Airline energy efficiency measures using the Virtual Frontier Network RAM with weak disposability

In this paper, airline energy efficiency is divided into three stages: the operations stage, the services stage and the sales stage. Greenhouse gas emissions are treated as an undesirable output of the services stage. This new three-stage strategic operating framework is a modification of existing models. A new model, Virtual Frontier Network Range Adjusted Measure with weak disposability, is proposed to evaluate the efficiencies of 22 international airlines, from 2008 to 2012. The results show that the new model can establish more reasonable rankings and confirm new benchmarking airlines and that inclusion in the European Union’s Emissions Trading Scheme has had little influence on the improvement of airline energy efficiency.     

Influential vectors in fuel consumption by an urban bus operator: Bus route,driver behavior or vehicle type?

Energy costs account for an important share of the total costs of urban and suburban bus operators. The purpose of this paper is to expand empirical research on bus transit operation costs and identify the key factors that influence bus energy efficiency of the overall bus fleet of one operator and aid to the management of its resources.We estimate a set of multivariate regression models, using cross-section dataset of 488 bus drivers operating over 92 days in 2010, in 87 routes with different bus typologies, of a transit company operating in the Lisbon’s Metropolitan Area (LMA), Rodoviária de Lisboa, S.A.Our results confirm the existence of influential variables regarding energy efficiency and these are mainly: vehicle type, commercial speed, road grades over 5% and bus routes; and to a lesser extent driving events such as: sudden longitudinal decelerations and excessive engine rotation. The methodology proved to be useful for the bus operator as a decision-support tool for efficiency optimization purpose at the company level.     

桨-舵间距对其组合系统水动力性能的影响

本文通过CFD方法对敞水桨、桨-舵组合以及优化间距的桨-舵组合装置开展了数值仿真研究，分析了桨-舵间距对其组合系统的水动力性能影响。螺旋桨敞水工况的计算值与物理模型试验值吻合良好，验证了数值计算方法的可行性。通过对比桨-舵间距大于推荐值的三个工况，发现在较低进阶系数下系统的节能效率有稍许增加，然而随着间距的增大，节能效率呈现降低的趋势；在高进阶系数下，随间距增大节能效率逐步降低。适当减小桨-舵间距，在较低和中等进阶系数下，随间距减小节能效率呈现逐步升高的趋势，在间距减少10mm时，组合体的节能效率最大可增加1.937%；不过在高进阶系数下，随间距减小节能效率却有下降趋势。     

基于内燃动车组的混合动力匹配设计研究

针对内燃动力轨道交通在实际应用中存在的不足以及当前主要新能源技术发展现状,文章结合某内燃动车组的总体参数和配置情况,将内燃机组匹配蓄电池的混合动力方案与纯内燃机组方案进行对比分析,并对混合动力选型和配置进行了计算和分析。结果表明,混合动力匹配方案在降低整车能耗和节省燃油消耗等方面有着显著的优势。     

不同形状质量块的声学超材料结构隔声特性研究

随着对舰船声隐身性能要求的不断提高,舰船隔声材料不仅要轻质还应具有优良的隔声性能。夹层板结构具有轻质,且在高频段具有良好的隔声性能,但其在中低频段隔声性能不是很理想。薄膜型声学超材料结构具有良好的低频带隔声性能,因此本文将薄膜型声学超材料引入传统蜂窝夹层板结构中,设计新的超材料蜂窝夹层板结构。通过数值方法对不同形状质量块超材料结构的隔声特性进行分析,并探讨蜂窝边框形状、质量块大小以及薄膜预应力对米字形质量块超材料结构隔声特性的影响。     

A driver advisory system with dynamic losses for passenger electric multiple units

Driver advisory systems, instructing the driver how to control the train in an energy efficient manner, is one the main tools for minimizing energy consumption in the railway sector. There are many driver advisory systems already available in the market, together with significant literature on the mathematical formulation of the problem. However, much less is published on the development of such mathematical formulations, their implementation in real systems, and on the empirical data from their deployment. Moreover, nearly all the designed driver advisory systems are designed as an additional hardware to be added in drivers’ cabin. This paper discusses the design of a mathematical formulation and optimization approach for such a system, together with its implementation into an Android-based prototype, the results from on-board practical experiments, and experiences from the implementation. The system is based on a more realistic train model where energy calculations take into account dynamic losses in different components of the propulsion system, contrary to previous approaches. The experimental evaluation shows a significant increase in accuracy, as compared to a previous approach. Tests on a double-track section of the Mälaren line in Sweden demonstrates a significant potential for energy saving.     

Efficiency evaluation and PM emission reallocation of China ports based on improved DEA models

The emission of particulate matter (PM) and other atmospheric pollutants in port operations and shipping have caused a huge negative impact on the environment. Consequently, how to evaluate the environmental efficiency of ports and put forward corresponding countermeasures on this basis is becoming a more important issue than ever before from the perspectives of the government, academia, and society. We construct three data envelopment analysis (DEA) models to evaluate the environmental efficiency of ports under the circumstances of environmental control, non-environmental control and PM emission through inter-ports cooperation. The innovation of the DEA models constructed in this paper lies in: (1) Setting environmental control parameters to uniformly manipulate the situations of environmental control and non-environmental control, etc.; (2) Allowing non-equal proportional change of input index, expected output and non-expected output index; (3) Setting preference coefficients for ports to admit favorable decisions; (4) Providing a distance formula of expected output for PM emission reallocation. Further, data from 11 major ports in China are collected to compare the expected output under different PM emission standards assuming the situation of environmental control and non-environmental control, port cooperation, and non-cooperative sewage discharge. The empirical results show that: (1) Ports in the eastern China (Shanghai, Ningbo, and Nanjing) have higher port efficiency; (2) Port cooperation can improve the overall expected output but it will lose its edge with the improvement of PM emission standards. (3) Ports follow the same trend of output loss regardless of favorable decisions. In the end, the author makes a summary, puts forward relevant policy suggestions and makes the recommendation for future research.     

油田注水管道的腐蚀研究与缓蚀剂评价

油田注水管线所输送介质复杂,腐蚀现象严重,存在安全隐患,一旦因腐蚀泄漏就会造成巨大的经济损失。因此,开展油田注水管道的腐蚀研究及采取措施减缓腐蚀具有重要意义。为此,对某油田注水管道现场采集注入水样及腐蚀产物,通过X-射线衍射及X-射线能谱仪进行分析,分析结果表明腐蚀产物主要是碳酸钙,同时含有一定量的氯化物、碳酸亚铁、硫化物等成分。通过电镜扫描腐蚀产物的微观形貌,发现存在氯离子腐蚀。并通过ICP-OES分析输送介质组分,针对其腐蚀特点及输送介质组分,采用失重法及电化学方法评价了引入季铵盐的咪唑啉缓蚀剂HJD2最佳质量分数及缓蚀机理,实验结果表明该缓蚀剂对该注水管道具有较好的缓蚀作用,在现场注水温度下,最佳质量分数(0.06%)时的缓蚀效率为95.1%,通过注入该缓蚀剂可以有效地减缓该注水管线的腐蚀,延长管线的使用寿命。     

Urban single-lane roundabouts: A new analytical approach using multi-criteria and simultaneous multi-objective optimization of geometry design,efficiency and safety

Building safe and effective roundabouts requires optimizing traffic (operational) efficiency (TE) and traffic safety (TS) while taking into account geometric factors, traffic characteristics and local constraints. Most existing simulation-based optimization models do not simultaneously optimize all these factors. To capture the relationship among geometry, efficiency and safety, we put forward a model formulation in this paper. We present a new multi-criteria and simultaneous multi-objective optimization (MOO) model approach to optimize geometry, TE and TS of urban unsignalized single-lane roundabouts. To the best of our knowledge, this is the first model that uses the multi-criteria decision-making method known as analytic hierarchy process to evaluate and rank traffic parameters and geometric elements of urban single-lane roundabouts. The model was built based on comprehensive review of the research literature and existing roundabout simulation software, a field survey of 61 civil and traffic expert engineers in Croatia, and field studies of roundabouts in the Croatian capital city of Zagreb. We started from the basis of Kimber’s capacity model, HCM2010 serviceability model, and Maycock and Hall's accident prediction model, which we extended by adding sensitivity analysis and powerful MOO procedures of the bounded objective function method and interactive optimization. Preliminary validation of the model was achieved by identifying the optimal and most robust of three geometric alternatives (V.1-V.3) for an unsignalized single-lane roundabout in Zagreb, Croatia. The geometric parameters in variant V.1 had significantly higher values than in the existing design V.0, while approaches 1 and 3 in variant V.2 were enlarged as much as possible within allowed spatial limits and Croatian guidelines, reflecting their higher traffic demand. Sensitivity analysis indicated that variant V.2 showed the overall highest TE and TS across the entire range of traffic flow demand and pedestrian crossing flow demand at approaches. At the same time, the number of predicted traffic accidents was similar for all three variants, although it was lowest overall for V.2. The similarity in predicted accident frequency for the three variants suggests that V.2 provides the greatest safety within the predefined constraints and parameter ranges explored in our study. These preliminary results suggest that the proposed model can optimize geometry, TE and TS of urban single-lane roundabouts.