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The paper describes formation and spreading of dense shelf waters in the Adriatic Sea (North Adriatic Dense Water, NAdDW) during the winter of 2012 as a consequence of an intense and long cold air outbreak of northeasterly Bora winds. As a result, during February 2012 northern Adriatic Sea water temperature dropped to about 6 degrees C and density exceeded 1030 kg/m(3), most likely the maximum value since 1929. NAdDW dynamics has been investigated by means of a 3-D ocean-wave coupled model running on a high resolution and eddy-permitting grid. The numerical experiments have relied on the Coupled-Ocean-Atmosphere-Wave-Sediment-Transport (COAWST) system forced one-way with atmospheric forcings provided by the model COSMO-17. A suite of observational data has been used to characterize the Bora event and evaluate numerical model performance. At sub-basin scales, the newly formed waters flowing southerly have produced a water renewal of the northern Adriatic, as more than 50% of water volumes have left the basin. Dense waters volume transports, evaluated through different Adriatic cross-sections, have been modulated by tides (damped for the densest water masses) and reached about 1 Sv. The contribution of wave-induced forcings has been quantified and examined, indicating that these represent a major driving mechanism during NAdDW production and spreading phases. This work provides evidence that NAdDW is spread accordingly with two different mechanisms: at early stages of its formation, the wind-driven ocean circulation pushes newly formed waters to leave the northern basin with relatively high speeds (about 0.30 m/s). Later on, remaining NAdDW leaks slowly out (0.09 m/s as average) from the production site. Residence times of dense waters in the north, middle, and south Adriatic Sea are also documented. (C) 2014 Elsevier Ltd. All rights reserved.

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Abstract An analysis of the integration of a Ca-looping process into a cement plant is presented. The capture process, based on selective absorption of CO2 by calcium oxide, has two interconnected reactors where the carbonator captures CO2 from the preheater flue gases and the calciner regenerates the CaCO3 into CaO by oxy-combustion. The study also considers the purge rate of part of the circulating CaO, given the tendency of the material to sinter and reduce its capture capacity. Fresh CaCO3 is added to maintain reactivity in the carbonator, while the purged sorbents are utilised as a cement kiln feed. The detailed carbonator model has been implemented using Matlab and incorporated into Unisim to provide a full flowsheet simulation for an exemplary dry-feed cement plant as a user-defined operation. The effect of molar flowrate ratio of lime make-up to feed CO2 ( F 0 / F CO 2 ) between two operational limits has been investigated. This process configuration is capable of achieving over 90% CO2 capture with additional fuel consumption of 2.5–3.0 GJth/ton CO2 avoided which depends on the F 0 / F CO 2 ratio. It is found that a proper heat recovery system supplementary to the Ca-looping process makes the Ca-looping process more competitive than the traditional low temperature absorption process based on amine solvents.

The effects of changes in climate predicted for 2100—reduction in recharge, increase in water demand and sea-level rise—on groundwater volume and saltwater intrusion have been quantified in the Maltese Islands, an archipelago located at the center of the Mediterranean Sea. A three-dimensional density dependent and heterogeneous model, working in transient conditions, was developed based on morphological and geological information. The hydraulic conductivity and porosity of the lithological formations were derived from previous tests and studies conducted on the islands. The complex fault system intersecting the area has also been included in the model. The results show that among the three considered factors affecting groundwater resources, the most significant is the increase in water demand, which is closely followed by the decrease in groundwater recharge. Sea-level rise plays a marginal role. The 80-year simulation period showed that these combined impacts would cause a loss of more than 16% of groundwater volume.

High current lightning strikes into earthing systems \ud can result in ionization in the soil surrounding the earthing electrode. Most of the published studies investigating this phenomenon have assumed uniform one-layer soil, but soil ionization propagation in a multilayered soil sample has not \ud been extensively addressed. Practical soils may consist of several layers with different water contents, and hence soil resistivity will vary continuously with depth. This investigation considers several sand samples, consisting of two layers with different \ud water contents subjected to standard lightning impulse voltages. A rod-plane electrode configuration was constructed inside a cylindrical plastic test rig, in order to house both wet and dry soil test samples. In order to quantify the propagation of ionization inside the test sample, voltage probes were installed \ud along the tube at specific positions. Localized changes in the ionization zone potential could, therefore, be monitored in real time.

Abstract Standardization of biogas technology is immensely important for the promotion of the biogas industry worldwide. China has built a complete biogas standard system, which is divided into common, household biogas, biogas engineering, biogas digester for domestic sewage treatment, output utilization, and service system standards. The problems and potential barriers for biogas standardization in China are analyzed and come down to sluggish standard, overlapped standard, government-dominated standard, and lagging international standard. Accordingly, all potential biogas standards should be evaluated and placed under the same department. China Biogas Society and China Association of Rural Energy Industry play leading roles in developing enterprise or group/association biogas standards and ISO biogas standards. The bio-natural gas standard system and experimental standardization should be developed as well to replenish biogas standard system. A paradigm shift in biogas standardization should be from government-dominated to market-oriented model. The lessons learned for other developing countries includes expanding standardization to multi-aspects to realize full lifecycle control and management, building rapid responding mechanism of standardization to adopt industry transformation, integrating outdated standards into new versions, and establishing market-based standard system.

Seaweed assemblages represent the dominant autotrophic biomass in many coastal environments, playing a central structural and functional role in several ecosystems. In Europe, seaweed assemblages are highly diverse systems. The combined seaweed flora of different European regions hold around 1550 species (belonging to nearly 500 genera), with new species continuously uncovered, thanks to the emergence of molecular tools. In this manuscript we review the effects of global and local stressors on European seaweeds, their communities, and ecosystem functioning. Following a brief review on the present knowledge on European seaweed diversity and distribution, and the role of seaweed communities in biodiversity and ecosystem functioning, we discuss the effects of biotic homogenization (invasive species) and global climate change (shifts in bioclimatic zones and ocean acidification) on the distribution of individual species and their effect on the structure and functioning of seaweed communities. The arrival of new introduced species (that already account for 5–10% of the European seaweeds) and the regional extirpation of native species resulting from oceans' climate change are creating new diversity scenarios with undetermined functional consequences. Anthropogenic local stressors create additional disruption often altering dramatically assemblage's structure. Hence, we discuss ecosystem level effects of such stressors like harvesting, trampling, habitat modification, overgrazing and eutrophication that impact coastal communities at local scales. Last, we conclude by highlighting significant knowledge gaps that need to be addressed to anticipate the combined effects of global and local stressors on seaweed communities. With physical and biological changes occurring at unexpected pace, marine phycologists should now integrate and join their research efforts to be able to contribute efficiently for the conservation and management of coastal systems.