210 research outputs found
Fabrication method of a low-loss plasmonic waveguide containing both plasmonic-friendly and plasmonic-unfriendly metals
Fabrication technology, which allows a substantial decrease of the plasmonic
propagation loss for both plasmon-friendly metals like Au, Cu or Al and
plasmon-unfriendly metals like Co, Fe or Cr, has been developed and
experimentally demonstrated. Optimization of the optical confinement is used to
reduce the propagation loss below 1 dB per plasmonic device.Comment: 7 pages, 10 figure
Planning and automatization of regarding production system as a part of ecological management
Trading wood for water and carbon in peatland forests? Rewetting is worth more than wood production
While traditional forest management systems aim at maximizing timber production, sustainable forest management focuses on the multiple benefits of entire forest landscapes. The latter is now at the top of policy agendas. This calls for learning through evaluation to support the implementation of policies aiming towards multi-functional forest landscapes. The aim of this study is to quantify the economic trade-offs among natural, current, and re-wetted peatland forests using seven indicators, viz. drainage maintenance, rewetting, water retention, wood production, and three types of carbon sequestration as economic indicators. We discuss ways to adapt to and mitigate effect of forest draining on climate change toward securing multi-functional forest landscapes. The cost benefit analysis showed that in a potential natural state, Lithuania's peatland forests would deliver an economic benefit of -euro176.1 million annually. In contrast, compared to natural peatland forests, the drainage of peatland forests for wood production has caused a loss of -euro309 million annually. In comparison, peatland forest rewetting is estimated to increase the economic value by -euro170 million annually. This study shows that satisfying different ecosystem services is a balancing act, and that a focus on wood production has resulted in net losses when foregone values of water storage and carbon sequestration are considered. Valuation of different sets of ecosystems service benefits and disservices must be assessed, and can be used as a tool towards creating, implementing and monitoring consequences of policies on both sustainability and biodiversity
Designing a light fabric metamaterial being highly macroscopically tough under directional extensio. First experimental evidence
In this paper, we study a metamaterial constructed with an isotropic material organized following a geometric structure which we call pantographic lattice. This relatively complex fabric was studied using a continuous model (which we call pantographic sheet) by Rivlin and Pipkin and includes two families of flexible fibers connected by internal pivots which are, in the reference configuration, orthogonal. A rectangular specimen having one side three times longer than the other is cut at 45° with respect to the fibers in reference configuration, and it is subjected to large-deformation plane-extension bias tests imposing a relative displacement of shorter sides. The continuum model used, the presented numerical models and the extraordinary advancements of the technology of 3D printing allowed for the design of some first experiments, whose preliminary results are shown and seem to be rather promising. Experimental evidence shows three distinct deformation regimes. In the first regime, the equilibrium total deformation energy depends quadratically on the relative displacement of terminal specimen sides: Applied resultant force depends linearly on relative displacement. In the second regime, the applied force varies nonlinearly on relative displacement, but the behavior remains elastic. In the third regime, damage phenomena start to occur until total failure, but the exerted resultant force continues to be increasing and reaches a value up to several times larger than the maximum shown in the linear regime before failure actually occurs. Moreover, the total energy needed to reach structural failure is larger than the maximum stored elastic energy. Finally, the volume occupied by the material in the fabric is a small fraction of the total volume, so that the ratio weight/resistance to extension is very advantageous. The results seem to require a refinement of the used theoretical and numerical methods to transform the presented concept into a promising technological prototype
Trading wood for water and carbon in peatland forests? Rewetting is worth more than wood production
While traditional forest management systems aim at maximizing timber production, sustainable forest management focuses on the multiple benefits of entire forest landscapes. The latter is now at the top of policy agendas. This calls for learning through evaluation to support the implementation of policies aiming towards multi-functional forest landscapes. The aim of this study is to quantify the economic trade-offs among natural, current, and re-wetted peatland forests using seven indicators, viz. drainage maintenance, rewetting, water retention, wood production, and three types of carbon sequestration as economic indicators. We discuss ways to adapt to and mitigate effect of forest draining on climate change toward securing multi-functional forest landscapes. The cost benefit analysis showed that in a potential natural state, Lithuania’s peatland forests would deliver an economic benefit of ~€176.1 million annually. In contrast, compared to natural peatland forests, the drainage of peatland forests for wood production has caused a loss of ~€309 million annually. In comparison, peatland forest rewetting is estimated to increase the economic value by ~€170 million annually. This study shows that satisfying different ecosystem services is a balancing act, and that a focus on wood production has resulted in net losses when foregone values of water storage and carbon sequestration are considered. Valuation of different sets of ecosystems service benefits and disservices must be assessed, and can be used as a tool towards
creating, implementing and monitoring consequences of policies on both sustainability and biodiversity.publishedVersio
Developing an empirical model for assessment of total nitrogen inflow to rivers and lakes in the Biebrza river watershed, Poland
Nitrogen load is crucial for its application in various fields such as agriculture and improving water quality control for authorities responsible for establishing agricultural policies in the area. The calculation of nitrogen load using existing equations is not applicable for all types of rivers, thus requiring the development of a new equation that can be applied to lakes and rivers in the Biebrza river catchment. To determine the new equation, extensive mapping of the catchment area was conducted, which was adjusted to precipitation and runoff in the area, allowing the observed results to be compared. Based on several analyses, the new equation has better accuracy, RMSE of the new model-based estimation decreased by 65.9% in 2005–2015 and 62.2% in 2016–2021 for river and 92% in 2008–2019 and 95% in 2020–2021 for lakes. Therefore, the application of the new calibrated empirical model provides results close to the real values and it can be used in the Biebrza river basin to simulate the total nitrogen runoff
- …