Femtosecond time-resolved phase-change microscopy and ablation threshold calculations to understand ultrafast laser ablation

El trabajo recoge experimentos realizados en una configuración sonda-prueba haciendo uso de un láser de femtosegundos, con el objetivo de comprender los fenómenos de ablación de materiales sólidos ras irradiación con láseres de pulso ultracorto.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Prilog istraživanju promjena na škrgama zebrice (Danio rerio) prilikom izloženosti dioksinu

This study determined cell changes in the gills of zebrafish (Danio rerio, Hamilton, 1822) as a result of a dietary supply of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). 50 zebrafish were divided into five groups, one control group and four experimental ones. The experimental groups were supplied 10, 40, 100 and 270 ng/day/fish TCDD, respectively. Structural, ultrastructural and morphometric studies of the fish gill were carried out, indicating that, in low concentrations, fish gills presented hyperemia with progressive erosion of the endothelium of the capillaries resulting in edema and microhaemorrhages. In the non-respiratory gill, in those groups with low concentrations, it could be observed that the chloride cells presented hypertrophy as a result of dilatation of the intracellular canal and swelling of the microvilli, losing their activity in the degradation of chemical substances (according to some authors) in those groups with a higher concentration. Mucous cells presented hyperplasia and hypertrophy. The sensory buds were not directly affected, but, due to the presence of interstitial edema, swelling of the supporting cells occurred without the involvement of the neurosensory cells. We concluded that dioxins affect the gills to a greater or lesser extent depending on their concentration in the fish’s diet, which alters their functionality.Ovim istraživanjem utvrđene su promjene na stanicama škrga zebrice (Danio rerio, Hamilton, 1822) kao rezultat hranjena 2,3,7,8 tetraklorodibenzo p-dioksinom (TCDD). Pedeset jedinki zebrice podijeljeno je u pet grupa, jednu kontrolnu grupu i četiri eksperimentalne. Eksperimentalnim grupama davano je 10, 40, 100 i 270 ng/riba/dan TCDD. Provedena su strukturalna, ultrastrukturalna i morfološka istraživanja škrga ribe, ukazujući da su škrge riba pokazivale hiperemiju s progresivnom erozijom endotel kapilara koja je rezultirala edemima i mikrokrvarenjima. Kod grupa kojima je dana manja koncentracija, u škrgama koje ne služe za disanje može se primijetiti da kloridne stanice pokazuju hipertrofiju kao posljedicu dilatacije međustaničnog kanala i oticanje mikroresica kojima se smanjuje aktivnost tijekom razgradnje kemijskih tvari (prema mišljenjima nekih autora) u onim grupama koje su bile izložene većim koncentracijama. Mukozne stanice pokazuju hiperplaziju i hipertrofiju. Osjetni pupoljci nisu bili izravno pogođeni, ali, zbog prisutnosti intersticijskog edema, oticanja potpornih stanica bez uključivanja neurosenzornih stanica. Zaključak je da dioksini utječu na škrge u većoj ili manjoj mjeri ovisno o njihovoj koncentraciji u ishrani ribe, što mijenja njihovu funkcionalnost

Prilog istraživanju promjena na škrgama zebrice (Danio rerio) prilikom izloženosti dioksinu

This study determined cell changes in the gills of zebrafish (Danio rerio, Hamilton, 1822) as a result of a dietary supply of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). 50 zebrafish were divided into five groups, one control group and four experimental ones. The experimental groups were supplied 10, 40, 100 and 270 ng/day/fish TCDD, respectively. Structural, ultrastructural and morphometric studies of the fish gill were carried out, indicating that, in low concentrations, fish gills presented hyperemia with progressive erosion of the endothelium of the capillaries resulting in edema and microhaemorrhages. In the non-respiratory gill, in those groups with low concentrations, it could be observed that the chloride cells presented hypertrophy as a result of dilatation of the intracellular canal and swelling of the microvilli, losing their activity in the degradation of chemical substances (according to some authors) in those groups with a higher concentration. Mucous cells presented hyperplasia and hypertrophy. The sensory buds were not directly affected, but, due to the presence of interstitial edema, swelling of the supporting cells occurred without the involvement of the neurosensory cells. We concluded that dioxins affect the gills to a greater or lesser extent depending on their concentration in the fish’s diet, which alters their functionality.Ovim istraživanjem utvrđene su promjene na stanicama škrga zebrice (Danio rerio, Hamilton, 1822) kao rezultat hranjena 2,3,7,8 tetraklorodibenzo p-dioksinom (TCDD). Pedeset jedinki zebrice podijeljeno je u pet grupa, jednu kontrolnu grupu i četiri eksperimentalne. Eksperimentalnim grupama davano je 10, 40, 100 i 270 ng/riba/dan TCDD. Provedena su strukturalna, ultrastrukturalna i morfološka istraživanja škrga ribe, ukazujući da su škrge riba pokazivale hiperemiju s progresivnom erozijom endotel kapilara koja je rezultirala edemima i mikrokrvarenjima. Kod grupa kojima je dana manja koncentracija, u škrgama koje ne služe za disanje može se primijetiti da kloridne stanice pokazuju hipertrofiju kao posljedicu dilatacije međustaničnog kanala i oticanje mikroresica kojima se smanjuje aktivnost tijekom razgradnje kemijskih tvari (prema mišljenjima nekih autora) u onim grupama koje su bile izložene većim koncentracijama. Mukozne stanice pokazuju hiperplaziju i hipertrofiju. Osjetni pupoljci nisu bili izravno pogođeni, ali, zbog prisutnosti intersticijskog edema, oticanja potpornih stanica bez uključivanja neurosenzornih stanica. Zaključak je da dioksini utječu na škrge u većoj ili manjoj mjeri ovisno o njihovoj koncentraciji u ishrani ribe, što mijenja njihovu funkcionalnost

Algunos datos nuevos sobre las relaciones Iglesia-Estado durante la Segunda República Española. Documentación inédita del Nuncio Tedeschini en el Archivo Secreto Vaticano

Se pretende mostrar la importancia que para el estudio y la investigación de las relaciones entre la Iglesia católica y la Segunda República tendrán los fondos puestos a consulta recientemente en el Archivo Secreto Vaticano. Se han seleccionado dos momentos de especial trascendencia. En primer lugar, la proclamación de la Segunda República. Los telegramas cifrados cruzados ente la Secretaría de Estado y Tedeschini, aportan datos no conocidos y de bastante relieve. En segundo lugar la aprobación por las Cortes, del que habría de ser el artículo 26 de la Constitución de 1931. En un extenso informe (que se transcribe íntegramente) el Nuncio Tedeschini relata cómo fueron los acontecimientos. Los testimonios históricos sobre la existencia (Alcalá-Zamora) o no (Azaña) de un acuerdo entre el Gobierno provisional y la jerarquía eclesiástica, eran contradictorios. Este nuevo testimonio corrobora su existencia: el Nuncio no duda en hablar de traición, refiriéndose en especial a Azaña. ------ It aims to show the importance of the collections recently available in the Vatican Secret Archive for the study and investigation of the relations between the Catholic Church and the Second Republic. Two moments of special transcendence have been selected. First is the proclamation of the Second Republic. The encoded telegrams exchanged between tge Secretary of State and Tedeschini offer unknown data of quite relevance. Second is the approval by the 'Cortes', of which the article 26 of the Constitution of 1931 would have been. In an extensive report (which is transcribed completely), Nuncio Tedeschini relates how the events were. The historical testimonies about the existence (Alcalá-Zamora) or non-existence (Azaña) of an agreement between the provisional government and the ecclesiastical hierarchy were contradictories. This new testimony corroborates its existence: the Nuncio does not doubt in speaking about betrayal, specially referring to Azaña

Time-resolved laser-induced phase change microscopy: understanding laser-matter effects at the femtosecond scale

LA comunicación describe el desarrollo instrumental y las aplicaciones con un microscopio de cambio de fase con resolución de femtosegundos que se ha puesto a punto en el LAboratorio LAser de la UMAUniversidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Temporal and energetic scale of solid matter interaction phenomena occurring during femtosecond ablation of solids

Ablation using femtosecond lasers exhibits significant differences with that at the nanosecond timescale, where the concurrence of photochemical and photothermal processes taking place during the photon absorption govern the process. In the ultrashort regime, the several phenomena involved in the laser-matter interaction are markedly different. Thus, a prior comprehension of the processes is required in order to extend the range of current applications and improve the analytical results. Our current studies are facing fundamental and applied studies with the aim of better understanding laser-matter interaction processes in condensed phase using femtosecond lasers. To achieve this goal, we have designed experimental strategies expecting to improve the knowledge of the timescale and onset generation of chemical species and surface alterations during femtosecond ablation of solids. Time-resolved optical emission spectroscopy, time-of-flight mass spectrometry and time-resolved phase-change microscopy are currently implemented. The combined use of the cited techniques is allowing the experimental determination of the energy threshold, temporal regime and macroscopic effects occurring in a variety of materials as a consequence of the interaction with an ultra-short laser pulse. The core of the experiment is a 80 Mhz, 100 nJ, 400 fs Ti-Saphire oscillator that is additionally subjected to chirped pulse amplification to produce an output of 3,5 mJ at 35 fs and a maximum repletion rate of 1 KHz. Different wavelengths (800, 400 and 266 nm) are achievable. An intensified CCD and a dual-state reflectron equipped with a cassegrain reflective optics are used for the analysis of the photons and ion generated after laser irradiation. Additionally, a pump-probe microscope with a temporal resolution better than 500 fs has been designed to allow time-resolved studies of phase-change in the ablated samples.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

Geodetic works carried out in the Strait of Gibraltar

The proximity between Europe and Africa and the fact that the Strait of Gibraltar has historically acted as a link between races, cultures and religions have made absolutely necessary to establish a relationship between the Northern African coast and the Southern European equivalent. From the Nineteenth Century the possibility of building a permanent link between both continents through the Strait of Gibraltar has been taken into account. In order to establish that relationship it is necessary to have coastal zones completely geo-referenced, under the same geodetic system and with a unique projection system. The paper describes the work carried out in the Strait of Gibraltar for this purpose

Differential laser-matter interaction in the ablation of solid samples with laser pulses in the interval between 35 fs – 4 ps.

Our communication is focused on the influence of the pulse width in the laser-matter interaction during laser ablation of solid materials. The experiments were performed with an 80 MHz, 100 nJ, 400 fs Ti-Saphire oscillator, amplified to produce an output of 3,5 mJ at 35 fs and a maximum repletion rate of 1 KHz. Modifications in the stretcher-compressor have allowed the continuous selection of amplified pulses in the range between 35 fs to 4 ps. The pulses are subjected to measurements in the autocorrelation, spectral bandwidth and energy per pulse. A 0.5 m focal-length spectrograph fitted with an intensified CCD or fast single-channel detectors is used to determine the time constants, to establish the fluence threshold, and to record multi-channel spectra from the generated plasmas. Additionally, morphological characterization making use of optical and electron microscopy were performed. The effect of the longer laser pulses in the laser-matter interaction - particularly in the extension of the heat-affected zone - and its implication in depth-profiling studies was also checked. For such purpose, a layered sample with a defined structure was analyzed by laser-induced breakdown spectroscopy under different pulse widths conditions. The effect on the averaged ablation rate, depth resolution and layer mixing will be commented.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Phobos eclipse detection on Mars : theory and practice

We present a general approach to study solar eclipses by Phobos on Mars: its parameterization and prediction.The validation of the model and the involved parameters is made with the already observed eclipses by previous Mars missions. Eclipse prediction is applied for the past Mars lander missions: Viking, Pathfinder and Phoenix, as well as for the future Mars MetNet Precursor Mission. A successful detection of eclipses could be used for the localization of landers and to study atmospheric properties. We also consider the data analysis, with special emphasis in the tomographic method to identify events which are very localized in space and time. Large computation requirements are needed for the implemented methods. To this propose an efficient Cloud Computing Network Infrastructure has been used.Esittelemme yleisen lähestymistavan Phoboksen auringonpimennysten tutkimiseen, parametrisointiin ja ennustamiseen. Mallin ja sen parametrien validointi tehdään menneiden ja nykyisten Mars-missioiden havaitsemien pimennysten avulla. Pimennysten ennustamista käytetään menneisiin Viking-, Pathfinder- ja Phoenix-laskeutujiin, samoin kuin tulevaan Mars MetNet Precursor missioon. Pimennysten onnistuneita havaintoja voitaisiin käyttää laskeutujien paikantamiseen ja kaasukehän ominaisuuksien tutkimiseen. Käsittelemme myös data-analyysiä, painottaen erityisesti tomografiamenetelmää, havaitaksemme tapahtumia jotka ovat paikallisia ajan ja sijainnin suhteen. Menetelmien toteuttamiseen vaaditaan suuri laskentakapasiteetti. Tämän toteuttamiseen on käytetty pilvilaskentaa