Microwave heating presents a potentially green alternative for energy supply to chemical and catalytic reactors as it can be based on the electricity from renewable sources. The Reverse Traveling Microwave Reactor (RTMR) is a novel heterogeneous catalytic reactor concept, based on the coaxial waveguide structure. The reactor has two microwave ports on both ends, and microwave irradiation is periodically switched between those ports to minimize the temperature gradients along the catalyst bed. In the current paper, COMSOL MULTIPHYSICS® simulation environment has been used to develop a 3D multiphysics model of the RTMR. Based on the model, operational characteristics of the reactor including electric field distribution and transient temperature profiles have been studied. Simulation results show that periodically reversed microwave irradiation improves the homogeneity of the temperature distribution inside the catalyst bed. The study provides new insights into the design and scale-up of microwave-assisted catalytic flow processes.

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The dynamic origin-destination (OD) information is crucial for traffic operations and control. This paper presents a dynamic traffic demand prediction framework based on an anomaly detection algorithm. The Principal Component Analysis (PCA) method is applied to extract main demand patterns which are used to detect the abnormal conditions. The proposed approach can select prediction methods (parametric or nonparametric) automatically based on the pattern detection results. Both simulation and field observed Automatic Number Plate Recognition (ANPR) data are used to verify the proposed approach where the Kalman filter model and the K-nearest neighbor model are chosen as the basic prediction methods. The results show that the prediction framework can effectively reduce the noise of a single prediction model particularly in the abnormal conditions and provide more accurate and reliable prediction results.@en

BACKGROUND: Ultrasound guidance of cryotherapy could be improved if changes of tissue characterization parameters during freezing could be used to monitor freezing profiles and estimate frostbite distributions. OBJECTIVE: To investigate if B-mode ultrasonic imaging can provide sufficient information to define the damaged zone during cryotherapy by quantifying the differences of texture features between fresh and frozen-thawed porcine liver tissue. MATERIALS AND METHODS: The B-mode ultrasonic images were obtained from ten porcine liver tissue samples before and after frozen-thawing treatment, then 20 texture parameters of the grey level histogram (GLH) and the grey level co-occurrence matrix (GLCM) from each image were extracted and analyzed statistically. RESULTS: It was found that the differences in two texture parameters between the fresh and frozen-thawed tissue are significant enough for diagnostic purpose (variance: 317.0%, contrast: 144.4%). CONCLUSION: Texture feature analysis of B-mode ultrasonic images can effectively differentiate the fresh and frozen-thawed porcine liver tissues, which offers a prospect for the future practice of evaluating the effectiveness of cryotherapy using Ultrasound.

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We present an experimental method to study time-dependent, CO2-induced, local topography changes in mm-sized composite samples, plus results showing heterogeneous swelling of coal and shale on the nano- to micrometer scale. These results were obtained using high resolution interferometry measurements of sample topography, combined with a new type of experimental microfluidic device. This device is a custom-built pressure vessel, which can contain any impermeable sample type and can be placed under any microscope. The pressure vessel itself has been tested to handle pressures up to 100 bar at room temperature conditions. For the experiments reported here we used three sample types: i) epoxy and dolomite, ii) coal, epoxy and dolomite and iii) shale. These model systems (thicknesses between 2 and 10 mm) were exposed to pressurized CO2 (20–35 bars) and subsequently deformation over time was monitored with a white light interferometer. This provided a lateral spatial resolution of 979 nm and a vertical spatial resolution of 200 nm, i.e. sufficient resolution so that coal and shale constituents can be tracked individually. Within 72 h epoxy swells homogeneously up to 11 μm, coal swells 4 ± 1 μm and dolomite is unreactive with the dry CO2 injected here, and as such is used as a reference surface. The differential swelling of coal can be correlated in space with the macerals, where macerals with an initial higher topography swell more. The average or bulk swelling exhibits an approximate t½ relation, indicative of diffusion-controlled adsorption of CO2 on the organic matter. Measurements of the differential swelling of both shale samples enabled tracking of individual patches of organic matter within the shale (max. 20 × 20 μm). These patches exhibit finite swelling of on average 250 nm in 4 h (in the Pomeranian shale) and 850 μm in 20 h (in the Green River shale), where total swelling is assumed to be related to the volume of the patches of organic matter.@en

Target 6.4 of the recently adopted Sustainable Development Goals (SDGs) deals with the reduction of water scarcity. To monitor progress towards this target, two indicators are used: Indicator 6.4.1 measuring water use efficiency and 6.4.2 measuring the level of water stress (WS). This paper aims to identify whether the currently proposed indicator 6.4.2 considers the different elements that need to be accounted for in a WS indicator. WS indicators compare water use with water availability. We identify seven essential elements: 1) both gross and net water abstraction (or withdrawal) provide important information to understand WS; 2) WS indicators need to incorporate environmental flow requirements (EFR); 3) temporal and 4) spatial disaggregation is required in a WS assessment; 5) both renewable surface water and groundwater resources, including their interaction, need to be accounted for as renewable water availability; 6) alternative available water resources need to be accounted for as well, like fossil groundwater and desalinated water; 7) WS indicators need to account for water storage in reservoirs, water recycling and managed aquifer recharge. Indicator 6.4.2 considers many of these elements, but there is need for improvement. It is recommended that WS is measured based on net abstraction as well, in addition to currently only measuring WS based on gross abstraction. It does incorporate EFR. Temporal and spatial disaggregation is indeed defined as a goal in more advanced monitoring levels, in which it is also called for a differentiation between surface and groundwater resources. However, regarding element 6 and 7 there are some shortcomings for which we provide recommendations. In addition, indicator 6.4.2 is only one indicator, which monitors blue WS, but does not give information on green or green-blue water scarcity or on water quality. Within the SDG indicator framework, some of these topics are covered with other indicators.

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The influence of highly nitrogen-doped mesoporous carbon spheres (NMCSs) (internal pore size of 5.4–16 nm) on the electrochemical response of low carbon steel (St37) in model alkaline solutions of pH 13.9 and 12.8 was studied, using Open Circuit Potential (OCP) monitoring, Electrochemical Impedance Spectroscopy (EIS) and Cyclic Voltammetry (CV). Prior to adding the NMCSs in the relevant solutions, they were characterized in the same model medium by measuring their Zeta-potential, hydrodynamic radius and particle size distribution, using dynamic light scattering (DLS) and transmission electron microscopy (TEM). In alkaline environment of pH 13.9 and 12.8, which simulates the concrete pore water of fresh and mature concrete, the DLS measurements indicated that the hydrodynamic radius of NMCSs particle varied from 296 nm to 183, respectively. According to the Zeta-potential measurements in the same solutions, the NMCSs were slightly positively charged.

The addition of 0.016 wt.% of NMCSs to the model medium induced certain variation in the electrochemical response of the tested steel. In alkaline solutions of pH 12.8, the presence of NMCSs in the passive film/solution interface induced a delay in the formation of a stable passive film. On the other hand, in solutions of pH 13.9, the higher corrosion activity on the steel surface, enhanced by high pH, was limited by adsorption of NMCSs on the film/substrate interface. In addition competing mechanisms of active state, i.e., enhanced oxidation on the one hand, and particles adsorption on anodic sites and oxidation limitation, on the other hand, was relevant in solution of pH 13.9 inducing larger fluctuations in impedance response and stabilization only towards the end of the testing period.

Except steel electrochemical response, the properties of the cement-based bulk matrix were investigated in the presence of the aforementioned additives. The mortar bulk matrix properties were highly affected by NMCSs. The lowest electrical resistivity values were recorded in mortar specimens with mixed-in 0.025 wt.% NMCSs (with respect to dry cement weight). Furthermore, the addition of 0.025 wt.% NMCSs increased the compressive strength when compared to control specimens. The presence of F127 as a dispersing agent for NMCSs was found to be not suitable for reinforced concrete applications, which is in view of the reduced mechanical strength and electrical resistivity of the cement-based bulk matrix. This is in addition to the adverse effect on the formation of electrochemically stable passive layer on steel surface in alkaline medium in its presence.
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In 2013, the International Association of Hydrological Sciences (lAHS) launched the hydrological decade 2013-2022 with the theme "Panta Rhei; Change in Hydrology and Society". The decade recognizes the urgency of hydrological research to understand and predict the interactions of society and water, to support sustainable water resource use under changing climatic and environmental conditions. This paper reports on the first Panta Rhei biennium 2013-2015, providing a comprehensive resource that describes the scope and direction of Panta Rhei. We bring together the knowledge of all the Panta Rhei working groups, to summarize the most pressing research questions and how the hydrological community is progressing towards those goals. We draw out interconnections between different strands of research, and reflect on the need to take a global view on hydrology in the current era of human impacts and environmental change. Finally, we look back to the six driving science questions identified at the outset of Panta Rhei, to quantify progress towards those aims. @en

Creating vibrant urban places is a challenging task in urban design due to the intangible feature of urbanity. This paper presents Form Syntax, a design analytical tool that is capable of assisting urbanity making in design practices based on understandings of three essential urban morphological elements and their influences on urbanity. Using the geographical information system (GIS), Form Syntax integrates three methods—Space Syntax, Spacematrix, and Mixed-Use Index—to measure the street-network configuration, building density, and functional mix, respectively. These three components can be quantified and combined to represent urban morphological features, thereby providing a classification of the degree of urbanity. Form Syntax contributes to geodesign by combining quantitative tools with traditional, intuition-based design to achieve a clear visualisation of the degree of urbanity of a place, which can subsequently be used to propose spatial strategies for enhancing vibrant urban places. The Dutch city of Rotterdam is used to illustrate how the tool improves the traditional site analysis, idea evaluation, and proposal evaluation phases of urban design. A GIS add-in has been developed to enhance the appeal of Form Syntax among urban design practitioners.@en

Various physical interfacial phenomena occur during the process of welding and influence the final properties of welded structures. As the features of such interfaces depend on physics that resolve at different spatial scales, a multiscale and multiphysics numerical modeling approach is necessary. In a collaborative research project Modeling of Interface Evolution in Advanced Welding, a novel strategy of model linking is employed in a multiscale, multiphysics computational framework for fusion welding. We only directly link numerical models that are on neighboring spatial scales instead of trying to link all submodels directly together through all available spatial scales. This strategy ensures that the numerical models assist one another via smooth data transfer, avoiding the huge difficulty raised by forcing models to attempt communication over many spatial scales. Experimental activities contribute to the modeling work by providing valuable input parameters and validation data. Representative examples of the results of modeling, linking and characterization are presented.@en