Adaptive temperature limits for air-conditioned museums in temperate climates

Indoor temperature (T) and relative humidity (RH) are important for collection preservation and thermal comfort in museums. In the 20th century, the notion evolved that T and RH need to be stringently controlled, often resulting in excessive energy consumption. However, recent studies have shown that controlled fluctuations are permissible, enabling improved energy efficiency. Consequently, the thermal comfort requirements are increasingly important to determine temperature limits, but knowledge is limited. Therefore, a thermal comfort survey study and indoor measurements were conducted at Hermitage Amsterdam museum in Amsterdam, the Netherlands for one year, including: (1) monitoring of existing conditions (T = 21°C, RH = 50%); and (2) an intervention in which T is controlled based on an adaptive comfort approach (T = 19.5–24°C, RH = 50%). The results show that the thermal comfort of the existing conditions is far from optimum; visitors feel too cool in summer and slightly too warm in winter. The adaptive temperature limits were developed to improve thermal comfort significantly without endangering the collection, thereby saving energy. Furthermore, facilitating visitors to adapt their clothing may contribute to enlarging the temperature bandwidth and improve (individual) thermal comfort.</p

Energy impact of ASHRAE’s museum climate classes : a simulation study on four museums with different quality of envelopes

ASHRAE's indoor climate design classes for general museums, galleries, archives and libraries are well known: AA (most strict), A, B, C and D (least strict). Museum staff often select class AA, presuming to gain the best overall preservation result that is possible. However, the exact consequences on the energy demand are unknown and therefore barely taken into account when selecting a class. This study quantifies the energy demand of four museum zones with different quality of envelopes (ranging from historical to state-of-the-art museum envelopes), conditioned according to ASHRAE's climate classes. The lower and upper limits of indoor temperature and relative humidity, and the resulting energy demand are determined using building simulations. The conclusions: (i) conditioning according to class B significantly saves energy compared to class A, while class B is still considered as precision control and protects most artefacts; (ii) moving down one class, e.g. from class AA to A, saves relatively more energy for a state-of-the-art building than for a historical building; (iii) Subclasses Ad (larger daily fluctuations) and As (seasonal adjustments, but smaller daily fluctuations) pose the same risk on the collection, but subclass Ad requires less humidification and dehumidification than As, so larger daily fluctuations may be preferred above seasonal adjustments

Inverse modeling to predict and characterize indoor climates

Computational research on monumental buildings yields three problems regarding current building models: tedious modelling, relatively long simulation times, difficult to characterize the building by models parameters. A simplified building model with physical meaning is developed which is capable of simulating indoor temperature and humidity. The parameters of the model are identified by an optimization algorithm which fits the output of the model to measurements. The method consisted of: developing simplified building models based on insights from a literature review; fitting the models to a 17th century castle’s indoor climate; based on three criteria the best performing model is chosen and validated. The validation consisted of: residual analysis; applying the chosen model to a 16th century Cathedral, a parameter analysis. Concluding: inverse modelling is applied successfully to reproduce the free floating indoor climate of monumental buildings; characterization of the building remains a challenge

Inverse modeling to predict and characterize indoor climates

Computational research on monumental buildings yields three problems regarding current building models: tedious modelling, relatively long simulation times, difficult to characterize the building by models parameters. A simplified building model with physical meaning is developed which is capable of simulating indoor temperature and humidity. The parameters of the model are identified by an optimization algorithm which fits the output of the model to measurements. The method consisted of: developing simplified building models based on insights from a literature review; fitting the models to a 17th century castle’s indoor climate; based on three criteria the best performing model is chosen and validated. The validation consisted of: residual analysis; applying the chosen model to a 16th century Cathedral, a parameter analysis. Concluding: inverse modelling is applied successfully to reproduce the free floating indoor climate of monumental buildings; characterization of the building remains a challenge

High resolution analysis of proteome dynamics during <i>bacillus subtilis</i> sporulation

Bacillus subtilis vegetative cells switch to sporulation upon nutrient limitation. To investigate the proteome dynamics during sporulation, high-resolution time-lapse proteomics was performed in a cell population that was induced to sporulate synchronously. Here, we are the first to comprehensively investigate the changeover of sporulation regulatory proteins, coat proteins, and other proteins involved in sporulation and spore biogenesis. Protein co-expression analysis revealed four co-expressed modules (termed blue, brown, green, and yellow). Modules brown and green are upregulated during sporulation and contain proteins associated with sporulation. Module blue is negatively correlated with modules brown and green, containing ribosomal and metabolic proteins. Finally, module yellow shows co-expression with the three other modules. Notably, several proteins not belonging to any of the known transcription regulons were identified as co-expressed with modules brown and green, and might also play roles during sporulation. Finally, levels of some coat proteins, for example morphogenetic coat proteins, decreased late in sporulation

Entwicklung einer App zur Leseverfolgung auf Mobilgeräten

Lesen fördert unsere sprachlichen und kognitiven Fähigkeiten und ist ein wichtiger Bestandteil der modernen Gesellschaft. Dabei hat sich die Art und Weise wie wir lesen durch die allgemeine Verfügbarkeit digitaler Geräte über die letzten 20 Jahre massiv verändert. Ziel dieser Arbeit war es ein System zu konzipieren, welches den Benutzer dabei unterstützt den Überblick darüber zu bewahren, was er alles in digitaler Form gelesen hat und ihn dabei zu unterstützen es auch im Gedächtnis zu behalten. Das konzipierte System besteht aus zwei Komponenten: Dem Reading Tracker und dem Reading Archive. Der Reading Tracker ist eine Android App, welche alle vom Benutzer gelesenen Texte an das Reading Archive überträgt. Das Reading Archive bewahrt diese auf und sorgt dafür, dass der Benutzer diese durchsuchen kann. Zusätzlich werden dem Benutzer verschiedene Metriken über sein Leseverhalten angezeigt. Das Reading Archive ist dabei eine in Django realisierte Webseite, die in der Android-App eingebunden wird. Die Funktionalität und Wirkung dieses Systems wurde anschließend durch eine Benutzerstudie überprüft und deren Ergebnisse diskutiert

From semiclassical transport to quantum Hall effect under low-field Landau quantization

The crossover from the semiclassical transport to quantum Hall effect is studied by examining a two-dimensional electron system in an AlGaAs/GaAs heterostructure. By probing the magneto-oscillations, it is shown that the semiclassical Shubnikov-de Haas (SdH) formulation can be valid even when the minima of the longitudinal resistivity approach zero. The extension of the applicable range of the SdH theory could be due to the damping effects resulting from disorder and temperature. Moreover, we observed plateau-plateau transition like behavior with such an extension. From our study, it is important to include the positive magnetoresistance to refine the SdH theory.Comment: 11 pages, 5 figure