Deposits of clastic carbonate-dominated (calciclastic) sedimentary slope systems in the rock record have been identified mostly as linearly-consistent carbonate apron deposits, even though most ancient clastic carbonate slope deposits fit the submarine fan systems better. Calciclastic submarine fans are consequently rarely described and are poorly understood. Subsequently, very little is known especially in mud-dominated calciclastic submarine fan systems. Presented in this study are a sedimentological core and petrographic characterisation of samples from eleven boreholes from the Lower Carboniferous of Bowland Basin (Northwest England) that reveals a >250 m thick calciturbidite complex deposited in a calciclastic submarine fan setting. Seven facies are recognised from core and thin section characterisation and are grouped into three carbonate turbidite sequences. They include: 1) Calciturbidites, comprising mostly of highto low-density, wavy-laminated bioclast-rich facies; 2) low-density densite mudstones which are characterised by planar laminated and unlaminated muddominated facies; and 3) Calcidebrites which are muddy or hyper-concentrated debrisflow deposits occurring as poorly-sorted, chaotic, mud-supported floatstones. These

Phd by thesis

A team of researchers at Google's DeepMind Technologies has been working on a means to increase the capabilities of computers by combining aspects of data processing and artificial intelligence and have come up with what they are calling a differentiable neural computer (DNC.) In their paper published in the journal Nature, they describe the work they are doing and where they believe it is headed. To make the work more accessible to the public team members, Alexander Graves and Greg Wayne have posted an explanatory page on the DeepMind website. [13]

Convolutional Neural Network를 이용한 한국어 영화평 감성 분석

Advances, limitations and prospects of nondestructive testing and evaluation of thick composites and sandwich structures: A state-of-the-art review

Fault detection and diagnosis for rotating machinery: A model based on convolutional LSTM, Fast Fourier and continuous wavelet transforms

Ultrasonic guided wave (UGW) is one of the most commonly used technologies for non-destructive evaluation (NDE) and structural health monitoring (SHM) of structural components. Because of its excellent long-range diagnostic capability, this method is effective in detecting cracks, material loss, and fatigue-based defects in isotropic and anisotropic structures. The shape and orientation of structural defects are critical parameters during the investigation of crack propagation, assessment of damage severity, and prediction of remaining useful life (RUL) of structures. These parameters become even more important in cases where the crack intensity is associated with the safety of men, environment, and material, such as ship’s hull, aero-structures, rail tracks and subsea pipelines. This paper reviews the research literature on UGWs and their application in defect diagnosis and health monitoring of metallic structures. It has been observed that no significant research work has been convened to identify the shape and orientation of defects in plate-like structures. We also propose an experimental research work assisted by numerical simulations to investigate the response of UGWs upon interaction with cracks in different shapes and orientations. A framework for an empirical model may be considered to determine these structural flaws.

Structural Health Monitoring (SHM) and Determination of Surface Defects in Large Metallic Structures using Ultrasonic Guided Waves.

High-temperature (HT) ultrasonic transducers are of increasing interest for structural health monitoring (SHM) of structures operating in harsh environments. This article focuses on the development of an HT piezoelectric wafer active sensor (HT-PWAS) for SHM of HT pipelines using ultrasonic guided waves. The PWAS was fabricated using Y-cut gallium phosphate (GaPO4) to produce a torsional guided wave mode on pipes operating at temperatures up to 600 °C. A number of confidence-building tests on the PWAS were carried out. HT electromechanical impedance (EMI) spectroscopy was performed to characterise piezoelectric properties at elevated temperatures and over long periods of time (>1000 h). Laser Doppler vibrometry (LDV) was used to verify the modes of vibration. A finite element model of GaPO4 PWAS was developed to model the electromechanical behaviour of the PWAS and the effect of increasing temperatures, and it was validated using EMI and LDV experimental data. This study demonstrates the application of GaPO4 for guided-wave SHM of pipelines and presents a model that can be used to evaluate different transducer designs for HT applications.

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Development of Ultrasonic Guided Wave Transducer for Monitoring of High Temperature Pipelines.

Fouling build up is a known problem in the industry. Accumulation of fouling can occur in different structures e.g. offshore pipes, ship hulls, floating production platforms. The type of fouling that is being accumulated is dependent on environmental conditions surrounding the structure itself. Current methods that are deployed for fouling removal spans over hydraulic, chemical and manual means. Current technologies such as DynaJet (cavitating water jets) and Hydrex's underwater ship hull cleaner have both advantages and disadvantages, where one common disadvantage is to put the operation of the structure to a halt in order to commence the fouling removal process. Currently, ultrasonic baths are used for cleaning by generating cavitation bubbles which implode on the surface of fouling, particularly in Reverse Osmosis applications. Conventionally, components that have accumulated fouling are placed into an ultrasonic bath which yet again, requires to stop the operation of the structure for fouling removal process to commence. Application of high power ultrasonic transducers are proposed in this work as a means to remove fouling on a structure whilst in operation. The work presented in this paper consists of the designing of bespoke high power transducers, transducer array design and development of bespoke power amplifiers to drive the high power transducers. The Polytec 3D Laser Doppler Vibrometer has been incorporated into this investigation to study the fouling removal process. Results shows the potential of using high power ultrasonic transducers for fouling removal in marine structures due to the wave propagation across the structure that is under excitation.

Application of high power ultrasonics for fouling removal in submerged structures

In this paper, a state of the art automated defect recognition (ADR) system is presented that was developed specifically for Non-Destructive Testing (NDT) of powder metallurgy (PM) parts using three dimensional X-ray Computed Tomography (CT) imaging, towards enabling online quality assurance and enhanced integrity confidence. PM parts exhibit typical defects such as microscopic cracks, porosity, and voids, internal to components that without an effective detection system, limit the growth of industrial applications. Compared to typical testing methods (e.g., destructive such as metallography that is based on sampling, cutting, and polishing of parts), CT provides full coverage of defect detection. This paper establishes the importance and advantages of an automated NDT system for the PM industry applications with particular emphasis on image processing procedures for defect recognition. Moreover, the article describes how to establish a reference library based on real 3D X-ray CT images of net-shape parts. The paper follows the development of the ADR system from processing 2D image slices of a measured 3D X-ray image to processing the complete 3D X-ray image as a whole. The introduced technique is successfully integrated into an automated in-line quality control system highly sought by major industry sectors in Oil and Gas, Automotive, and Aerospace.

/pdf/automated-defect-recognition-as-a-critical-element-of-a-14lb7runmi.pdf

Automated Defect Recognition as a Critical Element of a Three Dimensional X-ray Computed Tomography Imaging-Based Smart Non-Destructive Testing Technique in Additive Manufacturing of Near Net-Shape Parts

Fouling formation on high value assets i.e. ships, offshore platforms, pipelines in the processing industry is a significant problem causing destruction to the environment and operations of the structure. Common fouling mechanisms in industry are deposit of scales, settlement and growth of marine organisms. It is an important factor, in order to assess the service lifetime and safety of these assets. Large sums of money are spent for removal and preventative methods to maintain efficient operation of the asset. Most of these methods are toxic and the environmental concerns associated with these techniques has led to studies on alternative methods to remove fouling. This paper proposes a non-invasive method of removing fouling using high power ultrasound. The acoustic cavitation phenomenon is related with the out-of-the-plane displacement occurring in structures for the fouling removal process. This is a cost and time effective method and more importantly, an environmentally sustainable method of fouling removal. Furthermore, this paper presents the research carried out at the Brunel Innovation Centre in this field. Through collaborative research projects, this technology has been developed for different fouling types specific to various industrial applications. A methodology has been established for the selection of the transducers and the hardware. The techniques effectiveness has been proven through experimental and simulation results.

Advancements in fouling removal using high power ultrasonics for industrial applications

In this study, an Impulse Response Function analysis of pile response to sine-sweep excitation by a low cost, portable shaker was used to identify defects in piles. In straightforward impact-echo methods, echoes from the pile toe and defects are visible in the time domain measurements. However, these echoes are not present in the time domain records of piles subjected to sine-sweep excitations, due to interactions between the input and output signals. For this reason, the impulse response function in the time domain has been calculated and is able to identify the echoes from pile impedance changes. The proposed methodology has been evaluated both numerically and experimentally. A one-dimensional pile-soil interaction system was developed, and a finite difference method used to calculate the pile response to sine-sweep excitation. The numerical simulations indicate that impulse response measurements with a synthesized logarithmic, sine-sweep excitation could be an effective tool for detecting defects in piles. The methodology was further tested with field trials on 6 cast in situ concrete test piles including 1 intact pile and 5 defective piles subjected to sine-sweep excitations by a shaker. In 5 of the 6 cases the echoes from the pile toe could be identified in the deconvoluted waveforms—the impulse response functions. Damage detection is more difficult and dependent on the selection of the optimal regularization parameter. Further research and optimization of the deconvolution process is needed to evaluate the effectiveness compared to standard pile integrity testing methods.

Jamil Kanfoud

Papers

Development of Ultrasonic Guided Wave Transducer for Monitoring of High Temperature Pipelines.

Application of high power ultrasonics for fouling removal in submerged structures

Automated Defect Recognition as a Critical Element of a Three Dimensional X-ray Computed Tomography Imaging-Based Smart Non-Destructive Testing Technique in Additive Manufacturing of Near Net-Shape Parts

Advancements in fouling removal using high power ultrasonics for industrial applications

Integrity Testing of Cast In Situ Concrete Piles Based on an Impulse Response Function Method Using Sine-Sweep Excitation by a Shaker