Optimisation of hybrid off-grid energy systems by linear programming

Background: In this study, a general model of a hybrid off-grid energy system is developed, which can be adjusted to reflect real conditions in order to achieve economical and ecological optimisation of off-grid energy systems. Methods: Using linear programming methods in the General Algebraic Modeling System (GAMS) environment, the optimal configuration of the electrical power supply system following characteristic restrictions as well as hourly weather and demand data is found. From this model, the optimal mix of solar- and wind-based power generators combined with storage devices and a diesel generator set is formed. Results: The operation of this model was tested in two real off-grid energy systems, a cluster of villages in India and Titumate in Colombia. Both optimisation processes resulted in hybrid energy systems, utilising photovoltaics (PV), lead-acid batteries and a diesel generator as a load-balancing facility. Conclusions: With respect to small off-grid energy systems, it was found that renewable energy in combination with electrical storage devices help to reduce the cost of energy compared to stand-alone diesel generator sets. The optimal solutions strongly depend on the particular load demand curve. As both PV and wind energy benefit from energy storage, the costs of the battery can be shared and the two technologies complement each other. Finally, although the optimised capacity of the diesel generator remains nearly constant, its contribution to the total power generation is being substituted by renewable energy sources, which serve as fuel-saving technologies

Wurzeln und Wasser – Gesunde Pflanzen in der Schwammstadt: Bericht über die VIII. Urbane Pflanzen Konferenz „Wie funktioniert Stadtgrün besser?“, 25. September 2023, Universität Göttingen

Ein Weg, Städte an den Klimawandel anzupassen, ist die Umsetzung des Prinzips der „Schwammstadt“. Überflutungen durch Starkregen und Trockenheit durch Hitzeperioden soll durch phytotechnische und naturbasierte Maßnahmen entgegengewirkt werden. Die Stadt soll die Fähigkeit bekommen, große Mengen an plötzlich auftretendem Wasser aufzusaugen, dieses Wasser zu speichern und es dann durch Verdunstung und gezielte Bewässerung wieder abzugeben. Doch wie reagieren Pflanzen, wenn ihre Wurzeln überstaut werden? Wie lange darf ein solcher Zustand währen? Wie sollte die Kontaktzone zwischen Wurzelraum und gespeichertem Wasser gestaltet werden? Fördert man durch die Schwammstadt bodenbürtige Schaderreger der Wurzeln? Wie wirken sich Schadstofffrachten im Wasser auf die Pflanzengesundheit aus? Müssen wir besondere Pflanzen auswählen, die an den Wechsel von einem Zuviel zu einem Zuwenig an Wasser angepasst sind? Diesen Fragen ging die Tagung in Vorträgen und gemeinsamem Austausch nach

From Lab to Pilot Scale: Commissioning of an Integrated Device for the Generation of Crystals

Fast time-to-market, increased efficiency, and flexibility of production processes are major motivators for the development of integrated, continuous apparatuses with short changeover times. Following this trend, the modular belt crystallizer was developed and characterized in lab scale with the model system sucrose-water. Based on the promising results, the plant concept was upscaled and commissioned in industrial environment. The results are presented within the scope of this work. Starting from small seed crystals in solution, it was possible to grow, separate, and dry product particles. Further, the conducted experiments demonstrated that it is feasible to transfer the results from laboratory to pilot scale, which in turn enables accelerated process design as well as development

Natural and cryptic peptides dominate the immunopeptidome of atypical teratoid rhabdoid tumors

BACKGROUND: Atypical teratoid/rhabdoid tumors (AT/RT) are highly aggressive CNS tumors of infancy and early childhood. Hallmark is the surprisingly simple genome with inactivating mutations or deletions in the SMARCB1 gene as the oncogenic driver. Nevertheless, AT/RTs are infiltrated by immune cells and even clonally expanded T cells. However, it is unclear which epitopes T cells might recognize on AT/RT cells. METHODS: Here, we report a comprehensive mass spectrometry (MS)-based analysis of naturally presented human leukocyte antigen (HLA) class I and class II ligands on 23 AT/RTs. MS data were validated by matching with a human proteome dataset and exclusion of peptides that are part of the human benignome. Cryptic peptide ligands were identified using Peptide-PRISM. RESULTS: Comparative HLA ligandome analysis of the HLA ligandome revealed 55 class I and 139 class II tumor-exclusive peptides. No peptide originated from the SMARCB1 region. In addition, 61 HLA class I tumor-exclusive peptide sequences derived from non-canonically translated proteins. Combination of peptides from natural and cryptic class I and class II origin gave optimal representation of tumor cell compartments. Substantial overlap existed with the cryptic immunopeptidome of glioblastomas, but no concordance was found with extracranial tumors. More than 80% of AT/RT exclusive peptides were able to successfully prime CD8(+) T cells, whereas naturally occurring memory responses in AT/RT patients could only be detected for class II epitopes. Interestingly, >50% of AT/RT exclusive class II ligands were also recognized by T cells from glioblastoma patients but not from healthy donors. CONCLUSIONS: These findings highlight that AT/RTs, potentially paradigmatic for other pediatric tumors with a low mutational load, present a variety of highly immunogenic HLA class I and class II peptides from canonical as well as non-canonical protein sources. Inclusion of such cryptic peptides into therapeutic vaccines would enable an optimized mapping of the tumor cell surface, thereby reducing the likelihood of immune evasion

Empirische Religionspädagogik und Praktische Theologie : Metareflexionen, innovative Forschungsmethoden und aktuelle Befunde aus Projekten der Sektion „Empirische Religionspädagogik“ der AKRK

Der Sammelband stellt in insgesamt 20 Beiträgen Metareflexionen, innovative Forschungsmethoden und aktuelle Befunde aus Projekten der AKRK-Sektion "Empirische Religionspädagogik" vor. 19 Autorinnen und Autoren aus verschiedenen Ländern und Sparten der Theologie haben hieran mitgewirkt, auch um weitere empirisch fundierte Forschungsarbeiten anzuregen

The association between leukocytes and sperm quality is concentration dependent

<p>Abstract</p> <p>Background</p> <p>To evaluate the association between leukocytes (polymorphonuclear granulocytes -PMNL) and semen parameters at different leukocyte concentrations.</p> <p>Methods</p> <p>This was a retrospective clinical study at a university hospital andrology clinic. Semen samples from infertile men were analyzed for sperm morphology and motility according to seminal leukocytes (PMNL) concentration (category A: >0 to <0.25 × 10(6)/mL; category B: >0.25 to <0.5 × 10(6)/mL; category C: >0.5 to <0.75 × 10(6)/mL; category D: >0.75 to <1.0 × 10(6)/mL, category E: >1 × 10(6)/mL).</p> <p>Results</p> <p>The percentage of sperm with normal morphology increased significantly from category A (14%) to category D (19%) but decreased in category E to levels (14%) similar to those in category A. Motility grades a and a+b (combined) also increased from category A (12%, 20%) to category D (18.0%, 28.5%) and decreased in category E (11%, 20.5%) to levels similar to those in category A. Sperm deformities and motility grades c and d increased progressively in all categories.</p> <p>Summary</p> <p>Leukocytes had a positive association with normal morphology and progressive motility in semen samples at a concentration of 0-1 × 10(6)/mL. The findings suggest that the association between leukocytes (PMNL) and semen quality might be concentration dependent.</p

Opening up design science: The challenge of designing for reuse and joint development

The purpose of this paper is to advance design science by developing a framework for research on reuse and the relationship between external IT artifacts and their users. A design science approach to IS research needs to grapple with the fact that a number of relevant, economically attractive, external IT artifacts cannot be designed from scratch nor meaningfully evaluated based on the current state of development, and so design science research will struggle with incomplete cycles of design, relevance, and rigor. We suggest a strategic research agenda that integrates the design of the relationship between an external IT artifact and the user by considering the impact artifacts exert on users. Three dimensions derived from adaptive structuration theory inform our framework on three levels of design granularity (middle management, top management, and entrepreneur): agenda considers the dynamic properties of technological objects, adaptability refers to the functional affordance of external artifacts in development, and auspice captures the symbolic expression and scope for interpretation. We derive implications for research design