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1.
Ultrasonics ; 104: 106108, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32145443

RESUMO

High intensity focused ultrasound (HIFU) has great potential to thermally ablate diseased tissues with minimal invasion. Yet, HIFU practice has limited cancer treatment potential since the absorption, diffusion, and reflection of ultrasound prevent HIFU from penetrating the body to deep and concealed diseased tissue. To explore a vision of deployable HIFU transducers, this research introduces an origami-inspired concept wherein a deployable tessellated acoustic array is employed to reduce the distance between the HIFU transducer and diseased tissues. A flat-foldable HIFU transducer array is considered, such that the compact shape is used to pass through the human body and then deployed into the operational form for treatment. Here a theoretical framework is developed to study the focusing and thermal heating capabilities of the tessellated array in a multilayer environment. It is observed that the wavefield and thermal elevation realized by the foldable array are functionally similar to those of an ideal arc-shaped transducer. Folding patterns that permit adequate curvature and high quality factor, and that balance slenderness and conformability are found to be beneficial for an ultrasound focusing practice. The efficacy of the analytical predictions are verified through direct numerical simulations. All together, the results encourage attention to foldable array concepts as potential means to advance in-vivo HIFU-based procedures.


Assuntos
Ablação por Ultrassom Focalizado de Alta Intensidade/instrumentação , Transdutores , Acústica , Desenho de Equipamento , Análise de Elementos Finitos , Temperatura Alta , Propriedades de Superfície
2.
Ultrasonics ; 103: 106086, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32070827

RESUMO

Ultrasonic bioreactors have been used for in vitro experimentation to study cellular responses to low-intensity pulsed ultrasound. The presence of an air interface in these bioreactors contributes to variability in the acoustic pressure field, reducing experimental reproducibility. A multiphysics finite element model was developed to simulate the acoustic field in an in-dish ultrasonic bioreactor, where the transducer is immersed in culture medium above the dish surface, and the effects of replacing air below the dish in the bioreactor with a water layer bounded by an acoustic absorbent layer were evaluated. Frequency domain simulations showed that the spatially-averaged pressure at the dish surface alternated between a minimum and maximum level as the distance between the dish and transducer increased. The ratio of the maximum to minimum level was 6.5-fold when the air interface was present, and this ratio dropped to 1.8-fold with replacement of the air interface. However, radial pressure variability was present with or without the air interface in the bioreactor model. Time-dependent simulations showed that the increase in acoustic pressure to a maximum level after US signal activation and the pressure drop after signal cessation were faster when the water-coupled non-reflective layer was used to replace the air layer below the dish, generating a pressure pattern that more closely followed the applied pulsed ultrasound signal due to reduced wave reflection and interference. Overall, this work showed that having water rather than air in contact with the lower dish surface when paired with an acoustic absorbent layer resulted in a less variable pressure field, providing an improved bioreactor design for in vitro experiments.


Assuntos
Acústica , Reatores Biológicos , Análise de Elementos Finitos , Fenômenos Biofísicos , Meios de Cultura , Desenho de Equipamento , Pressão , Software , Propriedades de Superfície , Transdutores , Ultrassom , Água
3.
Sud Med Ekspert ; 63(1): 24-30, 2020.
Artigo em Russo | MEDLINE | ID: mdl-32040084

RESUMO

The significance of phonetically representative texts in the study of the individuality of voice and speech of speakers in the analysis of the acoustic parameters of the timbre of the voice from experimental speech phonograms in order to search for signs that individualize the speaker's personality is considered. The results of the study of the most common texts from the position of phonetic representativeness and balance, the naturalness of the functioning of the speech apparatus and the temporary load on it in the process of voicing texts are presented. To implement the planned scientific research on the analysis of the acoustic parameters of the voice timbre, a corpus of phonetically representative texts has been compiled, consisting of well-known lexical materials and a special text including phonetic units missing in the original material.


Assuntos
Fonética , Fala , Voz , Acústica , Acústica da Fala
4.
Pharm Res ; 37(3): 38, 2020 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-31965333

RESUMO

PURPOSE: Asthma is a prevalent lung disorder that cause heavy burdens globally. Inhalation medicaments can relieve symptoms, improve lung function and, thus, the quality of life. However, it is well-documented that patients often do not get the prescribed dose out of an inhaler and the deposition of drug is suboptimal, due to incorrect handling of the device and wrong inhalation technique. This study aims to design and fabricate an acoustic dry powder inhaler (ADPI) for monitoring inhalation flow and related drug administration in order to evaluate whether the patient receives the complete dose out of the inhaler. METHODS: The devices were fabricated using 3D printing and the impact of the acoustic element geometry and printing resolution on the acoustic signal was investigated. Commercial Foradil (formoterol fumarate) capsules were used to validate the availability of the ADPI for medication dose tracking. The acoustic signal was analysed with Partial-Least-Squares (PLS) regression. RESULTS: Indicate that specific acoustic signals could be generated at different air flow rates using a passive acoustic element with specific design features. This acoustic signal could be correlated with the PLS model to the air flow rate. A more distinct sound spectra could be acquired at higher printing resolution. The sound spectra from the ADPI with no capsule, a full capsule and an empty capsule are different which could be used for medication tracking. CONCLUSIONS: This study shows that it is possible to evaluate the medication quality of inhaled medicaments by monitoring the acoustic signal generated during the inhalation process.


Assuntos
Asma/tratamento farmacológico , Broncodilatadores/química , Inaladores de Pó Seco/instrumentação , Fumarato de Formoterol/química , Impressão Tridimensional , Acústica , Administração por Inalação , Asma/fisiopatologia , Broncodilatadores/administração & dosagem , Sistemas de Liberação de Medicamentos/instrumentação , Desenho de Equipamento/instrumentação , Fumarato de Formoterol/administração & dosagem , Humanos , Análise dos Mínimos Quadrados , Pulmão/metabolismo , Monitorização Fisiológica/instrumentação , Pós/química , Pós/farmacologia , Análise de Regressão , Som
5.
J Stroke Cerebrovasc Dis ; 29(2): 104508, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31759914

RESUMO

BACKGROUND: It is recommended that enteral feeding should be offered to patients with dysphagia estimated to be unable to take adequate diet orally within 7 days of admission after acute stroke, but there is no clear criterion for initiation of enteral feeding. Recent studies have reported that the frequency of spontaneous swallowing is useful in screening for dysphagia in acute stroke. The present study was aimed to investigate whether measurement of frequency of spontaneous swallowing for 2 minutes could predict independence on enteral feeding 1 week after admission in patients with acute stroke. METHODS: Patients with acute stroke were subjected. Within 72 hours of stroke onset, the number of swallows for 2 minutes was measured by auscultation. Subsequently, 1-hour frequency of spontaneous swallowing was measured using a laryngeal microphone. Functional Oral Intake Scale (FOIS) was evaluated 1 week after admission. RESULTS: Twenty-six out of 40 patients were independent on enteral feeding 1 week after admission based on FOIS. The presence of spontaneous swallowing for 2 minutes had .89 sensitivity, .54 specificity to predict independence on enteral feeding 1 week after admission, whereas the 1-hour frequency of spontaneous swallowing had 1.00 sensitivity, .46 specificity. Logistic regression analysis demonstrated that the presence of spontaneous swallowing for 2 minutes was independent predictor for independence on enteral feeding 1 week after admission, independently of age, sex, and NIHSS. CONCLUSIONS: The 2-minute spontaneous swallowing screening predicts independence on enteral feeding 1 week after admission in patients with acute stroke.


Assuntos
Acústica , Transtornos de Deglutição/diagnóstico , Deglutição , Nutrição Enteral , Acidente Vascular Cerebral/complicações , Acústica/instrumentação , Idoso , Tomada de Decisão Clínica , Transtornos de Deglutição/etiologia , Transtornos de Deglutição/fisiopatologia , Transtornos de Deglutição/terapia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Seleção de Pacientes , Valor Preditivo dos Testes , Prognóstico , Fatores de Risco , Acidente Vascular Cerebral/diagnóstico , Acidente Vascular Cerebral/fisiopatologia , Acidente Vascular Cerebral/terapia , Fatores de Tempo
6.
J Prosthet Dent ; 123(2): 355-363, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31307797

RESUMO

STATEMENT OF PROBLEM: Prosthetic interventions at various stages help patients recover from esthetic and functional disabilities. However, little is known regarding their impact on patient quality of life (QOL) during various phases of treatment. PURPOSE: The purpose of this clinical study was to evaluate changes in the QOL and acoustic speech parameters of patients rehabilitated by using a prosthesis at various stages after undergoing maxillectomy. MATERIAL AND METHODS: A total of 30 consecutive patients who underwent maxillectomy resection and successfully completed all phases of rehabilitation with obturator prostheses were included. The study was conducted in 4 phases. In the preoperative phase, patients were evaluated for QOL and speech, and dental impressions were made. In the immediate postoperative phase, patients were rehabilitated with a delayed surgical obturator on the fifth postoperative day and were evaluated for QOL and speech on the 12th postoperative day. In the interim obturator phase, patients were rehabilitated with an interim maxillary obturator between the 12th and 15th postoperative days and were evaluated for QOL and speech after using the prosthesis for a minimum of 1 week. In the definitive phase, nonradiated patients were rehabilitated with a definitive prosthesis in the sixth week, and radiated patients were rehabilitated with a definitive prosthesis in the sixth month. The QOL and speech parameters of the patients were evaluated after 1 week. QOL evaluation in each phase was performed by using the EORTC QLQ-C30 and EORTC QLQ-H&N35 questionnaires. Speech parameters, namely intensity, fundamental frequency, habitual frequency, jitter, shimmer, maximum phonation time, and the S/Z ratio, were measured by using acoustic speech software. The change in QOL over various phases of rehabilitation with an obturator was analyzed by using repeated measures analysis of variance, whereas changes in acoustic speech parameters were analyzed by using the Friedman test (α=.05). RESULTS: A statistically significant difference (P<.05) was observed in the physical function, role function, fatigue, nausea, vomiting, dyspnea, sleep, and appetite loss domains of the EORTC QLQ-C30 and in the speech, social eating, social contact, mouth opening, dry mouth, sticky saliva, use of painkillers, and feeding tube domains of the EORTC QLQ-H&N35. The analysis of speech parameters also revealed significant improvement in intensity, jitter, shimmer, maximum phonation time, and the S/Z ratio, suggesting improvement in speech with the use of different types of obturators. CONCLUSIONS: The overall QOL and speech of the patients showed increasing improvement with the use of surgical obturators, immediate obturators, and definitive obturators in that order. The disease symptoms and oral functions deteriorated in the immediate postoperative phase but improved steadily and approached the preoperative level with definitive obturator prostheses.


Assuntos
Neoplasias Maxilares , Qualidade de Vida , Acústica , Estética Dentária , Humanos , Obturadores Palatinos , Fala
8.
Carbohydr Polym ; 227: 115282, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31590860

RESUMO

Acoustic emissions are stress or elastic waves produced by a material under external load. Since acoustic emissions are generated from within and transmitted through the substance, the acoustic signature provides insights into the physical and mechanical properties of the material. In this report, we used a constant velocity probe with force and acoustic emission monitoring to investigate the properties of glass phase and gel phase pectin films. In the gel phase films, a constant velocity uniaxial load produced periodic premonitory acoustic emissions with coincident force variations (saw-tooth pattern). SEM images of the gel phase microarchitecture indicated the presence of slip planes. In contrast, the glass phase films demonstrated early acoustic emissions, but effectively no force or acoustic evidence of periodic or premonitory emissions. Microstructural imaging of the glass phase films indicated the presence of early microcracks as well as dense polymerization of the pectin (without evidence of slip planes). We conclude that the water content in the pectin films contributes to not only the physical properties of the films, but also the stick-slip motion observed with constant uniaxial load. Further, acoustic emissions provide a sensitive and practical measure of this mechanical behavior.


Assuntos
Acústica , Pectinas/química , Microscopia Eletrônica de Varredura , Pectinas/ultraestrutura , Transição de Fase , Microtomografia por Raio-X
9.
Ultrason Sonochem ; 60: 104797, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31546086

RESUMO

Ultrasonicaion is non-chemical process where acoustic waves have been targeted to aqueous medium dispersed precursor materials. In situ synthesis of silver nanoparticles anchored in hydrogel matrix has been opted via ~20 kHz frequency assisted (bath sonication) synthesis having the ultrasonication power intensity (UPI) of ~106 J/m2. Power intensity is inversely proportional to the surface area of the clay tactoids. The hydrogel have been prepared by in situ 20 kHz assisted sonochemical destratification of laponite clay tactoids which could be terminologically stated as 'top-down method'. Silver nanoparticles (AgNPs) have been deposited in the surfaces of the porous matrix of hydrogel via 'soak and irradiate' method. Soaking of silver ions into the gel matrix is welcomed due to their efficient stabilization and fast transformation towards AgNPs. AgNPs played the key role in catalytic reduction and bactericidal activity. Moreover, the prepared hydrogel has enough robust to withstand cyclic stress, uniaxial stress and oscillatory stress which have been extensively justified by the physico-mechanical characterizations. The gel supported catalyst showed first order reaction kinetics and less time consuming period during reduction of 4-nitrophenol as a model pollutant.


Assuntos
Acústica , Antibacterianos/química , Argila , Elastômeros/química , Hidrogéis/química , Sonicação/métodos , Catálise , Cinética , Nanopartículas Metálicas/química , Nitrofenóis/química , Oxirredução , Prata/química , Nitrato de Prata/química
10.
Codas ; 31(6): e20180117, 2019.
Artigo em Português, Inglês | MEDLINE | ID: mdl-31800878

RESUMO

PURPOSE: To investigate the immediate effect of phonation into silicone tube on self-assessment and vocal quality of gospel singers. METHODS: The sample was composed of 40 gospel singers without vocal complaint, males and females, from 18 to 40 years. The singers performed semi-occluded vocal tract exercise in LaxVox® silicone tube. The end of the tube was submerged in water (2cm depth), for three minutes. Before and after exercise, voice recording was performed for perceptive-auditory evaluation, and only after exercise, the voice and comfort phonation self-assessments (CSA) were performed. The descriptive and inferential statistical analysis were performed. RESULTS: All participants reported improvement in voice. In addition, a significant higher proportion of them indicated phonation comfort improvement after exercise. According to the perceptive-auditory evaluation, there was no difference in the comparison of the proportions of pre- and post-exercise perceptive-auditory evaluation categories in gospel singers. CONCLUSION: The phonation exercise into a silicone tube caused an immediate positive effect on gospel singers' voice and comfort phonation self-assessments. There was no significant difference in the perceptive-auditory evaluation before and after phonation into silicone tube in gospel singers.


Assuntos
Fonação , Treinamento da Voz , Voz/fisiologia , Acústica , Adolescente , Adulto , Feminino , Humanos , Masculino , Estudos Prospectivos , Autoavaliação , Silicones , Canto , Qualidade da Voz , Adulto Jovem
11.
PLoS Comput Biol ; 15(12): e1007550, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31856162

RESUMO

Most objects and vegetation making up the habitats of echolocating bats return a multitude of overlapping echoes. Recent evidence suggests that the limited temporal and spatial resolution of bio-sonar prevents bats from separately perceiving the objects giving rise to these overlapping echoes. Therefore, bats often operate under conditions where their ability to localize obstacles is severely limited. Nevertheless, bats excel at avoiding complex obstacles. In this paper, we present a robotic model of bat obstacle avoidance using interaural level differences and distance to the nearest obstacle as the minimal set of cues. In contrast to previous robotic models of bats, the current robot does not attempt to localize obstacles. We evaluate two obstacle avoidance strategies. First, the Fixed Head Strategy keeps the acoustic gaze direction aligned with the direction of flight. Second, the Delayed Linear Adaptive Law (DLAL) Strategy uses acoustic gaze scanning, as observed in hunting bats. Acoustic gaze scanning has been suggested to aid the bat in hunting for prey. Here, we evaluate its adaptive value for obstacle avoidance when obstacles can not be localized. The robot's obstacle avoidance performance is assessed in two environments mimicking (highly cluttered) experimental setups commonly used in behavioral experiments: a rectangular arena containing multiple complex cylindrical reflecting surfaces and a corridor lined with complex reflecting surfaces. The results indicate that distance to the nearest object and interaural level differences allows steering the robot clear of obstacles in environments that return non-localizable echoes. Furthermore, we found that using acoustic gaze scanning reduced performance, suggesting that gaze scanning might not be beneficial under conditions where the animal has limited access to angular information, which is in line with behavioral evidence.


Assuntos
Quirópteros/fisiologia , Ecolocação/fisiologia , Modelos Biológicos , Robótica/instrumentação , Acústica , Algoritmos , Animais , Aprendizagem da Esquiva/fisiologia , Comportamento Animal/fisiologia , Quirópteros/psicologia , Biologia Computacional , Simulação por Computador , Sinais (Psicologia) , Voo Animal/fisiologia , Robótica/estatística & dados numéricos
12.
Zootaxa ; 4613(3): zootaxa.4613.3.1, 2019 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-31716397

RESUMO

In this paper, we provide some available information about the occurrence and some taxonomic aspects of 19 species from the Superfamily Oplophoroidea in the southwestern Atlantic (Brazilian waters), with the update to 22 species of Oplophoroidea occurring in Brazilian waters. Samples were collected during two sets of surveys. The first was performed in 2009 and 2011 in the Potiguar Basin in northeast of Brazil (03-05°S; 38-35°W; between the States of Ceará and Rio Grande do Norte) under the framework of the project "Avaliação da biota bentônica e planctônica da Bacia Potiguar e Ceará (Bpot)", with samples collected from bottom trawls in the continental slope at depth ranging from 150-2068 m. Second, under the in the framework of the ABRACOS (Acoustic along the Brazilian coast), performed in 2015 and 2017 on seamounts and offshore areas in Northeast Brazil (Ceará Chain, Rio Grande do Norte and Rocas Atoll, Fernando de Noronha Archipelago and Pernambuco State), with samples with pelagic micronekton and mesopelagic nets, in depths ranging from 50-1260 m. We highlight the occurrence of 14 species of the family Acanthephyridae and 5 species of the family Oplophoridae, including the first occurrences of five species to Brazilian deep waters: Acanthephyra kingsleyi Spence Bate, 1888, Ephyrina ombango Crosnier Forest, 1973, Meningodora compsa (Chace, 1940), M. longisulca Kikuchi, 1985 and Systellapsis curvispina Crosnier, 1987. These records increase the knowledge on deep-sea shrimps occurring in Southwestern Atlantic.


Assuntos
Acústica , Animais , Oceano Atlântico , Brasil , Inquéritos e Questionários
13.
Zootaxa ; 4563(1): zootaxa.4563.1.3, 2019 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-31716553

RESUMO

This study describes a new member of the genus Leptobrachella, Leptobrachella shangsiensis sp. nov., based on morphological, acoustic and molecular analyses from southern Guangxi, China. L. shangsiensis sp. nov. differs from its congeners by a combination of the following characters: (1) SVL 24.9-29.4 mm in 11 males and 30.8-35.9 mm in 5 females, (2) black supratympanic fold with dark reddish rim, (3) ventrolateral glands distinct, forming a broken line, (4) ventral surface yellowish creamy-white with marble texture, (5) iris copper in the upper and silver in the lower fifth and (6) toe webbing basal and narrow lateral fringes. The male advertisement call of L. shangsiensis sp. nov. consists of one note per call, lacking an introductory note, with a mean dominant frequency of 5.5-6.5 kHz at the ambient temperature of 21.5ºC. Uncorrected sequence divergences between L. shangsiensis sp. nov. and all homologous DNA sequences available for the 16S rRNA gene were found to be > 5.9%. L. shangsiensis sp. nov. occurs in an evergreen forest in Shiwandashan National Nature Reserve located at an elevation of 450-550 m.


Assuntos
Anuros , Florestas , Acústica , Animais , China , Feminino , Masculino , Filogenia , RNA Ribossômico 16S
14.
Zootaxa ; 4656(1): zootaxa.4656.1.14, 2019 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-31716849

RESUMO

In anurans, acoustic signal traits are useful for understanding patterns of evolutionary processes, behavioral interactions, and providing diagnostic characters for inferring phylogenetic relationships and delimiting species (Cocroft Ryan 1995). The advertisement call, which is the vocalization emitted to attract females or segregate conspecific males, is the most conspicuous and studied acoustic signal (Toledo et. al. 2014). However, it remains unknown for many anuran species (Köhler et al. 2017; Guerra et al. 2018).


Assuntos
Anuros , Vocalização Animal , Acústica , Animais , Evolução Biológica , Feminino , Masculino , Filogenia
15.
Zootaxa ; 4609(3): zootaxa.4609.3.8, 2019 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-31717098

RESUMO

Mountain chains and rivers are often found to represent barriers promoting vicariant differentiation in terrestrial vertebrates. Previous studies have supported the idea that the Cordillera de Mérida (CM), the easternmost branch of the Northern Andes, represents a geographic barrier for vertebrates, including frogs. Previous studies have also suggested that the Orinoco River (OR), the biggest river in Venezuela, also represents a geographic barrier for terrestrial vertebrates. Boana pugnax and B. xerophylla are two Neotropical hylids, members of the B. faber species group, that are distributed on either side of the CM, and whose ranges extend up to 605 and 2450 m in elevation, respectively. In addition, B. xerophylla occurs on either side of the OR. Herein, we assess the genetic, acoustic, and morphological differentiation within B. pugnax and within B. xerophylla across the CM and within B. xerophylla across the OR, and test if genetic differentiation is correlated with geographic distance. We also evaluated the acoustic differentiation between the recently recognized B. xerophylla and its sister species, B. crepitans, and found marked differences between advertisement calls, corroborating their status as distinct species. Genetic and morphometric analyses of populations from opposite sides of the CM revealed differentiation in B. pugnax but not in B. xerophylla. Within the latter species, we found molecular, acoustic, and morphometric differentiation among samples of B. xerophylla from western Venezuela versus the Guiana Shield. Genetic variation within B. pugnax and within B. xerophylla was not explained by geographic distance. Thus, our data show conspecific population structure across the CM in B. pugnax, plus the possible existence of two species within what today is considered B. xerophylla, yet the CM apparently is not involved in this divergence. These results suggest that even for closely related species with shared ecology and distribution, genetic and phenotypic differentiation respond differently to common ecological or historical factors.


Assuntos
Anuros , Deriva Genética , Acústica , Animais , DNA Mitocondrial , Variação Genética , Filogenia , Filogeografia , Rios , Venezuela
16.
Zootaxa ; 4603(2): zootaxa.4603.2.4, 2019 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-31717228

RESUMO

Seventeen endemic and three sub-endemic species belonging to three subfamilies of Tettigoniidae (Orthoptera: Bradyporinae, Phaneropterinae and Tettigoniinae) were sampled during field trips throughout different regions of Anatolia between 2015 and 2018 (except one taxon). Acoustic parameters of these 20 bush-cricket species affiliated to 12 genera (Apholidoptera, Bradyporus, Decticus, Eupholidoptera, Parapholidoptera, Pezodrymadusa, Pholidoptera, Polysarcus, Psorodonotus, Squamiana, Uvarovistia and Yalvaciana) have been described for the first time in this study. Bioacoustical analysis shows that male calling songs are species-specific for the genera Bradyporus, Parapholidoptera, Pholidoptera, Apholidoptera, Uvarovistia and Psorodonotus. However, there are no distinct differences among species of the genus Pezodrymadusa. Moreover, our additional data on genus Eupholidoptera indicate that there are some different song patterns within the genus. The song description of Uvarovistia zebra presented here is the second bioacoustics data on this genus. The acoustical analyses data support the morpho-species hypothesis of Psorodonotus suphani Taylan Sirin, 2014, which is known from Süphan Mountain (Bitlis province, Eastern part of Turkey) and reject Kaya Çiplak (2017), which recommended it as synonym to P. caucasicus (Fischer von Waldheim, 1846) (commonly known as a Black Sea Region species).


Assuntos
Gryllidae , Ortópteros , Acústica , Animais , Mar Negro , Masculino , Especificidade da Espécie , Turquia
17.
Science ; 366(6469): 1076-1077, 2019 11 29.
Artigo em Inglês | MEDLINE | ID: mdl-31780545
18.
Environ Monit Assess ; 191(12): 765, 2019 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-31754865

RESUMO

To be able to geographically map, model and evaluate noisy sound emissions from industrial motors, emphases have been laid on various phenomena linked to the propagation of sound waves and their effects on the environment. The failure to respect factory-servicing norms coupled with the depreciation of parts of an industrial motor lead to additional sound production, which due to an accumulation in acoustic power and pressure levels contributes to environmental noise pollution. In this work, a study has been carried out on environmental noise pollution from a thermal power plant in Cameroon, using empirical, diagrammatic, analytical and noise map elaboration methods, with the aim of proposing an optimal protection of the surroundings of the thermal plant from the noise pollution. The results obtained show a similarity in propagation of acoustic pressure and power levels for the different types of frequencies considered. Besides these, the study has revealed that the inhabitants are exposed to sound levels higher than the upper limit of 50 dB and above the alert threshold level of 80 dB. At the geo-localized motors of the plant, the primary sources of acoustic power levels were found to fall within the range from 60 to 98 dB, which is very close to the acoustic pressure levels of between 60 and 95 dB. Due to dispersion of sound, the acoustic power levels are also felt at different points around the plant, considered here as secondary sources. From a general point of view, the observed distribution of the iso-sound contours from the collected data and their general NE-SW orientations show the development of new sources due to cumulative effects and superposition of sound waves at regular intervals. At the same time, the acoustic power and pressure levels have been found to be higher than 80 dB, which is the threshold value for human hearing. This therefore is considered detrimental to human health and wellbeing, provoking the need for a more profound investigation on the existing correlation between levels of sound due to stationary sources and frequency in a high sound medium and elaborating a strategic noise map for the town of Mbalmayo and its environs.


Assuntos
Mapeamento Geográfico , Instalações Industriais e de Manufatura , Modelos Teóricos , Ruído , Acústica , Camarões , Monitoramento Ambiental , Instalações Industriais e de Manufatura/estatística & dados numéricos , Centrais Elétricas/estatística & dados numéricos
19.
Biol Lett ; 15(10): 20190513, 2019 10 31.
Artigo em Inglês | MEDLINE | ID: mdl-31662064

RESUMO

Although the effects of anthropogenic noise on animal communication have been studied widely, most research on the effect of noise in communication has focused on signals in a single modality. Consequently, how multi-modal communication is affected by anthropogenic noise is relatively poorly understood. Here, we ask whether song sparrows (Melospiza melodia) show evidence of plasticity in response to noise in two aggressive signals in acoustic and visual modalities. We test two hypotheses: (i) that song sparrows will shift signalling effort to the visual modality (the multi-modal shift hypothesis) and (ii) that they will increase redundancy of their multi-modal signalling (the back-up signal hypothesis). We presented male song sparrows with song playback and a taxidermic mount with or without a low-frequency acoustic noise from a nearby speaker. We found that males did not switch their signalling effort to visual modality (i.e. wing waves) in response to the noise. However, the correlation between warbled soft songs and wing waves increased in the noise treatment, i.e. signals became more redundant. These results suggest that when faced with anthropogenic noise, song sparrows can increase the redundancy of their multi-modal signals, which may aid in the robustness of the communication system.


Assuntos
Pardais , Acústica , Comunicação Animal , Animais , Masculino , Ruído , Vocalização Animal
20.
Molecules ; 24(19)2019 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-31569440

RESUMO

Acoustic emission (AE) source localization is one of the important purposes of nondestructive testing. The localization accuracy reflects the degree of coincidence between the identified location and the actual damage location. However, the anisotropy of carbon fiber three-dimensional braided composites will have a great impact on the accuracy of AE source location. In order to solve this problem, the time-frequency domain characteristics of AE signals in a carbon fiber braided composite tensile test were analyzed by Hilbert-Huang transform (HHT), and the corresponding relationship between damage modes and AE signals was established. Then, according to the time-frequency characteristics of HHT of tensile acoustic emission signals, the two-step method was used to locate the damage source. In the first step, the sound velocity was compensated by combining the time-frequency analysis results with the anisotropy of the experimental specimens, and the four-point circular arc method was used to locate the initial position. In the second step, there is an improvement of the Drosophila optimization algorithm, using the ergodicity of the chaotic algorithm and congestion adjustment mechanism in the fish swarm algorithm. The smoothing parameters and function construction in the probabilistic neural network were optimized, the number of iterations was reduced, the location accuracy was improved, and the damage mode of composite materials was obtained. Then, the damage location was obtained to achieve the purpose of locating the damage source.


Assuntos
Fibra de Carbono/química , Fenômenos Mecânicos , Nanocompostos/química , Acústica , Algoritmos , Teste de Materiais , Modelos Moleculares , Reprodutibilidade dos Testes
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