Multiple Steady States in Homogeneous Azeotropic Distillation

In this article we study multiple steady states in ternary homogeneous azeotropic distillation. We show that in the case of infinite reflux and an infinite number of trays one can construct bifurcation diagrams on physical grounds with the distillate flow as the bifurcation parameter. Multiple steady states exist when the distillate flow varies non-monotonically along the continuation path of the bifurcation diagram. We derive a necessary and sufficient condition for the existence of these multiple steady states based on the geometry of the distillation region boundaries. We also locate in the composition triangle the feed compositions that lead to these multiple steady states. We further note that most of these results are independent of the thermodynamic model used. We show that the prediction of the existence of multiple steady states in the case of infinite reflux and an infinite number of trays has relevant implications for columns operating at finite reflux and with a finite number of trays. Using numerically constructed bifurcation diagrams for specific examples, we show that these multiplicities tend to vanish for small columns and/or for low reflux flows. Finally, we comment on the effect of multiplicities on column design and operation for some specific examples

Control of 2 × 2 Linear Hyperbolic Systems: Backstepping-Based Trajectory Generation and PI-Based Tracking

International audience— We consider the problems of trajectory generation and tracking for general 2 × 2 systems of first-order linear hyperbolic PDEs with anti-collocated boundary input and output. We solve the trajectory generation problem via backstepping. The reference input, which generates the desired output, incorporates integral operators acting on advanced and delayed versions of the reference output with kernels which were derived by Vazquez, Krstic, and Coron for the backstepping stabilization of 2×2 linear hyperbolic systems. For tracking the desired trajectory we employ a PI control law on the tracking error of the output. We prove exponential stability of the closed-loop system, under the proposed PI control law, when the parameters of the plant and the controller satisfy certain conditions, by constructing a novel " non-diagonal " Lyapunov functional

Навыки и требования к обучению с целью обеспечения будущего транспортного сектора Европы

More than 10 million people are directly employed by the transport industry in Europe, accounting for 4.5 % of total employment and representing 4.6 % of Gross Domestic Product (GDP). This fact, combined with the rapid developments and changes of the sector, makes imperative the need to create, attract and retain appropriate staff. As the overall trend is to increase automation, the sector will depend more and more on specialised equipment and products. Future jobs will therefore require new and advanced skills in engineering as well as in back office operations, but at the same time, the growing interdisciplinary elements of transport activities will also require transport professionals with developed skills in safety, security, logistics, IT, behavioural sciences, marketing and economics. The European Research project SKILLFUL has developed a structured foresight into the vocational and academic qualifications in the Transportation sector of the future and has proposed training schemes and their supportive business models that could ideally be adopted European-wide, to enhance employability and sustainable industrial development in the transportation sector in Europe. The identification of future requirements constituted the basis of the project. The impact of new technologies and game changers, as well as emphasis on intermodality and interdisciplinarity on employability and future worker skills, have led to the development of relevant scenarios on future jobs knowledge and skills requirements, regarding the road transport in Europe. This has led to the identification and design of proper and specific curricula for training (with emphasis on middle-skilled professionals and lifelong learning), while also to the introduction of six novel concepts of business actors, expected to facilitate the training process and enhance the transport-education chain. The project goes a step beyond by addressing also critical issues towards a PanEuropean master curriculum on transport.В Европе более 10 миллионов человек заняты непосредственно в транспортной отрасли, что составляет 4,5 % от общей занятости (4,6 % валового внутреннего продукта (ВВП)). Эта статистика в сочетании с быстрым развитием и изменениями в данном секторе экономики предполагает необходимость обучения, привлечения и сохранения квалифицированного персонала. Поскольку общая тенденция заключается в увеличении процесса автоматизации, данное направление экономики будет все больше зависеть от специализированного оборудования и приспособлений. Поэтому на новых рабочих местах потребуются новые квалификации и навыки, передовые технологии в осуществлении инженерно-технических работ, а также в ведении технической документации; в то же время усиление роли междисциплинарных элементов транспортной деятельности также потребует привлечения профессионалов в области транспорта, обладающих высоким уровнем знаний и навыков в сфере безопасности, охраны, логистики, информационных технологий, бихевиористики, маркетинга и экономики. В рамках реализации Европейского научно-исследовательского проекта SKILLFUL был выработан структурированный прогноз будущих профессиональных и академических квалификаций в секторе транспорта, а также предложены схемы обучения и поддерживающие их бизнес-модели, которые идеально подходят и могут быть приняты в масштабе всей Европы. Это должно повысить возможности трудоустройства и обеспечить устойчивое развитие транспортного сектора в Европе. Определение новых требований и легло в основу данного проекта. Влияние новых технологий и наличие решающих факторов, которые кардинально меняют ситуацию в сфере транспорта, выдвижение в категорию приоритетных интермодальности и междисциплинарности в вопросах трудоустройства и развития в будущем новых навыков привели к разработке соответствующих сценариев с целью формирования новых знаний и навыков для новых рабочих мест в сфере автомобильного транспорта в Европе. В связи с этим определены и разработаны надлежащие специальные учебные программы (особое внимание уделено подготовке специалистов среднего звена, вопросам организации образования через всю жизнь), а также внедрению шести новых концепций бизнес-акторов, что должно способствовать организации учебного процесса и продвижению транспортно-образовательной сети. Рассматриваемый проект выходит за рамки своих специфических задач, решая при этом и важнейшие вопросы, которые связаны с общеевропейской основной учебной программой по транспорту

WALLABY Early Science - I. The NGC 7162 Galaxy Group

We present Widefield ASKAP L-band Legacy All-sky Blind Survey (WALLABY) early science results from the Australian Square Kilometre Array Pathfinder (ASKAP) observations of the NGC 7162 galaxy group. We use archival HIPASS and Australia Telescope Compact Array (ATCA) observations of this group to validate the new ASKAP data and the data reduction pipeline ASKAPsoft. We detect six galaxies in the neutral hydrogen (HI) 21-cm line, expanding the NGC 7162 group membership from four to seven galaxies. Two of the new detections are also the first HI detections of the dwarf galaxies, AM 2159-434 and GALEXASC J220338.65-431128.7, for which we have measured velocities of $cz=2558$ and $cz=2727$ km s$^{-1}$, respectively. We confirm that there is extended HI emission around NGC 7162 possibly due to past interactions in the group as indicated by the $40^{\circ}$ offset between the kinematic and morphological major axes for NGC 7162A, and its HI richness. Taking advantage of the increased resolution (factor of $\sim1.5$) of the ASKAP data over archival ATCA observations, we fit a tilted ring model and use envelope tracing to determine the galaxies' rotation curves. Using these we estimate the dynamical masses and find, as expected, high dark matter fractions of $f_{\mathrm{DM}}\sim0.81-0.95$ for all group members. The ASKAP data are publicly available.Comment: 20 pages, 11 figures, accepted for publication in MNRA