Comparison of ALE and SPH Simulations of Vertical Drop Tests of a Composite Fuselage Section into Water

Simulation of multi-terrain impact has been identified as an important research area for improved prediction of rotorcraft crashworthiness within the NASA Subsonic Rotary Wing Aeronautics Program on Rotorcraft Crashworthiness. As part of this effort, two vertical drop tests were conducted of a 5-ft-diameter composite fuselage section into water. For the first test, the fuselage section was impacted in a baseline configuration without energy absorbers. For the second test, the fuselage section was retrofitted with a composite honeycomb energy absorber. Both tests were conducted at a nominal velocity of 25-ft/s. A detailed finite element model was developed to represent each test article and water impact was simulated using both Arbitrary Lagrangian Eulerian (ALE) and Smooth Particle Hydrodynamics (SPH) approaches in LS-DYNA, a nonlinear, explicit transient dynamic finite element code. Analytical predictions were correlated with experimental data for both test configurations. In addition, studies were performed to evaluate the influence of mesh density on test-analysis correlation

Vertical Drop Testing and Analysis of the WASP Helicopter Skid Gear

Human occupant modeling and injury risk assessment have been identified as areas of research for improved prediction of rotorcraft crashworthiness within the NASA Aeronautics Program's Subsonic Rotary Wing Project. As part of this effort, an experimental program was conducted to assess the impact performance of a skid gear for use on the WASP kit-built helicopter, which is marketed by HeloWerks, Inc. of Hampton, Virginia. Test data from a drop test at an impact velocity of 8.4 feet-per-second were used to assess a finite element model of the skid gear test article. This assessment included human occupant analytic models developed for execution in LS-DYNA. The test article consisted of an aluminum skid gear mounted beneath a steel plate. A seating platform was attached to the upper surface of the steel plate, and two 95th percentile Hybrid III male Aerospace Anthropomorphic Test Devices (ATDs) were seated on the platform and secured using a four-point restraint system. The goal of the test-analysis correlation is to further the understanding of LS-DYNA ATD occupant models and responses in the vertical (or spinal) direction. By correlating human occupant experimental test data for a purely vertical impact with the LS-DYNA occupant responses, improved confidence in the use of these tools and better understanding of the limitations of the automotive-based occupant models for aerospace application can begin to be developed

Overview of the NASA Subsonic Rotary Wing Aeronautics Research Program in Rotorcraft Crashworthiness

This paper provides an overview of rotorcraft crashworthiness research being conducted at NASA Langley Research Center under sponsorship of the Subsonic Rotary Wing (SRW) Aeronautics Program. The research is focused in two areas: development of an externally deployable energy attenuating concept and improved prediction of rotorcraft crashworthiness. The deployable energy absorber (DEA) is a composite honeycomb structure, with a unique flexible hinge design that allows the honeycomb to be packaged and remain flat until needed for deployment. The capabilities of the DEA have been demonstrated through component crush tests and vertical drop tests of a retrofitted fuselage section onto different surfaces or terrain. The research on improved prediction of rotorcraft crashworthiness is focused in several areas including simulating occupant responses and injury risk assessment, predicting multi-terrain impact, and utilizing probabilistic analysis methods. A final task is to perform a system-integrated simulation of a full-scale helicopter crash test onto a rigid surface. A brief description of each research task is provided along with a summary of recent accomplishments

The Passo Fundo cohort study : design of a population-based observational study of women in premenopause, menopausal transition, and postmenopause

Background: The Passo Fundo Cohort Study (PFS) is a population-based longitudinal observational study of pre-, peri-, and postmenopausal women that has been ongoing since 1995 in Passo Fundo, a city in southern Brazil. This paper describes the rationale and design of the PFS and summarizes objectives and procedures that have been updated during follow-up. Methods/Design: Women in the PFS have been followed for a variety of diseases that are frequent in menopause. Sampling was conducted in 154 randomly selected census divisions (geographical subdivisions of the city as defined by the Brazilian Institute of Geography and Statistics). One block in each census division was chosen by lot and two women were randomly selected for interview in each block. The first cycle, conducted between 1995 and 1997, included a representative sample of 298 women aged 35 to 55 years. In the second cycle, conducted between 2001 and 2002, additional participants were enrolled based on the same sampling strategy used in 1995, for a final sample of 358 women In 2010, a third follow-up was initiated, when all 358 participants or their relatives were located. Participants completed a standardized questionnaire on demographic and socioeconomic characteristics. They also answered questions about lifestyle, medical and reproductive characteristics, sexual life, hormone therapy and mental aspects by using validated instruments. Physical activity was assessed and anthropometric measurements, blood sampling and pelvic ultrasound examination were performed. In the third cycle, bone mineral density by dual-energy X-ray absorptiometry and abdominal fat and coronary artery calcium score by computed tomography were also determined. Discussion: The study findings provide relevant information to evaluate the association between menopausal status, female aging and the risk of cardiovascular diseases, and bone health aspects in a representative sample of women from southern Brazil

The Passo Fundo cohort study : design of a population-based observational study of women in premenopause, menopausal transition, and postmenopause

Background: The Passo Fundo Cohort Study (PFS) is a population-based longitudinal observational study of pre-, peri-, and postmenopausal women that has been ongoing since 1995 in Passo Fundo, a city in southern Brazil. This paper describes the rationale and design of the PFS and summarizes objectives and procedures that have been updated during follow-up. Methods/Design: Women in the PFS have been followed for a variety of diseases that are frequent in menopause. Sampling was conducted in 154 randomly selected census divisions (geographical subdivisions of the city as defined by the Brazilian Institute of Geography and Statistics). One block in each census division was chosen by lot and two women were randomly selected for interview in each block. The first cycle, conducted between 1995 and 1997, included a representative sample of 298 women aged 35 to 55 years. In the second cycle, conducted between 2001 and 2002, additional participants were enrolled based on the same sampling strategy used in 1995, for a final sample of 358 women In 2010, a third follow-up was initiated, when all 358 participants or their relatives were located. Participants completed a standardized questionnaire on demographic and socioeconomic characteristics. They also answered questions about lifestyle, medical and reproductive characteristics, sexual life, hormone therapy and mental aspects by using validated instruments. Physical activity was assessed and anthropometric measurements, blood sampling and pelvic ultrasound examination were performed. In the third cycle, bone mineral density by dual-energy X-ray absorptiometry and abdominal fat and coronary artery calcium score by computed tomography were also determined. Discussion: The study findings provide relevant information to evaluate the association between menopausal status, female aging and the risk of cardiovascular diseases, and bone health aspects in a representative sample of women from southern Brazil

Molecular characterisation of the STRUBBELIG-RECEPTOR FAMILY of genes encoding putative leucine-rich repeat receptor-like kinases in Arabidopsis thaliana

BACKGROUND: Receptor-like kinases are a prominent class of surface receptors that regulate many aspects of the plant life cycle. Despite recent advances the function of most receptor-like kinases remains elusive. Therefore, it is paramount to investigate these receptors. The task is complicated by the fact that receptor-like kinases belong to a large monophyletic family with many sub-clades. In general, functional analysis of gene family members by reverse genetics is often obscured by several issues, such as redundancy, subtle or difficult to detect phenotypes in mutants, or by decision problems regarding suitable biological and biochemical assays. Therefore, in many cases additional strategies have to be employed to allow inference of hypotheses regarding gene function. RESULTS: We approached the function of genes encoding the nine-member STRUBBELIG-RECEPTOR FAMILY (SRF) class of putative leucine-rich repeat receptor-like kinases. Sequence comparisons show overall conservation but also divergence in predicted functional domains among SRF proteins. Interestingly, SRF1 undergoes differential splicing. As a result, SRF1 is predicted to exist in a standard receptor configuration and in a membrane-anchored receptor-like version that lacks most of the intracellular domain. Furthermore, SRF1 is characterised by a high degree of polymorphism between the Ler and Col accessions. Two independent T-DNA-based srf4 mutants showed smaller leaves while 35S::SRF4 plants displayed enlarged leaves. This is in addition to the strubbelig phenotype which has been described before. Additional single and several key double mutant combinations did not reveal obvious mutant phenotypes. Ectopic expression of several SRF genes, using the 35S promoter, resulted in male sterility. To gain possible insights into SRF gene function we employed a computational analysis of publicly available microarray data. We performed global expression profiling, coexpression analysis, and an analysis of the enrichment of gene ontology terms among coexpressed genes. The bioinformatic analyses raise the possibility that some SRF genes affect different aspects of cell wall biology. The results also indicate that redundancy is a minor aspect of the SRF family. CONCLUSION: The results provide evidence that SRF4 is a positive regulator of leaf size. In addition, they suggest that the SRF family is characterised by functional diversity and that some SRF genes may function in cell wall biology. They also indicate that complementing reverse genetics with bioinformatical data mining of genome-wide expression data aids in inferring hypotheses on possible functions for members of a gene family

New digital divergence

Meeting: 6th International Conference on Information Technology and Applications (ICITA 2009),9 - 12 November 2009, Hanoi, VNThe paper summarizes the rise of digital technology, focusing on mobile phones and their impact on developing countries. For the first time the mass of the developing world, including the poor, have access to a technology that they can afford, know how to use and that has great potential to affect their poverty outcomes. The authors raise questions about how the “poor-people's technology” of the mobile phone can play a central role in information and communications technologies for development.À la fin du XXe siècle, on a assisté à la commercialisation d’Internet à titre de grande technologie transformatrice ayant d’importantes répercussions sur la société et sur l’économie, surtout dans les pays industrialisés. Au XXIe siècle, une nouvelle transformation se produit du fait de l’omniprésence du téléphone mobile. Les auteurs font ressortir deux nouvelles tendances. En premier lieu, ils mentionnent la croissance divergente de la téléphonie mobile et d’Internet, en particulier dans les pays en développement. Quant à la deuxième tendance, il s’agit de l’essor de l’utilisation partagée de matériel informatique et de logiciels. Faisant état de ces deux tendances et de plusieurs autres, les auteurs se demandent comment la technologie des pauvres, soit celle du téléphone mobile, peut jouer un rôle crucial parmi les technologies de l’information et de la communication au service du développement

”Whose bread I eat, his song I sing”? Technology assessment and its clients

Weimer und Vining (1999) unterscheiden drei Rollen, die WissenschafterInnen in Politikberatung einnehmen können: den objective technician, den issue advocate und den client's advocate. Dieser Beitrag widmet sich jener Rolle, die in der gegenwärtigen Diskussion kaum reflektiert wird, aber dennoch für die Normativität von Technikfolgenabschätzung (TA) relevant ist: dem client’s advocate. Basierend auf Daten aus einer empirischen internen Erhebung von Praxen, Konstellationen und Paradigmen der Politikberatung am österreichischen Institut für Technikfolgen-Abschätzung (ITA), stellen wir (1) das in den Projekten des Instituts realisierte Portfolio an Geldgebern bzw. Auftraggebern dar, setzen es (2) in Bezug zu den in den Projekten des ITA angesprochenen Issues und zu Ergebnissen aus vier projektspezifischen Fallstudien und formulieren (3) offene Fragen an die TA-Praxis und TA-Community.Weimer and Vining (1999) discern three roles for scientific policy advisers: the objective technician, the issue advocate, and the client’s advocate. This contribution focuses on the latter – a role that is rarely reflected upon in current discussions about technology assessment (TA) practice. Based on empirical data on the practices, constellations, and paradigms prevalent in policy advice activities at the Austrian Institute of Technology Assessment (ITA), we (1) present the portfolio and characteristics of the institute’s clients, (2) relate these to the issues addressed in the institute’s projects and to four project-specific case studies, and (3) present open questions to the practice and community of TA pertaining to its relation to its clients

Rapid succession drives spring community dynamics of small protists at Helgoland Roads, North Sea

The dynamics of diatoms and dinoflagellates have been monitored for many decades at the Helgoland Roads Long-Term Ecological Research site and are relatively well understood. In contrast, small-sized eukaryotic microbes and their community changes are still much more elusive, mainly due to their small size and uniform morphology, which makes them difficult to identify microscopically. By using next-generation sequencing, we wanted to shed light on the Helgoland planktonic community dynamics, including nano- and picoplankton, during a spring bloom. We took samples from March to May 2016 and sequenced the V4 region of the 18S rDNA. Our results showed that mixotrophic and heterotrophic taxa were more abundant than autotrophic diatoms. Dinoflagellates dominated the sequence assemblage, and several small-sized eukaryotic microbes like Haptophyta, Choanoflagellata, Marine Stramenopiles and Syndiniales were identified. A diverse background community including taxa from all size classes was present during the whole sampling period. Five phases with several communities were distinguished. The fastest changes in community composition took place in phase 3, while the communities from phases 1 to 5 were more similar to each other despite contrasting environmental conditions. Synergy effects of next-generation sequencing and traditional methods may be exploited in future long-term observations

Reference Power Vectors for the Optical LEO Downlink Channel

The synthesis of numerical power vectors for optical satellite data downlinks through the atmosphere to optical ground stations is described. A set of standard time series is defined and their further application for estimation of transmission performance is shown