scholarly journals Toward Real-Time Monitoring and Control of Single Nanoparticle Properties with a Microbubble Resonator Spectrometer

2019 ◽  
Author(s):  
Levi Hogan ◽  
Erik Horak ◽  
Jonathan Ward ◽  
Kassandra Knapper ◽  
Síle Nic Chormaic ◽  
...  
Keyword(s):  
Single Particle ◽  
Stable Solution ◽  
New Method ◽  
Monitoring And Control ◽  
Experimental Conditions ◽  
Widespread Application ◽  
Time Resolved ◽  
Biologically Relevant ◽  
Rapid Acquisition ◽  
Free Environment

<p></p><p></p><p>Optical microresonators have widespread application at the frontiers of nanophotonic technology, driven by their ability to confine light to the nanoscale and enhance light-matter interactions. Microresonators form the heart of a new method for single-particle photothermal absorption spectroscopy, whereby the microresonators act as microscale thermometers to detect the heat dissipated by optically pumped, non-luminescent nanoscopic targets. However, translation of this technology to chemically dynamic systems requires a platform that is mechanically stable, solution compatible, and visibly transparent. We report microbubble absorption spectrometers as a new and versatile platform that meets these requirements. Microbubbles integrate a two-port microfluidic device within a Whispering Gallery Mode (WGM) microresonator, allowing for the facile exchange of chemical reagents within the resonator’s interior while maintaining a solution-free environment on its exterior. We first leverage these qualities to investigate the photo-activated etching of single gold nanorods by ferric chloride, providing a new method for rapid acquisition of spatial and morphological information about nanoparticles as they undergo chemical reactions. We then demonstrate the ability to control nanorod orientation within a microbubble through optically exerted torque, a new route toward the construction of hybrid photonic-plasmonic systems. Critically, the reported platform advances microresonator spectrometer technology by permitting room-temperature, aqueous experimental conditions, opening a regime of time-resolved single-particle experiments on non-emissive, nanoscale analytes engaged in catalytically and biologically relevant chemical dynamics.</p><p></p><p></p>

Toward Real-Time Monitoring and Control of Single Nanoparticle Properties with a Microbubble Resonator Spectrometer

2019 ◽  
Author(s):  
Levi Hogan ◽  
Erik Horak ◽  
Jonathan Ward ◽  
Kassandra Knapper ◽  
Síle Nic Chormaic ◽  
...  
Keyword(s):  
Single Particle ◽  
Stable Solution ◽  
New Method ◽  
Monitoring And Control ◽  
Experimental Conditions ◽  
Widespread Application ◽  
Time Resolved ◽  
Biologically Relevant ◽  
Rapid Acquisition ◽  
Free Environment

<p></p><p></p><p>Optical microresonators have widespread application at the frontiers of nanophotonic technology, driven by their ability to confine light to the nanoscale and enhance light-matter interactions. Microresonators form the heart of a new method for single-particle photothermal absorption spectroscopy, whereby the microresonators act as microscale thermometers to detect the heat dissipated by optically pumped, non-luminescent nanoscopic targets. However, translation of this technology to chemically dynamic systems requires a platform that is mechanically stable, solution compatible, and visibly transparent. We report microbubble absorption spectrometers as a new and versatile platform that meets these requirements. Microbubbles integrate a two-port microfluidic device within a Whispering Gallery Mode (WGM) microresonator, allowing for the facile exchange of chemical reagents within the resonator’s interior while maintaining a solution-free environment on its exterior. We first leverage these qualities to investigate the photo-activated etching of single gold nanorods by ferric chloride, providing a new method for rapid acquisition of spatial and morphological information about nanoparticles as they undergo chemical reactions. We then demonstrate the ability to control nanorod orientation within a microbubble through optically exerted torque, a new route toward the construction of hybrid photonic-plasmonic systems. Critically, the reported platform advances microresonator spectrometer technology by permitting room-temperature, aqueous experimental conditions, opening a regime of time-resolved single-particle experiments on non-emissive, nanoscale analytes engaged in catalytically and biologically relevant chemical dynamics.</p><p></p><p></p>

Toward Real-Time Monitoring and Control of Nanoparticle Properties with a Microbubble Resonator Spectrometer

2019 ◽  
Author(s):  
Levi Hogan ◽  
Erik Horak ◽  
Jonathan Ward ◽  
Kassandra Knapper ◽  
Síle Nic Chormaic ◽  
...  
Keyword(s):  
Thermal Relaxation ◽  
New Method ◽  
Monitoring And Control ◽  
Experimental Conditions ◽  
Widespread Application ◽  
Time Resolved ◽  
Optical Microresonators ◽  
Rapid Acquisition ◽  
Visible Wavelengths ◽  
Free Environment

<p>Optical microresonators are finding widespread application at the frontiers of nanophotonic technology, driven by virtue of their ability to confine light to the nanoscale and enhance light-matter interactions. Recently, our group has developed a new method of photothermal absorption spectroscopy, whereby toroidal optical microresonators act as microscale thermometers to detect the thermal relaxation of optically pumped, nanoscopic analytes. However, translation of this technology to chemically dynamic systems requires a platform that is mechanically stable, amenable to solution, and visibly transparent. We here report microbubble absorption spectrometers as a new and exciting platform that meets these requirements. Microbubbles integrate a two-port microfluidic within a Whispering Gallery Mode (WGM) microresonator, allowing for the facile exchange of chemical reagents within the resonator’s interior while maintaining a solution-free environment on its exterior. Furthermore, their all-glass fabrication results in an ultra-low photothermal background at visible wavelengths. We first leverage these virtues to investigate the photo-activated etching of single gold nanorods by ferric chloride, providing a new method for rapid acquisition of spatial and morphological information about nanoparticles as they undergo chemical reactions. We then demonstrate the ability to control nanorod orientation within a microbubble through optically exerted torque, indicating new routes forward towards the controlled construction of hybrid photonic-plasmonic systems. Critically, the reported platform advances microresonator technology by permitting room-temperature, aqueous experimental conditions, ushering the possibility of time-resolved experiments on non-emissive, nanoscale analytes engaged in catalytically and biologically relevant chemical dynamics.</p>

scholarly journals A quantitative nanoparticle extraction method for microsecond time resolved single-particle ICP-MS data in the presence of a high background

2019 ◽  
Vol 34 (8) ◽  
pp. 1571-1580 ◽  
Author(s):  
Darya Mozhayeva ◽  
Carsten Engelhard
Keyword(s):  
Time Resolution ◽  
Single Particle ◽  
Extraction Method ◽  
New Method ◽  
Time Resolved ◽  
High Background ◽  
Icp Ms ◽  
Dissolved Ions

A new method for the quantification of dissolved ions and nanoparticles in mixtures with SP-ICP-MS with microsecond time resolution.

Electron-beam damage of oxides at high current densities

1989 ◽  
Vol 47 ◽  
pp. 634-635
Author(s):  
M. R. McCartney ◽  
J. K. Weiss ◽  
David J. Smith
Keyword(s):  
Electron Beam ◽  
Electron Microscope ◽  
Current Density ◽  
Transition Metal Oxides ◽  
Time Resolved ◽  
Rapid Acquisition ◽  
Resolution Electron ◽  
Current Densities ◽  
Electron Stimulated Desorption ◽  
Channel Analyzer

It is well-known that electron-beam irradiation within the electron microscope can induce a variety of surface reactions. In the particular case of maximally-valent transition-metal oxides (TMO), which are susceptible to electron-stimulated desorption (ESD) of oxygen, it is apparent that the final reduced product depends, amongst other things, upon the ionicity of the original oxide, the energy and current density of the incident electrons, and the residual microscope vacuum. For example, when TMO are irradiated in a high-resolution electron microscope (HREM) at current densities of 5-50 A/cm2, epitaxial layers of the monoxide phase are found. In contrast, when these oxides are exposed to the extreme current density probe of an EM equipped with a field emission gun (FEG), the irradiated area has been reported to develop either holes or regions almost completely depleted of oxygen. ’ In this paper, we describe the responses of three TMO (WO3, V2O5 and TiO2) when irradiated by the focussed probe of a Philips 400ST FEG TEM, also equipped with a Gatan 666 Parallel Electron Energy Loss Spectrometer (P-EELS). The multi-channel analyzer of the spectrometer was modified to take advantage of the extremely rapid acquisition capabilities of the P-EELS to obtain time-resolved spectra of the oxides during the irradiation period. After irradiation, the specimens were immediately removed to a JEM-4000EX HREM for imaging of the damaged regions.

Technical note: A new method for the evaluation of puff dispersion field experiments for the validation of time-resolved dispersion simulations

2019 ◽  
Vol 210 ◽  
pp. 171-176
Author(s):  
Thorsten Wittemeier ◽  
Timothy G. Foat ◽  
Steven Herring ◽  
John S. Shrimpton ◽  
Zheng-Tong Xie
Keyword(s):  
Field Experiments ◽  
Technical Note ◽  
New Method ◽  
Time Resolved

MASS AND LIFETIME MEASUREMENTS AT THE PRESENT ESR FACILITY

2009 ◽  
Vol 18 (02) ◽  
pp. 323-334 ◽  
Author(s):  
YURI A. LITVINOV
Keyword(s):  
Mass Spectrometry ◽  
Single Particle ◽  
Experimental Methods ◽  
Lifetime Measurements ◽  
Time Resolved ◽  
Particle Decay ◽  
Decay Properties ◽  
Decay Spectroscopy ◽  
Beta Decays ◽  
Charged Ions

Mass and lifetime measurements of stored exotic nuclei is one of the successful experimental programs at the FRS-ESR facility of GSI, Darmstadt. Two experimental techniques, namely Isochronous and time-resolved Schottky mass spectrometry have been developed. Nuclides in a very broad range of half-lives starting from stable down to only a few ten microseconds can be addressed. Single stored ions can be measured which makes these techniques highly efficient. More than 1100 atomic masses have been measured meanwhile. Half-life measurements are performed with bare and few-electron ions. Decay properties of such highly-charged ions can be dramatically different from the ones known in neutral atoms. Single-particle decay spectroscopy has been developed for investigations of two-body beta decays. A brief description of the experimental methods and recent results will be presented. Future experiments at the present facility and the perspectives with the new NuSTAR/ILIMA project at FAIR will be outlined.

A COMPARISON OF BIODISTRIBUTION OF LIPOSOMAL AND SOLUBLE IL-2 BY A NEW METHOD BASED ON TIME-RESOLVED FLUOROMETRY OF EUROPIUM

Cytokine ◽  
2000 ◽  
Vol 12 (11) ◽  
pp. 1702-1711 ◽  
Author(s):  
Mary E Neville ◽  
Kurt W Richau ◽  
Lawrence T Boni ◽  
Laura E Pflug ◽  
Richard J Robb ◽  
...  
Keyword(s):  
New Method ◽  
Time Resolved

scholarly journals Development, Characterization, and Application of a Versatile Single Particle Detection Apparatus for Time-Integrated and Time-Resolved Fluorescence Measurements—Part II: Experimental Evaluation

2009 ◽  
Vol 2009 ◽  
pp. 1-14
Author(s):  
Xihong Wu ◽  
J. A. Merten ◽  
N. Omenetto ◽  
B. W. Smith ◽  
J. D. Winefordner
Keyword(s):  
Single Particle ◽  
Narrow Beam ◽  
Time Resolved Fluorescence ◽  
Particle Detection ◽  
Time Resolved ◽  
Endogenous Fluorophores ◽  
Fluorescence Measurements ◽  
On Line ◽  
Single Particle Detection ◽  
Speed Mode

This paper describes the experimental realization and characterization of a versatile single particle detection apparatus. The system utilizes a novel particle beam inlet that can serve as either an on-line particle concentrator (i.e., all diameters confined in a narrow beam) or as a segregator (i.e., selected diameters confined in a narrow beam) and can be operated in a high-speed mode as well as in a low-speed mode, thus allowing different interaction times between the particles and the laser beam. An aerodynamic sizing technique has been incorporated into the system to provide rapid, real-time, and high-resolution sizing. Parameters such as transmission efficiency and size-segregation efficiency have been measured. The performance of the instrument has been demonstrated by on-line detection of spectrally resolved and time resolved fluorescence detection from airborne dye-doped particles and aerosolized endogenous fluorophores found in biological agents.

A Comparison of Segment Retention Criteria for Finite Mixture Logit Models

2003 ◽  
Vol 40 (2) ◽  
pp. 235-243 ◽  
Author(s):  
Rick L. Andrews ◽  
Imran S. Currim
Keyword(s):  
Information Criterion ◽  
Finite Mixture ◽  
Choice Data ◽  
Akaike's Information Criterion ◽  
Experimental Conditions ◽  
Widespread Application ◽  
Akaike’S Information Criterion ◽  
True Number ◽  
Penalty Factor ◽  
Number Of Segments

Despite the widespread application of finite mixture models in marketing research, the decision of how many segments to retain in the models is an important unresolved issue. Almost all applications of the models in marketing rely on segment retention criteria such as Akaike's information criterion, Bayesian information criterion, consistent Akaike's information criterion, and information complexity to determine the number of latent segments to retain. Because these applications employ real-world data in which the true number of segments is unknown, it is not clear whether these criteria are effective. Retaining the true number of segments is crucial because many product design and marketing decisions depend on it. The purpose of this extensive simulation study is to determine how well commonly used segment retention criteria perform in the context of simulated multinomial choice data, as obtained from supermarket scanner panels, in which the true number of segments is known. The authors find that an Akaike's information criterion with a penalty factor of three rather than the traditional value of two has the highest segment retention success rate across nearly all experimental conditions. Currently, this criterion is rarely, if ever, applied in the marketing literature. Experimental factors of particular interest in marketing contexts, such as the number of choices per household, the number of choice alternatives, the error variance of the choices, and the minimum segment size, have not been considered in the statistics literature. The authors show that they, among other factors, affect the performance of segment retention criteria.

Operational Performance and Locally Resolved Outflow of Brush Seals

2019 ◽  
Author(s):  
Fabian Schur ◽  
Jens Friedrichs
Keyword(s):  
Operational Performance ◽  
Design Parameters ◽  
Steam Turbines ◽  
Test Rig ◽  
Rotating Shaft ◽  
Experimental Conditions ◽  
Widespread Application ◽  
Backing Plate ◽  
Brush Seals ◽  
The Impact

Abstract As a result of the superior leakage efficiency of brush seals compared to conventional labyrinth seals, compliant contacting filament seals are used to increase the efficiency of jet engines as well as stationary gas and steam turbines. The widespread application of brush seals at different and varying pressure differences combined with variable contacting velocities at the rotor surface requires a profound understanding of the influences of different design parameters on the operational leakage performance. In order to systematically investigate the impact of different design parameters on sealing performance, a new cold air test rig was developed. The new test rig with rotating shaft enables hot-wire anemometry measurements downstream of the seals. These measurements provide insight into the locally resolved flow structure in addition to the integral leakage measurements. For the investigations, one welded and five different clamped brush seals at rotational speeds up to 3000rpm and pressure differences across the seals up to 500kPa are considered. Therefore, the influence of two different designs on the flow through the bristles is presented. For the clamped brush seals, variations of the front and backing plate are investigated. Additionally, the effects of bristle diameter and three different axial inclinations of the bristle pack on the sealing efficiency are shown. Furthermore, initial wear development during the first 30 to 60 hours of brush seal operation at varying experimental conditions is presented and linked to the design parameters. Consequently, the effects of major design aspects on the operational performance of brush seals are examined and presented.

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