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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.
71

Applications of UV-visible spectral imaging in forensic science

Wagner, John Harry January 2008 (has links)
This study investigated the use of UV-visible spectral imaging for the location and enhancement of substances of forensic interest using targeted approaches based on the spectrum of the substance. Spectral enhancement procedures were developed for blood with and without chemical enhancement, and for latent fingermarks after chemical enhancement. Focus was on substances whose spectrum exhibited a steep change in absorbance or fluorescence over a small wavelength range. Substances with such spectral features were able to be enhanced using arithmetic combinations of two or three spectral images taken at wavelengths near the steep spectral feature. Some enhancement reagents do not react to produce a product with a steep spectral feature suitable for photographic enhancement. In such cases reagents that compliment spectral imaging can be developed. A tridentate ligand for iron(II), BBIDMAPP, which forms a complex with a narrow intense charge-transfer band, was synthesised and was used to visualise muddy shoemarks. UV-visible spectral imaging systems based on a liquid crystal filter or a filter wheel were constructed to facilitate the acquisition of the spectral images and to perform the enhancement operations. A thorough characterisation of the imaging systems determined their limitations and sources of artefacts which could lead to complications in interpreting the enhanced images. The spectral imaging procedure used to visualise blood was incorporated into a near-real-time, hand-held imaging system for the location of blood staining. This prototype imaging system is capable of acquiring two spectral images simultaneously, perform the enhancement procedure, and display the enhanced image within 5 s, which would make it suitable as a non-chemical presumptive screening test for blood at crime scenes.
72

Applications of UV-visible spectral imaging in forensic science

Wagner, John Harry January 2008 (has links)
This study investigated the use of UV-visible spectral imaging for the location and enhancement of substances of forensic interest using targeted approaches based on the spectrum of the substance. Spectral enhancement procedures were developed for blood with and without chemical enhancement, and for latent fingermarks after chemical enhancement. Focus was on substances whose spectrum exhibited a steep change in absorbance or fluorescence over a small wavelength range. Substances with such spectral features were able to be enhanced using arithmetic combinations of two or three spectral images taken at wavelengths near the steep spectral feature. Some enhancement reagents do not react to produce a product with a steep spectral feature suitable for photographic enhancement. In such cases reagents that compliment spectral imaging can be developed. A tridentate ligand for iron(II), BBIDMAPP, which forms a complex with a narrow intense charge-transfer band, was synthesised and was used to visualise muddy shoemarks. UV-visible spectral imaging systems based on a liquid crystal filter or a filter wheel were constructed to facilitate the acquisition of the spectral images and to perform the enhancement operations. A thorough characterisation of the imaging systems determined their limitations and sources of artefacts which could lead to complications in interpreting the enhanced images. The spectral imaging procedure used to visualise blood was incorporated into a near-real-time, hand-held imaging system for the location of blood staining. This prototype imaging system is capable of acquiring two spectral images simultaneously, perform the enhancement procedure, and display the enhanced image within 5 s, which would make it suitable as a non-chemical presumptive screening test for blood at crime scenes.
73

Applications of UV-visible spectral imaging in forensic science

Wagner, John Harry January 2008 (has links)
This study investigated the use of UV-visible spectral imaging for the location and enhancement of substances of forensic interest using targeted approaches based on the spectrum of the substance. Spectral enhancement procedures were developed for blood with and without chemical enhancement, and for latent fingermarks after chemical enhancement. Focus was on substances whose spectrum exhibited a steep change in absorbance or fluorescence over a small wavelength range. Substances with such spectral features were able to be enhanced using arithmetic combinations of two or three spectral images taken at wavelengths near the steep spectral feature. Some enhancement reagents do not react to produce a product with a steep spectral feature suitable for photographic enhancement. In such cases reagents that compliment spectral imaging can be developed. A tridentate ligand for iron(II), BBIDMAPP, which forms a complex with a narrow intense charge-transfer band, was synthesised and was used to visualise muddy shoemarks. UV-visible spectral imaging systems based on a liquid crystal filter or a filter wheel were constructed to facilitate the acquisition of the spectral images and to perform the enhancement operations. A thorough characterisation of the imaging systems determined their limitations and sources of artefacts which could lead to complications in interpreting the enhanced images. The spectral imaging procedure used to visualise blood was incorporated into a near-real-time, hand-held imaging system for the location of blood staining. This prototype imaging system is capable of acquiring two spectral images simultaneously, perform the enhancement procedure, and display the enhanced image within 5 s, which would make it suitable as a non-chemical presumptive screening test for blood at crime scenes.
74

Applications of UV-visible spectral imaging in forensic science

Wagner, John Harry January 2008 (has links)
This study investigated the use of UV-visible spectral imaging for the location and enhancement of substances of forensic interest using targeted approaches based on the spectrum of the substance. Spectral enhancement procedures were developed for blood with and without chemical enhancement, and for latent fingermarks after chemical enhancement. Focus was on substances whose spectrum exhibited a steep change in absorbance or fluorescence over a small wavelength range. Substances with such spectral features were able to be enhanced using arithmetic combinations of two or three spectral images taken at wavelengths near the steep spectral feature. Some enhancement reagents do not react to produce a product with a steep spectral feature suitable for photographic enhancement. In such cases reagents that compliment spectral imaging can be developed. A tridentate ligand for iron(II), BBIDMAPP, which forms a complex with a narrow intense charge-transfer band, was synthesised and was used to visualise muddy shoemarks. UV-visible spectral imaging systems based on a liquid crystal filter or a filter wheel were constructed to facilitate the acquisition of the spectral images and to perform the enhancement operations. A thorough characterisation of the imaging systems determined their limitations and sources of artefacts which could lead to complications in interpreting the enhanced images. The spectral imaging procedure used to visualise blood was incorporated into a near-real-time, hand-held imaging system for the location of blood staining. This prototype imaging system is capable of acquiring two spectral images simultaneously, perform the enhancement procedure, and display the enhanced image within 5 s, which would make it suitable as a non-chemical presumptive screening test for blood at crime scenes.
75

Processing and characterisation of nano-enhanced composites

Frederick, Armstrong January 2009 (has links)
Since the discovery of nanomaterials in early ninety’s, a remarkable progress in the synthesis of nanocomposites has been reported looking for a new better material with improved physical and chemical properties for a variety of applications in almost all fields. The science and technology of nanocomposites has created great excitement and expectations in the last decade too. In addition to that, researches in this area have been focusing on the nanoscale second phase embedded in the polymeric matrix that gives physical and chemical properties that cannot be achieved by ordinary material synthesis methods. Researchers have also discovered that incorporating the right amount of nanoparticles into a polymer matrix pose a remarkable strength and flexibility and that industries should be able to integrate the outcome of their researches widely in high performance applications in the field of biomedical engineering, aerospace, marine, high speed parts in engines, packaging and sports gadgets. With the new methods of synthesis and tools for characterisation, nanocomposite science and technology is now experiencing explosive growth. Taking advantage of the need and the properties of the nanomaterials, through this research a new nano-enhanced composite is developed through addition of nanofiller into epoxy matrix to cater for varied applications. The physical and mechanical properties of the identified nanomaterial reinforced polymer composite were characterised by experimentation in order to ascertain the improvement in tensile, compressive and flexural properties as well as the adhesion of the matrix to the substrate. Also, while addressing potential enhancements like improved mechanical strength, better dimensional stability, higher thermal stability, better abrasion resistance, hard and wear resistance, better chemical properties like better flame retardance, anticorrosive and antioxidation, adequate importance was given to easy and bulk processability and most importantly the commercial viability as well. This nano-enhanced nanocomposite was then optimised. Based on these results, it has been established that epoxy reinforced with 1% percent of nanoclay can significantly improve the mechanical properties without compromising the weight or processability of the composite. Thus, a futuristic and much promising nano-enhanced epoxy composite has been successfully made ready for commercialisation.
76

Enhancing Diabetes Self-Management: Motivational Enhancement Therapy

Britt, Eileen Frances January 2008 (has links)
The effectiveness of Motivational Enhancement Therapy (MET), a brief four session form of Motivational Interviewing (MI), provided by diabetes health practitioners at a hospital-based clinic, in improving diabetes outcome and self-management of Type 1 and Type 2 diabetes was evaluated using quasi-experimental designs (i.e., non-random control group and multiple baseline designs). Study 1 evaluated if MET provided by Diabetes Nurse Educators (DNEs) was effective in improving diabetes outcome (i.e., blood glucose and lipids) and diabetes self-management, and compared its effectiveness to the current standard treatment which comprised Patient Education (PE). Study 2 evaluated if the results of Study 1 could be generalised to Dietitians providing the intervention. Study 3 evaluated the effects of MI training and post-training supervised practice on practitioner and patient behaviour. Specific hypotheses (Studies 1-2) were that MI would lead to improved diabetes outcome through improved diabetes self-management, and would be more effective than PE. Further, training in MI plus supervised practice was predicted to lead to Nurse Educators behaving in ways consistent with MI and as a result the participants would exhibit less resistance and increased change talk than participants receiving PE (Study 3). The results suggest that MET was well received by the participants, and contributed to improved diabetes outcome (e.g., lowered blood glucose) and diabetes self-management (e.g., self-monitoring of blood glucose and dietary compliance), and may have been more effective than PE, although high variability made conclusions uncertain. Evidence of generalisation across participants, intervention staff, and outcomes is provided. Additionally, evidence is provided that with two days training plus supervised practice the DNE were able to practice MET to at least a beginning level of competency in MI and that as a result the participants behaved in ways consistent with MI theory (i.e., showed less resistance and increased change talk).
77

Brief inpatient treatment for eating disorders: can Motivational Enhancement Therapy improve outcome?

Dean, Helen Yasmin January 2007 (has links)
Doctor of Clinical Psychology / Master of Science / Despite a number of different psychotherapeutic approaches having been examined for use with patients with eating disorders, there is still no established psychological treatment associated with acceptable levels of long-term recovery. These poor recovery rates are associated with the observation that eating disorder patients are often ambivalent, or even resistant, to treatment. As such, research has begun to explore the use of Motivational Enhancement Therapy (MET), a treatment approach that aims to engage ambivalent and change resistant patients in the treatment process, with these individuals. Poor motivation to recover is particularly prominent within the inpatient eating disorder setting. However, no previous study has examined the use of MET to foster willingness to engage in treatment with this group of patients. The objectives of the current study were twofold. Firstly, an examination of the effectiveness of an inpatient eating disorders unit affiliated was undertaken in order to further the research base upon which future inpatient interventions can be built and compared. The second objective was to develop and evaluate a brief MET group program for inpatient eating disorder sufferers. The goal of the intervention was to enhance patients’ motivation to more effectively utilise the inpatient program and to hence positively impact upon their psychological, physical and behavioural functioning. Forty-two consecutive inpatients meeting DSM-IV criteria for an eating disorder were recruited into the current study and sequentially allocated to groups. Twenty-three inpatients completed four MET groups in addition to routine hospital care. A control group of 19 participants in the standard hospital treatment program was also employed (TAU group). The inpatient unit was associated with significant improvements on a number of physical, behavioural and emotional outcome measures. Despite no significant differences between the MET and the TAU groups being found on the overall formal outcome measures, there were nevertheless differences between the groups. Specifically, the MET groups appeared to foster longer-term motivation and engagement, and to promote treatment continuation. This study hopes to start a constructive debate on the role of MET in the inpatient eating disorders unit.
78

Enhancement in Indium Incorporation for InGaN Grown on InN Intermediate Layer

Hartono, Haryono, Chen, P., Fitzgerald, Eugene A., Chua, Soo-Jin 01 1900 (has links)
InN has been grown on GaN with a thin intermediate layer of InGaN by metalorganic chemical vapor deposition (MOCVD) to further enhance indium incorporation in subsequent InGaN layer. Trimethylindium (TMI) and ammonia (NH₃) were used as the source for InN growth and transmission electron microscopy (TEM) confirmed the presence of pyramid-like structure of InN. A layer of InGaN subsequently grown on top of these InN pyramids shows a red-shift of ~20 nm relative to InGaN layer grown directly on GaN using the same growth condition. However, there is no significant pits reduction. An alternative method to enhance indium incorporation is to grow the InN by adding a small amount of trimethygallium (TMG) into the TMI and NH₃ flow. This method provides a seed layer for the InN growth and it gives a higher density of InN pyramids. X-ray diffraction (XRD) measurement of this sample shows a high indium incorporation to give InGaN with x~0.26 as compared to x~0.22 for sample grown without TMG flow in the InN layer. / Singapore-MIT Alliance (SMA)
79

Visualisierung von myokardialem Narbengewebe mittels MRT bei Patienten mit korrigierter Fallot-Tetralogie

Boegershausen, Kai 04 January 2016 (has links) (PDF)
Die Fallot-Tetralogie ist ein angeborener Herzfehler, der sich aus der Kombination von vier verschiedenen anatomischen Fehlbildungen zusammensetzt. In der Diagnostik kommen bevorzugt die Echokardiografie und die Magnetresonztomografie (MRT) zum Einsatz. Die MRT stellt dabei bei der Erfassung volumetrischer Parameter, insbesondere beim echokardiographisch nicht immer vollständig einsehbaren rechten Ventrikel, den Goldstandard dar. Zudem bietet die MRT die Möglichkeit der Gewebecharakterisierung, inklusive der Darstellung von myokardialer Fibrose. In dieser Studie wurden 67 Patienten nach korrigierter Fallot-Tetralogie mittels MRT untersucht. Dabei lag der Schwerpunkt auf der Visualisierung und Quantifizierung der myokardialen Fibrose mittels Delayed Enhancement-Technik in beiden Ventrikeln. Ziel war es, die Prädilektionsstellen von Delayed Enhancement nach Korrektur einer Fallot-Tetralogie zu beschreiben und seine Beziehung zum Auftreten von ventrikulären Arrhythmien und weiteren kardialen und anamnestischen Parametern zu ermitteln. Es stellte sich heraus, dass Delayed Enhancement bevorzugt im rechten Ventrikel zu finden ist. Es konnte kein Zusammenhang mit dem Auftreten ventrikulärer Arrhythmien, zum Patientenalter während der Korrektur-Operation sowie zu volumetrischen- und Ergometriedaten hergestellt werden. Das Auftreten ventrikulärer Arrhythmien war jedoch signifikant abhängig sowohl vom Patientenalter zum Zeitpunkt der Korrektur-Operation als auch vom Patientenalter zum Zeitpunkt der MRT-Untersuchung.
80

Efforts to improve latent fingerprint impression processing using fluorescent and colored superglues

Costley, Destiny 22 January 2016 (has links)
The use of cyanoacrylate (CA) as a fuming technique for the development of latent friction ridge skin impressions has been widespread for decades within the forensic lab as well as in the field at crime scenes. Important features of processing latent print impressions using this method include that it makes visible latent print impressions that for the most part cannot be seen with the unaided eye and it preserves latent print impressions for future processing/examination. The superglue fumes "fix" the latent print impression to the substrate making it difficult to wipe away, thereby decreasing the chances of destruction during packaging at the scene, transportation, and processing in the lab. One of the disadvantages to this technique is the lack of contrast between the white polymers that are formed on the latent print impression residue and light colored backgrounds on which the latent print impression may be present. Attempts were made to develop a one-step cyanoacrylate fuming method that would enhance visualization of latent print impressions on light colored backgrounds without the need for an alternative light source, dye staining, or powdering. Latent print impressions were applied to black and white ceramic tiles, white painted wood and white/translucent textured plastic. Protein and hemoglobin stains, commercial colorants, sublimation dyes, hair dye, and printer ink were added to ethyl-CA in an attempt to create a co-polymerization process of the vaporized cyanoacrylate monomers and colorant molecules on latent print residue. Fuming was also attempted using pre-colored commercial glues with the assumption that the attached CA polymers on the latent print impression residue would retain their original color properties. None of these methods proved successful. The practical use of a new fluorescent CA, Lumicyano^TM, was also examined. Following fuming, an ALS is utilized for the excitation of the developed latent print impressions using this technique. Strong fluorescence could not be observed on all substrates. In this particular study, fuming with traditional CA followed by the application of powder or dye stains to latent print impressions currently appears to be the most efficient technique for latent print enhancement on the white or light colored substrates used in this study.

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