Micro-perforated absorber is a newly developed sound absorber, and it has a number of attractive features: • Unlike conventional perforated absorbers, micro-perforated absorber can be made from transparent materials like plastic glass. • Unlike commonly used fibrous absorptive materials, micro-perforated absorber is fibrous-free and thus, there is no health concern. • Micro-perforated membranes...

nowadays cmm machines are widely used in surface measurement and inspection. as inspection results from cmm machine are obtained by the means of measuring surfaces with direct contact, they are more precise than non-contact method (like optical measurement). however, cmm machines give more reliable and accurate results rather than non-contact methods but also these results come with error when ...

One way to increase the heat transfer is to use perforated twisted tapes with different hole diameters, which largely improve heat transfer with an increase in the heat transfer area at the constant volume and more mixed flow. In the previous studies, the effect of nanofluids with perforated twisted tapes is less studied. In this work, the performance of water / iron oxide nanofluid in a double...

Accurate determination of the pull-in, or the collapse voltage is critical in the design process. In this paper an analytical method is presented that provides a more accurate determination of the pull-in voltage for MEMS capacitive devices with clamped square diaphragm. The method incorporates both the linearized modle of the electrostatic force and the nonlinear deflection model of a clamped ...

In this study, we tested for the presence and efÞcacy of hygienic behavior by Cape honey bees in South Africa and European honey bees, Apis mellifera L. (Hymenoptera: Apidae), of mixed origin in the United States toward Aethina tumida Murray (Coleoptera: Nitidulidae) eggs oviposited in sealed bee brood. We looked for colony differences in removal rates of brood in cells with cappings perforated...

one way to increase the heat transfer is to use perforated twisted tapes with different hole diameters, which largely improve heat transfer with an increase in the heat transfer area at the constant volume and more mixed flow. in the previous studies, the effect of nanofluids with perforated twisted tapes is less studied. in this work, the performance of water / iron oxide nanofluid in a double...

The indispensable vital structure in any harbor is a breakwater in order to make available calm water region inshore. Pile breakwater can be employed as a small coastal protection structure where tranquility required is low. This study is concerned with CFD study on the performance of perforated hollow pile to dissipate wave energy and the novelty of this investigation is the role of perforatio...

This paper proposes a Micro-electro-mechanical (MEMS) capacitive pressure sensor that relies on the movable electrode displaced like a flat plate equal to the maximum center deflection of diaphragm. The diaphragm, movable electrode and mechanical coupling are made of polysilicon, gold and Si3N4, respectively. The fixed electrode is gold and the substrate is Pyrex glass. This proposed method inc...

In most cases, structural engineers assume a concrete floor to be a rigid diaphragm. Although this simplification is in most cases acceptable, it should be noted that such an assumption may be distrusted due to certain problems. Concrete structures with staggered shear walls are among those whose analysis should be conducted with special concern for the behavior of their floor diaphragms. Howev...

The electromechanical analysis of a piezoresistive pressure microsensor with a square-shaped diaphragm for low-pressure biomedical applications is presented. This analysis is developed through a novel model and a finite element method (FEM) model. A microsensor with a diaphragm 1000 „m length and with thickness=400 µm is studied. The electric response of this microsensor is obtained with applyi...