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1.
Amitrajeet A. Batabyal Peter Nijkamp 《Stochastic Environmental Research and Risk Assessment (SERRA)》2005,19(5):340-347
We study the problem of precluding biological invasions caused by ships transporting internationally traded goods in containers between different regions of the world. Using the long run expected net cost (LRENC) of inspections as the apposite managerial objective, we address the following important question: given that inspection is a cyclical activity, is the LRENC lower when a port manager’s inspector inspects cargo upon the arrival of a specified number of containers (container policy) or is this LRENC lower when this inspector inspects cargo at fixed points in time (temporal policy)? We construct a queuing theoretic model and show that in an inspection cycle, irrespective of whether the inspection policy choice is made on the basis of an explicit optimization exercise or on the basis of rules of thumb, the container policy is superior to the temporal policy because the container policy results in lower LRENC from inspection activities. 相似文献
2.
Amitrajeet A. Batabyal 《Stochastic Environmental Research and Risk Assessment (SERRA)》2007,21(6):717-727
We propose a research agenda for studying six basic questions about the impacts of alternate international invasive species control mechanisms on economic agents in a nation such as the USA. The six questions are as follows. First, when can one justify a trade ban as an effective regulatory policy? Second, what are the properties of control rules that vary by port of entry and whether a shipment is viewed as a routine or as a first-time entry? Third, when should a port manager in the USA use information about the dollar value of the products being transported by ships from two exporting firms and the expected time it takes to inspect ships from these two firms to grant preferential treatment to one or the other firm? Fourth, what are some reasonable measures of the trade related risk from invasive species? Fifth, how useful is strategic trade policy as an invasive species management tool? Finally, when analyzing a biological invasion, is it more appropriate to focus on the likelihood of this event or, instead, on the magnitude of the event? 相似文献
3.
In examining ship-mediated biological invasions, most research and treatment development has focused on ballast water. Another vector that has gained attention recently is vessels arriving in a "no ballast on board" (NOBOB) condition. Such ships retain relatively small, unpumpable volumes of water and sediment in their ballast tanks. Nonetheless, these unpumpable portions can represent great ecological risk. This scenario is relevant in the Great Lakes, which have experienced a dramatic series of introductions, despite most vessels arriving there as NOBOBs since 1994. We examined shipping patterns of NOBOBs arriving to lower Chesapeake Bay to begin evaluating their risk of biopollution. Only 14% of ships arrive as NOBOBs, and of those, 17% depart to another port in the upper bay. Most NOBOBs arrive from or leave for other US ports; proximate trans-Atlantic crossings are few. Given the nature of their operations, we conclude NOBOBs may represent a risk for aquatic nuisance species invasions to Chesapeake Bay. 相似文献
4.
The use of the deposit-refund framework in port reception facilities charging systems 总被引：1，自引：0，他引：1
Georgakellos DA 《Marine pollution bulletin》2007,54(5):508-520
The European Union set in place Directive 2000/59/EC with the aim of substantially reducing discharges of ship-generated waste into the sea by improving the availability and use of port reception facilities. According to the Directive, port administrations shall ensure that the cost recovery system must aim to discourage ships from discharging their waste into the sea, while simultaneously placing the burden of costs on ships, in line with the "polluter pays principle". The present paper examines the extent to which the deposit-refund framework could be used in charging systems of port reception facilities. This has been realized through a case study involving a Greek port. Specifically, the charging system proposed here seems to approach quite close to the primary target, i.e. to a charging system that motivates ships to act more environmentally responsible manner regarding their waste, without significantly affecting their total cost nor the competitiveness of the port. 相似文献
5.
《Marine pollution bulletin》2014,85(1-2):330-338
Ballast water exchange (BWE) is the most efficient measure to control the invasion of exotic species from ships. This procedure is being used for merchant ships in national and international voyages. The ballast water (BW) salinity is the main parameter to evaluate the efficacy of the mid-ocean ballast water exchange. The vessels must report to the Port State Control (PSC), via ballast water report (BWR), where and how the mid-ocean BWE was performed. This measure allows the PSC to analyze this information before the ship arrives at the port, and to decide whether or not it should berth.Ship BW reporting forms were collected from the Captaincy of Santana and some ships were visited near the Port of Santana, located in Macapá (Amazon River), to evaluate the BW quality onboard. We evaluated data submitted in these BWR forms and concluded that the BWE efficacy might be compromised, because data contained in these BWR indicate that some ships did not change their BW. We found mistakes in filling the BWR forms and lack of information. Moreover, these ships had discharged BW with high level of salinity, Escherichia coli and total coliforms into the Amazon River. We concluded that the authorities of the Amazon Region need to develop more efficient proceedings to evaluate the ballast water reporting forms and BW quality, as there is potential risk of future invasion of exotic species in Brazilian ports. 相似文献
6.
The Barents Sea has one of the highest levels of biological production of all the world's oceans, and holds some of the largest fish stocks and concentrations of seabirds. Environmental conditions in the area make it particularly vulnerable to damage from human activities. Given the vulnerability of this ecosystem to the effects of human activity, and the fact that physical factors (e.g. reduced visibility, ice) increase risks due to oil exploitation and shipping activities, environmental authorities will work towards more stringent discharge limits and higher standards for emergency preparedness for both oil exploitation and shipping in the Barents Sea. The Norwegian Pollution Control Authority gives priority to preventive measures that can lower the probability of accidents and particular emphasis will be given to conditions attached to production licences and controls on activities in areas that have not yet been opened for petroleum activities. Within the Arctic Environmental Protection Strategy (the Rovaniemi-process), Norway has proposed that efforts should be made to improve the protection of Arctic marine areas, and further that a working group including representatives of all the Arctic countries should assess various legal instruments and possible measures, and make recommendations for action. Currently, no special international requirements apply to ships sailing in ice-infested waters, and the recommendations from the working group will therefore be of great importance in protecting the area from damage from shipping. 相似文献
7.
Because of its geographic and economic position, the Western part of Europe and France is prone to biological invasions. Among the aquatic species non-native to France, a high proportion of these species are considered to be salt-tolerant. To verify this assumption, we compared the salinity tolerance of 18 native and non-native species in France in order to determine whether the introduced non-native species are more salt-tolerant than the native ones. Contrary to our expectations, our study shows that both native and non-native macroinvertebrate species from the same taxonomic group which had originated from within Eurasia had very similar salinity tolerance. Our results show that species originate from outside Eurasia (introduced by the ballast or drinking water on ships) were more salt tolerant than native from France and non-native species originated from Eurasia. Thus, derivation of the acute test of the salinity tolerance in native ranges may give good indications of their potential ability to survive during the translocation by shipping from the area of origin to another area. Our approach does provide empirical evidence for potential of non-native species to survive translocation in saline water using standard, quick and inexpensive protocols. 相似文献
8.
Ships are a dominant vector for biological invasions through ballast water discharge (BWD) and hull fouling. Here, we provide a first comprehensive analysis of shipping in Alaska, summarizing (a) the number, type and origin of vessel arrivals to Alaska for 2003 and 2004, (b) the spatial and temporal variation in vessel traffic, and (c) the available data on ballast water discharge in order to prioritize locations for tracking biological invasions. Most arrivals were passenger vessels, followed by ferries and fishing vessels, all of which carried little ballast water. Regional and seasonal patterns in arrivals and BWD were unevenly distributed among vessel types. The majority of vessels reporting BWD were from foreign ports, and most of this ballast was untreated. The largest volumes of ballast were from tankers at Valdez and Kenai Peninsula ports. Although Alaska has few documented invasions, opportunities for ship-mediated transfer now appear high and warrant further scrutiny. 相似文献
9.
Since the 1960s tributyl (TBT)-based antifouling paints are widely applied to protect ship’s hulls from biofouling. Due to its high toxicity to aquatic ecosystem most of the countries (28 nations in 2008) signed the AFS convention to control the use of harmful antifouling systems on ships. Nevertheless there is currently no simple method to control the presence of organotin in paint. In this study, we propose a bioassay based on the use of a recombinant bioluminescent bacteria to detect directly in paint the presence of TBT. We also propose a simple device as an inspection system to control the absence of organotin in the ship’s hull paint. The presence of organotin could be revealed in less than three hours. 相似文献
10.
摇枕、侧架作为列车转向架的重要组成部分,对列车行驶安全起到至关重要的作用,各生产厂家亟须具有高穿透力的检测设备对其进行大批量的检测.本文介绍了应用于铁路机车关键部件无损检测的大型工业CT系统,论述了系统设计和扫描工作流程,并通过实例展示大型工业CT在摇枕、侧架等无损检测的应用情况.实际应用说明大型工业CT系统可对摇枕、侧架等关键部件的内部结构及内部的气孔、砂眼、夹杂物、缩孔、疏松、冷隔、裂纹等铸造缺陷进行快速有效检测,能够很好地满足该行业的需求. 相似文献
11.
This study investigated the potential for transport of organisms between Hobart, Macquarie Island and the Antarctic continent by ships used in support of Antarctic science and tourism. Northward transport of plankton in ballast water is more likely than southward transport because ballast is normally loaded in the Antarctic and unloaded at the home port. Culturing of ballast water samples revealed that high-latitude hitchhikers were able to reach greater diversities when cultured at temperate thermal conditions than at typical Southern Ocean temperatures, suggesting the potential for establishment in the Tasmanian coastal environment. Several known invasive species were identified among fouling communities on the hulls of vessels that travel between Hobart and the Southern Ocean. Southward transport of hull fouling species is more likely than northward transport due to the accumulation of assemblages during the winter period spent in the home port of Hobart. This study does not prove that non-indigenous marine species have, or will be, transported and established as a consequence of Antarctic shipping but illustrates that the potential exists. Awareness of the potential risk and simple changes to operating procedures may reduce the chance of introductions in the future. 相似文献
12.
G. H. A. Cole 《Surveys in Geophysics》2006,27(3):365-382
If intelligent life were common in the Universe, should we not be aware of it on Earth through contact with advanced space ships and automatic probes? Would we not at least expect to intercept communication signals between space travellers? That this is not found has led to much speculation in the past. Recent discoveries of planets around other stars (called here exoplanets) and, separately, recent discoveries in the evolution of life on Earth, including Homo sapiens, allow this question to be considered again but now with more information than before. This is the subject of the present paper. The study involves aspects of physics and chemistry in combination with biological studies. It is concluded here that the places where technologically capable intelligent life might be expected to be found in our Galaxy are so few that any such “centres of civilisation” must be separated by large distances, probably in excess of 50 light years. If true, this would make the different centres essentially isolated and would suggest that each manifestation of advanced intelligent life is a purely local development. This would agree with our experience of aloneness. Nevertheless, the number of centres throughout the Universe would still be astronomically large, even if each galaxy had only one centre. An hypothesis is proposed which could account for the existence of such centres in this form. 相似文献
13.
X射线安全检查技术综述 总被引：15，自引：3，他引：12
近年来,X射线安全检查技术受到航空安全等需要的驱使,得到迅速发展.本文对国内外现有的用X射线探测行李中的爆炸物和其他违禁品的几个主要方法做了一个回顾,阐述了用单能法、双能法、双视角、散射、计算机断层成像法和立体匹配分层成像法进行物质识别的基本原理,并对各种方法的优缺点作了比较和讨论,最后对X射线安全检查技术的未来发展前景进行了展望. 相似文献
14.
Per H. Olson 《Marine pollution bulletin》1994,29(6-12):284-295
A present major problem for ports is arranging adequate reception facilities for ship-generated waste, as the lack of such facilities is a problem to many shipowners. To preserve the environment in and around the ports it is necessary also to deal efficiently with the port-generated waste.
Although international conventions on the retention of waste on board ships for subsequent discharge to shore reception facilities have been ratified by most seafaring nations, a considerable part of the ship-generated waste still goes into the sea. Much of the waste generated in ports will also be dumped in quantities that at least affect the local marine environment. The regulations governing the handling of port-generated waste are often national and/or local legislation, whereas the handling of ship-generated waste is governed by the MARPOL Convention in most parts of the world.
The handling of waste consists of two main phases—collection and treatment. Waste has to be collected in every port and on board every ship, whereas generally only some wastes are treated and to a certain degree in ports and on board ships.
This paper considers the different kinds of waste generated in both ports and on board ships, where and how it is generated, how it could be collected and treated. The two sources are treated together to show how some ship-generated waste may be treated in port installations primarily constructed for the treatment of the port-generated waste, making integrated use of the available treatment facilities.
The different types of wastes can be divided into different categories. A world-wide accepted categorization of ship-generated waste has been established in the MARPOL 73/78 Convention. This will also be used for grouping the port-generated waste. 相似文献
15.
当前航空安全形势紧张,所有国家都正在加强其安全检测系统.鉴于危险物品的特殊性,对含有危险物品的行李包的X射线图像进行模拟是一种有效培训安检人员的方式.这种模拟方式可以增强安检人员对不同背景环境下危险物品X射线特征的敏感度.在本文中,首先对X射线图像融合的物理过程进行了分析并且介绍了当前此领域中普遍使用的融合算法,随后采... 相似文献
16.
We study the effect of stratification and compressibility on the threshold of convection and the heat transfer by developed convection in the nonlinear regime in the presence of strong background rotation. We consider fluids both with constant thermal conductivity and constant thermal diffusivity. The fluid is confined between two horizontal planes with both boundaries being impermeable and stress-free. An asymptotic analysis is performed in the limits of weak compressibility of the medium and rapid rotation (τ?1/12???|θ|???1, where τ is the Taylor number and θ is the dimensionless temperature jump across the fluid layer). We find that the properties of compressible convection differ significantly in the two cases considered. Analytically, the correction to the characteristic Rayleigh number resulting from small compressibility of the medium is positive in the case of constant thermal conductivity of the fluid and negative for constant thermal diffusivity. These results are compared with numerical solutions for arbitrary stratification. Furthermore, by generalizing the nonlinear theory of Julien and Knobloch [Fully nonlinear three-dimensional convection in a rapidly rotating layer. Phys. Fluids 1999, 11, 1469–1483] to include the effects of compressibility, we study the Nusselt number in both cases. In the weakly nonlinear regime we report an increase of efficiency of the heat transfer with the compressibility for fluids with constant thermal diffusivity, whereas if the conductivity is constant, the heat transfer by a compressible medium is more efficient than in the Boussinesq case only if the specific heat ratio γ is larger than two. 相似文献
17.
The circulation in the shelf seas of Maritime Canada is predominantly in the northeast–southwest direction. Despite the mean northeast–southwest flow, a number of AIS invasions have been observed to proceed in the opposite direction – from the Gulf of Maine, around Nova Scotia, and into the southern Gulf of St. Lawrence. Flow fields from a numerical circulation model are used to investigate whether these invasions could be due to drift in ocean currents. Particle tracking experiments are performed and probability density functions (PDFs) derived that describe the probability of drifting a given upstream distance in a given drift time. Analysis of these PDFs revealed that for invasions that took 20–40 y to occur, propagule drift in ocean currents could be responsible for the upstream spread, while this was not the case for short timescale invasions (<10 y). Rafting could be responsible for both short and long timescale invasions. 相似文献
18.
Hassan Rashid Ali Marinah Mohd Arifin Mohammed Ali Sheikh Noor Azhar Mohamed Shazili Said Suleiman Bakari Zainudin Bachok 《Marine pollution bulletin》2014
The use of antifouling paints to the boats and ships is one among the threats facing coastal resources including coral reefs in recent decades. This study reports the current contamination status of diuron and its behaviour in the coastal waters of Malaysia. The maximum concentration of diuron was 285 ng/L detected at Johor port. All samples from Redang and Bidong coral reef islands were contaminated with diuron. Temporal variation showed relatively high concentrations but no significant difference (P > 0.05) during November and January (North-East monsoon) in Klang ports (North, South and West), while higher levels of diuron were detected during April, 2012 (Inter monsoon) in Kemaman, and Johor port. Although no site has shown concentration above maximum permissible concentration (430 ng/L) as restricted by the Dutch Authorities, however, long term exposure studies for environmental relevance levels of diuron around coastal areas should be given a priority in the future. 相似文献
19.
Mariano J. Albano Paulo da Cunha Lana Claudia Bremec Rodolfo Elías César C. Martins Natalia Venturini Pablo Muniz Silvia Rivero Eduardo A. Vallarino Sandra Obenat 《Marine pollution bulletin》2013
We evaluated benthic habitat quality along a presumed contamination gradient in the Mar del Plata port (Southwestern Atlantic) by coupling biological and chemical proxies in a multidisciplinary approach. Organic matter and photosynthetic pigment contents were higher in silty-clay bottoms of the inner port sites. Levels of all fecal steroids decreased from the inner sites to the port inlet. High concentrations of coprostanol in the inner sites seemed to derive from a permanent population of sea lions rather than from sewage outfalls due to coprostanol/epicoprostanol ratio (IV) values <2.5. PAHs levels were also higher in the inner sector, related to both biomass combustion and petroleum combustion associated to local marine traffic. High disturbance and low ecological status were reflected in low benthic diversity and high AMBI values in the inner sites. 相似文献
20.
Mailloux BJ Fuller ME Rose GF Onstott TC DeFlaun MF Alvarez E Hemingway C Hallet RB Phelps TJ Griffin T 《Ground water》2003,41(6):816-827
Ground water injection and sampling systems were developed for bacterial transport experiments in both homogenous and heterogeneous unconsolidated, surficial aquifers. Two types of injection systems, a large single tank and a dynamic mixing tank, were designed to deliver more than 800 L of amended ground water to the aquifer over 12 hours, without altering the ground water temperature, pH, Eh, or dissolved gas composition. Two types of multilevel samplers (MLSs) were designed and installed. Permanent MLSs performed well for the homogenous surficial aquifer, but their installation procedure promoted vertical mixing, which could obfuscate experimental data obtained from vertically stratified, heterogeneous aquifers. A novel, removable MLS was designed to fit in 2- and 4-inch wells. Expandable O-rings between each sampling port hydraulically isolated each port for sample collection when a nut was tightened at the land surface. A low-cost vacuum manifold system designed to work with both MLS designs used 50 mL centrifuge tubes to efficiently sample 12 MLS ports with one peristaltic pump head. The integrated system was developed and used during four field campaigns over a period of three years. During each campaign, more than 3000 ground water samples were collected in less than one week. This system should prove particularly useful for ground water tracer, injection, and push-pull experiments that require high-frequency and/or high-density sampling. 相似文献