Model Test about Reflection Coefficient for Perforated Wall Caisson according to Perforated Wall Shapes: Single Chamber Open Slit Caisson

In this study, the hydraulic model tests for the single chamber perforated wall caisson were performed to investigate the reflection coefficients according to the slit shapes. The perforated wall with vertical and horizontal slits was applied to the tests. The random waves were used for the test by using Bretschneider-Mitsuyasu frequency spectrum. The similar reflection coefficients were measured in the vertical and horizontal slit caisson within a similar perforation ratio and area. The reflection coefficient according to relative slit length(S/Hs) was analyzed and the minimum reflection coefficients were measured in relatively small S/Hs (=2.7). The results from horizontal slits showed similar trends with those from the vertical slit perforated wall.

Free Convection in a Vertical Slit Micro-channel with Super-hydrophobic Slip and Temperature Jump Conditions

The main objective of the convective incompressible fluid flow placed in a magnetic field, with vertical motion through an isothermally heated porous channel. The Super-hydrophobic the slip was applied on one wall along with temperature jump, while there is no slip on another wall. The analytical results are discussed qualitatively for the parameters which were on the mathematical formulation on the basis of the model equations designed for the linear momentum and energy balance. Decreasing the value of the slip parameter is noticed due to decreasing in temperature. The effects of heat source and porous medium on the micro channel flow is analysized in detail. Coparesion of current results is made with the earlier work. The effect of Dray parameter is to increase the fluid velocity in the channel.

‘Van Herick Plus’: a modified grading scheme for the assessment of peripheral anterior chamber depth and angle

AimTo evaluate the accuracy of a new, modified grading scheme involving a short vertical slit beam, at the inferior angle for peripheral anterior chamber depth (PAC) and angle estimation and its correlation with anterior segment optical coherence tomography (ASOCT).MethodsA cross-sectional study of consecutive phakic patients, above 40 years of age, was performed. Using a short, vertical slit beam not reaching the pupil, the inferior angle at the sclerolimbal junction was evaluated, photographed and assessed by a ratio of peripheral anterior chamber depth to peripheral corneal thickness (PAC:PCT) and iridocorneal angle (ICA) on ImageJ software. The inferior angle at the same meridian was also recorded on ASOCT.ResultsBased on the PAC:PCT ratio, the subjects were divided into four groups: I (<1/4), II (1/4-1/2), III (>1/2–1) and IV (>1). The clinically assessed angle by short vertical slit beam correlated well with ASOCT values, trabecular-iris angle (TIA) (r=0.918; p<0.001) and scleral spur angle (r=0.903, p<0.001). The mean difference between ICA and TIA on ASOCT was 0.7970; 95% limits of agreement:−5.7670 to 7.3610 (±1.96 SD). For angles graded narrow on ASOCT (TIA <200), using a cut-off of peripheral PAC:PCT <1/4, the area under the curve was 0.918 with a sensitivity of 85.2% and a specificity of 88.2%. There was good agreement between ImageJ parameters with those assessed subjectively on photograph of the slit beam examination by a glaucoma fellow (weighted kappa=0.74) as compared with a general ophthalmologist, where there was moderate agreement (weighted kappa=0.57).ConclusionA short, vertical slit lamp beam evaluation at the inferior angle is an easy and relatively accurate method for both peripheral anterior chamber depth and angle assessment. It correlated well with ASOCT and can be used as a more reliable screening tool to identify eyes with possibly occludable angles.