Search results for "position"
showing 10 items of 6771 documents
Impact of the terrestrial reference frame on the determination of the celestial reference frame.
2022
Currently three up-to-date Terrestrial Reference Frames (TRF) are available, the ITRF2014 from IGN, the DTRF2014 from DGFI-TUM, and JTRF2014 from JPL. All use the identical input data of space-geodetic station positions and Earth orientation parameters, but the concept of combining these data is fundamentally different. The IGN approach is based on the combination of technique solutions, while the DGFI is combining the normal equation systems. Both yield in reference epoch coordinates and velocities for a global set of stations. JPL uses a Kalman filter approach, realizing a TRF through weekly time series of geocentric coordinates. As the determination of the CRF is not independent of the T…
Blueprint for a minimal photoautotrophic cell: conserved and variable genes in Synechococcus elongatus PCC 7942.
2011
This is an Open Access article distributed under the terms of the Creative Commons Attribution License.-- et al.
Erratum for Piwosz et al., "Light and Primary Production Shape Bacterial Activity and Community Composition of Aerobic Anoxygenic Phototrophic Bacter…
2020
Metabolic coupling between phytoplankton and bacteria determines the fate of dissolved organic carbon in aquatic environments, and yet how changes in the rate of primary production affect the bacterial activity and community composition remains understudied. Here, we experimentally limited the rate of primary production either by lowering light intensity or by adding a photosynthesis inhibitor. The induced decrease had a greater influence on bacterial respiration than on bacterial production and growth rate, especially at an optimal light intensity. This suggests that changes in primary production drive bacterial activity, but the effect on carbon flow may be mitigated by increased bacteria…
Social orphanhood in Latvia
2014
The reform processes and the developments of social policy to solve the major social problems of the socially vulnerable population, among them, children in particular, take place in Latvia during the last 20 years. Protection of children rights is declared one of the strategic priorities of the state social policy. At the same time the problem of child neglect and child abandonment in Latvia has not yet been sufficiently conceptualized. Already since 1990-ies Latvian society has clearly faced with an objective necessity of solving problems of child abandonment in connection with an increasing number of social orphans. The situation was complicated by the fact that the formation of a fundam…
«A/traverso» la transizione. Le pratiche culturali del movimento del ’77 e il paradigma artistico
2012
Il cosiddetto movimento del ’77, già negli anni della sua emersione ricondotto alle esperienze delle avanguardie artistiche del primo Novecento, riconfigurò i dispositivi di produzione-fruizione della cultura producendo un capovolgimento – orientato verso l’autorappresentazione politica dell’emergente proletariato giovanile – delle tradizionali categorie e mediazioni sociali ancora agenti nella società fordista.
Strategies for Improving Optimal Positioning of Quality Sensors in Urban Drainage Systems for Non-Conservative Contaminants
2021
In the urban drainage sector, the problem of polluting discharges in sewers may act on the proper functioning of the sewer system, on the wastewater treatment plant reliability and on the receiving water body preservation. Therefore, the implementation of a chemical monitoring network is necessary to promptly detect and contain the event of contamination. Sensor location is usually an optimization exercise that is based on probabilistic or black-box methods and their efficiency is usually dependent on the initial assumption made on possible eligibility of nodes to become a monitoring point. It is a common practice to establish an initial non-informative assumption by considering all network…
Evidencias de un recubrimiento de magnetita artificial en el armamento íbero
2011
A metallographic study of two pre-roman Iberian arms, affected by a cremation process, revealed the presence of an outer magnetite layer, providing highly protective properties. This layer is extraordinarily tenacious and of very homogeneous thickness, indicating an intentional manufacturing process rather than an accidental formation during the severe heating/cooling cycles the artefact suffered. Up to date, the intentional production of these types of layers has been attributed to a welding process of three different metallic sheets, here an alternative model is proposed, allowing, as could be simulated in the laboratory, the virtually exclusive formation of a magnetite coating.<br>…
Surface Morphology of Single and Multi-Layer Silicon Nitride Dielectric Nano-Coatings on Silicon Dioxide and Polycrystalline Silicon
2019
Silicon nitride (Si3N4) in a form of single and multi-layer nanofilms is proposed to be used as a dielectric layer in nanocapacitors for operation in harsh environmental conditions. Characterization of surface morphology, roughness and chemical bonds of the Si3N4 coatings has an important role in production process as the surface morphology affects the contact surface with other components of the produced device. Si3N4 was synthesized by using low pressure chemical vapour deposition method and depositing single and multi-layer (3 – 5 layers) nanofilms on SiO2 and polycrystalline silicon (PolySi). The total thickness of the synthesized nanofilms was 20 – 60 nm. Surface morphology was investi…
Growth and Electrochemical Performance of Lead and Lead Oxide Nanowire Arrays as Electrodes for Lead-Acid Batteries
2013
n this work, we present the growth and electrochemical performance of nanostructured lead and lead oxide electrodes for lead-acid batteries. The electrodes were obtained by template electrodeposition in polycarbonate membranes, acting as template. Electrochemical tests were conducted at constant current in 5M aqueous solution of sulphuric acid, after assembling nanostructured lead and lead oxide electrodes in a zero-gap configuration using a commercially available separator. The main advantages of these electrodes are the high specific energy and power density, and the wide surface area, about 70 times higher than the geometrical one. These features allowed high discharge rates, up to 20C. …
Antecedents of daily team job crafting
2017
This study investigated potential antecedents of team job crafting defined as the extent to which team members engage together in increasing (social and structural) job resources and challenges, and decreasing hindering job demands. Mindful of the teamwork literature, we hypothesized that individual employee factors (self-efficacy for teamwork, daily affect), team features (team cohesion, climate) and the organizational context of teams (engaging leadership and organizational resources for teamwork) relate positively to daily team job crafting behaviour. Data were collected among 46 multi-professional rehabilitation teams whose members completed two daily surveys after their weekly meetings…