Search results for "layer"
showing 10 items of 2667 documents
Radio-metabolite analysis of carbon-11 biochemical partitioning to non-structural carbohydrates for integrated metabolism and transport studies.
2013
Metabolism and phloem transport of carbohydrates are interactive processes, yet each is often studied in isolation from the other. Carbon-11 ((11)C) has been successfully used to study transport and allocation processes dynamically over time. There is a need for techniques to determine metabolic partitioning of newly fixed carbon that are compatible with existing non-invasive (11)C-based methodologies for the study of phloem transport. In this report, we present methods using (11)C-labeled CO2 to trace carbon partitioning to the major non-structural carbohydrates in leaves-sucrose, glucose, fructose and starch. High-performance thin-layer chromatography (HPTLC) was adapted to provide multis…
Comment la recherche académique peut éclairer l’arrivée des pure-players dans le monde physique?
2019
Numerical simulations of air pollutant dispersion in a stratified planetary boundary layer
1978
Abstract A numerical model is described for computing pollutant concentration distributions downwind from a source. It is based on the three-dimensional dispersion equation governing the time-dependent advective and diffusive transport of air pollutants and is solved numerically by a mixed Lagrangian-Eulerian finite-difference scheme. The model includes the vertical wind shear, the turning of the actual wind, and vertical variations of the vertical eddy diffusivity. In this paper the model is used to simulate the pollutant dispersion process in a stratified planetary boundary layer. The vertical profiles of horizontal mean wind and vertical eddy diffusivities are calculated numerically from…
Evaluation of organic compound source and natural attenuation, Liepaja Latvia
2004
Liepaja harbor is a former Soviet military site. Remediation of the harbor basin, including dredging of the sediments heavily contaminated with petroleum hydrocarbons and heavy metals is necessary to convert the harbor for civilian use. Abandoned pollution sources on land still continue to leach contaminants into the harbor basin. Our long-term research objective therefore is to identify transport pathways into the harbor sediments and to assess the in-situ degradation of pollutants in the system. The Liepaja harbor is treated as a complex system, where processes in the water column interact with the sediments and the nepheloid sediment boundary layer. For this research PAHs are used as the…
Potentially toxic elements in fen peatland soils located near lignite-fired power plants in Central Poland
2021
Abstract The Grojec Valley (GV) peatland area in Central Poland is located close to lignite-fired power plants, which could be sources of potentially toxic elements (PTE). The aims of this study are: (1) to determine the effect of the lignite-fired power plants on soil pollution, (2) to evaluate pollution indices and magnetic susceptibility methods for determining the origin and distribution of PTE in soils, and (3) to demonstrate the importance of appropriate geochemical background (GB) selection for pollution studies in peatland soils. In order to comprehensively assess the soil pollution, four pollution indices (calculated using various types of GBs), and the mass-specific magnetic susce…
Bioinspired catechol-terminated self-assembled monolayers with enhanced adhesion properties
2013
The role of the catechol moiety in the adhesive properties of mussel proteins and related synthetic materials has been extensively studied in the last years but still remains elusive. Here, a simplified model approach is presented based on a self-assembled monolayer (SAM) of upward-facing catechols thiol-bound to epitaxial gold substrates. The orientation of the catechol moieties is confirmed by spectroscopy, which also showed lack of significant amounts of interfering o-quinones. Local force-distance curves on the SAM measured by atomic force microscopy (AFM) shows an average adhesion force of 45 nN, stronger than that of a reference polydopamine coating, along with higher reproducibility …
Does a specific genetic background influence endurance or power-orientated phenotypes?
2012
The purpose of this study was to determine the probability of individuals having the “best” mitochondrial biogenesis related polygenic profile that could increase performance. We compared polygenic profile analyzing several polymorphisms on sixty professional italian soccer players, considered “power-oriented athletes” and thirty sedentary volunteers. Samples of venous blood were obtained by standard clinical procedures and anticoagulant-treated blood was used to prepare genomic DNA. The polymorphic sites were scanned using PCR-RFLP protocols with different enzyme. Furthermore, a cloted part of venus blood sample was used to obtain serum from which we analyzed total cholesterol, high densit…
1979
Spectroscopic studies of the stability of monolayers of 2-docosylamino-5-nitropyridine at the air/water interface
1991
Monolayers of 2-docosylamino-5-nitropyridine (DCANP) at the air/water interface were investigated by UV/Vis spectroscopy. The combination of this method with the classic constant-area relaxation technique yields insight into the longtime stability and the collapse behavior of monolayers. We have demonstrated that monolayers of DCANP are certainly stable under standard deposition conditions. At surface pressures above 20 mN/m monolayer instabilities lead to the formation of a three-dimensional head-to-head multilayered structure.
Tunable Phosphorescent Emission through Energy Transfer within Multilayer Thin Films Based on a Carbazole-Based Host and Ir(III)-Complex Guest System
2009
A new method to tune both phosphorescence emission intensity and spectroscopic colors based on the alternatively structured host/guest multilayer thin films prepared by the spin-assisted LbL deposition is presented. Their emission characteristics are demonstrated with pairs of positively charged Ir-PEI complexes as guests and negatively charged CBZ-PAA as hosts. The phosphorescent emission of Ir-PEI complexes is enhanced by the energy transfer from the host to the guest and, additionally, this energy transfer can be finely tuned by the insertion of spacer layers between the phosphorescent donor and acceptor layers to vary the emission intensity as well as to render different emission colors.