Results 31 to 40 of about 1,027,849 (126)

Whole genome population structure of North Atlantic kelp confirms high‐latitude glacial refugia

Molecular Ecology, Volume 31, Issue 24, Page 6473-6488, December 2022., 2022
Abstract Coastal refugia during the Last Glacial Maximum (~21,000 years ago) have been hypothesized at high latitudes in the North Atlantic, suggesting marine populations persisted through cycles of glaciation and are potentially adapted to local environments.
Trevor T. Bringloe, Antoine Fort, Masami Inaba, Ronan Sulpice, Cliodhna Ní Ghriofa, Agnes Mols‐Mortensen, Karen Filbee‐Dexter, Christophe Vieira, Hiroshi Kawai, Takeaki Hanyuda, Dorte Krause‐Jensen, Birgit Olesen, Samuel Starko, Heroen Verbruggen   +13 more
wiley   +1 more source

Synchronous Vibration Parameters Identification of Variable Rotating Speed Blades Based on New Improved Two‐Parameter Method without OPR Sensor

Shock and Vibration, Volume 2021, Issue 1, 2021., 2021
Blade tip‐timing is one of the most effective methods for blade vibration parameters identification of turbomachinery. Once‐per revolution (OPR) sensor is usually used to determine the rotating speed and as a time reference. However, the OPR sensor leads to a large measurement error or even failure, or it is difficult to install.
Liang Zhang, Huiqun Yuan, Xin Li, Paola Forte   +3 more
wiley   +1 more source

Synchronous Vibration Parameter Recognition of Constant-Speed Blades Based on Blade Tip Clearance Measurement

Applied Sciences, 2023
A new method for the synchronous vibration parameter identification of constant-speed rotating blades based on blade tip clearance (BTC) measurement and blade tip timing (BTT) is introduced.
Liang Zhang, Yiming Xia, Cong Chen, Qingxi Song, Junjun Cao   +4 more
doaj   +1 more source

Prediction of Blade Tip Timing Sensor Waveforms Based on Radial Basis Function Neural Network

Applied Sciences, 2023
As the existing Blade Tip Timing (BTT) vibration measurement methods have serious under-sampling problems, where the blade resonance frequency is usually higher than the sampling frequency of the data acquisition system of the BTT method, resulting in ...
Liang Zhang, Cong Chen, Yiming Xia, Qingxi Song, Junjun Cao   +4 more
doaj   +1 more source

Analysis and Calibration of Blade Tip-Timing Vibration Measurement Under Variable Rotating Speeds

IEEE Access, 2021
Blade tip timing (BTT) vibration measurement is a promising on-line blade monitoring method, but various uncertainties bring great challenge in engineering applications. Most existing works are based on the assumption of constant rotating speeds. However,
Zhongsheng Chen, Yemei Xia, Hao Sheng, Jing He   +3 more
doaj   +1 more source

An Improved Circumferential Fourier Fit (CFF) Method for Blade Tip Timing Measurements

Applied Sciences, 2020
Rotating blade vibration measurements are very important for any turbomachinery research and development program. The blade tip timing (BTT) technique uses the time of arrival (ToA) of the blade tip passing the casing mounted probes to give the blade ...
Zhibo Liu, Fajie Duan, Guangyue Niu, Ling Ma, Jiajia Jiang, Xiao Fu   +5 more
doaj   +1 more source

Deep Learning for Compressed Sensing-Based Blade Vibration Reconstruction From Sub-Sampled Tip-Timing Signals

IEEE Access, 2023
Blade tip-timing (BTT) signals are always seriously under sampled, so reconstruction is much needed for vibration analysis. Blade vibration responses are sparse in order domain and classical compressed sensing (CS) algorithms are difficult to reconstruct
Zhongsheng Chen, Hao Sheng, Lianying Liao, Chengwu Liu, Yeping Xiong   +4 more
doaj   +1 more source

An expert system aided method of the blade vibration sources identification with blade-tip timing (BTT) signal decomposition

Journal of KONBiN, 2018
Abstract An expert system aided method of the blade-tip signal decomposition to the turbine blade vibration sources identification is presented. The method utilises a multi-valued diagnostic model based on the discrete wavelet transform.
Henryk Borowczyk, Edward Rokicki, Jarosław Spychała   +2 more
openaire   +1 more source

BTT & RFLB - THE OPTIMUM SET FOR STEAM TURBINE BLADES MONITORING

Acta Polytechnica CTU Proceedings, 2018
BTT, Blade Tip Timing system, is a commercially available system generating files of precise times of blade tips when passing sensors attached in a machine stator.
Miroslav Balda
doaj   +1 more source

CALIBRATION OF BTT MEASUREMENT WITH RESPECT TO SENSOR POSITION OVER SHROUDED LSB

Acta Polytechnica CTU Proceedings, 2018
In order to increase efficiency and reliability of steam turbines, last stage blades are equipped with mid-span tie-boss and shroud. We can use Blade Tip-Timing method (BTT) to measure vibration of shrouded blades, but the measured level of vibration is ...
Tereza Dadáková, Zdeněk Kubín
doaj   +1 more source