The Leeway of Shipping Containers at Different Immersion Levels

The leeway of 20-foot containers in typical distress conditions is established through field experiments in a Norwegian fjord and in open-ocean conditions off the coast of France with wind speed ranging from calm to 14 m/s. The experimental setup is described in detail and certain recommendations given for experiments on objects of this size. The results are compared with the leeway of a scaled-down container before the full set of measured leeway characteristics are compared with a semi-analytical model of immersed containers. Our results are broadly consistent with the semi-analytical model, but the model is found to be sensitive to choice of drag coefficient and makes no estimate of the cross-wind leeway of containers. We extend the results from the semi-analytical immersion model by extrapolating the observed leeway divergence and estimates of the experimental uncertainty to various realistic immersion levels. The sensitivity of these leeway estimates at different immersion levels are tested using a stochastic trajectory model. Search areas are found to be sensitive to the exact immersion levels, the choice of drag coefficient and somewhat less sensitive to the inclusion of leeway divergence. We further compare the search areas thus found with a range of trajectories estimated using the semi-analytical model with only perturbations to the immersion level. We find that the search areas calculated without estimates of crosswind leeway and its uncertainty will grossly underestimate the rate of expansion of the search areas. We recommend that stochastic trajectory models of container drift should account for these uncertainties by generating search areas for different immersion levels and with the uncertainties in crosswind and downwind leeway reported from our field experiments.Comment: 25 pages, 11 figures and 5 tables; Ocean Dynamics, Special Issue on Advances in Search and Rescue at Sea (2012

Antiviral signaling by a cyclic nucleotide activated CRISPR protease

Funding information: M.G. and J.L.S.B. are funded by the Deutsche Forschungsgemeinschaft under Germany’s Excellence Strategy–EXC2151–390873048. M.F.W. acknowledges a European Research Council Advanced Grant (grant number 101018608) and the China Scholarship Council (REF: 202008420207 to H.C.). G.H. is grateful for funding by the Deutsche Forschungsgemeinschaft (grant number HA6805/6-1).CRISPR defense systems such as the well-known DNA-targeting Cas9 and the RNA-targeting type III systems are widespread in prokaryotes1,2. The latter can orchestrate a complex antiviral response that is initiated by the synthesis of cyclic oligoadenylates (cOAs) upon foreign RNA recognition3-5. Among a large set of proteins that were linked to type III systems and predicted to bind cOAs6,7, a CRISPR associated Lon protease (CalpL) stood out to us. The protein contains a sensor domain of the SAVED (SMODS-associated and fused to various effector domains) family7, fused to a Lon protease effector domain. However, the mode of action of this effector was unknown. Here, we report the structure and function of CalpL and show that the soluble protein forms a stable tripartite complex with two further proteins, CalpT and CalpS, that are encoded in the same operon. Upon activation by cA4, CalpL oligomerizes and specifically cleaves the MazF-homolog CalpT, releasing the extracytoplasmic function (ECF) sigma factor CalpS from the complex. This provides a direct connection between CRISPR-based foreign nucleic acid detection and transcriptional regulation. Furthermore, the presence of a cA4-binding SAVED domain in a CRISPR effector reveals an unexpected link to the cyclic oligonucleotide-based antiphage signaling system (CBASS).PostprintPeer reviewe

Rapport préliminaire sur les activités de la mission syro-française de Ras Shamra-Ougarit en 2007 et 2008 (67e et 68e campagnes)

Ce rapport présente les résultats préliminaires des travaux de terrain de la mission archéologique syro-française de Ras Shamra – Ougarit pour les campagnes de 2007 et 2008 qui se sont déroulées à Ras Shamra et sur plusieurs sites côtiers. Sur le tell de Ras Shamra, quatre opérations de fouilles ont été menées  : la poursuite du chantier du «  Rempart » et de celui de la «  Grand-rue », la reprise du dégagement du «  pont-barrage » sur le Nahr ed-Delbé et un nouveau chantier conjoint dans le secteur du «  Temple de Dagan ». Deux autres opérations ont commencé en 2008  : la prospection géomagnétique du tell et l’étude des techniques de taille de la pierre à Ougarit. Les travaux de la mission se sont portés également sur les sites côtiers du royaume d’Ougarit dans le cadre d’un nouveau programme conjoint visant à reconstituer l’évolution des paléo-environnements portuaires et la mobilité des paysages littoraux. La présentation des activités de terrain est complétée par une réflexion sur le plan de l’antique cité d’Ougarit et les premiers résultats de l’étude d’un atelier de travail du silex (Bronze récent final) mis au jour dans le chantier «  Grand-rue ».This report presents preliminary results from the Syrian-French archaeological excavations at Ras Shamra-Ugarit for the field seasons of 2007 and 2008, which took place at Ras Shamra and a number of coastal sites. At Ras Shamra tell, four excavations were undertaken : work continued at the sites of “Rempart” and “Grand-rue”, with further investigations of the “pont-barrage” on the Nahr ed-Delbe, in addition to a new joint site in the area of the “Temple de Dagan”. Two other projects began in 2008 : the geomagnetic survey of the tell and a study of the techniques of stone quarrying at Ugarit. The expedition’s work also extended to the coastal sites of the Kingdom of Ugarit within the framework of a new program looking to reconstruct the evolution of its harbours and mobility of the coastal landscapes. The presentation of the fieldwork activities is complemented by a piece looking at the plan of the ancient city of Ugarit and the first results of a study investigating a flint workshop (Late Bronze Age) unearthed at the “Grand-rue” site.خلاصة – يقدم هذا التقرير النتائج الأولية للبعثة الأثرية السورية-الفرنسية العاملة في موقع رأس شمرا- أوغاريت عن الأعمال تاميدانية في رأس شمرا خلال عامي 2007 و2008 وعدد من المواقع الساحلية. في موقع تل رأس شمرا، تمّ تنفيذ أربع عمليات حفر : إستكمال الحفريات في حقل « الأسوار» وحقل « الشارع الكبير»، ومتابعة أعمال الكشف على « الجسر-السد» على نهر الدلبة، بالإضافة الى المباشرة في تنفيذ تنقيب مشترك في حقل معبد « داغان». بالمقابل ثم المباشرة بتنفيذ عمليتين في أوغاريت خلال عام 2008 : عمليات مسح جيومغناطيسية للتل، ودراسة تقنية تتعلّق بطرق تقصيب وتشذيب أحجار البناء. تضمّنت أعمال البعثة أيضاً، العمل على المواقع الساحلية لمملكة أوغاريت وذلك ضمن إطار برنامج جديد مشترك يهدف إلى وضع تصوّر لتطوّر الظروف البيئية للمرافئ بالأضافة إلى تصوّر عام لكينونة الشريط الساحلي. إستكمال عرض الأعمال الميدانية بوضع تصوّر لمخطط المدينة القديمة لأوغاريت والنتائج الأولية لمشغل للأدوات الصوانية إكتشف في حقل « الشارع الكبير» يعود إلى عصر البرونز الحديث النهائي

A joint numerical study of multi-regime turbulent combustion

This article presents a joint numerical study on the Multi Regime Burner configuration. The burner design consists of three concentric inlet streams, which can be operated independently with different equivalence ratios, allowing the operation of stratified flames characterized by different combustion regimes, including premixed, non-premixed, and multi-regime flame zones. Simulations were performed on three LES solvers based on different numerical methods. Combustion kinetics were simplified by using tabulated or reduced chemistry methods. Finally, different turbulent combustion modeling strategies were employed, covering geometrical, statistical, and reactor based approaches. Due to this significant scattering of simulation parameters, a conclusion on specific combustion model performance is impossible. However, with ten numerical groups involved in the numerical simulations, a rough statistical analysis is conducted: the average and the standard deviation of the numerical simulation are computed and compared against experiments. This joint numerical study is therefore a partial illustration of the community's ability to model turbulent combustion. This exercise gives the average performance of current simulations and identifies physical phenomena not well captured today by most modeling strategies. Detailed comparisons between experimental and numerical data along radial profiles taken at different axial positions showed that the temperature field is fairly well captured up to 60 mm from the burner exit. The comparison reveals, however, significant discrepancies regarding CO mass fraction prediction. Three causes may explain this phenomenon. The first reason is the higher sensitivity of carbon monoxide to the simplification of detailed chemistry, especially when multiple combustion regimes are encountered. The second is the bias introduced by artificial thickening, which overestimates the species’ mass production rate. This behavior has been illustrated by manufacturing mean thickened turbulent flame brush from a random displacement of 1-D laminar flame solutions. The last one is the influence of the subgrid-scale flame wrinkling on the filtered chemical flame structure, which may be challenging to model.</p

A joint numerical study of multi-regime turbulent combustion

This article presents a joint numerical study on the Multi Regime Burner configuration. The burner design consists of three concentric inlet streams, which can be operated independently with different equivalence ratios, allowing the operation of stratified flames characterized by different combustion regimes, including premixed, non-premixed, and multi-regime flame zones. Simulations were performed on three LES solvers based on different numerical methods. Combustion kinetics were simplified by using tabulated or reduced chemistry methods. Finally, different turbulent combustion modeling strategies were employed, covering geometrical, statistical, and reactor based approaches. Due to this significant scattering of simulation parameters, a conclusion on specific combustion model performance is impossible. However, with ten numerical groups involved in the numerical simulations, a rough statistical analysis is conducted: the average and the standard deviation of the numerical simulation are computed and compared against experiments. This joint numerical study is therefore a partial illustration of the community's ability to model turbulent combustion. This exercise gives the average performance of current simulations and identifies physical phenomena not well captured today by most modeling strategies. Detailed comparisons between experimental and numerical data along radial profiles taken at different axial positions showed that the temperature field is fairly well captured up to 60 mm from the burner exit. The comparison reveals, however, significant discrepancies regarding CO mass fraction prediction. Three causes may explain this phenomenon. The first reason is the higher sensitivity of carbon monoxide to the simplification of detailed chemistry, especially when multiple combustion regimes are encountered. The second is the bias introduced by artificial thickening, which overestimates the species’ mass production rate. This behavior has been illustrated by manufacturing mean thickened turbulent flame brush from a random displacement of 1-D laminar flame solutions. The last one is the influence of the subgrid-scale flame wrinkling on the filtered chemical flame structure, which may be challenging to model.</p

Contribution of the European Volcanology community to the implementation of the EPOS infrastructure for accessing geoscience data

The 27th IUGG General Assembly in Montréal, Québec, Canada.,vJuly 8-18, 2019.During the last decade, the European volcanological community has undertaken a process of community building in the frame of the European Plate Observing System (EPOS) projects. The tangible outcome of this effort is the `Volcano Observations¿ Thematic Core Service (VO-TCS), which aim is the definition of a clear legal and technical frame for the coordination of the European volcanology community, and management and accessibility of its huge scientific heritage. The VO-TCS is currently developing facilities allowing long-term, easy access to volcanological data and products, and interoperable services provided by its Volcano Observatories (VOs) and Research Institutions (VRIs). The VO-TCS will offer virtual access to data, products, services, and computational platforms, and it is also defining the rules and procedures to properly allow transnational access to its volcanological facilities. The portfolio of data, products, software, and services is quite broad and varied, ranging from geophysics and geochemistry to volcanology. Data collection and analysis varies from in-situ and remote sensing observations to experimental analysis and computational elaborations. Overall, the TCS VOs and VRIs will provide quantitative, high-quality observations on the European volcanoes and the geodynamic background of the surrounding areas. For the purpose, VO-TCS has been integrating the experiences gained in monitoring and studying the Italian, Icelandic, French, Spanish, Greek, and Portuguese volcanoes. A first concrete result of the implementation of the VO-TCS is the H2020 EUROVOLC project, started in February 2018, which aims at networking the European volcanological community by supporting joint research activities and virtual/physical/ remote accesses to selected facilities

Representation of water abstraction from a karst conduit with numerical discrete-continuum models

Karst aquifers are characterized by highly conductive conduit flow paths embedded in a less conductive fissured and fractured matrix resulting in strong permeability contrasts with structured heterogeneity and anisotropy. Groundwater storage occurs predominantly in the fissured matrix. Hence, most karst models assume quasi steady-state flow in conduits neglecting conduit associated drainable storage (CADS). The concept of CADS considers storage volumes, where karst water is not part of the active flow system but rather hydraulically connected to conduits (for example karstic voids and large fractures). The disregard of conduit storage can be inappropriate when direct water abstraction from karst conduits occurs, e.g. large scale pumping. In such cases, CADS may be relevant. Furthermore, the typical fixed head boundary condition at the karst outlet can be inadequate for water abstraction scenarios because unhampered water inflow is possible. The objective of this paper is to analyze the significance of CADS and flow-limited boundary conditions on the hydraulic behavior of karst aquifers in water abstraction scenarios. To this end, the numerical hybrid model MODFLOW-2005 Conduit Flow Process Mode 1 (CFPM1) is enhanced to account for CADS. Additionally, a fixed-head limited-flow (FHLQ) boundary condition is added that limits inflow from constant head boundaries to a user-defined threshold. The affect and proper functioning of these modifications is demonstrated by simplified model studies. Both enhancements, CAD storage and the FHLQ boundary, are shown to be useful for water abstraction scenarios within karst aquifers. An idealized representation of a large-scale pumping test in a karst conduit is used to demonstrate that the enhanced CFPM1 is potentially able to adequately represent water abstraction processes in both the conduits and the matrix of real karst systems

The contribution of the European Volcanology community to the implementation of the European Plate Observing System (EPOS) infrastructure

EGU General Assembly in Viena, Austria,7–12 April 2019During the last decade, the European volcanological community has undertaken a process of community building in the frame of the two European Plate Observing System (EPOS) projects: the ECFP7 Preparatory Phase, which ended in 2014, and the ongoing EC H2020 Implementation Phase. The tangible outcome of this effort is the ‘Volcano Observations’ Thematic Core Service (VO-TCS), which aim is the definition of a clear legal and technical frame for the coordination of the European volcanology community, and management and accessibility of its huge scientific heritage. The VO-TCS is currently developing facilities allowing long-term, easy access to volcanological data and products, and interoperable services provided by its Volcano Observatories and Research Institutions. The VO-TCS will offer virtual access to data, products, services, and computational platforms, and it is also defining the rules and procedures to properly allow transnational access to its volcanological facilities. The portfolio of data, products, software, and services is quite broad and varied, ranging from geophysics and geochemistry to volcanology. Data collection and analysis varies from in-situ and remote sensing observations to experimental analysis and computational elaborations. Overall, the TCS Volcano Observatories and Research Institutions will provide quantitative, high-quality observations on the European volcanoes and the geodynamic background of the surrounding areas. For the purpose, VO-TCS has been integrating the experiences gained in monitoring and studying the Italian, Icelandic, French, Spanish, Greek, and Portuguese volcanoes. A first concrete result of the implementation of the VO-TCS is the H2020 EUROVOLC project, started in February 2018, which aims at networking the European volcanological community by supporting joint research activities and virtual/physical/ remote accesses to selected facilities. Actually, the community involved in EUROVOLC is broader than that implementing the VO-TCS. The VO-TCS has also the potential to link with multiple international communities; such has already been initiated with the IAVCEI WOVO Commission (World Organization of Volcano Observatories) which is the reference worldwide community building initiative for the volcanological community. Technical solutions and best practices for data access will be shared between VO-TCS and WOVOdat global database. Once, the access to VO-TCS has been definitively set out, the volcanology community expects that the multidisciplinary portfolio of the volcanological databases offered will also attract communities from other domains (e.g. climatology, atmospheric science, biology, etc.). Examples of this potentiality are the experiences carried out in the transnational accesses managed in the frame of the ENVRIPlus EC H2020 project on Mt. Etna observatory. In this initial state, the institutions contributing to the implementation of the VO-TCS are: Centre National de la Recherche Scientifique (CNRS; Units of “Institut the Physique du Globe “ and “Université Clermont Auvergne”); Consejo Superior de Investigaciones Científicas (CSIC); Dublin Institute for Advanced Studies (DIAS); GeoForschungsZentrum (GFZ); Institute of Geology & Mineral Exploration (IGME); Instituto Geográfico Nacional (IGN); Icelandic Meteorological Office (IMO); Istituto Nazionale di Geofisica e Vulcanologia (INGV); Universidade dos Açores (UAc); and University of Bristol (UB); University of Iceland (UI). In the future, the VO-TCS envisages the contribution of many other universities and research institutions around Europe