Pengaruh Sudut dan Jari-Jari Saluran Menikung terhadap Konsentrasi Aliran Sedimen Suspensi arah Transversal

The change in channel dimension has a great effect on the flow hydraulic parameters. Likewise, the angle and radius of the bend are not the same will also affect the concentration of suspended sediment flow. To determine the effect of angle and radius of the bend, the measurement of susupended sediment concentration was done at 4 (four) location in Mataram irrigation channel curve. The four locations describe 2 channels having relatively the same angle but having different radius, and 2 (two) channels having the same relative radius but having different angles. Measurement of suspended sediment concentration in tranversal direction is done some depth point used by opcon probe. The results of the research for different angle of bend shows that from the interance to the end of the channel bend so the trend of suspended sediment concentration value are decreases. After the end of the channel bend started there is no more the angle influenced, the trend value of suspended sediment concentration are constant. As for the different radius, the value of suspended sediment concentration is still relatively the same and there is no change significantly. This shows that the relation or influence between the length of the radius of the bend with the value of the suspended sediment concentration is not visible

EXTENDED FOLDY–LAX APPROXIMATION ON MULTIPLE SCATTERING

The Foldy–Lax self-consistent system has been widely used as an efficient numerical approximation of multiple scattering of time harmonic wave through a medium with many scatterers when the relative radius of each scatterer is small and the distribution of scatterers is sparse. In this paper, an “extended” Foldy–Lax self-consistent system including both source and dipole effects as well as corrections due to the self-interacting effects will be introduced, in which the scattering amplitudes and the corrections are determined as powers of the small scaled radius. This new approach substantially improves the accuracy of the approximation of the original Foldy–Lax approach.

RELATIVE DISTANCE: THE KEY TO THE SHAPE OF HEPATIC BUILDING BLOCKS

The delineation and the shape of the smallest structural units of the liver is still the subject of debate. However,the blood flow from an upstream terminal branch of the portal vein to a downstream central vein is thought to induce a functional zonation in hepatocyte gene expression. This property was used to determine boundary conditions for the shape of the hepatic building blocks. Histochemical techniques that specifically label periportally or pericentrally expressed enzymes can be used to distinguish periportal and pericentral areas in a liver section. Pairs of images from aligned serial sections, one stained for a portal and the next for a central enzyme, are used. Segmentation and skeletonisation of these images results in the skeletons of the portal and central areas. Distance transformation with respect to these skeletons gives for each point in the image pair the distance to the nearest terminal branches of the portal vein and the central vein. For each point the relative position on the porto-central radius can then be calculated as its distance to a portal vein divided by the sum of its portal and its central distance. In the resulting relative radius image, the area occupied by 'zones' of equivalent relative radius can be measured. According to the principle of Delesse the relative area of a zone in the image is equal to the relative volume of that zone in the tissue. For structural units of plate-like, cylindrical or spherical shape, the relative volume of a zone is equal to the relative radius of that zone to the power 1, 2 or 3, respectively. Thus, the exponent in the relative area - relative radius relation gives information on the shape of the structural unit. Measurement of the areas of each relative radius zone and determination of the area - radius relation in images of random sections of adult mouse liver results in an exponent of 1.1. This suggests that the smallest structural unit of the mouse liver has the shape of a needle.

Surface Failure and Durability of Induction-Hardened Sintered Powder Metal Rollers and Gears with Various Hardened Depths

In this report, the effect of hardened depth on failure modes and fatigue strengths of induction-hardened sintered powder metal rollers and spur gears was elucidated, including the effect of relative radius of curvature of the rollers. These experimental results were discussed by an amplitude of ratio of orthogonal shear stress to Vickers hardness. Failure mode of the rollers was spalling due to subsurface origin crack with slight micropits and that of the gears was pitting with spall near the pitch point independent of the hardened depth. The depths of spalling cracks agreed almost with the occurring depths of peak amplitude of the ratio of orthogonal shear stress to Vickers hardness. Surface durability of the test rollers increased as the surface hardness increased and the relative radius of curvature decreased. Surface durability of the test rollers and the test gears was hardly influenced by the hardened depth.

Surface Failure and Durability of Induction-Hardened Sintered Powder Metal Rollers and Gears With Various Hardened Depths

In this study, the effect of hardened depth on failure modes and fatigue strengths of induction-hardened sintered powder metal test rollers and spur gears is elucidated also with the effect of relative radius of curvature of the test rollers. These experimental results are discussed by an amplitude of ratio of orthogonal shear stress to Vickers hardness. Failure mode of the test rollers was spelling due to subsurface origin crack with slight micropits and that of the test gears was pitting due to surface origin crack with spall near the pitch point independent of the hardened depth. The depths of spalling cracks agreed almost with the occurring depths of peak amplitude of the ratio of orthogonal shear stress to Vickers hardness. Surface durability of the test rollers increased as the surface hardness increased and the relative radius of curvature decreased almost independent of the hardened depth. Surface fatigue life of the test gears was hardly influenced by the hardened depth.