Search results for " Matrix"
showing 10 items of 2053 documents
Effect of Gold(I) on the Room-Temperature Phosphorescence of Ethynylphenanthrene.
2020
The synthesis of two series of gold(I) complexes containing the general formulae PR 3 ‐Au‐C≡C‐phenanthrene (PR 3 = PPh 3 ( 1a / 2a ), PMe 3 ( 1b / 2b ), PNaph 3 ( 1c / 2c )) or (diphos)(Au‐C≡C‐phenanthrene) 2 (diphos = 1,1‐ bis (diphenylphosphino)methane, dppm ( 1d / 2d ); 1,4‐ bis (diphenylphosphino)butane, dppb ( 1e / 2e )) have been synthesized. The two series differ on the position of the alkynyl substituent on the phenanthrene chromophore, being at the 9‐position (9‐ethynylphenanthrene) for the L1 ‐series and at the 2‐position (2‐ethynylphenanthrene) for the L2 ‐series. The compounds have been fully characterized by 1 H and 31 P NMR and IR spectroscopy, mass spectrometry and single cry…
Conformational-Dependent Photodissociation of Glycolic Acid in an Argon Matrix
2023
Ultraviolet-induced photodissociation and photo-isomerization of the three most stable conformers (SSC, GAC, and AAT) of glycolic acid are investigated in a low-temperature solid argon matrix using FTIR spectroscopy and employing laser radiation with wavelengths of 212 nm, 226 nm, and 230 nm. The present work broadens the wavelength range of photochemical studies of glycolic acid, thus extending the understanding of the overall photochemistry of the compound. The proposed kinetic model for the photodissociation of glycolic acid proceeds from the lowest energy conformer (SSC). The model suggests that ultraviolet light induces isomerization only between the SSC and GAC conformers and between …
Assessment of occupational exposure to pesticides in Spain through a job-exposure matrix (MatEmESp, 1996-2005)
2014
Introducción: La exposición laboral a plaguicidas ha sido asociada a numerosos problemas de salud. Sin embargo, la información sobre la exposición de los trabajadores afectados en España es escasa y dispersa. Objetivos: El objetivo de este trabajo fue estimar el nivel y la prevalencia de la exposición laboral a plaguicidas en España para el periodo 1996-2005, como parte del proyecto de construcción de la matriz empleo-exposición española, MatEmESp. Métodos: El establecimiento de las ocupaciones expuestas, los agentes de referencia y las estimaciones de exposición se basó en información de otras matrices, datos de evaluaciones de riesgos en empresas españolas y revisión de la bibliografía. R…
Evaluación de la exposición laboral a plaguicidas en España mediante una matriz empleo-exposición (MatEmESp, 1996-2005)
2014
Originales [ES] Introducción: La exposición laboral a plaguicidas ha sido asociada a numerosos problemas de salud. Sin embargo, la información sobre la exposición de los trabajadores afectados en España es escasa y dispersa.Objetivos: El objetivo de este trabajo fue estimar el nivel y la prevalencia de la exposición laboral a plaguicidas en España para el periodo 1996-2005, como parte del proyecto de construcción de la matriz empleo-exposición española, MatEmESp.Métodos: El establecimiento de las ocupaciones expuestas, los agentes de referencia y las estimaciones de exposición se basó en información de otras matrices, datos de evaluaciones de riesgos en empresas españolas y revisión de la b…
Non-conventional synthesis and photophysical studies of platinum(ii) complexes with methylene bridged 2,2′-dipyridylamine derivatives
2019
Methylene bridged 2,2′-dipyridylamine (dpa) derivatives and their metal complexes possess outstanding properties due to their inherent structural flexibility. Synthesis of such complexes typically involves derivatization of dpa followed by coordination on metals, and may not always be very efficient. In this work, an alternative synthetic approach, involving the derivatization step after – rather than prior to – coordination of dpa on metal center, is proposed and applied to synthesis of a number of platinum(II) complexes with substituted benzyldi(2-pyridyl)amines. Comparison with the more conventional synthetic route reveals greater efficiency and versatility of the proposed approach. The …
Asymptotic and numerical studies of electron scattering in 2D quantum waveguides of variable cross-section
2012
Analysis of FBG reflection spectra under uniform and non-uniform transverse loads
2019
Loads applied transversely on the external surface of waveguides change their circular cross-sectional geometry generating birefringence. Due to this effect the reflected spectrum of a Fibre Bragg grating (FBG) undergoes a splitting of the single peak of the Bragg wavelength. In this work, we employed the Transfer Matrix Method (TMM) for x- and y-polarized wave-modes to model the uniform FBG reflection spectra for uniform and non-uniform transverse loads. We also performed experimental measurements for two different transverse load scenarios. The load profiles chosen for these experiments were applied on the FBG sensor through a block of steel and a roll bearing pin. Then, the modelled and …
Polymorphic chiral squaraine crystallites in textured thin films
2020
Chirality 32(5), 619 - 631 (2020). doi:10.1002/chir.23213
Physical and chemical interactions involved in several flavour compounds/food matrix systems
2002
National audience; Food-matrix components, such as proteins, polysaccharides, and lipids interact with flavour compounds in different ways. Proteins bind flavour compounds mostly by hydrophobic interactions and possible hydrogen bonding, as illustrated by molecular visualisation. Addition of fat induces a great retention of hydrophobic compounds, which depend on the nature of fat, degree of unsaturation, hydrophobic chain length of fatty acids. Addition of hydrocolloids modifies the release of hydrophobic aroma compounds, due to a lower diffusion in the matrix. In jellified systems, gel structure not only affects partition coefficients but also mass transfer coefficients of flavour compound…
BUILDING THE PROJECT TEAM AND PROJECT ORGANIZATION – CHALLENGES AND OBSTACLES
2011
The building of a project team can be one of the first hurdles the future team manager faces. The blame for this can be constraints in terms of resources to fund salaries, lack of adequate or properly trained personnel, unavailability of specialists the manager needs within the project in the period this is scheduled, but also other causes. The building of a project team process must also correlated with its future structure, the two components influencing each other in both directions. Choosing an appropriate structure for the project to be implemented is not only necessary, but, moreover, may prove fatal to the extent that is not obtained.