Search results for "spectral analysis"
showing 5 items of 105 documents
Tissue classification by texture and spectral analysis of intracoronary ultrasound radio-frequency data
2002
Imaging of vascular structures by intracoronary ultrasound allows in principal the recognition of different lesion types due to the echomorphology in the B-mode image. The subjective visual diagnosis is often difficult, especially the differentiation between thrombi and non-calcified plaque. The aim of this study was the extraction of features from the ultrasound radio-frequency signal for an objective characterization of coronary tissue. Methods of texture analysis and frequency analysis were used to differentiate red and white thrombi in vitro. Eight texture parameters of first and second order significantly differentiated red and white thrombi. The backscatter transfer function of red th…
Complete 1H, 13C{1H}, and 31P NMR Spectral Parameters of Some Pyrophosphates
2017
The 1H, 13C{1H}, and 31P NMR spectral parameters of some pyrophosphates were determined in CDCl3. The most complicated 1H spectrum can be solved fully only as (A3MN)R6XX′R6′(MNA3)′, where R6 (= ―N(CH3)2) is coupled only to phosphorus (X). Second-order coupling between phosphorus was found and solved with iterative analysis. A signal shape of one of the carbon resonance cannot be explained only with couplings. Explanation for exceptional shape was searched from molecular modeling results. peerReviewed
Spectrophotometric determination of phthalocyanines Part II. Phthalocyanines stable in concentrated sulfuric acid
2001
Celem pracy było wykazanie możliwości zastosowania spektroskopii VIS do badań ilościowych różnych związków ftalocyjaniny, w szczególności niepodstawionych kompleksów z metalami, które są trwałe w środowisku stężonego kwasu siarkowego(Vl). Zaproponowano prostą metodę, analizy spektrofotometrycznej VIS, stanowiącą kontynuację wcześniej przedstawionej pracy [1], umożliwiając oznaczanie wielu kompleksów ftalocyjaniny z metalami bloku d, Mpc (gdzie M = Cu, Co, Ni, Zn oraz pc (C(32)H(16)N(8)2- = ligand ftalocyjaninowy). Analiza statystyczna wyników uzyskanych w badaniach kontrolnych wykazała, że opisana metoda może być użyteczna zarówno w zastosowaniach przemysłowych jak i badaniach naukowych.
Exploring a large dataset : typical behavior of UHF signal propagation
2020
Radioverkon suunnittelua ja käyttöä varten täytyy radio aaltojen eteneminen ymmärtää hyvin. Tässä tutkimuksessa tutustutaan laajaan mittausaineistoon hetkellisiä tehoja maanlaajuisesta UHF verkosta. Spektrianalyysillä todettiin mitatussa tehossa olevan jaksollista vaihtelua taajuuksilla kerran ja kahdesti päivässä. Myös nopeampaa vaihtelua välillä 0:1 mHz ja 1:4 mHz todettiin 34% yhteyksistä. Hierarkisella ryhmittelyllä etsittiin tyypilliset mittausten arvojakaumat. Saaduissa arvojakaumien ryhmissä oli eri levyisiä vasemmalle tai oikealle vinoja tai symmetrisiä jakaumia. The design and operation of radio networks requires good understanding of radio propagation. This study explores a datase…
Predicted gamma-ray image of SN 1006 due to inverse Compton emission
2009
We propose a method to synthesize the inverse Compton (IC) gamma-ray image of a supernova remnant starting from the radio (or hard X-ray) map and using results of the spatially resolved X-ray spectral analysis. The method is successfully applied to SN 1006. We found that synthesized IC gamma-ray images of SN 1006 show morphology in nice agreement with that reported by the H.E.S.S. collaboration. The good correlation found between the observed very-high energy gamma-ray and X-ray/radio appearance can be considered as an evidence that the gamma-ray emission of SN 1006 observed by H.E.S.S. is leptonic in origin, though the hadronic origin may not be excluded.