3,058 research outputs found
Electric field control of nonvolatile four-state magnetization at room temperature
We find the realization of large converse magnetoelectric (ME) effects at
room temperature in a multiferroic hexaferrite
BaSrCoFeO single crystal, in which rapid
change of electric polarization in low magnetic fields (about 5 mT) is coined
to a large ME susceptibility of 3200 ps/m. The modulation of magnetization then
reaches up to 0.62 /f.u. in an electric field of 1.14 MV/m. We find
further that four ME states induced by different ME poling exhibit unique,
nonvolatile magnetization versus electric field curves, which can be
approximately described by an effective free energy with a distinct set of ME
coefficients
Hybrid XML Data Model Architecture for Efficient Document Management
XML has been known as a document standard in representation and exchange of data on the Internet, and is also used as a standard language for the search and reuse of scattered documents on the Internet. The issues related to XML are how to model data on effective and efficient management of semi-structured data and how to actually store the modeled data when implementing a XML contents management system. Previous researches on XML have limitations in (1) reproduction of XML documents from the stored data, (2) retrieval of XML sub-graph from search, (3) supporting only top-down search, not full-search, and (4) dependency of data structure on XML documents. The purpose of this paper is to present a hybrid XML data model architecture for the storage and search of XML document data. By representing both data and structure views of XML documents, this new XML data model technique overcomes the limitations of previous researches on data model for XML documents as well as the existing database systems such as relational and object-oriented data model
A case study on swell correction of Chirp sub-bottom profiler (SBP) data using multi-beam echo sounder (MBES) data
High-resolution marine seismic data acquisition and subsequent analyses are highly influenced by sea conditions, directly affecting data quality and interpretation. Traditional swell effect correction methods are effective in improving reflector continuity; however, they are less useful for enhancing travel time consistency at intersection points of crossing lines. To develop a robust swell-removal technique for a set of crossing lines multi-beam echo sounder (MBES) data and Chirp sub-bottom profiler (SBP) data were acquired. After generation of a time structure map of the sea-bottom converted from the final processed multi-beam data, a moving average was used to improve the event continuity of the sea-bottom reflection of the Chirp SBP data. Using the position of the Chirp SBP data, the difference between the travel time of the sea-bottom from the smoothed map and the original travel time of the sea-bottom is calculated as a static correction. The static correction method based on the MBES data was compared and verified using three different cases: (i) simple 2D swell effect correction on a line-by-line basis, (ii) comparing the swell corrections at the crossing positions of 2D lines acquired from different dates, and (iii) comparison of ties of intersection points between 2D lines after new swell correction applied. Although a simple 2D swell correction showed great enhancement of reflector continuity, only the full static correction using the newly proposed method using MBES data produced completely corrected reflection events especially at the crossing points of 2D lines
A Photometric and Spectroscopic Study of the Short-Period Algol EW Bo\"{o}tis with a Sct Pulsator
In this paper, we present TESS photometry and high-resolution spectra of the
short-period Algol EW Boo. We obtained double-lined radial velocities (RVs)
from the time-series spectra and measured the effective temperature of the
primary star as = 8560 118 K. For the orbital period
study, we collected all times of minima available for over the last 30 years.
It was found that the eclipse timing variation of the system could be
represented by a periodic oscillation of 17.6 0.3 years with a
semi-amplitude of 0.0041 0.0001 d. The orbital and physical parameters
were derived by simultaneously analyzing the TESS light and RV curves using the
Wilson-Devinney (WD) binary star modeling code. The component masses and radii
were showed over 3% precision: = 2.67 0.08 M,
= 0.43 0.01 M, = 2.01 0.02 R, and
= 1.35 0.01 R. Furthermore, multiple frequency
analyses were performed for the light-curve residuals from the WD model. As a
result, we detected 17 pressure-mode pulsations in the region of 40.15 - 52.37
d. The absolute dimensions and pulsation characteristics showed that the
Sct pulsator was the more massive and hotter primary star of the EW
Boo.Comment: 27 pages, 8 figures, Accepted for publication in A
Trends in Gender-based Health Inequality in a Transitional Society: A Historical Analysis of South Korea
ANTIPROLIFERATION EFFECTS OF SELECTED TANZANIA PLANTS
Background: Plants still remain a prime source of drugs for the treatment of cancer and can provide leads for the development of novel anticancer agents. Our screening of indigenous medicinal plants from Tanzania has led to the identification of the number of anticancer activity.
Material and methods: The current study investigates the cytotoxic activity of methanol extracts of one hundred and thirty seven Tanzania plants used locally for the traditional medicine herb using the MTS assay on the HepG2 cell lines.
Result 16% of the tested plant extracts showed moderate to strong inhibitory activity with IC50 values ranging from 17.1 ± 1.1 μg/ml to 79.2 ± 0.7 μg/ml ; meanwhile, ten extracts (7.3%) could demonstrate cytotoxic activity with IC50 values less than 27.6 ± 2.0 μg/ml; twelve extracts (8.8%) could demonstrate cytotoxic activity with IC50 values ranging from 30.4 ± 1.6 μg/ml to 79.2 ± 0.7μg/ml.
Conclusion : Especially, a methanol extract from the bark extract of Erythrophleum zimmermannii (Fabaceae) was found to be the most cytotoxicity against HepG2 cell lines (IC50 = 17.1 ± 1.1 μg/ml)
- …