EFFECT OF TOPICALLY ADMINISTERED PROSTAMIDE AND PROSTAGLANDIN ANALOGS ON CENTRAL CORNEAL THICKNESS

Purpose: To determine if ocular treatment with topically administered prostamide or prostaglandin analogs can reduce central corneal thickness (CCT). Methods: We retrospectively analyzed the data of glaucomatous patients who had their CCT measured before and during monotherapy treatment with either latanoprost 0.05%, travoprost 0.004% or bimatoprost 0.03%. 62 patients were qualified for analysis. One eye of each subject was ran-

CENTRAL CORNEAL THICKNESS IN BLACK AND WHITE BRAZILIAN PA-TIENTS

Purpose: Considering the importance of central corneal thickness (CCT) in the IOP assessment and the lack of these data in a Brazilian population, this study was conducted to compare the corneal thickness of black and white patients in Brazil. Methods: A retrospective analysis was done and the of CCT of 24 black and 21 white Brazilian patients were compared. The CCT

A FOUR -WEEK COMPARISON OF BI-MATOPROST 0.03% AND BIMATOPROST 0.015% IN PATIENTS WITH ELEVATED INTRAOCULAR PRESSURE J.A. Ferreira, G.A.S.

Purpose: Intraocular Pressure (IOP) control is the main goal in glaucoma treatment However, despite satisfactory control, the occurrence of side effects reduces compliance. This study was designed to test if an ophthalmic preparation of 50% diluted bi-matoprost (bimatoprost 0.015%) achieves good IOP

INFLUENCE OF WATER DRINKING TEST ON CENTRAL CORNEAL THICKNESS

Purpose: To determine if there is an influence of the Water Drinking Test (WDT) on central corneal thickness (CCT) due to the sudden change of osmolarity since an increase on CCT could lead to a false higher IOP reading on applanation tonometry. Methods: 38 glaucomatous or glaucomatous suspect patients without ocular hypotensive medication were submitted to WDT. CCT was measured by ultrasound pachymetry before and

CENTRAL CORNEAL THICKNESS IN WHITE AND YELLOW PATIENTS IN BRAZIL

Purpose: To determine if there is a difference in central corneal thickness (CCT) of white and yellow Brazilian patients. Methods: We retrospectively compared the CCT data of yellow patients living in Brazil and white Brazilian patients. CCT was measured with an ultrasound pachymeter (Compuscan P Ultrasonic Pachymeter System model UPC 1000 ). One eye of each patient was randomly selected for statistical analysis. A two sample t

汽车用42V／14V转换器模块化技术设计方法

42V-14V汽车双电源结构为电力电子设备的大量使用提供了机会。为了满足这类市场一方面低成本,另一方面严格的温度和体积限制的要求,我们在不同的技术基础上提出了三种设计方法来构件42V/14VDC-DC变换器。这些设计方法都可用于大规模生产,但是都存在一个共同的限制:功率等级受限。因此必须将数个设备并联以达到所需的功率等级。我们进行了实际的设计并对它进行了评估。

ENERGY ESTIMATES FOR DELAY DIFFUSION-REACTION EQUATIONS

In this paper we consider nonlinear delay diffusion-reaction equations with initial and Dirichlet boundary conditions. The behaviour and the stability of the solution of such initial boundary value problems （IBVPs） are studied using the energy method. Simple numerical methods are considered for the computation of numerical approximations to the solution of the nonlinear IBVPs. Using the discrete energy method we study the stability and convergence of the numerical approximations. Numerical experiments are carried out to illustrate our theoretical results.

Design and Optimization of a GaN GIT Based PFC Boost Converter

The advent of GaN power devices brings the possibility of pushing up frequencies of power electronics system beyond the capacity of conventional Si counterparts.To harvest the high frequency operation benefits of GaN technology,not only GaN devices should be used optimally by providing proper switching and conduction conditions to best accommodate parasitic elements inherent with the devices,other components should also be capable of facilitating high frequency operation.In this paper,PFC boost converter is used as a platform to harvest the benefits of GaN technology and,at the same time,to uncover the limitations in pushing power electronics systems up.A 600W PFC boost converter with a maximum switching frequency of 3MHz is designed and implemented,which reached an average efficiency of 98.5%.The results indicate that,when properly used,a GaN PFC boost converter could operate at a frequency that is beyond the reach of conventional Si ones.As well,with availability of GaN devices,high frequency operation of power electronics systems is no longer limited by the lack of switching devices but by practical issues e.g.high frequency magnetic materials,high frequency controllers,etc.

Novel and Simple Calorimetric Methods for Quantifying Losses in Magnetic Core and GaN Transistor in a High Frequency Boost Converter

In design and implementation of a boost converter,information on loss characteristics of switching devices and magnetic materials is a prerequisite,especially in high frequency applications.To gather such information,testing and accurate loss quantification is needed.Previous methods for measuring magnetic core loss are either only suitable for sinusoidal wave excitations or cannot separate winding loss from inductor loss.In addition,existing loss measurement approaches on the newly introduced GaN transistors are not satisfactory.In this paper,we present a new method to distinguish winding loss from inductor loss under practical excitations.This method utilizes a converter to generate the actual excitation waveforms and uses a calorimetric setup to quantify the losses.By splitting up the inductor in a converter into an air-core inductor and a magnetic-core inductor,both equipped with exactly the same winding structure,the air-core inductor loss can be used as the reference of the magnetic-core inductor winding loss.In this way,losses in the magnetic core can be determined in the actual operating condition of a converter in which the inductor is to be used.Moreover,a simple calorimetric approach for obtaining loss information of GaN transistors are is also presented.Both methods require simple setup and are easy and convenient to execute.The methods work well in assessing different high frequency magnetic core materials and measuring losses in GaN transistors at 1MHz.