نتایج جستجو برای: features and sound quality
تعداد نتایج: 16967201 فیلتر نتایج به سال:
Aerogel is a unique nanoparticle that has grown dramatically in the world of chemistry over the past few decades. Aerogel features: Very low density, ultra-porous surface, sound and heat absorber, and super hydrophobic. Depending on the type of aerogels and their synthesis methods, different applications in military industries such as: Explosives, Rocket fuels, thermal insulation, sound insulat...
sound power is considered as an excellent measure for evaluating the efficiency of noise controls as well as for comparing noise sources in workrooms. this parameter can be determined by sound pressure or intensity based methods in real conditions of workrooms. this paper aims empirically to compare these in situ methods in relation to a typical industrial machine located in workroom in terms o...
abstract- noise is considered as one of the most debilitating conditions in farming operations. in this study, a number of factors affecting the noise generated by sampo 3065 combine harvesters were evaluated. factors were engine speed and gear ratio for combines with and without original cabins. a factorial experiment arranged as a completely randomized design with four replicates was used. re...
nanotechnology is a general term which is related with field of all advanced science term that generally predicates with all modern technologies which consider nanoscales. improvement in the quality of products by adding some nanoparticles and study of their behavior in the presence of these nanoparticles have been obtained in many researches. on the other hand numerous demands for sowing ...
a significant problem in multicarrier communication systems is the necessity to reduce the value of papr (peak-to-average power ratio) of transmitting signal. in this thesis we study the effect of the system parameters such as coding and modulation types on papr and ultimate ber in a mc-cdma system. in this study we consider fading channel as well as the nonlinearity of transmitter’s amplifier ...
In this chapter psycho-physical methods which are useful for both psycho-acoustics and sound-quality engineering will be discussed, namely, the methods of random access, the semantic differential, category scaling and magnitude estimation. Models of basic psycho-acoustic quantities like loudness, sharpness and roughness as well as composite metrics like psycho-acoustic annoyance will be introdu...
current studies in second language (l2) learning have revealed the positive role of corrective feedback (cf) in both oral and written forms in different language features. the present study was an attempt to investigate the effect of both direct and indirect written corrective feedback (wcf) on the use of grammatical collocations in l2 writing. the study also sought to examine whether the effec...
Introduction: The noise could affect some aspects of human health, including the cognitive performance. In addition to sound pressure level and exposure time, the psychoacoustic features of noise may cause destructive effects on humans. A few recent studies have been conducted on effect of sound quality on cognitive performance. This study aims to find the noise loudness and sharpness levels as...
the debate whether esp teachers need to have knowledge of the specialized field they are teaching has been an issue in the literature over the last two decades. the aim of conducting this study was to explore iranian learners’ and instructors’ beliefs and attitudes concerning the role of specialized knowledge in teaching esp classes. a seventeen item questionnaire was administered to 400 esp le...
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