WorldWideScience

Sample records for channel-impermeant thiol-reactive probes

  1. Two redox centers within Yap1 for H2O2 and thiol-reactive chemicals signaling.

    Science.gov (United States)

    Azevedo, Dulce; Tacnet, Frédérique; Delaunay, Agnès; Rodrigues-Pousada, Claudina; Toledano, Michel B

    2003-10-15

    The Yap1 transcription factor regulates yeast responses to H2O2 and to several unrelated chemicals and metals. Activation by H2O2 involves Yap1 Cys303-Cys598 intra-molecular disulfide bond formation directed by the H2O2 sensor Orp1/Gpx3. We show here that the electrophile N-ethylmaleimide activates Yap1 by covalent modification of Yap1 C-terminal Cys598, Cys620, and Cys629, in an Orp1 and Yap1-oxidation-independent way, thus establishing an alternate and distinct mode of Yap1 activation. We also show that menadione, a superoxide anion generator and a highly reactive electrophile, operates both modes of Yap1 activation. Further, the Yap1 C-terminal domain reactivity towards other electrophiles (4-hydroxynonenal, iodoacetamide) and metals (cadmium, selenium) suggests a common mechanism for sensing thiol reactive chemicals, involving thiol chemical modification. We propose that Yap1 has two distinct molecular redox centers, one triggered by ROS (hydroperoxides and the superoxide anion) and the other by chemicals with thiol reactivity (electrophiles and divalent heavy metals cations). These data indicate that yeast cells cannot sense these compounds through the same molecular devices, albeit they are all electrophilic. PMID:14556853

  2. Covalent modification of mutant rat P2X2 receptors with a thiol-reactive fluorophore allows channel activation by zinc or acidic pH without ATP.

    Directory of Open Access Journals (Sweden)

    Shlomo S Dellal

    Full Text Available Rat P2X2 receptors open at an undetectably low rate in the absence of ATP. Furthermore, two allosteric modulators, zinc and acidic pH, cannot by themselves open these channels. We describe here the properties of a mutant receptor, K69C, before and after treatment with the thiol-reactive fluorophore Alexa Fluor 546 C(5-maleimide (AM546. Xenopus oocytes expressing unmodified K69C were not activated under basal conditions nor by 1,000 µM ATP. AM546 treatment caused a small increase in the inward holding current which persisted on washout and control experiments demonstrated this current was due to ATP independent opening of the channels. Following AM546 treatment, zinc (100 µM or acidic external solution (pH 6.5 elicited inward currents when applied without any exogenous ATP. In the double mutant K69C/H319K, zinc elicited much larger inward currents, while acidic pH generated outward currents. Suramin, which is an antagonist of wild type receptors, behaved as an agonist at AM546-treated K69C receptors. Several other cysteine-reactive fluorophores tested on K69C did not cause these changes. These modified receptors show promise as a tool for studying the mechanisms of P2X receptor activation.

  3. Roles of the Yap1 transcription factor and antioxidants in Saccharomyces cerevisiae's tolerance to furfural and 5-hydroxymethylfurfural, which function as thiol-reactive electrophiles generating oxidative stress.

    Science.gov (United States)

    Kim, Daehee; Hahn, Ji-Sook

    2013-08-01

    Development of the tolerance of Saccharomyces cerevisiae strains to furfural and 5-hydroxymethylfurfural (HMF) is an important issue for cellulosic ethanol production. Although furfural and HMF are known to induce oxidative stress, the underlying mechanisms are largely unknown. In this study, we show that both furfural and HMF act as thiol-reactive electrophiles, thus directly activating the Yap1 transcription factor via the H2O2-independent pathway, depleting cellular glutathione (GSH) levels, and accumulating reactive oxygen species in Saccharomyces cerevisiae. However, furfural showed higher reactivity than did HMF toward GSH in vitro and in vivo. In line with such toxic mechanisms, overexpression of YAP1(C620F), a constitutively active mutant of YAP1, and Yap1 target genes encoding catalases (CTA1 and CTT1) increased tolerance to furfural and HMF. However, increasing GSH levels by overexpression of genes for GSH biosynthesis (GSH1 and GLR1) or by the exogenous addition of GSH to the culture medium enhanced tolerance to furfural but not to HMF.

  4. Roles of the Yap1 transcription factor and antioxidants in Saccharomyces cerevisiae's tolerance to furfural and 5-hydroxymethylfurfural, which function as thiol-reactive electrophiles generating oxidative stress.

    Science.gov (United States)

    Kim, Daehee; Hahn, Ji-Sook

    2013-08-01

    Development of the tolerance of Saccharomyces cerevisiae strains to furfural and 5-hydroxymethylfurfural (HMF) is an important issue for cellulosic ethanol production. Although furfural and HMF are known to induce oxidative stress, the underlying mechanisms are largely unknown. In this study, we show that both furfural and HMF act as thiol-reactive electrophiles, thus directly activating the Yap1 transcription factor via the H2O2-independent pathway, depleting cellular glutathione (GSH) levels, and accumulating reactive oxygen species in Saccharomyces cerevisiae. However, furfural showed higher reactivity than did HMF toward GSH in vitro and in vivo. In line with such toxic mechanisms, overexpression of YAP1(C620F), a constitutively active mutant of YAP1, and Yap1 target genes encoding catalases (CTA1 and CTT1) increased tolerance to furfural and HMF. However, increasing GSH levels by overexpression of genes for GSH biosynthesis (GSH1 and GLR1) or by the exogenous addition of GSH to the culture medium enhanced tolerance to furfural but not to HMF. PMID:23793623

  5. Thiol-reactivity of the fungicide maneb

    Directory of Open Access Journals (Sweden)

    James R. Roede

    2014-01-01

    Full Text Available Maneb (MB is a manganese-containing ethylene bis-dithiocarbamate fungicide that is implicated as an environmental risk factor for Parkinson's disease, especially in combination with paraquat (PQ. Dithiocarbamates inhibit aldehyde dehydrogenases, but the relationship of this to the combined toxicity of MB + PQ is unclear because PQ is an oxidant and MB activates Nrf2 and increases cellular GSH without apparent oxidative stress. The present research investigated the direct reactivity of MB with protein thiols using recombinant thioredoxin-1 (Trx1 as a model protein. The results show that MB causes stoichiometric loss of protein thiols, reversibly dimerizes the protein and inhibits its enzymatic activity. MB reacted at similar rates with low-molecular weight, thiol-containing chemicals. Together, the data suggest that MB can potentiate neurotoxicity of multiple agents by disrupting protein thiol functions in a manner analogous to that caused by oxidative stress, but without GSH depletion.

  6. Thiol-reactivity of the fungicide maneb.

    Science.gov (United States)

    Roede, James R; Jones, Dean P

    2014-01-01

    Maneb (MB) is a manganese-containing ethylene bis-dithiocarbamate fungicide that is implicated as an environmental risk factor for Parkinson's disease, especially in combination with paraquat (PQ). Dithiocarbamates inhibit aldehyde dehydrogenases, but the relationship of this to the combined toxicity of MB + PQ is unclear because PQ is an oxidant and MB activates Nrf2 and increases cellular GSH without apparent oxidative stress. The present research investigated the direct reactivity of MB with protein thiols using recombinant thioredoxin-1 (Trx1) as a model protein. The results show that MB causes stoichiometric loss of protein thiols, reversibly dimerizes the protein and inhibits its enzymatic activity. MB reacted at similar rates with low-molecular weight, thiol-containing chemicals. Together, the data suggest that MB can potentiate neurotoxicity of multiple agents by disrupting protein thiol functions in a manner analogous to that caused by oxidative stress, but without GSH depletion. PMID:24936438

  7. Mobile Probing and Probes

    DEFF Research Database (Denmark)

    Duvaa, Uffe; Ørngreen, Rikke; Weinkouff Mathiasen, Anne-Gitte;

    2013-01-01

    Mobile probing is a method, developed for learning about digital work situations, as an approach to discover new grounds. The method can be used when there is a need to know more about users and their work with certain tasks, but where users at the same time are distributed (in time and space...... to mobile probing being a flexible method for uncovering the unknowns, as a way of getting rich data to the analysis and design phases. On the other hand it is difficult to engage users to give in depth explanations, which seem easier in synchronous dialogs (whether online or face2face). The development...

  8. Mobile Probing and Probes

    DEFF Research Database (Denmark)

    Duvaa, Uffe; Ørngreen, Rikke; Weinkouff, Anne-Gitte;

    2012-01-01

    Mobile probing is a method, which has been developed for learning about digital work situations, as an approach to discover new grounds. The method can be used when there is a need to know more about users and their work with certain tasks, but where users at the same time are distributed (in time...... point to mobile probing being a flexible method for uncovering the unknowns, as a way of getting rich data to the analysis and design phases. On the other hand it is difficult to engage users to give in depth explanations, which seem easier in synchronous dialogs (whether online or face2face...

  9. Neuronal acid-induced [Zn²⁺]i elevations calibrated using the low-affinity ratiometric probe FuraZin-1.

    Science.gov (United States)

    Kiedrowski, Lech

    2015-11-01

    The experiments were carried out on primary cultures of murine cortical neurons from cryopreserved preparations obtained from embryonic-day-16 fetuses. To calibrate acid-induced intracelluar [Zn(2+) ] ([Zn(2+) ]i ) elevations, a low affinity (Kd = 39 μM at pH 6.1) ratiometric Zn(2+) probe, FuraZin-1, was used. A pHi drop from 7.2 to 6.1 caused [Zn(2+) ]i elevations reaching 2 μM; when the thiol-reactive agent N-ethylmaleimide (NEM) was subsequently applied, [Zn(2+) ]i increased further to 5.6 μM; analogous acid- and NEM-induced [Zn(2+) ]i elevations could also be detected but not calibrated, using the high affinity Zn(2+) probe FluoZin-3. The data indicate that NEM causes Zn(2+) release from ligands that chelate Zn(2+) at pH 6.1. ATP could also chelate Zn(2+) at pH 6.1 because its pKa is about 6.8. Therefore, it was tested whether an ATP depletion affects the acid-induced [Zn(2+) ]i elevations. The ATP depletion was induced by inhibiting mitochondrial and glycolytic ATP production. Interestingly, an almost complete ATP depletion (confirmed using a luciferin/luciferase assay) failed to affect the acid-induced [Zn(2+) ]i increases. These data suggest that the total amount of Zn(2+) accumulated in intracellular ATP-dependent stores (Zn(2+) -ATP complexes and organelles that accumulate Zn(2+) in an ATP-dependent manner) is negligible compared to the amount of Zn(2+) accumulated in the acid-sensitive intracellular ligands. In vitro, upon acidification, Zn(2+) -cysteine complexes release Zn(2+) and ATP chelates the released Zn(2+) . However, in vivo (cultured neurons), an ATP depletion failed to enhance acid-induced [Zn(2+) ]i elevations. These [Zn(2+) ]i elevations were calibrated using a low affinity ratiometric probe FuraZin-1; they reached 2 µM levels and increased to 5 µM when a thiol-reactive agent, N-ethylmaleimide, compromised Zn(2+) binding by cysteines. PMID:26263185

  10. Probe Storage

    NARCIS (Netherlands)

    Gemelli, Marcellino; Abelmann, Leon; Engelen, Johan B.C.; Khatib, Mohammed G.; Koelmans, Wabe W.; Zaboronski, Olog; Campardo, Giovanni; Tiziani, Federico; Laculo, Massimo

    2011-01-01

    This chapter gives an overview of probe-based data storage research over the last three decades, encompassing all aspects of a probe recording system. Following the division found in all mechanically addressed storage systems, the different subsystems (media, read/write heads, positioning, data chan

  11. Probing Capacity

    CERN Document Server

    Asnani, Himanshu; Weissman, Tsachy

    2010-01-01

    We consider the problem of optimal probing of states of a channel by transmitter and receiver for maximizing rate of reliable communication. The channel is discrete memoryless (DMC) with i.i.d. states. The encoder takes probing actions dependent on the message. It then uses the state information obtained from probing causally or non-causally to generate channel input symbols. The decoder may also take channel probing actions as a function of the observed channel output and use the channel state information thus acquired, along with the channel output, to estimate the message. We refer to the maximum achievable rate for reliable communication for such systems as the 'Probing Capacity'. We characterize this capacity when the encoder and decoder actions are cost constrained. To motivate the problem, we begin by characterizing the trade-off between the capacity and fraction of channel states the encoder is allowed to observe, while the decoder is aware of channel states. In this setting of 'to observe or not to o...

  12. DNA probes

    International Nuclear Information System (INIS)

    The creation of DNA probes for detection of specific nucleotide segments differs from ligand detection in that it is a chemical rather than an immunological reaction. Complementary DNA or RNA is used in place of the antibody and is labelled with 32P. So far, DNA probes have been successfully employed in the diagnosis of inherited disorders, infectious diseases, and for identification of human oncogenes. The latest approach to the diagnosis of communicable and parasitic infections is based on the use of deoxyribonucleic acid (DNA) probes. The genetic information of all cells is encoded by DNA and DNA probe approach to identification of pathogens is unique because the focus of the method is the nucleic acid content of the organism rather than the products that the nucleic acid encodes. Since every properly classified species has some unique nucleotide sequences that distinguish it from every other species, each organism's genetic composition is in essence a finger print that can be used for its identification. In addition to this specificity, DNA probes offer other advantages in that pathogens may be identified directly in clinical specimens

  13. Proximal Probes Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The Proximal Probes Facility consists of laboratories for microscopy, spectroscopy, and probing of nanostructured materials and their functional properties. At the...

  14. Probe tip heating assembly

    Energy Technology Data Exchange (ETDEWEB)

    Schmitz, Roger William; Oh, Yunje

    2016-10-25

    A heating assembly configured for use in mechanical testing at a scale of microns or less. The heating assembly includes a probe tip assembly configured for coupling with a transducer of the mechanical testing system. The probe tip assembly includes a probe tip heater system having a heating element, a probe tip coupled with the probe tip heater system, and a heater socket assembly. The heater socket assembly, in one example, includes a yoke and a heater interface that form a socket within the heater socket assembly. The probe tip heater system, coupled with the probe tip, is slidably received and clamped within the socket.

  15. Automated radiochemical synthesis of [{sup 18}F]FBEM: A thiol reactive synthon for radiofluorination of peptides and proteins

    Energy Technology Data Exchange (ETDEWEB)

    Kiesewetter, Dale O., E-mail: dk7k@nih.go [Laboratory of Molecular Imaging and Nanomedicine (LOMIN), National Institute of Biomedical Imaging and Bioengineering (NIBIB), National Institutes of Health - NIH, Building 10, Room 1C401, MSC 1180, Bethesda, MD 20892 (United States); Jacobson, Orit; Lang Lixin; Chen Xiaoyuan [Laboratory of Molecular Imaging and Nanomedicine (LOMIN), National Institute of Biomedical Imaging and Bioengineering (NIBIB), National Institutes of Health - NIH, Building 10, Room 1C401, MSC 1180, Bethesda, MD 20892 (United States)

    2011-02-15

    The automated radiochemical synthesis of N-[2-(4-[{sup 18}F]fluorobenzamido)ethyl]maleimide ([{sup 18}F]FBEM, IUPAC name: N-maleoylethyl-4-[{sup 18}F]fluorobenzamide), a prosthetic group for radiolabeling the free sulfhydryl groups of peptides and proteins, is herein described. 4-[{sup 18}F]fluorobenzoic acid was first prepared by nucleophilic displacement of a trimethylammonium moiety on a pentamethylbenzyl benzoate ester with [{sup 18}F]fluoride. In the second step the ester was cleaved under acidic conditions. Finally, 4-[{sup 18}F]fluorobenzoic acid was coupled to N-(2-aminoethyl)maleimide using diethylcyanophosphate and diisopropylethyl amine. Following high-performance liquid chromatography (HPLC) purification, [{sup 18}F]FBEM was obtained in 17.3{+-}7.1% yield (not decay corrected) in approximately 95 min. Isolation from the HPLC eluate and preparation for subsequent use, which was conducted manually, required an additional 10-15 min. The measured specific activity for three batches was 181.3, 251.6, and 351.5 GBq/ {mu}mol at the end of bombardment (EOB).

  16. THE ORNL ATOM PROBE

    OpenAIRE

    Miller, M

    1986-01-01

    The ORNL Atom Probe is a microanalytical tool for studies in materials science. The instrument is a combination of a customized version of the vacuum system of the VG FIM-100 atom probe, an ORNL-designed microcomputer-controlled digital timing system, and a double curved CEMA Imaging Atom Probe detector. The atom probe combines four instruments into one - namely a field ion microscope, an energy compensated time-of-flight mass spectrometer, an imaging atom probe, and a pulsed laser atom probe.

  17. Mobile Game Probes

    DEFF Research Database (Denmark)

    Borup Lynggaard, Aviaja

    2006-01-01

    This paper will examine how probes can be useful for game designers in the preliminary phases of a design process. The work is based upon a case study concerning pervasive mobile phone games where Mobile Game Probes have emerged from the project. The new probes are aimed towards a specific target...... group and the goal is to specify the probes so they will cover the most relevant areas for our project. The Mobile Game Probes generated many interesting results and new issues occurred, since the probes came to be dynamic and favorable for the process in new ways....

  18. Traversing probe system

    International Nuclear Information System (INIS)

    This invention comprises a rotatable annular probe-positioner which carries at least one radially disposed sensing probe, such as a Pitot tube having a right-angled tip. The positioner can be coaxially and rotatably mounted within a compressor casing or the like and then actuated to orient the sensing probe as required to make measurements at selected stations in the annulus between the positioner and compressor casing. The positioner can be actuated to (a) selectively move the probe along its own axis, (b) adjust the yaw angle of the right-angled probe tip, and (c) revolve the probe about the axis common to the positioner and casing. A cam plate engages a cam-follower portion of the probe and normally rotates with the positioner. The positioner includes a first-motor-driven ring gear which effects slidable movement of the probe by rotating the positioner at a time when an external pneumatic cylinder is actuated to engage the cam plate and hold it stationary. When the pneumatic cylinder is not actuated, this ring gear can be driven to revolve the positioner and thus the probe to a desired circumferential location about the above-mentioned common axis. A second motor-driven ring gear included in the positioner can be driven to rotate the probe about its axis, thus adjusting the yaw angle of the probe tip. The positioner can be used in highly corrosive atmosphere, such as gaseous uranium hexafluoride. 10 claims, 6 figures

  19. An Ultrasonographic Periodontal Probe

    Science.gov (United States)

    Bertoncini, C. A.; Hinders, M. K.

    2010-02-01

    Periodontal disease, commonly known as gum disease, affects millions of people. The current method of detecting periodontal pocket depth is painful, invasive, and inaccurate. As an alternative to manual probing, an ultrasonographic periodontal probe is being developed to use ultrasound echo waveforms to measure periodontal pocket depth, which is the main measure of periodontal disease. Wavelet transforms and pattern classification techniques are implemented in artificial intelligence routines that can automatically detect pocket depth. The main pattern classification technique used here, called a binary classification algorithm, compares test objects with only two possible pocket depth measurements at a time and relies on dimensionality reduction for the final determination. This method correctly identifies up to 90% of the ultrasonographic probe measurements within the manual probe's tolerance.

  20. Hard probes 2006 Asilomar

    CERN Multimedia

    2006-01-01

    "The second international conference on hard and electromagnetic probes of high-energy nuclear collisions was held June 9 to 16, 2006 at the Asilomar Conference grounds in Pacific Grove, California" (photo and 1/2 page)

  1. Model for resonant plasma probe.

    Energy Technology Data Exchange (ETDEWEB)

    Warne, Larry Kevin; Johnson, William Arthur; Hebner, Gregory Albert; Jorgenson, Roy E.; Coats, Rebecca Sue

    2007-04-01

    This report constructs simple circuit models for a hairpin shaped resonant plasma probe. Effects of the plasma sheath region surrounding the wires making up the probe are determined. Electromagnetic simulations of the probe are compared to the circuit model results. The perturbing effects of the disc cavity in which the probe operates are also found.

  2. A small dimension intraoperative probe

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    This article introduces the usage of the intraoperative probe in surgical based on RGS and proposes one method to design the probe. Also, a charge-sensitive preamplifier used in semiconductor detector was constructed which can reduce the dimension of the probe. At last the probe is tested by some animal experiments. Results showed that the property of this system are reliable.

  3. Multispectral imaging probe

    Science.gov (United States)

    Sandison, David R.; Platzbecker, Mark R.; Descour, Michael R.; Armour, David L.; Craig, Marcus J.; Richards-Kortum, Rebecca

    1999-01-01

    A multispectral imaging probe delivers a range of wavelengths of excitation light to a target and collects a range of expressed light wavelengths. The multispectral imaging probe is adapted for mobile use and use in confined spaces, and is sealed against the effects of hostile environments. The multispectral imaging probe comprises a housing that defines a sealed volume that is substantially sealed from the surrounding environment. A beam splitting device mounts within the sealed volume. Excitation light is directed to the beam splitting device, which directs the excitation light to a target. Expressed light from the target reaches the beam splitting device along a path coaxial with the path traveled by the excitation light from the beam splitting device to the target. The beam splitting device directs expressed light to a collection subsystem for delivery to a detector.

  4. A curved vitrectomy probe.

    Science.gov (United States)

    Chalam, K V; Shah, Vinay A; Tripathi, Ramesh C

    2004-01-01

    A curved vitrectomy probe for better accessibility of the peripheral retina in phakic eyes is described. The specially designed curved vitrectomy probe has a 20-gauge pneumatic cutter. The radius of curvature at the shaft is 19.4 mm and it is 25 mm long. The ora serrata is accessed through a 3.0- or 4.0-mm sclerotomy in phakic eyes without touching the crystalline lens. Use of this instrument avoids inadvertent trauma to the clear lens in phakic eyes requiring vitreous base excision. This curved vitrectomy instrument complements wide-angle viewing systems and endoscopes for safe surgical treatment of peripheral retinal pathology in phakic eyes. PMID:15185799

  5. Probing the Solar System

    Science.gov (United States)

    Wilkinson, John

    2013-01-01

    Humans have always had the vision to one day live on other planets. This vision existed even before the first person was put into orbit. Since the early space missions of putting humans into orbit around Earth, many advances have been made in space technology. We have now sent many space probes deep into the Solar system to explore the planets and…

  6. One-Probe Search

    DEFF Research Database (Denmark)

    Östlin, Anna; Pagh, Rasmus

    2002-01-01

    We consider dictionaries that perform lookups by probing a single word of memory, knowing only the size of the data structure. We describe a randomized dictionary where a lookup returns the correct answer with probability 1 - e, and otherwise returns don't know. The lookup procedure uses an expan...

  7. ATA probe beam experiment

    International Nuclear Information System (INIS)

    The philosophy of these tests is to measure the motion of a low current, small diameter electron beam in the accelerator before running high current. By using low current, we can study particle motion in the applied fields without any extra complications associated with the self-forces of high currents. With the steering magnets off, we have measured the transverse drift of the probe beam. Also, we have used the probe beam to optimize the current in the steering magnets to compensate for the drift. There have been concurrent efforts to locate the source of the error field which is presumed to cause the drift. So far, the source has not been established but the search is continuing

  8. Scanning Probe Microscopy and Spectroscopy

    Science.gov (United States)

    Wiesendanger, Roland

    1994-09-01

    Preface; List of acronyms; Introduction; Part I. Experimental Methods and Theoretical Background of Scanning Probe Microscopy and Spectroscopy: 1. Scanning tunnelling microscopy; 2. Scanning force microscopy; 3. Related scanning probe techniques; Part II. Applications of Scanning Probe Microscopy and Spectroscopy: 4. Condensed matter physics; 5. Chemistry; 6. Organic materials; 7. Metrology and standards; 8. Nanotechnology; References; Index.

  9. Ultrasonic temperature measuring probe

    International Nuclear Information System (INIS)

    The temperature measuring probe made of sensor wire and the tube encasing it is suited for being used in fuel columns at temperatures above 20000C. The thermal expansion coefficient, the linear dimensions, and the fastening points are chosen in such manner that the temperature fluctuations occuring during operation produce such relative variations in length that formation of bridges between sensor wire and encasing tube are suppressed already in the initial stage. (DG) 891 HP/DG 892 MKO

  10. Einstein Inflationary Probe (EIP)

    Science.gov (United States)

    Hinshaw, Gary

    2004-01-01

    I will discuss plans to develop a concept for the Einstein Inflation Probe: a mission to detect gravity waves from inflation via the unique signature they impart to the cosmic microwave background (CMB) polarization. A sensitive CMB polarization satellite may be the only way to probe physics at the grand-unified theory (GUT) scale, exceeding by 12 orders of magnitude the energies studied at the Large Hadron Collider. A detection of gravity waves would represent a remarkable confirmation of the inflationary paradigm and set the energy scale at which inflation occurred when the universe was a fraction of a second old. Even a strong upper limit to the gravity wave amplitude would be significant, ruling out many common models of inflation, and pointing to inflation occurring at much lower energy, if at all. Measuring gravity waves via the CMB polarization will be challenging. We will undertake a comprehensive study to identify the critical scientific requirements for the mission and their derived instrumental performance requirements. At the core of the study will be an assessment of what is scientifically and experimentally optimal within the scope and purpose of the Einstein Inflation Probe.

  11. ContainerProbe-Net

    International Nuclear Information System (INIS)

    ContainerProbe-Net is a global system concept for high throughput Risk Screening of inter-modal containers while they are in motion. It will have the following detection capabilities: 1. Mis-declared hazardous materials: - illegal waste exports or imports; - hazardous materials causing many annual maritime insurance claims; - accumulated pest poisons. 2. Contraband materials: - smuggled and counterfeit goods to avoid import duties and restrictions; - narcotic drugs; - weapons for criminals; - illegal immigrants. 3. Terrorism materials: - explosives and precursors - Weapons of Mass Destruction - fissile materials. The demand for this type of detection capability with high throughput has been declared by the EU, USA and other nations as a consequence of the rising policy of Civil Security. Efforts to advocate ContainerProbe-Net to both U.S.A. and EU security research administrators are progressing as the private investment base grows. ContainerProbe-Net directly addresses the 100% Risk Screening of containers requirement. Neutron interrogation of each container on a train or on an automated vehicle passing through the ContainerProbe portal will provide information about the bulk elemental composition of the contents. A burst of pulsed neutrons for a combination of prompt γ and secondary neutron emissions can provide a measured 'fingerprint' which will remain constant from the start to the end of the container's journey. A period of two seconds is available per container in order to capture data for each container on a moving train. Contents of containers are already, to some extent, registered in the export logistics databases. However these disparate systems have evolved with computer science and the needs of ports and customs authorities. Today such systems are far from complete. The global access to such registered container data and the fusion of this information with actual physical measurement data is the Network part of the concept. Risk screening implies

  12. Comparative evaluation of probing depth and clinical attachment level using a manual probe and Florida probe

    Directory of Open Access Journals (Sweden)

    Amandeep Kour

    2016-01-01

    Full Text Available Background: To compare and evaluate the intra- and inter-examiner efficacy and reproducibility of the first-generation manual (Williams probe and the third-generation Florida probe in terms of measuring pocket probing depth (PD and clinical attachment level (CAL. Materials and Methods: Forty subjects/4000 sites were included in this comparative, cross-sectional study. Group- and site-wise categorizations were done. Based on gingival index, PD, and CAL, patients were divided into four groups, i.e., periodontally healthy, gingivitis, mild to moderate periodontitis, and severe periodontitis. Further, based on these parameters, a total of 4000 sites, with 1000 sites in each category randomly selected from these 40 patients, were taken. Full mouth PD and CAL measurements were recorded with two probes, by Examiner 1 and on Ramfjord teeth by Examiner 2. Results: Full mouth and Ramfjord teeth group- and site-wise PD obtained with the manual probe by both the examiners were statistically significantly deeper than that obtained with the Florida probe. The full mouth and Ramfjord teeth mean CAL measurement by Florida probe was higher as compared to manual probe in mild to moderate periodontitis group and sites, whereas in severe periodontitis group and sites, manual probe recorded higher CAL as compared to Florida probe. Conclusion: Mean PD and CAL measurements were deeper with the manual probe as compared to the Florida probe in all the groups and sites, except for the mild-moderate periodontitis group and sites where the CAL measurements with the manual probe were less than the Florida probe. Manual probe was more reproducible and showed less interexaminer variability as compared to the Florida probe.

  13. Wearable probes for service design

    DEFF Research Database (Denmark)

    Mullane, Aaron; Laaksolahti, Jarmo Matti; Svanæs, Dag

    2014-01-01

    Probes are used as a design method in user-centred design to allow end-users to inform design by collecting data from their lives. Probes are potentially useful in service innovation, but current probing methods require users to interrupt their activity and are consequently not ideal for use...... by service employees in reflecting on the delivery of a service. In this paper, we present the ‘wearable probe’, a probe concept that captures sensor data without distracting service employees. Data captured by the probe can be used by the service employees to reflect and co-reflect on the service journey......, helping to identify opportunities for service evolution and innovation....

  14. Probe current, probe size, and the practical brightness for probe forming systems

    NARCIS (Netherlands)

    Bronsgeest, M.S.; Barth, J.E.; Swanson, L.W.; Kruit, P.

    2008-01-01

    Probe size, shape, and current are important parameters for the performance of all probe forming systems such as the scanning (transmission) electron microscope, the focused ion beam microscope, and the Gaussian electron beam lithography system. Currently, however, the relation between probe current

  15. Probe-based data storage

    CERN Document Server

    Koelmans, Wabe W; Abelmann, L

    2015-01-01

    Probe-based data storage attracted many researchers from academia and industry, resulting in unprecendeted high data-density demonstrations. This topical review gives a comprehensive overview of the main contributions that led to the major accomplishments in probe-based data storage. The most investigated technologies are reviewed: topographic, phase-change, magnetic, ferroelectric and atomic and molecular storage. Also, the positioning of probes and recording media, the cantilever arrays and parallel readout of the arrays of cantilevers are discussed. This overview serves two purposes. First, it provides an overview for new researchers entering the field of probe storage, as probe storage seems to be the only way to achieve data storage at atomic densities. Secondly, there is an enormous wealth of invaluable findings that can also be applied to many other fields of nanoscale research such as probe-based nanolithography, 3D nanopatterning, solid-state memory technologies and ultrafast probe microscopy.

  16. Atom Probe Tomography 2012

    Science.gov (United States)

    Kelly, Thomas F.; Larson, David J.

    2012-08-01

    In the world of tomographic imaging, atom probe tomography (APT) occupies the high-spatial-resolution end of the spectrum. It is highly complementary to electron tomography and is applicable to a wide range of materials. The current state of APT is reviewed. Emphasis is placed on applications and data analysis as they apply to many fields of research and development including metals, semiconductors, ceramics, and organic materials. We also provide a brief review of the history and the instrumentation associated with APT and an assessment of the existing challenges in the field.

  17. Atom probe tomography today

    Directory of Open Access Journals (Sweden)

    Alfred Cerezo

    2007-12-01

    Full Text Available This review aims to describe and illustrate the advances in the application of atom probe tomography that have been made possible by recent developments, particularly in specimen preparation techniques (using dual-beam focused-ion beam instruments but also of the more routine use of laser pulsing. The combination of these two developments now permits atomic-scale investigation of site-specific regions within engineering alloys (e.g. at grain boundaries and in the vicinity of cracks and also the atomic-level characterization of interfaces in multilayers, oxide films, and semiconductor materials and devices.

  18. Experimental probes of axions

    Energy Technology Data Exchange (ETDEWEB)

    Chou, Aaron S.; /Fermilab

    2009-10-01

    Experimental searches for axions or axion-like particles rely on semiclassical phenomena resulting from the postulated coupling of the axion to two photons. Sensitive probes of the extremely small coupling constant can be made by exploiting familiar, coherent electromagnetic laboratory techniques, including resonant enhancement of transitions using microwave and optical cavities, Bragg scattering, and coherent photon-axion oscillations. The axion beam may either be astrophysical in origin as in the case of dark matter axion searches and solar axion searches, or created in the laboratory from laser interactions with magnetic fields. This note is meant to be a sampling of recent experimental results.

  19. Mobile Probing Kit

    DEFF Research Database (Denmark)

    Larsen, Jakob Eg; Sørensen, Lene Tolstrup; Sørensen, J.K.;

    2007-01-01

    Mobile Probing Kit is a low tech and low cost methodology for obtaining inspiration and insights into user needs, requirements and ideas in the early phases of a system's development process. The methodology is developed to identify user needs, requirements and ideas among knowledge workers...... characterized as being highly nomadic and thus potential users of mobile and ubiquitous technologies. The methodology has been applied in the 1ST MAGNET Beyond project in order to obtain user needs and requirements in the process of developing pilot services. We report on the initial findings from applying...

  20. COORDINATE MEASURING MACHINE PROBING ACCESSIBILITY

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The accessibility of coordinate measuring machines (CMMs) in dimensional inspection is studied. The problem of computing the global accessibility cone is solved using a method of angle representation. Otherwise, the length and volume of probe are considered sufficiently so that all the feasible probe orientations could be determined for the inspection of a workpiece when a touch trigger probe is used and the shortcoming of abstracting a probe as an infinite half-line could be overcome completely. In the end, an example is given to explain the method.

  1. Cosmological Probes for Supersymmetry

    Directory of Open Access Journals (Sweden)

    Maxim Khlopov

    2015-05-01

    Full Text Available The multi-parameter character of supersymmetric dark-matter models implies the combination of their experimental studies with astrophysical and cosmological probes. The physics of the early Universe provides nontrivial effects of non-equilibrium particles and primordial cosmological structures. Primordial black holes (PBHs are a profound signature of such structures that may arise as a cosmological consequence of supersymmetric (SUSY models. SUSY-based mechanisms of baryosynthesis can lead to the possibility of antimatter domains in a baryon asymmetric Universe. In the context of cosmoparticle physics, which studies the fundamental relationship of the micro- and macro-worlds, the development of SUSY illustrates the main principles of this approach, as the physical basis of the modern cosmology provides cross-disciplinary tests in physical and astronomical studies.

  2. Supernovae as cosmological probes

    CERN Document Server

    Nielsen, Jeppe Trost

    2015-01-01

    The cosmological standard model at present is widely accepted as containing mainly things we do not understand. In particular the appearance of a Cosmological Constant, or dark energy, is puzzling. This was first inferred from the Hubble diagram of a low number of Type Ia supernovae, and later corroborated by complementary cosmological probes. Today, a much larger collection of supernovae is available, and here I perform a rigorous statistical analysis of this dataset. Taking into account how the supernovae are calibrated to be standard candles, we run into some subtleties in the analysis. To our surprise, this new dataset - about an order of bigger than the size of the original dataset - shows, under standard assumptions, only mild evidence of an accelerated universe.

  3. Cosmological Probes for Supersymmetry

    CERN Document Server

    Khlopov, Maxim

    2015-01-01

    The multi-parameter character of supersymmetric dark-matter models implies the combination of their experimental studies with astrophysical and cosmological probes. The physics of the early Universe provides nontrivial effects of non-equilibrium particles and primordial cosmological structures. Primordial black holes (PBHs) are a profound signature of such structures that may arise as a cosmological consequence of supersymmetric (SUSY) models. SUSY-based mechanisms of baryosynthesis can lead to the possibility of antimatter domains in a baryon asymmetric Universe. In the context of cosmoparticle physics, which studies the fundamental relationship of the micro- and macro-worlds, the development of SUSY illustrates the main principles of this approach, as the physical basis of the modern cosmology provides cross-disciplinary tests in physical and astronomical studies.

  4. New probe of naturalness.

    Science.gov (United States)

    Craig, Nathaniel; Englert, Christoph; McCullough, Matthew

    2013-09-20

    Any new scalar fields that perturbatively solve the hierarchy problem by stabilizing the Higgs boson mass also generate new contributions to the Higgs boson field-strength renormalization, irrespective of their gauge representation. These new contributions are physical, and in explicit models their magnitude can be inferred from the requirement of quadratic divergence cancellation; hence, they are directly related to the resolution of the hierarchy problem. Upon canonically normalizing the Higgs field, these new contributions lead to modifications of Higgs couplings that are typically great enough that the hierarchy problem and the concept of electroweak naturalness can be probed thoroughly within a precision Higgs boson program. Specifically, at a lepton collider this can be achieved through precision measurements of the Higgs boson associated production cross section. This would lead to indirect constraints on perturbative solutions to the hierarchy problem in the broadest sense, even if the relevant new fields are gauge singlets.

  5. Micro scanning probes

    CERN Document Server

    Niblock, T

    2001-01-01

    This thesis covers the design methodology, theory, modelling, fabrication and evaluation of a Micro-Scanning-Probe. The device is a thermally actuated bimorph quadrapod fabricated using Micro Electro Mechanical Systems technology. A quadrapod is a structure with four arms, in this case a planar structure with the four arms forming a cross which is dry etched out of a silicon diaphragm. Each arm has a layer of aluminium deposited on it forming a bimorph. Through heating each arm actuation is achieved in the plane of the quadrapod and the direction normal to it. Fabrication of the device has required the development of bulk micromachining techniques to handle post CMOS fabricated wafers and the patterning of thickly sputtered aluminium in bulk micro machined cavities. CMOS fabrication techniques were used to incorporate diodes onto the quadrapod arms for temperature measurement of the arms. Fine tungsten and silicon tips have also been fabricated to allow tunnelling between the tip and the platform at the centr...

  6. Comparative evaluation of probing depth and clinical attachment level using a manual probe and Florida probe

    OpenAIRE

    Amandeep Kour; Ashish Kumar; Komal Puri; Manish Khatri; Mansi Bansal; Geeti Gupta

    2016-01-01

    Background: To compare and evaluate the intra- and inter-examiner efficacy and reproducibility of the first-generation manual (Williams) probe and the third-generation Florida probe in terms of measuring pocket probing depth (PD) and clinical attachment level (CAL). Materials and Methods: Forty subjects/4000 sites were included in this comparative, cross-sectional study. Group- and site-wise categorizations were done. Based on gingival index, PD, and CAL, patients were divided into four group...

  7. Non-inductive current probe

    DEFF Research Database (Denmark)

    Bak, Christen Kjeldahl

    1977-01-01

    The current probe described is a low-cost, shunt resistor for monitoring current pulses in e.g., pulsed lasers. Rise time is......The current probe described is a low-cost, shunt resistor for monitoring current pulses in e.g., pulsed lasers. Rise time is...

  8. Electrophoresis-mass spectrometry probe

    Science.gov (United States)

    Andresen, Brian D.; Fought, Eric R.

    1987-01-01

    The invention involves a new technique for the separation of complex mixtures of chemicals, which utilizes a unique interface probe for conventional mass spectrometers which allows the electrophoretically separated compounds to be analyzed in real-time by a mass spectrometer. This new chemical analysis interface, which couples electrophoresis with mass spectrometry, allows complex mixtures to be analyzed very rapidly, with much greater specificity, and with greater sensitivity. The interface or probe provides a means whereby large and/or polar molecules in complex mixtures to be completely characterized. The preferred embodiment of the probe utilizes a double capillary tip which allows the probe tip to be continually wetted by the buffer, which provides for increased heat dissipation, and results in a continually operating interface which is more durable and electronically stable than the illustrated single capillary tip probe interface.

  9. Rotating concave eddy current probe

    Science.gov (United States)

    Roach, Dennis P.; Walkington, Phil; Rackow, Kirk A.; Hohman, Ed

    2008-04-01

    A rotating concave eddy current probe for detecting fatigue cracks hidden from view underneath the head of a raised head fastener, such as a buttonhead-type rivet, used to join together structural skins, such as aluminum aircraft skins. The probe has a recessed concave dimple in its bottom surface that closely conforms to the shape of the raised head. The concave dimple holds the probe in good alignment on top of the rivet while the probe is rotated around the rivet's centerline. One or more magnetic coils are rigidly embedded within the probe's cylindrical body, which is made of a non-conducting material. This design overcomes the inspection impediment associated with widely varying conductivity in fastened joints.

  10. Mobile Probes in Mobile Learning

    DEFF Research Database (Denmark)

    Ørngreen, Rikke; Blomhøj, Ulla; Duvaa, Uffe

    as an agent for acquiring empirical data (as the situation in hitherto mobile probe settings) but was also the technological medium for which data should say something about (mobile learning). Consequently, not only the content of the data but also the ways in which data was delivered and handled, provided......In this paper experiences from using mobile probes in educational design of a mobile learning application is presented. The probing process stems from the cultural probe method, and was influenced by qualitative interview and inquiry approaches. In the project, the mobile phone was not only acting...... a valuable dimension for investigating mobile use. The data was collected at the same time as design activities took place and the collective data was analysed based on user experience goals and cognitive processes from interaction design and mobile learning. The mobile probe increased the knowledge base...

  11. Exact probes of orientifolds

    CERN Document Server

    Fiol, Bartomeu; Torrents, Genis

    2014-01-01

    We compute the exact vacuum expectation value of circular Wilson loops for Euclidean ${\\cal N}=4$ super Yang-Mills with $G=SO(N),Sp(N)$, in the fundamental and spinor representations. These field theories are dual to type IIB string theory compactified on $AdS_5\\times {\\mathbb R} {\\mathbb P}^5$ plus certain choices of discrete torsion, and we use our results to probe this holographic duality. We first revisit the LLM-type geometries having $AdS_5\\times {\\mathbb R} {\\mathbb P}^5$ as ground state. Our results clarify and refine the identification of these LLM-type geometries as bubbling geometries arising from fermions on a half harmonic oscillator. We furthermore identify the presence of discrete torsion with the one-fermion Wigner distribution becoming negative at the origin of phase space. We then turn to the string world-sheet interpretation of our results and argue that for the quantities considered they imply two features: first, the contribution coming from world-sheets with a single crosscap is closely ...

  12. The AMEMIYA probe. Theoretical background

    International Nuclear Information System (INIS)

    The present probe was developed in order to measure the temperature Ti of positive ions in the scrape-off layer (SOL) of tokamak where Ti is usually larger than the electron temperature Ti so that the presheath in front of the probe need not be considered and the ions reach the probe with the thermal velocity. The axis of the cylindrical probe is placed parallel to the magnetic field. The important parameter are L/a, the ratio of the length to the radius of the cylindrical probe and κ, the ratio of the probe radius to (π/4)1/2 , where is the mean ion Larmor radius. The ion current densities to the side and the end surfaces are expressed by the double integral, which can give an analytical formula with respect to the value of κ. If two electrodes with different lengths are placed parallel to the magnetic field, the difference of current densities can be reduced to κ and hence to Ti. Some examples of the application of the probe to tokamaks, JFT-2M and Textor, are demonstrated. (author)

  13. Small Probe Reentry System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Global Aerospace Corporation (GAC), and its research partner, Cal Poly San Luis Obispo (CPSLO), will develop an integrated Small Probe Reentry System (SPRS) for low...

  14. Lunar Probe Reaches Deep Space

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    @@ China's second lunar probe, Chang'e-2, has reached an orbit 1.5 million kilometers from Earth for an additional mission of deep space exploration, the State Administration for Science, Technology and Industry for National Defense announced.

  15. DNA probe for lactobacillus delbrueckii

    Energy Technology Data Exchange (ETDEWEB)

    Delley, M.; Mollet, B.; Hottinger, H. (Nestle Research Centre, Lausanne (Switzerland))

    1990-06-01

    From a genomic DNA library of Lactobacillus delbrueckii subsp. bulgaricus, a clone was isolated which complements a leucine auxotrophy of an Escherichia coli strain (GE891). Subsequent analysis of the clone indicated that it could serve as a specific DNA probe. Dot-blot hybridizations with over 40 different Lactobacillus strains showed that this clone specifically recognized L. delbrueckii subsp. delbrueckii, bulgaricus, and lactis. The sensitivity of the method was tested by using an {alpha}-{sup 32}P-labeled probe.

  16. Probe aids mine stability work

    International Nuclear Information System (INIS)

    A simple device for measuring the thickness of mudstone or shale in underground coal mines has been developed. The probe detects the point where shale gives way to sandstone in a bolt hole. Naturally occurring radioisotopes present in mudstone and shale emit gamma rays, and the radiation count given by the probe reveals whether the sensor is surrounded by one of those materials or by sandstone

  17. Multiple-probe scanning probe microscopes for nanoarchitectonic materials science

    Science.gov (United States)

    Nakayama, Tomonobu; Shingaya, Yoshitaka; Aono, Masakazu

    2016-11-01

    Nanoarchitectonic systems are of interest for utilizing a vast range of nanoscale materials for future applications requiring a huge number of elemental nanocomponents. To explore the science and technology of nanoarchitectonics, advanced characterization tools that can deal with both nanoscale objects and macroscopically extended nanosystems are demanded. Multiple-probe scanning probe microscopes (MP-SPMs) are powerful tools that meet this demand because they take the advantages of conventional scanning probe microscopes and realize atomically precise electrical measurements, which cannot be done with conventional microprobing systems widely used in characterizing materials and devices. Furthermore, an MP-SPM can be used to operate some nanoarchitectonic systems. In this review, we overview the indispensable features of MP-SPMs together with the past, present and future of MP-SPM technology.

  18. All-Fiber Raman Probe

    DEFF Research Database (Denmark)

    Brunetti, Anna Chiara

    The design and development of an all-in-fiber probe for Raman spectroscopy are presented in this Thesis. Raman spectroscopy is an optical technique able to probe a sample based on the inelastic scattering of monochromatic light. Due to its high specificity and reliability and to the possibility...... to perform real-time measurements with little or no sample preparation, Raman spectroscopy is now considered an invaluable analytical tool, finding application in several fields including medicine, defense and process control. When combined with fiber optics technology, Raman spectroscopy allows...... for the realization of flexible and minimally-invasive devices, able to reach remote or hardly accessible samples, and to perform in-situ analyses in hazardous environments. The work behind this Thesis focuses on the proof-of-principle demonstration of a truly in-fiber Raman probe, where all parts are realized...

  19. Sensor probe for rectal manometry

    Energy Technology Data Exchange (ETDEWEB)

    Blechschmidt, R.A.; Hohlfeld, O.; Mueller, R.; Werthschuetzky, R. [Technische Univ. Darmstadt (Germany). Inst. fuer Elektromechanische Konstruktionen

    2001-07-01

    In this paper a pressure sensor probe is presented that is suitable for assessing dynamic rectal pressure profiles. It consists of ten piezoresistive sensors, mounted on low temperature co-fired ceramics. The sensors are coated with a bio-compatible silicone elastomer. It was possible to reduce the size of the ceramic to 4.5 x 5.5 mm with a height of 1.4 mm. The whole probe has a diameter of 9 mm and a length of 20 cm. One healthy test person underwent rectal manometry. The experimental data and the analysis of linearity, hysteresis, temperature stability, and reproducibility are discussed. The presented sensor probe extends the classical anorectal manometry, particularly in view of quantifying disorders of the rectal motility. (orig.)

  20. Radioactive Probes on Ferromagnetic Surfaces

    CERN Multimedia

    2002-01-01

    On the (broad) basis of our studies of nonmagnetic radioactive probe atoms on magnetic surfaces and at interfaces, we propose to investigate the magnetic interaction of magnetic probe atoms with their immediate environment, in particular of rare earth (RE) elements positioned on and in ferromagnetic surfaces. The preparation and analysis of the structural properties of such samples will be performed in the UHV chamber HYDRA at the HMI/Berlin. For the investigations of the magnetic properties of RE atoms on surfaces Perturbed Angular Correlation (PAC) measurements and Mössbauer Spectroscopy (MS) in the UHV chamber ASPIC (Apparatus for Surface Physics and Interfaces at CERN) are proposed.

  1. Probing Interactions between Ultracold Fermions

    CERN Document Server

    Campbell, G K; Thomsen, J W; Martin, M J; Blatt, S; Swallows, M D; Nicholson, T L; Fortier, T; Oates, C W; Diddams, S A; Lemke, N D; Naidon, P; Julienne, P; Ye, Jun; Ludlow, A D

    2009-01-01

    At ultracold temperatures, the Pauli exclusion principle suppresses collisions between identical fermions. This has motivated the development of atomic clocks using fermionic isotopes. However, by probing an optical clock transition with thousands of lattice-confined, ultracold fermionic Sr atoms, we have observed density-dependent collisional frequency shifts. These collision effects have been measured systematically and are supported by a theoretical description attributing them to inhomogeneities in the probe excitation process that render the atoms distinguishable. This work has also yielded insights for zeroing the clock density shift.

  2. Probe Project Status and Accomplishments

    Energy Technology Data Exchange (ETDEWEB)

    Burris, RD

    2001-05-07

    The Probe project has completed its first full year of operation. In this document we will describe the status of the project as of December 31, 2000. We will describe the equipment configuration, then give brief descriptions of the various projects undertaken to date. We will mention first those projects performed for outside entities and then those performed for the benefit of one of the Probe sites. We will then describe projects that are under consideration, including some for which initial actions have been taken and others which are somewhat longer-term.

  3. Electroless nickel plating on optical fiber probe

    Institute of Scientific and Technical Information of China (English)

    Li Huang; Zhoufeng Wang; Zhuomin Li; Wenli Deng

    2009-01-01

    As a component of near-field scanning optical microscope (NSOM),optical fiber probe is an important factor influncing the equipment resolution.Electroless nickel plating is introduced to metallize the optical fiber probe.The optical fibers are etched by 40% HF with Turner etching method.Through pretreatment,the optical fiber probe is coated with Ni-P film by clectrolcss plating in a constant temperature water tank.Atomic absorption spectrometry (AAS),scanning electron microscopy (SEM),and energy dispersive X-ray spectrometry (EDXS) are carried out to charaeterizc the deposition on fiber probe.We have rcproducibly fabricated two kinds of fiber probes with a Ni-P fihn:aperture probe and apertureless probe.In addition,reductive particle transportation on the surface of fiber probe is proposed to explain the cause of these probes.

  4. Strange probes of the nucleus

    International Nuclear Information System (INIS)

    Recent experimental and theoretical advances in hypernuclear physics are reviewed. An appraisal is given of various suggestions for using strange probes to test partial quark deconfinement in nuclei and meson exchange vs quark-gluon exchange descriptions of baryon-baryon interactions. 76 refs., 6 figs

  5. A fluorescent probe for ecstasy.

    Science.gov (United States)

    Masseroni, D; Biavardi, E; Genovese, D; Rampazzo, E; Prodi, L; Dalcanale, E

    2015-08-18

    A nanostructure formed by the insertion in silica nanoparticles of a pyrene-derivatized cavitand, which is able to specifically recognize ecstasy in water, is presented. The absence of effects from interferents and an efficient electron transfer process occurring after complexation of ecstasy, makes this system an efficient fluorescent probe for this popular drug.

  6. Resolution analysis by random probing

    NARCIS (Netherlands)

    Fichtner, Andreas; van Leeuwen, T.

    2015-01-01

    We develop and apply methods for resolution analysis in tomography, based on stochastic probing of the Hessian or resolution operators. Key properties of our methods are (i) low algorithmic complexity and easy implementation, (ii) applicability to any tomographic technique, including full‐waveform i

  7. In-vitro accuracy and reproducibility evaluation of probing depth measurements of selected periodontal probes

    OpenAIRE

    K.N. Al Shayeb; Turner, W.; D.G. Gillam

    2013-01-01

    Aim: The purpose of the present in vitro study was to measure the accuracy and reproducibility of three periodontal probes. To eliminate environment- or examiner-related probing errors, two aluminum blocks with predrilled holes of varying depths were examined by participants who had been trained in probing before the study. This methodology improved the likelihood that any probing errors identified were generated by the probes themselves. Materials and methods: Three probes, Williams 14 W ...

  8. High pressure optical combustion probe

    Energy Technology Data Exchange (ETDEWEB)

    Woodruff, S.D.; Richards, G.A.

    1995-06-01

    The Department of Energy`s Morgantown Energy Technology Center has developed a combustion probe for monitoring flame presence and heat release. The technology involved is a compact optical detector of the OH radical`s UV fluorescence. The OH Monitor/Probe is designed to determine the flame presence and provide a qualitative signal proportional to the flame intensity. The probe can be adjusted to monitor a specific volume in the combustion zone to track spatial fluctuations in the flame. The probe is capable of nanosecond time response and is usually slowed electronically to fit the flame characteristics. The probe is a sapphire rod in a stainless steel tube which may be inserted into the combustion chamber and pointed at the flame zone. The end of the sapphire rod is retracted into the SS tube to define a narrow optical collection cone. The collection cone may be adjusted to fit the experiment. The fluorescence signal is collected by the sapphire rod and transmitted through a UV transmitting, fused silica, fiber optic to the detector assembly. The detector is a side window photomultiplier (PMT) with a 310 run line filter. A Hamamatsu photomultiplier base combined with a integral high voltage power supply permits this to be a low voltage device. Electronic connections include: a power lead from a modular DC power supply for 15 VDC; a control lead for 0-1 volts to control the high voltage level (and therefore gain); and a lead out for the actual signal. All low voltage connections make this a safe and easy to use device while still delivering the sensitivity required.

  9. Cantilevered probe detector with piezoelectric element

    Science.gov (United States)

    Adams, Jesse D.; Sulchek, Todd A.; Feigin, Stuart C.

    2012-07-10

    A disclosed chemical detection system for detecting a target material, such as an explosive material, can include a cantilevered probe, a probe heater coupled to the cantilevered probe, and a piezoelectric element disposed on the cantilevered probe. The piezoelectric element can be configured as a detector and/or an actuator. Detection can include, for example, detecting a movement of the cantilevered probe or a property of the cantilevered probe. The movement or a change in the property of the cantilevered probe can occur, for example, by adsorption of the target material, desorption of the target material, reaction of the target material and/or phase change of the target material. Examples of detectable movements and properties include temperature shifts, impedance shifts, and resonant frequency shifts of the cantilevered probe. The overall chemical detection system can be incorporated, for example, into a handheld explosive material detection system.

  10. Further capacitive imaging experiments using modified probes

    Science.gov (United States)

    Yin, Xiaokang; Li, Zhen; Yan, An; Li, Wei; Chen, Guoming; Hutchins, David A.

    2016-02-01

    In recent years, capacitive imaging (CI) is growing in popularity within the NDE communities, as it has the potential to test materials and structures for defects that are not easily tested by other techniques. In previous work, The CI technique has been successfully used on a various types of materials, including concrete, glass/carbon fibre composite, steel, etc. In such CI experiments, the probes are normally with symmetric or concentric electrodes etched onto PCBs. In addition to these conventional coplanar PCB probes, modified geometries can be made and they can lead to different applications. A brief overview of these modified probes, including high resolution surface imaging probe, combined CI/eddy current probe, and CI probe using an oscilloscope probe as the sensing electrode, is presented in this work. The potential applications brought by these probes are also discussed.

  11. Overview of Probe-based Storage Technologies

    Science.gov (United States)

    Wang, Lei; Yang, Ci Hui; Wen, Jing; Gong, Si Di; Peng, Yuan Xiu

    2016-07-01

    The current world is in the age of big data where the total amount of global digital data is growing up at an incredible rate. This indeed necessitates a drastic enhancement on the capacity of conventional data storage devices that are, however, suffering from their respective physical drawbacks. Under this circumstance, it is essential to aggressively explore and develop alternative promising mass storage devices, leading to the presence of probe-based storage devices. In this paper, the physical principles and the current status of several different probe storage devices, including thermo-mechanical probe memory, magnetic probe memory, ferroelectric probe memory, and phase-change probe memory, are reviewed in details, as well as their respective merits and weakness. This paper provides an overview of the emerging probe memories potentially for next generation storage device so as to motivate the exploration of more innovative technologies to push forward the development of the probe storage devices.

  12. Overview of Probe-based Storage Technologies.

    Science.gov (United States)

    Wang, Lei; Yang, Ci Hui; Wen, Jing; Gong, Si Di; Peng, Yuan Xiu

    2016-12-01

    The current world is in the age of big data where the total amount of global digital data is growing up at an incredible rate. This indeed necessitates a drastic enhancement on the capacity of conventional data storage devices that are, however, suffering from their respective physical drawbacks. Under this circumstance, it is essential to aggressively explore and develop alternative promising mass storage devices, leading to the presence of probe-based storage devices. In this paper, the physical principles and the current status of several different probe storage devices, including thermo-mechanical probe memory, magnetic probe memory, ferroelectric probe memory, and phase-change probe memory, are reviewed in details, as well as their respective merits and weakness. This paper provides an overview of the emerging probe memories potentially for next generation storage device so as to motivate the exploration of more innovative technologies to push forward the development of the probe storage devices. PMID:27456500

  13. Where do pulse oximeter probes break?

    Science.gov (United States)

    Crede, S; Van der Merwe, G; Hutchinson, J; Woods, D; Karlen, W; Lawn, J

    2014-06-01

    Pulse oximetry, a non-invasive method for accurate assessment of blood oxygen saturation (SPO2), is an important monitoring tool in health care facilities. However, it is often not available in many low-resource settings, due to expense, overly sophisticated design, a lack of organised procurement systems and inadequate medical device management and maintenance structures. Furthermore medical devices are often fragile and not designed to withstand the conditions of low-resource settings. In order to design a probe, better suited to the needs of health care facilities in low-resource settings this study aimed to document the site and nature of pulse oximeter probe breakages in a range of different probe designs in a low to middle income country. A retrospective review of job cards relating to the assessment and repair of damaged or faulty pulse oximeter probes was conducted at a medical device repair company based in Cape Town, South Africa, specializing in pulse oximeter probe repairs. 1,840 job cards relating to the assessment and repair of pulse oximeter probes were reviewed. 60.2 % of probes sent for assessment were finger-clip probes. For all probes, excluding the neonatal wrap probes, the most common point of failure was the probe wiring (>50 %). The neonatal wrap most commonly failed at the strap (51.5 %). The total cost for quoting on the broken pulse oximeter probes and for the subsequent repair of devices, excluding replacement components, amounted to an estimated ZAR 738,810 (USD $98,508). Improving the probe wiring would increase the life span of pulse oximeter probes. Increasing the life span of probes will make pulse oximetry more affordable and accessible. This is of high priority in low-resource settings where frequent repair or replacement of probes is unaffordable or impossible.

  14. Metalloprotein-based MRI probes.

    Science.gov (United States)

    Matsumoto, Yuri; Jasanoff, Alan

    2013-04-17

    Metalloproteins have long been recognized as key determinants of endogenous contrast in magnetic resonance imaging (MRI) of biological subjects. More recently, both natural and engineered metalloproteins have been harnessed as biotechnological tools to probe gene expression, enzyme activity, and analyte concentrations by MRI. Metalloprotein MRI probes are paramagnetic and function by analogous mechanisms to conventional gadolinium or iron oxide-based MRI contrast agents. Compared with synthetic agents, metalloproteins typically offer worse sensitivity, but the possibilities of using protein engineering and targeted gene expression approaches in conjunction with metalloprotein contrast agents are powerful and sometimes definitive strengths. This review summarizes theoretical and practical aspects of metalloprotein-based contrast agents, and discusses progress in the exploitation of these proteins for molecular imaging applications.

  15. Probing zeolites by vibrational spectroscopies.

    Science.gov (United States)

    Bordiga, Silvia; Lamberti, Carlo; Bonino, Francesca; Travert, Arnaud; Thibault-Starzyk, Frédéric

    2015-10-21

    This review addresses the most relevant aspects of vibrational spectroscopies (IR, Raman and INS) applied to zeolites and zeotype materials. Surface Brønsted and Lewis acidity and surface basicity are treated in detail. The role of probe molecules and the relevance of tuning both the proton affinity and the steric hindrance of the probe to fully understand and map the complex site population present inside microporous materials are critically discussed. A detailed description of the methods needed to precisely determine the IR absorption coefficients is given, making IR a quantitative technique. The thermodynamic parameters of the adsorption process that can be extracted from a variable-temperature IR study are described. Finally, cutting-edge space- and time-resolved experiments are reviewed. All aspects are discussed by reporting relevant examples. When available, the theoretical literature related to the reviewed experimental results is reported to support the interpretation of the vibrational spectra on an atomic level.

  16. Distance Probes of Dark Energy

    CERN Document Server

    Kim, A; Aldering, G; Allen, S; Baltay, C; Cahn, R; D'Andrea, C; Dalal, N; Dawson, K; Denney, K; Eisenstein, D; Finley, D; Freedman, W; Ho, S; Holz, D; Kent, A; Kasen, D; Kessler, R; Kuhlmann, S; Linder, E; Martini, P; Nugent, P; Perlmutter, S; Peterson, B; Riess, A; Rubin, D; Sako, M; Suntzeff, N; Suzuki, N; Thomas, R; Wood-Vasey, W M; Woosley, S

    2013-01-01

    This document presents the results from the Distances subgroup of the Cosmic Frontier Community Planning Study (Snowmass 2013). We summarize the current state of the field as well as future prospects and challenges. In addition to the established probes using Type IA supernovae and baryon acoustic oscillations, we also consider prospective methods based on clusters, active galactic nuclei, gravitational wave sirens and strong lensing time delays.

  17. Information gains from cosmological probes

    Science.gov (United States)

    Grandis, S.; Seehars, S.; Refregier, A.; Amara, A.; Nicola, A.

    2016-05-01

    In light of the growing number of cosmological observations, it is important to develop versatile tools to quantify the constraining power and consistency of cosmological probes. Originally motivated from information theory, we use the relative entropy to compute the information gained by Bayesian updates in units of bits. This measure quantifies both the improvement in precision and the `surprise', i.e. the tension arising from shifts in central values. Our starting point is a WMAP9 prior which we update with observations of the distance ladder, supernovae (SNe), baryon acoustic oscillations (BAO), and weak lensing as well as the 2015 Planck release. We consider the parameters of the flat ΛCDM concordance model and some of its extensions which include curvature and Dark Energy equation of state parameter w. We find that, relative to WMAP9 and within these model spaces, the probes that have provided the greatest gains are Planck (10 bits), followed by BAO surveys (5.1 bits) and SNe experiments (3.1 bits). The other cosmological probes, including weak lensing (1.7 bits) and {H0} measures (1.7 bits), have contributed information but at a lower level. Furthermore, we do not find any significant surprise when updating the constraints of WMAP9 with any of the other experiments, meaning that they are consistent with WMAP9. However, when we choose Planck15 as the prior, we find that, accounting for the full multi-dimensionality of the parameter space, the weak lensing measurements of CFHTLenS produce a large surprise of 4.4 bits which is statistically significant at the 8 σ level. We discuss how the relative entropy provides a versatile and robust framework to compare cosmological probes in the context of current and future surveys.

  18. Nuclear Physics with Electroweak Probes

    OpenAIRE

    Giampaolo Co'Lecce University and INFN

    2006-01-01

    The research activitities carried out in Italy during the last two years in the field of theoretical nuclear physics with electroweak probes are reviewed. Different models for electron-nucleus and neutrino-nucleus scattering are compared. The results obtained for electromagnetic reactions on few-nucleon systems and on complex nuclei are discussed. The recent developments in the study of electron- and photon-induced reactions with one and two-nucleon emission are presented.

  19. The State of Cellular Probes

    OpenAIRE

    Yim, Youngbin

    2003-01-01

    Cellular probe technology is one of several potentially promising technologies for obtaining accurate travel time information. In 1996, the Federal Communications Commission (FCC) mandated E911 requirements that cellular location be provided when 911 emergency calls come in to emergency management authorities. The E911 requirements allow 50 -300 meters from the emergency call location, depending on the type of cellular phone technology used and whether handset-based or network-based solutions...

  20. The Van Allen Probes mission

    CERN Document Server

    Burch, James

    2014-01-01

    This collection of articles provides broad and detailed information about NASA’s Van Allen Probes (formerly known as the Radiation Belt Storm Probes) twin-spacecraft Earth-orbiting mission. The mission has the objective of achieving predictive understanding of the dynamic, intense, energetic, dangerous, and presently unpredictable belts of energetic particles that are magnetically trapped in Earth’s space environment above the atmosphere. It documents the science of the radiation belts and the societal benefits of achieving predictive understanding. Detailed information is provided about the Van Allen Probes mission design, the spacecraft, the science investigations, and the onboard instrumentation that must all work together to make unprecedented measurements within a most unforgiving environment, the core of Earth’s most intense radiation regions.
 This volume is aimed at graduate students and researchers active in space science, solar-terrestrial interactions and studies of the up...

  1. Flexible Ultrasonic Phased-Array Probe

    Institute of Scientific and Technical Information of China (English)

    施克仁; 阙开良; 郭大勇

    2004-01-01

    In ultrasonic phased-array testing, most probes are rigid with fixed elements. However, when testing a cambered piece, a rigid probe cannot be used directly, but an ultrasonic chock or coupling media must be used, which adds cost and reduces the accuracy. The objective of this research was to improve the tests of cambered pieces. A flexible ultrasonic phased-array probe was developed to do the flexible phased-array testing. The key technologies in the flexible phased-array probe include the probe design and the phased-array control. A new method was developed to design the flexible probe according to the curvature of the piece and the test depth. The method includes the calculation of the element's height (he), the relative rotation angle ((e), the distance between the adjoining elements (de), and the element's effective testing range. A flexible ultrasonic phased-array probe has been developed using this method.

  2. Probing the nano-bio interface with nanoplasmonic optical probes

    Science.gov (United States)

    Yu, X.; Wu, Linxi; Khanehzar, Ali; Feizpour, Amin; Xu, Fangda; Reinhard, Björn M.

    2014-08-01

    Noble metal nanoparticles have large cross-sections in both optical and electron microscopy and plasmon coupling between noble metal nanoparticles facilitate the characterization of subdiffraction limit separations through spectral analysis of the scattered light in Plasmon Coupling Microscopy (PCM). The size compatibility of noble metal nanoparticles together with the ability to encode specific functionality in a rational fashion by control of the nanoparticle surface makes noble metal nanoparticles unique probes for a broad range of biological processes. Recent applications of the technology include i.) characterization of cellular heterogeneity in nanomaterial uptake and processing through macrophages, ii.) testing the role of viral membrane lipids in mediating viral binding and trafficking, and iii.) characterizing the spatial organization of cancer biomarkers in plasma membranes. This paper reviews some of these applications and introduces the physical and material science principles underlying them. We will also introduce the use of membrane wrapped noble metal nanoparticles, which combine the superb photophysical properties of a nanoparticle core with the biological functionality of a membrane, as probes in PCM.

  3. Soft QGP probes with ALICE

    CERN Document Server

    Graczykowski, Łukasz Kamil

    2016-01-01

    In heavy-ion collisions at the LHC a hot and dense medium of deconfided partons, the Quark-Gluon Plasma (QGP), is created. Its global properties can be characterized by the measurements of particles in the low transverse momentum (or "soft") regime, which represent the majority of created particles. In this report we outline a selection of measurements of the soft probes by the ALICE experiment in pp, p--Pb, and Pb--Pb collisions. The paper focuses on recent flow measurements via angular correlations and femtoscopic studies. The first ever preliminary analysis of $\\mathrm{K}^0_{\\rm S}\\mathrm{K}^{\\pm}$ femtoscopy is also presented.

  4. Probing Quantum Aspects of Gravity

    CERN Document Server

    Adunas, G Z; Ahluwalia, D V

    2000-01-01

    We emphasize that a specific aspect of quantum gravity is the absence of a super-selection rule that prevents a linear superposition of different gravitational charges. As an immediate consequence, we obtain a tiny, but observable, violation of the equivalence principle, provided, inertial and gravitational masses are not assumed to be operationally identical objects. In this framework, the cosmic gravitational environment affects local experiments. A range of terrestrial experiments, from neutron interferometry to neutrino oscillations, can serve as possible probes to study the emergent quantum aspects of gravity.

  5. Soil moisture calibration of TDR multilevel probes

    Directory of Open Access Journals (Sweden)

    Serrarens Daniel

    2000-01-01

    Full Text Available Time domain reflectometry (TDR probes are increasingly used for field estimation of soil water content. The objective of this study was to evaluate the accuracy of the multilevel TDR probe under field conditions. For this purpose, eight such TDR probes were installed in small plots that were seeded with beans and sorghum. Data collection from the probes was such that soil moisture readings were automated and logged using a standalone field unit. Neutron probe measurements were used to calibrate the TDR probes. Soil-probe contact and soil compaction were critical to the accuracy of the TDR, especially when a number of TDR probes are combined for a single calibration curve. If each probe is calibrated individually, approximate measurement errors were between 0.005 and 0.015 m³ m-3. However, measurement errors doubled to approximately 0.025 to 0.03 m³ m-3, when TDR probes were combined to yield a single calibration curve.

  6. Portal monitor incorporating smart probes

    International Nuclear Information System (INIS)

    Full text: Portal monitors are intended for detection of radioactive and special nuclear materials in vehicles, pedestrians, luggage, as well as for prevention of illegal traffic of radioactive sources. Monitors provide audio and visual alarms when radioactive and/or special nuclear materials are detected. They can be recommended to officers of customs, border guard and emergency services, civil defense, fire brigades, police and military departments or nuclear research or energetic facilities. The portal monitor developed by us consists in a portal frame, which sustains five intelligent probes having long plastic scintillator (0.5 liters each). The probes communicate, by serial transmission, with a Central Unit constructed around the 80552 microcontroller. This one manages the handshake, calculates the background, establishes the measuring time, starts and stops each measurement and makes all the other decisions. Sound signals and an infrared sensor drive the passing through the portal and the measuring procedure. For each measure act the result is displayed on an LCD device contaminated/uncontaminated. For the contaminated case a loud and long sound signal is also issued. An RS 232 serial interface is provided in order to further developments or custom made devices. As a result, the portal monitor detects 1 μCi 137Cs, spread all over a human body, in a 20μR/h gamma background for a measuring time of 1, 5 or 10 seconds giving a 99% confidence factor. (author)

  7. Path optimization for oil probe

    Science.gov (United States)

    Smith, O'Neil; Rahmes, Mark; Blue, Mark; Peter, Adrian

    2014-05-01

    We discuss a robust method for optimal oil probe path planning inspired by medical imaging. Horizontal wells require three-dimensional steering made possible by the rotary steerable capabilities of the system, which allows the hole to intersect multiple target shale gas zones. Horizontal "legs" can be over a mile long; the longer the exposure length, the more oil and natural gas is drained and the faster it can flow. More oil and natural gas can be produced with fewer wells and less surface disturbance. Horizontal drilling can help producers tap oil and natural gas deposits under surface areas where a vertical well cannot be drilled, such as under developed or environmentally sensitive areas. Drilling creates well paths which have multiple twists and turns to try to hit multiple accumulations from a single well location. Our algorithm can be used to augment current state of the art methods. Our goal is to obtain a 3D path with nodes describing the optimal route to the destination. This algorithm works with BIG data and saves cost in planning for probe insertion. Our solution may be able to help increase the energy extracted vs. input energy.

  8. Compact Nanowire Sensors Probe Microdroplets.

    Science.gov (United States)

    Schütt, Julian; Ibarlucea, Bergoi; Illing, Rico; Zörgiebel, Felix; Pregl, Sebastian; Nozaki, Daijiro; Weber, Walter M; Mikolajick, Thomas; Baraban, Larysa; Cuniberti, Gianaurelio

    2016-08-10

    The conjunction of miniature nanosensors and droplet-based microfluidic systems conceptually opens a new route toward sensitive, optics-less analysis of biochemical processes with high throughput, where a single device can be employed for probing of thousands of independent reactors. Here we combine droplet microfluidics with the compact silicon nanowire based field effect transistor (SiNW FET) for in-flow electrical detection of aqueous droplets one by one. We chemically probe the content of numerous (∼10(4)) droplets as independent events and resolve the pH values and ionic strengths of the encapsulated solution, resulting in a change of the source-drain current ISD through the nanowires. Further, we discuss the specificities of emulsion sensing using ion sensitive FETs and study the effect of droplet sizes with respect to the sensor area, as well as its role on the ability to sense the interior of the aqueous reservoir. Finally, we demonstrate the capability of the novel droplets based nanowire platform for bioassay applications and carry out a glucose oxidase (GOx) enzymatic test for glucose detection, providing also the reference readout with an integrated parallel optical detector. PMID:27417510

  9. Compact Nanowire Sensors Probe Microdroplets.

    Science.gov (United States)

    Schütt, Julian; Ibarlucea, Bergoi; Illing, Rico; Zörgiebel, Felix; Pregl, Sebastian; Nozaki, Daijiro; Weber, Walter M; Mikolajick, Thomas; Baraban, Larysa; Cuniberti, Gianaurelio

    2016-08-10

    The conjunction of miniature nanosensors and droplet-based microfluidic systems conceptually opens a new route toward sensitive, optics-less analysis of biochemical processes with high throughput, where a single device can be employed for probing of thousands of independent reactors. Here we combine droplet microfluidics with the compact silicon nanowire based field effect transistor (SiNW FET) for in-flow electrical detection of aqueous droplets one by one. We chemically probe the content of numerous (∼10(4)) droplets as independent events and resolve the pH values and ionic strengths of the encapsulated solution, resulting in a change of the source-drain current ISD through the nanowires. Further, we discuss the specificities of emulsion sensing using ion sensitive FETs and study the effect of droplet sizes with respect to the sensor area, as well as its role on the ability to sense the interior of the aqueous reservoir. Finally, we demonstrate the capability of the novel droplets based nanowire platform for bioassay applications and carry out a glucose oxidase (GOx) enzymatic test for glucose detection, providing also the reference readout with an integrated parallel optical detector.

  10. Twin probes for space geodesy

    International Nuclear Information System (INIS)

    The twin probe method, proposed by Bertotti and Colombo (1972) to get rid of nongravitational forces in interplanetary space, can be applied to a near-Earth orbit to eliminate the atmospheric drag. Two equal pairs of probes, each pair consisting of two passive, small and dense spheres of equal surface and different masses, are flown on a circular orbit at an altitude of about 300 km. Each pair determines the motion of an ideal point which feels only the gravitational forces. They are separated by a distance d of (100/200) km and are tracked from a spacecraft or the Space Shuttle, flying at the same altitude. The relative motion of the two ideal points is reconstructed and yields a measurement of the fine structure of the Earth gravitational field, corresponding to a harmonic order l approximately a/d (a is the radius of the Earth). The tracking can be done by laser ranging to the four spheres, covered by corner reflectors; Doppler ranging is more convenient for higher values of l and can also be used. The accuracy in the compensation of the non-gravitational forces and in the measurements one needs for a given l are discussed in detail. (author)

  11. Synthetic Fluorescent Probes for Monovalent Copper

    OpenAIRE

    Fahrni, Christoph J.

    2013-01-01

    Fluorescent probes are powerful and cost-effective tools for the detection of metal ions in biological systems. Compared to non-redox-active metal ions, the design of fluorescent probes for biological copper is challenging. Within the reducing cellular environment, copper is predominantly present in its monovalent oxidation state; therefore, the design of fluorescent probes for biological copper must take into account the rich redox and coordination chemistry of Cu(I). Recent progress in unde...

  12. NeuroMEMS: Neural Probe Microtechnologies

    Directory of Open Access Journals (Sweden)

    Sam Musallam

    2008-10-01

    Full Text Available Neural probe technologies have already had a significant positive effect on our understanding of the brain by revealing the functioning of networks of biological neurons. Probes are implanted in different areas of the brain to record and/or stimulate specific sites in the brain. Neural probes are currently used in many clinical settings for diagnosis of brain diseases such as seizers, epilepsy, migraine, Alzheimer’s, and dementia. We find these devices assisting paralyzed patients by allowing them to operate computers or robots using their neural activity. In recent years, probe technologies were assisted by rapid advancements in microfabrication and microelectronic technologies and thus are enabling highly functional and robust neural probes which are opening new and exciting avenues in neural sciences and brain machine interfaces. With a wide variety of probes that have been designed, fabricated, and tested to date, this review aims to provide an overview of the advances and recent progress in the microfabrication techniques of neural probes. In addition, we aim to highlight the challenges faced in developing and implementing ultralong multi-site recording probes that are needed to monitor neural activity from deeper regions in the brain. Finally, we review techniques that can improve the biocompatibility of the neural probes to minimize the immune response and encourage neural growth around the electrodes for long term implantation studies.

  13. Outer planet probe cost estimates: First impressions

    Science.gov (United States)

    Niehoff, J.

    1974-01-01

    An examination was made of early estimates of outer planetary atmospheric probe cost by comparing the estimates with past planetary projects. Of particular interest is identification of project elements which are likely cost drivers for future probe missions. Data are divided into two parts: first, the description of a cost model developed by SAI for the Planetary Programs Office of NASA, and second, use of this model and its data base to evaluate estimates of probe costs. Several observations are offered in conclusion regarding the credibility of current estimates and specific areas of the outer planet probe concept most vulnerable to cost escalation.

  14. Gravity Probe B orbit determination

    Science.gov (United States)

    Shestople, P.; Ndili, A.; Hanuschak, G.; Parkinson, B. W.; Small, H.

    2015-11-01

    The Gravity Probe B (GP-B) satellite was equipped with a pair of redundant Global Positioning System (GPS) receivers used to provide navigation solutions for real-time and post-processed orbit determination (OD), as well as to establish the relation between vehicle time and coordinated universal time. The receivers performed better than the real-time position requirement of 100 m rms per axis. Post-processed solutions indicated an rms position error of 2.5 m and an rms velocity error of 2.2 mm s-1. Satellite laser ranging measurements provided independent verification of the GPS-derived GP-B orbit. We discuss the modifications and performance of the Trimble Advance Navigation System Vector III GPS receivers. We describe the GP-B precision orbit and detail the OD methodology, including ephemeris errors and the laser ranging measurements.

  15. Probing Inflation with CMB Polarization

    CERN Document Server

    Baumann, Daniel; Adshead, Peter; Amblard, Alexandre; Ashoorioon, Amjad; Bartolo, Nicola; Bean, Rachel; Beltran, Maria; de Bernardis, Francesco; Bird, Simeon; Chen, Xingang; Chung, Daniel J H; Colombo, Loris; Cooray, Asantha; Creminelli, Paolo; Dodelson, Scott; Dunkley, Joanna; Dvorkin, Cora; Easther, Richard; Finelli, Fabio; Flauger, Raphael; Hertzberg, Mark P; Jones-Smith, Katherine; Kachru, Shamit; Kadota, Kenji; Khoury, Justin; Kinney, William H; Komatsu, Eiichiro; Krauss, Lawrence M; Lesgourgues, Julien; Liddle, Andrew; Liguori, Michele; Lim, Eugene; Linde, Andrei; Matarrese, Sabino; Mathur, Harsh; McAllister, Liam; Melchiorri, Alessandro; Nicolis, Alberto; Pagano, Luca; Peiris, Hiranya V; Peloso, Marco; Pogosian, Levon; Pierpaoli, Elena; Riotto, Antonio; Seljak, Uros; Senatore, Leonardo; Shandera, Sarah; Silverstein, Eva; Smith, Tristan; Vaudrevange, Pascal; Verde, Licia; Wandelt, Ben; Wands, David; Watson, Scott; Wyman, Mark; Yadav, Amit; Valkenburg, Wessel; Zaldarriaga, Matias

    2009-01-01

    We summarize the utility of precise cosmic microwave background (CMB) polarization measurements as probes of the physics of inflation. We focus on the prospects for using CMB measurements to differentiate various inflationary mechanisms. In particular, a detection of primordial B-mode polarization would demonstrate that inflation occurred at a very high energy scale, and that the inflaton traversed a super-Planckian distance in field space. We explain how such a detection or constraint would illuminate aspects of physics at the Planck scale. Moreover, CMB measurements can constrain the scale-dependence and non-Gaussianity of the primordial fluctuations and limit the possibility of a significant isocurvature contribution. Each such limit provides crucial information on the underlying inflationary dynamics. Finally, we quantify these considerations by presenting forecasts for the sensitivities of a future satellite experiment to the inflationary parameters.

  16. New Fluorescence Probes for Biomolecules

    Directory of Open Access Journals (Sweden)

    Katarzyna Jurek

    2015-07-01

    Full Text Available Steady state fluorescence measurements have been used for the investigation of interaction between the bovine serum albumin (BSA and fluorescence probes: 3-hydroxy-2,4- bis[(3-methyl-1,3-benzoxazol-2(3H-ylidenemethyl]cyclobut-2-en-1-one (SQ6, 3-hydroxy- 2,4-bis[(3-methyl-1,3-benzothiazol-2(3H-ylidenemethyl]cyclobut-2-en-1-one (SQ7 and 3-hydroxy-2,4-bis[(1,3,3-trimethyl-1,3-dihydro-2H-indol-2-ylidenemethyl]cyclobut-2-en-1-one (SQ8. The binding constant between bovine serum albumin and squarine dyes has been determined by using both the Benesi-Hildebrand and Stern-Volmer equations. The negative value of free energy change indicates the existence of a spontaneous complexation process of BSA with squarine dyes.

  17. Probing the Frontiers of QCD

    CERN Document Server

    Horowitz, W A

    2010-01-01

    With the energy scales opened up by RHIC and LHC the age of high-pT physics is upon us. This has created new opportunities and novel mysteries, both of which will be explored in this thesis. The possibility now exists experimentally to exploit these high momentum particles to uniquely probe the unprecedented state of matter produced in heavy ion collisions. At the same time naive theoretical expectations have been dashed by data. The first puzzle we confront is that of the enormous intermediate-pT azimuthal anisotropy, or v2, of jets observed at RHIC. The second puzzle is the surprisingly similar suppression of light mesons and nonphotonic electrons, which precludes perturbative predictions predicated on gluon bremsstrahlung radiation as the dominant energy loss channel. Near qualitative agreement results from including collisional energy loss and integrating over the fluctuating jet pathlengths. Another conjecture for heavy quark energy loss comes via explicit construction using the AdS/CFT correspondence; t...

  18. Gravity Probe B spacecraft description

    Science.gov (United States)

    Bennett, Norman R.; Burns, Kevin; Katz, Russell; Kirschenbaum, Jon; Mason, Gary; Shehata, Shawky

    2015-11-01

    The Gravity Probe B spacecraft, developed, integrated, and tested by Lockheed Missiles & Space Company and later Lockheed Martin Corporation, consisted of structures, mechanisms, command and data handling, attitude and translation control, electrical power, thermal control, flight software, and communications. When integrated with the payload elements, the integrated system became the space vehicle. Key requirements shaping the design of the spacecraft were: (1) the tight mission timeline (17 months, 9 days of on-orbit operation), (2) precise attitude and translational control, (3) thermal protection of science hardware, (4) minimizing aerodynamic, magnetic, and eddy current effects, and (5) the need to provide a robust, low risk spacecraft. The spacecraft met all mission requirements, as demonstrated by dewar lifetime meeting specification, positive power and thermal margins, precision attitude control and drag-free performance, reliable communications, and the collection of more than 97% of the available science data.

  19. Surface charge measurement using an electrostatic probe

    DEFF Research Database (Denmark)

    Crichton, George C; McAllister, Iain Wilson

    1998-01-01

    During the 1960s, the first measurements of charge on dielectric surfaces using simple electrostatic probes were reported. However it is only within the last 10 years that a proper understanding of the probe response has been developed. This situation arose as a consequence of the earlier studies...

  20. Theory of dual probes on graphene structures

    DEFF Research Database (Denmark)

    Settnes, Mikkel

    around the local probes. This necessitates a reformulation of the conventional calculation methods allowing for the description of non-periodic structures embedded within infinite samples. The two-dimensional material graphene, is a highly interesting system for multi- probe characterization as graphene...

  1. Development of a transient internal probe diagnostic

    Science.gov (United States)

    Spanjers, G. G.; Galambos, J. P.; Bohnet, M. A.; Jarboe, T. R.; Christiansen, W. H.; Wurden, G. A.; Wright, B. L.; Smith, R. J.

    1992-10-01

    The transient internal probe (TIP) diagnostic is a novel method for probing the interior of hot magnetic fusion plasmas. In the TIP scheme, a probe is fired, using a two-stage light gas gun, through a hot plasma at velocities up to 5 km/s, and makes direct, local measurements of the internal magnetic field structure. The data are relayed to the laboratory optical detection system using an incident laser that is directed through a Faraday rotator payload acting as a magneto-optic sensor. Ablative effects are avoided by minimizing the probe size, limiting the time that the probe is in the hot plasma, and encasing the probe with a diamond cladding. The degree to which the diamond probe cladding is susceptible to ablative effects will determine the plasma density and temperature regime in which the TIP diagnostic can be used. If the TIP suffers significant ablation it is an indication that the diagnostic is not usable on this hot and dense of a plasma (or that greater velocity must be imparted to the probe to further minimize the time that it is in the plasma). A quantitative experimental study of the ablation rates of diamond is planned as part of the TIP development. The integrated TIP system will be functional in 1992 and installed on the Helicity Injected Torus (HIT) [T. R. Jarboe, Fusion Tech. 15, 9 (1989)] at the University of Washington.

  2. Eddy Current Probe for Biological Structures Identification

    International Nuclear Information System (INIS)

    The new eddy current probe for conductivity measurement of biological structures was presented. The probe operation principle is based on the differential pick-up. After theoretical analysis results of experiments have been presented. For experiments fruits and meat, have been used. (author)

  3. Inspecting Friction Stir Welding using Electromagnetic Probes

    Science.gov (United States)

    Kinchen, David G.

    2004-01-01

    A report describes the use of advanced electromagnetic probes to measure the dimensions, the spatial distribution of electrical conductivity, and related other properties of friction stir welds (FSWs) between parts made of the same or different aluminum alloy(s). The probes are of the type described in in another Tech Brief. To recapitulate: A probe of this type is essentially an eddy-current probe that includes a primary (driver) winding that meanders and multiple secondary (sensing) windings that meander along the primary winding. Electrical conductivity is commonly used as a measure of heat treatment and tempering of aluminum alloys, but prior to the development of these probes, the inadequate sensitivity and limited accuracy of electrical-conductivity probes precluded such use on FSWs between different aluminum alloys, and the resolution of those probes was inadequate for measurement of FSW dimensions with positions and metallurgical properties. In contrast, the present probes afford adequate accuracy and spatial resolution for the purposes of measuring the dimensions of FSW welds and correlating spatially varying electrical conductivities with metallurgical properties, including surface defects.

  4. Nanobits - exchangable and customisable scanning probe tips

    DEFF Research Database (Denmark)

    Yildiz, Izzet

    Invention of atomic force microscopy (AFM) pioneered a novel aspect for the surface metrology concept. A range of scanning probe methods have been developed over the years based on different sorts of tip-surface interaction: electrical, optical, thermal, force. Reproducible and fast fabrication...... replacement could greatly increase the efficiency and adaptability of a CD system. In this PhD study, NanoBits – nano-sized customisable and exchangeable scanning probe tips – were developed to meet the demands of current AFM applications. Two different methods were followed for the fabrication of Nano...... of microcantilevers and probes together with alternative probing modes ease AFM’s adaptation to altering technological needs. The need to constantly adapt to the ever-altering device architecture and perpetual size shrinkage calls for enhancements to address specific needs, like specialised probes. Device...

  5. Arrays of nucleic acid probes on biological chips

    Science.gov (United States)

    Chee, Mark; Cronin, Maureen T.; Fodor, Stephen P. A.; Huang, Xiaohua X.; Hubbell, Earl A.; Lipshutz, Robert J.; Lobban, Peter E.; Morris, MacDonald S.; Sheldon, Edward L.

    1998-11-17

    DNA chips containing arrays of oligonucleotide probes can be used to determine whether a target nucleic acid has a nucleotide sequence identical to or different from a specific reference sequence. The array of probes comprises probes exactly complementary to the reference sequence, as well as probes that differ by one or more bases from the exactly complementary probes.

  6. Imaging probe for tumor malignancy

    Science.gov (United States)

    Tanaka, Shotaro; Kizaka-Kondoh, Shinae; Hiraoka, Hasahiro

    2009-02-01

    Solid tumors possess unique microenvironments that are exposed to chronic hypoxic conditions ("tumor hypoxia"). Although more than half a century has passed since it was suggested that tumor hypoxia correlated with poor treatment outcomes and contributed to cancer recurrence, a fundamental solution to this problem has yet to be found. Hypoxia-inducible factor (HIF-1) is the main transcription factor that regulates the cellular response to hypoxia. It induces various genes whose functions are strongly associated with malignant alteration of the entire tumor. The cellular changes induced by HIF-1 are extremely important targets of cancer therapy, particularly in therapy against refractory cancers. Imaging of the HIF-1-active microenvironment is therefore important for cancer therapy. To image HIF-1activity in vivo, we developed a PTD-ODD fusion protein, POHA, which was uniquely labeled with near-infrared fluorescent dye at the C-terminal. POHA has two functional domains: protein transduction domain (PTD) and VHL-mediated protein destruction motif in oxygen-dependent degradation (ODD) domain of the alpha subunit of HIF-1 (HIF-1α). It can therefore be delivered to the entire body and remain stabilized in the HIF-1-active cells. When it was intravenously injected into tumor-bearing mice, a tumor-specific fluorescence signal was detected in the tumor 6 h after the injection. These results suggest that POHA can be used an imaging probe for tumor malignancy.

  7. Probing a Gravitational Cat State

    CERN Document Server

    Anastopoulos, Charis

    2015-01-01

    We investigate the nature of a gravitational two-state system (G2S) in the simplest setup in Newtonian gravity. In a quantum description of matter a single motionless massive particle can in principle be in a superposition state of two spatially-separated locations. This superposition state in gravity, or gravitational cat state, would lead to fluctuations in the Newtonian force exerted on a nearby test particle. The central quantity of importance for this inquiry is the energy density correlation. This corresponds to the noise kernel in stochastic gravity theory, evaluated in the weak field nonrelativistic limit. In this limit, quantum fluctuations of the stress energy tensor manifest as the fluctuations of the Newtonian force. We describe the properties of such a G2S system and present two ways of measuring the cat state for the Newtonian force, one by way of a classical probe, the other a quantum harmonic oscillator. Our findings include: (i) mass density fluctuations persist even in single particle system...

  8. Gravity Probe B Gyroscope Rotor

    Science.gov (United States)

    2003-01-01

    The Gravity Probe B (GP-B) is the relativity experiment developed at Stanford University to test two extraordinary predictions of Albert Einstein's general theory of relativity. The experiment will measure, very precisely, the expected tiny changes in the direction of the spin axes of four gyroscopes contained in an Earth-orbiting satellite at a 400-mile altitude. So free are the gyroscopes from disturbance that they will provide an almost perfect space-time reference system. They will measure how space and time are very slightly warped by the presence of the Earth, and, more profoundly, how the Earth's rotation very slightly drags space-time around with it. These effects, though small for the Earth, have far-reaching implications for the nature of matter and the structure of the Universe. This photograph is a close up of a niobium-coated gyroscope motor and its housing halves. GP-B is among the most thoroughly researched programs ever undertaken by NASA. This is the story of a scientific quest in which physicists and engineers have collaborated closely over many years. Inspired by their quest, they have invented a whole range of technologies that are already enlivening other branches of science and engineering. Launched April 20, 2004 , the GP-B program was managed for NASA by the Marshall Space Flight Center. Development of the GP-B is the responsibility of Stanford University along with major subcontractor Lockheed Martin Corporation. (Image credit to Don Harley.)

  9. Sharp Hypervelocity Aerodynamic Research Probe

    Science.gov (United States)

    Bull, Jeffrey; Kolodziej, Paul; Rasky, Daniel J. (Technical Monitor)

    1996-01-01

    The objective of this flight demonstration is to deploy a slender-body hypervelocity aerodynamic research probe (SHARP) from an orbiting platform using a tether, deorbit and fly it along its aerothermal performance constraint, and recover it intact in mid-air. To accomplish this objective, two flight demonstrations are proposed. The first flight uses a blunt-body, tethered reentry experiment vehicle (TREV) to prove out tethered deployment technology for accurate entries, a complete SHARP electronics suite, and a new soft mid-air helicopter recovery technique. The second flight takes advantage of this launch and recovery capability to demonstrate revolutionary sharp body concepts for hypervelocity vehicles, enabled by new Ultra-High Temperature Ceramics (UHTCs) recently developed by Ames Research Center. Successful demonstration of sharp body hypersonic vehicle technologies could have radical impact on space flight capabilities, including: enabling global reentry cross range capability from Station, eliminating reentry communications blackout, and allowing new highly efficient launch systems incorporating air breathing propulsion and zeroth staging.

  10. Probing Light Stops with Stoponium

    CERN Document Server

    Batell, Brian

    2015-01-01

    We derive new limits on light stops from diboson resonance searches in the $\\gamma\\gamma$, $Z \\gamma$, $ZZ$, $WW$ and $hh$ channels from the first run of the LHC. If the two-body decays of the light stop are mildly suppressed or kinematically forbidden, stoponium bound states will form in $pp$ collisions and subsequently decay via the pair annihilation of the constituent stops to diboson final states, yielding striking resonance signatures. Remarkably, we find that stoponium searches are highly complementary to direct collider searches and indirect probes of light stops such as Higgs coupling measurements. Using an empirical quarkonia potential model and including the first two $S$-wave stoponium states, we find that in the decoupling limit $m_{\\widetilde t_1} \\lesssim 130$ GeV is excluded for any value of the stop mixing angle and heavy stop mass by the combination of the latest resonance searches and the indirect constraints. The $\\gamma \\gamma$ searches are the most complementary to the indirect constraint...

  11. Hyperpolarized NMR Probes for Biological Assays

    Directory of Open Access Journals (Sweden)

    Sebastian Meier

    2014-01-01

    Full Text Available During the last decade, the development of nuclear spin polarization enhanced (hyperpolarized molecular probes has opened up new opportunities for studying the inner workings of living cells in real time. The hyperpolarized probes are produced ex situ, introduced into biological systems and detected with high sensitivity and contrast against background signals using high resolution NMR spectroscopy. A variety of natural, derivatized and designed hyperpolarized probes has emerged for diverse biological studies including assays of intracellular reaction progression, pathway kinetics, probe uptake and export, pH, redox state, reactive oxygen species, ion concentrations, drug efficacy or oncogenic signaling. These probes are readily used directly under natural conditions in biofluids and are often directly developed and optimized for cellular assays, thus leaving little doubt about their specificity and utility under biologically relevant conditions. Hyperpolarized molecular probes for biological NMR spectroscopy enable the unbiased detection of complex processes by virtue of the high spectral resolution, structural specificity and quantifiability of NMR signals. Here, we provide a survey of strategies used for the selection, design and use of hyperpolarized NMR probes in biological assays, and describe current limitations and developments.

  12. Comparative analyses of plasma probe diagnostics techniques

    International Nuclear Information System (INIS)

    The subject of this paper is a comparative analysis of the plasma parameters inferred from the classical Langmuir probe procedure, from different theories of the ion current to the probe, and from measured electron energy distribution function (EEDF) obtained by double differentiation of the probe characteristic. We concluded that the plasma parameters inferred from the classical Langmuir procedure can be subjected to significant inaccuracy due to the non-Maxwellian EEDF, uncertainty of locating the plasma potential, and the arbitrariness of the ion current approximation. The plasma densities derived from the ion part of the probe characteristics diverge by as much as an order of magnitude from the density calculated according to Langmuir procedure or calculated as corresponding integral of the measured EEDF. The electron temperature extracted from the ion part is always subjected to uncertainty. Such inaccuracy is attributed to modification of the EEDF for fast electrons due to inelastic electron collisions, and to deficiencies in the existing ion current theories; i.e., unrealistic assumptions about Maxwellian EEDFs, underestimation of the ion collisions and the ion ambipolar drift, and discounting deformation of the one-dimensional structure of the region perturbed by the probe. We concluded that EEDF measurement is the single reliable probe diagnostics for the basic research and industrial applications of highly non-equilibrium gas discharge plasmas. Examples of EEDF measurements point up importance of examining the probe current derivatives in real time and reiterate significance of the equipment technical characteristics, such as high energy resolution and wide dynamic range

  13. Gene cloning based on long oligonucleotide probes

    International Nuclear Information System (INIS)

    The most commonly used technique for gene cloning has been to utilize oligonucleotide probe based on protein sequence data. Of course this approach requires characterized and purified protein so that at least a portion of amino acid sequence can be determined and used to infer the corresponding DNA sequence. Based on the amino acid sequence information, either short or long oligonucleotide probes can be synthesized chemically. Long probes are typically 30-100 nucleotides long and are a single sequence based on a best guess for each codon. The long probe approach was first used to screen for three different genes: bovine trypsin inhibitor, human insulin-like growth factor I, and human factor IX. There are three advantages of long probes. (1) Any stretch of amino acid sequence 10 or longer can be used. (2) The amino acid sequence need not be absolutely correct. (3) These probes can be used to screen high-complexity libraries with fewer false positives. In spite of the uncertainties over codon selection, the long probe approach is currently the method of choice in screening for genes based on protein sequence data

  14. Comparative analyses of plasma probe diagnostics techniques

    Energy Technology Data Exchange (ETDEWEB)

    Godyak, V. A. [Electrical Engineering and Computer Science Department, University of Michigan, Ann Arbor, Michigan 48109, USA and RF Plasma Consulting, Brookline, Massachusetts 02446 (United States); Alexandrovich, B. M. [Plasma Sensors, Brookline, Massachusetts 02446 (United States)

    2015-12-21

    The subject of this paper is a comparative analysis of the plasma parameters inferred from the classical Langmuir probe procedure, from different theories of the ion current to the probe, and from measured electron energy distribution function (EEDF) obtained by double differentiation of the probe characteristic. We concluded that the plasma parameters inferred from the classical Langmuir procedure can be subjected to significant inaccuracy due to the non-Maxwellian EEDF, uncertainty of locating the plasma potential, and the arbitrariness of the ion current approximation. The plasma densities derived from the ion part of the probe characteristics diverge by as much as an order of magnitude from the density calculated according to Langmuir procedure or calculated as corresponding integral of the measured EEDF. The electron temperature extracted from the ion part is always subjected to uncertainty. Such inaccuracy is attributed to modification of the EEDF for fast electrons due to inelastic electron collisions, and to deficiencies in the existing ion current theories; i.e., unrealistic assumptions about Maxwellian EEDFs, underestimation of the ion collisions and the ion ambipolar drift, and discounting deformation of the one-dimensional structure of the region perturbed by the probe. We concluded that EEDF measurement is the single reliable probe diagnostics for the basic research and industrial applications of highly non-equilibrium gas discharge plasmas. Examples of EEDF measurements point up importance of examining the probe current derivatives in real time and reiterate significance of the equipment technical characteristics, such as high energy resolution and wide dynamic range.

  15. Probe Project Status and Accomplishments - Year Two

    Energy Technology Data Exchange (ETDEWEB)

    Burris, R.D.

    2002-04-11

    The Probe project has established a facility for storage- and network-related research, development and testing. With sites at the Oak Ridge National Laboratory (ORNL) and the National Energy Research Scientific Computing Center (NERSC), Probe is investigating local-area or wide-area distributed storage issues ranging from data mining to optimizing retrieval operations from tape devices. Probe has completed its second full year of operation. In this document we will describe the status of the project as of December 31, 2001. This year we will structure this document by category of work, rather than by project status. We will present sections describing Scientific Discovery through Advanced Computation (SciDAC) projects, network research and research on data mining and distributed cluster analysis. Another section will describe data-transfer application development and testing and other types of hardware- and software-related testing and development activities. We will then describe the work undertaken for presentation at the SC2001 conference. The final section will summarize this year's publications. Individual projects described in this document have used some Probe resource--equipment, software, staff or funding. By describing these projects we do not imply that the work should be entirely credited to Probe, although we do assert that Probe's existence and assistance provided benefit to the work. The Probe project is funded by the Mathematical, Information, and Computer Sciences (MICS) department of the Advanced Scientific Computing Research office, Office of Science, Department of Energy.

  16. Nuclear borehole probes - theory and experiments

    International Nuclear Information System (INIS)

    The report gives a summary of the theoretical and expeimental work on borehole probes that has been performed since 1971 at The Department of Electrophysics, The Technical University of Denmark. The first part of the report concerns the use of a spectral natural gamma-ray probe (SNG-probe), which is used for measurements of the spectral distribution of the gamma-rays of the geological strata around a borehole. In general the spectrum is divided into three parts - the gamma-rays from potassium-40, from thorium-232 and daughters, and from uranium-238 and daughters. A set of curves showing the intensities of the gamm-radiation from K, Th, and U versus depth is called a SNG-log. If proper calibrated, the SNG-log gives the concentration of Th, U, and K in the formation surrounding the borehole. Initially the basis for an interpretation of SNG-logs is discussed. Then follows a description og some SNG-problems designed and built by The Department of Electrophysics, and a discussion of the calibration of SNG-probes. Some examples of SNG-logs are presented, and some general comments on the use of SNG-logs are given. The second part of the report concerns mainly the development of theoretical models for neutron-neutron probes, gamma-gamma probes, and pulsed-neutron probes. The purpose of this work has been to examine how well the models correlate with measured results and - where reasonable agreement is found - to use the models in studies of the factors that affect the probe responses in interpretation of experimental results and in probe design. (author)

  17. 21 CFR 870.2120 - Extravascular blood flow probe.

    Science.gov (United States)

    2010-04-01

    ... blood flow probe. (a) Identification. An extravascular blood flow probe is an extravascular ultrasonic or electromagnetic probe used in conjunction with a blood flowmeter to measure blood flow in...

  18. Parallel scanning probe arrays: their applications

    Directory of Open Access Journals (Sweden)

    Chang Liu

    2008-01-01

    Full Text Available Since the invention of the scanning tunneling microscope (STM1 and the atomic force microscope (AFM2, the field of scanning probe microscopy (SPM instruments has grown steadily and has had a profound influence in materials research, chemistry, biology, nanotechnology, and electronics3,4. Today, scanning probe instruments are used for metrology, characterization5, detection6, manipulation7, patterning8,9, and material modification. A wide range of scanning probe applications are available, taking advantage of various modes of tip–substrate interactions, including force, optics10,11, electrochemistry12, electromagnetics, electrostatics, thermal and mass transfer13,14, and vibration15,16.

  19. Cone penetrometer moisture probe acceptance test report

    International Nuclear Information System (INIS)

    This Acceptance Test Report (ATR) documents the results of WHC-SD-WM-ATP-146 (Prototype Cone Penetrometer Moisture Probe Acceptance Test Procedure) and WHC-SD-WM-ATP-145 (Cone Penetrometer Moisture Probe Acceptance Test Procedure). The master copy of WHC-SD-WM-ATP-145 can be found in Appendix A and the master copy of WHC-SD-WM-ATP-146 can be found in Appendix B. Also included with this report is a matrix showing design criteria of the cone penetrometer moisture probe and the verification method used (Appendix C)

  20. Hydrophobic pocket targeting probes for enteroviruses

    Science.gov (United States)

    Martikainen, Mari; Salorinne, Kirsi; Lahtinen, Tanja; Malola, Sami; Permi, Perttu; Häkkinen, Hannu; Marjomäki, Varpu

    2015-10-01

    Visualization and tracking of viruses without compromising their functionality is crucial in order to understand virus targeting to cells and tissues, and to understand the subsequent subcellular steps leading to virus uncoating and replication. Enteroviruses are important human pathogens causing a vast number of acute infections, and are also suggested to contribute to the development of chronic diseases like type I diabetes. Here, we demonstrate a novel method to target site-specifically the hydrophobic pocket of enteroviruses. A probe, a derivative of Pleconaril, was developed and conjugated to various labels that enabled the visualization of enteroviruses under light and electron microscopes. The probe mildly stabilized the virus particle by increasing the melting temperature by 1-3 degrees, and caused a delay in the uncoating of the virus in the cellular endosomes, but could not however inhibit the receptor binding, cellular entry or infectivity of the virus. The hydrophobic pocket binding moiety of the probe was shown to bind to echovirus 1 particle by STD and tr-NOESY NMR methods. Furthermore, binding to echovirus 1 and Coxsackievirus A9, and to a lesser extent to Coxsackie virus B3 was verified by using a gold nanocluster labeled probe by TEM analysis. Molecular modelling suggested that the probe fits the hydrophobic pockets of EV1 and CVA9, but not of CVB3 as expected, correlating well with the variations in the infectivity and stability of the virus particles. EV1 conjugated to the fluorescent dye labeled probe was efficiently internalized into the cells. The virus-fluorescent probe conjugate accumulated in the cytoplasmic endosomes and caused infection starting from 6 hours onwards. Remarkably, before and during the time of replication, the fluorescent probe was seen to leak from the virus-positive endosomes and thus separate from the capsid proteins that were left in the endosomes. These results suggest that, like the physiological hydrophobic content

  1. Plasma flow measurements with Mach probe

    International Nuclear Information System (INIS)

    A Mach probe is studied as a simple method to measure the plasma flow velocity (Mach number) along magnetic field lines. The probe was located behind the separator, which is movable along the field line, to avoid a recycling-like phenomenon that occurs owing to the plasma striking the separator. From the ratio of ion currents to the probe with to without the separator, the Mach number was deduced by applying a theory proposed by Chung. Even though the theory is not necessarily satisfactory for approximation of the viscosity term in fluid equations, the Mach number obtained from the Mach probe is compared fairly well with the real Mach number which was obtained from dispersion relations of the shear Alfven wave drifting along or against the plasma flow. (author)

  2. Scanning microscopic four-point conductivity probes

    DEFF Research Database (Denmark)

    Petersen, Christian Leth; Hansen, Torben Mikael; Bøggild, Peter;

    2002-01-01

    A method for fabricating microscopic four-point probes is presented. The method uses silicon-based microfabrication technology involving only two patterning steps. The last step in the fabrication process is an unmasked deposition of the conducting probe material, and it is thus possible to select...... the conducting material either for a silicon wafer or a single probe unit. Using shadow masking photolithography an electrode spacing (pitch) down to 1.1 mum was obtained, with cantilever separation down to 200 run. Characterisation measurements have shown the microscopic probes to be mechanically very flexible...... and robust. Repeated conductivity measurements on polythiophene films in the same surface area are reproduced within an accuracy of 3%. Automated nanoresolution position control allows scanning across millimetre sized areas, in order to create high spatial resolution maps of the in-plane conductivity....

  3. Illuminated curved vitrectomy probe for vitreoretinal surgery.

    Science.gov (United States)

    Chalam, K V; Gupta, Shailesh K; Agarwal, Swati

    2007-01-01

    A new self-illuminated and curved vitrectomy probe was designed for better accessibility of the peripheral retina, particularly in phakic patients. This probe has a 20-gauge pneumatic cutter. The curvature at the shaft has a 19.4-mm radius and is 25 mm long. A 2.5-cm piece of polyethylene terephthalate tubing (heat-shrink tubing) is threaded over both the probe and the 0.5-mm diameter fiberoptic light source to assemble the illuminated probe. Use of this instrument avoids inadvertent trauma to the clear lens in phakic eyes and allows the surgeon to illuminate the anterior vitreous with one hand while the other hand can be used to depress the sclera. This instrument complements wide-angle viewing for safe and quick surgical treatment of peripheral retinal pathology in phakic patients. PMID:18050823

  4. Probe microscopy: Scanning below the cell surface

    Science.gov (United States)

    Sahin, Ozgur

    2008-08-01

    Conventional atomic force microscopy probes only the surface of specimens. A related technique called scanning near-field ultrasonic holography can now image nanoparticles buried below the surfaces of cells, which could prove useful in nanotoxicology.

  5. Development of DNA probes for Candida albicans

    Energy Technology Data Exchange (ETDEWEB)

    Cheung, L.L.; Hudson, J.B.

    1988-07-01

    An attempt was made to produce DNA probes that could be used as a rapid and efficient means of detecting candidiasis (invasive Candida infection) in immunocompromised patients. Whole DNA from Candida albicans was digested with restriction endonuclease, and the resulting fragments were randomly cloned into a plasmid vector. Several recombinant plasmids were evaluated for cross-hybridization to various other Candida species, other fungal DNAs, and to nonfungal DNAs. Cross reactions were observed between the probes and different yeasts, but none with unrelated DNAs. Some recombinants were genus-specific, and two of these were applied to the analysis of C. albicans growth curves. It became evident that, although both /sup 32/P- and biotin-labelled probes could be made quite sensitive, a possible limitation in their diagnostic potential was the poor liberation of Candida DNA from cells. Thus, better methods of treatment of clinical specimens will be required before such probes will be useful in routine diagnosis.

  6. Pneumatic Proboscis Heat Flow Probe Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The heat flow probe directly answers requirements in the topic: S1.11 Lunar Science Instruments and Technology: "Geophysical Measurements: Systems, subsystems, and...

  7. China's Reconfigurable Planet Probing Robot

    Institute of Scientific and Technical Information of China (English)

    RenShufang

    2005-01-01

    Research of reconfigurable planet probing robot conducted by the Shenyang Institute of Automation of the Chinese Academy of Science (SIA-CAS) has passed appraisal of 863 Program sresearch on intelligent robots.

  8. Modulated microwave microscopy and probes used therewith

    Science.gov (United States)

    Lai, Keji; Kelly, Michael; Shen, Zhi-Xun

    2012-09-11

    A microwave microscope including a probe tip electrode vertically positionable over a sample and projecting downwardly from the end of a cantilever. A transmission line connecting the tip electrode to the electronic control system extends along the cantilever and is separated from a ground plane at the bottom of the cantilever by a dielectric layer. The probe tip may be vertically tapped near or at the sample surface at a low frequency and the microwave signal reflected from the tip/sample interaction is demodulated at the low frequency. Alternatively, a low-frequency electrical signal is also a non-linear electrical element associated with the probe tip to non-linearly interact with the applied microwave signal and the reflected non-linear microwave signal is detected at the low frequency. The non-linear element may be semiconductor junction formed near the apex of the probe tip or be an FET formed at the base of a semiconducting tip.

  9. Surface sampling concentration and reaction probe

    Science.gov (United States)

    Van Berkel, Gary J; Elnaggar, Mariam S

    2013-07-16

    A method of analyzing a chemical composition of a specimen is described. The method can include providing a probe comprising an outer capillary tube and an inner capillary tube disposed co-axially within the outer capillary tube, where the inner and outer capillary tubes define a solvent capillary and a sampling capillary in fluid communication with one another at a distal end of the probe; contacting a target site on a surface of a specimen with a solvent in fluid communication with the probe; maintaining a plug volume proximate a solvent-specimen interface, wherein the plug volume is in fluid communication with the probe; draining plug sampling fluid from the plug volume through the sampling capillary; and analyzing a chemical composition of the plug sampling fluid with an analytical instrument. A system for performing the method is also described.

  10. Sapphire Viewports for a Venus Probe Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed Phase 1 program will demonstrate that sapphire viewports are feasible for use in Venus probes. TvU's commercial viewport products have demonstrated...

  11. Development of DNA probes for Candida albicans

    International Nuclear Information System (INIS)

    An attempt was made to produce DNA probes that could be used as a rapid and efficient means of detecting candidiasis (invasive Candida infection) in immunocompromised patients. Whole DNA from Candida albicans was digested with restriction endonuclease, and the resulting fragments were randomly cloned into a plasmid vector. Several recombinant plasmids were evaluated for cross-hybridization to various other Candida species, other fungal DNAs, and to nonfungal DNAs. Cross reactions were observed between the probes and different yeasts, but none with unrelated DNAs. Some recombinants were genus-specific, and two of these were applied to the analysis of C. albicans growth curves. It became evident that, although both 32P- and biotin-labelled probes could be made quite sensitive, a possible limitation in their diagnostic potential was the poor liberation of Candida DNA from cells. Thus, better methods of treatment of clinical specimens will be required before such probes will be useful in routine diagnosis

  12. Automated design of genomic Southern blot probes

    Directory of Open Access Journals (Sweden)

    Komiyama Noboru H

    2010-01-01

    Full Text Available Abstract Background Sothern blotting is a DNA analysis technique that has found widespread application in molecular biology. It has been used for gene discovery and mapping and has diagnostic and forensic applications, including mutation detection in patient samples and DNA fingerprinting in criminal investigations. Southern blotting has been employed as the definitive method for detecting transgene integration, and successful homologous recombination in gene targeting experiments. The technique employs a labeled DNA probe to detect a specific DNA sequence in a complex DNA sample that has been separated by restriction-digest and gel electrophoresis. Critically for the technique to succeed the probe must be unique to the target locus so as not to cross-hybridize to other endogenous DNA within the sample. Investigators routinely employ a manual approach to probe design. A genome browser is used to extract DNA sequence from the locus of interest, which is searched against the target genome using a BLAST-like tool. Ideally a single perfect match is obtained to the target, with little cross-reactivity caused by homologous DNA sequence present in the genome and/or repetitive and low-complexity elements in the candidate probe. This is a labor intensive process often requiring several attempts to find a suitable probe for laboratory testing. Results We have written an informatic pipeline to automatically design genomic Sothern blot probes that specifically attempts to optimize the resultant probe, employing a brute-force strategy of generating many candidate probes of acceptable length in the user-specified design window, searching all against the target genome, then scoring and ranking the candidates by uniqueness and repetitive DNA element content. Using these in silico measures we can automatically design probes that we predict to perform as well, or better, than our previous manual designs, while considerably reducing design time. We went on to

  13. Fast and reliable method of conductive carbon nanotube-probe fabrication for scanning probe microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Dremov, Vyacheslav, E-mail: dremov@issp.ac.ru; Fedorov, Pavel; Grebenko, Artem [Institute of Solid State Physics, RAS, 142432 Chernogolovka (Russian Federation); Interdisciplinary Center for Basic Research, Moscow Institute of Physics and Technology, 141700 Dolgoprudniy (Russian Federation); Fedoseev, Vitaly [Institute of Solid State Physics, RAS, 142432 Chernogolovka (Russian Federation)

    2015-05-15

    We demonstrate the procedure of scanning probe microscopy (SPM) conductive probe fabrication with a single multi-walled carbon nanotube (MWNT) on a silicon cantilever pyramid. The nanotube bundle reliably attached to the metal-covered pyramid is formed using dielectrophoresis technique from the MWNT suspension. It is shown that the dimpled aluminum sample can be used both for shortening/modification of the nanotube bundle by applying pulse voltage between the probe and the sample and for controlling the probe shape via atomic force microscopy imaging the sample. Carbon nanotube attached to cantilever covered with noble metal is suitable for SPM imaging in such modulation regimes as capacitance contrast microscopy, Kelvin probe microscopy, and scanning gate microscopy. The majority of such probes are conductive with conductivity not degrading within hours of SPM imaging.

  14. Muons as hyperfine interaction probes in chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Ghandi, Khashayar, E-mail: kghandi@triumf.ca; MacLean, Amy [Mount Allison University, Department of Chemistry & Biochemistry (Canada)

    2015-04-15

    Spin polarized positive muons injected in matter serve as magnetic probes for the investigation of physical and chemical properties of free radicals, mechanisms of free radical reactions and their formations, and radiation effects. All muon techniques rely on the evolution of spin polarization (of the muon) and in that respect are similar to conventional magnetic resonance techniques. The applications of the muon as a hyperfine probe in several fields in chemistry are described.

  15. DESIGN OF THE CONTACT POTENTIALS DIFFERENCE PROBES

    OpenAIRE

    K. U. Pantsialeyeu; U. A. Mikitsevich; A. L. Zharin

    2016-01-01

    The contact potential difference probes distinguished by great variety and produced mostly in the laboratory for specific experimental applications. As a rule, they consist of commercially available instrumentation, and have a number of disadvantages: large dimensions, complexity and high cost, small sensitivity, operating speed, noiseproof, etc. The purpose of this paper is to describe the basic approaches to design of the small dimension, complete contact potential difference probes, provid...

  16. Plasma diagnostics by means of electric probes

    International Nuclear Information System (INIS)

    In this work a summary of the classical theoretical models to interpret the characteristic curve of a Langmuir electric probe placed in a plasma without magnetic field and with the one is made. The methodology for the electron temperature calculation and the density of the plasma in both cases is given, starting from the characteristic curve of the probe, as well as the approaches for the correct application of this diagnostic method of the plasma. (Author)

  17. Statistical Fluctuations as Probes of Dense Matter

    OpenAIRE

    Müller, Berndt

    2001-01-01

    The use of statistical fluctuations as probes of the microscopic dynamics of hot and dense hadronic matter is reviewed. Critical fluctuations near the critical point of QCD matter are predicted to enhance fluctuations in pionic observables. Chemical fluctuations, especially those of locally conserved quantum numbers, such as electric charge and baryon number, can probe the nature of the carriers of these quantum numbers in the dense medium.

  18. Precision Probes of a Leptophobic Z' Boson

    OpenAIRE

    Buckley, Matthew R.; Ramsey-Musolf, Michael J.

    2012-01-01

    Extensions of the Standard Model that contain leptophobic Z' gauge bosons are theoretically interesting but difficult to probe directly in high-energy hadron colliders. However, precision measurements of Standard Model neutral current processes can provide powerful indirect tests. We demonstrate that parity-violating deep inelastic scattering of polarized electrons off of deuterium offer a unique probe leptophobic Z' bosons with axial quark couplings and masses above 100 GeV. In addition to c...

  19. Building versatile bipartite probes for quantum metrology

    OpenAIRE

    Farace, A.; De Pasquale, A; Adesso, G.; Giovannetti, V.

    2015-01-01

    We consider bipartite systems as versatile probes for the estimation of transformations acting locally on one of the subsystems. We investigate what resources are required for the probes to offer a guaranteed level of metrological performance, when the latter is averaged over specific sets of local transformations. We quantify such a performance via the average skew information, a convex quantity which we compute in closed form for bipartite states of arbitrary dimensions, and which is shown ...

  20. Phoenix Conductivity Probe with Shadow and Toothmark

    Science.gov (United States)

    2008-01-01

    NASA's Phoenix Mars Lander inserted the four needles of its thermal and conductivity probe into Martian soil during the 98th Martian day, or sol, of the mission and left it in place until Sol 99 (Sept. 4, 2008). The Robotic Arm Camera on Phoenix took this image on the morning of Sol 99 after the probe was lifted away from the soil. The imprint left by the insertion is visible below the probe, and a shadow showing the probe's four needles is cast on a rock to the left. The thermal and conductivity probe measures how fast heat and electricity move from one needle to an adjacent one through the soil or air between the needles. Conductivity readings can be indicators about water vapor, water ice and liquid water. The probe is part of Phoenix's Microscopy, Electrochemistry and Conductivity suite of instruments. The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  1. The Hera Saturn Entry Probe Mission

    CERN Document Server

    Mousis, O; Spilker, T; Venkatapathy, E; Poncy, J; Frampton, R; Coustenis, A; Reh, K; Lebreton, J -P; Fletcher, L N; Hueso, R; Amato, M J; Colaprete, A; Ferri, F; Stam, D; Wurz, P; Atreya, S; Aslam, S; Banfield, D J; Calcutt, S; Fischer, G; Holland, A; Keller, C; Kessler, E; Leese, M; Levacher, P; Morse, A; Munoz, O; Renard, J -B; Sheridan, S; Schmider, F -X; Snik, F; Waite, J H; Bird, M; Cavalié, T; Deleuil, M; Fortney, J; Gautier, D; Guillot, T; Lunine, J I; Marty, B; Nixon, C; Orton, G S; Sanchez-Lavega, A

    2015-01-01

    The Hera Saturn entry probe mission is proposed as an M--class mission led by ESA with a contribution from NASA. It consists of one atmospheric probe to be sent into the atmosphere of Saturn, and a Carrier-Relay spacecraft. In this concept, the Hera probe is composed of ESA and NASA elements, and the Carrier-Relay Spacecraft is delivered by ESA. The probe is powered by batteries, and the Carrier-Relay Spacecraft is powered by solar panels and batteries. We anticipate two major subsystems to be supplied by the United States, either by direct procurement by ESA or by contribution from NASA: the solar electric power system (including solar arrays and the power management and distribution system), and the probe entry system (including the thermal protection shield and aeroshell). Hera is designed to perform in situ measurements of the chemical and isotopic compositions as well as the dynamics of Saturn's atmosphere using a single probe, with the goal of improving our understanding of the origin, formation, and ev...

  2. Building versatile bipartite probes for quantum metrology

    Science.gov (United States)

    Farace, Alessandro; De Pasquale, Antonella; Adesso, Gerardo; Giovannetti, Vittorio

    2016-01-01

    We consider bipartite systems as versatile probes for the estimation of transformations acting locally on one of the subsystems. We investigate what resources are required for the probes to offer a guaranteed level of metrological performance, when the latter is averaged over specific sets of local transformations. We quantify such a performance via the average skew information (AvSk), a convex quantity which we compute in closed form for bipartite states of arbitrary dimensions, and which is shown to be strongly dependent on the degree of local purity of the probes. Our analysis contrasts and complements the recent series of studies focused on the minimum, rather than the average, performance of bipartite probes in local estimation tasks, which was instead determined by quantum correlations other than entanglement. We provide explicit prescriptions to characterize the most reliable states maximizing the AvSk, and elucidate the role of state purity, separability and correlations in the classification of optimal probes. Our results can help in the identification of useful resources for sensing, estimation and discrimination applications when complete knowledge of the interaction mechanism realizing the local transformation is unavailable, and access to pure entangled probes is technologically limited.

  3. Tunable third-harmonic probe for non-degenerate ultrafast pump–probe measurements

    Indian Academy of Sciences (India)

    Asha Singh; Salahuddin Khan; Podili Sivasankaraiah; J Jayabalan; Rama Chari

    2014-02-01

    In this article, we report a method to achieve a precisely tunable highly stable probe beam generation for performing pump–probe experiment around a given wavelength by tilting a sum frequency generation (SFG) crystal angle. The width of the generated third-harmonic beam is of the order of 2 nm throughout the tunable range. This method of probe beam generation has its application in isolating contributions from closely separated excitation states.

  4. Plasma density measurement with ring-type cutoff probe

    International Nuclear Information System (INIS)

    We proposed a cutoff probe with a ring-type detection tip enclosing a bar-type radiation tip. A comparative study between a proposed ring-type cutoff (RTC) probe and a conventional bar-type cutoff (BTC) probe showed that the RTC probe solved the problem of the BTC probe, the large measurement uncertainty of the electron density in a capacitively coupled plasma source. This improved characteristics of the RTC probe might have originated from the geometrical structure of the RTC probe concerning the monopole antennae radiation. This proposed cutoff probe can be expected to expand the applicable diagnostic range and to enhance the sensitivity of the cutoff probe. - Highlights: ► A cutoff probe with a ring type detection tip is proposed. ► Comparative experiment and simulation were conducted. ► The proposed probe showed a small uncertainty of measured plasma density. ► Improved characteristics might be originated from the geometrical structure

  5. ProbeMaker: an extensible framework for design of sets of oligonucleotide probes

    Directory of Open Access Journals (Sweden)

    Nilsson Mats

    2005-09-01

    Full Text Available Abstract Background Procedures for genetic analyses based on oligonucleotide probes are powerful tools that can allow highly parallel investigations of genetic material. Such procedures require the design of large sets of probes using application-specific design constraints. Results ProbeMaker is a software framework for computer-assisted design and analysis of sets of oligonucleotide probe sequences. The tool assists in the design of probes for sets of target sequences, incorporating sequence motifs for purposes such as amplification, visualization, or identification. An extension system allows the framework to be equipped with application-specific components for evaluation of probe sequences, and provides the possibility to include support for importing sequence data from a variety of file formats. Conclusion ProbeMaker is a suitable tool for many different oligonucleotide design and analysis tasks, including the design of probe sets for various types of parallel genetic analyses, experimental validation of design parameters, and in silico testing of probe sequence evaluation algorithms.

  6. Accuracy of micro four-point probe measurements on inhomogeneous samples: A probe spacing dependence study

    DEFF Research Database (Denmark)

    Wang, Fei; Petersen, Dirch Hjorth; Østerberg, Frederik Westergaard;

    2009-01-01

    In this paper, we discuss a probe spacing dependence study in order to estimate the accuracy of micro four-point probe measurements on inhomogeneous samples. Based on sensitivity calculations, both sheet resistance and Hall effect measurements are studied for samples (e.g. laser annealed samples...... the probe spacing is smaller than 1/40 of the variation wavelength, micro four-point probes can provide an accurate record of local properties with less than 1% measurement error. All the calculations agree well with previous experimental results....

  7. Dual active surface heat flux gage probe

    Science.gov (United States)

    Liebert, Curt H.; Kolodziej, Paul

    1995-02-01

    A unique plug-type heat flux gage probe was tested in the NASA Ames Research Center 2x9 turbulent flow duct facility. The probe was fabricated by welding a miniature dual active surface heat flux gage body to the end of a hollow metal cylindrical bolt containing a metal inner tube. Cooling air flows through the inner tube, impinges onto the back of the gage body and then flows out through the annulus formed between the inner tube and the hollow bolt wall. Heat flux was generated in the duct facility with a Huels arc heater. The duct had a rectangular cross section and one wall was fabricated from 2.54 centimeter thick thermal insulation rigid surface material mounted onto an aluminum plate. To measure heat flux, the probe was inserted through the plate and insulating materials with the from of the gage located flush with the hot gas-side insulation surface. Absorbed heat fluxes measured with the probe were compared with absorbed heat fluxes measured with six water-cooled reference calorimeters. These calorimeters were located in a water-cooled metal duct wall which was located across from the probe position. Correspondence of transient and steady heat fluxes measured with the reference calorimeters and heat flux gage probe was generally within a satisfactory plus or minus 10 percent. This good correspondence was achieved even though the much cooler probe caused a large surface temperature disruption of 1000K between the metal gage and the insulation. However, this temperature disruption did not seriously effect the accuracy of the heat flux measurement. A current application for dual active surface heat flux gages is for transient and steady absorbed heat flux, surface temperature and heat transfer coefficient measurements on the surface of an oxidizer turbine inlet deflector operating in a space shuttle test bed engine.

  8. The Hera Saturn entry probe mission

    Science.gov (United States)

    Mousis, O.; Atkinson, D. H.; Spilker, T.; Venkatapathy, E.; Poncy, J.; Frampton, R.; Coustenis, A.; Reh, K.; Lebreton, J.-P.; Fletcher, L. N.; Hueso, R.; Amato, M. J.; Colaprete, A.; Ferri, F.; Stam, D.; Wurz, P.; Atreya, S.; Aslam, S.; Banfield, D. J.; Calcutt, S.; Fischer, G.; Holland, A.; Keller, C.; Kessler, E.; Leese, M.; Levacher, P.; Morse, A.; Muñoz, O.; Renard, J.-B.; Sheridan, S.; Schmider, F.-X.; Snik, F.; Waite, J. H.; Bird, M.; Cavalié, T.; Deleuil, M.; Fortney, J.; Gautier, D.; Guillot, T.; Lunine, J. I.; Marty, B.; Nixon, C.; Orton, G. S.; Sánchez-Lavega, A.

    2016-10-01

    The Hera Saturn entry probe mission is proposed as an M-class mission led by ESA with a contribution from NASA. It consists of one atmospheric probe to be sent into the atmosphere of Saturn, and a Carrier-Relay spacecraft. In this concept, the Hera probe is composed of ESA and NASA elements, and the Carrier-Relay Spacecraft is delivered by ESA. The probe is powered by batteries, and the Carrier-Relay Spacecraft is powered by solar panels and batteries. We anticipate two major subsystems to be supplied by the United States, either by direct procurement by ESA or by contribution from NASA: the solar electric power system (including solar arrays and the power management and distribution system), and the probe entry system (including the thermal protection shield and aeroshell). Hera is designed to perform in situ measurements of the chemical and isotopic compositions as well as the dynamics of Saturn's atmosphere using a single probe, with the goal of improving our understanding of the origin, formation, and evolution of Saturn, the giant planets and their satellite systems, with extrapolation to extrasolar planets. Hera's aim is to probe well into the cloud-forming region of the troposphere, below the region accessible to remote sensing, to the locations where certain cosmogenically abundant species are expected to be well mixed. By leading to an improved understanding of the processes by which giant planets formed, including the composition and properties of the local solar nebula at the time and location of giant planet formation, Hera will extend the legacy of the Galileo and Cassini missions by further addressing the creation, formation, and chemical, dynamical, and thermal evolution of the giant planets, the entire solar system including Earth and the other terrestrial planets, and formation of other planetary systems.

  9. Design and synthesis of paramagnetic probes for structural biology

    NARCIS (Netherlands)

    Liu, Wei-Min

    2013-01-01

    The majority of the work presented in this thesis involves the design and synthesis of paramagnetic NMR probes, including lanthanoids caged probes and spin labels. An overview of the development of different types of lanthanoids caged probes is given. Among all of the reported lanthanoid probes, the

  10. Formative Assessment Probes: Big and Small Seeds. Linking Formative Assessment Probes to the Scientific Practices

    Science.gov (United States)

    Keeley, Page

    2016-01-01

    This column focuses on promoting learning through assessment. Formative assessment probes are designed to uncover students' ideas about objects, events, and processes in the natural world. This assessment information is then used throughout instruction to move students toward an understanding of the scientific ideas behind the probes. During the…

  11. Scanning probe image wizard: A toolbox for automated scanning probe microscopy data analysis

    Science.gov (United States)

    Stirling, Julian; Woolley, Richard A. J.; Moriarty, Philip

    2013-11-01

    We describe SPIW (scanning probe image wizard), a new image processing toolbox for SPM (scanning probe microscope) images. SPIW can be used to automate many aspects of SPM data analysis, even for images with surface contamination and step edges present. Specialised routines are available for images with atomic or molecular resolution to improve image visualisation and generate statistical data on surface structure.

  12. In-vitro accuracy and reproducibility evaluation of probing depth measurements of selected periodontal probes

    Directory of Open Access Journals (Sweden)

    K.N. Al Shayeb

    2014-01-01

    Conclusion: Depth measurements with the Chapple UB-CF-15 probe were more accurate and reproducible compared to measurements with the Vivacare TPS and Williams 14 W probes. This in vitro model may be useful for intra-examiner calibration or clinician training prior to the clinical evaluation of patients or in longitudinal studies involving periodontal evaluation.

  13. Modeling the Insertion Mechanics of Flexible Neural Probes Coated with Sacrificial Polymers for Optimizing Probe Design.

    Science.gov (United States)

    Singh, Sagar; Lo, Meng-Chen; Damodaran, Vinod B; Kaplan, Hilton M; Kohn, Joachim; Zahn, Jeffrey D; Shreiber, David I

    2016-01-01

    Single-unit recording neural probes have significant advantages towards improving signal-to-noise ratio and specificity for signal acquisition in brain-to-computer interface devices. Long-term effectiveness is unfortunately limited by the chronic injury response, which has been linked to the mechanical mismatch between rigid probes and compliant brain tissue. Small, flexible microelectrodes may overcome this limitation, but insertion of these probes without buckling requires supporting elements such as a stiff coating with a biodegradable polymer. For these coated probes, there is a design trade-off between the potential for successful insertion into brain tissue and the degree of trauma generated by the insertion. The objective of this study was to develop and validate a finite element model (FEM) to simulate insertion of coated neural probes of varying dimensions and material properties into brain tissue. Simulations were performed to predict the buckling and insertion forces during insertion of coated probes into a tissue phantom with material properties of brain. The simulations were validated with parallel experimental studies where probes were inserted into agarose tissue phantom, ex vivo chick embryonic brain tissue, and ex vivo rat brain tissue. Experiments were performed with uncoated copper wire and both uncoated and coated SU-8 photoresist and Parylene C probes. Model predictions were found to strongly agree with experimental results (model also revealed the effects of manufacturing flaws on insertion potential. PMID:26959021

  14. Full silicon-nitride probes with corner lithography wireframes for scanning Hall probe microscopy

    NARCIS (Netherlands)

    Hatakeyama, K.; Sarajlic, E.; Siekman, M.H.; Huijink, R.; Abelmann, L.

    2012-01-01

    We present a improvement of our previous design of wireframe tips for scanning Hall probes. By doubling the separation between electrode structures and cantilever base, the yield could be raised from less than 10% to over 75%. To avoid build up of stress gradients, the entire probe is manufactured f

  15. Holographic backgrounds from D-brane probes

    CERN Document Server

    Moskovic, Micha

    2014-01-01

    This thesis focuses on the derivation of holographic backgrounds from the field theory side, without using any supergravity equations of motion. Instead, we rely on the addition of probe D-branes to the stack of D-branes generating the background. From the field theory description of the probe branes, one can compute an effective action for the probes (in a suitable low-energy/near-horizon limit) by integrating out the background branes. Comparing this action with the generic probe D-brane action then allows to determine the holographic background dual to the considered field theory vacuum. In the first part, the required pre-requisites of field and string theory are recalled and this strategy to derive holographic backgrounds is explained in more detail on the basic case of D3-branes in flat space probed by a small number of D-instantons. The second part contains our original results, which have already appeared in arXiv:1301.3738, arXiv:1301.7062 and arXiv:1312.0621. We first derive the duals to three conti...

  16. Chromosome-specific DNA Repeat Probes

    Energy Technology Data Exchange (ETDEWEB)

    Baumgartner, Adolf; Weier, Jingly Fung; Weier, Heinz-Ulrich G.

    2006-03-16

    In research as well as in clinical applications, fluorescence in situ hybridization (FISH) has gained increasing popularity as a highly sensitive technique to study cytogenetic changes. Today, hundreds of commercially available DNA probes serve the basic needs of the biomedical research community. Widespread applications, however, are often limited by the lack of appropriately labeled, specific nucleic acid probes. We describe two approaches for an expeditious preparation of chromosome-specific DNAs and the subsequent probe labeling with reporter molecules of choice. The described techniques allow the preparation of highly specific DNA repeat probes suitable for enumeration of chromosomes in interphase cell nuclei or tissue sections. In addition, there is no need for chromosome enrichment by flow cytometry and sorting or molecular cloning. Our PCR-based method uses either bacterial artificial chromosomes or human genomic DNA as templates with {alpha}-satellite-specific primers. Here we demonstrate the production of fluorochrome-labeled DNA repeat probes specific for human chromosomes 17 and 18 in just a few days without the need for highly specialized equipment and without the limitation to only a few fluorochrome labels.

  17. Approaches for drug delivery with intracortical probes.

    Science.gov (United States)

    Spieth, Sven; Schumacher, Axel; Trenkle, Fabian; Brett, Olivia; Seidl, Karsten; Herwik, Stanislav; Kisban, Sebastian; Ruther, Patrick; Paul, Oliver; Aarts, Arno A A; Neves, Hercules P; Rich, P Dylan; Theobald, David E; Holtzman, Tahl; Dalley, Jeffrey W; Verhoef, Bram-Ernst; Janssen, Peter; Zengerle, Roland

    2014-08-01

    Intracortical microprobes allow the precise monitoring of electrical and chemical signaling and are widely used in neuroscience. Microelectromechanical system (MEMS) technologies have greatly enhanced the integration of multifunctional probes by facilitating the combination of multiple recording electrodes and drug delivery channels in a single probe. Depending on the neuroscientific application, various assembly strategies are required in addition to the microprobe fabrication itself. This paper summarizes recent advances in the fabrication and assembly of micromachined silicon probes for drug delivery achieved within the EU-funded research project NeuroProbes. The described fabrication process combines a two-wafer silicon bonding process with deep reactive ion etching, wafer grinding, and thin film patterning and offers a maximum in design flexibility. By applying this process, three general comb-like microprobe designs featuring up to four 8-mm-long shafts, cross sections from 150×200 to 250×250 µm², and different electrode and fluidic channel configurations are realized. Furthermore, we discuss the development and application of different probe assemblies for acute, semichronic, and chronic applications, including comb and array assemblies, floating microprobe arrays, as well as the complete drug delivery system NeuroMedicator for small animal research.

  18. VelProbePE: An automated spreadsheet program for interpreting point velocity probe breakthrough curves

    Science.gov (United States)

    Schillig, P. C.

    2012-02-01

    Groundwater velocity is an important parameter for determining the fate and transport of contaminants. Recently developed point velocity probes (PVPs) were designed to provide centimeter-scale measurements of the direction and magnitude of groundwater velocity based on the injection and electrical detection of a small, saline tracer. The code reported here for velocity probe parameter estimation (VelProbePE) was designed using Visual Basic for Applications (VBA) in Microsoft Excel for processing and interpreting tracer breakthrough curves specifically for PVP applications. VelProbePE contains multiple, autoinitializing user forms that guide the user through the data-processing steps. The program allows for the rapid processing and editing of up to 16 detector signals in a single workbook. VelProbePE uses simplex optimization to calculate the intermediate parameters required for the estimation of velocity magnitude and direction.

  19. Dual-probe decoherence microscopy: Probing pockets of coherence in a decohering environment

    CERN Document Server

    Jeske, Jan; Müller, Clemens; Marthaler, Michael; Schön, Gerd

    2011-01-01

    We study the use of a pair of qubits as a decoherence probe of a non-trivial environment. This dual-probe configuration is modelled by three two-level-systems which are coupled in a chain in which the middle system represents an environmental two-level-system (TLS). This TLS resides within the environment of the qubits and therefore its coupling to perturbing fluctuations (i.e. its decoherence) is assumed much stronger than the decoherence acting on the probe qubits. We study the evolution of such a tripartite system including the appearance of a decoherence-free state (dark state) and non-Markovian behaviour. We find that all parameters of this TLS can be obtained from measurements of one of the probe qubits. Furthermore we show the advantages of two qubits in probing environments and the new dynamics imposed by a TLS which couples to two qubits at once.

  20. Venus within ESA probe reach

    Science.gov (United States)

    2006-03-01

    Venus Express mission controllers at the ESA Space Operations Centre (ESOC) in Darmstadt, Germany are making intensive preparations for orbit insertion. This comprises a series of telecommands, engine burns and manoeuvres designed to slow the spacecraft down from a velocity of 29000 km per hour relative to Venus, just before the first burn, to an entry velocity some 15% slower, allowing the probe to be captured into orbit around the planet. The spacecraft will have to ignite its main engine for 50 minutes in order to achieve deceleration and place itself into a highly elliptical orbit around the planet. Most of its 570 kg of onboard propellant will be used for this manoeuvre. The spacecraft’s solar arrays will be positioned so as to reduce the possibility of excessive mechanical load during engine ignition. Over the subsequent days, a series of additional burns will be done to lower the orbit apocentre and to control the pericentre. The aim is to end up in a 24-hour orbit around Venus early in May. The Venus orbit injection operations can be followed live at ESA establishments, with ESOC acting as focal point of interest (see attached programme). In all establishments, ESA specialists will be on hand for interviews. ESA TV will cover this event live from ESOC in Darmstadt. The live transmission will be carried free-to-air. For broadcasters, complete details of the various satellite feeds are listed at http://television.esa.int. The event will be covered on the web at venus.esa.int. The website will feature regular updates, including video coverage of the press conference and podcast from the control room at ESA’s Operations Centre. Media representatives wishing to follow the event at one of the ESA establishments listed below are requested to fill in the attached registration form and fax it back to the place of their choice. For further information, please contact: ESA Media Relations Division Tel : +33(0)1.53.69.7155 Fax: +33(0)1.53.69.7690 Venus Express

  1. Design and Applications of A 3D Precision Probe

    Institute of Scientific and Technical Information of China (English)

    YANG Lian-gen; LIU Xin-biao; XIE Tie-bang

    2005-01-01

    A 3D probe used for NC copying process is proposed in the paper. The construction of parallel springs is adopted in the probe. It has compact structure and little volume. By adjusting spring force and improving sensitivity, the probe can be used in CMM. Errors of the probe are analysed.Performances of the probe are verified by test of measuring force, verification of precision of single axis and plane precision.

  2. Remote tuning of NMR probe circuits.

    Science.gov (United States)

    Kodibagkar, V D; Conradi, M S

    2000-05-01

    There are many circumstances in which the probe tuning adjustments cannot be located near the rf NMR coil. These may occur in high-temperature NMR, low-temperature NMR, and in the use of magnets with small diameter access bores. We address here circuitry for connecting a fixed-tuned probe circuit by a transmission line to a remotely located tuning network. In particular, the bandwidth over which the probe may be remotely tuned while keeping the losses in the transmission line acceptably low is considered. The results show that for all resonant circuit geometries (series, parallel, series-parallel), overcoupling of the line to the tuned circuit is key to obtaining a large tuning bandwidth. At equivalent extents of overcoupling, all resonant circuit geometries have nearly equal remote tuning bandwidths. Particularly for the case of low-loss transmission line, the tuning bandwidth can be many times the tuned circuit's bandwidth, f(o)/Q. PMID:10783273

  3. Fireside corrosion probes--an update

    Energy Technology Data Exchange (ETDEWEB)

    Covino, B.S., Jr.; Bullard, S.J.; Holcomb, G.R.; Ziomek-Moroz, M.; Matthes, S.A.

    2007-01-01

    The ability to monitor the corrosion degradation of key metallic components in fossil fuel power plants will become increasingly important for FutureGen and ultra-supercritical power plants. A number of factors (ash deposition, coal composition changes, thermal gradients, and low NOx conditions, among others) which occur in the high temperature sections of energy production facilities, will contribute to fireside corrosion. Several years of research have shown that high temperature corrosion rate probes need to be better understood before corrosion rate can be used as a process variable by power plant operators. Our recent research has shown that electrochemical corrosion probes typically measure lower corrosion rates than those measured by standard mass loss techniques. While still useful for monitoring changes in corrosion rates, absolute probe corrosion rates will need a calibration factor to be useful. Continuing research is targeted to help resolve these issues.

  4. Plasmonic corrugated cylinder-cone terahertz probe.

    Science.gov (United States)

    Yao, Haizi; Zhong, Shuncong

    2014-08-01

    The spoof surface plasmon polariton (SPP) effect on the electromagnetic field distribution near the tip of a periodically corrugated metal cylinder-cone probe working at the terahertz regime was studied. We found that radially polarized terahertz radiation could be coupled effectively through a spoof SPP into a surface wave and propagated along the corrugated surface, resulting in more than 20× electric field enhancement near the tip of probe. Multiple resonances caused by the antenna effect were discussed in detail by finite element computation and theoretical analysis of dispersion relation for spoof SPP modes. Moreover, the key figures of merit such as the resonance frequency of the SPP can be flexibly tuned by modifying the geometry of the probe structure, making it attractive for application in an apertureless background-free terahertz near-field microscope. PMID:25121543

  5. Magnetic measurements at 'GANIL' - Hall probe utilization

    International Nuclear Information System (INIS)

    This work was intended for developing a magnetic field measuring bench, and for investigating the various methods of magnetic measurements capable to answer the requirements from GANIL users: NMR, magnetoresistance, Hall probes, rotating coils. Two methods only are shown to fulfill the requirements from GANIL users: the Hall probe measuring method, and the method of the rotating coils. A great advantage of the Hall probe method is due to the simpleness of its electronic equipment, and the possibility of measuring fields with sharp variations in time, in view of the short response time of Hall effect. The method is most suitable for azimuthal measurements and determining heterogeneities in the magnetic field. A prevailing advantage of the rotating coil method is its linearity due to the direct read-out of the magnetic field with using a single constant over the whole range of measurement. The method is most suitable for field differential measurements

  6. Molecular probes for malignant melanoma imaging.

    Science.gov (United States)

    Ren, Gang; Pan, Ying; Cheng, Zhen

    2010-09-01

    Malignant melanoma represents a serious public health problem and is a deadly disease when it is diagnosed at late stage. Though (18)F-fluorodeoxyglucose ((18)F-FDG) positron emission tomography (PET) has been widely used clinically for melanoma imaging, other approaches to specifically identify, characterize, monitor and guide therapeutics for malignant melanoma are still needed. Consequently, many probes targeting general molecular events including metabolism, angiogenesis, hypoxia and apoptosis in melanoma have been successfully developed. Furthermore, probes targeting melanoma associated targets such as melanocortin receptor 1 (MC1R), melanin, etc. have undergone active investigation and have demonstrated high melanoma specificity. In this review, these molecular probes targeting diverse melanoma biomarkers have been summarized. Some of them may eventually contribute to the improvement of personalized management of malignant melanoma. PMID:20497118

  7. Protease-activated quantum dot probes

    Science.gov (United States)

    Chang, Emmanuel; Sun, Jiantang; Miller, Jordan S.; Yu, William W.; Colvin, Vicki L.; West, Jennifer L.; Drezek, Rebekah

    2006-04-01

    We demonstrate a novel quantum dot based probe with inherent signal amplification upon interaction with a targeted proteolytic enzyme. This probe may be useful for imaging in cancer detection and diagnosis. In this system, quantum dots (QDs) are bound to gold nanoparticles (AuNPs) via a proteolytically-degradable peptide sequence to non-radiatively suppress luminescence. A 71% reduction in luminescence was achieved with conjugation of AuNPs to QDs. Peptide cleavage results in release of AuNPs and restores radiative QD photoluminescence. Initial studies observed a 52% rise in luminescence over 47 hours of exposure to 0.2 mg/mL collagenase. These probes can be customized for targeted degradation simply by changing the sequence of the peptide linker.

  8. Spin probes for electron paramagnetic resonance imaging

    Institute of Scientific and Technical Information of China (English)

    YAN GuoPing; PENG Lei; JIAN ShuangQuan; LI Liang; BOTTLE Steven Eric

    2008-01-01

    Electron paramagnetic resonance imaging (EPRI) is a relatively recent imaging technique, which provides potentially multidimensional imaging of the spatial distribution of paramagnetic species. Thanks to the use of stable spin probes, low frequency EPR imaging has recently allowed the use of large tissue samples or whole animals in vivo in the field of biology and medicine. It is normally necessary to introduce prior intravenous or intramuscular infusion of stable or slowly metabolizable non-toxic water-soluble paramagnetic materials, or stable implantable particulate materials as spin probes into the system. The classification and research progress of spin probes at present were described briefly.Three important potential approaches in water-soluble paramagnetic materials design including deuterated, site-specific and macromolecular conjugated nitroxides were also investigated.

  9. Universal microbial diagnostics using random DNA probes

    Science.gov (United States)

    Aghazadeh, Amirali; Lin, Adam Y.; Sheikh, Mona A.; Chen, Allen L.; Atkins, Lisa M.; Johnson, Coreen L.; Petrosino, Joseph F.; Drezek, Rebekah A.; Baraniuk, Richard G.

    2016-01-01

    Early identification of pathogens is essential for limiting development of therapy-resistant pathogens and mitigating infectious disease outbreaks. Most bacterial detection schemes use target-specific probes to differentiate pathogen species, creating time and cost inefficiencies in identifying newly discovered organisms. We present a novel universal microbial diagnostics (UMD) platform to screen for microbial organisms in an infectious sample, using a small number of random DNA probes that are agnostic to the target DNA sequences. Our platform leverages the theory of sparse signal recovery (compressive sensing) to identify the composition of a microbial sample that potentially contains novel or mutant species. We validated the UMD platform in vitro using five random probes to recover 11 pathogenic bacteria. We further demonstrated in silico that UMD can be generalized to screen for common human pathogens in different taxonomy levels. UMD’s unorthodox sensing approach opens the door to more efficient and universal molecular diagnostics. PMID:27704040

  10. Doubling Strong Lensing as a Cosmological Probe

    CERN Document Server

    Linder, Eric V

    2016-01-01

    Strong gravitational lensing provides a geometric probe of cosmology in a unique manner through distance ratios involving the source and lens. This is well known for the time delay distance derived from measured delays between lightcurves of the images of variable sources such as quasars. Recently, double source plane lens systems involving two constant sources lensed by the same foreground lens have been proposed as another probe, involving a different ratio of distances measured from the image positions and fairly insensitive to the lens modeling. Here we demonstrate that these two different sets of strong lensing distance ratios have strong complementarity in cosmological leverage. Unlike other probes, the double source distance ratio is actually more sensitive to the dark energy equation of state parameters $w_0$ and $w_a$ than to the matter density $\\Omega_m$, for low redshift lenses. Adding double source distance ratio measurements can improve the dark energy figure of merit by 40% for a sample of fewer...

  11. Saturn Probe: Revealing Solar System Origins

    Science.gov (United States)

    Spilker, T. R.

    2015-12-01

    Comparative studies of the gas giant and ice giant planets are needed to reliably discriminate among competing theories of the origin and evolution of giant planets and the solar system, but we lack critical measurements. A Saturn atmospheric entry probe mission would fill a vital part of that gap, allowing comparative studies of Jupiter and Saturn, providing the basis for later comparisons with the ice giants Uranus and Neptune, and informing studies of extrasolar planetary systems now being characterized. The Galileo Probe mission provided the first in situ studies of Jupiter's atmosphere. Similar measurements at Saturn, Uranus and Neptune would provide an important comparative planetology context for the Galileo results. Cassini's "Proximal Orbits" in 2017 will reveal Saturn's internal structure to complement the Juno mission's similar measurements at Jupiter. A Saturn entry probe, complementing the Galileo Probe investigations at Jupiter, would complete a solid basis for improved understanding of both Jupiter and Saturn, an important stepping stone to understanding Uranus and Neptune and solar system formation and evolution. The 2012 Decadal Survey ("DS") added Saturn Probe science objectives to NASA's New Frontiers Program: highest-priority Tier 1 objectives any New Frontiers implementation must achieve, and Tier 2, high priority but lower than Tier 1. A DS mission concept study using extremely conservative assumptions concluded that a Saturn Probe project could fit within New Frontiers resource constraints, giving a PI confidence that they could pursue some Tier 2 objectives, customizing for the proper balance of science return, science team composition, procured or contributed instruments, etc. Contributed instruments could significantly enhance the payload and the science team for greater science return. They also provide international collaboration opportunities, with science benefits well demonstrated by missions such as Cassini-Huygens and Rosetta.

  12. Optical contacting for gravity probe star tracker

    Science.gov (United States)

    Wright, J. J.; Zissa, D. E.

    1984-01-01

    A star-tracker telescope, constructed entirely of fused silica elements optically contacted together, has been proposed to provide submilliarc-second pointing accuracy for Gravity Probe. A bibliography and discussion on optical contacting (the bonding of very flat, highly polished surfaces without the use of adhesives) are presented. Then results from preliminary experiments on the strength of optical contacts including a tensile strength test in liquid helium are discussed. Suggestions are made for further study to verify an optical contacting method for the Gravity Probe star-tracker telescope.

  13. DESIGN OF THE CONTACT POTENTIALS DIFFERENCE PROBES

    Directory of Open Access Journals (Sweden)

    K. U. Pantsialeyeu

    2016-01-01

    Full Text Available The contact potential difference probes distinguished by great variety and produced mostly in the laboratory for specific experimental applications. As a rule, they consist of commercially available instrumentation, and have a number of disadvantages: large dimensions, complexity and high cost, small sensitivity, operating speed, noiseproof, etc. The purpose of this paper is to describe the basic approaches to design of the small dimension, complete contact potential difference probes, providing high sensitivity, operating speed, and noise immunity. In this paper the contact potential difference probe, which is a electrometer with dynamic capacitor plate at about 0.1–5 mm2 . These probes are could be used in scanning systems, such as a Scanning Kelvin Probe, as well as for controlling system of manufacturing processes, e.g. under friction. The design of such contact potential difference probes conducted using modern electronic components, unique circuitry and design solutions described in detail at paper. The electromechanical modulator applied for mechanical vibrations of the reference sample. To provide a high amplitude and phase stability the upgraded generator with Wien bridge was used instead traditional oscillation sensor. The preamplifier made on the base of modern operational amplifiers with femtoampere current input. The power of the preamplifier designed with «floating ground». It allows keeping the relation constant potential to the probe components when changing over a wide range the compensation voltage. The phase detector-integrator based on the electronic antiphase switches with the modulation frequency of the contact potential difference and the integrator. Fullwave phase detection would greatly increase the sensitivity of the probe. In addition, the application of the phase detection allows suppressing noise and crosstalk at frequencies different from the modulation frequency. The preamplifier and the reference sample

  14. MICROMACHINED HEAT EXCHANGER FOR A CRYOSURGICAL PROBE

    OpenAIRE

    Zhu, W; Gianchandani, Yogesh B.; Nellis, G. F.; Klein, Sanford A.

    2005-01-01

    Submitted on behalf of EDA Publishing Association (http://irevues.inist.fr/handle/2042/5920) International audience This paper describes a lithography-based microfabrication process developed for a recuperative heat exchanger intended for use in a cryosurgical probe. The probe, which uses the Joule-Thomson (JT) cooling cycle, must achieve a temperature < -50°C, with a freeze rate of 25-50°C/min. The heat exchanger must maintain high stream-to-stream thermal conductance while restricting...

  15. Scintillation probe with photomultiplier tube saturation indicator

    Science.gov (United States)

    Ruch, Jeffrey F.; Urban, David J.

    1996-01-01

    A photomultiplier tube saturation indicator is formed by supplying a supplemental light source, typically an light emitting diode (LED), adjacent to the photomultiplier tube. A switch allows the light source to be activated. The light is forwarded to the photomultiplier tube by an optical fiber. If the probe is properly light tight, then a meter attached to the indicator will register the light from the LED. If the probe is no longer light tight, and the saturation indicator is saturated, no signal will be registered when the LED is activated.

  16. Collective electronic effects in scanning probe microscopy

    Science.gov (United States)

    Passian, Ali

    The surface plasmon dispersion relations are calculated for a metal coated dielectric probe above a dielectric half space with and without metal coating. Employing prolate spheroidal coordinate system this configuration was modeled as confocal single-sheeted hyperboloids of revolution superimposed on planar domains. The involved media are characterized by frequency dependent, spatially local dielectric functions. Due to subwavelength dimensions of the region of interest, nonretarded electrodynamics is utilized to derive exact analytical expressions describing the resonant surface modes. The dispersion relations are studied as functions of the parameter that defines the hyperboloidal boundaries of the tip and the corresponding coating, and as functions of the involved coating thicknesses. Both parallel and perpendicular polarizations are considered. The results are simulated numerically and limiting cases are discussed with comparison to the Cartesian thin foil case. Using this new type of probe-substrate configuration, the surface plasmon coupling mechanism is investigated experimentally utilizing a scanning probe microscope, and the signal strength acquired by the probe is measured as a function of the distance between the probe and the sample. This is repeated at three different wavelengths of the incident p-polarized photons used to stimulate surface plasmons in the thin metal foil. The results are compared with the theory. Utilizing the prolate spheroidal coordinate system, the related and relevant problem of the Coulomb interaction of a dielectric probe tip with a uniform field existing above a semiinfinite, homogeneous dielectric substrate was studied. This is of interest in atomic force microscopy when the sample surface is electrically charged. The induced polarization surface charge density and the field distribution at the bounding surface of the dielectric medium with the geometry of a single-sheeted hyperboloid of revolution located above the dielectric

  17. Probe Measures Fouling As In Heat Exchangers

    Science.gov (United States)

    Marner, Wilbur J.; Macdavid, Kenton S.

    1990-01-01

    Combustion deposits reduce transfer of heat. Instrument measures fouling like that on gas side of heat exchanger in direct-fired boiler or heat-recovery system. Heat-flux probe includes tube with embedded meter in outer shell. Combustion gases flow over probe, and fouling accumulates on it, just as fouling would on heat exchanger. Embedded heat-flow meter is sandwich structure in which thin Chromel layers and middle alloy form thermopile. Users determine when fouling approaches unacceptable levels so they schedule cleaning and avoid decreased transfer of heat and increased drop in pressure fouling causes. Avoids cost of premature, unnecessary maintenance.

  18. SNe Ia as a cosmological probe

    Science.gov (United States)

    Meng, Xiangcun; Gao, Yan; Han, Zhanwen

    2015-09-01

    Type Ia supernovae (SNe Ia) luminosities can be corrected in order to render them useful as standard candles that are able to probe the expansion history of the universe. This technique was successfully applied to discover the present acceleration of the universe. As the number of SNe Ia observed at high redshift increases and analysis techniques are perfected, people aim to use this technique to probe the equation-of-state of the dark energy (EOSDE). Nevertheless, the nature of SNe Ia progenitors remains controversial and concerns persist about possible evolution effects that may be larger and harder to characterize than the more obvious statistical uncertainties.

  19. Aggregate Formed by a Cationic Fluorescence Probe

    Institute of Scientific and Technical Information of China (English)

    TIAN, Juan; SANG, Da-Yong; JI, Guo-Zhen

    2007-01-01

    The aggregation behavior of a cationic fluorescence probe 10-(4,7,10,13,16-pentaoxa-1-azacyclooctadecyl-methyl)anthracen-9-ylmethyl dodecanoate (1) was observed and studied by a fluorescence methodology in acidic and neutral conditions. By using the Py scale, differences between simple aggregates and micelles have been discussed. The stability of simple aggregates was discussed in terms of hydrophobic interaction and electrostatic repulsion. The absence of excimer emission of the anthrancene moiety of probe 1 in neutral condition was attributed to the photoinduced electron transfer mechanism instead of photodimerization.

  20. Isotropic Broadband E-Field Probe

    Directory of Open Access Journals (Sweden)

    Béla Szentpáli

    2008-01-01

    Full Text Available An E-field probe has been developed for EMC immunity tests performed in closed space. The leads are flexible resistive transmission lines. Their influence on the field distribution is negligible. The probe has an isotropic reception from 100 MHz to 18 GHz; the sensitivity is in the 3 V/m–10 V/m range. The device is an accessory of the EMC test chamber. The readout of the field magnitude is carried out by personal computer, which fulfils also the required corrections of the raw data.

  1. The future of atom probe tomography

    Directory of Open Access Journals (Sweden)

    Michael K. Miller

    2012-04-01

    Full Text Available The dream of the microscopy and materials science communities is to see, identify, accurately locate, and determine the fundamental physical properties of every atom in a specimen. With this knowledge together with modern computer models and simulations, a full understanding of the properties of a material can be determined. This fundamental knowledge leads to the design and development of more advanced materials for solving the needs of society. The technique of atom probe tomography is the closest to fulfilling this dream but is still significantly short of the goal. The future of atom probe tomography, and the prospects for achieving this ultimate goal are outlined.

  2. A Novel Fluorescent Probe for Lead Ions

    Institute of Scientific and Technical Information of China (English)

    Ming SUN; Di Hua SHANG GUAN; Hui Min MA; Li Hua NIE; Xiao Hua LI; Shao Xiang XIONG

    2003-01-01

    A new fluorescent probe for lead ions, p-nitrophenyl 3H-phenoxazin-3-one-7-ylphosphoric acid (NPPA), has been synthesized by linking resorufin (serving as a fluorophore andelectron acceptor) to p-nitrophenol (serving as a fluorescence quencher and electron donor)through phosphodiester bonds. When NPPA was irradiated with light, intramolecularfluorescence self-quenching took place due to the PET (photoinduced electron transfer) from thedonor to the acceptor. However, upon addition of Pb , the phosphate ester bonds in the probe werecleaved and the fiuorophore was released, accompanying the retrievement of fluorescence.

  3. SNe Ia as a cosmological probe

    CERN Document Server

    Meng, Xiangcun; Han, Zhanwen

    2015-01-01

    Type Ia supernovae luminosities can be corrected to render them useful as standard candles able to probe the expansion history of the universe. This technique was successful applied to discover the present acceleration of the universe. As the number of SNe Ia observed at high redshift increases and analysis techniques are perfected, people aim to use this technique to probe the equation of state of the dark energy. Nevertheless, the nature of SNe Ia progenitors remains controversial and concerns persist about possible evolution effects that may be larger and harder to characterize than the more obvious statistical uncertainties.

  4. Probe Gain without Probe field in a V-type System with an External Field Coupling Two Upper Levels

    Institute of Scientific and Technical Information of China (English)

    BAI Yan-Feng; YANG Wen-Xing; YU Xiao-Qiang

    2011-01-01

    We report a new coherence and interference phenomenon in a V-type system with an external field coupling two upper levels. It is found that the probe gain can be generated even when no probe field is applied to the system,we attribute this result to the existence of the external field. By comparing with the conventional probe gain, the probe gain without the probe field is enhanced greatly because of the absence of the population inversion term.

  5. A cutoff probe for the measurement of high density plasma

    International Nuclear Information System (INIS)

    A cutoff probe is a diagnostic method to find the absolute plasma density through simple means. However, when the cutoff probe is used in the high density plasma diagnostics, the probe can be faced with measurement problems because the high influx energy from the plasma can damage the probe tips, especially for the dielectric material in the vicinity of the probe tips. Because this damage cannot only cause an error in the measurement of electron density but also acts as a contamination source in the plasma, a solution for the cutoff probe damage induced by high influx of ions and electrons is needed for the reliable measurement of the cutoff probe in high density plasma. To solve this problem, we proposed a cutoff probe shielded by the ceramic tube. In this paper, the authors addressed numerous aspects of the Ceramic Shielded Cutoff probe: the problems of the normal cutoff probe for the high density plasma measurement, the validity for the application of probe system to high density plasma measurement, the transmission spectrum characteristics of the cutoff probe, and the experimental/simulation results. - Highlights: ► A cutoff probe shielded by the ceramic tube is proposed. ► The installed ceramic tube helps to reduce the thermal damage of the probe. ► The cutoff frequency is hardly changed by ceramic tube installation

  6. Luminescent probes for optical in vivo imaging

    Science.gov (United States)

    Texier, Isabelle; Josserand, Veronique; Garanger, Elisabeth; Razkin, Jesus; Jin, Zhaohui; Dumy, Pascal; Favrot, Marie; Boturyn, Didier; Coll, Jean-Luc

    2005-04-01

    Going along with instrumental development for small animal fluorescence in vivo imaging, we are developing molecular fluorescent probes, especially for tumor targeting. Several criteria have to be taken into account for the optimization of the luminescent label. It should be adapted to the in vivo imaging optical conditions : red-shifted absorption and emission, limited overlap between absorption and emission for a good signal filtering, optimized luminescence quantum yield, limited photo-bleaching. Moreover, the whole probe should fulfill the biological requirements for in vivo labeling : adapted blood-time circulation, biological conditions compatibility, low toxicity. We here demonstrate the ability of the imaging fluorescence set-up developed in LETI to image the bio-distribution of molecular probes on short times after injection. Targeting with Cy5 labeled holo-transferrin of subcutaneous TS/Apc (angiogenic murine breast carcinoma model) or IGROV1 (human ovarian cancer) tumors was achieved. Differences in the kinetics of the protein uptake by the tumors were evidenced. IGROV1 internal metastatic nodes implanted in the peritoneal cavity could be detected in nude mice. However, targeted metastatic nodes in lung cancer could only be imaged after dissection of the mouse. These results validate our fluorescence imaging set-up and the use of Cy5 as a luminescent label. New fluorescent probes based on this dye and a molecular delivery template (the RAFT molecule) can thus be envisioned.

  7. Recombinant phage probes for Listeria monocytogenes

    International Nuclear Information System (INIS)

    Monitoring of food and environmental samples for biological threats, such as Listeria monocytogenes, requires probes that specifically bind biological agents and ensure their immediate and efficient detection. There is a need for robust and inexpensive affinity probes as an alternative to antibodies. These probes may be recruited from random peptide libraries displayed on filamentous phage. In this study, we selected from two phage peptide libraries phage clones displaying peptides capable of specific and strong binding to the L. monocytogenes cell surface. The ability of isolated phage clones to interact specifically with L. monocytogenes was demonstrated using enzyme-linked immunosorbent assay (ELISA) and confirmed by co-precipitation assay. We also assessed the sensitivity of phage-bacteria binding by PCR on phage-captured Listeria cells, which could be detected at a concentration of 104 cells ml-1. In addition, as proof-of-concept, we tested the possibility of immobilizing the affinity-selected phages to a putative biosensor surface. The quality of phage deposition was monitored by ELISA and fluorescent microscopy. Phage-bacterial binding was confirmed by high power optical phase contrast microscopy. Overall, the results of this work validate the concept of affinity-selected recombinant filamentous phages as probes for detecting and monitoring bacterial agents under any conditions that warrant their recognition, including in food products

  8. Recombinant phage probes for Listeria monocytogenes

    Energy Technology Data Exchange (ETDEWEB)

    Carnazza, S; Gioffre, G; Felici, F; Guglielmino, S [Department of Microbiological, Genetic and Molecular Sciences, University of Messina, Messina (Italy)

    2007-10-03

    Monitoring of food and environmental samples for biological threats, such as Listeria monocytogenes, requires probes that specifically bind biological agents and ensure their immediate and efficient detection. There is a need for robust and inexpensive affinity probes as an alternative to antibodies. These probes may be recruited from random peptide libraries displayed on filamentous phage. In this study, we selected from two phage peptide libraries phage clones displaying peptides capable of specific and strong binding to the L. monocytogenes cell surface. The ability of isolated phage clones to interact specifically with L. monocytogenes was demonstrated using enzyme-linked immunosorbent assay (ELISA) and confirmed by co-precipitation assay. We also assessed the sensitivity of phage-bacteria binding by PCR on phage-captured Listeria cells, which could be detected at a concentration of 10{sup 4} cells ml{sup -1}. In addition, as proof-of-concept, we tested the possibility of immobilizing the affinity-selected phages to a putative biosensor surface. The quality of phage deposition was monitored by ELISA and fluorescent microscopy. Phage-bacterial binding was confirmed by high power optical phase contrast microscopy. Overall, the results of this work validate the concept of affinity-selected recombinant filamentous phages as probes for detecting and monitoring bacterial agents under any conditions that warrant their recognition, including in food products.

  9. Pragmatic reconstruction methods in atom probe tomography

    International Nuclear Information System (INIS)

    Data collected in atom probe tomography have to be carefully analysed in order to give reliable composition data accurately and precisely positioned in the probed volume. Indeed, the large analysed surfaces of recent instruments require reconstruction methods taking into account not only the tip geometry but also accurate knowledge of geometrical projection parameters. This is particularly crucial in the analysis of multilayers materials or planar interfaces. The current work presents a simulation model that enables extraction of the two main projection features as a function of the tip and atom probe instrumentation geometries. Conversely to standard assumptions, the image compression factor and the field factor vary significantly during the analysis. An improved reconstruction method taking into account the intrinsic shape of a sample containing planar features is proposed to overcome this shortcoming. -- Highlights: → Tomographic reconstructions in atom probe tomography. → Model of field evaporation in a 2D non-regular geometry with cylindrical symmetry. → Calculation of the field factor and of the image compression factor. → New algorithm of reconstruction for specimen composed of flat layer structures.

  10. University scientists test Mars probe equipment

    CERN Multimedia

    2002-01-01

    Scientists at Leicester University have spent four years researching and designing the Flight Model Position Adjustable Workbench (PAW) at the university. It will be attached to the Beagle 2 probe before being sent to the Red Planet in the spring (1/2 page).

  11. Carbon nanotubes as in vivo bacterial probes

    Science.gov (United States)

    Bardhan, Neelkanth M.; Ghosh, Debadyuti; Belcher, Angela M.

    2014-09-01

    With the rise in antibiotic-resistant infections, non-invasive sensing of infectious diseases is increasingly important. Optical imaging, although safer and simpler, is less developed than other modalities such as radioimaging, due to low availability of target-specific molecular probes. Here we report carbon nanotubes (SWNTs) as bacterial probes for fluorescence imaging of pathogenic infections. We demonstrate that SWNTs functionalized using M13 bacteriophage (M13-SWNT) can distinguish between F‧-positive and F‧-negative bacterial strains. Moreover, through one-step modification, we attach an anti-bacterial antibody on M13-SWNT, making it easily tunable for sensing specific F‧-negative bacteria. We illustrate detection of Staphylococcus aureus intramuscular infections, with ~3.4 × enhancement in fluorescence intensity over background. SWNT imaging presents lower signal spread ~0.08 × and higher signal amplification ~1.4 × , compared with conventional dyes. We show the probe offers greater ~5.7 × enhancement in imaging of S. aureus infective endocarditis. These biologically functionalized, aqueous-dispersed, actively targeted, modularly tunable SWNT probes offer new avenues for exploration of deeply buried infections.

  12. A piezo-bar pressure probe

    Science.gov (United States)

    Friend, W. H.; Murphy, C. L.; Shanfield, I.

    1967-01-01

    Piezo-bar pressure type probe measures the impact velocity or pressure of a moving debris cloud. It measures pressures up to 200,000 psi and peak pressures may be recorded with a total pulse duration between 5 and 65 musec.

  13. Flow cytometry, fluorescent probes, and flashing bacteria

    NARCIS (Netherlands)

    Bunthof, C.J.

    2002-01-01

     


    Key words: fluorescent probes, flow cytometry, CSLM, viability, survival, microbial physiology, lactic acid bacteria, Lactococcus lactis , Lactobacillus plantarum , cheese, milk, probiotic In food industry there is a perceived need for rapid methods for detection and viability a

  14. High temperature electrochemical corrosion rate probes

    Energy Technology Data Exchange (ETDEWEB)

    Bullard, Sophie J.; Covino, Bernard S., Jr.; Holcomb, Gordon R.; Ziomek-Moroz, M.

    2005-09-01

    Corrosion occurs in the high temperature sections of energy production plants due to a number of factors: ash deposition, coal composition, thermal gradients, and low NOx conditions, among others. Electrochemical corrosion rate (ECR) probes have been shown to operate in high temperature gaseous environments that are similar to those found in fossil fuel combustors. ECR probes are rarely used in energy production plants at the present time, but if they were more fully understood, corrosion could become a process variable at the control of plant operators. Research is being conducted to understand the nature of these probes. Factors being considered are values selected for the Stern-Geary constant, the effect of internal corrosion, and the presence of conductive corrosion scales and ash deposits. The nature of ECR probes will be explored in a number of different atmospheres and with different electrolytes (ash and corrosion product). Corrosion rates measured using an electrochemical multi-technique capabilities instrument will be compared to those measured using the linear polarization resistance (LPR) technique. In future experiments, electrochemical corrosion rates will be compared to penetration corrosion rates determined using optical profilometry measurements.

  15. Vertically aligned nanostructure scanning probe microscope tips

    Science.gov (United States)

    Guillorn, Michael A.; Ilic, Bojan; Melechko, Anatoli V.; Merkulov, Vladimir I.; Lowndes, Douglas H.; Simpson, Michael L.

    2006-12-19

    Methods and apparatus are described for cantilever structures that include a vertically aligned nanostructure, especially vertically aligned carbon nanofiber scanning probe microscope tips. An apparatus includes a cantilever structure including a substrate including a cantilever body, that optionally includes a doped layer, and a vertically aligned nanostructure coupled to the cantilever body.

  16. Uncertainty in Quantitative Electron Probe Microanalysis

    Science.gov (United States)

    Heinrich, Kurt F. J.

    2002-01-01

    Quantitative electron probe analysis is based on models based on the physics or x-ray generation, empirically adjusted to the analyses of specimens of known composition. Their accuracy can be estimated by applying them to a set of specimens of presumably well-known composition. PMID:27446746

  17. Site Specific Evaluation of Multisensor Capacitance Probes

    Science.gov (United States)

    Multisensor capacitance probes (MCPs) are widely used for measuring soil water content (SWC) at the field scale. Although manufacturers supply a generic MCP calibration, many researchers recognize that MCPs should be calibrated for specific field conditions. MCPs measurements are typically associa...

  18. Recombinant phage probes for Listeria monocytogenes

    Science.gov (United States)

    Carnazza, S.; Gioffrè, G.; Felici, F.; Guglielmino, S.

    2007-10-01

    Monitoring of food and environmental samples for biological threats, such as Listeria monocytogenes, requires probes that specifically bind biological agents and ensure their immediate and efficient detection. There is a need for robust and inexpensive affinity probes as an alternative to antibodies. These probes may be recruited from random peptide libraries displayed on filamentous phage. In this study, we selected from two phage peptide libraries phage clones displaying peptides capable of specific and strong binding to the L. monocytogenes cell surface. The ability of isolated phage clones to interact specifically with L. monocytogenes was demonstrated using enzyme-linked immunosorbent assay (ELISA) and confirmed by co-precipitation assay. We also assessed the sensitivity of phage-bacteria binding by PCR on phage-captured Listeria cells, which could be detected at a concentration of 104 cells ml-1. In addition, as proof-of-concept, we tested the possibility of immobilizing the affinity-selected phages to a putative biosensor surface. The quality of phage deposition was monitored by ELISA and fluorescent microscopy. Phage-bacterial binding was confirmed by high power optical phase contrast microscopy. Overall, the results of this work validate the concept of affinity-selected recombinant filamentous phages as probes for detecting and monitoring bacterial agents under any conditions that warrant their recognition, including in food products.

  19. Crack detection by mobile photothermal probe

    Energy Technology Data Exchange (ETDEWEB)

    Besnard, R.; Le Blanc, A. [CEA Centre d`Etudes de Saclay, 91 - Gif-sur-Yvette (France). Dept. de Technologie des Materiaux; Bodnar, J.L.; Egee, M.; Menu, C. [Reims Univ., 51 (France); Sellier, J.Y. [Societe Intercontrole, 94 - Rungis (France)

    1993-12-31

    This paper deals with an industrial method for crack detection. The apparatus presented is based on a mobile photothermal probe. It can be used under different modes (sinusoidal, pulsed or scanned excitation). Moreover, the description of the device provided includes theoretical and experimental results. (TEC). 7 refs., 6 figs.

  20. A compact lightweight aerosol spectrometer probe (CLASP)

    NARCIS (Netherlands)

    Hill, M.K.; Brooks, B.J.; Norris, S.J.; Smith, M.H.; Brooks, I.M.; Leeuw, G. de

    2008-01-01

    The Compact Lightweight Aerosol Spectrometer Probe (CLASP) is an optical particle spectrometer capable of measuring size-resolved particle concentrations in 16 user-defined size bins spanning diameters in the range 0.24 < D < 18.5 μm at a rate of 10 Hz. The combination of its compact nature and ligh

  1. Probe and method for DNA detection

    Science.gov (United States)

    Yeh, Hsin-Chih; Werner, James Henry; Sharma, Jaswinder Kumar; Martinez, Jennifer Suzanne

    2013-07-02

    A hybridization probe containing two linear strands of DNA lights up upon hybridization to a target DNA using silver nanoclusters that have been templated onto one of the DNA strands. Hybridization induces proximity between the nanoclusters on one strand and an overhang on the other strand, which results in enhanced fluorescence emission from the nanoclusters.

  2. Magnetic-probe diagnostics for railgun plasma armatures

    Energy Technology Data Exchange (ETDEWEB)

    Parker, J.V.

    1989-06-01

    Magnetic probes were employed on the first plasma armature railgun experiments, and they have been used continuously since then for position determination and qualitative determination of the armature current. In the last few years, improvements in experimental technique and analysis have permitted more accurate measurements of the plasma-armature current distribution. This paper reviews the various probe configurations in use today and presents analytic approximations for the dependence of the probe signal on probe location and railgun geometry. Rail current and armature current probes are compared and contrasted with respect to resolution and accuracy. Further improvements in measurement accuracy are predicted for close-spaced magnetic-probe arrays.

  3. Probe for testing electrical properties of a test sample

    DEFF Research Database (Denmark)

    2012-01-01

    A probe for testing electrical properties of test samples includes a body having a probe arm defining proximal and distal ends, the probe arm extending from the body at the proximal end of the probe arm, whereby a first axis is defined by the proximal and the distal ends. The probe arm defines...... a geometry allowing flexible movement of the probe arm along the first axis and along a second axis perpendicular to the first axis, and along a third axis orthogonal to a plane defined by the first axis and the second axis....

  4. Semiconductor nanocrystal probes for biological applications and process for making and using such probes

    Science.gov (United States)

    Weiss, Shimon; Bruchez, Marcel; Alivisatos, Paul

    2012-10-16

    A semiconductor nanocrystal compound and probe are described. The compound is capable of linking to one or more affinity molecules. The compound comprises (1) one or more semiconductor nanocrystals capable of, in response to exposure to a first energy, providing a second energy, and (2) one or more linking agents, having a first portion linked to the one or more semiconductor nanocrystals and a second portion capable of linking to one or more affinity molecules. One or more semiconductor nanocrystal compounds are linked to one or more affinity molecules to form a semiconductor nanocrystal probe capable of bonding with one or more detectable substances in a material being analyzed, and capable of, in response to exposure to a first energy, providing a second energy. Also described are processes for respectively: making the semiconductor nanocrystal compound; making the semiconductor nanocrystal probe; and treating materials with the probe.

  5. Study of probe-sample distance for biomedical spectra measurement

    Directory of Open Access Journals (Sweden)

    Li Lei

    2011-11-01

    Full Text Available Abstract Background Fiber-based optical spectroscopy has been widely used for biomedical applications. However, the effect of probe-sample distance on the collection efficiency has not been well investigated. Method In this paper, we presented a theoretical model to maximize the illumination and collection efficiency in designing fiber optic probes for biomedical spectra measurement. This model was in general applicable to probes with single or multiple fibers at an arbitrary incident angle. In order to demonstrate the theory, a fluorescence spectrometer was used to measure the fluorescence of human finger skin at various probe-sample distances. The fluorescence spectrum and the total fluorescence intensity were recorded. Results The theoretical results show that for single fiber probes, contact measurement always provides the best results. While for multi-fiber probes, there is an optimal probe distance. When a 400- μm excitation fiber is used to deliver the light to the skin and another six 400- μm fibers surrounding the excitation fiber are used to collect the fluorescence signal, the experimental results show that human finger skin has very strong fluorescence between 475 nm and 700 nm under 450 nm excitation. The fluorescence intensity is heavily dependent on the probe-sample distance and there is an optimal probe distance. Conclusions We investigated a number of probe-sample configurations and found that contact measurement could be the primary choice for single-fiber probes, but was very inefficient for multi-fiber probes. There was an optimal probe-sample distance for multi-fiber probes. By carefully choosing the probe-sample distance, the collection efficiency could be enhanced by 5-10 times. Our experiments demonstrated that the experimental results of the probe-sample distance dependence of collection efficiency in multi-fiber probes were in general agreement with our theory.

  6. Periodontal Probe Improves Exams, Alleviates Pain

    Science.gov (United States)

    2008-01-01

    Dentists, comedian Bill Cosby memorably mused, tell you not to pick your teeth with any sharp metal object. Then you sit in their chair, and the first thing they grab is an iron hook!" Conventional periodontal probing is indeed invasive, uncomfortable for the patient, and the results can vary greatly between dentists and even for repeated measurements by the same dentist. It is a necessary procedure, though, as periodontal disease is the most common dental disease, involving the loss of teeth by the gradual destruction of ligaments that hold teeth in their sockets in the jawbone. The disease usually results from an increased concentration of bacteria in the pocket, or sulcus, between the gums and teeth. These bacteria produce acids and other byproducts, which enlarge the sulcus by eroding the gums and the periodontal ligaments. The sulcus normally has a depth of 1 to 2 millimeters, but in patients with early stages of periodontal disease, it has a depth of 3 to 5 millimeters. By measuring the depth of the sulcus, periodontists can have a good assessment of the disease s progress. Presently, there are no reliable clinical indicators of periodontal disease activity, and the best available diagnostic aid, periodontal probing, can only measure what has already been lost. A method for detecting small increments of periodontal ligament breakdown would permit earlier diagnosis and intervention with less costly and time-consuming therapy, while overcoming the problems associated with conventional probing. The painful, conventional method for probing may be destined for the archives of dental history, thanks to the development of ultrasound probing technologies. The roots of ultrasound probes are in an ultrasound-based time-of-flight technique routinely used to measure material thickness and length in the Nondestructive Evaluation Sciences Laboratory at Langley Research Center. The primary applications of that technology have been for corrosion detection and bolt tension

  7. Brane probes, toric geometry, and closed string tachyons

    Energy Technology Data Exchange (ETDEWEB)

    Sarkar, Tapobrata. E-mail: tapo@ictp.trieste.it

    2003-01-13

    We study non-supersymmetric orbifold singularities from the point of view of D-brane probes. We present a description of the decay of such singularities from considerations of the toric geometry of the probe branes.

  8. Brane Probes, Toric Geometry, and Closed String Tachyons

    OpenAIRE

    Sarkar, Tapobrata

    2002-01-01

    We study non-supersymmetric orbifold singularities from the point of view of D-brane probes. We present a description of the decay of such singularities from considerations of the toric geometry of the probe branes.

  9. Hollow fiber-optic Raman probes for small experimental animals

    Science.gov (United States)

    Katagiri, Takashi; Hattori, Yusuke; Suzuki, Toshiaki; Matsuura, Yuji; Sato, Hidetoshi

    2007-02-01

    Two types of hollow fiber-optic probes are developed to measure the in vivo Raman spectra of small animals. One is the minimized probe which is end-sealed with the micro-ball lens. The measured spectra reflect the information of the sample's sub-surface. This probe is used for the measurement of the esophagus and the stomach via an endoscope. The other probe is a confocal Raman probe which consists of a single fiber and a lens system. It is integrated into the handheld microscope. A simple and small multimodal probe is realized because the hollow optical fiber requires no optical filters. The performance of each probe is examined and the effectiveness of these probes for in vivo Raman spectroscopy is shown by animal tests.

  10. Overestimation of Mach number due to probe shadow

    Science.gov (United States)

    Gosselin, J. J.; Thakur, S. C.; Sears, S. H.; McKee, J. S.; Scime, E. E.; Tynan, G. R.

    2016-07-01

    Comparisons of the plasma ion flow speed measurements from Mach probes and laser induced fluorescence were performed in the Controlled Shear Decorrelation Experiment. We show the presence of the probe causes a low density geometric shadow downstream of the probe that affects the current density collected by the probe in collisional plasmas if the ion-neutral mean free path is shorter than the probe shadow length, Lg = w2 Vdrift/D⊥, resulting in erroneous Mach numbers. We then present a simple correction term that provides the corrected Mach number from probe data when the sound speed, ion-neutral mean free path, and perpendicular diffusion coefficient of the plasma are known. The probe shadow effect must be taken into account whenever the ion-neutral mean free path is on the order of the probe shadow length in linear devices and the open-field line region of fusion devices.

  11. Test probe for surface mounted leadless chip carrier

    Science.gov (United States)

    Meyer, Kerry L.; Topolewski, John

    1989-05-23

    A test probe for a surface mounted leadless chip carrier is disclosed. The probed includes specially designed connector pins which allow size reductions in the probe. A thermoplastic housing provides spring action to ensure good mechanical and electrical contact between the pins and the contact strips of a leadless chip carrier. Other features include flexible wires molded into the housing and two different types of pins alternately placed in the housing. These features allow fabrication of a smaller and simpler test probe.

  12. Novel Probes of Gravity and Dark Energy

    CERN Document Server

    Jain, Bhuvnesh; Thompson, Rodger; Upadhye, Amol; Battat, James; Brax, Philippe; Davis, Anne-Christine; de Rham, Claudia; Dodelson, Scott; Erickcek, Adrienne; Gabadadze, Gregory; Hu, Wayne; Hui, Lam; Huterer, Dragan; Kamionkowski, Marc; Khoury, Justin; Koyama, Kazuya; Li, Baojui; Linder, Eric; Schmidt, Fabian; Scoccimarro, Roman; Starkman, Glenn; Stubbs, Chris; Takada, Masahiro; Tolley, Andrew; Trodden, Mark; Uzan, Jean-Philippe; Vikram, Vinu; Weltman, Amanda; Wyman, Mark; Zaritsky, Dennis; Zhao, Gongbo

    2013-01-01

    The discovery of cosmic acceleration has stimulated theorists to consider dark energy or modifications to Einstein's General Relativity as possible explanations. The last decade has seen advances in theories that go beyond smooth dark energy -- modified gravity and interactions of dark energy. While the theoretical terrain is being actively explored, the generic presence of fifth forces and dark sector couplings suggests a set of distinct observational signatures. This report focuses on observations that differ from the conventional probes that map the expansion history or large-scale structure. Examples of such novel probes are: detection of scalar fields via lab experiments, tests of modified gravity using stars and galaxies in the nearby universe, comparison of lensing and dynamical masses of galaxies and clusters, and the measurements of fundamental constants at high redshift. The observational expertise involved is very broad as it spans laboratory experiments, high resolution astronomical imaging and sp...

  13. Probing complex RNA structures by mechanical force

    CERN Document Server

    Harlepp, S; Robert, J; Leger, J F; Xayaphoummine, A; Isambert, H; Chatenay, D

    2003-01-01

    RNA secondary structures of increasing complexity are probed combining single molecule stretching experiments and stochastic unfolding/refolding simulations. We find that force-induced unfolding pathways cannot usually be interpretated by solely invoking successive openings of native helices. Indeed, typical force-extension responses of complex RNA molecules are largely shaped by stretching-induced, long-lived intermediates including non-native helices. This is first shown for a set of generic structural motifs found in larger RNA structures, and then for Escherichia coli's 1540-base long 16S ribosomal RNA, which exhibits a surprisingly well-structured and reproducible unfolding pathway under mechanical stretching. Using out-of-equilibrium stochastic simulations, we demonstrate that these experimental results reflect the slow relaxation of RNA structural rearrangements. Hence, micromanipulations of single RNA molecules probe both their native structures and long-lived intermediates, so-called "kinetic traps",...

  14. Magnetically modulated fluorescent probes in turbid media

    CERN Document Server

    Yang,; Chen, Hongyu; Anker, Jeffrey N

    2010-01-01

    Magnetically modulated optical nanoprobes (MagMOONs) were used to detect and distinguish probe fluorescence from autofluorescent backgrounds in turbid media. MagMOONs are micro/nano-sized particles with magnetically controlled orientation and orientation-dependent fluorescence. These probes blink when they rotate in response to rotating external magnetic fields. This blinking signal can be separated from backgrounds enabling spectrochemical sensing in media with strong autofluorescence. We explore the effect of scattering on MagMOON fluorescence. Turbid media reduce the modulated MagMOON signal due to a combination of attenuation of fluorescence signal and reduction in contrast between "On" and "Off" states. The blinking MagMOON fluorescence spectrum can be detected in turbid non-dairy creamer solution with extinction 2.0, and through 9 mm of chicken breast tissue, suggesting that whole mouse imaging is feasible by using this strategy.

  15. Quasars as probes of cosmological reionization

    CERN Document Server

    Mortlock, Daniel J

    2015-01-01

    Quasars are the most luminous non-transient sources in the epoch of cosmological reionization (i.e., which ended a billion years after the Big Bang, corresponding to a redshift of z ~ 5), and are powerful probes of the inter-galactic medium at that time. This review covers current efforts to identify high-redshift quasars and how they have been used to constrain the reionization history. This includes a full description of the various processes by which neutral hydrogen atoms can absorb/scatter ultraviolet photons, and which lead to the Gunn-Peterson effect, dark gap and dark pixel analyses, quasar near zones and damping wing absorption. Finally, the future prospects for using quasars as probes of reionization are described.

  16. Molecular Probes for Thermometry in Microfluidic Devices

    Science.gov (United States)

    Gosse, Charlie; Bergaud, Christian; Löw, Peter

    The temperature is an important parameter with regard to chemical reactivity. It is therefore essential to ensure good thermal control within microsystems designed to carry out biological analysis. We begin by reviewing temperature measurement in the context of the lab-on-a-chip, and outlining the various generic strategies available. We then turnmore specifically to luminescentmolecular probes.We shall show that they all exploit the effect of temperature on a chemical reaction (in the broad sense of the term). More precisely, these probes can be divided in three main categories depending on whether one relies on a phase transition, the modification of a reaction rate, or a shift in an equilibrium. We shall also discuss the main experimental strategies used to transform the image obtained by fluorescence microscopy into a thermal map. Finally, we shall extend the discussion to a few other spectroscopic techniques and examine the prospects for this particular area of microfluidics.

  17. Protease-activated quantum dot probes

    International Nuclear Information System (INIS)

    We have developed a novel nanoparticulate luminescent probe with inherent signal amplification upon interaction with a targeted proteolytic enzyme. This construct may be useful for imaging in cancer detection and diagnosis. In this system, quantum dots (QDs) are bound to gold nanoparticles (AuNPs) via a proteolytically degradable peptide sequence to non-radiatively suppress luminescence. A 71% reduction in luminescence was achieved with conjugation of AuNPs to QDs. Release of AuNPs by peptide cleavage restores radiative QD photoluminescence. Initial studies observed a 52% rise in luminescence over 47 h of exposure to 0.2 mg/mL collagenase. These probes can be customized for targeted degradation simply by changing the sequence of the peptide linker

  18. Micro- and nanodevices integrated with biomolecular probes

    Science.gov (United States)

    Alapan, Yunus; Icoz, Kutay; Gurkan, Umut A.

    2016-01-01

    Understanding how biomolecules, proteins and cells interact with their surroundings and other biological entities has become the fundamental design criterion for most biomedical micro- and nanodevices. Advances in biology, medicine, and nanofabrication technologies complement each other and allow us to engineer new tools based on biomolecules utilized as probes. Engineered micro/nanosystems and biomolecules in nature have remarkably robust compatibility in terms of function, size, and physical properties. This article presents the state of the art in micro- and nanoscale devices designed and fabricated with biomolecular probes as their vital constituents. General design and fabrication concepts are presented and three major platform technologies are highlighted: microcantilevers, micro/nanopillars, and microfluidics. Overview of each technology, typical fabrication details, and application areas are presented by emphasizing significant achievements, current challenges, and future opportunities. PMID:26363089

  19. A coumarin-based colorimetric fluorescent probe for hydrogen sulfide

    Indian Academy of Sciences (India)

    Yanqiu Yang; Yu Liu; Liang Yang; Jun Liu; Kun Li; Shunzhong Luo

    2015-03-01

    A coumarin-based fluorescent probe for selective detection of hydrogen sulfide (H2S) is presented. This `off–on’ probe exhibited high selectivity towards H2S in aqueous solution with a detection limit of 30 nM. Notably, because of its dual nucleophilicity, the probe could avoid the interference of thiols and other sulfur containing compounds.

  20. Wideband scalable probe for Spherical Near-Field Antenna measurements

    DEFF Research Database (Denmark)

    Kim, Oleksiy S.; Pivnenko, Sergey; Breinbjerg, Olav

    2011-01-01

    The paper presents a design of an open-boundary quad-ridged horn to be used as a wideband scalable dual-linearly polarized probe for spherical near-field antenna measurements. With a new higher-order probe correction technique developed at the Technical University of Denmark, the probe will enabl...

  1. Data Communication PC/NaI-borehole probe (Hardware & Software)

    DEFF Research Database (Denmark)

    Madsen, Peter Buch

    Development of new hard- & software to a NaI borehole probe on a PC. Save data from the probe each 10'th sec, handle the data from the probe and make calculations every 10'th sec and show the results on the monitor....

  2. Calibrated cylindrical Mach probe in a plasma wind tunnel

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, X.; Dandurand, D.; Gray, T.; Brown, M. R. [Department of Physics and Astronomy, Center for Magnetic Self Organization, Swarthmore College, Swarthmore, Pennsylvania 19081-1397 (United States); Lukin, V. S. [Space Science Division, Naval Research Laboratory, Washington, DC 20375 (United States)

    2011-03-15

    A simple cylindrical Mach probe is described along with an independent calibration procedure in a magnetized plasma wind tunnel. A particle orbit calculation corroborates our model. The probe operates in the weakly magnetized regime in which probe dimension and ion orbit are of the same scale. Analytical and simulation models are favorably compared with experimental calibration.

  3. Modular design of AFM probe with sputtered silicon tip

    DEFF Research Database (Denmark)

    Rasmussen, Peter; Thaysen, Jacob; Bouwstra, Siebe;

    2001-01-01

    of the thin films constituting the cantilever. The AFM probe has an integrated tip made of a thick sputtered silicon layer, which is deposited after the probe has been defined and just before the cantilevers are released. The tips are so-called rocket tips made by reactive ion etching. We present probes...

  4. 21 CFR 886.1670 - Ophthalmic isotope uptake probe.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ophthalmic isotope uptake probe. 886.1670 Section... (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1670 Ophthalmic isotope uptake probe. (a) Identification. An ophthalmic isotope uptake probe is an AC-powered device intended to...

  5. The response of electrostatic probes via the λ-function

    DEFF Research Database (Denmark)

    Rerup, T.O.; Crichton, George C; McAllister, Iain Wilson

    1994-01-01

    The response of an electrostatic probe is examined with reference to a planar spacer. The study involves the numerical calculation of the probe λ-function, from which response-related characteristic parameters can be derived. These parameters enable the probe detection sensitivity and spatial...

  6. Response of electrostatic probes to eccentric charge distributions

    DEFF Research Database (Denmark)

    Johansson, Torben; McAllister, Iain Wilson

    2001-01-01

    The response of an electrostatic probe mounted in an electrode is examined with reference to eccentric charge distributions. The study involves using the probe λ function to derive a characteristic parameter. This parameter enables the response of the probe to different degrees of eccentricity to...

  7. Hall probes: physics and application to magnetometry

    OpenAIRE

    Sanfilippo, S.

    2011-01-01

    This lecture aims to present an overview of the properties of Hall effect devices. Descriptions of the Hall phenomenon, a review of the Hall effect device characteristics and of the various types of probes are presented. Particular attention is paid to the recent development of three-axis sensors and the related techniques to cancel the offsets and the planar Hall effect. The lecture introduces the delicate problem of the calibration of a three-dimensional sensor and ends with a section devot...

  8. Scanned probe characterization of semiconductor nanostructures

    OpenAIRE

    Law, James Jeremy MacDonald

    2009-01-01

    Advances in the synthesis of materials and device structures have accentuated the need to understand nanoscale electronic structure and its implications. Scanning probe microscopy offers a rich variety of highly spatially accurate techniques that can further our understanding of the interactions that occur in nanoscale semiconductor materials and devices. The promising nitride semiconductor materials system suffers from perturbations in local electronic structure due to crystallographic defec...

  9. Probing halo molecules with nonresonant light

    CERN Document Server

    Lemeshko, Mikhail

    2009-01-01

    We show that halo molecules can be probed by "shaking" in a pulsed nonresonant laser field. The field introduces a centrifugal term which expels the highest vibrational level from the potential that binds it. Our numerical simulations as well as an analytic model applied to the Rb$_2$ and KRb Feshbach molecules indicate that shaking by feasible laser pulses can be used to accurately recover the square of the vibrational wavefunction and, by inversion, also the molecular potential.

  10. Probing Strongly Coupled Chameleons with Slow Neutrons

    OpenAIRE

    Brax, Philippe; Pignol, Guillaume; Roulier, Damien

    2013-01-01

    We consider different methods to probe chameleons with slow neutrons. Chameleon modify the potential of bouncing neutrons over a flat mirror in the terrestrial gravitational field. This induces a shift in the energy levels of the neutrons which could be detected in current experiments like GRANIT. Chameleons between parallel plates have a field profile which is bubble-like and which would modify the phase of neutrons in interferometric experiments. We show that this new method of detection is...

  11. Fireside corrosion probes for fossil fuel combustion

    Energy Technology Data Exchange (ETDEWEB)

    Covino, B.S., Jr.; Bullard, S.J.; Ziomek-Moroz, M.; Holcomb, G.R.; Eden, D.A. (Intercorr International, Houston, TX)

    2006-03-01

    Electrochemical corrosion rate probes have been constructed and tested along with mass loss coupons in environments consisting of N2/O2/CO2/SO2 plus water vapor. Temperatures ranged from 450° to 700°C. Results show that electrochemical corrosion rates for ash-covered mild steel are a function of time, temperature, and gaseous environment. Correlation between the electrochemical and mass loss corrosion rates was poor.

  12. Ultraspecific probes for high throughput HLA typing

    Directory of Open Access Journals (Sweden)

    Eggers Rick

    2009-02-01

    Full Text Available Abstract Background The variations within an individual's HLA (Human Leukocyte Antigen genes have been linked to many immunological events, e.g. susceptibility to disease, response to vaccines, and the success of blood, tissue, and organ transplants. Although the microarray format has the potential to achieve high-resolution typing, this has yet to be attained due to inefficiencies of current probe design strategies. Results We present a novel three-step approach for the design of high-throughput microarray assays for HLA typing. This approach first selects sequences containing the SNPs present in all alleles of the locus of interest and next calculates the number of base changes necessary to convert a candidate probe sequences to the closest subsequence within the set of sequences that are likely to be present in the sample including the remainder of the human genome in order to identify those candidate probes which are "ultraspecific" for the allele of interest. Due to the high specificity of these sequences, it is possible that preliminary steps such as PCR amplification are no longer necessary. Lastly, the minimum number of these ultraspecific probes is selected such that the highest resolution typing can be achieved for the minimal cost of production. As an example, an array was designed and in silico results were obtained for typing of the HLA-B locus. Conclusion The assay presented here provides a higher resolution than has previously been developed and includes more alleles than previously considered. Based upon the in silico and preliminary experimental results, we believe that the proposed approach can be readily applied to any highly polymorphic gene system.

  13. Probing plasmonic nanostructures by photons and electrons

    DEFF Research Database (Denmark)

    Kneipp, Katrin; Kneipp, Harald; Kneipp, Janina

    2015-01-01

    We discuss recent developments for studying plasmonic metal nanostructures. Exploiting photons and electrons opens up new capabilities to probe the complete plasmon spectrum including bright and dark modes and related local optical fields at subnanometer spatial resolution. This comprehensive cha...... characterization of plasmonic properties of metal nanostructures provides new basic insight into the fundamental physics of "surface enhanced" spectroscopy in hottest hot spots and enables us to optimize plasmon supported processes and devices....

  14. Probing Deconfinement with Polyakov Loop Susceptibilities

    OpenAIRE

    Lo, Pok Man; Friman, Bengt; Kaczmarek, Olaf; Redlich, Krzysztof; Sasaki, Chihiro

    2013-01-01

    The susceptibilities of the real and imaginary parts, as well as of the modulus of the Polyakov loop, are computed in SU(3) lattice gauge theory. We show that the ratios of these susceptibilities are excellent probes of the deconfinement transition, independent of the renormalization of the Polyakov loop and only weakly dependent on the system size. The ratios are almost temperature independent above and below the transition and exhibit a discontinuity at the transition temperature. This char...

  15. A self-assembled microlensing rotational probe

    OpenAIRE

    Brody, James P; Quake, Stephen R.

    1999-01-01

    A technique to measure microscopic rotational motion is presented. When a small fluorescent polystyrene microsphere is attached to a larger polystyrene microsphere, the larger sphere acts as a lens for the smaller microsphere and provides an optical signal that is a strong function of the azimuthal angle. We demonstrate the technique by measuring the rotational diffusion constant of the microsphere in solutions of varying viscosity and discuss the feasibility of using this probe to measure ro...

  16. Bacteriophage based probes for pathogen detection.

    Science.gov (United States)

    Singh, Amit; Arutyunov, Denis; Szymanski, Christine M; Evoy, Stephane

    2012-08-01

    Rapid and specific detection of pathogenic bacteria is important for the proper treatment, containment and prevention of human, animal and plant diseases. Identifying unique biological probes to achieve a high degree of specificity and minimize false positives has therefore garnered much interest in recent years. Bacteriophages are obligate intracellular parasites that subvert bacterial cell resources for their own multiplication and production of disseminative new virions, which repeat the cycle by binding specifically to the host surface receptors and injecting genetic material into the bacterial cells. The precision of host recognition in phages is imparted by the receptor binding proteins (RBPs) that are often located in the tail-spike or tail fiber protein assemblies of the virions. Phage host recognition specificity has been traditionally exploited for bacterial typing using laborious and time consuming bacterial growth assays. At the same time this feature makes phage virions or RBPs an excellent choice for the development of probes capable of selectively capturing bacteria on solid surfaces with subsequent quick and automatic detection of the binding event. This review focuses on the description of pathogen detection approaches based on immobilized phage virions as well as pure recombinant RBPs. Specific advantages of RBP-based molecular probes are also discussed.

  17. Doubling strong lensing as a cosmological probe

    Science.gov (United States)

    Linder, Eric V.

    2016-10-01

    Strong gravitational lensing provides a geometric probe of cosmology in a unique manner through distance ratios involving the source and lens. This is well-known for the time delay distance derived from measured delays between lightcurves of the images of variable sources such as quasars. Recently, double source plane lens systems involving two constant sources lensed by the same foreground lens have been proposed as another probe, involving a different ratio of distances measured from the image positions and fairly insensitive to the lens modeling. Here we demonstrate that these two different sets of strong lensing distance ratios have strong complementarity in cosmological leverage. Unlike other probes, the double source distance ratio is actually more sensitive to the dark energy equation of state parameters w0 and wa than to the matter density Ωm, for low redshift lenses. Adding double source distance ratio measurements can improve the dark energy figure of merit by 40% for a sample of fewer than 100 low redshift systems, or even better for the optimal redshift distribution we derive.

  18. Probing New Physics with Isotope Shift Spectroscopy

    CERN Document Server

    Delaunay, Cédric

    2016-01-01

    We investigate the potential to probe physics beyond the Standard Model with isotope shift measurements of optical atomic clock transitions. We first derive the reach for generic new physics above the GeV scale at the effective field theory level, as well as estimate the limits on possible new spin-independent forces mediated by sub-GeV states coupled to electrons and neutrons. We also study the weak force and show that isotope shifts could provide strong constraints on the $Z^0$ couplings to valence quarks, which complement precision observables at LEP and atomic parity violation experiments. Finally, motivated by recent experimental hints of a new 750 GeV resonance in diphotons, we also consider the potential to probe its parity-preserving couplings to electrons, quarks and gluons with this method. In particular, combining the diphoton signal with indirect constraints from $g_e-2$ and isotope shifts in Ytterbium allows to probe the resonance coupling to electrons with unprecedented precision.

  19. Antenna Near-Field Probe Station Scanner

    Science.gov (United States)

    Zaman, Afroz J. (Inventor); Lee, Richard Q. (Inventor); Darby, William G. (Inventor); Barr, Philip J. (Inventor); Lambert, Kevin M (Inventor); Miranda, Felix A. (Inventor)

    2011-01-01

    A miniaturized antenna system is characterized non-destructively through the use of a scanner that measures its near-field radiated power performance. When taking measurements, the scanner can be moved linearly along the x, y and z axis, as well as rotationally relative to the antenna. The data obtained from the characterization are processed to determine the far-field properties of the system and to optimize the system. Each antenna is excited using a probe station system while a scanning probe scans the space above the antenna to measure the near field signals. Upon completion of the scan, the near-field patterns are transformed into far-field patterns. Along with taking data, this system also allows for extensive graphing and analysis of both the near-field and far-field data. The details of the probe station as well as the procedures for setting up a test, conducting a test, and analyzing the resulting data are also described.

  20. A quantum spin-probe molecular microscope

    Science.gov (United States)

    Perunicic, V. S.; Hill, C. D.; Hall, L. T.; Hollenberg, L.C.L.

    2016-01-01

    Imaging the atomic structure of a single biomolecule is an important challenge in the physical biosciences. Whilst existing techniques all rely on averaging over large ensembles of molecules, the single-molecule realm remains unsolved. Here we present a protocol for 3D magnetic resonance imaging of a single molecule using a quantum spin probe acting simultaneously as the magnetic resonance sensor and source of magnetic field gradient. Signals corresponding to specific regions of the molecule's nuclear spin density are encoded on the quantum state of the probe, which is used to produce a 3D image of the molecular structure. Quantum simulations of the protocol applied to the rapamycin molecule (C51H79NO13) show that the hydrogen and carbon substructure can be imaged at the angstrom level using current spin-probe technology. With prospects for scaling to large molecules and/or fast dynamic conformation mapping using spin labels, this method provides a realistic pathway for single-molecule microscopy. PMID:27725630

  1. Lysosomal Targeting with Stable and Sensitive Fluorescent Probes (Superior LysoProbes): Applications for Lysosome Labeling and Tracking during Apoptosis

    OpenAIRE

    Xin Chen; Yue Bi; Tianyang Wang; Pengfei Li; Xin Yan; Shanshan Hou; Catherine E. Bammert; Jingfang Ju; K. Michael Gibson; Pavan, William J.; Lanrong Bi

    2015-01-01

    Intracellular pH plays an important role in the response to cancer invasion. We have designed and synthesized a series of new fluorescent probes (Superior LysoProbes) with the capacity to label acidic organelles and monitor lysosomal pH. Unlike commercially available fluorescent dyes, Superior LysoProbes are lysosome-specific and are highly stable. The use of Superior LysoProbes facilitates the direct visualization of the lysosomal response to lobaplatin elicited in human chloangiocarcinoma (...

  2. Modeling the Insertion Mechanics of Flexible Neural Probes Coated with Sacrificial Polymers for Optimizing Probe Design

    Directory of Open Access Journals (Sweden)

    Sagar Singh

    2016-03-01

    Full Text Available Single-unit recording neural probes have significant advantages towards improving signal-to-noise ratio and specificity for signal acquisition in brain-to-computer interface devices. Long-term effectiveness is unfortunately limited by the chronic injury response, which has been linked to the mechanical mismatch between rigid probes and compliant brain tissue. Small, flexible microelectrodes may overcome this limitation, but insertion of these probes without buckling requires supporting elements such as a stiff coating with a biodegradable polymer. For these coated probes, there is a design trade-off between the potential for successful insertion into brain tissue and the degree of trauma generated by the insertion. The objective of this study was to develop and validate a finite element model (FEM to simulate insertion of coated neural probes of varying dimensions and material properties into brain tissue. Simulations were performed to predict the buckling and insertion forces during insertion of coated probes into a tissue phantom with material properties of brain. The simulations were validated with parallel experimental studies where probes were inserted into agarose tissue phantom, ex vivo chick embryonic brain tissue, and ex vivo rat brain tissue. Experiments were performed with uncoated copper wire and both uncoated and coated SU-8 photoresist and Parylene C probes. Model predictions were found to strongly agree with experimental results (<10% error. The ratio of the predicted buckling force-to-predicted insertion force, where a value greater than one would ideally be expected to result in successful insertion, was plotted against the actual success rate from experiments. A sigmoidal relationship was observed, with a ratio of 1.35 corresponding to equal probability of insertion and failure, and a ratio of 3.5 corresponding to a 100% success rate. This ratio was dubbed the “safety factor”, as it indicated the degree to which the coating

  3. Encouragement from Jupiter for Europe's Titan Probe

    Science.gov (United States)

    1996-04-01

    Huygens will transmit scientific information for 150 minutes, from the outer reaches of Titan's cold atmosphere and all the way down to its enigmatic surface. For comparison, the Jupiter Probe radioed scientific data for 58 minutes as it descended about 200 kilometres into the outer part of the atmosphere of the giant planet. The parachutes controlling various stages of Huygens' descent will rely upon a system for deployment designed and developed in Europe that is nevertheless similar to that used by the Jupiter Probe. The elaborate sequence of operations in Huygens worked perfectly during a dramatic drop test from a stratospheric balloon over Sweden in May 1995, which approximated as closely as possible to events on Titan. The performance of the American Probe at Jupiter renews the European engineers' confidence in their own descent control system, and also in the lithium sulphur-dioxide batteries which were chosen to power both Probes. "The systems work after long storage in space," comments Hamid Hassan, ESA's Project Manager for Huygens. "Huygens will spend seven years travelling to Saturn's vicinity aboard the Cassini Orbiter. The Jupiter Probe was a passenger in Galileo for six years before its release, so there is no reason to doubt that Huygens will work just as well." Huygens will enter the outer atmosphere of Titan at 20,000 kilometres per hour. A heat shield 2.7 metres in diameter will withstand the friction and slow the Probe to a speed at which parachutes can be deployed. The size of the parachute for the main phase of the descent is chosen to allow Huygens to reach the surface in about 2 hours. The batteries powering Huygens will last for about 21/2 hours. Prepared for surprises A different perspective on the Jupiter Probe comes from Jean-Pierre Lebreton, ESA's Project Scientist for Huygens. The results contradicted many preconceptions of the Galileo scientists, particularly about the abundance of water and the structure of cloud layers. Arguments

  4. Electrical Conductivity Studies on Individual Conjugated Polymer Nanowires: Two-Probe and Four-Probe Results

    Directory of Open Access Journals (Sweden)

    Duvail JeanLuc

    2009-01-01

    Full Text Available Abstract Two- and four-probe electrical measurements on individual conjugated polymer nanowires with different diameters ranging from 20 to 190 nm have been performed to study their conductivity and nanocontact resistance. The two-probe results reveal that all the measured polymer nanowires with different diameters are semiconducting. However, the four-probe results show that the measured polymer nanowires with diameters of 190, 95–100, 35–40 and 20–25 nm are lying in the insulating, critical, metallic and insulting regimes of metal–insulator transition, respectively. The 35–40 nm nanowire displays a metal–insulator transition at around 35 K. In addition, it was found that the nanocontact resistance is in the magnitude of 104Ω at room temperature, which is comparable to the intrinsic resistance of the nanowires. These results demonstrate that four-probe electrical measurement is necessary to explore the intrinsic electronic transport properties of isolated nanowires, especially in the case of metallic nanowires, because the metallic nature of the measured nanowires may be coved by the nanocontact resistance that cannot be excluded by a two-probe technique.

  5. Probe design for expression arrays using OligoWiz

    DEFF Research Database (Denmark)

    Wernersson, Rasmus

    2014-01-01

    Since all measurements from a DNA microarray is dependant on the probes used, a good choice of probes is of vital importa nce when designing custom micro-arrays. This chapter describes how to de sign expression arrays using the “ OligoWiz ” software suite. The general desired features of good...... probes and the issues which probe design must address are introduced and a conceptual (rather than mathematical) description of how OligoWiz scores the quality of th e potential probes is presented. This is followed by a detailed step-by-step guide to designing expression arrays with OligoWiz....

  6. The Behaviour of Probes in Transonic Flowfields of Turbomachinery

    OpenAIRE

    Kost, Friedrich

    2009-01-01

    It is known that a constraint exists for probes in transonic flow which leads to an insensitivity to static pressure at Mach number unity. Nearby that Mach number different types of probes are affected more or less by the reduced sensitivity to static pressure or Mach number. In transonic flow the combined disturbance of probe head and stem extends the insensitivity range up to a Mach number of 1.3. Some probes even show a non- monotonic relation of probe coefficient to Mach nu...

  7. Diagnostic PCR: Comparative sensitivity of four probe chemistries

    DEFF Research Database (Denmark)

    Josefsen, Mathilde Hartmann; Löfström, Charlotta; Sommer, Helle Mølgaard;

    2009-01-01

    Three probe chemistries: locked nucleic acid (LNA), minor groove binder (MGB) and Scorpion were compared with a TaqMan probe in a validated real-time PCR assay for detection of food-borne thermotolerant Campylobacter. The LNA probe produced significantly lower Ct-values and a higher proportion of...... positive PCR responses analyzing less than 150 DNA copies than the TaqMan probe. Choice of probe chemistry clearly has an impact on the sensitivity of PCR assays, and should be considered in an optimization strategy....

  8. Differential capacitance probe for process control involving aqueous dielectric fluids

    Science.gov (United States)

    Svoboda, John M.; Morrison, John L.

    2002-10-08

    A differential capacitance probe device for process control involving aqueous dielectric fluids is disclosed. The device contains a pair of matched capacitor probes configured in parallel, one immersed in a sealed container of reference fluid, and the other immersed in the process fluid. The sealed container holding the reference fluid is also immersed in the process fluid, hence both probes are operated at the same temperature. Signal conditioning measures the difference in capacitance between the reference probe and the process probe. The resulting signal is a control error signal that can be used to control the process.

  9. Shared probe design and existing microarray reanalysis using PICKY

    Directory of Open Access Journals (Sweden)

    Chou Hui-Hsien

    2010-04-01

    Full Text Available Abstract Background Large genomes contain families of highly similar genes that cannot be individually identified by microarray probes. This limitation is due to thermodynamic restrictions and cannot be resolved by any computational method. Since gene annotations are updated more frequently than microarrays, another common issue facing microarray users is that existing microarrays must be routinely reanalyzed to determine probes that are still useful with respect to the updated annotations. Results PICKY 2.0 can design shared probes for sets of genes that cannot be individually identified using unique probes. PICKY 2.0 uses novel algorithms to track sharable regions among genes and to strictly distinguish them from other highly similar but nontarget regions during thermodynamic comparisons. Therefore, PICKY does not sacrifice the quality of shared probes when choosing them. The latest PICKY 2.1 includes the new capability to reanalyze existing microarray probes against updated gene sets to determine probes that are still valid to use. In addition, more precise nonlinear salt effect estimates and other improvements are added, making PICKY 2.1 more versatile to microarray users. Conclusions Shared probes allow expressed gene family members to be detected; this capability is generally more desirable than not knowing anything about these genes. Shared probes also enable the design of cross-genome microarrays, which facilitate multiple species identification in environmental samples. The new nonlinear salt effect calculation significantly increases the precision of probes at a lower buffer salt concentration, and the probe reanalysis function improves existing microarray result interpretations.

  10. Design and analysis of mismatch probes for long oligonucleotide microarrays

    Energy Technology Data Exchange (ETDEWEB)

    Deng, Ye; He, Zhili; Van Nostrand, Joy D.; Zhou, Jizhong

    2008-08-15

    Nonspecific hybridization is currently a major concern with microarray technology. One of most effective approaches to estimating nonspecific hybridizations in oligonucleotide microarrays is the utilization of mismatch probes; however, this approach has not been used for longer oligonucleotide probes. Here, an oligonucleotide microarray was constructed to evaluate and optimize parameters for 50-mer mismatch probe design. A perfect match (PM) and 28 mismatch (MM) probes were designed for each of ten target genes selected from three microorganisms. The microarrays were hybridized with synthesized complementary oligonucleotide targets at different temperatures (e.g., 42, 45 and 50 C). In general, the probes with evenly distributed mismatches were more distinguishable than those with randomly distributed mismatches. MM probes with 3, 4 and 5 mismatched nucleotides were differentiated for 50-mer oligonucleotide probes hybridized at 50, 45 and 42 C, respectively. Based on the experimental data generated from this study, a modified positional dependent nearest neighbor (MPDNN) model was constructed to adjust the thermodynamic parameters of matched and mismatched dimer nucleotides in the microarray environment. The MM probes with four flexible positional mismatches were designed using the newly established MPDNN model and the experimental results demonstrated that the redesigned MM probes could yield more consistent hybridizations. Conclusions: This study provides guidance on the design of MM probes for long oligonucleotides (e.g., 50 mers). The novel MPDNN model has improved the consistency for long MM probes, and this modeling method can potentially be used for the prediction of oligonucleotide microarray hybridizations.

  11. Computational comparative study of microwave probes for plasma density measurement

    Science.gov (United States)

    Kim, D. W.; You, S. J.; Kim, J. H.; Chang, H. Y.; Oh, W. Y.

    2016-06-01

    A microwave probe is known to be a suitable method to measure plasma density, even in the processing condition and is widely used in various environments of low-temperature processing plasmas. Various types of microwave probes have been researched and developed to measure the precise plasma density. Extensive research has been conducted to investigate each probes characteristic responding to the plasma parameters (plasma density, electron temperature, pressure, sheath width, and so forth) based on both experiments and simulations. However, a comparative study elucidating the relative characteristics of each probe has not been completed yet, despite the wide applications of the probes in processing plasma. We conduct a comparative study among the microwave probes using the numerical method of three-dimensional finite-difference time-domain simulation. In this study, the microwave probes are compared by investigating the precision of plasma density measurement under a comprehensive range of plasma parameters (plasma density, pressure, and sheath width).

  12. Microarray of DNA probes on carboxylate functional beads surface

    Institute of Scientific and Technical Information of China (English)

    黄承志; 李原芳; 黄新华; 范美坤

    2000-01-01

    The microarray of DNA probes with 5’ -NH2 and 5’ -Tex/3’ -NH2 modified terminus on 10 um carboxylate functional beads surface in the presence of 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide (EDC) is characterized in the preseni paper. it was found that the microarray capacity of DNA probes on the beads surface depends on the pH of the aqueous solution, the concentra-tion of DNA probe and the total surface area of the beads. On optimal conditions, the minimum distance of 20 mer single-stranded DNA probe microarrayed on beads surface is about 14 nm, while that of 20 mer double-stranded DNA probes is about 27 nm. If the probe length increases from 20 mer to 35 mer, its microarray density decreases correspondingly. Mechanism study shows that the binding mode of DNA probes on the beads surface is nearly parallel to the beads surface.

  13. Atmospheric Probe Model: Construction and Wind Tunnel Tests

    Science.gov (United States)

    Vogel, Jerald M.

    1998-01-01

    The material contained in this document represents a summary of the results of a low speed wind tunnel test program to determine the performance of an atmospheric probe at low speed. The probe configuration tested consists of a 2/3 scale model constructed from a combination of hard maple wood and aluminum stock. The model design includes approximately 130 surface static pressure taps. Additional hardware incorporated in the baseline model provides a mechanism for simulating external and internal trailing edge split flaps for probe flow control. Test matrix parameters include probe side slip angle, external/internal split flap deflection angle, and trip strip applications. Test output database includes surface pressure distributions on both inner and outer annular wings and probe center line velocity distributions from forward probe to aft probe locations.

  14. An improved fabrication method for carbon nanotube probe

    Institute of Scientific and Technical Information of China (English)

    XU Zong-wei; GUO Li-qiu; DONG Shen; ZHAO Qing-liang

    2008-01-01

    An improved arc discharge method is developed to fabricate the carbon nanotube probe.In this method,the silicon probe and the carbon nanotube were manipulated under an optical microscope.When the silicon probe and the carbon nanotube were very close,30-60 V dc or ac was applied between them,and the carbon nanotube was divided and attached to the end of the silicon probe.Comparing with the arc discharge method,the new method need not coat the silicon probe with metal in advance,which Can greatly reduce the fabrication difficulty and cost.The fabricated carbon nanotube probe exhibits the good property of hish aspect ratio and can reflect the true topography more accurately than the silicon probe.

  15. Sampling probe for microarray read out using electrospray mass spectrometry

    Science.gov (United States)

    Van Berkel, Gary J.

    2004-10-12

    An automated electrospray based sampling system and method for analysis obtains samples from surface array spots having analytes. The system includes at least one probe, the probe including an inlet for flowing at least one eluting solvent to respective ones of a plurality of spots and an outlet for directing the analyte away from the spots. An automatic positioning system is provided for translating the probe relative to the spots to permit sampling of any spot. An electrospray ion source having an input fluidicly connected to the probe receives the analyte and generates ions from the analyte. The ion source provides the generated ions to a structure for analysis to identify the analyte, preferably being a mass spectrometer. The probe can be a surface contact probe, where the probe forms an enclosing seal along the periphery of the array spot surface.

  16. Organo luminescent semiconductor nanocrystal probes for biological applications and process for making and using such probes

    Science.gov (United States)

    Weiss, Shimon; Bruchez, Jr., Marcel; Alivisatos, Paul

    2008-01-01

    A semiconductor nanocrystal compound is described capable of linking to an affinity molecule. The compound comprises (1) a semiconductor nanocrystal capable of emitting electromagnetic radiation and/or absorbing energy, and/or scattering or diffracting electromagnetic radiation--when excited by an electromagnetic radiation source or a particle beam; and (2) an affinity molecule linked to the semiconductor nanocrystal. The semiconductor nanocrystal is linked to an affinity molecule to form a semiconductor nanocrystal probe capable of bonding with a detectable substance. Exposure of the semiconductor nanocrystal to excitation energy will excite the semiconductor nanocrystal causing the emission of electromagnetic radiation. Further described are processes for respectively: making the luminescent semiconductor nanocrystal compound; making the semiconductor nanocrystal probe; and using the probe to determine the presence of a detectable substance in a material.

  17. UPS 2.0: unique probe selector for probe design and oligonucleotide microarrays at the pangenomic/ genomic level

    Directory of Open Access Journals (Sweden)

    Hsiung Chao A

    2010-12-01

    Full Text Available Abstract Background Nucleic acid hybridization is an extensively adopted principle in biomedical research, in which the performance of any hybridization-based method depends on the specificity of probes to their targets. To determine the optimal probe(s for detecting target(s from a sample cocktail, we developed a novel algorithm, which has been implemented into a web platform for probe designing. This probe design workflow is now upgraded to satisfy experiments that require a probe designing tool to take the increasing volume of sequence datasets. Results Algorithms and probe parameters applied in UPS 2.0 include GC content, the secondary structure, melting temperature (Tm, the stability of the probe-target duplex estimated by the thermodynamic model, sequence complexity, similarity of probes to non-target sequences, and other empirical parameters used in the laboratory. Several probe background options,Unique probe within a group,Unique probe in a specific Unigene set,Unique probe based onthe pangenomic level, and Unique Probe in the user-defined genome/transcriptome, are available to meet the scenarios that the experiments will be conducted. Parameters, such as salt concentration and the lower-bound Tm of probes, are available for users to optimize their probe design query. Output files are available for download on the result page. Probes designed by the UPS algorithm are suitable for generating microarrays, and the performance of UPS-designed probes has been validated by experiments. Conclusions The UPS 2.0 evaluates probe-to-target hybridization under a user-defined condition to ensure high-performance hybridization with minimal chance of non-specific binding at the pangenomic and genomic levels. The UPS algorithm mimics the target/non-target mixture in an experiment and is very useful in developing diagnostic kits and microarrays. The UPS 2.0 website has had more than 1,300 visits and 360,000 sequences performed the probe designing task

  18. Probing the PEDOT:PSS/cell interface with conductive colloidal probe AFM-SECM

    Science.gov (United States)

    Knittel, P.; Zhang, H.; Kranz, C.; Wallace, G. G.; Higgins, M. J.

    2016-02-01

    Conductive colloidal probe Atomic Force-Scanning Electrochemical Microscopy (AFM-SECM) is a new approach, which employs electrically insulated AFM probes except for a gold-coated colloid located at the end of the cantilever. Hence, force measurements can be performed while biasing the conductive colloid under physiological conditions. Moreover, such colloids can be modified by electrochemical polymerization resulting, e.g. in conductive polymer-coated spheres, which in addition may be loaded with specific dopants. In contrast to other AFM-based single cell force spectroscopy measurements, these probes allow adhesion measurements at the cell-biomaterial interface on multiple cells in a rapid manner while the properties of the polymer can be changed by applying a bias. In addition, spatially resolved electrochemical information e.g., oxygen reduction can be obtained simultaneously. Conductive colloid AFM-SECM probes modified with poly(3,4-ethylenedioxythiophene) doped with polystyrene sulfonate (PEDOT:PSS) are used for single cell force measurements in mouse fibroblasts and single cell interactions are investigated as a function of the applied potential.Conductive colloidal probe Atomic Force-Scanning Electrochemical Microscopy (AFM-SECM) is a new approach, which employs electrically insulated AFM probes except for a gold-coated colloid located at the end of the cantilever. Hence, force measurements can be performed while biasing the conductive colloid under physiological conditions. Moreover, such colloids can be modified by electrochemical polymerization resulting, e.g. in conductive polymer-coated spheres, which in addition may be loaded with specific dopants. In contrast to other AFM-based single cell force spectroscopy measurements, these probes allow adhesion measurements at the cell-biomaterial interface on multiple cells in a rapid manner while the properties of the polymer can be changed by applying a bias. In addition, spatially resolved electrochemical

  19. The D3-probe-D7 brane holographic fractional topological insulator

    CERN Document Server

    Kristjansen, Charlotte

    2016-01-01

    The D3-probe-D7 brane system, oriented so as to have 2+1-dimensional Poincare symmetry, is argued to be the holographic representation of a strongly correlated fractional topological insulator which exhibits a zero-field quantized Hall effect with half-units of Hall conductivity. The phase diagram of the system with charge density and external magnetic field is found and, as well as charge gapped quantum Hall states, it exhibits metallic and semi-metallic phases with interesting behaviours. The relationship of this to other models of fractional topological insulators is discussed.

  20. The Methodology of Probe Design with Better Resolution and Less Resistive Donut Probe to Achieve the Best Performance

    Institute of Scientific and Technical Information of China (English)

    Mohammad Ismail Talukder; Pepe Siy; Gregory Auner; Jinsheng Zhang

    2009-01-01

    Probes are the interface between microsystems and bio-cells. The ideal interface is one-to-one interface. Though various research groups have been able to establish some sort of interfaces after many years of research, they are very crude. Neurons are millions in numbers, whereas the prostheses successfully built so far have only a few hundred probes at best. Creating an ef-fective interface is still far away. Though we have micro-and nano-technologies, we couldn't build a prosthesis with an effective resolution. Main reasons behind it are the type of probe being used and the poor design of the probe. To address this problem, we developed a methodology to design a probe and an array of probes with better resolution and less resistive donut probe. This methodology helps us to design a probe optimizing all the parameters. We presented our methodology through a design that is capable of 70 pan penetration inside the tissue. The tissue heating by our designed probe is only 0.411℃. We also characterized the donut probe, which could be used by any research group to design a donut probe of their specific need.

  1. Quantitative microbial ecology through stable isotope probing.

    Science.gov (United States)

    Hungate, Bruce A; Mau, Rebecca L; Schwartz, Egbert; Caporaso, J Gregory; Dijkstra, Paul; van Gestel, Natasja; Koch, Benjamin J; Liu, Cindy M; McHugh, Theresa A; Marks, Jane C; Morrissey, Ember M; Price, Lance B

    2015-11-01

    Bacteria grow and transform elements at different rates, and as yet, quantifying this variation in the environment is difficult. Determining isotope enrichment with fine taxonomic resolution after exposure to isotope tracers could help, but there are few suitable techniques. We propose a modification to stable isotope probing (SIP) that enables the isotopic composition of DNA from individual bacterial taxa after exposure to isotope tracers to be determined. In our modification, after isopycnic centrifugation, DNA is collected in multiple density fractions, and each fraction is sequenced separately. Taxon-specific density curves are produced for labeled and nonlabeled treatments, from which the shift in density for each individual taxon in response to isotope labeling is calculated. Expressing each taxon's density shift relative to that taxon's density measured without isotope enrichment accounts for the influence of nucleic acid composition on density and isolates the influence of isotope tracer assimilation. The shift in density translates quantitatively to isotopic enrichment. Because this revision to SIP allows quantitative measurements of isotope enrichment, we propose to call it quantitative stable isotope probing (qSIP). We demonstrated qSIP using soil incubations, in which soil bacteria exhibited strong taxonomic variations in (18)O and (13)C composition after exposure to [(18)O]water or [(13)C]glucose. The addition of glucose increased the assimilation of (18)O into DNA from [(18)O]water. However, the increase in (18)O assimilation was greater than expected based on utilization of glucose-derived carbon alone, because the addition of glucose indirectly stimulated bacteria to utilize other substrates for growth. This example illustrates the benefit of a quantitative approach to stable isotope probing.

  2. Spacetime, spin and Gravity Probe B

    Science.gov (United States)

    Overduin, J. M.

    2015-11-01

    It is more important than ever to push experimental tests of gravitational theory to the limits of existing technology in both range and sensitivity. This brief review focuses on spin-based tests of general relativity and their implications for alternative, mostly non-metric theories of gravity motivated by the challenge of unification with the standard model of particle physics. The successful detection of geodetic precession and frame-dragging by Gravity Probe B places new constraints on a number of these theories, and increases our confidence in the theoretical mechanisms underpinning current ideas in astrophysics and cosmology.

  3. Iron-sulfide crystals in probe deposits

    DEFF Research Database (Denmark)

    Laursen, Karin; Frandsen, Flemming

    1998-01-01

    Iron-sulfides were observed in deposits collected on a probe inserted at the top of the furnace of a coal-fired power station in Denmark. The chemical composition of the iron-sulfides is equivalent to pyrrhotite (FeS). The pyrrhotites are present as crystals and, based on the shape of the crystals......: (1) impact of low viscous droplets of iron sulfide; and (2) sulfur diffusion. Previous research on the influence of pyrite on slagging focused on the decomposition of pyrite into pyrrhotite and especially on the oxidation stage of this product during impact on the heat transfer surfaces...

  4. Probing the Big Bang with LEP

    Science.gov (United States)

    Schramm, David N.

    1990-01-01

    It is shown that LEP probes the Big Bang in two significant ways: (1) nucleosynthesis, and (2) dark matter constraints. In the first case, LEP verifies the cosmological standard model prediction on the number of neutrino types, thus strengthening the conclusion that the cosmological baryon density is approximately 6 percent of the critical value. In the second case, LEP shows that the remaining non-baryonic cosmological matter must be somewhat more massive and/or more weakly interacting than the favorite non-baryonic dark matter candidates of a few years ago.

  5. Optical Excitation and Probing of Bottle Microresonators

    Science.gov (United States)

    Murugan, G. Senthil; Wilkinson, J. S.; Zervas, M. N.

    2010-11-01

    Fiber bottle microresonators supporting helical whispering gallery modes and exhibiting field maxima symmetrically located on either side of the neck of the bottle have been demonstrated. Channel dropping characteristics have been studied experimentally for the first time in this type of microresonator, using tapered excitation and probe fibers symmetrically placed on both sides of the bottle microresonator. Selective excitation on one side of the bottle microresonator leads to symmetrically located turning points and power localization on both sides of the bottle, leading to the potential to construct add-drop filters.

  6. Nanoscale microwave microscopy using shielded cantilever probes

    KAUST Repository

    Lai, Keji

    2011-04-21

    Quantitative dielectric and conductivity mapping in the nanoscale is highly desirable for many research disciplines, but difficult to achieve through conventional transport or established microscopy techniques. Taking advantage of the micro-fabrication technology, we have developed cantilever-based near-field microwave probes with shielded structures. Sensitive microwave electronics and finite-element analysis modeling are also utilized for quantitative electrical imaging. The system is fully compatible with atomic force microscope platforms for convenient operation and easy integration of other modes and functions. The microscope is ideal for interdisciplinary research, with demonstrated examples in nano electronics, physics, material science, and biology.

  7. Enthalpy Probe Technique for Thermal Plasma Diagnostics

    Institute of Scientific and Technical Information of China (English)

    冯晓珍

    2003-01-01

    The measuring principle and experimental results of the enthalpy probe techniquefor thermal plasma diagnostics are presented. Its calibration and errors are discussed. Typicalresults are presented for the system operation in an Ar/H2(5 % H2) plasma arc jet under a reactorchamber pressure of 101.3 kPa. The plasma temperature and velocity profiles are measured. Thecenter temperature and velocity are 6600 K and 850 m/s for plasma power 9 kW at axial locationof 17 mm.

  8. Gravity Probe B gyroscope readout system

    Science.gov (United States)

    Muhlfelder, B.; Lockhart, J.; Aljabreen, H.; Clarke, B.; Gutt, G.; Luo, M.

    2015-11-01

    We describe the Gravity Probe B London-moment readout system successfully used on-orbit to measure two gyroscope spin axis drift rates predicted by general relativity. The system couples the magnetic signal of a spinning niobium-coated rotor into a low noise superconducting quantum interference device. We describe the multi-layered magnetic shield needed to attenuate external fields that would otherwise degrade readout performance. We discuss the ∼35 nrad/yr drift rate sensitivity that was achieved on-orbit.

  9. Current perspectives on RNA secondary structure probing.

    Science.gov (United States)

    Kenyon, Julia; Prestwood, Liam; Lever, Andrew

    2014-08-01

    The range of roles played by structured RNAs in biological systems is vast. At the same time as we are learning more about the importance of RNA structure, recent advances in reagents, methods and technology mean that RNA secondary structural probing has become faster and more accurate. As a result, the capabilities of laboratories that already perform this type of structural analysis have increased greatly, and it has also become more widely accessible. The present review summarizes established and recently developed techniques. The information we can derive from secondary structural analysis is assessed, together with the areas in which we are likely to see exciting developments in the near future. PMID:25110033

  10. Atom Probe Tomography of Nanoscale Electronic Materials

    Energy Technology Data Exchange (ETDEWEB)

    Larson, David J.; Prosa, Ty J.; Perea, Daniel E.; Inoue, Hidekazu; Mangelinck, D.

    2016-01-01

    Atom probe tomography (APT) is a mass spectrometry based on time-of-flight measurements which also concurrently produces 3D spatial information. The reader is referred to any of the other papers in this volume or to the following references for further information 4–8. The current capabilities of APT, such as detecting a low number of dopant atoms in nanoscale devices or segregation at a nanoparticle interface, make this technique an important component in the nanoscale metrology toolbox. In this manuscript, we review some of the applications of APT to nanoscale electronic materials, including transistors and finFETs, silicide contact microstructures, nanowires, and nanoparticles.

  11. Probing the dynamical state of galaxy clusters

    CERN Document Server

    Puchwein, Ewald

    2007-01-01

    We show how hydrostatic equilibrium in galaxy clusters can be quantitatively probed combining X-ray, SZ, and gravitational-lensing data. Our previously published method for recovering three-dimensional cluster gas distributions avoids the assumption of hydrostatic equilibrium. Independent reconstructions of cumulative total-mass profiles can then be obtained from the gas distribution, assuming hydrostatic equilibrium, and from gravitational lensing, neglecting it. Hydrostatic equilibrium can then be quantified comparing the two. We describe this procedure in detail and show that it performs well on progressively realistic synthetic data. An application to a cluster merger demonstrates how hydrostatic equilibrium is violated and restored as the merger proceeds.

  12. Probing (topological) Floquet states through DC transport

    Science.gov (United States)

    Fruchart, M.; Delplace, P.; Weston, J.; Waintal, X.; Carpentier, D.

    2016-01-01

    We consider the differential conductance of a periodically driven system connected to infinite electrodes. We focus on the situation where the dissipation occurs predominantly in these electrodes. Using analytical arguments and a detailed numerical study we relate the differential conductances of such a system in two and three terminal geometries to the spectrum of quasi-energies of the Floquet operator. Moreover these differential conductances are found to provide an accurate probe of the existence of gaps in this quasi-energy spectrum, being quantized when topological edge states occur within these gaps. Our analysis opens the perspective to describe the intermediate time dynamics of driven mesoscopic conductors as topological Floquet filters.

  13. Ionization probes of molecular structure and chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, P.M. [State Univ. of New York, Stony Brook (United States)

    1993-12-01

    Various photoionization processes provide very sensitive probes for the detection and understanding of the spectra of molecules relevant to combustion processes. The detection of ionization can be selective by using resonant multiphoton ionization or by exploiting the fact that different molecules have different sets of ionization potentials. Therefore, the structure and dynamics of individual molecules can be studied even in a mixed sample. The authors are continuing to develop methods for the selective spectroscopic detection of molecules by ionization, and to use these methods for the study of some molecules of combustion interest.

  14. Crack detection by mobile photothermal probe

    Energy Technology Data Exchange (ETDEWEB)

    Bodnar, J.L.; Egee, M.; Menu, C. [Faculte des Sciences, Reims (France); Blanc, A. le; Besnard, R. [CEA, Saclay (France); Sellier, J.Y. [Intercontrole, Rungis (France)

    1994-12-31

    Within the frame of a previous study, encouraging results were obtained regarding the detection of microcracks by Photo Thermal Radiometry under sinusoidal excitation. However, the used method was too slow for an industrial application. It was therefore necessary to consider faster means of analysis. Such is the object of the present study. The authors show that, by using a mobile photothermal probe displaced relatively to the sample, it is possible to rapidly detect opened or non opened cracks, of a few tens of micrometers wide, and a few hundred of micrometers deep.

  15. Probing CP violation systematically in differential distributions

    CERN Document Server

    Durieux, Gauthier

    2015-01-01

    We revisit the topic of triple-product asymmetries which probe CP violation through differential distributions. We construct distributions with well-defined discrete symmetry properties and characterize the asymmetries formed upon them. It is stressed that the simplest asymmetries may not be optimal. We explore systematic generalizations having limited reliance on the process dynamics and phase-space parametrization. They exploit larger fractions of the information contained in differential distributions and may lead to increased sensitivities to CP violation. Our detailed treatment of the case of spinless four-body decays paves the way for further experimental studies.

  16. Electric probe for spin transition and fluctuation

    Science.gov (United States)

    Qiu, Zhiyong; Li, Jia; Hou, Dazhi; Arenholz, Elke; N'diaye, Alpha T.; Tan, Ali; Uchida, Ken-Ichi; Sato, Koji; Tserkovnyak, Yaroslov; Qiu, Z. Q.; Saitoh, Eiji

    Spin fluctuation and transition have always been one of central topics of magnetism and condense matter science. To probe them, neutron scatterings have been used as powerful tools. A part of neutrons injected into a sample is scattered by spin fluctuation inside the sample. This process transcribes the spin fluctuation onto scattering intensity, which is commonly represented by dynamical magnetic susceptibility of the sample and is maximized at magnetic phase transitions. Importantly, a neutron carries spin without electric charge, and it thus can bring spin into a sample without being disturbed by electric energy: an advantage of neutrons, although large facilities such as a nuclear reactor is necessary. Here we show that spin pumping, frequently used in nanoscale spintronic devices, provides a desktop micro probe for spin fluctuation and transition; not only a neutron beam, spin current is also a flux of spin without an electric charge and its transport reflects spin fluctuation in a sample. We demonstrate detection of anti-ferromagnetic transition in ultra-thin CoO films via frequency dependent spin-current transmission measurements.

  17. Mining information from atom probe data.

    Science.gov (United States)

    Cairney, Julie M; Rajan, Krishna; Haley, Daniel; Gault, Baptiste; Bagot, Paul A J; Choi, Pyuck-Pa; Felfer, Peter J; Ringer, Simon P; Marceau, Ross K W; Moody, Michael P

    2015-12-01

    Whilst atom probe tomography (APT) is a powerful technique with the capacity to gather information containing hundreds of millions of atoms from a single specimen, the ability to effectively use this information creates significant challenges. The main technological bottleneck lies in handling the extremely large amounts of data on spatial-chemical correlations, as well as developing new quantitative computational foundations for image reconstruction that target critical and transformative problems in materials science. The power to explore materials at the atomic scale with the extraordinary level of sensitivity of detection offered by atom probe tomography has not been not fully harnessed due to the challenges of dealing with missing, sparse and often noisy data. Hence there is a profound need to couple the analytical tools to deal with the data challenges with the experimental issues associated with this instrument. In this paper we provide a summary of some key issues associated with the challenges, and solutions to extract or "mine" fundamental materials science information from that data.

  18. Neutron probe monitoring of water in coke

    International Nuclear Information System (INIS)

    Coke moisture ranges between 5 and 7%. At coke sampling, inaccuracies occur in water content assessment. The results alter depending on hourly and daily samples and on sampling points. In the blast furnace situation where the knowledge of coke moisture is important for determining specific consumption of coke, the neutron moisture gauge continuous method has been proven. The effect was studied of different contents of volatile compounds in coke, as were the effects of the types of steel and the wall thickness of the neutron probe protective tube and those of big lumps of coke and of anomalous moisture on determination accuracy. The neutron probe operation may also be affected by bulk density and by consistency of the coke granulometric composition. The steel protective tube should be made of a strong material guaranteeing long-term invariability of measuring conditions. Mixing should not take place of compacting and bulk operation coke. Under these conditions, measurement can be sufficiently accurate. (M.D.). 2 tabs., 1 fig., 5 refs

  19. Fluorescent nanoparticle probes for imaging of cancer.

    Science.gov (United States)

    Santra, Swadeshmukul; Malhotra, Astha

    2011-01-01

    Fluorescent nanoparticles (FNPs) have received immense popularity in cancer imaging in recent years because of their attractive optical properties. In comparison to traditional organic-based fluorescent dyes and fluorescent proteins, FNPs offer much improved sensitivity and photostability. FNPs in certain size range have a strong tendency to enter and retain in solid tumor tissue with abnormal (leaky) vasculature--a phenomenon known as Enhanced Permeation and Retention (EPR) effect, advancing their use for in vivo tumor imaging. Furthermore, large surface area of FNPs and their usual core-shell structure offer a platform for designing and fabricating multimodal/multifunctional nanoparticles (MMNPs). For effective cancer imaging, often the optical imaging modality is integrated with other nonoptical-based imaging modalities such as MRI, X-ray, and PET, thus creating multimodal nanoparticle (NP)-based imaging probes. Such multimodal NP probes can be further integrated with therapeutic drug as well as cancer targeting agent leading to multifunctional NPs. Biocompatibility of FNPs is an important criterion that must be seriously considered during FNP design. NP composition, size, and surface chemistry must be carefully selected to minimize potential toxicological consequences both in vitro and in vivo. In this article, we will mainly focus on three different types of FNPs: dye-loaded NPs, quantum dots (Qdots), and phosphores; briefly highlighting their potential use in translational research. PMID:21480546

  20. Invited Review Article: Pump-probe microscopy.

    Science.gov (United States)

    Fischer, Martin C; Wilson, Jesse W; Robles, Francisco E; Warren, Warren S

    2016-03-01

    Multiphoton microscopy has rapidly gained popularity in biomedical imaging and materials science because of its ability to provide three-dimensional images at high spatial and temporal resolution even in optically scattering environments. Currently the majority of commercial and home-built devices are based on two-photon fluorescence and harmonic generation contrast. These two contrast mechanisms are relatively easy to measure but can access only a limited range of endogenous targets. Recent developments in fast laser pulse generation, pulse shaping, and detection technology have made accessible a wide range of optical contrasts that utilize multiple pulses of different colors. Molecular excitation with multiple pulses offers a large number of adjustable parameters. For example, in two-pulse pump-probe microscopy, one can vary the wavelength of each excitation pulse, the detection wavelength, the timing between the excitation pulses, and the detection gating window after excitation. Such a large parameter space can provide much greater molecular specificity than existing single-color techniques and allow for structural and functional imaging without the need for exogenous dyes and labels, which might interfere with the system under study. In this review, we provide a tutorial overview, covering principles of pump-probe microscopy and experimental setup, challenges associated with signal detection and data processing, and an overview of applications. PMID:27036751

  1. An approach to directly probe simultaneity

    Science.gov (United States)

    Kipreos, Edward T.; Balachandran, Riju S.

    2016-08-01

    The theory of special relativity derives from the Lorentz transformation. The Lorentz transformation implies differential simultaneity and light speed isotropy. Experiments to probe differential simultaneity should be able to distinguish the Lorentz transformation from a kinematically-similar alternate transformation that predicts absolute simultaneity, the absolute Lorentz transformation. Here, we describe how published optical tests of light speed isotropy/anisotropy cannot distinguish between the two transformations. We show that the shared equations of the two transformations, from the perspective of the “stationary” observer, are sufficient to predict null results in optical resonator experiments and in tests of frequency changes in one-way light paths. In an influential 1910 exposition on differential simultaneity, Comstock described how a “stationary” observer would observe different clock readings for spatially-separated “moving” clocks. The difference in clock readings is an integral aspect of differential simultaneity. We derive the equation for the difference in clock readings and show that it is equivalent to the Sagnac correction that describes light speed anisotropies in satellite communications. We describe an experimental strategy that can measure the differences in spatially-separated clock times to allow a direct probe of the nature of simultaneity.

  2. Results from the Wilkinson Microwave Anisotropy Probe

    Science.gov (United States)

    Komatsu, E.; Bennett, Charles L.; Komatsu, Eiichiro

    2015-01-01

    The Wilkinson Microwave Anisotropy Probe (WMAP) mapped the distribution of temperature and polarization over the entire sky in five microwave frequency bands. These full-sky maps were used to obtain measurements of temperature and polarization anisotropy of the cosmic microwave background with the unprecedented accuracy and precision. The analysis of two-point correlation functions of temperature and polarization data gives determinations of the fundamental cosmological parameters such as the age and composition of the universe, as well as the key parameters describing the physics of inflation, which is further constrained by three-point correlation functions. WMAP observations alone reduced the flat ? cold dark matter (Lambda Cold Dark Matter) cosmological model (six) parameter volume by a factor of > 68, 000 compared with pre-WMAP measurements. The WMAP observations (sometimes in combination with other astrophysical probes) convincingly show the existence of non-baryonic dark matter, the cosmic neutrino background, flatness of spatial geometry of the universe, a deviation from a scale-invariant spectrum of initial scalar fluctuations, and that the current universe is undergoing an accelerated expansion. The WMAP observations provide the strongest ever support for inflation; namely, the structures we see in the universe originate from quantum fluctuations generated during inflation.

  3. Invited Review Article: Pump-probe microscopy

    Science.gov (United States)

    Fischer, Martin C.; Wilson, Jesse W.; Robles, Francisco E.; Warren, Warren S.

    2016-03-01

    Multiphoton microscopy has rapidly gained popularity in biomedical imaging and materials science because of its ability to provide three-dimensional images at high spatial and temporal resolution even in optically scattering environments. Currently the majority of commercial and home-built devices are based on two-photon fluorescence and harmonic generation contrast. These two contrast mechanisms are relatively easy to measure but can access only a limited range of endogenous targets. Recent developments in fast laser pulse generation, pulse shaping, and detection technology have made accessible a wide range of optical contrasts that utilize multiple pulses of different colors. Molecular excitation with multiple pulses offers a large number of adjustable parameters. For example, in two-pulse pump-probe microscopy, one can vary the wavelength of each excitation pulse, the detection wavelength, the timing between the excitation pulses, and the detection gating window after excitation. Such a large parameter space can provide much greater molecular specificity than existing single-color techniques and allow for structural and functional imaging without the need for exogenous dyes and labels, which might interfere with the system under study. In this review, we provide a tutorial overview, covering principles of pump-probe microscopy and experimental setup, challenges associated with signal detection and data processing, and an overview of applications.

  4. MEMS-based fast scanning probe microscopes

    International Nuclear Information System (INIS)

    Scanning probe microscopy is a frequently used nanometer-scale surface investigation technique. Unfortunately, its applicability is limited by the relatively low image acquisition speed, typically seconds to minutes per image. Higher imaging speeds are desirable for rapid inspection of samples and for the study of a range of dynamic surface processes, such as catalysis and crystal growth. We have designed a new high-speed scanning probe microscope (SPM) based on micro-electro mechanical systems (MEMS). MEMS are small, typically micrometer size devices that can be designed to perform the scanning motion required in an SPM system. These devices can be optimized to have high resonance frequencies (up to the MHz range) and have very low mass (10-11 kg). Therefore, MEMS can perform fast scanning motion without exciting resonances in the mechanical loop of the SPM, and hence scan the surface without causing the image distortion from which conventional piezo scanners suffer. We have designed a MEMS z-scanner which we have integrated in commercial AFM (atomic force microscope) and STM (scanning tunneling microscope) setups. We show the first successful AFM experiments.

  5. Tests of Hadronic Probes of GT Strength

    CERN Multimedia

    2002-01-01

    There are many important problems where one wishes to know the distribution of Gamow-Teller (GT) strength in circumstances where it cannot be measured directly (for example, because of energy-release limitations). Then one must rely on hadronic probes to infer the GT strength. It is therefore essential to test these probes as extensively as possible. The isospin-analog transitions in $^{37}$Ca $\\beta^{+}$ -decay and $^{37}$Cl$(p, n)$ provide an excellent ground for such a test. Recent $^{37}$Cl$ (p, n) $ studies, while qualitatively in agreement with our previous ISOLDE work on $^{37}$Ca $\\beta^{+} $ -decay, show quantitative discrepancies that appear to grow as the excitation energy in the residual nuclei increases. Because of the bulk of the GT strengh appears at these high excitation energies, it is important to extend the $\\beta$-decay data to even higher excitation energies where, because of rapidly diminishing phase-space, strong GT transitions correspond to very weak $\\beta$ -branches. We propose to do...

  6. Design considerations for miniaturized optical neural probes

    Science.gov (United States)

    Rudmann, Linda; Ordonez, Juan S.; Stieglitz, Thomas

    2016-03-01

    Neural probes are designed to selectively record from or stimulate nerve cells. In optogenetics it is desirable to build miniaturized and long-term stable optical neural probes, in which the light sources can be directly and chronically implanted into the animals to allow free movement and behavior. Because of the size and the beam shape of the available light sources, it is difficult to target single cells as well as spatially localized networks. We therefore investigated design considerations for packages, which encapsulate the light source hermetically and have integrated hemispherical lens structures that enable to focus the light onto the desired region, by optical simulations. Integration of a biconvex lens into the package lid (diameter = 300 μm, material: silicon carbide) increased the averaged absolute irradiance ηA by 298 % compared to a system without a lens and had a spot size of around 120 μm. Solely integrating a plano-convex lens (same diameter and material) results in an ηA of up to 227 %.

  7. Single optical fiber probe for optogenetics

    Science.gov (United States)

    Falk, Ryan; Habibi, Mohammad; Pashaie, Ramin

    2012-03-01

    With the advent of optogenetics, all optical control and visualization of the activity of specific cell types is possible. We have developed a fiber optic based probe to control/visualize neuronal activity deep in the brain of awake behaving animals. In this design a thin multimode optical fiber serves as the head of the probe to be inserted into the brain. This fiber is used to deliver excitation/stimulation optical pulses and guide a sample of the emission signal back to a detector. The major trade off in the design of such a system is to decrease the size of the fiber and intensity of input light to minimize physical damage and to avoid photobleaching/phototoxicity but to keep the S/N reasonably high. Here the excitation light, and the associated emission signal, are frequency modulated. Then the output of the detector is passed through a time-lens which compresses the distributed energy of the emission signal and maximizes the instantaneous S/N. By measuring the statistics of the noise, the structure of the time lens can be designed to achieve the global optimum of S/N. Theoretically, the temporal resolution of the system is only limited by the time lens diffraction limit. By adding a second detector, we eliminated the effect of input light fluctuations, imperfection of the optical filters, and back-reflection of the excitation light. We have also designed fibers and micro mechanical assemblies for distributed delivery and detection of light.

  8. Short-time solvation dynamics probed by phase-locked heterodyne detected pump-probe

    NARCIS (Netherlands)

    de Boeij, W.P.; Pshenichnikov, M.S; Wiersma, D. A.

    1995-01-01

    Phase-locked heterodyne detected pump-probe experiments are reported on solutions of a dye molecule in ethylene glycol, methanol and acetonitrile. By performing experiments at different phase-lock wavelengths, the real and imaginary parts of the line broadening function g(t) could be mapped out. The

  9. PROBING STRESS EFFECTS IN SINGLE CRYSTAL ORGANIC TRANSISTORS BY SCANNING KELVIN PROBE MICROSCOPY

    Energy Technology Data Exchange (ETDEWEB)

    Teague, L

    2010-06-11

    We report scanning Kelvin probe microscopy (SKPM) of single crystal difluoro bis(triethylsilylethynyl) anthradithiophene (diF-TESADT) organic transistors. SKPM provides a direct measurement of the intrinsic charge transport in the crystals independent of contact effects and reveals that degradation of device performance occurs over a time period of minutes as the diF-TESADT crystal becomes charged.

  10. Simulation of a four sensor probe using a rotating dual sensor probe

    OpenAIRE

    Panayotopoulos, Nikolaos; Lucas, Gary; Pradhan, Suman

    2006-01-01

    In the current project a rotating dual sensor probe has been designed and fabricated. A set of measurements were performed using the rotating dual sensor. Analysis on the results occurred, and it showed that the rotating dual sensor with the supporting algorithm has an acceptable, reliable and repeatable performance for measurements in multiphase flows.

  11. COTS MEMS Flow-Measurement Probes

    Science.gov (United States)

    Redding, Chip; Smith, Floyd A.; Blank, Greg; Cruzan, Charles

    2004-01-01

    As an alternative to conventional tubing instrumentation for measuring airflow, designers and technicians at Glenn Research Center have been fabricating packaging components and assembling a set of unique probes that contain commercial off-the-shelf (COTS) microelectromechanical systems (MEMS) sensor chips. MEMS sensor chips offer some compelling advantages over standard macroscopic measurement devices. MEMS sensor technology has matured through mass production and use in the automotive and aircraft industries. At present, MEMS are the devices of choice for sensors in such applications as tire-pressure monitors, altimeters, pneumatic controls, cable leak detectors, and consumer appliances. Compactness, minimality of power demand, rugged construction, and moderate cost all contribute to making MEMS sensors attractive for instrumentation for future research. Conventional macroscopic flow-measurement instrumentation includes tubes buried beneath the aerodynamic surfaces of wind-tunnel models or in wind-tunnel walls. Pressure is introduced at the opening of each such tube. The pressure must then travel along the tube before reaching a transducer that generates an electronic signal. The lengths of such tubes typically range from 20 ft (approx.= 6 m) to hundreds of feet (of the order of 100 m). The propagation of pressure signals in the tubes damps the signals considerably and makes it necessary to delay measurements until after test rigs have reached steady-state operation. In contrast, a MEMS pressure sensor that generates electronic output can take readings continuously under dynamic conditions in nearly real time. In order to use stainless-steel tubing for pressure measurements, it is necessary to clean many tubes, cut them to length, carefully install them, delicately deburr them, and splice them. A cluster of a few hundred 1/16-in.- (approx.=1.6-mm-) diameter tubes (such clusters are common in research testing facilities) can be several inches (of the order of 10

  12. Self optical motion-tracking for endoscopic optical coherence tomography probe using micro-beamsplitter probe

    Science.gov (United States)

    Li, Jiawen; Zhang, Jun; Chou, Lidek; Wang, Alex; Jing, Joseph; Chen, Zhongping

    2014-03-01

    Long range optical coherence tomography (OCT), with its high speed, high resolution, non-ionized properties and cross-sectional imaging capability, is suitable for upper airway lumen imaging. To render 2D OCT datasets to true 3D anatomy, additional tools are usually applied, such as X-ray guidance or a magnetic sensor. X-ray increases ionizing radiation. A magnetic sensor either increases probe size or requires an additional pull-back of the tracking sensor through the body cavity. In order to overcome these limitations, we present a novel tracking method using a 1.5 mm×1.5mm, 90/10-ratio micro-beamsplitter: 10% light through the beam-splitter is used for motion tracking and 90% light is used for regular OCT imaging and motion tracking. Two signals corresponding to these two split-beams that pass through different optical path length delays are obtained by the detector simultaneously. Using the two split beams' returned signals from the same marker line, the 2D inclination angle of each step is computed. By calculating the 2D inclination angle of each step and then connecting the translational displacements of each step, we can obtain the 2D motion trajectory of the probe. With two marker lines on the probe sheath, 3D inclination angles can be determined and then used for 3D trajectory reconstruction. We tested the accuracy of trajectory reconstruction using the probe and demonstrated the feasibility of the design for structure reconstruction of a biological sample using a porcine trachea specimen. This optical-tracking probe has the potential to be made as small as an outer diameter of 1.0mm, which is ideal for upper airway imaging.

  13. Birefringence effects of short probe pulses of electromagnetically induced transparency

    Science.gov (United States)

    Parshkov, Oleg M.; Kochetkova, Anastasia E.; Budyak, Victoria V.

    2016-04-01

    The numerical simulation results of radiations evolution in the presence of electromagnetically induced transparency for J=0-->J=1-->J=2 scheme of degenerate quantum transitions are presented. The pulse regime of wave interaction with Doppler broadening spectral lines was investigated. It was indicated that when the control field is linear polarized, the input circular polarized probe pulse breaks up in the medium into pulses with mutually perpendicular linear polarizations. Polarization direction of one of these pulses coincides with the polarization direction of control fields. The distance, which probe pulse passes in the medium to its full separation, decreases, when input probe pulse duration or control field intensity decreases. The input probe pulse intensity variation almost does not influence separation distance and speed of the linear polarized probe pulses in the medium. The effects, described above, may be interpreted as the birefringence effects of electromagnetically induced transparency in the case of short probe pulse.

  14. Corrosion probes for fireside monitoring in coal-fired boilers

    Energy Technology Data Exchange (ETDEWEB)

    Covino, Bernard S., Jr.; Bullard, Sophie J.; Cramer, Stephen D.; Holcomb, Gordon R.; Ziomek-Moroz, Margaret; Eden, David A. (Intercorr International Inc.); Cayard, Michael S. (Intercorr International Inc.)

    2004-01-01

    Electrochemical corrosion rate (ECR) probes were constructed and exposed along with mass loss coupons in a N2/O2/CO2/H2O environment to determine ECR probe operating characteristics. Temperatures ranged from 450 to 600 C and both ECR probes and mass loss coupons were coated with ash. Results are presented in terms of the probe response to temperature, the measured zero baseline, and the quantitative nature of the probes. The effect of Stern-Geary constant and the choice of electrochemical technique used to measure the corrosion rate are also discussed. ECR probe corrosion rates were a function of time, temperature, and process environment and were found to be quantitative for some test conditions. Measured Stern-Geary constants averaged 0.0141 V/decade and the linear polarization technique was found to be more quantitative than the electrochemical noise technique.

  15. Electrochemical corrosion rate probes for high temperature energy applications

    Energy Technology Data Exchange (ETDEWEB)

    Covino, Bernard S., Jr.; Bullard, Sophie J.; Cramer, Stephen D.; Holcomb, Gordon R.; Ziomek-Moroz, M.; Cayard, M.S. (InterCorr International Inc.); Eden, D.A. (InterCorr International Inc.)

    2004-01-01

    Electrochemical corrosion rate (ECR) probes were constructed and exposed along with mass loss coupons in a N2/O2/CO2/H2O environment to determine ECR probe operating characteristics. Temperatures ranged from 450 to 800 C and both ECR probes and mass loss coupons were coated with ash. Results are presented in terms of the probe response to temperature, the measured zero baseline, and the quantitative nature of the probes. The effect of Stern-Geary constant and the choice of electrochemical technique used to measure the corrosion rate are also discussed. ECR probe corrosion rates were a function of time, temperature, and process environment and were found to be quantitative for some test conditions. Measured Stern-Geary constants averaged 0.0141 V/decade and the linear polarization technique was found to be more quantitative than the electrochemical noise technique.

  16. Development and field practical performance of smart array probe

    International Nuclear Information System (INIS)

    In 1999, NEL developed the transmit-receive type ECT array probe for steam generator (SG) tubing, called 'X-probe', in cooperation with foreign firms. Recently NEL has developed the advanced ECT array probe, 'Smart Array Probe', characterized with a significantly improved resolution for circumferential cracks. The doubled channels in the circumferential mode have greatly improved the circumferential resolution of Smart Array Probe. With all the circumferential mode channels on the same circle, there is no need for axial position correction of inspection data. This report describes both the field practical performance and the compliance assessment to a Japanese SG-ECT guideline 'JEAG4208' of Smart Array ECT System, composed of Smart Array Probe, pusher-in-tester 'OMNI-200', and NEL's ECT Analysis System. (author)

  17. An improved probe noise approach for acoustic feedback cancellation

    DEFF Research Database (Denmark)

    Guo, Meng; Jensen, Søren Holdt; Jensen, Jesper

    2012-01-01

    The perhaps most challenging problem in acoustic feedback cancellation using adaptive filters is the bias problem. It is well-known that a probe noise approach can effectively prevent this problem. However, when the probe noise must be inaudible and the steady-state error of the adaptive filter...... must be unchanged, this approach causes a significantly decreased convergence rate of the adaptive filter, and might thereby be less useful in practical applications. In this work, we propose a new probe noise approach which significantly increases the convergence rate while maintaining the steady-state...... error of the adaptive algorithm in a multiple-microphone and single-loudspeaker audio system. This is obtained through a specifically designed probe noise signal and a corresponding probe noise enhancement strategy. We show the effects of the proposed probe noise approach by deriving analytical...

  18. A single probe for imaging photons, electrons and physical forces

    Science.gov (United States)

    Pilet, Nicolas; Lisunova, Yuliya; Lamattina, Fabio; Stevenson, Stephanie E.; Pigozzi, Giancarlo; Paruch, Patrycja; Fink, Rainer H.; Hug, Hans J.; Quitmann, Christoph; Raabe, Joerg

    2016-06-01

    The combination of complementary measurement techniques has become a frequent approach to improve scientific knowledge. Pairing of the high lateral resolution scanning force microscopy (SFM) with the spectroscopic information accessible through scanning transmission soft x-ray microscopy (STXM) permits assessing physical and chemical material properties with high spatial resolution. We present progress from the NanoXAS instrument towards using an SFM probe as an x-ray detector for STXM measurements. Just by the variation of one parameter, the SFM probe can be utilised to detect either sample photo-emitted electrons or transmitted photons. This allows the use of a single probe to detect electrons, photons and physical forces of interest. We also show recent progress and demonstrate the current limitations of using a high aspect ratio coaxial SFM probe to detect photo-emitted electrons with very high lateral resolution. Novel probe designs are proposed to further progress in using an SFM probe as a STXM detector.

  19. Use of vaccines as probes to define disease burden

    OpenAIRE

    Feikin, Daniel R.; J Anthony G Scott; Gessner, Bradford D

    2014-01-01

    Vaccine probe studies have emerged in the past 15 years as a useful way to characterise disease. By contrast, traditional studies of vaccines focus on defining the vaccine effectiveness or efficacy. The underlying basis for the vaccine probe approach is that the difference in disease burden between vaccinated and unvaccinated individuals can be ascribed to the vaccine-specific pathogen. Vaccine probe studies can increase understanding of a vaccine’s public health value. For instance, even whe...

  20. Probing Yukawian Gravitational Potential by Numerical Simulations. II. Elliptical Galaxies

    OpenAIRE

    Brandao, C. S. S.; de Araujo, J. C. N.

    2009-01-01

    Since the Newtonian gravitation is largely used to model with success the structures of the universe, such as galaxies and clusters of galaxies, for example, a way to probe and constrain alternative theories, in the weak field limit, is to apply them to model the structures of the universe. We then modified the well known Gadget-2 code to probe alternative theories of gravitation through galactic dynamics. In particular, we modified the Gadget-2 code to probe alternatives theories whose weak ...

  1. Probing Quantum Capacitance in a 3D Topological Insulator

    OpenAIRE

    Kozlov, D. A.; Bauer, Dominik; Ziegler, Johannes; Fischer, Ralf, 1965-; Savchenko, M. L.; Kvon, Z.D.; Mikhailov, N. N.; Dvoretsky, S. A.; Weiss, Dieter

    2016-01-01

    We measure the quantum capacitance and probe thus directly the electronic density of states of the high mobility, Dirac type of two-dimensional electron system, which forms on the surface of strained HgTe. Here we show that observed magneto-capacitance oscillations probe, in contrast to magnetotransport, primarily the top surface. Capacitance measurements constitute thus a powerful tool to probe only one topological surface and to reconstruct its Landau level spectrum for different positions ...

  2. Automatic probe artifact detection in MRI-guided cryoablation

    Science.gov (United States)

    Liu, Xinyang; Tuncali, Kemal; Wells, William M.; Zientara, Gary P.

    2013-03-01

    Probe or needle artifact detection in 3D scans gives an approximate location for the tools inserted, and is thus crucial in assisting many image-guided procedures. Conventional needle localization algorithms often start with cropped images, where unwanted parts of raw scans are cropped either manually or by applying pre-defined masks. In cryoablation, however, the number of probes used, the placement and direction of probe insertion, and the portions of abdomen scanned differs significantly from case to case, and probes are often constantly being adjusted during the Probe Placement Phase. These features greatly reduce the practicality of approaches based on image cropping. In this work, we present a fully Automatic Probe Artifact Detection method, APAD, that works directly on uncropped raw MRI images, taken during the Probe Placement Phase in 3Tesla MRI-guided cryoablation. The key idea of our method is to first locate an initial 2D line strip within a slice of the MR image which approximates the position and direction of the 3D probes bundle, noting that cryoprobes or biopsy needles create a signal void (black) artifact in MRI with a bright cylindrical border. With the initial 2D line, standard approaches to detect line structures such as the 3D Hough Transform can be applied to quickly detect each probe's axis. By comparing with manually labeled probes, the analysis of 5 patient treatment cases of kidney cryoablation with varying probe placements demonstrates that our algorithm combined with standard 3D line detection is an accurate and robust method to detect probe artifacts.

  3. Voltage and dephasing probes: a full counting statistics discussion

    OpenAIRE

    Forster, Heidi; Samuelsson, Martin Peter; Pilgram, Sebastian; Buttiker, Markus

    2006-01-01

    Voltage and dephasing probes introduce incoherent inelastic and incoherent quasi-elastic scattering into a coherent mesoscopic conductor. We discuss in detail the concepts of voltage and dephasing probes and develop a full counting statistics approach to investigate their effect on the transport statistics. The formalism is applied to several experimentally relevant examples. A comparison of different probe models and with procedures like phase averaging over an appropriate phase distribution...

  4. 33S NMR cryogenic probe for taurine detection

    Science.gov (United States)

    Hobo, Fumio; Takahashi, Masato; Maeda, Hideaki

    2009-03-01

    With the goal of a S33 nuclear magnetic resonance (NMR) probe applicable to in vivo NMR on taurine-biological samples, we have developed the S33 NMR cryogenic probe, which is applicable to taurine solutions. The NMR sensitivity gain relative to a conventional broadband probe is as large as 3.5. This work suggests that improvements in the preamplifier could allow NMR measurements on 100 μM taurine solutions, which is the level of sensitivity necessary for biological samples.

  5. Automatic system for driving probes of electron cyclotron

    International Nuclear Information System (INIS)

    The automatic system for driving six probes used on electron model of the ring cyclotron is described. This system allows one to move probes one by one or simultaneously. The active forcing of the process of switching on of the current in phase windings is used a driving scheme of step-motors. The shift of probes from one radius to other can be carried out both from the front panel of driving device (autonomous regime), and from the computer

  6. Portable optical fiber probe for in vivo brain temperature measurements.

    Science.gov (United States)

    Musolino, Stefan; Schartner, Erik P; Tsiminis, Georgios; Salem, Abdallah; Monro, Tanya M; Hutchinson, Mark R

    2016-08-01

    This work reports on the development of an optical fiber based probe for in vivo measurements of brain temperature. By utilizing a thin layer of rare-earth doped tellurite glass on the tip of a conventional silica optical fiber a robust probe, suitable for long-term in vivo measurements of temperature can be fabricated. This probe can be interrogated using a portable optical measurement setup, allowing for measurements to be performed outside of standard optical laboratories.

  7. Plasma diagnostics with Langmuir probes in strong magnetic fields

    International Nuclear Information System (INIS)

    Theoretical model of plasma diagnostics with Langmuir probe in a strong magnetic field is presented. The model considers the geometry and the shape of the probe, which have been neglected in previous approximate studies of this problem. Although the plasma is strongly disturbed by the probe and plasma density and potential are locally changed, the unperturbed plasma density, η0, the electron temperature, Te, and the unknown cross-field diffusion coefficient, can be determined from certain parts of the measured I-V characteristics of the probe. (author)

  8. Some probe experiments on a high energy cesium ion beam

    Energy Technology Data Exchange (ETDEWEB)

    Hubach, R. A.; Peppin, G. B.

    1963-03-31

    A probe has been developed which is, in effect, a directional Langmuir probe. The directional quality is necessary for use in a beam of high energy ions to eliminate the effects of the streaming ions on the probe operation. This probe has been utilized to measure the back-streaming (albedo) electron component to verify the bottle model of space-charge neutralization. It has also been possible to infer the density of slow ions in the beam created by gas ionization and to infer a value of the cross section for such gas ionization which .agrees with the anticipated value. (auth)

  9. Custom-designed MLPA using multiple short synthetic probes

    DEFF Research Database (Denmark)

    Serizawa, R.R.; Ralfkiaer, U.; Dahl, C.;

    2010-01-01

    Ligation of two oligonucleotide probes hybridized adjacently to a DNA template has been widely used for detection of genome alterations. The multiplex ligation-dependent probe amplification (MLPA) technique allows simultaneous screening of multiple target sequences in a single reaction by using......-stranded bacteriophage vector to introduce a sequence of defined length between the primer binding site and the specific target sequence. Here we demonstrate that differences in amplicon length can be achieved by using multiple short synthetic probes for each target sequence. When joined by a DNA ligase, these probes...

  10. Measurement Uncertainty Investigation in the Multi-probe OTA Setups

    DEFF Research Database (Denmark)

    Fan, Wei; Szini, Istvan Janos; Foegelle, M. D.;

    2014-01-01

    metrics in real world scenarios, the multi-probe based method has attracted huge interest from both industry and academia. This contribution attempts to identify some of the measurement uncertainties of the practical multi-probe setups and provide some guidance to establish the multi-probe anechoic...... chamber setup. This contribution presents the results of uncertainty measurements carried out in three practical multi-probe setups. Some sources of measurement errors, i.e. cable effect, cable termination, etc. are identified based on the measurement results....

  11. Alternative mapping of probes to genes for Affymetrix chips

    Directory of Open Access Journals (Sweden)

    Friis-Hansen Lennart

    2004-08-01

    Full Text Available Abstract Background Short oligonucleotide arrays have several probes measuring the expression level of each target transcript. Therefore the selection of probes is a key component for the quality of measurements. However, once probes have been selected and synthesized on an array, it is still possible to re-evaluate the results using an updated mapping of probes to genes, taking into account the latest biological knowledge available. Methods We investigated how probes found on recent commercial microarrays for human genes (Affymetrix HG-U133A were matching a recent curated collection of human transcripts: the NCBI RefSeq database. We also built mappings and used them in place of the original probe to genes associations provided by the manufacturer of the arrays. Results In a large number of cases, 36%, the probes matching a reference sequence were consistent with the grouping of probes by the manufacturer of the chips. For the remaining cases there were discrepancies and we show how that can affect the analysis of data. Conclusions While the probes on Affymetrix arrays remain the same for several years, the biological knowledge concerning the genomic sequences evolves rapidly. Using up-to-date knowledge can apparently change the outcome of an analysis.

  12. Study of a Laser-Produced Plasma by Langmuir Probes

    DEFF Research Database (Denmark)

    Chang, C. T.; Hasimi, M.; Pant, H. C.

    1977-01-01

    The structure, the parameters and the expansion of the plasma produced by focusing a 7 J, 20 ns Nd-glass laser on stainless-steel and glass targets suspended in a high-vacuum chamber were investigated by Langmuir probes. It was observed that the probe signals consisted of a photoelectric-emission......The structure, the parameters and the expansion of the plasma produced by focusing a 7 J, 20 ns Nd-glass laser on stainless-steel and glass targets suspended in a high-vacuum chamber were investigated by Langmuir probes. It was observed that the probe signals consisted of a photoelectric...

  13. Nanostructuring carbon fibre probes for use in central venous catheters.

    Science.gov (United States)

    Li, Meixian; Phair, Jolene; Cardosi, Marco F; Davis, James

    2014-02-17

    A carbon fibre probe is described which utilises the oxidation of an endogenous biomarker to provide diagnostic information on the condition of intravascular access lines. The probe surface was modified through anodic oxidation to provide a high selectivity towards urate which was used as a redox probe through which the pH could be determined. A Nernstian response (-60 mV/pH) was obtained which was free from the interference of other redox species common to biofluids. The electroanalytical performance of the probe has been optimised and the applicability of the approach demonstrated through testing the responses in whole blood.

  14. Combined fiber probe for fluorescence lifetime and Raman spectroscopy

    Science.gov (United States)

    Dochow, Sebastian; Ma, Dinglong; Latka, Ines; Bocklitz, Thomas; Hartl, Brad; Bec, Julien; Fatakdawala, Hussain; Marple, Eric; Urmey, Kirk; Wachsmann-Hogiu, Sebastian; Schmitt, Michael; Marcu, Laura; Popp, Jürgen

    2016-01-01

    In this contribution we present a dual modality fiber optic probe combining fluorescence lifetime imaging (FLIm) and Raman spectroscopy for in vivo endoscopic applications. The presented multi-spectroscopy probe enables efficient excitation and collection of fluorescence lifetime signals for FLIm in the UV/visible wavelength region, as well as of Raman spectra in the near-IR for simultaneous Raman/FLIm imaging. The probe was characterized in terms of its lateral resolution and distance dependency of the Raman and FLIm signals. In addition, the feasibility of the probe for in vivo FLIm and Raman spectral characterization of tissue was demonstrated. PMID:26093843

  15. Field enhancement effect of metal probe in evanescent field

    Institute of Scientific and Technical Information of China (English)

    Xiaogang Hong; Wendong Xu; Xiaogang Li; Chengqiang Zhao; Xiaodong Tang

    2009-01-01

    Field enhancement effect of metal probe in evanescent field, induced by using a multi-layers structure for exciting surface plasmon resonance (SPR), is analyzed numerically by utilizing two-dimensional (2D) TM wave finite difference time-domain (FDTD) method. In this letter, we used a fundamental mode Gaussian beam to induce evanescent field, and calculated the electric intensity. The results show that compared with the nonmetal probe, the metal probe has a larger field enhancement effect, and its scattering wave induced by field enhancement has a bigger decay coefficient. The field enhancement effect should conclude that the metal probe has an important application in nanolithography.

  16. Improving comparability between microarray probe signals by thermodynamic intensity correction

    DEFF Research Database (Denmark)

    Bruun, G. M.; Wernersson, Rasmus; Juncker, Agnieszka;

    2007-01-01

    different probes. It is therefore of great interest to correct for the variation between probes. Much of this variation is sequence dependent. We demonstrate that a thermodynamic model for hybridization of either DNA or RNA to a DNA microarray, which takes the sequence-dependent probe affinities...... determination of transcription start sites for a subset of yeast genes. In another application, we identify present/absent calls for probes hybridized to the sequenced Escherichia coli strain O157:H7 EDL933. The model improves the correct calls from 85 to 95% relative to raw intensity measures. The model thus...

  17. Strand-invading linear probe combined with unmodified PNA.

    Science.gov (United States)

    Asanuma, Hiroyuki; Niwa, Rie; Akahane, Mariko; Murayama, Keiji; Kashida, Hiromu; Kamiya, Yukiko

    2016-09-15

    Efficient strand invasion by a linear probe to fluorescently label double-stranded DNA has been implemented by employing a probe and unmodified PNA. As a fluorophore, we utilized ethynylperylene. Multiple ethynylperylene residues were incorporated into the DNA probe via a d-threoninol scaffold. The ethynylperylene did not significantly disrupt hybridization with complementary DNA. The linear probe self-quenched in the absence of target DNA and did not hybridize with PNA. A gel-shift assay revealed that linear probe and PNA combination invaded the central region of double-stranded DNA upon heat-shock treatment to form a double duplex. To further suppress the background emission and increase the stability of the probe/DNA duplex, a probe containing anthraquinones as well as ethynylperylene was synthesized. This probe and PNA invader pair detected an internal sequence in a double-stranded DNA with high sensitivity when heat shock treatment was used. The probe and PNA pair was able to invade at the terminus of a long double-stranded DNA at 40°C at 100mM NaCl concentration. PMID:27394693

  18. Probe Error Modeling Research Based on Bayesian Network

    Institute of Scientific and Technical Information of China (English)

    Wu Huaiqiang; Xing Zilong; Zhang Jian; Yan Yan

    2015-01-01

    Probe calibration is carried out under specific conditions; most of the error caused by the change of speed parameter has not been corrected. In order to reduce the measuring error influence on measurement accuracy, this article analyzes the relationship between speed parameter and probe error, and use Bayesian network to establish the model of probe error. Model takes account of prior knowledge and sample data, with the updating of data, which can reflect the change of the errors of the probe and constantly revised modeling results.

  19. Designs of Langmuir probes for W7-X

    Energy Technology Data Exchange (ETDEWEB)

    Laube, Ralph, E-mail: ralph.laube@ipp.mpg.de [Max-Planck-Institut fuer Plasmaphysik, EURATOM Association, Teilinstitut Greifswald, Wendelsteinstr. 1, D-17491 Greifswald (Germany); Laux, Michael; Ye, Min You [Max-Planck-Institut fuer Plasmaphysik, EURATOM Association, Teilinstitut Greifswald, Wendelsteinstr. 1, D-17491 Greifswald (Germany); Greuner, Henri; Lindig, Stefan [Max-Planck-Institut fuer Plasmaphysik, EURATOM Association, Boltzmannstr. 2, D-85748 Garching (Germany)

    2011-10-15

    Several designs of Langmuir probes for the stellarator Wendelstein 7-X (W7-X) are described. Different types of probes are proposed for the different divertors to be used during different operational phases of W7-X. Comb-like arrays of stiff probes, arrays of flexible probes, and fixed inlay probes are reviewed. For the initial phase of W7-X it was decided to install arrays of fixed inlay probes. Two mockups were manufactured and one of them was tested with success in the high heat flux test facility GLADIS. For long-pulse operation of W7-X different conceptual designs are proposed and are still developed further. This paper summarizes the different design constrains for the Langmuir probes in the different divertor surroundings, describes the design of the array of inlay probes for the initial phase and the result of the GLADIS test, and gives a preview of the conceptual designs of probes for the long-pulse operational phase of W7-X.

  20. Endoscopically compatible near-infrared photon migration probe

    Science.gov (United States)

    Lubawy, Carmalyn; Ramanujam, Nirmala

    2004-09-01

    We have developed a 2.3-mm-diameter fiber-optic probe for near-infrared photon migration spectroscopy that can be inserted into the body through an endoscope or biopsy needle. This probe is specifically designed to be inserted into a core biopsy needle to facilitate optical sampling of lesions during breast needle biopsy. This probe was tested on tissue phantoms containing heterogeneities (to stimulate breast lesions) of various sizes and optical properties. Under the conditions tested, the probe can measure the absorption coefficient to within 30% for heterogeneities with radii as small as 10 mm.

  1. Spatial resolution in atom probe tomography

    CERN Document Server

    Gault, Baptiste; de Geuser, Frederic; La Fontaine, Alex; Stephenson, Leigh T; Haley, Daniel; Ringer, Simon P

    2015-01-01

    This article addresses gaps in definitions and a lack of standard measurement techniques to assess the spatial resolution in atom probe tomography. This resolution is known to be anisotropic, being better in the depth than laterally. Generally the presence of atomic planes in the tomographic reconstruction is considered as being a sufficient proof of the quality of the spatial resolution of the instrument. Based on advanced spatial distribution maps, an analysis methodology that interrogates the local neighborhood of the atoms within the tomographic reconstruction, it is shown how both the in-depth and the lateral resolution can be quantified. The influences of the crystallography and the temperature are investigated, and models are proposed to explain the observed results. We demonstrate that the absolute value of resolution is specimenspecific.

  2. Probing bound states of D-branes

    CERN Document Server

    Lifschytz, G

    1996-01-01

    A zero-brane is used to probe non-threshold BPS bound states of ($p$, $p+2$,$p+4$)-branes. At long distances the stringy calculation agrees with the supergravity calculations. The supergravity description is given, using the interpretation of the $D=8$ dyonic membrane as the bound state of a two-brane inside a four-brane. We investigate the short distance structure of these bound states, compute the phase shift of the scattered zero-brane and find the bound states characteristic size. It is found that there should be a supersymmetric solution of type IIa supergravity, describing a bound state of a zero-brane and two orthogonal two-brane, all inside a four-brane , with an additional unbound zero-brane. We comment on the relationship between $p$-branes and $(p-2)$-branes.

  3. Probing dark particles indirectly at the CEPC

    CERN Document Server

    Cao, Qing-Hong; Yan, Bin; Zhang, Ya; Zhang, Zhen

    2016-01-01

    When dark matter candidate and its parent particles are nearly degenerate, it would be difficult to probe them at the Large Hadron Collider directly. We propose to explore their quantum loop effects at the CEPC through the golden channel process $e^+e^-\\to \\mu^+\\mu^-$. We use a renormalizable toy model consisting of a new scalar and a fermion to describe new physics beyond the Standard Model. The new scalar and fermion are general multiplets of the $SU(2)_L\\times U(1)_Y$ symmetry, and couple to the muon lepton through Yukawa interaction. We calculate their loop contributions to anomalous $\\gamma\\mu^+\\mu^-$ and $Z\\mu^+\\mu^-$ couplings which can be applied to many new physics models. The prospects of their effects at the CEPC are also examined assuming a 0.002 accuracy in the cross section measurement.

  4. Probing dark particles indirectly at the CEPC

    Science.gov (United States)

    Cao, Qing-Hong; Li, Yang; Yan, Bin; Zhang, Ya; Zhang, Zhen

    2016-08-01

    When dark matter candidate and its parent particles are nearly degenerate, it would be difficult to probe them at the Large Hadron Collider directly. We propose to explore their quantum loop effects at the CEPC through the golden channel process e+e- →μ+μ-. We use a renormalizable toy model consisting of a new scalar and a fermion to describe new physics beyond the Standard Model. The new scalar and fermion are general multiplets of the SU(2)L × U(1)Y symmetry, and couple to the muon lepton through Yukawa interaction. We calculate their loop contributions to anomalous γμ+μ- and Zμ+μ- couplings which can be applied to many new physics models. The prospects of their effects at the CEPC are also examined assuming a 2‰ accuracy in the cross section measurement.

  5. Interferometric probes of many-body localization.

    Science.gov (United States)

    Serbyn, M; Knap, M; Gopalakrishnan, S; Papić, Z; Yao, N Y; Laumann, C R; Abanin, D A; Lukin, M D; Demler, E A

    2014-10-01

    We propose a method for detecting many-body localization (MBL) in disordered spin systems. The method involves pulsed coherent spin manipulations that probe the dephasing of a given spin due to its entanglement with a set of distant spins. It allows one to distinguish the MBL phase from a noninteracting localized phase and a delocalized phase. In particular, we show that for a properly chosen pulse sequence the MBL phase exhibits a characteristic power-law decay reflecting its slow growth of entanglement. We find that this power-law decay is robust with respect to thermal and disorder averaging, provide numerical simulations supporting our results, and discuss possible experimental realizations in solid-state and cold-atom systems. PMID:25325656

  6. Gravity Probe B data system description

    Science.gov (United States)

    Bennett, Norman R.

    2015-11-01

    The Gravity Probe B data system, developed, integrated, and tested by Lockheed Missiles & Space Company, and later Lockheed Martin Corporation, included flight and ground command, control, and communications software. The development was greatly facilitated, conceptually and by the transfer of key personnel, through Lockheed’s earlier flight and ground test software development for the Hubble Space Telescope (HST). Key design challenges included the tight mission timeline (17 months, 9 days of on-orbit operation), the need to tune the system once on-orbit, and limited 2 Kbps real-time data rates and ground asset availability. The result was a completely integrated space vehicle and Stanford mission operations center, which successfully collected and archived 97% of the ‘guide star valid’ data to support the science analysis. Lessons learned and incorporated from the HST flight software development and on-orbit support experience, and Lockheed’s independent research and development effort, will be discussed.

  7. Chemical sensor with oscillating cantilevered probe

    Science.gov (United States)

    Adams, Jesse D

    2013-02-05

    The invention provides a method of detecting a chemical species with an oscillating cantilevered probe. A cantilevered beam is driven into oscillation with a drive mechanism coupled to the cantilevered beam. A free end of the oscillating cantilevered beam is tapped against a mechanical stop coupled to a base end of the cantilevered beam. An amplitude of the oscillating cantilevered beam is measured with a sense mechanism coupled to the cantilevered beam. A treated portion of the cantilevered beam is exposed to the chemical species, wherein the cantilevered beam bends when exposed to the chemical species. A second amplitude of the oscillating cantilevered beam is measured, and the chemical species is determined based on the measured amplitudes.

  8. Probing the Casimir force with optical tweezers

    CERN Document Server

    Ether, D S; Umrath, S; Martinez, D; Ayala, Y; Pontes, B; Araújo, G R de S; Frases, S; Ingold, G -L; Rosa, F S S; Viana, N B; Nussenzveig, H M; Neto, P A Maia

    2015-01-01

    We propose to use optical tweezers to probe the Casimir interaction between microspheres inside a liquid medium for geometric aspect ratios far beyond the validity of the widely employed proximity force approximation. This setup has the potential for revealing unprecedented features associated to the non-trivial role of the spherical curvatures. For a proof of concept, we measure femtonewton double layer forces between polystyrene microspheres at distances above $400$ nm by employing very soft optical tweezers, with stiffness of the order of fractions of a fN/nm. As a future application, we propose to tune the Casimir interaction between a metallic and a polystyrene microsphere in saline solution from attraction to repulsion by varying the salt concentration. With those materials, the screened Casimir interaction may have a larger magnitude than the unscreened one. This line of investigation has the potential for bringing together different fields including classical and quantum optics, statistical physics an...

  9. An approach to directly probe simultaneity

    CERN Document Server

    Kipreos, Edward T

    2016-01-01

    The theory of special relativity derives from the Lorentz transformation. The Lorentz transformation implies differential simultaneity and light speed isotropy. Experiments to probe differential simultaneity should be able to distinguish the Lorentz transformation from a kinematically-similar alternate transformation that predicts absolute simultaneity, the absolute Lorentz transformation. Here, we describe how published optical tests of light speed isotropy/anisotropy cannot distinguish between the two transformations. We show that the shared equations of the two transformations, from the perspective of the "stationary" observer, are sufficient to predict null results in optical resonator experiments and in tests of frequency changes in one-way light paths. In an influential 1910 exposition on differential simultaneity, Comstock described how a "stationary" observer would observe different clock readings for spatially-separated "moving" clocks. The difference in clock readings is an integral aspect of differ...

  10. Continuous waves probing in dynamic acoustoelastic testing

    Science.gov (United States)

    Scalerandi, M.; Gliozzi, A. S.; Ait Ouarabi, M.; Boubenider, F.

    2016-05-01

    Consolidated granular media display a peculiar nonlinear elastic behavior, which is normally analysed with dynamic ultrasonic testing exploiting the dependence on amplitude of different measurable quantities, such as the resonance frequency shift, the amount of harmonics generation, or the break of the superposition principle. However, dynamic testing allows measuring effects which are averaged over one (or more) cycles of the exciting perturbation. Dynamic acoustoelastic testing has been proposed to overcome this limitation and allow the determination of the real amplitude dependence of the modulus of the material. Here, we propose an implementation of the approach, in which the pulse probing waves are substituted by continuous waves. As a result, instead of measuring a time-of-flight as a function of the pump strain, we study the dependence of the resonance frequency on the strain amplitude, allowing to derive the same conclusions but with an easier to implement procedure.

  11. Probing the Release of Shocked Material

    Science.gov (United States)

    Polsin, D. N.; Boehly, T. R.; Ivancic, S.; Gregor, M. C.; McCoy, C. A.; Meyerhofer, D. D.; Fratanduono, D. E.; Celliers, P. M.

    2015-11-01

    The behavior of shocked material as it releases to lower pressures is important for equation-of-state experiments and inertial confinement fusion research. We present results of experiments that used a 10-ps, 263-nm probe beam to image the release plumes of various target material shocked to multi-megabar pressures by the OMEGA EP laser. One-dimensional streaked x-ray radiography also provided a time-resolved trajectory of the release wave. Simultaneous VISAR (velocity interferometer system for any reflector) measurements provide the initial shocked state from which these materials release. Models for the optical properties of the released material is presented. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0001944.

  12. Probing neutrinoless double beta decay with SNO+

    CERN Document Server

    Arushanova, Evelina

    2015-01-01

    Probing neutrinoless double beta decay is one of the primary goals for SNO+, SNOLAB's multi-purpose neutrino detector. In order to achieve this goal the SNO detector has been adapted so that it can be filled with Te-loaded liquid scintillator. During the initial double beta phase the target loading is 0.3% natural Te, which equates to $\\sim790$ kg of double beta isotope. Estimating the sensitivity to neutrinoless double beta decay requires a well understood background model. For SNO+ this is provided by a comprehensive study considering all possible background contributions, whether they originate from within the liquid scintillator cocktail, the surrounding parts of the detector or other irreducible backgrounds. Given these considerations, for five years running in the initial phase, the expected sensitivity is $T_{1/2}^{0\

  13. Layer resolved capacitive probing of graphene bilayers

    Science.gov (United States)

    Zibrov, Alexander; Parmentier, François; Li, Jia; Wang, Lei; Hunt, Benjamin; Dean, Cory; Hone, James; Taniguchi, Takashi; Watanabe, Kenji; Young, Andrea

    Compared to single layer graphene, graphene bilayers have an additional ``which-layer'' degree of freedom that can be controlled by an external electric field in a dual-gated device geometry. We describe capacitance measurements capable of directly probing this degree of freedom. By performing top gate, bottom gate, and penetration field capacitance measurements, we directly extract layer polarization of both Bernal and twisted bilayers. We will present measurements of hBN encapsulated bilayers at both zero and high magnetic field, focusing on the physics of the highly degenerate zero-energy Landau level in the high magnetic field limit where spin, valley, and layer degeneracy are all lifted by electronic interactions.

  14. Probing Quantum Violations of the Equivalence Principle

    CERN Document Server

    Adunas, G Z; Ahluwalia, D V

    2001-01-01

    The joint realm of quantum mechanics and the general-relativistic description of gravitation is becoming increasingly accessible to terrestrial experiments and observations. In this essay we study the emerging indications of the violation of equivalence principle (VEP). While the solar neutrino anomaly may find its natural explanation in a VEP, the statistically significant discrepancy observed in the gravitationally induced phases of neutron interferometry seems to be the first indication of a VEP. However, such a view would seem immediately challenged by the atomic interferometry results. The latter experiments see no indications of VEP, in apparent contradiction to the neutron interferometry results. Here we present arguments that support the view that these, and related torsion pendulum experiments, probe different aspects of gravity; and that current experimental techniques, when coupled to the solar-neutrino data, may be able to explore quantum mechanically induced violations of the equivalence principl...

  15. Electromagnetic probes in heavy-ion collisions

    Directory of Open Access Journals (Sweden)

    van Hees H.

    2015-01-01

    Full Text Available Due to their penetrating nature, electromagnetic probes, i.e., lepton-antilepton pairs (dileptons and photons are unique tools to gain insight into the nature of the hot and dense medium of strongly-interacting particles created in relativistic heavy-ion collisions, including hints to the nature of the restoration of chiral symmetry of QCD. Of particular interest are the spectral properties of the electromagnetic current-correlation function of these particles within the dense and/or hot medium. The related theoretical investigations of the in-medium properties of the involved particles in both the partonic and hadronic part of the QCD phase diagram underline the importance of a proper understanding of the properties of various hadron resonances in the medium.

  16. Probing SZ Source Detection with Gasdynamical Simulations

    CERN Document Server

    Bond, J R; Wadsley, J W; Gladders, M D; Ruetalo, Marcelo I.; Wadsley, James W.; Gladders, Michael D.

    2001-01-01

    The huge worldwide investment in CMB experiments should make the Sunyaev-Zeldovich (SZ) effect a key probe of the cosmic web in the near future. For the promise to be realized, substantial development of simulation and analysis tools to relate observation to theory is needed. The high nonlinearity and dissipative/feedback gas physics lead to highly non-Gaussian patterns that are much more difficult to analyze than Gaussian primary anisotropies for which the procedures are reasonably well developed. Historical forecasts for what CMB experiments might see used semi-analytic tools, including large scale map constructions, with localized and simplified pressure structures distributed on a point process of (clustered) sources. Hydro studies beyond individual cluster/supercluster systems were inadequate, but now large-volume simulations with high resolution are beginning to shift the balance. We illustrate this by applying ``Gasoline'' (parallelized Tree+SPH) computations to construct SZ maps and derive statistical...

  17. Hard Probes in Heavy-Ion Physics

    CERN Document Server

    Renk, Thorsten

    2012-01-01

    The aim of ultrarelativistic heavy ion physics is to study collectivity and thermodynamics of Quantum Chromodynamics (QCD) by creating a transient small volume of matter with extreme density and temperature. There is experimental evidence that most of the particles created in such a collision form indeed a thermalized system characterized by collective response to pressure gradients. However, a numerically small subset of high transverse momentum ($P_T$) processes takes place independent of the bulk, with the outgoing partons subsequently propagating through the bulk medium. Understanding the modification of such 'hard probes' by the bulk medium is an important part of the efforts to determine the properties of hot and dense QCD matter. In this paper, current developments are reviewed.

  18. Preparation of Regular Specimens for Atom Probes

    Science.gov (United States)

    Kuhlman, Kim; Wishard, James

    2003-01-01

    A method of preparation of specimens of non-electropolishable materials for analysis by atom probes is being developed as a superior alternative to a prior method. In comparison with the prior method, the present method involves less processing time. Also, whereas the prior method yields irregularly shaped and sized specimens, the present developmental method offers the potential to prepare specimens of regular shape and size. The prior method is called the method of sharp shards because it involves crushing the material of interest and selecting microscopic sharp shards of the material for use as specimens. Each selected shard is oriented with its sharp tip facing away from the tip of a stainless-steel pin and is glued to the tip of the pin by use of silver epoxy. Then the shard is milled by use of a focused ion beam (FIB) to make the shard very thin (relative to its length) and to make its tip sharp enough for atom-probe analysis. The method of sharp shards is extremely time-consuming because the selection of shards must be performed with the help of a microscope, the shards must be positioned on the pins by use of micromanipulators, and the irregularity of size and shape necessitates many hours of FIB milling to sharpen each shard. In the present method, a flat slab of the material of interest (e.g., a polished sample of rock or a coated semiconductor wafer) is mounted in the sample holder of a dicing saw of the type conventionally used to cut individual integrated circuits out of the wafers on which they are fabricated in batches. A saw blade appropriate to the material of interest is selected. The depth of cut and the distance between successive parallel cuts is made such that what is left after the cuts is a series of thin, parallel ridges on a solid base. Then the workpiece is rotated 90 and the pattern of cuts is repeated, leaving behind a square array of square posts on the solid base. The posts can be made regular, long, and thin, as required for samples

  19. Probing cellular behaviors through nanopatterned chitosan membranes

    International Nuclear Information System (INIS)

    This paper describes a high-throughput method for developing physically modified chitosan membranes to probe the cellular behavior of MDCK epithelial cells and HIG-82 fibroblasts adhered onto these modified membranes. To prepare chitosan membranes with micro/nanoscaled features, we have demonstrated an easy-to-handle, facile approach that could be easily integrated with IC-based manufacturing processes with mass production potential. These physically modified chitosan membranes were observed by scanning electron microscopy to gain a better understanding of chitosan membrane surface morphology. After MDCK cells and HIG-82 fibroblasts were cultured on these modified chitosan membranes for various culture durations (i.e. 1, 2, 4, 12 and 24 h), they were investigated to decipher cellular behavior. We found that both cells preferred to adhere onto a flat surface rather than on a nanopatterned surface. However, most (> 80%) of the MDCK cells showed rounded morphology and would suspend in the cultured medium instead of adhering onto the planar surface of negatively nanopatterned chitosan membranes. This means different cell types (e.g. fibroblasts versus epithelia) showed distinct capabilities/preferences of adherence for materials of varying surface roughness. We also showed that chitosan membranes could be re-used at least nine times without significant contamination and would provide us consistency for probing cell–material interactions by permitting reuse of the same substrate. We believe these results would provide us better insight into cellular behavior, specifically, microscopic properties and characteristics of cells grown under unique, nanopatterned cell-interface conditions. (paper)

  20. The GalileoJupiter Probe Doppler Wind Experiment

    Science.gov (United States)

    Atkinson, D. H.

    2001-09-01

    The GalileoJupiter atmospheric entry probe was launched along with the Galileoorbiter spacecraft from Cape Canaveral in Florida, USA, on October 18, 1989. Following a cruise of greater than six years, the probe arrived at Jupiter on December 7, 1995. During its 57-minute descent, instruments on the probe studied the atmospheric composition and structure, the clouds, lightning, and energy structure of the upper Jovian atmosphere. One of the two radio channels over which the experiment data was transmitted to the orbiter was driven by an ultrastable oscillator. All motions of the probe and orbiter, including the speed of probe descent, Jupiter's rotation, and the atmospheric winds, contributed to a Doppler shift of the probe radio frequency. By accurately measuring the frequency of the probe radio signal, an accurate time history of the probe-orbiter relative motions could be reconstructed. Knowledge of the nominal probe and orbiter trajectories allowed the nominal Doppler shift to be removed from the probe radio frequency leaving a measurable frequency residual arising primarily from the zonal winds in Jupiter's atmosphere, and micromotions of the probe arising from probe spin, swing under the parachute, atmospheric turbulence, and aerodynamic effects. Assuming that the zonal horizontal winds dominate the residual probe motion, a profile of frequency residuals was generated. Inversion of the frequency residuals resulted in the first in situ measurements of the vertical profile of Jupiter's deep zonal winds. It is found that beneath 700 mb, the winds are strong and prograde, rising rapidly to 170 m/s between 1 and 4 bars. Beneath 4 bars to 21 bars, the depth at which the link with the probe was lost, the winds remain constant and strong. When corrections for the high temperatures encountered by the probe are considered, there is no evidence of diminishing or strengthening of the zonal winds in the deepest regions explored by the Galileoprobe. Following the wind

  1. The Experimental Probe of Inflationary Cosmology (EPIC): A Mission Concept Study for NASA's Einstein Inflation Probe

    CERN Document Server

    Bock, James; Hanany, Shaul; Keating, Brian; Lee, Adrian; Matsumura, Tomotake; Milligan, Michael; Ponthieu, Nicolas; Renbarger, Tom; Tran, Huan

    2008-01-01

    This is the Phase 1 Report on the Experimental Probe of Inflationary Cosmology (EPIC), a mission concept study for NASA's Einstein Inflation Probe. When we began our study we sought to answer five fundamental implementation questions: 1) can foregrounds be measured and subtracted to a sufficiently low level?; 2) can systematic errors be controlled?; 3) can we develop optics with sufficiently large throughput, low polarization, and frequency coverage from 30 to 300 GHz?; 4) is there a technical path to realizing the sensitivity and systematic error requirements?; and 5) what are the specific mission architecture parameters, including cost? Detailed answers to these questions are contained in this report. Currently in Phase 2, we are exploring a mission concept targeting a ~2m aperture, in between the two options described in the current report with a small (~30 cm) and large (~4m) missions.

  2. Monte Carlo modeling of ultrasound probes for image guided radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Bazalova-Carter, Magdalena, E-mail: bazalova@uvic.ca [Department of Radiation Oncology, Stanford University, Stanford, California 94305 and Department of Physics and Astronomy, University of Victoria, Victoria, British Columbia V8W 2Y2 (Canada); Schlosser, Jeffrey [SoniTrack Systems, Inc., Palo Alto, California 94304 (United States); Chen, Josephine [Department of Radiation Oncology, UCSF, San Francisco, California 94143 (United States); Hristov, Dimitre [Department of Radiation Oncology, Stanford University, Stanford, California 94305 (United States)

    2015-10-15

    Purpose: To build Monte Carlo (MC) models of two ultrasound (US) probes and to quantify the effect of beam attenuation due to the US probes for radiation therapy delivered under real-time US image guidance. Methods: MC models of two Philips US probes, an X6-1 matrix-array transducer and a C5-2 curved-array transducer, were built based on their megavoltage (MV) CT images acquired in a Tomotherapy machine with a 3.5 MV beam in the EGSnrc, BEAMnrc, and DOSXYZnrc codes. Mass densities in the probes were assigned based on an electron density calibration phantom consisting of cylinders with mass densities between 0.2 and 8.0 g/cm{sup 3}. Beam attenuation due to the US probes in horizontal (for both probes) and vertical (for the X6-1 probe) orientation was measured in a solid water phantom for 6 and 15 MV (15 × 15) cm{sup 2} beams with a 2D ionization chamber array and radiographic films at 5 cm depth. The MC models of the US probes were validated by comparison of the measured dose distributions and dose distributions predicted by MC. Attenuation of depth dose in the (15 × 15) cm{sup 2} beams and small circular beams due to the presence of the probes was assessed by means of MC simulations. Results: The 3.5 MV CT number to mass density calibration curve was found to be linear with R{sup 2} > 0.99. The maximum mass densities in the X6-1 and C5-2 probes were found to be 4.8 and 5.2 g/cm{sup 3}, respectively. Dose profile differences between MC simulations and measurements of less than 3% for US probes in horizontal orientation were found, with the exception of the penumbra region. The largest 6% dose difference was observed in dose profiles of the X6-1 probe placed in vertical orientation, which was attributed to inadequate modeling of the probe cable. Gamma analysis of the simulated and measured doses showed that over 96% of measurement points passed the 3%/3 mm criteria for both probes placed in horizontal orientation and for the X6-1 probe in vertical orientation. The

  3. Field emission sensing for non-contact probe recording

    NARCIS (Netherlands)

    Febre, le Alexander Jonathan

    2008-01-01

    In probe recording an array of thousands of nanometer-sharp probes is used to write and read on a storage medium. By using micro-electromechanical system technology (MEMS) for fabrication, small form factor memories with high data density and low power consumption can be obtained. Such a system is e

  4. Analytical investigation into the resonance frequencies of a curling probe

    Science.gov (United States)

    Arshadi, Ali; Brinkmann, Ralf Peter

    2016-08-01

    The term ‘active plasma resonance spectroscopy’ (APRS) denotes a class of closely related plasma diagnostic methods which utilize the natural ability of plasmas to resonate on or near the electron plasma frequency {ω\\text{pe}} ; an electrical radio frequency signal (in the GHz range) is coupled into the plasma via an antenna or a probe, the spectral response is recorded and a mathematical model is employed to determine plasma parameters such as the plasma density and the electron temperature. The curling probe, recently invented by Liang et al (2011 Appl. Phys. Express 4 066101), is a novel realization of the APRS concept which has many practical advantages. In particular, it can be miniaturized and flatly embedded into the chamber wall, thus allowing the monitoring of plasma processes without contamination nor disturbance. Physically, the curling probe can be understood as a ‘coiled’ form of the hairpin probe (Stenzel 1976 Rev. Sci. Instrum. 47 603). Assuming that the spiralization of the probe has little electrical effect, this paper investigates the characteristcs of a ‘straightened’ curling probe by modeling it as an infinite slot-type resonator that is in direct contact with the plasma. The diffraction of an incident plane wave at the slot is calculated by solving the cold plasma model and Maxwell’s equations simultaneously. The resonance frequencies of the probe are derived and are found to be in good agreement with the numerical results of the probe inventors.

  5. Probing CP violation with T2K, NO$\

    CERN Document Server

    Dutta, Debajyoti

    2016-01-01

    The presence of non-unitary neutrino mixing can affect the measurement of the three-neutrino leptonic Dirac CP phase and hamper efforts to probe CP violation due to degeneracies of the extra non-unitary CP phase with the standard CP phase. We study the effect of including non-unitarity on probing CP violation with the long-baseline experiments NO$\

  6. Improved controlled atmosphere high temperature scanning probe microscope

    DEFF Research Database (Denmark)

    Hansen, Karin Vels; Wu, Yuehua; Jacobsen, Torben;

    2013-01-01

    fuel cells and electrolyzer cells. Here, we report on advanced improvements of our original controlled atmosphere high temperature scanning probe microscope, CAHT-SPM. The new microscope can employ a broad range of the scanning probe techniques including tapping mode, scanning tunneling microscopy...

  7. Soft-landing deposition of radioactive probe atoms on surfaces

    NARCIS (Netherlands)

    Laurens, C.R; Rosu, M.F; Pleiter, F; Niesen, L

    1999-01-01

    We present a method to deposit a wide range of radioactive probe atoms on surfaces, without introducing lattice damage or contaminating the surface with other elements or isotopes. In this method, the probe atoms are mass-separated using an isotope separa-tor, decelerated to 5 eV, and directly depos

  8. Helium ion beam induced growth of hammerhead AFM probes

    NARCIS (Netherlands)

    Nanda, G.; Van Veldhoven, E.; Maas, D.; Sadeghian, H.; Alkemade, P.F.A.

    2015-01-01

    The authors report the direct-write growth of hammerhead atomic force microscope(AFM) probes by He+beam induced deposition of platinum-carbon. In order to grow a thin nanoneedle on top of a conventional AFM probe, the authors move a focused He+beam during exposure to a PtC precursor gas. In the fina

  9. Helium ion beam induced growth of hammerhead AFM probes

    NARCIS (Netherlands)

    Nanda, G.; Veldhoven, E. van; Maas, D.J.; Sadeghian Marnani, H.; Alkemade, P.F.A.

    2015-01-01

    The authors report the direct-write growth of hammerhead atomic force microscope (AFM) probes by He+ beam induced deposition of platinum-carbon. In order to grow a thin nanoneedle on top of a conventional AFM probe, the authors move a focused He+ beam during exposure to a PtC precursor gas. In the f

  10. Scanning Probe Microscopy at 650 °C in Air

    OpenAIRE

    Hansen, Karin Vels; Jacobsen, Torben; Nørgaard, Anne-Mette; Ohmer, N.; Mogensen, Mogens Bjerg

    2009-01-01

    The controlled atmosphere high temperature scanning probe microscope was designed to study the electrical properties of surfaces at elevated temperatures by using the probe as an electrode. The capability of a simultaneous acquisition of topographical and electrical data for the same surface area at 650°C is demonstrated on several samples.

  11. On the Cell Probe Complexity of Membership and Perfect Hashing

    DEFF Research Database (Denmark)

    Pagh, Rasmus

    2001-01-01

    We study two fundamental static data structure problems, membership and perfect hashing, in Yao's cell probe model. The first space and bit probe optimal worst case upper bound is given for the membership problem. We also give a new efficient membership scheme where the query algorithm makes just...

  12. In-flight calibration of mesospheric rocket plasma probes.

    Science.gov (United States)

    Havnes, Ove; Hartquist, Thomas W; Kassa, Meseret; Morfill, Gregor E

    2011-07-01

    Many effects and factors can influence the efficiency of a rocket plasma probe. These include payload charging, solar illumination, rocket payload orientation and rotation, and dust impact induced secondary charge production. As a consequence, considerable uncertainties can arise in the determination of the effective cross sections of plasma probes and measured electron and ion densities. We present a new method for calibrating mesospheric rocket plasma probes and obtaining reliable measurements of plasma densities. This method can be used if a payload also carries a probe for measuring the dust charge density. It is based on that a dust probe's effective cross section for measuring the charged component of dust normally is nearly equal to its geometric cross section, and it involves the comparison of variations in the dust charge density measured with the dust detector to the corresponding current variations measured with the electron and/or ion probes. In cases in which the dust charge density is significantly smaller than the electron density, the relation between plasma and dust charge density variations can be simplified and used to infer the effective cross sections of the plasma probes. We illustrate the utility of the method by analysing the data from a specific rocket flight of a payload containing both dust and electron probes.

  13. The positioning device of beam probes for accelerator LUE-200

    International Nuclear Information System (INIS)

    The description of a device for the positioning of sliding beam probes which is the part of the beam diagnostic system for the LUE-200 electron linac of IREN installation is presented. The device provides remote control of input-output operation of beam probes of five diagnostic stations established in an accelerating tract and in the beam transportation channel of the accelerator

  14. Extreme Environments Technologies for Probes to Venus and Jupiter

    Science.gov (United States)

    Balint, Tibor S.; Kolawa, Elizabeth A.; Peterson, Craig E.; Cutts, James A.; Belz, Andrea P.

    2007-01-01

    This viewgraph presentation reviews the technologies that are used to mitigate extreme environments for probes at Venus and Jupiter. The contents include: 1) Extreme environments at Venus and Jupiter; 2) In-situ missions to Venus and Jupiter (past/present/future); and 3) Approaches to mitigate conditions of extreme environments for probes with systems architectures and technologies.

  15. Probing structural changes of self assembled i-motif DNA

    KAUST Repository

    Lee, Iljoon

    2015-01-01

    We report an i-motif structural probing system based on Thioflavin T (ThT) as a fluorescent sensor. This probe can discriminate the structural changes of RET and Rb i-motif sequences according to pH change. This journal is

  16. Fabrication of an all-metal atomic force microscope probe

    DEFF Research Database (Denmark)

    Rasmussen, Jan Pihl; Tang, Peter Torben; Hansen, Ole;

    1997-01-01

    This paper presents a method for fabrication of an all-metal atomic force microscope probe (tip, cantilever and support) for optical read-out, using a combination of silicon micro-machining and electroforming. The paper describes the entire fabrication process for a nickel AFM-probe. In addition...

  17. Correction of nonlinear lateral distortions of scanning probe microscopy images.

    Science.gov (United States)

    Schnedler, M; Weidlich, P H; Portz, V; Weber, D; Dunin-Borkowski, R E; Ebert, Ph

    2014-01-01

    A methodology for the correction of scanning probe microscopy image distortions is demonstrated. It is based on the determination of displacement vectors from the measurement of a calibration sample. By moving the pixels of the distorted scanning probe microscopy image along the displacement vectors an almost complete correction of the nonlinear, time independent distortions is achieved. PMID:24013615

  18. Novel rotating field probe for inspection of tubes

    Science.gov (United States)

    Xin, J.; Tarkleson, E.; Lei, N.; Udpa, L.; Udpa, S. S.

    2012-05-01

    Inspection of steam generator tubes in nuclear power plants is extremely critical for safe operation of the power plant. In the nuclear industry, steam generator tube inspection using eddy current techniques has evolved over the years from a single bobbin coil, to rotating probe coil (RPC) and array probe, in an attempt to improve the speed and reliability of inspection. The RPC probe offers the accurate spatial resolution but involves complex mechanical rotation. This paper presents a novel design of eddy current probes based on rotating fields produced by three identical coils excited by a balanced three-phase supply. The sensor thereby achieves rotating probe functionality by electronic means and eliminates the need for mechanical rotation. The field generated by the probe is largely radial that result in induced currents that flow circularly around the radial axis and rotating around the tube at a synchronous speed effectively producing induced eddy currents that are multidirectional. The probe will consequently be sensitive to cracks of all orientations in the tube wall. The finite element model (FEM) results of the rotating fields and induced currents are presented. A prototype probe is being built to validate simulation results.

  19. Capacitance and effective area of flush monopole probes.

    Energy Technology Data Exchange (ETDEWEB)

    Warne, Larry Kevin; Johnson, William Arthur; Morris, Marvin E.; Basilio, Lorena I.; Lehr, Jane Marie; Higgins, Matthew B.

    2004-08-01

    Approximate formulas are constructed and numerical simulations are carried out for electric field derivative probes that have the form of flush mounted monopoles. Effects such as rounded edges are included. A method is introduced to make results from two-dimensional conformal mapping analyses accurately apply to the three-dimensional axisymmetric probe geometry

  20. Scanning Probe Microscopy at 650 °C in Air

    DEFF Research Database (Denmark)

    Hansen, Karin Vels; Jacobsen, Torben; Nørgaard, Anne-Mette;

    2009-01-01

    The controlled atmosphere high temperature scanning probe microscope was designed to study the electrical properties of surfaces at elevated temperatures by using the probe as an electrode. The capability of a simultaneous acquisition of topographical and electrical data for the same surface area...

  1. Amplification of target-specific, ligation-dependent circular probe.

    Science.gov (United States)

    Zhang, D Y; Brandwein, M; Hsuih, T C; Li, H

    1998-05-12

    We describe a novel polymerase chain reaction (PCR)-based gene amplification method utilizing a circularizable oligodeoxyribonucleotide probe (C-probe). The C-probe contains two target complementary regions located at each terminus and an interposed generic PCR primer binding region. The hybridization of C-probe to a target brings two termini in direct apposition as the complementary regions of C-probe wind around the target to form a double helix. Subsequent ligation of the two termini results in a covalently linked C-probe that becomes 'locked on to' the target. The circular nature of the C-probe allows for the generation of a multimeric single-stranded DNA (ssDNA) via extension of the antisense primer by Taq DNA polymerase along the C-probe and displacement of downstream strand, analogous to 'rolling circle' replication of bacteriophage in vivo. This multimeric ssDNA then serves as a template for multiple sense primers to hybridize, extend, and displace downstream DNA, generating a large ramified (branching) DNA complex. Subsequent thermocycling denatures the dsDNA and initiates the next round of primer extension and ramification. This model results in significantly improved amplification kinetics (super-exponential) as compared to conventional PCR. Our results show that the C-probe was 1000 times more sensitive than the corresponding linear hemiprobes for detecting Epstein-Barr virus early RNA. The C-probe not only increases the power of amplification but also offers a means for decontaminating carryover amplicons. As the ligated C-probes possess no free termini, they are resistant to exonuclease digestion, whereas contaminated linear amplicons are susceptible to digestion. Treatment of the ligation reaction mixture with exonuclease prior to amplification eliminated the amplicon contaminant, which could also have been co-amplified with the same PCR primers; only the ligated C-probes were amplified. The combined advantages of the C-probe and thermocycling have a

  2. Ultrathin lensed fiber-optic probe for optical coherence tomography.

    Science.gov (United States)

    Qiu, Y; Wang, Y; Belfield, K D; Liu, X

    2016-06-01

    We investigated and validated a novel method to develop ultrathin lensed fiber-optic (LFO) probes for optical coherence tomography (OCT) imaging. We made the LFO probe by attaching a segment of no core fiber (NCF) to the distal end of a single mode fiber (SMF) and generating a curved surface at the tip of the NCF using the electric arc of a fusion splicer. The novel fabrication approach enabled us to control the length of the NCF and the radius of the fiber lens independently. By strategically choosing these two parameters, the LFO probe could achieve a broad range of working distance and depth of focus for different OCT applications. A probe with 125μm diameter and lateral resolution up to 10μm was demonstrated. The low-cost, disposable and robust LFO probe is expected to have great potential for interstitial OCT imaging. PMID:27375934

  3. Biomedical probe using a fiber-optic coupled scintillator.

    Science.gov (United States)

    Swinth, K L; Ewins, J H

    1976-01-01

    A high-sensitivity biomedical radiation probe which employs a fiber-optic coupled NaI(Tl) scintillator as a detector is described. It was developed for in vivo counting of low-energy 239Pu photons from material located in the tracheobronchial lymph nodes.-This probe is 20 times as sensitive as a solid-state probe (avalanche diode) previously developed for this application. Tests with 99mTc show a sensitivity more than 90 times greater than biomedical probes using DcTe of GaAs; however, the improved sensitivity is largely due to an increased sensitive volume. Probes were evaluated in animals and phantoms for detection of 239Pu and for location of lung tumors labeled with 111In. PMID:1264039

  4. Gold nanoparticle-coated biomaterial as SERS micro-probes

    Indian Academy of Sciences (India)

    G V Pavan Kumar

    2011-06-01

    We report for the first time, on the utility of plant-based biomaterial as enhanced-Raman scattering probes. The bio-substrate used in this study are commonly found in plant extracts, and are cost-effective, mechanically robust, flexible and easily transportable. The probe was fabricated by coating the plant extract with gold nanoparticles and characterized. By employing a ‘single-touch contact’ method, we reveal the ability of these probes to detect routinely used Raman markers such as 2-napthalenethiol and rhodamine B, at nano-molar concentrations, in dry and liquid forms, respectively. Reproducibility of the signals with variation <5%, and the ability to detect biomolecules are demonstrated herein. We envision these bio-probes as potential candidates for enhanced Raman sensing in chemical, environmental, and archaeological applications. By further engineering the shape, morphology, and surface chemistry of these micro-probes, we foresee their utility as miniaturized, natural SERS substrates.

  5. Maximizing information on the environment by dynamically controlled qubit probes

    CERN Document Server

    Zwick, Analia; Kurizki, Gershon

    2015-01-01

    We explore the ability of a qubit probe to characterize unknown parameters of its environment. By resorting to quantum estimation theory, we analytically find the ultimate bound on the precision of estimating key parameters of a broad class of ubiquitous environmental noises ("baths") which the qubit may probe. These include the probe-bath coupling strength, the correlation time of generic bath spectra, the power laws governing these spectra, as well as their dephasing times T2. Our central result is that by optimizing the dynamical control on the probe under realistic constraints one may attain the maximal accuracy bound on the estimation of these parameters by the least number of measurements possible. Applications of this protocol that combines dynamical control and estimation theory tools to quantum sensing are illustrated for a nitrogen-vacancy center in diamond used as a probe.

  6. Vertical probe-induced asymmetric dust oscillation in complex plasma

    CERN Document Server

    Harris, Brandon J; Hyde, Truell W

    2013-01-01

    Spherical, micrometer-sized particles within a Coulomb crystal levitated in the sheath above the powered lower electrode in a GEC reference cell are perturbed using a Zyvex S100 Nanomanipulator. Using the S100, a vertical probe is positioned within the cell at various locations with respect to the crystal formed within the sheath. As the probe is lowered toward the horizontal plane of the dust layer, a circular cavity opens in the center of the crystal and expands. To explore the minimally perturbative state, the probe is lifted to the position that closes this cavity, the probe potential is oscillated, and the motion of the particle directly beneath the probe is analyzed. Using a simple electric field model for the plasma sheath, the change predicted in the levitation height is compared with experiment.

  7. Ultrathin lensed fiber-optic probe for optical coherence tomography.

    Science.gov (United States)

    Qiu, Y; Wang, Y; Belfield, K D; Liu, X

    2016-06-01

    We investigated and validated a novel method to develop ultrathin lensed fiber-optic (LFO) probes for optical coherence tomography (OCT) imaging. We made the LFO probe by attaching a segment of no core fiber (NCF) to the distal end of a single mode fiber (SMF) and generating a curved surface at the tip of the NCF using the electric arc of a fusion splicer. The novel fabrication approach enabled us to control the length of the NCF and the radius of the fiber lens independently. By strategically choosing these two parameters, the LFO probe could achieve a broad range of working distance and depth of focus for different OCT applications. A probe with 125μm diameter and lateral resolution up to 10μm was demonstrated. The low-cost, disposable and robust LFO probe is expected to have great potential for interstitial OCT imaging.

  8. Scanning probe and micropatterning approaches for biomolecular screening applications

    CERN Document Server

    Wilde, L M

    2002-01-01

    Force mapping using atomic force microscopy (AFM) allows for the simultaneous acquisition of topography and probe-sample interaction data. For example, AFM probes functionalised with an antigen can be employed to map the spatial distribution of recognition events on a substrate functionalised with the complementary specific antibody. However, this technique is currently limited to the detection of a single receptor-ligand species. Were the detection of multiple receptor-ligand interactions possible, AFM force mapping would offer greater scope as a sensitive tool for bioassay and screening applications. This thesis outlines developments in probe and substrate immobilisation methods to facilitate this process. We have developed an immobilisation strategy, which allows two antigen species, human serum albumin (HSA) and the beta subunit of human chorionic gonadotropin (beta hCG) to be simultaneously present on an AFM probe. Single point force spectroscopy results have revealed the ability of such probes to discri...

  9. Computerized Langmuir Probe Measurements in a Capacitively Coupled RF Discharge

    CERN Document Server

    Shaer, M El; Massoud, A; Mobasher, M; Wuttmann, M

    2014-01-01

    A system of automated computerized Langmuir probe measurements is used in order to determine the plasma parameters in a plasma reactor constructed for cleaning of metallic artifacts by RF discharge. A compensated probe insures the suppression of the RF interference. The probe data are collected using a commercial data acquisition unit connected to a portable computer. The raw data are processed using wavelet transforms techniques which assures the de-noising of the probe signal without distortion of the probe I-V characteristic. The first and second derivatives of the I-V characteristic are determined. The measurement of the electron density spatial distribution in the inter-electrode distance indicates a flat density profile in the middle region of the discharge.

  10. Interstellar Probe: The Next Step To Flight

    Science.gov (United States)

    McNutt, Ralph; Zurbuchen, Thomas H.

    2016-07-01

    In the years following the discovery of the solar wind, the term "heliosphere" was coined and defined as "the region of interplanetary space where the solar wind is flowing supersonically." In June 1971, with the development of the Pioneer probes to Jupiter and beyond well underway, a session of the American Astronautical Society meeting considered scientific exploration reaching beyond the solar system and into the interstellar medium. Despite many discussions, studies, and meetings since, the most recent held under the auspices of the Keck Institute for Space Studies (8-11 September 2014 and 13-15 January 2015), such missions have been relegated to the '"future" due to the large distances and solar system escape speeds contemplated for their execution. In the meantime, the Voyager Interstellar Mission (VIM), consisting of the twin Voyager spacecraft almost 40 years since their respective launches, are making inroads into this region beyond the termination shock of the solar wind, a new region of the solid bodies of the solar system has been opened by the New Horizons flyby of the Pluto system, and the Cassini Ion and Neutral CAmera (INCA) and Interstellar Boundary Explorer (IBEX) have remotely sensed neutral atoms that have provided significant clues to the global structure of the interaction of the solar wind and interstellar medium. It is now time for a dedicated mission to the regime beyond the solar system to explore our galactic environment. A first, near-term implementation can be carried out with the near-current flight system technology. What is also clear is that the high speeds required will limit the spacecraft to a relatively small mass of no more than ~500 kg, regardless of the propulsion details. The recent success of the New Horizons mission at the Pluto system illustrates that with modern technologies, such spacecraft sizes can still accommodate the means to produce paradigm-shifting science, providing for a compelling scientific mission. The

  11. XPS measurements for probing dynamics of charging

    Energy Technology Data Exchange (ETDEWEB)

    Suzer, Sefik, E-mail: suzer@fen.bilkent.edu.t [Department of Chemistry, Bilkent University, 06800 Ankara (Turkey); Institute of Materials and Nanotechnology, 06800 Ankara (Turkey); Sezen, Hikmet; Ertas, Gulay [Department of Chemistry, Bilkent University, 06800 Ankara (Turkey); Institute of Materials and Nanotechnology, 06800 Ankara (Turkey); Dana, Aykutlu [Institute of Materials and Nanotechnology, 06800 Ankara (Turkey)

    2010-01-15

    The technique of recording X-ray photoemission data while the sample rod is subjected to +-10.0 V (dc) or square-wave pulses (ac) with varying frequencies in the range of 10{sup -3} to 10{sup 3} Hz for probing charging/discharging dynamics of dielectric materials, is reviewed. Application of this technique introduces charging shifts as well as broadening of the peaks, which depend non-linearly on the polarity, as well as on the frequency of the pulses applied. These changes have been measured on: (i) an artificially created dielectric sample consisting of a Au metal strip connected externally to a series resistor of 1 MOMEGA and a parallel capacitor of 56 nF, and two real dielectric films; (ii) a 20 nm organic polystyrene film spin-coated on a silicon substrate; (iii) a 10 nm SiO{sub 2} inorganic layer thermally grown on silicon. A simple circuit model is introduced to simulate the charging shifts and the peak broadenings. Although this simple model faithfully reproduces the charging shifts in all three cases, and also some of the broadenings for the artificial dielectric and the polystyrene film, the additional broadening in the negatively charged peaks of the SiO{sub 2} dielectric film cannot be accounted for. It is also claimed that these experimental findings can be used for extracting material-specific dielectric properties.

  12. Probing interactions between collagen proteins via microrheology

    Science.gov (United States)

    Shayegan, Marjan; Forde, Nancy R.

    2012-10-01

    Collagen is the major structural protein of our connective tissues. It provides integrity and mechanical strength through its hierarchical organization. Defects in collagen can lead to serious connective tissue diseases. Collagen is also widely used as a biomaterial. Given that mechanical properties are related to the structure of materials, the main goal of our research is to understand how molecular structure correlates with microscale mechanical properties of collagen solutions and networks. We use optical tweezers to trap and monitor thermal fluctuations of an embedded probe particle, from which viscoelastic properties of the solution are extracted. We find that elasticity becomes comparable to viscous behavior at collagen concentrations of 5mg/ml. Furthermore, by simultaneously neutralizing pH and adding salt, we observe changes in viscosity and elasticity of the solution over time. We attribute this to the self-assembly process of collagen molecules into fibrils with different mechanical properties. Self-assembly of collagen under these conditions is verified by turbidity measurements as well as electron microscopy. By comparing results from these local studies of viscoelasticity, we can detect spatial heterogeneity of fibril formation throughout the solution.

  13. Probing cosmic plasma with giant radio pulses

    CERN Document Server

    Kondratiev, V I; Soglasnov, V A; Kovalev, Y Y; Bartel, N; Cannon, W; Novikov, A Y

    2007-01-01

    VLBI observations of the Crab pulsar with the 64-m radio telescope at Kalyazin (Russia) and the 46-m radio telescope of the Algonquin Radio Observatory (Canada) at 2.2 GHz and single-dish observations of the millisecond pulsar B1937+21 with the GBT (USA) at 2.1 GHz were conducted to probe the interstellar medium and study the properties of giant pulses. The VLBI data were processed with a dedicated software correlator, which allowed us to obtain the visibility of single giant pulses. Two frequency scales of 50 and 450 kHz were found in the diffraction spectra of giant pulses from the Crab pulsar. The location of the scattering region was estimated to be close to the outer edge of the nebula. No correlation was found between the power spectra of giant pulses at left- and right-hand circular polarization. We explain this lack of correlation through the influence of the strong magnetic field on circularly polarized emission in the region close to the Crab pulsar. Combining the measurement of the decorrelation ba...

  14. Probing catalytic rate enhancement during intramembrane proteolysis.

    Science.gov (United States)

    Arutyunova, Elena; Smithers, Cameron C; Corradi, Valentina; Espiritu, Adam C; Young, Howard S; Tieleman, D Peter; Lemieux, M Joanne

    2016-09-01

    Rhomboids are ubiquitous intramembrane serine proteases involved in various signaling pathways. While the high-resolution structures of the Escherichia coli rhomboid GlpG with various inhibitors revealed an active site comprised of a serine-histidine dyad and an extensive oxyanion hole, the molecular details of rhomboid catalysis were unclear because substrates are unknown for most of the family members. Here we used the only known physiological pair of AarA rhomboid with its psTatA substrate to decipher the contribution of catalytically important residues to the reaction rate enhancement. An MD-refined homology model of AarA was used to identify residues important for catalysis. We demonstrated that the AarA active site geometry is strict and intolerant to alterations. We probed the roles of H83 and N87 oxyanion hole residues and determined that substitution of H83 either abolished AarA activity or reduced the transition state stabilization energy (ΔΔG‡) by 3.1 kcal/mol; substitution of N87 decreased ΔΔG‡ by 1.6-3.9 kcal/mol. Substitution M154, a residue conserved in most rhomboids that stabilizes the catalytic general base, to tyrosine, provided insight into the mechanism of nucleophile generation for the catalytic dyad. This study provides a quantitative evaluation of the role of several residues important for hydrolytic efficiency and oxyanion stabilization during intramembrane proteolysis. PMID:27071148

  15. Probing Compositional Variation within Hybrid Nanostructures

    Energy Technology Data Exchange (ETDEWEB)

    Yuhas, Benjamin D.; Habas, Susan E.; Fakra, Sirine C.; Mokari, Taleb

    2010-06-22

    We present a detailed analysis of the structural and magnetic properties of solution-grown PtCo-CdS hybrid structures in comparison to similar free-standing PtCo alloy nanoparticles. X-ray absorption spectroscopy is utilized as a sensitive probe for identifying subtle differences in the structure of the hybrid materials. We found that the growth of bimetallic tips on a CdS nanorod substrate leads to a more complex nanoparticle structure composed of a PtCo alloy core and thin CoO shell. The core-shell architecture is an unexpected consequence of the different nanoparticle growth mechanism on the nanorod tip, as compared to free growth in solution. Magnetic measurements indicate that the PtCo-CdS hybrid structures are superparamagnetic despite the presence of a CoO shell. The use of X-ray spectroscopic techniques to detect minute differences in atomic structure and bonding in complex nanosystems makes it possible to better understand and predict catalytic or magnetic properties for nanoscale bimetallic hybrid materials.

  16. Probing primordial features with future galaxy surveys

    CERN Document Server

    Ballardini, Mario; Fedeli, Cosimo; Moscardini, Lauro

    2016-01-01

    We study the capability of future measurements of the galaxy clustering power spectrum to probe departures from a power-law spectrum for primordial fluctuations. On considering the information from the galaxy clustering power spectrum up to quasi-linear scales, i.e. $k<0.1$ h Mpc$^{-1}$, we present forecasts for DESI, Euclid and SPHEREx in combination with CMB measurements. As examples of departures in the primordial power spectrum from a simple power-law, we consider four $Planck$ 2015 best-fits motivated by inflationary models with different breaking of the slow-roll approximation. These four representative models provide an improved fit to CMB temperature anisotropies, although not at statistical significant level. As for other extensions in the matter content of the simplest $\\Lambda$CDM model, the complementarity of the information in the resulting matter power spectrum expected from these galaxy surveys and in the primordial power spectrum from CMB anisotropies can be effective in constraining cosmol...

  17. Probing Dark Energy with Constellation-X

    Energy Technology Data Exchange (ETDEWEB)

    Rapetti, David; Allen, Steven W.; /KIPAC, Menlo Park

    2006-09-08

    Constellation-X (Con-X) will carry out two powerful and independent sets of tests of dark energy based on X-ray observations of galaxy clusters, providing comparable accuracy to other leading dark energy probes. The first group of tests will measure the absolute distances to clusters, primarily using measurements of the X-ray gas mass fraction in the largest, dynamically relaxed clusters, but with additional constraining power provided by follow-up observations of the Sunyaev-Zel'dovich (SZ) effect. As with supernovae studies, such data determine the transformation between redshift and true distance, d(z), allowing cosmic acceleration to be measured directly. The second, independent group of tests will use the exquisite spectroscopic capabilities of Con-X to determine scaling relations between X-ray observables and mass. Together with forthcoming X-ray and SZ cluster surveys, these data will help to constrain the growth of structure, which is also a strong function of cosmological parameters.

  18. Probing multimode squeezing with correlation functions

    International Nuclear Information System (INIS)

    Broadband multimode squeezers constitute a powerful quantum resource with promising potential for different applications in quantum information technologies such as information coding in quantum communication networks or quantum simulations in higher-dimensional systems. However, the characterization of a large array of squeezers that coexist in a single spatial mode is challenging. In this paper, we address this problem and propose a straightforward method for determining the number of squeezers and their respective squeezing strengths by using broadband multimode correlation function measurements. These measurements employ the large detection windows of the state of the art avalanche photodiodes in order to simultaneously probe the full Hilbert space of the generated state, which enables us to benchmark the squeezed states. Moreover, due to the structure of correlation functions, our measurements are not affected by losses. This is a significant advantage, since detectors with low efficiencies are sufficient. Our approach is less costly than tomographic methods relying on multimode homodyne detection, which is based on much more demanding measurement and analysis tools and appear to be impractical for large Hilbert spaces.

  19. VLBI FOR GRAVITY PROBE B. I. OVERVIEW

    Energy Technology Data Exchange (ETDEWEB)

    Shapiro, I. I.; Lebach, D. E.; Ratner, M. I. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Bartel, N.; Bietenholz, M. F.; Ransom, R. R. [Department of Physics and Astronomy, York University, 4700 Keele Street, Toronto, ON, M3J 1P3 (Canada); Lestrade, J.-F. [Observatoire de Paris, Centre National de la Recherche Scientifique, 77 Av. Denfert Rochereau, 75014 Paris (France)

    2012-07-01

    We describe the NASA/Stanford gyroscope relativity mission, Gravity Probe B (GP-B), and provide an overview of the following series of six astrometric and astrophysical papers that report on our radio observations and analyses made in support of this mission. The main goal of this 8.5 year program of differential very long baseline interferometry astrometry was to determine the proper motion of the guide star of the GP-B mission, the RS CVn binary IM Pegasi (IM Peg; HR 8703). This proper motion is determined with respect to compact, extragalactic reference sources. The results are -20.833 {+-} 0.090 mas yr{sup -1} and -27.267 {+-} 0.095 mas yr{sup -1} for, respectively, the right ascension and declination, in local Cartesian coordinates, of IM Peg's proper motion, and 10.370 {+-} 0.074 mas (i.e., 96.43 {+-} 0.69 pc) for its parallax (and distance). Each quoted uncertainty is meant to represent an {approx}70% confidence interval that includes the estimated contribution from systematic error. These results are accurate enough not to discernibly degrade the GP-B estimates of its gyroscopes' relativistic precessions: the frame-dragging and geodetic effects.

  20. Capacitance Probe Resonator for Multichannel Electrometer

    Science.gov (United States)

    Blaes, Brent R.; Schaefer, Rembrandt T> Glaser, Robert J.

    2012-01-01

    A multichannel electrometer voltmeter has been developed that employs a mechanical resonator with voltage-sensing capacitance-probe electrodes that enable high-impedance, high-voltage, radiation-hardened measurement of an Internal Electrostatic Discharge Monitor (IESDM) sensor. The IESDM is new sensor technology targeted for integration into a Space Environmental Monitor (SEM) subsystem used for the characterization and monitoring of deep dielectric charging on spacecraft. The resonator solution relies on a non-contact, voltage-sensing, sinusoidal-varying capacitor to achieve input impedances as high as 10 petaohms as determined by the resonator materials, geometries, cleanliness, and construction. The resonator is designed with one dominant mechanical degree of freedom, so it resonates as a simple harmonic oscillator and because of the linearity of the variable sense capacitor to displacement, generates a pure sinusoidal current signal for a fixed input voltage under measurement. This enables the use of an idealized phase-lock sensing scheme for optimal signal detection in the presence of noise.

  1. Chemical probe development versus drug development.

    Science.gov (United States)

    Jackson, Michael R

    2013-01-01

    Phosphatases as a class of proteins have recently attracted significant attention from the pharmaceutical industry. As our knowledge of this diverse family of proteins has grown, the relationship between phosphatases and human disease has clearly been established, with model systems proving much validation for the potential of some members of this family to be candidate drug targets. This, coupled with the fact that there have been a flood of successful drug development efforts over the past 10 years targeting protein kinases, has led some to propose that phosphatases as a class of enzymes might be equally as rich a source of drug targets as kinases. However to date there remain relatively few molecules targeting protein phosphatases in clinical development. This is less a reflection of their importance in key processes associated with disease, but rather seems to reflect inherent issues with developing drugs for many members of this family. This seems especially so for intracellular phosphatases where the development of selective, potent cell penetrant molecules with good drug-like properties has proven a formidable challenge. This chapter provides a brief outline of the two major processes that have resulted in the existing armament of chemical modulators of protein phosphatases, namely, chemical probe development and drug development. These two processes initially seem to be rather similar and while they do overlap, the stated goals of the two approaches at project initiation are distinct. PMID:23860644

  2. Standardless quantification methods in electron probe microanalysis

    Energy Technology Data Exchange (ETDEWEB)

    Trincavelli, Jorge, E-mail: trincavelli@famaf.unc.edu.ar [Facultad de Matemática, Astronomía y Física, Universidad Nacional de Córdoba, Ciudad Universitaria, 5000 Córdoba (Argentina); Instituto de Física Enrique Gaviola, Consejo Nacional de Investigaciones Científicas y Técnicas de la República Argentina, Medina Allende s/n, Ciudad Universitaria, 5000 Córdoba (Argentina); Limandri, Silvina, E-mail: s.limandri@conicet.gov.ar [Facultad de Matemática, Astronomía y Física, Universidad Nacional de Córdoba, Ciudad Universitaria, 5000 Córdoba (Argentina); Instituto de Física Enrique Gaviola, Consejo Nacional de Investigaciones Científicas y Técnicas de la República Argentina, Medina Allende s/n, Ciudad Universitaria, 5000 Córdoba (Argentina); Bonetto, Rita, E-mail: bonetto@quimica.unlp.edu.ar [Centro de Investigación y Desarrollo en Ciencias Aplicadas Dr. Jorge Ronco, Consejo Nacional de Investigaciones Científicas y Técnicas de la República Argentina, Facultad de Ciencias Exactas, de la Universidad Nacional de La Plata, Calle 47 N° 257, 1900 La Plata (Argentina)

    2014-11-01

    The elemental composition of a solid sample can be determined by electron probe microanalysis with or without the use of standards. The standardless algorithms are quite faster than the methods that require standards; they are useful when a suitable set of standards is not available or for rough samples, and also they help to solve the problem of current variation, for example, in equipments with cold field emission gun. Due to significant advances in the accuracy achieved during the last years, product of the successive efforts made to improve the description of generation, absorption and detection of X-rays, the standardless methods have increasingly become an interesting option for the user. Nevertheless, up to now, algorithms that use standards are still more precise than standardless methods. It is important to remark, that care must be taken with results provided by standardless methods that normalize the calculated concentration values to 100%, unless an estimate of the errors is reported. In this work, a comprehensive discussion of the key features of the main standardless quantification methods, as well as the level of accuracy achieved by them is presented. - Highlights: • Standardless methods are a good alternative when no suitable standards are available. • Their accuracy reaches 10% for 95% of the analyses when traces are excluded. • Some of them are suitable for the analysis of rough samples.

  3. Tidal Debris as a Dark Matter Probe

    CERN Document Server

    Johnston, Kathryn V

    2016-01-01

    Tidal debris streams from galaxy satellites can provide insight into the dark matter distribution in halos. This is because we have more information about stars in a debris structure than about a purely random population of stars: we know that in the past they were all bound to the same dwarf galaxy; and we know that they form a dynamically cold population moving on similar orbits. They also probe a different region of the matter distribution in a galaxy than many other methods of mass determination, as their orbits take them far beyond the typical extent of those for the bulk of stars. Although conclusive results from this information have yet to be obtained, significant progress has been made in developing the methodologies for determining both the global mass distribution of the Milky Way's dark matter halo and the amount of dark matter substructure within it. Methods for measuring the halo shape are divided into "predictive methods," which predict the tidal debris properties from the progenitor satellite'...

  4. Molecules as magnetic probes of starspots

    CERN Document Server

    Afram, Nadine

    2015-01-01

    Stellar dynamo processes can be explored by measuring the magnetic field. This is usually obtained using the atomic and molecular Zeeman effect in spectral lines. While the atomic Zeeman effect can only access warmer regions, the use of molecular lines is of advantage for studying cool objects. The molecules MgH, TiO, CaH, and FeH are suited to probe stellar magnetic fields, each one for a different range of spectral types, by considering the signal that is obtained from modeling various spectral types. We have analyzed the usefulness of different molecules (MgH, TiO, CaH, and FeH) as diagnostic tools for studying stellar magnetism on active G-K-M dwarfs. We investigate the temperature range in which the selected molecules can serve as indicators for magnetic fields on highly active cool stars and present synthetic Stokes profiles for the modeled spectral type. We modeled a star with a spot size of 10% of the stellar disk and a spot comprising either only longitudinal or only transverse magnetic fields and es...

  5. Probing the Casimir force with optical tweezers

    Science.gov (United States)

    Ether, D. S., Jr.; Pires, L. B.; Umrath, S.; Martinez, D.; Ayala, Y.; Pontes, B.; Araújo, G. R. de S.; Frases, S.; Ingold, G.-L.; Rosa, F. S. S.; Viana, N. B.; Nussenzveig, H. M.; Neto, P. A. Maia

    2015-11-01

    We propose to use optical tweezers to probe the Casimir interaction between microspheres inside a liquid medium for geometric aspect ratios far beyond the validity of the widely employed proximity force approximation. This setup has the potential for revealing unprecedented features associated to the non-trivial role of the spherical curvatures. For a proof of concept, we measure femtonewton double-layer forces between polystyrene microspheres at distances above 400 nm by employing very soft optical tweezers, with stiffness of the order of fractions of a fN/nm. As a future application, we propose to tune the Casimir interaction between a metallic and a polystyrene microsphere in saline solution from attraction to repulsion by varying the salt concentration. With those materials, the screened Casimir interaction may have a larger magnitude than the unscreened one. This line of investigation has the potential for bringing together different fields including classical and quantum optics, statistical physics and colloid science, while paving the way for novel quantitative applications of optical tweezers in cell and molecular biology.

  6. Probing the dark energy methods and strategies

    CERN Document Server

    Huterer, D; Huterer, Dragan; Turner, Michael S.

    2001-01-01

    The presence of dark energy in the Universe is inferred directly from the accelerated expansion of the Universe, and indirectly, from measurements of cosmic microwave background (CMB) anisotropy. Dark energy contributes about 2/3 of the critical density, is very smoothly distributed, and has large negative pressure. Its nature is very much unknown. Most of its discernible consequences follow from its effect on evolution of the expansion rate of the Universe, which in turn affects the growth of density perturbations and the age of the Universe, and can be probed by the classical kinematic cosmological tests. Absent a compelling theoretical model (or even a class of models), we describe the dark energy by an effective equation-of-state w=p_X/\\rho_X which is allowed to vary with time. We describe and compare different approaches for determining w(t), including magnitude-redshift (Hubble) diagram, number counts of galaxies and clusters, and CMB anisotropy, focusing particular attention on the use of a sample of s...

  7. Bioorthogonal probes for imaging sterols in cells.

    Science.gov (United States)

    Jao, Cindy Y; Nedelcu, Daniel; Lopez, Lyle V; Samarakoon, Thilani N; Welti, Ruth; Salic, Adrian

    2015-03-01

    Cholesterol is a fundamental lipid component of eukaryotic membranes and a precursor of potent signaling molecules, such as oxysterols and steroid hormones. Cholesterol and oxysterols are also essential for Hedgehog signaling, a pathway critical in embryogenesis and cancer. Despite their importance, the use of imaging sterols in cells is currently very limited. We introduce a robust and versatile method for sterol microscopy based on C19 alkyne cholesterol and oxysterol analogues. These sterol analogues are fully functional; they rescue growth of cholesterol auxotrophic cells and faithfully recapitulate the multiple roles that sterols play in Hedgehog signal transduction. Alkyne sterol analogues incorporate efficiently into cellular membranes and can be imaged with high resolution after copper(I)-catalyzed azide-alkyne cycloaddition reaction with fluorescent azides. We demonstrate the use of alkyne sterol probes for visualizing the subcellular distribution of cholesterol and for two-color imaging of sterols and choline phospholipids. Our imaging strategy should be broadly applicable to studying the role of sterols in normal physiology and disease.

  8. Efficient oligonucleotide probe selection for pan-genomic tiling arrays

    Directory of Open Access Journals (Sweden)

    Zhang Wei

    2009-09-01

    Full Text Available Abstract Background Array comparative genomic hybridization is a fast and cost-effective method for detecting, genotyping, and comparing the genomic sequence of unknown bacterial isolates. This method, as with all microarray applications, requires adequate coverage of probes targeting the regions of interest. An unbiased tiling of probes across the entire length of the genome is the most flexible design approach. However, such a whole-genome tiling requires that the genome sequence is known in advance. For the accurate analysis of uncharacterized bacteria, an array must query a fully representative set of sequences from the species' pan-genome. Prior microarrays have included only a single strain per array or the conserved sequences of gene families. These arrays omit potentially important genes and sequence variants from the pan-genome. Results This paper presents a new probe selection algorithm (PanArray that can tile multiple whole genomes using a minimal number of probes. Unlike arrays built on clustered gene families, PanArray uses an unbiased, probe-centric approach that does not rely on annotations, gene clustering, or multi-alignments. Instead, probes are evenly tiled across all sequences of the pan-genome at a consistent level of coverage. To minimize the required number of probes, probes conserved across multiple strains in the pan-genome are selected first, and additional probes are used only where necessary to span polymorphic regions of the genome. The viability of the algorithm is demonstrated by array designs for seven different bacterial pan-genomes and, in particular, the design of a 385,000 probe array that fully tiles the genomes of 20 different Listeria monocytogenes strains with overlapping probes at greater than twofold coverage. Conclusion PanArray is an oligonucleotide probe selection algorithm for tiling multiple genome sequences using a minimal number of probes. It is capable of fully tiling all genomes of a species on

  9. HERA: an atmospheric probe to unveil the depths of Saturn

    Science.gov (United States)

    Mousis, Olivier; Atkinson, David H.; Amato, Michael; Aslam, Shahid; Atreya, Sushil K.; Blanc, Michel; Bolton, Scott J.; Brugger, Bastien; Calcutt, Simon; Cavalié, Thibault; Charnoz, Sébastien; Coustenis, Athena; DELEUIL, Magali; Ferri, Francesca; Fletcher, Leigh N.; Guillot, Tristan; Hartogh, Paul; Holland, Andrew; Hueso, Ricardo; Keller, Christoph; Kessler, Ernst; Lebreton, Jean-Pierre; leese, Mark; Lellouch, Emmanuel; Levacher, Patrick; Marty, Bernard; Morse, Andrew; Nixon, Conor; Reh, Kim R.; Renard, Jean-Baptiste; Sanchez-Lavega, Agustin; Schmider, François-Xavier; Sheridan, Simon; Simon, Amy A.; Snik, Frans; Spilker, Thomas R.; Stam, Daphne M.; Venkatapathy, Ethiraj; Vernazza, Pierre; Waite, J. Hunter; Wurz, Peter

    2016-10-01

    The Hera Saturn entry probe mission is proposed as an M-class mission led by ESA with a significant collaboration with NASA. It consists of a Saturn atmospheric probe and a Carrier-Relay spacecraft. Hera will perform in situ measurements of the chemical and isotopic compositions as well as the dynamics of Saturn's atmosphere, with the goal of improving our understanding of the origin, formation, and evolution of Saturn, the giant planets and their satellite systems, with extrapolation to extrasolar planets.The primary science objectives will be addressed by an atmospheric entry probe that would descend under parachute and carry out in situ measurements beginning in the stratosphere to help characterize the location and properties of the tropopause, and continue into the troposphere to pressures of at least 10 bars. All of the science objectives, except for the abundance of oxygen, which may be only addressed indirectly via observations of species whose abundances are tied to the abundance of water, can be achieved by reaching 10 bars. As in previous highly successful collaborative efforts between ESA and NASA, the proposed mission has a baseline concept based on a NASA-provided carrier/data relay spacecraft that would deliver the ESA-provided atmospheric probe to the desired atmospheric entry point at Saturn. ESA's proposed contribution should fit well into the M5 Cosmic Vision ESA call cost envelope.A nominal mission configuration would consist of a probe that detaches from the carrier one to several months prior to probe entry. Subsequent to probe release, the carrier trajectory would be deflected to optimize the over-flight phasing of the probe descent location for both probe data relay as well as performing carrier approach and flyby science, and would allow multiple retransmissions of the probe data for redundancy. The Saturn atmospheric entry probe would in many respects resemble the Jupiter Galileo probe. It is anticipated that the probe architecture for

  10. EDITORIAL: Scanning probe microscopy: a visionary development Scanning probe microscopy: a visionary development

    Science.gov (United States)

    Demming, Anna

    2013-07-01

    The development of scanning probe microscopy repositioned modern physics. When Rohrer and Binnig first used electronic tunnelling effects to image atoms and quantum states they did more than pin down theoretical hypotheses to real-world observables; the scanning tunnelling microscope fed imaginations, prompting researchers to consider new directions and possibilities [1]. As Rohrer once commented, 'We could show that you can easily manipulate or position something small in space with an accuracy of 10 pm.... When you can do that, you simply have ideas of what you can do' [2]. The development heralded a cavalry of scanning probe techniques—such as atomic force microscopy (AFM) [3-5], scanning near-field optical microscopy (SNOM) [6-8] and Kelvin probe force microscopy (KPFM) [9, 10]—that still continue to bring nanomaterials and nanoscale phenomena into fresh focus. Not long after the development of scanning tunnelling microscopy, Binnig, Quate and Gerber collaborating in California in the US published work on a new type of microscope also capable of atomic level resolution [3]. The original concept behind scanning tunnelling microscopy uses electrical conductance, which places substantial limitations on the systems that it can image. Binnig, Quate and Gerber developed the AFM to 'feel' the topology of surfaces like the needle of an old fashioned vinyl player. In this way insulators could be imaged as well. The development of a force modulation mode AFM extended the tool's reach to soft materials making images of biological samples accessible with the technique [4]. There have now been a number of demonstrations of image capture at rates that allow dynamics at the nanoscale to be tracked in real time, opening further possibilities in applications of the AFM as described in a recent review by Toshio Ando at Kanazawa University [5]. Researchers also found a way to retrieve optical information at 'super-resolution' [6, 7]. Optical microscopy provides spectral

  11. Transient temperature probe measurements in a Mach 4 nitrogen jet

    Energy Technology Data Exchange (ETDEWEB)

    Buttsworth, D.R. [Faculty of Engineering and Surveying, University of Southern Queensland, 4350, Toowoomba, Queensland (Australia); Jones, T.V. [Department of Engineering Science, University of Oxford, OX1 3PJ, Oxford (United Kingdom)

    2004-07-01

    Stagnation temperature measurements have been obtained in a Mach 4 free jet of nitrogen using a technique based on transient thin film heat flux probe measurements. The uncertainty in the stagnation temperature measurements depends on the probe location within the jet but is typically around {+-}5 K at the centre of the jet. The thin film heat flux probe technique also provides a measurement of the heat transfer coefficient of the thin film probes with an uncertainty of around {+-}4% at the centre of the jet. Pitot pressure measurements were also obtained within the jet. Analysis of the heat transfer coefficient results yields the Mach number and velocity profiles which are compared with results from the pitot probe measurements. Jet velocities identified using the thin film probe and the pitot probe techniques produce results with uncertainties of less than {+-}2% at the centre of the jet. Measurements of RMS stagnation temperature fluctuations indicate values of around 3 K at the centre of the jet to more than 10 K in the shear layer. (orig.)

  12. [Development of Zn(2+) selective fluorescent probes for biological applications].

    Science.gov (United States)

    Hagimori, Masayori

    2013-01-01

    Zn(2+) is an essential element for life and is known to play important roles in biological processes including gene expression, apoptosis, enzyme regulation, immune system and neurotransmission. To investigate physiological roles of free or chelatable Zn(2+) in living cells, Zn(2+)-selective fluorescent probes are valuable tools. A variety of fluorescent probes based on quinoline, BF2 chelated dipyrromethene, fluorescein, etc. has been developed recently. In principle, such tools can provide useful information about zinc biology. However, most of the fluorescent probes presented so far possess a fluorescent core and a separate part for binding to Zn(2+) within the molecule, so that the molecular weight is usually large and the molecules are hydrophobic. As a result, the applications of such molecules in biological systems often face difficulties. Therefore, we need to develop a new class of fluorescent probes for Zn(2+) with improved molecular characteristics. If the initial core structure is small enough, the fluorescent probes may still be molecular weight below 500 with desirable physico-chemical properties, even after the modifications. In this review, we described novel low-molecular-weight fluorescent probes for Zn(2+) based on pyridine-pyridone. Small modification of pyridine-pyridone core structure brought about a marked improvement such as aqueous solubility, affinity toward Zn(2+), and fluorescence ON/OFF switching. Fluorescence images of Zn(2+) in cells showed that the pyridine-pyridone probe can be used in biological applications.

  13. A virtual optical probe based on evanescent wave interference

    Institute of Scientific and Technical Information of China (English)

    孙利群; 王佳; 洪涛; 田芊

    2002-01-01

    A virtual probe is a novel immaterial tip based on the near-field evanescent wave interference and small aperture diffraction, which can be used in near-field high-density optical data storage, nano-lithography, near-field optical imaging and spectral detection, near-field optical manipulation of nano-scale specimen, etc. In this paper, the formation mechanism of the virtual probe is analysed, the evanescent wave interference discussed theoretically, andthe sidelobe suppression by small aperture is simulated by the three-dimensional finite-difference time-domain method The simulation results of the optical distribution of the near-field virtual probe reveal that the transmission efficiencyof the virtual probe is 102-104 times higher than that of the nano-aperture metal-coated fibre probe widely used in near-field optical systems. The full width at half maximum of the peak, in other words, the size of virtual probe, is constant whatever the distance in a certain range so that the critical nano-separation control in the near-field system can be relaxed. We give an example of the application of the virtual probe in ultrahigh-density optical data storage.

  14. Huygens probe entry dynamic model and accelerometer data analysis

    Science.gov (United States)

    Colombatti, Giacomo; Aboudan, Alessio; Ferri, Francesca; Angrilli, Francesco

    2008-04-01

    During the first phase of Huygens arrival into Titan's atmosphere the probe is subjected to gravitational and aerodynamic forces in aerodynamic hypersonic regime. Atmospheric drag exerts a strong deceleration on the capsule measured by Huygens atmospheric structure instrument (HASI) servo accelerometer. A 6 DOF (Degree of Freedom) model of the Huygens probe entry dynamics has been developed and used for data analysis. The accelerometer data are analysed and the model allows the retrieval of dynamics information of Huygens probe from 1545 km altitude down to end of the entry phase. Probe's initial conditions (velocity and position) were refined to match the measured deceleration profile resulting in a different altitude at interface epoch with respect to those of the Cassini Navigation Team. Velocity and position of probe at interface epoch are compatible with those used by Descent Trajectory Working Group (DTWG). Measurements acquired before atmosphere detection are used to estimate probe's angular rate, bound attitude and characterise the angle of attack profile which results to be lower than 4∘ during the whole entry. Probe's spin calculated (6.98 RPM) is slightly different with respect to DTWG of 7.28 RPM but considering a 2% error in the Inertia matrix these results are inside the 1-σ error band.

  15. Magnetic field concentrator for probing optical magnetic metamaterials.

    Science.gov (United States)

    Antosiewicz, Tomasz J; Wróbel, Piotr; Szoplik, Tomasz

    2010-12-01

    Development of all dielectric and plasmonic metamaterials with a tunable optical frequency magnetic response creates a need for new inspection techniques. We propose a method of measuring magnetic responses of such metamaterials within a wide range of optical frequencies with a single probe. A tapered fiber probe with a radially corrugated metal coating concentrates azimuthally polarized light in the near-field into a subwavelength spot the longitudinal magnetic field component which is much stronger than the perpendicular electric one. The active probe may be used in a future scanning near-field magnetic microscope for studies of magnetic responses of subwavelength elementary cells of metamaterials.

  16. Scheme for efficient fiber-based CARS probe

    Science.gov (United States)

    Balu, Mihaela; Liu, Gangjun; Chen, Zhongping; Tromberg, Bruce J.; Potma, Eric O.

    2010-02-01

    We demonstrate a fiber-based probe for maximum collection of the Coherent anti-Stokes Raman Scattering (CARS) signal in biological tissues. We discuss the design challenges including capturing the back-scattered forward generated CARS signal in the sample and the effects of fiber nonlinearities on the propagating pulses. Three different biological tissues were imaged in vitro in order to assess the performance of our fiberdelivered probe for CARS imaging, a tool which we consider an important advance towards label-free, in vivo probing of superficial tissues.

  17. Fundamental size limitations of micro four-point probes

    DEFF Research Database (Denmark)

    Ansbæk, Thor; Petersen, Dirch Hjorth; Hansen, Ole;

    2009-01-01

    The continued down-scaling of integrated circuits and magnetic tunnel junctions (MTJ) for hard disc read heads presents a challenge to current metrology technology. The four-point probes (4PP), currently used for sheet resistance characterization in these applications, therefore must be down......-scaled as well in order to correctly characterize the extremely thin films used. This presents a four-point probe design and fabrication challenge. We analyze the fundamental limitation on down-scaling of a generic micro four-point probe (M4PP) in a comprehensive study, where mechanical, thermal, and electrical...

  18. Detecting and Tracking Nonfluorescent Nanoparticles Probes in Live Cells

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Gufeng; Fang, Ning

    2012-01-17

    Precisely imaging and tracking dynamic biological processes in live cells are crucial for both fundamental research in life sciences and biomedical applications. Nonfluorescent nanoparticles are emerging as important optical probes in live-cell imaging because of their excellent photostability, large optical cross sections, and low cytotoxicity. Here, we provide a review of recent development in optical imaging of nonfluorescent nanoparticle probes and their applications in dynamic tracking and biosensing in live cells. A brief discussion on cytotoxicity of nanoparticle probes is also provided.

  19. Fast Diagnosis of Transient Plasma by Langmuir Probe

    Institute of Scientific and Technical Information of China (English)

    TANG En-ling; ZHANG Qing-ming; OUYANG Ji-ting

    2007-01-01

    A method for the fast measurement of electron temperature and density with temporal resolution in transient plasma has been implemented by Langmuir probe. The diagnostic system consists of a single Langmuir probe driven by a high frequency sinusoidal voltage. The current and voltage spectrum on the probe were detected synchronously by an oscilloscope with sampling rate being at least 5 times higher than the frequency of sweep voltage. The system has been used to diagnose the transient plasma generated by hypervelocity-impact of LY12 aluminum projectile into LY12 aluminum target.

  20. Probe Selection for DNA Microarrays using OligoWiz

    DEFF Research Database (Denmark)

    Wernersson, Rasmus; Juncker, Agnieszka; Nielsen, Henrik Bjørn

    2007-01-01

    Nucleotide abundance measurements using DNA microarray technology are possible only if appropriate probes complementary to the target nucleotides can be identified. Here we present a protocol for selecting DNA probes for microarrays using the OligoWiz application. OligoWiz is a client......-server application that offers a detailed graphical interface and real-time user interaction on the client side, and massive computer power and a large collection of species databases (400, summer 2007) on the server side. Probes are selected according to five weighted scores: cross-hybridization, deltaT(m), folding...

  1. Manipulating collective quantum states of ultracold atoms by probing

    DEFF Research Database (Denmark)

    Wade, Andrew Christopher James

    2015-01-01

    nature of the measurement interaction and backaction is yet to be realised. This dissertation is concerned with ultracold atoms and their control via fully quantum mechanical probes. Nonclassical, squeezed and entangled states of matter and single photon sources are important for fundamental studies...... and quantum technologies. By probing, the production of squeezed and entangled states of collective variables in a Bose-Einstein condensate is investigated. Thereafter, an atomic probe using the strong interactions between highly excited atomic states, manipulates the light-matter dynamics of an ultracold gas...

  2. Contributed Review: Quartz force sensing probes for micro-applications

    Science.gov (United States)

    Abrahamians, Jean-Ochin; Pham Van, Laurent; Régnier, Stéphane

    2016-07-01

    As self-sensing and self-exciting probes, quartz sensors present many advantages over silicon cantilevers for microscopy, micro-robotics, and other micro-applications. Their development and use is further bolstered by the fact that they can be manufactured from common quartz components. This paper therefore reviews applications of the increasingly popular quartz tuning fork probes as force sensors in the literature and examines the options for higher-frequency quartz probes using the other available types of flexional, thickness-shear or length-extensional resonators.

  3. A note on measurement of sound pressure with intensity probes

    DEFF Research Database (Denmark)

    Juhl, Peter; Jacobsen, Finn

    2004-01-01

    The effect of scattering and diffraction on measurement of sound pressure with "two-microphone" sound intensity probes is examined using an axisymmetric boundary element model of the probe. Whereas it has been shown a few years ago that the sound intensity estimated with a two-microphone probe...... is reliable up to 10 kHz when using 0.5 in. microphones in the usual face-to-face arrangement separated by a 12 mm spacer, the sound pressure measured with the same instrument will typically be underestimated at high frequencies. It is shown in this paper that the estimate of the sound pressure can...

  4. Design of magnetic probes for MHD measurements in ASDEX tokamak

    International Nuclear Information System (INIS)

    The design of magnetic probes (Mirnov coils) is described in this report. These probes are used in ASDEX to investigate MHD modes and measure the plasma displacement together with magnetic flux loops. Concerning the high temperature rise during a plasma shot proper material for the coil form of the magnetic probes and the suitable wire and cable in the high vacuum chamber in conjunction with special geometrical construction have been selected. The electrical circuit updated to operate in a high noise environment is shown and first MHD mode signals demonstrate the effeciency of the system. (orig.)

  5. Holographic probes of collapsing black holes

    International Nuclear Information System (INIS)

    We continue the programme of exploring the means of holographically decoding the geometry of spacetime inside a black hole using the gauge/gravity correspondence. To this end, we study the behaviour of certain extremal surfaces (focusing on those relevant for equal-time correlators and entanglement entropy in the dual CFT) in a dynamically evolving asymptotically AdS spacetime, specifically examining how deep such probes reach. To highlight the novel effects of putting the system far out of equilibrium and at finite volume, we consider spherically symmetric Vaidya-AdS, describing black hole formation by gravitational collapse of a null shell, which provides a convenient toy model of a quantum quench in the field theory. Extremal surfaces anchored on the boundary exhibit rather rich behaviour, whose features depend on dimension of both the spacetime and the surface, as well as on the anchoring region. The main common feature is that they reach inside the horizon even in the post-collapse part of the geometry. In 3-dimensional spacetime, we find that for sub-AdS-sized black holes, the entire spacetime is accessible by the restricted class of geodesics whereas in larger black holes a small region near the imploding shell cannot be reached by any boundary-anchored geodesic. In higher dimensions, the deepest reach is attained by geodesics which (despite being asymmetric) connect equal time and antipodal boundary points soon after the collapse; these can attain spacetime regions of arbitrarily high curvature and simultaneously have smallest length. Higher-dimensional surfaces can penetrate the horizon while anchored on the boundary at arbitrarily late times, but are bounded away from the singularity. We also study the details of length or area growth during thermalization. While the area of extremal surfaces increases monotonically, geodesic length is neither monotonic nor continuous

  6. Scanning probe microscopy of functionalised metal surfaces

    International Nuclear Information System (INIS)

    Scanning Tunnelling Microscopy (STM) has been used to investigate various properties of functionalised gold surfaces. The primary aim behind such studies has been to develop a 'molecular level' understanding of the mechanism of different surface processes at the solid-air and more importantly, at the solid-liquid interfaces. A small organic molecule, 4-amino-2-mercaptopyrimidine and a small biological molecule (a hexapeptide), KCTCCA, have been studied in their adsorbed state on gold (111) to understand their role in electrochemical promotion of cytochrome c and cytochrome b562 respectively. The process of protein adsorption at the gold (111)-air/liquid interfaces has been probed with Pseudomonas aeruginosa azurin, Pseudomonas putida putidaredoxin and Pseudomonas putida cytochrome P450 to develop an understanding of the protein adsorption process in general. Isolated protein molecules as well as high coverage of molecules are observed. The process of adsorption can be monitored in real time and the results indicate the justification of applicability of Langmuir adsorption theory. Rubredoxin, a small iron-sulphur protein, has been studied for reasons associated with its structural characteristics. The metal site is solvent exposed in this protein. This aids in enhanced tunnelling near the metal site resulting in an enhancement in the contrast, leading to an achievement of a sub-molecular resolution in a metalloprotein by STM. 'Single molecule' imaging by STM has been extended from the level of discerning the shape of a protein/enzyme molecule adsorbed in the solid-liquid interface to that of monitoring a complex formation reaction between a protein molecule and an enzyme molecule. Complexes between putidaredoxin and cytochrome P450 molecules with various intermolecular distances and angular arrangements have been imaged at the gold-water interface. This indicates the possibility of deriving electrochemical information from a specific complex at a specific time

  7. High Count Rate Electron Probe Microanalysis

    Science.gov (United States)

    Geller, Joseph D.; Herrington, Charles

    2002-01-01

    Reducing the measurement uncertainty of quantitative analyses made using electron probe microanalyzers (EPMA) requires a careful study of the individual uncertainties from each definable step of the measurement. Those steps include measuring the incident electron beam current and voltage, knowing the angle between the electron beam and the sample (takeoff angle), collecting the emitted x rays from the sample, comparing the emitted x-ray flux to known standards (to determine the k-ratio) and transformation of the k-ratio to concentration using algorithms which includes, as a minimum, the atomic number, absorption, and fluorescence corrections. This paper discusses the collection and counting of the emitted x rays, which are diffracted into the gas flow or sealed proportional x-ray detectors. The representation of the uncertainty in the number of collected x rays collected reduces as the number of counts increase. The uncertainty of the collected signal is fully described by Poisson statistics. Increasing the number of x rays collected involves either counting longer or at a higher counting rate. Counting longer means the analysis time increases and may become excessive to get to the desired uncertainty. Instrument drift also becomes an issue. Counting at higher rates has its limitations, which are a function of the detector physics and the detecting electronics. Since the beginning of EPMA analysis, analog electronics have been used to amplify and discriminate the x-ray induced ionizations within the proportional counter. This paper will discuss the use of digital electronics for this purpose. These electronics are similar to that used for energy dispersive analysis of x rays with either Si(Li) or Ge(Li) detectors except that the shaping time constants are much smaller. PMID:27446749

  8. Electrochemical techniques for characterization of stem-loop probe and linear probe-based DNA sensors.

    Science.gov (United States)

    Lai, Rebecca Y; Walker, Bryce; Stormberg, Kent; Zaitouna, Anita J; Yang, Weiwei

    2013-12-15

    Here we present a summary of the sensor performance of the stem-loop probe (SLP) and linear probe (LP) electrochemical DNA sensors when interrogated using alternating current voltammetry (ACV), cyclic voltammetry (CV), and differential pulse voltammetry (DPV). Specifically, we identified one critical parameter for each voltammetric technique that can be adjusted for optimal sensor performance. Overall, the SLP sensor displayed good sensor performance (i.e., 60+% signal attenuation in the presence of the target) over a wider range of experimental conditions when compared to the LP sensor. When used with ACV, the optimal frequency range was found to be between 5 and 5000 Hz, larger than the 5-100 Hz range observed with the LP sensor. A similar trend was observed for the two sensors in CV; the LP sensor was operational only at scan rates between 30 and 100 V/s, whereas the SLP sensor performed well at scan rates between 1 and 1000 V/s. Unlike ACV and CV, DPV has demonstrated to be a more versatile sensor interrogation technique for this class of sensors. Despite the minor differences in total signal attenuation upon hybridization to the target DNA, both SLP and LP sensors performed optimally under most pulse widths used in this study. More importantly, when used with longer pulse widths, both sensors showed "signal-on" behavior, which is generally more desirable for sensor applications.

  9. Electrical probe characteristic recovery by measuring only one time-dependent parameter

    Science.gov (United States)

    Costin, C.; Popa, G.; Anita, V.

    2016-03-01

    Two straightforward methods for recovering the current-voltage characteristic of an electrical probe are proposed. Basically, they consist of replacing the usual power supply from the probe circuit with a capacitor which can be charged or discharged by the probe current drained from the plasma. The experiment requires the registration of only one time-dependent electrical parameter, either the probe current or the probe voltage. The corresponding time-dependence of the second parameter, the probe voltage, or the probe current, respectively, can be calculated using an integral or a differential relation and the current-voltage characteristic of the probe can be obtained.

  10. Magnetic probe array with high sensitivity for fluctuating field.

    Science.gov (United States)

    Kanamaru, Yuki; Gota, Hiroshi; Fujimoto, Kayoko; Ikeyama, Taeko; Asai, Tomohiko; Takahashi, Tsutomu; Nogi, Yasuyuki

    2007-03-01

    A magnetic probe array is constructed to measure precisely the spatial structure of a small fluctuating field included in a strong confinement field that varies with time. To exclude the effect of the confinement field, the magnetic probes consisting of figure-eight-wound coils are prepared. The spatial structure of the fluctuating field is obtained from a Fourier analysis of the probe signal. It is found that the probe array is more sensitive to the fluctuating field with a high mode number than that with a low mode number. An experimental demonstration of the present method is attempted using a field-reversed configuration plasma, where the fluctuating field with 0.1% of the confinement field is successfully detected.

  11. Gold nanoclusters with enhanced tunable fluorescence as bioimaging probes.

    Science.gov (United States)

    Palmal, Sharbari; Jana, Nikhil R

    2014-01-01

    Development of unique bioimaging probes offering essential information's about bio environments are an important step forward in biomedical science. Nanotechnology offers variety of novel imaging nanoprobes having high-photo stability as compared to conventional molecular probes which often experience rapid photo bleaching problem. Although great advances have been made on the development of semiconductor nanocrystals-based fluorescent imaging probes, potential toxicity issue by heavy metal component limits their in vivo therapeutic and clinical application. Recent works show that fluorescent gold clusters (FGCs) can be a promising nontoxic alternative of semiconductor nanocrystals. FGCs derived imaging nanoprobes offer stable and tunable visible emission, small hydrodynamic size, high biocompatibility and have been exploited in variety in vitro and in vivo imaging applications. In this review, we will focus on the synthetic advances and bioimaging application potentials of FGCs. In particular, we will emphasize on functional FGCs that are bright and stable enough to be useful as bioimaging probes.

  12. Effect of filament supports on emissive probe measurements

    Energy Technology Data Exchange (ETDEWEB)

    Wang, X.; Howes, C. T. [Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, Colorado 80309 (United States); NASA Lunar Science Institute: Colorado Center for Lunar Dust and Atmospheric Studies, Boulder, Colorado 80309 (United States); Horanyi, M. [Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, Colorado 80309 (United States); NASA Lunar Science Institute: Colorado Center for Lunar Dust and Atmospheric Studies, Boulder, Colorado 80309 (United States); Department of Physics, University of Colorado, Boulder, Colorado 80309 (United States); Robertson, S. [NASA Lunar Science Institute: Colorado Center for Lunar Dust and Atmospheric Studies, Boulder, Colorado 80309 (United States); Department of Physics, University of Colorado, Boulder, Colorado 80309 (United States)

    2013-01-15

    We have constructed an emissive probe with a thin tungsten filament spot-welded across two nickel wires insulated with ceramic paint. We show that the ceramic supports covering the nickel wires have a large effect on the potential measurements in low-density plasmas. It is found that the potential measured by the emissive probe is more negative than the potential derived from a Langmuir probe current-voltage (I-V) characteristic curve when the plasma density is so low that the emitting filament remains immersed in the sheaths of the ceramic supports. The length of the filament L needs to be larger than about 2 Debye lengths (L > 2{lambda}{sub De}) in order to avoid the influence of the ceramic supports and to achieve reliable plasma potential measurements using emissive probes.

  13. Advances in Defocused-Beam Electron-Probe Microanalysis

    Science.gov (United States)

    Carpenter, P. K.; Zeigler, R. A.; Jolliff, B. L.

    2010-03-01

    Advances in defocused-beam electron-probe microanalysis are presented, with an Excel VBA algorithm which uses a polynomial alpha factor correction algorithm coupled with a catanorm procedure to correct DBA data.

  14. Intracellular probes for imaging oxygen concentration: how good are they?

    Science.gov (United States)

    Dmitriev, Ruslan I.; Papkovsky, Dmitri B.

    2015-09-01

    In the last decade a number of cell-permeable phosphorescence based probes for imaging of (intra)cellular oxygen (icO2) have been described. These small molecule, supramolecular and nanoparticle structures, although allowing analysis of hypoxia, local gradients and fluctuations in O2, responses to stimulation and drug treatment at sub-cellular level with high spatial and temporal resolution, differ significantly in their operational performance and applicability to different cell and tissue models. Here we discuss and compare these probes with respect to their staining efficiency, brightness, photostability, toxicity, cell specificity, compatibility with different cell and tissue models, and analytical performance. Merits and limitations of particular probes are highlighted and strategies for development of new high-performance O2 imaging probes defined. Key application areas in hypoxia research, stem cells, cancer biology and tissue physiology are also discussed.

  15. Thermal Analysis of Small Re-Entry Probe

    Science.gov (United States)

    Agrawal, Parul; Prabhu, Dinesh K.; Chen, Y. K.

    2012-01-01

    The Small Probe Reentry Investigation for TPS Engineering (SPRITE) concept was developed at NASA Ames Research Center to facilitate arc-jet testing of a fully instrumented prototype probe at flight scale. Besides demonstrating the feasibility of testing a flight-scale model and the capability of an on-board data acquisition system, another objective for this project was to investigate the capability of simulation tools to predict thermal environments of the probe/test article and its interior. This paper focuses on finite-element thermal analyses of the SPRITE probe during the arcjet tests. Several iterations were performed during the early design phase to provide critical design parameters and guidelines for testing. The thermal effects of ablation and pyrolysis were incorporated into the final higher-fidelity modeling approach by coupling the finite-element analyses with a two-dimensional thermal protection materials response code. Model predictions show good agreement with thermocouple data obtained during the arcjet test.

  16. Nanofabrication of magnetic scanned-probe microscope sensors

    CERN Document Server

    Chong, B K

    2001-01-01

    experiments were carried out under ambient conditions. The experiments required no extra preparation to be done to the specimen before imaging and measurements were carried out under ambient conditions. These probes offer the prospect of direct magnetic field measurement, non- invasiveness, very close proximity, possible local manipulation, better control over the tip- specimen interaction distance and topographic imaging. It is hoped that these magnetic microscope probes will be of great interest and general utility for academic and industrial magneticians. This thesis presents the development of novel magnetic sensor combined with Atomic Force Microscope probe (AFM) using conventional semiconductor processing techniques and Electron Beam Lithography (EBL). The fabrication of these magnetic sensors was performed on a common micromachined silicon substrate using a generic batch fabrication technique. Sub-micron Hall bar for Scanning Hall probe Microscopy (SHPM) and electromagnetic force coil magnet for Scanni...

  17. Morphological Computation of Haptic Perception of a Controllable Stiffness Probe.

    Science.gov (United States)

    Sornkarn, Nantachai; Dasgupta, Prokar; Nanayakkara, Thrishantha

    2016-01-01

    When people are asked to palpate a novel soft object to discern its physical properties such as texture, elasticity, and even non-homogeneity, they not only regulate probing behaviors, but also the co-contraction level of antagonistic muscles to control the mechanical impedance of fingers. It is suspected that such behavior tries to enhance haptic perception by regulating the function of mechanoreceptors at different depths of the fingertips and proprioceptive sensors such as tendon and spindle sensors located in muscles. In this paper, we designed and fabricated a novel two-degree of freedom variable stiffness indentation probe to investigate whether the regulation of internal stiffness, indentation, and probe sweeping velocity (PSV) variables affect the accuracy of the depth estimation of stiff inclusions in an artificial silicon phantom using information gain metrics. Our experimental results provide new insights into not only the biological phenomena of haptic perception but also new opportunities to design and control soft robotic probes. PMID:27257814

  18. Design and Synthesis of Matrix Metalloprotease Photoaffinity Trimodular Probes

    Institute of Scientific and Technical Information of China (English)

    QIU,Wenwei; XU,Jie; LI,Xin; ZHONG,Li; LI,Jingya; LI,Jia; NAN,Fajun

    2009-01-01

    To explore the molecular mechanism of the matrix metalloproteinases (MMPs) in tumor processes,two photoaffinity trimodular probes were designed and synthesized based on the structure activity relationship and the following photoaffinity labelling experiments afforded positive results.

  19. Morphological Computation of Haptic Perception of a Controllable Stiffness Probe.

    Directory of Open Access Journals (Sweden)

    Nantachai Sornkarn

    Full Text Available When people are asked to palpate a novel soft object to discern its physical properties such as texture, elasticity, and even non-homogeneity, they not only regulate probing behaviors, but also the co-contraction level of antagonistic muscles to control the mechanical impedance of fingers. It is suspected that such behavior tries to enhance haptic perception by regulating the function of mechanoreceptors at different depths of the fingertips and proprioceptive sensors such as tendon and spindle sensors located in muscles. In this paper, we designed and fabricated a novel two-degree of freedom variable stiffness indentation probe to investigate whether the regulation of internal stiffness, indentation, and probe sweeping velocity (PSV variables affect the accuracy of the depth estimation of stiff inclusions in an artificial silicon phantom using information gain metrics. Our experimental results provide new insights into not only the biological phenomena of haptic perception but also new opportunities to design and control soft robotic probes.

  20. Dr. Harry Whelan With the Light Emitting Diode Probe

    Science.gov (United States)

    1999-01-01

    The red light from the Light Emitting Diode (LED) probe shines through the fingers of Dr. Harry Whelan, a pediatric neurologist at the Children's Hospital of Wisconsin in Milwaukee. Dr. Whelan uses the long waves of light from the LED surgical probe to activate special drugs that kill brain tumors. Laser light previously has been used for this type of surgery, but the LED light illuminates through all nearby tissues, reaching parts of tumors that shorter wavelengths of laser light carnot. The new probe is safer because the longer wavelengths of light are cooler than the shorter wavelengths of laser light, making the LED less likely to injure normal brain tissue near the tumor. Also, it can be used for hours at a time while still remaining cool to the touch. The probe was developed for photodynamic cancer therapy under a NASA Small Business Innovative Research Program grant. The program is part of NASA's Technology Transfer Department at the Marshall Space Flight Center.

  1. Theoretical study of a flat eddy current probe

    International Nuclear Information System (INIS)

    A mathematical model for the computation of the impedance of an eddy current probe has been determined in the case of flat product testing. Various applications are discussed with particular emphasis on ferromagnetic materials

  2. Small molecule probes for plant cell wall polysaccharide imaging

    Directory of Open Access Journals (Sweden)

    Ian eWallace

    2012-05-01

    Full Text Available Plant cell walls are composed of interlinked polymer networks consisting of cellulose, hemicelluloses, pectins, proteins, and lignin. The ordered deposition of these components is a dynamic process that critically affects the development and differentiation of plant cells. However, our understanding of cell wall synthesis and remodeling, as well as the diverse cell wall architectures that result from these processes, has been limited by a lack of suitable chemical probes that are compatible with live-cell imaging. In this review, we summarize the currently available molecular toolbox of probes for cell wall polysaccharide imaging in plants, with particular emphasis on recent advances in small molecule-based fluorescent probes. We also discuss the potential for further development of small molecule probes for the analysis of cell wall architecture and dynamics.

  3. Advanced Technology Cloud Particle Probe for UAS Project

    Data.gov (United States)

    National Aeronautics and Space Administration — In Phase II SPEC will design, fabricate and flight test a state-of-the-art combined cloud particle probe called the Hawkeye. Hawkeye is the culmination of two...

  4. Probing into Magnetic Field and Initial Period of Neutron Star

    Institute of Scientific and Technical Information of China (English)

    BAI Hua; PENG Qiu-He

    2004-01-01

    Using the hybrid model and the neutrino jet rocket model, we calculate the magnetic fields and the initial periods of 72 pulsars. We probe into the possible connection among magnetic field, initial period, and initial quantum number.

  5. Depletion interaction measured by colloidal probe atomic force microscopy

    NARCIS (Netherlands)

    Wijting, W.K.; Knoben, W.; Besseling, N.A.M.; Leermakers, F.A.M.; Cohen Stuart, M.A.

    2004-01-01

    We investigated the depletion interaction between stearylated silica surfaces in cyclohexane in the presence of dissolved polydimethylsiloxane by means of colloidal probe atomic force microscopy. We found that the range of the depletion interaction decreases with increasing concentration. Furthermor

  6. Dynamic probing of educational quality: the SEIN system

    OpenAIRE

    Westera, Wim; Wouters, Pieter; Ebrecht, Diny; Vos, Marcel; Boon, Jo

    2009-01-01

    Westera, W., Wouters, P., Ebrecht, D., Vos, M., & Boon, J. (2007). Dynamic probing of educational quality: the SEIN system. In A. Landeta (Ed.), Good Practice E-Learning Book (Chapter 10, pp. 165-176). Madrid, Spain: ANCED.

  7. Ratiometric Fluorescent pH Probes Based on Glycopolymers.

    Science.gov (United States)

    Li, Zhiyun; Zhang, Pengshan; Lu, Wei; Peng, Lun; Zhao, Yun; Chen, Gaojian

    2016-09-01

    Effectively detecting pH changes plays a critical role in exploring cellular functions and determining physiological and pathological processes. A novel ratiometric pH probe based on a glycopolymer, armored with properties of serum-stability, tumor-targeting, and pH monitoring, is designed. Random copolymers of 2-(methacrylamido) glucopyranose and fluorescein O-methacrylate are first synthesized by reversible addition fragmentation chain transfer polymerization. Acryloxyethyl thiocarbamoyl rhodamine B is then attached to the polymer chain to prepare ratiometric fluorescent pH probes via a thiol-ene reaction. The synthesized polymeric probes are characterized by NMR, gel permeation chromatography, UV-vis spectroscopy, and transmission electron microscopy, and the fluorescence responses are examined in phosphate buffer at different pHs. The cytotoxicity and confocal imaging experiments of the probes are detected using HeLa cells, demonstrating a low toxicity and superior biocompatibility for detecting pH changes in bioapplications. PMID:27439338

  8. Dual-probe spectroscopic fingerprints of defects in graphene

    DEFF Research Database (Denmark)

    Settnes, Mikkel; Power, Stephen; Petersen, Dirch Hjorth;

    2014-01-01

    (e.g., an extended graphene sheet). Applying this method, we study the transport anisotropies in pristine graphene sheets, and analyze the spectroscopic fingerprints arising from quantum interference around single-site defects, such as vacancies and adatoms. Furthermore, we demonstrate that the dual......Recent advances in experimental techniques emphasize the usefulness of multiple scanning probe techniques when analyzing nanoscale samples. Here, we analyze theoretically dual-probe setups with probe separations in the nanometer range, i.e., in a regime where quantum coherence effects can......-probe setup is a useful tool for characterizing the electronic transport properties of extended defects or designed nanostructures. In particular, we show that nanoscale perforations, or antidots, in a graphene sheet display Fano-type resonances with a strong dependence on the edge geometry of the perforation....

  9. Probing Local Environments by Time-Resolved Stimulated Emission Spectroscopy

    Directory of Open Access Journals (Sweden)

    Ana Rei

    2012-01-01

    Full Text Available Time-resolved stimulated emission spectroscopy was employed to probe the local environment of DASPMI (4-(4-(dimethylaminostyryl-N-methyl-pyridinium iodide in binary solvents of different viscosity and in a sol-gel matrix. DASPMI is one of the molecules of choice to probe local environments, and the dependence of its fluorescence emission decay on viscosity has been previously used for this purpose in biological samples, solid matrices as well as in solution. The results presented in this paper show that time-resolved stimulated emission of DASPMI is a suitable means to probe the viscosity of local environments. Having the advantage of a higher time resolution, stimulated emission can provide information that is complementary to that obtained from fluorescence decay measurements, making it feasible to probe systems with lower viscosity.

  10. Deposition of molecular probes in heavy ion tracks

    CERN Document Server

    Esser, M

    1999-01-01

    By using polarized fluorescence techniques the physical properties of heavy ion tracks such as the dielectric number, molecular alignment and track radius can be traced by molecular fluorescence probes. Foils of poly(ethylene terephthalate) (PET) were used as a matrix for the ion tracks wherein fluorescence probes such as aminostyryl-derivatives can be incorporated using a suitable solvent, e.g. N,N'-dimethylformamide (DMF) as transport medium. The high sensitivity of fluorescence methods allowed the comparison of the probe properties in ion tracks with the virgin material. From the fluorescence Stokes shift the dielectric constants could be calculated, describing the dielectric surroundings of the molecular probes. The lower dielectric constant in the tracks gives clear evidence that there is no higher accommodation of the highly polar solvent DMF in the tracks compared with the virgin material. Otherwise the dielectric constant in the tracks should be higher than in the virgin material. The orientation of t...

  11. Probing black holes in non-perturbative gauge theory

    CERN Document Server

    Iizuka, N; Lifschytz, G; Lowe, D A; Iizuka, Norihiro; Kabat, Daniel; Lifschytz, Gilad; Lowe, David A.

    2002-01-01

    We use a 0-brane to probe a ten-dimensional near-extremal black hole with N units of 0-brane charge. We work directly in the dual strongly-coupled quantum mechanics, using mean-field methods to describe the black hole background non-perturbatively. We obtain the distribution of W boson masses, and find a clear separation between light and heavy degrees of freedom. To localize the probe we introduce a resolving time and integrate out the heavy modes. After a non-trivial change of coordinates, the effective potential for the probe agrees with supergravity expectations. We compute the entropy of the probe, and find that the stretched horizon of the black hole arises dynamically in the quantum mechanics, as thermal restoration of unbroken U(N+1) gauge symmetry. Our analysis of the quantum mechanics predicts a correct relation between the horizon radius and entropy of a black hole.

  12. Machine set to probe secrets of the universe

    CERN Multimedia

    Lovell, Jeremy

    2006-01-01

    "Deep underground on the Franco-Swiss border someonw will throw a switch next year to start one of the most ambitious experiments in history, probing the secrets of the universe and possibly finding new dimensions."

  13. Polarization of fluorescence: a probe of molecular autoionization

    Energy Technology Data Exchange (ETDEWEB)

    Leroi, G. E. [Michigan State Univ., East Lansing, MI (United States); Dehmer, Joseph L. [Argonne National Laboratory (ANL), Argonne, IL (United States); Parr, Albert C. [National Bureau of Standards, Washington, DC (United States); Poliakoff, E. D. [Boston Univ., MA (United States)

    1983-01-01

    The polarization of fluorescence from excited-state molecular photoions provides a direct probe of the photoionization dynamics and the symmetry signatures of autoionizing resonances. Measurements on CO₂ and CS₂ are presented as examples.

  14. Development of a radio frequency excited local impedance probe

    International Nuclear Information System (INIS)

    Local void fraction measurements were made with a Karlsruhe type impedance probe. The probe was operated at radiofrequency to minimize sensitivity to liquid phase resistivity. Two types of signal thresholding were used: level and derivative. A dual beam X-ray system was used as a calibration standard for the radio frequency excited impedance probe. Calibration was performed in vertical air/water flows. Derivative thresholding was found to be preferable to level thresholding, however, in both schemes hydrodynamic and surface tension effects were observed below a liquid superficial velocity of 0.5 m/s. Table salt (NaCl) was added to the water to verify the probe's response to changing water resistivity. Derivative thresholding appeared to work quite well but level thresholding was found to be inadequate due to the change in capacitance. (orig.)

  15. Design and spacecraft-integration of RTGs for solar probe

    Science.gov (United States)

    Schock, A.; Noravian, H.; Or, T.; Sankarankandath, V.

    1990-01-01

    The design, analysis, and spacecraft integration of radioisotope thermoelectric generators (RTG) to power the Solar Probe under study at NASA JPL is described. The mission of the Solar Probe is to explore the solar corona by performing in situ measurements at up to four solar radii to the sun. Design constraints for the RTG are discussed. The chief challenge in the design and system integration of the Solar Probe's RTG is a heat rejection problem. Two RTG orientations, horizontal and oblique, are analyzed for effectiveness and results are summarized in chart form. A number of cooling strategies are also investigated, including heat-pipe and reflector-cooled options. A methodology and general computer code are presented for analyzing the performance of arbitrarily obstructed RTGs with both axial and circumferential temperature, voltage, and current variation. This methodology is applied to the specific example of the Solar Probe RTG obstructed by a semicylindrical reflector of 15-inch radius.

  16. Mobile probes: A scaffold for local learning with online resources?

    DEFF Research Database (Denmark)

    Ørngreen, Rikke; Jørgensen, Anna; Noesgaard, Signe Schack

    2016-01-01

    A project investigating the effectiveness of a collection of online resources for teachers' professional development used mobile probes as a data collection method. Teachers received questions and tasks on their mobile in a dialogic manner while in their everyday context as opposed to in an inter......A project investigating the effectiveness of a collection of online resources for teachers' professional development used mobile probes as a data collection method. Teachers received questions and tasks on their mobile in a dialogic manner while in their everyday context as opposed...... level. This paper is an initial investigation of how the mobile probes process proved to engage teachers in their efforts to improve teaching. It also highlights some of the barriers emerging when applying mobile probes as a scaffold for learning....

  17. Giant machine set to probe secrets of the universe

    CERN Multimedia

    2006-01-01

    "Deep underground on the Franco-Swiss border someone will throw a switch next year to start one of the most ambitious experiments in history, probing the secrets of the universe and possibly finding new dimensions." (1 page)

  18. Giant machine set to probe secrets of the universe

    CERN Multimedia

    2006-01-01

    "Deep underground on the Franco-Swiss border someone will throw a switch next year to start one of the most ambitious experiments in history, probing the secrets of the universe and possibly finding new dimensions." (2/3 page)

  19. Response of an electrostatic probe for a right cylindrical spacer

    DEFF Research Database (Denmark)

    Rerup, T; Crichton, George C; McAllister, Iain Wilson

    1994-01-01

    During the last decade many experimental studies of surface charge phenomena have been undertaken employing right cylindrical spacers. Measurement of the surface charge was performed using small electrostatic field probes to scan across the dielectric surface. Charges are electrostatically induced...

  20. Probing Nanoscale Electronic and Magnetic Interaction with Scanning Tunneling Spectroscopy

    DEFF Research Database (Denmark)

    Bork, Jakob

    This thesis is concerned with fundamental research into electronic and magnetic interaction on the nanoscale. From small metallic and magnetic islands and layers to single atoms. The research revolves around magnetic interaction probed through the spectroscopic capabilities of the scanning...

  1. The multipole resonance probe: characterization of a prototype

    Energy Technology Data Exchange (ETDEWEB)

    Lapke, Martin; Oberrath, Jens; Brinkmann, Ralf Peter; Mussenbrock, Thomas [Lehrstuhl fuer Theoretische Elektrotechnik, Ruhr-Universitaet Bochum, D-44780 Bochum (Germany); Schulz, Christian; Rolfes, Ilona [Lehrstuhl fuer Hochfrequenzsysteme, Ruhr-Universitaet Bochum, D-44780 Bochum (Germany); Storch, Robert; Musch, Thomas [Lehrstuhl fuer Elektronische Schaltungstechnik, Ruhr-Universitaet Bochum, D-44780 Bochum (Germany); Styrnoll, Tim; Awakowicz, Peter [Lehrstuhl fuer Allgemeine Elektrotechnik und Plasmatechnik, Ruhr Universitaet Bochum, D-44780 Bochum (Germany); Zietz, Christian [Institut fuer Hochfrequenztechnik und Funksysteme, Leibniz Universitaet Hannover, D-30167 Hannover (Germany)

    2011-08-15

    The multipole resonance probe (MRP) was recently proposed as an economical and industry compatible plasma diagnostic device (Lapke et al 2008 Appl. Phys. Lett. 93 051502). This communication reports the experimental characterization of a first MRP prototype in an inductively coupled argon/nitrogen plasma at 10 Pa. The behavior of the device follows the predictions of both an analytical model and a numerical simulation. The obtained electron densities are in excellent agreement with the results of Langmuir probe measurements. (brief communication)

  2. Combining Portable Raman Probes with Nanotubes for Theranostic Applications

    OpenAIRE

    Ashwinkumar A. Bhirde, Gang Liu, Albert Jin, Ramiro Iglesias-Bartolome, Alioscka A. Sousa, Richard D. Leapman, J. Silvio Gutkind, Seulki Lee, Xiaoyuan Chen

    2011-01-01

    Recently portable Raman probes have emerged along with a variety of applications, including carbon nanotube (CNT) characterization. Aqueous dispersed CNTs have shown promise for biomedical applications such as drug/gene delivery vectors, photo-thermal therapy, and photoacoustic imaging. In this study we report the simultaneous detection and irradiation of carbon nanotubes in 2D monolayers of cancer cells and in 3D spheroids using a portable Raman probe. A portable handheld Raman instrument wa...

  3. Handheld, giant magnetoresistive-sensor-based eddy current probes

    Science.gov (United States)

    Brady, S. K.; Palmer, D. D.

    2012-05-01

    The minimum crack length detectable with conventional eddy current probes increases dramatically as the thickness of metal through which the inspection is performed increases. The skin depth phenomenon is unavoidable, and demands low frequency inspection, hindering sensitivity. However, one time derivative introduced by Faraday's Law can be avoided by using giant magnetoresistive sensors to detect eddy currents instead of conventional coils, improving sensitivity. The theory will be explained, along with some probe designs and the observed benefits in sensitivity.

  4. Fiber Optic Broadband Ultrasonic Probe for Virtual Biopsy: Technological Solutions

    OpenAIRE

    Biagi, E.; Cerbai, S.; Masotti, L.; L. Belsito; A. RONCAGLIA; Masetti, G.; N. Speciale

    2010-01-01

    An ultrasonic probe was developed by using, in conjunction, optoacoustic and acousto-optic devices based on fiber optic technology. The intrinsic high frequency and wide bandwidth associated both to the opto-acoustic source and to the acousto-optic receiving element could open a way towards a “virtual biopsy” of biological tissue. A Micro-Opto-Mechanical-System (MOMS) approach is proposed to realize the broadband ultrasonic probe on micromachined silicon frames suited to be mounted on the tip...

  5. Amyloid-β positron emission tomography imaging probes

    DEFF Research Database (Denmark)

    Kepe, Vladimir; Moghbel, Mateen C; Långström, Bengt;

    2013-01-01

    , a number of factors appear to preclude these probes from clinical utilization. As the available "amyloid specific" positron emission tomography imaging probes have failed to demonstrate diagnostic value and have shown limited utility for monitoring therapeutic interventions in humans, a debate...... on their significance has emerged. The aim of this review is to identify and discuss critically the scientific issues contributing to the extensive inconsistencies reported in the literature on their purported in vivo amyloid specificity and potential utilization in patients....

  6. Generation of probe signal for feedback cancellation systems

    OpenAIRE

    Odelius, Johan

    2004-01-01

    A common problem of hearing aids is whistling caused by feedback from the loudspeaker back to the microphone. A method of reducing the negative effects, caused by the feedback, is called feedback cancellation. A variant of feedback cancellation uses a probe signal, which is applied to the speaker of the hearing aid and is used to continuously estimate the feedback. Oticon A/S has suggested a master's thesis with the purpose of designing and evaluating an algorithm generating a probe signal fo...

  7. Scanning probe microscopy from the perspective of the sensor

    OpenAIRE

    Stirling, Julian

    2014-01-01

    The class of instruments considered in this thesis, scanning probe microscopes (SPM), raster scan a sensory probe over a surface to form both high resolution images and quantitative interaction measurements. Understanding and extracting information from SPM data has been considered extensively in the three decades since the first SPM. Major developments tend to be greeted with their own theory and data analysis techniques. The more gradual evolution of equipment has not, however, attracted th...

  8. Square waveguide antenna using L-shaped probe

    Science.gov (United States)

    Fukusako, Takeshi; Okuhata, Kazutoshi; Mita, Nagahisa

    2004-04-01

    A circularly polarized waveguide antenna using a simple feed structure is proposed and investigated. The feed probe forms L character put on a sidewall of the waveguide so that circular polarization can be generated by the traveling wave on the L-probe. This paper describes the proposed scheme and the experimental CP characteristics of waveguide antenna. Finally, simulated results by finite-difference time-domain (FDTD) method are presented.

  9. DNA hybridization probe for clinical diagnosis of Entamoeba histolytica.

    OpenAIRE

    Samuelson, J.; Acuna-Soto, R; Reed, S; Biagi, F; Wirth, D.

    1989-01-01

    As an alternative to microscopic identification of Entamoeba histolytica parasites isolated from stool, a sensitive and species-specific DNA hybridization probe was made for rapid diagnosis of E. histolytica parasites in clinical samples directly applied to nylon membranes. The DNA hybridization probe was made by screening a genomic library of a virulent HM-1:IMSS strain of E. histolytica to detect recombinant plasmids containing highly repeated parasite DNA sequences. Four plasmid clones tha...

  10. All-fiber Raman Probe using Higher Order Modes

    DEFF Research Database (Denmark)

    Larsen, Stine Højer Møller; Rishøj, Lars Søgaard; Rottwitt, Karsten

    2013-01-01

    We demonstrate the first all-fiber Raman probe utilizing higher order modes for the excitation. The spectrum of cyclohexane is measured using both the fundamental mode as well as in-fiber-generated Bessel-like modes.......We demonstrate the first all-fiber Raman probe utilizing higher order modes for the excitation. The spectrum of cyclohexane is measured using both the fundamental mode as well as in-fiber-generated Bessel-like modes....

  11. Scanned probe microscopy for thin film superconductor development

    Energy Technology Data Exchange (ETDEWEB)

    Moreland, J. [National Institute of Standards and Technology, Boulder, CO (United States)

    1996-12-31

    Scanned probe microscopy is a general term encompassing the science of imaging based on piezoelectric driven probes for measuring local changes in nanoscale properties of materials and devices. Techniques like scanning tunneling microscopy, atomic force microscopy, and scanning potentiometry are becoming common tools in the production and development labs in the semiconductor industry. The author presents several examples of applications specific to the development of high temperature superconducting thin films and thin-film devices.

  12. Probing Local Environments by Time-Resolved Stimulated Emission Spectroscopy

    OpenAIRE

    Ana Rei; Graham Hungerford; Michael Belsley; Ferreira, M. Isabel C.; Peter Schellenberg

    2012-01-01

    Time-resolved stimulated emission spectroscopy was employed to probe the local environment of DASPMI (4-(4-(dimethylamino)styryl)-N-methyl-pyridinium iodide) in binary solvents of different viscosity and in a sol-gel matrix. DASPMI is one of the molecules of choice to probe local environments, and the dependence of its fluorescence emission decay on viscosity has been previously used for this purpose in biological samples, solid matrices as well as in solution. The results presented in this p...

  13. Bioluminescent Probe for Detecting Mercury(II) in Living Mice.

    Science.gov (United States)

    Jiang, Tianyu; Ke, Bowen; Chen, Hui; Wang, Weishan; Du, Lupei; Yang, Keqian; Li, Minyong

    2016-08-01

    A novel bioluminescence probe for mercury(II) was obtained on the basis of the distinct deprotection reaction of dithioacetal to decanal, so as to display suitable sensitivity and selectivity toward mercury(II) over other ions with bacterial bioluminescence signal. These experimental results indicated such a probe was a novel promising method for mercury(II) bioluminescence imaging in environmental and life sciences ex vivo and in vivo. PMID:27412583

  14. Probing Quantum Capacitance in a 3D Topological Insulator

    Science.gov (United States)

    Kozlov, D. A.; Bauer, D.; Ziegler, J.; Fischer, R.; Savchenko, M. L.; Kvon, Z. D.; Mikhailov, N. N.; Dvoretsky, S. A.; Weiss, D.

    2016-04-01

    We measure the quantum capacitance and probe thus directly the electronic density of states of the high mobility, Dirac type two-dimensional electron system, which forms on the surface of strained HgTe. Here we show that observed magnetocapacitance oscillations probe—in contrast to magnetotransport—primarily the top surface. Capacitance measurements constitute thus a powerful tool to probe only one topological surface and to reconstruct its Landau level spectrum for different positions of the Fermi energy.

  15. Capacitance of Graphene Bilayer as a Which-Layer Probe

    OpenAIRE

    Young, Andrea F.; Levitov, Leonid S.

    2011-01-01

    The unique capabilities of capacitance measurements in bilayer graphene enable probing of layer-specific properties that are normally out of reach in transport measurements. Furthermore, capacitance measurements in the top-gate and penetration field geometries are sensitive to different physical quantities: the penetration field capacitance probes the two layers equally, whereas the top gate capacitance preferentially samples the near layer, resulting in the "near-layer capacitance enhancemen...

  16. Molecular probe for identification of Trichomonas vaginalis DNA.

    OpenAIRE

    Rubino, S; Muresu, R; Rappelli, P; Fiori, P. L.; Rizzu, P; Erre, G; Cappuccinelli, P

    1991-01-01

    Trichomoniasis is one of the most widespread sexually transmitted diseases in the world. Diagnosis can be achieved by several methods, such as direct microscopic observation of vaginal discharge, cell culture, and immunological techniques. A 2.3-kb Trichomonas vaginalis DNA fragment present in strains from diverse geographic areas was cloned and used as a probe to detect T. vaginalis DNA in vaginal discharge by a dot blot hybridization technique. This probe was specific for T. vaginalis DNA. ...

  17. Utilizing Gold Nanoparticle Probes to Visually Detect DNA Methylation.

    Science.gov (United States)

    Chen, Kui; Zhang, Mingyi; Chang, Ya-Nan; Xia, Lin; Gu, Weihong; Qin, Yanxia; Li, Juan; Cui, Suxia; Xing, Gengmei

    2016-12-01

    The surface plasmon resonance (SPR) effect endows gold nanoparticles (GNPs) with the ability to visualize biomolecules. In the present study, we designed and constructed a GNP probe to allow the semi-quantitative analysis of methylated tumor suppressor genes in cultured cells. To construct the probe, the GNP surfaces were coated with single-stranded DNA (ssDNA) by forming Au-S bonds. The ssDNA contains a thiolated 5'-end, a regulatory domain of 12 adenine nucleotides, and a functional domain with absolute pairing with methylated p16 sequence (Met-p16). The probe, paired with Met-p16, clearly changed the color of aggregating GNPs probe in 5 mol/L NaCl solution. Utilizing the probe, p16 gene methylation in HCT116 cells was semi-quantified. Further, the methylation of E-cadherin, p15, and p16 gene in Caco2, HepG2, and HCT116 cell lines were detected by the corresponding probes, constructed with three domains. This simple and cost-effective method was useful for the diagnosis of DNA methylation-related diseases. PMID:27325520

  18. An Elegant Biosensor Molecular Beacon Probe: Challenges and Recent Solutions

    Directory of Open Access Journals (Sweden)

    Dmitry M. Kolpashchikov

    2012-01-01

    Full Text Available Molecular beacon (MB probes are fluorophore- and quencher-labeled short synthetic DNAs folded in a stem-loop shape. Since the first report by Tyagi and Kramer, it has become a widely accepted tool for nucleic acid analysis and triggered a cascade of related developments in the field of molecular sensing. The unprecedented success of MB probes stems from their ability to detect specific DNA or RNA sequences immediately after hybridization with no need to wash out the unbound probe (instantaneous format. Importantly, the hairpin structure of the probe is responsible for both the low fluorescent background and improved selectivity. Furthermore, the signal is generated in a reversible manner; thus, if the analyte is removed, the signal is reduced to the background. This paper highlights the advantages of MB probes and discusses the approaches that address the challenges in MB probe design. Variations of MB-based assays tackle the problem of stem invasion, improve SNP genotyping and signal-to-noise ratio, as well as address the challenges of detecting folded RNA and DNA.

  19. Ultrasonic Periodontal Probing Based on the Dynamic Wavelet Fingerprint

    Directory of Open Access Journals (Sweden)

    Rose S Timothy

    2005-01-01

    Full Text Available Manual pocket depth probing has been widely used as a retrospective diagnosis method in periodontics. However, numerous studies have questioned its ability to accurately measure the anatomic pocket depth. In this paper, an ultrasonic periodontal probing method is described, which involves using a hollow water-filled probe to focus a narrow beam of ultrasound energy into and out of the periodontal pocket, followed by automatic processing of pulse-echo signals to obtain the periodontal pocket depth. The signal processing algorithm consists of three steps: peak detection/characterization, peak classification, and peak identification. A dynamic wavelet fingerprint (DWFP technique is first applied to detect suspected scatterers in the A-scan signal and generate a two-dimensional black and white pattern to characterize the local transient signal corresponding to each scatterer. These DWFP patterns are then classified by a two-dimensional FFT procedure and mapped to an inclination index curve. The location of the pocket bottom was identified as the third broad peak in the inclination index curve. The algorithm is tested on full-mouth probing data from two sequential visits of 14 patients. Its performance is evaluated by comparing ultrasonic probing results with that of full-mouth manual probing at the same sites, which is taken as the "gold standard."

  20. A new OTDR based on probe frequency multiplexing

    Science.gov (United States)

    Lu, Lidong; Liang, Yun; Li, Binglin; Guo, Jinghong; Zhang, Xuping

    2013-12-01

    Two signal multiplexing methods are proposed and experimentally demonstrated in optical time domain reflectometry (OTDR) for fault location of optical fiber transmission line to obtain high measurement efficiency. Probe signal multiplexing is individually obtained by phase modulation for generation of multi-frequency and time sequential frequency probe pulses. The backscattered Rayleigh light of the multiplexing probe signals is transferred to corresponding heterodyne intermediate frequency (IF) through heterodyning with the single frequency local oscillator (LO). Then the IFs are simultaneously acquired by use of a data acquisition card (DAQ) with sampling rate of 100Msps, and the obtained data are processed by digital band pass filtering (BPF), digital down conversion (DDC) and digital low pass filtering (BPF) procedure. For each probe frequency of the detected signals, the extraction of the time domain reflecting signal power is performed by parallel computing method. For a comprehensive performance comparison with conventional coherent OTDR on the probe frequency multiplexing methods, the potential for enhancement of dynamic range, spatial resolution and measurement time are analyzed and discussed. Experimental results show that by use of the probe frequency multiplexing method, the measurement efficiency of coherent OTDR can be enhanced by nearly 40 times.

  1. The LC resonance probe for determining local plasma density

    Energy Technology Data Exchange (ETDEWEB)

    Boris, D R; Fernsler, R F; Walton, S G, E-mail: david.boris.ctr@nrl.navy.mi [Naval Research Laboratory, Charge Particle Physics Branch-Code 6752, Plasma Physics Division, 4555 Overlook Ave. SW, Washington, DC 20375 (United States)

    2011-04-15

    We present a novel plasma diagnostic for measuring local plasma density in reactive-gas plasmas, and depositing plasmas. The diagnostic uses a network analyzer to measure the LC resonance (LCR) frequency of a parallel plate capacitor with inductive leads. The location of the LCR ({omega}{sub R}) in frequency space is then used as a measure of the plasma dielectric constant bold varepsilon{sub p} between the plates. By properly constructing the LCR probe, {omega}{sub R} can be tuned such that {omega}{sub R} >> {omega}{sub ce}, where {omega}{sub ce} is the electron-cyclotron frequency. Thus, the probe can be used in plasmas with varying degrees of magnetization while avoiding complications introduced to bold varepsilon{sub p} when {omega} is comparable to {omega}{sub ce}. Density measurements from the LCR probe are compared with Langmuir probe measurements in an electron-beam generated plasma in which density varied from 10{sup 9} to 10{sup 11} cm{sup -3}. An axial magnetic field, typically used to confine the electron beam, was varied between 0 to 300 G. The LCR probe showed good agreement with a Langmuir probe across the entire range of magnetic fields.

  2. Characterization of axial probes used in eddy current testing

    International Nuclear Information System (INIS)

    Customized reference tubes reduced sensitivity discrepancies able to be observed from one probe to the other, due to the gain setting adjustment required for a pre-definite level in amplitude response of the artificial notch. The use of a reference circuit in place of a reference part, makes characterization of the probe matched to its generator more accurate: - the material dependence is cancelled during the compensation process, - the reference signal can be adjusted more accurately in amplitude and phase response, - the manufacturing cost is reduced compared to the one necessary for machining the reference part, - the amplitude and phase response of the reference circuit can be simply modelled by using the transformer relations, such as one can appreciate the variations of the probe definition parameters and its connexion to the generator, and makes them optimal for use. The method proposed by ALSTOM for the characterization of the condenser and exchanger tubing probes, takes in account the amplitude and phase response of a reference circuit versus frequency, such it can be done by using SURECA tubing provided by ASCOT: it allows to control that the frequency values of the probe required for use are inside the useful bandwidth defined by the - 6 dB attenuation from the maximum amplitude response of the reference circuit versus frequency. Examples coming from measurements done among more than 200 probes, for which faults have been observed and replacements made by the manufacturer, are displayed and commented. (authors)

  3. Design of fiber optic probes for laser light scattering

    Science.gov (United States)

    Dhadwal, Harbans S.; Chu, Benjamin

    1989-01-01

    A quantitative analysis is presented of the role of optical fibers in laser light scattering. Design of a general fiber optic/microlens probe by means of ray tracing is described. Several different geometries employing an optical fiber of the type used in lightwave communications and a graded index microlens are considered. Experimental results using a nonimaging fiber optic detector probe show that due to geometrical limitations of single mode fibers, a probe using a multimode optical fiber has better performance, for both static and dynamic measurements of the scattered light intensity, compared with a probe using a single mode fiber. Fiber optic detector probes are shown to be more efficient at data collection when compared with conventional approaches to measurements of the scattered laser light. Integration of fiber optic detector probes into a fiber optic spectrometer offers considerable miniaturization of conventional light scattering spectrometers, which can be made arbitrarily small. In addition static and dynamic measurements of scattered light can be made within the scattering cell and consequently very close to the scattering center.

  4. Utilizing Gold Nanoparticle Probes to Visually Detect DNA Methylation

    Science.gov (United States)

    Chen, Kui; Zhang, Mingyi; Chang, Ya-Nan; Xia, Lin; Gu, Weihong; Qin, Yanxia; Li, Juan; Cui, Suxia; Xing, Gengmei

    2016-06-01

    The surface plasmon resonance (SPR) effect endows gold nanoparticles (GNPs) with the ability to visualize biomolecules. In the present study, we designed and constructed a GNP probe to allow the semi-quantitative analysis of methylated tumor suppressor genes in cultured cells. To construct the probe, the GNP surfaces were coated with single-stranded DNA (ssDNA) by forming Au-S bonds. The ssDNA contains a thiolated 5'-end, a regulatory domain of 12 adenine nucleotides, and a functional domain with absolute pairing with methylated p16 sequence (Met- p16). The probe, paired with Met- p16, clearly changed the color of aggregating GNPs probe in 5 mol/L NaCl solution. Utilizing the probe, p16 gene methylation in HCT116 cells was semi-quantified. Further, the methylation of E-cadherin, p15, and p16 gene in Caco2, HepG2, and HCT116 cell lines were detected by the corresponding probes, constructed with three domains. This simple and cost-effective method was useful for the diagnosis of DNA methylation-related diseases.

  5. Ultrasonic Periodontal Probing Based on the Dynamic Wavelet Fingerprint

    Science.gov (United States)

    Hou, Jidong; Rose, S. Timothy; Hinders, Mark K.

    2005-12-01

    Manual pocket depth probing has been widely used as a retrospective diagnosis method in periodontics. However, numerous studies have questioned its ability to accurately measure the anatomic pocket depth. In this paper, an ultrasonic periodontal probing method is described, which involves using a hollow water-filled probe to focus a narrow beam of ultrasound energy into and out of the periodontal pocket, followed by automatic processing of pulse-echo signals to obtain the periodontal pocket depth. The signal processing algorithm consists of three steps: peak detection/characterization, peak classification, and peak identification. A dynamic wavelet fingerprint (DWFP) technique is first applied to detect suspected scatterers in the A-scan signal and generate a two-dimensional black and white pattern to characterize the local transient signal corresponding to each scatterer. These DWFP patterns are then classified by a two-dimensional FFT procedure and mapped to an inclination index curve. The location of the pocket bottom was identified as the third broad peak in the inclination index curve. The algorithm is tested on full-mouth probing data from two sequential visits of 14 patients. Its performance is evaluated by comparing ultrasonic probing results with that of full-mouth manual probing at the same sites, which is taken as the "gold standard."

  6. PREFACE: Quantum dots as probes in biology

    Science.gov (United States)

    Cieplak, Marek

    2013-05-01

    photosynthetic systems. The next paper, by Olejnik et al, discussed metallic QDs which enhance photosynthetic function in light-harvesting biomolecular complexes. Such hybrid structures with gold QDs are shown to exhibit a strong increase in the fluorescence quantum yield. The next two papers, by Sikora et al and Kaminska et al deal with the ZnO nanoparticles passivated by MgO. In the first of these two papers, the authors describe the behavior of ZnO/MgO when introduced to human cancer cells. In the second, the authors describe the QDs with an extra outer layer of Fe2O3 which makes the nanoparticles superparamagnetic and also capable of generation of reactive oxygen species which could be applied to form localized centers of toxicity for cancer treatment. Finally, in the last paper by Yatsunenko et al, the authors discuss several semiconducting QDs like ZnO with various rare-earth dopands. They propose a microwave-driven hydrothermal technology to make them, characterize their luminescence and demonstrate their usefulness in the early recognition of cancer tissues. Quantum dots as probes in biology contents Quantum dots as probes in biologyMarek Cieplak Luminescent nanoparticles and their applications in the life sciencesVarun K A Sreenivasan, Andrei V Zvyagin and Ewa M Goldys Ferredoxin:NADP+ oxidoreductase in junction with CdSe/ZnS quantum dots: characteristics of an enzymatically active nanohybrid Krzysztof Szczepaniak, Remigiusz Worch and Joanna Grzyb Spectroscopic studies of plasmon coupling between photosynthetic complexes and metallic quantum dotsMaria Olejnik, Bartosz Krajnik, Dorota Kowalska, Guanhua Lin and Sebastian Mackowski Luminescence of colloidal ZnO nanoparticles synthesized in alcohols and biological application of ZnO passivated by MgOBożena Sikora, Krzysztof Fronc, Izabela Kamińska, Kamil Koper, Piotr Stępień and Danek Elbaum Novel ZnO/MgO/Fe2O3 composite optomagnetic nanoparticles I Kamińska, B Sikora, K Fronc, P Dziawa, K Sobczak, R Minikayev, W

  7. Femtosecond Pump-Push-Probe and Pump-Dump-Probe Spectroscopy of Conjugated Polymers: New Insight and Opportunities.

    Science.gov (United States)

    Kee, Tak W

    2014-09-18

    Conjugated polymers are an important class of soft materials that exhibit a wide range of applications. The excited states of conjugated polymers, often referred to as excitons, can either deactivate to yield the ground state or dissociate in the presence of an electron acceptor to form charge carriers. These interesting properties give rise to their luminescence and the photovoltaic effect. Femtosecond spectroscopy is a crucial tool for studying conjugated polymers. Recently, more elaborate experimental configurations utilizing three optical pulses, namely, pump-push-probe and pump-dump-probe, have been employed to investigate the properties of excitons and charge-transfer states of conjugated polymers. These studies have revealed new insight into femtosecond torsional relaxation and detrapping of bound charge pairs of conjugated polymers. This Perspective highlights (1) the recent achievements by several research groups in using pump-push-probe and pump-dump-probe spectroscopy to study conjugated polymers and (2) future opportunities and potential challenges of these techniques.

  8. Optical probing of sample heating in scanning near-field experiments with apertured probes

    International Nuclear Information System (INIS)

    We have used the inherent thermochromism of conjugated polymers to investigate substrate heating effects in scanning near-field experiments with metal-coated 'apertured' probes. Chemically etched and pulled fibers were used to provide near-field excitation of fully converted films of poly(p-phenylene vinylene), PPV, and of poly(4,4'-diphenylene diphenylvinylene). We detect no significant blueshift of the photoluminescence spectra generated with near-field excitation, in comparison to those collected with far-field excitation. We conclude that polymer heating in the region contributing to the luminescence is less than 40 K. We also demonstrate that thermolithography of the PPV precursor is not significant by comparing UV (325 nm) and red (670 nm) illumination

  9. Probing Dark Energy via Weak Gravitational Lensing with the SuperNova Acceleration Probe (SNAP)

    CERN Document Server

    Albert, J; Allam, S; Althouse, W E; Amanullah, R; Annis, J; Astier, Pierre; Aumeunier, M; Bailey, S; Baltay, C; Barrelet, E; Basa, S; Bebek, C; Bergström, L; Bernstein, G; Bester, M; Besuner, B; Bigelow, B; Blandford, R; Bohlin, R; Bonissent, A; Bower, C; Brown, M; Campbell, M; Carithers, W; Cole, D; Commins, Eugene D; Craig, W; Davis, T; Dawson, K; Day, C; De Harveng, M; De Jongh, F; Deustua, S; Diehl, H; Dobson, T; Dodelson, S; Ealet, A; Ellis, R; Emmet, W; Figer, D; Fouchez, D; Frerking, M; Frieman, J A; Fruchter, A; Gerdes, D; Gladney, L; Goldhaber, G; Goobar, A; Groom, D; Heetderks, H; Hoff, M; Holland, S; Huffer, M; Hui, L; Huterer, D; Jain, B; Jelinsky, P; Juramy, C; Karcher, A; Kent, S; Kahn, S; Kim, A; Kolbe, W; Krieger, B; Kushner, G; Kuznetsova, N; Lafever, R; Lamoureux, J; Lampton, M; Lefèvre, O; Lebrun, V; Levi, M; Limon, P; Lin, H; Linder, E; Loken, S; Lorenzon, W; Malina, R; Marian, L; Marriner, J P; Marshall, P; Massey, R; Mazure, A; McGinnis, B; McKay, T; McKee, S; Miquel, R; Mobasher, B; Morgan, N; Mortsell, E; Mostek, N; Mufson, S; Musser, J; Nakajima, R; Nugent, P; Olus, H; Pain, R; Palaio, N; De Pankow, M; Peoples, John; Perlmutter, S; Peterson, D; Prieto, E; Rabinowitz, D; Réfrégier, A; Rhodes, J; Roe, N; Rusin, D; Scarpine, V; Schubnell, M; Seiffert, M; Sholl, M; Shukla, H; Smadja, G; Smith, R M; Smoot, George F; Snyder, J; Spadafora, A; Stabenau, F; Stebbins, A; Stoughton, C; Szymkowiak, A; Tarle, G; Taylor, K; Tilquin, A; Tomasch, A; Tucker, D; Vincent, D; Von der Lippe, H; Walder, J P; Wang, G; Weinstein, A; Wester, W; White, M

    2005-01-01

    SNAP is a candidate for the Joint Dark Energy Mission (JDEM) that seeks to place constraints on the dark energy using two distinct methods. The first, Type Ia SN, is discussed in a companion white paper. The second method is weak gravitational lensing, which relies on the coherent distortions in the shapes of background galaxies by foreground mass structures. The excellent spatial resolution and photometric accuracy afforded by a 2-meter space-based observatory are crucial for achieving the high surface density of resolved galaxies, the tight control of systematic errors in the telescope's Point Spread Function (PSF), and the exquisite redshift accuracy and depth required by this project. These are achieved by the elimination of atmospheric distortion and much of the thermal and gravity loads on the telescope. The SN and WL methods for probing dark energy are highly complementary and the error contours from the two methods are largely orthogonal.

  10. Comparison of magnetic probe calibration at nano and millitesla magnitudes

    Science.gov (United States)

    Pahl, Ryan A.; Rovey, Joshua L.; Pommerenke, David J.

    2014-01-01

    Magnetic field probes are invaluable diagnostics for pulsed inductive plasma devices where field magnitudes on the order of tenths of tesla or larger are common. Typical methods of providing a broadband calibration of dot{{B}} probes involve either a Helmholtz coil driven by a function generator or a network analyzer. Both calibration methods typically produce field magnitudes of tens of microtesla or less, at least three and as many as six orders of magnitude lower than their intended use. This calibration factor is then assumed constant regardless of magnetic field magnitude and the effects of experimental setup are ignored. This work quantifies the variation in calibration factor observed when calibrating magnetic field probes in low field magnitudes. Calibration of two dot{{B}} probe designs as functions of frequency and field magnitude are presented. The first dot{{B}} probe design is the most commonly used design and is constructed from two hand-wound inductors in a differential configuration. The second probe uses surface mounted inductors in a differential configuration with balanced shielding to further reduce common mode noise. Calibration factors are determined experimentally using an 80.4 mm radius Helmholtz coil in two separate configurations over a frequency range of 100-1000 kHz. A conventional low magnitude calibration using a vector network analyzer produced a field magnitude of 158 nT and yielded calibration factors of 15 663 ± 1.7% and 4920 ± 0.6% {T}/{V {s}} at 457 kHz for the surface mounted and hand-wound probes, respectively. A relevant magnitude calibration using a pulsed-power setup with field magnitudes of 8.7-354 mT yielded calibration factors of 14 615 ± 0.3% and 4507 ± 0.4% {T}/{V {s}} at 457 kHz for the surface mounted inductor and hand-wound probe, respectively. Low-magnitude calibration resulted in a larger calibration factor, with an average difference of 9.7% for the surface mounted probe and 12.0% for the hand-wound probe. The

  11. Photon-assisted Beam Probes for Low Temperature Plasmas and Installation of Neutral Beam Probe in Helimak

    Science.gov (United States)

    Garcia de Gorordo, Alvaro; Hallock, Gary A.; Kandadai, Nirmala

    2008-11-01

    The Heavy Ion Beam Probe (HIBP) diagnostic has successfully measured the electric potential in a number of major plasma devices in the fusion community. In contrast to a Langmuir probe, the HIBP measures the exact electric potential rather than the floating potential. It is also has the advantage of being a very nonperturbing diagnostic. We propose a new photon-assisted beam probe technique that would extend the HIBP type of diagnostics into the low temperature plasma regime. We expect this method to probe plasmas colder than 10 eV. The novelty of the proposed diagnostic is a VUV laser that ionizes the probing particle. Excimer lasers produce the pulsed VUV radiation needed. The lasers on the market don't have a short enough wavelength too ionize any ion directly and so we calculate the population density of excited states in a NLTE plasma. These new photo-ionization techniques can take an instantaneous one-dimensional potential measurement of a plasma and are ideal for nonmagnitized plasmas where continuous time resolution is not required. Also the status of the Neutral Beam Probe installation on the Helimak experiment will be presented.

  12. The FIELDS experiment for Solar Probe Plus

    Science.gov (United States)

    Bale, S.; Spp/Fields Team

    2010-12-01

    Many of our basic ideas on the plasma physics of acceleration, energy flow, and dissipation, and structure of the solar wind have never been rigorously confronted by direct experimental measurements in the region where these processes are actually occurring. Although Alfven waves, shocks, and magnetic reconnection are often invoked as heating mechanisms, there have never been any direct measurements of Alfvenic waves nor the associated Poynting flux nor any measurements of ion or electron kinetic energy flux in the region from 10 R_s to 30 R_s where the final stages of wind acceleration are believed to occur. The radial profiles of both slow and fast solar wind acceleration are based on remote-sensing measurements and have been obtained for only a few selected events. Thus, the spatial radial and perpendicular scales of the acceleration process have been averaged by line-of-sight effects and the possibility of intense localized acceleration cannot be ruled out. The Solar Probe Plus (SPP) mission calls for the high quality fields and particles measurements required to solve the coronal heating and wind acceleration problem. The SPP 'FIELDS' experiment measures the electric and magnetic fields fundamental to the plasma physics of the structured and turbulent solar wind, flux ropes, collisionless shocks, and magnetic reconnection. FIELDS will make the first-ever measurements of the DC/Low-Frequency electric field inside of 1 AU allowing for in situ, high cadence measurements of the Poynting vector, the Elsasser variables, and E/B diagnostics of the wave spectrum to fce in the solar wind. SPP/FIELDS measures the radio wave (type III and II) signatures of microflares, energized electrons, and CME propagation. SPP/ FIELDS measures the plasma electron density to ~2% accuracy and the core electron temperature to ~5-10% accuracy more than 90% of the time at perihelion. FIELDS will also measure the in situ density fluctuation spectrum and structures at a very high cadence (

  13. Contact resonances of U-shaped atomic force microscope probes

    Energy Technology Data Exchange (ETDEWEB)

    Rezaei, E.; Turner, J. A., E-mail: jaturner@unl.edu [Mechanical and Materials Engineering, University of Nebraska-Lincoln, W342 Nebraska Hall, Lincoln, Nebraska 68588 (United States)

    2016-01-21

    Recent approaches used to characterize the elastic or viscoelastic properties of materials with nanoscale resolution have focused on the contact resonances of atomic force microscope (CR-AFM) probes. The experiments for these CR-AFM methods involve measurement of several contact resonances from which the resonant frequency and peak width are found. The contact resonance values are then compared with the noncontact values in order for the sample properties to be evaluated. The data analysis requires vibration models associated with the probe during contact in order for the beam response to be deconvolved from the measured spectra. To date, the majority of CR-AFM research has used rectangular probes that have a relatively simple vibration response. Recently, U-shaped AFM probes have created much interest because they allow local sample heating. However, the vibration response of these probes is much more complex such that CR-AFM is still in its infancy. In this article, a simplified analytical model of U-shaped probes is evaluated for contact resonance applications relative to a more complex finite element (FE) computational model. The tip-sample contact is modeled using three orthogonal Kelvin-Voigt elements such that the resonant frequency and peak width of each mode are functions of the contact conditions. For the purely elastic case, the frequency results of the simple model are within 8% of the FE model for the lowest six modes over a wide range of contact stiffness values. Results for the viscoelastic contact problem for which the quality factor of the lowest six modes is compared show agreement to within 13%. These results suggest that this simple model can be used effectively to evaluate CR-AFM experimental results during AFM scanning such that quantitative mapping of viscoelastic properties may be possible using U-shaped probes.

  14. Contact resonances of U-shaped atomic force microscope probes

    International Nuclear Information System (INIS)

    Recent approaches used to characterize the elastic or viscoelastic properties of materials with nanoscale resolution have focused on the contact resonances of atomic force microscope (CR-AFM) probes. The experiments for these CR-AFM methods involve measurement of several contact resonances from which the resonant frequency and peak width are found. The contact resonance values are then compared with the noncontact values in order for the sample properties to be evaluated. The data analysis requires vibration models associated with the probe during contact in order for the beam response to be deconvolved from the measured spectra. To date, the majority of CR-AFM research has used rectangular probes that have a relatively simple vibration response. Recently, U-shaped AFM probes have created much interest because they allow local sample heating. However, the vibration response of these probes is much more complex such that CR-AFM is still in its infancy. In this article, a simplified analytical model of U-shaped probes is evaluated for contact resonance applications relative to a more complex finite element (FE) computational model. The tip-sample contact is modeled using three orthogonal Kelvin-Voigt elements such that the resonant frequency and peak width of each mode are functions of the contact conditions. For the purely elastic case, the frequency results of the simple model are within 8% of the FE model for the lowest six modes over a wide range of contact stiffness values. Results for the viscoelastic contact problem for which the quality factor of the lowest six modes is compared show agreement to within 13%. These results suggest that this simple model can be used effectively to evaluate CR-AFM experimental results during AFM scanning such that quantitative mapping of viscoelastic properties may be possible using U-shaped probes

  15. Application of molecular probes in histopathology of communicable diseases

    International Nuclear Information System (INIS)

    The use of molecular probes in histopathology is based on the hybridization of labelled DNA and RNA probes with nucleic acid sequences in samples of diseased tissues. The main techniques are (1) in situ hybridization (ISH), where labelled probes are used to detect complementary DNA or RNA in histological sections, and (2) examination by Southern or other blotting techniques of nucleic acids extracted from homogenized biopsy material. Of these ISH enjoys better rapport with histopathologists because of its similarity to immunohistochemistry. It has the unique advantage over other molecular biology techniques of allowing localisation and visualisation of target nucleic acid sequences within morphologically identifiable cells or cellular structures. Probes for ISH may bear radioactive or non-radioactive labels. Isotopic probes (3H, 32P, 35S, 14C, 125I) are generally more sensitive than non-isotopic ones, although they are less stable and require longer processing times. Numerous non-isotopic labels have been explored; of these biotin and digoxigenin are the reporters of choice. In ISH, finding the optimal balance between good morphological preservation of cells (which is dependent on tissue fixation) and strong hybridization signals, is crucial. Tissues fixation and retention of cytoskeletal structures, unfortunately, impede diffusion of probes into tissues. ISH sensitivity is also influenced by inherent properties of the probe and hybridization conditions. Although ISH is largely a research tool in histopathology, it is already making strong inroads into diagnostic histopathology. It has been applied for the detection of CMV, HPV, HIV, JC virus, B19 parvovirus, HSV-1, EBV, HBV, hepatitis delta virus, Chlamydia trachomatis, salmonella and mycoplasma etc. Its application includes localisation of sites of infection, elucidation of mechanisms of virus transmission and dissemination and investigation of the link between virus infections and cancer. Demonstration of m

  16. Electron studies of acceleration processes in the corona. [solar probe mission planning

    Science.gov (United States)

    Lin, R. P.

    1978-01-01

    The solar probe mission can obtain unique and crucially important measurements of electron acceleration, storage, and propagation processes in the corona and can probe the magnetic field structure of the corona below the spacecraft. The various energetic electron phenomena which will be sampled by the Solar Probe are described and some new techniques to probe coronal structures are suggested.

  17. The detection of HBV DNA with gold nanoparticle gene probes

    Institute of Scientific and Technical Information of China (English)

    Dong Xi; Xiaoping Luo; Qin Ning; Qianghua Lu; Kailun Yao; Zuli Liu

    2007-01-01

    Objective:Gold nanoparticle Hepatitis B virus (HBV) DNA probes were prepared, and their application for HBV DNA measurement was studied. Methods:Alkanethiol modified oligonucleotide was bound with self-made Au nanoparticles to form nanoparticle HBV DNA gene probes, through covalent binding of Au-S. By using a fluorescence-based method, the number of thiol-derivatized, single-stranded oligonucleotides and their hybridization efficiency with complementary oligonucleotides in solution was determined. With the aid of Au nanoparticle-supported mercapto-modified oligonucleotides serving as detection probes, and oligonucleotides immobilized on a nylon membrane surface acting as capturing probes,HBV DNA was detected visually by sandwich hybridization based on highly sensitive aggregation and silver staining. The modified nanoparticle HBV DNA gene probes were also used to detect the HBV DNA extracted from serum in patients with hepatitis B. Results:Compared with bare Au nanoparticles, oligonucleotide modified nanoparticles had a higher stability in NaCl solution or under high temperature environment and the absorbance peak of modified Au nanoparticles shifted from 520nm to 524nm. For Au nanoparticles, the maximal oligonucleotide surface coverage of hexaethiol 30-mer oligonucleotide was (132 ± 10) oligonucleotides per nanoparticle, and the percentage of hybridization strands on nanoparticles was (22 ± 3% ). Based on a two-probe sandwich hybridization/nanoparticle amplification/silver staining enhancement method, Au nanoparticle gene probes could detect as low as 10-11 mol/L composite HBV DNA molecules on a nylon membrane and the PCR products of HBV DNA visually. As made evident by transmission electron microscopy, the nanoparticles assembled into large network aggregates when nanoparticle HBV DNA gene probes were applied to detect HBV DNA molecules in liquid. Conclusion:Our results showed that successfully prepared Au nanoparticle HBV DNA gene probes could be used to

  18. Work on Planetary Atmospheres and Planetary Atmosphere Probes

    Science.gov (United States)

    Lester, Peter

    1999-01-01

    A summary final report of work accomplished is presented. Work was performed in the following areas: (1) Galileo Probe science analysis, (2) Galileo probe Atmosphere Structure Instrument, (3) Mars Pathfinder Atmosphere Structure/Meteorology instrument, (4) Mars Pathfinder data analysis, (5) Science Definition for future Mars missions, (6) Viking Lander data analysis, (7) winds in Mars atmosphere Venus atmospheric dynamics, (8) Pioneer Venus Probe data analysis, (9) Pioneer Venus anomaly analysis, (10) Discovery Venus Probe Titan probe instrument design, and (11) laboratory studies of Titan probe impact phenomena. The work has resulted in more than 10 articles published in archive journals, 2 encyclopedia articles, and many working papers. This final report is organized around the four planets on which there was activity, Jupiter, Mars, Venus, and Titan, with a closing section on Miscellaneous Activities. A major objective was to complete the fabrication, test, and evaluation of the atmosphere structure experiment on the Galileo probe, and to receive, analyze and interpret data received from the spacecraft. The instrument was launched on April 14, 1989. Calibration data were taken for all experiment sensors. The data were analyzed, fitted with algorithms, and summarized in a calibration report for use in analyzing and interpreting data returned from Jupiter's atmosphere. The sensors included were the primary science pressure, temperature and acceleration sensors, and the supporting engineering temperature sensors. Computer programs were written to decode the Experiment Data Record and convert the digital numbers to physical quantities, i.e., temperatures, pressures, and accelerations. The project office agreed to obtain telemetry of checkout data from the probe. Work to extend programs written for use on the Pioneer Venus project included: (1) massive heat shield ablation leading to important mass loss during entry; and (2) rapid planet rotation, which introduced

  19. Probe technologies for clean sampling and measurement of subglacial lakes.

    Science.gov (United States)

    Mowlem, Matt; Saw, Kevin; Brown, Robin; Waugh, Edward; Cardwell, Christopher L; Wyatt, James; Magiopoulos, Iordanis; Keen, Peter; Campbell, Jon; Rundle, Nicholas; Gkritzalis-Papadopoulos, Athanasios

    2016-01-28

    It is 4 years since the subglacial lake community published its plans for accessing, sampling, measuring and studying the pristine, and hitherto enigmatic and very different, Antarctic subglacial lakes, Vostok, Whillans and Ellsworth. This paper summarizes the contrasting probe technologies designed for each of these subglacial environments and briefly updates how these designs changed or were used differently when compared to previously published plans. A detailed update on the final engineering design and technical aspects of the probe for Subglacial Lake Ellsworth is presented. This probe is designed for clean access, is negatively buoyant (350 kg), 5.2 m long, 200 mm in diameter, approximately cylindrical and consists of five major units: (i) an upper power and communications unit attached to an optical and electrical conducting tether, (ii)-(iv) three water and particle samplers, and (v) a sensors, imaging and instrumentation pack tipped with a miniature sediment corer. To date, only in Subglacial Lake Whillans have instruments been successfully deployed. Probe technologies for Subglacial Lake Vostok (2014/15) and Lake Ellsworth (2012/13) were not deployed for technical reasons, in the case of Lake Ellsworth because hot-water drilling was unable to access the lake during the field season window. Lessons learned and opportunities for probe technologies in future subglacial access missions are discussed.

  20. Coherence specific signal detection via chiral pump-probe spectroscopy.

    Science.gov (United States)

    Holdaway, David I H; Collini, Elisabetta; Olaya-Castro, Alexandra

    2016-05-21

    We examine transient circular dichroism (TRCD) spectroscopy as a technique to investigate signatures of exciton coherence dynamics under the influence of structured vibrational environments. We consider a pump-probe configuration with a linearly polarized pump and a circularly polarized probe, with a variable angle θ between the two directions of propagation. In our theoretical formalism the signal is decomposed in chiral and achiral doorway and window functions. Using this formalism, we show that the chiral doorway component, which beats during the population time, can be isolated by comparing signals with different values of θ. As in the majority of time-resolved pump-probe spectroscopy, the overall TRCD response shows signatures of both excited and ground state dynamics. However, we demonstrate that the chiral doorway function has only a weak ground state contribution, which can generally be neglected if an impulsive pump pulse is used. These findings suggest that the pump-probe configuration of optical TRCD in the impulsive limit has the potential to unambiguously probe quantum coherence beating in the excited state. We present numerical results for theoretical signals in an example dimer system. PMID:27208941

  1. Experimental facility and void fraction calibration methods for impedance probes

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Fernando L. de; Rocha, Marcelo S., E-mail: floliveira@ipen.br, E-mail: msrocha@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2013-07-01

    An experimental facility was designed and constructed with aims of to calibrate a capacitance probe for gas-liquid flow void fraction measurements. The facility is composed of a metallic hack with a vertical 2,300 mm high glass tube with 38 mm ID with stagnant water and compressed air bubbling system simulating the gas phase (vapor). At the lower part, a mixing section with a porous media element releases the air bubbles into the water, and the compressed air flow is measured by two calibrated rotameters. At the upper part a stagnant water tank separates the liquid and gas. Two pressure taps are located near the lower and upper sides of the glass tube for pressure difference measurement. The pressure difference is used for low void fraction values (0-15%) calibration methods, as described in the work. Two electrically controlled quick closing valves are installed between the porous media element and the upward separation tank for high void fraction values measurement (15-50%) used to calibrate the capacitance probe. The experimental facility design, construction, capacitance probe calibration methods and results, as well as flow pattern visualization, are presented. Finally, the capacitance probe will be installed on a natural circulation circuit mounted at the Nuclear Engineering Center (CEN/IPEN/CNEN-SP) for measurement of the instantaneous bulk void. Instantaneous signals generated by the capacitance probe will allow the determination of natural circulation loop global energy balance. (author)

  2. Auroral Spatial Structures Probe Sub-Orbital Mission Preliminary Results

    Science.gov (United States)

    Pratt, J.; Swenson, C.; Martineau, R. J.; Fish, C. S.; Conde, M.; Hampton, D.; Crowley, G.

    2015-12-01

    The NASA Auroral Spatial Structures Probe, 49.002, was launched January 28, 2015 from the Poker Flat Research Range into active aurora over the northern coast of Alaska. The primary objective of this mission was to determine the contribution of small spatial and temporal scale fluctuations of the electric fields to the larger-scale energy deposition processes associated with the aurora. The Auroral Spatial Structures Probe Sub-Orbital Mission consisted of a formation of 7 spacecraft (a main payload with 6 deployable sub-payloads) designed for multiple temporally spaced co-located measurements of electric and magnetic fields in the earth's ionosphere. The mission was able to make observations at a short time scale and small spatial scale convergence that is unobservable by either satellite or ground-based observations. The payloads included magnetometers, electric field double probes, and Langmuir probes as well as a sweeping impedance probe on the main payload. We present here preliminary results from the measurements taken that hint at the underlying spatial structure of the currents and energy deposition in the aurora. The Poynting flux derived from the observations is shown and implications are discussed in terms of the contribution of small spatial scale, rapid temporal scale fluctuations in the currents that deposit energy in the auroral region. Funding provided by NASA Grants NNX11AE23G and NNX13AN20A.

  3. Multi-channel micro neural probe fabricated with SOI

    Institute of Scientific and Technical Information of China (English)

    PEI WeiHua; ZHU Lin; WANG ShuJing; GUO Kai; TANG Jun; ZHANG Xu; LU Lin; GAO ShangKai; CHEN HongDa

    2009-01-01

    Silicon-on-insulator (SOI) substrate is widely used in micro-electro-mechanical systems (MEMS). With the buried oxide layer of SOl acting as an etching stop, silicon based micro neural probe can be fabri-cated with improved uniformity and manufacturability. A seven-record-site neural probe was formed by inductive-coupled plasma (ICP) dry etching of an SOl substrate. The thickness of the probe is 15 μm.The shaft of the probe has dimensions of 3 mmx100 μmx15 μm with typical area of the record site of 78.5 μm2. The impedance of the record site was measured in-vitro. The typical impedance characteris-tics of the record sites are around 2 MΩ at 1 kHz. The performance of the neural probe in-vivo was tested on anesthetic rat. The recorded neural spike was typically around 140 μV. Spike from individual site could exceed 700 μV. The average signal noise ratio was 7 or more.

  4. Thermal scanning probe microscopy in the development of pharmaceuticals.

    Science.gov (United States)

    Dai, Xuan; Moffat, Jonathan G; Wood, John; Reading, Mike

    2012-04-01

    The ability to characterize the physical and chemical properties of dosage forms is crucial to a more complete understanding of how vehicles for drug delivery behave and therefore how effective they are. Spatially resolved characterization that enables the visualization of properties on the nanoscale is particularly powerful. The usefulness of scanning probe microscopy (SPM) in the field of drug delivery is becoming increasingly well established and the use of thermal probes offers new capabilities thus enabling SPM to provide more and sometimes unique information. One type of measurement enabled by thermal probes is determining transition temperatures by means of local thermal analysis. The ability to identify and characterize materials in this way has found applications in characterizing a wide range of dosage forms. A complimentary thermal probe technique is photothermal infrared microspectroscopy (PTMS). PTMS offers a variety of advantages over more conventional approaches including the ability analyze compacts without the need for thin sections. It is also able to achieve sub-micron spatial resolution. Thermal probe techniques can characterize pharmaceutical dosage forms in terms of their physical properties and their chemical composition. PMID:21856345

  5. Flexible, Penetrating Brain Probes Enabled by Advances in Polymer Microfabrication

    Directory of Open Access Journals (Sweden)

    Ahuva Weltman

    2016-10-01

    Full Text Available The acquisition of high-fidelity, long-term neural recordings in vivo is critically important to advance neuroscience and brain–machine interfaces. For decades, rigid materials such as metal microwires and micromachined silicon shanks were used as invasive electrophysiological interfaces to neurons, providing either single or multiple electrode recording sites. Extensive research has revealed that such rigid interfaces suffer from gradual recording quality degradation, in part stemming from tissue damage and the ensuing immune response arising from mechanical mismatch between the probe and brain. The development of “soft” neural probes constructed from polymer shanks has been enabled by advancements in microfabrication; this alternative has the potential to mitigate mismatch-related side effects and thus improve the quality of recordings. This review examines soft neural probe materials and their associated microfabrication techniques, the resulting soft neural probes, and their implementation including custom implantation and electrical packaging strategies. The use of soft materials necessitates careful consideration of surgical placement, often requiring the use of additional surgical shuttles or biodegradable coatings that impart temporary stiffness. Investigation of surgical implantation mechanics and histological evidence to support the use of soft probes will be presented. The review concludes with a critical discussion of the remaining technical challenges and future outlook.

  6. SECURE SERVICE DISCOVERY BASED ON PROBE PACKET MECHANISM FOR MANETS

    Directory of Open Access Journals (Sweden)

    S. Pariselvam

    2015-03-01

    Full Text Available In MANETs, Service discovery process is always considered to be crucial since they do not possess a centralized infrastructure for communication. Moreover, different services available through the network necessitate varying categories. Hence, a need arises for devising a secure probe based service discovery mechanism to reduce the complexity in providing the services to the network users. In this paper, we propose a Secure Service Discovery Based on Probe Packet Mechanism (SSDPPM for identifying the DoS attack in MANETs, which depicts a new approach for estimating the level of trust present in each and every routing path of a mobile ad hoc network by using probe packets. Probing based service discovery mechanisms mainly identifies a mobile node’s genuineness using a test packet called probe that travels the entire network for the sake of computing the degree of trust maintained between the mobile nodes and it’s attributed impact towards the network performance. The performance of SSDPPM is investigated through a wide range of network related parameters like packet delivery, throughput, Control overhead and total overhead using the version ns-2.26 network simulator. This mechanism SSDPPM, improves the performance of the network in an average by 23% and 19% in terms of packet delivery ratio and throughput than the existing service discovery mechanisms available in the literature.

  7. Fabrication of all diamond scanning probes for nanoscale magnetometry

    Science.gov (United States)

    Appel, Patrick; Neu, Elke; Ganzhorn, Marc; Barfuss, Arne; Batzer, Marietta; Gratz, Micha; Tschöpe, Andreas; Maletinsky, Patrick

    2016-06-01

    The electronic spin of the nitrogen vacancy (NV) center in diamond forms an atomically sized, highly sensitive sensor for magnetic fields. To harness the full potential of individual NV centers for sensing with high sensitivity and nanoscale spatial resolution, NV centers have to be incorporated into scanning probe structures enabling controlled scanning in close proximity to the sample surface. Here, we present an optimized procedure to fabricate single-crystal, all-diamond scanning probes starting from commercially available diamond and show a highly efficient and robust approach for integrating these devices in a generic atomic force microscope. Our scanning probes consisting of a scanning nanopillar (200 nm diameter, 1-2 μm length) on a thin (50 ± 20 nT / √{ Hz } ). As a first application of our scanning probes, we image the magnetic stray field of a single Ni nanorod. We show that this stray field can be approximated by a single dipole and estimate the NV-to-sample distance to a few tens of nanometer, which sets the achievable resolution of our scanning probes.

  8. Synthesis and fluorescence characteristics of ATP-based FRET probes.

    Science.gov (United States)

    Hardt, Norman; Hacker, Stephan M; Marx, Andreas

    2013-12-28

    Adenosine triphosphate (ATP) analogues labelled with two dyes suitable for undergoing Förster Resonance Energy Transfer (FRET) have the potential to be valuable tools to continuously study the enzymatic activity of ATP consuming enzymes. Here, we present a synthesis strategy that allows obtaining these ATP analogues in a straight-forward manner. Earlier studies indicate that modifying ATP at the O2'- and the γ-position is a very promising starting point for the design of these probes. We synthesized probes modified with five different combinations of dyes attached to these positions and investigated their fluorescence characteristics in the non-cleaved state as well as after enzymatic hydrolysis. All presented probes largely change their fluorescence characteristics upon cleavage. They include ratiometric FRET probes as well as dark quenched analogues. For typical in vitro applications a combination of the sulfonated polymethine dyes Sulfo-Cy3 and Sulfo-Cy5 seems to be most promising due to their excellent solubility in aqueous buffer and a large change of fluorescence characteristics upon cleavage. For this combination of dyes we also synthesized analogues modified at the γ- and the C2- or the O3'-position, respectively, as these attachment sites are also well accepted by certain ATP consuming enzymes. These analogues show comparably large changes in fluorescence characteristics. Overall, we present new ATP-based FRET probes that have the potential to enable monitoring the enzymatic activity of ATP consuming enzymes. PMID:24173528

  9. Van Allen Probes Science Gateway: A Centralized Data Access Point

    Science.gov (United States)

    Romeo, G.; Barnes, R. J.; Ukhorskiy, A. Y.; Sotirelis, T.; Stephens, G. K.; Kessel, R.; Potter, M.

    2015-12-01

    The Van Allen Probes Science Gateway acts a centralized interface to the instrument Science Operation Centers (SOCs), provides mission planning tools, and hosts a number of science related activities such as the mission bibliography. Most importantly, the Gateway acts as the primary site for processing and delivering the Van Allen Probes Space Weather data to users. Over the past years, the web-site has been completely redesigned with the focus on easier navigation and improvements of the existing tools such as the orbit plotter, position calculator and magnetic footprint tool. In addition, a new data plotting facility has been added. Based on HTML5, which allows users to interactively plot Van Allen Probes science and space weather data. The user can tailor the tool to display exactly the plot they wish to see and then share this with other users via either a URL or by QR code. Various types of plots can be created, including, simple time series, data plotted as a function of orbital location, and time versus L-Shell, capability of visualizing data from both probes (A & B) on the same plot. In cooperation with all Van Allen Probes Instrument SOCs, the Science Gateway will soon be able to serve higher level data products (Level 3), and to visualize them via the above mentioned HTML5 interface. Users will also be able to create customized CDF files on the fly.

  10. Luminescent probes for detection and imaging of hydrogen peroxide

    International Nuclear Information System (INIS)

    The relevance of hydrogen peroxide (H2O2) in biological processes has been underestimated for a long time. In recent years, various reports showed that H2O2 not only acts as a cytotoxic compound appearing in the course of oxidative stress, but also functions as an important signaling molecule. Fluorescent probes (or indicators) and nanoparticles that respond selectively to hydrogen peroxide can be applied for intracellular measurements or in vivo imaging, and are superior to electrochemical methods, e. g. in terms of spatial resolution. In contrast to previous reviews that concentrated on the adoption of different probes for certain applications, this survey highlights the basic principles of different probes in terms of their chemical design, structures and functionalities. Thus, the probes are classified according to the underlying reaction mechanism: oxidation, hydrolysis, photoinduced electron transfer, and lanthanide complexation. Other assays are based on fluorescent proteins and nanoparticles, and chemi-or bioluminescent reagents. We confine this review to probes that display a more or less distinct selectivity to hydrogen peroxide. Indicators responding to reactive oxygen species (ROS) in general, or to particular other ROS, are not covered. Finally, we briefly discuss future trends and perspectives of these luminescent reporters in biomedical research and imaging. (author)

  11. DNA Probe Pooling for Rapid Delineation of Chromosomal Breakpoints

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Chun-Mei; Kwan, Johnson; Baumgartner, Adolf; Weier, Jingly F.; Wang, Mei; Escudero, Tomas; Munne' , Santiago; Zitzelsberger, Horst F.; Weier, Heinz-Ulrich

    2009-01-30

    Structural chromosome aberrations are hallmarks of many human genetic diseases. The precise mapping of translocation breakpoints in tumors is important for identification of genes with altered levels of expression, prediction of tumor progression, therapy response, or length of disease-free survival as well as the preparation of probes for detection of tumor cells in peripheral blood. Similarly, in vitro fertilization (IVF) and preimplantation genetic diagnosis (PGD) for carriers of balanced, reciprocal translocations benefit from accurate breakpoint maps in the preparation of patient-specific DNA probes followed by a selection of normal or balanced oocytes or embryos. We expedited the process of breakpoint mapping and preparation of case-specific probes by utilizing physically mapped bacterial artificial chromosome (BAC) clones. Historically, breakpoint mapping is based on the definition of the smallest interval between proximal and distal probes. Thus, many of the DNA probes prepared for multi-clone and multi-color mapping experiments do not generate additional information. Our pooling protocol described here with examples from thyroid cancer research and PGD accelerates the delineation of translocation breakpoints without sacrificing resolution. The turnaround time from clone selection to mapping results using tumor or IVF patient samples can be as short as three to four days.

  12. Development of a novel gamma probe for detecting radiation direction

    Science.gov (United States)

    Pani, R.; Pellegrini, R.; Cinti, M. N.; Longo, M.; Donnarumma, R.; D'Alessio, A.; Borrazzo, C.; Pergola, A.; Ridolfi, S.; De Vincentis, G.

    2016-01-01

    Spatial localization of radioactive sources is currently a main issue interesting different fields, including nuclear industry, homeland security as well as medical imaging. It is currently achieved using different systems, but the development of technologies for detecting and characterizing radiation is becoming important especially in medical imaging. In this latter field, radiation detection probes have long been used to guide surgery, thanks to their ability to localize and quantify radiopharmaceutical uptake even deep in tissue. Radiolabelled colloid is injected into, or near to, the tumor and the surgeon uses a hand-held radiation detector, the gamma probe, to identify lymph nodes with radiopharmaceutical uptkake. The present work refers to a novel scintigraphic goniometric probe to identify gamma radiation and its direction. The probe incorporates several scintillation crystals joined together in a particular configuration to provide data related to the position of a gamma source. The main technical characteristics of the gamma locator prototype, i.e. sensitivity, spatial resolution and detection efficiency, are investigated. Moreover, the development of a specific procedure applied to the images permits to retrieve the source position with high precision with respect to the currently used gamma probes. The presented device shows a high sensitivity and efficiency to identify gamma radiation taking a short time (from 30 to 60 s). Even though it was designed for applications in radio-guided surgery, it could be used for other purposes, as for example homeland security.

  13. Coherence specific signal detection via chiral pump-probe spectroscopy.

    Science.gov (United States)

    Holdaway, David I H; Collini, Elisabetta; Olaya-Castro, Alexandra

    2016-05-21

    We examine transient circular dichroism (TRCD) spectroscopy as a technique to investigate signatures of exciton coherence dynamics under the influence of structured vibrational environments. We consider a pump-probe configuration with a linearly polarized pump and a circularly polarized probe, with a variable angle θ between the two directions of propagation. In our theoretical formalism the signal is decomposed in chiral and achiral doorway and window functions. Using this formalism, we show that the chiral doorway component, which beats during the population time, can be isolated by comparing signals with different values of θ. As in the majority of time-resolved pump-probe spectroscopy, the overall TRCD response shows signatures of both excited and ground state dynamics. However, we demonstrate that the chiral doorway function has only a weak ground state contribution, which can generally be neglected if an impulsive pump pulse is used. These findings suggest that the pump-probe configuration of optical TRCD in the impulsive limit has the potential to unambiguously probe quantum coherence beating in the excited state. We present numerical results for theoretical signals in an example dimer system.

  14. Electrochemical Quantification of Single Nucleotide Polymorphisms Using Nanoparticle Probes

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Guodong; Lin, Yuehe

    2007-08-29

    We report a new approach for electrochemical quantification of single-nucleotide polymorphisms (SNPs) using nanoparticle probes. The principle is based on DNA polymerase I (klenow fragment)-induced coupling of the nucleotide-modified nanoparticle probe to the mutant sites of duplex DNA under the Watson-Crick base pairing rule. After liquid hybridization events occurred among biotinylated DNA probes, mutant DNA, and complementary DNA, the resulting duplex DNA helixes were captured to the surface of magnetic beads through a biotin-avidin affinity reaction and magnetic separation. A cadmium phosphate-loaded apoferritin nanoparticle probe, which is modified with nucleotides and is complementary to the mutant site, is coupled to the mutant sites of the formed duplex DNA in the presence of DNA polymerase. Subsequent electrochemical stripping analysis of the cadmium component of coupled nanoparticle probes provides a means to quantify the concentration of mutant DNA. The method is sensitive enough to detect 21.5 attomol mutant DNA, which will enable the quantitative analysis of nucleic acid without polymerase chain reaction pre-amplification. The approach was challenged with constructed samples containing mutant and complementary DNA. The results indicated that it was possible to accurately determine SNPs with frequencies as low 0.01. The proposed approach has a great potential for realizing an accurate, sensitive, rapid, and low-cost method of SNP detection.

  15. Fabrication of all diamond scanning probes for nanoscale magnetometry.

    Science.gov (United States)

    Appel, Patrick; Neu, Elke; Ganzhorn, Marc; Barfuss, Arne; Batzer, Marietta; Gratz, Micha; Tschöpe, Andreas; Maletinsky, Patrick

    2016-06-01

    The electronic spin of the nitrogen vacancy (NV) center in diamond forms an atomically sized, highly sensitive sensor for magnetic fields. To harness the full potential of individual NV centers for sensing with high sensitivity and nanoscale spatial resolution, NV centers have to be incorporated into scanning probe structures enabling controlled scanning in close proximity to the sample surface. Here, we present an optimized procedure to fabricate single-crystal, all-diamond scanning probes starting from commercially available diamond and show a highly efficient and robust approach for integrating these devices in a generic atomic force microscope. Our scanning probes consisting of a scanning nanopillar (200 nm diameter, 1-2 μm length) on a thin (magnetic field sensitivity (ηAC≈50±20nT/Hz). As a first application of our scanning probes, we image the magnetic stray field of a single Ni nanorod. We show that this stray field can be approximated by a single dipole and estimate the NV-to-sample distance to a few tens of nanometer, which sets the achievable resolution of our scanning probes. PMID:27370455

  16. Theory and practice of the FFT/matrix inversion technique for probe-corrected spherical near-field antenna measurements with high-order probes

    DEFF Research Database (Denmark)

    Laitinen, Tommi; Pivnenko, Sergey; Nielsen, Jeppe Majlund;

    2010-01-01

    A complete antenna pattern characterization procedure for spherical near-field antenna measurements employing a high-order probe and a full probe correction is described. The procedure allows an (almost) arbitrary antenna to be used as a probe. Different measurement steps of the procedure and the...... associated data processing are described in detail, and comparison to the existing procedure employing a first-order probe is made. The procedure is validated through measurements....

  17. Depth Probing Soft X-ray Microprobe (DPSXRM) for High Resolution Probing of Earth's Microstructural Samples

    Science.gov (United States)

    Dikedi, P. N.

    2015-12-01

    The Cambrian explosion; occurrence of landslides in very dry weather conditions; rockslides; dead, shriveled-up and crumbled leaves possessing fossil records with the semblance of well preserved, flat leaves; abundance of trilobite tracks in lower and higher rock layers; and sailing stones are enigmas demanding demystifications. These enigmas could be elucidated when data on soil structure, texture and strength are provided by some device with submicrometre accuracy; for these and other reasons, the design of a Depth Probing Soft X-ray Microprobe (DPSXRM), is being proposed; it is expected to deliver soft X-rays, at spatial resolution, ϛ≥600nm and to probe at the depth of 0.5m in 17s. The microprobe is portable compared to a synchrotron radiation facility (Diamond Light Source has land size of 43,300m2); spatial resolution,ϛ , of the DPSXRM surpasses those of the X-ray Fluorescence microanalysis (10µm), electron microprobe (1-3µm) and ion microprobe (5->30µm); the DPSXRM has allowance for multiple targets. Vanadium and Manganese membranes are proposed owing to respective 4.952KeV VKα1 and 5.899KeV MnKα1 X-rays emitted, which best suits micro-probing of Earth's microstructural samples. Compound systems like the Kirk-Patrick and Baez and Wolter optics, aspheric mirrors like elliptical and parabolic optics, small apertures and Abbe sine condition are employed to reduce or remove astigmatism, obliquity, comatic and spherical aberrations—leading to good image quality. Results show that 5.899KeV MnKα1 and 4.952KeV VKα1 soft X-rays will travel a distance of 2.75mm to form circular patches of radii 2.2mm and 2.95mm respectively. Zone plate with nth zone radius of 1.5mm must be positioned 1.5mm and 2mm from the electron gun if circular patches must be formed from 4.952KeV VKα1 and 5.899KeV MnKα1 soft X-rays respectively. The focal lengths of 0.25μm≤ƒ≤1.50μm and 0.04μm≤ƒ≤0.2μm covered by 4.952KeV VKα1 and 5.899KeV Mn Kα1 soft X-Rays, will

  18. A verification protocol for the probe sequences of Affymetrix genome arrays reveals high probe accuracy for studies in mouse, human and rat

    NARCIS (Netherlands)

    Alberts, Rudi; Terpstra, Peter; Hardonk, Menno; Bystrykh, Leonid V.; de Haan, Gerald; Breitling, Rainer; Nap, Jan-Peter; Jansen, Ritsert C.

    2007-01-01

    Background: The Affymetrix GeneChip technology uses multiple probes per gene to measure its expression level. Individual probe signals can vary widely, which hampers proper interpretation. This variation can be caused by probes that do not properly match their target gene or that match multiple gene

  19. A verification protocol for the probe sequences of Affymetrix genome arrays reveals high probe accuracy for studies in mouse, human and rat

    NARCIS (Netherlands)

    Alberts, R.; Terpstra, P.; Hardonk, M.; Bystrykh, L.V.; Haan, de G.; Breitling, R.; Nap, J.P.H.; Jansen, R.C.

    2007-01-01

    Background - The Affymetrix GeneChip technology uses multiple probes per gene to measure its expression level. Individual probe signals can vary widely, which hampers proper interpretation. This variation can be caused by probes that do not properly match their target gene or that match multiple gen

  20. Direct and quantitative broadband absorptance spectroscopy with multilayer cantilever probes

    Science.gov (United States)

    Hsu, Wei-Chun; Tong, Jonathan Kien-Kwok; Liao, Bolin; Chen, Gang

    2015-04-21

    A system for measuring the absorption spectrum of a sample is provided that includes a broadband light source that produces broadband light defined within a range of an absorptance spectrum. An interferometer modulates the intensity of the broadband light source for a range of modulation frequencies. A bi-layer cantilever probe arm is thermally connected to a sample arm having at most two layers of materials. The broadband light modulated by the interferometer is directed towards the sample and absorbed by the sample and converted into heat, which causes a temperature rise and bending of the bi-layer cantilever probe arm. A detector mechanism measures and records the deflection of the probe arm so as to obtain the absorptance spectrum of the sample.