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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

Inspeção termográfica de danos por impacto em laminados compósitos sólidos de matriz polimérica reforçada com fibras de carbono. / Thermographic inspection of impact damage in solid fiber-reinforced polymer matrix composite laminates.

Almeida, Euripedes Guilherme Raphael de 30 April 2010 (has links)
Laminados compósitos com matrizes poliméricas, respectivamente termorrígida e termoplástica, reforçadas com fibras contínuas de carbono foram submetidos a impacto único transversal com diferentes níveis de energia. Os danos imprimidos aos materiais estruturais foram avaliados por termografia ativa infravermelha na modalidade transmissão. Em geral, os termogramas do laminado termoplástico apresentaram indicações mais claras e bem definidas dos danos causados por impacto, se comparados aos do compósito termorrígido. O aquecimento convectivo das amostras por fluxo controlado de ar se mostrou mais eficaz que o realizado por irradiação, empregando-se lâmpadas incadecentes. Observou-se também que tempos mais longos de aquecimento favoreceram a visualização dos danos. O posicionamento da face impactada do espécime, relativamente à câmera infravermelha e à fonte de calor, não afetou a qualidade dos termogramas no caso do laminado termorrígido, enquanto que influenciou significativamente os termogramas do compósito termoplástico. Os resultados permitiram concluir que a termografia infravermelha é um método de ensaio não-destrutivo simples, robusto e confiável para a detecção de danos por impacto inferior à 5 Joules em laminados compósitos poliméricos reforçados com fibras de carbono. / Continuous carbon fiber-reinforced thermosetting and thermoplastic composite laminates were exposed to single transversal impact with different energy levels. The damages marked to the structural materials were evaluated by active infrared thermography in transmission mode. In general, the thermoplastic laminate thermograms showed more clear and delineated damage indications when compared to the ones from thermosetting composite. The convective heating of the samples by controlled hot air flow was more efficient than via irradiation using lamp. It was also observed that longer heating times improved the damage visualization. The positioning of the specimen´s impacted face regarding the infrared camera and the heating source did not affect the thermo-imaging of thermosetting specimens, whereas it substantially influenced the thermograms of thermoplastic laminates. The results allow concluding that infrared thermography is a simple, robust and trustworthy methodology for detecting impact damages as light as 5 Joules in carbon fiber composite laminates.
22

AnÃlise comparativa das temperaturas das polpas digitais entre gestantes hipertensas e normativas usando termografia de infravermelho / Comparative analysis of temperatures of fingertips between normotensive and hypertensive pregnant women using infrared thermography.

Francisco Eristow Nogueira 30 April 2010 (has links)
Os dados do MinistÃrio da SaÃde apontam a hipertensÃo arterial (HA) como a maior causa de morte materna no Brasil, sendo responsÃvel por 35% da taxa de 140-160 mortes maternas por 100.000 nascidos vivos, sendo sua origem, ainda, motivo de discussÃo. Com a finalidade de buscar novos elementos que permitam o entendimento desta patologia, comparamos as mÃdias das temperaturas das polpas digitais (Tp) de 81 gestantes, 50 normotensas (grupo A) e 31 hipertensas (grupo B), obtidas com termografia de infravermelho. O coeficiente de Pearson mostrou correlaÃÃo positiva entre a pressÃo arterial mÃdia e a pressÃo arterial sistÃlica (r= 0,95), pressÃo arterial diastÃlica (r=0,98) e para a mÃdia das temperaturas cutÃneas das polpas digitais (r=0,98 ). O teste t de student usado para comparaÃÃo de Tp dos grupos A e B foi estatisticamente significante (p = 0,002). A sensibilidade foi de 80%, especificidade de 48%, o VPP de 49%, o VPN de 80%, acurÃcia de 60,5%. A chance de uma paciente estar hipertensa para uma Tp acima de 34,1ÂC à de 1,6 vezes maior. ConcluÃmos a partir dos dados analisados que a mÃdia das Tp de gestantes normotensas à significativamente menor que as mÃdias das Tp de gestantes hipertensas, e que a Tp medida com termografia de infravermelho pode ser um bom preditor para triagem de pacientes normotensas que podem tornar-se hipertensas no decorrer da gravidez. / The Brasilian Healt Ministry data points out arterial hypertension (AH) as the major cause of maternal death, representing 35% of 140-160 maternal deaths for 100.000 alive newborns. Its origin remains a cause for discussion. Looking for new elements that may improve the understanding of that pathology, we studied the skin fingertips mean temperature (Tp) of pregnant women, 50 normotense (group A) and 31 hypertense (group B). The values of temperature were obtained using infrared thermography. Pearson correlation coefficient showed positive relationship between mean arterial pressure and systolic pressure (r= 0,95), diastolic arterial pressure (r=0,98) and for Tp (r=0,98 ). Student t test was statistically significant (p = 0,002) when comparing means of groups A and B. Other statistical tests obtained were: sensibility 80%, specificity de 48%, positive predictive value 49%, negative predictive value 80% and accuracy 60,5%. The chance of a pregnant woman become hypertensive is 1,6 times higher when her Tp is equal or higher then 34,1ÂC. The analyzed data indicate that Tp values of pregnant women measured with infrared thermography is statistically smaller in the group of non hypertense and that may it might become a good method to detect pregnant women with high risk to become hypertensive during pregnancy.
23

Use of Drone and Infrared Camera for a Campus Building Envelope Study

Ariwoola, Raheem Taiwo 01 May 2016 (has links)
Presently, there are concerns that buildings in the USA under-performs in terms of energy efficiency when compared with the original design specifications. A significant percentage of the energy loss in these buildings is associated with the building’s envelope. This study provides a qualitative and analytical understanding of the R-value, which indicates the thermal performance of the elements that make up a building envelope. Infrared thermography is used as a methodology to assess the thermal performance of envelopes of ten buildings on East Tennessee State University Campus. A Fluke Ti25 infrared hand-held camera and a DJI phantom-2 drone mounted with FLIR Vue Pro infrared camera were used for data collection. Data analyses were carried out using ‘Smartview’ and ‘FLIR Reporter Pro’ software. The data analyses revealed energy loss, insulation deficiencies, the associated energy costs of the inefficiencies and the potential savings that could result from correcting these deficiencies in the evaluated building’s envelopes.
24

Automatic Features Identification with Infrared Thermography in Fever Screening

Surabhi, Vijaykumar 12 January 2012 (has links)
The goal of this thesis is to develop an algorithm to process infrared images and achieve automatic identification of moving subjects with fever. The identification is based on two main features: the distinction between the geometry of a human face and other objects in the field of view of the camera, and the temperature of the radiating object. Infrared thermography is a remote sensing technique used to measure temperatures based on emitted infrared radiation. Applications include fever screening in major public places such as airports and hospitals. Current accepted practice of screening requires people to stay in a line and temperature measurements are carried out for one person at a time. However in the case of mass screening of moving people the accuracy of the measurements is still under investigation. An algorithm constituting of image processing to threshold objects based on the temperature, template matching and hypothesis testing is proposed to achieve automatic identification of fever subjects. The algorithm was first tested on training data to obtain a threshold value (used to discriminate between face and non face shapes) corresponding to a false detection rate of 5%, which in turn corresponds to 85% probability of detection using Neyman-Pearson criterion. By testing the algorithm on several simulated and experimental images (which reflect relevant scenarios characterizing crowded places) it is observed that it can be beneficially implemented to introduce automation in the process of detecting moving subjects with fever.
25

Automatic Features Identification with Infrared Thermography in Fever Screening

Surabhi, Vijaykumar 12 January 2012 (has links)
The goal of this thesis is to develop an algorithm to process infrared images and achieve automatic identification of moving subjects with fever. The identification is based on two main features: the distinction between the geometry of a human face and other objects in the field of view of the camera, and the temperature of the radiating object. Infrared thermography is a remote sensing technique used to measure temperatures based on emitted infrared radiation. Applications include fever screening in major public places such as airports and hospitals. Current accepted practice of screening requires people to stay in a line and temperature measurements are carried out for one person at a time. However in the case of mass screening of moving people the accuracy of the measurements is still under investigation. An algorithm constituting of image processing to threshold objects based on the temperature, template matching and hypothesis testing is proposed to achieve automatic identification of fever subjects. The algorithm was first tested on training data to obtain a threshold value (used to discriminate between face and non face shapes) corresponding to a false detection rate of 5%, which in turn corresponds to 85% probability of detection using Neyman-Pearson criterion. By testing the algorithm on several simulated and experimental images (which reflect relevant scenarios characterizing crowded places) it is observed that it can be beneficially implemented to introduce automation in the process of detecting moving subjects with fever.
26

In-flight Receptivity Experiments on a 30-degree Swept-wing using Micron-sized Discrete Roughness Elements

Carpenter, Andrew L. 16 January 2010 (has links)
One of the last remaining challenges preventing the laminarization of sweptwings is the control of unstable crossflow vortices. In low-disturbance environments the transition from laminar to turbulent flow on the swept-wing initially takes the path of receptivity, where surface roughness or disturbances in the environment introduce shortwavelength disturbances into the boundary layer. This is followed by development and linear growth of stationary crossflow vortices that modify the mean flow, changing the stability characteristics of the boundary layer. Finally, breakdown to turbulence occurs over a short length scale due to the high-frequency secondary instability. The receptivity mechanism is the least understood, yet holds the most promise for providing a laminar flow control strategy. Results of a 3-year flight test program focused on receptivity measurements and laminar flow control on a 30-degree swept-wing are presented. A swept-wing test article was mounted on the port wing of a Cessna O-2A aircraft and operated at a chord Reynolds number of 6.5 to 7.5 million. Spanwise-periodic, micronsized discrete roughness elements were applied at the leading edge of the swept-wing in order to excite the most unstable crossflow wavelength and promote early boundary layer transition. An infrared camera was used to detect boundary-layer transition due to changes in leading-edge roughness. Combined with the IR camera, a new technique of calibrating surface-mounted hotfilms was developed for making disturbance-amplitude measurements downstream of modulated roughness heights. This technique proved to be effective at measuring disturbance amplitudes and can be applied in future tests where instrumentation is limited. Furthermore, laminar flow control was performed with subcritically-spaced roughness. A 100% increase in the region of laminar flow was achieved for some of the conditions tested here.
27

Soundness Assessment Of Historic Structural Timber By The Use Of Non-destructive Methods

Kandemir, Aysenur 01 March 2010 (has links) (PDF)
The use of non-destructive testing (NDT) methods was needed for the conservation studies of historic timber structures. The aim of this study was to develop combined use of ultrasonic pulse velocity (UPV) measurements and infrared (IR) thermography, together with visual analyses for soundness assessment of timber. An important timber structure in Ankara, Aslanhane Mosque and traditional timber dwellings, in AyaS and istiklal District were selected for in-situ analyses. Representative laboratory samples such as mud brick, fired brick, mud mortar, mud plaster, lime plaster, historic timbers of different species and some new timbers were used for analyses in the laboratory to develop reference data for in-situ analyses. This study has shown that direct and indirect UPV measurements taken parallel to fiber direction were good at estimating the soundness of timber elements. UPV measurements taken from timber samples were affected by atmospheric humidity, at which the timber was in equilibrium with or by its water content, cuts of timber and type of species. Quantitative Infrared thermography (QIRT) was good at soundness assessment and defect inspection of timber. The study showed that, the even or heterogeneous distribution of surface temperatures, different thermal inertia characteristics, reflected by the rates of heating and cooling of materials and their ratios to sound timber were good parameters to assess the state of deterioration of timber elements, dampness problems and the compatibility of neighbouring materials with timber. The joint use of QIRT and UPV methods combined with laboratory data has enhanced the accuracy and effectiveness of the survey.
28

Thin film coatings for new generation infrared thermal picture synthesising devices

Rodriguez, Jose Virgilio Anguita January 2001 (has links)
No description available.
29

Termografijos taikymo veterinarijoje analizė / Analysis of thermography application in veterinary medicine

Genys, Alfonsas 05 March 2014 (has links)
Pastaruoju metu Europos Sąjungoje ir kitose pasaulio valstybėse daug dėmesio skiriama gyvūnų sveikatos užtikrinimui ir naujų technologijų diegimui, susijusių su ligų prevencija. Siekiama tobulinti ir vykdyti ligų prevencijos ir kontrolės programas, ieškanti naujų modernių tyrimų metodų gyvūnų sveikatos būklei tirti.Daugelis patologinių pakitimų atsiranda dėl temperatūros pokyčių. Infraraudonųjų spindulių termografija (IRT) yra neinvazinis metodas matuojantis spinduliuojamos šilumos skleidimą iš odos, atspindintis medžiagų apykaitą (Jones, Plassmann, 2002). Šio metodo pagalba galima aptikti organizmo funkcinius sutrikimus, lūžių, sąnarių ir raiščių traumas, patempimus, uždegimo procesus, karščiavimą.Šiandien termografiniai tyrimai veterinarijos kryptyje Lietuvoje nevykdomi, jie vis plačiau naudojam medicinojoe įvairiose srityse ir net onkologijoje. Darbo tikslas- išanalizuoti, susisteminti ir ištirti infraraudonosios spinduliuotės (IFR) taikymo galimybes veterinarijoje bei atlikti karvių galūnių termografinius tyrimus. Darbo uždaviniai: 1. Išanalizuoti ir susisteminti termografijos taikymo galimybes veterinarijoje. 2. Nustatyti FLIR sistemos. THERMA CAM P640 taikymą karvių bandoje kojų būklei vertinti kartu naudojant ir šlubavimo taškų vertinimo sistemą. 3. Atlikti karvių galūnių ortopedinį tyrimą. Darbo metodika: darbas atliktas 2012 kovo– birželio mėnesiais tirta Lietuvos juodmargių populiacijos aukšto pieningumo karvių banda (n=97).Karvių priekinių ir užpakalinių kojų... [toliau žr. visą tekstą] / Recently, the European Union and other countries of the world has paid much attention to animal health security and the introduction of new technologies related to the prevention of disease. The aim is to improve and promote programs of the prevention and control of disease by searching for new modern research methods to examine the animal health condition. Many pathological changes are caused by temperature changes. Infrared thermography (IRT) is a non-invasive method of measuring the intensity of heat dissemination from the skin, reflecting metabolism (Jones, Plassmann, 2002). This method helps to detect functional disorders of the body, fractures, joint and ligament injuries, sprains, inflammation processes, and fever. Currently, thermographic research is not carried out in the field of veterinary in Lithuania, although they are widely applied in various fields of medicine and even cancer treatment. The aim of the research- to analyse, systematize and investigate the possibility to apply infrared rays (IR) in the field of veterinary medicine as well as to perform the thermal analysis of cows limbs. The tasks of the research: 1. To analyse and systematize the possibility to apply thermography in the field of veterinary medicine. 2. To determine the possibility to apply FLIR system THERMA CAM P640 in the assessment of the cow leg condition in a herd also using the assessment system of limping points. 3. To perform the orthopedic examination of the cow limbs. The research was... [to full text]
30

Automatic Features Identification with Infrared Thermography in Fever Screening

Surabhi, Vijaykumar 12 January 2012 (has links)
The goal of this thesis is to develop an algorithm to process infrared images and achieve automatic identification of moving subjects with fever. The identification is based on two main features: the distinction between the geometry of a human face and other objects in the field of view of the camera, and the temperature of the radiating object. Infrared thermography is a remote sensing technique used to measure temperatures based on emitted infrared radiation. Applications include fever screening in major public places such as airports and hospitals. Current accepted practice of screening requires people to stay in a line and temperature measurements are carried out for one person at a time. However in the case of mass screening of moving people the accuracy of the measurements is still under investigation. An algorithm constituting of image processing to threshold objects based on the temperature, template matching and hypothesis testing is proposed to achieve automatic identification of fever subjects. The algorithm was first tested on training data to obtain a threshold value (used to discriminate between face and non face shapes) corresponding to a false detection rate of 5%, which in turn corresponds to 85% probability of detection using Neyman-Pearson criterion. By testing the algorithm on several simulated and experimental images (which reflect relevant scenarios characterizing crowded places) it is observed that it can be beneficially implemented to introduce automation in the process of detecting moving subjects with fever.

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