Search results for " Materials"
showing 10 items of 14487 documents
Highly Sensitive Polarization Rotation Measurement through a High‐Order Vector Beam Generated by a Metasurface
2020
The precise determination of the polarization state of light is fundamental for a vast variety of applications in remote sensing, astronomy, optics and terahertz technology, to name just a few. Typically, polarization characterization is performed by using a combination of multiple optical devices such as beam splitters, polarizers, and waveplates. Moreover, to achieve high-precision, balanced photodetectors and lock-in amplifiers are employed, thus contributing to increasing system complexity. Here, a technique for polarization rotation measurements with a dynamic range of 180° and a sensitivity of about 10−2 degrees is realized using a properly designed metasurface. Such device generates …
Stakeholder perceptions of wood-based products in the built environment : a literature review
2022
Current global environmental challenges, such as climate change, set an urge to seek renewable low-emission alternatives to substitute fossil fuel-derived products while transitioning towards circular bioeconomy. Wood has proven to be a versatile renewable material that is able to substitute fossil-based materials. However, the market potential and uptake of wood-based products is also dependent on the preferences of consumers and other stakeholder groups. This paper presents a systematic literature review of studies examining stakeholder perceptions of wood-based products, which also resulted in the identification of research gaps and suggestions for future research directions. The results…
Molecular Basis of SARS-CoV-2 Nsp1-Induced Immune Translational Shutdown as Revealed by All-Atom Simulations.
2021
The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic represents the most severe global health crisis in modern human history. One of the major SARS-CoV-2 virulence factors is nonstructural protein 1 (Nsp1), which, outcompeting with the binding of host mRNA to the human ribosome, triggers a translation shutdown of the host immune system. Here, microsecond-long all-atom simulations of the C-terminal portion of the SARS-CoV-2/SARS-CoV Nsp1 in complex with the 40S ribosome disclose that SARS-CoV-2 Nsp1 has evolved from its SARS-CoV ortholog to more effectively hijack the ribosome by undergoing a critical switch of Q/E158 and E/Q159 residues that perfects Nsp1's interactions…
The ALICE experiment at the CERN LHC
2008
Journal of Instrumentation 3(08), S08002 (2008). doi:10.1088/1748-0221/3/08/S08002
Development and characterisation of polymer composite materials with bio-inspired functions
2018
Promocijas darbs ir izstrādāts disertācijas veidā fizikas nozarē materiālu fizikas apakšnozarē. Pētījums tika veikts LU Materiālu mehānikas institūtā. Darbs saistīts ar aktuālu un jaunu pētījumu virzienu: bioinspirēto funkciju tālāku attīstīšanu slodzi nesošos kompozītos. Tās ir mehānisku triecienu vizuālās indikācijas un polimēru matricas vaskulārās pašdziedināšanas funkcijas. Šīs funkcijas tika nodrošinātas, izveidojot viedus slāņus un iebūvējot tos kompozītā. Pētījumā tika noskaidrotas piemērotās pārbaužu secības, attīstītas kvantitatīvas metodes un mehānisks modelis, lai novērtētu jauno funkciju efektivitāti kompozītos. Ir pierādīta funkciju augstā efektivitāte un spēja uzlabot slodzi n…
Procedures for study of teaching practices. Literature Review
2012
Interest in studying teaching practices has increased, because of the need to evaluate teachers and dissatisfaction with the usual ways of doing it. Recent approaches with Value-Added Models, based on students’ results on achievement tests do not seem satisfactory. The article is based on a review of literature and classifies the approaches to practices in three groups: instruments based on information given by teachers; observation protocols; and approaches based on the analysis of products of the practices. Specific tools are described and advantages and disadvantages of the three approaches are discussed. El interés por las prácticas docentes ha aumentado, en parte por la necesidad de ev…
Lidar detection of carbon dioxide in volcanic plumes
2015
Volcanic gases give information on magmatic processes. In particular, anomalous releases of carbon dioxide precede volcanic eruptions. Up to now, this gas has been measured in volcanic plumes with conventional measurements that imply the severe risks of local sampling and can last many hours. For these reasons and for the great advantages of laser sensing, the thorough development of volcanic lidar has been undertaken at the Diagnostics and Metrology Laboratory (UTAPRAD-DIM) of the Italian National Agency for New Technologies, Energy and Sustainable Economic Development (ENEA). In fact, lidar profiling allows one to scan remotely volcanic plumes in a fast and continuous way, and with high s…
Electrical conductivity of glass fiber-reinforced plastic with nanomodified matrix for damage diagnostic
2021
The electrical conductivity of glass fiber-reinforced plastic (GFRP) with epoxy matrix modified by multiwall carbon nanotubes (MWCNT) was studied. The electrical conductivity of nanomodified lamina and multi-layered GFRP was investigated on several levels using a structural approach. Components of the electrical conductivity tensor for unidirectional-reinforced monolayer were calculated similarly as in micromechanics using the conductivity of the nanomodified matrix. The electrical conductivity of multilayer composite was calculated using laminate theory and compared with values measured experimentally for various fiber orientation angles. Calculated and experimental data were in good agree…
Voltammetric determination of platinum in perfusate and blood: Preliminary data on pharmacokinetic study of arterial infusion with oxaliplatin
2012
Abstract Because Platinum Group Elements have found widespread use in catalytic converters in cars and as chemotherapeutic agent, interest in the development of reliable analytical methods is carried out in order to monitor these analita in humans to protect the citizen's health. Considering that information on the levels of many trace elements in biological matrices is scarce and for many non-essential elements, baseline levels in the population, and especially in those particularly exposed to the risk are lacking, in this paper we optimize an analytical method for biological matrices, using a voltammetric technique to measure the concentration of Pt in blood and perfusate. The amount of P…
Volumes of aqueous block copolymers based on poly(propylene oxides) and poly(ethylene oxides) in a large temperature range: A quantitative description
2006
The focus of this paper was on a quantitative comprehension of temperature effect on the volumes of aqueous di-block and triblock copolymers, based on propylene oxide (PO) and ethylene oxide (EO) units. To this purpose, literature data dealing with (EO316PO94 + water) and (EO13PO30EO13 + water) mixtures were analyzed. The volume vs. temperature trends were rationalized on the basis of the (unimers + aggregate) equilibrium by taking into account the temperature effect on both the partial molar volumes of the unimeric and the aggregated copolymer as well as the equilibrium constant of micellization. The analysis extended to the expansibility allowed to quantify the contribution for the shift …