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The objective of this study was to compare the effects of postoperative pain following ovariohysterectomy via harmonic scalpel assisted laparoscopy (HALO) and traditional ovariohysterectomy (OVH) in dogs. The study was designed as a randomized, blinded, prospective study. Sixteen, purpose-bred, intact female, Beagle dogs were used to complete the study. Dogs were placed into two groups. Group 1 included (8 dogs) that underwent ovariohysterectomy via HALO. Group 2 included (8 dogs) that underwent ovariohysterectomy via traditional OVH. Physiologic data, abdominal nociceptive threshold scores, and University of Melbourne pain scores (UMPS) were recorded at 2, 6, 12, 24, 48, and 72 hours following surgery. Blood samples for plasma cortisol, glucose, and creatine phosphokinase (CPK) were taken at the time of the incision and 2, 6, 12, 24, 48, and 72 hours following surgery. No significant surgical complications were encountered in either group. The HALO mean surgical time was significantly longer (55.7 minutes) than the traditional OVH (31.7 minutes). No significant differences were observed between the two groups for the pain measures of heart rate, respiratory rate, temperature, CPK, and glucose. The OVH group had significantly higher mean plasma cortisol levels at hour 2 following surgery than the HALO group (P=0.0001). The mean UMPS were significantly higher in the OVH group than the HALO group at all postoperative times (P=0.0001). Mean nociceptive threshold measurements revealed significantly higher tolerated palpation pressures in the HALO than the OVH group at all postoperative times, except hour 72 (P=0.0002). Dogs in this study appeared to be less painful with HALO procedures versus traditional OVH. The harmonic scalpel coagulated ovarian and uterine vessels completely with minimal collateral damage to surrounding tissues. The clinical relevance of this study demonstrates that harmonic scalpel-assisted laparoscopic ovariohysterectomy is a safe alternative to traditional OVH and offers a minimally invasive and less painful method of surgery. / Master of Science

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Harmonic distortion in a power system can excite non-characteristic harmonics from converter interfaced loads and generators which can then propagate back into the system, exciting other harmonics in the system. In this thesis, a harmonic analysis tool is presented that is designed to perform high accuracy, computationally efficient, steady-state harmonic analysis of distribution systems when multiple converter interfaced loads and generators exist in the system. The harmonic analysis tool requires less detail and engineering time than PSCAD/EMTDC while offering reliable assessment of harmonic coupling problems that are not captured by existing frequency-domain harmonic analysis tools. To do this, 5 harmonic models of common power electronic converter topologies were developed and implemented into this tool. The harmonic models are shown to be highly accurate; when tested in an unbalanced system with even and odd harmonic distortion, the harmonic models showed a maximum error of less than 0.4% when compared to PSCAD/EMTDC.

Harmonic distortion in a power system can excite non-characteristic harmonics from converter interfaced loads and generators which can then propagate back into the system, exciting other harmonics in the system. In this thesis, a harmonic analysis tool is presented that is designed to perform high accuracy, computationally efficient, steady-state harmonic analysis of distribution systems when multiple converter interfaced loads and generators exist in the system. The harmonic analysis tool requires less detail and engineering time than PSCAD/EMTDC while offering reliable assessment of harmonic coupling problems that are not captured by existing frequency-domain harmonic analysis tools. To do this, 5 harmonic models of common power electronic converter topologies were developed and implemented into this tool. The harmonic models are shown to be highly accurate; when tested in an unbalanced system with even and odd harmonic distortion, the harmonic models showed a maximum error of less than 0.4% when compared to PSCAD/EMTDC.

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No description available.

In this study we demonstrate the use of third harmonic (TH) and second harmonic (SH) generation in imaging dental sections. Teeth are the hardest and most indestructible part in human body. The TH and SH greatly facilitate observation of porous structures and collagen within the dental sections, respectively. Strong SH has been found on various biological specimens, such as collagen, potato starch, and skeletal muscles. These materials all possess periodical nano-structures that are often referred as (nonlinear) bio-photonic structures. In particular, collagen is an extra-cellular structural protein and is a major component of bone, cartilage, skin, and other tissues. Collagen fibrils have a triple-helical structure and it is believed that this structure enables collagen to generate SH signal from a wide range of wavelengths in the infrared region. For comparison, microtubule structures within dentin, due to its large index mismatch with surrounding, can be clearly seen with THG imaging. The THG also facilitate observation of prismatic structures in enamel. The successful construction of a multi-photon laser scanning microscope that can operate in both reflection and transmission modes is the key for this study. A femtosecond, sync-pumped optical parametric oscillator (OPO) is used to generate second and third harmonics from dental sections. Dental sections have large index of refraction¡]n~1.68¡^and scatter visible light severely. The employment of excitation wavelength at 1260 nm greatly reduces scattering and absorption within the sample. Its corresponding SH and TH wavelengths are at 630 nm and 420 nm, respectively. Additionally, 3-D structural views are also reconstructed from the optically sectioned images by the use of specialized 3D image processing software.

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