An elementary 1-dimensional model for a solid state lithium-ion battery with a single ion conductor electrolyte and a lithium metal negative electrode

As noted above, this contribution is dedicated to Norman Fleck on the occasion of his 60th birthday. I have spent many happy hours in collaboration with Norman, and it has been highly productive, educational, rewarding and enjoyable to do so. I look forward to further interactions with him on the subject of this paper, lithium-ion batteries. This work was funded by the University of California, Santa Barbara and by the University of Aberdeen.Peer reviewedPostprin

A Modified Electrochemical Model to Account for Mechanical Effects Due to Lithium Intercalation and External Pressure

For a battery cell, both the porosity of the electrodes/separator and the transport distance of charged species can evolve due to mechanical deformation arising from either lithium intercalation-induced swelling and contraction of the active particles or externally applied mechanical loading. To describe accurately the coupling between mechanical deformation and the cell\u27s electrochemical response, we extend Newman\u27s DualFoil model to allow variable, non-uniform porosities in both electrodes and the separator, which are dynamically updated based on the electrochemical and mechanical states of the battery cell. In addition, the finite deformation theory from continuum mechanics is used to modify the electrochemical transport equations to account for the change of the charged species transport distance. The proposed coupled electrochemomechanical model is tested with a parameterized commercial cell. Our simulation results confirm that mass conservation is satisfied with the new formulation. We further show that mechanical effects have a significant impact on the cell\u27s electrochemical response at high charge/discharge rates

The Photochemical and Thermal Interconversion of Some Cyclopentadienone Dimers

In continuation of previous work on cyclopentadienone dimers [3], thermal and photochemical interconversions of the isomeric diketones 1, 3, and 5 by skeletal rearrangements have been established to the extent summarized in schemes 2 and 3, and the intramolecular [2+2] cycloaddition 1 → 2 was found to be reversible photochemically.</p

Late, but Not Early, Night Sleep Loss Compromises Neuroendocrine Appetite Regulation and the Desire for Food

Objective: There is evidence that reduced sleep duration increases hunger, appetite, and food intake, leading to metabolic diseases, such as type 2 diabetes and obesity. However, the impact of sleep timing, irrespective of its duration and on the regulation of hunger and appetite, is less clear. We aimed to evaluate the impact of sleep loss during the late vs. early part of the night on the regulation of hunger, appetite, and desire for food. Methods: Fifteen normal-weight ([mean ± SEM] body-mass index: 23.3 ± 0.4 kg/m2) healthy men were studied in a randomized, balanced, crossover design, including two conditions of sleep loss, i.e., 4 h sleep during the first night-half (‘late-night sleep loss’), 4 h sleep during the second night-half (‘early-night sleep loss’), and a control condition with 8h sleep (‘regular sleep’), respectively. Feelings of hunger and appetite were assessed through visual analogue scales, and plasma ghrelin and leptin were measured from blood samples taken before, during, and after night-time sleep. Results: Ghrelin and feelings of hunger and appetite, as well as the desire for food, were increased after ‘late-night sleep loss’, but not ‘early-night sleep loss’, whereas leptin remained unaffected by the timing of sleep loss. Conclusions: Our data indicate that timing of sleep restriction modulates the effects of acute sleep loss on ghrelin and appetite regulation in healthy men. ‘Late-night sleep loss’ might be a risk factor for metabolic diseases, such as obesity and type 2 diabetes. Thereby, our findings highlight the metabolic relevance of chronobiological sleep timing

Chronobiological aspects of sleep restriction modulate subsequent spontaneous physical activity

Purpose: First evidence suggests that chronobiological aspects of sleep restriction affect metabolic conditions. Our aim was to investigate whether spontaneous free-living physical activity likewise is affected by chronobiological timing of short sleep. Methods: In an experimental randomized, balanced cross-over design, eleven healthy, normal-weight (BMI: 23.9 +/- 0.4 kg/m(2)) men were evaluated. Physical activity was assessed by tri-axial wrist actigraphy after (i) four-hour sleep during the first night-half of the night ('late night sleep loss'), (ii) four-hour sleep during the second night-half ('early night sleep loss'), and (iii) eight-hour regular sleep ('regular sleep'), from 7:00 to 24:00 (17 h). Feelings of tiredness and activity were measured by semi-quantitative questionnaires. Results: Physical activity differed between sleep conditions (P < 0.05) with the lowest physical activity after 'late night sleep loss'. Accordingly, less time was spent in high-intensity physical activity after 'late night sleep loss' as compared to the 'early night sleep loss' and 'regular sleep' conditions (both P < 0.05). Perceived feelings of tiredness were higher after both short sleep conditions as compared to 'regular sleep' (both P < 0.05). Conclusions: Sleep restriction during the second half of the night elicits stronger effects on spontaneous physical activity than sleep restriction during the first half of the night despite identical sleep duration, but the impact of longer period awake needs to be evaluated in further research. In sum, these data indicate that not only short sleep per se but also chronobiological aspects modulate physical activity pattern.German Research Foundation (DFG) TR-SFB 654 TR-SFB 134 Federal Ministry of Education & Research (BMBF) 01G1092

Entwicklung eines hybriden Steuerungssystems zur rechnergestuetzten Prozessfuehrung von Abwasserreinigungsanlagen. Projektphase II: Leittechnische Implementierung und praktische Erprobung des Steuerungssystems in zwei Grossklaeranlagen Abschlussbericht

Die strikte Einhaltung der gesetzlich vorgegebenen Ueberwachungswerte fuer Klaeranlagen erfordert in zunehmendem Masse neben dem Einsatz leistungsfaehiger Klaerverfahren sowie einer ausreichenden Dimensionierung der Klaerstufen eine flexible, sich staendig an die wechselnden Belastungszustaende und Umgebungsbedingungen anpassende Prozessfuehrung einer Anlage. Aufgrund der starken tageszeit-, wochentags-, jahreszeit- und wetterabhaengigen Belastungsschwankungen von kommunalen Klaeranlagen kommt es je nach Auslastungsgrad der Anlage zu ausgepraegten kurzzeitigen bzw. laenger andauernden Schwankungen der Ablaufkonzentrationen. Hinsichtlich der Zielsetzung einer staerker automatisierten und optimierten Prozessfuehrung in der kommunalen Abwasserreinigung fanden in den letzten Jahren verschiedene Veraenderungen und Weiterentwicklungen statt, die neue und erfolgversprechende Ansaetze fuer eine weitgehende rechnergestuetzte Prozessfuehrung ermoeglichen und daher entsprechende Anstrengungen verstaerken. Ziel des Vorhabens war die Umsetzung, d.h. die Anpassung, Implementierung und Erprobung eines in der ersten Projektphase entwickelten ganzheitlichen Regelungskonzepts. Die Umsetzung sollte in zwei grosstechnischen, gut ausgelasteten kommunalen Klaeranlagen mit unterschiedlichen Verfahrenskonzepten mit Hilfe der fachlichen und finanziellen Beteiligung der Anlagenbetreiber erfolgen, die eine Realisierung des entwickelten Konzepts erst ermoeglichte. (orig.)The project focused on the adaptation, implementation and testing of an integrated control concept developed in the first project phase. The concept was to be implemented in two industrial-scale sewage systems with different technological concepts, in cooperation with the sewage plant operators. (orig.)SIGLEAvailable from TIB Hannover / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Bildung und Forschung (BMBF), Bonn (Germany)DEGerman