Systems and certification issues for civil transport aircraft flow control systems

This article is placed here with permission from the Royal Aeronautical Society - Copyright @ 2009 Royal Aeronautical SocietyThe use of flow control (FC) technology on civil transport aircraft is seen as a potential means of providing a step change in aerodynamic performance in the 2020 time frame. There has been extensive research into the flow physics associated with FC. This paper focuses on developing an understanding of the costs and design drivers associated with the systems needed and certification. The research method adopted is based on three research strands: 1. Study of the historical development of other disruptive technologies for civil transport aircraft, 2. Analysis of the impact of legal and commercial requirements, and 3. Technological foresight based on technology trends for aircraft currently under development. Fly by wire and composite materials are identified as two historical examples of successful implementation of disruptive new technology. Both took decades to develop, and were initially developed for military markets. The most widely studied technology similar to FC is identified as laminar flow control. Despite more than six decades of research and arguably successful operational demonstration in the 1990s this has not been successfully transitioned to commercial products. Significant future challenges are identified in cost effective provision of the additional systems required for environmental protection and in service monitoring of FC systems particularly where multiple distributed actuators are envisaged. FC generated noise is also seen as a significant challenge. Additional complexity introduced by FC systems must also be balanced by the commercial imperative of dispatch reliability, which may impose more stringent constraints than legal (certification) requirements. It is proposed that a key driver for future successful application of FC is the likely availability of significant electrical power generation on 787 aircraft forwards. This increases the competitiveness of electrically driven FC systems compared with those using engine bleed air. At the current rate of progress it is unlikely FC will make a contribution to the next generation of single-aisle aircraft due to enter service in 2015. In the longer term, there needs to be significant movement across a broad range of systems technologies before the aerodynamic benefits of FC can be exploited.This work is supported by the EU FP6 AVERT (AerodynamicValidation of Emissions Reducing Technologies) project

THE ROLE OF THE FOREIGN CAPITAL IN THE INTEGRATION PROCESS OF REPUBLIC OF MACEDONIA

Foreign capital has significant role for every national economy, regardless of its level of development. For the developed countries it is necessary to support sustainable development. For the developing countries, it’s used to increase accumulation and rate of investments to create conditions for more intensive economic growth. For the transition countries, it’s useful to carry out the reforms and cross to open economy, to cross the past long term problems and to create conditions for stable and continuous growth of GDP, as well as integration in world economy. In accordance with low level of accumulation and rate of development, Macedonia as a transition country has a very big need for foreign capital. When we talk about the foreign capital and its need and significance for the Macedonian economy, on the first place we have in mind the foreign direct investments, that result by the great number of externalizes produced by FDI for the national economy. But, also credit and loan as traditional form of transfer of capital in international economic relations, it will be useful for the growth only if it is at the reasonable level (in regard of the national external debt) from one side, and if its use in the development of a certain economy is efficient, from other side.Development of the national economy; Foreign capital; Credits and loans; Foreign direct investments.

Three-dimensional foot shape analysis in children : a pilot analysis using three-dimensional shape descriptors

Existing clinical measures to describe foot morphology are limited in that they are commonly two-dimensional, low in resolution and accuracy, and do not accurately represent the multi-planar and complex changes during development across childhood. Using three-dimensional (3D) scanner technology provides the opportunity to understand more about morphological changes throughout childhood with higher resolution and potentially more relevant 3D shape measures. This is important to advance the prevailing arguments about the typical development of children's feet and inform the development of appropriate clinical measures. 3D shape descriptors derived from 3D scanning can be used to quantify changes in shape at each point of the 3D surface. The aim of this study was to determine whether 3D shape descriptors derived from 3D scanning data can identify differences in foot morphology between children of different ages. Fifteen children were recruited from three age groups (2, 5, and 7 years of age). Both feet were scanned in bipedal stance, using the Artec Eva (Artec Group, Luxembourg, Luxembourg) hand-held scanner. Three dimensional shape descriptors were extracted from the 3D scans of the right foot, to create histograms for each age group and heat maps of representative participants for comparison. There were changes to the dorsal, medial and lateral surfaces of the feet with age. The surfaces became less round along with an increase in indented areas. This is supported by the heat maps which demonstrated that the surfaces of the anatomical landmarks (e.g. the malleoli and navicular tuberosity) became more rounded and protruding, with indented surfaces appearing around these landmarks. On the plantar surface, the concavity of the midfoot was evident and this concavity extended into the midfoot from the medial aspect as age increased. The findings of this study indicated that with increasing age the foot becomes thinner in 3D, with bony architecture emerging, and the medial longitudinal arch (MLA) increases in area and concavity. Three-dimensional shape descriptors have shown good potential for locating and quantifying changes in foot structure across childhood. Three-dimensional shape descriptor data will be beneficial for understanding more about foot development and quantifying changes over time

Regulation of vacuolar H+-ATPase activity by the Cdc42 effector Ste20 in Saccharomyces cerevisiae

In the budding yeast Saccharomyces cerevisiae, the Cdc42 effector Ste20 plays a crucial role in the regulation of filamentous growth, a response to nutrient limitation. Using the split-ubiquitin technique, we found that Ste20 forms a complex with Vma13, an important regulatory subunit of vacuolar H(+)-ATPase (V-ATPase). This protein-protein interaction was confirmed by a pulldown assay and coimmunoprecipitation. We also demonstrate that Ste20 associates with vacuolar membranes and that Ste20 stimulates V-ATPase activity in isolated vacuolar membranes. This activation requires Ste20 kinase activity and does not depend on increased assembly of the V1 and V0 sectors of the V-ATPase, which is a major regulatory mechanism. Furthermore, loss of V-ATPase activity leads to a strong increase in invasive growth, possibly because these cells fail to store and mobilize nutrients efficiently in the vacuole in the absence of the vacuolar proton gradient. In contrast to the wild type, which grows in rather small, isolated colonies on solid medium during filamentation, hyperinvasive vma mutants form much bigger aggregates in which a large number of cells are tightly clustered together. Genetic data suggest that Ste20 and the protein kinase A catalytic subunit Tpk2 are both activated in the vma13Δ strain. We propose that during filamentous growth, Ste20 stimulates V-ATPase activity. This would sustain nutrient mobilization from vacuolar stores, which is beneficial for filamentous growth.The project was supported by Deutsche Forschungsgemeinschaft grant HO 2098/3 to T.H. and NIH grant R01 GM50322 to P.M.K

Professional appraisal of online information about children’s footwear measurement and fit : readability, usability and quality

Parents increasingly use the internet to seek health information, share information and for purchasing textiles and footwear. This shift in footwear purchasing habits raises concern about how (and if) parents are getting their children's feet measured, and what support strategies are in place to support the fit of footwear. In response to this, some companies and healthcare organisations have developed resources to support home measurement of foot size, and link these measures to footwear selection, measurement and fitting. The aim of this research was to undertake an appraisal of web-based resources about measurement and fit of children's footwear, focussing specifically on readability, usability and quality. Search terms relating to children's foot measurement were compiled and online searching was undertaken. Search results were saved and screened for relevance. Existing resources were categorised based on their source e.g. a footwear company or a health website. The 15 most commonly identified resources were reviewed by a professional panel for readability, content, usability and validity. One researcher also assessed the accessibility and reading ease of the resources. Online resources were predominantly from commercial footwear companies (54%). Health information sources from professional bodies made up 4.2% of the resources identified. The top 15 resources had appropriate reading ease scores for parents (SMOG Index 4.3-8.2). Accessibility scores (the product of the number of times it appeared in search results and its ranking in the results) were highest for commercial footwear companies. The panel scores for readability ranged from 2.7 to 9 out of 10, with a similar range for content, usability and validity. Information for parents seeking to purchase footwear for their children is readily available online but this was largely dominated by commercial footwear companies. The quality and usability of this information is of a moderate standard; notable improvements could be made to the validity of the task the child is asked to undertake and the measures being taken. Improvements in these resources would improve the data input to the selection of footwear and therefore have a beneficial impact on footwear fit in children. [Abstract copyright: © The Author(s). 2020.

Symptomatic pes planus in children : a synthesis of allied health professional practices

This study sought to explore professional perspectives on the assessment and management of symptomatic pes planus in children. Data was collected from three professional groups (podiatrists, physiotherapists, and orthotists) with experience of managing foot problems in children. The survey was undertaken in the United Kingdom via a self-administered, online survey. Data was captured over a four-month period in 2018. Fifty-five health professionals completed the survey and the results highlighted that assessment techniques varied between professions, with standing tip-toe and joint range of motion being the most common. Treatment options for children were diverse and professionals were adopting different strategies as their first line intervention. All professions used orthoses. There were inconsistencies in how the health professionals assessed children presenting with foot symptoms, variation in how the condition was managed and differences in outcome measurement. These findings might be explained by the lack of robust evidence and suggests that more effort is needed to harmonise assessment and treatment approaches between professions. Addressing discrepancies in practice could help prioritise professional roles in this area, and better support the management of children with foot pain. [Abstract copyright: © The Author(s). 2020.

Thin electron-scale layers at the magnetopause

We use data from the four Cluster satellites to examine the microphysics of a thin electron-scale layer discovered on the magnetospheric side of the magnetopause. Here the ion and electron motions are decoupled in a layer about 20 km (a few electron scales) wide, including currents and strong electric fields. In this layer the electrons are E x B drifting with the ions as a background, and the region can be described by Hall MHD physics. A unique identification of the source of the thin layer is not possible, but our observations are consistent with recent simulations showing thin layers associated with the separatrix extending far away from a reconnection diffusion region

Simulationsumgebung zur Evaluation von umweltorientierten Verkehrsmanagement-Strategien

Der vorliegende Beitrag beschreibt die Problematik bei der Prognose verkehrsbedingter Schadstoff-Immissionen. Im Mittelpunkt steht die Entwicklung und der Aufbau einer Simulationsumgebung zur Evaluation von umweltorientierten Verkehrsmanagement-Strategien. Die Simulationsumgebung wird über die drei Felder Verkehr, Emission, Immission entwickelt und findet zunächst Anwendung in der Evaluation verkehrlicher Maßnahmen für die Friedberger Landstraße in Frankfurt am Main

Computational prediction of the refinement of oxide agglomerates in a physical conditioning process for molten aluminium alloy

Physically conditioning molten scrap aluminium alloys using high shear processing (HSP) was recently found to be a promising technology for purification of contaminated alloys. HSP refines the solid oxide agglomerates in molten alloys, so that they can act as sites for the nucleation of Fe-rich intermetallic phases which can subsequently be removed by the downstream de-drossing process. In this paper, a computational modelling for predicting the evolution of size of oxide clusters during HSP is presented. We used CFD to predict the macroscopic flow features of the melt, and the resultant field predictions of temperature and melt shear rate were transferred to a population balance model (PBM) as its key inputs. The PBM is a macroscopic model that formulates the microscopic agglomeration and breakage of a population of a dispersed phase. Although it has been widely used to study conventional deoxidation of liquid metal, this is the first time that PBM has been used to simulate the melt conditioning process within a rotor/stator HSP device. We employed a method which discretizes the continuous profile of size of the dispersed phase into a collection of discrete bins of size, to solve the governing population balance equation for the size of agglomerates. A finite volume method was used to solve the continuity equation, the energy equation and the momentum equation. The overall computation was implemented mainly using the FLUENT module of ANSYS. The simulations showed that there is a relatively high melt shear rate between the stator and sweeping tips of the rotor blades. This high shear rate leads directly to significant fragmentation of the initially large oxide aggregates. Because the process of agglomeration is significantly slower than the breakage processes at the beginning of HSP, the mean size of oxide clusters decreases very rapidly. As the process of agglomeration gradually balances the process of breakage, the mean size of oxide clusters converges to a steady value. The model enables formulation of the quantitative relationship between the macroscopic flow features of liquid metal and the change of size of dispersed oxide clusters, during HSP. It predicted the variation in size of the dispersed phased with operational parameters (including the geometry and, particularly, the speed of the rotor), which is of direct use to experimentalists optimising the design of the HSP device and its implementation.This research is financially supported by the EC FP7 project “High Shear Processing of Recycled Aluminium Scrap for Manufacturing High Performance Aluminium Alloys” (Grant No. 603577)

Relacions sexuals i rendiment físic: aclarint el mite de l’efecte perjudicial de mantenir relacions sexuals coitals abans de participar en activitats físiques extenuants

La nostra revisió bibliogràfica pretén presentar l’evidència científica que contradiu el mite que mantenir relacions sexuals coitals abans de realitzar alguna activitat que requereix un rendiment físic màxim és perjudicial. Encara que, en l’actualitat, aquest mite es continua difonent en alguns ambients esportius, no existeixen estudis que indiquin que mantenir relacions sexuals coitals sigui perjudicial. Prenent com a base mesuraments de paràmetres fisiològics, metabòlics i psicològics, s’ha arribat a determinar que el coit no afecta negativament ni positivament el rendiment físic. L’escassa evidència científica fa que aquest tema prengui importància i se suggereix que es realitzin més investigacions per tal d’oferir consells i educació apropiada a les poblacions físicament actives de diverses edats, com és el cas dels esportistes