Prediction of force coefficients for labyrinth seals

The development of a linear model for the prediction of labyrinth seal forces and on its comparison to available stiffness data is presented. A discussion of the relevance of fluid damping forces and the preliminary stages of a program to obtain data on these forces are examined. Fluid-dynamic forces arising from nonuniform pressure patterns in labyrinth seal glands are known to be potentially destablizing in high power turbomachinery. A well documented case in point is that of the space Shuttle Main Engine turbopumps. Seal forces are also an important factor for the stability of shrouded turbines, acting in that case in conjunction with the effects of blade-tip clearance variations

Dynamic SLA Negotiation in Autonomic Federated Environments

Abstract. Federated computing environments offer requestors the ability to dynamically invoke services offered by collaborating providers in the virtual service network. Without an efficient resource management that includes Dynamic SLA Negotiation, however, the assignment of providers to customer’s requests cannot be optimized and cannot offer high reliability without relevant SLA guarantees. We propose a new SLA-based SERViceable Metacomputing Environment (SERVME) capable of matching providers based on QoS requirements and performing autonomic provisioning and deprovisioning of services according to dynamic requestor needs. This paper presents the SLA negotiation process that includes on-demand provisioning and uses an object-oriented SLA model for large-scale service-oriented systems supported by SERVME. An initial reference implementation in the SORCER environment is also described

Influence of temperature on dynamics of birefringence switching in photochromic nematic phase

We present results of dynamic and fast switching of birefringence in a photochromic liquid-crystalline system as a function of the sample temperature. The system consists of photochromic molecules of 4-heptyl-4-methoxyazobenzene showing a liquid-crystalline nematic state close to room temperature. An experiment of dynamic birefringence switching was done in optical Kerr-effect set-up, where for the sample excitation, a picosecond-pulsed laser was used. Measurements were done for different temperatures of the sample in the liquid-crystalline nematic phase. We have proposed a mathematical model of dynamic, fast, and fully reversible birefringence changes. Theoretical estimations and experimental results have shown very good agreement. (C) 2011 American Institute of Physics. [doi:10.1063/1.3665123

The Genetic and Environmental Sources of Resemblance Between Normative Personality and Personality Disorder Traits

Recent work has suggested a high level of congruence between normative personality, most typically represented by the big five factors, and abnormal personality traits. In 2,293 Norwegian adult twins ascertained from a population-based registry, the authors evaluated the degree of sharing of genetic and environmental influences on normative personality, assessed by the Big Five Inventory (BFI), and personality disorder traits (PDTs), assessed by the Personality Inventory for DSM-S-Norwegian Brief Form (PID-5NBF). For four of the five BFI dimensions, the strongest genetic correlation was observed with the expected PID-5-NBF dimension (e.g., neuroticism with negative affectivity [+], conscientiousness with disinhibition [-]). However, neuroticism, conscientiousness, and agreeableness had substantial genetic correlations with other PID-S-NBF dimensions (e.g., neuroticism with compulsivity [+], agreeableness with detachment [-]). Openness had no substantial genetic correlations with any PID-5-NBF dimension. The proportion of genetic risk factors shared in aggregate between the BFI traits and the PID-5-NBF dimensions was quite high for conscientiousness and neuroticism, relatively robust for extraversion and agreeableness, but quite low for openness. Of the six PID-S-NBF dimensions, three (negative affectivity, detachment, and disinhibition) shared, in aggregate, most of their genetic risk factors with normative personality traits. Genetic factors underlying psychoticism, antagonism, and compulsivity were shared to a lesser extent, suggesting that they are influenced by etiological factors not well indexed by the BFI

Pulsed laser induced switching of birefringence in nematic phase of photochromic molecules

Fast and dynamic switching of liquid-crystalline photochromic system birefringence induced by pulsed laser has been observed. The system consisted of photochromic molecules of 4-heptyl-4-methoxyazobenzene showing liquid-crystalline nematic state close to the room temperature. Experiment of dynamic birefringence switching was done in optical Kerr effect (OKE) set-up, where for the sample excitation picosecond pulsed laser was used. Simultaneously, He-Ne laser was served as a probe beam source. Measurements were done for different voltages applied to the sample. Rise time constant was in the range of microseconds. Full reversibility of the OKE signal was observed. (C) 2011 American Institute of Physics. [doi:10.1063/1.3559613

Anonymity and its Prospects in the Digital World

"This work­ing paper traces the changes under­gone by anonymity - and by the dis­courses sur­rounding it - in liberal Western societies. The author asks whether the current politi­cization of the issue is likely to have any impact on the gra­dual dis­appearance of oppor­tunities for anonymity that we are currently witnes­sing and argues that anonymity is an ambi­valent but critical feature of the demo­cratic public sphere. The argu­ment proceeds in three stages. It begins with a number of concep­tual ob­ser­vations on anonymity. From these, a heuristic frame­work emerges with which the changes in anony­mous communi­cation, and in the role this communi­cation plays in society, can be described. The author then analyses the extent to which options for anonymity have been affected by the rev­olution in infor­mation and communi­cation techno­logies and concludes by con­sidering how anonymity is framed in public dis­course and what impacts this has." (author's abstract)"Das Working Paper unter­sucht die Ver­änderungen von Anonymität und den Diskursen über Anonymität in liberalen west­lichen Gesell­schaften. Der Autor fragt, in­wiefern die gegen­wärtige Politi­sierung des Themas einen Einfluss auf das gra­duelle Ver­schwinden der Möglich­keiten anonymer Kom­munikation haben wird und welche Be­deutung Anonymität für die demo­kratische Öffen­tlich­keit hat. Die Analyse voll­zieht sich in drei Schritten: Zunächst wird konzep­tuell ge­klärt, was Anonymität ist und darauf auf­bauend ein heur­istisches Instru­ment ent­wickelt mittels dessen sich die Ver­änderung anonymer Kom­muni­kations­mög­lich­keiten in der Gesell­schaft be­schreiben lassen. Im zweiten Schritt wird dieses Instru­ment zur An­wendung gebracht, um die sich wandelnden Möglich­keiten anonymer Komm­uni­kation im digitalen Struktur­wandel zu porträtieren. Der dritte Teil des Papiers fragt schließ­lich nach der Art und Weise, wie Anonymität im öffent­lichen Diskurs politi­siert wird - und sucht die Erfolgs­aus­sichten ab­zu­schätzen, die diese Thema­tisierung hat, der Ent­wicklung zu be­gegnen oder sie gar um­zu­kehren." (Autorenreferat

Solar Cooling in the Ecuadorian Contexts

Ecuador presents four specific climates, Coast, Andes, Amazonia and Galapagos. This paper discusses the interest of solar cooling systems implementation in each case. The hot and humid climate ofthe Coast and Amazonia is similar to other tropical and equatorial climates where these techniques have been tested and described widely. Besides, the Andean climate of Quito (2800 meters above the sea level) and the very constrained conditions of Galapagos Islands are not yet well documented. This paper sets some guidelines forfurthest research in the Ecuadorian contexts.Facultad de Arquitectura y Urbanismo (FAU

A typology of community flood resilience

Flood risk is increasing worldwide and there is a growing need to better understand the co-benefits of investments in disaster resilience. Utilizing a multinational community flood resilience dataset, this paper takes a systems approach to understanding community-level flood resilience. Using a cluster analysis and bivariate correlation methods, we develop a typology of community flood resilience capacity based on community characteristics and five capitals (human, financial, natural, physical, and social). Our results reinforce the importance of context-specific policymaking and give recommendations of four distinct clusters to investigate the relationship between flood resilience and prevailing development conditions. We especially find that communities with higher interactions between their capital capacities tend to have higher flood resilience levels. Additionally, there are indications that stronger interactions between community capacities can help to induce multiple co-benefits when investing in disaster resilience. Our results also have important policy implications on the individual community level. For example, based on our results, we suggest that communities with lower flood resilience capacities and interactions can best build resilience on leveraging their relatively higher human capital capacities to strengthen the financial and social capitals. Negative effects might happen for urban communities when co-benefits of natural and physical capital are not fully integrated. The highest flood resilience capacity is found in communities with a well-balanced household income distribution which is likely a contributing factor to the importance of financial capital for this cluster. Our results emphasize the importance of an integrative approach to management when implementing systematic flood disaster resilience metrics and development measures

Solar Cooling in the Ecuadorian Contexts

Ecuador presents four specific climates, Coast, Andes, Amazonia and Galapagos. This paper discusses the interest of solar cooling systems implementation in each case. The hot and humid climate ofthe Coast and Amazonia is similar to other tropical and equatorial climates where these techniques have been tested and described widely. Besides, the Andean climate of Quito (2800 meters above the sea level) and the very constrained conditions of Galapagos Islands are not yet well documented. This paper sets some guidelines forfurthest research in the Ecuadorian contexts.Facultad de Arquitectura y Urbanismo (FAU