Effect Of Excess Noise Research Articles

Noise evaluation in oil and gas fields and associated risk assessment

This work investigates the noise levels in oil and gas fields and their impact on the health of operators, visitors, and trainees in these workplaces, as well as possible methods of maintaining that noise within acceptable levels. A risk assessment was performed to identify the noise hazards associated with particular activities or tasks in oil and gas fields. A case study focusing on sulfur recovery units (SRUs) at a gas processing complex consisting of three production plants was carried out. Many master points in these plants where workers present were selected at random. In order to accurately measure the noise level at each point, it was measured at different times during the period 2014–2017 and compared with the maximum safe noise level defined by OSHA (85 dB). Results show that most of the noise levels encountered in the field are above the maximum level. An Ishikawa diagram was created to analyze the causes and effects of excessive noise in the field. Causes included rotating machines, maintenance activities, steam leakages, fluid flows, and gas flares. Finally, the results of the risk assessment indicated that oil and gas fields can present high noise risk scores, implying that workers in those fields could be harmed by the noise.

Enhancing the sensitivity of an atom interferometer to the Heisenberg limit using increased quantum noise

In a conventional atomic interferometer employing N atoms, the phase sensitivity is at the standard quantum limit: 1 / N . Under usual spin squeezing, the sensitivity is increased by lowering the quantum noise. It is also possible to increase the sensitivity by leaving the quantum noise unchanged while producing phase amplification. Here we show how to increase the sensitivity, to the Heisenberg limit of 1 / N , while increasing the quantum noise by N and amplifying the phase by a factor of N . Because of the enhancement of the quantum noise and the large phase magnification, the effect of excess noise is highly suppressed. The protocol uses a Schrödinger cat state representing a maximally entangled superposition of two collective states of N atoms. The phase magnification occurs when we use either atomic state detection or collective state detection; however, the robustness against excess noise occurs only when atomic state detection is employed. We show that for one version of the protocol, the signal amplitude is N when N is even, and is vanishingly small when N is odd, for both types of detection. We also show how the protocol can be modified to reverse the nature of the signal for odd versus even values of N . Thus, for a situation where the probability of N being even or odd is equal, the net sensitivity is within a factor of 2 of the Heisenberg limit. Finally, we discuss potential experimental constraints for implementing this scheme via one-axis-twist squeezing employing the cavity feedback scheme, and show that the effects of cavity decay and spontaneous emission are highly suppressed because of the increased quantum noise and the large phase magnification inherent to the protocol. As a result, we find that the maximum improvement in sensitivity can be close to the ideal limit for as many as 10 million atoms.

Adaptive multidirectional frequency domain filter for noise removal in wrapped phase patterns.

In order to avoid the detrimental effects of excessive noise in the phase fringe patterns of a laser digital interferometer over the accuracy of phase unwrapping and the successful detection of mechanical fatigue defects, an effective method of adaptive multidirectional frequency domain filtering is introduced based on the characteristics of the energy spectrum of localized wrapped phase patterns. Not only can this method automatically set the cutoff frequency, but it can also effectively filter out noise while preserving the image edge information. Compared with the sine and cosine transform filtering and the multidirectional frequency domain filtering, the experimental results demonstrate that the image filtered by our method has the fewest number of residues and is the closest to the noise-free image, compared to the two aforementioned methods, demonstrating the effectiveness of this adaptive multidirectional frequency domain filter.

Effects of excessive noise and reverberation on listening and learning in a simulated classroom.

Elementary students often learn in dynamic discussions during typical classroom lessons. Many classrooms, though, have poor signal‐to‐noise ratios and long reverberation times. The presence of excessive noise and reverberation may increase a student’s listening effort and result in reduced performance during classroom learning. A simulated classroom environment was created which allowed for varying degrees of room reverberation and background noise. In this experiment, groups of elementary‐aged students were seated in the center of the simulated classroom environment and were presented a story read by either five talkers positioned around the student or a single talker in front of the student (reproduced by LCD monitors and loudspeakers). A post‐test was used to assess listener comprehension. Comprehension scores are compared to a group of adult subjects as well as a sentence‐recognition task in the same condition. Significant differences were seen in comprehension scores as a function of age and condition, both increasing background noise and reverberation degraded performance in comprehension tasks compared to little or no differences in measures of sentence‐recognition. Finally, comprehension scores are correlated to measures of the speech transmission index in each of the simulated classroom environments.

Electron transport and current fluctuations in short coherent conductors

Employing a real time effective action formalism we analyze electron transport and current fluctuations in comparatively short coherent conductors in the presence of electron-electron interactions. We demonstrate that, while Coulomb interaction tends to suppress electron transport, it may {\it strongly enhance} shot noise in scatterers with highly transparent conducting channels. This effect of excess noise is governed by the Coulomb gap observed in the current-voltage characteristics of such scatterers. We also analyze the frequency dispersion of higher current cumulants and emphasize a direct relation between electron-electron interaction effects and current fluctuations in disordered mesoscopic conductors.

Noise control: Experimental research in Kuwait

Abstract Environmental noise has been found in many experimental research studies in Kuwait, to be a prominent factor which influences the level of satisfaction with a particular residential environment. This can be seen also as a consequence of the higher level of awareness today about the adverse effects of excess noise on human beings and their environment. The effects of noise, criteria, community noise in Kuwait, aircraft noise impact on the airport environs, and fuzzy set concepts for evaluating noise interference models, are the topics of this paper. Review of the experimental research and results of the analysis show that the community noise equivalent level [CNEL] was significantly correlated with both the prevalence of the complaints and their severity. The airport management should set up a noise abatement committee to develop procedures that are mutually acceptable and will have the least objectionable noise impact on urbanized areas. Recommendations for further studies are also presented.

Some notes on the effects of excessive noise on the hearing of a group of workers.

The data for the present investigation were col lected between August, 1951, and August, 1956, in the Butterley Company's works at Codnor Park. In some of the shops of these works the noise is so intense that outsiders experience it as unpleasant and in some spots even as unbearable. During the period mentioned no protective devices were in use, largely because the workers found many of the existing protectors both uncomfortable and other wise inconvenient. The availability of audiometric records of workers who had been exposed to noise for periods from one year to seven years made possible a first attempt to relate deterioration in hearing to prolonged exposure to intense intermittent noise. That such deterioration (based on permanent and irreversible changes in the auditory organs) occurs is well known. But the relationship between length of exposure and loss is somewhat complicated by the fact that a certain amount of loss is brought about by the natural process of ageing (presbycusis).