Systemtechnik und Gewässergüte: Operationalisierung

Mangelndes Verständnis der Wissenschaftler untereinander kennzeichnet die heutige Wissenschaftskommunikation. Ein Grund hierfür ist sicher die Spezialisierung, die teilweise soweit geht, daß selbst die Vertreter eines Faches das Fach nicht mehr vollständig überblicken und dessen Fachsprache nicht beherrschen. In dem Vorwort von [1] ist der Anspruch formuliert: In der Ausbildung brauchen wir eine Spezialisierung ohne Isolation. Gemeint ist die fachliche Kompetenz, die durch additive Kompetenzen auf anderen Gebieten ergänzt werden muß. Die Systemtheorie vermag als Querschnittsfach mit ihrer integrierenden Eigenschaft und ihren Methoden einen wesentlichen innovativen Beitrag zur Ermittlung der Gewässergüte zu leisten. Die integrierende Eigenschaft bezieht sich auf die Wechselwirkungen/Überschneidungen von gesellschaftlichen, technischen und politischen Bereichen, die einerseits grundverschieden und andererseits durch Sachkonflikte, Interessenkonflikte und Überzeugungskonflikte gekennzeichnet sind. Die Methoden der Systemtechnik als Anwendung der Systemtheorie sind das Werkzeug, um anstelle von den bisherigen Vergleichen und (Teil-)Bewertungen der (simulierten) Auswirkungen vorgegebener fachspezifischer Maßnahmen zu der Lösung der umgekehrten Aufgabe zu gelangen, nämlich der Ermittlung der Maßnahmen, die zum Erreichen einer bestimmten Gewässergüte notwendig sind: Mehrzieloptimierung mit Restriktionen unter Beachtung der Nachhaltigkeit. Hierzu ist Wissen notwendig, anstelle von Spekulationen und Meinungen. Wissen erreicht man nur über Fachwissen und dessen Abstraktion. Die Abstraktion wird durch Operationalisierung/Mathematisierung geleistet. Die mathematischen Modelle der Subsysteme müssen ermittelt und über ihre Wechselwirkungen synthetisiert werden. In dem Aufsatz werden die zugehörigen Begriffe mathematisch definiert und methodisch aufbereitet. Ein einfaches Beispiel illustriert die Vorgehensweise, die sich wesentlich von dem bisherigen Vorgehen der Aggregation von Indikatoren unterscheidet

College Football Attendance in the Long Run: Division II

A balanced panel (52 teams over 38 years) is used to estimate fixed- and random-effects models for average season attendance. All variables are either stationary or cointegrated. Independent variables measure economic conditions, demographic characteristics, and team performance. Contrary to expectations, attendance is an inferior good while travel cost (real gas price per mile driven) is insignificant. Greater undergraduate enrollment increases attendance. Attendance decreases with rising county population in both models – one at ten percent probability. More wins in the current season and a greater number of playoff appearances in the last ten years increase attendance. Lifetime winning percentage is insignificant

Structural, Magnetic, and Electrochemical Characterization of Iron(III) and Cobalt Complexes with Penta-N3O2-dentate Ligands

Six new mononuclear [FeIII(LBr,Cl)X]-complexes (LBr,Cl is the dianionic penta-N3O2-dentate Schiff base ligand N,N′-bis(2’-hydroxy-3-bromo-5-chlorobenzylidene)-1,6-diamino-3-azahexane; X: Cl−, N3−, NCO−, NCS−, NCSe−, CN−) were synthesized and their structures, magnetic and electrochemical properties studied. Structure analysis and magnetic measurements showed that [FeIII(LBr,Cl)CN] is in the low spin state and the other five complexes are in high spin states. Furthermore, the trinuclear mixed valent cobalt complex {[CoIII(LH,H)CN]2[CoII(1-methylimidazole)3(H2O)]} was prepared and its magnetic behavior studied. © 2021 The Authors. European Journal of Inorganic Chemistry published by Wiley-VCH Gmb

A Brønsted ligand molecular switch with five accessible states

A mononuclear Fe(II) complex, prepared with a Brønsted diacid ligand, H2L (H2L = 2-[5-phenyl-1H-pyrazole-3-yl] 6benzimidazole pyridine), shows switchable physical properties and was isolated in five different electronic states. The spin crossover (SCO) complex, [FeII(H2L)2](BF4)2 (1A), exhibits abrupt spin transition at T1/2 = 258 K, and treatment with base yields a deprotonated analogue [FeII(HL)2] (1B), which shows gradual SCO above 350 K. A range of ferric analogues were also characterized. [FeIII(HL)(H2L)](BF4)Cl (1C) has an S = 5/2 spin state, while the deprotonated complexes [FeIII(L)(HL)], (1D), and (TEA)[FeIII(L)2], (1E) exist in the low-spin S = 1/2 state. The electronic properties of the five complexes were fully characterized and we demonstrate in situ switching between multiple states in both solution and the solid-state. The versatility of this simple mononuclear system illustrates how proton donor/acceptor ligands can vastly increase the range of accessible states in switchable molecular devices

Probing Proteinase Active Sites Using Oriented Peptide Mixture Libraries – ADAM-10

Oriented Peptide Mixture Libraries can provide a full matrix of preferred and disfavored amino acids at each subsite of an optimal substrate for a new proteinase. This approach is rapid and convenient, requiring only two mixture libraries to complete the analysis. In this paper we demonstrate an extension of this type of analysis, using a focused library employing unnatural amino acids to probe the depth of the S1 position in the catalytic site of the alpha secretase ADAM-10. This analysis indicates that ADAM- 10 will accept amino acids with substantial length and hydrophobicity (e.g. 2- naphthylalanine), but suggests that the S1 site has limitations in the apparent “width” of substituents being presented (e.g. 1-naphthylalanine; gamma branching). A highly selective and efficient substrate for ADAM-10, with a selectivity factor of 380,000 M-1 s -1 , was derived from the predicted consensus substrate. This detailed analysis provides a starting point for the design of inhibitors of this interesting proteinase

Patterning of Nanoparticle‐Based Aerogels and Xerogels by Inkjet Printing

Nanoparticle-based voluminous 3D networks with low densities are a unique class of materials and are commonly known as aerogels. Due to the high surface-to-volume ratio, aerogels and xerogels might be suitable materials for applications in different fields, e.g. photocatalysis, catalysis, or sensing. One major difficulty in the handling of nanoparticle-based aerogels and xerogels is the defined patterning of these structures on different substrates and surfaces. The automated manufacturing of nanoparticle-based aerogel- or xerogel-coated electrodes can easily be realized via inkjet printing. The main focus of this work is the implementation of the standard nanoparticle-based gelation process in a commercial inkjet printing system. By simultaneously printing semiconductor nanoparticles and a destabilization agent, a 3D network on a conducting and transparent surface is obtained. First spectroelectrochemical measurements are recorded to investigate the charge–carrier mobility within these 3D semiconductor-based xerogel networks