A systematic revision of the South American freshwater stingrays (chondrichthyes: potamotrygonidae) (batoidei, myliobatiformes, phylogeny, biogeography)

Three genera are recognized in the family Potamotrygonidae of neotropical freshwater stingrays: Potamotrygon, Paratrygon, and Plesiotrygon, the latter being described as a new genus. Potamotrygon is polytypic, and both Paratrygon and Plesiotrygon are monotypic, as far as known. The family name Potamotrygonidae has priority over Paratrygonidae Gill. Nineteen previously described species of Potamotrygonidae are recognized: Paratrygon aiereba, Potamotrygon brachyura, P. castexi, P. constellata, P. dumerilii, P. falkneri, P. henlei, P. histrix, P. humerosa, P. leopoldi, P. magdalenae, P. motoro, P. ocellata, P. orbignyi, P. schroederi, P. schuemacheri, P. scobina, P. signata, and P. yepezi. One additional specific name is established as new (Plesiotrygon iwamae). Three of the eighteen recognized species of Potamotrygon are resurrected from synonymy (P. dumerilii, P. henlei, and P. orbignyi), one previously overlooked subspecific name (Trygon histrix ocellata) is erected to specific rank, and one previously overlooked specific name (Taeniura constellata) is placed in the genus Potamotrygon, and treated as a senior synonym of P. circularis. The remaining names previously assigned to the Potamotrygonidae include: eight junior synonyms (Disceus thayeri, Potamotrygon brumi, P. circularis, P. laticeps, P. menchacai, Trygon mulleri, T. reticulatus, and T. strogylopterus), five doubtful names (Elipesurus spinicauda, Potamotrygon africana, P. alba, P. humboldtii, and Trygon garrapa), two invalid names (Potamotrygon labratoris and P. pauckei), two doubtful names corresponding to one unidentified marine species of the family Dasyatididae (Raja ajereba and R. orbicularis), and one freshwater species of Dasyatis (D. garouaensis) originally described in the genus Potamotrygon. Potamotrygon and Paratrygon are regarded as sister groups, and Plesiotrygon as the primitive potamotrygonid genus, based on a cladistic analysis of stingray characters. Plesiotrygon is restricted to the upper Amazon drainage, and Paratrygon is known from most of the Amazon drainage, occurring also in Rio Orinoco. Eleven species of Potamotrygon have Amazonian distribution (including Rio Tocantins), four of which occur also in other drainages. Four species of Potamotrygon are apparently endemic to Rio Paraguay and lower Rio Parana drainages (P. brachyura, P. falkneri, P. histrix, and P. schuemacheri); P. yepezi is endemic to the Maracaibo basin in Venezuela; P. magdalenae is endemic to Rio Magdalena and Rio Atrato drainages in Colombia, and P. signata is apparently endemic to Rio Parna(\u27)iba drainage in Brazil

First applications of the Orbex coprocessor: control of unmanned vehicles

The ORBEX coprocessor has been designed to execute the typical fuzzy operations of a system based on fuzzy rules. The first real application has been fuzzy controllers for electric cars. The values of the input variables, the position and the orientation of the car with respect the desired trajectory of reference, are obtained from the data provided by a DGPS boarded in the vehicle. The values of the output variables provided by the controller are the angle that the steering wheel has to be turned and the increment of the velocity. Due to the power of the ORBEX coprocessor the controllers can be written with few though meaningful rules

Plano estratégico para a requalificação dos Olivais-Sul utilizando as Nature-based solutions

Mestrado em Arquitectura Paisagista - Instituto Superior de Agronomia - ULCom a migração de população para as áreas urbanas que se avizinha nos próximos anos, as formas de planeamento que tenham em conta uma existência equilibrada entre o Homem e os ecossistemas são cada vez mais importantes. Os conceitos aplicados na construção das cidades são gradualmente mais focados na sustentabilidade da paisagem. Procura-se estudar o desenvolvimento histórico da urbanização dos Olivais-Sul, compreendendo a sua evolução ao longo do tempo, bem como os principais fatores e elementos da construção desta paisagem. Parte desta investigação é feita sobre a presença destes elementos no espaço urbano bem como o seu papel no funcionamento urbano. O estudo apura se os Olivais-Sul com uma grande presença de espaços verdes desenhados no modernismo são verdadeiramente sustentáveis, identifica os tipos de problemas existentes e os métodos de requalificação disponíveis. O conceito das nature-based solutions é abordado para aplicar mais tarde num plano que requalifique os Olivais tornando-o uma paisagem mais sustentável. Investigou-se sobre a consistência do conceito um ponto preponderante por ser novo, para tal a documentação científica existente sobre o tema foi estudada e foram analisados os prós e contras do conceito. Referem-se também vários casos estudo para perceber as áreas de aplicabilidade do tema e analisar a resolução desafios que muitas recorrem a soluções bastante flexíveis e cuja finalidade trabalha vários tópicos. A base teórica e histórica estudada nos primeiros capítulos é utilizada para aplicar no desenvolvimento do plano estratégico de requalificação dos Olivais-Sul cuja finalidade é adaptar esta paisagem às alterações climáticas, contribuindo ecologicamente para uma paisagem resiliente e sustentável, contudo existe também a componente cultural dos Olivais em que se observa a ausência da utilização do espaço público e a escassa integração de património de estruturas históricas importante, como as Quintas, que pretende-se reintegrar no espaço públicoN/

Respuesta productiva y rendimiento de carcasa de llamas (Lama glama) dientes de leche sometidas a engorde, cuatro tipos de alimentación

Universidad Nacional Agraria La Molina. Escuela de Posgrado. Maestría en NutriciónEl presente trabajo se realizó en la Comunidad Campesina San Pedro de Ninacaca-Pasco con el objetivo de evaluar la respuesta productiva de llamas machos diente de leche sometidas a engorde con cuatro tipos de alimentación (T1: Pastura natural; T2: T1 + dosificación vitamínica; T3: T1 + heno de alfalfa; T4: T2 + heno de alfalfa). Se utilizó un diseño completamente al azar con arreglo factorial de 2 x 2 (dos suplementaciones; y dos dosificaciones vitamínicas) con co-varianza (considerando al peso vivo inicial como co-variable). Se emplearon 32 llamas machos diente de leche (genotipo heterogéneo), y el engorde tuvo una duración de 84 días. La carga animal empleada fue de 1.3 unidades llama/ha. La ganancia diaria de peso (GDP) se evaluó en los periodos de engorde a: 0, 14, 28, 42, 56, 70 y 84 días. Al evaluar la GDP por periodo de engorde se hallaron diferencias altamente significativas entre periodos. Siendo los primeros tres periodos (14, 28 y 42 días) que mostraron mejor GDP (337, 237 y 160 g/d, respectivamente). Al evaluar la GDP por tipo de alimentación se observó mayor GDP (p<0.01) con el T3 (157 g/d) que en T1 (106 g/d). El mejor rendimiento de carcasa se obtuvo con el T4 (53.60%) seguido por el T3 (53.20%). Se concluye que la mayor GDP se logra hasta los 42 días y el mejor rendimiento de carcasa se logra en la pastura natural + suplementación con heno de alfalfa (T3).The aim of the present study was to evaluate the productive response of male llamas, milk teeth, under a four-treatment feeding trial as it follows: T1: natural pasture; T2: T1 + vitamins; T3: T1 + alfalfa hay and T4: T2 + alfalfa hay, in a completely randomized design, 2x2 factorial arrangement (2 supplementations and 2 vitamin dosages) and covariance (initial weight as covariate). Thirty two male llamas (heterogeneous genotype) were fed the experimental diets for 84 days. The carrying capacity was 1.3 llama/ha. Daily weight gain (DWG) was measured at day 0, 14, 28, 42, 56, 70 and 84. The highest values for DWG (337, 237 and 160 g/d) were found at day 14, 28 and 42, respectively. In regard to the treatments, the highest value for DWG was found with treatment 4 (157 g/d) and the highest meat yield with treatment 4 and 3 (53.6 and 53.2%, respectively). In conclusion, the highest DWG can be obtained at day 42 and the best meat yield with a natural pasture supplemented with alfalfa hay.Tesi

Dispositivo y procedimiento útil para el control de un automóvil, con ayuda de GPS y comunicaciones inalámbricas, que permite efectuar adelantamientos

Dispositivo y procedimiento útil para el control de un automóvil, con ayuda de GPS y comunicaciones inalámbricas, que permite efectuar adelantamientos. El dispositivo y procedimiento permite el control automático para realizar mediante un computador maniobras de adelantamiento en carretera, manejando los tres actuadores principales del vehículo, acelerador, freno y dirección sin intervención humana, basándose en información sensorial proveniente de sistemas GNSS, redes de comunicaciones inalámbricas Wi.Fi y la información de navegación del propio vehículo. La computación de control del sistema esta basada en algoritmos de lógica borrosa desarrollados por los autores.Peer reviewedConsejo Superior de Investigaciones Científicas (España)A1 Solicitud de patentes con informe sobre el estado de la técnic

Impact of injection settings operating with the gasoline Partially Premixed Combustion concept in a 2-stroke HSDI compression ignition engine

[EN] Partially Premixed Combustion (PPC) using gasoline-like fuels has proven its potential to control or even break the NOx and soot emissions trade-off, retaining the high efficiency levels characteristic of the conventional diesel combustion (CDC) concept. However, selecting an appropriate fuel and a suitable injection strategy is essential to assure a successful PPC operation in the full engine map. Additionally, extending the limit of PPC beyond 10 bar IMEP was not possible due to excessively high pressure gradients and onset of knocking-like combustion, so the CDC concept has to be adopted and the conventional trade-off between NOx and soot emissions was recovered. Present investigation focuses on evaluating the use of a multiple injection strategy for extending the load range of the PPC concept to medium/high load conditions, when using a commercial RON95 gasoline in a 2-stroke engine under development. Experimental results confirm how with a fine tuned triple injection strategy it is possible to reach extremely low NOx and soot levels keeping combustion efficiency over 96%, while indicated efficiency is improved compared to a well-optimized point obtained operating with the CDC concept. Finally, the research work is completed by including 3D-CFD modeling activities that are carried out to contribute to the understanding on how the mixture preparation and stratification prior to the start of combustion impacts its development and particularly the experimentally observed pollutant emissions trends.This work was partly funded by the Generalitat Valenciana Spain, project PROMETEOII/2014/043. The authors kindly recognize the technical support provided by Mr. Pascal Tribotte from RENAULT SAS - France in the frame of the DREAM-DELTA-68530-13-3205 ProjectBenajes, J.; Novella Rosa, R.; De Lima, D.; Thein, KJL. (2017). Impact of injection settings operating with the gasoline Partially Premixed Combustion concept in a 2-stroke HSDI compression ignition engine. Applied Energy. 193:515-530. https://doi.org/10.1016/j.apenergy.2017.02.044S51553019

ACESSO, RETENÇÃO E EVASÃO: os contornos da exclusão na Universidade Federal de Goiás

Considerando a ampliação das oportunidades educacionais na Universidade Federal de Goiás (UFG), promovida principalmente pelo Programa de Apoio a Planos de Reestruturação e Expansão das Universidades Federais, instituído em 2007, entende-se como relevante relacionar o fenômeno da expansão com o acesso, retenção e evasão na universidade. Portanto, o objetivo deste artigo é compreender os contornos dessas problemáticas na instituição, no período de 2006 a 2016. Para a realização desta pesquisa, em termos de procedimentos técnicos, foram utilizadas as pesquisas documental e bibliográfica. Primeiramente, foi feito um levantamento dos dados documentais de caráter estatístico fornecidos pela Pró-Reitoria de Graduação da UFG sobre os alunos de graduação ingressantes no período investigado. A análise e interpretação desses dados ocorreram com o aporte da pesquisa bibliográfica, baseado em referências teóricas sobre os temas investigados. Como resultado, constatou-se que, a despeito da expansão do número de cursos e vagas, a universidade enfrenta diversos desafios, como: preencher a totalidade de vagas disponibilizadas nos processos seletivos; levar os alunos a concluírem a graduação no período regular, sem ficarem retidos; e minimizar os índices de exclusão, principalmente no primeiro ano do curso.ACCESS, RETENTION AND EVASION:  the contours of exclusion at the Federal University of GoiásAbstract: Considering the expansion of educational opportunities at the Federal University of Goiás, promoted mainly by the Program to Support Restructuring and Expansion Plans of Federal Universities, instituted in 2007, it is understood as relevant to relate the phenomenon of expansion with access, retention and evasion in the university. Therefore, the objective of this article is to understand the contours of these issues in the institution, from 2006 to 2016. For the carrying out of this research, in terms of technical procedures, the documentary and bibliographical researches were used. Firstly, was made a survey of the statistical data provided by the UFG's Graduate Rector's Office about the undergraduate students entering the investigation period was researched. The analysis and interpretation of these data occurred with the contribution of the bibliographic research, based on theoretical references on the subjects investigated. As a result, it was found that, despite the expansion of the number of courses and vacancies, the university faces several challenges, such as: filling all the vacancies made available in the selection processes; to lead students to complete their undergraduate studies in the regular period, without being retained; and minimize exclusion rates, especially in the first year of the course.Keywords: Higher Education. Access. Retention. Evasion. Federal University of Goiás.ACCESO, RETENCIÓN Y EVASIÓN: los contornos de la exclusión en la Universidad Federal de GoiásResumen: Considerando la ampliación de las oportunidades educativas en la Universidad Federal de Goiás, promovida principalmente por el Programa de Apoyo a Planes de Reestructuración y Expansión de las Universidades Federales, instituido en 2007, se entiende como relevante relacionar el fenómeno de la expansión del acceso, retención y evasión en la universidad. Por lo tanto, el objetivo de este artículo es comprender los contornos de esas problemáticas en la institución, en el período de 2006 a 2016. Para la realización de esta investigación, en términos de procedimientos técnicos, se utilizaron las investigaciones documental y bibliográfica. En primer lugar, se hizo un levantamiento de los datos documentales de carácter estadístico proporcionados por la Pro-Rectoría de Graduación de la UFG sobre los alumnos de graduación ingresantes en el período investigado. El análisis e interpretación de estos datos ocurrió con el aporte de la investigación bibliográfica, basado en referencias teóricas sobre los temas investigados. Como resultado, se constató que, a pesar de la expansión del número de cursos y vacantes, la universidad enfrenta diversos desafíos, como: llenar la totalidad de vacantes disponibles en los procesos selectivos; llevar a los alumnos a concluir la graduación en el período regular, sin quedar retenidos; y minimizar los índices de exclusión, principalmente en el primer año del curso.Palabras clave: Educación Superior. Acceso. Retención. Evasión. Universidad Federal de Goiás

Pre-chamber ignition systems: A methodological proposal to reproduce a reference case in a simplified experimental facility for fundamental studies

[EN] To further understand the processes and phenomena taking place in the pre-chamber (PC) ignition concept, many studies under simplified conditions have been carried out in different experimental facilities (e.g. constant volume chambers and rapid compression machines). However limited information is provided about how the volume, orifice diameter and number of orifices were defined, raising the question whether the results are representative of engine-like conditions or not. This novel study arises from the necessity to determine a methodology to reproduce a reference pre-chamber, preserving as much as possible its jet characteristics. A theoretical development based on the first law of thermodynamics has been performed, and a relationship between the effective flow area, pre-chamber volume and engine speed is proposed as the governing parameter of the mass exchange between chambers. Besides, relaying on the know-how of gas jets, a relationship between the orifice diameter, jet tip penetration and engine speed is suggested as the criterion to preserve the relative jet penetration (respect to the distance from the PC hole to the combustion chamber walls). A numerical validation of these assumptions was carried out using a one-dimensional flow calculator to estimate the thermodynamic properties and mass transfer between chambers, and a one-dimensional spray model to estimate the penetration of the PC combustion products jets. Finally, preserving the ratio between the total area of the PC holes and the product of the PC volume and the engine speed for two pre-chamber geometries, an identical pressure rise rate, in an angular basis, is achieved in both pre-chambers. Furthermore, the same relative jet penetration rate, in an angular basis, can be also achieved, even under different engine speeds, when the ratio between the orifice diameter and the product of the square of the jet free length and the engine speed is preserved.The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This research has been partially funded by FEDER and the Spanish Government through project RTI2018-102025-B-I00.Desantes J.M.; López, JJ.; Novella Rosa, R.; Beltrao De Vargas-Antolini, J. (2021). Pre-chamber ignition systems: A methodological proposal to reproduce a reference case in a simplified experimental facility for fundamental studies. International Journal of Engine Research. 22(11):3358-3371. https://doi.org/10.1177/1468087420971115S33583371221