Exchange of polycyclic aromatic hydrocarbons across the air-water interface in the Bohai and Yellow Seas

In this study, air and surface seawater samples collected from the Bohai (BS) and Yellow Seas (YS) in May 2012 were determined exchange of PAHs, especially of low-molecular-weight (LMW) PAHs (three- and four-ring PAHs) at the air-water interface. Net volatilization fluxes of LMW PAHs were 266-1454 ng/m(2)/d and decreased with distance from the coast, indicating that these PAHs transported from coastal runoff were potential contributors to the atmosphere in the BS and YS. Moreover, LMW PAHs were enriched in the dissolved phase compared with those in the particulate phase in the water column, possibly suggesting that the volatilized LMW PAHs were directly derived from wastewater discharge or petroleum pollution rather than released from contaminated sediments. The air-sea exchange fluxes of the three-ring PAHs were 2- to 20-fold higher than their atmospheric deposition fluxes in the BS and YS. The input to and output from the water reached equilibrium for four-ring PAHs. Differently, five- and six-ring PAHs were introduced into the marine environment primarily through dry and wet deposition, indicating that the water column was still a sink of these PAHs from the surrounding atmosphere. (C) 2016 Elsevier Ltd. All rights reserved

Pan-cancer analysis of whole genomes

Cancer is driven by genetic change, and the advent of massively parallel sequencing has enabled systematic documentation of this variation at the whole-genome scale(1-3). Here we report the integrative analysis of 2,658 whole-cancer genomes and their matching normal tissues across 38 tumour types from the Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium of the International Cancer Genome Consortium (ICGC) and The Cancer Genome Atlas (TCGA). We describe the generation of the PCAWG resource, facilitated by international data sharing using compute clouds. On average, cancer genomes contained 4-5 driver mutations when combining coding and non-coding genomic elements; however, in around 5% of cases no drivers were identified, suggesting that cancer driver discovery is not yet complete. Chromothripsis, in which many clustered structural variants arise in a single catastrophic event, is frequently an early event in tumour evolution; in acral melanoma, for example, these events precede most somatic point mutations and affect several cancer-associated genes simultaneously. Cancers with abnormal telomere maintenance often originate from tissues with low replicative activity and show several mechanisms of preventing telomere attrition to critical levels. Common and rare germline variants affect patterns of somatic mutation, including point mutations, structural variants and somatic retrotransposition. A collection of papers from the PCAWG Consortium describes non-coding mutations that drive cancer beyond those in the TERT promoter(4); identifies new signatures of mutational processes that cause base substitutions, small insertions and deletions and structural variation(5,6); analyses timings and patterns of tumour evolution(7); describes the diverse transcriptional consequences of somatic mutation on splicing, expression levels, fusion genes and promoter activity(8,9); and evaluates a range of more-specialized features of cancer genomes(8,10-18).Peer reviewe

Erratum to: 36th International Symposium on Intensive Care and Emergency Medicine

[This corrects the article DOI: 10.1186/s13054-016-1208-6.]

CO2 hydrogenation to methanol over Cd4/TiO2 catalyst: Insight into multifunctional interface

Supported metal catalysts have shown to be efficient for CO 2 conversion due to their multifunctionality and high stability. Herein, we have combined density functional theory calculations with microkinetic modeling to investigate the catalytic reaction mechanisms of CO 2 hydrogenation to CH 3OH over a recently reported catalyst of Cd 4/TiO 2. Calculations reveal that the metal-oxide interface is the active center for CO 2 hydrogenation and methanol formation via the formate pathway dominates over the reverse water-gas shift (RWGS) pathway. Microkinetic modeling demonstrated that formate species on the surface of Cd 4/TiO 2 is the relevant intermediate for the production of CH 3OH, and CH 2O # formation is the rate-determining step. These findings demonstrate the crucial role of the Cd-TiO 2 interface for controlling the CO 2 reduction reactivity and CH 3OH selectivity. ChemE/Inorganic Systems Engineerin

Loop detector data error diagnosing and interpolating with probe vehicle data

Traffic volume and queue length are two important variables to identify traffic states in urban areas. Loop detectors are often used for monitoring traffic. A prominent weakness of loop detector data is the limited reliability due to equipment malfunctions and communication faults. This paper presents a method to identify the validity of loop detector measurements by analyzing the ratio of counts on adjacent lanes. GPS data from probe vehicles are an alternative for monitoring traffic states. They include instantaneous speed, acceleration and position; individual vehicle trajectories can be grossly estimated in real time. Consequently, the queue length can be measured approximately. This can be used to estimate traffic volumes and the percentage of probe vehicles. By combining loop detector and GPS data, more information regarding traffic status can be extracted from both data sources. This paper discusses two methods to check the volume counts and to fill in missing or invalid data: one method uses the ratio of loop detector counts on adjacent links, the other one uses data from probe vehicles to estimate the traffic volumes from the dynamics of the queue length at signalized intersections. Real data from the city Changsha in China are used to validate these two methods. The developed methods provide a way for the online monitoring of detectors’ performance and level of service at signalized intersectionsTransport and PlanningCivil Engineering and Geoscience

Mechanistic Investigation of Vertical Sweep Efficiency in Miscible CO2-Water- Coinjection for EOR and CCUS

The main objective of this study is to understand the vertical sweep efficiency with miscible CO2-water-coinjection as a secondary recovery method, from multiple perspectives: phase behavior, total relative mobility, fluid densities/viscosities, the driving forces and consequent phase distributions etc. We also seek to provide insights into modeling approaches for representing the injection process by comparing compositional simulation results to those of the fractional-flow method and the model of Stone and Jenkins ( Stone, 1982 ; Jenkins, 1984 ).We combine compositional simulation and analytical models to interpret the dynamics that affect vertical sweep efficiency in miscible CO2-water-coinjection. Stone’s model for gravity segregation at steady state predicts three phase-distribution zones: mixed zone, override zone and underride zone. In addition to these three zones, we identify from simulations an extended mixed zone and extended override zone in miscible CO2-water-coinjection, contributing to additional oil recovery and CO2 trapping. The extended zones are a result of dispersion that reflects physical and numerical dispersion in the gas-oil displacement front. To the extent that it reflects numerical dispersion, the extended zones can be considered as a numerical artifact.Atmospheric Remote Sensin

Advanced numerical study of the response of orthotropic steel deck bridge with two membrane layers system

In the Netherlands an asphaltic surfacing structure for orthotropic steel bridge decks mostly consists of two structural layers. The upper layer consists of Porous Asphalt (PA) because of reasons related to noise hindrance. For the lower layer a choice between Mastic Asphalt (MA) or Guss Asphalt (GA), can be made. In this paper, a typical Dutch steel bridge deck surfacing system is simulated by means of the three-dimensional fmite element system CAPA 3D. Special attention is given to the structural distress phenomena and the parameters that influenced them. The FE model shows the distribution of strains and stresses inside the surfacing materials depends highly on the wheel load level, wheel load frequency, wheel position, membrane bonding strength as well as the thicknesses and the characteristics of the surfacing layers.Structural EngineeringCivil Engineering and Geoscience

Modelling of five-point bending beam test for asphalt surfacing system on orthotropic steel deck bridges

The orthotropic steel deck bridges (OSDBs) in the Netherlands consists mostly of multilayer system: top porous asphalt layer, guss asphalt layer, steel deck and two membrane layers. The five-point bending (5PB) beam test is the standard device in France for characterization of fatigue response of asphalt concrete surfacings used on orthotropic steel deck bridges. In this paper, an analytical solution for the 5PB beam test setup is presented first. In order to better understand the influence of geometrical, mechanical and structural parameters on the performance of the typical multilayer surfacing system of OSDBs, the 5PB test specimens with five structural layers have been investigated. The parametric study is performed at the numerical platform CAPA-3D that was developed at the Section of Structural Mechanics of TU Delft. The influences of the thickness of the asphalt layers and the mechanical properties of both top and bottom membrane layers are studied. The sensitivities of those influence factors are evaluated by the examination of the maximum tensile stress at the top surface of the porous asphalt layers and the strain distributions through the entire thickness of the specimen at two cross-sections.Pavement EngineeringSanitary Engineerin

Finite element of multilayer surfacing systems on orthotropic steel bridges

Light weight orthotropic steel bridge decks have been widely utilized for bridges in seismic zones, movable bridges and long span bridges. In the last three decades, severe problems were reported in relation to asphaltic surfacing materials on orthotropic steel deck bridges. Earlier investigations have shown that the bonding strength of membrane layers to the surrounding materials has a strong influence on the structural response of orthotropic steel bridge decks. The most important requirement for the application of membrane materials on orthotropic steel bridge decks is that the membrane adhesive layer shall be able to provide sufficient bond to the surrounding materials. The research aims on developing a FE tool to simulate and understand the performance of asphaltic surfacing structures, so as to improve the design of surfacings and increase their service life. In this paper, Finite Element (FE) simulations of Merwedebrug bridge with two membrane layers system are presented. The finite element system CAPA-3D developed at the Section of Structural Mechanics of TU Delft has been utilized as the numerical platform for this study. Due to the multilayer of the surfacing materials and geometrical complexity of the steel bridge, the FE model shows the in time development of strains and stresses inside the surfacing materials depends highly on the wheel loading frequency, wheel position, membrane bonding strength as well as thicknesses and characteristics of the surfacing layers. Emphasis is placed on the distribution of strains and the evolution of damage in surfacing layers of different cases. Recommendations of surfacing structures design on orthotropic steel bridges are given.Structural EngineeringCivil Engineering and Geoscience

Microstructure–property relation and machine learning prediction of hole expansion capacity of high-strength steels

Abstract: The relationship between microstructure features and mechanical properties plays an important role in the design of materials and improvement of properties. Hole expansion capacity plays a fundamental role in defining the formability of metal sheets. Due to the complexity of the experimental procedure of testing hole expansion capacity, where many influencing factors contribute to the resulting values, the relationship between microstructure features and hole expansion capacity and the complexity of this relation is not yet fully understood. In the present study, an experimental dataset containing the phase constituents of 55 microstructures as well as corresponding properties, such as hole expansion capacity and yield strength, is collected from the literature. Statistical analysis of these data is conducted with the focus on hole expansion capacity in relation to individual phases, combinations of phases and number of phases. In addition, different machine learning methods contribute to the prediction of hole expansion capacity based on both phase fractions and chemical content. Deep learning gives the best prediction accuracy of hole expansion capacity based on phase fractions and chemical composition. Meanwhile, the influence of different microstructure features on hole expansion capacity is revealed. Graphical abstract: [Figure not available: see fulltext.]Team Jilt SietsmaStatisticsDelft Institute of Applied Mathematic