We demonstrate a duct muffler design that operates in the low-frequency range (<2000 Hz). The device contained pair of coupled annular Helmholtz resonators (HRs) and porous material stuffing. HRs were installed as side branches circular tube to avoid affecting ventilation. Porous materials employed form an asymmetric intrinsic loss HR enable achieve perfect sound absorption. An analytica...

The sperm-specific lactate dehydrogenase isoenzyme (LDH-X) appearing in electrophoresis between LDH-3 and LDH-4 is characteristic of human mature testis and spermatozoa. 1,21 Our previous studies have shown that detection of LDH-X by starch gel electrophoresis is quite suitable for forensic demonstration of semen from vaginal swabs. ) This communication reports the successful application of the...

Due to the large increase in Florida’s lakefront communities, the issue of noise generated by airboats has become very important. In response to this matter, Florida Fish and Wildlife Conservation Commission requested a study to determine the major factors and their contribution to the sound generated by airboats. In this study the effect of engine speed, engine type, muffler type, number of bl...

Introduction High enthalpy geothermal systems have been harnessed for electrical power generation for over a 100 years. While the classification scheme for low, medium, and high enthalpy systems varies for different authors (Axelsson and Gunnlaugsson 2000; Benderitter and Cormy 1990; Hochstein 1990; Kaya et al. 2011; Muffler and Cataldi 1978; Nicholson 1993), reservoir temperatures above 150–22...

A quasi-one-dimensional approach is presented to analyze three-pass mufflers with perforated elements using numerical decoupling. The approach is further developed to include mufflers with ducts extended into the end cavities. Theoretical predictions are compared with experiments for three different muffler configurations, one fabricated and two commercially available mufflers, and shown to agr...

Suction accumulator in rotary compressor is an important component from standpoints of compressor cost, performance, sound and ability of controlling excess liquid refrigerant. Because of its importance, it deserves its due attention to enhancement of its functions. This paper first defines functions of an accumulator, lists major design parameters and their common ranges. Then, a couple of maj...