Amelia Carolina Sparavigna

This atlas is proposing the fingerprints of the SERS (Surface-Enhanced Raman Spectroscopy) spectra of metabolites, published by Sherman et al. in Talanta, 2020, in an article entitled “A surface-enhanced Raman spectroscopy database of 63 metabolites”. The atlas of fingerprints is based on q-Gaussian deconvolutions and Fityk software.

The discovery of the Diary of Merer (papyri Wadi al-Jarf) allows us to see the Egyptian calendar applied in a logbook. The diary is dated to the 26th year of reign of Khufu and describes Merer and his crew transporting the limestone blocks from the Tura quarries to Akhet Khufu, that is, the pyramid of Khufu (Old Kingdom). We find a calendar with 30-day months, 10-day weeks, five epagomenal days (Tallet, 2017) and Merer's job adapted to the seasons of the year. Seasons and epagomenal days have names according to inscriptions on the east wall of the Tehne tomb of Nj-k'-'nh (Nikaiankh), end of Fourth Dynasty or early Fifth Dynasty. The Diary gives us an overall impression of extreme modernity in the logistics of ancient Egypt. And Merer looks like a person with a reputation for good timekeeping at Akhet Khufu.

Here we consider the minerals in the barite group and their attenuated total reflectance (ATR) infrared spectra, that we can find in the RRUFF database. We apply the q-BWF functions to deconvolute the components of the spectra. The q-BWF functions are the asymmetric line shapes that Sparavigna defined in 2023, to generalize the BWF (Breit-Wigner-Fano) functions. Good results are obtained for the deconvolution of barite, celestine and anhydrite ATR-IR spectra.

Here we consider calcite and its spectra (Raman and infrared) that we can find in the RRUFF database. We apply q-Gaussian and q-BWF functions to decompose the spectra. The q-Gaussian functions had been derived in the framework of Tsallis analysis of entropy. Their use for Raman spectroscopy has been proposed by Sparavigna, 2023. The q-BWF functions have been defined by Sparavigna, 2023, to generalize the BWF (Breit-Wigner-Fano) functions, and proposed for fitting to asymmetric peaks in Raman spectroscopy. Besides examples of decompositions of RRUFF spectra, a review of literature about calcite is given. We will also add an appendix about the Raman spectra of calcite recorded by R. S. Krishnan (1945), by means of the F. Rasetti technique (1932) which was using the λ2536.5 mercury resonance radiation. As we can see, Krishnan succeeded to record the second order components of the spectrum.

Natrolite, Na2(Si3Al2)O10·2H2O, is a member of a group of zeolite minerals, made of hydrated aluminosilicate minerals. Due to their structure, zeolites have channels, through which water and ions can move. In the RRUFF database, we find the following members of the group: natrolite, mesolite, scolecite, and gonnardite. In the database, Raman spectra are provided where we can easily observe the OH-stretching region of water. We propose the deconvolutions in q-Gaussian functions of these spectra, comparing the obtained results with those available from literature. A review of literature about natrolite is also proposed.

Vivianite is a hydrated iron phosphate mineral (Fe3(PO4)2·8H2O), crystallized in a monoclinic system. It is the endmember of a mineral series known as the vivianite group, where minerals have the general formula A3(XO4)2·8H2O, A is a divalent metal cation and X is phosphorus P or arsenic As. Today, vivianite is attracting interest as a promising material for recovering phosphorous from wastewaters. In fact, the presence in wastewater sludges of soluble iron and phosphorus can lead to vivianite formation. As a crystal, it is a naturally occurring Van der Walls material. It can be easily characterized by means of Raman and infrared spectroscopies. Here we will consider the Raman spectroscopy, precisely that related to the hydroxyl-stretching region. We will propose the deconvolutions in q-Gaussian functions of spectra from RRUFF database, comparing the obtained results with those available from literature. Besides vivianite, we will consider also baricite and bobierrite for comparison (baricite and bobierrite are two other members of the vivianite group). About the hydroxyl-stretching region and the use of q-Gaussians, we take the chance to continue a discussion regarding the Raman spectroscopy of water, discussion that we started in March 2024.

Here we study the Raman spectra of Barium Titanate, BaTiO3, given in the RRUFF and ROD databases. Being the Raman bands strongly asymmetric, we are deconvoluting them by means of the q-BWF functions. These functions are generalizing the Breit-Wigner-Fano line shape in the framework of the q-exponential function of Tsallis statistics. Besides the deconvolution of Raman spectra, we consider the literature on BaTiO3 Raman spectroscopy, particularly the assignment of the bands. Being the wavenumbers of some A1 and E modes very close, the observed modes are mixed. Moreover, dips in the spectra have suggested as due to the presence of anharmonicity, interference and Fano resonance.

Italian L'articolo propone una discussione del Dies Natalis, il giorno di fondazione, delle città romane. Ci si basa principalmente sul lavoro di A. M. Eckstein, che illustra, con dovizia di particolari, le varie proposte in merito. Non vi è infatti alcuna fonte antica che ci dica come i Romani stabilissero il Dies Natalis delle città. Si illustrerà anche l'orientamento astronomico proposto da Heinrich Nissen nel suo Das Templum, 1869. Nissen propone il Dies Natalis come il giorno all'alba del quale il decumano della città viene stabilito in direzione del sorgere del sole. Verificare l'orientamento astronomico è facile, dato che basta considerare i decumani delle città di cui è noto il Dies Natalis. Alcuni casi specifici, Piacenza, Bologna, Brindisi, e Treviri mostrano come il Dies Natalis non ha nulla a che fare con la direzione del decumano. Verranno fatti cenni a studi su Nicopolis, Ostia e Miseno. Si discuteranno anche Aosta e Jesi. English The article proposes a discussion of the Dies Natalis, the day of foundation of the Roman towns. We rely mainly on the work by A. M. Eckstein, who illustrates, in detail, the various proposals in this regard. In fact, there is no ancient source that tells us how the Romans established the Dies Natalis of the towns. The astronomical orientation proposed by Heinrich Nissen in his Das Templum, 1869 will also be illustrated. Nissen proposes the Dies Natalis as the day at dawn on which the decumanus of the town is established in the direction of sunrise. Verifying the astronomical orientation is easy, given that all we must do is consider the decumani of the towns whose Dies Natalis is known. Some specific cases, Piacenza, Bologna, Brindisi, and Trier show how the Dies Natalis has nothing to do with the direction of the decumanus. References will be made to studies on Nicopolis, Ostia and Miseno. Aosta and Jesi will be discussed too.

RRUFF database is proposing the Raman broad scans of glasses CaO-Al2O3-SiO2 with rare earth element (REE) oxides, that is of CaO-RE2O3-Al2O3-SiO2 glasses. Raman data are courtesy of E. Cairns, University of Edinburgh. Here we show how we can use the q-BWF functions to decompose these spectra. The q-BWF functions are generalizing the Breit-Wigner-Fano line shape in the framework of the q-exponential function proposed by Constantino Tsallis and his statistics. Besides asymmetry, the decompositions with q-BWF line shapes are stressing Gaussian and non-Gaussian behaviors of components. The data analysis of CaO-RE2O3-Al2O3-SiO2 glasses is highlighting the presence of photoluminescence regular patterns in the Raman broad scans.

Recently, we have considered the Raman spectra of graphene and graphene oxide to understand the number of lines and the line shapes to be used for decomposing the spectra. Here we review some literature about the Raman spectroscopy of carbon nanotubes, focusing especially on the line shapes. As shown by literature, the Raman spectra are able of giving information on the nature of nanotubes (metallic or semiconducting) and if they are single- or multi-walled structures. We will find that the Raman spectroscopy is able of investigating even a single nanotube. It will be stressed the role of curvature in breaking the symmetry of carbon layers, to produce the observed Raman bands. In particular, the existence of a Breit-Wigner-Fano line will be investigated. We have encountered the BWF line in a previous review about molybdenum disulfide MoS2 Raman spectroscopy.