Search results for "matrix"
showing 10 items of 3205 documents
Materiality assessment in sustainability reporting : case study of the airline industry
2017
Materiality has been heavily emphasized in different sustainability reporting guidelines to increase the quality of the sustainability reports and report issues that are most aligned with the company’s most significant economic, environmental and social issues. In this thesis materiality analysis in sustainability reporting is analyzed. Firstly, in the theoretical part, the concept of sustainability reporting and materiality is explained along with the provision of materiality in different reporting guidelines. In this research section, fifteen different airlines’ sustainability reports are analyzed to find out how the materiality analysis is carried out in the airlines. The study is focuse…
"Me ollaan mukana tässä experimentissä" : lingvististiska resurser och språkpraktiker i tvåspråkiga ungdomssamtal i Haparanda, Stockholm och Helsingf…
2017
The thesis explores bilingual adolescents’ language use, linguistic resources, and language practices in interaction at three junior high schools in Haparanda, a Swedish town on the country’s northeastern border with Finland. A comparison is also made with interaction among bilingual adolescents at two Sweden-Finnish junior high schools in Stockholm and at one Swedish-speaking junior high school in Helsinki. The aim of the study is to increase our knowledge of bilingual adolescents’ interaction practices and language repertoires, i.e. translanguaging, in interaction. The primary data consists of close to eleven hours of video- and audio-recorded informal group and pair conversations. The da…
Assessment of nonnegative matrix factorization algorithms for electroencephalography spectral analysis.
2020
AbstractBackgroundNonnegative matrix factorization (NMF) has been successfully used for electroencephalography (EEG) spectral analysis. Since NMF was proposed in the 1990s, many adaptive algorithms have been developed. However, the performance of their use in EEG data analysis has not been fully compared. Here, we provide a comparison of four NMF algorithms in terms of accuracy of estimation, stability (repeatability of the results) and time complexity of algorithms with simulated data. In the practical application of NMF algorithms, stability plays an important role, which was an emphasis in the comparison. A Hierarchical clustering algorithm was implemented to evaluate the stability of NM…
Comparative ultrastructure and carbohydrate composition of gastroliths from Astacidae, Cambaridae and Parastacidae freshwater crayfish (Crustacea, De…
2012
21 pages; International audience; Crustaceans have to cyclically replace their rigid exoskeleton in order to grow. Most of them harden this skeleton by a calcification process. Some decapods (land crabs, lobsters and crayfish) elaborate calcium storage structures as a reservoir of calcium ions in their stomach wall, as so-called gastroliths. For a better understanding of the cyclic elaboration of these calcium deposits, we studied the ultrastructure of gastroliths from freshwater crayfish by using a combination of microscopic and physical techniques. Because sugars are also molecules putatively involved in the elaboration process of these biomineralizations, we also determined their carbohy…
Development of Composites with a Self-Healing Function
2015
This research aimed to realize experimentally the facilevascular self-healing system in epoxy glass fibre reinforced composite. Using flexiblepolytetrafluoroethylene tubes as removable preforms, the channels were embeddedinto both neat epoxy resin and unidirectional glass-fibre reinforced epoxy laminate.Room temperature curable epoxy resin with a surfactant and an amine-basedhardener were the components of the binary healing agent. The specimens oftapered double cantilever beam geometry were subjected to Mode I fracture tests.Fracture of specimens released the healing agent from channels and triggeredself-healing process of the crack. Tested neat epoxy resin specimensdemonstrated recovery o…
Tracking Healing Process of Experimental Liver Injuries Treated with Different Sealants and Adhesives Biomaterials. Matrix Metalloproteinase Evaluati…
2018
Sealants and adhesives are used in the repair and preservation of damaged solid organs. This study examines the matrix metalloproteinases (MMP) activity in the healing of liver injuries treated with two biological adhesives (Tachosil® and GelitaSpon®) as well as that of a new elastic cyanoacrylate (Adhflex®). Methods. We induced in 90 male rats hepatic lesions using a Stiefel biopsy punch in the liver. Wound healing was assessed 2, 6, and 18 days after injury by quantifying MMP1, 2, 8, 9, and 13 tissue levels. The histopathological repair was evaluated by hematoxylin-eosin, Masson’s trichrome, and Periodic Acid Schiff (PAS) staining and CD31, CD68 immunohis…
A multiresidue analytical method for trace level determination of antibiotics and antiretroviral drugs in wastewater and surface water using SPE-LC-M…
2016
An analytical method for simultaneous determination of seven commonly used antibiotics and three antiretrovirals in surface water and urban wastewater at the ng L−1 level has been developed. The method involves concentration and clean-up by solid phase extraction (SPE) followed by identification and quantification by liquid chromatography tandem mass spectrometry (LC-ESI-MS/MS). The use of matrix-matched calibration curves constructed by spiking surface water was evaluated for quantification and compared with the internal standard method using isotopically labelled compounds. The method gave absolute recoveries of 41–116% with most of the compounds having recoveries >50%. The LOQs ranged fr…
The boson peak of deeply cooled confined water reveals the existence of a low-temperature liquid-liquid crossover.
2014
International audience; The Boson peak of deeply cooled water confined in the pores of a silica xerogel is studied by inelastic neutron scattering at different hydration levels to separate the contributions from matrix, water on the pore surfaces and "internal" water. Our results reveal that at high hydration level, where the contribution from internal water is dominant, the temperature dependence of the Boson peak intensity shows an inflection point at about 225 K. The complementary use of differential scanning calorimetry to describe the thermodynamics of the system allows identifying the inflection point as the signature of a water liquid-liquid crossover.
Biochemical characteristics of the soluble organic matrix from the shell of three recent terebratulid brachiopod species.
2008
7 pages; International audience; To build their shells, brachiopods secrete a mixture of proteins and polysaccharides, collectively called the organic matrix. This matrix mediates the calcification process by allowing crystal nucleation followed by elongation and finally by stopping the crystal growth. Ultimately, the matrix controls the different microstructures formed. Brachiopod shells are composites with both organic and inorganic constituents intimately associated. This work represents an attempt to characterize the matrices using two combined approaches: (1) scanning electron microscopy for localization within the shell, (2) analysing extracted matrices at the molecular level to deter…
Artificial cartilage bio-matrix formed of hyaluronic acid and Mg2+-polyphosphate.
2016
Here we show that inorganic polyphosphate (polyP), a polyanionic metabolic regulator consisting of multiple phosphate residues linked by energy-rich phosphoanhydride bonds, is present in the synovial fluid. In a biomimetic approach, to enhance cartilage synthesis and regeneration, we prepared amorphous polyP microparticles with Mg2+ as counterions. The particles were characterised by X-ray diffraction (XRD), energy-dispersive X-ray (EDX) and Fourier transformed infrared spectroscopic (FTIR) analyses. Similar particles were obtained after addition of Mg2+ ions to a solution containing hyaluronic acid, as a major component of the synovial fluid, and soluble Na-polyP. The viscous paste-like ma…