Industrial Freeform Generation of Microtools by Laser Micro Sintering

Precision tools with structural resolution reaching the 20 micrometer range can be generated on an industrial scale by “laser micro sintering”. Components featuring aspect ratios above 12 and a roughness Ra down to 1.5 micrometers have already been produced from sub micrometer grained metal powders. The components can be generated either firmly attached to a substrate or fixed in an easily separable mode. If supporting structures are employed, undercuts up to 90° are feasible, without, a process parameter dependent maximum angles of undercut below 90° are obtained. The process has been introduced into the market, labeled microSINTERING by 3D-Micromac AG.Mechanical Engineerin

Principles of Laser Micro Sintering

Laser Micro Sintering was introduced to the international community of freeform fabrication engineers in 2003 and has since been employed for a variety of applications. It owes its unique features to certain effects of q-switched pulses that formerly had been considered detrimental in selective laser sintering. Besides sub-micrometer sized powders also materials with grain sizes of 1-10 micrometers can be sintered. Surface and morphology of the product are influenced by grain size and process environment. First results have been achieved with processing ceramic materials. A comprehensive overview of the process and the features is given supported by experimental evidence. Routes of further development are indicated.Mechanical Engineerin

In-Vitro Evaluation of Resistance to Late Blight (Phytophthora infestans Mont. De Bary.) in Solanum Accessions Native to Chile, by Inoculation of Detached Leaflets

Abstract The objective of the present study was to evaluate the resistance of 10 accessions to P. infestans, by in-vitro inoculation of detached leaflets with a complex isolation of the fungus. Late blight, caused by the fungus Phytophthora infestans Mont. De Bary, is one of the most important diseases of the potato crop, and can destroy complete plantations in a short space of time. Chile is considered as a sub-centre of the origin of cultivated potatoes with many native potato varieties in the country. The different resistance components demonstrated that within the material of Chilean native Solanum, there was a wide range of variation to late blight. The resistant control (R-8906384) and the accessions UCT-34-Cor presented the lowest infection efficiency, small sizes of the lesions and low levels of sporulation classifying them as the most resistant. This suggests low efficiency of the infection and high resistance to penetration in these materials. The more susceptible accessions often presented a good level of resistance for one or few components. It would be of great interest to go into the genetic control of the different resistance components to know if the same level of resistance expressed for a component by different accessions is under the same genetic control or not

Spatial and temporal occurrence of bats in the southern North Sea area

Since a few years it is known that bats migrate over sea on a regular basis. As numerous land-based studies have shown that wind turbines can cause high fatality rates amongst bats Rijkswaterstaat started a bat monitoring programme for 2015 and 2016 in order to reduce uncertainties about possible impacts. At the same time Eneco commissioned a bat monitoring programme for 2015 and 2016 as part of the Monitoring and Evaluation Programme (MEP) for the offshore windfarm Luchterduinen. In 2016 Gemini conducted a bat monitoring campaign in windfarm Buitengaats and Wageningen Marine Research executed a bat monitoring programme at Wintershall platform P6-A and offshore research station FINO3 in the same year. The joint monitoring effort included 12 different offshore locations and 5 locations at the coast. The specific aims of these monitoring programmes are an assessment of : 1. The species composition at sea and at the coast. 2. The spatiotemporal pattern of occurrence, including the flight height. 3. The relation between environmental conditions and the occurrence of bats. 4. The function of the Dutch Territorial Sea for bats. The monitoring results at the coast showed that Nathusius’ pipistrelle is very common during both spring and autumn migration, but is also regular throughout the summer. It is also the most frequently recorded species at sea, albeit much less frequently recorded in comparison to the coast. At sea it was recorded from late August until late October (and one observation in November), and –to a lesser extent- from early April until the end of June. There were no records in July until mid-August. The observed pattern of occurrence matches previous offshore monitoring studies in the German and Dutch North Sea

L’instruction en famille en Suisse romande : portrait des familles et motivations parentales

L'instruction en famille est une option éducative peu connue, mais en développement. Cette première enquête en Suisse romande documente les raisons de ce choix, les pratiques éducatives et le profil sociodémographique chez 137 familles. Les raisons exprimées par ces parents sont multiples et variées. Leurs principaux facteurs décisionnels sont d’ordre social ou pédagogique: une critique de la motivation et de la socialisation en contexte scolaire, la recherche d’un enrichissement des relations familiales, un projet éducatif poursuivi sous la responsabilité parentale, et une critique des programmes d’études cantonaux et des méthodes pédagogiques de l’école. Les résultats révèlent également des situations de souffrance infantile en milieu scolaire.Home education is a little-known but developing educational option. This first survey in French-speaking Switzerland documents the reasons for this choice, the educational practices and the socio-demographic profile of 137 families. The reasons expressed by these parents are many and varied. Their main decision-making factors are social or pedagogical: a critique of motivation and socialization in the school context, the search for enrichment of family relationships, an educational project pursued under parental responsibility, and a critique of cantonal educational programs and of school teaching methods. The results also reveal situations of childhood suffering in schools.Familienerziehung ist eine wenig bekannte, aber sich entwickelnde Bildungsoption. Diese erste Umfrage in der französischsprachigen Schweiz dokumentiert die Gründe für diese Wahl, die Bildungspraktiken und das soziodemografische Profil von 137 Familien. Die von diesen Eltern geäußerten Gründe sind vielfältig. Ihre Hauptentscheidungsfaktoren sind soziale oder pädagogische: eine Kritik der Motivation und Sozialisation im schulischen Kontext, die Suche nach einer Bereicherung familiärer Beziehungen, ein Bildungsprojekt, das unter elterlicher Verantwortung durchgeführt wird, und eine Kritik der Bildungsprogramme. kantonale Studien und Methoden des Schulunterrichts. Die Ergebnisse zeigen auch Situationen, in denen Kinder in Schulen leiden.L'educazione familiare è un'opzione educativa poco conosciuta ma in via di sviluppo. Questo primo sondaggio nella Svizzera romanda documenta le ragioni di questa scelta, le pratiche educative e il profilo socio-demografico di 137 famiglie. Le ragioni espresse da questi genitori sono molte e varie. I loro principali fattori decisionali sono sociali o pedagogici: una critica della motivazione e della socializzazione nel contesto scolastico, la ricerca di arricchimento delle relazioni familiari, un progetto educativo perseguito sotto la responsabilità genitoriale e una critica dei programmi educativi cantonali e metodi di insegnamento scolastico. I risultati rivelano anche situazioni di sofferenza infantile nelle scuole

All quiet on the sea bottom front? Lessons from the morphodynamic monitoring

The impact of the construction of the offshore wind farms on the turbidity was local and temporary, with no significant difference between the before and after situation. Erosion pits were formed, both around gravity based foundations and monopiles, though erosion protection provided the necessary stability. Dredging/filling works were more complex than expected. Large volumes of sand were lost and sand pits did not refill naturally. In dune migrating areas the coverage of export cables could not be guaranteed. As a result they are now buried 1 m below the base of the dunes

The ecology of infrastructure decommissioning in the North Sea: what we need to know and how to achieve it

As decommissioning of oil and gas (O&G) installations intensifies in the North Sea, and worldwide, debate rages regarding the fate of these novel habitats and their associated biota—a debate that has important implications for future decommissioning of offshore wind farms (OWFs). Calls to relax complete removal requirements in some circumstances and allow part of an O&G installation to be left in the marine environment are increasing. Yet knowledge regarding the biological communities that develop on these structures and their ecological role in the North Sea is currently insufficient to inform such decommissioning decisions. To focus debate regarding decommissioning policy and guide ecological research, we review environmental policy objectives in the region, summarize existing knowledge regarding ecological aspects of decommissioning for both O&G and OWF installations, and identify approaches to address knowledge gaps through science–industry collaboration. We find that in some cases complete removal will conflict with other policies regarding protection and restoration of reefs, as well as the conservation of species within the region. Key ecological considerations that are rarely considered during decommissioning decisions are: (i) provision of reef habitat, (ii) productivity of offshore ecosystems, (iii) enhancement of biodiversity, (iv) protection of the seabed from trawling, and (v) enhancement of connectivity. Knowledge gaps within these areas will best be addressed using industry infrastructure and vessels for scientific investigations, re-analysis of historical data held by industry, scientific training of industry personnel, joint research funding opportunities, and trial decommissioning projects

Aerial Measurement of Radioxenon Concentration off the West Coast of Vancouver Island following the Fukushima Reactor Accident

In response to the Fukushima nuclear reactor accident, on March 20th, 2011, Natural Resources Canada conducted aerial radiation surveys over water just off of the west coast of Vancouver Island. Dose-rate levels were found to be consistent with background radiation, however a clear signal due to Xe-133 was observed. Methods to extract Xe-133 count rates from the measured spectra, and to determine the corresponding Xe-133 volumetric concentration, were developed. The measurements indicate that Xe-133 concentrations on average lie in the range of 30 to 70 Bq/m3.Comment: 14 pages, 5 figures, accepted for publication in Journal of Environmental Radioactivit