606 research outputs found
Synthesis and Characterization of Hydrous Ruthenium Oxide-Carbon Supercapacitors
It is shown that composite Ru oxide-carbon based supercapacitors possess superior energy and power densities as compared to bare carbon. An electroless deposition process was used to synthesize the ruthenium oxide-carbon composites. Ru is dispersed on the carbon matrix as small particles. The effect of electrochemical oxidation and temperature treatment on the material performance has been studied extensively. Increasing the oxidation temperature reduces the proton transport rate and also increases the degree of crystallinity of the deposits. This adversely affects the performance of the composite. Loading a small amount of Ru oxide (9 wt %) on carbon increases the capacitance from 98 to 190 F/g
Enhanced magnetic properties of polymer-magnetic nanostructures synthesized by ultrasonication
Polymer based nickel (Ni) and cobalt (Co) co-doped ferrites were prepared by adept ultrasonication route. Different concentrations of polymer [polyvinyl alcohol (PVA)] (0.2 g and 0.5 g) was added as a surfactant to the magnetic particles. The phase purity of Ni-Co ferrites (spinel structure) was confirmed by X-ray diffraction (XRD). Enhanced saturation magnetization of polymer based magnetic nanoparticles due to shape anisotropy and size. 0.2 wt% doped ferrite showed superparamagnetic characteristics with blocking temperature above room temperature. Hence, ultrasonication route is a rapid and effective technique for tailoring size and morphology of magnetic nanostructure that could be useful in magnetic-sensor applications
Transition metal titanium (Ti) doped LaFeO3 nanoparticles for enhanced optical structural and magnetic properties
A series of LaFe1−xTixO3 (x = 0.0, 0.2, 0.4, 0.6 and 0.8) nanoparticles have been successfully synthesized by simple co-precipitation technique. The synthesized samples (calcined at 800° C/3hr) were characterised for structural, optical and magnetic properties. Structural phase formation of the crystal shows orthorhombic planes of these samples phases. The average crystallite size (Dc) is decreasing with a dopant and found to be varying between ∼ 9 and 25 nm. Tailored surface morphology was analyzed using scanning electron microscope (FESEM) and transmission electron microscopes (TEM) with selected area electron diffraction pattern (SAED) also confirms the evolution of orthorhombic phases. Diffuse reflectance spectra (DRS) are recorded to evaluate the variation of optical band gap (Eg) upon titanium doping into the LaFeO3 system. The obtained results attributed that Eg values are increasing with dopant altering between 2.05 and 2.61 eV. The metal oxide (M - O) stretching vibrations and few functional groups are detected from infrared spectra (IR). The weak ferromagnetic behaviour is observed from hysteresis loop behaviour. Additionally, the large hysteresis loop behaviour induces no saturation up to 15 kOe in nanoparticles coercivity (Hc) and anisotropy constants (K1) are eventually decreasing with ‘x’ values
Bootstrapping Conversational Agents With Weak Supervision
Many conversational agents in the market today follow a standard bot
development framework which requires training intent classifiers to recognize
user input. The need to create a proper set of training examples is often the
bottleneck in the development process. In many occasions agent developers have
access to historical chat logs that can provide a good quantity as well as
coverage of training examples. However, the cost of labeling them with tens to
hundreds of intents often prohibits taking full advantage of these chat logs.
In this paper, we present a framework called \textit{search, label, and
propagate} (SLP) for bootstrapping intents from existing chat logs using weak
supervision. The framework reduces hours to days of labeling effort down to
minutes of work by using a search engine to find examples, then relies on a
data programming approach to automatically expand the labels. We report on a
user study that shows positive user feedback for this new approach to build
conversational agents, and demonstrates the effectiveness of using data
programming for auto-labeling. While the system is developed for training
conversational agents, the framework has broader application in significantly
reducing labeling effort for training text classifiers.Comment: 6 pages, 3 figures, 1 table, Accepted for publication in IAAI 201
Meta-analysis of Inter-species Liver Co-expression Networks Elucidates Traits Associated with Common Human Diseases
Co-expression networks are routinely used to study human diseases like obesity and diabetes. Systematic comparison of these networks between species has the potential to elucidate common mechanisms that are conserved between human and rodent species, as well as those that are species-specific characterizing evolutionary plasticity. We developed a semi-parametric meta-analysis approach for combining gene-gene co-expression relationships across expression profile datasets from multiple species. The simulation results showed that the semi-parametric method is robust against noise. When applied to human, mouse, and rat liver co-expression networks, our method out-performed existing methods in identifying gene pairs with coherent biological functions. We identified a network conserved across species that highlighted cell-cell signaling, cell-adhesion and sterol biosynthesis as main biological processes represented in genome-wide association study candidate gene sets for blood lipid levels. We further developed a heterogeneity statistic to test for network differences among multiple datasets, and demonstrated that genes with species-specific interactions tend to be under positive selection throughout evolution. Finally, we identified a human-specific sub-network regulated by RXRG, which has been validated to play a different role in hyperlipidemia and Type 2 diabetes between human and mouse. Taken together, our approach represents a novel step forward in integrating gene co-expression networks from multiple large scale datasets to leverage not only common information but also differences that are dataset-specific
Functionally important segments in proteins dissected using Gene Ontology and geometric clustering of peptide fragments
A geometric clustering algorithm has been developed to dissect protein fragments based on their relevance to function
Growth of large-sized relaxor ferroelectric PZN-PT single crystals by modified flux growth method
A novel bottom-cooling high-temperature solution growth technique is
developed for growing large-sized relaxor ferroelectric
0.91Pb(Zn1/3Nb2/3O3)-0.09PbTiO3 (PZN-PT) single crystals. During the growth, an
inverse temperature gradient is maintained in the crucible base by flowing air
at a controlled rate. This method restricts the number of spontaneously
nucleated crystals at crucible bottom, reduces loss of volatile PbO component
and favours the growth of large-sized PZN-PT single crystals. Large-sized
PZN-PT single crystals of dimensions ~ 22x20x14 mm3 are reproducibly grown by
the proposed method. The electrical characteristics of the PZN-PT wafers
oriented along the , and directions are investigated. PZN-PT
wafers oriented along the direction exhibited superior piezoelectric
coefficient (d33) of ~ 2221 pm/V. The homogeneity of the physical parameters is
analysed by preparing 10 elements with dimensions of ~5x2.5x2.5 mm3 which were
cut from single wafer oriented along the direction. The ferro-, piezo-
and dielectric characteristics of these wafers were found to be highly uniform
with small standard deviation. The observation of d33 value with less than 2 %
deviation from mean value confirms the growth of high quality PZN-PT single
crystals.Comment: 16 pages, 7 figure
Decoherence effects in quantum nondemolition measurement induced entanglement between Bose-Einstein condensates
We study the robustness of quantum nondemolition (QND) measurement-induced
entanglement between Bose-Einstein Condensates (BECs). We consider an
experimental scheme where two BECs are placed in the paths of a Mach-Zehnder
interferometer, and a QND interaction creates entanglement between coherent
light and the atoms. We analyze the two dominant channels of decoherence,
atomic dephasing and photon loss on the entangled states produced by this
scheme. We calculate the effect of dephasing on the variance and expectation
values of the spin operators, entanglement, and correlation criteria. Our
analysis does not use the Holstein-Primakoff approximation and is capable of
modeling long light-atom interaction times, producing non-Gaussian states
beyond the two-mode squeezed states. In the presence of dephasing, the
entangled states are robust in the macroscopic limit as long as the
dimensionless interaction time is less than , where is the
number of atoms in the BEC. For photon loss, the entangled states generated by
long interaction times show remarkable robustness that makes the scheme
promising for various quantum information applications
Age at Onset Influences Progression of Motor and Non-Motor Symptoms during the Early Stage of Parkinson’s Disease: A Monocentric Retrospective Study
The interactions between the age at onset with other pathogenic mechanisms and the interplays between the disease progression and the aging processes in Parkinson’s disease (PD) remain undefined, particularly during the first years of illness. Here, we retrospectively investigated the clinical presentation and evolution of the motor and non-motor symptoms and treatment-related complications during the first 5 years of illness in subjects categorized according to age at onset. A total of 131 subjects were divided into “Early-Onset-PD” (EOPD; onset ≤49 years), “Middle-Onset-PD” (MOPD; onset 50–69 years) and “Late-Onset-PD” (LOPD; onset ≥70 years). The T0 visit was set at the time of the clinical diagnosis; the T1 visit was 5 years (±5 months) later. At T0, there were no significant differences in the motor features among the groups. At T1, the LOPD patients displayed a significantly higher frequency of gait disturbances and a higher frequency of postural instability. Moreover, at T1, the LOPD subjects reported a significantly higher frequency of non-motor symptoms; in particular, cardiovascular, cognitive and neuropsychiatric domains. The presented results showed a significantly different progression of motor and non-motor symptoms in the early course of PD according to the age at onset. These findings contribute to the definition of the role of age at onset on disease progression and may be useful for the pharmacological and non-pharmacological management of PD
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