116 research outputs found
Resonant Frequency Characteristics of a SAW Device Attached to Resonating Micropillars
Recently we reported experimental and simulation results on an increase in resonance frequency of a SAW resonator caused by mass loading of micropillars made of SU-8, attached normal to the surface of the resonator. We concluded that SAW resonator and the SU-8 micropillars in unison form a system of coupled resonators. We have now extended this work and performed a finite element method simulation to study the resonance frequency characteristics of the SAW-based coupled resonator. In this paper we report the effect of the resonance frequency of the micropillars on the resonance frequency of the system of coupled resonators, and observe the coupling of micropillar resonance and the propagating SAW as described in the well known Dybwad system of coupled resonators
Damping of giant resonances in asymmetric nuclear matter
The giant collective modes in asymmetric nuclear matter are investigated
within a dynamic relaxation time approximation. We derive a coupled dispersion
relation and show that two sources of coupling appear: (i) a coupling of
isoscalar and isovector modes due to different mean-fields acting and (ii) an
explicit new coupling in asymmetric matter due to collisional interaction. We
show that the latter one is responsible for a new mode arising besides
isovector and isoscalar modes.Comment: Varenna conference proceeding
Intraoperative embolism or type I hypersensitivity reaction to gelofusine®
Despite rare reports of Type I Hypersensitivity reactions (anaphylaxis) to colloid plasma expanders, they find wide application during resuscitation and major surgeries. We present the case of a possible Type I hypersensitivity reaction to Gelofusine® in a 42-year-old female patient during oncological surgery. The delayed manifestation caused some diagnostic confusion with an embolic event. The patient was symptomatically treated and the rest of the surgery was completed uneventfully. A high index of suspicion is vital for prompt identification and treatment of anaphylaxis
Continuum of Care Services for Maternal and Child Health using mobile technology – a health system strengthening strategy in low and middle income countries
Intraurethral Catheter: Alternative Management for Urinary Retention in Patients With Benign Prostatic Hypertrophy
A polyurethane intraurethral catheter (IUC) was used in 27 patients with benign prostatic hypertrophy who were unfit for surgery, or were awaiting surgery. All of them had previously had a periurethral catheter inserted. The IUC was inserted with a cystoscope under fluoroscopic control. Spontaneous voiding through the IUC resumed in 25 patients (93%) in the immediate postprocedure period. At the end of 6 months follow-up, the peak flow rates and the residual volumes estimated in 22 patients were satisfactory. Immediate complications included incontinence due to distal displacement in 2 patients and hematuria in one patient; long-term complications included mild encrustation of the IUC in 2 patients and calculus formation on the IUC in 1 patient. None of the patients had clinically significant urinary tract infection. The presence of the IUC did not compromise the subsequent transurethral resection of the prostate gland. We recommend the use of an IUC for up to 6 months in patients with urinary retention who are awaiting surgery or are unfit for surgery as an alternative to an indwelling urethral catheter
Optimal Investment Strategy for Energy Performance Improvements in Existing Buildings
Current global efforts for energy conservation and optimization are focused on improvements in energy supply and production systems, and on encouraging the adoption of energy-efficient devices and equipment. However, systematic assessments of economic and technical implications when adopting energy-efficient alternative systems in buildings have not yet been explored thoroughly. The uncertainty about the consequences of investing in alternative energy-efficient systems has led to a prolonged utilization of obsolete building systems (underperforming HVAC systems, inefficient lighting systems, badly maintained and equipment, and so forth). This has led to overall poor energy efficiency, creating considerable burden on the building operation budget.
This research discusses the procedure for formulating an investment strategy to improve existing building energy performance. The approach is suitable for large building portfolios where a plethora of potential refurbishment interventions can be considered. This makes our approach especially suited for use on university campuses and most of this report will focus on that particular application utilization protocols especially for use on campuses. This investment model only looks at the energy related savings versus investments; it is well understood that the ultimate selection of the optimal set of improvement options of a portfolio will be determined by additional considerations, such as overall value, occupant satisfaction, productivity improvements, aesthetics, etc. Nevertheless, many campus managers are confronted with the question how much energy they can save with a given investment amount. This is exactly what our approach helps to answer.
The investment optimization strategy is implemented in software "InvEnergy," which systematically calculates the costs and benefits of all possible building-technology pairings, taking uncertainties in the saving/investment calculations and estimates into account. This tool empowers decision makers in facility management to make complex investment decisions during continuous building commissioning.M.S.Committee Chair: Castro-Lacoutore, Daniel; Committee Co-Chair: Augenbroe, Godfried; Committee Member: Mobley, Linda Thoma
DIFFEOMORPHIC TRANSFORMATIONS FOR AUTOMATIC MULTI-MODALITY IMAGE REGISTRATION
Image registration is usually the first step before performing any post-processing operations such as surgical planning, volumetric measurements, diagnosis, etc. There are numerous registration algorithms that use any of several geometric interpolants to warp images. The deformation can be modeled by a suitable parameterization of the interpolant, through a uniform grid placement of control points or adaptively, where control points are only placed where images are misaligned. Nonparametric approaches do not use control points at all, e.g., fields regularized by elastic constraints. There are two main challenges in control point based approaches: the choice of deformation model and the method of parameterization. While some transformations focus on modeling local changes, some on continuity and invertibility, there is no closed-form nonlinear parametric approach that satisfies all these properties. This dissertation presents a class of nonlinear transformations that are controllably local and continuous, and invertible under certain conditions. They are straightforward to implement, fast to compute and can be used as alternatives to splines and radial basis functions. The second challenge is the method of parameterization, that is, the location and scale at which control points are placed. Poor choice of parameterization results in deformations not being modeled accurately or over-parameterization, where control points may lie in homogeneous regions with low sensitivity to cost. This lowers computational efficiency due to high complexity of the search space and might also provide transformations that are not physically meaningful, and possibly folded. This dissertation proposes a method to find mismatched locations in images and the spatial scale at which they are misregistered. Mismatch is specified based on location and smooth spatial scale (mismatch vector) at which local joint entropy is high. First we show that mismatch vectors found by our method are in good agreement with known deformations applied to synthetic images. Next we use these attributes to parameterize our iterative registration method to demonstrate registration performance. The result is a completely automatic multimodality registration algorithm that achieves high accuracy of alignment (voxel sized errors) for the registration of brain structures in MR images.Ph.D.Applied SciencesBiomedical engineeringElectrical engineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/126520/2/3253366.pd
- …