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Sample records for situ high sensitivity

  1. Highly Sensitive Tunable Diode Laser Spectrometers for In Situ Planetary Exploration

    Science.gov (United States)

    Vasudev, Ram; Mansour, Kamjou; Webster, Christopher R.

    2013-01-01

    This paper describes highly sensitive tunable diode laser spectrometers suitable for in situ planetary exploration. The technology developed at JPL is based on wavelength modulated cavity enhanced absorption spectroscopy. It is capable of sensitively detecting chemical signatures of life through the abundance of biogenic molecules and their isotopic composition, and chemicals such as water necessary for habitats of life. The technology would be suitable for searching for biomarkers, extinct life, potential habitats of extant life, and signatures of ancient climates on Mars; and for detecting biomarkers, prebiotic chemicals and habitats of life in the outer Solar System. It would be useful for prospecting for water on the Moon and asteroids, and characterizing its isotopic composition. Deployment on the Moon could provide ground truth to the recent remote measurements and help to uncover precious records of the early bombardment history of the inner Solar System buried at the shadowed poles, and elucidate the mechanism for the generation of near-surface water in the illuminated regions. The technology would also be useful for detecting other volatile molecules in planetary atmospheres and subsurface reservoirs, isotopic characterization of planetary materials, and searching for signatures of extinct life preserved in solid matrices.

  2. In situ production of silver nanoparticles for high sensitive detection of ascorbic acid via inner filter effect

    Energy Technology Data Exchange (ETDEWEB)

    Rezaei, B., E-mail: rezaeimeister@gmail.com; Shahshahanipour, M.; Ensafi, Ali A.

    2017-02-01

    In the present research, a sensitive biosensing method was proposed for the detection of trace amounts of ascorbic acid (AA). Herein, colloidal silver nanoparticles (SNPs) were successfully in-situ produced by chemical reduction of silver ion in the presence of AA, as a reducing agent. The one-pot in-situ produced silver nanoparticles were characterized by UV–vis, dynamic light scattering (DLS), zeta potential and transmission electron microscopic (TEM). SNPs act as a strong fluorescence quencher for the CdTe quantum dots via an inner filter effect (IFE). Since the absorption band of SNPs entirely covered both emission and excitation bands of QDs. Therefore, the decreasing in the fluorescence signal depends on the AA concentration in the linear range of 0.2–88.0 ng mL{sup −1} and with a detection limit of 0.02 ng mL{sup −1}. Relative standard deviations of 2.3% and 2.8% (n = 5) were achieved for the determination of 1.8 and 8.8 ng mL{sup −1} AA, respectively. This novel QDs nanosensor based on IFE could provide noticeable advantages of simplicity, convenience, cost-effectiveness, and sensitivity. This method was successfully applied for the detection of ascorbic acid in human real samples serums. - Highlights: • A sensitive and simple method has been developed for detection of ascorbic acid. • Silver nanoparticles as a strong quencher were prepared via the one-step reduction. • Its absorption band covered both emission and excitation bands of CdTe QDs. • So, the fluorescence of CdTe QDs quenching due to Inner filter effect.

  3. Development of high sensitivity gamma and beta sensors for in situ diffusion tests in the mudstone in France

    International Nuclear Information System (INIS)

    Lin, Zhenhua

    2017-01-01

    The precise monitoring of radiotracers, for example used for medical imaging, for the storage of ultimate waste, or for certain industrial applications can be a very complex subject. The development of low-noise sensors with long-term stability and high geometric flexibility were engaged by the AXINT company. (Hautefeuille, et al., 2006). My PhD thesis was focused on experiments in the diffusion of radiotracers, typically to monitor the possible leakage of radioactive products from the geological repositories. We focuses on the study of the "2"2Na and "3"6Cl ion diffusion, which is one of the highest cation and anions diffusion rate in geological medium, as well as actinides, which represent the majority of the radioactive elements of Stored nuclear waste. This thesis is in continuity with the research carried out by ANDRA (National Agency for Radioactive Waste), under contract with the laboratory ILM (Institute Light Matter), of which AXINT is the main subcontractor. The present project describes the research work that foreseen the radiation impact on the environment for the coming years during the deep disposal of nuclear waste. Our work focus on the investigation and quantification of the radionuclide diffusion through the geological clay barriers. A new in situ experiment was considered by Andra for the study of the radionuclide migration. Compared to previous experiments, this new in situ diffusion test required longer distance (hundreds of mm), longer time-scale (over 10 years), and real time in situ monitoring of radionuclides migration. To fulfill these conditions, the work was organized as following: 1: Conception and dimensional design of the Diffusion of Radio Nuclide (DRN) experiments in solving emission of beta and gamma radiations 2: Development of corresponding beta and gamma monitoring systems by means of sensors located in peripheral boreholes. (author) [fr

  4. In situ, high sensitivity, measurement of sup 9 sup 0 strontium in ground water using Cherenkov light

    CERN Document Server

    Bowyer, T W; Hossbach, T W; Hansen, R; Wilcox, W A

    2000-01-01

    The measurement of sup 9 sup 0 Sr in soils and ground water is important for characterization and remediation of radioactively contaminated sites. Measuring the sup 9 sup 0 Sr content to a few pCi/g of soil has been accomplished based on a design of scintillating fibers in a multilayered configuration measuring the high-energy beta emitted from sup 9 sup 0 Y decay (when in secular equilibrium with sup 9 sup 0 Sr), but has not been applied to water because the technique is sensitive to only the first few mm of soil. The volume of the source to which the detector is sensitive limits the theoretical sensitivity of such a detector, unless chemical preprocessing to strip the sup 9 sup 0 Sr from the water is performed. sup 9 sup 0 Sr activity in water can be quantified by detecting the high-energy beta particle by the Cherenkov light it produces when the high-energy beta from sup 9 sup 0 Y passes through the medium. We have used this phenomenon to sensitively measure sup 9 sup 0 Sr ( sup 9 sup 0 Y) from a volume of...

  5. In situ synthesis of oriented NiS nanotube arrays on FTO as high-performance counter electrode for dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yan, E-mail: liyan-nwnu@163.com [Key Laboratory of Atomic and Molecular Physics & Functional Materials of Gansu Province, College of Physics and Electronic Engineering, Northwest Normal University, Lanzhou, 730070 (China); Chang, Yin [Key Laboratory of Atomic and Molecular Physics & Functional Materials of Gansu Province, College of Physics and Electronic Engineering, Northwest Normal University, Lanzhou, 730070 (China); Zhao, Yun [Laboratory of Clean Energy Chemistry and Materials, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou, 730000 (China); Wang, Jian; Wang, Cheng-wei [Key Laboratory of Atomic and Molecular Physics & Functional Materials of Gansu Province, College of Physics and Electronic Engineering, Northwest Normal University, Lanzhou, 730070 (China)

    2016-09-15

    Oriented nickel sulfide (NiS) nanotube arrays were successfully in-situ fabricated on conductive glass substrate and used directly as counter electrode for dye-sensitized solar cells without any post-processing. Compared with Pt counter electrode, for the beneficial effect of electronic transport along the axial direction through the arrays to the substrate, oriented NiS nanotube arrays exhibit both higher electrocatalytic activity for I{sub 3}{sup −} reduction and better electrochemical stability, resulting in a significantly improved power conversion efficiency of 9.8%. Such in-situ grown oriented sulfide semiconductor nanotube arrays is expected to lead a new class structure of composites for highly efficient cathode materials. - Highlights: • In-situ synthesis strategy was proposed to construct oriented NiS nanotube arrays. • Such oriented tube nanostructure benefits the electronic transport along the axial direction of the arrays. • As CE of DSSCs, NiS nanotube arrays exhibit both higher efficiency (9.8%) and electrochemical stability than Pt.

  6. A green, reusable SERS film with high sensitivity for in-situ detection of thiram in apple juice

    Science.gov (United States)

    Sun, Hongbao; Liu, Hai; Wu, Yiyong

    2017-09-01

    We report a green and reusable surface-enhanced Raman scattering (SERS) film based on PMMA/Ag NPs/graphene. By using this Raman substrate, the SERS signals of R6G were significantly enhanced reaching a minimum detectable concentration of 5 × 10-8 M, due to having lots of hot spots adhered backside to the exposed graphene. The SERS film can be used for in-situ monitoring of trace thiram in apple juice with a detection limit of 1 × 10-6 M (0.24 ppm), which is below the maximal residue limit (MRL) of 7 ppm in fruit prescribed by the U.S. Environmental Protection Agency (EPA). Furthermore, reusability studies show that the SERS film can be used repeatedly. In addition, the graphene-enhanced SERS technique shows great potential applications for the in-situ detection and identification of pesticide residues in environmental water, fruits and vegetables.

  7. High sensitive diagnostic technique for virus gene using radioisotope. Development of PCR in situ hybridization and its application

    Energy Technology Data Exchange (ETDEWEB)

    Iwasaki, Takuya; Sada, Tetsutaro; Terai, Masanori; Sato, Yuko; Kurata, Takeshi [National Inst. of Infectious Diseases, Tokyo (Japan); Yamaguchi, Kazuyoshi; Yanagisawa, Akio; Sakai, Yuzo

    1998-02-01

    An animal model, experimentally induced squamous cell carcinoma was produced in hamster mucosa to establish a carcinogenic system inducible by interaction of a virus and chemical(s). Human hydatid mole and cholioepithelioma were chosen as the target subjects. Several tumor cells and host cells were isolated under microscopy and DNA was extracted from these cells to indentify the respective origins (maternal, paternal or host origin). The base sequence of HLADRB region was analyzed by PCR using synthetic primer and the tissue localization was examined by PCR in situ hybridization. A PCR product of 82 bp was found in 15 of 17 samples and there were 2 samples in which the product was not detectable with the constructed primer and 6 samples were negative. While significant differences were not observed by in situ hybridization compared with the negative control. (M.N.)

  8. High sensitive diagnostic technique for virus gene using radioisotope. Development of PCR in situ hybridization and its application

    International Nuclear Information System (INIS)

    Iwasaki, Takuya; Sada, Tetsutaro; Terai, Masanori; Sato, Yuko; Kurata, Takeshi; Yamaguchi, Kazuyoshi; Yanagisawa, Akio; Sakai, Yuzo

    1998-01-01

    An animal model, experimentally induced squamous cell carcinoma was produced in hamster mucosa to establish a carcinogenic system inducible by interaction of a virus and chemical(s). Human hydatid mole and cholioepithelioma were chosen as the target subjects. Several tumor cells and host cells were isolated under microscopy and DNA was extracted from these cells to indentify the respective origins (maternal, paternal or host origin). The base sequence of HLADRB region was analyzed by PCR using synthetic primer and the tissue localization was examined by PCR in situ hybridization. A PCR product of 82 bp was found in 15 of 17 samples and there were 2 samples in which the product was not detectable with the constructed primer and 6 samples were negative. While significant differences were not observed by in situ hybridization compared with the negative control. (M.N.)

  9. Electrospinning in Situ Synthesis of Graphene-Doped Porous Copper Indium Disulfide/Carbon Composite Nanofibers for Highly Efficient Counter Electrode in Dye-Sensitized Solar Cells

    International Nuclear Information System (INIS)

    He, Jianxin; Zhou, Mengjuan; Wang, Lidan; Zhao, Shuyuan; Wang, Qian; Ding, Bin; Cui, Shizhong

    2016-01-01

    Highlights: • P-GN@CuInS 2(*) /C nanofibers were fabricated via electrospinning, in situ synthesis. • CuInS 2 nanocrystals were uniformly anchored in wrapped RGO to form nanofiber structure. • P-GN@CuInS 2 /C nanofibers exhibited porous and 3D superfine fiber morphology. • Graphene nanosheets led well-dispersed growth of CuInS 2 nanocrystals in nanofibers. • DSSC assembled using p-GN@CuInS 2 /C CE delivered a conversion efficiency of 7.23%. - Abstract: Porous graphene-doped copper indium disulfide/carbon (p-GN@CuInS 2 /C) composite nanofibers were fabricated via electrospinning, in situ synthesis, and carbonization. A polyacrylonitrile (PAN) solution containing graphene oxide nanosheets, copper dichloride (CuCl 2 ), indium trichloride (InCl 3 ), and thiourea (Tu.) in a mixed solvent of N,N-dimethylformamide/trichloromethane (DMF/CF) was used as the precursor solution for electrospinning. The resulting porous GN@CuInS 2 /C nanofibers were 107 ± 24 nm in diameter, and graphene nanosheets anchored with chalcopyrite CuInS 2 nanocrystals 7–12 nm in diameter were overlapped and embedded in the carbon matrix, aligning along the fiber axial direction. The Brunauer–Emmett–Teller (BET) surface area of the p-GN@CuInS 2 /C composite nanofibers was 795 m 2 /g, with a total pore volume of 0.71 cm 3 /g. These values were significantly larger than those of the sample without graphene and CuInS 2 /C nanofibers. A dye-sensitized solar cell (DSSC) assembled using the p-GN@CuInS 2 /C nanofibers as the counter electrode (CE) delivered a photoelectric conversion efficiency of 7.23%, which was higher than the efficiencies of DSSCs assembled using the samples without graphene (6.48%) and with the CuInS 2 /C nanofibers (5.45%). It was also much higher than that of the DSSC with a Pt CE (6.34%). The excellent photoelectric performance of the p-GN@CuInS 2 /C CE was attributed to its special hierarchical porous structure, which facilitated permeation of the liquid

  10. In situ spectroscopic ellipsometry as a surface sensitive tool to probe thin film growth

    International Nuclear Information System (INIS)

    Liu, C.

    1999-01-01

    Sputtered thin film and multilayer x-ray mirrors are made routinely at the Advanced Photon Source (APS) for the APS users. Precise film growth control and characterization are very critical in fabricating high-quality x-ray mirrors. Film thickness calibrations are carried out using in situ and ex situ spectroscopic ellipsometry, interferometry, and x-ray scattering. To better understand the growth and optical properties of different thin film systems, we have carried out a systematic study of sputtered thin films of Au, Rh, Pg Pd, Cu, and Cr, using in situ ellipsometry. Multiple data sets were obtained in situ for each film material with incremental thicknesses and were analyzed with their correlation in mind. We found that in situ spectroscopic ellipsometry as a surface-sensitive tool can also be used to probe the growth and morphology of the thin film system. This application of in situ spectroscopic ellipsometry for metal thin film systems will be discussed

  11. High-Sensitivity Spectrophotometry.

    Science.gov (United States)

    Harris, T. D.

    1982-01-01

    Selected high-sensitivity spectrophotometric methods are examined, and comparisons are made of their relative strengths and weaknesses and the circumstances for which each can best be applied. Methods include long path cells, noise reduction, laser intracavity absorption, thermocouple calorimetry, photoacoustic methods, and thermo-optical methods.…

  12. Highly Sensitive Optical Receivers

    CERN Document Server

    Schneider, Kerstin

    2006-01-01

    Highly Sensitive Optical Receivers primarily treats the circuit design of optical receivers with external photodiodes. Continuous-mode and burst-mode receivers are compared. The monograph first summarizes the basics of III/V photodetectors, transistor and noise models, bit-error rate, sensitivity and analog circuit design, thus enabling readers to understand the circuits described in the main part of the book. In order to cover the topic comprehensively, detailed descriptions of receivers for optical data communication in general and, in particular, optical burst-mode receivers in deep-sub-µm CMOS are presented. Numerous detailed and elaborate illustrations facilitate better understanding.

  13. Highly Sensitive and Selective In-Situ SERS Detection of Pb(2+), Hg(2+), and Cd(2+) Using Nanoporous Membrane Functionalized with CNTs.

    Science.gov (United States)

    Shaban, Mohamed; Galaly, A R

    2016-05-04

    Porous Anodic Alumina (PAA) membrane was functionalized with CoFe2O4 nanoparticles and used as a substrate for the growing of very long helical-structured Carbon Nanotubes (CNTs) with a diameter less than 20 nm. The structures and morphologies of the fabricated nanostructures were characterized by field emission- scanning electron microscopy (FE-SEM), energy dispersive X-ray (EDX), and Raman spectroscopy. By uploading the CNTs on PAA, the characteristic Raman peaks of CNTs and PAA showed 4 and 3 times enhancement, respectively, which leads to more sensitive Surface-Enhanced Raman Spectroscopy (SERS) substrates. For comparison, PAA and CNTs/PAA arrays were used as SERS substrates for the detection of Hg(2+), Cd(2+), and Pb(2+). The proposed sensor demonstrated high sensitivity and selectivity between these heavy metal ions. CNTs/PAA sensor showed excellent selectivity toward Pb(2+) over other metal ions, where the enhancement factor is decreased from ~17 for Pb(2+) to ~12 for Hg(2+) and to ~4 for Cd(2+). Therefore, the proposed CNTs/PAA sensor can be used as a powerful tool for the determination of heavy metal ions in aqueous solutions.

  14. Highly Sensitive and Selective In-Situ SERS Detection of Pb2+, Hg2+, and Cd2+ Using Nanoporous Membrane Functionalized with CNTs

    Science.gov (United States)

    Shaban, Mohamed; Galaly, A. R.

    2016-01-01

    Porous Anodic Alumina (PAA) membrane was functionalized with CoFe2O4 nanoparticles and used as a substrate for the growing of very long helical-structured Carbon Nanotubes (CNTs) with a diameter less than 20 nm. The structures and morphologies of the fabricated nanostructures were characterized by field emission- scanning electron microscopy (FE-SEM), energy dispersive X-ray (EDX), and Raman spectroscopy. By uploading the CNTs on PAA, the characteristic Raman peaks of CNTs and PAA showed 4 and 3 times enhancement, respectively, which leads to more sensitive Surface-Enhanced Raman Spectroscopy (SERS) substrates. For comparison, PAA and CNTs/PAA arrays were used as SERS substrates for the detection of Hg2+, Cd2+, and Pb2+. The proposed sensor demonstrated high sensitivity and selectivity between these heavy metal ions. CNTs/PAA sensor showed excellent selectivity toward Pb2+ over other metal ions, where the enhancement factor is decreased from ~17 for Pb2+ to ~12 for Hg2+ and to ~4 for Cd2+. Therefore, the proposed CNTs/PAA sensor can be used as a powerful tool for the determination of heavy metal ions in aqueous solutions. PMID:27143512

  15. In situ sulfur isotopes (δ{sup 34}S and δ{sup 33}S) analyses in sulfides and elemental sulfur using high sensitivity cones combined with the addition of nitrogen by laser ablation MC-ICP-MS

    Energy Technology Data Exchange (ETDEWEB)

    Fu, Jiali [State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences, Wuhan 430074 (China); Hu, Zhaochu, E-mail: zchu@vip.sina.com [State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences, Wuhan 430074 (China); The Beijing SHRIMP Center, Institute of Geology, Chinese Academy of Geological Sciences, Beijing 102206 (China); Zhang, Wen [State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences, Wuhan 430074 (China); Yang, Lu [State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences, Wuhan 430074 (China); National Research Council Canada, 1200 Montreal Rd., Ottawa, Ontario K1A 0R6 (Canada); Liu, Yongsheng; Li, Ming; Zong, Keqing; Gao, Shan; Hu, Shenghong [State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences, Wuhan 430074 (China)

    2016-03-10

    and precise S isotope analysis should be less than 10 μm. Under the selected optimized analytical conditions, excellent agreements between the determined values and the reference values were achieved for the IAEA-S series standard reference materials and a set of six well-characterized, isotopic homogeneous sulfide standards (PPP-1, MoS{sub 2}, MASS-1, P-GBW07267, P-GBW07268, P-GBW07270), validating the capability of the developed method for providing high-quality in situ S isotope data in sulfides and elemental sulfur. - Highlights: • A new approach to obtain in situ S isotope data in sulfides and elemental sulfur. • The use of Jet sample cone and X Skimmer cone improves S sensitivity by a factor of 3.6. • Addition of N{sub 2} efficiently reduces polyatomic interferences and stabilizes the mass bias. • Effective reduction of matrix effect by using the line scan ablation under the optimized fluence. • δ{sup 33}S{sub V-CDT} and δ{sup 34}S{sub V-CDT} values in 12 reference materials are reported.

  16. High order depletion sensitivity analysis

    International Nuclear Information System (INIS)

    Naguib, K.; Adib, M.; Morcos, H.N.

    2002-01-01

    A high order depletion sensitivity method was applied to calculate the sensitivities of build-up of actinides in the irradiated fuel due to cross-section uncertainties. An iteration method based on Taylor series expansion was applied to construct stationary principle, from which all orders of perturbations were calculated. The irradiated EK-10 and MTR-20 fuels at their maximum burn-up of 25% and 65% respectively were considered for sensitivity analysis. The results of calculation show that, in case of EK-10 fuel (low burn-up), the first order sensitivity was found to be enough to perform an accuracy of 1%. While in case of MTR-20 (high burn-up) the fifth order was found to provide 3% accuracy. A computer code SENS was developed to provide the required calculations

  17. High Fidelity In Situ Shoulder Dystocia Simulation

    Directory of Open Access Journals (Sweden)

    Andrew Pelikan, MD

    2018-04-01

    Full Text Available Audience: Resident physicians, emergency department (ED staff Introduction: Precipitous deliveries are high acuity, low occurrence in most emergency departments. Shoulder dystocia is a rare but potentially fatal complication of labor that can be relieved by specific maneuvers that must be implemented in a timely manner. This simulation is designed to educate resident learners on the critical management steps in a shoulder dystocia presenting to the emergency department. A special aspect of this simulation is the unique utilization of the “Noelle” model with an instructing physician at bedside maneuvering the fetus through the stations of labor and providing subtle adjustments to fetal positioning not possible though a mechanized model. A literature search of “shoulder dystocia simulation” consists primarily of obstetrics and mid-wife journals, many of which utilize various mannequin models. None of the reviewed articles utilized a bedside provider maneuvering the fetus with the Noelle model, making this method unique. While the Noelle model is equipped with a remote-controlled motor that automatically rotates and delivers the baby either to the head or to the shoulders and can produce a turtle sign and which will prevent delivery of the baby until signaled to do so by the instructor, using the bedside instructor method allows this simulation to be reproduced with less mechanistically advanced and lower cost models.1-5 Objectives: At the end of this simulation, learners will: 1 Recognize impending delivery and mobilize appropriate resources (ie, both obstetrics [OB] and NICU/pediatrics; 2 Identify risk factors for shoulder dystocia based on history and physical; 3 Recognize shoulder dystocia during delivery; 4 Demonstrate maneuvers to relieve shoulder dystocia; 5 Communicate with team members and nursing staff during resuscitation of a critically ill patient. Method: High-fidelity simulation. Topics: High fidelity, in situ, Noelle model

  18. Community-level sensitivity of a calcifying ecosystem to acute in situ CO2 enrichment

    KAUST Repository

    Burdett, HL

    2017-11-23

    The rate of change in ocean carbonate chemistry is a vital determinant in the magnitude of effects observed. Benthic marine ecosystems are facing an increasing risk of acute CO2 exposure that may be natural or anthropogenically derived (e.g. engineering and industrial activities). However, our understanding of how acute CO2 events impact marine life is restricted to individual organisms, with little understanding for how this manifests at the community level. Here, we investigated in situ the effect of acute CO2 enrichment on the coralline algal ecosystem—a globally ubiquitous, ecologically and economically important habitat, but one which is likely to be sensitive to CO2 enrichment due to its highly calcified reef-like structures engineered by coralline algae. Most notably, we observed a rapid community-level shift to favour net dissolution rather than net calcification. Smaller changes from net respiration to net photosynthesis were also observed. There was no effect on the net flux of DMS/DMSP (algal secondary metabolites), nor on the nutrients nitrate and phosphate. Following return to ambient CO2 levels, only a partial recovery was seen within the monitoring timeframe. This study highlights the sensitivity of biogenic carbonate marine communities to acute CO2 enrichment and raises concerns over the capacity for the system to ‘bounce back’ if subjected to repeated acute high-CO2 events.

  19. Preparation of hydrophilic monolithic capillary column by in situ photo-polymerization of N-vinyl-2-pyrrolidinone and acrylamide for highly selective and sensitive enrichment of N-linked glycopeptides.

    Science.gov (United States)

    Jiang, Hao; Yuan, Huiming; Qu, Yanyan; Liang, Yu; Jiang, Bo; Wu, Qi; Deng, Nan; Liang, Zhen; Zhang, Lihua; Zhang, Yukui

    2016-01-01

    In this study, a novel kind of amide functionalized hydrophilic monolith was synthesized by the in situ photo-polymerization of N-vinyl-2-pyrrolidinone (NVP), acrylamide (AM), and N, N'-methylenebisacrylamide (MBA) in a UV transparent capillary, and successfully applied for hydrophilic interaction chromatography (HILIC) based enrichment of N-linked glycopeptides. With 2 μg of the tryptic digests of IgG as the sample, after enrichment, 18 glycopeptides could be identified by MALDI-TOF/TOF MS analysis. Furthermore, with the mixture of BSA and IgG digests (10,000:1, m/m) as the sample, 6 N-linked glycopeptides were unambiguously identified after enrichment, indicating the high selectivity and good specificity of such material. Moreover, such a monolithic capillary column was also applied for the N-glycosylation sites profiling of 6 μg protein digests from HeLa cells and 1 μL human serum. In total, 530 and 262 unique N-glycosylated peptides were identified, respectively, corresponding to 282 and 124N-glycoproteins, demonstrating its great potential for the large scale glycoproteomics analysis. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. In situ bioremediation under high saline conditions

    International Nuclear Information System (INIS)

    Bosshard, B.; Raumin, J.; Saurohan, B.

    1995-01-01

    An in situ bioremediation treatability study is in progress at the Salton Sea Test Base (SSTB) under the NAVY CLEAN 2 contract. The site is located in the vicinity of the Salon Sea with expected groundwater saline levels of up to 50,000 ppm. The site is contaminated with diesel, gasoline and fuel oils. The treatability study is assessing the use of indigenous heterotrophic bacteria to remediate petroleum hydrocarbons. Low levels of significant macro nutrients indicate that nutrient addition of metabolic nitrogen and Orthophosphate are necessary to promote the process, requiring unique nutrient addition schemes. Groundwater major ion chemistry indicates that precipitation of calcium phosphorus compounds may be stimulated by air-sparging operations and nutrient addition, which has mandated the remedial system to include pneumatic fracturing as an option. This presentation is tailored at an introductory level to in situ bioremediation technologies, with some emphasize on innovations in sparge air delivery, dissolved oxygen uptake rates, nutrient delivery, and pneumatic fracturing that should keep the expert's interest

  1. In situ preparation of NiS2/CoS2 composite electrocatalytic materials on conductive glass substrates with electronic modulation for high-performance counter electrodes of dye-sensitized solar cells

    Science.gov (United States)

    Li, Faxin; Wang, Jiali; Zheng, Li; Zhao, Yaqiang; Huang, Niu; Sun, Panpan; Fang, Liang; Wang, Lei; Sun, Xiaohua

    2018-04-01

    The electrocatalytic composite materials of honeycomb structure NiS2 nanosheets loaded with metallic CoS2 nanoparticles are in situ prepared on F doped SnO2 conductive glass (FTO) substrates used as counter electrodes of DSSCs through chemical bath deposition (CBD) and sulfidizing process. Single crystalline NiS2 honeycomb structure array lay a foundation for the large surface area of NiS2/CoS2 composite CEs. The formed NiS2/CoS2 nanointerface modulates electronic structure of composite CEs from the synergetic interactions between CoS2 nanoparticles and NiS2 nanosheets, which dramatically improves the electrocatalytic activity of NiS2/CoS2 composite CEs; Metallic CoS2 nanoparticles covering NiS2 nanosheets electrodes adjusts the electrodes' structure and then reduces the series resistance (Rs) and the Nernst diffusion resistance (Zw) of counter electrodes. The improvement of these areas greatly enhances the electrocatalytic performance of CEs and the short circuit current density (Jsc) and Fill factor (FF) of DSSCs. Impressively, the DSSC based on NiS2/CoS2-0.1 CE shows the best photovoltaic performance with photovoltaic conversion efficiency of 8.22%, which is 24.36% higher than that (6.61%) of the DSSC with Pt CE. And the NiS2/CoS2-0.1 CE also displays a good stability in the iodine based electrolyte. This work indicates that rational construction of composite electrocatalytic materials paves an avenue for high-performance counter electrodes of DSSCs.

  2. Sensitive determination of mercury by a miniaturized spectrophotometer after in situ single-drop microextraction.

    Science.gov (United States)

    Yang, Fangwen; Liu, Rui; Tan, Zhiqiang; Wen, Xiaodong; Zheng, Chengbin; Lv, Yi

    2010-11-15

    An in situ single-drop microextraction (SDME) method was developed for trace mercury determination by a miniaturized spectrophotometer, in which a simple and cheap light-emitting diode (LED) was employed as the light source, and a handheld charge coupled device (CCD) was served as the detector. A droplet of 0.006% dithizone-CCl(4) (m/v) was used as extraction phase and hanged on a rolled PTFE tube. LED light was adjusted carefully to pass through the centre of the droplet and the entrance slit of the CCD detector. The radiation intensities of 475 nm before and after SDME (I(0) and I(i)) were recorded for quantification. Under the optimum conditions, the system provided a linear range of 2-50 μg L(-1), with a correlation coefficient of 0.9983 and a limit of detection (3σ) of 0.2 μg L(-1). The enrichment factor was about 69. The present method showed the merits of high sensitivity, simplicity, rapidity, low reagent consumption and field analysis potential. Finally, this method was successfully applied for the determination of the total mercury in spiked tap water sample, spiked river water sample and certified reference material (GBW (E) 080393, simulated water). Copyright © 2010 Elsevier B.V. All rights reserved.

  3. Sensitive determination of mercury by a miniaturized spectrophotometer after in situ single-drop microextraction

    International Nuclear Information System (INIS)

    Yang Fangwen; Liu Rui; Tan Zhiqiang; Wen Xiaodong; Zheng Chengbin; Lv Yi

    2010-01-01

    An in situ single-drop microextraction (SDME) method was developed for trace mercury determination by a miniaturized spectrophotometer, in which a simple and cheap light-emitting diode (LED) was employed as the light source, and a handheld charge coupled device (CCD) was served as the detector. A droplet of 0.006% dithizone-CCl 4 (m/v) was used as extraction phase and hanged on a rolled PTFE tube. LED light was adjusted carefully to pass through the centre of the droplet and the entrance slit of the CCD detector. The radiation intensities of 475 nm before and after SDME (I 0 and I i ) were recorded for quantification. Under the optimum conditions, the system provided a linear range of 2-50 μg L -1 , with a correlation coefficient of 0.9983 and a limit of detection (3σ) of 0.2 μg L -1 . The enrichment factor was about 69. The present method showed the merits of high sensitivity, simplicity, rapidity, low reagent consumption and field analysis potential. Finally, this method was successfully applied for the determination of the total mercury in spiked tap water sample, spiked river water sample and certified reference material (GBW (E) 080393, simulated water).

  4. Optimizing structure in nanodiamonds using in-situ strain-sensitive Bragg coherent diffraction imaging.

    Science.gov (United States)

    Hruszkewycz, Stephan; Cha, Wonsuk; Ulvestad, Andrew; Fuoss, Paul; Heremans, F. Joseph; Harder, Ross; Andrich, Paolo; Anderson, Christopher; Awschalom, David

    The nitrogen-vacancy center in diamond has attracted considerable attention for nanoscale sensing due to unique optical and spin properties. Many of these applications require diamond nanoparticles which contain large amounts of residual strain due to the detonation or milling process used in their fabrication. Here, we present experimental, in-situ observations of changes in morphology and internal strain state of commercial nanodiamonds during high-temperature annealing using Bragg coherent diffraction imaging to reconstruct a strain-sensitive 3D image of individual sub-micron-sized crystals. We find minimal structural changes to the nanodiamonds at temperatures less than 650 C, and that at higher temperatures up to 750 C, the diamond-structured volume fraction of nanocrystals tend to shrink. The degree of internal lattice distortions within nanodiamond particles also decreases during the anneal. Our findings potentially enable the design of efficient processing of commercial nanodiamonds into viable materials suitable for device design. We acknowledge support from U.S. DOE, Office of Science, BES, MSE.

  5. In-situ nitrite analysis in high level waste tanks

    International Nuclear Information System (INIS)

    O'Rourke, P.E.; Prather, W.S.; Livingston, R.R.

    1992-01-01

    The Savannah River Site produces special nuclear materials used in the defense of the United States. Most of the processes at SRS are primarily chemical separations and purifications. In-situ chemical analyses help improve the safety, efficiency and quality of these operations. One area where in situ fiberoptic spectroscopy can have a great impact is the management of high level radioactive waste. High level radioactive waste at SRS is stored in more than 50 large waste tanks. The waste exists as a slurry of nitrate salts and metal hydroxides at pH's higher than 10. Sodium Nitrite is added to the tanks as a corrosion inhibitor. In-situ fiberoptic probes are being developed to measure the nitrate, nitrite and hydroxide concentrations in both liquid and solid fractions. Nitrite levels can be measured between 0.01M and 1M in a 1mm pathlength optical cell

  6. An Equation-of-State Compositional In-Situ Combustion Model: A Study of Phase Behavior Sensitivity

    DEFF Research Database (Denmark)

    Kristensen, Morten Rode; Gerritsen, M. G.; Thomsen, Per Grove

    2009-01-01

    phase behavior sensitivity for in situ combustion, a thermal oil recovery process. For the one-dimensional model we first study the sensitivity to numerical discretization errors and provide grid density guidelines for proper resolution of in situ combustion behavior. A critical condition for success...... to ignition. For a particular oil we show that the simplified approach overestimates the required air injection rate for sustained front propagation by 17% compared to the equation of state-based approach....

  7. Value of sensitive in-situ environmental assets in energy resource extraction

    International Nuclear Information System (INIS)

    Thampapillai, Dodo J.

    2011-01-01

    The extraction of energy resources and the preservation of sensitive in-situ environmental assets are invariably mutually exclusive alternatives. The opportunity cost value of preserving the environmental assets can be assessed by recourse to resource rent taxes, and threshold values. The case study analysis carried out in this paper suggests that the preservation of these assets could be justifiable on the grounds of “acceptable sacrifice”. - Highlights: ► Resource rents owed to the state from energy resource extraction can be significant. ► Benefits if mining energy resources are over-stated when the role of sensitive environmental assets is ignored. ► Threshold values could help to resolve conflicts between environmental preservation and resource extraction.

  8. Phase sensitive diffraction sensor for high sensitivity refractive index measurement

    Science.gov (United States)

    Kumawat, Nityanand; Varma, Manoj; Kumar, Sunil

    2018-02-01

    In this study a diffraction based sensor has been developed for bio molecular sensing applications and performing assays in real time. A diffraction grating fabricated on a glass substrate produced diffraction patterns both in transmission and reflection when illuminated by a laser diode. We used zeroth order I(0,0) as reference and first order I(0,1) as signal channel and conducted ratiometric measurements that reduced noise by more than 50 times. The ratiometric approach resulted in a very simple instrumentation with very high sensitivity. In the past, we have shown refractive index measurements both for bulk and surface adsorption using the diffractive self-referencing approach. In the current work we extend the same concept to higher diffraction orders. We have considered order I(0,1) and I(1,1) and performed ratiometric measurements I(0,1)/I(1,1) to eliminate the common mode fluctuations. Since orders I(0,1) and I(1,1) behaved opposite to each other, the resulting ratio signal amplitude increased more than twice compared to our previous results. As a proof of concept we used different salt concentrations in DI water. Increased signal amplitude and improved fluid injection system resulted in more than 4 times improvement in detection limit, giving limit of detection 1.3×10-7 refractive index unit (RIU) compared to our previous results. The improved refractive index sensitivity will help significantly for high sensitivity label free bio sensing application in a very cost-effective and simple experimental set-up.

  9. Nasal delivery of analgesic ketorolac tromethamine thermo- and ion-sensitive in situ hydrogels.

    Science.gov (United States)

    Li, Xin; Du, Lina; Chen, Xu; Ge, Pingju; Wang, Yu; Fu, Yangmu; Sun, Haiyan; Jiang, Qingwei; Jin, Yiguang

    2015-07-15

    Ketorolac tromethamine (KT) was potent to treat moderate to moderately severe pains. However, KT solutions for nasal delivery lost quickly from the nasal route. Thermo- and ion-sensitive in-situ hydrogels (ISGs) are appropriate for nasal drug delivery because the intranasal temperature maintains ∼37 °C and nasal fluids consist of plentiful cations. In this study, a novel nasal thermo- and ion-sensitive ISG of KT was prepared with thermo-sensitive poloxamer 407 (P407) and ion-sensitive deacetylated gellan gum (DGG). The optimal formulation of the KT ISG consisted of 3% (w/v) DGG and 18% (w/v) P407 and its viscosity was up to 7.63 Pas at 37 °C. Furthermore, penetration enhancers and bacterial inhibitors were added and their fractions in the ISG were optimized based on transmucosal efficiencies and toxicity on toad pili. Sulfobutyl ether-β-cyclodextrin of 2.5% (w/v) and chlorobutanol of 0.5% (w/v) were chosen as the penetration enhancer and the bacterial inhibitor, respectively. The Fick's diffusion and dissolution of KT could drive it continuous release from the dually sensitive ISG according to the in vitro investigation. Two methods, writhing frequencies induced by acetic acid and latency time of tails retracting from hot water, were used to evaluate the pharmacodynamics of the KT ISG on the mouse models. The writhing frequencies significantly decreased and the latency time of tail retracting was obviously prolonged (pthermo- and ion-sensitive KT ISG had appropriate gelation temperature, sustained drug release, improved intranasal absorption, obvious pharmacodynamic effect, and negligible nasal ciliotoxicity. It is a promising intranasal analgesic formulation. Copyright © 2015. Published by Elsevier B.V.

  10. High Throughput In Situ XAFS Screening of Catalysts

    International Nuclear Information System (INIS)

    Tsapatsaris, Nikolaos; Beesley, Angela M.; Weiher, Norbert; Tatton, Helen; Schroeder, Sven L. M.; Dent, Andy J.; Mosselmans, Frederick J. W.; Tromp, Moniek; Russu, Sergio; Evans, John; Harvey, Ian; Hayama, Shu

    2007-01-01

    We outline and demonstrate the feasibility of high-throughput (HT) in situ XAFS for synchrotron radiation studies. An XAS data acquisition and control system for the analysis of dynamic materials libraries under control of temperature and gaseous environments has been developed. The system is compatible with the 96-well industry standard and coupled to multi-stream quadrupole mass spectrometry (QMS) analysis of reactor effluents. An automated analytical workflow generates data quickly compared to traditional individual spectrum acquisition and analyses them in quasi-real time using an HT data analysis tool based on IFFEFIT. The system was used for the automated characterization of a library of 91 catalyst precursors containing ternary combinations of Cu, Pt, and Au on γ-Al2O3, and for the in situ characterization of Au catalysts supported on Al2O3 and TiO2

  11. High sensitivity optical molecular imaging system

    Science.gov (United States)

    An, Yu; Yuan, Gao; Huang, Chao; Jiang, Shixin; Zhang, Peng; Wang, Kun; Tian, Jie

    2018-02-01

    Optical Molecular Imaging (OMI) has the advantages of high sensitivity, low cost and ease of use. By labeling the regions of interest with fluorescent or bioluminescence probes, OMI can noninvasively obtain the distribution of the probes in vivo, which play the key role in cancer research, pharmacokinetics and other biological studies. In preclinical and clinical application, the image depth, resolution and sensitivity are the key factors for researchers to use OMI. In this paper, we report a high sensitivity optical molecular imaging system developed by our group, which can improve the imaging depth in phantom to nearly 5cm, high resolution at 2cm depth, and high image sensitivity. To validate the performance of the system, special designed phantom experiments and weak light detection experiment were implemented. The results shows that cooperated with high performance electron-multiplying charge coupled device (EMCCD) camera, precision design of light path system and high efficient image techniques, our OMI system can simultaneously collect the light-emitted signals generated by fluorescence molecular imaging, bioluminescence imaging, Cherenkov luminance and other optical imaging modality, and observe the internal distribution of light-emitting agents fast and accurately.

  12. High quality protein microarray using in situ protein purification

    Directory of Open Access Journals (Sweden)

    Fleischmann Robert D

    2009-08-01

    Full Text Available Abstract Background In the postgenomic era, high throughput protein expression and protein microarray technologies have progressed markedly permitting screening of therapeutic reagents and discovery of novel protein functions. Hexa-histidine is one of the most commonly used fusion tags for protein expression due to its small size and convenient purification via immobilized metal ion affinity chromatography (IMAC. This purification process has been adapted to the protein microarray format, but the quality of in situ His-tagged protein purification on slides has not been systematically evaluated. We established methods to determine the level of purification of such proteins on metal chelate-modified slide surfaces. Optimized in situ purification of His-tagged recombinant proteins has the potential to become the new gold standard for cost-effective generation of high-quality and high-density protein microarrays. Results Two slide surfaces were examined, chelated Cu2+ slides suspended on a polyethylene glycol (PEG coating and chelated Ni2+ slides immobilized on a support without PEG coating. Using PEG-coated chelated Cu2+ slides, consistently higher purities of recombinant proteins were measured. An optimized wash buffer (PBST composed of 10 mM phosphate buffer, 2.7 mM KCl, 140 mM NaCl and 0.05% Tween 20, pH 7.4, further improved protein purity levels. Using Escherichia coli cell lysates expressing 90 recombinant Streptococcus pneumoniae proteins, 73 proteins were successfully immobilized, and 66 proteins were in situ purified with greater than 90% purity. We identified several antigens among the in situ-purified proteins via assays with anti-S. pneumoniae rabbit antibodies and a human patient antiserum, as a demonstration project of large scale microarray-based immunoproteomics profiling. The methodology is compatible with higher throughput formats of in vivo protein expression, eliminates the need for resin-based purification and circumvents

  13. Factors influencing the drug sensitization of human tumor cells for in situ lipofection.

    Science.gov (United States)

    Son, K; Huang, L

    1996-07-01

    The cisplatin induced enhancement of in situ lipofection was optimized by considering the factors that can increase the degree of sensitization. Two other anticancer drugs, mechlorethamine (nitrogen mustard) and taxol, enhanced CAT gene expression but the degree of sensitization was not as great as cisplatin. Besides human 2008 ovarian cancer cells we also found that human lung (A549) and head and neck cancer cells (SCC 25) were transiently sensitized by cisplatin. The transfectability of the two commercially available cationic liposomes, Lipofectin and LipofectAmine, was either weak or not consistent among tumors tested. In vivo transfection efficiency of 2008 cells was the highest at 1 microgram DNA per nmol or microgram liposome with all three cationic liposomes. In vitro transfection efficiency of 2008 cells at 1:1 (microgram of DNA:nmole of DC-chol/DOPE liposome) increased in a dose-dependent manner while at 1:10, an optimal ratio for in vitro lipofection, rapidly decreased with an increase in dose. This result indicated that there was a correlation between in vivo and in vitro lipofection at 1:1 ratio for delivering liposomal DNA. Most of the DNA injected into the tumor was concentrated in the tumor and in the skin above the tumor whether cisplatin was preinjected or liposomes were used as carriers.

  14. Analysis of leachability for a sandstone uranium deposite with high acid consumption and sensitivities in Inner Mongolia

    International Nuclear Information System (INIS)

    Cheng Wei; Miao Aisheng; Li Jianhua; Zhou Lei; Chang Jingtao

    2014-01-01

    In-situ Leaching adaptability of a ground water oxidation zone type sandstone uranium deposit from Inner Mongolia is studied. The ore of the uranium deposit has high acid consumption and sensitivities in in-situ leaching. The leaching process with agent of CO_2 + O_2 and adjusting concentration of HCO_3"- can be suitable for the deposit. (authors)

  15. Heterogeneous catalysis in highly sensitive microreactors

    DEFF Research Database (Denmark)

    Olsen, Jakob Lind

    This thesis present a highly sensitive silicon microreactor and examples of its use in studying catalysis. The experimental setup built for gas handling and temperature control for the microreactor is described. The implementation of LabVIEW interfacing for all the experimental parts makes...

  16. Aluminum nanocantilevers for high sensitivity mass sensors

    DEFF Research Database (Denmark)

    Davis, Zachary James; Boisen, Anja

    2005-01-01

    We have fabricated Al nanocantilevers using a simple, one mask contact UV lithography technique with lateral and vertical dimensions under 500 and 100 nm, respectively. These devices are demonstrated as highly sensitive mass sensors by measuring their dynamic properties. Furthermore, it is shown ...

  17. Variation of contrast sensitivity after femtosecond laser in situ keratomileusis in changes environments

    Directory of Open Access Journals (Sweden)

    Jing Zhou

    2015-01-01

    Full Text Available AIM: To evaluate the difference of contrast sensitivity(CSin photopic and scotopic environments in eyes with myopia and myopic astigmatism operated with femtosecond laser in situ keratomileusis(femto-LASIKand laser in situ keratomileusis(LASIK.METHODS: In a prospective study 160 myopia and myopic astigmatism patients' eyes were involved, which accepted femto-LASIK or LASIK in our hospital from January 2010 to February 2012. The myopia degree was -1.50~-10.00D, the astigmatism degree ≤-6.0D. Eighty eyes were treated with femto-LASIK in group A, and 80 eyes were treated with LASIK in group B, All patients in the treatment group completed the final 6mo of follow-up. The uncorrected visual acuity(UCVAand the best spectacle-corrected visual acuity(BSCVA, objective and manifest refractions, results of slit-lamp examination, the side effects, intraocular pressure, corneal topography, CS in photopic and scotopic environments were noted.RESULTS: All of operations on 160 cases were successful without severe complication after 6 mo follow-up. CS of femto-LASIK group(group Aat each spatial frequency environment were higher than that of LASIK group(group B. In group A, after 1mo the photopic CS, after 3mo of scotopic CS recovered to the preoperative level, 6mo after surgery improved than before the operation. In group B, after 3mo photopic CS to the preoperative level, scotopic CS at 6mo after operation was still not recovered to the preoperative level.CONCLUSION:Femto-LASIK for correction of myopia and myopic astigmatism, in improving the postoperative contrast sensitivity under shade environment has more advantages than LASIK.

  18. Single photon detector with high polarization sensitivity.

    Science.gov (United States)

    Guo, Qi; Li, Hao; You, LiXing; Zhang, WeiJun; Zhang, Lu; Wang, Zhen; Xie, XiaoMing; Qi, Ming

    2015-04-15

    Polarization is one of the key parameters of light. Most optical detectors are intensity detectors that are insensitive to the polarization of light. A superconducting nanowire single photon detector (SNSPD) is naturally sensitive to polarization due to its nanowire structure. Previous studies focused on producing a polarization-insensitive SNSPD. In this study, by adjusting the width and pitch of the nanowire, we systematically investigate the preparation of an SNSPD with high polarization sensitivity. Subsequently, an SNSPD with a system detection efficiency of 12% and a polarization extinction ratio of 22 was successfully prepared.

  19. Highly sensitive microcalorimeters for radiation research

    International Nuclear Information System (INIS)

    Avaev, V.N.; Demchuk, B.N.; Ioffe, L.A.; Efimov, E.P.

    1984-01-01

    Calorimetry is used in research at various types of nuclear-physics installations to obtain information on the quantitative and qualitative composition of ionizing radiation in a reactor core and in the surrounding layers of the biological shield. In this paper, the authors examine the characteristics of highly sensitive microcalorimeters with modular semiconductor heat pickups designed for operation in reactor channels. The microcalorimeters have a thin-walled aluminum housing on whose inner surface modular heat pickups are placed radially as shown here. The results of measurements of the temperature dependence of the sensitivity of the microcalorimeters are shown. The results of measuring the sensitivity of a PMK-2 microcalorimeter assembly as a function of integrated neutron flux for three energy intervals and the adsorbed gamma energy are shown. In order to study specimens with different shapes and sizes, microcalorimeters with chambers in the form of cylinders and a parallelepiped were built and tested

  20. High blood pressure and visual sensitivity

    Science.gov (United States)

    Eisner, Alvin; Samples, John R.

    2003-09-01

    The study had two main purposes: (1) to determine whether the foveal visual sensitivities of people treated for high blood pressure (vascular hypertension) differ from the sensitivities of people who have not been diagnosed with high blood pressure and (2) to understand how visual adaptation is related to standard measures of systemic cardiovascular function. Two groups of middle-aged subjects-hypertensive and normotensive-were examined with a series of test/background stimulus combinations. All subjects met rigorous inclusion criteria for excellent ocular health. Although the visual sensitivities of the two subject groups overlapped extensively, the age-related rate of sensitivity loss was, for some measures, greater for the hypertensive subjects, possibly because of adaptation differences between the two groups. Overall, the degree of steady-state sensitivity loss resulting from an increase of background illuminance (for 580-nm backgrounds) was slightly less for the hypertensive subjects. Among normotensive subjects, the ability of a bright (3.8-log-td), long-wavelength (640-nm) adapting background to selectively suppress the flicker response of long-wavelength-sensitive (LWS) cones was related inversely to the ratio of mean arterial blood pressure to heart rate. The degree of selective suppression was also related to heart rate alone, and there was evidence that short-term changes of cardiovascular response were important. The results suggest that (1) vascular hypertension, or possibly its treatment, subtly affects visual function even in the absence of eye disease and (2) changes in blood flow affect retinal light-adaptation processes involved in the selective suppression of the flicker response from LWS cones caused by bright, long-wavelength backgrounds.

  1. Reducing Water Sensitivity of Chitosan Biocomposite Films Using Gliadin Particles Made by In Situ Method

    Directory of Open Access Journals (Sweden)

    Dajian Huang

    2017-11-01

    Full Text Available In order to sustain rapid expansion in the field of biocomposites, it is necessary to develop novel fillers that are biodegradable, and easy to disperse and obtain. In this work, gliadin particles (GPs fabricated through an in situ method have been reported as fillers for creating chitosan (CS-based biocomposite films. In general, the particles tend to agglomerate in the polymer matrix at high loading (approximately >10% in the biopolymer/particles composites prepared by the traditional solution-blending method. However, the micrographs of biocomposites confirmed that the GPs are well dispersed in the CS matrix in all CS/GPs composites even at a high loading of 30% in this study. It was found that the GPs could improve the mechanical properties of the biocomposites. In addition, the results of moisture uptake and solubility in water of biocomposites showed that water resistance of biocomposites was enhanced by the introduction of GPs. These results suggested that GPs fabricated through an in situ method could be a good candidate for use in biopolymer-based composites.

  2. Low Cost, Low Power, High Sensitivity Magnetometer

    Science.gov (United States)

    2008-12-01

    which are used to measure the small magnetic signals from brain. Other types of vector magnetometers are fluxgate , coil based, and magnetoresistance...concentrator with the magnetometer currently used in Army multimodal sensor systems, the Brown fluxgate . One sees the MEMS fluxgate magnetometer is...Guedes, A.; et al., 2008: Hybrid - LOW COST, LOW POWER, HIGH SENSITIVITY MAGNETOMETER A.S. Edelstein*, James E. Burnette, Greg A. Fischer, M.G

  3. Cavallo's multiplier for in situ generation of high voltage

    Science.gov (United States)

    Clayton, S. M.; Ito, T. M.; Ramsey, J. C.; Wei, W.; Blatnik, M. A.; Filippone, B. W.; Seidel, G. M.

    2018-05-01

    A classic electrostatic induction machine, Cavallo's multiplier, is suggested for in situ production of very high voltage in cryogenic environments. The device is suitable for generating a large electrostatic field under conditions of very small load current. Operation of the Cavallo multiplier is analyzed, with quantitative description in terms of mutual capacitances between electrodes in the system. A demonstration apparatus was constructed, and measured voltages are compared to predictions based on measured capacitances in the system. The simplicity of the Cavallo multiplier makes it amenable to electrostatic analysis using finite element software, and electrode shapes can be optimized to take advantage of a high dielectric strength medium such as liquid helium. A design study is presented for a Cavallo multiplier in a large-scale, cryogenic experiment to measure the neutron electric dipole moment.

  4. In Situ Raman Study of Liquid Water at High Pressure.

    Science.gov (United States)

    Romanenko, Alexandr V; Rashchenko, Sergey V; Goryainov, Sergey V; Likhacheva, Anna Yu; Korsakov, Andrey V

    2018-06-01

    A pressure shift of Raman band of liquid water (H 2 O) may be an important tool for measuring residual pressures in mineral inclusions, in situ barometry in high-pressure cells, and as an indicator of pressure-induced structural transitions in H 2 O. However, there was no consensus as to how the broad and asymmetric water Raman band should be quantitatively described, which has led to fundamental inconsistencies between reported data. In order to overcome this issue, we measured Raman spectra of H 2 O in situ up to 1.2 GPa using a diamond anvil cell, and use them to test different approaches proposed for the description of the water Raman band. We found that the most physically meaningful description of water Raman band is the decomposition into a linear background and three Gaussian components, associated with differently H-bonded H 2 O molecules. Two of these components demonstrate a pronounced anomaly in pressure shift near 0.4 GPa, supporting ideas of structural transition in H 2 O at this pressure. The most convenient approach for pressure calibration is the use of "a linear background + one Gaussian" decomposition (the pressure can be measured using the formula P (GPa) = -0.0317(3)·Δν G (cm -1 ), where Δν G represents the difference between the position of water Raman band, fitted as a single Gaussian, in measured spectrum and spectrum at ambient pressure).

  5. Review of high-sensitivity Radon studies

    Science.gov (United States)

    Wojcik, M.; Zuzel, G.; Simgen, H.

    2017-10-01

    A challenge in many present cutting-edge particle physics experiments is the stringent requirements in terms of radioactive background. In peculiar, the prevention of Radon, a radioactive noble gas, which occurs from ambient air and it is also released by emanation from the omnipresent progenitor Radium. In this paper we review various high-sensitivity Radon detection techniques and approaches, applied in the experiments looking for rare nuclear processes happening at low energies. They allow to identify, quantitatively measure and finally suppress the numerous sources of Radon in the detectors’ components and plants.

  6. The potential of high resolution ultrasonic in-situ methods

    International Nuclear Information System (INIS)

    Schuster, K.

    2010-01-01

    source and receivers and on the applied frequencies. With the help of identified phases in the ultrasonic wave field, their travel times and appropriate amplitudes kinematic and dynamic parameters are derived routinely. The most important are: P-wave velocity (longitudinal or compressional wave velocity (vp)), Sv-wave velocity (vertical polarised transversal or shear wave velocity (vsv), absolute amplitudes of first arrival (P-wave) and Sv-wave onset phases, normalised amplitudes of first arrival (P-wave) and Sv-wave onset phases, apparent frequency of first arrival phases (P-wave) and Sv-wave onset phases, in-situ dynamic elastic Poisson's ratio, in-situ dynamic elastic Young's modulus and in-situ dynamic elastic modulus of rigidity. The main qualities which were detected and/or characterised with the help of these parameters in the past years are: - Degree and extent of EDZ/EdZ. - Long and short term development of EDZ/EdZ (application of repetition measurements). - Borehole disturbed Zones (BdZ). - Small scale rock heterogeneities. - Seismic anisotropy. - Stress orientation via rotational interval velocity measurements. - Determination of dynamic elastic in-situ parameters. Results from repetition measurements showed the high reliability of the methods. Furthermore, in several experiments the ultrasonic methods were combined with other geotechnical or geophysical methods, for example permeability and geo-electrical methods. Results from a seismic anisotropy study at the Mont Terri Rock Laboratory are shown. Two sub-horizontal 2 m long boreholes with a distance of 1 m were used. Nearly 600 different ray paths were analysed. Depending on the angles of the ray paths (60 deg. -300 deg. and 120 deg. -240 deg. ) the P-wave velocities vary between 2600 and 3100 m/s. Lower velocities are supposed to be influenced by the EDZ. (authors)

  7. High sensitivity troponin and valvular heart disease.

    Science.gov (United States)

    McCarthy, Cian P; Donnellan, Eoin; Phelan, Dermot; Griffin, Brian P; Enriquez-Sarano, Maurice; McEvoy, John W

    2017-07-01

    Blood-based biomarkers have been extensively studied in a range of cardiovascular diseases and have established utility in routine clinical care, most notably in the diagnosis of acute coronary syndrome (e.g., troponin) and the management of heart failure (e.g., brain-natriuretic peptide). The role of biomarkers is less well established in the management of valvular heart disease (VHD), in which the optimal timing of surgical intervention is often challenging. One promising biomarker that has been the subject of a number of recent VHD research studies is high sensitivity troponin (hs-cTn). Novel high-sensitivity assays can detect subclinical myocardial damage in asymptomatic individuals. Thus, hs-cTn may have utility in the assessment of asymptomatic patients with severe VHD who do not have a clear traditional indication for surgical intervention. In this state-of-the-art review, we examine the current evidence for hs-cTn as a potential biomarker in the most commonly encountered VHD conditions, aortic stenosis and mitral regurgitation. This review provides a synopsis of early evidence indicating that hs-cTn has promise as a biomarker in VHD. However, the impact of its measurement on clinical practice and VHD outcomes needs to be further assessed in prospective studies before routine clinical use becomes a reality. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Highly sensitive high resolution Raman spectroscopy using resonant ionization methods

    International Nuclear Information System (INIS)

    Owyoung, A.; Esherick, P.

    1984-05-01

    In recent years, the introduction of stimulated Raman methods has offered orders of magnitude improvement in spectral resolving power for gas phase Raman studies. Nevertheless, the inherent weakness of the Raman process suggests the need for significantly more sensitive techniques in Raman spectroscopy. In this we describe a new approach to this problem. Our new technique, which we call ionization-detected stimulated Raman spectroscopy (IDSRS), combines high-resolution SRS with highly-sensitive resonant laser ionization to achieve an increase in sensitivity of over three orders of magnitude. The excitation/detection process involves three sequential steps: (1) population of a vibrationally excited state via stimulated Raman pumping; (2) selective ionization of the vibrationally excited molecule with a tunable uv source; and (3) collection of the ionized species at biased electrodes where they are detected as current in an external circuit

  9. Detection of gelatinolytic activity in developing basement membranes of the mouse embryo head by combining sensitive in situ zymography with immunolabeling.

    Science.gov (United States)

    Gkantidis, Nikolaos; Katsaros, Christos; Chiquet, Matthias

    2012-10-01

    Genetic evidence indicates that the major gelatinases MMP-2 and MMP-9 are involved in mammalian craniofacial development. Since these matrix metalloproteinases are secreted as proenzymes that require activation, their tissue distribution does not necessarily reflect the sites of enzymatic activity. Information regarding the spatial and temporal expression of gelatinolytic activity in the head of the mammalian embryo is sparse. Sensitive in situ zymography with dye-quenched gelatin (DQ-gelatin) has been introduced recently; gelatinolytic activity results in a local increase in fluorescence. Using frontal sections of wild-type mouse embryo heads from embryonic day 14.5-15.5, we optimized and validated a simple double-labeling in situ technique for combining DQ-gelatin zymography with immunofluorescence staining. MMP inhibitors were tested to confirm the specificity of the reaction in situ, and results were compared to standard SDS-gel zymography of tissue extracts. Double-labeling was used to show the spatial relationship in situ between gelatinolytic activity and immunostaining for gelatinases MMP-2 and MMP-9, collagenase 3 (MMP-13) and MT1-MMP (MMP-14), a major activator of pro-gelatinases. Strong gelatinolytic activity, which partially overlapped with MMP proteins, was confirmed for Meckel's cartilage and developing mandibular bone. In addition, we combined in situ zymography with immunostaining for extracellular matrix proteins that are potential gelatinase substrates. Interestingly, gelatinolytic activity colocalized precisely with laminin-positive basement membranes at specific sites around growing epithelia in the developing mouse head, such as the ducts of salivary glands or the epithelial fold between tongue and lower jaw region. Thus, this sensitive method allows to associate, with high spatial resolution, gelatinolytic activity with epithelial morphogenesis in the embryo.

  10. CALDER: High-sensitivity cryogenic light detectors

    International Nuclear Information System (INIS)

    Casali, N.; Bellini, F.; Cardani, L.

    2017-01-01

    The current bolometric experiments searching for rare processes such as neutrinoless double-beta decay or dark matter interaction demand for cryogenic light detectors with high sensitivity, large active area and excellent scalability and radio-purity in order to reduce their background budget. The CALDER project aims to develop such kind of light detectors implementing phonon-mediated Kinetic Inductance Detectors (KIDs). The goal for this project is the realization of a 5 × 5 cm"2 light detector working between 10 and 100mK with a baseline resolution RMS below 20 eV. In this work the characteristics and the performances of the prototype detectors developed in the first project phase will be shown.

  11. High sensitive radiation detector for radiology dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Valente, M.; Malano, F. [Instituto de Fisica Enrique Gaviola, Oficina 102 FaMAF - UNC, Av. Luis Medina Allende, Ciudad Universitaria, 5000 Cordoba (Argentina); Molina, W.; Vedelago, J., E-mail: valente@famac.unc.edu.ar [Laboratorio de Investigaciones e Instrumentacion en Fisica Aplicada a la Medicina e Imagenes por Rayos X, Laboratorio 448 FaMAF - UNC, Ciudad Universitaria, 5000 Cordoba (Argentina)

    2014-08-15

    Fricke solution has a wide range of applications as radiation detector and dosimetry. It is particularly appreciated in terms of relevant comparative advantages, like tissue equivalence when prepared in aqueous media like gel matrix, continuous mapping capability, dose rate recorded and incident direction independence as well as linear dose response. This work presents the development and characterization of a novel Fricke gel system, based on modified chemical compositions making possible its application in clinical radiology. Properties of standard Fricke gel dosimeter for high dose levels are used as starting point and suitable chemical modifications are introduced and carefully investigated in order to attain high resolution for low dose ranges, like those corresponding to radiology interventions. The developed Fricke gel radiation dosimeter system achieves the expected typical dose dependency, actually showing linear response in the dose range from 20 up to 4000 mGy. Systematic investigations including several chemical compositions are carried out in order to obtain a good enough dosimeter response for low dose levels. A suitable composition among those studied is selected as a good candidate for low dose level radiation dosimetry consisting on a modified Fricke solution fixed to a gel matrix containing benzoic acid along with sulfuric acid, ferrous sulfate, xylenol orange and ultra-pure reactive grade water. Dosimeter samples are prepared in standard vials for its in phantom irradiation and further characterization by spectrophotometry measuring visible light transmission and absorbance before and after irradiation. Samples are irradiated by typical kV X-ray tubes and calibrated Farmer type ionization chamber is used as reference to measure dose rates inside phantoms in at vials locations. Once sensitive material composition is already optimized, dose-response curves show significant improvement regarding overall sensitivity for low dose levels. According to

  12. High sensitivity amplifier/discriminator for PWC's

    International Nuclear Information System (INIS)

    Hansen, S.

    1983-01-01

    The facility support group at Fermilab is designing and building a general purpose beam chamber for use in several locations at the laboratory. This pwc has 128 wires per plane spaced 1 mm apart. An initial production of 25 signal planes is anticipated. In proportional chambers, the size of the signal depends exponentially on the charge stored per unit of length along the anode wire. As the wire spacing decreases, the capacitance per unit length decreases, thereby requiring increased applied voltage to restore the necessary charge per unit length. In practical terms, this phenomenon is responsible for difficulties in constructing chambers with less than 2 mm wire spacing. 1 mm chambers, therefore, are frequently operated very near to their breakdown point and/or a high gain gas containing organic compounds such as magic gas is used. This argon/iso-butane mixture has three drawbacks: it is explosive when exposed to the air, it leaves a residue on the wires after extended use and is costly. An amplifier with higher sensitivity would reduce the problems associated with operating chambers with small wire spacings and allow them to be run a safe margin below their breakdown voltage even with an inorganic gas mixture such as argon/CO2, this eliminating the need to use magic gas. Described here is a low cost amplifier with a usable threshold of less than 0.5 μA. Data on the performance of this amplifier/discriminator in operation on a prototype beam chamber are given. This data shows the advantages of the high sensitivity of this design

  13. High sensitive radiation detector for radiology dosimetry

    International Nuclear Information System (INIS)

    Valente, M.; Malano, F.; Molina, W.; Vedelago, J.

    2014-08-01

    Fricke solution has a wide range of applications as radiation detector and dosimetry. It is particularly appreciated in terms of relevant comparative advantages, like tissue equivalence when prepared in aqueous media like gel matrix, continuous mapping capability, dose rate recorded and incident direction independence as well as linear dose response. This work presents the development and characterization of a novel Fricke gel system, based on modified chemical compositions making possible its application in clinical radiology. Properties of standard Fricke gel dosimeter for high dose levels are used as starting point and suitable chemical modifications are introduced and carefully investigated in order to attain high resolution for low dose ranges, like those corresponding to radiology interventions. The developed Fricke gel radiation dosimeter system achieves the expected typical dose dependency, actually showing linear response in the dose range from 20 up to 4000 mGy. Systematic investigations including several chemical compositions are carried out in order to obtain a good enough dosimeter response for low dose levels. A suitable composition among those studied is selected as a good candidate for low dose level radiation dosimetry consisting on a modified Fricke solution fixed to a gel matrix containing benzoic acid along with sulfuric acid, ferrous sulfate, xylenol orange and ultra-pure reactive grade water. Dosimeter samples are prepared in standard vials for its in phantom irradiation and further characterization by spectrophotometry measuring visible light transmission and absorbance before and after irradiation. Samples are irradiated by typical kV X-ray tubes and calibrated Farmer type ionization chamber is used as reference to measure dose rates inside phantoms in at vials locations. Once sensitive material composition is already optimized, dose-response curves show significant improvement regarding overall sensitivity for low dose levels. According to

  14. On the cross-sensitivity between water vapor mixing ratio and stable isotope measurements of in-situ analyzers

    KAUST Repository

    Parkes, Stephen

    2015-04-01

    In recent years there has been an increasing amount of water vapor stable isotope data collected using in-situ instrumentation. A number of papers have characterized the performance of these in-situ analyzers and suggested methods for calibrating raw measurements. The cross-sensitivity of the isotopic measurements on the mixing ratio has been shown to be a major uncertainty and a variety of techniques have been suggested to characterize this inaccuracy. However, most of these are based on relating isotopic ratios to water vapor mixing ratios from in-situ analyzers when the mixing ratio is varied and the isotopic composition kept constant. An additional correction for the span of the isotopic ratio scale is then applied by measuring different isotopic standards. Here we argue that the water vapor cross-sensitivity arises from different instrument responses (span and offset) of the parent H2O isotope and the heavier isotopes, rather than spectral overlap that could cause a true variation in the isotopic ratio with mixing ratio. This is especially relevant for commercial laser optical instruments where absorption lines are well resolved. Thus, the cross-sensitivity determined using more conventional techniques is dependent on the isotopic ratio of the standard used for the characterization, although errors are expected to be small. Consequently, the cross-sensitivity should be determined by characterizing the span and zero offset of each isotope mixing ratio. In fact, this technique makes the span correction for the isotopic ratio redundant. In this work we model the impact of changes in the span and offset of the heavy and light isotopes and illustrate the impact on the cross-sensitivity of the isotopic ratios on water vapor. This clearly shows the importance of determining the zero offset for the two isotopes. The cross-sensitivity of the isotopic ratios on water vapor is then characterized by determining the instrument response for the individual isotopes for a

  15. On the cross-sensitivity between water vapor mixing ratio and stable isotope measurements of in-situ analyzers

    KAUST Repository

    Parkes, Stephen; Wang,  Lixin; McCabe, Matthew

    2015-01-01

    In recent years there has been an increasing amount of water vapor stable isotope data collected using in-situ instrumentation. A number of papers have characterized the performance of these in-situ analyzers and suggested methods for calibrating raw measurements. The cross-sensitivity of the isotopic measurements on the mixing ratio has been shown to be a major uncertainty and a variety of techniques have been suggested to characterize this inaccuracy. However, most of these are based on relating isotopic ratios to water vapor mixing ratios from in-situ analyzers when the mixing ratio is varied and the isotopic composition kept constant. An additional correction for the span of the isotopic ratio scale is then applied by measuring different isotopic standards. Here we argue that the water vapor cross-sensitivity arises from different instrument responses (span and offset) of the parent H2O isotope and the heavier isotopes, rather than spectral overlap that could cause a true variation in the isotopic ratio with mixing ratio. This is especially relevant for commercial laser optical instruments where absorption lines are well resolved. Thus, the cross-sensitivity determined using more conventional techniques is dependent on the isotopic ratio of the standard used for the characterization, although errors are expected to be small. Consequently, the cross-sensitivity should be determined by characterizing the span and zero offset of each isotope mixing ratio. In fact, this technique makes the span correction for the isotopic ratio redundant. In this work we model the impact of changes in the span and offset of the heavy and light isotopes and illustrate the impact on the cross-sensitivity of the isotopic ratios on water vapor. This clearly shows the importance of determining the zero offset for the two isotopes. The cross-sensitivity of the isotopic ratios on water vapor is then characterized by determining the instrument response for the individual isotopes for a

  16. High sensitivity thermal sensors on insulating diamond

    Energy Technology Data Exchange (ETDEWEB)

    Job, R. [Fernuniversitaet Hagen (Gesamthochschule) (Germany). Electron. Devices; Denisenko, A.V. [Fernuniversitaet Hagen (Gesamthochschule) (Germany). Electron. Devices; Zaitsev, A.M. [Fernuniversitaet Hagen (Gesamthochschule) (Germany). Electron. Devices; Melnikov, A.A. [Belarussian State Univ., Minsk (Belarus). HEII and FD; Werner, M. [VDI/VDE-IT, Teltow (Germany); Fahrner, W.R. [Fernuniversitaet Hagen (Gesamthochschule) (Germany). Electron. Devices

    1996-12-15

    Diamond is a promising material to develop sensors for applications in harsh environments. To increase the sensitivity of diamond temperature sensors the effect of thermionic hole emission (TE) over an energetic barrier formed in the interface between highly boron-doped p-type and intrinsic insulating diamond areas has been suggested. To study the TE of holes a p-i-p diode has been fabricated and analyzed by electrical measurements in the temperature range between 300 K and 700 K. The experimental results have been compared with numerical simulations of its electrical characteristics. Based on a model of the thermionic emission of carriers into an insulator it has been suggested that the temperature sensitivity of the p-i-p diode on diamond is strongly affected by the re-emission of holes from a group of donor-like traps located at a level of 0.7-1.0 eV above the valence band. The mechanism of thermal activation of the current includes a spatial redistribution of the potential, which results in the TE regime from a decrease of the immobilized charge of the ionized traps within the i-zone of the diode and the correspondent lowering of the forward biased barrier. The characteristics of the p-i-p diode were studied with regard to temperature sensor applications. The temperature coefficient of resistance (TCR=-0.05 K{sup -1}) for temperatures above 600 K is about four times larger than the maximal attainable TCR for conventional boron-doped diamond resistors. (orig.)

  17. In-situ high efficiency filter testing at AEE Winfrith

    International Nuclear Information System (INIS)

    Fraser, D.C.

    1977-01-01

    This paper discusses experience in the testing of high efficiency filters in a variety of reactor and plant installations at AEE Winfrith. There is rarely any concern about the effectiveness of the filter as supplied by any reputable manufacturer. Experience has shown there is a need to check for defects in the installation of filters which could lead to by-passing of aerosols and it is desirable to perform periodical re-tests to ensure that no subsequent deterioration occurs. It is important to use simple, portable apparatus for such tests; methods based on the use of sodium chloride aerosols, although suitable for the testing of filters prior to installation, involve apparatus which is too bulky for in-situ testing. At Winfrith a double automatic Pollak counter has been developed and used routinely since 1970. The aerosol involved has a particle size far smaller than the size most likely to penetrate intact filters, but this is irrelevant when one is primarily interested in particles which by-pass the filter. Comparisons with other methods of testing filters will be described. There is remarkably good agreement between the efficiency of the filter installation as measured by a Pollak counter compared with techniques involving aerosols of sodium chloride and Dioctyl Phthalate (DOP), presumably because the leakage around the filter is independent of particle size

  18. In situ high-resolution thermal microscopy on integrated circuits.

    Science.gov (United States)

    Zhuo, Guan-Yu; Su, Hai-Ching; Wang, Hsien-Yi; Chan, Ming-Che

    2017-09-04

    The miniaturization of metal tracks in integrated circuits (ICs) can cause abnormal heat dissipation, resulting in electrostatic discharge, overvoltage breakdown, and other unwanted issues. Unfortunately, locating areas of abnormal heat dissipation is limited either by the spatial resolution or imaging acquisition speed of current thermal analytical techniques. A rapid, non-contact approach to the thermal imaging of ICs with sub-μm resolution could help to alleviate this issue. In this work, based on the intensity of the temperature-dependent two-photon fluorescence (TPF) of Rhodamine 6G (R6G) material, we developed a novel fast and non-invasive thermal microscopy with a sub-μm resolution. Its application to the location of hotspots that may evolve into thermally induced defects in ICs was also demonstrated. To the best of our knowledge, this is the first study to present high-resolution 2D thermal microscopic images of ICs, showing the generation, propagation, and distribution of heat during its operation. According to the demonstrated results, this scheme has considerable potential for future in situ hotspot analysis during the optimization stage of IC development.

  19. Transportable high sensitivity small sample radiometric calorimeter

    International Nuclear Information System (INIS)

    Wetzel, J.R.; Biddle, R.S.; Cordova, B.S.; Sampson, T.E.; Dye, H.R.; McDow, J.G.

    1998-01-01

    A new small-sample, high-sensitivity transportable radiometric calorimeter, which can be operated in different modes, contains an electrical calibration method, and can be used to develop secondary standards, will be described in this presentation. The data taken from preliminary tests will be presented to indicate the precision and accuracy of the instrument. The calorimeter and temperature-controlled bath, at present, require only a 30-in. by 20-in. tabletop area. The calorimeter is operated from a laptop computer system using unique measurement module capable of monitoring all necessary calorimeter signals. The calorimeter can be operated in the normal calorimeter equilibration mode, as a comparison instrument, using twin chambers and an external electrical calibration method. The sample chamber is 0.75 in (1.9 cm) in diameter by 2.5 in. (6.35 cm) long. This size will accommodate most 238 Pu heat standards manufactured in the past. The power range runs from 0.001 W to <20 W. The high end is only limited by sample size

  20. Highly sensitive detection of a current ripple

    International Nuclear Information System (INIS)

    Aoki, Takashi; Gushiken, Tutomu; Nishikigouri, Kazutaka; Kumada, Masayuki.

    1996-01-01

    In the HIMAC, there are six thyristor-controlled power sources for driving two synchrotrons. These power sources are the three-output terminal power sources which are equipped with positive output, negative output and neutral point for the common mode countermeasures. As electromagnet circuits are connected to the three-output terminal power sources, those are three-line type. In the inside of the power source circuits controlled by thyristors, there is the oscillation peculiar to the power sources, and the variation of voltage induces current spikes. This time, in order to assess the results of the common mode countermeasures in the power source and electromagnet circuits, as one method of cross-check, it is considered that since electromagnet current flows being divided to the bridging resistance and the coil, if attention is paid to the current on bridging resistance side, the ripple components of common mode and normal mode can be detected with high sensitivity, and this was verified. The present state of heightening the performance of synchrotron power sources is explained. The cross-check of the method of assessing the performance of electromagnet power sources is reported. The method of measuring ripple current and the results of the measurement are reported. (K.I.)

  1. Development of high sensitivity radon detectors

    CERN Document Server

    Takeuchi, Y; Kajita, T; Tasaka, S; Hori, H; Nemoto, M; Okazawa, H

    1999-01-01

    High sensitivity detectors for radon in air and in water have been developed. We use electrostatic collection and a PIN photodiode for these detectors. Calibration systems have been also constructed to obtain collection factors. As a result of the calibration study, the absolute humidity dependence of the radon detector for air is clearly observed in the region less than about 1.6 g/m sup 3. The calibration factors of the radon detector for air are 2.2+-0.2 (counts/day)/(mBq/m sup 3) at 0.08 g/m sup 3 and 0.86+-0.06 (counts/day)/(mBq/m sup 3) at 11 g/m sup 3. The calibration factor of the radon detector for water is 3.6+-0.5 (counts/day)/(mBq/m sup 3). The background level of the radon detector for air is 2.4+-1.3 counts/day. As a result, one standard deviation excess of the signal above the background of the radon detector for air should be possible for 1.4 mBq/m sup 3 in a one-day measurement at 0.08 g/m sup 3.

  2. Novel High Temperature Materials for In-Situ Sensing Devices

    Energy Technology Data Exchange (ETDEWEB)

    Florian Solzbacher; Anil Virkar; Loren Rieth; Srinivasan Kannan; Xiaoxin Chen; Hannwelm Steinebach

    2009-12-31

    The overriding goal of this project was to develop gas sensor materials and systems compatible with operation at temperatures from 500 to 700 C. Gas sensors operating at these temperatures would be compatible with placement in fossil-energy exhaust streams close to the combustion chamber, and therefore have advantages for process regulation, and feedback for emissions controls. The three thrusts of our work included investigating thin film gas sensor materials based on metal oxide materials and electroceramic materials, and also development of microhotplate devices to support the gas sensing films. The metal oxide materials NiO, In{sub 2}O{sub 3}, and Ga{sub 2}O{sub 3} were investigated for their sensitivity to H{sub 2}, NO{sub x}, and CO{sub 2}, respectively, at high temperatures (T > 500 C), where the sensing properties of these materials have received little attention. New ground was broken in achieving excellent gas sensor responses (>10) for temperatures up to 600 C for NiO and In{sub 2}O{sub 3} materials. The gas sensitivity of these materials was decreasing as temperatures increased above 500 C, which indicates that achieving strong sensitivities with these materials at very high temperatures (T {ge} 650 C) will be a further challenge. The sensitivity, selectivity, stability, and reliability of these materials were investigated across a wide range of deposition conditions, temperatures, film thickness, as using surface active promoter materials. We also proposed to study the electroceramic materials BaZr{sub (1-x)}Y{sub x}O{sub (3-x/2)} and BaCe{sub (2-x)}Ca{sub x}S{sub (4-x/2)} for their ability to detect H{sub 2}O and H{sub 2}S, respectively. This report focuses on the properties and gas sensing characteristics of BaZr{sub (1-x)}Y{sub x}O{sub (3-x/2)} (Y-doped BaZrO{sub 3}), as significant difficulties were encounter in generating BaCe{sub (2-x)}Ca{sub x}S{sub (4-x/2)} sensors. Significant new results were achieved for Y-doped BaZrO{sub 3}, including

  3. High sensitivity MOSFET-based neutron dosimetry

    International Nuclear Information System (INIS)

    Fragopoulou, M.; Konstantakos, V.; Zamani, M.; Siskos, S.; Laopoulos, T.; Sarrabayrouse, G.

    2010-01-01

    A new dosemeter based on a metal-oxide-semiconductor field effect transistor sensitive to both neutrons and gamma radiation was manufactured at LAAS-CNRS Laboratory, Toulouse, France. In order to be used for neutron dosimetry, a thin film of lithium fluoride was deposited on the surface of the gate of the device. The characteristics of the dosemeter, such as the dependence of its response to neutron dose and dose rate, were investigated. The studied dosemeter was very sensitive to gamma rays compared to other dosemeters proposed in the literature. Its response in thermal neutrons was found to be much higher than in fast neutrons and gamma rays.

  4. Environmental Sensitivity in Children: Development of the Highly Sensitive Child Scale and Identification of Sensitivity Groups

    Science.gov (United States)

    Pluess, Michael; Assary, Elham; Lionetti, Francesca; Lester, Kathryn J.; Krapohl, Eva; Aron, Elaine N.; Aron, Arthur

    2018-01-01

    A large number of studies document that children differ in the degree they are shaped by their developmental context with some being more sensitive to environmental influences than others. Multiple theories suggest that "Environmental Sensitivity" is a common trait predicting the response to negative as well as positive exposures.…

  5. High sensitivity optical measurement of skin gloss

    NARCIS (Netherlands)

    Ezerskaia, A.; Ras, Arno; Bloemen, Pascal; Pereira, S.F.; Urbach, Paul; Varghese, Babu

    2017-01-01

    We demonstrate a low-cost optical method for measuring the gloss properties with improved sensitivity in the low gloss regime, relevant for skin gloss properties. The gloss estimation method is based on, on the one hand, the slope of the intensity gradient in the transition regime between

  6. Titanate nanotubes sensitized with silver nanoparticles: Synthesis, characterization and in-situ pollutants photodegradation

    Energy Technology Data Exchange (ETDEWEB)

    Barrocas, B.; Nunes, C.D. [Centro de Química e Bioquímica, Faculdade de Ciências, Universidade de Lisboa, 1749-016 Lisboa (Portugal); Carvalho, M.L. [LIBPhys-UNL, Laboratório de Instrumentação, Engenharia Biomédica e Física da Radiação and Departamento de Física da Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica (Portugal); Monteiro, O.C., E-mail: ocmonteiro@ciencias.ulisboa.pt [Centro de Química e Bioquímica, Faculdade de Ciências, Universidade de Lisboa, 1749-016 Lisboa (Portugal)

    2016-11-01

    Highlights: • Combination of titanate nanotubes with crystalline silver nanoparticles is described. • AgHTNT demonstrated high photocatalytic activity for hydroxyl radical production. • AgHTNT exhibits the best photocatalytic activity for phenol removal. • Recycling does not affect AgHTNT photocatalytic performance. • Silver nanoparticles growth continues during several irradiation cycles. - Abstract: In this work, titanate nanotubes were modified with silver nanoparticles to produce new nanocomposite materials with enhanced photocatalytic activity for phenol removal. The TNTs were produced using a hydrothermal approach and, after being submitted to an Ag{sup +} exchange process, metallic Ag nanoparticles were obtained over the nanotubes surface. The prepared materials were structural, morphological and optical characterized by X-ray powder diffraction, micro X-ray fluorescence, transmission electron microscopy, diffused reflectance spectroscopy and X-ray photoelectron spectroscopy. The characterization results indicate that Ag{sup +} was immobilized not only in the nanotubes external surface but mainly in the TiO{sub 6} interlayers space. The application of this new nanocomposite material on photocatalytic degradation of pollutants was investigated. First, the evaluation of hydroxyl radical formation, using the terephthalic acid as a probe was studied. The photocatalytic activity of the sensitized materials for phenol degradation was afterwards evaluated. The results show that the nanocomposite sample is the best catalyst, achieving 98.0% photodegradation efficiency of a 0.2 mM phenol solution within 20 min under UV–vis radiation. The reusability of the prepared samples as photocatalysts was evaluated in four successive degradation assays, using fresh phenol solutions. The sensitized sample demonstrated excellent catalytic reusability ability, without loss of photochemical stability. The structural and morphological characterization during these

  7. High sensitivity optical measurement of skin gloss

    OpenAIRE

    Ezerskaia, Anna; Ras, Arno; Bloemen, Pascal; Pereira, Silvania F.; Urbach, H. Paul; Varghese, Babu

    2017-01-01

    We demonstrate a low-cost optical method for measuring the gloss properties with improved sensitivity in the low gloss regime, relevant for skin gloss properties. The gloss estimation method is based on, on the one hand, the slope of the intensity gradient in the transition regime between specular and diffuse reflection and on the other on the sum over the intensities of pixels above threshold, derived from a camera image obtained using unpolarized white light illumination. We demonstrate the...

  8. High sensitivity optical measurement of skin gloss.

    Science.gov (United States)

    Ezerskaia, Anna; Ras, Arno; Bloemen, Pascal; Pereira, Silvania F; Urbach, H Paul; Varghese, Babu

    2017-09-01

    We demonstrate a low-cost optical method for measuring the gloss properties with improved sensitivity in the low gloss regime, relevant for skin gloss properties. The gloss estimation method is based on, on the one hand, the slope of the intensity gradient in the transition regime between specular and diffuse reflection and on the other on the sum over the intensities of pixels above threshold, derived from a camera image obtained using unpolarized white light illumination. We demonstrate the improved sensitivity of the two proposed methods using Monte Carlo simulations and experiments performed on ISO gloss calibration standards with an optical prototype. The performance and linearity of the method was compared with different professional gloss measurement devices based on the ratio of specular to diffuse intensity. We demonstrate the feasibility for in-vivo skin gloss measurements by quantifying the temporal evolution of skin gloss after application of standard paraffin cream bases on skin. The presented method opens new possibilities in the fields of cosmetology and dermatopharmacology for measuring the skin gloss and resorption kinetics and the pharmacodynamics of various external agents.

  9. Improving the Power Conversion Efficiency of Carbon Quantum Dot-Sensitized Solar Cells by Growing the Dots on a TiO2 Photoanode In Situ

    Directory of Open Access Journals (Sweden)

    Quanxin Zhang

    2017-05-01

    Full Text Available Dye-sensitized solar cells (DSSCs are highly promising since they can potentially solve global energy issues. The development of new photosensitizers is the key to fully realizing perspectives proposed to DSSCs. Being cheap and nontoxic, carbon quantum dots (CQDs have emerged as attractive candidates for this purpose. However, current methodologies to build up CQD-sensitized solar cells (CQDSCs result in an imperfect apparatus with extremely low power conversion efficiencies (PCEs. Herein, we present a simple strategy of growing carbon quantum dots (CQDs onto TiO2 surfaces in situ. The CQDs/TiO2 hybridized photoanode was then used to construct solar cell with an improved PCE of 0.87%, which is higher than all of the reported CQDSCs adopting the simple post-adsorption method. This result indicates that an in situ growing strategy has great advantages in terms of optimizing the performance of CQDSCs. In addition, we have also found that the mechanisms dominating the performance of CQDSCs are different from those behind the solar cells using inorganic semiconductor quantum dots (ISQDs as the photosensitizers, which re-confirms the conclusion that the characteristics of CQDs differ from those of ISQDs.

  10. Regulatory pathway analysis by high-throughput in situ hybridization.

    Directory of Open Access Journals (Sweden)

    Axel Visel

    2007-10-01

    Full Text Available Automated in situ hybridization enables the construction of comprehensive atlases of gene expression patterns in mammals. Such atlases can become Web-searchable digital expression maps of individual genes and thus offer an entryway to elucidate genetic interactions and signaling pathways. Towards this end, an atlas housing approximately 1,000 spatial gene expression patterns of the midgestation mouse embryo was generated. Patterns were textually annotated using a controlled vocabulary comprising >90 anatomical features. Hierarchical clustering of annotations was carried out using distance scores calculated from the similarity between pairs of patterns across all anatomical structures. This process ordered hundreds of complex expression patterns into a matrix that reflects the embryonic architecture and the relatedness of patterns of expression. Clustering yielded 12 distinct groups of expression patterns. Because of the similarity of expression patterns within a group, members of each group may be components of regulatory cascades. We focused on the group containing Pax6, an evolutionary conserved transcriptional master mediator of development. Seventeen of the 82 genes in this group showed a change of expression in the developing neocortex of Pax6-deficient embryos. Electromobility shift assays were used to test for the presence of Pax6-paired domain binding sites. This led to the identification of 12 genes not previously known as potential targets of Pax6 regulation. These findings suggest that cluster analysis of annotated gene expression patterns obtained by automated in situ hybridization is a novel approach for identifying components of signaling cascades.

  11. The selectively bred high alcohol sensitivity (HAS) and low alcohol sensitivity (LAS) rats differ in sensitivity to nicotine.

    Science.gov (United States)

    de Fiebre, NancyEllen C; Dawson, Ralph; de Fiebre, Christopher M

    2002-06-01

    Studies in rodents selectively bred to differ in alcohol sensitivity have suggested that nicotine and ethanol sensitivities may cosegregate during selective breeding. This suggests that ethanol and nicotine sensitivities may in part be genetically correlated. Male and female high alcohol sensitivity (HAS), control alcohol sensitivity, and low alcohol sensitivity (LAS) rats were tested for nicotine-induced alterations in locomotor activity, body temperature, and seizure activity. Plasma and brain levels of nicotine and its primary metabolite, cotinine, were measured in these animals, as was the binding of [3H]cytisine, [3H]epibatidine, and [125I]alpha-bungarotoxin in eight brain regions. Both replicate HAS lines were more sensitive to nicotine-induced locomotor activity depression than the replicate LAS lines. No consistent HAS/LAS differences were seen on other measures of nicotine sensitivity; however, females were more susceptible to nicotine-induced seizures than males. No HAS/LAS differences in nicotine or cotinine levels were seen, nor were differences seen in the binding of nicotinic ligands. Females had higher levels of plasma cotinine and brain nicotine than males but had lower brain cotinine levels than males. Sensitivity to a specific action of nicotine cosegregates during selective breeding for differential sensitivity to a specific action of ethanol. The differential sensitivity of the HAS/LAS rats is due to differences in central nervous system sensitivity and not to pharmacokinetic differences. The differential central nervous system sensitivity cannot be explained by differences in the numbers of nicotinic receptors labeled in ligand-binding experiments. The apparent genetic correlation between ethanol and nicotine sensitivities suggests that common genes modulate, in part, the actions of both ethanol and nicotine and may explain the frequent coabuse of these agents.

  12. In situ neutron diffraction studies of high density amorphous ice under pressure

    International Nuclear Information System (INIS)

    Klotz, Stefan; Straessle, Th; Saitta, A M; Rousse, G; Hamel, G; Nelmes, R J; Loveday, J S; Guthrie, M

    2005-01-01

    We review recent in situ neutron diffraction studies on the structural pressure dependence and the recrystallization of dense amorphous ices up to 2 GPa. Progress in high pressure techniques and data analysis methods allows the reliable determination of all three partial structure factors of amorphous ice under pressure. The strong pressure dependence of the g OO (r) correlation function shows that the isothermal compression of high density amorphous ice (HDA) at 100 K is achieved by a contraction (∼ 20%) of the second-neighbour coordination shell leading to a strong increase in coordination. The g DD (r) and g OD (r) structure factors are, in contrast, only weakly sensitive to pressure. These data allow a comparison with structural features of the recently reported 'very high density amorphous ice' (VHDA) which indicates that VHDA at ambient pressure is very similar to compressed HDA, at least up to the second-neighbour shell. The recrystallization of HDA has been investigated in the range 0.3-2 GPa. It is shown that hydrogen-disordered phases are produced which normally grow only from the liquid, such as ice XII, and in particular ice IV. These findings are in good agreement with results on quench-recovered samples

  13. High-Sensitivity GaN Microchemical Sensors

    Science.gov (United States)

    Son, Kyung-ah; Yang, Baohua; Liao, Anna; Moon, Jeongsun; Prokopuk, Nicholas

    2009-01-01

    Systematic studies have been performed on the sensitivity of GaN HEMT (high electron mobility transistor) sensors using various gate electrode designs and operational parameters. The results here show that a higher sensitivity can be achieved with a larger W/L ratio (W = gate width, L = gate length) at a given D (D = source-drain distance), and multi-finger gate electrodes offer a higher sensitivity than a one-finger gate electrode. In terms of operating conditions, sensor sensitivity is strongly dependent on transconductance of the sensor. The highest sensitivity can be achieved at the gate voltage where the slope of the transconductance curve is the largest. This work provides critical information about how the gate electrode of a GaN HEMT, which has been identified as the most sensitive among GaN microsensors, needs to be designed, and what operation parameters should be used for high sensitivity detection.

  14. Comparison of Fluorescence In Situ Hybridization and Chromogenic In Situ Hybridization for Low and High Throughput HER2 Genetic Testing

    Science.gov (United States)

    Poulsen, Tim S.; Espersen, Maiken L. M.; Kofoed, Vibeke; Dabetic, Tanja; Høgdall, Estrid; Balslev, Eva

    2013-01-01

    The purpose was to evaluate and compare 5 different HER2 genetic assays with different characteristics that could affect the performance to analyze the human epidermal growth factor 2 (HER2) gene copy number under low and high throughput conditions. The study included 108 tissue samples from breast cancer patients with HER2 immunohistochemistry (IHC) results scored as 0/1+, 2+, and 3+. HER2 genetic status was analysed using chromogenic in situ hybridization (CISH) and fluorescence in situ hybridization (FISH). Scoring results were documented through digital image analysis. The cancer region of interest was identified from a serial H&E stained slide following tissue cores were transferred to a tissue microarrays (TMA). When using TMA in a routine flow, all patients will be tested for HER2 status with IHC followed by CISH or FISH, thereby providing individual HER2 results. In conclusion, our results show that the differences between the HER2 genetic assays do not have an effect on the analytic performance and the CISH technology is superior to high throughput HER2 genetic testing due to scanning speed, while the IQ-FISH may still be a choice for fast low throughput HER2 genetic testing. PMID:24383005

  15. Development of a highly sensitive lithium fluoride thermoluminescence dosimeter

    International Nuclear Information System (INIS)

    Moraes da Silva, Teresinha de; Campos, Leticia Lucente

    1995-01-01

    In recent times, LiF: Mg, Cu, P thermoluminescent phosphor has been increasingly in use for radiation monitoring due its high sensitivity and ease of preparation. The Dosimetric Materials Production Laboratory of IPEN, (Nuclear Energy Institute) has developed a simple method to obtain high sensitivity LiF. The preparation method is described. (author). 4 refs., 1 fig., 1 tab

  16. Triggers for a high sensitivity charm experiment

    International Nuclear Information System (INIS)

    Christian, D.C.

    1994-07-01

    Any future charm experiment clearly should implement an E T trigger and a μ trigger. In order to reach the 10 8 reconstructed charm level for hadronic final states, a high quality vertex trigger will almost certainly also be necessary. The best hope for the development of an offline quality vertex trigger lies in further development of the ideas of data-driven processing pioneered by the Nevis/U. Mass. group

  17. In situ health monitoring for bogie systems of CRH380 train on Beijing-Shanghai high-speed railway

    Science.gov (United States)

    Hong, Ming; Wang, Qiang; Su, Zhongqing; Cheng, Li

    2014-04-01

    Based on the authors' research efforts over the years, an in situ structural health monitoring (SHM) technique taking advantage of guided elastic waves has been developed and deployed via an online diagnosis system. The technique and the system were recently implemented on China's latest high-speed train (CRH380CL) operated on Beijing-Shanghai High-Speed Railway. The system incorporated modularized components including active sensor network, active wave generation, multi-channel data acquisition, signal processing, data fusion, and results presentation. The sensor network, inspired by a new concept—"decentralized standard sensing", was integrated into the bogie frames during the final assembly of CRH380CL, to generate and acquire bogie-guided ultrasonic waves, from which a wide array of signal features were extracted. Fusion of signal features through a diagnostic imaging algorithm led to a graphic illustration of the overall health state of the bogie in a real-time and intuitive manner. The in situ experimentation covered a variety of high-speed train operation events including startup, acceleration/deceleration, full-speed operation (300 km/h), emergency braking, track change, as well as full stop. Mock-up damage affixed to the bogie was identified quantitatively and visualized in images. This in situ testing has demonstrated the feasibility, effectiveness, sensitivity, and reliability of the developed SHM technique and the system towards real-world applications.

  18. In situ high-pressure measurement of crystal solubility by using neutron diffraction

    Science.gov (United States)

    Chen, Ji; Hu, Qiwei; Fang, Leiming; He, Duanwei; Chen, Xiping; Xie, Lei; Chen, Bo; Li, Xin; Ni, Xiaolin; Fan, Cong; Liang, Akun

    2018-05-01

    Crystal solubility is one of the most important thermo-physical properties and plays a key role in industrial applications, fundamental science, and geoscientific research. However, high-pressure in situ measurements of crystal solubility remain very challenging. Here, we present a method involving high-pressure neutron diffraction for making high-precision in situ measurements of crystal solubility as a function of pressure over a wide range of pressures. For these experiments, we designed a piston-cylinder cell with a large chamber volume for high-pressure neutron diffraction. The solution pressures are continuously monitored in situ based on the equation of state of the sample crystal. The solubility at a high pressure can be obtained by applying a Rietveld quantitative multiphase analysis. To evaluate the proposed method, we measured the high-pressure solubility of NaCl in water up to 610 MPa. At a low pressure, the results are consistent with the previous results measured ex situ. At a higher pressure, more reliable data could be provided by using an in situ high-pressure neutron diffraction method.

  19. In-situ SCC observation on thermally-sensitized type 304 stainless steel irradiated to 1 x 10{sup 25} n/m{sup 2}

    Energy Technology Data Exchange (ETDEWEB)

    Nakano, J.; Nemoto, Y.; Tsukada, T.; Usami, K. [Japan Atomic Energy Agency, Tokai-mura, Naga-gun, Ibaraki-ken (Japan); Hide, K. [Central Research Institute of Electric Power Industry, Yokosuka-shi, Kanagawa-ken (Japan)

    2007-07-01

    Full text of publication follows: Irradiation assisted stress corrosion cracking (IASCC) is concerned as being one of the specific problems for water-cooled first wall/blanket components in the design activity of international thermonuclear experimental reactor (ITER). To examine the crack initiation and growth behaviors of IASCC, in-situ observation on gage length of specimens was conducted during slow strain rate tests (SSRT) in high temperature water. Results from in-situ observation on Type 304 stainless steel (SS) irradiated to 1.0 x 10{sup 26} n/m{sup 2} have been reported already. Type 304 SS was subjected to a solution annealing (SA), a thermally sensitization (TS) or a cold working (CW, 20%) and irradiated to 1.0 x 10{sup 25} n/m{sup 2} in the Japan Materials Testing Reactor (JMTR). After neutron irradiation, SSRT for the specimens was conducted in oxygenated high purity water at 561 K. The gage length of the specimen was observed through a window equipped on an autoclave during the SSRT. Subsequently, fracture surface examination was performed using a scanning electron microscope (SEM). In fracture surface examination of the specimens irradiated to 1.0 x 10{sup 25} n/m{sup 2}, almost entire intergranular stress corrosion cracking (IGSCC) was exhibited for the TS material while mixtures of transgranular stress corrosion cracking (TGSCC) and ductile dimple fracture were observed for the SA and the CW materials. Although crack initiation was observed immediately after maximum stress for the CW irradiated to 1.0 x 10{sup 26} n/m{sup 2}, crack initiation was observed immediately before maximum stress (99% of maximum stress) for the CW irradiated to 1.0 x 10{sup 25} n/m{sup 2} in in-situ observation. (authors)

  20. Cost and sensitivity analysis for uranium in situ leach mining. Open file report Oct 79-Mar 81

    International Nuclear Information System (INIS)

    Toth, G.W.; Annett, J.R.

    1981-03-01

    This report presents the results of an assessment of uranium in situ leach mining costs through the application of process engineering and discounted cash flow analysis procedures. A computerized costing technique was developed to facilitate rapid cost analyses. Applications of the cost model will generate mine life capital and operating costs as well as solve for economic production cost per pound U 3 O 8 . Conversely, rate of return may be determined subject to a known selling price. The data bases of the cost model were designed to reflect variations in Texas versus Wyoming site applications. The results of applying the model under numerous ore deposit, operating, well field, and extraction plant conditions for Texas and Wyoming are summarized in the report. Sensitivity analysis of changes in key project parameters have also been tested and are included

  1. In Situ Observation of Gypsum-Anhydrite Transition at High Pressure and High Temperature

    Institute of Scientific and Technical Information of China (English)

    LIU Chuan-Jiang; ZHENG Hai-Fei

    2012-01-01

    An in-situ Raman spectroscopic study of gypsum-anhydrite transition under a saturated water condition at high pressure and high temperature is performed using a hydrothermal diamond anvil cell (HDAC).The experimental results show that gypsum dissolvs in water at ambient temperature and above 496 MPa.With increasing temperature,the anhydrite (CaSO4) phase precipitates at 250 320℃ in the pressure range of 1.0 1.5 GPa,indicating that under a saturated water condition,both stable conditions of pressure and temperature and high levels of Ca and SO4 ion concentrations in aqueous solution are essential for the formation of anhydrite.A linear relationship between the pressure and temperature for the precipitation of anhydrite is established as P(GPa) =0.0068T - 0.7126 (250℃≤T≤320℃).Anhydrite remained stable during rapid cooling of the sample chamber,showing that the gypsum-anhydrite transition involving both dissolution and precipitation processes is irreversible at high pressure and high temperature.%An in-situ Raman spectroscopic study of gypsum-anhydrite transition under a saturated water condition at high pressure and high temperature is performed using a hydrothermal diamond anvil cell (HDAC). The experimental results show that gypsum dissolvs in water at ambient temperature and above 496 Mpa. With increasing temperature, the anhydrite (CaSO4) phase precipitates at 250-320℃ in the pressure range of 1.0-1.5 Gpa, indicating that under a saturated water condition, both stable conditions of pressure and temperature and high levels of Ca and SO4 ion concentrations in aqueous solution are essential for the formation of anhydrite. A linear relationship between the pressure and temperature for the precipitation of anhydrite is established as P(Gpa) = 0.0068T - 0.7126 (250℃≤T≤320℃). Anhydrite remained stable during rapid cooling of the sample chamber, showing that the gypsum-anhydrite transition involving both dissolution and precipitation processes is

  2. Low Power and High Sensitivity MOSFET-Based Pressure Sensor

    International Nuclear Information System (INIS)

    Zhang Zhao-Hua; Ren Tian-Ling; Zhang Yan-Hong; Han Rui-Rui; Liu Li-Tian

    2012-01-01

    Based on the metal-oxide-semiconductor field effect transistor (MOSFET) stress sensitive phenomenon, a low power MOSFET pressure sensor is proposed. Compared with the traditional piezoresistive pressure sensor, the present pressure sensor displays high performances on sensitivity and power consumption. The sensitivity of the MOSFET sensor is raised by 87%, meanwhile the power consumption is decreased by 20%. (cross-disciplinary physics and related areas of science and technology)

  3. Decaf: Decoupled Dataflows for In Situ High-Performance Workflows

    Energy Technology Data Exchange (ETDEWEB)

    Dreher, M.; Peterka, T.

    2017-07-31

    Decaf is a dataflow system for the parallel communication of coupled tasks in an HPC workflow. The dataflow can perform arbitrary data transformations ranging from simply forwarding data to complex data redistribution. Decaf does this by allowing the user to allocate resources and execute custom code in the dataflow. All communication through the dataflow is efficient parallel message passing over MPI. The runtime for calling tasks is entirely message-driven; Decaf executes a task when all messages for the task have been received. Such a messagedriven runtime allows cyclic task dependencies in the workflow graph, for example, to enact computational steering based on the result of downstream tasks. Decaf includes a simple Python API for describing the workflow graph. This allows Decaf to stand alone as a complete workflow system, but Decaf can also be used as the dataflow layer by one or more other workflow systems to form a heterogeneous task-based computing environment. In one experiment, we couple a molecular dynamics code with a visualization tool using the FlowVR and Damaris workflow systems and Decaf for the dataflow. In another experiment, we test the coupling of a cosmology code with Voronoi tessellation and density estimation codes using MPI for the simulation, the DIY programming model for the two analysis codes, and Decaf for the dataflow. Such workflows consisting of heterogeneous software infrastructures exist because components are developed separately with different programming models and runtimes, and this is the first time that such heterogeneous coupling of diverse components was demonstrated in situ on HPC systems.

  4. Application of a Novel and Automated Branched DNA in Situ Hybridization Method for the Rapid and Sensitive Localization of mRNA Molecules in Plant Tissues

    Directory of Open Access Journals (Sweden)

    Andrew J. Bowling

    2014-04-01

    Full Text Available Premise of the study: A novel branched DNA detection technology, RNAscope in situ hybridization (ISH, originally developed for use on human clinical and animal tissues, was adapted for use in plant tissue in an attempt to overcome some of the limitations associated with traditional ISH assays. Methods and Results: Zea mays leaf tissue was formaldehyde fixed and paraffin embedded (FFPE and then probed with the RNAscope ISH assay for two endogenous genes, phosphoenolpyruvate carboxylase (PEPC and phosphoenolpyruvate carboxykinase (PEPCK. Results from both manual and automated methods showed tissue- and cell-specific mRNA localization patterns expected from these well-studied genes. Conclusions: RNAscope ISH is a sensitive method that generates high-quality, easily interpretable results from FFPE plant tissues. Automation of the RNAscope method on the Ventana Discovery Ultra platform allows significant advantages for repeatability, reduction in variability, and flexibility of workflow processes.

  5. In Situ Observation of Gypsum-Anhydrite Transition at High Pressure and High Temperature

    International Nuclear Information System (INIS)

    Liu Chuan-Jiang; Zheng Hai-Fei

    2012-01-01

    An in-situ Raman spectroscopic study of gypsum-anhydrite transition under a saturated water condition at high pressure and high temperature is performed using a hydrothermal diamond anvil cell (HDAC). The experimental results show that gypsum dissolvs in water at ambient temperature and above 496 MPa. With increasing temperature, the anhydrite (CaSO 4 ) phase precipitates at 250–320°C in the pressure range of 1.0–1.5GPa, indicating that under a saturated water condition, both stable conditions of pressure and temperature and high levels of Ca and SO 4 ion concentrations in aqueous solution are essential for the formation of anhydrite. A linear relationship between the pressure and temperature for the precipitation of anhydrite is established as P(GPa) = 0.0068T−0.7126 (250°C≤T≤320°C). Anhydrite remained stable during rapid cooling of the sample chamber, showing that the gypsum-anhydrite transition involving both dissolution and precipitation processes is irreversible at high pressure and high temperature. (geophysics, astronomy, and astrophysics)

  6. Gulf-Wide Information System, Environmental Sensitivity Index In-Situ Burning Database, Geographic NAD83, LDWF (2001) [esi_in_situ_LDWF_2001

    Data.gov (United States)

    Louisiana Geographic Information Center — This data set contains boundaries for in-situ burning preapproval and exclusion areas in coastal Louisiana. Feature-specific contact, type, and source information...

  7. Novel charge sensitive preamplifier without high-value feedback resistor

    International Nuclear Information System (INIS)

    Xi Deming

    1992-01-01

    A novel charge sensitive preamplifier is introduced. The method of removing the high value feedback resistor, the circuit design and analysis are described. A practical circuit and its measured performances are provided

  8. Comparison of Fluorescence In Situ Hybridization and Chromogenic In Situ Hybridization for Low and High Throughput HER2 Genetic Testing

    DEFF Research Database (Denmark)

    Poulsen, Tim S; Espersen, Maiken Lise Marcker; Kofoed, Vibeke

    2013-01-01

    cancer patients with HER2 immunohistochemistry (IHC) results scored as 0/1+, 2+, and 3+. HER2 genetic status was analysed using chromogenic in situ hybridization (CISH) and fluorescence in situ hybridization (FISH). Scoring results were documented through digital image analysis. The cancer region...

  9. Experimental Investigation and High Resolution Simulation of In-Situ Combustion Processes

    Energy Technology Data Exchange (ETDEWEB)

    Margot Gerritsen; Tony Kovscek

    2008-04-30

    This final technical report describes work performed for the project 'Experimental Investigation and High Resolution Numerical Simulator of In-Situ Combustion Processes', DE-FC26-03NT15405. In summary, this work improved our understanding of in-situ combustion (ISC) process physics and oil recovery. This understanding was translated into improved conceptual models and a suite of software algorithms that extended predictive capabilities. We pursued experimental, theoretical, and numerical tasks during the performance period. The specific project objectives were (i) identification, experimentally, of chemical additives/injectants that improve combustion performance and delineation of the physics of improved performance, (ii) establishment of a benchmark one-dimensional, experimental data set for verification of in-situ combustion dynamics computed by simulators, (iii) develop improved numerical methods that can be used to describe in-situ combustion more accurately, and (iv) to lay the underpinnings of a highly efficient, 3D, in-situ combustion simulator using adaptive mesh refinement techniques and parallelization. We believe that project goals were met and exceeded as discussed.

  10. A high-sensitivity neutron counter and waste-drum counting with the high-sensitivity neutron instrument

    International Nuclear Information System (INIS)

    Hankins, D.E.; Thorngate, J.H.

    1993-04-01

    At Lawrence Livermore National Laboratory (LLNL), a highly sensitive neutron counter was developed that can detect and accurately measure the neutrons from small quantities of plutonium or from other low-level neutron sources. This neutron counter was originally designed to survey waste containers leaving the Plutonium Facility. However, it has proven to be useful in other research applications requiring a high-sensitivity neutron instrument

  11. A novel fabrication technology of in situ TiB2/6063Al composites: High energy ball milling and melt in situ reaction

    International Nuclear Information System (INIS)

    Zhang, S.-L.; Yang, J.; Zhang, B.-R.; Zhao, Y.-T.; Chen, G.; Shi, X.-X.; Liang, Z.-P.

    2015-01-01

    Highlights: • This paper presents a novel technology to fabricate the TiB 2 /6063Al composites. • The novel technology decreases in situ reaction temperature and shortens the time. • The reaction mechanism of in situ reaction at the low temperature is discussed. • Effect of ball milling time and in situ reaction time on the composites is studied. - Abstract: TiB 2 /6063Al matrix composites are fabricated from Al–TiO 2 –B 2 O 3 system by the technology combining high energy ball milling with melt in situ reaction. The microstructure and tensile properties of the composites are investigated by XRD, SEM, EDS, TEM and electronic tensile testing. The results indicate that high energy ball milling technology decreases the in situ reaction temperature and shortens the reaction time for Al–TiO 2 –B 2 O 3 system in contrast with the conventional melt in situ synthesis. The morphology of in situ TiB 2 particles is exhibited in irregular shape or nearly circular shape, and the average size of the particles is less than 700 nm, thereinto the minimum size is approximately 200 nm. In addition, the morphology and size of the reinforced particles are affected by the time of ball milling and in situ reaction. TEM images indicate that the interface between 6063Al matrix and TiB 2 particles is clear and no interfacial outgrowth is observed. Tensile testing results show that the as-cast TiB 2 /6063Al composites exhibit a much higher strength, reaching 191 MPa, which is 1.23 times as high as the as-cast 6063Al matrix. Besides, the tensile fracture surface of the composites displays the dimple-fracture character

  12. A novel fabrication technology of in situ TiB{sub 2}/6063Al composites: High energy ball milling and melt in situ reaction

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, S.-L.; Yang, J. [School of Materials Science and Engineering, Jiangsu University, Zhenjiang, Jiangsu 212013 (China); Zhang, B.-R. [School of Mechanical Engineering, Qilu University of Technology, Jinan, Shandong 250022 (China); Zhao, Y.-T., E-mail: 278075525@qq.com [School of Materials Science and Engineering, Jiangsu University, Zhenjiang, Jiangsu 212013 (China); Chen, G.; Shi, X.-X.; Liang, Z.-P. [School of Materials Science and Engineering, Jiangsu University, Zhenjiang, Jiangsu 212013 (China)

    2015-08-05

    Highlights: • This paper presents a novel technology to fabricate the TiB{sub 2}/6063Al composites. • The novel technology decreases in situ reaction temperature and shortens the time. • The reaction mechanism of in situ reaction at the low temperature is discussed. • Effect of ball milling time and in situ reaction time on the composites is studied. - Abstract: TiB{sub 2}/6063Al matrix composites are fabricated from Al–TiO{sub 2}–B{sub 2}O{sub 3} system by the technology combining high energy ball milling with melt in situ reaction. The microstructure and tensile properties of the composites are investigated by XRD, SEM, EDS, TEM and electronic tensile testing. The results indicate that high energy ball milling technology decreases the in situ reaction temperature and shortens the reaction time for Al–TiO{sub 2}–B{sub 2}O{sub 3} system in contrast with the conventional melt in situ synthesis. The morphology of in situ TiB{sub 2} particles is exhibited in irregular shape or nearly circular shape, and the average size of the particles is less than 700 nm, thereinto the minimum size is approximately 200 nm. In addition, the morphology and size of the reinforced particles are affected by the time of ball milling and in situ reaction. TEM images indicate that the interface between 6063Al matrix and TiB{sub 2} particles is clear and no interfacial outgrowth is observed. Tensile testing results show that the as-cast TiB{sub 2}/6063Al composites exhibit a much higher strength, reaching 191 MPa, which is 1.23 times as high as the as-cast 6063Al matrix. Besides, the tensile fracture surface of the composites displays the dimple-fracture character.

  13. Fluorescence photooxidation with eosin: a method for high resolution immunolocalization and in situ hybridization detection for light and electron microscopy

    Science.gov (United States)

    1994-01-01

    A simple method is described for high-resolution light and electron microscopic immunolocalization of proteins in cells and tissues by immunofluorescence and subsequent photooxidation of diaminobenzidine tetrahydrochloride into an insoluble osmiophilic polymer. By using eosin as the fluorescent marker, a substantial improvement in sensitivity is achieved in the photooxidation process over other conventional fluorescent compounds. The technique allows for precise correlative immunolocalization studies on the same sample using fluorescence, transmitted light and electron microscopy. Furthermore, because eosin is smaller in size than other conventional markers, this method results in improved penetration of labeling reagents compared to gold or enzyme based procedures. The improved penetration allows for three-dimensional immunolocalization using high voltage electron microscopy. Fluorescence photooxidation can also be used for high resolution light and electron microscopic localization of specific nucleic acid sequences by in situ hybridization utilizing biotinylated probes followed by an eosin-streptavidin conjugate. PMID:7519623

  14. Experimental in situ investigations of turbulence under high pressure.

    Science.gov (United States)

    Song, Kwonyul; Al-Salaymeh, Ahmed; Jovanovic, Jovan; Rauh, Cornelia; Delgado, Antonio

    2010-02-01

    In tube injection systems applied in high-pressure processing of packed biomaterials and foods, the pressure-transmitting medium is injected into the vessel to increase the pressure up to 1000 MPa, generating a submerged liquid-free jet. The presence of a turbulent-free jet during the pressurization phase and its positive influence on the homogeneity of the product treatment has already been examined by computational fluid dynamics investigations. However, no experimental data have supported the existence and properties of turbulent flow under high-pressure (HP) conditions up to 400 MPa. This contribution presents the development of two experimental setups: HP-laser Doppler anemometry and HP-hot wire anemometry. For the first time the time-averaged velocity profiles of a free jet during pressurization up to 300 MPa at different Reynolds numbers (Re) have been obtained. In this article, the dependence of the velocity profiles on the Re is discussed in detail. Moreover, the relaminarization phenomenon of the turbulent pipe flow most likely caused by the compressibility effects and viscosity changes of the pressure-transmitting medium is examined.

  15. Sensitivity of Helicobacter pylori detection by Giemsa staining is poor in comparison with immunohistochemistry and fluorescent in situ hybridization and strongly depends on inflammatory activity.

    Science.gov (United States)

    Kocsmár, Éva; Szirtes, Ildikó; Kramer, Zsófia; Szijártó, Attila; Bene, László; Buzás, György Miklós; Kenessey, István; Bronsert, Peter; Csanadi, Agnes; Lutz, Lisa; Werner, Martin; Wellner, Ulrich Friedrich; Kiss, András; Schaff, Zsuzsa; Lotz, Gábor

    2017-08-01

    Conventional stainings (including H&E and special stains like Giemsa) are the most widely applied histopathologic detection methods of Helicobacter pylori (HP). We aimed to compare the diagnostic performance of Giemsa staining with immunohistochemistry (IHC) and fluorescent in situ hybridization (FISH) on a monocentric cohort of 2896 gastric biopsies and relate results to histologic alterations in order to find such histopathologic subgroups in which these methods underperform. All cases were categorized regarding presence or absence of chronic gastritis, inflammatory activity, and mucosal structural alterations. Giemsa revealed 687 cases (23.7%), IHC 795 cases (27.5%), and FISH 788 cases (27.2%) as being HP positive. Giemsa showed significantly lower overall sensitivity (83.3%) compared to IHC (98.8%) and FISH (98.0%). Moreover, the sensitivity of Giemsa dramatically dropped to 33.6% in the nonactive cases. We found that sensitivity of Giemsa strongly depends on HP density and, accordingly, on the presence of activity. Structural alterations (intestinal metaplasia, atrophy, etc.) had only no or weak effect on sensitivity of the three stainings. Both IHC and FISH proved to be equally reliable HP detecting techniques whose diagnostic performance is minimally influenced by mucosal inflammatory and structural alterations contrary to conventional stainings. We highly recommend immunohistochemistry for clinically susceptible, nonactive chronic gastritis cases, if the conventional stain-based HP detection is negative. Moreover, we recommend to use IHC more widely as basic HP stain. Helicobacter pylori FISH technique is primarily recommended to determine bacterial clarithromycin resistance. Furthermore, it is another accurate diagnostic tool for HP. © 2017 John Wiley & Sons Ltd.

  16. Initial characterization of a highly contaminated high explosives outfall in preparation for in situ bioremediation

    Energy Technology Data Exchange (ETDEWEB)

    Betty A. Strietelmeier; Patrick J. Coyne; Patricia A. Leonard; W. Lamar Miller; Jerry R. Brian

    1999-12-01

    In situ bioremediation is a viable, cost-effective treatment for environmental contamination of many kinds. The feasibility of using biological techniques to remediate soils contaminated with high explosives (HE) requires laboratory evaluation before proceeding to a larger scale field operation. Laboratory investigations have been conducted at pilot scale which indicate that an anaerobic process could be successful at reducing levels of HE, primarily HMX, RDX and TNT, in contaminated soils. A field demonstration project has been designed to create an anaerobic environment for the degradation of HE materials. The first step in this project, initial characterization of the test area, was conducted and is the subject of this report. The levels of HE compounds found in the samples from the test area were higher than the EPA Method 8330 was able to extract without subsequent re-precipitation; therefore, a new method was developed using a superior extractant system. The test area sampling design was relatively simple as one might expect in an initial characterization. A total of 60 samples were each removed to a depth of 4 inches using a 1 inch diameter corer. The samples were spaced at relatively even intervals across a 20 foot cross-section through the middle of four 7-foot-long adjacent plots which are designed to be a part of an in situ bioremediation experiment. Duplicate cores were taken from each location for HE extraction and analysis in order to demonstrate and measure the heterogeneity of the contamination. Each soil sample was air dried and ball-milled to provide a homogeneous solid for extraction and analysis. Several samples had large consolidated pieces of what appeared to be solid HE. These were not ball-milled due to safety concerns, but were dissolved and the solutions were analyzed. The new extraction method was superior in that results obtained for several of the contaminants were up to 20 times those obtained with the EPA extraction method. The

  17. In situ study starch gelatinization under ultra-high hydrostatic pressure using synchrotron SAXS

    KAUST Repository

    Yang, Zhi; Gu, Qinfen; Lam, Elisa; Tian, Feng; Chaieb, Saharoui; Hemar, Yacine

    2015-01-01

    The gelatinization of waxy (very low amylose) corn and potato starches by high hydrostatic pressure (HHP) (up to ∼1 GPa) was investigated in situ using synchrotron small-angle X-ray scattering (SAXS) on samples held in a diamond anvil cell (DAC

  18. Quantification of in situ temperature measurements on a PBI-based high temperature PEMFC unit cell

    DEFF Research Database (Denmark)

    Lebæk, Jesper; Ali, Syed Talat; Møller, Per

    2010-01-01

    The temperature is a very important operating parameter for all types of fuel cells. In the present work distributed in situ temperature measurements are presented on a polybenzimidazole based high temperature PEM fuel cell (HT-PEM). A total of 16 T-type thermocouples were embedded on both the an...

  19. Achieving sensitive, high-resolution laser spectroscopy at CRIS

    Energy Technology Data Exchange (ETDEWEB)

    Groote, R. P. de [Instituut voor Kern- en Stralingsfysica, KU Leuven (Belgium); Lynch, K. M., E-mail: kara.marie.lynch@cern.ch [EP Department, CERN, ISOLDE (Switzerland); Wilkins, S. G. [The University of Manchester, School of Physics and Astronomy (United Kingdom); Collaboration: the CRIS collaboration

    2017-11-15

    The Collinear Resonance Ionization Spectroscopy (CRIS) experiment, located at the ISOLDE facility, has recently performed high-resolution laser spectroscopy, with linewidths down to 20 MHz. In this article, we present the modifications to the beam line and the newly-installed laser systems that have made sensitive, high-resolution measurements possible. Highlights of recent experimental campaigns are presented.

  20. In situ spectroscopy and spectroelectrochemistry of uranium in high-temperature alkali chloride molten salts.

    Science.gov (United States)

    Polovov, Ilya B; Volkovich, Vladimir A; Charnock, John M; Kralj, Brett; Lewin, Robert G; Kinoshita, Hajime; May, Iain; Sharrad, Clint A

    2008-09-01

    Soluble uranium chloride species, in the oxidation states of III+, IV+, V+, and VI+, have been chemically generated in high-temperature alkali chloride melts. These reactions were monitored by in situ electronic absorption spectroscopy. In situ X-ray absorption spectroscopy of uranium(VI) in a molten LiCl-KCl eutectic was used to determine the immediate coordination environment about the uranium. The dominant species in the melt was [UO 2Cl 4] (2-). Further analysis of the extended X-ray absorption fine structure data and Raman spectroscopy of the melts quenched back to room temperature indicated the possibility of ordering beyond the first coordination sphere of [UO 2Cl 4] (2-). The electrolytic generation of uranium(III) in a molten LiCl-KCl eutectic was also investigated. Anodic dissolution of uranium metal was found to be more efficient at producing uranium(III) in high-temperature melts than the cathodic reduction of uranium(IV). These high-temperature electrolytic processes were studied by in situ electronic absorption spectroelectrochemistry, and we have also developed in situ X-ray absorption spectroelectrochemistry techniques to probe both the uranium oxidation state and the uranium coordination environment in these melts.

  1. Large palpable ductal carcinoma in situ is Her-2 positive with high nuclear grade.

    Science.gov (United States)

    Monabati, Ahmad; Sokouti, Ali-Reza; Noori, Sadat Noori; Safaei, Akbar; Talei, Abd-Rasul; Omidvari, Shapoor; Azarpira, Negar

    2015-01-01

    Ductal carcinoma in situ (DCIS) of the breast is a heterogeneous group with variable clinical presentation. The exact molecular mechanism is not known why some ductal carcinomas may reach to such a large size but still remains in situ. Although, molecular classification of DCIS lesions and nuclear grading are important for identification of more aggressive lesions but it is not sufficient. Our aim was to examine the expression pattern of immunohistochemical (IHC) markers of ER, PR, HER-2 in palpable DCIS lesions and compare with clinicopathological findings. Our center is referral hospital from South of Iran. Samples were obtained from fifty four patients with a diagnosis of palpable DCIS. Equivocal (2+) case in HER-2 IHC testing was more characterized by chromogenic in situ hybridization. The positive frequency of HER2, ER, and PR was 92%, 48%, and 37% respectively. Palpable DCIS lesions were significantly more HER-2 positive (92%). The DCIS cases were more likely to be of high nuclear grade (grade III) and Her-2 positive cases were more likely to be of high nuclear grade than intermediate grade. All ER negative tumors had high nuclear grade. The Her-2 positivity is suggested as the most important factor responsible for marked in situ proliferation and production of palpable mass.

  2. Retinal sensitivity and choroidal thickness in high myopia.

    Science.gov (United States)

    Zaben, Ahmad; Zapata, Miguel Á; Garcia-Arumi, Jose

    2015-03-01

    To estimate the association between choroidal thickness in the macular area and retinal sensitivity in eyes with high myopia. This investigation was a transversal study of patients with high myopia, all of whom had their retinal sensitivity measured with macular integrity assessment microperimetry. The choroidal thicknesses in the macular area were then measured by optical coherence tomography, and statistical correlations between their functionality and the anatomical structuralism, as assessed by both types of measurements, were analyzed. Ninety-six eyes from 77 patients with high myopia were studied. The patients had a mean age ± standard deviation of 38.9 ± 13.2 years, with spherical equivalent values ranging from -6.00 diopter to -20.00 diopter (8.74 ± 2.73 diopter). The mean central choroidal thickness was 159.00 ± 50.57. The mean choroidal thickness was directly correlated with sensitivity (r = 0.306; P = 0.004) and visual acuity but indirectly correlated with the spherical equivalent values and patient age. The mean sensitivity was not significantly correlated with the macular foveal thickness (r = -0.174; P = 0.101) or with the overall macular thickness (r = 0.103; P = 0.334); furthermore, the mean sensitivity was significantly correlated with visual acuity (r = 0.431; P < 0.001) and the spherical equivalent values (r = -0.306; P = 0.003). Retinal sensitivity in highly myopic eyes is directly correlated with choroidal thickness and does not seem to be associated with retinal thickness. Thus, in patients with high myopia, accurate measurements of choroidal thickness may provide more accurate information about this pathologic condition because choroidal thickness correlates to a greater degree with the functional parameters, patient age, and spherical equivalent values.

  3. A sensitive and selective electrochemical biosensor for the determination of beta-amyloid oligomer by inhibiting the peptide-triggered in situ assembly of silver nanoparticles

    Directory of Open Access Journals (Sweden)

    Xing Y

    2017-04-01

    Full Text Available Yun Xing,1,2 Xiao-Zhen Feng,2 Lipeng Zhang,1 Jiating Hou,2 Guo-Cheng Han,2 Zhencheng Chen2 1Henan Province of Key Laboratory of New Optoelectronic Functional Materials, College of Chemistry and Chemical Engineering, Anyang Normal University, Anyang, 2School of Life and Environmental Sciences, Guilin University of Electronic Technology, Guilin, Guangxi, People’s Republic of China Abstract: Soluble beta-amyloid (Aβ oligomer is believed to be the most important toxic species in the brain of Alzheimer’s disease (AD patients. Thus, it is critical to develop a simple method for the selective detection of Aβ oligomer with low cost and high sensitivity. In this paper, we report an electrochemical method for the detection of Aβ oligomer with a peptide as the bioreceptor and silver nanoparticle (AgNP aggregates as the redox reporters. This strategy is based on the conversion of AgNP-based colorimetric assay into electrochemical analysis. Specifically, the peptide immobilized on the electrode surface and presented in solution triggered together the in situ formation of AgNP aggregates, which produced a well-defined electrochemical signal. However, the specific binding of Aβ oligomer to the immobilized peptide prevented the in situ assembly of AgNPs. As a result, a poor electrochemical signal was observed. The detection limit of the method was found to be 6 pM. Furthermore, the amenability of this method for the analysis of Aβ oligomer in serum and artificial cerebrospinal fluid (aCSF samples was demonstrated. Keywords: electrochemical biosensors, Alzheimer’s disease, beta-amyloid oligomer, peptide, silver nanoparticles

  4. BH3105 type neutron dose equivalent meter of high sensitivity

    International Nuclear Information System (INIS)

    Ji Changsong; Zhang Enshan; Yang Jianfeng; Zhang Hong; Huang Jiling

    1995-10-01

    It is noted that to design a neutron dose meter of high sensitivity is almost impossible in the frame of traditional designing principle--'absorption net principle'. Based on a newly proposed principle of obtaining neutron dose equi-biological effect adjustment--' absorption stick principle', a brand-new neutron dose-equivalent meter with high neutron sensitivity BH3105 has been developed. Its sensitivity reaches 10 cps/(μSv·h -1 ), which is 18∼40 times higher than one of foreign products of the same kind and is 10 4 times higher than that of domestic FJ342 neutron rem-meter. BH3105 has a measurement range from 0.1μSv/h to 1 Sv/h which is 1 or 2 orders wider than that of the other's. It has the advanced properties of gamma-resistance, energy response, orientation, etc. (6 tabs., 5 figs.)

  5. A high sensitivity nanomaterial based SAW humidity sensor

    Energy Technology Data Exchange (ETDEWEB)

    Wu, T-T; Chou, T-H [Institute of Applied Mechanics, National Taiwan University, Taipei 106, Taiwan (China); Chen, Y-Y [Department of Mechanical Engineering, Tatung University, Taipei 104, Taiwan (China)], E-mail: wutt@ndt.iam.ntu.edu.tw

    2008-04-21

    In this paper, a highly sensitive humidity sensor is reported. The humidity sensor is configured by a 128{sup 0}YX-LiNbO{sub 3} based surface acoustic wave (SAW) resonator whose operating frequency is at 145 MHz. A dual delay line configuration is realized to eliminate external temperature fluctuations. Moreover, for nanostructured materials possessing high surface-to-volume ratio, large penetration depth and fast charge diffusion rate, camphor sulfonic acid doped polyaniline (PANI) nanofibres are synthesized by the interfacial polymerization method and further deposited on the SAW resonator as selective coating to enhance sensitivity. The humidity sensor is used to measure various relative humidities in the range 5-90% at room temperature. Results show that the PANI nanofibre based SAW humidity sensor exhibits excellent sensitivity and short-term repeatability.

  6. Performance of terahertz metamaterials as high-sensitivity sensor

    Science.gov (United States)

    He, Yanan; Zhang, Bo; Shen, Jingling

    2017-09-01

    A high-sensitivity sensor based on the resonant transmission characteristics of terahertz (THz) metamaterials was investigated, with the proposal and fabrication of rectangular bar arrays of THz metamaterials exhibiting a period of 180 μm on a 25 μm thick flexible polyimide. Varying the size of the metamaterial structure revealed that the length of the rectangular unit modulated the resonant frequency, which was verified by both experiment and simulation. The sensing characteristics upon varying the surrounding media in the sample were tested by simulation and experiment. Changing the surrounding medium from that of air to that of alcohol or oil produced resonant frequency redshifts of 80 GHz or 150 GHz, respectively, which indicates that the sensor possessed a high sensitivity of 667 GHz per unit of refractive index. Finally, the influence of the sample substrate thickness on the sensor sensitivity was investigated by simulation. It may be a reference for future sensor design.

  7. pH-Sensitive polymer assisted self-aggregation of bis(pyrene) in living cells in situ with turn-on fluorescence

    International Nuclear Information System (INIS)

    Duan, Zhongyu; Gao, Yu-Juan; Wang, Yongmei; Hou, Chunyuan; Qiao, Zeng-Ying; Qiao, Shenglin; Wang, Lei; Wang, Hao

    2015-01-01

    Supramolecular self-assemblies with various nanostructures in organic and aqueous solutions have been prepared with desired functions. However, in situ construction of self-assembled superstructures in physiological conditions to achieve expected biological functions remains a challenge. Here, we report a supramolecular system to realize the in situ formation of nanoaggregates in living cells. The bis(pyrene) monomers were dispersed inside of hydrophobic domains of pH-sensitive polymeric micelles and delivered to the lysosomes of cells. In the acidic lysosomes, the bis(pyrene) monomers were released and self-aggregated with turn-on fluorescence. We envision this strategy for in situ construction of supramolecular nanostructures in living cells will pave the way for molecular diagnostics in the future. (paper)

  8. Low Cost Al-Si Casting Alloy As In-Situ Composite for High Temperature Applications

    Science.gov (United States)

    Lee, Jonathan A.

    2000-01-01

    A new aluminum-silicon (Al-Si) alloy has been successfully developed at NASA- Marshall Space Flight Center (MSFC) that has significant improvement in tensile and fatigue strength at elevated temperatures (500 F-700 F). The alloy offers a number of benefits such as light weight, high hardness, low thermal expansion and high surface wear resistance. In hypereutectic form, this alloy is considered as an in-situ Al-Si composite with tensile strength of about 90% higher than the auto industry 390 alloy at 600 F. This composite is very economically produced by using either conventional permanent steel molds or die casting. The projected material cost is less than $0.90 per pound, and automotive components such as pistons can be cast for high production rate using conventional casting techniques with a low and fully accounted cost. Key Words: Metal matrix composites, In-situ composite, aluminum-silicon alloy, hypereutectic alloy, permanent mold casting, die casting.

  9. Sensitive high performance liquid chromatographic method for the ...

    African Journals Online (AJOL)

    A new simple, sensitive, cost-effective and reproducible high performance liquid chromatographic (HPLC) method for the determination of proguanil (PG) and its metabolites, cycloguanil (CG) and 4-chlorophenylbiguanide (4-CPB) in urine and plasma is described. The extraction procedure is a simple three-step process ...

  10. Methylation-Sensitive High Resolution Melting (MS-HRM).

    Science.gov (United States)

    Hussmann, Dianna; Hansen, Lise Lotte

    2018-01-01

    Methylation-Sensitive High Resolution Melting (MS-HRM) is an in-tube, PCR-based method to detect methylation levels at specific loci of interest. A unique primer design facilitates a high sensitivity of the assays enabling detection of down to 0.1-1% methylated alleles in an unmethylated background.Primers for MS-HRM assays are designed to be complementary to the methylated allele, and a specific annealing temperature enables these primers to anneal both to the methylated and the unmethylated alleles thereby increasing the sensitivity of the assays. Bisulfite treatment of the DNA prior to performing MS-HRM ensures a different base composition between methylated and unmethylated DNA, which is used to separate the resulting amplicons by high resolution melting.The high sensitivity of MS-HRM has proven useful for detecting cancer biomarkers in a noninvasive manner in urine from bladder cancer patients, in stool from colorectal cancer patients, and in buccal mucosa from breast cancer patients. MS-HRM is a fast method to diagnose imprinted diseases and to clinically validate results from whole-epigenome studies. The ability to detect few copies of methylated DNA makes MS-HRM a key player in the quest for establishing links between environmental exposure, epigenetic changes, and disease.

  11. Aluminum nano-cantilevers for high sensitivity mass sensors

    DEFF Research Database (Denmark)

    Davis, Zachary James; Boisen, Anja

    2005-01-01

    We have fabricated Al nano-cantilevers using a very simple one mask contact UV lithography technique with lateral dimensions under 500 nm and vertical dimensions of approximately 100 nm. These devices are demonstrated as highly sensitive mass sensors by measuring their dynamic properties. Further...

  12. High sensitivity probe absorption technique for time-of-flight ...

    Indian Academy of Sciences (India)

    Abstract. We report on a phase-sensitive probe absorption technique with high sen- sitivity, capable of detecting a few hundred ultra-cold atoms in flight in an observation time of a few milliseconds. The large signal-to-noise ratio achieved is sufficient for reliable measurements on low intensity beams of cold atoms.

  13. A Novel Polymer Electrolyte Using In-situ Quanternization for All Solid-state Dye-sensitized Solar Cell

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    1 Introduction Dye-sensitized solar cells (DSSCs) with a mesoporous network of interconnected TiO2 nanocrystals have attracted wide-spread scientific and technological interest over the past decades due to its low cost and high energy conversion efficiency. Meantime, it also has been considered as potential alternative to conventional photovoltaic devices. In 2001, Gratzel group constructed such kind of DSSC with the conversion efficiency of more than 11%[1]. But this system uses liquid electrolyte with...

  14. One year follow-up of contrast sensitivity following conventional laser in situ keratomileusis and laser epithelial keratomileusis.

    Science.gov (United States)

    Townley, Deirdre; Kirwan, Caitriona; O'Keefe, Michael

    2012-02-01

    To determine the effect of conventional laser in situ keratomileusis (LASIK) and laser epithelial keratomileusis (LASEK) for myopia on contrast sensitivity (CS) using the Pelli-Robson and Vector Vision CSV-1000E CS tests. A prospective, comparative study was conducted on 36 eyes of 36 patients with myopia undergoing LASIK (18 eyes) and LASEK (18 eyes). Surgery was performed using the Technolas 217z laser (Bausch & Lomb). CS was recorded preoperatively and at 3, 6 and 12 months postoperatively. No statistically significant difference was found in LogMAR uncorrected visual acuity post-LASIK (-0.02 ± 0.16) and LASEK (-0.04 ± 0.14). Using the Pelli-Robson, CS was significantly lower in the LASIK group 3 and 6 months postoperatively. No significant postoperative reduction in CS was observed in either treatment group. Using the CSV-1000E test, CS was significantly reduced post-LASIK at 3 (p = 0.05) and 6 (p = 0.05) cycles/degree under photopic conditions. No significant postoperative change occurred in the LASEK group under photopic or scotopic conditions. There was no significant difference in postoperative CS between the LASIK and LASEK groups at 3, 6, 12 or 18 cycles/degree using the CSV-1000E test. One year postoperatively, there was no difference in CS between both treatment groups using the Pelli-Robson and CSV-1000E tests. CS was reduced postoperatively in the LASIK group at the lower spatial frequencies under photopic conditions. No postoperative change was detected in CS following LASIK or LASEK using the Pelli-Robson test. © 2010 The Authors. Journal compilation © 2010 Acta Ophthalmol.

  15. Highly sensitive detection using microring resonator and nanopores

    Science.gov (United States)

    Bougot-Robin, K.; Hoste, J. W.; Le Thomas, N.; Bienstman, P.; Edel, J. B.

    2016-04-01

    One of the most significant challenges facing physical and biological scientists is the accurate detection and identification of single molecules in free-solution environments. The ability to perform such sensitive and selective measurements opens new avenues for a large number of applications in biological, medical and chemical analysis, where small sample volumes and low analyte concentrations are the norm. Access to information at the single or few molecules scale is rendered possible by a fine combination of recent advances in technologies. We propose a novel detection method that combines highly sensitive label-free resonant sensing obtained with high-Q microcavities and position control in nanoscale pores (nanopores). In addition to be label-free and highly sensitive, our technique is immobilization free and does not rely on surface biochemistry to bind probes on a chip. This is a significant advantage, both in term of biology uncertainties and fewer biological preparation steps. Through combination of high-Q photonic structures with translocation through nanopore at the end of a pipette, or through a solid-state membrane, we believe significant advances can be achieved in the field of biosensing. Silicon microrings are highly advantageous in term of sensitivity, multiplexing, and microfabrication and are chosen for this study. In term of nanopores, we both consider nanopore at the end of a nanopipette, with the pore being approach from the pipette with nanoprecise mechanical control. Alternatively, solid state nanopores can be fabricated through a membrane, supporting the ring. Both configuration are discussed in this paper, in term of implementation and sensitivity.

  16. A highly sensitive underwater video system for use in turbid aquaculture ponds.

    Science.gov (United States)

    Hung, Chin-Chang; Tsao, Shih-Chieh; Huang, Kuo-Hao; Jang, Jia-Pu; Chang, Hsu-Kuang; Dobbs, Fred C

    2016-08-24

    The turbid, low-light waters characteristic of aquaculture ponds have made it difficult or impossible for previous video cameras to provide clear imagery of the ponds' benthic habitat. We developed a highly sensitive, underwater video system (UVS) for this particular application and tested it in shrimp ponds having turbidities typical of those in southern Taiwan. The system's high-quality video stream and images, together with its camera capacity (up to nine cameras), permit in situ observations of shrimp feeding behavior, shrimp size and internal anatomy, and organic matter residues on pond sediments. The UVS can operate continuously and be focused remotely, a convenience to shrimp farmers. The observations possible with the UVS provide aquaculturists with information critical to provision of feed with minimal waste; determining whether the accumulation of organic-matter residues dictates exchange of pond water; and management decisions concerning shrimp health.

  17. NK sensitivity of neuroblastoma cells determined by a highly sensitive coupled luminescent method

    International Nuclear Information System (INIS)

    Ogbomo, Henry; Hahn, Anke; Geiler, Janina; Michaelis, Martin; Doerr, Hans Wilhelm; Cinatl, Jindrich

    2006-01-01

    The measurement of natural killer (NK) cells toxicity against tumor or virus-infected cells especially in cases with small blood samples requires highly sensitive methods. Here, a coupled luminescent method (CLM) based on glyceraldehyde-3-phosphate dehydrogenase release from injured target cells was used to evaluate the cytotoxicity of interleukin-2 activated NK cells against neuroblastoma cell lines. In contrast to most other methods, CLM does not require the pretreatment of target cells with labeling substances which could be toxic or radioactive. The effective killing of tumor cells was achieved by low effector/target ratios ranging from 0.5:1 to 4:1. CLM provides highly sensitive, safe, and fast procedure for measurement of NK cell activity with small blood samples such as those obtained from pediatric patients

  18. Instruction manual for ORNL tandem high abundance sensitivity mass spectrometer

    International Nuclear Information System (INIS)

    Smith, D.H.; McKown, H.S.; Chrisite, W.H.; Walker, R.L.; Carter, J.A.

    1976-06-01

    This manual describes the physical characteristics of the tandem mass spectrometer built by Oak Ridge National Laboratory for the International Atomic Energy Agency. Specific requirements met include ability to run small samples, high abundance sensitivity, good precision and accuracy, and adequate sample throughput. The instrument is capable of running uranium samples as small as 10 -12 g and has an abundance sensitivity in excess of 10 6 . Precision and accuracy are enhanced by a special sweep control circuit. Sample throughput is 6 to 12 samples per day. Operating instructions are also given

  19. A highly sensitive and specific assay for vertebrate collagenase

    International Nuclear Information System (INIS)

    Sodek, J.; Hurum, S.; Feng, J.

    1981-01-01

    A highly sensitive and specific assay for vertebrate collagenase has been developed using a [ 14 C]-labeled collagen substrate and a combination of SDS-PAGE (sodium dodecyl sulfate-polyacrylamide gel electrophoresis) and fluorography to identify and quantitate the digestion products. The assay was sufficiently sensitive to permit the detection and quantitation of collagenase activity in 0.1 μl of gingival sulcal fluid, and in samples of cell culture medium without prior concentration. The assay has also been used to detect the presence of inhibitors of collagenolytic enzymes in various cell culture fluids. (author)

  20. Enhanced Enzymatic Production of Cephalexin at High Substrate Concentration with in situ Product Removal by Complexation

    Directory of Open Access Journals (Sweden)

    Dengchao Li

    2008-01-01

    Full Text Available Cephalexin (CEX was synthesized with 7-amino-3-deacetoxycephalosporanic acid (7-ADCA and D(–-phenylglycine methyl ester (PGME using immobilized penicillin G acylase from Escherichia coli. It was found that substrate concentration and in situ product could remarkably influence the ratio of synthesis to hydrolysis (S/H and the efficiency of CEX synthesis. The optimal ratio of enzyme to substrate was 65 IU/mM 7-ADCA. High substrate concentration improved the 7-ADCA conversion from 61 to 81 % in the process without in situ product removal (ISPR, while in the synthetic process with ISPR, high substrate concentration increased the 7-ADCA conversion from 88 to 98 %. CEX was easily separated from CEX/β-naphthol complex and its purity and overall yield were 99 and 70 %, respectively.

  1. Are inflationary predictions sensitive to very high energy physics?

    International Nuclear Information System (INIS)

    Burgess, C.P.; Lemieux, F.; Holman, R.; Cline, J.M.

    2003-01-01

    It has been proposed that the successful inflationary description of density perturbations on cosmological scales is sensitive to the details of physics at extremely high (trans-Planckian) energies. We test this proposal by examining how inflationary predictions depend on higher-energy scales within a simple model where the higher-energy physics is well understood. We find the best of all possible worlds: inflationary predictions are robust against the vast majority of high-energy effects, but can be sensitive to some effects in certain circumstances, in a way which does not violate ordinary notions of decoupling. This implies both that the comparison of inflationary predictions with CMB data is meaningful, and that it is also worth searching for small deviations from the standard results in the hopes of learning about very high energies. (author)

  2. Design of highly sensitive multichannel bimetallic photonic crystal fiber biosensor

    Science.gov (United States)

    Hameed, Mohamed Farhat O.; Alrayk, Yassmin K. A.; Shaalan, Abdelhamid A.; El Deeb, Walid S.; Obayya, Salah S. A.

    2016-10-01

    A design of a highly sensitive multichannel biosensor based on photonic crystal fiber is proposed and analyzed. The suggested design has a silver layer as a plasmonic material coated by a gold layer to protect silver oxidation. The reported sensor is based on detection using the quasi transverse electric (TE) and quasi transverse magnetic (TM) modes, which offers the possibility of multichannel/multianalyte sensing. The numerical results are obtained using a finite element method with perfect matched layer boundary conditions. The sensor geometrical parameters are optimized to achieve high sensitivity for the two polarized modes. High-refractive index sensitivity of about 4750 nm/RIU (refractive index unit) and 4300 nm/RIU with corresponding resolutions of 2.1×10-5 RIU, and 2.33×10-5 RIU can be obtained according to the quasi TM and quasi TE modes of the proposed sensor, respectively. Further, the reported design can be used as a self-calibration biosensor within an unknown analyte refractive index ranging from 1.33 to 1.35 with high linearity and high accuracy. Moreover, the suggested biosensor has advantages in terms of compactness and better integration of microfluidics setup, waveguide, and metallic layers into a single structure.

  3. Monitoring microstructural evolution in-situ during cyclic deformation by high resolution reciprocal space mapping

    DEFF Research Database (Denmark)

    Diederichs, Annika Martina; Thiel, Felix; Fischer, Torben

    2017-01-01

    The recently developed synchrotron technique High Resolution Reciprocal Space Mapping (HRRSM) is used to characterize the deformation structures evolving during cyclic deformation of commercially pure, polycrystalline aluminium AA1050. Insight into the structural reorganization within single grains...... is gained by in-situ monitoring of the microstructural evolution during cyclic deformation. By HRRSM, a large number of individual subgrains can be resolved within individual grains in the bulk of polycrystalline specimens and their fate, their individual orientation and elastic stresses, tracked during...

  4. Using Satellites to Investigate the Sensitivity of Longwave Downward Radiation to Water Vapor at High Elevations

    Science.gov (United States)

    Naud, Catherine M.; Miller, James R.; Landry, Chris

    2012-01-01

    Many studies suggest that high-elevation regions may be among the most sensitive to future climate change. However, in situ observations in these often remote locations are too sparse to determine the feedbacks responsible for enhanced warming rates. One of these feedbacks is associated with the sensitivity of longwave downward radiation (LDR) to changes in water vapor, with the sensitivity being particularly large in many high-elevation regions where the average water vapor is often low. We show that satellite retrievals from the Moderate Resolution Imaging Spectroradiometer (MODIS) and Clouds and the Earth's Radiant Energy System (CERES) can be used to expand the current ground-based observational database and that the monthly averaged clear-sky satellite estimates of humidity and LDR are in good agreement with the well-instrumented Center for Snow and Avalanche Studies ground-based site in the southwestern Colorado Rocky Mountains. The relationship between MODIS-retrieved precipitable water vapor and surface specific humidity across the contiguous United States was found to be similar to that previously found for the Alps. More important, we show that satellites capture the nonlinear relationship between LDR and water vapor and confirm that LDR is especially sensitive to changes in water vapor at high elevations in several midlatitude mountain ranges. Because the global population depends on adequate fresh water, much of which has its source in high mountains, it is critically important to understand how climate will change there. We demonstrate that satellites can be used to investigate these feedbacks in high-elevation regions where the coverage of surface-based observations is insufficient to do so.

  5. Determination of Chlorinated Hydrocarbons in Water Using Highly Sensitive Mid-Infrared Sensor Technology

    Science.gov (United States)

    Lu, Rui; Mizaikoff, Boris; Li, Wen-Wei; Qian, Chen; Katzir, Abraham; Raichlin, Yosef; Sheng, Guo-Ping; Yu, Han-Qing

    2013-08-01

    Chlorinated aliphatic hydrocarbons and chlorinated aromatic hydrocarbons (CHCs) are toxic and carcinogenic contaminants commonly found in environmental samples, and efficient online detection of these contaminants is still challenging at the present stage. Here, we report an advanced Fourier transform infrared spectroscopy-attenuated total reflectance (FTIR-ATR) sensor for in-situ and simultaneous detection of multiple CHCs, including monochlorobenzene, 1,2-dichlorobenzene, 1,3-dichlorobenzene, trichloroethylene, perchloroethylene, and chloroform. The polycrystalline silver halide sensor fiber had a unique integrated planar-cylindric geometry, and was coated with an ethylene/propylene copolymer membrane to act as a solid phase extractor, which greatly amplified the analytical signal and contributed to a higher detection sensitivity compared to the previously reported sensors. This system exhibited a high detection sensitivity towards the CHCs mixture at a wide concentration range of 5~700 ppb. The FTIR-ATR sensor described in this study has a high potential to be utilized as a trace-sensitive on-line device for water contamination monitoring.

  6. In situ flash x-ray high-speed computed tomography for the quantitative analysis of highly dynamic processes

    Science.gov (United States)

    Moser, Stefan; Nau, Siegfried; Salk, Manfred; Thoma, Klaus

    2014-02-01

    The in situ investigation of dynamic events, ranging from car crash to ballistics, often is key to the understanding of dynamic material behavior. In many cases the important processes and interactions happen on the scale of milli- to microseconds at speeds of 1000 m s-1 or more. Often, 3D information is necessary to fully capture and analyze all relevant effects. High-speed 3D-visualization techniques are thus required for the in situ analysis. 3D-capable optical high-speed methods often are impaired by luminous effects and dust, while flash x-ray based methods usually deliver only 2D data. In this paper, a novel 3D-capable flash x-ray based method, in situ flash x-ray high-speed computed tomography is presented. The method is capable of producing 3D reconstructions of high-speed processes based on an undersampled dataset consisting of only a few (typically 3 to 6) x-ray projections. The major challenges are identified, discussed and the chosen solution outlined. The application is illustrated with an exemplary application of a 1000 m s-1 high-speed impact event on the scale of microseconds. A quantitative analysis of the in situ measurement of the material fragments with a 3D reconstruction with 1 mm voxel size is presented and the results are discussed. The results show that the HSCT method allows gaining valuable visual and quantitative mechanical information for the understanding and interpretation of high-speed events.

  7. In-situ investigations of structural changes during cyclic loading by high resolution reciprocal space mapping

    DEFF Research Database (Denmark)

    Diederichs, Annika M.; Thiel, Felix; Lienert, Ulrich

    2017-01-01

    dislocation structures can be identified using advanced electron microscopy and synchrotron techniques. A detailed characterization of the microstructure during cyclic loading by in-situ monitoring the internal structure within individual grains with high energy x-rays can help to understand and predict...... the materials behavior during cyclic deformation and to improve the material design. While monitoring macroscopic stress and strain during cyclic loading, reciprocal space maps of diffraction peaks from single grains are obtained with high resolution. High Resolution Reciprocal Space Mapping was applied...

  8. Development of High Sensitivity Nuclear Emulsion and Fine Grained Emulsion

    Science.gov (United States)

    Kawahara, H.; Asada, T.; Naka, T.; Naganawa, N.; Kuwabara, K.; Nakamura, M.

    2014-08-01

    Nuclear emulsion is a particle detector having high spacial resolution and angular resolution. It became useful for large statistics experiment thanks to the development of automatic scanning system. In 2010, a facility for emulsion production was introduced and R&D of nuclear emulsion began at Nagoya university. In this paper, we present results of development of the high sensitivity emulsion and fine grained emulsion for dark matter search experiment. Improvement of sensitivity is achieved by raising density of silver halide crystals and doping well-adjusted amount of chemicals. Production of fine grained emulsion was difficult because of unexpected crystal condensation. By mixing polyvinyl alcohol (PVA) to gelatin as a binder, we succeeded in making a stable fine grained emulsion.

  9. Development of High Sensitivity Nuclear Emulsion and Fine Grained Emulsion

    International Nuclear Information System (INIS)

    Kawahara, H.; Asada, T.; Naka, T.; Naganawa, N.; Kuwabara, K.; Nakamura, M.

    2014-01-01

    Nuclear emulsion is a particle detector having high spacial resolution and angular resolution. It became useful for large statistics experiment thanks to the development of automatic scanning system. In 2010, a facility for emulsion production was introduced and R and D of nuclear emulsion began at Nagoya university. In this paper, we present results of development of the high sensitivity emulsion and fine grained emulsion for dark matter search experiment. Improvement of sensitivity is achieved by raising density of silver halide crystals and doping well-adjusted amount of chemicals. Production of fine grained emulsion was difficult because of unexpected crystal condensation. By mixing polyvinyl alcohol (PVA) to gelatin as a binder, we succeeded in making a stable fine grained emulsion

  10. Online high sensitivity measurement system for transuranic aerosols

    International Nuclear Information System (INIS)

    Kordas, J.F.; Phelps, P.L.

    1976-01-01

    A measurement system for transuranic aerosols has been designed that will be able to withstand the corrosive nature of stack effluents and yet have extremely high sensitivity. It will be capable of measuring 1 maximum permissible concentration (MPC) of plutonium or americium in 30 minutes with a fractional standard deviation of less than 0.33. Background resulting from 218 Po is eliminated by alpha energy discrimination and a decay scheme analysis. A microprocessor controls all data acquisition, data reduction, and instrument calibration

  11. Recent trends in high spin sensitivity magnetic resonance

    Science.gov (United States)

    Blank, Aharon; Twig, Ygal; Ishay, Yakir

    2017-07-01

    new ideas, show how these limiting factors can be mitigated to significantly improve the sensitivity of induction detection. Finally, we outline some directions for the possible applications of high-sensitivity induction detection in the field of electron spin resonance.

  12. High-sensitivity bend angle measurements using optical fiber gratings.

    Science.gov (United States)

    Rauf, Abdul; Zhao, Jianlin; Jiang, Biqiang

    2013-07-20

    We present a high-sensitivity and more flexible bend measurement method, which is based on the coupling of core mode to the cladding modes at the bending region in concatenation with optical fiber grating serving as band reflector. The characteristics of a bend sensing arm composed of bending region and optical fiber grating is examined for different configurations including single fiber Bragg grating (FBG), chirped FBG (CFBG), and double FBGs. The bend loss curves for coated, stripped, and etched sections of fiber in the bending region with FBG, CFBG, and double FBG are obtained experimentally. The effect of separation between bending region and optical fiber grating on loss is measured. The loss responses for single FBG and CFBG configurations are compared to discover the effectiveness for practical applications. It is demonstrated that the sensitivity of the double FBG scheme is twice that of the single FBG and CFBG configurations, and hence acts as sensitivity multiplier. The bend loss response for different fiber diameters obtained through etching in 40% hydrofluoric acid, is measured in double FBG scheme that resulted in a significant increase in the sensitivity, and reduction of dead-zone.

  13. Towards highly sensitive strain sensing based on nanostructured materials

    International Nuclear Information System (INIS)

    Dao, Dzung Viet; Nakamura, Koichi; Sugiyama, Susumu; Bui, Tung Thanh; Dau, Van Thanh; Yamada, Takeo; Hata, Kenji

    2010-01-01

    This paper presents our recent theoretical and experimental study of piezo-effects in nanostructured materials for highly sensitive, high resolution mechanical sensors. The piezo-effects presented here include the piezoresistive effect in a silicon nanowire (SiNW) and single wall carbon nanotube (SWCNT) thin film, as well as the piezo-optic effect in a Si photonic crystal (PhC) nanocavity. Firstly, the electronic energy band structure of the silicon nanostructure is discussed and simulated by using the First-Principles Calculations method. The result showed a remarkably different energy band structure compared with that of bulk silicon. This difference in the electronic state will result in different physical, chemical, and therefore, sensing properties of silicon nanostructures. The piezoresistive effects of SiNW and SWCNT thin film were investigated experimentally. We found that, when the width of ( 110 ) p-type SiNW decreases from 500 to 35 nm, the piezoresistive effect increases by more than 60%. The longitudinal piezoresistive coefficient of SWCNT thin film was measured to be twice that of bulk p-type silicon. Finally, theoretical investigations of the piezo-optic effect in a PhC nanocavity based on Finite Difference Time Domain (FDTD) showed extremely high resolution strain sensing. These nanostructures were fabricated based on top-down nanofabrication technology. The achievements of this work are significant for highly sensitive, high resolution and miniaturized mechanical sensors

  14. In-situ polymerization of polyaniline on the surface of graphene oxide for high electrochemical capacitance

    International Nuclear Information System (INIS)

    Li, Xinlu; Zhong, Qineng; Zhang, Xinlin; Li, Tongtao; Huang, Jiamu

    2015-01-01

    Conducting polymer polyaniline (PANI) was in-situ polymerized on the surface of graphene oxide (GO) to form PANI encapsulating GO nanocomposites. The morphology and microstructure were examined by scanning electron microscopy, X-ray diffraction and N 2 absorption/desorption analysis. Electrochemical properties were tested by cyclic voltammetry, galvanostatic charge/discharge cycles and electrochemical impedance spectroscopy. Experimental results showed that ethanol assisted the dispersion of GO in water and facilitated the diffusion of polymer monomers on GO. GO as a support material can provide sufficient reaction sites for the deposition of aniline to form the film-like GO/PANI composites. Capacitive performance illustrated that the in-situ polymerization of PANI on GO was effective in improving the specific capacitance and cycling stability. - Highlights: • GO/PANI nanocomposites were achieved by in-situ polymerization. • PANI was uniformly coated on the surface of GO with addition of ethanol. • GO/PANI show high specific capacitance and cycling stability

  15. High sensitivity tests of the standard model for electroweak interactions

    International Nuclear Information System (INIS)

    Koetke, D.D.

    1992-01-01

    The work done on this project was focussed mainly on LAMPF experiment E969 known as the MEGA experiment, a high sensitivity search for the lepton family number violating decay μ → eγ to a sensitivity which, measured in terms of the branching ratio, BR = [μ→eγ]/[μ→e ν μ ν e ] ∼10 -13 is over two orders of magnitude better than previously reported values. The work done on MEGA during this period was divided between that done at Valparaiso University and that done at LAMPF. In addition, some contributions were made to a proposal to the LAMPF PAC to perform a precision measurement of the Michel ρ parameter, described below

  16. High sensitivity tests of the standard model for electroweak interactions

    International Nuclear Information System (INIS)

    1994-01-01

    The work done on this project focused on two LAMPF experiments. The MEGA experiment is a high-sensitivity search for the lepton family number violating decay μ → eγ to a sensitivity which, measured in terms of the branching ratio, BR = [μ → eγ]/[μ eν μ ν e ] ∼ 10 -13 , will be over two orders of magnitude better than previously reported values. The second is a precision measurement of the Michel ρ parameter from the positron energy spectrum of μ → eν μ ν e to test the predictions V-A theory of weak interactions. In this experiment the uncertainty in the measurement of the Michel ρ parameter is expected to be a factor of three lower than the present reported value. The detectors are operational, and data taking has begun

  17. High sensitivity tests of the standard model for electroweak interactions

    International Nuclear Information System (INIS)

    Koetke, D.D.; Manweiler, R.W.; Shirvel Stanislaus, T.D.

    1993-01-01

    The work done on this project was focused on two LAMPF experiments. The MEGA experiment, a high-sensitivity search for the lepton-family-number-violating decay μ → e γ to a sensitivity which, measured in terms of the branching ratio, BR = [μ → e γ]/[μ → ev μ v e ] ∼ 10 -13 , is over two orders of magnitude better than previously reported values. The second is a precision measurement of the Michel ρ parameter from the positron energy spectrum of μ → ev μ v e to test the V-A theory of weak interactions. The uncertainty in the measurement of the Michel ρ parameter is expected to be a factor of three lower than the present reported value

  18. High sensitive quench detection method using an integrated test wire

    International Nuclear Information System (INIS)

    Fevrier, A.; Tavergnier, J.P.; Nithart, H.; Kiblaire, M.; Duchateau, J.L.

    1981-01-01

    A high sensitive quench detection method which works even in the presence of an external perturbing magnetic field is reported. The quench signal is obtained from the difference in voltages at the superconducting winding terminals and at the terminals at a secondary winding strongly coupled to the primary. The secondary winding could consist of a ''zero-current strand'' of the superconducting cable not connected to one of the winding terminals or an integrated normal test wire inside the superconducting cable. Experimental results on quench detection obtained by this method are described. It is shown that the integrated test wire method leads to efficient and sensitive quench detection, especially in the presence of an external perturbing magnetic field

  19. Development of miniature γ dose rate monitor with high sensitivity

    International Nuclear Information System (INIS)

    Shi Huilu; Tuo Xianguo; Xi Dashun; Tang Rong; Mu Keliang; Yang Jianbo

    2009-01-01

    This paper introduces a miniature γ dose rate monitor with high sensitivity which design based on single chip microcomputer, it can continue monitoring γ dose rate and then choose wire or wireless communications to sent the monitoring data to host according to the actual conditions. It has two kinds of power supply system, AC power supply system and battery which can be chose by concrete circumstances. The design idea and implementation technology of hardware and software and the system structure of the monitor are detailed illustrated in this paper. The experimental results show that measurable range is 0.1 mR/h-200 mR/h, the sensitivity of γ is 90 cps/mR/h, dead time below 200 us, error of stability below ±10%. (authors)

  20. Polymer-Particle Pressure-Sensitive Paint with High Photostability

    Directory of Open Access Journals (Sweden)

    Yu Matsuda

    2016-04-01

    Full Text Available We propose a novel fast-responding and paintable pressure-sensitive paint (PSP based on polymer particles, i.e. polymer-particle (pp-PSP. As a fast-responding PSP, polymer-ceramic (PC-PSP is widely studied. Since PC-PSP generally consists of titanium (IV oxide (TiO2 particles, a large reduction in the luminescent intensity will occur due to the photocatalytic action of TiO2. We propose the usage of polymer particles instead of TiO2 particles to prevent the reduction in the luminescent intensity. Here, we fabricate pp-PSP based on the polystyrene particle with a diameter of 1 μm, and investigate the pressure- and temperature-sensitives, the response time, and the photostability. The performances of pp-PSP are compared with those of PC-PSP, indicating the high photostability with the other characteristics comparable to PC-PSP.

  1. In situ determination of a rock mass modulus using a high resolution tiltmeter

    Energy Technology Data Exchange (ETDEWEB)

    Saleh, B.; Husein Malkawi, A.I. [University of Jordan, Amman (Jordan); Blum, P.A. [Universite Pierre et Marie Curie, 75 - Paris (France)

    1996-04-01

    A very sensitive, compact tiltmeter made of melted silica, developed for the measurement of small deformations of various civil engineering structures, was described. The instrument is capable of giving a continuous record and was used to establish a new approach to directly evaluating the in situ average elastic rock mass modulus. Such information is important in decision making during the design stages of large civil engineering works, such as dams, nuclear plant facilities, and underground structures. Five tiltmeters were installed on the facades of the Louvre in Paris to study the deformation induced by internal structural work and by the impact of the Paris metro traffic movement. The data was used to determine displacement using the Boussinesq equation. Results were consistent with typical elastic rock-mass modulus for the rock found in the museum`s foundations. 13 refs., 1 tab., 10 figs.

  2. Field test investigation of high sensitivity fiber optic seismic geophone

    Science.gov (United States)

    Wang, Meng; Min, Li; Zhang, Xiaolei; Zhang, Faxiang; Sun, Zhihui; Li, Shujuan; Wang, Chang; Zhao, Zhong; Hao, Guanghu

    2017-10-01

    Seismic reflection, whose measured signal is the artificial seismic waves ,is the most effective method and widely used in the geophysical prospecting. And this method can be used for exploration of oil, gas and coal. When a seismic wave travelling through the Earth encounters an interface between two materials with different acoustic impedances, some of the wave energy will reflect off the interface and some will refract through the interface. At its most basic, the seismic reflection technique consists of generating seismic waves and measuring the time taken for the waves to travel from the source, reflect off an interface and be detected by an array of geophones at the surface. Compared to traditional geophones such as electric, magnetic, mechanical and gas geophone, optical fiber geophones have many advantages. Optical fiber geophones can achieve sensing and signal transmission simultaneously. With the development of fiber grating sensor technology, fiber bragg grating (FBG) is being applied in seismic exploration and draws more and more attention to its advantage of anti-electromagnetic interference, high sensitivity and insensitivity to meteorological conditions. In this paper, we designed a high sensitivity geophone and tested its sensitivity, based on the theory of FBG sensing. The frequency response range is from 10 Hz to 100 Hz and the acceleration of the fiber optic seismic geophone is over 1000pm/g. sixteen-element fiber optic seismic geophone array system is presented and the field test is performed in Shengli oilfield of China. The field test shows that: (1) the fiber optic seismic geophone has a higher sensitivity than the traditional geophone between 1-100 Hz;(2) The low frequency reflection wave continuity of fiber Bragg grating geophone is better.

  3. A CMOS In-Pixel CTIA High Sensitivity Fluorescence Imager.

    Science.gov (United States)

    Murari, Kartikeya; Etienne-Cummings, Ralph; Thakor, Nitish; Cauwenberghs, Gert

    2011-10-01

    Traditionally, charge coupled device (CCD) based image sensors have held sway over the field of biomedical imaging. Complementary metal oxide semiconductor (CMOS) based imagers so far lack sensitivity leading to poor low-light imaging. Certain applications including our work on animal-mountable systems for imaging in awake and unrestrained rodents require the high sensitivity and image quality of CCDs and the low power consumption, flexibility and compactness of CMOS imagers. We present a 132×124 high sensitivity imager array with a 20.1 μm pixel pitch fabricated in a standard 0.5 μ CMOS process. The chip incorporates n-well/p-sub photodiodes, capacitive transimpedance amplifier (CTIA) based in-pixel amplification, pixel scanners and delta differencing circuits. The 5-transistor all-nMOS pixel interfaces with peripheral pMOS transistors for column-parallel CTIA. At 70 fps, the array has a minimum detectable signal of 4 nW/cm(2) at a wavelength of 450 nm while consuming 718 μA from a 3.3 V supply. Peak signal to noise ratio (SNR) was 44 dB at an incident intensity of 1 μW/cm(2). Implementing 4×4 binning allowed the frame rate to be increased to 675 fps. Alternately, sensitivity could be increased to detect about 0.8 nW/cm(2) while maintaining 70 fps. The chip was used to image single cell fluorescence at 28 fps with an average SNR of 32 dB. For comparison, a cooled CCD camera imaged the same cell at 20 fps with an average SNR of 33.2 dB under the same illumination while consuming over a watt.

  4. Highly sensitive detection of urinary cadmium to assess personal exposure

    Energy Technology Data Exchange (ETDEWEB)

    Argun, Avni A.; Banks, Ashley M.; Merlen, Gwendolynne; Tempelman, Linda A. [Giner, Inc., 89 Rumford Ave., Newton 02466, MA United States (United States); Becker, Michael F.; Schuelke, Thomas [Fraunhofer USA – CCL, 1449 Engineering Research Ct., East Lansing 48824, MI (United States); Dweik, Badawi M., E-mail: bdweik@ginerinc.com [Giner, Inc., 89 Rumford Ave., Newton 02466, MA United States (United States)

    2013-04-22

    Highlights: ► An electrochemical sensor capable of detecting cadmium at parts-per-billion levels in urine. ► A novel fabrication method for Boron-Doped Diamond (BDD) ultramicroelectrode (UME) arrays. ► Unique combination of BDD UME arrays and a differential pulse voltammetry algorithm. ► High sensitivity, high reproducibility, and very low noise levels. ► Opportunity for portable operation to assess on-site personal exposure. -- Abstract: A series of Boron-Doped Diamond (BDD) ultramicroelectrode arrays were fabricated and investigated for their performance as electrochemical sensors to detect trace level metals such as cadmium. The steady-state diffusion behavior of these sensors was validated using cyclic voltammetry followed by electrochemical detection of cadmium in water and in human urine to demonstrate high sensitivity (>200 μA ppb{sup −1} cm{sup −2}) and low background current (<4 nA). When an array of ultramicroelectrodes was positioned with optimal spacing, these BDD sensors showed a sigmoidal diffusion behavior. They also demonstrated high accuracy with linear dose dependence for quantification of cadmium in a certified reference river water sample from the U.S. National Institute of Standards and Technology (NIST) as well as in a human urine sample spiked with 0.25–1 ppb cadmium.

  5. Differential ontogenetic patterns of levocabastine-sensitive neurotensin NT2 receptors and of NT1 receptors in the rat brain revealed by in situ hybridization.

    Science.gov (United States)

    Lépée-Lorgeoux, I; Betancur, C; Rostène, W; Pélaprat, D

    1999-03-12

    The postnatal ontogeny of the levocabastine-sensitive neurotensin receptor (NT2) mRNA was studied by in situ hybridization in the rat brain and compared with the distribution of the levocabastine-insensitive NT1 receptor. NT2 receptor mRNA was absent at birth from all brain structures except the ependymal cell layer lining the ventricles. The development of NT2 receptor mRNA followed three ontogenetic patterns. The first pattern, involving the majority of the cerebral gray matter, was characterized by a continuous increase from postnatal day 5 (P5) to P30. The second one, involving regions rich in myelinated fibers such as the corpus callosum and lacunosum moleculare layer of the hippocampus, exhibited a pronounced increase between P5 and P10, peaked at P15 and was followed by a plateau or a slight decrease. The third pattern was observed in the ependymal cell layer lining the olfactory and lateral ventricles, where the high labeling already present at birth continued to increase during development. These different developmental patterns could reflect the variety of cells expressing NT2 receptor mRNA, including neurons, protoplasmic astrocytes in gray matter, fibrous astrocytes present in myelinated fibers tracts, and ependymal cells. In contrast, NT1 receptor mRNA, which seems to be associated only with neurons, was highly and transiently expressed during the perinatal period in the cerebral cortex, hippocampus and striatal neuroepithelium. Other regions, notably the ventral tegmental area and substantia nigra compacta, exhibited a gradual increase in NT1 receptor signal, reaching adult levels by P21. Both the differential localization and ontogenetic profiles of NT1 and NT2 receptor mRNAs suggest different involvement of these two receptors in brain functions and development. Copyright 1999 Elsevier Science B.V.

  6. High order effects in cross section sensitivity analysis

    International Nuclear Information System (INIS)

    Greenspan, E.; Karni, Y.; Gilai, D.

    1978-01-01

    Two types of high order effects associated with perturbations in the flux shape are considered: Spectral Fine Structure Effects (SFSE) and non-linearity between changes in performance parameters and data uncertainties. SFSE are investigated in Part I using a simple single resonance model. Results obtained for each of the resolved and for representative unresolved resonances of 238 U in a ZPR-6/7 like environment indicate that SFSE can have a significant contribution to the sensitivity of group constants to resonance parameters. Methods to account for SFSE both for the propagation of uncertainties and for the adjustment of nuclear data are discussed. A Second Order Sensitivity Theory (SOST) is presented, and its accuracy relative to that of the first order sensitivity theory and of the direct substitution method is investigated in Part II. The investigation is done for the non-linear problem of the effect of changes in the 297 keV sodium minimum cross section on the transport of neutrons in a deep-penetration problem. It is found that the SOST provides a satisfactory accuracy for cross section uncertainty analysis. For the same degree of accuracy, the SOST can be significantly more efficient than the direct substitution method

  7. Operationalization of the Russian Version of Highly Sensitive Person Scale

    Directory of Open Access Journals (Sweden)

    Регина Вячеславовна Ершова

    2018-12-01

    Full Text Available The aim of the present study was to operationalize a Russian version of the Highly Sensitive Person Scale (HSPS. The empirical data were collected in two ways: active, through oral advertising and inviting those who wish to take part in the study (snowball technique and passive (placement of ads about taking part in a research in social networks VKontakte and Facebook. As a result, 350 university students (117 men, 233 women, an average age of 18,2 (± 1,7 applied to a research laboratory and filled out the HSPS questionnaire, and another 510 respondents (380 women, 130 men, average age 22,6 ( ± 7,9 filled the HSPS online. The results of the study did not confirm the one-dimensional model of the construct, proposed by Aron & Aron (1997, as well as the most commonly used in the English-language studies three-factor solution. The hierarchical claster and confirmatory analyses used in the operationalization procedure allowed us to conclude that the variance of the Russian version of HSPS is best described in the framework of a two-factor model including the two separate subscales: Ease of Excitation (EOE, Low threshold of sensitivity (LTS. Sensory Processing Sensitivity may be defined as an increased susceptibility to external and internal stimuli, realized through negative emotional responses and deep susceptibility (distress to excessive stimulation.

  8. A wide-bandwidth and high-sensitivity robust microgyroscope

    International Nuclear Information System (INIS)

    Sahin, Korhan; Sahin, Emre; Akin, Tayfun; Alper, Said Emre

    2009-01-01

    This paper reports a microgyroscope design concept with the help of a 2 degrees of freedom (DoF) sense mode to achieve a wide bandwidth without sacrificing mechanical and electronic sensitivity and to obtain robust operation against variations under ambient conditions. The design concept is demonstrated with a tuning fork microgyroscope fabricated with an in-house silicon-on-glass micromachining process. When the fabricated gyroscope is operated with a relatively wide bandwidth of 1 kHz, measurements show a relatively high raw mechanical sensitivity of 131 µV (° s −1 ) −1 . The variation in the amplified mechanical sensitivity (scale factor) of the gyroscope is measured to be less than 0.38% for large ambient pressure variations such as from 40 to 500 mTorr. The bias instability and angle random walk of the gyroscope are measured to be 131° h −1 and 1.15° h −1/2 , respectively

  9. Development of an underwater high sensitivity Cherenkov detector: Sea Urchin

    International Nuclear Information System (INIS)

    Camerini, U.; McGibney, D.; Roberts, A.

    1982-01-01

    The need for a high gain, high sensitivity Cherenkov light sensor to be used in a deep underwater muon and neutrino detector (DUMAND) array has led to the design of the Sea Urchin detector. In this design a spherical photocathode PMTis optically coupled through a glass hemisphere to a large number of glass spines, each of which is filled with a wavelength-shifting (WLS) solution of a high quantum efficiency phosphor. The Cherenkov radiation is absorbed in the spine, isotropically re-radiated at a longer wavelength, and a fraction of the fluorescent light is internally reflected in the spine, and guided to the photomultiplier concentrically located in the glass hemisphere. Experiments measuring the optical characteristics of the spines and computer programs simulating light transformation and detection cross sections are described. Overall optical gains in the range 5-10 are achieved. The WLS solution is inexpensive, and may have other applications. (orig.)

  10. Position sensitive detection of neutrons in high radiation background field.

    Science.gov (United States)

    Vavrik, D; Jakubek, J; Pospisil, S; Vacik, J

    2014-01-01

    We present the development of a high-resolution position sensitive device for detection of slow neutrons in the environment of extremely high γ and e(-) radiation background. We make use of a planar silicon pixelated (pixel size: 55 × 55 μm(2)) spectroscopic Timepix detector adapted for neutron detection utilizing very thin (10)B converter placed onto detector surface. We demonstrate that electromagnetic radiation background can be discriminated from the neutron signal utilizing the fact that each particle type produces characteristic ionization tracks in the pixelated detector. Particular tracks can be distinguished by their 2D shape (in the detector plane) and spectroscopic response using single event analysis. A Cd sheet served as thermal neutron stopper as well as intensive source of gamma rays and energetic electrons. Highly efficient discrimination was successful even at very low neutron to electromagnetic background ratio about 10(-4).

  11. Highly Sensitive Flexible Magnetic Sensor Based on Anisotropic Magnetoresistance Effect.

    Science.gov (United States)

    Wang, Zhiguang; Wang, Xinjun; Li, Menghui; Gao, Yuan; Hu, Zhongqiang; Nan, Tianxiang; Liang, Xianfeng; Chen, Huaihao; Yang, Jia; Cash, Syd; Sun, Nian-Xiang

    2016-11-01

    A highly sensitive flexible magnetic sensor based on the anisotropic magnetoresistance effect is fabricated. A limit of detection of 150 nT is observed and excellent deformation stability is achieved after wrapping of the flexible sensor, with bending radii down to 5 mm. The flexible AMR sensor is used to read a magnetic pattern with a thickness of 10 μm that is formed by ferrite magnetic inks. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. High sensitivity on-line monitor for radioactive effluent

    Energy Technology Data Exchange (ETDEWEB)

    Sasaki, Toshimi [Tohoku Electric Power Co. Ltd., Sendai (Japan); Ishizuka, Akira; Abe, Eisuke; Inoue, Yasuhiko; Fujii, Masaaki; Kitaguchi, Hiroshi; Doi, Akira

    1983-04-01

    A new approach for a highly sensitive effluent monitor is presented. The free flow type monitor, which consists of a straightener, nozzle, monitoring section and ..gamma..-ray detector, is demonstrated to be effective in providing long term stability. The 160 start-and-stop cycles of effluent discharge were repeated in a 120-h testing period. Results showed a background increase was not observed for the free flow type monitor. The background count rate was calibrated to the lowest detection limit to be 2.2 x 10/sup -2/ Bq/ml for a 300 s measurement time.

  13. High-Sensitivity Measurement of Density by Magnetic Levitation.

    Science.gov (United States)

    Nemiroski, Alex; Kumar, A A; Soh, Siowling; Harburg, Daniel V; Yu, Hai-Dong; Whitesides, George M

    2016-03-01

    This paper presents methods that use Magnetic Levitation (MagLev) to measure very small differences in density of solid diamagnetic objects suspended in a paramagnetic medium. Previous work in this field has shown that, while it is a convenient method, standard MagLev (i.e., where the direction of magnetization and gravitational force are parallel) cannot resolve differences in density mm) because (i) objects close in density prevent each other from reaching an equilibrium height due to hard contact and excluded volume, and (ii) using weaker magnets or reducing the magnetic susceptibility of the medium destabilizes the magnetic trap. The present work investigates the use of weak magnetic gradients parallel to the faces of the magnets as a means of increasing the sensitivity of MagLev without destabilization. Configuring the MagLev device in a rotated state (i.e., where the direction of magnetization and gravitational force are perpendicular) relative to the standard configuration enables simple measurements along the axes with the highest sensitivity to changes in density. Manipulating the distance of separation between the magnets or the lengths of the magnets (along the axis of measurement) enables the sensitivity to be tuned. These modifications enable an improvement in the resolution up to 100-fold over the standard configuration, and measurements with resolution down to 10(-6) g/cm(3). Three examples of characterizing the small differences in density among samples of materials having ostensibly indistinguishable densities-Nylon spheres, PMMA spheres, and drug spheres-demonstrate the applicability of rotated Maglev to measuring the density of small (0.1-1 mm) objects with high sensitivity. This capability will be useful in materials science, separations, and quality control of manufactured objects.

  14. In situ polymerization of highly dispersed polypyrrole on reduced graphite oxide for dopamine detection.

    Science.gov (United States)

    Qian, Tao; Yu, Chenfei; Wu, Shishan; Shen, Jian

    2013-12-15

    A composite consisting of reduced graphite oxide and highly dispersed polypyrrole nanospheres was synthesized by a straightforward technique, by in situ chemical oxidative polymerization. The novel polypyrrole nanospheres can prevent the aggregation of reduced graphite oxide sheets by electrostatic repulsive interaction, and enhance their electrochemical properties in the nano-molar measurement of dopamine in biological systems with a linear range of 1-8000 nM and a detection limit as low as 0.3 nM. © 2013 Elsevier B.V. All rights reserved.

  15. In-situ heater test in sedimentary soft rocks under high temperature (Phase I)

    International Nuclear Information System (INIS)

    Ikenoya, Takafumi; Takakura, Nozomu; Okada, Tetsuji; Sawada, Masataka; Hirano, Kouhei; Tani, Kazuo

    2008-01-01

    Various researches have been conducted on high level radioactive waste geological disposal in sedimentary soft rocks. It's noted that the long-term mechanical behaviors of sedimentary soft rocks can be affected by various environmental factors such as temperatures or hydraulic conditions. Therefore, in-situ heater test was conducted in an underground cavern at a depth of 50 meters for the purpose of improving thermo-hydro-mechanical coupled analysis code. This report presents the test result demonstrating the changes of temperature and strain distributions with time at the elevated temperature of the heater up to 40 degrees Celsius. (author)

  16. Experimental Investigation of In Situ Cleanable or Regenerative Filters for High Level Radioactive Waste Tanks

    International Nuclear Information System (INIS)

    Adamson, D.J.

    2000-01-01

    The Westinghouse Savannah River Company, located at the Savannah River Site (SRS) in Aiken, South Carolina, is currently testing two types of filter media for application as in situ regenerable/cleanable filters on high-level radioactive liquid waste tanks. Each of the 1.3 million-gallon tanks is equipped with an exhaust ventilation system to provide tank ventilation and to maintain the tank contents at approximately 1-in. water gauge vacuum to prevent the release of radioactive material to the environment. These systems are equipped with conventional, disposable, glass-fiber, High Efficiency Particulate Air (HEPA) filters that require frequent removal, replacement, and disposal. The need for routine replacements is often caused by accelerated filter loading due to the moist operating environment, which structurally weakens the filter media. This is not only costly, but subjects site personnel to radiation exposure and possible contamination. The types of filter media tested, as part of a National Energy Technology Laboratory procurement, were sintered metal and monolith ceramic. The media were subjected to a hostile environment to simulate conditions that challenge the tank ventilation systems. The environment promoted rapid filter plugging to maximize the number of filter loading/cleaning cycles that would occur in a specified period of time. The filters were challenged using non-radioactive, simulated high level waste materials and atmospheric dust, as these materials are most responsible for filter pluggage in the field. The filters were cleaned/regenerated in situ using an aqueous solution of dilute (10% volume) nitric acid. The study found that both filter media were insensitive to high humidity or moisture conditions and were easily cleaned in situ. The filters regenerated to approximately clean filter status even after numerous plugging and cleaning cycles. The filters were leak tested using poly alpha olefin aerosol at the beginning, middle, and end of the

  17. High pressure-sensitive gene expression in Lactobacillus sanfranciscensis

    Directory of Open Access Journals (Sweden)

    R.F. Vogel

    2005-08-01

    Full Text Available Lactobacillus sanfranciscensis is a Gram-positive lactic acid bacterium used in food biotechnology. It is necessary to investigate many aspects of a model organism to elucidate mechanisms of stress response, to facilitate preparation, application and performance in food fermentation, to understand mechanisms of inactivation, and to identify novel tools for high pressure biotechnology. To investigate the mechanisms of the complex bacterial response to high pressure we have analyzed changes in the proteome and transcriptome by 2-D electrophoresis, and by microarrays and real time PCR, respectively. More than 16 proteins were found to be differentially expressed upon high pressure stress and were compared to those sensitive to other stresses. Except for one apparently high pressure-specific stress protein, no pressure-specific stress proteins were found, and the proteome response to pressure was found to differ from that induced by other stresses. Selected pressure-sensitive proteins were partially sequenced and their genes were identified by reverse genetics. In a transcriptome analysis of a redundancy cleared shot gun library, about 7% of the genes investigated were found to be affected. Most of them appeared to be up-regulated 2- to 4-fold and these results were confirmed by real time PCR. Gene induction was shown for some genes up-regulated at the proteome level (clpL/groEL/rbsK, while the response of others to high hydrostatic pressure at the transcriptome level seemed to differ from that observed at the proteome level. The up-regulation of selected genes supports the view that the cell tries to compensate for pressure-induced impairment of translation and membrane transport.

  18. Plasma Jet Printing and in Situ Reduction of Highly Acidic Graphene Oxide.

    Science.gov (United States)

    Dey, Avishek; Krishnamurthy, Satheesh; Bowen, James; Nordlund, Dennis; Meyyappan, M; Gandhiraman, Ram P

    2018-05-23

    Miniaturization of electronic devices and the advancement of Internet of Things pose exciting challenges to develop technologies for patterned deposition of functional nanomaterials. Printed and flexible electronic devices and energy storage devices can be embedded onto clothing or other flexible surfaces. Graphene oxide (GO) has gained much attention in printed electronics due its solution processability, robustness, and high electrical conductivity in the reduced state. Here, we introduce an approach to print GO films from highly acidic suspensions with in situ reduction using an atmospheric pressure plasma jet. Low-temperature plasma of a He and H 2 mixture was used successfully to reduce a highly acidic GO suspension (pH < 2) in situ during deposition. This technique overcomes the multiple intermediate steps required to increase the conductivity of deposited GO. X-ray spectroscopic studies confirmed that the reaction intermediates and the concentration of oxygen functionalities bonded to GO have been reduced significantly by this approach without any additional steps. Moreover, the reduced GO films showed enhanced conductivity. Hence, this technique has a strong potential for printing conducting patterns of GO for a range of large-scale applications.

  19. Toward biotechnology in space: High-throughput instruments for in situ biological research beyond Earth.

    Science.gov (United States)

    Karouia, Fathi; Peyvan, Kianoosh; Pohorille, Andrew

    2017-11-15

    Space biotechnology is a nascent field aimed at applying tools of modern biology to advance our goals in space exploration. These advances rely on our ability to exploit in situ high throughput techniques for amplification and sequencing DNA, and measuring levels of RNA transcripts, proteins and metabolites in a cell. These techniques, collectively known as "omics" techniques have already revolutionized terrestrial biology. A number of on-going efforts are aimed at developing instruments to carry out "omics" research in space, in particular on board the International Space Station and small satellites. For space applications these instruments require substantial and creative reengineering that includes automation, miniaturization and ensuring that the device is resistant to conditions in space and works independently of the direction of the gravity vector. Different paths taken to meet these requirements for different "omics" instruments are the subjects of this review. The advantages and disadvantages of these instruments and technological solutions and their level of readiness for deployment in space are discussed. Considering that effects of space environments on terrestrial organisms appear to be global, it is argued that high throughput instruments are essential to advance (1) biomedical and physiological studies to control and reduce space-related stressors on living systems, (2) application of biology to life support and in situ resource utilization, (3) planetary protection, and (4) basic research about the limits on life in space. It is also argued that carrying out measurements in situ provides considerable advantages over the traditional space biology paradigm that relies on post-flight data analysis. Published by Elsevier Inc.

  20. Highly sensitive glucose sensor based on monodisperse palladium nickel/activated carbon nanocomposites.

    Science.gov (United States)

    Koskun, Yağmur; Şavk, Aysun; Şen, Betül; Şen, Fatih

    2018-06-20

    Glucose enzyme biosensors have been used for a variety of applications such as medical diagnosis, bioprocess engineering, beverage industry and environmental scanning etc. and there is still a growing interest in glucose sensors. For this purpose, addressed herein, as a novel glucose sensor, highly sensitive activated carbon (AC) decorated monodisperse nickel and palladium alloy nanocomposites modified glassy carbon electrode (Ni-Pd@AC/GCE NCs) have been synthesized by in-situ reduction technique. Raman Spectroscopy (RS), X-ray Photoelectron Spectroscopy (XPS), X-ray Diffraction (XRD), Transmission Electron Microscopy (TEM), cyclic voltammetry (CV) and chronoamperometry (CA) were used for the characterization of the prepared non-enzymatic glucose sensor. The characteristic sensor properties of the Ni-Pd@AC/GCE electrode were compared with Ni-Pd NCs/GCE, Ni@AC/GCE and Pd@AC/GCE and the results demonstrate that the AC is very effective in the enhancement of the electrocatalytic properties of sensor. In addition, the Ni-Pd@AC/GCE nanocomposites showed a very low detection limit of 0.014 μM, a wide linear range of 0.01 mM-1 mM and a very high sensitivity of 90 mA mM -1  cm -2 . Furthermore, the recommended sensor offer the various advantageous such as facile preparation, fast response time, high selectivity and sensitivity. Lastly, monodisperse Ni-Pd@AC/GCE was utilized to detect glucose in real sample species. Copyright © 2018 Elsevier B.V. All rights reserved.

  1. Molecular structure and thermodynamic predictions to create highly sensitive microRNA biosensors

    International Nuclear Information System (INIS)

    Larkey, Nicholas E.; Brucks, Corinne N.; Lansing, Shan S.; Le, Sophia D.; Smith, Natasha M.; Tran, Victoria; Zhang, Lulu; Burrows, Sean M.

    2016-01-01

    Many studies have established microRNAs (miRNAs) as post-transcriptional regulators in a variety of intracellular molecular processes. Abnormal changes in miRNA have been associated with several diseases. However, these changes are sometimes subtle and occur at nanomolar levels or lower. Several biosensing hurdles for in situ cellular/tissue analysis of miRNA limit detection of small amounts of miRNA. Of these limitations the most challenging are selectivity and sensor degradation creating high background signals and false signals. Recently we developed a reporter+probe biosensor for let-7a that showed potential to mitigate false signal from sensor degradation. Here we designed reporter+probe biosensors for miR-26a-2-3p and miR-27a-5p to better understand the effect of thermodynamics and molecular structures of the biosensor constituents on the analytical performance. Signal changes from interactions between Cy3 and Cy5 on the reporters were used to understand structural aspects of the reporter designs. Theoretical thermodynamic values, single stranded conformations, hetero- and homodimerization structures, and equilibrium concentrations of the reporters and probes were used to interpret the experimental observations. Studies of the sensitivity and selectivity revealed 5–9 nM detection limits in the presence and absence of interfering off-analyte miRNAs. These studies will aid in determining how to rationally design reporter+probe biosensors to overcome hurdles associated with highly sensitive miRNA biosensing. - Highlights: • Challenges facing highly sensitive miRNA biosensor designs are addressed. • Thermodynamic and molecular structure design metrics for reporter+probe biosensors are proposed. • The influence of ideal and non-ideal reporter hairpin structures on reporter+probe formation and signal change are discussed. • 5–9 nM limits of detection were observed with no interference from off-analytes.

  2. Molecular structure and thermodynamic predictions to create highly sensitive microRNA biosensors

    Energy Technology Data Exchange (ETDEWEB)

    Larkey, Nicholas E.; Brucks, Corinne N.; Lansing, Shan S.; Le, Sophia D.; Smith, Natasha M.; Tran, Victoria; Zhang, Lulu; Burrows, Sean M., E-mail: sean.burrows@oregonstate.edu

    2016-02-25

    Many studies have established microRNAs (miRNAs) as post-transcriptional regulators in a variety of intracellular molecular processes. Abnormal changes in miRNA have been associated with several diseases. However, these changes are sometimes subtle and occur at nanomolar levels or lower. Several biosensing hurdles for in situ cellular/tissue analysis of miRNA limit detection of small amounts of miRNA. Of these limitations the most challenging are selectivity and sensor degradation creating high background signals and false signals. Recently we developed a reporter+probe biosensor for let-7a that showed potential to mitigate false signal from sensor degradation. Here we designed reporter+probe biosensors for miR-26a-2-3p and miR-27a-5p to better understand the effect of thermodynamics and molecular structures of the biosensor constituents on the analytical performance. Signal changes from interactions between Cy3 and Cy5 on the reporters were used to understand structural aspects of the reporter designs. Theoretical thermodynamic values, single stranded conformations, hetero- and homodimerization structures, and equilibrium concentrations of the reporters and probes were used to interpret the experimental observations. Studies of the sensitivity and selectivity revealed 5–9 nM detection limits in the presence and absence of interfering off-analyte miRNAs. These studies will aid in determining how to rationally design reporter+probe biosensors to overcome hurdles associated with highly sensitive miRNA biosensing. - Highlights: • Challenges facing highly sensitive miRNA biosensor designs are addressed. • Thermodynamic and molecular structure design metrics for reporter+probe biosensors are proposed. • The influence of ideal and non-ideal reporter hairpin structures on reporter+probe formation and signal change are discussed. • 5–9 nM limits of detection were observed with no interference from off-analytes.

  3. Highly efficient and stable dye-sensitized solar cells based on nanographite/polypyrrole counter electrode

    International Nuclear Information System (INIS)

    Yue, Gentian; Zhang, Xin’an; Wang, Lei; Tan, Furui; Wu, Jihuai; Jiang, Qiwei; Lin, Jianming; Huang, Miaoliang; Lan, Zhang

    2014-01-01

    Graphical abstract: Much higher photovoltaic performance of dye-sensitized solar cell with nanographite/PPy counter electrode as well as that of Pt configuration device. - Highlights: • Pt-free dye-sensitized solar cells. • The nanographite/PPy composite film showed high catalytic activity as well as Pt electrode. • The enhanced catalytic activity was attributed to increased active sites. • The DSSC based on the nanographite/PPy electrode showed a high photovoltaic performance. - Abstract: Nanographite/polypyrrole (NG/PPy) composite film was successfully prepared via in situ polymerization on rigid fluorine-doped tin oxide substrate and served as counter electrode (CE) for dye-sensitized solar cells (DSSCs). The surface morphology and composition of the composite film were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Raman spectra and Fourier transform infrared spectroscopy (FTIR). The electrochemical performance of the NG/PPy electrode was evaluated by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The results of CV and EIS revealed that the NG/PPy electrode possessed excellent electrocatalytic activity for the reduction reaction of triiodide to iodide and low charge transfer resistance at the interface between electrolyte and CE, respectively. The DSSC assembled with the novel NG/PPy CE exhibited an enhanced power conversion efficiency of 7.40% under full sunlight illumination as comparing to that of the DSSC based on sputtered-Pt electrode. Thus, the NG/PPy CE could be premeditated as a promising alternative CE for low-cost and high- efficient DSSCs

  4. A simple, tunable, and highly sensitive radio-frequency sensor.

    Science.gov (United States)

    Cui, Yan; Sun, Jiwei; He, Yuxi; Wang, Zheng; Wang, Pingshan

    2013-08-05

    We report a radio frequency (RF) sensor that exploits tunable attenuators and phase shifters to achieve high-sensitivity and broad band frequency tunability. Three frequency bands are combined to enable sensor operations from ∼20 MHz to ∼38 GHz. The effective quality factor ( Q eff ) of the sensor is as high as ∼3.8 × 10 6 with 200  μ l of water samples. We also demonstrate the measurement of 2-proponal-water-solution permittivity at 0.01 mole concentration level from ∼1 GHz to ∼10 GHz. Methanol-water solution and de-ionized water are used to calibrate the RF sensor for the quantitative measurements.

  5. Correcting systematic errors in high-sensitivity deuteron polarization measurements

    Science.gov (United States)

    Brantjes, N. P. M.; Dzordzhadze, V.; Gebel, R.; Gonnella, F.; Gray, F. E.; van der Hoek, D. J.; Imig, A.; Kruithof, W. L.; Lazarus, D. M.; Lehrach, A.; Lorentz, B.; Messi, R.; Moricciani, D.; Morse, W. M.; Noid, G. A.; Onderwater, C. J. G.; Özben, C. S.; Prasuhn, D.; Levi Sandri, P.; Semertzidis, Y. K.; da Silva e Silva, M.; Stephenson, E. J.; Stockhorst, H.; Venanzoni, G.; Versolato, O. O.

    2012-02-01

    This paper reports deuteron vector and tensor beam polarization measurements taken to investigate the systematic variations due to geometric beam misalignments and high data rates. The experiments used the In-Beam Polarimeter at the KVI-Groningen and the EDDA detector at the Cooler Synchrotron COSY at Jülich. By measuring with very high statistical precision, the contributions that are second-order in the systematic errors become apparent. By calibrating the sensitivity of the polarimeter to such errors, it becomes possible to obtain information from the raw count rate values on the size of the errors and to use this information to correct the polarization measurements. During the experiment, it was possible to demonstrate that corrections were satisfactory at the level of 10 -5 for deliberately large errors. This may facilitate the real time observation of vector polarization changes smaller than 10 -6 in a search for an electric dipole moment using a storage ring.

  6. Correcting systematic errors in high-sensitivity deuteron polarization measurements

    Energy Technology Data Exchange (ETDEWEB)

    Brantjes, N.P.M. [Kernfysisch Versneller Instituut, University of Groningen, NL-9747AA Groningen (Netherlands); Dzordzhadze, V. [Brookhaven National Laboratory, Upton, NY 11973 (United States); Gebel, R. [Institut fuer Kernphysik, Juelich Center for Hadron Physics, Forschungszentrum Juelich, D-52425 Juelich (Germany); Gonnella, F. [Physica Department of ' Tor Vergata' University, Rome (Italy); INFN-Sez. ' Roma tor Vergata,' Rome (Italy); Gray, F.E. [Regis University, Denver, CO 80221 (United States); Hoek, D.J. van der [Kernfysisch Versneller Instituut, University of Groningen, NL-9747AA Groningen (Netherlands); Imig, A. [Brookhaven National Laboratory, Upton, NY 11973 (United States); Kruithof, W.L. [Kernfysisch Versneller Instituut, University of Groningen, NL-9747AA Groningen (Netherlands); Lazarus, D.M. [Brookhaven National Laboratory, Upton, NY 11973 (United States); Lehrach, A.; Lorentz, B. [Institut fuer Kernphysik, Juelich Center for Hadron Physics, Forschungszentrum Juelich, D-52425 Juelich (Germany); Messi, R. [Physica Department of ' Tor Vergata' University, Rome (Italy); INFN-Sez. ' Roma tor Vergata,' Rome (Italy); Moricciani, D. [INFN-Sez. ' Roma tor Vergata,' Rome (Italy); Morse, W.M. [Brookhaven National Laboratory, Upton, NY 11973 (United States); Noid, G.A. [Indiana University Cyclotron Facility, Bloomington, IN 47408 (United States); and others

    2012-02-01

    This paper reports deuteron vector and tensor beam polarization measurements taken to investigate the systematic variations due to geometric beam misalignments and high data rates. The experiments used the In-Beam Polarimeter at the KVI-Groningen and the EDDA detector at the Cooler Synchrotron COSY at Juelich. By measuring with very high statistical precision, the contributions that are second-order in the systematic errors become apparent. By calibrating the sensitivity of the polarimeter to such errors, it becomes possible to obtain information from the raw count rate values on the size of the errors and to use this information to correct the polarization measurements. During the experiment, it was possible to demonstrate that corrections were satisfactory at the level of 10{sup -5} for deliberately large errors. This may facilitate the real time observation of vector polarization changes smaller than 10{sup -6} in a search for an electric dipole moment using a storage ring.

  7. Wide bandwidth transimpedance amplifier for extremely high sensitivity continuous measurements.

    Science.gov (United States)

    Ferrari, Giorgio; Sampietro, Marco

    2007-09-01

    This article presents a wide bandwidth transimpedance amplifier based on the series of an integrator and a differentiator stage, having an additional feedback loop to discharge the standing current from the device under test (DUT) to ensure an unlimited measuring time opportunity when compared to switched discharge configurations while maintaining a large signal amplification over the full bandwidth. The amplifier shows a flat response from 0.6 Hz to 1.4 MHz, the capability to operate with leakage currents from the DUT as high as tens of nanoamperes, and rail-to-rail dynamic range for sinusoidal current signals independent of the DUT leakage current. Also available is a monitor output of the stationary current to track experimental slow drifts. The circuit is ideal for noise spectral and impedance measurements of nanodevices and biomolecules when in the presence of a physiological medium and in all cases where high sensitivity current measurements are requested such as in scanning probe microscopy systems.

  8. Design of a charge sensitive preamplifier on high resistivity silicon

    International Nuclear Information System (INIS)

    Radeka, V.; Rehak, P.; Rescia, S.; Gatti, E.; Longoni, A.; Sampietro, M.; Holl, P.; Strueder, L.; Kemmer, J.

    1987-01-01

    A low noise, fast charge sensitive preamplifier was designed on high resistivity, detector grade silicon. It is built at the surface of a fully depleted region of n-type silicon. This allows the preamplifier to be placed very close to a detector anode. The preamplifier uses the classical input cascode configuration with a capacitor and a high value resistor in the feedback loop. The output stage of the preamplifier can drive a load up to 20pF. The power dissipation of the preamplifier is 13mW. The amplifying elements are ''Single Sided Gate JFETs'' developed especially for this application. Preamplifiers connected to a low capacitance anode of a drift type detector should achieve a rise time of 20ns and have an equivalent noise charge (ENC), after a suitable shaping, of less than 50 electrons. This performance translates to a position resolution better than 3μm for silicon drift detectors. 6 refs., 9 figs

  9. Circulating and in situ lymphocyte subsets and Langerhans cells in patients with compositae oleoresin dermatitis and increased ultraviolet A sensitivity during treatment with azathioprine

    International Nuclear Information System (INIS)

    Baadsgaard, O.

    1986-01-01

    Circulating and in situ lymphocyte subsets and Langerhans cells in four patients with compositae oleoresin dermatitis and increased ultraviolet A sensitivity before and during treatment with azathioprine were estimated. It was found that the number of Leu 6+ Langerhans cells decreased during therapy. This decrease was accompanied by a reduction in the number of Leu 2a+, Leu 3a+, Leu 4+, DR+, and Leu M2+ cells in the blood and a reduction in the number of Leu 2a+, Leu 3a+, Leu 4+, and DR+ cells in the skin. Concomitantly with the changes in the number of immunocompetent cells, the eczema cleared

  10. Optical properties of highly n-doped germanium obtained by in situ doping and laser annealing

    International Nuclear Information System (INIS)

    Frigerio, J; Ballabio, A; Isella, G; Gallacher, K; Millar, R; Paul, D; Gilberti, V; Baldassarre, L; Ortolani, M; Milazzo, R; Napolitani, E; Maiolo, L; Minotti, A; Pecora, A; Bottegoni, F; Biagioni, P

    2017-01-01

    High n-type doping in germanium is essential for many electronic and optoelectronic applications especially for high performance Ohmic contacts, lasing and mid-infrared plasmonics. We report on the combination of in situ doping and excimer laser annealing to improve the activation of phosphorous in germanium. An activated n-doping concentration of 8.8  ×  10 19 cm −3 has been achieved starting from an incorporated phosphorous concentration of 1.1  ×  10 20 cm −3 . Infrared reflectivity data fitted with a multi-layer Drude model indicate good uniformity over a 350 nm thick layer. Photoluminescence demonstrates clear bandgap narrowing and an increased ratio of direct to indirect bandgap emission confirming the high doping densities achieved. (paper)

  11. Optical properties of highly n-doped germanium obtained by in situ doping and laser annealing

    Science.gov (United States)

    Frigerio, J.; Ballabio, A.; Gallacher, K.; Giliberti, V.; Baldassarre, L.; Millar, R.; Milazzo, R.; Maiolo, L.; Minotti, A.; Bottegoni, F.; Biagioni, P.; Paul, D.; Ortolani, M.; Pecora, A.; Napolitani, E.; Isella, G.

    2017-11-01

    High n-type doping in germanium is essential for many electronic and optoelectronic applications especially for high performance Ohmic contacts, lasing and mid-infrared plasmonics. We report on the combination of in situ doping and excimer laser annealing to improve the activation of phosphorous in germanium. An activated n-doping concentration of 8.8  ×  1019 cm-3 has been achieved starting from an incorporated phosphorous concentration of 1.1  ×  1020 cm-3. Infrared reflectivity data fitted with a multi-layer Drude model indicate good uniformity over a 350 nm thick layer. Photoluminescence demonstrates clear bandgap narrowing and an increased ratio of direct to indirect bandgap emission confirming the high doping densities achieved.

  12. High-Sensitivity Temperature-Independent Silicon Photonic Microfluidic Biosensors

    Science.gov (United States)

    Kim, Kangbaek

    Optical biosensors that can precisely quantify the presence of specific molecular species in real time without the need for labeling have seen increased use in the drug discovery industry and molecular biology in general. Of the many possible optical biosensors, the TM mode Si biosensor is shown to be very attractive in the sensing application because of large field amplitude on the surface and cost effective CMOS VLSI fabrication. Noise is the most fundamental factor that limits the performance of sensors in development of high-sensitivity biosensors, and noise reduction techniques require precise studies and analysis. One such example stems from thermal fluctuations. Generally SOI biosensors are vulnerable to ambient temperature fluctuations because of large thermo-optic coefficient of silicon (˜2x10 -4 RIU/K), typically requiring another reference ring and readout sequence to compensate temperature induced noise. To address this problem, we designed sensors with a novel TM-mode shallow-ridge waveguide that provides both large surface amplitude for bulk and surface sensing. With proper design, this also provides large optical confinement in the aqueous cladding that renders the device athermal using the negative thermo-optic coefficient of water (~ --1x10-4RIU/K), demonstrating cancellation of thermo-optic effects for aqueous solution operation near 300K. Additional limitations resulting from mechanical actuator fluctuations, stability of tunable lasers, and large 1/f noise of lasers and sensor electronics can limit biosensor performance. Here we also present a simple harmonic feedback readout technique that obviates the need for spectrometers and tunable lasers. This feedback technique reduces the impact of 1/f noise to enable high-sensitivity, and a DSP lock-in with 256 kHz sampling rate can provide down to micros time scale monitoring for fast transitions in biomolecular concentration with potential for small volume and low cost. In this dissertation, a novel

  13. High temporal resolution in situ measurement of the effective particle size characteristics of fluvial suspended sediment.

    Science.gov (United States)

    Williams, N D; Walling, D E; Leeks, G J L

    2007-03-01

    This paper reports the use of a LISST-100 device to monitor the effective particle size characteristics of suspended sediment in situ, and at a quasi-continuous temporal resolution. The study site was located on the River Exe at Thorverton, Devon, UK. This device has not previously been utilized in studies of fluvial suspended sediment at the storm event scale, and existing studies of suspended sediment dynamics have not involved such a high temporal resolution for extended periods. An evaluation of the field performance of the instrument is presented, with respect to innovative data collection and analysis techniques. It was found that trends in the effective particle size distribution (EPSD) and degree of flocculation of suspended sediment at the study site were highly complex, and showed significant short-term variability that has not previously been documented in the fluvial environment. The collection of detailed records of EPSD facilitated interpretation of the dynamic evolution of the size characteristics of suspended sediment, in relation to its likely source and delivery and flocculation mechanisms. The influence of measurement frequency is considered in terms of its implications for future studies of the particle size of fluvial suspended sediment employing in situ data acquisition.

  14. Method for local temperature measurement in a nanoreactor for in situ high-resolution electron microscopy.

    Science.gov (United States)

    Vendelbo, S B; Kooyman, P J; Creemer, J F; Morana, B; Mele, L; Dona, P; Nelissen, B J; Helveg, S

    2013-10-01

    In situ high-resolution transmission electron microscopy (TEM) of solids under reactive gas conditions can be facilitated by microelectromechanical system devices called nanoreactors. These nanoreactors are windowed cells containing nanoliter volumes of gas at ambient pressures and elevated temperatures. However, due to the high spatial confinement of the reaction environment, traditional methods for measuring process parameters, such as the local temperature, are difficult to apply. To address this issue, we devise an electron energy loss spectroscopy (EELS) method that probes the local temperature of the reaction volume under inspection by the electron beam. The local gas density, as measured using quantitative EELS, is combined with the inherent relation between gas density and temperature, as described by the ideal gas law, to obtain the local temperature. Using this method we determined the temperature gradient in a nanoreactor in situ, while the average, global temperature was monitored by a traditional measurement of the electrical resistivity of the heater. The local gas temperatures had a maximum of 56 °C deviation from the global heater values under the applied conditions. The local temperatures, obtained with the proposed method, are in good agreement with predictions from an analytical model. Copyright © 2013 Elsevier B.V. All rights reserved.

  15. High spatial resolution and high brightness ion beam probe for in-situ elemental and isotopic analysis

    Science.gov (United States)

    Long, Tao; Clement, Stephen W. J.; Bao, Zemin; Wang, Peizhi; Tian, Di; Liu, Dunyi

    2018-03-01

    A high spatial resolution and high brightness ion beam from a cold cathode duoplasmatron source and primary ion optics are presented and applied to in-situ analysis of micro-scale geological material with complex structural and chemical features. The magnetic field in the source as well as the influence of relative permeability of magnetic materials on source performance was simulated using COMSOL to confirm the magnetic field strength of the source. Based on SIMION simulation, a high brightness and high spatial resolution negative ion optical system has been developed to achieve Critical (Gaussian) illumination mode. The ion source and primary column are installed on a new Time-of-Flight secondary ion mass spectrometer for analysis of geological samples. The diameter of the ion beam was measured by the knife-edge method and a scanning electron microscope (SEM). Results show that an O2- beam of ca. 5 μm diameter with a beam intensity of ∼5 nA and an O- beam of ca. 5 μm diameter with a beam intensity of ∼50 nA were obtained, respectively. This design will open new possibilities for in-situ elemental and isotopic analysis in geological studies.

  16. High sensitivity pyrogen testing in water and dialysis solutions.

    Science.gov (United States)

    Daneshian, Mardas; Wendel, Albrecht; Hartung, Thomas; von Aulock, Sonja

    2008-07-20

    The dialysis patient is confronted with hundreds of litres of dialysis solution per week, which pass the natural protective barriers of the body and are brought into contact with the tissue directly in the case of peritoneal dialysis or indirectly in the case of renal dialysis (hemodialysis). The components can be tested for living specimens or dead pyrogenic (fever-inducing) contaminations. The former is usually detected by cultivation and the latter by the endotoxin-specific Limulus Amoebocyte Lysate Assay (LAL). However, the LAL assay does not reflect the response of the human immune system to the wide variety of possible pyrogenic contaminations in dialysis fluids. Furthermore, the test is limited in its sensitivity to detect extremely low concentrations of pyrogens, which in their sum result in chronic pathologies in dialysis patients. The In vitro Pyrogen Test (IPT) employs human whole blood to detect the spectrum of pyrogens to which humans respond by measuring the release of the endogenous fever mediator interleukin-1beta. Spike recovery checks exclude interference. The test has been validated in an international study for pyrogen detection in injectable solutions. In this study we adapted the IPT to the testing of dialysis solutions. Preincubation of 50 ml spiked samples with albumin-coated microspheres enhanced the sensitivity of the assay to detect contaminations down to 0.1 pg/ml LPS or 0.001 EU/ml in water or saline and allowed pyrogen detection in dialysis concentrates or final working solutions. This method offers high sensitivity detection of human-relevant pyrogens in dialysis solutions and components.

  17. In-situ high temperature XRD of calcium phosphate biomaterial using DEHPA as the starting material

    International Nuclear Information System (INIS)

    Meor Yusoff Meor Sulaiman; Masliana Muslim

    2009-01-01

    A process to produce calcium phosphate biomaterial was done using an organic based phosphoric acid (DEHPA) as its starting material. The gel obtained from this reaction was used to study calcium phosphate transformation using in-situ XRD with temperature ranges from room temperature to 1300 degree C. The results obtained from this analysis show the following phase transformation: Gel β-Ca 2 P 2 O 7 β-TCP + HA α-TCP + HA, β-Ca 2 P 2 O 7 forms at 400 degree C and as we heat the sample at 1000 degree C peaks belonging to β- TCP and HA appears showing the transformation of the β-Ca 2 P 2 O 7 phase. When the sample is heated up further to 1200 degree C, β-TCP is transform into α-TCP. In the cold in-situ study, XRD analysis was performed on the sample from room temperature to -140 degree C. At room the XRD diffractogram shows the sample as an amorphous material and as the temperature was further lowered sharp peaks begins to form indicating that the material had becomes crystalline. The peaks were identified to be that calcium hydrogen phosphate (Ca(H 2 PO 4 ) 2 ) and this indicates that there is no hydroxyl group removal during the cooling process. The relative crystallinity values obtained for the different cooling temperatures show a slow exponential increase on the initial cooling of 0 to -100 degree C and at further cooling temperatures resulted fast and linear process. Also unlike the in-situ XRD analysis performs at high temperature no phase transformation occurred at this low temperature. (Author)

  18. Highly sensitive detection of molecular interactions with plasmonic optical fiber grating sensors.

    Science.gov (United States)

    Voisin, Valérie; Pilate, Julie; Damman, Pascal; Mégret, Patrice; Caucheteur, Christophe

    2014-01-15

    Surface Plasmon resonance (SPR) optical fiber biosensors constitute a miniaturized counterpart to the bulky prism configuration and offer remote operation in very small volumes of analyte. They are a cost-effective and relatively straightforward technique to yield in situ (or even possibly in vivo) molecular detection. The biosensor configuration reported in this work uses nanometric-scale gold-coated tilted fiber Bragg gratings (TFBGs) interrogated by light polarized radially to the optical fiber outer surface, so as to maximize the optical coupling with the SPR. These gratings were recently associated to aptamers to assess their label-free biorecognition capability in buffer and serum solutions. In this work, using the well-acknowledged biotin-streptavidin pair as a benchmark, we go forward in the demonstration of their unique sensitivity. In addition to the monitoring of the self-assembled monolayer (SAM) in real time, we report an unprecedented limit of detection (LOD) as low as 2 pM. Finally, an immunosensing experiment is realized with human transferrin (dissociation constant Kd~10(-8) M(-1)). It allows to assess both the reversibility and the robustness of the SPR-TFBG biosensors and to confirm their high sensitivity. © 2013 Published by Elsevier B.V.

  19. In situ synthesis of Bi2S3 sensitized WO3 nanoplate arrays with less interfacial defects and enhanced photoelectrochemical performance

    Science.gov (United States)

    Liu, Canjun; Yang, Yahui; Li, Wenzhang; Li, Jie; Li, Yaomin; Chen, Qiyuan

    2016-03-01

    In this study, Bi2S3 sensitive layer has been grown on the surface of WO3 nanoplate arrays via an in situ approach. The characterization of samples were carried out using scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and ultraviolet-visible absorption spectroscopy (UV-vis). The results show that the Bi2S3 layer is uniformly formed on the surface of WO3 nanoplates and less interfacial defects were observed in the interface between the Bi2S3 and WO3. More importantly, the Bi2S3/WO3 films as photoanodes for photoelectrochemical (PEC) cells display the enhanced PEC performance compared with the Bi2S3/WO3 films prepared by a sequential ionic layer adsorption reaction (SILAR) method. In order to understand the reason for the enhanced PEC properties, the electron transport properties of the photoelectrodes were studied by using the transient photocurrent spectroscopy and intensity modulated photocurrent spectroscopy (IMPS). The Bi2S3/WO3 films prepared via an in situ approach have a greater transient time constant and higher electron transit rate. This is most likely due to less interfacial defects for the Bi2S3/WO3 films prepared via an in situ approach, resulting in a lower resistance and faster carrier transport in the interface between WO3 and Bi2S3.

  20. Luminescent Lanthanide Reporters for High-Sensitivity Novel Bioassays

    Energy Technology Data Exchange (ETDEWEB)

    Anstey, Mitchell R. [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Fruetel, Julia A. [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Foster, Michael E. [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Hayden, Carl C. [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Buckley, Heather L. [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Arnold, John [Sandia National Lab. (SNL-CA), Livermore, CA (United States)

    2013-09-01

    Biological imaging and assay technologies rely on fluorescent organic dyes as reporters for a number of interesting targets and processes. However, limitations of organic dyes such as small Stokes shifts, spectral overlap of emission signals with native biological fluorescence background, and photobleaching have all inhibited the development of highly sensitive assays. To overcome the limitations of organic dyes for bioassays, we propose to develop lanthanide-based luminescent dyes and demonstrate them for molecular reporting applications. This relatively new family of dyes was selected for their attractive spectral and chemical properties. Luminescence is imparted by the lanthanide atom and allows for relatively simple chemical structures that can be tailored to the application. The photophysical properties offer unique features such as narrow and non-overlapping emission bands, long luminescent lifetimes, and long wavelength emission, which enable significant sensitivity improvements over organic dyes through spectral and temporal gating of the luminescent signal.Growth in this field has been hindered due to the necessary advanced synthetic chemistry techniques and access to experts in biological assay development. Our strategy for the development of a new lanthanide-based fluorescent reporter system is based on chelation of the lanthanide metal center using absorbing chromophores. Our first strategy involves "Click" chemistry to develop 3-fold symmetric chelators and the other involves use of a new class of tetrapyrrole ligands called corroles. This two-pronged approach is geared towards the optimization of chromophores to enhance light output.

  1. New application of superconductors: High sensitivity cryogenic light detectors

    Energy Technology Data Exchange (ETDEWEB)

    Cardani, L., E-mail: laura.cardani@roma1.infn.it [Dipartimento di Fisica, Sapienza Università di Roma, Piazzale Aldo Moro 2, 00185 Roma (Italy); Physics Department, Princeton University, Washington Road, 08544 Princeton, NJ (United States); Bellini, F.; Casali, N. [Dipartimento di Fisica, Sapienza Università di Roma, Piazzale Aldo Moro 2, 00185 Roma (Italy); INFN – Sezione di Roma, Piazzale Aldo Moro 2, 00185 Roma, Italy (Italy); Castellano, M.G. [Istituto di Fotonica e Nanotecnologie – CNR, Via Cineto Romano 42, 00156 Roma (Italy); Colantoni, I.; Coppolecchia, A. [Dipartimento di Fisica, Sapienza Università di Roma, Piazzale Aldo Moro 2, 00185 Roma (Italy); Cosmelli, C.; Cruciani, A. [Dipartimento di Fisica, Sapienza Università di Roma, Piazzale Aldo Moro 2, 00185 Roma (Italy); INFN – Sezione di Roma, Piazzale Aldo Moro 2, 00185 Roma, Italy (Italy); D' Addabbo, A. [INFN – Laboratori Nazionali del Gran Sasso, Assergi (L' Aquila) 67010 (Italy); Di Domizio, S. [INFN – Sezione di Genova, Via Dodecaneso 33, 16146 Genova (Italy); Dipartimento di Fisica, Università degli Studi di Genova, Via Dodecaneso 33, 16146 Genova (Italy); Martinez, M. [Dipartimento di Fisica, Sapienza Università di Roma, Piazzale Aldo Moro 2, 00185 Roma (Italy); INFN – Sezione di Roma, Piazzale Aldo Moro 2, 00185 Roma, Italy (Italy); Laboratorio de Fisica Nuclear y Astroparticulas, Universidad de Zaragoza, Zaragoza 50009 (Spain); Tomei, C. [INFN – Sezione di Roma, Piazzale Aldo Moro 2, 00185 Roma, Italy (Italy); and others

    2017-02-11

    In this paper we describe the current status of the CALDER project, which is developing ultra-sensitive light detectors based on superconductors for cryogenic applications. When we apply an AC current to a superconductor, the Cooper pairs oscillate and acquire kinetic inductance, that can be measured by inserting the superconductor in a LC circuit with high merit factor. Interactions in the superconductor can break the Cooper pairs, causing sizable variations in the kinetic inductance and, thus, in the response of the LC circuit. The continuous monitoring of the amplitude and frequency modulation allows to reconstruct the incident energy with excellent sensitivity. This concept is at the basis of Kinetic Inductance Detectors (KIDs) that are characterized by natural aptitude to multiplexed read-out (several sensors can be tuned to different resonant frequencies and coupled to the same line), resolution of few eV, stable behavior over a wide temperature range, and ease in fabrication. We present the results obtained by the CALDER collaboration with 2×2 cm{sup 2} substrates sampled by 1 or 4 Aluminum KIDs. We show that the performances of the first prototypes are already competitive with those of other commonly used light detectors, and we discuss the strategies for a further improvement.

  2. New application of superconductors: High sensitivity cryogenic light detectors

    International Nuclear Information System (INIS)

    Cardani, L.; Bellini, F.; Casali, N.; Castellano, M.G.; Colantoni, I.; Coppolecchia, A.; Cosmelli, C.; Cruciani, A.; D'Addabbo, A.; Di Domizio, S.; Martinez, M.; Tomei, C.

    2017-01-01

    In this paper we describe the current status of the CALDER project, which is developing ultra-sensitive light detectors based on superconductors for cryogenic applications. When we apply an AC current to a superconductor, the Cooper pairs oscillate and acquire kinetic inductance, that can be measured by inserting the superconductor in a LC circuit with high merit factor. Interactions in the superconductor can break the Cooper pairs, causing sizable variations in the kinetic inductance and, thus, in the response of the LC circuit. The continuous monitoring of the amplitude and frequency modulation allows to reconstruct the incident energy with excellent sensitivity. This concept is at the basis of Kinetic Inductance Detectors (KIDs) that are characterized by natural aptitude to multiplexed read-out (several sensors can be tuned to different resonant frequencies and coupled to the same line), resolution of few eV, stable behavior over a wide temperature range, and ease in fabrication. We present the results obtained by the CALDER collaboration with 2×2 cm"2 substrates sampled by 1 or 4 Aluminum KIDs. We show that the performances of the first prototypes are already competitive with those of other commonly used light detectors, and we discuss the strategies for a further improvement.

  3. High-Sensitivity AGN Polarimetry at Sub-Millimeter Wavelengths

    Directory of Open Access Journals (Sweden)

    Ivan Martí-Vidal

    2017-10-01

    Full Text Available The innermost regions of radio loud Active Galactic Nuclei (AGN jets are heavily affected by synchrotron self-absorption, due to the strong magnetic fields and high particle densities in these extreme zones. The only way to overcome this absorption is to observe at sub-millimeter wavelengths, although polarimetric observations at such frequencies have so far been limited by sensitivity and calibration accuracy. However, new generation instruments such as the Atacama Large mm/sub-mm Array (ALMA overcome these limitations and are starting to deliver revolutionary results in the observational studies of AGN polarimetry. Here we present an overview of our state-of-the-art interferometric mm/sub-mm polarization observations of AGN jets with ALMA (in particular, the gravitationally-lensed sources PKS 1830−211 and B0218+359, which allow us to probe the magneto-ionic conditions at the regions closest to the central black holes.

  4. High resolution, position sensitive detector for energetic particle beams

    International Nuclear Information System (INIS)

    Marsh, E.P.; Strathman, M.D.; Reed, D.A.; Odom, R.W.; Morse, D.H.; Pontau, A.E.

    1993-01-01

    The performance and design of an imaging position sensitive, particle beam detector will be presented. The detector is minimally invasive, operates a wide dynamic range (>10 10 ), and exhibits high spatial resolution. The secondary electrons produced when a particle beam passes through a thin foil are imaged using stigmatic ion optics onto a two-dimensional imaging detector. Due to the low scattering cross section of the 6 nm carbon foil the detector is a minimal perturbation on the primary beam. A prototype detector with an image resolution of approximately 5 μm for a field of view of 1 mm has been reported. A higher resolution detector for imaging small beams (<50 μm) with an image resolution of better than 0.5 μm has since been developed and its design is presented. (orig.)

  5. High resolution, position sensitive detector for energetic particle beams

    Energy Technology Data Exchange (ETDEWEB)

    Marsh, E P [Charles Evans and Associates, Redwood City, CA (United States); Strathman, M D [Charles Evans and Associates, Redwood City, CA (United States); Reed, D A [Charles Evans and Associates, Redwood City, CA (United States); Odom, R W [Charles Evans and Associates, Redwood City, CA (United States); Morse, D H [Sandia National Labs., Livermore, CA (United States); Pontau, A E [Sandia National Labs., Livermore, CA (United States)

    1993-05-01

    The performance and design of an imaging position sensitive, particle beam detector will be presented. The detector is minimally invasive, operates a wide dynamic range (>10[sup 10]), and exhibits high spatial resolution. The secondary electrons produced when a particle beam passes through a thin foil are imaged using stigmatic ion optics onto a two-dimensional imaging detector. Due to the low scattering cross section of the 6 nm carbon foil the detector is a minimal perturbation on the primary beam. A prototype detector with an image resolution of approximately 5 [mu]m for a field of view of 1 mm has been reported. A higher resolution detector for imaging small beams (<50 [mu]m) with an image resolution of better than 0.5 [mu]m has since been developed and its design is presented. (orig.)

  6. Highly Sensitive Filter Paper Substrate for SERS Trace Explosives Detection

    Directory of Open Access Journals (Sweden)

    Pedro M. Fierro-Mercado

    2012-01-01

    Full Text Available We report on a novel and extremely low-cost surface-enhanced Raman spectroscopy (SERS substrate fabricated depositing gold nanoparticles on common lab filter paper using thermal inkjet technology. The paper-based substrate combines all advantages of other plasmonic structures fabricated by more elaborate techniques with the dynamic flexibility given by the inherent nature of the paper for an efficient sample collection, robustness, and stability. We describe the fabrication, characterization, and SERS activity of our substrate using 2,4,6-trinitrotoluene, 2,4-dinitrotoluene, and 1,3,5-trinitrobenzene as analytes. The paper-based SERS substrates presented a high sensitivity and excellent reproducibility for analytes employed, demonstrating a direct application in forensic science and homeland security.

  7. High efficiency solid-state sensitized heterojunction photovoltaic device

    KAUST Repository

    Wang, Mingkui

    2010-06-01

    The high molar extinction coefficient heteroleptic ruthenium dye, NaRu(4,4′-bis(5-(hexylthio)thiophen-2-yl)-2,2′-bipyridine) (4-carboxylic acid-4′-carboxylate-2,2′-bipyridine) (NCS) 2, exhibits certified 5% electric power conversion efficiency at AM 1.5 solar irradiation (100 mW cm-2) in a solid-state dye-sensitized solar cell using 2,2′,7,7′-tetrakis-(N,N-di-pmethoxyphenylamine)-9, 9′-spirobifluorene (spiro-MeOTAD) as the organic hole-transporting material. This demonstration elucidates a class of photovoltaic devices with potential for low-cost power generation. © 2010 Elsevier Ltd. All rights reserved.

  8. High efficiency solid-state sensitized heterojunction photovoltaic device

    KAUST Repository

    Wang, Mingkui; Liu, Jingyuan; Cevey-Ha, Ngoc-Le; Moon, Soo-Jin; Liska, Paul; Humphry-Baker, Robin; Moser, Jacques-E.; Grä tzel, Carole; Wang, Peng; Zakeeruddin, Shaik M.

    2010-01-01

    The high molar extinction coefficient heteroleptic ruthenium dye, NaRu(4,4′-bis(5-(hexylthio)thiophen-2-yl)-2,2′-bipyridine) (4-carboxylic acid-4′-carboxylate-2,2′-bipyridine) (NCS) 2, exhibits certified 5% electric power conversion efficiency at AM 1.5 solar irradiation (100 mW cm-2) in a solid-state dye-sensitized solar cell using 2,2′,7,7′-tetrakis-(N,N-di-pmethoxyphenylamine)-9, 9′-spirobifluorene (spiro-MeOTAD) as the organic hole-transporting material. This demonstration elucidates a class of photovoltaic devices with potential for low-cost power generation. © 2010 Elsevier Ltd. All rights reserved.

  9. Qualification, commissioning and in situ monitoring of high heat flux plasma facing components

    Energy Technology Data Exchange (ETDEWEB)

    Escourbiac, F. [Association Euratom-CEA, CEA/DSM/DRFC, CEA/Cadarache, F-13108 Saint Paul Lez Durance (France)], E-mail: frederic.escourbiac@cea.fr; Durocher, A.; Grosman, A.; Cismondi, F.; Courtois, X.; Farjon, J.L.; Schlosser, J. [Association Euratom-CEA, CEA/DSM/DRFC, CEA/Cadarache, F-13108 Saint Paul Lez Durance (France); Merola, M.; Tivey, R. [ITER Team, CEA/Cadarache, F-13108 Saint Paul Lez Durance (France)

    2007-10-15

    Up-to-date development of actively cooled high heat flux (HHF) plasma facing components (PFC) prototypes only allows reduced margins with regards to the ITER thermal requirements. Additionally, perfect quality cannot be ensured along series manufacturing: the presence of flaws which impair the heat transfer capability of the component, in particular at the interface armour/heat sink appears to be statistically unavoidable. In order to ensure a successful series production, a qualification methodology of actively cooled high heat flux plasma facing components is proposed. Secondly, advanced non-destructive techniques developed for HHF PFC commissioning are detailed with definition of acceptance criteria. Finally, innovative diagnostics for in situ monitoring during plasma operations or tokamak shutdowns are investigated in order to prevent immediate damage (safety monitoring); or evaluate component degradation (health monitoring). This work takes into account the relevance to Tore Supra, and is applied to W7X and ITER Divertor HHF PFC.

  10. Qualification, commissioning and in situ monitoring of high heat flux plasma facing components

    International Nuclear Information System (INIS)

    Escourbiac, F.; Durocher, A.; Grosman, A.; Cismondi, F.; Courtois, X.; Farjon, J.L.; Schlosser, J.; Merola, M.; Tivey, R.

    2007-01-01

    Up-to-date development of actively cooled high heat flux (HHF) plasma facing components (PFC) prototypes only allows reduced margins with regards to the ITER thermal requirements. Additionally, perfect quality cannot be ensured along series manufacturing: the presence of flaws which impair the heat transfer capability of the component, in particular at the interface armour/heat sink appears to be statistically unavoidable. In order to ensure a successful series production, a qualification methodology of actively cooled high heat flux plasma facing components is proposed. Secondly, advanced non-destructive techniques developed for HHF PFC commissioning are detailed with definition of acceptance criteria. Finally, innovative diagnostics for in situ monitoring during plasma operations or tokamak shutdowns are investigated in order to prevent immediate damage (safety monitoring); or evaluate component degradation (health monitoring). This work takes into account the relevance to Tore Supra, and is applied to W7X and ITER Divertor HHF PFC

  11. In Situ High Resolution Synchrotron X-Ray Powder Diffraction Studies of Lithium Batteries

    DEFF Research Database (Denmark)

    Amri, Mahrez; Fitch, Andy; Norby, Poul

    2015-01-01

    allowing diffraction information to be obtained from only the active material during battery operation [2]. High resolution synchrotron x-ray powder diffraction technique has been undertaken to obtain detailed structural and compositional information during lithiation/delithiation of commercial LiFePO4...... materials [3]. We report results from the first in situ time resolved high resolution powder diffraction experiments at beamline ID22/31 at the European Synchrotron Radiation Facility, ESRF. We follow the structural changes during charge of commercial LiFePO4 based battery materials using the Rietveld...... method. Conscientious Rietveld analysis shows slight but continuous deviation of lattice parameters from those of the fully stoichiometric end members LiFePO4 and FePO4 indicating a subsequent variation of stoichiometry during cathode delithiation. The application of an intermittent current pulses during...

  12. Effective dose calculation in CT using high sensitivity TLDs

    International Nuclear Information System (INIS)

    Brady, Z.; Johnston, P.N.

    2010-01-01

    Full text: To determine the effective dose for common paediatric CT examinations using thermoluminescence dosimetry (TLD) mea surements. High sensitivity TLD chips (LiF:Mg,Cu,P, TLD-IOOH, Thermo Fisher Scientific, Waltham, MA) were calibrated on a linac at an energy of 6 MY. A calibration was also performed on a superricial X-ray unit at a kilovoltage energy to validate the megavoltage cali bration for the purpose of measuring doses in the diagnostic energy range. The dose variation across large organs was assessed and a methodology for TLD placement in a 10 year old anthropomorphic phantom developed. Effective dose was calculated from the TLD measured absorbed doses for typical CT examinations after correcting for the TLD energy response and taking into account differences in the mass energy absorption coefficients for different tissues and organs. Results Using new tissue weighting factors recommended in ICRP Publication 103, the effective dose for a CT brain examination on a 10 year old was 1.6 millisieverts (mSv), 4.9 mSv for a CT chest exa ination and 4.7 mSv for a CT abdomen/pelvis examination. These values are lower for the CT brain examination, higher for the CT chest examination and approximately the same for the CT abdomen/ pelvis examination when compared with effective doses calculated using ICRP Publication 60 tissue weighting factors. Conclusions High sensitivity TLDs calibrated with a radiotherapy linac are useful for measuring dose in the diagnostic energy range and overcome limitations of output reproducibility and uniformity asso ciated with traditional TLD calibration on CT scanners or beam quality matched diagnostic X-ray units.

  13. In Situ Mapping of the Molecular Arrangement of Amphiphilic Dye Molecules at the TiO 2 Surface of Dye-Sensitized Solar Cells

    KAUST Repository

    Voïtchovsky, Kislon

    2015-05-27

    © 2015 American Chemical Society. Amphiphilic sensitizers are central to the function of dye-sensitized solar cells. It is known that the cell\\'s performance depends on the molecular arrangement and the density of the dye on the semiconductor surface, but a molecular-level picture of the cell-electrolyte interface is still lacking. Here, we present subnanometer in situ atomic force microscopy images of the Z907 dye at the surface of TiO2 in a relevant liquid. Our results reveal changes in the conformation and the lateral arrangement of the dye molecules, depending on their average packing density on the surface. Complementary quantitative measurements on the ensemble of the film are obtained by the quartz-crystal microbalance with dissipation technique. An atomistic picture of the dye coverage-dependent packing, the effectiveness of the hydrophobic alkyl chains as blocking layer, and the solvent accessibility is obtained from molecular dynamics simulations. (Figure Presented).

  14. Highly water-absorbing silk yarn with interpenetrating network via in situ polymerization.

    Science.gov (United States)

    Lee, Ka I; Wang, Xiaowen; Guo, Xia; Yung, Ka-Fu; Fei, Bin

    2017-02-01

    Silk was modified via in situ polymerization of two monomers acrylamide and sodium acrylate by swelling in an effective LiBr dissolution system. Swelling of natural silks in LiBr solutions of low concentration was clearly observed under optical microscope, and their conformational changes were revealed by X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy. Dissolution tests and FTIR spectra of these modified silks suggested the presence of interpenetrating network of polyacrylamide and poly(sodium acrylate) in the silk yarns. These modified silks exhibited superior water absorption to that of raw silk and greatly improved mechanical properties in both dry and wet states. These novel modified silks also showed low cytotoxicity towards skin keratinocytes, having potential applications in biomedical textiles. This modification method by in situ polymerization after swelling in LiBr provides a new route to highly enhance the properties and performance of silk for various applications. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. In situ ultrasonic examination of high-strength steam generator support bolts

    International Nuclear Information System (INIS)

    Jusino, A.

    1985-01-01

    Currently employed high-strength steam generator support bolting material (designed prior to ASME Section III Part NF or Component Supports), 38.1 mm in diameter, in combination with high preloads are susceptible to stress corrosion cracking because of the relatively low stress corrosion resistance (K/sub ISCC/) properties. These bolts are part of the pressurized water reactor steam generator supports at the integral support pads (three per steam generator, with each pad housing six, eight, or ten bolts depending on the design). The US Nuclear Regulatory Commission concerns for high-strength bolting were identified in NUREG-0577, ''Potential for Low Fracture Toughness and Laminar Tearing in PWR Steam Generator and Reactor Coolant Pump Supports,'' which was issued for comment on unresolved safety issue A-12. Subsequently, the bolting issues were addressed in generic issue B29. One of the issues deals specifically with high-strength bolting materials, which are vulnerable to stress corrosion cracking. A Westinghouse Owners Group funded program was established to develop in situ ultrasonic examination techniques to determine steam generator support bolting integrity at the head-to-shank and first-thread locations. This program was established in order to determine bolting integrity in place. Ultrasonic techniques were developed for both socket-head and flat-head bolt configurations. As a result of this program, in situ ultrasonic examination techniques were developed for examination of PWR steam generator support bolts. By employing these techniques utilities will be able to ensure the integrity of this in-place bolting without incurring the costs previously experienced during removal for surface examinations

  16. High-resolution fiber-optic microendoscopy for in situ cellular imaging.

    Science.gov (United States)

    Pierce, Mark; Yu, Dihua; Richards-Kortum, Rebecca

    2011-01-11

    Many biological and clinical studies require the longitudinal study and analysis of morphology and function with cellular level resolution. Traditionally, multiple experiments are run in parallel, with individual samples removed from the study at sequential time points for evaluation by light microscopy. Several intravital techniques have been developed, with confocal, multiphoton, and second harmonic microscopy all demonstrating their ability to be used for imaging in situ. With these systems, however, the required infrastructure is complex and expensive, involving scanning laser systems and complex light sources. Here we present a protocol for the design and assembly of a high-resolution microendoscope which can be built in a day using off-the-shelf components for under US$5,000. The platform offers flexibility in terms of image resolution, field-of-view, and operating wavelength, and we describe how these parameters can be easily modified to meet the specific needs of the end user. We and others have explored the use of the high-resolution microendoscope (HRME) in in vitro cell culture, in excised and living animal tissues, and in human tissues in vivo. Users have reported the use of several different fluorescent contrast agents, including proflavine, benzoporphyrin-derivative monoacid ring A (BPD-MA), and fluoroscein, all of which have received full, or investigational approval from the FDA for use in human subjects. High-resolution microendoscopy, in the form described here, may appeal to a wide range of researchers working in the basic and clinical sciences. The technique offers an effective and economical approach which complements traditional benchtop microscopy, by enabling the user to perform high-resolution, longitudinal imaging in situ.

  17. Scanning Auger microscopy for high lateral and depth elemental sensitivity

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, E., E-mail: eugenie.martinez@cea.fr [CEA, LETI, MINATEC Campus, 17 rue des Martyrs, 38054 Grenoble Cedex 9 (France); Yadav, P. [CEA, LETI, MINATEC Campus, 17 rue des Martyrs, 38054 Grenoble Cedex 9 (France); Bouttemy, M. [Institut Lavoisier de Versailles, 45 av. des Etats-Unis, 78035 Versailles Cedex (France); Renault, O.; Borowik, Ł.; Bertin, F. [CEA, LETI, MINATEC Campus, 17 rue des Martyrs, 38054 Grenoble Cedex 9 (France); Etcheberry, A. [Institut Lavoisier de Versailles, 45 av. des Etats-Unis, 78035 Versailles Cedex (France); Chabli, A. [CEA, LETI, MINATEC Campus, 17 rue des Martyrs, 38054 Grenoble Cedex 9 (France)

    2013-12-15

    Highlights: •SAM performances and limitations are illustrated on real practical cases such as the analysis of nanowires and nanodots. •High spatial elemental resolution is shown with the analysis of reference semiconducting Al{sub 0.7}Ga{sub 0.3}As/GaAs multilayers. •High in-depth elemental resolution is also illustrated. Auger depth profiling with low energy ion beams allows revealing ultra-thin layers (∼1 nm). •Analysis of cross-sectional samples is another effective approach to obtain in-depth elemental information. -- Abstract: Scanning Auger microscopy is currently gaining interest for investigating nanostructures or thin multilayers stacks developed for nanotechnologies. New generation Auger nanoprobes combine high lateral (∼10 nm), energy (0.1%) and depth (∼2 nm) resolutions thus offering the possibility to analyze the elemental composition as well as the chemical state, at the nanometre scale. We report here on the performances and limitations on practical examples from nanotechnology research. The spatial elemental sensitivity is illustrated with the analysis of Al{sub 0.7}Ga{sub 0.3}As/GaAs heterostructures, Si nanowires and SiC nanodots. Regarding the elemental in-depth composition, two effective approaches are presented: low energy depth profiling to reveal ultra-thin layers (∼1 nm) and analysis of cross-sectional samples.

  18. Sensitivity and specificity of in situ proximity ligation for protein interaction analysis in a model of steatohepatitis with Mallory-Denk bodies.

    Directory of Open Access Journals (Sweden)

    Bernhard Zatloukal

    Full Text Available The in situ proximity ligation assay (isPLA is an increasingly used technology for in situ detection of protein interactions, post-translational modifications, and spatial relationships of antigens in cells and tissues, in general. In order to test its performance we compared isPLA with immunofluorescence microscopy by analyzing protein interactions in cytoplasmic protein aggregates, so-called Mallory Denk bodies (MDBs. These structures represent protein inclusions in hepatocytes typically found in human steatohepatitis and they can be generated in mice by feeding of 3,5-diethoxy-carbonyl-1,4-dihydrocollidine (DDC. We investigated the colocalization of all three key MDB components, namely keratin 8 (K8, keratin 18 (K18, and p62 (sequestosome 1 by isPLA and immunofluorescence microscopy. Sensitivity and specificity of isPLA was assessed by using Krt8-/- and Krt18-/- mice as biological controls, along with a series of technical controls. isPLA signal visualization is a robust technology with excellent sensitivity and specificity. The biological relevance of signals generated critically depends on the performance of antibodies used, which requires careful testing of antibodies like in immunofluorescence microscopy. There is a clear advantage of isPLA in visualizing protein co-localization, particularly when antigens are present at markedly different concentrations. Furthermore, isPLA is superior to confocal microscopy with respect to spatial resolution of colocalizing antigens. Disadvantages compared to immunofluorescence are increased costs and longer duration of the laboratory protocol.

  19. Laser-engraved carbon nanotube paper for instilling high sensitivity, high stretchability, and high linearity in strain sensors

    KAUST Repository

    Xin, Yangyang

    2017-06-29

    There is an increasing demand for strain sensors with high sensitivity and high stretchability for new applications such as robotics or wearable electronics. However, for the available technologies, the sensitivity of the sensors varies widely. These sensors are also highly nonlinear, making reliable measurement challenging. Here we introduce a new family of sensors composed of a laser-engraved carbon nanotube paper embedded in an elastomer. A roll-to-roll pressing of these sensors activates a pre-defined fragmentation process, which results in a well-controlled, fragmented microstructure. Such sensors are reproducible and durable and can attain ultrahigh sensitivity and high stretchability (with a gauge factor of over 4.2 × 10(4) at 150% strain). Moreover, they can attain high linearity from 0% to 15% and from 22% to 150% strain. They are good candidates for stretchable electronic applications that require high sensitivity and linearity at large strains.

  20. Powder agglomeration study in RF silane plasmas by in situ polarization-sensitive laser light scattering and TEM measurements

    Energy Technology Data Exchange (ETDEWEB)

    Courteille, C; Hollenstein, C; Dorier, J L; Gay, P; Schwarzenbach, W; Howling, A A [Ecole Polytechnique Federale, Lausanne (Switzerland). Centre de Recherche en Physique des Plasma (CRPP); Bertran, E; Viera, G [Barcelona Univ., Dep. de de Fisica Aplicada I Electronica, Barcelona (Spain); Martins, R; Macarico, A [FCTUNL, Materials Science Dep., Monte de Caparica (Portugal)

    1966-03-01

    To determine self-consistently the time evolution of particle size and their number density in situ multi-angle polarization laser light scattering was used. Cross-polarization intensities (incident and scattered light intensities with opposite polarization) measured at 135{sup o} and ex-situ TEM analysis demonstrate the existence of non-spherical agglomerates during the early phase of agglomeration. Later in the particle time development both techniques reveal spherical particles again. The presence of strong cross-polarization intensities is accompanied by low frequency instabilities detected on the scattered light intensities and plasma emission. It is found that the particle radius and particle number density during the agglomeration phase can be well described by the Brownian Free Molecule Coagulation model. Application of this neutral particle coagulation model is justified by calculation of the particle charge whereby it is shown that particles of a few tens of nanometer can be considered as neutral under our experimental conditions. The measured particle dispersion can be well described by a Brownian Free Molecule Coagulation model including a log-normal particle size distribution. (author) 11 figs., 48 refs.

  1. Powder agglomeration study in RF silane plasmas by in situ polarization-sensitive laser light scattering and TEM measurements

    International Nuclear Information System (INIS)

    Courteille, C.; Hollenstein, C.; Dorier, J.L.; Gay, P.; Schwarzenbach, W.; Howling, A.A.; Bertran, E.; Viera, G.; Martins, R.; Macarico, A.

    1966-03-01

    To determine self-consistently the time evolution of particle size and their number density in situ multi-angle polarization laser light scattering was used. Cross-polarization intensities (incident and scattered light intensities with opposite polarization) measured at 135 o and ex-situ TEM analysis demonstrate the existence of non-spherical agglomerates during the early phase of agglomeration. Later in the particle time development both techniques reveal spherical particles again. The presence of strong cross-polarization intensities is accompanied by low frequency instabilities detected on the scattered light intensities and plasma emission. It is found that the particle radius and particle number density during the agglomeration phase can be well described by the Brownian Free Molecule Coagulation model. Application of this neutral particle coagulation model is justified by calculation of the particle charge whereby it is shown that particles of a few tens of nanometer can be considered as neutral under our experimental conditions. The measured particle dispersion can be well described by a Brownian Free Molecule Coagulation model including a log-normal particle size distribution. (author) 11 figs., 48 refs

  2. Sensitive, selective nanoantenna-based biosensor platform for compact, in-situ exo-life detection and astronaut life support

    Data.gov (United States)

    National Aeronautics and Space Administration — We aim to develop a new nanotechnology-enabled sensing platform exceeding the sensitivity and selectivity of the current state-of-art (SOA) in portable, low-mass,...

  3. Accelerated Sensitivity Analysis in High-Dimensional Stochastic Reaction Networks.

    Science.gov (United States)

    Arampatzis, Georgios; Katsoulakis, Markos A; Pantazis, Yannis

    2015-01-01

    Existing sensitivity analysis approaches are not able to handle efficiently stochastic reaction networks with a large number of parameters and species, which are typical in the modeling and simulation of complex biochemical phenomena. In this paper, a two-step strategy for parametric sensitivity analysis for such systems is proposed, exploiting advantages and synergies between two recently proposed sensitivity analysis methodologies for stochastic dynamics. The first method performs sensitivity analysis of the stochastic dynamics by means of the Fisher Information Matrix on the underlying distribution of the trajectories; the second method is a reduced-variance, finite-difference, gradient-type sensitivity approach relying on stochastic coupling techniques for variance reduction. Here we demonstrate that these two methods can be combined and deployed together by means of a new sensitivity bound which incorporates the variance of the quantity of interest as well as the Fisher Information Matrix estimated from the first method. The first step of the proposed strategy labels sensitivities using the bound and screens out the insensitive parameters in a controlled manner. In the second step of the proposed strategy, a finite-difference method is applied only for the sensitivity estimation of the (potentially) sensitive parameters that have not been screened out in the first step. Results on an epidermal growth factor network with fifty parameters and on a protein homeostasis with eighty parameters demonstrate that the proposed strategy is able to quickly discover and discard the insensitive parameters and in the remaining potentially sensitive parameters it accurately estimates the sensitivities. The new sensitivity strategy can be several times faster than current state-of-the-art approaches that test all parameters, especially in "sloppy" systems. In particular, the computational acceleration is quantified by the ratio between the total number of parameters over the

  4. Accelerated Sensitivity Analysis in High-Dimensional Stochastic Reaction Networks.

    Directory of Open Access Journals (Sweden)

    Georgios Arampatzis

    Full Text Available Existing sensitivity analysis approaches are not able to handle efficiently stochastic reaction networks with a large number of parameters and species, which are typical in the modeling and simulation of complex biochemical phenomena. In this paper, a two-step strategy for parametric sensitivity analysis for such systems is proposed, exploiting advantages and synergies between two recently proposed sensitivity analysis methodologies for stochastic dynamics. The first method performs sensitivity analysis of the stochastic dynamics by means of the Fisher Information Matrix on the underlying distribution of the trajectories; the second method is a reduced-variance, finite-difference, gradient-type sensitivity approach relying on stochastic coupling techniques for variance reduction. Here we demonstrate that these two methods can be combined and deployed together by means of a new sensitivity bound which incorporates the variance of the quantity of interest as well as the Fisher Information Matrix estimated from the first method. The first step of the proposed strategy labels sensitivities using the bound and screens out the insensitive parameters in a controlled manner. In the second step of the proposed strategy, a finite-difference method is applied only for the sensitivity estimation of the (potentially sensitive parameters that have not been screened out in the first step. Results on an epidermal growth factor network with fifty parameters and on a protein homeostasis with eighty parameters demonstrate that the proposed strategy is able to quickly discover and discard the insensitive parameters and in the remaining potentially sensitive parameters it accurately estimates the sensitivities. The new sensitivity strategy can be several times faster than current state-of-the-art approaches that test all parameters, especially in "sloppy" systems. In particular, the computational acceleration is quantified by the ratio between the total number of

  5. High-gravity combustion synthesis and in situ melt infiltration: A new method for preparing cemented carbides

    International Nuclear Information System (INIS)

    Liu, Guanghua; Li, Jiangtao; Yang, Zengchao; Guo, Shibin; Chen, Yixiang

    2013-01-01

    A new method of high-gravity combustion synthesis and in situ melt infiltration is reported for preparing cemented carbides, where hot nickel melt is in situ synthesized from a highly exothermic combustion reaction and then infiltrated into tungsten carbide powder compacts. The as-prepared sample showed a homogeneous microstructure, and its relative density, hardness and flexural strength were 94.4%, 84 HRA and 1.49 GPa, respectively. Compared with conventional powder metallurgy approaches, high-gravity combustion synthesis offers a fast and furnace-free way to produce cemented carbides

  6. Final Report on Developing Microstructure-Property Correlation in Reactor Materials using in situ High-Energy X-rays

    Energy Technology Data Exchange (ETDEWEB)

    Li, Meimei [Argonne National Lab. (ANL), Argonne, IL (United States); Almer, Jonathan D. [Argonne National Lab. (ANL), Argonne, IL (United States); Yang, Yong [Univ. of Florida, Gainesville, FL (United States); Tan, Lizhen [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-01-01

    This report provides a summary of research activities on understanding microstructure – property correlation in reactor materials using in situ high-energy X-rays. The report is a Level 2 deliverable in FY16 (M2CA-13-IL-AN_-0403-0111), under the Work Package CA-13-IL-AN_- 0403-01, “Microstructure-Property Correlation in Reactor Materials using in situ High Energy Xrays”, as part of the DOE-NE NEET Program. The objective of this project is to demonstrate the application of in situ high energy X-ray measurements of nuclear reactor materials under thermal-mechanical loading, to understand their microstructure-property relationships. The gained knowledge is expected to enable accurate predictions of mechanical performance of these materials subjected to extreme environments, and to further facilitate development of advanced reactor materials. The report provides detailed description of the in situ X-ray Radiated Materials (iRadMat) apparatus designed to interface with a servo-hydraulic load frame at beamline 1-ID at the Advanced Photon Source. This new capability allows in situ studies of radioactive specimens subject to thermal-mechanical loading using a suite of high-energy X-ray scattering and imaging techniques. We conducted several case studies using the iRadMat to obtain a better understanding of deformation and fracture mechanisms of irradiated materials. In situ X-ray measurements on neutron-irradiated pure metal and model alloy and several representative reactor materials, e.g. pure Fe, Fe-9Cr model alloy, 316 SS, HT-UPS, and duplex cast austenitic stainless steels (CASS) CF-8 were performed under tensile loading at temperatures of 20-400°C in vacuum. A combination of wide-angle X-ray scattering (WAXS), small-angle X-ray scattering (SAXS), and imaging techniques were utilized to interrogate microstructure at different length scales in real time while the specimen was subject to thermal-mechanical loading. In addition, in situ X-ray studies were

  7. In situ imaging and proteome profiling indicate andrographolide is a highly promiscuous compound

    Science.gov (United States)

    Li, Lin; Wijaya, Hadhi; Samanta, Sanjay; Lam, Yulin; Yao, Shao Q.

    2015-06-01

    Natural products represent an enormous source of pharmacologically useful compounds, and are often used as the starting point in modern drug discovery. Many biologically interesting natural products are however not being pursued as potential drug candidates, partly due to a lack of well-defined mechanism-of-action. Traditional in vitro methods for target identification of natural products based on affinity protein enrichment from crude cellular lysates cannot faithfully recapitulate protein-drug interactions in living cells. Reported herein are dual-purpose probes inspired by the natural product andrographolide, capable of both reaction-based, real-time bioimaging and in situ proteome profiling/target identification in live mammalian cells. Our results confirm that andrographolide is a highly promiscuous compound and engaged in covalent interactions with numerous previously unknown cellular targets in cell type-specific manner. We caution its potential therapeutic effects should be further investigated in detail.

  8. Deformation mechanism in graphene nanoplatelet reinforced tantalum carbide using high load in situ indentation

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Cheng; Boesl, Benjamin [Plasma Forming Laboratory, Department of Mechanical and Materials Engineering, Florida International University, Miami, FL 33174 (United States); Silvestroni, Laura; Sciti, Diletta [Institute of Science and Technology for Ceramics (ISTEC), CNR-ISTEC, Via Granarolo 64, 48018 Faenza (Italy); Agarwal, Arvind, E-mail: agarwala@fiu.edu [Plasma Forming Laboratory, Department of Mechanical and Materials Engineering, Florida International University, Miami, FL 33174 (United States)

    2016-09-30

    High load in-situ indentation testing with real time SEM imaging was carried out on spark plasma sintered graphene nanoplatelets (GNP) reinforced TaC composites. The prime goal of this study was to understand the deformation behavior and the reinforcing mechanisms of GNPs. The results suggest that addition of GNPs had significant effect on dissipating indentation energy and confining the overall damage area to a localized region of TaC. The average crack length reduced by 26% whereas total damage area shrunk by 85% in TaC-5 vol% GNP sample as compared to pure TaC. TEM analysis concluded that well dispersed GNPs result in a strong and clean interface between TaC and GNP with trace amount of amorphous layer that leads to improved energy dissipation mechanism.

  9. Nitrate removal from alkaline high nitrate effluent by in situ generation of hydrogen using zinc dust

    International Nuclear Information System (INIS)

    Rajagopal, S.; Chitra, S.; Paul, Biplob

    2016-01-01

    Alkaline radioactive low level waste generated in Nuclear Fuel Cycle contains substantial amount of nitrate and needs to be treated to meet Central Pollution Control Board discharge limits of 90 mg/L in marine coastal area. Several denitrification methods like chemical treatment, electrochemical reduction, biological denitrification, ion exchange, reverse osmosis, photochemical reduction etc are followed for removal of nitrate. In effluent treatment plants where chemical treatment is carried out, chemical denitrification can be easily adapted without any additional set up. Reducing agents like zinc and aluminum are suitable for reducing nitrate in alkaline solution. Study on denitrification with zinc dust was taken up in this work. Not much work has been done with zinc dust on reduction of nitrate to nitrogen in alkaline waste with high nitrate content. In the present work, nitrate is reduced by nascent hydrogen generated in situ, caused by reaction between zinc dust and sodium hydroxide

  10. In-situ identification of marine organisms using high frequency, wideband ultrasound

    DEFF Research Database (Denmark)

    Pham, An Hoai

    methods. Conventional acoustical methods use frequencies in the range of 10 to 500 kHz and give reasonable estimations of size distribution, if the species is known, but can only significantly support the determination of the actual species, if there are only a few known species available. It is expected...... that higher frequencies and broader bandwidths than used until now will give more information useful for fish species identification. The objective of this Ph.D. study has been to develop a method to investigate the possibility of in-situ identification of fish with high-frequency, wideband ultrasound...... and the fish bodies. The frequencies are 2, 3.5, and 6 MHz. The angles are -30°, -15°, 0°, 15°, and 30°. The results show that even though there are variations, a scan of the ultrasound backscatter along a fish of a specific species contains patterns that are characteristic for that species. This is true...

  11. Synthesis and characterization of an in situ forming hydrogel using tyramine conjugated high methoxyl gum tragacanth.

    Science.gov (United States)

    Tavakol, Moslem; Vasheghani-Farahani, Ebrahim; Mohammadifar, Mohammad Amin; Soleimani, Masoud; Hashemi-Najafabadi, Sameereh

    2016-02-01

    In this study, an enzyme catalyzed in situ forming hydrogel based on tyramine conjugated high methoxyl content gum tragacanth (TA-HMGT) was prepared and characterized. TA-HMGT was synthesized via heterogeneous ammonolysis of methyl ester groups of HMGT. Then, the hydrogel was prepared via horseradish peroxidase catalyzed coupling reaction in the presence of hydrogen peroxide. Hydrogel properties, such as gelation time, swelling/degradation behavior and rheological properties could be adjusted by tuning the gelation parameters and extent of tyramine conjugation. This system was a soft elastic hydrogel with appropriate biocompatibility. The fast gelation of the hydrogel is desirable for clinical applications. Also, in vitro bovine serum albumin release from the synthesized hydrogel showed good release profile with limited burst release. © The Author(s) 2015.

  12. Engineering assessment of in situ sulfate production onboard aircraft at high altitude

    Science.gov (United States)

    Smith, J.; Dykema, J. A.; Keith, D.

    2016-12-01

    Stratospheric injection of scattering aerosols has been proposed as a way to reduce global temperature increases by decreasing net atmospheric radiative forcing. Several methods have been suggested as a means of implementing solar geoengineering, and high altitude aircraft have been identified as an accessible means delivering sulfate aerosols to the lower and mid-stratosphere. This research initiative analyzes the design features of an onboard open cycle chemical plant capable of in situ sulfur to sulfate conversion, and compares the required mass to that of transporting pre-fabricated gaseous or liquid sulfate aerosol precursors. Scaling from aero-derivative gas turbine engines, commercial catalytic converters, and existing aerospace materials indicate that aircraft equipped with such a system could provide a substantial mass benefit compared to direct transport of compound sulfate products.

  13. In-situ tensile test of high strength nanocrystalline bainitic steel

    Energy Technology Data Exchange (ETDEWEB)

    Haddad, Mike, E-mail: mike.haddad@uni-ulm.de [Institute of Micro and Nanomaterials, University of Ulm, Ulm (Germany); Ivanisenko, Yulia; Courtois-Manara, Eglantine [Institute of Nanotechnology, Karlsruhe Institute of Technology, Karlsruhe (Germany); Fecht, Hans-Jörg [Institute of Micro and Nanomaterials, University of Ulm, Ulm (Germany)

    2015-01-03

    Because of its great importance in modern engineering and technology applications, steel continues to be highly relevant in the modern research field of nanocrystalline materials. Innovative processing methods and procedures are required for the production of such materials, which possess superior properties compared to their conventional counter parts. In this research, the original microstructure of a commercial C45 steel (Fe, 0.42–0.5 wt% C, 0.5–0.8 wt% Mn) was modified from ferritic–pearlitic to bainitic. Warm high pressure torsion for 5 rotations at 6 GPa and 350 °C was used to process the bainitic sample leading to an ultrafine/nano-scale grain size. A unique nano-crystalline microstructure consisting of equiaxed and elongated ferrite grains with a mean size smaller than 150 nm appeared in images taken by Transmission Electron Microscopy. Results of in-situ tensile testing in a scanning electron microscope showed very high tensile strength, on the order of 2100 MPa with a total elongation of 4.5% in comparison with 800 MPa and around 16% in the original state. Fracture occurred abruptly, without any sign of necking, and was typically caused by the stress concentration at a surface flaw. Also, stress concentrations near all surface defects were observed on the sample, visualized by the formation of shear bands. The fracture surface was covered with dimples, indicating ductile fracture. These properties are fully comparable with high strength, high alloyed steels.

  14. Highly sensitive and multiplexed platforms for allergy diagnostics

    Science.gov (United States)

    Monroe, Margo R.

    Allergy is a disorder of the immune system caused by an immune response to otherwise harmless environmental allergens. Currently 20% of the US population is allergic and 90% of pediatric patients and 60% of adult patients with asthma have allergies. These percentages have increased by 18.5% in the past decade, with predicted similar trends for the future. Here we design sensitive, multiplexed platforms to detect allergen-specific IgE using the Interferometric Reflectance Imaging Sensor (IRIS) for various clinical settings. A microarray platform for allergy diagnosis allows for testing of specific IgE sensitivity to a multitude of allergens, while requiring only small volumes of patient blood sample. However, conventional fluorescent microarray technology is limited by i) the variation of probe immobilization, which hinders the ability to make quantitative, assertive, and statistically relevant conclusions necessary in immunodiagnostics and ii) the use of fluorophore labels, which is not suitable for some clinical applications due to the tendency of fluorophores to stick to blood particulates and require daily calibration methods. This calibrated fluorescence enhancement (CaFE) method integrates the low magnification modality of IRIS with enhanced fluorescence sensing in order to directly correlate immobilized probe (major allergens) density to allergen-specific IgE in patient serum. However, this platform only operates in processed serum samples, which is not ideal for point of care testing. Thus, a high magnification modality of IRIS was adapted as an alternative allergy diagnostic platform to automatically discriminate and size single nanoparticles bound to specific IgE in unprocessed, characterized human blood and serum samples. These features make IRIS an ideal candidate for clinical and diagnostic applications, such a POC testing. The high magnification (nanoparticle counting) modality in conjunction with low magnification of IRIS in a combined instrument

  15. High-reliability emergency response teams in the hospital: improving quality and safety using in situ simulation training.

    Science.gov (United States)

    Wheeler, Derek S; Geis, Gary; Mack, Elizabeth H; LeMaster, Tom; Patterson, Mary D

    2013-06-01

    In situ simulation training is a team-based training technique conducted on actual patient care units using equipment and resources from that unit, and involving actual members of the healthcare team. We describe our experience with in situ simulation training in a major children's medical centre. In situ simulations were conducted using standardised scenarios approximately twice per month on inpatient hospital units on a rotating basis. Simulations were scheduled so that each unit participated in at least two in situ simulations per year. Simulations were conducted on a revolving schedule alternating on the day and night shifts and were unannounced. Scenarios were preselected to maximise the educational experience, and frequently involved clinical deterioration to cardiopulmonary arrest. We performed 64 of the scheduled 112 (57%) in situ simulations on all shifts and all units over 21 months. We identified 134 latent safety threats and knowledge gaps during these in situ simulations, which we categorised as medication, equipment, and/or resource/system threats. Identification of these errors resulted in modification of systems to reduce the risk of error. In situ simulations also provided a method to reinforce teamwork behaviours, such as the use of assertive statements, role clarity, performance of frequent updating, development of a shared mental model, performance of independent double checks of high-risk medicines, and overcoming authority gradients between team members. Participants stated that the training programme was effective and did not disrupt patient care. In situ simulations can identify latent safety threats, identify knowledge gaps, and reinforce teamwork behaviours when used as part of an organisation-wide safety programme.

  16. In situ oxide dispersion strengthened tungsten alloys with high compressive strength and high strain-to-failure

    International Nuclear Information System (INIS)

    Huang, Lin; Jiang, Lin; Topping, Troy D.; Dai, Chen; Wang, Xin; Carpenter, Ryan; Haines, Christopher; Schoenung, Julie M.

    2017-01-01

    In this work a novel process methodology to concurrently improve the compressive strength (2078 MPa at a strain rate of 5 × 10"−"4 s"−"1) and strain-to-failure (over 40%) of bulk tungsten materials has been described. The process involves the in situ formation of intragranular tungsten oxide nanoparticles, facilitated by the application of a pressure of 1 GPa at a low sintering temperature of 1200 °C during spark plasma sintering (SPS). The results show that the application of a high pressure of 1 GPa during SPS significantly accelerates the densification process. Concurrently, the second phase oxide nanoparticles with an average grain size of 108 nm, which are distributed within the interiors of the W grains, simultaneously provide strengthening and plasticity by inhibiting grain growth, and generating, blocking, and storing dislocations. - Graphical abstract: In this work a novel process methodology to concurrently improve the compressive strength (2078 MPa at a strain rate of 5 × 10"−"4 s"−"1) and strain-to-failure (over 40%) of bulk W materials has been described. The process involves the in situ formation of intragranular tungsten oxide nanoparticles, facilitated by the application of a pressure of 1 GPa at a low sintering temperature of 1200 °C during spark plasma sintering (SPS).

  17. High salinity tolerance of the Red Sea coral Fungia granulosa under desalination concentrate discharge conditions: an in situ photophysiology experiment

    KAUST Repository

    Van Der Merwe, Riaan

    2014-11-10

    Seawater reverse osmosis desalination concentrate may have chronic and/or acute impacts on the marine ecosystems in the near-field area of the discharge. Environmental impact of the desalination plant discharge is supposedly site- and volumetric- specific, and also depends on the salinity tolerance of the organisms inhabiting the water column in and around a discharge environment. Scientific studies that aim to understand possible impacts of elevated salinity levels are important to assess detrimental effects to organisms, especially for species with no mechanism of osmoregulation, e.g., presumably corals. Previous studies on corals indicate sensitivity toward hypo- and hyper-saline environments with small changes in salinity already affecting coral physiology. In order to evaluate sensitivity of Red Sea corals to increased salinity levels, we conducted a long-term (29 days) in situ salinity tolerance transect study at an offshore seawater reverse osmosis (SWRO) discharge on the coral Fungia granulosa. While we measured a pronounced increase in salinity and temperature at the direct outlet of the discharge structure, effects were indistinguishable from the surrounding environment at a distance of 5 m. Interestingly, corals were not affected by varying salinity levels as indicated by measurements of the photosynthetic efficiency. Similarly, cultured coral symbionts of the genus Symbiodinium displayed remarkable tolerance levels in regard to hypo- and hypersaline treatments. Our data suggest that increased salinity and temperature levels from discharge outlets wear off quickly in the surrounding environment. Furthermore, F. granulosa seem to tolerate levels of salinity that are distinctively higher than reported for other corals previously. It remains to be determined whether Red Sea corals in general display increased salinity tolerance, and whether this is related to prevailing levels of high(er) salinity in the Red Sea in comparison to other oceans.

  18. Adjoint sensitivity analysis of high frequency structures with Matlab

    CERN Document Server

    Bakr, Mohamed; Demir, Veysel

    2017-01-01

    This book covers the theory of adjoint sensitivity analysis and uses the popular FDTD (finite-difference time-domain) method to show how wideband sensitivities can be efficiently estimated for different types of materials and structures. It includes a variety of MATLAB® examples to help readers absorb the content more easily.

  19. Polypyrrole–gold nanoparticle composites for highly sensitive DNA detection

    International Nuclear Information System (INIS)

    Spain, Elaine; Keyes, Tia E.; Forster, Robert J.

    2013-01-01

    DNA capture surfaces represent a powerful approach to developing highly sensitive sensors for identifying the cause of infection. Electrochemically deposited polypyrrole, PPy, films have been functionalized with electrodeposited gold nanoparticles to give a nanocomposite material, PPy–AuNP. Thiolated capture strand DNA, that is complementary to the sequence from the pathogen Staphylococcus aureus that causes mammary gland inflammation, was then immobilized onto the gold nanoparticles and any of the underlying gold electrode that is exposed. A probe strand, labelled with horse radish peroxidase, HRP, was then hybridized to the target. The concentration of the target was determined by measuring the current generated by reducing benzoquinone produced by the HRP label. Semi-log plots of the pathogen DNA concentration vs. faradaic current are linear from 150 pM to 1 μM and pM concentrations can be detected without the need for molecular, e.g., PCR or NASBA, amplification. The nanocomposite also exhibits excellent selectivity and single base mismatches in a 30 mer sequence can be detected

  20. Improvement of sensitivity in high-resolution Rutherford backscattering spectroscopy

    International Nuclear Information System (INIS)

    Hashimoto, H.; Nakajima, K.; Suzuki, M.; Kimura, K.; Sasakawa, K.

    2011-01-01

    The sensitivity (limit of detection) of high-resolution Rutherford backscattering spectroscopy (HRBS) is mainly determined by the background noise of the spectrometer. There are two major origins of the background noise in HRBS, one is the stray ions scattered from the inner wall of the vacuum chamber of the spectrometer and the other is the dark noise of the microchannel plate (MCP) detector which is commonly used as a focal plane detector of the spectrometer in HRBS. In order to reject the stray ions, several barriers are installed inside the spectrometer and a thin Mylar foil is mounted in front of the detector. The dark noise of the MCP detector is rejected by the coincidence measurement with the secondary electrons emitted from the Mylar foil upon the ion passage. After these improvements, the background noise is reduced by a factor of 200 at a maximum. The detection limit can be improved down to 10 ppm for As in Si at a measurement time of 1 h under ideal conditions.

  1. Highly sensitive MoS2 photodetectors with graphene contacts

    Science.gov (United States)

    Han, Peize; St. Marie, Luke; Wang, Qing X.; Quirk, Nicholas; El Fatimy, Abdel; Ishigami, Masahiro; Barbara, Paola

    2018-05-01

    Two-dimensional materials such as graphene and transition metal dichalcogenides (TMDs) are ideal candidates to create ultra-thin electronics suitable for flexible substrates. Although optoelectronic devices based on TMDs have demonstrated remarkable performance, scalability is still a significant issue. Most devices are created using techniques that are not suitable for mass production, such as mechanical exfoliation of monolayer flakes and patterning by electron-beam lithography. Here we show that large-area MoS2 grown by chemical vapor deposition and patterned by photolithography yields highly sensitive photodetectors, with record shot-noise-limited detectivities of 8.7 × 1014 Jones in ambient condition and even higher when sealed with a protective layer. These detectivity values are higher than the highest values reported for photodetectors based on exfoliated MoS2. We study MoS2 devices with gold electrodes and graphene electrodes. The devices with graphene electrodes have a tunable band alignment and are especially attractive for scalable ultra-thin flexible optoelectronics.

  2. Ultra-high sensitivity imaging of cancer using SERRS nanoparticles

    Science.gov (United States)

    Kircher, Moritz F.

    2016-05-01

    "Surface-enhanced Raman spectroscopy" (SERS) nanoparticles have gained much attention in recent years for in silico, in vitro and in vivo sensing applications. Our group has developed novel generations of biocompatible "surfaceenhanced resonance Raman spectroscopy" (SERRS) nanoparticles as novel molecular imaging agents. Via rigorous optimization of the different variables contributing to the Raman enhancement, we were able to design SERRS nanoparticles with so far unprecedented sensitivity of detection under in vivo imaging conditions (femto-attomolar range). This has resulted in our ability to visualize, with a single nanoparticle, many different cancer types (after intravenous injection) in mouse models. The cancer types we have tested so far include brain, breast, esophagus, stomach, pancreas, colon, sarcoma, and prostate cancer. All mouse models used are state-of-the-art and closely mimic the tumor biology in their human counterparts. In these animals, we were able to visualize not only the bulk tumors, but importantly also microscopic extensions and locoregional satellite metastases, thus delineating for the first time the true extent of tumor spread. Moreover, the particles enable the detection of premalignant lesions. Given their inert composition they are expected to have a high chance for clinical translation, where we envision them to have an impact in various scenarios ranging from early detection, image-guidance in open or minimally invasive surgical procedures, to noninvasive imaging in conjunction with spatially offset (SESORS) Raman detection devices.

  3. Characterization of three high efficiency and blue sensitive silicon photomultipliers

    Energy Technology Data Exchange (ETDEWEB)

    Otte, Adam Nepomuk, E-mail: otte@gatech.edu; Garcia, Distefano; Nguyen, Thanh; Purushotham, Dhruv

    2017-02-21

    We report about the optical and electrical characterization of three high efficiency and blue sensitive Silicon photomultipliers from FBK, Hamamatsu, and SensL. Key features of the tested devices when operated at 90% breakdown probability are peak photon detection efficiencies between 40% and 55%, temperature dependencies of gain and PDE that are less than 1%/°C, dark rates of ∼50 kHz/mm{sup 2} at room temperature, afterpulsing of about 2%, and direct optical crosstalk between 6% and 20%. The characteristics of all three devices impressively demonstrate how the Silicon-photomultiplier technology has improved over the past ten years. It is further demonstrated how the voltage and temperature characteristics of a number of quantities can be parameterized on the basis of physical models. The models provide a deeper understanding of the device characteristics over a wide bias and temperature range. They also serve as examples how producers could provide the characteristics of their SiPMs to users. A standardized parameterization of SiPMs would enable users to find the optimal SiPM for their application and the operating point of SiPMs without having to perform measurements thus significantly reducing design and development cycles.

  4. Molecular Tagging Velocimetry Development for In-situ Measurement in High-Temperature Test Facility

    Science.gov (United States)

    Andre, Matthieu A.; Bardet, Philippe M.; Burns, Ross A.; Danehy, Paul M.

    2015-01-01

    The High Temperature Test Facility, HTTF, at Oregon State University (OSU) is an integral-effect test facility designed to model the behavior of a Very High Temperature Gas Reactor (VHTR) during a Depressurized Conduction Cooldown (DCC) event. It also has the ability to conduct limited investigations into the progression of a Pressurized Conduction Cooldown (PCC) event in addition to phenomena occurring during normal operations. Both of these phenomena will be studied with in-situ velocity field measurements. Experimental measurements of velocity are critical to provide proper boundary conditions to validate CFD codes, as well as developing correlations for system level codes, such as RELAP5 (http://www4vip.inl.gov/relap5/). Such data will be the first acquired in the HTTF and will introduce a diagnostic with numerous other applications to the field of nuclear thermal hydraulics. A laser-based optical diagnostic under development at The George Washington University (GWU) is presented; the technique is demonstrated with velocity data obtained in ambient temperature air, and adaptation to high-pressure, high-temperature flow is discussed.

  5. The Silicon Environment in Silica Polymorphs, Aluminosilicate Crystals and Melts: An In Situ High Temperature XAS Study

    International Nuclear Information System (INIS)

    Cormier, L.; Neuville, D. R.; Roux, J.; Ligny, D. de; Henderson, G. S.; Flank, A.-M.; Lagarde, P.

    2007-01-01

    High temperature X-ray absorption spectroscopy at the Si K-edge has been used to obtain in situ information on SiO2 phase transitions upon heating. Important modifications are observed for the XANES spectra of the high temperature polymorphs, in relation to disordering of the SiO4 tetrahedra beyond the short-range correlations. This paper also presents the XANES spectra of anorthite (CaAl2Si2O8) from room temperature up to the melt (1900 K). This study shows the possibilities for determining the Si environment in crystals and glasses up to the liquid state using in situ XANES measurements

  6. Introducing wet aerosols into the static high sensitivity ICP (SHIP)

    Energy Technology Data Exchange (ETDEWEB)

    Scheffer, Andy; Engelhard, Carsten; Sperling, Michael; Buscher, Wolfgang [University of Muenster, Institute of Inorganic and Analytical Chemistry, Muenster (Germany)

    2007-08-15

    A demountable design of the static high sensitivity ICP (SHIP) for optical emission spectrometry is presented, and its use as an excitation source with the introduction of wet aerosols was investigated. Aerosols were produced by standard pneumatic sample introduction systems, namely a cross flow nebulizer, Meinhard nebulizer and PFA low flow nebulizer, which have been applied in conjunction with a double pass and a cyclonic spray chamber. The analytical capabilities of these sample introduction systems in combination with the SHIP system were evaluated with respect to the achieved sensitivity. It was found that a nebulizer tailored for low argon flow rates (0.3-0.5 L min{sup -1}) is best suited for the low flow plasma (SHIP). An optimization of all gas flow rates of the SHIP system with the PFA low flow nebulizer was carried out in a two-dimensional way with the signal to background ratio (SBR) and the robustness as optimization target parameters. Optimum conditions for a torch model with 1-mm injector tube were 0.25 and 0.36 L min{sup -1} for the plasma gas and the nebulizer gas, respectively. A torch model with a 2-mm injector tube was optimized to 0.4 L min{sup -1} for the plasma gas and 0.44 L min{sup -1} for the nebulizer gas. In both cases the SHIP system saves approximately 95% of the argon consumed by conventional inductively coupled plasma systems. The limits of detection were found to be in the low microgram per litre range and below for many elements, which was quite comparable to those of the conventional setup. Furthermore, the short-term stability and the wash out behaviour of the SHIP were investigated. Direct comparison with the conventional setup indicated that no remarkable memory effects were caused by the closed design of the torch. The analysis of a NIST SRM 1643e (Trace Elements in Water) with the SHIP yielded recoveries of 97-103% for 13 elements, measured simultaneously. (orig.)

  7. Real-time monitoring of high-gravity corn mash fermentation using in situ raman spectroscopy.

    Science.gov (United States)

    Gray, Steven R; Peretti, Steven W; Lamb, H Henry

    2013-06-01

    In situ Raman spectroscopy was employed for real-time monitoring of simultaneous saccharification and fermentation (SSF) of corn mash by an industrial strain of Saccharomyces cerevisiae. An accurate univariate calibration model for ethanol was developed based on the very strong 883 cm(-1) C-C stretching band. Multivariate partial least squares (PLS) calibration models for total starch, dextrins, maltotriose, maltose, glucose, and ethanol were developed using data from eight batch fermentations and validated using predictions for a separate batch. The starch, ethanol, and dextrins models showed significant prediction improvement when the calibration data were divided into separate high- and low-concentration sets. Collinearity between the ethanol and starch models was avoided by excluding regions containing strong ethanol peaks from the starch model and, conversely, excluding regions containing strong saccharide peaks from the ethanol model. The two-set calibration models for starch (R(2)  = 0.998, percent error = 2.5%) and ethanol (R(2)  = 0.999, percent error = 2.1%) provide more accurate predictions than any previously published spectroscopic models. Glucose, maltose, and maltotriose are modeled to accuracy comparable to previous work on less complex fermentation processes. Our results demonstrate that Raman spectroscopy is capable of real time in situ monitoring of a complex industrial biomass fermentation. To our knowledge, this is the first PLS-based chemometric modeling of corn mash fermentation under typical industrial conditions, and the first Raman-based monitoring of a fermentation process with glucose, oligosaccharides and polysaccharides present. Copyright © 2013 Wiley Periodicals, Inc.

  8. Efficiency enhancement in dye-sensitized solar cells by in situ passivation of the sensitized nanoporous electrode with Li2CO3

    International Nuclear Information System (INIS)

    Zhang Jingbo; Zaban, Arie

    2008-01-01

    This work entails a method to improve the performance of dye-sensitized nanocrystalline TiO 2 solar cells by adding surface passivating elements to the electrolyte. The presence of either CO 2 , Li 2 CO 3 or K 2 CO 3 in electrolyte increases both the photocurrent and the photovoltage, resulting in higher overall conversion efficiency of these solar cells. The additives are used to form a passivation layer of lithium carbonate on the dye free surface of the TiO 2 nanoparticles and the conductive substrate. This layer suppresses the rate of the main recombination reaction between the photoinjected electrons and the oxidized ions in the electrolyte solution. While blocking part of the recombination, the lithium carbonate layer allows motion of the Li + ions towards the TiO 2 surface for charge screening. Consequently using this simple treatment, the conversion efficiency of dye-sensitized solar cell most improved by 17.2% (from 6.4% to 7.5%)

  9. Homogeneous vertical ZnO nanorod arrays with high conductivity on an in situ Gd nanolayer

    KAUST Repository

    Flemban, Tahani H.

    2015-10-30

    We demonstrate a novel, one-step, catalyst-free method for the production of size-controlled vertical highly conductive ZnO nanorod (NR) arrays with highly desirable characteristics by pulsed laser deposition using a Gd-doped ZnO target. Our study shows that an in situ transparent and conductive Gd nanolayer (with a uniform thickness of ∼1 nm) at the interface between a lattice-matched (11-20) a-sapphire substrate and ZnO is formed during the deposition. This nanolayer significantly induces a relaxation mechanism that controls the dislocation distribution along the growth direction; which consequently improves the formation of homogeneous vertically aligned ZnO NRs. We demonstrate that both the lattice orientation of the substrate and the Gd characteristics are important in enhancing the NR synthesis, and we report precise control of the NR density by changing the oxygen partial pressure. We show that these NRs possess high optical and electrical quality, with a mobility of 177 cm2 (V s)-1, which is comparable to the best-reported mobility of ZnO NRs. Therefore, this new and simple method has significant potential for improving the performance of materials used in a wide range of electronic and optoelectronic applications.

  10. Single-Crystal Tungsten Carbide in High-Temperature In-Situ Additive Manufacturing Characterization

    Energy Technology Data Exchange (ETDEWEB)

    Kolopus, James A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Boatner, Lynn A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2017-05-18

    Nanoindenters are commonly used for measuring the mechanical properties of a wide variety of materials with both industrial and scientific applications. Typically, these instruments employ an indenter made of a material of suitable hardness bonded to an appropriate shaft or holder to create an indentation on the material being tested. While a variety of materials may be employed for the indenter, diamond and boron carbide are by far the most common materials used due to their hardness and other desirable properties. However, as the increasing complexity of new materials demands a broader range of testing capabilities, conventional indenter materials exhibit significant performance limitations. Among these are the inability of diamond indenters to perform in-situ measurements at temperatures above 600oC in air due to oxidation of the diamond material and subsequent degradation of the indenters mechanical properties. Similarly, boron carbide also fails at high temperature due to fracture. [1] Transition metal carbides possess a combination of hardness and mechanical properties at high temperatures that offer an attractive alternative to conventional indenter materials. Here we describe the technical aspects for the growth of single-crystal tungsten carbide (WC) for use as a high-temperature indenter material, and we examine a possible approach to brazing these crystals to a suitable mount for grinding and attachment to the indenter instrument. The use of a by-product of the recovery process is also suggested as possibly having commercial value.

  11. Early rhegmatogenous retinal detachment following laser in situ keratomileusis for high myopia.

    Science.gov (United States)

    Farah, M E; Höfling-Lima, A L; Nascimento, E

    2000-01-01

    Four eyes had early rhegmatogenous retinal detachment within 3 months of laser in situ keratomileusis (LASIK) for correction of high myopia using the microkeratome, Clear Corneal Molder. In two eyes, retinal detachment resulted from horseshoe tears, one occurring in an otherwise normal region of the retina and the other at the margin of an area of lattice degeneration detected during preoperative examination. The first eye was treated with retinopexy using a 287 encircling scleral exoplant, drainage of subretinal fluid, and laser photocoagulation by indirect ophthalmoscopy. The other eye was treated with pneumatic retinopexy and cryotherapy. In the other eyes, retinal detachment was the result of giant tears with no evidence of prior retinal degeneration. These eyes were treated with pars plana vitrectomy, fluid-gas exchange with 15% perfluoropropane (C3F8), endolaser photocoagulation, and a 42 encircling scleral exoplant. After treatment, the first two eyes achieved spectacle-corrected visual acuity of 20/40. In the last two eyes, final spectacle-corrected visual acuity was 20/400 in one eye and light perception in the other. Although no cause-effect relationship between LASIK and retinal detachment can be stated, these cases suggest that LASIK may be associated with retinal detachment, particularly in highly myopic eyes. Further studies are necessary to determine high-risk patient characteristics.

  12. Highly efficient dye-sensitized solar cell with GNS/MWCNT/PANI as a counter electrode

    International Nuclear Information System (INIS)

    Al-bahrani, Majid Raissan; Xu, Xiaobao; Ahmad, Waqar; Ren, Xiaoliang; Su, Jun; Cheng, Ze; Gao, Yihua

    2014-01-01

    Highlights: • High-performance PANI/MWCNT-CE was incorporated in a Pt-CE in DSSCs. • GNS/MWCNT/PANI-CE exhibits a high power conversion efficiency (PCE) of 7.52%. • GNS/MWCNT/PANI composite has a high catalytic activity for the reduction of I 3 − . • GNS/MWCNT/PANI composite has a low R CT on the electrolyte/CE interface. - Abstract: A graphene-based nanosheet composite/multiwalled carbon nanotube/polyaniline (GNS/MWCNT/PANI) was synthesized via an in situ polymerization technique and applied by the spin-coating method as a counter electrode (CE) in dye-sensitized solar cells (DSSCs). The combination of the high catalytic activity of PANI and outstanding conductivity of GNS/MWCNT improved the photovoltaic performance of the hybrid CE. The cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) showed that the GNS/MWCNT/PANI composite has high catalytic activity for the reduction of triiodide to iodide and low charge-transfer resistance at the electrolyte/electrode interface. Transmission electron microscopy (TEM) images showed that the GNS/MWCNT/PANI-CE has a rough and porous structure and X-ray diffraction analysis confirmed the formation of PANI coating on the surface of the GNS/CNT. In particular, current–voltage measurements showed the superior power conversion efficiency (PCE) of 7.52% of the DSSC based on GNS/MWCNT/PANI-CE compared to the PCE of 6.69% of the DSSC based on Pt-CE

  13. Highly efficient dye-sensitized solar cell with GNS/MWCNT/PANI as a counter electrode

    Energy Technology Data Exchange (ETDEWEB)

    Al-bahrani, Majid Raissan [Center for Nanoscale Characterization and Devices (CNCD), Wuhan National Laboratory for Optoelectronics (WNLO)-School of Physics, Huazhong University of Science and Technology - HUST, Luoyu Road 1037, Wuhan 430074 (China); Faculty of Science, Thi-Qar University, Nassiriya (Iraq); Xu, Xiaobao [Michael Grätzel Center for Mesoscopic Solar Cells, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, 1037 Luoyu Road, 430074 Wuhan (China); Ahmad, Waqar; Ren, Xiaoliang; Su, Jun [Center for Nanoscale Characterization and Devices (CNCD), Wuhan National Laboratory for Optoelectronics (WNLO)-School of Physics, Huazhong University of Science and Technology - HUST, Luoyu Road 1037, Wuhan 430074 (China); Cheng, Ze [School of Physics, Huazhong University of Science and Technology (HUST), Luoyu Road 1037, Wuhan 430074 (China); Gao, Yihua, E-mail: gaoyihua@hust.edu.cn [Center for Nanoscale Characterization and Devices (CNCD), Wuhan National Laboratory for Optoelectronics (WNLO)-School of Physics, Huazhong University of Science and Technology - HUST, Luoyu Road 1037, Wuhan 430074 (China)

    2014-11-15

    Highlights: • High-performance PANI/MWCNT-CE was incorporated in a Pt-CE in DSSCs. • GNS/MWCNT/PANI-CE exhibits a high power conversion efficiency (PCE) of 7.52%. • GNS/MWCNT/PANI composite has a high catalytic activity for the reduction of I{sub 3}{sup −}. • GNS/MWCNT/PANI composite has a low R{sub CT} on the electrolyte/CE interface. - Abstract: A graphene-based nanosheet composite/multiwalled carbon nanotube/polyaniline (GNS/MWCNT/PANI) was synthesized via an in situ polymerization technique and applied by the spin-coating method as a counter electrode (CE) in dye-sensitized solar cells (DSSCs). The combination of the high catalytic activity of PANI and outstanding conductivity of GNS/MWCNT improved the photovoltaic performance of the hybrid CE. The cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) showed that the GNS/MWCNT/PANI composite has high catalytic activity for the reduction of triiodide to iodide and low charge-transfer resistance at the electrolyte/electrode interface. Transmission electron microscopy (TEM) images showed that the GNS/MWCNT/PANI-CE has a rough and porous structure and X-ray diffraction analysis confirmed the formation of PANI coating on the surface of the GNS/CNT. In particular, current–voltage measurements showed the superior power conversion efficiency (PCE) of 7.52% of the DSSC based on GNS/MWCNT/PANI-CE compared to the PCE of 6.69% of the DSSC based on Pt-CE.

  14. In situ electropolymerization of polyaniline/cobalt sulfide decorated carbon nanotube composite catalyst toward triiodide reduction in dye-sensitized solar cells

    Science.gov (United States)

    Xiao, Yaoming; Wang, Wei-Yan; Chou, Shu-Wei; Lin, Tsung-Wu; Lin, Jeng-Yu

    2014-11-01

    In this study, we report a composite film composed of the cobalt sulfide (CoS1.097) nanoclusters/multi-wall carbon nanotube nanocomposites (MWCNT@CoS1.097) embedded polyaniline (PANI) film (denoted as PANI/MWCNT@CoS1.097) by an in situ electropolymerization onto a fluorinated tin oxide (FTO) glass substrate as a counter electrode (CE) for Pt-free dye-sensitized solar cells (DSCs) for the first time. The extensive cyclic voltammograms (CVs) and electrochemical impedance measurements show the PANI/MWCNT@CoS1.097 CE with an enhanced electrocatalytic activity for I3- reduction compared to PANI and MWCNT@CoS1.097 CEs. Moreover, the peak current densities of the PANI/MWCNT@CoS1.097 CE show no sign of degradation after consecutive 200 CV tests, suggesting its great chemical and electrochemical stability. Furthermore, the DSC based on the in situ electropolymerized PANI/MWCNT@CoS1.097 CE achieves an improved photovoltaic conversion efficiency of 7.02%, which is higher than those of the DSCs with PANI CE (6.06%) and with MWCNT@CoS1.097 CE (5.54%), and is even comparable to that of the DSC using the Pt CE (7.16%). Therefore, the PANI/MWCNT@CoS1.097 CE can be regarded as a promising alternative CE for Pt-free DSCs.

  15. InAlN high electron mobility transistor Ti/Al/Ni/Au Ohmic contact optimisation assisted by in-situ high temperature transmission electron microscopy

    International Nuclear Information System (INIS)

    Smith, M. D.; Parbrook, P. J.; O'Mahony, D.; Conroy, M.; Schmidt, M.

    2015-01-01

    This paper correlates the micro-structural and electrical characteristics associated with annealing of metallic multi-layers typically used in the formation of Ohmic contacts to InAlN high electron mobility transistors. The multi-layers comprised Ti/Al/Ni/Au and were annealed via rapid thermal processing at temperatures up to 925 °C with electrical current-voltage analysis establishing the onset of Ohmic (linear IV) behaviour at 750–800 °C. In-situ temperature dependent transmission electron microscopy established that metallic diffusion and inter-mixing were initiated near a temperature of 500 °C. Around 800 °C, inter-diffusion of the metal and semiconductor (nitride) was observed, correlating with the onset of Ohmic electrical behaviour. The sheet resistance associated with the InAlN/AlN/GaN interface is highly sensitive to the anneal temperature, with the range depending on the Ti layer thickness. The relationship between contact resistivity and measurement temperature follow that predicted by thermionic field emission for contacts annealed below 850 °C, but deviated above this due to excessive metal-semiconductor inter-diffusion

  16. High-sensitivity Cardiac Troponin Elevation after Electroconvulsive Therapy (ECT)

    Science.gov (United States)

    Duma, Andreas; Pal, Swatilika; Johnston, Joshua; Helwani, Mohammad A.; Bhat, Adithya; Gill, Bali; Rosenkvist, Jessica; Cartmill, Christopher; Brown, Frank; Miller, J. Philip; Scott, Mitchell G; Sanchez-Conde, Francisco; Jarvis, Michael; Farber, Nuri B.; Zorumski, Charles F.; Conway, Charles; Nagele, Peter

    2017-01-01

    Background While electroconvulsive therapy (ECT) is widely regarded as a life-saving and safe procedure, evidence regarding its effects on myocardial cell injury are sparse. The objective of this investigation was to determine incidence and magnitude of new cardiac troponin elevation after ECT using a novel high-sensitivity cardiac troponin I (hscTnI) assay. Methods This was a prospective cohort study in adult patients undergoing ECT in a single academic center (up to three ECT treatments per patient). The primary outcome was new hscTnI elevation after ECT, defined as an increase of hscTnI >100% after ECT compared to baseline with at least one value above the limit of quantification (10 ng/L). 12-lead ECG and hscTnI values were obtained prior to and 15–30 minutes after ECT; in a subset of patients an additional 2-hour hscTnI value was obtained. Results The final study population was 100 patients and a total of 245 ECT treatment sessions. Eight patients (8/100, 8%) experienced new hscTnI elevation after ECT with a cumulative incidence of 3.7% (9/245 treatments; one patient had two hscTnI elevations), two of whom had a non-ST-elevation myocardial infarction (incidence 2/245, 0.8%). Median hscTnI concentrations did not increase significantly after ECT. Tachycardia and/or elevated systolic blood pressure developed after approximately two thirds of ECT treatments. Conclusions ECT appears safe from a cardiac standpoint in a large majority of patients. A small subset of patients with pre-existing cardiovascular risk factors, however, may develop new cardiac troponin elevation after ECT, the clinical relevance of which is unclear in the absence of signs of myocardial ischemia. PMID:28166110

  17. Sensitive in situ monitoring of a recombinant bioluminescent Yersinia enterocolitica reporter mutant in real time on Camembert cheese.

    Science.gov (United States)

    Maoz, Ariel; Mayr, Ralf; Bresolin, Geraldine; Neuhaus, Klaus; Francis, Kevin P; Scherer, Siegfried

    2002-11-01

    Bioluminescent mutants of Yersinia enterocolitica were generated by transposon mutagenesis using a promoterless, complete lux operon (luxCDABE) derived from Photorhabdus luminescens, and their production of light in the cheese environment was monitored. Mutant B94, which had the lux cassette inserted into an open reading frame of unknown function was used for direct monitoring of Y. enterocolitica cells on cheeses stored at 10 degrees C by quantifying bioluminescence using a photon-counting, intensified charge-coupled device camera. The detection limit on cheese was 200 CFU/cm(2). Bioluminescence of the reporter mutant was significantly regulated by its environment (NaCl, temperature, and cheese), as well as by growth phase, via the promoter the lux operon had acquired upon transposition. At low temperatures, mutant B94 did not exhibit the often-reported decrease of photon emission in older cells. It was not necessary to include either antibiotics or aldehyde in the food matrix in order to gain quantitative, reproducible bioluminescence data. As far as we know, this is the first time a pathogen has been monitored in situ, in real time, in a "real-product" status, and at a low temperature.

  18. pH-sensitive pHluorins as a molecular sensor for in situ monitoring of enzyme-catalyzed prodrug activation.

    Science.gov (United States)

    Liu, Hui; Cao, Xiaodan; Wang, Ping; Ma, Xingyuan

    2017-07-01

    This work examines the feasibility of using a pH-sensitive fluorescent protein as a molecular reporter for enzyme-catalyzed prodrug activation reaction. Specifically, a ratiometric pHluorins was examined for detection of the activity of horseradish peroxidase (HRP) for the activation of indole-3-acetic acid. The pHluorins and HRP were conjugated chemically, forming a biocatalyst with a self-reporting function. Results showed that the characteristic fluorescence intensity ratio of the conjugate shifted from 1.47 to 1.40 corresponding to the progress of the prodrug activation reaction. The effectiveness of applying the conjugate for inhibition of the growth of Bcap-37 cells was also demonstrated simultaneously with reaction monitoring. The results reveal a very promising approach to realizing in situ monitoring of enzyme activities based on pH shifting for enzyme-based prodrug therapy applications. © 2016 International Union of Biochemistry and Molecular Biology, Inc.

  19. Shock initiation sensitivity and Hugoniot-based equation of state of Composition B obtained using in situ electromagnetic gauging

    International Nuclear Information System (INIS)

    Gibson, L L; Bartram, B D; Sheffield, S A; Gustavsen, R L; Brown, G W; Sandstrom, M M; Giambra, A M; Dattelbaum, D M; Handley, C A

    2014-01-01

    A series of gas gun-driven plate impact experiments were performed on vacuum melt-cast Composition B to obtain new Hugoniot states and shock sensitivity (run-distance-to-detonation) information. The Comp B (ρ 0 = 1.713 g/cm 3 ) consisted of 59.5% RDX, 39.5% TNT, and 1% wax, with ∼ 6.5% HMX in the RDX. The measured Hugoniot states were found to be consistent with earlier reports, with the compressibility on the shock adiabat softer than that of a 63% RDX material reported by Marsh.[4] The shock sensitivity was found to be more sensitive (shorter run distance to detonation at a given shock input condition) than earlier reports for Comp B-3 and a lower density (1.68-1.69 g/cm 3 ) Comp B formulation. The reactive flow during the shock-to-detonation transition was marked by heterogeneous, hot spot-driven growth both in and behind the leading shock front.

  20. High-intensity xenon plasma discharge lamp for bulk-sensitive high-resolution photoemission spectroscopy.

    Science.gov (United States)

    Souma, S; Sato, T; Takahashi, T; Baltzer, P

    2007-12-01

    We have developed a highly brilliant xenon (Xe) discharge lamp operated by microwave-induced electron cyclotron resonance (ECR) for ultrahigh-resolution bulk-sensitive photoemission spectroscopy (PES). We observed at least eight strong radiation lines from neutral or singly ionized Xe atoms in the energy region of 8.4-10.7 eV. The photon flux of the strongest Xe I resonance line at 8.437 eV is comparable to that of the He Ialpha line (21.218 eV) from the He-ECR discharge lamp. Stable operation for more than 300 h is achieved by efficient air-cooling of a ceramic tube in the resonance cavity. The high bulk sensitivity and high-energy resolution of PES using the Xe lines are demonstrated for some typical materials.

  1. Development of high sensitivity and high speed large size blank inspection system LBIS

    Science.gov (United States)

    Ohara, Shinobu; Yoshida, Akinori; Hirai, Mitsuo; Kato, Takenori; Moriizumi, Koichi; Kusunose, Haruhiko

    2017-07-01

    The production of high-resolution flat panel displays (FPDs) for mobile phones today requires the use of high-quality large-size photomasks (LSPMs). Organic light emitting diode (OLED) displays use several transistors on each pixel for precise current control and, as such, the mask patterns for OLED displays are denser and finer than the patterns for the previous generation displays throughout the entire mask surface. It is therefore strongly demanded that mask patterns be produced with high fidelity and free of defect. To enable the production of a high quality LSPM in a short lead time, the manufacturers need a high-sensitivity high-speed mask blank inspection system that meets the requirement of advanced LSPMs. Lasertec has developed a large-size blank inspection system called LBIS, which achieves high sensitivity based on a laser-scattering technique. LBIS employs a high power laser as its inspection light source. LBIS's delivery optics, including a scanner and F-Theta scan lens, focus the light from the source linearly on the surface of the blank. Its specially-designed optics collect the light scattered by particles and defects generated during the manufacturing process, such as scratches, on the surface and guide it to photo multiplier tubes (PMTs) with high efficiency. Multiple PMTs are used on LBIS for the stable detection of scattered light, which may be distributed at various angles due to irregular shapes of defects. LBIS captures 0.3mμ PSL at a detection rate of over 99.5% with uniform sensitivity. Its inspection time is 20 minutes for a G8 blank and 35 minutes for G10. The differential interference contrast (DIC) microscope on the inspection head of LBIS captures high-contrast review images after inspection. The images are classified automatically.

  2. High-sensitivity Raman spectrometer to study pristine and irradiated interstellar ice analogs.

    Science.gov (United States)

    Bennett, Chris J; Brotton, Stephen J; Jones, Brant M; Misra, Anupam K; Sharma, Shiv K; Kaiser, Ralf I

    2013-06-18

    We discuss the novel design of a sensitive, normal-Raman spectrometer interfaced to an ultra-high vacuum chamber (5 × 10(-11) Torr) utilized to investigate the interaction of ionizing radiation with low temperature ices relevant to the solar system and interstellar medium. The design is based on a pulsed Nd:YAG laser which takes advantage of gating techniques to isolate the scattered Raman signal from the competing fluorescence signal. The setup incorporates innovations to achieve maximum sensitivity without detectable heating of the sample. Thin films of carbon dioxide (CO2) ices of 10 to 396 nm thickness were prepared and characterized using both Fourier transform infrared (FT-IR) spectroscopy and HeNe interference techniques. The ν+ and ν- Fermi resonance bands of CO2 ices were observed by Raman spectroscopy at 1385 and 1278 cm(-1), respectively, and the band areas showed a linear dependence on ice thickness. Preliminary irradiation experiments are conducted on a 450 nm thick sample of CO2 ice using energetic electrons. Both carbon monoxide (CO) and the infrared inactive molecular oxygen (O2) products are readily detected from their characteristic Raman bands at 2145 and 1545 cm(-1), respectively. Detection limits of 4 ± 3 and 6 ± 4 monolayers of CO and O2 were derived, demonstrating the unique power to detect newly formed molecules in irradiated ices in situ. The setup is universally applicable to the detection of low-abundance species, since no Raman signal enhancement is required, demonstrating Raman spectroscopy as a reliable alternative, or complement, to FT-IR spectroscopy in space science applications.

  3. High Performance Molecular Visualization: In-Situ and Parallel Rendering with EGL

    Science.gov (United States)

    Stone, John E.; Messmer, Peter; Sisneros, Robert; Schulten, Klaus

    2016-01-01

    Large scale molecular dynamics simulations produce terabytes of data that is impractical to transfer to remote facilities. It is therefore necessary to perform visualization tasks in-situ as the data are generated, or by running interactive remote visualization sessions and batch analyses co-located with direct access to high performance storage systems. A significant challenge for deploying visualization software within clouds, clusters, and supercomputers involves the operating system software required to initialize and manage graphics acceleration hardware. Recently, it has become possible for applications to use the Embedded-system Graphics Library (EGL) to eliminate the requirement for windowing system software on compute nodes, thereby eliminating a significant obstacle to broader use of high performance visualization applications. We outline the potential benefits of this approach in the context of visualization applications used in the cloud, on commodity clusters, and supercomputers. We discuss the implementation of EGL support in VMD, a widely used molecular visualization application, and we outline benefits of the approach for molecular visualization tasks on petascale computers, clouds, and remote visualization servers. We then provide a brief evaluation of the use of EGL in VMD, with tests using developmental graphics drivers on conventional workstations and on Amazon EC2 G2 GPU-accelerated cloud instance types. We expect that the techniques described here will be of broad benefit to many other visualization applications. PMID:27747137

  4. In-situ high-temperature Raman spectroscopic studies of aluminosilicate liquids

    Science.gov (United States)

    Daniel, Isabelle; Gillet, Philippe; Poe, Brent T.; McMillan, Paul F.

    1995-03-01

    We have measured in-situ Raman spectra of aluminosilicate glasses and liquids with albite (NaAlSi3 O8) and anorthite (CaAl2Si2O8) compositions at high temperatures, through their glass transition range up to 1700 and 2000 K, respectively. For these experiments, we have used a wire-loop heating device coupled with micro-Raman spectroscopy, in order to achieve effective spatial filtering of the extraneous thermal radiation. A major concern in this work is the development of methodology for reliably extracting the first and second order contributions to the Raman scattering spectra of aluminosilicate glasses and liquids from the high temperature experimental data, and analyzing these in terms of vibrational (anharmonic) and configurational changes. The changes in the first order Raman spectra with temperature are subtle. The principal low frequency band remains nearly constant with increasing temperature, indicating little change in the T-O-T angle, and that the angle bending vibration is quite harmonic. This is in contrast to vitreous SiO2, studied previously. Above Tg, intensity changes in the 560 590 cm-1 regions of both sets of spectra indicate configurational changes in the supercooled liquids, associated with formation of additional Al-O-Al linkages, or 3-membered (Al, Si)-containing rings. Additional intensity at 800 cm-1 reflects also some rearrangement of the Si-O-Al network.

  5. High in situ repeatability of behaviour indicates animal personality in the beadlet anemone Actinia equina (Cnidaria.

    Directory of Open Access Journals (Sweden)

    Mark Briffa

    Full Text Available 'Animal personality' means that individuals differ from one another in either single behaviours or suites of related behaviours in a way that is consistent over time. It is usually assumed that such consistent individual differences in behaviour are driven by variation in how individuals respond to information about their environment, rather than by differences in external factors such as variation in microhabitat. Since behavioural variation is ubiquitous in nature we might expect 'animal personality' to be present in diverse taxa, including animals with relatively simple nervous systems. We investigated in situ startle responses in a sea anemone, Actinia equina, to determine whether personalities might be present in this example of an animal with a simple nervous system. We found very high levels of repeatability among individuals that were re-identified in the same locations over a three week sampling period. In a subset of the data, where we used tide-pool temperature measurements to control for a key element of variation in microhabitat, these high levels of repeatability remained. Although a range of other consistent differences in micro-habitat features could have contributed to consistent differences between the behaviour of individuals, these data suggest the presence of animal personality in A. equina. Rather than being restricted to certain groups, personality may be a general feature of animals and may be particularly pronounced in species with simple nervous systems.

  6. In situ structural analysis of calcium aluminosilicate glasses under high pressure.

    Science.gov (United States)

    Muniz, R F; de Ligny, D; Martinet, C; Sandrini, M; Medina, A N; Rohling, J H; Baesso, M L; Lima, S M; Andrade, L H C; Guyot, Y

    2016-08-10

    In situ micro-Raman spectroscopy was used to investigate the structural evolution of OH(-)-free calcium aluminosilicate glasses, under high pressure and at room temperature. Evaluation was made of the role of the SiO2 concentration in percalcic join systems, for Al/(Al  +  Si) in the approximate range from 0.9 to 0.2. Under high pressure, the intensity of the main band related to the bending mode of bridging oxygen ([Formula: see text][T-O-T], where T  =  Si or Al) decreased gradually, suggesting that the bonds were severely altered or even destroyed. In Si-rich glasses, compression induced a transformation of Q (n) species to Q (n-1). In the case of Al-rich glass, the Al in the smallest Q (n) units evolved from tetrahedral to higher-coordinated Al (([5])Al and ([6])Al). Permanent structural changes were observed in samples recovered from the highest pressure of around 15 GPa and, particularly for Si-rich samples, the recovered structure showed an increase of three-membered rings in the Si/Al tetrahedral network.

  7. In-situ Fluorometers Reveal High Frequency Dynamics In Dissolved Organic Matter For Urban Rivers

    Science.gov (United States)

    Croghan, D.; Bradley, C.; Khamis, K.; Hannah, D. M.; Sadler, J. P.; Van Loon, A.

    2017-12-01

    To-date Dissolved Organic Matter (DOM) dynamics have been quantified poorly in urban rivers, despite the substantial water quality issues linked to urbanisation. Research has been hindered by the low temporal resolution of observations and over-reliance on manual sampling which often fail to capture precipitation events and diurnal dynamics. High frequency data are essential to estimate more accurately DOM fluxes/loads and to understand DOM furnishing and transport processes. Recent advances in optical sensor technology, including field deployable in-situ fluorometers, are yielding new high resolution DOM information. However, no consensus regarding the monitoring resolution required for urban systems exists, with no studies monitoring at lower temporal resolution monitoring. High temporal variation occurs during storm events in TLF and HLF intensity: TLF intensity is highest during the rising limb of the hydrograph and can rapidly decline thereafter, indicating the importance of fast flow-path and close proximity sources to TLF dynamics. HLF intensity tracks discharge more closely, but can also quickly decline during high flow events due to dilution effects. Furthermore, the ratio of TLF:HLF when derived at high-frequency provides a useful indication of the presence and type of organic effluents in stream, which aids in the identification of Combined Sewage Overflow releases. Our work highlights the need for future studies to utilise shorter temporal scales than previously used to monitor urban DOM dynamics. The application of higher frequency monitoring enables the identification of finer-scale patterns and subsequently aids in deciphering the sources and pathways controlling urban DOM dynamics.

  8. Model dependence of isospin sensitive observables at high densities

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Wen-Mei [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); School of Science, Huzhou Teachers College, Huzhou 313000 (China); Yong, Gao-Chan, E-mail: yonggaochan@impcas.ac.cn [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); State Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, Beijing 100190 (China); Wang, Yongjia [School of Science, Huzhou Teachers College, Huzhou 313000 (China); School of Nuclear Science and Technology, Lanzhou University, Lanzhou 730000 (China); Li, Qingfeng [School of Science, Huzhou Teachers College, Huzhou 313000 (China); Zhang, Hongfei [School of Nuclear Science and Technology, Lanzhou University, Lanzhou 730000 (China); State Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, Beijing 100190 (China); Zuo, Wei [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); State Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, Beijing 100190 (China)

    2013-10-07

    Within two different frameworks of isospin-dependent transport model, i.e., Boltzmann–Uehling–Uhlenbeck (IBUU04) and Ultrarelativistic Quantum Molecular Dynamics (UrQMD) transport models, sensitive probes of nuclear symmetry energy are simulated and compared. It is shown that neutron to proton ratio of free nucleons, π{sup −}/π{sup +} ratio as well as isospin-sensitive transverse and elliptic flows given by the two transport models with their “best settings”, all have obvious differences. Discrepancy of numerical value of isospin-sensitive n/p ratio of free nucleon from the two models mainly originates from different symmetry potentials used and discrepancies of numerical value of charged π{sup −}/π{sup +} ratio and isospin-sensitive flows mainly originate from different isospin-dependent nucleon–nucleon cross sections. These demonstrations call for more detailed studies on the model inputs (i.e., the density- and momentum-dependent symmetry potential and the isospin-dependent nucleon–nucleon cross section in medium) of isospin-dependent transport model used. The studies of model dependence of isospin sensitive observables can help nuclear physicists to pin down the density dependence of nuclear symmetry energy through comparison between experiments and theoretical simulations scientifically.

  9. An ion-sputtering gun to clean crystal surfaces in-situ in an ultra-high-vacuum electron microscope

    International Nuclear Information System (INIS)

    Morita, Etsuo; Takayanagi, Kunio; Kobayashi, Kunio; Yagi, Katsumichi; Honjo, Goro

    1980-01-01

    The design and performance of an ion-sputtering gun for cleaning crystal surfaces in-situ in an ultra-high-vacuum electron microscope are reported. The electron microscopic aspects of ion-bombardment damage to ionic magnesium oxide, covalent germanium and silicon, and metallic gold and copper crystals, and the effects of annealing after and during sputtering are described. The growth of various kinds of films deposited in-situ on crystals cleaned by ion-sputtering are described and discussed. (author)

  10. Realism in paediatric emergency simulations: A prospective comparison of in situ, low fidelity and centre-based, high fidelity scenarios.

    Science.gov (United States)

    O'Leary, Fenton; Pegiazoglou, Ioannis; McGarvey, Kathryn; Novakov, Ruza; Wolfsberger, Ingrid; Peat, Jennifer

    2018-02-01

    To measure scenario participant and faculty self-reported realism, engagement and learning for the low fidelity, in situ simulations and compare this to high fidelity, centre-based simulations. A prospective survey of scenario participants and faculty completing in situ and centre-based paediatric simulations. There were 382 responses, 276 from scenario participants and 106 from faculty with 241 responses from in situ and 141 from centre-based simulations. Scenario participant responses showed significantly higher ratings for the centre-based simulations for respiratory rate (P = 0.007), pulse (P = 0.036), breath sounds (P = 0.002), heart sounds (P realism for engagement and learning. © 2017 The Authors Emergency Medicine Australasia published by John Wiley & Sons Australia, Ltd on behalf of Australasian College for Emergency Medicine and Australasian Society for Emergency Medicine.

  11. Stress sensitivity and resilience in the chronic mild stress rat model of depression; an in situ hybridization study

    DEFF Research Database (Denmark)

    Bergström, A; Jayatissa, M N; Mørk, A

    2008-01-01

    in stress. Moreover, in the CA3 we found downregulation of vascular endothelial growth factor (VEGF) mRNA in the CMS sensitive group. Downregulation of VEGF suggests impaired hippocampal function, caused by loss of trophic factor neuroprotective support, as part of a previously uncharacterized mechanism...... for development of anhedonia. CMS induced anhedonia was not related to mRNA expression differences of the dopamine receptors D(1) and D(2), enkephalin, dynorphin, the NMDA receptor subtype NR2B in the ventral striatum, BDNF expression in the dentate gyrus, nor corticotrophin releasing hormone (CRH) and arginine...

  12. High contrast sensitivity for visually guided flight control in bumblebees.

    Science.gov (United States)

    Chakravarthi, Aravin; Kelber, Almut; Baird, Emily; Dacke, Marie

    2017-12-01

    Many insects rely on vision to find food, to return to their nest and to carefully control their flight between these two locations. The amount of information available to support these tasks is, in part, dictated by the spatial resolution and contrast sensitivity of their visual systems. Here, we investigate the absolute limits of these visual properties for visually guided position and speed control in Bombus terrestris. Our results indicate that the limit of spatial vision in the translational motion detection system of B. terrestris lies at 0.21 cycles deg -1 with a peak contrast sensitivity of at least 33. In the perspective of earlier findings, these results indicate that bumblebees have higher contrast sensitivity in the motion detection system underlying position control than in their object discrimination system. This suggests that bumblebees, and most likely also other insects, have different visual thresholds depending on the behavioral context.

  13. Effect of In-situ Cure on Measurement of Glass Transition Temperatures in High-temperature Thermosetting Polymers

    Science.gov (United States)

    2015-01-01

    TEMPERATURES IN HIGH-TEMPERATURE THERMOSETTING POLYMERS 5a. CONTRACT NUMBER In-House 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S...illustrated the difficulties inherent in measurement of the glass transition temperature of this high-temperature thermosetting polymer via dynamic...copyright protection in the United States. EFFECT OF IN-SITU CURE ON MEASUREMENT OF GLASS TRANSITION TEMPERATURES IN HIGH-TEMPERATURE THERMOSETTING

  14. Metal ion-organic compound for high sensitive ESR dosimetry

    International Nuclear Information System (INIS)

    Hassan, G.M.; Ikeya, Motoji

    2000-01-01

    A systematic study to find a tissue equivalent and high sensitive dosimeter material has been made to stimulate the field of ESR dosimetry. Lithium acetate dihydrate (Li-Ac·2H 2 O:CH 3 COOLi·2H 2 O) and lithium phosphate (Li-phosphate:Li 3 PO 4 ) were irradiated by γ-rays to study radicals with (ESR) in addition to magnesium lactate (Mg-lactate (CH 3 CH(OH)COO) 2 Mg) doped with nominal pure lithium lactate (Mg(Li)-lactate) and lithium lactate (CH 3 CH(OH)COOLi) doped with Mg-lactate (Li(Mg)-lactate). A triplet spectrum with intensity ratio of 1:2:1 in Li-Ac·2H 2 O was ascribed to acetate radical which has g=2.0031±0.0004 and hyperfine splitting of A/gβ=2.12±0.1 mT. The Li-phosphate spectrum shows splitting due to anisotropic g-factors of g par =2.0190±0.0005 and g perp =1.9974±0.0004. Quartet spectra with the intensity ratio of 1:3:3:1 in Mg(Li)-lactate and Li(Mg)-lactate were ascribed to lactate radicals with g-factors of 2.0032 ± 0.0004 and 2.0029 ± 0.0004 and the intensity ratio of 1:3:3:1 and A/gβ=1.92±0.06 and 1.82 ± 0.06 mT, respectively. The response to γ-ray dose and the thermal stability as well as the effect of UV-illumination have been studied. The obtained number of free radicals per 100 eV (G-values) were 0.4 ± 0.13, 1.02 ± 0.31, 1.35 ± 0.35 and 0.78 ± 0 for Li-Ac.2H 2 O, Li-phosphate, Mg(Li)-lactate, and Li(Mg)-lactate, respectively. The lifetimes were estimated from Arrhenius plots to be approximately 2.0 ± 0.6, 50.7 ± 20 and 10 ± 3.5 years for Li-phosphate, Mg(Li)-lactate and Li(Mg)-lactate, respectively. The lifetime for Li-Ac·2H 2 O cannot be estimated because of the decomposition by heating

  15. Development of High Temperature/High Sensitivity Novel Chemical Resistive Sensor

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Chunrui [Univ. of Texas, San Antonio, TX (United States); Enriquez, Erik [Univ. of Texas, San Antonio, TX (United States); Wang, Haibing [Univ. of Texas, San Antonio, TX (United States); Xu, Xing [Univ. of Texas, San Antonio, TX (United States); Bao, Shangyong [Univ. of Texas, San Antonio, TX (United States); Collins, Gregory [Univ. of Texas, San Antonio, TX (United States)

    2013-08-13

    The research has been focused to design, fabricate, and develop high temperature/high sensitivity novel multifunctional chemical sensors for the selective detection of fossil energy gases used in power and fuel systems. By systematically studying the physical properties of the LnBaCo2O5+d (LBCO) [Ln=Pr or La] thin-films, a new concept chemical sensor based high temperature chemical resistant change has been developed for the application for the next generation highly efficient and near zero emission power generation technologies. We also discovered that the superfast chemical dynamic behavior and an ultrafast surface exchange kinetics in the highly epitaxial LBCO thin films. Furthermore, our research indicates that hydrogen can superfast diffuse in the ordered oxygen vacancy structures in the highly epitaxial LBCO thin films, which suggest that the LBCO thin film not only can be an excellent candidate for the fabrication of high temperature ultra sensitive chemical sensors and control systems for power and fuel monitoring systems, but also can be an excellent candidate for the low temperature solid oxide fuel cell anode and cathode materials.

  16. High-speed high-sensitivity infrared spectroscopy using mid-infrared swept lasers (Conference Presentation)

    Science.gov (United States)

    Childs, David T. D.; Groom, Kristian M.; Hogg, Richard A.; Revin, Dmitry G.; Cockburn, John W.; Rehman, Ihtesham U.; Matcher, Stephen J.

    2016-03-01

    Infrared spectroscopy is a highly attractive read-out technology for compositional analysis of biomedical specimens because of its unique combination of high molecular sensitivity without the need for exogenous labels. Traditional techniques such as FTIR and Raman have suffered from comparatively low speed and sensitivity however recent innovations are challenging this situation. Direct mid-IR spectroscopy is being speeded up by innovations such as MEMS-based FTIR instruments with very high mirror speeds and supercontinuum sources producing very high sample irradiation levels. Here we explore another possible method - external cavity quantum cascade lasers (EC-QCL's) with high cavity tuning speeds (mid-IR swept lasers). Swept lasers have been heavily developed in the near-infrared where they are used for non-destructive low-coherence imaging (OCT). We adapt these concepts in two ways. Firstly by combining mid-IR quantum cascade gain chips with external cavity designs adapted from OCT we achieve spectral acquisition rates approaching 1 kHz and demonstrate potential to reach 100 kHz. Secondly we show that mid-IR swept lasers share a fundamental sensitivity advantage with near-IR OCT swept lasers. This makes them potentially able to achieve the same spectral SNR as an FTIR instrument in a time x N shorter (N being the number of spectral points) under otherwise matched conditions. This effect is demonstrated using measurements of a PDMS sample. The combination of potentially very high spectral acquisition rates, fundamental SNR advantage and the use of low-cost detector systems could make mid-IR swept lasers a powerful technology for high-throughput biomedical spectroscopy.

  17. Application of in situ diffraction in high-throughput structure determination platforms.

    Science.gov (United States)

    Aller, Pierre; Sanchez-Weatherby, Juan; Foadi, James; Winter, Graeme; Lobley, Carina M C; Axford, Danny; Ashton, Alun W; Bellini, Domenico; Brandao-Neto, Jose; Culurgioni, Simone; Douangamath, Alice; Duman, Ramona; Evans, Gwyndaf; Fisher, Stuart; Flaig, Ralf; Hall, David R; Lukacik, Petra; Mazzorana, Marco; McAuley, Katherine E; Mykhaylyk, Vitaliy; Owen, Robin L; Paterson, Neil G; Romano, Pierpaolo; Sandy, James; Sorensen, Thomas; von Delft, Frank; Wagner, Armin; Warren, Anna; Williams, Mark; Stuart, David I; Walsh, Martin A

    2015-01-01

    Macromolecular crystallography (MX) is the most powerful technique available to structural biologists to visualize in atomic detail the macromolecular machinery of the cell. Since the emergence of structural genomics initiatives, significant advances have been made in all key steps of the structure determination process. In particular, third-generation synchrotron sources and the application of highly automated approaches to data acquisition and analysis at these facilities have been the major factors in the rate of increase of macromolecular structures determined annually. A plethora of tools are now available to users of synchrotron beamlines to enable rapid and efficient evaluation of samples, collection of the best data, and in favorable cases structure solution in near real time. Here, we provide a short overview of the emerging use of collecting X-ray diffraction data directly from the crystallization experiment. These in situ experiments are now routinely available to users at a number of synchrotron MX beamlines. A practical guide to the use of the method on the MX suite of beamlines at Diamond Light Source is given.

  18. In situ study starch gelatinization under ultra-high hydrostatic pressure using synchrotron SAXS

    KAUST Repository

    Yang, Zhi

    2015-12-13

    The gelatinization of waxy (very low amylose) corn and potato starches by high hydrostatic pressure (HHP) (up to ∼1 GPa) was investigated in situ using synchrotron small-angle X-ray scattering (SAXS) on samples held in a diamond anvil cell (DAC). The starch pastes, made by mixing starch and water in a 1:1 ratio (by weight), were pressurized and measured at room temperature. During HHP, both SAXS peak areas (corresponding to the lamellar phase) of waxy corn and potato starches decreased suggesting the starch gelatinization increases with increasing pressure. As pressure increased, lamellar peak broadened and the power law exponent increased in low q region. 1D linear correlation function was further employed to analyse SAXS data. For both waxy potato and waxy corn starches, the long period length and the average thickness of amorphous layers decreased when the pressure increased. While for both of waxy starches, the thickness of the crystalline layer first increased, then decreased when the pressure increased. The former is probably due to the out-phasing of starch molecules, and the latter is due to the water penetrating into the crystalline region during gelatinization and to pressure induced compression.

  19. Ni3Si2 nanowires grown in situ on Ni foam for high-performance supercapacitors

    Science.gov (United States)

    Jiang, Yizhe; Li, Zhihui; Li, Beibei; Zhang, Jinying; Niu, Chunming

    2016-07-01

    Ni3Si2 nanowires and nanoawls have grown in situ on the surface of Ni foams by a controlled low pressure chemical vapor deposition process. Structural characterization shows that the individual Ni3Si2 nanowire is single crystal covered with a thin layer (1-2 nm) of SiO2 with a diameter of ∼20-30 nm and length of ten's micrometers. Individual nanoawl with a circular cone shape is polycrystalline. Both Ni3Si2 nanowire and nanoawl samples are evaluated as potential electrode materials for supercapacitors. The nanowire electrode delivers a very high specific capacitance and excellent rate capability. A specific capacitance of 760 F g-1 is measured at current density of 0.5 A g-1, which decreases to 518 F g-1 when the current density increases to 10 A g-1. The capacitance is dominated by pseudocapacitance with a mechanism similar to that of NiO or Ni(OH)2 widely studied in the literature. An asymmetric supercapacitor fabricated by pairing Ni3Si2 nanowire electrode with an activated carbon electrode exhibits energy densities of 17.5 Wh kg-1 and 8.8 Wh kg-1 at power densites of 301 W kg-1 and 3000 W kg-1.

  20. High resolution in situ zymography reveals matrix metalloproteinase activity at glutamatergic synapses.

    Science.gov (United States)

    Gawlak, M; Górkiewicz, T; Gorlewicz, A; Konopacki, F A; Kaczmarek, L; Wilczynski, G M

    2009-01-12

    Synaptic plasticity involves remodeling of extracellular matrix. This is mediated, in part, by enzymes of the matrix metalloproteinase (MMP) family, in particular by gelatinase MMP-9. Accordingly, there is a need of developing methods to visualize gelatinolytic activity at the level of individual synapses, especially in the context of neurotransmitters receptors. Here we present a high-resolution fluorescent in situ zymography (ISZ), performed in thin sections of the alcohol-fixed and polyester wax-embedded brain tissue of the rat (Rattus norvegicus), which is superior to the current ISZ protocols. The method allows visualization of structural details up to the resolution-limit of light microscopy, in conjunction with immunofluorescent labeling. We used this technique to visualize and quantify gelatinolytic activity at the synapses in control and seizure-affected rat brain. In particular, we demonstrated, for the first time, frequent colocalization of gelatinase(s) with synaptic N-methyl-D-aspartic acid (NMDA)- and AMPA-type glutamate receptors. We believe that our method represents a valuable tool to study extracellular proteolytic processes at the synapses, it could be used, as well, to investigate proteinase involvement in a range of physiological and pathological phenomena in the nervous system.

  1. In situ measurement of low-Z material coating thickness on high Z substrate for tokamaks

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, D., E-mail: dmueller@pppl.gov; Roquemore, A. L.; Jaworski, M.; Skinner, C. H.; Miller, J.; Creely, A. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States); Raman, P.; Ruzic, D. [Department of Nuclear, Plasma, and Radiological Engineering, Center for Plasma Material Interaction, University of Illinois, Urbana, Illinois 61801 (United States)

    2014-11-15

    Rutherford backscattering of energetic particles can be used to determine the thickness of a coating of a low-Z material over a heavier substrate. Simulations indicate that 5 MeV alpha particles from an {sup 241}Am source can be used to measure the thickness of a Li coating on Mo tiles between 0.5 and 15 μm thick. Using a 0.1 mCi source, a thickness measurement can be accomplished in 2 h of counting. This technique could be used to measure any thin, low-Z material coating (up to 1 mg/cm{sup 2} thick) on a high-Z substrate, such as Be on W, B on Mo, or Li on Mo. By inserting a source and detector on a moveable probe, this technique could be used to provide an in situ measurement of the thickness of Li coating on NSTX-U Mo tiles. A test stand with an alpha source and an annular solid-state detector was used to investigate the measurable range of low-Z material thicknesses on Mo tiles.

  2. In-situ high-resolution gamma-spectrometric survey of burial ground-monitoring wells

    International Nuclear Information System (INIS)

    Bowman, W.W.

    1981-09-01

    In situ high resolution gamma-ray spectrometry with an intrinsic germanium detector assembly of special design surveyed the burial ground monitoring wells to locate and identify gamma emitters that may have migrated from the burial trenches toward the water table. Gamma-ray spectra were acquired as a function of depth in each well and recorded on magnetic tape. These spectra were reduced by a series of computer programs to produce count rate versus depth profiles for natural and man-made activities. The original spectra and the profiles have been archived on magnetic tape for comparison with similar future surveys. Large amounts of man-made activities were observed in some of the burial trenches; however, below the trench bottoms, only very low but detectable amounts of 60 Co and 137 Cs were observed in eleven wells. The highest level of man-made gamma activity observed below the trench bottoms has a count rate roughly equal to that observed for uranium daughter activities which are natural to the subsoil

  3. In-situ testing of high efficiency filters at AEE Winfrith

    International Nuclear Information System (INIS)

    Fraser, D.C.

    1977-10-01

    This paper discusses experience in the testing of high efficiency filters in a variety of reactor and plant installations at AEE Winfrith. There is rarely any concern about the effectiveness of the filter as supplied by any reputable manufacturer. Experience has shown there is a need to check for defects in the installation of filters which could lead to by-passing of aerosols and it is desirable to perform periodical re-tests to ensure that no subsequent deterioration occurs. It is important to use simple, portable apparatus for such tests; methods based on the use of sodium chloride aerosols, although suitable for the testing of filters prior to installation, involve apparatus which is too bulky for in-situ testing. At Winfrith a double automatic Pollak counter has been developed and used routinely since 1970. The aerosol involved has a particle size far smaller than the size most likely to penetrate intact filters, but this is irrelevant when one is primarily interested in particles which by-pass the filter. Comparisons with other methods of testing filters will be described. There is remarkably good agreement between the efficiency of the filter installation as measured by a Pollak counter compared with techniques involving aerosols of sodium chloride and di octyl phthalate (DOP), presumably because the leakage around the filter is independent of particle size. (author)

  4. INTACS before or after laser in situ keratomileusis: correction of thin corneas with moderately high myopia.

    Science.gov (United States)

    Ito, Mitsutoshi; Arai, Hiroyuki; Fukumoto, Teruki; Toda, Ikuko; Tsubota, Kazuo

    2004-01-01

    Intrastromal corneal ring segments (INTACS Micro-Thin Prescription Inserts by Addition Technologies, Fremont, Calif) were inserted as a combined surgery with laser in situ keratomileusis (LASIK) in six eyes with thin corneas to correct moderately high myopia. INTACS were implanted before LASIK (INTACS-LASIK) in three eyes and after LASIK (LASIK-INTACS) in three eyes. Mean preoperative manifest spherical equivalent refraction was -7.88 diopters. Mean follow-up was 306 days. No intraoperative complications occurred. The LASIK-INTACS eyes were slightly more overcorrected than the INTACS-LASIK eyes because of the enhanced performance of INTACS in the thinned corneal tissue. Induced astigmatism by INTACS per se was less in the LASIK-INTACS eyes than in the INTACS-LASIK eyes. At last examination, uncorrected visual acuity was better than 20/25 in all eyes. Best spectacle-corrected visual acuity was within 1 line of the preoperative value in all eyes. Both methods resulted in significant improvement in visual acuity and refraction. Based on our limited experience, however, LASIK followed by INTACS is preferred for reasons of safety, convenience, and lower induced cylinder.

  5. Models for Strength Prediction of High-Porosity Cast-In-Situ Foamed Concrete

    Directory of Open Access Journals (Sweden)

    Wenhui Zhao

    2018-01-01

    Full Text Available A study was undertaken to develop a prediction model of compressive strength for three types of high-porosity cast-in-situ foamed concrete (cement mix, cement-fly ash mix, and cement-sand mix with dry densities of less than 700 kg/m3. The model is an extension of Balshin’s model and takes into account the hydration ratio of the raw materials, in which the water/cement ratio was a constant for the entire construction period for a certain casting density. The results show that the measured porosity is slightly lower than the theoretical porosity due to few inaccessible pores. The compressive strength increases exponentially with the increase in the ratio of the dry density to the solid density and increases with the curing time following the composite function A2ln⁡tB2 for all three types of foamed concrete. Based on the results that the compressive strength changes with the porosity and the curing time, a prediction model taking into account the mix constitution, curing time, and porosity is developed. A simple prediction model is put forward when no experimental data are available.

  6. High-throughput screening for cellobiose dehydrogenases by Prussian Blue in situ formation.

    Science.gov (United States)

    Vasilchenko, Liliya G; Ludwig, Roland; Yershevich, Olga P; Haltrich, Dietmar; Rabinovich, Mikhail L

    2012-07-01

    Extracellular fungal flavocytochrome cellobiose dehydrogenase (CDH) is a promising enzyme for both bioelectronics and lignocellulose bioconversion. A selective high-throughput screening assay for CDH in the presence of various fungal oxidoreductases was developed. It is based on Prussian Blue (PB) in situ formation in the presence of cellobiose (<0.25 mM), ferric acetate, and ferricyanide. CDH induces PB formation via both reduction of ferricyanide to ferrocyanide reacting with an excess of Fe³⁺ (pathway 1) and reduction of ferric ions to Fe²⁺ reacting with the excess of ferricyanide (pathway 2). Basidiomycetous and ascomycetous CDH formed PB optimally at pH 3.5 and 4.5, respectively. In contrast to the holoenzyme CDH, its FAD-containing dehydrogenase domain lacking the cytochrome domain formed PB only via pathway 1 and was less active than the parent enzyme. The assay can be applied on active growing cultures on agar plates or on fungal culture supernatants in 96-well plates under aerobic conditions. Neither other carbohydrate oxidoreductases (pyranose dehydrogenase, FAD-dependent glucose dehydrogenase, glucose oxidase) nor laccase interfered with CDH activity in this assay. Applicability of the developed assay for the selection of new ascomycetous CDH producers as well as possibility of the controlled synthesis of new PB nanocomposites by CDH are discussed. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. In Situ Acoustic Monitoring of Thermal Spray Process Using High-Frequency Impulse Measurements

    Science.gov (United States)

    Tillmann, Wolfgang; Walther, Frank; Luo, Weifeng; Haack, Matthias; Nellesen, Jens; Knyazeva, Marina

    2018-01-01

    In order to guarantee their protective function, thermal spray coatings must be free from cracks, which expose the substrate surface to, e.g., corrosive media. Cracks in thermal spray coatings are usually formed because of tensile residual stresses. Most commonly, the crack occurrence is determined after the thermal spraying process by examination of metallographic cross sections of the coating. Recent efforts focus on in situ monitoring of crack formation by means of acoustic emission analysis. However, the acoustic signals related to crack propagation can be absorbed by the noise of the thermal spraying process. In this work, a high-frequency impulse measurement technique was applied to separate different acoustic sources by visualizing the characteristic signal of crack formation via quasi-real-time Fourier analysis. The investigations were carried out on a twin wire arc spraying process, utilizing FeCrBSi as a coating material. The impact of the process parameters on the acoustic emission spectrum was studied. Acoustic emission analysis enables to obtain global and integral information on the formed cracks. The coating morphology and coating defects were inspected using light microscopy on metallographic cross sections. Additionally, the resulting crack patterns were imaged in 3D by means of x-ray microtomography.

  8. In-situ high resolution particle sampling by large time sequence inertial spectrometry

    International Nuclear Information System (INIS)

    Prodi, V.; Belosi, F.

    1990-09-01

    In situ sampling is always preferred, when possible, because of the artifacts that can arise when the aerosol has to flow through long sampling lines. On the other hand, the amount of possible losses can be calculated with some confidence only when the size distribution can be measured with a sufficient precision and the losses are not too large. This makes it desirable to sample directly in the vicinity of the aerosol source or containment. High temperature sampling devices with a detailed aerodynamic separation are extremely useful to this purpose. Several measurements are possible with the inertial spectrometer (INSPEC), but not with cascade impactors or cyclones. INSPEC - INertial SPECtrometer - has been conceived to measure the size distribution of aerosols by separating the particles while airborne according to their size and collecting them on a filter. It consists of a channel of rectangular cross-section with a 90 degree bend. Clean air is drawn through the channel, with a thin aerosol sheath injected close to the inner wall. Due to the bend, the particles are separated according to their size, leaving the original streamline by a distance which is a function of particle inertia and resistance, i.e. of aerodynamic diameter. The filter collects all the particles of the same aerodynamic size at the same distance from the inlet, in a continuous distribution. INSPEC particle separation at high temperature (up to 800 C) has been tested with Zirconia particles as calibration aerosols. The feasibility study has been concerned with resolution and time sequence sampling capabilities under high temperature (700 C)

  9. The Pajarito Monitor: a high-sensitivity monitoring system for highly enriched uranium

    International Nuclear Information System (INIS)

    Fehlau, P.E.; Coop, K.; Garcia, C.; Martinez, J.

    1984-01-01

    The Pajarito Monitor for Special Nuclear Material is a high-sensitivity gamma-ray monitoring system for detecting small quantities of highly enriched uranium transported by pedestrians or motor vehicles. The monitor consists of two components: a walk-through personnel monitor and a vehicle monitor. The personnel monitor has a plastic-scintillator detector portal, a microwave occupancy monitor, and a microprocessor control unit that measures the radiation intensity during background and monitoring periods to detect transient diversion signals. The vehicle monitor examines stationary motor vehicles while the vehicle's occupants pass through the personnel portal to exchange their badges. The vehicle monitor has four groups of large plastic scintillators that scan the vehicle from above and below. Its microprocessor control unit measures separate radiation intensities in each detector group. Vehicle occupancy is sensed by a highway traffic detection system. Each monitor's controller is responsible for detecting diversion as well as serving as a calibration and trouble-shooting aid. Diversion signals are detected by a sequential probability ratio hypothesis test that minimizes the monitoring time in the vehicle monitor and adapts itself well to variations in individual passage speed in the personnel monitor. Designed to be highly sensitive to diverted enriched uranium, the monitoring system also exhibits exceptional sensitivity for plutonium

  10. An in situ vapour phase hydrothermal surface doping approach for fabrication of high performance Co3O4 electrocatalysts with an exceptionally high S-doped active surface.

    Science.gov (United States)

    Tan, Zhijin; Liu, Porun; Zhang, Haimin; Wang, Yun; Al-Mamun, Mohammad; Yang, Hua Gui; Wang, Dan; Tang, Zhiyong; Zhao, Huijun

    2015-04-04

    A facile in situ vapour phase hydrothermal (VPH) surface doping approach has been developed for fabrication of high performance S-doped Co3O4 electrocatalysts with an unprecedentedly high surface S content (>47%). The demonstrated VPH doping approach could be useful for enrichment of surface active sites for other metal oxide electrocatalysts.

  11. Sensitivity improvement for antimony determination by using in-situ atom trapping in a slotted quartz tube and flame atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Titretir, Serap, E-mail: serap.titretir@inonu.edu.tr [Department of Chemistry, Faculty of Arts and Sciences, Inoenue University, 44280 Malatya (Turkey); S Latin-Small-Letter-Dotless-I k, Ahmet Inanc [Department of Chemistry, Faculty of Arts and Sciences, Inoenue University, 44280 Malatya (Turkey); Arslan, Yasin [Department of Chemistry, Faculty of Arts and Sciences, Mehmet Akif Ersoy University, Istiklal Yerleskesi, 15030 Burdur (Turkey); Ataman, O. Yavuz [Department of Chemistry, Faculty of Arts and Sciences, Middle East Technical University, 06800 Ankara (Turkey)

    2012-11-15

    Significant improvement has been achieved for antimony determination using a slotted quartz tube (SQT) as an atom trap (AT) for in situ preconcentration and flame atomic absorption spectrometry (FAAS). The suggested technique consists of trapping analyte species during ordinary nebulization followed by releasing the collected analyte via introducing organic solvent. Procedures and analytical figures of merit have been presented for the techniques called FAAS, SQT-FAAS and finally SQT-AT-FAAS with the relevant comparisons. Analytical parameters, namely composition of the aqueous medium, sample flow rate, flame conditions, distance between burner head and SQT, sampling period and type of organic solvent and its volume have been optimized. Using SQT-AT-FAAS, a sensitivity enhancement of 369 fold has been obtained, 3 s limit of detection was 3.9 {mu}g L{sup -1} when 25.0 mL of sample was collected in 4.0 min. Interference effects of some elements on antimony signal were studied. - Highlights: Black-Right-Pointing-Pointer Atom trapping in a quartz tube was used for Sb with flame AAS. Black-Right-Pointing-Pointer An inexpensive, simple and sensitive analytical method was suggested for Sb. Black-Right-Pointing-Pointer Almost no background absorption was observed. Black-Right-Pointing-Pointer Range is in microgram per liter level.

  12. Sensitivity improvement for antimony determination by using in-situ atom trapping in a slotted quartz tube and flame atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Titretir, Serap; Şık, Ahmet İnanç; Arslan, Yasin; Ataman, O. Yavuz

    2012-01-01

    Significant improvement has been achieved for antimony determination using a slotted quartz tube (SQT) as an atom trap (AT) for in situ preconcentration and flame atomic absorption spectrometry (FAAS). The suggested technique consists of trapping analyte species during ordinary nebulization followed by releasing the collected analyte via introducing organic solvent. Procedures and analytical figures of merit have been presented for the techniques called FAAS, SQT-FAAS and finally SQT-AT-FAAS with the relevant comparisons. Analytical parameters, namely composition of the aqueous medium, sample flow rate, flame conditions, distance between burner head and SQT, sampling period and type of organic solvent and its volume have been optimized. Using SQT-AT-FAAS, a sensitivity enhancement of 369 fold has been obtained, 3 s limit of detection was 3.9 μg L −1 when 25.0 mL of sample was collected in 4.0 min. Interference effects of some elements on antimony signal were studied. - Highlights: ► Atom trapping in a quartz tube was used for Sb with flame AAS. ► An inexpensive, simple and sensitive analytical method was suggested for Sb. ► Almost no background absorption was observed. ► Range is in microgram per liter level.

  13. Desensitization protocol in highly HLA-sensitized and ABO-incompatible high titer kidney transplantation.

    Science.gov (United States)

    Uchida, J; Machida, Y; Iwai, T; Naganuma, T; Kitamoto, K; Iguchi, T; Maeda, S; Kamada, Y; Kuwabara, N; Kim, T; Nakatani, T

    2010-12-01

    A positive crossmatch indicates the presence of donor-specific alloantibodies and is associated with a graft loss rate of >80%; anti-ABO blood group antibodies develop in response to exposure to foreign blood groups, resulting in immediate graft loss. However, a desensitization protocol for highly HLA-sensitized and ABO-incompatible high-titer kidney transplantation has not yet been established. We treated 6 patients with high (≥1:512) anti-A/B antibody titers and 2 highly HLA-sensitized patients. Our immunosuppression protocol was initiated 1 month before surgery and included mycophenolate mofetil (1 g/d) and/or low-dose steroid (methylprednisolone 8 mg/d). Two doses of the anti-CD20 antibody rituximab (150 mg/m(2)) were administered 2 weeks before and on the day of transplantation. We performed antibody removal with 6-12 sessions of plasmapheresis (plasma exchange or double-filtration plasmapheresis) before transplantation. Splenectomy was also performed on the day of transplantation. Postoperative immunosuppression followed the same regimen as ABO-compatible cases, in which calcineurin inhibitors were initiated 3 days before transplantation, combined with 2 doses of basiliximab. Of the 8 patients, 7 subsequently underwent successful living-donor kidney transplantation. Follow-up of our recipients showed that the patient and graft survival rates were 100%. Acute cellular rejection and antibody-mediated rejection episodes occurred in 1 of the 7 recipients. These findings suggest that our immunosuppression regimen consisting of rituximab infusions, splenectomy, plasmapheresis, and pharmacologic immunosuppression may prove to be effective as a desensitization protocol for highly HLA-sensitized and ABO-incompatible high-titer kidney transplantation. Copyright © 2010 Elsevier Inc. All rights reserved.

  14. Simultaneous Determination of Food-Related Biogenic Amines and Precursor Amino Acids Using in Situ Derivatization Ultrasound-Assisted Dispersive Liquid-Liquid Microextraction by Ultra-High-Performance Liquid Chromatography Tandem Mass Spectrometry.

    Science.gov (United States)

    He, Yongrui; Zhao, Xian-En; Wang, Renjun; Wei, Na; Sun, Jing; Dang, Jun; Chen, Guang; Liu, Zhiqiang; Zhu, Shuyun; You, Jinmao

    2016-11-02

    A simple, rapid, sensitive, selective, and environmentally friendly method, based on in situ derivatization ultrasound-assisted dispersive liquid-liquid microextraction (in situ DUADLLME) coupled with ultra-high-performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) using multiple reaction monitoring (MRM) mode has been developed for the simultaneous determination of food-related biogenic amines and amino acids. A new mass-spectrometry-sensitive derivatization reagent 4'-carbonyl chloride rosamine (CCR) was designed, synthesized, and first reported. Parameters and conditions of in situ DUADLLME and UHPLC-MS/MS were optimized in detail. Under the optimized conditions, the in situ DUADLLME was completed speedily (within 1 min) with high derivatization efficiencies (≥98.5%). With the cleanup and concentration of microextraction step, good analytical performance was obtained for the analytes. The results showed that this method was accurate and practical for quantification of biogenic amines and amino acids in common food samples (red wine, beer, wine, cheese, sausage, and fish).

  15. Highly sensitive straightness measurement system using a ball-lens

    International Nuclear Information System (INIS)

    Lee, Minho; Yang, Hyun-Ik; Cho, Nahm-Gyoo

    2016-01-01

    In this paper, a new and simple optical technique to accurately measure the straightness errors of a linear stage is proposed. To improve the performance, including the measurement sensitivity and resolution of the measurement system, and to simultaneously measure two-dimensional straightness errors (2D straightness errors), an optical system was designed using a laser, a retro-reflector, a ball-lens, and a two-dimensional position sensitive detector (2D PSD). The characteristics of the measurement system were analytically and experimentally investigated. A prototype measurement system was manufactured based on the investigated results, and the performances of this system have been tested. The measuring performance of the system was easily improved by about 12 times using the proposed technique and it can be further improved. It is shown that the proposed technique can easily and effectively improve the performance of a conventional straightness measurement system based on the geometric optical method using a PSD. (paper)

  16. Highly Sensitive Cadmium Concentration Sensor Using Long Period Grating

    Directory of Open Access Journals (Sweden)

    A. S. Lalasangi

    2011-08-01

    Full Text Available In this paper we have proposed a simple and effective Long Period Grating chemical sensor for detecting the traces of Cadmium (Cd++ in drinking water at ppm level. Long Period gratings (LPG were fabricated by point-by-point technique with CO2 laser. We have characterized the LPG concentration sensor sensitivity for different solutions of Cd concentrations varying from 0.01 ppm to 0.04 ppm by injecting white Light source and observed transmitted spectra using Optical Spectrum Analyzer (OSA. Proper reagents have been used in the solutions for detection of the Cd species. The overall shift in wavelength is 10 nm when surrounding medium gradually changed from water to 0.04 ppm of cadmium concentrations. A comparative study has been done using sophisticated spectroscopic atomic absorption spectrometer (AAS and Inductively Coupled Plasma (ICP instruments. The spectral sensitivity enhancement was done by modifying grating surface with gold nanoparticles.

  17. Highly sensitive BTX detection using surface functionalized QCM sensor

    Energy Technology Data Exchange (ETDEWEB)

    Bozkurt, Asuman Aşıkoğlu; Özdemir, Okan; Altındal, Ahmet, E-mail: altindal@yildiz.edu.tr [Department of Physics, Yildiz Technical University, Davutpasa, 34210 Istanbul (Turkey)

    2016-03-25

    A novel organic compound was designed and successfully synthesized for the fabrication of QCM based sensors to detect the low concentrations of BTX gases in indoor air. The effect of the long-range electron orbital delocalization on the BTX vapour sensing properties of azo-bridged Pcs based chemiresistor-type sensors have also been investigated in this work. The sensing behaviour of the film for the online detection of volatile organic solvent vapors was investigated by utilizing an AT-cut quartz crystal resonator. It was observed that the adsorption of the target molecules on the coating surface cause a reversible negative frequency shift of the resonator. Thus, a variety of solvent vapors can be detected by using the phthalocyanine film as sensitive coating, with sensitivity in the ppm range and response times in the order of several seconds depending on the molecular structure of the organic solvent.

  18. Antibody Desensitization Therapy in Highly Sensitized Lung Transplant Candidates

    Science.gov (United States)

    Snyder, L. D.; Gray, A. L.; Reynolds, J. M.; Arepally, G. M.; Bedoya, A.; Hartwig, M. G.; Davis, R. D.; Lopes, K. E.; Wegner, W. E.; Chen, D. F.; Palmer, S. M.

    2015-01-01

    As HLAs antibody detection technology has evolved, there is now detailed HLA antibody information available on prospective transplant recipients. Determining single antigen antibody specificity allows for a calculated panel reactive antibodies (cPRA) value, providing an estimate of the effective donor pool. For broadly sensitized lung transplant candidates (cPRA ≥ 80%), our center adopted a pretransplant multimodal desensitization protocol in an effort to decrease the cPRA and expand the donor pool. This desensitization protocol included plasmapheresis, solumedrol, bortezomib and rituximab given in combination over 19 days followed by intravenous immunoglobulin. Eight of 18 candidates completed therapy with the primary reasons for early discontinuation being transplant (by avoiding unacceptable antigens) or thrombocytopenia. In a mixed-model analysis, there were no significant changes in PRA or cPRA changes over time with the protocol. A sub-analysis of the median fluorescence intensity (MFI) change indicated a small decline that was significant in antibodies with MFI 5000–10 000. Nine of 18 candidates subsequently had a transplant. Posttransplant survival in these nine recipients was comparable to other pretransplant-sensitized recipients who did not receive therapy. In summary, an aggressive multi-modal desensitization protocol does not significantly reduce pretransplant HLA antibodies in a broadly sensitized lung transplant candidate cohort. PMID:24666831

  19. Design and performance of an in situ high vacuum STM in beam line at 15 UD pelletron accelerator

    International Nuclear Information System (INIS)

    Singh, J.P.; Tripathi, A.; Ahuja, R.; Dutt, R.N.; Kanjilal, D.; Mehta, G.K.; Raychoudhuri, A.K.

    2000-01-01

    The design, installation and performance of an in situ high vacuum STM in the materials science beam line of 15 UD tandem Pelletron accelerator, NSC are reported. The scanning tunneling microscope (STM) has imaged highly oriented pyrolytic graphite (HOPG) surfaces with atomic resolution. Local current-voltage spectroscopy has also been performed on p-type Si (111) samples. A band gap of 1.09 ± 0.1 eV was calculated. (author)

  20. Effect of In-Situ Cure on Measurement of Glass Transition Temperatures in High-Temperature Thermosetting Polymers (Briefing Charts)

    Science.gov (United States)

    2015-05-20

    TEMPERATURES IN HIGH-TEMPERATURE THERMOSETTING POLYMERS 5a. CONTRACT NUMBER In-House 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d...temperature thermosetting polymer via dynamic mechanical analysis alone. These difficulties result from the residual cure of samples heated beyond their...98) Prescribed by ANSI Std. 239.18 Effect of In-Situ Cure on Measurement of Glass Transition Temperatures in High-Temperature Thermosetting

  1. A High-Sensitivity Current Sensor Utilizing CrNi Wire and Microfiber Coils

    Directory of Open Access Journals (Sweden)

    Xiaodong Xie

    2014-05-01

    Full Text Available We obtain an extremely high current sensitivity by wrapping a section of microfiber on a thin-diameter chromium-nickel wire. Our detected current sensitivity is as high as 220.65 nm/A2 for a structure length of only 35 μm. Such sensitivity is two orders of magnitude higher than the counterparts reported in the literature. Analysis shows that a higher resistivity or/and a thinner diameter of the metal wire may produce higher sensitivity. The effects of varying the structure parameters on sensitivity are discussed. The presented structure has potential for low-current sensing or highly electrically-tunable filtering applications.

  2. High-resolution, high-sensitivity NMR of nano-litre anisotropic samples by coil spinning

    Energy Technology Data Exchange (ETDEWEB)

    Sakellariou, D [CEA Saclay, DSM, DRECAM, SCM, Lab Struct and Dynam Resonance Magnet, CNRS URA 331, F-91191 Gif Sur Yvette, (France); Le Goff, G; Jacquinot, J F [CEA Saclay, DSM, DRECAM, SPEC: Serv Phys Etat Condense, CNRS URA 2464, F-91191 Gif Sur Yvette, (France)

    2007-07-01

    Nuclear magnetic resonance (NMR) can probe the local structure and dynamic properties of liquids and solids, making it one of the most powerful and versatile analytical methods available today. However, its intrinsically low sensitivity precludes NMR analysis of very small samples - as frequently used when studying isotopically labelled biological molecules or advanced materials, or as preferred when conducting high-throughput screening of biological samples or 'lab-on-a-chip' studies. The sensitivity of NMR has been improved by using static micro-coils, alternative detection schemes and pre-polarization approaches. But these strategies cannot be easily used in NMR experiments involving the fast sample spinning essential for obtaining well-resolved spectra from non-liquid samples. Here we demonstrate that inductive coupling allows wireless transmission of radio-frequency pulses and the reception of NMR signals under fast spinning of both detector coil and sample. This enables NMR measurements characterized by an optimal filling factor, very high radio-frequency field amplitudes and enhanced sensitivity that increases with decreasing sample volume. Signals obtained for nano-litre-sized samples of organic powders and biological tissue increase by almost one order of magnitude (or, equivalently, are acquired two orders of magnitude faster), compared to standard NMR measurements. Our approach also offers optimal sensitivity when studying samples that need to be confined inside multiple safety barriers, such as radioactive materials. In principle, the co-rotation of a micrometer-sized detector coil with the sample and the use of inductive coupling (techniques that are at the heart of our method) should enable highly sensitive NMR measurements on any mass-limited sample that requires fast mechanical rotation to obtain well-resolved spectra. The method is easy to implement on a commercial NMR set-up and exhibits improved performance with miniaturization, and we

  3. From Molecular Design to Co-sensitization; High performance indole based photosensitizers for dye-sensitized solar cells

    International Nuclear Information System (INIS)

    Babu, Dickson D.; Su, Rui; El-Shafei, Ahmed; Adhikari, Airody Vasudeva

    2016-01-01

    displays promising photovoltaic results and exhibited an enhanced efficiency of 8.06%. Further, good agreement between the calculated and experimental results showcase the precision of the energy functional and basis set utilized in this study. All these findings provide a deeper insight and better understanding into the intricacies involved in the design of superior co-sensitizers for development of highly efficient DSSCs.

  4. Novel Modified Optical Fibers for High Temperature In-Situ Miniaturized Gas Sensors in Advanced Fossil Energy Systems

    Energy Technology Data Exchange (ETDEWEB)

    Pickrell, Gary [Virginia Polytechnic Institute & State University, Blacksburg, VA (United States); Scott, Brian [Virginia Polytechnic Institute & State University, Blacksburg, VA (United States)

    2014-06-30

    This report covers the technical progress on the program “Novel Modified Optical Fibers for High Temperature In-Situ Miniaturized Gas Sensors in Advanced Fossil Energy Systems”, funded by the National Energy Technology Laboratory of the U.S. Department of Energy, and performed by the Materials Science & Engineering and Electrical & Computer Engineering Departments at Virginia Tech, and summarizes technical progress from July 1st, 2005 –June 30th, 2014. The objective of this program was to develop novel fiber materials for high temperature gas sensors based on evanescent wave absorption in optical fibers. This project focused on two primary areas: the study of a sapphire photonic crystal fiber (SPCF) for operation at high temperature and long wavelengths, and a porous glass based fiber optic sensor for gas detection. The sapphire component of the project focused on the development of a sapphire photonic crystal fiber, modeling of the new structures, fabrication of the optimal structure, development of a long wavelength interrogation system, testing of the optical properties, and gas and temperature testing of the final sensor. The fabrication of the 6 rod SPCF gap bundle (diameter of 70μm) with a hollow core was successfully constructed with lead-in and lead-out 50μm diameter fiber along with transmission and gas detection testing. Testing of the sapphire photonic crystal fiber sensor capabilities with the developed long wavelength optical system showed the ability to detect CO2 at or below 1000ppm at temperatures up to 1000°C. Work on the porous glass sensor focused on the development of a porous clad solid core optical fiber, a hollow core waveguide, gas detection capabilities at room and high temperature, simultaneous gas species detection, suitable joining technologies for the lead-in and lead-out fibers and the porous sensor, sensor system sensitivity improvement, signal processing improvement, relationship between pore structure and fiber

  5. New approach to 3-D, high sensitivity, high mass resolution space plasma composition measurements

    International Nuclear Information System (INIS)

    McComas, D.J.; Nordholt, J.E.

    1990-01-01

    This paper describes a new type of 3-D space plasma composition analyzer. The design combines high sensitivity, high mass resolution measurements with somewhat lower mass resolution but even higher sensitivity measurements in a single compact and robust design. While the lower resolution plasma measurements are achieved using conventional straight-through time-of-flight mass spectrometry, the high mass resolution measurements are made by timing ions reflected in a linear electric field (LEF), where the restoring force that an ion experiences is proportional to the depth it travels into the LEF region. Consequently, the ion's equation of motion in that dimension is that of a simple harmonic oscillator and its travel time is simply proportional to the square root of the ion's mass/charge (m/q). While in an ideal LEF, the m/q resolution can be arbitrarily high, in a real device the resolution is limited by the field linearity which can be achieved. In this paper we describe how a nearly linear field can be produced and discuss how the design can be optimized for various different plasma regimes and spacecraft configurations

  6. Bio-camouflage of anatase nanoparticles explored by in situ high-resolution electron microscopy.

    Science.gov (United States)

    Ribeiro, Ana R; Mukherjee, Arijita; Hu, Xuan; Shafien, Shayan; Ghodsi, Reza; He, Kun; Gemini-Piperni, Sara; Wang, Canhui; Klie, Robert F; Shokuhfar, Tolou; Shahbazian-Yassar, Reza; Borojevic, Radovan; Rocha, Luis A; Granjeiro, José M

    2017-08-03

    While titanium is the metal of choice for most prosthetics and inner body devices due to its superior biocompatibility, the discovery of Ti-containing species in the adjacent tissue as a result of wear and corrosion has been associated with autoimmune diseases and premature implant failures. Here, we utilize the in situ liquid cell transmission electron microscopy (TEM) in a liquid flow holder and graphene liquid cells (GLCs) to investigate, for the first time, the in situ nano-bio interactions between titanium dioxide nanoparticles and biological medium. This imaging and spectroscopy methodology showed the process of formation of an ionic and proteic bio-camouflage surrounding Ti dioxide (anatase) nanoparticles that facilitates their internalization by bone cells. The in situ understanding of the mechanisms of the formation of the bio-camouflage of anatase nanoparticles may contribute to the definition of strategies aimed at the manipulation of these NPs for bone regenerative purposes.

  7. High mass resolution time of flight mass spectrometer for measuring products in heterogeneous catalysis in highly sensitive microreactors

    DEFF Research Database (Denmark)

    Andersen, Thomas; Jensen, Robert; Christensen, M. K.

    2012-01-01

    We demonstrate a combined microreactor and time of flight system for testing and characterization of heterogeneous catalysts with high resolution mass spectrometry and high sensitivity. Catalyst testing is performed in silicon-based microreactors which have high sensitivity and fast thermal...

  8. Quantification of the resist dissolution process: an in situ analysis using high speed atomic force microscopy

    Science.gov (United States)

    Santillan, Julius Joseph; Shichiri, Motoharu; Itani, Toshiro

    2016-03-01

    This work focuses on the application of a high speed atomic force microscope (HS-AFM) for the in situ visualization / quantification of the resist dissolution process. This technique, as reported in the past, has provided useful pointers on the formation of resist patterns during dissolution. This paper discusses about an investigation made on the quantification of what we refer to as "dissolution unit size" or the basic units of patterning material dissolution. This was done through the establishment of an originally developed analysis method which extracts the difference between two succeeding temporal states of the material film surface (images) to indicate the amount of change occurring in the material film at a specific span of time. Preliminary experiments with actual patterning materials were done using a positive-tone EUV model resist composed only of polyhydroxystyrene (PHS)-based polymer with a molecular weight of 2,500 and a polydispersity index of 1.2. In the absence of a protecting group, the material was utilized at a 50nm film thickness with post application bake of 90°C/60s. The resulting film is soluble in the alkali-based developer even without exposure. Results have shown that the dissolution components (dissolution unit size) of the PHS-based material are not of fixed size. Instead, it was found that aside from one constantly dissolving unit size, another, much larger dissolution unit size trend also occurs during material dissolution. The presence of this larger dissolution unit size suggests an occurrence of "polymer clustering". Such polymer clustering was not significantly present during the initial stages of dissolution (near the original film surface) but becomes more persistently obvious after the dissolution process reaches a certain film thickness below the initial surface.

  9. Hydrochemical processes in lowland rivers: insights from in situ, high-resolution monitoring

    Directory of Open Access Journals (Sweden)

    A. J. Wade

    2012-11-01

    Full Text Available This paper introduces new insights into the hydrochemical functioning of lowland river systems using field-based spectrophotometric and electrode technologies. The streamwater concentrations of nitrogen species and phosphorus fractions were measured at hourly intervals on a continuous basis at two contrasting sites on tributaries of the River Thames – one draining a rural catchment, the River Enborne, and one draining a more urban system, The Cut. The measurements complement those from an existing network of multi-parameter water quality sondes maintained across the Thames catchment and weekly monitoring based on grab samples. The results of the sub-daily monitoring show that streamwater phosphorus concentrations display highly complex dynamics under storm conditions dependent on the antecedent catchment wetness, and that diurnal phosphorus and nitrogen cycles occur under low flow conditions. The diurnal patterns highlight the dominance of sewage inputs in controlling the streamwater phosphorus and nitrogen concentrations at low flows, even at a distance of 7 km from the nearest sewage treatment works in the rural River Enborne. The time of sample collection is important when judging water quality against ecological thresholds or standards. An exhaustion of the supply of phosphorus from diffuse and multiple septic tank sources during storm events was evident and load estimation was not improved by sub-daily monitoring beyond that achieved by daily sampling because of the eventual reduction in the phosphorus mass entering the stream during events. The results highlight the utility of sub-daily water quality measurements and the discussion considers the practicalities and challenges of in situ, sub-daily monitoring.

  10. Retinal peripheral changes after laser in situ keratomileusis in patients with high myopia.

    Science.gov (United States)

    Suzuki, Cássia R; Farah, Michel E

    2004-02-01

    Retinal detachment has been reported after laser in situ keratomileusis (LASIK) in myopic eyes. This complication may be related to the risk from myopia before surgery or may be induced by LASIK surgery itself. We performed a study to evaluate retinal peripheral changes after LASIK in patients with high myopia and to correlate symptoms on presentation and vitreoretinal anatomic changes. The study was carried out at a university-affiliated hospital in São Paulo between November 1997 and February 1999. Patients scheduled to undergo LASIK were included if their spherical equivalent was greater than 6.00 dioptres. The exclusion criteria were previous retinal treatment and myopic macular degenerations. We performed binocular indirect ophthalmoscopy with scleral indentation and fundus biomicroscopy with Goldmann lens before LASIK and 1, 3 and 6 months after surgery. We examined 198 eyes preoperatively. Of the 198, 50 did not undergo LASIK surgery owing to refractive criteria, and 79 were lost to follow-up. We thus studied 69 eyes. The mean spherical equivalent preoperatively was -8.00 D (standard deviation 1.95 D). Twenty-four eyes had normal retinal periphery preoperatively; all 24 remained without alterations after LASIK. Forty-five eyes had peripheral alterations: 17 (24.6%) had cystic degeneration, 14 (20.3%) had lattice degeneration, 11 (15.9%) had white-without-pressure, 5 (7.2%) had cystic tufts, 3 (4.3%) had pavingstone degeneration, 2 (2.9%) had pigmentary alteration, 1 (1.4%) had holes with free operculum, and 1 (1.4%) had punctiform holes. The only alteration after surgery was almost punctiform holes around the previous cystic tuft 1 month after surgery in one patient. Retinal detachment did not develop in any of the eyes. In this group of patients it appears that LASIK did not lead to progressive peripheral retinal lesions in asymptomatic patients during the period studied.

  11. Analysis of Cyberbullying Sensitivity Levels of High School Students and Their Perceived Social Support Levels

    Science.gov (United States)

    Akturk, Ahmet Oguz

    2015-01-01

    Purpose: The purpose of this paper is to determine the cyberbullying sensitivity levels of high school students and their perceived social supports levels, and analyze the variables that predict cyberbullying sensitivity. In addition, whether cyberbullying sensitivity levels and social support levels differed according to gender was also…

  12. The Relationship between Ethical Sensitivity, High Ability and Gender in Higher Education Students

    Science.gov (United States)

    Schutte, Ingrid; Wolfensberger, Marca; Tirri, Kirsi

    2014-01-01

    This study examined the ethical sensitivity of high-ability undergraduate students (n=731) in the Netherlands who completed the 28-item Ethical Sensitivity Scale Questionnaire (ESSQ) developed by Tirri & Nokelainen (2007; 2011). The ESSQ is based on Narvaez' (2001) operationalization of ethical sensitivity in seven dimensions. The following…

  13. Platinum decorated carbon nanotubes for highly sensitive amperometric glucose sensing

    International Nuclear Information System (INIS)

    Xie Jining; Wang Shouyan; Aryasomayajula, L; Varadan, V K

    2007-01-01

    Fine platinum nanoparticles (1-5 nm in diameter) were deposited on functionalized multi-walled carbon nanotubes (MWNTs) through a decoration technique. A novel type of enzymatic Pt/MWNTs paste-based mediated glucose sensor was fabricated. Electrochemical measurements revealed a significantly improved sensitivity (around 52.7 μA mM -1 cm -2 ) for glucose sensing without using any picoampere booster or Faraday cage. In addition, the calibration curve exhibited a good linearity in the range of 1-28 mM of glucose concentration. Transmission electron microscopy (TEM) and x-ray photoelectron spectroscopy (XPS) were performed to investigate the nanoscale structure and the chemical bonding information of the Pt/MWNTs paste-based sensing material, respectively. The improved sensitivity of this novel glucose sensor could be ascribed to its higher electroactive surface area, enhanced electron transfer, efficient enzyme immobilization, unique interaction in nanoscale and a synergistic effect on the current signal from possible multi-redox reactions

  14. High Sensitivity TSS Prediction: Estimates of Locations Where TSS Cannot Occur

    KAUST Repository

    Schaefer, Ulf; Kodzius, Rimantas; Kai, Chikatoshi; Kawai, Jun; Carninci, Piero; Hayashizaki, Yoshihide; Bajic, Vladimir B.

    2013-01-01

    from mouse and human genomes, we developed a methodology that allows us, by performing computational TSS prediction with very high sensitivity, to annotate, with a high accuracy in a strand specific manner, locations of mammalian genomes that are highly

  15. Low-Cost High-Performance Cryocoolers for In-Situ Propellant Production

    Science.gov (United States)

    Martin, J. L.; Corey, J. A.; Peters, T. A.

    1999-01-01

    A key feature of many In-Situ Resource Utilization (ISRU) schemes is the production of rocket fuel and oxidizer from the Martian atmosphere. Many of the fuels under consideration will require cryogenic cooling for efficient long-term storage. Although significant research has been focused on the techniques for producing the fuels from Martian resources, little effort has been expended on the development of cryocoolers to efficiently liquefy these fuels. This paper describes the design of a pulse tube liquefier optimized for liquefying oxygen produced by an In-Situ Propellant Production (ISPP) plant on Mars.

  16. In-situ ionic conductivity measurement of lithium ceramics under high energy heavy ion irradiation

    International Nuclear Information System (INIS)

    Nakazawa, Tetsuya; Noda, Kenji; Ishii, Yoshinobu; Ohno, Hideo; Watanabe, Hitoshi; Matsui, Hisayuki.

    1992-01-01

    To obtain fundamental information regarding the radiation damage in some lithium ceramics, e.g. Li 2 O, Li 4 SiO 4 etc., candidate of breeder materials exposed to severe irradiation environment, an in-situ experiment technique for the ionic conductivity measurement, which allows the specimen temperature control and the beam current monitoring, have been developed. This paper describes the features of an apparatus to measure in situ the ionic conductivity under the irradiation environment and presents some results of ionic conductivity measured for typical ceramic breeders using this apparatus. (J.P.N.)

  17. Assessment of the Vibrations Effects Caused by Technical Seismicity Due to the Railway traffic on High-sensitivity Machinery

    Science.gov (United States)

    Papán, Daniel; Valašková, Veronika; Demeterová, Katarína

    2016-10-01

    The numerical and experimental approach in structural dynamics problems is more and more current nowadays. This approach is applied and solved in many research and developing institutions of the all the world. Vibrations effect caused by passing trains used in manufacturing facilities can affect the quality of the production activity. This effect is possible to be solved by a numerical or an experimental way. Numerical solution is not so financially and time demanding. The main aim of this article is to focus on just experimental measurement of this problem. In this paper, the case study with measurement due to cramped conditions realized in situ is presented. The case study is located close to railway. The vibration effect caused by passing trains on the high-sensitivity machinery contained in this object were observed. The structure was a high-sensitivity machine that was placed in a construction process. For the measurements, the high-sensitivity standard vibrations equipment was used. The assessments of measurements’ results were performed for the technological conditions and Slovak Standard Criteria. Both of these assessments were divided to amplitude and frequency domain. The amplitude criterion is also divided to peak particle velocity and RMS (Root Mean Square). Frequency domain assessment were realised using the frequency response curves obtained from high-sensitivity machinery manufacturer. The frequency limits are established for each axis of triaxle system. The measurement results can be predicted if the vibration have to be reduced. Measurement implemented in the production hall should obtain materials to determine the seismic loading and response of production machinery caused by technical seismicity.

  18. The chemical composition and mineralogy of meteorites measured with very high spatial resolution by a laser mass spectrometer for in situ planetary research

    Science.gov (United States)

    Brigitte Neuland, Maike; Mezger, Klaus; Tulej, Marek; Frey, Samira; Riedo, Andreas; Wurz, Peter; Wiesendanger, Reto

    2017-04-01

    The knowledge of the chemical composition of moons, comets, asteroids or other planetary bodies is of particular importance for the investigation of the origin and evolution of the Solar System. High resolution in situ studies on planetary surfaces can yield important information on surface heterogeneity, basic grain mineralogy and chemical composition of surface and subsurface. In turn, these data are the basis for our understanding of the physical and chemical processes which led to the formation and alteration of planetary material [1]. We investigated samples of Allende and Sayh al Uhaymir with a highly miniaturised laser mass spectrometer (LMS), which has been designed and built for in situ space research [2,3]. Both meteorite samples were investigated with a spatial resolution of about 10μm in lateral direction. The high sensitivity and high dynamic range of the LMS allow for quantitative measurements of the abundances of the rock-forming and minor and trace elements with high accuracy [4]. From the data, the modal mineralogy of micrometre-sized chondrules can be inferred [5], conclusions about the condensation sequence of the material are possible and the sensitivity for radiogenic elements allows for dating analyses of the investigated material. We measured the composition of various chondrules in Allende, offering valuable clues about the condensation sequence of the different components of the meteorite. We explicitly investigated the chemical composition and heterogeneity of the Allende matrix with an accuracy that cannot be reached by the mechanical analysis methods that were and are widely used in meteoritic research. We demonstrate the capabilities for dating analyses with the LMS. By applying the U-Th-dating method, the age of the SaU169 sample could be determined. Our analyses show that the LMS would be a suitable instrument for high-quality quantitative chemical composition measurements on the surface of a celestial body like a planet, moon or

  19. Specific, sensitive, high-resolution detection of protein molecules in eukaryotic cells using metal-tagging transmission electron microscopy

    Science.gov (United States)

    Risco, Cristina; Sanmartín-Conesa, Eva; Tzeng, Wen-Pin; Frey, Teryl K.; Seybold, Volker; de Groot, Raoul J.

    2012-01-01

    Summary More than any other methodology, transmission electron microscopy (TEM) has contributed to our understanding of the architecture and organization of cells. With current detection limits approaching atomic resolution, it will ultimately become possible to ultrastructurally image intracellular macromolecular assemblies in situ. Presently, however, methods to unambiguously identify proteins within the crowded environment of the cell’s interior are lagging behind. We describe a novel approach, metal-tagging TEM (METTEM) that allows detection of intracellular proteins in mammalian cells with high specificity, exceptional sensitivity and at molecular scale resolution. In live cells treated with gold salts, proteins bearing a small metal-binding tag will form 1-nm gold nanoclusters, readily detectable in electron micrographs. The applicability and strength of METTEM is demonstrated by a study of Rubella virus replicase and capsid proteins, which revealed virus-induced cell structures not seen before. PMID:22579245

  20. Quantification of Eosinophilic Granule Protein Deposition in Biopsies of Inflammatory Skin Diseases by Automated Image Analysis of Highly Sensitive Immunostaining

    Directory of Open Access Journals (Sweden)

    Peter Kiehl

    1999-01-01

    Full Text Available Eosinophilic granulocytes are major effector cells in inflammation. Extracellular deposition of toxic eosinophilic granule proteins (EGPs, but not the presence of intact eosinophils, is crucial for their functional effect in situ. As even recent morphometric approaches to quantify the involvement of eosinophils in inflammation have been only based on cell counting, we developed a new method for the cell‐independent quantification of EGPs by image analysis of immunostaining. Highly sensitive, automated immunohistochemistry was done on paraffin sections of inflammatory skin diseases with 4 different primary antibodies against EGPs. Image analysis of immunostaining was performed by colour translation, linear combination and automated thresholding. Using strictly standardized protocols, the assay was proven to be specific and accurate concerning segmentation in 8916 fields of 520 sections, well reproducible in repeated measurements and reliable over 16 weeks observation time. The method may be valuable for the cell‐independent segmentation of immunostaining in other applications as well.

  1. In-situ electrochemical study of Zr1nb alloy corrosion in high temperature Li{sup +} containing water

    Energy Technology Data Exchange (ETDEWEB)

    Krausová, Aneta [University of Chemistry and Technology, Technická 3, 166 28 Prague 6 (Czech Republic); Macák, Jan, E-mail: macakj@vscht.cz [University of Chemistry and Technology, Technická 3, 166 28 Prague 6 (Czech Republic); Sajdl, Petr [University of Chemistry and Technology, Technická 3, 166 28 Prague 6 (Czech Republic); Novotný, Radek [JRC-IET, Westerduinveg 3, 1755 LE Petten (Netherlands); Renčiuková, Veronika [University of Chemistry and Technology, Technická 3, 166 28 Prague 6 (Czech Republic); Vrtílková, Věra [ÚJP a.s., Nad Kamínkou 1345, 156 10 Prague 5 (Czech Republic)

    2015-12-15

    Long-term in-situ corrosion tests were performed in order to evaluate the influence of lithium ions on the corrosion of zirconium alloy. Experiments were carried out in a high-pressure high-temperature loop (280 °C, 8 MPa) in a high concentration water solution of LiOH (70 and 200 ppm Li{sup +}) and in a simulated WWER primary coolant environment. The kinetic parameters characterising the oxidation process have been explored using in-situ electrochemical impedance spectroscopy and slow potentiodynamic polarization. Also, a suitable equivalent circuit was suggested, which would approximate the impedance characteristics of the corrosion of Zr–1Nb alloy. The Mott–Schottky approach was used to determine the semiconducting character of the passive film. - Highlights: • Zr1Nb alloy was tested in WWER coolant and in LiOH solutions at 280 °C. • Corrosion rates were estimated in-situ from electrochemical data. • Electrochemical data agreed well with weight gains and metallography data. • Increase of corrosion rate in LiOH appeared after short exposure (300–500 h). • Very high donor densities (1.1–1.2 × 10{sup 20} cm{sup −3}) of Zr oxide grown in LiOH were found.

  2. Highly sensitive urea sensing with ion-irradiated polymer foils

    International Nuclear Information System (INIS)

    Fink, Dietmar; Muñoz Hernandez, Gerardo; Alfonta, Lital

    2012-01-01

    Recently we prepared urea-sensors by attaching urease to the inner walls of etched ion tracks within thin polymer foil. Here, alternative track-based sensor configurations are examined where the enzyme remained in solution. The conductivities of systems consisting of two parallel irradiated polymer foils and confining different urea/urease mixtures in between were examined. The correlations between conductivity and urea concentration differed strongly for foils with unetched and etched tracks, which points at different sensing mechanisms – tentatively attributed to the adsorption of enzymatic reaction products on the latent track entrances and to the enhanced conductivity of reaction product-filled etched tracks, respectively. All examined systems enable in principle, urea sensing. They point at the possibility of sensor cascade construction for more sensitive or selective sensor systems.

  3. A new compact, high sensitivity neutron imaging system

    Energy Technology Data Exchange (ETDEWEB)

    Caillaud, T.; Landoas, O.; Briat, M.; Rosse, B.; Thfoin, I.; Philippe, F.; Casner, A.; Bourgade, J. L.; Disdier, L. [CEA, DAM, DIF,F-91297 Arpajon (France); Glebov, V. Yu.; Marshall, F. J.; Sangster, T. C. [Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299 (United States); Park, H. S.; Robey, H. F.; Amendt, P. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)

    2012-10-15

    We have developed a new small neutron imaging system (SNIS) diagnostic for the OMEGA laser facility. The SNIS uses a penumbral coded aperture and has been designed to record images from low yield (10{sup 9}-10{sup 10} neutrons) implosions such as those using deuterium as the fuel. This camera was tested at OMEGA in 2009 on a rugby hohlraum energetics experiment where it recorded an image at a yield of 1.4 Multiplication-Sign 10{sup 10}. The resolution of this image was 54 {mu}m and the camera was located only 4 meters from target chamber centre. We recently improved the instrument by adding a cooled CCD camera. The sensitivity of the new camera has been fully characterized using a linear accelerator and a {sup 60}Co {gamma}-ray source. The calibration showed that the signal-to-noise ratio could be improved by using raw binning detection.

  4. A new compact, high sensitivity neutron imaging system

    International Nuclear Information System (INIS)

    Caillaud, T.; Landoas, O.; Briat, M.; Rossé, B.; Thfoin, I.; Philippe, F.; Casner, A.; Bourgade, J. L.; Disdier, L.; Glebov, V. Yu.; Marshall, F. J.; Sangster, T. C.; Park, H. S.; Robey, H. F.; Amendt, P.

    2012-01-01

    We have developed a new small neutron imaging system (SNIS) diagnostic for the OMEGA laser facility. The SNIS uses a penumbral coded aperture and has been designed to record images from low yield (10 9 –10 10 neutrons) implosions such as those using deuterium as the fuel. This camera was tested at OMEGA in 2009 on a rugby hohlraum energetics experiment where it recorded an image at a yield of 1.4 × 10 10 . The resolution of this image was 54 μm and the camera was located only 4 meters from target chamber centre. We recently improved the instrument by adding a cooled CCD camera. The sensitivity of the new camera has been fully characterized using a linear accelerator and a 60 Co γ-ray source. The calibration showed that the signal-to-noise ratio could be improved by using raw binning detection.

  5. In-situ Diffraction Study of Magnetite at Simultaneous High Pressure and High Temperature Using Synchrotron Radiation

    Science.gov (United States)

    Wang, L.; Zhang, J.; Wang, S.; Chen, H.; Zhao, Y.

    2014-12-01

    Magnetite intertwined with the evolution of human civilizations, and remains so today. It is technologically and scientifically important by virtue of its unique magnetic and electrical properties. Magnetite is a common mineral found in a variety of geologic environments, and plays an important role in deciphering the oxygen evolution in the Earth's atmosphere and its deep interiors. The latter application asks for the knowledge of the thermal and elastic properties of magnetite at high pressures and temperatures, which is currently not available in literature. We have carried out a few in-situ diffraction experiments on magnetite using white synchrotron radiation at beamline X17B2 of National Synchrotron Light Source (NSLS). A DIA module in an 1100-ton press and WC anvils were employed for compression, and diffraction spectra were collected at simultaneous high pressures (P) and temperatures (T) (up to 9 GPa and 900 oC). Mixture of amorphous boron and epoxy resin was used as pressure medium, and NaCl as pressure marker. Temperature was recorded by W-Re thermocouples. Commercially purchased magnetite powder and a mixture of the said powder and NaCl (1:1) were used as starting material in separate experiments. Preliminary data analyses have yielded following observations: (1) Charge disordering seen at ambient pressure remains active in current experiments, especially at lower pressures (reversibility and degree of cation disordering depend on the starting material and/or experimental P-T path; and (4) cation disordering notably reduces the apparent bulk moduli of magnetite.

  6. Soft nanomaterials analysed by in situ liquid TEM: Towards high resolution characterisation of nanoparticles in motion

    Directory of Open Access Journals (Sweden)

    Joseph P. Patterson

    2015-12-01

    Full Text Available In this article we present in situ transmission electron microscopy (TEM of soft, synthetic nanoparticles with a comparative analysis using conventional TEM methods. This comparison is made with the simple aim of describing what is an unprecedented example of in situ imaging by TEM. However, we contend the technique will quickly become essential in the characterisation of analogous systems, especially where dynamics are of interest in the solvated state. In this case, particles were studied which were obtained from the direct polymerisation of an oxaliplatin analogue, designed for an ongoing programme in novel chemotherapeutic delivery systems. The resulting nanoparticles provided sufficient contrast for facile imaging in situ, and point towards key design parameters that enable this new characterisation approach for organic nanomaterials. We describe the preparation of the synthetic nanoparticles together with their characterisation in liquid water. Finally, we provide a future perspective of this technique for the analysis of soft and dynamic nanomaterials and discussion the progress which needs to be made in order to bring in situ liquid TEM to its full potential.

  7. Spectrometer and Radiative Transfer Model Comparison using High Sun In-Situ Observations in Pretoria

    CSIR Research Space (South Africa)

    Lysko, MD

    2012-08-01

    Full Text Available There is need for reliable in-situ spectral solar irradiance measurements. For instance, the spectrally resolved irradiance may be used to infer its influence on radiative forcing of climate and in solar energy applications. In any case, reliable...

  8. In situ X-ray ptychography imaging of high-temperature CO2 acceptor particle agglomerates

    DEFF Research Database (Denmark)

    Høydalsvik, Kristin; Fløystad, Jostein Bø; Zhao, Tiejun

    2014-01-01

    be used for in situ phase contrast imaging in structure studies at atmospheric pressure and elevated temperatures. Lithium zirconate, a candidate CO2 capture material, was studied at a pressure of one atmosphere in air and in CO2, at temperatures exceeding 600 °C. Images with a spatial resolution better...

  9. Combined Confocal and Wide-Field High-Resolution Cytometry of Fluorescent In Situ Hybridization-Stained Cells

    Czech Academy of Sciences Publication Activity Database

    Kozubek, Michal; Kozubek, Stanislav; Lukášová, Emilie; Bártová, Eva; Skalníková, M.; Matula, Pa.; Matula, Pe.; Jirsová, Pavla; Cafourková, Alena; Koutná, Irena

    2001-01-01

    Roč. 45, č. 1 (2001), s. 1-12 ISSN 0196-4763 R&D Projects: GA MŠk VS97031; GA ČR GA202/99/P008; GA AV ČR IBS5004010 Institutional research plan: CEZ:AV0Z5004920 Keywords : high-resolution cytometry * fluorescence in situ hybridization * interphase nuclei Subject RIV: BO - Biophysics Impact factor: 2.220, year: 2001

  10. In situ observation of high temperature tensile deformation and low cycle fatigue response in a nickel-base superalloy

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Xudong, E-mail: lxdong0700@hotmail.com; Du, Jinhui; Deng, Qun

    2013-12-20

    High temperature tension and low cycle fatigue experiments of IN718 alloy have been performed in the electro-hydraulic servo system with scanning electron microscope at 455 °C. Fatigue crack initiation and propagation process are investigated in situ. Results show that the carbide and twin grain are the crack source of the low cycle fatigue of IN718 alloy, and the low cycle fatigue life of the alloy increases with the decrease in grain size.

  11. In-situ high temperature irradiation setup for temperature dependent structural studies of materials under swift heavy ion irradiation

    International Nuclear Information System (INIS)

    Kulriya, P.K.; Kumari, Renu; Kumar, Rajesh; Grover, V.; Shukla, R.; Tyagi, A.K.; Avasthi, D.K.

    2015-01-01

    An in-situ high temperature (1000 K) setup is designed and installed in the materials science beam line of superconducting linear accelerator at the Inter-University Accelerator Centre (IUAC) for temperature dependent ion irradiation studies on the materials exposed with swift heavy ion (SHI) irradiation. The Gd 2 Ti 2 O 7 pyrochlore is irradiated using 120 MeV Au ion at 1000 K using the high temperature irradiation facility and characterized by ex-situ X-ray diffraction (XRD). Another set of Gd 2 Ti 2 O 7 samples are irradiated with the same ion beam parameter at 300 K and simultaneously characterized using in-situ XRD available in same beam line. The XRD studies along with the Raman spectroscopic investigations reveal that the structural modification induced by the ion irradiation is strongly dependent on the temperature of the sample. The Gd 2 Ti 2 O 7 is readily amorphized at an ion fluence 6 × 10 12 ions/cm 2 on irradiation at 300 K, whereas it is transformed to a radiation-resistant anion-deficient fluorite structure on high temperature irradiation, that amorphized at ion fluence higher than 1 × 10 13 ions/cm 2 . The temperature dependent ion irradiation studies showed that the ion fluence required to cause amorphization at 1000 K irradiation is significantly higher than that required at room temperature irradiation. In addition to testing the efficiency of the in-situ high temperature irradiation facility, the present study establishes that the radiation stability of the pyrochlore is enhanced at higher temperatures

  12. High fat diet-fed obese rats are highly sensitive to doxorubicin-induced cardiotoxicity

    International Nuclear Information System (INIS)

    Mitra, Mayurranjan S.; Donthamsetty, Shashikiran; White, Brent; Mehendale, Harihara M.

    2008-01-01

    Often, chemotherapy by doxorubicin (Adriamycin) is limited due to life threatening cardiotoxicity in patients during and posttherapy. Recently, we have shown that moderate diet restriction remarkably protects against doxorubicin-induced cardiotoxicity. This cardioprotection is accompanied by decreased cardiac oxidative stress and triglycerides and increased cardiac fatty-acid oxidation, ATP synthesis, and upregulated JAK/STAT3 pathway. In the current study, we investigated whether a physiological intervention by feeding 40% high fat diet (HFD), which induces obesity in male Sprague-Dawley rats (250-275 g), sensitizes to doxorubicin-induced cardiotoxicity. A LD 10 dose (8 mg doxorubicin/kg, ip) administered on day 43 of the HFD feeding regimen led to higher cardiotoxicity, cardiac dysfunction, lipid peroxidation, and 80% mortality in the obese (OB) rats in the absence of any significant renal or hepatic toxicity. Doxorubicin toxicokinetics studies revealed no change in accumulation of doxorubicin and doxorubicinol (toxic metabolite) in the normal diet-fed (ND) and OB hearts. Mechanistic studies revealed that OB rats are sensitized due to: (1) higher oxyradical stress leading to upregulation of uncoupling proteins 2 and 3, (2) downregulation of cardiac peroxisome proliferators activated receptor-α, (3) decreased plasma adiponectin levels, (4) decreased cardiac fatty-acid oxidation (666.9 ± 14.0 nmol/min/g heart in ND versus 400.2 ± 11.8 nmol/min/g heart in OB), (5) decreased mitochondrial AMP-α2 protein kinase, and (6) 86% drop in cardiac ATP levels accompanied by decreased ATP/ADP ratio after doxorubicin administration. Decreased cardiac erythropoietin and increased SOCS3 further downregulated the cardioprotective JAK/STAT3 pathway. In conclusion, HFD-induced obese rats are highly sensitized to doxorubicin-induced cardiotoxicity by substantially downregulating cardiac mitochondrial ATP generation, increasing oxidative stress and downregulating the JAK/STAT3

  13. Diagnostic sensitivity and specificity of in situ hybridization and immunohistochemistry for Eastern equine encephalitis virus and West Nile virus in formalin-fixed, paraffin-embedded brain tissue of horses.

    Science.gov (United States)

    Pennick, Kate E; McKnight, Christy A; Patterson, Jon S; Latimer, Kenneth S; Maes, Roger K; Wise, Annabel G; Kiupel, Matti

    2012-03-01

    Immunohistochemistry (IHC) and in situ hybridization (ISH) can be used either to detect or to differentiate between Eastern equine encephalitis virus (EEEV) and West Nile virus (WNV) within formalin-fixed, paraffin-embedded (FFPE) brain tissue of horses. To compare the diagnostic sensitivity and specificity of ISH and IHC, FFPE brain tissue from 20 EEEV-positive horses and 16 WNV-positive horses were tested with both EEEV and WNV oligoprobes and EEEV- and WNV-specific antibodies. Reverse transcription polymerase chain reaction (RT-PCR) for detection of EEEV and WNV was used as the gold standard to confirm infection. All horses that tested positive for EEEV by RT-PCR also tested positive by IHC and ISH, except for 1 case that was false-negative by ISH. In contrast, all horses that tested positive for WNV by RT-PCR tested negative by IHC and only 2 horses tested positive by ISH. No false-positives were detected with either method for both viruses. Both IHC and ISH are highly specific and sensitive diagnostic methods to detect EEEV in equine FFPE brain tissues, although neither appear effective for the diagnosis of WNV in equine neurologic cases.

  14. Highly sensitive assay for tyrosine hydroxylase activity by high-performance liquid chromatography.

    Science.gov (United States)

    Nagatsu, T; Oka, K; Kato, T

    1979-07-21

    A highly sensitive assay for tyrosine hydroxylase (TH) activity by high-performance liquid chromatography (HPLC) with amperometric detection was devised based on the rapid isolation of enzymatically formed DOPA by a double-column procedure, the columns fitted together sequentially (the top column of Amberlite CG-50 and the bottom column of aluminium oxide). DOPA was adsorbed on the second aluminium oxide column, then eluted with 0.5 M hydrochloric acid, and assayed by HPLC with amperometric detection. D-Tyrosine was used for the control. alpha-Methyldopa was added to the incubation mixture as an internal standard after incubation. This assay was more sensitive than radioassays and 5 pmol of DOPA formed enzymatically could be measured in the presence of saturating concentrations of tyrosine and 6-methyltetrahydropterin. The TH activity in 2 mg of human putamen could be easily measured, and this method was found to be particularly suitable for the assay of TH activity in a small number of nuclei from animal and human brain.

  15. Simultaneous in situ measurements of properties of particulates in rf silane plasmas using a polarization-sensitive laser-light-scattering method

    Science.gov (United States)

    Shiratani, Masaharu; Kawasaki, Hiroharu; Fukuzawa, Tsuyoshi; Yoshioka, Takashi; Ueda, Yoshio; Singh, Sanjay; Watanabe, Yukio

    1996-01-01

    A polarization-sensitive laser-light-scattering method is developed for simultaneous in situ measurements of properties (size, size dispersion, density, and refractive index) of particulates formed in processing plasmas. The developed system is applied to observe the growth processes of particulates in a range of their size larger than about 10 nm in rf silane plasmas. A size, a size dispersion (logarithm of a standard deviation of size), a density, and a refractive index of particulates in the plasmas are found to be 10-200 nm, about 0.1, 107-109 cm-3 and about 3-5i, respectively. The former three of such values agree fairly well with ones deduced from scanning electron microscopic (SEM) observation. These particulates grow through three phases of nucleation and initial growth, rapid growth, and growth saturation. Coexistence of two size groups of particulates with narrow size dispersions during and after the rapid growth phase verified by the SEM observation may be explained by a model taking into account coagulation between oppositely charged particulates.

  16. In Situ Activation of Nitrogen-Doped Graphene Anchored on Graphite Foam for a High-Capacity Anode.

    Science.gov (United States)

    Ji, Junyi; Liu, Jilei; Lai, Linfei; Zhao, Xin; Zhen, Yongda; Lin, Jianyi; Zhu, Yanwu; Ji, Hengxing; Zhang, Li Li; Ruoff, Rodney S

    2015-08-25

    We report the fabrication of a three-dimensional free-standing nitrogen-doped porous graphene/graphite foam by in situ activation of nitrogen-doped graphene on highly conductive graphite foam (GF). After in situ activation, intimate "sheet contact" was observed between the graphene sheets and the GF. The sheet contact produced by in situ activation is found to be superior to the "point contact" obtained by the traditional drop-casting method and facilitates electron transfer. Due to the intimate contact as well as the use of an ultralight GF current collector, the composite electrode delivers a gravimetric capacity of 642 mAh g(-1) and a volumetric capacity of 602 mAh cm(-3) with respect to the whole electrode mass and volume (including the active materials and the GF current collector). When normalized based on the mass of the active material, the composite electrode delivers a high specific capacity of up to 1687 mAh g(-1), which is superior to that of most graphene-based electrodes. Also, after ∼90 s charging, the anode delivers a capacity of about 100 mAh g(-1) (with respect to the total mass of the electrode), indicating its potential use in high-rate lithium-ion batteries.

  17. Nitrogen detected TROSY at high field yields high resolution and sensitivity for protein NMR

    International Nuclear Information System (INIS)

    Takeuchi, Koh; Arthanari, Haribabu; Shimada, Ichio; Wagner, Gerhard

    2015-01-01

    Detection of 15 N in multidimensional NMR experiments of proteins has sparsely been utilized because of the low gyromagnetic ratio (γ) of nitrogen and the presumed low sensitivity of such experiments. Here we show that selecting the TROSY components of proton-attached 15 N nuclei (TROSY 15 N H ) yields high quality spectra in high field magnets (>600 MHz) by taking advantage of the slow 15 N transverse relaxation and compensating for the inherently low 15 N sensitivity. The 15 N TROSY transverse relaxation rates increase modestly with molecular weight but the TROSY gain in peak heights depends strongly on the magnetic field strength. Theoretical simulations predict that the narrowest line width for the TROSY 15 N H component can be obtained at 900 MHz, but sensitivity reaches its maximum around 1.2 GHz. Based on these considerations, a 15 N-detected 2D 1 H– 15 N TROSY-HSQC ( 15 N-detected TROSY-HSQC) experiment was developed and high-quality 2D spectra were recorded at 800 MHz in 2 h for 1 mM maltose-binding protein at 278 K (τ c  ∼ 40 ns). Unlike for 1 H detected TROSY, deuteration is not mandatory to benefit 15 N detected TROSY due to reduced dipolar broadening, which facilitates studies of proteins that cannot be deuterated, especially in cases where production requires eukaryotic expression systems. The option of recording 15 N TROSY of proteins expressed in H 2 O media also alleviates the problem of incomplete amide proton back exchange, which often hampers the detection of amide groups in the core of large molecular weight proteins that are expressed in D 2 O culture media and cannot be refolded for amide back exchange. These results illustrate the potential of 15 N H -detected TROSY experiments as a means to exploit the high resolution offered by high field magnets near and above 1 GHz

  18. Nitrogen detected TROSY at high field yields high resolution and sensitivity for protein NMR

    Energy Technology Data Exchange (ETDEWEB)

    Takeuchi, Koh [National Institute for Advanced Industrial Science and Technology, Molecular Profiling Research Center for Drug Discovery (Japan); Arthanari, Haribabu [Harvard Medical School, Department of Biochemistry and Molecular Pharmacology (United States); Shimada, Ichio, E-mail: shimada@iw-nmr.f.u-tokyo.ac.jp [National Institute for Advanced Industrial Science and Technology, Molecular Profiling Research Center for Drug Discovery (Japan); Wagner, Gerhard, E-mail: gerhard-wagner@hms.harvard.edu [Harvard Medical School, Department of Biochemistry and Molecular Pharmacology (United States)

    2015-12-15

    Detection of {sup 15}N in multidimensional NMR experiments of proteins has sparsely been utilized because of the low gyromagnetic ratio (γ) of nitrogen and the presumed low sensitivity of such experiments. Here we show that selecting the TROSY components of proton-attached {sup 15}N nuclei (TROSY {sup 15}N{sub H}) yields high quality spectra in high field magnets (>600 MHz) by taking advantage of the slow {sup 15}N transverse relaxation and compensating for the inherently low {sup 15}N sensitivity. The {sup 15}N TROSY transverse relaxation rates increase modestly with molecular weight but the TROSY gain in peak heights depends strongly on the magnetic field strength. Theoretical simulations predict that the narrowest line width for the TROSY {sup 15}N{sub H} component can be obtained at 900 MHz, but sensitivity reaches its maximum around 1.2 GHz. Based on these considerations, a {sup 15}N-detected 2D {sup 1}H–{sup 15}N TROSY-HSQC ({sup 15}N-detected TROSY-HSQC) experiment was developed and high-quality 2D spectra were recorded at 800 MHz in 2 h for 1 mM maltose-binding protein at 278 K (τ{sub c} ∼ 40 ns). Unlike for {sup 1}H detected TROSY, deuteration is not mandatory to benefit {sup 15}N detected TROSY due to reduced dipolar broadening, which facilitates studies of proteins that cannot be deuterated, especially in cases where production requires eukaryotic expression systems. The option of recording {sup 15}N TROSY of proteins expressed in H{sub 2}O media also alleviates the problem of incomplete amide proton back exchange, which often hampers the detection of amide groups in the core of large molecular weight proteins that are expressed in D{sub 2}O culture media and cannot be refolded for amide back exchange. These results illustrate the potential of {sup 15}N{sub H}-detected TROSY experiments as a means to exploit the high resolution offered by high field magnets near and above 1 GHz.

  19. Applications of molecules as high-resolution, high-sensitivity threshold electron detectors

    International Nuclear Information System (INIS)

    Chutjian, A.

    1991-01-01

    The goal of the work under the contract entitled ''Applications of Molecules as High-Resolution, High-Sensitivity Threshold Electron Detectors'' (DoE IAA No. DE-AI01-83ER13093 Mod. A006) was to explore the electron attachment properties of a variety of molecules at electron energies not accessible by other experimental techniques. As a result of this work, not only was a large body of basic data measured on attachment cross sections and rate constants; but also extensive theoretical calculations were carried out to verify the underlying phenomenon of s-wave attachment. Important outgrowths of this week were also realized in other areas of research. The basic data have applications in fields such as combustion, soot reduction, rocket-exhaust modification, threshold photoelectron spectroscopy, and trace species detection

  20. An application of impediography to the high sensitivity and high resolution identification of structural damage

    International Nuclear Information System (INIS)

    Zhao, L; Yang, J; Semperlotti, F; Wang, K W

    2015-01-01

    In this study we explore the use of impediographic techniques to perform damage detection in plate-like metal structures. Impediography relies on the piezo-resistive coupling of the host structure to reconstruct high sensitivity and high resolution maps of the internal electrical conductivity. By exploiting localized strain perturbations generated via focused acoustic waves, the piezo-resistive coupling allows extracting a set of linearly independent boundary voltage data that drastically reduces the ill-conditioning of the inverse problem, therefore increasing the performance. The localized perturbation is achieved by leveraging the concept of frequency selective structure (FSS), that is a dynamically tailored structural element enabling the required acoustic focusing via vibration localization. Based on the FSS approach, the impediographic technique is numerically tested to investigate the performance of the combined approach for structural damage detection. The effects of practical implementation issues, such as limited perturbations and limited boundary data, are also explored. (paper)

  1. Storing quantum information in spins and high-sensitivity ESR.

    Science.gov (United States)

    Morton, John J L; Bertet, Patrice

    2018-02-01

    Quantum information, encoded within the states of quantum systems, represents a novel and rich form of information which has inspired new types of computers and communications systems. Many diverse electron spin systems have been studied with a view to storing quantum information, including molecular radicals, point defects and impurities in inorganic systems, and quantum dots in semiconductor devices. In these systems, spin coherence times can exceed seconds, single spins can be addressed through electrical and optical methods, and new spin systems with advantageous properties continue to be identified. Spin ensembles strongly coupled to microwave resonators can, in principle, be used to store the coherent states of single microwave photons, enabling so-called microwave quantum memories. We discuss key requirements in realising such memories, including considerations for superconducting resonators whose frequency can be tuned onto resonance with the spins. Finally, progress towards microwave quantum memories and other developments in the field of superconducting quantum devices are being used to push the limits of sensitivity of inductively-detected electron spin resonance. The state-of-the-art currently stands at around 65 spins per Hz, with prospects to scale down to even fewer spins. Copyright © 2017. Published by Elsevier Inc.

  2. Storing quantum information in spins and high-sensitivity ESR

    Science.gov (United States)

    Morton, John J. L.; Bertet, Patrice

    2018-02-01

    Quantum information, encoded within the states of quantum systems, represents a novel and rich form of information which has inspired new types of computers and communications systems. Many diverse electron spin systems have been studied with a view to storing quantum information, including molecular radicals, point defects and impurities in inorganic systems, and quantum dots in semiconductor devices. In these systems, spin coherence times can exceed seconds, single spins can be addressed through electrical and optical methods, and new spin systems with advantageous properties continue to be identified. Spin ensembles strongly coupled to microwave resonators can, in principle, be used to store the coherent states of single microwave photons, enabling so-called microwave quantum memories. We discuss key requirements in realising such memories, including considerations for superconducting resonators whose frequency can be tuned onto resonance with the spins. Finally, progress towards microwave quantum memories and other developments in the field of superconducting quantum devices are being used to push the limits of sensitivity of inductively-detected electron spin resonance. The state-of-the-art currently stands at around 65 spins per √{ Hz } , with prospects to scale down to even fewer spins.

  3. Highly sensitive DNA sensors based on cerium oxide nanorods

    Science.gov (United States)

    Nguyet, Nguyen Thi; Hai Yen, Le Thi; Van Thu, Vu; lan, Hoang; Trung, Tran; Vuong, Pham Hung; Tam, Phuong Dinh

    2018-04-01

    In this work, a CeO2 nanorod (NR)-based electrochemical DNA sensor was developed to identify Salmonella that causes food-borne infections. CeO2 NRs were synthesized without templates via a simple and unexpensive hydrothermal approach at 170 °C for 12 h by using CeO(NO3)3·6H2O as a Ce source. The DNA probe was immobilized onto the CeO2 NR-modified electrode through covalent attachment. The characteristics of the hybridized DNA were analyzed through electrochemical impedance spectroscopy (EIS) with [Fe(CN)6]3-/4- as a redox probe. Experimental results showed that electron transfer resistance (Ret) increased after the DNA probe was attached to the electrode surface and increased further after the DNA probe hybridized with its complementary sequence. A linear response of Ret to the target DNA concentration was found from 0.01 μM to 2 μM. The detection limit and sensitivity of the DNA sensor were 0.01 μM and 3362.1 Ω μM-1 cm-2, respectively. Various parameters, such as pH value, ionic strength, DNA probe concentration, and hybridization time, influencing DNA sensor responses were also investigated.

  4. High-resolution high-sensitivity elemental imaging by secondary ion mass spectrometry: from traditional 2D and 3D imaging to correlative microscopy

    International Nuclear Information System (INIS)

    Wirtz, T; Philipp, P; Audinot, J-N; Dowsett, D; Eswara, S

    2015-01-01

    Secondary ion mass spectrometry (SIMS) constitutes an extremely sensitive technique for imaging surfaces in 2D and 3D. Apart from its excellent sensitivity and high lateral resolution (50 nm on state-of-the-art SIMS instruments), advantages of SIMS include high dynamic range and the ability to differentiate between isotopes. This paper first reviews the underlying principles of SIMS as well as the performance and applications of 2D and 3D SIMS elemental imaging. The prospects for further improving the capabilities of SIMS imaging are discussed. The lateral resolution in SIMS imaging when using the microprobe mode is limited by (i) the ion probe size, which is dependent on the brightness of the primary ion source, the quality of the optics of the primary ion column and the electric fields in the near sample region used to extract secondary ions; (ii) the sensitivity of the analysis as a reasonable secondary ion signal, which must be detected from very tiny voxel sizes and thus from a very limited number of sputtered atoms; and (iii) the physical dimensions of the collision cascade determining the origin of the sputtered ions with respect to the impact site of the incident primary ion probe. One interesting prospect is the use of SIMS-based correlative microscopy. In this approach SIMS is combined with various high-resolution microscopy techniques, so that elemental/chemical information at the highest sensitivity can be obtained with SIMS, while excellent spatial resolution is provided by overlaying the SIMS images with high-resolution images obtained by these microscopy techniques. Examples of this approach are given by presenting in situ combinations of SIMS with transmission electron microscopy (TEM), helium ion microscopy (HIM) and scanning probe microscopy (SPM). (paper)

  5. Design and development of a highly sensitive, field portable plasma source instrument for on-line liquid stream monitoring and real-time sample analysis

    International Nuclear Information System (INIS)

    Duan, Yixiang; Su, Yongxuan; Jin, Zhe; Abeln, Stephen P.

    2000-01-01

    The development of a highly sensitive, field portable, low-powered instrument for on-site, real-time liquid waste stream monitoring is described in this article. A series of factors such as system sensitivity and portability, plasma source, sample introduction, desolvation system, power supply, and the instrument configuration, were carefully considered in the design of the portable instrument. A newly designed, miniature, modified microwave plasma source was selected as the emission source for spectroscopy measurement, and an integrated small spectrometer with a charge-coupled device detector was installed for signal processing and detection. An innovative beam collection system with optical fibers was designed and used for emission signal collection. Microwave plasma can be sustained with various gases at relatively low power, and it possesses high detection capabilities for both metal and nonmetal pollutants, making it desirable to use for on-site, real-time, liquid waste stream monitoring. An effective in situ sampling system was coupled with a high efficiency desolvation device for direct-sampling liquid samples into the plasma. A portable computer control system is used for data processing. The new, integrated instrument can be easily used for on-site, real-time monitoring in the field. The system possesses a series of advantages, including high sensitivity for metal and nonmetal elements; in situ sampling; compact structure; low cost; and ease of operation and handling. These advantages will significantly overcome the limitations of previous monitoring techniques and make great contributions to environmental restoration and monitoring. (c)

  6. In Situ Apparatus to Study Gas-Metal Reactions and Wettability at High Temperatures for Hot-Dip Galvanizing Applications

    Science.gov (United States)

    Koltsov, A.; Cornu, M.-J.; Scheid, J.

    2018-02-01

    The understanding of gas-metal reactions and related surface wettability at high temperatures is often limited due to the lack of in situ surface characterization. Ex situ transfers at low temperature between annealing furnace, wettability device, and analytical tools induce noticeable changes of surface composition distinct from the reality of the phenomena.Therefore, a high temperature wettability device was designed in order to allow in situ sample surface characterization by x-rays photoelectron spectroscopy after gas/metal and liquid metal/solid metal surface reactions. Such airless characterization rules out any contamination and oxidation of surfaces and reveals their real composition after heat treatment and chemical reaction. The device consists of two connected reactors, respectively, dedicated to annealing treatments and wettability measurements. Heat treatments are performed in an infrared lamp furnace in a well-controlled atmosphere conditions designed to reproduce gas-metal reactions occurring during the industrial recrystallization annealing of steels. Wetting experiments are carried out in dispensed drop configuration with the precise control of the deposited droplets kinetic energies. The spreading of drops is followed by a high-speed CCD video camera at 500-2000 frames/s in order to reach information at very low contact time. First trials have started to simulate phenomena occurring during recrystallization annealing and hot-dip galvanizing on polished pure Fe and FeAl8 wt.% samples. The results demonstrate real surface chemistry of steel samples after annealing when they are put in contact with liquid zinc alloy bath during hot-dip galvanizing. The wetting results are compared to literature data and coupled with the characterization of interfacial layers by FEG-Auger. It is fair to conclude that the results show the real interest of such in situ experimental setup for interfacial chemistry studies.

  7. Electrospray deposition of fullerenes in ultra-high vacuum: in situ scanning tunneling microscopy and photoemission spectroscopy

    International Nuclear Information System (INIS)

    Satterley, Christopher J; Perdigao, LuIs M A; Saywell, Alex; Magnano, Graziano; Rienzo, Anna; Mayor, Louise C; Dhanak, Vinod R; Beton, Peter H; O'Shea, James N

    2007-01-01

    Electrospray deposition of fullerenes on gold has been successfully observed by in situ room temperature scanning tunneling microscopy and photoemission spectroscopy. Step-edge decoration and hexagonal close-packed islands with a periodicity of 1 nm are observed at low and multilayer coverages respectively, in agreement with thermal evaporation studies. Photoemission spectroscopy shows that fullerenes are being deposited in high purity and are coupling to the gold surface as for thermal evaporation. These results open a new route for the deposition of thermally labile molecules under ultra-high vacuum conditions for a range of high resolution surface science techniques

  8. Highly efficient and stable cyclometalated ruthenium(II) complexes as sensitizers for dye-sensitized solar cells

    International Nuclear Information System (INIS)

    Huang, Jian-Feng; Liu, Jun-Min; Su, Pei-Yang; Chen, Yi-Fan; Shen, Yong; Xiao, Li-Min; Kuang, Dai-Bin; Su, Cheng-Yong

    2015-01-01

    Highlights: • Four novel thiocyanate-free cyclometalated ruthenium sensitizer were conveniently synthesized. • The D-CF 3 -sensitized DSSCs show higher efficiency compared to N719 based cells. • The DSSCs based on D-CF 3 and D-bisCF 3 sensitizers exhibit excellent long-term stability. • The diverse cyclometalated Ru complexes can be developed as high-performance sensitizers for use in DSSC. - Abstract: Four novel thiocyanate-free cyclometallted Ru(II) complexes, D-bisCF 3 , D-CF 3 , D-OMe, and D-DPA, with two 4,4′-dicarboxylic acid-2,2′-bipyridine together with a functionalized phenylpyridine ancillary ligand, have been designed and synthesized. The effect of different substituents (R = bisCF 3 , CF 3 , OMe, and DPA) on the ancillary C^N ligand on the photophysical properties and photovoltaic performance is investigated. Under standard global AM 1.5 solar conditions, the device based on D-CF 3 sensitizer gives a higher conversion efficiency of 8.74% than those based on D-bisCF 3 , D-OMe, and D-DPA, which can be ascribed to its broad range of visible light absorption, appropriate localization of the frontier orbitals, weak hydrogen bonds between -CF 3 and -OH groups at the TiO 2 surface, moderate dye loading on TiO 2 , and high charge collection efficiency. Moreover, the D-bisCF 3 and D-CF 3 based DSSCs exhibit good stability under 100 mW cm −2 light soaking at 60 °C for 400 h

  9. Photoelastic colloidal gel for a high-sensitivity strain sensor

    Science.gov (United States)

    Pan, Hui; Chen, Zhixin; Zhu, Shenmin; Jiang, Chun; Zhang, Di

    2018-04-01

    Nanoparticles, having the ability to self-assemble into an ordered structure in their suspensions, analogous to liquid crystals, have attracted extensive attention. Herein, we report a new type of colloidal gel with an ordered crystal structure assembled from 1D and 2D nanoparticles. The material has high elasticity and, more interestingly, it shows significant photoelasticity. Its refractive index can be tuned under external stress and exhibits an ultra-wide dynamic range (Δn) of the order of 10-2. Due to the large Δn, the material shows an extremely high strain sensibility of 720 nm/ɛ, an order of magnitude higher than the reported ones.

  10. High temperature in-situ observations of multi-segmented metal nanowires encapsulated within carbon nanotubes by in-situ filling technique.

    Science.gov (United States)

    Hayashi, Yasuhiko; Tokunaga, Tomoharu; Iijima, Toru; Iwata, Takuya; Kalita, Golap; Tanemura, Masaki; Sasaki, Katsuhiro; Kuroda, Kotaro

    2012-08-08

    Multi-segmented one-dimensional metal nanowires were encapsulated within carbon nanotubes (CNTs) through in-situ filling technique during plasma-enhanced chemical vapor deposition process. Transmission electron microscopy (TEM) and environmental TEM were employed to characterize the as-prepared sample at room temperature and high temperature. The selected area electron diffractions revealed that the Pd4Si nanowire and face-centered-cubic Co nanowire on top of the Pd nanowire were encapsulated within the bottom and tip parts of the multiwall CNT, respectively. Although the strain-induced deformation of graphite walls was observed, the solid-state phases of Pd4Si and Co-Pd remain even at above their expected melting temperatures and up to 1,550 ± 50°C. Finally, the encapsulated metals were melted and flowed out from the tip of the CNT after 2 h at the same temperature due to the increase of internal pressure of the CNT.

  11. Planetesimal core formation with partial silicate melting using in-situ high P, high T, deformation x-ray microtomography

    Science.gov (United States)

    Anzures, B. A.; Watson, H. C.; Yu, T.; Wang, Y.

    2017-12-01

    Differentiation is a defining moment in formation of terrestrial planets and asteroids. Smaller planetesimals likely didn't reach high enough temperatures for widescale melting. However, we infer that core formation must have occurred within a few million years from Hf-W dating. In lieu of a global magma ocean, planetesimals likely formed through inefficient percolation. Here, we used in-situ high temperature, high pressure, x-ray microtomography to track the 3-D evolution of the sample at mantle conditions as it underwent shear deformation. Lattice-Boltzmann simulations for permeability were used to characterize the efficiency of melt percolation. Mixtures of KLB1 peridotite plus 6.0 to 12.0 vol% FeS were pre-sintered to achieve an initial equilibrium microstructure, and then imaged through several consecutive cycles of heating and deformation. The maximum calculated melt segregation velocity was found to be 0.37 cm/yr for 6 vol.% FeS and 0.61 cm/year for 12 vol.% FeS, both below the minimum velocity of 3.3 cm/year required for a 100km planetesimal to fully differentiate within 3 million years. However, permeability is also a function of grain size and thus the samples having smaller grains than predicted for small planetesimals could have contributed to low permeability and also low migration velocity. The two-phase (sulfide melt and silicate melt) flow at higher melt fractions (6 vol.% and 12 vol.% FeS) was an extension of a similar study1 containing only sulfide melt at lower melt fraction (4.5 vol.% FeS). Contrary to the previous study, deformation did result in increased permeability until the sample was sheared by twisting the opposing Drickamer anvils by 360 degrees. Also, the presence of silicate melt caused the FeS melt to coalesce into less connected pathways as the experiment with 6 vol.% FeS was found to be less permeable than the one with 4.5 vol.% FeS but without any partial melt. The preliminary data from this study suggests that impacts as well as

  12. High-sensitivity mass spectrometry with a tandem accelerator

    International Nuclear Information System (INIS)

    Henning, W.

    1984-01-01

    The characteristic features of accelerator mass spectrometry are discussed. A short overview is given of the current status of mass spectrometry with high-energy (MeV/nucleon) heavy-ion accelerators. Emphasis is placed on studies with tandem accelerators and on future mass spectrometry of heavier isotopes with the new generation of higher-voltage tandems

  13. Correcting systematic errors in high-sensitivity deuteron polarization measurements

    NARCIS (Netherlands)

    Brantjes, N. P. M.; Dzordzhadze, V.; Gebel, R.; Gonnella, F.; Gray, F. E.; van der Hoek, D. J.; Imig, A.; Kruithof, W. L.; Lazarus, D. M.; Lehrach, A.; Lorentz, B.; Messi, R.; Moricciani, D.; Morse, W. M.; Noid, G. A.; Onderwater, C. J. G.; Ozben, C. S.; Prasuhn, D.; Sandri, P. Levi; Semertzidis, Y. K.; da Silva e Silva, M.; Stephenson, E. J.; Stockhorst, H.; Venanzoni, G.; Versolato, O. O.

    2012-01-01

    This paper reports deuteron vector and tensor beam polarization measurements taken to investigate the systematic variations due to geometric beam misalignments and high data rates. The experiments used the In-Beam Polarimeter at the KVI-Groningen and the EDDA detector at the Cooler Synchrotron COSY

  14. Variable high pressure processing sensitivities for GII human noroviruses

    Science.gov (United States)

    Human norovirus (HuNoV) is the leading cause of foodborne diseases worldwide. High pressure processing (HPP) is one of the most promising non-thermal technologies for decontamination of viral pathogens in foods. However, the survival of HuNoVs by HPP is poorly understood because these viruses cann...

  15. Advantages of the in-situ LTP distortion profile test on high-heat-load mirrors and applications

    International Nuclear Information System (INIS)

    Qian, S.; Jark, W.; Sostero, G.; Gambitta, A.; Mazzolini, F.; Savoia, A.

    1996-01-01

    The first in-situ distortion profile measurement of a high heat load mirror by use of the penta-prism LTP is presented. A maximum height distortion of 0.47 micron in tangential direction over a length of 180 mm was measured for an internally water-cooled mirror of a undulator beam line at ELETTRA while exposed to a total emitted power of 600 W (undulator gap 30 mm and current 180 mA). The experiment has an accuracy and repeatability of 0.04 micron. The test schematic and the test equipment are presented. Two measuring methods to scan a penta-prism being installed either outside or inside the vacuum chamber are introduced. Advantages and some possible applications of adopting the penta-prism LTP to make the in-situ profile test are explained

  16. High Sensitivity Indium Phosphide Based Avalanche Photodiode Focal Plane Arrays, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — nLight has demonstrated highly-uniform APD arrays based on the highly sensitive InGaAs/InP material system. These results provide great promise for achieving the...

  17. Cluster tool for in situ processing and comprehensive characteriza tion of thin films at high temperatures.

    Science.gov (United States)

    Wenisch, Robert; Lungwitz, Frank; Hanf, Daniel; Heller, Rene; Zscharschuch, Jens; Hübner, René; von Borany, Johannes; Abrasonis, Gintautas; Gemming, Sibylle; Escobar-Galindo, Ramon; Krause, Matthias

    2018-05-31

    A new cluster tool for in situ real-time processing and depth-resolved compositional, structural and optical characterization of thin films at temperatures from -100 to 800 °C is described. The implemented techniques comprise magnetron sputtering, ion irradiation, Rutherford backscattering spectrometry, Raman spectroscopy and spectroscopic ellipsometry. The capability of the cluster tool is demonstrated for a layer stack MgO/ amorphous Si (~60 nm)/ Ag (~30 nm), deposited at room temperature and crystallized with partial layer exchange by heating up to 650°C. Its initial and final composition, stacking order and structure were monitored in situ in real time and a reaction progress was defined as a function of time and temperature.

  18. Mass Spectrometry-based Assay for High Throughput and High Sensitivity Biomarker Verification

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Xuejiang; Tang, Keqi

    2017-06-14

    Searching for disease specific biomarkers has become a major undertaking in the biomedical research field as the effective diagnosis, prognosis and treatment of many complex human diseases are largely determined by the availability and the quality of the biomarkers. A successful biomarker as an indicator to a specific biological or pathological process is usually selected from a large group of candidates by a strict verification and validation process. To be clinically useful, the validated biomarkers must be detectable and quantifiable by the selected testing techniques in their related tissues or body fluids. Due to its easy accessibility, protein biomarkers would ideally be identified in blood plasma or serum. However, most disease related protein biomarkers in blood exist at very low concentrations (<1ng/mL) and are “masked” by many none significant species at orders of magnitude higher concentrations. The extreme requirements of measurement sensitivity, dynamic range and specificity make the method development extremely challenging. The current clinical protein biomarker measurement primarily relies on antibody based immunoassays, such as ELISA. Although the technique is sensitive and highly specific, the development of high quality protein antibody is both expensive and time consuming. The limited capability of assay multiplexing also makes the measurement an extremely low throughput one rendering it impractical when hundreds to thousands potential biomarkers need to be quantitatively measured across multiple samples. Mass spectrometry (MS)-based assays have recently shown to be a viable alternative for high throughput and quantitative candidate protein biomarker verification. Among them, the triple quadrupole MS based assay is the most promising one. When it is coupled with liquid chromatography (LC) separation and electrospray ionization (ESI) source, a triple quadrupole mass spectrometer operating in a special selected reaction monitoring (SRM) mode

  19. In Situ Balloon-Borne Ice Particle Imaging in High-Latitude Cirrus

    Science.gov (United States)

    Kuhn, Thomas; Heymsfield, Andrew J.

    2016-09-01

    Cirrus clouds reflect incoming solar radiation, creating a cooling effect. At the same time, these clouds absorb the infrared radiation from the Earth, creating a greenhouse effect. The net effect, crucial for radiative transfer, depends on the cirrus microphysical properties, such as particle size distributions and particle shapes. Knowledge of these cloud properties is also needed for calibrating and validating passive and active remote sensors. Ice particles of sizes below 100 µm are inherently difficult to measure with aircraft-mounted probes due to issues with resolution, sizing, and size-dependent sampling volume. Furthermore, artefacts are produced by shattering of particles on the leading surfaces of the aircraft probes when particles several hundred microns or larger are present. Here, we report on a series of balloon-borne in situ measurements that were carried out at a high-latitude location, Kiruna in northern Sweden (68N 21E). The method used here avoids these issues experienced with the aircraft probes. Furthermore, with a balloon-borne instrument, data are collected as vertical profiles, more useful for calibrating or evaluating remote sensing measurements than data collected along horizontal traverses. Particles are collected on an oil-coated film at a sampling speed given directly by the ascending rate of the balloon, 4 m s-1. The collecting film is advanced uniformly inside the instrument so that an always unused section of the film is exposed to ice particles, which are measured by imaging shortly after sampling. The high optical resolution of about 4 µm together with a pixel resolution of 1.65 µm allows particle detection at sizes of 10 µm and larger. For particles that are 20 µm (12 pixel) in size or larger, the shape can be recognized. The sampling volume, 130 cm3 s-1, is well defined and independent of particle size. With the encountered number concentrations of between 4 and 400 L-1, this required about 90- to 4-s sampling times to

  20. Sacrificial Protective Coating Materials that can be Regenerated In-Situ to Enable High Performance Membranes

    Energy Technology Data Exchange (ETDEWEB)

    Malati, Peter; Ganguli, Rahul; Mehrotra, Vivek

    2018-03-20

    In the pulp and paper industry, weak black liquor concentration is carried out using energy intensive evaporators. Briefly, after wood digestion, water is evaporated to concentrate weak black liquor to the point where the black liquor can be burned in a recovery boiler, which ultimately leads to the recovery of digestion chemicals. Because it is less energy intensive than heat-driven separation, pressure-driven separation of water from black liquor using membranes could reduce the energy usage by 55 trillion Btu yr-1 and carbon dioxide emissions by more than 11 million metric tons CO2 per year if the first two evaporators are replaced. However, weak black liquor is a hot, corrosive, and highly fouling feed with organic molecules, colloids, and ions that clog membranes within hours of operation. We have shown that membrane-based concentration of weak black liquor is feasible, but only with our antifouling and anti-clogging technology that is based on a sacrificial Bio-inspired Living Skin concept. This concept is based on a conformal coating that is formed at the membrane surface and within the pores. Weak foulant adhesion dramatically decreases membrane fouling while the superhydrophilicity of the coating increases the water permeability. Moreover, the coating can be completely removed during backflushing, which removes foulants that may irreversibly adhere to the coating over long periods of time. The skin shedding completely regenerates the membrane surface and pores, restoring the original flux. This is followed by in-situ recoating, using the existing membrane plumbing and pumps, which essentially creates a brand new membrane surface. Our coatings resist fouling under hot weak black liquor concentration conditions and can be regenerated in-situ on demand. Weak black liquor permeate flux as well as Fourier-transform infrared spectroscopy results suggest that black liquor foulants adhere very weakly to coated membrane surfaces. We modified the coating process to

  1. Self-powered neutron detector of high sensitivity

    International Nuclear Information System (INIS)

    Brixy, H.; Spillekothen, H.G.; Benninghofen, G.; Serafin, N.

    1983-01-01

    A self-powered neutron detector is proposed, consisting of three concentrically arranged electrically conducting tubes; where the central one forms the emitter and the inner and outer ones form the collector and where the tubes are electrically insulated from each other by insulating material. The emitter consists of a material with a high absorption cross-section for thermal neutrons, particularly of gadolinium, and is provided with an auxiliary emitter layer on the inside or the outside. With suitable dimensions and material, the auxiliary emitter layer increases the yield of electrons. (orig./HP) [de

  2. An Underwater Acoustic Vector Sensor with High Sensitivity and Broad Band

    Directory of Open Access Journals (Sweden)

    Hu Zhang

    2014-05-01

    Full Text Available Recently, acoustic vector sensor that use accelerators as sensing elements are widely used in underwater acoustic engineering, but the sensitivity of which at low frequency band is usually lower than -220 dB. In this paper, using a piezoelectric trilaminar optimized low frequency sensing element, we designed a high sensitivity internal placed ICP piezoelectric accelerometer as sensing element. Through structure optimization, we made a high sensitivity, broadband, small scale vector sensor. The working band is 10-2000 Hz, sound pressure sensitivity is -185 dB (at 100 Hz, outer diameter is 42 mm, length is 80 mm.

  3. Serine Protease Zymography: Low-Cost, Rapid, and Highly Sensitive RAMA Casein Zymography.

    Science.gov (United States)

    Yasumitsu, Hidetaro

    2017-01-01

    To detect serine protease activity by zymography, casein and CBB stain have been used as a substrate and a detection procedure, respectively. Casein zymography has been using substrate concentration at 1 mg/mL and employing conventional CBB stain. Although ordinary casein zymography provides reproducible results, it has several disadvantages including time-consuming and relative low sensitivity. Improved casein zymography, RAMA casein zymography, is rapid and highly sensitive. RAMA casein zymography completes the detection process within 1 h after incubation and increases the sensitivity at least by tenfold. In addition to serine protease, the method also detects metalloprotease 7 (MMP7, Matrilysin) with high sensitivity.

  4. Highly sensitive determination of atropine using cobalt oxide nanostructures: Influence of functional groups on the signal sensitivity

    Energy Technology Data Exchange (ETDEWEB)

    Soomro, Razium Ali, E-mail: raziumsoomro@gmail.com [Interface Analysis Centre, School of Physics, University of Bristol, Bristol, BS8 1TL (United Kingdom); National Centre of Excellence in Analytical Chemistry, University of Sindh, Jamshoro, 76080 (Pakistan); Nafady, Ayman [Department of Chemistry, College of Science, King Saud University, Riyadh (Saudi Arabia); Department of Chemistry, Faculty of Science, Sohag University, Sohag (Egypt); Hallam, Keith Richard [Interface Analysis Centre, School of Physics, University of Bristol, Bristol, BS8 1TL (United Kingdom); Jawaid, Sana [National Centre of Excellence in Analytical Chemistry, University of Sindh, Jamshoro, 76080 (Pakistan); Al Enizi, Abdullah [Department of Chemistry, College of Science, King Saud University, Riyadh (Saudi Arabia); Sherazi, Syed Tufail Hussain; Sirajuddin [National Centre of Excellence in Analytical Chemistry, University of Sindh, Jamshoro, 76080 (Pakistan); Ibupoto, Zafar Hussain [Dr M.A. Kazi Institute of Chemistry, University of Sindh, Jamshoro, 76080 (Pakistan); Willander, Magnus [Department of Science and Technology, Campus Norrkoping, Linkoping University, SE-60174, Norrkoping (Sweden)

    2016-12-15

    This study describes sensitive determination of atropine using glassy carbon electrodes (GCE) modified with Co{sub 3}O{sub 4} nanostructures. The as-synthesised nanostructures were grown using cysteine (CYS), glutathione (GSH) and histidine (HYS) as effective templates under hydrothermal action. The obtained morphologies revealed interesting structural features, including both cavity-based and flower-shaped structures. The as-synthesised morphologies were noted to actively participate in electro-catalysis of atropine (AT) drug where GSH-assisted structures exhibited the best signal response in terms of current density and over-potential value. The study also discusses the influence of functional groups on the signal sensitivity of atropine electro-oxidation. The functionalisation was carried with the amino acids originally used as effective templates for the growth of Co{sub 3}O{sub 4} nanostructures. The highest increment was obtained when GSH was used as the surface functionalising agent. The GSH-functionalised Co{sub 3}O{sub 4}-modified electrode was utilised for the electro-chemical sensing of AT in a concentration range of 0.01–0.46 μM. The developed sensor exhibited excellent working linearity (R{sup 2} = 0.999) and signal sensitivity up to 0.001 μM of AT. The noted high sensitivity of the sensor is associated with the synergy of superb surface architectures and favourable interaction facilitating the electron transfer kinetics for the electro-catalytic oxidation of AT. Significantly, the developed sensor demonstrated excellent working capability when used for AT detection in human urine samples with strong anti-interference potential against common co-existing species, such as glucose, fructose, cysteine, uric acid, dopamine and ascorbic acid. - Highlights: • Template-assisted growth of Co{sub 3}O{sub 4} nanostructures. • Shape-dependent electro-catalysis of atropine. • Effect of functionalisation of signal sensitivity.

  5. High-speed asynchronous optical sampling for high-sensitivity detection of coherent phonons

    International Nuclear Information System (INIS)

    Dekorsy, T; Taubert, R; Hudert, F; Schrenk, G; Bartels, A; Cerna, R; Kotaidis, V; Plech, A; Koehler, K; Schmitz, J; Wagner, J

    2007-01-01

    A new optical pump-probe technique is implemented for the investigation of coherent acoustic phonon dynamics in the GHz to THz frequency range which is based on two asynchronously linked femtosecond lasers. Asynchronous optical sampling (ASOPS) provides the performance of on all-optical oscilloscope and allows us to record optically induced lattice dynamics over nanosecond times with femtosecond resolution at scan rates of 10 kHz without any moving part in the set-up. Within 1 minute of data acquisition time signal-to-noise ratios better than 10 7 are achieved. We present examples of the high-sensitivity detection of coherent phonons in superlattices and of the coherent acoustic vibration of metallic nanoparticles

  6. High-precision high-sensitivity clock recovery circuit for a mobile payment application

    International Nuclear Information System (INIS)

    Sun Lichong; Yan Na; Min Hao; Ren Wenliang

    2011-01-01

    This paper presents a fully integrated carrier clock recovery circuit for a mobile payment application. The architecture is based on a sampling-detection module and a charge pump phase locked loop. Compared with clock recovery in conventional 13.56 MHz transponders, this circuit can recover a high-precision consecutive carrier clock from the on/off keying (OOK) signal sent by interrogators. Fabricated by a SMIC 0.18-μm EEPROM CMOS process, this chip works from a single power supply as low as 1.5 V Measurement results show that this circuit provides 0.34% frequency deviation and 8 mV sensitivity. (semiconductor integrated circuits)

  7. A highly sensitive method for quantification of iohexol

    DEFF Research Database (Denmark)

    Schulz, A.; Boeringer, F.; Swifka, J.

    2014-01-01

    -chromatography-electrospray-massspectrometry (LC-ESI-MS) approach using the multiple reaction monitoring mode for iohexol quantification. In order to test whether a significantly decreased amount of iohexol is sufficient for reliable quantification, a LC-ESI-MS approach was assessed. We analyzed the kinetics of iohexol in rats after application...... of different amounts of iohexol (15 mg to 150 1.tg per rat). Blood sampling was conducted at four time points, at 15, 30, 60, and 90 min, after iohexol injection. The analyte (iohexol) and the internal standard (iotha(amic acid) were separated from serum proteins using a centrifugal filtration device...... with a cut-off of 3 kDa. The chromatographic separation was achieved on an analytical Zorbax SB C18 column. The detection and quantification were performed on a high capacity trap mass spectrometer using positive ion ESI in the multiple reaction monitoring (MRM) mode. Furthermore, using real-time polymerase...

  8. High Quality Rapeseed Products as Feed for Sensitive Monogastrics

    DEFF Research Database (Denmark)

    Frandsen, Heidi Blok

    in plants of the order Brassicales (former known as Capparales), which include rapeseed, rype (Brassica campestris L.) Indian mustard (Brassica juncea L.), broccoli (Brassica oleracea L.var. italica) and many other plants. Glucosinolates have been studied widely for their biologic effects ranging from...... by xenobiotica enzymes in the liver. The last study (manuscript IV) deals with the novel processing techniques, pulsed electric field (PEF) and high pressure treatment (HPT) and the processing effects on glucosinolates in broccoli. The largest effects were observed to be a result of the different handling...... of the plant materials prior to the process treatment. It was thus found that a great amount of the glucosinolate loss has occurred in the broccoli juice and purée prior to PEF processing. Only a minor loss was observed in broccoli flowers prior to processing, and HP treatment at 700 MPa for 10 min. was found...

  9. Silicon nanowire structures as high-sensitive pH-sensors

    International Nuclear Information System (INIS)

    Belostotskaya, S O; Chuyko, O V; Kuznetsov, A E; Kuznetsov, E V; Rybachek, E N

    2012-01-01

    Sensitive elements for pH-sensors created on silicon nanostructures were researched. Silicon nanostructures have been used as ion-sensitive field effect transistor (ISFET) for the measurement of solution pH. Silicon nanostructures have been fabricated by 'top-down' approach and have been studied as pH sensitive elements. Nanowires have the higher sensitivity. It was shown, that sensitive element, which is made of 'one-dimensional' silicon nanostructure have bigger pH-sensitivity as compared with 'two-dimensional' structure. Integrated element formed from two p- and n-type nanowire ISFET ('inverter') can be used as high sensitivity sensor for local relative change [H+] concentration in very small volume.

  10. A novel high resolution, high sensitivity SPECT detector for molecular imaging of cardiovascular diseases

    Science.gov (United States)

    Cusanno, F.; Argentieri, A.; Baiocchi, M.; Colilli, S.; Cisbani, E.; De Vincentis, G.; Fratoni, R.; Garibaldi, F.; Giuliani, F.; Gricia, M.; Lucentini, M.; Magliozzi, M. L.; Majewski, S.; Marano, G.; Musico, P.; Musumeci, M.; Santavenere, F.; Torrioli, S.; Tsui, B. M. W.; Vitelli, L.; Wang, Y.

    2010-05-01

    Cardiovascular diseases are the most common cause of death in western countries. Understanding the rupture of vulnerable atherosclerotic plaques and monitoring the effect of innovative therapies of heart failure is of fundamental importance. A flexible, high resolution, high sensitivity detector system for molecular imaging with radionuclides on small animal models has been designed for this aim. A prototype has been built using tungsten pinhole and LaBr3(Ce) scintillator coupled to Hamamatsu Flat Panel PMTs. Compact individual-channel readout has been designed, built and tested. Measurements with phantoms as well as pilot studies on mice have been performed, the results show that the myocardial perfusion in mice can be determined with sufficient precision. The detector will be improved replacing the Hamamatsu Flat Panel with Silicon Photomultipliers (SiPMs) to allow integration of the system with MRI scanners. Application of LaBr3(Ce) scintillator coupled to photosensor with high photon detection efficiency and excellent energy resolution will allow dual-label imaging to monitor simultaneously the cardiac perfusion and the molecular targets under investigation during the heart therapy.

  11. In-situ deposition of YBCO high-Tc superconducting thin films by MOCVD and PE-MOCVD

    International Nuclear Information System (INIS)

    Zhao, J.; Noh, D.W.; Chern, C.; Li, Y.Q.; Norris, P.E.; Kear, B.; Gallois, B.

    1991-01-01

    Metal-Organic Chemical Vapor Deposition (MOCVD) offers the advantages of a high degree of compositional control, adaptability for large scale production, and the potential for low temperature fabrication. The capability of operating at high oxygen partial pressure is particularly suitable for in situ formation of high temperature superconducting (HTSC) films. Yttrium barium copper oxide (YBCO) thin films having a sharp zero-resistance transition with T(sub c) greater than 90 K and J(sub c) of approximately 10(exp 4) A on YSZ have been prepared, in situ, at a substrate temperature of about 800 C. Moreover, the ability to form oxide films at low temperature is very desirable for device applications of HTSC materials. Such a process would permit the deposition of high quality HTSC films with a smooth surface on a variety of substrates. Highly c-axis oriented, dense, scratch resistant, superconducting YBCO thin films with mirror-like surfaces have been prepared, in situ, at a reduced substrate temperature as low as 570 C by a remote microwave-plasma enhanced metal-organic chemical vapor deposition (PE-MOCVD) process. Nitrous oxide was used as a reactant gas to generate active oxidizing species. This process, for the first time, allows the formation of YBCO thin films with the orthorhombic superconducting phase in the as-deposited state. The as-deposited films grown by PE-MOCVD show attainment of zero resistance at 72 K with a transition width of about 5 K. MOCVD was carried out in a commercial production scale reactor with the capability of uniform deposition over 100 sq cm per growth run. Preliminary results indicate that PE-MOCVD is a very attractive thin film deposition process for superconducting device technology

  12. The in-situ testing of high efficiency particulate filters in the CEGB south eastern region nuclear power stations

    International Nuclear Information System (INIS)

    Powell, A.W.; Wilkinson, B.A.

    1977-01-01

    High efficiency air filters are installed in the CEGB's Nuclear Power Stations to prevent discharge of radioactive material to the environment should the ventilation air become contaminated. The Board has determined that these filter units should be tested in-situ to ensure that the stringent design specifications are met. This paper describes the rig work comparing the British Standard method using sodium chloride aerosol with other test methods, such as Dioctyl Phthalate, naturally occurring dust aerosols and artificially produced condensation nuclei. This work led to the development of an in-situ test method using condensation nuclei and a Pollak-Nolan nucleus counter. The advantages and disadvantages of this method over other methods for in-situ testing is discussed. The test method has been used in the South Eastern Region for several years and considerable experience has been gained in its use on a wide variety of filter systems. The method adopted for each system is detailed including the injection, sampling and interpretation of the results obtained. Numerous faults and difficulties have been highlighted from the design, installation and filter changing aspects

  13. Nanowire-templated microelectrodes for high-sensitivity pH detection

    DEFF Research Database (Denmark)

    Antohe, V.A.; Radu, Adrian; Mátéfi-Tempfli, Mária

    2009-01-01

    A highly sensitive pH capacitive sensor has been designed by confined growth of vertically aligned nanowire arrays on interdigited microelectrodes. The active surface of the device has been functionalized with an electrochemical pH transducer (polyaniline). We easily tune the device features...... by combining lithographic techniques with electrochemical synthesis. The reported electrical LC resonance measurements show considerable sensitivity enhancement compared to conventional capacitive pH sensors realized with microfabricated interdigited electrodes. The sensitivity can be easily improved...

  14. Eating high-fat chow enhances sensitization to the effects of methamphetamine on locomotion in rats.

    Science.gov (United States)

    McGuire, Blaine A; Baladi, Michelle G; France, Charles P

    2011-05-11

    Eating high-fat chow can modify the effects of drugs acting directly or indirectly on dopamine systems and repeated intermittent drug administration can markedly increase sensitivity (i.e., sensitization) to the behavioral effects of indirect-acting dopamine receptor agonists (e.g., methamphetamine). This study examined whether eating high-fat chow alters the sensitivity of male Sprague Dawley rats to the locomotor stimulating effects of acute or repeated administration of methamphetamine. The acute effects of methamphetamine on locomotion were not different between rats (n=6/group) eating high-fat or standard chow for 1 or 4 weeks. Sensitivity to the effects of methamphetamine (0.1-10mg/kg, i.p.) increased progressively across 4 once per week tests; this sensitization developed more rapidly and to a greater extent in rats eating high-fat chow as compared with rats eating standard chow. Thus, while eating high-fat chow does not appear to alter sensitivity of rats to acutely-administered methamphetamine, it significantly increases the sensitization that develops to repeated intermittent administration of methamphetamine. These data suggest that eating certain foods influences the development of sensitization to drugs acting on dopamine systems. Copyright © 2011 Elsevier B.V. All rights reserved.

  15. First in-situ measurements of a highly fragmented comet: ACE SWICS and WIND STICS measurements

    Science.gov (United States)

    Lepri, S. T.; Gilbert, J. A.; Rubin, M.; Zurbuchen, T.; Combi, M. R.

    2011-12-01

    While many of the characteristics of comets and their local plasma environment are obtained using remote sensing via spectroscopic methods, space-based mass spectrometers allow a unique opportunity to directly sample cometary material in situ. To date there have been only a handful of in-situ spacecraft encounters with comets, such as 1P/Halley, 103P/Hartley, 81P/Wild and others. Comet 73P/Schwassmann-Wachmann started to disintegrate in 1995, two major components B and C were recovered in 2001, and it burst into more than 36 pieces during its passage near the Earth in 2006. Serendipitously, some very distant fragmentation members, well-separated from the major identified fragments, passed between the Earth and Sun. Cometary pickup ions and possibly recombined solar wind minor ions convected past the Earth in late May 2006 and were observed by both the ACE/SWICS and WIND/STICS mass spectrometers, which are located in halo orbits around the Earth-Sun L1 Lagrange point. Most of these observations took place a few days after the main comet fragments passed through the ecliptic, when their orbits crossed the spacecraft-Sun line, suggesting additional pieces lagging far behind the main fragments. In this paper, we present the first in-situ observation of these pieces that passed very close to the spacecraft (<0.07AU) and conduct a comparative analysis of composition and characteristics of pick-up ions originating from a number of the cometary fragments. We find that the pick-up ion trail related to the comet fragments is much longer than expected. We constrain the C+/O+ and He+/He++ ratio and discuss the implications for the production rates of different fragments.

  16. CONSTRUCTION OF A DIFFERENTIAL ISOTHERMAL CALORIMETER OF HIGH SENSITIVITY AND LOW COST.

    OpenAIRE

    Trinca, RB; Perles, CE; Volpe, PLO

    2009-01-01

    CONSTRUCTION OF A DIFFERENTIAL ISOTHERMAL CALORIMETER OF HIGH SENSITIVITY AND LOW COST The high cost of sensitivity commercial calorimeters may represent an obstacle for many calorimetric research groups. This work describes (fie construction and calibration of a batch differential heat conduction calorimeter with sample cells volumes of about 400 mu L. The calorimeter was built using two small high sensibility square Peltier thermoelectric sensors and the total cost was estimated to be about...

  17. In-situ preparation of Fe2O3 hierarchical arrays on stainless steel substrate for high efficient catalysis

    International Nuclear Information System (INIS)

    Yang, Zeheng; Wang, Kun; Shao, Zongming; Tian, Yuan; Chen, Gongde; Wang, Kai; Chen, Zhangxian; Dou, Yan; Zhang, Weixin

    2017-01-01

    Hierarchical array catalysts with micro/nano structures on substrates not only possess high reactivity from large surface area and suitable interface, but intensify mass transfer through shortening the diffusion paths of both reactants and products for high catalytic efficiency. Herein, we first demonstrate fabrication of Fe 2 O 3 hierarchical arrays grown on stainless-steel substrates via in-situ hydrothermal chemical oxidation followed by heat treatment in N 2 atmosphere. As a Fenton-like catalyst, Fe 2 O 3 hierarchical arrays exhibit excellent catalytic activity and life cycle performance for methylene blue (MB) dye degradation in aqueous solution in the presence of H 2 O 2 . The Fe 2 O 3 catalyst with unique hierarchical structures and efficient transport channels, effectively activates H 2 O 2 to generate large quantity of • OH radicals and highly promotes reaction kinetics between MB and • OH radicals. Immobilization of hierarchical array catalysts on stainless-steel can prevent particles agglomeration, facilitate the recovery and reuse of the catalysts, which is expected promising applications in wastewater remediation. - Graphical abstract: The in-situ synthesis of Fe 2 O 3 hierarchical arrays on stainless-steel substrates was reported for the first time, which exhibit excellent catalytic activity performance for methylene blue (MB) dye degradation in aqueous solution in the presence of H 2 O 2 . - Highlights: • Fe 2 O 3 hierarchical arrays was prepared by in-situ hydrothermal chemical oxidation. • F − ions play an important role in the formation of the Fe 2 O 3 hierarchical arrays. • Fe 2 O 3 hierarchical arrays show high catalytic activity to methylene blue degradation.

  18. In situ observation of low temperature growth of Ge on Si(1 1 1) by reflection high energy electron diffraction

    International Nuclear Information System (INIS)

    Grimm, Andreas; Fissel, Andreas; Bugiel, Eberhard; Wietler, Tobias F.

    2016-01-01

    Highlights: • Investigation of the initial stages of epitaxial growth of Ge on Si(1 1 1) in situ by RHEED. • Impact of growth temperature on strain evolution for temperatures between 200 °C and 400 °C. • Epitaxy with a high degree of structural perfection already at growth temperature of 200 °C. • Ordered interfacial dislocation networks already at 200 °C. • Tensile strain contribution of Si(1 1 1) 7 × 7-surface reconstruction to strain relaxation process for epitaxial growth of Ge. - Abstract: In this paper we investigate the initial stages of epitaxial growth of Ge on Si(1 1 1) and the impact of growth temperature on strain evolution in situ by reflection high energy electron diffraction (RHEED) for temperatures between 200 °C and 400 °C. The change in surface morphology from a flat wetting layer to subsequent islanding that is characteristic for Stranski–Krastanov growth is monitored by spot intensity analysis. The corresponding critical layer thickness is determined to 3.1 < d c < 3.4 ML. In situ monitoring of the strain relaxation process reveals a contribution of the Si(1 1 1) 7 × 7-surface reconstruction to the strain relaxation process. High resolution transmission electron microscopy confirms that the Ge islands exhibit a high degree of structural perfection and an ordered interfacial misfit dislocation network already at a growth temperature of 200 °C is established. The temperature dependency of island shape, density and height is characterized by atomic force microscopy and compared to the RHEED investigations.

  19. Source term estimation based on in-situ gamma spectrometry using a high purity germanium detector

    International Nuclear Information System (INIS)

    Pauly, J.; Rojas-Palma, C.; Sohier, A.

    1997-06-01

    An alternative method to reconstruct the source term of a nuclear accident is proposed. The technique discussed here involves the use of in-situ gamma spectrometry. The validation of the applied methodology has been possible through the monitoring of routine releases of Ar-41 originating at a Belgian site from an air cooled graphite research reactor. This technique provides a quick nuclide specific decomposition of the source term and therefore will be have an enormous potential if implemented in nuclear emergency preparedness and radiological assessments of nuclear accidents during the early phase

  20. High throughput in situ scattering of roll-to-roll coated functional polymer films

    DEFF Research Database (Denmark)

    Andreasen, Jens Wenzel

    2017-01-01

    The development of conjugated polymers for organic electronics and photovoltaics has relied heavily on advanced X-ray scattering techniques almost since the earliest studies in the field. Almost from the beginning, structural studies focused on how the polymers self-organize in thin films......, and the relation between chemical configuration of the polymer, structure and performance. This chapter presents the latest developments where structural analysis is applied as in situ characterization of structure formation during roll-to-roll coating of photoactive layers for solar cells....

  1. Development of the "Highly Sensitive Dog" questionnaire to evaluate the personality dimension "Sensory Processing Sensitivity" in dogs.

    Directory of Open Access Journals (Sweden)

    Maya Braem

    Full Text Available In humans, the personality dimension 'sensory processing sensitivity (SPS', also referred to as "high sensitivity", involves deeper processing of sensory information, which can be associated with physiological and behavioral overarousal. However, it has not been studied up to now whether this dimension also exists in other species. SPS can influence how people perceive the environment and how this affects them, thus a similar dimension in animals would be highly relevant with respect to animal welfare. We therefore explored whether SPS translates to dogs, one of the primary model species in personality research. A 32-item questionnaire to assess the "highly sensitive dog score" (HSD-s was developed based on the "highly sensitive person" (HSP questionnaire. A large-scale, international online survey was conducted, including the HSD questionnaire, as well as questions on fearfulness, neuroticism, "demographic" (e.g. dog sex, age, weight; age at adoption, etc. and "human" factors (e.g. owner age, sex, profession, communication style, etc., and the HSP questionnaire. Data were analyzed using linear mixed effect models with forward stepwise selection to test prediction of HSD-s by the above-mentioned factors, with country of residence and dog breed treated as random effects. A total of 3647 questionnaires were fully completed. HSD-, fearfulness, neuroticism and HSP-scores showed good internal consistencies, and HSD-s only moderately correlated with fearfulness and neuroticism scores, paralleling previous findings in humans. Intra- (N = 447 and inter-rater (N = 120 reliabilities were good. Demographic and human factors, including HSP score, explained only a small amount of the variance of HSD-s. A PCA analysis identified three subtraits of SPS, comparable to human findings. Overall, the measured personality dimension in dogs showed good internal consistency, partial independence from fearfulness and neuroticism, and good intra- and inter

  2. Differential sensitivity of long-sleep and short-sleep mice to high doses of cocaine.

    Science.gov (United States)

    de Fiebre, C M; Ruth, J A; Collins, A C

    1989-12-01

    The cocaine sensitivity of male and female long-sleep (LS) and short-sleep (SS) mice, which have been selectively bred for differential ethanol-induced "sleep-time," was examined in a battery of behavioral and physiological tests. Differences between these two mouse lines were subtle and were seen primarily at high doses. At high doses, SS mice were more sensitive than LS mice, particularly to cocaine-induced hypothermia; however, significant hypothermia was not seen except at doses which were very near to the seizure threshold. During a 60-min test of locomotor activity, LS mice showed greater stimulation of Y-maze activity by 20 mg/kg cocaine than SS mice. Consistent with the finding of subtle differences in sensitivity to low doses of cocaine. LS and SS mice did not differ in sensitivity to cocaine inhibition of synaptosomal uptake of [3H]-dopamine, [3H]-norepinephrine or [3H]-5-hydroxytryptamine. However, consistent with the finding of differential sensitivity to high doses of cocaine, SS mice were more sensitive to the seizure-producing effects of the cocaine and lidocaine, a local anesthetic. It is hypothesized that the differential sensitivity of these mouse lines to high doses of cocaine is due to differential sensitivity to cocaine's actions on systems that regulate local anesthetic effects. Selective breeding for differential duration of alcohol-induced "sleep-time" may have resulted in differential ion channel structure or function in these mice.

  3. Organic dye for highly efficient solid-state dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt-Mende, L.; Bach, U.; Humphry-Baker, R.; Ito, S.; Graetzel, M. [Institut des Sciences et Ingenierie Chimiques (ISIC), Laboratoire de Photonique et Interfaces (LPI), Ecole Polytechnique Federale de Lausanne (EPFL), CH-1015 Lausanne (Switzerland); Horiuchi, T.; Miura, H. [Technology Research Laboratory, Corporate Research Center, Mitsubishi Paper Mills Limited, 46, Wadai, Tsukuba City, Ibaraki 300-4247 (Japan); Uchida, S. [Institute of Multidisciplinary Research for Advanced Materials (IMRAM), Tohoku University, 1-1 Katahira 2-chome, Aoba-ku, Sendai 980-8577 (Japan)

    2005-04-04

    The feasibility of solid-state dye-sensitized solar cells as a low-cost alternative to amorphous silicon cells is demonstrated. Such a cell with a record efficiency of over 4 % under simulated sunlight is reported, made possible by using a new organic metal-free indoline dye as the sensitizer with high absorption coefficient. (Abstract Copyright [2005], Wiley Periodicals, Inc.)

  4. In situ derivatization-ultrasound-assisted dispersive liquid-liquid microextraction for the determination of neurotransmitters in Parkinson's rat brain microdialysates by ultra high performance liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    He, Yongrui; Zhao, Xian-En; Zhu, Shuyun; Wei, Na; Sun, Jing; Zhou, Yubi; Liu, Shu; Liu, Zhiqiang; Chen, Guang; Suo, Yourui; You, Jinmao

    2016-08-05

    Simultaneous monitoring of several neurotransmitters (NTs) linked to Parkinson's disease (PD) has important scientific significance for PD related pathology, pharmacology and drug screening. A new simple, fast and sensitive analytical method, based on in situ derivatization-ultrasound-assisted dispersive liquid-liquid microextraction (in situ DUADLLME) in a single step, has been proposed for the quantitative determination of catecholamines and their biosynthesis precursors and metabolites in rat brain microdialysates. The method involved the rapid injection of the mixture of low toxic bromobenzene (extractant) and acetonitrile (dispersant), which containing commercial Lissamine rhodamine B sulfonyl chloride (LRSC) as derivatization reagent, into the aqueous phase of sample and buffer, and the following in situ DUADLLME procedure. After centrifugation, 50μL of the sedimented phase (bromobenzene) was directly injected for ultra high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) detection in multiple reaction monitoring (MRM) mode. This interesting combination brought the advantages of speediness, simpleness, low matrix effects and high sensitivity in an effective way. Parameters of in situ DUADLLME and UHPLC-MS/MS conditions were all optimized in detail. The optimum conditions of in situ DUADLLME were found to be 30μL of microdialysates, 150μL of acetonitrile containing LRSC, 50μL of bromobenzene and 800μL of NaHCO3-Na2CO3 buffer (pH 10.5) for 3.0min at 37°C. Under the optimized conditions, good linearity was observed with LODs (S/N>3) and LOQs (S/N>10) of LRSC derivatized-NTs in the range of 0.002-0.004 and 0.007-0.015 nmol/L, respectively. It also brought good precision (3.2-12.8%, peak area CVs%), accuracy (94.2-108.6%), recovery (94.5-105.5%) and stability (3.8-8.1%, peak area CVs%) results. Moreover, LRSC derivatization significantly improved chromatographic resolution and MS detection sensitivity of NTs when compared with the

  5. Highly stable and reusable immobilized formate dehydrogenases: Promising biocatalysts for in situ regeneration of NADH

    Directory of Open Access Journals (Sweden)

    Barış Binay

    2016-02-01

    Full Text Available This study aimed to prepare robust immobilized formate dehydrogenase (FDH preparations which can be used as effective biocatalysts along with functional oxidoreductases, in which in situ regeneration of NADH is required. For this purpose, Candida methylica FDH was covalently immobilized onto Immobead 150 support (FDHI150, Immobead 150 support modified with ethylenediamine and then activated with glutaraldehyde (FDHIGLU, and Immobead 150 support functionalized with aldehyde groups (FDHIALD. The highest immobilization yield and activity yield were obtained as 90% and 132%, respectively when Immobead 150 functionalized with aldehyde groups was used as support. The half-life times (t1/2 of free FDH, FDHI150, FDHIGLU and FDHIALD were calculated as 10.6, 28.9, 22.4 and 38.5 h, respectively at 35 °C. FDHI150, FDHIGLU and FDHIALD retained 69, 38 and 51% of their initial activities, respectively after 10 reuses. The results show that the FDHI150, FDHIGLU and FDHIALD offer feasible potentials for in situ regeneration of NADH.

  6. Growth and decay of a two-dimensional oxide quasicrystal: High-temperature in situ microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Foerster, Stefan [Physik-Institut, Universitaet Zuerich (Switzerland); Institute of Physics, Martin-Luther-Universitaet Halle-Wittenberg, Halle (Germany); Flege, Jan Ingo; Falta, Jens [Institute of Solid State Physics, University of Bremen (Germany); MAPEX Center for Materials and Processes, University of Bremen (Germany); Zollner, Eva Maria; Schumann, Florian Otto; Hammer, Rene; Bayat, Alireza; Schindler, Karl-Michael [Institute of Physics, Martin-Luther-Universitaet Halle-Wittenberg, Halle (Germany); Widdra, Wolf [Institute of Physics, Martin-Luther-Universitaet Halle-Wittenberg, Halle (Germany); Max-Planck-Institut fuer Mikrostrukturphysik, Halle (Germany)

    2017-01-15

    The recently discovered two-dimensional oxide quasicrystal (OQC) derived from BaTiO{sub 3} on Pt(111) is the first material in which a spontaneous formation of an aperiodic structure at the interface to a periodic support has been observed. Herein, we report in situ low-energy electron microscopy (LEEM) studies on the fundamental processes involved in the OQC growth. The OQC formation proceeds in two steps via of an amorphous two-dimensional wetting layer. At 1170 K the long-range aperiodic order of the OQC develops. Annealing in O{sub 2} induces the reverse process, the conversion of the OQC into BaTiO{sub 3} islands and bare Pt(111), which has been monitored by in situ LEEM. A quantitative analysis of the temporal decay of the OQC shows that oxygen adsorption on bare Pt patches is the rate limiting step of this dewetting process. (copyright 2016 by WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  7. Simulation on following Performance of High-Speed Railway In Situ Testing System

    Directory of Open Access Journals (Sweden)

    Fei-Long Zheng

    2013-01-01

    Full Text Available Subgrade bears both the weight of superstructures and the impacts of running trains. Its stability affects the line smoothness directly, but in situ testing method on it is inadequate. This paper presents a railway roadbed in situ testing device, the key component of which is an excitation hydraulic servo cylinder that can output the static pressure and dynamic pressure simultaneously to simulate the force of the trains to the subgrade. The principle of the excitation system is briefly introduced, and the transfer function of the closed-loop force control system is derived and simulated; that, it shows without control algorithm, the dynamic response is very low and the following performance is quite poor. So, the improvedadaptive model following control (AMFC algorithm based on direct state method is adopted. Then, control block diagram is built and simulated with the input of different waveforms and frequencies. The simulation results show that the system has been greatly improved; the output waveform can follow the input signal much better except for a little distortion when the signal varies severely. And the following performance becomes even better as the load stiffness increases.

  8. Beamline electrostatic levitator for in situ high energy x-ray diffraction studies of levitated solids and liquids

    Energy Technology Data Exchange (ETDEWEB)

    Gangopadhyay, A.K.; Lee, G.W.; Kelto, K.F.; Rogers, J.R.; Goldman, A.I.; Robinson, D.S.; Rathz, T.J.; Hyers, R.W. (WU); (UAB); (NASA); (UMASS, Amherst)

    2010-07-19

    Determinations of the phase formation sequence, crystal structures and the thermo-physical properties of materials at high temperatures are hampered by contamination from the sample container and environment. Containerless processing techniques, such as electrostatic (ESL), electromagnetic, aerodynamic, and acoustic levitation, are most suitable for these studies. An adaptation of ESL for in situ structural studies of a wide range of materials using high energy (30-130 keV) x rays at a synchrotron source is described here. This beamline ESL (BESL) allows the in situ determination of the atomic structures of equilibrium solid and liquid phases, undercooled liquids and time-resolved studies of solid-solid and liquid-solid phase transformations. The use of area detectors enables the rapid acquisition of complete diffraction patterns over a wide range (0.5-14 {angstrom}{sup -1}) of reciprocal space. The wide temperature range (300-2500 K), containerless processing environment under high vacuum (10{sup -7}-10{sup -8} Torr), and fast data acquisition capability, make BESL particularly well suited for phase stability studies of high temperature solids and liquids. An additional, but important, feature of BESL is the capability for simultaneous measurements of a host of thermo-physical properties including the specific heat, enthalpy of transformation, solidus and liquidus temperatures, density, viscosity, and surface tension, all on the same sample during the structural measurements.

  9. In-situ nanoelectrospray for high-throughput screening of enzymes and real-time monitoring of reactions.

    Science.gov (United States)

    Yang, Yuhan; Han, Feifei; Ouyang, Jin; Zhao, Yunling; Han, Juan; Na, Na

    2016-01-01

    The in-situ and high-throughput evaluation of enzymes and real-time monitoring of enzyme catalyzed reactions in liquid phase is quite significant in the catalysis industry. In-situ nanoelectrospray, the direct sampling and ionization method for mass spectrometry, has been applied for high-throughput evaluation of enzymes, as well as the on-line monitoring of reactions. Simply inserting a capillary into a liquid system with high-voltage applied, analytes in liquid reaction system can be directly ionized at the capillary tip with small volume consumption. With no sample pre-treatment or injection procedure, different analytes such as saccharides, amino acids, alkaloids, peptides and proteins can be rapidly and directly extracted from liquid phase and ionized at the capillary tip. Taking irreversible transesterification reaction of vinyl acetate and ethanol as an example, this technique has been used for the high-throughput evaluation of enzymes, fast optimizations, as well as real-time monitoring of reaction catalyzed by different enzymes. In addition, it is even softer than traditional electrospray ionization. The present method can also be used for the monitoring of other homogenous and heterogeneous reactions in liquid phases, which will show potentials in the catalysis industry. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. Structure of spinel at high temperature using in-situ XANES study at the Al and Mg K-edge

    Energy Technology Data Exchange (ETDEWEB)

    Ligny, D de [Universite Claude Bernard Lyon 1, LPCML, 69622 Villeurbanne (France); Neuville, D R [Physique des Mineraux et Magmas, Geochimie-Cosmochimie, CNRS-IPGP, 4 place Jussieu, 75005 Paris (France); Flank, A-M; Lagarde, P, E-mail: deligny@pcml.univ-lyon1.f [Synchrotron SOLEIL, L' Orme des Merisiers, Saint Aubin, 91192 France (France)

    2009-11-15

    We present structural information obtained on spinel at high temperature (298-2400 K) using in situ XANES at the Mg and Al K-edge. Spinel, {sup [4]}(Al{sub x},Mg{sub 1-x}){sup [6]}(Al{sub 2-x},Mg{sub x})O{sub 4}, with increasing temperature, show a substitution of Mg by Al and Al by Mg in their respective sites. This substitution corresponds to an inversion of the Mg and Al sites. Furthermore, both experiments at the Al and Mg K-edges are in good agreement with XANES calculation made using FDMNES code.

  11. A Rotational and Axial Motion System Load Frame Insert for In Situ High Energy X-Ray Studies (Postprint)

    Science.gov (United States)

    2015-09-08

    Paul A. Shade, Jay C. Schuren, and Todd J. Turner AFRL/RX Basil Blank PulseRay Peter Kenesei, Kurt Goetze, Ulrich Lienert, and Jonathan Almer...AFRL/RX 2) Basil Blank – PulseRay (continued on page 2) 5d. PROJECT NUMBER 4349 5e. TASK NUMBER 0001 5f...2015) A rotational and axial motion system load frame insert for in situ high energy x-ray studies Paul A. Shade,1,a) Basil Blank,2 Jay C. Schuren,1,b

  12. In situ high temperature MAS NMR study of the mechanisms of catalysis. Ethane aromatization on Zn-modified zeolite BEA.

    Science.gov (United States)

    Arzumanov, Sergei S; Gabrienko, Anton A; Freude, Dieter; Stepanov, Alexander G

    2009-04-01

    Ethane conversion into aromatic hydrocarbons over Zn-modified zeolite BEA has been analyzed by high-temperature MAS NMR spectroscopy. Information about intermediates (Zn-ethyl species) and reaction products (mainly toluene and methane), which were formed under the conditions of a batch reactor, was obtained by (13)C MAS NMR. Kinetics of the reaction, which was monitored by (1)H MAS NMR in situ at the temperature of 573K, provided information about the reaction mechanism. Simulation of the experimental kinetics within the frames of the possible kinetic schemes of the reaction demonstrates that a large amount of methane evolved under ethane aromatization arises from the stage of direct ethane hydrogenolysis.

  13. RAMA casein zymography: Time-saving and highly sensitive casein zymography for MMP7 and trypsin.

    Science.gov (United States)

    Yasumitsu, Hidetaro; Ozeki, Yasuhiro; Kanaly, Robert A

    2016-11-01

    To detect metalloproteinase-7 (MMP7), zymography is conducted using a casein substrate and conventional CBB stain. It has disadvantages because it is time consuming and has low sensitivity. Previously, a sensitive method to detect MMP7 up to 30 pg was reported, however it required special substrates and complicated handlings. RAMA casein zymography described herein is rapid, sensitive, and reproducible. By applying high-sensitivity staining with low substrate conditions, the staining process is completed within 1 h and sensitivity was increased 100-fold. The method can detect 10 pg MMP7 by using commercially available casein without complicated handlings. Moreover, it increases detection sensitivity for trypsin. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Prototype of high resolution PET using resistive electrode position sensitive CdTe detectors

    International Nuclear Information System (INIS)

    Kikuchi, Yohei; Ishii, Keizo; Matsuyama, Shigeo; Yamazaki, Hiromichi

    2008-01-01

    Downsizing detector elements makes it possible that spatial resolutions of positron emission tomography (PET) cameras are improved very much. From this point of view, semiconductor detectors are preferable. To obtain high resolution, the pixel type or the multi strip type of semiconductor detectors can be used. However, in this case, there is a low packing ratio problem, because a dead area between detector arrays cannot be neglected. Here, we propose the use of position sensitive semiconductor detectors with resistive electrode. The CdTe detector is promising as a detector for PET camera because of its high sensitivity. In this paper, we report development of prototype of high resolution PET using resistive electrode position sensitive CdTe detectors. We made 1-dimensional position sensitive CdTe detectors experimentally by changing the electrode thickness. We obtained 750 A as an appropriate thickness of position sensitive detectors, and evaluated the performance of the detector using a collimated 241 Am source. A good position resolution of 1.2 mm full width half maximum (FWHM) was obtained. On the basis of the fundamental development of resistive electrode position sensitive detectors, we constructed a prototype of high resolution PET which was a dual head type and was consisted of thirty-two 1-dimensional position sensitive detectors. In conclusion, we obtained high resolutions which are 0.75 mm (FWHM) in transaxial, and 1.5 mm (FWHM) in axial. (author)

  15. High-resistive layers obtained through periodic growth and in situ annealing of InGaN by metalorganic chemical vapor deposition

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Shuo; Ma, Ping, E-mail: maping@semi.ac.cn; Liu, Boting; Wu, Dongxue; Li, Jinmin [Research and Development Center for Solid State Lighting, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083 (China); Huang, Yuliang [Beijing Engineering Research Center for the 3rd Generation Semiconductor Materials and Application, Beijing 100083 (China); Wang, Junxi [State Key Laboratory of Solid State Lighting, Beijing 100083 (China)

    2016-06-15

    High-resistive layers were obtained by periodic growth and in situ annealing of InGaN. The effect of the annealing temperature of InGaN on the indium content and the material sheet resistive was investigated. The indium content decreased as the increase of in situ annealing temperature. Additionally, the material sheet resistance increased with the increase of the in situ annealing temperature for the annealed samples and reached 2 × 10{sup 10}Ω/sq in the light and 2 × 10{sup 11}Ω/sq in the dark when the in situ annealing temperature reached 970{sup ∘}C. The acquirement of high-resistive layers is attributed to the generation of indium vacancy-related defects. Introducing indium vacancy-related defects to compensate background carriers can be an effective method to grow high-resistance material.

  16. High-resistive layers obtained through periodic growth and in situ annealing of InGaN by metalorganic chemical vapor deposition

    International Nuclear Information System (INIS)

    Zhang, Shuo; Ma, Ping; Liu, Boting; Wu, Dongxue; Li, Jinmin; Huang, Yuliang; Wang, Junxi

    2016-01-01

    High-resistive layers were obtained by periodic growth and in situ annealing of InGaN. The effect of the annealing temperature of InGaN on the indium content and the material sheet resistive was investigated. The indium content decreased as the increase of in situ annealing temperature. Additionally, the material sheet resistance increased with the increase of the in situ annealing temperature for the annealed samples and reached 2 × 10"1"0Ω/sq in the light and 2 × 10"1"1Ω/sq in the dark when the in situ annealing temperature reached 970"∘C. The acquirement of high-resistive layers is attributed to the generation of indium vacancy-related defects. Introducing indium vacancy-related defects to compensate background carriers can be an effective method to grow high-resistance material.

  17. Highly sensitive optical chemosensor for the detection of Cu using a ...

    Indian Academy of Sciences (India)

    Administrator

    Highly sensitive colorimetric chemosensor molecule RHN for selective detection of Cu. 2+ in ... colour development against the colourless blank during the sensing event, a feature that would facilitate ... ever reported, much attention has been.

  18. A highly sensitive, low-cost, wearable pressure sensor based on conductive hydrogel spheres

    KAUST Repository

    Tai, Yanlong; Mulle, Matthieu; Ventura, Isaac Aguilar; Lubineau, Gilles

    2015-01-01

    Wearable pressure sensing solutions have promising future for practical applications in health monitoring and human/machine interfaces. Here, a highly sensitive, low-cost, wearable pressure sensor based on conductive single-walled carbon nanotube

  19. A new method of removing the high value feedback resistor in the charge sensitive preamplifier

    International Nuclear Information System (INIS)

    Xi Deming

    1993-01-01

    A new method of removing the high value feedback resistor in the charge sensitive preamplifier is introduced. The circuit analysis of this novel design is described and the measured performances of a practical circuit are provided

  20. High-Q Fabry–Pérot Micro-Cavities for High-Sensitivity Volume Refractometry

    Directory of Open Access Journals (Sweden)

    Noha Gaber

    2018-01-01

    Full Text Available This work reports a novel structure for a Fabry–Pérot micro cavity that combines the highest reported quality factor for an on-chip Fabry–Pérot resonator that exceeds 9800, and a very high sensitivity for an on-chip volume refractometer based on a Fabry–Pérot cavity that is about 1000 nm/refractive index unit (RIU. The structure consists of two cylindrical Bragg micromirrors that achieve confinement of the Gaussian beam in the plan parallel to the chip substrate, while for the perpendicular plan, external fiber rod lenses (FRLs are placed in the optical path of the input and the output of the cavity. This novel structure overcomes number of the drawbacks presented in previous designs. The analyte is passed between the mirrors, enabling its detection from the resonance peak wavelengths of the transmission spectra. Mixtures of ethanol and deionized (DI-water with different ratios are used as analytes with different refractive indices to exploit the device as a micro-opto-fluidic refractometer. The design criteria are detailed and the modeling is based on Gaussian-optics equations, which depicts a scenario closer to reality than the usually used ray-optics modeling.

  1. High-throughput, Highly Sensitive Analyses of Bacterial Morphogenesis Using Ultra Performance Liquid Chromatography*

    Science.gov (United States)

    Desmarais, Samantha M.; Tropini, Carolina; Miguel, Amanda; Cava, Felipe; Monds, Russell D.; de Pedro, Miguel A.; Huang, Kerwyn Casey

    2015-01-01

    The bacterial cell wall is a network of glycan strands cross-linked by short peptides (peptidoglycan); it is responsible for the mechanical integrity of the cell and shape determination. Liquid chromatography can be used to measure the abundance of the muropeptide subunits composing the cell wall. Characteristics such as the degree of cross-linking and average glycan strand length are known to vary across species. However, a systematic comparison among strains of a given species has yet to be undertaken, making it difficult to assess the origins of variability in peptidoglycan composition. We present a protocol for muropeptide analysis using ultra performance liquid chromatography (UPLC) and demonstrate that UPLC achieves resolution comparable with that of HPLC while requiring orders of magnitude less injection volume and a fraction of the elution time. We also developed a software platform to automate the identification and quantification of chromatographic peaks, which we demonstrate has improved accuracy relative to other software. This combined experimental and computational methodology revealed that peptidoglycan composition was approximately maintained across strains from three Gram-negative species despite taxonomical and morphological differences. Peptidoglycan composition and density were maintained after we systematically altered cell size in Escherichia coli using the antibiotic A22, indicating that cell shape is largely decoupled from the biochemistry of peptidoglycan synthesis. High-throughput, sensitive UPLC combined with our automated software for chromatographic analysis will accelerate the discovery of peptidoglycan composition and the molecular mechanisms of cell wall structure determination. PMID:26468288

  2. In situ high-resolution transmission electron microscopy synthesis observation of nanostructured carbon coated LiFePO 4

    Science.gov (United States)

    Trudeau, M. L.; Laul, D.; Veillette, R.; Serventi, A. M.; Mauger, A.; Julien, C. M.; Zaghib, K.

    In situ high-resolution transmission electron microscopy (HRTEM) studies of the structural transformations that occur during the synthesis of carbon-coated LiFePO 4 (C-LiFePO 4) and heat treatment to elevated temperatures were conducted in two different electron microscopes. Both microscopes have sample holders that are capable of heating up to 1500 °C, with one working under high vacuum and the other capable of operating with the sample surrounded by a low gaseous environment. The C-LiFePO 4 samples were prepared using three different compositions of precursor materials with Fe(0), Fe(II) or Fe(III), a Li-containing salt and a polyethylene- block-poly(ethylene glycol)-50% ethylene oxide or lactose. The in situ TEM studies suggest that low-cost Fe(0) and a low-cost carbon-containing compound such as lactose are very attractive precursors for mass production of C-LiFePO 4, and that 700 °C is the optimum synthesis temperature. At temperatures higher than 800 °C, LiFePO 4 has a tendency to decompose. The same in situ measurements have been made on particles without carbon coat. The results show that the homogeneous deposit of the carbon deposit at 700 °C is the result of the annealing that cures the disorder of the surface layer of bare LiFePO 4. Electrochemical tests supported the conclusion that the C-LiFePO 4 derived from Fe(0) is the most attractive for mass production.

  3. High definition in-situ electro-optical characterization for Roll to Roll printed electronics

    DEFF Research Database (Denmark)

    Pastorelli, Francesco

    2017-01-01

    Resume: Printed electronics is emerging as a new, large scale and cost effective technology that will be disruptive in fields such as energy harvesting, consumer electronics and medical sensors. The performance of printed organic electronic devices relies principally on the carrier mobility...... and molecular packing of the polymer semiconductor material. Unfortunately, the analysis of such materials is generally performed with destructive techniques, which are hard to make compatible with in situ measurements, and pose a great obstacle for the mass production of printed electronics devices. A rapid......-photon induced photoluminescence (TPPL) and second harmonic response. We anticipate that this non-linear optical method will substantially contribute to the understanding of printed electronic devices and demonstrate it as a promising novel tool for non-destructive and facile testing of materials during printing...

  4. In-situ short-circuit protection system and method for high-energy electrochemical cells

    Science.gov (United States)

    Gauthier, Michel; Domroese, Michael K.; Hoffman, Joseph A.; Lindeman, David D.; Noel, Joseph-Robert-Gaetan; Radewald, Vern E.; Rouillard, Jean; Rouillard, Roger; Shiota, Toshimi; Trice, Jennifer L.

    2003-04-15

    An in-situ thermal management system for an energy storage device. The energy storage device includes a plurality of energy storage cells each being coupled in parallel to common positive and negative connections. Each of the energy storage cells, in accordance with the cell's technology, dimensions, and thermal/electrical properties, is configured to have a ratio of energy content-to-contact surface area such that thermal energy produced by a short-circuit in a particular cell is conducted to a cell adjacent the particular cell so as to prevent the temperature of the particular cell from exceeding a breakdown temperature. In one embodiment, a fuse is coupled in series with each of a number of energy storage cells. The fuses are activated by a current spike capacitively produced by a cell upon occurrence of a short-circuit in the cell, thereby electrically isolating the short-circuited cell from the common positive and negative connections.

  5. In-situ short circuit protection system and method for high-energy electrochemical cells

    Science.gov (United States)

    Gauthier, Michel; Domroese, Michael K.; Hoffman, Joseph A.; Lindeman, David D.; Noel, Joseph-Robert-Gaetan; Radewald, Vern E.; Rouillard, Jean; Rouillard, Roger; Shiota, Toshimi; Trice, Jennifer L.

    2000-01-01

    An in-situ thermal management system for an energy storage device. The energy storage device includes a plurality of energy storage cells each being coupled in parallel to common positive and negative connections. Each of the energy storage cells, in accordance with the cell's technology, dimensions, and thermal/electrical properties, is configured to have a ratio of energy content-to-contact surface area such that thermal energy produced by a short-circuit in a particular cell is conducted to a cell adjacent the particular cell so as to prevent the temperature of the particular cell from exceeding a breakdown temperature. In one embodiment, a fuse is coupled in series with each of a number of energy storage cells. The fuses are activated by a current spike capacitively produced by a cell upon occurrence of a short-circuit in the cell, thereby electrically isolating the short-circuited cell from the common positive and negative connections.

  6. In-situ measurements of a highly fragmented comet: WIND STICS Measurements

    Science.gov (United States)

    Lepri, S. T.; Gilbert, J. A.; Gruesbeck, J. R.; Rubin, M.; Gershman, D. J.; Zurbuchen, T.

    2013-12-01

    In this paper, we present in-situ observations of cometary fragments associated with Comet 73P/Schwassmann-Wachmann as it passed very close to the Earth (<0.07AU) in 2006. We examine the spatial distribution of the fragments and the characteristics of the picked up ion velocity distributions. Comet 73P started to disintegrate in 1995, two major components B and C were recovered in 2001, and it burst into more than 36 pieces during its passage near the Earth in 2006. Distant fragmentation members, well-separated from the major identified fragments, passed between the Earth and Sun so that cometary pickup ions and possibly recombined solar wind minor ions convected past the WIND spacecraft in late May 2006. The Suprathermal Ion Composition Spectrometer on WIND provides a rare and detailed 3D glimpse of the newly picked up ion properties.

  7. Highly sensitive and selective detection of dopamine using one-pot synthesized highly photoluminescent silicon nanoparticles.

    Science.gov (United States)

    Zhang, Xiaodong; Chen, Xiaokai; Kai, Siqi; Wang, Hong-Yin; Yang, Jingjing; Wu, Fu-Gen; Chen, Zhan

    2015-03-17

    A simple and highly efficient method for dopamine (DA) detection using water-soluble silicon nanoparticles (SiNPs) was reported. The SiNPs with a high quantum yield of 23.6% were synthesized by using a one-pot microwave-assisted method. The fluorescence quenching capability of a variety of molecules on the synthesized SiNPs has been tested; only DA molecules were found to be able to quench the fluorescence of these SiNPs effectively. Therefore, such a quenching effect can be used to selectively detect DA. All other molecules tested have little interference with the dopamine detection, including ascorbic acid, which commonly exists in cells and can possibly affect the dopamine detection. The ratio of the fluorescence intensity difference between the quenched and unquenched cases versus the fluorescence intensity without quenching (ΔI/I) was observed to be linearly proportional to the DA analyte concentration in the range from 0.005 to 10.0 μM, with a detection limit of 0.3 nM (S/N = 3). To the best of our knowledge, this is the lowest limit for DA detection reported so far. The mechanism of fluorescence quenching is attributed to the energy transfer from the SiNPs to the oxidized dopamine molecules through Förster resonance energy transfer. The reported method of SiNP synthesis is very simple and cheap, making the above sensitive and selective DA detection approach using SiNPs practical for many applications.

  8. Selection of antigenic markers on a GFP-Cκ fusion scaffold with high sensitivity by eukaryotic ribosome display

    International Nuclear Information System (INIS)

    Yang Yongmin; Barankiewicz, Teresa J.; He Mingyue; Taussig, Michael J.; Chen, Swey-Shen

    2007-01-01

    Ribosome display is a cell-free system permitting gene selection through the physical association of genetic material (mRNA) and its phenotypic (protein) product. While often used to select single-chain antibodies from large libraries by panning against immobilized antigens, we have adapted ribosome display for use in the 'reverse' format in order to select high affinity antigenic determinants against solid-phase antibody. To create an antigenic scaffold, DNA encoding green fluorescent protein (GFP) was fused to a light chain constant domain (Cκ) with stop codon deleted, and with 5' signals (T7 promoter, Kozak) enabling coupled transcription/translation in a eukaryotic cell-free system. Epitopes on either GFP (5') or Cκ (3') were selected by anti-GFP or anti-Cκ antibodies, respectively, coupled to magnetic beads. After selection, mRNA was amplified directly from protein-ribosome-mRNA (PRM) complexes by in situ PCR followed by internal amplification and reassembly PCR. As little as 10 fg of the 1 kb DNA construct, i.e. approximately 7500 molecules, could be recovered following a single round of interaction with solid-phase anti-GFP antibody. This platform is highly specific and sensitive for the antigen-antibody interaction and may permit selection and reshaping of high affinity antigenic variants of scaffold proteins

  9. Selection of antigenic markers on a GFP-C{kappa} fusion scaffold with high sensitivity by eukaryotic ribosome display

    Energy Technology Data Exchange (ETDEWEB)

    Yongmin, Yang [Institute of Genetics, San Diego, CA 92121-2233 (United States); IgE Therapeutics, Inc., San Diego, CA 92121-2233 (United States); Barankiewicz, Teresa J [Institute of Genetics, San Diego, CA 92121-2233 (United States); IgE Therapeutics, Inc., San Diego, CA 92121-2233 (United States); Mingyue, He [Babraham Institute, Cambridge CB2 4AT (United Kingdom); Taussig, Michael J [Babraham Institute, Cambridge CB2 4AT (United Kingdom); Chen, Swey-Shen [Institute of Genetics, San Diego, CA 92121-2233 (United States) and IgE Therapeutics, Inc., San Diego, CA 92121-2233 (United States)

    2007-07-27

    Ribosome display is a cell-free system permitting gene selection through the physical association of genetic material (mRNA) and its phenotypic (protein) product. While often used to select single-chain antibodies from large libraries by panning against immobilized antigens, we have adapted ribosome display for use in the 'reverse' format in order to select high affinity antigenic determinants against solid-phase antibody. To create an antigenic scaffold, DNA encoding green fluorescent protein (GFP) was fused to a light chain constant domain (C{kappa}) with stop codon deleted, and with 5' signals (T7 promoter, Kozak) enabling coupled transcription/translation in a eukaryotic cell-free system. Epitopes on either GFP (5') or C{kappa} (3') were selected by anti-GFP or anti-C{kappa} antibodies, respectively, coupled to magnetic beads. After selection, mRNA was amplified directly from protein-ribosome-mRNA (PRM) complexes by in situ PCR followed by internal amplification and reassembly PCR. As little as 10 fg of the 1 kb DNA construct, i.e. approximately 7500 molecules, could be recovered following a single round of interaction with solid-phase anti-GFP antibody. This platform is highly specific and sensitive for the antigen-antibody interaction and may permit selection and reshaping of high affinity antigenic variants of scaffold proteins.

  10. A silicon-based electrochemical sensor for highly sensitive, specific, label-free and real-time DNA detection

    International Nuclear Information System (INIS)

    Guo, Yuanyuan; Su, Shao; Wei, Xinpan; Zhong, Yiling; Su, Yuanyuan; He, Yao; Huang, Qing; Fan, Chunhai

    2013-01-01

    We herein present a new kind of silicon-based electrochemical sensor using a gold nanoparticles-decorated silicon wafer (AuNPs@Si) as a high-performance electrode, which is facilely prepared via in situ AuNPs growth on a silicon wafer. Particularly significantly, the resultant electrochemical sensor is efficacious for label-free DNA detection with high sensitivity due to the unique merits of the prepared silicon-based electrode. Typically, DNA at remarkably low concentrations (1–10 fM) could be readily detected without requiring additional signal-amplification procedures, which is better than or comparable to the lowest DNA concentration ever detected via well-studied signal-amplification-assisted electrochemical sensors. Moreover, the silicon-based sensor features high specificity, allowing unambiguous discrimination of single-based mismatches. We further show that real-time DNA assembly is readily monitored via recording the intensity changes of current signals due to the robust thermal stability of the silicon-based electrode. The unprecedented advantages of the silicon-based electrochemical sensor would offer new opportunities for myriad sensing applications. (paper)

  11. Depleted Nanocrystal-Oxide Heterojunctions for High-Sensitivity Infrared Detection

    Science.gov (United States)

    2015-08-28

    Approved for Public Release; Distribution Unlimited Final Report: 4.3 Electronic Sensing - Depleted Nanocrystal- Oxide Heterojunctions for High...reviewed journals: Final Report: 4.3 Electronic Sensing - Depleted Nanocrystal- Oxide Heterojunctions for High-Sensitivity Infrared Detection Report Title...PERCENT_SUPPORTEDNAME FTE Equivalent: Total Number: 1 1 Final Progress Report Project title: Depleted Nanocrystal- Oxide Heterojunctions for High

  12. A rotational and axial motion system load frame insert for in situ high energy x-ray studies

    Energy Technology Data Exchange (ETDEWEB)

    Shade, Paul A., E-mail: paul.shade.1@us.af.mil; Schuren, Jay C.; Turner, Todd J. [Materials and Manufacturing Directorate, Air Force Research Laboratory, Wright-Patterson AFB, Ohio 45433 (United States); Blank, Basil [PulseRay, Beaver Dams, New York 14812 (United States); Kenesei, Peter; Goetze, Kurt; Lienert, Ulrich; Almer, Jonathan [Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Suter, Robert M. [Carnegie Mellon University, Pittsburgh, Pennsylvania 15213 (United States); Bernier, Joel V.; Li, Shiu Fai [Engineering Directorate, Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Lind, Jonathan [Carnegie Mellon University, Pittsburgh, Pennsylvania 15213 (United States); Engineering Directorate, Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)

    2015-09-15

    High energy x-ray characterization methods hold great potential for gaining insight into the behavior of materials and providing comparison datasets for the validation and development of mesoscale modeling tools. A suite of techniques have been developed by the x-ray community for characterizing the 3D structure and micromechanical state of polycrystalline materials; however, combining these techniques with in situ mechanical testing under well characterized and controlled boundary conditions has been challenging due to experimental design requirements, which demand new high-precision hardware as well as access to high-energy x-ray beamlines. We describe the design and performance of a load frame insert with a rotational and axial motion system that has been developed to meet these requirements. An example dataset from a deforming titanium alloy demonstrates the new capability.

  13. Monitoring of high temperature zone by resistivity tomography during in-situ heater test in sedimentary soft rocks

    International Nuclear Information System (INIS)

    Kubota, Kenji; Suzuki, Koichi; Ikenoya, Takafumi; Takakura, Nozomu; Tani, Kazuo

    2008-01-01

    In-situ heater test has been conducted to evaluate the influence of high temperature in an underground facility at a depth of 50 m. Resistivity monitoring is thought to be effective to map the extent of the high temperature zone. So we have conducted resistivity tomography during the heater test. As a result, low resistivity zone was appeared near the heated area as starting the heating, and the zone was expanded. Resistivity of rock is proportional to resistivity of pore water. It is known that pore water resistivity decreases as the temperature rise. This suggests that high temperature zone is detected and spatial distribution of temperature can be mapped by resistivity tomography. (author)

  14. ISDoT: in situ decellularization of tissues for high-resolution imaging and proteomic analysis of native extracellular matrix

    DEFF Research Database (Denmark)

    Mayorca-Guiliani, Alejandro E.; Madsen, Chris D.; Cox, Thomas R.

    2017-01-01

    The extracellular matrix (ECM) is a master regulator of cellular phenotype and behavior. It has a crucial role in both normal tissue homeostasis and disease pathology. Here we present a fast and efficient approach to enhance the study of ECM composition and structure. Termed in situ...... decellularization of tissues (ISDoT), it allows whole organs to be decellularized, leaving native ECM architecture intact. These three-dimensional decellularized tissues can be studied using high-resolution fluorescence and second harmonic imaging, and can be used for quantitative proteomic interrogation of the ECM....... Our method is superior to other methods tested in its ability to preserve the structural integrity of the ECM, facilitate high-resolution imaging and quantitatively detect ECM proteins. In particular, we performed high-resolution sub-micron imaging of matrix topography in normal tissue and over...

  15. In situ corrosion studies on selected high level waste packaging materials under simulated disposal conditions in rock salt

    International Nuclear Information System (INIS)

    Smailos, E.; Schwarzkopf, W.; Koester, R.

    1988-01-01

    In order to qualify corrosion resistant materials for high level waste (HLW) packagings acting as a long-term barrier in a rock salt repository, the corrosion behavior of preselected materials is being investigated in laboratory-scale and in-situ experiments. This work reports about in-situ corrosion experiments on unalloyed steels, Ti 99.8-Pd, Hastelloy C4, and iron-base alloys, as nodular cast iron, Ni-Resist D4 and Si-cast iron, under simulated disposal conditions. The results of the investigations can be summarized as follows: (1) all materials investigated exhibited high resistance to corrosion under the conditions prevailing in the Brine Migration Test; (2) all materials and above all the materials with passivating oxide layers such as Ti 99.8-Pd and Hastelloy C4 which may corrode selectively already in the presence of minor amounts of brine had been resistant with respect to any type of local corrosion attack; the gamma-radiation of 3 · 10 2 Gy/h did not exert an influence on the corrosion behavior of the materials

  16. Multi-sensor system for in situ shape monitoring and damage identification of high-speed composite rotors

    Science.gov (United States)

    Philipp, K.; Filippatos, A.; Kuschmierz, R.; Langkamp, A.; Gude, M.; Fischer, A.; Czarske, J.

    2016-08-01

    Glass fibre-reinforced polymer (GFRP) composites offer a higher stiffness-to-weight ratio than conventional rotor materials used in turbomachinery. However, the material behaviour of GFRP high-speed rotors is difficult to predict due to the complexity of the composite material and the dynamic loading conditions. Consequently dynamic expansion measurements of GRFP rotors are required in situ and with micron precision. However, the whirling motion amplitude is about two orders of magnitude higher than the desired precision. To overcome this problem, a multi-sensor system capable of separating rotor expansion and whirling motion is proposed. High measurement rates well above the rotational frequency and micron uncertainty are achieved at whirling amplitudes up to 120μm and surface velocities up to 300 m/s. The dynamic elliptical expansion of a GFRP rotor is investigated in a rotor loading test rig under vacuum conditions. In situ measurements identified not only the introduced damage but also damage initiation and propagation.

  17. Development of in situ Brillouin spectroscopy at high pressure and high temperature with synchrotron radiation and infrared laser heating system: Application to the Earth's deep interior

    Science.gov (United States)

    Murakami, Motohiko; Asahara, Yuki; Ohishi, Yasuo; Hirao, Naohisa; Hirose, Kei

    2009-05-01

    Seismic wave velocity profiles in the Earth provide one of the strongest constraints on structure, mineralogy and elastic properties of the Earth's deep interior. Accurate sound velocity data of deep Earth materials under relevant high-pressure and high-temperature conditions, therefore, are essential for interpretation of seismic data. Such information can be directly obtained from Brillouin scattering measurement. Here we describe an in situ Brillouin scattering system for measurements at high pressure and high temperature using a laser heated diamond anvil cell and synchrotron radiation for sample characterization. The system has been used with single-crystal and polycrystalline materials, and with glass and fluid phase. It provided high quality sound velocity and elastic data with X-ray diffraction data at high pressure and/or high temperature. Those combined techniques can potentially offer the essential information for resolving many remaining issues in mineral physics.

  18. Monte carlo calculation of energy-dependent response of high-sensitive neutron monitor, HISENS

    International Nuclear Information System (INIS)

    Imanaka, Tetsuji; Ebisawa, Tohru; Kobayashi, Keiji; Koide, Hiroaki; Seo, Takeshi; Kawano, Shinji

    1988-01-01

    A highly sensitive neutron monitor system, HISENS, has been developed to measure leakage neutrons from nuclear facilities. The counter system of HISENS contains a detector bank which consists of ten cylindrical proportional counters filled with 10 atm 3 He gas and a paraffin moderator mounted in an aluminum case. The size of the detector bank is 56 cm high, 66 cm wide and 10 cm thick. It is revealed by a calibration experiment using an 241 Am-Be neutron source that the sensitivity of HISENS is about 2000 times as large as that of a typical commercial rem-counter. Since HISENS is designed to have a high sensitivity in a wide range of neutron energy, the shape of its energy dependent response curve cannot be matched to that of the dose equivalent conversion factor. To estimate dose equivalent values from neutron counts by HISENS, it is necessary to know the energy and angular characteristics of both HISENS and the neutron field. The area of one side of the detector bank is 3700 cm 2 and the detection efficiency in the constant region of the response curve is about 30 %. Thus, the sensitivity of HISENS for this energy range is 740 cps/(n/cm 2 /sec). This value indicates the extremely high sensitivity of HISENS as compared with exsisting highly sensitive neutron monitors. (Nogami, K.)

  19. Structural characterizaiton and gas reactions of small metal particles by high-resolution, in-situ TEM and TED

    Science.gov (United States)

    1984-01-01

    The existing in-situ transmission electron microscopy (TEM) facility was improved by adding a separately pumped mini-specimen chamber. The chamber contains wire-evaporation sources for three metals and a specimen heater for moderate substrate temperatures. A sample introduction device was constructed, installed, and tested, facilitating rapid introduction of a specimen into the mini-chamber while maintaining the background pressure in that chamber in the 10(-9) millibar range. Small particles and clusters of Pd, grown by deposition from the vapor phase in an in-situ TEM facility on amorphous and crystalline support films of alumina and on ultra-thin carbon films, were analyzed by conventional high-resolution TEM and image analysis in terms of detectability, number density, and size distribution. The smallest particles that could be detected and counted contained no more than 6 atoms; size determinations could be made for particles 1 nm in diameter. The influence of various oxygen plasma treatments, annealing treatments, and of increasing the substrate temperature during deposition was investigated. The TEM technique was employed to demonstrate that under otherwise identica l conditions the lattice parameter of Pd particles in the 1 to 2 nm size range and supported in random orientation on ex-situ prepared mica films is expanded by some 3% when compared to 5 nm size particles. It is believed that this expansion is neither a small-particle diffraction effect nor due to pseudomorphism, but that it is due to a annealing-induced transformation of the small as-deposited particles with predominantly composite crystal structures into larger particles with true f.c.c. structure and thus inherently smaller lattice parameter.

  20. A novel detection platform for parallel monitoring of DNA hybridization with high sensitivity and specificity

    DEFF Research Database (Denmark)

    Yi, Sun; Perch-Nielsen, Ivan R.; Wang, Zhenyu

    We developed a high-sensitive platform to monior multiple hybridization events in real time. By creating a microoptical array in a polymeric chip, the system combine the excellent discriminative power of supercritical angle fluorescence (SAF) microscopy with high-throughput capabilities of microa......We developed a high-sensitive platform to monior multiple hybridization events in real time. By creating a microoptical array in a polymeric chip, the system combine the excellent discriminative power of supercritical angle fluorescence (SAF) microscopy with high-throughput capabilities...

  1. Intratumoral Delivery of Doxorubicin on Folate-Conjugated Graphene Oxide by In-Situ Forming Thermo-Sensitive Hydrogel for Breast Cancer Therapy

    Directory of Open Access Journals (Sweden)

    Yi Teng Fong

    2017-11-01

    Full Text Available By taking advantage of the pH-sensitive drug release property of graphene oxide (GO after intracellular uptake, we prepared folic acid (FA-conjugated GO (GOFA for targeted delivery of the chemotherapeutic drug doxorubicin (DOX. GOFA-DOX was further encapsulated in an injectable in-situ forming thermo-sensitive hyaluronic acid-chitosan-g-poly(N-isopropylacrylamide (HACPN hydrogel for intratumoral delivery of DOX. As the degradation time of HACPN could be extended up to 3 weeks, intratumoral delivery of GOFA-DOX/HACPN could provide controlled and targeted delivery of DOX through slow degradation HACPN and subsequent cellular uptake of released GOFA-DOX by tumor cells through interactions of GOFA with folate receptors on the tumor cell’s surface. GOFA nano-carrier and HACPN hydrogel were first characterized for the physico-chemical properties. The drug loading experiments indicated the best preparation condition of GOFA-DOX was by reacting 0.1 mg GOFA with 2 mg DOX. GOFA-DOX showed pH-responsive drug release with ~5 times more DOX released at pH 5.5 than at pH 7.4 while only limited DOX was released from GOFA-DOX/HACPN at pH 7.4. Intracellular uptake of GOFA by endocytosis and release of DOX from GOFA-DOX in vitro could be confirmed from transmission electron microscopic and confocal laser scanning microscopic analysis with MCF-7 breast cancer cells. The targeting effect of FA was revealed when intracellular uptake of GOFA was blocked by excess FA. This resulted in enhanced in vitro cytotoxicity as revealed from the lower half maximal inhibitory concentration (IC50 value of GOFA-DOX (7.3 μg/mL compared with that of DOX (32.5 μg/mL and GO-DOX (10 μg/mL. The flow cytometry analysis indicated higher apoptosis rates for cells treated with GOFA-DOX (30% compared with DOX (8% and GO-DOX (11%. Animal studies were carried out with subcutaneously implanted MCF-7 cells in BALB/c nude mice and subject to intratumoral administration of drugs. The relative

  2. In situ beam angle measurement in a multi-wafer high current ion implanter

    International Nuclear Information System (INIS)

    Freer, B.S.; Reece, R.N.; Graf, M.A.; Parrill, T.; Polner, D.

    2005-01-01

    Direct, in situ measurement of the average angle and angular content of an ion beam in a multi-wafer ion implanter is reported for the first time. A new type of structure and method are described. The structures are located on the spinning disk, allowing precise angular alignment to the wafers. Current that passes through the structures is known to be within a range of angles and is detected behind the disk. By varying the angle of the disk around two axes, beam current versus angle is mapped and the average angle and angular spread are calculated. The average angle measured in this way is found to be consistent with that obtained by other techniques, including beam centroid offset and wafer channeling methods. Average angle of low energy beams, for which it is difficult to use other direct methods, is explored. A 'pencil beam' system is shown to give average angle repeatability of 0.13 deg. (1σ) or less, for two low energy beams under normal tuning variations, even though no effort was made to control the angle

  3. In-situ continuous scanning high efficiency particulate air (HEPA) filter monitoring system

    International Nuclear Information System (INIS)

    Kirchner, K.N.; Johnson, C.M.; Lucerna, J.J.; Barnett, R.L.

    1985-01-01

    The testing and replacement of HEPA filters, which are widely used in the nuclear industry to purify process air before it is ventilated to the atmosphere, is a costly and labor-intensive undertaking. Current methods of testing filter performance, such as differential pressure measurement and scanning air monitoring, allow for determination of overall filter performance but preclude detection of symptoms of incipient filter failure, such as small holes in the filters themselves. Using current technology, a continual in-situ monitoring system has been designed which provides three major improvements over current methods of filter testing and replacement. This system (1) realizes a cost savings by reducing the number of intact filters which are currently being replaced unnecessarily, (2) provides a more accurate and quantitative measurement of filter performance than is currently achieved with existing testing methods, and (3) reduces personnel exposure to a radioactive environment by automatically performing most testing operations. The operation and performance of the HEPA filter monitoring system are discussed

  4. Transformation Heat Treatment of Rapidly Quenched Nb3A1 Precursor Monitored in situ by High Energy Synchrotron Diffraction

    CERN Document Server

    Scheuerlein, C; Di Michiel, M; Jin, X; Takeuchi, T; Kikuchi, A; Tsuchiya, K; Nakagawa, K; Nakamoto, T

    2013-01-01

    Nb3Al superconductors are studied for use in high field magnets. Fine grained Nb3Al with nearly stoichiometric Al content is obtained by a Rapid Heating Quenching and Transformation (RHQT) process. We describe a non destructive in situ study of the transformation process step of a RHQ Nb3Al precursor wire with ramp rates of either 120 °C/h or 800 °C/h. High energy synchrotron x-ray diffraction measurements show the transformation from a Nb(Al)SS supersaturated solid solution into Nb3Al. When heating with a ramp rate of 120 °C/h a strong reduction of the Nb(Al)SS (110) diffraction peak component is observed when the temperature exceeds 660 °C. Additional diffraction peaks are detectable in the approximate temperature interval 610 °C - 750 °C and significant Nb3Al growth is observed above 730 °C.

  5. Intra-arterial papaverine and leg vascular resistance during in situ bypass surgery with high or low epidural anaesthesia

    DEFF Research Database (Denmark)

    Rørdam, Peter; Jensen, Leif Panduro; Schroeder, T V

    1993-01-01

    In situ saphenous vein arterial bypass flow was studied in 16 patients with respect to level of epidural anaesthesia. Arterial pressure and electromagnetic flow were used to evaluate arterial tone by intra-arterial (i.a.) papaverine. Eight patients had a low epidural block (... patients were operated during high epidural anaesthesia (> Th. 10). Flow increased and arterial pressure decreased after i.a. papaverine in all patients. When compared with patients operated during high epidural anaesthesia, flow increase and decrease in vascular resistance took place in patients operated...... during low epidural anaesthesia (P i.a. papaverine was not significantly different in patients operated in low epidural and general anaesthesia (n = 8). In eight patients with insulin-dependent diabetes mellitus who had low epidural anaesthesia, the increase...

  6. Thermal stability and in situ SiN passivation of InAlN/GaN high electron mobility heterostructures

    Energy Technology Data Exchange (ETDEWEB)

    Lugani, L.; Carlin, J.-F.; Py, M. A.; Grandjean, N. [ICMP, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne (Switzerland)

    2014-09-15

    We investigate the thermal stability of nearly lattice-matched InAlN layers under metal organic vapor phase epitaxy conditions for temperatures >800 °C and show that they are not fully stable. In particular, InAlN top layers undergo degradation during high temperature annealing due to a surface related process, which causes the loss of crystal quality. This strongly impacts the transport properties of InAlN/GaN HEMT heterostructures; in particular, the mobility is significantly reduced. However, we demonstrate that high thermal stability can be achieved by capping with a GaN layer as thin as 0.5 nm. Those findings enabled us to realize in situ passivated HEMT heterostructures with state of the art transport properties.

  7. DOTS: A High Resolution Orbitrap Mass Spectrometer for In Situ Analysis of the surface samples of Airless Planetary Bodies

    Science.gov (United States)

    Briois, Christelle; Thissen, Roland; Engrand, Cécile; Altwegg, Kathrin; Bouabdellah, Abdel; Boukrara, Amirouche; Carrasco, Nathalie; Chapuis, Claude; Cottin, Hervé; Grün, Eberhard; Grand, Noel; Henkel, Hartmut; Kempf, Sascha; Lebreton, Jean-Pierre; Makarov, Alexander A.; Postber, Frank; Srama, Ralf; Schmidt, Jürgen; Szopa, Cyril; Thirkell, Laurent; Tobie, Gabriel; Wurz, Peter; Zolotov, Mikhail Yu

    2013-04-01

    The dust detectors on board the Ulysses and Galileo spacecraft have shown that the Galilean satellites are surrounded by clouds of sub-micrometer size grains generated by impacts of interplanetary (micro-) meteoroids [1, 2]. In situ chemical analysis from orbit of these ballistic grains ejected from the surface of airless bodies provides a unique opportunity to remotely access the chemical composition of the Jovian moons' surface and subsurface. For Saturn, in situ identification by the Cassini Dust Analyzer (CDA) of sodium in icy grains in the E-Ring and in Enceladus plumes have proven a subsurface liquid water reservoir inside Enceladus [3, 4]. Noticeably, this was not accessible to other in situ or traditional remote sensing techniques. In situ measurements, either during a flyby or from orbit, of grains ejected from the surface, or emerging from the subsurface, of an airless body is a powerful tool to remotely study its surface composition and the nature of its geological activity. Crucial constraints on habitability can thus be determined. Our consortium of laboratories, in collaboration with Thermo Fischer Scientific [5, 6], is currently developing a high mass resolution Fourier Transform (FT) Orbitrap-based mass spectrometer optimized for in situ analysis of dust and icy grains in the environment of Solar System airless bodies. This new generation of dust mass spectrometer was studied in the framework of the Europa Jupiter System Mission (EJSM) instrument study in 2010-2012 and proposed in response to ESA's AO for the JUpiter ICy moons Explorer (JUICE) mission [7]. This mass analyser can provide very high mass resolution analysis (M/ΔM reaching 50 000 at m/z 50 Da). DOTS would allow identification of elemental and molecular species with excellent accuracy, in the 20-1000 Da mass range. In the context of the JUICE mission, DOTS would provide decisive information on the surface composition and on the putative liquid oceans in the subsurface of Ganymede

  8. ZnO nanorod biosensor for highly sensitive detection of specific protein binding

    International Nuclear Information System (INIS)

    Kim, Jin Suk; Park, Won Il; Lee, Chul Ho; Yi, Gyu Chul

    2006-01-01

    We report on the fabrication of electrical biosensors based on functionalized ZnO nanorod surfaces with biotin for highly sensitive detection of biological molecules. Due to the clean interface and easy surface modification, the ZnO nanorod sensors can easily detect streptavidin binding down to a concentration of 25 nM, which is more sensitive than previously reported one-dimensional (1D) nanostructure electrical biosensors. In addition, the unique device structure with a micrometer-scale hole at the center of the ZnO nanorod's conducting channel reduces the leakage current from the aqueous solution, hence enhancing device sensitivity. Moreover, ZnO nanorod field-effect-transistor (FET) sensors may open up opportunities to create many other oxide nanorod electrical sensors for highly sensitive and selective real-time detection of a wide variety of biomolecules.

  9. In Situ Local Measurement of Austenite Mechanical Stability and Transformation Behavior in Third-Generation Advanced High-Strength Steels

    Science.gov (United States)

    Abu-Farha, Fadi; Hu, Xiaohua; Sun, Xin; Ren, Yang; Hector, Louis G.; Thomas, Grant; Brown, Tyson W.

    2018-05-01

    Austenite mechanical stability, i.e., retained austenite volume fraction (RAVF) variation with strain, and transformation behavior were investigated for two third-generation advanced high-strength steels (3GAHSS) under quasi-static uniaxial tension: a 1200 grade, two-phase medium Mn (10 wt pct) TRIP steel, and a 980 grade, three-phase TRIP steel produced with a quenching and partitioning heat treatment. The medium Mn (10 wt pct) TRIP steel deforms inhomogeneously via propagative instabilities (Lüders and Portevin Le Châtelier-like bands), while the 980 grade TRIP steel deforms homogenously up to necking. The dramatically different deformation behaviors of these steels required the development of a new in situ experimental technique that couples volumetric synchrotron X-ray diffraction measurement of RAVF with surface strain measurement using stereo digital image correlation over the beam impingement area. Measurement results with the new technique are compared to those from a more conventional approach wherein strains are measured over the entire gage region, while RAVF measurement is the same as that in the new technique. A determination is made as to the appropriateness of the different measurement techniques in measuring the transformation behaviors for steels with homogeneous and inhomogeneous deformation behaviors. Extension of the new in situ technique to the measurement of austenite transformation under different deformation modes and to higher strain rates is discussed.

  10. In situ analysis and structural elucidation of sainfoin (Onobrychis viciifolia) tannins for high-throughput germplasm screening.

    Science.gov (United States)

    Gea, An; Stringano, Elisabetta; Brown, Ron H; Mueller-Harvey, Irene

    2011-01-26

    A rapid thiolytic degradation and cleanup procedure was developed for analyzing tannins directly in chlorophyll-containing sainfoin ( Onobrychis viciifolia ) plants. The technique proved suitable for complex tannin mixtures containing catechin, epicatechin, gallocatechin, and epigallocatechin flavan-3-ol units. The reaction time was standardized at 60 min to minimize the loss of structural information as a result of epimerization and degradation of terminal flavan-3-ol units. The results were evaluated by separate analysis of extractable and unextractable tannins, which accounted for 63.6-113.7% of the in situ plant tannins. It is of note that 70% aqueous acetone extracted tannins with a lower mean degree of polymerization (mDP) than was found for tannins analyzed in situ. Extractable tannins had between 4 and 29 lower mDP values. The method was validated by comparing results from individual and mixed sample sets. The tannin composition of different sainfoin accessions covered a range of mDP values from 16 to 83, procyanidin/prodelphinidin (PC/PD) ratios from 19.2/80.8 to 45.6/54.4, and cis/trans ratios from 74.1/25.9 to 88.0/12.0. This is the first high-throughput screening method that is suitable for analyzing condensed tannin contents and structural composition directly in green plant tissue.

  11. In Situ Biodiesel Production from Fast-Growing and High Oil Content Chlorella pyrenoidosa in Rice Straw Hydrolysate

    Science.gov (United States)

    Li, Penglin; Miao, Xiaoling; Li, Rongxiu; Zhong, Jianjiang

    2011-01-01

    Rice straw hydrolysate was used as lignocellulose-based carbon source for Chlorella pyrenoidosa cultivation and the feasibility of in situ biodiesel production was investigated. 13.7 g/L sugar was obtained by enzymatic hydrolyzation of rice straw. Chlorella pyrenoidosa showed a rapid growth in the rice straw hydrolysate medium, the maximum biomass concentration of 2.83 g/L was obtained in only 48 hours. The lipid content of the cells reached as high as 56.3%. In situ transesterification was performed for biodiesel production. The optimized condition was 1 g algal powder, 6 mL n-hexane, and 4 mL methanol with 0.5 M sulfuric acid at the temperature of 90°C in 2-hour reaction time, under which over 99% methyl ester content and about 95% biodiesel yield were obtained. The results suggested that the method has great potential in the production of biofuels with lignocellulose as an alternative carbon source for microalgae cultivation. PMID:21318171

  12. Laser-induced incandescence (LII) diagnostic for in situ monitoring of nanoparticle synthesis in a high-pressure arc discharge

    Science.gov (United States)

    Yatom, Shurik; Vekselman, Vladislav; Mitrani, James; Stratton, Brentley; Raitses, Yevgeny; LaboratoryPlasma Nanosynthesis Team

    2016-10-01

    A DC arc discharge is commonly used for synthesis of carbon nanoparticles, including buckyballs, carbon nanotubes, and graphene flakes. In this work we show the first results of nanoparticles monitored during the arc discharge. The graphite electrode is vaporized by high current (60 A) in a buffer Helium gas leading to nanoparticle synthesis in a low temperature plasma. The arc was shown to oscillate, which can possibly influence the nano-synthesis. To visualize the nanoparticles in-situ we employ the LII technique. The nanoparticles with radii >50 nm, emerging from the arc area are heated with a short laser pulse and incandesce. The resulting radiation is captured with an ICCD camera, showing the location of the generated nanoparticles. The images of incandescence are studied together with temporally synchronized fast-framing imaging of C2 emission, to connect the dynamics of arc instabilities, C2 molecules concentration and nanoparticles. The time-resolved incandescence signal is analyzed with combination of ex-situ measurements of the synthesized nanoparticles and LII modeling, to provide the size distribution of produced nanoparticles. This work was supported by US Department of Energy, Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division.

  13. Highly Sensitive, Transparent, and Durable Pressure Sensors Based on Sea-Urchin Shaped Metal Nanoparticles.

    Science.gov (United States)

    Lee, Donghwa; Lee, Hyungjin; Jeong, Youngjun; Ahn, Yumi; Nam, Geonik; Lee, Youngu

    2016-11-01

    Highly sensitive, transparent, and durable pressure sensors are fabricated using sea-urchin-shaped metal nanoparticles and insulating polyurethane elastomer. The pressure sensors exhibit outstanding sensitivity (2.46 kPa -1 ), superior optical transmittance (84.8% at 550 nm), fast response/relaxation time (30 ms), and excellent operational durability. In addition, the pressure sensors successfully detect minute movements of human muscles. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. A high sensitivity process variation sensor utilizing sub-threshold operation

    OpenAIRE

    Meterelliyoz, Mesut; Song, Peilin; Stellari, Franco; Kulkarni, Jaydeep P.; Roy, Kaushik

    2008-01-01

    In this paper, we propose a novel low-power, bias-free, high-sensitivity process variation sensor for monitoring random variations in the threshold voltage. The proposed sensor design utilizes the exponential current-voltage relationship of sub-threshold operation thereby improving the sensitivity by 2.3X compared to the above-threshold operation. A test-chip containing 128 PMOS and 128 NMOS devices has been fabri...

  15. A Microneedle Functionalized with Polyethyleneimine and Nanotubes for Highly Sensitive, Label-Free Quantification of DNA

    OpenAIRE

    Saadat-Moghaddam, Darius; Kim, Jong-Hoon

    2017-01-01

    The accurate measure of DNA concentration is necessary for many DNA-based biological applications. However, the current methods are limited in terms of sensitivity, reproducibility, human error, and contamination. Here, we present a microneedle functionalized with polyethyleneimine (PEI) and single-walled carbon nanotubes (SWCNTs) for the highly sensitive quantification of DNA. The microneedle was fabricated using ultraviolet (UV) lithography and anisotropic etching, and then functionalized w...

  16. High sensitivity phase retrieval method in grating-based x-ray phase contrast imaging

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Zhao; Gao, Kun; Chen, Jian; Wang, Dajiang; Wang, Shenghao; Chen, Heng; Bao, Yuan; Shao, Qigang; Wang, Zhili, E-mail: wangnsrl@ustc.edu.cn [National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230029 (China); Zhang, Kai [Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); Zhu, Peiping; Wu, Ziyu, E-mail: wuzy@ustc.edu.cn [National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230029, China and Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China)

    2015-02-15

    Purpose: Grating-based x-ray phase contrast imaging is considered as one of the most promising techniques for future medical imaging. Many different methods have been developed to retrieve phase signal, among which the phase stepping (PS) method is widely used. However, further practical implementations are hindered, due to its complex scanning mode and high radiation dose. In contrast, the reverse projection (RP) method is a novel fast and low dose extraction approach. In this contribution, the authors present a quantitative analysis of the noise properties of the refraction signals retrieved by the two methods and compare their sensitivities. Methods: Using the error propagation formula, the authors analyze theoretically the signal-to-noise ratios (SNRs) of the refraction images retrieved by the two methods. Then, the sensitivities of the two extraction methods are compared under an identical exposure dose. Numerical experiments are performed to validate the theoretical results and provide some quantitative insight. Results: The SNRs of the two methods are both dependent on the system parameters, but in different ways. Comparison between their sensitivities reveals that for the refraction signal, the RP method possesses a higher sensitivity, especially in the case of high visibility and/or at the edge of the object. Conclusions: Compared with the PS method, the RP method has a superior sensitivity and provides refraction images with a higher SNR. Therefore, one can obtain highly sensitive refraction images in grating-based phase contrast imaging. This is very important for future preclinical and clinical implementations.

  17. High sensitivity phase retrieval method in grating-based x-ray phase contrast imaging

    International Nuclear Information System (INIS)

    Wu, Zhao; Gao, Kun; Chen, Jian; Wang, Dajiang; Wang, Shenghao; Chen, Heng; Bao, Yuan; Shao, Qigang; Wang, Zhili; Zhang, Kai; Zhu, Peiping; Wu, Ziyu

    2015-01-01

    Purpose: Grating-based x-ray phase contrast imaging is considered as one of the most promising techniques for future medical imaging. Many different methods have been developed to retrieve phase signal, among which the phase stepping (PS) method is widely used. However, further practical implementations are hindered, due to its complex scanning mode and high radiation dose. In contrast, the reverse projection (RP) method is a novel fast and low dose extraction approach. In this contribution, the authors present a quantitative analysis of the noise properties of the refraction signals retrieved by the two methods and compare their sensitivities. Methods: Using the error propagation formula, the authors analyze theoretically the signal-to-noise ratios (SNRs) of the refraction images retrieved by the two methods. Then, the sensitivities of the two extraction methods are compared under an identical exposure dose. Numerical experiments are performed to validate the theoretical results and provide some quantitative insight. Results: The SNRs of the two methods are both dependent on the system parameters, but in different ways. Comparison between their sensitivities reveals that for the refraction signal, the RP method possesses a higher sensitivity, especially in the case of high visibility and/or at the edge of the object. Conclusions: Compared with the PS method, the RP method has a superior sensitivity and provides refraction images with a higher SNR. Therefore, one can obtain highly sensitive refraction images in grating-based phase contrast imaging. This is very important for future preclinical and clinical implementations

  18. Development of a high sensitivity pinhole type gamma camera using semiconductors for low dose rate fields

    Science.gov (United States)

    Ueno, Yuichiro; Takahashi, Isao; Ishitsu, Takafumi; Tadokoro, Takahiro; Okada, Koichi; Nagumo, Yasushi; Fujishima, Yasutake; Yoshida, Akira; Umegaki, Kikuo

    2018-06-01

    We developed a pinhole type gamma camera, using a compact detector module of a pixelated CdTe semiconductor, which has suitable sensitivity and quantitative accuracy for low dose rate fields. In order to improve the sensitivity of the pinhole type semiconductor gamma camera, we adopted three methods: a signal processing method to set the discriminating level lower, a high sensitivity pinhole collimator and a smoothing image filter that improves the efficiency of the source identification. We tested basic performances of the developed gamma camera and carefully examined effects of the three methods. From the sensitivity test, we found that the effective sensitivity was about 21 times higher than that of the gamma camera for high dose rate fields which we had previously developed. We confirmed that the gamma camera had sufficient sensitivity and high quantitative accuracy; for example, a weak hot spot (0.9 μSv/h) around a tree root could be detected within 45 min in a low dose rate field test, and errors of measured dose rates with point sources were less than 7% in a dose rate accuracy test.

  19. Investigating Forest Harvest Effects on DOC Concentration and Quality: An In Situ, High Resolution Approach to Quantifying DOC Export Dynamics

    Science.gov (United States)

    Jollymore, A. J.; Johnson, M. S.; Hawthorne, I.

    2013-12-01

    Justification: Forest harvest effects on water quality can signal alterations in hydrologic and ecologic processes incurred as a result of forest harvest activities. Organic matter (OM), specifically dissolved organic carbon (DOC), plays a number of important roles mediating UV-light penetration, redox reactivity and microbial activity within aquatic ecosystems. Quantification of DOC is typically pursued via grab sampling followed by chemical or spectrophotometric analysis, limiting the temporal resolution obtained as well as the accuracy of export calculations. The advent of field-deployable sensors capable of measuring DOC concentration and certain quality characteristics in situ provides the ability to observe dynamics at temporal scales necessary for accurate calculation of DOC flux, as well as the observation of dynamic changes in DOC quality on timescales impossible to observe through grab sampling. Methods: This study utilizes a field deployable UV-Vis spectrophotometer (spectro::lyzer, s::can, Austria) to investigate how forest harvest affects DOC export. The sensor was installed at an existing hydrologic monitoring site at the outlet of a headwater stream draining a small (91 hectare) second growth Douglasfir-dominated catchment near Campbell River on Vancouver Island, British Columbia. Measurement began late in 2009, prior to forest harvest and associated activities such as road building (which commenced in October 2010 and ended in early 2011), and continues to present. During this time - encompassing the pre, during and post-harvest conditions - the absorbance spectrum of stream water from 200 to 750 nm was measured. DOC concentration and spectroscopic indices related to DOC quality (including SUVA, which relates to the concentration of aromatic carbon, and spectral slope) were subsequently calculated for each spectra obtained at 30-minute intervals. Results and conclusions: High frequency measurements of DOC show that overall export of OM increased in

  20. Sensitive Bioanalysis Based on in-Situ Droplet Anodic Stripping Voltammetric Detection of CdS Quantum Dots Label after Enhanced Cathodic Preconcentration

    Directory of Open Access Journals (Sweden)

    Xiaoli Qin

    2016-08-01

    Full Text Available We report a protocol of CdS-labeled sandwich-type amperometric bioanalysis with high sensitivity, on the basis of simultaneous chemical-dissolution/cathodic-enrichment of the CdS quantum dot biolabel and anodic stripping voltammetry (ASV detection of Cd directly on the bioelectrode. We added a microliter droplet of 0.1 M aqueous HNO3 to dissolve CdS on the bioelectrode and simultaneously achieved the potentiostatic cathodic preconcentration of Cd by starting the potentiostatic operation before HNO3 addition, which can largely increase the ASV signal. Our protocol was used for immunoanalysis and aptamer-based bioanalysis of several proteins, giving limits of detection of 4.5 fg·mL−1 for human immunoglobulin G, 3.0 fg·mL−1 for human carcinoembryonic antigen (CEA, 4.9 fg·mL−1 for human α-fetoprotein (AFP, and 0.9 fM for thrombin, which are better than many reported results. The simultaneous and sensitive analysis of CEA and AFP at two screen-printed carbon electrodes was also conducted by our protocol.

  1. High frequency electrical stimulation concurrently induces central sensitization and ipsilateral inhibitory pain modulation.

    Science.gov (United States)

    Vo, L; Drummond, P D

    2013-03-01

    In healthy humans, analgesia to blunt pressure develops in the ipsilateral forehead during various forms of limb pain. The aim of the current study was to determine whether this analgesic response is induced by ultraviolet B radiation (UVB), which evokes signs of peripheral sensitization, or by high-frequency electrical stimulation (HFS), which triggers signs of central sensitization. Before and after HFS and UVB conditioning, sensitivity to heat and to blunt and sharp stimuli was assessed at and adjacent to the treated site in the forearm. In addition, sensitivity to blunt pressure was measured bilaterally in the forehead. The effect of ipsilateral versus contralateral temple cooling on electrically evoked pain in the forearm was then examined, to determine whether HFS or UVB conditioning altered inhibitory pain modulation. UVB conditioning triggered signs of peripheral sensitization, whereas HFS conditioning triggered signs of central sensitization. Importantly, ipsilateral forehead analgesia developed after HFS but not UVB conditioning. In addition, decreases in electrically evoked pain at the HFS-treated site were greater during ipsilateral than contralateral temple cooling, whereas decreases at the UVB-treated site were similar during both procedures. HFS conditioning induced signs of central sensitization in the forearm and analgesia both in the ipsilateral forehead and the HFS-treated site. This ipsilateral analgesia was not due to peripheral sensitization or other non-specific effects, as it failed to develop after UVB conditioning. Thus, the supra-spinal mechanisms that evoke central sensitization might also trigger a hemilateral inhibitory pain modulation process. This inhibitory process could sharpen the boundaries of central sensitization or limit its spread. © 2012 European Federation of International Association for the Study of Pain Chapters.

  2. In situ high-frequency UV-Vis spectrometer probes for investigating runoff processes and end member stability.

    Science.gov (United States)

    Schwab, Michael; Weiler, Markus; Pfister, Laurent; Klaus, Julian

    2014-05-01

    In recent years, several limitations as to the application of end member mixing analysis with isotope and geochemical tracers have been revealed: unstable end member solutions, inputs varying in space and time, and unrealistic mixing assumptions. In addition, the necessary high-frequency sampling using conventional methods is time and resources consuming, and hence most sampling rates are not suitable for capturing the response times of the majority of observed headwater catchments. However, high-frequency observations are considered fundamental for gaining new insights into hydrological systems. In our study, we have used two portable, in situ, high-frequency UV-Vis spectrometers (spectro::lyser; scan Messtechnik GmbH) to investigate the variability of several signatures in streamflow and end member stability. The spectro::lyser measures TOC, DOC, nitrate and the light absorption spectrum from 220 to 720 nm with 2.5 nm increment. The Weierbach catchment (0.45 km2) in the Attert basin (297 km2) in Luxemburg is a small headwater research catchment (operated by the CRP Gabriel Lippmann), which is completely forested and underlain by schist bedrock. The catchment is equipped with a dense network of hydrological instruments and for this study, the outlet of the Weierbach catchment was equipped with one spectro::lyser, permanently sensing stream water at a 15 minutes time step over several months. Hydrometric and meteorologic data was compared with the high-frequency spectro::lyser time series of TOC, DOC, nitrate and the light absorption spectrum, to get a first insight into the behaviour of the catchment under different environmental conditions. As a preliminary step for a successful end member mixing analysis, the stability of rainfall, soil water, and groundwater was tested with one spectro::lyser, both temporally and spatially. Thereby, we focused on the investigation of changes and patterns of the light absorption spectrum of the different end members and the

  3. In Situ Mapping of the Molecular Arrangement of Amphiphilic Dye Molecules at the TiO 2 Surface of Dye-Sensitized Solar Cells

    KAUST Repository

    Voï tchovsky, Kislon; Ashari-Astani, Negar; Tavernelli, Ivano; Té treault, Nicolas; Rothlisberger, Ursula; Stellacci, Francesco; Grä tzel, Michael; Harms, Hauke A.

    2015-01-01

    © 2015 American Chemical Society. Amphiphilic sensitizers are central to the function of dye-sensitized solar cells. It is known that the cell's performance depends on the molecular arrangement and the density of the dye on the semiconductor surface

  4. Development of self-powered wireless high temperature electrochemical sensor for in situ corrosion monitoring of coal-fired power plant.

    Science.gov (United States)

    Aung, Naing Naing; Crowe, Edward; Liu, Xingbo

    2015-03-01

    Reliable wireless high temperature electrochemical sensor technology is needed to provide in situ corrosion information for optimal predictive maintenance to ensure a high level of operational effectiveness under the harsh conditions present in coal-fired power generation systems. This research highlights the effectiveness of our novel high temperature electrochemical sensor for in situ coal ash hot corrosion monitoring in combination with the application of wireless communication and an energy harvesting thermoelectric generator (TEG). This self-powered sensor demonstrates the successful wireless transmission of both corrosion potential and corrosion current signals to a simulated control room environment. Copyright © 2014 ISA. All rights reserved.

  5. Epidermis Microstructure Inspired Graphene Pressure Sensor with Random Distributed Spinosum for High Sensitivity and Large Linearity.

    Science.gov (United States)

    Pang, Yu; Zhang, Kunning; Yang, Zhen; Jiang, Song; Ju, Zhenyi; Li, Yuxing; Wang, Xuefeng; Wang, Danyang; Jian, Muqiang; Zhang, Yingying; Liang, Renrong; Tian, He; Yang, Yi; Ren, Tian-Ling

    2018-03-27

    Recently, wearable pressure sensors have attracted tremendous attention because of their potential applications in monitoring physiological signals for human healthcare. Sensitivity and linearity are the two most essential parameters for pressure sensors. Although various designed micro/nanostructure morphologies have been introduced, the trade-off between sensitivity and linearity has not been well balanced. Human skin, which contains force receptors in a reticular layer, has a high sensitivity even for large external stimuli. Herein, inspired by the skin epidermis with high-performance force sensing, we have proposed a special surface morphology with spinosum microstructure of random distribution via the combination of an abrasive paper template and reduced graphene oxide. The sensitivity of the graphene pressure sensor with random distribution spinosum (RDS) microstructure is as high as 25.1 kPa -1 in a wide linearity range of 0-2.6 kPa. Our pressure sensor exhibits superior comprehensive properties compared with previous surface-modified pressure sensors. According to simulation and mechanism analyses, the spinosum microstructure and random distribution contribute to the high sensitivity and large linearity range, respectively. In addition, the pressure sensor shows promising potential in detecting human physiological signals, such as heartbeat, respiration, phonation, and human motions of a pushup, arm bending, and walking. The wearable pressure sensor array was further used to detect gait states of supination, neutral, and pronation. The RDS microstructure provides an alternative strategy to improve the performance of pressure sensors and extend their potential applications in monitoring human activities.

  6. High degree gravitational sensitivity from Mars orbiters for the GMM-1 gravity model

    Science.gov (United States)

    Lerch, F. J.; Smith, D. E.; Chan, J. C.; Patel, G. B.; Chinn, D. S.

    1994-01-01

    Orbital sensitivity of the gravity field for high degree terms (greater than 30) is analyzed on satellites employed in a Goddard Mars Model GMM-1, complete in spherical harmonics through degree and order 50. The model is obtained from S-band Doppler data on Mariner 9 (M9), Viking Orbiter 1 (VO1), and Viking Orbiter 2 (VO2) spacecraft, which were tracked by the NASA Deep Space Network on seven different highly eccentric orbits. The main sensitivity of the high degree terms is obtained from the VO1 and VO2 low orbits (300 km periapsis altitude), where significant spectral sensitivity is seen for all degrees out through degree 50. The velocity perturbations show a dominant effect at periapsis and significant effects out beyond the semi-latus rectum covering over 180 degrees of the orbital groundtrack for the low altitude orbits. Because of the wideband of periapsis motion covering nearly 180 degrees in w and +39 degrees in latitude coverage, the VO1 300 km periapsis altitude orbit with inclination of 39 degrees gave the dominant sensitivity in the GMM-1 solution for the high degree terms. Although the VO2 low periapsis orbit has a smaller band of periapsis mapping coverage, it strongly complements the VO1 orbit sensitivity for the GMM-1 solution with Doppler tracking coverage over a different inclination of 80 degrees.

  7. Flexible hemispheric microarrays of highly pressure-sensitive sensors based on breath figure method.

    Science.gov (United States)

    Wang, Zhihui; Zhang, Ling; Liu, Jin; Jiang, Hao; Li, Chunzhong

    2018-05-30

    Recently, flexible pressure sensors featuring high sensitivity, broad sensing range and real-time detection have aroused great attention owing to their crucial role in the development of artificial intelligent devices and healthcare systems. Herein, highly sensitive pressure sensors based on hemisphere-microarray flexible substrates are fabricated via inversely templating honeycomb structures deriving from a facile and static breath figure process. The interlocked and subtle microstructures greatly improve the sensing characteristics and compressibility of the as-prepared pressure sensor, endowing it a sensitivity as high as 196 kPa-1 and a wide pressure sensing range (0-100 kPa), as well as other superior performance, including a lower detection limit of 0.5 Pa, fast response time (10 000 cycles). Based on the outstanding sensing performance, the potential capability of our pressure sensor in capturing physiological information and recognizing speech signals has been demonstrated, indicating promising application in wearable and intelligent electronics.

  8. Photon Counting System for High-Sensitivity Detection of Bioluminescence at Optical Fiber End.

    Science.gov (United States)

    Iinuma, Masataka; Kadoya, Yutaka; Kuroda, Akio

    2016-01-01

    The technique of photon counting is widely used for various fields and also applicable to a high-sensitivity detection of luminescence. Thanks to recent development of single photon detectors with avalanche photodiodes (APDs), the photon counting system with an optical fiber has become powerful for a detection of bioluminescence at an optical fiber end, because it allows us to fully use the merits of compactness, simple operation, highly quantum efficiency of the APD detectors. This optical fiber-based system also has a possibility of improving the sensitivity to a local detection of Adenosine triphosphate (ATP) by high-sensitivity detection of the bioluminescence. In this chapter, we are introducing a basic concept of the optical fiber-based system and explaining how to construct and use this system.

  9. A Flexible and Highly Sensitive Piezoresistive Pressure Sensor Based on Micropatterned Films Coated with Carbon Nanotubes

    Directory of Open Access Journals (Sweden)

    Jia-lin Yao

    2016-01-01

    Full Text Available Excellent flexibility, high sensitivity, and low consumption are essential characteristics in flexible microtube pressure sensing occasion, for example, implantable medical devices, industrial pipeline, and microfluidic chip. This paper reports a flexible, highly sensitive, and ultrathin piezoresistive pressure sensor for fluid pressure sensing, whose sensing element is micropatterned films with conductive carbon nanotube layer. The flexible pressure sensor, the thickness of which is 40 ± 10 μm, could be economically fabricated by using biocompatible polydimethylsiloxane (PDMS. Experimental results show that the flexible pressure sensor has high sensitivity (0.047 kPa−1 in gas sensing and 5.6 × 10−3 kPa−1 in liquid sensing and low consumption (<180 μW, and the sensor could be used to measure the pressure in curved microtubes.

  10. Multimode fiber tip Fabry-Perot cavity for highly sensitive pressure measurement.

    Science.gov (United States)

    Chen, W P; Wang, D N; Xu, Ben; Zhao, C L; Chen, H F

    2017-03-23

    We demonstrate an optical Fabry-Perot interferometer fiber tip sensor based on an etched end of multimode fiber filled with ultraviolet adhesive. The fiber device is miniature (with diameter of less than 60 μm), robust and low cost, in a convenient reflection mode of operation, and has a very high gas pressure sensitivity of -40.94 nm/MPa, a large temperature sensitivity of 213 pm/°C within the range from 55 to 85 °C, and a relatively low temperature cross-sensitivity of 5.2 kPa/°C. This device has a high potential in monitoring environment of high pressure.

  11. A highly sensitive CMOS digital Hall sensor for low magnetic field applications.

    Science.gov (United States)

    Xu, Yue; Pan, Hong-Bin; He, Shu-Zhuan; Li, Li

    2012-01-01

    Integrated CMOS Hall sensors have been widely used to measure magnetic fields. However, they are difficult to work with in a low magnetic field environment due to their low sensitivity and large offset. This paper describes a highly sensitive digital Hall sensor fabricated in 0.18 μm high voltage CMOS technology for low field applications. The sensor consists of a switched cross-shaped Hall plate and a novel signal conditioner. It effectively eliminates offset and low frequency 1/f noise by applying a dynamic quadrature offset cancellation technique. The measured results show the optimal Hall plate achieves a high current related sensitivity of about 310 V/AT. The whole sensor has a remarkable ability to measure a minimum ± 2 mT magnetic field and output a digital Hall signal in a wide temperature range from -40 °C to 120 °C.

  12. In situ high-resolution evaluation of labile arsenic and mercury in sediment of a large shallow lake

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Chao; Yao, Yu; Wang, Peifang; Hou, Jun; Qian, Jin; Yuan, Ye; Fan, Xiulei

    2016-01-15

    The precise evaluation of arsenic (As) and mercury (Hg) bioavailability in sediment is crucial to controlling As and Hg contamination, but traditional ex situ measurements hamper comprehensive analysis of labile As and Hg in sediment. In this study, we characterized in situ labile As and Hg in sediment of Lake Hongze using the zirconium (Zr) oxide diffusive gradients in thin films (DGT) technique and 3-mercaptopropyl functionalized silica gel DGT, respectively. The concentrations of DGT-labile As and Hg in the sediment profiles were found to exhibit considerable variation, ranging from 0.15 to 4.15 μg L{sup −1} for As and from 0.04 to 1.35 μg L{sup −1} for Hg. As and Hg flux values, calculated based on the concentration gradients measured from the DGT profiles for both the overlying water and sediment close to the sediment–water interface, were used to determine the contamination status of As and Hg. Flux values of As and Hg were between − 0.066 and 0.067 ng cm{sup −2} d{sup −1} and between − 0.0187 and 0.0181 ng cm{sup −2} d{sup −1}, respectively. The GNU's Not Unix R (GNU R) programming language was used to identify outliers of As and Hg at various depths at the sampling sites. The results indicate that the sites with the most outliers were all located in the regions that were seriously affected by contaminants from the Huai River. The DGT-labile As and Hg concentrations in the 0–30 mm layer were found to be significantly correlated with concentrations of labile As and Hg, total dissolved As and Hg, and total As and Hg in the overlying water, as indicated by ex situ measurements. Results show that DGT is a reliable and high-resolution technique that can be used for in situ monitoring of the labile fractions of As and Hg in sediment in fresh water bodies. - Graphical abstract: The principle of DGT is based on the diffusion of dissolved species through a well-defined gel and subsequent accumulation on an ion-exchange resin. A diffusion

  13. In situ high-resolution evaluation of labile arsenic and mercury in sediment of a large shallow lake

    International Nuclear Information System (INIS)

    Wang, Chao; Yao, Yu; Wang, Peifang; Hou, Jun; Qian, Jin; Yuan, Ye; Fan, Xiulei

    2016-01-01

    The precise evaluation of arsenic (As) and mercury (Hg) bioavailability in sediment is crucial to controlling As and Hg contamination, but traditional ex situ measurements hamper comprehensive analysis of labile As and Hg in sediment. In this study, we characterized in situ labile As and Hg in sediment of Lake Hongze using the zirconium (Zr) oxide diffusive gradients in thin films (DGT) technique and 3-mercaptopropyl functionalized silica gel DGT, respectively. The concentrations of DGT-labile As and Hg in the sediment profiles were found to exhibit considerable variation, ranging from 0.15 to 4.15 μg L −1 for As and from 0.04 to 1.35 μg L −1 for Hg. As and Hg flux values, calculated based on the concentration gradients measured from the DGT profiles for both the overlying water and sediment close to the sediment–water interface, were used to determine the contamination status of As and Hg. Flux values of As and Hg were between − 0.066 and 0.067 ng cm −2 d −1 and between − 0.0187 and 0.0181 ng cm −2 d −1 , respectively. The GNU's Not Unix R (GNU R) programming language was used to identify outliers of As and Hg at various depths at the sampling sites. The results indicate that the sites with the most outliers were all located in the regions that were seriously affected by contaminants from the Huai River. The DGT-labile As and Hg concentrations in the 0–30 mm layer were found to be significantly correlated with concentrations of labile As and Hg, total dissolved As and Hg, and total As and Hg in the overlying water, as indicated by ex situ measurements. Results show that DGT is a reliable and high-resolution technique that can be used for in situ monitoring of the labile fractions of As and Hg in sediment in fresh water bodies. - Graphical abstract: The principle of DGT is based on the diffusion of dissolved species through a well-defined gel and subsequent accumulation on an ion-exchange resin. A diffusion gel and a filter membrane (to

  14. A comparison between different oxide dispersion strengthened ferritic steel ongoing in situ oxide dissolution in High Voltage Electron Microscope

    International Nuclear Information System (INIS)

    Monnet, I.; Van den Berghe, T.; Dubuisson, Ph.

    2012-01-01

    ODS materials are considered for nuclear applications but previous experimental studies have shown a partial dissolution of some oxides under neutron irradiation. In this work, electron irradiations were used to evaluate the stability of the oxides depending on the chemical composition of the oxide dispersion. Four ferritic steels based on EM10 (Fe–9Cr–1Mo) and reinforced respectively by Al 2 O 3 , MgO, MgAl 2 O 4 and Y 2 O 3 , were studied. These materials were irradiated with 1 MeV or 1.2 MeV electrons in a High Voltage Electron Microscope. This technique allows to follow one single oxide and to determine the evolution of its size during the irradiation. In situ HVEM observations indicate that the dissolution rate depends on the chemical composition of the oxide, on the temperature and on the irradiation dose.

  15. High precision AlGaAsSb ridge-waveguide etching by in situ reflectance monitored ICP-RIE

    Science.gov (United States)

    Tran, N. T.; Breivik, Magnus; Patra, S. K.; Fimland, Bjørn-Ove

    2014-05-01

    GaSb-based semiconductor diode lasers are promising candidates for light sources working in the mid-infrared wavelength region of 2-5 μm. Using edge emitting lasers with ridge-waveguide structure, light emission with good beam quality can be achieved. Fabrication of the ridge waveguide requires precise etch stop control for optimal laser performance. Simulation results are presented that show the effect of increased confinement in the waveguide when the etch depth is well-defined. In situ reflectance monitoring with a 675 nm-wavelength laser was used to determine the etch stop with high accuracy. Based on the simulations of laser reflectance from a proposed sample, the etching process can be controlled to provide an endpoint depth precision within +/- 10 nm.

  16. High-temperature dehydration of talc: a kinetics study using in situ X-ray powder diffraction

    Science.gov (United States)

    Wang, Duojun; Yi, Li; Huang, Bojin; Liu, Chuanjiang

    2015-06-01

    High-temperature in situ X-ray powder diffraction patterns were used to study the dehydration kinetics of natural talc with a size of 10-15 µm. The talc was annealed from 1073 to 1223 K, and the variations in the characteristic peaks corresponding to talc with the time were recorded to determine the reaction progress. The decomposition of talc occurred, and peaks corresponding to talc and peaks corresponding to enstatite and quartz were observed. The enstatite and talc exhibited a topotactic relationship. The dehydration kinetics of talc was studied as a function of temperature between 1073 and 1223 K. The kinetics data could be modeled using an Avrami equation that considers nucleation and growth processes ? where n varies from 0.4 to 0.8. The rate constant (k) equation for the natural talc is ? The reaction mechanism for the dehydration of talc is a heterogeneous nucleation and growth mechanism.

  17. Phase transformation in sol-gel prepared zirconia using in-situ high temperature X-ray diffraction

    International Nuclear Information System (INIS)

    Srinivasan, R.; Davis, B.H.; Hubbard, C.R.; Cavin, O.B.; Porter, W.D.

    1991-01-01

    Zirconia was precipitated at a pH of 10.5 by admixing a solution of ZrCl 4 and NH 4 OH both rapidly (∼ 1 min) and slowly (∼ 8 hr). The precipitate was calcined at 500C for 5 hours and then furnace cooled. The former exhibited monoclinic phase while the latter yielded tetragonal phase. The pathway from amorphous to crystalline form was followed by in-situ high temperature X-ray diffraction in flowing air and in He. The data showed the evolution of the tetragonal crystalline phase on heating. On rapid cooling the tetragonal phase is retained at R.T., and on slow cooling the transformation to monoclinic phase occurs in air

  18. Determination of gene expression patterns using high-throughput RNA in situ hybridizaion to whole-mount Drosophila embryos

    Energy Technology Data Exchange (ETDEWEB)

    Weiszmann, R.; Hammonds, A.S.; Celniker, S.E.

    2009-04-09

    We describe a high-throughput protocol for RNA in situ hybridization (ISH) to Drosophila embryos in a 96-well format. cDNA or genomic DNA templates are amplified by PCR and then digoxigenin-labeled ribonucleotides are incorporated into antisense RNA probes by in vitro transcription. The quality of each probe is evaluated before ISH using a RNA probe quantification (dot blot) assay. RNA probes are hybridized to fixed, mixed-staged Drosophila embryos in 96-well plates. The resulting stained embryos can be examined and photographed immediately or stored at 4oC for later analysis. Starting with fixed, staged embryos, the protocol takes 6 d from probe template production through hybridization. Preparation of fixed embryos requires a minimum of 2 weeks to collect embryos representing all stages. The method has been used to determine the expression patterns of over 6,000 genes throughout embryogenesis.

  19. Synergetic enhancement of gold nanoparticles and 2-mercaptobenzothiazole as highly-sensitive sensing strategy for tetrabromobisphenol A

    Science.gov (United States)

    Chen, Xuerong; Ji, Liudi; Zhou, Yikai; Wu, Kangbing

    2016-05-01

    Various gold nanoparticles (AuNPs) were in-situ prepared on the electrode surface through electrochemical reduction under different potentials such as -0.60, -0.50, -0.40, -0.30 and -0.20 V. The reduction potentials heavily affect the surface morphology and electrochemical activity of AuNPs such as effective area and catalytic ability, as confirmed using atomic force microscopy and electrochemical impedance spectroscopy. The electrochemical behaviors of tetrabromobisphenol A (TBBPA), a widely-existed pollutant with severe adverse health effects, were studied. The oxidation activity of TBBPA enhances obviously on the surface of AuNPs, and the signal improvements of TBBPA show difference on the prepared AuNPs. Interestingly, the existence of 2-mercaptobenzothiazole (MBT) further improves the oxidation signals of TBBPA on AuNPs. The synergetic enhancement effects of AuNPs and MBT were studied using cyclic voltammetry and chronocoulometry. The numerous nano-scaled gold particles together with the strong hydrophobic interaction between TBBPA and the assembled MBT on AuNPs jointly provide highly-effective accumulation for TBBPA. As a result, a sensitive and simple electrochemical method was developed for the direct determination of TBBPA, with detection limit of 0.12 μg L-1 (0.22 nM). The practical applications in water samples manifest that this new sensing system is accurate and feasible.

  20. Hierarchical Mn₂O₃ Microspheres In-Situ Coated with Carbon for Supercapacitors with Highly Enhanced Performances.

    Science.gov (United States)

    Gong, Feilong; Lu, Shuang; Peng, Lifang; Zhou, Jing; Kong, Jinming; Jia, Dianzeng; Li, Feng

    2017-11-23

    Porous Mn₂O₃ microspheres have been synthesized and in-situ coated with amorphous carbon to form hierarchical C@Mn₂O₃ microspheres by first producing MnCO₃ microspheres in solvothermal reactions, and then annealing at 500 °C. The self-assembly growth of MnCO₃ microspheres can generate hollow structures inside each of the particles, which can act as micro-reservoirs to store biomass-glycerol for generating amorphous carbon onto the surfaces of Mn₂O₃ nanorods consisting of microspheres. The C@Mn₂O₃ microspheres, prepared at 500 °C, exhibit highly enhanced pseudocapacitive performances when compared to the particles after annealed at 400 °C and 600 °C. Specifically, the C@Mn₂O₃ microspheres prepared at 500 °C show high specific capacitances of 383.87 F g -1 at current density of 0.5 A g -1 , and excellent cycling stability of 90.47% of its initial value after cycling for 5000 times. The asymmetric supercapacitors assembled with C@Mn₂O₃ microspheres after annealed at 500 °C and activated carbon (AC) show an energy density of up to 77.8 Wh kg -1 at power density of 500.00 W kg -1 , and a maximum power density of 20.14 kW kg -1 at energy density of 46.8 Wh kg -1 . We can attribute the enhanced electrochemical performances of the materials to their three-dimensional (3D) hierarchical structure in-situ coated with carbon.

  1. Hierarchical Mn2O3 Microspheres In-Situ Coated with Carbon for Supercapacitors with Highly Enhanced Performances

    Science.gov (United States)

    Gong, Feilong; Lu, Shuang; Peng, Lifang; Zhou, Jing; Kong, Jinming; Jia, Dianzeng; Li, Feng

    2017-01-01

    Porous Mn2O3 microspheres have been synthesized and in-situ coated with amorphous carbon to form hierarchical C@Mn2O3 microspheres by first producing MnCO3 microspheres in solvothermal reactions, and then annealing at 500 °C. The self-assembly growth of MnCO3 microspheres can generate hollow structures inside each of the particles, which can act as micro-reservoirs to store biomass-glycerol for generating amorphous carbon onto the surfaces of Mn2O3 nanorods consisting of microspheres. The C@Mn2O3 microspheres, prepared at 500 °C, exhibit highly enhanced pseudocapacitive performances when compared to the particles after annealed at 400 °C and 600 °C. Specifically, the C@Mn2O3 microspheres prepared at 500 °C show high specific capacitances of 383.87 F g−1 at current density of 0.5 A g−1, and excellent cycling stability of 90.47% of its initial value after cycling for 5000 times. The asymmetric supercapacitors assembled with C@Mn2O3 microspheres after annealed at 500 °C and activated carbon (AC) show an energy density of up to 77.8 Wh kg−1 at power density of 500.00 W kg−1, and a maximum power density of 20.14 kW kg−1 at energy density of 46.8 Wh kg−1. We can attribute the enhanced electrochemical performances of the materials to their three-dimensional (3D) hierarchical structure in-situ coated with carbon. PMID:29168756

  2. Hierarchical Mn2O3 Microspheres In-Situ Coated with Carbon for Supercapacitors with Highly Enhanced Performances

    Directory of Open Access Journals (Sweden)

    Feilong Gong

    2017-11-01

    Full Text Available Porous Mn2O3 microspheres have been synthesized and in-situ coated with amorphous carbon to form hierarchical C@Mn2O3 microspheres by first producing MnCO3 microspheres in solvothermal reactions, and then annealing at 500 °C. The self-assembly growth of MnCO3 microspheres can generate hollow structures inside each of the particles, which can act as micro-reservoirs to store biomass-glycerol for generating amorphous carbon onto the surfaces of Mn2O3 nanorods consisting of microspheres. The C@Mn2O3 microspheres, prepared at 500 °C, exhibit highly enhanced pseudocapacitive performances when compared to the particles after annealed at 400 °C and 600 °C. Specifically, the C@Mn2O3 microspheres prepared at 500 °C show high specific capacitances of 383.87 F g−1 at current density of 0.5 A g−1, and excellent cycling stability of 90.47% of its initial value after cycling for 5000 times. The asymmetric supercapacitors assembled with C@Mn2O3 microspheres after annealed at 500 °C and activated carbon (AC show an energy density of up to 77.8 Wh kg−1 at power density of 500.00 W kg−1, and a maximum power density of 20.14 kW kg−1 at energy density of 46.8 Wh kg−1. We can attribute the enhanced electrochemical performances of the materials to their three-dimensional (3D hierarchical structure in-situ coated with carbon.

  3. In situ high-temperature gas sensors: continuous monitoring of the combustion quality of different wood combustion systems and optimization of combustion process

    Directory of Open Access Journals (Sweden)

    H. Kohler

    2018-03-01

    Full Text Available The sensing characteristics and long-term stability of different kinds of CO ∕ HC gas sensors (non-Nernstian mixed potential type during in situ operation in flue gas from different types of low-power combustion systems (wood-log- and wood-chip-fuelled were investigated. The sensors showed representative but individual sensing behaviour with respect to characteristically varying flue gas composition over the combustion process. The long-term sensor signal stability evaluated by repeated exposure to CO ∕ H2 ∕ N2 ∕ synthetic air mixtures showed no sensitivity loss after operation in the flue gas. Particularly for one of the sensors (Heraeus GmbH, this high signal stability was observed in a field test experiment even during continuous operation in the flue gas of the wood-chip firing system over 4 months. Furthermore, it was experimentally shown that the signals of these CO ∕ HC sensing elements yield important additional information about the wood combustion process. This was demonstrated by the adaptation of an advanced combustion airstream control algorithm on a wood-log-fed fireplace and by the development of a combustion quality monitoring system for wood-chip-fed central heaters.

  4. Undergraduate Neuropharmacology: A Model for Delivering College-Level Neuroscience to High School Students in situ.

    Science.gov (United States)

    Martin-Morris, Linda E; Buckland, Helen T; Popa, Simina M; Cunningham, Susanna L

    2015-01-01

    Our university course for non-majors (Biology 100) on the neurobiology of drug addiction was recently retooled for delivery at high schools around the state of Washington in order to engage younger students in the study of psychoactive drugs. Many of these students are earning both high school and university credits (dual-enrollment). This paper outlines the course design principles we used to ensure that high school students are earning valid college credits. We present an analysis of learning gains experienced by both university and high school students as measured by before and after course knowledge surveys. We also describe how assessment strategies used for on-campus students have been transferred to our high school partner teachers and how generous interchange and observation ensure that the high school students are engaging deeply in their study of neuroscience. Indeed, many have had a transformative experience that inspires them to contemplate the field of neuroscience as they transition into university study.

  5. Real-time, single-step bioassay using nanoplasmonic resonator with ultra-high sensitivity

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Xiang; Ellman, Jonathan A; Chen, Fanqing Frank; Su, Kai-Hang; Wei, Qi-Huo; Sun, Cheng

    2014-04-01

    A nanoplasmonic resonator (NPR) comprising a metallic nanodisk with alternating shielding layer(s), having a tagged biomolecule conjugated or tethered to the surface of the nanoplasmonic resonator for highly sensitive measurement of enzymatic activity. NPRs enhance Raman signals in a highly reproducible manner, enabling fast detection of protease and enzyme activity, such as Prostate Specific Antigen (paPSA), in real-time, at picomolar sensitivity levels. Experiments on extracellular fluid (ECF) from paPSA-positive cells demonstrate specific detection in a complex bio-fluid background in real-time single-step detection in very small sample volumes.

  6. High sensitivity, high surface area Enzyme-linked Immunosorbent Assay (ELISA).

    Science.gov (United States)

    Singh, Harpal; Morita, Takahiro; Suzuki, Yuma; Shimojima, Masayuki; Le Van, An; Sugamata, Masami; Yang, Ming

    2015-01-01

    Enzyme-linked immunosorbent assays (ELISA) are considered the gold standard in the demonstration of various immunological reactions with an application in the detection of infectious diseases such as during outbreaks or in patient care. This study aimed to produce an ELISA-based diagnostic with an increased sensitivity of detection compared to the standard 96-well method in the immunologic diagnosis of infectious diseases. A '3DStack' was developed using readily available, low cost fabrication technologies namely nanoimprinting and press stamping with an increased surface area of 4 to 6 times more compared to 96-well plates. This was achieved by stacking multiple nanoimprinted polymer sheets. The flow of analytes between the sheets was enhanced by rotating the 3DStack and confirmed by Finite-Element (FE) simulation. An Immunoglobulin G (IgG) ELISA for the detection of antibodies in human serum raised against Rubella virus was performed for validation. An improved sensitivity of up to 1.9 folds higher was observed using the 3DStack compared to the standard method. The increased surface area of the 3DStack developed using nanoimprinting and press stamping technologies, and the flow pattern between sheets generated by rotating the 3DStack were potential contributors to a more sensitive ELISA-based diagnostic device.

  7. Homogeneous vertical ZnO nanorod arrays with high conductivity on an in situ Gd nanolayer

    KAUST Repository

    Flemban, Tahani H.; Singaravelu, Venkatesh; Devi, Assa Aravindh Sasikala; Roqan, Iman S.

    2015-01-01

    We demonstrate a novel, one-step, catalyst-free method for the production of size-controlled vertical highly conductive ZnO nanorod (NR) arrays with highly desirable characteristics by pulsed laser deposition using a Gd-doped ZnO target. Our study

  8. High Temperature and High Sensitive NOx Gas Sensor with Hetero-Junction Structure using Laser Ablation Method

    Science.gov (United States)

    Gao, Wei; Shi, Liqin; Hasegawa, Yuki; Katsube, Teruaki

    In order to develop a high temperature (200°C˜400°C) and high sensitive NOx gas sensor, we developed a new structure of SiC-based hetero-junction device Pt/SnO2/SiC/Ni, Pt/In2O3/SiC/Ni and Pt/WO3/SiC/Ni using a laser ablation method for the preparation of both metal (Pt) electrode and metal-oxide film. It was found that Pt/In2O3/SiC/Ni sensor shows higher sensitivity to NO2 gas compared with the Pt/SnO2/SiC/Ni and Pt/WO3/SiC/Ni sensor, whereas the Pt/WO3/SiC/Ni sensor had better sensitivity to NO gas. These results suggest that selective detection of NO and NO2 gases may be obtained by choosing different metal oxide films.

  9. Photorefractive keratectomy versus laser in situ keratomileusis for moderate to high myopia. A randomized prospective study.

    Science.gov (United States)

    Hersh, P S; Brint, S F; Maloney, R K; Durrie, D S; Gordon, M; Michelson, M A; Thompson, V M; Berkeley, R B; Schein, O D; Steinert, R F

    1998-08-01

    This report presents the results of a randomized clinical trial of photorefractive keratectomy (PRK) and laser-assisted in situ keratomileusis (LASIK). A randomized, prospective multicenter clinical trial. A total of 220 eyes of 220 patients entered the study cohort: 105 randomized to PRK and 115 to LASIK. The mean preoperative manifest refraction spherical equivalent was -9.23 diopters (D) in the PRK group and -9.30 D in the LASIK group. All patients received a one-pass, multizone excimer laser ablation as part of either a PRK or LASIK procedure using the Summit Apex excimer laser. Attempted corrections ranged from 6.00 to 15.00 D. Data on uncorrected and spectacle-corrected visual acuity, predictability,and stability of refraction, corneal haze, and flap complications were analyzed. Patients were observed for up to 6 months. One day after surgery, 0 (0.0%) and 3 (4.5%) eyes in the PRK group saw 20/20 and 20/40 or better uncorrected, respectively, while 7 (10%) and 48 (68.6%) eyes in the LASIK group saw 20/20 and 20/40 or better, respectively. At 6 months after PRK, 13 (19.1%) and 45 (66.2%) eyes saw 20/20 and 20/40 or better, respectively, while after LASIK, 16 (26.2%) and 34 (55.7%) eyes saw 20/20 and 20/40 or better, respectively (odds ratio = 0.56 for likelihood of uncorrected visual acuity PRK vs. LASIK, 95% confidence interval [CI] = 0.31-1.19). After PRK, 39 eyes (57.4%) were within 1.0 D of attempted correction compared with 24 eyes (40.7%) in the LASIK group (odds ratio = 0.50 for likelihood fo undercorrection 1.0 D for PRK vs. LASIK, 95% CI = 0.24-1.04); however, the standard deviation of the predictability was similar between groups: 1.01 D for PRK and 1.22 D for LASIK. From months 1 to 6, there was an average regression of 0.89 D in the PRK group and 0.55 D in the LASIK group. After PRK, eight eyes (11.8%) had a decrease in spectacle-corrected visual acuity of two Snellen lines or more; after LASIK, two eyes (3.2%) had a decrease of two lines or more

  10. The nature and nurture of high IQ: an extended sensitive period for intellectual development.

    Science.gov (United States)

    Brant, Angela M; Munakata, Yuko; Boomsma, Dorret I; Defries, John C; Haworth, Claire M A; Keller, Matthew C; Martin, Nicholas G; McGue, Matthew; Petrill, Stephen A; Plomin, Robert; Wadsworth, Sally J; Wright, Margaret J; Hewitt, John K

    2013-08-01

    IQ predicts many measures of life success, as well as trajectories of brain development. Prolonged cortical thickening observed in individuals with high IQ might reflect an extended period of synaptogenesis and high environmental sensitivity or plasticity. We tested this hypothesis by examining the timing of changes in the magnitude of genetic and environmental influences on IQ as a function of IQ score. We found that individuals with high IQ show high environmental influence on IQ into adolescence (resembling younger children), whereas individuals with low IQ show high heritability of IQ in adolescence (resembling adults), a pattern consistent with an extended sensitive period for intellectual development in more-intelligent individuals. The pattern held across a cross-sectional sample of almost 11,000 twin pairs and a longitudinal sample of twins, biological siblings, and adoptive siblings.

  11. High Throughput Measurement of Locomotor Sensitization to Volatilized Cocaine in Drosophila melanogaster.

    Science.gov (United States)

    Filošević, Ana; Al-Samarai, Sabina; Andretić Waldowski, Rozi

    2018-01-01

    Drosophila melanogaster can be used to identify genes with novel functional roles in neuronal plasticity induced by repeated consumption of addictive drugs. Behavioral sensitization is a relatively simple behavioral output of plastic changes that occur in the brain after repeated exposures to drugs of abuse. The development of screening procedures for genes that control behavioral sensitization has stalled due to a lack of high-throughput behavioral tests that can be used in genetically tractable organism, such as Drosophila . We have developed a new behavioral test, FlyBong, which combines delivery of volatilized cocaine (vCOC) to individually housed flies with objective quantification of their locomotor activity. There are two main advantages of FlyBong: it is high-throughput and it allows for comparisons of locomotor activity of individual flies before and after single or multiple exposures. At the population level, exposure to vCOC leads to transient and concentration-dependent increase in locomotor activity, representing sensitivity to an acute dose. A second exposure leads to further increase in locomotion, representing locomotor sensitization. We validate FlyBong by showing that locomotor sensitization at either the population or individual level is absent in the mutants for circadian genes period (per) , Clock (Clk) , and cycle (cyc) . The locomotor sensitization that is present in timeless (tim) and pigment dispersing factor (pdf) mutant flies is in large part not cocaine specific, but derived from increased sensitivity to warm air. Circadian genes are not only integral part of the neural mechanism that is required for development of locomotor sensitization, but in addition, they modulate the intensity of locomotor sensitization as a function of the time of day. Motor-activating effects of cocaine are sexually dimorphic and require a functional dopaminergic transporter. FlyBong is a new and improved method for inducing and measuring locomotor sensitization

  12. High Throughput Measurement of Locomotor Sensitization to Volatilized Cocaine in Drosophila melanogaster

    Directory of Open Access Journals (Sweden)

    Ana Filošević

    2018-02-01

    Full Text Available Drosophila melanogaster can be used to identify genes with novel functional roles in neuronal plasticity induced by repeated consumption of addictive drugs. Behavioral sensitization is a relatively simple behavioral output of plastic changes that occur in the brain after repeated exposures to drugs of abuse. The development of screening procedures for genes that control behavioral sensitization has stalled due to a lack of high-throughput behavioral tests that can be used in genetically tractable organism, such as Drosophila. We have developed a new behavioral test, FlyBong, which combines delivery of volatilized cocaine (vCOC to individually housed flies with objective quantification of their locomotor activity. There are two main advantages of FlyBong: it is high-throughput and it allows for comparisons of locomotor activity of individual flies before and after single or multiple exposures. At the population level, exposure to vCOC leads to transient and concentration-dependent increase in locomotor activity, representing sensitivity to an acute dose. A second exposure leads to further increase in locomotion, representing locomotor sensitization. We validate FlyBong by showing that locomotor sensitization at either the population or individual level is absent in the mutants for circadian genes period (per, Clock (Clk, and cycle (cyc. The locomotor sensitization that is present in timeless (tim and pigment dispersing factor (pdf mutant flies is in large part not cocaine specific, but derived from increased sensitivity to warm air. Circadian genes are not only integral part of the neural mechanism that is required for development of locomotor sensitization, but in addition, they modulate the intensity of locomotor sensitization as a function of the time of day. Motor-activating effects of cocaine are sexually dimorphic and require a functional dopaminergic transporter. FlyBong is a new and improved method for inducing and measuring locomotor

  13. Facile fabrication of ultrathin hybrid membrane for highly flexible supercapacitors via in-situ phase separation of polyethersulfone

    Science.gov (United States)

    Zhao, Xiaoning; Ran, Fen; Shen, Kuiwen; Yang, Yunlong; Wu, Jiayu; Niu, Xiaoqin; Kong, Lingbin; Kang, Long; Chen, Shaowei

    2016-10-01

    In this article, a facile method based on in-situ phase-separation was developed for the fabrication of ultrathin hybrid membranes for highly flexible supercapacitors. The structures and morphologies of the prepared electrodes were characterized by scanning electron microscopy (SEM), Fourier-transformed infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA) measurements; and the electrochemical behaviors were examined in 2 M KOH solution. SEM and FTIR characterizations reveal that activated carbon was imbedded into the polymer membrane of polyethersulfone to form a uniform and flexible hybrid membrane. When the thin polymer-carbon membrane (PCM) was used as an electrode material for supercapacitor, a high specific capacitance of 169.4 Fg-1 was obtained at a current density of 0.5 Ag-1 along with good long-term cycle life of 94.6% capacity retention after 2000 charging-discharging cycles. Benefiting from these merits, the as-fabricated PCM//PCM cell shows an excellent electrochemical property. These results suggest a promising route towards the fabrication of highly flexible electrodes for high-performance supercapacitors.

  14. In situ synthesis of molecularly imprinted nanoparticles in porous support membranes using high-viscosity polymerization solvents.

    Science.gov (United States)

    Renkecz, Tibor; László, Krisztina; Horváth, Viola

    2012-06-01

    There is a growing need in membrane separations for novel membrane materials providing selective retention. Molecularly imprinted polymers (MIPs) are promising candidates for membrane functionalization. In this work, a novel approach is described to prepare composite membrane adsorbers incorporating molecularly imprinted microparticles or nanoparticles into commercially available macroporous filtration membranes. The polymerization is carried out in highly viscous polymerization solvents, and the particles are formed in situ in the pores of the support membrane. MIP particle composite membranes selective for terbutylazine were prepared and characterized by scanning electron microscopy and N₂ porosimetry. By varying the polymerization solvent microparticles or nanoparticles with diameters ranging from several hundred nanometers to 1 µm could be embedded into the support. The permeability of the membranes was in the range of 1000 to 20,000 Lm⁻²  hr⁻¹  bar⁻¹. The imprinted composite membranes showed high MIP/NIP (nonimprinted polymer) selectivity for the template in organic media both in equilibrium-rebinding measurements and in filtration experiments. The solid phase extraction of a mixture of the template, its analogs, and a nonrelated compound demonstrated MIP/NIP selectivity and substance selectivity of the new molecularly imprinted membrane. The synthesis technique offers a potential for the cost-effective production of selective membrane adsorbers with high capacity and high throughput. Copyright © 2012 John Wiley & Sons, Ltd.

  15. In Situ Observations of Thermoreversible Gelation and Phase Separation of Agarose and Methylcellulose Solutions under High Pressure.

    Science.gov (United States)

    Kometani, Noritsugu; Tanabe, Masahiro; Su, Lei; Yang, Kun; Nishinari, Katsuyoshi

    2015-06-04

    Thermoreversible sol-gel transitions of agarose and methylcellulose (MC) aqueous solutions on isobaric cooling or heating under high pressure up to 400 MPa have been investigated by in situ observations of optical transmittance and falling-ball experiments. For agarose, which undergoes the gelation on cooling, the application of pressure caused a gradual rise in the cloud-point temperature over the whole pressure range examined, which is almost consistent with the pressure dependence of gelling temperature estimated by falling-ball experiments, suggesting that agarose gel is stabilized by compression and that the gelation occurs nearly in parallel with phase separation under ambient and high-pressure conditions. For MC, which undergoes the gelation on heating, the cloud-point temperature showed a slight rise with an initial elevation of pressure up to ∼150 MPa, whereas it showed a marked depression above 200 MPa. In contrast, the gelling temperature of MC, which is nearly identical to the cloud-point temperature at ambient pressure, showed a monotonous rise with increasing pressure up to 350 MPa, which means that MC undergoes phase separation prior to gelation on heating under high pressure above 200 MPa. Similar results were obtained for the melting process of MC gel on cooling. The unique behavior of the sol-gel transition of MC under high pressure has been interpreted in terms of the destruction of hydrophobic hydration by compression.

  16. A highly sensitive RF-to-DC power converter with an extended dynamic range

    KAUST Repository

    Almansouri, Abdullah Saud Mohammed

    2017-10-24

    This paper proposes a highly sensitive RF-to-DC power converter with an extended dynamic range that is designed to operate at the medical band 433 MHz and simulated using 0.18 μm CMOS technology. Compared to the conventional fully cross-coupled rectifier, the proposed design offers 3.2× the dynamic range. It is also highly sensitive and requires −18 dBm of input power to produce a 1 V-output voltage when operating with a 100 kΩ load. Furthermore, the proposed design offers an open circuit sensitivity of −23.4 dBm and a peak power conversion efficiency of 67%.

  17. A wide range and highly sensitive optical fiber pH sensor using polyacrylamide hydrogel

    Science.gov (United States)

    Pathak, Akhilesh Kumar; Singh, Vinod Kumar

    2017-12-01

    In the present study we report the fabrication and characterization of no-core fiber sensor (NCFS) using smart hydrogel coating for pH measurement. The no-core fiber (NCF) is stubbed between two single-mode fibers with SMA connector before immobilizing of smart hydrogel. The wavelength interrogation technique is used to calculate the sensitivity of the proposed sensor. The result shows a high sensitivity of 1.94 nm/pH for a wide range of pH values varied from 3 to 10 with a good linear response. In addition to high sensitivity, the fabricated sensor provides a fast response time with a good stability, repeatability and reproducibility.

  18. High-sensitivity visualization of localized electric fields using low-energy electron beam deflection

    Science.gov (United States)

    Jeong, Samuel; Ito, Yoshikazu; Edwards, Gary; Fujita, Jun-ichi

    2018-06-01

    The visualization of localized electronic charges on nanocatalysts is expected to yield fundamental information about catalytic reaction mechanisms. We have developed a high-sensitivity detection technique for the visualization of localized charges on a catalyst and their corresponding electric field distribution, using a low-energy beam of 1 to 5 keV electrons and a high-sensitivity scanning transmission electron microscope (STEM) detector. The highest sensitivity for visualizing a localized electric field was ∼0.08 V/µm at a distance of ∼17 µm from a localized charge at 1 keV of the primary electron energy, and a weak local electric field produced by 200 electrons accumulated on the carbon nanotube (CNT) apex can be visualized. We also observed that Au nanoparticles distributed on a CNT forest tended to accumulate a certain amount of charges, about 150 electrons, at a ‑2 V bias.

  19. High Excitation Transfer Efficiency from Energy Relay Dyes in Dye-Sensitized Solar Cells

    KAUST Repository

    Hardin, Brian E.

    2010-08-11

    The energy relay dye, 4-(Dicyanomethylene)-2-methyl-6-(4- dimethylaminostyryl)-4H-pyran (DCM), was used with a near-infrared sensitizing dye, TT1, to increase the overall power conversion efficiency of a dye-sensitized solar cell (DSC) from 3.5% to 4.5%. The unattached DCM dyes exhibit an average excitation transfer efficiency (EÌ?TE) of 96% inside TT1-covered, mesostructured TiO2 films. Further performance increases were limited by the solubility of DCM in an acetonitrile based electrolyte. This demonstration shows that energy relay dyes can be efficiently implemented in optimized dye-sensitized solar cells, but also highlights the need to design highly soluble energy relay dyes with high molar extinction coefficients. © 2010 American Chemical Society.

  20. High sensitivity optical fiber liquid level sensor based on a compact MMF-HCF-FBG structure

    Science.gov (United States)

    Zhang, Yunshan; Zhang, Weigang; Chen, Lei; Zhang, Yanxin; Wang, Song; Yan, Tieyi

    2018-05-01

    An ultra-high sensitivity fiber liquid level sensor based on wavelength demodulation is proposed and demonstrated. The sensor is composed of a segment of multimode fiber and a large aperture hollow-core fiber assisted by a fiber Bragg grating (FBG). Interference occurs due to core mismatching and different modes with different effective refractive indices. The experimental results show that the liquid level sensitivity of the sensor is 1.145 nm mm‑1, and the linearity is up to 0.996. The dynamic temperature compensation of the sensor can be achieved by cascading an FBG. Considering the high sensitivity and compact structure of the sensor, it can be used for real-time intelligent monitoring of tiny changes in liquid level.

  1. Formation of soft magnetic high entropy amorphous alloys composites containing in situ solid solution phase

    Science.gov (United States)

    Wei, Ran; Sun, Huan; Chen, Chen; Tao, Juan; Li, Fushan

    2018-03-01

    Fe-Co-Ni-Si-B high entropy amorphous alloys composites (HEAACs), which containing high entropy solid solution phase in amorphous matrix, show good soft magnetic properties and bending ductility even in optimal annealed state, were successfully developed by melt spinning method. The crystallization phase of the HEAACs is solid solution phase with body centered cubic (BCC) structure instead of brittle intermetallic phase. In addition, the BCC phase can transformed into face centered cubic (FCC) phase with temperature rise. Accordingly, Fe-Co-Ni-Si-B high entropy alloys (HEAs) with FCC structure and a small amount of BCC phase was prepared by copper mold casting method. The HEAs exhibit high yield strength (about 1200 MPa) and good plastic strain (about 18%). Meanwhile, soft magnetic characteristics of the HEAs are largely reserved from HEAACs. This work provides a new strategy to overcome the annealing induced brittleness of amorphous alloys and design new advanced materials with excellent comprehensive properties.

  2. Niacin Skin Sensitivity Is Increased in Adolescents at Ultra-High Risk for Psychosis.

    Directory of Open Access Journals (Sweden)

    Gregor E Berger

    Full Text Available Most studies provide evidence that the skin flush response to nicotinic acid (niacin stimulation is impaired in schizophrenia. However, only little is known about niacin sensitivity in the ultra-high risk (UHR phase of psychotic disorders.We compared visual ratings of niacin sensitivity between adolescents at UHR for psychosis according to the one year transition outcome (UHR-T n = 11; UHR-NT n = 55 with healthy controls (HC n = 25 and first episode schizophrenia patients (FEP n = 25 treated with atypical antipsychotics.Contrary to our hypothesis niacin sensitivity of the entire UHR group was not attenuated, but significantly increased compared to the HC group, whereas no difference could be found between the UHR-T and UHR-NT groups. As expected, niacin sensitivity of FEP was attenuated compared to HC group. In UHR individuals niacin sensitivity was inversely correlated with omega-6 and -9 fatty acids (FA, but positively correlated with phospholipase A2 (inPLA2 activity, a marker of membrane lipid repair/remodelling.Increased niacin sensitivity in UHR states likely indicates an impaired balance of eicosanoids and omega-6/-9 FA at a membrane level. Our findings suggest that the emergence of psychosis is associated with an increased mobilisation of eicosanoids prior to the transition to psychosis possibly reflecting a "pro-inflammatory state", whereas thereafter eicosanoid mobilisation seems to be attenuated. Potential treatment implications for the UHR state should be further investigated.

  3. In situ one-pot preparation of reduced graphene oxide/polyaniline composite for high-performance electrochemical capacitors

    International Nuclear Information System (INIS)

    Chen, Nali; Ren, Yapeng; Kong, Peipei; Tan, Lin; Feng, Huixia; Luo, Yongchun

    2017-01-01

    Highlights: • A new method to prepare reduced graphene oxide/polyaniline composite is developed. • Aniline serves as a reduction for graphene oxide under weak alkali condition. • Different characterizations confirm that GO can be effectively reduced by aniline. • A high specific capacitance of 524.4 F·g"−"1 is obtained at 0.5 A·g"−"1. - Abstract: Reduced graphene oxide/polyaniline (rGO/PANI) composites are prepared through an effective in situ one-pot synthesis route that includes the reduction of graphene oxide (GO) by aniline under weak alkali condition via hydrothermal method and then followed by in situ polymerization of aniline. X-ray diffraction, Fourier transform infrared spectroscopy, Raman spectroscopy, ultraviolet-visible spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscope and transmission electron microscope are employed to reveal that GO is successfully reduced by aniline under weak alkali condition and PANI can be deposited on the surfaces of reduced graphene oxide (rGO) sheets. The effect of rGO is optimized by tuning the mass ratios of aniline to GO to improve the electrochemical performance of rGO/PANI composites. The maximum specific capacitance of rGO/PANI composites achieves 524.4 F/g with a mass ratio of aniline to GO 10:1 at a current density of 0.5 A/g, in comparison to the specific capacitance of 397 F/g at the same current density of pure PANI. Particularly, the specific capacity retention rate is 81.1% after 2000 cycles at 100 mv/s scan rate, which is an improvement over that of pure PANI (55.5%).

  4. In situ one-pot preparation of reduced graphene oxide/polyaniline composite for high-performance electrochemical capacitors

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Nali [College of Petrochemical Technology, Lanzhou University of Technology, Lanzhou 730050, Gansu (China); State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metals, Lanzhou University of Technology, Lanzhou 730050, Gansu (China); Ren, Yapeng; Kong, Peipei; Tan, Lin [College of Petrochemical Technology, Lanzhou University of Technology, Lanzhou 730050, Gansu (China); Feng, Huixia, E-mail: fenghx@lut.cn [College of Petrochemical Technology, Lanzhou University of Technology, Lanzhou 730050, Gansu (China); Luo, Yongchun, E-mail: luoyc@lut.cn [State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metals, Lanzhou University of Technology, Lanzhou 730050, Gansu (China)

    2017-01-15

    Highlights: • A new method to prepare reduced graphene oxide/polyaniline composite is developed. • Aniline serves as a reduction for graphene oxide under weak alkali condition. • Different characterizations confirm that GO can be effectively reduced by aniline. • A high specific capacitance of 524.4 F·g{sup −1} is obtained at 0.5 A·g{sup −1}. - Abstract: Reduced graphene oxide/polyaniline (rGO/PANI) composites are prepared through an effective in situ one-pot synthesis route that includes the reduction of graphene oxide (GO) by aniline under weak alkali condition via hydrothermal method and then followed by in situ polymerization of aniline. X-ray diffraction, Fourier transform infrared spectroscopy, Raman spectroscopy, ultraviolet-visible spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscope and transmission electron microscope are employed to reveal that GO is successfully reduced by aniline under weak alkali condition and PANI can be deposited on the surfaces of reduced graphene oxide (rGO) sheets. The effect of rGO is optimized by tuning the mass ratios of aniline to GO to improve the electrochemical performance of rGO/PANI composites. The maximum specific capacitance of rGO/PANI composites achieves 524.4 F/g with a mass ratio of aniline to GO 10:1 at a current density of 0.5 A/g, in comparison to the specific capacitance of 397 F/g at the same current density of pure PANI. Particularly, the specific capacity retention rate is 81.1% after 2000 cycles at 100 mv/s scan rate, which is an improvement over that of pure PANI (55.5%).

  5. Development of Charge Sensitive Preamplifier and Readout Integrate Circuit Board for High Resolution Detector using ASIC Process

    Energy Technology Data Exchange (ETDEWEB)

    Jeon, J. Y.; Kim, J. H.; Park, J. M.; Yang, J. Y.; Kim, K. Y.; Kim, Y. S. [RadTek Co., Daejeon (Korea, Republic of)

    2010-06-15

    - Design of discrete type charge sensitive amplifier for high resolution semi-conductor sensor - Design and develop the test board for the performance of charge sensitive amplifier with sensor - Performance of electrical test for the sensor and charge sensitive amplifier - Development of prototype 8 x 8 array type detector module - Noise equivalent charge test for the charge sensitive amplifier - Design and development of Micro SMD discrete type amplifier applying ASIC procedure - Development of Hybrid type charge sensitive amplifier including shape

  6. Optical and Microcantilever-Based Sensors for Real-Time In Situ Characterization of High-Level Waste

    International Nuclear Information System (INIS)

    Braun, Gilbert M.; Bryan, Samuel

    2002-01-01

    Fundamental research is being conducted to develop sensors for strontium that can be used in real-time to characterize high-level waste (HLW) process streams. Two fundamentally different approaches are being pursued, which have in common the dependence on highly selective molecular recognition agents. In one approach, an array of chemically selective sensors with sensitive fluorescent probes to signal the presence of the constituent of interest are coupled to fiber optics for remote analytical applications. The second approach employs sensitive microcantilever sensors that have been demonstrated to have unprecedented sensitivity in solution for Cs+ and CrO4 -. Selectivity in microcantilever-based sensors is achieved by modifying the surface of a gold-coated cantilever with a monolayer coating of an alkanethiol derivative of the molecular recognition agent. The approaches are complementary since fiber optic sensors can be deployed in the highly alkaline environment of HLW, bu t a method of immobilizing a fluorescent molecular recognition agents in a polymer film or bead on the surface of the optical fiber has yet to be demonstrated. The microcantilever-based sensors function by converting molecular complexation into surface stress, and they have been demonstrated to have the requisite sensitivity. However, we will investigate method of protecting Si or SiN microcantilever sensors in the highly alkaline environment of HLW while maintaining high selectivity. One objective of this project is to develop Sr(II) molecular recognition agents with rapidly established equilibria needed for real-time analysis, and initial research will focus on calixarene-crown ethers as a platform. Sensors for alkali metal ions, hydroxide, and temperature will be part of the array of sensor elements that will be demonstrated in this program for both the cantilever and fiber optic sensor approaches

  7. Development of a high sensitivity monitor for radionuclides characterization. Final report, August 1995--April 1996

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-06-01

    This report describes the development of a high sensitivity monitor for radiation, and the feasibility of applying a new radiation imaging concept developed for medical research to soil contamination. The concept utilizes sensors with storage photostimulable phosphor technology as radiation detectors. They are applicable to all types of radiation including tritium.

  8. High sensitivity of quick view capsule endoscopy for detection of small bowel Crohn's disease

    DEFF Research Database (Denmark)

    Halling, Morten Lee; Nathan, Torben; Kjeldsen, Jens

    2014-01-01

    Capsule endoscopy (CE) has a high sensitivity for diagnosing small bowel Crohn's disease, but video analysis is time consuming. The quick view (qv) function is an effective tool to reduce time consumption. The aim of this study was to determine the rate of missed small bowel ulcerations with qv-C...

  9. BH5047 type depth sand moisture-meter of high sensitivity

    International Nuclear Information System (INIS)

    Ji Changsong; Xie Liangnian; Zhang Shulan; Zhang Shuheng

    2000-01-01

    A new depth neutron moisture meter BH5047 has been developed. BH5047 neutron moisture meter is characterised by it is high sensitivity and used for sand water content measurement at concrete mixer. Calibration function is obtained by the Method of Least Squares. Linear correlation efficiency is as good as 0.9977

  10. Resting serum concentration of high-sensitivity C-reactive protein ...

    African Journals Online (AJOL)

    Resting serum concentration of high-sensitivity C-reactive protein (hs-CRP) in sportsmen and untrained male adults. F.A. Niyi-Odumosu, O. A. Bello, S.A. Biliaminu, B.V. Owoyele, T.O. Abu, O.L. Dominic ...

  11. A high resolution position sensitive X-ray MWPC for small angle X-ray diffraction

    International Nuclear Information System (INIS)

    Bateman, J.E.; Connolly, J.F.; Stephenson, R.; Tappern, G.J.

    1981-02-01

    A small sealed-off delay line readout MWPC X-ray detector has been designed and built for small angle X-ray diffraction applications. Featuring a sensitive area of 100 mm x 25 mm it yields a spatial resolution of 0.13 mm (standard deviation) with a high rate capability and good quantum efficiency for copper K radiation. (author)

  12. Highly sensitive luminescence method of scandium determination in the products of metallurgical reprocessing

    International Nuclear Information System (INIS)

    Matveets, M.A.; Akhmetova, S.D.

    1988-01-01

    Highly sensitive reaction of scandium with 1,10-phenanthroline and eosin is used for the development of luminescence method of its determination in metallurgical products. The effect of interfering elements is eliminated by scandium extraction with monocarboxylic acids. The method permits to determine scandium content from 5 x 10 -5 % (Sr 0.15 - 0.25)

  13. Label-free biosensing with high sensitivity in dual-core microstructured polymer optical fibers

    DEFF Research Database (Denmark)

    Markos, Christos; Yuan, Wu; Vlachos, Kyriakos

    2011-01-01

    We present experimentally feasible designs of a dual-core microstructured polymer optical fiber (mPOF), which can act as a highly sensitive, label-free, and selective biosensor. An immobilized antigen sensing layer on the walls of the holes in the mPOF provides the ability to selectively capture...

  14. Development of a high sensitivity monitor for radionuclides characterization. Final report, August 1995--April 1996

    International Nuclear Information System (INIS)

    1996-06-01

    This report describes the development of a high sensitivity monitor for radiation, and the feasibility of applying a new radiation imaging concept developed for medical research to soil contamination. The concept utilizes sensors with storage photostimulable phosphor technology as radiation detectors. They are applicable to all types of radiation including tritium

  15. A glycine residue essential for high ivermectin sensitivity in Cys-loop ion channel receptors

    DEFF Research Database (Denmark)

    Lynagh, Timothy; Lynch, Joseph W.

    2010-01-01

    Ivermectin exerts its anthelmintic effect by activating nematode Cys-loop glutamate-gated receptors. Here we show that a glycine residue at a specific transmembrane domain location is essential for high ivermectin sensitivity in both glycine- and glutamate-gated Cys-loop receptors. We also show...

  16. Association between high-sensitive troponin I and coronary artery calcification in a Danish general population

    DEFF Research Database (Denmark)

    Olson, Fredrik; Engborg, Jonathan; Grønhøj, Mette H.

    2016-01-01

    BACKGROUND: High-sensitive troponin I (hs-TnI) is an individual predictor of future cardiovascular disease (CVD). However, the relationship between hs-TnI and coronary artery calcification (CAC) as determined by computed tomography (CT) has not previously been investigated in a general population...

  17. A highly sensitive RF-to-DC power converter with an extended dynamic range

    KAUST Repository

    Almansouri, Abdullah Saud Mohammed; Ouda, Mahmoud H.; Salama, Khaled N.

    2017-01-01

    This paper proposes a highly sensitive RF-to-DC power converter with an extended dynamic range that is designed to operate at the medical band 433 MHz and simulated using 0.18 μm CMOS technology. Compared to the conventional fully cross

  18. Rats bred for high alcohol drinking are more sensitive to delayed and probabilistic outcomes.

    Science.gov (United States)

    Wilhelm, C J; Mitchell, S H

    2008-10-01

    Alcoholics and heavy drinkers score higher on measures of impulsivity than nonalcoholics and light drinkers. This may be because of factors that predate drug exposure (e.g. genetics). This study examined the role of genetics by comparing impulsivity measures in ethanol-naive rats selectively bred based on their high [high alcohol drinking (HAD)] or low [low alcohol drinking (LAD)] consumption of ethanol. Replicates 1 and 2 of the HAD and LAD rats, developed by the University of Indiana Alcohol Research Center, completed two different discounting tasks. Delay discounting examines sensitivity to rewards that are delayed in time and is commonly used to assess 'choice' impulsivity. Probability discounting examines sensitivity to the uncertain delivery of rewards and has been used to assess risk taking and risk assessment. High alcohol drinking rats discounted delayed and probabilistic rewards more steeply than LAD rats. Discount rates associated with probabilistic and delayed rewards were weakly correlated, while bias was strongly correlated with discount rate in both delay and probability discounting. The results suggest that selective breeding for high alcohol consumption selects for animals that are more sensitive to delayed and probabilistic outcomes. Sensitivity to delayed or probabilistic outcomes may be predictive of future drinking in genetically predisposed individuals.

  19. An UPLC-MS/MS method for highly sensitive high-throughput analysis of phytohormones in plant tissues

    Directory of Open Access Journals (Sweden)

    Balcke Gerd Ulrich

    2012-11-01

    Full Text Available Abstract Background Phytohormones are the key metabolites participating in the regulation of multiple functions of plant organism. Among them, jasmonates, as well as abscisic and salicylic acids are responsible for triggering and modulating plant reactions targeted against pathogens and herbivores, as well as resistance to abiotic stress (drought, UV-irradiation and mechanical wounding. These factors induce dramatic changes in phytohormone biosynthesis and transport leading to rapid local and systemic stress responses. Understanding of underlying mechanisms is of principle interest for scientists working in various areas of plant biology. However, highly sensitive, precise and high-throughput methods for quantification of these phytohormones in small samples of plant tissues are still missing. Results Here we present an LC-MS/MS method for fast and highly sensitive determination of jasmonates, abscisic and salicylic acids. A single-step sample preparation procedure based on mixed-mode solid phase extraction was efficiently combined with essential improvements in mobile phase composition yielding higher efficiency of chromatographic separation and MS-sensitivity. This strategy resulted in dramatic increase in overall sensitivity, allowing successful determination of phytohormones in small (less than 50 mg of fresh weight tissue samples. The method was completely validated in terms of analyte recovery, sensitivity, linearity and precision. Additionally, it was cross-validated with a well-established GC-MS-based procedure and its applicability to a variety of plant species and organs was verified. Conclusion The method can be applied for the analyses of target phytohormones in small tissue samples obtained from any plant species and/or plant part relying on any commercially available (even less sensitive tandem mass spectrometry instrumentation.

  20. Addressing Curse of Dimensionality in Sensitivity Analysis: How Can We Handle High-Dimensional Problems?

    Science.gov (United States)

    Safaei, S.; Haghnegahdar, A.; Razavi, S.

    2016-12-01

    Complex environmental models are now the primary tool to inform decision makers for the current or future management of environmental resources under the climate and environmental changes. These complex models often contain a large number of parameters that need to be determined by a computationally intensive calibration procedure. Sensitivity analysis (SA) is a very useful tool that not only allows for understanding the model behavior, but also helps in reducing the number of calibration parameters by identifying unimportant ones. The issue is that most global sensitivity techniques are highly computationally demanding themselves for generating robust and stable sensitivity metrics over the entire model response surface. Recently, a novel global sensitivity analysis method, Variogram Analysis of Response Surfaces (VARS), is introduced that can efficiently provide a comprehensive assessment of global sensitivity using the Variogram concept. In this work, we aim to evaluate the effectiveness of this highly efficient GSA method in saving computational burden, when applied to systems with extra-large number of input factors ( 100). We use a test function and a hydrological modelling case study to demonstrate the capability of VARS method in reducing problem dimensionality by identifying important vs unimportant input factors.

  1. A High-Sensitivity Potentiometric 65-nm CMOS ISFET Sensor for Rapid E. coli Screening.

    Science.gov (United States)

    Jiang, Yu; Liu, Xu; Dang, Tran Chien; Huang, Xiwei; Feng, Hao; Zhang, Qing; Yu, Hao

    2018-04-01

    Foodborne bacteria, inducing outbreaks of infection or poisoning, have posed great threats to food safety. Potentiometric sensors can identify bacteria levels in food by measuring medium's pH changes. However, most of these sensors face the limitation of low sensitivity and high cost. In this paper, we developed a high-sensitivity ion-sensitive field-effect transistor sensor. It is small sized, cost-efficient, and can be massively fabricated in a standard 65-nm complementary metal-oxide-semiconductor process. A subthreshold pH-to-time-to-voltage conversion scheme was proposed to improve the sensitivity. Furthermore, design parameters, such as chemical sensing area, transistor size, and discharging time, were optimized to enhance the performance. The intrinsic sensitivity of passivation membrane was calculated as 33.2 mV/pH. It was amplified to 123.8 mV/pH with a 0.01-pH resolution, which greatly exceeded 6.3 mV/pH observed in a traditional source-follower based readout structure. The sensing system was applied to Escherichia coli (E. coli) detection with densities ranging from 14 to 140 cfu/mL. Compared to the conventional direct plate counting method (24 h), more efficient sixfold smaller screening time (4 h) was achieved to differentiate samples' E. coli levels. The demonstrated portable, time-saving, and low-cost prescreen system has great potential for food safety detection.

  2. Polarization-sensitive and broadband germanium sulfide photodetectors with excellent high-temperature performance.

    Science.gov (United States)

    Tan, Dezhi; Zhang, Wenjin; Wang, Xiaofan; Koirala, Sandhaya; Miyauchi, Yuhei; Matsuda, Kazunari

    2017-08-31

    Layered materials, such as graphene, transition metal dichalcogenides and black phosphorene, have been established rapidly as intriguing building blocks for optoelectronic devices. Here, we introduce highly polarization sensitive, broadband, and high-temperature-operation photodetectors based on multilayer germanium sulfide (GeS). The GeS photodetector shows a high photoresponsivity of about 6.8 × 10 3 A W -1 , an extremely high specific detectivity of 5.6 × 10 14 Jones, and broad spectral response in the wavelength range of 300-800 nm. More importantly, the GeS photodetector has high polarization sensitivity to incident linearly polarized light, which provides another degree of freedom for photodetectors. Tremendously enhanced photoresponsivity is observed with a temperature increase, and high responsivity is achievable at least up to 423 K. The establishment of larger photoinduced reduction of the Schottky barrier height will be significant for the investigation of the photoresponse mechanism of 2D layered material-based photodetectors. These attributes of high photocurrent generation in a wide temperature range, broad spectral response, and polarization sensitivity coupled with environmental stability indicate that the proposed GeS photodetector is very suitable for optoelectronic applications.

  3. Temperature uniformity mapping in a high pressure high temperature reactor using a temperature sensitive indicator

    NARCIS (Netherlands)

    Grauwet, T.; Plancken, van der I.; Vervoort, L.; Matser, A.M.; Hendrickx, M.; Loey, van A.

    2011-01-01

    Recently, the first prototype ovomucoid-based pressure–temperature–time indicator (pTTI) for high pressure high temperature (HPHT) processing was described. However, for temperature uniformity mapping of high pressure (HP) vessels under HPHT sterilization conditions, this prototype needs to be

  4. High Sensitivity, Low Power Nano Sensors and Devices for Chemical Sensing

    Science.gov (United States)

    Li, Jing; Powell, Dan; Getty, Stephanie; Lu, Yi-Jiang

    2004-01-01

    The chemical sensor market has been projected to grow to better than $40 billion dollars worldwide within the next 10 years. Some of the primary motivations to develop nanostructured chemical sensors are monitoring and control of environmental pollution; improved diagnostics for consumption; improvement in measurement precision and accuracy; and improved detection limits for Homeland security, battlefield environments, and process and quality control of industrial applications. In each of these applications, there is demand for sensitivity, selectivity and stability of environmental and biohazard detection and capture beyond what is currently commercially available. Nanotechnology offers the ability to work at the molecular level, atom by atom, to create large structures with fundamentally new molecular organization. It is essentially concerned with materials, devices, and systems whose structures and components exhibit novel and significantly improved physical, chemical and biological properties, phenomena, and process control due to their nanoscale size. One such nanotechnology-enabled chemical sensor has been developed at NASA Ames leveraging nanostructures, such as single walled carbon nanotubes (SWNTs) and metal oxide nanobelts or nanowires, as a sensing medium bridging a pair of interdigitated electrodes (IDE) realized through a silicon-based microfabrication and micromachining technique. The DE fingers are fabricated on a silicon substrate using standard photolithography and thin film metallization techniques. It is noteworthy that the fabrication techniques employed are not confined to the silicon substrate. Through spin casting and careful substrate selection (i.e. clothing, glass, polymer, etc.), additional degrees of freedom can be exploited to enhance sensitivity or to conform to unique applications. Both in-situ growth of nanostructured materials and casting of nanostructured dispersions were used to produce analogous chemical sensing devices.

  5. Synthesis of highly dispersed platinum particles on carbon nanotubes by an in situ vapor-phase method

    Energy Technology Data Exchange (ETDEWEB)

    Mercado-Zúñiga, C. [Depto. Ing. Metalurgia y Materiales, Instituto Politecnico Nacional, Mexico 07300 D.F. (Mexico); Vargas-García, J.R., E-mail: rvargasga@ipn.mx [Depto. Ing. Metalurgia y Materiales, Instituto Politecnico Nacional, Mexico 07300 D.F. (Mexico); Hernández-Pérez, M.A. [Depto. Ing. Metalurgia y Materiales, Instituto Politecnico Nacional, Mexico 07300 D.F. (Mexico); Figueroa-Torres, M.Z. [Depto. Eco-Materiales y Energia, Univ. Autonoma de Nuevo Leon, Nuevo Leon 66450 (Mexico); Cervantes-Sodi, F. [Depto. Fisica y Matematicas, Univ. Iberoamericana, Mexico 01209 D.F. (Mexico); Torres-Martínez, L.M. [Depto. Eco-Materiales y Energia, Univ. Autonoma de Nuevo Leon, Nuevo Leon 66450 (Mexico)

    2014-12-05

    Highlights: • Highly dispersed Pt nanoparticles were prepared on functionalized carbon nanotubes. • A simple and competitive vapor-phase method was employed. • Carbonyl groups were assumed to be responsible for assisted decomposition of Pt-acac. • Pt particles were highly dispersed because carbonyl groups served as reaction sites. • Particles of 2.3 nm in size were highly dispersed even the high loading (27 wt%Pt). - Abstract: Highly dispersed Pt nanoparticles were prepared on functionalized multi-walled carbon nanotubes (f-MWCNTs) using a simple in situ vapor-phase method. The method consisted in two-step procedure in which an initial mixture of Pt precursor (Pt-acac) and f-MWCNTs was heated in a quartz tube reactor, first at 180 °C and then at 400 °C. Fourier transform infrared spectroscopy (FTIR–ATR), thermal gravimetric analysis (TGA) and X-ray diffraction (XRD) were used to follow the chemical and structural transformations of mixture components during heating steps. The functionalization of MWCNTs with HNO{sub 3}/H{sub 2}SO{sub 4} solution resulted in formation of surface carbonyl groups. The FTIR–ATR and XRD results indicated that individual Pt-acac withstood heating at 180 °C, whereas it was dissociated when heated in contact with f-MWCNTs at the same temperature. Thus, the functional carbonyl groups were found to be responsible for assisted decomposition of Pt-acac at 180 °C. Since carbonyl groups served as reaction sites for decomposition of Pt-acac, the resulting particles were highly and homogeneously dispersed on the surface of MWCNTs even the relatively high metallic loading of 27 wt%. TEM observations revealed that crystalline Pt particles exhibit narrow size distribution with a mean size of 2.3 nm.

  6. Synthesis of highly dispersed platinum particles on carbon nanotubes by an in situ vapor-phase method

    International Nuclear Information System (INIS)

    Mercado-Zúñiga, C.; Vargas-García, J.R.; Hernández-Pérez, M.A.; Figueroa-Torres, M.Z.; Cervantes-Sodi, F.; Torres-Martínez, L.M.

    2014-01-01

    Highlights: • Highly dispersed Pt nanoparticles were prepared on functionalized carbon nanotubes. • A simple and competitive vapor-phase method was employed. • Carbonyl groups were assumed to be responsible for assisted decomposition of Pt-acac. • Pt particles were highly dispersed because carbonyl groups served as reaction sites. • Particles of 2.3 nm in size were highly dispersed even the high loading (27 wt%Pt). - Abstract: Highly dispersed Pt nanoparticles were prepared on functionalized multi-walled carbon nanotubes (f-MWCNTs) using a simple in situ vapor-phase method. The method consisted in two-step procedure in which an initial mixture of Pt precursor (Pt-acac) and f-MWCNTs was heated in a quartz tube reactor, first at 180 °C and then at 400 °C. Fourier transform infrared spectroscopy (FTIR–ATR), thermal gravimetric analysis (TGA) and X-ray diffraction (XRD) were used to follow the chemical and structural transformations of mixture components during heating steps. The functionalization of MWCNTs with HNO 3 /H 2 SO 4 solution resulted in formation of surface carbonyl groups. The FTIR–ATR and XRD results indicated that individual Pt-acac withstood heating at 180 °C, whereas it was dissociated when heated in contact with f-MWCNTs at the same temperature. Thus, the functional carbonyl groups were found to be responsible for assisted decomposition of Pt-acac at 180 °C. Since carbonyl groups served as reaction sites for decomposition of Pt-acac, the resulting particles were highly and homogeneously dispersed on the surface of MWCNTs even the relatively high metallic loading of 27 wt%. TEM observations revealed that crystalline Pt particles exhibit narrow size distribution with a mean size of 2.3 nm

  7. Highly-sensitive and large-dynamic diffuse optical tomography system for breast tumor detection

    Science.gov (United States)

    Du, Wenwen; Zhang, Limin; Yin, Guoyan; Zhang, Yanqi; Zhao, Huijuan; Gao, Feng

    2018-02-01

    Diffuse optical tomography (DOT) as a new functional imaging has important clinical applications in many aspects such as benign and malignant breast tumor detection, tumor staging and so on. For quantitative detection of breast tumor, a three-wavelength continuous-wave DOT prototype system combined the ultra-high sensitivity of the photon-counting detection and the measurement parallelism of the lock-in technique was developed to provide high temporal resolution, high sensitivity, large dynamic detection range and signal-to-noise ratio. Additionally, a CT-analogous scanning mode was proposed to cost-effectively increase the detection data. To evaluate the feasibility of the system, a series of assessments were conducted. The results demonstrate that the system can obtain high linearity, stability and negligible inter-wavelength crosstalk. The preliminary phantom experiments show the absorption coefficient is able to be successfully reconstructed, indicating that the system is one of the ideal platforms for optical breast tumor detection.

  8. Confidentiality Enhancement of Highly Sensitive Nuclear Data Using Steganography with Chaotic Encryption over OFDM Channel

    International Nuclear Information System (INIS)

    Mahmoud, S.; Ayad, N.; Elsayed, F.; Elbendary, M.

    2016-01-01

    Full text: Due to the widespread usage of the internet and other wired and wireless communication methods, the security of the transmitted data has become a major requirement. Nuclear knowledge is mainly built upon the exchange of nuclear information which is considered highly sensitive information, so its security has to be enhanced by using high level security mechanisms. Data confidentiality is concerned with the achievement of higher protection for confidential information from unauthorized disclosure or access. Cryptography and steganography are famous and widely used techniques that process information in order to achieve its confidentiality, but sometimes, when used individually, they don’t satisfy a required level of security for highly sensitive data. In this paper, cryptography is accompanied with steganography for constituting a multilayer security techniques that can strengthen the level of security of highly confidential nuclear data that are archived or transmitted through different channel types and noise conditions. (author)

  9. Platinum Iron Intermetallic Nanoparticles Supported on Carbon Formed In Situ by High-Pressure Pyrolysis for Efficient Oxygen Reduction

    DEFF Research Database (Denmark)

    Hu, Yang; Jensen, Jens Oluf; Zhang, Wei

    2016-01-01

    Carbon-supported PtFe alloy catalysts are synthesized by the one-step, high-temperature pyrolysis of Pt, Fe, and C precursors. As a result of the high temperature, the formed PtFe nanoparticles possess highly ordered, face-centered tetragonal, intermetallic structures with a mean size of ≈11.8 nm....... At 0.9 V versus the reversible hydrogen electrode, the PtFe nanoparticles show a 6.8 times higher specific activity than the reference Pt/C catalyst towards the oxygen reduction reaction (ORR) as well as excellent stability, most likely because of the durable intermetallic structure and the preleaching...... treatment of the catalyst. During these preliminary syntheses, we found that a portion of the PtFe nanoparticles is buried in the in situ formed carbon phase, which limits Pt utilization in the catalyst and results in a mass-specific activity equivalent to the commercial Pt/C catalyst. Moreover...

  10. Processing of Bi-2212 and Nb$_3$Sn studied in situ by high energy synchrotron diffraction and micro-tomography

    CERN Document Server

    Kadar, Julian

    Next generation superconducting wires have been studied to obtain more information on the evolution of phase growth, crystallite size and strain state during wire processing. The high energy scattering beam line ID15 at the European Synchrotron Radiation Facility provides a very high flux of high energy photons for very fast in situ X-ray diffraction and micro-tomography studies of Bi-2212/Ag and Nb$_3$S/Cu wire samples. The typical wire processing conditions could be imitated in the X-ray transparent furnace at ID15 for diffraction and tomography studies. Efficient data analysis is mandatory in order to handle the very fast data acquisition rate. For this purpose an Excel-VBA based program was developed that allows a semi-automated fitting and tracking of peaks with pre-set constraints. With this method, more than one thousand diffraction patterns have been analysed to extract d-spacing, peak intensity and peak width values. X ray absorption micro tomograms were recorded simultaneously with the X-ray diffrac...

  11. In-situ synthesis of Co_3O_4/graphite nanocomposite for high-performance supercapacitor electrode applications

    International Nuclear Information System (INIS)

    M, Gopalakrishnan; G, Srikesh; A, Mohan; V, Arivazhagan

    2017-01-01

    Highlights: • High surface area, which governs the specific capacitance. • High chemical and thermal stability. • Co_3O_4/graphite nanocomposite electrode shows lower resistance. - Abstract: In this work, a low cost and pollution free in-situ synthesis of phase pure Co_3O_4 nanoparticles and Co_3O_4/graphite nanocomposite have been successfully developed via co-precipitation method followed by the thermal treatment process. The prepared samples were characterized by powder X-ray diffraction, scanning electron microscope, high resolution transmission electron microscope, Fourier Transform Infrared Spectroscopy and electrochemical measurements. Electrochemical measurements such as cyclic voltammetry, galvanostatic charge–discharge, electrochemical impedance spectroscopy were carried out in 6 M KOH aqueous electrolytic solution. The results show the excellent maximum specific capacitive behavior of 239.5 F g"−"1 for pure and 395.04 F g"−"1 for Co_3O_4/graphite nanocomposite at a current density of 0.5 A g"−"1. This composite exhibits a good cyclic stability, with a small loss of 2.68% of maximum capacitance over a consecutive 1000 cycles. The investigation indicates that the prepared electrode material could be a potential and promising candidate for electrochemical supercapacitors.

  12. High performance SONOS flash memory with in-situ silicon nanocrystals embedded in silicon nitride charge trapping layer

    Science.gov (United States)

    Lim, Jae-Gab; Yang, Seung-Dong; Yun, Ho-Jin; Jung, Jun-Kyo; Park, Jung-Hyun; Lim, Chan; Cho, Gyu-seok; Park, Seong-gye; Huh, Chul; Lee, Hi-Deok; Lee, Ga-Won

    2018-02-01

    In this paper, SONOS-type flash memory device with highly improved charge-trapping efficiency is suggested by using silicon nanocrystals (Si-NCs) embedded in silicon nitride (SiNX) charge trapping layer. The Si-NCs were in-situ grown by PECVD without additional post annealing process. The fabricated device shows high program/erase speed and retention property which is suitable for multi-level cell (MLC) application. Excellent performance and reliability for MLC are demonstrated with large memory window of ∼8.5 V and superior retention characteristics of 7% charge loss for 10 years. High resolution transmission electron microscopy image confirms the Si-NC formation and the size is around 1-2 nm which can be verified again in X-ray photoelectron spectroscopy (XPS) where pure Si bonds increase. Besides, XPS analysis implies that more nitrogen atoms make stable bonds at the regular lattice point. Photoluminescence spectra results also illustrate that Si-NCs formation in SiNx is an effective method to form deep trap states.

  13. High temperature in operando and in situ spectroscopy on electrified surfaces and interfaces

    DEFF Research Database (Denmark)

    Chatzichristodoulou, Christodoulos; Hansen, Karin Vels; Holtappels, Peter

    electrodes without contaminants have demanded a better insight into the electrode surface reactions and chemistries. Spectroscopic techniques can be applied to these cells but are still experimentally challenging due to the high temperature operation conditions. DTU Energy has in the recent years invested...

  14. In-situ high-P, T X-ray microtomographic imaging during large deformation

    DEFF Research Database (Denmark)

    Wang, Y; Lesher, Charles

    2011-01-01

    We have examined the microstructural evolution of a two-phase composite (olivine + Fe-Ni-S) during large shear deformation, using a newly developed high-pressure X-ray tomography microscope. Two samples were examined: a load-bearing framework–type texture, where the alloy phase (Fe-Ni-S) was pres...

  15. In situ X-ray diffraction environments for high-pressure reactions

    DEFF Research Database (Denmark)

    R. S. Hansen, Bjarne; Møller, Kasper Trans; Paskevicius, Mark

    2015-01-01

    ), quartz glass (SiO2), stainless steel (S316) and glassy carbon (Sigradur K), and burst pressures are calculated and tested for the different tube materials. In these studies, high hydrogen pressure is generated with a metal hydride hydrogen compressor mounted in a closed system, which allows reuse...

  16. Coalescence aspects of cobalt nanoparticles during in situ high-temperature annealing

    NARCIS (Netherlands)

    Palasantzas, G; Vystavel, T; Koch, SA; De Hosson, JTM

    2006-01-01

    In this work we investigate the coalescence aspects of Co nanoparticles. It was observed that nanoparticles in contact with the substrate are relatively immobile, whereas those on top of other Co particles can rearrange themselves during high-temperature annealing and further coalesce. Indeed,

  17. Sensitivity of MENA Tropical Rainbelt to Dust Shortwave Absorption: A High Resolution AGCM Experiment

    KAUST Repository

    Bangalath, Hamza Kunhu

    2016-06-13

    Shortwave absorption is one of the most important, but the most uncertain, components of direct radiative effect by mineral dust. It has a broad range of estimates from different observational and modeling studies and there is no consensus on the strength of absorption. To elucidate the sensitivity of the Middle East and North Africa (MENA) tropical summer rainbelt to a plausible range of uncertainty in dust shortwave absorption, AMIP-style global high resolution (25 km) simulations are conducted with and without dust, using the High-Resolution Atmospheric Model (HiRAM). Simulations with dust comprise three different cases by assuming dust as a very efficient, standard and inefficient absorber. Inter-comparison of these simulations shows that the response of the MENA tropical rainbelt is extremely sensitive to the strength of shortwave absorption. Further analyses reveal that the sensitivity of the rainbelt stems from the sensitivity of the multi-scale circulations that define the rainbelt. The maximum response and sensitivity are predicted over the northern edge of the rainbelt, geographically over Sahel. The sensitivity of the responses over the Sahel, especially that of precipitation, is comparable to the mean state. Locally, the response in precipitation reaches up to 50% of the mean, while dust is assumed to be a very efficient absorber. Taking into account that Sahel has a very high climate variability and is extremely vulnerable to changes in precipitation, the present study suggests the importance of reducing uncertainty in dust shortwave absorption for a better simulation and interpretation of the Sahel climate.

  18. Sensitivity of MENA Tropical Rainbelt to Dust Shortwave Absorption: A High Resolution AGCM Experiment

    KAUST Repository

    Bangalath, Hamza Kunhu; Stenchikov, Georgiy L.

    2016-01-01

    Shortwave absorption is one of the most important, but the most uncertain, components of direct radiative effect by mineral dust. It has a broad range of estimates from different observational and modeling studies and there is no consensus on the strength of absorption. To elucidate the sensitivity of the Middle East and North Africa (MENA) tropical summer rainbelt to a plausible range of uncertainty in dust shortwave absorption, AMIP-style global high resolution (25 km) simulations are conducted with and without dust, using the High-Resolution Atmospheric Model (HiRAM). Simulations with dust comprise three different cases by assuming dust as a very efficient, standard and inefficient absorber. Inter-comparison of these simulations shows that the response of the MENA tropical rainbelt is extremely sensitive to the strength of shortwave absorption. Further analyses reveal that the sensitivity of the rainbelt stems from the sensitivity of the multi-scale circulations that define the rainbelt. The maximum response and sensitivity are predicted over the northern edge of the rainbelt, geographically over Sahel. The sensitivity of the responses over the Sahel, especially that of precipitation, is comparable to the mean state. Locally, the response in precipitation reaches up to 50% of the mean, while dust is assumed to be a very efficient absorber. Taking into account that Sahel has a very high climate variability and is extremely vulnerable to changes in precipitation, the present study suggests the importance of reducing uncertainty in dust shortwave absorption for a better simulation and interpretation of the Sahel climate.

  19. 12th Rencontres du Vietnam : High Sensitivity Experiments Beyond the Standard Model

    CERN Document Server

    2016-01-01

    The goal of this workshop is to gather researchers, theoreticians, experimentalists and young scientists searching for physics beyond the Standard Model of particle physics using high sensitivity experiments. The standard model has been very successful in describing the particle physics world; the Higgs-Englert-Brout boson discovery is its last major discovery. Complementary to the high energy frontier explored at colliders, real opportunities for discovery exist at the precision frontier, testing fundamental symmetries and tracking small SM deviations.

  20. Highly sensitive electrochemical determination of 1-naphthol based on high-index facet SnO2 modified electrode

    International Nuclear Information System (INIS)

    Huang Xiaofeng; Zhao Guohua; Liu Meichuan; Li Fengting; Qiao Junlian; Zhao Sichen

    2012-01-01

    Highlights: ► It is the first time to employ high-index faceted SnO 2 in electrochemical analysis. ► High-index faceted SnO 2 has excellent electrochemical activity toward 1-naphthol. ► Highly sensitive determination of 1-naphthol is realized on high-index faceted SnO 2 . ► The detection limit of 1-naphthol is as low as 5 nM on high-index faceted SnO 2 . ► Electro-oxidation kinetics for 1-napthol on the novel electrode is discussed. - Abstract: SnO 2 nanooctahedron with {2 2 1} high-index facet (HIF) was synthesized by a simple hydrothermal method, and was firstly employed to sensitive electrochemical sensing of a typical organic pollutant, 1-naphthol (1-NAP). The constructed HIF SnO 2 modified glassy carbon electrode (HIF SnO 2 /GCE) possessed advantages of large effective electrode area, high electron transfer rate, and low charge transfer resistance. These improved electrochemical properties allowed the high electrocatalytic performance, high effective active sites and high adsorption capacity of 1-NAP on HIF SnO 2 /GCE. Cyclic voltammetry (CV) results showed that the electrochemical oxidation of 1-NAP obeyed a two-electron transfer process and the electrode reaction was under diffusion control on HIF SnO 2 /GCE. By adopting differential pulse voltammetry (DPV), electrochemical detection of 1-NAP was conducted on HIF SnO 2 /GCE with a limit of detection as low as 5 nM, which was relatively low compared to the literatures. The electrode also illustrated good stability in comparison with those reported value. Satisfactory results were obtained with average recoveries in the range of 99.7–103.6% in the real water sample detection. A promising device for the electrochemical detection of 1-NAP with high sensitivity has therefore been provided.