成品油管道设计的几个问题

成品油管道设计很多方面相同于原油管道，但由于顺序输送多种油品，存在混油处理和压力调节等特殊问题，设计有其独特处，本文就设计参数优化及工艺计算的某几个问题加以讨论。     

成品油管道罐容优化计算

针对长输成品油管道顺序输送沿线各站罐容计算问题,特别是首站设立在原油加工企业,成品油在大部分通过长输管道外输并均匀补给首站时,指出了国家现行规范对罐容计算的不足,对标准提出的计算方法进行优化,减少成品油管道站场的储罐建设,降低站场用地,节约建设费用.以GB 50253-2003输油管道工程设计规范中罐客计算公式为基础,结合管道沿线各站的实际情况,进行优化计算.实例计算结果表明,按规范计算的罐容明显偏大.     

管道输油设备维修中的问题及其对策

输油设备的完好率和利用率对原油成品油管道输送的经济性有直接影响，作者针对目前输油设备存在的重用轻养、重修轻改、维修技术力量薄弱等问题，提出了成立输油设备维修中心、维修技术和信息培训中心等解决的对策的措施，以提高管道输送设备的整体技术水平。     

发挥管道运输在综合运输体系中的优势——中国管道运输产业政策刍议

<正> 管道运输与铁路、公路、水运、航空运 输并称为当今世界的“五大 运输”方式。它们共同组成运输体系,按照各自特点,各抒其长、相互配合,共同完成社会运输任务。我国管道运输发展潜力巨大。目前,迫切需要制定管道运输产业政策,用以调整管道运输行业健康发展。 一、中国管道运输现状 我国自1970年随着大庆油田的开发,石油管道运输开始起步,26年来,共建成原油、成品油、天然气、煤气和其它介质管道1.8万公里,     

管道运输发展及对铁路能源运输的影响

<正> 管道运输是使用管道输送气体和液体介质货物的现代化运输方式。它具有连续性强、运输量大、不产生空驶、全天候运行、可采用密闭式运输,便于管理。易于实现远程运输自动监控、漏失损耗小等特点,是一个国家能源生产和运输业比较发达的特征之一。管道运输可以输送油品(原油、成品油和液态烃)、天然     

基于声学检测器的成品油管道内检测技术应用研究

针对成品油管道针孔缺陷或微泄漏等常规检测难以识别的技术难题，应用基于声学检测原理的GOTTSBERG Leak Detection (GLD)声学内检测器对成品油管道进行微泄漏内检测研究，在被检测管道上设置了人工模拟泄漏孔等特征点，该技术能够有效识别人工模拟微泄漏以及穿越段、弯头、超声流量计等管道特征信息，为成品油管道的输送安全提供保障。     

国内外石油管道防腐及涂敷技术现状

本文主要论述了石油管道防腐的必要性，管道防腐采用的方法，国外管道涂敷工艺现状以及目前我国石油钢管涂敷工艺和存在问题。推荐了一种符合我国国情的管道涂敷新工艺。     

西部管道创管道工程建设十项第一

一是中石油集团公司近年来第一次在国内大型工程建设项目上实施的EPC项目工程;二是1 858 km长距离、大口径管道采用双管同沟敷设,在我国管道建设史上是第一次;三是当年开工建设,当年敷设3 000多千米管道,并且1 858 km成品油管道及配套站场、阀室竣工,即将投产,在管道建设史上是     

成品油管道运输的发展趋势

<正> 一、我国成品油运输现状 我国成品油运输是伴随着我国炼油工业的发展而壮大的。由于我国炼厂布局分散、规模偏小,成品油管道不发达,因此成品油运输主要以铁路运输为主。据不完全统计,2000年我国成品油(所指成品油除另有说明外,均仅包括汽油、煤油、柴油)运输总量为12730万吨,其中铁路运量为7416万吨,占58.3％;水路运量为3724万吨,占29.2%;公路     

我国港口原油码头布局及供需能力分析

原油是我国港口运输的重要大宗货类,原油码头是石化企业运输网络的关键节点。本文阐述了我国港口原油码头的发展现状和布局特征,对20世纪90年代以来的原油码头通过能力及接卸需求进行分析,分析表明,近年来我国原油码头大型化、专业化趋势明显,码头资源不断整合、布局逐渐完善,但仍存在空间分布"极不均衡"、码头建设"供过于求"、中转码头数量和规模有限、码头建设管理机制混乱等问题。     

Model,process, technique,and the good thing

The paper unpacks the planning process into its component parts: model, process, technique, and goals—the “good thing”. The paper advances the concept that planning, policy-making, and organizational restructuring can be analyzed under the same framework. Each of the four components is described and reductionist examples are presented to clarify the intention and to illustrate the technique that the transport analyst teams employ in their work. The examples cover both successes and failures. They point toward the enormous scientific task ahead for planning to become meaningful and relevant to the problems of today. Finally, in the frame of the willingness to pay, the paper puts forward a case for an institutional framework for a financially autonomous road administration. Similarly organized, administered, and managed entities are relevant also for other transport modes.

Walking frequency, cars, dogs, and the built environment

To explain walking propensity or frequency, empirical studies have generally used two sets of explanatory variables, namely, socio-demographic variables and built environment variables. They have generally shown that both socio-demographic characteristics and built environment characteristics are associated with walking propensity. We examine the traditional walkability variables that encompass density, mix of uses, and network connectivity in New Jersey, using a statewide sample including an oversample of Jersey City. We estimate a two-stage least squares model using a conditional mixed process that combines an ordered probit model of walking frequency in the second stage based on a truncated regression of car ownership in the first stage. Our results show that built environment variables have some small effects, mainly from better network connectivity associated with increased walking frequency. One of our key findings is that built environment features also work indirectly via how they influence car ownership. In general, we find sufficient evidence that suggests fewer cars are owned in areas with more walkable built environment features. The other key variable that we control for is whether a household owns a dog. This also proved to be strongly associated with walking suggesting that dog ownership is a necessary control variable to understand the frequency of walking.     

Space,money, life-stage,and the allocation of time

Demographic, socioeconomic, seasonal, and scheduling factors affect the allocation of time to various activities. This paper examines those variables through exploration of the 1990 Nationwide Personal Transportation Survey, which has been inverted to track activity duration. Two key issues are considered. First, how much can activity duration and frequency explain travel duration? The analysis shows activity duration has positive and significant effects on travel duration, supporting recent arguments in favor of activity based models. Second, which recent trend is the main culprit in the rise in travel: suburbanization, rising personal incomes, or female labor force participation? This paper examines the share of time within a 24-hour budget allocated to several primary activities: home, work, shop, and other. The data suggest that income and location have modest effects on time allocation compared with the loss of discretionary time due to working.

     

Poverty,policy, and public transportation

By all appearances, the circumstances surrounding employment and income distribution in the United States have remained notably the same over the past 30–40 years. At the same time, policies for improving the conditions of low-income persons have remained relatively unchanged. Relevant published accounts continue to cite poorly integrated residential and employment location patterns and poor public transportation service as critical obstacles to improving the economic and social conditions of low-income persons. The relationship between poverty and public transportation was researched extensively during the late 1960s and the early 1970s; however, little recognition has been given to these efforts by more recent research efforts. To learn from the past we should review public transportation policies from 1960 to 2000 to highlight federal policies that affected urban areas during this time period, especially in relation to low-income transportation mobility.     

Governing autonomous vehicles: emerging responses for safety,liability, privacy,cybersecurity, and industry risks

ABSTRACT

The benefits of autonomous vehicles (AVs) are widely acknowledged, but there are concerns about the extent of these benefits and AV risks and unintended consequences. In this article, we first examine AVs and different categories of the technological risks associated with them. We then explore strategies that can be adopted to address these risks, and explore emerging responses by governments for addressing AV risks. Our analyses reveal that, thus far, governments have in most instances avoided stringent measures in order to promote AV developments and the majority of responses are non-binding and focus on creating councils or working groups to better explore AV implications. The US has been active in introducing legislations to address issues related to privacy and cybersecurity. The UK and Germany, in particular, have enacted laws to address liability issues; other countries mostly acknowledge these issues, but have yet to implement specific strategies. To address privacy and cybersecurity risks strategies ranging from introduction or amendment of non-AV specific legislation to creating working groups have been adopted. Much less attention has been paid to issues such as environmental and employment risks, although a few governments have begun programmes to retrain workers who might be negatively affected.     

Activity sequencing,location, and formation of individual non-mandatory tours: application to the activity-based models for Columbus,Cincinnati, and Cleveland,OH

Most of the earlier activity based models (ABMs) largely relied on a tour-based modeling paradigm which explicitly predicts tour frequency and then adds details including stop frequency, order, and location of stops within each tour. The current study is part of new tour formation design framework for an ABM in which the underlying tour structure and the stop frequency within tours emerge from temporal, sequencing, and locational preferences of activities that the traveler intends to participate during the day. In order to do this, the study developed a modified rank-ordered logit (ROL) framework that is capable of modeling sequence, locations, as well as the underlying tour structure of all activity episodes simultaneously in an integrated manner. Model estimation with the household survey data, provided several important behavioral insights into underlying choices that drive tour formation. Specifically, the study uncovered pairwise ordering preferences among episodes of different activity purposes, clustering tendencies among episodes of same activity purpose, the impact of supply side activity opportunities on the location and sequence choice dimensions, and impedance effects (including distance and mode and time-of-day logsums) on location and tour break dimensions. The developed models are incorporated in the operational ABM structure adopted for three major cities (Columbus, Cleveland, and Cincinnati) in Ohio.     

Integrated scheduling of m-truck,m-drone,and m-depot constrained by time-window,drop-pickup,and m-visit using constraint programming

The idea of deploying unmanned aerial vehicles, also known as drones, for final-mile delivery in logistics operations has vitalized this new research stream. One conceivable scenario of using a drone in conjunction with a traditional delivery truck to distribute parcels is discussed in earlier literature and termed the parallel drone scheduling traveling salesman problem (PDSTSP). This study extends the problem by considering two different types of drone tasks: drop and pickup. After a drone completes a drop, the drone can either fly back to depot to deliver the next parcels or fly directly to another customer for pickup. Integrated scheduling of multiple depots hosting a fleet of trucks and a fleet of drones is further studied to achieve an operational excellence. A vehicle that travels near the boundary of the coverage area might be more effective to serve customers that belong to the neighboring depot. This problem is uniquely modeled as an unrelated parallel machine scheduling with sequence dependent setup, precedence-relationship, and reentrant, which gives us a framework to effectively consider those operational challenges. A constraint programming approach is proposed and tested with problem instances of m-truck, m-drone, m-depot, and hundred-customer distributed across an 8-mile square region.     

Adaptive traffic control system: Control strategy,prediction, resolution,and accuracy

Recent advances in traffic control methods have led to flexible control strategies for use in an adaptive traffic control system (ATCS). ATCS aims at controlling the imminent traffic, which is yet to arrive and hence not known perfectly. Therefore, volume prediction is an essential part. Associated with the prediction are two aspects: resolution and accuracy. Recent studies indicate a tradeoff between prediction resolution and accuracy: finer resolutions, larger errors. It is imperative to study the relationship and tradeoff between the control strategy, prediction resolution, and its associated error, which are crucial to the development of ATCS. This study investigates this relationship through an extensive simulation of scenarios in Hong Kong with a recently developed dynamic traffic control model, DISCO. Based on the Hong Kong scenarios conducted with DISCO, the major findings include: (i) the importance of resolution outweighs that of error; (ii) dynamic timing plans generally outperform time‐invariant timing plans; (iii) up to a certain extent, overestimated predictions lead to better results than underestimated predictions.     

Modeling the structural relationships among short-distance travel amounts,perceptions, affections,and desires

Using structural equation modeling, the relationships among travel amounts, perceptions, affections, and desires across five short-distance (one-way trips of less than 100 miles) travel categories (overall, commute, work/school-related, entertainment/social/recreation, and personal vehicle) are examined. The models are estimated using data collected in 1998 from more than 1300 working commuters in the San Francisco Bay Area. A cross-model analysis reveals three robust relationships, namely: (1) myriad measures of travel amounts work together to affect perceptions; (2) perceptions are consistently important in shaping desires; and (3) affections have a positive relationship with desires. The second finding suggests that two individuals who travel the same objective amount may not have the same desire to reduce their travel: how much individuals perceive their travel to be is important. The third point argues that the degree to which travel is enjoyed is a key determinant of shaping desires to reduce travel: the more travel is enjoyed, the less the desire to reduce it.