Light trapping gratings for solar cells an analytical period optimization approach

Solar cells can harvest incident sunlight very efficiently by utilizing grating based light trapping. As the working principle of such gratings strongly depends on the number as well as the propagation directions of the diffraction orders, the grating period is a key parameter. We present an analytical model for optimizing the grating period, focusing on its impact on light path enhancement and outcoupling probability. Based on the presented model, we formulate guidelines to maximize light trapping in state of the art high end solar cells. The model increases the understanding of the grating performance in systems like the III V Si triple junction solar cell achieving record efficienc

AuROA service catalog for scientific open access publications: Transparent listing of tasks for book publications

This service catalog provides a compilation of possible individual tasks and services in the scientific open access publishing process. The catalog is intended for use by all individuals and institutions involved in the publication process in their sometimes overlapping roles: authors and editors, publication service providers (publishers, repositories, etc.), sponsors (foundations, etc.), libraries, and other involved parties. They can decide for themselves which of the listed publication fields, services and technicalities are relevant to their work. On the one hand, the aim is to create a basis for contracts or contract negotiations between the different involved parties in a transparent manner and on an equal footing, and to facilitate comparability. On the other hand, the catalog is intended to promote and facilitate cooperative forms of publication between the parties involved, especially in the digital domain. The catalog is based on the results of the AuROA project (Autor:innen und Rechtssicherheit für Open Access - authors and legal certainty for open access), which examined the heterogeneous and complex needs, perspectives, and requirements entailed in open-access publishing for disciplines that regularly publish in book form. In order to achieve legally secure publication conditions, the AuROA contract generator was developed. This tool generates individual sample contracts for open access publications that are based, among other things, on elements from this service catalog. The University Library of the University of Duisburg-Essen headed the project in a two-year collaborative effort with the Department of Communication and Business at the IST Hochschule für Management in Düsseldorf and the Department of Book and Reading Studies at Johannes Gutenberg University in Mainz

Publizieren und Open Access in den Geisteswissenschaften: Erkenntnisse aus dem Projekt AuROA zu den Stakeholdern im Publikationsprozess

In einer Umfrage und zwei Workshops hat das Projekt AuROA Erkenntnisse zu den Stakeholdern im geistes- und sozialwissenschaftlichen Publikationsprozess sowie ihren Perspektiven gesammelt. Diese ergänzen die Erkenntnisse aus weiteren Veranstaltungen und einer Vielzahl von persönlichen Gesprächen. Die wichtigsten Themen der Workshops waren Hürden und Lösungsansätze in OpenAccess-Publikationsabläufen für und zwischen den verschiedenen Stakeholdergruppen. Die Umfrage beleuchtete insbesondere Publikationserfahrungen von Autor:innen sowie deren Positionen zu Open Access, Verlagsrenommee und Verlagsdienstleistungen. Der Schwerpunkt lag hierbei stärker auf den Geistes- als auf den Sozialwissenschaften. Geistes- und Sozialwissenschaftler:innen sind dabei vor allem in den klassischen Publikationsformen wie Monographien, Sammelwerken und Zeitschriftenartikeln erfahren. Letztere haben dabei nicht den herausragenden Status wie im STM-Bereich. Die genutzten Publikationsformen stimmen dabei nicht unbedingt mit jenen überein, die als besonders renommiert eingeschätzt werden. Open Access stehen die Befragten sehr positiv gegenüber, sind in der Praxis aber noch nicht sehr vertraut mit den konkreten Möglichkeiten, Open Access zu publizieren. Wichtig ist den Stakeholdern die Abgrenzung von den Rahmenbedingungen im STM-Bereich, dessen breite Lösungen sie als nicht zielführend ansehen. Zu den Gründen gehören die sehr kleinteiligen Verlags- und Disziplinen-Landschaften in den Geistes- und Sozialwissenschaften. Welche Verlage als besonders renommiert angesehen werden, hängt dabei wenig mit den Dienstleistungen der Verlage zusammen. Stattdessen werden Verlage nach einem tradierten Markennamen und einer historisch gewachsenen Marktposition beurteilt, aber auch nach fachrelevanten Publikationen und namhaften Herausgeber:innen. Selbst bei renommierten Verlagen zeigt sich allerdings auch eine hohe Quote an Unzufriedenheit mit den tatsächlich erbrachten Dienstleistungen. Im Hinblick auf finanzielle Komponenten und die Rechtsberatung unterscheiden sich die Antworten der befragten Geistes- und Sozialwissenschaftler:innen in der Umfrage von den Antworten der heterogenen Stakeholder-Gruppen in den Workshops: Aus ihrer persönlichen Perspektive als Autor:innen gewichten Geistes- und Sozialwissenschaftler:innen das Renommee eines Verlags nicht nach den Kosten der Publikation, weder hinsichtlich der erhobenen Gebühren noch des Preises des Produkts. Aus einer breiteren Sicht auf das Publikationsfeld nennen Teilnehmer:innen der Workshops die Finanzierung von Publikationen hingegen als eine der drängendsten aktuellen Fragen. Ähnliches gilt für juristische Beratung: Autor:innen erhalten eher selten Rechtsberatung durch Verlage. Dieses Thema spielt jedoch laut Aussagen in den Workshops eine zentrale Rolle für Autor:innen, Verlage und Bibliotheken – insbesondere für letztere, die in vielen Fällen unter Rechtsvorbehalt beraten

The design and manufacture of immediate-release optimal solid dosage forms

Thesis: Ph. D., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2014.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Cataloged from student-submitted PDF version of thesis.Includes bibliographical references.Pharmaceutical manufacturing has traditionally been considered largely a matter of regulatory compliance. Consequently, it has been inefficient, but it is now increasingly being recognized as an opportunity for cost reduction. Recent initiatives by regulatory authorities, and by the industry, aim at easing regulations and encouraging process innovation. Even though significant improvements, especially in process control and minimization of process interruptions, have been achieved, the underlying process technology has not changed for decades. For example, typical process steps to produce the most common pharmaceutical products, immediate-release solid dosage forms, from drug substance and excipient are: blending, wet granulating, drying, milling and screening, blending, tableting, coating, and so on. A new process, such as blending combined with solvent-less, multi-component injection-molding could greatly simplify manufacturing. Injection-molding, however, yields a non-porous material, intrinsically different from the state-of-the-art powder-compacted, porous dosage forms. This may appear problematic, because current products rely on a large surface area-to-volume ratio to achieve immediate drug release. In addition, process rates previously achieved by injection-molding solid dosage forms have been comparably low -- offsetting some of the benefits offered by that process. In this thesis, an analytical approach is first developed to model drug release from non-porous dosage forms, comprising a fast eroding excipient and randomly distributed drug particles in it. The model considers the central role of microstructure in drug release. Particular importance is given to the role of clusters of connected, slowly eroding drug particles, and to the effect of drug particle protrusion, due to their slow erosion rate, from the eroding excipient surface. The model is validated by dissolution experiments. Good agreement is observed between the model and the experimental data. The drug release model is then used in product design for manufacturing as an optimization problem -- with manufacturing performance as objective function and design specifications as constraints. It is found that the drug volume fraction needs to be about 0.5 to efficiently produce non-porous dosage forms in specification, which implies that an excessive amount of excipient material is required. Therefore, new product designs are proposed: a cellular excipient micro-structure with up to ten-fold reduction in excipient content. The new designs are further shown to allow injection-molding of immediate-release dosage forms that meet specifications with a three-fold increase in injection-molding process rate compared with conventional designs.by Aron H. Blaesi.Ph. D

Temporal Dynamics in the Perception of Intentions

The perception and understanding of human behavior is fundamental for social interaction. Mostly grounded in the theory of embodied cognition, the study of intentional action has focused on different aspects such as action planning and execution, action identity, and action prediction. Based on principles of dynamical systems theory (DST), the goal of this study is to test the method of using eye tracking to expand our knowledge of the temporal dynamics of human intention perception by investigating the time-locked sequence of eye movements during social interaction to investigate the online decision making process during an action observation task. Stimuli consist of 5 sec videos portraying reach and grasp actions, which are either intentional (pour coffee) or unintentional (coffee spills), cooperative action (serve other) or non-cooperative (serve self). In condition 1 participants are asked to determine whether an action presented is intentional, condition 2 whether the action is cooperative while collecting eye tracking data. This study hypothesized that participants' eye movements will be sensitive to the task demands, predicting that (H1) participants in the intentional group will be more likely to attend to the object interactions as compared to the cooperative condition and (H2) participants in the cooperative group will be more likely to attend to social cues between the agents as compared to the intentional condition. The results show that the intentional group was more likely to focus on the object interactions in support of hypothesis 1. Furthermore, results also showed that the cooperative group focused more on social cues in support of hypothesis 2. Therefore, the results of this study strongly support the theory that cognitive processes such as decision-making during an intentional or cooperative action are emergent and the temporal dynamics can be made visible through eye tracking. In support of the dynamical systems theory, external influences such as task demand were shown to have an effect on the viewing pattern, duration of fixations, as well as attention to target details while observing a dynamic, natural and social interaction

Grounding, physicalism, and the explanatory gap

Contemporary metaphysics is marked by a revived interest in the notion of ground. Some philosophers have even suggested that this is the notion needed to best formulate physicalism---the view that the mental is “nothing over and above” the physical. For there are reasons to think that physicalism understood as a grounding thesis (Grounding Physicalism) has advantages over the traditional options. In short, the appeal of Grounding Physicalism is that it promises to occupy a middle position between reductive and non-reductive versions of physicalism. Despite its initial appeal, I argue that a new spin on a common objection to physicalism---that it leaves an “explanatory gap”---undermines the enthusiasm for Grounding Physicalism. The explanatory gap problem has been heavily discussed, but usually with the assumption that physicalism is an identity thesis. By contrast, I focus on Grounding Physicalism and argue that it leaves an explanatory gap---moreover, one that cannot be addressed in the usual way. I then argue that this creates a dilemma for the Grounding Physicalist.Philosoph

Perceived difficulty of a motor task affects memory but not action.

Successful motor interaction with a target changes memory of the target's size, which seems larger if the action was successful than if it was unsuccessful. This has been attributed to the effect of action on subsequent perception or memory. We asked what the action provides: Is feedback from the action necessary, or only the information provided by the action? We found that perceived difficulty alone changes the remembered goal characteristics, without changes in the stimuli, and before the motor task is executed. We gave observers a marble and showed them a hole in a box. They were told that throwing the marble into the hole was either difficult or easy, depending on the condition. The hole was then covered and its size judged. Participants who were told that the task was difficult judged the hole to be significantly smaller than it was, whereas those told that the task was easy made judgements not significantly different from veridical. When observers subsequently threw the marble, their success rates were independent of their own estimates of hole size or of what they had been told about the difficulty of the task, showing that their size estimates affected memory but not action. In a second experiment, we found that the effect disappeared if the hole was visible during the size estimation

Perceived difficulty of a motor task affects memory but not action.

Successful motor interaction with a target changes memory of the target's size, which seems larger if the action was successful than if it was unsuccessful. This has been attributed to the effect of action on subsequent perception or memory. We asked what the action provides: Is feedback from the action necessary, or only the information provided by the action? We found that perceived difficulty alone changes the remembered goal characteristics, without changes in the stimuli, and before the motor task is executed. We gave observers a marble and showed them a hole in a box. They were told that throwing the marble into the hole was either difficult or easy, depending on the condition. The hole was then covered and its size judged. Participants who were told that the task was difficult judged the hole to be significantly smaller than it was, whereas those told that the task was easy made judgements not significantly different from veridical. When observers subsequently threw the marble, their success rates were independent of their own estimates of hole size or of what they had been told about the difficulty of the task, showing that their size estimates affected memory but not action. In a second experiment, we found that the effect disappeared if the hole was visible during the size estimation