• Journal of The Korean Astronomical Society
• /
• v.37 no.5
• /
• pp.563-570
• /
• 2004

Turbulence is a crucial component of dynamics of astrophysical fluids dynamics, including those of ISM, clusters of galaxies and circumstellar regions. Doppler shifted spectral lines provide a unique source of information on turbulent velocities. We discuss Velocity-Channel Analysis (VCA) and its offspring Velocity Coordinate Spectrum (VCS) that are based on the analytical description of the spectral line statistics. Those techniques are well suited for studies of supersonic turbulence. We stress that a great advantage of VCS is that it does not necessary require good spatial resolution. Addressing the studies of mildly supersonic and subsonic turbulence we discuss the criterion that allows to determine whether Velocity Centroids are dominated by density or velocity. We briefly discuss ways of going beyond power spectra by using of higher order correlations as well as genus analysis. We outline the relation between Spectral Correlation Functions and the statistics available through VCA and VCS.

• Wind and Structures
• /
• v.1 no.3
• /
• pp.203-223
• /
• 1998

This paper describes in detail the features of an extensive study on Spectral Density Functions (SDF's) of wind pressures acting on several low building roof geometries carried out in a boundary layer wind tunnel. Various spectral characteristics of wind pressures on roofs with emphasis on derivation of suitable analytical representation of spectra and determination of characteristic spectral shapes are shown. Standard spectral shapes associated with various zones of each roof and their parameters are provided. The established spectral parameters can be used to generate synthetic spectra adequate for the simulation of wind pressure fluctuations on building surfaces in a generic fashion.

• Analytical Science and Technology
• /
• v.35 no.4
• /
• pp.143-152
• /
• 2022

In this review, previous studies on the synthesis and characterization of the metal Complexes with paracetamol by elemental analysis, thermal analysis, (IR, NMR and UV-Vis (spectroscopy and conductivity. In reviewing these studies, the authors found that paracetamol can be coordinated through the pair of electrons on the hydroxyl O-atom, carbonyl O-atom, and N-atom of the amide group. If the paracetamol was a monodentate ligand, it will be coordinated by one of the following atoms O-hydroxyl, O-carbonyl or N-amide. But if the paracetamol was bidentate, it is coordinated by atoms (O-carbonyl and N-amide), (O-hydroxyl and N-amide) or (O-carbonyl and O-hydroxyl). The authors also found that free paracetamol and its complexes have antimicrobial activity.

• Geotechnical Engineering
• /
• v.13 no.3
• /
• pp.53-62
• /
• 1997

Analytical studies were conducted to develop the Spectral-Analysis-of-Surface-Waves (SASW) method for underwater use. For the precise estimation of the in-situ soil stiffness profile from SASW measurements, it is essential to determine economical and reasonable theoretical dispersion curves reflecting various experimental conditions. In this paper, therefore, analytical methods are mainly discussed, which were developed to determine theoretical dispersion curves of surface waves propagated along the soil-water interface. Application of the analytical methods is then illustrated by an example involving estimation of a stiffness profile through a forward modeling process of SASW measurements. Applicabilities of the SASW method as well as the developed analytical methods are evaluated, respectively, from the example.

• Bulletin of the Korean Chemical Society
• /
• v.32 no.1
• /
• pp.131-136
• /
• 2011

Synthesis of N-(1H-benzimidazol-2-yl)-6-substituted-1,3-benzothiazol-2-amines and 6-substituted-N-(4,5-dihydro-1H-imidazol-2-yl)-1,3-benzothiazol-2-amines by the reaction of substituted 2-aminobenzothiazoles with carbon disulphide and methyl iodide followed by the reaction with o-phenylene diamine/ethylene diamine are reported. All the synthesized compounds were characterized by elemental analysis, IR spectra and $^1H$ NMR spectral studies. The potent antibacterial and entomological (antifeedant, acaricidal, contact toxicity and stomach toxicity) activities of the synthesized compounds were investigated.

• Geomechanics and Engineering
• /
• v.11 no.6
• /
• pp.821-845
• /
• 2016

Extensive researches on distribution of earthquake induced damages in different regions have shown that geological and geotechnical conditions of the local soils significantly influence behavior of alluvial areas under seismic loading. In this article, the site of Babol city which is formed up of saturated fine alluvial soils is considered as a case study. In order to reduce the uncertainties associated with earthquake resistant design of structures in this area (Babol city), the required design parameters have been evaluated with consideration of site's dynamic effects. The utilized methodology combines experimental ground ambient noise analysis, expressed in terms of horizontal to vertical (H/V) spectral ratio, with numerical one-dimensional response analysis of soil columns using DEEPSOIL software. The H/V spectral analysis was performed at 60 points, experimentally, for the region in order to estimate both the fundamental period and its corresponding amplification for the ground vibration. The investigation resulted in amplification ratios that were greater than one in all areas. A good agreement between the proposed ranges of natural periods and alluvial amplification ratios obtained through the analytical model and the experimental microtremor studies verifies the analytical model to provide a good engineering reflection of the subterraneous alluviums.

• Korean Journal of Pharmacognosy
• /
• v.33 no.4 s.131
• /
• pp.395-398
• /
• 2002

A chemical investigation of Peucedanum praeruptorum has resulted in the isolation of 3 khellactone derivatives, which have inhibitory effects on melanogenesis in Bl6 mouse melanoma cell lines. The khellactone derivatives were isolated from the crude extract of the roots of Pecedanum praeruptorum by a combination of adsorption chromatography and HPLC. The structlues of isolated compounds were identified as 3',4'- diangeloyl-cis-khellactone, 3'-angeloyl- 4'- senecioyl-cis-khel- lactone and,3', 4'-disenecioyl-cis-khellactone by $^1H\;NMR$, $^{13}C\;NMR$ and mass spectral studies and by comparisons of spectral data with reported literatures.

• Bulletin of the Korean Chemical Society
• /
• v.34 no.2
• /
• pp.367-373
• /
• 2013

The ruthenium(II) ferrocenyl heterocyclic thiosemicarbazone complexes of the type $[RuCl(CO)(EPh_3)]_2L$ (where E = P/As; L = binucleating monobasic tridendate thiosemicarbazone ligand) have been investigated. Strutural features were determined by analytical and spectral techniques. Binding of these complexes with CT-DNA by absorption spectral study indicates that the ruthenium(II) complexes form adducts with DNA and has intrinsic binding constant in the range of $3.3{\times}10^4-1.2{\times}10^5M^{-1}$. The complexes exhibit a remarkable DNA cleavage activity with CT-DNA in the presence of hydrogen oxide and the cleavage activity depends on dosage.

• Journal of the Korean Chemical Society
• /
• v.47 no.5
• /
• pp.447-459
• /
• 2003

Generalized 2D correlation spectroscopy has been applied extensively to the analysis of spectral data sets obtained during the observation of a system under some external perturbation. It is used in various fields of spectroscopy including IR, Raman, UV, fluorescence, X-ray diffraction, and X-ray absorption spectroscopy (XAS) as well as chromatography. 2D hetero-spectral correlation analysis compares two completely different types of spectra obtained for a system under the same perturbation. Because of the wide range of applications of this technique, it has become one of the standard analytical techniques for the analytical chemistry, physical chemistry, biochemistry, and so on, and for studies of polymers, biomolecules, nanomaterials, etc. In this paper, we will introduce the principle of generalized 2D correlation spectroscopy and its applications that we have studied.

• Journal of the Korean Association of Geographic Information Studies
• /
• v.18 no.1
• /
• pp.48-63
• /
• 2015

In this study, we introduce various hyperspectral data processing techniques for the monitoring of shallow and coastal waters to enlarge the application range and to improve the accuracy of the end results in Korea. Unlike land, more accurate atmospheric correction is needed in coastal region showing relatively low reflectance in visible wavelengths. Sun-glint which occurs due to a geometry of sun-sea surface-sensor is another issue for the data processing in the ocean application of hyperspectal imagery. After the preprocessing of the hyperspectral data, a semi-analytical algorithm based on a radiative transfer model and a spectral library can be used for bathymetry mapping in coastal area, type classification and status monitoring of benthos or substrate classification. In general, semi-analytical algorithms using spectral information obtained from hyperspectral imagey shows higher accuracy than an empirical method using multispectral data. The water depth and quality are constraint factors in the ocean application of optical data. Although a radiative transfer model suggests the theoretical limit of about 25m in depth for bathymetry and bottom classification, hyperspectral data have been used practically at depths of up to 10 m in shallow and coastal waters. It means we have to focus on the maximum depth of water and water quality conditions that affect the coastal applicability of hyperspectral data, and to define the spectral library of coastal waters to classify the types of benthos and substrates.