2,898 research outputs found
Ni-dispersed fullerenes: Hydrogen storage and desorption properties
Our study shows that the H2 storage media using Ni-dispersed fullerenes could be viable alternatives to reversible hydrogen storage. It is demonstrated that a single Ni coated on the fullerene surface can store up to three H2 molecules. Consequently, at high Ni coverage, Ni-dispersed fullerenes are considered to be the novel hydrogen storage media capable of storing ~6.8 wt % H2, thus exceeding the Department of Energy target (6.5 wt %) for automobile applications. Moreover, the H2 desorption activation barrier of 11.8 kcal/mol H2 is ideal for many practical hydrogen storage applications
Left dominance of EEG abnormalities in patients with transient global amnesia
AbstractPurposeTransient global amnesia (TGA) is a syndrome of unknown etiology. Electroencephalographic (EEG) abnormalities in TGA have been reported previously. We analyzed the frequency and characteristics of EEG abnormalities in patients with TGA.MethodsWe collected EEGs of patients with a clinical diagnosis of TGA who had visited the emergency room or the outpatient clinic over a period of 8 years and compared clinical and demographic characteristics of the patients with normal EEGs with those with abnormal EEGs.ResultsEEG abnormalities were found in 35 (22.9%) out of 153 patients and epileptiform discharges were seen in 26 (74.3%) out of these 35 patients. Spikes or sharp waves were detected on the left side only (48.6%) or on both sides (25.7%), but none of the patients showed spikes or sharp waves on right side only. In six patients the EEG had normalized within three months of presentation, in ten within six months, and in twelve by one year. The EEG remained abnormal in eleven out of the 23 patients one year after presentation.ConclusionIn this largest consecutive EEG study at one center, the proportion of patients with TGA in whom epileptiform discharges were demonstrated within days of the episode of TGA was significantly higher than in the previous literature. EEG abnormalities such as spikes or sharp waves spontaneously disappeared in almost half of cases over one-year of follow-up. There was a clear left dominance of EEG abnormalities in patients with TGA
Tyrosinase-Immobilized Biosensor Based on the Functionalized Hydroxyl Group-MWNT and Detection of Phenolic Compounds in Red Wines
The tyrosinase-immobilized biosensor was developed with the hydroxyl group-functionalized multiwall carbon nanotube (MWNT) for phenol detection. The hydroxyl group-modified MWNT was modified to include poly(GVPB)-g-MWNT, or poly(HEMA), by a radiation-induced graft polymerization of glucosyl 4-vinylphenylboronate (GVPB) or 2-hydroxyethyl methacrylate (HEMA) on the surface of MWNT. The response of biosensor was in the range of 0.6–7.0 mM for concentration and in the range of 0.05–0.35 mM for phenol in a phosphate buffer solution, respectively. Various parameters influencing biosensor performance have been optimized: for pH, temperature, and the response to various phenolic compounds. The biosensor was then tested on phenolic compounds contained in three different commercial red wines
Increasing the Durability of Piezoelectric Impact-based Micro Wind Generator in Real Application
AbstractThe purpose of this study is to increase the durability of piezoelectric impact-based micro wind generator (PIMWG) in real application. Using new PIMWG design, numerical simulation, and experimental comparison analysis, we improved the durability of PIMWGs in real application. The experimental results show that the optimized PIMWG generated 2.4 mW (RMS value), and it did not crack within 40h. In this study, we improved the durability of PIMWGs for real application
Trend analysis of prosthodontic treatment modality between 2005 and 2008 in Seoul National University Dental Hospital
Joint Channel Estimation and Phase Noise Suppression for OFDM Systems
The joint channel estimation and phase noise
suppression scheme for orthogonal frequency-division
multiplexing (OFDM) systems is proposed for a case where
channel estimation is needed symbol by symbol. In the proposed
scheme, channel estimation and phase noise suppression are
performed iteratively via the expectation-maximization (EM)
algorithm. The proposed algorithm mitigates the performance
degradation due to phase noise effectively while providing the
accurate channel estimate with comparatively few pilot
subcarriers so that the spectral efficiency of an OFDM system is
improved
On the relation between duration and energy of non-repeating fast radio bursts: census with the CHIME data
A correlation between the intrinsic energy and the burst duration of
non-repeating fast radio bursts (FRBs) has been reported. If it exists, the
correlation can be used to estimate intrinsic energy from the duration, and
thus can provide us with a new distance measure for cosmology. However, the
correlation suffered from small number statistics (68 FRBs) and was not free
from contamination by latent repeating populations, which might not have such a
correlation. How to separate/exclude the repeating bursts from the mixture of
all different types of FRBs is essential to see this property. Using a much
larger sample from the new FRB catalogue (containing 536 FRBs) recently
released by the CHIME/FRB project, combined with a new classification method
developed based on unsupervised machine learning, we carried out further
scrutiny of the relation. We found that there is a weak correlation between the
intrinsic energy and duration for non-repeating FRBs at z < 0.3 with Kendall's
tau correlation coefficient of 0.239 and significance of 0.001 (statistically
significant), whose slope looks similar to that of gamma-ray bursts. This
correlation becomes weaker and insignificant at higher redshifts (z > 0.3),
possibly due to the lack of the faint FRBs at high-z and/or the redshift
evolution of the correlation. The scattering time in the CHIME/FRB catalogue
shows an intriguing trend: it varies along the line obtained from linear fit on
the energy versus duration plane between these two parameters. A possible
cosmological application of the relation must wait for faint FRBs at high-z.Comment: 9 pages, 7 figures, accepted for publication in MNRA
Successful Treatment of Stereotactic Body Radiation Therapy Combined with Transarterial Chemolipiodolization for Hepatocellular Carcinoma with Biliary Obstruction
Conventional radiation therapy (RT) is a widely recognized treatment for hepatocellular carcinoma (HCC). However, conventional RT plays only a limited role in HCC treatment because of its low efficacy and the low tolerance of the liver for this modality. Stereotactic body radiation therapy (SBRT) was recently developed and represents the most advanced radiation therapy technique currently available. It can deliver a high dose in a short time to well-defined hepatic tumors, with rapid dose fall-off gradients. We believe that SBRT with transarterial chemolipiodolization (TACL) may prove promising as a combined treatment modality for HCC due to its precision and relative safety. Here we present a case of successful treatment of advanced HCC with obstructive jaundice using this combined modality
Machine Learning Classification of Repeating FRBs from FRB121102
Fast Radio Bursts (FRBs) are mysterious bursts in the millisecond timescale
at radio wavelengths. Currently, there is little understanding about the
classification of repeating FRBs, based on difference in physics, which is of
great importance in understanding their origin. Recent works from the
literature focus on using specific parameters to classify FRBs to draw
inferences on the possible physical mechanisms or properties of these FRB
subtypes. In this study, we use publicly available 1652 repeating FRBs from
FRB121102 detected with the Five-hundred-meter Aperture Spherical Telescope
(FAST), and studied them with an unsupervised machine learning model. By
fine-tuning the hyperparameters of the model, we found that there is an
indication for four clusters from the bursts of FRB121102 instead of the two
clusters ("Classical" and "Atypical") suggested in the literature. Wherein, the
"Atypical" cluster can be further classified into three sub-clusters with
distinct characteristics. Our findings show that the clustering result we
obtained is more comprehensive not only because our study produced results
which are consistent with those in the literature but also because our work
uses more physical parameters to create these clusters. Overall, our methods
and analyses produced a more holistic approach in clustering the repeating FRBs
of FRB121102.Comment: 24 pages, 14 figure
DNA/RNA chimera templates improve the emission intensity and target the accessibility of silver nanocluster-based sensors for human microRNA detection
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