Impact of Improving Design Factor over 0.72 on the Safety and Reliability of Gas Pipelines and Feasibility Justification

Many years experience of the operation of high stress (>72% specified minimum yield strength, SMYS) gas pipelines and statistical analysis results of pipeline incidents showed that the operating pipelines at stress levels over 72% SMYS have not presented problems in USA and Canada, and design factor does not control incidents or the safety of pipelines. Enhancing pipeline safety management level is most important for decreasing incident rate. The application history of higher design factors in the U.S and Canada was reviewed. And the effect of higher factors to the critical flaw size, puncture resistance, change of reliability with time, risk level and the arrest toughness requirements of pipeline were analyzed here. The comparison of pipeline failure rates and risk levels between two design factors (0.72 and 0.8) has shown that a change in design factor from 0.72 to 0.8 would bring little effect on failure rates and risk levels. On the basis of the analysis result, the application feasibility of design factor of 0.8 in China was discussed and the related suggestions were proposed. When an operator wishes to apply design factor 0.8 to gas pipeline, the following process is recommended: stress level of line pipe hydro test should be up to 100% SMYS, reliability and risk assessment at the design feasibility or conceptual stage should be conducted, Charpy impact energy should meet the need of pipeline crack arrest; and establish and execute risk based integrity management plan. The technology of pipeline steel metallurgy, line pipe fabrication and pipeline construction, and line pipe quality control level in China achieved tremendous progresses, and line pipe product standards and property indexes have come up to international advanced level. Furthermore, pipeline safety management has improved greatly in China. Consequently, the research for the feasibility of application of design factor of 0.8 in China has fundamental basis.

Seismic design factors for RC special moment resisting frames in Dubai,UAE

This study investigates the seismic design factors for three reinforced concrete （RC） framed buildings with 4, 16 and 32-stories in Dubai, UAE utilizing nonlinear analysis. The buildings are designed according to the response spectrum procedure defined in the 2009 International Building Code （IBC＇09）. Two ensembles of ground motion records with 10% and 2% probability of exceedance in 50 years （10/50 and 2/50, respectively） are used. The nonlinear dynamic resPonses to the earthquake records are computed using IDARC-2D. Key seismic design parameters are evaluated; namely, response modification factor （R）, deflection amplification factor （Cd）, system overstrength factor （Ωo）, and response modification factor for ductility （Rd） in addition to inelastic interstory drift. The evaluated seismic design factors are found to significantly depend on the considered ground motion （10/50 versus 2/50）. Consequently, resolution to the controversy of Dubai seismicity is urged. The seismic design factors for the 2/50 records show an increase over their counterparts for the 10/50 records in the range of 200%-400%, except for the D~ factor, which shows a mere 30% increase. Based on the observed trends, perioddependent R and Cd factors are recommended if consistent collapse probability （or collapse prevention performance） in moment frames with varying heights is to be expected.

Design of Full-Ocean-Depth Self-Floating Sampler and Analysis of Factors Affecting Core Penetration Depth

The hadal zone(ocean depths of 6 – 11 km) is one of the least-understood habitats on Earth because of its extreme conditions such as high pressure, darkness, and low temperature. With the development of deep-sea vehicles such as China's 7000 m manned submersible Jiaolong, abyssal science has received greater attention. For decades, gravity-piston corers have been widely used to collect loose subsea-sediment long-core samples. However, the weight and length of the gravity sampler cables and the operating environment limit sampling capacity at full ocean depths. Therefore, a new self-floating sediment sampler with a spring-loaded auto-trigger release and that incorporates characteristics from traditional gravity-driven samplers is designed. This study analyzes the process by which a gravity-piston corer penetrates the sediment and the factors that affect it. A formula for obtaining the penetration depth is deduced. A method of optimizing the sampling depth is then developed based on structure design and parametric factor modeling. The parameters considered in the modeling include the sampling depth, balance weight, ultimate stress friction coefficient, dimensions of the sampler, and material properties. Thus, a new deep-sea floating parametric sampler designed based on virtual prototyping is proposed. Accurate values for all the design factors are derived from calculations based on the conservation of energy with penetration depth, analyses of the factors affecting the penetration depth, and analyses of the pressure bar stability. Finally, experimental data are used to verify the penetration-depth function and to provide theoretical guidance for the design of sediment samplers.

Assessment of seismic design response factors of concrete wall buildings

To verify the seismic design response factors of high-rise buildings, five reference structures, varying in height from 20- to 60-stories, were selected and designed according to modern design codes to represent a wide range of concrete wall structures. Verified fiber-based analytical models for inelastic simulation were developed, considering the geometric nonlinearity and material inelasticity of the structural members. The ground motion uncertainty was accounted for by employing 20 earthquake records representing two seismic scenarios, consistent with the latest understanding of the tectonic setting and seismicity of the selected reference region （UAE）. A large number of Inelastic Pushover Analyses （IPAs） and Incremental Dynamic Collapse Analyses （IDCAs） were deployed for the reference structures to estimate the seismic design response factors. It is concluded that the factors adopted by the design code are adequately conservative. The results of this systematic assessment of seismic design response factors apply to a wide variety of contemporary concrete wall buildings with various characteristics.

Development of Product Design Projects Applying Specifications and Factors Matrix (SFM) as a Support Tool in Higher Education

The application of work strategies taking into account, from the initial stages, all the factors involved in the product design process is considered essential by the researches to generate higher quality products, assess users’ needs and anticipate design problems. This paper presents two approaches of design project development, denominated respectively: projects with imposed specifications and projects with derived specifications and proposes the use of the matrix that integrates specifications and design factors (SFM). This design support tool complements others already used in the development of product concepts by higher education students, increasing the capacity of synthesis and structuring of information in order to facilitate decision-making into the design process. Its elaboration implies understanding of objectives, identifying of factors and establishing of specifications. At the same time, it aims to foster the reflection process and an integrated information analysis. The application of SFM and its contribution to different project approaches are shown in this paper.

PHASE STRUCTURE FACTOR AND INTERFACE CONJUNCTION FACTOR OF CAST IRON AND ITS COMPOSITION DESIGN

Theempiricalelectrontheory of solidsand molecules( EET) and theimproved TFDtheory wereapplied tocalculatethe phasestructurefactorsand interfaceconjunction factorsofcom mon alloying elementsincastiron. Akind of Si- Mo- Cu ductileiron with rareearth Mg asnodularizer was designed accordingtothese valenceelectron structure parameters. Actual applicationtestsshow thatthelongevity of thisiron is 1.5 timesof thatof high manganesesteel. This accordance of theoretical results and actual effectsshows the composition design methodcan beused in othercastiron research.

基于Design-expert的醋酸纤维/煤基分级多孔炭制备优化

当前煤层气利用的主要方式是直接燃烧,该过程会产生大量温室气体(CO_(2))排放,且会造成稀缺资源的低附加值利用。为实现煤层气的高附加值利用,拟通过在煤中原位添加醋酸纤维和KOH活化的方法制备一种醋酸纤维/煤基分级多孔炭材料,并将其应用于煤层气直接裂解制氢,不仅可以获得高纯氢气,还能得到一定数量的纳米碳材料。醋酸纤维/煤基分级多孔炭在制备过程中需要考虑温度、碱碳质量比、溶剂量和其他碳源添加量对制备过程和转化率的影响,利用Design-expert软件对试验方案进行优化设计。通过响应曲面法和部分试验数据对各影响因素与转化率的关系进行分析,建立相应拟合回归方程,得出理论最优解。通过将最优解与试验结果进行对比分析,验证Design-expert软件在多因素多水平条件下的预测可靠性,同时也阐明最优条件下炭材料催化裂解煤层气的机理。结果表明,温度和碱碳质量比是醋酸纤维/煤基分级多孔炭制备过程的最大影响因素,建立相关因素与转化率之间的拟合回归方程并求出理论最优解。理论最优解与试验值之间的最大误差为3.05%,说明Design-expert软件对制备过程的优化准确可靠。醋酸纤维/煤基分级多孔炭催化裂解煤层气较原煤炭材料具有高的转化率和稳定性,前者反应后表面生成大量碳球,而后者表面则生成少量碳纤维和大量碳球。

载人航天人机交互界面色彩设计方法研究

目的对载人航天人机交互界面的色彩设计方法流程进行了梳理和分析。方法遵循“以人为中心”的设计原则,从色彩空间与模型、色彩设计与人因、航天色彩设计范围、载人航天器色彩设计模型,以及载人航天器色彩设计与人因评价体系等方面,对载人航天器人机交互界面色彩设计方法流程体系进行了探讨。结果构建了载人航天色彩设计模型,阐述了完整的载人航天色彩设计方法流程体系。结论针对载人航天人机交互色彩设计方法的研究为航天员在轨环境中的生活品质及工作效能等相关领域的提高提供了有力支持,进一步增强了航天领域色彩设计与人因工程的重要性。

基于DEMATEL-ISM的公共设施可持续设计提升策略研究

目的 为探索可持续设计需求在公共设施设计中的重要性问题,准确全面地推进公共设施的可持续设计,构建覆盖公共设施生命全周期的多指标设计体系模型,对设计阶段前期的因素重要性需求及相关性进行评估。从而支持在后续的公共设施设计过程中的可持续设计评估。方法 以可持续设计的环境价值、经济价值和社会价值为目标层,对美景度、环保度等9个影响因素进行分析,获取公共设施在可持续设计方面的各种影响因素,构建研究体系。在此基础上,提出运用DEMATEL-ISM组合模型探究各制约因素间的复杂影响关系,利用排序和重要性结果,寻找关键要素,绘制层级关系示意图,使各种因素之间的关系更加条理化、层次化。根据计算结果提出有助于在设计阶段提高公共设施设计可持续的策略及建议。结果 研究表明,在公共设施的可持续设计中,实用度和可控度的中心度最高,为重要的影响因素。公共设施可持续设计需要以提高美景度及和谐度为改善基础,实用度、可控度和体验度为调节因素,最终通过控制环保度、耐久度等因素,保障公共设施设计的可持续运行。结论 基于DEMATEL-ISM可以直观清晰地展现公共设施可持续设计影响因素之间的相互关系。通过对模型信息的理性分析,能够促使后期设计方案在公共设施生命全周期的各个维度上具有可持续性,并在理论层面为设计环节的决策提供参考依据。

Study on strength reduction factors consid-ering the effect of classification of design earthquake

The strength reduction factors are not only the key factors in determining seismic action for force-based seismic design, but also the key parameters to derive the inelastic response spectra for performance-based seismic design. In this paper, with a high quality ground motion database that includes a reasonable-sized set of records from China, a statistical study on the strength reduction factors is conducted and a new expression of strength reduction factors involving classification of design earthquake, which is an important concept to determine design spectra in Chinese seismic design code, is proposed. The expression of strength reduction factors can reflect the ground motion characteristics of China to a certain extent and is particularly suitable for Chinese seismic design. Then, the influence effects of site condition, classification of design earthquake, period of vibration, ductility level, earthquake magnitude and distance to fault on strength reduction factors are investigated. It is concluded that the effect of site condition on the strength reduction factors cannot be neglected, especially for the short-period structures of higher ductility. The classification of design earthquake also has an important effect on strength reduction factors and it may be unsuitable to use the existing expressions of strength reduction factors to the design spectra of current Chinese seismic code. The earthquake magnitude has no practical effect on strength reduction factors and if the near-fault records with forward directivity effect are not taken into consideration, the effect of distance to fault on strength reduction factors can also be neglected.

Characterization of Six Categories of Systematic 2^{<i>n</i>-(<i>n</i>-<i>k</i>)}Fractional Factorial Designs

Six categories of systematic 2n-(n-k) designs derivable from the full 2k factorial experiment by the interactions-main effects assignment are available for carrying out 2n-(n-k) factorial experiments sequentially run after the other such that main effects are protected against the linear/quadratic time trend and/or such that the number of factor level changes (i.e. cost) between the runs is minimal. Three of these six categories are of resolution at least III and three are of resolution at least IV. The three categories of designs within each resolution are: 1) minimum cost 2n-(n-k) designs, 2) minimum cost linear trend free 2n-(n-k) designs and 3) minimum cost linear and quadratic trend free 2n-(n-k) designs. This paper characterizes these six categories and documents their differences with regard to either time trend resistance of factor effects and/or the number of factor level changes. The paper introduces the last category of systematic 2n-(n-k) designs (i.e. the sixth) for the purpose of extending the design resolution from III into IV and also for raising the level of protection of main effects from the linear time trend into the quadratic, where a catalog of minimum cost linear and quadratic trend free 2n-(n-k) designs (of resolution at least IV) will be proposed. The paper provides for each design in any of the six categories: 1) the sequence of its runs in minimum number of factor level changes 2) the defining relation or its 2n-(n-k) alias structure and 3) the k independent generators needed for sequencing the 2n-(n-k) runs by the generalized foldover scheme. A comparison among these six categories of designs reveals that when the polynomial degree of the time trend increases from linear into quadratic and/or when the design’s resolution increases from III to IV, the number of factor level changes between the 2n-(n-k) runs increases. Also as the number of factors (i.e. n) increases, the design’s resolution decreases.

灰竹炭纤维/大麻纤维/Coolplus纤维/棉精梳混纺柔洁纱的可纺性研究与生产实践

本文结合生产实践,通过设备改造和半制品及纱测试,分析和讨论各因素对灰竹炭纤维/大麻纤维/Coolplus纤维/棉精梳混纺柔洁纱质量的影响,研究前纺工序和细纱工序通过优化工艺参数、采用新型纺纱专件、合理控制车间的温湿度等,明显地提高了灰竹炭纤维/大麻纤维/Coolplus纤维/棉精梳混纺柔洁纱质量。

火麻仁黄嘌呤氧化酶抑制肽的酶解制备工艺研究

为寻找开发火麻仁蛋白,提高火麻应用价值的最佳条件,以火麻蛋白为原料,通过酶解法制备火麻仁黄嘌呤氧化酶抑制肽,采用正交试验法优化中性蛋白酶酶解火麻蛋白制备多肽的最佳工艺条件。以中性蛋白酶用量、酶解时间、酶解温度进行单因素试验,通过正交试验分析获得制备火麻仁黄嘌呤氧化酶抑制肽的最佳酶解条件为pH值6.5,料液比1∶5,酶用量6000 U/g,酶解温度50℃,酶解时间5 h。在此条件下进行的验证试验中,多肽抑制率为78.98%,表明该工艺稳定、可行,具有较高的应用价值。

初级卫生保健领域量表的设计与开发:实用步骤与统计方法

本文概述了在初级卫生保健领域设计和开发有效、可靠问卷的统计学方法和实用步骤。回顾了一系列关于问卷编制和量表设计的研究,并制定了一套在初级卫生保健领域进行量表设计的标准化流程。该流程涉及量表设计过程中关键且实用的步骤及统计学方法,并结合以往该领域的相关研究案例加以说明。建议的初级卫生保健领域问卷的七步编制方法为:(1)定义测量的构念;(2)生成条目池;(3)选择评分系统和响应格式;(4)预测试(评估内容效度和表面效度等);(5)通过项目分析剔除条目;(6)量表的初次评价,包括量表的信度和效度评价,以及因素分析或Rasch分析;(7)量表的再次评价,重新检验量表的性质,包括重测信度和结构效度。总的来说,量表设计类研究应严格按照量表编制的标准步骤,综合使用Rasch分析和因素分析的方法,这可以使量表的测量结果更加客观。

建筑空间最优节能设计模型仿真研究

由于建筑结构主体较多,空间能耗难以合并控制,导致目前建筑空间能源耗用量较大。为此,构建基于等效转换法的建筑空间最优节能模型,并对其仿真研究。提出建筑总体能耗作为初始优化的“尺度”概念,该尺度为建筑空间的外墙、内墙、屋顶、分户楼板以及门窗等参数,求解这些尺度的最佳标准值。采用等效转换法计算在节能条件下所能接受的最大能耗范围。在此基础上,以上述范围值为约束条件,建立控制函数。将上述提到标准尺度值和最大能耗范围设置为最优解,建立最优节能设计模型,设定温差调节因子,对每一次室内外温差实施有效调节控制,保证建筑体参数符合最佳能耗范围。仿真结果证明,所提方法对冬季采暖和夏季制冷的能耗控制效果均较佳,节能效果最优且算法收敛性高,鲁棒性较好。

膨胀型钢结构防火涂层隔热性能的研究进展

隔热性能的准确量化是防火涂层厚度设计的关键。膨胀型钢结构防火涂层的隔热性能在高温下受升温速率的影响,投入使用后其隔热性能会发生退化,这些特点给膨胀型钢结构防火涂层的厚度设计提出了挑战。总结了膨胀型钢结构防火涂层隔热性能的定量表征方法,分析了隔热性能的影响因素以及这些因素的作用机理和规律,提出了膨胀型钢结构防火涂层厚度设计涉及的关键科学问题及解决方法。

响应面法优化褐藻胶降解菌Cobetia sp.20发酵培养基

为了提高褐藻胶降解菌株Cobetia sp.20产褐藻胶裂解酶的能力,利用响应面法优化其发酵产褐藻胶裂解酶的培养基。首先利用单因素法分别对发酵培养基中的不同碳源、碳源添加量、不同氮源、氮源添加量以及氯化钠添加量、磷酸二氢钾添加量、硫酸镁添加量和pH进行探究,研究各因素对产酶的影响。在单因素实验的基础上,通过Plackett-Burman试验确定Cobetia sp.20发酵培养基中影响产酶的主要因素。通过响应面试验建立回归方程。研究结果表明,Cobetia sp.20最优发酵培养基配方为褐藻胶15.00 g/L、硫酸铵7.50 g/L、氯化钠15.00 g/L、硫酸镁0.50 g/L、磷酸二氢钾5.30 g/L、硫酸亚铁0.01 g/L、pH值7.58。优化后酶活为142.79 U/mL,比优化前提高了26.36%。褐藻胶裂解酶活的提高,为褐藻胶裂解酶的工业化生产提供了参考。

海岛色彩多因素分析及多方案比较

文章通过对圣托里尼、意大利五渔村、舟山普陀山等海岛渔村进行分析,归纳出自然色彩、产业习俗、宗教信仰三个主要的色彩影响因素。同时,以浙江省舟山市葫芦岛为案例分析对象,提取当时自然地理环境色彩因子与人文地理环境色彩因子,综合自然与人文色彩因子,确定外部环境色彩设计的组配依据,提出海洋人居环境下的色彩主色调,并设想可行性色彩运用方法。

基于用户多维感官需求的苗绣产品可拓设计方法

分析用户对于苗绣产品体验过程的感官需求,提出基于用户多维感官需求的苗绣产品可拓设计方法,重塑苗绣产品新体验。从用户的感官体验需求的角度出发,从视觉、触觉、嗅觉、心觉多个维度进行分析,剖析用户在多维度感官体验上对苗绣产品的需求意象,明确用户需求意象与设计因子匹配关系,运用可拓设计相关理论把苗绣产品设计因子进行重构。通过理论和实践为苗绣产品创新设计提供参考。用户多维感官需求分析优化了设计师进行设计时对用户需求分析的准确度,同时能够让用户在与苗绣的互动过程中获得全新的产品体验。