/mL. Detection limit of 0.012 {mu}g/mL and the relative standard deviation (RSD)<4% was obtained. - Highlights: Black-Right-Pointing-Pointer The Box-Behnken design was used to optimize peroxyoxalate-chemiluminescence system. Black-Right-Pointing-Pointer Amplex red is as new fluorescent emitters for peroxyoxalate chemiluminescence. Black-Right-Pointing-Pointer It is introduce a method for determination of vitamin C. Black-Right-Pointing-Pointer Detection limit of vitamin C was obtained about 0.012 {mu}g/mL.

Metal Nanoparticles and Carbon-Based Nanostructures as Advanced Materials for Cathode Application in Dye-Sensitized Solar Cells

Directory of Open Access Journals (Sweden)

Pietro Calandra

2010-01-01

Full Text Available We review the most advanced methods for the fabrication of cathodes for dye-sensitized solar cells employing nanostructured materials. The attention is focused on metal nanoparticles and nanostructured carbon, among which nanotubes and graphene, whose good catalytic properties make them ideal for the development of counter electrode substrates, transparent conducting oxide, and advanced catalyst materials.

TREATMENT OF METAL-LADEN HAZARDOUS WASTES WITH ADVANCED CLEAN COAL TECHNOLOGY BY-PRODUCTS

Energy Technology Data Exchange (ETDEWEB)

James T. Cobb, Jr.

2003-09-12

Metal-laden wastes can be stabilized and solidified using advanced clean coal technology by-products (CCTBs)--fluid bed combustor ash and spray drier solids. These utility-generated treatment chemicals are available for purchase through brokers, and commercial applications of this process are being practiced by treaters of metal-laden hazardous waste. A complex of regulations governs this industry, and sensitivities to this complex has discouraged public documentation of treatment of metal-laden hazardous wastes with CCTBs. This report provides a comprehensive public documentation of laboratory studies that show the efficacy of the stabilization and solidification of metal-laden hazardous wastes--such as lead-contaminated soils and sandblast residues--through treatment with CCTBs. It then describes the extensive efforts that were made to obtain the permits allowing a commercial hazardous waste treater to utilize CCTBs as treatment chemicals and to install the equipment required to do so. It concludes with the effect of this lengthy process on the ability of the treatment company to realize the practical, physical outcome of this effort, leading to premature termination of the project.

An advanced field experimental design to assess plant tolerance to heavy metal pollution

Science.gov (United States)

Łopata, Barbara; Szarek-Łukaszewska, Grażyna; Babst-Kostecka, Alicja

2016-04-01

Only a limited number of vascular plant species can survive and reproduce in toxic metalliferous environments. Among these species, pseudometallophytes are particularly interesting, as their metallicolous (M) populations on metalliferous soils and non-metallicolous (NM) populations on non-metalliferous soils show very pronounced ecological differences. Pseudometallophytes thus provide excellent opportunities for multidisciplinary research to improve phytoremediation and phytomining. Numerous methods have been developed to investigate plant adaptation to metal pollution, the majority of which has been conducted under controlled laboratory conditions. Although these efforts have significantly advanced our understanding of mechanisms underlying metal tolerance in plants, populations must be reciprocally transplanted to clearly identify natural selection. Only then is it possible to test, whether the fitness of native plants is higher than that of nonnative populations and thereby prove local adaptation. Here, we present an enhanced field experimental design aimed at verification of local adaptation to habitats with different levels of heavy metal soil contamination. At two M and two NM sites, we established a total of 12 plots (4 sites x 3 plots each), removed the existing local vegetation, and collected soil samples for chemical analyses (5 samples per plot). Plant collection (N= 480) from all four selected populations was established under laboratory conditions prior to the transplant experiment. Genotypes were randomly distributed within each plot (240 x 270 cm) and planted along a regulary spaced grid (30x30cm cell size) in spring 2015. Measurements will start in spring 2016, by which time plants are expected to have acclimatized to the local conditions. For the two subsiquent years, growth, survival, fitness, life cycle and herbivory consumption will be monitored for each transplant. On a weekly basis, we will record: 1) pictures of each transplant to determine

Design, fabrication, and characterization of metallic nanostructures for surface-enhanced Raman spectroscopy and plasmonic applications

Science.gov (United States)

Hao, Qingzhen

Metal/dielectric nanostructures have the ability to sustain coherent electron oscillations known as surface plasmons. Due to their capability of localizing and guiding light in sub-wavelength metal nanostructures beyond diffraction limits, surface plasmon-based photonics, or “plasmonics” has opened new physical phenomena and lead to novel applications in metamaterials, optoelectronics, surface enhanced spectroscopy and biological sensing. This dissertation centers on design, fabrication, characterization of metallic nanostructures and their applications in surface-enhanced Raman spectroscopy (SERS) and actively tunable plasmonics. Metal-dielectric nanostructures are the building blocks for photonic metamaterials. One valuable design guideline for metamaterials is the Babinet’s principle, which governs the optical properties of complementary nanostructures. However, most complementary metamaterials are designed for the far infrared region or beyond, where the optical absorption of metal is small. We have developed a novel dual fabrication method, capable of simultaneously producing optically thin complementary structures. From experimental measurements and theoretical simulations, we showed that Babinet’s principle qualitatively holds in the visible region for the optically thin complements. The complementary structure is also a good platform to study subtle differences between nanoparticles and nanoholes in SERS (a surface sensitive technique, which can enhance the conventional Raman cross-section by 106˜108 fold, thus very useful for highly sensitive biochemical sensing). Through experimental measurement and theoretical analysis, we showed that the SERS enhancement spectrum (plot of SERS enhancement versus excitation wavelengths), dominated by local near-field, for nanoholes closely follows their far-field optical transmission spectrum. However, the enhancement spectrum for nanoparticles red-shifts significantly from their far-field optical extinction

Recent advances in transition-metal dichalcogenides based electrochemical biosensors: A review.

Science.gov (United States)

Wang, Yi-Han; Huang, Ke-Jing; Wu, Xu

2017-11-15

Layered transition metal dichalcogenides (TMDCs) comprise a category of two-dimensional (2D) materials that offer exciting properties, including large surface area, metallic and semi-conducting electrical capabilities, and intercalatable morphologies. Biosensors employ biological molecules to recognize the target and utilize output elements which can translate the biorecognition event into electrical, optical or mass-sensitive signals to determine the quantities of the target. TMDCs nanomaterials have been widely applied in various electrochemical biosensors with high sensitivity and selectivity. The marriage of TMDCs and electrochemical biosensors has created many productive sensing strategies for applications in the areas of clinical diagnosis, environmental monitoring and food safety. In recent years, an increasing number of TMDCs-based electrochemical biosensors are reported, suggesting TMDCs offers new possibilities of improving the performance of electrochemical biosensors. This review summarizes recent advances in electrochemical biosensors based on TMDCs for detection of various inorganic and organic analytes in the last five years, including glucose, proteins, DNA, heavy metal, etc. In addition, we also point out the challenges and future perspectives related to the material design and development of TMDCs-based electrochemical biosensors. Copyright © 2017 Elsevier B.V. All rights reserved.

Microscopic model of the THz field enhancement in a metal nanoslit

DEFF Research Database (Denmark)

Novitsky, Andrey; Zalkovskij, Maksim; Malureanu, Radu

2011-01-01

We discuss the strong THz-field enhancement effect in a metal slit of dozens of nanometers sizes reported recently. Proposed simple microscopic model considers electric charges induced at the edges of the slit by a polarized incident wave. These charges contribute then to the field in the slit...

A SEARCH FOR UNRECOGNIZED CARBON-ENHANCED METAL-POOR STARS IN THE GALAXY

International Nuclear Information System (INIS)

Placco, Vinicius M.; Rossi, Silvia; Kennedy, Catherine R.; Beers, Timothy C.; Lee, Young Sun; Christlieb, Norbert; Sivarani, Thirupathi; Reimers, Dieter; Wisotzki, Lutz

2010-01-01

We have developed a new procedure to search for carbon-enhanced metal-poor (CEMP) stars from the Hamburg/ESO (HES) prism-survey plates. This method employs an extended line index for the CH G band, which we demonstrate to have superior performance when compared to the narrower G-band index formerly employed to estimate G-band strengths for these spectra. Although CEMP stars have been found previously among candidate metal-poor stars selected from the HES, the selection on metallicity undersamples the population of intermediate-metallicity CEMP stars (-2.5 ≤ [Fe/H] ≤ -1.0); such stars are of importance for constraining the onset of the s-process in metal-deficient asymptotic giant branch stars (thought to be associated with the origin of carbon for roughly 80% of CEMP stars). The new candidates also include substantial numbers of warmer carbon-enhanced stars, which were missed in previous HES searches for carbon stars due to selection criteria that emphasized cooler stars. A first subsample, biased toward brighter stars (B< 15.5), has been extracted from the scanned HES plates. After visual inspection (to eliminate spectra compromised by plate defects, overlapping spectra, etc., and to carry out rough spectral classifications), a list of 669 previously unidentified candidate CEMP stars was compiled. Follow-up spectroscopy for a pilot sample of 132 candidates was obtained with the Goodman spectrograph on the SOAR 4.1 m telescope. Our results show that most of the observed stars lie in the targeted metallicity range, and possess prominent carbon absorption features at 4300 A. The success rate for the identification of new CEMP stars is 43% (13 out of 30) for [Fe/H] < -2.0. For stars with [Fe/H] < -2.5, the ratio increases to 80% (four out of five objects), including one star with [Fe/H] < -3.0.

Enhancement of surface integrity of titanium alloy with copper by means of laser metal deposition process

CSIR Research Space (South Africa)

Erinosho, MF

2016-04-01

Full Text Available The laser metal deposition process possesses the combination of metallic powder and laser beam respectively. However, these combinations create an adhesive bonding that permanently solidifies the laser-enhanced-deposited powders. Titanium alloys (Ti...

Metal-organic frameworks at interfaces of hybrid perovskite solar cells for enhanced photovoltaic properties.

Science.gov (United States)

Shen, Deli; Pang, Aiying; Li, Yafeng; Dou, Jie; Wei, Mingdeng

2018-01-31

In this study, metal-organic frameworks, as an interfacial layer, were introduced into perovskite solar cells (PSCs) for the first time. An interface modified with the metal-organic framework ZIF-8 efficiently enhanced perovskite crystallinity and grain sizes, and the photovoltaic performance of the PSCs was significantly improved, resulting in a maximum PCE of 16.99%.

EDDS and EDTA-enhanced phytoextraction of metals from artificially contaminated soil and residual effects of chelant compounds

Energy Technology Data Exchange (ETDEWEB)

Luo Chunling [Department of Civil and Structural Engineering, Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong (China); Shen Zhenguo [Department of Civil and Structural Engineering, Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong (China); College of Life Sciences, Nanjing Agricultural University, Nanjing 210095 (China); Lou Laiqing [College of Life Sciences, Nanjing Agricultural University, Nanjing 210095 (China); Li Xiangdong [Department of Civil and Structural Engineering, Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong (China)]. E-mail: cexdli@polyu.edu.hk

2006-12-15

The potential of 18 different plants to be used in the chemically enhanced phytoextraction of Cu, Pb, Zn and Cd was assessed using pot experiments. Chrysanthemum coronarium L. was the species most sensitive to the application of EDTA, and had the highest enhancement of Cu and Pb concentrations in its shoots. Compared with EDTA, EDDS was more effective in enhancing the concentration of Cu in the shoots of Chrysanthemum coronarium L. and Zea mays L. grown on multi-metal contaminated soils. The EDTA-treated soil still had a significant ability to enhance the concentrations of Cu and Pb in the shoots of Zea mays L. six months after the chelant treatment. However, the EDDS-treated soil did not have any effect in enhancing the concentrations of metals in the shoots of Zea mays L. in the second crop test. The results may indicate that EDDS biodegrades more rapidly than EDTA in soil and is better in limiting potential metal leaching. - Chrysanthemum coronarium L. was the most sensitive species to the application of chelants, and EDDS biodegrades much more rapidly than EDTA in soil.

EDDS and EDTA-enhanced phytoextraction of metals from artificially contaminated soil and residual effects of chelant compounds

International Nuclear Information System (INIS)

Luo Chunling; Shen Zhenguo; Lou Laiqing; Li Xiangdong

2006-01-01

The potential of 18 different plants to be used in the chemically enhanced phytoextraction of Cu, Pb, Zn and Cd was assessed using pot experiments. Chrysanthemum coronarium L. was the species most sensitive to the application of EDTA, and had the highest enhancement of Cu and Pb concentrations in its shoots. Compared with EDTA, EDDS was more effective in enhancing the concentration of Cu in the shoots of Chrysanthemum coronarium L. and Zea mays L. grown on multi-metal contaminated soils. The EDTA-treated soil still had a significant ability to enhance the concentrations of Cu and Pb in the shoots of Zea mays L. six months after the chelant treatment. However, the EDDS-treated soil did not have any effect in enhancing the concentrations of metals in the shoots of Zea mays L. in the second crop test. The results may indicate that EDDS biodegrades more rapidly than EDTA in soil and is better in limiting potential metal leaching. - Chrysanthemum coronarium L. was the most sensitive species to the application of chelants, and EDDS biodegrades much more rapidly than EDTA in soil

Sensitive chemiluminescence immunoassay for staphylococcal enterotoxin C1 based on the use of dye-encapsulated mesoporous silica nanoparticles

International Nuclear Information System (INIS)

Tao, Liang; Zhang, Chunmei; Sun, Yuanjie; Jin, Boquan; Yang, Kun; Li, Xiaohua; Zhang, Zhujun; Zhang, Jinpeng; Yan, Kuocheng

2016-01-01

A chemiluminescent immunoassay for the staphylococcal enterotoxin C1 (SEC1) based on the use of dye-encapsulated mesoporous silica nanoparticles (m-SiNPs) as a label is described. The dyes are retained in the m-SiNPs via strong hydrophobic interactions. The assay comprises the following steps: (a) Microplates coated with antibody against SEC1 are filled with sample upon which the SEC antigen will be bound to the surface; (b) following a washing step, secondary antibody linked to m-SiNPs (that were covalently labeled with rhodamine 6G and fluorescein) were added to form the sandwich complex; (c) after another washing step, bis(2,4,6-trichlorophenyl) oxalate, H_2O_2 and imidazole are added to generate chemiluminescence whose intensity is proportional to the number of m-SiNPs and thus to the number of antigen (SEC) molecules. It is found that the use of functionalized m-SiNPs strongly amplifies the signal. Enterotoxin SEC1 can be detected by this method in the 0.025 to 2 ng⋅mL"-"1 concentration range, the detection limit is 19 pg⋅mL"-"1 (at 3σ), and the relative standard deviation (for 11 parallel measurements at a 1 ng⋅mL"-"1 level) is 4.6 %. The use of an automated chemiluminescence analyzer further improves detection. (author)

Novel strategy for the preparation of graphene-encapsulated mesoporous metal oxides with enhanced lithium storage

International Nuclear Information System (INIS)

Lin, Rong; Yue, Wenbo; Niu, Fangzhou; Ma, Jie

2016-01-01

As potential anode materials for lithium-ion batteries, mesoporous metal oxides show high reversible capacities but relatively poor cycle stability due to the structural collapse during cycles. Graphene-encapsulated mesoporous metal oxides may increase the electronic conductivity of the composite as well as stabilize the mesostructure of metal oxides, thereby enhancing the electrochemical performance of mesoporous metal oxides. Herein we describe a novel strategy for the preparation of graphene-encapsulated mesoporous metal oxides (SnO_2, Mn_3O_4), which exhibit superior electrochemical performance compared to pure mesoporous metal oxides. Moreover, some mesoporous metal oxides may be further reduced to low-valence metal oxides when calcined in presence of graphene. Mesoporous metal oxides with high isoelectric points are not essential for this synthesis method since metal oxides are connected with graphene through mesoporous silica template, thus expanding the types of graphene-encapsulated mesoporous metal oxides.

Comparative sodium void effects for different advanced liquid metal reactor fuel and core designs

International Nuclear Information System (INIS)

Dobbin, K.D.; Kessler, S.F.; Nelson, J.V.; Gedeon, S.R.; Omberg, R.P.

1991-01-01

An analysis of metal-, oxide-, and nitride-fueled advanced liquid metal reactor cores was performed to investigate the calculated differences in sodium void reactivity, and to determine the relationship between sodium void reactivity and burnup reactivity swing using the three fuel types. The results of this analysis indicate that nitride fuel has the least positive sodium void reactivity for any given burnup reactivity swing. Thus, it appears that a good design compromise between transient overpower and loss of flow response is obtained using nitride fuel. Additional studies were made to understand these and other nitride advantages. (author)

Antimicrobial resistance challenged with metal-based antimicrobial macromolecules.

Science.gov (United States)

Abd-El-Aziz, Alaa S; Agatemor, Christian; Etkin, Nola

2017-02-01

Antimicrobial resistance threatens the achievements of science and medicine, as it deactivates conventional antimicrobial therapeutics. Scientists respond to the threat by developing new antimicrobial platforms to prevent and treat infections from these resistant strains. Metal-based antimicrobial macromolecules are emerging as an alternative to conventional platforms because they combine multiple mechanisms of action into one platform due to the distinctive properties of metals. For example, metals interact with intracellular proteins and enzymes, and catalyse various intracellular processes. The macromolecular architecture offers a means to enhance antimicrobial activity since several antimicrobial moieties can be conjugated to the scaffold. Further, these macromolecules can be fabricated into antimicrobial materials for contact-killing medical implants, fabrics, and devices. As volatilization or leaching out of the antimicrobial moieties from the macromolecular scaffold is reduced, these medical implants, fabrics, and devices can retain their antimicrobial activity over an extended period. Recent advances demonstrate the potential of metal-based antimicrobial macromolecules as effective platforms that prevent and treat infections from resistant strains. In this review these advances are thoroughly discussed within the context of examples of metal-based antimicrobial macromolecules, their mechanisms of action and biocompatibility. Copyright © 2016 Elsevier Ltd. All rights reserved.

Phagocytic and chemiluminescent responses of mouse peritoneal macrophages to living and killed Salmonella typhimurium and other bacteria

International Nuclear Information System (INIS)

Tomita, T.; Blumenstock, E.; Kanegasaki, S.

1981-01-01

In the presence of luminol, resident as well as thioglycolate-induced and immunized macrophages emitted chemiluminescence more efficiently when the cells were exposed to living Salmonella typhimurium than when they were exposed to the same bacterium killed by ultraviolet light or heat. This phenomenon was observed whether or not the bacterium was opsonized. The different response to living and killed bacteria was also found with Escherichia coli, Pseudomonas aeruginosa, Proteus morganii, and Enterobacter aerogenes, but not with Shigella sonnei, Klebsiella pneumoniae, and Propionibacterium acnes. The results suggest that macrophages respond better to living, motile bacteria than to nonmotile or killed bacteria. The experimental results obtained with motility mutants of S. typhimurium, E. coli, and P. aeruginosa confirm that macrophages exposed to the motile bacteria emit chemiluminescence more efficiently and ingest the motile bacteria at a much faster rate than the nonmotile bacteria

Novelties in design and construction of the advanced reactors

International Nuclear Information System (INIS)

Acosta Ezcurra, T.; Garcia Rodriguez, B.M.

1996-01-01

The advanced pressurized water reactors (APWR), advanced boiling water reactors (ABWR), advanced liquid metal reactors (ALMR), and modular high temperature gas-cooled reactors (MHTGR), as well as heavy water reactors (AHWR), are analyzed taking into account those characteristics which make them less complex, but safer than their current homologous ones. This fact simplifies their construction which reduces completion periods and costs, increasing safety and protection of the plants. It is demonstrated how the accumulated operational experience allows to find more standardized designs with some enhancement in the material and component technology and thus achieve also a better use of computerized systems

A distance-dependent metal-enhanced fluorescence sensing platform based on molecular beacon design.

Science.gov (United States)

Zhou, Zhenpeng; Huang, Hongduan; Chen, Yang; Liu, Feng; Huang, Cheng Zhi; Li, Na

2014-02-15

A new metal-enhanced fluorescence (MEF) based platform was developed on the basis of distance-dependent fluorescence quenching-enhancement effect, which combined the easiness of Ag-thiol chemistry with the MEF property of noble-metal structures as well as the molecular beacon design. For the given sized AgNPs, the fluorescence enhancement factor was found to increase with a d(6) dependency in agreement with fluorescence resonance energy transfer mechanism at shorter distance and decrease with a d(-3) dependency in agreement with plasmonic enhancement mechanism at longer distance between the fluorophore and the AgNP surface. As a proof of concept, the platform was demonstrated by a sensitive detection of mercuric ions, using thymine-containing molecular beacon to tune silver nanoparticle (AgNP)-enhanced fluorescence. Mercuric ions were detected via formation of a thymine-mercuric-thymine structure to open the hairpin, facilitating fluorescence recovery and AgNP enhancement to yield a limit of detection of 1 nM, which is well below the U.S. Environmental Protection Agency regulation of the Maximum Contaminant Level Goal (10nM) in drinking water. Since the AgNP functioned as not only a quencher to reduce the reagent blank signal but also an enhancement substrate to increase fluorescence of the open hairpin when target mercuric ions were present, the quenching-enhancement strategy can greatly improve the detection sensitivity and can in principle be a universal approach for various targets when combined with molecular beacon design. © 2013 Elsevier B.V. All rights reserved.

Advance reactor and fuel-cycle systems--potentials and limitations for United States utilities

International Nuclear Information System (INIS)

Zebroski, E.L.; Williams, R.F.

1979-01-01

This paper reviews the potential benefits and limitations of advance reactor and fuel-cycle systems for United States utilities. The results of the review of advanced technologies show that for the near and midterm, the only advance reactor and fuel-cycle system with significant potential for United States utilities is the current LWR, and evolutionary, not revolutionary, enhancements. For the long term, the liquid-metal breeder reactor continues to be the most promising advance nuclear option. The major factors leading to this conclusion are summarized

Enhanced pycnonuclear reactions in ultrahigh-pressure metals

International Nuclear Information System (INIS)

Ichimaru, Setsuo; Kitamura, Hikaru

1995-01-01

By combining the concepts of pycnonuclear reactions at low temperatures and their enhancement due to strong internuclear Coulomb correlations, we predict the possibilities of a novel scheme for fusion in ultrahigh-pressure liquid-metallic hydrogen near the freezing conditions, for the reactions 2 H(p,γ) 3 He, 3 H(d,n) 4 He, and 7 Li(p,α) 4 He. Time evolution is followed for p-d reaction after a pulsed compression with 1 kJ input and the initial conditions of mass density ≅ 20 g/cm 3 , temperature ≅ 1400 K, pressure ≅ 490 Mbar, and radius ≅ 0.017 cm; an energy yield of 33 kJ in 0.03 fs is thus predicted. (author)

Electrogenerated Chemiluminescence Behavior of Au nanoparticles-hybridized Pb (II) metal-organic framework and its application in selective sensing hexavalent chromium.

Science.gov (United States)

Ma, Hongmin; Li, Xiaojian; Yan, Tao; Li, Yan; Liu, Haiyang; Zhang, Yong; Wu, Dan; Du, Bin; Wei, Qin

2016-02-23

In this work, a novel electrochemiluminescence (ECL) sensor based on Au nanoparticles-hybridized Pb (II)-β-cyclodextrin (Pb-β-CD) metal-organic framework for detecting hexavalent chromium (Cr(VI)) was developed. Pb-β-CD shows excellent ECL behavior and unexpected reducing ability towards Au ions. Au nanoparticles could massively form on the surface of Pb-β-CD (Au@Pb-β-CD) without use of any additional reducing agent. In the presence of coreactant K2S2O8, the ECL emission of Pb-β-CD was enhanced by the formation of Au nanoparticles. Cr(VI) can collisionally quench the ECL behavior of Au@Pb-β-CD/S2O8(2-) system and the detection mechanism was investigated. This ECL sensor is found to have a linear response in the range of 0.01-100 μM and a low detection limit of 3.43 nM (S/N = 3) under the optimal conditions. These results suggest that metal-organic framework Au@Pb-β-CD has great potential in extending the application in the ECL field as an efficient luminophore.

Metal hydrides based high energy density thermal battery

Energy Technology Data Exchange (ETDEWEB)

Fang, Zhigang Zak, E-mail: zak.fang@utah.edu [Department of Metallurgical Engineering, The University of Utah, 135 South 1460 East, Room 412, Salt Lake City, UT 84112-0114 (United States); Zhou, Chengshang; Fan, Peng [Department of Metallurgical Engineering, The University of Utah, 135 South 1460 East, Room 412, Salt Lake City, UT 84112-0114 (United States); Udell, Kent S. [Department of Metallurgical Engineering, The University of Utah, 50 S. Central Campus Dr., Room 2110, Salt Lake City, UT 84112-0114 (United States); Bowman, Robert C. [Department of Metallurgical Engineering, The University of Utah, 135 South 1460 East, Room 412, Salt Lake City, UT 84112-0114 (United States); Vajo, John J.; Purewal, Justin J. [HRL Laboratories, LLC, 3011 Malibu Canyon Road, Malibu, CA 90265 (United States); Kekelia, Bidzina [Department of Metallurgical Engineering, The University of Utah, 50 S. Central Campus Dr., Room 2110, Salt Lake City, UT 84112-0114 (United States)

2015-10-05

Highlights: • The principle of the thermal battery using advanced metal hydrides was demonstrated. • The thermal battery used MgH{sub 2} and TiMnV as a working pair. • High energy density can be achieved by the use of MgH{sub 2} to store thermal energy. - Abstract: A concept of thermal battery based on advanced metal hydrides was studied for heating and cooling of cabins in electric vehicles. The system utilized a pair of thermodynamically matched metal hydrides as energy storage media. The pair of hydrides that was identified and developed was: (1) catalyzed MgH{sub 2} as the high temperature hydride material, due to its high energy density and enhanced kinetics; and (2) TiV{sub 0.62}Mn{sub 1.5} alloy as the matching low temperature hydride. Further, a proof-of-concept prototype was built and tested, demonstrating the potential of the system as HVAC for transportation vehicles.

Application of UV-Vis spectrophotometric and chemiluminescent methods for the evaluation of the antioxidant action of curcumin

Czech Academy of Sciences Publication Activity Database

Stanchev, Stancho; Pencheva, I.; Konstantinov, S.; Obreshkova, D.; Hadjimitova, V.

2012-01-01

Roč. 77, č. 8 (2012), s. 1063-1069 ISSN 0352-5139 Institutional research plan: CEZ:AV0Z40550506 Keywords : curcumin * antioxidant * UV-Vis spectrophotometry * DNA complexation * chemiluminescence Subject RIV: CC - Organic Chemistry Impact factor: 0.912, year: 2012

A nonpathogenic Fusarium oxysporum strain enhances phytoextraction of heavy metals by the hyperaccumulator Sedum alfredii Hance.

Science.gov (United States)

Zhang, Xincheng; Lin, Li; Chen, Mingyue; Zhu, Zhiqiang; Yang, Weidong; Chen, Bao; Yang, Xiaoe; An, Qianli

2012-08-30

Low biomass and shallow root systems limit the application of heavy metal phytoextraction by hyperaccumulators. Plant growth-promoting microbes may enhance hyperaccumulators'phytoextraction. A heavy metal-resistant fungus belonged to the Fusarium oxysporum complex was isolated from the Zn/Cd co-hyperaccumulator Sedum alfredii Hance grown in a Pb/Zn mined area. This Fusarium fungus was not pathogenic to plants but promoted host growth. Hydroponic experiments showed that 500 μM Zn(2+) or 50 μM Cd(2+) combined with the fungus increased root length, branches, and surface areas, enhanced nutrient uptake and chlorophyll synthesis, leading to more vigorous hyperaccumulators with greater root systems. Soil experiments showed that the fungus increased root and shoot biomass and S. alfredii-mediated heavy metal availabilities, uptake, translocation or concentrations, and thus increased phytoextraction of Zn (144% and 44%), Cd (139% and 55%), Pb (84% and 85%) and Cu (63% and 77%) from the original Pb/Zn mined soil and a multi-metal contaminated paddy soil. Together, the nonpathogenic Fusarium fungus was able to increase S. alfredii root systems and function, metal availability and accumulation, plant biomass, and thus phytoextraction efficiency. This study showed a great application potential for culturable indigenous fungi other than symbiotic mycorrhizas to enhance the phytoextraction by hyperaccumulators. Copyright © 2012 Elsevier B.V. All rights reserved.

The development and mechanical characterization of aluminium copper-carbon fiber metal matrix hybrid composite

Science.gov (United States)

Manzoor, M. U.; Feroze, M.; Ahmad, T.; Kamran, M.; Butt, M. T. Z.

2018-04-01

Metal matrix composites (MMCs) come under advanced materials that can be used for a wide range of industrial applications. MMCs contain a non-metallic reinforcement incorporated into a metallic matrix which can enhance properties over base metal alloys. Copper-Carbon fiber reinforced aluminium based hybrid composites were prepared by compo casting method. 4 weight % copper was used as alloying element with Al because of its precipitation hardened properties. Different weight compositions of composites were developed and characterized by mechanical testing. A significant improvement in tensile strength and micro hardness were found, before and after heat treatment of the composite. The SEM analysis of the fractured surfaces showed dispersed and embedded Carbon fibers within the network leading to the enhanced strength.

Spectroscopic enhancement in nanoparticles embedded glasses

Energy Technology Data Exchange (ETDEWEB)

Sahar, M. R., E-mail: mrahim057@gmail.com; Ghoshal, S. K., E-mail: mrahim057@gmail.com [Advanced Optical Material Research Group, Department of Physics, Faculty of Science, Universiti Teknologi Malaysia, 81310, Skudai, Johor Bahru, Johor (Malaysia)

2014-09-25

This presentation provides an overview of the recent progress in the enhancement of the spectroscopic characteristics of the glass embedded with nanoparticles (NPs). Some of our research activities with few significantly new results are highlighted and facilely analyzed. The science and technology dealing with the manipulation of the physical properties of rare earth doped inorganic glasses by embedding metallic NPs or nanoclusters produce the so-called 'nanoglass'. Meanwhile, the spectroscopic enhancement relates the intensity of the luminescence measured at certain transition. The enhancement which expectedly due to the 'plasmonics wave' (referring to the coherent coupling of photons to free electron oscillations called plasmon) occurs at the interface between a conductor and a dielectric. Plasmonics being an emerging concept in advanced optical material of nanophotonics has given this material the ability to exploit the optical response at nanoscale and opened up a new avenue in metal-based glass optics. There is a vast array of plasmonic NPs concepts yet to be explored, with applications spanning solar cells, (bio) sensing, communications, lasers, solid-state lighting, waveguides, imaging, optical data transfer, display and even bio-medicine. Localized surface plasmon resonance (LSPR) can enhance the optical response of nanoglass by orders of magnitude as observed. The luminescence enhancement and surface enhanced Raman scattering (SERS) are new paradigm of research. The enhancement of luminescence due to the influence of metallic NPs is the recurring theme of this paper.

Spin-exchange interaction between transition metals and metalloids in soft-ferromagnetic metallic glasses

Science.gov (United States)

Das, Santanu; Choudhary, Kamal; Chernatynskiy, Aleksandr; Choi Yim, Haein; Bandyopadhyay, Asis K.; Mukherjee, Sundeep

2016-06-01

High-performance magnetic materials have immense industrial and scientific importance in wide-ranging electronic, electromechanical, and medical device technologies. Metallic glasses with a fully amorphous structure are particularly suited for advanced soft-magnetic applications. However, fundamental scientific understanding is lacking for the spin-exchange interaction between metal and metalloid atoms, which typically constitute a metallic glass. Using an integrated experimental and molecular dynamics approach, we demonstrate the mechanism of electron interaction between transition metals and metalloids. Spin-exchange interactions were investigated for a Fe-Co metallic glass system of composition [(Co1-x Fe x )0.75B0.2Si0.05]96Cr4. The saturation magnetization increased with higher Fe concentration, but the trend significantly deviated from simple rule of mixtures. Ab initio molecular dynamics simulation was used to identify the ferromagnetic/anti-ferromagnetic interaction between the transition metals and metalloids. The overlapping band-structure and density of states represent ‘Stoner type’ magnetization for the amorphous alloys in contrast to ‘Heisenberg type’ in crystalline iron. The enhancement of magnetization by increasing iron was attributed to the interaction between Fe 3d and B 2p bands, which was further validated by valence-band study.

Plasmon-enhanced absorption in a metal nanoparticles and photosynthetic molecules hybrid system

Science.gov (United States)

Fan, Zhiyuan; Govorov, Alexander

2010-03-01

Photosystem I from cyanobacteria is one of nature's most efficient light harvesting complexes, converting light energy into electronic energy with a quantum yield of 100% and an energy yield about 58%. It is very attractive to the nanotechnology community because of its nanoscale dimensions and excellent optoelectronic properties. This protein has the potential to be utilized in devices such as solar cells, electric switches, photo-detectors, etc. However, there is one limiting factor for potential applications of a single monolayer of these photosynthetic proteins. One monolayer absorbs less than 1% of sunlight's energy, despite their excellent optoelectronic properties. Recently, experiments [1] have been conducted to enhance light absorption with the assistance of metal nanoparticles as artificial antenna for the photosystem I. Here, we present a theoretical description of the strong plasmon-assisted interactions between the metal nanoparticles and the optical dipoles of the reaction centers observed in the experiments. The resonance and off-resonance plasmon effects enhance the electromagnetic fields around the photosystem-I molecules and, in this way, lead to enhanced absorption. [4pt] [1] I. Carmeli, I. Lieberman, L. Kraversky, Zhiyuan Fan, A. O. Govorov, G. Markovich, and S. Richter, submitted.

FORMATION OF CARBON-ENHANCED METAL-POOR STARS IN THE PRESENCE OF FAR-ULTRAVIOLET RADIATION

Energy Technology Data Exchange (ETDEWEB)

Bovino, S.; Schleicher, D. R. G.; Latif, M. A. [Institut für Astrophysik Georg-August-Universität, Friedrich-Hund Platz 1, 37077 Göttingen (Germany); Grassi, T., E-mail: sbovino@astro.physik.uni-goettingen.de [Centre for Star and Planet Formation, Natural History Museum of Denmark, Øster Voldgade 5-7, 1350 Copenhagen (Denmark)

2014-08-01

Recent discoveries of carbon-enhanced metal-poor stars like SMSS J031300.36–670839.3 provide increasing observational insights into the formation conditions of the first second-generation stars in the universe, reflecting the chemical conditions after the first supernova explosion. Here, we present the first cosmological simulations with a detailed chemical network including primordial species as well as C, C{sup +}, O, O{sup +}, Si, Si{sup +}, and Si{sup 2+} following the formation of carbon-enhanced metal-poor stars. The presence of background UV flux delays the collapse from z = 21 to z = 15 and cool the gas down to the cosmic microwave background temperature for a metallicity of Z/Z {sub ☉} = 10{sup –3}. This can potentially lead to the formation of lower-mass stars. Overall, we find that the metals have a stronger effect on the collapse than the radiation, yielding a comparable thermal structure for large variations in the radiative background. We further find that radiative backgrounds are not able to delay the collapse for Z/Z {sub ☉} = 10{sup –2} or a carbon abundance as in SMSS J031300.36–670839.3.

Recent advances in plasmonic dye-sensitized solar cells

Science.gov (United States)

Rho, Won-Yeop; Song, Da Hyun; Yang, Hwa-Young; Kim, Ho-Sub; Son, Byung Sung; Suh, Jung Sang; Jun, Bong-Hyun

2018-02-01

Dye-sensitized solar cells (DSSCs) are among the best devices in generating electrons from solar light energy due to their high efficiency, low-cost in processing and transparency in building integrated photovoltaics. There are several ways to improve their energy-conversion efficiency, such as increasing light harvesting and electron transport, of which plasmon and 3-dimensional nanostructures are greatly capable. We review recent advances in plasmonic effects which depend on optimizing sizes, shapes, alloy compositions and integration of metal nanoparticles. Different methods to integrate metal nanoparticles into 3-dimensional nanostructures are also discussed. This review presents a guideline for enhancing the energy-conversion efficiency of DSSCs by utilizing metal nanoparticles that are incorporated into 3-dimensional nanostructures.

Highly sensitive determination of diclofenac based on resin beads and a novel polyclonal antibody by using flow injection chemiluminescence competitive immunoassay

Science.gov (United States)

Shi, Jing; Xu, Mingxia; Tang, Qinghui; Zhao, Kang; Deng, Anping; Li, Jianguo

2018-02-01

A novel flow injection chemiluminescence immunoassay for simple, sensitive and low-cost detection of diclofenac was established based on specific binding of antigen and antibody. Carboxylic resin beads used as solid phase carrier materials provided good biocompatibility and large surface-to-volume ratio for modifying more coating antigen. There was a competitive process between the diclofenac in solution and the immobilized coating antigen to react with the limited binding sites of the polyclonal antibody to form the immunocomplex. The second antibody labelled with horseradish peroxidase was introduced into the immunosensor and trapped by captured polyclonal antibody against diclofenac, which could effectively amplify chemiluminescence signals of luminol-PIP-H2O2. Under optimal conditions, the diclofenac could be detected quantitatively. The chemiluminescence intensity decreased linearly with the logarithm of the diclofenac concentration in the range of 0.1-100 ng mL- 1 with a detection limit of 0.05 ng mL- 1 at a signal-to-noise ratio of 3. The immunosensor exhibited high sensitivity, specificity and acceptable stability. This easy-operated and cost-effective analytical method could be valuable for the diclofenac determination in real water samples.

Multiple heavy metals extraction and recovery from hazardous electroplating sludge waste via ultrasonically enhanced two-stage acid leaching.

Science.gov (United States)

Li, Chuncheng; Xie, Fengchun; Ma, Yang; Cai, Tingting; Li, Haiying; Huang, Zhiyuan; Yuan, Gaoqing

2010-06-15

An ultrasonically enhanced two-stage acid leaching process on extracting and recovering multiple heavy metals from actual electroplating sludge was studied in lab tests. It provided an effective technique for separation of valuable metals (Cu, Ni and Zn) from less valuable metals (Fe and Cr) in electroplating sludge. The efficiency of the process had been measured with the leaching efficiencies and recovery rates of the metals. Enhanced by ultrasonic power, the first-stage acid leaching demonstrated leaching rates of 96.72%, 97.77%, 98.00%, 53.03%, and 0.44% for Cu, Ni, Zn, Cr, and Fe respectively, effectively separated half of Cr and almost all of Fe from mixed metals. The subsequent second-stage leaching achieved leaching rates of 75.03%, 81.05%, 81.39%, 1.02%, and 0% for Cu, Ni, Zn, Cr, and Fe that further separated Cu, Ni, and Zn from mixed metals. With the stabilized two-stage ultrasonically enhanced leaching, the resulting over all recovery rates of Cu, Ni, Zn, Cr and Fe from electroplating sludge could be achieved at 97.42%, 98.46%, 98.63%, 98.32% and 100% respectively, with Cr and Fe in solids and the rest of the metals in an aqueous solution discharged from the leaching system. The process performance parameters studied were pH, ultrasonic power, and contact time. The results were also confirmed in an industrial pilot-scale test, and same high metal recoveries were performed. Copyright 2010 Elsevier B.V. All rights reserved.

An ultrasensitive chemiluminescence immunoassay of chloramphenicol based on gold nanoparticles and magnetic beads.

Science.gov (United States)

Tao, Xiaoqi; Jiang, Haiyang; Yu, Xuezhi; Zhu, Jinghui; Wang, Xia; Wang, Zhanhui; Niu, Lanlan; Wu, Xiaoping; Shen, Jianzhong

2013-05-01

A competitive, direct, chemiluminescent immunoassay based on a magnetic beads (MBs) separation and gold nanoparticles (AuNPs) labelling technique to detect chloramphenicol (CAP) has been developed. Horseradish peroxidase (HRP)-labelled anti-CAP monoclonal antibody conjugated with AuNPs and antigen-immobilized MBs were prepared. After optimization parameters of immunocomplex MBs, the IC50 values of chemiluminescence magnetic nanoparticles immunoassay (CL-MBs-nano-immunoassay) were 0.017 µg L(-1) for extract method I and 0.17 µg L(-1) for extract method II. The immunoassay with two extract methods was applied to detect CAP in milk. Comparison of these two extract methods showed that extract method I was advantageous in better sensitivity, in which the sensitivity was 10 times compared to that of extract method II, while extract method II was superior in simple operation, suitable for high throughout screen. The recoveries were 86.7-98.0% (extract method I) and 80.0-103.0% (extract method II), and the coefficients of variation (CVs) were all recovery with both extract methods and high correlation with traditional ELISA kit in milk system confirmed that the immunomagnetic assay based on AuNPs exhibited promising potential in rapid field screening for trace CAP analysis. Copyright © 2013 John Wiley & Sons, Ltd.

Innovations in Advanced Materials and Metals Manufacturing Project (IAM2)

Energy Technology Data Exchange (ETDEWEB)

Scott, Elizabeth [Columbia River Economic Development Council, Vancouver, WA (United States)

2017-01-06

This project, under the Jobs and Innovation Accelerator Challenge, Innovations in Advanced Materials and Metals Manufacturing Project, contracted with Cascade Energy to provide a shared energy project manager engineer to work with five different companies throughout the Portland metro grant region to implement ten energy efficiency projects and develop a case study to analyze the project model. As a part of the project, the energy project manager also looked into specific new technologies and methodologies that could change the way energy is consumed by manufacturers—from game-changing equipment and technology to monitor energy use to methodologies that change the way companies interact and use their machines to reduce energy consumption.

Chemiluminescence ELISA for the detection of oxidative DNA base damage using anti-8-hydroxy-2'-deoxyguanosine antibody. Application to the detection of irradiated foods

International Nuclear Information System (INIS)

Kikuchi, Masahiro; Funayama, Tomoo; Sakashita, Tetsuya; Satoh, Katsuya; Narumi, Issay; Kobayashi, Yashihiko; Gunawardane, Chaminda R.; Alam, Md. Khorshed; Dzomir, A. Zainuri Mohd.; Pitipanaarachchi, Ramya C.; Hamada, Nobuyuki; Wada, Seiichi

2007-01-01

Since ionizing radiation is used for sterilizing or lowering the microbial content of foods as a means of reducing food losses and securing food safety, the development of versatile detection methods of irradiated foods is necessary for appropriate management. In an effort to distinguish between irradiated and non-irradiated food, a method based on the detection of oxidative DNA base damage using the chemiluminescence enzyme-linked immunosorbent assay (ELISA) with anti-8-hydroxy-2'-deoxyguanosine antibody was developed. In the course of optimizing the reaction conditions for the ELISA, a 30-mer synthetic oligonucleotide containing 8-hydroxyguanine (8-oxoG) was used. Under the optimized conditions, the correlation between chemiluminescence intensity and 8-oxoG content in oligonucleotides was obtained. It was shown that this chemiluminescence ELISA method could be applied to chicken, beef and pork that were irradiated with over 3 kGy. Twenty milligrams of a loaf of meat was sufficient to distinguish between irradiated and non-irradiated meat by this method. (author)

Enhancement of deuteron-fusion reactions in metals and experimental implications

International Nuclear Information System (INIS)

Huke, A.; Heide, P.; Czerski, K.; Ruprecht, G.; Targosz, N.; Zebrowski, W.

2008-01-01

Recent measurements of the reaction 2 H(d,p) 3 H in metallic environments at very low energies performed by different experimental groups point to an enhanced electron screening effect. However, the resulting screening energies differ strongly for diverse host metals and different experiments. Here, we present new experimental results and investigations of interfering processes in the irradiated targets. These measurements inside metals set special challenges and pitfalls that make them and the data analysis particularly error prone. There are multiparameter collateral effects that are crucial for the correct interpretation of the observed experimental yields. They mainly originate from target surface contaminations owing to residual gases in the vacuum as well as from inhomogeneities and instabilities in the deuteron density distribution in the targets. To address these problems an improved differential analysis method beyond the standard procedures has been implemented. Profound scrutiny of the other experiments demonstrates that the observed unusual changes in the reaction yields are mainly due to deuteron density dynamics simulating the alleged screening energy values. The experimental results are compared with different theoretical models of the electron screening in metals. The Debye-Hueckel model that has been previously proposed to explain the influence of the electron screening on both nuclear reactions and radioactive decays can be clearly excluded

Measurements of essential oil extract and antioxidant in Syrian Myrtus communis L. leaves using photo chemiluminescence assay

International Nuclear Information System (INIS)

Zayzafoon, G.; Odeh, A.; Mahzia, Y.

2012-01-01

The essential oil extracts and antioxidant measurements of Syrian Myrtus communis L. leaves as hydrophilic and hydrophobic existence species have been carried out. The plant leaves as a source of antioxidants was tested by the influence of its aqueous and essential oil extracts on the yield of photo chemiluminescence, PCL solution applying very sensitive and reliable method. By means of a photo chemiluminescence assay, it was possible to assess the total antioxidants capacity of hydrophilic and hydrophobic species existence in Syrian Myrtus communis L. leaves. It has been found that, the integral antioxidant capacity measurements value of Syrian Myrtus communis L. leaves was found in Kurdaha site which has a value of 465.67 1.18 nmol TE/g DM (total Trolox equivalent /gram of Dry material) . The following three mainly chemical species were found in the essential oil extracts: -Pinene, Cineole and Limonene. (author)

Experimental observation of percolation-enhanced nonlinear light scattering from semicontinuous metal films

Science.gov (United States)

Breit, M.; Podolskiy, V. A.; Grésillon, S.; von Plessen, G.; Feldmann, J.; Rivoal, J. C.; Gadenne, P.; Sarychev, Andrey K.; Shalaev, Vladimir M.

2001-09-01

Strongly enhanced second-harmonic generation (SHG), which is characterized by a nearly isotropic intensity distribution, is observed for gold-glass films near the percolation threshold. The diffuselike SHG scattering, which can be thought of as nonlinear critical opalescence, is in sharp contrast with highly collimated linear reflection and transmission from these nanostructured semicontinuous metal films. Our observations, which can be explained by giant fluctuations of local nonlinear sources for SHG due to plasmon localization, verify recent predictions of percolation-enhanced nonlinear scattering.

Application of Box–Behnken design in the optimization of new peroxyoxalate–H2O2 chemiluminescence system using furan derivatives as blue activators

International Nuclear Information System (INIS)

Chaichi, M.J.; Azizi, S.N.; Alijanpour, O.; Heidarpour, M.; Qandalee, M.

2013-01-01

The non-commercially synthesized and purified furan derivatives are of great interest as fluorescent emitters for peroxyoxalate chemiluminescence (PO-CL). The reaction of oxalic ester such as bis-(2,4,6-trichloro-phenyl) oxalate (TCPO) with H 2 O 2 can lead to the excitation of an appropriate activator via the formation of a 1,2-dioxetanedione intermediate. In this study, two furan derivatives were used as activators which produce a blue light in the chemiluminescence systems. In the following, the Box–Behnken design matrix and response surface methodology (RSM) have been applied to design the experiments to study the relationship between the chemiluminescence intensities and the three most important operating variables such as sodium salicylate (5×10 −4 –5×10 −3 M), furan (10 −5 –10 −3 M) and hydrogen peroxide (10 −3 –10 −1 M) concentrations, and also to evaluate the interactive effects of these variables on the CL emission of TCPO system. Totally 15 experiments were conducted in the present study towards the construction of a quadratic model. Independent variables of sodium salicylate, hydrogen peroxide and furan concentration have the significance value of p=0.05, in both the systems, which explicitly shows the importance of these variables in the CL emission of TCPO. Values of Prob>F less than 0.0001 indicated that the model terms are significant for the CL emission of TCPO. Moreover, the regression equation coefficients were calculated and the data fitted to a second-order polynomial equation for CL emission of TCPO. -- Highlights: ► Furan derivatives are used as activators for peroxyoxalate chemiluminescence. ► The activators produce a blue light in the chemiluminescence system. ► The Box–Behnken design matrix and response surface methodology (RSM) is used. ► The most important variables are sodium salicylate, furan and hydrogen peroxide. ► The data are fitted to a second-order polynomial equation for CL emission of TCPO

Experimental investigation of solidification in metal foam enhanced phase change material

Science.gov (United States)

Beyne, W.; Bağci, O.; Huisseune, H.; Canière, H.; Danneels, J.; Daenens, D.; De Paepe, M.

2017-10-01

A major challenge for the use of phase change materials (PCMs) in thermal energy storage (TES) is overcoming the low thermal conductivity of PCM’s. The low conductivity gives rise to limited power during charging and discharging TES. Impregnating metal foam with PCM, however, has been found to enhance the heat transfer. On the other hand, the effect of foam parameters such as porosity, pore size and material type has remained unclear. In this paper, the effect of these foam parameters on the solidification time is investigated. Different samples of PCM-impregnated metal foam were experimentally tested and compared to one without metal foam. The samples varied with respect to choice of material, porosity and pore size. They were placed in a rectangular cavity and cooled from one side using a coolant flowing through a cold plate. The other sides of the rectangular cavity were Polymethyl Methacrylate (PM) walls exposed to ambient. The temperature on the exterior walls of the cavity was monitored as well as the coolant flow rate and its temperature. The metal foam inserts reduced the solidification times by at least 25 %. However, the difference between the best performing and worst performing metal foam is about 28 %. This shows a large potential for future research.

Enhanced bioleaching efficiency of metals from E-wastes driven by biochar

Energy Technology Data Exchange (ETDEWEB)

Wang, Shuhua; Zheng, Yue; Yan, Weifu; Chen, Lixiang [CAS Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, 361021 (China); University of Chinese Academy of Sciences, Beijing, 100049 (China); Dummi Mahadevan, Gurumurthy [CAS Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, 361021 (China); Zhao, Feng, E-mail: fzhao@iue.ac.cn [CAS Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, 361021 (China)

2016-12-15

Electronic wastes (E-wastes) contain a huge amount of valuable metals that are worth recovering. Bioleaching has attracted widespread attention as an environment-friendly and low-cost technology for the recycling of E-wastes. To avoid the disadvantages of being time-consuming or having a relatively low efficiency, biochar with redox activity was used to enhance bioleaching efficiency of metals from a basic E-waste (i.e., printed circuit boards in this study). The role of biochar was examined through three basic processes: Carbon-mediated, Sulfur-mediated and Iron-mediated bioleaching pathways. Although no obvious enhancement of bioleaching performance was observed in the C-mediated and S-mediated systems, Fe-mediated bioleaching was significantly promoted by the participation of biochar, and its leaching time was decreased by one-third compared with that of a biochar-free system. By mapping the dynamic concentration of Fe(II) and Cu(II), biochar was proved to facilitate the redox action between Fe(II) to Fe(III), which resulted in effective leaching of Cu. Two dominant functional species consisting of Alicyclobacillus spp. and Sulfobacillus spp. may cooperate in the Fe-mediated bioleaching system, and the ratio of these two species was regulated by biochar for enhancing the efficiency of bioleaching. Hence, this work provides a method to improve bioleaching efficiency with low-cost solid redox media.

Enhanced bioleaching efficiency of metals from E-wastes driven by biochar

International Nuclear Information System (INIS)

Wang, Shuhua; Zheng, Yue; Yan, Weifu; Chen, Lixiang; Dummi Mahadevan, Gurumurthy; Zhao, Feng

2016-01-01

Electronic wastes (E-wastes) contain a huge amount of valuable metals that are worth recovering. Bioleaching has attracted widespread attention as an environment-friendly and low-cost technology for the recycling of E-wastes. To avoid the disadvantages of being time-consuming or having a relatively low efficiency, biochar with redox activity was used to enhance bioleaching efficiency of metals from a basic E-waste (i.e., printed circuit boards in this study). The role of biochar was examined through three basic processes: Carbon-mediated, Sulfur-mediated and Iron-mediated bioleaching pathways. Although no obvious enhancement of bioleaching performance was observed in the C-mediated and S-mediated systems, Fe-mediated bioleaching was significantly promoted by the participation of biochar, and its leaching time was decreased by one-third compared with that of a biochar-free system. By mapping the dynamic concentration of Fe(II) and Cu(II), biochar was proved to facilitate the redox action between Fe(II) to Fe(III), which resulted in effective leaching of Cu. Two dominant functional species consisting of Alicyclobacillus spp. and Sulfobacillus spp. may cooperate in the Fe-mediated bioleaching system, and the ratio of these two species was regulated by biochar for enhancing the efficiency of bioleaching. Hence, this work provides a method to improve bioleaching efficiency with low-cost solid redox media.

Enhanced bioleaching efficiency of metals from E-wastes driven by biochar.

Science.gov (United States)

Wang, Shuhua; Zheng, Yue; Yan, Weifu; Chen, Lixiang; Dummi Mahadevan, Gurumurthy; Zhao, Feng

2016-12-15

Electronic wastes (E-wastes) contain a huge amount of valuable metals that are worth recovering. Bioleaching has attracted widespread attention as an environment-friendly and low-cost technology for the recycling of E-wastes. To avoid the disadvantages of being time-consuming or having a relatively low efficiency, biochar with redox activity was used to enhance bioleaching efficiency of metals from a basic E-waste (i.e., printed circuit boards in this study). The role of biochar was examined through three basic processes: Carbon-mediated, Sulfur-mediated and Iron-mediated bioleaching pathways. Although no obvious enhancement of bioleaching performance was observed in the C-mediated and S-mediated systems, Fe-mediated bioleaching was significantly promoted by the participation of biochar, and its leaching time was decreased by one-third compared with that of a biochar-free system. By mapping the dynamic concentration of Fe(II) and Cu(II), biochar was proved to facilitate the redox action between Fe(II) to Fe(III), which resulted in effective leaching of Cu. Two dominant functional species consisting of Alicyclobacillus spp. and Sulfobacillus spp. may cooperate in the Fe-mediated bioleaching system, and the ratio of these two species was regulated by biochar for enhancing the efficiency of bioleaching. Hence, this work provides a method to improve bioleaching efficiency with low-cost solid redox media. Copyright © 2016 Elsevier B.V. All rights reserved.

One-process fabrication of metal hierarchical nanostructures with rich nanogaps for highly-sensitive surface-enhanced Raman scattering

International Nuclear Information System (INIS)

Liu, Gui-qiang; Yu, Mei-dong; Liu, Zheng-qi; Liu, Xiao-shan; Huang, Shan; Pan, Ping-ping; Wang, Yan; Liu, Mu-lin; Gu, Gang

2015-01-01

One-process fabrication of highly active and reproducible surface-enhanced Raman scattering (SERS) substrates via ion beam deposition is reported. The fabricated metal–dielectric–metal (MDM) hierarchical nanostructure possesses rich nanogaps and a tunable resonant cavity. Raman scattering signals of analytes are dramatically strengthened due to the strong near-field coupling of localized surface plasmon resonances (LSPRs) and the strong interaction of LSPRs of metal NPs with surface plasmon polaritons (SPPs) on the underlying metal film by crossing over the dielectric spacer. The maximum Raman enhancement for the highest Raman peak at 1650 cm −1 is 13.5 times greater than that of a single metal nanoparticle (NP) array. Moreover, the SERS activity can be efficiently tailored by varying the size and number of voids between adjacent metal NPs and the thickness of the dielectric spacer. These findings may broaden the scope of SERS applications of MDM hierarchical nanostructures in biomedical and analytical chemistry. (paper)

Tuning CNT Properties for Metal-Free Environmental Catalytic Applications

Directory of Open Access Journals (Sweden)

Raquel P. Rocha

2016-06-01

Full Text Available The application of carbon nanotubes (CNTs as metal-free catalysts is a novel approach for heterogeneous liquid phase catalytic systems. Textural and chemical modifications by liquid/gas phase or mechanical treatments, as well as solid state reactions, were successfully applied to obtain carbon nanotubes with different surface functionalities. Oxygen, nitrogen, and sulfur are the most common heteroatoms introduced on the carbon surface. This short-review highlights different routes used to develop metal-free carbon nanotube catalysts with enhanced properties for Advanced Oxidation Processes.

The critical particle size for enhancing thermal conductivity in metal nanoparticle-polymer composites

Science.gov (United States)

Lu, Zexi; Wang, Yan; Ruan, Xiulin

2018-02-01

Polymers used as thermal interface materials are often filled with high-thermal conductivity particles to enhance the thermal performance. Here, we have combined molecular dynamics and the two-temperature model in 1D to investigate the impact of the metal filler size on the overall thermal conductivity. A critical particle size has been identified above which thermal conductivity enhancement can be achieved, caused by the interplay between high particle thermal conductivity and the added electron-phonon and phonon-phonon thermal boundary resistance brought by the particle fillers. Calculations on the SAM/Au/SAM (self-assembly-monolayer) system show a critical thickness Lc of around 10.8 nm. Based on the results, we define an effective thermal conductivity and propose a new thermal circuit analysis approach for the sandwiched metal layer that can intuitively explain simulation and experimental data. The results show that when the metal layer thickness decreases to be much smaller than the electron-phonon cooling length (or as the "thin limit"), the effective thermal conductivity is just the phonon portion, and electrons do not participate in thermal transport. As the thickness increases to the "thick limit," the effective thermal conductivity recovers the metal bulk value. Several factors that could affect Lc are discussed, and it is discovered that the thermal conductivity, thermal boundary resistance, and the electron-phonon coupling factor are all important in controlling Lc.

Comparison of Au and Ag nanoshells' metal-enhanced fluorescence

International Nuclear Information System (INIS)

Liaw, Jiunn-Woei; Chen, Huang-Chih; Kuo, Mao-Kuen

2014-01-01

The average enhancement factors of Au and Ag nanoshells (NSs) were analyzed theoretically to compare their overall performances on metal-enhanced fluorescence. We used the Mie theory and dyadic Green's functions to calculate the excitation rate and apparent quantum yield of NS interacting with a plane wave and a dipole, respectively, and then to obtain the enhancement factor. Moreover, the average enhancement factor (AEF) of NS on the fluorescence of a nearby molecule was obtained by averaging all possible orientations and locations of the molecule with a constant distance from NS. Our results show that the maximum AEF of Au NS occurs at the wavelength of the dipole mode, which is broadband. In contrast, the maximum AEF of Ag NS is at the narrowband quadrupole mode. In addition, the Stokes shift effect on AEF was studied for Au and Ag NSs. - Highlights: • The average enhancement factors of Au and Ag nanoshells were analyzed theoretically. • The maximum AEF of Au NS occurs at the wavelength of the dipole mode. • The maximum AEF of Ag NS is at the narrowband quadrupole mode. • The Stokes shift effect on AEF is discussed for Au and Ag NSs

Large capacitance enhancement induced by metal-doping in graphene-based supercapacitors: a first-principles-based assessment.

Science.gov (United States)

Paek, Eunsu; Pak, Alexander J; Hwang, Gyeong S

2014-08-13

Chemically doped graphene-based materials have recently been explored as a means to improve the performance of supercapacitors. In this work, we investigate the effects of 3d transition metals bound to vacancy sites in graphene with [BMIM][PF6] ionic liquid on the interfacial capacitance; these results are compared to the pristine graphene case with particular attention to the relative contributions of the quantum and electric double layer capacitances. Our study highlights that the presence of metal-vacancy complexes significantly increases the availability of electronic states near the charge neutrality point, thereby enhancing the quantum capacitance drastically. In addition, the use of metal-doped graphene electrodes is found to only marginally influence the microstructure and capacitance of the electric double layer. Our findings indicate that metal-doping of graphene-like electrodes can be a promising route toward increasing the interfacial capacitance of electrochemical double layer capacitors, primarily by enhancing the quantum capacitance.

The application of automatic chemiluminescence machine in rapid immune detection

International Nuclear Information System (INIS)

Lin Aizhen; Li Xuanwei; Chen Binhong; Li Zhenqian; Chen Zhaoxuan

2004-01-01

Objective: To provide high-quality, rapid and dependable result for clinical practice, and give satisfactory service to patients of different economical status by supplementation with other labeling immune examination. With an innovative attitude, we carried out efficient technical reform on ACS180 automatic chemiluminescence machine, making it possible for patients to complete the whole process including examination, check-out, diagnosis and getting drugs. The reported will be issued within an hour, thus a rapid immune detection service was established in out-patients department. Methods: 1. ACS-180 automatic chemiluminescence machine is used based on the principle of chemiluminescence immune methods. 2. The reagents are provided by Ciba-Comig Company of USA, composed of anti acridinium ester antibody of liquid phase and particulate antigen of solid phase wrapped in magnetic powder. 3. Calibration and quality control: high and low concentration are set for each calibration fluid with attached standard curve. Product for quality controlling includes three concentration of low, moderate and high. Results: 1. rapid machine detection for sample: serum is replaced with plasma coagulated by heparin, and comparison among series of methods using serum or plasma suggest no significant difference exists. 2. The problem about fasting detection: chemiluminescence machine measure optical density directly, with the results hardly being influenced by turbidity. But attention should be paid to the treatment of lipid turbid samples. 3. Other innovations: (1) direct placement of sample tube on machine: a cushion is placed on sample plate to transfer sample to machine directly after centrifugation, saving time and reducing the accident in sample transference. (2) for HCG quantification in blood and urine, 'gold criteria' is used firstly in screening to determine approximately the dilution range, with an advantage of saving time and reagent as well as accuracy. (3) we design a

ENVIROMETAL TECHNOLOGIES, INC., METAL-ENHANCED DECHLORINATION OF VOLATILE ORGANIC COMPOUNDS USING AN IN-SITU REACTIVE IRON WALL

Science.gov (United States)

This report summarizes the results of a field demonstration conducted under the SITE program. The technology that was demonstrated was a metal-enhanced dechlorination process developed by EnviroMetal Technologies, Inc. to treat groundwater contaminated with chlorinated volatile ...

Direct electroplating of plastic for advanced electrical applications

DEFF Research Database (Denmark)

Islam, Aminul; Hansen, Hans Nørgaard; Tang, Peter Torben

2017-01-01

Electrodeposition or electroplating is predominantly applied to metallic components. Electroplating of plastics is possible in some cases where an initial electroless plating layer of nickel or copper is made to provide a conductive surface on the plastic part. This paper proposes a method...... for direct electroplating of plastic eliminating the need for slow and expensive processes like electroless metal deposition, PVD coating, painting with conductive inks etc. The results obtained from the test demonstrate the potential of direct electroplating of plastic to enhance the electrical conductivity...... and the use of electroplated plastics for advanced applications like Moulded Interconnect Devices (MIDs)....

FAA/NASA International Symposium on Advanced Structural Integrity Methods for Airframe Durability and Damage Tolerance

Energy Technology Data Exchange (ETDEWEB)

Harris, C.E.

1994-09-01

International technical experts in durability and damage tolerance of metallic airframe structures were assembled to present and discuss recent research findings and the development of advanced design and analysis methods, structural concepts, and advanced materials. The symposium focused on the dissemination of new knowledge and the peer-review of progress on the development of advanced methodologies. Papers were presented on: structural concepts for enhanced durability, damage tolerance, and maintainability; new metallic alloys and processing technology; fatigue crack initiation and small crack effects; fatigue crack growth models; fracture mechanics failure, criteria for ductile materials; structural mechanics methodology for residual strength and life prediction; development of flight load spectra for design and testing; and advanced approaches to resist corrosion and environmentally assisted fatigue. Separate abstracts have been indexed for articles from this report.

Conglutinin exhibits a complement-dependent enhancement of the respiratory burst of phagocytes stimulated by E. coli

DEFF Research Database (Denmark)

Friis, P; Svehag, S E; Andersen, Ove

1991-01-01

. Conglutinin enhances, in a dose-dependent manner, the respiratory burst of spleen cells stimulated with serum-opsonized Escherichia coli. The enhancement was only demonstrable in the presence of a functional complement system. The conglutinin-mediated enhancement of the respiratory burst was inhibited......Conglutinin is a mammalian C-type lectin which shows anti-bacterial activity when tested in vivo and in vitro. This study concerns the effect of conglutinin on the respiratory burst of murine spleen cells, using a chemiluminescence assay for measurement of generated reactive oxygen metabolites...

Enhancement of light absorption in polyazomethines due to plasmon excitation on randomly distributed metal nanoparticles

Science.gov (United States)

Wróbel, P.; Antosiewicz, T. J.; Stefaniuk, T.; Ciesielski, A.; Iwan, A.; Wronkowska, A. A.; Wronkowski, A.; Szoplik, T.

2015-05-01

In photovoltaic devices, metal nanoparticles embedded in a semiconductor layer allow the enhancement of solar-toelectric energy conversion efficiency due to enhanced light absorption via a prolonged optical path, enhanced electric fields near the metallic inclusions, direct injection of hot electrons, or local heating. Here we pursue the first two avenues. In the first, light scattered at an angle beyond the critical angle for reflection is coupled into the semiconductor layer and confined within such planar waveguide up to possible exciton generation. In the second, light is trapped by the excitation of localized surface plasmons on metal nanoparticles leading to enhanced near-field plasmon-exciton coupling at the peak of the plasmon resonance. We report on results of a numerical experiment on light absorption in polymer- (fullerene derivative) blends, using the 3D FDTD method, where exact optical parameters of the materials involved are taken from our recent measurements. In simulations we investigate light absorption in randomly distributed metal nanoparticles dispersed in polyazomethine-(fullerene derivative) blends, which serve as active layers in bulkheterojunction polymer solar cells. In the study Ag and Al nanoparticles of different diameters and fill factors are diffused in two air-stable aromatic polyazomethines with different chemical structures (abbreviated S9POF and S15POF) mixed with phenyl-C61-butyric acid methyl ester (PCBM) or [6,6]-phenyl-C71-butyric acid methyl ester (PC71BM). The mixtures are spin coated on a 100 nm thick Al layer deposited on a fused silica substrate. Optical constants of the active layers are taken from spectroscopic ellipsometry and reflectance measurements using a rotating analyzer type ellipsometer with auto-retarder performed in the wavelength range from 225 nm to 2200 nm. The permittivities of Ag and Al particles of diameters from 20 to 60 nm are assumed to be equal to those measured on 100 to 200 nm thick metal films.

Simultaneous determination of chromium(III) and chromium(VI) in aqueous solutions by ion chromatography and chemiluminescence detection

DEFF Research Database (Denmark)

Gammelgaard, Bente; Jøns, O; Nielsen, B

1992-01-01

A method for the simultaneous determination of chromium(iii) and chromium(vi) in a flow system based on chemiluminescence was developed. A Dionex cation-exchange guard column was used to separate chromium(iii) from chromium(vi), and chromium(vi) was reduced by potassium sulfite, whereupon both...

The fabrication of magnetic particle-based chemiluminescence immunoassay for human epididymis protein-4 detection in ovarian cancer

Directory of Open Access Journals (Sweden)

Xiaoling Fu

2018-03-01

Full Text Available The magnetic particles have a significant influence on the immunoassay detection and cancer therapy. Herein, the chemiluminescence immunoassay combined with the magnetic particles (MPCLIA was presented for the clinical determination and analysis of human epididymis protein 4 (HE4 in the human serum. Under the optimized experiment conditions, the secure MPCLIA method can detect HE4 in the broader range of 0–1000 pmol/L, with a lower detection limit of 1.35 pmol/L. The satisfactory recovery rate of the method in the serum ranged from 83.62% to 105.10%, which was well within the requirement of clinical analysis. Moreover, the results showed the good correlation with enzyme-linked immunosorbent assay (ELISA, with the correlation coefficient of 0.9589. This proposed method has been successfully applied to the clinical determination of HE4 in the human serum. Keywords: Chemiluminescence immunoassay, Magnetic particles, Human epididymis protein 4

Advances in brazing science, technology and applications

CERN Document Server

2013-01-01

Brazing processes offer enhanced control, adaptability and cost-efficiency in the joining of materials. Unsurprisingly, this has lead to great interest and investment in the area. Drawing on important research in the field, Advances in brazing provides a clear guide to the principles, materials, methods and key applications of brazing. Part one introduces the fundamentals of brazing, including molten metal wetting processes, strength and margins of safety of brazed joints, and modeling of associated physical phenomena. Part two goes on to consider specific materials, such as super alloys, filler metals for high temperature brazing, diamonds and cubic boron nitride, and varied ceramics and intermetallics. The brazing of carbon-carbon (C/C) composites to metals is also explored before applications of brazing and brazed materials are discussed in part three. Brazing of cutting materials, use of coating techniques, and metal-nonmetal brazing for electrical, packaging and structural applications are reviewed, alon...

Chemiluminescence response of whole blood and separated blood cells in cases of experimentally induced pancreatitis and MDTQ-DA-Trasylol-ascorbic acid therapy

Energy Technology Data Exchange (ETDEWEB)

Zimmermann, T.; Schuster, R.; Lauschke, G.; Trausch, M. (Medical Academy of Dresden (Germany). Department of Surgery); Albrecht, S. (Medical Academy of Dresden (Germany). Institute of Clinical Chemistry); Kopprasch, S.; Kuehne, H. (Medical Academy of Dresden (Germany). Institute of Pathological Biochemistry)

1991-12-24

The formation of reactive O{sub 2} species in the pancreas of pigs after induction of necrotizing or oedematous pancreatitis was studied by means of luminol- and lucigenin-sensitized chemiluminescence. The effect of 2,2-dimethyl-4-methanesulphonic acid-1,2-dihydroquinoline in combination with Trasylol and ascorbic acid was studied in vivo. This combined therapy leads to a reduction in the chemiluminescence response by 50-70% with prevention of pancreatogenic shock and multiple organ failure by improvement of the gluthathione status. A combination of radical traps, kallikrein inhibitors and natural antioxidative sub-stances is an efficient alternative therapy in cases of acute pancrea-titis. (author). 10 refs.; 5 figs.

Multi-metal, Multi-wavelength Surface-Enhanced Raman Spectroscopy Detection of Neurotransmitters.

Science.gov (United States)

Moody, Amber S; Sharma, Bhavya

2018-04-05

The development of a sensor for the rapid and sensitive detection of neurotransmitters could provide a pathway for the diagnosis of neurological diseases, leading to the discovery of more effective treatment methods. We investigate the use of surface enhanced Raman spectroscopy (SERS) based sensors for the rapid detection of melatonin, serotonin, glutamate, dopamine, GABA, norepinephrine, and epinephrine. Previous studies have demonstrated SERS detection of neurotransmitters; however, there has been no comprehensive study on the effect of the metal used as the SERS substrate or the excitation wavelength used for detection. Here, we present the detection of 7 neurotransmitters using both silver and gold nanoparticles at excitation wavelengths of 532, 633, and 785 nm. Over the range of wavelengths investigated, the SERS enhancement on the silver and gold nanoparticles varies, with an average enhancement factor of 10 5 -10 6 . The maximum SERS enhancement occurs at an excitation wavelength of 785 nm for the gold nanoparticles and at 633 nm for the silver nanoparticles.

Enhancing Charge Carrier Lifetime in Metal Oxide Photoelectrodes through Mild Hydrogen Treatment

KAUST Repository

Jang, Ji-Wook

2017-08-25

Widespread application of solar water splitting for energy conversion is largely dependent on the progress in developing not only efficient but also cheap and scalable photoelectrodes. Metal oxides, which can be deposited with scalable techniques and are relatively cheap, are particularly interesting, but high efficiency is still hindered by the poor carrier transport properties (i.e., carrier mobility and lifetime). Here, a mild hydrogen treatment is introduced to bismuth vanadate (BiVO4), which is one of the most promising metal oxide photoelectrodes, as a method to overcome the carrier transport limitations. Time-resolved microwave and terahertz conductivity measurements reveal more than twofold enhancement of the carrier lifetime for the hydrogen-treated BiVO4, without significantly affecting the carrier mobility. This is in contrast to the case of tungsten-doped BiVO4, although hydrogen is also a donor type dopant in BiVO4. The enhancement in carrier lifetime is found to be caused by significant reduction of trap-assisted recombination, either via passivation or reduction of deep trap states related to vanadium antisite on bismuth or vanadium interstitials according to density functional theory calculations. Overall, these findings provide further insights on the interplay between defect modulation and carrier transport in metal oxides, which benefit the development of low-cost, highly-efficient solar energy conversion devices.

Sensitive and selective determination of fluvoxamine maleate using a sensitive chemiluminescence system based on the alkaline permanganate-Rhodamine B-gold nanoparticles reaction.

Science.gov (United States)

Hassanzadeh, Javad; Amjadi, Mohammad

2015-06-01

A high-yield chemiluminescence (CL) system based on the alkaline permanganate-Rhodamine B reaction was developed for the sensitive determination of fluvoxamine maleate (Flu). Rhodamine B is oxidized by alkaline KMnO4 and a weak CL emission is produced. It was demonstrated that gold nanoparticles greatly enhance this CL emission due to their interaction with Rhodamine B molecules. It is also observed that sodium dodecyl sulfate, an anionic surfactant, can strongly increase this enhancement. In addition, it was demonstrated that a notable decrease in the CL intensity is observed in the presence of Flu. This may be related to Flu oxidation with KMnO4 . There is a linear relationship between the decrease in CL intensity and the Flu concentration over a range of 2-300 µg/L. A new simple, rapid and sensitive CL method was developed for the determination of Flu with a detection limit (3s) of 1.35 µg/L. The proposed method was used for the determination of Flu in pharmaceutical and urine samples. Copyright © 2014 John Wiley & Sons, Ltd.

Involvement of Programmed Cell Death in Neurotoxicity of Metallic Nanoparticles: Recent Advances and Future Perspectives

Science.gov (United States)

Song, Bin; Zhou, Ting; Liu, Jia; Shao, LongQuan

2016-11-01

The widespread application of metallic nanoparticles (NPs) or NP-based products has increased the risk of exposure to NPs in humans. The brain is an important organ that is more susceptible to exogenous stimuli. Moreover, any impairment to the brain is irreversible. Recently, several in vivo studies have found that metallic NPs can be absorbed into the animal body and then translocated into the brain, mainly through the blood-brain barrier and olfactory pathway after systemic administration. Furthermore, metallic NPs can cross the placental barrier to accumulate in the fetal brain, causing developmental neurotoxicity on exposure during pregnancy. Therefore, metallic NPs become a big threat to the brain. However, the mechanisms underlying the neurotoxicity of metallic NPs remain unclear. Programmed cell death (PCD), which is different from necrosis, is defined as active cell death and is regulated by certain genes. PCD can be mainly classified into apoptosis, autophagy, necroptosis, and pyroptosis. It is involved in brain development, neurodegenerative disorders, psychiatric disorders, and brain injury. Given the pivotal role of PCD in neurological functions, we reviewed relevant articles and tried to summarize the recent advances and future perspectives of PCD involvement in the neurotoxicity of metallic NPs, with the purpose of comprehensively understanding the neurotoxic mechanisms of NPs.

Highly sensitive trivalent copper chelate–luminol chemiluminescence system for capillary electrophoresis chiral separation and determination of ofloxacin enantiomers in urine samples

Directory of Open Access Journals (Sweden)

Hao-Yue Xie

2014-12-01

Full Text Available A simple, fast and sensitive capillary electrophoresis (CE strategy combined with chemiluminescence (CL detection for analysis of ofloxacin (OF enantiomers was established in the present work. Sulfonated β-cyclodextrin (β-CD was used as the chiral additive being added into the running buffer of luminol–diperiodatocuprate (III (K5[Cu(HIO62], DPC chemiluminescence system. Under the optimum conditions, the proposed method was successfully applied to separation and analysis of OF enantiomers with the detection limits (S/N=3 of 8.0 nM and 7.0 nM for levofloxacin and dextrofloxacin, respectively. The linear ranges were both 0.010–100 μM. The method was utilized for analyzing OF in urine; the results obtained were satisfactory and recoveries were 89.5–110.8%, which demonstrated the reliability of this method. This approach can also be further extended to analyze different commercial OF medicines. Keywords: Ofloxacin, Chiral analysis, Sulfonated-β-CD, Capillary electrophoresis, Chemiluminescence

Enhancement of isotope exchange reactions over ceramic breeder material by deposition of catalyst metal

International Nuclear Information System (INIS)

Narisato, Y.; Munakata, K.; Koga, A.; Yokoyama, Y.; Takata, T.; Okabe, H.

2004-01-01

The deposition of catalyst metals in ceramic breeders could enhance the release rate of tritium due to the promotion of isotope exchange reactions taking place at the interface of the breeder surface and the sweep gas. In this work, the authors examined the effects of catalytic active metal deposited on lithium titanate on the isotope exchange reactions. With respect to the virgin lithium titanate, it was found that the rate of the isotope exchange reactions taking place on the surface is quite low. However, the deposition of palladium greatly increased the exchange reaction rate. The effect of the amounts of deposited palladium on the isotope exchange reaction rate was also investigated. The results indicate that the exchange reactions are still enhanced even if the amounts of deposited palladium are as low as 0.04%

Metal fires and their implications for advanced reactors. Part 3: Experimental and modeling results

International Nuclear Information System (INIS)

Nowlen, Steven Patrick; Figueroa, Victor G.; Olivier, Tara Jean; Hewson, John C.; Blanchat, Thomas K.

2010-01-01

This report details the primary results of the Laboratory Directed Research and Development project (LDRD 08-0857) Metal Fires and Their Implications for Advance Reactors. Advanced reactors may employ liquid metal coolants, typically sodium, because of their many desirable qualities. This project addressed some of the significant challenges associated with the use of liquid metal coolants, primary among these being the extremely rapid oxidation (combustion) that occurs at the high operating temperatures in reactors. The project has identified a number of areas for which gaps existed in knowledge pertinent to reactor safety analyses. Experimental and analysis capabilities were developed in these areas to varying degrees. In conjunction with team participation in a DOE gap analysis panel, focus was on the oxidation of spilled sodium on thermally massive surfaces. These are spills onto surfaces that substantially cool the sodium during the oxidation process, and they are relevant because standard risk mitigation procedures seek to move spill environments into this regime through rapid draining of spilled sodium. While the spilled sodium is not quenched, the burning mode is different in that there is a transition to a smoldering mode that has not been comprehensively described previously. Prior work has described spilled sodium as a pool fire, but there is a crucial, experimentally-observed transition to a smoldering mode of oxidation. A series of experimental measurements have comprehensively described the thermal evolution of this type of sodium fire for the first time. A new physics-based model has been developed that also predicts the thermal evolution of this type of sodium fire for the first time. The model introduces smoldering oxidation through porous oxide layers to go beyond traditional pool fire analyses that have been carried out previously in order to predict experimentally observed trends. Combined, these developments add significantly to the safety

Self-expandable metal stent for palliation of malignant dysphagia & quality of life improvement in advanced cancer esophagus: Upper Egypt experience

OpenAIRE

Mohamed Abdelshafy; Mohammed A. Omar; Mohamed Abdel Bary; Mohamed Mostafa Wahaman; Rafaat Abd elaal Bakheet

2017-01-01

Background: In advanced cancer esophagus patients, self-expandable metallic stents (SEMS) are utilized to relieve malignant difficulty in swallowing and improve their quality of the life. Retrospectively, we evaluated the efficacy, feasibility, and outcomes of SEMS in palliation of malignant dysphagia in advanced cancer esophagus and its' complications. Methods: We retrospectively reviewed data of 350 patients with malignant dysphagia due to advanced cancer esophagus from December 2012 to ...

The miscibility and oxidation study of the simulated metallic spent fuel for the development of an advanced spent fuel management process

Energy Technology Data Exchange (ETDEWEB)

Shin, Y. J.; You, G. S.; Ju, J. S.; Lee, E. P.; Seo, H. S.; Ahn, S. B. [Korea Atomic Energy Research Institute, Taejeon (Korea)

1999-03-01

The simulated metallic spent fuel ingots were fabricated and evaluated the oxidation rates and the activation energies under several temperature conditions to develop an advanced spent fuel management process. It was also checked the immiscibility of the some elements with metal uranium. 2 refs., 45 figs. (Author)

Construction of stable Ta{sub 3}N{sub 5}/g-C{sub 3}N{sub 4} metal/non-metal nitride hybrids with enhanced visible-light photocatalysis

Energy Technology Data Exchange (ETDEWEB)

Jiang, Yinhua, E-mail: yms418@126.com [School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 2120013,PR China (China); Liu, Peipei; Chen, YeCheng; Zhou, Zhengzhong; Yang, Haijian [School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 2120013,PR China (China); Hong, Yuanzhi; Li, Fan; Ni, Liang [School of Materials Science and Engineering, Jiangsu University, Zhenjiang 2120013,PR China (China); Yan, Yongsheng [School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 2120013,PR China (China); Gregory, Duncan H, E-mail: duncan.gregory@glasgow.ac.uk [School of Chemistry, University of Glasgow, Glasgow G12 8QQ (United Kingdom)

2017-01-01

Highlights: • Novel Ta{sub 3}N{sub 5}/g-C{sub 3}N{sub 4} metal/non-metal nitride hybrids were synthesized. • The hybrid nitrides showed enhanced visible-light photocatalytic performance. • The Ta{sub 3}N{sub 5}/g-C{sub 3}N{sub 4} hybrid nitride exhibited excellent photostability. • The hole is the main photoactive specie for the degradation of RhB. - Abstract: In this paper, a novel Ta{sub 3}N{sub 5}/g-C{sub 3}N{sub 4} metal/non-metal nitride hybrid was successfully synthesized by a facile impregnation method. The photocatalytic activity of Ta{sub 3}N{sub 5}/g-C{sub 3}N{sub 4} hybrid nitrides was evaluated by the degradation of organic dye rhodamine B (RhB) under visible light irradiation, and the result indicated that all Ta{sub 3}N{sub 5}/g-C{sub 3}N{sub 4} samples exhibited distinctly enhanced photocatalytic activities for the degradation of RhB than pure g-C{sub 3}N{sub 4}. The optimal Ta{sub 3}N{sub 5}/g-C{sub 3}N{sub 4} composite sample, with Ta{sub 3}N{sub 5} mass ratio of 2%, demonstrated the highest photocatalytic activity, and its degradation rate constant was 2.71 times as high as that of pure g-C{sub 3}N{sub 4}. The enhanced photocatalytic activity of this Ta{sub 3}N{sub 5}/g-C{sub 3}N{sub 4} metal/metal-free nitride was predominantly attributed to the synergistic effect which increased visible-light absorption and facilitated the efficient separation of photoinduced electrons and holes. The Ta{sub 3}N{sub 5}/g-C{sub 3}N{sub 4} hybrid nitride exhibited excellent photostability and reusability. The possible mechanism for improved photocatalytic performance was proposed. Overall, this work may provide a facile way to synthesize the highly efficient metal/metal-free hybrid nitride photocatalysts with promising applications in environmental purification and energy conversion.

Recent Progress on Plasmon-Enhanced Fluorescence

Directory of Open Access Journals (Sweden)

Dong Jun

2015-12-01

Full Text Available The optically generated collective electron density waves on metal–dielectric boundaries known as surface plasmons have been of great scientific interest since their discovery. Being electromagnetic waves on gold or silver nanoparticle’s surface, localised surface plasmons (LSP can strongly enhance the electromagnetic field. These strong electromagnetic fields near the metal surfaces have been used in various applications like surface enhanced spectroscopy (SES, plasmonic lithography, plasmonic trapping of particles, and plasmonic catalysis. Resonant coupling of LSPs to fluorophore can strongly enhance the emission intensity, the angular distribution, and the polarisation of the emitted radiation and even the speed of radiative decay, which is so-called plasmon enhanced fluorescence (PEF. As a result, more and more reports on surface-enhanced fluorescence have appeared, such as SPASER-s, plasmon assisted lasing, single molecule fluorescence measurements, surface plasmoncoupled emission (SPCE in biological sensing, optical orbit designs etc. In this review, we focus on recent advanced reports on plasmon-enhanced fluorescence (PEF. First, the mechanism of PEF and early results of enhanced fluorescence observed by metal nanostructure will be introduced. Then, the enhanced substrates, including periodical and nonperiodical nanostructure, will be discussed and the most important factor of the spacer between molecule and surface and wavelength dependence on PEF is demonstrated. Finally, the recent progress of tipenhanced fluorescence and PEF from the rare-earth doped up-conversion (UC and down-conversion (DC nanoparticles (NPs are also commented upon. This review provides an introduction to fundamentals of PEF, illustrates the current progress in the design of metallic nanostructures for efficient fluorescence signal amplification that utilises propagating and localised surface plasmons.

Egg-Citing! Isolation of Protoporphyrin IX from Brown Eggshells and Its Detection by Optical Spectroscopy and Chemiluminescence

Science.gov (United States)

Dean, Michelle L.; Miller, Tyson A.; Bruckner, Christian

2011-01-01

A simple and cost-effective laboratory experiment is described that extracts protoporphyrin IX from brown eggshells. The porphyrin is characterized by UV-vis and fluorescence spectroscopy. A chemiluminescence reaction (peroxyoxalate ester fragmentation) is performed that emits light in the UV region. When the porphyrin extract is added as a fluor…

ADVANCED COMPRESSOR ENGINE CONTROLS TO ENHANCE OPERATION, RELIABILITY AND INTEGRITY

Energy Technology Data Exchange (ETDEWEB)

Gary D. Bourn; Jess W. Gingrich; Jack A. Smith

2004-03-01

This document is the final report for the ''Advanced Compressor Engine Controls to Enhance Operation, Reliability, and Integrity'' project. SwRI conducted this project for DOE in conjunction with Cooper Compression, under DOE contract number DE-FC26-03NT41859. This report addresses an investigation of engine controls for integral compressor engines and the development of control strategies that implement closed-loop NOX emissions feedback.

Chelant-enhanced heavy metals uptake by Eucalyptus trees under controlled deficit irrigation

Science.gov (United States)

Fine, Pinchas; Rathod, Paresh; Beriozkin, Anna; Ein-Gal, Oz; Hass, Amir

2014-05-01

Enhancement of phytoremediation of heavy metal polluted soils employs organic ligands, aimed to solubilize, phytoextract and translocate metals into the canopy. The use of more persistent chelants (e.g. EDTA) is phasing out due to concerns over their role in the environment. We tested the hypothesis that controlled deficit irrigation (CDI) of the fast growing, salinity resistant Eucalyptus camaldulensis coupled with timely EDTA application enhances sediment phytoremediation while minimizing leaching of metal complexes below the root-zone. This was tested in 220-L lysimeters packed with sand mixed with metals polluted biosolids. One year old trees were brought under CDI with tap or RO water for two growing seasons. EDTA, EDDS and citric acid fertigation at 2 mM started in each May for 2.5-3.5 months, and prescribed soil leaching and sampling of tree leaves started thereafter. While all 3 chelants solubilized biosolids metal in batch extraction (EDDS often being the more efficient), EDTA was the only to increased metal concentrations both in the soil solution and in the Eucalyptus leaves. The average concentrations in the soil solution and in the leaves, in the EDTA vs. control (chelant-free) treatments, all respectively, were: Cd - 200 mg L-1 vs. 1.0, and 67 vs. 21 mg kg-1; Cu: 90 vs. 1.5 mg L-1, and 17 vs. 3.0 mg kg-1; Cr: 4.0 vs. 1.4 mg L-1, and 3.0 vs. 1.0 mg kg-1; Ni: 60 mg L-1 vs. 14, and 20 vs. 6.0 mg kg-1; Pb: >44 vs. 0.1 mg L-1, and 9.0 vs. 1.0 mg kg-1; and Zn: 650 vs. 4.0 mg L-1 and 200 vs. 70 mg kg-1. While EDDS was undetectable in all the leachates, EDTA concentrated to up to 100 mM. At 10 mM soil solution concentration, EDDS half-life in acclimated lysimeter media was 5-11 days and that of EDTA was ≥27-d. The study suggests that sustainable phytostabilization and phytoextraction of heavy metals are achievable under CDI with EDTA augmentation at low dose. This was yet futile with the biodegradable EDDS and citric acid. CDI with RO water further widened

Application of Box–Behnken design in the optimization of new peroxyoxalate–H{sub 2}O{sub 2} chemiluminescence system using furan derivatives as blue activators

Energy Technology Data Exchange (ETDEWEB)

Chaichi, M.J., E-mail: jchaichi@yahoo.com [Faculty of Chemistry, Mazandaran University, Babolsar (Iran, Islamic Republic of); Azizi, S.N.; Alijanpour, O.; Heidarpour, M. [Faculty of Chemistry, Mazandaran University, Babolsar (Iran, Islamic Republic of); Qandalee, M. [Department of Biology, Garmsar Branch, Islamic Azad University, Garmsar (Iran, Islamic Republic of)

2013-06-15

The non-commercially synthesized and purified furan derivatives are of great interest as fluorescent emitters for peroxyoxalate chemiluminescence (PO-CL). The reaction of oxalic ester such as bis-(2,4,6-trichloro-phenyl) oxalate (TCPO) with H{sub 2}O{sub 2} can lead to the excitation of an appropriate activator via the formation of a 1,2-dioxetanedione intermediate. In this study, two furan derivatives were used as activators which produce a blue light in the chemiluminescence systems. In the following, the Box–Behnken design matrix and response surface methodology (RSM) have been applied to design the experiments to study the relationship between the chemiluminescence intensities and the three most important operating variables such as sodium salicylate (5×10{sup −4}–5×10{sup −3} M), furan (10{sup −5}–10{sup −3} M) and hydrogen peroxide (10{sup −3}–10{sup −1} M) concentrations, and also to evaluate the interactive effects of these variables on the CL emission of TCPO system. Totally 15 experiments were conducted in the present study towards the construction of a quadratic model. Independent variables of sodium salicylate, hydrogen peroxide and furan concentration have the significance value of p=0.05, in both the systems, which explicitly shows the importance of these variables in the CL emission of TCPO. Values of Prob>F less than 0.0001 indicated that the model terms are significant for the CL emission of TCPO. Moreover, the regression equation coefficients were calculated and the data fitted to a second-order polynomial equation for CL emission of TCPO. -- Highlights: ► Furan derivatives are used as activators for peroxyoxalate chemiluminescence. ► The activators produce a blue light in the chemiluminescence system. ► The Box–Behnken design matrix and response surface methodology (RSM) is used. ► The most important variables are sodium salicylate, furan and hydrogen peroxide. ► The data are fitted to a second-order polynomial

Transition Metal Phosphide Nanoparticles Supported on SBA-15 as Highly Selective Hydrodeoxygenation Catalysts for the Production of Advanced Biofuels.

Science.gov (United States)

Yang, Yongxing; Ochoa-Hernández, Cristina; de la Peña O'Shea, Víctor A; Pizarro, Patricia; Coronado, Juan M; Serrano, David P

2015-09-01

A series of catalysts constituted by nanoparticles of transition metal (M = Fe, Co, Ni and Mo) phosphides (TMP) dispersed on SBA-15 were synthesized by reduction of the corresponding metal phosphate precursors previously impregnated on the mesostructured support. All the samples contained a metal-loading of 20 wt% and with an initial M/P mole ratio of 1, and they were characterized by X-ray diffraction (XRD), N2 sorption, H2-TPR and transmission electron microscopy (TEM). Metal phosphide nanocatalysts were tested in a high pressure continuous flow reactor for the hydrodeoxygenation (HDO) of a methyl ester blend containing methyl oleate (C17H33-COO-CH3) as main component (70%). This mixture constitutes a convenient surrogate of triglycerides present in vegetable oils, and following catalytic hydrotreating yields mainly n-alkanes. The results of the catalytic assays indicate that Ni2P/SBA-15 catalyst presents the highest ester conversion, whereas the transformation rate is about 20% lower for MoP/SBA-15. In contrast, catalysts based on Fe and Co phosphides show a rather limited activity. Hydrocarbon distribution in the liquid product suggests that both hydrodeoxygenation and decarboxylation/decarbonylation reactions occur simultaneously over the different catalysts, although MoP/SBA-15 possess a selectivity towards hydrodeoxygenation exceeding 90%. Accordingly, the catalyst based on MoP affords the highest yield of n-octadecane, which is the preferred product in terms of carbon atom economy. Subsequently, in order to conjugate the advantages of both Ni and Mo phosphides, a series of catalysts containing variable proportions of both metals were prepared. The obtained results reveal that the mixed phosphides catalysts present a catalytic behavior intermediate between those of the monometallic phosphides. Accordingly, only marginal enhancement of the yield of n-octadecane is obtained for the catalysts with a Mo/Ni ratio of 3. Nevertheless, owing to this high selectivity

Safety aspects of the US advanced LMR [liquid metal reactor] design

International Nuclear Information System (INIS)

Pedersen, D.R.; Gyorey, G.L.; Marchaterre, J.F.; Rosen, S.

1989-01-01

The cornerstones of the United States Advanced Liquid Metal Cooled Reactor (ALMR) program sponsored by the Department of Energy are: the plant design program at General Electric based on the PRISM (Power Reactor Innovative Small Module) concept, and the Integral Fast Reactor program (IFR) at Argonne National Laboratory (ANL). The goal of the US program is to produce a standard, commercial ALMR, including the associated fuel cycle. This paper discusses the US regulatory framework for design of an ALMR, safety aspects of the IFR program at ANL, the IFR fuel cycle and actinide recycle, and the ALMR plant design program at GE. 6 refs., 5 figs

Angular-dependent photodetection enhancement by a metallic circular disk optical antenna

Directory of Open Access Journals (Sweden)

Thitikorn Kemsri

2017-02-01

Full Text Available In this paper, we analyze the plasmonic resonance excited by linearly polarized longwave infrared (LWIR plane waves in a metallic circular disk optical antenna (MCDA. The surface current distributions are simulated at different wavelengths, incident angles, and polarizations. The excited surface plasmonic resonance waves (SPRs are different from the Bessel-type of SPR modes and closely resemble those in a monopole antenna. An MCDA coupled LWIR quantum dot infrared photodetector (QDIP was fabricated and measured at different LWIR plane wave wavelengths and incident angles. A linear correlation between the enhancement ratio and the integrated square of the current is obtained, indicating the monopole antenna effect is a dominating factor for the plasmonic enhancement.

Chemiluminescent determination of vanadium(IV) using a cinchomeronic hydrazide-H2O2 system and flow injection analysis

International Nuclear Information System (INIS)

Pradana Perez, J.A.; Alegria, J.S. Durand; Hernando, P. Fernandez; Sierra, A. Narros

2005-01-01

This paper proposes a new chemiluminescent flow injection analysis (FIA) method for the determination of vanadium(IV) ions in aqueous media. The method is based on the chemiluminescent reaction that occurs between cinchomeronic hydrazide (CH) and hydrogen peroxide in a strongly alkaline medium, in which vanadium(IV) acts as a catalyst. The chemical and physical variables involved in the flow injection system are optimised using a modified simplex method. Vanadium ions can be detected in the 0.08 and 1.00 μg mL -1 range; the detection limit for a signal-to-noise ratio of 3 is 0.08 μg mL -1 . Great variations in the quantum yield were observed when cobalt(II), chromium(III), copper(II) and/or nickel(II) were present in the reaction medium. The proposed method is selective and simple, and can be successfully used to analyse water samples without the need for separation or preconcentration processes

The effect of dose enhancement near metal interfaces on synthetic diamond based X-ray dosimeters

Science.gov (United States)

Alamoudi, D.; Lohstroh, A.; Albarakaty, H.

2017-11-01

This study investigates the effects of dose enhancement on the photocurrent performance at metallic interfaces in synthetic diamond detectors based X-ray dosimeters as a function of bias voltages. Monte Carlo (MC) simulations with the BEAMnrc code were carried out to simulate the dose enhancement factor (DEF) and compared against the equivalent photocurrent ratio from experimental investigations. The MC simulation results show that the sensitive region for the absorbed dose distribution covers a few micrometers distances from the interface. Experimentally, two single crystals (SC) and one polycrystalline (PC) synthetic diamond samples were fabricated into detectors with carbon based electrodes by boron and carbon ion implantation. Subsequently; the samples were each mounted inside a tissue equivalent encapsulation to minimize unintended fluence perturbation. Dose enhancement was generated by placing copper, lead or gold near the active volume of the detectors using 50 kVp and 100 kVp X-rays relevant for medical dosimetry. The results show enhancement in the detectors' photocurrent performance when different metals are butted up to the diamond bulk as expected. The variation in the photocurrent measurement depends on the type of diamond samples, their electrodes' fabrication and the applied bias voltages indicating that the dose enhancement near the detector may modify their electronic performance.

Metal-free carbon materials-catalyzed sulfate radical-based advanced oxidation processes: A review on heterogeneous catalysts and applications.

Science.gov (United States)

Zhao, Qingxia; Mao, Qiming; Zhou, Yaoyu; Wei, Jianhong; Liu, Xiaocheng; Yang, Junying; Luo, Lin; Zhang, Jiachao; Chen, Hong; Chen, Hongbo; Tang, Lin

2017-12-01

In recent years, advanced oxidation processes (AOPs), especially sulfate radical based AOPs have been widely used in various fields of wastewater treatment due to their capability and adaptability in decontamination. Recently, metal-free carbon materials catalysts in sulfate radical production has been more and more concerned because these materials have been demonstrated to be promising alternatives to conventional metal-based catalysts, but the review of metal-free catalysts is rare. The present review outlines the current state of knowledge on the generation of sulfate radical using metal-free catalysts including carbon nanotubes, graphene, mesoporous carbon, activated carbon, activated carbon fiber, nanodiamond. The mechanism such as the radical pathway and non-radical pathway, and factors influencing of the activation of sulfate radical was also be revealed. Knowledge gaps and research needs have been identified, which include the perspectives on challenges related to metal-free catalyst, heterogeneous metal-free catalyst/persulfate systems and their potential in practical environmental remediation. Copyright © 2017 Elsevier Ltd. All rights reserved.

Tomosynthesis and contrast-enhanced digital mammography: recent advances in digital mammography

International Nuclear Information System (INIS)

Diekmann, Felix; Bick, Ulrich

2007-01-01

Digital mammography is more and more replacing conventional mammography. Initial concerns about an inferior image quality of digital mammography have been largely overcome and recent studies even show digital mammography to be superior in women with dense breasts, while at the same time reducing radiation exposure. Nevertheless, an important limitation of digital mammography remains: namely, the fact that summation may obscure lesions in dense breast tissue. However, digital mammography offers the option of so-called advanced applications, and two of these, contrast-enhanced mammography and tomosynthesis, are promising candidates for improving the detection of breast lesions otherwise obscured by the summation of dense tissue. Two techniques of contrast-enhanced mammography are available: temporal subtraction of images acquired before and after contrast administration and the so-called dual-energy technique, which means that pairs of low/high-energy images acquired after contrast administration are subtracted. Tomosynthesis on the other hand provides three-dimensional information on the breast. The images are acquired with different angulations of the X-ray tube while the object or detector is static. Various reconstruction algorithms can then be applied to the set of typically nine to 28 source images to reconstruct 1-mm slices with a reduced risk of obscuring pathology. Combinations of both advanced applications have only been investigated in individual experimental studies; more advanced software algorithms and CAD systems are still in their infancy and have only undergone preliminary clinical evaluation. (orig.)

A Metal Fuel Core Concept for 1000 MWt Advanced Burner Reactor

International Nuclear Information System (INIS)

Yang, W.S.; Kim, T.K.; Grandy, C.

2007-01-01

This paper describes the core design and performance characteristics of a metal fuel core concept for a 1000 MWt Advanced Burner Reactor. A ternary metal fuel form of U-TRU-Zr was assumed with weapons grade plutonium feed for the startup core and TRU recovered from LWR spent fuel for the recycled equilibrium core. A compact burner core was developed by trade-off between the burnup reactivity loss and TRU conversion ratio, with a fixed cycle length of one-year. In the startup core, the average TRU enrichment is 15.5%, the TRU conversion ratio is 0.81, and the burnup reactivity loss over a cycle is 3.6% Δk. The heavy metal and TRU inventories are 13.1 and 2.0 metric tons, respectively. The average discharge burnup is 93 MWd/kg, and the TRU consumption rate is 55.5 kg/year. For the recycled equilibrium core, the average TRU enrichment is 22.1 %, the TRU conversion ratio is 0.73, and the burnup reactivity loss is 2.2% Δk. The TRU inventory and consumption rate are 2.9 metric tons and 81.6 kg/year, respectively. The evaluated reactivity coefficients provide sufficient negative feedbacks. The control systems provide shutdown margins that are more than adequate. The integral reactivity parameters for quasi-static reactivity balance analysis indicate favorable passive safety features, although detailed safety analyses are required to verify passive safety behavior. (authors)

Fresh organic matter of municipal solid waste enhances phytoextraction of heavy metals from contaminated soil

Energy Technology Data Exchange (ETDEWEB)

Salati, S.; Quadri, G.; Tambone, F. [Dipartimento di Produzione Vegetale, Universita degli Studi di Milano, Via Celoria 2, 20133 Milano (Italy); Adani, F., E-mail: fabrizio.adani@unimi.i [Dipartimento di Produzione Vegetale, Universita degli Studi di Milano, Via Celoria 2, 20133 Milano (Italy)

2010-05-15

In this study, the ability of the organic fraction of municipal solid wastes (OFMSW) to enhance heavy metal uptake of maize shoots compared with ethylenediamine disuccinic acid (EDDS) was tested on soil contaminated with heavy metals. Soils treated with OFMSW and EDDS significantly increased the concentration of heavy metals in maize shoots (increments of 302%, 66%, 184%, 169%, and 23% for Cr, Cu, Ni, Zn, and Pb with respect to the control and increments of 933%, 482%, 928%, 428%, and 5551% for soils treated with OFMSW and EDDS, respectively). In soil treated with OFMSW, metal uptake was favored because of the high presence of dissolved organic matter (DOM) (41.6x than soil control) that exhibited ligand properties because of the high presence of carboxylic acids. Because of the toxic effect of EDDS on maize plants, soil treated with OFMSW achieved the highest extraction of total heavy metals. - Organic fraction of MSW affects the bioavailability of heavy metals in soil.

Fresh organic matter of municipal solid waste enhances phytoextraction of heavy metals from contaminated soil

International Nuclear Information System (INIS)

Salati, S.; Quadri, G.; Tambone, F.; Adani, F.

2010-01-01

In this study, the ability of the organic fraction of municipal solid wastes (OFMSW) to enhance heavy metal uptake of maize shoots compared with ethylenediamine disuccinic acid (EDDS) was tested on soil contaminated with heavy metals. Soils treated with OFMSW and EDDS significantly increased the concentration of heavy metals in maize shoots (increments of 302%, 66%, 184%, 169%, and 23% for Cr, Cu, Ni, Zn, and Pb with respect to the control and increments of 933%, 482%, 928%, 428%, and 5551% for soils treated with OFMSW and EDDS, respectively). In soil treated with OFMSW, metal uptake was favored because of the high presence of dissolved organic matter (DOM) (41.6x than soil control) that exhibited ligand properties because of the high presence of carboxylic acids. Because of the toxic effect of EDDS on maize plants, soil treated with OFMSW achieved the highest extraction of total heavy metals. - Organic fraction of MSW affects the bioavailability of heavy metals in soil.

EVALUATION OF FERRIC CHLORIDE AND ALUM EFFICIENCIES IN ENHANCED COAGULATION FOR TOC REMOVAL AND RELATED RESIDUAL METAL CONCENTRATIONS

Directory of Open Access Journals (Sweden)

A. Mesdaghinia, M. T. Rafiee, F. Vaezi and A. H. Mahvi

2005-07-01

Full Text Available Although the removal of colloidal particles continues to be an important reason for using coagulation, a newer objective, the removal of natural organic matter (NOM to reduce the formation of disinfection by-products (DBPs, is growing in importance. Enhanced coagulation is thus introduced to most water utilities treating surface water. Bench-scale experiments were conducted to compare the effectiveness of alum and ferric chloride in removing DBPs precursors from eight synthetic water samples, each representing a different element of the USEPA’s 3×3 enhanced coagulation matrix. The effect of enhanced coagulation on the residual metal (aluminum/iron concentration in the treated water was assessed as well. The removal of total organic carbon (TOC was dependent on the coagulant type and was enhanced with increasing coagulant dose, but the latter had no further considerable effect in case of increasing to high levels. For all the treated samples coagulation with ferric chloride proved to be more effective than alum at similar doses and the mean values of treatment efficiencies were 51% and 32% for ferric chloride and alum, respectively. Ferric chloride was therefore considered the better chemical for enhancing the coagulation process. Besides, due to less production of sludge by this coagulant, it would be predicted that treatment plants would be confronted to fewer problems with respect to final sludge disposal. Measurements of residual metal in treated water indicated that iron and aluminum concentrations had been increased as expected but the quality of water concerning the residual metal deteriorated much more in cases of under-dosing. Despite expecting high residual Al and Fe concentrations under enhanced coagulation, metal concentrations were frequently remained low and were not increased appreciably.

Low Loss Advanced Metallic Fuel Casting Evaluation

International Nuclear Information System (INIS)

Kim, Kihwan; Ko, Youngmo; Kim, Jonghwan; Song, Hoon; Lee Chanbock

2014-01-01

The fabrication process for SFR fuel is composed of fuel slug casting, loading and fabrication of the fuel rods, and the fabrication of the final fuel assemblies. Fuel slug casting is the dominant source of fuel losses and recycles streams in the fabrication process. Recycle streams include fuel slug reworks, returned scraps, and fuel casting heels, which are a special concern in the counter gravity injection casting process because of the large masses involved. Large recycle and waste streams result in lowering the productivity and the economic efficiency of fuel production. To increase efficiency the fuel losses in the furnace chamber, crucible, and the mold, after casting a considerable amount of fuel alloy in the casting furnace, will be quantitatively evaluated. After evaluation the losses will be identified and minimized. It is expected that this study will contribute to the minimization of fuel losses and the wastes streams in the fabrication process of the fuel slugs. Also through this study the technical readiness level of the metallic fuel fabrication process will be further enhanced. In this study, U-Zr alloy system fuel slugs were fabricated by a gravity casting method. Metallic fuel slugs were successfully fabricated with 19 slugs/batch with diameter of 5mm and length of 300mm. Fuel losses was quantitatively evaluated in casting process for the fuel slugs. Fuel losses of the fuel slugs were so low, 0.1∼1.0%. Injection casting experiments have been performed to reduce the fuel loss and improve the casting method. U-Zr fuel slug having φ5.4-L250mm was soundly fabricated with 0.1% in fuel loss. The fuel losses could be minimized to 0.1%, which showed that casting technology of fuel slugs can be a feasible approach to reach the goal of the fuel losses of 0.1% or less in commercial scale

Summary of advanced LMR [Liquid Metal Reactor] evaluations: PRISM [Power Reactor Inherently Safe Module] and SAFR [Sodium Advanced Fast Reactor

International Nuclear Information System (INIS)

Van Tuyle, G.J.; Slovik, G.C.; Chan, B.C.; Kennett, R.J.; Cheng, H.S.; Kroeger, P.G.

1989-10-01

In support of the US Nuclear Regulatory Commission (NRC), Brookhaven National Laboratory (BNL) has performed independent analyses of two advanced Liquid Metal Reactor (LMR) concepts. The designs, sponsored by the US Department of Energy (DOE), the Power Reactor Inherently Safe Module (PRISM) [Berglund, 1987] and the Sodium Advanced Fast Reactor (SAFR) [Baumeister, 1987], were developed primarily by General Electric (GE) and Rockwell International (RI), respectively. Technical support was provided to DOE, RI, and GE, by the Argonne National Laboratory (ANL), particularly with respect to the characteristics of the metal fuels. There are several examples in both PRISM and SAFR where inherent or passive systems provide for a safe response to off-normal conditions. This is in contrast to the engineered safety systems utilized on current US Light Water Reactor (LWR) designs. One important design inherency in the LMRs is the ''inherent shutdown'', which refers to the tendency of the reactor to transition to a much lower power level whenever temperatures rise significantly. This type of behavior was demonstrated in a series of unscrammed tests at EBR-II [NED, 1986]. The second key design feature is the passive air cooling of the vessel to remove decay heat. These systems, designated RVACS in PRISM and RACS in SAFR, always operate and are believed to be able to prevent core damage in the event that no other means of heat removal is available. 27 refs., 78 figs., 3 tabs

Enhanced Raman scattering assisted by ultrahigh order modes of the double metal cladding waveguide

Energy Technology Data Exchange (ETDEWEB)

Xu, Tian; Huang, Liming; Jin, Yonglong; Fang, Jinghuai, E-mail: cyin.phys@gmail.com, E-mail: fjhuai@ntu.edu.cn [Physics Department, Nantong University, No. 9, Seyuan Road, Nantong, Jiangsu 226007 (China); Yin, Cheng, E-mail: cyin.phys@gmail.com, E-mail: fjhuai@ntu.edu.cn [Jiangsu Key Laboratory of Power Transmission and Distribution Equipment Technology, Hohai University, Changzhou 213022 (China); Huang, Meizhen [Department of Instrument Science and Engineering, Shanghai Jiaotong University, No. 800, DongChuan Road, Shanghai 200240 (China)

2014-10-20

Distinguished from the usual strategy to enhance the Raman scattering such as creating hot spots in the surface-enhanced Raman scattering, this paper takes a quite different approach based on the double metal cladding waveguide. The target analyte is located in the guiding layer of sub-millimeter scale, where several ultrahigh order modes with high intensity are simultaneously excited via a focused laser beam. The experimental setup is simple, and both simulation and experimental results confirm the enhancement mechanism of these oscillating modes. Other appealing features include the large detection area and the ability to excite guided modes via both polarizations. This scheme can be applied to large molecules detection and readily integrated with other Raman enhancement techniques.

Effects of optical diagnostic techniques on the accuracy of laminar flame speeds measured from Bunsen flames: OH* chemiluminescence, OH-PLIF and acetone/kerosene-PLIF

Science.gov (United States)

Wu, Yi; Modica, Vincent; Yu, Xilong; Li, Fei; Grisch, Frédéric

2018-01-01

The effects of optical diagnostic techniques on the accuracy of laminar flame speed measured from Bunsen flames were investigated. Laminar flame speed measurements were conducted for different fuel/air mixtures including CH4/air, acetone/air and kerosene (Jet A-1)/air in applying different optical diagnostic techniques, i.e. OH* chemiluminescence, OH-PLIF and acetone/kerosene-PLIF. It is found that the OH* chemiluminescence imaging technique cannot directly derive the location of the outer edge of the fresh gases and it is necessary to correct the position of the OH* peak to guarantee the accuracy of the measurements. OH-PLIF and acetone/kerosene-PLIF respectively are able to measure the disappearance of the fresh gas contour and the appearance of the reaction zone. It shows that the aromatic-PLIF technique gives similar laminar flame speed values when compared with those obtained from corrected OH* chemiluminescence images. However, discrepancies were observed between the OH-PLIF and the aromatic-PLIF techniques, in that OH-PLIF slightly underestimates laminar flame speeds by up to 5%. The difference between the flame contours obtained from different optical techniques are further analysed and illustrated with 1D flame structure simulation using detailed kinetic mechanisms.

Effects of Non-Equilibrium Plasmas on Low-Pressure, Premixed Flames. Part 1: CH* Chemiluminescence, Temperature, and OH

Science.gov (United States)

2018-01-16

Adamovich, Jeffrey A. Sutton1 Department of Mechanical and Aerospace Engineering , Ohio State University Abstract In this paper, we... chemistry . Qualitative imaging of CH* chemiluminescence indicates that during plasma discharge, the luminous flame zone is shifted upstream towards...Sutton Department of Mechanical and Aerospace Engineering , Ohio State University 1. Introduction In recent years, considerable interest has

Chemiluminescence of graphene quantum dots and its application to the determination of uric acid

International Nuclear Information System (INIS)

Amjadi, Mohammad; Manzoori, Jamshid L.; Hallaj, Tooba

2014-01-01

We report on the chemiluminescence (CL) of graphene quantum dots (GQDs) induced by direct chemical oxidation. GQDs were prepared by a simple carbonization method and characterized by X-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy and Raman spectroscopy. It was found that Ce(IV) could oxidize GQDs to produce a relatively intense CL emission. The mechanism of CL generation was investigated based on the fluorescence and CL emission spectra. It was attributed to the radiative recombination of oxidant-injected holes and thermally excited electrons in the GQDs. In order to show the analytical application potential of GQDs-Ce(IV) CL system, it was applied to the determination of uric acid. Under the optimized conditions, the proposed CL system exhibited excellent analytical performance for determination of uric acid in the range of 1.0×10 −6 M–5.0×10 −4 M with a limit of detection of 5.0×10 −7 M. The method was applied to the determination of uric acid in human plasma and urine samples, with satisfactory results. - Highlights: • Chemiluminescence of graphene quantum dots by direct oxidation was studied. • Intense CL is produced by reaction of graphene quantum dots with Ce(IV). • The new CL system was applied to determination of uric acid in plasma and urine

Chemiluminescence of graphene quantum dots and its application to the determination of uric acid

Energy Technology Data Exchange (ETDEWEB)

Amjadi, Mohammad, E-mail: amjadi@tabrizu.ac.ir; Manzoori, Jamshid L.; Hallaj, Tooba

2014-09-15

We report on the chemiluminescence (CL) of graphene quantum dots (GQDs) induced by direct chemical oxidation. GQDs were prepared by a simple carbonization method and characterized by X-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy and Raman spectroscopy. It was found that Ce(IV) could oxidize GQDs to produce a relatively intense CL emission. The mechanism of CL generation was investigated based on the fluorescence and CL emission spectra. It was attributed to the radiative recombination of oxidant-injected holes and thermally excited electrons in the GQDs. In order to show the analytical application potential of GQDs-Ce(IV) CL system, it was applied to the determination of uric acid. Under the optimized conditions, the proposed CL system exhibited excellent analytical performance for determination of uric acid in the range of 1.0×10{sup −6} M–5.0×10{sup −4} M with a limit of detection of 5.0×10{sup −7} M. The method was applied to the determination of uric acid in human plasma and urine samples, with satisfactory results. - Highlights: • Chemiluminescence of graphene quantum dots by direct oxidation was studied. • Intense CL is produced by reaction of graphene quantum dots with Ce(IV). • The new CL system was applied to determination of uric acid in plasma and urine.

Sinonasal metallic foreign body penetration of the anterior cranial fossa

Directory of Open Access Journals (Sweden)

Madeleine B. Samuelson

2017-03-01

Conclusion: Intracranial metallic foreign bodies may have significant potential morbidity. Recent advances in endonasal techniques for anterior skull base access may enhance outcomes through reduced morbidity and mortality, improved speed and precision, shorter hospital stays, and lower post-operative pain [1,2,4]. Technical nuances of these approaches and medical decision-making in the context of various neurosurgical considerations are discussed.

Red mud (RM)-Induced enhancement of iron plaque formation reduces arsenic and metal accumulation in two wetland plant species.

Science.gov (United States)

Yang, J X; Guo, Q J; Yang, J; Zhou, X Y; Ren, H Y; Zhang, H Z; Xu, R X; Wang, X D; Peters, M; Zhu, G X; Wei, R F; Tian, L Y; Han, X K

2016-01-01

Human activities have resulted in arsenic (As) and heavy metals accumulation in paddy soils in China. Phytoremediation has been suggested as an effective and low-cost method to clean up contaminated soils. A combined soil-sand pot experiment was conducted to investigate the influence of red mud (RM) supply on iron plaque formation and As and heavy metal accumulation in two wetland plant species (Cyperus alternifolius Rottb., Echinodorus amazonicus Rataj), using As and heavy metals polluted paddy soil combined with three rates of RM application (0, 2%, 5%). The results showed that RM supply significantly decreased As and heavy metals accumulation in shoots of the two plants due to the decrease of As and heavy metal availability and the enhancement of the formation of iron plaque on the root surface and in the rhizosphere. Both wetland plants supplied with RM tended to have more Fe plaque, higher As and heavy metals on roots and in their rhizospheres, and were more tolerant of As and heavy metal toxicity. The results suggest that RM-induced enhancement of the formation of iron plaque on the root surface and in the rhizosphere of wetland plants may be significant for remediation of soils contaminated with As and heavy metals.

FAA/NASA International Symposium on Advanced Structural Integrity Methods for Airframe Durability and Damage Tolerance, part 2

Science.gov (United States)

Harris, Charles E. (Editor)

1994-01-01

The international technical experts in the areas of durability and damage tolerance of metallic airframe structures were assembled to present and discuss recent research findings and the development of advanced design and analysis methods, structural concepts, and advanced materials. The principal focus of the symposium was on the dissemination of new knowledge and the peer-review of progress on the development of advanced methodologies. Papers were presented on the following topics: structural concepts for enhanced durability, damage tolerance, and maintainability; new metallic alloys and processing technology; fatigue crack initiation and small crack effects; fatigue crack growth models; fracture mechanics failure criteria for ductile materials; structural mechanics methodology for residual strength and life prediction; development of flight load spectra for design and testing; and corrosion resistance.

SPECTROSCOPIC STUDIES OF EXTREMELY METAL-POOR STARS WITH THE SUBARU HIGH DISPERSION SPECTROGRAPH. V. THE Zn-ENHANCED METAL-POOR STAR BS 16920-017

International Nuclear Information System (INIS)

Honda, Satoshi; Aoki, Wako; Beers, Timothy C.; Takada-Hidai, Masahide

2011-01-01

We report Zn abundances for 18 very metal-poor stars studied in our previous work, covering the metallicity range -3.2< [Fe/H] <-2.5. The [Zn/Fe] values of most stars show an increasing trend with decreasing [Fe/H] in this metallicity range, confirming the results found by previous studies. However, the extremely metal-poor star BS 16920-017([Fe/H] =-3.2) exhibits a significantly high [Zn/Fe] ratio ([Zn/Fe] = +1.0). Comparison of the chemical abundances of this object with HD 4306, which has similar atmospheric parameters to BS 16920-017, clearly demonstrates a deficiency of α elements and neutron-capture elements in this star, along with enhancements of Mn and Ni, as well as Zn. The association with a hypernova explosion that has been proposed to explain the high Zn abundance ratios found in extremely metal-poor stars is a possible explanation, although further studies are required to fully interpret the abundance pattern of this object.

Sonochemical fabrication of 8-hydroxyquinoline aluminum (Alq3) nanoflowers with high electrogenerated chemiluminescence.

Science.gov (United States)

Mao, Chang-Jie; Wang, Dan-Chen; Pan, Hong-Cheng; Zhu, Jun-Jie

2011-03-01

Well-defined Alq(3) nanoflowers were fabricated via a facile and fast sonochemical route. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), field-emission scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to characterize the structure and shape of the as-prepared product. The results showed that the resulting Alq(3) was composed of nanobelts with thickness about 50 nm, average widths of 200 nm, and length up to 10 μm. The Alq(3) nanoflowers exhibited good electrogenerated chemiluminescence behavior. Copyright © 2010 Elsevier B.V. All rights reserved.

Flow-injection system for automated dissolution testing of isoniazid tablets with chemiluminescence detection.

Science.gov (United States)

Li, B; Zhang, Z; Liu, W

2001-05-30

A simple and sensitive flow-injection chemiluminescence (CL) system for automated dissolution testing is described and evaluated for monitoring of dissolution profiles of isoniazid tablets. The undissolved suspended particles in the dissolved solution were eliminated via on-line filter. The novel CL system of KIO(4)-isoniazid was also investigated. The sampling frequency of the system was 120 h(-1). The dissolution profiles of isoniazid fast-release tablets from three sources were determined, which demonstrates the stability, great sensitivity, large dynamic measuring range and robustness of the system.

Enhanced Natural Convection in a Metal Layer Cooled by Boiling Water

International Nuclear Information System (INIS)

Cho, Jae-Seon; Suh, Kune Y.; Chung, Chang-Hyun; Park, Rae-Joon; Kim, Sang-Baik

2004-01-01

An experimental study is performed to investigate the natural convection heat transfer characteristics and the solidification of the molten metal pool concurrently with forced convective boiling of the overlying coolant to simulate a severe accident in a nuclear power plant. The relationship between the Nusselt number (Nu) and the Rayleigh number (Ra) in the molten metal pool region is determined and compared with the correlations in the literature and experimental data with subcooled water. Given the same Ra condition, the present experimental results for Nu of the liquid metal pool with coolant boiling are found to be higher than those predicted by the existing correlations or measured from the experiment with subcooled boiling. To quantify the observed effect of the external cooling on the natural convection heat transfer rate from the molten pool, it is proposed to include an additional dimensionless group characterizing the temperature gradients in the molten pool and in the external coolant region. Starting from the Globe and Dropkin correlation, engineering correlations are developed for the enhancement of heat transfer in the molten metal pool when cooled by an overlying coolant. The new correlations for predicting natural convection heat transfer are applicable to low-Prandtl-number (Pr) materials that are heated from below and solidified by the external coolant above. Results from this study may be used to modify the current model in severe accident analysis codes

Advancements in solar stills for enhanced flow rate

Science.gov (United States)

Mishra, Sourav; Dubey, Maneesh; Raghuwanshi, Jitendra; Sharma, Vipin

2018-05-01

All over the world there is a scarcity of water and it is difficult to access potable water. Due to this most of the people are affected by diseases that are caused due to drinking of polluted water. There are technologies through which we can purify polluted water but the only problem is these technologies uses electrical energy. Since solar energy is abundant in nature therefore we can use solar as an energy source in solar stills for water distillation. Solar stills can be used in village areas where there is no electricity. It is simple and also economic in construction. This article addresses advancement in solar distillation and usage of nanofluids for enhancement in flow rate.

Determination of neurotransmitters and their metabolites using one- and two-dimensional liquid chromatography with acidic potassium permanganate chemiluminescence detection.

Science.gov (United States)

Holland, Brendan J; Conlan, Xavier A; Stevenson, Paul G; Tye, Susannah; Reker, Ashlie; Barnett, Neil W; Adcock, Jacqui L; Francis, Paul S

2014-09-01

High-performance liquid chromatography with chemiluminescence detection based on the reaction with acidic potassium permanganate and formaldehyde was explored for the determination of neurotransmitters and their metabolites. The neurotransmitters norepinephrine and dopamine were quantified in the left and right hemispheres of rat hippocampus, nucleus accumbens and prefrontal cortex, and the metabolites vanillylmandelic acid, 3,4-dihydrophenylacetic acid, 5-hydroxyindole-3-acetic acid and homovanillic acid were identified in human urine. Under optimised chemiluminescence reagent conditions, the limits of detection for these analytes ranged from 2.5 × 10(-8) to 2.5 × 10(-7) M. For the determination of neurotransmitter metabolites in urine, a two-dimensional high-performance liquid chromatography (2D-HPLC) separation operated in heart-cutting mode was developed to overcome the peak capacity limitations of the one-dimensional separation. This approach provided the greater separation power of 2D-HPLC with analysis times comparable to conventional one-dimensional separations.

Enhanced Laser Cooling of Rare-Earth-Ion-Doped Glass Containing Nanometer-Sized Metallic Particles

International Nuclear Information System (INIS)

Jia Youhua; Zhong Biao; Yin Jianping

2009-01-01

The enhanced laser cooling performance of rare-earth-ions-doped glasses containing small particles is predicted. This is achieved by the enhancement of local field around rare earth ions, owing to the surface plasmon resonance of small metallic particles. The role of energy transfer between ions and the particle is theoretical discussed. Depending on the particle size and the ion emission quantum efficiency, the enhancement of the absorption and the fluorescence is predicted. Moreover, taking Yb 3+ -doped ZBLAN as example, the cooling power and heat-light converting efficiency are calculated. It is finally concluded that the absorption and the fluorescence are greatly enhanced in these composite materials, the cooling power is increased compared to the bulk material. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

TREATMENT OF METAL-LADEN HAZARDOUS WASTES WITH ADVANCED CLEAN COAL TECHNOLOGY BY-PRODUCTS

Energy Technology Data Exchange (ETDEWEB)

James T. Cobb, Jr.; Ronald D. Neufeld; Jana Agostini

1999-06-01

This sixteenth quarterly report describes work done during the sixteenth three-month period of the University of Pittsburgh's project on the ''Treatment of Metal-Laden Hazardous Wastes with Advanced Clean Coal Technology By-Products.'' This report describes the activities of the project team during the reporting period. The principal work has focused upon new laboratory evaluation of samples from Phase 1, discussions with MAX Environmental Technologies, Inc., on the field work of Phase 2, giving a presentation, and making and responding to several outside contacts.

Treatment of metal-laden hazardous wastes with advanced Clean Coal Technology by-products

Energy Technology Data Exchange (ETDEWEB)

James T. Cobb, Jr.; Ronald D. Neufeld; Jana Agostini

1999-04-12

This twelfth quarterly report describes work done during the twelfth three-month period of the University of Pittsburgh's project on the ``Treatment of Metal-Laden Hazardous Wastes with Advanced Clean Coal Technology By-Products.'' This report describes the activities of the project team during the reporting period. The principal work has focused upon new laboratory evaluation of samples from Phase 1, discussions with MAX Environmental Technologies, Inc., on the field work of Phase 2, preparing and giving presentations, and making and responding to a number of outside contacts.

TREATMENT OF METAL-LADEN HAZARDOUS WASTES WITH ADVANCED CLEAN COAL TECHNOLOGY BY-PRODUCTS

Energy Technology Data Exchange (ETDEWEB)

James T. Cobb, Jr.; Ronald D. Neufeld; Jana Agostini

1999-01-01

This seventeenth quarterly report describes work done during the seventeenth three-month period of the University of Pittsburgh's project on the ''Treatment of Metal-Laden Hazardous Wastes with Advanced Clean Coal Technology By-Products.'' This report describes the activities of the project team during the reporting period. The principal work has focused upon new laboratory evaluation of samples from Phase 1, discussions with MAX Environmental Technologies, Inc., on the field work of Phase 2, giving a presentation, submitting a manuscript and making and responding to one outside contact.

TREATMENT OF METAL-LADEN HAZARDOUS WASTES WITH ADVANCED CLEAN COAL TECHNOLOGY BY-PRODUCTS

Energy Technology Data Exchange (ETDEWEB)

James T. Cobb, Jr.; Ronald D. Neufeld; Jana Agostini

1999-05-11

This fifteenth quarterly report describes work done during the fifteenth three-month period of the University of Pittsburgh's project on the ''Treatment of Metal-Laden Hazardous Wastes with Advanced Clean Coal Technology By-Products.'' This report describes the activities of the project team during the reporting period. The principal work has focused upon new laboratory evaluation of samples from Phase 1, discussions with MAX Environmental Technologies, Inc., on the field work of Phase 2, preparing and giving presentations, and making and responding to several outside contacts.

TREATMENT OF METAL-LADEN HAZARDOUS WASTES WITH ADVANCED CLEAN COAL TECHNOLOGY BY-PRODUCTS

Energy Technology Data Exchange (ETDEWEB)

James T. Cobb, Jr.; Ronald D. Neufeld; Jana Agostini

1999-05-10

This fourteenth quarterly report describes work done during the fourteenth three-month period of the University of Pittsburgh's project on the ''Treatment of Metal-Laden Hazardous Wastes with Advanced Clean Coal Technology By-Products.'' This report describes the activities of the project team during the reporting period. The principal work has focused upon new laboratory evaluation of samples from Phase 1, discussions with MAX Environmental Technologies, Inc., on the field work of Phase 2, preparing presentations, and making and responding to two outside contacts.

Tunable enhanced optical absorption of graphene using plasmonic perfect absorbers

Energy Technology Data Exchange (ETDEWEB)

Cai, Yijun [Institute of Optoelectronic Technology, Department of Electronic Engineering, Xiamen University, Xiamen 361005 (China); Institute of Electromagnetics and Acoustics, Department of Electronic Science, Xiamen University, Xiamen 361005 (China); Zhu, Jinfeng, E-mail: nanoantenna@hotmail.com [Institute of Electromagnetics and Acoustics, Department of Electronic Science, Xiamen University, Xiamen 361005 (China); Liu, Qing Huo [Department of Electrical and Computer Engineering, Duke University, Durham, North Carolina 27708 (United States)

2015-01-26

Enhancement and manipulation of light absorption in graphene is a significant issue for applications of graphene-based optoelectronic devices. In order to achieve this purpose in the visible region, we demonstrate a design of a graphene optical absorber inspired by metal-dielectric-metal metamaterial for perfect absorption of electromagnetic waves. The optical absorbance ratios of single and three atomic layer graphene are enhanced up to 37.5% and 64.8%, respectively. The graphene absorber shows polarization-dependence and tolerates a wide range of incident angles. Furthermore, the peak position and bandwidth of graphene absorption spectra are tunable in a wide wavelength range through a specific structural configuration. These results imply that graphene in combination with plasmonic perfect absorbers have a promising potential for developing advanced nanophotonic devices.

Fresh organic matter of municipal solid waste enhances phytoextraction of heavy metals from contaminated soil.

Science.gov (United States)

Salati, S; Quadri, G; Tambone, F; Adani, F

2010-05-01

In this study, the ability of the organic fraction of municipal solid wastes (OFMSW) to enhance heavy metal uptake of maize shoots compared with ethylenediamine disuccinic acid (EDDS) was tested on soil contaminated with heavy metals. Soils treated with OFMSW and EDDS significantly increased the concentration of heavy metals in maize shoots (increments of 302%, 66%, 184%, 169%, and 23% for Cr, Cu, Ni, Zn, and Pb with respect to the control and increments of 933%, 482%, 928%, 428%, and 5551% for soils treated with OFMSW and EDDS, respectively). In soil treated with OFMSW, metal uptake was favored because of the high presence of dissolved organic matter (DOM) (41.6x than soil control) that exhibited ligand properties because of the high presence of carboxylic acids. Because of the toxic effect of EDDS on maize plants, soil treated with OFMSW achieved the highest extraction of total heavy metals. Copyright 2009 Elsevier Ltd. All rights reserved.

CHEMICAL ANALYSIS OF A CARBON-ENHANCED VERY METAL-POOR STAR: CD-27 14351

Energy Technology Data Exchange (ETDEWEB)

Karinkuzhi, Drisya; Goswami, Aruna [Indian Institute of Astrophysics, Koramangala, Bangalore 560034 (India); Masseron, Thomas [Institute of Astronomy, Madingley Road, Cambridge CB3 0HA (United Kingdom)

2017-01-01

We present, for the first time, an abundance analysis of a very metal-poor carbon-enhanced star CD-27 14351 based on a high-resolution ( R  ∼ 48,000) FEROS spectrum. Our abundance analysis performed using local thermodynamic equilibrium model atmospheres shows that the object is a cool star with stellar atmospheric parameters, effective temperature T {sub eff} = 4335 K, surface gravity log g  = 0.5, microturbulence ξ  = 2.42 km s{sup −1}, and metallicity [Fe/H] = −2.6. The star exhibits high carbon and nitrogen abundances with [C/Fe] = 2.89 and [N/Fe] = 1.89. Overabundances of neutron-capture elements are evident in Ba, La, Ce, and Nd, with estimated [X/Fe] > 1, the largest enhancement being seen in Ce with [Ce/Fe] = 2.63. While the first peak s -process elements Sr and Y are found to be enhanced with respect to Fe, ([Sr/Fe] = 1.73 and [Y/Fe] = 1.91), the third peak s -process element Pb could not be detected in our spectrum at the given resolution. Europium, primarily an r -process element also shows an enhancement with [Eu/Fe] = 1.65. With [Ba/Eu] = 0.12, the object CD-27 14351 satisfies the classification criterion for a CEMP-r/s star. The elemental abundance distributions observed in this star are discussed in light of the chemical abundances observed in other CEMP stars in the literature.

Comparison of EDTA and EDDS as potential soil amendments for enhanced phytoextraction of heavy metals.

Science.gov (United States)

Meers, E; Ruttens, A; Hopgood, M J; Samson, D; Tack, F M G

2005-02-01

Phytoextraction has been proposed as an alternative remediation technology for soils polluted with heavy metals or radionuclides, but is generally conceived as too slow working. Enhancing the accumulation of trace pollutants in harvestable plant tissues is a prerequisite for the technology to be practically applicable. The chelating aminopolycarboxylic acid, ethylene diamine tetraacetate (EDTA), has been found to enhance shoot accumulation of heavy metals. However, the use of EDTA in phytoextraction may not be suitable due to its high environmental persistence, which may lead to groundwater contamination. This paper aims to assess whether ethylene diamine disuccinate (EDDS), a biodegradable chelator, can be used for enhanced phytoextraction purposes. A laboratory experiment was conducted to examine mobilisation of Cd, Cu, Cr, Ni, Pb and Zn into the soil solution upon application of EDTA or EDDS. The longevity of the induced mobilisation was monitored for a period of 40 days after application. Estimated effect half lives ranged between 3.8 and 7.5 days for EDDS, depending on the applied dose. The minimum observed effect half life of EDTA was 36 days, while for the highest applied dose no decrease was observed throughout the 40 day period of the mobilisation experiment. Performance of EDTA and EDDS for phytoextraction was evaluated by application to Helianthus annuus. Two other potential chelators, known for their biodegradability in comparison to EDTA, were tested in the plant experiment: nitrilo acetic acid (NTA) and citric acid. Uptake of heavy metals was higher in EDDS-treated pots than in EDTA-treated pots. The effects were still considered insufficiently high to consider efficient remediation. This may be partly due to the choice of timing for application of the soil amendment. Fixing the time of application at an earlier point before harvest may yield better results. NTA and citric acid induced no significant effects on heavy metal uptake.

Enhanced brightness of organic light-emitting diodes based on Mg:Ag cathode using alkali metal chlorides as an electron injection layer

International Nuclear Information System (INIS)

Zou Ye; Deng Zhenbo; Xu Denghui; Lü Zhaoyue; Yin Yuehong; Du Hailiang; Chen Zheng; Wang Yongsheng

2012-01-01

Different thicknesses of cesium chloride (CsCl) and various alkali metal chlorides were inserted into organic light-emitting diodes (OLEDs) as electron injection layers (EILs). The basic structure of OLED is indium tin oxide (ITO)/N,N′-diphenyl-N,N′-bis(1-napthyl-phenyl)-1.1′-biphenyl-4.4′-diamine (NPB)/tris-(8-hydroxyquinoline) aluminum (Alq 3 )/Mg:Ag/Ag. The electroluminescent (EL) performance curves show that both the brightness and efficiency of the OLEDs can be obviously enhanced by using a thin alkali metal chloride layer as an EIL. The electron injection barrier height between the Alq 3 layer and Mg:Ag cathode is reduced by inserting a thin alkali metal chloride as an EIL, which results in enhanced electron injection and electron current. Therefore, a better balance of hole and electron currents at the emissive interface is achieved and consequently the brightness and efficiency of OLEDs are improved. - Highlights: ► Alkaline metal chlorides were used as electron injection layers in organic light-emitting diodes based on Mg:Ag cathode. ► Brightness and efficiency of OLEDs with alkaline metal chlorides as electron injection layers were all greatly enhanced. ► The Improved OLED performance was attributed to the possible interfacial chemical reaction. ► Electron-only devices are fabricated to demonstrate the electron injection enhancement.

Sustainable preparation of supported metal nanoparticles and their applications in catalysis.

Science.gov (United States)

Campelo, Juan M; Luna, Diego; Luque, Rafael; Marinas, José M; Romero, Antonio A

2009-01-01

Metal nanoparticles have attracted much attention over the last decade owing to their unique properties as compared to their bulk metal equivalents, including a large surface-to-volume ratio and tunable shapes. To control the properties of nanoparticles with particular respect to shape, size and dispersity is imperative, as these will determine the activity in the desired application. Supported metal nanoparticles are widely employed in catalysis. Recent advances in controlling the shape and size of nanoparticles have opened the possibility to optimise the particle geometry for enhanced catalytic activity, providing the optimum size and surface properties for specific applications. This Review describes the state of the art with respect to the preparation and use of supported metal nanoparticles in catalysis. The main groups of such nanoparticles (noble and transition metal nanoparticles) are highlighted and future prospects are discussed.

Mechanisms of metal sorption by biochars: Biochar characteristics and modifications.

Science.gov (United States)

Li, Hongbo; Dong, Xiaoling; da Silva, Evandro B; de Oliveira, Letuzia M; Chen, Yanshan; Ma, Lena Q

2017-07-01

Biochar produced by thermal decomposition of biomass under oxygen-limited conditions has received increasing attention as a cost-effective sorbent to treat metal-contaminated waters. However, there is a lack of information on the roles of different sorption mechanisms for different metals and recent development of biochar modification to enhance metal sorption capacity, which is critical for biochar field application. This review summarizes the characteristics of biochar (e.g., surface area, porosity, pH, surface charge, functional groups, and mineral components) and main mechanisms governing sorption of As, Cr, Cd, Pb, and Hg by biochar. Biochar properties vary considerably with feedstock material and pyrolysis temperature, with high temperature producing biochars with higher surface area, porosity, pH, and mineral contents, but less functional groups. Different mechanisms dominate sorption of As (complexation and electrostatic interactions), Cr (electrostatic interactions, reduction, and complexation), Cd and Pb (complexation, cation exchange, and precipitation), and Hg (complexation and reduction). Besides sorption mechanisms, recent advance in modifying biochar by loading with minerals, reductants, organic functional groups, and nanoparticles, and activation with alkali solution to enhance metal sorption capacity is discussed. Future research needs for field application of biochar include competitive sorption mechanisms of co-existing metals, biochar reuse, and cost reduction of biochar production. Published by Elsevier Ltd.

Cascading metallic gratings for broadband absorption enhancement in ultrathin plasmonic solar cells

International Nuclear Information System (INIS)

Wen, Long; Sun, Fuhe; Chen, Qin

2014-01-01

The incorporation of plasmonic nanostructures in the thin-film solar cells (TFSCs) is a promising route to harvest light into the nanoscale active layer. However, the light trapping scheme based on the plasmonic effects intrinsically presents narrow-band resonant enhancement of light absorption. Here we demonstrate that by cascading metal nanogratings with different sizes atop the TFSCs, broadband absorption enhancement can be realized by simultaneously exciting multiple localized surface plasmon resonances and inducing strong coupling between the plasmonic modes and photonic modes. As a proof of concept, we demonstrate of 66.5% in the photocurrent in an ultrathin amorphous silicon TFSC with two-dimensional cascaded gratings over the reference cell without gratings

Chemistry and Properties of Complex Intermetallics from Metallic Fluxes

Energy Technology Data Exchange (ETDEWEB)

Kanatzidis, Mercouri G. [Northwestern Univ., Evanston, IL (United States)

2015-03-28

This project investigated the reaction chemistry and synthesis of new intermetallic materials with complex compositions and structures using metallic fluxes as solvents. It was found that the metallic fluxes offer several key advantages in facilitating the formation and crystal growth of new materials. The fluxes mostly explored were liquid aluminum, gallium and indium. The main purpose of this project was to exploit the potential of metallic fluxes as high temperature solvent for materials discovery in the broad class of intermetallics. This work opened new paths to compound formation. We discovered many new Si (or Ge)-based compounds with novel structures, bonding and physicochemical properties. We created new insights about the reaction chemistry that is responsible for stabilizing the new materials. We also studied the structural and compositional relationships to understand their properties. We investigated the use of Group-13 metals Al, Ga and In as solvents and have generated a wide variety of new results including several new ternary and quaternary materials with fascinating structures and properties as well as new insights as to how these systems are stabilized in the fluxes. The project focused on reactions of metals from the rare earth element family in combination with transition metals with Si and Ge. For example molten gallium has serves both as a reactive and non-reactive solvent in the preparation and crystallization of intermetallics in the system RE/M/Ga/Ge(Si). Molten indium behaves similarly in that it too is an excellent reaction medium, but it gives compounds that are different from those obtained from gallium. Some of the new phase identified in the aluminide class are complex phases and may be present in many advanced Al-matrix alloys. Such phases play a key role in determining (either beneficially or detrimentally) the mechanical properties of advanced Al-matrix alloys. This project enhanced our basic knowledge of the solid state chemistry

Development of a metal-clad advanced composite shear web design concept

Science.gov (United States)

Laakso, J. H.

1974-01-01

An advanced composite web concept was developed for potential application to the Space Shuttle Orbiter main engine thrust structure. The program consisted of design synthesis, analysis, detail design, element testing, and large scale component testing. A concept was sought that offered significant weight saving by the use of Boron/Epoxy (B/E) reinforced titanium plate structure. The desired concept was one that was practical and that utilized metal to efficiently improve structural reliability. The resulting development of a unique titanium-clad B/E shear web design concept is described. Three large scale components were fabricated and tested to demonstrate the performance of the concept: a titanium-clad plus or minus 45 deg B/E web laminate stiffened with vertical B/E reinforced aluminum stiffeners.

Determination of hydrogen peroxide in water by chemiluminescence detection, (1). Flow injection type hydrogen peroxide detection system

International Nuclear Information System (INIS)

Yamashiro, Naoya; Uchida, Shunsuke; Satoh, Yoshiyuki; Morishima, Yusuke; Yokoyama, Hiroaki; Satoh, Tomonori; Sugama, Junichi; Yamada, Rie

2004-01-01

A flow injection type hydrogen peroxide detection system with a sub-ppb detection limit has been developed to determine hydrogen peroxide concentration in water sampled from a high temperature, high pressure hydrogen peroxide water loop. The hydrogen peroxide detector is based on luminol chemiluminescence spectroscopy. A small amount of sample water (20 μl) is mixed with a reagent mixture, an aqueous solution of luminol and Co 2+ catalyst, in a mixing cell which is installed just upstream from the detection cell. The optimum values for pH and the concentrations of luminol and Co 2+ ion have been determined to ensure a lower detectable limit and a higher reproducibility. The photocurrent detected by the detection system is expressed by a linear function of the hydrogen peroxide concentration in the region of lower concentration ([H 2 O 2 ] 2 O 2 ] in the region of higher concentration ([H 2 O 2 ] > 10 ppb). The luminous intensity of luminol chemiluminescence is the highest when pH of the reagent mixture is 11.0. Optimization of the major parameters gives the lowest detectable limit of 0.3 ppb. (author)

Value added phytoremediation of metal stressed soils using phosphate solubilizing microbial consortium.

Science.gov (United States)

Gupta, Pratishtha; Kumar, Vipin

2017-01-01

The presence of heavy metals in the soil is a matter of growing concern due to their toxic and non-biodegradable nature. Lack of effectiveness of various conventional methods due to economic and technical constraints resulted in the search for an eco-friendly and cost-effective biological techniques for heavy metal removal from the environment. Until now, phytoremediation has emerged as an innovative technique to address the problem. However, the efficiency of phytoremediation process is hindered under the high metal concentration conditions. Hence, phosphate solubilizing microbes (PSM) assisted phytoremediation technique is gaining more insight as it can reduce the contamination load even under elevated metal stressed conditions. These microbes convert heavy metals into soluble and bioavailable forms, which consequently facilitate phytoremediation. Several studies have reported that the use of microbial consortium for remediation is considered more effective as compared to single strain pure culture. Therefore, this review paper focuses on the current trends in research related to PSM mediated uptake of heavy metal by plants. The efficiency of PSM consortia in enhancing the phytoremediation process has also been reviewed. Moreover, the role of phosphatase enzymes in the mineralization of organic forms of phosphate in soil is further discussed. Biosurfactant mediated bioremediation of metal polluted soils is a matter of extensive research nowadays. Hence, the recent advancement of using biosurfactants in enhanced phytoremediation of metal stressed soils is also described.

Proceedings of the 4th seminar of R and D on advanced ORIENT 'strategy and technical requirement for new resource of noble metals in advanced atomic energy science'

International Nuclear Information System (INIS)

Sasaki, Yuji; Koyama, Shinichi; Ozawa, Masaki

2010-12-01

The 4th Seminar of R and D on advanced ORIENT, 'Strategy and technical requirement for new resource of noble metals in advanced atomic energy science' was held in Swany hall, Rokkasho-Mura, on July 30th, 2010 organized by Japan Atomic Energy Agency. The first meeting of this seminar was held at Oarai, Ibaraki on May, 2007, the second seminar was held at Tokai, on November, 2008, and the third seminar was held at Sendai, on October, 2009. Spent nuclear fuel should be recognized as not only mass of radioactive elements but also potentially useful materials including platinum metals and rare earth elements. Taking the cooperation with universities related companies and research institutes, into consideration, we aimed at expanding and progressing the basic researches. In this seminar, there are many poster presentation included, and the useful discussion with many students are performed. This report records abstracts and figures submitted from the oral speakers in this seminar. (author)

Proceedings of the 4th seminar of R and D on advanced ORIENT 'strategy and technical requirement for new resource of noble metals in advanced atomic energy science'

Energy Technology Data Exchange (ETDEWEB)

Sasaki, Yuji; Koyama, Shinichi; Ozawa, Masaki [Japan Atomic Energy Agency, Nuclear Science and Engineering Directorate, Tokai, Ibaraki (Japan)

2010-12-15

The 4th Seminar of R and D on advanced ORIENT, 'Strategy and technical requirement for new resource of noble metals in advanced atomic energy science' was held in Swany hall, Rokkasho-Mura, on July 30th, 2010 organized by Japan Atomic Energy Agency. The first meeting of this seminar was held at Oarai, Ibaraki on May, 2007, the second seminar was held at Tokai, on November, 2008, and the third seminar was held at Sendai, on October, 2009. Spent nuclear fuel should be recognized as not only mass of radioactive elements but also potentially useful materials including platinum metals and rare earth elements. Taking the cooperation with universities related companies and research institutes, into consideration, we aimed at expanding and progressing the basic researches. In this seminar, there are many poster presentation included, and the useful discussion with many students are performed. This report records abstracts and figures submitted from the oral speakers in this seminar. (author)

Approaches for enhanced phytoextraction of heavy metals.

Science.gov (United States)

Bhargava, Atul; Carmona, Francisco F; Bhargava, Meenakshi; Srivastava, Shilpi

2012-08-30

The contamination of the environment with toxic metals has become a worldwide problem. Metal toxicity affects crop yields, soil biomass and fertility. Soils polluted with heavy metals pose a serious health hazard to humans as well as plants and animals, and often requires soil remediation practices. Phytoextraction refers to the uptake of contaminants from soil or water by plant roots and their translocation to any harvestable plant part. Phytoextraction has the potential to remove contaminants and promote long-term cleanup of soil or wastewater. The success of phytoextraction as a potential environmental cleanup technology depends on factors like metal availability for uptake, as well as plants ability to absorb and accumulate metals in aerial parts. Efforts are ongoing to understand the genetics and biochemistry of metal uptake, transport and storage in hyperaccumulator plants so as to be able to develop transgenic plants with improved phytoremediation capability. Many plant species are being investigated to determine their usefulness for phytoextraction, especially high biomass crops. The present review aims to give an updated version of information available with respect to metal tolerance and accumulation mechanisms in plants, as well as on the environmental and genetic factors affecting heavy metal uptake. The genetic tools of classical breeding and genetic engineering have opened the door to creation of 'remediation' cultivars. An overview is presented on the possible strategies for developing novel genotypes with increased metal accumulation and tolerance to toxicity. Copyright © 2012 Elsevier Ltd. All rights reserved.

Detection of pyrrolizidine alkaloids using flow analysis with both acidic potassium permanganate and tris(2,2'-bipyridyl)ruthenium(II) chemiluminescence

International Nuclear Information System (INIS)

Gorman, Bree A.; Barnett, Neil W.; Bos, Richard

2005-01-01

For the first time, analytically useful chemiluminescence was elicited from the reactions of the pyrrolizidine alkaloids. Heliotrine, retronecine, supinine, monocrotaline and echinatine N-oxide yielded chemiluminescence upon reaction with tris(2,2'-bipyridyl)ruthenium(II) whilst lasiocarpine, its N-oxide and supinine elicited light upon reaction with acidic potassium permanganate. Detection limits for heliotrine were 1.25 x 10 -7 M and 9 x 10 -9 M for tris(2,2'-bipyridyl)ruthenium(III) perchlorate with flow injection analysis (FIA) and the silica-immobilised reagent (4-[4-(dichloromethylsilanyl)-butyl]-4'-methyl-2,2'-bipyridine)bis (2,2'-bipyridyl)ruthenium(II) with sequential injection analysis (SIA), respectively. Lasiocarpine was detectable at 1.4 x 10 -7 M using acidic potassium permanganate with FIA. Additionally, the silica-immobilised reagent was optimised with respect to the oxidant (ammonium ceric nitrate) concentration and the aspiration times which afforded a detection limit for codeine of 5 x 10 -10 M using SIA

Analytical and experimental evaluation of joining silicon nitride to metal and silicon carbide to metal for advanced heat engine applications. Final report

Energy Technology Data Exchange (ETDEWEB)

Kang, S.; Selverian, J.H.; O`Neil, D.; Kim, H. [GTE Labs., Inc., Waltham, MA (US); Kim, K. [Brown Univ., Providence, RI (US). Div. of Engineering

1993-05-01

This report summarizes the results of Phase 2 of Analytical and Experimental Evaluation of Joining Silicon Nitride to Metal and Silicon Carbide to Metal for Advanced Heat Engine Applications. A general methodology was developed to optimize the joint geometry and material systems for 650{degrees}C applications. Failure criteria were derived to predict the fracture of the braze and ceramic. Extensive finite element analyses (FEA) were performed to examine various joint geometries and to evaluate the affect of different interlayers on the residual stress state. Also, material systems composed of coating materials, interlayers, and braze alloys were developed for the program based on the chemical stability and strength of the joints during processing, and service. The FEA results were compared with experiments using two methods: (1) an idealized strength relationship of the ceramic, and (2) a probabilistic analysis of the ceramic strength (NASA CARES). The results showed that the measured strength of the joint reached 30--80% of the strength predicted by FEA. Also, potential high-temperature braze alloys were developed and evaluated for the high-temperature application of ceramic-metal joints. 38 tabs, 29 figs, 20 refs.

Advanced breeder cycle uses metallic fuel

International Nuclear Information System (INIS)

Chang, Y.I.

1991-01-01

Scientists from Argonne National Laboratory have been developing a concept called the Integral fast Reactor (IFR). This fast breeder reactor could effectively increase Uranium resources a hundred fold making nuclear power essentially an inexhaustible energy source. The IFR is outlined. In the IFR, the inherent properties of liquid metal cooling are combined with a new metallic fuel which is allowed to swell and gives an improved burnup level and a radically different refining process to allow breakthroughs in passive safety, fuel cycle economics and waste management. (author)

Advanced numerical simulation based on a non-local micromorphic model for metal forming processes

Directory of Open Access Journals (Sweden)

Diamantopoulou Evangelia

2016-01-01

Full Text Available An advanced numerical methodology is developed for metal forming simulation based on thermodynamically-consistent nonlocal constitutive equations accounting for various fully coupled mechanical phenomena under finite strain in the framework of micromorphic continua. The numerical implementation into ABAQUS/Explicit is made for 2D quadrangular elements thanks to the VUEL users’ subroutine. Simple examples with presence of a damaged area are made in order to show the ability of the proposed methodology to describe the independence of the solution from the space discretization.

Effect of Human and Bovine Serum Albumin on kinetic Chemiluminescence of Mn (III-Tetrakis (4-Sulfonatophenyl Porphyrin-Luminol-Hydrogen Peroxide System

Directory of Open Access Journals (Sweden)

Sayed Yahya Kazemi

2012-01-01

Full Text Available The present work deals with an attempt to study the effect of human and bovine serum albumin on kinetic parameters of chemiluminescence of luminol-hydrogen peroxide system catalyzed by manganese tetrasulfonatophenyl porphyrin (MnTSPP. The investigated parameters involved pseudo-first-order rise and fall rate constant for the chemiluminescence burst, maximum level intensity, time to reach maximum intensity, total light yield, and values of the intensity at maximum CL which were evaluated by nonlinear least square program KINFIT. Because of interaction of metalloporphyrin with proteins, the CL parameters are drastically affected. The systems resulted in Stern-Volmer plots with values of 3.17×105 and 3.7×105M−1 in the quencher concentration range of 1.5×10−6 to 1.5×10−5 M for human serum albumin (HSA and bovine serum albumin (BSA, respectively.

Radiation-Induced Graft Polymerization of Vinyl Monomers with Anion Groups onto MWNT Supports and Their Application as Electrogenerated Chemiluminescence (ECL Biosensors

Directory of Open Access Journals (Sweden)

Ji-Hye Park

2014-01-01

Full Text Available Vinyl polymer-grafted multiwalled carbon nanotube (MWNT supports with anion groups were prepared for use as biosensor supports by radiation-induced graft polymerization (RIGP of the vinyl monomers acryloyl diphosphoric acid (ADPA, acrylic acid (AA, sodium styrenesulfonate (NaSS, and methacrylic acid (MA onto the surface of MWNTs. The electrogenerated chemiluminescence sensors based on a glass carbon electrode (ECL-GCE and a screen printed electrode (ECL-SPE were fabricated by immobilization of Ru(bpy3 2+ complex after coating of vinyl polymer-grafted MWNT inks on the surface of the GCE and SPE without any polymer binders in order to obtain high electrogenerated chemiluminescence intensity. For detection of alcohol concentration, alcohol dehydrogenase (ADH was immobilized onto an ECL-GCE sensor prepared by poly(NaSS-g-MWNT supports. The prepared biosensor based on ADH is suitable for the detection of ethanol concentration in commercial drinks.

Development and validation of a direct sandwich chemiluminescence immunoassay for measuring DNA adducts of benzo[a]pyrene and other polycyclic aromatic hydrocarbons

DEFF Research Database (Denmark)

Georgiadis, Panagiotis; Kovács, Katalin; Kaila, Stella

2012-01-01

We have developed and validated a sandwich chemiluminescence immunoassay (SCIA) which measures polycyclic aromatic hydrocarbon (PAH)-DNA adducts combining high throughput and adequate sensitivity, appropriate for evaluation of adduct levels in human population studies. Fragmented DNA is incubated...

The determination of psilocin and psilocybin in hallucinogenic mushrooms by HPLC utilizing a dual reagent acidic potassium permanganate and tris(2,2'-bipyridyl)ruthenium(II) chemiluminescence detection system.

Science.gov (United States)

Anastos, Nicole; Lewis, Simon W; Barnett, Neil W; Sims, D Noel

2006-01-01

This paper describes a procedure for the determination of psilocin and psilocybin in mushroom extracts using high-performance liquid chromatography with postcolumn chemiluminescence detection. A number of extraction methods for psilocin and psilocybin in hallucinogenic mushrooms were investigated, with a simple methanolic extraction being found to be most effective. Psilocin and psilocybin were extracted from a variety of hallucinogenic mushrooms using methanol. The analytes were separated on a C12 column using a (95:5% v/v) methanol:10 mM ammonium formate, pH 3.5 mobile phase with a run time of 5 min. Detection was realized through a dual reagent chemiluminescence detection system of acidic potassium permanganate and tris(2,2'-bipyridyl)ruthenium(II). The chemiluminescence detection system gave improved detectability when compared with UV absorption at 269 nm, with detection limits of 1.2 x 10(-8) and 3.5 x 10(-9) mol/L being obtained for psilocin and psilocybin, respectively. The procedure was applied to the determination of psilocin and psilocybin in three Australian species of hallucinogenic mushroom.

Chemiluminescence behavior of the carbon dots and the reduced state carbon dots

Energy Technology Data Exchange (ETDEWEB)

Teng, Ping [Key Laboratory on Luminescence and Real-Time Analysis, Ministry of Education, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715 (China); Xie, Jianxin [College of Resources and Environment, Yuxi Normal University, Yuxi, Yunnan 653100 (China); Long, Yijuan; Huang, Xiaoxiao; Zhu, Rui; Wang, Xiliang; Liang, Liping [Key Laboratory on Luminescence and Real-Time Analysis, Ministry of Education, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715 (China); Huang, Yuming, E-mail: ymhuang@swu.edu.cn [Key Laboratory on Luminescence and Real-Time Analysis, Ministry of Education, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715 (China); Zheng, Huzhi, E-mail: zhenghz@swu.edu.cn [Key Laboratory on Luminescence and Real-Time Analysis, Ministry of Education, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715 (China)

2014-02-15

Potassium permanganate (KMnO{sub 4}) can react with two different carbon nanoparticles, i.e., carbon dots (CDs) and reduced state carbon dots (r-CDs), in a strong acid medium to generate chemiluminescence (CL). Furthermore, the different CL intensities and CL behaviors due to the different surface groups on these two kinds of carbon nanoparticles were confirmed. CL spectra, fluorescence spectra, UV–vis absorption spectra, and electron paramagnanetic resonance spectra were applied to investigate the CL mechanism. The main reaction pathways were proposed as follows: for the CL reaction between CDs and KMnO{sub 4}, the excited states of CDs (CDs{sup ⁎}) and Mn(II) (Mn(II){sup ⁎}) emerged as KMnO{sub 4} could inject holes into CDs, then, the CDs{sup ⁎} and Mn(II){sup ⁎} acted as luminophors to yield CL; in the r-CDs-KMnO{sub 4} system, r-CDs were oxidized by KMnO{sub 4} directly, and CDs{sup ⁎} and Mn(II){sup ⁎} were produced, at the same time, CL occurred. What is more interesting is that the CL intensity of the r-CD system is stronger than that of the CD system, which confirms that functional groups have strong effect on the CL behavior. It inspired us that new carbon nanoparticles with excellent luminous performance can be designed by tuning their surface groups. -- Highlights: • Carbon dots (CDs) and reduced state carbon dots (r-CDs) can react with potassium permanganate (KMnO{sub 4}) in a strong acid to generate chemiluminescence (CL). • With different surface groups, the CL intensity of r-CDs-KMnO{sub 4} system is different from that of CDs-KMnO{sub 4} system. • The CL mechanisms of the two systems were investigated.

Direct Metal Laser Sintering: A Digitised Metal Casting Technology

OpenAIRE

Venkatesh, K. Vijay; Nandini, V. Vidyashree

2013-01-01

Dental technology is undergoing advancements at a fast pace and technology is being imported from various other fields. One such imported technology is direct metal laser sintering technology for casting metal crowns. This article will discuss the process of laser sintering for making metal crowns and fixed partial dentures with a understanding of their pros and cons.

Direct metal laser sintering: a digitised metal casting technology.

Science.gov (United States)

Venkatesh, K Vijay; Nandini, V Vidyashree

2013-12-01

Dental technology is undergoing advancements at a fast pace and technology is being imported from various other fields. One such imported technology is direct metal laser sintering technology for casting metal crowns. This article will discuss the process of laser sintering for making metal crowns and fixed partial dentures with a understanding of their pros and cons.

Leading research on super metal. 2. Aluminium materials; Super metal no sendo kenkyu. 2. Ogata sozai (aluminium kei)

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-03-01

Aluminum materials were surveyed to improve aluminum materials drastically so as to play an important role as prospective materials in response to the changing social environment. Aluminum materials have become the following metal materials to iron materials due to their light weight, durability, and profitability. Based on their merits and demerits, it was made clear how the aluminum materials contribute to the future resource saving, energy saving, and global environmental protection. Review was made on the two research and development themes which contribute to the creation of super metals. Hence, the themes proposed are focused on the creation of new aluminum mill products with ultra fine grain structure using very low temperature processing and on the creation of super-formability aluminum alloy sheets by advanced texture control using processing which can enhance the shearing stress. Results of the research and development are expected to provide wide applicability for other metals, ceramics, and polymers. 433 refs., 315 figs., 56 tabs.

The US Advanced Liquid Metal Reactor and the Fast Flux Test Facility Phase IIA passive safety tests

International Nuclear Information System (INIS)

Shen, P.K.; Harris, R.A.; Campbell, L.R.; Dautel, W.A.; Dubberley, A.E.; Gluekler, E.L.

1992-07-01

This report discusses the safety approach of the Advanced Liquid Metal reactor program, sponsored by the US Department of Energy, which relies upon passive reactor responses to off-normal condition to limit power and temperature excursions to levels that allow safety margins. Gas expansion modules (GEM) have included in the design to provide negative reactivity to enhance these margins in the extremely unlikely event that pumping power is lost and the highly reliable scram system fails to operate. The feasibility and beneficial features of these devices were first demonstrated in the core of the Fast Flux Test Facility (FFTF) in 1986. Preapplication safety evaluations by the US Nuclear Regulatory Commission have identified areas that must be addressed if these devices are to be relied on. One of these areas is the response of the reactor when it is critical and the pumps are turned on, resulting in positive reactivity being added to the core. Tests to examine such transients have been performed as part of the continuing FFTF program to confirm the passive safety characteristics of liquid metal reactors (LMR). The primary tests consisted of starting the main coolant pumps, which forced sodium coolant into the GEMS, decreasing neutron leakage and adding positive reactivity. The resulting transients were shown to be benign and easily mitigated by the reactivity feedbacks inherent in the FFTF and all LMRs. Steady-state auxiliary tests of the GEM and feedback reactivity worths accurately predicted the transient results. The auxiliary GEM worth tests also demonstrated that the worth can be determined at a subcritical state, which allows for a verification of the GEM's availability prior to ascending to power

Ligand-enhanced electrokinetic remediation of metal-contaminated marine sediments with high acid buffering capacity.

Science.gov (United States)

Masi, Matteo; Iannelli, Renato; Losito, Gabriella

2016-06-01

The suitability of electrokinetic remediation for removing heavy metals from dredged marine sediments with high acid buffering capacity was investigated. Laboratory-scale electrokinetic remediation experiments were carried out by applying two different voltage gradients to the sediment (0.5 and 0.8 V/cm) while circulating water or two different chelating agents at the electrode compartments. Tap water, 0.1 M citric acid and 0.1 M ethylenediaminetetraacetic acid (EDTA) solutions were used respectively. The investigated metals were Zn, Pb, V, Ni and Cu. In the unenhanced experiment, the acid front could not propagate due to the high acid buffering capacity of the sediments; the production of OH(-) ions at the cathode resulted in a high-pH environment causing the precipitation of CaCO3 and metal hydroxides. The use of citric acid prevented the formation of precipitates, but solubilisation and mobilisation of metal species were not sufficiently achieved. Metal removal was relevant when EDTA was used as the conditioning agent, and the electric potential was raised up to 0.8 V/cm. EDTA led to the formation of negatively charged complexes with metals which migrated towards the anode compartment by electromigration. This result shows that metal removal from sediments with high acid buffering capacity may be achieved by enhancing the electrokinetic process by EDTA addition when the acidification of the medium is not economically and/or environmentally sustainable.

Quantum dynamical simulations of local field enhancement in metal nanoparticles.

Science.gov (United States)

Negre, Christian F A; Perassi, Eduardo M; Coronado, Eduardo A; Sánchez, Cristián G

2013-03-27

Field enhancements (Γ) around small Ag nanoparticles (NPs) are calculated using a quantum dynamical simulation formalism and the results are compared with electrodynamic simulations using the discrete dipole approximation (DDA) in order to address the important issue of the intrinsic atomistic structure of NPs. Quite remarkably, in both quantum and classical approaches the highest values of Γ are located in the same regions around single NPs. However, by introducing a complete atomistic description of the metallic NPs in optical simulations, a different pattern of the Γ distribution is obtained. Knowing the correct pattern of the Γ distribution around NPs is crucial for understanding the spectroscopic features of molecules inside hot spots. The enhancement produced by surface plasmon coupling is studied by using both approaches in NP dimers for different inter-particle distances. The results show that the trend of the variation of Γ versus inter-particle distance is different for classical and quantum simulations. This difference is explained in terms of a charge transfer mechanism that cannot be obtained with classical electrodynamics. Finally, time dependent distribution of the enhancement factor is simulated by introducing a time dependent field perturbation into the Hamiltonian, allowing an assessment of the localized surface plasmon resonance quantum dynamics.

Bioaugmentation with endophytic bacterium E6S homologous to Achromobacter piechaudii enhances metal rhizoaccumulation in host Sedum plumbizincicola

Directory of Open Access Journals (Sweden)

Ying eMa

2016-02-01

Full Text Available Application of hyperaccumulator–endophyte symbiotic systems is a potential approach to improve phytoremediation efficiency, since some beneficial endophytic bacteria are able to detoxify heavy metals, alter metal solubility in soil and facilitate plant growth. The objective of this study was to isolate multi-metal resistant and plant beneficial endophytic bacteria and to evaluate their role in enhancing plant growth and metal accumulation/translocation. The metal resistant endophytic bacterial strain E6S was isolated from stems of the Zn/Cd hyperaccumulator plant Sedum plumbizincicola growing in metalliferous mine soils using Dworkin and Foster salts minimal agar medium with 1-aminocyclopropane-1-carboxylate (ACC as the sole nitrogen source, and identified as homologous to Achromobacter piechaudii based on morphological and biochemical characteristics, partial 16S rDNA sequence and phylogenetic analysis. Strain E6S showed high level of resistance to various metals (Cd, Zn and Pb. Besides utilizing ACC, strain E6S exhibited plant beneficial traits, such as solubilization of phosphate and production of indole-3-acetic acid. Inoculation with E6S significantly increased the bioavailability of Cd, Zn and Pb in soil. In addition, bacterial cells bound considerable amounts of metal ions in the following order: Zn ˃ Cd ˃ Pb. Inoculation of E6S significantly stimulated plant biomass, uptake and bioaccumulation of Cd, Zn and Pb. However, E6S greatly reduced the root to shoot translocation of Cd and Zn, indicating that bacterial inoculation assisted the host plant to uptake and store heavy metals in its root system. Inoculation with the endophytic bacterium E6S homologous to A. piechaudii can improve phytostabilization of metalliferous soils due to its effective ability to enhance in situ metal rhizoaccumulation in plants.

Aircrew helmet design and manufacturing enhancements through the use of advanced technologies

Science.gov (United States)

Cadogan, David P.; George, Alan E.; Winkler, Edward R.

1993-12-01

With the development of helmet mounted displays (HMD) and night vision systems (NVS) for use in military and civil aviation roles, new methods of helmet development need to be explored. The helmet must be designed to provide the user with the most lightweight, form fitting system, while meeting other system performance requirements. This can be achieved through a complete analysis of the system requirements. One such technique for systems analysis, a quality function deployment (QFD) matrix, is explored for this purpose. The advanced helmet development process for developing aircrew helmets includes the utilization of several emerging technologies such as laser scanning, computer aided design (CAD), computer generated patterns from 3-D surfaces, laser cutting of patterns and components, and rapid prototyping (stereolithography). Advanced anthropometry methods for helmet development are also available for use. Besides the application of advanced technologies to be used in the development of helmet assemblies, methods of mass reduction are also discussed. The use of these advanced technologies will minimize errors in the development cycle of the helmet and molds, and should enhance system performance while reducing development time and cost.

Increasing the Stability of Metal-Organic Frameworks

Directory of Open Access Journals (Sweden)

Mathieu Bosch

2014-01-01

Full Text Available Metal-organic frameworks (MOFs are a new category of advanced porous materials undergoing study by many researchers for their vast variety of both novel structures and potentially useful properties arising from them. Their high porosities, tunable structures, and convenient process of introducing both customizable functional groups and unsaturated metal centers have afforded excellent gas sorption and separation ability, catalytic activity, luminescent properties, and more. However, the robustness and reactivity of a given framework are largely dependent on its metal-ligand interactions, where the metal-containing clusters are often vulnerable to ligand substitution by water or other nucleophiles, meaning that the frameworks may collapse upon exposure even to moist air. Other frameworks may collapse upon thermal or vacuum treatment or simply over time. This instability limits the practical uses of many MOFs. In order to further enhance the stability of the framework, many different approaches, such as the utilization of high-valence metal ions or nitrogen-donor ligands, were recently investigated. This review details the efforts of both our research group and others to synthesize MOFs possessing drastically increased chemical and thermal stability, in addition to exemplary performance for catalysis, gas sorption, and separation.

Advancements in rationally designed PGM-free fuel cell catalysts derived from metal–organic frameworks

International Nuclear Information System (INIS)

Barkholtz, Heather M.; Liu, Di-Jia

2016-01-01

Over the past several years, metal-organic framework (MOF)-derived platinum group metal free (PGM-free) electrocatalysts have gained considerable attention due to their high efficiency and low cost as potential replacement for platinum in catalyzing oxygen reduction reaction (ORR). In this review, we summarize the recent advancements in design, synthesis and characterization of MOF-derived ORR catalysts and their performances in acidic and alkaline media. As a result, we also discuss the key challenges such as durability and activity enhancement critical in moving forward this emerging electrocatalyst science.

Surface-enhanced vibrational spectroscopy of B vitamins: what is the effect of SERS-active metals used?

Science.gov (United States)

Kokaislová, A; Matějka, P

2012-05-01

Surface-enhanced Raman scattering (SERS) spectroscopy and surface-enhanced infrared absorption (SEIRA) spectroscopy are analytical tools suitable for the detection of small amounts of various analytes adsorbed on metal surfaces. During recent years, these two spectroscopic methods have become increasingly important in the investigation of adsorption of biomolecules and pharmaceuticals on nanostructured metal surfaces. In this work, the adsorption of B-group vitamins pyridoxine, nicotinic acid, folic acid and riboflavin at electrochemically prepared gold and silver substrates was investigated using Fourier transform SERS spectroscopy at an excitation wavelength of 1,064 nm. Gold and silver substrates were prepared by cathodic reduction on massive platinum targets. In the case of gold substrates, oxidation-reduction cycles were applied to increase the enhancement factor of the gold surface. The SERS spectra of riboflavin, nicotinic acid, folic acid and pyridoxine adsorbed on silver substrates differ significantly from SERS spectra of these B-group vitamins adsorbed on gold substrates. The analysis of near-infrared-excited SERS spectra reveals that each of B-group vitamin investigated interacts with the gold surface via a different mechanism of adsorption to that with the silver surface. In the case of riboflavin adsorbed on silver substrate, the interpretation of surface-enhanced infrared absorption (SEIRA) spectra was also helpful in investigation of the adsorption mechanism.

Transient bowing of core assemblies in advanced liquid metal fast reactors

International Nuclear Information System (INIS)

Kamal, S.A.; Orechwa, Y.

1986-01-01

Two alternative core restraint concepts are considered for a conceptual design of a 900 MWth liquid metal fast reactor core with a heterogeneous layout. The two concepts, known as limited free bowing and free flowering, are evaluated based on core bowing criteria that emphasize the enhancement of inherent reactor safety. The core reactivity change during a postulated loss of flow transient is calculated in terms of the lateral displacements and displacement-reactivity-worths of the individual assemblies. The NUBOW-3D computer code is utilized to determine the assembly deformations and interassembly forces that arise when the assemblies are subjected to temperature gradients and irradiation induced creep and swelling during the reactor operation. The assembly ducts are made of the ferritic steel HT-9 and remain in the reactor core for four-years at full power condition. Whereas both restraint systems meet the bowing criteria, a properly designed limited free bowing system appears to be more advantageous than a free flowering system from the point of view of enhancing the reactor inherent safety

Neutrophil Leukocyte: Combustive Microbicidal Action and Chemiluminescence

Directory of Open Access Journals (Sweden)

Robert C. Allen

2015-01-01

Full Text Available Neutrophil leukocytes protect against a varied and complex array of microbes by providing microbicidal action that is simple, potent, and focused. Neutrophils provide such action via redox reactions that change the frontier orbitals of oxygen (O2 facilitating combustion. The spin conservation rules define the symmetry barrier that prevents direct reaction of diradical O2 with nonradical molecules, explaining why combustion is not spontaneous. In burning, the spin barrier is overcome when energy causes homolytic bond cleavage producing radicals capable of reacting with diradical O2 to yield oxygenated radical products that further participate in reactive propagation. Neutrophil mediated combustion is by a different pathway. Changing the spin quantum state of O2 removes the symmetry restriction to reaction. Electronically excited singlet molecular oxygen (O2*1 is a potent electrophilic reactant with a finite lifetime that restricts its radius of reactivity and focuses combustive action on the target microbe. The resulting exergonic dioxygenation reactions produce electronically excited carbonyls that relax by light emission, that is, chemiluminescence. This overview of neutrophil combustive microbicidal action takes the perspectives of spin conservation and bosonic-fermionic frontier orbital considerations. The necessary principles of particle physics and quantum mechanics are developed and integrated into a fundamental explanation of neutrophil microbicidal metabolism.

FAA/NASA International Symposium on Advanced Structural Integrity Methods for Airframe Durability and Damage Tolerance, part 2

Energy Technology Data Exchange (ETDEWEB)

Harris, C.E.

1994-09-01

The international technical experts in the areas of durability and damage tolerance of metallic airframe structures were assembled to present and discuss recent research findings and the development of advanced design and analysis methods, structural concepts, and advanced materials. The principal focus of the symposium was on the dissemination of new knowledge and the peer-review of progress on the development of advanced methodologies. Papers were presented on the following topics: structural concepts for enhanced durability, damage tolerance, and maintainability; new metallic alloys and processing technology; fatigue crack initiation and small crack effects; fatigue crack growth models; fracture mechanics failure criteria for ductile materials; structural mechanics methodology for residual strength and life prediction; development of flight load spectra for design and testing; and corrosion resistance. Separate articles from this report have been indexed into the database.

Enhancing Catalyzed Decomposition of Na2CO3 with Co2MnO x Nanowire-Decorated Carbon Fibers for Advanced Na-CO2 Batteries.

Science.gov (United States)

Fang, Cong; Luo, Jianmin; Jin, Chengbin; Yuan, Huadong; Sheng, Ouwei; Huang, Hui; Gan, Yongping; Xia, Yang; Liang, Chu; Zhang, Jun; Zhang, Wenkui; Tao, Xinyong

2018-05-23

The metal-CO 2 batteries, especially Na-CO 2 , batteries come into sight owing to their high energy density, ability for CO 2 capture, and the abundance of sodium resource. Besides the sluggish electrochemical reactions at the gas cathodes and the instability of the electrolyte at a high voltage, the final discharge product Na 2 CO 3 is a solid and poor conductor of electricity, which may cause the high overpotential and poor cycle performance for the Na-CO 2 batteries. The promotion of decomposition of Na 2 CO 3 should be an efficient strategy to enhance the electrochemical performance. Here, we design a facile Na 2 CO 3 activation experiment to screen the efficient cathode catalyst for the Na-CO 2 batteries. It is found that the Co 2 MnO x nanowire-decorated carbon fibers (CMO@CF) can promote the Na 2 CO 3 decomposition at the lowest voltage among all these metal oxide-decorated carbon fiber structures. After assembling the Na-CO 2 batteries, the electrodes based on CMO@CF show lower overpotential and better cycling performance compared with the electrodes based on pristine carbon fibers and other metal oxide-modified carbon fibers. We believe this catalyst screening method and the freestanding structure of the CMO@CF electrode may provide an important reference for the development of advanced Na-CO 2 batteries.

US/DOE Man-Machine Integration program for liquid metal reactors

International Nuclear Information System (INIS)

D'Zmura, A.P.; Seeman, S.E.

1985-03-01

The United States Department of Energy (DOE) Man-Machine Integration program was started in 1980 as an addition to the existing Liquid Metal Fast Breeder Reactor safety base technology program. The overall goal of the DOE program is to enhance the operational safety of liquid metal reactors by optimum integration of humans and machines in the overall reactor plant system and by application of the principles of human-factors engineering to the design of equipment, subsystems, facilities, operational aids, procedures and environments. In the four years since its inception the program has concentrated on understanding the control process for Liquid Metal Reactors (LMRs) and on applying advanced computer concepts to this process. This paper describes the products that have been developed in this program, present computer-related programs, and plans for the future

Evaluation of silicon-chemiluminescence monitoring as a novel method for atomic fluorine determination and end point detection in plasma etch systems

NARCIS (Netherlands)

Zijlstra, P.A.; Beenakker, C.I.M.

1981-01-01

Optical methods for the detection of atomic fluorine in plasma etch systems are discussed and an experimental comparison is made between detection by optical emission and by a novel method based on the chemiluminescence from solid silicon in the presence of atomic fluorine. Although both methods

Determination of ethanol using permanganate-CdS quantum dot chemiluminescence system.

Science.gov (United States)

Abolhasani, Jafar; Hassanzadeh, Javad

2015-08-01

A novel and highly sensitive chemiluminescence (CL) method for the determination of ethanol was developed based on the CdS quantum dots (QDs)-permanganate system. It was found that KMnO4 could directly oxidize CdS QDs in acidic media resulting in relatively high CL emission. A possible mechanism was proposed for this reaction based on UV/Vis absorption, fluorescence and the generated CL emission spectra. However, it was observed that ethanol had a remarkable inhibition effect on this system. This effect was exploited in the determination of ethanol within the concentration range 12-300 µg/L, with detection at 4.3 µg/L. In order to evaluate the capability of presented method, it was satisfactorily utilized in the determination of alcohol in real samples. Copyright © 2014 John Wiley & Sons, Ltd.

Fiber-Optic Chemiluminescent Biosensors for Monitoring Aqueous Alcohols and Other Water Quality Parameters

Science.gov (United States)

Verostko, Charles E. (Inventor); Atwater, James E. (Inventor); Akse, James R. (Inventor); DeHart, Jeffrey L. (Inventor); Wheeler, Richard R. (Inventor)

1998-01-01

A "reagentless" chemiluminescent biosensor and method for the determination of hydrogen peroxide, ethanol and D-glucose in water is disclosed. An aqueous stream is basified by passing it through a solid phase base bed. Luminol is then dissolved in the basified effluent at a controlled rate. Oxidation of the luminol is catalyzed by the target chemical to produce emitted light. The intensity of the emitted light is detected as a measure of the target chemical concentration in the aqueous stream. The emitted light can be transmitted by a fiber optic bundle to a remote location from the aqueous stream for a remote reading of the target chemical concentration.

Recent Progress in Self-Supported Metal Oxide Nanoarray Electrodes for Advanced Lithium-Ion Batteries.

Science.gov (United States)

Zhang, Feng; Qi, Limin

2016-09-01

The rational design and fabrication of electrode materials with desirable architectures and optimized properties has been demonstrated to be an effective approach towards high-performance lithium-ion batteries (LIBs). Although nanostructured metal oxide electrodes with high specific capacity have been regarded as the most promising alternatives for replacing commercial electrodes in LIBs, their further developments are still faced with several challenges such as poor cycling stability and unsatisfying rate performance. As a new class of binder-free electrodes for LIBs, self-supported metal oxide nanoarray electrodes have many advantageous features in terms of high specific surface area, fast electron transport, improved charge transfer efficiency, and free space for alleviating volume expansion and preventing severe aggregation, holding great potential to solve the mentioned problems. This review highlights the recent progress in the utilization of self-supported metal oxide nanoarrays grown on 2D planar and 3D porous substrates, such as 1D and 2D nanostructure arrays, hierarchical nanostructure arrays, and heterostructured nanoarrays, as anodes and cathodes for advanced LIBs. Furthermore, the potential applications of these binder-free nanoarray electrodes for practical LIBs in full-cell configuration are outlined. Finally, the future prospects of these self-supported nanoarray electrodes are discussed.

Plasmonic Effects of Metallic Nanoparticles on Enhancing Performance of Perovskite Solar Cells.

Science.gov (United States)

Luo, Qi; Zhang, Chenxi; Deng, Xueshuang; Zhu, Hongbing; Li, Zhiqiang; Wang, Zengbo; Chen, Xiaohong; Huang, Sumei

2017-10-11

We report systematic design and formation of plasmonic perovskite solar cells (PSCs) by integrating Au@TiO 2 core-shell nanoparticles (NPs) into porous TiO 2 and/or perovskite semiconductor capping layers. The plasmonic effects in the formed PSCs are examined. The most efficient configuration is obtained by incorporating Au@TiO 2 NPs into both the porous TiO 2 and the perovskite capping layers, which increases the power conversion efficiency (PCE) from 12.59% to 18.24%, demonstrating over 44% enhancement, compared with the reference device without the metal NPs. The PCE enhancement is mainly attributed to short-circuit current improvement. The plasmonic enhancement effects of Au@TiO 2 core-shell nanosphere photovoltaic composites are explored based on the combination of UV-vis absorption spectroscopy, external quantum efficiency (EQE), photocurrent properties, and photoluminescence (PL). The addition of Au@TiO 2 nanospheres increased the rate of exciton generation and the probability of exciton dissociation, enhancing charge separation/transfer, reducing the recombination rate, and facilitating carrier transport in the device. This study contributes to understanding of plasmonic effects in perovskite solar cells and also provides a promising approach for simultaneous photon energy and electron management.

Enhanced Inter-Cell Interference Coordination in Co-Channel Multi-Layer LTE-Advanced Networks

DEFF Research Database (Denmark)

Pedersen, Klaus I.; Wang, Yuanye; Strzyz, Stanislav

2013-01-01

Different technical solutions and innovations are enabling the move from macro-only scenarios towards heterogeneous networks with a mixture of different base station types. In this article we focus on multi-layer LTE-Advanced networks, and especially address aspects related to interference...... management. The network controlled time-domain enhanced inter-cell interference coordination (eICIC) concept is outlined by explaining the benefits and characteristics of this solution. The benefits of using advanced terminal device receiver architectures with interference suppression capabilities...... are motivated. Extensive system level performance results are presented with bursty traffic to demonstrate the eICIC concepts ability to dynamically adapt according to the traffic conditions....

Detection of pyrrolizidine alkaloids using flow analysis with both acidic potassium permanganate and tris(2,2'-bipyridyl)ruthenium(II) chemiluminescence

Energy Technology Data Exchange (ETDEWEB)

Gorman, Bree A. [School of Biological and Chemical Sciences, Deakin University, Geelong, Vic. 3217 (Australia); Barnett, Neil W. [School of Biological and Chemical Sciences, Deakin University, Geelong, Vic. 3217 (Australia)]. E-mail: barnie@deakin.edu.au; Bos, Richard [School of Biological and Chemical Sciences, Deakin University, Geelong, Vic. 3217 (Australia)

2005-06-13

For the first time, analytically useful chemiluminescence was elicited from the reactions of the pyrrolizidine alkaloids. Heliotrine, retronecine, supinine, monocrotaline and echinatine N-oxide yielded chemiluminescence upon reaction with tris(2,2'-bipyridyl)ruthenium(II) whilst lasiocarpine, its N-oxide and supinine elicited light upon reaction with acidic potassium permanganate. Detection limits for heliotrine were 1.25 x 10{sup -7} M and 9 x 10{sup -9} M for tris(2,2'-bipyridyl)ruthenium(III) perchlorate with flow injection analysis (FIA) and the silica-immobilised reagent (4-[4-(dichloromethylsilanyl)-butyl]-4'-methyl-2,2'-bipyridine)bis (2,2'-bipyridyl)ruthenium(II) with sequential injection analysis (SIA), respectively. Lasiocarpine was detectable at 1.4 x 10{sup -7} M using acidic potassium permanganate with FIA. Additionally, the silica-immobilised reagent was optimised with respect to the oxidant (ammonium ceric nitrate) concentration and the aspiration times which afforded a detection limit for codeine of 5 x 10{sup -10} M using SIA.

An advanced constitutive model in the sheet metal forming simulation: the Teodosiu microstructural model and the Cazacu Barlat yield criterion

International Nuclear Information System (INIS)

Alves, J.L.; Oliveira, M.C.; Menezes, L.F.

2004-01-01

Two constitutive models used to describe the plastic behavior of sheet metals in the numerical simulation of sheet metal forming process are studied: a recently proposed advanced constitutive model based on the Teodosiu microstructural model and the Cazacu Barlat yield criterion is compared with a more classical one, based on the Swift law and the Hill 1948 yield criterion. These constitutive models are implemented into DD3IMP, a finite element home code specifically developed to simulate sheet metal forming processes, which generically is a 3-D elastoplastic finite element code with an updated Lagrangian formulation, following a fully implicit time integration scheme, large elastoplastic strains and rotations. Solid finite elements and parametric surfaces are used to model the blank sheet and tool surfaces, respectively. Some details of the numerical implementation of the constitutive models are given. Finally, the theory is illustrated with the numerical simulation of the deep drawing of a cylindrical cup. The results show that the proposed advanced constitutive model predicts with more exactness the final shape (medium height and ears profile) of the formed part, as one can conclude from the comparison with the experimental results

Step tunneling enhanced asymmetry in metal-insulator-insulator-metal (MIIM) diodes for rectenna applications

Science.gov (United States)

Alimardani, N.; Conley, J. F.

2013-09-01

We combine nanolaminate bilayer insulator tunnel barriers (Al2O3/HfO2, HfO2/Al2O3, Al2O3/ZrO2) deposited via atomic layer deposition (ALD) with asymmetric work function metal electrodes to produce MIIM diodes with enhanced I-V asymmetry and non-linearity. We show that the improvements in MIIM devices are due to step tunneling rather than resonant tunneling. We also investigate conduction processes as a function of temperature in MIM devices with Nb2O5 and Ta2O5 high electron affinity insulators. For both Nb2O5 and Ta2O5 insulators, the dominant conduction process is established as Schottky emission at small biases and Frenkel-Poole emission at large biases. The energy depth of the traps that dominate Frenkel-Poole emission in each material are estimated.

Chemiluminescence-based multivariate sensing of local equivalence ratios in premixed atmospheric methane-air flames

Energy Technology Data Exchange (ETDEWEB)

Tripathi, Markandey M.; Krishnan, Sundar R.; Srinivasan, Kalyan K.; Yueh, Fang-Yu; Singh, Jagdish P.

2011-09-07

Chemiluminescence emissions from OH*, CH*, C2, and CO2 formed within the reaction zone of premixed flames depend upon the fuel-air equivalence ratio in the burning mixture. In the present paper, a new partial least square regression (PLS-R) based multivariate sensing methodology is investigated and compared with an OH*/CH* intensity ratio-based calibration model for sensing equivalence ratio in atmospheric methane-air premixed flames. Five replications of spectral data at nine different equivalence ratios ranging from 0.73 to 1.48 were used in the calibration of both models. During model development, the PLS-R model was initially validated with the calibration data set using the leave-one-out cross validation technique. Since the PLS-R model used the entire raw spectral intensities, it did not need the nonlinear background subtraction of CO2 emission that is required for typical OH*/CH* intensity ratio calibrations. An unbiased spectral data set (not used in the PLS-R model development), for 28 different equivalence ratio conditions ranging from 0.71 to 1.67, was used to predict equivalence ratios using the PLS-R and the intensity ratio calibration models. It was found that the equivalence ratios predicted with the PLS-R based multivariate calibration model matched the experimentally measured equivalence ratios within 7%; whereas, the OH*/CH* intensity ratio calibration grossly underpredicted equivalence ratios in comparison to measured equivalence ratios, especially under rich conditions ( > 1.2). The practical implications of the chemiluminescence-based multivariate equivalence ratio sensing methodology are also discussed.

Metal-core@metal oxide-shell nanomaterials for gas-sensing applications: a review

Energy Technology Data Exchange (ETDEWEB)

Mirzaei, A.; Janghorban, K.; Hashemi, B. [Shiraz University, Department of Materials Science and Engineering (Iran, Islamic Republic of); Neri, G., E-mail: gneri@unime.it [University of Messina, Department of Electronic Engineering, Chemistry and Industrial Engineering (Italy)

2015-09-15

With an ever-increasing number of applications in many advanced fields, gas sensors are becoming indispensable devices in our daily life. Among different types of gas sensors, conductometric metal oxide semiconductor (MOS) gas sensors are found to be the most appealing for advanced applications in the automotive, biomedical, environmental, and safety sectors because of the their high sensitivity, reduced size, and low cost. To improve their sensing characteristics, new metal oxide-based nanostructures have thus been proposed in recent years as sensing materials. In this review, we extensively review gas-sensing properties of core@ shell nanocomposites in which metals as the core and metal oxides as the shell structure, both of nanometer sizes, are assembled into a single metal@metal oxide core–shell. These nanostructures not only combine the properties of both noble metals and metal oxides, but also bring unique synergetic functions in comparison with single-component materials. Up-dated achievements in the synthesis and characterization of metal@metal oxide core–shell nanostructures as well as their use in MOS sensors are here reported with the main objective of providing an overview about their gas-sensing properties.

Testing of seismic isolation bearings for advanced liquid metal reactor prism

International Nuclear Information System (INIS)

Tajirian, F.F.; Kelly, J.M.

1988-01-01

Seismic isolation can significantly mitigate earthquake loads on liquid metal reactors (LMR), thus reducing the impact of seismic loads on design. This improves plant safety margins for beyond-design basis seismic events and enhances adaptability of a standardized design to a variety of sites, with potential cost benefits. The PRISM (Power Reactor Inherently Safe Module) LMR incorporates a horizontal isolation system which consists of high damping steel laminated rubber bearings. The results of an experimental program to determine the mechanical properties of the rubber compound and the bearing performance under different loading conditions are presented. The test results demonstrate the excellent performance of the bearings and their suitability for isolating compact LMR plants

Recent Advances of Solution-Processed Metal Oxide Thin-Film Transistors.

Science.gov (United States)

Xu, Wangying; Li, Hao; Xu, Jian-Bin; Wang, Lei

2018-03-06

Solution-processed metal oxide thin-film transistors (TFTs) are considered as one of the most promising transistor technologies for future large-area flexible electronics. This review surveys the recent advances in solution-based oxide TFTs, including n-type oxide semiconductors, oxide dielectrics and p-type oxide semiconductors. Firstly, we provide an introduction on oxide TFTs and the TFT configurations and operating principles. Secondly, we present the recent progress in solution-processed n-type transistors, with a special focus on low-temperature and large-area solution processed approaches as well as novel non-display applications. Thirdly, we give a detailed analysis of the state-of-the-art solution-processed oxide dielectrics for low-voltage electronics. Fourthly, we discuss the recent progress in solution-based p-type oxide semiconductors, which will enable the highly desirable future low-cost large-area complementary circuits. Finally, we draw the conclusions and outline the perspectives over the research field.

Suitability of thermoluminescence, chemiluminescence, ESR and viscosity measurements as detection method for the irradiation of medicinal herbs

International Nuclear Information System (INIS)

Schuettler, C.; Gebhardt, G.; Stock, A.; Helle, N.; Boegl, K.W.

1993-01-01