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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Analys och implementation av batteristyrningssystem för drönare

Torsede, Eric January 2021 (has links)
Ända sedan uppfinnandet av batteriet i slutet av 1700-talet har det funnits en önskan om att de fungerar såväl som möjligt. Battericeller har en finit laddning samt en finit livslängd. Detta är något som experimenteratsmed och utvecklas fram till de celler vi har idag. Cellerna idag har markant högre energidensitet och kapacitetmen det råder fortfarande stor risk för att de skadas och blir oanvändbara vid dålig hantering.Detta är något som det inte fanns en lösning på under de tidigare åren av batterierna och de hade därfören mycket kortare livslängd än dagens batterier. När tekniken progresserade uppfanns batteristyrningsystemet,ett system som hanterar laddning av batteriet, interna temperaturer samt potentiella problem. Batteristyringssytemen(BMS) är idag en otroligt väsentlig del i nästan alla moderna batteridriva saker. Att generera en högspänning för att driva en last är idag ingen svår uppgift, men att lyckas vårda batterierna och få dem att räckaså länge som möjligt är fortfarande en utmaning.Då vi mer och mer går mot eldrivna fordon som bilar, motoryklar och—potentiellt i framtiden—eldrivna flygplan, kommer utvecklingen av batterier och batterisystem vara otroligt viktig. En teknik som blivit allt mervanlig det senaste årtiondet samt en teknik som mycket väl kan appliceras i större skala i framtiden är drönare.Drönare används idag till en rad olika saker som hobby-flygning, övervakning, leveranser med mera. Detta ärnågonting som endast kommer att fortsätta med tanke på deras mångsidighet.Katla aero är ett drönarföretag som är intresserad av just denna vision. Deras drönare ska vara robusta och hauthållighet för att klara av de olika användningsområden och uppgifter som kan tänkas att komma. En stor delav vad som kommer ge drönarna den prestanda som efterfrågas är just batterikapaciten och batterianvändningen. På Katla aero vill man även där att bästa möjliga resultat uppnås med avseende på batterierna i drönarna.Därav görs denna analys och implementation.I detta examensarbetet har en total uppbyggnad av ett batteripack tillsammans med en BMS utförts. Detta system har sedan testats för laddning och urladdning i syftet att på bästa sätt hantera batterier i en drönare.Vidare har en rad olika tester utförts samt en omfattande felanalys.Syftet och målet med detta arbete var att få en djupare förståelse för hur dessa system fungerar och hurde kan optimeras. Arbetet som utförts under de senaste 10 veckorna kommer förhoppningsvis bli behjälpligt förbatterisystemen i Katlas drönare. Det kommer senare i denna rapport ses hur viktigt det är med ett batteristyrningssytem samt vilka potentiella problem som Katlas drönare står inför och hur de kan förhindras.
22

A Smart Battery Management System for Large Format Lithium Ion Cells

Zhu, Wei 23 May 2011 (has links)
No description available.
23

Emulation of Analog Front-End isoSPI communication for Battery Management Systems / Emulering av analog front-end isoSPI-kommunikation för batteristyrsystem

Malachowska, Julia, Nore, Miko January 2021 (has links)
This study aims to investigate how an emulator could be developed as a testing tool for Battery Management Systems (BMS) by emulating the Analog Front­end (AFE) circuit communicating with a control unit for monitoring of Lithium­Ion Batteries. All of the research was conducted in the context of the company Northvolt. By analysing data collected through a questionnaire, it was evident that an emulator testing tool could potentially make the BMS development process significantly more efficient. A demonstrator was developed as a part of the study. It fulfilled almost all of the requirements initially stated, but required the control unit to send commands in a fixed sequence, which the current BMS control unit did not. A fixed sequence would however enable the incorporation of the developed emulator, as well as introducing other advantages such as predictability. The study showed that the most important factor to consider for developing an AFE communication emulator for BMS testing was robustness and repeatability of the timings of the communication signals. / Syftet med denna studie var att undersöka hur ett testverktyg baserat på en emulator skulle kunna utvecklas för batteristyrsystem. Studien genomfördes på batteriföretaget Northvolt. Genom att analysera data insamlad via ett frågeformulär framgick det tydligt att ett testverktyg baserat på en emulator hade god potential att göra utvecklingsprocessen av batteristyrsystem mer effektiv. En prototyp utvecklades som en del av studien. Denna uppfyllde nästan alla de initialt uppsatta kraven, men var anpassad för kommunikation i en fix sekvens, till skillnad från det aktuella systemet hos företaget. Via studien fann man att implementationen av en fix kommunikationssekvens skulle medföra önskvärda egenskaper hos systemet såsom förutsägbarhet. Vidare visade studien att den viktigaste faktorn att ta i beaktning för utveckling av en emulator var robusthet och repeterbarhet hos timingen av kommunikationssignalerna. Detta eftersom kommunkationen mellan enheter förlitar sig på korrekt timing av varje skickad bit för korrekt inlästa meddelanden.
24

A systems approach to transportation infrastructure management: development of a Highway Management System for the Virginia DOT

Kim, Wonkyu 06 June 2008 (has links)
Although there have been warnings about the decline in the U.S. transportation infrastructure for the last two decades, the infrastructure's service condition remains barely above current requirements, and is insufficient to meet future demands of growth and economic development. This deterioration and obsolescence primarily derives from a lack of investment, inappropriate management, and growing travel demands. The objective of this research is to develop a model, using a system dynamics methodology, that serves as an instrumentality for generating scenarios for facilitating highway infrastructure management -- policy-making, planning, budgeting, and programming for the Virginia highway system. The Highway Management System (H~1S) model, developed in this research, is a system dynamics model equipped with capabilities for analyzing and solving the meta-problems related to highway infrastructure planning and management. The HMS consists of five subsystems: 1) Physical Subsystem (Pavement Management System, and Bridge Management System), 2) Evaluation Subsystem, 3) Functional Subsystem, 4) Financial Subsystem, and 5) Administration Subsystem. Through steady state analysis, an understanding of the relationship between state variables and decision variables can be obtained. The nomographs corresponding to the steady state solutions of the HMS are the analytically-based, manual means of gaining understanding by tracing paths from decision variables to state variables. Simulations were performed using the HMS, based on various budget-size and allocation scenarios for the I-81 corridor. The results indicate that the service condition of the highway will be diminished and will return to its pre-expansion condition in several years, if the maintenance budget is not increased according to the expansion. The HMS is a useful tool for decision-makers and engineers attempting to analyze and solve meta-problems related to transportation infrastructure management. The HMS presents a whole picture of the highway system according to various policy options. This systems approach to highway management also can be applied to the management of other infrastructure, and eventually it should be possible to achieve an integrated infrastructure management system. / Ph. D.
25

Algebraicko-geometrické kódy a Gröbnerovy báze / Algebraicko-geometrické kódy a Gröbnerovy báze

Heglasová, Veronika January 2013 (has links)
In this master thesis we introduce algebraic geometry codes (AG codes). Be- sides basic definitions, properties and attributes of AG codes and algebraic ge- ometry we show how to encode AG codes that has nontrivial Abelian group of permutation automorphisms and how to decode one-point AG codes. We also present Hermitian codes, which are example of one-point AG codes with nontriv- ial Abelian group of permutation automorphisms. We demonstrate the method for encoding and the method for decoding on specific Hermitian code. 1
26

Système de mesure d'impédance électrique embarqué, application aux batteries Li-ion / Study of a battery monitoring system for electric vehicle, application for Li-ion batteries

Nazer, Rouba Al 24 January 2014 (has links)
La mesure d'impédance électrique en embarqué sur véhicule est un sujet clé pour améliorer les fonctions de diagnostic d'un pack batterie. On cherche en particulier à fournir ainsi des mesures supplémentaires à celles du courant pack et des tensions cellules, afin d'enrichir les indicateurs de vieillissement dans un premier temps, et d'état de santé et de charge dans un second temps. Une méthode classique de laboratoire pour obtenir des mesures d'impédance d'une batterie est la spectroscopie d'impédance électrochimique (ou EIS). Elle consiste à envoyer un signal sinusoïdal en courant (ou tension) de fréquence variable balayant une gamme de fréquences d'intérêt et mesurer ensuite la réponse en tension (ou courant) pour chaque fréquence. Une technique d'identification active basée sur l'utilisation des signaux large bande à motifs carrés est proposée. En particulier, des simulations ont permis de comparer les performances d'identification de différents signaux d'excitation fréquemment utilisés dans le domaine de l'identification et de vérifier les conditions correspondant à un comportement linéaire et invariant dans le temps de l'élément électrochimique. L'évaluation de la qualité d'estimation est effectuée en utilisant une grandeur spécifique : la cohérence. Cette grandeur statistique permet de déterminer un intervalle de confiance sur le module et la phase de l'impédance estimée. Elle permet de sélectionner la gamme de fréquence où la batterie respecte les hypothèses imposées par la méthode d'identification large bande. Afin de valider les résultats, une électronique de test a été conçue. Les résultats expérimentaux permettent de mettre en valeur l'intérêt de cette approche par motifs carrés. Un circuit de référence est utilisé afin d'évaluer les performances en métrologie des méthodes. L'étude expérimentale est ensuite poursuivie sur une batterie Li-ion soumise à un courant de polarisation et à différents états de charge. Des essais comparatifs avec l'EIS sont réalisés. Le cahier de charge établi à l'aide d'un simulateur de batterie Li-ion a permis d'évaluer les performances de la technique large bande proposée et de structurer son utilité pour l'estimation des états de vieillissement et de charge. / Embedded electrical impedance measurement is a key issue to enhance battery monitoring and diagnostic in a vehicle. It provides additional measures to those of the pack's current and cell's voltage to enrich the aging's indicators in a first time, and the battery states in a second time. A classical method for battery impedance measurements is the electrochemical impedance spectroscopy (EIS). At each frequency, a sinusoidal signal current (or voltage) of a variable frequency sweeping a range of frequencies of interest is at the input of the battery and the output is the measured voltage response (or current). An active identification technique based on the use of wideband signals composed of square patterns is proposed. Particularly, simulations were used to compare the performance of different excitation signals commonly used for system identification in several domains and to verify the linear and time invariant behavior for the electrochemical element. The evaluation of the estimation performance is performed using a specific quantity: the spectral coherence. This statistical value is used to give a confidence interval for the module and the phase of the estimated impedance. It allows the selection of the frequency range where the battery respects the assumptions imposed by the non-parametric identification method. To experimentally validate the previous results, an electronic test bench was designed. Experimental results are used to evaluate the wideband frequency impedance identification. A reference circuit is first used to evaluate the performance of the used methodology. Experimentations are then done on a Li–ion battery. Comparative tests with EIS are realized. The specifications are established using a simulator of Li-ion battery. They are used to evaluate the performance of the proposed wide band identification method and fix its usefulness for the battery states estimation: the state of charge and the state of health.
27

Energibesparing med automatiserad inneklimat- och ventilationsstyrning – drivkrafter och barriärer

Selhammer, Andreas January 2022 (has links)
Energiförbrukningen i Sveriges fastigheter uppgår till närmare 40% av totalprimärenergin för Sverige. Denna siffra förväntas öka ytterligare under den kommande 20-årsperioden. Av denna energimängd motsvarar 67% byggnadens operativa fas. I denna studie undersöks hur energiförbrukning kan minskas genom att införa mera byggnadsautomation och högre automationsgrad. Detta för att få fastigheter i ökad grad att anpassa sina energibehov efter faktiska rådande behov i stället för mer statiska driftfall.  En litteraturgranskning inom forskningsfältet utfördes mot forskningsfråga 1, Finns det en korrelation mellan energibesparing och automationsgrad i inneklimat och ventilationsstyrning? Här har tekniker som building management system (BMS) och building energy management system (BEMS) påvisat besparingar runt 30% vid införande. Vidare har tekniker som digitala tvillingar påvisat besparingar mellan 6,2%- 21,5% samt lägre påverkan på fastighetens brukare. Detta genom ett mer prediktivt underhåll och bättre förhandsanalyser av energieffektiva utfall innan implementering. Även artificiell intelligens (AI) påvisade goda energibesparingar vid införande med energibesparingar mellan 14% - 44%. Här indikerar studien att det finns problem med implementeringen. Detta har sin härkomst i, dels felaktigt konstruerat metadata och för få sensorer som ger AI för litet beslutsfattande underlag att arbete mot. Här har studier funnit att AI införd på en för dålig dataplattform kan bli direkt kontraproduktivt och öka energiförbrukningen i stället för att sänka denna. Dock framkommer det att det finns en positiv koppling mellan energibesparing och automationsgrad. Detta då besparingen ligger i fastighetens förmåga att adaptera sig till rådande omständigheter.  Forskningsfråga 2 avser: Vad föreligger det för hinder och drivkrafter för ökad implementering av automationsgrad i inneklimat och ventilationsstyrning? Gällande barriärer och hinder påvisar svaren från enkätundersökningen utförd i denna studie att det förkommer främst kunskapshinder och ekonomiska hinder för vidare implementering av automation inom fastigheterna. Vidare kan det utrönas att förvaltare och drifttekniker arbetar mer aktivt med energiledningsfrågor än de övriga skråna som undersöks i denna undersökning. Här visar svaren på att framför allt styrentreprenörerna och konsulterna behöver informera i högre grad om den nytta deras lösningar kan erbjuda för energikonservering. Detta på ett sätt som mottagaren förstår och kan relatera till för att motivera prisskillnader initialt i byggprocessen och med detta försöka överbrygga energiparadoxen, där kostnadseffektiva och energieffektiva lösningar uteblir som en konsekvens. / Energy consumption in Sweden, which originates from buildings and facilities, amounts to almost 40% of the total primary energy in Sweden. This figure is expected to increase further over the next 20 years. From this, 67% corresponds to the operational phase of the building. This study examines how this energy consumption can be reduced by increasingly adding a higher degree of building automation into the buildings, to get properties to increasingly adapt their energy needs to the actual prevailing needs instead of a more static operation. A literature review in the research field was performed against research question 1, Is there a correlation between energy saving and degree of automation in indoor climate and ventilation control? Here, technologies such as building management systems (BMS) and building energy management systems (BEMS) had demonstrated savings around 30% upon introduction. By adding technologies such as digital twins have demonstrated savings between 6.2%-21.5% and lower the effect on the occupants’ residences comfort through better predictive maintenance and preliminary analysis of energy and comfort outcomes before real life implementation. AI also showed good energy saving potential with energy reduction between 14.4%-44.36%. However, there are problems that could occur with the implementation, as this study stats. This has its origin in partly incorrectly constructed metadata and a lack of sensors and actuators. This in turn gives the AI insufficient data for training basis and incorrect bases to build their forecasts on. This study also found that AI, or other analysis tools, on an insufficient databased platform can be directly counterproductive and increase energy consumption instead. However, it appears that there is a positive connection between energy saving and degree of automation. This is because the savings lie in the property's ability to adapt to prevailing circumstances. Research question 2 refers to what are the obstacles and driving forces for increased implementation of the degree of automation in indoor climate and ventilation control? The answers from the questionnaire show that there are mainly knowledge barriers and financial obstacles for further implementation of automation within the properties. Furthermore, it can be ascertained that facility managers and technicians are more actively engaged with energy management issues than the other guilds in this survey. Here, the answers show that, above all, the automation-contractors and consultants need to provide better information about the benefits if their automation solutions and how it could reduce energy waste and thereby try to bridge the energy paradox, where cost-effective and energy-efficient solutions are overlooked due to hinders and barriers.
28

Síndrome de ardência bucal: estudo duplo cego cruzado placebo-controlado da efetividade do ácido alfa-lipóico sobre a sintomatologia e avaliação da função gustatória / Burning mouth syndrome: double-blind placebo-controlled crossover trial of effectiveness of alpha lipoic acid and taste evaluation

Cavalcanti, Desirée Rosa 02 June 2008 (has links)
A síndrome de ardência bucal (SAB) é uma condição crônica, caracterizada por sensação de ardor bucal sem alterações clinicamente detectáveis. Afeta predominantemente mulheres no período pós-menopausa e sua terapêutica ainda não está estabelecida. Pelo menos dois terços destes pacientes apresentam queixa subjetiva de disgeusia como sintoma secundário associado. O objetivo deste estudo foi avaliar a efetividade do ácido alfa lipóico, como alternativa terapêutica no controle dos sintomas da SAB, por meio de um estudo duplo-cego cruzado, placebocontrolado. Foi realizada também uma investigação da função gustatória destes pacientes, pela aplicação de teste objetivo de reconhecimento dos quatro sabores básicos. Foram incluídos trinta e cinco pacientes (31 mulheres, 4 homens, média de idade 63,1 anos, variação 36-78 anos) e 31 pacientes completaram o estudo terapêutico. Os pacientes foram randomizados para dois ciclos de tratamento um com ácido alfa lipóico e um com placebo, ambos administrados em cápsulas idênticas. Estes ciclos de tratamento foram separados por um período de washout de 20 dias. O sintoma de ardor bucal e a resposta terapêutica foram avaliadas utilizando uma escala visual de sintomatologia (EVS) numérica de 10 pontos antes do início e ao término de cada ciclo e pelo efeito global percebido (EGP), usando uma escala de 5 pontos ao término de cada ciclo de tratamento. O nível de redução sobre o sintoma de ardor avaliado pela EVS foi estatisticamente significante para ambos os tratamentos (31,15% com ácido alfa lipoico e 34,09% ao término do do primeiro ciclo; 12,55% para ácido alfa lipóico e 28,09% para placebo ao término do segundo ciclo). Considerando-se os resultados de EGP dos dois ciclos, 22 pacientes reportaram pelo menos alguma melhora após utilizarem ácido alfa lipóico e 23 pacientes após utilizarem placebo. A comparação dos scores obtidos dos dois ciclos pelo teste t falharam em demonstrar efetividade para ácido alfa lipóico sobre placebo. A queixa subjetiva de disgeusia esteve associada à de ardor em 60% dos casos. No teste objetivo de paladar foram verificados erros de identificação dos sabores básicos em 35,23% das amostras para o amargo, 20% para o azedo, 20% para o doce e 19% para salgado, estes erros foram observados também entre pacientes que não apresentavam a queixa subjetiva de disgeusia. Apenas 5 pacientes (14,28%) conseguiram identificar corretamente os quatro sabores básicos. A maior parte dos erros de identificação ocorreu para o sabor amargo e em baixas concentrações. A análise dos dados obtidos nos permitiu concluir que o ácido alfa lipóico não foi efetivo no controle dos sintomas associados à síndrome de ardência bucal e que existe uma associação da síndrome com as alterações da função gustatória. / The burning mouth syndrome is a chronic condition caractherized by an oral burning sensation without clinical signs. Post menopausean women are mostly affected and the therapy is not stablished. Two thirds or more of these patients shown dysgeusia as a secondary associate complaint. The purpose of this study was to evaluate the effectiveness of alpha lipoic acid in the management of burning mouth syndrome symptoms through a randomized double-blind placebo-controlled crossover trial. In addiction, a preliminary evaluation of taste function was performed by objective test to recognition of the four basic flavors. Thirty-five patients (31 women, 4 men, median age 63.1 years, range 36-78) were included and 31 completed the therapeutic study. The patients were randomized for two cycles of treatmentone with alpha lipoic acid and one with placebo, both administered in identical capsules. These cycles were separated by a washout period of 20 days. The oral symptoms and the treatment response were assessed using a 10 point numerical visual analogue scale (VAS) before and after each cycle and the global perceived effect (GPE) score, using a 5- point scale at the end of each treatment cycle. The level of burning reduction assessed by VAS was significant for both treatments (31.15% with ALA treatment and 34.09% with placebo after first cycle and 12.55% for ALA and 28.09% for placebo after second cycle). Considering the results of GPE in the two cycles together, twenty-two patients reported at least some improvement after alpha lipoic acid use and twenty-three patients after placebo. Comparison of the oral assessment scores of the two cycles with t test failed to demonstrate effectiveness for alpha lipoic acid over placebo. Dysgeusia was associated with burning mouth in 60% of the cases. In the objective taste evaluation, identification errors were observed in 35,23% of the samples for bitter, 20% for sour, 20% for sweet and 19% for salty. Moreover, these errors were observed among patients whose not complain of dysgeusia. Only 5 patients (14,28%) had correct identification of four basic flavors. Most of identifications errors were observed in bitter taste and in lower concentrations. We concluded that alpha lipoic acid was not effective in the control of burning mouth syndrome symptoms in this study and there is a relation of taste disfunction with the syndrome.
29

Development of an advanced electrical system for a solar powered racing vehicle with an emphasis on the battery protection and management system

Engelkemeir, Frederick Donald 11 July 2011 (has links)
This thesis describes the development of an electrical system for a solar powered racing vehicle with en emphasis on the Battery Protection System (BPS). This battery protection system was designed for the UTSVT’s (University of Texas Solar Vehicles Team) solar powered vehicle, the Samsung Solorean. The system is required due to the dangers of the lithium-ion cobalt battery chemistry. The system monitors the voltage, temperature, and current of each battery module in the 22 module battery pack and will physically isolate the pack from the rest of the vehicle with a high-current electromechanical contactor if any parameter is outside of the safe range. The system can be expanded to monitor any number of series battery cells. The system uses a master-slave microcontroller architecture with a single master microcontroller that interrogates several slave microcontroller boards for readings over a common serial bus. The system uses a new voltage sensing ASIC to monitor cell voltages, along with an analog current output device to measure temperature and a hall-effect device to measure current. The system was a complete success and has allowed the UT solar car to finish the American Solar Challenge cross-country “Rayce.” / text
30

Síndrome de ardência bucal: estudo duplo cego cruzado placebo-controlado da efetividade do ácido alfa-lipóico sobre a sintomatologia e avaliação da função gustatória / Burning mouth syndrome: double-blind placebo-controlled crossover trial of effectiveness of alpha lipoic acid and taste evaluation

Desirée Rosa Cavalcanti 02 June 2008 (has links)
A síndrome de ardência bucal (SAB) é uma condição crônica, caracterizada por sensação de ardor bucal sem alterações clinicamente detectáveis. Afeta predominantemente mulheres no período pós-menopausa e sua terapêutica ainda não está estabelecida. Pelo menos dois terços destes pacientes apresentam queixa subjetiva de disgeusia como sintoma secundário associado. O objetivo deste estudo foi avaliar a efetividade do ácido alfa lipóico, como alternativa terapêutica no controle dos sintomas da SAB, por meio de um estudo duplo-cego cruzado, placebocontrolado. Foi realizada também uma investigação da função gustatória destes pacientes, pela aplicação de teste objetivo de reconhecimento dos quatro sabores básicos. Foram incluídos trinta e cinco pacientes (31 mulheres, 4 homens, média de idade 63,1 anos, variação 36-78 anos) e 31 pacientes completaram o estudo terapêutico. Os pacientes foram randomizados para dois ciclos de tratamento um com ácido alfa lipóico e um com placebo, ambos administrados em cápsulas idênticas. Estes ciclos de tratamento foram separados por um período de washout de 20 dias. O sintoma de ardor bucal e a resposta terapêutica foram avaliadas utilizando uma escala visual de sintomatologia (EVS) numérica de 10 pontos antes do início e ao término de cada ciclo e pelo efeito global percebido (EGP), usando uma escala de 5 pontos ao término de cada ciclo de tratamento. O nível de redução sobre o sintoma de ardor avaliado pela EVS foi estatisticamente significante para ambos os tratamentos (31,15% com ácido alfa lipoico e 34,09% ao término do do primeiro ciclo; 12,55% para ácido alfa lipóico e 28,09% para placebo ao término do segundo ciclo). Considerando-se os resultados de EGP dos dois ciclos, 22 pacientes reportaram pelo menos alguma melhora após utilizarem ácido alfa lipóico e 23 pacientes após utilizarem placebo. A comparação dos scores obtidos dos dois ciclos pelo teste t falharam em demonstrar efetividade para ácido alfa lipóico sobre placebo. A queixa subjetiva de disgeusia esteve associada à de ardor em 60% dos casos. No teste objetivo de paladar foram verificados erros de identificação dos sabores básicos em 35,23% das amostras para o amargo, 20% para o azedo, 20% para o doce e 19% para salgado, estes erros foram observados também entre pacientes que não apresentavam a queixa subjetiva de disgeusia. Apenas 5 pacientes (14,28%) conseguiram identificar corretamente os quatro sabores básicos. A maior parte dos erros de identificação ocorreu para o sabor amargo e em baixas concentrações. A análise dos dados obtidos nos permitiu concluir que o ácido alfa lipóico não foi efetivo no controle dos sintomas associados à síndrome de ardência bucal e que existe uma associação da síndrome com as alterações da função gustatória. / The burning mouth syndrome is a chronic condition caractherized by an oral burning sensation without clinical signs. Post menopausean women are mostly affected and the therapy is not stablished. Two thirds or more of these patients shown dysgeusia as a secondary associate complaint. The purpose of this study was to evaluate the effectiveness of alpha lipoic acid in the management of burning mouth syndrome symptoms through a randomized double-blind placebo-controlled crossover trial. In addiction, a preliminary evaluation of taste function was performed by objective test to recognition of the four basic flavors. Thirty-five patients (31 women, 4 men, median age 63.1 years, range 36-78) were included and 31 completed the therapeutic study. The patients were randomized for two cycles of treatmentone with alpha lipoic acid and one with placebo, both administered in identical capsules. These cycles were separated by a washout period of 20 days. The oral symptoms and the treatment response were assessed using a 10 point numerical visual analogue scale (VAS) before and after each cycle and the global perceived effect (GPE) score, using a 5- point scale at the end of each treatment cycle. The level of burning reduction assessed by VAS was significant for both treatments (31.15% with ALA treatment and 34.09% with placebo after first cycle and 12.55% for ALA and 28.09% for placebo after second cycle). Considering the results of GPE in the two cycles together, twenty-two patients reported at least some improvement after alpha lipoic acid use and twenty-three patients after placebo. Comparison of the oral assessment scores of the two cycles with t test failed to demonstrate effectiveness for alpha lipoic acid over placebo. Dysgeusia was associated with burning mouth in 60% of the cases. In the objective taste evaluation, identification errors were observed in 35,23% of the samples for bitter, 20% for sour, 20% for sweet and 19% for salty. Moreover, these errors were observed among patients whose not complain of dysgeusia. Only 5 patients (14,28%) had correct identification of four basic flavors. Most of identifications errors were observed in bitter taste and in lower concentrations. We concluded that alpha lipoic acid was not effective in the control of burning mouth syndrome symptoms in this study and there is a relation of taste disfunction with the syndrome.

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