The present study describes the burst behavior of aluminum liner based prototype filament-wound hybrid riser under internal hydrostatic pressure. The main objective of present study is to developed an internal pressure test rig set-up for filament-wound hybrid riser and investigate the failure modes of filament-wound hybrid riser under internal hydrostatic burst pressure loading. The prototype filament-wound hybrid riser used for burst test consists of an internal aluminum liner and outer composite layer. The carbon-epoxy composites as part of the filament-wound hybrid risers were manufactured with [±55<sup>o</sup>] lay-up pattern with total composite layer thickness of 1.6 mm using a CNC filament-winding machine. The burst test was monitored by video camera which helps to analyze the failure mechanism of the fractured filament-wound hybrid riser. The Fiber Bragg Grating (FBG) sensor was used to monitor and record the strain changes during burst test of prototype filament-wound hybrid riser. This study shows good improvements in burst strength of filament-wound hybrid riser compared to the monolithic metallic riser. Since, strain measurement using FBG sensors has been testified as a reliable method, we aim to further understand in detail using this technique.
Authors propose an on-chip solution for continuous transport and separation of microspheres based on a lensless imaging technique, Talbot effect. High contrast intensity pattern of optical lattice is created at Talbot distance within the microfluidic chamber. The advantages of this proposed method include large-scale, power-efficient, compact, simple configuration etc. The binary two-dimensional chessboard grating was designed and fabricated. Experimentally regular array of microspheres were trapped with static optical lattice, while the translation of group of spheres were demonstrated with dynamic optical lattice. And continuous separation of microspheres with different sizes was realized. Finally, the experimental result of passive guiding of a group of spheres on a tilted asymmetric optical landscape was introduced.
A TiNi/diamond-like-carbon (DLC) microcage for biological application has been designed, fabricated and
characterized. A compressively stressed DLC film with TiNi pattern on top lifts the fingers upwards once they are
released from the substrate, and the microcage can be closed through shape memory effect of top TiNi film with
temperature below 80°C. Further heating above 100°C, the gradual opening of the microcage can be obtained due to
thermal bimorph effect. The biocompatibility of both the TiNi and DLC films has been proved using a cell-culture
We present a cost-effective and power efficient approach for on-chip large-scale trapping and sorting of particles in
microchamber. Based on the Talbot self-imaging effect in Fresnel region, we make use of a 2D chessboard structure to
create a 3D interconnected optical lattice near the emergent surface of the element without adopting an external optical
projection configuration. The chessboard structure is designed to be a binary phase grating and fabricated with electron-beam
lithography. As no focusing lens projections system is employed, the presented system enables a larger working
area without sacrificing the advantage of high resolution. Theoretically the created optical lattice allows exponential size
selectivity for particles sorting. We have experimentally demonstrated simultaneous trapping of hundreds of
microparticles in a large regular array. Furthermore, in microfluidic chamber we proved the all-optical continuous
separation of microparticles with different sizes.
A flexible fiber optic endoscope system for investigations in medical cavities using specially designed probe distal and proximal ends so as to facilitate speckle correlation analysis and simultaneous cavity imaging is presented in this paper. The design of the endoscope probe and associated detection system facilitating the analysis of deformation components and their derivatives in cavity surfaces is discussed. The distal end of the probe consists of a single fiber optic port for illumination and an imaging lens-image fiber unit for imaging the reflected speckle pattern from the cavity surface. An optical component selection unit is designed and used at the probe proximal end, for switching between deformation and derivative configurations. Theoretical analysis regarding speckle fringe formation on curved surfaces, for out-of-plane and shear configurations are discussed. Preliminary experimental investigations using the developed probe on inner surfaces of curved phantom tissue specimens are carried out for the abnormal growth detection and the results are analyzed. The obtained experimental results are compared with the developed theory. This probe system and its associated concepts may later lead into the improvements of currently used surgical assisted endoscopic techniques for early cancer diagnosis.
In this paper, we present the design of an endoscope probe, which can image the inner cavity walls as well as collect fluorescence emission from the same cavity inner surfaces, for disease diagnosis in body cavities. The probe makes use of a single coherent laser illumination / excitation source for both modalities. An imaging lens at the probe end collects the fluorescence emission as well as the image from the test surface. Two types of imaging lens are used in the probe and their fluorescence collection efficiencies and imaging capabilities are compared with each other. An eyepiece at the end of the probe directs the transmitted light into a CCD camera / Monochromator through selected filters to display the image / analyze the emission spectrum. The developed probe has been tested in a phantom colon model, where cancerous growths and fluorophores are simulated, so as to illustrate the probe diagnostic efficiency.
A theoretical model, which describes both the spatial distributions of photons in fluorescence endoscopic images for the detection of cancerous cells in the intra cavities of human body, specifically gastrointestinal path is presented in this paper. The design concept of the image probe, which was developed for collecting the low fluorescent emission using an excitation laser source and the imaging done through novel imaging lens scheme will be discussed with its advantages and limitations in comparison with the existing imaging schemes. Finally, a quantitative analysis done by varying the different parameters affecting the tissue fluorescence is discussed in this paper.
Tele-shearographic system based on bulk optics shearing and optical fiber based illumination have been used for the Non-Destructive Testing (NDT)of aircraft/composite laminates. This paper describes the application of this system and a detailed experimental analysis to assess defects in Carbon Fiber Reinforced Plastic (CFRP) composite laminates by analyzing the fringe patterns. CFRP laminates and honeycomb panels have been studied using the this system in various optical configurations. This technique provides the full-field, non-contact method for Non-Destructive Evaluation (NDE) of composite specimens. A Comparative study between digital shearography and other NDTechniques are also discussed in this paper.
In interferometric fringe pattern analysis, specular and speckle fringe patterns are the two main divisions. While specular fringes are characterized by quality fringes with high spatial resolution, speckle (that obtains due to the diffuse scattering of the coherent radiation from an optically rough surface) fringe patterns, which contain high frequency carrier (as noise), are characterized by noisy fringes. This paper concentrates on this aspect and the matlab based filtering methods to improve quality of speckle fringe patterns by developing the appropriate software. Further, the newly developed software Macurv will be presented which can give the second order derivative (curvature) fringe information . A software with several functions is written using Matlab. The objective of the software is to provide a more effective way for post-processing of the speckle interferometric fringes. The algorithm and functions of the developed software Macurv will be explained.
Studies of the effects of various parameters like pre-stress, input azimuth, fiber turns etc. on the polarimetric fiber optic sensing system for smart structure applications are presented. The presence of the smart structure modifies the output characteristics of the highly birefringent fiber due to elastic properties of the structure. Experimental procedures are repeated for Single Mode and the bow-tie HiBi fibers with different optical configurations. Both carbon fiber reinforced (CFRP) and glass fiber reinforced (GFRP) specimens are studied in detail. These experimental evaluation clearly point out that the sensitivity of such embedded polarimetric sensors are affected by the above mentioned parameters. Hence these parameters are optimized for making the smart sensing systems with specific objectives. Keeping the modulated signal at the optimum sensitivity range for the realization of a smart weighing machine and an efficient design of the sensor to increase its range of sensitivity by optimizing the parameters for defect detection in the composite laminates will be the topics of discussion in this paper.
This paper presents a proposal for an optical gas monitoring system based on fieldbus. With the help of the advanced signal processing system more than one hundred gas detectors can be connected to a host system by a single shared bus cable over which the gas detectors, now incorporating with their own intelligence, communicate digitally with the host system. The new system supplies not only about the gas level but also about the physical condition of each sensor. Planed maintenance can be performed to ensure that gas monitor system is maintained in full working order. Integrating fieldbus with optical gas sensor will also have dramatic saving in field wiring and the man-hours for system verification and configuration.