21 CFR 880.2920 - Clinical mercury thermometer.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Clinical mercury thermometer. 880.2920 Section 880... Devices § 880.2920 Clinical mercury thermometer. (a) Identification. A clinical mercury thermometer is a... mercury. (b) Classification. Class II (special controls). The device is exempt from the premarket...

Genetically encoded ratiometric fluorescent thermometer with wide range and rapid response.

Directory of Open Access Journals (Sweden)

Masahiro Nakano

Full Text Available Temperature is a fundamental physical parameter that plays an important role in biological reactions and events. Although thermometers developed previously have been used to investigate several important phenomena, such as heterogeneous temperature distribution in a single living cell and heat generation in mitochondria, the development of a thermometer with a sensitivity over a wide temperature range and rapid response is still desired to quantify temperature change in not only homeotherms but also poikilotherms from the cellular level to in vivo. To overcome the weaknesses of the conventional thermometers, such as a limitation of applicable species and a low temporal resolution, owing to the narrow temperature range of sensitivity and the thermometry method, respectively, we developed a genetically encoded ratiometric fluorescent temperature indicator, gTEMP, by using two fluorescent proteins with different temperature sensitivities. Our thermometric method enabled a fast tracking of the temperature change with a time resolution of 50 ms. We used this method to observe the spatiotemporal temperature change between the cytoplasm and nucleus in cells, and quantified thermogenesis from the mitochondria matrix in a single living cell after stimulation with carbonyl cyanide 4-(trifluoromethoxyphenylhydrazone, which was an uncoupler of oxidative phosphorylation. Moreover, exploiting the wide temperature range of sensitivity from 5°C to 50°C of gTEMP, we monitored the temperature in a living medaka embryo for 15 hours and showed the feasibility of in vivo thermometry in various living species.

Development of a superconducting transition edge thermometer for calorimetric detection of heavy ions

Energy Technology Data Exchange (ETDEWEB)

Meier, J; Boehmer, W; Egelhof, P; Henning, W; Kienlin, A v [Gesellschaft fuer Schwerionenforschung mbH, Darmstadt (Germany) Mainz Univ. (Germany). Inst. fuer Physik; Shepard, K W [Argonne National Lab., IL (United States)

1991-10-01

A low temperature bolometer for the calorimetric detection of heavy ions was constructed and tested. An aluminium thin-film microstrip, patterned in a meander-line structure by photolithographic techniques, serves as superconducting transition edge thermometer on a sapphire absorber. A transition width {delta}T of the thermometer of the order of some mK, and a resistance of up to R{sub c} = 60 k{Omega} at the working point (T{sub c} {approx equal} 1.5 K) is achieved. In tests with {alpha}-particles signals of typically 1 V pulseheight after the preamplifier and decaytimes around hundred {mu}s were observed. For 5.5 MeV {alpha}-particles the measured energy resolution is {Delta}E = 50 keV, corresponding to a temperature resolution of about 1 {mu}K. First measurements were performed with {sup 20}Ne ions (E = 116 MeV). The dependence of the pulseheight and the FWHM on the working point were investigated and qualitatively explained. The best energy resolution was {Delta}E = 2.6 MeV; most probably the present limitations are determined by the temperature stabilization. (orig.).

Reef coral δ18O thermometer in Hainan island waters, south China sea

International Nuclear Information System (INIS)

He Xuexian; Peng Zicheng; Wang Zhaorong; Huo Weiguo; Tan Jun; Nie Baofu; Chen Tegu; Zhong Jinliang

2000-01-01

An 18-year-long (1981-1998) study was conducted in Hainan Island waters (22 degree 22'N, 110 degree 39'E) to determine the relationship between δ 18 O in skeletal aragonite carbonate and sea surface temperature (SST) in porites lutea of reef-building corals. δ 18 O values in skeletal aragonite carbonate were measured by means of mass spectrometry. Coral samples grew at 5 m depth at Longwan Bay. Monthly measurements of the SST from 1960 to 1998 were taken at Qinglan Bay adjacent to the place of the collected samples. The thermometer shows that SST = -4.16 δ 18 O PDB + 4.9 (r = 0.80) and dδ 18 O/dT = -0.24 per mil/degree C. The δ 18 O thermometer is strongly influenced by the rainfall and runoff. Using the thermometer, the SST in the past hundred years with monthly resolution will be reconstructed and the climatic change in the northern area of South China Sea will be hind cast

A portable storage maximum thermometer

International Nuclear Information System (INIS)

Fayart, Gerard.

1976-01-01

A clinical thermometer storing the voltage corresponding to the maximum temperature in an analog memory is described. End of the measurement is shown by a lamp switch out. The measurement time is shortened by means of a low thermal inertia platinum probe. This portable thermometer is fitted with cell test and calibration system [fr

Model for cryogenic particle detectors with superconducting phase transition thermometers

International Nuclear Information System (INIS)

Proebst, F.; Frank, M.; Cooper, S.; Colling, P.; Dummer, D.; Ferger, P.; Nucciotti, A.; Seidel, W.; Stodolsky, L.

1994-09-01

We present data on a detector composed of an 18 g Si crystal and a superconducting phase transition thermometer which could be operated over a wide temperature range. An energy resolution of 1 keV (FWHM) has been obtained for 60 keV photons. The signals consist of two components: A fast one and a slow one, with decay times of 1.5 ms and 30-60 ms, respectively. In this paper we present a simple model which takes thermal and non-thermal phonon processes into account and provides a description of the observed temperature dependence of the pulse shape. The fast component, which completely dominates the signal at low temperatures, is due to high-frequency non-thermal phonons being absorbed in the thermometer. Thermalization of these phonons then leads to a temperature rise of the absorber, which causes the slow thermal component. At the highest operating temperatures (T∼80 mK) the amplitude of the slow component is roughly as expected from the heat capacity of the absorber. The strong suppression of the slow component at low temperatures is explained mostly as a consequence of the weak thermal coupling between electrons and phonons in the thermometer at low temperatures. (orig.)

A silicon nanowire heater and thermometer

Science.gov (United States)

Zhao, Xingyan; Dan, Yaping

2017-07-01

In the thermal conductivity measurements of thermoelectric materials, heaters and thermometers made of the same semiconducting materials under test, forming a homogeneous system, will significantly simplify fabrication and integration. In this work, we demonstrate a high-performance heater and thermometer made of single silicon nanowires (SiNWs). The SiNWs are patterned out of a silicon-on-insulator wafer by CMOS-compatible fabrication processes. The electronic properties of the nanowires are characterized by four-probe and low temperature Hall effect measurements. The I-V curves of the nanowires are linear at small voltage bias. The temperature dependence of the nanowire resistance allows the nanowire to be used as a highly sensitive thermometer. At high voltage bias, the I-V curves of the nanowire become nonlinear due to the effect of Joule heating. The temperature of the nanowire heater can be accurately monitored by the nanowire itself as a thermometer.

Cryogenic Thermometer Calibration Facility at CERN

CERN Document Server

Balle, C; Thermeau, J P

1998-01-01

A cryogenic thermometer calibration facility has been designed and is being commissioned in preparation for the very stringent requirements on the temperature control of the LHC superconducting magnets. The temperature is traceable in the 1.5 to 30 K range to standards maintained in a national metrological laboratory by using a set of Rhodium-Iron temperature sensors of metrological quality. The calibration facility is designed for calibrating simultaneously 60 industrial cryogenic thermometers in the 1.5 K to 300 K temperature range, a thermometer being a device that includes both a temperature sensor and the wires heat-intercept. The thermometers can be calibrated in good and degraded vacuum or immersed in the surrounding fluid and at different Joule self-heating conditions that match those imposed by signal conditioners used in large cryogenic machinery. The calibration facility can be operated in an automatic mode and all the control and safety routines are handled by a Programmable Logic Controller (PLC)...

High-resolution noncontact AFM and Kelvin probe force microscopy investigations of self-assembled photovoltaic donor–acceptor dyads

Directory of Open Access Journals (Sweden)

Benjamin Grévin

2016-06-01

Full Text Available Self-assembled donor–acceptor dyads are used as model nanostructured heterojunctions for local investigations by noncontact atomic force microscopy (nc-AFM and Kelvin probe force microscopy (KPFM. With the aim to probe the photo-induced charge carrier generation, thin films deposited on transparent indium tin oxide substrates are investigated in dark conditions and upon illumination. The topographic and contact potential difference (CPD images taken under dark conditions are analysed in view of the results of complementary transmission electron microscopy (TEM experiments. After in situ annealing, it is shown that the dyads with longer donor blocks essentially lead to standing acceptor–donor lamellae, where the acceptor and donor groups are π-stacked in an edge-on configuration. The existence of strong CPD and surface photo-voltage (SPV contrasts shows that structural variations occur within the bulk of the edge-on stacks. SPV images with a very high lateral resolution are achieved, which allows for the resolution of local photo-charging contrasts at the scale of single edge-on lamella. This work paves the way for local investigations of the optoelectronic properties of donor–acceptor supramolecular architectures down to the elementary building block level.

Examination of biogenic selenium-containing nanosystems based on polyelectrolyte complexes by atomic force, Kelvin probe force and electron microscopy methods

Energy Technology Data Exchange (ETDEWEB)

Sukhanova, T. E., E-mail: tat-sukhanova@mail.ru; Vylegzhanina, M. E.; Valueva, S. V.; Volkov, A. Ya.; Kutin, A. A. [Institute of Macromolecular Compounds RAS, 199004 Bolshoy Pr., 31, St.-Petersburg (Russian Federation); Temiryazeva, M. P.; Temiryazev, A. G. [Kotel’nikov Institute of Radio Engineering and Electronics (Fryazino Branch) Russian Academy of Sciences, Fryazino, Moscow region, 141190 (Russian Federation)

2016-06-17

The morphology and electrical properties of biogenic selenium-containing nanosystems based on polyelectrolyte complexes (PECs) were examined using AFM, Kelvin Probe Force and electron microscopy methods. It has been found, that prepared nanostructures significantly differed in their morphological types and parameters. In particular, multilayers capsules can be produced via varying synthesis conditions, especially, the selenium–PEC mass ratio ν. At the “special point” (ν = 0.1), filled and hollow nano- and microcapsules are formed in the system. The multilayer character of the capsules walls is visible in the phase images. Kelvin Probe Force images showed the inhomogeneity of potential distribution in capsules and outside them.

Kelvin Life, Labours and Legacy

CERN Document Server

Flood, Raymond; Whitaker, Andrew

2008-01-01

Lord Kelvin was one of the greatest physicists of the Victorian era. Widely known for the development of the Kelvin scale of temperature measurement, Kelvin's interests ranged across thermodynamics, the age of the Earth, the laying of the first transatlantic telegraph cable, not to mention inventions such as an improved maritime compass and a sounding device which allowed depths to be taken both quickly and while the ship was moving. He was an academic engaged in fundamentalresearch, while also working with industry and technological advances. He corresponded and collaborated with other eminen

Design of a Toolbox of RNA Thermometers.

Science.gov (United States)

Sen, Shaunak; Apurva, Divyansh; Satija, Rohit; Siegal, Dan; Murray, Richard M

2017-08-18

Biomolecular temperature sensors can be used for efficient control of large-volume bioreactors, for spatiotemporal imaging and control of gene expression, and to engineer robustness to temperature in biomolecular circuit design. Although RNA-based sensors, called "thermometers", have been investigated in both natural and synthetic contexts, an important challenge is to design diverse responses to temperature differing in sensitivity and threshold. We address this issue by constructing a library of RNA thermometers based on thermodynamic computations and experimentally measuring their activities in cell-free biomolecular "breadboards". Using free energies of the minimum free energy structures as well as melt profile computations, we estimated that a diverse set of temperature responses were possible. We experimentally found a wide range of responses to temperature in the range 29-37 °C with fold-changes varying over 3-fold around the starting thermometer. The sensitivities of these responses ranged over 10-fold around the starting thermometer. We correlated these measurements with computational expectations, finding that although there was no strong correlation for the individual thermometers, overall trends of diversity, fold-changes, and sensitivities were similar. These results present a toolbox of RNA-based circuit elements with diverse temperature responses.

An inexpensive high-temperature optical fiber thermometer

International Nuclear Information System (INIS)

Moore, Travis J.; Jones, Matthew R.; Tree, Dale R.; Allred, David D.

2017-01-01

An optical fiber thermometer consists of an optical fiber whose tip is coated with a highly conductive, opaque material. When heated, this sensing tip becomes an isothermal cavity that emits like a blackbody. This emission is used to predict the sensing tip temperature. In this work, analytical and experimental research has been conducted to further advance the development of optical fiber thermometry. An inexpensive optical fiber thermometer is developed by applying a thin coating of a high-temperature cement onto the tip of a silica optical fiber. An FTIR spectrometer is used to detect the spectral radiance exiting the fiber. A rigorous mathematical model of the irradiation incident on the detection system is developed. The optical fiber thermometer is calibrated using a blackbody radiator and inverse methods are used to predict the sensing tip temperature when exposed to various heat sources. - Highlights: • An inexpensive coating for an optical fiber thermometer sensing tip is tested. • Inverse heat transfer methods are used to estimate the sensing tip temperature. • An FTIR spectrometer is used as the detector to test the optical fiber thermometer using various heat sources.

PREFACE: Kelvin and Ireland

Science.gov (United States)

Flood, Raymond; McCartney, Mark; Whitaker, Andrew

2009-07-01

Sir Joseph Larmor unveiling the Kelvin memorial in the Botanic Gardens, Belfast on a rainy day in 1913 Sir Joseph Larmor unveiling the Kelvin memorial in the Botanic Gardens, Belfast on a rainy day in 1913 © The Ulster Museum: Hogg collection William Thomson, later Lord Kelvin, was born in Belfast in 1824, and his family had lived near Ballynahinch in the north of Ireland, quite close to Belfast, from the seventeenth century. At the time of Kelvin's birth, James Thomson, his father, was Professor of Mathematics at the Belfast Royal Academical Institution (Inst). However, following the death of his wife in 1830, James took up a new position as Professor at the University of Glasgow, and he and his children moved there in 1832. Apart from three years studying at Cambridge, and a very brief period immediately afterwards travelling and teaching in Cambridge, Kelvin was to spend the rest of his life in Glasgow, where he occupied the Chair of Natural Philosophy (or Physics) for 53 years. The natural assumption might be that his birth in Ireland was irrelevant to Kelvin's life and work, and that the fine monument erected in his honour in Belfast's Botanic Gardens, which is pictured on the front cover of this volume, was more a demonstration of civic pride than a recognition of an aspect of Kelvin's life which was important to him. The purpose of the meeting was to demon strate that this was not the case, that, great Glaswegian as he undoubtedly became, Kelvin always delighted in the title of Irishman. The influence of his father, very much an Ulsterman, was immense, and Kelvin and his siblings were to follow his non-sectarian and reforming approach. Also important for Kelvin was his Christian upbringing, which began in Belfast, and his beliefs were to play a role of importance in his life and indeed in much of his most important work, in particular that on thermodynamics. Two of his siblings returned to Belfast and spent much of their lives there, and Kelvin was a

Intraoperative body temperature control: esophageal thermometer versus infrared tympanic thermometer.

Science.gov (United States)

Poveda, Vanessa de Brito; Nascimento, Ariane de Souza

2016-01-01

To verify the correlation between temperature measurements performed using an infrared tympanic thermometer and an esophageal thermometer during the intraoperative period. A longitudinal study of repeated measures was performed including subjects aged 18 years or older undergoing elective oncologic surgery of the digestive system, with anesthesia duration of at least 1 hour. Temperature measurements were performed simultaneously by a calibrated esophageal thermometer and by a calibrated infrared tympanic thermometer, with laboratory reading precision of ±0.2ºC. The operating room temperature remained between 19 and 21ºC. The study included 51 patients, mostly men (51%), white (80.4%). All patients were kept warm by a forced-air heating system, for an average of 264.14 minutes (SD = 87.7). The two temperature measurements showed no different behavior over time (p = 0.2205), however, tympanic measurements were consistently 1.24°C lower (ptemperatura realizadas por meio de um termômetro timpânico por infravermelho e por um termômetro esofágico, durante o período intraoperatório. Realizou-se um estudo longitudinal, de medidas repetidas, incluindo sujeitos com idade igual ou superior a 18 anos, submetidos à cirurgia oncológica eletiva do sistema digestório, com duração da anestesia de, no mínimo, 1 hora. As medidas de temperatura eram realizadas, ao mesmo tempo, por meio de um termômetro esofágico calibrado e por termômetro timpânico por infravermelho calibrado, com precisão de leitura em laboratório de ±0,2ºC. A temperatura da sala operatória permaneceu entre 19 e 21ºC. Foram incluídos 51 pacientes, em sua maioria homens (51%), brancos (80,4%). Todos os pacientes foram aquecidos com o sistema de ar forçado aquecido, em média por 264,14 minutos (DP = 87,7). As duas medidas de temperatura não tiveram comportamento diferente ao longo do tempo (p = 0,2205), mas a medida timpânica foi consistentemente menor em 1,24°C (p temperaturas mais

Broadband interferometric characterisation of nano-positioning stages with sub-10 pm resolution

Science.gov (United States)

Li, Zhi; Brand, Uwe; Wolff, Helmut; Koenders, Ludger; Yacoot, Andrew; Puranto, Prabowo

2017-06-01

A traceable calibration setup for investigation of the quasi-static and the dynamic performance of nano-positioning stages is detailed, which utilizes a differential plane-mirror interferometer with double-pass configuration from the National Physical Laboratory (NPL). An NPL-developed FPGA-based interferometric data acquisition and decoding system has been used to enable traceable quasi-static calibration of nano-positioning stages with high resolution. A lockin based modulation technique is further introduced to quantitatively calibrate the dynamic response of moving stages with a bandwidth up to 100 kHz and picometer resolution. First experimental results have proven that the calibration setup can achieve under nearly open-air conditions a noise floor lower than 10 pm/sqrt(Hz). A pico-positioning stage, that is used for nanoindentation with indentation depths down to a few picometers, has been characterized with this calibration setup.

A low-temperature (4-300K) constant volume gas thermometer

International Nuclear Information System (INIS)

Combarieu, A. de

1976-01-01

A constant volume gas thermometer was built to calibrate the various secondary thermometers used at low temperature. This gas thermometer is placed in a cryostat where any stable temperature between 4 and 300K may be obtained. The principle is outlined, then the gas thermometer and its auxiliary equipment are briefly described; the corrections to be applied to the results are given and a table shows the values obtained [fr

Lord Kelvin's atmospheric electricity measurements

Science.gov (United States)

Aplin, Karen; Harrison, R. Giles; Trainer, Matthew; Hough, James

2013-04-01

Lord Kelvin (William Thomson), one of the greatest Victorian scientists, made a substantial but little-recognised contribution to geophysics through his work on atmospheric electricity. He developed sensitive instrumentation for measuring the atmospheric electric field, including invention of a portable electrometer, which made mobile measurements possible for the first time. Kelvin's measurements of the atmospheric electric field in 1859, made during development of the portable electrometer, can be used to deduce the substantial levels of particulate pollution blown over the Scottish island of Arran from the industrial mainland. Kelvin was also testing the electrometer during the largest solar flare ever recorded, the "Carrington event" in the late summer of 1859. Subsequently, Lord Kelvin also developed a water dropper sensor, and employed photographic techniques for "incessant recording" of the atmospheric electric field, which led to the long series of measurements recorded at UK observatories for the remainder of the 19th and much of the 20th century. These data sets have been valuable in both studies of historical pollution and cosmic ray effects on atmospheric processes.

Evaluation of flow-induced vibration of thermometer well for JOYO

International Nuclear Information System (INIS)

Isozaki, Kazunori; Tomita, Naoki

1997-05-01

Sodium leak accident of MONJU was caused high cycles fatigue damage of thermometer well by flow-induced vibration. It was due to the symmetric vortex shedding which was occurred rear flow of thermometer well. So, Thermometer wells installed in primary and secondary heat transport systems of JOYO were evaluated of flow-induced vibration. Evaluation of flow-induced vibration of thermometer well was done checking of flow-induced vibration base on authorized design report for JOYO, evaluation of summary flow-induced vibration by natural frequency of thermometer well in sodium as cantilever models, and evaluation based on small velocity rule of ASME Code Section III Appendix N-1300. By this result, thermometer wells (12B piping of secondary cooling system) were not satisfied requirement to avoid flow-induced vibration by small velocity rule. Therefore, Detailed vibration characteristic analysis, water flow-induced vibration test, dumping test and evaluation of structural integrity were carried out. These results, vibration amplitude of well on the tip was 0.13 mm (vibration non-dimensional amplitude of 0.015) and peak stress of 2.9 kg/mm 2 is occurred. Thermometer wells (12B piping of secondary cooling system) which occurred peak stress by flow vibration was confirmed enough to satisfy 5.3 kg/mm 2 of design fatigue limit. (author)

Measurement of body temperature by use of auricular thermometers versus rectal thermometers in dogs with otitis externa.

Science.gov (United States)

González, A Michelle; Mann, F A; Preziosi, Diane E; Meadows, Richard L; Wagner-Mann, Colette C

2002-08-01

To compare measurements of body temperature obtained with auricular thermometers versus rectal thermometers in dogs with otitis externa. Prospective study. 100 client-owned dogs: 50 with and 50 without clinical evidence of otitis externa. Dogs were evaluated for the presence of otitis externa on the basis of clinical signs, otoscopic examination, and cytologic evaluation of ear exudate. Auricular and rectal temperatures were obtained simultaneously in all dogs prior to and following ear examination. There was a high correlation between auricular and rectal temperatures in dogs with otitis externa both prior to and after ear manipulation. Significant differences were not detected in temperature measurements among dogs with different degrees of otitis externa. Auricular temperature readings obtained by use of an auricular thermometer in dogs with otitis externa are accurate measurements of body temperature, compared with rectal temperature measurements. Temperature measurements are reliable before and after examination of the ear canal.

Measuring Systems for Thermometer Calibration in Low-Temperature Range

Science.gov (United States)

Szmyrka-Grzebyk, A.; Lipiński, L.; Manuszkiewicz, H.; Kowal, A.; Grykałowska, A.; Jancewicz, D.

2011-12-01

The national temperature standard for the low-temperature range between 13.8033 K and 273.16 K has been established in Poland at the Institute of Low Temperature and Structure Research (INTiBS). The standard consists of sealed cells for realization of six fixed points of the International Temperature Scale of 1990 (ITS-90) in the low-temperature range, an adiabatic cryostat and Isotech water and mercury triple-point baths, capsule standard resistance thermometers (CSPRT), and AC and DC bridges with standard resistors for thermometers resistance measurements. INTiBS calibrates CSPRTs at the low-temperature fixed points with uncertainties less than 1 mK. In lower temperature range—between 2.5 K and about 25 K — rhodium-iron (RhFe) resistance thermometers are calibrated by comparison with a standard which participated in the EURAMET.T-K1.1 comparison. INTiBS offers a calibration service for industrial platinum resistance thermometers and for digital thermometers between 77 K and 273 K. These types of thermometers may be calibrated at INTiBS also in a higher temperature range up to 550°C. The Laboratory of Temperature Standard at INTiBS acquired an accreditation from the Polish Centre for Accreditation. A management system according to EN ISO/IEC 17025:2005 was established at the Laboratory and presented on EURAMET QSM Forum.

Performance of Magnetic Penetration Thermometers for X-Ray Astronomy

Science.gov (United States)

Nagler, P. C.; Adams, J. S.; Balvin, M. A.; Bandler, S. R.; Denis, K. L.; Hsieh, W. T.; Kelly, D. P.; Porst, J. P.; Sadleir, J. E.; Seidel, G. M.;

Kelvin, thermodynamics and the natural world

CERN Document Server

Collins, MW; Koenig, C; Dougal, R C; Koenig, C; Ruddock, I

2015-01-01

This volume looks afresh at the life and works of Lord Kelvin including his standing and relationships with Charles Darwin, T. S Huxley and the X-club, thereby throwing new light on the nineteenth-century conflict between the British energy and biology specialists. Useful to scientists and engineers interested in thermodynamics and Lord Kelvin.

A calorimetric particle detector using an iridium superconducting phase transition thermometer

International Nuclear Information System (INIS)

Frank, M.; Dummer, D.; Cooper, S.; Igalson, J.; Proebst, F.; Seidel, W.

1994-01-01

We report on a calorimetric particles detector consisting of an 18.3 g silicon crystal and an iridium superconducting phase transition thermometer. The cryogenic calorimeter and the associated apparatus are described in detail. The pulses from irradiation with an α-particle source have a large unexpected overshoot in addition to the component expected from a naive thermal model. The pulse height spectrum displays an energy resolution of 1 percent FWHM at 6 MeV and good linearity. The noise, electrothermal feedback, and position dependence are discussed. (orig.)

Kelvin-Helmholtz instability in solar spicules

Directory of Open Access Journals (Sweden)

H Ebadi

2016-12-01

Full Text Available Magneto hydrodynamic waves, propagating along spicules, may become unstable and the expected instability is of Kelvin-Helmholtz type. Such instability can trigger the onset of wave turbulence leading to an effective plasma heating and particle acceleration. In present study, two-dimensional magneto hydrodynamic simulations performed on a Cartesian grid is presented in spicules with different densities, moving at various speeds depending on their environment. Simulations being applied in this study show the onset of Kelvin-Helmholtz type instability and transition to turbulent flow in spicules. Development of Kelvin-Helmholtz instability leads to momentum and energy transport, dissipation, and mixing of fluids. When magnetic fields are involved, field amplification is also possible to take place

Controlling mercury spills in laboratories with a thermometer exchange program

Energy Technology Data Exchange (ETDEWEB)

McLouth, Lawrence D.

2002-03-25

This paper presents a case for replacing mercury thermometers with their organic-liquid-filled counterparts. A review of liquid-in glass-thermometers is given. In addition, a brief summary of mercury's health effects and exposure limits is presented. Spill cleanup methods and some lessons learned from our experience are offered as well. Finally, an overview of the mercury thermometer exchange program developed at Lawrence Berkeley National Laboratory is presented.

Semiconductor resistance thermometer for the temperature range 300-0.3 K

International Nuclear Information System (INIS)

Zinov'eva, K.N.; Zarubin, L.I.; Nemish, I.Yu.; Vorobkalo, F.M.; Boldarev, S.T.; AN Ukrainskoj SSR, Kiev. Inst. Poluprovodnikov)

1979-01-01

Thermometric characteristics of semiconductor resistor thermometers for the temperature range from 300 to 0.3 K and from 77 to 0.3 K are given. Temperature dependence of thermometer resistances in the 300-1.3 K range was measured in cryostats with pumping-out of N 2 , H 2 and 4 He. For measurements below 1.3 K use was made of a 3 H- 4 He dissolving cryostat. The accuracy of measuring temperatures in the 1.3-0.3 K range is not below +-0.003 K, the error in determining thermometer resistances does not exceed 1%. The analysis of obtained thermometric characteristics of several series of semiconductor resistance thermometers showed that observed insignificant spread of resistances of thermometers in one series and identity of characteristics allows them to be used without preliminary calibration for relatively coarse measurements in the range from 3O0 to 0.3 K. Besides, it has been found that in the 4.2-0.3 K range the thermometric characteristics represent a straight line in the lgR-Tsup(-n) coordinates, where R is the thermometer resistance, T is the temperature and n=0.5. Thus, the thermometers of the same series can be calibrated only in 2 or 3 reference point measurements

Galileo Chain Thermometer

Science.gov (United States)

Ucke, C.; Schlichting, H. J.

2017-01-01

This relatively rare thermometer has a rather unusual display: lower temperatures are located at the top of the scale, higher ones at the bottom. A sphere on a chain floats in a suitable liquid, sinking at high temperatures when the density of the liquid decreases and rising in the increased density at low temperatures. With reasonable effort and…

Silicon photonic thermometer operating on multiple polarizations

DEFF Research Database (Denmark)

Guan, Xiaowei; Wang, Xiaoyan; Frandsen, Lars Hagedorn

2016-01-01

A silicon photonics optical thermometer simultaneously operating on the multiple polarizations is designed and experimentally demonstrated. Measured sensitivities are 86pm/°C and 48pm/°C for the transverse-electric and transverse-magnetic polarizations, respectively.......A silicon photonics optical thermometer simultaneously operating on the multiple polarizations is designed and experimentally demonstrated. Measured sensitivities are 86pm/°C and 48pm/°C for the transverse-electric and transverse-magnetic polarizations, respectively....

Kelvin Wave Influence on the Shallow-to-Deep Transition Over the Amazon

Science.gov (United States)

Rowe, A.; Serra, Y. L.

2017-12-01

over the Central Amazon in both global and regional model simulations with differing resolution and choice of convective parameterization. This work will test the hypothesis that when the environment is strongly modified by a Kelvin wave, model shallow-to-deep transition will be better simulated than when this forcing is not present.

The constitution of the heat density of a gamma thermometer

International Nuclear Information System (INIS)

Hantouche, C.

1984-01-01

This paper's aim is to present the nuclear transfer function of the signal of the γ thermometer used in a PWR reactor. The nuclear transfer function between the linear nuclear power and the γ thermometer heat density has been established. The corresponding computation code has been built up. The results concerning the environment behaviour of the γ thermometer, the heat density axial and radial repartitions, the control rods and the grids' influences are presented and discussed. (orig.)

Adiabatic surface thermometer for improved production braze quality

International Nuclear Information System (INIS)

Dittbenner, G.R.

1975-01-01

An adiabatic surface thermometer was developed to control automatically the critical temperature-time cycle of a production vacuum-brazing process. Investigations revealed that optimum braze-joint strength required precise control of the brazing temperature. Spot-welded thermocouples could not be used because the spot welds cause surface damage. This thermometer touches the surface and uses a differential thermocouple and heater to measure surface temperature without heat flow, thereby eliminating large errors caused by conduction losses common to conventional spring-loaded thermocouples. Temperatures in air or vacuum are measured to 800 0 C with errors less than 5 0 C. This thermometer has minimized the rejection of production parts, resulting in a cost saving to the U. S. Energy Research and Development Administration

Investigation of the integrated effects of irradiating platinum resistance thermometers

International Nuclear Information System (INIS)

Neverov, V.A.; Revyakin, Yu.L.

1993-01-01

The development of nuclear energy imposes increased demands on the reliability and quality of the information obtained from primary transducers which monitor the basic parameters of current reactor devices. One of these parameters is the temperature of different modules. This is mainly measured by thermoelectric transducers. Resistance thermometers now being adopted into measurement practice. These provide an initial accuracy of better than plus or minus 273 degrees C and also a normalized systematic error component caused by the action of the temperature. However, a systematic error component resulting from the action of the reactor radiation remains undetermined, and this greatly hinders the extensive use of resistance thermometers in reactor devices. Investigations were made using platinum resistance thermometers of different constructions designs. Irradiation took place in sealed ampules. Each of these contained three thermometers. The fluence achieved was varied by placing the ampules at different heights relative to the central plane of the active zone of the reactor. The irradiation temperature was determined by calculation, taking into account the radiative energy release where the irradiation occurred and the helium gap between the thermometer casing and the walls of an SM-2 reactor channel. Following irradiation in the reactor, the resistance thermometers were calibrated in a special thermometric device providing the minimum contact resistance, uniform heating of the samples, and stabilization of the temperature regime

A Non-Mercury Thermometer Alternative for Use in Older Melting Point Apparatuses

Science.gov (United States)

Ongley, Lois K.; Kern, Clayton S.; Woods, Barry W.

2008-01-01

The State of Maine seeks to eliminate most mercury use. This includes removing mercury thermometers from secondary schools and discouraging Hg use in other educational institutions. Alternatives to mercury thermometers in chemical laboratory work include non-mercury thermometers, temperature probes, and thermocouples. In organic chemistry mercury…

A sub-Kelvin cryogen-free EPR system.

Science.gov (United States)

Melhuish, Simon J; Stott, Chloe; Ariciu, Ana-Maria; Martinis, Lorenzo; McCulloch, Mark; Piccirillo, Lucio; Collison, David; Tuna, Floriana; Winpenny, Richard

2017-09-01

We present an EPR instrument built for operation at Q band below 1K. Our cryogen-free Dewar integrates with a commercial electro-magnet and bridge. A description of the cryogenic and RF systems is given, along with the adaptations to the standard EPR experiment for operation at sub-Kelvin temperatures. As a first experiment, the EPR spectra of powdered Cr 12 O 9 (OH) 3 [Formula: see text] were measured. The sub-Kelvin EPR spectra agree well with predictions, and the performance of the sub-Kelvin system at 5K is compared to that of a commercial spectrometer. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Infrared Thermometer: an accurate tool for temperature measurement during renal surgery

Directory of Open Access Journals (Sweden)

Giovanni Scala Marchini

2013-07-01

Full Text Available Purpose To evaluate infrared thermometer (IRT accuracy compared to standard digital thermometer in measuring kidney temperature during arterial clamping with and without renal cooling. Materials and Methods 20 pigs weighting 20Kg underwent selective right renal arterial clamping, 10 with (Group 1 - Cold Ischemia with ice slush and 10 without renal cooling (Group 2 - Warm Ischemia. Arterial clamping was performed without venous clamping. Renal temperature was serially measured following clamping of the main renal artery with the IRT and a digital contact thermometer (DT: immediate after clamping (T0, after 2 (T2, 5 (T5 and 10 minutes (T10. Temperature values were expressed in mean, standard deviation and range for each thermometer. We used the T student test to compare means and considered p < 0.05 to be statistically significant. Results In Group 1, mean DT surface temperature decrease was 12.6 ± 4.1°C (5-19°C while deep DT temperature decrease was 15.8 ± 1.5°C (15-18°C. For the IRT, mean temperature decrease was 9.1 ± 3.8°C (3-14°C. There was no statistically significant difference between thermometers. In Group 2, surface temperature decrease for DT was 2.7 ± 1.8°C (0-4°C and mean deep temperature decrease was 0.5 ± 1.0°C (0-3°C. For IRT, mean temperature decrease was 3.1 ± 1.9°C (0-6°C. No statistically significant difference between thermometers was found at any time point. conclusions IRT proved to be an accurate non-invasive precise device for renal temperature monitoring during kidney surgery. External ice slush cooling confirmed to be fast and effective at cooling the pig model. IRT = Infrared thermometer DT = Digital contact thermometer D:S = Distance-to-spot ratio

Ion thermometers in reactor technology

International Nuclear Information System (INIS)

Yakesh, D.; Kott, J.; Strnad, M.

1980-01-01

The width of the temperature discontinuity and the thermometric stability of the sensors are constant up to very high flux values. The immediate influence of irradiation is reduced to a decrease in the hysteresis of the conduction curve at the phase transition. When the readings of the ion thermometers are compared with the reading of Chromel-Alumel thermocouples, it is observed that the temperature difference amounts to approximately 7/degree/C in the case of thermocouples placed at the sensor socket; the temperature difference decreases to 2/degree/C in the case of the thermocouple junction situated between the electrodes. The good results obtained in the testing of the ion thermometers in nuclear reactors lead to the conclusion that these temperature sensors are promising for checking thermocouples in the core of nuclear power stations

Characteristics of infrared thermometers manufactured in Japan and calibration methods for sky radiant emittance

International Nuclear Information System (INIS)

Wang, X.; Horiguchi, I.; Machimura, T.

1993-01-01

Infrared thermometers to measure surface temperature have been increasingly adopted in recent years. The characteristics of the IR thermometer, however, are not well known.IR thermometers manufactured in Japan systematically adjust for ambient radiation based on the internal temperature of the thermometer. If, therefore, there is a large difference between the internal temperature of the IR thermometer and the apparent temperature associated with the surrounding radiation, a large error will be induced into the measured surface temperature.The purpose of our research was to determine the characteristics and measurement errors of IR thermometers. Experiments were performed with regard to the following items: (1) Measurement errors related to the internal temperature of the IR thermometer. (2) Linearity of the output signal of the IR thermometer. (3) Response of the output signal to changes in the emissivity setting. (4) Effect of sky radiant emittance on the measured surface temperature. (5) Calibration method for the terrestrial surface.The following is a summary of the results: Measurement error is affected by the internal temperature of the IR thermometer. Measurement accuracy is improved with a controlled internal temperature of 20-30°C. The measurement error becomes larger at emissivity settings under 0.7.The measurement error outdoors was not proportional to the downward longwave radiation, but to the sky radiant temperature measured by the IR thermometer. Calibration for sky radiant emittance was improved by using the difference between sky radiant temperature and air temperature.When the surface temperature measured by the infrared thermometer is plotted against the surface temperature measured by thermocouple, the sky radiant emittance error is obtained from the Y intercept. Additionally, the difference between true temperature and output of the IR thermometer for a reference plate was compared to that obtained for vegetation, and the RMS obtained was

The Fast Alternative Cryogenic Experiment Testbed

Science.gov (United States)

Nash, Alfred; Holmes, Warren

2000-01-01

One of the challenges in the area of cryogenics for space exploration in the next millennium is providing the capability for inexpensive, frequent, access to space. Faced with this challenge during the International Space Station (ISS) build era, when other Space Shuttle manifesting opportunities are unavailable, a "proof of concept" cryostat has been developed to demonstrate the ability to accommodate low temperature science investigations within the constraints of the Hitchhiker siderail carrier. The Hitchhiker siderail carrier is available on a "mass available" basis during the ISS build era. In fact, several hitchhiker payloads flew with the deployment of the Unity module. Hitchhiker siderail carrier payloads have historically flown an average of about four times a year. A hybrid Solid Neon - Superfluid Helium cryostat has been developed with Janis Research Company to accommodate instruments of 16.5 cm diameter and 30 cm. length. This hybrid approach was taken in part to provide adequate on-orbit lifetime for instruments with high (conducted) heat loads from the instrumentation wiring. Mass, volume, lifetime and the launch hold scenario were all design drivers. In addition, with Ball Aerospace and Technologies Corporation, a multichannel VME architecture Germanium Resistance Thermometer (GRT) readout and heater control servo system has been developed. In a flight system, the cryostat and electronics payloads would be umbilically attached in a paired Hitchhiker siderail mount, and permit on-orbit command and telemetry capability. The results of performance tests of both the cryostat, and a helium sample instrument will be presented. The instrument features a self contained, miniaturized, nano-Kelvin resolution High Resolution Thermometer (HRT). This high level of thermal resolution is achieved through the utilization of a dc Superconducting Quantum Interference Device (SQUID). Although developed for the Low Temperature Microgravity Fundamental Physics

Stability of High Temperature Standard Platinum Resistance Thermometers at High Temperatures

Directory of Open Access Journals (Sweden)

Y. A. ABDELAZIZ

2010-05-01

Full Text Available An investigation of the stability of high temperature standard platinum resistance thermometers HTSPRTs has been carried out for two different designs thermometers (with nominal resistance 0.25 Ω and 2.5 Ω from two different suppliers. The thermometers were heated for more than 160 hours at temperatures above 960 0C using a vertical furnace with a ceramic block. A study was made of the influence of the heat treatment on the stability of the resistance at the triple point of water, and on the relative resistance W(Ga at the melting point of gallium. The thermometers showed a correlation between the drift note and the values of W(Ga. It was found also that the HTSPRT which has a sensor with strip shaped support and low nominal resistance is more stable than the HTSPRT which has a sensor in the form of a coil wound on silica cross. The 0.25 Ω thermometer has better stability @ 7x10-6 0C (at TPW after 40 hour. Factors affecting the stability and accuracy of HTSPRT also will be discussed.

A compact sub-Kelvin ultrahigh vacuum scanning tunneling microscope with high energy resolution and high stability.

Science.gov (United States)

Zhang, L; Miyamachi, T; Tomanić, T; Dehm, R; Wulfhekel, W

2011-10-01

We designed a scanning tunneling microscope working at sub-Kelvin temperatures in ultrahigh vacuum (UHV) in order to study the magnetic properties on the nanoscale. An entirely homebuilt three-stage cryostat is used to cool down the microscope head. The first stage is cooled with liquid nitrogen, the second stage with liquid (4)He. The third stage uses a closed-cycle Joule-Thomson refrigerator of a cooling power of 1 mW. A base temperature of 930 mK at the microscope head was achieved using expansion of (4)He, which can be reduced to ≈400 mK when using (3)He. The cryostat has a low liquid helium consumption of only 38 ml/h and standing times of up to 280 h. The fast cooling down of the samples (3 h) guarantees high sample throughput. Test experiments with a superconducting tip show a high energy resolution of 0.3 meV when performing scanning tunneling spectroscopy. The vertical stability of the tunnel junction is well below 1 pm (peak to peak) and the electric noise floor of tunneling current is about 6fA/√Hz. Atomic resolution with a tunneling current of 1 pA and 1 mV was achieved on Au(111). The lateral drift of the microscope at stable temperature is below 20 pm/h. A superconducting spilt-coil magnet allows to apply an out-of-plane magnetic field of up to 3 T at the sample surface. The flux vortices of a Nb(110) sample were clearly resolved in a map of differential conductance at 1.1 K and a magnetic field of 0.21 T. The setup is designed for in situ preparation of tip and samples under UHV condition.

Magnetohydrodynamic Kelvin-Helmholtz instability; Magnetohydrodynamische Kelvin-Helmholtz-Instabilitaet

Energy Technology Data Exchange (ETDEWEB)

Brett, Walter

2014-07-21

In the presented work the Kelvin-Helmholtz-Instability in magnetohydrodynamic flows is analyzed with the methods of Multiple Scales. The concerned fluids are incompressible or have a varying density perpendicular to the vortex sheet, which is taken into account using a Boussinesq-Approximation and constant Brunt-Vaeisaelae-Frequencies. The Multiple Scale Analysis leads to nonlinear evolution equations for the amplitude of the perturbations. Special solutions to these equations are presented and the effects of the magnetic fields are discussed.

The Kelvin and Temperature Measurements

Science.gov (United States)

Mangum, B. W.; Furukawa, G. T.; Kreider, K. G.; Meyer, C. W.; Ripple, D. C.; Strouse, G. F.; Tew, W. L.; Moldover, M. R.; Johnson, B. Carol; Yoon, H. W.; Gibson, C. E.; Saunders, R. D.

2001-01-01

The International Temperature Scale of 1990 (ITS-90) is defined from 0.65 K upwards to the highest temperature measurable by spectral radiation thermometry, the radiation thermometry being based on the Planck radiation law. When it was developed, the ITS-90 represented thermodynamic temperatures as closely as possible. Part I of this paper describes the realization of contact thermometry up to 1234.93 K, the temperature range in which the ITS-90 is defined in terms of calibration of thermometers at 15 fixed points and vapor pressure/temperature relations which are phase equilibrium states of pure substances. The realization is accomplished by using fixed-point devices, containing samples of the highest available purity, and suitable temperature-controlled environments. All components are constructed to achieve the defining equilibrium states of the samples for the calibration of thermometers. The high quality of the temperature realization and measurements is well documented. Various research efforts are described, including research to improve the uncertainty in thermodynamic temperatures by measuring the velocity of sound in gas up to 800 K, research in applying noise thermometry techniques, and research on thermocouples. Thermometer calibration services and high-purity samples and devices suitable for “on-site” thermometer calibration that are available to the thermometry community are described. Part II of the paper describes the realization of temperature above 1234.93 K for which the ITS-90 is defined in terms of the calibration of spectroradiometers using reference blackbody sources that are at the temperature of the equilibrium liquid-solid phase transition of pure silver, gold, or copper. The realization of temperature from absolute spectral or total radiometry over the temperature range from about 60 K to 3000 K is also described. The dissemination of the temperature scale using radiation thermometry from NIST to the customer is achieved by

27 CFR 30.23 - Use of precision hydrometers and thermometers.

Science.gov (United States)

2010-04-01

... hydrometers and thermometers. 30.23 Section 30.23 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO... Use of precision hydrometers and thermometers. Care should be exercised to obtain accurate hydrometer... entire quantity. The hydrometers should be kept clean and free of any oily substance. Immediately before...

Electrowetting Using a Microfluidic Kelvin Water Dropper

Directory of Open Access Journals (Sweden)

Elias Yazdanshenas

2018-02-01

Full Text Available The Kelvin water dropper is an electrostatic generator that can generate high voltage electricity through water dripping. A conventional Kelvin water dropper converts the gravitational potential energy of water into electricity. Due to its low current output, Kelvin water droppers can only be used in limited cases that demand high voltage. In the present study, microfluidic Kelvin water droppers (MKWDs were built in house to demonstrate a low-cost but accurately controlled miniature device for high voltage generation. The performance of the MKWDs was characterized using different channel diameters and flow rates. The best performed MKWD was then used to conduct experiments of the electrowetting of liquid on dielectric surfaces. Electrowetting is a process that has been widely used in manipulating the wetting properties of a surface using an external electric field. Usually electrowetting requires an expensive DC power supply that outputs high voltage. However, in this research, it was demonstrated that electrowetting can be conducted by simply using an MKWD. Additionally, an analytic model was developed to simulate the electrowetting process. Finally, the model’s ability to well predict the liquid deformation during electrowetting using MKWDs was validated.

The influence of surface topography on Kelvin probe force microscopy

International Nuclear Information System (INIS)

Sadewasser, S; Leendertz, C; Streicher, F; Lux-Steiner, M Ch

2009-01-01

Long-range electrostatic forces govern the imaging mechanism in electrostatic force microscopy as well as in Kelvin probe force microscopy. To improve the analysis of such images, simulations of the electrostatic field distribution have been performed in the past using a flat surface and a cone-shaped tip. However, the electrostatic field distribution between a tip and a sample depends strongly on the surface topography, which has been neglected in previous studies. It is therefore of general importance to study the influence of sample topography features on Kelvin probe force microscopy images, which we address here by performing finite element simulations. We show how the surface potential measurement is influenced by surface steps and surface grooves, considering potential variations in the form of a potential peak and a potential step. The influence of the topography on the measurement of the surface potential is found to be rather small compared to a typical experimental resolution. Surprisingly, in the case of a coinciding topography and potential step an improvement of the potential profile due to the inclusion of the topography is observed. Finally, based on the obtained results, suggestions for the realization of KPFM measurement are given.

Stability of High Temperature Standard Platinum Resistance Thermometers at High Temperatures

OpenAIRE

Y. A. ABDELAZIZ; F. M. MEGAHED

2010-01-01

An investigation of the stability of high temperature standard platinum resistance thermometers HTSPRTs has been carried out for two different designs thermometers (with nominal resistance 0.25 Ω and 2.5 Ω) from two different suppliers. The thermometers were heated for more than 160 hours at temperatures above 960 0C using a vertical furnace with a ceramic block. A study was made of the influence of the heat treatment on the stability of the resistance at the triple point of water, and on the...

High speed infrared radiation thermometer, system, and method

Science.gov (United States)

Markham, James R.

2002-01-01

The high-speed radiation thermometer has an infrared measurement wavelength band that is matched to the infrared wavelength band of near-blackbody emittance of ceramic components and ceramic thermal barrier coatings used in turbine engines. It is comprised of a long wavelength infrared detector, a signal amplifier, an analog-to-digital converter, an optical system to collect radiation from the target, an optical filter, and an integral reference signal to maintain a calibrated response. A megahertz range electronic data acquisition system is connected to the radiation detector to operate on raw data obtained. Because the thermometer operates optimally at 8 to 12 .mu.m, where emittance is near-blackbody for ceramics, interferences to measurements performed in turbine engines are minimized. The method and apparatus are optimized to enable mapping of surface temperatures on fast moving ceramic elements, and the thermometer can provide microsecond response, with inherent self-diagnostic and calibration-correction features.

The gamma thermometer as a measuring instrument of the nuclear power of a LWR core

International Nuclear Information System (INIS)

Hantouche, C.

1984-07-01

After a presentation of the gamma thermometer and its environment, this thesis deals with the calibration of a gamma thermometer or determination of the thermal transfer ratio of the signal. Then, the acquisition systems for signals obtained from gamma thermometers installed in PWR nuclear power plants are presented. One deals also with the nuclear transfer function establishment and deconvolution. Then, one deals with the reconstruction of the axial power of an assembly provided with a gamma thermometer. Qualitative and quantitative studies of measurements obtained from this gamma thermometer are finally presented. 64 refs [fr

Gas selectivity of SILAR grown CdS nano-bulk junction

Science.gov (United States)

Jayakrishnan, R.; Nair, Varun G.; Anand, Akhil M.; Venugopal, Meera

2018-03-01

Nano-particles of cadmium sulphide were deposited on cleaned copper substrate by an automated sequential ionic layer adsorption reaction (SILAR) system. The grown nano-bulk junction exhibits Schottky diode behavior. The response of the nano-bulk junction was investigated under oxygen and hydrogen atmospheric conditions. The gas response ratio was found to be 198% for Oxygen and 34% for Hydrogen at room temperature. An increase in the operating temperature of the nano-bulk junction resulted in a decrease in their gas response ratio. A logarithmic dependence on the oxygen partial pressure to the junction response was observed, indicating a Temkin isothermal behavior. Work function measurements using a Kelvin probe demonstrate that the exposure to an oxygen atmosphere fails to effectively separate the charges due to the built-in electric field at the interface. Based on the benefits like simple structure, ease of fabrication and response ratio the studied device is a promising candidate for gas detection applications.

Kelvin and industry in Ireland

Science.gov (United States)

Crossland, Bernard; Whitaker, Andrew

2009-04-01

Kelvin was a great mathematician, theoretical and experimental physicist, and educator, founding the first physical laboratory. He worked tirelessly for the creation of a reproducible set of physical units, and he was also an experienced and enthusiastic sailor. All these talents were linked to his extensive technological work, of which the most important examples were the laying of the Atlantic cable, and the marine compass. In Ireland his most important contributions were the occulting nature of the Holywood lighthouse, and his connection with the Giant's Causeway tramway. Kelvin's work on cabling and national maritime projects may have stimulated his later strong support of the British Empire and opposition to Home Rule in Ireland.

Kelvin and industry in Ireland

Energy Technology Data Exchange (ETDEWEB)

Crossland, Bernard [Department of Mechanical Engineering, Queen' s University, Belfast BT7 1NN, Northern Ireland (United Kingdom); Whitaker, Andrew, E-mail: b.crossland@qub.ac.u, E-mail: a.whitaker@qub.ac.u [Department of Physics, Queen' s University, Belfast BT7 1NN, Northern Ireland (United Kingdom)

2009-04-01

Kelvin was a great mathematician, theoretical and experimental physicist, and educator, founding the first physical laboratory. He worked tirelessly for the creation of a reproducible set of physical units, and he was also an experienced and enthusiastic sailor. All these talents were linked to his extensive technological work, of which the most important examples were the laying of the Atlantic cable, and the marine compass. In Ireland his most important contributions were the occulting nature of the Holywood lighthouse, and his connection with the Giant's Causeway tramway. Kelvin's work on cabling and national maritime projects may have stimulated his later strong support of the British Empire and opposition to Home Rule in Ireland.

Kelvin and industry in Ireland

International Nuclear Information System (INIS)

Crossland, Bernard; Whitaker, Andrew

2009-01-01

Kelvin was a great mathematician, theoretical and experimental physicist, and educator, founding the first physical laboratory. He worked tirelessly for the creation of a reproducible set of physical units, and he was also an experienced and enthusiastic sailor. All these talents were linked to his extensive technological work, of which the most important examples were the laying of the Atlantic cable, and the marine compass. In Ireland his most important contributions were the occulting nature of the Holywood lighthouse, and his connection with the Giant's Causeway tramway. Kelvin's work on cabling and national maritime projects may have stimulated his later strong support of the British Empire and opposition to Home Rule in Ireland.

Thermo-Chromium: A Contactless Optical Molecular Thermometer.

Science.gov (United States)

Otto, Sven; Scholz, Norman; Behnke, Thomas; Resch-Genger, Ute; Heinze, Katja

2017-09-07

The unparalleled excited-state potential-energy landscape of the chromium(III)-based dye [1] 3+ ([Cr(ddpd) 2 ] 3+ ; ddpd=N,N'-dimethyl-N,N'-dipyridin-2-yl-pyridin-2,6-diamine) enables a strong dual emission in the near infrared region. The temperature dependence of this dual emission allows the use of [1] 3+ as an unprecedented molecular ratiometric thermometer in the 210-373 K temperature range in organic and in aqueous media. Incorporation of [1] 3+ in biocompatible nanocarriers, such as 100 nm-sized polystyrene nanoparticles and solutol micelles, provides nanodimensional thermometers operating under physiological conditions. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Thermal Conductivity and Liquid Crystal Thermometers.

Science.gov (United States)

Edge, R. D., Ed.

1993-01-01

Describes using stock liquid crystal postcards as inexpensive classroom thermometers. Also suggests using these postcards as a good visual temperature indicator for classroom demonstrations such as temperature gradients. One such activity is provided. (MVL)

Reliability of an infrared forehead skin thermometer for core temperature measurements

NARCIS (Netherlands)

Kistemaker, J.A.; Hartog, E.A. den; Daanen, H.A.M.

2006-01-01

The SensorTouch thermometer performs an infrared measurement of the skin temperature above the Superficial Temporal Artery (STA). This study evaluates the validity and the accuracy of the SensorTouch thermometer. Two experiments were performed in which the body temperature was measured with a rectal

High-Temperature Compatible Nickel Silicide Thermometer And Heater For Catalytic Chemical Microreactors

DEFF Research Database (Denmark)

Jensen, Søren; Quaade, U.J.; Hansen, Ole

2005-01-01

Integration of heaters and thermometers is important for agile and accurate control and measurement of the thermal reaction conditions in microfabricated chemical reactors (microreactors). This paper describes development and operation of nickel silicide heaters and temperature sensors...... for temperatures exceeding 700 °C. The heaters and thermometers are integrated with chemical microreactors for heterogeneous catalytic conversion of gasses, and thermally activated catalytic conversion of CO to CO2 in the reactors is demonstrated. The heaters and thermometers are shown to be compatible...

The Infrared Thermometer in School Science: Teaching Physics with Modern Technologies

Science.gov (United States)

Girwidz, Raimund; Ireson, Gren

2011-01-01

Infrared thermometers measure temperature from a distance, using the infrared radiation emitted by all objects. These so-called non-contact thermometers make a wide variety of temperature measurement and monitoring activities accessible to school-age students. Portable hand-held sensors also enable new or simplified investigations to be carried…

[Comparison of body temperatures in children measured using 3 different thermometers: tympanic, skin and digital axillary].

Science.gov (United States)

Padilla-Raygoza, Nicolás; Ruiz-Paloalto, M Laura; Díaz-Guerrero, Rosalina; Olvera-Villanueva, Georgina; Maldonado, Angélica; Raygoza-Mendoza, María Del Pilar

2014-01-01

To compare body temperature measurements using tympanic, skin and digital axillary thermometers. Hospitalized or outpatient children from the General Hospital Celaya, ISSSTE Hospital Clinic and General Hospital No. 4 IMSS, and the pediatric private service in Celaya, Guanajuato, from 1 day of life until 16 years old, were recruited over a one month period, after their parents signed the consent form. The order of each institution was selected by simple randomization. Body temperatures were measured in triplicate using tympanic, skin and digital axillary thermometers. The sample consisted of 554 children. The Pearson r between the tympanic and digital axillary thermometers was 0.57 to 0.65, with a positive linear relationship (P<.05); between the skin and the digital axillary thermometers, it was between 0.47 and 0.52 with a positive linearrelationship (P<.05). The intra-observer Kappa for the tympanic thermometer was 0.86, and for the inter-observer was 0.77; for the skin thermometer it was 0.82 and 0.67, respectively, and for the digital axillary thermometer it was 0.86 for intra-observer reliability and 0.78 for inter -observer reliability. Tympanic and axillary thermometers showed better precision in measuring the body temperature in children than skin thermometers. Copyright © 2013 Elsevier España, S.L. All rights reserved.

Ultrafast Paper Thermometers Based on a Green Sensing Ink.

Science.gov (United States)

Tao, Xinglei; Jia, Hanyu; He, Yonglin; Liao, Shenglong; Wang, Yapei

2017-03-24

With the use of an ionic liquid as the ultrathermosensitive fluid, a paper thermometer is successfully developed with intrinsic ability of ultrafast response and high stability upon temperature change. The fluidic nature allows the ionic liquid to be easily deposited on paper by pen writing or inkjet printing, affording great promise for large-scale fabrication of low-cost paper sensors. Owing to the advantages of nonvolatilization, excellent continuity and deformability, the thermosensitive ink trapped within the cellulose fibers of paper matrix has no leakage or evaporation at open states, ensuring the excellent stability and repeatability of thermal sensing against arbitrary bending and folding operation. By shortening the heat exchange distance between ionic liquid and samples, it takes only 8 s for the thermometer to reach an electrical equilibrium at a given temperature. Moreover, the paper thermometer can be applied to remotely monitor temperature change with the combination of a wireless communication technology.

The Occurrence of Tidal Hybrid Kelvin-Edge Waves in the Global Ocean

Science.gov (United States)

Kaur, H.; Buijsman, M. C.; Yankovsky, A. E.; Zhang, T.; Jeon, C. H.

2017-12-01

This study presents the analysis of hybrid Kelvin-edge waves on the continental shelves in a global ocean model. Our objective is to find areas where the transition occurs from Kelvin waves to hybrid Kelvin-edge waves. The change in continental shelf width may convert a Kelvin wave into a hybrid Kelvin-edge wave. In this process the group velocity reaches a minimum and tidal energy is radiated on and/or offshore [Zhang 2016]. We extract M2 SSH (Sea Surface Height) and velocity from the Hybrid Coordinate Ocean Model (HYCOM) and calculate barotropic energy fluxes. We analyze these three areas: the Bay of Biscay, the Amazon Shelf and North West Africa. In these three regions, the continental shelf widens in the propagation direction and the alongshore flux changes its direction towards the coast. A transect is taken at different points in these areas to compute the dispersion relations of the waves on the continental shelf. In model simulations, we change the bathymetry of the Bay of Biscay to study the behavior of the hybrid Kelvin-edge waves. BibliographyZhang, T., and A. E Yankovsky. (2016), On the nature of cross-isobath energy fluxes in topographically modified barotropic semidiurnal Kelvin waves, J. Geophys. Res. Oceans, 121, 3058-3074, doi:10.1002/2015JC011617.

Accuracy of the Danish version of the 'distress thermometer'

DEFF Research Database (Denmark)

Bidstrup, Pernille Envold; Mertz, Birgitte Goldschmidt; Dalton, Susanne Oksbjerg

2012-01-01

Objective: Short screening instruments have been suggested to improve the detection of psychological symptoms. We examined the accuracy of the Danish version of the 'Distress Thermometer'. Methods: Between October 2008 and October 2009, 426 women with newly diagnosed primary breast cancer who were...... operated at the Breast Surgery Clinic of the Rigshospitalet, Copenhagen, were eligible for this study. Of these, 357 participated (84%) and 333 completed a questionnaire. The distress thermometer was evaluated against the 'hospital anxiety and depression scale' (HADS). We also examined the women's wish...

Ultrasound estimation and FE analysis of elastic modulus of Kelvin foam

International Nuclear Information System (INIS)

Kim, Nohyu; Yang, Seung Yong

2016-01-01

The elastic modulus of a 3D-printed Kelvin foam plate is investigated by measuring the acoustic wave velocity of 1 MHz ultrasound. An isotropic tetrakaidecahedron foam with 3 mm unit cell is designed and printed layer upon layer to fabricate a Kelvin foam plate of 14 mm thickness with a 3D CAD/printer using ABS plastic. The Kelvin foam plate is completely filled with paraffin wax for impedance matching, so that the acoustic wave may propagate through the porous foam plate. The acoustic wave velocity of the foam plate is measured using the time-of-flight (TOF) method and is used to calculate the elastic modulus of the Kelvin foam plate based on acousto-elasticity. Finite element method (FEM) and micromechanics is applied to the Kelvin foam plate to calculate the theoretical elastic modulus using a non-isotropic tetrakaidecahedron model. The predicted elastic modulus of the Kelvin foam plate from FEM and micromechanics model is similar, which is only 3-4% of the bulk material. The experimental value of the elastic modulus from the ultrasonic method is approximately twice as that of the numerical and theoretical methods because of the flexural deformation of the cell edges neglected in the ultrasonic method

Ultrasound estimation and FE analysis of elastic modulus of Kelvin foam

Energy Technology Data Exchange (ETDEWEB)

Kim, Nohyu; Yang, Seung Yong [School of Mechatronics Engineering, Korea University of Technology and Education, Cheonan (Korea, Republic of)

2016-02-15

The elastic modulus of a 3D-printed Kelvin foam plate is investigated by measuring the acoustic wave velocity of 1 MHz ultrasound. An isotropic tetrakaidecahedron foam with 3 mm unit cell is designed and printed layer upon layer to fabricate a Kelvin foam plate of 14 mm thickness with a 3D CAD/printer using ABS plastic. The Kelvin foam plate is completely filled with paraffin wax for impedance matching, so that the acoustic wave may propagate through the porous foam plate. The acoustic wave velocity of the foam plate is measured using the time-of-flight (TOF) method and is used to calculate the elastic modulus of the Kelvin foam plate based on acousto-elasticity. Finite element method (FEM) and micromechanics is applied to the Kelvin foam plate to calculate the theoretical elastic modulus using a non-isotropic tetrakaidecahedron model. The predicted elastic modulus of the Kelvin foam plate from FEM and micromechanics model is similar, which is only 3-4% of the bulk material. The experimental value of the elastic modulus from the ultrasonic method is approximately twice as that of the numerical and theoretical methods because of the flexural deformation of the cell edges neglected in the ultrasonic method.

THE DYNAMIC RESPONSE OF THERMOMETER-WELL ASSEMBLIES.

Science.gov (United States)

parameter models of the thermometric system were constructed and gave acceptable agreement with the experimental results. These models can be used to predict the dynamic behavior of any similar thermometer system. (Author)

Application of radio frequency based digital thermometer for real-time monitoring of dairy cattle rectal temperature

Directory of Open Access Journals (Sweden)

Tridib Debnath

2017-09-01

Full Text Available Aim: Dairy cattle health monitoring program becomes vital for detecting the febrile conditions to prevent the outbreak of the animal diseases as well as ensuring the fitness of the animals that are directly affecting the health of the consumers. The aim of this study was to validate real-time rectal temperature (RT data of radio frequency based digital (RFD thermometer with RT data of mercury bulb (MB thermometer in dairy cattle. Materials and Methods: Two experiments were conducted. In experiment I, six female Jersey crossbred cattle with a mean (±standard error of the mean body weight of 534.83±13.90 kg at the age of 12±0.52 years were used to record RT for 2 h on empty stomach and 2 h after feeding at 0, 30, 60, 90, and 120 min using a RFD thermometer as well as a MB thermometer. In experiment II, six female Jersey crossbred cattle were further used to record RT for 2 h before exercise and 2 h after exercise at 0, 30, 60, 90, and 120 min. Two-way repeated measures analysis of variance with post hoc comparisons by Bonferroni test was done. Results: Real-time RT data recorded by RFD thermometer as well as MB thermometer did not differ (p>0.05 before and after feeding/exercise. An increase (p<0.05 in RT after feeding/exercise in experimental crossbred cattle was recorded by both RFD thermometer and MB thermometer. Conclusion: The results obtained in the present study suggest that the body temperature recordings from RFD thermometer would be acceptable and thus RFD thermometer could work well for monitoring real-time RT in cattle.

In-situ calibration of nuclear-plant platinum resistance thermometers using Johnson noise methods. Final report

International Nuclear Information System (INIS)

Blalock, T.V.; Shepard, R.L.

1983-06-01

Methods for in situ calibration of reactor plant platinum resistance thermometers using Johnson noise measurements were tested in the laboratory and in two operating reactors: Diablo Canyon and Sequoyah. The Johnson noise methods provide an absolute measurement of the thermometer temperature and can be compared with the dc calibration of the thermometers to confirm their calibration without removing the thermometers from the plant coolant loops. Inaccuracies of less than 0.1% were obtained with these methods for ideal situations where the noise measuring equipment could be connected directly to the installed thermometer terminals. For measurements made at the ends of long extension cables, inaccuracies were 0.5 to 1.0%, at best. Extension cables must be optimized and well characterized electrically to achieve such accuracies. Other factors that affect the accuracy of these methods were evaluated

Nuclear order in silver at pico-Kelvin temperature

DEFF Research Database (Denmark)

Siemensmeyer, K.; Clausen, K.N.; Lefmann, K.

1997-01-01

Nuclear order in silver is observed by neutron diffraction at pico-Kelvin temperatures. The structure is a type-I antiferromagnet with critical field of 100 mu T. The entropy-field phase diagram was determined using the spin-dependent absorption.......Nuclear order in silver is observed by neutron diffraction at pico-Kelvin temperatures. The structure is a type-I antiferromagnet with critical field of 100 mu T. The entropy-field phase diagram was determined using the spin-dependent absorption....

The carbon dioxide thermometer and the cause of global warming

International Nuclear Information System (INIS)

Calder, Nigel

1999-01-01

Carbon dioxide in the air may be increasing because the world is warming. This possibility, which contradicts the hypothesis of an enhanced greenhouse warming driven by manmade emissions, is here pursued in two ways. First, increments in carbon dioxide are treated as readings of a natural thermometer that tracks global and hemispheric temperature deviations, as gauged by meteorologists' thermometers. Calibration of the carbon dioxide thermometer to conventional temperatures then leads to a history of carbon dioxide since 1856 that diverges from the ice-core record. Secondly, the increments of carbon dioxide can also be accounted for, without reference to temperature, by the combined effects of cosmic rays, El Nino and volcanoes. The most durable effect is due to cosmic rays. A solar wind history, used as a long-term proxy for the cosmic rays, gives a carbon dioxide history similar to that inferred from the global temperature deviations. (author)

Demonstrating the Temperature Dependence of Density via Construction of a Galilean Thermometer

Science.gov (United States)

Priest, Marie A.; Padgett, Lea W.; Padgett, Clifford W.

2011-01-01

A method for the construction of a Galilean thermometer out of common chemistry glassware is described. Students in a first-semester physical chemistry (thermodynamics) class can construct the Galilean thermometer as an investigation of the thermal expansivity of liquids and the temperature dependence of density. This is an excellent first…

Radiation Requirements and Testing of Cryogenic Thermometers for the Ilc

Science.gov (United States)

Barnett, T.; Filippov, Yu. P.; Filippova, E. Yu.; Mokhov, N. V.; Nakao, N.; Klebaner, A. L.; Korenev, S. A.; Theilacker, J. C.; Trenikhina, J.; Vaziri, K.

2008-03-01

Large quantity of cryogenic temperature sensors will be used for operation of the International Linear Collider (ILC). Most of them will be subject to high radiation doses during the accelerator lifetime. Understanding of particle energy spectra, accumulated radiation dose in thermometers and its impact on performance are vital in establishing technical specification of cryogenic thermometry for the ILC. Realistic MARS15 computer simulations were performed to understand the ILC radiation environment. Simulation results were used to establish radiation dose requirements for commercially available cryogenic thermometers. Two types of thermometers, Cernox® and TVO, were calibrated prior to irradiation using different technique. The sensors were subjected then to up to 200 kGy electron beam irradiation with kinetic energy of 5 MeV, a representative of the situation at the ILC operation. A post-irradiation behavior of the sensors was studied. The paper describes the MARS15 model, simulation results, cryogenic test set-up, irradiation tests, and cryogenic test results.

Radiation requirements and testing of cryogenic thermometers for the ILC

International Nuclear Information System (INIS)

Barnett, T.; Filippov, Yu.P.; Mokhov, N.V.; Nakao, N.; Klebaner, A.L.; Korenev, S.A.; Theilacker, J.C.; Trenikhina, J.; Vaziri, K.

2007-01-01

Large quantity of cryogenic temperature sensors will be used for operation of the International Linear Collider (ILC). Most of them will be subject to high radiation doses during the accelerator lifetime. Understanding of particle energy spectra, accumulated radiation dose in thermometers and its impact on performance are vital in establishing technical specification of cryogenic thermometry for the ILC. Realistic MARS15 computer simulations were performed to understand the ILC radiation environment. Simulation results were used to establish radiation dose requirements for commercially available cryogenic thermometers. Two types of thermometers, Cernox(reg s ign) and TVO, were calibrated prior to irradiation using different technique. The sensors were subjected then to up to 200 kGy electron beam irradiation with kinetic energy of 5 MeV, a representative of the situation at the ILC operation. A post-irradiation behavior of the sensors was studied. The paper describes the MARS15 model, simulation results, cryogenic test set-up, irradiation tests, and cryogenic test results

Low-temperature thermometry. Use of a gas thermometer as a calibration standard between 4 and 300 K

International Nuclear Information System (INIS)

Combarieu, A. de

1978-01-01

A constant volume gas thermometer was built to calibrate the various secondary thermometers used at low temperature. This gas thermometer is placed in a cryostat where any stable temperature between 4 and 300 K may be obtained. After some words about low temperature thermometry, the gas thermometer and its auxiliary equipment are described briefly; the corrections to be applied to the results are given and the article ends with a table showing the values obtained [fr

The gamma thermometer

International Nuclear Information System (INIS)

Beraud, G.; Hourtoulle, F.

1983-01-01

The search for a detecting element capable of permanently measuring localised nuclear output which would also be robust straightforward and reliable led EDF to begin development work on a new type of detector in 1976: the gamma thermometer (THG). After briefly summarising the history of the project this article goes on to describe the principle and structure of the equipment used in EDF's PWR reactors. As a result of the extensive test programme carried out it has been possible to qualify analytical and calibration methods together with the thermal and nuclear models. In conclusion, the development prospects and future of such a detecting device are outlined [fr

Kelvin-Helmholtz instability as a possible cause of edge localized modes

International Nuclear Information System (INIS)

Strauss, H.R.

1992-01-01

Edge localized modes may be a Kelvin-Helmholtz instability caused by the sheared rotation of H-mode plasmas. The Kelvin-Helmholtz instability is stabilized by coupling to Alfven waves. There is a critical velocity gradient, of the order of the Alfven velocity divided by the magnetic shear length. This is verified in a numerical simulation. The critical velocity shear is consistent with experiment. A non-linear simulation shows how the Kelvin-Helmholtz mode can cause oscillations of the velocity profile. (author). Letter-to-the-editor. 13 refs, 6 figs

Modeling ramp-hold indentation measurements based on Kelvin-Voigt fractional derivative model

Science.gov (United States)

Zhang, Hongmei; zhe Zhang, Qing; Ruan, Litao; Duan, Junbo; Wan, Mingxi; Insana, Michael F.

2018-03-01

Interpretation of experimental data from micro- and nano-scale indentation testing is highly dependent on the constitutive model selected to relate measurements to mechanical properties. The Kelvin-Voigt fractional derivative model (KVFD) offers a compact set of viscoelastic features appropriate for characterizing soft biological materials. This paper provides a set of KVFD solutions for converting indentation testing data acquired for different geometries and scales into viscoelastic properties of soft materials. These solutions, which are mostly in closed-form, apply to ramp-hold relaxation, load-unload and ramp-load creep-testing protocols. We report on applications of these model solutions to macro- and nano-indentation testing of hydrogels, gastric cancer cells and ex vivo breast tissue samples using an atomic force microscope (AFM). We also applied KVFD models to clinical ultrasonic breast data using a compression plate as required for elasticity imaging. Together the results show that KVFD models fit a broad range of experimental data with a correlation coefficient typically R 2  >  0.99. For hydrogel samples, estimation of KVFD model parameters from test data using spherical indentation versus plate compression as well as ramp relaxation versus load-unload compression all agree within one standard deviation. Results from measurements made using macro- and nano-scale indentation agree in trend. For gastric cell and ex vivo breast tissue measurements, KVFD moduli are, respectively, 1/3-1/2 and 1/6 of the elasticity modulus found from the Sneddon model. In vivo breast tissue measurements yield model parameters consistent with literature results. The consistency of results found for a broad range of experimental parameters suggest the KVFD model is a reliable tool for exploring intrinsic features of the cell/tissue microenvironments.

Investigations on perturbations of microwave dielectric resonator thermometer

International Nuclear Information System (INIS)

Yu, Lili; Zhang, Guangming; Fernicola, V; Lu, Jinchuan

2017-01-01

Investigations of antenna probe length, antenna-dielectric distance, cavity filling and humidity on microwave resonator thermometer with respect to Q , spurious mode depression, coupling strength, accuracy, shock resistance or sensitivity were carried out in order to improve the dielectric resonator thermometer performance. Significant improvement of Q and depression of spurious mode coupling were obtained when the antenna length was reduced. It also turns out that the Q and spurious mode coupling strength vary with the distance between dielectric and antenna pin, as well under appropriate antenna length. Filling the cavity with nitrogen increases coupling strength but decrease frequency-temperature sensitivity compared to a vacuum-pumped cavity. Besides, preliminary results on the microwave resonator sensitivity to air humidity were obtained. (technical note)

Process for constructing a gamma thermometer

International Nuclear Information System (INIS)

Barbet, M.J.P.; Cohen, B.S.; Robillard, M.

1982-01-01

A process is described for constructing a gamma thermometer having a substance absorbing the radiation and a set of thermocouples for measuring the local power in a fuel assembly of a nuclear reactor. A claim is particularly made for the preparation of the tube containing it and for its filling with an inert gas [fr

Accuracy of peripheral thermometers for estimating temperature: a systematic review and meta-analysis.

Science.gov (United States)

Niven, Daniel J; Gaudet, Jonathan E; Laupland, Kevin B; Mrklas, Kelly J; Roberts, Derek J; Stelfox, Henry Thomas

2015-11-17

Body temperature is commonly used to screen patients for infectious diseases, establish diagnoses, monitor therapy, and guide management decisions. To determine the accuracy of peripheral thermometers for estimating core body temperature in adults and children. MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, and CINAHL Plus from inception to July 2015. Prospective studies comparing the accuracy of peripheral (tympanic membrane, temporal artery, axillary, or oral) thermometers with central (pulmonary artery catheter, urinary bladder, esophageal, or rectal) thermometers. 2 reviewers extracted data on study characteristics, methods, and outcomes and assessed the quality of individual studies. 75 studies (8682 patients) were included. Most studies were at high or unclear risk of patient selection bias (74%) or index test bias (67%). Compared with central thermometers, peripheral thermometers had pooled 95% limits of agreement (random-effects meta-analysis) outside the predefined clinically acceptable range (± 0.5 °C), especially among patients with fever (-1.44 °C to 1.46 °C for adults; -1.49 °C to 0.43 °C for children) and hypothermia (-2.07 °C to 1.90 °C for adults; no data for children). For detection of fever (bivariate random-effects meta-analysis), sensitivity was low (64% [95% CI, 55% to 72%]; I2 = 95.7%; P temperature measurement techniques are limited. Pooled data are associated with interstudy heterogeneity that is not fully explained by stratified and metaregression analyses. Peripheral thermometers do not have clinically acceptable accuracy and should not be used when accurate measurement of body temperature will influence clinical decisions. None.

MEMS Tunneling Micro Thermometer Based onTip Deflection of Bimetallic Cantilever Beam

Directory of Open Access Journals (Sweden)

Samrand K. Nezhadian

2007-10-01

Full Text Available Micro-electro-mechanical (MEM technology promises to significantly reduce the size, weight and cost of a variety of sensor systems. In this article has been described a highly sensitive novel type of thermometer based on deflection of a “bimetallic” microbeam. The proposed thermometer converts the thermal changes of a cantilevered bimetallic beam of submillimeter size into an electrical signal through tunneling-current modulation. The governing thermo-mechanical equation of a bimetallic cantilever beam has been derived and solved analytically. The obtained results show that the proposed tunneling micro thermometer is very sensitive to temperature changes due to exponential increasing of tunneling current but because of small gap between metallic electrodes, measurable range of temperature changes is small.

Study of equatorial Kelvin waves using the MST radar and radiosonde observations

Directory of Open Access Journals (Sweden)

P. Kishore

2005-06-01

Full Text Available In this paper an attempt has been made to study equatorial Kelvin waves using a high power coherent VHF radar located at Gadanki (13.5° N, 79.2° E, a tropical station in the Indian sub-continent. Simultaneous radiosonde observations taken from a nearby meteorological station located in Chennai (13.04° N, 80.17° E were also used to see the coherence in the observed structures. These data sets were analyzed to study the mean winds and equatorial waves in the troposphere and lower stratosphere. Equatorial waves with different periodicities were identified. In the present study, particular attention has been given to the fast Kelvin wave (6.5-day and slow Kelvin wave (16-day. Mean zonal wind structures were similar at both locations. The fast Kelvin wave amplitudes were somewhat similar in both observations and the maximum amplitude is about 8m/s. The phase profiles indicated a slow downward progression. The slow Kelvin wave (16-day amplitudes shown by the radiosonde measurements are a little larger than the radar derived amplitudes. The phase profiles showed downward phase progression and it translates into a vertical wavelength of ~10-12km. The radar and radiosonde derived amplitudes of fast and slow Kelvin waves are larger at altitudes near the tropopause (15-17km, where the mean wind attains westward maximum.

Simulated Interannual Modulation of Intraseasonal Kelvin Waves in the Equatorial Indian Ocean

Directory of Open Access Journals (Sweden)

Iskhaq Iskandar

2016-12-01

Full Text Available Outputs from a high-resolution ocean general circulation model (OGCM for the period of 1990-2003 indicate an interannual modulation of intraseasonal Kelvin waves along the equatorial Indian Ocean. During normal conditions without IOD event, the first mode explains about 30-40% of the total variance in the western (60-65ºE and central (75-80ºE basin, while the second mode contributes up to 45% to the total variance in the central basin around the longitude of 82ºE. In contrast, during the 1997/98 IOD event, the fourth mode caused about 40% of the total variance in the central and eastern basin. During the 1994 IOD event, the contribution from the fourth baroclinic mode in the eastern basin caused 45% of the total variance. In the central basin, the second and the fourth baroclinic mode caused almost the same variance (~40%. The variations in the characteristics of the intraseasonal Kelvin waves are related to variations in the vertical stratification. During the IOD event, the pycnocline in the eastern basin was raised by about 50 m and the stratification at the upper level is strengthened, while it is weakened at lower levels. These changes lead to an increase in the contribution of higher-order baroclinic modes.

Towards a practical Johnson noise thermometer for long-term measurements in harsh environments

International Nuclear Information System (INIS)

Greenen, Adam; Pearce, Jonathan; Cruickshank, David; Bramley, Paul

2015-01-01

The impact of mechanical and chemical changes in conventional sensors such as thermocouples and resistance thermometers can be avoided by instead using temperature sensors based on fundamental thermometry. A prime example of this is Johnson noise thermometry, which is based on measurement of the fluctuations in the voltage of a resistor arising from thermal motion of charge carriers - i.e. the 'Johnson noise'. A Johnson noise thermometer never needs calibration and is insensitive to the condition of the sensor material. It is therefore ideally suited to long-term temperature measurements in harsh environments, such as nuclear reactor coolant circuits, in-pile measurements, nuclear waste management and storage, and severe accident monitoring. There have been a number of previous attempts to develop a Johnson noise thermometer for the nuclear industry, but none have reached commercial exploitation because of technical problems in practical implementation. The main challenge is to extract the tiny Johnson noise signal from ambient electrical noise influences, both from the internal amplification electronics, and from external electrical noise sources. Recent advances in electronics technology and digital signal processing techniques have opened up new possibilities for developing a viable, practical Johnson noise thermometer. We describe a project funded by the UK Technology Strategy Board (now Innovate UK) 'Developing the nuclear supply chain' call, currently underway, to develop a practical Johnson noise thermometer that makes use of innovative electronics for ultralow noise amplification and signal processing. The new electronics technology has the potential to help overcome the problems encountered with previous attempts at constructing a practical Johnson noise thermometer. An outline of the new developments is presented, together with an overview of the current status of the project. (authors)

Towards a practical Johnson noise thermometer for long-term measurements in harsh environments

Energy Technology Data Exchange (ETDEWEB)

Greenen, Adam; Pearce, Jonathan [National Physical Laboratory, Hampton Road, Teddington, TW11 0LW, (United Kingdom); Cruickshank, David; Bramley, Paul [Metrosol Limited, Plum Park Estate, Watling Street, Paulerspury, Northamptonshire, NN12 6LQ, (United Kingdom)

2015-07-01

The impact of mechanical and chemical changes in conventional sensors such as thermocouples and resistance thermometers can be avoided by instead using temperature sensors based on fundamental thermometry. A prime example of this is Johnson noise thermometry, which is based on measurement of the fluctuations in the voltage of a resistor arising from thermal motion of charge carriers - i.e. the 'Johnson noise'. A Johnson noise thermometer never needs calibration and is insensitive to the condition of the sensor material. It is therefore ideally suited to long-term temperature measurements in harsh environments, such as nuclear reactor coolant circuits, in-pile measurements, nuclear waste management and storage, and severe accident monitoring. There have been a number of previous attempts to develop a Johnson noise thermometer for the nuclear industry, but none have reached commercial exploitation because of technical problems in practical implementation. The main challenge is to extract the tiny Johnson noise signal from ambient electrical noise influences, both from the internal amplification electronics, and from external electrical noise sources. Recent advances in electronics technology and digital signal processing techniques have opened up new possibilities for developing a viable, practical Johnson noise thermometer. We describe a project funded by the UK Technology Strategy Board (now Innovate UK) 'Developing the nuclear supply chain' call, currently underway, to develop a practical Johnson noise thermometer that makes use of innovative electronics for ultralow noise amplification and signal processing. The new electronics technology has the potential to help overcome the problems encountered with previous attempts at constructing a practical Johnson noise thermometer. An outline of the new developments is presented, together with an overview of the current status of the project. (authors)

Influence of Thermal Cycling on Cryogenic Thermometers

CERN Document Server

Balle, C; Rieubland, Jean Michel; Suraci, A; Togny, F; Vauthier, N

1999-01-01

The stringent requirements on temperature control of the superconducting magnets for the Large Hadron Collider (LHC), impose that the cryogenic temperature sensors meet compelling demands such as long-term stability, radiation hardness, readout accuracy better than 5 mK at 1.8 K and compatibility with industrial control equipment. This paper presents the results concerning long-term stability of resistance temperature sensors submitted to cryogenic thermal cycles. For this task a simple test facility has been designed, constructed and put into operation for cycling simultaneously 115 cryogenic thermometers between 300 K and 4.2 K. A thermal cycle is set to last 71/4 hours: 3 hours for either cooling down or warming up the sensors and 1 respectively 1/4 hour at steady temperature conditions at each end of the temperature cycle. A Programmable Logic Controller (PLC) drives automatically this operation by reading 2 thermometers and actuating on 3 valves and 1 heater. The first thermal cycle was accomplished in a...

Measurement time and statistics for a noise thermometer with a synthetic-noise reference

Science.gov (United States)

White, D. R.; Benz, S. P.; Labenski, J. R.; Nam, S. W.; Qu, J. F.; Rogalla, H.; Tew, W. L.

2008-08-01

This paper describes methods for reducing the statistical uncertainty in measurements made by noise thermometers using digital cross-correlators and, in particular, for thermometers using pseudo-random noise for the reference signal. First, a discrete-frequency expression for the correlation bandwidth for conventional noise thermometers is derived. It is shown how an alternative frequency-domain computation can be used to eliminate the spectral response of the correlator and increase the correlation bandwidth. The corresponding expressions for the uncertainty in the measurement of pseudo-random noise in the presence of uncorrelated thermal noise are then derived. The measurement uncertainty in this case is less than that for true thermal-noise measurements. For pseudo-random sources generating a frequency comb, an additional small reduction in uncertainty is possible, but at the cost of increasing the thermometer's sensitivity to non-linearity errors. A procedure is described for allocating integration times to further reduce the total uncertainty in temperature measurements. Finally, an important systematic error arising from the calculation of ratios of statistical variables is described.

Effect of on-chip filter on Coulomb blockade thermometer

International Nuclear Information System (INIS)

Roschier, L; Penttilä, J S; Gunnarsson, D; Prunnila, M; Meschke, M; Savin, A

2012-01-01

Coulomb Blockade Thermometer (CBT) is a primary thermometer based on electric conductance of normal tunnel junction arrays. One limitation for CBT use at the lowest temperatures has been due to environmental noise heating. To improve on this limitation, we have done measurements on CBT sensors fabricated with different on-chip filtering structures in a dilution refrigerator with a base temperature of 10 mK. The CBT sensors were produced with a wafer scale tunnel junction process. We present how the different on-chip filtering schemes affect the limiting saturation temperatures and show that CBT sensors with proper on-chip filtering work at temperatures below 20 mK and are tolerant to noisy environment.

27 CFR 30.22 - Hydrometers and thermometers.

Science.gov (United States)

2010-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Hydrometers and... BUREAU, DEPARTMENT OF THE TREASURY LIQUORS GAUGING MANUAL Gauging Instruments § 30.22 Hydrometers and thermometers. The hydrometers used are graduated to read the proof of aqueous alcoholic solutions at 60 degrees...

Challenges for Super-Resolution Localization Microscopy and Biomolecular Fluorescent Nano-Probing in Cancer Research

Science.gov (United States)

Ilić, Nataša; Pilarczyk, Götz; Lee, Jin-Ho; Logeswaran, Abiramy; Borroni, Aurora Paola; Krufczik, Matthias; Theda, Franziska; Waltrich, Nadine; Bestvater, Felix; Hildenbrand, Georg; Cremer, Christoph; Blank, Michael

2017-01-01

Understanding molecular interactions and regulatory mechanisms in tumor initiation, progression, and treatment response are key requirements towards advanced cancer diagnosis and novel treatment procedures in personalized medicine. Beyond decoding the gene expression, malfunctioning and cancer-related epigenetic pathways, investigations of the spatial receptor arrangements in membranes and genome organization in cell nuclei, on the nano-scale, contribute to elucidating complex molecular mechanisms in cells and tissues. By these means, the correlation between cell function and spatial organization of molecules or molecular complexes can be studied, with respect to carcinogenesis, tumor sensitivity or tumor resistance to anticancer therapies, like radiation or antibody treatment. Here, we present several new applications for bio-molecular nano-probes and super-resolution, laser fluorescence localization microscopy and their potential in life sciences, especially in biomedical and cancer research. By means of a tool-box of fluorescent antibodies, green fluorescent protein (GFP) tagging, or specific oligonucleotides, we present tumor relevant re-arrangements of Erb-receptors in membranes, spatial organization of Smad specific ubiquitin protein ligase 2 (Smurf2) in the cytosol, tumor cell characteristic heterochromatin organization, and molecular re-arrangements induced by radiation or antibody treatment. The main purpose of this article is to demonstrate how nano-scaled distance measurements between bio-molecules, tagged by appropriate nano-probes, can be applied to elucidate structures and conformations of molecular complexes which are characteristic of tumorigenesis and treatment responses. These applications open new avenues towards a better interpretation of the spatial organization and treatment responses of functionally relevant molecules, at the single cell level, in normal and cancer cells, offering new potentials for individualized medicine. PMID:28956810

Challenges for Super-Resolution Localization Microscopy and Biomolecular Fluorescent Nano-Probing in Cancer Research

Directory of Open Access Journals (Sweden)

Michael Hausmann

2017-09-01

Full Text Available Understanding molecular interactions and regulatory mechanisms in tumor initiation, progression, and treatment response are key requirements towards advanced cancer diagnosis and novel treatment procedures in personalized medicine. Beyond decoding the gene expression, malfunctioning and cancer-related epigenetic pathways, investigations of the spatial receptor arrangements in membranes and genome organization in cell nuclei, on the nano-scale, contribute to elucidating complex molecular mechanisms in cells and tissues. By these means, the correlation between cell function and spatial organization of molecules or molecular complexes can be studied, with respect to carcinogenesis, tumor sensitivity or tumor resistance to anticancer therapies, like radiation or antibody treatment. Here, we present several new applications for bio-molecular nano-probes and super-resolution, laser fluorescence localization microscopy and their potential in life sciences, especially in biomedical and cancer research. By means of a tool-box of fluorescent antibodies, green fluorescent protein (GFP tagging, or specific oligonucleotides, we present tumor relevant re-arrangements of Erb-receptors in membranes, spatial organization of Smad specific ubiquitin protein ligase 2 (Smurf2 in the cytosol, tumor cell characteristic heterochromatin organization, and molecular re-arrangements induced by radiation or antibody treatment. The main purpose of this article is to demonstrate how nano-scaled distance measurements between bio-molecules, tagged by appropriate nano-probes, can be applied to elucidate structures and conformations of molecular complexes which are characteristic of tumorigenesis and treatment responses. These applications open new avenues towards a better interpretation of the spatial organization and treatment responses of functionally relevant molecules, at the single cell level, in normal and cancer cells, offering new potentials for individualized medicine.

Cause elucidation of sodium leakage incident at `Monju` reactor. Vibration of thermometer due to fluid force

Energy Technology Data Exchange (ETDEWEB)

Iwata, Koji; Wada, Yusaku; Morishita, Masaki; Yamaguchi, Akira; Ichimiya, Masakazu [Power Reactor and Nuclear Fuel Development Corp., Oarai, Ibaraki (Japan). Oarai Engineering Center

1997-01-01

This is a report of summarized results of investigation and analysis on fracture of thermometer which is direct reason of sodium leakage incident at the second main cooling system of fast breeder reactor `Monju`. Various surveys such as on various damage factors, on flowing power vibrational features containing flowing power vibrational test of thermometer, on evaluation of high cycle fatigue due to flowing power vibration and details on propagation of and fracture due to fatigue crack, on why only said thermometer damaged, and so forth were executed. As results of these examinations, a decision was arrived that high cycle fatigue due to vibration formed by fluid force (fluid force vibration) was a direct cause of the thermometer damage. (G.K.)

Cryogenic thermometer calibration system using a helium cooling loop and a temperature controller [for LHC magnets

CERN Document Server

Chanzy, E; Thermeau, J P; Bühler, S; Joly, C; Casas-Cubillos, J; Balle, C

1998-01-01

The IPN-Orsay and CERN are designing in close collaboration a fully automated cryogenic thermometer calibration facility which will calibrate in 3 years 10,000 cryogenic thermometers required for the Large Hadron Collider (LHC) operation. A reduced-scale model of the calibration facility has been developed, which enables the calibration of ten thermometers by comparison with two rhodium-iron standard thermometers in the 1.8 K to 300 K temperature range under vacuum conditions. The particular design, based on a helium cooling loop and an electrical temperature controller, gives good dynamic performances. This paper describes the experimental set-up and the data acquisition system. Results of experimental runs are also presented along with the estimated global accuracy for the calibration. (3 refs).

Molecular magnetic hysteresis at 60 kelvin in dysprosocenium

Science.gov (United States)

Goodwin, Conrad A. P.; Ortu, Fabrizio; Reta, Daniel; Chilton, Nicholas F.; Mills, David P.

2017-08-01

Lanthanides have been investigated extensively for potential applications in quantum information processing and high-density data storage at the molecular and atomic scale. Experimental achievements include reading and manipulating single nuclear spins, exploiting atomic clock transitions for robust qubits and, most recently, magnetic data storage in single atoms. Single-molecule magnets exhibit magnetic hysteresis of molecular origin—a magnetic memory effect and a prerequisite of data storage—and so far lanthanide examples have exhibited this phenomenon at the highest temperatures. However, in the nearly 25 years since the discovery of single-molecule magnets, hysteresis temperatures have increased from 4 kelvin to only about 14 kelvin using a consistent magnetic field sweep rate of about 20 oersted per second, although higher temperatures have been achieved by using very fast sweep rates (for example, 30 kelvin with 200 oersted per second). Here we report a hexa-tert-butyldysprosocenium complex—[Dy(Cpttt)2][B(C6F5)4], with Cpttt = {C5H2tBu3-1,2,4} and tBu = C(CH3)3—which exhibits magnetic hysteresis at temperatures of up to 60 kelvin at a sweep rate of 22 oersted per second. We observe a clear change in the relaxation dynamics at this temperature, which persists in magnetically diluted samples, suggesting that the origin of the hysteresis is the localized metal-ligand vibrational modes that are unique to dysprosocenium. Ab initio calculations of spin dynamics demonstrate that magnetic relaxation at high temperatures is due to local molecular vibrations. These results indicate that, with judicious molecular design, magnetic data storage in single molecules at temperatures above liquid nitrogen should be possible.

Nano-computed tomography. Technique and applications; Nanocomputertomografie. Technik und Applikationen

Energy Technology Data Exchange (ETDEWEB)

Kampschulte, M.; Sender, J.; Litzlbauer, H.D.; Althoehn, U.; Schwab, J.D.; Alejandre-Lafont, E.; Martels, G.; Krombach, G.A. [University Hospital Giessen (Germany). Dept. of Diagnostic and Interventional Radiology; Langheinirch, A.C. [BG Trauma Hospital Frankfurt/Main (Germany). Dept. of Diagnostic and Interventional Radiology

2016-02-15

Nano-computed tomography (nano-CT) is an emerging, high-resolution cross-sectional imaging technique and represents a technical advancement of the established micro-CT technology. Based on the application of a transmission target X-ray tube, the focal spot size can be decreased down to diameters less than 400 nanometers (nm). Together with specific detectors and examination protocols, a superior spatial resolution up to 400 nm (10 % MTF) can be achieved, thereby exceeding the resolution capacity of typical micro-CT systems. The technical concept of nano-CT imaging as well as the basics of specimen preparation are demonstrated exemplarily. Characteristics of atherosclerotic plaques (intraplaque hemorrhage and calcifications) in a murine model of atherosclerosis (ApoE{sub (-/-)}/LDLR{sub (-/-)} double knockout mouse) are demonstrated in the context of superior spatial resolution in comparison to micro-CT. Furthermore, this article presents the application of nano-CT for imaging cerebral microcirculation (murine), lung structures (porcine), and trabecular microstructure (ovine) in contrast to micro-CT imaging. This review shows the potential of nano-CT as a radiological method in biomedical basic research and discusses the application of experimental, high resolution CT techniques in consideration of other high resolution cross-sectional imaging techniques.

New blackbody standard for the evaluation and calibration of tympanic ear thermometers at the NPL, United Kingdom

Science.gov (United States)

McEvoy, Helen C.; Simpson, Robert; Machin, Graham

2004-04-01

The use of infrared tympanic thermometers for monitoring patient health is widespread. However, studies into the performance of these thermometers have questioned their accuracy and repeatability. To give users confidence in these devices, and to provide credibility in the measurements, it is necessary for them to be tested using an accredited, standard blackbody source, with a calibration traceable to the International Temperature Scale of 1990 (ITS-90). To address this need the National Physical Laboratory (NPL), UK, has recently set up a primary ear thermometer calibration (PET-C) source for the evaluation and calibration of tympanic (ear) thermometers over the range from 15 °C to 45 °C. The overall uncertainty of the PET-C source is estimated to be +/- 0.04 °C at k = 2. The PET-C source meets the requirements of the European Standard EN 12470-5: 2003 Clinical thermometers. It consists of a high emissivity blackbody cavity immersed in a bath of stirred liquid. The temperature of the blackbody is determined using an ITS-90 calibrated platinum resistance thermometer inserted close to the rear of the cavity. The temperature stability and uniformity of the PET-C source was evaluated and its performance validated. This paper provides a description of the PET-C along with the results of the validation measurements. To further confirm the performance of the PET-C source it was compared to the standard ear thermometer calibration sources of the National Metrology Institute of Japan (NMIJ), Japan and the Physikalisch-Technische Bundesanstalt (PTB), Germany. The results of this comparison will also be briefly discussed. The PET-C source extends the capability for testing ear thermometers offered by the NPL body temperature fixed-point source, described previously. An update on the progress with the commercialisation of the fixed-point source will be given.

Calibration of Cryogenic Thermometers for the LHC

CERN Document Server

Balle, Ch; Vauthier, N; Thermeau, JP

2008-01-01

6000 cryogenic temperature sensors of resistive type covering the range from room temperature down to 1.6 K are installed on the LHC machine. In order to meet the stringent requirements on temperature control of the superconducting magnets, each single sensor needs to be calibrated individually. In the framework of a special contribution, IPN (Institut de Physique Nucléaire) in Orsay, France built and operated a calibration facility with a throughput of 80 thermometers per week. After reception from the manufacturer, the thermometer is first assembled onto a support specific to the measurement environment, and then thermally cycled ten times and calibrated at least once from 1.6 to 300 K. The procedure for each of these interventions includes various measurements and the acquired data is recorded in an ORACLE®-database. Furthermore random calibrations on some samples are executed at CERN to crosscheck the coherence between the approximation data obtained by both IPN and CERN. In the range of 1.5 K to 30 K...

Cancer Nano medicine

International Nuclear Information System (INIS)

Li, H.; Pike, M.M.; Luo, X.; Liu, L.H.

2013-01-01

Bioengineered nano materials have inspired revolutionary imaging and drug delivery methods whose clinical application in cancer research has resulted in powerful medical devices for early diagnosis, treatment, and prevention of cancer. Recent advances in super imaging agents have resulted in improved resolution and sensitivity. For instance, fluorescent quantum dots with wavelength-tunable emissions, plasmon-resonant gold nano structures with shape-controlled near-infrared absorptions, and MRI-active iron oxide nanoparticles are well-established molecular imaging probes for noninvasive cancer imaging. Nano materials are also considered to be the most effective vectors that can break through transport bio barriers and deliver a constant dose of multiple therapeutic agents to tumors and intracellular endocytic compartments for cancer gene therapy, immunotherapy, or chemotherapy. Furthermore, nano wire- or nano tube-based electronic devices demonstrate extraordinary sensitivity capable of detection at the single molecule or protein level. It is anticipated that developing nano technology-driven imaging, sensing, and therapeutic systems will dramatically advance cancer research and clinical treatments.

Structure-­mediated nano-­biophotonics

DEFF Research Database (Denmark)

Glückstad, Jesper; Villangca, Mark Jayson; Bañas, Andrew Rafael

2015-01-01

The synergy between photonics, nanotechnology and biotechnology is spawning the emerging fields of nano-biotechnology and nano-biophotonics. Photonic innovations already hurdle the diffraction barrier for imaging with nanoscopic resolutions. However, scientific hypothesis testing demands tools...

Specific heats of lunar surface materials from 90 to 350 degrees Kelvin

Science.gov (United States)

Robie, R.A.; Hemingway, B.S.; Wilson, W.H.

1970-01-01

The specific heats of lunar samples 10057 and 10084 returned by the Apollo 11 mission have been measured between 90 and 350 degrees Kelvin by use of an adiabatic calorimeter. The samples are representative of type A vesicular basalt-like rocks and of finely divided lunar soil. The specific heat of these materials changes smoothly from about 0.06 calorie per gram per degree at 90 degrees Kelvin to about 0.2 calorie per gram per degree at 350 degrees Kelvin. The thermal parameter ??=(k??C)-1/2 for the lunar surface will accordingly vary by a factor of about 2 between lunar noon and midnight.

Kelvin-Helmholtz evolution in subsonic cold streams feeding galaxies

Science.gov (United States)

Angulo, Adrianna; Coffing, S.; Kuranz, C.; Drake, R. P.; Klein, S.; Trantham, M.; Malamud, G.

2017-10-01

The most prolific star formers in cosmological history lie in a regime where dense filament structures carried substantial mass into the galaxy to sustain star formation without producing a shock. However, hydrodynamic instabilities present on the filament surface limit the ability of such structures to deliver dense matter deeply enough to sustain star formation. Simulations lack the finite resolution necessary to allow fair treatment of the instabilities present at the stream boundary. Using the Omega EP laser, we simulate this mode of galaxy formation with a cold, dense, filament structure within a hotter, subsonic flow and observe the interface evolution. Machined surface perturbations stimulate the development of the Kelvin-Helmholtz (KH) instability due to the resultant shear between the two media. A spherical crystal imaging system produces high-resolution radiographs of the KH structures along the filament surface. The results from the first experiments of this kind, using a rod with single-mode, long-wavelength modulations, will be discussed. This work is funded by the U.S. Department of Energy, through the NNSA-DS and SC-OFES Joint Program in High-Energy-Density Laboratory Plasmas, Grant Number DE-NA0002956, and the National Laser User Facility Program, Grant Number DE-NA0002719, and through.

Direct probing of electron and hole trapping into nano-floating-gate in organic field-effect transistor nonvolatile memories

Energy Technology Data Exchange (ETDEWEB)

Cui, Ze-Qun; Wang, Shun; Chen, Jian-Mei; Gao, Xu; Dong, Bin, E-mail: wangsd@suda.edu.cn, E-mail: chilf@suda.edu.cn, E-mail: bdong@suda.edu.cn; Chi, Li-Feng, E-mail: wangsd@suda.edu.cn, E-mail: chilf@suda.edu.cn, E-mail: bdong@suda.edu.cn; Wang, Sui-Dong, E-mail: wangsd@suda.edu.cn, E-mail: chilf@suda.edu.cn, E-mail: bdong@suda.edu.cn [Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, Institute of Functional Nano and Soft Materials (FUNSOM), Soochow University, Suzhou, Jiangsu 215123 (China)

2015-03-23

Electron and hole trapping into the nano-floating-gate of a pentacene-based organic field-effect transistor nonvolatile memory is directly probed by Kelvin probe force microscopy. The probing is straightforward and non-destructive. The measured surface potential change can quantitatively profile the charge trapping, and the surface characterization results are in good accord with the corresponding device behavior. Both electrons and holes can be trapped into the nano-floating-gate, with a preference of electron trapping than hole trapping. The trapped charge quantity has an approximately linear relation with the programming/erasing gate bias, indicating that the charge trapping in the device is a field-controlled process.

Direct probing of electron and hole trapping into nano-floating-gate in organic field-effect transistor nonvolatile memories

International Nuclear Information System (INIS)

Cui, Ze-Qun; Wang, Shun; Chen, Jian-Mei; Gao, Xu; Dong, Bin; Chi, Li-Feng; Wang, Sui-Dong

2015-01-01

Electron and hole trapping into the nano-floating-gate of a pentacene-based organic field-effect transistor nonvolatile memory is directly probed by Kelvin probe force microscopy. The probing is straightforward and non-destructive. The measured surface potential change can quantitatively profile the charge trapping, and the surface characterization results are in good accord with the corresponding device behavior. Both electrons and holes can be trapped into the nano-floating-gate, with a preference of electron trapping than hole trapping. The trapped charge quantity has an approximately linear relation with the programming/erasing gate bias, indicating that the charge trapping in the device is a field-controlled process

Development and psychometric testing of a new tool for detecting moral distress: the Moral Distress Thermometer.

Science.gov (United States)

Wocial, Lucia D; Weaver, Michael T

2013-01-01

To report the development and psychometric testing of the Moral Distress Thermometer. The Moral Distress Thermometer is a new screening tool to measure moral distress in nurses who practise in the hospital setting. Moral distress occurs when one knows the ethically correct thing to do, but is prevented from acting on that perceived obligation. It is a well documented phenomenon with negative consequences that may be experienced by nurses. Creating an instrument to effectively and efficiently measure moral distress in a timely way has been identified as a priority for nursing. This study used a cross-sectional survey design. Data collection for this research occurred in 2009. Participants simultaneously completed either the adult or pediatric version of the Moral Distress Scale version 2009 and the Moral Distress Thermometer. A total of 529 participants from various clinical areas completed both tools. Coefficients alpha were adequate for both Adult (0·90) and Pediatric (0·92) Moral Distress Scale 2009 scales. Statistically significant Pearson correlations were found for the Moral Distress Thermometer with Adult Moral Distress Scale 2009 and Pediatric Moral Distress Scale 2009 and higher Moral Distress Thermometer, Adult Moral Distress Scale 2009 and Pediatric Moral Distress Scale 2009 means for participants who had left or who considered leaving a position because of moral distress. These findings provide support for the validity of the Moral Distress Thermometer. © 2012 Blackwell Publishing Ltd.

Very high temperature ultrasonic thermometer

International Nuclear Information System (INIS)

Jorzik, E.

1983-01-01

An ultrasonic thermometer comprises an electric pulse transducer head, a pulse transmission line, a notched sensor wire attached to and extending along the axis of said transmission line and a sheath enclosing the transmission line and the sensor wire, a portion of the interior face of the sheath being covered by a stuffing material along at least the length of the notched part of the sensor wire, such that contact between the sensor wire and the stuffing material does not substantially give rise to reflection of an ultrasonic pulse at the point of contact. (author)

¿Qué es una onda ecuatorial de Kelvin?

OpenAIRE

Ripa, P.

1980-01-01

La importancia del estudio de las ondas de Kelvin (ecuatoriales o costeras) radica, en parte, en el hecho de que éstas proveen un mecanismo eficaz para el transporte de energía (en la forma de perturbaciones de densidad y corriente) en una dirección particular. Estas señales se trasladan sin dispersión, es decir, sin cambiar de forma. Por otra parte, una onda de Kelvin provee un ejemplo muy sencillo de dos fenómenos fundamentales de la Oceanografía Física de frecuencias: el balance geostrófic...

Measuring Total Column Water Vapor by Pointing an Infrared Thermometer at the Sky

Science.gov (United States)

Mims, Forrest M., III; Chambers, Lin H.; Brooks, David R.

2011-01-01

A 2-year study affirms that the temperature (Tz) indicated by an inexpensive ($20 to $60) IR thermometer pointed at the cloud-free zenith sky provides an approximate indication of the total column water vapor (precipitable water or PW). PW was measured by a MICROTOPS II sun photometer. The coefficient of correlation (r2) of the PW and Tz was 0.90, and the rms difference was 3.2 mm. A comparison of the Tz data with the PW provided by a GPS site 31 km NNE yielded an r2 of 0.79, and an rms difference of 5.8 mm. An expanded study compared Tz from eight IR thermometers with PW at various times during the day and night from 17 May to 18 October 2010, mainly at the Texas site and 10 days at Hawaii's Mauna Loa Observatory (MLO). The best results of this comparison were provided by two IR thermometers models that yielded an r2 of 0.96 and an rms difference with the PW of 2.7 mm. The results of both the ongoing 2-year study and the 5-month instrument comparison show that IR thermometers can measure PW with an accuracy (rms difference/mean PW) approaching 10%, the accuracy typically ascribed to sun photometers.

Kelvin probe force microscopy from single charge detection to device characterization

CERN Document Server

Glatzel, Thilo

2018-01-01

This book provides a comprehensive introduction to the methods and variety of Kelvin probe force microscopy, including technical details. It also offers an overview of the recent developments and numerous applications, ranging from semiconductor materials, nanostructures and devices to sub-molecular and atomic scale electrostatics. In the last 25 years, Kelvin probe force microscopy has developed from a specialized technique applied by a few scanning probe microscopy experts into a tool used by numerous research and development groups around the globe. This sequel to the editors’ previous volume “Kelvin Probe Force Microscopy: Measuring and Compensating Electrostatic Forces,” presents new and complementary topics. It is intended for a broad readership, from undergraduate students to lab technicians and scanning probe microscopy experts who are new to the field.

An Embeddable Strain Sensor with 30 Nano-Strain Resolution Based on Optical Interferometry

Directory of Open Access Journals (Sweden)

Chen Zhu

2018-04-01

Full Text Available A cost-effective, robust and embeddable optical interferometric strain sensor with nanoscale strain resolution is presented in this paper. The sensor consists of an optical fiber, a quartz rod with one end coated with a thin gold layer, and two metal shells employed to transfer the strain and orient and protect the optical fiber and the quartz rod. The optical fiber endface, combining with the gold-coated surface, forms an extrinsic Fabry–Perot interferometer. The sensor was firstly calibrated, and the result showed that our prototype sensor could provide a measurement resolution of 30 nano-strain (nε and a sensitivity of 10.01 µε/µm over a range of 1000 µε. After calibration of the sensor, the shrinkage strain of a cubic brick of mortar in real time during the drying process was monitored. The strain sensor was compared with a commercial linear variable displacement transducer, and the comparison results in four weeks demonstrated that our sensor had much higher measurement resolution and gained more detailed and useful information. Due to the advantages of the extremely simple, robust and cost-effective configuration, it is believed that the sensor is significantly beneficial to practical applications, especially for structural health monitoring.

A Fluorescent Thermometer Based on a Pyrene-Labeled Thermoresponsive Polymer

Directory of Open Access Journals (Sweden)

Ulrich S. Schubert

2010-08-01

Full Text Available Thermoresponsive polymers that undergo a solubility transition by variation of the temperature are important materials for the development of ‘smart’ materials. In this contribution we exploit the solubility phase transition of poly(methoxy diethylene glycol methacrylate, which is accompanied by a transition from hydrophilic to hydrophobic, for the development of a fluorescent thermometer. To translate the polymer phase transition into a fluorescent response, the polymer was functionalized with pyrene resulting in a change of the emission based on the microenvironment. This approach led to a soluble polymeric fluorescent thermometer with a temperature range from 11 °C to 21 °C. The polymer phase transition that occurs during sensing is studied in detail by dynamic light scattering.

A Phase-Locked Loop Continuous Wave Sonic Anemometer-Thermometer

DEFF Research Database (Denmark)

Larsen, Søren Ejling; Weller, F. W.; Busings, J. A.

1979-01-01

A continuous wake sonic anemometer-thermometer has been developed for simultaneous measurements of vertical velocity and temperature. The phase angle fluctuations are detected by means of a monolithic integrated phase-locked loop, the latter feature providing for inexpensive and accurate...

Automatic kelvin probe compatible with ultrahigh vacuum

NARCIS (Netherlands)

Baikie, I.D.; van der Werf, Kees; Oerbekke, H.; Broeze, J.; van Silfhout, Arend

1989-01-01

This article describes a new type of in situ ultrahigh‐vacuum compatible kelvin probe based on a voice‐coil driving mechanism. This design exhibits several advantages over conventional mechanical feed‐through and (in situ) piezoelectric devices in regard to the possibility of multiple probe

Potential profile and photovoltaic effect in nanoscale lateral pn junction observed by Kelvin probe force microscopy

International Nuclear Information System (INIS)

Nowak, Roland; Moraru, Daniel; Mizuno, Takeshi; Jablonski, Ryszard; Tabe, Michiharu

2014-01-01

Nanoscale pn junctions have been investigated by Kelvin probe force microscopy and several particular features were found. Within the depletion region, a localized noise area is observed, induced by temporal fluctuations of dopant states. Electronic potential landscape is significantly affected by dopants with ground-state energies deeper than in bulk. Finally, the effects of light illumination were studied and it was found that the depletion region shifts its position as a function of light intensity. This is ascribed to charge redistribution within the pn junction as a result of photovoltaic effect and due to the impact of deepened-level dopants. - Highlights: • In pn nano-junctions, temporal potential fluctuations are found in depletion layer. • Fluctuations are due to frequent capture and emission of free carriers by dopants. • Depletion layer position shifts as a function of the intensity of irradiated light. • The depletion layer shifts are due to changes of deep-level dopants' charge states

Investigation of Kelvin wave periods during Hai-Tang typhoon using Empirical Mode Decomposition

Science.gov (United States)

Kishore, P.; Jayalakshmi, J.; Lin, Pay-Liam; Velicogna, Isabella; Sutterley, Tyler C.; Ciracì, Enrico; Mohajerani, Yara; Kumar, S. Balaji

2017-11-01

Equatorial Kelvin waves (KWs) are fundamental components of the tropical climate system. In this study, we investigate Kelvin waves (KWs) during the Hai-Tang typhoon of 2005 using Empirical Mode Decomposition (EMD) of regional precipitation, zonal and meridional winds. For the analysis, we use daily precipitation datasets from the Global Precipitation Climatology Project (GPCP) and wind datasets from the European Centre for Medium-Range Weather Forecasts (ECMWF) Interim Re-analysis (ERA-Interim). As an additional measurement, we use in-situ precipitation datasets from rain-gauges over the Taiwan region. The maximum accumulated precipitation was approximately 2400 mm during the period July 17-21, 2005 over the southwestern region of Taiwan. The spectral analysis using the wind speed at 950 hPa found in the 2nd, 3rd, and 4th intrinsic mode functions (IMFs) reveals prevailing Kelvin wave periods of ∼3 days, ∼4-6 days, and ∼6-10 days, respectively. From our analysis of precipitation datasets, we found the Kelvin waves oscillated with periods between ∼8 and 20 days.

Progress towards a new definition of the kelvin

Science.gov (United States)

Fischer, Joachim

2015-10-01

At its 24th meeting (2011) the General Conference on Weights and Measures noted the CIPM’s intention to express new definitions of the kilogram, ampere, kelvin, and mole in terms of fixed numerical values of the Planck constant, elementary charge, Boltzmann constant, and Avogadro constant, respectively. The changes proposed for the International System of Units will not actually be adopted until the experimental results on the new definitional constants that are proposed have reached a further stage of refinement. This paper provides an overview of the activities and progress of the research groups who are carrying out experiments to determine the Boltzmann constant. The most promising methods, acoustic gas thermometry, dielectric-constant gas thermometry, Johnson noise thermometry and Doppler-broadening thermometry, are reviewed. The prospects for meeting the requirements of the Consultative Committee for Thermometry for a new definition of the kelvin are discussed.

Noise performance of frequency modulation Kelvin force microscopy

Directory of Open Access Journals (Sweden)

Heinrich Diesinger

2014-01-01

Full Text Available Noise performance of a phase-locked loop (PLL based frequency modulation Kelvin force microscope (FM-KFM is assessed. Noise propagation is modeled step by step throughout the setup using both exact closed loop noise gains and an approximation known as “noise gain” from operational amplifier (OpAmp design that offers the advantage of decoupling the noise performance study from considerations of stability and ideal loop response. The bandwidth can be chosen depending on how much noise is acceptable and it is shown that stability is not an issue up to a limit that will be discussed. With thermal and detector noise as the only sources, both approaches yield PLL frequency noise expressions equal to the theoretical value for self-oscillating circuits and in agreement with measurement, demonstrating that the PLL components neither modify nor contribute noise. Kelvin output noise is then investigated by modeling the surrounding bias feedback loop. A design rule is proposed that allows choosing the AC modulation frequency for optimized sharing of the PLL bandwidth between Kelvin and topography loops. A crossover criterion determines as a function of bandwidth, temperature and probe parameters whether thermal or detector noise is the dominating noise source. Probe merit factors for both cases are then established, suggesting how to tackle noise performance by probe design. Typical merit factors of common probe types are compared. This comprehensive study is an encouraging step toward a more integral performance assessment and a remedy against focusing on single aspects and optimizing around randomly chosen key values.

Study on the KM capacitor base thermometers in the 42-273 K range

International Nuclear Information System (INIS)

Luzganov, V.S.; Mats'ko, A.A.

1988-01-01

Thermometric characteristics of the KM-5a-HZ0 monolithic capacitors in the 42-273 K temperature range are studied. Capacitors capacitance - temperature relation is considered in details. The data reproducibility after 5, 23, 34, 50, 51 and 57 days is studied, the accuracy of temperature measurements by the given thermometers is determined. Recommendations on selection of cpacitors, suitable for application as thermometer, are given. These capacitors permit temperature measurement in the 42-225 K range with the error of ± 0.5 K, and above 225 K the error is ± 1K. 8 refs.; 1 fig.; 1 tab

Effect of plasma density profile of tokamak on Kelvin-Helmholtz instability

International Nuclear Information System (INIS)

Tang Fulin

1984-01-01

The purpose of this paper is to study the effect of radial distribution of plasma density profile of tokamak on Kelvin-Helmholtz instability caused by toroidal rotation. The effect of radial distribution of plasma rotational velocity on stability is also examine for comparison. It is found that within the range of tokamak parameters the only radial distribution of plasma rotational velocity cannot induce Kelvin-Helmholtz instability. On the contrary, when there is a radial distribution of plasma density, i.e. P 01 =P 0 e -tx and V 0 1 = const, plasma becomes unstable, and instability will increase proportionally to the value of t. Meanwhile when the value of t remains constant, the instability growth rate will decrease if P 0 grows or the distance between plasma and wall of container decreases too. It shows that the Kelvin-Helmoltz instability is not only influenced by the steepness of density profile but also by the inertia of plasma in central region, which is helpful for depressing the instability. (author). 5 refs, 4 figs, 2 tabs

An electron beam linear scanning mode for industrial limited-angle nano-computed tomography

Science.gov (United States)

Wang, Chengxiang; Zeng, Li; Yu, Wei; Zhang, Lingli; Guo, Yumeng; Gong, Changcheng

2018-01-01

Nano-computed tomography (nano-CT), which utilizes X-rays to research the inner structure of some small objects and has been widely utilized in biomedical research, electronic technology, geology, material sciences, etc., is a high spatial resolution and non-destructive research technique. A traditional nano-CT scanning model with a very high mechanical precision and stability of object manipulator, which is difficult to reach when the scanned object is continuously rotated, is required for high resolution imaging. To reduce the scanning time and attain a stable and high resolution imaging in industrial non-destructive testing, we study an electron beam linear scanning mode of nano-CT system that can avoid mechanical vibration and object movement caused by the continuously rotated object. Furthermore, to further save the scanning time and study how small the scanning range could be considered with acceptable spatial resolution, an alternating iterative algorithm based on ℓ0 minimization is utilized to limited-angle nano-CT reconstruction problem with the electron beam linear scanning mode. The experimental results confirm the feasibility of the electron beam linear scanning mode of nano-CT system.

CZT nanoRAIDER_VFG Factsheet

Energy Technology Data Exchange (ETDEWEB)

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

2016-01-15

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

Rayleigh-Taylor and Kelvin-Helmholtz instabilities in targets accelerated by laser ablation

International Nuclear Information System (INIS)

Emery, M.H.; Gardner, J.H.; Boris, J.P.

1982-01-01

With use of the fast2d laser-shell model, the acceleration of a 20-μm-thick plastic foil up to 160 km/s has been simulated. It is possible to follow the Rayleigh-Taylor bubble-and-spike development far into the nonlinear regime and beyond the point of foil fragmentation. Strong shear flow develops which evolves into the Kelvin-Helmholtz instability. The Kelvin-Helmholtz instability causes the tips of the spikes to widen and as a result reduce their rate of ''fall.''

Operational methods of thermodynamics. Volume 1 - Temperature measurement

Science.gov (United States)

Eder, F. X.

The principles of thermometry are examined, taking into account the concept of temperature, the Kelvin scale, the statistical theory of heat, negative absolute temperatures, the thermodynamic temperature scale, the thermodynamic temperature scale below 1 K, noise thermometry, temperature scales based on black-body radiation, acoustical thermometry, and the International Practical Temperature Scale 1968. Aspects of practical temperature measurement are discussed, giving attention to thermometers based on the expansion of a gas or a liquid, instruments utilizing the relative thermal expansion of two different metals, devices measuring the vapor pressure of a liquid, thermocouples, resistance thermometers, radiation pyrometers of various types, instruments utilizing the temperature dependence of a number of material characteristics, devices for temperature control, thermometer calibration, and aspects of thermometer installation and inertia. A description is presented of the approaches employed for the measurement of low temperatures.

Nano features of Al/Au ultrasonic bond interface observed by high resolution transmission electron microscopy

International Nuclear Information System (INIS)

Ji Hongjun; Li Mingyu; Kim, Jong-Myung; Kim, Dae-Won; Wang Chunqing

2008-01-01

Nano-scale interfacial details of ultrasonic AlSi1 wire wedge bonding to a Au/Ni/Cu pad were investigated using high resolution transmission electron microscopy (HRTEM). The intermetallic phase Au 8 Al 3 formed locally due to diffusion and reaction activated by ultrasound at the Al/Au bond interface. Multilayer sub-interfaces roughly parallel to the wire/pad interface were observed among this phase, and interdiffusional features near the Au pad resembled interference patterns, alternately dark and bright bars. Solid-state diffusion theory cannot be used to explain why such a thick compound formed within milliseconds at room temperature. The major formation of metallurgical bonds was attributed to ultrasonic cyclic vibration

Evaluation of a Teaching Kit for Family and Consumer Science Classrooms: Motivating Students to Use a Food Thermometer with Small Cuts of Meat

Science.gov (United States)

Edwards, Zena; Edlefsen, Miriam; Hillers, Virginia; McCurdy, Sandra M.

2005-01-01

The U.S. Dept. of Agriculture recommends use of food thermometers to safely cook small cuts of meat, yet most consumers do not use them. Consumers lack knowledge about how and why to use food thermometers with small cuts of meat. Opportunities exist for family and consumer science classes to provide education about thermometers to adolescents, who…

Observations of Convectively Coupled Kelvin Waves forced by Extratropical Wave Activity

Science.gov (United States)

Kiladis, G. N.; Biello, J. A.; Straub, K. H.

2012-12-01

It is well established by observations that deep tropical convection can in certain situations be forced by extratropical Rossby wave activity. Such interactions are a well-known feature of regions of upper level westerly flow, and in particular where westerlies and equatorward wave guiding by the basic state occur at low enough latitudes to interact with tropical and subtropical moisture sources. In these regions convection is commonly initiated ahead of upper level troughs, characteristic of forcing by quasi-geostrophic dynamics. However, recent observational evidence indicates that extratropical wave activity is also associated with equatorial convection even in regions where there is a "critical line" to Rossby wave propagation at upper levels, that is, where the zonal phase speed of the wave is equal to the zonal flow speed. A common manifestation of this type of interaction involves the initiation of convectively coupled Kelvin waves, as well as mixed Rossby-gravity (MRG) waves. These waves are responsible for a large portion of the convective variability within the ITCZ over the Indian, Pacific, and Atlantic sectors, as well as within the Amazon Basin of South America. For example, Kelvin waves originating within the western Pacific ITCZ are often triggered by Rossby wave activity propagating into the Australasian region from the South Indian Ocean extratropics. At other times, Kelvin waves are seen to originate along the eastern slope of the Andes. In the latter case the initial forcing is sometimes linked to a low-level "pressure surge," initiated by wave activity propagating equatorward from the South Pacific storm track. In yet other cases, such as over Africa, the forcing appears to be related to wave activity in the extratropics which is not necessarily propagating into low latitudes, but appears to "project" onto the Kelvin structure, in line with past theoretical and modeling studies. Observational evidence for extratropical forcing of Kelvin and MRG

A massive cryogenic particle detector with good energy resolution

International Nuclear Information System (INIS)

Ferger, P.; Colling, P.; Cooper, S.; Dummer, D.; Frank, M.; Nagel, U.; Nucciotti, A.; Proebst, F.; Seidel, W.

1993-12-01

Massive cryogenic particle detectors are being developed for use in a search for dark matter particles. Results with a 31 g sapphire crystal and a superconducting phase transition thermometer operated at 44 mK are presented. The observed signal includes a fast component which is significantly larger than the expected thermal pulse. The energy resolution is 210 eV (FWHM) for 6 keV X-rays. (orig.)

KELVIN rare gas time-of-flight program

International Nuclear Information System (INIS)

Vernon, M.

1981-03-01

The purpose of this appendix is to explain in detail the procedure for performing time-of-flight (TOF) calibration measurements. The result of the calibration measurements is to assign a correct length (L) to the path the molecules travel in a particular experimental configuration. In conjunction with time information (t) a velocity distribution (L/t) can then be determined. The program KELVIN is listed

Preliminary Results on New Prototypes of Precision Rh-0.5at%Fe Resistance Thermometers of Chinese Production

Science.gov (United States)

Pavese, F.; Szmyrka-Grzebyk, A.; Lipinski, L.; Manuszkiewicz, H.; Qiu, Ping; Zhang, Jin Tao; Lin, Peng; Li, Xing Wei

2008-02-01

Given the practical impossibility of obtaining new precision Rh-0.5at%Fe resistance thermometers in recent years, the possible re-starting of the production of such thermometers in Yunnan (China) was explored by Istituto Nazionale di Ricerca Metrologica (INRIM). Ten prototypes of the new production were made available in early 2006. The paper reports the preliminary data from the testing performed to date on these prototypes at National Institute of Metrology (NIM) and Instytut Niskich Temperatur i Badan Strukturalnych (INTiBS). Although a problem with the alloy composition was detected, the reproducibility results on thermal cycling are very encouraging. Resistance-temperature ( R- T) characteristics below 30 K, though not identical with those of similar thermometers formerly available from Tinsley and VNIIFTRI, are still suitable for accurate metrology.

The Kelvin-Thomson atom

International Nuclear Information System (INIS)

Walton, A.J.

1977-01-01

The contributions made by Kelvin and later by J.J. Thomson to the 'current-bun' model of the atom are discussed. It is felt that the model is worth retaining as a didactic aid since it serves as a good example around which to hang a discussion of modelling as well as providing good examples of the application of Coulomb's and Gauss's laws. The structure of atoms containing up to six electrons is examined using an analysis based on this model. It is shown that it is possible to have a mechanically stable arrangement of up to six electrons located within a sphere of uniform positive charge. With up to three electrons the arrangement is coplanar with the centre of the sphere. (U.K.)

A gas thermometer for vapor pressure measurements

Science.gov (United States)

Rusin, A. D.

2008-08-01

The pressure of an inert gas over the range 400 1000 K was measured on a tensimetric unit with a quartz membrane pressure gauge of enhanced sensitivity. It was shown that a reactor with a membrane null gauge could be used as a gas thermometer. The experimental confidence pressure and temperature intervals were 0.07 torr and 0.1 K at a significance level of 0.05. A Pt-Pt/10% Rh thermocouple was calibrated; the results were approximated by a polynomial of degree five. The error in temperature calculations was 0.25 K.

Ultrasensitive thermometer for atmospheric pressure operation based on a micromechanical resonator

DEFF Research Database (Denmark)

Cagliani, Alberto; Pini, V.; Tamayo, J.

2014-01-01

For highly integrated systems for bio and chemical analysis a precise and integrated measurement of temperature is of fundamental importance. We have developed an ultrasensitive thermometer based on a micromechanical resonator for operation in air. The high quality factor and the strong temperatu...

Kelvin-Helmholtz Instability: Lessons Learned and Ways Forward

Science.gov (United States)

Masson, A.; Nykyri, K.

2018-06-01

The Kelvin-Helmholtz instability (KHI) is a ubiquitous phenomenon across the Universe, observed from 500 m deep in the oceans on Earth to the Orion molecular cloud. Over the past two decades, several space missions have enabled a leap forward in our understanding of this phenomenon at the Earth's magnetopause. Key results obtained by these missions are first presented, with a special emphasis on Cluster and THEMIS. In particular, as an ideal instability, the KHI was not expected to produce mass transport. Simulations, later confirmed by spacecraft observations, indicate that plasma transport in Kelvin-Helmholtz (KH) vortices can arise during non-linear stage of its development via secondary process. In addition to plasma transport, spacecraft observations have revealed that KHI can also lead to significant ion heating due to enhanced ion-scale wave activity driven by the KHI. Finally, we describe what are the upcoming observational opportunities in 2018-2020, thanks to a unique constellation of multi-spacecraft missions including: MMS, Cluster, THEMIS, Van Allen Probes and Swarm.

Thermodynamics and historical relevance of a jetting thermometer made of Chinese zisha ceramic

Science.gov (United States)

Lee, Vincent; Attinger, Daniel

2016-07-01

Following a recent trend of scientific studies on artwork, we study here the thermodynamics of a thermometer made of zisha ceramic, related to the Chinese tea culture. The thermometer represents a boy who “urinates” shortly after hot water is poured onto his head. Long jetting distance is said to indicate that the water temperature is hot enough to brew tea. Here, a thermodynamic model describes the jetting phenomenon of that pee-pee boy. The study demonstrates how thermal expansion of an interior air pocket causes jetting. A thermodynamic potential is shown to define maximum jetting velocity. Seven optimization criteria to maximize jetting distance are provided, including two dimensionless numbers. Predicted jetting distances, jet durations, and temperatures agree very well with infrared and optical measurements. Specifically, the study confirms that jetting distances are sensitive enough to measure water temperature in the context of tea brewing. Optimization results show that longer jets are produced by large individuals, with low body mass index, with a boyhood of medium size inclined at an angle π/4. The study ends by considering the possibility that ceramic jetting artifacts like the pee-pee boy might have been the first thermometers known to mankind, before Galileo Galilei’s thermoscope.

Kelvin Equation for a Non-Ideal Multicomponent Mixture

DEFF Research Database (Denmark)

Shapiro, Alexander; Stenby, Erling Halfdan

1997-01-01

The Kelvin equation is generalized by application to a case of a multicomponent non-ideal mixture. Such a generalization is necessary in order to describe the two-phase equilibrium in a capillary medium with respect to both normal and retrograde condensation. The equation obtained is applied...... to the equilibrium state of a hydrocarbon mixture ina gas-condensate reservoir....

Evaluation of the Use of Optical Fiber Thermometers for Thermal Control of the Quench Module Insert

Science.gov (United States)

Jones, Matthew R.; Farmer, Jeffrey T.; Breeding, Shawn P.

2001-01-01

Issues regarding the use of optical fiber thermometers to control heater settings in a microgravity vacuum furnace are addressed. It is desirable to use these probes in environments such as the International Space Station, because they can be operated without re-calibration for extended periods. However, the analysis presented in this paper shows that temperature readings obtained using optical fiber thermometers can be corrupted by emissions from the fiber when extended portions of the probe are exposed to elevated temperatures.

Use of infrared radiation thermometers for temperature control of plastic and paper webs in electric infrared ovens

International Nuclear Information System (INIS)

Jacobson, D.A.

1985-01-01

Using infrared radiation thermometers in conjunction with infrared heater systems requires special considerations to ensure that accuracy will be achieved. If the thermometer picks up infrared radiation from the heaters, faulty readings can occur. Two methods are generally employed to eliminate this interference. Sight tubes are used to block infrared rays from entering the sensor lens, and a thermometer is chosen which responds to a different wavelength than that being emitted from the infrared heaters. The main types of electric infrared heaters are: (a) screw-in bulbs (shortwave); (b) evacuated tungsten filament tubes (shortwave); (c) quartz tubes (medium wave); (d) quartz panel heaters (medium wave); (e) Ceramic heaters (medium-long wave); (f) metal sheath heaters (medium-long wave). Positioning of a sensor on a production line is dictated by the product being processed and the desired use of the temperature information. The most common location for a sensor is just after the infrared unit. The pyrometer information can be used for setting up the process, for quality control, for heater failure detection, and for control of the heaters. For wide web application in which uniformity across the web is essential, traversing sensors can be used to scan the web to ensure a uniform heating of the product. This information then can be used to control infrared profiling zones which are positioned across the web. In plastics applications, the thermometer most commonly is positioned also at the exit end of the infrared unit. Control functions are similar to those just listed. In some indexing machines, the plastic is sensed while still in the last index station, and the index an be initiated by the thermometer

Pressure-driven ballistic Kelvin's water dropper for energy harvesting

NARCIS (Netherlands)

Xie, Yanbo; de Boer, Hans L.; van den Berg, Albert; Sprenkels, A.J.; Eijkel, Jan C.T.

2014-01-01

In this paper, we introduce a microfluidic-based self-excited energy conversion system inspired by Kelvin's water dropper but driven by inertia instead of gravity. Two micro water jets are produced by forcing water through two micropores by overpressure. The jets break up into microdroplets which

Nano-DTA and nano-DSC with cantilever-type calorimeter

International Nuclear Information System (INIS)

Nakabeppu, Osamu; Deno, Kohei

2016-01-01

Highlights: • Nanocalorimetry with original cantilever type calorimeters. • The calorimeters showed the enthalpy resolution of 200 nJ level. • Nano-DTA of a binary alloy captured a probabilistic peak after solidification. • Power compensation DSC of a microgram level sample was demonstrated. • The DSC and DTA behavior were explained with a lumped model. - Abstract: Differential thermal analysis (DTA) and differential scanning calorimetry (DSC) of the minute samples in the range of microgram to nanogram were studied using original cantilever-type calorimeters. The micro-fabricated calorimeter with a heater and thermal sensors was able to perform a fast temperature scan at above 1000 K/s and a high-resolution heat measurement. The DTA of minuscule metal samples demonstrated some advances such as the thermal analysis of a 20 ng level indium and observation of a strange phase transition of a binary alloy. The power compensation type DSC using a thermal feedback system was also performed. Thermal information of a microgram level sample was observed as splitting into the DSC and DTA signals because of a mismatch between the sample and the calorimeter. Although there remains some room for improvement in terms of the heat flow detection, the behavior of the compensation system in the DSC was theoretically understood through a lumped model. Those experiments also produced some findings, such as a fin effect with sample loading, a measurable weight range, a calibration of the calorimeter and a product design concept. The development of the nano-DTA and nano-DSC will enable breakthroughs for the fast calorimetry of the microscopic size samples.

Numerical Prediction of Wave Patterns Due to Motion of 3D Bodies by Kelvin-Havelock Sources

Directory of Open Access Journals (Sweden)

Ghassemi Hassan

2016-12-01

Full Text Available This paper discusses the numerical evaluation of the hydrodynamic characteristics of submerged and surface piercing moving bodies. Generally, two main classes of potential methods are used for hydrodynamic characteristic analysis of steady moving bodies which are Rankine and Kelvin-Havelock singularity distribution. In this paper, the Kelvin- Havelock sources are used for simulating the moving bodies and then free surface wave patterns are obtained. Numerical evaluation of potential distribution of a Kelvin-Havelock source is completely presented and discussed. Numerical results are calculated and presented for a 2D cylinder, single source, two parallel moving source, sphere, ellipsoid and standard Wigley hull in different situation that show acceptable agreement with results of other literatures or experiments.

Vertical propagation of baroclinic Kelvin waves along the west coast ...

Indian Academy of Sciences (India)

Second, baroclinic Kelvin waves generated in the Bay of Bengal at periods shorter than about 120 ... significant energy remains trapped to the Indian west coast. .... ary condition, enables us to isolate the response of the West India Coastal ...

Magnetized Kelvin-Helmholtz instability: theory and simulations in the Earth's magnetosphere context

Science.gov (United States)

Faganello, Matteo; Califano, Francesco

2017-12-01

The Kelvin-Helmholtz instability, proposed a long time ago for its role in and impact on the transport properties at magnetospheric flanks, has been widely investigated in the Earth's magnetosphere context. This review covers more than fifty years of theoretical and numerical efforts in investigating the evolution of Kelvin-Helmholtz vortices and how the rich nonlinear dynamics they drive allow solar wind plasma bubbles to enter into the magnetosphere. Special care is devoted to pointing out the main advantages and weak points of the different plasma models that can be adopted for describing the collisionless magnetospheric medium and in underlying the important role of the three-dimensional geometry of the system.

Equatorial atmospheric Kelvin waves during El Niño episodes and their effect on stratospheric QBO

International Nuclear Information System (INIS)

Das, Uma; Pan, C.J.

2016-01-01

Equatorial atmospheric Kelvin waves are investigated during a positive El Niño Southern Oscillation (ENSO) episode using temperature data retrieved from GPS Radio Occultation (RO) observations of FORMOSAT-3/COSMIC during the period from August 2006 to December 2013. Enhanced Kelvin wave amplitudes are observed during the El Niño episode of 2009–2010 and it is also observed that these amplitudes correlate with the Niño 3.4 index and also with outgoing longwave radiation and trade wind index. This study indicates that the enhanced equatorial atmospheric Kelvin wave amplitudes might be produced by geophysical processes that were involved in the onset and development of the El Niño episode. Further, easterly winds above the tropopause during this period favored the vertically upward propagation of these waves that induced a fast descending westerly regime by the end of 2010, where the zero-wind line is observed to take only 5 months to descend from 10 to 50 hPa. The current study presents observational evidence of enhanced Kelvin wave amplitudes during El Niño that has affected the stratospheric quasi-biennial oscillation (QBO) through wave–mean flow interactions. Earlier El Niño episodes of 1987 and 1998 are also qualitatively investigated, using reanalysis data. It is found that there might have been an enhancement in the equatorial Kelvin wave amplitudes during almost all El Niño episodes, however, an effect of a fast descending westerly is observed in the QBO only when the ambient zonal winds in the lower stratosphere favor the upward propagation of the Kelvin waves and consequently they interact with the mean flow. This study indicates that the El Niño and QBO are not linearly related and wave mean flow interactions play a very important role in connecting these two geophysical phenomena. - Highlights: • Enhanced atmospheric Kelvin Wave amplitudes observed during El Nino of 2010. • The waves are probably produced by processes generating El Nino. �

Equatorial atmospheric Kelvin waves during El Niño episodes and their effect on stratospheric QBO

Energy Technology Data Exchange (ETDEWEB)

Das, Uma [Department of Physics, University of New Brunswick, Fredericton (Canada); Pan, C.J., E-mail: cjpan@jupiter.ss.ncu.edu.tw [Institute of Space Science, National Central University, Jhongli, Taiwan (China)

2016-02-15

Equatorial atmospheric Kelvin waves are investigated during a positive El Niño Southern Oscillation (ENSO) episode using temperature data retrieved from GPS Radio Occultation (RO) observations of FORMOSAT-3/COSMIC during the period from August 2006 to December 2013. Enhanced Kelvin wave amplitudes are observed during the El Niño episode of 2009–2010 and it is also observed that these amplitudes correlate with the Niño 3.4 index and also with outgoing longwave radiation and trade wind index. This study indicates that the enhanced equatorial atmospheric Kelvin wave amplitudes might be produced by geophysical processes that were involved in the onset and development of the El Niño episode. Further, easterly winds above the tropopause during this period favored the vertically upward propagation of these waves that induced a fast descending westerly regime by the end of 2010, where the zero-wind line is observed to take only 5 months to descend from 10 to 50 hPa. The current study presents observational evidence of enhanced Kelvin wave amplitudes during El Niño that has affected the stratospheric quasi-biennial oscillation (QBO) through wave–mean flow interactions. Earlier El Niño episodes of 1987 and 1998 are also qualitatively investigated, using reanalysis data. It is found that there might have been an enhancement in the equatorial Kelvin wave amplitudes during almost all El Niño episodes, however, an effect of a fast descending westerly is observed in the QBO only when the ambient zonal winds in the lower stratosphere favor the upward propagation of the Kelvin waves and consequently they interact with the mean flow. This study indicates that the El Niño and QBO are not linearly related and wave mean flow interactions play a very important role in connecting these two geophysical phenomena. - Highlights: • Enhanced atmospheric Kelvin Wave amplitudes observed during El Nino of 2010. • The waves are probably produced by processes generating El Nino. �

Variations of Kelvin waves around the TTL region during the stratospheric sudden warming events in the Northern Hemisphere winter

Directory of Open Access Journals (Sweden)

Y. Jia

2016-03-01

Full Text Available Spatial and temporal variabilities of Kelvin waves during stratospheric sudden warming (SSW events are investigated by the ERA-Interim reanalysis data, and the results are validated by the COSMIC temperature data. A case study on an exceptionally large SSW event in 2009, and a composite analysis comprising 18 events from 1980 to 2013 are presented. During SSW events, the average temperature increases by 20 K in the polar stratosphere, while the temperature in the tropical stratosphere decreases by about 4 K. Kelvin wave with wave numbers 1 and 2, and periods 10–20 days, clearly appear around the tropical tropopause layer (TTL during SSWs. The Kelvin wave activity shows obvious coupling with the convection localized in the India Ocean and western Pacific (Indo-Pacific region. Detailed analysis suggests that the enhanced meridional circulation driven by the extratropical planetary wave forcing during SSW events leads to tropical upwelling, which further produces temperature decrease in the tropical stratosphere. The tropical upwelling and cooling consequently result in enhancement of convection in the equatorial region, which excites the strong Kelvin wave activity. In addition, we investigated the Kelvin wave acceleration to the eastward zonal wind anomalies in the equatorial stratosphere during SSW events. The composite analysis shows that the proportion of Kelvin wave contribution ranges from 5 to 35 % during SSWs, much larger than in the non-SSW mid-winters (less than 5 % in the stratosphere. However, the Kelvin wave alone is insufficient to drive the equatorial eastward zonal wind anomalies during the SSW events, which suggests that the effects of other types of equatorial waves may not be neglected.

Detection of the fast Kelvin wave teleconnection due to El Niño-Southern Oscillation

Science.gov (United States)

Meyers, Steven D.; Melsom, Arne; Mitchum, Gary T.; O'Brien, James J.

1998-11-01

Previous analyses of the ocean state along the western American coast have often indicated unexpectedly slow and limited propagation of coastally trapped Kelvin waves associated with the El Niño-Southern Oscillation. In contrast, theoretical and numerical ocean models demonstrate that these Kelvin waves are a rapid and long-range teleconnection between the low- and high-latitude Pacific Ocean, strongly impacting both the surface coastal currents and nutrient upwelling. Sea level variations along the western coast of North America are reexamined under the assumption that tropically forced Kelvin waves are produced in bursts of several months duration. A cross-correlation analysis, restricted to mid-1982 to mid-1983, is performed between Galapagos Island and stations along western Central and North America. A coastally trapped Kelvin wave is revealed to propagate at a speed of 2-3 m s-1 from the tropical Pacific to the Aleutian Island Chain. The observed phase speed agrees with the estimated speed of a Kelvin wave based on the average density profile of the ocean near the coast. Weaker El Niño events in 1986/1987 and 1991/1992 appear to contain a combination of this remote signal and local wind forcing. The wave propagation speed calculated from the spectral phase is shown to be sensitive to the presence of other (noise) processes in the observations. This is demonstrated through an analysis of a synthetic sea level data set that contains many of the essential features of the real sea level data. A relatively small level of red noise can give a 100% expected error in the estimated propagation speed. This suggests a new explanation for this important inconsistency within dynamical oceanography.

Application of kinetic inductance thermometers to x-ray calorimetry

International Nuclear Information System (INIS)

Wai, Y.C.; Labov, S.E.; Silver, E.H.

1990-01-01

A kinetic inductance thermometer is applied to x-ray calorimetry, and its operation over a wide range of frequencies and geometries is discussed. Three amplifier configurations are described, one using a superconducting quantum interference device (SQUID) amplifier, another incorporating an FET amplifier in an amplitude modulated system, and the third, using a tunnel diode frequency modulated oscillator circuit. The predicted performance of each configuration is presented. 13 refs., 6 figs., 1 tab

Mechanic-electrical transformations in the Kelvin method

Energy Technology Data Exchange (ETDEWEB)

Zharkikh, Yu. S., E-mail: yurzhar@gmail.com [Faculty of Radio Physics, Electronics and Computer Systems, Taras Shevchenko National University of Kyiv, 4G, Ave. Academician Glushkov, 03127, Kyiv (Ukraine); Lysochenko, S.V., E-mail: lys@univ.kiev.ua [Institute of High Technologies, Taras Shevchenko National University of Kyiv, 4G, Ave. Academician Glushkov, 03127, Kyiv (Ukraine)

2017-04-01

Highlights: • Used in Kelvin method dynamic capacitor is a mechanic-electrical transformer. • The oscillations of its plate are source of extraneous forces which cause the appearance of an electric current. • The signal is caused not by the contact potential difference, but by oscillation in the screening conditions of charge in the dynamic capacitor gap. • Combining the Kelvin method with electron emission methods to determine the work function may lead to incorrectness. - Abstract: To explain the initiation mechanism of alternating current in an electric circuit containing the dynamic capacitor a model of mechanic- electrical transformation is suggested to use. In such a model, electric charges disposed between the capacitor plates serve as a cause of measured signal in contrast to the contact potential difference, which is considered as the main base in the Kelvin’s model. If one of the plates moves periodically, then the conditions of the charges screening are changed and thereby the capacitor recharging current is arise. The measuring is based on compensation of the recharging current by current, which generated by a source of electromotive force (EMF). The compensation voltage depends on both the distribution of ions or dipoles over the studied surface and the charges creating the surface potential barrier. This voltage is independent on the bulk electro-physical characteristics of a solid.

Optical Fiber Thermometer Based on Fiber Bragg Gratings

Science.gov (United States)

Rosli, Ekbal Bin; Mohd. Noor, Uzer

2018-03-01

Fiber Bragg grating has generated much interest in use as sensors to measure strain, temperature, and other physical parameters. It also the most common component used to develop this sensor with the advantages of simple, intrinsic sensing elements, electrically passive operation, EMI immunity, high sensitivity, compact size and potentially low cost [6]. This paper reports the design of an optical fiber thermometer based on fiber Bragg gratings. The system was developed for detecting temperature and strain by monitoring the shift of Bragg wavelength. The shifting of Bragg wavelength is used to indicate the temperature and strain due to the change in the surrounding temperature and strain. When the temperature and strain reach the exact wavelength level of the system, the temperature and strain value will display on the Arduino liquid crystal display (LCD). The optical fiber will provide the broadband light source and after passing the FBG the Bragg wavelength into the optical spectrum analyzer (OSA). The system is based on FBG as a physical quantity sensor. The temperatures measured is taken from the water bath and that of the strain is provided by amount of slotted mass used. The outcome of this project is to characterize the Bragg wavelength shifting from the fiber Bragg grating output. As the conclusion, this project provides an efficient optical fiber thermometer in measuring temperature and strain in order to replace the use of conventional electrical instruments.

The Evolution of the Celsius and Kelvin Temperature Scales and the State of the Art

Science.gov (United States)

Pellicer, Julio; Amparo Gilabert, M.; Lopez-Baeza, Ernesto

1999-07-01

A physical analysis is given of the evolution undergone by the Celsius and Kelvin temperature scales, from their definition to the present day. It is shown that in the temperature interval between the melting point of ice and the boiling point of water, the Celsius and Kelvin scales, both born centigrade by definition and actually become so afterwards by experimental determination as well, are not so any longer, either by definition or by experimental determination.

Coupled Kelvin-Helmholtz and Tearing Mode Instabilities at the Mercury's Magnetopause

Science.gov (United States)

Ivanovski, S. L.; Milillo, A.; Kartalev, M.; Massetti, S.

2018-05-01

A MHD approach for numerical simulations of coupled Kelvin-Helmholtz and tearing mode instabilities has been applied to Mercury’s magnetopause and used to perform a physical parameters study constrained by the MESSENGER data.

Nanosar-case study of synthetic aperture radar for nano-satellites

NARCIS (Netherlands)

Engelen, S.; Oever, M. van den; Mahapatra, P.; Sundaramoorthy, P.; Gill, E.; Meijer, R.J.; Verhoeven, C.

2012-01-01

Nano-satellites have a cost advantage due to their low mass and usage of commercial-off-the-shelf technologies. However, the low mass also restricts the functionality of a nano-satellite's payload. Typically, this would imply instruments with very low to low resolution and accuracy, essentially

Time-Efficient High-Resolution Large-Area Nano-Patterning of Silicon Dioxide

Directory of Open Access Journals (Sweden)

Li Lin

2017-01-01

Full Text Available A nano-patterning approach on silicon dioxide (SiO2 material, which could be used for the selective growth of III-V nanowires in photovoltaic applications, is demonstrated. In this process, a silicon (Si stamp with nanopillar structures was first fabricated using electron-beam lithography (EBL followed by a dry etching process. Afterwards, the Si stamp was employed in nanoimprint lithography (NIL assisted with a dry etching process to produce nanoholes on the SiO2 layer. The demonstrated approach has advantages such as a high resolution in nanoscale by EBL and good reproducibility by NIL. In addition, high time efficiency can be realized by one-spot electron-beam exposure in the EBL process combined with NIL for mass production. Furthermore, the one-spot exposure enables the scalability of the nanostructures for different application requirements by tuning only the exposure dose. The size variation of the nanostructures resulting from exposure parameters in EBL, the pattern transfer during nanoimprint in NIL, and subsequent etching processes of SiO2 were also studied quantitatively. By this method, a hexagonal arranged hole array in SiO2 with a hole diameter ranging from 45 to 75 nm and a pitch of 600 nm was demonstrated on a four-inch wafer.

Reexamining age, race, site, and thermometer type as variables affecting temperature measurement in adults – A comparison study

Directory of Open Access Journals (Sweden)

Smith Linda S

2003-06-01

Full Text Available Abstract Background As a result of the recent international vigilance regarding disease assessment, accurate measurement of body temperature has become increasingly important. Yet, trusted low-tech, portable mercury glass thermometers are no longer available. Thus, comparing accuracy of mercury-free thermometers with mercury devices is essential. Study purposes were 1 to examine age, race, site as variables affecting temperature measurement in adults, and 2 to compare clinical accuracy of low-tech Galinstan-in-glass device to mercury-in-glass at oral, axillary, groin, and rectal sites in adults. Methods Setting 176 bed accredited healthcare facility, rural northwest US Participants Convenience sample (N = 120 of hospitalized persons ≥ 18 years old. Instruments Temperatures (°F measured at oral, skin (simultaneous, immediately followed by rectal sites with four each mercury-glass (BD and Galinstan-glass (Geratherm thermometers; 10 minute dwell times. Results Participants averaged 61.6 years (SD 17.9, 188 pounds (SD 55.3; 61% female; race: 85% White, 8.3% Native Am., 4.2% Hispanic, 1.7 % Asian, 0.8% Black. For both mercury and Galinstan-glass thermometers, within-subject temperature readings were highest rectally; followed by oral, then skin sites. Galinstan assessments demonstrated rectal sites 0.91°F > oral and ≅ 1.3°F > skin sites. Devices strongly correlated between and across sites. Site difference scores between devices showed greatest variability at skin sites; least at rectal site. 95% confidence intervals of difference scores by site (°F: oral (0.142 – 0.265, axilla (0.167 – 0.339, groin (0.037 – 0.321, and rectal (-0.111 – 0.111. Race correlated with age, temperature readings each site and device. Conclusion Temperature readings varied by age, race. Mercury readings correlated with Galinstan thermometer readings at all sites. Site mean differences between devices were considered clinically insignificant. Still considered

Super-resolution for asymmetric resolution of FIB-SEM 3D imaging using AI with deep learning.

Science.gov (United States)

Hagita, Katsumi; Higuchi, Takeshi; Jinnai, Hiroshi

2018-04-12

Scanning electron microscopy equipped with a focused ion beam (FIB-SEM) is a promising three-dimensional (3D) imaging technique for nano- and meso-scale morphologies. In FIB-SEM, the specimen surface is stripped by an ion beam and imaged by an SEM installed orthogonally to the FIB. The lateral resolution is governed by the SEM, while the depth resolution, i.e., the FIB milling direction, is determined by the thickness of the stripped thin layer. In most cases, the lateral resolution is superior to the depth resolution; hence, asymmetric resolution is generated in the 3D image. Here, we propose a new approach based on an image-processing or deep-learning-based method for super-resolution of 3D images with such asymmetric resolution, so as to restore the depth resolution to achieve symmetric resolution. The deep-learning-based method learns from high-resolution sub-images obtained via SEM and recovers low-resolution sub-images parallel to the FIB milling direction. The 3D morphologies of polymeric nano-composites are used as test images, which are subjected to the deep-learning-based method as well as conventional methods. We find that the former yields superior restoration, particularly as the asymmetric resolution is increased. Our super-resolution approach for images having asymmetric resolution enables observation time reduction.

Assessing the accuracy of globe thermometer method in predicting outdoor mean radiant temperature under Malaysia tropical microclimate

Science.gov (United States)

Khrit, N. G.; Alghoul, M. A.; Sopian, K.; Lahimer, A. A.; Elayeb, O. K.

2017-11-01

Assessing outdoor human thermal comfort and urban climate quality require experimental investigation of microclimatic conditions and their variations in open urban spaces. For this, it is essential to provide quantitative information on air temperature, humidity, wind velocity and mean radiant temperature. These parameters can be quantified directly except mean radiant temperature (Tmrt). The most accurate method to quantify Tmrt is integral radiation measurements (3-D shortwave and long-wave) which require using expensive radiometer instruments. To overcome this limitation the well-known globe thermometer method was suggested to calculate Tmrt. The aim of this study was to assess the possibility of using indoor globe thermometer method in predicting outdoor mean radiant temperature under Malaysia tropical microclimate. Globe thermometer method using small and large sizes of black-painted copper globes (50mm, 150mm) were used to estimate Tmrt and compare it with the reference Tmrt estimated by integral radiation method. The results revealed that the globe thermometer method considerably overestimated Tmrt during the middle of the day and slightly underestimated it in the morning and late evening. The difference between the two methods was obvious when the amount of incoming solar radiation was high. The results also showed that the effect of globe size on the estimated Tmrt is mostly small. Though, the estimated Tmrt by the small globe showed a relatively large amount of scattering caused by rapid changes in radiation and wind speed.

In situ calibration of nuclear plant resistance thermometers using Johnson noise. Draft

International Nuclear Information System (INIS)

Blalock, T.V.; Roberts, M.J.; Shepard, R.L.

1984-01-01

Methods have been demonstrated in operating nuclear plants for the in situ calibration of resistance thermometers with agreement between measured noise temperatures and dc calibration temperatures well within these required by the plant. A comparison of the results of Johnson noise power testing results and uncertainties, the requirements for accuracy, and PRT calibration tolerances is shown. The methods use Johnson noise measurements and provide an absolute calibration independent of the prior dc calibration. The methods include techniques for characterization of the installed extension cables and the quantitative determination of induced EMI and its effect on the calibration. The techniques are applicable to ordinary 4-wire platinum resistance thermometers operating over their entire design temperature range and to extension cables of about 100 ft length. Careful attention needs to be paid to the choice or cables, location of terminal boxes, and grounding and shielding practices in the plant installation to achieve comparable results

Can Hall effect trigger Kelvin-Helmholtz instability in sub-Alfvénic flows?

Science.gov (United States)

Pandey, B. P.

2018-05-01

In the Hall magnetohydrodynamics, the onset condition of the Kelvin-Helmholtz instability is solely determined by the Hall effect and is independent of the nature of shear flows. In addition, the physical mechanism behind the super- and sub-Alfvénic flows becoming unstable is quite different: the high-frequency right circularly polarized whistler becomes unstable in the super-Alfvénic flows whereas low-frequency, left circularly polarized ion-cyclotron wave becomes unstable in the presence of sub-Alfvénic shear flows. The growth rate of the Kelvin-Helmholtz instability in the super-Alfvénic case is higher than the corresponding ideal magnetohydrodynamic rate. In the sub-Alfvénic case, the Hall effect opens up a new, hitherto inaccessible (to the magnetohydrodynamics) channel through which the partially or fully ionized fluid can become Kelvin-Helmholtz unstable. The instability growth rate in this case is smaller than the super-Alfvénic case owing to the smaller free shear energy content of the flow. When the Hall term is somewhat smaller than the advection term in the induction equation, the Hall effect is also responsible for the appearance of a new overstable mode whose growth rate is smaller than the purely growing Kelvin-Helmholtz mode. On the other hand, when the Hall diffusion dominates the advection term, the growth rate of the instability depends only on the Alfvén -Mach number and is independent of the Hall diffusion coefficient. Further, the growth rate in this case linearly increases with the Alfvén frequency with smaller slope for sub-Alfvénic flows.

Zero Kelvin Big Bang, an Alternative Paradigm: I. Logic and the Cosmic Fabric

Science.gov (United States)

Haynes, Royce

2011-11-01

This is the first of three papers describing an alternative paradigm of cosmogony, the beginning and evolution of the universe. The Zero Kelvin Big Bang (ZKBB) theory is compared to the prevailing Standard Big Bang (SBB) paradigm, and challenges the notion that our universe is "all there is." Logic suggests that the Big Bang was not a creation event, but that the universe did have a beginning: a "cosmic fabric" of pre- existing matter, in pre-existing space. Instead, the Zero Kelvin Big Bang was a transitional event between that "beginning" and what would become our universe. Extrapolating entropy back in time (as SBB does for matter and energy), and applying simple logic, suggests a "cosmic fabric" of the simplest, stable particles of matter, at the lowest energy state possible: singlet state, spin-oriented atomic hydrogen at zero kelvin, at a density of, at most, only a few atoms per cubic meter of space, infinite and (almost) eternal. Papers II and III describe the condensation of part of the cosmic fabric into a Bose-Einstein condensate (BEC) as Lemaître's primeval atom, followed by an implosion- explosion Big Bang.

Tympanic ear thermometer assessment of body temperature among patients with cognitive disturbances. An acceptable and ethically desirable alternative?

Science.gov (United States)

Aadal, Lena; Fog, Lisbet; Pedersen, Asger Roer

2016-12-01

Investigation of a possible relation between body temperature measurements by the current generation of tympanic ear and rectal thermometers. In Denmark, a national guideline recommends the rectal measurement. Subsequently, the rectal thermometers and tympanic ear devices are the most frequently used and first choice in Danish hospital wards. Cognitive changes constitute challenges with cooperating in rectal temperature assessments. With regard to diagnosing, ethics, safety and the patients' dignity, the tympanic ear thermometer might comprise a desirable alternative to rectal noninvasive measurement of body temperature during in-hospital-based neurorehabilitation. A prospective, descriptive cohort study. Consecutive inclusion of 27 patients. Linear regression models were used to analyse 284 simultaneous temperature measurements. Ethical approval for this study was granted by the Danish Data Protection Agency, and the study was completed in accordance with the Helsinki Declaration 2008. About 284 simultaneous rectal and ear temperature measurements on 27 patients were analysed. The patient-wise variability of measured temperatures was significantly higher for the ear measurements. Patient-wise linear regressions for the 25 patients with at least three pairs of simultaneous ear and rectal temperature measurements showed large interpatient variability of the association. A linear relationship between the rectal body temperature assessment and the temperature assessment employing the tympanic thermometer is weak. Both measuring methods reflect variance in temperature, but ear measurements showed larger variation. © 2016 Nordic College of Caring Science.

Nano-liquid chromatography applied to enantiomers separation.

Science.gov (United States)

Fanali, Salvatore

2017-02-24

This paper presents the state of the art concerning the separation of chiral compounds by means of nano-liquid chromatography (nano-LC). The enantiomers' separation and determination are a subject of fundamental importance in various application fields such as pharmaceutical industry, biomedicine, food, agrochemical etc. Nano-LC is a miniaturized chromatographic technique offering some advantages over conventional ones such as low consumption of mobile phase, sample volume and amount of chiral stationary phase, reduced costs etc. This is reported in the first part of the paper illustrating the features of the nano-LC. In addition, chiral resolution methods are briefly illustrated. Some chiral selectors, used in high-performance liquid chromatography have also been applied in nano-LC including cyclodextrins, glycopeptide antibiotics, modified polysaccharides etc. This is discussed in the second part of the review. Finally some examples of the applications available in literature are reported. Copyright © 2016 Elsevier B.V. All rights reserved.

Resolution, sensitivity, and in vivo application of high-resolution computed tomography for titanium-coated polymethyl methacrylate (PMMA) dental implants

NARCIS (Netherlands)

Cuijpers, V.M.J.I.; Jaroszewicz, J.; Anil, S.; Al Farraj Aldosari, A.; Walboomers, X.F.; Jansen, J.A.

2014-01-01

OBJECTIVES: The aims of this study were (i) to determine the spatial resolution and sensitivity of micro- versus nano-computed tomography (CT) techniques and (ii) to validate micro- versus nano-CT in a dog dental implant model, comparative to histological analysis. MATERIAL AND METHODS: To determine

Radiation stability of low-temperature resistance thermometers

International Nuclear Information System (INIS)

Neklyudov, I.M.; Petrusenko, Yu.T.; Sleptsov, A.N.; Logvinenko, S.P.; Mikhina, G.F.; Rossoshanskij, O.A.

1989-01-01

The effect of low temperature (∼ 5 and 11 K) irradiation with E=30 MeV electrons and the subsequent annealing at 180 and 300 K on gauge dependences R(T) of resistance thermometers (RT) on the basis of p-GaAs, Ni and In is investigated. For GaAs-RT the dependence of electroresistance R(4.2 K) on the irradiation fluence is shown to be non monotonic. The annealing at 180 and 300 K does not restore GaAs-RT thermometric characteristics but it leads to their further degradation. The annealing of Ni and In irradiated RT's at T>180 K leads to total restoring of their electrophysical properties. 16 refs.; 5 figs.; 1 tab

Lens transmission measurement for an absolute radiation thermometer

International Nuclear Information System (INIS)

Hao, X.; Yuan, Z.; Lu, X.

2013-01-01

The lens transmission for the National Institute of Metrology of China absolute radiation thermometer is measured by a hybrid method. The results of the lens transmission measurements are 99.002% and 86.792% for filter radiometers with center wavelengths 633 nm and 900 nm, respectively. These results, after correcting for diffraction factors and the size-of-source effect when the lens is incorporated within the radiometer, can be used for measurement of thermodynamic temperature. The expanded uncertainty of the lens transmission measurement system has been evaluated. It is 1.3×10 −3 at 633 nm and 900 nm, respectively

Gamma thermometer allowing absolute and differential temperature measurements

International Nuclear Information System (INIS)

Bottin, P.; Schley, R.

1985-01-01

The gamma thermometer comprises an external envelope containing a cylindrical rod with a central bore and, thick and thin parts defining insulating chambers, at least one thermocouple set in the said central bore; the thermocouple has three junctions connected to one of their end parts by a junction at the level of a thin part, while one at least of the wires comprises two elements made of different materials connected by a junction at the level of a thick part. The present invention applies more particularly for detecting level of the coolant in a nuclear reactor [fr

[The test of medical service of the implementation of modern methods of prophylaxis of acute respiratory infection in the forces].

Science.gov (United States)

Alimov, A V; Aminev, R M; Ustinov, A E; Matreninskaia, E S

2011-01-01

In the article are presented the technologies, regular usage of which let attain important decrease of the level of airborne infections in the period of epidemic. These technologies are noncontact infared thermometer "Kelvin-kompakt" 201 (M1), medication in aerosol packing "Bakteroks Mentol" for the air disinfection in small rooms (medical squadron, unauthorized sick-room), photocatalytic air disinfectant "Airlife".

Measurement capability overview in PolyNano

DEFF Research Database (Denmark)

Calaon, Matteo; Tosello, Guido; Hansen, Hans Nørgaard

2012-01-01

A measurement capability overview has been conducted to evaluate, among the most used instruments in the field of nanometrology, where the PolyNano project should focus its research. The deliverable presents the most relevant instruments to achieve the best possible measurements accuracy matching...... requirements such as low uncertainty, high repeatability and resolution, adequate measuring range and availability among the different project partners. Based on the present measurement capability overview and in relation to the objective of PolyNano to “remove the technology barrier between lab‐scale proof...

Optical and Structural Characterizations of GaN Nano structures

International Nuclear Information System (INIS)

Shekari, L.; Abu Hassan, H.; Thahab, S.M.

2011-01-01

We have grown wurtzite GaN nano wires (NWs) on polished silicon (Si) either with or without Au as catalyst, using commercial GaN powder by thermal evaporation in an atmosphere of argon (Ar) gas. Structural and optical characterizations were performed using high resolution X-ray diffraction (HR-XRD), scanning electron microscopy (SEM), photoluminescence (PL) and energy-dispersive X-ray spectroscopy (EDX) spectroscopy. Results indicate that the nano wires are of single-crystal hexagonal GaN and the nano wires on Si with Au catalyst are more oriented than those without Au catalyst; and using catalyst make the NWs grow much faster and quite well-ordered. The compositional quality of the grown nano wires on the substrates are mostly same, however the nano wires on the Au coated silicon are of low density, while the nano wires on the Si are of high density. (author)

A Nano-indentation Identification Technique for Viscoelastic Constitutive Characteristics of Periodontal Ligaments

Directory of Open Access Journals (Sweden)

Ashrafi H.

2016-06-01

Full Text Available Introduction: Nano-indentation has recently been employed as a powerful tool for determining the mechanical properties of biological tissues on nano and micro scales. A majority of soft biological tissues such as ligaments and tendons exhibit viscoelastic or time-dependent behaviors. The constitutive characterization of soft tissues is among very important subjects in clinical medicine and especially, biomechanics fields. Periodontal ligament plays an important role in initiating tooth movement when loads are applied to teeth with orthodontic appliances. It is also the most accessible ligament in human body as it can be directly manipulated without any surgical intervention. From a mechanical point of view, this ligament can be considered as a thin interface made by a solid phase, consisting mainly of collagen fibers, which is immersed into a so-called ground substance. However, the viscoelastic constitutive effects of biological tissues are seldom considered rigorous during Nano-indentation tests. Methods: In the present paper, a mathematical contact approach is developed to enable determining creep compliance and relaxation modulus of distinct periodontal ligaments, using constant–rate indentation and loading time histories, respectively. An adequate curve-fitting method is presented to determine these characteristics based on the Nano-indentation of rigid Berkovich tips. Generalized Voigt-Kelvin and Wiechert models are used to model constitutive equations of periodontal ligaments, in which the relaxation and creep functions are represented by series of decaying exponential functions of time. Results: Time-dependent creep compliance and relaxation function have been obtained for tissue specimens of periodontal ligaments. Conclusion: To improve accuracy, relaxation and creep moduli are measured from two tests separately. Stress relaxation effects appear more rapidly than creep in the periodontal ligaments.

The 17/5 spectrum of the Kelvin-wave cascade

OpenAIRE

Kozik, Evgeny; Svistunov, Boris

2010-01-01

Direct numeric simulation of the Biot-Savart equation readily resolves the 17/5 spectrum of the Kelvin-wave cascade from the 11/3 spectrum of the non-local (in the wavenumber space) cascade scenario by L'vov and Nazarenko. This result is a clear-cut visualisation of the unphysical nature of the 11/3 solution, which was established earlier on the grounds of symmetry.

Reflection of equatorial Kelvin waves at eastern ocean boundaries Part I: hypothetical boundaries

Directory of Open Access Journals (Sweden)

J. Soares

1999-06-01

Full Text Available A baroclinic shallow-water model is developed to investigate the effect of the orientation of the eastern ocean boundary on the behavior of equatorial Kelvin waves. The model is formulated in a spherical polar coordinate system and includes dissipation and non-linear terms, effects which have not been previously included in analytical approaches to the problem. Both equatorial and middle latitude response are considered given the large latitudinal extent used in the model. Baroclinic equatorial Kelvin waves of intraseasonal, seasonal and annual periods are introduced into the domain as pulses of finite width. Their subsequent reflection, transmission and dissipation are investigated. It is found that dissipation is very important for the transmission of wave energy along the boundary and for reflections from the boundary. The dissipation was found to be dependent not only on the presence of the coastal Kelvin waves in the domain, but also on the period of these coastal waves. In particular the dissipation increases with wave period. It is also shown that the equatorial β-plane approximation can allow an anomalous generation of Rossby waves at higher latitudes. Nonlinearities generally have a small effect on the solutions, within the confines of this model.Key words. Oceanography: general (equatorial oceanography; numerical modeling · Oceanography: physical (eastern boundary currents

Preventing probe induced topography correlated artifacts in Kelvin Probe Force Microscopy

NARCIS (Netherlands)

Polak, L.; Wijngaarden, Rinke J.

2016-01-01

Kelvin Probe Force Microscopy (KPFM) on samples with rough surface topography can be hindered by topography correlated artifacts. We show that, with the proper experimental configuration and using homogeneously metal coated probes, we are able to obtain amplitude modulation (AM) KPFM results on a

Observations of Equatorial Kelvin Wave Modes in FORMOSAT-3/COSMIC GPS RO Temperature Profiles

Directory of Open Access Journals (Sweden)

Potula Sree Brahmanandam

2010-01-01

Full Text Available In this study, we analyze FORMOSAT-3/COSMIC (F3/C GPS radio occultation (RO derived temperature components for the period September 2006 to February 2008. Results show the presence of slow Kelvin waves (wave period > 10 days with higher zonal wavenumbers (either one or two in the upper troposphere and lower stratosphere (UTLS. The vertical wavelengths of these waves are found to be in the range of 5 - 12 km. The predominant Kelvin waves observed in the temperature fluctuations are in the altitude range between 15 and 28 km and centered on the tropical tropopause. The downward phase progression of these waves suggests that the derived waves are propagating upward, with the source region located at lower altitudes possibly due to tropical convective heating. The zonal winds retrieved using radiosonde observations over Singapore (1¢XN, 104¢XE during this period show a periodicity of ~24 - 26 months in the stratosphere, and quasi-biennial oscillation (QBO characteristics with eastward zonal winds from March 2006 to May 2007 and westward winds from June 2007 to July 2008 respectively. Our results further show that the Kelvin wave characteristics are enhanced during the westward phase of QBO and diminish during the eastward phase, in line with the previous reported results. Furthermore, an examination of outgoing longwave radiation (OLR data shows that deep convection activity is developed episodically over the Indonesian archipelago during the observation period, thereby indicating that the Kelvin wave events observed in temperature fluctuations are either driven by convective activity (convectively coupled waves or by a broad spectrum of convective variability (free waves over the Indonesian region.

Convectively coupled Kelvin waves in aquachannel simulations: 2. Life cycle and dynamical-convective coupling

Science.gov (United States)

Blanco, Joaquín. E.; Nolan, David S.; Mapes, Brian E.

2016-10-01

This second part of a two-part study uses Weather Research and Forecasting simulations with aquachannel and aquapatch domains to investigate the time evolution of convectively coupled Kelvin waves (CCKWs). Power spectra, filtering, and compositing are combined with object-tracking methods to assess the structure and phase speed propagation of CCKWs during their strengthening, mature, and decaying phases. In this regard, we introduce an innovative approach to more closely investigate the wave (Kelvin) versus entity (super cloud cluster or "SCC") dualism. In general, the composite CCKW structures represent a dynamical response to the organized convective activity. However, pressure and thermodynamic fields in the boundary layer behave differently. Further analysis of the time evolution of pressure and low-level moist static energy finds that these fields propagate eastward as a "moist" Kelvin wave (MKW), faster than the envelope of organized convection or SCC. When the separation is sufficiently large the SCC dissipates, and a new SCC generates to the east, in the region of strongest negative pressure perturbations. We revisit the concept itself of the "coupling" between convection and dynamics, and we also propose a conceptual model for CCKWs, with a clear distinction between the SCC and the MKW components.

NanoXCT: a novel technique to probe the internal architecture of pharmaceutical particles.

Science.gov (United States)

Wong, Jennifer; D'Sa, Dexter; Foley, Matthew; Chan, John Gar Yan; Chan, Hak-Kim

2014-11-01

To demonstrate the novel application of nano X-ray computed tomography (NanoXCT) for visualizing and quantifying the internal structures of pharmaceutical particles. An Xradia NanoXCT-100, which produces ultra high-resolution and non-destructive imaging that can be reconstructed in three-dimensions (3D), was used to characterize several pharmaceutical particles. Depending on the particle size of the sample, NanoXCT was operated in Zernike Phase Contrast (ZPC) mode using either: 1) large field of view (LFOV), which has a two-dimensional (2D) spatial resolution of 172 nm; or 2) high resolution (HRES) that has a resolution of 43.7 nm. Various pharmaceutical particles with different physicochemical properties were investigated, including raw (2-hydroxypropyl)-beta-cyclodextrin (HβCD), poly (lactic-co-glycolic) acid (PLGA) microparticles, and spray-dried particles that included smooth and nanomatrix bovine serum albumin (BSA), lipid-based carriers, and mannitol. Both raw HβCD and PLGA microparticles had a network of voids, whereas spray-dried smooth BSA and mannitol generally had a single void. Lipid-based carriers and nanomatrix BSA particles resulted in low quality images due to high noise-to-signal ratio. The quantitative capabilities of NanoXCT were also demonstrated where spray-dried mannitol was found to have an average void volume of 0.117 ± 0.247 μm(3) and average void-to-material percentage of 3.5%. The single PLGA particle had values of 1993 μm(3) and 59.3%, respectively. This study reports the first series of non-destructive 3D visualizations of inhalable pharmaceutical particles. Overall, NanoXCT presents a powerful tool to dissect and observe the interior of pharmaceutical particles, including those of a respirable size.

Kelvin-Helmholtz instability in a weakly ionized layer

OpenAIRE

Shadmehri, Mohsen; Downes, Turlough P.

2007-01-01

We study the linear theory of Kelvin-Helmholtz instability in a layer of ions and neutrals with finite thickness. In the short wavelength limit the thickness of the layer has a negligible effect on the growing modes. However, perturbations with wavelength comparable to layer's thickness are significantly affected by the thickness of the layer. We show that the thickness of the layer has a stabilizing effect on the two dominant growing modes. Transition between the modes not only depends on th...

Pumping liquid metal at high temperatures up to 1,673 kelvin

Science.gov (United States)

Amy, C.; Budenstein, D.; Bagepalli, M.; England, D.; Deangelis, F.; Wilk, G.; Jarrett, C.; Kelsall, C.; Hirschey, J.; Wen, H.; Chavan, A.; Gilleland, B.; Yuan, C.; Chueh, W. C.; Sandhage, K. H.; Kawajiri, Y.; Henry, A.

2017-10-01

Heat is fundamental to power generation and many industrial processes, and is most useful at high temperatures because it can be converted more efficiently to other types of energy. However, efficient transportation, storage and conversion of heat at extreme temperatures (more than about 1,300 kelvin) is impractical for many applications. Liquid metals can be very effective media for transferring heat at high temperatures, but liquid-metal pumping has been limited by the corrosion of metal infrastructures. Here we demonstrate a ceramic, mechanical pump that can be used to continuously circulate liquid tin at temperatures of around 1,473-1,673 kelvin. Our approach to liquid-metal pumping is enabled by the use of ceramics for the mechanical and sealing components, but owing to the brittle nature of ceramics their use requires careful engineering. Our set-up enables effective heat transfer using a liquid at previously unattainable temperatures, and could be used for thermal storage and transport, electric power production, and chemical or materials processing.

Reproductive solutions for the g-Navier-Stokes and g-Kelvin-Voight equations

Directory of Open Access Journals (Sweden)

Luis Friz

2016-01-01

Full Text Available This article presents the existence of reproductive solutions of g-Navier-Stokes and g-Kelvin-Voight equations. In this way, for weak solutions, we reach basically the same result as for classic Navier-Stokes equations.

A Nano-indentation Identification Technique for Viscoelastic Constitutive Characteristics of Periodontal Ligaments.

Science.gov (United States)

Ashrafi, H; Shariyat, M

2016-06-01

Nano-indentation has recently been employed as a powerful tool for determining the mechanical properties of biological tissues on nano and micro scales. A majority of soft biological tissues such as ligaments and tendons exhibit viscoelastic or time-dependent behaviors. The constitutive characterization of soft tissues is among very important subjects in clinical medicine and especially, biomechanics fields. Periodontal ligament plays an important role in initiating tooth movement when loads are applied to teeth with orthodontic appliances. It is also the most accessible ligament in human body as it can be directly manipulated without any surgical intervention. From a mechanical point of view, this ligament can be considered as a thin interface made by a solid phase, consisting mainly of collagen fibers, which is immersed into a so-called ground substance. However, the viscoelastic constitutive effects of biological tissues are seldom considered rigorous during Nano-indentation tests. In the present paper, a mathematical contact approach is developed to enable determining creep compliance and relaxation modulus of distinct periodontal ligaments, using constant-rate indentation and loading time histories, respectively. An adequate curve-fitting method is presented to determine these characteristics based on the Nano-indentation of rigid Berkovich tips. Generalized Voigt-Kelvin and Wiechert models are used to model constitutive equations of periodontal ligaments, in which the relaxation and creep functions are represented by series of decaying exponential functions of time. Time-dependent creep compliance and relaxation function have been obtained for tissue specimens of periodontal ligaments. To improve accuracy, relaxation and creep moduli are measured from two tests separately. Stress relaxation effects appear more rapidly than creep in the periodontal ligaments.

A Nano-indentation Identification Technique for Viscoelastic Constitutive Characteristics of Periodontal Ligaments

Science.gov (United States)

Ashrafi, H.; Shariyat, M.

2016-01-01

Introduction Nano-indentation has recently been employed as a powerful tool for determining the mechanical properties of biological tissues on nano and micro scales. A majority of soft biological tissues such as ligaments and tendons exhibit viscoelastic or time-dependent behaviors. The constitutive characterization of soft tissues is among very important subjects in clinical medicine and especially, biomechanics fields. Periodontal ligament plays an important role in initiating tooth movement when loads are applied to teeth with orthodontic appliances. It is also the most accessible ligament in human body as it can be directly manipulated without any surgical intervention. From a mechanical point of view, this ligament can be considered as a thin interface made by a solid phase, consisting mainly of collagen fibers, which is immersed into a so-called ground substance. However, the viscoelastic constitutive effects of biological tissues are seldom considered rigorous during Nano-indentation tests. Methods In the present paper, a mathematical contact approach is developed to enable determining creep compliance and relaxation modulus of distinct periodontal ligaments, using constant–rate indentation and loading time histories, respectively. An adequate curve-fitting method is presented to determine these characteristics based on the Nano-indentation of rigid Berkovich tips. Generalized Voigt-Kelvin and Wiechert models are used to model constitutive equations of periodontal ligaments, in which the relaxation and creep functions are represented by series of decaying exponential functions of time. Results Time-dependent creep compliance and relaxation function have been obtained for tissue specimens of periodontal ligaments. Conclusion To improve accuracy, relaxation and creep moduli are measured from two tests separately. Stress relaxation effects appear more rapidly than creep in the periodontal ligaments. PMID:27672630

Magnetic bead detection using nano-transformers

Energy Technology Data Exchange (ETDEWEB)

Kim, Hyung Kwon; Ahn, Doyeol [Institute of Quantum Information Processing and Systems, University of Seoul, 90 Jeonnong, Dongdaemun, Seoul 130-743 (Korea, Republic of); Hwang, Jong Seung; Hwang, Sung Woo, E-mail: dahn@uos.ac.kr [Research Center for Time-domain Nano-functional Devices and School of Electrical Engineering, Korea University, 5-1 Anam, Sungbuk, Seoul 136-701 (Korea, Republic of)

2010-11-19

A novel scheme to detect magnetic beads using a nano-scale transformer with a femtoweber resolution is reported. We have performed a Faraday's induction experiment with the nano-transformer at room temperature. The transformer shows the linear output voltage responses to the sinusoidal input current. When magnetic beads are placed on the transformer, the output responses are increased by an amount corresponding to the added magnetic flux from the beads when compared with the case of no beads on the transformer. In this way, we could determine whether magnetic beads are on top of the transformer in a single particle level.

Magnetic bead detection using nano-transformers.

Science.gov (United States)

Kim, Hyung Kwon; Hwang, Jong Seung; Hwang, Sung Woo; Ahn, Doyeol

2010-11-19

A novel scheme to detect magnetic beads using a nano-scale transformer with a femtoweber resolution is reported. We have performed a Faraday's induction experiment with the nano-transformer at room temperature. The transformer shows the linear output voltage responses to the sinusoidal input current. When magnetic beads are placed on the transformer, the output responses are increased by an amount corresponding to the added magnetic flux from the beads when compared with the case of no beads on the transformer. In this way, we could determine whether magnetic beads are on top of the transformer in a single particle level.

Raster-scanning serial protein crystallography using micro- and nano-focused synchrotron beams

Energy Technology Data Exchange (ETDEWEB)

Coquelle, Nicolas [Université Grenoble Alpes, IBS, 38044 Grenoble (France); CNRS, IBS, 38044 Grenoble (France); CEA, IBS, 38044 Grenoble (France); Brewster, Aaron S. [Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Kapp, Ulrike; Shilova, Anastasya; Weinhausen, Britta [European Synchrotron Radiation Facility, BP 220, 38043 Grenoble (France); Burghammer, Manfred, E-mail: burgham@esrf.fr [European Synchrotron Radiation Facility, BP 220, 38043 Grenoble (France); Ghent University, Ghent B-9000 (Belgium); Colletier, Jacques-Philippe, E-mail: burgham@esrf.fr [Université Grenoble Alpes, IBS, 38044 Grenoble (France); CNRS, IBS, 38044 Grenoble (France); CEA, IBS, 38044 Grenoble (France)

2015-05-01

A raster scanning serial protein crystallography approach is presented, that consumes as low ∼200–700 nl of sedimented crystals. New serial data pre-analysis software, NanoPeakCell, is introduced. High-resolution structural information was obtained from lysozyme microcrystals (20 µm in the largest dimension) using raster-scanning serial protein crystallography on micro- and nano-focused beamlines at the ESRF. Data were collected at room temperature (RT) from crystals sandwiched between two silicon nitride wafers, thereby preventing their drying, while limiting background scattering and sample consumption. In order to identify crystal hits, new multi-processing and GUI-driven Python-based pre-analysis software was developed, named NanoPeakCell, that was able to read data from a variety of crystallographic image formats. Further data processing was carried out using CrystFEL, and the resultant structures were refined to 1.7 Å resolution. The data demonstrate the feasibility of RT raster-scanning serial micro- and nano-protein crystallography at synchrotrons and validate it as an alternative approach for the collection of high-resolution structural data from micro-sized crystals. Advantages of the proposed approach are its thriftiness, its handling-free nature, the reduced amount of sample required, the adjustable hit rate, the high indexing rate and the minimization of background scattering.

Collisionless Kelvin-Helmholtz instability and vortex-induced reconnection in the external region of the Earth magnetotail

International Nuclear Information System (INIS)

Pegoraro, F; Faganello, M; Califano, F

2008-01-01

In a magnetized plasma streaming with a non uniform velocity, the Kelvin-Helmholtz instability plays a major role in mixing different plasma regions and in stretching the magnetic field lines leading to the formation of layers with a sheared magnetic field where magnetic field line reconnection can take place. A relevant example is provided by the formation of a mixing layer between the Earth's magnetosphere and the solar wind at low latitudes during northward periods. In the considered configuration, in the presence of a magnetic field nearly perpendicular to the plane defined by the velocity field and its inhomogeneity direction, velocity shear drives a Kelvin-Helmholtz instability which advects and distorts the magnetic field configuration. If the Alfven velocity associated to the in-plane magnetic field is sufficiently weak with respect to the variation of the fluid velocity in the plasma, the Kelvin-Helmholtz instability generates fully rolled-up vortices which advect the magnetic field lines into a complex configuration, causing the formation of current layers along the inversion curves of the in-plane magnetic field component. Pairing of the vortices generated by the Kelvin-Helmholtz instability is a well know phenomenon in two-dimensional hydrodynamics. Here we investigate the development of magnetic reconnection during the vortex pairing process and show that completely different magnetic structures are produced depending on how fast the reconnection process develops on the time scale set by the pairing process.

A single-layer flat-coil-oscillator (SFCO)-based super-broadband position sensor for nano-scale-resolution seismometry

Energy Technology Data Exchange (ETDEWEB)

Gevorgyan, Samvel [Department of Physics, Yerevan State University, 1 Alex Manoogian Street, Yerevan 0025 (Armenia); Institute for Physical Researches, National Academy of Sciences, Gitavan IFI, 0203 Ashtarak-2 (Armenia)], E-mail: gevs_sam@web.am; Gevorgyan, Vardan [Department of Physics, Yerevan State University, 1 Alex Manoogian Street, Yerevan 0025 (Armenia); Institute for Physical Researches, National Academy of Sciences, Gitavan IFI, 0203 Ashtarak-2 (Armenia); International Scientific-Educational Center, National Academy of Sciences, 24-D Marshal Baghramyan av., Yerevan 0019 (Armenia); Karapetyan, Gagik [Department of Physics, Yerevan State University, 1 Alex Manoogian Street, Yerevan 0025 (Armenia); Institute for Physical Researches, National Academy of Sciences, Gitavan IFI, 0203 Ashtarak-2 (Armenia)

2008-05-15

A new class super-broadband, nano-scale-resolution position sensor is tested. It is used as an additional sensor in seismograph. It enables to extend the band and enhance the sensitivity of the available technique by at least an order of magnitude. It allows transferring of mechanical vibrations of constructions and buildings, with amplitudes over 1 nm, into detectable signal in a frequency range starting practically from quasi-static movements. It is based on detection of position changes of a vibrating normal-metallic plate placed near the flat coil-being used as a pick-up in a stable tunnel diode oscillator. Frequency of the oscillator is used as a detecting parameter, and the measuring effect is determined by a distortion of the MHz-range testing field configuration near a coil by a vibrating plate, leading to magnetic inductance changes of the coil, with a resolution {approx}10 pH. This results in changes of oscillator frequency. We discuss test data of such a position sensor, installed in a Russian SM-3 seismometer, as an additional pick-up component, showing its advantages compared to traditional techniques. We also discuss the future of such a novel sensor involving substitution of a metallic coil by a superconductive one and replacement of a tunnel diode by an S/I/S hetero-structure-as much less-powered active element in the oscillator, compared to tunnel diode. These may strongly improve the stability of oscillators, and therefore enhance the resolution of seismic techniques.

Flame synthesis of carbon nano onions using liquefied petroleum gas without catalyst

International Nuclear Information System (INIS)

Dhand, Vivek; Prasad, J. Sarada; Rao, M. Venkateswara; Bharadwaj, S.; Anjaneyulu, Y.; Jain, Pawan Kumar

2013-01-01

Densely agglomerated, high specific surface area carbon nano onions with diameter of 30–40 nm have been synthesized. Liquefied petroleum gas and air mixtures produced carbon nano onions in diffusion flames without catalyst. The optimized oxidant to fuel ratio which produces carbon nano onions has been found to be 0.1 slpm/slpm. The experiment yielded 70% pure carbon nano onions with a rate of 5 g/h. X-ray diffraction, high-resolution electron microscopy and Raman spectrum reveal the densely packed sp 2 hybridized carbon with (002) semi-crystalline hexagonal graphite reflection. The carbon nano onions are thermally stable up to 600 °C. - Highlights: ►Flame synthesized carbon nano onions with 30–40 nm diameters. ►LPG/air, diffusion type flame used in absence of catalyst to produce nano onions. ►Carbon nano onion production rate is 5 g/hr and with 70% purity.

Correction of the dynamic response of the ''Gamma thermometers'' using a digital filter

International Nuclear Information System (INIS)

Jacquot, J.P.; Lobert, J.P.

1985-01-01

The ''gamma thermometer'' is a sensor used to measure on line the local power inside a PWR nuclear reactor. During transients, this sensor based on thermal exchanges, obes not give a fast response. This paper describes a microprocessor device that allows using a digital filtering technique, a correction of the dynamic response [fr

Epitaxial growth of pentacene on alkali halide surfaces studied by Kelvin probe force microscopy.

Science.gov (United States)

Neff, Julia L; Milde, Peter; León, Carmen Pérez; Kundrat, Matthew D; Eng, Lukas M; Jacob, Christoph R; Hoffmann-Vogel, Regina

2014-04-22

In the field of molecular electronics, thin films of molecules adsorbed on insulating surfaces are used as the functional building blocks of electronic devices. Control of the structural and electronic properties of the thin films is required for reliably operating devices. Here, noncontact atomic force and Kelvin probe force microscopies have been used to investigate the growth and electrostatic landscape of pentacene on KBr(001) and KCl(001) surfaces. We have found that, together with molecular islands of upright standing pentacene, a new phase of tilted molecules appears near step edges on KBr. Local contact potential differences (LCPD) have been studied with both Kelvin experiments and density functional theory calculations. Our images reveal that differently oriented molecules display different LCPD and that their value is independent of the number of molecular layers. These results point to the formation of an interface dipole, which may be explained by a partial charge transfer from the pentacene to the surface. Moreover, the monitoring of the evolution of the pentacene islands shows that they are strongly affected by dewetting: Multilayers build up at the expense of monolayers, and in the Kelvin images, previously unknown line defects appear, which reveal the epitaxial growth of pentacene crystals.

Kelvin probe characterization of buried graphitic microchannels in single-crystal diamond

International Nuclear Information System (INIS)

Bernardi, E.; Battiato, A.; Olivero, P.; Vittone, E.; Picollo, F.

2015-01-01

In this work, we present an investigation by Kelvin Probe Microscopy (KPM) of buried graphitic microchannels fabricated in single-crystal diamond by direct MeV ion microbeam writing. Metal deposition of variable-thickness masks was adopted to implant channels with emerging endpoints and high temperature annealing was performed in order to induce the graphitization of the highly-damaged buried region. When an electrical current was flowing through the biased buried channel, the structure was clearly evidenced by KPM maps of the electrical potential of the surface region overlying the channel at increasing distances from the grounded electrode. The KPM profiling shows regions of opposite contrast located at different distances from the endpoints of the channel. This effect is attributed to the different electrical conduction properties of the surface and of the buried graphitic layer. The model adopted to interpret these KPM maps and profiles proved to be suitable for the electronic characterization of buried conductive channels, providing a non-invasive method to measure the local resistivity with a micrometer resolution. The results demonstrate the potential of the technique as a powerful diagnostic tool to monitor the functionality of all-carbon graphite/diamond devices to be fabricated by MeV ion beam lithography

Vertically etched silicon nano-rods as a sensitive electron detector

International Nuclear Information System (INIS)

Hajmirzaheydarali, M; Akbari, M; Soleimani-Amiri, S; Sadeghipari, M; Shahsafi, A; Akhavan Farahani, A; Mohajerzadeh, S

2015-01-01

We have used vertically etched silicon nano-rods to realize electron detectors suitable for scanning electron microscopes. The results of deep etching of silicon nano-structures are presented to achieve highly ordered arrays of nano-rods. The response of the electron detector to energy of the primary electron beam and the effects of various sizes and materials has been investigated, indicating its high sensitivity to secondary and back-scattered electrons. The miniaturized structure of this electron detector allows it to be placed in the vicinity of the specimen to improve the resolution and contrast. This detector collects electrons and converts the electron current to voltage directly by means of n-doped silicon nano-rods on a p-type silicon substrate. Silicon nano-rods enhance the surface-to-volume ratio of the detector as well as improving the yield of electron detection. The use of nano-structures and silicon nanowires as an electron detector has led to higher sensitivities than with micro-structures. (paper)

Synthesis of Boron Nano wires, Nano tubes, and Nano sheets

International Nuclear Information System (INIS)

Patel, R.B.; Chou, T.; Iqbal, Z.

2014-01-01

The synthesis of boron nano wires, nano tubes, and nano sheets using a thermal vapor deposition process is reported. This work confirms previous research and provides a new method capable of synthesizing boron nano materials. The materials were made by using various combinations of MgB 2 , Mg(BH 4 ) 2 , MCM-41, NiB, and Fe wire. Unlike previously reported methods, a nanoparticle catalyst and a silicate substrate are not required for synthesis. Two types of boron nano wires, boron nano tubes, and boron nano sheets were made. Their morphology and chemical composition were determined through the use of scanning electron microscopy, transmission electron microscopy, and electron energy loss spectroscopy. These boron-based materials have potential for electronic and hydrogen storage applications.

Impact of wall potential on the fluid-wall interaction in a cylindrical capillary and a generalized Kelvin equation

International Nuclear Information System (INIS)

Jakubov, T.S.; Mainwaring, D.E.

2006-01-01

In the present work a generalized Kelvin equation for a fluid confined in thick-walled cylindrical capillary is developed. This has been accomplished by including the potential energy function for interaction between a solid wall of a capillary and a confined fluid into the Kelvin equation. Using the Lennard-Jones 12-6 potential, an explicit form of the potential energy functions as expressed by hypergeometrical functions have been derived-firstly, for the interaction between a solid wall and a test atom placed at an arbitrary point in a long open-end capillary, and thereafter for the body-body interaction between the solid wall and a confined Lennard-Jones fluid. Further, this generalized Kelvin equation has been applied to detailed description hysteresis phenomena in such capillaries. All numerical calculations have been carried out for the model argon-graphite system at 90 K

Flame synthesis of carbon nano onions using liquefied petroleum gas without catalyst

Energy Technology Data Exchange (ETDEWEB)

Dhand, Vivek, E-mail: vivekdhand2012@gmail.com [Centre for Knowledge Management of Nanoscience and Technology, 12-5-32/8, Vijayapuri Colony, Tarnaka, Secunderabad-500 017, A.P (India); Prasad, J. Sarada; Rao, M. Venkateswara [Centre for Environment, Institute of Science and Technology, Jawaharlal Nehru Technological University, Kukatpally, Hyderabad 500 085 (India); Bharadwaj, S. [Department of Physics, CVR College of Engineering and Osmania University, Hyderabad 501510, A.P (India); Anjaneyulu, Y. [TLGVRC, Jackson State University, JSU Box 18739, Jackson, MS 39217-0939 (United States); Jain, Pawan Kumar [International Advanced Research Centre for Powder Metallurgy and New Materials (ARCI), Balapur PO, Hyderabad 500005, Andhra Pradesh (India)

2013-03-01

Densely agglomerated, high specific surface area carbon nano onions with diameter of 30-40 nm have been synthesized. Liquefied petroleum gas and air mixtures produced carbon nano onions in diffusion flames without catalyst. The optimized oxidant to fuel ratio which produces carbon nano onions has been found to be 0.1 slpm/slpm. The experiment yielded 70% pure carbon nano onions with a rate of 5 g/h. X-ray diffraction, high-resolution electron microscopy and Raman spectrum reveal the densely packed sp{sup 2} hybridized carbon with (002) semi-crystalline hexagonal graphite reflection. The carbon nano onions are thermally stable up to 600 Degree-Sign C. - Highlights: Black-Right-Pointing-Pointer Flame synthesized carbon nano onions with 30-40 nm diameters. Black-Right-Pointing-Pointer LPG/air, diffusion type flame used in absence of catalyst to produce nano onions. Black-Right-Pointing-Pointer Carbon nano onion production rate is 5 g/hr and with 70% purity.

Fractional Generalizations of Maxwell and Kelvin-Voigt Models for Biopolymer Characterization.

Directory of Open Access Journals (Sweden)

Bertrand Jóźwiak

Full Text Available The paper proposes a fractional generalization of the Maxwell and Kelvin-Voigt rheological models for a description of dynamic behavior of biopolymer materials. It was found that the rheological models of Maxwell-type do not work in the case of modeling of viscoelastic solids, and the model which significantly better describes the nature of changes in rheological properties of such media is the modified fractional Kelvin-Voigt model with two built-in springpots (MFKVM2. The proposed model was used to describe the experimental data from the oscillatory and creep tests of 3% (w/v kuzu starch pastes, and to determine the values of their rheological parameters as a function of pasting time. These parameters provide a lot of additional information about structure and viscoelastic properties of the medium in comparison to the classical analysis of dynamic curves G' and G" and shear creep compliance J(t. It allowed for a comprehensive description of a wide range of properties of kuzu starch pastes, depending on the conditions of pasting process.

Nano-technology and nano-toxicology.

Science.gov (United States)

Maynard, Robert L

2012-01-01

Rapid developments in nano-technology are likely to confer significant benefits on mankind. But, as with perhaps all new technologies, these benefits are likely to be accompanied by risks, perhaps by new risks. Nano-toxicology is developing in parallel with nano-technology and seeks to define the hazards and risks associated with nano-materials: only when risks have been identified they can be controlled. This article discusses the reasons for concern about the potential effects on health of exposure to nano-materials and relates these to the evidence of the effects on health of the ambient aerosol. A number of hypotheses are proposed and the dangers of adopting unsubstantiated hypotheses are stressed. Nano-toxicology presents many challenges and will need substantial financial support if it is to develop at a rate sufficient to cope with developments in nano-technology.

Dual-sensing porphyrin-containing copolymer nanosensor as full-spectrum colorimeter and ultra-sensitive thermometer.

Science.gov (United States)

Yan, Qiang; Yuan, Jinying; Kang, Yan; Cai, Zhinan; Zhou, Lilin; Yin, Yingwu

2010-04-28

A porphyrin-containing copolymer has dual-sensing in response to metal ions and temperature as a novel nanosensor. Triggered by ions, the sensor exhibits full-color tunable behavior as a cationic detector and colorimeter. Responding to temperature, the sensor displays an "isothermal" thermochromic point as an ultra-sensitive thermometer.

Comparative study of donor-induced quantum dots in Si nano-channels by single-electron transport characterization and Kelvin probe force microscopy

International Nuclear Information System (INIS)

Tyszka, K.; Moraru, D.; Samanta, A.; Mizuno, T.; Tabe, M.; Jabłoński, R.

2015-01-01

We comparatively study donor-induced quantum dots in Si nanoscale-channel transistors for a wide range of doping concentration by analysis of single-electron tunneling transport and surface potential measured by Kelvin probe force microscopy (KPFM). By correlating KPFM observations of donor-induced potential landscapes with simulations based on Thomas-Fermi approximation, it is demonstrated that single-electron tunneling transport at lowest gate voltages (for smallest coverage of screening electrons) is governed most frequently by only one dominant quantum dot, regardless of doping concentration. Doping concentration, however, primarily affects the internal structure of the quantum dot. At low concentrations, individual donors form most of the quantum dots, i.e., “donor-atom” quantum dots. In contrast, at high concentrations above metal-insulator transition, closely placed donors instead of individual donors form more complex quantum dots, i.e., “donor-cluster” quantum dots. The potential depth of these “donor-cluster” quantum dots is significantly reduced by increasing gate voltage (increasing coverage of screening electrons), leading to the occurrence of multiple competing quantum dots

Dissociation Pathways of Benzylpyridinium "Thermometer" Ions Depend on the Activation Regime: An IRMPD Spectroscopy Study

NARCIS (Netherlands)

Morsa, D.; Gabelica, V.; Rosu, F.; Oomens, J.; De Pauw, E.

2014-01-01

The dissociation of benzylpyridinium "thermometer" ions is widely used to calibrate the internal energy of ions produced in mass spectrometry. The fragmentation mechanism is usually believed to yield a benzylium cation, although recent studies suggest the possibility of a rearrangement leading to

Closed-looped in situ nano processing on a culturing cell using an inverted electron beam lithography system

International Nuclear Information System (INIS)

Hoshino, Takayuki; Mabuchi, Kunihiko

2013-01-01

Highlights: ► An electron beam lithography (EBL) was used as an in situ nano processing for a living cell. ► A synchronized optics was containing an inverted EBL and an optical microscope. ► This system visualized real-time images of the EB-induced nano processing. ► We demonstrated the nano processing for a culturing cell with 200–300 nm resolution. ► Our system would be able to provide high resolution display of virtual environments. -- Abstract: The beam profile of an electron beam (EB) can be focused onto less than a nanometer spot and scanned over a wide field with extremely high speed sweeping. Thus, EB is employed for nano scale lithography in applied physics research studies and in fabrication of semiconductors. We applied a scanning EB as a control system for a living cell membrane which is representative of large scale complex systems containing nanometer size components. First, we designed the opposed co-axial dual optics containing inverted electron beam lithography (I-EBL) system and a fluorescent optical microscope. This system could provide in situ nano processing for a culturing living cell on a 100-nm-thick SiN nanomembrane, which was placed between the I-EBL and the fluorescent optical microscope. Then we demonstrated the EB-induced chemical direct nano processing for a culturing cell with hundreds of nanometer resolution and visualized real-time images of the scanning spot of the EB-induced luminescent emission and chemical processing using a high sensitive camera mounted on the optical microscope. We concluded that our closed-loop in situ nano processing would be able to provide a nanometer resolution display of virtual molecule environments to study functional changes of bio-molecule systems

Measurement of body temperature in 300 dogs with a novel noncontact infrared thermometer on the cornea in comparison to a standard rectal digital thermometer.

Science.gov (United States)

Kreissl, Hannah; Neiger, Reto

2015-01-01

To assess the accuracy of obtaining body temperatures in dogs with a noncontact infrared thermometer (NCIT) on the cornea compared with a rectal digital thermometer (RDT). Prospective single center study. University teaching hospital. Three hundred dogs presented with low, normal, or high body temperatures. Three body temperature readings were measured by an RDT and by an NCIT on the cornea of the left eye by 2 investigators (experienced and inexperienced). Results obtained by the 2 methods were compared. Median body temperature measured by the experienced investigator with the RDT and the NCIT were 38.3°C (range 35.5°C-41.1°C; 95% CI: 38.2-38.4°C) and 37.7°C (35.9°C-40.1°C; 95% CI: 37.7°C-37.9°C), respectively. Measurement of RDT as well as of NCIT correlated well between both investigators (rRDT = 0.94; rNCIT = 0.82; respectively, P temperature correlated poorly (r = 0.43; P temperature >39.0°C) showed an area under the curve of 0.76. Mean discomfort score was significantly lower using NCIT compared to RDT measurement (P temperatures obtained by RDT and NCIT. The corneal NCIT measurement tends to underrecognize hypothermic and hyperthermic conditions. Although the use of the NCIT yields faster results and is significantly more comfortable for the dog than the RDT measurement, it cannot be recommended in dogs at this time. © Veterinary Emergency and Critical Care Society 2015.

Full-field x-ray nano-imaging at SSRF

Science.gov (United States)

Deng, Biao; Ren, Yuqi; Wang, Yudan; Du, Guohao; Xie, Honglan; Xiao, Tiqiao

2013-09-01

Full field X-ray nano-imaging focusing on material science is under developing at SSRF. A dedicated full field X-ray nano-imaging beamline based on bending magnet will be built in the SSRF phase-II project. The beamline aims at the 3D imaging of the nano-scale inner structures. The photon energy range is of 5-14keV. The design goals with the field of view (FOV) of 20μm and a spatial resolution of 20nm are proposed at 8 keV, taking a Fresnel zone plate (FZP) with outermost zone width of 25 nm. Futhermore, an X-ray nano-imaging microscope is under developing at the SSRF BL13W beamline, in which a larger FOV will be emphasized. This microscope is based on a beam shaper and a zone plate using both absorption contrast and Zernike phase contrast, with the optimized energy set to 10keV. The detailed design and the progress of the project will be introduced.

Nano technology

International Nuclear Information System (INIS)

Lee, In Sik

2002-03-01

This book is introduction of nano technology, which describes what nano technology is, alpha and omega of nano technology, the future of Korean nano technology and human being's future and nano technology. The contents of this book are nano period is coming, a engine of creation, what is molecular engineering, a huge nano technology, technique on making small things, nano materials with exorbitant possibility, the key of nano world the most desirable nano technology in bio industry, nano development plan of government, the direction of development for nano technology and children of heart.

Kelvin probe microscopy and electronic transport measurements in reduced graphene oxide chemical sensors

Science.gov (United States)

Kehayias, Christopher E.; MacNaughton, Samuel; Sonkusale, Sameer; Staii, Cristian

2013-06-01

Reduced graphene oxide (RGO) is an electronically hybrid material that displays remarkable chemical sensing properties. Here, we present a quantitative analysis of the chemical gating effects in RGO-based chemical sensors. The gas sensing devices are patterned in a field-effect transistor geometry, by dielectrophoretic assembly of RGO platelets between gold electrodes deposited on SiO2/Si substrates. We show that these sensors display highly selective and reversible responses to the measured analytes, as well as fast response and recovery times (tens of seconds). We use combined electronic transport/Kelvin probe microscopy measurements to quantify the amount of charge transferred to RGO due to chemical doping when the device is exposed to electron-acceptor (acetone) and electron-donor (ammonia) analytes. We demonstrate that this method allows us to obtain high-resolution maps of the surface potential and local charge distribution both before and after chemical doping, to identify local gate-susceptible areas on the RGO surface, and to directly extract the contact resistance between the RGO and the metallic electrodes. The method presented is general, suggesting that these results have important implications for building graphene and other nanomaterial-based chemical sensors.

Kelvin probe microscopy and electronic transport measurements in reduced graphene oxide chemical sensors.

Science.gov (United States)

Kehayias, Christopher E; MacNaughton, Samuel; Sonkusale, Sameer; Staii, Cristian

2013-06-21

Reduced graphene oxide (RGO) is an electronically hybrid material that displays remarkable chemical sensing properties. Here, we present a quantitative analysis of the chemical gating effects in RGO-based chemical sensors. The gas sensing devices are patterned in a field-effect transistor geometry, by dielectrophoretic assembly of RGO platelets between gold electrodes deposited on SiO2/Si substrates. We show that these sensors display highly selective and reversible responses to the measured analytes, as well as fast response and recovery times (tens of seconds). We use combined electronic transport/Kelvin probe microscopy measurements to quantify the amount of charge transferred to RGO due to chemical doping when the device is exposed to electron-acceptor (acetone) and electron-donor (ammonia) analytes. We demonstrate that this method allows us to obtain high-resolution maps of the surface potential and local charge distribution both before and after chemical doping, to identify local gate-susceptible areas on the RGO surface, and to directly extract the contact resistance between the RGO and the metallic electrodes. The method presented is general, suggesting that these results have important implications for building graphene and other nanomaterial-based chemical sensors.

ANALYSIS OF THE ELECTROPHYSICAL AND PHOTOELECTRIC PROPERTIES OF NANOCOMPOSITE POLYMERS BY THE MODIFIED KELVIN PROBE

Directory of Open Access Journals (Sweden)

K. U. Pantsialeyeu

2017-01-01

Full Text Available At present for analysis of the homogeneity of materials properties are becoming widely used various modifications of a scanning Kelvin probe. These methods allow mapping the spatial distribution of the electrostatic potential. Analysis of the electropotential profile is not sufficient to describe any specific physical parameters of the polymer nanocomposites. Therefore, we use an external energy impact, such as light. Purpose of paper is the modification of the Kelvin scanning probe and the conduct of experimental studies of the spatial distribution and response of the electrostatic potential of the actual polymer nanocomposites to the optical probing.Carried out the investigations on experimental Low density polyethylene composites. Carbon nanomaterials and nanoparticles of silicon dioxide or aluminum as fillers are used. As a result, maps of the spatial distribution of the electrostatic potential relative values and the surface photovoltage. Statistical analysis of the electrophysical and photoelectric properties homogeneity, depending on the component composition of the composites carried out. In addition, with reference to matrix polymers, the Kelvin scanning probe, in combination with the optical probing, made it possible to detect a piezoelectric effect. The latter, can used as a basis for the development of new methods for studying the mechanical properties of matrix polymers.

X-ray specular reflection and fluorescence study of nano-films

International Nuclear Information System (INIS)

Zheludeva, S.; Novikova, N.

2001-01-01

The techniques that combine the advantages of high-resolution structure sensitive x-ray methods with spectroscopic selectivity of data obtained are shown to be extremely promising for characterization of organic and inorganic nano films and nano structures. Fluorescence yield angular dependences exited by complicated evanescent wave / x-ray standing wave pattern at total reflection and glancing incidence can be used to detect structure position of different ions in organic systems and alien interfacial layers in inorganic multilayers;, to get information about interdiffusion at the interfaces of Langmuir- Blodgett (L-B) films and artificial inorganic - x-ray mirrors; to study ion permeation through L-B nano structures - models of biomembrans; to obtain nano - film thickness and density; to get precisely the parameters of small d-space multilayer mirrors, ets

Time-Lapse and Slow-Motion Tracking of Temperature Changes: Response Time of a Thermometer

Science.gov (United States)

Moggio, L.; Onorato, P.; Gratton, L. M.; Oss, S.

2017-01-01

We propose the use of a smartphone based time-lapse and slow-motion video techniques together with tracking analysis as valuable tools for investigating thermal processes such as the response time of a thermometer. The two simple experimental activities presented here, suitable also for high school and undergraduate students, allow one to measure…

The SAO and Kelvin waves in the EuroGRIPS GCMS and the UK Met. Office analyses

Directory of Open Access Journals (Sweden)

M. Amodei

Full Text Available We compare the tropical oscillations and planetary scale Kelvin waves in four troposphere-stratosphere climate models and the assimilated dataset produced by the United Kingdom Meteorological Office (UKMO. The comparison has been made in the GRIPS framework "GCM-Reality Intercomparison Project for SPARC", where SPARC is Stratospheric Processes and their Role in Climate, a project of the World Climate Research Program. The four models evaluated are European members of GRIPS: the UKMO Unified Model (UM, the model of the Free University in Berlin (FUB–GCM, the ARPEGE-climat model of the French National Centre for Meteorological Research (CNRM, and the Extended UGAMP GCM (EUGCM of the Centre for Global Atmospheric Modelling (CGAM. The integrations were performed with different, but annually periodic external conditions (e.g., sea-surface temperature, sea ice, and incoming solar radiation. The structure of the tropical winds and the strengths of the Kelvin waves are examined. In the analyses where the SAO (Semi-Annual Oscillation and the QBO (Quasi-Biennal Oscillation are reasonably well captured, the amplitude of these analysed Kelvin waves is close to that observed in independent data from UARS (Upper Atmosphere Research Satellite. In agreement with observations, the Kelvin waves generated in the models propagate into the middle atmosphere as wave packets, consistent with a convective forcing origin. In three of the models, slow Kelvin waves propagate too high and their amplitudes are overestimated in the upper stratosphere and in the mesosphere, the exception is the UM which has weaker waves. None of the modelled waves are sufficient to force realistic eastward phases of the QBO or SAO. Although the SAO is represented by all models, only two of them are able to generate westerlies between 10 hPa and 50 hPa. The importance of the role played in the SAO by unresolved gravity waves is emphasized. Although it exhibits some unrealistic features, the

The SAO and Kelvin waves in the EuroGRIPS GCMS and the UK Met. Office analyses

Directory of Open Access Journals (Sweden)

M. Amodei

2001-01-01

Full Text Available We compare the tropical oscillations and planetary scale Kelvin waves in four troposphere-stratosphere climate models and the assimilated dataset produced by the United Kingdom Meteorological Office (UKMO. The comparison has been made in the GRIPS framework "GCM-Reality Intercomparison Project for SPARC", where SPARC is Stratospheric Processes and their Role in Climate, a project of the World Climate Research Program. The four models evaluated are European members of GRIPS: the UKMO Unified Model (UM, the model of the Free University in Berlin (FUB–GCM, the ARPEGE-climat model of the French National Centre for Meteorological Research (CNRM, and the Extended UGAMP GCM (EUGCM of the Centre for Global Atmospheric Modelling (CGAM. The integrations were performed with different, but annually periodic external conditions (e.g., sea-surface temperature, sea ice, and incoming solar radiation. The structure of the tropical winds and the strengths of the Kelvin waves are examined. In the analyses where the SAO (Semi-Annual Oscillation and the QBO (Quasi-Biennal Oscillation are reasonably well captured, the amplitude of these analysed Kelvin waves is close to that observed in independent data from UARS (Upper Atmosphere Research Satellite. In agreement with observations, the Kelvin waves generated in the models propagate into the middle atmosphere as wave packets, consistent with a convective forcing origin. In three of the models, slow Kelvin waves propagate too high and their amplitudes are overestimated in the upper stratosphere and in the mesosphere, the exception is the UM which has weaker waves. None of the modelled waves are sufficient to force realistic eastward phases of the QBO or SAO. Although the SAO is represented by all models, only two of them are able to generate westerlies between 10 hPa and 50 hPa. The importance of the role played in the SAO by unresolved gravity waves is emphasized. Although it exhibits some unrealistic features, the

Controlling the near-field excitation of nano-antennas with phase-change materials.

Science.gov (United States)

Kao, Tsung Sheng; Chen, Yi Guo; Hong, Ming Hui

2013-01-01

By utilizing the strongly induced plasmon coupling between discrete nano-antennas and quantitatively controlling the crystalline proportions of an underlying Ge2Sb2Te5 (GST) phase-change thin layer, we show that nanoscale light localizations in the immediate proximity of plasmonic nano-antennas can be spatially positioned. Isolated energy hot-spots at a subwavelength scale can be created and adjusted across the landscape of the plasmonic system at a step resolution of λ/20. These findings introduce a new approach for nano-circuitry, bio-assay addressing and imaging applications.

CFD simulation of Kelvin-Helmholtz instability

International Nuclear Information System (INIS)

Strubelj, L.; Tiselj, I.

2005-01-01

Kelvin-Helmholtz instability appears in stratified two-fluid flow at surface. When the relative velocity is higher than the critical relative velocity, the growth of waves occurs. The experiment of Thorpe [1] used as a benchmark in the present paper, is made in a rectangular glass tube filled with two immiscible fluids of various densities. We simulated the growth of instability with CFX-5.7 code and compared simulation with analytical solution. It was found that surface tension force, which stabilizes growth of waves, actually has a destabilizing effect in simulation, unless very small timestep and residual is used. In CFX code system of nonlinear Navier-Stokes equations is linearised and solved iterative in each timestep, until prescribed residual is achieved. On the other hand, simulation without surface tension force is more stable than analytical result predicts. (author)

Modified Kelvin Equations for Capillary Condensation in Narrow and Wide Grooves

Science.gov (United States)

Malijevský, Alexandr; Parry, Andrew O.

2018-03-01

We consider the location and order of capillary condensation transitions occurring in deep grooves of width L and depth D . For walls that are completely wet by liquid (contact angle θ =0 ) the transition is continuous and its location is not sensitive to the depth of the groove. However, for walls that are partially wet by liquid, where the transition is first order, we show that the pressure at which it occurs is determined by a modified Kelvin equation characterized by an edge contact angle θE describing the shape of the meniscus formed at the top of the groove. The dependence of θE on the groove depth D relies, in turn, on whether corner menisci are formed at the bottom of the groove in the low density gaslike phase. While for macroscopically wide grooves these are always present when θ condensation transition is different depending on whether the contact angle is greater or less than a universal value θ*≈31 °. Our arguments are supported by detailed microscopic density functional theory calculations that show that the modified Kelvin equation remains highly accurate even when L and D are of the order of tens of molecular diameters.

The Fourier-Kelvin Stellar Interferometer (FKSI): Infrared Detection and Characterization of Exozodiacal Dust to Super-Earths, A Progress Report

Science.gov (United States)

Danchi, W.

2010-01-01

The Fourier-Kelvin Stellar Interferometer (FKSI) is a structurally connected infrared space interferometer with 0.5 m diameter telescopes on a 12.5 m baseline, and is passively cooled to approx.60K. The FKSI operates in the thermal infrared from 3-8 microns in a nulling (or starlight suppressing) mode for the detection and characterization of exoplanets, debris disks, extrasolar zodiacal dust levels. The FKSI will have the highest angular resolution of any infrared space instrument ever made with its nominal resolution of 40 mas at a 5 micron center wavelength. This resolution exceeds that of Spitzer by a factor of 38 and JWST by a factor of 5. The FKSI mission is conceived as a "probe class" or "mid-sized" strategic mission that utilizes technology advances from flagship projects like JWST, SIM, Spitzer, and the technology programs of TPF-I/Darwin. During the past year we began investigating an enhanced version of FKSI with 1-2 m diameter telescopes, passively cooled to 40K, on a 20-m baseline, with a sunshade giving a +/- 45 degree Field-of-Regard. This enhanced design is capable of detecting and characterizing the atmospheres of many 2 Earth-radius super-Earths and a few Earth-twins. We will report progress on the design of the enhanced mission concept and current status of the technologies needed for this mission.

Nano Materials

International Nuclear Information System (INIS)

Jin, In Ju; Lee, Ik Mo; Kwon, Yeung Gu

2006-02-01

This book introduces background of nano science such as summary, plenty room at the bottom, access way to nano technique, nanoparticles using bottom-up method which are a marvel of nature, and modern alchemy : chemical synthesis of artificial nano structure, understanding of quantum mechanics, STM/AFM, nano metal powder, ceramic nanoparticles, nano structure film, manufacture of nanoparticles using reverse micelle method, carbon nano tube, sol-gel material, nano energy material, nano catalyst nano bio material technology and spintronics.

Nano-technology and nano-toxicology

OpenAIRE

Maynard, Robert L.

2012-01-01

Rapid developments in nano-technology are likely to confer significant benefits on mankind. But, as with perhaps all new technologies, these benefits are likely to be accompanied by risks, perhaps by new risks. Nano-toxicology is developing in parallel with nano-technology and seeks to define the hazards and risks associated with nano-materials: only when risks have been identified they can be controlled. This article discusses the reasons for concern about the potential effects on health of ...

Development of SBR-Nano clay Composites with Epoxidized Natural Rubber as Compatibilizer

International Nuclear Information System (INIS)

Rajasekar, R.; Das, Ch.K.; Gert Heinrich, G.; Das, A.

2009-01-01

The significant factor that determines the improvement of properties in rubber by the incorporation of nano clay is its distribution in the rubber matrix. The simple mixing of nonpolar rubber and organically modified nano clay will not contribute for the good dispersion of nano filler in the rubbery matrix. Hence a polar rubber like epoxidized natural rubber (ENR) can be used as a compatibilizer in order to obtain a better dispersion of the nano clay in the matrix polymer. Epoxidized natural rubber and organically modified nano clay composites (EC) were prepared by solution mixing. The nano clay employed in this study is Cloisite 20A. The obtained nano composites were incorporated in styrene butadiene-rubber (SBR) compounds with sulphur as a curing agent. The morphology observed through X-ray diffraction (XRD) and high-resolution transmission electron microscopy (HR-TEM) shows that the nano clay is highly intercalated in ENR, and further incorporation of EC in SBR matrix leads to partial exfoliation of the nano clay. Dynamic mechanical thermal analysis showed an increase in storage modulus and lesser damping characteristics for the compounds containing EC loading in SBR matrix. In addition, these compounds showed improvement in the mechanical properties.

Nano-imaging of single cells using STIM

Energy Technology Data Exchange (ETDEWEB)

Ren Minqin [Centre for Ion Beam Applications (CIBA), Department of Physics, National University of Singapore, Singapore 117542 (Singapore); Department of Biochemistry, National University of Singapore (Singapore); Kan, J.A. van [Centre for Ion Beam Applications (CIBA), Department of Physics, National University of Singapore, Singapore 117542 (Singapore); Bettiol, A.A. [Centre for Ion Beam Applications (CIBA), Department of Physics, National University of Singapore, Singapore 117542 (Singapore); Daina, Lim [Department of Anatomy, National University of Singapore (Singapore); Gek, Chan Yee [Department of Anatomy, National University of Singapore (Singapore); Huat, Bay Boon [Department of Anatomy, National University of Singapore (Singapore); Whitlow, H.J. [Department of Physics, University of Jyvaskyla, P.O. Box 35 (YFL), FIN-40014 (Finland); Osipowicz, T. [Centre for Ion Beam Applications (CIBA), Department of Physics, National University of Singapore, Singapore 117542 (Singapore); Watt, F. [Centre for Ion Beam Applications (CIBA), Department of Physics, National University of Singapore, Singapore 117542 (Singapore)]. E-mail: phywattf@nus.edu.sg

2007-07-15

Scanning transmission ion microscopy (STIM) is a technique which utilizes the energy loss of high energy (MeV) ions passing through a sample to provide structural images. In this paper, we have successfully demonstrated STIM imaging of single cells at the nano-level using the high resolution capability of the proton beam writing facility at the Centre for Ion Beam Applications, National University of Singapore. MCF-7 breast cancer cells (American Type Culture Collection [ATCC]) were seeded on to silicon nitride windows, backed by a Hamamatsu pin diode acting as a particle detector. A reasonable contrast was obtained using 1 MeV protons and excellent contrast obtained using 1 MeV alpha particles. In a further experiment, nano-STIM was also demonstrated using cells seeded on to the pin diode directly, and high quality nano-STIM images showing the nucleus and multiple nucleoli were extracted before the detector was significantly damaged.

Kelvin Notation for Stabilizing Elastic-Constant Inversion Notation Kelvin pour stabiliser l'inversion de constantes élastiques

Directory of Open Access Journals (Sweden)

Dellinger J.

2006-12-01

Full Text Available Inverting a set of core-sample traveltime measurements for a complete set of 21 elastic constants is a difficult problem. If the 21 elastic constants are directly used as the inversion parameters, a few bad measurements or an unfortunate starting guess may result in the inversion converging to a physically impossible solution . Even given perfect data, multiple solutions may exist that predict the observed traveltimes equally well. We desire the inversion algorithm to converge not just to a physically possible solution, but to the best(i. e. most physically likely solution of all those allowed. We present a new parameterization that attempts to solve these difficulties. The search space is limited to physically realizable media by making use of the Kelvin eigenstiffness-eigentensor representation of the 6 x 6 elastic stiffness matrix. Instead of 21 stiffnesses, there are 6 eigenstiffness parametersand 15 rotational parameters . The rotational parameters are defined using a Lie-algebra representation that avoids the artificial degeneracies and coordinate-system bias that can occur with standard polar representations. For any choice of these 21 real parameters, the corresponding stiffness matrix is guaranteed to be physically realizable. Furthermore, all physically realizable matrices can be represented in this way. This new parameterization still leaves considerable latitude as to which linear combinations of the Kelvin parameters to use, and how they should be ordered. We demonstrate that by careful choice and ordering of the parameters, the inversion can be relaxedfrom higher to lower symmetry simply by adding a few more parameters at a time. By starting from isotropy and relaxing to the general result in stages (isotropy, transverse isotropy, orthorhombic, general, we expect that the method should find the solution that is closest to isotropy of all those that fit the data. L'inversion d'un ensemble de mesures du temps de parcours d

The distress thermometer in survivors of gynaecological cancer

DEFF Research Database (Denmark)

Olesen, Mette L.; Hansen, Merete K.; Hansson, Helena

2017-01-01

Purpose: Unrecognised psychological distress among cancer survivors may be identified using short screening tools. We validated the accuracy of the distress thermometer (DT) to detect psychological distress on the Hospital Anxiety and Depression Scale (HADS) among early stage gynaecological cancer...... survivors and whether the women’s DT and HADS scores were associated with the need of an individualised supportive intervention. Methods: One hundred sixty-five gynaecological cancer survivors answered DT and HADS before randomisation in a trial testing a nurse-led, person-centred intervention using...... supportive conversations. The number of conversations was decided in the woman-nurse dyad based on the woman’s perceived need. Nurses were unaware of the women’s DT and HADS scores. We validated DT’s accuracy for screening using HADS as gold standard and receiver operating characteristic curves. Associations...

Carbon nano tubes embedded in polymer nano fibers

International Nuclear Information System (INIS)

Dror, Y.; Kedem, S.; Khalfin, R.L.; Paz, Y.; Cohenl, Y.; Salalha, Y.; Yarin, A.L.; Zussman, A.

2004-01-01

Full Text: The electro spinning process was used successfully to embed Multi-walled carbon nano tubes (MWCNTs) and single-walled carbon nano tubes (SWCNTs) in a matrix of poly(ethylene oxide) (PEO) forming composite nano fibers. Initial dispersion of SWCNTs in water was achieved by the use of an amphphilic alternating copolymer of styrene and sodium maleate. MWNT dispersion was achieved by ionic and nonionic surfactants. The distribution and conformation of the nano tubes in the nano fibers were studied by transmission electron microscopy (TEM). Oxygen plasma etching was used to expose the nano tubes within the nano fibers to facilitate direct observation. Nano tube alignment within the nano fibers was shown to depend strongly on the quality of the initial dispersions. Well-dispersed and separated nano tubes were embedded in a straight and aligned form while entangled non-separated nano tubes were incorporated as dense aggregates. X-ray diffraction demonstrated a high degree of orientation of the PEO crystals in the electro spun nano fibers with embedded SWCNTs, whereas incorporation of MVCNTs had a detrimental effect on the polymer orientation. Composite polymer nano fibers containing dispersed phases of nanometric TiO 2 particles and MWCNTs were also prepared electro spinning. In this case, the polymer matrix was poly(acrylonitrile) (PAN). The morphology and possible applications of these composite nano fibers will be discussed

Nano Mechanical Machining Using AFM Probe

Science.gov (United States)

Mostofa, Md. Golam

Complex miniaturized components with high form accuracy will play key roles in the future development of many products, as they provide portability, disposability, lower material consumption in production, low power consumption during operation, lower sample requirements for testing, and higher heat transfer due to their very high surface-to-volume ratio. Given the high market demand for such micro and nano featured components, different manufacturing methods have been developed for their fabrication. Some of the common technologies in micro/nano fabrication are photolithography, electron beam lithography, X-ray lithography and other semiconductor processing techniques. Although these methods are capable of fabricating micro/nano structures with a resolution of less than a few nanometers, some of the shortcomings associated with these methods, such as high production costs for customized products, limited material choices, necessitate the development of other fabricating techniques. Micro/nano mechanical machining, such an atomic force microscope (AFM) probe based nano fabrication, has, therefore, been used to overcome some the major restrictions of the traditional processes. This technique removes material from the workpiece by engaging micro/nano size cutting tool (i.e. AFM probe) and is applicable on a wider range of materials compared to the photolithographic process. In spite of the unique benefits of nano mechanical machining, there are also some challenges with this technique, since the scale is reduced, such as size effects, burr formations, chip adhesions, fragility of tools and tool wear. Moreover, AFM based machining does not have any rotational movement, which makes fabrication of 3D features more difficult. Thus, vibration-assisted machining is introduced into AFM probe based nano mechanical machining to overcome the limitations associated with the conventional AFM probe based scratching method. Vibration-assisted machining reduced the cutting forces

Internal Morphologies of Cycled Li-Metal Electrodes Investigated by Nano-Scale Resolution X-ray Computed Tomography.

Science.gov (United States)

Frisco, Sarah; Liu, Danny X; Kumar, Arjun; Whitacre, Jay F; Love, Corey T; Swider-Lyons, Karen E; Litster, Shawn

2017-06-07

While some commercially available primary batteries have lithium metal anodes, there has yet to be a commercially viable secondary battery with this type of electrode. Research prototypes of these cells typically exhibit a limited cycle life before dendrites form and cause internal cell shorting, an occurrence that is more pronounced during high-rate cycling. To better understand the effects of high-rate cycling that can lead to cell failure, we use ex situ nanoscale-resolution X-ray computed tomography (nano-CT) with the aid of Zernike phase contrast to image the internal morphologies of lithium metal electrodes on copper wire current collectors that have been cycled at low and high current densities. The Li that is deposited on a Cu wire and then stripped and deposited at low current density appears uniform in morphology. Those cycled at high current density undergo short voltage transients to >3 V during Li-stripping from the electrode, during which electrolyte oxidation and Cu dissolution from the current collector may occur. The effect of temperature is also explored with separate cycling experiments performed at 5 and 33 °C. The resulting morphologies are nonuniform films filled with voids that are semispherical in shape with diameters ranging from hundreds of nanometers to tens of micrometers, where the void size distributions are temperature-dependent. Low-temperature cycling elicits a high proportion of submicrometer voids, while the higher-temperature sample morphology is dominated by voids larger than 2 μm. In evaluating these morphologies, we consider the importance of nonidealities during extreme charging, such as electrolyte decomposition. We conclude that nano-CT is an effective tool for resolving features and aggressive cycling-induced anomalies in Li films in the range of 100 nm to 100 μm.

Characterization of nano-textured samples in a production environment

DEFF Research Database (Denmark)

Madsen, Morten Hannibal; Hansen, Poul-Erik; Bilenberg, Brian

2015-01-01

, such as a machine floor. The acquisition and analysing time for the topological parameters height, width and sidewall angle is only a few milliseconds. It is demonstrated that by simple adaptions to an optical microscope we can measure nano-textured surfaces with an uncertainty of a few nanometers for the height......Nano-textured surfaces have been characterized by optical diffraction techniques using an adapted commercial light microscope with two detectors, a CCD camera and a spectrometer. We demonstrate that the microscope has a resolution in the nanometer range, also in an environment with many vibrations...

Equatorial Kelvin Waves Observed with GPS Occultation Measurements : CHAMP and SAC-C (2.Space-Borne GPS Meteorology and Related Techniques)

OpenAIRE

Ho-Fang, TSAI; Toshitaka, TSUDA; George A., HAJJ; Jens, WICKERT; Yuichi, AOYAMA; Radio Science Center for Space and Atmosphere (RASC), Kyoto University :National Space Program Office(NSPO); Radio Science Center for Space and Atmosphere (RASC), Kyoto University; Jet Propulsion Laboratory (JPL), California Institute of Technology; GeoForschungsZentrum Potsdam (GFZ), Department 1:Geodesy and Remote Sensing; RASC, Kyoto University

2004-01-01

Structure and propagation of equatorial Kelvin waves during May 2001 and December 2002 are observed from the temperature profiles in the upper troposphere and the lower stratosphere using CHAMP and SAC-C GPS radio occultation data. Kelvin waves derived from temperature fluctuations characterize eastward phase propagation in time-longitude section and eastward phase tilts with height in altitude-longitude section between 10 and 30 km. The phase progression spans the range indicating the contin...

Determination of response time of resistance thermometers by in situ measurements

International Nuclear Information System (INIS)

Goncalves, I.M.P.; Soares, A.J.

1986-01-01

The loop-current-step-response test provides a mean for determining the time constant of resistance thermometers. The test consists in heating the sensor a few degrees above ambient temperature by causing a step perurbation in the electric current that flows through the sensor leads. The developed mathematical transformation permits to use data collected during the internal heating transient to predict the sensor response to perturbations in fluid temperature. Experimental data obtained show that time constant determined by this method is within 15 percent of the true value. (Author) [pt

A sounding rocket payload for X-ray astronomy employing high-resolution microcalorimeters

International Nuclear Information System (INIS)

McCammon, D.; Almy, R.; Deiker, S.; Morgenthaler, J.; Kelley, R.L.; Marshall, F.J.; Moseley, S.H.; Stahle, C.K.; Szymkowiak, A.E.

1996-01-01

We have completed a sounding rocket payload that will use a 36 element array of microcalorimeters to obtain a high-resolution spectrum of the diffuse X-ray background between 0.1 and 1 keV. This experiment uses only mechanical collimation of the incoming X-rays, but the cryostat and detector assembly have been designed to be placed at the focus of a conical foil imaging mirror which will be employed on subsequent flights to do spatially resolved spectroscopy of supernova remnants and other extended objects. The detector system is a monolithic array of silicon calorimeters with ion-implanted thermometers and HgTe X-ray absorbers. The 1 mm 2 pixels achieve a resolution of about 8 eV FWHM operating at 60 mK. (orig.)

Nano-optical conveyor belt with waveguide-coupled excitation.

Science.gov (United States)

Wang, Guanghui; Ying, Zhoufeng; Ho, Ho-pui; Huang, Ying; Zou, Ningmu; Zhang, Xuping

2016-02-01

We propose a plasmonic nano-optical conveyor belt for peristaltic transport of nano-particles. Instead of illumination from the top, waveguide-coupled excitation is used for trapping particles with a higher degree of precision and flexibility. Graded nano-rods with individual dimensions coded to have resonance at specific wavelengths are incorporated along the waveguide in order to produce spatially addressable hot spots. Consequently, by switching the excitation wavelength sequentially, particles can be transported to adjacent optical traps along the waveguide. The feasibility of this design is analyzed using three-dimensional finite-difference time-domain and Maxwell stress tensor methods. Simulation results show that this system is capable of exciting addressable traps and moving particles in a peristaltic fashion with tens of nanometers resolution. It is the first, to the best of our knowledge, report about a nano-optical conveyor belt with waveguide-coupled excitation, which is very important for scalability and on-chip integration. The proposed approach offers a new design direction for integrated waveguide-based optical manipulation devices and its application in large scale lab-on-a-chip integration.

Application of scanning Kelvin probe microscopy for the electrical characterization of microcrystalline silicon for photovoltaics

International Nuclear Information System (INIS)

Breymesser, A.

2000-05-01

In the last years microcrystalline silicon thin films have attracted great attention as a new photovoltaic material. With this material it is possible to combine simple and cheap low temperature deposition techniques known from amorphous silicon with the long-term stability of the photovoltaic performance like in bulk crystalline silicon solar cells. The critical point is the deposition procedure with numerous tunable parameters influencing the quality and character of the produced diode structures. Additionally there is a great uncertainty about unintentionally incorporated defects, which is not affected by the deposition parameters. Extended investigation of the material, diode and solar cell characteristics is essential in order to correlate the impact of deposition conditions with the quality of the devices. The situation is complicated due to the anisotropic and inhomogeneous character of microcrystalline silicon. Scanning Kelvin probe microscopy (SKPM) is a work function measurement method based on a scanning force microscope (SFM) and a modified Kelvin probe technique. Due to the excellent lateral resolution of the SFM work function measurements with resolutions far below the micrometer level can be carried out. Applied on doped microcrystalline silicon structures it is possible to visualize the position of the Fermi level within the band gap and the influence of the deposition conditions on it. Within this work a SKPM based on a commercially available SFM was constructed and built. Great effort was concentrated on the characterization of the SKPM experiment. On the basis of an extended knowledge about the performance investigations concentrated on cross sections of microcrystalline silicon diode structures produced by hot-wire chemical vapor deposition (HW-CVD). A pin structure for the diodes was chosen due to the low diffusion lengths within this rather defective material. The evolution of the built-in electric drift field within the intrinsic absorber is

Density-space potential phase difference in a Kelvin--Helmholtz instability

International Nuclear Information System (INIS)

Glowienka, J.C.; Jennings, W.C.; Hickok, R.L.

1974-01-01

The low-frequency instability found in a hollow cathode discharge in helium was studied using an ion beam probe as a primary diagnostic tool. Three aspects of the instability are discussed: the location and amplitude of the oscillation and its correlation with the shape of the space potential; the phase angle between density and space potential oscillations; and the comparison of the data with three known instability models: Kelvin--Helmholtz, Rayleigh--Taylor, and drift waves--for mode identification. (U.S.)

Bio-inspired nano-photodiode for Low Light, High Resolution and crosstalk-free CMOS image sensing

KAUST Repository

Saffih, Faycal

2011-05-01

Previous attempts have been devoted to mimic biological vision intelligence at the architectural system level. In this paper, a novel imitation of biological visual system intelligence is suggested, at the device level with the introduction of novel photodiode morphology. The proposed bio-inspired nanorod photodiode puts the depletion region length on the path of the incident photon instead of on its width, as the case is with the planar photodiodes. The depletion region has a revolving volume to increase the photodiode responsivity, and thus its photosensitivity. In addition, it can virtually boost the pixel fill factor (FF) above the 100% classical limit due to decoupling of its vertical sensing area from its limited planar circuitry area. Furthermore, the suggested nanorod photodiode photosensitivity is analytically proven to be higher than that of the planar photodiode. We also show semi-empirically that the responsivity of the suggested device varies linearly with its height; this important feature has been confirmed using Sentaurus simulation. The proposed nano-photorod is believed to meet the increasingly stringent High-Resolution-Low-Light (HRLL) detection requirements of the camera-phone and biomedical imaging markets. © 2011 IEEE.

Measuring the lateral charge-carrier mobility in metal-insulator-semiconductor capacitors via Kelvin-probe.

Science.gov (United States)

Milotti, Valeria; Pietsch, Manuel; Strunk, Karl-Philipp; Melzer, Christian

2018-01-01

We report a Kelvin-probe method to investigate the lateral charge-transport properties of semiconductors, most notably the charge-carrier mobility. The method is based on successive charging and discharging of a pre-biased metal-insulator-semiconductor stack by an alternating voltage applied to one edge of a laterally confined semiconductor layer. The charge carriers spreading along the insulator-semiconductor interface are directly measured by a Kelvin-probe, following the time evolution of the surface potential. A model is presented, describing the device response for arbitrary applied biases allowing the extraction of the lateral charge-carrier mobility from experimentally measured surface potentials. The method is tested using the organic semiconductor poly(3-hexylthiophene), and the extracted mobilities are validated through current voltage measurements on respective field-effect transistors. Our widely applicable approach enables robust measurements of the lateral charge-carrier mobility in semiconductors with weak impact from the utilized contact materials.

Measuring the lateral charge-carrier mobility in metal-insulator-semiconductor capacitors via Kelvin-probe

Science.gov (United States)

Milotti, Valeria; Pietsch, Manuel; Strunk, Karl-Philipp; Melzer, Christian

2018-01-01

We report a Kelvin-probe method to investigate the lateral charge-transport properties of semiconductors, most notably the charge-carrier mobility. The method is based on successive charging and discharging of a pre-biased metal-insulator-semiconductor stack by an alternating voltage applied to one edge of a laterally confined semiconductor layer. The charge carriers spreading along the insulator-semiconductor interface are directly measured by a Kelvin-probe, following the time evolution of the surface potential. A model is presented, describing the device response for arbitrary applied biases allowing the extraction of the lateral charge-carrier mobility from experimentally measured surface potentials. The method is tested using the organic semiconductor poly(3-hexylthiophene), and the extracted mobilities are validated through current voltage measurements on respective field-effect transistors. Our widely applicable approach enables robust measurements of the lateral charge-carrier mobility in semiconductors with weak impact from the utilized contact materials.

Tipping solutions: emerging 3D nano-fabrication/ -imaging technologies

Directory of Open Access Journals (Sweden)

Seniutinas Gediminas

2017-06-01

Full Text Available The evolution of optical microscopy from an imaging technique into a tool for materials modification and fabrication is now being repeated with other characterization techniques, including scanning electron microscopy (SEM, focused ion beam (FIB milling/imaging, and atomic force microscopy (AFM. Fabrication and in situ imaging of materials undergoing a three-dimensional (3D nano-structuring within a 1−100 nm resolution window is required for future manufacturing of devices. This level of precision is critically in enabling the cross-over between different device platforms (e.g. from electronics to micro-/nano-fluidics and/or photonics within future devices that will be interfacing with biological and molecular systems in a 3D fashion. Prospective trends in electron, ion, and nano-tip based fabrication techniques are presented.

What model resolution is required in climatological downscaling over complex terrain?

Science.gov (United States)

El-Samra, Renalda; Bou-Zeid, Elie; El-Fadel, Mutasem

2018-05-01

This study presents results from the Weather Research and Forecasting (WRF) model applied for climatological downscaling simulations over highly complex terrain along the Eastern Mediterranean. We sequentially downscale general circulation model results, for a mild and wet year (2003) and a hot and dry year (2010), to three local horizontal resolutions of 9, 3 and 1 km. Simulated near-surface hydrometeorological variables are compared at different time scales against data from an observational network over the study area comprising rain gauges, anemometers, and thermometers. The overall performance of WRF at 1 and 3 km horizontal resolution was satisfactory, with significant improvement over the 9 km downscaling simulation. The total yearly precipitation from WRF's 1 km and 3 km domains exhibited quantitative measure of the potential errors for various hydrometeorological variables.

Subharmonic frequency locking in the resistive Josephson thermometer

International Nuclear Information System (INIS)

van Veldhuizen, M.; Fowler, H.A.

1985-01-01

Phase-locked oscillatory solutions are examined as a basis for the dc impedance of the resistive superconducting quantum-interference device Josephson thermometer. The calculations are based on the resistively shunted junction model in the limit 2πL/sub s/I/sub c//Phi 0 > or =1, where L/sub s/ is the loop inductance and I/sub c/ is the junction critical current, and for a junction resistance large compared with the external shunt resistance. An algorithm for representing frequency entrainment in (kappa,ω) space (drive amplitude, frequency) leads to zones with rotation number p/q having the form of leaf-shaped regions joined and overlapping at their tips. High-resonance zones are very thin and locally similar. No chaotic behavior has been observed. The model can simulate the ''rising'' curves of dc impedance as a function of drive amplitude

Bilateral comparison for determining the dynamic characteristic values of contact thermometers in fluids

Directory of Open Access Journals (Sweden)

S. Augustin

2018-05-01

Full Text Available In applicable standards and sets of rules (VDI/VDE, 2014; DIN, 2010, 2017, recommendations are made concerning the types of experiments for determining the dynamic parameters in fluids (flowing water and flowing air under well-defined conditions. In the data sheets of the thermometer manufacturers, quite different specifications can be found, such as time percentage values or time constants. Only a few thermometer manufacturers specify the medium and flow conditions under which these parameters have been determined. Above all, it is not common practice to indicate a measurement uncertainty for the dynamic parameters found. In Augustin et al. (2017, a first model for the indication of the measurement uncertainty of dynamic parameters in flowing air was presented.The present paper describes the results of a bilateral comparison made for the first time for determining dynamic parameters in the laboratories of the JUMO GmbH & Co. KG Fulda company and at the Institute of Process Measurement and Sensor Technology of the TU Ilmenau. In doing so, two type-N thermocouples with different diameters were investigated in experimental facilities with flowing water and flowing air. Subsequently, the dynamic parameters found were compared with each other. The differences revealed mainly resulted from plant-specific parameters.

Edge Contact Angle and Modified Kelvin Equation for Condensation in Open Pores.

Czech Academy of Sciences Publication Activity Database

Malijevský, Alexandr; Parry, A.O.; Pospíšil, M.

2017-01-01

Roč. 96, č. 2 (2017), č. článku 020801. ISSN 2470-0045 R&D Projects: GA ČR(CZ) GA17-25100S Grant - others:EPSRC(GB) EP/L020564/1 Institutional support: RVO:67985858 Keywords : capillary condensation * Kelvin equation * density functional theory Subject RIV: CF - Physical ; Theoretical Chemistry OBOR OECD: Physical chemistry Impact factor: 2.366, year: 2016

Mirror profile optimization for nano-focusing KB mirror

International Nuclear Information System (INIS)

Zhang Lin; Baker, Robert; Barrett, Ray; Cloetens, Peter; Dabin, Yves

2010-01-01

A KB focusing mirror width profile has been optimized to achieve nano-focusing for the nano-imaging end-station ID22NI at the ESRF. The complete mirror and flexure bender assembly has been modeled in 3D with finite element analysis using ANSYS. Bender stiffness, anticlastic effects and geometrical non-linear effects have been considered. Various points have been studied: anisotropy and crystal orientation, stress in the mirror and bender, actuator resolution and the mirror-bender adhesive bonding... Extremely high performance of the mirror is expected with residual slope error smaller than 0.6 μrad, peak-to-valley, compared to the bent slope of 3000 μrad.

Nano-Continuum Modeling of a Nuclear Glass Specimen Altered for 25 Years

Energy Technology Data Exchange (ETDEWEB)

Steefel, Carl

2014-01-06

The purpose of this contribution is to report on preliminary nano-continuum scale modeling of nuclear waste glass corrosion. The focus of the modeling is an experiment involving a French glass SON68 specimen leached for 25 years in a granitic environment. In this report, we focus on capturing the nano-scale concentration profiles. We use a high resolution continuum model with a constant grid spacing of 1 nanometer to investigate the glass corrosion mechanisms.

A Novel SPM Probe with MOS Transistor and Nano Tip for Surface Electric Properties

International Nuclear Information System (INIS)

Lee, Sang H; Lim, Geunbae; Moon, Wonkyu

2007-01-01

In this paper, the novel SPM (Scanning Probe Microscope) probe with the planar MOS (Metal-Oxide-Semiconductor) transistor and the FIB (Focused Ion Beam) nano tip is fabricated for the surface electric properties. Since the MOS transistor has high working frequency, the device can overcome the speed limitation of EFM (Electrostatic Force Microscope) system. The sensitivity is also high, and no bulky device such as lock-in-amplifier is required. Moreover, the nano tip with nanometer scale tip radius is fabricated with FIB system, and the resolution can be improved. Therefore, the probe can rapidly detect small localized electric properties with high sensitivity and high resolution. The MOS transistor is fabricated with the common semiconductor process, and the nano tip is grown by the FIB system. The planar structure of the MOS transistor makes the fabrication process easier, which is the advantage on the commercial production. Various electric signals are applied using the function generator, and the measured data represent the well-established electric properties of the device. It shows the promising aspect of the local surface electric property detection with high sensitivity and high resolution

Characterizing the Nano and Micro Structure of Concrete toImprove its Durability

Energy Technology Data Exchange (ETDEWEB)

Monteiro, P.J.M.; Kirchheim, A.P.; Chae, S.; Fischer, Peter; MacDowell, Alastair; Schaible, Eirc; Wenk, H.R.; Macdowell, Alastair A.

2009-01-13

New and advanced methodologies have been developed to characterize the nano and microstructure of cement paste and concrete exposed to aggressive environments. High resolution full-field soft X-ray imaging in the water window is providing new insight on the nano scale of the cement hydration process, which leads to a nano-optimization of cement-based systems. Hard X-ray microtomography images of ice inside cement paste and cracking caused by the alkali?silica reaction (ASR) enables three-dimensional structural identification. The potential of neutron diffraction to determine reactive aggregates by measuring their residual strains and preferred orientation is studied. Results of experiments using these tools are shown on this paper.

Structure-mediated micro-to-nano coupling using sculpted light and matter

DEFF Research Database (Denmark)

Glückstad, Jesper; Bañas, Andrew Rafael; Aabo, Thomas

2012-01-01

The synergy between photonics, nanotechnology and biotechnology is spawning the emerging fields of nanobiotechnology and nano-biophotonics. Photonic innovations already hurdle the diffraction barrier for imaging with nanoscopic resolutions. However, scientific hypothesis testing demands tools...

NanoSIMS50 analyses of Ar/18O2 plasma-treated Escherichia coli bacteria

International Nuclear Information System (INIS)

Clément, F; Lecoq, E; Duday, D; Audinot, J-N; Lentzen, E; Penny, C; Cauchie, H-M; Choquet, P; Belmonte, T

2011-01-01

Reactive oxygen species (ROS) can be produced by electrical discharges and can be transported in uncharged regions by gas flows, in the so-called afterglows. These species are well known to have bactericidal effects but interaction mechanisms that occur with living micro-organisms remain misunderstood. In order to better understand these interactions, new analysis approaches are necessary. High-lateral-resolution secondary ion mass spectrometry (NanoSIMS) is one of the most promising ways of retrieving additional information on bacteria plasma inactivation mechanisms by combining isotopic imaging of plasma-treated bacteria and the use of 18 O 2 as process gas. Indeed, this technology combines a lateral resolution of a few tens of nanometres that is sufficient to image the interior of bacteria, and a high mass resolution allowing detection of isotopes present in low quantities (a few ppm or lower) within the bacteria. The present paper deals with Ar- 18 O 2 (2%) plasma treatment, through low-pressure microwave late afterglows, of Escherichia coli bacteria and their elemental and isotopic imaging by NanoSIMS. E. coli bacteria have been exposed to this reactive medium for varying treatment duration while keeping all other parameters unchanged. Our main goal is to determine whether the quantity of 18 O fixed in treated bacteria and the NanoSIMS50 lateral resolution are sufficient to give additional information on E. coli bacteria-plasma interaction. (paper)

Parent-Child Agreement Using the Spence Children's Anxiety Scale and a Thermometer in Children with Autism Spectrum Disorder

Science.gov (United States)

May, T.; Cornish, K.; Rinehart, N. J.

2015-01-01

Children with Autism Spectrum Disorder (ASD) experience high anxiety which often prompts clinical referral and requires intervention. This study aimed to compare parent and child reports on the Spence Children's Anxiety Scale (SCAS) and a child-reported “worry thermometer” in 88 children aged 8–13 years, 44 with ASD and 44 age, gender, and perceptual IQ matched typically developing children. There were no gender differences in child report on the SCAS and worry thermometers. Results indicated generally good correlations between parent and child self-reported SCAS symptoms for typically developing children but poor agreement in parent-child ASD dyads. The worry thermometer child-report did not reflect child or parent reports on the SCAS. Findings suggest 8–13-year-old children with ASD may have difficulties accurately reporting their anxiety levels. The clinical implications were discussed. PMID:25922765

Microstructure characterization and magnetic properties of nano structured materials

International Nuclear Information System (INIS)

Sun, X.C.

2000-01-01

The present thesis deals with the unique microstructural properties and their novel magnetic properties of core-shell Ni-Ce nano composite particles, carbon encapsulated Fe, Co, and Ni nanoparticles and the nano crystallization behavior of typical ferromagnetic Fe 78 Si 9 B 13 ribbons. These properties have intensively been investigated by high resolution transmission electron microscopy (HREM), X-ray diffraction (XRD), scanning electron microscopy (Sem), X-ray energy dispersive spectroscopy (Eds.); selected area electron diffraction pattern (SAED), Ft-IR, differential scanning calorimeter (DSC). In addition, magnetic moments measurements at different temperatures and applied fields have been performed by transmission Moessbauer spectroscopy, superconducting quantum interference device magnetometer (SQUID), and vibrating sample magnetometer (VSM). The present studies may provide the insights for the better understanding of the correlation between the unique microstructure and novel magnetic properties for several magnetic nano structured materials. (Author)

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

Science.gov (United States)

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

2009-12-01

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

Semi-transparent gold film as simultaneous surface heater and resistance thermometer for nucleate boiling studies

International Nuclear Information System (INIS)

Oker, E.; Merte, H. Jr.

1981-01-01

A large (22 x 25 mm) semi-transparent thin film of gold, approximately 400 A in thickness, is deposited on a glass substrate for simultaneous use as a heat source and resistance thermometer. Construction techniques and calibration procedures are described, and a sample application to a transient boiling process is included with simultaneous high speed photographs taken through the thin film from beneath

Lennard-Jones fluids in two-dimensional nano-pores. Multi-phase coexistence and fluid structure

Science.gov (United States)

Yatsyshin, Petr; Savva, Nikos; Kalliadasis, Serafim

2014-03-01

We present a number of fundamental findings on the wetting behaviour of nano-pores. A popular model for fluid confinement is a one-dimensional (1D) slit pore formed by two parallel planar walls and it exhibits capillary condensation (CC): a first-order phase transition from vapour to capillary-liquid (Kelvin shift). Capping such a pore at one end by a third orthogonal wall forms a prototypical two-dimensional (2D) pore. We show that 2D pores possess a wetting temperature such that below this temperature CC remains of first order, above it becomes a continuous phase transition manifested by a slab of capillary-liquid filling the pore from the capping wall. Continuous CC exhibits hysteresis and can be preceded by a first-order capillary prewetting transition. Additionally, liquid drops can form in the corners of the 2D pore (remnant of 2D wedge prewetting). The three fluid phases, vapour, capillary-liquid slab and corner drops, can coexist at the pore triple point. Our model is based on the statistical mechanics of fluids in the density functional formulation. The fluid-fluid and fluid-substrate interactions are dispersive. We analyze in detail the microscopic fluid structure, isotherms and full phase diagrams. Our findings also suggest novel ways to control wetting of nano-pores. We are grateful to the European Research Council via Advanced Grant No. 247031 for support.

Effect of cold plasma on the Kelvin-Helmholtz instability

International Nuclear Information System (INIS)

Melander, B.G.

1978-01-01

The thesis studies the effect of a two-component plasma (hot and cold) on the shear driven Kelvin-Helmholtz instability. An ion distribution with a shear flow parallel to the ambient magnetic field and a density gradient parallel to the shear direction is used. Both the electrostatic and electromagnetic versions of the instability are studied in the limit of hydromagnetic frequencies. The dispersion relation is obtained in the electrostatic case by solving the Vlasov equation for the perturbed ion and electron densities and then using the quasineutrality condition. In the electromagnetic case the coupled Vlasov and Maxwell's equations are solved to obtain the dispersion relation

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

International Nuclear Information System (INIS)

Daeinabi, Khadijeh; Korayem, Moharam Habibnejad

2011-01-01

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

The dynamics of beltramized flows and its relation with the Kelvin waves

International Nuclear Information System (INIS)

Gonzalez, Rafael; Santini, E Sergio

2011-01-01

We define the beltramized flow as the sum of an uniform translation and an uniform rotation with a Beltrami flow. Some of their features are studied by solving the Euler equations, for different geometries, taking into account the boundary conditions, and for different symmetries. We show that the Kelvin waves are beltramized flows. Finally, we show that the variational principle found in a previous work, remains valid for the beltramized flow.

The dynamics of beltramized flows and its relation with the Kelvin waves

Energy Technology Data Exchange (ETDEWEB)

Gonzalez, Rafael [Instituto de Desarrollo Humano, Universidad Nacional de General Sarmiento Pcia. de Buenos Aires, Argentina and Depto. de Fisica FCEyN, Universidad de Buenos Aires, Buenos Aires (Argentina); Santini, E Sergio, E-mail: rgonzale@ungs.edu.ar [Instituto de Ciencias, Universidad Nacional de General Sarmiento Pcia. de Buenos Aires (Argentina) and ICRA-BR, Centro Brasileiro de Pesquisas Fisicas, Rio de Janeiro (Brazil)

2011-05-01

We define the beltramized flow as the sum of an uniform translation and an uniform rotation with a Beltrami flow. Some of their features are studied by solving the Euler equations, for different geometries, taking into account the boundary conditions, and for different symmetries. We show that the Kelvin waves are beltramized flows. Finally, we show that the variational principle found in a previous work, remains valid for the beltramized flow.

Method for determining the outlet temperature of fuel assemblies unsupplied with thermometer in WWER-440 reactors

International Nuclear Information System (INIS)

Miko, S.; Kalya, Z.; Hamvas, I.

1987-09-01

The paper outlines a method for the evaluation of the outlet temperatures of fuel assemblies unsupplied with thermometer in WWER-440 reactors. The process is based on interpolation of directly measured assembly temperatures. A quantitative comparison of the errors of described algorithm to those of standard plant-computer interpolation rutine is also presented. (author)

Use of infrared thermometer technique in irrigation scheduling of pomegranate (Punica granatum L. plant

Directory of Open Access Journals (Sweden)

Begüm TEKELİOĞLU

2017-06-01

Full Text Available The main objectives of this study are to assess crop water stress index (CWSI and to determine irrigation schedule of pomegranate using infrared thermometer technique. Treatments with three replications were irrigated every three and six days intervals, as much as 0.50 (S1, 0.75 (S2, 1.00 (S3, and 1.25 (S4 of Class A pan evaporation. Additionally, an unirrigated plot was also formed. The equations obtained for non-water stress baseline is Tc-Ta=0.645VPD-4.338. The equation of full water stressed upper baseline obtained from data taken from branches of pomegranate plant cut in different days is given by Tc-Ta= 0.0489VPD+2.8734. According to the results obtained, it is concluded that infrared thermometer can be used for irrigation scheduling of the pomegranate plants in Antalya conditions. When using this technique in Antalya conditions, it is suggested to keep the seasonal mean CWSI value approximately 0.12 and the index value of 0.40 can be used to start the irrigation. Additionally, it is suggested that the amount of irrigation can be determined as much as the amount of evaporation measured until the index value reaches 0.40.

A study of cross-bridge kelvin resistor structures for reliable measurement of low contact resistances

NARCIS (Netherlands)

Stavitski, N.; Klootwijk, J.H.; van Zeijl, H.W.; Kovalgin, Alexeij Y.; Wolters, Robertus A.M.

2008-01-01

The parasitic factors that strongly influence the measurement accuracy of Cross-Bridge Kelvin Resistor (CBKR) structures for low specific contact resistances (�?c) have been extensively discussed during last few decades and the minimum of the �?c value, which could be accurately extracted, was

Thermometer by optical fiber for ampacity studies in overhead transmission lines; Termometro a fibra optica para estudo da ampacidade em linhas de transmissao aereas

Energy Technology Data Exchange (ETDEWEB)

Valente, L.C.G.; Kawase, L.R.; Silva Filho, J.I. da; Silva, J.M.M. da [Centro de Pesquisas de Energia Eletrica, Rio de Janeiro, RJ (Brazil); Igarashi, A.Y. [Universidade Federal, Rio de Janeiro, RJ (Brazil)

1995-12-31

This article suggests the utilization of thermometers constructed from optical fibers technology in overhead power transmission lines. This will help the studies in progress about the electric power systems ampacity. It also presents the advantages of using optical fibers instead of conventional thermometers. As an example, the fact that the optical fibers are dielectric and make possible the remote monitoring. It is also shown a possibility of introducing such measuring system in electric junctions where OPGW cables are used 4 refs., 4 figs.; e-mail: liliana at fis.puc-rio.br

Book Review: Nano physics & Nano technology

Directory of Open Access Journals (Sweden)

Abdolkhaled Zaree

2012-12-01

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

Characterizing the nano and micro structure of concrete to improve its durability

Energy Technology Data Exchange (ETDEWEB)

Monteiro, P.J.M.; Kirchheim, A.P.; Chae, S.; Fischer, P.; MacDowell, A.A.; Schaible, E.; Wenk, H.R.

2008-10-22

New and advanced methodologies have been developed to characterize the nano and microstructure of cement paste and concrete exposed to aggressive environments. High resolution full-field soft X-ray imaging in the water window is providing new insight on the nano scale of the cement hydration process, which leads to a nano-optimization of cement-based systems. Hard X-ray microtomography images on ice inside cement paste and cracking caused by the alkali-silica reaction (ASR) enables three-dimensional structural identification. The potential of neutron diffraction to determine reactive aggregates by measuring their residual strains and preferred orientation is studied. Results of experiments using these tools will be shown on this paper.

Characterizing the nano and micro structure of concrete to improve its durability

KAUST Repository

Monteiro, P.J.M.

2009-09-01

New and advanced methodologies have been developed to characterize the nano and microstructure of cement paste and concrete exposed to aggressive environments. High resolution full-field soft X-ray imaging in the water window is providing new insight on the nano scale of the cement hydration process, which leads to a nano-optimization of cement-based systems. Hard X-ray microtomography images of ice inside cement paste and cracking caused by the alkali-silica reaction (ASR) enables three-dimensional structural identification. The potential of neutron diffraction to determine reactive aggregates by measuring their residual strains and preferred orientation is studied. Results of experiments using these tools are shown on this paper. © 2009 Elsevier Ltd. All rights reserved.

Characterizing the nano and micro structure of concrete to improve its durability

KAUST Repository

Monteiro, P.J.M.; Kirchheim, A.P.; Chae, S.; Fischer, P.; MacDowell, A.A.; Schaible, E.; Wenk, H.R.

2009-01-01

New and advanced methodologies have been developed to characterize the nano and microstructure of cement paste and concrete exposed to aggressive environments. High resolution full-field soft X-ray imaging in the water window is providing new insight on the nano scale of the cement hydration process, which leads to a nano-optimization of cement-based systems. Hard X-ray microtomography images of ice inside cement paste and cracking caused by the alkali-silica reaction (ASR) enables three-dimensional structural identification. The potential of neutron diffraction to determine reactive aggregates by measuring their residual strains and preferred orientation is studied. Results of experiments using these tools are shown on this paper. © 2009 Elsevier Ltd. All rights reserved.

Design of a high speed, high resolution thermometry system for 1.5 GHz superconducting radio frequency cavities

Science.gov (United States)

Knobloch, Jens; Muller, Henry; Padamsee, Hasan

1994-11-01

Presented in this paper are the description and the test results of a new stationary thermometry system used to map the temperature of the outer surface of 1.5 GHz superconducting single-cell cavities during operation at 1.6 K. The system comprises 764 removable carbon thermometers whose signals are multiplexed and scanned by a Macintosh computer. A complete temperature map can be obtained in as little as 0.1 s at a temperature resolution of about 0.2 mK. Alternatively, it has been demonstrated that if the acquisition time is increased to several seconds, then a temperature resolution on the order of 30 μK is possible. To our knowledge, these are the fastest acquisition times so far achieved with L-band cavities at these resolutions.

Micro-CT and nano-CT analysis of filling quality of three different endodontic sealers.

Science.gov (United States)

Huang, Yan; Celikten, Berkan; de Faria Vasconcelos, Karla; Ferreira Pinheiro Nicolielo, Laura; Lippiatt, Nicholas; Buyuksungur, Arda; Jacobs, Reinhilde; Orhan, Kaan

2017-12-01

To investigate voids in different root canal sealers using micro-CT and nano-CT, and to explore the feasibility of using nano-CT for quantitative analysis of sealer filling quality. 30 extracted mandibular central incisors were randomly assigned into three groups according to the applied root canal sealers (Total BC Sealer, Sure Seal Root, AH Plus) by the single cone technique. Subsequently, micro-CT and nano-CT were performed to analyse the incidence rate of voids, void fraction, void volume and their distribution in each sample. Micro-CT evaluation showed no significant difference among sealers for the incidence rate of voids or void fraction in the whole filling materials (p > 0.05), whereas a significant difference was found between AH Plus and the other two sealers using nano-CT (p nano-CT results displayed higher void volume in AH Plus among all the sealers and regions (p nano-CT analysis, when round root canals were treated by the single cone technique. The disparate results suggest that the higher resolution of nano-CT have a greater ability of distinguishing internal porosity, and therefore suggesting the potential use of nano-CT in quantitative analysis of filling quality of sealers.

Microstructure characterization and magnetic properties of nano structured materials

Energy Technology Data Exchange (ETDEWEB)

Sun, X.C

2000-07-01

The present thesis deals with the unique microstructural properties and their novel magnetic properties of core-shell Ni-Ce nano composite particles, carbon encapsulated Fe, Co, and Ni nanoparticles and the nano crystallization behavior of typical ferromagnetic Fe{sub 78}Si{sub 9}B{sub 13} ribbons. These properties have intensively been investigated by high resolution transmission electron microscopy (HREM), X-ray diffraction (XRD), scanning electron microscopy (Sem), X-ray energy dispersive spectroscopy [eds.]; selected area electron diffraction pattern (SAED), Ft-IR, differential scanning calorimeter (DSC). In addition, magnetic moments measurements at different temperatures and applied fields have been performed by transmission Moessbauer spectroscopy, superconducting quantum interference device magnetometer (SQUID), and vibrating sample magnetometer (VSM). The present studies may provide the insights for the better understanding of the correlation between the unique microstructure and novel magnetic properties for several magnetic nano structured materials. (Author)

Comparative Study on Cushion Performance Between 3D Printed Kelvin Structure and 3D Printed Lattice Structure

Science.gov (United States)

Priyadarshini, Lakshmi

Frequently transported packaging goods are more prone to damage due to impact, jolting or vibration in transit. Fragile goods, for example, glass, ceramics, porcelain are susceptible to mechanical stresses. Hence ancillary materials like cushions play an important role when utilized within package. In this work, an analytical model of a 3D cellular structure is established based on Kelvin model and lattice structure. The research will provide a comparative study between the 3D printed Kelvin unit structure and 3D printed lattice structure. The comparative investigation is based on parameters defining cushion performance such as cushion creep, indentation, and cushion curve analysis. The applications of 3D printing is in rapid prototyping where the study will provide information of which model delivers better form of energy absorption. 3D printed foam will be shown as a cost-effective approach as prototype. The research also investigates about the selection of material for 3D printing process. As cushion development demands flexible material, three-dimensional printing with material having elastomeric properties is required. Further, the concept of cushion design is based on Kelvin model structure and lattice structure. The analytical solution provides the cushion curve analysis with respect to the results observed when load is applied over the cushion. The results are reported on basis of attenuation and amplification curves.

Collision-Induced Infrared Absorption by Hydrogen-Helium gas mixtures at Thousands of Kelvin

Science.gov (United States)

Abel, Martin; Frommhold, Lothar; Li, Xiaoping; Hunt, Katharine L. C.

2010-10-01

The interaction-induced absorption by collisional pairs of H2 molecules is an important opacity source in the atmospheres of the outer planets and cool stars ^[1]. The emission spectra of cool white dwarf stars differ significantly in the infrared from the expected blackbody spectra of their cores, which is largely due to absorption by collisional H2--H2, H2--He, and H2--H complexes in the stellar atmospheres. Using quantum-chemical methods we compute the atmospheric absorption from hundreds to thousands of kelvin ^[2]. Laboratory measurements of interaction-induced absorption spectra by H2 pairs exist only at room temperature and below. We show that our results reproduce these measurements closely ^[2], so that our computational data permit reliable modeling of stellar atmosphere opacities even for the higher temperatures ^[2]. [1] L. Frommhold, Collision-Induced Absorption in Gases, Cambridge University Press, Cambridge, New York, 1993 and 2006 [2] Xiaoping Li, Katharine L. C. Hunt, Fei Wang, Martin Abel, and Lothar Frommhold, ``Collision-Induced Infrared Absorption by Molecular Hydrogen Pairs at Thousands of Kelvin'', International Journal of Spectroscopy, vol. 2010, Article ID 371201, 11 pages, 2010. doi: 10.1155/2010/371201

Wave resistance calculation method combining Green functions based on Rankine and Kelvin source

Directory of Open Access Journals (Sweden)

LI Jingyu

2017-12-01

Full Text Available [Ojectives] At present, the Boundary Element Method(BEM of wave-making resistance mostly uses a model in which the velocity distribution near the hull is solved first, and the pressure integral is then calculated using the Bernoulli equation. However,the process of this model of wave-making resistance is complex and has low accuracy.[Methods] To address this problem, the present paper deduces a compound method for the quick calculation of ship wave resistance using the Rankine source Green function to solve the hull surface's source density, and combining the Lagally theorem concerning source point force calculation based on the Kelvin source Green function so as to solve the wave resistance. A case for the Wigley model is given.[Results] The results show that in contrast to the thin ship method of the linear wave resistance theorem, this method has higher precision, and in contrast to the method which completely uses the Kelvin source Green function, this method has better computational efficiency.[Conclusions] In general, the algorithm in this paper provides a compromise between precision and efficiency in wave-making resistance calculation.

Parent-Child Agreement Using the Spence Children’s Anxiety Scale and a Thermometer in Children with Autism Spectrum Disorder

Directory of Open Access Journals (Sweden)

T. May

2015-01-01

Full Text Available Children with Autism Spectrum Disorder (ASD experience high anxiety which often prompts clinical referral and requires intervention. This study aimed to compare parent and child reports on the Spence Children’s Anxiety Scale (SCAS and a child-reported “worry thermometer” in 88 children aged 8–13 years, 44 with ASD and 44 age, gender, and perceptual IQ matched typically developing children. There were no gender differences in child report on the SCAS and worry thermometers. Results indicated generally good correlations between parent and child self-reported SCAS symptoms for typically developing children but poor agreement in parent-child ASD dyads. The worry thermometer child-report did not reflect child or parent reports on the SCAS. Findings suggest 8–13-year-old children with ASD may have difficulties accurately reporting their anxiety levels. The clinical implications were discussed.

Chirality in MoS2 nano tubes studied by molecular dynamics simulation and images of high resolution microscopy

International Nuclear Information System (INIS)

Perez A, M.

2003-01-01

The nano tubes is a new material intensely studied from 1991 due to their characteristics that are the result of their nano metric size and of the associated quantum effects. Great part of these investigations have been focused to the characterization, modelling and computerized simulation, in order to studying its properties and possible behavior without necessity of the real manipulation of the material. The obtention of the structural properties in the different forms of particles of nano metric dimensions observed in the Transmission Electron Microscope is of great aid to study them mesoscopic characteristic of the material. (Author)

Quantitative dopant profiling in semiconductors. A new approach to Kelvin probe force microscopy

Energy Technology Data Exchange (ETDEWEB)

Baumgart, Christine

2012-07-01

Failure analysis and optimization of semiconducting devices request knowledge of their electrical properties. To meet the demands of today's semiconductor industry, an electrical nanometrology technique is required which provides quantitative information about the doping profile and which enables scans with a lateral resolution in the sub-10 nm range. In the presented work it is shown that Kelvin probe force microscopy (KPFM) is a very promising electrical nanometrology technique to face this challenge. The technical and physical aspects of KPFM measurements on semiconductors required for the correct interpretation of the detected KPFM bias are discussed. A new KPFM model is developed which enables the quantitative correlation between the probed KPFM bias and the dopant concentration in the investigated semiconducting sample. Quantitative dopant profiling by means of the new KPFM model is demonstrated by the example of differently structured, n- and p-type doped silicon. Additionally, the transport of charge carriers during KPFM measurements, in particular in the presence of intrinsic electric fields due to vertical and horizontal pn junctions as well as due to surface space charge regions, is discussed. Detailed investigations show that transport of charge carriers in the semiconducting sample is a crucial aspect and has to be taken into account when aiming for a quantitative evaluation of the probed KPFM bias.

Evidence of Boundary Reflection of Kelvin and First-Mode Rossby Waves from Topex/Poseidon Sea Level Data

Science.gov (United States)

Boulanger, Jean-Philippe; Fu, Lee-Lueng

1996-01-01

The TOPEX/POSEIDON sea level data lead to new opportunities to investigate some theoretical mechanisms suggested to be involved in the El Nino-Southern Oscillation phenomenon in the tropical Pacific ocean. In particular, we are interested in studying the western boundary reflection, a process crucial for the delayed action oscillator theory, by using the TOPEX/POSEIDON data from November 1992 to May 1995. We first projected the sea level data onto Kelvin and first-mode Ross waves. Then we estimated the contribution of wind forcing to these waves by using a single baroclinic mode simple wave model forced by the ERS-1 wind data. Wave propagation was clearly observed with amplitudes well explained by the wind forcing in the ocean interior. Evidence of wave reflection was detected at both the western and eastern boundaries of the tropical Pacific ocean. At the eastern boundary, Kelvin waves were seen to reflect as first-mode Rossby waves during the entire period. The reflection efficiency (in terms of wave amplitude) of the South American coasts was estimated to be 80% of that of an infinite meridional wall. At the western boundary, reflection was observed in April-August 1993, in January-June 1994, and, later, in December 1994 to February 1995. Although the general roles of these reflection events in the variability observed in the equatorial Pacific ocean are not clear, the data suggest that the reflections in January-June 1994 have played a role in the onset of the warm conditions observed in late 1994 to early 1995. Indeed, during the January-June 1994 period, as strong downwelling first-mode Rossby waves reflected into downwelling Kelvin waves, easterly wind and cold sea surface temperature anomalies located near the date line weakened and eventually reversed in June-July 1994. The presence of the warm anomalies near the date line then favored convection and westerly wind anomalies that triggered strong downwelling Kelvin waves propagating throughout the basin

Super-resolution optical microscopy for studying membrane structure and dynamics.

Science.gov (United States)

Sezgin, Erdinc

2017-07-12

Investigation of cell membrane structure and dynamics requires high spatial and temporal resolution. The spatial resolution of conventional light microscopy is limited due to the diffraction of light. However, recent developments in microscopy enabled us to access the nano-scale regime spatially, thus to elucidate the nanoscopic structures in the cellular membranes. In this review, we will explain the resolution limit, address the working principles of the most commonly used super-resolution microscopy techniques and summarise their recent applications in the biomembrane field.

Fabrication of micro- and nano-structured materials using mask-less processes

International Nuclear Information System (INIS)

Roy, Sudipta

2007-01-01

methodologies adopted for nano-fabrication have analogies with the micrometre scale patterning methods. Currently, the resolution of mask-less techniques is lower than that of lithographic methods using a physical mask. However, in future, hybridisation or combination of the mask-less methods could lead to high resolution and higher precision micro- and nano-scale patterning methods. (topical review)

Assessing the Nano-Dynamics of the Cell Surface

Energy Technology Data Exchange (ETDEWEB)

Bae, Chil Man [Dept. of Physiology and Biophysics, State University of New York, Buffalo (United States); Park, Ik Keun [Mechanical Engineering, Seoul National University of Technology, Seoul (Korea, Republic of); Bulter, Peter J. [Dept. of Bioengineering, The Pennsylvania State University, University Park (United States)

2012-06-15

It is important to know the mechanism of cell membrane fluctuation because it can be readout for the nanomechanical interaction between cytoskeleton and plasma membrane. Traditional techniques, however, have drawbacks such as probe contact with the cell surface, complicate analysis, and limit spatial and temporal resolution. In this study, we developed a new system for non-contact measurement of nano-scale localized-cell surface dynamics using modified-scanning ion-conductance microscopy. With 2 nm resolution, we determined that endothelial cells have local membrane fluctuations of -20 nm, actin depolymerization causes increase in fluctuation amplitude, and ATP depletion abolishes all membrane fluctuations.

Nano- and micro-electromechanical systems fundamentals of nano- and microengineering

CERN Document Server

Lyshevski, Sergey Edward

2005-01-01

NANOTECHNOLOGY AND MICROTECHNOLOGY (NANO- AND MICRO- SCIENCE, ENGINEERING AND TECHNOLOGY), AND BEYOND Introduction and Overview: From Micro- to Nano- and Beyond to Stringo-Scale Introductory Definitions to the Subjects Current Developments and Needs for Coherent Revolutionary Developments Societal Challenges and Implications NANO- AND MICROSCALE SYSTEMS, DEVICES, AND STRUCTURES Sizing Features: From Micro- to Nano-, and from Nano- to Stringo-Scale MEMS and NEMS Definitions Introduction to Taxonomy of Nano- and Microsystem Synthesis and Design Introduction to Design and Optimization of Nano- and Microsystems in the Behavioral Domain NANO- AND MICROSYSTEMS: CLASSIFICATION AND CONSIDERATION Biomimetics, Biological Analogies,and Design of NEMS and MEMS Micro- and Nanoelectromechanical Systems: Scaling Laws and Mathematical Modeling MEMS Examples and MEMS Architectures Introduction to Microfabrication and Micromachining FUNDAMENTALS OF MICROFABRICATION AND MEMS FABRICATION TECHNOLOGIES Introducti...

Alternative chemical-based synthesis routes and characterization of nano-scale particles

International Nuclear Information System (INIS)

Brocchi, E.A.; Motta, M.S.; Solorzano, I.G.; Jena, P.K.; Moura, F.J.

2004-01-01

Different nano-scale particles have been synthesized by alternative routes: nitrates dehydratation and oxide, or co-formed oxides, reduction by hydrogen. Chemical-based synthesis routes are described and thermodynamics studies and kinetics data are presented to support the feasibility for obtaining single-phase oxides and co-formed two-phase oxides. In addition, the reduction reaction has been applied to successfully produce metal/ceramic nanocomposites. Structural characterization has been carried out by means of X-ray diffraction and, more extensively, transmission electron microscopy operating in conventional diffraction contrast mode (CTEM) and high-resolution mode (HRTEM). Nano-scale size distribution of oxide particles is well demonstrated together with their defect-free structure in the lower range, around 20 nm, size. Structural features related to the synthesized nano-composites are also presented

Nano dentistry

International Nuclear Information System (INIS)

Oh, S.; Park, Y.B.; Kim, S.; Jin, S.

2014-01-01

Nano technology in dentistry has drawn many scientists’ and clinicians’ attention to significant advances in the diagnosis, treatment, and prevention of oral disease. Also, nano materials in dentistry have been studied to overcome the physical and chemical characteristics of conventional dental materials. These interesting facts are the motivation of this special issue. The presented issue provides a variety of topics in the field of dentistry such as novel nano filled composite resin, the cytotoxicity of nanoparticles deposited on orthodontic bands, the osseointegration of 3D nano scaffold, and nano surface treated implant.

Sub-10-nm suspended nano-web formation by direct laser writing

Science.gov (United States)

Wang, Sihao; Yu, Ye; Liu, Hailong; Lim, Kevin T. P.; Madurai Srinivasan, Bharathi; Zhang, Yong Wei; Yang, Joel K. W.

2018-06-01

A diffraction-limited three-dimensional (3D) direct laser writing (DLW) system based on two-photon polymerization can routinely pattern structures at the 100 nm length scale. Several schemes have been developed to improve the patterning resolution of 3D DLW but often require customized resist formulations or multi-wavelength exposures. Here, we introduce a scheme to produce suspended nano-webs with feature sizes below 10 nm in IP-Dip resist using sub-threshold exposure conditions in a commercial DLW system. The narrowest suspended lines (nano-webs) measured 7 nm in width. Larger ∼20 nm nano-webs were patterned with ∼80% yield at increased laser powers. In addition, closely spaced nano-gaps with a center-to-center distance of 33 nm were produced by patterning vertically displaced suspended lines followed by metal deposition and liftoff. We provide hypotheses and present preliminary results for a mechanism involving the initiation of a percolative path and a strain-induced narrowing in the nano-web formation. Our approach allows selective features to be patterned with dimensions comparable to the sub-10 nm patterning capability of electron-beam lithography (EBL).

The Kelvin-Helmholtz instability on the magnetopause

International Nuclear Information System (INIS)

Kivelson, M.G.; California Univ., Los Angeles; Pu, Z.-Y.

1984-01-01

Conditions for the development of Kelvin-Helmholtz (K-H) waves on the magnetopause have been known for more than 15 years; more recently, spacecraft observations have stimulated further examination of the properties of K-H waves. For a magnetopause with no boundary layer, two different modes of surface waves have been identified and their properties have been investigated for various assumed orientations of magnetic field and flow velocity vectors. The power radiated into the magnetosphere from the velocity shear at the boundary has been estimated. Other calculations have focused on the consequences of finite thickness boundary layers, both uniform and non-uniform. The boundary layer is found to modify the wave modes present at the magnetopause and to yield a criterion for the wavelength of the fastest growing surface waves. The paper concludes by questioning the extent to which the inferences from boundary layer models are model dependent and identifies areas where further work is needed or anticipated. (author)

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

International Nuclear Information System (INIS)

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

2012-01-01

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

Application of Monte Carlo Method for Evaluation of Uncertainties of ITS-90 by Standard Platinum Resistance Thermometer

Science.gov (United States)

Palenčár, Rudolf; Sopkuliak, Peter; Palenčár, Jakub; Ďuriš, Stanislav; Suroviak, Emil; Halaj, Martin

2017-06-01

Evaluation of uncertainties of the temperature measurement by standard platinum resistance thermometer calibrated at the defining fixed points according to ITS-90 is a problem that can be solved in different ways. The paper presents a procedure based on the propagation of distributions using the Monte Carlo method. The procedure employs generation of pseudo-random numbers for the input variables of resistances at the defining fixed points, supposing the multivariate Gaussian distribution for input quantities. This allows taking into account the correlations among resistances at the defining fixed points. Assumption of Gaussian probability density function is acceptable, with respect to the several sources of uncertainties of resistances. In the case of uncorrelated resistances at the defining fixed points, the method is applicable to any probability density function. Validation of the law of propagation of uncertainty using the Monte Carlo method is presented on the example of specific data for 25 Ω standard platinum resistance thermometer in the temperature range from 0 to 660 °C. Using this example, we demonstrate suitability of the method by validation of its results.

Role of interannual Kelvin wave propagations in the equatorial Atlantic on the Angola Benguela Current system

Science.gov (United States)

Imbol Koungue, Rodrigue Anicet; Illig, Serena; Rouault, Mathieu

2017-06-01

The link between equatorial Atlantic Ocean variability and the coastal region of Angola-Namibia is investigated at interannual time scales from 1998 to 2012. An index of equatorial Kelvin wave activity is defined based on Prediction and Research Moored Array in the Tropical Atlantic (PIRATA). Along the equator, results show a significant correlation between interannual PIRATA monthly dynamic height anomalies, altimetric monthly Sea Surface Height Anomalies (SSHA), and SSHA calculated with an Ocean Linear Model. This allows us to interpret PIRATA records in terms of equatorial Kelvin waves. Estimated phase speed of eastward propagations from PIRATA equatorial mooring remains in agreement with the linear theory, emphasizing the dominance of the second baroclinic mode. Systematic analysis of all strong interannual equatorial SSHA shows that they precede by 1-2 months extreme interannual Sea Surface Temperature Anomalies along the African coast, which confirms the hypothesis that major warm and cold events in the Angola-Benguela current system are remotely forced by ocean atmosphere interactions in the equatorial Atlantic. Equatorial wave dynamics is at the origin of their developments. Wind anomalies in the Western Equatorial Atlantic force equatorial downwelling and upwelling Kelvin waves that propagate eastward along the equator and then poleward along the African coast triggering extreme warm and cold events, respectively. A proxy index based on linear ocean dynamics appears to be significantly more correlated with coastal variability than an index based on wind variability. Results show a seasonal phasing, with significantly higher correlations between our equatorial index and coastal SSTA in October-April season.

Hollow Nanospheres Array Fabrication via Nano-Conglutination Technology.

Science.gov (United States)

Zhang, Man; Deng, Qiling; Xia, Liangping; Shi, Lifang; Cao, Axiu; Pang, Hui; Hu, Song

2015-09-01

Hollow nanospheres array is a special nanostructure with great applications in photonics, electronics and biochemistry. The nanofabrication technique with high resolution is crucial to nanosciences and nano-technology. This paper presents a novel nonconventional nano-conglutination technology combining polystyrenes spheres (PSs) self-assembly, conglutination and a lift-off process to fabricate the hollow nanospheres array with nanoholes. A self-assembly monolayer of PSs was stuck off from the quartz wafer by the thiol-ene adhesive material, and then the PSs was removed via a lift-off process and the hollow nanospheres embedded into the thiol-ene substrate was obtained. Thiolene polymer is a UV-curable material via "click chemistry" reaction at ambient conditions without the oxygen inhibition, which has excellent chemical and physical properties to be attractive as the adhesive material in nano-conglutination technology. Using the technique, a hollow nanospheres array with the nanoholes at the diameter of 200 nm embedded into the rigid thiol-ene substrate was fabricated, which has great potential to serve as a reaction container, catalyst and surface enhanced Raman scattering substrate.

The world of Nano

International Nuclear Information System (INIS)

Noh, Seung Jeong; Hyun, Jun Won; An, Yong Hyeon; Lee, Sung Uk; Jee, Hye Gu; Kim, Young Seon

2006-07-01

The contents of this book are the beginning of nano technology, definition of nano, commercialization of nano technology, prospect of nano technology, survive with nano t-, development strategy of n-t in the U.S, and Japan, Korea, and other countries, comparison of development strategy of n-t among each country, various measurement technology for practical n-t, scanning tunneling microscopy, nano device, carbon nano tube, nano belt and nano wire, application of sensor in daily life, energy, post-Genome period and using as medicine with nano bio technology.

Nano-Scale Positioning Design with Piezoelectric Materials

Directory of Open Access Journals (Sweden)

Yung Yue Chen

2017-12-01

Full Text Available Piezoelectric materials naturally possess high potential to deliver nano-scale positioning resolution; hence, they are adopted in a variety of engineering applications widely. Unfortunately, unacceptable positioning errors always appear because of the natural hysteresis effect of the piezoelectric materials. This natural property must be mitigated in practical applications. For solving this drawback, a nonlinear positioning design is proposed in this article. This nonlinear positioning design of piezoelectric materials is realized by the following four steps: 1. The famous Bouc–Wen model is utilized to present the input and output behaviors of piezoelectric materials; 2. System parameters of the Bouc–Wen model that describe the characteristics of piezoelectric materials are simultaneously identified with the particle swam optimization method; 3. Stability verification for the identified Bouc–Wen model; 4. A nonlinear feedback linearization control design is derived for the nano-scale positioning design of the piezoelectric material, mathematically. One important contribution of this investigation is that the positioning error between the output displacement of the controlled piezoelectric materials and the desired trajectory in nano-scale level can be proven to converge to zero asymptotically, under the effect of the hysteresis.

Time-Efficient High-Resolution Large-Area Nano-Patterning of Silicon Dioxide

DEFF Research Database (Denmark)

Lin, Li; Ou, Yiyu; Aagesen, Martin

2017-01-01

A nano-patterning approach on silicon dioxide (SiO2) material, which could be used for the selective growth of III-V nanowires in photovoltaic applications, is demonstrated. In this process, a silicon (Si) stamp with nanopillar structures was first fabricated using electron-beam lithography (EBL....... In addition, high time efficiency can be realized by one-spot electron-beam exposure in the EBL process combined with NIL for mass production. Furthermore, the one-spot exposure enables the scalability of the nanostructures for different application requirements by tuning only the exposure dose. The size...

Surface enhanced thermo lithography

KAUST Repository

Coluccio, Maria Laura

2017-01-13

We used electroless deposition to fabricate clusters of silver nanoparticles (NPs) on a silicon substrate. These clusters are plasmonics devices that induce giant electromagnetic (EM) field increments. When those EM field are absorbed by the metal NPs clusters generate, in turn, severe temperature increases. Here, we used the laser radiation of a conventional Raman set-up to transfer geometrical patterns from a template of metal NPs clusters into a layer of thermo sensitive Polyphthalaldehyde (PPA) polymer. Temperature profile on the devices depends on specific arrangements of silver nanoparticles. In plane temperature variations may be controlled with (i) high nano-meter spatial precision and (ii) single Kelvin temperature resolution on varying the shape, size and spacing of metal nanostructures. This scheme can be used to generate strongly localized heat amplifications for applications in nanotechnology, surface enhanced thermo-lithography (SETL), biology and medicine (for space resolved cell ablation and treatment), nano-chemistry.

Surface enhanced thermo lithography

KAUST Repository

Coluccio, Maria Laura; Alabastri, Alessandro; Bonanni, Simon; Majewska, Roksana; Dattoli, Elisabetta; Barberio, Marianna; Candeloro, Patrizio; Perozziello, Gerardo; Mollace, Vincenzo; Di Fabrizio, Enzo M.; Gentile, Francesco

2017-01-01

We used electroless deposition to fabricate clusters of silver nanoparticles (NPs) on a silicon substrate. These clusters are plasmonics devices that induce giant electromagnetic (EM) field increments. When those EM field are absorbed by the metal NPs clusters generate, in turn, severe temperature increases. Here, we used the laser radiation of a conventional Raman set-up to transfer geometrical patterns from a template of metal NPs clusters into a layer of thermo sensitive Polyphthalaldehyde (PPA) polymer. Temperature profile on the devices depends on specific arrangements of silver nanoparticles. In plane temperature variations may be controlled with (i) high nano-meter spatial precision and (ii) single Kelvin temperature resolution on varying the shape, size and spacing of metal nanostructures. This scheme can be used to generate strongly localized heat amplifications for applications in nanotechnology, surface enhanced thermo-lithography (SETL), biology and medicine (for space resolved cell ablation and treatment), nano-chemistry.

High-Resolution NDVI from Planet's Constellation of Earth Observing Nano-Satellites: A New Data Source for Precision Agriculture

KAUST Repository

Houborg, Rasmus; McCabe, Matthew

2016-01-01

Planet Labs ("Planet") operate the largest fleet of active nano-satellites in orbit, offering an unprecedented monitoring capacity of daily and global RGB image capture at 3-5 m resolution. However, limitations in spectral resolution and lack of accurate radiometric sensor calibration impact the utility of this rich information source. In this study, Planet's RGB imagery was translated into a Normalized Difference Vegetation Index (NDVI): a common metric for vegetation growth and condition. Our framework employs a data mining approach to build a set of rule-based regression models that relate RGB data to atmospherically corrected Landsat-8 NDVI. The approach was evaluated over a desert agricultural landscape in Saudi Arabia where the use of near-coincident (within five days) Planet and Landsat-8 acquisitions in the training of the regression models resulted in NDVI predictabilities with an r2 of approximately 0.97 and a Mean Absolute Deviation (MAD) on the order of 0.014 (~9%). The MAD increased to 0.021 (~14%) when the Landsat NDVI training image was further away (i.e., 11-16 days) from the corrected Planet image. In these cases, the use of MODIS observations to inform on the change in NDVI occurring between overpasses was shown to significantly improve prediction accuracies. MAD levels ranged from 0.002 to 0.011 (3.9% to 9.1%) for the best performing 80% of the data. The technique is generic and extendable to any region of interest, increasing the utility of Planet's dense time-series of RGB imagery.

High-Resolution NDVI from Planet's Constellation of Earth Observing Nano-Satellites: A New Data Source for Precision Agriculture

KAUST Repository

Houborg, Rasmus

2016-09-19

Planet Labs ("Planet") operate the largest fleet of active nano-satellites in orbit, offering an unprecedented monitoring capacity of daily and global RGB image capture at 3-5 m resolution. However, limitations in spectral resolution and lack of accurate radiometric sensor calibration impact the utility of this rich information source. In this study, Planet\\'s RGB imagery was translated into a Normalized Difference Vegetation Index (NDVI): a common metric for vegetation growth and condition. Our framework employs a data mining approach to build a set of rule-based regression models that relate RGB data to atmospherically corrected Landsat-8 NDVI. The approach was evaluated over a desert agricultural landscape in Saudi Arabia where the use of near-coincident (within five days) Planet and Landsat-8 acquisitions in the training of the regression models resulted in NDVI predictabilities with an r2 of approximately 0.97 and a Mean Absolute Deviation (MAD) on the order of 0.014 (~9%). The MAD increased to 0.021 (~14%) when the Landsat NDVI training image was further away (i.e., 11-16 days) from the corrected Planet image. In these cases, the use of MODIS observations to inform on the change in NDVI occurring between overpasses was shown to significantly improve prediction accuracies. MAD levels ranged from 0.002 to 0.011 (3.9% to 9.1%) for the best performing 80% of the data. The technique is generic and extendable to any region of interest, increasing the utility of Planet\\'s dense time-series of RGB imagery.

Cross-Bridge Kelvin resistor structures for reliable measurement of low contact resistances and contact interface characterization

NARCIS (Netherlands)

Stavitski, N.; Klootwijk, J.H.; van Zeijl, H.W.; Kovalgin, Alexeij Y.; Wolters, Robertus A.M.

2009-01-01

The parasitic factors that strongly influence the measurement accuracy of Cross-Bridge Kelvin Resistor (CBKR) structures for low specific contact resistances (�?�c) have been extensively discussed during last few decades and the minimum of the �?�c value, which could be accurately extracted, was

Kelvin-Helmholtz instability for a bounded plasma flow in a longitudinal magnetic field

International Nuclear Information System (INIS)

Burinskaya, T. M.; Shevelev, M. M.; Rauch, J.-L.

2011-01-01

Kelvin-Helmholtz MHD instability in a plane three-layer plasma is investigated. A general dispersion relation for the case of arbitrarily orientated magnetic fields and flow velocities in the layers is derived, and its solutions for a bounded plasma flow in a longitudinal magnetic field are studied numerically. Analysis of Kelvin-Helmholtz instability for different ion acoustic velocities shows that perturbations with wavelengths on the order of or longer than the flow thickness can grow in an arbitrary direction even at a zero temperature. Oscillations excited at small angles with respect to the magnetic field exist in a limited range of wavenumbers even without allowance for the finite width of the transition region between the flow and the ambient plasma. It is shown that, in a low-temperature plasma, solutions resulting in kink-like deformations of the plasma flow grow at a higher rate than those resulting in quasi-symmetric (sausage-like) deformations. The transverse structure of oscillatory-damped eigenmodes in a low-temperature plasma is analyzed. The results obtained are used to explain mechanisms for the excitation of ultra-low-frequency long-wavelength oscillations propagating along the magnetic field in the plasma sheet boundary layer of the Earth’s magnetotail penetrated by fast plasma flows.

Germanium thermometers in the temperature range .1000K to 4.20K

International Nuclear Information System (INIS)

Hsieh, S.Y.; Sanchez, D.H.

1974-01-01

The sensitivity characteristics of two germanium thermometers that proved to be convenient sensors in the temperature range from .100 0 K to 4.2 0 K, are described. Their resistances change from about 8 x 10 5 ohms at .100 0 K to about 100 ohms at 4.2 0 K. The calibration curves were fitted to natural spline functions of order 3 in the whole range of temperatures. These functions give less than half millidegree standard dispersion against 15 millidegree standard dispersion when usual polynomial interpolations are used. It is discussed what spline functions are, and compare the goodness of spline interpolation with polynomial methods [pt

Evolution of the magnesium incorporated amorphous calcium phosphate to nano-crystallized hydroxyapatite in alkaline solution

Science.gov (United States)

Zhang, Xiao-Juan; Lin, Dong-Yang; Yan, Xiao-Hui; Wang, Xiao-Xiang

2011-12-01

A homogeneous amorphous calcium phosphate (ACP) coating containing magnesium was achieved on titanium substrates by electrochemical deposition (ECD). Its amorphous structure is confirmed by transmission electron microscope (TEM) together with grazing reflection absorption infrared spectroscopy (IR) spectrometer. In the images of high-resolution transmission electron microscope (HRTEM), the ACP spheres are assembled by nano-particles with the diameter of 5-10 nm. In the alkaline environment, nucleation of hydroxyapatite (HAP) occurs on the surfaces of ACP spheres. By consuming the Ca and PO 4 ions inside the ACP spheres, the HAP nuclei grow outward. Confirmed by TEM, the ACP spheres converse to hollow HAP spheres composed of HAP nano-needles. The coating is finally constructed by the HAP nano-needles, which are themselves aggregated by numerous nano-particles.

Elastic nano-structure of diamond-like carbon (DLC)

International Nuclear Information System (INIS)

Ogiso, Hisato; Yoshida, Mikiko; Nakano, Shizuka; Yasui, Haruyuki; Awazu, Kaoru

2006-01-01

This research discusses the elastic nano-structure of diamond-like carbon (DLC) films. Two DLC film samples deposited by plasma based ion implantation (PBII) were prepared. The plasma generated by microwave (MW) was applied to one sample and the plasma by radio frequency (RF) to the other sample. The samples were evaluated for the elastic property image with nanometer resolution using scanning probe microscopy (SPM). The film surface deposited by RF-PBII was very flat and homogeneous in elastic property. In contrast, the film surface by MW-PBII was more uneven than that by RF-PBII and both the locally hard and the locally soft regions were found at the film surface. The size of the structure in elastic property is several tens nanometer. We conclude that the film probably contains nano-scale diamond phase

Elastic nano-structure of diamond-like carbon (DLC)

Energy Technology Data Exchange (ETDEWEB)

Ogiso, Hisato [National Institute of Advanced Industrial Science and Technology (AIST), 1-2-1 Namiki, Tsukuba, Ibaraki 305-8564 (Japan); Yoshida, Mikiko [National Institute of Advanced Industrial Science and Technology (AIST), 1-2-1 Namiki, Tsukuba, Ibaraki 305-8564 (Japan); Nakano, Shizuka [National Institute of Advanced Industrial Science and Technology (AIST), 1-2-1 Namiki, Tsukuba, Ibaraki 305-8564 (Japan); Yasui, Haruyuki [Industrial Research Institute of Ishikawa (IRII), Ro-1, Tomizu-machi, Kanazawa, Ishikawa 920-0233 (Japan); Awazu, Kaoru [Industrial Research Institute of Ishikawa (IRII), Ro-1, Tomizu-machi, Kanazawa, Ishikawa 920-0233 (Japan)

2006-01-15

This research discusses the elastic nano-structure of diamond-like carbon (DLC) films. Two DLC film samples deposited by plasma based ion implantation (PBII) were prepared. The plasma generated by microwave (MW) was applied to one sample and the plasma by radio frequency (RF) to the other sample. The samples were evaluated for the elastic property image with nanometer resolution using scanning probe microscopy (SPM). The film surface deposited by RF-PBII was very flat and homogeneous in elastic property. In contrast, the film surface by MW-PBII was more uneven than that by RF-PBII and both the locally hard and the locally soft regions were found at the film surface. The size of the structure in elastic property is several tens nanometer. We conclude that the film probably contains nano-scale diamond phase.

Environmental risk assessment of engineered nano-SiO2 , nano iron oxides, nano-CeO2 , nano-Al2 O3 , and quantum dots.

Science.gov (United States)

Wang, Yan; Nowack, Bernd

2018-05-01

Many research studies have endeavored to investigate the ecotoxicological hazards of engineered nanomaterials (ENMs). However, little is known regarding the actual environmental risks of ENMs, combining both hazard and exposure data. The aim of the present study was to quantify the environmental risks for nano-Al 2 O 3 , nano-SiO 2 , nano iron oxides, nano-CeO 2 , and quantum dots by comparing the predicted environmental concentrations (PECs) with the predicted-no-effect concentrations (PNECs). The PEC values of these 5 ENMs in freshwaters in 2020 for northern Europe and southeastern Europe were taken from a published dynamic probabilistic material flow analysis model. The PNEC values were calculated using probabilistic species sensitivity distribution (SSD). The order of the PNEC values was quantum dots nano-CeO 2  nano iron oxides nano-Al 2 O 3  nano-SiO 2 . The risks posed by these 5 ENMs were demonstrated to be in the reverse order: nano-Al 2 O 3  > nano-SiO 2  > nano iron oxides > nano-CeO 2  > quantum dots. However, all risk characterization values are 4 to 8 orders of magnitude lower than 1, and no risk was therefore predicted for any of the investigated ENMs at the estimated release level in 2020. Compared to static models, the dynamic material flow model allowed us to use PEC values based on a more complex parameterization, considering a dynamic input over time and time-dependent release of ENMs. The probabilistic SSD approach makes it possible to include all available data to estimate hazards of ENMs by considering the whole range of variability between studies and material types. The risk-assessment approach is therefore able to handle the uncertainty and variability associated with the collected data. The results of the present study provide a scientific foundation for risk-based regulatory decisions of the investigated ENMs. Environ Toxicol Chem 2018;37:1387-1395. © 2018 SETAC. © 2018 SETAC.

Synthesis and characterization of a-site doped LaTiO3 nano perovskites

International Nuclear Information System (INIS)

Bradha, M.; Ashok, Anuradha

2013-01-01

Nano-sized lanthanum titanate perovskites (La (1-x) A x TiO 3 ) (A= Ba, Sr, Ca) were prepared by sol-gel method and calcined at 800℃. The synthesised perovskites were characterized by Thermogravimetry/ Differential thermal analysis (TGA/DTA), X-ray diffraction (XRD) and High Resolution Transmission Electron Microscopy (HRTEM) etc. LaTiO 3 is a perovskite having prominent interest for a variety of applications such as dielectric, insulators, charge-transport properties etc. It is a defect perovskite, with transport properties varying from insulating to metallic based on oxygen stoichiometry. In a quest to observe the effect of the nano size on its properties, lanthanum titanate (LaTiO 3 ) nano perovskites with different dopants on the A-site were prepared by using sol-gel method. In the present work we discuss the synthesis and structural analysis of (La 0.8 A 0.2 TiO 3 ). Phase purity and structural analysis of the calcined samples were performed by powder X-ray diffraction (XRD, with CuKα radiation). In addition to this, morphology and crystal structure was examined by Transmission Electron Microscopy (TEM) using a JEOL JEM 2100 HRTEM. HRTEM studies indicate that the nano perovskites are of size around 20 nm. Ring pattern in SAED also confirms that the perovskite is polycrystalline/nanocrystalline. More detailed study on high resolution images and crystal structure shed light on the reason for the properties exhibited by this perovskites

Chemical Functionalization, Self-Assembly, and Applications of Nano materials and Nano composites 2014

International Nuclear Information System (INIS)

Yan, X.; Jiao, T.; Balan, L.; Chen, X.; Hu, M.Z.; Liu, W.

2014-01-01

The growing interests in nano materials and nano composites call for the development of processing techniques to obtain multiple functionalization nano structures and achieve the tailoring of specific features of the nanometer size. Functional nano materials and nano composites will expand the applied range of the original material and at the same time promote the development of inter discipline. Thus, the chemical functionalization and bottom-up assemblies of nano materials and subsequent applications will accelerate the development of nano science and nano technology.

Quantitative analysis of supported membrane composition using the NanoSIMS

Energy Technology Data Exchange (ETDEWEB)

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

2009-06-02

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

Distinction between magnesium diboride and tetraboride by kelvin probe force microscopy

International Nuclear Information System (INIS)

Kim, Du-Na; Caron, Arnaud; Park, Hai Woong

2016-01-01

We analyze mixtures of magnesium diboride and tetraboride synthesized with magnesium powders of different shapes. To distinguish between magnesium diboride and tetraboride we use the contrast of kelvin probe force microscopy. The microstructural morphology strongly depends on the shape of the magnesium powders used in the reaction between magnesium and magnesium tetraboride to form magnesium diboride. With spherical magnesium powder an equiaxed microstructure of magnesium diboride is formed with residual magnesium tetraboride at the grain boundaries. With plate-like magnesium powders elongated magnesium diboride grains are formed. In this case, residual magnesium tetraboride is found to agglomerate.

Analysis of Kelvin Probe operational models with application to SR-POEM

International Nuclear Information System (INIS)

Popescu, Eugeniu M

2011-01-01

We present a study of several models on which Kelvin Probe (KP) instruments with flat and spherical tips rely for operation and for the determination of the contact potential difference (CPD). The study is part of the development of a high-performance KP instrument that will be used in investigations of the patch effect for the sounding rocket principle of equivalence measurement experiment. Using covariance analysis for each model we investigate its performance as imposed by the Cramer-Rao bounds and the biases introduced in the estimation of the CPD, as well as its applicability to instrument control. (papers)

Designing a TAC thermometer from a VHTR graphite structure

Energy Technology Data Exchange (ETDEWEB)

Smith, James A., E-mail: James.Smith@INL.gov; Kotter, Dale, E-mail: James.Smith@INL.gov [Fuel Performance and Design, Idaho National Laboratory, Idaho Falls, ID 83415 (United States); Garrett, Steven L.; Ali, Randall A. [Graduate Program in Acoustics, Penn State University, State College, PA (United States)

2015-03-31

The interior of a nuclear reactor presents a particularly harsh and challenging environment for both sensors and telemetry due to high temperatures and high fluxes of energetic and ionizing particles among the radioactive decay products. Very High Temperature Reactors are pushing the in core temperatures even higher. A unique sensing approach will be discussed to address the necessary high temperature measurements. Thermoacoustic thermometry exploits high temperatures and uses materials that are immune to the effects of ionizing radiation to create a temperature sensor that is self-powered and wireless. In addition, the form-factor for the Thermoacoustic Thermometer (TACT) can be designed to be integrated within common in-pile structures. There are no physical moving parts required for TACT and the sensor is self-powered, as it uses the nuclear fuel for its heat source. TACT data will be presented from a laboratory prototype mimicking the design necessary for a VHTR graphite structure.

Nano-scaled iron-carbon precipitates in HSLC and HSLA steels

Institute of Scientific and Technical Information of China (English)

2007-01-01

This paper studies the composition, quantity and particle size distribution of nano-scaled precipitates with size less than 20 nm in high strength low carbon (HSLC) steel and their effects on mechanical properties of HSLC steel by means of mass balance calculation of nano-scaled precipitates measured by chemical phase analysis plus SAXS method, high-resolution TEM analysis and thermodynamics calculation, as well as temper rapid cooling treatment of ZJ330. It is found that there existed a large quantity of nano-scaled iron-carbon precipitates with size less than 18 nm in low carbon steel produced by CSP and they are mainly Fe-O-C and Fe-Ti-O-C precipitates formed below temperature A1. These precipitates have ob- vious precipitation strengthening effect on HSLC steel and this may be regarded as one of the main reasons why HSLC steel has higher strength. There also existed a lot of iron-carbon precipitates with size less than 36 nm in HSLA steels.

Nano-scaled iron-carbon precipitates in HSLC and HSLA steels

Institute of Scientific and Technical Information of China (English)

FU Jie; WU HuaJie; LIU YangChun; KANG YongLin

2007-01-01

This paper studies the composition, quantity and particle size distribution of nano-scaled precipitates with size less than 20 nm in high strength Iow carbon (HSLC) steel and their effects on mechanical properties of HSLC steel by means of mass balance calculation of nano-scaled precipitates measured by chemical phase analysis plus SAXS method, high-resolution TEM analysis and thermodynamics calculation, as well as temper rapid cooling treatment of ZJ330. It is found that there existed a large quantity of nano-scaled iron-carbon precipitates with size less than 18 nm in Iow carbon steel produced by CSP and they are mainly Fe-O-C and Fe-Ti-O-C precipitates formed below temperature A1. These precipitates have obvious precipitation strengthening effect on HSLC steel and this may be regarded as one of the main reasons why HSLC steel has higher strength. There also existed a lot of iron-carbon precipitates with size less than 36 nm in HSLA steels.

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

Directory of Open Access Journals (Sweden)

Ammar Ben Brahim

2013-05-01

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

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

Science.gov (United States)

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

2013-01-01

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

Collision-Induced Infrared Absorption by Collisional Complexes in Dense Hydrogen-Helium Gas Mixtures at Thousands of Kelvin

Science.gov (United States)

Abel, Martin; Frommhold, Lothar; Li, Xiaoping; Hunt, Katharine L. C.

2011-06-01

The interaction-induced absorption by collisional pairs of H{_2} molecules is an important opacity source in the atmospheres of the outer planets and cool stars. The emission spectra of cool white dwarf stars differ significantly in the infrared from the expected blackbody spectra of their cores, which is largely due to absorption by collisional H{_2}-H{_2}, H{_2}-He, and H{_2}-H complexes in the stellar atmospheres. Using quantum-chemical methods we compute the atmospheric absorption from hundreds to thousands of kelvin. Laboratory measurements of interaction-induced absorption spectra by H{_2} pairs exist only at room temperature and below. We show that our results reproduce these measurements closely, so that our computational data permit reliable modeling of stellar atmosphere opacities even for the higher temperatures. L. Frommhold, Collision-Induced Absorption in Gases, Cambridge University Press, Cambridge, New York, 1993 and 2006 Xiaoping Li, Katharine L. C. Hunt, Fei Wang, Martin Abel, and Lothar Frommhold, "Collision-Induced Infrared Absorption by Molecular Hydrogen Pairs at Thousands of Kelvin", International Journal of Spectroscopy, vol. 2010, Article ID 371201, 11 pages, 2010. doi: 10.1155/2010/371201 M. Abel, L. Frommhold, X. Li, and K. L. C. Hunt, "Collision-induced absorption by H{_2} pairs: From hundreds to thousands of Kelvin," J. Phys. Chem. A, published online, DOI: 10.1021/jp109441f L. Frommhold, M. Abel, F. Wang, M. Gustafsson, X. Li, and K. L. C. Hunt, "Infrared atmospheric emission and absorption by simple molecular complexes, from first principles", Mol. Phys. 108, 2265, 2010

Observations of Confinement of a Paramagnetic Liquid in Model Propellant Tanks in Microgravity by the Kelvin Force

Science.gov (United States)

Kuhlman, John; Gray, Donald D.; Barnard, Austin; Hazelton, Jennifer; Lechliter, Matthew; Starn, Andrew; Battleson, Charles; Glaspell, Shannon; Kreitzer, Paul; Leichliter, Michelle

2002-11-01

The magnetic Kelvin force has been proposed as an artificial gravity to control the orientation of paramagnetic liquid propellants such as liquid oxygen in a microgravity environment. This paper reports experiments performed in the NASA "Weightless Wonder" KC-135 aircraft, through the Reduced Gravity Student Flight Opportunities Program. The aircraft flies through a series of parabolic arcs providing about 25 s of microgravity in each arc. The experiment was conceived, designed, constructed, and performed by the undergraduate student team and their two faculty advisors. Two types of tanks were tested: square-base prismatic tanks 5 cm x 5 cm x 8.6 cm and circular cylinders 5 cm in diameter and 8.6 cm tall. The paramagnetic liquid was a 3.3 molar solution of MnCl2 in water. Tests were performed with each type of tank filled to depths of 1 cm and 4 cm. Each test compared a pair of tanks that were identical except that the base of one was a pole face of a 0.6 Tesla permanent magnet. The Kelvin force attracts paramagnetic materials toward regions of higher magnetic field. It was hypothesized that the Kelvin force would hold the liquid in the bottom of the tanks during the periods of microgravity. The tanks were installed in a housing that could slide on rails transverse to the flight direction. By manually shoving the housing, an identical impulse could be provided to each tank at the beginning of each period of microgravity. The resulting fluid motions were videotaped for later analysis.

Micro/nano-computed tomography technology for quantitative dynamic, multi-scale imaging of morphogenesis.

Science.gov (United States)

Gregg, Chelsea L; Recknagel, Andrew K; Butcher, Jonathan T

2015-01-01

Tissue morphogenesis and embryonic development are dynamic events challenging to quantify, especially considering the intricate events that happen simultaneously in different locations and time. Micro- and more recently nano-computed tomography (micro/nanoCT) has been used for the past 15 years to characterize large 3D fields of tortuous geometries at high spatial resolution. We and others have advanced micro/nanoCT imaging strategies for quantifying tissue- and organ-level fate changes throughout morphogenesis. Exogenous soft tissue contrast media enables visualization of vascular lumens and tissues via extravasation. Furthermore, the emergence of antigen-specific tissue contrast enables direct quantitative visualization of protein and mRNA expression. Micro-CT X-ray doses appear to be non-embryotoxic, enabling longitudinal imaging studies in live embryos. In this chapter we present established soft tissue contrast protocols for obtaining high-quality micro/nanoCT images and the image processing techniques useful for quantifying anatomical and physiological information from the data sets.

Method to obtain carbon nano-onions by pyrolisys of propane

Science.gov (United States)

Garcia-Martin, Tomas; Rincon-Arevalo, Pedro; Campos-Martin, Gemma

2013-11-01

We present a new and simple method for carbon nano-onions (CNOs) production which is based on the pyrolysis of Propane. CNOs are originated in a laminar premixed Propane/Oxygen flame of approximately 1.8 of stoichiometric coefficient. The stream of gasses resulting from the combustion drives the carbon particles towards the aluminium surface on which nano-onions are deposited and collected. The structure and size of the deposited carbon onion on the metal wall are characterized by High Resolution Transmission Electron Microscopy technique (HRTEM). The experimental images show the presence of two different types of CNOs. The first particles have diameters in the range of 18-25 nm and the second ones around 10 nm.

Edge contact angle and modified Kelvin equation for condensation in open pores.

Science.gov (United States)

Malijevský, Alexandr; Parry, Andrew O; Pospíšil, Martin

2017-08-01

We consider capillary condensation transitions occurring in open slits of width L and finite height H immersed in a reservoir of vapor. In this case the pressure at which condensation occurs is closer to saturation compared to that occurring in an infinite slit (H=∞) due to the presence of two menisci that are pinned near the open ends. Using macroscopic arguments, we derive a modified Kelvin equation for the pressure p_{cc}(L;H) at which condensation occurs and show that the two menisci are characterized by an edge contact angle θ_{e} that is always larger than the equilibrium contact angle θ, only equal to it in the limit of macroscopic H. For walls that are completely wet (θ=0) the edge contact angle depends only on the aspect ratio of the capillary and is well described by θ_{e}≈sqrt[πL/2H] for large H. Similar results apply for condensation in cylindrical pores of finite length. We test these predictions against numerical results obtained using a microscopic density-functional model where the presence of an edge contact angle characterizing the shape of the menisci is clearly visible from the density profiles. Below the wetting temperature T_{w} we find very good agreement for slit pores of widths of just a few tens of molecular diameters, while above T_{w} the modified Kelvin equation only becomes accurate for much larger systems.

Edge contact angle and modified Kelvin equation for condensation in open pores

Science.gov (United States)

Malijevský, Alexandr; Parry, Andrew O.; Pospíšil, Martin

2017-08-01

We consider capillary condensation transitions occurring in open slits of width L and finite height H immersed in a reservoir of vapor. In this case the pressure at which condensation occurs is closer to saturation compared to that occurring in an infinite slit (H =∞ ) due to the presence of two menisci that are pinned near the open ends. Using macroscopic arguments, we derive a modified Kelvin equation for the pressure pc c(L ;H ) at which condensation occurs and show that the two menisci are characterized by an edge contact angle θe that is always larger than the equilibrium contact angle θ , only equal to it in the limit of macroscopic H . For walls that are completely wet (θ =0 ) the edge contact angle depends only on the aspect ratio of the capillary and is well described by θe≈√{π L /2 H } for large H . Similar results apply for condensation in cylindrical pores of finite length. We test these predictions against numerical results obtained using a microscopic density-functional model where the presence of an edge contact angle characterizing the shape of the menisci is clearly visible from the density profiles. Below the wetting temperature Tw we find very good agreement for slit pores of widths of just a few tens of molecular diameters, while above Tw the modified Kelvin equation only becomes accurate for much larger systems.

A comparison of absolute calibrations of a radiation thermometer based on a monochromator and a tunable source

Energy Technology Data Exchange (ETDEWEB)

Keawprasert, T. [National Institute of Metrology Thailand, Pathum thani (Thailand); Anhalt, K.; Taubert, D. R.; Sperling, A.; Schuster, M.; Nevas, S. [Physikalisch Technische Bundesanstalt, Braunschweig and Berlin (Germany)

2013-09-11

An LP3 radiation thermometer was absolutely calibrated at a newly developed monochromator-based set-up and the TUneable Lasers in Photometry (TULIP) facility of PTB in the wavelength range from 400 nm to 1100 nm. At both facilities, the spectral radiation of the respective sources irradiates an integrating sphere, thus generating uniform radiance across its precision aperture. The spectral irradiance of the integrating sphere is determined via an effective area of a precision aperture and a Si trap detector, traceable to the primary cryogenic radiometer of PTB. Due to the limited output power from the monochromator, the absolute calibration was performed with the measurement uncertainty of 0.17 % (k= 1), while the respective uncertainty at the TULIP facility is 0.14 %. Calibration results obtained by the two facilities were compared in terms of spectral radiance responsivity, effective wavelength and integral responsivity. It was found that the measurement results in integral responsivity at the both facilities are in agreement within the expanded uncertainty (k= 2). To verify the calibration accuracy, the absolutely calibrated radiation thermometer was used to measure the thermodynamic freezing temperatures of the PTB gold fixed-point blackbody.

A comparison of absolute calibrations of a radiation thermometer based on a monochromator and a tunable source

International Nuclear Information System (INIS)

Keawprasert, T.; Anhalt, K.; Taubert, D. R.; Sperling, A.; Schuster, M.; Nevas, S.

2013-01-01

An LP3 radiation thermometer was absolutely calibrated at a newly developed monochromator-based set-up and the TUneable Lasers in Photometry (TULIP) facility of PTB in the wavelength range from 400 nm to 1100 nm. At both facilities, the spectral radiation of the respective sources irradiates an integrating sphere, thus generating uniform radiance across its precision aperture. The spectral irradiance of the integrating sphere is determined via an effective area of a precision aperture and a Si trap detector, traceable to the primary cryogenic radiometer of PTB. Due to the limited output power from the monochromator, the absolute calibration was performed with the measurement uncertainty of 0.17 % (k= 1), while the respective uncertainty at the TULIP facility is 0.14 %. Calibration results obtained by the two facilities were compared in terms of spectral radiance responsivity, effective wavelength and integral responsivity. It was found that the measurement results in integral responsivity at the both facilities are in agreement within the expanded uncertainty (k= 2). To verify the calibration accuracy, the absolutely calibrated radiation thermometer was used to measure the thermodynamic freezing temperatures of the PTB gold fixed-point blackbody

Formation of Nano scale Bio imprints of Muscle Cells Using UV-Cured Spin-Coated Polymers

International Nuclear Information System (INIS)

Samsuri, F.; Alkaisi, M.M.; Mitchell, J.S.; Evans, J.J.

2009-01-01

We report a nano scale replication method suitable for biological specimens that has potential in single cell studies and in formation of 3D biocompatible scaffolds. Earlier studies using a heat-curable polydimethylsiloxane (PDMS) or a UV-curable elastomer introduced Bio imprint replication to facilitate cell imaging. However, the replicating conditions for thermal polymerization are known to cause cell dehydration during curing. In this study, a UV-cured methacrylate copolymer was developed for use in creating replicas of living cells and was tested on rat muscle cells. Bio imprints of muscle cells were formed by spin coating under UV irradiation. The polymer replicas were then separated from the muscle cells and were analyzed under an Atomic Force Microscope (AFM), in tapping mode, because it has low tip-sample forces and thus will not destroy the fine structures of the imprint. The new polymer is biocompatible with higher replication resolution and has a faster curing process than other types of silicon-based organic polymers such as PDMS. High resolution images of the muscle cell imprints showed the micro-and nano structures of the muscle cells, including cellular fibers and structures within the cell membranes. The AFM is able to image features at nano scale resolution with the potential for recognizing abnormalities on cell membranes at early stages of disease progression.

Phenylboronic acid functionalized reduced graphene oxide based fluorescence nano sensor for glucose sensing

Energy Technology Data Exchange (ETDEWEB)

Basiruddin, SK; Swain, Sarat K., E-mail: swainsk2@yahoo.co.in

2016-01-01

Reduced graphene has emerged as promising tools for detection based application of biomolecules as it has high surface area with strong fluorescence quenching property. We have used the concept of fluorescent quenching property of reduced graphene oxide to the fluorescent probes which are close vicinity of its surface. In present work, we have synthesized fluorescent based nano-sensor consist of phenylboronic acid functionalized reduced graphene oxide (rGO–PBA) and di-ol modified fluorescent probe for detection of biologically important glucose molecules. This fluorescent graphene based nano-probe has been characterized by high resolution transmission electron microscope (HRTEM), Atomic force microscope (AFM), UV–visible, Photo-luminescence (PL) and Fourier transformed infrared (FT-IR) spectroscopy. Finally, using this PBA functionalized reduced GO based nano-sensor, we were able to detect glucose molecule in the range of 2 mg/mL to 75 mg/mL in aqueous solution of pH 7.4. - Highlights: • Easy and simple synthesis of PBA functionalized reduced GO based nano probe. • PBA functionalized reduced GO graphene based nano-probes are characterized. • PBA functionalized reduced GO nano probe is used to detect glucose molecules. • It is very cost-effective and enzyme-free detection of glucose in solution.

Synthesis and structural characterization of coaxial nano tubes intercalated of molybdenum disulfide with carbon

International Nuclear Information System (INIS)

Reza San German, C.M.

2005-01-01

In this work the study of some fundamental aspects in the growth of unidimensional systems of coaxial nano tubes from the mold method is approached. This method is an inclusion technique of a precursor reagent into oxide nano porous alumina film (mold), and later applying some processes of synthesis it is gotten to obtain the wished material. The synthesized structures are identified later because they take place by means of the initial formation of nano tubes of MoS 2 , enclosing to carbon nano tubes by the same method, with propylene flow which generates a graphitization process that 'copy' the mold through as it flows. Binary phase MoS 2 + C nano tubes were synthesized by propylene pyrolysis inside MoS 2 nano tubes prepared by template assisted technique. The large coaxial nano tubes constituted of graphite sheets inserted between the MoS 2 layers forming the outer part, and coaxial multi wall carbon nano tubes (MWCNT) intercalated with MoS 2 inside. High resolution electron microscopy (HRTEM), electron energy loss spectroscopy (EELS), high angle annular dark field (HAADF), gatan image filter (GIF), nano beam electron diffraction patterns (NBEDP), along with molecular dynamics simulation and quantum mechanical calculations were used to characterize the samples. The one-dimensional structures exhibit diverse morphologies such as long straight and twisted nano tubes with several structural irregularities. The inter-planar spacing between MoS 2 layers was found to increase from 6.3 to 7.4 A due to intercalation with carbon. Simulated HREM images revealed the presence of these twisted nano structures, with mechanical stretch into intercalate carbon between MoS 2 layers. Our results open up the possibility of using MoS 2 nano tubes as templates for the synthesis of new one- dimensional binary phase systems. (Author)

Development and characterization of nanopore system for nano-vesicle analysis

Science.gov (United States)

Goyal, Gaurav

novel nano-bioanalytical platform that can be used to capture comprehensive size and deformability data on nano-vesicles with high temporal resolution.

Kelvin-Helmholtz instability: the ``atom'' of geophysical turbulence?

Science.gov (United States)

Smyth, William

2017-11-01

Observations of small-scale turbulence in Earth's atmosphere and oceans have most commonly been interpreted in terms of the Kolmogorov theory of isotropic turbulence, despite the fact that the observed turbulence is significantly anisotropic due to density stratification and sheared large-scale flows. I will describe an alternative picture in which turbulence consists of distinct events that occur sporadically in space and time. The simplest model for an individual event is the ``Kelvin-Helmholtz (KH) ansatz'', in which turbulence relieves the dynamic instability of a localized shear layer. I will summarize evidence that the KH ansatz is a valid description of observed turbulence events, using microstructure measurements from the equatorial Pacific ocean as an example. While the KH ansatz has been under study for many decades and is reasonably well understood, the bigger picture is much less clear. How are the KH events distributed in space and time? How do different events interact with each other? I will describe some tentative steps toward a more thorough understanding.

Nano-bio-sensing

CERN Document Server

Carrara, Sandro

2011-01-01

This book examines state-of-the-art applications of nano-bio-sensing. It brings together researchers from nano-electronics and bio-technology, providing multidisciplinary content from nano-structures fabrication to bio-sensing applications.

Development of a metallic magnetic calorimeter for high resolution spectroscopy

International Nuclear Information System (INIS)

Linck, M.

2007-01-01

In this thesis the development of a metallic magnetic calorimeter for high resolution detection of single x-ray quanta is described. The detector consists of an X-ray absorber and a paramagnetic temperature sensor. The raise in temperature of the paramagnetic sensor due to the absorption of a single X-ray is measured by the change in magnetization of the sensor using a low-noise SQUID magnetometer. The thermodynamic properties of the detector can be described by a theoretical model based on a mean field approximation. This allows for an optimization of the detector design with respect to signal size. The maximal archivable energy resolution is limited by thermodynamic energy fluctuations between absorber, heat bath and thermometer. An interesting field of application for a metallic magnetic calorimeter is X-ray astronomy and the investigation of X-ray emitting objects. Through high-resolution X-ray spectroscopy it is possible to obtain information about physical processes of even far distant objects. The magnetic calorimeter that was developed in this thesis has a metallic absorber with a quantum efficiency of 98% at 6 keV. The energy resolution of the magnetic calorimeter is EFWHM=2.7 eV at 5.9 keV. The deviation of the detector response from a linear behavior of the detector is only 0.8% at 5.9 keV. (orig.)

Note: Switching crosstalk on and off in Kelvin probe force microscopy

International Nuclear Information System (INIS)

Polak, Leo; Wijngaarden, Rinke J.; Man, Sven de

2014-01-01

In Kelvin Probe Force Microscopy (KPFM) electronic crosstalk can occur between the excitation signal and probe deflection signal. Here, we demonstrate how a small modification to our commercial instrument enables us to literally switch the crosstalk on and off. We study in detail the effect of crosstalk on open-loop KPFM and compare with closed-loop KPFM. We measure the pure crosstalk signal and verify that we can correct for it in the data-processing required for open-loop KPFM. We also demonstrate that open-loop KPFM results are independent of the frequency and amplitude of the excitation signal, provided that the influence of crosstalk has been eliminated

Kelvin probe force microscopy studies of the charge effects upon adsorption of carbon nanotubes and C60 fullerenes on hydrogen-terminated diamond

Science.gov (United States)

Kölsch, S.; Fritz, F.; Fenner, M. A.; Kurch, S.; Wöhrl, N.; Mayne, A. J.; Dujardin, G.; Meyer, C.

2018-01-01

Hydrogen-terminated diamond is known for its unusually high surface conductivity that is ascribed to its negative electron affinity. In the presence of acceptor molecules, electrons are expected to transfer from the surface to the acceptor, resulting in p-type surface conductivity. Here, we present Kelvin probe force microscopy (KPFM) measurements on carbon nanotubes and C60 adsorbed onto a hydrogen-terminated diamond(001) surface. A clear reduction in the Kelvin signal is observed at the position of the carbon nanotubes and C60 molecules as compared with the bare, air-exposed surface. This result can be explained by the high positive electron affinity of carbon nanotubes and C60, resulting in electron transfer from the surface to the adsorbates. When an oxygen-terminated diamond(001) is used instead, no reduction in the Kelvin signal is obtained. While the presence of a charged adsorbate or a difference in work function could induce a change in the KPFM signal, a charge transfer effect of the hydrogen-terminated diamond surface, by the adsorption of the carbon nanotubes and the C60 fullerenes, is consistent with previous theoretical studies.

NanoComposite Polymers for High Resolution Near Infrared Detectors

Data.gov (United States)

National Aeronautics and Space Administration — Develop nanocomposite materials with tuned refractive index in the near infra red spectral range as an index-matched immersion lens for high resolution infra-red...

Comparison between auricular and standard rectal thermometers for the measurement of body temperature in dogs.

Science.gov (United States)

Sousa, Marlos G; Carareto, Roberta; Pereira-Junior, Valdo A; Aquino, Monally C C

2011-04-01

Although the rectal mucosa remains the traditional site for measuring body temperature in dogs, an increasing number of clinicians have been using auricular temperature to estimate core body temperature. In this study, 88 mature healthy dogs had body temperatures measured with auricular and rectal thermometers. The mean temperature and confidence intervals were similar for each method, but Bland-Altman plots showed high biases and limits of agreement unacceptable for clinical purposes. The results indicate that auricular and rectal temperatures should not be interpreted interchangeably.

Environmental silicate nano-biocomposites

CERN Document Server

Pollet, Eric

2012-01-01

Environmental Silicate Nano-Biocomposites focuses on nano-biocomposites, which are obtained by the association of silicates such as bioclays with biopolymers. By highlighting recent developments and findings, green and biodegradable nano-composites from both renewable and biodegradable polymers are explored. This includes coverage of potential markets such as packaging, agricultures, leisure and the fast food industry. The knowledge and experience of more than twenty international experts in diverse fields, from chemical and biochemical engineering to applications, is brought together in four different sections covering: Biodegradable polymers and Silicates, Clay/Polyesters Nano-biocomposites, Clay/Agropolymers Nano-biocomposites, and Applications and biodegradation of Nano-biocomposites. By exploring the relationships between the biopolymer structures, the processes, and the final properties Environmental Silicate Nano-Biocomposites explains how to design nano-materials to develop new, valuable, environmenta...

Kelvin-Helmholtz instability and kinetic internal kink modes in tokamaks

International Nuclear Information System (INIS)

Naitou, H.

2002-01-01

The m=1 and n=1 kinetic internal kink (KIK) mode with a nonuniform density profile is studied by the cylindrical version of the gyro-reduced-MHD code which is one of the extended MHD codes being able to treat the physics beyond resistive MHD. Electron inertia and electron finite temperature effects are crucial. The linear mode structure of KIK mode includes the sheared poloidal flow with m=1, which excites the vortexes due to the Kelvin-Helmholtz (K-H) instability. We have found that there is a strong coupling between the KIK mode and the K-H mode even in the early nonlinear stage of KIK instability in which the width of the m=1 magnetic island is sufficiently small. (author)

Development of nano-sized α-Al2O3:C films for application in digital radiology

International Nuclear Information System (INIS)

Silva, Edna C.

2011-01-01

Ceramic materials are widely used as sensors for ionizing radiation. In nuclear applications, the alpha-alumina doped with carbon (α-Al 2 O 3 :C) is the most widely ceramic used because of its excellent optically stimulated luminescence (OSL) and thermoluminescent (TL) properties applied to detection of ionizing radiation. Another application of OSL and TL materials are in Digital Radiography, with ceramic/polymeric film composites. Recently, Computed Radiography (CR) devices based on OSL materials are replacing the old conventional film radiography. In this study we investigate the thermoluminescence of nano-sized α-Al 2 O 3 samples doped with different percentages of carbon, sintered in reducing atmospheres at temperatures ranging from 1300 to 1750 deg C. The results indicate that the nano-sized α-Al 2 O 3 :C materials have a luminescent response that could be due to both OSL and RPL properties, but without application to radiation dosimetry. Moreover, the results indicate that micro-sized α-Al 2 O 3 :C, doped with 0.5% carbon, and nano-sized ones doped with 2% of carbon, present thermoluminescent signal around 30 to 100 times the TL output signal of commercial TLD-100, the most used TL dosimeter in the world. The results indicate that these ceramic nano-particles have great potential for use in Digital Radiography based on thermoluminescent film imaging, being able to provide image resolutions much higher than the micro-sized α-Al 2 O 3 :C, in view of their improved resolution provided by nano-particulates. (author)

Sensing of single electrons using micro and nano technologies: a review

Science.gov (United States)

Jalil, Jubayer; Zhu, Yong; Ekanayake, Chandima; Ruan, Yong

2017-04-01

During the last three decades, the remarkable dynamic features of microelectromechanical systems (MEMS) and nanoelectromechanical systems (NEMS), and advances in solid-state electronics hold much potential for the fabrication of extremely sensitive charge sensors. These sensors have a broad range of applications, such as those involving the measurement of ionization radiation, detection of bio-analyte and aerosol particles, mass spectrometry, scanning tunneling microscopy, and quantum computation. Designing charge sensors (also known as charge electrometers) for electrometry is deemed significant because of the sensitivity and resolution issues in the range of micro- and nano-scales. This article reviews the development of state-of-the-art micro- and nano-charge sensors, and discusses their technological challenges for practical implementation.

Photoassisted Kelvin probe force microscopy at GaN surfaces: The role of polarity

Science.gov (United States)

Wei, J. D.; Li, S. F.; Atamuratov, A.; Wehmann, H.-H.; Waag, A.

2010-10-01

The behavior of GaN surfaces during photoassisted Kelvin probe force microscopy is demonstrated to be strongly dependant on surface polarity. The surface photovoltage of GaN surfaces illuminated with above-band gap light is analyzed as a function of time and light intensity. Distinct differences between Ga-polar and N-polar surfaces could be identified, attributed to photoinduced chemisorption of oxygen during illumination. These differences can be used for a contactless, nondestructive, and easy-performable analysis of the polarity of GaN surfaces.

A 10 nN resolution thrust-stand for micro-propulsion devices

Energy Technology Data Exchange (ETDEWEB)

Chakraborty, Subha; Courtney, Daniel G.; Shea, Herbert, E-mail: herbert.shea@epfl.ch [Microsystems for Space Technologies Laboratory (LMTS), Ecole Polytechnique Federale de Lausanne (EPFL), Neuchatel (Switzerland)

2015-11-15

We report on the development of a nano-Newton thrust-stand that can measure up to 100 μN thrust from different types of microthrusters with 10 nN resolution. The compact thrust-stand measures the impingement force of the particles emitted from a microthruster onto a suspended plate of size 45 mm × 45 mm and with a natural frequency over 50 Hz. Using a homodyne (lock-in) readout provides strong immunity to facility vibrations, which historically has been a major challenge for nano-Newton thrust-stands. A cold-gas thruster generating up to 50 μN thrust in air was first used to validate the thrust-stand. Better than 10 nN resolution and a minimum detectable thrust of 10 nN were achieved. Thrust from a miniature electrospray propulsion system generating up to 3 μN of thrust was measured with our thrust-stand in vacuum, and the thrust was compared with that computed from beam diagnostics, obtaining agreement within 50 nN to 150 nN. The 10 nN resolution obtained from this thrust-stand matches that from state-of-the-art nano-Newton thrust-stands, which measure thrust directly from the thruster by mounting it on a moving arm (but whose natural frequency is well below 1 Hz). The thrust-stand is the first of its kind to demonstrate less than 3 μN resolution by measuring the impingement force, making it capable of measuring thrust from different types of microthrusters, with the potential of easy upscaling for thrust measurement at much higher levels, simply by replacing the force sensor with other force sensors.

Data Encoding using Periodic Nano-Optical Features

Science.gov (United States)

Vosoogh-Grayli, Siamack

Successful trials have been made through a designed algorithm to quantize, compress and optically encode unsigned 8 bit integer values in the form of images using Nano optical features. The periodicity of the Nano-scale features (Nano-gratings) have been designed and investigated both theoretically and experimentally to create distinct states of variation (three on states and one off state). The use of easy to manufacture and machine readable encoded data in secured authentication media has been employed previously in bar-codes for bi-state (binary) models and in color barcodes for multiple state models. This work has focused on implementing 4 states of variation for unit information through periodic Nano-optical structures that separate an incident wavelength into distinct colors (variation states) in order to create an encoding system. Compared to barcodes and magnetic stripes in secured finite length storage media the proposed system encodes and stores more data. The benefits of multiple states of variation in an encoding unit are 1) increased numerically representable range 2) increased storage density and 3) decreased number of typical set elements for any ergodic or semi-ergodic source that emits these encoding units. A thorough investigation has targeted the effects of the use of multi-varied state Nano-optical features on data storage density and consequent data transmission rates. The results show that use of Nano-optical features for encoding data yields a data storage density of circa 800 Kbits/in2 via the implementation of commercially available high resolution flatbed scanner systems for readout. Such storage density is far greater than commercial finite length secured storage media such as Barcode family with maximum practical density of 1kbits/in2 and highest density magnetic stripe cards with maximum density circa 3 Kbits/in2. The numerically representable range of the proposed encoding unit for 4 states of variation is [0 255]. The number of

Mass production of polymer nano-wires filled with metal nano-particles.

Science.gov (United States)

Lomadze, Nino; Kopyshev, Alexey; Bargheer, Matias; Wollgarten, Markus; Santer, Svetlana

2017-08-17

Despite the ongoing progress in nanotechnology and its applications, the development of strategies for connecting nano-scale systems to micro- or macroscale elements is hampered by the lack of structural components that have both, nano- and macroscale dimensions. The production of nano-scale wires with macroscale length is one of the most interesting challenges here. There are a lot of strategies to fabricate long nanoscopic stripes made of metals, polymers or ceramics but none is suitable for mass production of ordered and dense arrangements of wires at large numbers. In this paper, we report on a technique for producing arrays of ordered, flexible and free-standing polymer nano-wires filled with different types of nano-particles. The process utilizes the strong response of photosensitive polymer brushes to irradiation with UV-interference patterns, resulting in a substantial mass redistribution of the polymer material along with local rupturing of polymer chains. The chains can wind up in wires of nano-scale thickness and a length of up to several centimeters. When dispersing nano-particles within the film, the final arrangement is similar to a core-shell geometry with mainly nano-particles found in the core region and the polymer forming a dielectric jacket.

Imaging of current density distributions with a Nb weak-link scanning nano-SQUID microscope

Science.gov (United States)

Shibata, Yusuke; Nomura, Shintaro; Kashiwaya, Hiromi; Kashiwaya, Satoshi; Ishiguro, Ryosuke; Takayanagi, Hideaki

2015-10-01

Superconducting quantum interference devices (SQUIDs) are accepted as one of the highest magnetic field sensitive probes. There are increasing demands to image local magnetic fields to explore spin properties and current density distributions in a two-dimensional layer of semiconductors or superconductors. Nano-SQUIDs have recently attracting much interest for high spatial resolution measurements in nanometer-scale samples. Whereas weak-link Dayem Josephson junction nano-SQUIDs are suitable to miniaturization, hysteresis in current-voltage (I-V) characteristics that is often observed in Dayem Josephson junction is not desirable for a scanning microscope. Here we report on our development of a weak-link nano-SQUIDs scanning microscope with small hysteresis in I-V curve and on reconstructions of two-dimensional current density vector in two-dimensional electron gas from measured magnetic field.

Fabrication of a mini multi-fixed-point cell for the calibration of industrial platinum resistance thermometers

Science.gov (United States)

Ragay-Enot, Monalisa; Lee, Young Hee; Kim, Yong-Gyoo

2017-07-01

A mini multi-fixed-point cell (length 118 mm, diameter 33 mm) containing three materials (In-Zn eutectic (mass fraction 3.8% Zn), Sn and Pb) in a single crucible was designed and fabricated for the easy and economical fixed-point calibration of industrial platinum resistance thermometers (IPRTs) for use in industrial temperature measurements. The melting and freezing behaviors of the metals were investigated and the phase transition temperatures were determined using a commercial dry-block calibrator. Results showed that the melting plateaus are generally easy to realize and are reproducible, flatter and of longer duration. On the other hand, the freezing process is generally difficult, especially for Sn, due to the high supercooling required to initiate freezing. The observed melting temperatures at optimum set conditions were 143.11 °C (In-Zn), 231.70 °C (Sn) and 327.15 °C (Pb) with expanded uncertainties (k  = 2) of 0.12 °C, 0.10 °C and 0.13 °C, respectively. This multi-fixed-point cell can be treated as a sole reference temperature-generating system. Based on the results, the realization of melting points of the mini multi-fixed-point cell can be recommended for the direct calibration of IPRTs in industrial applications without the need for a reference thermometer.

Towards quantitative analysis of core-shell catalyst nano-particles by aberration corrected high angle annular dark field STEM and EDX

International Nuclear Information System (INIS)

Haibo, E; Nellist, P D; Lozano-Perez, S; Ozkaya, D

2010-01-01

Core-shell structured heterogeneous catalyst nano-particles offer the promise of more efficient precious metal usage and also novel functionalities but are as yet poorly characterised due to large compositional variations over short ranges. High angle annular dark field detector in a scanning transmission electron microscope is frequently used to image at high resolution because of its Z-contrast and incoherent imaging process, but generally little attention is paid to quantification. Energy dispersive X-ray analysis provides information on thickness and chemical composition and, used in conjunction with HAADF-STEM, aids interpretation of imaged nano-particles. We present important calibrations and initial data for truly quantitative high resolution analysis.

KELVIN-HELMHOLTZ INSTABILITY OF A CORONAL STREAMER

Energy Technology Data Exchange (ETDEWEB)

Feng, L.; Gan, W. Q. [Key Laboratory of Dark Matter and Space Astronomy, Purple Mountain Observatory, Chinese Academy of Sciences, 210008 Nanjing (China); Inhester, B., E-mail: lfeng@pmo.ac.cn [Max-Planck-Institut fuer Sonnensystemforschung, Max-Planck-Str.2, D-37191 Katlenburg-Lindau (Germany)

2013-09-10

Shear-flow-driven instability can play an important role in energy transfer processes in coronal plasma. We present for the first time the observation of a kink-like oscillation of a streamer that is probably caused by the streaming kink-mode Kelvin-Helmholtz instability (KHI). The wave-like behavior of the streamer was observed by the Large Angle and Spectrometric Coronagraph Experiment C2 and C3 on board the SOlar and Heliospheric Observatory. The observed wave had a period of about 70-80 minutes, and its wavelength increased from 2 R{sub Sun} to 3 R{sub Sun} in about 1.5 hr. The phase speeds of its crests and troughs decreased from 406 {+-} 20 to 356 {+-} 31 km s{sup -1} during the event. Within the same heliocentric range, the wave amplitude also appeared to increase with time. We attribute the phenomena to the MHD KHI, which occurs at a neutral sheet in a fluid wake. The free energy driving the instability is supplied by the sheared flow and sheared magnetic field across the streamer plane. The plasma properties of the local environment of the streamer were estimated from the phase speed and instability threshold criteria.

Plasmonic graded nano-disks as nano-optical conveyor belt.

Science.gov (United States)

Kang, Zhiwen; Lu, Haifei; Chen, Jiajie; Chen, Kun; Xu, Fang; Ho, Ho-Pui

2014-08-11

We propose a plasmonic system consisting of nano-disks (NDs) with graded diameters for the realization of nano-optical conveyor belt. The system contains a couple of NDs with individual elements coded with different resonant wavelengths. By sequentially switching the wavelength and polarization of the excitation source, optically trapped target nano-particle can be transferred from one ND to another. The feasibility of such function is verified based on the three-dimensional finite-difference time-domain technique and the Maxwell stress tensor method. Our design may provide an alternative way to construct nano-optical conveyor belt with which target molecules can be delivered between trapping sites, thus enabling many on-chip optofluidic applications.

Solutions on high-resolution multiple configuration system sensors

Science.gov (United States)

Liu, Hua; Ding, Quanxin; Guo, Chunjie; Zhou, Liwei

2014-11-01

For aim to achieve an improved resolution in modern image domain, a method of continuous zoom multiple configuration, with a core optics is attempt to establish model by novel principle on energy transfer and high accuracy localization, by which the system resolution can be improved with a level in nano meters. A comparative study on traditional vs modern methods can demonstrate that the dialectical relationship and their balance is important, among Merit function, Optimization algorithms and Model parameterization. The effect of system evaluated criterion that MTF, REA, RMS etc. can support our arguments qualitatively.

The Effect of Nano Loading and Ultrasonic Compounding of EVA/LDPE/Nano-magnesium Hydroxide on Mechanical Properties and Distribution of Nano Particles

Science.gov (United States)

Azman, I. A.; Salleh, R. M.; Alauddin, S. M.; Shueb, M. I.

2018-05-01

Blends of Ethylene Vinyl Acetate (EVA) and Low-Density Polyethylene (LDPE) are promising composite which have good mechanical properties to environmental stress cracking. However, they lack fire resistant properties, which limits it usage in wire and cable industry. In order to improve flame retardancy ability, a range of nano-magnesium hydroxide (nano-MH) loading which is from 0 phr to maximum of 20 phr with ultrasonic extrusion 0-100 kHz frequencies have been introduced. Ultrasonic extrusion was used to improve the distribution of nano-MH. It was found that, 10 phr of nano loading with 100 kHz ultrasonic assisted has greater tensile strength compared to the nanocomposite without ultrasonication. Further increase of nano MH loading, will decrease the tensile properties. Better elongation at break was observed at10 phr nano-MH with the frequency of 50 kHz. The sample of 20 phr of nanoMH assisted with 50 kHz ultrasonic exhibits good flexural properties while 10 phr of nano-MH without the ultrasonic assisted demonstrates good in izod impact properties. From the evaluation of mechanical properties studied, it was found that 10 phr of nano-MH has shown the best performance among all the samples tested for EVA/LDPE/nano-MH composites. Transmission Electron Microscopy (TEM) has been conducted on 10 phr sample with different frequencies in order to observe the distribution of nano-MH particles. The sample with 100 kHz frequency shows more uniform dispersion of nano-MH in EVA/LDPE composites. This investigation indicates that the ultrasonic technology can enhance the mechanical properties studied as well as the dispersion of nano particles in the composite.

Characterization of nano structured metallic materials

International Nuclear Information System (INIS)

Marin A, M.; Gutierrez W, C.; Cruz C, R.; Angeles C, C.

1997-01-01

Nowadays the search of new materials with specific optical properties has carried out to realize a series of experiments through the polymer synthesis [(C 3 N 3 ) 2 (NH) 3 ] n doped with gold metallic nanoparticles. The thermal stability of a polymer is due to the presence of tyazine rings contained in the structure. The samples were characterized by High Resolution Transmission Electron Microscopy, X-ray diffraction by the Powder method, Ft-infrared and its thermal properties by Differential Scanning Calorimetry (DSC) and Thermogravimetry (TGA). One of the purposes of this work is to obtain nano structured materials over a polymeric matrix. (Author)

Dual harmonic Kelvin probe force microscopy at the graphene–liquid interface

International Nuclear Information System (INIS)

Collins, Liam; Rodriguez, Brian J.; Kilpatrick, Jason I.; Weber, Stefan A. L.; Vlassiouk, Ivan V.; Tselev, Alexander; Jesse, Stephen; Kalinin, Sergei V.

2014-01-01

Kelvin probe force microscopy (KPFM) is a powerful technique for the determination of the contact potential difference (CPD) between an atomic force microscope tip and a sample under ambient and vacuum conditions. However, for many energy storage and conversion systems, including graphene-based electrochemical capacitors, understanding electrochemical phenomena at the solid–liquid interface is paramount. Despite the vast potential to provide fundamental insight for energy storage materials at the nanoscale, KPFM has found limited applicability in liquid environments to date. Here, using dual harmonic (DH)-KPFM, we demonstrate CPD imaging of graphene in liquid. We find good agreement with measurements performed in air, highlighting the potential of DH-KPFM to probe electrochemistry at the graphene–liquid interface

Development of Nb nanoSQUIDs based on SNS junctions for operation in high magnetic fields

Energy Technology Data Exchange (ETDEWEB)

Morosh, Viacheslav; Kieler, Oliver; Weimann, Thomas; Zorin, Alexander [Physikalisch-Technische Bundesanstalt (PTB), Braunschweig (Germany); Mueller, Benedikt; Martinez-Perez, Maria Jose; Kleiner, Reinhold; Koelle, Dieter [Physikalisches Institut and Center for Quantum Science in LISA+, Universitaet Tuebingen (Germany)

2016-07-01

Investigation of the magnetization reversal of single magnetic nanoparticles requires SQUIDs with high spatial resolution, high spin sensitivity (a few Bohr magneton μ{sub B}) and at the same time sufficient stability in high magnetic fields. We fabricated dc nanoSQUIDs comprising overdamped SNS sandwich-type (Nb/HfTi/Nb) Josephson junctions using optimized technology based on combination of electron beam lithography and chemical-mechanical polishing. Our nanoSQUIDs have Josephson junctions with lateral dimensions ≤ 150 nm x 150 nm, effective loop areas < 0.05 μm{sup 2} and the distance between the Josephson junctions ≤ 100 nm. The feeding strip lines of the width ≤ 200 nm have been realized. The nanoSQUIDs have shown stable operation in external magnetic fields at least up to 250 mT. Sufficiently low level of flux noise resulting in spin sensitivity of few tens μ{sub B}/Hz{sup 1/2} has been demonstrated. A further reduction of the nanoSQUID size using our technology is possible.

Nonlinear evolution of the magnetized Kelvin-Helmholtz instability: From fluid to kinetic modeling

Czech Academy of Sciences Publication Activity Database

Henri, P.; Cerri, S.S.; Califano, F.; Pegoraro, F.; Rossi, C.; Faganello, M.; Šebek, Ondřej; Trávníček, Pavel M.; Hellinger, Petr; Frederiksen, J. T.; Nordlund, A.; Markidis, S.; Keppens, R.; Lapenta, G.

2013-01-01

Roč. 20, č. 10 (2013), 102118/1-102118/13 ISSN 1070-664X R&D Projects: GA MŠk(CZ) 7E11053 EU Projects: European Commission(XE) 263340 - SWIFF Grant - others:European Commission(XE) HPC-EUROPA2 - No. 228398; EU(XE) RI-283493; NASA (US) NNX11A1164G Institutional support: RVO:67985815 ; RVO:68378289 Keywords : Kelvin-Helmholtz instability * plasma kinetic theory * plasma magnetohydrodynamics Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics; BL - Plasma and Gas Discharge Physics (UFA-U) Impact factor: 2.249, year: 2013

Calibrated work function mapping by Kelvin probe force microscopy

Science.gov (United States)

Fernández Garrillo, Pablo A.; Grévin, Benjamin; Chevalier, Nicolas; Borowik, Łukasz

2018-04-01

We propose and demonstrate the implementation of an alternative work function tip calibration procedure for Kelvin probe force microscopy under ultrahigh vacuum, using monocrystalline metallic materials with known crystallographic orientation as reference samples, instead of the often used highly oriented pyrolytic graphite calibration sample. The implementation of this protocol allows the acquisition of absolute and reproducible work function values, with an improved uncertainty with respect to unprepared highly oriented pyrolytic graphite-based protocols. The developed protocol allows the local investigation of absolute work function values over nanostructured samples and can be implemented in electronic structures and devices characterization as demonstrated over a nanostructured semiconductor sample presenting Al0.7Ga0.3As and GaAs layers with variable thickness. Additionally, using our protocol we find that the work function of annealed highly oriented pyrolytic graphite is equal to 4.6 ± 0.03 eV.

Interrogating Host-virus Interactions and Elemental Transfer Using NanoSIMS

Science.gov (United States)

Pasulka, A.; Thamatrakoln, K.; Poulos, B.; Bidle, K. D.; Sullivan, M. B.; Orphan, V. J.

2016-02-01

Marine viruses (bacteriophage and eukaryotic viruses) impact microbial food webs by influencing microbial community structure, carbon and nutrient flow, and serving as agents of gene transfer. While the collective impact of viral activity has become more apparent over the last decade, there is a growing need for single-cell and single-virus level measurements of the associated carbon and nitrogen transfer, which ultimately shape the biogeochemical impact of viruses in the upper ocean. Stable isotopes have been used extensively for understanding trophic relationships and elemental cycling in marine food webs. While single-cell isotope approaches such as nanoscale secondary ion mass spectrometry (nanoSIMS) have been more readily used to study trophic interactions between microorganisms, isotopic enrichment in viruses has not been described. Here we used nanoSIMS to quantify the transfer of stable isotopes (13C and 15N) from host to individual viral particles in two distinct unicellular algal-virus model systems. These model systems represent a eukaryotic phytoplankton (Emiliania huxleyi strain CCMP374) and its 200nm coccolithovirus (EhV207), as well as a cyanobacterial phytoplankton (Synechococcus WH8101) and its 80nm virus (Syn1). Host cells were grown on labeled media for multiple generations, subjected to viral infection, and then viruses were harvested after lysis. In both cases, nanoSIMS measurements were able to detect 13C and 15N in the resulting viral particles significantly above the background noise. The isotopic enrichment in the viral particles mirrored that of the host. Through use of these laboratory model systems, we quantified the sensitivity (ion counts), spatial resolution, and reproducibility, including sources of methodological and biological variability, in stable isotope incorporation into viral particles. Our findings suggest that nanoSIMS can be successfully employed to directly probe virus-host interactions at the resolution of individual

Are nano-composites and nano-ionomers suitable for orthodontic bracket bonding?

Science.gov (United States)

Uysal, Tancan; Yagci, Ahmet; Uysal, Banu; Akdogan, Gülsen

2010-02-01

The aim of this study was to test nano-composite (Filtek Supreme Plus Universal) and a newly introduced nano-ionomer (Ketac N100 Light Curing Nano-Ionomer) restorative to determine their shear bond strength (SBS) and failure site locations in comparison with a conventional light-cure orthodontic bonding adhesive (Transbond XT). Sixty freshly extracted human maxillary premolar teeth were arbitrarily divided into three equal groups. The brackets were bonded to the teeth in each group with different composites, according to the manufacturers' instructions. The SBS values of the brackets were recorded in Megapascals (MPa) using a universal testing machine. Adhesive remnant index scores were determined after failure of the brackets. The data were analysed using analysis of variance, Tukey honestly significant difference, and chi-square tests. The results demonstrated that group 1 (Transbond XT, mean: 12.60 +/- 4.48 MPa) had a higher SBS than that of group 2 (nano-composite, mean: 8.33 +/- 5.16 MPa; P nano-ionomer, mean: 6.14 +/- 2.12 MPa; P Nano-composites and nano-ionomers may be suitable for bonding since they fulfil the previously suggested SBS ranges for clinical acceptability, but they are inferior to a conventional orthodontic composite.

Preparation, Characterization, and Modeling of Carbon Nano fiber/Epoxy Nano composites

International Nuclear Information System (INIS)

Sun, L.H.; Yang, Z.G.; Ounaies, Z.; Whalen, C.A.; Gao, X.L.

2011-01-01

There is a lack of systematic investigations on both mechanical and electrical properties of carbon nano fiber (CNF)-reinforced epoxy matrix nano composites. In this paper, an in-depth study of both static and dynamic mechanical behaviors and electrical properties of CNF/epoxy nano composites with various contents of CNFs is provided. A modified Halpin-Tsai equation is used to evaluate the Young's modulus and storage modulus of the nano composites. The values of Young's modulus predicted using this method account for the effect of the CNF agglomeration and fit well with those obtained experimentally. The results show that the highest tensile strength is found in the epoxy nano composite with a 1.0 wt % CNFs. The alternate-current (AC) electrical properties of the CNF/epoxy nano composites exhibit a typical insulator-conductor transition. The conductivity increases by four orders of magnitude with the addition of 0.1 wt % (0.058 vol %) CNFs and by ten orders of magnitude for nano composites with CNF volume fractions higher than 1.0 wt % (0.578 vol %). The percolation threshold (i.e., the critical CNF volume fraction) is found to be at 0.057 vol %.

Green chemistry synthesis of nano-cuprous oxide.

Science.gov (United States)

Ceja-Romero, L R; Ortega-Arroyo, L; Ortega Rueda de León, J M; López-Andrade, X; Narayanan, J; Aguilar-Méndez, M A; Castaño, V M

2016-04-01

Green chemistry and a central composite design, to evaluate the effect of reducing agent, temperature and pH of the reaction, were employed to produce controlled cuprous oxide (Cu2O) nanoparticles. Response surface method of the ultraviolet-visible spectroscopy is allowed to determine the most relevant factors for the size distribution of the nanoCu2O. X-ray diffraction reflections correspond to a cubic structure, with sizes from 31.9 to 104.3 nm. High-resolution transmission electron microscopy reveals that the different shapes depend strongly on the conditions of the green synthesis.

Methods for measurement of electron emission yield under low energy electron-irradiation by collector method and Kelvin probe method

Energy Technology Data Exchange (ETDEWEB)

Tondu, Thomas; Belhaj, Mohamed; Inguimbert, Virginie [Onera, DESP, 2 Avenue Edouard Belin, 31400 Toulouse (France); Onera, DESP, 2 Avenue Edouard Belin, 31400 Toulouse, France and Fondation STAE, 4 allee Emile Monso, BP 84234-31432, Toulouse Cedex 4 (France); Onera, DESP, 2 Avenue Edouard Belin, 31400 Toulouse (France)

2010-09-15

Secondary electron emission yield of gold under electron impact at normal incidence below 50 eV was investigated by the classical collector method and by the Kelvin probe method. The authors show that biasing a collector to ensure secondary electron collection while keeping the target grounded can lead to primary electron beam perturbations. Thus reliable secondary electron emission yield at low primary electron energy cannot be obtained with a biased collector. The authors present two collector-free methods based on current measurement and on electron pulse surface potential buildup (Kelvin probe method). These methods are consistent, but at very low energy, measurements become sensitive to the earth magnetic field (below 10 eV). For gold, the authors can extrapolate total emission yield at 0 eV to 0.5, while a total electron emission yield of 1 is obtained at 40{+-}1 eV.

Methods for measurement of electron emission yield under low energy electron-irradiation by collector method and Kelvin probe method

International Nuclear Information System (INIS)

Tondu, Thomas; Belhaj, Mohamed; Inguimbert, Virginie

2010-01-01

Secondary electron emission yield of gold under electron impact at normal incidence below 50 eV was investigated by the classical collector method and by the Kelvin probe method. The authors show that biasing a collector to ensure secondary electron collection while keeping the target grounded can lead to primary electron beam perturbations. Thus reliable secondary electron emission yield at low primary electron energy cannot be obtained with a biased collector. The authors present two collector-free methods based on current measurement and on electron pulse surface potential buildup (Kelvin probe method). These methods are consistent, but at very low energy, measurements become sensitive to the earth magnetic field (below 10 eV). For gold, the authors can extrapolate total emission yield at 0 eV to 0.5, while a total electron emission yield of 1 is obtained at 40±1 eV.

International comparison of resistance thermometers between NMIs from Spain, Mexico and Andean countries

Science.gov (United States)

del Campo, D.; Ruiz, V. C.; Méndez-Lango, E.; Córdova, L.; von Borries, E.; Sánchez, C. A.; Arévalo, A.; Aguilera, B.; Guillén, E.; Cabrera, C.; Quintana, L.

2013-09-01

An international comparison on semi-standard Platinum Resistance Thermometers (PRTs) among the National Metrology Institutes (NMIs) of Spain, Mexico and the Andean Countries (Bolivia, Colombia, Ecuador, Peru and Venezuela) began in 2004 and was successfully completed in 2005. Two PRTs were circulated (hand carried) and compared from -40 °C up to 250 °C. The Centro Español de Metrología (Spanish NMI), CEM, was the pilot laboratory and the Centro Nacional de Metrología (Mexican NMI), CENAM, was the co-pilot laboratory. This paper shows the details of the comparison and the final results as they were presented in the approved final report of the comparison in September of 2005.

Kelvin wave coupling from TIMED and GOCE: Inter/intra-annual variability and solar activity effects

Science.gov (United States)

Gasperini, Federico; Forbes, Jeffrey M.; Doornbos, Eelco N.; Bruinsma, Sean L.

2018-06-01

The primary mechanism through which energy and momentum are transferred from the lower atmosphere to the thermosphere is through the generation and propagation of atmospheric waves. It is becoming increasingly evident that a few waves from the tropical wave spectrum preferentially propagate into the thermosphere and contribute to modify satellite drag. Two of the more prominent and well-established tropical waves are Kelvin waves: the eastward-propagating 3-day ultra-fast Kelvin wave (UFKW) and the eastward-propagating diurnal tide with zonal wave number 3 (DE3). In this work, Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) temperatures at 110 km and Gravity field and steady-state Ocean Circulation Explorer (GOCE) neutral densities and cross-track winds near 260 km are used to demonstrate vertical coupling in this height regime due to the UFKW and DE3. Significant inter- and intra-annual variability is found in DE3 and the UFKW, with evidence of latitudinal broadening and filtering of the latitude structures with height due to the effect of dissipation and mean winds. Additionally, anti-correlation between the vertical penetration of these waves to the middle thermosphere and solar activity level is established and explained through the effect of molecular dissipation.

Metabolic activity of uncultivated magnetotactic bacteria revealed by NanoSIMS

Science.gov (United States)

He, M.; Zhang, W.; Gu, L.; Pan, Y.; Lin, W.

2017-12-01

Microorganisms that exhibit magnetotaxis behavior, collectively known as the magnetotactic bacteria (MTB), are those whose motility is influenced by the Earth's magnetic field. MTB are a physiologically diverse group of bacteria with a unique feature of intracellular biomineralization of magnetosomes (Fe3O4 and/or Fe3S4) (Bazylinski et al., 2013). However, the ecophysiology of uncultivated MTB, especially those within the Nitrospirae phylum forming hundreds of bullet-shaped magnetite magnetosomes per cell, is still not well characterized (Lin et al., 2014). Nanoscale secondary ion mass spectrometry (NanoSIMS) is a powerful tool for revealing element distribution in nanometer-scale resolution, which opens exciting possibilities for the study of interactions between microorganisms and environments (Gao et al., 2016; Musat et al., 2016). Here we applied NanoSIMS to investigate the dynamics of carbon and nitrogen assimilations in two magnetotactic Nitrospirae populations at single cell level. Our NanoSIMS results confirmed the metabolic potential of Nitrospirae MTB proposed by genomic and metagenomic analysis and provided additional insights into the ecophysiology of uncultivated MTB. This study suggests that NanoSIMS-based analyses are powerful approaches for investigating and characterizing the ecological function of environmental microorganisms. References: Bazylinski D A., Lefèvre, C T., Schüler D., 2013. Magnetotactic Bacteria. 453-494.Lin W, Bazylinski DA, Xiao T, Wu L- F, Pan Y., 2014. Life with compass: diversity and biogeography of magnetotactic bacteria. Environ Microbiol, 16: 1462-2920.Gao D., Huang X., Tao Y., 2016. A critical review of NanoSIMS in analysis of microbial metabolic activities at single-cell level. Crit Rev Biotechnol, 36: 884-890.Musat N., Musat F., Weber PK., Pett-Ridge J., 2016. Tracking microbial interactions with NanoSIMS. Curr Opin Biotechnol, 41: 114-121.

Physical and magnetic properties of (Ba/Sr) substituted magnesium nano ferrites

Science.gov (United States)

Ateia, Ebtesam E.; Takla, E.; Mohamed, Amira T.

2017-10-01

In the presented paper, strontium (Sr) and barium (Ba) nano ferrites were synthesized by citrate auto combustion method. The investigated samples are characterized by X-ray diffraction technique (XRD), field emission scanning electron microscopy, high resolution transmission electron microscopy and energy dispersive X-ray spectroscopy. The structural properties of the obtained samples were examined by XRD analysis showing that the synthesized nanoparticles are in cubic spinel structure. The average crystallite sizes are in the range of 22.66 and 21.95 nm for Mg0.7Ba0.3Fe2O4 and Mg0.7 Sr0.3Fe2O4 respectively. The VSM analysis confirms the existence of ferromagnetic nature of Sr2+/Ba2+ substituted magnesium nano particles. Exchange interaction between hard (Sr/Ba) and soft (Mg) magnetic phases improves the structural and magnetic properties of nano ferrite particles. Rigidity modulus, longitudinal and shear wave velocities are predicted theoretically from Raman spectroscopy and structural data of the investigated spinel ferrite. The magnetic and structural properties of magnesium are enhanced by doping with barium and strontium nano particles. The saturation magnetization, remanent magnetization and coercivity reported on vibrating sample magnetometer curve illustrate the promising industrial and magnetic recording applications of the prepared samples.

Elemental and isotopic imaging of biological samples using NanoSIMS.

Science.gov (United States)

Kilburn, Matt R; Clode, Peta L

2014-01-01

With its low detection limits and the ability to analyze most of the elements in the periodic table, secondary ion mass spectrometry (SIMS) represents one of the most versatile in situ analytical techniques available, and recent developments have resulted in significant advantages for the use of imaging mass spectrometry in biological and biomedical research. Increases in spatial resolution and sensitivity allow detailed interrogation of samples at relevant scales and chemical concentrations. Advances in dynamic SIMS, specifically with the advent of NanoSIMS, now allow the tracking of stable isotopes within biological systems at subcellular length scales, while static SIMS combines subcellular imaging with molecular identification. In this chapter, we present an introduction to the SIMS technique, with particular reference to NanoSIMS, and discuss its application in biological and biomedical research.

NanoAODs

CERN Document Server

Husova, Lucia Anna

2017-01-01

The scientist on LHC experiment analyse a huge amount of data every day on the Grid. Thus new methods are requested, how to make the analysis more efficient. The NanoAOD is a derived dataset from AOD, where only information necessary for the analysis is stored. Thus the analysis can be more than two times faster, because of the smaller file size, which can be read faster on the Grid. The main goal of this summer student project was to help other users to start using NanoAODs by rewriting their user tasks. Two example users tasks were converted to NanoAODs and tested with the local train test. A speed up of 3.5 was reached. The results of the analysis tasks are identical independent if they use AODs or NanoAODs.

A broadening temperature sensitivity range with a core-shell YbEr@YbNd double ratiometric optical nanothermometer

Science.gov (United States)

Marciniak, L.; Prorok, K.; Francés-Soriano, L.; Pérez-Prieto, J.; Bednarkiewicz, A.

2016-02-01

The chemical architecture of lanthanide doped core-shell up-converting nanoparticles can be engineered to purposely design the properties of luminescent nanomaterials, which are typically inaccessible to their homogeneous counterparts. Such an approach allowed to shift the up-conversion excitation wavelength from ~980 to the more relevant ~808 nm or enable Tb or Eu up-conversion emission, which was previously impossible to obtain or inefficient. Here, we address the issue of limited temperature sensitivity range of optical lanthanide based nano-thermometers. By covering Yb-Er co-doped core nanoparticles with the Yb-Nd co-doped shell, we have intentionally combined temperature dependent Er up-conversion together with temperature dependent Nd --> Yb energy transfer, and thus have expanded the temperature response range ΔT of a single nanoparticle based optical nano-thermometer under single ~808 nm wavelength photo-excitation from around ΔT = 150 K to over ΔT = 300 K (150-450 K). Such engineered nanocrystals are suitable for remote optical temperature measurements in technology and biotechnology at the sub-micron scale.The chemical architecture of lanthanide doped core-shell up-converting nanoparticles can be engineered to purposely design the properties of luminescent nanomaterials, which are typically inaccessible to their homogeneous counterparts. Such an approach allowed to shift the up-conversion excitation wavelength from ~980 to the more relevant ~808 nm or enable Tb or Eu up-conversion emission, which was previously impossible to obtain or inefficient. Here, we address the issue of limited temperature sensitivity range of optical lanthanide based nano-thermometers. By covering Yb-Er co-doped core nanoparticles with the Yb-Nd co-doped shell, we have intentionally combined temperature dependent Er up-conversion together with temperature dependent Nd --> Yb energy transfer, and thus have expanded the temperature response range ΔT of a single nanoparticle

Kelvin-Helmholtz instability in a bounded plasma flow

International Nuclear Information System (INIS)

Burinskaya, T. M.

2008-01-01

Kelvin-Helmholtz instability in a three-layer plane geometry is investigated theoretically. It is shown that, in a three-layer system (in contrast to the traditionally considered case in which instability develops at the boundary between two plasma flows), instability can develop at an arbitrary ratio of the plasma flow velocity to the ion-acoustic velocity. Perturbations with wavelengths on the order of the flow thickness or longer can increase even at a zero temperature. The system can also be unstable against long-wavelength perturbations if the flow velocity at one of the boundaries is lower than the sum of the Alfven velocities in the flow and the ambient plasma. The possibility of applying the results obtained to interpret the experimental data acquired in the framework of the CLUSTER multisatellite project is discussed. It follows from these data that, in many cases, the propagation of an accelerated particle flow in the plasma-sheet boundary layer of the Earth's magnetotail is accompanied by the generation of magnetic field oscillations propagating with a velocity on the order of the local Alfven velocity.

Micro/nano analysis of tooth microstructures by Focused Ion Beam (FIB cross-sectioning

Directory of Open Access Journals (Sweden)

Meltem Sezen

2017-04-01

Full Text Available Since dental structures are hard and fragile, cross-sectioning of these materials using ultramicrotomy and other techniques and following micro and nano analysis cause problems. The use of FIB-SEM dual beam platforms is the most convenient solution for investigating the microstructures, site-specifically and in certain geometries. Dual beam platforms allow for imaging at high magnifications and resolutions and simultaneous elemental analysis. In this study, the micro/nano-structural and chemical differences were revealed in dentin and enamel samples. The investigation of dental tissues having different morphologies and chemical components by ion-cross-sectioning is important for the use of FIB-SEM platforms in dentistry in Turkey.

Atomic resolution scanning tunneling microscopy in a cryogen free dilution refrigerator at 15 mK

International Nuclear Information System (INIS)

Haan, A. M. J. den; Wijts, G. H. C. J.; Galli, F.; Oosterkamp, T. H.; Usenko, O.; Baarle, G. J. C. van; Zalm, D. J. van der

2014-01-01

Pulse tube refrigerators are becoming more common, because they are cost efficient and demand less handling than conventional (wet) refrigerators. However, a downside of a pulse tube system is the vibration level at the cold-head, which is in most designs several micrometers. We implemented vibration isolation techniques which significantly reduced vibration levels at the experiment. These optimizations were necessary for the vibration sensitive magnetic resonance force microscopy experiments at milli-kelvin temperatures for which the cryostat is intended. With these modifications we show atomic resolution scanning tunneling microscopy on graphite. This is promising for scanning probe microscopy applications at very low temperatures

Electrochemically synthesized Si nano wire arrays and thermoelectric nano structures

International Nuclear Information System (INIS)

Khuan, N.I.; Ying, K.K.; Nur Ubaidah Saidin; Foo, C.T.

2012-01-01

Thermoelectric nano structures hold great promise for capturing and directly converting into electricity some vast amount of low-grade waste heats now being lost to the environment (for example from nuclear power plant, fossil fuel burning, automotive and household appliances). In this study, large-area vertically-aligned silicon nano wire (SiNW) arrays were synthesized in an aqueous solution containing AgNO 3 and HF on p-type Si (100) substrate by self-selective electroless etching process. The etching conditions were systematically varied in order to achieve different stages of nano wire formation. Diameters of the SiNWs obtained varied from approximately 50 to 200 nm and their lengths ranged from several to a few tens of μm. Te/ Bi 2 Te 3 -Si thermoelectric core-shell nano structures were subsequently obtained via galvanic displacement of SiNWs in acidic HF electrolytes containing HTeO 2 + and Bi 3+ / HTeO 2 + ions. The reactions were basically a nano-electrochemical process due to the difference in redox potentials between the materials. the surface-modified SiNWs of core-shell structures had roughened surface morphologies and therefore, higher surface-t-bulk ratios compared to unmodified SiNWs. They have potential applications in sensors, photovoltaic and thermoelectric nano devices. Growth study on the SiNWs and core-shell nano structures produced is presented using various microscopy, diffraction and probe-based techniques for microstructural, morphological and chemical characterizations. (Author)

3D positioning scheme exploiting nano-scale IR-UWB orthogonal pulses.

Science.gov (United States)

Kim, Nammoon; Kim, Youngok

2011-10-04

In these days, the development of positioning technology for realizing ubiquitous environments has become one of the most important issues. The Global Positioning System (GPS) is a well-known positioning scheme, but it is not suitable for positioning in in-door/building environments because it is difficult to maintain line-of-sight condition between satellites and a GPS receiver. To such problem, various positioning methods such as RFID, WLAN, ZigBee, and Bluetooth have been developed for indoor positioning scheme. However, the majority of positioning schemes are focused on the two-dimension positioning even though three-dimension (3D) positioning information is more useful especially in indoor applications, such as smart space, U-health service, context aware service, etc. In this paper, a 3D positioning system based on mutually orthogonal nano-scale impulse radio ultra-wideband (IR-UWB) signals and cross array antenna is proposed. The proposed scheme uses nano-scale IR-UWB signals providing fine time resolution and high-resolution multiple signal specification algorithm for the time-of-arrival and the angle-of-arrival estimation. The performance is evaluated over various IEEE 802.15.4a channel models, and simulation results show the effectiveness of proposed scheme.

Combinatorial Nano-Bio Interfaces.

Science.gov (United States)

Cai, Pingqiang; Zhang, Xiaoqian; Wang, Ming; Wu, Yun-Long; Chen, Xiaodong

2018-06-08

Nano-bio interfaces are emerging from the convergence of engineered nanomaterials and biological entities. Despite rapid growth, clinical translation of biomedical nanomaterials is heavily compromised by the lack of comprehensive understanding of biophysicochemical interactions at nano-bio interfaces. In the past decade, a few investigations have adopted a combinatorial approach toward decoding nano-bio interfaces. Combinatorial nano-bio interfaces comprise the design of nanocombinatorial libraries and high-throughput bioevaluation. In this Perspective, we address challenges in combinatorial nano-bio interfaces and call for multiparametric nanocombinatorics (composition, morphology, mechanics, surface chemistry), multiscale bioevaluation (biomolecules, organelles, cells, tissues/organs), and the recruitment of computational modeling and artificial intelligence. Leveraging combinatorial nano-bio interfaces will shed light on precision nanomedicine and its potential applications.

Nano-scale Materials and Nano-technology Processes in Environmental Protection

International Nuclear Information System (INIS)

Vissokov, Gh; Tzvetkoff, T.

2003-01-01

A number of environmental and energy technologies have benefited substantially from nano-scale technology: reduced waste and improved energy efficiency; environmentally friendly composite structures; waste remediation; energy conversion. In this report examples of current achievements and paradigm shifts are presented: from discovery to application; a nano structured materials; nanoparticles in the environment (plasma chemical preparation); nano-porous polymers and their applications in water purification; photo catalytic fluid purification; hierarchical self-assembled nano-structures for adsorption of heavy metals, etc. Several themes should be considered priorities in developing nano-scale processes related to environmental management: 1. To develop understanding and control of relevant processes, including protein precipitation and crystallisation, desorption of pollutants, stability of colloidal dispersion, micelle aggregation, microbe mobility, formation and mobility of nanoparticles, and tissue-nanoparticle interaction. Emphasis should be given to processes at phase boundaries (solid-liquid, solid-gas, liquid-gas) that involve mineral and organic soil components, aerosols, biomolecules (cells, microbes), bio tissues, derived components such as bio films and membranes, and anthropogenic additions (e.g. trace and heavy metals); 2. To carry out interdisciplinary research that initiates Noel approaches and adopts new methods for characterising surfaces and modelling complex systems to problems at interfaces and other nano-structures in the natural environment, including those involving biological or living systems. New technological advances such as optical traps, laser tweezers, and synchrotrons are extending examination of molecular and nano-scale processes to the single-molecule or single-cell level; 3. To integrate understanding of the roles of molecular and nano-scale phenomena and behaviour at the meso- and/or macro-scale over a period of time

Development of nano-sized {alpha}-Al{sub 2}O{sub 3}:C films for application in digital radiology

Energy Technology Data Exchange (ETDEWEB)

Silva, Edna C., E-mail: edca@cdtn.b [Universidade Federal de Minas Gerais (DEN/UFMG), Belo Horizonte (Brazil). Dept. de Engenharia Nuclear; Fontainha, Crissia C. [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte (Brazil). Dept. de Propedeutica Complemetar; Oliveira, Vitor H.; Ferraz, Wilmar B.; Faria, Luiz O. [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

2011-07-01

Ceramic materials are widely used as sensors for ionizing radiation. In nuclear applications, the alpha-alumina doped with carbon ({alpha}-Al{sub 2}O{sub 3}:C) is the most widely ceramic used because of its excellent optically stimulated luminescence (OSL) and thermoluminescent (TL) properties applied to detection of ionizing radiation. Another application of OSL and TL materials are in Digital Radiography, with ceramic/polymeric film composites. Recently, Computed Radiography (CR) devices based on OSL materials are replacing the old conventional film radiography. In this study we investigate the thermoluminescence of nano-sized {alpha}-Al{sub 2}O{sub 3} samples doped with different percentages of carbon, sintered in reducing atmospheres at temperatures ranging from 1300 to 1750 deg C. The results indicate that the nano-sized {alpha}-Al{sub 2}O{sub 3}:C materials have a luminescent response that could be due to both OSL and RPL properties, but without application to radiation dosimetry. Moreover, the results indicate that micro-sized {alpha}-Al{sub 2}O{sub 3}:C, doped with 0.5% carbon, and nano-sized ones doped with 2% of carbon, present thermoluminescent signal around 30 to 100 times the TL output signal of commercial TLD-100, the most used TL dosimeter in the world. The results indicate that these ceramic nano-particles have great potential for use in Digital Radiography based on thermoluminescent film imaging, being able to provide image resolutions much higher than the micro-sized {alpha}-Al{sub 2}O{sub 3}:C, in view of their improved resolution provided by nano-particulates. (author)

ON NANO Λg-CLOSED SETS

OpenAIRE

Rajasekaran, Ilangovan; Nethaji, Ochanan

2017-01-01

Abstaract−In this paper, we introduce nano ∧g-closed sets in nano topological spaces. Some properties of nano ∧g-closed sets and nano ∧g-open sets are weaker forms of nano closed sets and nano open sets

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

International Nuclear Information System (INIS)

Deng, J; Troadec, C; Joachim, C

2009-01-01

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

A Field Assessment of a Prototype Meter for Measuring the Wet-Bulb Globe-Thermometer Index

Science.gov (United States)

Walters, J. D.

1968-01-01

A prototype electronic instrument for the direct measurement of the wet-bulb globe-thermometer index is described. An assessment is made of its accuracy, as compared with W.B.G.T. indices calculated from conventional thermometric data, and a comparison is made between W.B.G.T. values read from the meter and effective or corrected effective temperatures derived from separate thermometric and air velocity recording instruments in the same climates. The instrument proved to be reliable and accurate over a wide range of climates and is a useful self-contained device for use in habitability surveys and similar investigations. Images PMID:5663429

Linear and ultrafast nonlinear plasmonics of single nano-objects

Science.gov (United States)

Crut, Aurélien; Maioli, Paolo; Vallée, Fabrice; Del Fatti, Natalia

2017-03-01

Single-particle optical investigations have greatly improved our understanding of the fundamental properties of nano-objects, avoiding the spurious inhomogeneous effects that affect ensemble experiments. Correlation with high-resolution imaging techniques providing morphological information (e.g. electron microscopy) allows a quantitative interpretation of the optical measurements by means of analytical models and numerical simulations. In this topical review, we first briefly recall the principles underlying some of the most commonly used single-particle optical techniques: near-field, dark-field, spatial modulation and photothermal microscopies/spectroscopies. We then focus on the quantitative investigation of the surface plasmon resonance (SPR) of metallic nano-objects using linear and ultrafast optical techniques. While measured SPR positions and spectral areas are found in good agreement with predictions based on Maxwell’s equations, SPR widths are strongly influenced by quantum confinement (or, from a classical standpoint, surface-induced electron scattering) and, for small nano-objects, cannot be reproduced using the dielectric functions of bulk materials. Linear measurements on single nano-objects (silver nanospheres and gold nanorods) allow a quantification of the size and geometry dependences of these effects in confined metals. Addressing the ultrafast response of an individual nano-object is also a powerful tool to elucidate the physical mechanisms at the origin of their optical nonlinearities, and their electronic, vibrational and thermal relaxation processes. Experimental investigations of the dynamical response of gold nanorods are shown to be quantitatively modeled in terms of modifications of the metal dielectric function enhanced by plasmonic effects. Ultrafast spectroscopy can also be exploited to unveil hidden physical properties of more complex nanosystems. In this context, two-color femtosecond pump-probe experiments performed on individual

Enantiomeric separation of some demethylated analogues of clofibric acid by capillary zone electrophoresis and nano-liquid chromatography.

Science.gov (United States)

Fantacuzzi, Marialuigia; Bettoni, Giancarlo; D'Orazio, Giovanni; Fanali, Salvatore

2006-03-01

The enantiomeric separation of some demethylated analogues of clofibric acid, namely 2-(6-chloro-benzothiazol-2-ylsulfanyl)-, 2-(6-methoxy-benzothiazol-2-ylsulfanyl)-, 2-(quinolin-2-yloxy)-, 2-(6-chloro-quinolin-2-yloxy)-, 2-(7-chloro-quinolin-4-yloxy)-propionic acid (compounds A-E, respectively), has been studied by CZE and nano-LC using for the first technique two beta-CD derivatives and vancomycin added to the BGE and vancomycin-modified silica particles for the second one, with the aim to find the optimum experimental conditions for the baseline resolution. The type and the concentration of the chiral selector added to the BGE, the buffer pH, the type of organic modifier and its concentration, the capillary temperature and the applied voltage played a very important role in the enantioresolution of the analysed compounds. The use of 6-monodeoxy-6-monoamino-beta-CD allowed to achieve baseline resolution of four of five clofibric acid derivatives in less than 10 min while heptakis-(2,3,6-tri-O-methyl)-beta-CD partially resolved the same compounds in their enantiomers. Employing vancomycin as the chiral selector in CZE, the counter-current partial filling method was chosen achieving baseline resolution of four analytes. All the studied compounds were enantioresolved employing a capillary column packed with vancomycin stationary phase by nano-LC, and the resolution was strongly influenced by the concentration of the organic modifier and by the pH of the mobile phase. The best results were achieved at pH 4.5 in presence of 60% of methanol (MeOH). However, longer analysis times were observed in the experiments carried out by nano-LC.

Editorial Emerging Multifunctional Nano structures

International Nuclear Information System (INIS)

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

2009-01-01

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

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

Directory of Open Access Journals (Sweden)

Liberato De Caro

2016-11-01

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

Chemical Imaging of the Cell Membrane by NanoSIMS

International Nuclear Information System (INIS)

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

2010-01-01

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

Synthesis and characterization of nano hydroxyapatite using reverse micro emulsions as nano reactors

International Nuclear Information System (INIS)

Amin, S.; Siddique, T.

2015-01-01

In the present work reverse micro emulsion has been employed as nano reactors to synthesize nano crystalline Hydroxyapatite (HA). Two precursors; calcium and phosphate with different counter ions of each were used for the synthesis of HA at two different temperatures. To maintain the emulsified nano reactor, cyclohexane, TX-100 and 1-butanol including phosphate precursor was the continuous phase while aqueous Ca precursor solution was taken as the dispersed phase. Nano crystalline particles thus produced were evaluated on the basis of synthesis route, counter ions and temperature. It has been shown that emulsified nano reactors control the morphology, particle size and minimize phase transformation of HA. Characterizations of nano powder of HA are carried out using x-ray diffraction (XRD), Fourier transform infra-red spectroscopy (FTIR), and scanning electron microscopy (SEM). HA crystallite size was found to be in the range of 20-25 nm whereas the morphology of nano particles changed from spheres to rods. (author)

Stochastic volatility models and Kelvin waves

Science.gov (United States)

Lipton, Alex; Sepp, Artur

2008-08-01

We use stochastic volatility models to describe the evolution of an asset price, its instantaneous volatility and its realized volatility. In particular, we concentrate on the Stein and Stein model (SSM) (1991) for the stochastic asset volatility and the Heston model (HM) (1993) for the stochastic asset variance. By construction, the volatility is not sign definite in SSM and is non-negative in HM. It is well known that both models produce closed-form expressions for the prices of vanilla option via the Lewis-Lipton formula. However, the numerical pricing of exotic options by means of the finite difference and Monte Carlo methods is much more complex for HM than for SSM. Until now, this complexity was considered to be an acceptable price to pay for ensuring that the asset volatility is non-negative. We argue that having negative stochastic volatility is a psychological rather than financial or mathematical problem, and advocate using SSM rather than HM in most applications. We extend SSM by adding volatility jumps and obtain a closed-form expression for the density of the asset price and its realized volatility. We also show that the current method of choice for solving pricing problems with stochastic volatility (via the affine ansatz for the Fourier-transformed density function) can be traced back to the Kelvin method designed in the 19th century for studying wave motion problems arising in fluid dynamics.

Stochastic volatility models and Kelvin waves

International Nuclear Information System (INIS)

Lipton, Alex; Sepp, Artur

2008-01-01

We use stochastic volatility models to describe the evolution of an asset price, its instantaneous volatility and its realized volatility. In particular, we concentrate on the Stein and Stein model (SSM) (1991) for the stochastic asset volatility and the Heston model (HM) (1993) for the stochastic asset variance. By construction, the volatility is not sign definite in SSM and is non-negative in HM. It is well known that both models produce closed-form expressions for the prices of vanilla option via the Lewis-Lipton formula. However, the numerical pricing of exotic options by means of the finite difference and Monte Carlo methods is much more complex for HM than for SSM. Until now, this complexity was considered to be an acceptable price to pay for ensuring that the asset volatility is non-negative. We argue that having negative stochastic volatility is a psychological rather than financial or mathematical problem, and advocate using SSM rather than HM in most applications. We extend SSM by adding volatility jumps and obtain a closed-form expression for the density of the asset price and its realized volatility. We also show that the current method of choice for solving pricing problems with stochastic volatility (via the affine ansatz for the Fourier-transformed density function) can be traced back to the Kelvin method designed in the 19th century for studying wave motion problems arising in fluid dynamics

Stochastic volatility models and Kelvin waves

Energy Technology Data Exchange (ETDEWEB)

Lipton, Alex [Merrill Lynch, Mlfc Main, 2 King Edward Street, London EC1A 1HQ (United Kingdom); Sepp, Artur [Merrill Lynch, 4 World Financial Center, New York, NY 10080 (United States)], E-mail: Alex_Lipton@ml.com, E-mail: Artur_Sepp@ml.com

2008-08-29

We use stochastic volatility models to describe the evolution of an asset price, its instantaneous volatility and its realized volatility. In particular, we concentrate on the Stein and Stein model (SSM) (1991) for the stochastic asset volatility and the Heston model (HM) (1993) for the stochastic asset variance. By construction, the volatility is not sign definite in SSM and is non-negative in HM. It is well known that both models produce closed-form expressions for the prices of vanilla option via the Lewis-Lipton formula. However, the numerical pricing of exotic options by means of the finite difference and Monte Carlo methods is much more complex for HM than for SSM. Until now, this complexity was considered to be an acceptable price to pay for ensuring that the asset volatility is non-negative. We argue that having negative stochastic volatility is a psychological rather than financial or mathematical problem, and advocate using SSM rather than HM in most applications. We extend SSM by adding volatility jumps and obtain a closed-form expression for the density of the asset price and its realized volatility. We also show that the current method of choice for solving pricing problems with stochastic volatility (via the affine ansatz for the Fourier-transformed density function) can be traced back to the Kelvin method designed in the 19th century for studying wave motion problems arising in fluid dynamics.

Nano devices and sensors

CERN Document Server

Liaw, Shien-Kuei; Chung, Yung-Hui

2016-01-01

This volume on semiconductor devices focuses on such topics as nano-imprinting, lithography, nanowire charge-trapping, thermo-stability in nanowires, nano-electrodes, and voltage and materials used for fabricating and improving electrical characteristics of nano-materials.

Application of emission CT on nano-robot radiation imaging tracing and isotope sign in nano-robot

International Nuclear Information System (INIS)

Wang Xuewu; Cheng Jianping; Kang Kejun

2000-01-01

Nano-technology has been a scientific and technical frontier with major trends foreseen in several disciplines. Nano-robot is the most remarkable imagination of the application of nano-technology. And it should be concerned of tracing technology along with nano-robot. The character of nano-robot is deeply analyzed, the development status of emission CT is integrated, and the application of emission CT on nano-robot radiation imaging tracing is discussed. The isotope sign of nano-robot is especially calculated and analyzed

Fabrication of high-aspect-ratio nano structures using a nano x-ray shadow mask

International Nuclear Information System (INIS)

Kim, Yong Chul; Lee, Seung S

2008-01-01

This paper describes a novel method for the fabrication of high-aspect-ratio nano structures (HAR-nano structures) using a nano x-ray shadow mask and deep x-ray lithography (DXRL). The nano x-ray shadow mask is fabricated by depositing an x-ray absorber layer (Au, 3 µm) onto the back side of a nano shadow mask. The nano shadow mask is produced with nano-sized apertures whose dimensions are reduced to several tens of nanometers by the accumulation of low-stress silicon nitride (Si x N y ) using the LPCVD process on the shadow mask. A shadow mask containing apertures with a size of 1 µm is fabricated on a bulk micromachined Si x N y membrane. The thickness of an absorber layer must be in the range of several tens of micrometers in order to obtain a contrast of more than 100 for the conventional DXRL process at the Pohang Light Source (PLS). However, a 3 µm thick absorber layer can provide a sufficient contrast if the modified DXRL of the central beam-stop method is used, which blocks high-energy x-rays. A nano shadow mask with 30 nm sized apertures is fabricated and a nano x-ray shadow mask with 250 nm sized apertures is fabricated by depositing a 3 µm thick absorber layer on a nano shadow mask with 500 nm sized apertures. HAR-nano structures (circles with a diameter of 420 nm and lines with a width of 274 nm) with aspect ratios of over 10:1 on a 3.2 µm SU-8 are successfully fabricated by using the nano x-ray shadow mask and the central beam-stop method

Electron beam excitation assisted optical microscope with ultra-high resolution.

Science.gov (United States)

Inami, Wataru; Nakajima, Kentaro; Miyakawa, Atsuo; Kawata, Yoshimasa

2010-06-07

We propose electron beam excitation assisted optical microscope, and demonstrated its resolution higher than 50 nm. In the microscope, a light source in a few nanometers size is excited by focused electron beam in a luminescent film. The microscope makes it possible to observe dynamic behavior of living biological specimens in various surroundings, such as air or liquids. Scan speed of the nanometric light source is faster than that in conventional near-field scanning optical microscopes. The microscope enables to observe optical constants such as absorption, refractive index, polarization, and their dynamic behavior on a nanometric scale. The microscope opens new microscopy applications in nano-technology and nano-science.

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

Science.gov (United States)

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

2015-01-01

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

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

Science.gov (United States)

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

2015-11-03

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

Gamma thermometer longevity test: Laguna Verde 2 instruments recent performance

International Nuclear Information System (INIS)

Cuevas V, G.; Avila N, A.; Calleros M, G.

2013-10-01

This paper is informative of the General Electric Hitachi and Global Nuclear Fuel - Americas are collaboration with Comision Federal de Electricidad in a longevity test of thermocouples as power monitoring devices. The test conclusions will serve for final engineering design in detailing the Automated Fixed In-core Probes for calibration of the Local Power Range Monitors (LPRMs) of the Economic Simplified Boiling Water Reactor. This paper introduces the collaboration description and some recent performance evaluation of the thermocouples that are sensitive to gamma radiation and are known generically as Gamma Thermometers (G T). The G Ts in Laguna Verde 2 are radially located inside six instrumentation tubes in the core and consist of seven thermocouples, four are aligned with the LPRM heights and three are axially located between LPRM heights. The Laguna Verde 2 G T test has become the longest test of thermocouples as power monitoring devices in a BWR industry history and confirms their reliability in terms of time-dependent small noise under steady state reactor conditions and good agreement against Traversing In-core Probes power measurements. (Author)

Gamma thermometer longevity test: Laguna Verde 2 instruments recent performance

Energy Technology Data Exchange (ETDEWEB)

Cuevas V, G. [Global Nuclear Fuel, Americas, 3901 Castle Hayne Road, Wilmington, North Carolina (United States); Avila N, A.; Calleros M, G., E-mail: Gabriel.Cuevas-Vivas@gnf.com [Comision Federal de Electricidad, Central Nucleoelectrica Laguna Verda, Carretera Veracruz-Nautla Km 42.5, Alto Lucero, Veracruz (Mexico)

2013-10-15

This paper is informative of the General Electric Hitachi and Global Nuclear Fuel - Americas are collaboration with Comision Federal de Electricidad in a longevity test of thermocouples as power monitoring devices. The test conclusions will serve for final engineering design in detailing the Automated Fixed In-core Probes for calibration of the Local Power Range Monitors (LPRMs) of the Economic Simplified Boiling Water Reactor. This paper introduces the collaboration description and some recent performance evaluation of the thermocouples that are sensitive to gamma radiation and are known generically as Gamma Thermometers (G T). The G Ts in Laguna Verde 2 are radially located inside six instrumentation tubes in the core and consist of seven thermocouples, four are aligned with the LPRM heights and three are axially located between LPRM heights. The Laguna Verde 2 G T test has become the longest test of thermocouples as power monitoring devices in a BWR industry history and confirms their reliability in terms of time-dependent small noise under steady state reactor conditions and good agreement against Traversing In-core Probes power measurements. (Author)

A 6-bit 4 GS/s pseudo-thermometer segmented CMOS DAC

Science.gov (United States)

Yijun, Song; Wenyuan, Li

2014-06-01

A 6-bit 4 GS/s, high-speed and power-efficient DAC for ultra-high-speed transceivers in 60 GHz band millimeter wave technology is presented. A novel pseudo-thermometer architecture is proposed to realize a good compromise between the fast conversion speed and the chip area. Symmetrical and compact floor planning and layout techniques including tree-like routing, cross-quading and common-centroid method are adopted to guarantee the chip is fully functional up to near-Nyquist frequency in a standard 0.18 μm CMOS process. Post simulation results corroborate the feasibility of the designed DAC, which canperform good static and dynamic linearity without calibration. DNL errors and INL errors can be controlled within ±0.28 LSB and ±0.26 LSB, respectively. SFDR at 4 GHz clock frequency for a 1.9 GHz near-Nyquist sinusoidal output signal is 40.83 dB and the power dissipation is less than 37 mW.

A 6-bit 4 GS/s pseudo-thermometer segmented CMOS DAC

International Nuclear Information System (INIS)

Song Yijun; Li Wenyuan

2014-01-01

A 6-bit 4 GS/s, high-speed and power-efficient DAC for ultra-high-speed transceivers in 60 GHz band millimeter wave technology is presented. A novel pseudo-thermometer architecture is proposed to realize a good compromise between the fast conversion speed and the chip area. Symmetrical and compact floor planning and layout techniques including tree-like routing, cross-quading and common-centroid method are adopted to guarantee the chip is fully functional up to near-Nyquist frequency in a standard 0.18 μm CMOS process. Post simulation results corroborate the feasibility of the designed DAC, which canperform good static and dynamic linearity without calibration. DNL errors and INL errors can be controlled within ±0.28 LSB and ±0.26 LSB, respectively. SFDR at 4 GHz clock frequency for a 1.9 GHz near-Nyquist sinusoidal output signal is 40.83 dB and the power dissipation is less than 37 mW. (semiconductor integrated circuits)

Decay of MHD-scale Kelvin-Helmholtz vortices mediated by parasitic electron dynamics

International Nuclear Information System (INIS)

Nakamura, T.K.M.; Hayashi, D.; Fujimoto, M.; Shinohara, I.

2004-01-01

We have simulated nonlinear development of MHD-scale Kelvin-Helmholtz (KH) vortices by a two-dimensional two-fluid system including finite electron inertial effects. In the presence of moderate density jump across a shear layer, in striking contrast to MHD results, MHD KH vortices are found to decay by the time one eddy turnover is completed. The decay is mediated by smaller vortices that appear within the parent vortex and stays effective even when the shear layer width is made larger. It is shown that the smaller vortices are basically of MHD nature while the seeding for these is achieved by the electron inertial effect. Application of the results to the magnetotail boundary layer is discussed

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

International Nuclear Information System (INIS)

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

2012-01-01

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

Development of nano SiO2 incorporated nano zinc phosphate coatings on mild steel

International Nuclear Information System (INIS)

Tamilselvi, M.; Kamaraj, P.; Arthanareeswari, M.; Devikala, S.; Selvi, J. Arockia

2015-01-01

Highlights: • Nano SiO 2 incorporated nano zinc phosphate coating on mild steel was developed. • Coatings showed enhanced corrosion resistance. • The nano SiO 2 is adsorbed on mild steel surface and become nucleation sites. • The nano SiO 2 accelerates the phosphating process. - Abstract: This paper reports the development of nano SiO 2 incorporated nano zinc phosphate coatings on mild steel at low temperature for achieving better corrosion protection. A new formulation of phosphating bath at low temperature with nano SiO 2 was attempted to explore the possibilities of development of nano zinc phosphate coatings on mild steel with improved corrosion resistance. The coatings developed were studied by Scanning Electron Microscopy (SEM), Energy-Dispersive X-ray Spectroscopy (EDX), X-ray Diffraction (XRD), Transmission Electron Microscopy (TEM) and Electrochemical measurements. Significant variation in the coating weight, morphology and corrosion resistance was observed as nano SiO 2 concentrations varied from 0.5–4 g/L. The results showed that, the nano SiO 2 in the phosphating solution changed the initial potential of the interface between mild steel substrate and phosphating solution and reduce the activation energy of the phosphating process, increase the nucleation sites and yielded zinc phosphate coatings of higher coating weight, greater surface coverage and enhanced corrosion resistance. Better corrosion resistance was observed for coatings derived from phosphating bath containing 1.5 g/L nano SiO 2 . The new formulation reported in the present study was free from Ni or Mn salts and had very low concentration of sodium nitrite (0.4 g/L) as accelerator

To be nano or not to be nano?

Science.gov (United States)

Joachim, Christian

2005-02-01

Nanomaterials, nanostructures, nanostructured materials, nanoimprint, nanobiotechnology, nanophysics, nanochemistry, radical nanotechnology, nanosciences, nanooptics, nanoelectronics, nanorobotics, nanosoldiers, nanomedecine, nanoeconomy, nanobusiness, nanolawyer, nanoethics to name a few of the nanos. We need a clear definition of all these burgeoning fields for the sake of the grant attribution, for the sake of research program definition, and to avoid everyone being lost in so many nanos.

SQUIDs in thermal detectors of weakly interacting particles

International Nuclear Information System (INIS)

Trofimov, V.N.

1991-01-01

The application of four different types of SQUID-assisted thermometers for cryogenic thermal detectors of weakly interacting particles is analyzed with two of them for the first time. The classic resistive thermometer is considered as well for the comparison. Original results of testing the detector with working temperature of 1K and thermocouple thermometer with SQUID are given. The conclusion is made that temperature resolution of 10 -10 kHz -1/2 or energy sensitivity of 1-10 eV per 1 kg of detector mass can be achieved when using the SQUID-assisted thermometers. 12 refs.; 7 figs.; 1 tab

Diffusion at the Earth magnetopause: enhancement by Kelvin-Helmholtz instability

Directory of Open Access Journals (Sweden)

R. Smets

2007-02-01

Full Text Available Using hybrid simulations, we examine how particles can diffuse across the Earth's magnetopause because of finite Larmor radius effects. We focus on tangential discontinuities and consider a reversal of the magnetic field that closely models the magnetopause under southward interplanetary magnetic field. When the Larmor radius is on the order of the field reversal thickness, we show that particles can cross the discontinuity. We also show that with a realistic initial shear flow, a Kelvin-Helmholtz instability develops that increases the efficiency of the crossing process. We investigate the distribution functions of the transmitted ions and demonstrate that they are structured according to a D-shape. It accordingly appears that magnetic reconnection at the magnetopause is not the only process that leads to such specific distribution functions. A simple analytical model that describes the built-up of these functions is proposed.

Vector electric field measurement via position-modulated Kelvin probe force microscopy

Science.gov (United States)

Dwyer, Ryan P.; Smieska, Louisa M.; Tirmzi, Ali Moeed; Marohn, John A.

2017-10-01

High-quality spatially resolved measurements of electric fields are critical to understanding charge injection, charge transport, and charge trapping in semiconducting materials. Here, we report a variation of frequency-modulated Kelvin probe force microscopy that enables spatially resolved measurements of the electric field. We measure electric field components along multiple directions simultaneously by employing position modulation and lock-in detection in addition to numeric differentiation of the surface potential. We demonstrate the technique by recording linescans of the in-plane electric field vector in the vicinity of a patch of trapped charge in a 2,7-diphenyl[1]benzothieno[3,2-b][1]benzothiophene (DPh-BTBT) organic field-effect transistor. This technique is simple to implement and should be especially useful for studying electric fields in spatially inhomogeneous samples like organic transistors and photovoltaic blends.

Measuring minority-carrier diffusion length using a Kelvin probe force microscope

International Nuclear Information System (INIS)

Shikler, R.; Fried, N.; Meoded, T.; Rosenwaks, Y.

2000-01-01

A method based on Kelvin probe force microscopy for measuring minority-carrier diffusion length in semiconductors is described. The method is based on measuring the surface photovoltage between the tip of an atomic force microscope and the surface of an illuminated semiconductor junction. The photogenerated carriers diffuse to the junction and change the contact potential difference between the tip and the sample, as a function of the distance from the junction. The diffusion length L is then obtained by fitting the measured contact potential difference using the minority-carrier continuity equation. The method was applied to measurements of electron diffusion length in GaP pn and Schottky junctions. The measured diffusion length was found to be ∼2 μm, in good agreement with electron beam induced current measurements

The nano-materials, at the heart of the nano galaxy; Les nano-materiaux, au coeur de la galaxie nano

Energy Technology Data Exchange (ETDEWEB)

Le Marois, G. [Direction Generale de l' Industrie, des Technologies de l' Information et des Postes, 75 - Paris (France); Carlac, D. [Societe Developpement et Conseil, 51 - Reims (France)

2004-02-01

The researches on nano-materials are continuously increasing in most of industrialized countries. Between 1998 and 2003, the corresponding investment has been multiplied by six in Europe, eight in Usa and in Japan, to reach 3 milliards of euros in the world. Based on the nano-technologies development, these materials would represent the main part of the market at short and middle dated. Many examples of utilization are presented. (A.L.B.)

Aluminum Templates of Different Sizes with Micro-, Nano- and Micro/Nano-Structures for Cell Culture

Directory of Open Access Journals (Sweden)

Ming-Liang Yen

2017-10-01

Full Text Available This study investigates the results of cell cultures on aluminum (Al templates with flat-structures, micro-structures, nano-structures and micro/nano-structures. An Al template with flat-structure was obtained by electrolytic polishing; an Al template with micro-structure was obtained by micro-powder blasting; an Al template with nano-structure was obtained by aluminum anodization; and an Al template with micro/nano-structure was obtained by micro-powder blasting and then anodization. Osteoblast-like cells were cultured on aluminum templates with various structures. The microculture tetrazolium test assay was utilized to assess the adhesion, elongation, and proliferation behaviors of cultured osteoblast-like cells on aluminum templates with flat-structures, micro-structures, nano-structures, and micro/nano-structures. The results showed that the surface characterization of micro/nano-structure of aluminum templates had superhydrophilic property, and these also revealed that an aluminum template with micro/nano-structure could provide the most suitable growth situation for cell culture.

A comparative study on accuracy of liquid crystal forehead, digital electronic axillary, infrared tympanic with glass-mercury rectal thermometer in infants and young children.

Science.gov (United States)

Kongpanichkul, A; Bunjongpak, S

2000-09-01

This study was carried out to assess the accuracy of three devices namely, liquid crystal forehead, digital electronic axillary and infrared tympanic thermometer, using a glass-mercury rectal thermometer as the control. The subjects were two hundred children aged 0-48 months. The mean rectal temperature was 38.0 +/- 0.91 degrees C; forehead, 37.83 +/- 0.94 degrees C; tympanic, 37.77 +/- 0.95 degrees C, and axillary, 37.71 +/- 0.86 degrees C. Compared to the rectal temperature, all values were significantly lower (p < 0.05). Forehead, tympanic and axillary temperature differed from rectal temperature by at least 0.5 degrees C in 33.33 per cent, 23.5 per cent and 31.5 per cent of subjects, and at least 1 degrees C in 22 per cent, 1 per cent and 6 per cent of subjects respectively. Accuracy in detection of fever was 79 per cent for forehead, 85.5 per cent for tympanic and 84 per cent for axillary thermometry. Sensitivity of the three devices was 67-83 per cent in detection of fever and 64-77 per cent in detection of high fever. Tympanic thermometry had the best performance while forehead thermometry had the poorest. After using revised diagnostic threshold temperature by ROC curves, sensitivity of each device improved but accuracy was nearly the same. It is concluded that the three devices are not suitable as a substitute for a glass-mercury rectal thermometer in assessment of fever in infants and young children.

Nanoscale Resolution 3D Printing with Pin-Modified Electrified Inkjets for Tailorable Nano/Macrohybrid Constructs for Tissue Engineering.

Science.gov (United States)

Kim, Jeong In; Kim, Cheol Sang

2018-04-18

Cells respond to their microenvironment, which is of a size comparable to that of the cells. The macroscale features of three-dimensional (3D) printing struts typically result in whole cell contact guidance (CCG). In contrast, at the nanoscale, where features are of a size similar to that of receptors of cells, the response of cells is more complex. The cell-nanotopography interaction involves nanoscale adhesion localized structures, which include cell adhesion-related particles that change in response to the clustering of integrin. For this reason, it is necessary to develop a technique for manufacturing tailorable nano/macrohybrid constructs capable of freely controlling the cellular activity. In this study, a hierarchical 3D nano- to microscale hybrid structure was fabricated by combinational processing of 3D printing and electrified inkjet spinning via pin motions. This method overcomes the disadvantages of conventional 3D printing, providing a novel combinatory technique for the fabrication of 3D hybrid constructs with excellent cell proliferation. Through a pin-modified electrified inkjet spinning, we have successfully fabricated customizable nano-/microscale hybrid constructs in a fibrous or mesh form, which can control the cell fate. We have conducted this study of cell-topography interactions from the fabrication approach to accelerate the development of next-generation 3D scaffolds.

Dealing with the size-of-source effect in the calibration of direct-reading radiation thermometer

Energy Technology Data Exchange (ETDEWEB)

Saunders, P. [Measurement Standards Laboratory of New Zealand, PO Box 31-310, Lower Hutt 5040 (New Zealand)

2013-09-11

The majority of general-purpose low-temperature handheld radiation thermometers are severely affected by the size-of-source effect (SSE). Calibration of these instruments is pointless unless the SSE is accounted for in the calibration process. Traditional SSE measurement techniques, however, are costly and time consuming, and because the instruments are direct-reading in temperature, traditional SSE results are not easily interpretable, particularly by the general user. This paper describes a simplified method for measuring the SSE, suitable for second-tier calibration laboratories and requiring no additional equipment, and proposes a means of reporting SSE results on a calibration certificate that should be easily understood by the non-specialist user.

Functional Nano fibers: Production and Applications

International Nuclear Information System (INIS)

Khatri, Z.; Kim, I.S.; Kim, S.H.

2016-01-01

Nano fibers are lighter material with higher surface area in comparison to polymeric film. The ease of producing functional nano fiber is another advantage over many nano materials. Functional nano fiber in particular has attained a greater interest in recent years. The applications of functional nano fibers are increasing in various technical fields such as water filter membranes, tissue engineering, biosensors, drug delivery systems, wound dressings, catalysis, antibacterial. This special issue is comprised of well-selective articles that discuss production of functional nano fibers their applications in different emerging fields. M. Zhang et al. have presented exciting work on drug delivery using nano fibers. They used collagen that was extracted from abandoned Rana chensinensis skin in northeastern China via an acid enzymatic extraction method. They demonstrated two different nano fiber-vancomycin (VCM) systems, that is, VCM blended nano fibers and core-shell nano fibers with VCM in the core, and both systems sustained control release for a period of 80 hours. Another work was presented by R. Takai et al. on blood purification using composite nano fibers. About 10% of the population worldwide is affected by chronic kidney disease (CKD). The authors developed nano fiber meshes zeolite-polymer composite nano fibers for efficient adsorption of creatinine, which is a simpler and more accessible method for hemodialysis (HD) patients.

Effects of incorporation of nano-fluorapatite or nano-fluorohydroxyapatite on a resin-modified glass ionomer cement.

Science.gov (United States)

Lin, Jun; Zhu, Jiajun; Gu, Xiaoxia; Wen, Wenjian; Li, Qingshan; Fischer-Brandies, Helge; Wang, Huiming; Mehl, Christian

2011-03-01

This study aimed to investigate the fluoride release properties and the effect on bond strength of two experimental adhesive cements. Synthesized particles of nano-fluorapatite (nano-FA) or nano-fluorohydroxyapatite (nano-FHA) were incorporated into a resin-modified glass ionomer cement (Fuji Ortho LC) and characterized using X-ray diffraction and scanning electron microscopy. Blocks with six different concentrations of nano-FA or nano-FHA were manufactured and their fluoride release properties evaluated by ultraviolet spectrophotometry. The unaltered glass ionomer cement Fuji Ortho LC (GC, control) and the two experimental cements with the highest fluoride release capacities (nano-FA+Fuji Ortho LC (GFA) and nano-FHA+Fuji Ortho LC (GFHA)) were used to bond composite blocks and orthodontic brackets to human enamel. After 24 h water storage all specimens were debonded, measuring the micro-tensile bond strength (μTBS) and the shear bond strength (SBS), respectively. The optimal concentration of added nano-FA and nano-FHA for maximum fluoride release was 25 wt.%, which nearly tripled fluoride release after 70 days compared with the control group. GC exhibited a significantly higher SBS than GFHA/GFA, with GFHA and GFA not differing significantly (P>0.05). The μTBS of GC and GFA were significantly higher than that of GFHA (P≤0.05). The results seem to indicate that the fluoride release properties of Fuji Ortho LC are improved by incorporating nano-FA or nano-FHA, simultaneously maintaining a clinically sufficient bond strength when nano-FA was added. Copyright © 2010 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Selective and lithography-independent fabrication of 20 nm nano-gap electrodes and nano-channels for nanoelectrofluidics applications

International Nuclear Information System (INIS)

Zhang, J Y; Wang, X F; Wang, X D; Fan, Z C; Li, Y; Ji, An; Yang, F H

2010-01-01

A new method has been developed to selectively fabricate nano-gap electrodes and nano-channels by conventional lithography. Based on a sacrificial spacer process, we have successfully obtained sub-100-nm nano-gap electrodes and nano-channels and further reduced the dimensions to 20 nm by shrinking the sacrificial spacer size. Our method shows good selectivity between nano-gap electrodes and nano-channels due to different sacrificial spacer etch conditions. There is no length limit for the nano-gap electrode and the nano-channel. The method reported in this paper also allows for wafer scale fabrication, high throughput, low cost, and good compatibility with modern semiconductor technology.

Numerical study of the lateral resolution in electrostatic force microscopy for dielectric samples

International Nuclear Information System (INIS)

Riedel, C; AlegrIa, A; Colmenero, J; Schwartz, G A; Saenz, J J

2011-01-01

We present a study of the lateral resolution in electrostatic force microscopy for dielectric samples in both force and gradient modes. Whereas previous studies have reported expressions for metallic surfaces having potential heterogeneities (Kelvin probe force microscopy), in this work we take into account the presence of a dielectric medium. We introduce a definition of the lateral resolution based on the force due to a test particle being either a point charge or a polarizable particle on the dielectric surface. The behaviour has been studied over a wide range of typical experimental parameters: tip-sample distance (1-20) nm, sample thickness (0-5) μm and dielectric constant (1-20), using the numerical simulation of the equivalent charge method. For potential heterogeneities on metallic surfaces expressions are in agreement with the bibliography. The lateral resolution of samples having a dielectric constant of more than 10 tends to metallic behaviour. We found a characteristic thickness of 100 nm, above which the lateral resolution measured on the dielectric surface is close to that of an infinite medium. As previously reported, the lateral resolution is better in the gradient mode than in the force mode. Finally, we showed that for the same experimental conditions, the lateral resolution is better for a polarizable particle than for a charge, i.e. dielectric heterogeneities should always look 'sharper' (better resolved) than inhomogeneous charge distributions. This fact should be taken into account when interpreting images of heterogeneous samples.

Numerical study of the lateral resolution in electrostatic force microscopy for dielectric samples

Energy Technology Data Exchange (ETDEWEB)

Riedel, C; AlegrIa, A; Colmenero, J [Departamento de Fisica de Materiales UPV/EHU, Facultad de Quimica, Apartado 1072, 20080 San Sebastian (Spain); Schwartz, G A [Centro de Fisica de Materiales CSIC-UPV/EHU, Paseo Manuel de Lardizabal 5, 20018 San Sebastian (Spain); Saenz, J J, E-mail: riedel@ies.univ-montp2.fr [Donostia International Physics Center, Paseo Manuel de Lardizabal 4, 20018 San Sebastian (Spain)

2011-07-15

We present a study of the lateral resolution in electrostatic force microscopy for dielectric samples in both force and gradient modes. Whereas previous studies have reported expressions for metallic surfaces having potential heterogeneities (Kelvin probe force microscopy), in this work we take into account the presence of a dielectric medium. We introduce a definition of the lateral resolution based on the force due to a test particle being either a point charge or a polarizable particle on the dielectric surface. The behaviour has been studied over a wide range of typical experimental parameters: tip-sample distance (1-20) nm, sample thickness (0-5) {mu}m and dielectric constant (1-20), using the numerical simulation of the equivalent charge method. For potential heterogeneities on metallic surfaces expressions are in agreement with the bibliography. The lateral resolution of samples having a dielectric constant of more than 10 tends to metallic behaviour. We found a characteristic thickness of 100 nm, above which the lateral resolution measured on the dielectric surface is close to that of an infinite medium. As previously reported, the lateral resolution is better in the gradient mode than in the force mode. Finally, we showed that for the same experimental conditions, the lateral resolution is better for a polarizable particle than for a charge, i.e. dielectric heterogeneities should always look 'sharper' (better resolved) than inhomogeneous charge distributions. This fact should be taken into account when interpreting images of heterogeneous samples.

Magnetohydrodynamic Kelvin-Helmholtz instabilities in astrophysics. 4. Single shear layer in MHD flows

Energy Technology Data Exchange (ETDEWEB)

Ferrari, A [Consiglio Nazionale delle Ricerche, Turin (Italy). Lab. di Cosmo-Geofisica; Turin Univ. (Italy). Ist. di Fisica Generale); Trussoni, E [Consiglio Nazionale delle Ricerche, Turin (Italy). Lab. di Cosmo-Geofisica; Max-Planck-Institut fuer Physik und Astrophysik, Garching (Germany, F.R.). Inst. fuer Extraterrestrische Physik)

1983-11-01

In this further paper on the physics of Kelvin-Helmholtz instabilities the case in which the fluids in relative motion are magnetized and separated by a shear layer is investigated. The present study points out, with respect to previous treatments, that different velocity profiles affect perturbations of short wavelength (as compared to the scale of the shear). Another new result is in the destabilizing effect, even in the subsonic regime, of the magnetic field on modes neutrally stable in the vortex sheet approximation. Such a behaviour is analogous to that found in the fluid case for Mach numbers >approx. = to 2. Possible astrophysical implications are also discussed.

Nano materials for Energy and Environmental Applications

International Nuclear Information System (INIS)

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

2015-01-01

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

Visualization of the internal structure of Didymosphenia geminata frustules using nano X-ray tomography.

Science.gov (United States)

Zgłobicka, Izabela; Li, Qiong; Gluch, Jürgen; Płocińska, Magdalena; Noga, Teresa; Dobosz, Romuald; Szoszkiewicz, Robert; Witkowski, Andrzej; Zschech, Ehrenfried; Kurzydłowski, Krzysztof J

2017-08-22

For the first time, the three-dimensional (3D) internal structure of naturally produced Didymosphenia geminata frustules were nondestructively visualized at sub-100 nm resolution. The well-optimized hierarchical structures of these natural organisms provide insight that is needed to design novel, environmentally friendly functional materials. Diatoms, which are widely distributed in freshwater, seawater and wet soils, are well known for their intricate, siliceous cell walls called 'frustules'. Each type of diatom has a specific morphology with various pores, ribs, minute spines, marginal ridges and elevations. In this paper, the visualization is performed using nondestructive nano X-ray computed tomography (nano-XCT). Arbitrary cross-sections through the frustules, which can be extracted from the nano-XCT 3D data set for each direction, are validated via the destructive focused ion beam (FIB) cross-sectioning of regions of interest (ROIs) and subsequent observation by scanning electron microscopy (SEM). These 3D data are essential for understanding the functionality and potential applications of diatom cells.

Comparison of Two Grid Refinement Approaches for High Resolution Regional Climate Modeling: MPAS vs WRF

Science.gov (United States)

Leung, L.; Hagos, S. M.; Rauscher, S.; Ringler, T.

2012-12-01

This study compares two grid refinement approaches using global variable resolution model and nesting for high-resolution regional climate modeling. The global variable resolution model, Model for Prediction Across Scales (MPAS), and the limited area model, Weather Research and Forecasting (WRF) model, are compared in an idealized aqua-planet context with a focus on the spatial and temporal characteristics of tropical precipitation simulated by the models using the same physics package from the Community Atmosphere Model (CAM4). For MPAS, simulations have been performed with a quasi-uniform resolution global domain at coarse (1 degree) and high (0.25 degree) resolution, and a variable resolution domain with a high-resolution region at 0.25 degree configured inside a coarse resolution global domain at 1 degree resolution. Similarly, WRF has been configured to run on a coarse (1 degree) and high (0.25 degree) resolution tropical channel domain as well as a nested domain with a high-resolution region at 0.25 degree nested two-way inside the coarse resolution (1 degree) tropical channel. The variable resolution or nested simulations are compared against the high-resolution simulations that serve as virtual reality. Both MPAS and WRF simulate 20-day Kelvin waves propagating through the high-resolution domains fairly unaffected by the change in resolution. In addition, both models respond to increased resolution with enhanced precipitation. Grid refinement induces zonal asymmetry in precipitation (heating), accompanied by zonal anomalous Walker like circulations and standing Rossby wave signals. However, there are important differences between the anomalous patterns in MPAS and WRF due to differences in the grid refinement approaches and sensitivity of model physics to grid resolution. This study highlights the need for "scale aware" parameterizations in variable resolution and nested regional models.

Si Nano wires Produced by Very High Frequency Plasma Enhanced Chemical Vapor Deposition (PECVD) via VLS Mechanism

International Nuclear Information System (INIS)

Yussof Wahab; Yussof Wahab; Habib Hamidinezhad; Habib Hamidinezhad

2013-01-01

Silicon nano wires (SiNWs) with diameter of about a few nanometers and length of 3 μm on silicon wafers were synthesized by very high frequency plasma enhanced chemical vapor deposition. Scanning electron microscopy (SEM) observations showed that the silicon nano wires were grown randomly and energy-dispersive X-ray spectroscopy analysis indicates that the nano wires have the composition of Si, Au and O elements. The SiNWs were characterized by high resolution transmission electron microscopy (HRTEM) and Raman spectroscopy. SEM micrographs displayed SiNWs that are needle-like with a diameter ranged from 30 nm at the top to 100 nm at the bottom of the wire and have length a few of micrometers. In addition, HRTEM showed that SiNWs consist of crystalline silicon core and amorphous silica layer. (author)

3D positioning scheme exploiting nano-scale IR-UWB orthogonal pulses

Directory of Open Access Journals (Sweden)

Kim Nammoon

2011-01-01

Full Text Available Abstract In these days, the development of positioning technology for realizing ubiquitous environments has become one of the most important issues. The Global Positioning System (GPS is a well-known positioning scheme, but it is not suitable for positioning in in-door/building environments because it is difficult to maintain line-of-sight condition between satellites and a GPS receiver. To such problem, various positioning methods such as RFID, WLAN, ZigBee, and Bluetooth have been developed for indoor positioning scheme. However, the majority of positioning schemes are focused on the two-dimension positioning even though three-dimension (3D positioning information is more useful especially in indoor applications, such as smart space, U-health service, context aware service, etc. In this paper, a 3D positioning system based on mutually orthogonal nano-scale impulse radio ultra-wideband (IR-UWB signals and cross array antenna is proposed. The proposed scheme uses nano-scale IR-UWB signals providing fine time resolution and high-resolution multiple signal specification algorithm for the time-of-arrival and the angle-of-arrival estimation. The performance is evaluated over various IEEE 802.15.4a channel models, and simulation results show the effectiveness of proposed scheme.

Nano

DEFF Research Database (Denmark)

Nørgaard, Bent; Engel, Lars Romann

2007-01-01

Gennem de sidste par år har et lille ord med et meget stort potentiale gentagende trængt sig på i den offentlige bevidsthed, det er ordet "nano". Nanovidenskab og nanoteknologi er lige nu to af de "hotteste" forskningsområder og betragtes af mange som porten til en helt ny verden af muligheder....... Muligheder, vi endnu ikke kender konsekvenserne af. Center for Kunst og Videnskabs forestilling NANO giver dig chancen for at blive bekendt med verdens mindste byggesten og idégrundlaget for nanoforskningen. Vi har skabt et rum, som på mange måder minder om et laboratorium. Rummet er forsynet med storskærme......, kolber, væsker og nanopartikler. Her vil du f.eks. opleve, hvordan forskere tilfører guld helt nye egenskaber. Forestillingen veksler mellem kemiske arbejdsdemonstrationer, stemningsskabende musik og livlig debat på storskærme mellem eksperter. NANO opfordrer publikum til at tage stilling til forskningen...

The therapeutic effect of nano-encapsulated and nano-emulsion forms of carvacrol on experimental liver fibrosis.

Science.gov (United States)

Hussein, Jihan; El-Banna, Mona; Mahmoud, Khaled F; Morsy, Safaa; Abdel Latif, Yasmin; Medhat, Dalia; Refaat, Eman; Farrag, Abdel Razik; El-Daly, Sherien M

2017-06-01

The present study aimed to compare the therapeutic efficiency of nano-encapsulated and nano-emulsion carvacrol administration on liver injury in thioacetamide (TAA) treated rats. To fulfill our target, we used sixty male albino rats classified into six groups as follow: control, nano-encapsulated carvacrol, nano-emulsion carvacrol, thioacetamide, treated nano-encapsulated carvacrol and treated nano-emulsion carvacrol groups. Blood samples were collected from all groups and the separated serum was used for analysis of the following biochemical parameters; aspartate aminotransferase (AST), alanine aminotransferase (ALT), S100 B protein, alpha fetoprotein (AFP) and caspase-3. The levels of malondialdehyde (MDA), reduced glutathione (GSH), nitric oxide (NO), monocyte chemoattractant protein-1(MCP-1) and hydroxyproline content were all evaluated in liver tissue homogenate. Histopathological examinations for liver tissues were also performed. Thioacetamide induced hepatic damage in rats as revealed by the significant increase in the levels of serum ALT, AST and produced oxidative stress as displayed by the significant elevation in the levels of hepatic MDA and NO concomitant with a significant decrease in GSH. In addition, thioacetamide significantly increased serum S100B protein, alpha fetoprotein and caspase-3 along with hepatic MCP-1 and hydroxyproline; these results were confirmed by the histopathological investigation. In contrast, nano-encapsulated and nano-emulsion carvacrol were able to ameliorate these negative changes in the thioacetamide injected rats. However, the effect of the nano-encapsulated form of carvacrol was more prominent than the nano-emulsion form. Nano-encapsulated and nano-emulsion carvacrol can ameliorate thioacetamide induced liver injury. These results could be attributed to the potential anti-inflammatory, antioxidant, and anti-apoptotic activities of carvacrol in addition to the effectiveness of the encapsulation technique that can protect

Nano medicine in Action: An Overview of Cancer Nano medicine on the Market and in Clinical Trials

International Nuclear Information System (INIS)

Wang, R.; Billone, P.S.; Mullett, W.M.

2013-01-01

Nano medicine, defined as the application of nano technology in the medical field, has the potential to significantly change the course of diagnostics and treatment of life-threatening diseases, such as cancer. In comparison with traditional cancer diagnostics and therapy, cancer nano medicine provides sensitive cancer detection and/or enhances treatment efficacy with significantly minimized adverse effects associated with standard therapeutics. Cancer nano medicine has been increasingly applied in areas including nano drug delivery systems, nano pharmaceuticals, and nano analytical contrast reagents in laboratory and animal model research. In recent years, the successful introduction of several novel nano medicine products into clinical trials and even onto the commercial market has shown successful outcomes of fundamental research into clinics. This paper is intended to examine several nano medicines for cancer therapeutics and/or diagnostics-related applications, to analyze the trend of nano medicine development, future opportunities, and challenges of this fast-growing area.

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

International Nuclear Information System (INIS)

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

2011-01-01

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

'Applications of stable isotopes in life sciences'. Lead and strontium stable isotope measurements by using a high lateral resolution secondary ion mass spectrometer (NanoSIMS)

International Nuclear Information System (INIS)

Sano, Yuji

2008-01-01

The method of Pb and Sr isotope measurements at about 5 μm resolution was developed by using a high lateral resolution secondary ion mass spectrometer (NanoSIMS NS50). Since the both elements have radiogenic nuclides such as 206 Pb, 207 Pb, and 87 Sr, natural variations of isotopic ratios are large. It is possible to detect a meaningful variation in a terrestrial sample, even though the experimental error is relatively large. In the case of monazite U-Pb dating, a 4 nA O - primary beam was used to sputter the sample and secondary positive ions were extracted for mass analysis using a Mattauch-Herzog geometry. The multi-collector system was modified to detect 140 Ce + , 204 Pb + , 206 Pb + , 238 U 16 O + , and 238 U 16 O 2 + ions simultaneously. Based on the monazite standard from North-Central Madagascar, we have determined the 206 Pb/ 238 U ratios of samples. 207 Pb/ 206 Pb ratios were measured by a magnet scanning with a single collector mode. 44 monazite grains extracted from a sedimentary rock in Taiwan were analyzed. Observed ages were consistent with the U-Th-Pb chemical ages by EPMA. Then NanoSIMS has been used to measure 87 Sr/ 86 Sr ratios in natural calcium carbonate samples. Multi-collector system was adjusted to detect 43 Ca + , 80 Ca 2 + , 86 Sr + , and 87 Sr + ions at the same time. Magnetic field was scanning for the EM no.4 counter to detect 85 Rb + , 86 Sr + and 87 Sr + , while the EM no.4b can measure 86 Sr + , 87 Sr + , and 88 Sr + , respectively. Repeated analyses of a coral skeleton standard (JCp-1) show that 87 Sr/ 86 Sr ratio agrees well with the seawater signature, after the series of corrections such as Ca dimer, 87 Rb, and a mass bias estimated by 88 Sr/ 86 Sr ratio. The method is applied to an otolith from ayu (Pleco-glossus altivelis altivelis) collected from the Yodo river, Japan. The spatial variation of 87 Sr/ 86 Sr ratios was consistent with amphidromous migration of the fish, namely, born in the lake and grown in the coastal sea

Magnetohydrodynamic Kelvin-Helmholtz instabilities in astrophysics. 1. Relativistic flows-plane boundary layer in vortex sheet approximation

Energy Technology Data Exchange (ETDEWEB)

Ferrari, A; Trussoni, E; Zaninetti, L [Consiglio Nazionale delle Ricerche, Turin (Italy). Lab. di Cosmo-Geofisica; Turin Univ. (Italy). Ist. di Fisica)

1980-11-01

In this paper some unsolved problems of the linear MHD Kelvin-Helmholtz instability are re-examined, starting from the analysis of relativistic (and non-relativistic) flows in the approximation of a plane vortex sheet, for the contact layer between the fluids in relative motion. Results are discussed for a range of physical parameters in specific connection with application to models of jets in extragalactic radio sources. Other physical aspects of the instability will be considered in forthcoming papers.

Work function of few layer graphene covered nickel thin films measured with Kelvin probe force microscopy

Energy Technology Data Exchange (ETDEWEB)

Eren, B. [Department of Physics, University of Basel, Klingelbergstrasse 82, CH-4056 Basel (Switzerland); Material Sciences Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720 (United States); Gysin, U.; Marot, L., E-mail: Laurent.marot@unibas.ch; Glatzel, Th.; Steiner, R.; Meyer, E. [Department of Physics, University of Basel, Klingelbergstrasse 82, CH-4056 Basel (Switzerland)

2016-01-25

Few layer graphene and graphite are simultaneously grown on a ∼100 nm thick polycrystalline nickel film. The work function of few layer graphene/Ni is found to be 4.15 eV with a variation of 50 meV by local measurements with Kelvin probe force microscopy. This value is lower than the work function of free standing graphene due to peculiar electronic structure resulting from metal 3d-carbon 2p(π) hybridization.

From cosmic chirality to protein structure: Lord Kelvin's legacy.

Science.gov (United States)

Barron, Laurence D

2012-11-01

A selection of my work on chirality is sketched in two distinct parts of this lecture. Symmetry and Chirality explains how the discrete symmetries of parity P, time reversal T, and charge conjugation C may be used to characterize the properties of chiral systems. The concepts of true chirality (time-invariant enantiomorphism) and false chirality (time-noninvariant enantiomorphism) that emerge provide an extension of Lord Kelvin's original definition of chirality to situations where motion is an essential ingredient thereby clarifying, inter alia, the nature of physical influences able to induce absolute enantioselection. Consideration of symmetry violations reveals that strict enantiomers (exactly degenerate) are interconverted by the combined CP operation. Raman optical activity surveys work, from first observation to current applications, on a new chiroptical spectroscopy that measures vibrational optical activity via Raman scattering of circularly polarized light. Raman optical activity provides incisive information ranging from absolute configuration and complete solution structure of smaller chiral molecules and oligomers to protein and nucleic acid structure of intact viruses. Copyright © 2012 Wiley Periodicals, Inc., A Wiley Company.

Single-cell intracellular nano-pH probes†

Science.gov (United States)

Özel, Rıfat Emrah; Lohith, Akshar; Mak, Wai Han; Pourmand, Nader

2016-01-01

Within a large clonal population, such as cancerous tumor entities, cells are not identical, and the differences between intracellular pH levels of individual cells may be important indicators of heterogeneity that could be relevant in clinical practice, especially in personalized medicine. Therefore, the detection of the intracellular pH at the single-cell level is of great importance to identify and study outlier cells. However, quantitative and real-time measurements of the intracellular pH of individual cells within a cell population is challenging with existing technologies, and there is a need to engineer new methodologies. In this paper, we discuss the use of nanopipette technology to overcome the limitations of intracellular pH measurements at the single-cell level. We have developed a nano-pH probe through physisorption of chitosan onto hydroxylated quartz nanopipettes with extremely small pore sizes (~100 nm). The dynamic pH range of the nano-pH probe was from 2.6 to 10.7 with a sensitivity of 0.09 units. We have performed single-cell intracellular pH measurements using non-cancerous and cancerous cell lines, including human fibroblasts, HeLa, MDA-MB-231 and MCF-7, with the pH nanoprobe. We have further demonstrated the real-time continuous single-cell pH measurement capability of the sensor, showing the cellular pH response to pharmaceutical manipulations. These findings suggest that the chitosan-functionalized nanopore is a powerful nano-tool for pH sensing at the single-cell level with high temporal and spatial resolution. PMID:27708772

Single-cell intracellular nano-pH probes.

Science.gov (United States)

Özel, Rıfat Emrah; Lohith, Akshar; Mak, Wai Han; Pourmand, Nader

2015-01-01

Within a large clonal population, such as cancerous tumor entities, cells are not identical, and the differences between intracellular pH levels of individual cells may be important indicators of heterogeneity that could be relevant in clinical practice, especially in personalized medicine. Therefore, the detection of the intracellular pH at the single-cell level is of great importance to identify and study outlier cells. However, quantitative and real-time measurements of the intracellular pH of individual cells within a cell population is challenging with existing technologies, and there is a need to engineer new methodologies. In this paper, we discuss the use of nanopipette technology to overcome the limitations of intracellular pH measurements at the single-cell level. We have developed a nano-pH probe through physisorption of chitosan onto hydroxylated quartz nanopipettes with extremely small pore sizes (~100 nm). The dynamic pH range of the nano-pH probe was from 2.6 to 10.7 with a sensitivity of 0.09 units. We have performed single-cell intracellular pH measurements using non-cancerous and cancerous cell lines, including human fibroblasts, HeLa, MDA-MB-231 and MCF-7, with the pH nanoprobe. We have further demonstrated the real-time continuous single-cell pH measurement capability of the sensor, showing the cellular pH response to pharmaceutical manipulations. These findings suggest that the chitosan-functionalized nanopore is a powerful nano-tool for pH sensing at the single-cell level with high temporal and spatial resolution.

Magnetic Criticality Enhanced Hybrid Nanodiamond Thermometer under Ambient Conditions

Science.gov (United States)

Wang, Ning; Liu, Gang-Qin; Leong, Weng-Hang; Zeng, Hualing; Feng, Xi; Li, Si-Hong; Dolde, Florian; Fedder, Helmut; Wrachtrup, Jörg; Cui, Xiao-Dong; Yang, Sen; Li, Quan; Liu, Ren-Bao

2018-01-01

Nitrogen-vacancy (NV) centers in diamond are attractive as quantum sensors owing to their superb coherence under ambient conditions. However, the NV center spin resonances are relatively insensitive to some important parameters such as temperature and pressure. Here we design and experimentally demonstrate a hybrid nanothermometer composed of NV centers and a magnetic nanoparticle (MNP), in which the temperature sensitivity is enhanced by the critical magnetization of the MNP near the ferromagnetic-paramagnetic transition temperature. The temperature susceptibility of the NV center spin resonance reaches 14 MHz /K , nearly 200 times larger than that of bare NV centers. The sensitivity of a hybrid nanothermometer composed of a Cu1 -xNix MNP and a nanodiamond is measured to be 11 mK /√{Hz } under ambient conditions. The working range of the hybrid thermometer can be designed from cryogenic temperature to about 600 K by tuning the chemical composition of the Cu1 -xNix MNP. We demonstrate in situ detection of the magnetic phase transition of a single magnetic nanoparticle using the hybrid nanothermometer. This hybrid nanothermometer provides a novel approach to studying a broad range of thermal processes at nanoscales such as nanoplasmonics, heat-stimulated subcellular processes, and thermodynamics of nanosystems.

Magnetic Criticality Enhanced Hybrid Nanodiamond Thermometer under Ambient Conditions

Directory of Open Access Journals (Sweden)

Ning Wang

2018-03-01

Full Text Available Nitrogen-vacancy (NV centers in diamond are attractive as quantum sensors owing to their superb coherence under ambient conditions. However, the NV center spin resonances are relatively insensitive to some important parameters such as temperature and pressure. Here we design and experimentally demonstrate a hybrid nanothermometer composed of NV centers and a magnetic nanoparticle (MNP, in which the temperature sensitivity is enhanced by the critical magnetization of the MNP near the ferromagnetic-paramagnetic transition temperature. The temperature susceptibility of the NV center spin resonance reaches 14  MHz/K, nearly 200 times larger than that of bare NV centers. The sensitivity of a hybrid nanothermometer composed of a Cu_{1-x}Ni_{x} MNP and a nanodiamond is measured to be 11  mK/sqrt[Hz] under ambient conditions. The working range of the hybrid thermometer can be designed from cryogenic temperature to about 600 K by tuning the chemical composition of the Cu_{1-x}Ni_{x} MNP. We demonstrate in situ detection of the magnetic phase transition of a single magnetic nanoparticle using the hybrid nanothermometer. This hybrid nanothermometer provides a novel approach to studying a broad range of thermal processes at nanoscales such as nanoplasmonics, heat-stimulated subcellular processes, and thermodynamics of nanosystems.

Understanding and Quantifying the Reactivity of Energetic NanoParticles and NanoComposites

Science.gov (United States)

2010-08-30

effect of the electric field on Al ion diffusion can be computed using the Nernst -Planck equation . The Nernst -Plank equation is given in equation 4 [22...4) R is the gas constant, and dP is the equilibrium vapor pressure of aluminum as determined by the Kelvin equation : 12...calculated by equation (5) and (6). 60 3exp 13.07 1.01 10 ( ) P T ev          Dyne/cm2

The role of printing parameters and scaffold biopolymer properties in the efficacy of a new hybrid nano-bioprinting system

Energy Technology Data Exchange (ETDEWEB)

Buyukhatipoglu, Kivilcim; Jo, Wonjin; Sun Wei; Clyne, Alisa Morss, E-mail: asm67@drexel.ed [Mechanical Engineering and Mechanics, Drexel University, 3141 Chestnut Street, Philadelphia, PA 19104 (United States)

2009-09-15

We created a hybrid nano-bioprinting system, which combines the initial patterning capabilities of direct cell writing with the active patterning capabilities of superparamagnetic nanoparticles. Biofabrication conditions, including printing parameters and scaffold biopolymer properties, may affect cell viability, nanoparticle manipulation and patterning capabilities. Nanoparticles were printed under varied conditions either in the biopolymer or loaded inside cells. Cell viability, alginate viscosity, nanoparticle movement and printing resolution were measured. We now show that while nanoparticles decreased cell viability, nozzle size had no significant effect. High printing pressure decreased cell viability, but viability loss was not accentuated by nanoparticles. High nanoparticle concentrations increased alginate viscosity at higher alginate concentrations. Nanoparticle velocity in response to a magnetic field was a function of nanoparticle diameter and scaffold viscosity, which agreed with a mathematical model of nanoparticle movement. Finally, the nano-bioprinting system resolution and patterning precision were not affected by nanoparticles in the prepolymer solution. These data suggest that nanoparticle incorporation in solid freeform fabrication does not change biofabrication parameters unless high nanoparticle concentrations are used. Future work includes developing vascularized tissue engineering constructs using the nano-bioprinting system.

The role of printing parameters and scaffold biopolymer properties in the efficacy of a new hybrid nano-bioprinting system

International Nuclear Information System (INIS)

Buyukhatipoglu, Kivilcim; Jo, Wonjin; Sun Wei; Clyne, Alisa Morss

2009-01-01

We created a hybrid nano-bioprinting system, which combines the initial patterning capabilities of direct cell writing with the active patterning capabilities of superparamagnetic nanoparticles. Biofabrication conditions, including printing parameters and scaffold biopolymer properties, may affect cell viability, nanoparticle manipulation and patterning capabilities. Nanoparticles were printed under varied conditions either in the biopolymer or loaded inside cells. Cell viability, alginate viscosity, nanoparticle movement and printing resolution were measured. We now show that while nanoparticles decreased cell viability, nozzle size had no significant effect. High printing pressure decreased cell viability, but viability loss was not accentuated by nanoparticles. High nanoparticle concentrations increased alginate viscosity at higher alginate concentrations. Nanoparticle velocity in response to a magnetic field was a function of nanoparticle diameter and scaffold viscosity, which agreed with a mathematical model of nanoparticle movement. Finally, the nano-bioprinting system resolution and patterning precision were not affected by nanoparticles in the prepolymer solution. These data suggest that nanoparticle incorporation in solid freeform fabrication does not change biofabrication parameters unless high nanoparticle concentrations are used. Future work includes developing vascularized tissue engineering constructs using the nano-bioprinting system.

Ceramic compositions based on nano forsterite/nano magnesium aluminate spinel powders

International Nuclear Information System (INIS)

Khattab, R.M.; Wahsh, M.M.S.; Khalil, N.M.

2015-01-01

According to the wide applications in the field of chemical and engineering industries, forsterite (Mg_2SiO_4)/spinel (MgAl_2O_4) ceramic compositions were the matter of interest of several research works during the last three decades. This work aims at preparation and characterization of improved ceramic bodies based on forsterite and spinel nano powders through controlling the forsterite and spinel contents in the prepared mixes. These prepared ceramic compositions have been investigated through measuring the densification parameters, cold crushing strength as well as volume resistively. Nano spinel was added from 0 to 30 mass% on expense of nano forsterite matrix and fired at 1550 °C for 2 h. The phase composition of the fired samples was examined using x-ray diffraction (XRD) technique. The microstructure of some selected samples was shown using scanning electron microscope (SEM). A pronounced improvement in the sintering, mechanical properties and volume resistively were achieved with increasing of nano spinel addition up to 15 mass%. This is due to the improvement in the matrix of the prepared forsterite/spinel bodies as a result of well distribution of spinel in the forsterite matrix as depicted by SEM analysis. - Highlights: • Ceramic compositions based on nano forsterite/nano-MgAl_2O_4 spinel were synthesized. • CCS was improved (333.78 MPa) through 15 mass% of nano-MgAl_2O_4 spinel addition. • Volume resistivity was enhanced to 203*10"1"3 Ohm cm with 15 mass% of spinel addition. • Beyond 15 mass% spinel, CCS and volume resistivity were decreased.

X-ray diffraction study of the fine structure of twaron fibres in the temperature range 750 kelvin - 9500 kelvin

International Nuclear Information System (INIS)

Abu Obaid, A. A.

1991-01-01

The thesis dealt with the fine structural behaviour of twaron fibres, spun from the polymer poly (p-phenylene terephthalamide), due to physical treatments in the temperature range 75 to 984 kelvin (-198 to 675 degrees celsius). The treatments were annealing, cooling, cold ageing and vibratory milling. The structure was characterized by wide-angle x-ray diffraction (WAXS) and thermogravimetric analysis (TGA). The structural parameters included crystallinity, microparacrystal (mPc) sizes, net plane spacings, unit cell dimensions and mass stability. The TGA results indicated good mass stability up to 500 degrees celsius. The crystallinity and mPc sizes reached their maximum values after annealing the fibres at 425 degrees celsius (crystallinity increased by 5% and mPC sizes increased by approximately 40 to 50 %). After 500 degrees celsius, the crystallinity and mPC sizes dropped remarkably. Cooling the twaron fibres down to -198 degrees celsius did not affect the structure. Cold ageing of the fibres at -15 degrees celsius for periods up to 100 days, and cold ageing at -198 degrees celsius up to 48 hours did not affect the structure as well; however cold ageing at -198 degrees celsius for 120 hours caused a drop of 5% in the crystallinity and 10% in the mPc sizes. 35 refs., 28 figs., 9 tabs. (A.M.H.)

Large-area super-resolution optical imaging by using core-shell microfibers

Science.gov (United States)

Liu, Cheng-Yang; Lo, Wei-Chieh

2017-09-01

We first numerically and experimentally report large-area super-resolution optical imaging achieved by using core-shell microfibers. The particular spatial electromagnetic waves for different core-shell microfibers are studied by using finite-difference time-domain and ray tracing calculations. The focusing properties of photonic nanojets are evaluated in terms of intensity profile and full width at half-maximum along propagation and transversal directions. In experiment, the general optical fiber is chemically etched down to 6 μm diameter and coated with different metallic thin films by using glancing angle deposition. The direct imaging of photonic nanojets for different core-shell microfibers is performed with a scanning optical microscope system. We show that the intensity distribution of a photonic nanojet is highly related to the metallic shell due to the surface plasmon polaritons. Furthermore, large-area super-resolution optical imaging is performed by using different core-shell microfibers placed over the nano-scale grating with 150 nm line width. The core-shell microfiber-assisted imaging is achieved with super-resolution and hundreds of times the field-of-view in contrast to microspheres. The possible applications of these core-shell optical microfibers include real-time large-area micro-fluidics and nano-structure inspections.

Nano-scale characterization of white layer in broached Inconel 718

Energy Technology Data Exchange (ETDEWEB)

Chen, Zhe, E-mail: zhe.chen@liu.se [Division of Engineering Materials, Linköping University, 58183 Linköping (Sweden); Colliander, Magnus Hörnqvist; Sundell, Gustav [Department of Physics, Chalmers University of Technology, 41296 Gothenburg (Sweden); Peng, Ru Lin [Division of Engineering Materials, Linköping University, 58183 Linköping (Sweden); Zhou, Jinming [Division of Production and Materials Engineering, Lund University, 22100 Lund (Sweden); Johansson, Sten; Moverare, Johan [Division of Engineering Materials, Linköping University, 58183 Linköping (Sweden)

2017-01-27

The formation mechanism of white layers during broaching and their mechanical properties are not well investigated and understood to date. In the present study, multiple advanced characterization techniques with nano-scale resolution, including transmission electron microscopy (TEM), transmission Kikuchi diffraction (TKD), atom probe tomography (APT) as well as nano-indentation, have been used to systematically examine the microstructural evolution and corresponding mechanical properties of a surface white layer formed when broaching the nickel-based superalloy Inconel 718. TEM observations showed that the broached white layer consists of nano-sized grains, mostly in the range of 20–50 nm. The crystallographic texture detected by TKD further revealed that the refined microstructure is primarily caused by strong shear deformation. Co-located Al-rich and Nb-rich fine clusters have been identified by APT, which are most likely to be γ′ and γ′′ clusters in a form of co-precipitates, where the clusters showed elongated and aligned appearance associated with the severe shearing history. The microstructural characteristics and crystallography of the broached white layer suggest that it was essentially formed by adiabatic shear localization in which the dominant metallurgical process is rotational dynamic recrystallization based on mechanically-driven subgrain rotations. The grain refinement within the white layer led to an increase of the surface nano-hardness by 14% and a reduction in elastic modulus by nearly 10% compared to that of the bulk material. This is primarily due to the greatly increased volume fraction of grain boundaries, when the grain size was reduced down to the nanoscale.

1D Nano materials 2012

International Nuclear Information System (INIS)

Yanqiu Zhu, Y.; Ma, R.; Whitby, R.; Acquah, S.

2013-01-01

We witnessed an initial hyped period and enthusiasm on carbon nano tubes in the 1990s later went through a significant expansion into nano tubes of other materials (metal di chalcogenides, boron nitride, etc.) as well as various nano wires and nano rods. While much of the hype might have gone, the research on one-dimensional (1D) nano materials has matured as one of the most active research areas within the nano science and nano technology community, flourishing with ample, exciting, and new research opportunities. Just like any other research frontier, researchers working in the 1D nano materials field are constantly striving to develop new fundamental science as well as potential applications. It remains a common belief that versatility and tunability of 1D nano materials would challenge many new rising tasks coming from our resource and energy demanding modern society. The traditional semiconductor industry has produced so many devices and systems from transistors, sensors, lasers, and LEDs to more sophisticated solar panels, which are now part of our daily lives. By down sizing the core components or parts to 1D form, one might wonder how fundamentally the dimensionality and morphology would impact the device performance, this is, as always, requiring us to fully understand the structure-property relationship in 1D nano materials. It may be equally crucial in connecting discovery-driven fundamental science to market-driven technology industry concerning potentially relevant findings derived from these novel materials. The importance of a platform that allows active researchers in this field to present their new development in a timely and efficient manner is therefore self-evident. Following the success of two early special issues devoted to 1D nano materials, this is the third one in a row organized by the same group of guest editors, attesting that such a platform has been well received by the readers

On Multiple Hall-Like Electron Currents and Tripolar Guide Magnetic Field Perturbations During Kelvin-Helmholtz Waves

Science.gov (United States)

Sturner, Andrew P.; Eriksson, Stefan; Nakamura, Takuma; Gershman, Daniel J.; Plaschke, Ferdinand; Ergun, Robert E.; Wilder, Frederick D.; Giles, Barbara; Pollock, Craig; Paterson, William R.; Strangeway, Robert J.; Baumjohann, Wolfgang; Burch, James L.

2018-02-01

Two magnetopause current sheet crossings with tripolar guide magnetic field signatures were observed by multiple Magnetosphere Multiscale (MMS) spacecraft during Kelvin-Helmholtz wave activity. The two out-of-plane magnetic field depressions of the tripolar guide magnetic field are largely supported by the observed in-plane electron currents, which are reminiscent of two clockwise Hall current loop systems. A comparison with a three-dimensional kinetic simulation of Kelvin-Helmholtz waves and vortex-induced reconnection suggests that MMS likely encountered the two Hall magnetic field depressions on either side of a magnetic reconnection X-line. Moreover, MMS observed an out-of-plane current reversal and a corresponding in-plane magnetic field rotation at the center of one of the current sheets, suggesting the presence of two adjacent flux ropes. The region inside one of the ion-scale flux ropes was characterized by an observed decrease of the total magnetic field, a strong axial current, and significant enhancements of electron density and parallel electron temperature. The flux rope boundary was characterized by currents opposite this axial current, strong in-plane and converging electric fields, parallel electric fields, and weak electron-frame Joule dissipation. These return current region observations may reflect a need to support the axial current rather than representing local reconnection signatures in the absence of any exhausts.

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

International Nuclear Information System (INIS)

2004-01-01

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

Fundamental Issues of Nano-fluid Behavior

International Nuclear Information System (INIS)

Williams, Wesley C.

2006-01-01

This paper will elucidate some of the behaviors of nano-fluids other than the abnormal conductivity enhancement, which are of importance to the experimental and engineering use of nano-fluids. Nano-fluid is the common name of any sol colloid involving nano-scale (less than 100 nm) sized particles dispersed within a base fluid. It has been shown previously that the dispersion of nano-particulate metallic oxides into water can increase thermal conductivity up to 30-40% over that of the base fluid and anomalously more than the mere weighed average of the colloid. There is a great potential for the use of nano-fluids as a way to enhance fluid/thermal energy transfer systems. Due to the recentness of nano-fluid science, there are still many issues which have not been fully investigated. This paper should act as a primer for the basic understanding of nano-fluid behavior. Particle size and colloid stability are of key importance to the functionality of nano-fluids. The pH and concentration/loading of nano-fluids can alter the size of the nano-particles and also the stability of the fluids. It will be shown through experiment and colloid theory the importance of these parameters. Furthermore, most of the existing literature uses volume percentage as the measure of particle loading, which can often be misleading. There will be discussion of this and other misleading ideas in nano-fluid science. (author)

Electrodeposition of nickel nano wire arrays

International Nuclear Information System (INIS)

Nur Ubaidah Saidin; Kok Kuan Ying; Ng Inn Khuan; Nurazila Mat Zali; Siti Salwa Zainal Abidin

2010-01-01

Synthesis, characterization and assembly of one-dimensional nickel nano wires prepared by template directed electrodeposition are discussed in this paper. Parallel arrays of high aspect ratio nickel nano wires were electrodeposited using electrolytes with different cations and pH. The nano wires were characterized using X-ray diffractometry and scanning electron microscopy. It was found that the orientations of the electro deposited Ni nano wires were governed by the deposition current and the electrolyte conditions. Free standing nickel nano wires can be obtained by dissolving the template. Due to the magnetic nature of the nano wires, magnetic alignment was employed to assemble and position the free standing nano wires in the device structure. (author)

Formation of Au nano-patterns on various substrates using simplified nano-transfer printing method

Science.gov (United States)

Kim, Jong-Woo; Yang, Ki-Yeon; Hong, Sung-Hoon; Lee, Heon

2008-06-01

For future device applications, fabrication of the metal nano-patterns on various substrates, such as Si wafer, non-planar glass lens and flexible plastic films become important. Among various nano-patterning technologies, nano-transfer print method is one of the simplest techniques to fabricate metal nano-patterns. In nano-transfer printing process, thin Au layer is deposited on flexible PDMS mold, containing surface protrusion patterns, and the Au layer is transferred from PDMS mold to various substrates due to the difference of bonding strength of Au layer to PDMS mold and to the substrate. For effective transfer of Au layer, self-assembled monolayer, which has strong bonding to Au, is deposited on the substrate as a glue layer. In this study, complicated SAM layer coating process was replaced to simple UV/ozone treatment, which can activates the surface and form the -OH radicals. Using simple UV/ozone treatments on both Au and substrate, Au nano-pattern can be successfully transferred to as large as 6 in. diameter Si wafer, without SAM coating process. High fidelity transfer of Au nano-patterns to non-planar glass lens and flexible PET film was also demonstrated.

Optimization of the energy resolution and of the radioactive background rejection for ionization-heat detectors equipped with thermometric thin films for the direct WIMPs detection; Optimisation du pouvoir de resolution et du rejet du fond radioactif de detecteurs ionisation-chaleur equipes de couches minces thermometriques pour la detection directe de WIMPS

Energy Technology Data Exchange (ETDEWEB)

Dolgorouky, Y.W.

2008-09-15

The EDELWEISS experiment aims at the direct detection of WIMPs as possible candidates for dark matter. It uses heat-and-ionization detectors that can discriminate these particles from the radioactive background. To date, this method is limited by events with incomplete charge collection that occur just beneath the detectors electrodes. In order to identify and reject these undesirable events, we have developed detectors equipped with thin films used both as thermometers - and hence sensitive to the transient athermal regime - and as electrodes for the charge collection. This thesis focuses on the optimization of such thin films regarding surface events rejection and on the modelling of the physical processes enabling this identification. The optimization must both maximize the fiducial volume and conserve an energy resolution such that the recoil energy threshold is of the order of 30 keV. Our work explores four generations of detectors each of which corresponds to successive evolutions in their conception. In all cases, the electrode-thermometer is an amorphous Anderson insulator NbSi thin film polarized by two interleaved comb-shaped niobium electrodes. In spite of constant progress in the successive detectors performances, the latest generation does not display the performances required for the EDELWEISS II experiment. Our work has shown the difficulty of the transient thermal signal modelling due to the complex contribution of the charge collection. This works has lead to new ideas regarding the detectors configuration, so that the athermal regime can be optimized to enhance both the rejection capability and the resolution. (author)

ac Conductivity analysis and dielectric relaxation behaviour of NaNO3-Al2O3 composites

International Nuclear Information System (INIS)

Anantha, P.S.; Hariharan, K.

2005-01-01

The electrical conductivity of NaNO 3 -xAl 2 O 3 composites has been studied over the wide range of temperature and frequency by means of impedance spectroscopy. The real part of the frequency dependent conductivity exhibits a simple power law feature and the dimensionless frequency exponent n has been determined. The conductivity spectra show scaling behaviour when the conductivity spectra are scaled by σ dc T, where T is temperature in Kelvin. The real part of dielectric permittivity shows saturation at higher frequencies and a strong dispersion at lower frequencies. The imaginary part of permittivity varies inversely with frequency, due to the presence of dc conductivity. The frequency dependent plots of M' and Z' show that the conductivity relaxation is non-Debye in nature. The Kohlrausch-Williams-Watts stretched exponential function was used to describe the modulus spectra and the stretching exponent β is found to be temperature independent. The conductivity relaxation time has been estimated from the modulus spectra. The activation energy responsible for relaxation has been evaluated and it was found to be almost same as that of dc conductivity

AC dielectrophoresis alignment of single-walled carbon nano tubes (SWNTS) and palladium nano wires for hydrogen gas sensor

International Nuclear Information System (INIS)

Nur Ubaidah Saidin; Nur Ubaidah Saidin; Ying, K.K.; KKhuan, N.I.; Mohammad Hafizuddin Jumali

2013-01-01

Full-text: Using AC electric field, nano wires or nano tubes can be aligned, chained or accelerated in a direction parallel to the applied field, oriented or concentrated onto designated locations as well as dispersed in controlled manner under high efficiencies. In this work, systematic study on the alignment of nano wires/ nano tubes across the 3 μm-gaps between pairs of micro fabricated gold electrodes was carried out using AC dielectrophoresis technique. Densities and alignment of the nano wires/ nano tubes across the gaps of the electrodes were controlled by the applied AC field strengths and frequencies on the electrodes. Good alignments of SWNTs and Pd nano wires were achieved at an applied frequency of 5 MHz and a field strength as high as 25 V pp for Pd nano wires compared to only 2 V pp for SWNTs. The aligned nano wires/ nano tubes will be functioned as sensor elements for hydrogen gas sensing. (author)

Super-resolution fluorescence imaging of nanoimprinted polymer patterns by selective fluorophore adsorption combined with redox switching

KAUST Repository

Yabiku, Y.; Kubo, S.; Nakagawa, M.; Vacha, M.; Habuchi, Satoshi

2013-01-01

We applied a super-resolution fluorescence imaging based on selective adsorption and redox switching of the fluorescent dye molecules for studying polymer nanostructures. We demonstrate that nano-scale structures of polymer thin films can

Nano-ceramics and its molding technologies

International Nuclear Information System (INIS)

Liu Jian; Xu Yunshu

2007-01-01

Nano-ceramics and its related knowledge were introduced. Fabrication of nano-ceramic powder, as well as the molding and sintering technologies of nano-ceramics were reviewed. Features of the present molding technologies were analyzed. The applications of nano-ceramics were prospected. (authors)

Phosphorylated nano-diamond/ Polyimide Nanocomposites

International Nuclear Information System (INIS)

Beyler-Çiǧil, Asli; Çakmakçi, Emrah; Kahraman, Memet Vezir

2014-01-01

In this study, a novel route to synthesize polyimide (PI)/phosphorylated nanodiamond films with improved thermal and mechanical properties was developed. Surface phosphorylation of nano-diamond was performed in dichloromethane. Phosphorylation dramatically enhanced the thermal stability of nano-diamond. Poly(amic acid) (PAA), which is the precursor of PI, was successfully synthesized with 3,3',4,4'-Benzophenonetetracarboxylic dianhydride (BTDA) and 4,4'-oxydianiline (4,4'-ODA) in the solution of N,N- dimethylformamide (DMF). Pure BTDA-ODA polyimide films and phosphorylated nanodiamond containing BTDA-ODA PI films were prepared. The PAA displayed good compatibility with phosphorylated nano-diamond. The morphology of the polyimide (PI)/phosphorylated nano-diamond was characterized by scanning electron microscopy (SEM). Chemical structure of polyimide and polyimide (PI)/phosphorylated nano-diamond was characterized by FTIR. SEM and FTIR results showed that the phosphorylated nano-diamond was successfully prepared. Thermal properties of the polyimide (PI)/phosphorylated nanodiamond was characterized by thermogravimetric analysis (TGA). TGA results showed that the thermal stability of (PI)/phosphorylated nano-diamond film was increased

Nano surface generation of grinding process using carbon nano tubes

Indian Academy of Sciences (India)

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

Ion microbeam analysis. Application to the study of the skin barrier and its nano-toxicology

International Nuclear Information System (INIS)

Simon, M.

2009-12-01

This work is dedicated to the use of ion microbeam irradiation to the study of a complex biological tissue like skin. Up to now, it has been very difficult to detect and track metallic oxides and manufactured nano-particles in biological tissues, most particularly in skin. Thus, it is essential to precise the mechanisms involved in skin barrier function processes face to exogenous agents like nano-particles and to characterize them in biological models in vitro/in vivo. During my work, I have had the opportunity to combine quantitative methods of analysis with high resolution imagery techniques (confocal microscopy, transmission electron microscopy and ion beam analysis) in order to characterize: (i) the skin barrier function of an ex vivo pig ear skin model understanding the ion homeostasis behavior face to different chemical or physical stresses; (ii) the impact on viability, accumulation and intracellular distribution of nano-particles (Titanium Oxides) naked or functionalized with fluorescent dyes (FITC, Rhodamine)

To see or not to see: Imaging surfactant coated nano-particles using HIM and SEM

International Nuclear Information System (INIS)

Hlawacek, Gregor; Ahmad, Imtiaz; Smithers, Mark A.; Kooij, E. Stefan

2013-01-01

Nano-particles are of great interest in fundamental and applied research. However, their accurate visualization is often difficult and the interpretation of the obtained images can be complicated. We present a comparative scanning electron microscopy and helium ion microscopy study of cetyltrimethylammonium-bromide (CTAB) coated gold nano-rods. Using both methods we show how the gold core as well as the surrounding thin CTAB shell can selectively be visualized. This allows for a quantitative determination of the dimensions of the gold core or the CTAB shell. The obtained CTAB shell thickness of 1.0 nm–1.5 nm is in excellent agreement with earlier results using more demanding and reciprocal space techniques. - Author-Highlights: • CTAB coated gold nano-rods were imaged using high resolution imaging tools. • Selective imaging of either the gold core or CTAB shell is possible with HIM and SEM. • CTAB shell thickness measured using HIM and SEM agrees well with literature values

MHD Kelvin-Helmholtz instability in non-hydrostatic equilibrium

International Nuclear Information System (INIS)

Laghouati, Y; Bouabdallah, A; Zizi, M; Alemany, A

2007-01-01

The present work deals with the linear stability of a magnetohydrodynamic shear flow so that a stratified inviscid fluid rotating about a vertical axis when a uniform magnetic field is applied in the direction of the streaming or zonal flow. In geophysical flow, the stability of the flow is determined by taking into account the nonhydrostatic condition depending on Richardson number R i and the deviation δ from hydrostatic equilibrium. According to Stone (Stone P H 1971 J. Fluid. Mech. 45 659), it is shown that such deviation δ decreases the growth rates of three kinds of instability which can appear as geostrophic (G), symmetric (S) and Kelvin-Helmholtz (K-H) instabilities. To be specific, the evolution of the flow is therefore considered in the light of the influence of magnetic field, particularly, on K-H instability. The results of this study are presented by the linear stability of a magnetohydrodynamic, with horizontal free-shear flow of stratified fluid, subject to rotation about the vertical axis and uniform magnetic field in the zonal direction. Results are discussed and compared to previous works as Chandrasekhar (Chandrasekhar S 1961 Hydrodynamic and hydromagnetic stability (Oxford: Clarendon Press) chapter 11 pp 481-513) and Stone

Pharmaceutical Applications of Polymeric Nano materials

International Nuclear Information System (INIS)

Wu, L.; Sun, L.

2011-01-01

With significant attention focused on nano science and nano technology in recent years, nano materials have been used in a wide variety of applications such as automotive, environmental, energy, catalysis, biomedical, drug delivery, and polymeric industries. Among those fields, the application of nano materials with pharmaceutical science is an emerging and rapidly growing field and has drawn increasing attention recently. Research and development in this field is mainly focused on several aspects such as the discoveries of novel functional nano materials, exploration on nanoparticles with controlled and targeted drug delivery characteristics, and investigation of bio functionalized and diagnostic nano materials. In this special issue, we have invited a few papers related to recent advances in pharmaceutical application of polymeric nano materials

Temperature and other data were collected using thermometer and bottle casts in the Chukchi and Bering Sea from 1947-02-11 to 1949-07-26 (NODC Accession 9700081)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Temperature, depth, oxygen, and salinity data were collected using thermometer and bottle casts from the USS CACOPAN, USS NEREUS, and HMCS CEDARWOOD in the Chukchi...

Direct nano-patterning of graphene with helium ion beams

International Nuclear Information System (INIS)

Naitou, Y.; Iijima, T.; Ogawa, S.

2015-01-01

Helium ion microscopy (HIM) was used for direct nano-patterning of single-layer graphene (SLG) on SiO 2 /Si substrates. This technique involves irradiation of the sample with accelerated helium ions (He + ). Doses of 2.0 × 10 16  He +  cm −2 from a 30 kV beam induced a metal-insulator transition in the SLG. The resolution of HIM patterning on SLG was investigated by fabricating nanoribbons and nanostructures. Analysis of scanning capacitance microscopy measurements revealed that the spatial resolution of HIM patterning depended on the dosage of He + in a non-monotonic fashion. Increasing the dose from 2.0 × 10 16 to 5.0 × 10 16  He +  cm −2 improved the spatial resolution to several tens of nanometers. However, doses greater than 1.0 × 10 17  He +  cm −2 degraded the patterning characteristics. Direct patterning using HIM is a versatile approach to graphene fabrication and can be applied to graphene-based devices

The impact of nano-coating on surface charge accumulation of epoxy resin insulator: characteristic and mechanism

Science.gov (United States)

Qi, Bo; Gao, Chunjia; Lv, Yuzhen; Li, Chengrong; Tu, Youping; Xiong, Jun

2018-06-01

The flashover phenomenon of the insulator is the main cause for insulating failure of GIS/GIL, and one of the most critical impacting factors is the accumulation of surface charge. The common methods to restrain the surface charge accumulation are reviewed in this paper. Through the reasonable comparison and analysis of these methods, nano-coatings for the insulator were selected as a way to restrain the surface charge accumulation. Based on this, six nano-coated epoxy resin samples with different concentrations of P25-TiO2 nanoparticles were produced. A high precision 3D surface charge measurement system was developed in this paper with a spatial resolution of 4.0 mm2 and a charge resolution of 0.01 µC (m2 · mV)‑1. The experimental results for the epoxy resin sample showed that with the concentration of nanoparticles of the coating material increasing, the surface charge density tended to first decrease and then increase. In the sample coated with 0.5% concentration of nanoparticles, the suppression effect is the optimum, leading to a 63.8% reduction of charge density under DC voltage. The application test for actual nano-coated GIS/GIL basin insulator indicated that the maximum suppression degree for the charge density under DC voltage could reach 48.3%, while it could reach 22.2% for switching impulse voltage and 12.5% for AC context. The control mechanism of nano-coatings on charge accumulation was proposed based on the analysis for surface morphology features and traps characteristics; the shallow traps dominate in the migration of charges while the deep traps operate on the charge accumulation. With the concentration of nanoparticles in nano-coating material mounting up, the density of shallow traps continuously increases, while for deep traps, it first decreases and then increases. For the sample with 0.5% concentration of nanoparticles coated, the competition between shallow traps and deep traps comes to the most balanced state, producing the most

A monocrystal of 59Co as a nuclear orientation thermometer in neutron experiments with oriented targets

International Nuclear Information System (INIS)

Fasoli, U.; Galeazzi, G.; Pavan, P.; Toniolo, D.; Zago, G.; Zannoni, R.

1980-01-01

An apparatus for measuring temperatures in the millikelvin region is described based on the 'deformation effect' on fast neutron transmission through an aligned 59 Co monocrystal, employing a 252 Cf pill as the neutron source. A statistical accuracy of a few percent in a few minutes is obtainable with a heat input of some tens of pW. The apparatus is suitable in neutron experiments with oriented targets when the gamma-ray background hinders the use of gamma-ray anisotropy thermometers. In these and similar cases, in which the temperature must be held constant for long periods, the large heat capacity of the cobalt sample is not a drawback. (orig.)

Nano structures for Medical Diagnostics Md

International Nuclear Information System (INIS)

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

2012-01-01

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

Elemental imaging at the nanoscale: NanoSIMS and complementary techniques for element localisation in plants.

Science.gov (United States)

Moore, Katie L; Lombi, Enzo; Zhao, Fang-Jie; Grovenor, Chris R M

2012-04-01

The ability to locate and quantify elemental distributions in plants is crucial to understanding plant metabolisms, the mechanisms of uptake and transport of minerals and how plants cope with toxic elements or elemental deficiencies. High-resolution secondary ion mass spectrometry (SIMS) is emerging as an important technique for the analysis of biological material at the subcellular scale. This article reviews recent work using the CAMECA NanoSIMS to determine elemental distributions in plants. The NanoSIMS is able to map elemental distributions at high resolution, down to 50 nm, and can detect very low concentrations (milligrams per kilogram) for some elements. It is also capable of mapping almost all elements in the periodic table (from hydrogen to uranium) and can distinguish between stable isotopes, which allows the design of tracer experiments. In this review, particular focus is placed upon studying the same or similar specimens with both the NanoSIMS and a wide range of complementary techniques, showing how the advantages of each technique can be combined to provide a fuller data set to address complex scientific questions. Techniques covered include optical microscopy, synchrotron techniques, including X-ray fluorescence and X-ray absorption spectroscopy, transmission electron microscopy, electron probe microanalysis, particle-induced X-ray emission and inductively coupled plasma mass spectrometry. Some of the challenges associated with sample preparation of plant material for SIMS analysis, the artefacts and limitations of the technique and future trends are also discussed.

Interactions between two magnetohydrodynamic Kelvin-Helmholtz instabilities

International Nuclear Information System (INIS)

Lai, S. H.; Ip, W.-H.

2011-01-01

Kelvin-Helmholtz instability (KHI) driven by velocity shear is a generator of waves found away from the vicinity of the velocity-shear layers since the fast-mode waves radiated from the surface perturbation can propagate away from the transition layer. Thus the nonlinear evolution associated with KHI is not confined near the velocity-shear layer. To understand the physical processes in multiple velocity-shear layers, the interactions between two KHIs at a pair of tangential discontinuities are studied by two-dimensional magnetohydrodynamic simulations. It is shown that the interactions between two neighboring velocity-shear layers are dominated by the propagation of the fast-mode waves radiated from KHIs in a nonuniform medium. That is, the fast-mode Mach number of the surface waves M Fy , a key factor of the nonlinear evolution of KHI, will vary with the nonuniform background plasma velocity due to the existence of two neighboring velocity-shear layers. As long as the M Fy observed in the plasma rest frame across the neighboring velocity-shear layer is larger than one, newly formed fast-mode Mach-cone-like (MCL) plane waves generated by the fast-mode waves can be found in this region. As results of the interactions of two KHIs, reflection and distortion of the MCL plane waves generate the turbulence and increase the plasma temperature, which provide possible mechanisms of heating and accelerating local plasma between two neighboring velocity-shear layers.

Manipulation and functionalization of nano-tubes: application to boron nitride nano-tubes

International Nuclear Information System (INIS)

Maguer, A.

2007-01-01

This PhD work is divided into two parts dealing with boron nitride (BNNT) and carbon nano-tubes. The first part is about synthesis, purification and chemical functionalization of BNNT. Single-walled BNNT are synthesized by LASER ablation of a hBN target. Improving the synthesis parameters first allowed us to limit the byproducts (hBN, boric acid). A specific purification process was then developed in order to enrich the samples in nano-tubes. Purified samples were then used to develop two new chemical functionalization methods. They both involve chemical molecules that present a high affinity towards the BN network. The use of long chain-substituted quinuclidines and borazines actually allowed the solubilization of BNNT in organic media. Purification and functionalization were developed for single-walled BNNT and were successfully applied to multi-walled BNNT. Sensibility of boron to thermic neutrons finally gave birth to a study about covalent functionalization possibilities of the network. The second part of the PhD work deals with separation of carbon nano-tubes depending on their properties. Microwave irradiation of carbon nano-tubes first allowed the enrichment of initially polydisperse samples in large diameter nano-tubes. A second strategy involving selective interaction between one type of tubes and fullerene micelles was finally envisaged to selectively solubilize carbon nano-tubes with specific electronic properties. (author) [fr

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

International Nuclear Information System (INIS)

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

2012-01-01

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

Spatial coherence of electron beams from field emitters and its effect on the resolution of imaged objects

Energy Technology Data Exchange (ETDEWEB)

Latychevskaia, Tatiana, E-mail: tatiana@physik.uzh.ch

2017-04-15

Sub-nanometer and nanometer-sized tips provide high coherence electron sources. Conventionally, the effective source size is estimated from the extent of the experimental biprism interference pattern created on the detector by applying the van Cittert Zernike theorem. Previously reported experimental intensity distributions on the detector exhibit Gaussian distribution and our simulations show that this is an indication that such electron sources must be at least partially coherent. This, in turn means that strictly speaking the Van Cittert Zernike theorem cannot be applied, since it assumes an incoherent source. The approach of applying the van Cittert Zernike theorem is examined in more detail by performing simulations of interference patterns for the electron sources of different size and different coherence length, evaluating the effective source size from the extent of the simulated interference pattern and comparing the obtained result with the pre-defined value. The intensity distribution of the source is assumed to be Gaussian distributed, as it is observed in experiments. The visibility or the contrast in the simulated holograms is found to be always less than 1 which agrees well with previously reported experimental results and thus can be explained solely by the Gaussian intensity distribution of the source. The effective source size estimated from the extent of the interference pattern turns out to be of about 2–3 times larger than the pre-defined size, but it is approximately equal to the intrinsic resolution of the imaging system. A simple formula for estimating the intrinsic resolution, which could be useful when employing nano-tips in in-line Gabor holography or point-projection microscopy, is provided. - Highlights: • van Cittert Zernike theorem for nano- and sub-nano electron emitting tips is revised. • Simulations show that nano- and sub-nano electron emitting tips are at least partially coherent. • A simple formula for evaluating

Nano Fertilizers

Directory of Open Access Journals (Sweden)

Hatice DAĞHAN

2017-06-01

Full Text Available Agricultural land is decreasing day by day due to erosion, environmental pollution, unconscious irrigation and fertilization. On the other hand, it is necessary to increase agricultural production in order to meet the needs of the developing industry as well as the nutritional needs of the growing population. In the recent years, nano fertilizers have begun to be produced to obtain the highest amount and quality of production from the unit area. Previous research shows that nano fertilizers cause an increase in the use efficiency of plant nutrients, reduce soil toxicity, minimize the potential adverse effects of excessive chemical fertilizer use, and reduce fertilizer application frequency. Nano fertilizers are important in agriculture to increase crop yield and nutrient use efficiency, and to reduce excessive use ofchemical fertilizers. The most important properties of these fertilizers are that they contain one or more of macro and micronutrients, they can be applied frequently in small amounts and are environmentally friendly. However, when applied at high doses, they exhibit decreasing effects on plant growth and crop yields, similar to chemical fertilizers. In this review, the definition, importan ce, and classification of nano fertilizers, their application in plant production, advantages and disadvantages and the results obtained in this field were discussed.

Superconducting Mercury-Based Cuprate Films with a Zero-Resistance Transition Temperature of 124 Kelvin

Science.gov (United States)

Tsuei, C. C.; Gupta, A.; Trafas, G.; Mitzi, D.

1994-03-01

The synthesis of high-quality films of the recently discovered mercury-based cuprate films with high transition temperatures has been plagued by problems such as the air sensitivity of the cuprate precursor and the volatility of Hg and HgO. These processing difficulties have been circumvented by a technique of atomic-scale mixing of the HgO and cuprate precursors, use of a protective cap layer, and annealing in an appropriate Hg and O_2 environment. With this procedure, a zero-resistance transition temperature as high as 124 kelvin in c axis-oriented epitaxial HgBa_2CaCu_2O6+δ films has been achieved.

Superconducting mercury-based cuprate films with a zero-resistance transition temperature of 124 Kelvin.

Science.gov (United States)

Tsuei, C C; Gupta, A; Trafas, G; Mitzi, D

1994-03-04

The synthesis of high-quality films of the recently discovered mercury-based cuprate films with high transition temperatures has been plagued by problems such as the air sensitivity of the cuprate precursor and the volatility of Hg and HgO. These processing difficulties have been circumvented by a technique of atomic-scale mixing of the HgO and cuprate precursors, use of a protective cap layer, and annealing in an appropriate Hg and O(2) environment. With this procedure, a zero-resistance transition temperature as high as 124 kelvin in c axis-oriented epitaxial HgBa(2)CaCu(2)O(6+delta) films has been achieved.

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

Science.gov (United States)

Khlobystov, Andrei N

2011-12-27

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

NANO-SQUIDs based on niobium Dayem bridges for nanoscale applications

Energy Technology Data Exchange (ETDEWEB)

Granata, C; Esposito, E; Nappi, C; Ruggiero, B; Russo, M [Istituto di Cibernetica ' E. Caianiello' del Consiglio Nazionale delle Ricerche, 80078 Pozzuoli (Napoli) (Italy); Vettoliere, A; Walke, P [Also Universita degli Studi di Napoli ' Federico II' , Napoli (Italy); Silvestrini, P, E-mail: c.granata@cib.na.cnr.i [Dipartimento di Ingegneria dell' Informazione, Seconda Universita degli Studi di Napoli, Aversa(Caserta) (Italy)

2010-06-01

We report on the design, the fabrication and the performance of an integrated magnetic nano-sensor based on niobium dc-SQUID (Superconducting QUantum Interference Device) for nanoscale applications is presented. The nano-sensors are based on nanometric niobium constrictions (Dayem bridges) inserted in a square loop having a side length of 200 nm. Measurements of voltage-flux characteristic, flux to voltage transfer factor and noise performances are reported. In small signal mode, the sensors have shown a magnetic flux noise spectral density of 1.5 {mu}{Phi}{sub 0}/Hz{sup 1/2} corresponding to a spin sensitivity in unit of Bohr magneton of 60 spin/Hz{sup 1/2}. Supercurrent decay measurements of these devices are also reported. Such measurements provide useful information for applications which employ the SQUID as a trigger where the sensor works on the zero voltage state. The experimental data, have shown an intrinsic current fluctuation less than 0.2% of the critical current at liquid helium temperature, corresponding to an intrinsic sensor magnetic flux resolution of a few m{Phi}{sub 0}. In view of the nano-SQUID employments in the detection of small spin populations, the authors calculated the spin sensitivity and the magnetic response relative to the single spin, as a function of its position within the SQUID hole. The results show that the SQUID response depends strongly on the spin position.

Nano-cellulose biopolymer based nano-biofilm biomaterial using plant biomass: An innovative plant biomaterial dataset

Directory of Open Access Journals (Sweden)

A.B.M. Sharif hossain

2018-04-01

Full Text Available The nano-cellulose derived nano-biofilm keeps a magnificent role in medical, biomedical, bioengineering and pharmaceutical industries. Plant biomaterial is naturally organic and biodegradable. This study has been highlighted as one of the strategy introducing biomass based nano-bioplastic (nanobiofilm to solve dependency on petroleum and environment pollution because of non-degradable plastic. The data study was carried out to investigate the nano-biopolymer (nanocellulose based nano-biofilm data from corn leaf biomass coming after bioprocess technology without chemicals. Corn leaf biomass was used to produce biodegradable nano-bioplastic for medical and biomedical and other industrial uses. Data on water absorption, odor, pH, cellulose content, shape and firmness, color coating and tensile strength test have been exhibited under standardization of ASTM (American standard for testing and materials. Moreover, the chemical elements of nanobiofilm like K+, CO3−−, Cl−, Na+ showed standard data using the EN (166. Keywords: Nanocellulose, Nanobiofilm, Nanobioplastic, Biodegradable, Corn leaf

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

International Nuclear Information System (INIS)

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

2011-01-01

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

The Art of Photoelectron Spectroscopy, from Micro to Nano

Science.gov (United States)

Rotenberg, Eli

Angle-resolved photoemission spectroscopy (ARPES) was developed for the determination of the electronic bandstructure of solids. In the last 20 years, ARPES has become nearly unlimited with respect to instrumental resolution, and therefore able to illuminate more subtle electronic aspects, such as ground-state symmetry breaking and the many-body interactions (MBIs) that characterize ground states such as superconductivity. These MBIs involve exchange of momentum among electrons or with excitations such as phonons, and can therefore couple to nanoscale structures. By controlling the structure at the nanoscale, we can therefore hope to control or enhance the ground state properties of materials through nanoscale engineering. This dream has motivated the development of nanoscale ARPES (nanoARPES) machines that are now coming online worldwide. After a brief overview, I will show the latest results from the new nanoARPES endstation at the MAESTRO facility (Microscopic and Electronic Structure Observatory), a new user beamline commissioned this year at the Advanced Light Source (ALS). We achieved routine operation at spatial resolution around 120 nm, and expect improvement down to 50 nm or better. Examples will include graphene and 2D-metal-chalcogenide heterostructures. I will also discuss the prospects for dramatic improvements expected as new diffraction-limited light sources such as the ALS-U project are realized. Work performed at the Advanced Light Source is supported by the Director, Office of Science, Office of Basic Energy Sciences, of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231.

Aligned Layers of Silver Nano-Fibers

Directory of Open Access Journals (Sweden)

Andrii B. Golovin

2012-02-01

Full Text Available We describe a new dichroic polarizers made by ordering silver nano-fibers to aligned layers. The aligned layers consist of nano-fibers and self-assembled molecular aggregates of lyotropic liquid crystals. Unidirectional alignment of the layers is achieved by means of mechanical shearing. Aligned layers of silver nano-fibers are partially transparent to a linearly polarized electromagnetic radiation. The unidirectional alignment and density of the silver nano-fibers determine degree of polarization of transmitted light. The aligned layers of silver nano-fibers might be used in optics, microwave applications, and organic electronics.

Self-aligned periodic Ni nano dots embedded in nano-oxide layer

International Nuclear Information System (INIS)

Doi, M.; Izumi, M.; Kawasaki, S.; Miyake, K.; Sahashi, M.

2007-01-01

The Ni nano constriction dots embedded in the Ta-nano-oxide layer (NOL) was prepared by the ion beam sputtering (IBS) method. After the various conditions of the oxidations, the structural analyses of the NOL were performed by RHEED, AES and in situ STM/AFM observations. From the current image of the conductive AFM for NOL, the periodically aligned metallic dots with the size around 5-10 nm were successfully observed. The mechanism of the formation of the self-organized aligned Ni nano constriction dots is discussed from the standpoint of the grain size, the crystal orientation, the preferred oxidation of Ta at the diffused interface

Review on Nano SeleniumProduced by Bacteria

Directory of Open Access Journals (Sweden)

LI Ji-xiang

2014-12-01

Full Text Available Selenium (Se is a kind of essential trace element for people and animal, while ionic state of selenium is toxic with high concentrations and will cause the selenium pollution. Nano-selenium is stable, nontoxic with higher biological activity. Application of bacteria reducing selenite or selenate to biological nano-selenium has great potential in selenium pollution control and nano-selenium production. This review summarizes the research progress of the red elemental nano-selenium reduced by bacteria including characteristics and application of nano-selenium, effects of carbon and nitrogen source, oxygen, temperature and pH in bacteria nano-selenium production, and molecular mechanisms of nano-selenium reduced by bacteria.

Optimization of the energy resolution and of the radioactive background rejection for ionization-heat detectors equipped with thermometric thin films for the direct WIMPs detection

International Nuclear Information System (INIS)

Dolgorouky, Y.W.

2008-09-01

The EDELWEISS experiment aims at the direct detection of WIMPs as possible candidates for dark matter. It uses heat-and-ionization detectors that can discriminate these particles from the radioactive background. To date, this method is limited by events with incomplete charge collection that occur just beneath the detectors electrodes. In order to identify and reject these undesirable events, we have developed detectors equipped with thin films used both as thermometers - and hence sensitive to the transient athermal regime - and as electrodes for the charge collection. This thesis focuses on the optimization of such thin films regarding surface events rejection and on the modelling of the physical processes enabling this identification. The optimization must both maximize the fiducial volume and conserve an energy resolution such that the recoil energy threshold is of the order of 30 keV. Our work explores four generations of detectors each of which corresponds to successive evolutions in their conception. In all cases, the electrode-thermometer is an amorphous Anderson insulator NbSi thin film polarized by two interleaved comb-shaped niobium electrodes. In spite of constant progress in the successive detectors performances, the latest generation does not display the performances required for the EDELWEISS II experiment. Our work has shown the difficulty of the transient thermal signal modelling due to the complex contribution of the charge collection. This works has lead to new ideas regarding the detectors configuration, so that the athermal regime can be optimized to enhance both the rejection capability and the resolution. (author)

Metal Oxide Nano structures: Synthesis, Properties, and Applications

International Nuclear Information System (INIS)

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

2015-01-01

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

Nano-JASMINE Data Analysis and Publication

Science.gov (United States)

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

2012-09-01

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

Nano-Crystalline Diamond Films with Pineapple-Like Morphology Grown by the DC Arcjet vapor Deposition Method

Science.gov (United States)

Li, Bin; Zhang, Qin-Jian; Shi, Yan-Chao; Li, Jia-Jun; Li, Hong; Lu, Fan-Xiu; Chen, Guang-Chao

2014-08-01

A nano-crystlline diamond film is grown by the dc arcjet chemical vapor deposition method. The film is characterized by scanning electron microscopy, high-resolution transmission electron microscopy (HRTEM), x-ray diffraction (XRD) and Raman spectra, respectively. The nanocrystalline grains are averagely with 80 nm in the size measured by XRD, and further proven by Raman and HRTEM. The observed novel morphology of the growth surface, pineapple-like morphology, is constructed by cubo-octahedral growth zones with a smooth faceted top surface and coarse side surfaces. The as-grown film possesses (100) dominant surface containing a little amorphous sp2 component, which is far different from the nano-crystalline film with the usual cauliflower-like morphology.

Kelvin probe studies of cesium telluride photocathode for AWA photoinjector

Energy Technology Data Exchange (ETDEWEB)

Wisniewski, Eric E., E-mail: ewisniew@anl.gov [High Energy Physics Division, Argonne National Laboratory, 9700 S. Cass, Lemont, IL 60439 (United States); Physics Department, Illinois Institute of Technology, 3300 South Federal Street, Chicago, IL 60616 (United States); Velazquez, Daniel [High Energy Physics Division, Argonne National Laboratory, 9700 S. Cass, Lemont, IL 60439 (United States); Physics Department, Illinois Institute of Technology, 3300 South Federal Street, Chicago, IL 60616 (United States); Yusof, Zikri, E-mail: zyusof@hawk.iit.edu [High Energy Physics Division, Argonne National Laboratory, 9700 S. Cass, Lemont, IL 60439 (United States); Physics Department, Illinois Institute of Technology, 3300 South Federal Street, Chicago, IL 60616 (United States); Spentzouris, Linda; Terry, Jeff [Physics Department, Illinois Institute of Technology, 3300 South Federal Street, Chicago, IL 60616 (United States); Sarkar, Tapash J. [Rice University, 6100 Main, Houston, TX 77005 (United States); Harkay, Katherine [Accelerator Science Division, Argonne National Laboratory, 9700 S. Cass, Lemont, IL 60439 (United States)

2013-05-21

Cesium telluride is an important photocathode as an electron source for particle accelerators. It has a relatively high quantum efficiency (>1%), is sufficiently robust in a photoinjector, and has a long lifetime. This photocathode is grown in-house for a new Argonne Wakefield Accelerator (AWA) beamline to produce high charge per bunch (≈50nC) in a long bunch train. Here, we present a study of the work function of cesium telluride photocathode using the Kelvin probe technique. The study includes an investigation of the correlation between the quantum efficiency and the work function, the effect of photocathode aging, the effect of UV exposure on the work function, and the evolution of the work function during and after photocathode rejuvenation via heating. -- Highlights: ► The correlation between Quantum Efficiency (QE) and work function. ► How QE and work function evolve together. ► Rejuvenation of the photocathode via heating and the effect on work function. ► The effects on the work function due to exposure to UV light.