2,657 research outputs found
Full-Field Swept Source Master-Slave Optical Coherence Tomography
We apply the principle of master-slave (MS) interferometry to a full-field swept source optical coherence tomography (OCT) setup equipped with a fast 2-D camera. MS interferometry does not involve Fourier transformations and, therefore, eliminates the need for spectrum data resampling required by the conventional spectral domain OCT. Using this method in a full-field OCT setup, en face images are acquired in vivo from finger skin, Drosophila melanogaster larvae, and pupae, with no spectrum resampling and no mechanical scanning. The signal processing is based on a comparison operation of the shapes of channeled spectra for each camera pixel, with a set of reference signals (masks). In this way, en face OCT images can be obtained with no need for the volumetric assembly and software cutting the en face images from an image volume, which are required by the conventional spectral domain OCT method. We demonstrate that the sensitivity and axial resolution of the MS method in a full-field swept source OCT setup are similar to the values obtained using the conventional Fourier-transformation-based swept source OCT method in a full-field setup. Multiple en face images can be produced in parallel by using multiple stored shapes of channeled spectra for the depths of interest. The full-field MS-OCT method presented here opens the possibility of parallel processing for all image points in a 3-D volume of the object
An Integrated Physiological Model of the Lung Mechanics and Gas Exchange Using Electrical Impedance Tomography in the Analysis of Ventilation Strategies in ARDS Patients
Mouloud Denai, M. Mahfouf, A. Wang, D. A. Linkens, and G. H. Mills, 'An Integrated Physiological Model of the Lung Mechanics and Gas Exchange Using Electrical Impedance Tomography in the Analysis of Ventilation Strategies in ARDS Patients'. Paper presented at the 3rd International Joint Conference on Biomedical Engineering Systems and Technologies (BIOSTEC 2010), 20 - 23 January 2010, Valencia, Spain.Peer reviewedFinal Published versio
Hopping Conduction in Disordered Carbon Nanotubes
We report electrical transport measurements on individual disordered carbon
nanotubes, grown catalytically in a nanoporous anodic aluminum oxide template.
In both as-grown and annealed types of nanotubes, the low-field conductance
shows as exp[-(T_{0}/T)^{1/2}] dependence on temperature T, suggesting that
hopping conduction is the dominant transport mechanism, albeit with different
disorder-related coefficients T_{0}. The field dependence of low-temperature
conductance behaves an exp[-(xi_{0}/xi)^{1/2}] with high electric field xi at
sufficiently low T. Finally, both annealed and unannealed nanotubes exhibit
weak positive magnetoresistance at low T = 1.7 K. Comparison with theory
indicates that our data are best explained by Coulomb-gap variable range
hopping conduction and permits the extraction of disorder-dependent
localization length and dielectric constant.Comment: 10 pages, 5 figure
Novel annular flow electromagnetic measurement system for drilling engineering
Downhole micro-flux control drilling technology can effectively solve drilling accidents, such as kick and loss in narrow density window drilling scenarios. Using a downhole annular flow measurement system to obtain real-time information of downhole annular flow is the core and foundation of downhole micro-flux control drilling technology. The research work of electromagnetic flowmeters in recent years creates a challenge for downhole annular flow measurement. This paper proposes a new method for an annular flow measurement system based on the electromagnetic induction principle. First, the annular flow measuring principle, the weight function, the density of virtual current, and the magnetic field of the annular flow electromagnetic measurement system are described. Second, the basic design of the annular flow electromagnetic measurement system is described. Third, model simulation and dynamic experiments on an annular flow electromagnetic measurement system are carried out. The simulation and experimental results show a linear relationship between the system output and the annular flow rate, and also verify the correctness of annular flow electromagnetic measurement theory
3D porous Li3V2(PO4)3/hard carbon composites for improving the rate performance of lithium ion batteries
A 3D porous Li3V2(PO4)3/hard carbon composite delivers a capacity of 98 mA h gâ1 after 1000 cycles at 10C.</p
Photo-electrochemical Hydrogen Sulfide Splitting using SnIV-doped Hematite Photo-anodes
© 2016 The Authors. Published by Elsevier B.V.Spray-pyrolysed SnIV-doped α-Fe2O3 photo-anodes were used for photo-assisted splitting of HS- ions in alkaline aqueous solutions, producing polysulfide (Sn2 -) ions together with hydrogen at the cathode. Subsequent aerial oxidation of polysulfide could be used to produce elemental sulfur. At an applied electrode potential of 1.07 V (RHE) and an irradiance of 5.6 kW m- 2, stable photocurrents of ca. 11 A m- 2 (2 à 10- 3 A W- 1) were recorded over 75 h, polysulfide concentrations increasing linearly with time. Despite being predicted thermodynamically to form iron sulfide(s) in sulfide solutions, such photo-anodes appeared to be stable. In comparison with conventional water splitting under alkaline conditions, the coupled processes of hydrogen sulfide ion oxidation and water reduction had a lower energy requirement
Techniques of replica symmetry breaking and the storage problem of the McCulloch-Pitts neuron
In this article the framework for Parisi's spontaneous replica symmetry
breaking is reviewed, and subsequently applied to the example of the
statistical mechanical description of the storage properties of a
McCulloch-Pitts neuron. The technical details are reviewed extensively, with
regard to the wide range of systems where the method may be applied. Parisi's
partial differential equation and related differential equations are discussed,
and a Green function technique introduced for the calculation of replica
averages, the key to determining the averages of physical quantities. The
ensuing graph rules involve only tree graphs, as appropriate for a
mean-field-like model. The lowest order Ward-Takahashi identity is recovered
analytically and is shown to lead to the Goldstone modes in continuous replica
symmetry breaking phases. The need for a replica symmetry breaking theory in
the storage problem of the neuron has arisen due to the thermodynamical
instability of formerly given solutions. Variational forms for the neuron's
free energy are derived in terms of the order parameter function x(q), for
different prior distribution of synapses. Analytically in the high temperature
limit and numerically in generic cases various phases are identified, among
them one similar to the Parisi phase in the Sherrington-Kirkpatrick model.
Extensive quantities like the error per pattern change slightly with respect to
the known unstable solutions, but there is a significant difference in the
distribution of non-extensive quantities like the synaptic overlaps and the
pattern storage stability parameter. A simulation result is also reviewed and
compared to the prediction of the theory.Comment: 103 Latex pages (with REVTeX 3.0), including 15 figures (ps, epsi,
eepic), accepted for Physics Report
Graphene-like carbon sheet/Fe3O4 nanocomposites derived from soda papermaking black liquor for high performance lithium ion batteries
Alkali lignins and its degradation products in the soda papermaking black liquor (SPBL) are renewable resource with the highest natural carbon content. In this work we convert SPBL into the high-performance carbon-based nanocomposite anodes. The unique functional groups of lignin biomass induce spontaneous formation of graphene-like carbon sheet (GCS) in-situ doped SiC/S. The lamellar GCS/FeO nanocomposite (GCS/FO-NC) is facilely prepared via one-step in-situ thermo-chemical method at 700\ua0°C, in which donut shaped FeO nanoparticles with superlattices and inner surface are homogeneously embedded in the interlayer of GCS and are also anchored on its surface. The GCS/FO-NC anode exhibits a ultrahigh first discharge specific capacity of 3829\ua0mAh\ua0g at 50\ua0mA\ua0g in a coin-type Li ion battery, which is more than 4 times the theoretical capacity (924\ua0mAh\ua0g) of FeO and 5 times that of the graphene anode (744\ua0mAh. g). Even at a high current density (1000\ua0mA\ua0g), it still exhibits a high reversible capacity (750\ua0mAh\ua0g) after 1400 discharge/charge cycles. More importantly, the removal efficiency of chemical oxygen demand of SPBL is up to 83.4% during the synthesis process, which reduce its load to environment and synthetic cost of carbon-based nanocomposite anodes
Nucleon-nucleon momentum correlation function for light nuclei
Nucleon-nucleon momentum correlation function have been presented for nuclear
reactions with neutron-rich or proton-rich projectiles using a nuclear
transport theory, namely Isospin-Dependent Quantum Molecular Dynamics model.
The relationship between the binding energy of projectiles and the strength of
proton-neutron correlation function at small relative momentum has been
explored, while proton-proton correlation function shows its sensitivity to the
proton density distribution. Those results show that nucleon-nucleon
correlation function is useful to reflect some features of the neutron- or
proton-halo nuclei and therefore provide a potential tool for the studies of
radioactive beam physics.Comment: Talk given at the 18th International IUPAP Conference on Few-Body
Problems in Physics (FB18), Santos, Brasil, August 21-26, 2006. To appear in
Nucl. Phys.
PENGGUNAAN BAHAN AJAR DALAM PEMBELAJARAN IPS SMP BERBASIS KONTEKSTUAL PADA SISWA KELAS VII SMP NEGERI 1 PURWANTORO WONOGIRI
This research aim: 1. Describe how teacher use the teaching material in
Social Subject in Junior High School 1 Purwantoro up until now. 2.
Describe the constraint and how to overcome it. 3. Describe the usage
result of the teaching material in study of Social for Junior High School
in Purwantoro 1 Junior High School.
This research takes place in Purwantoro 1 Junior High School, Wonogiri
Regency. This research metod is descriptive research of qualitative. This
research wants to describe and expose the usage of teaching material in
study of Contextual Based Social for Junior High School in Purwantoro
1 Junior High School according to the condition and the situation at the
moment.
Strategies utilized in this research are interviewing, question airing,
observing, and documenting.
The result of this research concludes that teaching material in Study of
Contextual Based Social for Junior High School in Purwantoro 1 Junior
High School, evaluated from its form covered : a). Printed teaching
material consist. b). Heard Teaching Material (audio) consist. c) Visual
and Listening Teaching Material consist. d). Interactive teaching
material like compact disc (doesnât yet able to be executed) e).
Environment teaching material (geography, history, and economics) still
applied in class theory level.
Current result achieved from the use of teaching materials in learning
of Social for Junior High School in Purwantoro Junior High School are:
1) Provide better learning environment for teachers and students. 2)
Help students and make them easy to learn Social. 3) Improve studentâs
learning achievement proved with 79,895 average score (it exceeds
current KKM set by the teachers: 72)
Keywords : The Use of, Teaching Materials of Contextual Based Social
for Junior High School
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