This thesis work contains electrical transport and low frequency (1/f) noise measurements in ultrathin graphene and Molybdenum disulphide (MoS2) field effect transistors (FET). From the measurements, We mainly focus on the origin of disorder in both the materials. To address the orgin of disorder in graphene, we study single and bilayer graphene-FET devices on SiO2 substrate. We observe that both conductivity and mobility are mainly determined by substrate induced long range, short range, and polar phonon scattering. For further confirmation, we fabricate suspended graphene devices which show extremely high mobility. We find that, in contrast to substrate-supported graphene, conductivity and mobility in suspended graphene are governed by the longitudinal acoustic phonon scattering at high temperature and the devices reach a ballistic limit at low temperature. We also conduct low frequency 1/f noise measurements, known to be sensitive to disorder dynamics, to extract more information on the nature of disorder. The measurements are carried out both in substrate-supported and suspended graphene devices. We find that 1/f noise in substarted graphene is mainly determined by the trap charges in the SiO2 substrate. On the other hand, noise behaviour in suspended graphene devices can not be explained with trap charge dominated noise model. More-over, suspended devices exhibit one order of magnitude less noise compared to graphene on SiO2 substrate. We believe noise in suspended graphene devices probably originate from metal-graphene contact regions. In the second part of our work, We present low temperature electrical transport in ultrathin MoS2 fields effect devices, mechanically exfoliated onto Si/SiO2 substrate. Our experiments reveal that the electronic states in MoS2 are localized well up to the room temperature over the experimentally accessible range of gate voltage. This manifests in two dimensional (2D) variable range hopping (VRH) at high temperatures, while below ~ 30 K the conductivity displays oscillatory structures in gate voltage arising from resonant tunneling at the localized sites. From the correlation energy (T0) of VRH and gate voltage dependence of conductivity, we suggest that the charged impurities are the dominant source of disorder in MoS2. To explore the origin of the disorder, we perform temperature dependent I - V measurements at high source-drain bias. These measurements indicate presence of an exponentially distributed trap states in MoS2 which originate from the structural inhomogeneity. For more detailed investigation, we employ 1/f noise which further confirms possible presence of structural disorder in the system. The origin of the localized states is also investigated by spectroscopic studies, which indicate a possible presence of metallic 1T-patches inside semiconducting 2H phase. From all these evidences, we suggest that the disorder is internal, and achieving high mobility in MoS2 FET requires a greater level of crystalline homogeneity.

Exponering av det lågfrekventa ELF (Extremely low frequency) magnetfältet som genereras vid dagens elnät är något som är relativt nytt för människokroppen och den ökar ständigt i och med den tekniska utvecklingen. Eftersom det inte finns ett klart svar på hur fältet påverkar kroppen så tillämpas försiktighet för att hålla exponeringsnivåerna nere och försäkra sig om att ingen skada sker. Med hjälp av tidigare forskning inom området och uppmätta värden från olika anläggningar samt överslagsberäkningar har ett verktyg i Excel tagits fram för att kunna uppskatta magnituden av magnetfältet. Verktyget innehåller information om styrkan på magnetfältet från transformatorer, ställverk, elcentraler, kraftledningar och kanalskenor. Användaren skriver in ett antal parametrar för att få utdata om hur starkt magnetfältet är på olika avstånd ifrån källan. Detta presenteras i form av en tabell och en graf för respektive utrustning. Eftersom magnetfält alstras beroende på strömmens riktning, påverkar själva geometrin i olika elanläggningar magnetfältets styrka. För att beräkna exakta värden krävs då avancerade simuleringsprogram. Med detta verktyg kan projektörer redan vid ett tidigt skede uppskatta magnetfältet. / The exposure of ELF (Extremely low frequency) magnetic field generated by today’s electrical power system, is something that is relatively new to the human body and it is constantly increasing as more technology is developed. As there is no clear answer on how the field actually affects the body, a measure of caution is applied to ensure that the exposure levels are kept down to make sure no harm is done. With the help of previous research in the field, measured values from different locations and approximate calculations, a tool was developed in Excel to estimate the magnitude of the magnetic fields. The tool provides information about the magnitude of magnetic fields from transformers, switchgears, switchboards, powerlines and busbars. The user enters a number of parameters and the tool provides output data with the magnitude of the magnetic field at different distances from the source. This is presented in the form of a table and a graph for each equipment. Since the magnetic field is generated depending on the currents direction, the actual geometry of the electrical system needs to be taken in consideration when calculating the exact magnetic field. This requires an advanced simulation software to be accurate. With this tool, designers have the opportunity to estimate the magnetic fields at an early stage of development.

Exponering av det lågfrekventa ELF (Extremely low frequency) magnetfältet som genereras vid dagens elnät är något som är relativt nytt för människokroppen och den ökar ständigt i och med den tekniska utvecklingen. Eftersom det inte finns ett klart svar på hur fältet påverkar kroppen så tillämpas försiktighet för att hålla exponeringsnivåerna nere och försäkra sig om att ingen skada sker. Med hjälp av tidigare forskning inom området och uppmätta värden från olika anläggningar samt överslagsberäkningar har ett verktyg i Excel tagits fram för att kunna uppskatta magnituden av magnetfältet. Verktyget innehåller information om styrkan på magnetfältet från transformatorer, ställverk, elcentraler, kraftledningar och kanalskenor. Användaren skriver in ett antal parametrar för att få utdata om hur starkt magnetfältet är på olika avstånd ifrån källan. Detta presenteras i form av en tabell och en graf för respektive utrustning. Eftersom magnetfält alstras beroende på strömmens riktning, påverkar själva geometrin i olika elanläggningar magnetfältets styrka. För att beräkna exakta värden krävs då avancerade simuleringsprogram. Med detta verktyg kan projektörer redan vid ett tidigt skede uppskatta magnetfältet. / The exposure of ELF (Extremely low frequency) magnetic field generated by today’s electrical power system, is something that is relatively new to the human body and it is constantly increasing as more technology is developed. As there is no clear answer on how the field actually affects the body, a measure of caution is applied to ensure that the exposure levels are kept down to make sure no harm is done. With the help of previous research in the field, measured values from different locations and approximate calculations, a tool was developed in Excel to estimate the magnitude of the magnetic fields. The tool provides information about the magnitude of magnetic fields from transformers, switchgears, switchboards, powerlines and busbars. The user enters a number of parameters and the tool provides output data with the magnitude of the magnetic field at different distances from the source. This is presented in the form of a table and a graph for each equipment. Since the magnetic field is generated depending on the currents direction, the actual geometry of the electrical system needs to be taken in consideration when calculating the exact magnetic field. This requires an advanced simulation software to be accurate. With this tool, designers have the opportunity to estimate the magnetic fields at an early stage of development.

Healthy ageing has been found to be accompanied by changes in slow wave activity (SWA) and cognitive function. Furthermore, these changes have been seen predominantly in the prefrontal cortex (PFC) compared to other regions of the cortex. Current theories of cognitive ageing propose that this occurs due to a specified deterioration of neuronal substrates of the PFC, and as such, changes in SWA and cognitive function may decline at similar rates due to similar underlying aetiology. The main aim of the current thesis was to explore age-related differences in electroencephalographic (EEG) SWA during the first NREM period and cognitive performance that relies on the integrity of the PFC: executive function and social cognition. The extent to which executive function (reliant on dorsolateral PFC areas) and social cognitive function (reliant on ventromedial PFC regions) show similar age-related deterioration was investigated in Study 1. Here, 16 young (22.2 years) and 16 older (71.5 years) adults were administered with a cognitive testing battery including executive function measures: Verbal Fluency (VF) and Tower of London (TOL); as well as measures of social cognition: Go/No-go, Emotional Prosody and Ekman 60 Faces. Not all measures of PFC function were affected to the same extent. The older group performed significantly worse on the TOL, but not on the VF test. Additionally, simple aspects of social cognition did not display differences between the groups, but the older group performed significantly worse than the young group on more complex aspects of recognition of emotion from facial expression (Ekman 60 Faces) and Emotional Prosody. As most studies of cognitive ageing are cross-sectional and show large agerelated changes, the remainder of this thesis focused on age-related changes using a longitudinal design over a relatively small ageing period (mean = 6.29 years). The average age of participants at baseline was 67.1 years and the average age at follow-up was 73.4 years. In Study 2, in a sample of 11 participants, performance on executive function tests was measured (TOL, VF and Wisconsin Card Sorting Test: WCST). As found in the cross-sectional analyses reported in Study 1, the TOL task was found to be the most sensitive indicator of age-related changes, as this showed a decline with age; whereas, VF and WCST remained stable over time. Furthermore, in Study 3, localised SWA was recorded via EEG, and significant declines were found in low frequency delta (0.5 – 1 Hz), which was localised to the left frontal region.

Population growth and urbanization are projected by the United Nations to add 2,5 billionpeople to the world’s urban population by 2050. We need to construct buildings in anunprecedented scale to meet global housing demand. Sustainable development is critical.Compared to traditional heavy constructions, lightweight wooden constructions are moreenvironmentally friendly and will play a key role in meeting future demands. However, thereare two major problems with lightweight constructions that need to be addressed: 1) Limitedlow frequency sound insulation and 2) Variations in sound insulation.Annoyance from walking sound tend to be higher in lightweight than in heavy constructionseven with the same measured sound insulation. The Swedish research program AkuLiteindicated that the correlation between measured sound insulation and annoyance wassignificantly improved by extending current evaluation methods from 50 Hz down to 20 Hz.Secondly, large variations in sound insulation between nominally identical lightweightconstructions are common, which leads to larger safety margins. By identifying and quantifyingunderlying causes, production costs can be minimized and the performance can be improved.The aim of the thesis is to develop a new evaluation method for impact sound insulation thatbetter correspond to rated annoyance, and to identify and control underlying causes forvariations in sound insulation. The thesis contains six papers.In Paper I and II, sound insulation measurements were carried out in a large number ofnominally identical rooms of two different industrially prefabricated lightweight woodenconstructions. The purpose was to assess and quantify the variations in impact and airbornesound insulation. In Paper I, 30 nominally identical apartments of a volume based system wasevaluated. The apartments on the highest floor achieved significantly better sound insulationdue to the extra weight on lower floors affecting the elastic connections between stories. InPaper II, 18 rooms of a cross-laminated timber system of plate elements were evaluated.Additionally, several potential parameters related to measurement uncertainty wereinvestigated.Paper III deals with measurement uncertainty. An empirical study of reverberation timemeasurements showed that current methods need to be improved, if sound insulationrequirements are to be extended to 20 Hz.Paper IV and V verified that the frequency range 20-50 Hz is important for walking soundannoyance, and that alternative frequency adaptation terms can improve the correlation betweenmeasured impact sound insulation and annoyance ratings. In Paper IV, the methodology was toperform extensive field measurements in apartment buildings of various construction types andto perform questionnaire surveys among the residents. In Paper V, the methodology was toevaluate annoyance based on binaural recordings of walking sound in a two-part listening test.In Paper VI, 70 measurements in a lightweight wooden system were evaluated to quantify thetotal variations in impact and airborne sound insulation from 20 and 50 Hz, respectively. It wasconcluded that the proposed metrics of impact sound insulation were primarily determined bythe impact sound level 20-40 Hz and that the measurement methods must be evaluatedthoroughly to avoid excessive safety margins. A new evaluation method for impact sound insulation from 25 Hz, that correspond to the ratedannoyance for both heavy and lightweight constructions is proposed. By using the proposedmethod and attending the specific causes for variations, the lightweight industry will be able todevelop improved multi-story dwellings with higher perceived acoustic quality. / <p>Forskningsfinansiärer:</p><p>Sven Tyréns Stiftelse</p><p>Formas</p>

Ce travail de thèse concerne l’étude de différents revêtements type « Diamond-Like Carbon » élaborés par un procédé CVD assisté par un plasma basse fréquence (40 kHz). Deux revêtements de référence sont d’abord étudiés : des couches de carbone amorphe hydrogéné (a-C:H) et des couches de carbure de silicium amorphe hydrogéné (a-SiC:H). L’évolution de leurs propriétés mécaniques (dureté, module d’Young) et tribologiques (frottement, usure) est décrite en fonction des paramètres du procédé et corrélée à leur microstructure. Les résultats obtenus pour ces deux couches de référence sont ensuite exploités pour proposer deux systèmes complémentaires : des revêtements a-C:H dopées et des systèmes multicouche a-C:H/a-SiC:H. Ces deux solutions présentent des contraintes résiduelles réduites par rapport à un revêtement a-C:H monocouche ce qui permet d’envisager une augmentation importante des épaisseurs de dépôt tout en conservant des propriétés mécaniques et tribologiques intéressantes. Enfin, en vue d’une application industrielle de ces revêtements sur des pièces de moteur par exemple, l’optimisation de leur adhérence par insertion de sous-couches adaptées ainsi que de leurs performances tribologiques en conditions lubrifiées par l’intermédiaire de texturation de surface est alors envisagée / Hydrogenated amorphous carbon films (a-C:H) and hydrogenated silicon carbide films (a-SiC:H) are deposited by low frequency (40 kHz) plasma enhanced chemical vapour deposition (LF PECVD). Structural, mechanical and tribological properties of those single layers have been first studied in relation with process parameters. Then those results have been used to study two other systems. The first one corresponds to silicon doped a-C:H thin films and the second one to multilayered coatings consisting in a stack of a-C:H and a-SiC:H layers. Those coatings offer potential advantages such as lower residual stress level comparing to that of a-C:H stress level which gives the opportunity to deposit thicker films, and also attractive mechanical and tribological properties. Moreover, in case of applications like car engine parts for example, adhesion and tribological properties under lubrication have to be improved. Solutions as incorporating underlayer or texturing surface are thus also investigated in this study

O sistema atmosfera-gelo marinho é complexo e fortemente acoplado. Em uma região de transição entre a cobertura de gelo marinho e o mar aberto a interação entre esse sistema é particularmente intensa, sendo significativa o suficiente para influenciar a circulação atmosférica de grande escala e a distribuição de gelo marinho. Assim, o objetivo principal deste trabalho foi analisar as interações entre os ciclones extratropicais e a variabilidade extrema do gelo marinho nos setores dos mares de Bellingshausen-Amundsen (MBA) e do mar de Weddell (MW), no período de verão e inverno austral entre 1989 e 2007. Foram utilizados dados de extensão de gelo marinho do NSIDC/NASA; campos atmosféricos da superfície até os altos níveis da troposfera das reanálises do ERA-Interim (ECMWF); composição de imagens de satélite do canal infravermelho do SSEC; Índice de Niño Oceânico do CPC/NOAA. As anomalias de alta frequência (período de 2-10 dias) e interanual (período maior que 370 dias) foram obtidas aplicando-se a transformada rápida de Fourier nas séries temporais (1989-2007). Os extremos de gelo marinho foram obtidos através do primeiro e terceiro quartil da distribuição dos dados. As características da circulação atmosférica de alta frequência e interanual associadas aos eventos extremos negativos (ENGM) e positivos (EPGM) de gelo marinho, na mesma escala de tempo, foram obtidas através de composições defasadas das anomalias dos campos atmosféricos. Para evidenciar e exemplificar os padrões encontrados nas composições de alta frequência apresenta-se uma análise sinótica de estudo de casos para o setor dos MBA durante o inverno austral, em eventos ENGM e EPGM, separando os casos em fases distintas do fenômeno tropical El Niño. Foi utilizada a estatística de ciclones do Automatic Cyclone Tracking, da Universidade de Melbourne, para analisar a ocorrência de ciclones associados aos períodos de mínima e máxima extensão de gelo marinho na escala interanual. Os resultados mostram que no verão e inverno austral, os eventos ENGM de alta frequência no setor dos MBA e do MW estão associados com as anomalias dos campos atmosféricos, na mesma escala temporal, que se assemelham a um trem de ondas ocorrido a partir de três dias anteriores ao evento extremo. A anomalia ciclônica no oeste e a anomalia anticiclônica no leste do setor resultam em uma anomalia de ventos de norte e, consequentemente, a anomalias positivas de temperatura do ar. Essa configuração anômala contribui para os eventos ENGM através do derretimento do gelo marinho e do seu próprio transporte em direção às latitudes maiores pelos ventos de norte anômalos. As anomalias de alta frequência dos campos atmosféricos em todos os casos (composições defasadas) de eventos EPGM apresentam fases opostas em relação aos eventos ENGM. Portanto, fases distintas do trem de ondas induzem na modulação de extremos de gelo marinho opostos. Em relação às análises sinóticas dos eventos ENGM e EPGM em fases distintas do fenômeno El Niño, verificou-se que em períodos de El Niño há uma intensificação do jato subtropical e um enfraquecimento do jato polar no Pacífico Sul. Há uma menor atuação dos ciclones extratropicais, predominando o sistema de cristas e cavados. Na fase de La Niña há um reforço do jato polar e uma intensa atividade ciclônica sobre os MBA. No evento ENGM (EPGM) há uma associação entre os ventos de norte (de sul) com a vanguarda (retaguarda) dos sistemas ciclônicos em superfície. Na fase Neutra verificou-se uma intensificação do jato polar e uma atuação do sistema de cristas/cavados e de sistemas ciclônicos em superfície. Na análise da influência da circulação atmosférica interanual na variabilidade extrema do gelo marinho, na mesma escala de tempo, observou-se que a fase quente (fria) do ENSO provavelmente está associada com eventos ENGM (EPGM) nos MBA e com eventos EPGM (ENGM) no MW. Sobre a influência da variabilidade interanual da extensão do gelo marinho na atividade ciclônica, nas composições de anomalias interanuais de PNMM em relação aos eventos ENGM nos MBA (lag = 0) no verão, há um predomínio de anomalias positivas de pressão ao nível médio do mar (PNMM) sobre grande parte do Oceano Austral, o que contribuiria para uma menor profundidade e raio dos sistemas em superfície. Já em relação aos eventos ENGM no MW, verifica-se que no lag = 0 há um predomínio de anomalias negativas de PNMM no Oceano Austral, o que contribuiria para um aumento da profundidade e raio dos ciclones. / The sea ice-atmosphere system is complex and tightly coupled. In a transition region between the coverage of sea ice and open ocean the interaction between this system is particularly intense, being significant enough to influence large-scale atmospheric circulation and sea ice distribution. Thus, the main objective of this study was to analyze the interactions between extratropical cyclones and extreme variability of sea ice in the sectors of the Bellingshausen-Amundsen Seas (BAS) and the Weddell Sea (WS), in the period of austral summer and winter between 1989 and 2007. We used sea ice extent data from NSIDC/NASA; atmospheric fields (surface to higher tropospheric levels) from ERA-Interim reanalysis; SSEC IR satellite image composition; and the Oceanic Niño Index CPC/NOAA. Anomalies of high-frequency (2-10 days) and interannual (longer than 370 days) were obtained by applying a fast Fourier transform in the time series (1989-2007). The extremes of sea ice were obtained from the first and third quartile of the data distribution. The characteristics of high-frequency atmospheric circulation and interannual associated with negative (NESI) and positive (PESI) extreme events of sea ice at the same time scale, were obtained from the lagged composites of the anomalies of atmospheric fields. To highlight and illustrate the patterns found in the composites of high frequency presents a synoptic analysis of case studies for the sector of the BAS during the austral winter at NESI and PESI events, separating the cases in different stages of the tropical El Niño phenomenon. Was used a statistical cyclone of Automatic Cyclone Tracking, from University of Melbourne, to analyze the occurrence of cyclones associated with periods of minimum and maximum extent of sea ice in the interannual scale. The results show that in the austral summer and winter, the NESI events of high frequency in the sector of the BAS and the WS are associated with the anomalies of atmospheric fields in the same timescale that resemble a wave train occurring from three days before the extreme event. The cyclonic anomaly in the west and anticyclonic anomaly in the east sector result in an anomaly of north winds and, consequently, the positive anomalies of air temperature. This anomalous configuration contributes for events NESI by sea ice melting and its own transport to higher latitudes by anomalous north winds. Synoptic atmospheric fields anomalies, in all PESI event cases are in opposite phases to NESI events. Therefore, different phases of the circumpolar wave train induce modulation of concurrent sea ice extremes. Regarding the synoptic analysis of events NESI and PESI in different phases of El Niño, it was found that during periods of El Niño it has a strengthening of the subtropical jet and a weakening of the polar jet in the South Pacific. There is less activity of extratropical cyclones, and the predominant system of ridge and troughs. In the La Niña case studies, has a strengthening of the polar jet and an intense cyclonic activity over the BAS. In the NESI (PESI) event there is an association between the north (south) winds at the vanguard (rear) of the cyclone systems at surface. In the Neutral phase case studies, there is an intensification of the polar jet and performance of the system of ridge/troughs and cyclonic systems at surface. In the analysis of the influence of interannual atmospheric circulation on extreme variability of sea ice, at the same time scale, it was observed that the warm (cold) phase of ENSO are probably associated with NESI (PESI) events at BAS and with PESI (NESI) events in the WS. On the influence of interannual variability of sea ice extent in the cyclonic activity, in the composites of interannual anomalies of mean sea level pressure (MSLP) in relation to NESI events in the BAS (lag = 0) in the summer, there is a predominance of positive anomalies of MSLP over much of the Southern Ocean, which would contribute to a lower depth and radius of the surface systems. In relation to NESI events in WS, it appears that in the lag = 0 there is a predominance of negative anomalies of MSLP in the Southern Ocean, which would contribute to an increase in depth and radius cyclones.

Computational modeling offers better insight into a wide range of bioelectrical and biomechanical problems with improved tools for the design of medical devices and the diagnosis of pathologies. Electromagnetic modeling at low and high frequencies is particularly necessary. Modeling electromagnetic, structural, thermal, and acoustic response of the human body to different internal and external stimuli is limited by the availability of numerically efficient computational human models. This study describes the development to date of a computational full-body human model - Visible Human Project (VHP) - Female Model. Its unique feature is full compatibility both with MATLAB and specialized FEM computational software packages such as ANSYS HFSS/Maxwell 3D. This study also describes progress made to date in using the newly developed tools for segmentation. A visualization tool is implemented within MATLAB and is based on customized version of the constrained 2D Delaunay triangulation method for intersecting objects. This thesis applies a VHP - Female Model to a specific application, transcranial Direct Current Stimulation (tDCS). Transcranial Direct Current Stimulation has been beneficial in the stimulation of cortical activity and treatment of neurological disorders in humans. The placement of electrodes, which is cephalic versus extracephalic montages, is studied for optimal targeting of currents for a given functional area. Given the difficulty of obtaining in vivo measurements of current density, modeling of conventional and alternative electrode montages via the FEM has been utilized to provide insight into the tDCS montage performance. An insight into future work and potential areas of research, such as study of bone quality have been presented too.

Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2017-02-07T20:27:42Z No. of bitstreams: 1 2010 - Andrea Cec?lia Sicotti Maas.pdf: 2297895 bytes, checksum: 356a05153807fe7b25a4fd3042b79964 (MD5) / Made available in DSpace on 2017-02-07T20:27:42Z (GMT). No. of bitstreams: 1 2010 - Andrea Cec?lia Sicotti Maas.pdf: 2297895 bytes, checksum: 356a05153807fe7b25a4fd3042b79964 (MD5) Previous issue date: 2010-12-16 / CNPq / Studies envolving bioacustic have strongly collaborated for understanding phylogenetics, ontogenetics, environmental and behavioural processes. Vocal communication is important for the bats for navigation and food attainment, nevertheless represents a key aspect for social interactions. Several studies have demonstrated characteristics of echolocation vocalizations and other types of audio signals. However, few studies have been described with respect to of distress calls. Among these studies have described the vocalizations of distress calls as being of animals in situations of extreme danger, such as when the animal is caught by a predator or even when it is contained by a researcher. Some authors have offered hypotheses to explain a general convergence in the structure of vocalizations produced by birds and mammals in similar behavioral contexts. However, there are few studies have been done on the distress calls in bats. The present general study's objective is to produce and analyze a database for bioacoustics in the context distress vocalizations emitted by bats, analyze and describe the acoustic properties of distress vocalizations in bats of the subfamily Stenodermatinae. Data collection investigations have been carried out in five different locations within the southeast region of Brazil. For this study, were recorded vocalizations of bats in subfamily Stenodermatinae: Artibeus cinereus, Artibeus fimbriatus, A. planirostris, A. obscurus, A. lituratus, Platyrrhinus lineatus, P. recifinus and Vampyressa pusilla. The vocalizations were analyzed using the analysis system Raven v1.3. For analysis, we selected 30 calls of each individual. The following parameters were measured: Types of signs, bands tonal, duration of the signal, and interval of Pre-pulse, interval of post-pulse, minimum frequency, maximum frequency, initial frequency, maximum frequency and peak frequency. For a description of the acoustic parameters were averaged, standard deviation and coefficient of variation values of each of the measured parameters of vocalizations for each species. Through the analysis, we identify two basic types of notes for this noise present in the calls of distress among the species. The results presented here showed that the acoustic parameters corroborate other work in this same context, ie: distress vocalizations of the bat species studied may be the motivation of aggression, as the code calling the motivational structure, characterized in general for they present low frequency, in wide bands and loaded of noises. / As pesquisas com bioac?stica t?m colaborado na compreens?o de processos filogen?ticos, ontogen?ticos, ecol?gicos e comportamentais. Para os morcegos, a comunica??o vocal ? importante para navega??o e obten??o de alimentos, al?m de ser um aspecto chave nas intera??es sociais. V?rios estudos t?m demonstrado caracter?sticas de vocaliza??es de ecolocaliza??o e outros tipos de sinais aud?veis. Por?m, poucos estudos t?m sido descritos com rela??o ?s chamadas de distress. Dentre esses estudos t?m-se descrito as vocaliza??es de distress como sendo chamadas de animais em situa??es de extremo perigo, tais como quando esse animal ? capturado por um predador ou mesmo quando ? contido por um pesquisador. Alguns autores t?m apresentado hip?teses para explicar uma converg?ncia geral na estrutura das vocaliza??es produzidas por p?ssaros e mam?feros em contextos comportamentais similares. H?, entretanto, poucos estudos sendo desenvolvidos sobre as chamadas de distress em morcegos. O presente estudo tem como objetivo geral ? elabora??o e an?lise de um banco de dados bioac?sticos para vocaliza??es no contexto distress, emitidas por morcegos filostom?deos, analisar e descrever as propriedades ac?sticas das vocaliza??es de distress em morcegos da subfam?lia Stenodermatinae. As coletas dos dados bioac?sticos foram realizadas em cinco locais diferentes dentro da regi?o sudeste do Brasil. Para o presente estudo, foram gravadas vocaliza??es de morcegos da Subfam?lia Stenodermatinae: Artibeus cinereus, Artibeus fimbriatus, A. planirostris, A. obscurus, A. lituratus, Platyrrhinus lineatus, P. recifinus e Vampyressa pusilla. As vocaliza??es foram analisadas utilizando o sistema de an?lise Raven v1.3. Para an?lise, foram selecionadas 30 chamadas de cada indiv?duo. Os seguintes par?metros foram mensurados: Tipos de Sinais, bandas tonais, dura??o do sinal, Intervalo do Pr?-pulso, Intervalo do P?s-pulso, freq??ncia m?nima, freq??ncia m?xima, freq??ncia inicial, freq??ncia m?xima e freq??ncia pico. Para a descri??o dos par?metros ac?sticos foram calculados a m?dia, o desvio padr?o e o coeficiente de varia??o dos valores obtidos de cada um dos par?metros medidos das vocaliza??es para cada esp?cie. Atrav?s das an?lises, pudemos identificar dois tipos b?sicos de notas para esta emiss?o sonora presente nas chamadas de distress dentre as esp?cies estudadas. Os resultados aqui apresentados mostraram que os par?metros ac?sticos corroboram com outros trabalhos neste mesmo contexto, ou seja: as vocaliza??es de distress das esp?cies de morcegos estudadas podem representar a motiva??o de agressividade, conforme o c?digo de estrutura motivacional da vocaliza??o, caracterizadas em geral por apresentarem baixa frequ?ncia, em bandas larga e carregada de ru?dos.

No description available.