A simulation algorithm is proposed in this thesis to investigate the effects of lensed fiber parameters on the variation of radius of curvature of the melted lens and the coupling efficiency of butterfly type laser diode transiver module. Two different endface shapes, i.e. the taper and the conical-wedge type lensed fibers, will be studied. The effect of endface shapes, sizes, and the melting zone volume on the coupling efficiency of lensed fibers are simulated and discussed. In the study on the conical type lensed fiber, the MARC¡¦s elastic-plastic-thermal finite element model is employed to simulate the melting and the solidification processes at the fiber tip endface with different conical angles. The temperature dependent material properties are used to calculate the melting zone and the post-melten deformation during the heating process. The Surface Evolver Software has also been employed to simulate the solidified lens shapes. The variation of radius of curvature of the tip lens is analyzed. The ZEMAX optical analysis software is applied to explore the relation between the coupling efficiency and the distribution of the radius of curvature. The variation of laser signal coupling efficiency introduced from different conical lensed fibers is simulated numerically. A good agreement between the published measured data and the simulated results indicate the proposed simulation model is feasible. The effect of endface shape and molten zone size on the conical wedge type lensed fiber has been studied in a similar way. The coherence between the shape of solidified elliptical lens at fiber tip and the coupling efficiency for the 980nm LD will be explored. Different endface shapes will also be investigated by using the simulation model proposed previously. Different aspect ratio of the conical-wedge type tip will be introduced to compensate the elliptical LD ray model and to recover the coupling efficiency loss. The agreement between the results simulated using the proposed model and the measured data is examined. The simulated results indicate that the coupling efficiency of a butterfly type laser diode transever can be improved significantly by controlling the shape of the lens introduced in this type lensed fiber. The optimal grinding parameters and the melting parameters used to fabricate the lensed fibers will also be studied. The effects of the shape parameters, i.e. the conical taper angle, the wedge angle and the size of molten zones on the curvature variation of the lens will also be studied. A better understanding about the design and fabrication of the lensed fiber of a laser diode based transever module is expected from the results presented in this thesis.

Pigs, mice and human beings are all vertebrate mammals. More than 90% of genomes in pigs and mice are the same as human beings. Experiment pigs and mice are with advantages in purebloods, small size, high reproductive capacity and short life cycle, etc. The tissue structure and metabolism of physiology in pig and mice are similar to human as well. Therefore, laboratory pigs and mice are often used to substitute human beings for biomedical engineering test. The research topics of this thesis are in the area of biomechanical properties of bones in mammal. The objectives of the study are to reveal the biomechanical properties of various types of bones and discuss its implication to human development. The entire thesis is divided into three parts. The first topic used micro-indentation test and FEM analysis for the determination of biomechanical properties of controlled cartilages in pigs. The second topic applied (a) three-point-bend failure test to study the age-related radius strength in mice, (b) tensile test to study the mechanical response of cranial sutures in mice, and (c) optical interferometry for 3D profile determination of mouse cranium. The third topic is for quantitative analysis of patterns in cranial sutures using DFT (Discrete Fourier Transform). The mechanism of diseases (such as osteoporosis, craniosynostosis, etc.) and the complexity of patterns in human cranial sutures in different age groups are discussed.

Configuration-bias Monte Carlo simulation is used to investigate the structural property of liquid crystal. Our results show that the surface molecules of the smaller nanoclusters are formed the helical structure, In addition, the morphologies of nanoclusters show a tube-like structure when the surface molecules formed the helical structure; however, as the surface molecules do not form the helical structure, the morphologies of nanoclusters become a ball-like structure. For the tube-like structure, because of the configurations of nanoclusters are simpler, the nanoclusters will show an order structure. In the case of the ball-like structure, the molecules will attract with others, so the nanocluster reveals an ordered structure at local area. According to the result of the averaged order parameters, as the averaged order parameter larger than 0.5, the configuration of nanocluster will be a tube-like structure, while as the averaged order parameters smaller than 0.5, the configuration of nanocluster will form a ball-like structure.

published_or_final_version / Medical Sciences / Master / Master of Medical Sciences

Purpose: To evaluate the course of recovery in fall-risk and functional status over the first year following a distal radius fracture (DRF), and evaluate differences in fall and fracture risk factors in women over the age of 50 years with a DRF compared to their non-fractured peers. Methods: Two cohorts of participants volunteered in two sub-studies of the thesis. The first was seventy-eight women recruited from a DRF Clinic within the first week after their fracture, and followed up in concert with standard clinic appointments at week three, nine, 12, 26, and 52 post-fracture. The second cohort consisted of women aged 50 years or older, with and without a recent distal radius fracture, being at least 6 months post-DRF, but no more than 2 years post-fracture. Seventy-seven women age 50-78 with (Fx, n = 32) and without (NFx = 45) a history of DRF were assessed on two occasions within 4 weeks apart using a battery of fall and fracture risk tools, including balance, mobility, gait speed, fracture risk assessment, as well as bone quality assessment using peripheral quantitative computer tomography (pQCT) and dual x-ray absorptiometry (DXA). Results: Fall-risk status (strength, balance, mobility) gradually improved over the first year post-fracture, with balance confidence remaining high even immediately post-fracture. In the second study, women with a recent DRF, compared to women without, demonstrated higher fall and fracture risk. Women with a recent DRF had lower bone and muscle strength in both the upper and lower extremities compared to the non-fractured controls, with no differences in DXA derived aBMD at the femoral neck or spine. Significance of findings: The results of these studies will help clinicians understand the normal course of functional recovery post-fracture, and assist in determining appropriate fall risk assessment and interventions for post-menopausal women at risk of fragility fracture. Results demonstrate the importance of studying women at risk of DRF as an important first indicator of bone fragility and risk of future fracture. These findings also strengthen the notion that DXA alone may not be the best predictor for fracture risk.

published_or_final_version / Orthopaedic Surgery / Master / Master of Philosophy

Stipinkaulio lūžiai – tai vieni iš dažniausiai pasitaikančių lūžių suaugusiems. Šie lūžiai sudaro 10-15% visų lūžių. Nustatyta, kad per visą gyvenimą iš dešimties maždaug du ��monės patiria lūžius. Dėl lūžio sutrinka pirštų, plaštakos, dilbio ir iš dalies – visos rankos judėjimo funkcija. Šio darbo tikslas – įvertinti ergoterapijos poveikį ligoniams, patyrusiems stipinkaulio lūžį. Darbo uždaviniai: 1. Įvertinti plaštakos funkciją ligoniams, patyrusiems stipinkaulio lūžį, 2. Įvertinti ligonių savarankiškumą patyrus stipinkaulio lūžį, 3. Įvertinti ergoterapijos poveikį šių ligonių rankos funkcijos ir savarankiškumo pagerinimui. Tyrimas buvo atliktas Všį Kauno Kalniečių poliklinika. Tirti asmenys, patyrę stipinkaulio lūžius. Tyrime dalyvavo 100 ligonių. Ligoniai buvo suskirstyti į dvi grupes: pirmą ir antrą po 50 ligonių. Pirmą grupę sudarė ligoniai, patyrę dešinės rankos stipinkaulio lūžį. Antrą – ligoniai, patyrę kairės rankos stipinkaulio lūžį. Abiejų grupių ligoniams buvo sudaryta ir taikyta individuali ergoterapijos programa, atsižvelgiant į rankos funkcijos ir savarankiškumo sutrikimą. Ergoterapijos poveikiui įvertinti buvo naudojama: šiam tyrimui paruoštas klausimynas, plaštakos jėgos matavimas dinamometru, plaštakos funkcijos matavimas goniometru, skausmo ir sustingimo vertinimas, funkcinis judėjimo testas (Modifikuotas Keitelio indeksas), funkcinio nepriklausomumo testas (FNT). Tyrimo išvados: 1.Įvertinus plaštakos funkciją ligoniams, patyrusiems stipinkaulio lūžį, buvo... [toliau žr. visą tekstą] / Radius fractures – are one of the most likely to occur fractures for adults. From all fractures they include from 10 to 15 % of all fractures. It is examined that through whole life, two persons of ten sustain these fractures. Due to fracture fingers, hand, forearms and in part – whole hands, function becomes irregular. Aim of this work is to estimate occupational therapy influence to patients, experienced radius fracture. Tasks of this work is: 1. Evaluate patients hand function, who are experienced spoke-bone fracture, 2. Evaluate patients independence after this fracture, 3. Evaluate occupational therapy effect to these patients hand function and self-care improvement. Research was made at Všį Kauno Kalniečių clinic. Examined people had radius fracture. There were analyzed hundred patients. They were separated into two groups: first and second, both with 50 patients. First group patients had right hand spoke-bone fracture. Second – patients with left hand spoke-bone fracture. To all patients from both groups was adjusted and applied individual occupational therapy programs considering their hand function and autonomy disorder. In order to estimate impact of occupational therapy was used: specially for this research prepared questionnaire; hand strength was measured with dynamometer; hand function was measured with goniometer; also it was evaluated pain and rigor; patients were examined with function movement test (Modified Keitel index) and functional independence... [to full text]

This thesis presents the application of topology to machining at the micro and macro levels through an experimental study, modeling and analysis. Uncoated carbide tools of four different cutting edge radii and four different feed rates are used to perform orthogonal machining on AISI 1045 steel disks. The study analyzes the cutting forces, changing grain boundary parameters, micro-hardness, temperature and correlates them to the residual stresses that hold a key to the product life. This analysis helps to understand and evaluate the aspects of grain boundary engineering that influence the fatigue life of a component. The two components of residual stresses (axial and circumferential) are measured, and are correlated with the different cutting edge radii and feed conditions. A topology-based modeling approach is applied to study and understand various outputs in the machining process. The various micro and macro topological parameters that influence the machining process are studied to develop a model to establish the effects of topological parameters in machining using Maple program.

Thesis (M.S.)--University of Missouri-Columbia, 2007. / "August 2007" The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Includes bibliographical references.

Thesis (MSc.(Anatomy)--Faculty of Health Sciences)-University of Pretoria, 2008. / Summary in English and Afrikaans. Includes bibliographical references.