Computational Simulation of Thermal and Spattering Phenomena and Microstructure in Selective Laser Melting of Inconel 625

AbstractComputational modelling of Laser Powder Bed Fusion (L-PBF) processes such as Selective laser Melting (SLM) can reveal information that is hard to obtain or unobtainable by in-situ experimental measurements. A 3D thermal field that is not visible by the thermal camera can be obtained by solving the 3D heat transfer problem. Furthermore, microstructural modelling can be used to predict the quality and mechanical properties of the product. In this paper, a nonlinear 3D Finite Element Method based computational code is developed to simulate the SLM process with different process parameters such as laser power and scan velocity. The code is further improved by utilizing an in-situ thermal camera recording to predict spattering which is in turn included as a stochastic heat loss. Then, thermal gradients extracted from the simulations applied to predict growth directions in the resulting microstructure

Species Composition and Seasonality of the Smallest Size Class of Shrimp in the Tortugas Fishery of Florida

Shrimps from the smallest commercial size class (68 or more heads-off shrimp per 454 g) were analyzed from samples collected at the Tortugas fishing grounds from March 2002 through March 2004. Pink shrimp Farfantepenaeus duorarum and yellow roughneck shrimp Rimapenaeus similis occurred together in 90% of the samples, comprising 65.4% and 27.2% of individuals, respectively. Estimates of the proportion and seasonality of both species in the shrimp samples were combined with an analysis of the smallest size class in the Tortugas landings data. Our analysis suggested that yellow roughneck shrimp make up 23.6% by number of the smallest shrimp catch and constitute 6.6% by weight of total shrimp landings, very similar results to those from 1959. Results also indicated that there was a significant difference in the seasonality of each species during the collection period. A follow-up study of this unreported yellow roughneck shrimp is recommended to ensure sound data and good management for this important fishery

Variability in supply and cross-shelf transport of pink shrimp (Farfantepenaeus duorarum) postlarvae into western Florida Bay

The variability in the supply of pink shrimp (Farfantepenaeus duorarum) postlarvae and the transport mechanisms of planktonic stages were investigated with field data and simulations of transport. Postlarvae entering the nursery grounds of Florida Bay were collected for three consecutive years at channels that connect the Bay with the Gulf of Mexico, and in channels of the Middle Florida Keys that connect the southeastern margin of the Bay with the Atlantic Ocean. The influx of postlarvae in the Middle Florida Keys was low in magnitude and varied seasonally and among years. In contrast, the greater postlarval influx occurred at the northwestern border of the Bay, where there was a strong seasonal pattern with peaks in influx from July through September each year. Planktonic stages need to travel up to 150 km eastward between spawning grounds (northeast of Dry Tortugas) and nursery grounds (western Florida Bay) in about 30 days, the estimated time of planktonic development for this species. A Lagrangian trajectory model was developed to estimate the drift of planktonic stages across the SW Florida shelf. The model simulated the maximal distance traveled by planktonic stages under various assumptions of behavior. Simulation results indicated that larvae traveling with the instantaneous current and exhibiting a diel behavior travel up to 65 km and 75% of the larvae travel only 30 km. However, the eastward distance traveled increased substantially when a larval response to tides was added to the behavioral variable (distance increased to 200 km and 85% of larvae traveled 150 km). The question is, when during larval development, and where on the shallow SW Florida shelf, does the tidal response become incorporated into the behavior of pink shrimp

PET-CT: Head and Neck Tumors. Picture essay and literature review

La PET-CT como modalidad diagnóstica es muy útil en la evaluación anatomofisiológica de la cabeza y el cuello. Proporciona una alta sensibilidad y especificidad en la estadificación de neoplasias primarias, la respuesta al tratamiento médico o quirúrgico y la detección de recurrencias. Dichas enfermedades representan un alto impacto sobre la mortalidad y morbilidad de los pacientes. El principal objetivo de esta publicación es hacer una revisión de los hallazgos en la PET-CT de los tumores más frecuentes de cabeza y cuello, con énfasis en los procesos malignos, estudiados en nuestra institución.PET-CT as a diagnostic modality which is very useful in the anatomical-physiological assessment of the head and neck. It provides high sensitivity and specificity in the staging of primary tumors, the response to medical or surgical treatment and the detection of recurrences. These diseases represent a high impact on the mortality and morbidity in our patients. Our main objective is to review the findings on PET-CT of the most common head and neck tumors with an emphasis on malignancy which are studied in our institution

Temperature effects on zoeal morphometric traits and intraspecific variability in the hairy crab Cancer setosus across latitude

International audiencePhenotypic plasticity is an important but often ignored ability that enables organisms, within species-specific physiological limits, to respond to gradual or sudden extrinsic changes in their environment. In the marine realm, the early ontogeny of decapod crustaceans is among the best known examples to demonstrate a temperature-dependent phenotypic response. Here, we present morphometric results of larvae of the hairy crab , the embryonic development of which took place at different temperatures at two different sites (Antofagasta, 23°45′ S; Puerto Montt, 41°44′ S) along the Chilean Coast. Zoea I larvae from Puerto Montt were significantly larger than those from Antofagasta, when considering embryonic development at the same temperature. Larvae from Puerto Montt reared at 12 and 16°C did not differ morphometrically, but sizes of larvae from Antofagasta kept at 16 and 20°C did, being larger at the colder temperature. Zoea II larvae reared in Antofagasta at three temperatures (16, 20, and 24°C) showed the same pattern, with larger larvae at colder temperatures. Furthermore, larvae reared at 24°C, showed deformations, suggesting that 24°C, which coincides with temperatures found during strong EL Niño events, is indicative of the upper larval thermal tolerance limit.   is exposed to a wide temperature range across its distribution range of about 40° of latitude. Phenotypic plasticity in larval offspring does furthermore enable this species to locally respond to the inter-decadal warming induced by El Niño. Morphological plasticity in this species does support previously reported energetic trade-offs with temperature throughout early ontogeny of this species, indicating that plasticity may be a key to a species' success to occupy a wide distribution range and/or to thrive under highly variable habitat conditions

O final dos reinos: Diálogos entre Tiwanaku e La Aguada

Este escrito pone de nuevo a dialogar las iconografías de Tiwanaku (altiplano del Titicaca, Bolivia) y La Aguada (Noroeste de la Argentina), a más de 40 años de los trabajos de Rex González y de Ponce Sanginés. Lo hace en un contexto enteramente diferente con un énfasis decolonial. Objetos, imágenes, información etnográfica y arqueólogos de ambos lados de una frontera entre "naciones", se ensamblan con la clara intención de cuestionar supuestos subyacentes muy profundos de la arqueología. Metodología: a partir de los caminos que plantean las imágenes y colores, se amarran en estos nudos también los humanos y las cosas, las experiencias chamánicas y los fenómenos meteorológicos, todos enlazados de modo relacional. Conclusiones: tras poner a dialogar a La Aguada y Tiwanaku, con base en nuestras trayectorias investigativas, la discusión desemboca en una reflexión acerca de las consecuencias presentes de naturalizar miradas segmentadas y funcionalistas de los mundos animales y vegetales en el pasado, que se originan en los subyacentes ontológicos de nuestra propia modernidad. Originalidad: el texto apunta a abordar la crítica decolonial a partir del estudio de casos concretos y a aportar a esos debates desde materialidades arqueológicas.This paper once again brings the iconographies of Tiwanaku (Titicaca high plateau, Bolivia) and La Aguada (Northwest of Argentina) into discussion, more than 40 years after the works of Rex González and Ponce Sanginés. It does so in an entirely different context with a decolonial emphasis. Objects, images, ethnographic information and archaeologists from both sides of a border between “nations” are assembled with the clear intention of questioning very deep underlying assumptions of archaeology. Methodology: Beginning with the paths posed by images and colors, these knots also bind humans and things, shamanic experiences and meteorological phenomena. Conclusions: After bringing La Aguada and Tiwanaku into dialogue, based on our research trajectories, the discussion leads to a reflection on the present consequences of naturalizing segmented and functionalist gazes of the animal and plant worlds in the past, which originate in the ontological underpinnings of our own modernity. Originality: The text aims to approach decolonial criticism from the study of concrete cases and to contribute to these debates on the basis of archaeological materiality.Fil: Marconetto, María Bernarda. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Antropología de Córdoba. Universidad Nacional de Córdoba. Facultad de Filosofía y Humanidades. Instituto de Antropología de Córdoba; ArgentinaFil: Villanueva Criales, Juan Eduardo. Museo Nacional de Etnografía y Folklore; Bolivi