LIBS spectroscopy meets the ocean. Chemical analysis of archeological materials in Mediterranean waters

After decades of development in laboratories and land operations, chemical analysis of submerged objects is starting to become a reality. While the analysis of water at variable depth has been demonstrated in the past using florescence spectroscopy and Raman spectroscopy, determination of the atomic composition of submerged objects is much a more complex task. Technology based on laser-induced breakdown spectroscopy (LIBS) has been recently developed for such sub-sea operations. This paper will discuss the operating parameters of a marine LIBS analyzer. Metals, alloys, rocks, marble, concrete, can be analyzed at a depth of up to 50 m. The system has been tested in several coastal surveys in Mediterranean waters.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

LIBS detection of atoms and molecules in nanoplasmas of levitated particles

Single particle characterization still constitutes a challenge to contemporary chemical analysis. Considerable effort worldwide is being devoted to conceive experimental strategies providing detection capabilities compatible with the extremely low mass of micro- and nano-particles and the ability to determine the chemical composition of the individual entities. The notion of using optical levitation to trap individual particles was demonstrated in the past century. Recently we have proposed the multielemental analysis of individual nanoparticles in optical traps using LIBS. In this lecture, the fundamentals of optical trapping of nanoparticles in air will be presented. The specific excitation and ionization processes leading to efficient optical detection and an analysis of the photon emission efficiency will be discussed. Finally, some limiting factors involved in our approach and prospective directions for improvement will be presentedUniversidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Multielemental analysis in nanoplasmas of isolated particles in an optical trap

Single particle characterization still constitutes a challenge to contemporary chemical analysis. Considerable effort worldwide is being devoted to conceive experimental strategies providing detection capabilities compatible with the extremely low mass of micro- and nano-particles and the ability to determine the chemical composition of the individual entities. The notion of using optical levitation to trap individual particles was demonstrated in the past century. Recently we have proposed the multielemental analysis of individual nanoparticles in optical traps using LIBS. In this lecture, the fundamentals of optical trapping of nanoparticles in air will be presented. The specific excitation and ionization processes leading to efficient optical detection and an analysis of the photon emission efficiency will be discussed. Finally, some limiting factors involved in our approach and prospective directions for improvement will be presented.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Chemistry in the laser-induced plasma

Since the first uses of LIBS, it is known that the laser induced plasma, as many other atom reservoirs, is a dynamic system that evolves rapidly to stable species after the end of the laser pulse. LIBS of metallic targets, which is the best established body of knowledge in this area of research, reveals the existence of a limited number of reactions between the excited and ionized atoms and atmospheric oxygen. The oxides formed may be used for characterizing the original sample, as for instance using the recently demonstrated application of LIBS for isotopic analysis at atmospheric pressure. The case of LIBS of organic compounds is much more complex. Recent investigations reveal that reactions in the plasma between fragments formed by dissociation of the original compound and by reactions of these fragments with the gas surrounding the plasma are extensive. While these reactions tend to complicate the spectroscopy and its interpretation, the products formed and the way they interact can be exploited for assigning the identity of the original compound. In this talk, a discussion of the several factors affecting the plasma chemistry of a number of molecular compounds will be presented. Factors influencing the formation of emitting species and some applications in the chemical analysis of organic samples will be discussed.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

From the sea bottom to the red planet with laser-induced breakdown spectroscopy

Laser-induced breakdown spectroscopy (LIBS) constitutes one of the most active research fields in analytical science. Among several important features, ability for adaptation to radically different scenarios constitutes its most valuable asset. For instance, technology based on LIBS has been developed for sub-sea operations and for planetary exploration, two extreme environments that require analytical solutions not available for most measurement techniques. In this talk, a discussion will be presented on the challenges represented by these analyses and the solutions envisaged using advanced LIBS approaches.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Spectral identification in the attogram regime through laser induced breakdown spectroscopy of single optically-trapped nanoparticles in air

Current trends in nanoengineering are bringing along new structures of diverse chemical compositions that need to be meticulously defined to ensure their correct operation. Few methods can provide the sensitivity required to carry out measurements on individual nanosubjects without tedious sample pre-treatment or data analysis. In the present study, we introduce a pathway for the full elemental identification of single nanoparticles that avoids suspension in liquid media by means of optical trapping and laser-induced plasma spectroscopy. We demonstrate spectroscopic detection and identification of individual Cu nanoparticles of masses down to 73 attograms and report, for the first time, stable optical trapping in air and manipulation of Cu particles from 25 to 70 nm in diameter. We found an increase in the absolute number of photons produced as size of the particles decreased; pointing towards a more efficient excitation of ensembles of only 7 x exp(-5) Cu atoms in the onset plasma.Universidad de Málaga. Campus de Excelencia Internacional Andalucia Tec

Going Places

Artist Statement I forget my keys and usually misplace my telephone but I know exactly where my camera is at any given moment. I capture moments for my artwork as well as my own personal benefit. Not all the images will be translated into paint or clay and not all the images are those filled with beauty. However, a bicycle leaning on the corner of a house in Key West and a two hundred dollar pair of shoes from when I was single are a few of the memories that evolved from snapshot to artwork. My photographs inspire my colorful paintings and patterned clay work. I use them as a way to document my personal journeys and evolution of my life

OC-OT-LIBS: A novel approach to the chemical characterization of single particles

Spectral identification of individual micro- and nano-sized particles by the sequential intervention of optical catapulting, optical trapping and laser-induced breakdown spectroscopy is presented [1]. The three techniques are used for different purposes. Optical catapulting (OC) serves to put the particulate material under inspection in aerosol form [2-4]. Optical trapping (OT) permits the isolation and manipulation of individual particles from the aerosol, which are subsequently analyzed by laser-induced breakdown spectroscopy (LIBS). Once catapulted, the dynamics of particle trapping depends on the laser beam characteristics (power and intensity gradient) and on the particle properties (size, mass and shape). Particles are stably trapped in air at atmospheric pressure and can be conveniently manipulated for a precise positioning for LIBS analysis. The spectra acquired from the individually trapped particles permit a straightforward identification of the inspected material. The current work focuses on the development of a procedure for simultaneously acquiring dual information about the particle under study via LIBS and time-resolved plasma images by taking advantage of the aforementioned features of the OC-OT-LIBS instrument to align the multiple lines in a simple yet highly accurate way. The plasma imaging does not only further reinforce the spectral data, but also allows a better comprehension of the chemical and physical processes involved during laser-particle interaction. Also, a thorough determination of the optimal excitation conditions generating the most information out of each laser event was run along the determination of parameters such as the width of the optical trap, its stability as a function of the laser power and the laser wavelength. The extreme sensibility of the presented OC-OT-LIBS technology allows a detection power of attograms for single/individual particle analysis.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Socio-Political Conflict and Economic Performance in Bolivia

We examine how socio-political conflict in Bolivia has affected its economic performance since the 1970s. Such conflict includes strikes, demonstrations, road blockades, and conventional rent-seeking. Since conflict has costs, it diverts resources away from production, tends to reduce investment and could therefore reduce economic growth. We first review the characteristics of conflict in Bolivia using a unique data set. We then provide estimates of the direct costs of conflict and examine the relationship with economic performance using hypotheses derived from a simple model. In particular, we make a distinction between economic growth that is due to external factors – like changes in income due to movements in the terms of trade – and economic growth that is due to productive investment. Growth due to external factors tends to be positively related to conflict, whereas growth due to productive investment should be negatively related to conflict. Finally, we discuss how levels of conflict, economic performance, and governance might be related in Bolivia’s recent history.economic growth, property rights, governance

La labor policial en la detección del engaño: realidad y mitos

En el momento en que se comete un delito, es de total importancia la labor policial de investigación para identificar y detener al responsable de éste. A la hora de averiguar quién es el culpable se deben realizar diferentes tareas encomendadas a la detección del engaño para poder solucionar el caso con éxito. Este trabajo pretende dar a conocer diferentes estudios encaminados a conocer la realidad de la labor policial en la detección del engaño, planteando si realmente, éstos agentes están capacitados para detectar mentiras y verdades; las variables que influyen a la hora de ésta detección, las técnicas que se utilizan y si éstas son realmente exitosas, etc. En definitiva, tratar de aportar datos sobre un tema del que parece ser, la sociedad no está informada y que es de total importancia ya que se juegan aspectos legales importantes y si la labor de detección del engaño no se realiza correctamente, puede poner en riesgo a personas inocentes que podrían ser declaradas como culpables de un hecho delictivo