Applications of narrative to the engineering decision making process and the pedagogy of engineering education

Narrative is defined as a basic form of human communication. It is through narrative that humans experience and comprehend life. Using narrative as a tool to improve communication and comprehension requires incorporating several components into a complete narrative structure. The components of a narrative consist of a story; that is, a sequence of events providing chronological order and context to a subject, and a method of discourse; that is, the means in which the story is told. Creating narrative allows for increased cognitive understanding of a subject because it is the way in which we as humans naturally communicate. This paper examines how narrative may be used in engineering decision making. Engineering is a field where data is often presented with little context. This data is difficult to understand at first glance and occasionally requires explanation from experts closest to the data set. Engineering courses are not much different in that students are often faced with computational problems that are taken out of context. Practice in solving problems is necessary; however, these problems are often out of context and use idealized situations, thus hindering students\u27 ability to transfer knowledge to new situations. Using narrative to place problems in a real world context allows the students to experience situations closer to real world working environments. Outside of the engineering classroom, engineers face large amounts of data generated from projects with large design teams. Arranging the data into a narrative by adding layers of context can aid in comprehension of project data and also help bridge communication gaps between multiple engineering disciplines. Engineering groups tend to do this today, and indeed many companies have formalized engineering processes that unknowingly create a narrative. Understanding the nature of narrative can improve these processes. In addition, engineering software today is like a shattered mosaic of brilliant colors, and building software that brings these pieces of the mosaic into a coherent, integrated picture would significantly benefit the engineering decision making process

The Oboe is a Lady: The Legacy of Britain's Female Professional Oboists, 1920-2000

From the 1920s through the present day, professional female oboists have worked in a variety of settings throughout the United Kingdom, as soloists, chamber musicians, and orchestral players. This group of musicians has been highly influential, inspiring numerous compositions and premiering important works, many of which have become mainstays of the repertoire. Beyond their roles as performers and collaborators, almost all of these oboists were also dedicated educators, directly influencing future generations of musicians. This paper details the lives and careers of several prominent female oboists, including lists of pieces associated with each musician

π‐Extended Diaza[7]helicenes by Hybridization of Naphthalene Diimides and Hexa‐peri‐hexabenzocoronenes

The synthesis of an unprecedented, π‐extended hexabenzocorene (HBC)‐based diaza[7]helicene is presented. The target compound was synthesized by an ortho‐fusion of two naphthalene diimide (NDI) units to a HBC‐skeleton. A combination of Diels–Alder and Scholl‐type oxidation reactions involving a symmetric di‐NDI‐tolane precursor were crucial for the very selective formation of the helical superstructure via a hexaphenyl‐benzene (HPB) derivative. The formation of the diaza[7]helicene moiety in the final Scholl oxidation is favoured, affording the symmetric π‐extended helicene as the major product as a pair of enantiomers. The separation of the enantiomers was successfully accomplished by HPLC involving a chiral stationary phase. The absolute configuration of the enantiomers was assigned by comparison of circular dichroism spectra with quantum mechanical calculations

Studying Dynamics by Magic-Angle Spinning Solid-State NMR Spectroscopy: Principles and Applications to Biomolecules

International audienceMagic-angle spinning solid-state NMR spectroscopy is an important technique to study mo- lecular structure, dynamics and interactions, and is rapidly gaining importance in biomolecu- lar sciences. Here we provide an overview of experimental approaches to study molecular dy- namics by MAS solid-state NMR, with an emphasis on the underlying theoretical concepts and differences of MAS solid-state NMR compared to solution-state NMR. The theoretical foundations of nuclear spin relaxation are revisited, focusing on the particularities of spin re- laxation in solid samples under magic-angle spinning. We discuss the range of validity of Redfield theory, as well as the inherent multi-exponential behavior of relaxation in solids. Ex- perimental challenges for measuring relaxation parameters in MAS solid-state NMR and a few recently proposed relaxation approaches are discussed, which provide information about time scales and amplitudes of motions ranging from picoseconds to milliseconds. We also discuss the theoretical basis and experimental measurements of anisotropic interactions (chemical-shift anisotropies, dipolar and quadrupolar couplings), which give direct infor- mation about the amplitude of motions. The potential of combining relaxation data with such measurements of dynamically-averaged anisotropic interactions is discussed. Although the focus of this review is on the theoretical foundations of dynamics studies rather than their ap- plication, we close by discussing a small number of recent dynamics studies, where the dy- namic properties of proteins in crystals are compared to those in solution

A Functional Hexaphenylbenzene Library Comprising of One, Three, and Six Peripheral Rylene‐Diimide Substituents

Abstract Synthesis and characterization of a series of rylene‐diimide substituted hexaphenylbenzenes (HPBs) is presented. The direct connection of the rylene‐diimide units to the HPBs via the imide‐N‐position without any linkers as well as the use of naphthalene‐diimides (NDIs) next to perylene‐diimides (PDIs) is unprecedented. While mono‐substituted products were obtained by imidization reactions with amino‐HPB and the respective rylene‐monoimides, key step for the formation of tri‐ and hexa‐substituted HPBs is the Co‐catalysed cyclotrimerization. Particular emphasis for physic‐chemical characterization was on to the number of NDIs/PDIs per HPB and the overall substitution patterns. Lastly, Scholl oxidation conditions were applied to all HPB systems to generate the corresponding hexa‐peri‐hexabenzocoronenes (HBCs). Importantly, the efficiency of the transformation strongly depends on the number of NDIs/PDIs. While three rylene‐diimide units already hinder the Scholl reaction, the successful synthesis of mono‐substituted HBCs is possible

Applications of narrative to the engineering decision making process and the pedagogy of engineering education

Narrative is defined as a basic form of human communication. It is through narrative that humans experience and comprehend life. Using narrative as a tool to improve communication and comprehension requires incorporating several components into a complete narrative structure. The components of a narrative consist of a story; that is, a sequence of events providing chronological order and context to a subject, and a method of discourse; that is, the means in which the story is told. Creating narrative allows for increased cognitive understanding of a subject because it is the way in which we as humans naturally communicate. This paper examines how narrative may be used in engineering decision making. Engineering is a field where data is often presented with little context. This data is difficult to understand at first glance and occasionally requires explanation from experts closest to the data set. Engineering courses are not much different in that students are often faced with computational problems that are taken out of context. Practice in solving problems is necessary; however, these problems are often out of context and use idealized situations, thus hindering students' ability to transfer knowledge to new situations. Using narrative to place problems in a real world context allows the students to experience situations closer to real world working environments. Outside of the engineering classroom, engineers face large amounts of data generated from projects with large design teams. Arranging the data into a narrative by adding layers of context can aid in comprehension of project data and also help bridge communication gaps between multiple engineering disciplines. Engineering groups tend to do this today, and indeed many companies have formalized engineering processes that unknowingly create a narrative. Understanding the nature of narrative can improve these processes. In addition, engineering software today is like a shattered mosaic of brilliant colors, and building software that brings these pieces of the mosaic into a coherent, integrated picture would significantly benefit the engineering decision making process.</p

Rylen-Hexabenzocoronen Konjugate

The main task of the following thesis was the synthesis and characterization of unprecedented rylene-hexabenzocoronen conjugates and the investigation of their photophysical and (opto)electronical properties. Naphthalene- (NDI) as well as perylenediimide (PDI) derivatives, featuring attractive electron acceptor qualities, were therefore covalently linked to electron donating hexa-peri-hexabenzocoronenes (HBC). Within this work a variety of conjugates were prepared which can be distinguished by different substitution degrees as well as varying binding motifs. The project starts with the synthesis of rylenediimide-hexaphenylbenzenes (HPBs), which are suitable precursors for the transformation to the corresponding HBCs. When used as a central unit, HPB offers the possibility to prepare mono-, tri- and hexa-substituted conjugates by applying imidization and [2+2+2] cyclotrimerization reactions (publication 1). NDIs/PDIs were directly attached to the HPB via the imide-N position without any linker to guarantee a more rigid structure. SCHOLL oxidation, to generate the aromatic π-system of the corresponding HBCs, worked well for the mono-substituted systems. If three or more rylenediimide-units are present, however, successful planarization to HBC is hampered under these conditions. Fundamental photophysical and electrochemical properties were investigated for all compounds. The second approach of this part relies on the bay-functionalization of a central PDI with one or two hexaarylbenzene (HAB) -substituents (publication 2). The bulky HABs prevent aggregation of the perylene-core which was supported by X-ray analysis. In addition, different peri-functionalities were compared with respect to their photophysical properties. Significant variations of the UV-vis absorption and fluorescence emission spectra confirmed the importance of isomeric purity of such systems. To improve the electronic communication between rylenediimide acceptor and HBC donor, the generation of fully π-conjugated hybrids was the primary objective of the second part of this thesis. Therefore, one rylenediimide moiety was fused to the HBC by the formation of an aromatic benzimidazole linker (publication 3). Following DIELS-ALDER and SCHOLL-type chemistry π-extended structures were obtained, containing either a [5]helicene or a linear bridge. Separate characterization of the isomers enabled a detailed analysis of the influence of the nonplanar helicene unit on the photophysical properties. Variations in absorption and emission properties as well as improved solubility indicate the relevance of this modification. Next, HBCs with two NDIs attached in an ortho-position were targeted (publication 4). Similar to the synthetic concept established for the aforementioned mono-fused systems, the respective di-NDI-tolane precursor was reacted in an DIELS-ALDER reaction. Subsequent SCHOLL oxidation yields a π-extended diaza[7]helicene which was formed selectively out of three possible isomers. Photophysical and chiroptical investigations on the corresponding enantiomers were carried out and supported by theoretical calculations. Last, the generation of more complex systems by adding further chromophores to rylenediimide-HBCs is described (publication 5). Ortho-substituted NDI- as well as PDI-porphyrin-HBCs were synthesized via DIELS-ALDER and SCHOLL-oxidation reactions. The photophysical properties were investigated by UV-vis and fluorescence emission spectroscopy, indicating strong electronic communication between the three compounds. Especially PDI-porphyrin-HBC, which displays pronounced absorptions in the whole range of the visible region, exhibits a strong energy transfer from the PDI to the porphyrin.Die Hauptaufgabe der folgenden Arbeit bestand aus der Synthese und Charakterisierung neuartiger Rylen-Hexabenzocoronen Konjugate und die Untersuchung deren photophysikalischen und (opto)elektronischen Eigenschaften. Naphthalen- (NDI) sowie Perlyendiimid (PDI), welche attraktive Elektronen-Akzeptoren darstellen, wurden dafür kovalent mit dem Elektronen-donor Hexa-peri-hexabenzocoronen (HBC) verknüpft. So konnte eine Vielzahl an Verbindungen hergestellt werden, welche sich durch variierende Substitutionsmuster und Bindungstypen unterscheiden. Die Arbeit beginnt mit der Synthese von Rylendiimid-Hexaphenlybenzolen (HPBs), die als geeignete Vorstufen für die Umwandlung zu den jeweiligen HBCs genutzt werden sollen. Wird HPB als zentrales Verbindungselement verwendet, können mit Hilfe von Imidisierungs- und [2+2+2] Cyclotrimerisierungsreaktionen einfach-, dreifach- und sechsfach-funktionalisierte Moleküle hergestellt werden (Publikation 1). Um möglichst starre Strukturen zu erhalten, wurden die NDIs/PDIs über den Stickstoff der Imid-Gruppe direkt an das zentrale HPB gebunden, ohne zusätzliche Verbindungselemente zu verwenden. Die SCHOLL-Oxidation, in der das aromatische π-System des HBCs geformt werden soll, funktionierte gut mit einfach-substituierten HPBs. Sind jedoch drei oder mehr Rylendiimide gegenwärtig, so ist eine erfolgreiche Planarisierung zu HBC unter den getesteten Bedingungen nicht möglich. Fundamentale photophysikalische und elektrochemische Eigenschaften wurden für alle Verbindungen untersucht. Eine andere Möglichkeit die beiden Substanzklassen PDI und HPB miteinander zu kombinieren beruht auf der bay-Funktionalisierung von zentralen PDIs mit einem oder zwei Hexaarylbenzol (HAB) -Substituenten (Publikation 2). Durch die Größe und dem hohen sterischen Anspruch der HABs wird eine Aggregation der Perylen-Kerne verhindert, was mit Hilfe von Röntgenstrukturanalyse bewiesen werden konnte. Des Weiteren wurden unterschiedliche Funktionalisierungen an der peri-Position in Bezug auf ihre photophysikalischen Eigenschaften miteinander verglichen. Dabei bestätigten stark variierende UV-vis-Absorptions- und Fluoreszenz-Emissionsspektren die Wichtigkeit der Isomerenreinheit solcher Verbindungen. Um die elektronische Kommunikation zwischen Ryendiimiden als Elektronenakzeptoren und HBC als Elektronendonor zu verbessern, war das primäre Ziel des zweiten Teils dieser Arbeit die Entwicklung vollständig π-konjugierter Strukturen. Dafür wurde ein Rylendiimid über eine aromatische Benzimidazol-Brücke mit HBC verknüpft (Publikation 3). Durch DIELS-ALDER- und SCHOLL-Reaktionen wurden π-erweiterte Verbindungen erhalten, welche entweder eine [5]helikale oder eine lineare Verbrückung aufweisen. Eine getrennte Charakterisierung der Isomere ermöglichte eine genaue Analyse des Einflusses der nicht-planaren Helix-Struktur auf die photophysikalischen Eigenschaften. Unterschiede in Absorption und Emission sowie eine verbesserte Löslichkeit deuten auf die Relevanz dieser Modifikation hin. Als nächstes wurde die Darstellung von HBCs, die mit zwei NDIs in ortho-Stellung verknüpft sind, angestrebt (Publikation 4). Gemäß dem erarbeiteten Syntheseplan für einfach-fusionierte Systeme wurde ein entsprechendes di-NDI Tolan in einer DIELS-ALDER Reaktion verwendet. Durch anschließende SCHOLL Oxidation konnte ein π-erweitertes Diaza[7]helicen hergestellt werden. Die Reaktion verlief dabei äußerst selektiv, da aus möglichen drei Isomeren nur eines entstand. Die photophysikalischen und chiroptischen Eigenschaften der entsprechenden Enantiomere wurden untersucht und durch theoretische Berechnungen gestützt. Als Letztes wird die Herstellung komplexerer Systeme durch das Hinzufügen weiterer Chromophore an Rylenimid-HBCs beschrieben (Publikation 5). Ortho-substituierte NDI- und PDI-Porphyrin-HBCs wurden über DIELS-ALDER- und SCHOLL-Reaktionen synthetisiert. Die photophysikalischen Eigenschaften wurden mit UV-vis Absorptions- und Fluoreszenz Emissionsspektroskopie untersucht und zeigten starke elektronische Wechselwirkung zwischen den drei Systemen. Besonders PDI-Porphyrin-HBC weist eine ausgeprägte Absorption im gesamten sichtbaren Bereich des Lichts sowie Energietransfer vom PDI zum Porphyrin auf