CO2 ocean sequestration by moving ships

Ocean sequestration of the CO₂ captured from fossil-fuel burning is a possible option to mitigate the increase in CO₂ concentration in the atmosphere. It can isolate huge amounts of CO₂ from the atmosphere for a long time at relatively low cost, if it is acceptable from the viewpoint of the environmental impact on the ocean. The concept of CO₂ dispersion in the ocean depths by ships is a promising method for efficient dilution. That is, liquefied CO₂ is delivered to the site and injected into the ocean at depths of 1000–2500 m with a suspended pipe towed by a slowly moving ship. In addition to the horizontal movement of the release point, the vertical journey of CO₂ droplets until they disappear by dissolution is effective for the dilution of CO₂ in seawater. In this paper, the possibility of the generation of relatively large-sized droplets from a moving nozzle is investigated experimentally. In addition, the terminal velocity of CO₂ droplets in deep-sea circumstances is measured in a large high-pressure tank to investigate the influence of the hydrate film formed on the surface of the droplet. Finally, it is shown by simulation that an initial dilution ratio of one to some ten thousandths is possible on a realistic engineering scale in the moving ship type of CO₂ ocean sequestration. Received: August 7, 2001 / Accepted: September 13, 2001     

材料成型及控制工程专业应用型本科人才培养方案的研究与实践

在对材料成型及控制工程专业应用型本科人才的培养目标及知识、能力、素质结构进行深入分析的基础上,构建了具有一定特色的人才培养方案,较好处理了拓宽口径与专业素质教育之间的关系,突出了专业特色.较为科学地解决了人才培养方案实施中的问题,人才培养质量提高.     

美国铁路客车的发展动向与水平

文章阐述了美国地铁、高速列车等轨道车辆的发展水平、动态,以及铁道车辆市场现状。介绍了美国针对铁路事故而开展提高车辆强度、抗碰撞能力的研究及取得的成果。     

政策制定中交通弱势群体受抑制需求分析方法

在交通弱势群体受抑制需求可被计算、并将其加入现有出行需求的前提下,提出一种预估交通供需的方法。该方法的潜在假设是交通弱势群体的出行条件和普通群体相同,即所谓的受抑制需求＂全部释放＂。在利用＂四阶段＂法为交通弱势群体建模的过程中,分析了交通弱势群体的受抑制需求及其与普通群体间的平等问题,同时详尽阐述了最易受伤害的交通弱势群体（如老年人和残疾人）的特殊需求,并确定其在各方面面临的困难。最后,利用软件模拟分析得出的结论是：针对交通弱势群体全部释放的受抑制需求（出行总量增加5%）,政策制定者须为面临一定的财政负担做好准备,同时做好协调工作,达到既减少运营成本又满足交通弱势群体出行需求的目标。     

Big data framework for quantitative trading system

Massive trading data are produced in securities market every day. Besides, the amount of relevant social media data is also growing fast. It is a vital problem of making use of these data. Facing on the growing amount of data, using big data framework is a necessary and reasonable method. Then, a big data framework for quantitative trading system is proposed in this paper. In the framework, Apache Spark is chosen as the distributed computing framework to process trading data, and Apache HBase as the distributed database is used to store data. After introducing the whole framework, we discussed data sources and the structure of quantitative trading layer in detail.     

Incentive subsidy scheme design with elastic transport demand

Huge public transport subsidies caused by deficits have become a heavy financial burden on some local governments due to the decline of bus passenger numbers. It is essential to apply the performance‐based contract to bus services considering maximization of social welfare. This paper constructs an incentive subsidy contract considering the decision‐making powers of the service level and calculating the proper frequency elasticity aiming at two problems of performance‐based contracts. Meanwhile, we consider a role of bus operators ignored by most researchers. Under the scheme, the decision‐making power of the service level is discussed based on five assumptions, and meanwhile, bus operators are motivated to reduce cost and improve service level in the scheme. The case of the bus service of Arao city indicates that the optimal frequency equals to zero when bus operators decide frequency. If bus operators determine efforts, the optimal effort also equals to zero with the goal of maximizing the profit. Also, bus operators can play their roles in lessening cost and improving service level to help bus operators and the local government achieve a win‐win situation, which maximizes the social benefit in this subsidy scheme when all factors are decided by the government. Copyright © 2013 John Wiley & Sons, Ltd.     

Fracture control of extremely thick welded steel plates applied to the deck structure of large container ships

The rapid enlargement of the size of container ships has led to the application of extremely thick plate in the deck structures, which may grow concerns about the fracture toughness at the butt-weld with large amount of heat input, and the arrest toughness of brittle crack propagation in the base metal of such thick plates. Also, slam-induced whipping stresses might affect the fatigue crack propagation and the initiation of a brittle crack in a container ship. In order to prevent the catastrophic failure of deck structures by brittle fracture, national joint research projects, which focused on the safety-related issues of extremely thick steel plate applied to hull of large container ships, were formed from April 2007 to March 2011 organized by the Japan Ship Technology Research Association (JSTRA) supported by the Japanese Government in collaboration with universities, national research institute, classification societies and relevant industries including shipbuilding, steel manufacturing and shipping companies. The joint research projects have carried out the investigations on crack initiation toughness of the weld, fatigue crack propagation under seaway loading, the potential of defect detection by ultrasonic testing, and the crack-arrest methods after brittle crack propagation. Practical recommendations to prevent brittle fracture of large container ships were proposed based on these comprehensive investigations. The essential parts of the above research activities are presented in this paper.     

A suppressed demand analysis method of the transportation disadvantaged in policy making

Abstract

This paper proposes a method for estimating transportation supply requirements when the suppressed demand of the transportation disadvantaged (TD) can be calculated and added to existing demand for travel. The underlying assumption is that the travel conditions of these TD groups must be equal to the ‘conventional’ demand, known as ‘full release’. Utilising the modelling approach for TD, suppressed demand analysis, diagnosis of difficulties and equity between conventional and disadvantaged groups were realised, while elaborating special cases for the most vulnerable TD groups (such as elderly and disabled persons) and simultaneously identifying areas of difficulty. From the early virtual results, it is concluded that, for the full release of suppressed trips (only a 5% increase), policy makers must be ready to face some financial burdens, requiring coordination of effort to both standardise these TD groups and reduce the costs incurred by operators.