Noise reduction of spiral ducts.
نویسندگان
چکیده
The paper presents noise reduction (NR) of spiral ducts as a result of computational modeling of acoustic wave propagation. Three-dimensional models were created with the finite element method in COMSOL Multiphysics version 3.3. Nine models of spiral ducts with 1-9 spiral leads were considered. Time-harmonic analysis was used to predict NR, which was shown in spectral and interval frequency bands. Spiral duct performance can be seen as a comparison of NR before and after a change from a circular to a spiral duct.
منابع مشابه
Assessment the effect of CT localizer parameter on radiation dose and image quality of GE CT spiral images, A phantom study
Introduction: Using computed tomography (CT) is increasing significantly in Iran and worldwide. Reduction of CT's radiation dose is a critical concern. The aim of this study was evaluating the effect of localizer kVp on spiral CT images when the tube current modulation (TCM) is activated. Materials and Methods: A special wedding cake phantom with circular in...
متن کاملAn Efficient Technique for Substrate Coupling Parasitic Extraction with Application to RF/Microwave Spiral Inductors (RESEARCH NOTE)
This paper presents an efficient modeling method, based on the microstrip lines theory, for the coupling between a substrate backplane and a device contact. We derive simple closed-form formulas for rapid extraction of substrate parasitics. We use these formulas to model spiral inductors as important substrate-noise sources in mixed-signal systems. The proposed model is verified for the freque...
متن کاملتأثیر آلودگی صوتی در انتشار گلیکوکانژوگه‌های سطح سلول در گانگلیون مارپیچی نوزاد موش
Background: Some pregnant women are exposed to occupational noise, a risk factor for the development of the auditory system. The auditory system is one of the areas in embryonic development in which noise might induce aberrant development. Noise can change the gene expression pattern of an embryo and thereby modify the physiology of the auditory system. Therefore, noise can change the molecular...
متن کاملA Phase Noise Reduction Technique in LC Cross-coupled Oscillators with Adjusting Transistors Operating Regions
In this paper, an intuitive analysis of a phase noise reduction technique is done, and then a modified structure is proposed to achieve higher phase noise reduction than the original one. This method reduces the impact of noise sources on the phase noise by decreasing closed-loop gain in zero-crossings points and moving this high closed-loop gain to the non-zero-crossings points. This reduction...
متن کاملSpiral readout gradients for the reduction of motion artifacts in chemical shift imaging.
A motion artifact reduction method for proton chemical shift imaging (CSI) is presented. The method uses spiral-based readout gradients for data acquisition. A characteristic of spiral-based readout gradients is that data are repeatedly sampled at the kxy origin. These data points are used to estimate and correct for motion-induced phase variations. Both phantom and in vivo spectra reconstructe...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- International journal of occupational safety and ergonomics : JOSE
دوره 13 4 شماره
صفحات -
تاریخ انتشار 2007