O ensino religioso na escola pública: regras que cooperam para sua organização

Pós-graduação em Educação - FCT

Características e fatores associados às quedas atendidas em serviços de emergência

OBJETIVO: Analisar as características dos atendimentos decorrentes de quedas em serviços de urgência e emergência e identificar fatores associados. MÉTODOS: Estudo transversal com 12.617 atendimentos decorrentes de quedas registrados no Sistema de Vigilância de Violências e Acidentes, coletados em 23 capitais e Distrito Federal, de setembro a novembro de 2009, por meio de uma amostra por conglomerado. Foi utilizada a técnica de análise de correspondência, por permitir a observação conjunta de um grande número de variáveis qualitativas. RESULTADOS: A maior parte das vítimas foi do sexo masculino (56,5%), faixa etária de 0 a 19 anos (45,7%) e declarados não brancos (62,2%). A maioria das quedas ocorreu na residência (54,6%) e via pública (17,4%); 14,3% foram relacionadas ao trabalho. Os tipos predominantes foram "queda no mesmo nível" (57,0%) e "queda de escada/degrau" (15,6%). A maioria das lesões foi classificada como entorse, luxação, contusão, corte e laceração (68,3%). Quedas dentre as crianças associaram-se à ocorrência na residência; com os adolescentes na escola; e jovens na prática esportiva. Quedas em adultos estiveram associadas ao local de trabalho, queda de andaimes, telhados, escada/degrau e buracos e uso de álcool. As quedas no mesmo nível resultaram em lesões de menor gravidade, em membros inferiores e superiores, e as quedas de andaime e telhado se associaram com lesões de maior gravidade e internações. CONCLUSÕES: Os resultados mostram que estratégias para a prevenção das quedas devem ser implantadas particularmente em residências, escolas e ambientes de trabalho.

Magnetic Barkhausen Noise in Quenched Carburized Nickel-Steels

Two steel sheets, one with 5% Ni and another with 10% Ni, were submitted to carburization and quenching, obtaining a microstructure with martensite and retained austenite. These steels were characterized with magnetic Barkhausen noise (MBN). The Barkhausen signal is distinctively different for the carburized and quenched samples. The carburized and quenched samples present higher coercive field than the annealed samples. X-ray diffraction data indicated that the carburized and quenched samples have high density of dislocations, a consequence of the martensitic transformation.

Superconductivity at 9.5 K in the Ti2GeC compound

We report on the investigation of the Ti2GeC properties by X-ray diffraction, magnetic and electrical resistivity measurements. Polycrystalline samples of Ti2GeC with nominal compositions were prepared by solid state reaction. X-ray powder patterns suggest that all peaks can be indexed with the hexagonal phase of Cr2AlC prototype. The temperature dependence of both electrical resistivity and magnetization indicate a bulk type-II superconductivity at 9.5 K. Magnetoresistive data suggest an upper critical field of B-c2 similar to 8.1 T and coherence length similar to 61 A degrees . Furthermore, the results highlight the highest critical temperature reported up to now for an H-phase.

Polymer controlled mineralization of zinc phosphate hydrates and applications in corrosion protection, catalysis and biomedicine

ZUSAMMENFASSUNG Die Tauglichkeit von Hybridmaterialien auf der Basis von Zinkphosphathydrat-Zementen zum Einsatz als korrosionshemmende anorganische Pigmente oder zur prothetischen und konservierenden Knochen- und Zahntherapie wird weltweit empirisch seit den neunziger Jahren intensiv erforscht. In der vorliegenden Arbeit wurden zuerst Referenzproben, d.h. alpha-und beta-Hopeite (Abk. a-,b-ZPT) dank eines hydrothermalen Kristallisationsverfahrens in wässerigem Milieu bei 20°C und 90°C hergestellt. Die Kristallstruktur beider Polymorphe des Zinkphosphattetrahydrats Zn3(PO4)2  4 H2O wurde komplett bestimmt. Einkristall-strukturanalyse zeigt, daß der Hauptunterschied zwischen der alpha-und beta-Form des Zinkphosphattetrahydrats in zwei verschiedenen Anordnungen der Wasserstoffbrücken liegt. Die entsprechenden drei- und zweidimensionalen Anordnungen der Wasserstoffbrücken der a-und b-ZPT induzieren jeweils unterschiedliches thermisches Verhalten beim Aufwärmen. Während die alpha-Form ihr Kristallwasser in zwei definierten Stufen verliert, erzeugt die beta-Form instabile Dehydratationsprodukt. Dieses entspricht zwei unabhängigen, aber nebeneinander ablaufenden Dehydratationsmechanismen: (i) bei niedrigen Heizraten einen zweidimensionalen Johnson-Mehl-Avrami (JMA) Mechanismus auf der (011) Ebene, der einerseits bevorzugt an Kristallkanten stattfindet und anderseits von existierenden Kristalldefekten auf Oberflächen gesteuert wird; (ii) bei hohen Heizraten einem zweidimensionalen Diffusionsmechanismus (D2), der zuerst auf der (101) Ebene und dann auf der (110) Ebene erfolgt. Durch die Betrachtung der ZPT Dehydratation als irreversibele heterogene Festkörperstufenreaktion wurde dank eines „ähnlichen Endprodukt“-Protokolls das Dehydratationsphasendiagramm aufgestellt. Es beschreibt die möglichen Zusammenhänge zwischen den verschiedenen Hydratationszuständen und weist auf die Existenz eines Übergangszustandes um 170°C (d.h. Reaktion b-ZPT  a-ZPT) hin. Daneben wurde auch ein gezieltes chemisches Ätzverfahren mit verdünnten H3PO4- und NH3 Lösungen angewendet, um die ersten Stufe des Herauslösens von Zinkphosphat genau zu untersuchen. Allerdings zeigen alpha- und beta-Hopeite charakteristische hexagonale und kubische Ätzgruben, die sich unter kristallographischer Kontrolle verbreitern. Eine zuverlässige Beschreibung der Oberfächenchemie und Topologie konnte nur durch AFM und FFM Experimente erfolgen. Gleichzeitig konnte in dieser Weise die Oberflächendefektdichte und-verteilung und die Volumenauflösungsrate von a-ZPT und b-ZPT bestimmt werden. Auf einem zweiten Weg wurde eine innovative Strategie zur Herstellung von basischen Zinkphosphatpigmenten erster und zweiter Generation (d.h. NaZnPO4  1H2O und Na2ZnPO4(OH)  2H2O) mit dem Einsatz von einerseits oberflächenmodifizierten Polystyrolatices (z.B. produziert durch ein Miniemulsionspolymerisationsverfahren) und anderseits von Dendrimeren auf der Basis von Polyamidoamid (PAMAM) beschritten. Die erhaltene Zeolithstruktur (ZPO) hat in Abhängigkeit von steigendem Natrium und Wassergehalt unterschiedliche kontrollierte Morphologie: hexagonal, würfelförmig, herzförmig, sechsarmige Sterne, lanzettenförmige Dendrite, usw. Zur quantitativen Evaluierung des Polymereinbaus in der Kristallstruktur wurden carboxylierte fluoreszenzmarkierte Latices eingesetzt. Es zeigt sich, daß Polymeradditive nicht nur das Wachstum bis zu 8 µm.min-1 reduzierten. Trotzdem scheint es auch als starker Nukleationsbeschleuniger zu wirken. Dank der Koordinationschemie (d.h. Bildung eines sechszentrigen Komplexes L-COO-Zn-PO4*H2O mit Ligandenaustausch) konnten zwei einfache Mechanismen zur Wirkung von Latexpartikeln bei der ZPO Kristallisation aufgezeigt werden: (i) ein Intrakorona- und (ii) ein Extrakorona-Keimbildungsmechanismus. Weiterhin wurde die Effizienz eines Kurzzeit- und Langzeitkorrosionschutzes durch maßgeschneiderte ZPO/ZPT Pigmente und kontrollierte Freisetzung von Phosphationen in zwei Näherungen des Auslösungsgleichgewichts abgeschätzt: (i) durch eine Auswaschungs-methode (thermodynamischer Prozess) und (ii) durch eine pH-Impulsmethode (kinetischer Prozess. Besonders deutlich wird der Ausflösungs-Fällungsmechanismus (d.h. der Metamorphismus). Die wesentliche Rolle den Natriumionen bei der Korrosionshemmung wird durch ein passendes zusammensetzungsabhängiges Auflösungsmodell (ZAAM) beschrieben, das mit dem Befund des Salzsprühteste und der Feuchtigkeitskammertests konsistent ist. Schließlich zeigt diese Arbeit das herausragende Potential funktionalisierter Latices (Polymer) bei der kontrollierten Mineralisation zur Herstellung maßgeschneiderter Zinkphosphat Materialien. Solche Hybridmaterialien werden dringend in der Entwicklung umweltfreundlicher Korrosionsschutzpigmente sowie in der Dentalmedizin benötigt.

Kinematics of the Sicily and Calabria Subduction System from Elastic Block Modeling of GPS Data

We use data from about 700 GPS stations in the EuroMediterranen region to investigate the present-day behavior of the the Calabrian subduction zone within the Mediterranean-scale plates kinematics and to perform local scale studies about the strain accumulation on active structures. We focus attenction on the Messina Straits and Crati Valley faults where GPS data show extentional velocity gradients of ∼3 mm/yr and ∼2 mm/yr, respectively. We use dislocation model and a non-linear constrained optimization algorithm to invert for fault geometric parameters and slip-rates and evaluate the associated uncertainties adopting a bootstrap approach. Our analysis suggest the presence of two partially locked normal faults. To investigate the impact of elastic strain contributes from other nearby active faults onto the observed velocity gradient we use a block modeling approach. Our models show that the inferred slip-rates on the two analyzed structures are strongly impacted by the assumed locking width of the Calabrian subduction thrust. In order to frame the observed local deformation features within the present- day central Mediterranean kinematics we realyze a statistical analysis testing the indipendent motion (w.r.t. the African and Eurasias plates) of the Adriatic, Cal- abrian and Sicilian blocks. Our preferred model confirms a microplate like behaviour for all the investigated blocks. Within these kinematic boundary conditions we fur- ther investigate the Calabrian Slab interface geometry using a combined approach of block modeling and χ2ν statistic. Almost no information is obtained using only the horizontal GPS velocities that prove to be a not sufficient dataset for a multi-parametric inversion approach. Trying to stronger constrain the slab geometry we estimate the predicted vertical velocities performing suites of forward models of elastic dislocations varying the fault locking depth. Comparison with the observed field suggest a maximum resolved locking depth of 25 km.

Nanoscale-electrical and optical properties of iii-nitrides

III-nitrides are wide-band gap materials that have applications in both electronics and optoelectronic devices. Because to their inherent strong polarization properties, thermal stability and higher breakdown voltage in Al(Ga,In)N/GaN heterostructures, they have emerged as strong candidates for high power high frequency transistors. Nonetheless, the use of (Al,In)GaN/GaN in solid state lighting has already proved its success by the commercialization of light-emitting diodes and lasers in blue to UV-range. However, devices based on these heterostructures suffer problems associated to structural defects. This thesis primarily focuses on the nanoscale electrical characterization and the identification of these defects, their physical origin and their effect on the electrical and optical properties of the material. Since, these defects are nano-sized, the thesis deals with the understanding of the results obtained by nano and micro-characterization techniques such as atomic force microscopy(AFM), current-AFM, scanning kelvin probe microscopy (SKPM), electron beam induced current (EBIC) and scanning tunneling microscopy (STM). This allowed us to probe individual defects (dislocations and cracks) and unveil their electrical properties. Taking further advantage of these techniques,conduction mechanism in two-dimensional electron gas heterostructures was well understood and modeled. Secondarily, origin of photoluminescence was deeply investigated. Radiative transition related to confined electrons and photoexcited holes in 2DEG heterostructures was identified and many body effects in nitrides under strong optical excitations were comprehended.

Strategie di personalizzazione della terapia di resincronizzazione cardiaca

Solo il 60% dei candidati alla resincronizzazione cardiaca risponde in termini di rimodellamento ventricolare inverso che è il più forte predittore di riduzione della mortalità e delle ospedalizzazioni. Due cause possibili della mancata risposta sono la programmazione del dispositivo e i limiti dell’ approccio transvenoso. Nel corso degli anni di dottorato ho effettuato tre studi per ridurre il numero di non responder. Il primo studio valuta il ritardo interventricolare. Al fine di ottimizzare le risorse e fornire un reale beneficio per il paziente ho ricercato la presenza di predittori di ritardo interventricolare diverso dal simultaneo, impostato nella programmazione di base. L'unico predittore è risultato essere l’ intervallo QRS> 160 ms, quindi ho proposto una flow chart per ottimizzare solo i pazienti che avranno nella programmazione ottimale un intervallo interventricolare non simultaneo. Il secondo lavoro valuta la fissazione attiva del ventricolo sinistro con stent. I dislocamenti, la soglia alta di stimolazione del miocardio e la stimolazione del nervo frenico sono tre problematiche che limitano la stimolazione biventricolare. Abbiamo analizzato più di 200 angiografie per vedere le condizioni anatomiche predisponenti la dislocazione del catetere. Prospetticamente abbiamo deciso di utilizzare uno stent per fissare attivamente il catetere ventricolare sinistro in tutti i pazienti che presentavano le caratteristiche anatomiche favorenti la dislocazione. Non ci sono più state dislocazioni, c’è stata una migliore risposta in termini di rimodellamento ventricolare inverso e non ci sono state modifiche dei parametri elettrici del catetere. Il terzo lavoro ha valutato sicurezza ed efficacia della stimolazione endoventricolare sinistra. Abbiamo impiantato 26 pazienti giudicati non responder alla terapia di resincronizzazione cardiaca. La procedura è risultata sicura, il rischio di complicanze è simile alla stimolazione biventricolare classica, ed efficace nell’arrestare la disfunzione ventricolare sinistra e / o migliorare gli effetti clinici in un follow-up medio.

Transport properties of YBa 2 Cu 3 O 7, PrBa 2 Cu 3 O 7-superlattices

The understanding of the coupling between superconducting YBa2Cu3O7 (YBCO) layers decoupled by non superconducting PrBa2Cu3O7 (PBCO) layers in c-axis oriented superlattices was the aim of this thesis. For this purpose two conceptually different kind of transport experiments have been performed. rnrnIn the first type of transport experiments the current is flowing parallel to the layers. Here the coupling is probed indirectly using magnetic vortex lines, which are penetrating the superlattice. Movement of the vortex segments in neighbouring YBCO layers is more or less coherent depending on the thickness of both the superconducting and non superconducting layers. This in-plane transport was measured either by sending an external current through bridges patterned in the superlattice or by an induced internal current. rnThe vortex-creep activation energy U was determined by analysis of the in-plane resistive transition in an external magnetic field B oriented along the c-axis. The activation energies for two series of superlattices were investigated. In one series the thickness of the YBCO layers was constant (nY=4 unit cells) and the number of the PBCO unit cells was varied, while in the other the number of PBCO layers was constant (nP=4) and nY varied. The correlation length of the vortex system was determined to be 80 nm along the c-axis direction. It was found that even a single PBCO unit cell in a superlattice effectively cuts the flux lines into shorter weakly coupled segments, and the coupling of the vortex systems in neighbouring layers is negligible already for a thickness of four unit cells of the PBCO layers. A characteristic variation of the activation energy for the two series of superlattices was found, where U0 is proportional to the YBCO thickness. A change in the variation of U0 with the current I in the specimen was observed, which can be explained in terms of a crossover in the vortex creep process, generated by the transport current. At low I values the dislocations mediated (plastic) vortex creep leads to thermally assisted flux-flow behaviour, whereas at high current the dc transport measurements are dominated by elastic (collective) creep.rnThe analysis of standard dc magnetization relaxation data obtained for a series superlattices revealed the occurrence of a crossover from elastic (collective) vortex creep at low temperature to plastic vortex creep at high T. The crossover is generated by the T dependent macroscopic currents induced in the sample. The existence of this creep crossover suggests that, compared with the well known Maley technique, the use of the normalized vortex creep activation energy is a better solution for the determination of vortex creep parameters.rnrnThe second type of transport experiments was to measure directly a possible Josephson coupling between superconducting CuO2 double planes in the superlattices by investigation of the transport properties perpendicular to the superconducting planes. Here three different experiments have been performed. The first one was to pattern mesa structures photolithographically as in previous works. The second used three-dimensional nanostructures cut by a focused ion beam. For the these two experiments insufficient patterning capabilities prevented an observation of the Josephson effect in the current voltage curves. rnA third experiment used a-axis and (110) oriented YBCO films, where in-plane patterning can in principle be sufficient to measure transport perpendicular to the superconducting planes. Therefore the deposition of films with this unusual growth orientation was optimized and investigated. The structural and microstructural evolution of c-axis to a-axis orientation was monitored using x-ray diffraction, scanning electron microscopy and magnetization measurements. Films with full a-axis alignment parallel to the substrate normal could be achieved on (100)SrTiO3. Due to the symmetry of the substrate the c-axis direction in-plane is twofold. Transferring the deposition conditions to films grown on (110)SrTiO3 allowed the growth of (110) oriented YBCO films with a unique in-plane c-axis orientation. While these films were of high quality by crystallographic and macroscopic visual inspection, electron microscopy revealed a coherent crack pattern on a nanoscale. Therefore the actual current path in the sample was not determined by the macroscopic patterning which prohibited investigations of the in-plane anisotropy in this case.rn

Morphology of leds by atomic force microscopy

The concern of this work is to present the characterization of blue emitting GaN-based LED structures by means of Atomic Force Microscopy. Here we show a comparison among the samples with different dislocation densities, in order to understand how the dislocations can affect the surface morphology. First of all we have described the current state of art of the LEDs in the present market. Thereafterwards we have mentioned in detail about the growth technique of LED structures and the methodology of the characterization employed in our thesis. Finally, we have presented the details of the results obtained on our samples studied, followed by discussions and conclusions. L'obiettivo di questa tesi é quello di presentare la caratterizzazione mediante Microscopia a Forza Atomica di strutture di LED a emissione di luce blu a base di nitruro di gallio (GaN). Viene presentato un confronto tra campioni con differente densità di dislocazioni, allo scopo di comprendere in che modo la presenza di dislocazioni influisce sulla morfologia della superficie. Innanzitutto, viene descritto il presente stato dell'arte dei LED. Successivamente, sono forniti i dettagli riguardanti la tecnica di crescita delle strutture dei LED e il metodo di caratterizzazione adottato. Infine, vengono mostrati e discussi i risultati ottenuti dallo studio dei campioni, seguiti dalle conclusioni.

Surgical treatment of upper, middle and lower cervical injuries and non-unions by anterior procedures

The goals of any treatment of cervical spine injuries are: return to maximum functional ability, minimum of residual pain, decrease of any neurological deficit, minimum of residual deformity and prevention of further disability. The advantages of surgical treatment are the ability to reach optimal reduction, immediate stability, direct decompression of the cord and the exiting roots, the need for only minimum external fixation, the possibility for early mobilisation and clearly decreased nursing problems. There are some reasons why those goals can be reached better by anterior surgery. Usually the bony compression of the cord and roots comes from the front therefore anterior decompression is usually the procedure of choice. Also, the anterior stabilisation with a plate is usually simpler than a posterior instrumentation. It needs to be stressed that closed reduction by traction can align the fractured spine and indirectly decompress the neural structures in about 70%. The necessary weight is 2.5 kg per level of injury. In the upper cervical spine, the odontoid fracture type 2 is an indication for anterior surgery by direct screw fixation. Joint C1/C2 dislocations or fractures or certain odontoid fractures can be treated with a fusion of the C1/C2 joint by anterior transarticular screw fixation. In the lower and middle cervical spine, anterior plating combined with iliac crest or fibular strut graft is the procedure of choice, however, a solid graft can also be replaced by filled solid or expandable vertebral cages. The complication of this surgery is low, when properly executed and anterior surgery may only be contra-indicated in case of a significant lesion or locked joints.

A Laboratory Experiment Using Nanoindentation to Demonstrate the Indentation Size Effect

A laboratory experiment using nanoindentation to demonstrate the indentation size effect is described. This laboratory introduces students to sophisticated instrumentation at low cost and low risk and utilizes recent research in the materials community as its foundation. The motivation, learning objectives, experimental details, data, and data analysis are presented. This experiment is intended for use in an upper-division materials science elective at the university level and has been successfully used in laboratory courses for senior undergraduates and first-year graduate students at Stanford University and Santa Clara University.

Epidemiology and predictors of spinal injury in adult major trauma patients: European cohort study

This is a European cohort study on predictors of spinal injury in adult (≥16 years) major trauma patients, using prospectively collected data of the Trauma Audit and Research Network from 1988 to 2009. Predictors for spinal fractures/dislocations or spinal cord injury were determined using univariate and multivariate logistic regression analysis. 250,584 patients were analysed. 24,000 patients (9.6%) sustained spinal fractures/dislocations alone and 4,489 (1.8%) sustained spinal cord injury with or without fractures/dislocations. Spinal injury patients had a median age of 44.5 years (IQR = 28.8-64.0) and Injury Severity Score of 9 (IQR = 4-17). 64.9% were male. 45% of patients suffered associated injuries to other body regions. Age <45 years (≥45 years OR 0.83-0.94), Glasgow Coma Score (GCS) 3-8 (OR 1.10, 95% CI 1.02-1.19), falls >2 m (OR 4.17, 95% CI 3.98-4.37), sports injuries (OR 2.79, 95% CI 2.41-3.23) and road traffic collisions (RTCs) (OR 1.91, 95% CI 1.83-2.00) were predictors for spinal fractures/dislocations. Age <45 years (≥45 years OR 0.78-0.90), male gender (female OR 0.78, 95% CI 0.72-0.85), GCS <15 (OR 1.36-1.93), associated chest injury (OR 1.10, 95% CI 1.01-1.20), sports injuries (OR 3.98, 95% CI 3.04-5.21), falls >2 m (OR 3.60, 95% CI 3.21-4.04), RTCs (OR 2.20, 95% CI 1.96-2.46) and shooting (OR 1.91, 95% CI 1.21-3.00) were predictors for spinal cord injury. Multilevel injury was found in 10.4% of fractures/dislocations and in 1.3% of cord injury patients. As spinal trauma occurred in >10% of major trauma patients, aggressive evaluation of the spine is warranted, especially, in males, patients <45 years, with a GCS <15, concomitant chest injury and/or dangerous injury mechanisms (falls >2 m, sports injuries, RTCs and shooting). Diagnostic imaging of the whole spine and a diligent search for associated injuries are substantial.

Hip abductor defect repair by means of a vastus lateralis muscle shift

Scarring or detachment of the hip abductors, particularly of the gluteus medius, from their insertion may lead to severe abductor weakness, recurrent dislocations, pain, and diminished quality of life. We performed a retrospective study to evaluate whether vastus lateralis shift is associated with satisfactory results and low rate of complications. Eleven adults underwent vastus lateralis shift to bridge a well-documented abductor muscles' insertion defect. Preoperative and postoperative hip functions were assessed applying the Merle d'Aubigne score, British Medical Council scale, and Visual Analog Scale. Significant postoperative improvement was noted in mean Merle d'Aubigne score, gluteus medius muscle force, and quality of life. Vastus lateralis shift represents a viable treatment option for hip abductor deficiency, significantly improving abductor strength and overall quality of life.

Two- to 9-year clinical results of alumina ceramic-on-ceramic THA

From June 1997 to June 2003 we performed 194 total hip arthroplasties on 173 patients using alumina ceramic-on-ceramic bearings as part of a prospective United States Food and Drug Administration/Investigational Device Exemption study. The average patient age at surgery was 49.9 years. Minimum followup time was 2 years (mean 4.3 years, range 2-9 years). We evaluated survival rate, implant- and nonimplant-related complications. Clinical outcomes included the Merle d'Aubigné score. We assessed radiographs for signs of osteolysis, component loosening, and implant wear. No patients had osteolysis and there were no hip dislocations. Implant survivorship for all hips with aseptic revision of any component was 96% (CI, 91-100) at 9 year; survivorship for hips without prior surgery was 99.3%, (CI, 98-100). There was a 1.7% incidence of implant-related complications. Our data help confirm two United States FDA/IDE studies on alumina ceramic-on-ceramic total hip arthroplasty that reported low aseptic revision rates and low revision rates for instability. Total hip arthroplasty using alumina ceramic-on-ceramic implants is a safe and reliable procedure in the comparably young and active patient.