Profile design for wings and propellers

It has now become customary to develop profiles for wings and propellers for a given employment of the aircraft. This is possible because methods and computers are available to study an entire series of variants in comparatively short time. The basic viewpoints for profile design are presented. It is shown that laminarization has its advantages in almost all cases, including the design of a turbine blade and the design of the profile of an airliner. The requirements which profiles have to satisfy are discussed along with the possibilities for increasing lift on profiles

Performing multi-religious ritual in Southern Thailand

In this article, I follow two ethnographic examples of multi-religious ritual in Southern Thailand in order to show how bodily expressions of identity constitute a privileged terrain for understanding the dramatic performances in which social hierarchies and normative orders are expressed and identities negotiated. Bodily expressions, such as physical movements of the body, gestures, chanting, etc. comprise part of the cultural memory that is inscribed in a participants’ body and communicated in the context of a performance. I use the case of the exchange of prayer gestures and chanting in the “ritual of two religions” annually hold in Tamot, Patthalung and the case of a Muslima who wants to cure her child in a Buddhist temple in Songkhla to illustrate what Hayden has called the simultaneous presence of antagonism and tolerance in multi-religious ritual spaces. Thus, rather than a remainder of solidarity and cohesion, I regard the exchange of bodily expressions as transgressions in a life world where religions are increasingly separated. Following Lambek’s notion of polyphony, I maintain that people in Southern Thailand navigate between the conflicting claims that traditional and orthodox beliefs make upon them without making a final decision for either system

The effect of temperature on generic stable periodic structures in the parameter space of dissipative relativistic standard map

In this work, we have characterized changes in the dynamics of a two-dimensional relativistic standard map in the presence of dissipation and specially when it is submitted to thermal effects modeled by a Gaussian noise reservoir. By the addition of thermal noise in the dissipative relativistic standard map (DRSM) it is possible to suppress typical stable periodic structures (SPSs) embedded in the chaotic domains of parameter space for large enough temperature strengths. Smaller SPSs are first affected by thermal effects, starting from their borders, as a function of temperature. To estimate the necessary temperature strength capable to destroy those SPSs we use the largest Lyapunov exponent to obtain the critical temperature ($T_C$) diagrams. For critical temperatures the chaotic behavior takes place with the suppression of periodic motion, although, the temperature strengths considered in this work are not so large to convert the deterministic features of the underlying system into a stochastic ones.Comment: 8 pages and 7 figures, accepted to publication in EPJ

Konfessionelle Koexistenz in Südthailand:Ritueller Austausch, Transformation und die Reproduktion des Sozialen in Südthailand

In Südthailand leben Muslime und Buddhisten seit der Ayuthhaya-Periode in engen nachbarschaftlichen Beziehungen, in denen lokale Mechanismen der Konfliktvermeidung entwickelt werden, die eine friedvolle Koexistenz ermöglichen. Vor dem Hintergrund gewalttätiger Konflikte in Südthailand wird die lokale Geschichte der konfessionellen Beziehungen Südthailands, ihre Vergleichbarkeit und Transformation sowie ihre Einlagerung in Prozesse nationaler Integration und kultureller Globalisierung in einer Fallstudie exemplarisch untersucht. Besonders interessant ist die Frage der Vitalität bzw. Auflösung der geteilten kosmologischen Werte und Normen

Psychometric evaluation of the German version of the dietary fat and free sugar-short questionnaire

Background: The Dietary Fat and Free Sugar-Short Questionnaire (DFS) is a cost- and time-efficient self-report screening instrument to estimate dietary intake of saturated fat and free sugar. To date, only the English version has been psychometrically evaluated. We assessed the psychometric characteristics of the German version of the DFS in individuals with normal weight, overweight, and obesity. Method: Sixty-five adult participants completed a German translation of the DFS and a validated food frequency questionnaire (FFQ). We correlated participants’ percentage of energy intake from saturated fat and free sugar from the FFQ with the DFS scores. To establish test-retest reliability, participants completed the DFS a second time. To investigate convergent validity, we correlated participants’ DFS scores with self-reported eating behavior and sensitivity to reward. Results: DFS scores correlated with percentage of energy from free sugar (rs = 0.443) and saturated fatty acids (rs =0.258) but not with non-target nutrients. The correlation between DFS scores and percentage energy from free sugar was not moderated by body mass index (BMI), whereas the correlation with percentage energy from saturated fat slightly decreased with BMI. Intra-class correlation as an indicator of test-retest reliability was 0.801. DFS scores correlated significantly with restraint of eating behavior (rs = –0.380) and feelings of hunger (rs = 0.275). Correlations of the DFS score with disinhibited eating and sensitivity to rewards failed to be significant. Conclusion: Our data indicate that the German version of the DFS might be a psychometrically sound self-report instrument to estimate saturated fat and free sugar intake of German adults

Aggregation of chemotactic organisms in a differential flow

We study the effect of advection on the aggregation and pattern formation in chemotactic systems described by Keller-Segel type models. The evolution of small perturbations is studied analytically in the linear regime complemented by numerical simulations. We show that a uniform differential flow can significantly alter the spatial structure and dynamics of the chemotactic system. The flow leads to the formation of anisotropic aggregates that move following the direction of the flow, even when the chemotactic organisms are not directly advected by the flow. Sufficiently strong advection can stop the aggregation and coarsening process that is then restricted to the direction perpendicular to the flow

General Habit Propensity Relates to the Sensation Seeking Subdomain of Impulsivity But Not Obesity

According to dual-system theory, instrumental learning and performance depend on the balance between goal-directed and habitual action control. Overreliance on habits has been argued to characterize clinical conditions such as drug addiction or obsessivecompulsive disorder as well as obesity and excessive impulsivity. A tendency towards habitual action control in obesity has already been indicated in the food domain. However, impairments might not be restricted to eating behavior. This has been suggested by domain-general obesity-associated disturbances in executive function as well as alterations in corticostriatal circuits underlying the goal-directed and habitual systems. In this study we examined the balance of goal-directed and habitual action control in a sample of normal-weight, overweight, and obese participants (n=105) using the slips-of-action test in a non-food context. We tested for continuous or group-based associations between body weight status (BMI) and the devaluation sensitivity index (DSI), a parameter representing the balance of the goal-directed and habitual systems in action control. As personality differences in the domain of impulsivity might affect this relationship, we also examined whether the interaction between BMI and self-reported impulsivity, based on the UPPS Impulsive Behavior Scale, was related to the DSI. In addition to that, we tested for direct, i.e., weight status independent, relationships between UPPS subdomains of impulsivity and the DSI. We failed to find evidence for a relationship between weight status and sensitivity to devaluation as indexed by the DSI. However, independent of weight status, we observed lower sensitivity to devaluation in sensation seekers, a subtype of impulsivity. To conclude, behavioral flexibility in the sense of disturbances in the balance between the habitual and goal-directed systems seems to be unaffected by weight status in a non-food context. Consequently, stimuli and behavior might not be generally excessively linked in overweight or obesity. However, according to ceiling effects we cannot rule out subtle effects the paradigm was not able to disentangle. Further, future studies are needed to clarify the role of specific subtypes of obesity (e.g., food addiction). The indicated habit propensity in sensation seekers may account for previous reports of weak avoidance behavior and risky decision making

From brain to earth and climate systems: Small-world interaction networks or not?

We consider recent reports on small-world topologies of interaction networks derived from the dynamics of spatially extended systems that are investigated in diverse scientific fields such as neurosciences, geophysics, or meteorology. With numerical simulations that mimic typical experimental situations we have identified an important constraint when characterizing such networks: indications of a small-world topology can be expected solely due to the spatial sampling of the system along with commonly used time series analysis based approaches to network characterization

Reduction of profile drag by blowing out through peg holes in areas of streamline separation bubbles

Streamline separation bubbles on aircraft profiles and fuselages were investigated. The additional drag was examined in relation to increased angle of incidence and unusually high wall sheer stress. A reduction of the separation bubble and a decrease in drag is obtained with pneumatic turbulators that blow ram air out of 0.6mm pilot tubes at a distance of 16 mm. The pneumatic models are implemented at various positions and are found to be effective after the position of separation