6,809 research outputs found
Common agenda or Europe's agenda? International protection, human rights and migration from the Horn of Africa
This paper examines the relationship between international protection, human rights and migration in the context of EU Agenda on Migration which aims to ‘tackle migration upstream’ and reduce the number of arrivals to Europe from countries in the Horn of Africa (HoA) (Eritrea, Somalia, Ethiopia, South Sudan and Sudan). These initiatives are underpinned by assumptions about the factors driving migration from the region, including the idea that poverty rather than political oppression and human rights abuse is the principal cause. The paper draws on interview and survey data with 128 people originating from HoA countries and arriving in Europe between March 2011 and October 2016 to show that conflict, insecurity and human rights abuse in countries of origin and neighbouring countries drive decisions to move. This evidence challenges the premises underlying the European Agenda. Moreover, a lack of coherence between the EU’s ambitions to control irregular migration and the rights-violating States with which Europe seeks to engage threatens to create further political destabilisation which may ultimately increase, rather than decrease, outward migration from the region. Agreements between the EU and HoA should be re-centred to focus on compliance with international human rights standards rather than States’ willingness and to prevent irregular migration to Europe
The middeck 0-gravity dynamics experiment
The Middeck 0-Gravity Dynamics Experiment (MODE), flown onboard the Shuttle STS-48 Mission, consists of three major elements: the Experiment Support Module, a dynamics test bed providing computer experiment control, analog signal conditioning, power conditioning, an operator interface consisting of a keypad and display, experiment electrical and thermal control, and archival data storage: the Fluid Test Article assembly, used to investigate the dynamics of fluid-structure interaction in 0-gravity; and the Structural Test Article for investigating the open-loop dynamics of structures in 0-gravity. Deployable, erectable, and rotary modules were assembled to form three one- and two-dimensional structures, in which variations in bracing wire and rotary joint preload could be introduced. Change in linear modal parameters as well as the change in nonlinear nature of the response is examined. Trends in modal parameters are presented as a function of force amplitude, joint preload, and ambient gravity. An experimental study of the lateral slosh behavior of contained fluids is also presented. A comparison of the measured earth and space results identifies and highlights the effects of gravity on the linear and nonlinear slosh behavior of these fluids
Contrasting the capabilities of building energy performance simulation programs
For the past 50 years, a wide variety of building energy simulation programs have been developed, enhanced and are in use throughout the building energy community. This paper is an overview of a report, which provides up-to-date comparison of the features and capabilities of twenty major building energy simulation programs. The comparison is based on information provided by the program developers in the following categories: general modeling features; zone loads; building envelope and daylighting and solar; infiltration, ventilation and multizone airflow; renewable energy systems; electrical systems and equipment; HVAC systems; HVAC equipment; environmental emissions; economic evaluation; climate data availability, results reporting; validation; and user interface, links to other programs, and availability
Modeling and optimization of production and distribution of drinking water at VMW
We develop and discuss an operational planning model aiming at minimizing production and distribution costs in large drinking water networks containing buffers with free inflow. Modeling drinking water networks is very challenging due of the presence of complex hydraulic constraints, such as friction losses and pump curves. Non-linear, non-convex constraints result from the relationships between pressure and flow in power terms. Also, binary variables are needed to model the possibility of free inflow or re-injection of water at reservoirs. The resulting model is thus a non-convex Mixed-Integer Non-Linear Program (MINLP). A discrete-time setting is proposed to solve the problem over a finite horizon made of several intervals. A commercial solver, BONMIN, suited for convex MINLP models is used to heuristically solve the problem. We are able to find a good solution for a small part of an existing network operated by the Vlaamse Maatschappij voor Watervoorziening (VMW), a major drinking water company in Flanders
An experimental and computational analysis of buoyancy driven flows by laser sheet tomography, particle image velocimetry and computational fluid dynamics
This paper contains details of a three pronged investigation into the development of a buoyant jet impinging on a wall in a closed vessel. The development of the flow was measured experimentally by particle image velocimetry (PIV) and laser sheet tomography. The experimental results are compared with a computational model of the flow calculated by the computational fluid dynamics (CFD) package PHOENICS
The politics of evidence-based policy in Europe’s ‘migration crisis’
Significant increases in the number of refugees and other migrants arriving across the Mediterranean to Europe during 2015 were associated with an increased emphasis on gathering research evidence to enable policymakers to better understand the complexities of migration and improve the policy response. In the UK, the emphasis on evidence-based policy was reflected in funding by the Economic and Social Research Council for a Mediterranean Migration Research Programme. Drawing on the evidence gathered through this programme, the articles in the volume explore the nature of Europe’s ‘migration crisis’ and the extent to which the development of new migration management policies was grounded in evidence about the causes, drivers and consequences of migration to Europe. The authors conclude that there is a substantial ‘gap’ between the now significant body of evidence examining migration processes and European Union policy responses. This gap can be attributed to three main factors: the long-standing ‘paradigm war’ in social research between positivist, interpretivist and critical approaches which means that what counts as ‘evidence’ is contested; competing knowledge claims associated with research and other forms of evidence including the management data to construct and/or support particular policy narratives; and, perhaps most importantly, the political context within which migration policymaking takes place. The politics of policymaking, perhaps nowhere more evident than in the area of migration, has resulted in policies based on underlying assumptions and vested political interests rather than the evidence, even where this evidence has been funded directly by European governments
Noncommutative resolutions of ADE fibered Calabi-Yau threefolds
In this paper we construct noncommutative resolutions of a certain class of Calabi-Yau threefolds studied by F. Cachazo, S. Katz and C. Vafa. The threefolds under consideration are fibered over a complex plane with the fibers being deformed Kleinian singularities. The construction is in terms of a noncommutative algebra introduced by V. Ginzburg, which we call the "N=1 ADE quiver algebra"
The Middeck Active Control Experiment (MACE)
The Middeck Active Control Experiment (MACE) is a NASA In-Step and Control Structure Interaction (CSI) Office funded Shuttle middeck experiment. The objective is to investigate the extent to which closed-loop behavior of flexible spacecraft in zero-gravity (0-g) can be predicted. This prediction becomes particularly difficult when dynamic behavior during ground testing exhibits extensive suspension and direct gravity coupling. On-orbit system identification and control reconfiguration is investigated to improve performance which would otherwise be limited due to errors in prediction. The program is presently in its preliminary design phase with launch expected in the summer of 1994. The MACE test article consists of three attitude control torque wheels, a two axis gimballing payload, inertial sensors and a flexible support structure. With the acquisition of a second payload, this will represent a multiple payload platform with significant structural flexibility. This paper presents on-going work in the areas of modelling and control of the MACE test article in the zero and one-gravity environments. Finite element models, which include suspension and gravity effects, and measurement models, derived from experimental data, are used as the basis for Linear Quadratic Gaussian controller designs. Finite element based controllers are analytically used to study the differences in closed-loop performance as the test article transitions between the 0-g and 1-g environments. Measurement based controllers are experimentally applied to the MACE test article in the 1-g environment and achieve over an order of magnitude improvement in payload pointing accuracy when disturbed by a broadband torque disturbance. The various aspects of the flight portion of the experiment are also discussed
Conserved Genome Organization and Core Transcriptome of the Lactobacillus acidophilus Complex
The Lactobacillus genus encompasses a genetically and functionally diverse group of species, and contains many strains widely formulated in the human food supply chain as probiotics and starter cultures. Within this genetically expansive group, there are several distinct clades that have high levels of homology, one of which is the Lactobacillus acidophilus group. Of the uniting features, small genomes, low GC content, adaptation to dairy environments, and fastidious growth requirements, are some of the most defining characteristics of this group. To better understand what truly links and defines this clade, we sought to characterize the genomic organization and content of the genomes of several members of this group. Through core genome analysis we explored the synteny and intrinsic genetic underpinnings of the L. acidophilus clade, and observed key features related to the evolution and adaptation of these organisms. While genetic content is able to provide a large map of the potential of each organism, it does not always reflect their functionality. Through transcriptomic data we inferred the core transcriptome of the L. acidophilus complex to better define the true metabolic capabilities that unite this clade. Using this approach we have identified seven small ORFs that are both highly conserved and transcribed in diverse members of this clade and could be potential novel small peptide or untranslated RNA regulators. Overall, our results reveal the core features of the L. acidophilus complex and open new avenues for the enhancement and formulation and of next generation probiotics and starter cultures
- …