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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

Computerized Analysis of Radiograph Images of Embedded Objects as Applied to Bone Location and Mineral Content Measurement

Buckner, Richard L. 08 1900 (has links)
This investigation dealt with locating and measuring x-ray absorption of radiographic images. The methods developed provide a fast, accurate, minicomputer control, for analysis of embedded objects. A PDP/8 computer system was interfaced with a Joyce Loebl 3CS Microdensitometer and a Leeds & Northrup Recorder. Proposed algorithms for bone location and data smoothing work on a twelve-bit minicomputer. Designs of a software control program and operational procedure are presented. The filter made wedge and limb scans monotonic from minima to maxima. It was tested for various convoluted intervals. Ability to resmooth the same data in multiple passes was tested. An interval size of fifteen works well in one pass.
2

A comparative microscopic study of human and non-human long bone histology

Nor, Faridah Mohd January 2009 (has links)
Identification of human or nonhuman skeletal remains is important in assisting the police and law enforcement officers for the investigation of forensic cases. Identification of bone can be difficult, especially in fragmented remains. It has been reported that 25 to 30% of medicolegal cases, which involved nonhuman skeletal remains have been mistaken for human. In such cases, histomorphometric method was used to identify human and nonhuman skeletal remains. However, literature has shown that histomorphometric data for human and nonhuman bone were insufficient. Additionally, age estimation in bone may help in the identification of human individual, which can be done by using a histomorphometric method. Age estimation is based on bone remodeling process, where microstructural parameters have strong correlations with age. Literature showed that age estimation has been done on the American and European populations. However, little work has been done in the Asian population. The aims of this project were thus, to identify human and nonhuman bone, and to estimate age in human bones by using histomorphometric analysis. In this project, 64 human bones and 65 animal bones were collected from the mortuary of the Universiti Kebangsaan Malaysia Medical Centre and the Zoos in Malaysia, respectively. A standard bone preparation was used to prepare human and nonhuman bone thin sections for histomorphometric assessment. Assessments were made on the microstructural parameters such as cortical thickness, medullary cavity diameter, osteon count, osteon diameter, osteon area, osteon perimeter, Haversian canal diameter, Haversian canal area, Haversian canal perimeter, and Haversian lamella count per osteon by using image analysis, and viewed under a transmitted light microscope. The microstructural measurements showed significant differences between human and nonhuman samples. The discriminant functions showed correct classification rates for 81.4% of cases, and the accuracy of identification was 96.9% for human and 66.2% for animal. Human age estimation showed a standard error of estimate of 10.41 years, comparable with those in the literature. This study project offers distinct advantages over currently available histomorphometric methods for human and nonhuman identification and human age estimation. This will have significant implications in the assessment of fragmentary skeletal and forensic population samples for identification purposes.
3

A burning question : structural and isotopic analysis of cremated bone in archaeological contexts

Snoeck, Christophe January 2014 (has links)
Cremated bone occurs in many archaeological sites as small grey and white fragments. The high temperatures reached during heating induce structural, chemical and isotopic changes to bone apatite (the inorganic fraction of bone). These changes are investigated here by infrared spectroscopy and mass spectrometry (d13C, d18O and 87Sr/86Sr) in both modern heated bone and archaeological cremated specimens. The results of various heating experiments (in laboratory and natural conditions) highlight the significant carbon and oxygen exchanges with the fuel used as well as with bone organic matter (mainly collagen). While not informing on dietary practice and hydrology as is the case with unburned bone, the d13C and d18O values of calcined samples together with infrared results provide information on the conditions in which the bone was heated (e.g. presence of fuel, size of the pyre, temperatures reached, dry or fresh bone, etc.). In parallel, the effect of heat on the strontium present in bone is minimal, if not undetectable. Furthermore, as observed through artificial contamination experiments, post-burial alterations also appear to be extremely limited, which is to be expected due to the higher crystallinity of calcined bone apatite compared to tooth enamel and unburned bone. These experiments demonstrate that calcined bone provides a reliable substrate for mobility studies using its strontium isotope composition. The application of these results to the study of six Neolithic and one Bronze Age sites from Ireland showed the possibility of discriminating cremated individuals that ate food originating from different regions, as well as highlighting possible variations in cremation practices between different sites. The results of this thesis greatly extend the application of strontium isotopes to places and periods in which cremation was the dominant mortuary practice, or where unburned bone and enamel do not survive. They also provide insights into the reconstruction of ancient cremation practices.
4

A comparative microscopic study of human and non-human long bone histology.

Nor, Faridah M. January 2009 (has links)
Identification of human or nonhuman skeletal remains is important in assisting the police and law enforcement officers for the investigation of forensic cases. Identification of bone can be difficult, especially in fragmented remains. It has been reported that 25 to 30% of medicolegal cases, which involved nonhuman skeletal remains have been mistaken for human. In such cases, histomorphometric method was used to identify human and nonhuman skeletal remains. However, literature has shown that histomorphometric data for human and nonhuman bone were insufficient. Additionally, age estimation in bone may help in the identification of human individual, which can be done by using a histomorphometric method. Age estimation is based on bone remodeling process, where microstructural parameters have strong correlations with age. Literature showed that age estimation has been done on the American and European populations. However, little work has been done in the Asian population. The aims of this project were thus, to identify human and nonhuman bone, and to estimate age in human bones by using histomorphometric analysis. In this project, 64 human bones and 65 animal bones were collected from the mortuary of the Universiti Kebangsaan Malaysia Medical Centre and the Zoos in Malaysia, respectively. A standard bone preparation was used to prepare human and nonhuman bone thin sections for histomorphometric assessment. Assessments were made on the microstructural parameters such as cortical thickness, medullary cavity diameter, osteon count, osteon diameter, osteon area, osteon perimeter, Haversian canal diameter, Haversian canal area, Haversian canal perimeter, and Haversian lamella count per osteon by using image analysis, and viewed under a transmitted light microscope. The microstructural measurements showed significant differences between human and nonhuman samples. The discriminant functions showed correct classification rates for 81.4% of cases, and the accuracy of identification was 96.9% for human and 66.2% for animal. Human age estimation showed a standard error of estimate of 10.41 years, comparable with those in the literature. This study project offers distinct advantages over currently available histomorphometric methods for human and nonhuman identification and human age estimation. This will have significant implications in the assessment of fragmentary skeletal and forensic population samples for identification purposes.
5

Automated design of trabecular structures

Ramin, Ettore January 2010 (has links)
Additive manufacturing technologies are enabling newfound degrees of geometrical complexity to be realised, particularly with regards to internal structures. All of these manufacturing technologies are dependant on their prior design in an appropriate electronic form, either by reverse engineering, or, primarily, by computer-aided design. Within these emerging applications is the design of scaffolds with an intricate and controlled internal structure for bone tissue engineering. There is a consensus that ideal bone scaffold geometry is evident in biological trabecular structures. In their most basic topological form,these structures consist of the non-linear distribution of irregular interconnecting rods and plates of different size and shape. Complex and irregular architectures can be realised by several scaffold manufacturing techniques, but with little or no control over the main features of the internal geometry, such as size, shape and interconnectivity of each individual element. The combined use of computer aided design systems and additive manufacturing techniques allows a high degree of control over these parameters with few limitations in terms of achievable complexity. However, the design of irregular and intricate trabecular networks in computer aided design systems is extremely time-consuming since manually modelling an extraordinary number of different rods and plates, all with different parameters, may require several days to design an individual scaffold structure. In an attempt to address these difficulties, several other research efforts in this domain have largely focussed on techniques which result in designs which comprise of relatively regular and primitive shapes and do not represent the level of complexity seen biologically. Detailed descriptions of these methods are covered in chapter 1. An automated design methodology for trabecular structures is proposed by this research to overcome these limitations. This approach involves the investigation of novel software algorithms, which are able to interact with a conventional computer aided design program and permit the automated design of geometrical elements in the form of rods, each with a different size and shape. The methodology is described in chapter 2 and is tested in chapter 3. Applications of this methodology in anatomical designs are covered in chapter 4. Nevertheless, complex designed rod networks may still present very different properties compared to trabecular bone geometries due to a lack detailed information available which explicitly detail their geometry. The lack of detailed quantitative descriptions of trabecular bone geometries may compromise the validity of any design methodology, irrespective of automation and efficiency. Although flexibility of a design methodology is beneficial, this may be rendered inadequate when insufficient quantitative data is known of the target structure. In this work a novel analysis methodology is proposed in chapter 5, which may provide a significant contribution toward the characterisation and quantification of target geometries, with particular focus on trabecular bone structures. This analysis methodology can be used either to evaluate existing design techniques or to drive the development of new bio-mimetic design techniques. This work then progresses to a newly derived bio-mimetic automated design technique, driven by the newly produced quantitative data on trabecular bone geometries. This advanced design methodology has been developed and tested in chapter 6. This has demonstrated the validity of the technique and realised a significant stage of development in the context and scope of this work.

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