acoustic phenomenon
Recently Published Documents


TOTAL DOCUMENTS

40
(FIVE YEARS 17)

H-INDEX

4
(FIVE YEARS 1)

Author(s):  
A. A. Garanin

The aim of the article is to update the pathophysiological mechanisms that cause the appearance and activation of pathological peristalsis of the esophagus and stomach and associated esophageal-gastrointestinal-diaphragmatic noise, described earlier, designed to expand the diagnostic capabilities of physical methods for diagnosing hiatal hernia and to facilitate the differential diagnosis of this disease with other diseases of the chest. The result of the study is to describe 5 the pathophysiological mechanisms of developing hernia hiatal and lead to the emergence of pathological motility of the esophagus and stomach in the form of the strengthening or emergence of antiperistaltic waves. The resulting acoustic phenomenon is the essence of a new physical symptom in this disease - esophageal-gastrointestinal-diaphragmatic noise. The first mechanism that determines the pathological motor activity of the smooth muscle cells of the esophageal wall is the so-called esophageal “cleansing” peristalsis, which prevents the regurgitation of the acidic contents of the stomach into the esophagus, where the environment is normally neutral. The second mechanism that causes the appearance and strengthening of pathological peristalsis of the stomach is the deformation during the passage of its part through the esophageal opening of the diaphragm into the chest cavity. The third mechanism that determines the occurrence of pathological peristalsis of the esophagus and stomach is a violation of the secretion and metabolism of nitric oxide in diaphragmatic hernias. The fourth mechanism that leads to the appearance of esophageal-diaphragmatic noise is the pathological peristalsis of the esophagus and stomach in patients with hiatal hernia, which causes the appearance of antiperistaltic waves accompanied by gastro-esophageal reflux and manifests itself in clinically pathological belching. The fifth mechanism that causes pathological peristalsis of the esophagus is the phenomenon of hydrodynamic cavitation, which occurs as a result of regurgitation of the contents of the stomach into the esophagus. Understanding the pathophysiological mechanisms that cause the appearance of pathological peristalsis and antiperistalsis of the esophagus and stomach in patients with diaphragmatic hernia allows us to understand the causes of the sound phenomenon and the associated physical symptom in this disease.


Barnboken ◽  
2021 ◽  
Author(s):  
Claus K. Madsen ◽  
Lea Allouche

Making Sense of Nonsense: Readings of Children’s Poetry as Play and Creative Thinking Abstract: Nonsense and meaning are not necessarily conflicting concepts, but can be conceived of as a hendiadys, that is, not opposites, the one or the other, but as one and the other. The idea that meaning and nonsense are related and coexist is a premise for this article, which describes different structures of meaning in the nonsense poetry of Birgitte Krogsbøll and Kamilla Wichmann’s picture book Funkelgnister: Rim, råb og remser (2015, Glittersparks: Rhymes, Roars and Rigmaroles). By linking our analysis of Funkelgnister to Johan Huizinga’s theory of play as a prerequisite for culture, we reveal how the specific structures and logics of the poems generate meaning and thereby we disclose how children’s nonsense poetry is simultaneously meaningful and nonsensical, as a creative thinking akin to culture developed through play and playfulness. We describe how meaning can be sought in three directions, suggested by Gilles Deleuze: above, below and on the surface. In the first case, we consider nonsense as a seductive acoustic phenomenon. In the second, we focus on nonsense poetry as subversive. And finally, in the third case, we show how it is an event. In all, these different aspects demonstrate how nonsense poetry functions as play and challenges our understanding of what it means to read. Following Jurij Lotman’s understanding of pictorial language as creative thinking, we show how nonsense in Funkelgnister opens up a free space by utilizing an in-between, where meaning takes on different forms as signs and sounds, and how the inherent rejection of normative rules of reading in such a venture, initiates a production of meaning as metonymic activity. We thereby highlight how nonsense generates a ground for a creative development of meaning. 


2021 ◽  
Vol 11 (20) ◽  
pp. 9768
Author(s):  
Hequn Min ◽  
Yitian Liao

The seat dip effect (SDE) is an acoustic phenomenon of low-frequency band attenuation that occurs in the music halls when the sound of the music passes at a near grazing incidence over the seats. In this paper, the numerical simulations on the basis of the finite element method are conducted to study the influence of seat attributes (seat height, seat spacing and seat absorption) on the SDE and the corresponding mechanism. The mapping of sound spatial distribution related to the SDE is employed to observe the behavior of sound between the seats. The results show that the dip frequency of the SDE can be shifted to frequencies lower than theoretical values when the seat height is smaller than the seat spacing. Additionally, the SDE attenuation can be distinctly suppressed in a sequence from the front seats to the rear seats with an absorption improvement to the seat back or cushion, and the seat back absorption is more effective than the cushion absorption. A mechanism analysis reveals that the SDE is highly associated with standing waves inside the seat gaps and with the “diffusion” effect on the grazing incident waves by energy flow vortexes around the top surfaces of the seats.


2021 ◽  
pp. 320-334
Author(s):  
Frances Crow

This chapter seeks to bring together two relationships, the first, between science and art in the West during the period of modernity and the second between the fabric of sound-space and the rendering of Echo. Following the dis-articulation of sound-space pre-empted by Sabine’s equation for reverberation (and its adoption by the acoustic profession) I draw together the various traits of echo as mythic figure, as disembodied voice and as acoustic phenomenon to consider the re-articulation of sound-space through sound-art practice. This chapter offers to artists, acousticians, and architects an alternative mapping of the history of acoustics by drawing the reader’s attention to the work of Athanasius Kircher. I suggest that he is as much the father of the acoustic arts as Mersenne, his contemporary, is the father of the acoustic sciences.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Anas Alfarsi ◽  
Céline Caillet ◽  
Garry Fawbert ◽  
Simon Lawrence ◽  
Jacob Krüse ◽  
...  

AbstractThe trade in falsified medicine has increased significantly and it is estimated that global falsified sales have reached $100 billion in 2020. The EU Falsified Medicines Directive states that falsified medicines do not only reach patients through illegal routes but also via the legal supply chain. Falsified medicines can contain harmful ingredients. They can also contain too little or too much active ingredient or no active ingredient at all. BARDS (Broadband Acoustic Resonance Dissolution Spectroscopy) harnesses an acoustic phenomenon associated with the dissolution of a sample (tablet or powder). The resulting acoustic spectrum is unique and intrinsic to the sample and can be used as an identifier or signature profile. BARDS was evaluated in this study to determine whether a product is falsified or genuine in a rapid manner and at lower cost than many existing technologies. A range of genuine and falsified medicines, including falsified antimalarial tablets from south-east Asia, were tested, and compared to their counterpart genuine products. Significant differences between genuine and falsified doses were found in their acoustic signatures as they disintegrate and dissolve. Principal component analysis was employed to differentiate between the genuine and falsified medicines. This demonstrates that the tablets and capsules included here have intrinsic acoustic signatures which could be used to screen the quality of medicines.


Metrology ◽  
2021 ◽  
Vol 1 (1) ◽  
pp. 17-38
Author(s):  
Nandeesh Hiremath ◽  
Vaibhav Kumar ◽  
Nicholas Motahari ◽  
Dhwanil Shukla

In order to progress in the area of aeroacoustics, experimental measurements are necessary. Not only are they required for engineering applications in acoustics and noise engineering, but also they are necessary for developing models of acoustic phenomenon around us. One measurement of particular importance is acoustic impedance. Acoustic Impedance is the measure of opposition of acoustical flow due to the acoustic pressure. It indicates how much sound pressure is generated by the vibration of molecules of a particular acoustic medium at a given frequency and can be a characteristic of the medium.The aim of the present paper is to give a synthetic overview of the literature on impedance measurements and to discuss the advantage and disadvantage of each measurement technique. In this work, we investigate the three main categories of impedance measurement techniques, namely reverberation chamber techniques, impedance tube techniques, and far-field techniques. Theoretical principles for each technique are provided along with a discussion on historical development and recent advancements for each technique.


2020 ◽  
Vol 8 (1) ◽  
pp. 79-106
Author(s):  
Danièle James-Raoul

AbstractThe perplexing question of the interrelations between hearing and sight looms large in the verse novel of the second half of the twelfth century, a newly promoted genre of literary fiction, no longer sung but written and intended for public reading in small circles, it seems, permanently shaped by the written word, yet brought to life by a fleeting voice. In what is commonly and sometimes abusively referred to as the Arthurian romance in verse of the second half of the twelfth century – the Arthurian part of Wace’s romance of Brut (in fact, a text between the chronicle and the romance in terms of style), the romances of Chrétien de Troyes, the romances of Tristan by Thomas and Béroul – the ‘soundtrack’ of the Arthurian literary world is poor: the human voice in particular, the sole focus of my study, is rarely mentioned, while discourse proliferates. For multiple reasons, above all because it is an acoustic phenomenon of physiological origin which is linked to breathing, the voice, as an undeniable vital force, seems to be stifled: this is what will be examined to start with. The paradoxes haunting the voice need to be addressed and assessed. In fact, it is as if vocality gave way to a rustle of words, both those of the characters and those of the narrative instances. A second step of the analysis will therefore consider how orality, patently obvious as it is, tends to mask the vocality of the text to draw attention to itself: if the voice, in its materiality, appears neglected, it is because it is henceforth subsumed under the spoken word. Yet, the voice is most saliently causing distinct stylistic traits or modes of writing which animate the jongleresque performance. The latter is having its heyday, since, at the turn of the thirteenth century, prose and the advent of silent reading would soon bring about a substantial change in the production and reception of fictional literary works: a third and last point will deal with how, until the book is to enjoy the prestige that the voice once possessed, the letter will not be that irreducibly separated from the very voice from which it originates. Far from being independent from each other, voice and letter converge in the same collaboration, that of the reading experience that allows us, to this day, to make these texts our own.


2020 ◽  
pp. 170-182
Author(s):  
Aušra Kundrotaitė

The article attempts to delineate adequate ways of thinking about the spatiality of the city in literature. It examines two semiotic approaches to the problematic of the city, namely Jurij Lotman’s semiotics of culture and Algirdas Julius Greimas’ urban semiotics, and their applicability to the analysis of its literary representation. Lotman’s concept of semiosphere is invoked to outline the complex, two-way relationship between consciousness and the city. Highlighting the communicative and autocommunication processes of culture helps to establish a link with Greimas’ interpretive and generative methodological approaches. Both Greimas and Lotman treat the city as a virtual reality concentrating on the ideological, symbolical and philosophical aspects of it. Their theories regard language primarily as an acoustic phenomenon (as speech), and consequently tend to disregard its visual (e. g. graphic) features. The article considers possible combinations of the different branches of semiotics. The special attention is focused on demonstrating the importance of the (inter)medial aspects of the literary representation. A case study of the photo-essay helps to expose similarities and differences of the semiotic and the intermedial approaches. The article demonstrates how recognizing specific (inter)medial aspects of the text allows regarding the literary city as a topological object.


2020 ◽  
Vol 10 (3) ◽  
pp. 961
Author(s):  
Jaroslaw Selech ◽  
Artūras Kilikevičius ◽  
Kristina Kilikevičienė ◽  
Sergejus Borodinas ◽  
Jonas Matijošius ◽  
...  

In this paper, a mathematical model for projectiles shooting in any direction based on sensors distributed stereoscopically is put forward. It is based on the characteristics of a shock wave around a supersonic projectile and acoustical localization. Wave equations for an acoustic monopole point source of a directed effect used for physical interpretation of pressure as an acoustic phenomenon. Simulation and measurements of novel versatile mechanical and acoustical damping system (silencer), which has both a muzzle break and silencer properties studied in this paper. The use of the proposed damping system can have great influence on the acoustic pressure field intensity from the shooter. A silencer regarded as an acoustic transducer and multi-holes waveguide with a chamber. Wave equations for an acoustic monopole point source of a directed effect used for the physical interpretation of pressure as an acoustic phenomenon. The numerical simulation results of the silencer with different configurations presented allow trends to be established. A measurement chain was used to compare the simulation results with the experimental ones. The modeling and experimental results showed an increase in silencer chamber volume results in a reduction of recorded pressure within the silencer chamber.


Sign in / Sign up

Export Citation Format

Share Document