Was heißt „Der freie Mensch allein weiß, dass eine Welt außer ihm ist“?

Der Beitrag analysiert ein methodisches Problem der Schellingschen Naturphilosophie: wie das transzendentalphilosophische Prinzip der Freiheit mit der Natur in Verbindung steht. Dabei wird deutlich, dass die Neue Naturphilosophie (in Jena 1798-1803) eine Verifikation des Idealismus entfaltet: Der Idealismus hat methodisch Recht, wenn er die Vernunft zum ‚Selbstschöpfer’ (Autopoiesis) von allem macht, denn dies ist in der Natur selbst begründet. Damit kann der Idealismus – modern – eine analytische Dimension für den Bau der Welt entfalten

Zu einigen Aspekten der Internationalität des Bauhauses und seiner Studentenschaft

Wissenschaftliches Kolloquium vom 24. bis 26. Juni 1986 in Weimar an der Hochschule für Architektur und Bauwesen zum Thema: 'Der wissenschaftlich-technische Fortschritt und die sozial-kulturellen Funktionen von Architektur und industrieller Formgestaltung in unserer Epoche

A time series approach to the monetary sector of the South African economy

Bibliography: p. 111-114.This thesis provides an investigation of the applicability of time series analysis to the process of economic model building. Chapter l explains the position of the Box-Jenkins approach to time series analysis in relation to other techniques of analysis. In Chapters 2 and 3 the theory of model building is discussed. In Chapter 4 an econometric model is analysed in detail from a time series approach

The Correlation Between Treasury Securities and the Stock Market: A Study of Explanatory Variables

The purpose of the thesis is to retrieve the correlation between treasury securities of different maturities and the stock market and find significant variables to explain this relationship. Correlation time series were retrieved and used as dependent variables in a multivariate regression in order to find significant explanatory variables. The theory includes prior research done on the relationship between the stock market and treasury securities. Further the stock market and treasury securities are studied in detail. The highest explanatory power for the model was found for the 10 year note and stock market correlation. Significant variables of main importance were the volume traded, federal funds rate return and the business cycle. Support for the flight into quality theory was retrieved, as well as evidence of the importance for variables based on macroeconomic factors for the three correlation series

Non-Apis bees as model organisms in laboratory, semi-field and field experiments

Im Rahmen der Zulassung von Pflanzenschutzmitteln und ihren Wirkstoffen in der EU wurde das Risiko für Bienen bisher anhand der Westlichen Honigbiene (Apis mellifera L.) als Modellorganismus für alle Bienenarten bewertet. In den letzten Jahren wurde kontrovers diskutiert, ob Wildbienenarten in der Risikobewertung ebenfalls berücksichtigt werden sollten, um die bisherigen Daten­anforderungen für Honigbienen zu erweitern. Dies geht damit einher, etablierte, standardisierte Methoden für die Honigbiene an zusätzliche Wildbienenarten anzupassen und zu verstehen, wie diese Arten auf den verschiedenen Testebenen (Labor-, Halbfreiland- und Freilandtests) eingesetzt werden können. In diesem Artikel gehen wir zunächst auf die Bedeutung von Bienen als Testorganismen ein, diskutieren den derzeitigen Stand der Forschung, die für die Methodenentwicklung und das experimentelle Design für das Arbeiten mit Bienen wichtig ist, um abschließend einen Ausblick auf aktuelle Aktivitäten in der Standardisierung von Testmethoden zu geben.As part of the registration process of plant protection products (PPPs) and their active substances in the EU, the risk of PPPs for bees has been assessed so far by using the European honey bee (Apis mellifera L.) as a surrogate species. In the past few years other bee species have been discussed to augment data on honey bees. The addition of bee species in the registration process goes along with adapting test methodologies to new bee species and understand­ing how to use these species at different tiers (laboratory, semi-field and field levels). Here we first discuss the importance of bees as test organisms, outline the current state of research relevant to the methodology and design of experiments with bees and highlight recent activities in the standardization of test procedures

Stillen als wissenschaftlicher Gegenstand. Epistemologische Überlegungen zur Untersuchung einer "natürlich sozialen Tatsache am Beispiel des medizinischen Diskurses

Im gesellschaftlichen Diskurs um das Stillen ist gegenwärtig, trotz fundierter sozialwissenschaftlicher Kritik, immer noch die Position als hegemonial zu bezeichnen, die das Stillen als die beste Form der Säuglingsernährung sieht. Um die Hintergründe für die Macht dieser Position besser verstehen zu können, befragt der Aufsatz medizinische Publikationen aus über einem Jahrhundert aus der wissenschaftstheoretischen Perspektive der französischen Epistemologie und zeichnet die sich darin zeigende Wissensordnung um das Stillen nach: Wie hat sich das Stillen als wissenschaftlicher Gegenstand infolge der Verwissenschaftlichung der Medizin konstituiert? Wie wurde er im Kontext moderner Dichotomien zwischen dem Natürlichen und dem Sozialen positioniert? Welche Hierarchien wurden damit bedient, stabilisiert oder unterlaufen? Zentral für die Argumentation sind drei Erkenntnishindernisse im Sinne Gaston Bachelards, die im Untersuchungszeitraum des 19. Jahrhunderts eine Verschiebung des Gegenstands Stillen von einer natürlichen zu einer "natürlich sozialen Tatsache" erschwerten: die Hybridität der Medizin als Disziplin, die kumulative Praxis der medizinischen Forschung und ihr Fokus auf die Mutter-Kind-Dyade.Although the social sciences have over the years expressed well-founded criticism, in the contemporary public discourse in Germany breastfeeding is still considered to be the best way to feed a baby. In order to be able to better understand why this is the case, this article discusses material taken from the medical discourse in Germany during the late 19th and 20th century while exploring the potential of the epistemological concept of rupture, which originates in the French sociological tradition. The following questions will be answered: How was breastfeeding constituted as a scientific subject of research during the process of scientification of medicine? Where did this scientific subject of research end up caught between the social and the natural? What kinds of hierarchy were stabilized or subverted as a result? This line of reasoning sheds light on three epistemological obstacles which exacerbate breastfeeding shifting from being a natural to becoming a naturally social fact in the period investigated: medicine as a hybrid discipline, cumulative practices of medical research and its focus on the dyad of mother and child

Energy-momentum time integrations of a non-isothermal two-phase dissipation model for fiber-reinforced materials based on a virtual power principle

Fiber-reinforced plastics (FRP) are composite materials made of an isotropic polymer matrix reinforced with organic or inorganic fibers. The major contribution to the internal dissipation in FRP is due to the isotropic matrix material. However, internal dissipation in the fibers has to be taken into account if Carbon or Kevlar fibers, respec- tively, are applied [1], or by using organic fibers, applied in the automotive industry [2]. Therefore, we introduce in this presentation a new two-phase dissipation model at finite strains with independent viscoelastic behaviour in the matrix and the fibers. This model is based on the multiplicative split of the deformation gradient F := F eF v of the composite in an elastic and viscous deformation gradient F e and F v, respectively, as well as on the multiplicative split of the fiber deformation gradient FF:=FeFFvF an elastic and viscous fiber deformation gradient F e and F v , respectively. However, the time-dependent matrix behaviour depends directly on the principal invariants of the symmetric elastic right Cauchy-Green tensor Ce := [F e]T F e. Analogously, the trace of the elastic fiber right Cauchy-Green tensor CeF := [FeF]T F e F determines the time evolution of the viscous fiber deformation. In the internal power of a mixed principle of virtual power, we consider free energy functions ΨvisM and ΨvisF, depending on matrix and fiber invariants. In the external power, the non-negative internal dissipation with respect to a positive-definite viscosity tensor or a positive fiber viscosity parameter, respectively, is introduced. In this way, we derive the viscous evolution equations by variation. The internal power also includes mixed fields for the thermo-elastic matrix and fiber behaviour. Algorithmic terms in the virtual external power provide energy-momentum time integrations of this two-phase model

Thermo-mechanical coupling in fiber-reinforced continua: mixed finite element formulations and energy-momentum time integration

Our research activity is motivated by accurate dynamic simulations of fiber- reinforced materials in light-weight structures. In order to accomplish this, we have to take various steps. The material behavior is formulated with an anisotropic, polyconvex strain energy function. We combine different mixed element formulations (e.g. see Ref- erence [2] or [3]) with a Galerkin time integrator as shown in Reference [5]. This reduces the volumetric locking effect of an incompressible matrix material as well as the locking effect due to stiff fibers. In addition, we increase the accuracy by using Galerkin-based higher-order time integrators. Since in long-term simulations a hugh energy error is a strong problem, we apply the mixed finite element formulations to an energy-momentum time integration scheme (see Reference [6]). In the next step, we extend the material formulation by adding a thermo-mechanical coupling as shown in Reference [7]. Here we also describe the directional heat conduction of the fiber. As numerical examples with multiple material domains and families of fibers serve cooks cantilever beam as in Ref- erence [5]. The Dirichlet boundary conditions are modelled by the Lagrange-multiplier method (see Reference [7]) and as Neumann boundary condition a pressure distribution is used

Energy-momentum time integration of gradient-based models for fiber-bending stiffness in anisotropic thermo-viscoelastic continua

[EN] For our research, we are motivated by dynamic simulations of 3D fiber-reinforced materials in lightweight structures. In such materials, the material reinforcement is performed by fiber rovings with a separate bending stiffness, which can be modelled by a second order gradient of the deformation mapping. Therefore, we extend a thermo-viscoelastic Cauchy continuum for fiber-matrix composites with single fibers by an independent field for the gradient of the right Cauchy-Green tensor. On the other hand, we focus on numerically stable dynamic long-time simulations with locking free meshes, and thus use higher-order accurate energy-momentum schemes emanating from mixed finite element methods. Hence, we adapt the variational-based space-time finite element method to the new material formulation, and additionally include independent fields to obtain well-known mixed finite elements. As representative numerical example, Cook’s cantilever beam is considered. We primarily analyze the influence of the fiber bending stiffness, as well as the spatial and time convergence up to cubic order. Furthermore, we look at the influence of the physical dissipation in the material.  The authors thank the ’Deutsche Forschungsgemeinschaft (DFG)’ for the financial support of this work under the grant GR3297/4-2 and GR3297/6-1 as well as Matthias Bartelt (GR 3297/2-2) for providing the programming basis for the current implementation.Dietzsch, J.; Groß, M.; Kalaimani, I. (2022). Energy-momentum time integration of gradient-based models for fiber-bending stiffness in anisotropic thermo-viscoelastic continua. En Proceedings of the YIC 2021 - VI ECCOMAS Young Investigators Conference. Editorial Universitat Politècnica de València. 89-98. https://doi.org/10.4995/YIC2021.2021.12358OCS899

4.14 Developing methods for field experiments using commercially reared bumblebee colonies – initial colony strength and experimental duration as influential factors

Semi-field and field experiments with commercially used bumblebees (e.g. Bombus terrestris) gain more and more importance for both ecological studies and trials on potential side effects of plant protection products. However, standardized, replicable experimental methods are lacking so far and need further development. For example, initial strength of bumblebee colonies may vary across experiments but may be a key factor in successful colony development under field conditions. Trial duration and termination may impact results on total reproductive output (e.g. number of newly produced queens). In this study commercially reared bumblebee colonies of different initial strengths (number of worker bees) were placed along the field margin of each of six field sites. Each site was nested within one of two seasons and planted with one of two arable crops (Brassica napus and Phacelia tanacetifolia). Each colony was spaced approx. 50 m apart from the next colony, and its development was monitored once a week. While the development of half of the colonies was terminated at the first sighting of newly emerging queens within the nesting area, the other half of the colonies was left to develop further until the end of their natural colony cycle. Newly emerging queens were kept within the colonies using queen excluders. Colonies of different initial strengths showed very similar developmental patterns with medium and large colonies peaking slightly earlier than small colonies. Results may help to develop optimal parameters for standardized field tests.Semi-field and field experiments with commercially used bumblebees (e.g. Bombus terrestris) gain more and more importance for both ecological studies and trials on potential side effects of plant protection products. However, standardized, replicable experimental methods are lacking so far and need further development. For example, initial strength of bumblebee colonies may vary across experiments but may be a key factor in successful colony development under field conditions. Trial duration and termination may impact results on total reproductive output (e.g. number of newly produced queens). In this study commercially reared bumblebee colonies of different initial strengths (number of worker bees) were placed along the field margin of each of six field sites. Each site was nested within one of two seasons and planted with one of two arable crops (Brassica napus and Phacelia tanacetifolia). Each colony was spaced approx. 50 m apart from the next colony, and its development was monitored once a week. While the development of half of the colonies was terminated at the first sighting of newly emerging queens within the nesting area, the other half of the colonies was left to develop further until the end of their natural colony cycle. Newly emerging queens were kept within the colonies using queen excluders. Colonies of different initial strengths showed very similar developmental patterns with medium and large colonies peaking slightly earlier than small colonies. Results may help to develop optimal parameters for standardized field tests