Perturbation of symmetric 3-RPR manipulators and asymptotic singularities

International audienceSmall perturbations can affect the kinematic properties of manipulators with non-generic architecture. We study in this paper the perturbations of symmetric planar 3-RPR manipulators. We show in particular that one can obtain any of the three possible stable types of behaviour of 3-RPR manipulators for large values of the lengths of the legs

Particular concerns with regard to the Rotterdam Rules

Resumen: A medida que el proceso de fi rma de las Reglas de Rotterdam va tomando cuerpo, también cobran fuerza las voces discordantes. Este artículo o manifi esto recoge la opinión crítica colectiva de un grupo de nueve destacados especialistas en Derecho marítimo de distintas partes del mundo, pertenecientes a los sectores académico y profesional. El artículo analiza con brevedad y precisión los rasgos más destacados de las Reglas de Rotterdam, particularmente aquéllos que, a juicio de los firmantes, meritan mayor debate y crítica. La conclusión a la que llegan los miembros de este grupo de juristas es que las Reglas de Rotterdam no vienen sino a añadir más complejidad a la actual regulación internacional del transporte marítimo y multimodal. El artículo finaliza con una propuesta de alternativas que permitan aprovechar lo mejor de la regulación vigente y abrir las puertas a una actualización y complementación de dicha regulación. Palabras clave: Reglas, Rotterdam, Crítica, Alternativas. Abstract: As the Rotterdam Rules signature process gains momentum, strong dissenting opinions are also starting to be heard. This article or manifesto sums up the collective critical voice of nine worldwide leading shipping lawyers and professors. It provides a short and precise analysis of the Rotterdam Rules main features from the point of view of those issues which the authors fi nd unworthy of praise. And their conclusion is that the Rotterdam Rules simply just add up more complexity to the present shipping and multimodal international regulation. The article closes with a quest for alternatives aimed to get the best of what we already have and opens the gate to proposals based on the updating and complementation of the regulation in force today. Key words: Rules, Rotterdam, Critical, Alternatives

Sensory traits, color, and shelf life of low-dose irradiated, raw, ground beef patties

Irradiation of raw ground beef patties had minimal effects on flavor and aroma of patties after cooking. Oxidative rancidity increased when patties were irradiated in aerobic but not in vacuum packages. Irradiation of vacuum-packaged ground beef patties produced a more stable color. In both packaging types, irradiation significantly reduced microbial growth during storage

Sensory traits, color, and shelf life of low-dose irradiated, precooked, ground beef patties

Irradiation did not influence bitter, bloody, burnt, chemical, fat-like, juiciness, liver-like, beef identity, metallic, rancid, sour, sweet, and toughness flavor/textural attributes, beef aroma, or off-odor in precooked ground beef patties. Irradiation slightly increased the animal hair flavor note, but intensity levels were <1 on the 15-point sensory scale. Except for 10% fat non-irradiated controls, reheated precooked patties had a slight sour, ammonia-like, top note. Irradiation at 3.5 kilograys (kGy) increased external redness in vacuum-packaged patties, but not in aerobic packages. Aerobic packaging with or without irradiation decreased external precooked redness. Oxidative rancidity increased when patties were irradiated in aerobic but not in vacuum packages. Reduction of oxygen in vacuum bags extended the shelf life of the precooked ground beef patties, at least in terms of oxidative rancidity. Precooking ground beef patties, irrespective of irradiation or packaging type, posed sensory disadvantages, and improvements to the precooking process are needed before irradiating at low-dose levels is appropriate

A Blue Print for a Worldwide Multimodal Regime

Resumen: En el nº 2 de 2010 de CDT se publicó un manifiesto del llamado “Grupo de los 9” titulado “Particular concerns with regard to the Rotterdam Rules” en el que estos destacados profesores y juristas expresaban sus dudas acerca de este nuevo instrumento internacional. Este Grupo ofrece ahora un nuevo manifiesto que supone un paso adelante en el que se indica que a pesar de la innegable necesidad de poner al día las Reglas de La Haya-Visby, y de las aportaciones efectuadas en tal sentido por las Reglas de Rótterdam, las perspectivas de éxito de estas últimas se ven ensombrecidas por su pretensión de extenderse más allá de lo que en puridad debía ser su objeto, el transporte marítimo, para convertirse en el texto de referencia para el transporte multimodal que cuente con una fase marítima. Lejos de contribuir a un verdadero y efectivo régimen unificado de la multimodalidad, plantea nuevas dudas a la hora de determinar qué régimen, de entro los existentes para cada tipo de transporte, debe ser de aplicación en cada caso. Mientras tanto, parece que para conseguir los objetivos referidos al transporte marítimo de las Reglas de Rótterdam habría bastado con la introducción de Protocolos a las Reglas de La Haya-Visby, dejando que lo concerniente al transporte multimodal continuara por la senda establecida a tal efecto por el CMR, cuyo sistema quizás debiera traspasar las fronteras europeas con el impulso de las diferentes instituciones internacionales. Palabras clave: Reglas de Rotterdam, transporte multimodal, transporte marítimo, Reglas de La Haya-Visby, CMR.  Abstract: In the issue n. 2 of 2010 of CDT it was published a manifesto of the so-called “Group of the 9” under the title of “Particular concerns with regard to the Rotterdam Rules” where these renowned scholars and attorneys expressed their doubts about this new international legal instrument. The Group offers now a new manifesto providing a step further whereby they indicate that notwithstanding the undeniable necessity to update the Hague-Visby Rules and the contributions carried out in this direction by the Rotterdam Rules, success expectations of the latter rules are hindered because of the aim to expand the scope of application beyond their object in strict sense, namely maritime transport, so as to become the text of reference as for every multimodal transport that includes a sea leg. Far from contributing to a real and effective multimodal unified regime, new doubts arise when determining which regime, of all those for each type of transport, shall apply in each case. In any event, it seems that in order to reach the objectives appointed to by the Rotterdam Rules, introducing Protocols to the Hague-Visby Rules would have been good enough, whereas all that related to multimodal transport continues by the CMR established paths, a system which should trespass European borders with the help of different international institutions. Key words: Rotterdam Rules, multimodal transport, maritime transport, Hague-Visby Rules, CMR

Asymptotic singularities of planar parallel 3-RPR manipulators

We study the limits of singularities of planar parallel 3-RPR manipulators as the lengths of their legs tend to infinity, paying special attention to the presence of cusps. These asymptotic singularities govern the kinematic behavior of the manipulator in a rather large portion of its workspace