Atmospheric Thermodynamic Profiling through the Use of a Micro-Pulse Raman Lidar System: Introducing the Compact Raman Lidar MARCO

It was for a long time believed that lidar systems based on the use of high-repetition micro-pulse lasers could be effectively used to only stimulate atmospheric elastic backscatter echoes, and thus were only exploited in elastic backscatter lidar systems. Their application to stimulate rotational and roto-vibrational Raman echoes, and consequently, their exploitation in atmospheric thermodynamic profiling, was considered not feasible based on the technical specifications possessed by these laser sources until a few years ago. However, recent technological advances in the design and development of micro-pulse lasers, presently achieving high UV average powers (1–5 W) and small divergences (0.3–0.5 mrad), in combination with the use of large aperture telescopes (0.3–0.4 m diameter primary mirrors), allow one to presently develop micro-pulse laser-based Raman lidars capable of measuring the vertical profiles of atmospheric thermodynamic parameters, namely water vapor and temperature, both in the daytime and night-time. This paper is aimed at demonstrating the feasibility of these measurements and at illustrating and discussing the high achievable performance level, with a specific focus on water vapor profile measurements. The technical solutions identified in the design of the lidar system and their technological implementation within the experimental setup of the lidar prototype are also carefully illustrated and discussed

Lidar in Space Technology Experiment correlative measurements by lidar in Potenza, southern Italy.

An intensive lidar measurement campaign was carried out in Potenza (40°36′N-15°44′E, 820 m above sea level (asl)) in conjunction with the Lidar in Space Technology Experiment (LITE) mission and primarily aimed at the validation of LITE stratospheric aerosol measurements. Potenza lidar measurements in coincidence with all five nighttime overpasses near southern Italy (September 11, 12, 17, and 18, 1994) are compared with simultaneous LITE data. Potenza lidar data appear to be highly correlated with LITE data both at 355 and 532 nm. Potenza lidar versus LITE measurements of the aerosol-scattering ratio show a correlation coefficient of 0.72–0.81 at 355 nm and 0.88–0.93 at 532 nm, with an average calibration coefficient of 0.92 ± 0.19 at 355 nm and 1.02 ± 0.07 at 532 nm. Comparisons are also made in terms of the average Angstrom coefficient, whose values are consistent with submicrometer aerosol particles. Finally, Potenza lidar measurements of the aerosol layer base and top heights, the peak aerosol-scattering ratio and peak height, as well as of the aerosol scattering ratio at the cloud base appear to be consistent with measurements performed by other ground lidar stations in Europe during the LITE campaign as well as with the LITE data

Intent Classification in Question-Answering Using LSTM Architectures

Question-answering (QA) is certainly the best known and probably also one of the most complex problem within Natural Language Processing (NLP) and artificial intelligence (AI). Since the complete solution to the problem of finding a generic answer still seems far away, the wisest thing to do is to break down the problem by solving single simpler parts. Assuming a modular approach to the problem, we confine our research to intent classification for an answer, given a question. Through the use of an LSTM network, we show how this type of classification can be approached effectively and efficiently, and how it can be properly used within a basic prototype responder.Comment: Presented at the 2019 Italian Workshop on Neural Networks (WIRN'19) - June 201

An Analysis of Word2Vec for the Italian Language

Word representation is fundamental in NLP tasks, because it is precisely from the coding of semantic closeness between words that it is possible to think of teaching a machine to understand text. Despite the spread of word embedding concepts, still few are the achievements in linguistic contexts other than English. In this work, analysing the semantic capacity of the Word2Vec algorithm, an embedding for the Italian language is produced. Parameter setting such as the number of epochs, the size of the context window and the number of negatively backpropagated samples is explored.Comment: Presented at the 2019 Italian Workshop on Neural Networks (WIRN'19) - June 201

Atmospheric Boundary Layer Height: Inter-Comparison of Different Estimation Approaches Using the Raman Lidar as Benchmark

This work stems from the idea of improving the capability to measure the atmospheric boundary layer height (ABLH) in variable or unstable weather conditions or in the presence of turbulence and precipitation events. A new approach based on the use of rotational and roto-vibrational Raman lidar signals is considered and tested. The traditional gradient approach based on the elastic signals at wavelength 532 nm is also considered. Lidar data collected by the University of Basilicata Raman lidar (BASIL) within the Special Observation Period 1 (SOP 1) in Cardillargues (Ceveninnes-CV supersite) during the Hydrological Cycle in the Mediterranean Experiment (HyMeX) were used. Our attention was specifically focused on the data collected during the period 16-21 October 2012. ABLH estimates from the Raman lidar were compared against other innovative methods, such as the recently established Morphological Image Processing Approach (MIPA) and the temperature gradient technique applied to potential temperature obtained from radio-sounding data. For each considered methodology, a statistical analysis was carried out. In general, the results from the different methodologies are in good agreement. Some deviations have been observed in correspondence with quite unstable weather conditions

4-Phenyl-1,2,3-triazoles as Versatile Ligands for Cationic Cyclometalated Iridium(III) Complexes

Five cationic iridium(III) complexes (1-5) were synthesized exploiting two triazole-based cyclometalating ligands, namely, 1-methyl-4-phenyl-1H-1,2,3-triazole (A) and the corresponding mesoionic carbene 1,3-dimethyl-4-phenyl-1H-1,2,3-triazol-5-yliclene (B). From the combination of these two ligands and the ancillary one, i.e., 4,4'-di-tert-butyl-2,2'-bipyridine (for 1-3) or tert-butyl isocyanide (for 4 and 5), not only the typical bis-heteroleptic complexes but also the much less explored tris-heteroleptic analogues (2 and 5) could be synthesized. The redox and emission properties of all of the complexes are effectively fine-tuned by the different ligands: (i) cyclometalating ligand A induces a stronger highest occupied molecular orbital (HOMO) stabilization compared to B and leads to complexes with progressively narrower HOMO-lowest unoccupied molecular orbital (LUMO) and redox gaps, and lower emission energy; (ii) complexes 1-3, equipped with the bipyridine ancillary ligand, display fully reversible redox processes and emit from predominantly metal-to-ligand charge transfer (MLCT) states with high emission quantum yields, up to 60% in polymeric matrix; (iii) complexes 4 and 5, equipped with high-field isocyanide ligands, display irreversible redox processes and high-energy emission from strongly ligand-centered triplets with long emission lifetimes but relatively low quantum yields (below 6%, both in room-temperature solution and in solid state). This work demonstrates the versatility of phenyl-triazole derivatives as cyclometalating ligands with different chelation modes (i.e., C<^>N and C<^>C:) for the synthesis of photoactive iridium(III) complexes with highly tunable properties

EVALUATION OF LIVER PARENCHYMA AND PERFUSION USING DYNAMIC CONTRAST-ENHANCED COMPUTED TOMOGRAPHY AND CONTRAST-ENHANCED ULTRASONOGRAPHY IN CAPTIVE GREEN IGUANAS (IGUANA IGUANA) UNDER GENERAL ANESTHESIA

Background: Contrast-enhanced diagnostic imaging techniques are considered useful in veterinary and human medicine to evaluate liver perfusion and focal hepatic lesions. Although hepatic diseases are a common occurrence in reptile medicine, there is no reference to the use of contrast-enhanced ultrasound (CEUS) and contrast-enhanced computed tomography (CECT) to evaluate the liver in lizards. Therefore, the aim of this study was to evaluate the pattern of change in echogenicity and attenuation of the liver in green iguanas (Iguana iguana) after administration of specific contrast media. Results: An increase in liver echogenicity and density was evident during CEUS and CECT, respectively. In CEUS, the mean \ub1 SD (median; range) peak enhancement was 19.9% \ub1 7.5 (18.3; 11.7-34.6). Time to peak enhancement was 134.0 \ub1 125.1 (68.4; 59.6-364.5) seconds. During CECT, first visualization of the contrast medium was at 3.6 \ub1 0.5 (4; 3-4) seconds in the aorta, 10.7 \ub1 2.2 (10.5; 7-14) seconds in the hepatic arteries, and 15 \ub1 4.5 (14.5; 10-24) seconds in the liver parenchyma. Time to peak was 14.1 \ub1 3.4 (13; 11-21) and 31 \ub1 9.6 (29; 23-45) seconds in the aorta and the liver parenchyma, respectively. Conclusion: CEUS and dynamic CECT are practical means to determine liver hemodynamics in green iguanas. Distribution of contrast medium in iguana differed from mammals. Specific reference ranges of hepatic perfusion for diagnostic evaluation of the liver in iguanas are necessary since the use of mammalian references may lead the clinician to formulate incorrect diagnostic suspicions

Workplace noise exposure and audiometric thresholds in dental technicians

Noise is a well-known risk factor in occupational medicine. Several studies have been performed in workplaces with noise sources, especially in the industrial field; on the contrary, only a few studies have been carried to evaluate the noise exposure effects in non-industrial workplaces such as small factories, handicraft laboratories, and dental laboratories. The aims of this study were to evaluate workplace noise exposure and hearing thresholds in dental technicians. Four laboratories and 51 dental technicians were included in the study. Noise exposure levels during a nominal eight-hour working day (LEX, 8 h) were assessed in the included laboratories. Audiometric thresholds with pure tone audiometry were performed in 51 dental technicians, and results were compared with those expected in subjects not exposed to noise. The environmental noise measures showed moderate differences of the LEX, 8 h among the four laboratories (range 71.4 to 76.2); average LEX, 8 h was 73.9 ± 2.2 dB(A). The audiometric results showed a progressive increase of hearing threshold values at the frequencies mostly involved in noise-induced hearing loss (3, 4 and 6 kHz) and a correlation with age and working seniority especially in males (p<0.005). Nevertheless, in the 92.1% of subjects the threshold increases were in line with those expected in subjects of the same age and sex not exposed to noise and in the remaining 7.8% were not statistically significant (p>0.05). In 3.9% of the cases the increases were bilateral, typical of noise-induced hearing loss, and only 1.9% showed involvement of several frequencies with worsening of expected thresholds >25 dB. In conclusion, our study showed that exposure to noise in dental laboratories was not sufficient to represent a hazard to hearing, as demonstrated by the LEX, 8 h, which were below 80 dB(A) and therefore below the European exposure limit values and exposure action values for workers