background: noise is one of the most important harmful agents in work environment. noise pollution in oil refinery industries is related to workers' health. this study aimed to determine the overall noise pollution of an oil refinery operation and its frequency analysis to determine the control plan for a vent noise in these industries. methods: this experimental study performed in control unit...

noise exposure is one of the main problems in petroleum industry. petroleum in dustry is a strategic industry in iran with large number of workers whom are exposed to different noise sources. identification and evaluation of this noise sources and reducing excessive noises are big issues in petroleum industry from point of occupational health. this descriptive-analytic study was performed in th...

Single-shot STEAM MRI [1] is insensitive to off-resonance effects because it is based on RF refocused echoes but suffers from a inherently low signal-to-noise ratio (SNR). Recently, gradient and stimulated echo (GRASTE) imaging [2] has been shown to ameliorate the limitations of single-shot STEAM by improving the SNR efficiency. Here, an extension of 2D GRASTE is presented that is capable of ac...

PURPOSE To develop a rapid stimulated echo acquisition mode (STEAM) MRI technique for "black-blood" imaging of the human heart that overcomes the single-slice limitation and partially compromised blood suppression associated with double inversion-recovery techniques. MATERIALS AND METHODS Black-blood multislice images of the heart along anatomic orientations and triggered to end diastole were...

PURPOSE To compare signal-to-noise ratio (SNR) efficiency and diffusion tensor metrics of cardiac diffusion tensor mapping using acceleration-compensated spin-echo (SE) and stimulated echo acquisition mode (STEAM) imaging. METHODS Diffusion weighted SE and STEAM sequences were implemented on a clinical 1.5 Tesla MR system. The SNR efficiency of SE and STEAM was measured (b = 50-450 s/mm(2) ) ...

Rapid MR imaging using the stimulated echo acquisition mode (STEAM) technique yields single-shot images without any sensitivity to resonance offset effects. However, the absence of susceptibility-induced signal voids or geometric distortions is at the expense of a somewhat lower signal-to-noise ratio than EPI. As a consequence, the achievable spatial resolution is limited when using conventiona...

Rapid MR imaging using the stimulated echo acquisition mode (STEAM) technique yields single-shot images without any sensitivity to resonance offset effects. However, the absence of susceptibility-induced signal voids or geometric distortions is at the expense of a somewhat lower signal-to-noise ratio than EPI. As a consequence, the achievable spatial resolution is limited when using conventiona...

This article introduces the influence of laser’s spin projection noise on the sensitivity of Cs atom magnetometer and concludes that the theoretical value of the spin projection noise is about1.23fT·Hz under the optimization conditions of the atom steam chest, namely temperature as 105°C, volume as 0.0785cm and molecular density as 1.7×10 cm. Such research has provided us with the necessary bas...

The problem concerned is to explore the possibility of using artificial intelligence techniques, namely neural networks, and design the appropriate neural networkbased algorithm to detect signals of interest from multichannel data recordings. The problem finds application in diagnostic systems of nuclear power plant with liquidmetal fast breeder. The idea of a whole approach is to make an adapt...

MRI techniques such as quantitative imaging and parallel transmit require precise knowledge of the radio-frequency transmit field (B(1) (+)). Three published methods were optimized for robust B(1) (+) mapping at 3T in the human brain: three-dimensional (3D) actual flip angle imaging (AFI), 3D echo-planar imaging (EPI), and two-dimensional (2D) stimulated echo acquisition mode (STEAM). We perfor...