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A mesocosm approach was used to investigate the effects of ocean acidification (OA) on a natural plankton community in coastal waters off Norway by manipulating CO2 partial pressure (pCO2). Eight enclosures were deployed in the Raunefjord near Bergen. Treatment levels were ambient (~320 µatm) and elevated pCO2 (~2000 µatm), each in 4 replicate enclosures. The experiment lasted for 53 d in May-June 2015. To assess impacts of OA on the plankton community, phytoplankton and protozooplankton biomass and total seston fatty acid content were analyzed. In both treatments, the plankton community was dominated by the dinoflagellate Ceratium longipes. In the elevated pCO2 treatment, however, biomass of this species as well as that of other dinoflagellates was strongly negatively affected. At the end of the experiment, total dinoflagellate biomass was 4-fold higher in the control group than under elevated pCO2 conditions. In a size comparison of C. longipes, cell size in the high pCO2 treatment was significantly larger. The ratio of polyunsaturated fatty acids to saturated fatty acids of seston decreased at high pCO2. In particular, the concentration of docosahexaenoic acid (C 22:6n3c), essential for development and reproduction of metazoans, was less than half at high pCO2 compared to ambient pCO2. Thus, elevated pCO2 led to a deterioration in the quality and quantity of food in a natural plankton community, with potential consequences for the transfer of matter and energy to higher trophic levels

Lithium ion batteries are increasingly used in electrical energy storage systems despite their thermal and chemical hazards on failure. These hazards are magnified when multiple cells are combined together in a pack because of the risk of cascading failure. An experimental setup was utilized to investigate the dynamics, gaseous emissions, and energetics associated with thermal failure of cylindrical 18650 form factor, 2600 mAh, lithium cobalt oxide cathode cell arrays in an inert atmosphere. Cell state of charge (SOC) and arrangement were altered to investigate mitigation strategies and provide recommendations for safer battery pack design, transportation, and storage. Complete failure propagation was not prevented in any test, but decreasing to 50% SOC did result in propagation speeds 8.5 times slower than at 100% SOC. Introducing a 5 mm gap between cell rows also slowed propagation somewhat, but to a lesser degree than lowering SOC. Maximum temperatures, hazardous gas yields, and chemical heat generation were all reduced for cells at 50% SOC compared with 100% SOC, but introducing 5 mm gaps had little impact on these quantities. Limiting cells to 50% SOC was by far the most effective mitigation strategy tested, but no strategy was able to eliminate the failure propagation risk. Installing battery packs in inert environments, limiting SOC, and instituting gaps between certain cells can all be effective strategies to lessen the severity of cascading failure, but none of these strategies are individually sufficient for safe transportation and storage of battery packs.

AbstractAimExperimental simulation of near‐future ocean acidification (OA) has been demonstrated to affect growth and development of echinoderm larval stages through energy allocation towards ion and pH compensatory processes. To date, it remains largely unknown how major pH regulatory systems and their energetics are affected by trans‐generational exposure to near‐future acidification levels.MethodsHere, we used the common sea star Asterias rubens in a reciprocal transplant experiment comprising different combinations of OA scenarios, to study trans‐generational plasticity using morphological and physiological endpoints.ResultsAcclimation of adults to pHT 7.2 (pCO2 3500 μatm) led to reductions in feeding rates, gonad weight and fecundity. No effects were evident at moderate acidification levels (pHT 7.4; pCO2 2000 μatm). Parental pre‐acclimation to pHT 7.2 for 85 days reduced developmental rates even when larvae were raised under moderate and high pH conditions, whereas pre‐acclimation to pHT 7.4 did not alter offspring performance. Microelectrode measurements and pharmacological inhibitor studies carried out on larval stages demonstrated that maintenance of alkaline gastric pH represents a substantial energy sink under acidified conditions that may contribute up to 30% to the total energy budget.ConclusionParental pre‐acclimation to acidification levels that are beyond the pH that is encountered by this population in its natural habitat (eg, pHT 7.2) negatively affected larval size and development, potentially through reduced energy transfer. Maintenance of alkaline gastric pH and reductions in maternal energy reserves probably constitute the main factors for a reduced juvenile recruitment of this marine keystone species under simulated OA.

This research evaluated the implementation of transit signal priority (TSP) on a test corridor along International Drive in Orlando, Florida, to see whether the implementation was successful and justified expansion to a regional implementation of TSP for bus tie-ins to the new regional SunRail commuter rail in Central Florida. TSP is a technology that provides preferential treatment to buses at signalized intersections. This research demonstrated the effectiveness of TSP in improving bus corridor travel time in a simulated environment by using real-world data for the International Drive corridor. Evaluation was conducted with microsimulation to compare unconditional and conditional TSP with the no TSP scenario. This evaluation looked at performance metrics (for buses and all vehicles), including average speed profiles, average travel times, average number of stops, and crossing street delay. Different conditional TSP scenarios of activating TSP when a bus is 3 or 5 min behind schedule were considered. The simulation demonstrated that conditional TSP significantly improved bus travel times with little effect on crossing street delays. Unconditional TSP resulted in significant crossing street delays at some intersections with only minor improvement to bus travel time compared with both conditional TSP scenarios. The results also showed that using TSP technology reduced the environmental emissions in the International Drive corridor. With a benefit–cost ratio of 7.92 in the International Drive corridor, conditional TSP 3 min behind schedule was determined to be the most beneficial and practical TSP scenario for real-world implementation at corridor and regional levels.

Si3N4 is widely used in the semiconductor industry as a sacrificial etch stop layer, implantation spacers, hard mask for selective epitaxy. Si3N4 is resistant to many RIE process, to fluoridric acid, and can be easily removed thanks to hot phosphoric acid with excellent selectivity to other materials (Si and SiO2). However hot phosphoric process presents majors drawbacks: Done in wet benches, the levels of metallic and particular contamination, process uniformity, do not match all the requirements of 14nm node and beyond. Surface preparation standards indeed converge towards single wafer cleans for these reasons. But typical etch rate with hot phosphoric are too low (>1Å/min) to be compatible with a single wafer approach. Plasma removal is a possible alternative, either by RIE or CDE (Chemical Downstream Etching). If the selectivity to the SiO2is usually very low for RIE (~15), selectivity for CDE reactors up to 60 have been reported in the last years, increasing the interest for this technique. In the present work we evaluated the etching selectivity of a new CDE process. We achieved successfully its integration in replacement of hot phosphoric acid for a process step denoted as nitride pull back (NPB): In VLSI circuits, transistors are electrically insulated by trenches filled with SiO2. As the filling is done by conformal deposition methods, it is greatly facilitated by an etch back of the top Si3N4 (fig.1). One problem in this case is that CDE used here could etch the silicon in the trench very quickly: this disadvantage has been overcome by oxidizing the flanks of the trench with a RTP process. In this configuration, a SiO2 liner is formed at the surface of the trench. However RTP process is known to create also an oxidized layer at the surface of the Si3N4 that can delay the etching. In this context we evaluated the selectivity of the process on full sheet layers. For that purpose we generated SiN layers made by LPCVD furnace at 770°C, and thermal SIO2 made by RTP. Top of the Si3N4layers were also oxidized to evaluate the etching delay induced by this surface oxidation. Fig2. reports the Si3N4 and SiO2 etch rates vs. etching time. Si3N4 removal rate is very stable around 150 Å/min. In the same time SiO2 etch rate increases moderately form 0.6 to 1.6 Å/min. As a result, the average selectivity is always higher than 100:1 and reaches 250:1 at the early stage of the process. If oxidized, an etch delay is induced and Si3N4 etch rates and selectivity to SIO2 drops rapidly with the oxidation budget (fig.3): Thus a moderate oxidation has been done on the patterned wafer to preserve both Si3N4 etch rate and the liner integrity. Thickness measurements returned a Si3N4 removal of 120Å with a good within wafer uniformity (3.5%), and a negligible SIO2 removal (<0.1Å). TEM cross sections (Fig.4) confirmed that the oxide liner and underlying silicon are preserved during the Si3N4 etching. Differences of etch rates between dense and isolated areas have been evaluated as far as the defectivity aspects and will be discussed in the full paper.

Abstract Electric mobility is a trending topic around the world, and many countries are supporting electric vehicle technologies to reduce environmental impacts from transportation such as greenhouse gas emissions and air pollution in cities. While such environmental impacts are widely studied in the literature, there is not much emphasis on a comprehensive sustainability assessment of these vehicle technologies, encompassing the three pillars of sustainability as the environment, society, and economy. In this study, we presented a novel comprehensive life cycle sustainability assessment for four different support utility electric vehicle technologies, including hybrid, plug-in hybrid, and full battery electric vehicles. A hybrid multi-regional input-output based life cycle sustainability assessment model is developed to quantify fourteen sustainability indicators representing the three pillars of sustainability. As a case study, we studied the impacts for Qatar, a country where 100% of electricity generation is from natural gas and have a very unique supply-chain, mainly due to a wide range of exported products and services. The analysis results showed that all-electric vehicle types have significant potential to lower global warming potential, air pollution, and photochemical oxidant formation. A great majority (above 90%) of the emissions occurs within the region boundaries of Qatar. In the social indicators, internal combustion vehicles performed better than all other electric vehicles in terms of employment generation, compensation of employees, and taxes. The results highlighted that adoption of electric vehicle alternatives doesn't favor macro-economic indicators and they have slightly less for a life-cycle cost. The proposed assessment methodology can be useful for a comprehensive regionalized life cycle sustainability assessment of alternative vehicle technologies and developing regionalized sustainable transportation policies worldwide.

This article joins recent calls for greater attention to be paid to the politics of mobility. In particular, it examines how air transport is not only experienced inequitably among different social groups, but is also an activity whose access and opportunities are geographically distributed in uneven ways. Using Singapore as a candidate and foil to reflect on this issue, this paper interrogates how three ‘international’ legislative frameworks—air traffic rights, air navigation rules, and climate change initiatives—have variously limited the city-state’s potential to ‘move’ at different stages of its flying career. Despite the city-state’s widely-acclaimed aviation success, this paper demonstrates how it remains subject to the geopolitical actions of more dominant players, residing interstitially between being at the vanguard, and at the peripheries of global air traffic. It is suggested that further interrogations on how particular transport practices and configurations become salient in the world are needed.

To limit or, even better, reduce the emission of CO2 and the corresponding global warming effects, measures should be taken in the two most polluting economic sectors: the energy and transport sectors. The Netherlands has set goals to reduce CO2 emissions, in line with global and European initiatives. To reach this target, the electricity production sector should also use more renewables and the transport sector should take measures. In the electricity sector, the Netherlands wants to realize 10 GW of installed wind power in 2020; one of the initiatives for the transport sector is to have one million EVs (electric vehicles) in the same year. When EVs are powered with electricity from renewable sources, both sectors benefit: as such, we can 'kill two birds with one stone'. To study this, we researched the possible effects on the electricity system when introducing a large number of EVs and an increasing amount of wind power. The research presented models this for the 2020 Dutch situation. The study shows that the 2020 electricity system can cope with one million EVs and 10 GW of wind power, provided that EVs are charged using a load management regime that levels the nightly electricity demand. (C) 2012 Elsevier Ltd. All rights reserved.