Ermüdungsfestigkeit von Stumpfnahtverbindungen größerer Blechdicke gefügt mit Hochleistungsschweißverfahren

In vielen Bereichen des Ingenieurwesens gehört das Schweißen zu den maßgebenden und am häufigsten angewendeten Verbindungstechniken. Auch für Tragstrukturen von Windenergieanlagen, zu denen u. a. Türme und Monopiles gehören, sind stumpfgestoßene, dickwandige Schweißverbindungen charakteristisch. Durch die zunehmenden Dimensionen und Beanspruchungen geraten konventionelle Hochleistungsfügeverfahren wie das Unterpulverschweißen an die Grenzen ihrer technischen Umsetzbarkeit. Gleiches gilt auch für das Design und die Bemessung dieser Verbindungen. Zum Nachweis der Ermüdungssicherheit ist bisher das Nennspannungskonzept, basierend auf experimentell ermittelten Wöhlerlinien, Stand der Technik und maßgebend in gültigen Bemessungsnormen wie dem Eurocode 3. Dieses Verfahren ist einfach in der Anwendung, bietet aber kaum Möglichkeiten, lokale Nahteigenschaften zu berücksichtigen und so zu einer individuellen Dimensionierung zu gelangen. Die vorliegende Arbeit leistet einen Beitrag zu einer zuverlässigen Lebensdauerprog-nose auf Basis lokaler Ermüdungskonzepte, indem sie die Anwendbarkeit des Zwei-Phasenmodells, d. h. einer Kombination aus Kerbdehnungs- und Rissfortschrittskonzept, für die Bemessung von dickwandigen Stumpfstößen untersucht. Wesentliche Eingangsgrößen für dieses Modell sind die aus der Nahtgeometrie resultierende, elastische Spannungserhöhung und die lokale, inhomogene Festigkeitsverteilung über den Nahtquerschnitt. In großem Umfang wurden daher die Nahtprofile der Schweißproben vor der Schwingprüfung messtechnisch erfasst und durch entsprechende Filter für die numerische Analyse der Kerbformzahlen aufbereitet. Erst durch das Filtern mit entsprechender Grenzwellenlänge werden Messdaten vereinheitlicht und grundsätzlich vergleichbar. Für das Qualitätsmanagement innerhalb der Schweißfertigung und auch den direkten Eingang in Bemessungskonzepte ist dieser Schritt essentiell. Am Ende der Untersuchung steht eine umfassende Datenbasis zur Kerbgeometrie stumpfgeschweißter Verbindungen. Diese lokalen Nahtgeometrieeigenschaften und aus der Härte umgewertete Festig-keitsverteilungen über den Querschnitt bilden nun die maßgebenden Eingangspara-meter für das Zwei-Phasenmodell. Die Validierung an experimentell ermittelten Schwingfestigkeiten zeigt die Anwendbarkeit und das Potential des Modells. Die erreichte Prognosegüte für verschiedene Stahlwerkstoffe und Randbedingungen ist hoch. Durch die große Datenbasis ist es möglich, statistische Verteilungen dieser Eingangsparameter abzuleiten und im Rahmen stochastischer Monte-Carlo-Simulationen zu untersuchen. Das Potential lokaler Nachweiskonzepte für eine wirtschaftliche und sichere Bemessung großer Stahlstrukturen kann damit eindeutig aufgezeigt werden

The Relationship Between Denial and Behavior Pattern in the Patient Experiencing Myocardial Infarction

Denial has been recognized as a possible adaptation mechanism for patients with heart disease, stroke, brain damage, cancer, emphysema, manic-depressive psychos is, and neurologic disorders. Croog and coworkers discovered that twenty percent of 345 men treated for three weeks after a first myocardial infarction denied they had even had a heart attack. The problem under investigation in this study is: What is the relationship between the use of denial as a form of adaptation and the type of behavior pattern reflected in male patients within two weeks of admission to a coronary care unit with a diagnosis of myocardial infarction? Research indicates that the use of denial as a form of adaptation by myocardial infarction patients tends to decrease mortality in the immediate, forty-eight hour post infarction period, but decreases compliance in the post-hospitalization period. Therefore, cardiovascular nurses could assume that assessment of the use of denial might be important for increasing patient compliance towards cardiac rehabilitation in the myocardial infarction patient. If nurses can determine that the use of denial is associated with a particular behavior pattern, such as the Type A behavior pattern who are at high risk for myocardial infarction, nurses can develop plans of care with those individuals which would increase compliance in post-hospitalization. The objectives of this study are the following: 1. To determine the frequency of denial used by the male patient experiencing myocardial infarction according to the response to the Hackett-Cassem Denial Scale. 2. To determine whether the Type A behavior pattern or the Type B behavior pattern is reflected by the male patient experiencing myocardial infarction according to the response to the Jenkins Activity Survey. 3. To determine if there is a relationship between the use of denial as a form of adaptation and the type of behavior pat tern reflected by the male patient experiencing myocardial infarction

Determination of Loading and Residual Stresses on Offshore Jacket Structures by X-ray Diffraction

As basements of offshore wind turbines (OWTs) in deep water (>50 m), jacket structures are an economic alternative to monopiles. For this reason, the structural durability of jackets has become more important. In such structures, welded tubular joints are weak points for fatigue design. The harmful effect of tensile residual stresses in welding joints is well known. For these reasons, the residual stresses and the loading stresses of offshore jacket structures were determined by X-ray diffraction (XRD) using a mobile diffractometer. This allows us to directly determine the load stress at the fatigue-critical locations, namely at the weld toe at the testing rig. High tensile residual stresses up to 250 MPa were determined in a welded (and unloaded) condition. At a loaded structure (10,000 load cycles), a lower residual stress level was determined. During loading, a local increase in the stress at the welded joint that is between 1.4 and 4 times higher than the applied nominal stress was determined. Furthermore, it is shown that additional treatment (grinding and clean blasting) influences the local stress state significantly

Влияние культуры на экологическое сознание

В работе рассматривается взаимодействие экологии и культуры, влияние искусства на человеческое сознание и формирование взгляда на природу как на самостоятельную ценность, что делает безальтернативным вариант коэволюционного развития. Показан масштаб глобального экологического кризиса, важность работ Вернадского по ноосфере, новые не только природные, но и социокультурные реальности. Рассматриваются варианты выхода из создавшейся сложной экологической ситуации.This paper considered the interaction between ecology and culture, the influence of art on human consciousness and the formation of a view of nature as an independent value that makes the only option of co-evolutional development. Shows the scale of the global environmental crisis, the importance of the work of Vernadsky on the noosphere, new not only natural but also socio-cultural reality. Discusses options for overcoming the current dangerous ecological situation

Teleconsultation/telediagnosis using teledentistry technology: a pilot feasibility study

Abstract—This study assessed the feasibility of a teledentistry model for teleconsultation and telediagnosis in Residential Aged Care Facilities. Study feasibility was defined by the ability to develop remote treatment plans. Reliability of the remote assessments was assessed by comparing with those performed by traditional face-to-face oral examinations. An intraoral camera was operated by trained teledentistry assistants with the aim of screening residents for oral diseases and pathological conditions. The model was supported by traning and an instructional kit for the introral camera operators. The structure, content and delivery of the program, was evaluated. Residents ’ views about the structure, content and delivery of the program were also evaluated. A total of 50 residents participated in this assessment. Results indicated that the proposed teledentistry approach for oral health screening is feasible and reliable as an alternative to traditional oral health examination. Residents expressed high levels of satisfaction with the teledentistry service. This study provides an innovative solution towards closing the service delivery gap in the provision of sustainable oral health care services to underserviced populations (e.g., nursing homes, rural areas)

Effective NSAID treatment indicates that hyperprostaglandinism is affecting the clinical severity of childhood hypophosphatasia

BACKGROUND: Hypophosphatasia (HP) is an inborn error of bone metabolism characterized by a genetic defect in the gene encoding the tissue-nonspecific alkaline phosphatase (TNSALP). There is a lack of knowledge as to how the variability and clinical severity of the HP phenotype (especially pain and walking impairment) are related to metabolic disturbances or impairments, subsequent to the molecular defect. METHODS: We analyzed the changes in clinical symptoms and the prostaglandin (PG) metabolism in response to treatment with non-steroidal anti-inflammatory drugs (NSAIDs) in six children affected by childhood HP. In addition, by exposing HP fibroblasts to pyridoxal phosphate and/or calcium pyrophosphate in vitro, we analyzed whether the alterations in PG levels are sequelae related to the metabolic defect. RESULTS: Childhood HP patients, who often complain about pain in the lower limbs without evident fractures, have systemic hyperprostaglandinism. Symptomatic anti-inflammatory treatment with NSAIDs significantly improved pain-associated physical impairment. Calcium pyrophosphate, but not pyridoxal phosphate, induced cyclooxygenase-2 (COX-2) gene expression and PG production in HP and normal fibroblasts in vitro. CONCLUSION: Clinical features of childhood HP related to pain in the lower legs may be, at least in part, sequelae related to elevated PG levels, secondary to the primary metabolic defect. Consequently, NSAID treatment does improve the clinical features of childhood HP

High definition 3D telemedicine: The next frontier?

Evidence from the literature indicates that the degree of immersion often referred to as the "sense of being there" experienced by clinicians and patients is a factor in the success of tele-health installations. High definition and 3D telemedicine offers a compelling mechanism to achieve a sense of immersion and contribute to an enhanced quality of use. This article surveys HD3D trials in tele-health and concludes that the way HD3D is integrated into telemedicine depends on the clinical, organisational and technological context. In some settings real time HD3D is not so desirable whereas asynchronous transmission of HD3D images and videos is highly desirable. © 2012 The authors and IOS Press

Pentraxin-3 is a PI3K signaling target that promotes stem cell–like traits in basal-like breast cancers

Basal-like breast cancers (BLBCs) exhibit hyperactivation of the phosphoinositide 3-kinase (PI3K) signaling pathway because of the frequent mutational activation of the PIK3CA catalytic subunit and the genetic loss of its negative regulators PTEN (phosphatase and tensin homolog) and INPP4B (inositol polyphosphate-4-phosphatase type II). However, PI3K inhibitors have had limited clinical efficacy in BLBC management because of compensatory amplification of PI3K downstream signaling loops. Therefore, identification of critical PI3K mediators is paramount to the development of effective BLBC therapeutics. Using transcriptomic analysis of activated PIK3CA-expressing BLBC cells, we identified the gene encoding the humoral pattern recognition molecule pentraxin-3 (PTX3) as a critical target of oncogenic PI3K signaling. We found that PTX3 abundance is stimulated, in part, through AKT- and nuclear factor κB (NF-κB)-dependent pathways and that presence of PTX3 is necessary for PI3K-induced stem cell-like traits. We further showed that PTX3 expression is greater in tumor samples from patients with BLBC and that it is prognostic of poor patient survival. Our results thus reveal PTX3 as a newly identified PI3K-regulated biomarker and a potential therapeutic target in BLBC

Web Vulnerability Study of Online Pharmacy Sites

Consumers are increasingly using online pharmacies, but these sites may not provide an adequate level of security with the consumers’ personal data. There is a gap in this research addressing the problems of security vulnerabilities in this industry. The objective is to identify the level of web application security vulnerabilities in online pharmacies and the common types of flaws, thus expanding on prior studies. Technical, managerial and legal recommendations on how to mitigate security issues are presented. The proposed four-step method first consists of choosing an online testing tool. The next steps involve choosing a list of 60 online pharmacy sites to test, and then running the software analysis to compile a list of flaws. Finally, an in-depth analysis is performed on the types of web application vulnerabilities. The majority of sites had serious vulnerabilities, with the majority of flaws being cross-site scripting or old versions of software that have not been updated. A method is proposed for the securing of web pharmacy sites, using a multi-phased approach of technical and managerial techniques together with a thorough understanding of national legal requirements for securing systems