256 research outputs found
Field- and pressure-induced phases in SrRuO: A spectroscopic investigation
We have investigated the magnetic-field- and pressure-induced structural and
magnetic phases of the triple-layer ruthenate - SrRuO.
Magnetic-field-induced changes in the phonon spectra reveal dramatic
spin-reorientation transitions and strong magneto-elastic coupling in this
material. Additionally, pressure-dependent Raman measurements at different
temperatures reveal an anomalous negative Gruneisen-parameter associated with
the B mode ( 380 cm) at low temperatures (T 75K), which
can be explained consistently with the field dependent Raman data.Comment: 5 pages, 4 figures final version published in PRL 96, 067004 (2006
Raman scattering studies of temperature- and field-induced melting of charge order in (La,Pr,Ca)MnO
We present Raman scattering studies of the structural and magnetic phases
that accompany temperature- and field-dependent melting of charge- and
orbital-order (COO) in La0.5Ca0.5MnO3 and La0.25Pr0.375Ca0.375MnO3. Our results
show that thermal and field-induced COO melting in La0.5Ca0.5MnO3 exhibits
three stages in a heterogeneous melting process associated with a structural
change: a long-range, strongly JT distorted/COO regime; a coexistence regime;
and weakly JT distorted/PM or FM phase. We provide a complete structural phase
diagram of La0.5Ca0.5MnO3 for the temperature and field ranges 6<=T<=170 K and
0<=H<=9 T. We also investigate thermal and field-induced melting in
La0.25Pr0.375Ca0.375MnO3 to elucidate the role of disorder in melting of COO.
We find that while thermal melting of COO in La0.25Pr0.375Ca0.375MnO3 is quite
similar to that in La0.5Ca0.5MnO3, the field-induced transition from the COO
phase to the weakly JT-distorted/FM phase in La0.25Pr0.375Ca0.375MnO3 is very
abrupt, and occurs at significantly lower fields (H~2 T at T~0 K) than in
La0.5Ca0.5MnO3 (H~30 T at T=0 K). Moreover, the critical field H_c increases
with increasing temperature in La0.25Pr0.375Ca0.375MnO3 in contrast to
La0.5Ca0.5MnO3. To explain these differences, we propose that field-induced
melting of COO in La0.25Pr0.375Ca0.375MnO3 is best described as the
field-induced percolation of FM domains, and we suggest that Griffiths phase
physics may be an appropriate theoretical model for describing the unusual
temperature- and field- dependent transitions observed in
La0.25Pr0.375Ca0.375MnO3.Comment: 14 pages, 8 figures, to be published in PR
COPS: A Compact On-device Pipeline for real-time Smishing detection
Smartphones have become indispensable in our daily lives and can do almost
everything, from communication to online shopping. However, with the increased
usage, cybercrime aimed at mobile devices is rocketing. Smishing attacks, in
particular, have observed a significant upsurge in recent years. This problem
is further exacerbated by the perpetrator creating new deceptive websites
daily, with an average life cycle of under 15 hours. This renders the standard
practice of keeping a database of malicious URLs ineffective. To this end, we
propose a novel on-device pipeline: COPS that intelligently identifies features
of fraudulent messages and URLs to alert the user in real-time. COPS is a
lightweight pipeline with a detection module based on the Disentangled
Variational Autoencoder of size 3.46MB for smishing and URL phishing detection,
and we benchmark it on open datasets. We achieve an accuracy of 98.15% and
99.5%, respectively, for both tasks, with a false negative and false positive
rate of a mere 0.037 and 0.015, outperforming previous works with the added
advantage of ensuring real-time alerts on resource-constrained devices.Comment: Published at IEEE Consumer Communications & Networking Conference
(CCNC) 202
Psychosocial Characteristics of Patients with Bronchial Asthma and Coronary Disease: Similarities and Differences
The authors compare two groups of subjects: patients with bronchial asthma and
those with coronary disease, with regard to some social characteristics, abilities and
perception of factors which they conceive are important in the etiology of their disease.
Data were obtained by means of a questionnaire based on a known calibrated scale. A
group of 100 patients with bronchial asthma and a group of 102 patients with coronary
disease were examined. The significance of the difference was tested by c
2, t-test, Wilcoxon’s
test and multivariate discriminative analysis.
The results showed statistically significant differences between the patients with
bronchial asthma and those with coronary disease in some social and psychological
characteristics and also with regard to perception of potential etiological factors of their
disease. However, no difference was found in life style and habits between the coronary
and asthmatic patients
Venus/Mercury swingby with Venus capsule. Preliminary science objectives and experiments for use in advanced mission studies
Venus/Mercury swingby with Venus capsule - preliminary science objectives and experiments for use in advanced mission studie
Stability indicating RP-HPLC method for the estimation of flucloxacillin sodium in a tablet dosage form
A Simple, accurate and precise method was developed and validated for the determination of flucloxacillin sodium in its tablet dosage form. The separation was eluted on xterra c18 column (4.6x150mm, 5micron) using a mixture of octane buffer and methanol as mobile phase in a ratio of (30:70) which was pumped through column at a flow rate of 1ml/min. Optimised wavelength for flucloxacillin was 237nm, the retention time was 2.305minutes and the percentage purity was found to be 98.14%. System suitability parameters such as theoretical plate and tailing factor for flucloxacillin sodium was found to be 2991.64 and 1.90 respectively, the proposed method was validated as per ICH guidelines (ICH, Q2 AND (R1)) the method was found to be linear at the concentration range of 20-100µg/ml and the correlation coefficient (r2) value was found to be 0.9994 percentage RSD for precision was 0.9% and percentage RSD for ruggedness was 0.5%. The precision study was precise, robust and repeatable. The LOD and LOQ values are 2.98 and 9.98 respectively. Hence the suggested RP-HPLC method can be used for routine analysis for flucloxacillin sodium in tablet dosage form
Venus - Preliminary science objectives and experiments for use in advanced mission studies
Mission planning and experiment design for future Mariner-type Venus space probe
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