Reducing fishing vessel fuel consumption and NOX emissions

There is a growing concern with the impact of marine operations on the environment. This requires reducing fuel consumption and vessel pollution during operation. On-board computers and satellite communications will enable the operator to reduce fuel consumption and NO_X emissions during vessel operations.This paper presents the results of a study on this problem and how such an on-board system could be implemented to reduce fuel consumption and engine NO_X emissions.     

Environmental analysis of the Norwegian fishery and aquaculture industry—A preliminary study focusing on farmed salmon

This article addresses the present status of seafood-oriented environmental methods and analyses, and pinpoints areas for further development. A recent study of the CO₂ emissions associated with the production of farmed salmon in Norway, following the life cycle from hatching to consumption, is presented. The study was initiated due to the increased focus on environmental impacts from food production among consumer organizations, retailers, and authorities. In general, several methods are being currently applied to measure environmental performance. Unfortunately, different methods provide quite different results. An additional challenge is that most of these methods were originally developed for land-based production. If assumptions about the performance of the seafood industry are established on the basis of incorrect information, consequences for both the management and the market level may not be desirable.     

Satellite monitoring of trace gas and aerosol emissions during wildfires in Russia

Peculiarities of the formation of carbon gas and fine aerosol emissions into the atmosphere during wildfires are analyzed. A prompt satellite monitoring system and technique for the assessment of burnt areas and volumes of CO₂, CO, and PM_2.5 emissions from wildfires are described. The results of satellite monitoring of the Russian Federation and some Russian regions for different months over 2010–2014 are given; burnt areas and volumes of carbon gas and aerosol emissions throughout the entire territory are assessed. The peculiarities of seasonal frequencies of wildfires and volumes of hazardous gas and fine aerosol emissions in the regions under study are identified.     

Estimation of multiyear changes in nitrogen oxide emissions in megalopolises from satellite measurements

The influence that megalopolises have on the atmospheric composition on regional and global scales is the subject of intense investigations; however, data on the emissions of pollutants used for such investigations are often insufficiently reliable. In this work the possibilities for diagnosing long-term changes in nitrogen oxide emissions in megalopolises are investigated based on a combined use of data from satellite measurements and modeling of the tropospheric nitrogen dioxide content. Primary emphasis is placed on analyzing possible situations when emission changes are of a nonlinear character. The proposed methodology includes an original method for the nonlinear approximation of changes in a physical quantity from a noised time series of its measurements. Changes in NO _x emissions are investigated in 12 megalopolises of Europe and the Middle East in the period from 1996 to 2008. Statistically significant changes in NO _x emissions are detected in five megalopolises (Baghdad, Madrid, Milan, Moscow, and Paris). By using three megalopolises (Madrid, Milan, and Paris) as an example, it is shown that a nonlinear approximation of NO _x emission changes agrees better with independent ground-based measurements than an analogous linear approximation.     

Abatement of air pollution at an aegean island port utilizing shore side electricity and renewable energy

The air pollutant emissions of the ships at port represent a small percentage of the overall emissions from shipping however they are concentrated in a small area. In Mytilene, Lesvos, the port is located within the city limits, resulting in air pollution, congestion and noise, especially during the tourist season. The aim of this study is to estimate the quantities of particulate matter and CO₂ emitted by ships in the port of Mytilene and to explore the potential of shore side electricity to reduce the emissions. The emissions were estimated using the bottom–up methodology, based on the activity of the ships in the port (berthing, maneuvering). Simulation of renewable energy sources was made using Homer Energy microgrid simulation software. The results showed that between the 10th and 20th of August 2012, there were 40 calls of passenger ships, tankers and bulk carriers in the port of Mytilene, emitting 441 kg of PM₁₀ and 282 metric tonnes of CO2. About 63% of PM₁₀ and 77% of CO₂ were emitted at the berthing phase and the remaining during the maneuvering. These emissions could be reduced by providing electricity to the ships from a hybrid renewable energy system with wind turbines and photovoltaics, connected to the grid. Simulations showed that the total energy requirements of the ships in the port of Mytilene could be covered by four 1.5 MW wind turbines combined with a 5 MW photovoltaics. With this configuration, renewable energy will exceed the ships' electricity needs for most of the time in order not to increase the power station's load. The excess energy could be fed to the islands' grid, so a costly battery storage system is not necessary to handle the variations of alternative energy. In this way, a considerable reduction of the CO₂ and PM₁₀ emissions by the ships in the port occurs, providing a viable solution for a cleaner and healthier environment.     

The density functional calculations on the structural and electronic properties of the endohedral fullerene dimer (N2@C60)2

The generalised gradient approximation based on density functional theory is used to study the structural and electronic properties of the endohedral fullerene dimer (N₂@C₆₀)₂. Four N atoms sit at the cage centres in the form of two N_2 molecules. The density of states and Mulliken charge analysis explore that the energy levels from -6 to -10 eV are mainly influenced by the N₂ molecules.     

From reductionism to systems thinking: How the shipping sector can address sulphur regulation and tackle climate change

The shipping sector is required to reduce fuel sulphur content to 0.1% in Emission Control Areas by 2015 and to 0.5% globally by 2020. Although this is demanding, a greater challenge for all sectors is climate change. However, the three options to comply with sulphur regulation do little to address this challenge. With a deep-seated change to the type of fuel burnt in marine engines, this should be seen as an opportunity to explore co-benefits of sulphur and carbon reduction – instead of taking a short-sighted approach to the problem. It is argued here that the upcoming sulphur regulations should be postponed and instead, a co-ordinated suite of regulations should be implemented that tackles cumulative CO₂ emissions and localised SO_x emissions in chorus. This would ensure that less developed, yet more radical, step-change forms of propulsion such as wind, battery and biofuels are introduced from the outset – reducing the risks of infrastructure lock-in and preventing the lock-out of technologies that can meaningfully reduce absolute emissions from the sector.     

相变存储材料Ge1Sb2Te4和Ge2Sb2Te5薄膜的结构和电学特性研究

采用射频磁控溅射方法制备了两种用于相变存储器的Ge₁Sb₂Te₄和Ge₂Sb₂Te₅相变薄膜材料,对其结构、电学输运性质和恒温下电阻随时间的变化关系进行了比较和分析.X射线衍射(XRD)和原子力显微镜(AFM)的结果表明:随着退火温度的升高,Ge₁Sb₂Te₄薄膜逐步晶化,由非晶态转变为多晶态,表面出现均匀的、     

Structures and magnetic behaviours of TiO2—Mn—TiO2 multilayers

The TiO₂--Mn--TiO₂ multilayers are successfully grown on glass and silicon substrates by alternately using radio frequency reactive magnetron sputtering and direct current magnetron sputtering. The structures and the magnetic behaviours of these films are characterised with x-ray diffraction, transmission electron microscope (TEM), vibrating sample magnetometer, and superconducting quantum interference device (SQUID). It is shown that the multi-film consists of a mixture of anatase and rutile TiO₂ with an embedded Mn nano-film. It is found that there are two turning points from ferromagnetic phase to antiferromagnetic phase. One is at 42 K attributed to interface coupling between ferromagnetic Mn₃O₄ and antiferromagnetic Mn₂O₃, and the other is at 97 K owing to the interface coupling between ferromagnetic Mn and antiferromagnetic MnO. The samples are shown to have ferromagnetic behaviours at room temperature from hysteresis in the M--H loops, and their ferromagnetism is found to vary with the thickness of Mn nano-film. Moreover, the Mn nano-film has a critical thickness of about 18.5 nm, which makes the coercivity of the multi-film reach a maximum of about 3.965times 10 ^{- 2} T.     

Biological Impact of Elevated Ocean CO<Subscript>2</Subscript> Concentrations: Lessons from Animal Physiology and Earth History

CO₂ currently accumulating in the atmosphere permeates into ocean surface layers, where it may impact on marine animals in addition to effects caused by global warming. At the same time, several countries are developing scenarios for the disposal of anthropogenic CO₂ in the worlds' oceans, especially the deep sea. Elevated CO₂ partial pressures (hypercapnia) will affect the physiology of water breathing animals, a phenomenon also considered in recent discussions of a role for CO₂ in mass extinction events in earth history. Our current knowledge of CO₂ effects ranges from effects of hypercapnia on acid-base regulation, calcification and growth to influences on respiration, energy turnover and mode of metabolism. The present paper attempts to evaluate critical processes and the thresholds beyond which these effects may become detrimental. CO₂ elicits acidosis not only in the water, but also in tissues and body fluids. Despite compensatory accumulation of bicarbonate, acid-base parameters (pH, bicarbonate and CO₂ levels) and ion levels reach new steady-state values, with specific, long-term effects on metabolic functions. Even though such processes may not be detrimental, they are expected to affect long-term growth and reproduction and may thus be harmful at population and species levels. Sensitivity is maximal in ommastrephid squid, which are characterized by a high metabolic rate and extremely pH-sensitive blood oxygen transport. Acute sensitivity is interpreted to be less in fish with intracellular blood pigments and higher capacities to compensate for CO₂ induced acid-base disturbances than invertebrates. Virtually nothing is known about the degree to which deep-sea fishes are affected by short or long term hypercapnia. Sensitivity to CO₂ is hypothesized to be related to the organizational level of an animal, its energy requirements and mode of life. Long-term effects expected at population and species levels are in line with recent considerations of a detrimental role of CO₂ during mass extinctions in the earth's history. Future research is needed in this area to evaluate critical effects of the various CO₂ disposal scenarios. This revised version was published online in July 2006 with corrections to the Cover Date.     

Sb2 Te3 纳米结构的制备与表征

以室温热电性能优异的传统热电材料Sb₂Te₃为研究对象,利用化学气相沉积法制备Sb₂Te₃单晶纳米结构,并研究其生长机理.实验结果表明,不加催化剂时Sb₂Te₃易生长成六方纳米盘,在金催化剂条件下定向生长成纳米线.Sb₂Te₃的形貌与其晶体结构和生长机理有关.Sb₂Te₃为三角结构,Sb和     

Si2O2 molecule: structure of ground state and the excited properties under different external electric fields

Geometry and vibrational frequencies of the ground state of Si₂O₂ molecule are studied using density function theory (DFT) at the level of cc-pvtz and 6-311++G^**. It is found that the optimizing value by B3lyp/cc-pvtz is closer to the experimental data. The excited properties under different external electric fields are also investigated by the time-dependent-DFT method. Transitions from the ground state of Si₂O₂ molecule to the first singlet state under different external electric fields can take place more easily. The corresponding absorption spectral line is about 360 nm in wavelength and the excitation energy is about 3.4 eV.     

Carbonate chemistry and projected future changes in pH and CaCO3 saturation state of the South China Sea

To study the dissolved carbonate system in the South China Sea (SCS) and to understand the water mass exchange between the SCS and the West Philippine Sea (WPS), pH, total alkalinity and total CO₂ were measured aboard the R/V Ocean Researcher 1. Because of the sill that separates these two seas in the Luzon Strait with a maximum depth of 2200 m, the SCS Deep Water has characteristics similar to those of water at about 2200 m in the WPS. The minimum pH and the maxima of normalized alkalinity and total CO₂ commonly found in the open oceans at mid-depth also prevail in the WPS but are, however, very weak in the SCS. Rivers and inflows from Kuroshio Surface and Deep Waters through the Luzon Strait as well as those through the Mindoro Strait transport carbon to the SCS year-round. Meanwhile, the outflowing Taiwan Strait water as well as the SCS Surface and Intermediate Waters of the Luzon Strait transports carbon out of the SCS year-round. The Sunda Shelf is also a channel for carbon transport into the SCS in the wet season and out of the SCS in the dry season.fCO₂ data and mass balance calculations indicate that the SCS is a weak CO₂ source in the wet season but an even weaker CO₂ sink in the dry season. With these facts taken together, the SCS is likely a very weak CO₂ source. Anthropogenic CO₂ penetrates to about 1500 m in depth in the SCS, and the entire SCS contains 0.60 ± 0.15 × 10¹⁵ g of excess carbon. Typical profiles of pH as well as the degree of saturation of each of calcite and aragonite in 1850 and 1997 are presented, and those for 2050 AD are projected. The maximum decrease in pH is estimated to be 0.16 pH units in the surface layer when the amount of CO₂ is doubled. It is anticipated that aragonite in the upper continental slope will likely start to dissolve, thereby neutralizing excess CO₂ by around 2050 AD. This paper is unique in that it presents the results of the first attempt ever to estimate the past, present and future physico-chemical properties of the world's largest marginal sea.     

Influence of Introduced CO<Subscript>2</Subscript> on Deep-Sea Metazoan Meiofauna

An experiment was performed to determine the effect of injected CO₂ on the deep-sea (3200 m) meiofaunal community in the Monterey Canyon. Approximately 20 L of liquid CO₂ was added to each of three cylindrical corrals (PVC rings pushed into the seabed) that were arranged in a triangular array 10 m on a side. After a 30-day period, sediment cores were collected within an area exposed to the dissolution plume emanating from the CO₂ pools and from a reference site approximately 40 m away; cores were also collected from within two of the CO₂ corrals. Sediment cores were sectioned into 0–5, 5–10, and 10–20 mm layers. Abundances of major groups (harpacticoid copepods, nematodes, nauplii, kinorhynchs, polychaetes, and total meiofauna) were determined for each layer. CO₂ exposure did not significantly influence the abundances or vertical distributions of any of the major taxa. However, other evidence suggests that abundance alone did not accurately reflect the effect of CO₂ on meiofauna. We argue that slow decomposition rates of meiofaunal carcasses can mask adverse effects of CO₂ and that longer experiments and/or careful examination of meiofaunal condition are needed to accurately evaluate CO₂ effects on deep-sea meiofaunal communities. This revised version was published online in July 2006 with corrections to the Cover Date.     

An improved model for the calculation of CO2 solubility in aqueous solutions containing Na, K, Ca, Mg, Cl, and SO4

An improved model is presented for the calculation of the solubility of carbon dioxide in aqueous solutions containing Na⁺, K⁺, Ca²⁺, Mg²⁺, Cl⁻, and SO₄²⁻ in a wide temperature–pressure–ionic strength range (from 273 to 533 K, from 0 to 2000 bar, and from 0 to 4.5 molality of salts) with experimental accuracy. The improvements over the previous model [Duan, Z. and Sun, R., 2003. An improved model calculating CO₂ solubility in pure water and aqueous NaCl solutions from 273 to 533K and from 0 to 2000 bar. Chemical Geology, 193: 257–271] include: (1) By developing a non-iterative equation to replace the original equation of state in the calculation of CO₂ fugacity coefficients, the new model is at least twenty times computationally faster and can be easily adapted to numerical reaction-flow simulator for such applications as CO₂ sequestration and (2) By fitting to the new solubility data, the new model improved the accuracy below 288 K from 6% to about 3% of uncertainty but still retains the high accuracy of the original model above 288 K. We comprehensively evaluate all experimental CO₂ solubility data. Compared with these data, this model not only reproduces all the reliable data used for the parameterization but also predicts the data that were not used in the parameterization. In order to facilitate the application to CO₂ sequestration, we also predicted CO₂ solubility in seawater at two-phase coexistence (vapor–liquid or liquid–liquid) and at three-phase coexistence (CO₂ hydrate–liquid water–vapor CO₂ [or liquid CO₂]). The improved model is programmed and can be downloaded from the website http://www.geochem-model.org/programs.htm.     

淡水和海水环境下沉积物搬运过程碳释放通量的模拟研究

基于室内物理模拟实验, 对长江沉积物进行淡水和海水环境下沉积物搬运过程碳释放通量实验模拟。结果表明, 模拟实验初期, 淡水和海水均为大气CO₂的源, 但淡水CO₂释放通量略高于海水;淡水、海水两种环境下, CH₄释放通量均较小, 为弱释放-弱吸收过程。对两种环境下碳通量对比研究发现,Eh 值可能是造成淡水和海水环境下CO₂通量差别的主要原因, 而pH 值可能对CO₂通量差别的影响较小。两种环境下温室气体通量差别的具体原因仍需进一步研究。通过模拟对比试验, 旨在为系统地认识长江流域水库的温室效应与减排提供科学依据, 为我国清洁水电能源发展提供理论参考。     

Carbonate-related parameters of subsurface waters in the West Philippine, South China and Sulu Seas

Like most other deep basins in Southeast Asia, the deep Sulu Sea (SS) basin is isolated from the neighboring seas by surrounding topography. While the near-surface circulation is mainly governed by the seasonally reversing monsoon winds, below the warm and fresh surface layer, the core of the incoming Subtropical Lower Water from the West Philippine Sea (WPS), by way of the South China Sea (SCS), can be seen, at a depth of around 200 m, to have a distinct salinity maximum. It lies well above the sill depth (420 m) in the Mindoro Strait and thus, its spreading is not hampered by topography. The deep circulation is forced by an inflow of upper North Pacific Intermediate Water (NPIW) from the SCS through the Mindoro Str. Below 1000 m, the physico-chemical properties are remarkably homogeneous. The higher temperature, but lower salinity, oxygen and nutrients, of the deep SS waters, compared to those of the SCS, is indicative of the intrusion of NPIW above the sill depth. The excess, anthropogenic CO₂ penetrates the entire water column, because of the over-spill of the excess CO₂-laden water from the SCS.It has been reported that the bottom of the SS is CaCO₃ rich, relative to the SCS. Previous investigators attribute this to the higher θ in the SS. Indeed, the aragonite does not become undersaturated in the SS until below 1400 m, compared to 600 m in both the WPS and SCS; and the calcite does not become undersaturated until below 3800 m in the SS, compared to 2500 m in the SCS and around 1600 m in the WPS. However, the temperature effect is relatively small. These large differences are, in fact, largely a result of higher CO₃²⁻ concentrations in the SS, relative to the WPS and SCS. The higher CO₃²⁻ concentration in the SS, in turn, is mainly caused by the smaller amounts of organic carbon decomposition.     

Seasonal Study of Methane and Nitrous Oxide in the Coastal Waters of the Southern Baltic Sea

Atmospheric and dissolved methane (CH₄) and nitrous oxide (N₂O) were measured in the unique coastal ecosystem of theBoddenwaters, including the western Oder estuary, (southern Baltic Sea) during five campaigns between 1994 and 1997. The CH₄saturations, ranging from 105–15 500%, showed great spatial and temporal variability with maximum values in September and minimum values in December. The N₂O saturations were in the range of 91–312% with a maximum in March. Enhanced concentrations of both gases were observed only in the western Oder estuary near the mouth of the Peene River. Thus, we conclude that the distributions of CH₄and N₂O in the investigatedBoddenwaters are, directly or indirectly, linked to the Peene River runoff and not to the Oder River. Our estimate of the annual CH₄emissions from theBoddenwaters to the atmosphere indicates a significant contribution (c. 17%) to the overall CH₄emissions from the Baltic Sea. In contrast, theBoddenwaters represent only a small source for atmospheric N₂O.CH₄production rates estimated from sediment slurry experiments revealed a significant spatial variability and indicated that methanogenic activity was related to acetate consumption in the surface sediment layer. Sedimentary CH₄production might depend on different amounts of accumulation of organic material.     

Magnetostriction of Fe81Ga19 oriented crystals

The effect of the orientation on the magnetostriction in Fe₈₁Ga₁₉ alloy has been investigated experimentally and theoretically. The Fe₈₁Ga₁₉ [001] and [110] oriented crystals were prepared and the magnetostriction was measured under different pre-stress. The saturation magnetostriction of the [001] oriented crystal increases from 170×10^-6 to 330×10^-6 under the pre-stress from 0 to 50 MPa. The [110] oriented crystal has a saturation magnetostriction from 20×10^-6 to 140×10^-6 with the compressive pre-stress from 0 to 40 MPa. The magnetostriction of [001] and [110] oriented crystals has been simulated based on the phenomenological theory. The domain rotation path has been determined and the resultant magnetostriction calculated under different pre-stress. The experimental and simulated results both show that the [001] oriented crystal exhibits better magnetostriction than [110] oriented crystal. The enhancement of the saturation magnetostriction by the compressive pre-stress in the [110] oriented crystal is higher than that in the [001] oriented crystal.