Natural ventilation and acoustic protection are two conflicting issues. In densely populated cities, open window is nearly not possible because it can provide a path for noise to break-in from external into the buildings. A special window system, namely the plenum window, was investigated in this study for its acoustical insertion loss when the window was not parallel to the road in the urban e...

the paper presents the results of an investigation on the acoustic performance of vertical profile parallel barriers with quadratic residue diffuser tops and faces. a 2d boundary element method (bem) is used to predict the barrier insertion loss. the results of rigid and with absorptive coverage are also calculated for comparisons. using qrd on the top surface and faces of all vertical profile ...

the paper describes an investigation about the application of the new multiple-impedance discontinuities model for optimizing profile diffuser barriers. the new multiple-impedance discontinuities model is much faster than the numerical method, thus it is used in an optimization process. the a-weighted insertion loss was used for the traffic noise spectrum. the result of optimization, which is d...

Microring resonators show the possibility for designing Very Large Scale Integrated (VLSI) photonic circuits by cascading them. In order to realize the devices, the on-chip insertion loss becomes an important parameter. The direct measurement of the on-chip insertion loss of a high finesse microring resonator will be presented. Its value (0.1 ± 0.1) dB is low, in agreement with calculations.

background carbapenemes are a good choice for treatment of infections caused by multidrug resistant pseudomonads aeruginosa. the emergence of carbapenem resistance has become a major problem in treatment of this organism especially among immunocompromised patients including burn patients. objectives the aim of this study was to investigate carbapenem-resistance mechanisms among burn patients in...

The design, simulation and performance enhancement of a new structure for X-band high-power, low-loss, low-bias, triangularferrite waveguide circulator are presented. Dual circulation property is obtained by triangular shape of ferrite post. The effects of circulator’s structure parameters, such as ferrite parameters and magnetic DC bias, on isolation, insertion loss and return loss of circulat...

We investigate the loss mechanism in three-moded multimode-interference couplers that are the building blocks of a compact and low-loss waveguide crossing structure. Broadband silicon waveguide crossing arrays with <0.01  dB insertion loss per crossing are proposed using cascaded multimode-interference couplers, where lateral subwavelength nanostructures are used to reduce the insertions loss. ...

at the final stages of a coronary artery bypass graft operation on a 64-year-old man, an experienced physician attempted to insert an intra-aortic balloon pump into the femoral artery via the seldinger technique. however, while the balloon pump was being passed over the guide wire, the latter was completely lost. the guide wire should be held at the tip at all times to prevent passage into the ...

  In this paper, a microstrip lowpass filter with an ultra-wide stopband with sharp roll-off and compact size is designed and fabricated. To provide a very small dimension, T-shaped and stepped impedance have been used. The cut of frequency at -3 dB is 3.1 GHz. In the proposed structure, insertion loss is less than 0.12 and return loss is more than 15 dB. To achieve a -20dB attenuation level...