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Car-sharing services are developing at an ever-increasing pace. Taking into account the reduction of carbon dioxide emissions and pursuit of the sustainable development of transport, implementing electric cars in car-sharing fleets is being proposed. On the one hand, these types of vehicles are referred to as emission-free, but on the other hand, their environmental friendliness is questionable due to the emission of carbon dioxide during the production of energy to power them. Although many scientific papers are devoted to the issue of reducing emissions through car sharing, there is a research gap concerning the real production of carbon dioxide by car-sharing vehicles during car-sharing trips. To fill this research gap, the objective of the article was to analyze the actual level of carbon dioxide emissions from combustion and electric vehicles from car-sharing systems produced when renting rides. The test results showed that the electric car turned out to be significantly less emitting. The use of electric vehicles in car-sharing fleets can reduce carbon dioxide emissions from 14% to 65% compared to using cars with internal combustion engines. However, the key role during car-sharing trips is played by the driving style of the drivers, which has been omitted from the literature to date. This should be properly regulated by service providers and focus on the proper use of energy from electric vehicle batteries, especially at low temperatures. The article provides support for operators planning to modernize their fleet of vehicles and fills the research gap concerning car-sharing emissions.

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.

In Eastern Boundary Upwelling Systems nutrient-rich waters are transported to the ocean surface, fuelling high photoautotrophic primary production. Subsequent heterotrophic decomposition of the produced biomass increases the oxygen-depletion at intermediate water depths, which can result in the formation of oxygen minimum zones (OMZ). OMZs can sporadically accumulate hydrogen sulfide (H2S), which is toxic to most multicellular organisms and has been implicated in massive fish kills. During a cruise to the OMZ off Peru in January 2009 we found a sulfidic plume in continental shelf waters, covering an area >5500 km(2), which contained ∼2.2×10(4) tons of H2S. This was the first time that H2S was measured in the Peruvian OMZ and with ∼440 km(3) the largest plume ever reported for oceanic waters. We assessed the phylogenetic and functional diversity of the inhabiting microbial community by high-throughput sequencing of DNA and RNA, while its metabolic activity was determined with rate measurements of carbon fixation and nitrogen transformation processes. The waters were dominated by several distinct γ-, δ- and ε-proteobacterial taxa associated with either sulfur oxidation or sulfate reduction. Our results suggest that these chemolithoautotrophic bacteria utilized several oxidants (oxygen, nitrate, nitrite, nitric oxide and nitrous oxide) to detoxify the sulfidic waters well below the oxic surface. The chemolithoautotrophic activity at our sampling site led to high rates of dark carbon fixation. Assuming that these chemolithoautotrophic rates were maintained throughout the sulfidic waters, they could be representing as much as ∼30% of the photoautotrophic carbon fixation. Postulated changes such as eutrophication and global warming, which lead to an expansion and intensification of OMZs, might also increase the frequency of sulfidic waters. We suggest that the chemolithoautotrophically fixed carbon may be involved in a negative feedback loop that could fuel further sulfate reduction and potentially stabilize the sulfidic OMZ waters.

The growing number of electric vehicles in recent years is observable in almost all countries. The country’s energy transition should accompany this rise in electromobility if it is currently generated from non-renewable sources. Only electric vehicles powered by renewable energy sources can be considered zero-emission. Therefore, it is essential to conduct interdisciplinary research on the feasibility of combining energy recovery/generation structures and testing the energy consumption of electric vehicles under real driving conditions. This work presents a comprehensive approach for evaluating the energy consumption of a modern public building–electric vehicle system within a specific location. The original methodology developed includes surveys that demonstrate the required mobility range to be provided to occupants of the building under consideration. In the next step, an energy balance was performed for a novel near-zero energy building equipped with a 199.8 kWp photovoltaic installation, the energy from which can be used to charge an electric vehicle. The analysis considered the variation in vehicle energy consumption by season (winter/summer), the actual charging profile of the vehicle, and the parking periods required to achieve the target range for the user.

Abstract Zostera marina is an aquatic plant forming wide grasslands and considered as the lungs of the marine ecosystems. However, the residues reaching the coastlines create nuisance and high costs are required for their disposal. The objective was to investigate the potential of Z. marina residues as a source of secondary metabolites and feedstock in order to propose alternative solutions to the landfill. The supercritical CO 2 extract had a total phenol value of 55.4 mg GAE/g extract and a radical scavenging capacity of 71.4%. Considering the raffinate phase, 3% higher hemicellulose content was reached after supercritical CO 2 treatment. Enzymatic hydrolysis revealed 31.45% and the yield of simultaneous saccharification and fermentation was 8.72% corresponding to a productivity of 0.273 kg/(m 3 h). An integrated process is proposed, where supercritical fluid extraction can act both as the main process to obtain solvent-free pharmaceutical compounds and a pretreatment method in order to loosen the lignin structure, thereby liberating some of the hemicellulose in the matrix.

Abstract Background Personal transportation in urban areas is characterised by different transportation technologies with significantly varying properties regarding usability, infrastructural requirements and environmental impacts. This characterisation motivates the objective evaluation of mobility solutions, based on different criteria. State of the art evaluations in the scientific literature mainly focus on one specific criterion at a time. The most common criteria investigated are found in energy demand or equivalent fuel consumption. Other parameters include the traffic space demand or mean velocity as a reference for the user-related criterion “travel time”. Since different modes of transport show various potentials in different criteria, an interesting point for scientific research is consideration of the different criteria in a more comprehensive evaluation approach. To address this issue, the aim of this study is to present a new approach for an objective evaluation and comparison of different transport technologies under consideration of pre-defined range of criteria and defined boundary conditions and requirements for personal mobility in cities. Besides technical-oriented aspects like driving range, transport capability and life cycle-related consumption of resources, additional factors influencing user-behaviour and traffic density are reflected. The evaluation method is presented, based on a generated exemplary data collection regarding technical and in-use characteristics of different modes of transport, mainly investigated in the city of Graz, Austria. Methods The study focuses on different means of transport, in particular walking, bicycling, the use of powered two-wheelers, passenger cars with different propulsion systems and public transport systems. It is based on the determination of selected criteria, considering ecologic, infrastructural and user-related aspects. With respect to ecologic criteria, the study considers resources and energy consumption as also the resulting CO2 equivalent emissions. The mean velocity and transport capacity are considered in the context of user-related criteria. Traffic space demand is an important and limited resource, especially in urban areas. The present study thus includes the determination and comparison of the relative traffic and parking space demands for the different modes of transport. The evaluation is based on a specifically developed evaluation methodology, considering weighted traffic performance indices, which are also proposed and discussed. Results Within the present study, a database providing specific mobility-related criteria and parameters has been generated, representing technical characteristics and the effects of the use of different vehicles and means of transportation in urban areas. The illustrated results allow an objective evaluation of a broad range of different means of transportation and vehicles, based on introduced “weighted traffic performance indices” (WTPI). Conclusions The study contributes to a discussion of transportation technologies and allows a derivation of measures for further research topics to face future intra-urban mobility demands. This represents a basis for decision making on the priorisation of the most suitable transport systems for urban areas. It is shown that the motorised individual passenger transport as dominated by the use of private passenger cars in particular represents today the most inefficient form of inner-urban mobility.