Energy efficiency and time charter rates: Energy efficiency savings recovered by ship owners in the Panamax market

This paper presents the first analysis on how financial savings arising from energy efficient ships are allocated between owners and those hiring the ships. This as an important undertaking as allocation of financial savings is expected to have an impact on the incentives faced by ship owners to invest in more energy efficient vessels. We focus on the dry bulk Panamax segment as it contributes to around 50 Mt (5%) of total CO₂ emissions from shipping in 2007 and therefore its importance in terms of environmental impact should not be neglected. The time charter market represents a classical example of the principal–agent problem similar to the tenant–landlord problem in the buildings sector. We discovered that on average only 40% of the financial savings delivered by energy efficiency accrue to ship owner for the period 2008–2012. The finding that only part of the savings are recouped by shipowners affecting their incentives towards energy efficiency could consequently have implications on the type of emission reduction policies opted at both, global and regional levels.     

Analysis of thirty years evolution of urban growth,transport demand and supply,energy consumption,greenhouse and pollutants emissions in Greater Cairo

The objective of the paper is to analyze evolution of urbanization, transport demand and supply in Greater Cairo (GC) over the last three decades of the 20th century. This is in addition to investigating the impact of city growth on energy consumption and emissions from transport. It utilizes results of 1971, 1978, 1987, 1998 and 2001 travel demand surveys, undertaken during the corresponding GC transport studies; each was published a year or two later. No further transport studies have been carried out in GC over the past decade and in view of the current political situation, it is not envisaged that similar studies will be undertaken in the near future. The analysis includes the evolution of daily trips, trip purpose share, modal share and number of cars. More recent trends for 2006/2007 vehicle registration by type and size are given. The evolution of transport supply covers projects until early 2012. In parallel estimates of the evolution of energy consumption and cost, emissions of greenhouse gases (CO₂) and pollutants (CO, HC and NO_x) are given for 1971/2001. The adopted estimation methodology is summarized. Comparative analysis of relevant evolution indexes and trends of growth between 1971 and 2001, taking the former as base year, is given. Land use and transport policies and projects that in some cases helped, directly or indirectly, to reduce traffic congestion, or at least prevented an increase, are addressed, commenting on their outcomes. Thus, transferable experience are useful to sister cities benefiting from successes and avoiding drawbacks. The evolution of the impact of GC metro on energy consumption and cost, and GHG emissions is given for 1987/2001, assuming the scenario “metro did not exist”. More recent impact analysis is given for 2007/2008, as the data allowed estimating traffic volumes that would have been added to the congested metro corridors under the above scenario; and the related fuel consumption and cost and GHGs. The paper ends with conclusions on GC evolution, learned lessons and suggests repeating similar work in other mega cities of the developing countries. Further research is emphasized, e.g., modeling the relationship between land use, transport, energy and emissions; modeling emission factors by vehicle type; and studying fuel-subsidy-reduction scenarios and their socio-economic effects.     

周期性钢弹簧浮置板轨道垂向振动带隙特性研究

为研究周期性钢弹簧浮置板轨道的带隙特性,将钢轨和浮置板分别视为铁木辛柯梁和明德林板,建立周期性钢弹簧浮置板轨道垂向振动模型,基于能量变分原理求得其垂向带隙,分析带隙的形成机理以及轨道结构刚度对带隙的影响.结果 表明:在0～1200 Hz范围内,周期性钢弹簧浮置板轨道结构存在5条垂向振动带隙,1阶和3阶带隙为局域共振带隙...     

列车脱轨机理与脱轨分析理论研究

在分析国内外脱轨研究现状的基础上，总结出脱轨研究中存在如下主要问题。（1）现有预防脱轨标准对实际列车脱轨没有控制作用。（2）不明原因列车脱轨机理不明确。（3）列车脱轨计算存在3个根本问题：①列车-轨道（桥梁）时变系统振动方程组的建立与求解未满足轮轨位移衔接条件；②仅以轨道横向不平顺作为列车-轨道（桥梁）时变系统横向振动的激振源，未考虑根本激振源——轮轨接触状态的影响；③仅以轨道不平顺的随机性和按时不变系统随机振动分析理论，     

外墙外保温技术在节能住宅设计中的运用

住宅耗能占全社会总能耗的25％，发展节能型住宅迫在眉睫。此文提出外墙外保温技术的优越性，通过运用此技术在节能住宅设计中的理论计算和构造示意，以及在实际工程中的能耗分析，证明外墙外保温运用在节能住宅中带来的经济效益和社会效益，从而展示外墙外保温技术的发展前景。     

Intersection traffic energy management system (ITEMS): formulation and validation

Urban transportation and traffic face significant challenges as cities continue to grow. Traffic intersections present unique challenges for city planners. Several studies have proposed diverse approaches to managing intersection traffic. However, these typically fail to reduce both energy and trip time for all vehicles involved. This paper proposes the intersection traffic energy management system (ITEMS). By using speed regulation of two vehicles approaching an intersection on crossroads, ITEMS is able to resolve intersection conflicts. This obviates the need for either vehicle to stop. Two-vehicle and four-vehicle scenarios were simulated. It was found that ITEMS reduced the total energy about 22% and the trip time across the intersection by almost 16% for every scenario compared to a traditional fixed-timed traffic light intersection. ITEMS was also found to be superior than always giving a green light to urban transit vehicles. Furthermore, with ITEMS, the energy and trip time of each vehicle in the scenario was reduced when compared to other strategies.     

新能源汽车的故障问题分析与维修关键技术

新能源汽车是解决环境污染问题、缓解能源匮乏局面的重要举措,在新能源汽车研发中,需要对其故障特点进行明确,大力开展相关维修关键技术研究,只有这样才能提高新能源汽车的安全水平,使其在市场中得到更为广泛的推广与应用。鉴于此,文章便对新能源汽车的故障问题进行分析,在此基础上提出相应的维修关键技术。     

列车牵引能耗计算方法

针对列车牵引能耗既有计算方法缺乏统计标准和能耗预测手段,通过分析机车性能、线路属性等因素对列车牵引能耗的影响,提出新的能耗计算方法。算法步骤是:客车按照车次、货车按照机车交路确定列车运行经路;按照列车起停、运行、惰行及空转、出入段及调车、上坡5种牵引过程,分别计算各区段的列车牵引能耗;按照列车径路累加各区段的能耗值,并换算为油、电的消耗量,最终计算出能耗费用。据此开发列车牵引能耗计算软件系统,以宝成线、丰台机务段为例进行能耗计算及影响因素分析,以DJ4和SSJ3为例进行新型机车牵引能耗的预测。结果表明,应用此计算方法和系统能够及时掌握列车牵引能耗的变化。     

浅析新能源汽车热管理远程控制

本文主要介绍新能源汽车热管理远程云控制的应用和设计思路,利用手机APP、后台中央计算机、车载通信终端、汽车CAN局网络等技术实现新能源汽车热管理的远程控制,使用户更加便捷地了解和控制车辆的当前冷热状态,可以有效提高新能源车辆的使用安全性和舒适性。     

基于RANS法毂帽鳍节能性能参数匹配研究

数值剖析毂帽鳍节能装置作用机理,研究参数性能匹配问题,应用雷诺时均法处理数值粘性绕流场,建模阶段采用FORTRAN语言编制螺旋桨毂帽鳍型值点数据处理程序以便GAMBIT前处理软件进行接口,对标准B4-40螺旋桨进行数值验证和分析比较某特种螺旋桨不同叶数参数性能数值计算结果,进而研究毂帽鳍参数匹配问题,研究不同鳍叶直径和不同安装角对桨效率变化的影响,分析压力场和尾流场的变化状况,结果表明：大小合适的鳍叶直径和合理的安装角明显提高其推进效率,具有工程实用性。