Publications by authors named "R R Rachev"
Deep Learning for Ultrasonic Crack Characterization in NDE.
IEEE Trans Ultrason Ferroelectr Freq Control
May 2021
Article Synopsis
- Machine learning has the potential to improve defect characterization in nondestructive evaluation (NDE), but lacks sufficient real defect training data.
- A hybrid finite element and ray-based simulation approach is proposed to train a convolutional neural network (CNN) for crack characterization in inline pipe inspections.
- The CNN significantly outperforms the traditional 6-dB drop method, showing much lower average absolute errors in predicting crack length and angle, demonstrating the effectiveness of deep learning in NDE applications.
Plane Wave Imaging Techniques for Immersion Testing of Components With Nonplanar Surfaces.
IEEE Trans Ultrason Ferroelectr Freq Control
July 2020
Article Synopsis
- Plane wave imaging (PWI) is used for high-resolution ultrasonic inspections, but existing methods require knowledge of component geometry for effective imaging.
- A new technique called PWI adapted in postprocessing (PWAPP) allows for imaging without the need for prior geometric information, using captured data to reconstruct components and adapt the imaging process.
- PWAPP demonstrated superior results in terms of signal-to-noise ratio (SNR) compared to conventional PWI across various experiments, proving effective even with fewer transmission firings.
Antibiotic TH818 was isolated and purified from a culture broth of Streptomyces fulvoviolaceus 818 by extraction and reversed-phase liquid chromatography. The antibiotic TH818 possesses high molecular mass and unique structure, constructed from carbohydrates, amino acids and lipids. The hydrolysis experiments showed the presence of six fatty acids (hexadecanoic, hexadecenoic, octadecanoic, iso-nonadecanoic, docosanoic and pentacosanoic acids), four sugars (glucose, galactose, N -acetylglucosamine and N -acetylgalactosamine), and seven amino acids (threonine, alanine, glutamic acid, glycine, serine and two unidentified).
View Article and Find Full Text PDFA novel thermostable neutral proteinase from Saccharomonospora canescens.
Biochim Biophys Acta
February 1998
A novel thermostable neutral proteinase, called NPS, was purified to electrophoretic homogeneity from the culture broth of Saccharomonospora canescens sp. novus, strain 5. The molecular mass was determined by SDS-polyacrylamide gel electrophoresis to be 35,000 Da.
View Article and Find Full Text PDFThe amino-terminal oxygen-binding unit Rta of the Rapana thomasiana hemocyanin is a glycoprotein with a carbohydrate content of 4.8% (w/w). Sugar analysis revealed as monosaccharide constituents xylose, fucose, 3-O-methylgalactose, mannose, galactose, N-acetylgalactosamine and N-acetylglucosamine residues.
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