A high order linear model for the prediction of internal lee waves at the main sill of the Strait of Gibraltar

A linear theory for the physical fields in the water column under the action of large amplitude internal lee waves at the main sill of the Strait of Gibraltar is developed. The procedure is a combination of the perturbation and normal modes methods in order to study steady resonant conditions. The lowest order linear approach of the methodology resumes the Taylor–Goldstein equation, which can reconstruct the main features of the observed fields but the high order approach gives the finest structure and sometimes the largest contributions. The role of the non-linear terms is investigated up to the second order taking into account the non-linear interactions between modes, leading to an effective reconstruction of the whole water column for the velocity field.     

Changes in size at maturity of European hake Atlantic populations in relation with stock structure and environmental regimes

European hake (Merluccius merluccius) female size at maturity is estimated on an annual basis for Bay of Biscay and Galician coast, which are parts of the distribution of the Northern and Southern stocks, respectively. Clear trends in this reproductive parameter are observed along the time series and the potential factors affecting these trends have been investigated. Total biomass, different indexes of SSB, age diversity index, fishing mortality at age, NAO winter index, upwelling index and temperature were included in multiple regressions models to assess the relative importance of each of them on shifts in size at maturity.Bay of Biscay and Galician coast hake have followed different evolution in patterns of changes in size at maturity. In Bay of Biscay, a steadily decline of 15 cm has been observed from 1987 to 2004, which is well predicted by fishing mortality and age diversity, but also the environment may have played an important role. However, on the Galician coast a drastic decline of 16 cm from 1980 to 1988 was followed by a rapid increase in size at maturity during the next 10 years to original values and a stable period in the last 6 years. Decreasing biomass may explain the decline in size at maturity in the first period. However, total biomass and spawning biomass declined even during the period when size at maturity increased, which is contrary to compensatory theory. Shifts in environmental regime, NAO and upwelling, may have contributed to a decelerated growth during this period that might explain the later maturation.     

Transferability of sustainable urban mobility measures

This paper describes an approach developed to identify common elements of city performance that have transferability potential across a number of cities. The findings provide a wealth of information sourced from 200 measures in 19 European cities. A transferability framework is proposed, that uses ideas from traditional top-down approaches using city clustering to infer the transferability of measures, as well as elements of a bottom-up approach, based on the concept of “measure enabling context”. Systems' thinking diagramming was used to depict relationships between measures, drivers and barriers, portraying the feedbacks at work and the cause-effect relationships, to establish appealing preconditions for transferability.     

如何分析一场比赛

停维修站时间的选择有什么重要性？一个“燃油校正”的单圈是什么？在下文中，您将了解如何从F1比赛画面里获得更多信息     

Strategies for improving the mode transition in a sequential parallel turbocharged automotive diesel engine

Parallel sequential turbocharging systems are able to operate in different modes, which are defined according to the turbochargers that simultaneously boost the engine, and are controlled by means of specific valves. In order to cover the full engine operating range, a smooth transition between turbocharging operating modes must be ensured. However, important disturbances affect both boost and exhaust pressure when shifting the operation mode, thus causing non-negligible torque oscillations. This paper presents different methods for smoothing such undesirable effects during mode transition. Strategies covering optimal synchronization of the control valves, control of the valves’ position, and correction of the injected fuel during the transition are analysed. A fully instrumented passenger car engine is used for illustrating the different torque smoothing methods, and experimental results for transitions during both steady operation and engine accelerations are shown.     

Are the innovation processes in seaport terminal operations successful?

The maritime and port sector is widely considered conservative concerning the ability to introduce innovation in respect to other industries. This may be due to the lack of cooperative interactions among the several players involved. It does not mean that innovation does not occur in this industry. Along with some technical innovations, managerial, organizational, and cultural innovations also take place in the sector. The literature has considered the assessment and effects of the adoption of particular innovation, but still few studies underline the innovation path in a broad sense with a specific focus on terminal operators. The present article aims at filling this gap through a field analysis grouping together case studies developed in different world regions and examining the adoption path of innovation through a mix of three different techniques (i.e. the H- and I-indexes, a Systems of Innovation Analysis, and a Qualitative Comparative Analysis). Research outcomes underline how, even if no unique recipe for success can be found, specific factors (e.g. a ranking of innovation objectives, coordination among actors, and institutions) can influence the achievement of success. The analyses allow suggesting strategic and policy advice that may help link in a better way the innovation drivers with their actual effects.     

采用智能功率技术的车用暖通空调系统阀门驱动器

本文旨在于简要介绍汽车暖通空调系统的特点，并详细介绍如何使用一个智能功率驱动器控制通风阀的定位。