Simulation of failure of air plasma sprayed thermal barrier coating due to interfacial and bulk cracks using surface-based cohesive interaction and extended finite element method

This article describes a method of predicting the failure of a thermal barrier coating system due to interfacial cracks and cracks within bulk coatings. The interfacial crack is modelled by applying cohesive interfaces where the thermally grown oxide is bonded to the ceramic thermal barrier coating. Initiation and propagation of arbitrary cracks within coatings are modelled using the extended finite element method. Two sets of parametric studies were carried out, concentrating on the effect of thickness of the oxide layer and that of initial cracks within the ceramic coating on the growth of coating cracks and the subsequent failures. These studies have shown that a thicker oxide layer creates higher tensile residual stresses during cooling from high temperature, leading to longer coating cracks. Initial cracks parallel to the oxide interface accelerate coating spallation, and simulation of this process is presented in this article. By contrast, segmented cracks prevent growth of parallel cracks which can lead to spallation

Experimental and Numerical Study of the Dispersion and Transport of Automobile Exhaust Gases from Highways

This paper describes examples of modelling and of measurements of the dispersion and transport of exhaust gases from automobiles on a highway. Model runs were performed by a large-eddy-simulation model. The measurements were carried through by the DLR environmental research aircraft lee-side of the highway between München and Augsburg

Occurrence of Livestock-Associated Methicillin-Resistant Staphylococcus aureus in Turkey and Broiler Barns and Contamination of Air and Soil Surfaces in Their Vicinity

The emission of microorganisms, especially resistant bacteria such as methicillin-resistant Staphylococcus aureus (MRSA), from poultry farms is of public interest, and its occurrence and relevance are controversially discussed. So far, there are limited data on this issue. In this study, we investigated the occurrence of livestock-associated (LA)-MRSA inside and outside previously tested MRSA-positive poultry barns in Germany. In total, five turkey and two broiler fattening farms were investigated four and three times, respectively. In a longitudinal study during one fattening period, samples were collected from animals, the animals' environment inside the barn, including the air, and the barns' surroundings, such as ambient air and boot swabs of ground surfaces at different distances from the barn. Moreover, a cross-sectional study was carried out once inside the barns on five turkey and four broiler farms during the last third of the fatting period. In the cross- sectional study, LA-MRSA was detected in the air of most barns (7 of 9, 77.8%), as well as in many samples originating from animals, with detections levels of 50 to 54% in broiler and 62 to 77% in turkey farms. In the longitudinal study, LA-MRSA was found in the ambient air outside two turkey barns and on the ground surface on the downwind side of many (44.4%) turkey and broiler farms. The same spa types of isolates were observed inside and outside the barns. Transmission of MRSA within poultry farms, as well as emission via the airborne route, seems to be possible

Glossopterideas de fluviópolis (permiano superior) no sul do Estado do Parana

This paper describes the Glossopteris species of a compact carbonaceous siltstone of the Upper Permian Serra Alta (or Terezina?) Formation (Paraná Basin), cropping out along the right margin of the Iguacu River, néar Fluviópolis, State of Parana, southern Brazil. The study of over 100 specimens related to the genus Glossopteris showed that they predominantly are of two possibly new species. However, because the small number of specimens with well preserved venation does not constitute an adequate basis for the creation of new species, the specimens are here referred to Glossopteris cf. G. occidentalis and Glossopteris cf. G. angustifoliaO presente trabalho descreveve as glossopterídeas procedentes de um afloramento de siltitos calcíferos compactos, provavelmente pertencentes à Formação Serra Alta, e situado à margem direita do Rio Iguaçu, próximo a Fluviópolis, no Estado do Paraná. Foram coletadas mais de 100 amostras de glossopterídeas que aparecem como finas películas carbonosas, já sem estrutura ou preservação de cutícula. Após a retirada das películas, observam-se impressões corn qualidade variável. São descritas duas formas: uma apresentando uma nervura mediana bastante larga, estriada lon-gitudinalmente e bem marcada. As nervuras secundárias emergem em ângulo bastante agudo, sofrem dicotomias e anastomoses próximo da nervura mediana e se encurvam abruptamente alcançanda a margem em ângulos de cerca de 80º. Apresentam maior semelhança com G. occidentalis da qual diferem, sobretudo, por apresentarem tamanho médio bem menor dos espécimes. Um segundo grupo de formas, representado principalmente pela porção médio-apical do limbo foliar, foi determinado como Glossopteris cf. G. angustifoli

Primary cervical malignant teratoma with a rib metastasis in an adult: Five-year survival after surgery and chemotherapy: A case report with a review of the literature

We report a case of a man presenting with a cervical malignant teratoma and a chondrosarcomatous rib metastasis. He was alive and free of recurrence five years and 10 months (= 70 months) after resection of the primary mass, followed by chemotherapy and subsequent resection of the rib tumor. This is the 35th patient reported in the literature and the first description in which an ‘adjuvant' or primary chemotherapy was used. Previous patients with a cervical malignant teratoma, reported after lethal outcome, had survivals of one to 22 months (median nine months). In all patients with a preoperative clinical impression of an aggressive, differentiated or undifferentiated malignancy, the definite diagnosis of teratoma could only be made histologically. By analogy to germ cell tumors, the prognosis of malignant teratoma might be improved if complete excision is combined with new, adjuvant chemotherapy protocols for germ cell tumors. Lessons learned from this case are placed in the context of germ cell tumors in general and of non-gonadal malignant teratomas in particula

The discretised harmonic oscillator: Mathieu functions and a new class of generalised Hermite polynomials

We present a general, asymptotical solution for the discretised harmonic oscillator. The corresponding Schr\"odinger equation is canonically conjugate to the Mathieu differential equation, the Schr\"odinger equation of the quantum pendulum. Thus, in addition to giving an explicit solution for the Hamiltonian of an isolated Josephon junction or a superconducting single-electron transistor (SSET), we obtain an asymptotical representation of Mathieu functions. We solve the discretised harmonic oscillator by transforming the infinite-dimensional matrix-eigenvalue problem into an infinite set of algebraic equations which are later shown to be satisfied by the obtained solution. The proposed ansatz defines a new class of generalised Hermite polynomials which are explicit functions of the coupling parameter and tend to ordinary Hermite polynomials in the limit of vanishing coupling constant. The polynomials become orthogonal as parts of the eigenvectors of a Hermitian matrix and, consequently, the exponential part of the solution can not be excluded. We have conjectured the general structure of the solution, both with respect to the quantum number and the order of the expansion. An explicit proof is given for the three leading orders of the asymptotical solution and we sketch a proof for the asymptotical convergence of eigenvectors with respect to norm. From a more practical point of view, we can estimate the required effort for improving the known solution and the accuracy of the eigenvectors. The applied method can be generalised in order to accommodate several variables.Comment: 18 pages, ReVTeX, the final version with rather general expression

Functional improvement and correlations with symptomatic improvement in adults with attention deficit hyperactivity disorder receiving long-acting methylphenidate

Item does not contain fulltextBACKGROUND: Data on the relationship between core symptoms and daily functioning in adults with attention deficit hyperactivity disorder (ADHD) are limited. Daily functioning was assessed as part of an open-label extension, and associations with symptom scores were evaluated. METHOD: After a 5-week double-blind study with adults with ADHD receiving osmotic-controlled release oral delivery system (OROS) methylphenidate (MPH) 18, 36 or 72 mg/day, or placebo, participants were eligible for a 7-week open-label extension in which all patients received OROS MPH. Data for the Conners' Adult ADHD Rating Scale - Observer: Screening Version (CAARS-O:SV) (primary endpoint) have been presented previously. Secondary endpoints included the observer self-reported short version of the CAARS (CAARS-S:S) and the Clinical Global Impressions - Severity Scale (CGI-S). Daily functioning and quality of life were assessed using the Sheehan Disability Scale (SDS) and the Quality of Life Enjoyment and Satisfaction Questionnaire (Q-LES-Q) respectively. In post-hoc analyses, changes in CAARS-O:SV were evaluated in subgroups. Relationships between symptom and functional outcomes were evaluated in a multivariate regression analysis. RESULTS: A total of 370 patients entered the open-label extension. Significant improvements from baseline in CAARS-O:SV were similar regardless of sex, ADHD subtype, prior treatment or psychiatric co-morbidity. Significant improvements from double-blind baseline were also seen for the CAARS-S:S, CGI-S, SDS and Q-LES-Q. Improvements in the CAARS-O:SV Hyperactivity/Impulsivity subscale were associated with improvements in SDS total and subscale scores, and in the Q-LES-Q score at open-label endpoint. Improvements in CAARS-O:SV Inattention subscale and CGI-S scores were not significantly associated with functional changes. CONCLUSIONS: Improvements in ADHD symptoms relating to hyperactivity and impulsivity in adults receiving OROS MPH are associated with improvements in daily functioning and quality of life.1 januari 201