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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Biosynthesis of glycophospholipid anchors

Singh, Neena January 1990 (has links)
No description available.
2

Standardization of test methodology: a comparison between three suture anchors

Jonnalagadda, Silpa P. 29 August 2005 (has links)
Suture anchors have been used successfully in many applications in orthopedics. They have been in the forefront of research in the recent years. Most of the studies, though, have focused on human suture anchors. This research concentrates on the veterinary aspect of suture anchors. Currently, there is no standardization of testing methods. One of the objectives of this research is to develop a standardized method of testing that is clinically relevant, at least for veterinary use. Another objective of this research is to compare the durability of three commercial suture anchors manufactured by Innovative Animal Products, Securos Veterinary Orthopedic Inc. and IMEXTM by comparing their pullout loads after cyclic loading. This research also aims to determine whether suture anchor failure due to eyelet cut-out or suture wear-out resulting from the sharp edges of the eyelet is the major cause of failure of bone-suture anchor-bone complexes. Cyclic loading of suture anchors during testing for durability has not been used previously even though such loading plays an important role in determining the stability of the bone-suture anchor-bone construct. The response of the construct to this type of testing followed by pullout tests has been explored in this research.
3

Standardization of test methodology: a comparison between three suture anchors

Jonnalagadda, Silpa P. 29 August 2005 (has links)
Suture anchors have been used successfully in many applications in orthopedics. They have been in the forefront of research in the recent years. Most of the studies, though, have focused on human suture anchors. This research concentrates on the veterinary aspect of suture anchors. Currently, there is no standardization of testing methods. One of the objectives of this research is to develop a standardized method of testing that is clinically relevant, at least for veterinary use. Another objective of this research is to compare the durability of three commercial suture anchors manufactured by Innovative Animal Products, Securos Veterinary Orthopedic Inc. and IMEXTM by comparing their pullout loads after cyclic loading. This research also aims to determine whether suture anchor failure due to eyelet cut-out or suture wear-out resulting from the sharp edges of the eyelet is the major cause of failure of bone-suture anchor-bone complexes. Cyclic loading of suture anchors during testing for durability has not been used previously even though such loading plays an important role in determining the stability of the bone-suture anchor-bone construct. The response of the construct to this type of testing followed by pullout tests has been explored in this research.
4

AN AUTOMATED ANCHORING SYSTEM FOR AN UNMANNED SURFACE VEHICLE

Unknown Date (has links)
The goal of this thesis is to simulate, design and build an automated device that allows unmanned vessels to anchor themselves in specified locations while being United States Coast Guard Navigation Rules compliant. This is a part of a larger project funded by the U.S. Department of Energy for Florida Atlantic University to build an unmanned platform with an Undershot Water Wheel on it. By simulating the environment of the South Florida Intercoastal Water Ways, forces acting on the line, anchor and the vessel are analyzed. These forces are used as the guide for the design and build of a line locking mechanism that takes the tension off the winch and a sensor package to monitor the environment the platform is in as well as control of the system. Based off experimental testing, the system was successful in handling all emulated environments with loads exceeding 150lbs of tension. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2021. / FAU Electronic Theses and Dissertations Collection
5

Test of glass fiber reinforced polymer (GFRP) anchors

Wang, Haomin Helen 25 March 2014 (has links)
A study to investigate the behavior of glass fiber reinforced polymer (GFRP) anchors was conducted at the Ferguson Structural Engineering Laboratory as part of a project funded by the Texas Department of Transportation, Project number 0-6873. The purpose of this study was to test the effectiveness of GFRP anchors by comparing their performance to that of anchors made from carbon fiber reinforced polymer (CFRP). The findings of this research give insight into the advantages and disadvantages of using alternative materials in the design of FRP anchorage systems and provides a means for developing quality control procedures of GFRP anchors. Quantitative comparisons were made between results from beam tests that used GFRP anchors and the results from those that used CFRP anchors. It was found that specimens with GFRP anchors exhibited similar trends to specimens with CFRP anchors. Similarities were achieved in concrete cracking loads, strength capacities, and in some cases duration of force transfer, suggesting that GFRP anchors are equally as effective as CFRP anchors for strength development. However, material differences played a major role in the explanation of GFRP and CFRP behavior. Notable advantages in material handling was observed with the GFRP anchors since the fibers were found to be easier to bend as well as easier to install into drilled anchor holes. On the other hand, the lower tensile strength of GFRP presented a potential need for larger sized anchors to achieve the equivalent strength of a CFRP anchor. Finally, a pull-out failure mode was observed in GFRP anchors that had not been previously observed in CFRP anchors. It was suggested that the pull-out failure mode was a function of differences in deformation capacity between the two materials. However, little information regarding the cause of performance differences demonstrates the need for quality control tests for GFRP anchors. As a result, recommendations for further studies were made. / text
6

Condition monitoring of ground anchorages using artificial intelligence techniques

Starkey, Andrew J. January 2001 (has links)
Neural networks are a form of Artificial Intelligence based on the architecture of the human brain. They allow complicated non-linear relationships to be learnt from example data, and for further test data to be identified according to the relationship previously learnt. This allows the construction of control systems and diagnostic systems of geotechnical processes which were previously not possible due to their complicated non-linear nature. The main topic of research is the application of neural networks to the diagnosis of the condition of ground anchorages. Ground anchorages are in use in many engineering structures such as tunnels, retaining walls and dams and it has been reported that only 5-10% are routinely monitored during service. The conventional method of testing is load lift-off testing, which is expensive and time consuming. The patented technique, GRANIT, makes use of neural networks to learn the complicated relationship between the vibrational response of an anchorage to an applied axial impulse and its post-tension level. Research has been conducted into the parameters of the system which affect the diagnostic ability of the neural network. Further research into the application of the GRANIT technique to the identification of other faults in the anchorage has been conducted, such as change in free length, or gaps in the grouting. An automated procedure for the identification of the frequencies of interest in the response signatures of the GRANIT system has been investigated, and an example is given of an application of this automated procedure in the area of vibro-impact ground moling, a patented technique which uses both vibration and impact to maximise its penetration depth. Further research into the use of neural networks in an automated process has also been undertaken, and the development of a new technique is presented. This new technique has the potential of returning parameters of interest from any given group of signals, and has potential of application outwith geotechnical data. A patent application for this new technique has now been filed by the author.
7

Studies of the interface resistance of soil nails

Standing, James R. January 1997 (has links)
No description available.
8

Shear strengthening of reinforced concrete beams with carbon fiber reinforced polymer (CFRP) and improved anchor details

Quinn, Kevin Timothy 03 August 2010 (has links)
Fifteen tests were conducted to evaluate the shear performance of beams with carbon fiber reinforced polymer (CFRP) laminates and CFRP anchors. The specimens consisted of 24-in. deep T-beams. The specimens were strengthened in shear with CFRP laminates that were anchored using several different CFRP end anchorage details. Load was applied to the reinforced concrete members at three different shear span-to-depth ratios. Observations of the behavior and data from the tests were used to evaluate the performance of the CFRP laminates and CFRP anchors. Overall, a 30-40% increase in shear strength was observed when anchored CFRP laminates were installed on members loaded at a shear span-to-depth ratio greater than two. The CFRP strengthening system performed well when properly detailed CFRP anchors were installed. Design recommendations regarding the installation of the CFRP anchors were developed. The CFRP anchorage detail developed in this study provided additional CFRP material in critical locations to reinforce the anchor and prevent premature failures from occurring due to anchor rupture. Theoretical calculations predicting the shear strength of the retrofitted concrete members were carried out and compared to the measured strengths of the members. Based on this analysis, a design equation was developed that produced conservative results for all of the specimens tested. / text
9

Undrained behavior of plate anchors subjected to general loading

Yang, Ming 14 January 2010 (has links)
This study presents a method for predicting the undrained behavior of plate anchors, including out-of-plane loading of simple plates and performance of suction embedded plate anchors (SEPLA). Three dimensional finite element models are used to investigate the behavior of square and rectangular plate anchors under normal loading with eccentricity in any direction. Upper bound analyses are performed for parallel loading and torsion loading. A simple model is then fit to the FE and upper bound solutions to determine required fitting parameters for both square and rectangular plates. The simple models can, in turn, be used both to predict anchor capacity and as yield surfaces for conducting plastic limit analyses, a method capable of predicting post yield anchor trajectory. The model predictions are shown in reasonable good agreement with the experimental results. For SEPLA, a theoretical model of plastic limit analysis is developed to predict the trajectory during the “keying” process and the ultimate capacity after the “keying” is complete. The predicted results are consistent with relevant known solutions.
10

Effect of FRP Anchors on the FRP Rehabilitation of Shear Critical RC Beams and Flexure Critical RC Slabs

Baggio, Daniel Frank 20 February 2013 (has links)
The use of fiber-reinforced polymer (FRP) composites as a repair and strengthening material for reinforced concrete (RC) members has increased over the past twenty years. The tendency for FRP sheets to debond at loads below their ultimate capacity has prompted researchers to investigate various approaches and designs to increase the efficiency of FRP strengthening systems. Various anchors, wrapping techniques and clamps have been explored to postpone and/or delay the debonding process which results in premature failure. FRP anchors are of particular interest because they can be selected to have the same material properties as the FRP sheets that are installed for strengthening or repair of the RC member and can be done so using the same adhesives and installation techniques. This research study aimed to investigate the effectiveness of using commercially manufactured FRP anchors to secure FRP sheets installed to strengthen and repair RC beams in shear and RC slabs in flexure. Twenty one shear critical RC beams were strengthened in shear with u-wrapped FRP sheets and FRP anchors. Eight RC one-way slabs were strengthened in flexure with FRP sheets and FRP anchors. The test variables include the type of FRP sheets (GFRP,CFRP), type of FRP anchors (CFRP, GFRP) and the strengthening configuration. The test results of the shear critical RC beams revealed that the installation of commercially manufactured FRP anchors to secure externally applied u-wrap FRP sheets improved the shear behaviour of the strengthened beam. The installation of FRP anchors to secure u-wrapped FRP sheets provided an average 15% increase in the shear strength over companion unanchored beams and improved the ductility of failure experienced with the typical shear failure in beams. The use of FRP anchors allowed the FRP sheets to develop their tensile capacity. Premature failure by FRP debonding was eradicated with the presence of FRP anchors and the failure modes of the strengthened beams with FRP anchors was altered when compared to the companion unanchored beam. Additionally, as the width of a u-wrapped FRP sheet was increased; larger increases in strength were obtained when FRP anchors were used. The test results of the flexure critical RC slabs revealed that the installation of commercially manufactured FRP anchors to secure externally applied u-wrapped FRP sheets improved the behaviour of strengthened slabs. Installation of FRP anchors to secure flexural FRP sheets provided an average 17% increase in strength over companion unanchored beams. The use of FRP anchors allowed the FRP sheets to develop their full tensile strength. Premature failure by CFRP debonding was not eliminated with the presence of FRP anchors; rather the critical failure zone was shifted from the bottom soffit of the slab to the concrete/steel rebar interface. The failure modes of slabs with FRP anchors were altered for all specimens when compared to the companion unanchored slab. The effective strain in the FRP sheet was predicted and compared with the experimental results. The efficiency of FRP anchors defined as the ratio of effective strain in the FRP sheet with and without anchors was related to the increase in strength in beams and slabs. A good correlation was established between the FRP anchor efficiency and the increase in strength. A step-by-step FRP anchor installation procedure was developed and a model to predict the number of FRP anchors required to secure a FRP sheet was proposed. This is the most comprehensive examination of beams and slabs strengthened with FRP sheets and FRP anchors conducted to date. This study provides an engineer with basic understanding of the mechanics, behaviour and failure modes of beams and slabs strengthened with FRP sheets and anchors.

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