Interstitial lung diseases are a heterogeneous group of disorders that vary widely in etiology, clinic-radiologic presentation, histopathologic features, and clinical course. MDCT is the modality of choice for determining the extent of diffuse interstitial lung disease and predicting the clinical outcomes as the scoring of fibrosis correlates well with the mortality rate. Different visual scoring systems for evaluating ILDs’ extent on HRCT have been developed over the past 20 years. Several visual scoring methods have been used to characterize and quantify the disease, correlate with common clinical parameters, prognosticate patients, assess disease progression and evaluate response to treatment. Up to date, visual scoring remains the method of choice for assessing disease extent in clinical practice. However, these methods show variable reproducibility in literature and therefore, a more accurate classification system is necessary for objective and reproducible assessment of disease extent. This has lead to considerable research efforts in advanced computer-based ILD extent quantification systems in the last 10 years. In this Thesis we compare four different available methods for the assessment of interstitial lung disease, for total, ground glass and reticular extent. A radiologist in training evaluated disease extent using a semi-quantitative visual scoring method (a), a visual pixel-based method (b) and semi-automated histogram thresholding technique (c). An automated CAD algorithm (d) was also utilized. All methods were applied to the same data sample of patients with collagen vascular diseases and lung involvement. The sample performance is reported on axial slice basis in terms of mean, standard deviation and range. Furthermore, methods have been compared pairwise by means of Bland-Altman analysis, utilized in order to assess by inspection the degree of agreement for varying disease extent. Additionally, the Intraclass Correlation Coefficient index has been calculated for all pairs compared. Statistical analysis showed almost perfect agreement between our visual pixel based method and the automated system concerning total and reticular disease extent, while the CAD algorithm and thresholding technique have demonstrated substantial agreement. None of the pairwise comparisons exhibited a high degree of agreement concerning ground glass extent estimation. Inter-observer comparison manifested significantly higher degree of agreement for the visual pixel based technique as compared to semi-quantitative visual scoring method. CAD algorithms provide a fast and reproducible disease extent and in our study present a high agreement with visual pixel based method, which is accounted for the more precise, albeit time wasting method. Resultantly, these automated systems could replace semi-quantitative visual scoring methods, not radiologists, in terms of accuracy, reproducibility and more precise clinical decision. / Οι διάμεσες πνευμονοπάθειες αποτελούν μια ετερογενή κατηγορία διαταραχών με ποικίλη αιτιολογία, κλινική, ιστολογική και ακτινολογική εικόνα. Η MDCT αποτελεί τη μέθοδο εκλογής για την εκτίμηση της έκτασης της νόσου και επομένως για την κλινική πορεία των ασθενών, εφόσον η έκταση της ίνωσης εμφανίζει υψηλή συσχέτιση με το δείκτη θνητότητας. Τα τελευταία 20 χρόνια έχουν αναπτυχθεί πολλά διαφορετικά συστήματα και μέθοδοι, που βασίζονται στην οπτική παρατήρηση και αποσκοπούν στον χαρακτηρισμό και την ποσοτικοποίηση της έκτασης της διάμεσης νόσου, καθώς και στο συσχετισμό της με κλινικές παραμέτρους, όπως η πρόγνωση και η ανταπόκριση στη θεραπεία. Οι ημιποσοτικές μέθοδοι, που βασίζονται στην οπτική παρατήρηση παραμένουν έως και σήμερα μέθοδοι εκλογής για την αξιολόγηση και ποσοτικοποίηση της έκτασης της νόσου. Εντούτοις, χαρακτηρίζονται σύμφωνα με τα βιβλιογραφικά δεδομένα από χαμηλούς δείκτες επαναληψιμότητας. Ως εκ τούτου, η αναζήτηση περισσότερο αντικειμενικών και επαναλήψιμων μεθόδων για την εκτίμηση της διάμεσης πνευμονοπάθειας είναι επιτακτική ανάγκη. Ως αποτέλεσμα, τα τελευταία 10 χρόνια η ερευνητική προσπάθεια έχει προσανατολιστεί σε αυτοματοποιημένες μεθόδους για την ποσοτικοποίηση της διάμεσης νόσου. Στην παρούσα διπλωματική συγκρίθηκαν τέσσερεις διαφορετικές μέθοδοι, διαθέσιμες για την ποσοτικοποίηση των αλλοιώσεων του πνευμονικού ιστού. Η έκταση της νόσου αξιολογήθηκε από έναν ειδικευόμενο ακτινολόγο με ημιποσοτική μέθοδο με οπτική παρατήρηση (α), με ποσοτική μέθοδο χειρονακτικού σχεδιασμού και τμηματοποίησης των προσβεβλημένων περιοχών (β) και με μια ημι-αυτόματη μέθοδο κατωφλίωσης ιστογράμματος (γ). Για τον ίδιο σκοπό χρησιμοποιήθηκε ένας αλγόριθμος υποβοήθησης διάγνωσης (CAD) (δ). Όλες οι μέθοδοι εφαρμόστηκαν στο ίδιο δείγμα δεδομένων από ασθενείς με νοσήματα του συνδετικού ιστού και πνευμονική προσβολή. Τα ημιποσοτικά αποτελέσματα, καθώς και αυτά της χειρωνακτικής τμηματοποίησης συγκρίθηκαν με τα αντίστοιχα δύο έμπειρων ακτινολόγων in consensus και μελετήθηκε η συμφωνία τους. Οι αποδόσεις των μεθόδων που χρησιμοποιήθηκαν στην εκτίμηση τόσο της συνολικής έκτασης της νόσου, όσο και των επιμέρους προτύπων συγκρίθηκαν ανά ζεύγη με ανάλυση κατά Bland-Altman και με υπολογισμό του δείκτη ICC (Intraclass Correlation Coefficient). Η στατιστική ανάλυση των αποτελεσμάτων έδειξε σημαντική συσχέτιση μεταξύ του CAD και του χειρωνακτικού σχεδιασμού για τη συνολική έκταση και το reticular πρότυπο, ενώ χαμηλότερη είναι η συμφωνία μεταξύ του CAD και της μεθόδου κατωφλίωσης ιστογράμματος. Δεν παρατηρήθηκε υψηλός δείκτης συμφωνίας σε κανένα ζεύγος συσχέτισης όσο αφορά την εκτίμηση του προτύπου θαμβής υάλου. Η συμφωνία των ακτινολόγων είναι υψηλότερη για την οπτική μέθοδο αξιολόγησης με χειρονακτική τμηματοποίηση σε σχέση με την ημιποσοτική μέθοδο με οπτική παρατήρηση. Οι αλγόριθμοι υποβοήθησης διάγνωσης παρέχουν γρήγορη και επαναλήψιμη εκτίμηση της έκτασης της διάμεσης νόσου και στη δικιά μας μελέτη παρουσιάζουν υψηλού βαθμού συσχέτιση με την ποσοτική μέθοδο, η οποία θεωρείται η πιο ακριβής, εντούτοις χρονοβόρα μέθοδος. Συμπερασματικά, τα αυτόματα αυτά συστήματα θα μπορούσαν να αντικαταστήσουν τις υποκειμενικές ημιποσοτικές μεθόδους στην ποσοτικοποίηση των διάμεσων αλλοιώσεων του πνεύμονα.

The overall aim of the project is to examine the rivetability of new steels and to investigate the mechanical behaviour of self-piercing riveted (SPR) aluminium-steel hybrid structures for automotive applications. Interstitial Free Steel (I.F.) of 1.2 mm thickness was joined to Aluminium 5754 of 2 mm thickness and Aluminium 5182 (coated and uncoated) of 1.5 mm thickness. The work began by initially conducting a quality assessment of the various joints that were produced in order to establish the optimum conditions for joining the various sample combinations to be investigated. A relationship was established between the head height and the interlock distance on the one hand and between the interlock distance and the lap shear strength of samples. It was also established that for higher lap shear strength, it is preferable to use the stronger material (I.F. steel) as the pierced sheet and the weaker material (5182) as the locked sheet. However, the results showed that this rule could not be applied for predicting the fatigue behaviour of SPR joints between I.F. steel and 5182. An investigation of the fatigue failure mechanisms was undertaken and possible reasons for this behaviour are discussed. The influence of fretting was also investigated by using scanning electron microscopy and reported. The fatigue behaviour of Dual Phase (DP600 + 5182) SPR joints was investigated. It was observed that the position of fatigue crack initiation differed with the maximum applied load. An explanation for this observation was provided by considering the failure mechanism of the samples under different load levels. The study also showed how fretting led to the initiation of fatigue cracks. The corrosion behaviour of (I.F. steel + 5182) samples was investigated by conducting tests in a salt spray according to the ASTM B117-97 standard. Three types of corrosion were observed; galvanic corrosion, differential aeration corrosion, uniform corrosion and are discussed. The weight change with time was monitored and was used to describe the corrosion behaviour. The lap shear strength was measured as a function of corrosion time. The presence of the corrosion product within the overlap was observed to greatly influence the lap shear strength behaviour. A further study was carried out in order to examine the influence of the individual alloys on the corrosion of the SPR samples. In this part the potential influence of pulse current treatment on corrosion was also investigated and was observed to increase greatly the corrosion resistance of the I.F. steel. Principal findings for this observation are also provided.

Myxomatous mitral valve degeneration (MMVD) is the single most common cardiac disease of the dog, and is analogous to Mitral Valve Prolapse in humans. Very little is known about the aetiopathogenesis of this disease or the changes in valvular interstitial cell populations in diseased valves. The aim of this study was to identify morphological, cellular and molecular changes associated with MMVD. Mitral valve leaflets from both normal and varying grades (Whitney’s 1-4) of diseased dogs were subject to image analysis, immunophenotyping, proteomics and RT-PCR. Image analysis - leaflet thickening due to accumulation of glycosaminoglycan was significant in this disease. MMVD is associated with loss of connective tissue, reduction in cell numbers but no change in cell shape in the overtly myxomatous area. Near the surface, increase in valvular interstitial cells (VIC) towards the damaged endothelium in concert with destruction of collagen and building up of ground substance was manifested during the disease process. Immunophenotyping - activated myofibroblasts were increased and fibroblast-like VICs were reduced without any change in desmin and myosin expression in MMVD compared to clinical normal dogs. In addition, other cell types like macrophage, adipocyte, chondrocyte, mast cell, and stem cell were identified and their possible role in MMVD is discussed. Proteomics - a protein expression profile was established, with 64 proteins being positively identified from dog’s mitral valve using 1-D SDS PAGE LC/MS. Amongst them 44 proteins were differentially expressed comparing normal and severely diseased. Two actin binding proteins, tropomyosin alpha and myosin light chain-2 were found to be differentially expressed in the normal but down regulated in the diseased. RT-PCR was used to assess the expression of 8 genes of interest. Their expression was compared with 3 different housekeeping genes.

Morphological conservatism combined with intraspecific variability has obstructed studies of speciation and species boundaries among marine meiofauna. Ototyphlonemertes is a genus of meiofaunal nemerteans inhabiting the interstitial spaces of marine sediments. Its members lack pelagic larvae and dispersal potential is believed to be poor. A phylogeographic study of Ototyphlonemertes fila is presented using mitochondrial (cox3) and nuclear (ISSR) molecular markers. Deep genetic divergence (approximately 18% in cox3) was observed between sympatric mitochondrial lineages in Florida. This divergence was reflected in the nuclear marker as well, suggesting the presence of two cryptic species. The first contains Florida and New England populations separated by 3% cox3 sequence divergence and showing no evidence of ongoing gene flow. The second contains two codistributed mitochondria1 clades in Florida separated by 3% cox3 sequence divergence and showing exchange of nuclear alleles. Surprisingly, relatively little fine-scale structuring was found, suggesting that passive dispersal is significant over moderate geographical distances.

A demanda da indústria automobilística por aços de boa estampabilidade, para aplicação em peças expostas motivou o desenvolvimento de várias especificações de aços livres de intersticiais (IF) na Companhia Siderúrgica Nacional. A especificação de aço \"IFTi\", pertencente ao grupo de aços para estampagem extra profunda especial (CSN EEPIF), com limite de resistência < 380 MPa está, dentre todos os graus de aço processados nas linhas de laminação a frio, entre os que apresentam a maior porcentagem de desvio por marca de rebarba e outros problemas relacionados ao corte. A geração de uma rebarba com altura excessiva está relacionada a um corte de má qualidade. Durante o processo de laminação a frio essa rebarba pode aumentar ainda mais de tamanho, se desprender, marcar os cilindros de trabalho e conseqüentemente aumentar os custos de produção por desvios e troca precoce de cilindros. Nas linhas de decapagem, a tesoura de pontas final é o equipamento responsável por separar as bobinas soldadas no início do processo e definir a característica de corte das pontas e caudas das mesmas, através de corte por guilhotinamento. Visando aumentar a qualidade, produtividade, diminuir as perdas durante o processo e atender às exigências dos clientes internos e externos, foi necessário desenvolver o processo de corte por guilhotina do aço IF nas tesouras de pontas final das Linhas de Decapagem Contínua 3 e 4 da CSN. Através da simulação de corte em laboratório, usando-se a mesma velocidade de avanço e ângulo de inclinação do equipamento de campo, avaliou-se a relação entre o ajuste de folga entre navalhas e o comportamento força x deslocamento no cisalhamento. Além disso, através da análise por microscopia eletrônica de varredura (MEV) foi possível observar o efeito dos varios ajustes de folga na superfície de fratura, identificando as regiões de corte citadas na literatura e sua relação com as características microestruturais e com as propriedades do material. Constatou-se que a tensão cisalhante durante o corte diminuía a medida em que a folga aumentava de forma linear para uma faixa de folga ajustada entre 6 e 12%t em amostras de aço IF-Ti com 1,5mm de espessura. Nas micrografias feitas em MEV, observou-se que as interfaces entre penetração e fratura ficaram irregulares em todos os casos, sendo uma região intermediária, com aspecto misto entre as regiões de penetração e fratura foi relacionado ao desencontro das frentes de trincas principalmente devido ao grande ângulo de fratura. Tanto os perfis de corte quanto as superfícies de fratura mostraram que a fração da região de corte diminuía com o aumento da folga, até certo ponto, quando a partir da mudança do comportamento da tensão cisalhante, voltava a aumentar. Pode-se verificar também, que a fração da região de deformação aumentava à medida que folgas maiores eram testadas e os valores atingidos eram muito superiores as deformações esperadas para as respectivas características do tipo de corte indicado pelas regiões de penetração e fratura. Os melhores resultados de corte foram obtidos na regulagem de folga entre 4 e 8%t, com rebarbas inferiores a 1,5%t, menores frações da região de deformação e interface corte/fratura mais regulares do que nas demais faixas de folga. / The automotive industry\'s demand for high formability steels for use in exposed body panels motivated the development of several interstitial free (IF) steels specifications at Companhia Siderurgica Nacional. The \"IF-Ti\" steel specification belongs to the special deep drawing steels group (CSN EEP-IF), with yield strength <380 MPa, and among all grades of steel processed in the cold rolling lines is the one with the highest amount of deviation by burr marks and other problems related to shearing. The generation of an excessive burr height is related to a poor cut quality. During the cold rolling process the burr can increase in size, break off, mark the work rolls and therefore increase production costs per deviation and early exchange of cylinders. In the pickling lines, the exit shear is the device responsible for separating the coils welded at the beginning of the process and to define the cutting head and tail characteristics, either through guillotine cutting. Aiming to increase quality, productivity, reduce losses during the process and meet the requirements of internal and external customers, it was necessary to develop the guillotine cutting process of the IF steel sheet extremities (head and tail) in the exit shears of Continuous Pickling Lines #3 and #4 at CSN. Through the cutting simulation in the laboratory, using the same forward speed and rake angle adopted in the field equipment, was evaluated the relationship between the adjustment of clearance between blades and the behavior shear force versus displacement. In addition, through the analysis by scanning electron microscopy (SEM) it was possible to observe the effect of several settings on the fracture surface, identifying the different regions cited in the literature and its relation to the microstructural characteristics and to the material properties. It was found that the shear stress during cutting reduced as the gap increased linearly to a range between 6 and 12%t in samples of IF-Ti steel with 1.5 mm thick. In the micrographs taken by SEM, it was observed that the interfaces between burnished and fracture were irregular in all cases, where an intermediate depth, with mixed aspect between the burnished and fracture depths was related to mismatch of crack fronts mainly due to the large fracture angle. Both cut profiles as the fracture surfaces showed that the burnished depth decreased with increasing the gap to some extent, since from the behavior change of shear stress, it started to increase. It was also possible to verify that the fraction of therollover depth increased as larger gaps were tested and the values achieved were much higher than expected for the rollover characteristics of the respective type of cut indicated by the burnished and fracture depths. The best cutting results were obtained for clearance adjustment between 4 and 8%, resulting in burrs below 1.5%t, smaller rollover depth and more regular burnished/fracture interface than in other clearance ranges tested.

A conquista do ambiente terrestre por caranguejos Brachyura é dependente da obtenção e reserva de água na câmara branquial durante o período de emersão. Uma maneira de se obter água do meio é através de tufos de cerdas hidrofílicas, capazes de captar água do solo por capilaridade. Sabe-se que essas cerdas hidrofílicas estão associadas à abertura de Müller e que a água captada é admitida na câmara branquial graças à diferença de pressão entre a câmara branquial e o meio externo, produzida pelos batimentos do escafognatito. Contudo, as modificações morfológicas esqueletais e apendiculares para a formação da abertura de Müller e a composição das cerdas do tufo não são conhecidos. Com o intuito de elucidar tais lacunas, foram estudados o esqueleto axial, apendicular e a quetotaxia de 22 espécies de caranguejos semiterrestres pertencentes às superfamílias Grapsoidea (Grapsidae, Sesarmidae, Varunidae e Gecarcinidae) e Ocypoidea (Ocypodidae e Ucididae). O estudo do esqueleto axial e apendicular revelou que a abertura de Müller é, na verdade, um canal complexo que pode ser composto por três componentes: o canal pleural, a calha apendicular e o tufo de cerdas. A água presente no substrato é captada pelo tufo de cerdas, é conduzida pela calha apendicular, passa pelo canal pleural para, enfim, ser admitida na câmara branquial. O tufo de cerdas é formado entre a face posterior do coxopodito do pereópode 3 e a face anterior do coxopodito do pereópode 4. Em Sesarmidae, o tufo também ocorre entre os coxopoditos dos pereópodes 2 e 3. Os representantes das superfamílias Grapsoidea e Ocypodoidea diferem quanto à formação do canal de Müller. Os tipos de cerdas presentes nos tufos de cerda associados ao canal de Müller são os mesmos encontrados em outros pereópodes e no bordo da região branquiostegal (cerdas simples, paposas e papo-serradas). A única exceção são as cerdas constritas presentes, exclusivamente, nos tufos de cerdas das espécies da família Ocypodidae. Nos tufos de Grapsoidea, a inserção de cerdas no coxopodito do pereópode 4 ocorre somente na sua porção ventral enquanto, em Ocypodoidea, as cerdas do coxopodito do pereópode 4 se inserem tanto na porção ventral como na porção distal. A calha apendicular pode ser formada entre as coxas dos pereópodes 5/6 ou 6/7, de formato cilíndrico ou semicilíndrico. A função da calha apendicular está associada com a condução da água entre o tufo de cerdas e o canal pleural, embora existam casos de formação do canal de Müller sem a presença da calha apendicular. O canal pleural pode ser aberto ou semitubular, ocorrendo, sempre, entre os pleuritos torácicos 6 e 7 e, em algumas espécies, também entre os pleuritos torácicos 5 e 6. O canal pleural aberto é formado pelo afastamento de dois pleuritos torácicos adjacentes; o canal semitubular é formado pela projeção do pleurito 7 sobre o pleurito torácico 6. Foram encontrados, pelo menos, sete padrões de organização do canal de Müller que variam entre a ausência completa da estrutura até a formação de um canal completo (que apresente tufo de cerdas, calha apendicular e canal pleural, concomitantemente). Ucides cordatus (Ucididae) apresentou modificações esqueletais singulares, bastante diferentes dos demais Ocypodoidea e também de Grapsoidea. As espécies que apresentam maior nível de terrestrialidade (família Gecarcinidae) foram as únicas que não apresentaram canal de Müller ou qualquer adaptação para captação de água do substrato. / The conquest of terrestrial environment by brachyuran crabs depends on the attainment and maintainability of water in the branchial chamber during the emersion period. One way to get environmental water is through tufts of hydrophilic setae, capable of picking up water from the soil by capillarity. It is known that these hydrophilic setae are attached to the Müllers opening and the collected water is admitted into the branchial chamber due to the pressure difference between the branchial chamber and the external environment, produced by the scaphognathite beating. However, the morphological modifications of the axial and appendicular skeleton to form the Müllers opening and the composition of the seta tuft are not known. In order to elucidate such gaps, the axial skeleton, the appendicular skeleton and the chaetotaxy of 22 species of semiterrestrial crabs belonging to superfamilies Grapsoidea (Grapsidae, Sesarmidae, Varunidae and Gecarcinidae) and Ocypodoidea (Ocypodidae and Ucididae) were studied. The study of the axial and appendicular skeleton revealed that the Müllers opening is actually a complex channel that may be comprised of three components: the pleural channel, the appendicular gutter and the setal tuft. The water is collected from the substrate by the setal tuft and carried through the appendicular gutter. Then it passes through the pleural channel to be finally admitted into the branchial chamber. The setal tuft is formed between the posterior face of the coxopodite of pereopod 3 and the anterior face of the coxopodite of pereopod 4. In Sesarmidae species, a second tuft also occurs between the coxopodites of pereopods 2 and 3. Representatives of the superfamilies Grapsoidea and Ocypoidea differ in the formation of Müllers channel. In Grapsoidea tuft, the setal insertion occurs only in the ventral portion of coxopodite of pereopod 4 while in Ocypodoidea, the insertion of these seta occurs both in the ventral and distal portions of coxopodite of pereopod 4. The types of seta which are present in setal tufts associated with the Müllers channel are the same found in other pereopods and in the edge of branchiostegal region (simple, paposes and paposerrate seta). The only exception is the constricted seta which is present exclusively in the setal tufts of Ocypodidae species. The appendicular gutter may be formed between the coxopodites of the 5/6 or 6/7 pereopods, in cylindrical or semi-cylindrical shape. The function of the appendicular gutter is associated with the water conduction between the setal tuft and the pleural channel, although there are cases in which the formation of Müllers channel happens without the presence of the appendicular gutter. Pleural channel can be opened or semitubular. They always occur between thoracic pleurites 6/7 and, in some species, between the thoracic pleurites 5 and 6 as well. The open pleural channel is formed by the spacing of two adjacent thoracic pleurites; the semitubular pleural channel is formed by the projection of pleurite 7 above pleurite 6. At least seven patterns of organization of the Müllers channel were found, ranging from the complete absence of the structure to the formation of a full channel (presenting setal tuft, appendicular gutter and pleural channel concurrently). Ucides cordatus (Ucididae) showed quite unique skeletal modifications, different from the others Ocypodoidea and also from the Grapsoidea. The species with the highest level of terrestriality (Gecarcinidae family) were the only ones who did not have Müllers channel or any adaptation to water abstraction from the substrate.

As propriedades mecânicas de metais com estrutura cristalina cúbica de corpo centrado (CCC), tais como nióbio e suas ligas, são alteradas de forma bastante significativa com a adição de elementos intersticiais pesados. Estes elementos intersticiais (oxigênio, nitrogênio e carbono) presentes na matriz metálica ocupam sítios octaedrais e constituem um dipolo elástico de simetria tetragonal, podendo produzir relaxações anelásticas. As amostras utilizadas foram policristais da liga Nb-Ti, contendo 0,3% em peso de Ti. As medidas de espectroscopia anelástica foram efetuadas usando um pêndulo de torção invertido, operando com freqüência da ordem de hertz, em um intervalo de temperatura entre 300 e 700 K, com taxa de aquecimento de 1 K/min. Esta dissertação apresenta estruturas de relaxação termicamente ativadas observadas em amostras da liga Nb - 0,3%pTi, contendo diferentes concentrações de oxigênio em solução sólida. Estas estruturas de relaxação foram atribuídas à reorientação induzida por tensão de átomos intersticiais em tomo de átomos da matriz metálica. Tais estruturas foram analisadas e foram encontrados os seguintes processos de relaxação: Nb-O, Ti-O, Nb-N e Nb-C. Os resultados mostraram também uma relação direta entre as intensidades das estruturas de relaxação e a concentração dos elementos intersticiais presentes nas amostras. / The mechanical properties of metals with body centered cubic (BCC) crystalline structure such as Nb and its alloys are modified of sufficiently significant form with the addition of heavy interstitial elements. These interstitial elements (oxygen, for example) present in the metallic matrix occupy octahedral sites and constitute an elastic dipole of tetragonal symmetry, being able to produce an elastic relaxation. The used samples were polycrystals of the Nb-Ti alloy, having 0.3 % in weight of Ti. The an elastic spectroscopy measurements were taken using an inverted torsion pendulum, operating with frequency of the order of hertz, in a temperature range between 300 and 700 K, with heating rate of 1 K/min. This dissertation shows thermally activated relaxation structures observed in samples of the Nb - 0.3wt.%Ti alloy, having different concentrations of oxygen in solid solution. These relaxation structures were attributed to stress induced ordering of interstitial atoms around the metallic matrix atoms. Such structures were analyzed and were found the following relaxation processes: Nb-O, Ti-O, Nb-N and Nb-C. The results had also shown a direct relation between the intensities of the relaxation structures and the concentration of interstitial elements in the samples.

Os aços livres de intersticiais (IF) têm sido usados em todo o mundo de um modo crescente desde a década de 70. A grande aplicação deste tipo de aço é na indústria automobilística em função de sua excelente conformabilidade, aliada à característica de não envelhecimento. Estas características facilitam a produção e permitem o desenvolvimento de novos projetos. Na década de 90, a Companhia Siderúrgica Nacional (CSN) iniciou a produção em escala de materiais macios, como os aços IF através do desgaseificador à vácuo RH. Procurando aumentar a participação no mercado automotivo, foi necessário desenvolver o processo de aparamento lateral do aço IF nas Linhas de Decapagem Contínua 3 e 4 da CSN para atender a demanda dos clientes. Neste trabalho, foram identificadas variáveis que influenciam a qualidade da borda aparada lateralmente das chapas laminadas a quente e a frio, as quais estão sendo testadas e ajustadas: (1) Material do aço IF, (2) parâmetros de aparamento lateral, (3) qualidade da navalha circular de aço ferramenta e sua lubrificação,(4) velocidade da navalha circular, (5)uso ou não do push-up-roll, um equipamento auxiliar para o aparamento da borda da chapa de aço. O principal objetivo do trabalho aqui apresentado é encontrar as condições que impeçam a formação de rebarba na borda do aço IF laminado a quente e decapado após aparado lateralmente nas Linhas de Decapagem Contínua 3 e 4 da CSN. As características da apara lateral foram avaliadas por microscopia eletrônica de varredura. Análises microestruturais, bem como ensaios de tração também foram executadas em amostras coletadas nas chapas laminadas a quente e a frio para vários parâmetros definidos de aparamento lateral. / The Interstitial Free (IF) steels have been used all over the world in an increasing way since the 70 decade\'s. The great application of this type of steel is in the automobile industry in function of your excellent formability, allied to the non aging property. These characteristics facilitate the production and allow the development of new projects. In this work, it has been identified variables that influence the quality of side trimming edge of hot and cold rolled strip, which were tested and adjusted: (1) IF steel material, (2) side trimming parameters,(3) tool steel circular knife quality and your lubrication;(4) tool steel speed, (5)use or not of pushup-roll , an auxiliary equipment to the cutting edge. The main objective of the work here presented it is to find the operation conditions that impede the burr formation in the edge of hot and pickled IF steel after side trimmed in the Continuous Pickling Lines 3 and 4 at CSN. The side trimmed characteristics were assessed by scanning electron microscopy. microstructural analyses, as well as tensile tests were also performed in samples taken from the hot and cold-rolled strip for the various adopted side trimming parameters.

Pneumonia intersticial familiar (PIF) é definida como a ocorrência de pelo menos dois casos de pneumonia intersticial fibrosante em uma mesma família biológica. Apesar do avanço sobre o tema em anos recentes, ainda não há estudos brasileiros nessa área. O objetivo deste estudo foi caracterizar uma amostra de pacientes brasileiros com PIF quanto aos aspectos clínicos, radiológicos, anatomopatológicos e genéticos, bem como analisar os respectivos comprimentos teloméricos (CT). Entre março de 2014 e novembro de 2017 foi realizada uma busca ativa por casos de PIF. Os pacientes identificados foram submetidos a testes de função pulmonar; tomografia computadorizada de alta resolução (TCAR) de tórax e a coleta de amostras de sangue. Ainda foram realizadas avaliações empregando ficha clínica padronizada. Amostras de tecido pulmonar foram obtidas e revisadas em seis casos. Empregando-se um kit apropriado, DNA genômico foi extraído de células brancas do sangue periférico. A avaliação do CT foi feita pelo método de Southern blot. Um painel envolvendo 154 genes de interesse foi desenvolvido pelo grupo de pesquisa e construído pela empresa Agilent Technologies. A pesquisa desses genes foi realizada empregando-se técnicas de sequenciamento de nova geração (NGS-Illumina). Foram selecionados 35 pacientes, com idade mediana de 66 (35,5-89,3) anos. Tabagismo e outras exposições ambientais estiveram presentes em 45,7% e 80% dos casos, respectivamente. Estertores finos foram identificados em 91,4% dos pacientes e baqueteamento digital em 20%. Os testes de função pulmonar foram classificados como restritivos em 20 (57,1%), normais em 10 (28,6%), inespecíficos em 4 (11,45) e obstrutivo leve em 1 (2,9%). A DCO esteve reduzida nos 30 pacientes em que foi possível pesquisá-la. Padrão típico de PIU na TCAR foi detectado em 6 (17,1%) pacientes e padrão indeterminado para PIU em outros 4 (11,4%). A maioria dos casos, 25 (71,4%), exibiu padrão tomográficoinconsistente com PIU. A revisão do material anatomopatológico revelou pneumonite intersticial com acentuação bronquiolocêntrica em quatro indivíduos. A grande maioria (85,7%) mostrou CTs inferiores ao percentil 50%. Quatro indivíduos exibiram CTs curtos e um muito curto. Foram identificadas variantes genéticas comuns no promotor do gene MUC5B (rs35705950), nos genes TOLLIP (rs111521887, rs5743894 e rs5743890) ou TERT (rs2736100) em 90% dos casos. Detectaram-se ainda sete variantes raras distintas. As alterações c.2594G>A e c.2146G>A do gene TERT, e c.394C>T do gene RTEL1, previamente descritas e associadas a telomeropatias. Uma anormalidade de TERT (c.1730G>A) e outra de RTEL1 (c.2299C>T) inéditas. Duas outras variantes raras encontradas já conhecidas, ainda não haviam sido associadas a doenças pulmonares: gene SHQ1 (c.828_831del) e gene WRAP53 (c.1558dupG). Em conclusão, pacientes brasileiros com PIF demonstram acentuada heterogeneidade fenotípica e genotípica. Este estudo identificou ainda duas novas variantes genéticas raras associadas a PIF e dois possíveis novos genes implicados na patogênese dessa doença. / Familial interstitial pneumonia (FIP) is defined as the occurrence of at least two cases of interstitial fibrosing pneumonias in the same biological family. Despite advances in the field in recent years, there are no Brazilian studies in this area. The aim of this study was to characterize a sample of Brazilian patients with PIF regarding clinical, radiological, histological and genetic aspects, as well as to analyze the respective telomeric lengths (TL). Between March 2014 and November 2017 an active search was conducted for FIP cases. The patients identified were submitted to pulmonary function tests, high resolution computed tomography (HRCT) of the chest and the collection of blood samples. In addition, a standardized clinical file was also fulfilled. Pulmonary tissue samples were obtained and reviewed in six cases. Using a suitable kit, genomic DNA was extracted from white peripheral blood cells. The TL measurements were done by Southern blot method. A panel of 154 genes of interest was developed by the research group and built by Agilent Technologies. Research on these genes was carried out using next generation sequencing techniques (NGSIllumina). Thirty-five patients were selected, with a median age of 66 (35.5-89.3) years. Smoking and other environmental exposures were present in, respectively, 45.7% and 80% of the cases. Fine crackles were identified in 91.4% of patients and digital clubbing in 20%. Pulmonary function tests were classified as restrictive in 20 (57.1%), normal in 10 (28.6%), non-specific in 4 (11.45) and mild obstructive in 1 (2.9%). The DLCO was reduced in the 30 patients in whom it was possible to investigate it. Typical pattern of UIP in HRCT was detected in 6 (17.1%) patients and undetermined pattern for UIP in another 4 (11.4%). The majority of cases, 25 (71.4%), showed a tomographic pattern inconsistent with UIP. The review of histological material revealed interstitial pneumonitis with bronchiolocentric accentuation in four individuals. The vast majority (85.7%) showed TL lower than the 50th percentile. Four individuals had short TL and one a very short TL. Commongenetic variants were identified in the MUC5B gene promoter (rs35705950), in the TOLLIP genes (rs111521887, rs5743894 and rs5743890) or TERT (rs2736100) in 90% of the cases. Seven different rare variants were also detected: the changes c.2594G> A and c.2146G> A of the TERT gene, and c.394C> T of the RTEL1 gene, previously described and associated with telomeropathy; one previously unknown abnormality of TERT (c.1730G> A) and another of RTEL1 (c.2299C> T); two additional rare genetic variants, had not yet been associated with pulmonary diseases: SHQ1 gene (c.828_831del) and WRAP53 gene (c.1558dupG). In conclusion, FIP Brazilian patients demonstrate marked phenotypic and genotypic heterogeneity. This study also identified two new rare genetic variants associated with FIP and two other possible new genes implicated in the pathogenesis of this disease.

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