Skimming flows in stepped channels are systematically investigated under a wide range of channel slopes (5.7°⩽θ⩽55°). The flow conditions skimming classified into two regimes, and the hydraulic required to form quasi-uniform determined. An aerated depth is estimated from assumption that residual energy at end coincides with toe jump formed immediately downstream channel. In region, friction factor represented by relative step height slope. for slope θ=19° appears have maximum. formulated...

This paper presents topology optimization for thermal cloaks expressed by level-set functions and explored using the covariance matrix adaptation evolution strategy (CMA-ES). Designed optimal configurations provide superior performances in steady-state conduction succeed realizing invisibility, despite structures being simply composed of iron aluminum without inhomogeneities caused employing metamaterials. To design cloaks, a prescribed objective function is used to evaluate difference...

Abstract Stepped chutes effectively dissipate the energy of supercritical flow steep channels. In general, stepped chute flows are characterized by self-aeration. For their hydraulic design, it is important to know aerated depth, velocity, air concentration, and specific energy. Herein, quasi-uniform skimming systematically investigated over a range angles from 19° 55° for wide step heights discharges. Air concentration velocity profiles presented, depth-averaged friction factor determined....

In the study of independence quadratic quantities in a normal system Craig-Sakamoto's lemma is fundamental one m.We give here its simple proof, method which will also enable us short way to characterize distributed X 2 -distributions (Theorem 1) and obtain an analogous result for Wishart•s distributions 14).In Part I we investigate results related Cochran's theorem, Part•II extend so obtained case Wishart's distributions.

By including acoustic-elastic interactions in a topology optimization based on the covariance matrix adaptation evolution strategy, we developed acoustic cloaks of optimal design that render an object unobservable through airborne and water-borne sounds. This strategy helps exploring topologies minimize scattering sounds around made from acrylonitrile butadiene styrene copolymers frequently used as ink 3D printers. applying level set methods, our designed are expressed iso-surfaces...

The characteristics of air entrainment in hydraulic jumps below a sluice gate were systematically investigated. region is divided into the advective diffusion and breaking region. For region, it was found that concentration for fully developed inflow larger than an undeveloped under given Froude number. partially inflow, depends on boundary layer development supercritical inflow. nearly independent conditions development. Regarding effect number, both regions increases with number mechanism...

Two sets of models stepped spillways slope 1 upon 0.6 with the same crest-shape and a range step sizes (0.25–2.0 m on 1:10 scale 0.5–2.0 1:20 models) were built studied. In prototype unit flows considered (0.8–3.8 m2/s 1.8–21.7 models), residual specific energy is independent these sizes, at positions where measurements made (from 30 below crest) once fully aerated skimming flow established. The toe 50-m-high (or higher) spillway, within heights tested, <60% level similar smooth spillway...

On a spillway chute, stepped design increases the rate of energy dissipation on chute itself and reduces size downstream dissipater. Up to date, effects step roughness flow properties remain unknown despite practical relevance damaged concrete steps, rock chutes gabions weirs. New measurements were conducted in large-size laboratory facility with two conditions (smooth rough) three types roughness. Detailed air-water measured systematically for several rates. The results showed faster motion...

This paper presents an experimental study of the transition from supercritical to subcritical flow at abrupt drop. The reports a wide range conditions and relevant regime charts. Long-term results show that some configurations tend behave quasiperiodically (i.e. oscillating patterns). have direct implications on design construction spillway stilling basins where drops may be used stabilise position jump. present proposes guidelines taking into account different types, for tailwater...

Based on the covariance matrix adaptation evolution strategy (CMA-ES), advanced designs of direct-current (DC) electric cloaks composed bulk isotropic materials are presented through a topology optimization using level set method. The designed DC succeed in providing invisibility an electrical insulator flow; specifically, potential distribution is found that closely reproduces when no present. To produce this invisibility, we minimized difference between distributions for cloak and one...

To evaluate the performance of four kinds carbon dioxide (CO(2)) absorbents (Medisorb GE Healthcare, Amsorb Plus Armstrong Medical, YabashiLime Yabashi Industries, and Sodasorb LF Grace Performance Chemicals), we measured their dust production, acceptability colour indicator, CO(2) absorption capacity in vitro experimental settings concentration compound A an inspired anaesthetic circuit during vivo clinical practice. In vitro, order amount was > Medisorb = both before after shaking. The...

This paper presents a newly developed 3-axis controlled Fast Tool Servo (FTS) machining system for ultraprecision machining, which is driven in synchronization with the rotation of workpiece fixed on rotary table. The FTS unit can drive cutting tool along arbitrary cutter path space by controlling motions three piezoelectric actuators arranged axes orthogonal coordinates. directional are measured use capacitive-type proximeters and motion signals fed back to computer order guarantee required...

Many researchers studied the energy loss for skimming flows, in which main flow skims on stepped channel chute and a corner eddy is formed at each step. But general agreement experimental results has not been obtained. In this paper, flows investigated systematically under wide ranges of discharges, slopes, step heights, dam heights. The effects slope height have clarified. various changes also made clear. Further, jump formation immediately below end shown, reveal that utilization effective...

Cutting mechanism of CFRP(Carbon Fiber Reinforced Plastics) have been studied. Unidirectional prepreg were adopted to investigate effects fiber orientation (fiber angles) and tool rake angles on the chip formation. Direct SEM observation cutting experiments revealed that CFRP had three types formation: delamination, buckling type, which determined by angles. Delamination type appeared angle 0 deg. cutting. The other conditions offered continuous discontinuous provided machined surface with...