An experimental investigation of the local film cooling effectiveness and heat transfer coefficient downstream of a row of elongated holes in a simulated axial turbine blade tip is presented. Film cooling is needed to protect the turbine blade tip region from high heat transfer rates, especially when cooling by convection is insufficient to keep the temperature distribution of the blade within ...

The detection, location, and sizing of a fatigue crack emanating from a fastener hole in an aluminum plate is investigated. Two linear arrays of surface mounted piezoelectric disk transducers send and receive ultrasonic guided waves that are transmitted, reflected, and scattered by both the joint geometry and the fatigue crack. A tomography algorithm is used to detect and locate the crack. Ampl...

By optimizing critical parameters including period, thickness, hole shape and diameter, a tri-color filter based on extraordinary optical transmission through periodic hole array on metallic film is designed for OLED display, which shows high purity, narrow bandwidth and large resonant peak in simulation, and experimentally study. Also, its practicability gets confirmed by further verifications...

B holes are among the strangest predictions of Einstein’s general theory of relativity: regions of spacetime in which gravity is so strong that nothing—not even light—can escape. More precisely, a black hole is a singularity in spacetime surrounded by an event horizon, a surface that acts as a perfect one-way membrane: matter and radiation can enter the event horizon, but, once inside, can neve...

The effect of fibre orientation on buckling behaviour in a rectangular composite laminate with central circular hole under uniform in-plane loading has been studied by using finite element method. The critical buckling loads with different fibre orientation in an orthotropic composite laminate (E-glass/epoxy) were obtained. The deformation behaviour of the plate is shown for modes, i=1,2. Studi...

In this Technical Note, we describe a method of mini-open long head biceps subpectoral tenodesis. The implant used is a threadless expanding PEEK (polyether ether ketone) interference device that fixes the biceps tendon in a drill hole in the humerus under the inferior border of the pectoralis major tendon. The diameter of the drill hole varies between 6 and 8 mm depending on the width of the t...

Novel structure of a Photonic Crystal Fiber (PCF) is proposed for flattened dispersion characteristics. As compared with the conventional PCFs, the proposed PCF has no air holes in second ring area. Then the proposed PCF has a concentric missing ring PCF. Here silica glass is used as core material. It has been demonstrated that when we change the layer of PCF, dispersion is also changed. The ch...

Ti6Al4V alloy is highly used in the automotive and aerospace industry due to its good machining characteristics. Micro EDM drilling is commonly used to drill micro hole on extremely hard material with very high depth to diameter ratio. In this study, the parameters of micro-electrical discharge machining (EDM) in drilling of Ti6Al4V alloy is optimized for higher machining accuracy with less hol...

B holes are among the strangest predictions of Einstein’s general theory of relativity: regions of spacetime in which gravity is so strong that nothing—not even light—can escape. More precisely, a black hole is a singularity in spacetime surrounded by an event horizon, a surface that acts as a perfect one-way membrane: matter and radiation can enter the event horizon, but, once inside, can neve...

the endocarp of celtis australis l. with hyrcanian forests of northern iran and arid mountains of northern africa ecotypes were studied considering macro and micro morphologic characteristics, using binocular and scanning electron microscope. the aim of this research was to evaluate the endocarp diversity in different ecological conditions. the results showed that celtis australis l. is bigger,...