A=225 implantation for $^{221}$Fr source for TRIUMF atom trap

CERN Multimedia

The FrPNC Collaboration is mounting an atom trap for parity violation experiments and precision spectroscopy on francium atoms at TRIUMF's ISAC facility. We would like to use ISOLDE's capability of simultaneously implanting A=225 (while another experiment runs online) to make a long-lived source feeding $^{221}$Fr for tests of the trap. $^{225}$Ra $\\beta$-decays to $^{225}$Ac, which then $\\alpha$-decays, producing 100 keV $^{221}$Fr t$_{1/2}$= 4.8 minute recoils. The implanted A=225 source would be shipped to TRIUMF, where it would be held for several minutes at a time a few mm from the same yttrium foil that normally receives the ISAC beam. SRIM calculations imply that 20% of the $^{221}$Fr will be implanted in a 1 cm diameter spot on the yttrium. Then the yttrium foil is moved to the trap and heated to release the Fr atoms, just as in normal ISAC online operation. A test implantation will be done at 10$^{7}$/sec production for 1 day, testing whether carbon cracking on the implantation foil in the mass separ...

Optimizing labelling conditions of 213Bi-DOTATATE for preclinical applications of peptide receptor targeted alpha therapy.

Science.gov (United States)

Chan, Ho Sze; de Blois, Erik; Konijnenberg, Mark W; Morgenstern, Alfred; Bruchertseifer, Frank; Norenberg, Jeffrey P; Verzijlbergen, Fred J; de Jong, Marion; Breeman, Wouter A P

2017-01-01

213 Bismuth ( 213 Bi, T 1/2 = 45.6 min) is one of the most frequently used α-emitters in cancer research. High specific activity radioligands are required for peptide receptor radionuclide therapy. The use of generators containing less than 222 MBq 225 Ac (actinium), due to limited availability and the high cost to produce large-scale 225 Ac/ 213 Bi generators, might complicate in vitro and in vivo applications though.Here we present optimized labelling conditions of a DOTA-peptide with an 225 Ac/ 213 Bi generator (< 222 MBq) for preclinical applications using DOTA-Tyr 3 -octreotate (DOTATATE), a somatostatin analogue. The following labelling conditions of DOTATATE with 213 Bi were investigated; peptide mass was varied from 1.7 to 7.0 nmol, concentration of TRIS buffer from 0.15 mol.L -1 to 0.34 mol.L -1 , and ascorbic acid from 0 to 71 mmol.L -1 in 800 μL. All reactions were performed at 95 °C for 5 min. After incubation, DTPA (50 nmol) was added to stop the labelling reaction. Besides optimizing the labelling conditions, incorporation yield was determined by ITLC-SG and radiochemical purity (RCP) was monitored by RP-HPLC up to 120 min after labelling. Dosimetry studies in the reaction vial were performed using Monte Carlo and in vitro clonogenic assay was performed with a rat pancreatic tumour cell line, CA20948. At least 3.5 nmol DOTATATE was required to obtain incorporation ≥ 99 % with 100 MBq 213 Bi (at optimized pH conditions, pH 8.3 with 0.15 mol.L -1 TRIS) in a reaction volume of 800 μL. The cumulative absorbed dose in the reaction vial was 230 Gy/100 MBq in 30 min. A minimal final concentration of 0.9 mmol.L -1 ascorbic acid was required for ~100 MBq (t = 0) to minimize radiation damage of DOTATATE. The osmolarity was decreased to 0.45 Osmol/L.Under optimized labelling conditions, 213 Bi-DOTATATE remained stable up to 2 h after labelling, RCP was ≥ 85 %. In vitro showed a negative correlation between ascorbic acid

Indentation analysis of nano-particle using nano-contact mechanics models during nano-manipulation based on atomic force microscopy

International Nuclear Information System (INIS)

Daeinabi, Khadijeh; Korayem, Moharam Habibnejad

2011-01-01

Atomic force microscopy is applied to measure intermolecular forces and mechanical properties of materials, nano-particle manipulation, surface scanning and imaging with atomic accuracy in the nano-world. During nano-manipulation process, contact forces cause indentation in contact area between nano-particle and tip/substrate which is considerable at nano-scale and affects the nano-manipulation process. Several nano-contact mechanics models such as Hertz, Derjaguin–Muller–Toporov (DMT), Johnson–Kendall–Roberts–Sperling (JKRS), Burnham–Colton–Pollock (BCP), Maugis–Dugdale (MD), Carpick–Ogletree–Salmeron (COS), Pietrement–Troyon (PT), and Sun et al. have been applied as the continuum mechanics approaches at nano-scale. In this article, indentation depth and contact radius between tip and substrate with nano-particle for both spherical and conical tip shape during nano-manipulation process are analyzed and compared by applying theoretical, semiempirical, and empirical nano-contact mechanics models. The effects of adhesion force, as the main contrast point in different nano-contact mechanics models, on nano-manipulation analysis is investigated for different contact radius, and the critical point is discussed for mentioned models.

The sorption of polonium, actinium and protactinium onto geological materials

International Nuclear Information System (INIS)

Baston, G.M.N.; Berry, J.A.; Brownsword, M.; Heath, T.G.; Ilett, D.J.; McCrohon, R.; Tweed, C.J.; Yui, M.

1999-01-01

This paper describes a combined experimental and modeling program of generic sorption studies to increase confidence in the performance assessment for a potential high-level radioactive waste repository in Japan. The sorption of polonium, actinium and protactinium onto geological materials has been investigated. Sorption of these radioelements onto bentonite, tuff and granodiorite from equilibrated de-ionized water was studied under reducing conditions at room temperature. In addition, the sorption of actinium and protactinium was investigated at 60 C. Thermodynamic chemical modeling was carried out to aid interpretation of the results

The sorption of polonium, actinium and protactinium onto geological materials

Energy Technology Data Exchange (ETDEWEB)

Baston, G.M.N.; Berry, J.A.; Brownsword, M.; Heath, T.G.; Ilett, D.J.; McCrohon, R.; Tweed, C.J.; Yui, M.

1999-07-01

This paper describes a combined experimental and modeling program of generic sorption studies to increase confidence in the performance assessment for a potential high-level radioactive waste repository in Japan. The sorption of polonium, actinium and protactinium onto geological materials has been investigated. Sorption of these radioelements onto bentonite, tuff and granodiorite from equilibrated de-ionized water was studied under reducing conditions at room temperature. In addition, the sorption of actinium and protactinium was investigated at 60 C. Thermodynamic chemical modeling was carried out to aid interpretation of the results.

20 CFR 627.225 - Employment generating activities.

Science.gov (United States)

2010-04-01

... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false Employment generating activities. 627.225 Section 627.225 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR GENERAL... chambers of commerce); JTPA staff participation on economic development boards and commissions, and work...

Ac, La, and Ce radioimpurities in {sup 225}Ac produced in 40-200 MeV proton irradiations of thorium

Energy Technology Data Exchange (ETDEWEB)

Engle, Jonathan W.; Ballard, Beau D. [Los Alamos National Laboratory, NM (United States); Weidner, John W. [Air Force Institute of Technology, Wright Patterson Air Force Base, OH (United States); and others

2014-10-01

Accelerator production of {sup 225}Ac addresses the global supply deficiency currently inhibiting clinical trials from establishing {sup 225}Ac's therapeutic utility, provided that the accelerator product is of sufficient radionuclidic purity for patient use. Two proton activation experiments utilizing the stacked foil technique between 40 and 200 MeV were employed to study the likely co-formation of radionuclides expected to be especially challenging to separate from {sup 225}Ac. Foils were assayed by nondestructive γ-spectroscopy and by α-spectroscopy of chemically processed target material. Nuclear formation cross sections for the radionuclides {sup 226}Ac and {sup 227}Ac as well as lower lanthanide radioisotopes {sup 139}Ce, {sup 141}Ce, {sup 143}Ce, and {sup 140}La whose elemental ionic radii closely match that of actinium were measured and are reported. The predictions of the latest MCNP6 event generators are compared with measured data, as they permit estimation of the formation rates of other radionuclides whose decay emissions are not clearly discerned in the complex spectra collected from {sup 232}Th(p,x) fission product mixtures. (orig.)

Gold surface supported spherical liposome-gold nano-particle nano-composite for label free DNA sensing.

Science.gov (United States)

Bhuvana, M; Narayanan, J Shankara; Dharuman, V; Teng, W; Hahn, J H; Jayakumar, K

2013-03-15

Immobilization of 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE) liposome-gold nano-particle (DOPE-AuNP) nano-composite covalently on 3-mercaptopropionic acid (MPA) on gold surface is demonstrated for the first time for electrochemical label free DNA sensing. Spherical nature of the DOPE on the MPA monolayer is confirmed by the appearance of sigmoidal voltammetric profile, characteristic behavior of linear diffusion, for the MPA-DOPE in presence of [Fe(CN)(6)](3-/4-) and [Ru(NH(3))(6)](3+) redox probes. The DOPE liposome vesicle fusion is prevented by electroless deposition of AuNP on the hydrophilic amine head groups of the DOPE. Immobilization of single stranded DNA (ssDNA) is made via simple gold-thiol linkage for DNA hybridization sensing in the presence of [Fe(CN)(6)](3-/4-). The sensor discriminates the hybridized (complementary target hybridized), un-hybridized (non-complementary target hybridized) and single base mismatch target hybridized surfaces sensitively and selectively without signal amplification. The lowest target DNA concentration detected is 0.1×10(-12)M. Cyclic voltammetry (CV), electrochemical impedance (EIS), differential pulse voltammetry (DPV) and quartz crystal microbalance (QCM) techniques are used for DNA sensing on DOPE-AuNP nano-composite. Transmission Electron Microscopy (TEM), Fourier Transform Infrared Spectroscopy (FTIR), Atomic Force Microscopy (AFM), Dynamic Light Scattering (DLS) and Ultraviolet-Visible (UV) spectroscopic techniques are used to understand the interactions between the DOPE, AuNP and ssDNA. The results indicate the presence of an intact and well defined spherical DOPE-AuNP nano-composite on the gold surface. The method could be applied for fabrication of the surface based liposome-AuNP-DNA composite for cell transfection studies at reduced reagents and costs. Copyright © 2012 Elsevier B.V. All rights reserved.

A Fabrication Technique for Nano-gap Electrodes by Atomic Force Microscopy Nano lithography

International Nuclear Information System (INIS)

Jalal Rouhi; Shahrom Mahmud; Hutagalung, S.D.; Kakooei, S.

2011-01-01

A simple technique is introduced for fabrication of nano-gap electrodes by using nano-oxidation atomic force microscopy (AFM) lithography with a Cr/ Pt coated silicon tip. AFM local anodic oxidation was performed on silicon-on-insulator (SOI) surfaces by optimization of desired conditions to control process in contact mode. Silicon electrodes with gaps of sub 31 nm were fabricated by nano-oxidation method. This technique which is simple, controllable, inexpensive and fast is capable of fabricating nano-gap structures. The current-voltage measurements (I-V) of the electrodes demonstrated very good insulating characteristics. The results show that silicon electrodes have a great potential for fabrication of single molecule transistors (SMT), single electron transistors (SET) and the other nano electronic devices. (author)

Gold nano particle decorated graphene core first generation PAMAM dendrimer for label free electrochemical DNA hybridization sensing.

Science.gov (United States)

Jayakumar, K; Rajesh, R; Dharuman, V; Venkatasan, R; Hahn, J H; Pandian, S Karutha

2012-01-15

A novel first generation (G1) poly(amidoamine) dendrimer (PAMAM) with graphene core (GG1PAMAM) was synthesized for the first time. Single layer of GG1PAMAM was immobilized covalently on mercaptopropionic acid (MPA) monolayer on Au transducer. This allows cost effective and easy deposition of single layer graphene on the Au transducer surface than the advanced vacuum techniques used in the literature. Au nano particles (17.5 nm) then decorated the GG1PAMAM and used for electrochemical DNA hybridization sensing. The sensor discriminates selectively and sensitively the complementary double stranded DNA (dsDNA, hybridized), non-complementary DNA (ssDNA, un-hybridized) and single nucleotide polymorphism (SNP) surfaces. Interactions of the MPA, GG1PAMAM and the Au nano particles were characterized by Ultra Violet (UV), Fourier Transform Infrared (FTIR), Raman spectroscopy (RS), Thermo gravimetric analysis (TGA), Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM), Cyclic Voltmetric (CV), Impedance spectroscopy (IS) and Differntial Pulse Voltammetry (DPV) techniques. The sensor showed linear range 1×10(-6) to 1×10(-12) M with lowest detection limit 1 pM which is 1000 times lower than G1PAMAM without graphene core. Copyright © 2011 Elsevier B.V. All rights reserved.

Purification of radium-226 for the manufacturing of actinium-225 in a cyclotron for alpha-immunotherapy; Radium-Aufreinigung zur Herstellung von Actinium-225 am Zyklotron fuer die Alpha-Immuntherapie

Energy Technology Data Exchange (ETDEWEB)

Marx, Sebastian Markus

2014-09-23

The thesis describes the development of methods for the purification of Ra-226. The objective was to obtain the radionuclide in the quality that is needed to be used as starting material in the manufacturing process for Ac-225 via proton-irradiated Ra-226. The radionuclide has been gained efficiently out of huge excesses of impurities. The high purity of the obtained radium affords its use as staring material in a pharmaceutical manufacturing process.

Immunogold labels: cell-surface markers in atomic force microscopy

NARCIS (Netherlands)

Putman, Constant A.J.; Putman, C.A.J.; de Grooth, B.G.; Hansma, Paul K.; van Hulst, N.F.; Greve, Jan

1993-01-01

The feasibility of using immunogold labels as cell-surface markers in atomic force microscopy is shown in this paper. The atomic force microscope (AFM) was used to image the surface of immunogold-labeled human lymphocytes. The lymphocytes were isolated from whole blood and labeled by an indirect

Labelling of macromoleculear carbohydrates by means of 'Hot Atom' reactions

International Nuclear Information System (INIS)

Lundqvist, H.; Malmborg, P.

1976-01-01

Radioactive labelling of polysaccharides have been performed using atoms with such high kinetic energy that they can break normally very stable bindings thus permitting labelling by substitution reactions. Such atoms can be produced in nuclear transformations. We have chosen to study the labelling efficiency of 'hot atoms' ( 77 Br, 123 I and 125 I) produced in radioactive decay (β + -decay and E.C.) of noble gas nuclides ( 77 Kr, 123 Xe and 125 Xe) which easily could be brought in close contact with the molecule to be labelled. Substances to be labelled have been starch particles and high molecular weight glycogen. (author)

Photocatalytic hydrogen generation from water under visible light using core/shell nano-catalysts.

Science.gov (United States)

Wang, X; Shih, K; Li, X Y

2010-01-01

A microemulsion technique was employed to synthesize nano-sized photocatalysts with a core (CdS)/shell (ZnS) structure. The primary particles of the photocatalysts were around 10 nm, and the mean size of the catalyst clusters in water was about 100 nm. The band gaps of the catalysts ranged from 2.25 to 2.46 eV. The experiments of photocatalytic H(2) generation showed that the catalysts (CdS)(x)/(ZnS)(1-x) with x ranging from 0.1 to 1 were able to produce hydrogen from water photolysis under visible light. The catalyst with x=0.9 had the highest rate of hydrogen production. The catalyst loading density also influenced the photo-hydrogen production rate, and the best catalyst concentration in water was 1 g L(-1). The stability of the nano-catalysts in terms of size, morphology and activity was satisfactory during an extended test period for a specific hydrogen production rate of 2.38 mmol g(-1) L(-1) h(-1) and a quantum yield of 16.1% under visible light (165 W Xe lamp, lambda>420 nm). The results demonstrate that the (CdS)/(ZnS) core/shell nano-particles are a novel photo-catalyst for renewable hydrogen generation from water under visible light. This is attributable to the large band-gap ZnS shell that separates the electron/hole pairs generated by the CdS core and hence reduces their recombinations.

Therapeutic efficacy and toxicity of {sup 225}Ac-labelled vs. {sup 213}Bi-labelled tumour-homing peptides in a preclinical mouse model of peritoneal carcinomatosis

Energy Technology Data Exchange (ETDEWEB)

Essler, Markus; Gaertner, Florian C.; Blechert, Birgit; Senekowitsch-Schmidtke, Reingard; Seidl, Christof [Technische Universitaet Muenchen, Department of Nuclear Medicine, Munich (Germany); Neff, Frauke [Helmholtz Zentrum Muenchen, Institute of Pathology, Neuherberg (Germany); Bruchertseifer, Frank; Morgenstern, Alfred [Institute for Transuranium Elements, European Commission, Joint Research Centre, Karlsruhe (Germany)

2012-04-15

Targeted delivery of alpha-particle-emitting radionuclides is a promising novel option in cancer therapy. We generated stable conjugates of the vascular tumour-homing peptide F3 both with {sup 225}Ac and {sup 213}Bi that specifically bind to nucleolin on the surface of proliferating tumour cells. The aim of our study was to determine the therapeutic efficacy of {sup 225}Ac-DOTA-F3 in comparison with that of {sup 213}Bi-DTPA-F3. ID{sub 50} values of {sup 213}Bi-DTPA-F3 and {sup 225}Ac-DOTA-F3 were determined via clonogenic assays. The therapeutic efficacy of both constructs was assayed by repeated treatment of mice bearing intraperitoneal MDA-MB-435 xenograft tumours. Therapy was monitored by bioluminescence imaging. Nephrotoxic effects were analysed by histology. ID{sub 50} values of {sup 213}Bi-DTPA-F3 and {sup 225}Ac-DOTA-F3 were 53 kBq/ml and 67 Bq/ml, respectively. The median survival of control mice treated with phosphate-buffered saline was 60 days after intraperitoneal inoculation of 1 x 10{sup 7} MDA-MB-435 cells. Therapy with 6 x 1.85 kBq of {sup 225}Ac-DOTA-F3 or 6 x 1.85 MBq of {sup 213}Bi-DTPA-F3 prolonged median survival to 95 days and 97 days, respectively. While F3 labelled with short-lived {sup 213}Bi (t{sub 1/2} 46 min) reduced the tumour mass at early time-points up to 30 days after treatment, the antitumour effect of {sup 225}Ac-DOTA-F3 (t{sub 1/2} 10 days) increased at later time-points. The difference in the fraction of necrotic cells after treatment with {sup 225}Ac-DOTA-F3 (43%) and with {sup 213}Bi-DTPA-F3 (36%) was not significant. Though histological analysis of kidney samples revealed acute tubular necrosis and tubular oedema in 10-30% of animals after treatment with {sup 225}Ac-DOTA-F3 or {sup 213}Bi-DTPA-F3, protein casts were negligible (2%), indicating only minor damage to the kidney. Therapy with both {sup 225}Ac-DOTA-F3 and {sup 213}Bi-DTPA-F3 increased survival of mice with peritoneal carcinomatosis. Mild renal toxicity of both

Development of a nano-zirconia based {sup 68}Ge/{sup 68}Ga generator for biomedical applications

Energy Technology Data Exchange (ETDEWEB)

Chakravarty, Rubel [Radiopharmaceuticals Division, Bhabha Atomic Research Centre, Mumbai-400085 (India); Shukla, Rakesh [Chemistry Division, Bhabha Atomic Research Centre, Mumbai-400085 (India); Ram, Ramu [Radiopharmaceuticals Division, Bhabha Atomic Research Centre, Mumbai-400085 (India); Tyagi, Avesh Kumar [Chemistry Division, Bhabha Atomic Research Centre, Mumbai-400085 (India); Dash, Ashutosh, E-mail: adash@barc.gov.i [Radiopharmaceuticals Division, Bhabha Atomic Research Centre, Mumbai-400085 (India); Venkatesh, Meera [Radiopharmaceuticals Division, Bhabha Atomic Research Centre, Mumbai-400085 (India)

2011-05-15

Introduction: Most of the commercially available {sup 68}Ge/{sup 68}Ga generator systems are not optimally designed for direct applications in a clinical context. We have developed a nano-zirconia based {sup 68}Ge/{sup 68}Ga generator system for accessing {sup 68}Ga amenable for the preparation of radiopharmaceuticals. Methods: Nano-zirconia was synthesized by the in situ reaction of zirconyl chloride with ammonium hydroxide in alkaline medium. The physical characteristics of the material were studied by various analytical techniques. A 740 MBq (20 mCi) {sup 68}Ge/{sup 68}Ga generator was developed using this sorbent and its performance was evaluated for a period of 1 year. The suitability of {sup 68}Ga for labeling biomolecules was ascertained by labeling DOTA-TATE with {sup 68}Ga. Results: The material synthesized was nanocrystalline with average particle size of {approx}7 nm, pore-size of {approx}4 A and a high surface area of 340{+-}10 m{sup 2} g{sup -1}. {sup 68}Ga could be regularly eluted from this generator in 0.01N HCl medium with an overall radiochemical yield >80% and with high radionuclidic (<10{sup -5}% of {sup 68}Ge impurity) and chemical purity (<0.1 ppm of Zr, Fe and Mn ions). The compatibility of the product for preparation of {sup 68}Ga-labeled DOTA-TATE under the optimized reaction conditions was found to be satisfactory in terms of high labeling yields (>99%). The generator gave a consistent performance with respect to the elution yield and purity of {sup 68}Ga over a period of 1 year. Conclusions: The feasibility of preparing an efficient {sup 68}Ge/{sup 68}Ga generator which can directly be used for biomedical applications has been demonstrated.

Use of labelled atoms in thermal analysis

International Nuclear Information System (INIS)

Balek, V.; Beckman, I.N.

1985-01-01

The article informs of the preparation of labelled samples for which the most frequently used radionuclides are 14 C, 3 H or 2 H, 32 P, 35 S and others as well as radioactive gases such as 85 Kr, 133 Xe or 220 Rn and 222 Rn. The equipment is described for the application of labelled atoms in thermal analysis consisting of a detector for measuring radioactivity and a system for measuring thermal analysis parameters. Examples are given of the use of labelled atoms in the study of chemical reactions of solids, in autoradiography or in Moessbauer spectroscopy. The greatest attention is devoted to the use of labelled atoms in emanation thermal analysis. By this technique it is possible to study chemical reactions and phase transformations, to continuously monitor changes in the surface and morphology of dispersion substances, to characterize the mobility of defects in the structure of solids and the active state of the structure of solids and to ascertain mechanical, radiation and chemical effects on solids. Attention is also devoted to the technological applications of emanation thermal analysis (the solidification of cement paste, calcination and the firing of the mixture of oxides for the manufacture of ferrites). (E.S.)

Silicon Nano fabrication by Atomic Force Microscopy-Based Mechanical Processing

International Nuclear Information System (INIS)

Miyake, Sh.; Wang, M.; Kim, J.

2014-01-01

This paper reviews silicon nano fabrication processes using atomic force microscopy (AFM). In particular, it summarizes recent results obtained in our research group regarding AFM-based silicon nano fabrication through mechanochemical local oxidation by diamond tip sliding, as well as mechanical, electrical, and electromechanical processing using an electrically conductive diamond tip. Microscopic three-dimensional manufacturing mainly relies on etching, deposition, and lithography. Therefore, a special emphasis was placed on nano mechanical processes, mechanochemical reaction by potassium hydroxide solution etching, and mechanical and electrical approaches. Several important surface characterization techniques consisting of scanning tunneling microscopy and related techniques, such as scanning probe microscopy and AFM, were also discussed.

Nano Electronics on Atomically Controlled van der Waals Quantum Heterostructures

Science.gov (United States)

2018-02-19

AFRL-AFOSR-JP-TR-2018-0012 Nano Electronics on Atomically Controlled van der Waals Quantum Heterostructures PHILIP Kim HARVARD COLLEGE PRESIDENT...21-02-2018 2.  REPORT TYPE      Final 3.  DATES COVERED (From - To)      15 Aug 2015 to 14 Feb 2017 4.  TITLE AND SUBTITLE Nano Electronics on...NOTES 14.  ABSTRACT We report molecular beam epitaxial growth and electronic transport properties of high quality topological insulator Bi2Se3 thin films

The nano-science of C sub 6 0 molecule

CERN Document Server

Rafii-Tabar, H

2002-01-01

Over the past few years, nano-science and its associated nano-technology have emerged into prominence in research institutions across the world. They have brought about new scientific and engineering paradigms, allowing for the manipulation of single atoms and molecules, designing and fabricating new materials, atom-by-atom, and devices that operate on significantly reduced time and length scales. One important area of research in nano-science and nano technology is carbon-based physics in the form of fullerene physics. The C sub 6 0 molecule, and other cage-like fullerenes, together with carbon nano tubes provide objects that can be combined to generate three-dimensional functional structures for use in the anticipated nano-technology of future. The unique properties of C sub 6 0 can also be exploited in designing nano-phase thin films with applications in nano-scope device technology and processes such as nano-lithography. This requires a deep understanding of the highly complex process of adsorption of thi...

Interfacial engineering of two-dimensional nano-structured materials by atomic layer deposition

Energy Technology Data Exchange (ETDEWEB)

Zhuiykov, Serge, E-mail: serge.zhuiykov@ugent.be [Ghent University Global Campus, Department of Applied Analytical & Physical Chemistry, Faculty of Bioscience Engineering, 119 Songdomunhwa-ro, Yeonsu-Gu, Incheon 406-840 (Korea, Republic of); Kawaguchi, Toshikazu [Global Station for Food, Land and Water Resources, Global Institution for Collaborative Research and Education, Hokkaido University, N10W5 Kita-ku, Sapporo, Hokkaido 060-0810 (Japan); Graduate School of Environmental Science, Hokkaido University, N10W5 Kita-ku, Sapporo, Hokkaido 060-0810 (Japan); Hai, Zhenyin; Karbalaei Akbari, Mohammad; Heynderickx, Philippe M. [Ghent University Global Campus, Department of Applied Analytical & Physical Chemistry, Faculty of Bioscience Engineering, 119 Songdomunhwa-ro, Yeonsu-Gu, Incheon 406-840 (Korea, Republic of)

2017-01-15

Highlights: • Advantages of atomic layer deposition technology (ALD) for two-dimensional nano-crystals. • Conformation of ALD technique and chemistry of precursors. • ALD of semiconductor oxide thin films. • Ultra-thin (∼1.47 nm thick) ALD-developed tungsten oxide nano-crystals on large area. - Abstract: Atomic Layer Deposition (ALD) is an enabling technology which provides coating and material features with significant advantages compared to other existing techniques for depositing precise nanometer-thin two-dimensional (2D) nanostructures. It is a cyclic process which relies on sequential self-terminating reactions between gas phase precursor molecules and a solid surface. ALD is especially advantageous when the film quality or thickness is critical, offering ultra-high aspect ratios. ALD provides digital thickness control to the atomic level by depositing film one atomic layer at a time, as well as pinhole-free films even over a very large and complex areas. Digital control extends to sandwiches, hetero-structures, nano-laminates, metal oxides, graded index layers and doping, and it is perfect for conformal coating and challenging 2D electrodes for various functional devices. The technique’s capabilities are presented on the example of ALD-developed ultra-thin 2D tungsten oxide (WO{sub 3}) over the large area of standard 4” Si substrates. The discussed advantages of ALD enable and endorse the employment of this technique for the development of hetero-nanostructure 2D semiconductors with unique properties.

Nano-dot and nano-pit fabrication on a GaAs substrate by a pulse applied AFM

International Nuclear Information System (INIS)

Kim, H C; Yu, J S; Ryu, S H

2012-01-01

The nano-patterning characteristics of GaAs is investigated using a pulse applied atomic force microscope (AFM). Very short range voltage pulses of micro to nano-seconds’ duration are applied to a conductive diamond-coated silicon (Si) tip in contact mode, to regulate the created feature size. The effects of pulse conditions such as pulse voltage, duration, frequency, offset voltage, anodization time, and applied tip pressure on nano-dot generation are characterized, based on the experiments. An interesting phenomenon, nano-pit creation instead of nano-dot creation, is observed when the applied pulse duration is less than 100 μs. Pulse frequency and offset voltage are also involved in nano-pit generation. The electrical spark discharge between the tip and the GaAs's surface is the most probable cause of the nano-pit creation and its generation mechanism is explained by considering the relevant pulse parameters. Nano-pits over 15 nm in depth are acquired on the GaAs substrate by adjusting the pulse conditions. This research facilitates the fabrication of more complex nano-structures on semiconductor materials since nano-dots and nano-pits could be easily made without any additional post-processes. (paper)

Amides with nitrogenous heterocyclic substituent, their manufacturing process and their use to draw out selectively Actinium series (III) and to separate them in particular from Lanthanides (III)

International Nuclear Information System (INIS)

Cuillerdier, C.; Musikas, C.

1993-01-01

Present invention is concerned with new amides with nitrogenous heterocyclic substituent utilizable to separate trivalent actinium series from trivalent lanthanides. In these molecules, it is possible to obtain particularly covalent liaison which has more affinity with 5f series, that is to say actinium series; included a manufacturing process for these amides with nitrogenous heterocyclic substituent

The nano-science of C60 molecule

International Nuclear Information System (INIS)

Rafii-Tabar, H.

2002-01-01

Over the past few years, nano-science and its associated nano-technology have emerged into prominence in research institutions across the world. They have brought about new scientific and engineering paradigms, allowing for the manipulation of single atoms and molecules, designing and fabricating new materials, atom-by-atom, and devices that operate on significantly reduced time and length scales. One important area of research in nano-science and nano technology is carbon-based physics in the form of fullerene physics. The C 6 0 molecule, and other cage-like fullerenes, together with carbon nano tubes provide objects that can be combined to generate three-dimensional functional structures for use in the anticipated nano-technology of future. The unique properties of C 6 0 can also be exploited in designing nano-phase thin films with applications in nano-scope device technology and processes such as nano-lithography. This requires a deep understanding of the highly complex process of adsorption of this molecule on a variety of substrates. We review the field of nano-scale nucleation and growth of C 6 0 molecules on some of the technologically important substrates. In addition to experimental results, the results of a set of highly accurate computational simulations are also reported

212Pb-Labeled Antibody 225.28 Targeted to Chondroitin Sulfate Proteoglycan 4 for Triple-Negative Breast Cancer Therapy in Mouse Models

Directory of Open Access Journals (Sweden)

Benjamin B. Kasten

2018-03-01

Full Text Available Triple-negative breast cancer (TNBC is an aggressive subtype of breast cancer with a poor prognosis. There is a clinical need for effective, targeted therapy strategies that destroy both differentiated TNBC cells and TNBC cancer initiating cells (CICs, as the latter are implicated in the metastasis and recurrence of TNBC. Chondroitin sulfate proteoglycan 4 (CSPG4 is overexpressed on differentiated tumor cells and CICs obtained from TNBC patient specimens, suggesting that CSPG4 may be a clinically relevant target for the imaging and therapy of TNBC. The purpose of this study was to determine whether α-particle radioimmunotherapy (RIT targeting TNBC cells using the CSPG4-specific monoclonal antibody (mAb 225.28 as a carrier was effective at eliminating TNBC tumors in preclinical models. To this end, mAb 225.28 labeled with 212Pb (212Pb-225.28 as a source of α-particles for RIT was used for in vitro Scatchard assays and clonogenic survival assays with human TNBC cells (SUM159 and 2LMP grown as adherent cells or non-adherent CIC-enriched mammospheres. Immune-deficient mice bearing orthotopic SUM159 or 2LMP xenografts were injected i.v. with the targeted (225.28 or irrelevant isotype-matched control (F3-C25 mAbs, labeled with 99mTc, 125I, or 212Pb for in vivo imaging, biodistribution, or tumor growth inhibition studies. 212Pb-225.28 bound to adherent SUM159 and 2LMP cells and to CICs from SUM159 and 2LMP mammospheres with a mean affinity of 0.5 nM. Nearly ten times more binding sites per cell were present on SUM159 cells and CICs compared with 2LMP cells. 212Pb-225.28 was six to seven times more effective than 212Pb-F3-C25 at inhibiting SUM159 cell and CIC clonogenic survival (p < 0.05. Radiolabeled mAb 225.28 showed significantly higher uptake than radiolabeled mAb F3-C25 in SUM159 and 2LMP xenografts (p < 0.05, and the uptake of 212Pb-225.28 in TNBC xenografts was correlated with target epitope expression. 212Pb-225.28 caused dose

Purification of radium-226 for the manufacturing of actinium-225 in a cyclotron for alpha-immunotherapy

International Nuclear Information System (INIS)

Marx, Sebastian Markus

2014-01-01

The thesis describes the development of methods for the purification of Ra-226. The objective was to obtain the radionuclide in the quality that is needed to be used as starting material in the manufacturing process for Ac-225 via proton-irradiated Ra-226. The radionuclide has been gained efficiently out of huge excesses of impurities. The high purity of the obtained radium affords its use as staring material in a pharmaceutical manufacturing process.

Dynamic nano-imaging of label-free living cells using electron beam excitation-assisted optical microscope

Science.gov (United States)

Fukuta, Masahiro; Kanamori, Satoshi; Furukawa, Taichi; Nawa, Yasunori; Inami, Wataru; Lin, Sheng; Kawata, Yoshimasa; Terakawa, Susumu

2015-01-01

Optical microscopes are effective tools for cellular function analysis because biological cells can be observed non-destructively and non-invasively in the living state in either water or atmosphere condition. Label-free optical imaging technique such as phase-contrast microscopy has been analysed many cellular functions, and it is essential technology for bioscience field. However, the diffraction limit of light makes it is difficult to image nano-structures in a label-free living cell, for example the endoplasmic reticulum, the Golgi body and the localization of proteins. Here we demonstrate the dynamic imaging of a label-free cell with high spatial resolution by using an electron beam excitation-assisted optical (EXA) microscope. We observed the dynamic movement of the nucleus and nano-scale granules in living cells with better than 100 nm spatial resolution and a signal-to-noise ratio (SNR) around 10. Our results contribute to the development of cellular function analysis and open up new bioscience applications. PMID:26525841

Dynamic nano-imaging of label-free living cells using electron beam excitation-assisted optical microscope.

Science.gov (United States)

Fukuta, Masahiro; Kanamori, Satoshi; Furukawa, Taichi; Nawa, Yasunori; Inami, Wataru; Lin, Sheng; Kawata, Yoshimasa; Terakawa, Susumu

2015-11-03

Optical microscopes are effective tools for cellular function analysis because biological cells can be observed non-destructively and non-invasively in the living state in either water or atmosphere condition. Label-free optical imaging technique such as phase-contrast microscopy has been analysed many cellular functions, and it is essential technology for bioscience field. However, the diffraction limit of light makes it is difficult to image nano-structures in a label-free living cell, for example the endoplasmic reticulum, the Golgi body and the localization of proteins. Here we demonstrate the dynamic imaging of a label-free cell with high spatial resolution by using an electron beam excitation-assisted optical (EXA) microscope. We observed the dynamic movement of the nucleus and nano-scale granules in living cells with better than 100 nm spatial resolution and a signal-to-noise ratio (SNR) around 10. Our results contribute to the development of cellular function analysis and open up new bioscience applications.

Electron beam generation and structure of defects in carbon and boron nitride nano-tubes

Energy Technology Data Exchange (ETDEWEB)

Zobelli, A

2007-10-15

The nature and role of defects is of primary importance to understand the physical properties of C and BN (boron nitride) single walled nano-tubes (SWNTs). Transmission electron microscopy (TEM) is a well known powerful tool to study the structure of defects in materials. However, in the case of SWNTs, the electron irradiation of the TEM may knock out atoms. This effect may alter the native structure of the tube, and has also been proposed as a potential tool for nano-engineering of nano-tubular structures. Here we develop a theoretical description of the irradiation mechanism. First, the anisotropy of the emission energy threshold is obtained via density functional based calculations. Then, we numerically derive the total Mott cross section for different emission sites of carbon and boron nitride nano-tubes with different chiralities. Using a dedicated STEM (Scanning Transmission Electron Microscope) microscope with experimental conditions optimised on the basis of derived cross-sections, we are able to control the generation of defects in nano-tubular systems. Either point or line defects can be obtained with a spatial resolution of a few nanometers. The structure, energetics and electronics of point and line defects in BN systems have been investigated. Stability of mono- and di- vacancy defects in hexagonal boron nitride layers is investigated, and their activation energies and reaction paths for diffusion have been derived using the nudged elastic band method (NEB) combined with density functional based techniques. We demonstrate that the appearance of extended linear defects under electron irradiation is more favorable than a random distribution of point defects and this is due to the existence of preferential sites for atom emission in the presence of pre-existing defects, rather than thermal vacancy nucleation and migration. (author)

Electron beam generation and structure of defects in carbon and boron nitride nano-tubes

International Nuclear Information System (INIS)

Zobelli, A.

2007-10-01

The nature and role of defects is of primary importance to understand the physical properties of C and BN (boron nitride) single walled nano-tubes (SWNTs). Transmission electron microscopy (TEM) is a well known powerful tool to study the structure of defects in materials. However, in the case of SWNTs, the electron irradiation of the TEM may knock out atoms. This effect may alter the native structure of the tube, and has also been proposed as a potential tool for nano-engineering of nano-tubular structures. Here we develop a theoretical description of the irradiation mechanism. First, the anisotropy of the emission energy threshold is obtained via density functional based calculations. Then, we numerically derive the total Mott cross section for different emission sites of carbon and boron nitride nano-tubes with different chiralities. Using a dedicated STEM (Scanning Transmission Electron Microscope) microscope with experimental conditions optimised on the basis of derived cross-sections, we are able to control the generation of defects in nano-tubular systems. Either point or line defects can be obtained with a spatial resolution of a few nanometers. The structure, energetics and electronics of point and line defects in BN systems have been investigated. Stability of mono- and di- vacancy defects in hexagonal boron nitride layers is investigated, and their activation energies and reaction paths for diffusion have been derived using the nudged elastic band method (NEB) combined with density functional based techniques. We demonstrate that the appearance of extended linear defects under electron irradiation is more favorable than a random distribution of point defects and this is due to the existence of preferential sites for atom emission in the presence of pre-existing defects, rather than thermal vacancy nucleation and migration. (author)

Fluorine-18-labeling of polymerized nano-micelles for in vivo PET imaging

International Nuclear Information System (INIS)

Kuhnast, B.; Hinnen, F.; Mackiewicz, N.; Tavitian, B.; Duconge, F.; Dolle, F.; Gravel, E.; Doris, E.

2011-01-01

Complete text of publication follows: Objectives: One of the key issues in nano-medicine, and in particular in the field of cancer treatment and follow up, is the development of nano-particles able to improve the delivery of drugs or contrast agents. It is well established that passive targeting by nano-particles is favoured by specific features of tumors, a phenomena usually defined as the enhanced permeability and retention (EPR) effect. While several nano-particulate systems in the 70- 200 nm size range have been explored for cancer targeting by the EPR effect (liposomes, dendrimers, ceramic or metallic nano-particles, carbon nano-tubes...), recent studies suggested that particles of smaller sizes (≤ 30 nm) might better diffuse through blood vessel walls and reach deeper tumor tissues. Recently, a novel series of small-sized (diameter of ca. 10 nm) and highly stable (polymerized) micelles were designed as drug nano-carriers. For in vivo 3D-imaging purposes, these micelles were provided with a sulfhydryl function permitting prosthetic conjugation with maleimide-based reagents such as AlexaFluor680 R (AF680) for optical fluorescence imaging and [ 18 F]FPyME (1-[3-(2-[ 18 F]fluoropyridin-3-yloxy)propyl]pyrrole-2, 5-dione), a prosthetic reagent labeled with the positron-emitter fluorine-18 for PET imaging, which latter work is presented herein. Methods: nano-micelles were synthesized using standard already reported procedures and comprise a defined molar ratio of functionalized diacetylene-containing poly(ethyleneglycol) (PEG-2000) lipids (pentacosa-10, 12- diyn-1-oxy-penta-tetraconta-ethylene-glycols). Preparation includes polymerization of the diacetylene functions borne by the C-25 lipophilic chains upon UV-irradiation at 254 nm via a topochemical 1, 4-addition mechanism. [ 18 F]FPyME was conjugated with the micelles in a 1/9 (v:v) mixture (1 mL) of DMSO and 0.1 M aq. PBS (pH 7.5) at room temperature for 15 min. The conjugated micelles were then separated from

Surface passivation of nano-textured fluorescent SiC by atomic layer deposited TiO2

DEFF Research Database (Denmark)

Lu, Weifang; Ou, Yiyu; Jokubavicius, Valdas

2016-01-01

Nano-textured surfaces have played a key role in optoelectronic materials to enhance the light extraction efficiency. In this work, morphology and optical properties of nano-textured SiC covered with atomic layer deposited (ALD) TiO2 were investigated. In order to obtain a high quality surface fo...

The effect of atomic hydrogen adsorption on single-walled carbon nano tubes properties

International Nuclear Information System (INIS)

Jalili, S.; Majidi, R.

2007-01-01

We investigated the adsorption of hydrogen atoms on metallic single-walled carbon nano tubes using ab initio molecular dynamics method. It was found that the geometric structures and the electronic properties of hydrogenated SWNTs can be strongly changed by varying hydrogen coverage. The circular cross sections of the CNTs were changed with different hydrogen coverage. When hydrogen is chemisorbed on the surface of the carbon nano tube, the energy gap will be appeared. This is due to the degree of the Sp 3 hybridization, and the hydrogen coverage can control the band gap of the carbon nano tube

A Radium-223 microgenerator from cyclotron-produced trace Actinium-227

International Nuclear Information System (INIS)

Abou, Diane S.; Pickett, Juile; Mattson, John E.; Thorek, Daniel L.J.

2017-01-01

The alpha particle emitter Radium-223 dichloride ("2"2"3RaCl_2) has recently been approved for treatment of late-stage bone metastatic prostate cancer. There is considerable interest in studying this new agent outside of the clinical setting, however the supply of "2"2"3Ra is limited and expensive. We have engineered a "2"2"3Ra microgenerator using traces of "2"2"7Ac previously generated from cyclotron-produced "2"2"5Ac. Radiochemically pure "2"2"3RaCl_2 was made, characterized, evaluated in vivo, and the source was recovered in high yield for regeneration of the microgenerator. - Highlights: • A "2"2"3Ra microgenerator was built using residual "2"2"7Ac from cyclotron-produced "2"2"5Ac. • Following "2"2"5Ac decay, the residual "2"2"7Ac was processed into pure "2"2"3Ra. • "2"2"7Ac and "2"2"7Th were recovered in high yield for a permanent supply of "2"2"3Ra. • Clinically supplied and generator-produced "2"2"3Ra have equivalent in vivo distribution. • Microdose column provides sufficient material for research use.

RenderGAN: Generating Realistic Labeled Data

Directory of Open Access Journals (Sweden)

Leon Sixt

2018-06-01

Full Text Available Deep Convolutional Neuronal Networks (DCNNs are showing remarkable performance on many computer vision tasks. Due to their large parameter space, they require many labeled samples when trained in a supervised setting. The costs of annotating data manually can render the use of DCNNs infeasible. We present a novel framework called RenderGAN that can generate large amounts of realistic, labeled images by combining a 3D model and the Generative Adversarial Network framework. In our approach, image augmentations (e.g., lighting, background, and detail are learned from unlabeled data such that the generated images are strikingly realistic while preserving the labels known from the 3D model. We apply the RenderGAN framework to generate images of barcode-like markers that are attached to honeybees. Training a DCNN on data generated by the RenderGAN yields considerably better performance than training it on various baselines.

Evaluation of an Anti-HER2 Nanobody Labeled with 225Ac for Targeted α-Particle Therapy of Cancer.

Science.gov (United States)

Pruszynski, Marek; D'Huyvetter, Matthias; Bruchertseifer, Frank; Morgenstern, Alfred; Lahoutte, Tony

2018-04-02

Human epidermal growth factor receptor type 2 (HER2) is overexpressed in numerous carcinomas. Nanobodies (Nbs) are the smallest antibody-derived fragments with beneficial characteristics for molecular imaging and radionuclide therapy. Therefore, HER2-targeting nanobodies could offer a valuable platform for radioimmunotherapy, especially when labeled with α-particle emitters, which provide highly lethal and localized radiation to targeted cells with minimal exposure to surrounding healthy tissues. In this study, the anti-HER2 2Rs15d-nanobody was conjugated with 2-(4-isothiocyanatobenzyl)-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid ( p-SCN-Bn-DOTA) and radiolabeled with an α-emitter 225 Ac with a high yield (>90%) and a radiochemical purity above 95%. The 225 Ac-DOTA-Nb binding affinity was 4.12 ± 0.47 nM with an immunoreactive fraction above 80%. Binding to low HER2-expressing MDA-MB-231 cells was negligible, whereas HER2-overexpressing SKOV-3 cells could be blocked with an excess of unlabeled nanobody, confirming the specificity of binding. Noncompeting binding to HER2 was observed in the presence of an excess of trastuzumab. The cell-associated fraction of 225 Ac-DOTA-Nb was 34.72 ± 16.66% over 24 h. In vitro, the radioconjugate was toxic in an HER2-mediated and dose-dependent manner, resulting in IC 50 values of 10.2 and 322.1 kBq/mL for 225 Ac-DOTA-Nb and the 225 Ac-DOTA control, respectively, on SKOV-3 cells, and 282.2 kBq/mL for 225 Ac-DOTA-Nb on MDA-MB-231 cells. Ex vivo biodistribution studies, performed in mice bearing subcutaneous HER2-overexpressing and low HER2-expressing tumors, showed a fast uptake in SKOV-3 tumors compared to MDA-MB-231 (4.01 ± 1.58% ID/g vs 0.49 ± 0.20% ID/g after 2 h), resulting also in high tumor-to-normal tissue ratios. In addition, coinjection of 225 Ac-DOTA-Nb with Gelofusine reduced kidney retention by 70%. This study shows that 225 Ac-DOTA-Nb is a promising new radioconjugate for targeted α-particle therapy

Generation and characterization of nano aluminium powder ...

Indian Academy of Sciences (India)

TECS

Generation and characterization of nano aluminium powder obtained through wire ... Department of Aerospace Engineering, Indian Institute of Technology. Madras, Chennai 600 .... pressure developed due to current flow (z-Pinch). Figure 2.

Generating Realistic Labelled, Weighted Random Graphs

Directory of Open Access Journals (Sweden)

Michael Charles Davis

2015-12-01

Full Text Available Generative algorithms for random graphs have yielded insights into the structure and evolution of real-world networks. Most networks exhibit a well-known set of properties, such as heavy-tailed degree distributions, clustering and community formation. Usually, random graph models consider only structural information, but many real-world networks also have labelled vertices and weighted edges. In this paper, we present a generative model for random graphs with discrete vertex labels and numeric edge weights. The weights are represented as a set of Beta Mixture Models (BMMs with an arbitrary number of mixtures, which are learned from real-world networks. We propose a Bayesian Variational Inference (VI approach, which yields an accurate estimation while keeping computation times tractable. We compare our approach to state-of-the-art random labelled graph generators and an earlier approach based on Gaussian Mixture Models (GMMs. Our results allow us to draw conclusions about the contribution of vertex labels and edge weights to graph structure.

Investigations on the production of labelled organic compounds by recoil labelling with gamma,n-produced 11-C-atoms

International Nuclear Information System (INIS)

Wagenbach, U.

1981-01-01

''Hot'' 11 C atoms are produced from 12 C(γ,n) 11 C nuclear reactions by bremsstrahlung at the 65 MeV electron linear accelerator in Giessen. The relative retention in various C-atoms of the amino acid, methionine, is determined by splitting of the terminal C-atoms of the molecule and by independent determination of the content of 11 C in the isolated and derived fragments. The terminal groups (thiomethyl or carboxyl groups) each carry approx. 25% of the total retained radioactivity, the remaining 50% being spread over the three inner carbon atoms. The activation of alkylamines, crystallised as hydrochlorides, hydrofluorides, oxalates and sulphates, leads to similar yields of direct labelling from 5 to 15%. Amines activated in the liquid state show a retention of less than 5%. The yields for labelled synthetic products are between 10 and 15% for amino acids and are often higher for crystallised amines. Amines activated in the liquid state produced greater yields of synthesis products but at the same time an increase in the product range. The labelled synthesis products can be separated faster by suitable methods such as preparative HPLC and are then available for carrier-free studies in the life sciences. (orig./EF) [de

Electrical characterization of Ge–Sb–Te phase change nano-pillars using conductive atomic force microscopy

International Nuclear Information System (INIS)

Bae, Byeong-Ju; Hong, Sung-Hoon; Hwang, Seon-Yong; Hwang, Jae-Yeon; Yang, Ki-Yeon; Lee, Heon

2009-01-01

The electrical characteristic of phase change material was studied in nano-scale using nanoimprint lithography and a conducting atomic force microscopy measurement system. Nanoimprint lithography was used to fabricate the nano-scale phase change material pattern. A Pt-coated AFM tip was used as a top electrode to measure the electrical characteristics of the GST nano-pillar. The GST nano-pillar, which is 200 nm in diameter, was amorphized by 2 V and 5 ns reset pulse and was then brought back to the crystalline phase by applying 1.3 V and 150 ns set pulse. Using this measurement system, the GST nano-pillar was switched between the amorphous and crystalline phases more than five times. The results of the reset and the set current measurement with the GST nano-pillar sizes show that the reset and the set currents also decreased with the decrease of the GST pillar size

Plasticity analysis of nano-grain-sized NiAl alloy in an atomic scale

International Nuclear Information System (INIS)

Wang Jingyang; Wang Xiaowei; Rifkin, J.; Li Douxing

2001-12-01

The molecular dynamics method is used to simulate a uniaxial tensile deformation of 3.8nm nano-NiAl alloy with curved amorphous-like interfaces at 0K. Plastic deformation behaviour is studied by examining the strain-stress relationship and the microstructural evolution characteristic. Atomic level analysis showed that the micro-strain is essentially heterogeneous in simulated nano-phase samples. The plastic deformation is not only attributed to the plasticity of interfaces, but also accompanied with the plastic shear strain mechanism inside lattice distortion regions and grains. (author)

Chemical generation of iodine atoms

Energy Technology Data Exchange (ETDEWEB)

Hewett, Kevin B. [Directed Energy Directorate, Air Force Research Laboratory, 3550 Aberdeen Avenue SE, Kirtland AFB, NM 87117-5776 (United States)]. E-mail: kevin.hewett@kirtland.af.mil; Hager, Gordon D. [Directed Energy Directorate, Air Force Research Laboratory, 3550 Aberdeen Avenue SE, Kirtland AFB, NM 87117-5776 (United States); Crowell, Peter G. [Northrup Grumman Information Technology, Science and Technology Operating Unit, Advanced Technology Division, P.O. Box 9377, Albuquerque, NM 87119-9377 (United States)

2005-01-10

The chemical generation of atomic iodine using a chemical combustor to generate the atomic fluorine intermediate, from the reaction of F{sub 2} + H{sub 2}, followed by the production of atomic iodine, from the reaction of F + HI, was investigated. The maximum conversion efficiency of HI into atomic iodine was observed to be approximately 75%, which is in good agreement with the theoretical model. The conversion efficiency is limited by the formation of iodine monofluoride at the walls of the combustor where the gas phase temperature is insufficient to dissociate the IF.

Analysis of the gamma spectra of the uranium, actinium, and thorium decay series

International Nuclear Information System (INIS)

Momeni, M.H.

1981-09-01

This report describes the identification of radionuclides in the uranium, actinium, and thorium series by analysis of gamma spectra in the energy range of 40 to 1400 keV. Energies and absolute efficiencies for each gamma line were measured by means of a high-resolution germanium detector and compared with those in the literature. A gamma spectroscopy method, which utilizes an on-line computer for deconvolution of spectra, search and identification of each line, and estimation of activity for each radionuclide, was used to analyze soil and uranium tailings, and ore

Label-free evanescent microscopy for membrane nano-tomography in living cells.

Science.gov (United States)

Bon, Pierre; Barroca, Thomas; Lévèque-Fort, Sandrine; Fort, Emmanuel

2014-11-01

We show that through-the-objective evanescent microscopy (epi-EM) is a powerful technique to image membranes in living cells. Readily implementable on a standard inverted microscope, this technique enables full-field and real-time tracking of membrane processes without labeling and thus signal fading. In addition, we demonstrate that the membrane/interface distance can be retrieved with 10 nm precision using a multilayer Fresnel model. We apply this nano-axial tomography of living cell membranes to retrieve quantitative information on membrane invagination dynamics. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

Determination of the Projected Atomic Potential by Deconvolution of the Auto-Correlation Function of TEM Electron Nano-Diffraction Patterns

Directory of Open Access Journals (Sweden)

Liberato De Caro

2016-11-01

Full Text Available We present a novel method to determine the projected atomic potential of a specimen directly from transmission electron microscopy coherent electron nano-diffraction patterns, overcoming common limitations encountered so far due to the dynamical nature of electron-matter interaction. The projected potential is obtained by deconvolution of the inverse Fourier transform of experimental diffraction patterns rescaled in intensity by using theoretical values of the kinematical atomic scattering factors. This novelty enables the compensation of dynamical effects typical of transmission electron microscopy (TEM experiments on standard specimens with thicknesses up to a few tens of nm. The projected atomic potentials so obtained are averaged on sample regions illuminated by nano-sized electron probes and are in good quantitative agreement with theoretical expectations. Contrary to lens-based microscopy, here the spatial resolution in the retrieved projected atomic potential profiles is related to the finer lattice spacing measured in the electron diffraction pattern. The method has been successfully applied to experimental nano-diffraction data of crystalline centrosymmetric and non-centrosymmetric specimens achieving a resolution of 65 pm.

Molecular Treatment of Nano-Kaolinite Generations.

Science.gov (United States)

Táborosi, Attila; Szilagyi, Robert K; Zsirka, Balázs; Fónagy, Orsolya; Horváth, Erzsébet; Kristóf, János

2018-06-18

A procedure is developed for defining a compositionally and structurally realistic, atomic-scale description of exfoliated clay nanoparticles from the kaolinite family of phylloaluminosilicates. By use of coordination chemical principles, chemical environments within a nanoparticle can be separated into inner, outer, and peripheral spheres. The edges of the molecular models of nanoparticles were protonated in a validated manner to achieve charge neutrality. Structural optimizations using semiempirical methods (NDDO Hamiltonians and DFTB formalism) and ab initio density functionals with a saturated basis set revealed previously overlooked molecular origins of morphological changes as a result of exfoliation. While the use of semiempirical methods is desirable for the treatment of nanoparticles composed of tens of thousands of atoms, the structural accuracy is rather modest in comparison to DFT methods. We report a comparative survey of our infrared data for untreated crystalline and various exfoliated states of kaolinite and halloysite. Given the limited availability of experimental techniques for providing direct structural information about nano-kaolinite, the vibrational spectra can be considered as an essential tool for validating structural models. The comparison of experimental and calculated stretching and bending frequencies further justified the use of the preferred level of theory. Overall, an optimal molecular model of the defect-free, ideal nano-kaolinite can be composed with respect to stationary structure and curvature of the potential energy surface using the PW91/SVP level of theory with empirical dispersion correction (PW91+D) and polarizable continuum solvation model (PCM) without the need for a scaled quantum chemical force field. This validated theoretical approach is essential in order to follow the formation of exfoliated clays and their surface reactivity that is experimentally unattainable.

Label-free detection of DNA hybridization and single point mutations in a nano-gap biosensor

International Nuclear Information System (INIS)

Zaffino, R L; Mir, M; Samitier, J

2014-01-01

We describe a conductance-based biosensor that exploits DNA-mediated long-range electron transport for the label-free and direct electrical detection of DNA hybridization. This biosensor platform comprises an array of vertical nano-gap biosensors made of gold and fabricated through standard photolithography combined with focused ion beam lithography. The nano-gap walls are covalently modified with short, anti-symmetric thiolated DNA probes, which are terminated by 19 bases complementary to both the ends of a target DNA strand. The nano-gaps are separated by a distance of 50nm, which was adjusted to fit the length of the DNA target plus the DNA probes. The hybridization of the target DNA closes the gap circuit in a switch on/off fashion, in such a way that it is readily detected by an increase in the current after nano-gap closure. The nano-biosensor shows high specificity in the discrimination of base-pair mismatching and does not require signal indicators or enhancing molecules. The design of the biosensor platform is applicable for multiplexed detection in a straightforward manner. The platform is well-suited to mass production, point-of-care diagnostics, and wide-scale DNA analysis applications. (paper)

Analysis of the differentially expressed low molecular weight peptides in human serum via an N-terminal isotope labeling technique combining nano-liquid chromatography/matrix-assisted laser desorption/ionization mass spectrometry.

Science.gov (United States)

Leng, Jiapeng; Zhu, Dong; Wu, Duojiao; Zhu, Tongyu; Zhao, Ningwei; Guo, Yinlong

2012-11-15

Peptidomics analysis of human serum is challenging due to the low abundance of serum peptides and interference from the complex matrix. This study analyzed the differentially expressed (DE) low molecular weight peptides in human serum integrating a DMPITC-based N-terminal isotope labeling technique with nano-liquid chromatography and matrix-assisted laser desorption/ionization mass spectrometry (nano-LC/MALDI-MS). The workflow introduced a [d(6)]-4,6-dimethoxypyrimidine-2-isothiocyanate (DMPITC)-labeled mixture of aliquots from test samples as the internal standard. The spiked [d(0)]-DMPITC-labeled samples were separated by nano-LC then spotted on the MALDI target. Both quantitative and qualitative studies for serum peptides were achieved based on the isotope-labeled peaks. The DMPITC labeling technique combined with nano-LC/MALDI-MS not only minimized the errors in peptide quantitation, but also allowed convenient recognition of the labeled peptides due to the 6 Da mass difference. The data showed that the entire research procedure as well as the subsequent data analysis method were effective, reproducible, and sensitive for the analysis of DE serum peptides. This study successfully established a research model for DE serum peptides using DMPITC-based N-terminal isotope labeling and nano-LC/MALDI-MS. Application of the DMPITC-based N-terminal labeling technique is expected to provide a promising tool for the investigation of peptides in vivo, especially for the analysis of DE peptides under different biological conditions. Copyright © 2012 John Wiley & Sons, Ltd.

Atomic structure and thermal stability of interfaces between metallic glass and embedding nano-crystallites revealed by molecular dynamics simulations

Energy Technology Data Exchange (ETDEWEB)

Gao, X.Z.; Yang, G.Q.; Xu, B.; Qi, C.; Kong, L.T., E-mail: konglt@sjtu.edu.cn; Li, J.F.

2015-10-25

Molecular dynamics simulations were performed to investigate the atomic structure and thermal stability of interfaces formed between amorphous Cu{sub 50}Zr{sub 50} matrix and embedding B2 CuZr nano-crystallites. The interfaces are found to be rather abrupt, and their widths show negligible dependence on the nano-crystallite size. Local atomic configuration in the interfacial region is dominated by geometry characterized by Voronoi polyhedra <0,5,2,6> and <0,4,4,6>, and the contents of these polyhedra also exhibit apparent size dependence, which in turn results in an increasing trend in the interfacial energy against the nano-crystallite size. Annealing of the interface models at elevated temperatures will also enrich these characterizing polyhedra. While when the temperature is as high as the glass transition temperature of the matrix, growth of the nano-crystallites will be appreciable. The growth activation energy also shows size dependence, which is lower for larger nano-crystallites, suggesting that large nano-crystallites are prone to grow upon thermal disturbance. - Highlights: • Special clusters characterizing the local geometry are abundant in the interfaces. • Their content varies with the size of the embedding nano-crystallite. • In turn, size dependences in interfacial thermodynamics and kinetics are observed.

Nano-Electrochemistry and Nano-Electrografting with an Original Combined AFM-SECM

Directory of Open Access Journals (Sweden)

Ammar Ben Brahim

2013-05-01

Full Text Available This study demonstrates the advantages of the combination between atomic force microscopy and scanning electrochemical microscopy. The combined technique can perform nano-electrochemical measurements onto agarose surface and nano-electrografting of non-conducting polymers onto conducting surfaces. This work was achieved by manufacturing an original Atomic Force Microscopy-Scanning ElectroChemical Microscopy (AFM-SECM electrode. The capabilities of the AFM-SECM-electrode were tested with the nano-electrografting of vinylic monomers initiated by aryl diazonium salts. Nano-electrochemical and technical processes were thoroughly described, so as to allow experiments reproducing. A plausible explanation of chemical and electrochemical mechanisms, leading to the nano-grafting process, was reported. This combined technique represents the first step towards improved nano-processes for the nano-electrografting.

Nano-Electrochemistry and Nano-Electrografting with an Original Combined AFM-SECM

Science.gov (United States)

Ghorbal, Achraf; Grisotto, Federico; Charlier, Julienne; Palacin, Serge; Goyer, Cédric; Demaille, Christophe; Ben Brahim, Ammar

2013-01-01

This study demonstrates the advantages of the combination between atomic force microscopy and scanning electrochemical microscopy. The combined technique can perform nano-electrochemical measurements onto agarose surface and nano-electrografting of non-conducting polymers onto conducting surfaces. This work was achieved by manufacturing an original Atomic Force Microscopy-Scanning ElectroChemical Microscopy (AFM-SECM) electrode. The capabilities of the AFM-SECM-electrode were tested with the nano-electrografting of vinylic monomers initiated by aryl diazonium salts. Nano-electrochemical and technical processes were thoroughly described, so as to allow experiments reproducing. A plausible explanation of chemical and electrochemical mechanisms, leading to the nano-grafting process, was reported. This combined technique represents the first step towards improved nano-processes for the nano-electrografting. PMID:28348337

Rb2Na(NO33: A Congruently Melting UV-NLO Crystal with a Very Strong Second-Harmonic Generation Response

Directory of Open Access Journals (Sweden)

Guohong Zou

2016-04-01

Full Text Available Crystals of congruently melting noncentrosymmetric (NCS mixed alkali metal nitrate, Rb2Na(NO33, have been grown through solid state reactions. The material possesses layers with NaO8 hexagonal bipyramids and NO3 triangular units. Rb+ cations are residing in the interlayer space. Each NaO8 hexagonal bipyramid shares its corners and edges with two and three NO3 units, respectively, in order to fulfill a highly dense stacking in the unit cell. The NaO8 groups share their six oxygen atoms in equatorial positions with three different NO3 groups to generate a NaO6-NO3 layer with a parallel alignment. The optimized arrangement of the NO3 groups and their high density in the structure together produce a strong second-harmonic generation (SHG response. Powder SHG measurements indicate that Rb2Na(NO33 has a strong SHG efficiency of five times that of KH2PO4 (KDP and is type I phase-matchable. The calculated average nonlinear optical (NLO susceptibility of Rb2Na(NO33 turns out to be the largest value among the NLO materials composed of only [NO3]− anion. In addition, Rb2Na(NO33 exhibits a wide transparency region ranging from UV to near IR, which suggests that the compound is a promising NLO material.

Effects of atomic-level nano-structured hydroxyapatite on adsorption of bone morphogenetic protein-7 and its derived peptide by computer simulation.

Science.gov (United States)

Wang, Qun; Wang, Menghao; Lu, Xiong; Wang, Kefeng; Fang, Liming; Ren, Fuzeng; Lu, Guoming

2017-11-09

Hydroxyapatite (HA) is the principal inorganic component of bones and teeth and has been widely used as a bone repair material because of its good biocompatibility and bioactivity. Understanding the interactions between proteins and HA is crucial for designing biomaterials for bone regeneration. In this study, we evaluated the effects of atomic-level nano-structured HA (110) surfaces on the adsorption of bone morphogenetic protein-7 (BMP-7) and its derived peptide (KQLNALSVLYFDD) using molecular dynamics and density functional theory methods. The results indicated that the atomic-level morphology of HA significantly affected the interaction strength between proteins and HA substrates. The interactions of BMP-7 and its derived peptide with nano-concave and nano-pillar HA surfaces were stronger than those with flat or nano-groove HA surfaces. The results also revealed that if the groove size of nano-structured HA surfaces matched that of residues in the protein or peptide, these residues were likely to spread into the grooves of the nano-groove, nano-concave, and nano-pillar HA, further strengthening the interactions. These results are helpful in better understanding the adsorption behaviors of proteins onto nano-structured HA surfaces, and provide theoretical guidance for designing novel bioceramic materials for bone regeneration and tissue engineering.

Ground state energy of an hydrogen atom confined in carbon nano-structures: a diffusion quantum Monte Carlo study

International Nuclear Information System (INIS)

Molayem, M.; Tayebi-Rad, Gh.; Esmaeli, L.; Namiranian, A.; Fouladvand, M. E.; Neek-Amal, M.

2006-01-01

Using the diffusion quantum monte Carlo method, the ground state energy of an Hydrogen atom confined in a carbon nano tube and a C60 molecule is calculated. For Hydrogen atom confined in small diameter tubes, the ground state energy shows significant deviation from a free Hydrogen atom, while with increasing the diameter this deviation tends to zero.

Insulated InP (100) semiconductor by nano nucleus generation in pure water

Science.gov (United States)

Ghorab, Farzaneh; Es'haghi, Zarrin

2018-01-01

Preparation of specified designs on optoelectronic devices such as Light-Emitting Diodes (LEDs) and Laser Diodes (LDs) by using insulated thin films is very important. InP as one of those semiconductors which is used as optoelectronic devices, have two different kinds of charge carriers as n-InP and p-InP in the microelectronic industry. The surface preparation of this kind of semiconductor can be accomplished with individually chemical, mechanical, chemo - mechanical and electrochemical methods. But electrochemical method can be suitably replaced instead of the other methods, like CMP (Chemical Mechanical Polishing), because of the simplicity. In this way, electrochemically formation of insulated thin films by nano nucleus generation on semiconductor (using constant current density of 0.07 mA /cm2) studied in this research. Insulated nano nucleus generation and their growth up to thin film formation on semiconductor single crystal (100), n-InP, inpure water (0.08 µs/cm,25°c) characterized by Atomic Force Microscopy (AFM), Scanning Electron Microscopy (SEM), Four-point probe and Styloprofilometer techniques. The SEM images show active and passive regions on the n-InP surface and not uniform area on p-InP surface by passing through the passive condition. So the passive regions were nonuniform, and only the active regions were uniform and clean. The various semiconducting behavior in electrochemical condition, studied and compared with structural specification of InP type group (III-V).

Characteristic of nanoparticles generated from different nano-powders by using different dispersion methods

International Nuclear Information System (INIS)

Tsai, Chuen-Jinn; Lin, Guan-Yu; Liu, Chun-Nan; He, Chi-En; Chen, Chun-Wan

2012-01-01

A standard rotating drum with a modified sampling train (RD), a vortex shaker (VS), and a SSPD (small-scale powder disperser) were used to investigate the emission characteristics of nano-powders, including nano-titanium dioxide (nano-TiO 2 , primary diameter: 21 nm), nano-zinc oxide (nano-ZnO, primary diameter: 30–50 nm), and nano-silicon dioxide (nano-SiO 2 , primary diameter: 10–30 nm). A TSI SMPS (scanning mobility particle sizer), a TSI APS (aerodynamic particle sizer), and a MSP MOUDI (micro-orifice uniform deposit impactor) were used to measure the number and mass distributions of generated particles. Significant differences in specific number and mass concentration or distributions were found among different methods and nano-powders with the most specific number and mass concentration and the smallest particles being generated by the most energetic SSPD, followed by VS and RD. Near uni-modal number or mass distributions were observed for the SSPD while bi-modal number or mass distributions existed for nano-powders except nano-SiO 2 which also exhibited bimodal mass distributions. The 30-min average results showed that the mass median aerodynamic diameter (MMAD) and number median diameter (NMD) of the SSPD ranged 1.1–2.1 μm and 166–261 nm, respectively, for all three nano-powders, which were smaller than those of the VS (MMAD: 3.3–6.0 μm and NMD: 156–462 nm), and the RD (MMAD: 5.2–11.2 μm and NMD: 198–479 nm). For nano-particles (electric mobility diameter < 100 nm), specific mass concentrations were nearly negligible for all three nano-powders and test methods. Specific number concentrations of nano-particles were low for the RD tester but were elevated when more energetic VS and SSPD testers were used. The quantitative size and concentration data obtained in this study is useful to elucidate the field emission and personal exposure data in the future provided that particle loss in the generation system is carefully assessed.

Hydrogen induced plastic damage in pressure vessel steel of 2.25Cr-1Mo

International Nuclear Information System (INIS)

Han, G.W.; Song, Y.J.

1995-01-01

2.25Cr-1Mo steel is generally employed as a hydrogenation reaction vessel material used at elevated temperature and in a hydrogen containing environment. During service of the reaction vessel, a large number of hydrogen atoms would enter its wall. When the reaction vessel is shutdown and the temperature reduces to about ambient temperature, the hydrogen atoms remaining in the wall would induce plastic damage in the steel. The mechanism of hydrogen induced plastic damage is different for various materials with different microstructures. Investigations have demonstrated that the hydrogen induced plastic damage in carbide annealed carbon steels is caused by hydrogen accelerating the initiating and growing of microvoids from the carbide particles. However, SEM examination on the fracture surface of hydrogen charged tensile specimen of 2.25Cr-1Mo steel show that a large number of fisheyes appear on the fracture surface. This indicates that hydrogen induced plastic damage in 2.25Cr-1Mo steel is related to the occurrence of fisheye cracks during plastic deformation. By means of micro-fracture mechanics to analyze fisheye crack occurrence from the first generation microvoid, the mechanism of hydrogen induced plastic damage in the pressure vessel steel is investigated

Nano-fabrication of diffractive optics for soft X-ray and atom beam focusing

International Nuclear Information System (INIS)

Rehbein, S.

2002-01-01

Nano-structuring processes are described for manufacturing diffractive optics for the condenser-monochromator set-up of the transmission X-ray microscope (TXM) and for the scanning transmission X-ray microscope (STXM) at the BESSY II electron storage ring in Berlin. Furthermore, a process for manufacturing free-standing nickel zone plates for helium atom beam focusing experiments is presented. (author)

The nano-BIon in nanostructure

Energy Technology Data Exchange (ETDEWEB)

Sepehri, Alireza, E-mail: alireza.sepehri@uk.ac.ir [Nano Research Center of the Ferdowsi University, Mashhad (Iran, Islamic Republic of); Faculty of Physics, Shahid Bahonar University, P.O. Box 76175, Kerman (Iran, Islamic Republic of)

2016-04-01

Recently, some authors have considered the superconductivity in nano-cubes and shown that by decreasing the size of these systems, superconductivity order parameter increases. In this research, we show that the same result can be obtained in a nano-BIon which is a configuration of two layers of cuprates connected by an electronic tube. This tube is a channel for transporting energy and matter inside a superconductor and acts as a wormhole in this system. This wormhole-like-tube is formed by decreasing the separation distance between layers of nano-cuprate and enhancing the cooper hopping pairing between layers. We estimate the critical temperature of superconductor and find that it depends on the size of nano-BIon and coupling between atoms in a layer. Also, we observe that external magnetic field generates a new tube which causes losing the energy density of nano-BIon between two layers and decreasing critical temperature of superconductor.

From Nano Structure to Systems: Fabrication and Characterization

International Nuclear Information System (INIS)

Uda Hashim

2011-01-01

Currently, the interest in nano technology research has been grown rapidly. With the latest technology, it is possible to arrange atoms into structures that are only a few nanometers in size. Dimension for nano structure is between 0.1 and 100nm where the actual size of 1nm is equal to 10-9 m or just about a few atoms thick. In other word, a nano structure is an object which it size is about four atom diameters or 1/50000 of a human hair. Due to the connecting of a patterned silicon substrate with biomolecules and the small size and large surface-to-volume ratio, it opens much new possibility for assembling nano structures.The ultimate goal is to fabricate devices that have every atom in the right place. Such technology would give the opportunity to minimize the size of a device and to reduce the material, energy and time necessary to perform its task. Potential applications include electrical circuits, mechanical devices and medical instruments. There are two most important nano structures that are extensively studied and researched in various organizations which are nano wire and nano gap. Nano wires is a new class of nano structure that have attracted attention and great research interest in the last few years because of their potential applications in nano technology such as nano electronic, nano mechanical and biomedical engineering. Fabrication of Nano wires is one of the great challenges today. Conventional lithography methods are not capable to produce Nano wires and even with advance nano lithography sizes below 100 nm may not easily be achieved. Nano wire can be produced in two approaches, which are top down and bottom-up method. Very small nano wires which can be produced by using top-down nano fabrication methods are Scanning Electron Microscope (SEM) based Electron Beam Lithography (EBL) method, and Spacer Patterning Lithography (SPL) method. The top-down nano fabrication method based on EBL was the design of the Nano wires Pattern Design (NPD). The

Dressed-state analysis of efficient two-dimensional atom localization in a four-level atomic system

International Nuclear Information System (INIS)

Wang, Zhiping; Yu, Benli

2014-01-01

We investigate two-dimensional atom localization via spontaneous emission in a four-level atomic system. It is found that the detection probability and precision of two-dimensional atom localization can be significantly improved due to the interference effect between the spontaneous decay channels and the dynamically induced quantum interference generated by the probe and composite fields. More importantly, a 100% probability of finding an atom within the sub-half-wavelength domain of the standing waves can be reached when the corresponding conditions are satisfied. As a result, our scheme may be helpful in laser cooling or atom nano-lithography via atom localization. (paper)

Direct Identification of Atomic-Like Electronic Levels in InAs Nano crystal Quantum Dots

International Nuclear Information System (INIS)

Millo, O.; Katz, D.

1999-01-01

The size dependent level structure of InAs nano crystals in the range 2-7 nm in diameter is investigated using both tunneling and optical spectroscopies. The tunneling measurements are performed using a cryogenic scanning tunneling microscope on individual nano crystals that, are attached to a gold substrate via dithiol molecules. The tunneling I-V characteristics manifest an interplay between single electron charging and quantum size effects. We are able to directly identify quantum confined states of isolated InAs nano crystals having s and p symmetries. These states are observed in the I-V curves as two and six-fold single electron charging multiplets. Excellent agreement is found between the strongly allowed optical transitions [1] and the spacing of levels detected in the tunneling experiment. This correlation provides new information on the quantum-dot level structure, from which we conclude that the top-most valence band state has both s and p characteristics. The interplay between level structure singles electron charging of the nano crystals obeys an atomic-like Aufbau sequential electron level occupation

Immobilization of single argon atoms in nano-cages of two-dimensional zeolite model systems.

Science.gov (United States)

Zhong, Jian-Qiang; Wang, Mengen; Akter, Nusnin; Kestell, John D; Boscoboinik, Alejandro M; Kim, Taejin; Stacchiola, Dario J; Lu, Deyu; Boscoboinik, J Anibal

2017-07-17

The confinement of noble gases on nanostructured surfaces, in contrast to bulk materials, at non-cryogenic temperatures represents a formidable challenge. In this work, individual Ar atoms are trapped at 300 K in nano-cages consisting of (alumino)silicate hexagonal prisms forming a two-dimensional array on a planar surface. The trapping of Ar atoms is detected in situ using synchrotron-based ambient pressure X-ray photoelectron spectroscopy. The atoms remain in the cages upon heating to 400 K. The trapping and release of Ar is studied combining surface science methods and density functional theory calculations. While the frameworks stay intact with the inclusion of Ar atoms, the permeability of gasses (for example, CO) through them is significantly affected, making these structures also interesting candidates for tunable atomic and molecular sieves. These findings enable the study of individually confined noble gas atoms using surface science methods, opening up new opportunities for fundamental research.

Investigating the properties and interaction mechanism of nano-silica in polyvinyl alcohol/polyacrylamide blends at an atomic level.

Science.gov (United States)

Wei, Qinghua; Wang, Yanen; Wang, Shuzhi; Zhang, Yingfeng; Chen, Xiongbiao

2017-11-01

The nano-silica can be incorporated into polymers for improved mechanical properties. Notably, the interaction between nano-silica and polymer is of a microscopic phenomenon and thus, hard to observe and study by using experimental methods. Based on molecular dynamics, this paper presents a study on the properties and the interaction mechanism of nano-silica in the polyvinyl alcohol (PVA)/polyacrylamide (PAM) blends at an atomic level. Specifically, six blends of PVA/PAM with varying concentrations of nano-silica (0-13wt%) and two interfacial interaction models of polymers on the silica surface were designed and analyzed at an atomic level in terms of concentration profile, mechanical properties, fractional free volume (FFV), dynamic properties of polymers and X-ray diffraction patterns. The concentration profile results and micromorphologies of equilibrium models suggest PAM molecular chains are easier to be adsorbed on the silica surface than PVA molecular chains in blends. The incorporation of nano-silica into the PVA/PAM blends can increase the blend mechanical properties, densities, and semicrystalline character. Meanwhile, the FFV and the mobility of polymer chain decrease with the silica concentration, which agrees with the results of mechanical properties, densities, and semicrystalline character. Our results also illustrate that an analysis of binding energies and pair correlation functions (PCF) allows for the discovery of the interaction mechanism of nano-silica in PVA/PAM blends; and that hydrogen bond interactions between polar functional groups of polymer molecular chains and the hydroxyl groups of the silica surface are involved in adsorption of the polymers on the silica surface, thus affecting the interaction mechanism of nano-silica in PVA/PAM blend systems. Copyright © 2017 Elsevier Ltd. All rights reserved.

Magnetic separation of encapsulated islet cells labeled with superparamagnetic iron oxide nano particles.

Science.gov (United States)

Mettler, Esther; Trenkler, Anja; Feilen, Peter J; Wiegand, Frederik; Fottner, Christian; Ehrhart, Friederike; Zimmermann, Heiko; Hwang, Yong Hwa; Lee, Dong Yun; Fischer, Stefan; Schreiber, Laura M; Weber, Matthias M

2013-01-01

Islet cell transplantation is a promising option for the restoration of normal glucose homeostasis in patients with type 1 diabetes. Because graft volume is a crucial issue in islet transplantations for patients with diabetes, we evaluated a new method for increasing functional tissue yield in xenogeneic grafts of encapsulated islets. Islets were labeled with three different superparamagnetic iron oxide nano particles (SPIONs; dextran-coated SPION, siloxane-coated SPION, and heparin-coated SPION). Magnetic separation was performed to separate encapsulated islets from the empty capsules, and cell viability and function were tested. Islets labeled with 1000 μg Fe/ml dextran-coated SPIONs experienced a 69.9% reduction in graft volume, with a 33.2% loss of islet-containing capsules. Islets labeled with 100 μg Fe/ml heparin-coated SPIONs showed a 46.4% reduction in graft volume, with a 4.5% loss of capsules containing islets. No purification could be achieved using siloxane-coated SPIONs due to its toxicity to the primary islets. SPION labeling of islets is useful for transplant purification during islet separation as well as in vivo imaging after transplantation. Furthermore, purification of encapsulated islets can also reduce the volume of the encapsulated islets without impairing their function by removing empty capsules. © 2013 John Wiley & Sons A/S.

Chemical Imaging of the Cell Membrane by NanoSIMS

International Nuclear Information System (INIS)

Weber, P.K.; Kraft, M.L.; Frisz, J.F.; Carpenter, K.J.; Hutcheon, I.D.

2010-01-01

Cameca NanoSIMS 50 to probe membrane organization and test microdomain hypotheses. The NanoSIMS is an imaging secondary ion mass spectrometer with an unprecedented combination of spatial resolution, sensitivity and mass specificity. It has 50 nm lateral resolution and is capable of detecting 1 in 20 nitrogen atoms while excluding near-neighbor isobaric interferences. The tightly focused cesium ion beam is rastered across the sample to produce simultaneous, quantitative digital images of up to five different masses. By labeling each specific components of a membrane with a unique rare stable isotope or element and mapping the location of the labels with the NanoSIMS, the location of the each labeled component can be determined and quantified. This new approach to membrane composition analysis allows molecular interactions of biological membranes to be probed at length-scales relevant to lipid rafts (10s to 100s of nm) that were not previously possible. Results from our most recent experiments analyzing whole cells will be presented.

Sub-cellular localisation of a 15N-labelled peptide vector using NanoSIMS imaging

Science.gov (United States)

Römer, Winfried; Wu, Ting-Di; Duchambon, Patricia; Amessou, Mohamed; Carrez, Danièle; Johannes, Ludger; Guerquin-Kern, Jean-Luc

2006-07-01

Dynamic SIMS imaging is proposed to map sub-cellular distributions of isotopically labelled, exogenous compounds. NanoSIMS imaging allows the characterisation of the intracellular transport pathways of exogenous molecules, including peptide vectors employed in innovative therapies, using stable isotopes as molecular markers to detect the compound of interest. Shiga toxin B-subunit (STxB) was chosen as a representative peptide vector. The recombinant protein ( 15N-STxB) was synthesised in Escherichia coli using 15NH 4Cl as sole nitrogen source resulting in 15N enrichment in the molecule. Using the NanoSIMS 50 ion microprobe (Cameca), different ion species ( 12C 14N -, 12C 15N -, 31P -) originating from the same sputtered micro volume were simultaneously detected. High mass resolving power enabled the discrimination of 12C 15N - from its polyatomic isobars of mass 27. We imaged the membrane binding and internalisation of 15N-STxB in HeLa cells at spatial resolutions of less than 100 nm. Thus, the use of rare stable isotopes like 15N with dynamic SIMS imaging permits sub-cellular detection of isotopically labelled, exogenous molecules and imaging of their transport pathways at high mass and spatial resolution. Application of stable isotopes as markers can replace the large and chemically complex tags used for fluorescence microscopy, without altering the chemical and physical properties of the molecule.

Observation of terahertz-radiation-induced ionization in a single nano island.

Science.gov (United States)

Seo, Minah; Kang, Ji-Hun; Kim, Hyo-Suk; Hyong Cho, Joon; Choi, Jaebin; Min Jhon, Young; Lee, Seok; Hun Kim, Jae; Lee, Taikjin; Park, Q-Han; Kim, Chulki

2015-05-22

Terahertz (THz) electromagnetic wave has been widely used as a spectroscopic probe to detect the collective vibrational mode in vast molecular systems and investigate dielectric properties of various materials. Recent technological advances in generating intense THz radiation and the emergence of THz plasmonics operating with nanoscale structures have opened up new pathways toward THz applications. Here, we present a new opportunity in engineering the state of matter at the atomic scale using THz wave and a metallic nanostructure. We show that a medium strength THz radiation of 22 kV/cm can induce ionization of ambient carbon atoms through interaction with a metallic nanostructure. The prepared structure, made of a nano slot antenna and a nano island located at the center, acts as a nanogap capacitor and enhances the local electric field by two orders of magnitudes thereby causing the ionization of ambient carbon atoms. Ionization and accumulation of carbon atoms are also observed through the change of the resonant condition of the nano slot antenna and the shift of the characteristic mode in the spectrum of the transmitted THz waves.

Transferring metallic nano-island on hydrogen passivated silicon surface for nano-electronics

International Nuclear Information System (INIS)

Deng, J; Troadec, C; Joachim, C

2009-01-01

In a planar configuration, precise positioning of ultra-flat metallic nano-islands on semiconductor surface opens a way to construct nanostructures for atomic scale interconnects. Regular triangular Au nano-islands have been grown on atomically flat MoS 2 substrates and manipulated by STM to form nanometer gap metal-pads connector for single molecule electronics study. The direct assembly of regular shaped metal nano-islands on H-Si(100) is not achievable. Here we present how to transfer Au triangle nano-islands from MoS 2 onto H-Si(100) in a clean manner. In this experiment, clean MoS 2 substrates are patterned as array of MoS 2 pillars with height of 8 μm. The Au triangle nano-islands are grown on top of the pillars. Successful printing transfer of these Au nano-islands from the MoS 2 pillars to the H-Si(100) is demonstrated.

Generation of nano roughness on fibrous materials by atmospheric plasma

International Nuclear Information System (INIS)

Kulyk, I; Scapinello, M; Stefan, M

2012-01-01

Atmospheric plasma technology finds novel applications in textile industry. It eliminates the usage of water and of hazard liquid chemicals, making production much more eco-friendly and economically convenient. Due to chemical effects of atmospheric plasma, it permits to optimize dyeing and laminating affinity of fabrics, as well as anti-microbial treatments. Other important applications such as increase of mechanical resistance of fiber sleeves and of yarns, anti-pilling properties of fabrics and anti-shrinking property of wool fabrics were studied in this work. These results could be attributed to the generation of nano roughness on fibers surface by atmospheric plasma. Nano roughness generation is extensively studied at different conditions. Alternative explanations for the important practical results on textile materials and discussed.

Visualizing Microbial Biogeochemistry: NanoSIMS and Stable Isotope Probing (Invited)

Science.gov (United States)

Pett-Ridge, J.; Weber, P. K.

2009-12-01

Linking phylogenetic information to function in microbial communities is a key challenge for microbial ecology. Isotope-labeling experiments provide a useful means to investigate the ecophysiology of microbial populations and cells in the environment and allow measurement of nutrient transfers between cell types, symbionts and consortia. The combination of Nano-Secondary Ion Mass Spectrometry (NanoSIMS) analysis, in situ labeling and high resolution microscopy allows isotopic analysis to be linked to phylogeny and morphology and holds great promise for fine-scale studies of microbial systems. In NanoSIMS analysis, samples are sputtered with an energetic primary beam (Cs+, O-) liberating secondary ions that are separated by the mass spectrometer and detected in a suite of electron multipliers. Five isotopic species may be analyzed concurrently with spatial resolution as fine as 50nm. A high sensitivity isotope ratio ‘map’ can then be generated for the analyzed area. NanoSIMS images of 13C, 15N and Mo (a nitrogenase co-factor) localization in diazotrophic cyanobacteria show how cells differentially allocate resources within filaments and allow calculation of nutrient uptake rates on a cell by cell basis. Images of AM fungal hyphae-root and cyanobacteria-rhizobia associations indicate the mobilization and sharing (stealing?) of newly fixed C and N. In a related technique, “El-FISH”, stable isotope labeled biomass is probed with oligonucleotide-elemental labels and then imaged by NanoSIMS. In microbial consortia and cyanobacterial mats, this technique helps link microbial structure and function simultaneously even in systems with unknown and uncultivated microbes. Finally, the combination of re-engineered universal 16S oligonucleotide microarrays with NanoSIMS analyses may allow microbial identity to be linked to functional roles in complex systems such as mats and cellulose degrading hindgut communities. These newly developed methods provide correlated

Guided mass spectrum labelling in atom probe tomography

International Nuclear Information System (INIS)

Haley, D.; Choi, P.; Raabe, D.

2015-01-01

Atom probe tomography (APT) is a valuable near-atomic scale imaging technique, which yields mass spectrographic data. Experimental correctness can often pivot on the identification of peaks within a dataset, this is a manual process where subjectivity and errors can arise. The limitations of manual procedures complicate APT experiments for the operator and furthermore are a barrier to technique standardisation. In this work we explore the capabilities of computer-guided ranging to aid identification and analysis of mass spectra. We propose a fully robust algorithm for enumeration of the possible identities of detected peak positions, which assists labelling. Furthermore, a simple ranking scheme is developed to allow for evaluation of the likelihood of each possible identity being the likely assignment from the enumerated set. We demonstrate a simple, yet complete work-chain that allows for the conversion of mass-spectra to fully identified APT spectra, with the goal of minimising identification errors, and the inter-operator variance within APT experiments. This work chain is compared to current procedures via experimental trials with different APT operators, to determine the relative effectiveness and precision of the two approaches. It is found that there is little loss of precision (and occasionally gain) when participants are given computer assistance. We find that in either case, inter-operator precision for ranging varies between 0 and 2 “significant figures” (2σ confidence in the first n digits of the reported value) when reporting compositions. Intra-operator precision is weakly tested and found to vary between 1 and 3 significant figures, depending upon species composition levels. Finally it is suggested that inconsistencies in inter-operator peak labelling may be the largest source of scatter when reporting composition data in APT. - Highlights: • Demonstration of a complete, but simple, automation chain for APT spectra analysis. • Algorithm for

Guided mass spectrum labelling in atom probe tomography

Energy Technology Data Exchange (ETDEWEB)

Haley, D., E-mail: daniel.haley@materials.ox.ac.uk [Max-Planck-Institut für Eisenforschung, Max-Plack Straße 1, Düsseldorf (Germany); Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH (United Kingdom); Choi, P.; Raabe, D. [Max-Planck-Institut für Eisenforschung, Max-Plack Straße 1, Düsseldorf (Germany)

2015-12-15

Atom probe tomography (APT) is a valuable near-atomic scale imaging technique, which yields mass spectrographic data. Experimental correctness can often pivot on the identification of peaks within a dataset, this is a manual process where subjectivity and errors can arise. The limitations of manual procedures complicate APT experiments for the operator and furthermore are a barrier to technique standardisation. In this work we explore the capabilities of computer-guided ranging to aid identification and analysis of mass spectra. We propose a fully robust algorithm for enumeration of the possible identities of detected peak positions, which assists labelling. Furthermore, a simple ranking scheme is developed to allow for evaluation of the likelihood of each possible identity being the likely assignment from the enumerated set. We demonstrate a simple, yet complete work-chain that allows for the conversion of mass-spectra to fully identified APT spectra, with the goal of minimising identification errors, and the inter-operator variance within APT experiments. This work chain is compared to current procedures via experimental trials with different APT operators, to determine the relative effectiveness and precision of the two approaches. It is found that there is little loss of precision (and occasionally gain) when participants are given computer assistance. We find that in either case, inter-operator precision for ranging varies between 0 and 2 “significant figures” (2σ confidence in the first n digits of the reported value) when reporting compositions. Intra-operator precision is weakly tested and found to vary between 1 and 3 significant figures, depending upon species composition levels. Finally it is suggested that inconsistencies in inter-operator peak labelling may be the largest source of scatter when reporting composition data in APT. - Highlights: • Demonstration of a complete, but simple, automation chain for APT spectra analysis. • Algorithm for

NanoCrySP technology for generation of drug nanocrystals: translational aspects and business potential.

Science.gov (United States)

Shete, Ganesh; Bansal, Arvind Kumar

2016-08-01

Drug nanocrystals have rapidly evolved into a mature drug delivery strategy in the last decade, with almost 16 products currently on the market. Several "top-down" technologies are available in the market for generation of nanocrystals. Despite several advantages, very few bottom-up technologies have been explored for commercial purpose. This short communication highlights a novel, bottom-up, spray drying based technology-NanoCrySP-to generate drug nanocrystals. Nanocrystals are generated in the presence of non-polymeric excipients that act as crystallization inducer for the drug. Excipients encourage crystallization of drug by plasticization, primary heterogeneous nucleation, and imparting physical barrier to crystal growth. Nanocrystals have shown significant improvement in dissolution and thereby oral bioavailability. NanoCrySP technology is protected through patents in India, the USA, and the European Union. NanoCrySP can be utilized for (i) pharmaceutical development of new chemical entities, (ii) differentiated products of existing molecules, and (iii) generic drug products. The aggregation of drug nanocrystals generated using NanoCrySP poses significant challenges in the nanocrystal-based product development. Addition of stabilizers either during spray drying or during dissolution has shown beneficial effects.

40 CFR 1033.225 - Amending applications for certification

Science.gov (United States)

2010-07-01

...) AIR POLLUTION CONTROLS CONTROL OF EMISSIONS FROM LOCOMOTIVES Certifying Engine Families § 1033.225... produce 12-cylinder versions of the 16-cylinder locomotives you described in your application. (2) Change... the new FEL on the emission control information label for all locomotives produced after the change...

Improved experimental limit on the EDM of 225Ra

Science.gov (United States)

Bishof, Michael; Bailey, Kevin; Dietrich, Matthew R.; Greene, John P.; Holt, Roy J.; Kalita, Mukut R.; Korsch, Wolfgang; Lemke, Nathan D.; Lu, Zheng-Tian; Mueller, Peter; O'Connor, Tom P.; Parker, Richard H.; Rabga, Tenzin; Singh, Jaideep T.

2015-10-01

Searches for permanent electric dipole moments (EDMs) in fundamental and composite particles are sensitive probes of beyond-standard-model symmetry violation that could explain the dominance of matter over anti-matter. The 225Ra (t1/2 = 15d, I = 1/2) atom is a particularly attractive system to use for an EDM measurement because its large nuclear octupole deformation, closely spaced ground-state parity doublet, and large atomic mass make 225Ra uniquely sensitive to symmetry-violating interactions in the nuclear medium. We have developed an experiment to measure the EDM of 225Ra and demonstrated the first ``proof-of-principle'' measurement, giving a 95% confidence upper limit of 5E-22 e-cm. After implementing a vacuum upgrade, we have observed nuclear spin coherence after 20 s of free evolution - a factor of ten improvement over our earlier results - and have lowered the 225Ra EDM limit by over an order of magnitude. Upcoming experimental upgrades have the potential to further improve our EDM sensitivity by many orders of magnitude, allowing us to test symmetry violation at an unprecedented level. This work is supported by U.S. DOE, Office of Science, Office of Nuclear Physics, under Contract DE-AC02-06CH11357.

Decay schemes of the radioactive nuclei A = 225 to 229. Skhemy raspada radioaktivnykh yader A = 225 - 229

Energy Technology Data Exchange (ETDEWEB)

Dzhelepov, B S; Ivanov, R B; Mikhailova, M A

1976-01-01

This monograph is devoted to properties of atomic nuclei with mass numbers A = 225 to 229. The book collects and systematizes all of the experimental data characterizing properties of radioactive isotopes: information concerning masses of nuclei, magnetic and electric moments, lifetimes of nuclear states, the most reliable information on characteristics of radiations, quantum characteristics of levels and other properties of the studied nuclei. On basis of a critical analysis of the totality of information, decay schemes of radioactive nuclei with mass numbers A = 225 to 229 were constructed, as well as the series of excited states of the isotopes which lie in this region of nuclei.

Women's Relationship to Feminism: Effects of Generation and Feminist Self-Labeling

Science.gov (United States)

Duncan, Lauren E.

2010-01-01

The relative importance to feminism of generation and feminist self-labeling was explored in a sample of 667 women riding buses to a 1992 March on Washington for Reproductive Rights. Specifically, generational (Generation X vs. Baby Boomers) and feminist self-labeling (strong feminists vs. weak feminists vs. nonfeminists) similarities and…

H2 uptake in the Li-dispersed silica nano-tubes

International Nuclear Information System (INIS)

Jin Bae Lee; Soon Chang Lee; Sang Moon Lee; Hae Jin Kim

2006-01-01

Highly ordered Li-dispersed silica nano-tubes were prepared by sol-gel template method for hydrogen storage. Isolated Li-dispersed silica nano-tubes can be easily obtained by removing the AAO template with 2M NaOH. From the XRD study, the Li-dispersed silica nano-tubes showed the amorphous phase with silica frameworks. The uniform length and diameter of Li-dispersed silica nano-tubes could be examined with the electron microscopy studies. The wall thickness and diameter of nano-tubes are about 50-60 nm and 200-400 nm, respectively. The obtained Li-dispersed silica nano-tubes have the hydrogen adsorption capacity 2.25 wt% at 77 K under 47 atm. (authors)

Design and synthesis of 225Ac radioimmunopharmaceuticals

International Nuclear Information System (INIS)

McDevitt, Michael R.; Ma, Dangshe; Simon, Jim; Frank, R. Keith; Scheinberg, David A.

2002-01-01

The alpha-particle-emitting radionuclides 213 Bi, 211 At, 224 Ra are under investigation for the treatment of leukemias, gliomas, and ankylosing spondylitis, respectively. 213 Bi and 211 At were attached to monoclonal antibodies and used as targeted immunotherapeutic agents while unconjugated 224 Ra chloride selectively seeks bone. 225 Ac possesses favorable physical properties for radioimmunotherapy (10 d half-life and 4 net alpha particles), but has a history of unfavorable radiolabeling chemistry and poor metal-chelate stability. We selected functionalized derivatives of DOTA as the most promising to pursue from out of a group of potential 225 Ac chelate compounds. A two-step synthetic process employing either MeO-DOTA-NCS or 2B-DOTA-NCS as the chelating moiety was developed to attach 225 Ac to monoclonal antibodies. This method was tested using several different IgG systems. The chelation reaction yield in the first step was 93±8% radiochemically pure (n=26). The second step yielded 225 Ac-DOTA-IgG constructs that were 95±5% radiochemically pure (n=27) and the mean percent immunoreactivity ranged from 25% to 81%, depending on the antibody used. This process has yielded several potential novel targeted 225 Ac-labeled immunotherapeutic agents that may now be evaluated in appropriate model systems and ultimately in humans

Fabrication of nano-sized magnetic tunnel junctions using lift-off process assisted by atomic force probe tip.

Science.gov (United States)

Jung, Ku Youl; Min, Byoung-Chul; Ahn, Chiyui; Choi, Gyung-Min; Shin, Il-Jae; Park, Seung-Young; Rhie, Kungwon; Shin, Kyung-Ho

2013-09-01

We present a fabrication method for nano-scale magnetic tunnel junctions (MTJs), employing e-beam lithography and lift-off process assisted by the probe tip of atomic force microscope (AFM). It is challenging to fabricate nano-sized MTJs on small substrates because it is difficult to use chemical mechanical planarization (CMP) process. The AFM-assisted lift-off process enables us to fabricate nano-sized MTJs on small substrates (12.5 mm x 12.5 mm) without CMP process. The e-beam patterning has been done using bi-layer resist, the poly methyl methacrylate (PMMA)/ hydrogen silsesquioxane (HSQ). The PMMA/HSQ resist patterns are used for both the etch mask for ion milling and the self-aligned mask for top contact formation after passivation. The self-aligned mask buried inside a passivation oxide layer, is readily lifted-off by the force exerted by the probe tip. The nano-MTJs (160 nm x 90 nm) fabricated by this method show clear current-induced magnetization switching with a reasonable TMR and critical switching current density.

Self-organized semiconductor nano-network on graphene

Science.gov (United States)

Son, Dabin; Kim, Sang Jin; Lee, Seungmin; Bae, Sukang; Kim, Tae-Wook; Kang, Jae-Wook; Lee, Sang Hyun

2017-04-01

A network structure consisting of nanomaterials with a stable structural support and charge path on a large area is desirable for various electronic and optoelectronic devices. Generally, network structures have been fabricated via two main strategies: (1) assembly of pre-grown nanostructures onto a desired substrate and (2) direct growth of nanomaterials onto a desired substrate. In this study, we utilized the surface defects of graphene to form a nano-network of ZnO via atomic layer deposition (ALD). The surface of pure and structurally perfect graphene is chemically inert. However, various types of point and line defects, including vacancies/adatoms, grain boundaries, and ripples in graphene are generated by growth, chemical or physical treatments. The defective sites enhance the chemical reactivity with foreign atoms. ZnO nanoparticles formed by ALD were predominantly deposited at the line defects and agglomerated with increasing ALD cycles. Due to the formation of the ZnO nano-network, the photocurrent between two electrodes was clearly changed under UV irradiation as a result of the charge transport between ZnO and graphene. The line patterned ZnO/graphene (ZnO/G) nano-network devices exhibit sensitivities greater than ten times those of non-patterned structures. We also confirmed the superior operation of a fabricated flexible photodetector based on the line patterned ZnO/G nano-network.

Functionalized NaA nanozeolites labeled with 224,225Ra for targeted alpha therapy.

Science.gov (United States)

Piotrowska, Agata; Leszczuk, Edyta; Bruchertseifer, Frank; Morgenstern, Alfred; Bilewicz, Aleksander

2013-01-01

The 223 Ra, 224 Ra, and 225 Ra radioisotopes exhibit very attractive nuclear properties for application in radionuclide therapy. Unfortunately the lack of appropriate bifunctional ligand for radium is the reason why these radionuclides have not found application in receptor-targeted therapy. In the present work, the potential usefulness of the NaA nanozeolite as a carrier for radium radionuclides has been studied. 224 Ra and 225 Ra, α-particle emitting radionuclides, have been absorbed in the nanometer-sized NaA zeolite (30-70 nm) through simple ion exchange. 224,225 Ra-nanozeolites exhibited very high stability in solutions containing physiological salt, EDTA, amino acids, and human serum. To make NaA nanozeolite particles dispersed in water their surface was modified with a silane coupling agent containing poly(ethylene glycol) molecules. This functionalization approach let us covalently attach a biomolecule to the NaA nanozeolite surface.

Rapid label-free profiling of oral cancer biomarker proteins using nano-UPLC-Q-TOF ion mobility mass spectrometry.

Science.gov (United States)

Nassar, Ala F; Williams, Brad J; Yaworksy, Dustin C; Patel, Vyomesh; Rusling, James F

2016-03-01

It has become quite clear that single cancer biomarkers cannot in general provide high sensitivity and specificity for reliable clinical cancer diagnostics. This paper explores the feasibility of rapid detection of multiple biomarker proteins in model oral cancer samples using label-free protein relative quantitation. MS-based label-free quantitative proteomics offer a rapid alternative that bypasses the need for stable isotope containing compounds to chemically bind and label proteins. Total protein content in oral cancer cell culture conditioned media was precipitated, subjected to proteolytic digestion, and then analyzed using a nano-UPLC (where UPLC is ultra-performance liquid chromatography) coupled to a hybrid Q-Tof ion-mobility mass spectrometry (MS). Rapid, simultaneous identification and quantification of multiple possible cancer biomarker proteins was achieved. In a comparative study between cancer and noncancer samples, approximately 952 proteins were identified using a high-throughput 1D ion mobility assisted data independent acquisition (IM-DIA) approach. As we previously demonstrated that interleukin-8 (IL-8) and vascular endothelial growth factor A (VEGF-A) were readily detected in oral cancer cell conditioned media(1), we targeted these biomarker proteins to validate our approach. Target biomarker protein IL-8 was found between 3.5 and 8.8 fmol, while VEGF-A was found at 1.45 fmol in the cancer cell media. Overall, our data suggest that the nano-UPLC-IM-DIA bioassay is a feasible approach to identify and quantify proteins in complex samples without the need for stable isotope labeling. These results have significant implications for rapid tumor diagnostics and prognostics by monitoring proteins such as IL-8 and VEGF-A implicated in cancer development and progression. The analysis in tissue or plasma is not possible at this time, but the subsequent work would be needed for validation. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Evaluation of preparation methods for suspended nano-objects on substrates for dimensional measurements by atomic force microscopy

Directory of Open Access Journals (Sweden)

Petra Fiala

2017-08-01

Full Text Available Dimensional measurements on nano-objects by atomic force microscopy (AFM require samples of safely fixed and well individualized particles with a suitable surface-specific particle number on flat and clean substrates. Several known and proven particle preparation methods, i.e., membrane filtration, drying, rinsing, dip coating as well as electrostatic and thermal precipitation, were performed by means of scanning electron microscopy to examine their suitability for preparing samples for dimensional AFM measurements. Different suspensions of nano-objects (with varying material, size and shape stabilized in aqueous solutions were prepared therefore on different flat substrates. The drop-drying method was found to be the most suitable one for the analysed suspensions, because it does not require expensive dedicated equipment and led to a uniform local distribution of individualized nano-objects. Traceable AFM measurements based on Si and SiO2 coated substrates confirmed the suitability of this technique.

Evaluation of preparation methods for suspended nano-objects on substrates for dimensional measurements by atomic force microscopy.

Science.gov (United States)

Fiala, Petra; Göhler, Daniel; Wessely, Benno; Stintz, Michael; Lazzerini, Giovanni Mattia; Yacoot, Andrew

2017-01-01

Dimensional measurements on nano-objects by atomic force microscopy (AFM) require samples of safely fixed and well individualized particles with a suitable surface-specific particle number on flat and clean substrates. Several known and proven particle preparation methods, i.e., membrane filtration, drying, rinsing, dip coating as well as electrostatic and thermal precipitation, were performed by means of scanning electron microscopy to examine their suitability for preparing samples for dimensional AFM measurements. Different suspensions of nano-objects (with varying material, size and shape) stabilized in aqueous solutions were prepared therefore on different flat substrates. The drop-drying method was found to be the most suitable one for the analysed suspensions, because it does not require expensive dedicated equipment and led to a uniform local distribution of individualized nano-objects. Traceable AFM measurements based on Si and SiO 2 coated substrates confirmed the suitability of this technique.

Enzymatically Generated CRISPR Libraries for Genome Labeling and Screening.

Science.gov (United States)

Lane, Andrew B; Strzelecka, Magdalena; Ettinger, Andreas; Grenfell, Andrew W; Wittmann, Torsten; Heald, Rebecca

2015-08-10

CRISPR-based technologies have emerged as powerful tools to alter genomes and mark chromosomal loci, but an inexpensive method for generating large numbers of RNA guides for whole genome screening and labeling is lacking. Using a method that permits library construction from any source of DNA, we generated guide libraries that label repetitive loci or a single chromosomal locus in Xenopus egg extracts and show that a complex library can target the E. coli genome at high frequency. Copyright © 2015 Elsevier Inc. All rights reserved.

Generation of atom-photon entangled states in atomic Bose-Einstein condensate via electromagnetically induced transparency

International Nuclear Information System (INIS)

Kuang Leman; Zhou Lan

2003-01-01

In this paper, we present a method to generate continuous-variable-type entangled states between photons and atoms in atomic Bose-Einstein condensate (BEC). The proposed method involves an atomic BEC with three internal states, a weak quantized probe laser, and a strong classical coupling laser, which form a three-level Λ-shaped BEC system. We consider a situation where the BEC is in electromagnetically induced transparency with the coupling laser being much stronger than the probe laser. In this case, the upper and intermediate levels are unpopulated, so that their adiabatic elimination enables an effective two-mode model involving only the atomic field at the lowest internal level and the quantized probe laser field. Atom-photon quantum entanglement is created through laser-atom and interatomic interactions, and two-photon detuning. We show how to generate atom-photon entangled coherent states and entangled states between photon (atom) coherent states and atom-(photon-) macroscopic quantum superposition (MQS) states, and between photon-MQS and atom-MQS states

Nano surface generation of grinding process using carbon nano tubes

Indian Academy of Sciences (India)

Nano surface finish has become an important parameter in the semiconductor, optical, electrical and mechanical industries. The materials used in these industries are classified as difficult to machine materials such as ceramics, glasses and silicon wafers. Machining of these materials up to nano accuracy is a great ...

Ultratrace determination of tin by hydride generation in-atomizer trapping atomic absorption spectrometry

Energy Technology Data Exchange (ETDEWEB)

Průša, Libor [Institute of Analytical Chemistry of the ASCR, v. v. i., Veveří 97, 602 00 Brno (Czech Republic); Charles University in Prague, Faculty of Science, Department of Analytical Chemistry, Hlavova 8, Prague 2, CZ 128 43 Czech Republic (Czech Republic); Dědina, Jiří [Institute of Analytical Chemistry of the ASCR, v. v. i., Veveří 97, 602 00 Brno (Czech Republic); Kratzer, Jan, E-mail: jkratzer@biomed.cas.cz [Institute of Analytical Chemistry of the ASCR, v. v. i., Veveří 97, 602 00 Brno (Czech Republic)

2013-12-04

Graphical abstract: -- Highlights: •In-atomizer trapping HG-AAS was optimized for Sn. •A compact quartz trap-and-atomizer device was employed. •Generation, preconcentration and atomization steps were investigated in detail. •Hundred percent preconcentration efficiency for tin was reached. •Routine analytical method was developed for Sn determination (LOD of 0.03 ng mL{sup −1} Sn). -- Abstract: A quartz multiatomizer with its inlet arm modified to serve as a trap (trap-and-atomizer device) was employed to trap tin hydride and subsequently to volatilize collected analyte species with atomic absorption spectrometric detection. Generation, atomization and preconcentration conditions were optimized and analytical figures of merit of both on-line atomization as well as preconcentration modes were quantified. Preconcentration efficiency of 95 ± 5% was found. The detection limits reached were 0.029 and 0.14 ng mL{sup −1} Sn, respectively, for 120 s preconcentration period and on-line atomization mode without any preconcentration. The interference extent of other hydride forming elements (As, Se, Sb and Bi) on tin determination was found negligible in both modes of operation. The applicability of the developed preconcentration method was verified by Sn determination in a certified reference material as well as by analysis of real samples.

Design and synthesis of {sup 225}Ac radioimmunopharmaceuticals

Energy Technology Data Exchange (ETDEWEB)

McDevitt, Michael R.; Ma, Dangshe; Simon, Jim; Frank, R. Keith; Scheinberg, David A. E-mail: d-scheinberg@ski.mskcc.org

2002-12-01

The alpha-particle-emitting radionuclides {sup 213}Bi, {sup 211}At, {sup 224}Ra are under investigation for the treatment of leukemias, gliomas, and ankylosing spondylitis, respectively. {sup 213}Bi and {sup 211}At were attached to monoclonal antibodies and used as targeted immunotherapeutic agents while unconjugated {sup 224}Ra chloride selectively seeks bone. {sup 225}Ac possesses favorable physical properties for radioimmunotherapy (10 d half-life and 4 net alpha particles), but has a history of unfavorable radiolabeling chemistry and poor metal-chelate stability. We selected functionalized derivatives of DOTA as the most promising to pursue from out of a group of potential {sup 225}Ac chelate compounds. A two-step synthetic process employing either MeO-DOTA-NCS or 2B-DOTA-NCS as the chelating moiety was developed to attach {sup 225}Ac to monoclonal antibodies. This method was tested using several different IgG systems. The chelation reaction yield in the first step was 93{+-}8% radiochemically pure (n=26). The second step yielded {sup 225}Ac-DOTA-IgG constructs that were 95{+-}5% radiochemically pure (n=27) and the mean percent immunoreactivity ranged from 25% to 81%, depending on the antibody used. This process has yielded several potential novel targeted {sup 225}Ac-labeled immunotherapeutic agents that may now be evaluated in appropriate model systems and ultimately in humans.

Novel nano-cellulose excipient for generating non-Newtonian droplets for targeted nasal drug delivery.

Science.gov (United States)

Young, Paul M; Traini, Daniela; Ong, Hui Xin; Granieri, Angelo; Zhu, Bing; Scalia, Santo; Song, Jie; Spicer, Patrick T

2017-10-01

Thickening polymers have been used as excipients in nasal formulations to avoid nasal run-off (nasal drip) post-administration. However, increasing the viscosity of the formulation can have a negative impact on the quality of the aerosols generated. Therefore, the study aims to investigate the use of a novel smart nano-cellulose excipient to generate suitable droplets for nasal drug delivery that simultaneously has only marginally increased viscosity while still reducing nasal drips. Nasal sprays containing nano-cellulose at different concentrations were investigated for the additive's potential as an excipient. The formulations were characterized for their rheological and aerosol properties. This was then compared to conventional nasal spray formulation containing the single-component hydroxyl-propyl methyl cellulose (HPMC) viscosity enhancing excipient. The HPMC-containing nasal formulations behave in a Newtonian manner while the nano-cellulose formulations have a yield stress and shear-thinning properties. At higher excipient concentrations and shear rates, the nano-cellulose solutions have significantly lower viscosities compared to the HPMC solution, resulting in improved droplet formation when actuated through conventional nasal spray. Nano-cellulose materials could potentially be used as a suitable excipient for nasal drug delivery, producing consistent aerosol droplet size, and enhanced residence time within the nasal cavity with reduced run-offs compared to conventional polymer thickeners.

Generation of pH responsive fluorescent nano capsules through simple steps for the oral delivery of low pH susceptible drugs

Science.gov (United States)

Radhakumary, Changerath; Sreenivasan, Kunnatheeri

2016-11-01

pH responsive nano capsules are promising as it can encapsulate low pH susceptible drugs like insulin and guard them from the hostile environments in the intestinal tract. The strong acidity of the gastro-intestinal tract and the presence of proteolytic enzymes are the tumbling blocks for the design of drug delivery vehicles through oral route for drugs like insulin. Nano capsules are normally built over templates which are subsequently removed by further steps. Such processes are complex and often lead into deformed and collapsed capsules. In this study, we choose calcium carbonate (CaCO3) nano particles to serve as template. Over CaCO3 nanoparticles, silica layers were built followed by polymethacrylic acid chains to acquire pH responsiveness. During the polymerization process of the methacrylic acid, the calcium carbonate core particles were dissolved leading to the formation of nano hollow capsules having a size that ranges from 225 to 246 nm and thickness from 19 to 58 nm. The methodology is simple and devoid of additional steps. The nano shells exhibited 80% release of the loaded model drug, insulin at pH 7.4 while at pH 2.0 the capsules nearly stopped the release of the drug. Polymethacrylic acid shows pH responsive swelling behavior that it swells at intestinal pH (7.0-7.5) and shrinks at gastric pH (˜2.0) thus enabling the safe unloading of the drug from the nano capsules.

Generation and storage of quantum states using cold atoms

DEFF Research Database (Denmark)

Dantan, Aurelien Romain; Josse, Vincent; Cviklinski, Jean

2006-01-01

Cold cesium or rubidium atomic samples have a good potential both for generation and storage of nonclassical states of light. Generation of nonclassical states of light is possible through the high non-linearity of cold atomic samples excited close to a resonance line. Quadrature squeezing, polar...

Mechanically modulated dewetting by atomic force microscope for micro- and nano- droplet array fabrication.

Science.gov (United States)

Wang, Feifei; Li, Pan; Wang, Dong; Li, Longhai; Xie, Shuangxi; Liu, Lianqing; Wang, Yuechao; Li, Wen Jung

2014-10-06

Organizing a material into well-defined patterns during the dewetting process provides an attractive micro-/nano-fabrication method without using a conventional lithographic process, and hence, offers potential applications in organic electronics, optics systems, and memory devices. We report here how the mechanical modification of polymer surface by an Atomic Force Microscope (AFM) can be used to guide thin film dewetting evolution and break the intrinsic spatial correlation of spontaneous instability. An AFM is used to implement the mechanical modification of progressively narrow grids to investigate the influence of pattern size on the modulation of ultrathin polystyrene films dewetting evolution. For films with different initial thicknesses, when grid size is close to or below the characteristic wavelength of instability, the spinodal dewetting is suppressed, and film rupture is restricted to the cutting trench. We will show in this paper it is possible to generate only one droplet per gridded area on a thin film subsequent to nucleation dominated dewetting on a non-patterned substrate. Furthermore, when the grid periodicity exceeds the spinodal length, the number of droplets in predefined areas gradually approaches that associated with unconfined dewetting.

Carbon nanotubes: from nano test tube to nano-reactor.

Science.gov (United States)

Khlobystov, Andrei N

2011-12-27

Confinement of molecules and atoms inside carbon nanotubes provides a powerful strategy for studying structures and chemical properties of individual molecules at the nanoscale. In this issue of ACS Nano, Allen et al. explore the nanotube as a template leading to the formation of unusual supramolecular and covalent structures. The potential of carbon nanotubes as reactors for synthesis on the nano- and macroscales is discussed in light of recent studies.

Rotary-Atomizer Electric Power Generator

Science.gov (United States)

Nguyen, Trieu; Tran, Tuan; de Boer, Hans; van den Berg, Albert; Eijkel, Jan C. T.

2015-03-01

We report experimental and theoretical results on a ballistic energy-conversion method based on a rotary atomizer working with a droplet acceleration-deceleration cycle. In a rotary atomizer, liquid is fed onto the center of a rotating flat surface, where it spreads out under the action of the centrifugal force and creates "atomized" droplets at its edge. The advantage of using a rotary atomizer is that the centrifugal force exerted on the fluid on a smooth, large surface is not only a robust form of acceleration, as it avoids clogging, but also easily allows high throughput, and produces high electrical power. We successfully demonstrate an output power of 4.9 mW and a high voltage up to 3120 V. At present, the efficiency of the system is still low (0.14%). However, the conversion mechanism of the system is fully interpreted in this paper, permitting a conceptual understanding of system operation and providing a roadmap for system optimization. This observation will open up a road for building power-generation systems in the near future.

Generation of a slow and continuous cesium atomic beam for an atomic clock

International Nuclear Information System (INIS)

Park, Sang Eon; Lee, Ho Seong; Shin, Eun-joo; Kwon, Taeg Yong; Yang, Sung Hoon; Cho, Hyuck

2002-01-01

A thermal atomic beam from a cesium oven was slowed down by use of the Hoffnagle modified white-light cooling technique. In addition, the atomic beam was collimated by use of a two-dimensional optical molasses that was installed transverse to the atomic-beam direction. The flux of the atomic beam was 2x10 10 atoms/s, an increase of a factor of 16 as a result of the collimation. The mean longitudinal velocity was ∼24.4 m/s, and the rms velocity spread of the slowed atomic beam was ∼1 m/s. Compared with other methods, we found that the Hoffnagle method is suitable for the generation of slow atomic beams to be used in an atomic clock, which requires an ultralow magnetic field environment. This atomic beam was deflected by an angle of 30 deg. by a one-dimensional optical molasses to separate it from laser light and high-velocity atoms

High-dimensional atom localization via spontaneously generated coherence in a microwave-driven atomic system.

Science.gov (United States)

Wang, Zhiping; Chen, Jinyu; Yu, Benli

2017-02-20

We investigate the two-dimensional (2D) and three-dimensional (3D) atom localization behaviors via spontaneously generated coherence in a microwave-driven four-level atomic system. Owing to the space-dependent atom-field interaction, it is found that the detecting probability and precision of 2D and 3D atom localization behaviors can be significantly improved via adjusting the system parameters, the phase, amplitude, and initial population distribution. Interestingly, the atom can be localized in volumes that are substantially smaller than a cubic optical wavelength. Our scheme opens a promising way to achieve high-precision and high-efficiency atom localization, which provides some potential applications in high-dimensional atom nanolithography.

Influence of beryllium ceramics nano-structuring by iron atoms on increase of their stability to ionizing radiations effect

International Nuclear Information System (INIS)

Polyakov, A.I.; Bitenbaev, M.I

2007-01-01

In the work a new results on beryllium ceramics nano-structuring effect by iron oxide atoms on radiation defects quantum yield value G in these materials and defects depth constants in ionizing radiation fields k are presented. Experimental data under dependence of G and k values from concentration of iron atoms in beryllium ceramic matrix are presented. It is shown, that structure modification of beryllium ceramics by feedings on the iron base leads to sharp decrease (almost in 30 times) of radiation defects quantum yield value, i.e. to increase of these ceramics stability enhancement to ionizing radiation effect

Cassie state robustness of plasma generated randomly nano-rough surfaces

Energy Technology Data Exchange (ETDEWEB)

Di Mundo, Rosa, E-mail: rosa.dimundo@poliba.it; Bottiglione, Francesco; Carbone, Giuseppe

2014-10-15

Graphical abstract: - Highlights: • Superhydrophobic randomly rough surfaces are generated by plasma etching. • Statistical analysis of roughness allows calculation of theWenzel roughness factor, r{sub W.} • A r{sub W} threshold is theoretically determined, above which superhydrophobicity is “robust”. • Dynamic wetting, e.g. with high speed impacting drops, confirms this prediction. - Abstract: Superhydrophobic surfaces are effective in practical applications provided they are “robust superhydrophobic”, i.e. able to retain the Cassie state, i.e. with water suspended onto the surface protrusions, even under severe conditions (high pressure, vibrations, high speed impact, etc.). We show that for randomly rough surfaces, given the Young angle, Cassie states are robust when a threshold value of the Wenzel roughness factor, r{sub W}, is exceeded. In particular, superhydrophobic nano-textured surfaces have been generated by self-masked plasma etching. In view of their random roughness, topography features, acquired by Atomic Force Microscopy, have been statistically analyzed in order to gain information on statistical parameters such as power spectral density, fractal dimension and Wenzel roughness factor (r{sub W}), which has been used to assess Cassie state robustness. Results indicate that randomly rough surfaces produced by plasma at high power or long treatment duration, which are also fractal self-affine, have a r{sub W} higher than the theoretical threshold, thus for them a robust superhydrophobicity is predicted. In agreement with this, under dynamic wetting conditionson these surfaces the most pronounced superhydrophobic character has been appreciated: they show the lowest contact angle hysteresis and result in the sharpest bouncing when hit by drops at high impact velocity.

Investigating factors influencing consumer willingness to buy GM food and nano-food

International Nuclear Information System (INIS)

Yue, Chengyan; Zhao, Shuoli; Cummings, Christopher; Kuzma, Jennifer

2015-01-01

Emerging technologies applied to food products often evoke controversy about their safety and whether to label foods resulting from their use. As such, it is important to understand the factors that influence consumer desires for labeling and their willingness-to-buy (WTB) these food products. Using data from a national survey with US consumers, this study employs structural equation modeling to explore relationships between potential influences such as trust in government to manage technologies, views on restrictive government policies, perceptions about risks and benefits, and preferences for labeling on consumer’s WTB genetically modified (GM) and nano-food products. Some interesting similarities and differences between GM- and nano-food emerged. For both technologies, trust in governing agencies to manage technologies did not influence labeling preferences, but it did influence attitudes about the food technologies themselves. Attitudes toward the two technologies, as measured by risk–benefit comparisons and comfort with consumption, also greatly influenced views of government restrictive policies, labeling preferences, and WTB GM or nano-food products. For differences, labeling preferences were found to influence WTB nano-foods, but not WTB GM foods. Gender and religiosity also had varying effects on WTB and labeling preferences: while gender and religiosity influenced labeling preferences and WTB for GM foods, they did not have a significant influence for nano-foods. We propose some reasons for these differences, such as greater media attention and other heuristics such as value-based concerns about “modifying life” with GM foods. The results of this study can help to inform policies and communication about the application of these new technologies in food products

Investigating factors influencing consumer willingness to buy GM food and nano-food

Energy Technology Data Exchange (ETDEWEB)

Yue, Chengyan [University of Minnesota-Twin Cities, Departments of Applied Economics and Horticultural Science, Bachman Endowed Chair in Horticultural Marketing (United States); Zhao, Shuoli [University of Minnesota-Twin Cities, Department of Applied Economics (United States); Cummings, Christopher [Nanyang Technological University, Division of Communication Research, Wee Kim Wee School of Communication and Information (Singapore); Kuzma, Jennifer, E-mail: jkuzma@ncsu.edu [North Carolina State University, Genetic Engineering & Society Center (United States)

2015-07-15

Emerging technologies applied to food products often evoke controversy about their safety and whether to label foods resulting from their use. As such, it is important to understand the factors that influence consumer desires for labeling and their willingness-to-buy (WTB) these food products. Using data from a national survey with US consumers, this study employs structural equation modeling to explore relationships between potential influences such as trust in government to manage technologies, views on restrictive government policies, perceptions about risks and benefits, and preferences for labeling on consumer’s WTB genetically modified (GM) and nano-food products. Some interesting similarities and differences between GM- and nano-food emerged. For both technologies, trust in governing agencies to manage technologies did not influence labeling preferences, but it did influence attitudes about the food technologies themselves. Attitudes toward the two technologies, as measured by risk–benefit comparisons and comfort with consumption, also greatly influenced views of government restrictive policies, labeling preferences, and WTB GM or nano-food products. For differences, labeling preferences were found to influence WTB nano-foods, but not WTB GM foods. Gender and religiosity also had varying effects on WTB and labeling preferences: while gender and religiosity influenced labeling preferences and WTB for GM foods, they did not have a significant influence for nano-foods. We propose some reasons for these differences, such as greater media attention and other heuristics such as value-based concerns about “modifying life” with GM foods. The results of this study can help to inform policies and communication about the application of these new technologies in food products.

Investigating factors influencing consumer willingness to buy GM food and nano-food

Science.gov (United States)

Yue, Chengyan; Zhao, Shuoli; Cummings, Christopher; Kuzma, Jennifer

2015-07-01

Emerging technologies applied to food products often evoke controversy about their safety and whether to label foods resulting from their use. As such, it is important to understand the factors that influence consumer desires for labeling and their willingness-to-buy (WTB) these food products. Using data from a national survey with US consumers, this study employs structural equation modeling to explore relationships between potential influences such as trust in government to manage technologies, views on restrictive government policies, perceptions about risks and benefits, and preferences for labeling on consumer's WTB genetically modified (GM) and nano-food products. Some interesting similarities and differences between GM- and nano-food emerged. For both technologies, trust in governing agencies to manage technologies did not influence labeling preferences, but it did influence attitudes about the food technologies themselves. Attitudes toward the two technologies, as measured by risk-benefit comparisons and comfort with consumption, also greatly influenced views of government restrictive policies, labeling preferences, and WTB GM or nano-food products. For differences, labeling preferences were found to influence WTB nano-foods, but not WTB GM foods. Gender and religiosity also had varying effects on WTB and labeling preferences: while gender and religiosity influenced labeling preferences and WTB for GM foods, they did not have a significant influence for nano-foods. We propose some reasons for these differences, such as greater media attention and other heuristics such as value-based concerns about "modifying life" with GM foods. The results of this study can help to inform policies and communication about the application of these new technologies in food products.

[Effect of stability and dissolution of realgar nano-particles using solid dispersion technology].

Science.gov (United States)

Guo, Teng; Shi, Feng; Yang, Gang; Feng, Nian-Ping

2013-09-01

To improve the stability and dissolution of realgar nano-particles by solid dispersion. Using polyethylene glycol 6000 and poloxamer-188 as carriers, the solid dispersions were prepare by melting method. XRD, microscopic inspection were used to determine the status of realgar nano-particles in solid dispersions. The content and stability test of As(2)0(3) were determined by DDC-Ag method. Hydride generation atomic absorption spectrometry was used to determine the content of Arsenic and investigated the in vitro dissolution behavior of solid dispersions. The results of XRD and microscopic inspection showed that realgar nano-particles in solid dispersions were amorphous. The dissolution amount and rate of Arsenic from realgar nano-particles of all solid dispersions were increased significantly, the reunion of realgar nano-particles and content of As(2)0(3) were reduced for the formation of solid dispersions. The solid dispersion of realgar nano-particles with poloxamer-188 as carriers could obviously improve stability, dissolution and solubility.

Evaluation of preparation methods for suspended nano-objects on substrates for dimensional measurements by atomic force microscopy

OpenAIRE

Fiala, Petra; G?hler, Daniel; Wessely, Benno; Stintz, Michael; Lazzerini, Giovanni Mattia; Yacoot, Andrew

2017-01-01

Dimensional measurements on nano-objects by atomic force microscopy (AFM) require samples of safely fixed and well individualized particles with a suitable surface-specific particle number on flat and clean substrates. Several known and proven particle preparation methods, i.e., membrane filtration, drying, rinsing, dip coating as well as electrostatic and thermal precipitation, were performed by means of scanning electron microscopy to examine their suitability for preparing samples for dime...

Managing collaboration in the nanoManipulator

DEFF Research Database (Denmark)

Hudson, Thomas C.; Helser, Aren T.; Sonnenwald, Diane H.

2004-01-01

We designed, developed, deployed, and evaluated the Collaborative nanoManipulator (CnM), a distributed, collaborative virtual environment system supporting remote scientific collaboration between users of the nanoManipulator interface to atomic force microscopes. This paper describes the entire...

Quantitative analysis of supported membrane composition using the NanoSIMS

Energy Technology Data Exchange (ETDEWEB)

Kraft, M L; Fishel, S F; Marxer, C G; Weber, P K; Hutcheon, I D; Boxer, S G

2009-06-02

We have improved methods reported earlier [1] for sample preparation, imaging and quantifying components in supported lipid bilayers using high-resolution secondary ion mass spectrometry performed with the NanoSIMS 50. By selectively incorporating a unique stable isotope into each component of interest, a component-specific image is generated from the location and intensity of the unique secondary ion signals exclusively produced by each molecule. Homogeneous supported lipid bilayers that systematically varied in their isotopic enrichment levels were freeze-dried and analyzed with the NanoSIMS 50. The molecule-specific secondary ion signal intensities had an excellent linear correlation to the isotopically labeled lipid content. Statistically indistinguishable calibration curves were obtained using different sample sets analyzed months apart. Fluid bilayers can be patterned using lithographic methods and the composition of each corralled region varied systematically by simple microfluidic methods. The resulting composition variations can be imaged and quantified. This approach opens the possibility of imaging and quantifying the composition of microdomains within membranes, including protein components, without using bulky labels and with very high lateral resolution and sensitivity.

Generation of atomic iodine via fluorine for chemical oxygen-iodine laser

International Nuclear Information System (INIS)

Jirasek, Vit; Spalek, Otomar; Censky, Miroslav; Pickova, Irena; Kodymova, Jarmila; Jakubec, Ivo

2007-01-01

A method of the chemical generation of atomic iodine for a chemical oxygen-iodine laser (COIL) using atomic fluorine as a reaction intermediate was studied experimentally. This method is based on the reaction between F 2 and NO providing F atoms, and the reaction of F with HI resulting in iodine atoms generation. Atomic iodine was produced with efficiency exceeding 40% relative to initial F 2 flow rate. This efficiency was nearly independent on pressure and total gas flow rate. The F atoms were stable in the reactor up to 2 ms. An optimum ratio of the reactants flow rates was F 2 :NO:HI = 1:1:1. A rate constant of the reaction of F 2 with HI was determined. The numerical modelling showed that remaining HI and IF were probably consumed in their mutual reaction. The reaction system was found suitable for employing in a generator of atomic iodine with its subsequent injection into a supersonic nozzle of a COIL

Book Review: Nano physics & Nano technology

Directory of Open Access Journals (Sweden)

Abdolkhaled Zaree

2012-12-01

Full Text Available During last decades, there are a lot of emphases on studying material behavior in atomic scale. In most scientific and engineering fields, one can see the effect of nanotechnology. The aim of nanoscience is to design and fabrication of new and applicable materials. Nowadays, Nano is a popular science which chemists, physicist, doctors, engineers, financial managers and environment's fans for creating a good life via nanoscience have a great cooperation with each others. Materials in nano scale such as nanotubes and nanowires have extraordinary properties which by optimization of these properties in nano scale and then develop these properties to macro scale, they've been challenging issues. For instance, materials in nano scale improve mechanical properties of polymers and metallic materials via nano particles and on the other hand by producing a thin film on surfaces improve surface hardening. Besides, nanotechnology is in hi-tech industries such as magnetic devices, surface coating, and biomaterial, material having sensors, polymers, gels, ceramics and intelligent membrane. Nano-carbon tubes are considered intelligent due to the fact that they couple electrochemical and elastic properties simultaneously, hence have greater activation energy density in comparison with other intelligent materials. Studying nanoscience is important because it causes the life to be better. Future Materials and structures will have a lot of outstanding properties. Intelligent machines can repair, recycle and reconstruct themselves. All these features are only possible in nano zone. Nano in engineering science can provide the possibility of making light missiles for exploring space. The reduced weight can be achieved by replacing traditional materials with hybrid nanocomposites.

Simultaneous determination of arsenic and antimony by hydride generation atomic fluorescence spectrometry with dielectric barrier discharge atomizer

Energy Technology Data Exchange (ETDEWEB)

Xing Zhi [Department of Chemistry, Key Laboratory for Atomic and Molecular Nanosciences of the Education Ministry, Tsinghua University, Beijing 100084 (China); Kuermaiti, Biekesailike [Department of Chemistry, Key Laboratory for Atomic and Molecular Nanosciences of the Education Ministry, Tsinghua University, Beijing 100084 (China); Products Quality Inspection Institute, Yili, Xinjiang 835000 (China); Wang Juan; Han Guojun; Zhang Sichun [Department of Chemistry, Key Laboratory for Atomic and Molecular Nanosciences of the Education Ministry, Tsinghua University, Beijing 100084 (China); Zhang Xinrong, E-mail: xrzhang@mail.tsinghua.edu.cn [Department of Chemistry, Key Laboratory for Atomic and Molecular Nanosciences of the Education Ministry, Tsinghua University, Beijing 100084 (China)

2010-12-15

Simultaneous determination of As and Sb by hydride generation atomic fluorescence spectrometry was developed with the dielectric barrier discharge plasma as the hydride atomizer. The low-temperature and atmospheric-pressure micro-plasma was generated in a quartz cylindrical configuration device, which was constructed by an axial internal electrode and an outer electrode surrounding outside of the tube. The optimization of the atomizer construction and parameters for hydride generation and fluorescence detection systems were carried out. Under the optimized conditions, the detection limits for As and Sb were 0.04 and 0.05 {mu}g L{sup -1}, respectively. In addition, the applicability of the present method was confirmed by the detection of As and Sb in reference materials of quartz sandstone (GBW07106) and argillaceous limestone (GBW07108). The present work provided a new approach to exploit the miniaturized hydride generation dielectric barrier discharge atomic fluorescence spectrometry system for simultaneous multi-element determination.

Simultaneous determination of arsenic and antimony by hydride generation atomic fluorescence spectrometry with dielectric barrier discharge atomizer

International Nuclear Information System (INIS)

Xing Zhi; Kuermaiti, Biekesailike; Wang Juan; Han Guojun; Zhang Sichun; Zhang Xinrong

2010-01-01

Simultaneous determination of As and Sb by hydride generation atomic fluorescence spectrometry was developed with the dielectric barrier discharge plasma as the hydride atomizer. The low-temperature and atmospheric-pressure micro-plasma was generated in a quartz cylindrical configuration device, which was constructed by an axial internal electrode and an outer electrode surrounding outside of the tube. The optimization of the atomizer construction and parameters for hydride generation and fluorescence detection systems were carried out. Under the optimized conditions, the detection limits for As and Sb were 0.04 and 0.05 μg L -1 , respectively. In addition, the applicability of the present method was confirmed by the detection of As and Sb in reference materials of quartz sandstone (GBW07106) and argillaceous limestone (GBW07108). The present work provided a new approach to exploit the miniaturized hydride generation dielectric barrier discharge atomic fluorescence spectrometry system for simultaneous multi-element determination.

On rings generating supernilpotent and special atoms | France ...

African Journals Online (AJOL)

We study prime rings which generate supernilpotent (respectively special) atoms, that is, atoms of the lattice of all supernilpotent (respectively special) radicals. A prime ring A is called a **-ring if the smallest special class containing A is closed under semiprime homomorphic images of A. A semiprime ring A whose every ...

Hybrid reflection type metasurface of nano-antennas designed for optical needle field generation

Science.gov (United States)

Wang, Shiyi; Zhan, Qiwen

2015-03-01

We propose a reflection type metal-insulator-metal (MIM) metasurface composed of hybrid optical antennas for comprehensive spatial engineering the properties of optical fields. Its capability is illustrated with an example to create a radially polarized vectorial beam for optical needle field generation. Functioning as local quarter-wave-plates (QWP), the MIM metasurface is designed to convert circularly polarized incident into local linear polarization to create an overall radial polarization with corresponding binary phases and desired normalized amplitude modulation ranged from 0.07 to 1. To obtain enough degrees of freedom, the optical-antenna layer comprises periodic arrangements of double metallic nano-bars with perpendicular placement and single nano-bars respectively for different amplitude modulation requirements. Both of the antennas enable to introduce π/2 retardation while reaching the desired modulation range both for phase and amplitude. Through adjusting the antennas' geometry and array carefully, we shift the gap-surface plasmon resonances facilitated by optical antennas to realize the manipulation of vectorial properties. Designed at 1064 nm wavelength, the particularly generated vectorial light output can be further tightly focused by a high numerical aperture objective to obtain longitudinally polarized flat-top focal field. The so-called optical needle field is a promising candidate for novel applications that transcend disciplinary boundaries. The proposed metasurface establishes a new class of compact optical components based on nano-scale structures, leading to compound functions for vectorial light generation.

Multiple optical code-label processing using multi-wavelength frequency comb generator and multi-port optical spectrum synthesizer.

Science.gov (United States)

Moritsuka, Fumi; Wada, Naoya; Sakamoto, Takahide; Kawanishi, Tetsuya; Komai, Yuki; Anzai, Shimako; Izutsu, Masayuki; Kodate, Kashiko

2007-06-11

In optical packet switching (OPS) and optical code division multiple access (OCDMA) systems, label generation and processing are key technologies. Recently, several label processors have been proposed and demonstrated. However, in order to recognize N different labels, N separate devices are required. Here, we propose and experimentally demonstrate a large-scale, multiple optical code (OC)-label generation and processing technology based on multi-port, a fully tunable optical spectrum synthesizer (OSS) and a multi-wavelength electro-optic frequency comb generator. The OSS can generate 80 different OC-labels simultaneously and can perform 80-parallel matched filtering. We also demonstrated its application to OCDMA.

Compaction simulation of nano-crystalline metals with molecular dynamics analysis

Directory of Open Access Journals (Sweden)

Khoei A.R.

2016-01-01

Full Text Available The molecular-dynamics analysis is presented for 3D compaction simulation of nano-crystalline metals under uniaxial compaction process. The nano-crystalline metals consist of nickel and aluminum nano-particles, which are mixed with specified proportions. The EAM pair-potential is employed to model the formation of nano-particles at different temperatures, number of nano-particles, and mixing ratio of Ni and Al nano-particles to form the component into the shape of a die. The die-walls are modeled using the Lennard-Jones inter-atomic potential between the atoms of nano-particles and die-walls. The forming process is model in uniaxial compression, which is simulated until the full-dense condition is attained at constant temperature. Numerical simulations are performed by presenting the densification of nano-particles at different deformations and distribution of dislocations. Finally, the evolutions of relative density with the pressure as well as the stress-strain curves are depicted during the compaction process.

Multi-walled carbon nano-tubes for energy storage and production applications

International Nuclear Information System (INIS)

Andrews, R.; Jacques, D.; Likpa, S.; Qian, D.; Rantell, T.; Anthony, J.

2005-01-01

Full text of publication follows: Since their discovery, carbon nano-tubes have been proposed as candidate materials for a broad range of applications, including high strength composites, molecular electronics, and energy storage. In many cases, nano-tubes have been proposed to replace traditional carbon materials, such as activated carbons in energy storage devices. In other cases, novel applications have been proposed, such as the use of carbon nano-tube arrays in photovoltaic devices. The use of multi-walled carbon nano-tubes in energy storage devices has generated great interest due to their high inherent conductivity, layered structure, and high surface area per volume compared to traditional graphitic materials. However as produced nano-tubes do not possess ideal properties, and exhibit only modest charge storage. We have explored the charge storage abilities of nano-tubes with varying morphologies (fullerenic versus stacked cones), nano-tubes containing N or B dopants, as well as various post-treatments of the nano-tubes. The use of nano-tubes in charge storage devices will be described, as well as modification of the nano-tube surfaces or morphology to improve this performance. The synthesis of nano-tubes with several differing hetero-atom dopants will also be described, as well as the effect of heat treatment on these structures. One of the most significant problems in organic photovoltaics is the typically low charge-carrier mobility in organic thin films which, coupled with short exciton diffusion lengths, means that photo-generated charge-carrier pairs are more likely to re-combine than reach an electrode to generate current. Two organic systems with high charge-carrier mobilities are carbon nano-tubes (here, MWNTs) and acene-based organic semiconductors. We believe that blended devices based on MWNTs and organic semiconductors could lead to the next class of efficient, flexible and inexpensive organic photovoltaic systems. We have developed methods to

Generation of micro- and nano-droplets containing immiscible solutions in view of optical studies

Science.gov (United States)

Nastasa, V.; Karapantsios, T.; Samaras, K.; Dafnopatidou, E.; Pradines, V.; Miller, R.; Pascu, M. L.

2010-08-01

The multiple resistances to treatment, developed by bacteria and malignant tumors require finding alternatives to the existing medicines and treatment procedures. One of them is strengthening the effects of cytostatics by improving the delivery method. Such a method is represented by the use of medicines as micro/nano-droplets. This method can reduce the substance consumption by generating drug micro-droplets incorporated in substances that can favour a faster localization, than the classical mode of medicine administration, to the tumor tissues. This paper contains the results concerning the generation and study of micro/nano-droplets and the generation of micro-droplets with an inner core (medicine) and a thin layer covering it. We have measured the surface tension at water/air interface and water/oil interface for a medicine (Vancomycin) and we have generated and measured droplets of medicine containing a layer of Vitamin A by using a double capillary system. The micro/nano-droplets may be produced by mixing of two immiscible solutions in particular conditions (high rotating speed and/or high pressure difference). For this we have studied the generation of emulsions of vitamin A diluted in sunflower oil and a solution of a surfactant Tween 80 in distilled water. The concentration of surfactant in water was typically 4*10-5M. We have studied in a batch stirred tank system the dependence of the droplet dimensions in emulsion, function of the mixing rotation speed, agitation time and components ratio. The droplet diameters were measured using a Malvern light scattering instrument type Mastersizer Hydro 2000M. We have obtained droplets with diameters smaller than 100 nm; the diameters distribution exhibited a peak at 65 nm.

Labeling capability of the eluent of gel-type 99Mo-99mTc generator

International Nuclear Information System (INIS)

Wu Xiuduo; Zhang Jingu

1995-01-01

The results of more than 7909 imaging of various organs which have been carried out on domestic gel-type 99 Mo- 99m Tc generators in the last seven years are presented. In all the 220 times of determination for the radiochemical purity of a portion of imaging agents, there were 15 times in which the labeling efficiency was lower than 90% and only 3 times in which the radiolabeling failed. In comparison with labeling capability of nuclear fission generators, it is showed that there are no evident differences between the eluent's labeling efficiency of the two kinds of generators

Crystal engineering of giant molecules based on perylene diimide conjugated polyhedral oligomeric silsesquioxane nano-atom

Science.gov (United States)

Ren, He

Molecular architectures and topologies are found contributing to the formation of supramolecular structures of giant molecules. Dr. Cheng's research group developed a diverse of giant molecules via precisely controlled chemistry synthetic routes. These giant molecules can be categorized into several different families, namely giant surfactants, giant shape amphiphiles and giant polyhedron. By analyzing the hierarchical structures of these carefully designed and precisely synthesized giant molecules, the structural factors which affect, or even dominates, in some cases, the formation of supramolecular structures are revealed in these intensive researches. The results will further contribute to the understanding of dependence of supramolecular structures on molecular designs as well as molecular topology, and providing a practical solution to the scaling up of microscopic molecular functionalities to macroscopic material properties. Molecular Nano Particles (MNPs), including fullerene (C60), POSS, Polyoxometalate (POM) and proteins etc., is defined and applied as a specific type of building blocks in the design and synthesis of giant molecules. The persistence in shape and symmetry is considered as one of the major properties of MNPs. This persistence will support the construction of giant molecules for further supramolecular structures' study by introducing specific shapes, or precisely located side groups which will facilitate self-assembling behaviors with pre-programmed secondary interactions. Dictating material physical properties by its chemical composition is an attractive yet currently failed approach in the study of materials. However, the pursuit of determining material properties by microscopic molecular level properties is never seized, and found its solution when the idea of crystal engineering is raised: should each atom in the material is located exactly where it is designed to be and is properly bonded, the property of the material is hence determined

Vapor generation and atom traps: Atomic absorption spectrometry at the ng/L level

International Nuclear Information System (INIS)

Ataman, O. Yavuz

2008-01-01

Atom-trapping atomic absorption spectrometry is a technique that allows detection at the ng/L level for several analytes such as As, Se, Sb, Pb, Bi, Cd, In, Tl, Te, Sn and Hg. The principle involves generation of volatile species, usually hydrides, trapping these species on the surface of an atom trap held at an optimized temperature and, finally, revolatilizing the analyte species by rapid heating of the trap and transporting them in a carrier gas to a heated quartz tube, as commonly used with hydride generation AAS systems. A transient signal having, in most cases, a full width at half maximum of less than 1 s is obtained. The atom trap may be a quartz surface or a W-coil; the former is heated externally and the latter is heated resistively. Both collection and revolatilization temperatures are optimized. In some cases, the W-coil itself is used as an electrothermal atomizer and a heated quartz tube is then not needed. The evolution of these traps starts with the well-known Watling's slotted quartz tube (SQT), continues with atom trapping SQT and finally reaches the present traps mentioned above. The analytical figures of merit for these traps need to be standardized. Naturally, enhancement is on characteristic concentration, C 0 , where the change in characteristic mass, m 0 , can be related to trapping efficiency. Novel terms are suggested for E, enhancement factor; such as E max , maximum enhancement factor; E t , enhancement for 1.0 minute sampling and E v , enhancement for 1.0 mL of sample. These figures will allow easy comparison of results from different laboratories as well as different analytes and/or traps

Recent Development of Nano-Materials Used in DNA Biosensors

Directory of Open Access Journals (Sweden)

Yibin Ying

2009-07-01

Full Text Available As knowledge of the structure and function of nucleic acid molecules has increased, sequence-specific DNA detection has gained increased importance. DNA biosensors based on nucleic acid hybridization have been actively developed because of their specificity, speed, portability, and low cost. Recently, there has been considerable interest in using nano-materials for DNA biosensors. Because of their high surface-to-volume ratios and excellent biological compatibilities, nano-materials could be used to increase the amount of DNA immobilization; moreover, DNA bound to nano-materials can maintain its biological activity. Alternatively, signal amplification by labeling a targeted analyte with nano-materials has also been reported for DNA biosensors in many papers. This review summarizes the applications of various nano-materials for DNA biosensors during past five years. We found that nano-materials of small sizes were advantageous as substrates for DNA attachment or as labels for signal amplification; and use of two or more types of nano-materials in the biosensors could improve their overall quality and to overcome the deficiencies of the individual nano-components. Most current DNA biosensors require the use of polymerase chain reaction (PCR in their protocols. However, further development of nano-materials with smaller size and/or with improved biological and chemical properties would substantially enhance the accuracy, selectivity and sensitivity of DNA biosensors. Thus, DNA biosensors without PCR amplification may become a reality in the foreseeable future.

Detecting molecules and cells labeled with magnetic particles using an atomic magnetometer

International Nuclear Information System (INIS)

Yu Dindi; Ruangchaithaweesuk, Songtham; Yao Li; Xu Shoujun

2012-01-01

The detection of magnetically labeled molecules and cells involves three essential parameters: sensitivity, spatial resolution, and molecular specificity. We report on the use of atomic magnetometry and its derivative techniques to achieve high performance in terms of all these parameters. With a sensitivity of 80 fT/√Hz for dc magnetic fields, we show that 7,000 streptavidin-conjugated magnetic microparticles magnetized by a permanent magnet produce a magnetic field of 650 pT; this result predicts that a single such particle can be detected during one second of signal averaging. Spatial information is obtained using a scanning magnetic imaging scheme. The spatial resolution is 20 μm with a detection distance of more than 1 cm; this distance is much longer than that in previous reports. The molecular specificity is achieved using force-induced remnant magnetization spectroscopy, which currently uses an atomic magnetometer for detection. As an example, we perform measurement of magnetically labeled human CD4+ T cells, whose count in the blood is the diagnostic criterion for human immunodeficiency virus infection. Magnetic particles that are specifically bound to the cells are resolved from nonspecifically bound particles and quantitatively correlate with the number of cells. The magnetic particles have an overall size of 2.8 μm, with a magnetic core in nanometer regime. The combination of our techniques is predicted to be useful in molecular and cellular imaging.

Detecting molecules and cells labeled with magnetic particles using an atomic magnetometer

Energy Technology Data Exchange (ETDEWEB)

Yu Dindi; Ruangchaithaweesuk, Songtham; Yao Li; Xu Shoujun, E-mail: sxu7@uh.edu [University of Houston, Department of Chemistry (United States)

2012-09-15

The detection of magnetically labeled molecules and cells involves three essential parameters: sensitivity, spatial resolution, and molecular specificity. We report on the use of atomic magnetometry and its derivative techniques to achieve high performance in terms of all these parameters. With a sensitivity of 80 fT/{radical}Hz for dc magnetic fields, we show that 7,000 streptavidin-conjugated magnetic microparticles magnetized by a permanent magnet produce a magnetic field of 650 pT; this result predicts that a single such particle can be detected during one second of signal averaging. Spatial information is obtained using a scanning magnetic imaging scheme. The spatial resolution is 20 {mu}m with a detection distance of more than 1 cm; this distance is much longer than that in previous reports. The molecular specificity is achieved using force-induced remnant magnetization spectroscopy, which currently uses an atomic magnetometer for detection. As an example, we perform measurement of magnetically labeled human CD4+ T cells, whose count in the blood is the diagnostic criterion for human immunodeficiency virus infection. Magnetic particles that are specifically bound to the cells are resolved from nonspecifically bound particles and quantitatively correlate with the number of cells. The magnetic particles have an overall size of 2.8 {mu}m, with a magnetic core in nanometer regime. The combination of our techniques is predicted to be useful in molecular and cellular imaging.

Generation of Bell, NOON and W states via atom interferometry

Energy Technology Data Exchange (ETDEWEB)

Islam, Rameez-ul; Saif, Farhan [Department of Electronics, Quaid-i-Azam University, Islamabad (Pakistan); Khosa, Ashfaq H [Centre for Quantum Physics, COMSATS Institute of Information Technology, Islamabad (Pakistan)

2008-02-14

We propose atom interferometric techniques for the generation of Bell, NOON and W states of an electromagnetic field in high-Q cavities. The fundamental constituent of these techniques is off-resonant Bragg diffraction of atomic de Broglie waves. We show good success probabilities for these schemes under the currently available experimental environment of atom interferometry.

Developments towards in-gas-jet laser spectroscopy studies of actinium isotopes at LISOL

International Nuclear Information System (INIS)

Raeder, S.; Bastin, B.; Block, M.; Creemers, P.; Delahaye, P.; Ferrer, R.; Fléchard, X.; Franchoo, S.; Ghys, L.; Gaffney, L.P.; Granados, C.; Heinke, R.; Hijazi, L.

2016-01-01

To study exotic nuclides at the borders of stability with laser ionization and spectroscopy techniques, highest efficiencies in combination with a high spectral resolution are required. These usually opposing requirements are reconciled by applying the in-gas-laser ionization and spectroscopy (IGLIS) technique in the supersonic gas jet produced by a de Laval nozzle installed at the exit of the stopping gas cell. Carrying out laser ionization in the low-temperature and low density supersonic gas jet eliminates pressure broadening, which will significantly improve the spectral resolution. This article presents the required modifications at the Leuven Isotope Separator On-Line (LISOL) facility that are needed for the first on-line studies of in-gas-jet laser spectroscopy. Different geometries for the gas outlet and extraction ion guides have been tested for their performance regarding the acceptance of laser ionized species as well as for their differential pumping capacities. The specifications and performance of the temporarily installed high repetition rate laser system, including a narrow bandwidth injection-locked Ti:sapphire laser, are discussed and first preliminary results on neutron-deficient actinium isotopes are presented indicating the high capability of this novel technique.

Developments towards in-gas-jet laser spectroscopy studies of actinium isotopes at LISOL

Energy Technology Data Exchange (ETDEWEB)

Raeder, S., E-mail: s.raeder@gsi.de [KU Leuven, Instituut voor Kern- en Stralingsfysica, Celestijnenlaan 200D, B-3001 Leuven (Belgium); Helmholtz-Institut Mainz, 55128 Mainz (Germany); GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstraße 1, 64291 Darmstadt (Germany); Bastin, B. [GANIL, CEA/DSM-CNRS/IN2P3, B.P. 55027, 14076 Caen (France); Block, M. [Helmholtz-Institut Mainz, 55128 Mainz (Germany); GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstraße 1, 64291 Darmstadt (Germany); Institut für Kernchemie, Johannes Gutenberg Universität, 55128 Mainz (Germany); Creemers, P. [KU Leuven, Instituut voor Kern- en Stralingsfysica, Celestijnenlaan 200D, B-3001 Leuven (Belgium); Delahaye, P. [GANIL, CEA/DSM-CNRS/IN2P3, B.P. 55027, 14076 Caen (France); Ferrer, R. [KU Leuven, Instituut voor Kern- en Stralingsfysica, Celestijnenlaan 200D, B-3001 Leuven (Belgium); Fléchard, X. [LPC Caen, ENSICAEN, Université de Caen, CNRS/IN2P3, Caen (France); Franchoo, S. [Institute de Physique Nucléaire (IPN) d’Orsay, 91406 Orsay, Cedex (France); Ghys, L. [KU Leuven, Instituut voor Kern- en Stralingsfysica, Celestijnenlaan 200D, B-3001 Leuven (Belgium); SCK-CEN, Belgian Nuclear Research Center, Boeretang 200, 2400 Mol (Belgium); Gaffney, L.P.; Granados, C. [KU Leuven, Instituut voor Kern- en Stralingsfysica, Celestijnenlaan 200D, B-3001 Leuven (Belgium); Heinke, R. [Institut für Physik, Johannes Gutenberg Universität, 55128 Mainz (Germany); Hijazi, L. [GANIL, CEA/DSM-CNRS/IN2P3, B.P. 55027, 14076 Caen (France); and others

2016-06-01

To study exotic nuclides at the borders of stability with laser ionization and spectroscopy techniques, highest efficiencies in combination with a high spectral resolution are required. These usually opposing requirements are reconciled by applying the in-gas-laser ionization and spectroscopy (IGLIS) technique in the supersonic gas jet produced by a de Laval nozzle installed at the exit of the stopping gas cell. Carrying out laser ionization in the low-temperature and low density supersonic gas jet eliminates pressure broadening, which will significantly improve the spectral resolution. This article presents the required modifications at the Leuven Isotope Separator On-Line (LISOL) facility that are needed for the first on-line studies of in-gas-jet laser spectroscopy. Different geometries for the gas outlet and extraction ion guides have been tested for their performance regarding the acceptance of laser ionized species as well as for their differential pumping capacities. The specifications and performance of the temporarily installed high repetition rate laser system, including a narrow bandwidth injection-locked Ti:sapphire laser, are discussed and first preliminary results on neutron-deficient actinium isotopes are presented indicating the high capability of this novel technique.

Detection of magnetic-labeled antibody specific recognition events by combined atomic force and magnetic force microscopy

International Nuclear Information System (INIS)

Hong Xia; Liu Yanmei; Li Jun; Guo Wei; Bai Yubai

2009-01-01

Atomic force (AFM) and magnetic force microscopy (MFM) were developed to detect biomolecular specific interaction. Goat anti-mouse immunoglobulin (anti-IgG) was covalently attached onto gold substrate modified by a self-assembly monolayer of thioctic acid via 1-ethyl-3-[3-(dimethylamino) propyl] carbodiimide (EDC) activation. Magnetic-labeled IgG then specifically adsorbed onto anti-IgG surface. The morphological variation was identified by AFM. MFM was proved to be a fine assistant tool to distinguish the immunorecognized nanocomposites from the impurities by detection of the magnetic signal from magnetic-labeled IgG. It would enhance the understanding of biomolecular recognition process.

Detection of magnetic-labeled antibody specific recognition events by combined atomic force and magnetic force microscopy

Energy Technology Data Exchange (ETDEWEB)

Hong Xia [Center for Advanced Optoelectronic Functional Materials Research, Key Laboratory of UV Light-Emitting Materials and Technology, Ministry of Education, Northeast Normal University, Changchun 130024 (China); College of Chemistry, Jilin University, Changchun 130023 (China)], E-mail: xiahong@nenu.edu.cn; Liu Yanmei; Li Jun; Guo Wei; Bai Yubai [College of Chemistry, Jilin University, Changchun 130023 (China)

2009-09-15

Atomic force (AFM) and magnetic force microscopy (MFM) were developed to detect biomolecular specific interaction. Goat anti-mouse immunoglobulin (anti-IgG) was covalently attached onto gold substrate modified by a self-assembly monolayer of thioctic acid via 1-ethyl-3-[3-(dimethylamino) propyl] carbodiimide (EDC) activation. Magnetic-labeled IgG then specifically adsorbed onto anti-IgG surface. The morphological variation was identified by AFM. MFM was proved to be a fine assistant tool to distinguish the immunorecognized nanocomposites from the impurities by detection of the magnetic signal from magnetic-labeled IgG. It would enhance the understanding of biomolecular recognition process.

Vapor generation and atom traps: Atomic absorption spectrometry at the ng/L level

Energy Technology Data Exchange (ETDEWEB)

Ataman, O. Yavuz [Department of Chemistry, Middle East Technical University, 06531 Ankara (Turkey)], E-mail: ataman@metu.edu.tr

2008-08-15

Atom-trapping atomic absorption spectrometry is a technique that allows detection at the ng/L level for several analytes such as As, Se, Sb, Pb, Bi, Cd, In, Tl, Te, Sn and Hg. The principle involves generation of volatile species, usually hydrides, trapping these species on the surface of an atom trap held at an optimized temperature and, finally, revolatilizing the analyte species by rapid heating of the trap and transporting them in a carrier gas to a heated quartz tube, as commonly used with hydride generation AAS systems. A transient signal having, in most cases, a full width at half maximum of less than 1 s is obtained. The atom trap may be a quartz surface or a W-coil; the former is heated externally and the latter is heated resistively. Both collection and revolatilization temperatures are optimized. In some cases, the W-coil itself is used as an electrothermal atomizer and a heated quartz tube is then not needed. The evolution of these traps starts with the well-known Watling's slotted quartz tube (SQT), continues with atom trapping SQT and finally reaches the present traps mentioned above. The analytical figures of merit for these traps need to be standardized. Naturally, enhancement is on characteristic concentration, C{sub 0}, where the change in characteristic mass, m{sub 0}, can be related to trapping efficiency. Novel terms are suggested for E, enhancement factor; such as E{sub max}, maximum enhancement factor; E{sub t}, enhancement for 1.0 minute sampling and E{sub v}, enhancement for 1.0 mL of sample. These figures will allow easy comparison of results from different laboratories as well as different analytes and/or traps.

Spatially confined synthesis of SiOx nano-rod with size-controlled Si quantum dots in nano-porous anodic aluminum oxide membrane.

Science.gov (United States)

Pai, Yi-Hao; Lin, Gong-Ru

2011-01-17

By depositing Si-rich SiOx nano-rod in nano-porous anodic aluminum oxide (AAO) membrane using PECVD, the spatially confined synthesis of Si quantum-dots (Si-QDs) with ultra-bright photoluminescence spectra are demonstrated after low-temperature annealing. Spatially confined SiOx nano-rod in nano-porous AAO membrane greatly increases the density of nucleated positions for Si-QD precursors, which essentially impedes the route of thermally diffused Si atoms and confines the degree of atomic self-aggregation. The diffusion controlled growth mechanism is employed to determine the activation energy of 6.284 kJ mole(-1) and diffusion length of 2.84 nm for SiO1.5 nano-rod in nano-porous AAO membrane. HRTEM results verify that the reduced geometric dimension of the SiOx host matrix effectively constrain the buried Si-QD size at even lower annealing temperature. The spatially confined synthesis of Si-QD essentially contributes the intense PL with its spectral linewidth shrinking from 210 to 140 nm and its peak intensity enhancing by two orders of magnitude, corresponding to the reduction on both the average Si-QD size and its standard deviation from 2.6 to 2.0 nm and from 25% to 12.5%, respectively. The red-shifted PL wavelength of the Si-QD reveals an inverse exponential trend with increasing temperature of annealing, which is in good agree with the Si-QD size simulation via the atomic diffusion theory.

Synthesis of deuterium-labeled fluphenazine.

Science.gov (United States)

Shetty, H U; Hawes, E M; Midha, K K

1984-01-01

The propylpiperazine side chain of fluphenazine has been labeled with two, four, and six deuterium atoms by lithium aluminum deuteride reduction of the appropriate ester or imide. The gamma-carbon of the propyl group was labeled with two deuterium atoms by reduction of 10- (2-methoxycarbonylethyl) -2-trifluoromethyl-10H-phenothiazine, while four deuterium atoms were incorporated into the piperazine ring by reduction of 10-[3-(3,5-dioxo-1-piperazinyl)propyl]-2-trifluoromethyl-10H-pheno thiazine. The latter reduction gave the d4-labeled N-deshydroxyethyl metabolite of fluphenazine.

Synthesis, fabrication, and spectroscopy of nano-scale photonic noble metal materials

Science.gov (United States)

Egusa, Shunji

Nanometer is an interesting scale for physicists, chemists, and materials scientists, in a sense that it lies between the macroscopic and the atomic scales. In this regime, materials exhibit distinct physical and chemical properties that are clearly different from those of atoms or macroscopic bulk. This thesis is concerned about both physics and chemistry of noble metal nano-structures. Novel chemical syntheses and physical fabrications of various noble metal nano-structures, and the development of spectroscopic techniques for nano-structures are presented. Scanning microscopy/spectroscopy techniques inherently perturbs the true optical responses of the nano-structures. However, by using scanning tunneling microscope (STM) tip as the nanometer-confined excitation source of surface plasmons in the samples, and subsequently collecting the signals in the Fourier space, it is shown that the tip-perturbed part of the signals can be deconvoluted. As a result, the collected signal in this approach is the pure response of the sample. Coherent light is employed to study the optical response of nano-structures, in order to avoid complication from tip-perturbation as discussed above. White-light super-continuum excites the nano-structure, the monolayer of Au nanoparticles self-assembled on silicon nitride membrane substrates. The coherent excitation reveals asymmetric surface plasmon resonance in the nano-structures. One of the most important issues in nano-scale science is to gain control over the shape, size, and assembly of nanoparticles. A novel method is developed to chemically synthesize ligand-passivated atomic noble metal clusters in solution phase. The method, named thermal decomposition method, enables facile yet robust synthesis of fluorescent atomic clusters. Thus synthesized atomic clusters are very stable, and show behaviors of quantum dots. A novel and versatile approach for creation of nanoparticle arrays is developed. This method is different from the

Milking technique of sup(99m)Tc generators and labeling efficiencies

International Nuclear Information System (INIS)

Salehi, N.; Guignard, P.A.

1985-01-01

Increased levels of 99 Tc in generator produced sup(99m)Tc have an adverse effect on the labelling efficiency of red blood cells and human serum albumin. A two-step milking technique in which the first 1-2 ml of eluate is discarded has been found to produce higher and more constant labelling efficiency of lymphocytes and platelets than a one-step procedure. Binding efficiency of platelet-rich plasma and lymphocytes with sup(99m)Tc is greater in the two-step technique. High activity concentration in the eluate for critical labelling is between 1.5-3 ml. (U.K.)

A reagentless amperometric immunosensor based on nano-au and ...

African Journals Online (AJOL)

In this paper, carboxyl-ferrocene (Fc-COOH) was explored to label alphafetoprotein antibody (anti-AFP), which was then mixed with AU nanoparticles (nano-Au) and multi-walled carbon nanotubes (MWCNTs) dispersed by chitosan (CS) to form the nano-Au/MWCNTs/anti-AFP-Fc chitosan composite. After that, the composite ...

Nano structures for Medical Diagnostics Md

International Nuclear Information System (INIS)

Bellah, M.; Iqbal, S.M.; Bellah, M.; Iqbal, S.M.; Christensen, S.M.; Iqbal, S.M.; Iqbal, S.M.

2012-01-01

Nano technology is the art of manipulating materials on atomic or molecular scales especially to build nano scale structures and devices. The field is expanding quickly, and a lot of work is ongoing in the design, characterization, synthesis, and application of materials, structures, devices, and systems by controlling shape and size at nanometer scale. In the last few years, much work has been focused on the use of nano structures toward problems of biology and medicine. In this paper, we focus on the application of various nano structures and nano devices in clinical diagnostics and detection of important biological molecules. The discussion starts by introducing some basic techniques of micro-/nano scale fabrication that have enabled reproducible production of nano structures. The prospects, benefits, and limitations of using these novel techniques in the fields of bio detection and medical diagnostics are then discussed. Finally, the challenges of mass production and acceptance of nano technology by the medical community are considered.

Progress in Nano-Electro-Optics III Industrial Applications and Dynamics of the Nano-Optical System

CERN Document Server

Ohtsu, Motoichi

2005-01-01

This unique monograph series "Progress in Nano-Electro Optics" reviews the results of advanced studies of electro-optics on the nanometric scale. This third volume covers the most recent topics of theoretical and experimental interest including classical and quantum optics, organic and inorganic material science and technology, surface science, spectroscopy, atom manipulation, photonics, and electronics. Each chapter is written by one or more leading scientists from the relevant field. Thus, high-quality scientific and technical information is provided to scientists, engineers, and students engaged in nano-electro optics and nanophotonics research. The first two volumes addressed the "Basics and Theory of Near Field Optics" (2002) and "Novel Devices and Atom Manipulation" (2003).

Mn-silicide nanostructures aligned on massively parallel silicon nano-ribbons

International Nuclear Information System (INIS)

De Padova, Paola; Ottaviani, Carlo; Ronci, Fabio; Colonna, Stefano; Quaresima, Claudio; Cricenti, Antonio; Olivieri, Bruno; Dávila, Maria E; Hennies, Franz; Pietzsch, Annette; Shariati, Nina; Le Lay, Guy

2013-01-01

The growth of Mn nanostructures on a 1D grating of silicon nano-ribbons is investigated at atomic scale by means of scanning tunneling microscopy, low energy electron diffraction and core level photoelectron spectroscopy. The grating of silicon nano-ribbons represents an atomic scale template that can be used in a surface-driven route to control the combination of Si with Mn in the development of novel materials for spintronics devices. The Mn atoms show a preferential adsorption site on silicon atoms, forming one-dimensional nanostructures. They are parallel oriented with respect to the surface Si array, which probably predetermines the diffusion pathways of the Mn atoms during the process of nanostructure formation.

Two-dimensional atom localization via probe absorption in a four-level atomic system

International Nuclear Information System (INIS)

Wang Zhi-Ping; Ge Qiang; Ruan Yu-Hua; Yu Ben-Li

2013-01-01

We have investigated the two-dimensional (2D) atom localization via probe absorption in a coherently driven four-level atomic system by means of a radio-frequency field driving a hyperfine transition. It is found that the detecting probability and precision of 2D atom localization can be significantly improved via adjusting the system parameters. As a result, our scheme may be helpful in laser cooling or the atom nano-lithography via atom localization

Atom probe characterization of nano-scaled features in irradiated Eurofer and ODS Eurofer steel

International Nuclear Information System (INIS)

Rogozkin, S.; Aleev, A.; Nikitin, A.; Zaluzhnyi, A.; Vladimirov, P.; Moeslang, A.; Lindau, R.

2009-01-01

Outstanding performance of oxide dispersion strengthened (ODS) steels at high temperatures and up to high doses allowed to consider them as potential candidates for fusion and fission power plants. At the same time their mechanical parameters strongly correlate with number density of oxide particles and their size. It is believed that fine particles are formed at the last stage of sophisticated production procedures and play a crucial role in higher heat- and radiation resistance in comparison with conventional materials. However, due to their small size - only few nanometers, characterization of such objects requires considerable efforts. Recent study of ODS steel by tomographic atom probe, the most appropriate technique in this case, shown considerable stability of these particles under high temperatures and ion-irradiation. However, these results were obtained for 12/14% Cr with addition of 0.3% Y 2 O 3 and titanium which is inappropriate in case of ODS Eurofer 97 and possibility to substitute neutron by ion irradiation is still under consideration. In this work effect of neutron irradiation on nanostructure behaviour of ODS Eurofer are investigated. Irradiation was performed on research reactor BOR-60 in SSC RF RIAR (Dimitrovgrad, Russia) up to 30 dpa at 280 deg. C and 580 deg. C. Recent investigation of unirradiated state revealed high number density of nano-scaled features (nano-clusters) even without addition of Ti in steel. It was shown that vanadium played significant role in nucleation process and core of nano-clusters was considerably enriched with it. In irradiated samples solution of vanadium in matrix was observed while the size of particles stayed practically unchanged. Also no nitrogen was detected in these particles in comparison with unirradiated state where bond energy of N with V was considered to be high as VN 2+ ions were detected on mass-spectra. (author)

Atomic and nano-scale characterization of a 50-year-old hydrated C3S paste

KAUST Repository

Geng, Guoqing; Taylor, Rae; Bae, Sungchul; Herná ndez-Cruz, Daniel; Kilcoyne, David A.; Emwas, Abdul-Hamid M.; Monteiro, Paulo J M

2015-01-01

This paper investigates the atomic and nano-scale structures of a 50-year-old hydrated alite paste. Imaged by TEM, the outer product C-S-H fibers are composed of particles that are 1.5-2 nm thick and several tens of nanometers long. 29Si NMR shows 47.9% Q1 and 52.1% Q2, with a mean SiO4 tetrahedron chain length (MCL) of 4.18, indicating a limited degree of polymerization after 50 years' hydration. A Scanning Transmission X-ray Microscopy (STXM) study was conducted on this late-age paste and a 1.5 year old hydrated C3S solution. Near Edge X-ray Absorption Fine Structure (NEXAFS) at Ca L3,2-edge indicates that Ca2 + in C-S-H is in an irregular symmetric coordination, which agrees more with the atomic structure of tobermorite than that of jennite. At Si K-edge, multi-scattering phenomenon is sensitive to the degree of polymerization, which has the potential to unveil the structure of the SiO44 - tetrahedron chain. © 2015 Elsevier Ltd. All rights reserved.

Atomic and nano-scale characterization of a 50-year-old hydrated C3S paste

KAUST Repository

Geng, Guoqing

2015-07-15

This paper investigates the atomic and nano-scale structures of a 50-year-old hydrated alite paste. Imaged by TEM, the outer product C-S-H fibers are composed of particles that are 1.5-2 nm thick and several tens of nanometers long. 29Si NMR shows 47.9% Q1 and 52.1% Q2, with a mean SiO4 tetrahedron chain length (MCL) of 4.18, indicating a limited degree of polymerization after 50 years\\' hydration. A Scanning Transmission X-ray Microscopy (STXM) study was conducted on this late-age paste and a 1.5 year old hydrated C3S solution. Near Edge X-ray Absorption Fine Structure (NEXAFS) at Ca L3,2-edge indicates that Ca2 + in C-S-H is in an irregular symmetric coordination, which agrees more with the atomic structure of tobermorite than that of jennite. At Si K-edge, multi-scattering phenomenon is sensitive to the degree of polymerization, which has the potential to unveil the structure of the SiO44 - tetrahedron chain. © 2015 Elsevier Ltd. All rights reserved.

Atomic and nano-scale characterization of a 50-year-old hydrated C3S paste

International Nuclear Information System (INIS)

Geng, Guoqing; Taylor, Rae; Bae, Sungchul; Hernández-Cruz, Daniel; Kilcoyne, David A.; Emwas, Abdul-Hamid; Monteiro, Paulo J.M.

2015-01-01

This paper investigates the atomic and nano-scale structures of a 50-year-old hydrated alite paste. Imaged by TEM, the outer product C–S–H fibers are composed of particles that are 1.5–2 nm thick and several tens of nanometers long. 29 Si NMR shows 47.9% Q 1 and 52.1% Q 2 , with a mean SiO 4 tetrahedron chain length (MCL) of 4.18, indicating a limited degree of polymerization after 50 years' hydration. A Scanning Transmission X-ray Microscopy (STXM) study was conducted on this late-age paste and a 1.5 year old hydrated C 3 S solution. Near Edge X-ray Absorption Fine Structure (NEXAFS) at Ca L 3,2 -edge indicates that Ca 2+ in C–S–H is in an irregular symmetric coordination, which agrees more with the atomic structure of tobermorite than that of jennite. At Si K-edge, multi-scattering phenomenon is sensitive to the degree of polymerization, which has the potential to unveil the structure of the SiO 4 4− tetrahedron chain.

Bringing light into the nano-world: What can you do with an atomic force microscope on top of your synchrotron radiation sample holder?

International Nuclear Information System (INIS)

Rodrigues, Mario Manuel Silveira

2009-01-01

This thesis had as a major objective to combine scanning probe microscopy in particular, atomic force microscopy with synchrotron light spectroscopies. The combination of these two types of spectroscopies is meant to be in-situ and in real time. Thus this thesis aimed at introducing new types of experimental techniques suitable for the investigation of nano-sized materials. The proposed new instrumentation, would provide chemical-specific contrast at unprecedented lateral resolution of up to 10-40 nanometers, thus overcoming existing limitations of the two families of spectroscopy methods and opening a wide range of research opportunities and challenges. For the purpose of combining these techniques an atomic force microscope was developed. The atomic force microscope (AFM) was developed around a quartz tuning fork crystal which was used as the sensor with which atomic forces are detected. The developed AFM was then used in several beam lines with essentially two different purposes. A first goal was to do spectroscopy, such as the measurement of an absorption edge, locally with the tip of the AFM. Such measurements were indeed done, but the lateral resolution is still dominated by the X-ray beam size rather than by the tip apex shape. The AFM tip was also used to measure Bragg peaks from crystals with sizes on the nanometer scale. A second goal was to use the AFM as an instrument to mechanical interact with nano-sized systems while the X-ray beam was used to probe changes in the lattice parameter of the studied systems. Thus the AFM tip was used to elastically indent a SiGe crystal while diffraction was simultaneously measured. It was possible to observe shifts of the Bragg peak as a consequence of the applied pressure. The in-situ combination of AFM with synchrotron light permitted, in this way, to measure the Young modulus of a crystal at the nano-scale without any kind of adjustable parameter. (author)

Scalable cavity-QED-based scheme of generating entanglement of atoms and of cavity fields

OpenAIRE

Lee, Jaehak; Park, Jiyong; Lee, Sang Min; Lee, Hai-Woong; Khosa, Ashfaq H.

2008-01-01

We propose a cavity-QED-based scheme of generating entanglement between atoms. The scheme is scalable to an arbitrary number of atoms, and can be used to generate a variety of multipartite entangled states such as the Greenberger-Horne-Zeilinger, W, and cluster states. Furthermore, with a role switching of atoms with photons, the scheme can be used to generate entanglement between cavity fields. We also introduce a scheme that can generate an arbitrary multipartite field graph state.

Tritium labeling for bio-med research

International Nuclear Information System (INIS)

Lemmon, R.M.

1980-01-01

A very large fraction of what we know about biochemical pathways in the living cell has resulted from the use of radioactively-labeled tracer compounds; the use of tritium-labeled compounds has been particularly important. As research in biochemistry and biology has progressed the need has arisen to label compounds of higher specific activity and of increasing molecular complexity - for example, oligo-nucleotides, polypeptides, hormones, enzymes. Our laboratory has gradually developed special facilities for handling tritium at the kilocurie level. These facilities have already proven extremely valuable in producing labeled compounds that are not available from commercial sources. The principal ways employed for compound labeling are: (1) microwave discharge labeling, (2) catalytic tritio-hydrogenation, (3) catalytic exchange with T 2 O, and (4) replacement of halogen atoms by T. Studies have also been carried out on tritiation by the replacement of halogen atoms with T atoms. These results indicate that carrier-free tritium-labeled products, including biomacromolecules, can be produced in this way

CZT nanoRAIDER_VFG Factsheet

Energy Technology Data Exchange (ETDEWEB)

James, R. [Brookhaven National Lab. (BNL), Upton, NY (United States); Bolotnikov, A. E. [Brookhaven National Lab. (BNL), Upton, NY (United States); Cui, Yonggang [Brookhaven National Lab. (BNL), Upton, NY (United States)

2016-01-15

Brookhaven National Laboratory (BNL) is working with FLIR System Inc., the manufacturer of the nanoRAIDER, to design a handheld device based on a position-sensitive virtual Frisch-grid (VFG) Cadmium-Zinc-Telluride (CdZnTe or CZT) detector array (with 1% or better energy resolution). The new device called nanoRAIDER VFG will be an improvement to the current nanoRAIDER, which is a compact gamma-ray detection instrument manufactured by FLIR Systems Inc. that employs relatively lower-performing CZT hemispheric detectors (i.e., 3%-FWHM CZT detectors). The nanoRAIDER will significantly improve the accuracy while maintaining similar efficiency, as compared to the nanoRAIDER, for in-field analysis of nuclear materials and detection of undeclared activities during inspections conducted by the International Atomic Energy Agency (IAEA). Since the nanoRAIDER is currently used by the IAEA as part of its Complementary Access toolkit, a relatively quick acceptance of the nanoRAIDER VFG for safeguards is anticipated. The nanoRAIDER VFG will help address several items listed in the IAEA’s Long-Term R&D Plan that could enhance the abilities to detect undeclared nuclear material and activities.

Remote Generation of Entanglement for Individual Atoms via Optical Fibres

International Nuclear Information System (INIS)

Yan-Qing, Guo; Hai-Yang, Zhong; Ying-Hui, Zhang; He-Shan, Song

2008-01-01

The generation of atomic entanglement is discussed in a system that atoms are trapped in separate cavities which are connected via optical fibres. Two distant atoms can be projected to Bell-state by synchronized turning off of the local laser fields and then performing a single quantum measurement by a distant controller. The distinct advantage of this scheme is that it works in a regime where Δ ≈ κ ≫ g, which makes the scheme insensitive to cavity strong leakage. Moreover, the fidelity is not affected by atomic spontaneous emission. (general)

Mechanical properties of ultra-thin HfO2 films studied by nano scratches tests

International Nuclear Information System (INIS)

Fu, Wei-En; Chang, Yong-Qing; Chang, Chia-Wei; Yao, Chih-Kai; Liao, Jiunn-Der

2013-01-01

10-nm-thick atomic layer deposited HfO 2 films were characterized in terms of wear resistance and indentation hardness to investigate the thermal annealing induced impacts on mechanical properties. The wear resistance of ultra-thin films at low loads was characterized using nano-scratch tests with an atomic force microscope. The depth of the nano-scratches decreases with increasing annealing temperature, indicating that the hardness of the annealed films increases with the annealing temperatures. Surface nanoindentation was also performed to confirm the nanoscratch test results. The hardness variation of the annealed films is due to the generation of HfSi x O y induced by the thermal annealing. X-ray photoelectron spectroscopy measurements proved that the hardness of formed HfSi x O y with increasing annealing temperatures. The existence of HfSi x O y broadens the interface, and causes the increase of the interfacial layer thickness. As a result, the surface hardness increases with the increasing HfSi x O y induced by the thermal annealing. - Highlights: ► Mechanical properties of HfO 2 films were assessed by nano-scratch and indentation. ► Scratch depth of HfO 2 films decreased with the increase of annealing temperatures. ► Nano-hardness of HfO 2 films increased with the increase of annealing temperatures

Effect of TMAH Etching Duration on the Formation of Silicon Nano wire Transistor Patterned by AFM Nano lithography

International Nuclear Information System (INIS)

Hutagalung, S.D.; Lew, K.C.

2012-01-01

Atomic force microscopy (AFM) lithography was applied to produce nano scale pattern for silicon nano wire transistor fabrication. This technique takes advantage of imaging facility of AFM and the ability of probe movement controlling over the sample surface to create nano patterns. A conductive AFM tip was used to grow the silicon oxide nano patterns on silicon on insulator (SOI) wafer. The applied tip-sample voltage and writing speed were well controlled in order to form pre-designed silicon oxide nano wire transistor structures. The effect of tetra methyl ammonium hydroxide (TMAH) etching duration on the oxide covered silicon nano wire transistor structure has been investigated. A completed silicon nano wire transistor was obtained by removing the oxide layer via hydrofluoric acid etching process. The fabricated silicon nano wire transistor consists of a silicon nano wire that acts as a channel with source and drain pads. A lateral gate pad with a nano wire head was fabricated very close to the channel in the formation of transistor structures. (author)

Atomic Force Microscopy Images Label-Free, Drug Encapsulated Nanoparticles In Vivo and Detects Difference in Tissue Mechanical Properties of Treated and Untreated: A Tip for Nanotoxicology

Science.gov (United States)

Lamprou, Dimitrios A.; Venkatpurwar, Vinod; Kumar, M. N. V. Ravi

2013-01-01

Overcoming the intractable challenge of imaging of label-free, drug encapsulated nanoparticles in tissues in vivo would directly address associated regulatory concerns over 'nanotoxicology'. Here we demonstrate the utility of Atomic Force Microscopy (AFM) for visualising label-free, drug encapsulated polyester particles of ∼280 nm distributed within tissues following their intravenous or peroral administration to rodents. A surprising phenomenon, in which the tissues' mechanical stiffness was directly measured (also by AFM) and related to the number of embedded nanoparticles, was utilised to generate quantitative data sets for nanoparticles localisation. By coupling the normal determination of a drug's pharmacokinetics/pharmacodynamics with post-sacrifice measurement of nanoparticle localisation and number, we present for the first time an experimental design in which a single in vivo study relates the PK/PD of a nanomedicine to its toxicokinetics. PMID:23724054

Pulse electrochemical meso/micro/nano ultraprecision machining technology.

Science.gov (United States)

Lee, Jeong Min; Kim, Young Bin; Park, Jeong Woo

2013-11-01

This study demonstrated meso/micro/nano-ultraprecision machining through electrochemical reactions using intermittent DC pulses. The experiment focused on two machining methods: (1) pulse electrochemical polishing (PECP) of stainless steel, and (2) pulse electrochemical nano-patterning (PECNP) on a silicon (Si) surface, using atomic force microscopy (AFM) for fabrication. The dissolution reaction at the stainless steel surface following PECP produced a very clean, smooth workpiece. The advantages of the PECP process included improvements in corrosion resistance, deburring of the sample surface, and removal of hydrogen from the stainless steel surface as verified by time-of-flight secondary-ion mass spectrometry (TOF-SIMS). In PECNP, the electrochemical reaction generated within water molecules produced nanoscale oxide textures on a Si surface. Scanning probe microscopy (SPM) was used to evaluate nanoscale-pattern processing on a Si wafer surface produced by AFM-PECNP For both processes using pulse electrochemical reactions, three-dimensional (3-D) measurements and AFM were used to investigate the changes on the machined surfaces. Preliminary results indicated the potential for advancing surface polishing techniques and localized micro/nano-texturing technology using PECP and PECNP processes.

Enantio-specific C(sp3)-H activation catalyzed by ruthenium nanoparticles: application to isotopic labeling of molecules of biological interest

International Nuclear Information System (INIS)

Taglang, Celine

2015-01-01

dimetallacycle key-intermediate with four centers. The second part of this thesis deals with the development of a new method for the determination of the conformation and the relative arrangement of auto-assembled small molecules. It is based on the synergy between labeling chemistry, tritium solid-state NMR and molecular modeling. We focused on the di-phenylalanine dipeptide (Phe-Phe) which forms either crystals or self-assembled nano-tubes depending on the solvent. If the crystalline atomic structure of Phe-Phe has been solved, the structure of the self-assembled nano-tubes of Phe-Phe is still unknown. Three Phe-Phe dipeptides di-tritiated on aromatic positions, determined with the help of molecular modeling by Dr. Yves Boulard (CEA Saclay), were synthesized. Tritium solid-state NMR allowed Dr. Thibault Charpentier (CEA Saclay) to measure, on crystallized samples, three inter-tritium distances very close to the reference distances. This technique also revealed a possible orientational disorder on an aromatic cycle of crystallized Phe-Phe. Ab initio modeling led us to set a double labeling Caryl and Cα on Phe-Phe with ruthenium nanoparticles. Deuteration with RuNP(at)PVP are very promising and supplementary studies are in progress to perform tritium labeling. We expect to set a new tool of structural study to determine atomic structures of small molecules integrated in supramolecular complexes (nano-tubes, amyloid peptides or membranes). (author) [fr

Atomic bonding between metal and graphene

KAUST Repository

Wang, Hongtao

2013-03-07

To understand structural and chemical properties of metal-graphene composites, it is crucial to unveil the chemical bonding along the interface. We provide direct experimental evidence of atomic bonding between typical metal nano structures and graphene, agreeing well with density functional theory studies. Single Cr atoms are located in the valleys of a zigzag edge, and few-atom ensembles preferentially form atomic chains by self-assembly. Low migration barriers lead to rich dynamics of metal atoms and clusters under electron irradiation. We demonstrate no electron-instigated interaction between Cr clusters and pristine graphene, though Cr has been reported to be highly reactive to graphene. The metal-mediated etching is a dynamic effect between metal clusters and pre-existing defects. The resolved atomic configurations of typical nano metal structures on graphene offer insight into modeling and simulations on properties of metal-decorated graphene for both catalysis and future carbon-based electronics. © 2013 American Chemical Society.

Nano Scale Mechanical Analysis of Biomaterials Using Atomic Force Microscopy

Science.gov (United States)

Dutta, Diganta

The atomic force microscope (AFM) is a probe-based microscope that uses nanoscale and structural imaging where high resolution is desired. AFM has also been used in mechanical, electrical, and thermal engineering applications. This unique technique provides vital local material properties like the modulus of elasticity, hardness, surface potential, Hamaker constant, and the surface charge density from force versus displacement curve. Therefore, AFM was used to measure both the diameter and mechanical properties of the collagen nanostraws in human costal cartilage. Human costal cartilage forms a bridge between the sternum and bony ribs. The chest wall of some humans is deformed due to defective costal cartilage. However, costal cartilage is less studied compared to load bearing cartilage. Results show that there is a difference between chemical fixation and non-chemical fixation treatments. Our findings imply that the patients' chest wall is mechanically weak and protein deposition is abnormal. This may impact the nanostraws' ability to facilitate fluid flow between the ribs and the sternum. At present, AFM is the only tool for imaging cells' ultra-structure at the nanometer scale because cells are not homogeneous. The first layer of the cell is called the cell membrane, and the layer under it is made of the cytoskeleton. Cancerous cells are different from normal cells in term of cell growth, mechanical properties, and ultra-structure. Here, force is measured with very high sensitivity and this is accomplished with highly sensitive probes such as a nano-probe. We performed experiments to determine ultra-structural differences that emerge when such cancerous cells are subject to treatments such as with drugs and electric pulses. Jurkat cells are cancerous cells. These cells were pulsed at different conditions. Pulsed and non-pulsed Jurkat cell ultra-structures were investigated at the nano meter scale using AFM. Jurkat cell mechanical properties were measured under

Mechanical properties of ultra-thin HfO{sub 2} films studied by nano scratches tests

Energy Technology Data Exchange (ETDEWEB)

Fu, Wei-En; Chang, Yong-Qing [Center for Measurement Standards, Industrial Technology Research Institute, Room 216, Building 8, 321, Kuang Fu Road Sec. 2, Hsinchu, Taiwan (China); Chang, Chia-Wei; Yao, Chih-Kai [Department of Materials Science and Engineering, National Cheng Kung University, 1 University Road, Tainan 70101, Taiwan (China); Liao, Jiunn-Der, E-mail: jdliao@mail.ncku.edu.tw [Department of Materials Science and Engineering, National Cheng Kung University, 1 University Road, Tainan 70101, Taiwan (China); Center for Micro/Nano Science and Technology, National Cheng Kung University, 1 University Road, Tainan 70101, Taiwan (China)

2013-02-01

10-nm-thick atomic layer deposited HfO{sub 2} films were characterized in terms of wear resistance and indentation hardness to investigate the thermal annealing induced impacts on mechanical properties. The wear resistance of ultra-thin films at low loads was characterized using nano-scratch tests with an atomic force microscope. The depth of the nano-scratches decreases with increasing annealing temperature, indicating that the hardness of the annealed films increases with the annealing temperatures. Surface nanoindentation was also performed to confirm the nanoscratch test results. The hardness variation of the annealed films is due to the generation of HfSi{sub x}O{sub y} induced by the thermal annealing. X-ray photoelectron spectroscopy measurements proved that the hardness of formed HfSi{sub x}O{sub y} with increasing annealing temperatures. The existence of HfSi{sub x}O{sub y} broadens the interface, and causes the increase of the interfacial layer thickness. As a result, the surface hardness increases with the increasing HfSi{sub x}O{sub y} induced by the thermal annealing. - Highlights: ► Mechanical properties of HfO{sub 2} films were assessed by nano-scratch and indentation. ► Scratch depth of HfO{sub 2} films decreased with the increase of annealing temperatures. ► Nano-hardness of HfO{sub 2} films increased with the increase of annealing temperatures.

Label-free tracking of single extracellular vesicles in a nano-fluidic optical fiber (Conference Presentation)

Science.gov (United States)

van der Pol, Edwin; Weidlich, Stefan; Lahini, Yoav; Coumans, Frank A. W.; Sturk, Auguste; Nieuwland, Rienk; Schmidt, Markus A.; Faez, Sanli; van Leeuwen, Ton G.

2016-03-01

Background: Extracellular vesicles, such as exosomes, are abundantly present in human body fluids. Since the size, concentration and composition of these vesicles change during disease, vesicles have promising clinical applications, including cancer diagnosis. However, since ~70% of the vesicles have a diameter <70 nm, detection of single vesicles remains challenging. Thus far, vesicles <70 nm have only be studied by techniques that require the vesicles to be adhered to a surface. Consequently, the majority of vesicles have never been studied in their physiological environment. We present a novel label-free optical technique to track single vesicles <70 nm in suspension. Method: Urinary vesicles were contained within a single-mode light-guiding silica fiber containing a 600 nm nano-fluidic channel. Light from a diode laser (660 nm wavelength) was coupled to the fiber, resulting in a strongly confined optical mode in the nano-fluidic channel, which continuously illuminated the freely diffusing vesicles inside the channel. The elastic light scattering from the vesicles, in the direction orthogonal to the fiber axis, was collected using a microscope objective (NA=0.95) and imaged with a home-built microscope. Results: We have tracked single urinary vesicles as small as 35 nm by elastic light scattering. Please note that vesicles are low-refractive index (n<1.4) particles, which we confirmed by combining data on thermal diffusion and light scattering cross section. Conclusions: For the first time, we have studied vesicles <70 nm freely diffusing in suspension. The ease-of-use and performance of this technique support its potential for vesicle-based clinical applications.

Self-decomposition components generated from [sup 35]S-labeled amino acids

Energy Technology Data Exchange (ETDEWEB)

Kato, Takahisa; Saito, Kazumi; Kurihara, Norio (Kyoto Univ. (Japan). Radioisotope Research Center)

1994-06-01

We examined the fragment molecules in the gaseous components generated from [sup 35]S-amino acids with high specific radioactivity. The self-decomposition mode of a molecule labeled with a [beta]-emitter was similar to the fragmentation mode of organic compounds impacted by accelerated electrons as in organic mass spectrometry. Degradation products of unlabeled amino acids irradiated by [sup 60]Co [gamma]-ray indicated that the degradation mode induced by external [gamma]-rays irradiation was different from the self-decomposition mode of labeled compounds. (Author).

Managing collaboration in the nanoManipulator

DEFF Research Database (Denmark)

Hudson, Thomas C.; Heiser, Aron T.; Sonnenwald, Diane H.

2003-01-01

We designed, developed, deployed, and evaluated the Collaborative nanoManipulator (CnM), a system supporting remote collaboration between users of the nanoManipulator interface to atomic force microscopes. To be accepted by users, the shared nanoManipulator application had to have the same high...... level of interactivity as the single user system and the application had to support a user's ability to interleave working privately and working collaboratively. This paper briefly describes the entire collaboration system, but focuses on the shared nanoManipulator application. Based on our experience...... developing the CnM, we present: a method of analyzing applications to characterize the requirements for sharing data between collaborating sites, examples of data structures that support collaboration, and guidelines for selecting appropriate synchronization and concurrency control schemes....

Computer simulations for the nano-scale

International Nuclear Information System (INIS)

Stich, I.

2007-01-01

A review of methods for computations for the nano-scale is presented. The paper should provide a convenient starting point into computations for the nano-scale as well as a more in depth presentation for those already working in the field of atomic/molecular-scale modeling. The argument is divided in chapters covering the methods for description of the (i) electrons, (ii) ions, and (iii) techniques for efficient solving of the underlying equations. A fairly broad view is taken covering the Hartree-Fock approximation, density functional techniques and quantum Monte-Carlo techniques for electrons. The customary quantum chemistry methods, such as post Hartree-Fock techniques, are only briefly mentioned. Description of both classical and quantum ions is presented. The techniques cover Ehrenfest, Born-Oppenheimer, and Car-Parrinello dynamics. The strong and weak points of both principal and technical nature are analyzed. In the second part we introduce a number of applications to demonstrate the different approximations and techniques introduced in the first part. They cover a wide range of applications such as non-simple liquids, surfaces, molecule-surface interactions, applications in nano technology, etc. These more in depth presentations, while certainly not exhaustive, should provide information on technical aspects of the simulations, typical parameters used, and ways of analysis of the huge amounts of data generated in these large-scale supercomputer simulations. (author)

Nano-design of quantum dot-based photocatalysts for hydrogen generation using advanced surface molecular chemistry

KAUST Repository

Yu, Weili; Noureldine, Dalal; Isimjan, Tayirjan T.; Lin, Bin; Del Gobbo, Silvano; Abulikemu, Mutalifu; Hedhili, Mohamed N.; Anjum, Dalaver H.; Takanabe, Kazuhiro

2015-01-01

Efficient photocatalytic hydrogen generation in a suspension system requires a sophisticated nano-device that combines a photon absorber with effective redox catalysts. This study demonstrates an innovative molecular linking strategy for fabricating photocatalytic materials that allow effective charge separation of excited carriers, followed by efficient hydrogen evolution. The method for the sequential replacement of ligands with appropriate molecules developed in this study tethers both quantum dots (QDs), as photosensitizers, and metal nanoparticles, as hydrogen evolution catalysts, to TiO2 surfaces in a controlled manner at the nano-level. Combining hydrophobic and hydrophilic interactions on the surface, CdSe-ZnS core-shell QDs and an Au-Pt alloy were attached to TiO2 without overlapping during the synthesis. The resultant nano-photocatalysts achieved substantially high-performance visible-light-driven photocatalysis for hydrogen evolution. All syntheses were conducted at room temperature and in ambient air, providing a promising route for fabricating visible-light-responsive photocatalysts.

Sequential optimization of methotrexate encapsulation in micellar nano-networks of polyethyleneimine ionomer containing redox-sensitive cross-links.

Science.gov (United States)

Abolmaali, Samira Sadat; Tamaddon, Ali; Yousefi, Gholamhossein; Javidnia, Katayoun; Dinarvand, Rasoul

2014-01-01

A functional polycation nanonetwork was developed for delivery of water soluble chemotherapeutic agents. The complexes of polyethyleneimine grafted methoxy polyethylene glycol (PEI-g-mPEG) and Zn(2+) were utilized as the micellar template for cross-linking with dithiodipropionic acid, followed by an acidic pH dialysis to remove the metal ion from the micellar template. The synthesis method was optimized according to pH, the molar ratio of Zn(2+), and the cross-link ratio. The atomic force microscopy showed soft, discrete, and uniform nano-networks. They were sensitive to the simulated reductive environment as determined by Ellman's assay. They showed few positive ζ potential and an average hydrodynamic diameter of 162±10 nm, which decreased to 49±11 nm upon dehydration. The ionic character of the nano-networks allowed the achievement of a higher-loading capacity of methotrexate (MTX), approximately 57% weight per weight, depending on the cross-link and the drug feed ratios. The nano-networks actively loaded with MTX presented some suitable properties, such as the hydrodynamic size of 117±16 nm, polydispersity index of 0.22, and a prolonged swelling-controlled release profile over 24 hours that boosted following reductive activation of the nanonetwork biodegradation. Unlike the PEI ionomer, the nano-networks provided an acceptable cytotoxicity profile. The drug-loaded nano-networks exhibited more specific cytotoxicity against human hepatocellular carcinoma cells if compared to free MTX at concentrations above 1 μM. The enhanced antitumor activity in vitro might be attributed to endocytic entry of MTX-loaded nano-networks that was found in the epifluorescence microscopy experiment for the fluorophore-labeled nano-networks.

Atomic-Layer-Deposition of Indium Oxide Nano-films for Thin-Film Transistors.

Science.gov (United States)

Ma, Qian; Zheng, He-Mei; Shao, Yan; Zhu, Bao; Liu, Wen-Jun; Ding, Shi-Jin; Zhang, David Wei

2018-01-09

Atomic-layer-deposition (ALD) of In 2 O 3 nano-films has been investigated using cyclopentadienyl indium (InCp) and hydrogen peroxide (H 2 O 2 ) as precursors. The In 2 O 3 films can be deposited preferentially at relatively low temperatures of 160-200 °C, exhibiting a stable growth rate of 1.4-1.5 Å/cycle. The surface roughness of the deposited film increases gradually with deposition temperature, which is attributed to the enhanced crystallization of the film at a higher deposition temperature. As the deposition temperature increases from 150 to 200 °C, the optical band gap (E g ) of the deposited film rises from 3.42 to 3.75 eV. In addition, with the increase of deposition temperature, the atomic ratio of In to O in the as-deposited film gradually shifts towards that in the stoichiometric In 2 O 3 , and the carbon content also reduces by degrees. For 200 °C deposition temperature, the deposited film exhibits an In:O ratio of 1:1.36 and no carbon incorporation. Further, high-performance In 2 O 3 thin-film transistors with an Al 2 O 3 gate dielectric were achieved by post-annealing in air at 300 °C for appropriate time, demonstrating a field-effect mobility of 7.8 cm 2 /V⋅s, a subthreshold swing of 0.32 V/dec, and an on/off current ratio of 10 7 . This was ascribed to passivation of oxygen vacancies in the device channel.

Investigation of growth, coverage and effectiveness of plasma assisted nano-films of fluorocarbon

International Nuclear Information System (INIS)

Joshi, Pratik P.; Pulikollu, Rajasekhar; Higgins, Steven R.; Hu Xiaoming; Mukhopadhyay, S.M.

2006-01-01

Plasma-assisted functional films have significant potential in various engineering applications. They can be tailored to impart desired properties by bonding specific molecular groups to the substrate surface. The aim of this investigation was to develop a fundamental understanding of the atomic level growth, coverage and functional effectiveness of plasma nano-films on flat surfaces and to explore their application-potential for complex and uneven shaped nano-materials. In this paper, results on plasma-assisted nano-scale fluorocarbon films, which are known for imparting inertness or hydrophobicity to the surface, will be discussed. The film deposition was studied as a function of time on flat single crystal surfaces of silicon, sapphire and graphite, using microwave plasma. X-ray photoelectron spectroscopy (XPS) was used for detailed study of composition and chemistry of the substrate and coating atoms, at all stages of deposition. Atomic force microscopy (AFM) was performed in parallel to study the coverage and growth morphology of these films at each stage. Combined XPS and AFM results indicated complete coverage of all the substrates at the nanometer scale. It was also shown that these films grew in a layer-by-layer fashion. The nano-films were also applied to complex and uneven shaped nano-structured and porous materials, such as microcellular porous foam and nano fibers. It was seen that these nano-films can be a viable approach for effective surface modification of complex or uneven shaped nano-materials

Atomic structure of Zr{sub 41.2}Ti{sub 13.8}Cu{sub 12.5}Ni{sub 10}Be{sub 22.5} bulk metallic glass alloy

Energy Technology Data Exchange (ETDEWEB)

Hui, X. [State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing 100083 (China)], E-mail: huixd01@hotmail.com; Fang, H.Z.; Chen, G.L. [State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing 100083 (China); Shang, S.L.; Wang, Y. [Department of Materials Science and Engineering, Pennsylvania State University, University Park, PA 16802 (United States); Qin, J.Y. [Key Laboratory of Liquid Structure and Heredity of Materials, Ministry of Education, Shandong University - Southern Campus, Jinan 250061 (China); Liu, Z.K. [Department of Materials Science and Engineering, Pennsylvania State University, University Park, PA 16802 (United States)

2009-01-15

Ab initio molecular dynamics (AIMD) calculations were performed on the atomic configuration of Zr{sub 41.2}Ti{sub 13.8}Cu{sub 12.5}Ni{sub 10}Be{sub 22.5} bulk metallic glass. The local structures were characterized in terms of structure factors (SF), pair correlation functions (PCF), coordinate numbers, bond pairs and Voronoi polyhedra. The glass transition temperature, generalized PCF and SF predicated by AIMD are in good agreement with the experimental data. Icosahedral short-range orders (ISRO) are found to be the most dominant, in view of the presence of the majority of bond pairs with 1551, 1541 and 1431, and Voronoi polyhedra with <0,3,6,1>, <0,2,8,1>, <0,0,12,0> and <0,2,8,4>. Icosahedral medium range orders (IMROs) are formed from icosahedra via the linkage of vertex-, edge-, face- and intercross-shared atoms. The glass structure on the nanometer scale is accumulated by polyhedra through an efficient packing mode. It is suggested that the extraordinary glass-forming ability of this alloy is essentially attributable to the formation of ISRO and IMRO, and the dense packing of atoms.

Simulating spontaneously generated coherence in a four-level atomic system

International Nuclear Information System (INIS)

Li Aijun; Gao Jinyue; Wu Jinhui; Wang Lei

2005-01-01

We study the spontaneous emission property of a four-level atomic system driven by two coherent fields. By numerical calculations in the bare state picture, we show that such interesting phenomena as extremely narrow peaks and spontaneous emission quenching can be realized, which are well understood by qualitative explanations in the partially and fully dressed state pictures. Especially, this coherently driven atomic system has two close-lying levels in the partially dressed state picture so that spontaneously generated coherence arises. Using our considered scheme it is feasible to carry out experiments based on spontaneously generated coherence because all rigorous requirements have been avoided in the bare state picture

Determination of antimony by using a quartz atom trap and electrochemical hydride generation atomic absorption spectrometry

Energy Technology Data Exchange (ETDEWEB)

Menemenlioglu, Ipek; Korkmaz, Deniz [Department of Chemistry, Middle East Technical University, 06531 Ankara (Turkey); Ataman, O. Yavuz [Department of Chemistry, Middle East Technical University, 06531 Ankara (Turkey)], E-mail: ataman@metu.edu.tr

2007-01-15

The analytical performance of a miniature quartz trap coupled with electrochemical hydride generator for antimony determination is described. A portion of the inlet arm of the conventional quartz tube atomizer was used as an integrated trap medium for on-line preconcentration of electrochemically generated hydrides. This configuration minimizes transfer lines and connections. A thin-layer of electrochemical flow through cell was constructed. Lead and platinum foils were employed as cathode and anode materials, respectively. Experimental operation conditions for hydride generation as well as the collection and revolatilization conditions for the generated hydrides in the inlet arm of the quartz tube atomizer were optimized. Interferences of copper, nickel, iron, cobalt, arsenic, selenium, lead and tin were examined both with and without the trap. 3{sigma} limit of detection was estimated as 0.053 {mu}g l{sup -1} for a sample size of 6.0 ml collected in 120 s. The trap has provided 18 fold sensitivity improvement as compared to electrochemical hydride generation alone. The accuracy of the proposed technique was evaluated with two standard reference materials; Trace Metals in Drinking Water, Cat CRM-TMDW and Metals on Soil/Sediment 4, IRM-008.

Atom-resolved AFM imaging of calcite nanoparticles in water

Energy Technology Data Exchange (ETDEWEB)

Imada, Hirotake; Kimura, Kenjiro [Department of Chemistry, School of Science, Kobe University, Rokko-dai, Nada, Kobe 657-8501 (Japan); Onishi, Hiroshi, E-mail: oni@kobe-u.ac.jp [Department of Chemistry, School of Science, Kobe University, Rokko-dai, Nada, Kobe 657-8501 (Japan)

2013-06-20

Highlights: ► An advanced frequency-modulation AFM (FM-AFM) was applied for imaging particles. ► Atom-resolved topography of nano-sized particles of calcite was observed in water. ► Locally ordered structures were found and assigned to a (104) facet of calcite. ► A promising ability of FM-AFM was demonstrated in imaging nano-sized particles. - Abstract: The atom-resolved topography of calcite nanoparticles was observed in water using a frequency-modulation atomic force microscope. Locally ordered structures were found and assigned to a (104) facet of crystalline calcite.

Atom-resolved AFM imaging of calcite nanoparticles in water

International Nuclear Information System (INIS)

Imada, Hirotake; Kimura, Kenjiro; Onishi, Hiroshi

2013-01-01

Highlights: ► An advanced frequency-modulation AFM (FM-AFM) was applied for imaging particles. ► Atom-resolved topography of nano-sized particles of calcite was observed in water. ► Locally ordered structures were found and assigned to a (104) facet of calcite. ► A promising ability of FM-AFM was demonstrated in imaging nano-sized particles. - Abstract: The atom-resolved topography of calcite nanoparticles was observed in water using a frequency-modulation atomic force microscope. Locally ordered structures were found and assigned to a (104) facet of crystalline calcite

Nano-electron beam induced current and hole charge dynamics through uncapped Ge nanocrystals

Energy Technology Data Exchange (ETDEWEB)

Marchand, A.; El Hdiy, A.; Troyon, M. [Laboratoire de Recherche en Nanosciences, Bat. 6, case no 15, UFR Sciences, Universite de Reims Champagne Ardenne, 51687 Reims Cedex 2 (France); Amiard, G.; Ronda, A.; Berbezier, I. [IM2NP, Faculte des Sciences et Techniques, Campus de Saint Jerome - Case 142, Avenue Escadrille Normandie Niemen, 13397 Marseille Cedex 20 (France)

2012-04-16

Dynamics of hole storage in spherical Ge nanocrystals (NCs) formed by a two step dewetting/nucleation process on an oxide layer grown on an n-doped <001> silicon substrate is studied using a nano-electron beam induced current technique. Carrier generation is produced by an electron beam irradiation. The generated current is collected by an atomic force microscope--tip in contact mode at a fixed position away from the beam spot of about 0.5 {mu}m. This distance represents the effective diffusion length of holes. The time constants of holes charging are determined and the effect of the NC size is underlined.

Three-dimensional atom localization via electromagnetically induced transparency in a three-level atomic system.

Science.gov (United States)

Wang, Zhiping; Cao, Dewei; Yu, Benli

2016-05-01

We present a new scheme for three-dimensional (3D) atom localization in a three-level atomic system via measuring the absorption of a weak probe field. Owing to the space-dependent atom-field interaction, the position probability distribution of the atom can be directly determined by measuring the probe absorption. It is found that, by properly varying the parameters of the system, the probability of finding the atom in 3D space can be almost 100%. Our scheme opens a promising way to achieve high-precision and high-efficiency 3D atom localization, which provides some potential applications in laser cooling or atom nano-lithography via atom localization.

Generation of Atomic Greenberger-Horne-Zeilinger States Based on Faraday Rotation

International Nuclear Information System (INIS)

Liang Honghui; Li Xinghua

2010-01-01

Based on the input-output relation of the cavity and the Faraday Rotation mechanism, we propose a scheme for generating the n-atom Greenberger-Horne-Zeilinger state. In the scheme, the n-atom trapped respectively in n spatially separate cavities would be entangled with the photons going through the atom-cavity system. The successful probabilities of our protocol approach unity in the ideal case. What is more, no requirement for separately addressing further lowers experimental difficulties. (general)

Atomically Phase-Matched Second-Harmonic Generation in a 2D Crystal

Science.gov (United States)

2016-08-26

OPEN ORIGINAL ARTICLE Atomically phase-matched second-harmonic generation in a 2D crystal Mervin Zhao1,2,*, Ziliang Ye1,2,*, Ryuji Suzuki3,4,*, Yu...photoluminescence mapping, Raman spectroscopy and atomic -force microscopy. (b) Image produced via scanning and gathering the SH light produced by the 3R-MoS2...arising from a single atomic layer, where the SH light elucidated important information such as the grain boundaries and electronic structure in these ultra

Generation labels in composite models for quarks and leptons

International Nuclear Information System (INIS)

Harari, H.; Seiberg, N.

1981-03-01

Models in which quarks and leptons are approximately massless composites of fundamental massless fermions which are confined by a hypercolor force are considered. The fundamental Lagrangian exhibits an axial U(1)sub(X) symmetry which is broken by hypercolor instantons, leaving a conserved discrete subgroup. It is proposed that the distinction between different generations of quarks and leptons is given by the X-number. The resulting generation labelling scheme does not lead to massless Goldstone bosons or to new anomalies and is based on a quantum number which is already contained in the theory. The dynamical rishon model is described as an illustrative example. (H.K.)

Nano-structural characteristics and optical properties of silver chiral nano-flower sculptured thin films

International Nuclear Information System (INIS)

Savaloni, Hadi; Haydari-Nasab, Fatemh; Malmir, Mariam

2011-01-01

Silver chiral nano-flowers with 3-, 4- and 5-fold symmetry were produced using oblique angle deposition method in conjunction with the rotation of sample holder with different speeds at different sectors of each revolution corresponding to symmetry order of the acquired nano-flower. Atomic force microscopy (AFM) and field emission scanning electron microscopy (FESEM), were employed to obtain morphology and nano-structure of the films. Optical characteristics of silver chiral nano-flower thin films were obtained using single beam spectrophotometer with both s- and p-polarization incident light at 30 o and 70 o incidence angles and at different azimuthal angles (φ). Optical spectra showed both TM (TDM (transverse dipole mode) and TQM (transverse quadruple mode)) and LM (longitudinal mode) Plasmon resonance peaks. For 3- and 4-fold symmetry chiral nano-flowers the s-polarization extinction spectra obtained at different azimuthal angles did not show significant change in the Plasmon peak position while 5-fold symmetry chiral nano-flower showed a completely different behavior, which may be the result of increased surface anisotropy, so when the φ angle is changed the s-polarization response from the surface can change more significantly than that for lower symmetries. In general, for 3-, 4- and 5-fold symmetry chiral nano-flowers a sharp peak at lower wavelengths ( o incidence angle.

Hydride generation – in-atomizer collection of Pb in a quartz trap-and-atomizer device for atomic absorption spectrometry – an interference study

Energy Technology Data Exchange (ETDEWEB)

Novotný, Pavel [Institute of Analytical Chemistry of the ASCR, v.v.i., Veveří 97, 602 00 Brno (Czech Republic); High School in Hořice, Husova 1414, 508 01 Hořice (Czech Republic); Kratzer, Jan, E-mail: jkratzer@biomed.cas.cz [Institute of Analytical Chemistry of the ASCR, v.v.i., Veveří 97, 602 00 Brno (Czech Republic)

2013-01-01

Interferences of selected hydride forming elements (As, Sb, Bi, Se and Sn) on lead determination by hydride generation atomic absorption spectrometry were extensively studied in both on-line atomization and preconcentration (collection) modes. The commonly used on-line atomization mode was found free of significant interferences, whereas strong interference from Bi was observed when employing the preconcentration mode with plumbane collection in a quartz trap-and-atomizer device. Interference of Bi seems to take place in the preconcentration step. Interference of Bi in the collection mode cannot be reduced by increased hydrogen radical amount in the trap and/or the atomizer. - Highlights: ► Interference study on Pb determination by in-atomizer trapping was performed for the first time. ► Bi was found as a severe interferent in the preconcentration mode (Pb:Bi ratio 1:100). ► No interference was found in the on-line atomization (no preconcentration). ► Bi interference occurs during preconcentration.

Performance of PZC-Mo generator and labeling results prepared with its eluate and MDP kit

International Nuclear Information System (INIS)

Yishu Liu

2006-01-01

This paper described the performance of Tc-99m generator prepared with Mo adsorbent PZC and irradiated nature MoO 3 , and the labeling results of MDP kit prepared with Tc-99m eluted from PZC-Mo generator and MDP was report as well. ThreeTc-99m generators was prepared with different batches of PZC and reactor irradiated nature Mo. The adsorption efficiency of two batches of the PZC is good (96.4% and 93.4%) and that of one batch of PZC is not satisfy (77.8%). The elution efficiency is not so high, and it increases along with the elution date. The elution file is very broad till to 30 ml and the Mo breakthrough is high to unacceptable. The labelling efficiency of MDP kit, prepared with Tc-99m eluate eluted with saline containing 0.05% NaClO from Mo-PZC generator, is approximately 77∼84% and it can reach to >98% labelling with eluate without containing 0.05%HClO in eluate. (author)

Incorporating high-pressure electroosmotic pump and a nano-flow gradient generator into a miniaturized liquid chromatographic system for peptide analysis.

Science.gov (United States)

Chen, Apeng; Lynch, Kyle B; Wang, Xiaochun; Lu, Joann J; Gu, Congying; Liu, Shaorong

2014-09-24

We integrate a high-pressure electroosmotic pump (EOP), a nanoflow gradient generator, and a capillary column into a miniaturized liquid chromatographic system that can be directly coupled with a mass spectrometer for proteomic analysis. We have recently developed a low-cost high-pressure EOP capable of generating pressure of tens of thousands psi, ideal for uses in miniaturized HPLC. The pump worked smoothly when it was used for isocratic elutions. When it was used for gradient elutions, generating reproducible gradient profiles was challenging; because the pump rate fluctuated when the pump was used to pump high-content organic solvents. This presents an issue for separating proteins/peptides since high-content organic solvents are often utilized. In this work, we solve this problem by incorporating our high-pressure EOP with a nano-flow gradient generator so that the EOP needs only to pump an aqueous solution. With this combination, we develop a capillary-based nano-HPLC system capable of performing nano-flow gradient elution; the pump rate is stable, and the gradient profiles are reproducible and can be conveniently tuned. To demonstrate its utility, we couple it with either a UV absorbance detector or a mass spectrometer for peptide separations. Copyright © 2014. Published by Elsevier B.V.

Ice nucleation rates near ˜225 K

Science.gov (United States)

Amaya, Andrew J.; Wyslouzil, Barbara E.

2018-02-01

We have measured the ice nucleation rates, Jice, in supercooled nano-droplets with radii ranging from 6.6 nm to 10 nm and droplet temperatures, Td, ranging from 225 K to 204 K. The initial temperature of the 10 nm water droplets is ˜250 K, i.e., well above the homogeneous nucleation temperature for micron sized water droplets, TH ˜235 K. The nucleation rates increase systematically from ˜1021 cm-3 s-1 to ˜1022 cm-3 s-1 in this temperature range, overlap with the nucleation rates of Manka et al. [Phys. Chem. Chem. Phys. 14, 4505 (2012)], and suggest that experiments with larger droplets would extrapolate smoothly the rates of Hagen et al. [J. Atmos. Sci. 38, 1236 (1981)]. The sharp corner in the rate data as temperature drops is, however, difficult to match with available theory even if we correct classical nucleation theory and the physical properties of water for the high internal pressure of the nanodroplets.

48 CFR 225.7602 - Procedures.

Science.gov (United States)

2010-10-01

... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Procedures. 225.7602 Section 225.7602 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT OF DEFENSE SOCIOECONOMIC PROGRAMS FOREIGN ACQUISITION Secondary Arab Boycott of Israel 225.7602...

Development of an electron paramagnetic resonance methodology for studying the photo-generation of reactive species in semiconductor nano-particle assembled films

Science.gov (United States)

Twardoch, Marek; Messai, Youcef; Vileno, Bertrand; Hoarau, Yannick; Mekki, Djamel E.; Felix, Olivier; Turek, Philippe; Weiss, Jean; Decher, Gero; Martel, David

2018-06-01

An experimental approach involving electron paramagnetic resonance is proposed for studying photo-generated reactive species in semiconductor nano-particle-based films deposited on the internal wall of glass capillaries. This methodology is applied here to nano-TiO2 and allows a semi-quantitative analysis of the kinetic evolutions of radical production using a spin scavenger probe.

Internal distribution of micro- / nano-sized inorganic particles and their cytocompatibility

Energy Technology Data Exchange (ETDEWEB)

Abe, Shigeaki; Iwadera, Nobuki; Esaki, Mitsue; Kida, Ikuhiro; Akasaka, Tsukasa; Uo, Motohiro; Yawaka, Yasutaka; Watari, Fumio [Graduate School of Dental Medicine, Hokkaido University, Sapporo 060-8586 (Japan); Mutoh, Mami [School of Dental Medicine, Hokkaido University, Sapporo 060-8586 (Japan); Morita, Manabu [Department of Oral Health, Okayama University Graduate School of Medicine, Dentisity and Pharmaceutical Science, Okayama 700-8525 (Japan); Haneda, Koichi [Department of Information Technology and Electronics, Senshu University of Ishinomaki, Ishinomaki 986-8580 (Japan); Yonezawa, Tetsu, E-mail: sabe@den.hokudai.ac.jp [Graduate School of Engineering, Hokkaido University, Sapporo 060-8628 (Japan)

2011-10-29

Nano-sized materials have received much attention lately, both in terms of their multiple applications and their biocompatibility. From both viewpoints, understanding the biodistribution of administered nano-materials is very important. In this study, we succeeded in visualizing the biodistribution of administered nano-materials using a scanning X-ray analytical microscope and magnetic resonance imaging method. Quantitative observation was carried out by inductively coupled plasma - atomic emission spectroscopy. We observed that the administered nano-particles accumulated in the liver, lung and spleen of mice. To estimate their cytocompatibility, the nano-particles were exposed to human liver cells. The results suggested that the micro-/ nano- particles have good cytocompatibility, except for copper oxide nano-particles.

Production and Properties of Nano Fiber (NCC) and Nano Tube (CNT) Reinforced Biodegradable Packaging Films: Effect of Gamma Radiation

International Nuclear Information System (INIS)

Lacroix, Monique; Khan, Ruhul A.; Salmieri, Stephane; Huq, Tanzina; Khan, Avik; Safrany, Agnes

2011-01-01

Biopolymeric (methylcellulose, chitosan and alginate) films were prepared by solution casting and their thermo-mechanical properties were evaluated. Nano crystalline cellulose (NCC) was incorporated into the optimized biopolymeric films. It was found that NCC acted as an excellent reinforcing agent which improved the mechanical properties of the films significantly. The NCC containing biopolymeric films were exposed to gamma radiation (2-25 kGy) and it revealed that biopolymeric films gained strength below 5 kGy dose. Monomer grafting onto the biopolymers were carried out to improve the filler (NCC)-matrix (biopolymers) compatibility. Two monomers (Trimethylol propane tri-methacrylate and 2-Hydroxyethyl methacrylate) were grafted using gamma radiation at 5-25 kGy doses. It was found that monomers were successfully grafted with biopolymers and NCC. Grafted films showed excellent mechanical properties. NCC and carbon nanotubes (CNT) were also incorporated in polycaprolactone-based films prepared by compression molding. It was found that NCC (5% by wt) and CNT (0.2% by wt) improved the mechanical properties of the PCL films significantly. The nano materials containing PCL films were gamma irradiated and found better mechanical and barrier properties. Surface morphology of the nano films was studied by scanning electron microscopy. (author)

Production and Properties of Nano Fiber (NCC) and Nano Tube (CNT) Reinforced Biodegradable Packaging Films: Effect of Gamma Radiation

Energy Technology Data Exchange (ETDEWEB)

Lacroix, Monique; Khan, Ruhul A.; Salmieri, Stephane; Huq, Tanzina; Khan, Avik [INRS-Institut Armand-Frappier, Research Laboratories in Sciences Applied to Food, Canadian Irradiation Center, 531 Boulevard des Prairies, Laval, Quebec, H7V 1B7 (Canada); Safrany, Agnes [International Atomic Energy Agency, Vienna International Centre, A-1400 Vienna (Austria)

2011-07-01

Biopolymeric (methylcellulose, chitosan and alginate) films were prepared by solution casting and their thermo-mechanical properties were evaluated. Nano crystalline cellulose (NCC) was incorporated into the optimized biopolymeric films. It was found that NCC acted as an excellent reinforcing agent which improved the mechanical properties of the films significantly. The NCC containing biopolymeric films were exposed to gamma radiation (2-25 kGy) and it revealed that biopolymeric films gained strength below 5 kGy dose. Monomer grafting onto the biopolymers were carried out to improve the filler (NCC)-matrix (biopolymers) compatibility. Two monomers (Trimethylol propane tri-methacrylate and 2-Hydroxyethyl methacrylate) were grafted using gamma radiation at 5-25 kGy doses. It was found that monomers were successfully grafted with biopolymers and NCC. Grafted films showed excellent mechanical properties. NCC and carbon nanotubes (CNT) were also incorporated in polycaprolactone-based films prepared by compression molding. It was found that NCC (5% by wt) and CNT (0.2% by wt) improved the mechanical properties of the PCL films significantly. The nano materials containing PCL films were gamma irradiated and found better mechanical and barrier properties. Surface morphology of the nano films was studied by scanning electron microscopy. (author)

Dynamics of the amino acid and protein metabolism of laying hens after the application of 15N-labelled wheat protein. 11

International Nuclear Information System (INIS)

Gruhn, K.; Zander, R.

1989-01-01

Over a period of 4 days 12 colostomized laying hens daily received 36 g 15 N-labelled wheat with 15 N excess ( 15 N') of 14.37 atom-% together with a conventional feed mixture for laying hens. The labelling of the lysine N in the wheat was 13.58 atom-%, that of histidine N 14.38 and that of arginine 15 N' 13.63 atom-% 15 N'. Three hens each were butchered 12, 36, 60 and 108 h after the last 15 N' feeding. The first three hens did not receive any feed before being butchered. The following three hens each received the unlabelled feed ration for another 1, 2 or 4 days, resp., after the main period until they were butchered. The total of skeleton muscles, heart and stomach muscle (without inner skin) of each hen were combined into one sample, cut thinly, drenched with fluid nitrogen and pulverized. N, 15 N' and the basic and non-basic amino acids as well as their 15 N' were determined in the individual samples. In contrast to the organs, the proteins in the muscle tissue have a long half-life so that a slight decrease of atom-% 15 N' in the muscles could only be detected after 108 h. The 14 N and 15 N' quota of the non-basic amino acids in the total nitrogen of the muscles is 50 %. The 14 N quota of the basic amino acids is 30% and the 15 N' quota only 22.5% in the total muscle N. The heavy nitrogen of the free lysine in the TCA soluble N fraction is hardly detectable 36 h and 60 h after the last 15 N' supply and not at all after 108 h. In contrast to this, the other two free basic amino acids remain significantly higher labelled in dependence on the last butchering time. (author)

48 CFR 225.7604 - Waivers.

Science.gov (United States)

2010-10-01

... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Waivers. 225.7604 Section 225.7604 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT OF DEFENSE SOCIOECONOMIC PROGRAMS FOREIGN ACQUISITION Secondary Arab Boycott of Israel 225.7604 Waivers. The...

Self-organized titanium oxide nano-channels for resistive memory application

Energy Technology Data Exchange (ETDEWEB)

Barman, A.; Saini, C. P.; Dhar, S.; Kanjilal, A., E-mail: aloke.kanjilal@snu.edu.in [Department of Physics, School of Natural Sciences, Shiv Nadar University, NH-91, Tehsil Dadri, Gautam Buddha Nagar, Uttar Pradesh 201 314 (India); Sarkar, P. [Department of Physics, National Institute of Technology, Silchar, Assam 788 010 (India); Satpati, B.; Bhattacharyya, S. R. [Surface Physics and Material Science Division, Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata 700 064 (India); Kabiraj, D.; Kanjilal, D. [Inter-University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi 110 067 (India)

2015-12-14

Towards developing next generation scalable TiO{sub 2}-based resistive switching (RS) memory devices, the efficacy of 50 keV Ar{sup +}-ion irradiation to achieve self-organized nano-channel based structures at a threshold fluence of 5 × 10{sup 16} ions/cm{sup 2} at ambient temperature is presented. Although x-ray diffraction results suggest the amorphization of as-grown TiO{sub 2} layers, detailed transmission electron microscopy study reveals fluence-dependent evolution of voids and eventual formation of self-organized nano-channels between them. Moreover, gradual increase of TiO/Ti{sub 2}O{sub 3} in the near surface region, as monitored by x-ray photoelectron spectroscopy, establishes the upsurge in oxygen deficient centers. The impact of structural and chemical modification on local RS behavior has also been investigated by current-voltage measurements in conductive atomic force microscopy, while memory application is manifested by fabricating Pt/TiO{sub 2}/Pt/Ti/SiO{sub 2}/Si devices. Finally, the underlying mechanism of our experimental results has been analyzed and discussed in the light of oxygen vacancy migration through nano-channels.

48 CFR 225.504 - Evaluation examples.

Science.gov (United States)

2010-10-01

... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Evaluation examples. 225.504 Section 225.504 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM... 225.504 Evaluation examples. For examples that illustrate the evaluation procedures in 225.502(c)(ii...

Generation of maximally entangled mixed states of two atoms via on-resonance asymmetric atom-cavity couplings

International Nuclear Information System (INIS)

Li, Shang-Bin

2007-01-01

A scheme for generating the maximally entangled mixed state of two atoms on-resonance asymmetrically coupled to a single mode optical cavity field is presented. The part frontier of both maximally entangled mixed states and maximal Bell violating mixed states can be approximately reached by the evolving reduced density matrix of two atoms if the ratio of coupling strengths of two atoms is appropriately controlled. It is also shown that exchange symmetry of global maximal concurrence is broken if and only if coupling strength ratio lies between (√(3)/3) and √(3) for the case of one-particle excitation and asymmetric coupling, while this partial symmetry breaking cannot be verified by detecting maximal Bell violation

Nonlinear atom optics and bright-gap-soliton generation in finite optical lattices

International Nuclear Information System (INIS)

Carusotto, Iacopo; Embriaco, Davide; La Rocca, Giuseppe C.

2002-01-01

We theoretically investigate the transmission dynamics of coherent matter wave pulses across finite optical lattices in both the linear and the nonlinear regimes. The shape and the intensity of the transmitted pulse are found to strongly depend on the parameters of the incident pulse, in particular its velocity and density: a clear physical picture of the main features observed in the numerical simulations is given in terms of the atomic band dispersion in the periodic potential of the optical lattice. Signatures of nonlinear effects due to the atom-atom interaction are discussed in detail, such as atom-optical limiting and atom-optical bistability. For positive scattering lengths, matter waves propagating close to the top of the valence band are shown to be subject to modulational instability. A scheme for the experimental generation of narrow bright gap solitons from a wide Bose-Einstein condensate is proposed: the modulational instability is seeded starting from the strongly modulated density profile of a standing matter wave and the solitonic nature of the generated pulses is checked from their shape and their collisional properties

22 CFR 225.102 - Definitions.

Science.gov (United States)

2010-04-01

... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Definitions. 225.102 Section 225.102 Foreign Relations AGENCY FOR INTERNATIONAL DEVELOPMENT PROTECTION OF HUMAN SUBJECTS § 225.102 Definitions. (a... includes communication or interpersonal contact between investigator and subject. “Private information...

DNA damage due to perfluorooctane sulfonate based on nano-gold embedded in nano-porous poly-pyrrole film

Energy Technology Data Exchange (ETDEWEB)

Lu, Liping, E-mail: lipinglu@bjut.edu.cn; Xu, Laihui; Kang, Tianfang; Cheng, Shuiyuan

2013-11-01

DNA damage induced from perfluorooctane sulfonate (PFOS) was further developed on a nano-porous bionic interface. The interface was formed by assembling DNA on nano-gold particles which were embedded in a nano-porous overoxidized polypyrrole film (OPPy). Atomic force microscopy, scanning electron microscope and electrochemical investigations indicate that OPPy can be treated to form nano-pore structures. DNA damage due to PFOS was proved using electrochemistry and X-ray photoelectron spectroscopy (XPS) and was investigated by detecting differential pulse voltammetry (DPV) response of methylene blue (MB) which was used as electro-active indicator in the system. The current of MB attenuates obviously after incubation of DNA in PFOS. Moreover, electrochemical impedance spectroscopy (EIS) demonstrates that PFOS weakens DNA charge transport. The tentative binding ratio of PFOS: DNA base pair was obtained by analyzing XPS data of this system.

Synthesis of supported metallic nano-particles and their use in air depollution

International Nuclear Information System (INIS)

Barrault, J.; Valange, S.; Tatibouet, J.M.; Thollon, St.; Herlin-Boime, N.; Giraud, S.; Ruiz, J.Ch.; Bergaya, B.; Joulin, J.P.; Delbianco, N.; Gabelica, Z.; Daturi, M.

2009-01-01

The main objectives of the 'NACACOMO' Consortium ('Nano-materials: Catalysts for the Conversion of organic Molecules. Uses in fine chemicals and environment protection ') consisted in generating novel catalysts composed of nanoparticles of metals (Pt, Pd, Ag...) and/or oxides (TiO 2 ...) stabilized and well distributed over the surface of a support (foams, ceramics), by monitoring both the particle size and the 'coating' process itself, using new technologies: CVD, plasma-spray, laser pyrolysis, supercritical preparation, which were compared to conventional soft chemistry recipes. The most accurate characterization of particle morphology, local structure, texture, spatial arrangement but also of their reactivity, were achieved by privileging the utilization of various in situ methods. Details on formation mechanisms of a solid nano-particle at the atomic level (nucleation, growth and particle (re)distribution over the support...) could be obtained in selected cases, with opportunities for scaling up and shaping. The (chemical) nature of the so-obtained nano-materials was monitored for selected catalytic applications involving the development of environmental friendly processes, such as oxidation of VOC, with a priority for aromatics and chlorinated compounds. (authors)

Generation of Exotic Quantum States of a Cold Atomic Ensemble

DEFF Research Database (Denmark)

Christensen, Stefan Lund

Over the last decades quantum effects have become more and more controllable, leading to the implementations of various quantum information protocols. These protocols are all based on utilizing quantum correlation. In this thesis we consider how states of an atomic ensemble with such correlations...... can be created and characterized. First we consider a spin-squeezed state. This state is generated by performing quantum non-demolition measurements of the atomic population difference. We show a spectroscopically relevant noise reduction of -1.7dB, the ensemble is in a many-body entangled state...... — a nanofiber based light-atom interface. Using a dual-frequency probing method we measure and prepare an ensemble with a sub-Poissonian atom number distribution. This is a first step towards the implementation of more exotic quantum states....

Nano materials for Renewable Energy Storage: Synthesis, Characterization, and Applications

International Nuclear Information System (INIS)

Rather, S.U.; Zacharia, R.; Stephan, A.M.; Petrov, L.A.; Nair, J.R.

2015-01-01

Nano technology and nano scale materials have been part of human history and in use since centuries. Staining of glass windows hundreds of years ago is one of the examples where people created beautiful works without knowing that they are using nano processing. The beginning of modern era of nano technology dates back to the talk of the Nobel laureate Professor Richard Feynman in There plenty of room at the bottom. Professor Feynman hypothesized that in near future scientists would be able to control and modulate individual molecules and atoms. After a decade, Professor Norio Taniguchi introduced the magical word nano technology. However, in 1981, the introduction of scanning tunnelling microscope enabled the scientists to see the materials in nano scale that propagated the new age of nano technology.

Ultratrace determination of lead by hydride generation in-atomizer trapping atomic absorption spectrometry: Optimization of plumbane generation and analyte preconcentration in a quartz trap-and-atomizer device

Energy Technology Data Exchange (ETDEWEB)

Kratzer, Jan, E-mail: jkratzer@biomed.cas.cz

2012-05-15

A compact trap-and-atomizer device and a preconcentration procedure based on hydride trapping in excess of oxygen over hydrogen in the collection step, both constructed and developed previously in our laboratory, were employed to optimize plumbane trapping in this device and to develop a routine method for ultratrace lead determination subsequently. The inherent advantage of this preconcentration approach is that 100% preconcentration efficiency for lead is reached in this device which has never been reported before using quartz or metal traps. Plumbane is completely retained in the trap-and-atomizer device at 290 Degree-Sign C in oxygen-rich atmosphere and trapped species are subsequently volatilized at 830 Degree-Sign C in hydrogen-rich atmosphere. Effect of relevant experimental parameters on plumbane trapping and lead volatilization are discussed, and possible trapping mechanisms are hypothesized. Plumbane trapping in the trap-and-atomizer device can be routinely used for lead determination at ultratrace levels reaching a detection limit of 0.21 ng ml{sup -1} Pb (30 s preconcentration, sample volume 2 ml). Further improvement of the detection limit is feasible by reducing the blank signal and increasing the trapping time. - Highlights: Black-Right-Pointing-Pointer In-atomizer trapping HG-AAS was optimized for Pb. Black-Right-Pointing-Pointer A compact quartz trap-and-atomizer device was employed. Black-Right-Pointing-Pointer Generation, preconcentration and atomization steps were investigated in detail. Black-Right-Pointing-Pointer 100% preconcentration efficiency for lead was reached. Black-Right-Pointing-Pointer Routine analytical method was developed for Pb determination (LOD of 0.2 ng ml{sup -1} Pb).

Effect of in ovo supplementation of nano forms of zinc, copper, and selenium on post-hatch performance of broiler chicken

Directory of Open Access Journals (Sweden)

P. Patric Joshua

2016-03-01

Full Text Available Background and Aim: Nanoparticles can bypass conventional physiological ways of nutrient distribution and transport across tissue and cell membranes, as well as protect compounds against destruction prior to reaching their targets. In ovo administration of nanoparticles, may be seen as a new method of nano-nutrition, providing embryos with an additional quantity of nutrients. The aim of the study is to examine the effect of in ovo supplementation of nano forms of zinc, copper and selenium on the hatchability and post hatch performance of broiler chicken. Materials and Methods: Nano form of zinc at 20, 40, 60 and 80 μg/egg, nano form of copper at 4, 8, 12 and 16 μg/egg and nano form of selenium at 0.075, 0.15, 0.225 and 0.3 μg/egg were in ovo supplemented (18th day incubation, amniotic route in fertile broiler eggs. Control group in ovo fed with normal saline alone was also maintained. Each treatment had thirty replicates. Parameters such as hatchability, hatch weight and post hatch performance were studied. Results: In ovo feeding of nano minerals were not harmful to the developing embryo and did not influence the hatchability. Significantly (p<0.05 best feed efficiency for nano forms of zinc (2.16, copper (2.46 and selenium (2.51 were observed, when 40, 4 and 0.225 μg/egg respectively were in ovo supplemented. Except in nano form of copper at 12 μg per egg which had significantly (p<0.05 highest breast muscle percentage there was no distinct trend to indicate that dressing percentage or breast muscle yield was influenced in other treatments. Conclusion: Nano forms of zinc, copper and selenium can be prepared at laboratory conditions. In ovo feeding of nano forms of zinc, copper and selenium at 18th day of incubation through amniotic route does not harm the developing embryo, does not affect hatchability.

Generation of germline ablated male pigs by CRISPR/Cas9 editing of the NANOS2 gene

Science.gov (United States)

Genome editing tools have revolutionized the generation of genetically modified animals including livestock. In particular, the domestic pig is a proven model of human physiology and an agriculturally important species. In this study, we utilized the CRISPR/Cas9 system to edit the NANOS2 gene in p...

On the Size Dependence of Molar and Specific Properties of Independent Nano-phases and Those in Contact with Other Phases

Science.gov (United States)

Kaptay, George

2018-05-01

Nano-materials are materials with at least one nano-phase. A nano-phase is a phase with at least one of its dimensions below 100 nm. It is shown here that nano-phases have at least 1% of their atoms along their surface layer. The ratio of surface atoms is proportional to the specific surface area of the phase, defined as the ratio of its surface area to its volume. Each specific/molar property has its bulk value and its surface value for the given phase, being always different, as the energetic states of the atoms in the bulk and in the surface layer of a phase are different. The average specific/molar property of a nano-phase is modeled here as a linear combination of the bulk and surface values of the same property, scaled with the ratio of the surface atoms. That makes the performance of all nano-phases proportional to their specific surface area. As the characteristic size of the nano-phase is inversely proportional to its specific surface area, all specific/molar properties of nano-phases are inversely proportional to the characteristic size of the phase. This is applied to the size dependence of the molar Gibbs energy of the nano-phase, which appears to be in agreement with the thermodynamics of Gibbs. This agreement proves the general validity of the present model on the size dependence of the specific/molar properties of independent nano-phases. It is shown that the properties of nano-phases are different for independent nano-phases (surrounded only by their equilibrium vapor phase) and for nano-phases in multi-phase situations, such as a liquid nano-droplet in the sessile drop configuration.

Multiplex PCR, amplicon size and hybridization efficiency on the NanoChip electronic microarray

DEFF Research Database (Denmark)

Børsting, Claus; Sanchez, Juan J; Morling, Niels

2004-01-01

We tested the SNP typing protocol developed for the NanoChip electronic microarray by analyzing the four Y chromosome loci SRY1532, SRY8299, TAT, and 92R7. Amplicons of different lengths containing the same locus were purified and addressed to the NanoChip array and fluorescently labelled reporte...

7 CFR 3052.225 - Sanctions.

Science.gov (United States)

2010-01-01

... 7 Agriculture 15 2010-01-01 2010-01-01 false Sanctions. 3052.225 Section 3052.225 Agriculture Regulations of the Department of Agriculture (Continued) OFFICE OF THE CHIEF FINANCIAL OFFICER, DEPARTMENT OF AGRICULTURE AUDITS OF STATES, LOCAL GOVERNMENTS, AND NON-PROFIT ORGANIZATIONS Audits § 3052.225 Sanctions. No...

7 CFR 225.3 - Administration.

Science.gov (United States)

2010-01-01

... 7 Agriculture 4 2010-01-01 2010-01-01 false Administration. 225.3 Section 225.3 Agriculture... CHILD NUTRITION PROGRAMS SUMMER FOOD SERVICE PROGRAM General § 225.3 Administration. (a) Responsibility within the Department. FNS shall act on behalf of the Department in the administration of the Program. (b...

Nano cobalt oxides for photocatalytic hydrogen production

KAUST Repository

Mangrulkar, Priti A.

2012-07-01

Nano structured metal oxides including TiO 2, Co 3O 4 and Fe 3O 4 have been synthesized and evaluated for their photocatalytic activity for hydrogen generation. The photocatalytic activity of nano cobalt oxide was then compared with two other nano structured metal oxides namely TiO 2 and Fe 3O 4. The synthesized nano cobalt oxide was characterized thoroughly with respect to EDX and TEM. The yield of hydrogen was observed to be 900, 2000 and 8275 mmol h -1 g -1 of photocatalyst for TiO 2, Co 3O 4 and Fe 3O 4 respectively under visible light. It was observed that the hydrogen yield in case of nano cobalt oxide was more than twice to that of TiO 2 and the hydrogen yield of nano Fe 3O 4 was nearly four times as compared to nano Co 3O 4. The influence of various operating parameters in hydrogen generation by nano cobalt oxide was then studied in detail. Copyright © 2012, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.

Mechanism for enhancing biodegradability of antibiotic pharmacy wastewater by in-situ generation of H2O2 and radicals over MnOx/nano-G/2-EAQ/AC cathode

International Nuclear Information System (INIS)

Wang, Wenmei; Yu, Jia; Zou, Jinlong; Yu, Xiujuan

2016-01-01

Highlights: • MnO x /nano-G/2-EAQ/AC is used as cathode for electrochemical advanced oxidation. • 2-EAQ can promote the two-electron reduction of O 2 for enhancing H 2 O 2 generation. • OH generation and electron transmission rate are enhanced by MnO x /nano-G. • Biodegradability of antibiotic pharmacy wastewater is improved from 0.01 to 0.31. • Synergistic effects between MnO x /nano-G and 2-EAQ is indispensable for activity. - Abstract: To improve the oxidation efficiency of cathode in the electrochemical advanced oxidation processes (EAOPs), the manganese oxide/nano-graphite (MnO x /nano-G) was synthesized via a liquid-phase precipitation method. Structure and property of MnO x /nano-G calcined at different temperatures (350, 450 and 550 °C) were investigated. Results showed that nano-G ashing and MnO x agglomeration were happened at 550 °C. MnO x /nano-G calcined at 450 °C was proved to have the highest efficiency for phenol degradation. The valences of Mn in the MnO x /nano-G (450 °C) were +3 (Mn 2 O 3 ) and +4 (MnO 2 ). Activity of the prepared MnO x /nano-G/2-ethylanthraquinone/activated carbon (MnO x /nano-G/2-EAQ/AC) cathode was investigated through evaluating H 2 O 2 and ·OH yields, phenol degradation with scavengers, and impedances. 2-EAQ and MnO x could promote the two-electron reduction of O 2 (H 2 O 2 ) and the generation of ·OH radicals, respectively. After 6 h electrolysis, the biodegradability (BOD 5 /COD) of antibiotic pharmacy wastewater was improved from 0.01 to 0.31, indicating that MnO x /nano-G/2-EAQ/AC cathode had promise for further application.

Combustion synthesis of CaSc2O4:Ce3+ nano-phosphors in a closed system

International Nuclear Information System (INIS)

Peng Wenfang; Zou Shaoyu; Liu Guanxi; Xiao Quanlan; Zhang Rui; Xie Lijuan; Cao Liwei; Meng Jianxin; Liu Yingliang

2011-01-01

Highlights: → CaSc 2 O 4 :Ce 3+ nano-phosphors can be prepared by a single-step combustion method. → The ignition temperature is the lowest in the combustion synthesis of Ce 3+ /Eu 2+ doped phosphors. → The as-prepared nano-phosphors give a uniform particle size in the range of 15-20 nm and have highly dispersity and fluorescence intensity. → It is a convenient method for preparation of monodispersed oxide nano-phosphors, especially those being sensitive to air at high temperature. - Abstract: The CaSc 2 O 4 :Ce 3+ nano-phosphors were successfully prepared by a single-step combustion method at an ignition temperature as low as 200 deg. C in a closed autoclave using glycine as a fuel and PEG4000 as a dispersant. The samples were characterized by X-ray diffraction (XRD), photoluminescence (PL) spectroscopy, scanning electron microscopy (SEM) and transmission electron microscope (TEM). The results revealed that CaSc 2 O 4 :Ce 3+ nano-phosphors can be conveniently prepared at an ignition temperature as low as 200 deg. C, which was much lower than that in the ordinary combustion methods. The optimized ignition temperature was 220 deg. C. The CaSc 2 O 4 :Ce 3+ nano-phosphors give a uniform particle size in the range of 15-20 nm. The low ignition temperature and the addition of PEG4000 dispersant play important roles in the formation of small sized nanoparticles. The as-prepared nano-phosphors were incompact aggregates, but highly dispersed nano-phosphors can be obtained after further ultrasonic treatment. The CaSc 2 O 4 :Ce 3+ nano-phosphors give satisfactory luminescence characteristic benefiting from the closed circumstance, in which cerium atoms can be isolated from the oxidizing atmosphere and non-fluorescent Ce 4+ ions can be ruled out. The present highly dispersed CaSc 2 O 4 :Ce 3+ nano-phosphors with efficient fluorescence are promising in the field of biological labeling, and the present low temperature combustion method is facile and convenient and can

6. international conference on Nano-technology in Carbon: from synthesis to applications of nano-structured carbon and related materials

International Nuclear Information System (INIS)

2004-01-01

This is the sixth international conference sponsored this year by the French Carbon Group (GFEC), the European Research Group on Nano-tubes GDRE 'Nano-E', in collaboration with the British Carbon Group and the 'Institut des Materiaux Jean Rouxel' (local organizer). The aim of this conference is to promote carbon science in the nano-scale as, for example, nano-structured carbons, nano-tubes, nano-wires, fullerenes, etc. This conference is designed to introduce those with an interest in materials to current research in nano-technology and to bring together research scientists working in various disciplines in the broad area of nano-structured carbons, nano-tubes and fullerene-related nano-structures. Elemental carbon is the simplest exemplar of this nano-technology based on covalent bonding, however other systems (for example containing hetero-atoms) are becoming important from a research point of view, and provide alternative nano-materials with unique properties opening a broad field of applications. Nano-technology requires an understanding of these materials on a structural and textural point of view and this will be the central theme. This year the conference will feature sessions on: S1. Control and synthesis of nano-materials 1.1 Nano-structured carbons: pyrolysis of polymers, activation, templates,... 1.2 Nano-tubes: Catalytic method, HiPCO, graphite vaporization, electrolysis,... 1.3 Fullerenes S2. Chemistry of carbon nano-materials 2.1 Purification of carbon nano-tubes 2.2 Functionalization - Self-assembling S3. Structural characterization S4. Theory and modelling S5. Relationship between structure and properties S6. Applications Water and air purification, Gas and energy storage, Composite materials, Field emission, Nano-electronics, Biotechnology,... S7. Environmental impact. Only one paper concerning carbon under irradiation has been added to the INIS database. (authors)

20 CFR 225.1 - Introduction.

Science.gov (United States)

2010-04-01

... 20 Employees' Benefits 1 2010-04-01 2010-04-01 false Introduction. 225.1 Section 225.1 Employees... DETERMINATIONS General § 225.1 Introduction. This part discusses Primary Insurance Amount, which is referred to... types of earnings. However, the formulas for computing any PIA are prescribed in section 215 of the...

Dielectric barrier discharge plasma atomizer for hydride generation atomic absorption spectrometry-Performance evaluation for selenium

Czech Academy of Sciences Publication Activity Database

Duben, Ondřej; Boušek, J.; Dědina, Jiří; Kratzer, Jan

2015-01-01

Roč. 111, SEP (2015), s. 57-63 ISSN 0584-8547 Grant - others:GA AV ČR(CZ) M200311202 Institutional support: RVO:68081715 Keywords : dielectric barrier discharge * hydride generation-atomic absorption spectrometry * selenium Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 3.289, year: 2015

Mechanical torques generated by optically pumped atomic spin relaxation at surfaces

International Nuclear Information System (INIS)

Herman, R.M.

1982-01-01

It is argued that a valuable method of observing certain types of surface-atom interactions may lie in mechanical torques generated through the spin-orbit relaxation of valence electronic spins of optically pumped atoms at surfaces. The unusual feature of this phenomenon is that the less probable spin-orbit relaxation becomes highly visible as compared with the much more rapid paramagnetic relaxation, because of an enhancement, typically by as much as a factor 10 9 , in the torques delivered to mechanical structures, by virtue of a very large effective moment arm. Spin-orbit relaxation operates through an exchange of translational momentum which, in turn, can be identified with the delivery of a gigantic angular momentum (in units of h) relative to a distant axis about which mechanical motion is referred. The spin-orbit relaxation strongly depends upon the atomic number of the surface atoms and the strength of interaction with the optically pumped atoms. Being dominated by high-atomic-number surface atoms, spin-orbit relaxation rates may not be too strongly influenced by minor surface contamination of lighter-weight optically active atoms

Mechanical torques generated by optically pumped atomic spin relaxation at surfaces

Science.gov (United States)

Herman, R. M.

1982-03-01

It is argued that a valuable method of observing certain types of surface-atom interactions may lie in mechanical torques generated through the spin-orbit relaxation of valence electronic spins of optically pumped atoms at surfaces. The unusual feature of this phenomenon is that the less probable spin-orbit relaxation becomes highly visible as compared with the much more rapid paramagnetic relaxation, because of an enhancement, typically by as much as a factor 109, in the torques delivered to mechanical structures, by virtue of a very large effective moment arm. Spin-orbit relaxation operates through an exchange of translational momentum which, in turn, can be identified with the delivery of a gigantic angular momentum (in units of ℏ) relative to a distant axis about which mechanical motion is referred. The spin-orbit relaxation strongly depends upon the atomic number of the surface atoms and the strength of interaction with the optically pumped atoms. Being dominated by high-atomic-number surface atoms, spin-orbit-relaxation rates may not be too strongly influenced by minor surface contamination of lighter-weight optically active atoms.

Generation of even harmonics in a relativistic laser plasma of atomic clusters

International Nuclear Information System (INIS)

Krainov, V.P.; Rastunkov, V.S.

2004-01-01

It is shown that the irradiation of atomic clusters by a superintense femtosecond laser pulse gives rise to various harmonics of the laser field. They arise as a result of elastic collisions of free electrons with atomic ions inside the clusters in the presence of the laser filed. The yield of even harmonics whose electromagnetic field is transverse is attributed to the relativism of the motion of electrons and the consideration of their drift velocity associated with the internal ionization of atoms and atomic ions of a cluster. These harmonics are emitted in the same direction as odd harmonics. The conductivities and electromagnetic fields of the harmonics are calculated. The generation efficiency of the harmonics slowly decreases as the harmonic number increases. The generation of even harmonics ceases when the drift velocity of electrons becomes equal to zero and only the oscillation velocity of electrons is nonzero. The results can also be applied to the irradiation of solid-state targets inside a skin layer

Generation of four-atom Greenberger—Horn—Zeilinger state via adiabatic passage

International Nuclear Information System (INIS)

Zhang Chun-Ling; Chen Mei-Feng

2013-01-01

We propose a scheme to generate a Greenberger—Horn—Zeilinger (GHZ) state of four atoms trapped in a two-mode optical cavity via an adiabatic passage. The scheme is robust against moderate fluctuations of the experimental parameters. Numerical calculations show that the excited probabilities of both the cavity modes and the atoms are tiny and depend on the pulse peaks of the classical laser fields. For certain decoherence due to the atomic spontaneous emission and the cavity decay, there exits a range of pulse peaks to get a high fidelity. (general)

Highly versatile atomic micro traps generated by multifrequency magnetic field modulation

International Nuclear Information System (INIS)

Courteille, Ph W; Deh, B; Fortagh, J; Guenther, A; Kraft, S; Marzok, C; Slama, S; Zimmermann, C

2006-01-01

We propose the realization of custom-designed adiabatic potentials for cold atoms based on multimode radio frequency radiation in combination with static inhomogeneous magnetic fields. For example, the use of radio frequency combs gives rise to periodic potentials acting as gratings for cold atoms. In strong magnetic field gradients, the lattice constant can be well below 1 μm. By changing the frequencies of the comb in time the gratings can easily be propagated in space, which may prove useful for Bragg scattering atomic matter waves. Furthermore, almost arbitrarily shaped potentials are possible such as disordered potentials on a scale of several 100 nm or lattices with a spatially varying lattice constant. The potentials can be made state selective and, in the case of atomic mixtures, also species selective. This opens new perspectives for generating tailored quantum systems based on ultracold single atoms or degenerate atomic and molecular quantum gases

DyNano-2010, Book of abstracts

International Nuclear Information System (INIS)

Bjoemeholm, O.; Boutu, W.; Gauthier, D.; Xunyou, Ge; Xiaochi, Liu; Carre, B.; Merdji, H.; Winkler, M.; Harnes, J.; Saethre, L.J.; Boerve, K.J.

2012-01-01

The amazing progresses made in the recent years by the instrumentation in terms of spectral brightness of the X-ray sources (new synchrotron radiation facilities, X-ray Free Electron Lasers etc.), detection schemes (multi-channel analysis due to intensive use of position sensitive detectors, time-resolved techniques etc.) and production sources of clusters (pure and mixed, atomic and molecular clusters) and nano-particles permit nowadays highly accurate spectroscopic studies of more and more complex objects. There were dedicated sessions on the following topics: 1) recent progress in Nano-object's investigations, 2) synchrotron radiation based spectroscopic investigations of clusters and nano-particles, 3) Structure and properties of size-selected clusters, 4) electronic and nuclear decay of clusters, 5) new insights in structure and dynamics of complex species, and 6) clusters and nano-particles and new light sources. This document gathers only the abstracts of the papers

[Biomimetic mineralization of rod-like cellulose nano-whiskers and spectrum analysis].

Science.gov (United States)

Qu, Ping; Wang, Xuan; Cui, Xiao-xia; Zhang, Li-ping

2012-05-01

Cellulose nano-whiskers/nano-hydroxyapatite composite was prepared with biomimetic mineralization using rod-like cellulose nano-whiskers as template. The cellulose nano-whiskers and cellulose nano-whiskers/nano-hydroxyapatite composite were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and scanning electron microscope-energy dispersive analysis of X-rays (SEM-EDXA). Variation and distribution of carbon, oxygen, calcium, and phosphorus in the composites were studied. The morphologies and growth mechanism of nano-hydroxyapatite were analyzed. The results showed that nano-hydroxyapatite was formed on the surface of cellulose nano-whiskers; the carbon-oxygen ratio of cellulose nano-whiskers and cellulose nano-whiskers/nano-hydroxyapatite composite was 1.81 and 1.54, respectively; the calcium-phosphorus ratio of the composite was 1.70. The nucleation of nano-hydroxyapatite was around the hydroxyl groups of cellulose nano-whiskers. It is suggested that there is coordination between the hydroxyl groups of cellulose nano-whiskers and calcium ions of nano-hydroxyapatite. The nano-hydroxyapatite can distribute in the matrix of cellulose nano-whiskers. From the atomic force microscope (AFM) images, we can see that the diameter of the spherical nano-hydroxyapatite particles was about 20 nm.

29 CFR 99.225 - Sanctions.

Science.gov (United States)

2010-07-01

... 29 Labor 1 2010-07-01 2010-07-01 true Sanctions. 99.225 Section 99.225 Labor Office of the Secretary of Labor AUDITS OF STATES, LOCAL GOVERNMENTS, AND NON-PROFIT ORGANIZATIONS Audits § 99.225 Sanctions. No audit costs may be charged to Federal awards when audits required by this part have not been...

Atomic force microscopy of starch systems.

Science.gov (United States)

Zhu, Fan

2017-09-22

Atomic force microscopy (AFM) generates information on topography, adhesion, and elasticity of sample surface by touching with a tip. Under suitable experimental settings, AFM can image biopolymers of few nanometers. Starch is a major food and industrial component. AFM has been used to probe the morphology, properties, modifications, and interactions of starches from diverse botanical origins at both micro- and nano-structural levels. The structural information obtained by AFM supports the blocklet structure of the granules, and provides qualitative and quantitative basis for some physicochemical properties of diverse starch systems. It becomes evident that AFM can complement other microscopic techniques to provide novel structural insights for starch systems.

Design, formulation and optimization of novel soft nano-carriers for transdermal olmesartan medoxomil delivery: In vitro characterization and in vivo pharmacokinetic assessment.

Science.gov (United States)

Kamran, Mohd; Ahad, Abdul; Aqil, Mohd; Imam, Syed Sarim; Sultana, Yasmin; Ali, Asgar

2016-05-30

Olmesartan is a hydrophobic antihypertensive drug with a short biological half-life, and low bioavailability, presents a challenge with respect to its oral administration. The objective of the work was to formulate, optimize and evaluate the transdermal potential of novel vesicular nano-invasomes, containing above anti-hypertensive agent. To achieve the above purpose, soft carriers (viz. nano-invasomes) of olmesartan with β-citronellene as potential permeation enhancer were developed and optimized using Box-Behnken design. The physicochemical characteristics e.g., vesicle size, shape, entrapment efficiency and skin permeability of the nano-invasomes formulations were evaluated. The optimized formulation was further evaluated for in vitro drug release, confocal microscopy and in vivo pharmacokinetic study. The optimum nano-invasomes formulation showed vesicles size of 83.35±3.25nm, entrapment efficiency of 65.21±2.25% and transdermal flux of 32.78±0.703 (μg/cm(2)/h) which were found in agreement with the predicted value generated by Box-Behnken design. Confocal laser microscopy of rat skin showed that optimized formulation was eventually distributed and permeated deep into the skin. The pharmacokinetic study presented that transdermal nano-invasomes formulation showed 1.15 times improvement in bioavailability of olmesartan with respect to the control formulation in Wistar rats. It was concluded that the response surfaces estimated by Design Expert(®) illustrated obvious relationship between formulation factors and response variables and nano-invasomes were found to be a proficient carrier system for transdermal delivery of olmesartan. Copyright © 2016 Elsevier B.V. All rights reserved.

Toughening by nano-scaled twin boundaries in nanocrystals

International Nuclear Information System (INIS)

Zhou, Haofei; Qu, Shaoxing; Yang, Wei

2010-01-01

Joint enhancement on strength and toughness provides a cutting-edge research frontier for metals and alloys. Conventional strengthening methods typically lead to suppressed ductility and fracture toughness. In this study, large-scale atomic simulation on the fracture process is performed featuring nanocrystals embedded with nano-scaled twin boundaries (TBs). Four toughening mechanisms by nano-scaled TBs are identified: (i) crack blunting through dislocation accommodation along the nano-scaled TBs; (ii) crack deflection in a manner of intragranular propagation; (iii) daughter crack formation along the nano-scaled TBs that further enhances the toughness and (iv) curved TB planes owing to an excessive pileup of geometrically necessary dislocations. These toughening mechanisms jointly dictate the mechanical behavior of nano-structured materials, and provide insights into the application of nano-scaled TBs with an aim to simultaneously obtain enhanced strength and toughness. New approaches to introduce these coherent internal defects into the nanostructure of crystalline materials are also proposed

Nano materials for Energy and Environmental Applications

International Nuclear Information System (INIS)

Srinivasan, S.; Kannan, A.M.; Kothurkar, N.; Khalil, Y.; Kuravi, S.

2015-01-01

Nano materials enabled technologies have been seamlessly integrated into applications such as aviation and space, chemical industry, optics, solar hydrogen, fuel cell, batteries, sensors, power generation, aeronautic industry, building/construction industry, automotive engineering, consumer electronics, thermoelectric devices, pharmaceuticals, and cosmetic industry. Clean energy and environmental applications often demand the development of novel nano materials that can provide shortest reaction pathways for the enhancement of reaction kinetics. Understanding the physicochemical, structural, microstructural, surface, and interface properties of nano materials is vital for achieving the required efficiency, cycle life, and sustain ability in various technological applications. Nano materials with specific size and shape such as nano tubes, nano fibers/nano wires, nano cones, nano composites, nano rods, nano islands, nanoparticles, nanospheres, and nano shells to provide unique properties can be synthesized by tuning the process conditions.

Generation of multipartite entangled states for chains of atoms in the framework of cavity-QED

Energy Technology Data Exchange (ETDEWEB)

Gonta, Denis

2010-07-07

Cavity quantum electrodynamics is a research field that studies electromagnetic fields in confined spaces and the radiative properties of atoms in such fields. Experimentally, the simplest example of such system is a single atom interacting with modes of a high-finesse resonator. Theoretically, such system bears an excellent framework for quantum information processing in which atoms and light are interpreted as bits of quantum information and their mutual interaction provides a controllable entanglement mechanism. In this thesis, we present several practical schemes for generation of multipartite entangled states for chains of atoms which pass through one or more high-finesse resonators. In the first step, we propose two schemes for generation of one- and two-dimensional cluster states of arbitrary size. These schemes are based on the resonant interaction of a chain of Rydberg atoms with one or more microwave cavities. In the second step, we propose a scheme for generation of multipartite W states. This scheme is based on the off-resonant interaction of a chain of three-level atoms with an optical cavity and a laser beam. We describe in details all the individual steps which are required to realize the proposed schemes and, moreover, we discuss several techniques to reveal the non-classical correlations associated with generated small-sized entangled states. (orig.)

Generation of multipartite entangled states for chains of atoms in the framework of cavity-QED

International Nuclear Information System (INIS)

Gonta, Denis

2010-01-01

Cavity quantum electrodynamics is a research field that studies electromagnetic fields in confined spaces and the radiative properties of atoms in such fields. Experimentally, the simplest example of such system is a single atom interacting with modes of a high-finesse resonator. Theoretically, such system bears an excellent framework for quantum information processing in which atoms and light are interpreted as bits of quantum information and their mutual interaction provides a controllable entanglement mechanism. In this thesis, we present several practical schemes for generation of multipartite entangled states for chains of atoms which pass through one or more high-finesse resonators. In the first step, we propose two schemes for generation of one- and two-dimensional cluster states of arbitrary size. These schemes are based on the resonant interaction of a chain of Rydberg atoms with one or more microwave cavities. In the second step, we propose a scheme for generation of multipartite W states. This scheme is based on the off-resonant interaction of a chain of three-level atoms with an optical cavity and a laser beam. We describe in details all the individual steps which are required to realize the proposed schemes and, moreover, we discuss several techniques to reveal the non-classical correlations associated with generated small-sized entangled states. (orig.)

Metal Oxide Nano structures: Synthesis, Properties, and Applications

International Nuclear Information System (INIS)

Xu, L. H.; Patil, D. S.; Yang, J.; Xiao, J.

2015-01-01

In recent years, nano structured materials have attracted wide attention due to their fascinating optical and electrical properties, which make these materials potentially suitable for applications in electronics, optics, photonics, and sensors. Some metal oxides show a wide variety of morphologies such as nano wires, nano rods, nano tubes, nano rings, and nano belts. Synthesis and investigation of these metal-oxide nano structures are beneficial not only for understanding the fundamental phenomena in low dimensional systems, but also for developing new-generation nano devices with high performance.

Superconducting properties of YBa2Cu3O7−δ films deposited on commercial tape substrates, decorated with Pd or Ta nano-islands

International Nuclear Information System (INIS)

Polat, Ö; Thompson, J R; Leonard, K J; Wee, S H; Christen, D K; Ertuğrul, M; Sinclair, J W; Zuev, Y L; Paranthaman, M P; Aytuğ, T; Xiong, X; Selvamanickam, V

2012-01-01

To obtain an engineered surface for deposition of high-T c superconductors, nanoscale modulations of the surface of the underlying LaMnO 3 (LMO) cap layer is a potential source for generating microstructural defects in YBa 2 Cu 3 O 7−δ (YBCO) films. These defects may improve the flux pinning and consequently increase the critical current density, J c . To provide such nanoscale modulation via a practical and scalable process, palladium (Pd) or tantalum (Ta) nano-islands were deposited using dc-magnetron sputtering on the surface of the cap layer of commercial metal tape templates for second-generation wires. The size and density of these nano-islands can be controlled by changing sputtering conditions such as the power and deposition time. Compared to the reference sample grown on an untreated LMO cap layer, the YBCO films grown on the LMO cap layers with Pd or Ta nano-islands exhibited improved in-field J c performance. Atomic force microscopy and transmission electron microscopy were used to assess the evolving size and density of the nano-islands. (paper)

Deuterium labeled cannabinoids

International Nuclear Information System (INIS)

Driessen, R.A.

1979-01-01

Complex reactions involving ring opening, ring closure and rearrangements hamper complete understanding of the fragmentation processes in the mass spectrometric fragmentation patterns of cannabinoids. Specifically labelled compounds are very powerful tools for obtaining more insight into fragmentation mechanisms and ion structures and therefore the synthesis of specifically deuterated cannabinoids was undertaken. For this, it was necessary to investigate the preparation of cannabinoids, appropriately functionalized for specific introduction of deuterium atom labels. The results of mass spectrometry with these labelled cannabinoids are described. (Auth.)

Atom localization via controlled spontaneous emission in a five-level atomic system

International Nuclear Information System (INIS)

Wang Zhiping; Yu Benli; Zhu Jun; Cao Zhigang; Zhen Shenglai; Wu Xuqiang; Xu Feng

2012-01-01

We investigate the one- and two-dimensional atom localization behaviors via spontaneous emission in a coherently driven five-level atomic system by means of a radio-frequency field driving a hyperfine transition. It is found that the detecting probability and precision of atom localization behaviors can be significantly improved via adjusting the system parameters. More importantly, the two-dimensional atom localization patterns reveal that the maximal probability of finding an atom within the sub-wavelength domain of the standing waves can reach unity when the corresponding conditions are satisfied. As a result, our scheme may be helpful in laser cooling or the atom nano-lithography via atom localization. - Highlights: ► One- and two-dimensional atom localization behaviors via spontaneous emission in five-level atoms are investigated. ► An assisting radio-frequency field is used to control the atom localization behaviors. ► High-precision and high-resolution two-dimensional atom localization can be realized in this scheme.

The Atomic Mass Dependence of Massive Muon Pair Production in 225 GeV/c $\\pi$ - Nucleus Interactions

Energy Technology Data Exchange (ETDEWEB)

Swartz, Morris L. [Chicago U.

1984-03-01

The production of massive muon pairs in 225 GeV/c $\\pi^-$-nucleus interactions has been studied for four nuclear targets. The dependence of the integrated cross section on atomic mass A was measured by comparing the relative cross sections for the targets. If one assumes that the cross section is proportional to $A^{\\alpha}$, a value of a= 1.00±0.06 for muon pair masses between 4.0 GeV/$c^2$ and 8.5 GeV/$c^2$ was obtained. The Drell-Yan model predicts an additional dependence of the cross section on the proton fraction Z/A. If one parametizes the integrated cross I section as a(Z/A)$A^{\\alpha}$ where $\\sigma$(Z/A) is a function of the proton fraction that includes the effects of the Drell-Yan model, Fermi Motion, and secondary pion production, a value of $\\alpha$ = 0.97±0.06 was obtained. The dependence of the muon pair transverse momentum distribution on nuclear size was also investigated. The second moment of the distribution <$P^2_T$> was found to be consistent with being independent of nuclear size. If the dependence of <$P^2_T$> on nuclear size is parametized as <$P^2_T$> = a + b $A^{1/3}$ the coefficient b was found to be less than 0.015 $GeV^2$/$c^2$ with 90% confidence.

The coherence and spectra of a Bose condensate generated by an atomic laser

International Nuclear Information System (INIS)

Kozlovskii, A.V.

2003-01-01

The first-order coherence dynamics of a Bose condensate generated by a cw atomic laser with evaporative cooling is analyzed. For the atomic-laser multimode model, the coherence functions and atomic field spectra are calculated by the master equation technique. Elastic collisions in the trapped atomic gas lead to significant broadening of the atomic laser line, a shift of its center, and a multi peak structure of the spectra. The oscillatory time dynamics of the atomic-field coherence function is studied. For the atomic laser, the free phase diffusion of the field typical of optical lasers, and characterized by monotonically decreasing mean field with a constant mean phase, is absent due to elastic collisions

Hydrogen storage in single-wall carbon nano-tubes by means of laser excitation

International Nuclear Information System (INIS)

Oksengorn, B.

2010-01-01

A new mode for hydrogen adsorption and storage in single-wall carbon nano-tubes is used, on the basis of laser excitation. Remember that this method has been useful to obtain, in the case of the fullerene C 60 , many complex C 60 -atoms or C 60 -molecules, where atoms or molecular particles are trapped inside the C 60 -molecules. We think this method might be important to store many hydrogen molecules inside carbon nano-tubes. (author)

Radiation-induced tritium labelling and product analysis

Energy Technology Data Exchange (ETDEWEB)

Peng, C.T. (California Univ., San Francisco, CA (United States). Dept. of Pharmaceutical Chemistry)

1993-05-01

By-products formed in radiation-induced tritium labelling are identified by co-chromatography with authentic samples or by structure prediction using a quantitative structure-retention index relationship. The by-products, formed from labelling of steroids, polynuclear aromatic hydrocarbons, 7-membered heterocyclic ring structures, 1,4-benzodiazepines, 1-haloalkanes, etc. with activated tritium and adsorbed tritium, are shown to be specifically labelled and anticipated products from known chemical reactions. From analyses of the by-products, one can conclude that the hydrogen abstraction by tritium atoms and the substitution by tritium ions are the mechanisms of labelling. Classification of the tritium labelling methods, on the basis of the type of tritium reagent, clearly shows the active role played by tritium atoms and ions in radiation-induced methods. (author).

Three-dimensional atom localization via probe absorption in a cascade four-level atomic system

Directory of Open Access Journals (Sweden)

Zeng Wei

2018-03-01

Full Text Available For an atomic system with cascade four-level type, a useful scheme about three-dimensional (3D atom localization is proposed. In our scheme the atomic system is coherently controlled by using a radio-frequency field to couple with two-folded levels under the condition of the existence of probe absorption. Our results show that detecting precision of 3D atom localization may be obviously improved by properly adjusting the frequency detuning and strength of the radio-frequency driving field. So our scheme could be helpful to realize 3D atom localization with high-efficiency and high-precision . In the field of laser cooling or the atom nano-lithography, our studies provide potential applications.

Three-dimensional atom localization via probe absorption in a cascade four-level atomic system

Science.gov (United States)

Zeng, Wei; Deng, Li; Chen, Aixi

2018-03-01

For an atomic system with cascade four-level type, a useful scheme about three-dimensional (3D) atom localization is proposed. In our scheme the atomic system is coherently controlled by using a radio-frequency field to couple with two-folded levels under the condition of the existence of probe absorption. Our results show that detecting precision of 3D atom localization may be obviously improved by properly adjusting the frequency detuning and strength of the radio-frequency driving field. So our scheme could be helpful to realize 3D atom localization with high-efficiency and high-precision . In the field of laser cooling or the atom nano-lithography, our studies provide potential applications.

Characterizing reactive oxygen generation and bacterial inactivation by a zerovalent iron-fullerene nano-composite device at neutral pH under UV-A illumination

International Nuclear Information System (INIS)

Erdim, Esra; Badireddy, Appala Raju; Wiesner, Mark R.

2015-01-01

Highlights: • We synthesized a novel ZVI/nC 60 nano-composite device for multi-ROS generation. • O 2 · − (UV-A independent) and 1 O 2 (UV-A dependent) are generated at neutral pH. • At low Fe concentration, ZVI/nC 60 device is a better ROS generator than ZVI alone. • C 60 mediates electron transfer from ZVI surface to dissolved O 2 to produce O 2 · − . • Bacteria are rapidly inactivated by O 2 · − even at low ZVI/nC 60 ratio. - Abstract: A nano-composite device composed of nano-scale zerovalent iron (ZVI) and C 60 fullerene aggregates (ZVI/nC 60 ) was produced via a rapid nucleation method. The device was conceived to deliver reactive oxygen species (ROS) generated by photosensitization and/or electron transfer to targeted contaminants, including waterborne pathogens under neutral pH conditions. Certain variations of the nano-composite were fabricated differing in the amounts of (1) ZVI (0.1 mM and 2 mM) but not nC 60 (2.5 mg-C/L), and (2) nC 60 (0–25 mg-C/L) but not ZVI (0.1 mM). The generation of ROS by the ZVI/nC 60 nano-composites and ZVI nanoparticles was quantified using organic probe compounds. 0.1 mM ZVI/2.5 mg-C/L C 60 generated 3.74-fold higher O 2 · − concentration and also resulted in an additional 2-log inactivation of Pseudomonas aeruginosa when compared to 0.1 mM ZVI (3-log inactivation). 2 mM ZVI/2.5 mg-C/L nC 60 showed negligible improvement over 2 mM ZVI in terms of O 2 · − generation or inactivation. Further, incremental amounts of nC 60 in the range of 0–25 mg-C/L in 0.1 mM ZVI/nC 60 led to increased O 2 · − concentration, independent of UV-A. This study demonstrates that ZVI/nC 60 device delivers (1) enhanced O 2 · − with nC 60 as a mediator for electron transfer, and (2) 1 O 2 (only under UV-A illumination) at neutral pH conditions

Nano-structural characteristics and optical properties of silver chiral nano-flower sculptured thin films

Energy Technology Data Exchange (ETDEWEB)

Savaloni, Hadi, E-mail: savaloni@khayam.ut.ac.ir [Department of Physics, University of Tehran, North-Kargar Street, Tehran (Iran, Islamic Republic of); Haydari-Nasab, Fatemh; Malmir, Mariam [Department of Physics, University of Tehran, North-Kargar Street, Tehran (Iran, Islamic Republic of)

2011-08-15

Silver chiral nano-flowers with 3-, 4- and 5-fold symmetry were produced using oblique angle deposition method in conjunction with the rotation of sample holder with different speeds at different sectors of each revolution corresponding to symmetry order of the acquired nano-flower. Atomic force microscopy (AFM) and field emission scanning electron microscopy (FESEM), were employed to obtain morphology and nano-structure of the films. Optical characteristics of silver chiral nano-flower thin films were obtained using single beam spectrophotometer with both s- and p-polarization incident light at 30{sup o} and 70{sup o} incidence angles and at different azimuthal angles ({phi}). Optical spectra showed both TM (TDM (transverse dipole mode) and TQM (transverse quadruple mode)) and LM (longitudinal mode) Plasmon resonance peaks. For 3- and 4-fold symmetry chiral nano-flowers the s-polarization extinction spectra obtained at different azimuthal angles did not show significant change in the Plasmon peak position while 5-fold symmetry chiral nano-flower showed a completely different behavior, which may be the result of increased surface anisotropy, so when the {phi} angle is changed the s-polarization response from the surface can change more significantly than that for lower symmetries. In general, for 3-, 4- and 5-fold symmetry chiral nano-flowers a sharp peak at lower wavelengths (<450 nm) is observed in the s-polarization spectra, while in addition to this peak a broad peak at longer wavelengths (i.e., LM) observed in the p-polarization spectra, which is more dominant for 70{sup o} incidence angle.

How shall we hand over the atomic energy to the next generation? Publicity activities to the youth

International Nuclear Information System (INIS)

Kudo, Kazuhiko; Kaji, Yoshiyuki; Kumagaya, Akira; Shibata, Toshikazu; Watanabe, Tamaki; Murakami, Masatoshi; Nishina, Kojiro.

1995-01-01

It is important for Atomic Energy Society of Japan which covers the wide fields related to atomic energy to know exactly what the youths who bear the next generation learn about atomic energy and what feeling they have. However, the attitude or the attempt of meeting young generation from such viewpoint was not sufficient so far. In the phenomena of 'away from atomic energy' recently pointed out frequently, the root seems to have existed long ago. In this feature article, from such critical mind, the present status and the plan for hereafter of atomic energy publicity activities for young generation and those concerned to education are made clear. The publicity activities for school education and young generation, the publicity activities for those concerned to education, the questionnaire of the consciousness about energy and environment, the open school activity of Atomic Energy Society of Japan, the nuclear reactor experiment and study for middle and high school teachers, the assembling of simplified GM counters and the experiment of measuring radiation, the activities of Plasnet for young generation and the exercise and seminar on radiation for high school students are reported. Japanese social system is at the root of atomic energy problem, and the effort to improve it contributes to innovate the constitution of whole Japan. (K.I.)

Modified inorganic nanoparticles as vehicles for alpha emitters in radionuclide therapy

International Nuclear Information System (INIS)

Piotrowska, A.; Leszczuk, E.; Koźmiński, P.; Bilewicz, A.; Morgenstern, A.; Bruchertseifer, F.

2014-01-01

The TiO 2 nanoparticles have unique properties like: high specific surface, high affinity for multivalent cations and simple way of synthesis, which are useful in the process of labelling. Commercially available (e.g. P-25 Degussa) and synthesised in our laboratory nanoparticles were used in experiments. The nanoparticles were characterized by TEM, SEM, DLS and NanoSight techniques. In the experiments, two different methods of labeling are tested. The first one was based on the possibility of formation strong bonds with certain cations on the surface of the nanoparticles. In the 65 second one, TiO 2 nanoparticles were doped with 225 Ac during the process of synthesis. In both cases, high yields of labelling (>99%) was obtained. Afterwards, the stability of labelled nanoparticles was examined in 0.9 % NaCl, 10 -3 M EDTA, solutions of biologically active substances (cysteine, glutathione) and human serum. In case of TiO 2 nanoparticles labelled with 225 Ac, which was built in the crystalline structure, the leakage of 225 Ac and its daughter radionuclides was not significant in any of solutions, even when the incubation time was extended to 10 days. In the case of nanoparticles with adsorbed 225 Ac on surface the leakage in serum was slightly higher, but still insignificant. Also the NaA nanozeolite as a carrier for radium radionuclides has been studied. 224 Ra and 225 Ra, the α-particle emitting radionuclides, have been absorbed in the nanometer-sized NaA zeolite through simple ion-exchange. 224,225 Ra-nanozeolites have shown very good stability in solutions containing: physiological salt, EDTA, amino acid and human serum. To make NaA nanozeolite particles dispersed in water their surface has been modified with silane coupling agent containing poly (ethylene glycol) (PEG) molecules. To obtain conjugates specific for receptors on glioma cancer cells short peptide substance P were covalently attached to the PEG-TiO 2 and PEG-nanozeolite surface. The obtained

Semiconductor Nano wires and Nano tubes: From Fundamentals to Diverse Applications

International Nuclear Information System (INIS)

Xiong, Q.; Grimes, C.A.; Zacharias, M.; Morral, A.F.; Hiruma, K.; Shen, G.

2012-01-01

Research in the field of semiconductor nano wires (SNWs) and nano tubes has been progressing into a mature subject with several highly interdisciplinary sub areas such as nano electronics, nano photonics, nano composites, bio sensing, optoelectronics, and solar cells. SNWs represent a unique system with novel properties associated to their one-dimensional (1D) structures. The fundamental physics concerning the formation of discrete 1D subbands, coulomb blockade effects, ballistic transport, and many-body phenomena in 1D nano wires and nano tubes provide a strong platform to explore the various scientific aspects in these nano structures. A rich variety of preparation methods have already been developed for generating well-controlled 1D nano structures and from a broad range of materials. The present special issue focuses on the recent development in the mechanistic understanding of the synthesis, the studies on electrical/optical properties of nano wires and their applications in nano electronics, nano photonics, and solar-energy harvesting. In this special issue, we have several invited review articles and contributed papers that are addressing current status of the fundamental issues related to synthesis and the diverse applications of semiconducting nano wires and nano tubes. One of the papers reviews the progress of the top-down approach of developing silicon-based vertically aligned nano wires to explore novel device architectures and integration schemes for nano electronics and clean energy applications. Another paper reviews the recent developments and experimental evidences of probing the confined optical and acoustic phonon in nonpolar semiconducting (Si and Ge) nano wires using Raman spectroscopy. The paper by K. Hiruma et al. spotlights the III semiconductor nano wires and demonstrates selective-area metal organic vapor phase epitaxy grown GaAs/In(Al)GaAs and InP/InAs/InP nano wires with heterojunctions along their axial and radial directions. The paper

Collisional effects on metastable atom population in vapour generated by electron beam heating

International Nuclear Information System (INIS)

Dikshit, B; Majumder, A; Bhatia, M S; Mago, V K

2008-01-01

The metastable atom population distribution in a free expanding uranium vapour generated by electron beam (e-beam) heating is expected to depart from its original value near the source due to atom-atom collisions and interaction with electrons of the e-beam generated plasma co-expanding with the vapour. To investigate the dynamics of the electron-atom and atom-atom interactions at different e-beam powers (or source temperatures), probing of the atomic population in ground (0 cm -1 ) and 620 cm -1 metastable states of uranium was carried out by the absorption technique using a hollow cathode discharge lamp. The excitation temperature of vapour at a distance ∼30 cm from the source was calculated on the basis of the measured ratio of populations in 620 to 0 cm -1 states and it was found to be much lower than both the source temperature and estimated translational temperature of the vapour that is cooled by adiabatic free expansion. This indicated relaxation of the metastable atoms by collisions with low energy plasma electrons was so significant that it brings the excitation temperature below the translational temperature of the vapour. So, with increase in e-beam power and hence atom density, frequent atom-atom collisions are expected to establish equilibrium between the excitation and translational temperatures, resulting in an increase in the excitation temperature (i.e. heating of vapour). This has been confirmed by analysing the experimentally observed growth pattern of the curve for excitation temperature with e-beam power. From the observed excitation temperature at low e-beam power when atom-atom collisions can be neglected, the total de-excitation cross section for relaxation of the 620 cm -1 state by interaction with low energy electrons was estimated and was found to be ∼10 -14 cm 2 . Finally using this value of cross section, the extent of excitational cooling and heating by electron-atom and atom-atom collisions are described at higher e-beam powers

In situ AFM analysis investigating disassembly of DNA nanoparticles and nano-films.

Science.gov (United States)

Zou, Yi; Wan, Lei; Blacklock, Jenifer; Oupicky, David; Mao, Guangzhao

2013-01-01

Synthetic vector-based gene delivery systems continue to gain strength as viable alternatives to viral vectors due to safety and other concerns. DNA release dynamics is key to the understanding and control of gene delivery from nano-systems. Here we describe atomic force microscope application to the understanding of DNA release dynamics from bioreducible polycation-based nano-systems. The two nano-systems are polyplex nanoparticles and layer-by-layer films.

CO oxidation on Alsbnd Au nano-composite systems

Science.gov (United States)

Rajesh, C.; Majumder, C.

2018-03-01

Using first principles method we report the CO oxidation behaviour of Alsbnd Au nano-composites in three different size ranges: Al6Au8, Al13Au42 and a periodic slab of Alsbnd Au(1 1 1) surface. The clusters prefer enclosed structures with alternating arrangement of Al and Au atoms, maximising Auδ-sbnd Alδ+ bonds. Charge distribution analysis suggests the charge transfer from Al to Au atoms, corroborated by the red shift in the density of states spectrum. Further, CO oxidation on these nano-composite systems was investigated through both Eley - Rideal and Langmuir Hinshelwood mechanism. While, these clusters interact with O2 non-dissociatively with an elongation of the Osbnd O bond, further interaction with CO led to formation of CO2 spontaneously. On contrary, the CO2 evolution by co-adsorption of O2 and CO molecules has a transition state barrier. On the basis of the results it is inferred that nano-composite material of Alsbnd Au shows significant promise toward effective oxidative catalysis.

Ninth international symposium on hot atom chemistry. Abstracts

International Nuclear Information System (INIS)

1977-01-01

Abstracts of the papers presented at the Symposium are compiled. The topics considered were chemical dynamics of high energy reactions, hot atom chemistry in organic compounds of tritium, nitrogen, oxygen, and halogens, theory and chemical dynamics of hot atom reactions as determined by beam studies, solid state reactions of recoil atoms and implanted ions, hot atom chemistry in energy-related research, hot atom chemistry in inorganic compounds of oxygen and tritium, hot positronium chemistry, applied hot atom chemistry in labelling, chemical effects of radioactive decay, decay-induced reactions and excitation labelling, physical methods in hot atom chemistry, and hot atom reactions in radiation and stratospheric chemistry

Micro-hole array fluorescent sensor based on AC-Dielectrophoresis (DEP) for simultaneous analysis of nano-molecules

Science.gov (United States)

Kim, Hye Jin; Kang, Dong-Hoon; Lee, Eunji; Hwang, Kyo Seon; Shin, Hyun-Joon; Kim, Jinsik

2018-02-01

We propose a simple fluorescent bio-chip based on two types of alternative current-dielectrophoretic (AC-DEP) force, attractive (positive DEP) and repulsive (negative DEP) force, for simultaneous nano-molecules analysis. Various radius of micro-holes on the bio-chip are designed to apply the different AC-DEP forces, and the nano-molecules are concentrated inside the micro-hole arrays according to the intensity of the DEP force. The bio-chip was fabricated by Micro Electro Mechanical system (MEMS) technique, and was composed of two layers; a SiO2 layer and Ta/Pt layer were accomplished for an insulation layer and a top electrode with micro-hole arrays to apply electric fields for DEP force, respectively. Each SiO2 and Ta/Pt layers were deposited by thermal oxidation and sputtering, and micro-hole arrays were fabricated with Inductively Coupled Plasma (ICP) etching process. For generation of each positive and negative DEP at micro-holes, we applied two types of sine-wave AC voltage with different frequency range alternately. The intensity of the DEP force was controlled by the radius of the micro-hole and size of nano-molecule, and calculated with COMSOL multi-physics. Three types of nano-molecules labelled with different fluorescent dye were used and the intensity of nano-molecules was examined by the fluorescent optical analysis after applying the DEP force. By analyzing the fluorescent intensities of the nano-molecules, we verify the various nano-molecules in analyte are located successfully inside corresponding micro-holes with different radius according to their size.

Development of 68Ge/68Ga Generator using 30 MeV Cyclotron

International Nuclear Information System (INIS)

Goo, Hur Min; Dae, Yang Seung; Hoon, Park Jeong; Dae, Park Yong; Je, Lee Eun; Bae, Kong Young; Kim, In Jong; Lee, Jin Woo; Hyun, Yu Kook

2012-05-01

The purpose of this research is to develop the 68 Ge/ 68 Ga generator where daughter nuclide 68 Ga can be eluted according to the designated periods from the resin which holds mother nuclide 68 Ge absorbed and to develop the 68 Ga utilization technology. 1. Target development for 68 Ge target and production of 68 Ge - Target designed for 68 Ge production with 30 MeV cyclotron - Target body material evaluation and proton beam irradiation 2. Separation of 68 Ge and development of column material and extraction system for 68 Ge/ 68 Ga separation - Development of 68 Ge separation method from nat Ga target - Development of absorbents for generator using stable isotope 3. Development of 68 Ga labelled radiopharmaceutical - Development of 68 Ga labelled benzamide derivative for diagnosis of melanoma - Development of 68 Ga dendrimer complex using nano-technology 4. Development of shield case for 68 Ge/ 68 Ga generator

Scheme for generating the singlet state of three atoms trapped in distant cavities coupled by optical fibers

Energy Technology Data Exchange (ETDEWEB)

Wang, Dong-Yang [Department of Physics, College of Science, Yanbian University, Yanji, Jilin 133002 (China); Wen, Jing-Ji [College of Foundation Science, Harbin University of Commerce, Harbin, Heilongjiang 150028 (China); Bai, Cheng-Hua; Hu, Shi; Cui, Wen-Xue [Department of Physics, College of Science, Yanbian University, Yanji, Jilin 133002 (China); Wang, Hong-Fu, E-mail: hfwang@ybu.edu.cn [Department of Physics, College of Science, Yanbian University, Yanji, Jilin 133002 (China); Zhu, Ai-Dong [Department of Physics, College of Science, Yanbian University, Yanji, Jilin 133002 (China); Zhang, Shou, E-mail: szhang@ybu.edu.cn [Department of Physics, College of Science, Yanbian University, Yanji, Jilin 133002 (China)

2015-09-15

An effective scheme is proposed to generate the singlet state with three four-level atoms trapped in three distant cavities connected with each other by three optical fibers, respectively. After a series of appropriate atom–cavity interactions, which can be arbitrarily controlled via the selective pairing of Raman transitions and corresponding optical switches, a three-atom singlet state can be successfully generated. The influence of atomic spontaneous decay, photon leakage of cavities and optical fibers on the fidelity of the state is numerically simulated showing that the three-atom singlet state can be generated with high fidelity by choosing the experimental parameters appropriately.

Detection of gas atoms with carbon nanotubes

Science.gov (United States)

Arash, B.; Wang, Q.

2013-01-01

Owning to their unparalleled sensitivity resolution, nanomechanical resonators have excellent capabilities in design of nano-sensors for gas detection. The current challenge is to develop new designs of the resonators for differentiating distinct gas atoms with a recognizably high sensitivity. In this work, the characteristics of impulse wave propagation in carbon nanotube-based sensors are investigated using molecular dynamics simulations to provide a new method for detection of noble gases. A sensitivity index based on wave velocity shifts in a single-walled carbon nanotube, induced by surrounding gas atoms, is defined to explore the efficiency of the nano-sensor. The simulation results indicate that the nano-sensor is able to differentiate distinct noble gases at the same environmental temperature and pressure. The inertia and the strengthening effects by the gases on wave characteristics of carbon nanotubes are particularly discussed, and a continuum mechanics shell model is developed to interpret the effects.

Microfabricated Waveguide Atom Traps.

Energy Technology Data Exchange (ETDEWEB)

Jau, Yuan-Yu [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2017-09-01

A nanoscale , microfabricated waveguide structure can in - principle be used to trap atoms in well - defined locations and enable strong photon-atom interactions . A neutral - atom platform based on this microfabrication technology will be prealigned , which is especially important for quantum - control applications. At present, there is still no reported demonstration of evanescent - field atom trapping using a microfabricated waveguide structure. We described the capabilities established by our team for future development of the waveguide atom - trapping technology at SNL and report our studies to overcome the technical challenges of loading cold atoms into the waveguide atom traps, efficient and broadband optical coupling to a waveguide, and the waveguide material for high - power optical transmission. From the atomic - physics and the waveguide modeling, w e have shown that a square nano-waveguide can be utilized t o achieve better atomic spin squeezing than using a nanofiber for first time.

Formation of DNA-network embedding ferromagnetic Cobalt nano-particles

Science.gov (United States)

Kanki, Teruo; Tanaka, Hidekazu; Shirakawa, Hideaki; Sacho, Yu; Taniguchi, Masateru; Lee, Hea-Yeon; Kawai, Tomoji; Kang, Nam-Jung; Chen, Jinwoo

2002-03-01

Formation of DNA-network embedding ferromagnetic Cobalt nano-particles T. Kanki, Hidekazu. Tanaka, H. Shirakawa, Y. Sacho, M. Taniguchi, H. Lee, T. Kawai The Institute of Scientific and Industrial Research, Osaka University, Japan and Nam-Jung Kang, Jinwoo Chen Korea Advanced Institute of Science and Technology (KAIST), Korea DNA can be regarded as a naturally occurring and highly specific functional biopolymer and as a fine nano-wire. Moreover, it was found that large-scale DNA networks can be fabricated on mica surfaces. By using this network structure, we can expect to construct nano-scale assembly of functional nano particle, for example ferromagnetic Co nano particles, toward nano scale spin-electronics based on DNA circuits. When we formed DNA network by 250mg/ml DNA solution of poly(dG)-poly(dC) including ferromagnetic Co nano particles (diameter of 12nm), we have conformed the DNA network structure embedding Co nano-particles (height of about 12nm) by atomic force microscopy. On the other hand, we used 100mg/ml DNA solution, DNA can not connect each other, and many Co nano-particles exist without being embedded.

RP-UHPLC-UV-ESI-MS/MS analysis of LPMO generated C4-oxidized gluco-oligosaccharides after non-reductive labeling with 2-aminobenzamide.

Science.gov (United States)

Frommhagen, Matthias; van Erven, Gijs; Sanders, Mark; van Berkel, Willem J H; Kabel, Mirjam A; Gruppen, Harry

2017-08-07

Lytic polysaccharide monooxygenases (LPMOs) are able to cleave recalcitrant polysaccharides, such as cellulose, by oxidizing the C1 and/or C4 atoms. The analysis of the resulting products requires a variety of analytical techniques. Up to now, these techniques mainly focused on the identification of non-oxidized and C1-oxidized oligosaccharides. The analysis of C4-oxidized gluco-oligosaccharides is mostly performed by using high pressure anion exchange chromatography (HPAEC). However, the alkaline conditions used during HPAEC analysis lead to tautomerization of C4-oxidized gluco-oligosaccharides, which limits the use of this technique. Here, we describe the use of reverse phase-ultra high performance liquid chromatography (RP-UHPLC) in combination with non-reductive 2-aminobenzamide (2-AB) labeling. Non-reductive 2-AB labeling enabled separation of C4-oxidized gluco-oligosaccharides from their non-oxidized counterparts. Moreover, RP-UHPLC does not require buffered mobile phases, which reduce mass spectrometry (MS) sensitivity. The latter is seen as an advantage over other techniques such as hydrophilic interaction liquid chromatography and porous graphitized carbon coupled to MS. RP-UHPLC coupled to UV detection and mass spectrometry allowed the identification of both labeled non-oxidized and C4-oxidized oligosaccharides. Non-reductive labeling kept the ketone at the C4-position of LPMO oxidized oligosaccharides intact, while selective reducing agents such as sodium triacetoxyborohydride (STAB) reduced this ketone group. Our results show that RP-UHPLC-UV-ESI-MS in combination with non-reductively 2-AB labeling is a suitable technique for the separation and identification of LPMO-generated C4-oxidized gluco-oligosaccharides. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Handling in the Micro/nano-world: haptic device

International Nuclear Information System (INIS)

Nigues, A.

2012-09-01

Synchrotron Radiation and Scanning Probe Microscopy (SPM) are among the most used techniques to study the physical and chemical properties of nano-structures. Coupling these two techniques is a promising path for opening new horizons in the study of nano-sciences. The merge has already proved its potentialities in the frame of the X-tip project where Atomic Force Microscopy (AFM) has been associated with synchrotron radiation X-Ray diffraction to determine the Young's modulus of germanium micro-plots by dynamically indenting the sample while performing diffraction analysis. The configuration used there, however, does not permit three dimension (3D) manipulations of samples. The aim of our nano-manipulator is 3D management of samples with permanent control of the nano-forces exerted on the object while immersed in a scanning beam (X-Ray, e-beams). The first chapter focuses on the sensors with which measure the interactions at a nanometer scale and permit the selection of individual objects. After an overview of the different techniques of micro/nano-manipulation available today (mechanical micro-grippers based on MEMS technology, optic tweezers or grippers based on conventional atomic force microscopy), and considering the constraints imposed by synchrotron experiments, the choice of quartz oscillators (Tuning Forks or Length Extended Resonators (LER)) as sensors is explained. It follows an introduction to Atomic Force Microscopy in general and the description of its association to these oscillators. In the second chapter, the instrumental development of our nano-manipulation station is detailed with particular care on the definition of the geometry of the resonators and related tips for achieving both AFM imaging and gripping of the sample and on the way to control the coarse and ne positioning of the three elements of the nano-manipulator. Finally, the haptic system ERGOS and its coupling with our assembly is described. In the last chapter, two types of

Fabrication of nano-electrode arrays of free-standing carbon nanotubes on nano-patterned substrate by imprint method

Energy Technology Data Exchange (ETDEWEB)

Chang, W.S., E-mail: paul@kimm.re.kr [Department of Nano Mechanics, Korea Institute of Machinery and Materials, 104 Sinseongno, Yuseong-gu Daejeon 305-343 (Korea, Republic of); Kim, J.W. [Gyeongbuk Hybrid Technology Institute, 36 Goeyeon-dong, Yeongcheon, Gyeongbuk 770-170 (Korea, Republic of); Choi, D.G. [Department of Nano Mechanics, Korea Institute of Machinery and Materials, 104 Sinseongno, Yuseong-gu Daejeon 305-343 (Korea, Republic of); Han, C.S. [Gyeongbuk Hybrid Technology Institute, 36 Goeyeon-dong, Yeongcheon, Gyeongbuk 770-170 (Korea, Republic of)

2011-01-15

The synthesis of isolated carbon nanotubes with uniform outer diameters and ordered spacing over wafer-scale areas was investigated for fabrication of nano-electrode arrays on silicon wafers for field emission and sensor devices. Multi-walled carbon nanotubes (MWCNTs) were grown on TiN electrode layer with iron catalyst patterned by nano-imprint lithography (NIL), which allows the precise placement of individual CNTs on a substrate. The proposed techniques, including plasma-enhanced chemical vapor deposition (PECVD) and NIL, are simple, inexpensive, and reproducible methods for fabrication of nano-scale devices in large areas. The catalyst patterns were defined by an array of circles with 200 nm in diameter, and variable lengths of pitch. The nano-patterned master and Fe catalyst were observed with good pattern fidelity over a large area by atomic force microscope (AFM) and scanning electron microscopy (SEM). Nano-electrodes of MWCNTs had diameters ranging from 50 nm to 100 nm and lengths of about 300 nm. Field emission tests showed the reducing ignition voltage as the geometry of nanotube arrays was controlled by catalyst patterning. These results showed a wafer-scale approach to the control of the size, pitch, and position of nano-electrodes of nanotubes for various applications including electron field-emission sources, electrochemical probes, functionalized sensor elements, and so on.

Atomic force microscopy recognition of protein A on Staphylococcus aureus cell surfaces by labelling with IgG-Au conjugates.

Science.gov (United States)

Tatlybaeva, Elena B; Nikiyan, Hike N; Vasilchenko, Alexey S; Deryabin, Dmitri G

2013-01-01

The labelling of functional molecules on the surface of bacterial cells is one way to recognize the bacteria. In this work, we have developed a method for the selective labelling of protein A on the cell surfaces of Staphylococcus aureus by using nanosized immunogold conjugates as cell-surface markers for atomic force microscopy (AFM). The use of 30-nm size Au nanoparticles conjugated with immunoglobulin G (IgG) allowed the visualization, localization and distribution of protein A-IgG complexes on the surface of S. aureus. The selectivity of the labelling method was confirmed in mixtures of S. aureus with Bacillus licheniformis cells, which differed by size and shape and had no IgG receptors on the surface. A preferential binding of the IgG-Au conjugates to S. aureus was obtained. Thus, this novel approach allows the identification of protein A and other IgG receptor-bearing bacteria, which is useful for AFM indication of pathogenic microorganisms in poly-component associations.

Atomic force microscopy recognition of protein A on Staphylococcus aureus cell surfaces by labelling with IgG–Au conjugates

Directory of Open Access Journals (Sweden)

Elena B. Tatlybaeva

2013-11-01

Full Text Available The labelling of functional molecules on the surface of bacterial cells is one way to recognize the bacteria. In this work, we have developed a method for the selective labelling of protein A on the cell surfaces of Staphylococcus aureus by using nanosized immunogold conjugates as cell-surface markers for atomic force microscopy (AFM. The use of 30-nm size Au nanoparticles conjugated with immunoglobulin G (IgG allowed the visualization, localization and distribution of protein A–IgG complexes on the surface of S. aureus. The selectivity of the labelling method was confirmed in mixtures of S. aureus with Bacillus licheniformis cells, which differed by size and shape and had no IgG receptors on the surface. A preferential binding of the IgG–Au conjugates to S. aureus was obtained. Thus, this novel approach allows the identification of protein A and other IgG receptor-bearing bacteria, which is useful for AFM indication of pathogenic microorganisms in poly-component associations.

Atomic force microscopy recognition of protein A on Staphylococcus aureus cell surfaces by labelling with IgG–Au conjugates

Science.gov (United States)

Tatlybaeva, Elena B; Vasilchenko, Alexey S; Deryabin, Dmitri G

2013-01-01

Summary The labelling of functional molecules on the surface of bacterial cells is one way to recognize the bacteria. In this work, we have developed a method for the selective labelling of protein A on the cell surfaces of Staphylococcus aureus by using nanosized immunogold conjugates as cell-surface markers for atomic force microscopy (AFM). The use of 30-nm size Au nanoparticles conjugated with immunoglobulin G (IgG) allowed the visualization, localization and distribution of protein A–IgG complexes on the surface of S. aureus. The selectivity of the labelling method was confirmed in mixtures of S. aureus with Bacillus licheniformis cells, which differed by size and shape and had no IgG receptors on the surface. A preferential binding of the IgG–Au conjugates to S. aureus was obtained. Thus, this novel approach allows the identification of protein A and other IgG receptor-bearing bacteria, which is useful for AFM indication of pathogenic microorganisms in poly-component associations. PMID:24367742

Quantified Differentiation of Surface Topography for Nano-materials As-Obtained from Atomic Force Microscopy Images

Science.gov (United States)

Gupta, Mousumi; Chatterjee, Somenath

2018-04-01

Surface texture is an important issue to realize the nature (crest and trough) of surfaces. Atomic force microscopy (AFM) image is a key analysis for surface topography. However, in nano-scale, the nature (i.e., deflection or crack) as well as quantification (i.e., height or depth) of deposited layers is essential information for material scientist. In this paper, a gradient-based K-means algorithm is used to differentiate the layered surfaces depending on their color contrast of as-obtained from AFM images. A transformation using wavelet decomposition is initiated to extract the information about deflection or crack on the material surfaces from the same images. Z-axis depth analysis from wavelet coefficients provides information about the crack present in the material. Using the above method corresponding surface information for the material is obtained. In addition, the Gaussian filter is applied to remove the unwanted lines, which occurred during AFM scanning. Few known samples are taken as input, and validity of the above approaches is shown.

Co-Labeling for Multi-View Weakly Labeled Learning.

Science.gov (United States)

Xu, Xinxing; Li, Wen; Xu, Dong; Tsang, Ivor W

2016-06-01

It is often expensive and time consuming to collect labeled training samples in many real-world applications. To reduce human effort on annotating training samples, many machine learning techniques (e.g., semi-supervised learning (SSL), multi-instance learning (MIL), etc.) have been studied to exploit weakly labeled training samples. Meanwhile, when the training data is represented with multiple types of features, many multi-view learning methods have shown that classifiers trained on different views can help each other to better utilize the unlabeled training samples for the SSL task. In this paper, we study a new learning problem called multi-view weakly labeled learning, in which we aim to develop a unified approach to learn robust classifiers by effectively utilizing different types of weakly labeled multi-view data from a broad range of tasks including SSL, MIL and relative outlier detection (ROD). We propose an effective approach called co-labeling to solve the multi-view weakly labeled learning problem. Specifically, we model the learning problem on each view as a weakly labeled learning problem, which aims to learn an optimal classifier from a set of pseudo-label vectors generated by using the classifiers trained from other views. Unlike traditional co-training approaches using a single pseudo-label vector for training each classifier, our co-labeling approach explores different strategies to utilize the predictions from different views, biases and iterations for generating the pseudo-label vectors, making our approach more robust for real-world applications. Moreover, to further improve the weakly labeled learning on each view, we also exploit the inherent group structure in the pseudo-label vectors generated from different strategies, which leads to a new multi-layer multiple kernel learning problem. Promising results for text-based image retrieval on the NUS-WIDE dataset as well as news classification and text categorization on several real-world multi

Editorial Emerging Multifunctional Nano structures

International Nuclear Information System (INIS)

Fan, H.; Lu, Y.; Ramanath, G.; Pomposo, J.A.

2009-01-01

The interest in emerging nano structures is growing exponentially since they are promising building blocks for advanced multifunctional nano composites. In recent years, an evolution from the controlled synthesis of individual monodisperse nanoparticles to the tailored preparation of hybrid spherical and also unsymmetrical multiparticle nano structures is clearly observed. As a matter of fact, the field of nano structures built around a nano species such as inside, outside, and next to a nanoparticle is becoming a new evolving area of research and development with potential applications in improved drug delivery systems, innovative magnetic devices, biosensors, and highly efficient catalysts, among several others Emerging nano structures with improved magnetic, conducting and smart characteristics are currently based on the design, synthesis, characterization and modeling of multifunctional nano object-based materials. In fact, core-shell nanoparticles and other related complex nano architectures covering a broad spectrum of materials (from metal and metal oxide to fused carbon, synthetic polymer, and bio polymer structures) to nano structure morphologies (spherical, cylindrical, star-like, etc.) are becoming the main building blocks for next generation of drug delivery systems, advanced sensors and biosensors, or improved nano composites. The five papers presented in this special issue examine the preparation and characterization of emerging multifunctional materials, covering from hybrid asymmetric structures to engineering nano composites.

Cryopreservation of green fluorescent protein (GFP)-labeled primordial germ cells with GFP fused to the 3' untranslated region of the nanos gene by vitrification of Japanese eel (Anguilla japonica) somite stage embryos.

Science.gov (United States)

Kawakami, Y; Ishihara, M; Saito, T; Fujimoto, T; Adachi, S; Arai, K; Yamaha, E

2012-12-01

Primordial germ cells (PGC) are the only cell type in developing embryos with the potential to transmit genetic information to the next generation. In this study, PGC of Japanese eel (Anguilla japonica) were visualized by injection of mRNA synthesized from a construct carrying the green fluorescent protein (GFP) gene fused to the 3' untranslated region of the Japanese eel nanos gene. We investigated the feasibility of cryopreserving Japanese eel PGC by vitrification of dechorionated whole somite stage embryos. The GFP-labeled PGC were rapidly cooled using liquid nitrogen after exposure to a pretreatment solution containing 1.5 M cryoprotectant (methanol, dimethyl sulfoxide, and glycerol for 10 min and ethylene glycol for 10, 20, and 30 min) and a vitrification solution containing 3 M cryoprotectant and 0.5 M sucrose for 1, 5, and 10 min. Ethylene glycerol is an effective cryoprotectant for embryonic cells and shows no evidence of ice formation after thawing. Vitrified and thawed PGC were transplanted into blastula stage embryos from zebrafish (Danio rerio). The GFP-labeled PGC migrated toward the host gonadal ridge, suggesting maintenance of their normal migration motility. These techniques may assist in achieving inter- and intraspecies germ-line chimers using donor Japanese eel PGC.

Impact of Atomic Layer Deposition to NanoPhotonic Structures and Devices: A Review

Directory of Open Access Journals (Sweden)

Muhammad Rizwan eSaleem

2014-10-01

Full Text Available We review the significance of optical thin films by Atomic Layer Deposition (ALD method to fabricate nanophotonic devices and structures. ALD is a versatile technique to deposit functional coatings on reactive surfaces with conformal growth of compound materials, precise thickness control capable of angstrom resolution and coverage of high aspect ratio nanostructures using wide range of materials. ALD has explored great potential in the emerging fields of photonics, plasmonics, nano-biotechnology, and microelectronics. ALD technique uses sequential reactive chemical reactions to saturate a surface with a monolayer by pulsing of a first precursor (metal alkoxides or covalent halides, followed by reaction with second precursor molecules such as water to form the desired compound coatings. The targeted thickness of the desired compound material is controlled by the number of ALD cycles of precursor molecules that ensures the self limiting nature of reactions. The conformal growth and filling of TiO2 and Al2O3 optical material on nanostructures and their resulting optical properties have been described. The low temperature ALD-growth on various replicated sub-wavelength polymeric gratings is discussed.

Organic solvents as interferents in arsenic determination by hydride generation atomic absorption spectrometry with flame atomization

Czech Academy of Sciences Publication Activity Database

Karadjova, I.B.; Lampugnani, L.; Dědina, Jiří; D'Ulivo, A.; Onor, M.; Tsalev, D.L.

2006-01-01

Roč. 61, č. 5 (2006), s. 525-531 ISSN 0584-8547 R&D Projects: GA AV ČR IAA400310507 Institutional research plan: CEZ:AV0Z40310501 Keywords : hydride generation * atomic absorption spectrometry * interferences Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 3.092, year: 2006

49 CFR 192.225 - Welding procedures.

Science.gov (United States)

2010-10-01

... 49 Transportation 3 2010-10-01 2010-10-01 false Welding procedures. 192.225 Section 192.225... BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Welding of Steel in Pipelines § 192.225 Welding procedures. (a) Welding must be performed by a qualified welder in accordance with welding procedures...

25 CFR 225.24 - Environmental studies.

Science.gov (United States)

2010-04-01

... 25 Indians 1 2010-04-01 2010-04-01 false Environmental studies. 225.24 Section 225.24 Indians... SOLID MINERALS AGREEMENTS Minerals Agreements § 225.24 Environmental studies. (a) The Secretary shall ensure that all environmental studies are prepared as required by the National Environmental Policy Act...

48 CFR 225.7102 - Forgings.

Science.gov (United States)

2010-10-01

... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Forgings. 225.7102 Section 225.7102 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT OF... Forgings. ...

Facile synthesis and photoluminescence spectroscopy of 3D-triangular GaN nano prism islands.

Science.gov (United States)

Kumar, Mukesh; Pasha, S K; Shibin Krishna, T C; Singh, Avanish Pratap; Kumar, Pawan; Gupta, Bipin Kumar; Gupta, Govind

2014-08-21

We report a strategy for fabrication of 3D triangular GaN nano prism islands (TGNPI) grown on Ga/Si(553) substrate at low temperature by N2(+) ions implantation using a sputtering gun technique. The annealing of Ga/Si(553) (600 °C) followed by nitridation (2 keV) shows the formation of high quality GaN TGNPI cross-section. TGNPI morphology has been confirmed by atomic force microscopy. Furthermore, these nano prism islands exhibit prominent ultra-violet luminescence peaking at 366 nm upon 325 nm excitation wavelength along with a low intensity yellow luminescence broad peak at 545 nm which characterizes low defects density TGNPI. Furthermore, the time-resolved spectroscopy of luminescent TGNPI in nanoseconds holds promise for its futuristic application in next generation UV-based sensors as well as many portable optoelectronic devices.

Development of nano-particles labeled and enzyme free portable medical sensor

Energy Technology Data Exchange (ETDEWEB)

Uhm, Young Rang; Rhee, Chang Kyu; Lee, Min Ku; Kim, Jae Woo; Park, Jin Ju; Lee, Gung Ku; Lee, Gyoung Ja

2009-06-15

Development of the approach to the creation of new nonenzymatic biosensors based on immunocomplex 'antigen-antibody' using as signal generating compound Protein / Antibodies / Antigens, labeled with nanoparticles of metals, and using carbon containing nanomaterial as a transducer. Antigens of measles, forest-spring encephalitis or samonella serve as model systems. A technology for synthesis of magnetic Fe{sub 3}O{sub 4} nanoparticles with magnetite structure in 'nanoreactors' - inverse micelles - allowing the particle size regulation with in certain limit sand obtaining nanomaterials with reproducible properties was developed. A method for implementation of covered nanoparticles into microorganisms providing sorption of a reproducible number of nanoparticles on the cells was developed. A technology for production of conjugate of nanoparticles covered with polymeric layer with antibodies was developed.

Conditional generation of the Greenberger-Horne-Zeilinger state of four distant atoms via cavity decay

International Nuclear Information System (INIS)

Zou, XuBo; Pahlke, K.; Mathis, W.

2003-01-01

We propose a scheme to generate a four-particle Greenberger-Horne-Zeilinger (GHZ) state of distant atoms that are trapped separately in leaky cavities. This scheme uses cavity decay to inject photons into a setup of optical devices that consist of a symmetric series of beam splitters and photon detectors. Photon detection on the output modes of the beam splitters projects the atom-cavity-system state onto the GHZ state. It is briefly pointed out that this scheme can be extended to generate GHZ states of 4m atoms

Atomic interferometry: construction, characterisation and optimisation of an interferometer. Application to precision measurements

International Nuclear Information System (INIS)

Buechner, Matthias

2010-01-01

This manuscript describes my research activity in atom interferometry. As an introduction to this domain, we have first described some atom interferometers and their applications. We then describe the atom interferometer we have developed in Toulouse. This is a Mach-Zehnder atom interferometer; the atom source is a thermal supersonic lithium beam and atom manipulation is based on laser diffraction in the Bragg regime. This two interferometer arms are spatially separated, with a maximum distance near 100 μm. The interferometer performances are excellent, with a fringe visibility as large as 84.5 % and a high output flux, thus providing a phase sensitivity of 15 mrad √(Hz). We have used this interferometer for several experiments, with a perturbation applied on only one interferometer arm. When the perturbation is an electric field, we thus measure the electric polarizability of lithium, with an uncertainty 3 times smaller than the best previous measurement. When the perturbation is a gas at low density, we measure the complex refraction index of this gas for lithium atomic waves. If the perturbation is a nano-grating, we measure the complex amplitude of the diffraction zeroth order and this amplitude is very sensitive to the van der Waals interaction of the lithium atom with the nano-grating surface. An important part of this manuscript concerns further developments of our activity. We discuss several improvements of the measurement of the electric polarizability of lithium atom and we hope to access to a precision comparable to the one of the best ab initio calculations of this quantity. We plan to detect a new topological phase, predicted by theory in 1993 but never observed. Finally, we are starting the construction of a second generation atom interferometer, with a slow and intense lithium beam. This new source will give a larger signal and a longer interaction time, thus enabling the detection of considerably weaker perturbations: a fascinating possibility

Atomic and molecular manipulation

CERN Document Server

Mayne, Andrew J

2011-01-01

Work with individual atoms and molecules aims to demonstrate that miniaturized electronic, optical, magnetic, and mechanical devices can operate ultimately even at the level of a single atom or molecule. As such, atomic and molecular manipulation has played an emblematic role in the development of the field of nanoscience. New methods based on the use of the scanning tunnelling microscope (STM) have been developed to characterize and manipulate all the degrees of freedom of individual atoms and molecules with an unprecedented precision. In the meantime, new concepts have emerged to design molecules and substrates having specific optical, mechanical and electronic functions, thus opening the way to the fabrication of real nano-machines. Manipulation of individual atoms and molecules has also opened up completely new areas of research and knowledge, raising fundamental questions of "Optics at the atomic scale", "Mechanics at the atomic scale", Electronics at the atomic scale", "Quantum physics at the atomic sca...

10 CFR 600.225 - Program income.

Science.gov (United States)

2010-01-01

... 10 Energy 4 2010-01-01 2010-01-01 false Program income. 600.225 Section 600.225 Energy DEPARTMENT....225 Program income. (a) General. Grantees are encouraged to earn income to defray program costs. Program income includes income from fees for services performed, from the use or rental of real or...

21 CFR 225.110 - Distribution records.

Science.gov (United States)

2010-04-01

...: GENERAL CURRENT GOOD MANUFACTURING PRACTICE FOR MEDICATED FEEDS Records and Reports § 225.110 Distribution records. (a) Distribution records permit the manufacturer to relate complaints to specific batches and/or... 21 Food and Drugs 4 2010-04-01 2010-04-01 false Distribution records. 225.110 Section 225.110 Food...

Hydromagnetic slip flow of water based nano-fluids past a wedge with convective surface in the presence of heat generation (or) absorption

International Nuclear Information System (INIS)

Rahman, M.M.; Al-Lawatia, M.A.; Eltayeb, I.A.; Al-Salti, N.

2012-01-01

Heat transfer characteristics of a two-dimensional steady hydromagnetic slip flow of water based nano-fluids (TiO 2 -water, Al 2 O 3 -water, and Cu-water) over a wedge with convective surface taking into account the effects of heat generation (or absorption) has been investigated numerically. The local similarity solutions are obtained by using very robust computer algebra software MATLAB and presented graphically as well as in a tabular form. The results show that nano-fluid velocity is lower than the velocity of the base fluid and the existence of the nano-fluid leads to the thinning of the hydrodynamic boundary layer. The rate of shear stress is significantly influenced by the surface convection parameter and the slip parameter. It is higher for nano-fluids than the base fluid. The results also show that within the boundary layer the temperature of the nano-fluid is higher than the temperature of the base fluid. The rate of heat transfer is found to increase with the increase of the surface convection and the slip parameters. Addition of nano-particles to the base fluid induces the rate of heat transfer. The rate of heat transfer in the Cu-water nano-fluid is found to be higher than the rate of heat transfer in the TiO 2 -water and Al 2 O 3 -water nano-fluids. (authors)

Optically sensitive devices based on Pt nano particles fabricated by atomic layer deposition and embedded in a dielectric stack

Energy Technology Data Exchange (ETDEWEB)

Mikhelashvili, V.; Padmanabhan, R.; Eisenstein, G. [Electrical Engineering Department, Technion, Haifa 3200 (Israel); Russell Berrie Nanotechnology Institute, Technion, Haifa 3200 (Israel); Meyler, B.; Yofis, S.; Weindling, S.; Salzman, J. [Electrical Engineering Department, Technion, Haifa 3200 (Israel); Atiya, G.; Cohen-Hyams, Z.; Kaplan, W. D. [Department of Material Science and Engineering, Technion, Haifa 3200 (Israel); Russell Berrie Nanotechnology Institute, Technion, Haifa 3200 (Israel); Ankonina, G. [Russell Berrie Nanotechnology Institute, Technion, Haifa 3200 (Israel); Photovoltaic Laboratory, Technion, Haifa 3200 (Israel)

2015-10-07

We report a series of metal insulator semiconductor devices with embedded Pt nano particles (NPs) fabricated using a low temperature atomic layer deposition process. Optically sensitive nonvolatile memory cells as well as optical sensors: (i) varactors, whose capacitance-voltage characteristics, nonlinearity, and peak capacitance are strongly dependent on illumination intensity; (ii) highly linear photo detectors whose responsivity is enhanced due to the Pt NPs. Both single devices and back to back pairs of diodes were used. The different configurations enable a variety of functionalities with many potential applications in biomedical sensing, environmental surveying, simple imagers for consumer electronics and military uses. The simplicity and planar configuration of the proposed devices makes them suitable for standard CMOS fabrication technology.

Optically sensitive devices based on Pt nano particles fabricated by atomic layer deposition and embedded in a dielectric stack

International Nuclear Information System (INIS)

Mikhelashvili, V.; Padmanabhan, R.; Eisenstein, G.; Meyler, B.; Yofis, S.; Weindling, S.; Salzman, J.; Atiya, G.; Cohen-Hyams, Z.; Kaplan, W. D.; Ankonina, G.

2015-01-01

We report a series of metal insulator semiconductor devices with embedded Pt nano particles (NPs) fabricated using a low temperature atomic layer deposition process. Optically sensitive nonvolatile memory cells as well as optical sensors: (i) varactors, whose capacitance-voltage characteristics, nonlinearity, and peak capacitance are strongly dependent on illumination intensity; (ii) highly linear photo detectors whose responsivity is enhanced due to the Pt NPs. Both single devices and back to back pairs of diodes were used. The different configurations enable a variety of functionalities with many potential applications in biomedical sensing, environmental surveying, simple imagers for consumer electronics and military uses. The simplicity and planar configuration of the proposed devices makes them suitable for standard CMOS fabrication technology

The generation of the Greenberger-Horne-Zeilinger state of four distant atoms conditioned on cavity decay

International Nuclear Information System (INIS)

Pahlke, Kai; Zou Xubo; Mathis, Wolfgang

2004-01-01

We show a way to use an optical device set-up to generate the four-particle Greenberger-Horne-Zeilinger (GHZ) state of atoms, which are trapped separately in leaky cavities. Based on cavity decay, photons are transferred from the atom-cavity systems to a symmetric series of beam splitters and photon detectors. The events of photon detection on the output modes of the beam splitters project the state of the atom-cavity systems onto the GHZ state. It is briefly pointed out how this scheme can be extended to generate GHZ states of 4m atoms

Protein-material interactions: From micro-to-nano scale

International Nuclear Information System (INIS)

Tsapikouni, Theodora S.; Missirlis, Yannis F.

2008-01-01

The article presents a survey on the significance of protein-material interactions, the mechanisms which control them and the techniques used for their study. Protein-surface interactions play a key role in regenerative medicine, drug delivery, biosensor technology and chromatography, while it is related to various undesired effects such as biofouling and bio-prosthetic malfunction. Although the effects of protein-surface interaction concern the micro-scale, being sometimes obvious even with bare eyes, they derive from biophysical events at the nano-scale. The sequential steps for protein adsorption involve events at the single biomolecule level and the forces driving or inhibiting protein adsorption act at the molecular level too. Following the scaling of protein-surface interactions, various techniques have been developed for their study both in the micro- and nano-scale. Protein labelling with radioisotopes or fluorescent probes, colorimetric assays and the quartz crystal microbalance were the first techniques used to monitor protein adsorption isotherms, while the surface force apparatus was used to measure the interaction forces between protein layers at the micro-scale. Recently, more elaborate techniques like total internal reflection fluorescence (TIRF), Fourier transform infrared spectroscopy (FTIR), surface plasmon resonance, Raman spectroscopy, ellipsometry and time of flight secondary ion mass spectrometry (ToF-SIMS) have been applied for the investigation of protein density, structure or orientation at the interfaces. However, a turning point in the study of protein interactions with the surfaces was the invention and the wide-spread use of atomic force microscopy (AFM) which can both image single protein molecules on surfaces and directly measure the interaction force

Site-selective substitutional doping with atomic precision on stepped Al (111) surface by single-atom manipulation.

Science.gov (United States)

Chen, Chang; Zhang, Jinhu; Dong, Guofeng; Shao, Hezhu; Ning, Bo-Yuan; Zhao, Li; Ning, Xi-Jing; Zhuang, Jun

2014-01-01

In fabrication of nano- and quantum devices, it is sometimes critical to position individual dopants at certain sites precisely to obtain the specific or enhanced functionalities. With first-principles simulations, we propose a method for substitutional doping of individual atom at a certain position on a stepped metal surface by single-atom manipulation. A selected atom at the step of Al (111) surface could be extracted vertically with an Al trimer-apex tip, and then the dopant atom will be positioned to this site. The details of the entire process including potential energy curves are given, which suggests the reliability of the proposed single-atom doping method.

49 CFR 397.225 - Judicial review.

Science.gov (United States)

2010-10-01

... 49 Transportation 5 2010-10-01 2010-10-01 false Judicial review. 397.225 Section 397.225... MATERIALS; DRIVING AND PARKING RULES Preemption Procedures § 397.225 Judicial review. A party to a proceeding under § 397.205(a), § 397.213(a), or § 397.223(a) may seek review by the appropriate district...

Nitrogen-15 labeling of Crotalaria juncea green manure

International Nuclear Information System (INIS)

Ambrosano, Edmilson Jose; Rossetto, Raffaella; Trivelin, Paulo Cesar Ocheuze; Muraoka, Takashi; Bendassolli, Jose Albertino; Cantarella, Heitor; Ambrosano, Glaucia Maria Bovi; Tamiso, Luciano Grassi; Vieira, Felipe de Campos; Prada Neto, Ithamar

2003-01-01

Most studies dealing with the utilization of 15 N labeled plant material do not present details about the labeling technique. This is especially relevant for legume species since biological nitrogen fixation difficult plant enrichment. A technique was developed for labeling leguminous plant tissue with 15 N to obtain labeled material for nitrogen dynamics studies. Sun hemp (Crotalaria juncea L.) was grown on a Paleudalf, under field conditions. An amount of 58.32 g of urea with 70.57± 0.04 atom % 15 N was sprayed three times on plants grown on eight 6-m2-plots. The labelled material presented 2.412 atom % 15 N in a total dry matter equivalent to 9 Mg ha -1 This degree of enrichment enables the use of the green manure in pot or field experiments requiring 15 N-labeled material. (author)

Atom-Dependent Edge-Enhanced Second-Harmonic Generation on MoS2 Monolayers.

Science.gov (United States)

Lin, Kuang-I; Ho, Yen-Hung; Liu, Shu-Bai; Ciou, Jian-Jhih; Huang, Bo-Ting; Chen, Christopher; Chang, Han-Ching; Tu, Chien-Liang; Chen, Chang-Hsiao

2018-02-14

Edge morphology and lattice orientation of single-crystal molybdenum disulfide (MoS 2 ) monolayers, a transition metal dichalcogenide (TMD), possessing a triangular shape with different edges grown by chemical vapor deposition are characterized by atomic force microscopy and transmission electron microscopy. Multiphoton laser scanning microscopy is utilized to study one-dimensional atomic edges of MoS 2 monolayers with localized midgap electronic states, which result in greatly enhanced optical second-harmonic generation (SHG). Microscopic S-zigzag edge and S-Mo Klein edge (bare Mo atoms protruding from a S-zigzag edge) terminations and the edge-atom dependent resonance energies can therefore be deduced based on SHG images. Theoretical calculations based on density functional theory clearly explain the lower energy of the S-zigzag edge states compared to the corresponding S-Mo Klein edge states. Characterization of the atomic-scale variation of edge-enhanced SHG is a step forward in this full-optical and high-yield technique of atomic-layer TMDs.

Magnetic behavior of Si-Ge bond in SixGe4-x nano-clusters

Science.gov (United States)

Nahali, Masoud; Mehri, Ali

2018-06-01

The structure of SixGe4-x nano-clusters were optimized by MPW1B95 level of theory using MG3S and SDB-aug-cc-PVTZ basis set. The agreement of the calculated ionization and dissociation energies with experimental values validates the reported structures of nano-clusters and justifies the use of hybrid meta density functional method. Since the Si-Si bond is stronger than Si-Ge and Ge-Ge bonds, the Si-Si, Si-Ge, and Ge-Ge diagonal bonds determine the precedence of the stability in these nano-clusters. The hybrid meta density functional calculations were carried out to investigate the adsorption of CO on all possible SixGe4-x nano-clusters. It was found that the silicon atom generally makes a stronger bond with CO than germanium and thereby preferentially affects the shape of structures having higher multiplicity. In Si-Ge structures with higher spin more than 95% of spins accumulate on positions with less bonds to other atoms of the cluster. Through CO adsorption on these clusters bridge structures are made that behave as spin bridge which conduct the spin from the nano-cluster surface to the adsorbate atoms. A better understanding of bridged structures was achieved upon introducing the 'spin bridge' concept. Based on exhaustive spin density analysis, it was found that the reason for the extra negative charge on oxygen in the bridged structures is the relocation of spin from the surface through the bridge.

Nano-photonics: past and present

Science.gov (United States)

Szu, Harold

2010-04-01

Nanotech is at the scale of 10-9 meters, located at the mesocopic transition phase, which can take both classical mechanics (CM) and quantum mechanics (QM) descriptions bridging ten orders of magnitude phenomena, between the microscopic world of a single atom at 10-10 meters with the macroscopic world at meters. However, QM principles aid the understanding of any unusual property at the nanotech level. The other major difference between nano-photonics and other forms of optics is that the nano-scale is not very 'hands on'. For the most part, we will not be able to see the components with our naked eyes, but will be required to use some nanotech imaging tools, as follows:

Radiation induced nano structures

International Nuclear Information System (INIS)

Ibragimova, E.M.; Kalanov, M.U.; Khakimov, Z.

2006-01-01

Full text: Nanometer-size silicon clusters have been attracting much attention due to their technological importance, in particular, as promising building blocks for nano electronic and nano photonic systems. Particularly, silicon wires are of great of interest since they have potential for use in one-dimensional quantum wire high-speed field effect transistors and light-emitting devices with extremely low power consumption. Carbon and metal nano structures are studied very intensely due to wide possible applications. Radiation material sciences have been dealing with sub-micron objects for a long time. Under interaction of high energy particles and ionizing radiation with solids by elastic and inelastic mechanisms, at first point defects are created, then they form clusters, column defects, disordered regions (amorphous colloids) and finally precipitates of another crystal phase in the matrix. Such irradiation induced evolution of structure defects and phase transformations was observed by X-diffraction techniques in dielectric crystals of quartz and corundum, which exist in and crystal modifications. If there is no polymorphism, like in alkali halide crystals, then due to radiolysis halogen atoms are evaporated from the surface that results in non-stoichiometry or accumulated in the pores formed by metal vacancies in the sub-surface layer. Nano-pores are created by intensive high energy particles irradiation at first chaotically and then they are ordered and in part filled by inert gas. It is well-known mechanism of radiation induced swelling and embrittlement of metals and alloys, which is undesirable for construction materials for nuclear reactors. Possible solution of this problem may come from nano-structured materials, where there is neither swelling nor embrittlement at gas absorption due to very low density of the structure, while strength keeps high. This review considers experimental observations of radiation induced nano-inclusions in insulating

Probing individual redox PEGylated gold nanoparticles by electrochemical--atomic force microscopy.

Science.gov (United States)

Huang, Kai; Anne, Agnès; Bahri, Mohamed Ali; Demaille, Christophe

2013-05-28

Electrochemical-atomic force microscopy (AFM-SECM) was used to simultaneously probe the physical and electrochemical properties of individual ~20 nm sized gold nanoparticles functionalized by redox-labeled PEG chains. The redox PEGylated nanoparticles were assembled onto a gold electrode surface, forming a random nanoarray, and interrogated in situ by a combined AFM-SECM nanoelectrode probe. We show that, in this so-called mediator-tethered (Mt) mode, AFM-SECM affords the nanometer resolution required for resolving the position of individual nanoparticles and measuring their size, while simultaneously electrochemically directly contacting the redox-PEG chains they bear. The dual measurement of the size and current response of single nanoparticles uniquely allows the statistical distribution in grafting density of PEG on the nanoparticles to be determined and correlated to the nanoparticle diameter. Moreover, because of its high spatial resolution, Mt/AFM-SECM allows "visualizing" simultaneously but independently the PEG corona and the gold core of individual nanoparticles. Beyond demonstrating the achievement of single-nanoparticle resolution using an electrochemical microscopy technique, the results reported here also pave the way toward using Mt/AFM-SECM for imaging nano-objects bearing any kind of suitably redox-labeled (bio)macromolecules.

Generation of long-living entanglement between two distant three-level atoms in non-Markovian environments.

Science.gov (United States)

Li, Chuang; Yang, Sen; Song, Jie; Xia, Yan; Ding, Weiqiang

2017-05-15

In this paper, a scheme for the generation of long-living entanglement between two distant Λ-type three-level atoms separately trapped in two dissipative cavities is proposed. In this scheme, two dissipative cavities are coupled to their own non-Markovian environments and two three-level atoms are driven by the classical fields. The entangled state between the two atoms is produced by performing Bell state measurement (BSM) on photons leaving the dissipative cavities. Using the time-dependent Schördinger equation, we obtain the analytical results for the evolution of the entanglement. It is revealed that, by manipulating the detunings of classical field, the long-living stationary entanglement between two atoms can be generated in the presence of dissipation.

Graphene–Noble Metal Nano-Composites and Applications for Hydrogen Sensors

Directory of Open Access Journals (Sweden)

Sukumar Basu

2017-10-01

Full Text Available Graphene based nano-composites are relatively new materials with excellent mechanical, electrical, electronic and chemical properties for applications in the fields of electrical and electronic devices, mechanical appliances and chemical gadgets. For all these applications, the structural features associated with chemical bonding that involve other components at the interface need in-depth investigation. Metals, polymers, inorganic fibers and other components improve the properties of graphene when they form a kind of composite structure in the nano-dimensions. Intensive investigations have been carried out globally in this area of research and development. In this article, some salient features of graphene–noble metal interactions and composite formation which improve hydrogen gas sensing properties—like higher and fast response, quick recovery, cross sensitivity, repeatability and long term stability of the sensor devices—are presented. Mostly noble metals are effective for enhancing the sensing performance of the graphene–metal hybrid sensors, due to their superior catalytic activities. The experimental evidence for atomic bonding between metal nano-structures and graphene has been reported in the literature and it is theoretically verified by density functional theory (DFT. Multilayer graphene influences gas sensing performance via intercalation of metal and non-metal atoms through atomic bonding.

Solid state NMR of isotope labelled murine fur: a powerful tool to study atomic level keratin structure and treatment effects

Energy Technology Data Exchange (ETDEWEB)

Wong, Wai Ching Veronica; Narkevicius, Aurimas; Chow, Wing Ying; Reid, David G.; Rajan, Rakesh [University of Cambridge, Department of Chemistry (United Kingdom); Brooks, Roger A. [University of Cambridge, Department of Trauma and Orthopaedic Surgery, Addenbrooke’s Hospital (United Kingdom); Green, Maggie [University of Cambridge, Central Biomedical Resources, School of Clinical Medicine (United Kingdom); Duer, Melinda J., E-mail: mjd13@cam.ac.uk [University of Cambridge, Department of Chemistry (United Kingdom)

2016-10-15

We have prepared mouse fur extensively {sup 13}C,{sup 15}N-labelled in all amino acid types enabling application of 2D solid state NMR techniques which establish covalent and spatial proximities within, and in favorable cases between, residues. {sup 13}C double quantum–single quantum correlation and proton driven spin diffusion techniques are particularly useful for resolving certain amino acid types. Unlike 1D experiments on isotopically normal material, the 2D methods allow the chemical shifts of entire spin systems of numerous residue types to be determined, particularly those with one or more distinctively shifted atoms such as Gly, Ser, Thr, Tyr, Phe, Val, Leu, Ile and Pro. Also the partial resolution of the amide signals into two signal envelopes comprising of α-helical, and β-sheet/random coil components, enables resolution of otherwise overlapped α-carbon signals into two distinct cross peak families corresponding to these respective secondary structural regions. The increase in resolution conferred by extensive labelling offers new opportunities to study the chemical fate and structural environments of specific atom and amino acid types under the influence of commercial processes, and therapeutic or cosmetic treatments.

Prediction of reacting atoms for the major biotransformation reactions of organic xenobiotics.

Science.gov (United States)

Rudik, Anastasia V; Dmitriev, Alexander V; Lagunin, Alexey A; Filimonov, Dmitry A; Poroikov, Vladimir V

2016-01-01

The knowledge of drug metabolite structures is essential at the early stage of drug discovery to understand the potential liabilities and risks connected with biotransformation. The determination of the site of a molecule at which a particular metabolic reaction occurs could be used as a starting point for metabolite identification. The prediction of the site of metabolism does not always correspond to the particular atom that is modified by the enzyme but rather is often associated with a group of atoms. To overcome this problem, we propose to operate with the term "reacting atom", corresponding to a single atom in the substrate that is modified during the biotransformation reaction. The prediction of the reacting atom(s) in a molecule for the major classes of biotransformation reactions is necessary to generate drug metabolites. Substrates of the major human cytochromes P450 and UDP-glucuronosyltransferases from the Biovia Metabolite database were divided into nine groups according to their reaction classes, which are aliphatic and aromatic hydroxylation, N- and O-glucuronidation, N-, S- and C-oxidation, and N- and O-dealkylation. Each training set consists of positive and negative examples of structures with one labelled atom. In the positive examples, the labelled atom is the reacting atom of a particular reaction that changed adjacency. Negative examples represent non-reacting atoms of a particular reaction. We used Labelled Multilevel Neighbourhoods of Atoms descriptors for the designation of reacting atoms. A Bayesian-like algorithm was applied to estimate the structure-activity relationships. The average invariant accuracy of prediction obtained in leave-one-out and 20-fold cross-validation procedures for five human isoforms of cytochrome P450 and all isoforms of UDP-glucuronosyltransferase varies from 0.86 to 0.99 (0.96 on average). We report that reacting atoms may be predicted with reasonable accuracy for the major classes of metabolic reactions

Subsurface defects structural evolution in nano-cutting of single crystal copper

International Nuclear Information System (INIS)

Wang, Quanlong; Bai, Qingshun; Chen, Jiaxuan; Sun, Yazhou; Guo, Yongbo; Liang, Yingchun

2015-01-01

Highlights: • An innovative analysis method is adopted to analyze nano-cutting process accurately. • A characteristic SFT and stair-rod dislocation are found in subsurface defect layer. • The formation mechanism of stair-rod dislocation is investigated. • The local atomic structure of subsurface defects is introduced. - Abstract: In this work, molecular dynamics simulation is performed to study the subsurface defects structural distribution and its evolution during nano-cutting process of single crystal copper. The formation mechanism of chip and machined surface is interviewed by analyzing the dislocation evolution and atomic migration. The centro-symmetry parameter and spherical harmonics method are adopted to characterize the distribution and evolution of the subsurface defect structures and local atomic structures. The results show that stacking faults, dislocation loops, “V-shaped” dislocation loops, and plenty of point defects are formed during the machined surface being formed in shear-slip zone. In subsurface damage layers, stair-rod dislocation, stacking fault tetrahedra, atomic cluster defect, and vacancy defect are formed. And the formation mechanism of stair-rod dislocation is investigated by atomic-scale structure evolution. The local atomic structures of subsurface defects are icosahedrons, hexagonal close packed, body-centered cubic, and defect face center cubic, and the variations of local atomic structures are investigated

Subsurface defects structural evolution in nano-cutting of single crystal copper

Energy Technology Data Exchange (ETDEWEB)

Wang, Quanlong [School of Mechatronics Engineering, Harbin Institute of Technology, Harbin 150001 (China); Center for Precision Engineering, Harbin Institute of Technology, Harbin 150001 (China); Bai, Qingshun [School of Mechatronics Engineering, Harbin Institute of Technology, Harbin 150001 (China); Chen, Jiaxuan, E-mail: wangquanlong0@hit.edu.cn [Center for Precision Engineering, Harbin Institute of Technology, Harbin 150001 (China); Sun, Yazhou [School of Mechatronics Engineering, Harbin Institute of Technology, Harbin 150001 (China); Guo, Yongbo [Center for Precision Engineering, Harbin Institute of Technology, Harbin 150001 (China); Liang, Yingchun [School of Mechatronics Engineering, Harbin Institute of Technology, Harbin 150001 (China)

2015-07-30

Highlights: • An innovative analysis method is adopted to analyze nano-cutting process accurately. • A characteristic SFT and stair-rod dislocation are found in subsurface defect layer. • The formation mechanism of stair-rod dislocation is investigated. • The local atomic structure of subsurface defects is introduced. - Abstract: In this work, molecular dynamics simulation is performed to study the subsurface defects structural distribution and its evolution during nano-cutting process of single crystal copper. The formation mechanism of chip and machined surface is interviewed by analyzing the dislocation evolution and atomic migration. The centro-symmetry parameter and spherical harmonics method are adopted to characterize the distribution and evolution of the subsurface defect structures and local atomic structures. The results show that stacking faults, dislocation loops, “V-shaped” dislocation loops, and plenty of point defects are formed during the machined surface being formed in shear-slip zone. In subsurface damage layers, stair-rod dislocation, stacking fault tetrahedra, atomic cluster defect, and vacancy defect are formed. And the formation mechanism of stair-rod dislocation is investigated by atomic-scale structure evolution. The local atomic structures of subsurface defects are icosahedrons, hexagonal close packed, body-centered cubic, and defect face center cubic, and the variations of local atomic structures are investigated.

NanoPSE: Nanoscience Problem Solving Environment for atomistic electronic structure of semiconductor nanostructures

International Nuclear Information System (INIS)

Jones, Wesley B; Bester, Gabriel; Canning, Andrew; Franceschetti, Alberto; Graf, Peter A; Kim, Kwiseon; Langou, Julien; Wang Linwang; Dongarra, Jack; Zunger, Alex

2005-01-01

Researchers at the National Renewable Energy Laboratory and their collaborators have developed over the past ∼10 years a set of algorithms for an atomistic description of the electronic structure of nanostructures, based on plane-wave pseudopotentials and configurationinteraction. The present contribution describes the first step in assembling these various codes into a single, portable, integrated set of software packages. This package is part of an ongoing research project in the development stage. Components of NanoPSE include codes for atomistic nanostructure generation and passivation, valence force field model for atomic relaxation, code for potential field generation, empirical pseudopotential method solver, strained linear combination of bulk bands method solver, configuration interaction solver for excited states, selection of linear algebra methods, and several inverse band structure solvers. Although not available for general distribution at this time as it is being developed and tested, the design goal of the NanoPSE software is to provide a software context for collaboration. The software package is enabled by fcdev, an integrated collection of best practice GNU software for open source development and distribution augmented to better support FORTRAN

Multipumping flow system for improving hydride generation atomic fluorescence spectrometric determinations

International Nuclear Information System (INIS)

Lopez-Garcia, Ignacio; Ruiz-Alcaraz, Irene; Hernandez-Cordoba, Manuel

2006-01-01

The advantages of using membrane micropumps rather than peristaltic pumps to introduce both sample and reagent solutions for hydride generation atomic fluorescence spectrometry are discussed. Arsenic was used as a test analyte to check the performance of the proposed manifold. Sample and reagent consumption was reduced 8-9 fold compared with continuous mode measurements made with peristaltic pumps, with no deterioration in sensitivity. The calibration graph was linear in the 0.05 to 2.5 μg l -1 As range using peak area as the analytical signal and maximum gain in the detector setting. A limit of detection (3σ) of 0.02 μg l -1 and relative standard deviation values close to 2% for 10 independent measurements of a 1 μg l -1 As solution were obtained. The sampling frequency increased from 45 to 102 h -1 with the subsequent saving in carrier gas used and reduction in wastes generated. The instrumental modification, which could be used for other elements currently determined by atomic fluorescence spectrometry, will permit hydride generators of more reduced dimensions to be constructed

Review—Micro and Nano-Engineering Enabled New Generation of Thermoelectric Generator Devices and Applications

KAUST Repository

Rojas, Jhonathan P.

2017-01-13

As we are advancing our world to smart living, a critical challenge is increasingly pressing - increased energy demand. While we need mega power supplies for running data centers and other emerging applications, we also need instant small- scale power supply for trillions of electronics that we are using and will use in the age of Internet of Things (IoT) and Internet of Everything (IoE). Such power supplies must meet some parallel demands: sufficient energy supply in reliable, safe and affordable manner. In that regard, thermoelectric generators emerge as important renewable energy source with great potential to take advantage of the widely-abundant and normally-wasted thermal energy. Thanks to the advancements of nano-engineered materials, thermoelectric generators\\' (TEG) performance and feasibility are gradually improving. However, still innovative engineering solutions are scarce to sufficiently take the TEG performance and functionalities beyond the status-quo. Opportunities exist to integrate them with emerging fields and technologies such as wearable electronics, bio-integrated systems, cybernetics and others. This review will mainly focus on unorthodox but effective engineering solutions to notch up the overall performance of TEGs and broadening their application base. First, nanotechnology\\'s influence in TEGs\\' development will be introduced, followed by a discussion on how the introduction of mechanically reconfigurable devices can shape up the emerging spectrum of novel TEG technologies. (C) The Author(s) 2017. Published by ECS.

Evaluation of fresh and old eluate of 99Mo/99mTc generators used for labeling of different pharmaceutical kits

International Nuclear Information System (INIS)

Urbano, N.; Chinol, M.; Modoni, S.; Guerra, M.

2005-01-01

Sixty 99 Mo/ 99m Tc wet column generators, loaded with two different 99 Mo activities, were analyzed in order to assess the quality of their eluates. Each elution was used for labeling of different radiopharmaceuticals, in order to evaluate whether 'risky' elutions, namely those performed just after generator delivery and at 72 hours or more from the last elution, could be conveniently employed when fresh available radioactivity is not enough for the planned labeling or when shipping problems arise, or delay in delivery of a new generator occurs. Radiochemical quality control of all radiopharmaceuticals labeled with these elutions was performed. The elutions differed mainly in 99 Tc ground state ( 99g Tc) and amounts of oxidizing impurities. Radiolabeling procedures, however, were not affected, suggesting that these 'risky' elutions might be appropriately used, in 'emergency' conditions, for labeling radiopharmaceuticals although their radiochemical purity control is recommended prior to patient administration. (author)

Track-etch membranes enabled nano-/microtechnology: A review

International Nuclear Information System (INIS)

Chakarvarti, S.K.

2009-01-01

The art and science of fabricating structures with nano-/micrometric dimensions as well as precision is of the immense concern to any one investigating into nano-/microtechnology. The synergetic support of radiation and its potential in combining radiation effects with nano-/micromaterials has been recognized from the very early stages of nano-science research. In the myriad of applications and uses of nano-/microstructures, and nano particles in particular, from filtration, fabrication of biosensors, a chemical catalysis, magnetic structures, nano-electronics, MEMS, mechano-chemical conversion, quantum computing etc to name a few, radiation can play a significant role. One such potential application is track-etch membranes- a spin-off from the matter-radiation interaction. In the recent years, there has been a tremendous leap in the potential applications of metallic as well as non-metallic nano-/microstructures and materials. Nanotechnology has initiated a big hop and appears to be all set for bringing in revolution in the development and advancement of techniques involved in the synthesis and fabrication of sensors and devices. The conventional techniques for fabrication of very low dimensional wires - say quantum wires, include wet chemistry, electron beam lithography, focused ion beam techniques and atomic-beam lithography but for certain drawbacks and problems mentioned further. That has shown the ways for adopting newer alternative approaches which are relatively inexpensive, easier to handle and synergistically adorned with high efficacy. It is now well known that size of the devices and components dictate many unusual traits where quantum effects become more predominant. Quasi-one-dimensional nanostructures and materials like nanowires, fibres, tubules etc, having high aspect ratio would provide unusual and uncommon properties. Some properties like strength and hardness enhancement, dramatic changes in electrical conduction, field-ion-emission through

Track-etch membranes enabled nano-/microtechnology: A review

Energy Technology Data Exchange (ETDEWEB)

Chakarvarti, S.K., E-mail: skchakarvarti@gmail.co [Department of Physics, National Institute of Technology, Institution of National Importance, Kurukshetra 136 119 (India)

2009-10-15

The art and science of fabricating structures with nano-/micrometric dimensions as well as precision is of the immense concern to any one investigating into nano-/microtechnology. The synergetic support of radiation and its potential in combining radiation effects with nano-/micromaterials has been recognized from the very early stages of nano-science research. In the myriad of applications and uses of nano-/microstructures, and nano particles in particular, from filtration, fabrication of biosensors, a chemical catalysis, magnetic structures, nano-electronics, MEMS, mechano-chemical conversion, quantum computing etc to name a few, radiation can play a significant role. One such potential application is track-etch membranes- a spin-off from the matter-radiation interaction. In the recent years, there has been a tremendous leap in the potential applications of metallic as well as non-metallic nano-/microstructures and materials. Nanotechnology has initiated a big hop and appears to be all set for bringing in revolution in the development and advancement of techniques involved in the synthesis and fabrication of sensors and devices. The conventional techniques for fabrication of very low dimensional wires - say quantum wires, include wet chemistry, electron beam lithography, focused ion beam techniques and atomic-beam lithography but for certain drawbacks and problems mentioned further. That has shown the ways for adopting newer alternative approaches which are relatively inexpensive, easier to handle and synergistically adorned with high efficacy. It is now well known that size of the devices and components dictate many unusual traits where quantum effects become more predominant. Quasi-one-dimensional nanostructures and materials like nanowires, fibres, tubules etc, having high aspect ratio would provide unusual and uncommon properties. Some properties like strength and hardness enhancement, dramatic changes in electrical conduction, field-ion-emission through

Nano-islands Based Charge Trapping Memory: A Scalability Study

KAUST Repository

Elatab, Nazek; Saadat, Irfan; Saraswat, Krishna; Nayfeh, Ammar

2017-01-01

Zinc-oxide (ZnO) and zirconia (ZrO2) metal oxides have been studied extensively in the past few decades with several potential applications including memory devices. In this work, a scalability study, based on the ITRS roadmap, is conducted on memory devices with ZnO and ZrO2 nano-islands charge trapping layer. Both nano-islands are deposited using atomic layer deposition (ALD), however, the different sizes, distribution and properties of the materials result in different memory performance. The results show that at the 32-nm node charge trapping memory with 127 ZrO2 nano-islands can provide a 9.4 V memory window. However, with ZnO only 31 nano-islands can provide a window of 2.5 V. The results indicate that ZrO2 nano-islands are more promising than ZnO in scaled down devices due to their higher density, higher-k, and absence of quantum confinement effects.

Nano-islands Based Charge Trapping Memory: A Scalability Study

KAUST Repository

Elatab, Nazek

2017-10-19

Zinc-oxide (ZnO) and zirconia (ZrO2) metal oxides have been studied extensively in the past few decades with several potential applications including memory devices. In this work, a scalability study, based on the ITRS roadmap, is conducted on memory devices with ZnO and ZrO2 nano-islands charge trapping layer. Both nano-islands are deposited using atomic layer deposition (ALD), however, the different sizes, distribution and properties of the materials result in different memory performance. The results show that at the 32-nm node charge trapping memory with 127 ZrO2 nano-islands can provide a 9.4 V memory window. However, with ZnO only 31 nano-islands can provide a window of 2.5 V. The results indicate that ZrO2 nano-islands are more promising than ZnO in scaled down devices due to their higher density, higher-k, and absence of quantum confinement effects.

Exploring electronic structure of one-atom thick polycrystalline graphene films: A nano angle resolved photoemission study

Science.gov (United States)

Avila, José; Razado, Ivy; Lorcy, Stéphane; Fleurier, Romain; Pichonat, Emmanuelle; Vignaud, Dominique; Wallart, Xavier; Asensio, María C.

2013-01-01

The ability to produce large, continuous and defect free films of graphene is presently a major challenge for multiple applications. Even though the scalability of graphene films is closely associated to a manifest polycrystalline character, only a few numbers of experiments have explored so far the electronic structure down to single graphene grains. Here we report a high resolution angle and lateral resolved photoelectron spectroscopy (nano-ARPES) study of one-atom thick graphene films on thin copper foils synthesized by chemical vapor deposition. Our results show the robustness of the Dirac relativistic-like electronic spectrum as a function of the size, shape and orientation of the single-crystal pristine grains in the graphene films investigated. Moreover, by mapping grain by grain the electronic dynamics of this unique Dirac system, we show that the single-grain gap-size is 80% smaller than the multi-grain gap recently reported by classical ARPES. PMID:23942471

Look@NanoSIMS--a tool for the analysis of nanoSIMS data in environmental microbiology.

Science.gov (United States)

Polerecky, Lubos; Adam, Birgit; Milucka, Jana; Musat, Niculina; Vagner, Tomas; Kuypers, Marcel M M

2012-04-01

We describe an open-source freeware programme for high throughput analysis of nanoSIMS (nanometre-scale secondary ion mass spectrometry) data. The programme implements basic data processing and analytical functions, including display and drift-corrected accumulation of scanned planes, interactive and semi-automated definition of regions of interest (ROIs), and export of the ROIs' elemental and isotopic composition in graphical and text-based formats. Additionally, the programme offers new functions that were custom-designed to address the needs of environmental microbiologists. Specifically, it allows manual and automated classification of ROIs based on the information that is derived either from the nanoSIMS dataset itself (e.g. from labelling achieved by halogen in situ hybridization) or is provided externally (e.g. as a fluorescence in situ hybridization image). Moreover, by implementing post-processing routines coupled to built-in statistical tools, the programme allows rapid synthesis and comparative analysis of results from many different datasets. After validation of the programme, we illustrate how these new processing and analytical functions increase flexibility, efficiency and depth of the nanoSIMS data analysis. Through its custom-made and open-source design, the programme provides an efficient, reliable and easily expandable tool that can help a growing community of environmental microbiologists and researchers from other disciplines process and analyse their nanoSIMS data. © 2012 Society for Applied Microbiology and Blackwell Publishing Ltd.

World's largest DC flywheel generator for the toroidal field power supply of JAERI's JFT-2M Tokamak nuclear fusion reactor

International Nuclear Information System (INIS)

Tani, Takashi; Nakanishi, Yuji; Horita, Tsuyoshi; Kawase, Chiharu; Oyabu, Isao; Kishimoto, Takeshi.

1996-01-01

Mitsubishi Electric has delivered the world's largest DC generator for the toroidal field coil power supply of the JFT-2M Tokamak at the Japan Atomic Energy Research Institute. The unit rotates at 225 or 460 rpm, providing a maximum rated output of 2,700 V, 19,000 A and 51.3 MW. The toroidal field is a DC field, so use of a DC generator permits a simpler design consuming less floor space than an AC drive system. The generator was manufactured following extensive studies on commutation, mechanical strength and insulation. (author)

Nano-JASMINE Data Analysis and Publication

Science.gov (United States)

Yamada, Y.; Hara, T.; Yoshioka, S.; Kobayashi, Y.; Gouda, N.; Miyashita, H.; Hatsutori, Y.; Lammers, U.; Michalik, D.

2012-09-01

The core data reduction for the Nano-JASMINE mission is planned to be done with Gaia's Astrometric Global Iterative Solution (AGIS). A collaboration between the Gaia AGIS and Nano-JASMINE teams on the Nano-JASMINE data reduction started in 2007. The Nano-JASMINE team writes codes to generate AGIS input, and this is called Initial Data Treament (IDT). Identification of observed stars and their observed field of view, getting color index, are different from those of Gaia because Nano-JASMINE is ultra small satellite. For converting centroiding results on detector to the celestial sphere, orbit and attitude data of the satellite are used. In Nano-JASMINE, orbit information is derived from on board GPS data and attitude is processed from on-board star sensor data and on-ground Kalman filtering. We also show the Nano-JASMINE goals, status of the data publications and utilizations, and introduce the next Japanese space astrometric mission.

Production of the radiopharmaceuticals labelling albumin nano-colloid with 99mTc for scintiscanning studies of the lymphatic system and bone marrow

International Nuclear Information System (INIS)

Gonzalez Alvarado, Alba Evelia

1997-01-01

The objective of the present work was to carried out the production in Guatemala, of a new radiopharmaceutical in the General Direction of Nuclear Energy for the detection of the cancer, as well as its implementation, the quality control by means of the radiochemical purity, the microbiology control and organoleptic quality , to evaluate the biodistribution in rats and to check its stability. The work was carried out formulating the pharmaco albumin Nano-colloid, then it was labelled with 99m Tc, the radiochemical purity was evaluated, measuring the disintegrations in minutes of the 99m Tc in an scintillation counter type well, being determined the percentage of union from the 99m Tc to the nanocolloid, with a purity bigger than 90%

On the shear strength of tungsten nano-structures with embedded helium

International Nuclear Information System (INIS)

Smirnov, R.D.; Krasheninnikov, S.I.

2013-01-01

Modification of plastic properties of tungsten nano-structures under shear stress load due to embedded helium atoms is studied using molecular dynamics modelling. The modelling demonstrates that the yield strength of tungsten nano-structures reduces significantly with increasing embedded helium concentration. At high helium concentrations (>10 at%), the yield strength decreases to values characteristic to the pressure in helium nano-bubbles, which are formed in tungsten under such conditions and thought to be responsible for the formation of nano-fuzz on tungsten surfaces irradiated with helium plasma. It is also shown that tungsten plastic flow strongly facilitates coagulation of helium clusters to larger bubbles. The temperature dependencies of the yield strength are obtained. (letter)

Cylindrical micelles of a POSS amphiphilic dendrimer as nano-reactors for polymerization.

Science.gov (United States)

Weng, Jing-Ting; Yeh, Tso-Fan; Samuel, Ashok Zachariah; Huang, Yi-Fan; Sie, Jyun-Hao; Wu, Kuan-Yi; Peng, Chi-How; Hamaguchi, Hiro-O; Wang, Chien-Lung

2018-02-15

A low generation amphiphilic dendrimer, POSS-AD, which has a POSS core and eight amphiphilic arms, was synthesized and used as a nano-reactor to produce well-defined polymer nano-cylinders. Confirmed by small-angle X-ray scattering (SAXS), Raman and NMR spectrometry, monodispersed cylindrical micelles that contain a hydrophilic cavity with a diameter of 2.09 nm and a length of 4.26 nm were produced via co-assembling POSS-AD with hydrophilic liquids, such as H 2 O and HEMA in hydrophobic solvents. Taking the HEMA/POSS-AD cylindrical micelles as nano-reactors, polymerization of HEMA within the micelles results in polymer nano-cylinders (POSS-ADNPs) with a diameter of 2.24 nm and a length of 5.02 nm. The study confirmed that despite the inability to maintain specific shape in solution, low generation dendrimers form well-defined nano-containers or nano-reactors, which relies on co-assembling with hydrophilic guest molecules. These nano-reactors are robust enough to maintain their shape during the polymerization of the guest molecules. Polymer nano-cylinders with dimensions less than 10 nm can thus be produced from the HEMA/POSS-AD micelles. Since the chemical structure of low-generation dendrimers and the contents of the co-assembled nano-reactors can be easily adjusted, the concept holds the potential for the further developments of low-generation amphiphilic dendrimers.

Rapid fabrication of an ordered nano-dot array by the combination of nano-plastic forming and annealing methods

International Nuclear Information System (INIS)

Yoshino, Masahiko; Ohsawa, Hiroki; Yamanaka, Akinori

2011-01-01

In this paper, a new fabrication method for an ordered nano-dot array is developed. Combination of coating, nano-plastic forming and annealing processes is studied to produce uniformly sized and ordered gold nano-dot array on a quartz glass substrate. The experimental results reveal that patterning of a groove grid on the gold-coated substrate with NPF is effective to obtain the ordered gold nano-dot array. In the proposed fabrication process, the size of the gold nano-dot can be controlled by adjusting the groove grid size. A minimum gold nano-dot array fabricated on a quartz-glass substrate was 93 nm in diameter and 100 nm in pitch. Furthermore, the mechanism of nano-dot array generation by the presented process is investigated. Using a theoretical model it is revealed that the proposed method is capable of fabrication of smaller nano-dots than 10 nm by controlling process conditions adequately.

Superconducting properties of YaBa₂Cu₃O_7-delta films deposited on commercial tape substrates, decorated with Pd or Ta nano-islands

Energy Technology Data Exchange (ETDEWEB)

Polat, Ozgur [ORNL; Ertugrul, Memhet [Ataturk University; Thompson, James R [ORNL; Leonard, Keith J [ORNL; Sinclair IV, John W [ORNL; Paranthaman, Mariappan Parans [ORNL; Wee, Sung Hun [ORNL; Zuev, Yuri L [ORNL; Xiong, X. [SuperPower Incorporated, Schenectady, New York; Selvamanickam, V. [SuperPower Incorporated, Schenectady, New York; Christen, David K [ORNL; Aytug, Tolga [ORNL

2012-01-01

To obtain an engineered surface for deposition of high-Tc superconductors, nanoscale modulations of the surface of the underlying LaMnO3 (LMO) cap layer is a potential source for generating microstructural defects in YBa2Cu3O7- (YBCO) films. These defects may improve the flux-pinning and consequently increase the critical current density, Jc. To provide such nanoscale modulation via a practical and scalable process, tantalum (Ta) and palladium (Pd) nano-islands were deposited using dc-magnetron sputtering on the surface of the cap layer of commercial metal tape templates for second-generation wires. The size and density of these nano-islands can be controlled by changing sputtering conditions such as the power and deposition time. Compared to the reference sample grown on an untreated LMO cap layer, the YBCO films grown on the LMO cap layers with Ta or Pd nano-islands exhibited improved in-field Jc performance. Atomic Force Microscopy (AFM) and Transmission Electron Microscopy (TEM) were used to assess the evolving size and density of the nano-islands.

Enhancement of iron content in spinach plants stimulated by magnetic nano particles

Energy Technology Data Exchange (ETDEWEB)

Yulianto, Agus; Astuti, Budi; Amalia, Saptaria Rosa [Physics Department, Faculty of Mathematics and Natural Science, Universitas Negeri Semarang (Indonesia)

2016-04-19

In our previous study, the iron content in spinach plants could be detected by magnetic susceptibility values. In the present work, magnetic nano particles were found from the iron sand. The magnetic nano particles are synthesis by using co-precipitation process and sol-gel technique. The stimulation of magnetic nano particles in the plant has been done by the provision of magnetic nano particles in growing media. After certain time, plant samples was characterized using susceptibility-meter MS2B and atomic absorption spectroscopy to measure the magnetic susceptibility and the amount of iron content that absorbed of the plant, respectively. The iron content in the spinach plants was increased when the magnetic nano particles was injected in the growing media.

Instrument platforms for nano liquid chromatography

Czech Academy of Sciences Publication Activity Database

Šesták, Jozef; Moravcová, Dana; Kahle, Vladislav

2015-01-01

Roč. 1421, NOV (2015), s. 2-17 ISSN 0021-9673 R&D Projects: GA MV VG20112015021 Institutional support: RVO:68081715 Keywords : nano liquid chromatography * splitless gradient generation * nano LC platforms Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 3.926, year: 2015 http://hdl.handle.net/11104/0250900

33 CFR 117.225 - Yellow Mill Channel.

Science.gov (United States)

2010-07-01

... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Yellow Mill Channel. 117.225 Section 117.225 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Connecticut § 117.225 Yellow Mill Channel. The...

Vapor generation – atomic spectrometric techniques. Expanding frontiers through specific-species preconcentration. A review

International Nuclear Information System (INIS)

Gil, Raúl A.; Pacheco, Pablo H.; Cerutti, Soledad; Martinez, Luis D.

2015-01-01

This article reviews 120 articles found in SCOPUS and specific Journal cites corresponding to the terms ‘preconcentration’; ‘speciation’; ‘vapor generation techniques’ and ‘atomic spectrometry techniques’ in the last 5 years. - Highlights: • Recent advances in vapor generation and atomic spectrometry were reviewed. • Species-specific preconcentration strategies after and before VG were discussed. • New preconcentration and speciation analysis were evaluated within this framework. - Abstract: We review recent progress in preconcentration strategies associated to vapor generation techniques coupled to atomic spectrometric (VGT-AS) for specific chemical species detection. This discussion focuses on the central role of different preconcentration approaches, both before and after VG process. The former was based on the classical solid phase and liquid–liquid extraction procedures which, aided by automation and miniaturization strategies, have strengthened the role of VGT-AS in several research fields including environmental, clinical, and others. We then examine some of the new vapor trapping strategies (atom-trapping, hydride trapping, cryotrapping) that entail improvements in selectivity through interference elimination, but also they allow reaching ultra-low detection limits for a large number of chemical species generated in conventional VG systems, including complete separation of several species of the same element. This review covers more than 100 bibliographic references from 2009 up to date, found in SCOPUS database and in individual searches in specific journals. We finally conclude by giving some outlook on future directions of this field

Vapor generation – atomic spectrometric techniques. Expanding frontiers through specific-species preconcentration. A review

Energy Technology Data Exchange (ETDEWEB)

Gil, Raúl A.; Pacheco, Pablo H.; Cerutti, Soledad [Área de Química Analítica, Facultad de Química Bioquímica y Farmacia, Universidad Nacional de San Luis, Ciudad de San Luis 5700 (Argentina); Instituto de Química de San Luis, INQUISAL, Centro Científico-Tecnológico de San Luis (CCT-San Luis), Consejo Nacional de Investigaciones Científicas y Universidad Nacional de San Luis, Ciudad de San Luis 5700 (Argentina); Martinez, Luis D., E-mail: ldm@unsl.edu.ar [Área de Química Analítica, Facultad de Química Bioquímica y Farmacia, Universidad Nacional de San Luis, Ciudad de San Luis 5700 (Argentina); Instituto de Química de San Luis, INQUISAL, Centro Científico-Tecnológico de San Luis (CCT-San Luis), Consejo Nacional de Investigaciones Científicas y Universidad Nacional de San Luis, Ciudad de San Luis 5700 (Argentina)

2015-05-22

This article reviews 120 articles found in SCOPUS and specific Journal cites corresponding to the terms ‘preconcentration’; ‘speciation’; ‘vapor generation techniques’ and ‘atomic spectrometry techniques’ in the last 5 years. - Highlights: • Recent advances in vapor generation and atomic spectrometry were reviewed. • Species-specific preconcentration strategies after and before VG were discussed. • New preconcentration and speciation analysis were evaluated within this framework. - Abstract: We review recent progress in preconcentration strategies associated to vapor generation techniques coupled to atomic spectrometric (VGT-AS) for specific chemical species detection. This discussion focuses on the central role of different preconcentration approaches, both before and after VG process. The former was based on the classical solid phase and liquid–liquid extraction procedures which, aided by automation and miniaturization strategies, have strengthened the role of VGT-AS in several research fields including environmental, clinical, and others. We then examine some of the new vapor trapping strategies (atom-trapping, hydride trapping, cryotrapping) that entail improvements in selectivity through interference elimination, but also they allow reaching ultra-low detection limits for a large number of chemical species generated in conventional VG systems, including complete separation of several species of the same element. This review covers more than 100 bibliographic references from 2009 up to date, found in SCOPUS database and in individual searches in specific journals. We finally conclude by giving some outlook on future directions of this field.

Nano-soldering to single atomic layer

Science.gov (United States)

Girit, Caglar O [Berkeley, CA; Zettl, Alexander K [Kensington, CA

2011-10-11

A simple technique to solder submicron sized, ohmic contacts to nanostructures has been disclosed. The technique has several advantages over standard electron beam lithography methods, which are complex, costly, and can contaminate samples. To demonstrate the soldering technique graphene, a single atomic layer of carbon, has been contacted, and low- and high-field electronic transport properties have been measured.

Characterizing reactive oxygen generation and bacterial inactivation by a zerovalent iron-fullerene nano-composite device at neutral pH under UV-A illumination

Energy Technology Data Exchange (ETDEWEB)

Erdim, Esra [Center for the Environmental Implications of NanoTechnology, Duke University, Durham, NC 27708 (United States); Environmental Engineering Department, Marmara University, Istanbul 34469 (Turkey); Badireddy, Appala Raju [Center for the Environmental Implications of NanoTechnology, Duke University, Durham, NC 27708 (United States); Department of Civil and Environmental Engineering, Duke University, Durham, NC 27708 (United States); Wiesner, Mark R., E-mail: wiesner@duke.edu [Department of Civil and Environmental Engineering, Duke University, Durham, NC 27708 (United States); Department of Civil and Environmental Engineering, Duke University, Durham, NC 27708 (United States)

2015-02-11

Highlights: • We synthesized a novel ZVI/nC{sub 60} nano-composite device for multi-ROS generation. • O{sub 2}·{sup −} (UV-A independent) and {sup 1}O{sub 2} (UV-A dependent) are generated at neutral pH. • At low Fe concentration, ZVI/nC{sub 60} device is a better ROS generator than ZVI alone. • C{sub 60} mediates electron transfer from ZVI surface to dissolved O{sub 2} to produce O{sub 2}·{sup −}. • Bacteria are rapidly inactivated by O{sub 2}·{sup −} even at low ZVI/nC{sub 60} ratio. - Abstract: A nano-composite device composed of nano-scale zerovalent iron (ZVI) and C{sub 60} fullerene aggregates (ZVI/nC{sub 60}) was produced via a rapid nucleation method. The device was conceived to deliver reactive oxygen species (ROS) generated by photosensitization and/or electron transfer to targeted contaminants, including waterborne pathogens under neutral pH conditions. Certain variations of the nano-composite were fabricated differing in the amounts of (1) ZVI (0.1 mM and 2 mM) but not nC{sub 60} (2.5 mg-C/L), and (2) nC{sub 60} (0–25 mg-C/L) but not ZVI (0.1 mM). The generation of ROS by the ZVI/nC{sub 60} nano-composites and ZVI nanoparticles was quantified using organic probe compounds. 0.1 mM ZVI/2.5 mg-C/L C{sub 60} generated 3.74-fold higher O{sub 2}·{sup −} concentration and also resulted in an additional 2-log inactivation of Pseudomonas aeruginosa when compared to 0.1 mM ZVI (3-log inactivation). 2 mM ZVI/2.5 mg-C/L nC{sub 60} showed negligible improvement over 2 mM ZVI in terms of O{sub 2}·{sup −} generation or inactivation. Further, incremental amounts of nC{sub 60} in the range of 0–25 mg-C/L in 0.1 mM ZVI/nC{sub 60} led to increased O{sub 2}·{sup −} concentration, independent of UV-A. This study demonstrates that ZVI/nC{sub 60} device delivers (1) enhanced O{sub 2}·{sup −} with nC{sub 60} as a mediator for electron transfer, and (2) {sup 1}O{sub 2} (only under UV-A illumination) at neutral pH conditions.

Experimental studies of laser-generated translationally hot atoms and molecules

International Nuclear Information System (INIS)

Cousins, L.M.

1989-01-01

An important determinant of the outcome of a chemical interaction is the relative translational energy of the partners. This thesis focuses on the generation of translationally energetic atoms and molecules and the role of translational energy in chemical interactions. One set of studies examines the competitive pathways of reactions and energy transfer in hyperthermal collisions of fast H or D atoms with HF. The vibrational excitation of HF or DF is measured using a time- and wavelength-resolved infrared emission technique. The results suggest that different collision geometries can lead to markedly different mechanisms for vibrational excitation. Another set of experiments is performed with a goal to generate a repetitively pulsed source of molecules or atoms with translational energies in the 0.1-10 eV range. A pulsed UV laser is used to excite a molecular film, vaporizing a number of molecules near the surface of the film. The composition and velocity of these molecules are measured by their time-of-flight to a quadrupole mass spectrometer. Kinetic energies in the range of 0.1-10 eV are observed; the energies are continuously variable and the molecules can be repetitively and reproducibly generated. To establish the dynamics of the vaporization, the internal distributions of fast 0.1-0.7 eV NO molecules are measured using a laser multiphoton detection technique. These studies indicate that the translationally hot molecules are ejected rotationally cold, i.e. typically with only 3% of the energy in rotational excitation. The large disequilibrium between translation and rotation suggests that the vaporization occurs by a transient, nonequilibrium heating mechanism coupled with an adiabatic expansion. The result is additionally promising in light of the desire to produce fast beams of molecules with characterizable and narrow internal energy distributions

42 CFR 93.225 - Respondent.

Science.gov (United States)

2010-10-01

... 42 Public Health 1 2010-10-01 2010-10-01 false Respondent. 93.225 Section 93.225 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES HEALTH ASSESSMENTS AND HEALTH EFFECTS STUDIES OF HAZARDOUS SUBSTANCES RELEASES AND FACILITIES PUBLIC HEALTH SERVICE POLICIES ON RESEARCH...

Motion of Adsorbed Nano-Particles on Azobenzene Containing Polymer Films

Directory of Open Access Journals (Sweden)

Sarah Loebner

2016-12-01

Full Text Available We demonstrate in situ recorded motion of nano-objects adsorbed on a photosensitive polymer film. The motion is induced by a mass transport of the underlying photoresponsive polymer material occurring during irradiation with interference pattern. The polymer film contains azobenzene molecules that undergo reversible photoisomerization reaction from trans- to cis-conformation. Through a multi-scale chain of physico-chemical processes, this finally results in the macro-deformations of the film due to the changing elastic properties of polymer. The topographical deformation of the polymer surface is sensitive to a local distribution of the electrical field vector that allows for the generation of dynamic changes in the surface topography during irradiation with different light interference patterns. Polymer film deformation together with the motion of the adsorbed nano-particles are recorded using a homemade set-up combining an optical part for the generation of interference patterns and an atomic force microscope for acquiring the surface deformation. The particles undergo either translational or rotational motion. The direction of particle motion is towards the topography minima and opposite to the mass transport within the polymer film. The ability to relocate particles by photo-induced dynamic topography fluctuation offers a way for a non-contact simultaneous manipulation of a large number of adsorbed particles just in air at ambient conditions.

Generation and amplification of a high-order sideband induced by two-level atoms in a hybrid optomechanical system

Science.gov (United States)

Liu, Zeng-Xing; Xiong, Hao; Wu, Ying

2018-01-01

It is quite important to enhance and control the optomechanically induced high-order sideband generation to achieve low-power optical comb and high-sensitivity sensing with an integrable structure. Here we present and analyze a proposal for enhancement and manipulation of optical nonlinearity and high-order sideband generation in a hybrid atom-cavity optomechanical system that is coherently driven by a bichromatic input field consisting of a control field and a probe field and that works beyond the perturbative regime. Our numerical analysis with experimentally achievable parameters confirms that robust high-order sideband generation and typical spectral structures with nonperturbative features can be created even under weak driven fields. The dependence of the high-order sideband generation on the atomic parameters are also discussed in detail, including the decay rate of the atoms and the coupling parameter between the atoms and the cavity field. We show that the cutoff order as well as the amplitude of the higher-order sidebands can be well tuned by the atomic coupling strength and the atomic decay rate. The proposed mechanism of enhancing optical nonlinearity is quite general and can be adopted to optomechanical systems with different types of cavity.

Synthesis of superior fast charging-discharging nano-LiFePO4/C from nano-FePO4 generated using a confined area impinging jet reactor approach.

Science.gov (United States)

Liu, Xiao-min; Yan, Pen; Xie, Yin-Yin; Yang, Hui; Shen, Xiao-dong; Ma, Zi-Feng

2013-06-14

LiFePO4/C nanocomposites with excellent electrochemical performance is synthesized from nano-FePO4, generated by a novel method using a confined area impinging jet reactor (CIJR). When discharged at 80 C (13.6 Ag(-1)), the LiFePO4/C delivers a discharge capacity of 95 mA h g(-1), an energy density of 227 W h kg(-1) and a power density of 34 kW kg(-1).

Evaluation of a hydride generation-atomic fluorescence system for the determination of arsenic using a dielectric barrier discharge atomizer

International Nuclear Information System (INIS)

Zhu Zhenli; Liu Jixin; Zhang Sichun; Na Xing; Zhang Xinrong

2008-01-01

A new atomizer based on atmospheric pressure dielectric barrier discharge (DBD) plasma was specially designed for atomic fluorescence spectrometry (AFS) in order to be applied to the measurement of arsenic. The characteristics of the DBD atomizer and the effects of different parameters (power, discharge gas, gas flow rate, and KBH 4 concentration) were discussed in the paper. The DBD atomizer shows the following features: (1) low operation temperature (between 44 and 70 deg. C, depending on the operation conditions); (2) low power consumption; (3) operation at atmospheric pressure. The detection limit of As(III) using hydride generation (HG) with the proposed DBD-AFS was 0.04 μg L -1 . The analytical results obtained by the present method for total arsenic in reference materials, orchard leaves (SRM 1571) and water samples GBW(E) 080390, agree well with the certified values. The present HG-DBD-AFS is more sensitive and reliable for the determination of arsenic. It is a very promising technique allowing for field arsenic analysis based on atomic spectrometry

48 CFR 225.901 - Policy.

Science.gov (United States)

2010-10-01

... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Policy. 225.901 Section... DEFENSE SOCIOECONOMIC PROGRAMS FOREIGN ACQUISITION Customs and Duties 225.901 Policy. Unless the supplies are entitled to duty-free treatment under a special category in the Harmonized Tariff Schedule of the...

25 CFR 225.26 - Auditing and accounting.

Science.gov (United States)

2010-04-01

... 25 Indians 1 2010-04-01 2010-04-01 false Auditing and accounting. 225.26 Section 225.26 Indians... SOLID MINERALS AGREEMENTS Minerals Agreements § 225.26 Auditing and accounting. The Secretary may... agreement. Procedures and standards used for accounting and auditing of minerals agreements will be in...

Performance and beam characteristics of the PANTAK THERAPAX HF225 X-ray therapy machine

Energy Technology Data Exchange (ETDEWEB)

Yiannakkaras, C; Papadopoulos, N; Christodoulides, G [Department of Medical Physics, Nicosia General Hospital, 1450 Nicosia (Cyprus)

1999-12-31

The performance and beam characteristics of the new PANTAK THERAPAX HF225 X-ray therapy machine have been measured, evaluated and discussed. Eight beam qualities within the working range of generating potentials between 50 and 225 kVp are used in our department. These beam qualities have been investigated in order to provide a data base specific to our machine. Beam Quality, Central Axis Depth Dose, Output, Relative Field Uniformity and Timer Error were investigated. (authors) 11 refs., 4 figs., 9 tabs.

Contacting nanowires and nanotubes with atomic precision for electronic transport

KAUST Repository

Qin, Shengyong; Hellstrom, Sondra; Bao, Zhenan; Boyanov, Boyan; Li, An-Ping

2012-01-01

Making contacts to nanostructures with atomic precision is an important process in the bottom-up fabrication and characterization of electronic nanodevices. Existing contacting techniques use top-down lithography and chemical etching, but lack atomic precision and introduce the possibility of contamination. Here, we report that a field-induced emission process can be used to make local contacts onto individual nanowires and nanotubes with atomic spatial precision. The gold nano-islands are deposited onto nanostructures precisely by using a scanning tunneling microscope tip, which provides a clean and controllable method to ensure both electrically conductive and mechanically reliable contacts. To demonstrate the wide applicability of the technique, nano-contacts are fabricated on silicide atomic wires, carbon nanotubes, and copper nanowires. The electrical transport measurements are performed in situ by utilizing the nanocontacts to bridge the nanostructures to the transport probes. © 2012 American Institute of Physics.

Degradation of lindane by a novel embedded bio-nano hybrid system in aqueous environment.

Science.gov (United States)

Salam, Jaseetha Abdul; Das, Nilanjana

2015-03-01

The objective of this study was to evaluate the effect of an embedded bio-nano hybrid system using nanoscale zinc oxide (n-ZnO) and lindane-degrading yeast Candida VITJzN04 for lindane degradation. Nano-embedding of the yeast was done with chemically synthesized n-ZnO particles (50 mg/mL) and was visualized by atomic force microscope (AFM) and scanning electron microscope (SEM). Nanoparticles were embedded substantially on the surfaces of the yeast cells and translocated into the cell cytoplasm without causing any lethal effect to the cell until 50 mg/mL. Lindane (600 mg/L) degradation was studied both in the individual and hybrid system. Rapid reductive-dechlorination of lindane was attained with n-ZnO under illuminated conditions, with the generation of chlorobenzene and benzene as dechlorination products. The bio-nano hybrid was found to be more effective compared to the native yeasts for lindane degradation and resulted in complete removal within 3 days. The kinetic data analysis implied that the half-life of lindane was 9 h for bio-nano hybrid and 28 h for Candida VITJzN04. The enhanced lindane degradation by bio-nano hybrid might be due to increased porosity and permeability of the yeast cell membrane, facilitating the easy entry of lindane into cell cytoplasm and n-ZnO-mediated dechlorination. To the best of our knowledge, this report, for the first time, suggests the use of n-ZnO-mediated dechlorination of lindane and the novel bio-nano hybrid system that reduces the half-life to one third of the time taken by the yeast alone. The embedded bio-nano hybrid system may be exploited as an effective remediation tool for the treatment of lindane-contaminated wastewaters.

Coloration of metallic and/or ceramic surfaces obtained by atomic layer deposited nano-coatings

Energy Technology Data Exchange (ETDEWEB)

Guzman, L., E-mail: luisg47@gmail.com [Fondazione Bruno Kessler (FBK), Centro Materiali e Microsistemi, Functional Materials & Photonic Structures Unit, via Sommarive 18, 38123 Trento (Italy); Vettoruzzo, F. [Ronda High Tech, via Vegri 83, 36010 Zane’, Vicenza (Italy); Laidani, N. [Fondazione Bruno Kessler (FBK), Centro Materiali e Microsistemi, Functional Materials & Photonic Structures Unit, via Sommarive 18, 38123 Trento (Italy)

2016-02-29

By depositing single layer coatings by means of physical vapor techniques, tailoring of their coloration is generally complex because a given color can be obtained only by very high composition control. Physical vapor deposition (PVD) processes are expensive and cannot be easily used for obtaining conformal coating on three-dimensional objects. Moreover PVD coatings exhibit intrinsic defects (columnar structures, pores) that affect their functional properties and applications such as barrier layers. Atomic layer deposition (ALD) technology delivers conformal coatings on different materials with very low defectiveness. A straightforward coloration can be obtained by a combination of two types of layers with different refraction index, deposited to high thickness precision. Computer simulation studies were performed to design the thickness and architecture of multilayer structures, to a total thickness of approximately 100 nm, suitable to modify the typical coloration of some materials, without altering their other physical and chemical properties. The most promising nano-layered structures were then deposited by ALD and tested with regard to their optical properties. Their total thicknesses were specified in such a way to be technically feasible and compatible with future industrial production. The materials employed in this study to build the optical coatings, are two oxides (Al{sub 2}O{sub 3}, TiO{sub 2}) deposited at 120 °C and two nitrides (AlN, TiN), which need a deposition temperature of 400 °C. The possibility of using such modern deposition technology for esthetic and decorative purposes, while maintaining the functional properties, opens perspectives of industrial applications. - Highlights: • Computer simulation is done to design multilayers made of Al{sub 2}O{sub 3}, TiO{sub 2}, AlN, and TiN. • Total thickness (< 120 nm) is specified to be compatible with industrial production. • The most promising nano-layered structures are then produced and

Coloration of metallic and/or ceramic surfaces obtained by atomic layer deposited nano-coatings

International Nuclear Information System (INIS)

Guzman, L.; Vettoruzzo, F.; Laidani, N.

2016-01-01

By depositing single layer coatings by means of physical vapor techniques, tailoring of their coloration is generally complex because a given color can be obtained only by very high composition control. Physical vapor deposition (PVD) processes are expensive and cannot be easily used for obtaining conformal coating on three-dimensional objects. Moreover PVD coatings exhibit intrinsic defects (columnar structures, pores) that affect their functional properties and applications such as barrier layers. Atomic layer deposition (ALD) technology delivers conformal coatings on different materials with very low defectiveness. A straightforward coloration can be obtained by a combination of two types of layers with different refraction index, deposited to high thickness precision. Computer simulation studies were performed to design the thickness and architecture of multilayer structures, to a total thickness of approximately 100 nm, suitable to modify the typical coloration of some materials, without altering their other physical and chemical properties. The most promising nano-layered structures were then deposited by ALD and tested with regard to their optical properties. Their total thicknesses were specified in such a way to be technically feasible and compatible with future industrial production. The materials employed in this study to build the optical coatings, are two oxides (Al_2O_3, TiO_2) deposited at 120 °C and two nitrides (AlN, TiN), which need a deposition temperature of 400 °C. The possibility of using such modern deposition technology for esthetic and decorative purposes, while maintaining the functional properties, opens perspectives of industrial applications. - Highlights: • Computer simulation is done to design multilayers made of Al_2O_3, TiO_2, AlN, and TiN. • Total thickness (< 120 nm) is specified to be compatible with industrial production. • The most promising nano-layered structures are then produced and optically tested. • An

On the impact of second generation mating and offspring in multi-generation reproductive toxicity studies on classification and labelling of substances in Europe

DEFF Research Database (Denmark)

Rorije, Emiel; Muller, André; Beekhuijzen, Manon E.W.

2011-01-01

The possible impact on classification and labelling decisions of effects observed in second generation parental (P1) and offspring (F2) parameters in multi-generation studies was investigated. This was done for 50 substances classified as reproductive toxicants in Europe, for which a multi-genera...... and reduced animal use, provide strong further support for replacement of the classical two-generation reproductive toxicity study by the EOGRTS in regulatory reproductive toxicity assessment....

Atomic Layer Deposition to Enable the Production, Optimization and Protection of Spaceflight Hardware

Data.gov (United States)

National Aeronautics and Space Administration — Atomic Layer Deposition (ALD) a cost effective nano-manufacturing technique allows for the conformal coating of substrates with atomic control in a benign...

Rotary-atomizer electric power generator

NARCIS (Netherlands)

Nguyen, Trieu; Tran, Tuan; de Boer, Hans L.; van den Berg, Albert; Eijkel, Jan C.T.

2015-01-01

We report experimental and theoretical results on a ballistic energy-conversion method based on a rotary atomizer working with a droplet acceleration-deceleration cycle. In a rotary atomizer, liquid is fed onto the center of a rotating flat surface, where it spreads out under the action of the

48 CFR 225.7605 - Solicitation provision.

Science.gov (United States)

2010-10-01

... SYSTEM, DEPARTMENT OF DEFENSE SOCIOECONOMIC PROGRAMS FOREIGN ACQUISITION Secondary Arab Boycott of Israel... accordance with 225.7604, use the provision at 252.225-7031, Secondary Arab Boycott of Israel, in all...

Calculations of Non-equilibrium Effects in Nano-conductors

DEFF Research Database (Denmark)

Christensen, Rasmus Bjerregaard

This thesis is concerned with the interplay between electrical current and vibrational and plasmonic excitations. The development of nano-scale devices for electronics relies on the ability to identify individual atoms and molecules as well as their geometry and electronic structure. In this thes...

Assessment methods of injection moulded nano-patterned surfaces

DEFF Research Database (Denmark)

Menotti, S.; Bisacco, G.; Hansen, H. N.

2014-01-01

algorithm for feature recognition. To compare the methods, the mould insert and a number of replicated nano-patterned surfaces, injection moulded with an induction heating aid, were measured on nominally identical locations by means of an atomic force microscope mounted on a manual CMM....

Intense deuterium nuclear fusion of pycnodeuterium-lumps coagulated locally within highly deuterated atom clusters

CERN Document Server

Yoshiaki, A; Zhang, Y C

2002-01-01

Embedded nano-Pd particles of 5 nm in size instantly abundant D-atoms more than 250% in the atomic ratio against Pd-atoms at room temperature when they are kept in D sub 2 gas pressurized to less than 10 atm. In such ultrahigh densities, 2-4 D-atoms can be coagulated inside each octahedral space of Pd lattice (pycnodeuterium-lump). When a stimulation energy such as latticequake causing by ultrasonic wave was supplied to those highly deuterated Pd particles, intense deuterium nuclear fusion (''solid fusion'') was generated there and both excess heat and sup 4 He gas were abundantly produced. Naturally, these facts can not be realized at all in bulk Pd. The results show that the nuclear fusion occurs without any hazardous rays in pycnodeuterium-lumps coagulated locally inside the each cell of the host metal lattice. These unit cells correspond to minimum unit of the solid fusion reactor as a ''Lattice Reactor''. (author)

Determination of trace elements in atomic absorption spectrophotometry. Study of the atomic cloud and atom generator. Application to the measurement of physical quantities

International Nuclear Information System (INIS)

Hircq, Bernard.

1976-06-01

After the description of the absorption cell the principal parameters are studied: argon flow rate in the cell, atomization temperature, cell geometry etc. The technique is applied to the measurement of impurities in uranium after deposition on a carbon filament. The atomic concentration distribution and the dimensions of the cloud generated by a graphite filament are then studied along the axes parallel to the filament and as a function of the various experimental parameters. From the determination of the cloud elevation rate it is possible to calculate the absolute atomic concentration, which allows certain physical quantities to be evaluated: oscillator force, Lorentz Widening, diffusion coefficient... The size and penetration depth of the deposit are then determined with an ionic microprobe and the distribution with a Castaing microprobe. The chemical transformations undergone by the uranium matrix during the heat cycles are studied by the X-ray method [fr

Radioactive labelling of peptidic hormones

International Nuclear Information System (INIS)

Fromageot, P.; Pradelles, P.; Morgat, J.L.; Levine, H.

1976-01-01

The labelling of peptidic hormones requires stability, specificity and sensitivity of the label. Introduction of a radioactive atome is one way to satisfy these criteria. Several processes have been described to prepare radioactive TRF: synthesis of the peptide with labelled aminoacids or introduction of the label into the hormone. In that approach, tritium can be substituted in the imidazole ring, via precursors activating the proper carbon. Monoiodo TRF leads essentially to tritium labelling of the 5 positions whereas monoazo TRF allows the preparation of 3 H TRF labelled in the 2 positions. Di-substituted TRF leads to labelling into the 2 and 5 carbons. Labelled analogs of TRF can be prepared with labelled iodine; further developments of peptide labelling, will be presented. In particular, the homolytic scission of the C-iodine, bond by photochemical activation. The nascent carbon radical can be stabilized by a tritiated scavenger. This approach eliminates the use of heavy metal catalysts

Nano-manipulation of single DNA molecules

International Nuclear Information System (INIS)

Hu Jun; Shanghai Jiaotong Univ., Shanghai; Lv Junhong; Wang Guohua; Wang Ying; Li Minqian; Zhang Yi; Li Bin; Li Haikuo; An Hongjie

2004-01-01

Nano-manipulation of single atoms and molecules is a critical technique in nanoscience and nanotechnology. This review paper will focus on the recent development of the manipulation of single DNA molecules based on atomic force microscopy (AFM). Precise manipulation has been realized including varied manipulating modes such as 'cutting', 'pushing', 'folding', 'kneading', 'picking up', 'dipping', etc. The cutting accuracy is dominated by the size of the AFM tip, which is usually 10 nm or less. Single DNA fragments can be cut and picked up and then amplified by single molecule PCR. Thus positioning isolation and sequencing can be performed. (authors)

UHV-STM manipulation of single flat gold nano-islands for constructing interconnection nanopads on MoS2

International Nuclear Information System (INIS)

Yang, JianShu; Jie, Deng; Chandrasekhar, N; Joachim, C

2007-01-01

We demonstrate manipulation of metallic islands containing nearly a million atoms with a precision of one lattice spacing on a MoS 2 surface, one at a time. Optimizing the growth conditions yields triangular shape metallic nano-islands 40 nm in lateral size and 12 nm in height on the MoS2 surface. The manipulation of these nano-islands is done one at a time using the scanning tunneling microscope, and a fully planar 4 pad nanostructure is demonstrated, where one apex of each triangular nano-island is pointing towards a central working MoS 2 area of 12 nm x 24 nm in which atomic cleanliness is preserved. The feedback loop conditions to achieve this manipulation are discussed. This fully planar 4 pads nano-structure is ready to be interconnected by a multi-tip system

Characterization polyethylene terephthalate nanocomposites mixing with nano-silica and titanium oxide

Directory of Open Access Journals (Sweden)

Rusu Mircea A.

2017-01-01

Full Text Available Polyethylene terephthalate (PET based nanocomposites containing nano-silica (Aerosil (Degusa and titanium oxide (TiO2 (Merk were prepared by melt compounding. Influence of nano-silica and titanium oxide on properties of the resulting nanocomposites was investigated by scanning electron microscopy (SEM, Fourier transform infrared spectroscopy (FTIR and atomic force microscopy (AFM. The possible interaction between nano-silica and titanium oxide particles with PET functional groups at bulk and surface was elucidated by transmission of FTIR-ATR spectroscopy. AFM studies of the resulting nanocomposites showed an increased surface roughness compared to pure PET. SEM images illustrated that nano-silica particles have tendency to migrate to the surface of the PET matrix much more than titanium oxide powder.

Greenberger-Horne-Zeilinger state generation of three atoms trapped in two remote cavities

International Nuclear Information System (INIS)

Li Yanling; Fang Maofa; Xiao Xing; Zeng Ke; Wu Chao

2010-01-01

We consider a system composed of a single-atom-trapped cavity (A) and a remote two-atom-trapped cavity (B) which are connected by an optical fibre. It is shown that a shared Greenberger-Horne-Zeilinger (GHZ) state of the three atoms can be deterministically generated by controlling the time of interaction or via the adiabatic passage based on this system. The influence of various decoherence processes such as spontaneous emission and photon loss on the fidelity is also investigated. It is found that our schemes can be realized with high fidelity even when these decoherence processes are considered.

Greenberger-Horne-Zeilinger state generation of three atoms trapped in two remote cavities

Energy Technology Data Exchange (ETDEWEB)

Li Yanling; Fang Maofa; Xiao Xing; Zeng Ke; Wu Chao, E-mail: mffang@hunnu.edu.c [Key Laboratory of Low-Dimensional Quantum Structures and Quantum Control, Ministry of Education, and College of Physics and Information Science, Hunan Normal University, Changsha 410081 (China)

2010-04-28

We consider a system composed of a single-atom-trapped cavity (A) and a remote two-atom-trapped cavity (B) which are connected by an optical fibre. It is shown that a shared Greenberger-Horne-Zeilinger (GHZ) state of the three atoms can be deterministically generated by controlling the time of interaction or via the adiabatic passage based on this system. The influence of various decoherence processes such as spontaneous emission and photon loss on the fidelity is also investigated. It is found that our schemes can be realized with high fidelity even when these decoherence processes are considered.

Multiple electromechanically-induced-transparency windows and Fano resonances in hybrid nano-electro-optomechanics

Science.gov (United States)

Ullah, Kamran; Jing, Hui; Saif, Farhan

2018-03-01

We show multiple electromechanically-induced transparency (EMIT) windows in a hybrid nano-electro-optomechanical system in the presence of two-level atoms coupled to a single-mode cavity field. The multiple EMIT-window profile can be observed by controlling the atom field coupling as well as Coulomb coupling between the two charged mechanical resonators. We derive the analytical expression of the multiple-EMIT-windows profile and describe the splitting of multiple EMIT windows as a function of optomechanical coupling, atom-field coupling, and Coulomb coupling. In particular, we discuss the robustness of the system against the cavity decay rate. We compare the results of identical mechanical resonators to different mechanical resonators. We further show how the hybrid nano-electro-optomechanics coupled system can lead to the splitting of the multiple Fano resonances (MFR). The Fano resonances are very sensitive to decay terms in such systems, i.e., atoms, cavities, and the mechanical resonators.

A facile strategy for fabrication of nano-ZnO/yeast composites and their adsorption mechanism towards lead (II) ions

Energy Technology Data Exchange (ETDEWEB)

Zhang, Wei; Meng, Lingyin [College of Science, Sichuan Agricultural University, Yaan 625014 (China); Mu, Guiqin [Maize Research Institute of Sichuan Agricultural University, Wenjiang 611130 (China); Zhao, Maojun; Zou, Ping [College of Science, Sichuan Agricultural University, Yaan 625014 (China); Zhang, Yunsong, E-mail: yaanyunsong@126.com [College of Science, Sichuan Agricultural University, Yaan 625014 (China)

2016-08-15

Highlights: • Nano-ZnO/yeast composites were fabricated by alkali hydrothermal method. • Nano-ZnO was in-situ achieved and anchored on the yeast surface. • Alkali and hydrothermal process cause more exposed funcitional groups on yeast. • Nano-ZnO/yeast composites show higher Pb{sup 2+} adsorption ability than pristine yeast. • Nano-ZnO and exposed functional groups synergistically participate in adsorption. - Abstract: Nano-ZnO/yeast composites were successfully fabricated by one-step alkali hydrothermal method, and their adsorption properties for Pb{sup 2+} ions were also evaluated. Various influencing parameters of nano-ZnO/yeast composites, such as initial pH, contact time and initial Pb{sup 2+} concentration were investigated, respectively. The maximum adsorption capacity of nano-ZnO/yeast composites for Pb{sup 2+} (31.72 mg g{sup −1}) is 2.03 times higher than that of pristine yeast (15.63 mg g{sup −1}). The adsorption mechanism of nano-ZnO/yeast composites was studied by a series of techniques. Scanning electron microscopy (SEM) showed that nano-ZnO is evenly deposited on yeast surface. Atomic force microscopy (AFM) analysis exhibited that the yeast surface is rougher than that of pristine yeast. Energy dispersive X-ray detector (EDX) and X-ray diffraction (XRD) indicated the existence of nano-ZnO on yeast surface. Additionally, X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR) measurements further illustrated that alkali hydrothermal method causes not only the generation and anchorage of nano-ZnO on yeast surface but also the exposure of more functional groups (such as amino, carboxyl groups etc.) on yeast surface, both of which could adsorb Pb{sup 2+} via synergistic effect.

A facile strategy for fabrication of nano-ZnO/yeast composites and their adsorption mechanism towards lead (II) ions

International Nuclear Information System (INIS)

Zhang, Wei; Meng, Lingyin; Mu, Guiqin; Zhao, Maojun; Zou, Ping; Zhang, Yunsong

2016-01-01

Highlights: • Nano-ZnO/yeast composites were fabricated by alkali hydrothermal method. • Nano-ZnO was in-situ achieved and anchored on the yeast surface. • Alkali and hydrothermal process cause more exposed funcitional groups on yeast. • Nano-ZnO/yeast composites show higher Pb"2"+ adsorption ability than pristine yeast. • Nano-ZnO and exposed functional groups synergistically participate in adsorption. - Abstract: Nano-ZnO/yeast composites were successfully fabricated by one-step alkali hydrothermal method, and their adsorption properties for Pb"2"+ ions were also evaluated. Various influencing parameters of nano-ZnO/yeast composites, such as initial pH, contact time and initial Pb"2"+ concentration were investigated, respectively. The maximum adsorption capacity of nano-ZnO/yeast composites for Pb"2"+ (31.72 mg g"−"1) is 2.03 times higher than that of pristine yeast (15.63 mg g"−"1). The adsorption mechanism of nano-ZnO/yeast composites was studied by a series of techniques. Scanning electron microscopy (SEM) showed that nano-ZnO is evenly deposited on yeast surface. Atomic force microscopy (AFM) analysis exhibited that the yeast surface is rougher than that of pristine yeast. Energy dispersive X-ray detector (EDX) and X-ray diffraction (XRD) indicated the existence of nano-ZnO on yeast surface. Additionally, X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR) measurements further illustrated that alkali hydrothermal method causes not only the generation and anchorage of nano-ZnO on yeast surface but also the exposure of more functional groups (such as amino, carboxyl groups etc.) on yeast surface, both of which could adsorb Pb"2"+ via synergistic effect.

COMPREHENSIVE ANALYSIS OF BIOLOGICALLY RELEVANT ARSENICALS BY PH-SELECTIVE HYDRIDE GENERATION-ATOMIC ABSORPTION SPECTROMETRY

Science.gov (United States)

A method based on pH-selective generation and separation of arsines is commonly used for analysis of inorganic, methylated, and dimethylated trivalent and pentavalent arsenicals by hydride generation-atomic absorption spectrometry (HG-AAS). We have optimized this method to pe...

Combustion synthesis of CaSc{sub 2}O{sub 4}:Ce{sup 3+} nano-phosphors in a closed system

Energy Technology Data Exchange (ETDEWEB)

Peng Wenfang; Zou Shaoyu; Liu Guanxi; Xiao Quanlan; Zhang Rui; Xie Lijuan; Cao Liwei [Department of Chemistry, Jinan University, Guangzhou 510632 (China); Meng Jianxin, E-mail: tmjx@jnu.edu.cn [Institute of Nano-Chemistry, Jinan University, Guangzhou 510632 (China); Liu Yingliang [Institute of Nano-Chemistry, Jinan University, Guangzhou 510632 (China)

2011-06-09

Highlights: > CaSc{sub 2}O{sub 4}:Ce{sup 3+} nano-phosphors can be prepared by a single-step combustion method. > The ignition temperature is the lowest in the combustion synthesis of Ce{sup 3+}/Eu{sup 2+} doped phosphors. > The as-prepared nano-phosphors give a uniform particle size in the range of 15-20 nm and have highly dispersity and fluorescence intensity. > It is a convenient method for preparation of monodispersed oxide nano-phosphors, especially those being sensitive to air at high temperature. - Abstract: The CaSc{sub 2}O{sub 4}:Ce{sup 3+} nano-phosphors were successfully prepared by a single-step combustion method at an ignition temperature as low as 200 deg. C in a closed autoclave using glycine as a fuel and PEG4000 as a dispersant. The samples were characterized by X-ray diffraction (XRD), photoluminescence (PL) spectroscopy, scanning electron microscopy (SEM) and transmission electron microscope (TEM). The results revealed that CaSc{sub 2}O{sub 4}:Ce{sup 3+} nano-phosphors can be conveniently prepared at an ignition temperature as low as 200 deg. C, which was much lower than that in the ordinary combustion methods. The optimized ignition temperature was 220 deg. C. The CaSc{sub 2}O{sub 4}:Ce{sup 3+} nano-phosphors give a uniform particle size in the range of 15-20 nm. The low ignition temperature and the addition of PEG4000 dispersant play important roles in the formation of small sized nanoparticles. The as-prepared nano-phosphors were incompact aggregates, but highly dispersed nano-phosphors can be obtained after further ultrasonic treatment. The CaSc{sub 2}O{sub 4}:Ce{sup 3+} nano-phosphors give satisfactory luminescence characteristic benefiting from the closed circumstance, in which cerium atoms can be isolated from the oxidizing atmosphere and non-fluorescent Ce{sup 4+} ions can be ruled out. The present highly dispersed CaSc{sub 2}O{sub 4}:Ce{sup 3+} nano-phosphors with efficient fluorescence are promising in the field of biological labeling

Generation of atto-second pulses in atoms and molecules

International Nuclear Information System (INIS)

Haessler, St.

2009-12-01

When a low-frequency laser pulse is focused to a high intensity into a gas, the electric field of the laser light may become of comparable strength to that felt by the electrons bound in an atom or molecule. A valence electron can then be 'freed' by tunnel ionization, accelerated by the strong oscillating laser field and can eventually re-collide and recombine with the ion. The gained kinetic energy is then released as a burst of coherent X-UV light and the macroscopic gas medium then becomes a source of X-UV light pulses of atto-second (1 as equals 10 -18 s) duration. This is the natural time-scale of electron dynamics in atoms and molecules. The largest part of this thesis deals with experiments where molecules are the harmonic generation medium and the re-colliding electron wave packet acts as a 'self-probe'. In several experiments, we demonstrate the potential of this scheme to observe or image ultra-fast intra-molecular electronic and nuclear dynamics. In particular, we have performed the first phase measurements of the high harmonic emission from aligned molecules and we have extracted the recombination dipole matrix element. This observable contains signatures of quantum interference between the continuum and bound parts of the total electronic wavefunction. It is shown how this quantum interference can be utilized to shape the atto-second light emission from the molecules. In a second part of this thesis, we use the well characterized coherent X-UV light emitted by rare gas atoms to photo-ionize molecules. Measuring the ejected photoelectron wave packet then allows to extract information on the photoionization process itself, and possibly about the initial bound and final continuum states of the electron. The last chapter of this manuscript describes studies of high harmonic and atto-second light pulse generation in a different medium: ablation plasmas. (author)

14 CFR 13.225 - Offer of proof.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Offer of proof. 13.225 Section 13.225... INVESTIGATIVE AND ENFORCEMENT PROCEDURES Rules of Practice in FAA Civil Penalty Actions § 13.225 Offer of proof. A party whose evidence has been excluded by a ruling of the administrative law judge may offer the...

Biological Atomic Force Microscopy for Imaging Gold-Labeled Liposomes on Human Coronary Artery Endothelial Cells

Directory of Open Access Journals (Sweden)

Ana-María Zaske

2013-01-01

Full Text Available Although atomic force microscopy (AFM has been used extensively to characterize cell membrane structure and cellular processes such as endocytosis and exocytosis, the corrugated surface of the cell membrane hinders the visualization of extracellular entities, such as liposomes, that may interact with the cell. To overcome this barrier, we used 90 nm nanogold particles to label FITC liposomes and monitor their endocytosis on human coronary artery endothelial cells (HCAECs in vitro. We were able to study the internalization process of gold-coupled liposomes on endothelial cells, by using AFM. We found that the gold-liposomes attached to the HCAEC cell membrane during the first 15–30 min of incubation, liposome cell internalization occurred from 30 to 60 min, and most of the gold-labeled liposomes had invaginated after 2 hr of incubation. Liposomal uptake took place most commonly at the periphery of the nuclear zone. Dynasore monohydrate, an inhibitor of endocytosis, obstructed the internalization of the gold-liposomes. This study showed the versatility of the AFM technique, combined with fluorescent microscopy, for investigating liposome uptake by endothelial cells. The 90 nm colloidal gold nanoparticles proved to be a noninvasive contrast agent that efficiently improves AFM imaging during the investigation of biological nanoprocesses.

Isotopically labelled vitamin D derivatives and processes for preparing same

International Nuclear Information System (INIS)

Deluca, H.R.; Schnoes, H.K.; Napoli, J.L.; Fivizzani, M.A.

1981-01-01

This invention relates to 26,27-isotopically labelled vitamin D 3 compounds, including radiolabelled vitamin D 3 compounds of high specific activity, methods for their preparation, and intermediates obtained in their synthesis. The method involves reacting an ester of a 26,27-dinor-vitamin D-25-carboxylic acid with an isotopically labelled methyl Grignard reagent or methyl lithium reagent to obtain a 26,27-isotopically labelled compound in which at least some of the H atoms and/or C atoms are heavy isotopes. (author)

Atoms, molecules & elements

CERN Document Server

Graybill, George

2007-01-01

Young scientists will be thrilled to explore the invisible world of atoms, molecules and elements. Our resource provides ready-to-use information and activities for remedial students using simplified language and vocabulary. Students will label each part of the atom, learn what compounds are, and explore the patterns in the periodic table of elements to find calcium (Ca), chlorine (Cl), and helium (He) through hands-on activities.

Single-label kinase and phosphatase assays for tyrosine phosphorylation using nanosecond time-resolved fluorescence detection.

Science.gov (United States)

Sahoo, Harekrushna; Hennig, Andreas; Florea, Mara; Roth, Doris; Enderle, Thilo; Nau, Werner M

2007-12-26

The collision-induced fluorescence quenching of a 2,3-diazabicyclo[2.2.2]oct-2-ene-labeled asparagine (Dbo) by hydrogen atom abstraction from the tyrosine residue in peptide substrates was introduced as a single-labeling strategy to assay the activity of tyrosine kinases and phosphatases. The assays were tested for 12 different combinations of Dbo-labeled substrates and with the enzymes p60c-Src Src kinase, EGFR kinase, YOP protein tyrosine phosphatase, as well as acid and alkaline phosphatases, thereby demonstrating a broad application potential. The steady-state fluorescence changed by a factor of up to 7 in the course of the enzymatic reaction, which allowed for a sufficient sensitivity of continuous monitoring in steady-state experiments. The fluorescence lifetimes (and intensities) were found to be rather constant for the phosphotyrosine peptides (ca. 300 ns in aerated water), while those of the unphosphorylated peptides were as short as 40 ns (at pH 7) and 7 ns (at pH 13) as a result of intramolecular quenching. Owing to the exceptionally long fluorescence lifetime of Dbo, the assays were alternatively performed by using nanosecond time-resolved fluorescence (Nano-TRF) detection, which leads to an improved discrimination of background fluorescence and an increased sensitivity. The potential for inhibitor screening was demonstrated through the inhibition of acid and alkaline phosphatases by molybdate.

Single-atom lasing induced atomic self-trapping

International Nuclear Information System (INIS)

Salzburger, T.; Ritsch, H.

2004-01-01

We study atomic center of mass motion and field dynamics of a single-atom laser consisting of a single incoherently pumped free atom moving in an optical high-Q resonator. For sufficient pumping, the system starts lasing whenever the atom is close to a field antinode. If the field mode eigenfrequency is larger than the atomic transition frequency, the generated laser light attracts the atom to the field antinode and cools its motion. Using quantum Monte Carlo wave function simulations, we investigate this coupled atom-field dynamics including photon recoil and cavity decay. In the regime of strong coupling, the generated field shows strong nonclassical features like photon antibunching, and the atom is spatially confined and cooled to sub-Doppler temperatures. (author)

Increasing The Electric Field For An Improved Search For Time-Reversal Violation Using Radium-225

Science.gov (United States)

Powers, Adam

2017-09-01

Radium-225 atoms, because of their unusual pear-shaped nuclei, have an enhanced sensitivity to the violation of time reversal symmetry. A breakdown of this fundamental symmetry could help explain the apparent scarcity of antimatter in the Universe. Our goal is to improve the statistical sensitivity of an ongoing experiment that precisely measures the EDM of Radium-225. This can be done by increasing the electric field acting on the Radium atoms. We do this by increasing the voltage that can be reliably applied between two electrodes, and narrowing the gap between them. We use a varying high voltage system to condition the electrodes using incremental voltage ramp tests to achieve higher voltage potential differences. Using an adjustable gap mount to change the distance between the electrodes, specific metals for their composition, and a clean room procedure to keep particulates out of the system, we produce a higher and more stable electric field. Progress is marked by measurements of the leakage current between the electrodes during our incremental voltage ramp tests or emulated tests of the actual experiment, with low and constant current showing stability of the field. This project is supported by Michigan State University, and the US DOE, Office of Science, Office of Nuclear Physics, under Contract DE-AC02-06CH11357.

Prediction Surface Morphology of Nanostructure Fabricated by Nano-Oxidation Technology.

Science.gov (United States)

Huang, Jen-Ching; Chang, Ho; Kuo, Chin-Guo; Li, Jeen-Fong; You, Yong-Chin

2015-12-04

Atomic force microscopy (AFM) was used for visualization of a nano-oxidation technique performed on diamond-like carbon (DLC) thin film. Experiments of the nano-oxidation technique of the DLC thin film include those on nano-oxidation points and nano-oxidation lines. The feature sizes of the DLC thin film, including surface morphology, depth, and width, were explored after application of a nano-oxidation technique to the DLC thin film under different process parameters. A databank for process parameters and feature sizes of thin films was then established, and multiple regression analysis (MRA) and a back-propagation neural network (BPN) were used to carry out the algorithm. The algorithmic results are compared with the feature sizes acquired from experiments, thus obtaining a prediction model of the nano-oxidation technique of the DLC thin film. The comparative results show that the prediction accuracy of BPN is superior to that of MRA. When the BPN algorithm is used to predict nano-point machining, the mean absolute percentage errors (MAPE) of depth, left side, and right side are 8.02%, 9.68%, and 7.34%, respectively. When nano-line machining is being predicted, the MAPEs of depth, left side, and right side are 4.96%, 8.09%, and 6.77%, respectively. The obtained data can also be used to predict cross-sectional morphology in the DLC thin film treated with a nano-oxidation process.

Synthesis of 14C-labeled and stable isotope-labeled CGS 16617

International Nuclear Information System (INIS)

Chaudhuri, N.K.; Markus, B.; Sung Mingsang

1988-01-01

The synthesis of a 14 C-labeled and two stable isotope-labeled analogs of CGS 16617 is described. The synthetic method involved the preparation of tetrahydro-3-bromo-1-benzazepin-2-one, labeled with a 14 C or four deuterium atoms, followed by introduction of two side chains at 1- and 3-positions. The labeled bromobenzazepinones were prepared by Beckmann rearrangement of bromo-oximes of α-tetralones, obtained by cyclization of labeled benzenebutanoic acids. The 14 C-labeled acid was prepared by hydrolysis of the nitrile, prepared by reaction of 3-bromopropylbenzene and K 14 CN. The tetradeutero acid was prepared from ethyl phenylpropynoate by catalytic reduction of the triple bond with deuterium gas, followed by reduction of the deuterated ester with lithium aluminium hydride and conversion of the resulting alcohol into the carboxylic acid. The acetic acid side chain was introduced by N-alkylation with ethyl bromoacetate or ethyl bromoacetate-1, 2- 13 C 2 followed by hydrolysis, and the L-lysine side chain, by reaction with L-(-)-3-amino-ε-caprolactam followed by hydrolysis of the caprolactam ring. (author)

Preparation of nano-biomaterials with Leptolyngbia foveolarum and heavy metal biosorption by free and immobilized algal cells

International Nuclear Information System (INIS)

Toncheva-Panova, T.; Pouneva, I.; Sholeva, M.; Chernev, G.

2010-01-01

Using the sol-gel procedure nano-biomaterials with incorporation of Leptolyngbia foveolarum in the silica matrix were manufactured. The immobilization of algal cells was confirmed with Scanning Electron Microscopy (SEM) investigations and photos. Observation of nano-biomaterials with Atomic Force Microscopy (AFM) shows nanostructure with well-defined nanounits and their aggregates. The potential of the Antarctic isolate L. foveolarum for sorption of Cu 2+ and Cd 2+ was studied by incubation of free algal cells and those immobilized in nano-biomaterials in the salts solutions of the two heavy metals. The rest of the heavy metal was determined with inductively coupled plasma atomic emission spectrometer (ICP-AES). It was established that the heavy metal biosorption capacity demonstrated by the free Leptolyngbia cells was retained after their incorporation in the nano-matrices. Free cells as well as embedded in silica nano-matrix sequestered the two heavy metals with greater affinity for copper. The highest binding capacity, 76% of the initial Cu 2+ concentration possessed nano-biomaterials with incorporated vegetative L. foveolarum cells, compared to 68% of free cells. For cadmium the degree of biosorption was lower - 35% by free cells and 30.2% by those incorporated in the biocer. (authors)

Sequential optimization of methotrexate encapsulation in micellar nano-networks of polyethyleneimine ionomer containing redox-sensitive cross-links

Directory of Open Access Journals (Sweden)

Abolmaali SS

2014-06-01

Full Text Available Samira Sadat Abolmaali,1 Ali Tamaddon,1,2 Gholamhossein Yousefi,1,2 Katayoun Javidnia,3 Rasoul Dinarvand41Department of Pharmaceutics, Shiraz School of Pharmacy, 2Center for Nanotechnology in Drug Delivery, 3Medicinal and Natural Products Chemistry Research Center, Shiraz University of Medical Sciences, Shiraz, Iran; 4Nanotechnology Research Centre, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, IranAbstract: A functional polycation nanonetwork was developed for delivery of water soluble chemotherapeutic agents. The complexes of polyethyleneimine grafted methoxy polyethylene glycol (PEI-g-mPEG and Zn2+ were utilized as the micellar template for cross-linking with dithiodipropionic acid, followed by an acidic pH dialysis to remove the metal ion from the micellar template. The synthesis method was optimized according to pH, the molar ratio of Zn2+, and the cross-link ratio. The atomic force microscopy showed soft, discrete, and uniform nano-networks. They were sensitive to the simulated reductive environment as determined by Ellman's assay. They showed few positive ζ potential and an average hydrodynamic diameter of 162±10 nm, which decreased to 49±11 nm upon dehydration. The ionic character of the nano-networks allowed the achievement of a higher-loading capacity of methotrexate (MTX, approximately 57% weight per weight, depending on the cross-link and the drug feed ratios. The nano-networks actively loaded with MTX presented some suitable properties, such as the hydrodynamic size of 117±16 nm, polydispersity index of 0.22, and a prolonged swelling-controlled release profile over 24 hours that boosted following reductive activation of the nanonetwork biodegradation. Unlike the PEI ionomer, the nano-networks provided an acceptable cytotoxicity profile. The drug-loaded nano-networks exhibited more specific cytotoxicity against human hepatocellular carcinoma cells if compared to free MTX at concentrations above 1 µM. The

Synthesis of Boron Nano wires, Nano tubes, and Nano sheets

International Nuclear Information System (INIS)

Patel, R.B.; Chou, T.; Iqbal, Z.

2014-01-01

The synthesis of boron nano wires, nano tubes, and nano sheets using a thermal vapor deposition process is reported. This work confirms previous research and provides a new method capable of synthesizing boron nano materials. The materials were made by using various combinations of MgB 2 , Mg(BH 4 ) 2 , MCM-41, NiB, and Fe wire. Unlike previously reported methods, a nanoparticle catalyst and a silicate substrate are not required for synthesis. Two types of boron nano wires, boron nano tubes, and boron nano sheets were made. Their morphology and chemical composition were determined through the use of scanning electron microscopy, transmission electron microscopy, and electron energy loss spectroscopy. These boron-based materials have potential for electronic and hydrogen storage applications.

Atomic Layer Deposition to Enable the Production, Optimization and Protection of Spaceflight Hardware Project

Data.gov (United States)

National Aeronautics and Space Administration — Atomic Layer Deposition (ALD) a cost effective nano-manufacturing technique allows for the conformal coating of substrates with atomic control in a benign...

Atom diffraction with a 'natural' metastable atom nozzle beam

International Nuclear Information System (INIS)

Karam, J-C; Wipf, N; Grucker, J; Perales, F; Boustimi, M; Vassilev, G; Bocvarski, V; Mainos, C; Baudon, J; Robert, J

2005-01-01

The resonant metastability-exchange process is used to obtain a metastable atom beam with intrinsic properties close to those of a ground-state atom nozzle beam (small angular aperture, narrow velocity distribution). The estimated effective source diameter (15 μm) is small enough to provide at a distance of 597 mm a transverse coherence radius of about 873 nm for argon, 1236 nm for neon and 1660 nm for helium. It is demonstrated both by experiment and numerical calculations with He*, Ne* and Ar* metastable atoms, that this beam gives rise to diffraction effects on the transmitted angular pattern of a silicon-nitride nano-slit grating (period 100 nm). Observed patterns are in good agreement with previous measurements with He* and Ne* metastable atoms. For argon, a calculation taking into account the angular aperture of the beam (0.35 mrad) and the effect of the van der Waals interaction-the van der Waals constant C 3 1.83 +0.1 -0.15 au being derived from spectroscopic data-leads to a good agreement with experiment

Determination of tellurium by hydride generation with in situ trapping flame atomic absorption spectrometry

Energy Technology Data Exchange (ETDEWEB)

Matusiewicz, H.; Krawczyk, M. [Politechn Poznanska, Poznan (Poland)

2007-03-15

The analytical performance of coupled hydride generation - integrated atom trap (HG-IAT) atomizer flame atomic absorption spectrometry (FAAS) system was evaluated for determination of Te in reference material (GBW 07302 Stream Sediment), coal fly ash and garlic. Tellurium, using formation of H{sub 2}Te vapors, is atomized in air-acetylene flame-heated IAT. A new design HG-IAT-FAAS hyphenated technique that would exceed the operational capabilities of existing arrangernents (a water-cooled single silica tube, double-slotted quartz tube or an 'integrated trap') was investigated. An improvement in detection limit was achieved compared with using either of the above atom trapping techniques separately. The concentration detection limit, defined as 3 times the blank standard deviation (3{sigma}), was 0.9 ng mL{sup -1} for Te. For a 2 min in situ preconcentration time (sample volume of 2 mL), sensitivity enhancement compared to flame AAS, was 222 fold, using the hydride generation atom trapping technique. The sensitivity can be further improved by increasing the collection time. The precision, expressed as RSD, was 7.0% (n = 6) for Te. The accuracy of the method was verified using a certified reference material (GBW 07302 Stream Sediment) by aqueous standard calibration curves. The measured Te contents of the reference material was in agreement with the information value. The method was successfully applied to the determination of tellurium in coal fly ash and garlic.

Ultratrace determination of arsenic in water samples by electrothermal atomic absorption spectrometry after pre-concentration with Mg-Al-Fe ternary layered double hydroxide nano-sorbent.

Science.gov (United States)

Abdolmohammad-Zadeh, Hossein; Jouyban, Abolghasem; Amini, Roghayeh

2013-11-15

A selective solid phase extraction method, based on nano-structured Mg-Al-Fe(NO3(-)) ternary layered double hydroxide as a sorbent, is developed for the pre-concentration of ultra-trace levels of arsenic (As) prior to determination by electrothermal atomic absorption spectrometry. It is found that both As(III) and As(V) could be quantitatively retained on the sorbent within a wide pH range of 4-12. Accordingly, the presented method is applied to determination of total inorganic As in aqueous solutions. Maximum analytical signal of As is achieved when the pyrolysis and atomization temperatures are close to 900 °C and 2300 °C, respectively. Several variables affecting the extraction efficiency including pH, sample flow rate, amount of nano-sorbent, elution conditions and sample volume are optimized. Under the optimized conditions, the limit of detection (3Sb/m) and the relative standard deviation are 4.6 pg mL(-1) and 3.9%, respectively. The calibration graph is linear in the range of 15.0-650 pg mL(-1) with a correlation coefficient of 0.9979, sorption capacity and pre-concentration factor are 8.68 mg g(-1) and 300, respectively. The developed method is validated by the analysis of a standard reference material (SRM 1643e) and is successfully applied to the determination of ultra-trace amounts of As in different water samples. Copyright © 2013 Elsevier B.V. All rights reserved.

Preliminary evaluation of two radioiodinated maleimide derivatives targeting peripheral and membrane sulfhydryl groups for in vitro cell labeling

Energy Technology Data Exchange (ETDEWEB)

Amartey, John K., E-mail: amarjk48@hotmail.co [Cyclotron and Radiopharmaceuticals Department, P.O. Box 3354, Riyadh 11211 (Saudi Arabia); Parhar, Ranjit S. [Biological and Medical Research Department, P.O. Box 3354, Riyadh 11211 (Saudi Arabia); Shi, Yufei [Genetics Department, King Faisal Specialist Hospital and Research Centre, P.O. Box 3354, Riyadh 11211 (Saudi Arabia); Al-Mohanna, Futwan [Biological and Medical Research Department, P.O. Box 3354, Riyadh 11211 (Saudi Arabia)

2011-01-15

A factor impeding the advancement of cell mediated therapy is the inability to track these cells in vivo by noninvasive techniques. It has been shown that cells express high levels of sulfhydryl groups. We sought to explore these groups to covalently label cells with radiolabeled maleimide derivatives. Two maleimide derivatives; N-[2-(2,5-dioxoazolinyl)ethyl](5-iodo(3-pyridyl))carboxamide and N-[2-(2,5-dioxoazolinyl)ethyl](3-iodophenyl)carboxamide ([{sup 125}I]-4 and [{sup 125}I]-8) were synthesized and radioiodinated. These compounds were evaluated for in vitro binding to neutrophils, endothelial and mesenchymal stem cells, and biodistribution of the radiolabeled stem cells in nude mice. These radiotracers were obtained in moderate to high radiochemical yields. Binding to cells were moderate (20-60%/10{sup 6} cells) and the label was retained, although washout (an average of 18-55%) was observed depending on the cell type and the tracer used. The labeled cells initially localized in well perfused organs and at a later time showed a general distribution as expected. The novel tracers labeled several cell types and shown that the stability of the label and viability of the cells were maintained in vitro and in vivo for a reasonable period and warrant further in vivo investigation.

Review of Micro/Nano Nondestructive Evaluation Technique (II): Measurement of Acoustic Properties

International Nuclear Information System (INIS)

Kim, Chung Seok; Park, Ik Keun

2012-01-01

The present paper reviews the micro and nano nondestructive evaluation(NDE) technique that is possible to investigate the surface and measure the acoustic properties. The technical theory, features and applications of the ultrasonic atomic force microscopy(UAFM) and scanning acoustic microscopy(SAM) are illustrated. Especially, these technologies are possible to evaluate the mechanical properties in micro/nano structure and surface through the measurement of acoustic properties in addition to the observation of surface and subsurface. Consequently, it is thought that technique developments and applications of these micro/nano NDE in advanced industrial parts together with present nondestructive industry are widely possible hereafter.

Carbon nano tubes -Buckypaper- radiation studies for medical physics application

Energy Technology Data Exchange (ETDEWEB)

Alanazi, A.; Alkhorayef, M.; Dalton, A.; Bradley, D. A. [University of Surrey, Department of Physics, College for Nuclear and Radiation Physics, Guildford, Surrey GR2 7XH (United Kingdom); Alzimami, K. [King Saud University, Department of Radiological Sciences, P. O. Box 10219, Riyadh 11433 (Saudi Arabia); Abuhadi, N., E-mail: a.alanazi@surrey.ac.uk [Jazan University, Faculty of Medical Applied Sciences, Diagnostic Radiology Department, P. O. Box 114, Jazan (Saudi Arabia)

2015-10-15

Radiation dosimetry underpins safe and effective clinical applications of radiation. Many materials have been used to measure the radiation dose deposited in human tissue, their radiation response requiring the application of correction factors to account for various influencing factors, including sensitivity to dose and energy dependence. In regard to the latter, account needs to be taken of difference from the effective atomic number of human tissue, soft or calcified. Graphite ion chambers and semiconductor diode detectors have been used to make measurements in phantoms but these active devices represent a clear disadvantage when considered for in vivo dosimetry. In both circumstances, dosimeters with atomic number similar to human tissue are needed. Carbon nano tubes have properties that potentially meet the demand, requiring low voltage in active devices and an atomic number similar to adipose tissue. In this study, single-wall carbon nano tubes buckypaper has been used to measure the beta particle dose deposited from a strontium-90 source, the medium displaying thermoluminescence at potentially useful sensitivity. As an example, the samples show a clear response for a dose of 2 Gy. This finding suggests that carbon nano tubes can be used as a passive dosimeter specifically for the high levels of radiation exposures used in radiation therapy. Furthermore, the finding points towards further potential applications such as for space radiation measurements, not least because the medium satisfies a demand for light but strong materials of minimal capacitance. (Author)

Carbon nano tubes -Buckypaper- radiation studies for medical physics application

International Nuclear Information System (INIS)

Alanazi, A.; Alkhorayef, M.; Dalton, A.; Bradley, D. A.; Alzimami, K.; Abuhadi, N.

2015-10-01

Radiation dosimetry underpins safe and effective clinical applications of radiation. Many materials have been used to measure the radiation dose deposited in human tissue, their radiation response requiring the application of correction factors to account for various influencing factors, including sensitivity to dose and energy dependence. In regard to the latter, account needs to be taken of difference from the effective atomic number of human tissue, soft or calcified. Graphite ion chambers and semiconductor diode detectors have been used to make measurements in phantoms but these active devices represent a clear disadvantage when considered for in vivo dosimetry. In both circumstances, dosimeters with atomic number similar to human tissue are needed. Carbon nano tubes have properties that potentially meet the demand, requiring low voltage in active devices and an atomic number similar to adipose tissue. In this study, single-wall carbon nano tubes buckypaper has been used to measure the beta particle dose deposited from a strontium-90 source, the medium displaying thermoluminescence at potentially useful sensitivity. As an example, the samples show a clear response for a dose of 2 Gy. This finding suggests that carbon nano tubes can be used as a passive dosimeter specifically for the high levels of radiation exposures used in radiation therapy. Furthermore, the finding points towards further potential applications such as for space radiation measurements, not least because the medium satisfies a demand for light but strong materials of minimal capacitance. (Author)

Nano-scale Biophysical and Structural Investigations on Intact and Neuropathic Nerve Fibers by Simultaneous Combination of Atomic Force and Confocal Microscopy

Directory of Open Access Journals (Sweden)

Gonzalo Rosso

2017-08-01

Full Text Available The links between neuropathies of the peripheral nervous system (PNS, including Charcot-Marie-Tooth1A and hereditary neuropathy with liability to pressure palsies, and impaired biomechanical and structural integrity of PNS nerves remain poorly understood despite the medical urgency. Here, we present a protocol describing simultaneous structural and biomechanical integrity investigations on isolated nerve fibers, the building blocks of nerves. Nerve fibers are prepared from nerves harvested from wild-type and exemplary PNS neuropathy mouse models. The basic principle of the designed experimental approach is based on the simultaneous combination of atomic force microscopy (AFM and confocal microscopy. AFM is used to visualize the surface structure of nerve fibers at nano-scale resolution. The simultaneous combination of AFM and confocal microscopy is used to perform biomechanical, structural, and functional integrity measurements at nano- to micro-scale. Isolation of sciatic nerves and subsequent teasing of nerve fibers take ~45 min. Teased fibers can be maintained at 37°C in a culture medium and kept viable for up to 6 h allowing considerable time for all measurements which require 3–4 h. The approach is designed to be widely applicable for nerve fibers from mice of any PNS neuropathy. It can be extended to human nerve biopsies.

Nano-technology and nano-toxicology.

Science.gov (United States)

Maynard, Robert L

2012-01-01

Rapid developments in nano-technology are likely to confer significant benefits on mankind. But, as with perhaps all new technologies, these benefits are likely to be accompanied by risks, perhaps by new risks. Nano-toxicology is developing in parallel with nano-technology and seeks to define the hazards and risks associated with nano-materials: only when risks have been identified they can be controlled. This article discusses the reasons for concern about the potential effects on health of exposure to nano-materials and relates these to the evidence of the effects on health of the ambient aerosol. A number of hypotheses are proposed and the dangers of adopting unsubstantiated hypotheses are stressed. Nano-toxicology presents many challenges and will need substantial financial support if it is to develop at a rate sufficient to cope with developments in nano-technology.

Cold atoms near surfaces: designing potentials by sculpturing wires

International Nuclear Information System (INIS)

Della Pietra, Leonardo; Aigner, Simon; Hagen, Christoph vom; Lezec, Henri J; Schmiedmayer, Joerg

2005-01-01

The magnetic trapping potentials for atoms on atom chips are determined by the current flow pattern in the chip wires. By modifying the wire shape using focused ion beam nano-machining we can design specialized current flow patterns and therefore micro-design the magnetic trapping potentials. We give designs for a barrier, a quantum dot, and a double well or double barrier and show preliminary experiments with ultra cold atoms in these designed potentials

Green method for ultrasensitive determination of Hg in natural waters by electrothermal-atomic absorption spectrometry following sono-induced cold vapor generation and 'in-atomizer trapping'

International Nuclear Information System (INIS)

Gil, Sandra; Lavilla, Isela; Bendicho, Carlos

2007-01-01

Sono-induced cold vapor generation (SI-CVG) has been used for the first time in combination with a graphite furnace atomizer for determination of Hg in natural waters by electrothermal-atomic absorption spectrometry after in situ trapping onto a noble metal-pretreated platform (Pd, Pt or Rh) inserted into a graphite tube. The system allows 'in-atomizer trapping' of Hg without the use of conventional reduction reactions based on sodium borohydride or tin chloride in acid medium for cold vapor generation. The sono-induced reaction is accomplished by applying ultrasound irradiation to the sample solution containing Hg(II) in the presence of an organic compound such as formic acid. As this organic acid is partly degraded upon ultrasound irradiation to yield CO, CO 2 , H 2 and H 2 O, the amount of lab wastes is minimized and a green methodology is achieved. For this purpose, experimental variables influencing the generation/trapping process are fully investigated. The limit of detection for a 10 min trapping time and 10 mL sample volume was 0.03 μg L -1 (Integrated absorbance) and the repeatability expressed as relative standard deviation was about 3%. Carbonates and chlorides at 100 mg L -1 level caused a signal depression by 20-30%. The enhanced trapping efficiency observed with the sono-induced cold vapor generation as compared with 'in-atomizer trapping' methods employing chemical vapor generation is discussed. A reaction pathway for SI-CVG is proposed on the basis of the current knowledge for synthesis of noble metal nanoparticles by ultrasound

Surface coverage of Pt atoms on PtCo nanoparticles and catalytic kinetics for oxygen reduction

Energy Technology Data Exchange (ETDEWEB)

Jiang Rongzhong, E-mail: rongzhong.jiang@us.army.mi [Sensors and Electron Devices Directorate, U.S. Army Research Laboratory, 2800 Powder Mill Road, Adelphi, MD 20783-1197 (United States); Rong, Charles; Chu, Deryn [Sensors and Electron Devices Directorate, U.S. Army Research Laboratory, 2800 Powder Mill Road, Adelphi, MD 20783-1197 (United States)

2011-02-01

The surface coverage of Pt atoms on PtCo nanoparticles and its effect on catalytic kinetics for oxygen reduction were investigated. The PtCo nanoparticles with different surface coverage of Pt atoms were synthesized with various methods, including normal chemical method, microemulsion synthesis, and ultrasound-assisted microemulsion. A model of Pt atoms filling into a spherical nanoparticle was proposed to explain the relationship of surface metal atoms and nanoparticle size. The catalytic activity of the PtCo nano-particles is highly dependent on the synthetic methods, even if they have the same chemical composition. The PtCo nano-particles synthesized with ultrasound-assisted microemulsion showed the highest activity, which is attributed to an increase of active surface coverage of Pt atoms on the metal nanoparticles. The rate of oxygen reduction at 0.5 V (vs. SCE) catalyzed by the PtCo synthesized with ultrasound-assisted micro-emulsion was about four times higher than that of the PtCo synthesized with normal chemical method. As demonstrated with rotating-ring disk electrode measurement, the PtCo nano-particles can catalyze oxygen 4-electron reduction to water without intermediate H{sub 2}O{sub 2} detected.

Editorial Nano structures for Medicine and Pharmaceuticals

International Nuclear Information System (INIS)

Xing-Jie, L.; Kumar, A.; Donglu, S.; Daxiang, C.

2012-01-01

The rapid developments in nano structured materials and nano technology will have profound impact in many areas of biomedical applications including delivery of drugs and biomolecules, tissue engineering, detection of bio markers, cancer diagnosis, cancer therapy, and imaging. This field is expanding quickly, and a lot of work is ongoing in the design, characterization, synthesis, and application of materials, for controlling shape and size at nanometer scale to develop highly advanced materials for biomedical application and even to design better pharmaceutical products. In recent years, novel nano structure with multi functionalities has been focused on the use of nano structures toward solving problems of biology and medicine. The main scope of this special issue is to demonstrate the latest achievement of nano technology and its application in nano medicine particularly in new approaches for drug delivery such as targeted drug delivery system, nano structure for drug storage, nano materials for tissue engineering, medical diagnosis and treatment, and generation of new kinds of materials from biological sources. Therefore, many critical issues in nano structured materials, particularly their applications in biomedicine, must be addressed before clinical applications. This special issue devotes several review and research articles encompassing various aspects of nano materials for medicine and pharmaceuticals.

Generation of fast protons by interaction of modest laser intensities with H2O 'snow' nano-wire targets

International Nuclear Information System (INIS)

Bruner, Nir; Schleifer, Elad; Palchan, Tala; Pikuz, Sergey A.; Eisenmann, Shmuel; Botton, Mordechai; Gordon, Dan; Zigler, Arie

2011-01-01

We report on the generation of protons with energies of 5.5 MeV when irradiating an H 2 O nano-wire layer grown on a sapphire plate with an intensity of 5x10 17 W/cm 2 . A theoretical model is suggested in which plasma near the tip of the wire is subject to enhanced electrical fields and protons are accelerated to several MeVs.

Comparative study on nano-Zirconium Oxide Materials used in Nuclear Technology

International Nuclear Information System (INIS)

Khalil, T.; Dakroury, G.A.; Abou El-Nour, F.; Abdel-Khlik, M.

2004-01-01

Nano-ZrO 2 powders were prepared using two advanced methods, namely SoI-GeI and Gelation techniques. Y 2 O 3 , Ce0 2 and Mg0 were used as stabilizers during the preparation processes. The function of these materials is to stabilize the meta stable tetragonal Zr0 2 phase responsible for the nano character of produced materials. The applied experimental procedures proved to be suitable to produce nano powders composed of crystallites of few nano-meter size with an interfacial component formed by all atoms situated in the grain boundaries. These two structure components (nano-sized crystallites and boundaries) of comparable volume fractions are crucial for the nano-structure materials. Powder agglo-meration, contamination during processing and remaining of the residual pores in the bodies were overcome during the sintering process of the powder by special treatment. Different analytical procedures such as DTA-TG, specific surface area, pore size analysis, density, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were carried out for Zr0 2 produced by both SoI-GeI and Gelation techniques

48 CFR 225.104 - Nonavailable articles.

Science.gov (United States)

2010-10-01

... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Nonavailable articles. 225.104 Section 225.104 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM... Nonavailable articles. (a) DoD has determined that the following articles also are nonavailable in accordance...

48 CFR 225.503 - Group offers.

Science.gov (United States)

2010-10-01

... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Group offers. 225.503... OF DEFENSE SOCIOECONOMIC PROGRAMS FOREIGN ACQUISITION Evaluating Foreign Offers-Supply Contracts 225.503 Group offers. Evaluate group offers in accordance with FAR 25.503, but apply the evaluation...

48 CFR 225.7003-3 - Exceptions.

Science.gov (United States)

2010-10-01

... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Exceptions. 225.7003-3 Section 225.7003-3 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM... the recommendation of the Strategic Materials Protection Board pursuant to 10 U.S.C. 187, determines...

Fabrication of Nano-CeO2 and Application of Nano-CeO2 in Fe Matrix Composites

International Nuclear Information System (INIS)

Tiebao, W.; Chunxiang, C.; Xiaodong, W.; Guobin, L.

2010-01-01

It is expatiated that nano-CeO2 is fabricated by the direct sedimentation method. The components and particles diameter of nano-CeO2 powders are analyzed by XRD and SEM . The thermodynamic analysis and acting mechanism of nano-CeO2 with Al in Fe matrix composites are researched, which shows that the reaction is generated between CeO2 and Al in the composite, that is, 3CeO2+4Al - 2Al2O3+3[Ce], which obtains Al2O3 and active [Ce] during the sintering process. The active [Ce] can improve the performance of CeO2/Fe matrix composites. The suitable amount of CeO2 is about 0.05% in CeO2/Fe matrix composites. SEM fracture analysis shows that the toughness sockets in nano-CeO2/Fe matrix composites are more than those in no-added nano-CeO2 composites, which can explain that adding nano-CeO2 into Fe matrix composite, the toughness of the composite is improved significantly. Applied nano-CeO2 to Fe matrix diamond saw blades shows that Fe matrix diamond saw blade is sharper and of longer cutting life than that with no-added nano-CeO2.

Nano-Impact (Fatigue Characterization of As-Deposited Amorphous Nitinol Thin Film

Directory of Open Access Journals (Sweden)

Rehan Ahmed

2012-08-01

Full Text Available This paper presents nano-impact (low cycle fatigue behavior of as-deposited amorphous nitinol (TiNi thin film deposited on Si wafer. The nitinol film was 3.5 µm thick and was deposited by the sputtering process. Nano-impact tests were conducted to comprehend the localized fatigue performance and failure modes of thin film using a calibrated nano-indenter NanoTest™, equipped with standard diamond Berkovich and conical indenter in the load range of 0.5 mN to 100 mN. Each nano-impact test was conducted for a total of 1000 fatigue cycles. Depth sensing approach was adapted to understand the mechanisms of film failure. Based on the depth-time data and surface observations of films using atomic force microscope, it is concluded that the shape of the indenter test probe is critical in inducing the localized indentation stress and film failure. The measurement technique proposed in this paper can be used to optimize the design of nitinol thin films.

On Generation of Time-based Label Refinements

OpenAIRE

Tax, Niek; Alasgarov, Emin; Sidorova, Natalia; Haakma, Reinder

2016-01-01

Process mining is a research field focused on the analysis of event data with the aim of extracting insights in processes. Applying process mining techniques on data from smart home environments has the potential to provide valuable insights in (un)healthy habits and to contribute to ambient assisted living solutions. Finding the right event labels to enable application of process mining techniques is however far from trivial, as simply using the triggering sensor as the label for sensor even...

Tipping solutions: emerging 3D nano-fabrication/ -imaging technologies

Directory of Open Access Journals (Sweden)

Seniutinas Gediminas

2017-06-01

Full Text Available The evolution of optical microscopy from an imaging technique into a tool for materials modification and fabrication is now being repeated with other characterization techniques, including scanning electron microscopy (SEM, focused ion beam (FIB milling/imaging, and atomic force microscopy (AFM. Fabrication and in situ imaging of materials undergoing a three-dimensional (3D nano-structuring within a 1−100 nm resolution window is required for future manufacturing of devices. This level of precision is critically in enabling the cross-over between different device platforms (e.g. from electronics to micro-/nano-fluidics and/or photonics within future devices that will be interfacing with biological and molecular systems in a 3D fashion. Prospective trends in electron, ion, and nano-tip based fabrication techniques are presented.

25 CFR 225.33 - Assignment of minerals agreements.

Science.gov (United States)

2010-04-01

... 25 Indians 1 2010-04-01 2010-04-01 false Assignment of minerals agreements. 225.33 Section 225.33 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR ENERGY AND MINERALS OIL AND GAS, GEOTHERMAL, AND SOLID MINERALS AGREEMENTS Minerals Agreements § 225.33 Assignment of minerals agreements. An...

Ga N nano wires and nano tubes growth by chemical vapor deposition method at different NH{sub 3} flow rate

Energy Technology Data Exchange (ETDEWEB)

Li, P.; Liu, Y.; Meng, X. [Wuhan University, School of Physics and Technology, Key Laboratory of Artificial Micro and Nanostructures of Ministry of Education, Wuhan 430072 (China)

2016-11-01

Ga N nano wires and nano tubes have been successfully synthesized via the simple chemical vapor deposition method. NH{sub 3} flow rate was found to be a crucial factor in the synthesis of different type of Ga N which affects the shape and the diameter of generated Ga N nano structures. X-ray diffraction confirms that Ga N nano wires grown on Si(111) substrate under 900 degrees Celsius and with NH{sub 3} flow rate of 50 sc cm presents the preferred orientation growth in the (002) direction. It is beneficial to the growth of nano structure through catalyst annealing. Transmission electron microscopy and scanning electron microscopy were used to measure the size and structures of the samples. (Author)

Si{sub 2}Sb{sub 2}Te{sub 5} phase change material studied by an atomic force microscope nano-tip

Energy Technology Data Exchange (ETDEWEB)

Liu Yanbo; Min Guoquan; Zhang Jing; Zhou Weimin; Wan Yongzhong; Zhang Jianping; Li Xiaoli [Laboratory of Nano-Technology, Shanghai Nanotechnology Promotion Center, Shanghai 200237 (China); Zhang Ting; Niu Xiaoming; Song Zhitang; Feng Songlin, E-mail: liuyanbo@snpc.org.c, E-mail: tzhang@mail.sim.ac.c [State Key Laboratory of Functional Materials for Informatics, Laboratory of Nanotechnology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050 (China)

2009-06-01

The Si{sub 2}Sb{sub 2}Te{sub 5} phase change material has been studied by applying a nano-tip (30 nm in diameter) on an atomic force microscopy system. Memory switching from a high resistance state to a low resistance state has been achieved, with a resistance change of about 1000 times. In a typical I-V curve, the current increases significantly after the voltage exceeds approx4.3 V. The phase transformation of a Si{sub 2}Sb{sub 2}Te{sub 5} film was studied in situ by means of in situ X-ray diffraction and temperature dependent resistance measurements. The thermal stability of Si{sub 2}Sb{sub 2}Te{sub 5} and Ge{sub 2}Sb{sub 2}Te{sub 5} was characterized and compared as well.

Nano Mechanical Machining Using AFM Probe

Science.gov (United States)

Mostofa, Md. Golam

Complex miniaturized components with high form accuracy will play key roles in the future development of many products, as they provide portability, disposability, lower material consumption in production, low power consumption during operation, lower sample requirements for testing, and higher heat transfer due to their very high surface-to-volume ratio. Given the high market demand for such micro and nano featured components, different manufacturing methods have been developed for their fabrication. Some of the common technologies in micro/nano fabrication are photolithography, electron beam lithography, X-ray lithography and other semiconductor processing techniques. Although these methods are capable of fabricating micro/nano structures with a resolution of less than a few nanometers, some of the shortcomings associated with these methods, such as high production costs for customized products, limited material choices, necessitate the development of other fabricating techniques. Micro/nano mechanical machining, such an atomic force microscope (AFM) probe based nano fabrication, has, therefore, been used to overcome some the major restrictions of the traditional processes. This technique removes material from the workpiece by engaging micro/nano size cutting tool (i.e. AFM probe) and is applicable on a wider range of materials compared to the photolithographic process. In spite of the unique benefits of nano mechanical machining, there are also some challenges with this technique, since the scale is reduced, such as size effects, burr formations, chip adhesions, fragility of tools and tool wear. Moreover, AFM based machining does not have any rotational movement, which makes fabrication of 3D features more difficult. Thus, vibration-assisted machining is introduced into AFM probe based nano mechanical machining to overcome the limitations associated with the conventional AFM probe based scratching method. Vibration-assisted machining reduced the cutting forces

Nano technology

International Nuclear Information System (INIS)

Lee, In Sik

2002-03-01

This book is introduction of nano technology, which describes what nano technology is, alpha and omega of nano technology, the future of Korean nano technology and human being's future and nano technology. The contents of this book are nano period is coming, a engine of creation, what is molecular engineering, a huge nano technology, technique on making small things, nano materials with exorbitant possibility, the key of nano world the most desirable nano technology in bio industry, nano development plan of government, the direction of development for nano technology and children of heart.

Influence of beryllium ceramics nano-structuring by iron atoms on increase of their stability to ionizing radiations effect; Vliyanie nanostrukturirovaniya berillievykh keramik atomami zheleza na povyshenie ikh ustojchivosti k vozdejstviyu ioniziruyushchikh izluchenij

Energy Technology Data Exchange (ETDEWEB)

Polyakov, A I; Bitenbaev, M I [Fiziko-Tekhnicheskij Inst., Almaty (Kazakhstan)

2007-07-01

In the work a new results on beryllium ceramics nano-structuring effect by iron oxide atoms on radiation defects quantum yield value G in these materials and defects depth constants in ionizing radiation fields k are presented. Experimental data under dependence of G and k values from concentration of iron atoms in beryllium ceramic matrix are presented. It is shown, that structure modification of beryllium ceramics by feedings on the iron base leads to sharp decrease (almost in 30 times) of radiation defects quantum yield value, i.e. to increase of these ceramics stability enhancement to ionizing radiation effect.

2 CFR 225.55 - Information contact.

Science.gov (United States)

2010-01-01

... information concerning this part may be obtained by contacting the Office of Federal Financial Management, Financial Standards and Reporting Branch, Office of Management and Budget, Washington, DC 20503, telephone... 2 Grants and Agreements 1 2010-01-01 2010-01-01 false Information contact. 225.55 Section 225.55...

40 CFR 86.225-94 - [Reserved

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 18 2010-07-01 2010-07-01 false [Reserved] 86.225-94 Section 86.225-94 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF... Year Gasoline-Fueled New Light-Duty Vehicles, New Light-Duty Trucks and New Medium-Duty Passenger...

Micro/nano-fabrication technologies for cell biology.

Science.gov (United States)

Qian, Tongcheng; Wang, Yingxiao

2010-10-01

Micro/nano-fabrication techniques, such as soft lithography and electrospinning, have been well-developed and widely applied in many research fields in the past decade. Due to the low costs and simple procedures, these techniques have become important and popular for biological studies. In this review, we focus on the studies integrating micro/nano-fabrication work to elucidate the molecular mechanism of signaling transduction in cell biology. We first describe different micro/nano-fabrication technologies, including techniques generating three-dimensional scaffolds for tissue engineering. We then introduce the application of these technologies in manipulating the physical or chemical micro/nano-environment to regulate the cellular behavior and response, such as cell life and death, differentiation, proliferation, and cell migration. Recent advancement in integrating the micro/nano-technologies and live cell imaging are also discussed. Finally, potential schemes in cell biology involving micro/nano-fabrication technologies are proposed to provide perspectives on the future research activities.

Factors affecting the labeling efficiency and stability of technetium-99m-labeled glucoheptonate

International Nuclear Information System (INIS)

Zbrzeznj, D.J.; Khan, R.A.

1981-01-01

Factors influencing the labeling efficiency and in vitro stability of 99 mTc-labeled glucoheptonate (Tc-GH) were investigated. Using commercially available glucoheptonate kits (New England Nuclear), the following factors were studied: (1) amount of activity added to each kit vial, (2) different brands of 0.9% sodium chloride injection, (3) evaluation of eluates from three commercially available generators, (4) different chromatography systems, (5) storage of the preparation at room temperature and under refrigeration, and (6) labeling with eluates obtained at various times (6, 24, 48, 72, and 96 hours) since previous elution of the generator. Results showed that Tc-GH prepared using 100 mCi of sodium pertechnetate from a Mallinckrodt generator, low-dissolved-oxygen 0.9% sodium chloride injection to make up a constant 5-ml volume, and chromatography with methyl ethyl ketone/sodium chloride on an ITLC-SG system gave the best labeling efficiency over a 24-hour period. Storage temperature and time since previous elution had no effect on labeling efficiency or stability

Study On In Vitro Variation Generation Of Cymbidium Labell Anna Belle By Gamma Co-60 Irradiation

International Nuclear Information System (INIS)

Nguyen Huynh Phuong Uyen; Vo Thi Thu Ha; Le Quang Luan

2011-01-01

Radiation ionization is one of useful methods for mutation breeding of plants. In this study, γ-ray (Co-60) was used for generating morphological variations of Cymbidium Labell Anna Belle. The lethal doses of 50% samples (LD 50 ) after 4 months cultivation were determined at 35.0 Gy for protocorm like bodies (PLBs), 37.4 Gy for in vitro shoot bubs and 70.1 Gy for plantlets. PLBs were found as suitable samples for generation of variation of mentioned Cymbidium. The dose range from 20 to 50 Gy was determined with a high ability of variation on C. Labell Anna Belle. The highest frequency of variation was obtained ca. 3.82 x 10 -3 at the dose of 30 Gy. 157 in vitro variant plantlets were selected in M 1 V 1 generation, among variations, the variations were mainly found with 5 following types: removal of chlorophyll (8 plantlets), the leaves become shorter (64 plantlets), the leaves become longer (64 plantlets), increase of leaf number (11 plantlets) and the colour of pericardium was changed from green into violet (10 plantlets). Twenty one variant lines were selected in M 1 V 2 generation. (author)

Multiple microflame quartz tube atomizer: Study and minimization of interferences in quartz tube atomizers in hydride generation atomic absorption spectrometry

Energy Technology Data Exchange (ETDEWEB)

Moraes Flores, Erico Marlon de [Departamento de Quimica, Universidade Federal de Santa Maria, 97105-900, Santa Maria, RS (Brazil)], E-mail: flores@quimica.ufsm.br; Medeiros Nunes, Adriane; Luiz Dressler, Valderi [Departamento de Quimica, Universidade Federal de Santa Maria, 97105-900, Santa Maria, RS (Brazil); Dedina, Jiri [Institute of Analytical Chemistry of the ASCR, v.v.i., Videnska 1083, CZ-142 20 Prague (Czech Republic)

2009-02-15

A systematic study was performed to evaluate the performance of a multiple microflame (MM) quartz tube atomizer (QTA) for minimizing interferences and to improve the extent of the calibration range using a batch system for hydride generation atomic absorption spectrometry (HG AAS). A comparison of the results with conventional QTA on the determination of antimony, arsenic, bismuth and selenium was performed. The interference of As, Bi, Se, Pb, Sn and Sb was investigated using QTA and MMQTA atomizers. Better performance was found for MMQTA, and no loss of linearity was observed up to 160 ng for Se and Sb and 80 ng for As, corresponding to an enhancement of two times for both analytes when compared to QTA (analyte mass refers to a volume of 200 {mu}l). For Bi, the linear range was the same for QTA and MMQTA (140 ng). With the exception of Bi, the tolerance limits for hydride-forming elements were improved more than 50% in comparison to the conventional QTA system, especially for the interferences of As, Sb and Se. However, for Sn as an interferent, no difference was observed in the determination of Se and Sb using the MMQTA system. The use of MMQTA-HG AAS complied with the relatively high sensitivity of conventional QTA and also provided better performance for interferences and the linear range of calibration.

7 CFR 225.1 - General purpose and scope.

Science.gov (United States)

2010-01-01

... 7 Agriculture 4 2010-01-01 2010-01-01 false General purpose and scope. 225.1 Section 225.1... AGRICULTURE CHILD NUTRITION PROGRAMS SUMMER FOOD SERVICE PROGRAM General § 225.1 General purpose and scope... primary purpose of the Program is to provide food service to children from needy areas during periods when...

Label-free quantification of Tacrolimus in biological samples by atomic force microscopy

International Nuclear Information System (INIS)

Menotta, Michele; Biagiotti, Sara; Streppa, Laura; Rossi, Luigia; Magnani, Mauro

2015-01-01

Highlights: • Tacrolimus is a potent immunosuppressant drug that has to be continually monitored. • We present an atomic force microscope approach for quantification of Tacrolimus in blood samples. • Detection and quantification have been successfully achieved. - Abstract: In the present paper we describe an atomic force microscopy (AFM)-based method for the quantitative analysis of FK506 (Tacrolimus) in whole blood (WB) samples. Current reference methods used to quantify this immunosuppressive drug are based on mass spectrometry. In addition, an immunoenzymatic assay (ELISA) has been developed and is widely used in clinic, even though it shows a small but consistent overestimation of the actual drug concentration when compared with the mass spectrometry method. The AFM biosensor presented herein utilises the endogen drug receptor, FKBP12, to quantify Tacrolimus levels. The biosensor was first assayed to detect the free drug in solution, and subsequently used for the detection of Tacrolimus in blood samples. The sensor was suitable to generate a dose–response curve in the full range of clinical drug monitoring. A comparison with the clinically tested ELISA assay is also reported

Label-free quantification of Tacrolimus in biological samples by atomic force microscopy

Energy Technology Data Exchange (ETDEWEB)

Menotta, Michele, E-mail: michele.menotta@uniurb.it [Department of Biomolecular Sciences, University of Urbino “Carlo Bo” via Saffi 2, Urbino (Italy); Biagiotti, Sara [Department of Biomolecular Sciences, University of Urbino “Carlo Bo” via Saffi 2, Urbino (Italy); Streppa, Laura [Physics Laboratory, CNRS-ENS, UMR 5672, Lyon (France); Cell and Molecular Biology Laboratory, CNRS-ENS Lyon, UMR 5239, IFR128, Lyon (France); Rossi, Luigia; Magnani, Mauro [Department of Biomolecular Sciences, University of Urbino “Carlo Bo” via Saffi 2, Urbino (Italy)

2015-07-16

Highlights: • Tacrolimus is a potent immunosuppressant drug that has to be continually monitored. • We present an atomic force microscope approach for quantification of Tacrolimus in blood samples. • Detection and quantification have been successfully achieved. - Abstract: In the present paper we describe an atomic force microscopy (AFM)-based method for the quantitative analysis of FK506 (Tacrolimus) in whole blood (WB) samples. Current reference methods used to quantify this immunosuppressive drug are based on mass spectrometry. In addition, an immunoenzymatic assay (ELISA) has been developed and is widely used in clinic, even though it shows a small but consistent overestimation of the actual drug concentration when compared with the mass spectrometry method. The AFM biosensor presented herein utilises the endogen drug receptor, FKBP12, to quantify Tacrolimus levels. The biosensor was first assayed to detect the free drug in solution, and subsequently used for the detection of Tacrolimus in blood samples. The sensor was suitable to generate a dose–response curve in the full range of clinical drug monitoring. A comparison with the clinically tested ELISA assay is also reported.

Nano surface generation of grinding process using carbon nano tubes

Indian Academy of Sciences (India)

These results indicate that CNTs can be used as an additive in the lubricant. ... bles stacked, one-atom-thick sheets of chicken wire — a planar network of ... This type of oil is widely used in large component manufacturing .... Normally arc-.

Quasideterministic generation of maximally entangled states of two mesoscopic atomic ensembles by adiabatic quantum feedback

International Nuclear Information System (INIS)

Di Lisi, Antonio; De Siena, Silvio; Illuminati, Fabrizio; Vitali, David

2005-01-01

We introduce an efficient, quasideterministic scheme to generate maximally entangled states of two atomic ensembles. The scheme is based on quantum nondemolition measurements of total atomic populations and on adiabatic quantum feedback conditioned by the measurements outputs. The high efficiency of the scheme is tested and confirmed numerically for ideal photodetection as well as in the presence of losses

Evaluation of Steadiness and Drop Size Distribution in Sprays Generated by Different Twin-Fluid Atomizers

Directory of Open Access Journals (Sweden)

Zaremba Matouš

2015-01-01

Full Text Available Twin-fluid atomizers underwent a significant development during the last few decades. They are common in many industrial applications such as fuel spraying, melt atomization and food processing. This paper is focused on the evaluation of four different twin-fluid atomizers. The aim is to compare the quality of sprays generated by various atomizers with similar dimensions and in the same operating regimes. A phase- Doppler anemometry (PDA and particle image velocimetry (PIV were used to measure spray characteristics such as velocity and size of the droplets. Measured data were used to compare droplet size distribution and to evaluate steadiness of the spray. Visualisations were made to support measured data and to clarify the principles of primary atomization and its influence on the spray.

Evaluation of Steadiness and Drop Size Distribution in Sprays Generated by Different Twin-Fluid Atomizers

Science.gov (United States)

Zaremba, Matouš; Mlkvik, Marek; Malý, Milan; Jedelský, Jan; Jícha, Miroslav

2015-05-01

Twin-fluid atomizers underwent a significant development during the last few decades. They are common in many industrial applications such as fuel spraying, melt atomization and food processing. This paper is focused on the evaluation of four different twin-fluid atomizers. The aim is to compare the quality of sprays generated by various atomizers with similar dimensions and in the same operating regimes. A phase- Doppler anemometry (PDA) and particle image velocimetry (PIV) were used to measure spray characteristics such as velocity and size of the droplets. Measured data were used to compare droplet size distribution and to evaluate steadiness of the spray. Visualisations were made to support measured data and to clarify the principles of primary atomization and its influence on the spray.

Effects of electron-phonon interaction on thermal and electrical transport through molecular nano-conductors

Energy Technology Data Exchange (ETDEWEB)

Lü, Jing-Tao, E-mail: jtlu@hust.edu.cn [School of Physics, Huazhong University of Science and Technology, 430074 Wuhan (China); Zhou, Hangbo [Department of Physics and Center for Computational Science and Engineering, National University of Singapore, 117551 Singapore (Singapore); NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore, 117456 Singapore (Singapore); Jiang, Jin-Wu [Shanghai Institute of Applied Mathematics and Mechanics, Shanghai Key Laboratory of Mechanics in Energy Engineering, Shanghai University, 200072 Shanghai (China); Wang, Jian-Sheng [Department of Physics and Center for Computational Science and Engineering, National University of Singapore, 117551 Singapore (Singapore)

2015-05-15

The topic of this review is the effects of electron-phonon interaction (EPI) on the transport properties of molecular nano-conductors. A nano-conductor connects to two electron leads and two phonon leads, possibly at different temperatures or chemical potentials. The EPI appears only in the nano-conductor. We focus on its effects on charge and energy transport. We introduce three approaches. For weak EPI, we use the nonequilibrium Green’s function method to treat it perturbatively. We derive the expressions for the charge and heat currents. For weak system-lead couplings, we use the quantum master equation approach. In both cases, we use a simple single level model to study the effects of EPI on the system’s thermoelectric transport properties. It is also interesting to look at the effect of currents on the dynamics of the phonon system. For this, we derive a semi-classical generalized Langevin equation to describe the nano-conductor’s atomic dynamics, taking the nonequilibrium electron system, as well as the rest of the atomic degrees of freedom as effective baths. We show simple applications of this approach to the problem of energy transfer between electrons and phonons.

Effects of electron-phonon interaction on thermal and electrical transport through molecular nano-conductors

International Nuclear Information System (INIS)

Lü, Jing-Tao; Zhou, Hangbo; Jiang, Jin-Wu; Wang, Jian-Sheng

2015-01-01

The topic of this review is the effects of electron-phonon interaction (EPI) on the transport properties of molecular nano-conductors. A nano-conductor connects to two electron leads and two phonon leads, possibly at different temperatures or chemical potentials. The EPI appears only in the nano-conductor. We focus on its effects on charge and energy transport. We introduce three approaches. For weak EPI, we use the nonequilibrium Green’s function method to treat it perturbatively. We derive the expressions for the charge and heat currents. For weak system-lead couplings, we use the quantum master equation approach. In both cases, we use a simple single level model to study the effects of EPI on the system’s thermoelectric transport properties. It is also interesting to look at the effect of currents on the dynamics of the phonon system. For this, we derive a semi-classical generalized Langevin equation to describe the nano-conductor’s atomic dynamics, taking the nonequilibrium electron system, as well as the rest of the atomic degrees of freedom as effective baths. We show simple applications of this approach to the problem of energy transfer between electrons and phonons

MICRO & NANO TECHNOLOGIES – APPLICATIONS, DESIGN AND INTEGRATION

Directory of Open Access Journals (Sweden)

Dorin LEŢ

2010-05-01

Full Text Available The science of micro-nano technologies represents a multidisciplinary research domain, which provokes active participation of specialist from multiple domains (physics, chemistry, biology, mathematics, electronics, medicine, a.o.. Nanotechnology is an applied science domain focusing the design, synthesis and characterization of materials and devices starting from individual atoms and molecules level up to supramolecular level of strains of molecules with 100 molecular diameters. Operations at this dimensions implies the understanding of new scientific principles and new materials properties, which take place at micro and nano scale and are used in the development of materials, devices and systems with new and improved functions and performances. The properties and basic functions of structures and material systems at nano scale may be changed based on the organization of the living mater on molecular “weak” interactions (hydrogen binds, electrostatic dipole, Van der Waals forces, surface forces, electrofluidic forces, a.o..