Vergleichende Betrachtung unterschiedlicher Schwenkdämpfermodelle auf die Stabilität eines Rotorblattes

Es wird das einfache Modell eines viskos gedämpften Rotorsystems betrachtet. Die dazugehörigen Differentialgleichungen werden hergeleitet und verifiziert. Anschließend werden Elastomerdämpfer vorgestellt und verschiedene Modelle zur Modellierung dieser erläutert. Ein Modell wird ausgewählt und in das Rotorsystem integriert. Nachfolgend werden Fluidelastikdämpfer erläutert und deren Modellierungsmöglichkeiten dargestellt. Die Integration eines ausgewählten Modells wird vorbereitet

Ecological and Economic Feasibility of Inductive Heating for Sustainable Press Hardening Processes

Press hardening is an established process for the production of high-strength lightweight structural automotive parts, like the B-pillar. While lightweight design is an important aspect of emission reduction during the use phase, emissions arising in other phases of the automotive lifecycle also need to be considered. Roller-hearth-furnaces, as used during the press hardening process, present a non-negligible source of greenhouse gas emissions in part production processes. Alternative heating methods, such as inductive heating, may pose a possibility to reduce emissions during the manufacturing process, while also offering additional advantages in high process flexibility, high energy efficiency and low space requirements. However, there are multiple challenges when it comes to inductive heating of sheet metal for industrial processes, such as homogeneity of heating and resulting material properties. Therefore, various investigation on the usability of inductive heating for press hardening process have been conducted. Recently, an inductive heating process utilizing a longitudinal field inductor for industrial press hardening has been developed, showing good results in regard to process homogeneity, heating times and material properties. This process is used as a baseline for an ecological and economical assessment of inductive heating for industrial press hardening processes in comparison to traditional gas-fired furnaces. The reference values for a comparison on cost and emission are based on a gas-fired conveyor furnace with constant speed used for the heating of sheet metal for press hardening. The share of furnace operation modes, like standby and production with varying good-mass flows, as well as resulting natural gas demands are provided. From this data, specific energy requirements of heated sheet metal can be derived for various material mass flows and utilization scenarios, which serve as a baseline for the cost and emission comparison.  The objective of this study is to determine the emissions and costs for inductive heating compared to conventional gas-fired roller-hearth furnaces for different parameter-set of boundary conditions like product mass flow, energy prices, emission factors depending on energy transition scenarios. Based on this evaluation matrix, break-even conditions favoring inductive heating can be identified.&nbs

Fearful or functional - a cross-sectional survey of the concepts of childhood fever among German and Turkish mothers in Germany

<p>Abstract</p> <p>Background</p> <p>Fever is one of the most common presenting complaints in paediatrics and general practice. In the majority of cases nothing harmful is diagnosed. However, the subjective meaning of fever often varies between doctors and parents. Knowledge of the parents' concept of fever may help tailor counselling to their needs.</p> <p>In this study we determine 1) the influence of socio-economic status and cultural background on two concepts of fever which we labelled "functional" and "fearful", each representing typical experiences of mothers, and 2) the actions taken by the mothers related to these concepts.</p> <p>Methods</p> <p>A standardized interview study was conducted among German and Turkish mothers in Germany in 2009. The questionnaire consisted of 36 questions and 205 items. Interviews were conducted in 16 private practices of paediatricians and 2 paediatric emergency departments in an urban region of Germany. The two fever concepts were represented in 6 statements that could be rated with a six-point Likert scale. The association of the socio-economic status and the cultural background with one of the fever concepts was determined by a multiple logistic regression.</p> <p>Results</p> <p>A total of 338 mothers (49% with a Turkish background) completed the interview (response rate 92%). The average age of mothers with a German background was higher (34.1 years vs. 32.0 years, p = 0.0001). Mothers with a Turkish background were more likely to relate to the concept "fearful" [adjusted Odds Ratio (AOR) 1.99; confidence interval (CI) 1.16-3.44]. Mothers with a middle or high socio-economic status were more likely to respond to the concept "functional" [middle: AOR, 0.53; CI, 0.30-0.92; high: AOR, 0.44; CI, 0.21-0.95].</p> <p>Mothers adhering to the concept "fearful" more often gave acetaminophen before the recommended interval of 6 hours (46.8% vs. 31.3%, p = 0.005) and visited out-of-hours services more frequently in the preceding 9 months than the other group (0.7 vs. 0.4, p = 0.001).</p> <p>Conclusions</p> <p>A Turkish migrant background and a low socio-economic status are associated with the fever concept "fearful". Mothers with these attributes seem to require specific and reassuring counselling as they use antipyretic drugs extensively and out-of-hours services frequently.</p

Электромагнитная система забора отработанных шариковых породоразрушающих элементов для шароструйно-эжекторного бурового снаряда

Цель работы: провести анализ шароструйного способа бурения и разработать конструкцию электромагнитного улавливающего устройства. В процессе исследования проводились: обзор и анализ существующих конструкций буровых снарядов, оценочный расчет параметров улавливающего устройства, проработка конструкции. В результате исследования: была предложена конструкция электромагнитного улавливающего устройства. Степень внедрения: разработана конструкция.The object of the study are: bottom-hole processes in pellet impact drilling. Objective: to analyze pellet impact drilling method of drilling and to develop the construction of the electromagnetic capture device. In the process of the conducted research: a review and analysis of existing designs of drilling shells, the estimated calculation of the parameters of the capture device, the design of the structure. The study: was the proposed design of the electromagnetic capture device. Level of implementation: the developed design

Occult hypoperfusion and changes of systemic lipid levels after severe trauma: an analysis in a standardized porcine polytrauma model

BACKGROUND: Occult hypoperfusion describes the absence of sufficient microcirculation despite normal vital signs. It is known to be associated with prolonged elevation of serum lactate and later complications in severely injured patients. We hypothesized that changes in circulating lipids are related to responsiveness to resuscitation. The purpose of this study is investigating the relation between responsiveness to resuscitation and lipidomic course after poly trauma. METHODS: Twenty-five male pigs were exposed a combined injury of blunt chest trauma, liver laceration, controlled haemorrhagic shock, and femoral shaft fracture. After 1 h, animals received resuscitation and fracture stabilization. Venous blood was taken regularly and 233 specific lipids were analysed. Animals were divided into two groups based on serum lactate level at the end point as an indicator of responsiveness to resuscitation (<2 mmol/L: responder group (R group), ≧2 mmol/L: occult hypoperfusion group (OH group)). RESULTS: Eighteen animals met criteria for the R group, four animals for the OH group, and three animals died. Acylcarnitines showed a significant increase at 1 h compared to baseline in both groups. Six lipid subgroups showed a significant increase only in R group at 2 h. There was no significant change at other time points. CONCLUSIONS: Six lipid groups increased significantly only in the R group at 2 h, which may support the idea that they could serve as potential biomarkers to help us to detect the presence of occult hypoperfusion and insufficient resuscitation. We feel that further study is required to confirm the role and mechanism of lipid changes after trauma

Adenosine/A2B receptor signaling ameliorates the effects of ageing and counteracts obesity

The combination of aging populations with the obesity pandemic results in an alarming rise in non-communicable diseases. Here, we show that the enigmatic adenosine A2B receptor (A2B) is abundantly expressed in skeletal muscle (SKM) as well as brown adipose tissue (BAT) and might be targeted to counteract age-related muscle atrophy (sarcopenia) as well as obesity. Mice with SKM-specific deletion of A2B exhibited sarcopenia, diminished muscle strength, and reduced energy expenditure (EE), whereas pharmacological A2B activation counteracted these processes. Adipose tissue-specific ablation of A2B exacerbated age-related processes and reduced BAT EE, whereas A2B stimulation ameliorated obesity. In humans, A2B expression correlated with EE in SKM, BAT activity, and abundance of thermogenic adipocytes in white fat. Moreover, A2B agonist treatment increased EE from human adipocytes, myocytes, and muscle explants. Mechanistically, A2B forms heterodimers required for adenosine signaling. Overall, adenosine/A2B signaling links muscle and BAT and has both anti-aging and anti-obesity potential

Cannabinoid Type 1 Receptors Are Upregulated During Acute Activation of Brown Adipose Tissue

Activating brown adipose tissue (BAT) could provide a potential approach for the treatment of obesity and metabolic disease in humans. Obesity is associated with upregulation of the endocannabinoid system, and blocking the cannabinoid type 1 receptor (CB1R) has been shown to cause weight loss and to decrease cardiometabolic risk factors. These effects may be mediated partly via increased BAT metabolism, since there is evidence that CB1R antagonism activates BAT in rodents. To investigate the significance of CB1R in BAT function, we quantified the density of CB1R in human and rodent BAT using the positron emission tomography radioligand [F-18]FMPEP-d(2) and measured BAT activation in parallel with the glucose analog [F-18]fluorodeoxyglucose. Activation by cold exposure markedly increased CB1R density and glucose uptake in the BAT of lean men. Similarly, 3-receptor agonism increased CB1R density in the BAT of rats. In contrast, overweight men with reduced BAT activity exhibited decreased CB1R in BAT, reflecting impaired endocannabinoid regulation. Image-guided biopsies confirmed CB1R mRNA expression in human BAT. Furthermore, CB1R blockade increased glucose uptake and lipolysis of brown adipocytes. Our results highlight that CB1Rs are significant for human BAT activity, and the CB1Rs provide a novel therapeutic target for BAT activation in humans

Lipolysis drives expression of the constitutively active receptor GPR3 to induce adipose thermogenesis

Thermogenic adipocytes possess a therapeutically appealing, energy-expending capacity, which is canonically cold-induced by ligand-dependent activation of β-adrenergic G protein-coupled receptors (GPCRs). Here, we uncover an alternate paradigm of GPCR-mediated adipose thermogenesis through the constitutively active receptor, GPR3. We show that the N terminus of GPR3 confers intrinsic signaling activity, resulting in continuous Gs-coupling and cAMP production without an exogenous ligand. Thus, transcriptional induction of Gpr3 represents the regulatory parallel to ligand-binding of conventional GPCRs. Consequently, increasing Gpr3 expression in thermogenic adipocytes is alone sufficient to drive energy expenditure and counteract metabolic disease in mice. Gpr3 transcription is cold-stimulated by a lipolytic signal, and dietary fat potentiates GPR3-dependent thermogenesis to amplify the response to caloric excess. Moreover, we find GPR3 to be an essential, adrenergic-independent regulator of human brown adipocytes. Taken together, our findings reveal a noncanonical mechanism of GPCR control and thermogenic activation through the lipolysis-induced expression of constitutively active GPR3.ISSN:0092-8674ISSN:1097-417

Terrestrial laser scanning in forest inventories

AbstractDecision making on forest resources relies on the precise information that is collected using inventory. There are many different kinds of forest inventory techniques that can be applied depending on the goal, scale, resources and the required accuracy. Most of the forest inventories are based on field sample. Therefore, the accuracy of the forest inventories depends on the quality and quantity of the field sample. Conventionally, field sample has been measured using simple tools. When map is required, remote sensing materials are needed. Terrestrial laser scanning (TLS) provides a measurement technique that can acquire millimeter-level of detail from the surrounding area, which allows rapid, automatic and periodical estimates of many important forest inventory attributes. It is expected that TLS will be operationally used in forest inventories as soon as the appropriate software becomes available, best practices become known and general knowledge of these findings becomes more wide spread. Meanwhile, mobile laser scanning, personal laser scanning, and image-based point clouds became capable of capturing similar terrestrial point cloud data as TLS. This paper reviews the advances of applying TLS in forest inventories, discusses its properties with reference to other related techniques and discusses the future prospects of this technique

Flugbahnplanung für unbemannte Kleinflugzeuge unter Berücksichtigung der Flugleistung in einem uniformen Windfeld

In der vorliegenden Arbeit wird ein Roadmap-basierter Planer entwickelt, der in einer dreidimensionalen Umgebung unter Einfluss eines uniformen Windsfelds einen Pfad finden kann. Der Planer nutzt dabei für die horizontalen Pfadanteile eine parametrische Beschreibung von Dubins-Pfaden, die mittels Trochoidsegmenten den Einfluss des Winds abbilden. Für die vertikalen Pfadanteile wird ein parametrischer Doppelintegrator verwendet, der sich unterscheidende Ober- und Untergrenzen berücksichtigen kann. Aufgrund der Parametrisierung können die beiden Teile einfach miteinander kombiniert werden. In ersten Untersuchungen wird festgestellt, dass mit einem ausreichend guten Regler kürzere und schnellere Wege gefunden werden. Zum Teil sind diese Wege durch neue direkte Verbindungen erheblich kürzer im Vergleich zu ohne Wind geplanten Pfaden