Disruptions in International Trade: A Perspective on Ports of Entry and Supply Chain Resilience

United States (U.S.) ports of entry (POEs) and supply chains (SCs) have a prominent trade relationship with a growing desire to improve their operational capabilities. Though trade deals like the U.S.-Mexico-Canada (USMCA) agreement have facilitated trade between these countries, U.S. Customs and Border Protection (CBP) at POEs have also increased security inspections, following the September 11th incident, which have impacted international and global SCs. More recently, the COVID-19 pandemic has caused labor shortages at both sea and land POEs, increasing vessel and commercial vehicle congestion. These POE disruptions have also propagated into the third-party logistics (3PL) of SC networks, which has increased transportation costs. In this thesis, we explored operational improvement strategies from the perspectives of the public sector (i.e., U.S.-Mexico POEs) and the private sector (i.e., 3PL SC networks). The goal of this study was to understand the relationship between transportation disruptions and international trade

El Proyecto fin de carrera como medio conductor para la iniciación a la investigación

Los proyectos fin de carrera son una herramienta útil para la atracción de estudiantes hacia las líneas de investigación de los distintos profesores. En base a la experiencia de los autores como profesores este artículo pretende presentar algunos de los principales errores que se comenten cuando se pretende utilizar los proyectos fin de carrera como mecanismo para introducir a los alumnos en el mundo de la investigación. De la misma manera se presentan algunas pautas para evitar caer en dichos errores.Peer Reviewe

Event-triggered attitude control for flying robots using an event approach based on the control

International audienceThis paper presents the development of a quaternion-based nonlinear event-triggered control for the attitude stabilization of Flying robots. Firstly, it is proved the existence of a Control Lyapunov Function. Unlike some previously proposed schemes, the aim of this paper is to propose a new and simpler event function. The control law ensures the asymptotic stability of the closed-loop system to the desired attitude. The approach is validated in real-time using a quadrotor mini-helicopter. The experiments show that the event driven controller reduces the control update without deteriorating the closed-loop system performance

Stray Flux Sensors Core Impact on the Condition Monitoring of Electrical Machines

The analysis of the stray flux for electrical machine condition monitoring is a very modern and active research topic. Thanks to this technique, it is possible to detect several types of failures, including stator and rotor inter-turn faults, broken rotor bars and mechanical faults, among others. The main advantages are that it involves a non-invasive technique and low-cost monitoring equipment. The standard practice is to use coreless flux sensors, with which the stray flux of the machine is not perturbed and there are no problems due to saturation or nonlinear behavior of the iron. However, the induced voltage in the coreless coil sensor may be very low and even, in some cases, have a similar amplitude to the noise floor. This paper studies the use of iron core stray flux sensors for condition monitoring of electrical machines. The main advantage of iron core flux sensors is that the measured electromotive force is stronger. In the case of large machines in noisy environments, this can be crucial. Two different types of iron core stray flux sensors and a coreless flux sensor are tested. A comparison of the three sensors is presented. Extensive experimental testing with all sensors shows the superiority and greater sensitivity of sensors with core versus the coreless ones

Event-triggered attitude control for flying robots using an event approach based on the control

International audienceThis paper presents the development of a quaternion-based nonlinear event-triggered control for the attitude stabilization of Flying robots. Firstly, it is proved the existence of a Control Lyapunov Function. Unlike some previously proposed schemes, the aim of this paper is to propose a new and simpler event function. The control law ensures the asymptotic stability of the closed-loop system to the desired attitude. The approach is validated in real-time using a quadrotor mini-helicopter. The experiments show that the event driven controller reduces the control update without deteriorating the closed-loop system performance

GoogleWave: Una herramienta para la evaluación de trabajos realizados fuera del aula

La evaluación de los trabajos en grupo es siempre difícil para el profesorado porque éste desconoce la cantidad de esfuerzo que ha dedicado cada alumno al trabajo asignado. Este artículo pretende presentar la herramienta Google Wave1 como una herramienta capaz de aportar una serie de funcionalidades no aportadas anteriormente por ninguna otra herramienta que facilitan al profesorado la evaluación del esfuerzo de cada alumno durante la realización de un trabajo en grupo.Peer Reviewe

Integration of Solid-State Nanopores in Microfluidic Networks via Transfer Printing of Suspended Membranes

Solid-state nanopores have emerged as versatile single-molecule sensors for applications including DNA sequencing, protein unfolding, micro-RNA detection, label-free detection of single nucleotide polymorphisms, and mapping of DNA-binding proteins involved in homologous recombination. While machining nanopores in dielectric membranes provides nanometer-scale precision, the rigid silicon support for the membrane contributes capacitive noise and limits integration with microfluidic networks for sample preprocessing. Herein, we demonstrate a technique to directly transfer solid-state nanopores machined in dielectric membranes from a silicon support into a microfluidic network. The resulting microfluidic-addressable nanopores can sense single DNA molecules at high bandwidths and with low noise, owing to significant reductions in membrane capacitance. This strategy will enable large-scale integration of solid-state nanopores with microfluidic upstream and downstream processing and permit new functions with nanopores such as complex manipulations for multidimensional analysis and parallel sensing in two and three-dimensional architectures.National Institutes of Health (U.S.) (Grant R21EB009180)United States. Air Force (Contract FA8721-05-C-0002

Cork Core Sandwich Plates for Blast Protection

This article belongs to the Special Issue Armour and Protection SystemsA numerical model is developed and validated to analyse the performance of aluminium skin and agglomerated cork core sandwich plates subjected to blast loads. Two numerical approaches are used and thoroughly compared to generate the blast loading: an Arbitrary-Lagrangian–Eulerian approach and the Load Blast Enhanced method. Both of the models are validated by comparing the numerical results with experimental observations. A detailed analysis of the sandwich behaviour is done for both approaches showing small differences regarding the mechanical response of the sandwich structure. The results obtained from the numerical models uncover the specific energy absorption mechanisms happening within the sandwich plate components. A new core topology is proposed, based on these results, which maximises the energy absorption capacity of the plate, keeping the areal density unchanged. A wavy agglomerated cork core is proposed and the effects of different geometrical parameters on the energy absorption are thoroughly analysed and discussed. The proposed optimised plate configuration shows an increase in the total absorbed energy of close to 40% relative to a reference case with the same areal density. The adopted optimisation methodology can be applied to alternative configurations to increase the performance of sandwich structures under blast events.This research was funded by Ministerio de Economía y Competitividad, Gobierno de España grant number DPI2017-85073-R, and Universidad Carlos III of Madrid grant numbers 2013/00413/003 and 2014/00006/002. And the travel expenses were funded by Universidad Carlos III de Madrid grant number Programa propio de investigación-Convocatoria 2014 movilidad

Willingness to pay for improved irrigation water supply reliability: an approach based on probability density functions

In irrigated agricultural systems, a major source of uncertainty relates to water supply, as it significantly affects farm income. This paper investigates farmers’ utility changes associated with shifts in the probability density function of water supply leading to a higher water supply reliability (higher mean and lower variance in annual water allotments). A choice experiment relying on a mean-variance approach is applied to the case study of an irrigation district of the Guadalquivir River Basin (southern Spain). To our knowledge, this is the first study using parameters of these probability density functions of water supply as choice experiment attributes to value water supply reliability. Results show that there are different types of farmers according to their willingness to pay (WTP) for improvements in water supply reliability, with some willing to pay nothing (47.8%) while others have a relatively low (28.0%) or high (24.2%) WTP. A range of factors influencing farmers’ preferences toward water supply reliability are revealed, with those related to risk exposure to water availability being of special importance. The results can be used to assist the design of more efficient policy instruments to improve water supply reliability in Mediterranean and semi-arid climate region

Alginate nanofibers with tunable biodegradability for regenerative medicine [Abstract]

Alginate nanofibers with tunable biodegradability for regenerative medicine [Abstract