Production de biogaz par les exploitations agricoles en Allemagne

L’Allemagne est un leader mondial dans le domaine de la méthanisation. Cela est du au fait que le pays, dans sa volonté d’abandonner l’énergie nucléaire, a énormément valorisé la recherche en nouvelles technologies pour les énergies renouvelables. Quelles sont ces découvertes ? Un système de rémunération visant à encourager le développement de la méthanisation a également été installé. Quels en sont les effets

Optimierung der informationellen Infrastruktur für die wissenschaftliche Kommunikation

Die Arbeit beschreibt, wie die wissenschaftliche Kommunikation durch den Einsatz elektronischer Publikationen verbessert werden kann und welche Anforderungen sich daraus an die zugrundeliegende Infrastruktur ergeben. Ausgehend von der wissenschaftlichen Fachzeitschrift werden dabei diejenigen Problemfelder besprochen, die eine Transformation von gedruckten Publikationen zu elektronisch verfügbaren Publikationen mit sich bringen. Ausgehend von den Problembereichen und den Mehrwertfunktionen von elektronischen Publikationen wird ein Szenario für eine optimierte wissenschaftliche Kommunikation über das Internet entworfen. Dem Szenario werden konkrete Lösungen aus Forschung und Praxis gegenübergestellt, und es wird untersucht, inwiefern die einzelnen Komponenten des Szenarios mit verfügbaren Technologien realisierbar sind. Der Schwerpunkt der Arbeit liegt auf der technischen Infrastruktur, die für eine effektive wissenschaftliche Kommunikation über das Internet notwendig ist. Die ökonomischen, rechtlichen und sozialen Implikationen eines Übergangs von gedruckten zu elektronischen Publikationen werden dabei nur gestreift

Optimierung der informationellen Infrastruktur für die wissenschaftliche Kommunikation

Die Arbeit beschreibt, wie die wissenschaftliche Kommunikation durch den Einsatz elektronischer Publikationen verbessert werden kann und welche Anforderungen sich daraus an die zugrundeliegende Infrastruktur ergeben. Ausgehend von der wissenschaftlichen Fachzeitschrift werden dabei diejenigen Problemfelder besprochen, die eine Transformation von gedruckten Publikationen zu elektronisch verfügbaren Publikationen mit sich bringen. Ausgehend von den Problembereichen und den Mehrwertfunktionen von elektronischen Publikationen wird ein Szenario für eine optimierte wissenschaftliche Kommunikation über das Internet entworfen. Dem Szenario werden konkrete Lösungen aus Forschung und Praxis gegenübergestellt, und es wird untersucht, inwiefern die einzelnen Komponenten des Szenarios mit verfügbaren Technologien realisierbar sind. Der Schwerpunkt der Arbeit liegt auf der technischen Infrastruktur, die für eine effektive wissenschaftliche Kommunikation über das Internet notwendig ist. Die ökonomischen, rechtlichen und sozialen Implikationen eines Übergangs von gedruckten zu elektronischen Publikationen werden dabei nur gestreift

Characterization of wood-adhesive bonds in wet conditions by means of nanoindentation and tensile shear strength

The performance of adhesive-hardwood bonds can often be sensitive to humidity and temperature variation. Therefore, it is frequently challenging to achieve standard requirements for structural applications. To gain a better understanding of the wood-adhesive bond, the properties of the individual constituents as well as the local interface of European beech (Fagus sylvatica L.) wood cell walls in contact with structural adhesives were analyzed by means of nanoindentation. These results are compared to classical lap-shear strength. As adhesives two different one-component polyurethane adhesives (1C PUR) and a phenol resorcinol formaldehyde adhesive (PRF) were used. In one case, the beech wood was additionally pre-treated with an adhesion-promoting agent (primer) prior to bonding with 1C PUR. Beech wood joints were analyzed subsequent to several treatments, namely standard climate, after wet storage and in re-dried conditions. In addition, the influence of the primer on the hydroxyl accessibility of beech wood was investigated with dynamic vapor sorption (DVS). The lap-shear strength revealed good performance in dry and re-dried conditions for all adhesives on beech. Both polyurethane adhesives obtained deficits when tested in wet conditions. The use of a primer significantly improved the PUR performance in wet condition. DVS experiment demonstrated a decrease in hydroxyl group accessibility when using a high primer concentration. As novelty, nanoindentation was used for the first time to characterize the local wood–adhesive-interface properties in wet conditions. Nanoindentation showed that all tested 1C PUR perform quite similar in room climate, while PRF achieves considerable higher values for reduced E-modulus and hardness. Wet storage led to a considerable reduction in mechanical properties for all adhesives, while the highest relative change was observed for PRF. After re-drying, the adhesives re-gained a large part of their original mechanical properties in room climate. No distinct effect of the primer on the local micromechanical properties could be detected with nanoindentation in terms of specific work of indentation

RO-Crate community update 2024

Here we give an update of the community development and adoption of RO-Crate for FAIR Digital Object since FDO2022. It is notable that programmatic access and more detailed profiles have received high attention, as well as several FDO implementations that use RO-Crate

Modifying elastic modulus of two-component polyurethane adhesive for structural hardwood bonding

Subject to this study is the modification of an experimental two-component polyurethane (2C PUR) as an alternative adhesive for structural hardwood bonding. The 2C PUR has been adapted by calcium carbonate as filler to increase its modulus of elasticity with the aim of increasing the modulus analogue to the ones typically observed for classic amino- and phenol based adhesives. The 2C PUR system was compared with a commercial one-component polyurethane (1C PUR) and a phenol resorcinol formaldehyde (PRF) adhesive. The wetting properties of the adhesives were tested in terms of surface tension, polar and dispersive part and contact angle on European beech wood ( Fagus sylvatica L.). In addition, adhesive polymer films of 2C PUR were tested for tensile strength and modulus of elasticity (E-Modulus) following ISO 527-1. The adhesives bond performance on beech wood was determined by lap-joints according to EN 302-1 in various climate conditions. The results show that 2C PUR has proper wettability properties on beech wood. Adding 60% wt filler to the polyol component increased the E-Modulus from 2.3 GPa (0%) to 4.4 GPa. The tensile strength of the modified 2C PUR polymer films was comparable with the industrial 1C PUR. Tensile shear strength and wood failure percentage of 2C PUR lap-joints were increased by adding filler and met requirements in dry and re-dried conditions according to EN 302-1. However, the addition of filler didn’t result in an improvement in wet conditions. The present study shows sufficient performance for bonding hardwood with 2C PUR in dry conditions, while the system still needs to be improvement regarding its performance in humid conditions

Influence of site characteristics on the performance of shallow borehole heat exchanger arrays: A sensitivity analysis

Using borehole heat exchangers (BHE) to extract shallow geothermal energy has grown rapidly in recent years. How to maintain a long-term balanced, sustainable operation of the BHE arrays becomes a key issue. Site characteristics, including hydrogeological and geothermal conditions as well as spatial distribution of subsurface physical parameters, are generally idealized or partly neglected in practice. To investigate the consequences of such simplifications, a 3D model, based on data from a planned real site, is established to consider groundwater flow, subsurface heterogeneity, and various hydrogeothermal boundary conditions. After verifying the model, a sensitivity analysis is conducted. Nine factors regarding site characteristics are selected, including Darcy flux in the aquifer, thermal conductivity and volumetric heat capacity of the ground, groundwater depth, thermal and hydraulic heterogeneity, geothermal gradient, heat transfer coefficient on the ground surface and seasonal rainfall. Sensitivity results indicate that the annual total heat production is most sensitive to geothermal gradient, followed by Darcy flux, both of which have positive effects. Groundwater depth and heat transfer coefficient have negative effects on annual heat production. Compared to thermal heterogeneity and rainfall, the influence of hydraulic heterogeneity is higher. Uncertainty of annual heat production due to various Peclet numbers is quantified through regression analysis

Dermatofibrosarcoma protuberans: Surgical excision versus Mohs surgery

The purpose of this project was to compare the recurrence rates of dermatofibrsarcoma protuberans (DFSP) treated with surgical excision (SE) and Mohs surgery (MS) at Yale. Patients were identified through the dermatopathology laboratory database and stratified by treatment. The following information was collected: age at onset, sex, disease state (primary presentation versus recurrence), tumor site, preoperative tumor size, postoperative defect size, excisional margin, duration of follow-up, and recurrence after treatment. Of the 30 patients, 14 were in the SE group, and 16 were in the MS group. There were no recurrences in the SE group, and there was 1 recurrence (6%) in the MS group, which occurred 37 months post-operatively. The average area of the tumors were 12.1 cm2 ± 16.1 (SE) and 5.3 cm2 ± 5.9 (MS), and the mean excisional margins were 3.8 cm ± 1.6 (SE) and 1.4 cm± 0.5 (MS). The mean duration of follow-up in the SE group was 33 months ± 41 (range: 1-116 months), and the mean duration of follow-up in the MS group was 26 months ± 25 (range: 2 to 69 months.) Although the MS group had a higher recurrence rate than the SE group, using the recurrence rates to make meaningful conclusions about the efficacy of the two treatment modalities is limited by the small n, lack of randomization to either procedure, and duration of follow-up. Once these issues are addressed, recurrence rates must also be adjusted for patient and tumor characteristics, that are associated with higher recurrence rates