Very Intense Distinct Blue and Red Photoluminescence Emission in MgTiO3 Thin Films Prepared by the Polymeric Precursor Method: An Experimental and Theoretical Approach

MgTiO3 (MTO) thin films were prepared by the polymeric precursor method with posterior spin-coating deposition. The films were deposited on Pt(111)/Ti/SiO2/Si(100) substrates and heat treated at 350 degrees C for 2 h and then heat treated at 400, 450, 500, 550, 600, 650 and 700 C for 2 h. The degree of structural order disorder, optical properties, and morphology of the MTO thin films were investigated by X-ray diffraction (XRD), micro-Raman spectroscopy (MR), ultraviolet-visible (UV-vis) absorption spectroscopy, photoluminescence (PL) measurements, and field-emission gun scanning electron microscopy (FEG-SEM) to investigate the morphology. XRD revealed that an increase in the annealing temperature resulted in a structural organization of MTO thin films. First-principles quantum mechanical calculations based on density functional theory (B3LYP level) were employed to study the electronic structure of ordered and disordered asymmetric models. The electronic properties were analyzed, and the relevance of the present theoretical and experimental results was discussed in the light of PL behavior. The presence of localized electronic levels and a charge gradient in the band gap due to a break in the symmetry are responsible for the PL in disordered MTO lattice.

Characterization of polysaccharides from Hypnea spinella (Gigartinales) and Halopithys incurva (Ceramiales) and their effect on RAW 264.7 macrophage activity

[EN] Red algae have been reported to be an important source of polysaccharides with potential immunomodulatory properties. The objective of this study was to characterize the polysaccharides from Halopithys incurva and Hypnea spinella and to evaluate their effect on the synthesis of cytokines by murine cell line RAW 264.7 macrophages. Polysaccharides were obtained by N-cetylpyridiniumbromide precipitation and characterized by Fourier transform-infrared spectroscopy. Their effect on the activity of RAW 264.7 macrophages was examined by quantification of tumor necrosis factor (TNF)-α, interleukin (IL)-6, and nitric oxide (NO) production using enzyme-linked immunosorbent assays. The activation of the cytokine IL-6 and NO increased linearly as the concentration of polysaccharides from H. incurva and Hy. spinella increased. In general, the activation of IL-6 and NO was tenfold greater when macrophages were exposed to polysaccharides from H. incurva than when exposed to polysaccharides from Hy. spinella. In contrast, TNF-α concentration did not increase when macrophages were exposed to increasing polysaccharide levels. These results indicate that polysaccharides are strong cytokine IL-6 inducers.

Non-Covalent Interaction: Revealed by Rotational Spectroscopy

The pulsed jet Fourier transform microwave spectroscopy have been applied to several molecular complexes involving H2O, freons, methane, carboxylic acids, and rare gas. The obtained results showcase the suitability of this technique for studying the intermolecular interactions. The rotational spectra of three water adducts of halogenated organic molecules, i.e. chlorotrifluoroethylene, isoflurane and alfa,alfa,alfa,-trifluoroanisole, have been investigated. It has been found that, the halogenation of the partner molecules definitely changes the way in which water will link to the partner molecule. Quadrupole hyperfine structures and/or the tunneling splittings have been observed in the rotational spectra of difluoromethane-dichloromethane, chlorotrifluorometane-fluoromethane, difluoromethane-formaldehyde and trifluoromethane-benzene. These features have been useful to describe their intermolecular interactions (weak hydrogen bonds or halogen bonds), and to size the potential energy surfaces of their internal motions. The rotational spectrum of pyridine-methane pointed out that methane prefers to locate above the ring and link to pyridine through a C-H•••π weak hydrogen bond, rather than the C-H•••n interaction. This behavior, typical of complexes of pyridine with rare gases, suggests classifying CH4, in relation to its ability to form molecular complexes with aromatic molecules, as a pseudo rare gas. The conformational equilibria of three bi-molecules of carboxylic acids, acrylic acid-trifluoroacetic acid, difluoroacetic acid-formic acid and acrylic acid-fluoroacetic acid have been studied. The increase of the hydrogen bond length upon H→D isotopic substitution (Ubbelohde effect) has been deduced from the elongation of the carboxylic carbons C•••C distance. The van der Waals complex tetrahydrofuran-krypton shows that the systematic doubling of the rotational lines has been attributed to the residual pseudo-rotation of tetrahydrofuran in the complex, based on the values of the Coriolis coupling constants, and on the type (mu_b) of the interstate transitions.

Study of molecules of astrochemical, astrophysical and atmospheric interest by means of High - Resolution Infrared Spectroscopy

The spectroscopic investigation of the gas-phase molecules relevant for the chemistry of the atmosphere and of the interstellar medium has been performed. Two types of molecules have been studied, linear and symmetric top. Several experimental high-resolution techniques have been adopted, exploiting the spectrometers available in Bologna, Venezia, Brussels and Wuppertal: Fourier-Transform-Infrared Spectroscopy, Cavity-Ring-Down Spectroscopy, Cavity-Enhanced-Absorption Spectroscopy, Tunable-Diode-Laser Spectroscopy. Concerning linear molecules, the spectra of a number of isotopologues of acetylene, 12C2D2, H12C13CD, H13C12CD, 13C12CD2, of DCCF and monodeuterodiacetylene DC4H, have been studied, from 320 to 6800 cm-1. This interval covers bending, stretching, overtone and combination bands, the focus on specific ranges depending on the molecule. In particular, the analysis of the bending modes has been performed for 12C2D2 (450-2200 cm-1), 13C12CD2 (450-1700 cm-1), DCCF (320-850cm-1) and DC4H (450-1100 cm-1), of the stretching-bending system for 12C2D2 (450-5500 cm-1) and of the 2nu1 and combination bands up to four quanta of excitation for H12C13CD, H13C12CD and 13C12CD2 (6130-6800 cm-1). In case of symmetric top molecules, CH3CCH has been investigated in the 2nu1 region (6200-6700 cm-1), which is particularly congested due to the huge network of states affected by Coriolis and anharmonic interactions. The bending fundamentals of 15ND3 (450-2700 cm-1) have been studied for the first time, characterizing completely the bending states, v2 = 1 and v4 = 1, whereas the analysis of the stretching modes, which evidenced the presence of several perturbations, has been started. Finally, the fundamental band nu4 of CF3Br in the 1190-1220 cm-1 region has been investigated. Transitions belonging to the CF379Br and CF381Br molecules have been identified since the spectra were recorded using a sample containing the two isotopologues in natural abundance. This allowed the characterization of the v4 = 1 state for both isotopologues and the evaluation of the bromine isotopic splitting.

Contribution of Non-Covalent Interactions and Electronic Effects on the Conformational Landscape and Tautomeric Equilibria of Molecules and Molecular Complexes: Structural and Dynamical Data from Rotational Spectroscopy

This thesis concerns the study of complex conformational surfaces and tautomeric equilibria of molecules and molecular complexes by quantum chemical methods and rotational spectroscopy techniques. In particular, the focus of this research is on the effects of substitution and noncovalent interactions in determining the energies and geometries of different conformers, tautomers or molecular complexes. The Free-Jet Absorption Millimeter Wave spectroscopy and the Pulsed-Jet Fourier Transform Microwave spectroscopy have been applied to perform these studies and the obtained results showcase the suitability of these techniques for the study of conformational surfaces and intermolecular interactions. The series of investigations of selected medium-size molecules and complexes have shown how different instrumental setups can be used to obtain a variety of results on molecular properties. The systems studied, include molecules of biological interest such as anethole and molecules of astrophysical interest such as N-methylaminoethanol. Moreover halogenation effects have been investigated on halogen substituted tautomeric systems (5-chlorohydroxypyridine and 6-chlorohydroxypyridine), where it has shown that the position of the inserted halogen atom affects the prototropic equilibrium. As for fluorination effects, interesting results have been achieved investigating some small complexes where a molecule of water is used as a probe to reveal the changes on the electrostatic potential of different fluorinated compounds: 2-fluoropyridine, 3-fluoropyridine and penta-fluoropyridine. While in the case of the molecular complex between water and 2-fluoropyridine and 3-fluoropyridine the geometry of the complex with one water molecule is analogous to that of pyridine with the water molecule linked to the pyridine nitrogen, the case of pentafluoropyridine reveals the effect of perfluorination and the water oxygen points towards the positive center of the pyridine ring. Additional molecular adducts with a molecule of water have been analyzed (benzylamine-water and acrylic acid-water) in order to reveal the stabilizing driving forces that characterize these complexes.

Internal characteristics, chemical compounds and spectroscopy of sapphire as single crystals

In this study more than 450 natural sapphire samples (most of basaltic type) collected from 19 different areas were examined. They are from Dak Nong, Dak Lak, Quy Chau, two unknown sources from the north (Vietnam); Bo Ploi, Khao Ploi Waen (Thailand); Ban Huay Sai (Laos); Australia; Shandong (China); Andapa, Antsirabe, Nosibe (Madagascar); Ballapana (Sri Lanka); Brazil; Russia; Colombia; Tansania and Malawi. rnThe samples were studied on internal characteristics, chemical compositions, Raman-, luminescence-, Fourier transform infrared (FTIR)-, and ultraviolet-visible-near infrared (UV-Vis-NIR)- spectroscopy. The internal features of these sapphire samples were observed and identified by gemological microscope, con focal micro Raman and FTIR spectroscopy. The major and minor elements of the samples were determined by electron probe microanalysis (EPMA) and the trace elements by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). rnThe structural spectra of sapphire were investigated by con focal Raman spectroscopy. The FTIR spectroscopy was used to study the vibration modes of OH-groups and also to determine hydrous mineral inclusions in sapphire. The UV-Vis-NIR absorption spectroscopy was used to analyze the cause of sapphire color. rnNatural sapphires contain many types of mineral inclusions. Typically, they are iron-containing inclusions like goethite, ilmenite, hematite, magnetite or silicate minerals commonly feldspar, and often observed in sapphires from Asia countries, like Dak Nong, Dak Lak in the south of Vietnam, Ban Huay Sai (Laos), Khao Ploi Waen and Bo Ploi (Thailand) or Shandong (China). Meanwhile, CO2-diaspore inclusions are normally found in sapphires from Tansania, Colombia, or the north of Vietnam like Quy Chau. rnIron is the most dominant element in sapphire, up to 1.95 wt.% Fe2O3 measured by EPMA and it affects spectral characteristics of sapphire.rnThe Raman spectra of sapphire contain seven peaks (2A1g + 5Eg). Two peaks at about 418.3 cm-1 and 577.7 cm-1 are influenced by high iron content. These two peaks shift towards smaller wavenumbers corresponding to increasing iron content. This shift is showed by two equations y(418.3)=418.29-0.53x andy(577.7)=577.96-0.75x, in which y is peak position (cm-1) and x is Fe2O3 content (wt.%). By exploiting two these equations one can estimate the Fe2O3 contents of sapphire or corundum by identifying the respective Raman peak positions. Determining the Fe2O3 content in sapphire can help to distinguish sapphires from different origins, e.g. magmatic and metamorphic sapphire. rnThe luminescence of sapphire is characterized by two R-lines: R1 at about 694 nm and R2 at about 692 nm. This characteristic is also influenced by high iron content. The peak positions of two R-lines shift towards to smaller wavelengths corresponding to increasing of iron content. This correlation is showed by two equations y(R_2 )=692.86-0.049x and y(R_1 )=694.29-0.047x, in which y is peak position (nm) of respective R-lines and x is Fe2O3 content (wt.%). Two these equations can be applied to estimate the Fe2O3 content of sapphire and help to separate sapphires from different origins. The luminescence is also applied for determination of the remnant pressure or stress around inclusions in Cr3+-containing corundum by calibrating a 0-pressure position in experimental techniques.rnThe infrared spectra show the presence of vibrations originating from OH-groups and hydrous mineral inclusions in the range of 2500-4000 cm-1. Iron has also an effect upon the main and strongest peak at about 3310 cm-1. The 3310 cm-1 peak is shifted to higher wavenumber when iron content increases. This relationship is expressed by the equation y(3310)=0.92x+3309.17, in which y is peak position of the 3310 cm-1 and x is Fe2O3 content (wt.%). Similar to the obtained results in Raman and luminescence spectra, this expression can be used to estimate the Fe2O3 content and separate sapphires from different origins. rnThe UV-Vis-NIR absorption spectra point out the strong and sharp peaks at about 377, 387, and 450 nm related to dispersed Fe3+, a broad band around 557 and 600 nm related to intervalence charge transfer (IVCT) Fe2+/Ti4+, and a broader band around 863 nm related to IVCT of Fe2+/Fe3+. rnGenerally, sapphires from different localities were completely investigated on internal features, chemical compounds, and solid spectral characteristics. The results in each part contribute for identifying the iron content and separate sapphires from different localities order origins. rn

The Extremely Red, Young L Dwarf PSO J318.5338-22.8603: a Free-Floating Planetary-Mass Analog to Directly Imaged Young Gas-Giant Planets

We have discovered using Pan-STARRS1 an extremely red late-L dwarf, which has (J - K)(MKO) = 2.78 and (J - K) (2MASS) = 2.84, making it the reddest known field dwarf and second only to 2MASS J1207-39b among substellar companions. Near-IR spectroscopy shows a spectral type of L7 +/- 1 and reveals a triangular H-band continuum and weak alkali (K I and Na I) lines, hallmarks of low surface gravity. Near-IR astrometry from the Hawaii Infrared Parallax Program gives a distance of 24.6 +/- 1.4 pc and indicates a much fainter J-band absolute magnitude than field L dwarfs. The position and kinematics of PSO J318.5-22 point to membership in the beta Pic moving group. Evolutionary models give a temperature of 1160(-40)(+30) K and a mass of 6.5(-1.0)(+1.3) M-Jup, making PSO J318.5-22 one of the lowest mass free-floating objects in the solar neighborhood. This object adds to the growing list of low-gravity field L dwarfs and is the first to be strongly deficient in methane relative to its estimated temperature. Comparing their spectra suggests that young L dwarfs with similar ages and temperatures can have different spectral signatures of youth. For the two objects with well constrained ages (PSO J318.5-22 and 2MASS J0355+11), we find their temperatures are approximate to 400 K cooler than field objects of similar spectral type but their luminosities are similar, i.e., these young L dwarfs are very red and unusually cool but not "underluminous." Altogether, PSO J318.5-22 is the first free-floating object with the colors, magnitudes, spectrum, luminosity, and mass that overlap the young dusty planets around HR 8799 and 2MASS J1207-39

CH4, CO, and H2O spectroscopy for the Sentinel-5 Precursor mission: an assessment with the Total Carbon Column Observing Network measurements

The TROPOspheric Monitoring Instrument (TROPOMI) will be part of ESA's Sentinel-5 Precursor (S5P) satellite platform scheduled for launch in 2015. TROPOMI will monitor methane and carbon monoxide concentrations in the Earth's atmosphere by measuring spectra of back-scattered sunlight in the short-wave infrared (SWIR). S5P will be the first satellite mission to rely uniquely on the spectral window at 4190–4340 cm−1 (2.3 μm) to retrieve CH4 and CO. In this study, we investigated if the absorption features of the three relevant molecules CH4, CO, and H2O are adequately known. To this end, we retrieved total columns of CH4, CO, and H2O from absorption spectra measured by two ground-based Fourier transform spectrometers that are part of the Total Carbon Column Observing Network (TCCON). The retrieval results from the 4190–4340 cm−1 range at the TROPOMI resolution (0.45 cm−1) were then compared to the CH4 results obtained from the 6000 cm−1 region, and the CO results obtained from the 4190–4340 cm−1 region at the higher TCCON resolution (0.02 cm−1). For TROPOMI-like settings, we were able to reproduce the CH4 columns to an accuracy of 0.3% apart from a constant bias of 1%. The CO retrieval accuracy was, through interference, systematically influenced by the shortcomings of the CH4 and H2O spectroscopy. In contrast to CH4, the CO column error also varied significantly with atmospheric H2O content. Unaddressed, this would introduce seasonal and latitudinal biases to the CO columns retrieved from TROPOMI measurements. We therefore recommend further effort from the spectroscopic community to be directed at the H2O and CH4 spectroscopy in the 4190–4340 cm−1 region.

Biogeochemical variability during the past 3.6 million years recorded by FTIR spectroscopy in the sediment record of Lake El'gygytgyn, Far East Russian Arctic

Abstract. A number of studies have shown that Fourier transform infrared spectroscopy (FTIRS) can be applied to quantitatively assess lacustrine sediment constituents. In this study, we developed calibration models based on FTIRS for the quantitative determination of biogenic silica (BSi; n = 420; gradient: 0.9–56.5 %), total organic carbon (TOC; n = 309; gradient: 0–2.9 %), and total inorganic carbon (TIC; n = 152; gradient: 0–0.4 %) in a 318 m-long sediment record with a basal age of 3.6 million years from Lake El’gygytgyn, Far East Russian Arctic. The developed partial least squares (PLS) regression models yield high cross-validated (CV) R2 CV = 0.86–0.91 and low root mean square error of crossvalidation (RMSECV) (3.1–7.0% of the gradient for the different properties). By applying these models to 6771 samples from the entire sediment record, we obtained detailed insight into bioproductivity variations in Lake El’gygytgyn throughout the middle to late Pliocene and Quaternary. High accumulation rates of BSi indicate a productivity maximum during the middle Pliocene (3.6–3.3 Ma), followed by gradually decreasing rates during the late Pliocene and Quaternary. The average BSi accumulation during the middle Pliocene was �3 times higher than maximum accumulation rates during the past 1.5 million years. The indicated progressive deterioration of environmental and climatic conditions in the Siberian Arctic starting at ca. 3.3 Ma is consistent with the first occurrence of glacial periods and the finally complete establishment of glacial–interglacial cycles during the Quaternary.

Independent measurement of biogenic silica in sediments by FTIR spectroscopy and PLS regression

We present an independent calibration model for the determination of biogenic silica (BSi) in sediments, developed from analysis of synthetic sediment mixtures and application of Fourier transform infrared spectroscopy (FTIRS) and partial least squares regression (PLSR) modeling. In contrast to current FTIRS applications for quantifying BSi, this new calibration is independent from conventional wet-chemical techniques and their associated measurement uncertainties. This approach also removes the need for developing internal calibrations between the two methods for individual sediments records. For the independent calibration, we produced six series of different synthetic sediment mixtures using two purified diatom extracts, with one extract mixed with quartz sand, calcite, 60/40 quartz/calcite and two different natural sediments, and a second extract mixed with one of the natural sediments. A total of 306 samples—51 samples per series—yielded BSi contents ranging from 0 to 100 %. The resulting PLSR calibration model between the FTIR spectral information and the defined BSi concentration of the synthetic sediment mixtures exhibits a strong cross-validated correlation ( R2cv = 0.97) and a low root-mean square error of cross-validation (RMSECV = 4.7 %). Application of the independent calibration to natural lacustrine and marine sediments yields robust BSi reconstructions. At present, the synthetic mixtures do not include the variation in organic matter that occurs in natural samples, which may explain the somewhat lower prediction accuracy of the calibration model for organic-rich samples.

Sediment physicochemical properties condition pollutant association : a multivariate study of polybrominated diphenyl ethers on the Mendoza River irrigation areas

This work is a multidisciplinary environmental study that provides new insights into the relationships between sediment-organic matter characteristics and polybrominated diphenyl ethers (PBDEs) concentration. The aim of the present multivariate study was to correlate factors influencing PBDEs accumulation in sediment by using principal component analysis (PCA). Organic matter studies by Fourier Transform-Infrared spectroscopy and physicochemical analyses (Total Organic Carbon, pH, electrical conductivity) of sediment samples were considered for PCA. Samples were collected from an artificial irrigation network on the Mendoza River irrigation areas. PCA provided a comprehensive analysis of the studied variables, identifying two components that explained 63% of the data variance. Those factors were mainly associated to organic matter degradation degree, which represent a new insight into the relationships between organic matter in sediments and PBDEs fate. In this sense it was possible to determine that not only the content but also the type of organic matter (chemical structure) could be relevant when evaluating PBDEs accumulation and transport in the environment. Typification of organic matter may be a useful tool to predict more feasible areas where PBDE, may accumulate, as well as sediment transportation capability.

Magnetic parameters of rocks from the Red Sea rift zone

Results of detailed geomagnetic and geomorphological studies carried out by R/V Akvanavt together with data obtained by a side-scanning sonar and high-frequency profiles from a towed Zvuk-4 vehicle plus results of visual observations of deep-sea manned Pisces submersible have shown that the spreading axis is divided into segments, whose strike (330°) differs from the overall strike (310°) of the axial magnetic anomaly. In the study area segments are about 1 km long and transform displacements are 0.5 km. Calculations on a model have shown that spreading is asymmetric: during the Brunhes epoch accretion rate of the African Plate was 6 mm/yr and that of the Arabian Plate 7 mm/yr. Earlier it had been 9 and 11 mm/yr, respectively.

Nondestructive quantification of chemical and physical properties of fruits by time-resolved reflectance spectroscopy in the wavelength range 650-1000 nm

Time-resolved reflectance spectroscopy can be used to assess nondestructively the bulk (rather than the superficial) optical properties of highly diffusive media. A fully automated system for time-resolved reflectance spectroscopy was used to evaluate the absorption and the transport scattering spectra of fruits in the red and the near-infrared regions. In particular, data were collected in the range 650-1000 nm from three varieties of apples and from peaches, kiwifruits, and tomatoes. The absorption spectra were usually dominated by the water peak near 970 nm, whereas chlorophyll was detected at 675 nm. For ail species the scattering decreased progressively with increasing wavelength. A best fit to water and chlorophyll absorption line shapes and to Mie theory permitted the estimation of water and chlorophyll content and the average size of scattering centers in the bulls; of intact fruits.

El origen de Internet. El camino hacia la red de redes.

Motivación Internet es sin duda sinónimo de telecomunicaciones en este momento, es la tecnología no de futuro, sino de presente llamada a cambiar la sociedad hasta puntos insospechables, sin opción de retorno. Hoy en día ha cambiado la forma en la que nos relacionamos, la forma en la que trabajamos y la manera en que tomamos decisiones se ve fuertemente apoyada en esta herramienta. Por supuesto el devenir de la Red está por ver, los gobiernos y las grandes compañías quieren "meter mano" en el control de los contenidos, sin embargo parece que la Red sabe autogestionarse y es capaz de funcionar dentro de un modelo semi-anárquico. Objetivos El objetivo del presente proyecto es dar a conocer los orígenes de la red de redes, desarrollando un entorno social, político, económico y tecnológico para una mejor comprensión. El lector no obtendrá un extenso conocimiento técnico sobre redes y ordenadores, sin embargo será capaz de entender los verdaderos motivos que llevaron a una comunidad científica a crear la mayor herramienta para el desarrollo del ser humano. También es mi intención hacer que el lector reflexione sobre cómo influyen diferentes factores en el devenir de los hechos, momentos de grandes cambios sociales o políticos, o cómo la ciencia resuelve problemas mediante la observación o el análisis, buscando siempre la mejor opción, sin conformarse con soluciones a medias. Estructura El proyecto está estructurado en 3 grandes bloques. El primer bloque corresponde a los tres primeros capítulos que nos adentran en el tema vía una introducción a modo de punto de partida u origen del concepto, un marco histórico del período de formación de la Red y un pequeño análisis del estado del arte de los ordenadores desde sus orígenes como tal, prácticamente coetáneos con el origen de Internet. El segundo bloque narra cómo comienza el desarrollo de la Red, los pasos que se van dando y las soluciones adoptadas hasta llegar a lo que conocemos hoy día como la red de redes: Internet. Por último se detallan las conclusiones obtenidas tras la escritura de este documento, realizando una serie de reflexiones globales que me surgen tras conocer la historia de la Red. ABSTRACT. Motivation Nowadays Internet without any doubt means telecommunications. It is not the future technology but the present one and it is supposed to change the society to an unexpected point, without possibility of return. It has already changed the way we communicate each other, the way we work and also the way we take decisions are strongly hold by this tool. Meanwhile we will see the becoming of the Network, the governments and the big companies want to have the control over the contents, however it seems that the Network has the ability to self-manage and it is also capable to keep working in a semi-anarchic model. Objectives The main aim of the present project is to show what is the real origin of the network of networks, developing a social, politic, economic and technologic context of it to ensure a better comprehension. The reader won´t get an extended knowledge about computing or networking, however he or she will be able to understand the truly motivation that lead a scientific community to create the most important tool for the human development. It is also my intention to make the reader think about how different facts, depending on the moment they take place like social or political changes, can transform the way everything happens and how science solves problems by the observation and the analysis, searching always the best option, without comply with half solutions. Structure This project is divided into three sections. The first part which includes the three first chapters place us in the topic by an introduction of the concept origin, an historic context of the period of Network development and a small analysis of the state of the art in computing since its origins, which appear at the same time as the Internet. The second block explains how the development of the Net starts, the steps followed and the solutions taken until the arrival of the network of networks we all know: the Internet. Finally, we can find the conclusions, which are exposed in a reflection way, with some considerations that came to me after writing this document about the history of the Internet.