Directional Stability of Towed Airplanes

So far, very careful investigations have been made regarding the flight properties, in particular the static and dynamic stability, of engine-propelled aircraft and of untowed gliders. In contrast, almost no investigations exist regarding the stability of airplanes towed by a towline. Thus, the following report will aim at investigating the directional stability of the towed airplane and, particularly, at determining what parameters of the flight attitude and what configuration properties affect the stability. The most important parameters of the flight attitude are the dynamic pressure, the aerodynamic coefficients of the flight attitude, and the climbing angle. Among the configuration properties, the following exert the greatest influence on the stability: the tow-cable length, the tow-cable attachment point, the ratio of the wing loadings of the towing and the towed airplanes, the moments of inertia, and the wing dihedral of the towed airplane. In addition, the size and shape of the towed airplane vertical tail, the vertical tail length, and the fuselage configuration are decisive factors in determining the yawing moment and side force due to sideslip, respectively

Deformation analysis using navier spline interpolation (with an application to the Lake Blasjoe area)

The static deformation of the surface of the earth caused by surface pressure like the water load of an ocean or an artificial lake is discussed. First a brief mention is made on the solution of the Boussinesq problem for an infinite halfspace with the elastic medium to be assumed as homogeneous and isotopic. Then the elastic response for realistic earth models is determined by spline interpolation using Navier splines. Major emphasis is on the determination of the elastic field caused by water loads from surface tractions on the (real) earth's surface. Finally the elastic deflection of an artificial lake assuming a homogeneous isotropic crust is compared for both evaluation methods. (orig.)Available from TIB Hannover: RO 5810(136)+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Flexible Automatisierung des Spritzgiessens. Abschlussbericht Anforderungsspezifikation an das Gesamtsystem und Erprobung: Thermoplastspritzgiessen. Entwicklung der Gesamtkonzeption eines modularen flexiblen Fertigungssystems, Realisierung der Maschinen- und Kommunikationstechnik, Projektkoordination

Available from TIB Hannover: QN1(3,14) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Evolução de atributos físicos de solo em sistema de integração lavoura-pecuária

O objetivo deste trabalho foi avaliar o efeito das alturas de pastejo e dos sucessivos ciclos de pastejo sobre os atributos físicos do solo, em um sistema de integração lavoura-pecuária. O experimento foi implantado em 2001, na região do Planalto Médio, RS, em um Latossolo Vermelho, com o cultivo consorciado de azevém (Lolium multiflorum) e de aveia-preta (Avena strigosa), sob pastejo contínuo, no inverno, e o cultivo de soja (Glycine max) no verão. Os tratamentos consistiram de diferentes intensidades de pastejo, definidas pela altura da pastagem (10, 20, 30 e 40 cm), tendo-se utilizado uma área sem pastejo como controle. Foram avaliadas a densidade e a porosidade do solo após o ciclo de pastejo e de cultivo da soja, bem como a resistência mecânica do solo à penetração e a estabilidade de agregados no sétimo ano do experimento. Não houve alterações significativas na densidade e na porosidade do solo após sete anos em integração lavoura-pecuária. A resistência do solo à penetração é maior na camada superficial após o ciclo de pastejo. A agregação do solo aumenta nas áreas pastejadas, independentemente da intensidade de pastejo

Содержание. Секция 07 - Оптика и спектроскопия

The remarkable complexity of soil and its importance to a wide range of ecosystem services presents major challenges to the modeling of soil processes. Although major progress in soil models has occurred in the last decades, models of soil processes remain disjointed between disciplines or ecosystem services, with considerable uncertainty remaining in the quality of predictions and several challenges that remain yet to be addressed. First, there is a need to improve exchange of knowledge and experience among the different disciplines in soil science and to reach out to other Earth science communities. Second, the community needs to develop a new generation of soil models based on a systemic approach comprising relevant physical, chemical, and biological processes to address critical knowledge gaps in our understanding of soil processes and their interactions. Overcoming these challenges will facilitate exchanges between soil modeling and climate, plant, and social science modeling communities. It will allow us to contribute to preserve and improve our assessment of ecosystem services and advance our understanding of climate-change feedback mechanisms, among others, thereby facilitating and strengthening communication among scientific disciplines and society. We review the role of modeling soil processes in quantifying key soil processes that shape ecosystem services, with a focus on provisioning and regulating services. We then identify key challenges in modeling soil processes, including the systematic incorporation of heterogeneity and uncertainty, the integration of data and models, and strategies for effective integration of knowledge on physical, chemical, and biological soil processes. We discuss how the soil modeling community could best interface with modern modeling activities in other disciplines, such as climate, ecology, and plant research, and how to weave novel observation and measurement techniques into soil models. We propose the establishment of an international soil modeling consortium to coherently advance soil modeling activities and foster communication with other Earth science disciplines. Such a consortium should promote soil modeling platforms and data repository for model development, calibration and intercomparison essential for addressing contemporary challenges