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D
Rahangdale, H. V., M. Guerra, P. K. Das, S. De, J. P. Santos, D. Mitra, and S. Saha. "Determination of subshell-resolved <span class="aps-inline-formula"><math><mi>L</mi></math></span>-shell-ionization cross sections of gold induced by 15–40-keV electrons." Physical Review A 89 (2014): 052708. AbstractWebsite
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Rahangdale, H. V., M. Guerra, P. K. Das, S. De, J. P. Santos, D. Mitra, and S. Saha. "Determination of subshell-resolved <span class="aps-inline-formula"><math><mi>L</mi></math></span>-shell-ionization cross sections of gold induced by 15–40-keV electrons." Physical Review A 89 (2014): 052708. AbstractWebsite
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Cardoso, Pedro, Pedro Amaro, Jose Paulo Santos, Joaquim T. de Assis, and Maria Luisa Carvalho. "Determination of Nickel and Manganese Contaminants in Pharmaceutical Iron Supplements using Energy Dispersive X-ray Fluorescence." Applied Spectroscopy (2016). AbstractWebsite

In this study, we investigate the capability of energy dispersive X-ray fluorescence (EDXF) spectrometry in a triaxial geometry apparatus as a fast and nondestructive determination method of both dominant and contaminant elements in pharmaceutical iron supplements. The following iron supplements brands with their respective active ingredients were analyzed: Neutrofer fólico (iron gylcinate), Anemifer (iron(II) sulfate monohydrate), Noripurum (iron(III)-hydroxide polymaltose complex), Sulferbel (iron(II) sulfate monohydrate), and Combiron Fólico (carbonyl iron). Although we observe a good agreement between the iron content obtained by the present method and that indicated in the supplement's prescribed dose, we observe contamination by manganese and nickel of up to 180 μg and 36 μg, respectively. These contents correspond to 7.2% and 14.4% of the permitted daily exposure of manganese and nickel, respectively, for an average adult individual as determined by the European Medicine Agency (EMEA). The method was successfully validated against the concentrations of several certified reference materials of biological light matrices with similar concentrations of contaminants. Moreover, we also validated our method by comparing the concentrations with those obtained with the inductively coupled plasma-atomic emission technique.

Cardoso, Pedro, Pedro Amaro, Jose Paulo Santos, Joaquim T. de Assis, and Maria Luisa Carvalho. "Determination of Nickel and Manganese Contaminants in Pharmaceutical Iron Supplements Using Energy Dispersive X-ray Fluorescence." Applied Spectroscopy 71 (2017): 432-437. AbstractWebsite
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Pessanha, Sofia, Ana Samouco, Ricardo Adão, Maria Luisa Carvalho, Jose Paulo Santos, and Pedro Amaro. "Detection limits evaluation of a portable energy dispersive X-ray fluorescence setup using different filter combinations." X-Ray Spectrometry 46 (2017): 102-106. AbstractWebsite

In this paper, we study the performance of a portable energy dispersive X‐ray fluorescence spectrometer by making use of different filter configurations at the X‐ray tube output. To fulfill this purpose,...

Marques, J., F. Parente, A. Costa, M. Martins, P. Indelicato, and J. P. Santos. "Decay of the 1s^{2}2s3p ^{3}P_{0} level in Be-like ions." Phys. Rev. A 86 (2012): 052521. AbstractWebsite

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C
Wain, Alison, Diogo Castro, {Maria Fernanda} Rollo, Frederico Nogueira, Gon{\c c}alo Santos, {Maria Gra{\c da c}a} Filipe, Isabel Tissot, {Jorge Miguel} Sampaio, {José Paulo} Santos, Manuel Lemos, Marta Manso, Matthias Tissot, Mauro Guerra, Miles Oglethorpe, Pedro Amaro, Pedro Pedroso, Rui Silva, Sofia Pessanha, and {Tiago A. N. } Silva. Cultura Material, Cultura Científica: Património Industrial para o Futuro. Portugal: Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2021. Abstract

Material, Culture, Scientific Culture: Industrial Heritage for the Future

Santos, J. P., F. Parente, and Y. K. Kim. "Cross sections for K-shell ionization of atoms by electron impact." Journal of Physics B: Atomic and Molecular Physics 36 (2003): 4211-4224. AbstractWebsite

The relativistic version of the binary-encounter Bethe (BEB) model is used to calculate cross sections for K-shell ionization of atoms by electron impact. The BEB model requires only two atomic constants, the binding energy and kinetic energy of the K electrons. These constants are listed for carbon to antimony. Comparisons with available experimental data on N, O, Na, Al, Cl, Ca, Cu, Se and Sb show good agreement. The K-shell ionization cross sections for C, Mg, P, S, Cr, As and Cd are tabulated.

Dyke, J. M., G. Levita, A. Morris, J. S. Ogden, A. A. Dias, M. Algarra, J. P. Santos, M. L. Costa, P. Rodrigues, M. M. Andrade, and M. T. Barros. "Contrasting Behavior in Azide Pyrolyses: An Investigation of the Thermal Decompositions of Methyl Azidoformate, Ethyl Azidoformate and 2-Azido-N, N-dimethylacetamide by Ultraviolet Photoelectron Spectroscopy and Matrix Isolation Infrared Spectroscopy." Chemistry - A European Journal 11 (2005): 1665-1676. Abstract
The thermal decompositions of methyl azidoformate (N3COOMe), ethyl azidoformate (N3COOEt) and 2-azido-N,N-dimethylacetamide (N3CH2CONMe2) have been studied by matrix isolation infrared spectroscopy and real-time ultraviolet photoelectron spectroscopy. N2 appears as an initial pyrolysis product in all systems, and the principal interest lies in the fate of the accompanying organic fragment. For methyl azidoformate, four accompanying products were observed: HNCO, H2CO, CH2NH and CO2, and these are believed to arise as a result of two competing decomposition routes of a four-membered cyclic intermediate. Ethyl azidoformate pyrolysis yields four corresponding products: HNCO, MeCHO, MeCHNH and CO2, together with the five-membered-ring compound 2-oxazolidone. In contrast, the initial pyrolysis of 2-azido-N,N-dimethyl acetamide, yields the novel imine intermediate Me2NCOCHNH, which subsequently decomposes into dimethyl formamide (HCONMe2), CO, Me2NH and HCN. This intermediate was detected by matrix isolation IR spectroscopy, and its identity confirmed both by a molecular orbital calculation of its IR spectrum, and by the temperature dependence and distribution of products in the PES and IR studies. Mechanisms are proposed for the formation and decomposition of all the products observed in these three systems, based on the experimental evidence and the results of supporting molecular orbital calculations.
Dyke, J. M., G. Levita, A. Morris, J. S. Ogden, A. A. Dias, M. Algarra, J. P. Santos, M. L. Costa, P. Rodrigues, M. M. Andrade, and M. T. Barros. "Contrasting Behavior in Azide Pyrolyses: An Investigation of the Thermal Decompositions of Methyl Azidoformate, Ethyl Azidoformate and 2-Azido-N, N-dimethylacetamide by Ultraviolet Photoelectron Spectroscopy and Matrix Isolation Infrared Spectroscopy." Chemistry - A European Journal 11 (2005): 1665-1676. Abstract

The thermal decompositions of methyl azidoformate (N3COOMe), ethyl azidoformate (N3COOEt) and 2-azido-N,N-dimethylacetamide (N3CH2CONMe2) have been studied by matrix isolation infrared spectroscopy and real-time ultraviolet photoelectron spectroscopy. N2 appears as an initial pyrolysis product in all systems, and the principal interest lies in the fate of the accompanying organic fragment. For methyl azidoformate, four accompanying products were observed: HNCO, H2CO, CH2NH and CO2, and these are believed to arise as a result of two competing decomposition routes of a four-membered cyclic intermediate. Ethyl azidoformate pyrolysis yields four corresponding products: HNCO, MeCHO, MeCHNH and CO2, together with the five-membered-ring compound 2-oxazolidone. In contrast, the initial pyrolysis of 2-azido-N,N-dimethyl acetamide, yields the novel imine intermediate Me2NCOCHNH, which subsequently decomposes into dimethyl formamide (HCONMe2), CO, Me2NH and HCN. This intermediate was detected by matrix isolation IR spectroscopy, and its identity confirmed both by a molecular orbital calculation of its IR spectrum, and by the temperature dependence and distribution of products in the PES and IR studies. Mechanisms are proposed for the formation and decomposition of all the products observed in these three systems, based on the experimental evidence and the results of supporting molecular orbital calculations.

Pinto, R. M., A. A. Dias, M. L. Costa, and J. P. Santos. "Computational study on the ionization energies of benzyl azide and its methyl derivatives." Journal of Molecular Structure: THEOCHEM 948 (2010): 15-20. AbstractWebsite
Ionization energies of benzyl azide (BA), C6H5CH2N3, its methyl derivatives, 2-, 3- and 4-methyl benzyl azide and (1-azidoethyl)benzene (2-, 3- and 4-MBA and 1-AEB), (CH3)C6H4CH2 N3, have been calculated with several basis sets, with M¯ller-Plesset and Hartree-Fock methods. The data are compared to the ionizations energies obtained from HeI photoelectron spectroscopy (UVPES) experiments, in order to support the correct assignment of the bands. The nature and character of the molecular orbitals are also discussed.
Pinto, R. M., A. A. Dias, M. L. Costa, and J. P. Santos. "Computational study on the ionization energies of benzyl azide and its methyl derivatives." Journal of Molecular Structure: THEOCHEM 948 (2010): 15-20. AbstractWebsite

Ionization energies of benzyl azide (BA), C6H5CH2N3, its methyl derivatives, 2-, 3- and 4-methyl benzyl azide and (1-azidoethyl)benzene (2-, 3- and 4-MBA and 1-AEB), (CH3)C6H4CH2 N3, have been calculated with several basis sets, with M¯ller-Plesset and Hartree-Fock methods. The data are compared to the ionizations energies obtained from HeI photoelectron spectroscopy (UVPES) experiments, in order to support the correct assignment of the bands. The nature and character of the molecular orbitals are also discussed.

Grilo, Filipe, Chintan Shah, Steffen Kühn, René Steinbrügge, Keisuke Fujii, José Marques, Ming Feng Gu, José Paulo Santos, José Crespo R. López-Urrutia, and Pedro Amaro. "Comprehensive Laboratory Measurements Resolving the {LMM} Dielectronic Recombination Satellite Lines in Ne-like Fe xvii Ions." The Astrophysical Journal 913 (2021): 140. AbstractWebsite
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Pessanha, S., C. Fonseca, J. P. Santos, M. L. Carvalho, and A. A. Dias. "Comparison of standard-based and standardless methods of quantification used in X-ray fluorescence analysis: Application to the exoskeleton of clams." X-Ray Spectrom. 47 (2018): 108-115. Abstract

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Sampaio, J. M., M. Guerra, F. Parente, T. I. Madeira, P. Indelicato, J. P. Santos, and J. P. Marques. "Calculations of photo-induced X-ray production cross-sections in the energy range 1–150 keV and average fluorescence yields for Zn, Cd and Hg." Atomic Data and Nuclear Data Tables 111-112 (2016): 67-86. AbstractWebsite

Atomic Data and Nuclear Data Tables, 111-112 (2016) 67-86. doi:10.1016/j.adt.2016.02.001

Amaro, P., A. Surzhykov, F. Parente, P. Indelicato, and J. P. Santos. "Calculation of two-photon decay rates of hydrogen-like ions by using B-polynomials." Journal of Physics A: Mathematical and Theoretical 44 (2011): 245302. AbstractWebsite
A new approach is laid out to investigate two-photon atomic transitions. It is based on the application of the finite-basis solutions constructed from the Bernstein polynomial (B-polynomial) sets. We show that such an approach provides a very promising route for the relativistic second-order (and even higher-order) calculations since it allows for analytical evaluation of the involved matrices elements. In order to illustrate possible applications of the method and to verify its accuracy, detailed calculations are performed for the 2 s 1/2 ‚Üí 1 s 1/2 transition in neutral hydrogen and hydrogen-like ions, which are compared with the theoretical predictions based on the well-established B-spline basis-set approach.
Amaro, P., A. Surzhykov, F. Parente, P. Indelicato, and J. P. Santos. "Calculation of two-photon decay rates of hydrogen-like ions by using B-polynomials." Journal of Physics A: Mathematical and Theoretical 44 (2011): 245302. AbstractWebsite

A new approach is laid out to investigate two-photon atomic transitions. It is based on the application of the finite-basis solutions constructed from the Bernstein polynomial (B-polynomial) sets. We show that such an approach provides a very promising route for the relativistic second-order (and even higher-order) calculations since it allows for analytical evaluation of the involved matrices elements. In order to illustrate possible applications of the method and to verify its accuracy, detailed calculations are performed for the 2 s 1/2 ‚Üí 1 s 1/2 transition in neutral hydrogen and hydrogen-like ions, which are compared with the theoretical predictions based on the well-established B-spline basis-set approach.

Santos, J. P., M. F. Laranjeira, and F. Parente. "Calculation of the triple to double ionization cross-section ratio of Li in the suddem approximation." Europhysics Letters 55 (2001): 479. Abstract

The triple-to-double ionization cross-section ratio of Li in the high-energy limit was computed in the sudden approximation with relativistic wave functions. Together with the calculated value of Dalgarno and Sadeghpour (Phys. Rev. A, 46 (1992) R3591), for the Li double-to-single ionization cross-section ratio, the value of 6.263x10-5 was obtained for the triple-to-single ionization cross-section ratio. This value is in full agreement with Wehlitz et al. experimental value of (6.38+-2.40)x10-5 obtained recently with synchrotron radiation (Phys. Rev. Lett., 81 (1998) 1813).

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Santos, I., M. S. Diniz, M. L. Carvalho, and J. P. Santos. "Assessment of Essential Elements and Heavy Metals Content on Mytilus galloprovincialis from River Tagus Estuary." Biological Trace Element Research (2014). AbstractWebsite

Trace elemental content was analysed in edible tissues of Mytilus galloprovincialis collected in five different sampling areas near the mouth of river Tagus estuary in Lisbon. The concentrations of essential elements (S, K, Ca, Fe, Cu, Zn, As, Br and Sr) were determined by energy-dispersive X-ray fluorescence (EDXRF) spectrometry, while toxic elements (Cr, Cd, Hg, Se and Pb) were measured by inductively coupled plasma-atomic emission spectrometry (ICP-AES). The results show that the essential elements K and S are present at the highest concentrations in all the studied samples reaching 2,920 and 4,520 μg g(-1) (fresh weight), respectively. The highest levels of heavy metals found were in two areas close to the city for Pb and Cd, but below the maximum allowed values.

Santos, I., M. S. Diniz, M. L. Carvalho, and J. P. Santos. "Assessment of Essential Elements and Heavy Metals Content on Mytilus galloprovincialis from River Tagus Estuary." Biological Trace Element Research (2014). AbstractWebsite

Trace elemental content was analysed in edible tissues of Mytilus galloprovincialis collected in five different sampling areas near the mouth of river Tagus estuary in Lisbon. The concentrations of essential elements (S, K, Ca, Fe, Cu, Zn, As, Br and Sr) were determined by energy-dispersive X-ray fluorescence (EDXRF) spectrometry, while toxic elements (Cr, Cd, Hg, Se and Pb) were measured by inductively coupled plasma-atomic emission spectrometry (ICP-AES). The results show that the essential elements K and S are present at the highest concentrations in all the studied samples reaching 2,920 and 4,520 μg g(-1) (fresh weight), respectively. The highest levels of heavy metals found were in two areas close to the city for Pb and Cd, but below the maximum allowed values.

Sampaio, J. M., T. I. Madeira, J. P. Marques, F. Parente, A. M. Costa, P. Indelicato, J. P. Santos, M. - C. Lépy, and Y. Ménesguen. "Approaches for theoretical and experimental determinations of K-shell decay rates and fluorescence yields in Ge." Physical Review A 89 (2014): 012512. AbstractWebsite
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Sampaio, J. M., T. I. Madeira, J. P. Marques, F. Parente, A. M. Costa, P. Indelicato, J. P. Santos, M. - C. Lépy, and Y. Ménesguen. "Approaches for theoretical and experimental determinations of K-shell decay rates and fluorescence yields in Ge." Physical Review A 89 (2014): 012512. AbstractWebsite
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Katriel, Jacob, J. P. Marques, P. Indelicato, A. M. Costa, M. C. Martins, J. P. Santos, and F. Parente. "Approach towards the critical charge of some excited states of the Be isoelectronic series." Physical Review A 90 (2014): 052519-5. AbstractWebsite
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Santos, J. P., Iulian Otel, Joao Silveira, Valentina Vassilenko, António Mata, Maria Luísa Carvalho, José Paulo Santos, and Sofia Pessanha. "Application of Unsupervised Multivariate Analysis Methods to Raman Spectroscopic Assessment of Human Dental Enamel." Computers (2021). AbstractWebsite
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Santos, J. P., F. Parente, and P. Indelicato. "Application of B-splines finite basis sets to relativistic two-photon decay rates of 2s level in hydrogenic ions." The European Physical Journal D 3 (1998): 43-52. AbstractWebsite

A theoretical study of the one- and two-photon spontaneous emission rates from the 2 s1/2 state of one-electron ions is presented. High-precision values of the relativistic emission rates for ions with nuclear charge Z up to 100 are obtained through the use of finite basis sets for the Dirac equation constructed from B-splines. Furthermore, we analyze the influence of the inclusion of quantum electrodynamics corrections in the initial and final state energies.