Implementing demand response 2.0: Progress toward full potential in the United States

Demand response can be an excellent flexible resource and can cost-effectively support a grid with high penetrations of variable renewable generation. Unfortunately, this potential has not yet been widely exploited, due to a number of obstacles at the wholesale and distribution levels. This article reviews those barriers and the prospects for better uptake of demand response.     

Mapping ICT use at home and telecommuting practices: A perspective from work/family border theory

This study draws on the work/family border theory to investigate the role of information communication technology (ICT) use at home in shaping the characteristics of work/family borders (i.e. flexibility and permeability) and consequently influencing individuals’ perceived work-family conflict, technostress, and level of telecommuting. Data were collected from a probability sample of 509 information workers in Hong Kong who were not self-employed. The results showed that the more that people used ICT to do their work at home, the greater they perceived their work/family borders flexible and permeable. Interestingly, low flexibility and high permeability, rather than the use of ICT at home, had much stronger influences on increasing, in particular, family-to-work conflict. As expected, work-to-family conflict was significantly and positively associated with technostress. Results also showed that the telecommuters tended to be older, had lower family incomes, used ICT frequently at home, and had a permeable boundary that allowed work to penetrate their home domain. The theoretical and practical implications are discussed.     

Top-gate organic field-effect transistors fabricated on paper with high operational stability

We report on top-gate organic field-effect transistors (OFETs) fabricated on specialty paper, PowerCoat™ HD 230 from Arjowiggins Creative Papers coated with a buffer layer composed of a polyvinyl alcohol (PVA) and polyvinylpyrrolidine (PVP) blend. OFETs operate at low voltages and display average carrier mobility values of 1.7 ± 1.1 × 10⁻¹ cm²/Vs, average threshold voltage values of −1.4 ± 0.2 V, and average on/off current ratio of 10⁵. OFETs also display excellent operational stability demonstrated by stable 1000 scans of the transfer characteristics and by stable on-currents displaying less than 6% change during a DC bias stress test at V_DS = V_GS = −10 V for 1 h. Furthermore, OFETs on paper display a decrease of only 7% in their on-state current during a bending test. The performance of these OFETs on paper is comparable to that displayed by top-gate OFETs with the same geometry fabricated on glass substrates.     

技术改造提高加氢试验装置的灵活性

介绍了加氢试验评价装置在加氢技术研发过程中的重要性,结合现有试验装置的现状及存在的问题,提出针对性的改造方案并加以实施,通过催化汽油加氢精制、重汽油加氢精制及蜡油加氢裂化试验,结合长周期试验结果,验证了装置改造的效果,试验结果表明:通过对尾气排放方式等方面进行改造,装置功能得以提升,不仅可以满足在低压、低氢气流量下加氢试验的要求,同时提高了装置长周期运转的可靠性,此外,装置的灵活性得到大幅提升。根据试验装置实际情况,结合科研工作的需要,对试验装置存在问题进行认真分析,大胆改造,可以更好地服务于科研。     

Determination of flexibility of beam-to-column connectors used in thin walled cold-formed steel pallet racking systems

This paper describes a new test to determine flexibility of beam-to-column connectors used in conventional pallet racking systems. In this study, two different ways were used to find the flexibility of a connector. The connector developed was tested using the conventional cantilever method [Bajoria, KM. Three dimensional progressive collapse of warehouse racking, PhD Thesis, University of Cambridge, UK 1986], and then also using a newly proposed double cantilever method. To verify the results obtained from both the tests, a full scale frame test was carried out. In the double cantilever test the connector is subjected to three types of forces namely moment, shear and the axial pull by the beams, thereby giving behavior close to practical usage of connectors. Non-linear finite element analysis of both the tests and also of the full scale test were carried out using ANSYS [ANSYS 7.0—User's Manual, ANSYS Inc., 2005] software. The results obtained from the double cantilever test were found to match well with the full scale frame test. The experimental results and the finite element results are compared in this paper.     

走向松弛的限定--浅议新开发城区的街道城市设计

该文讨论了城市街道复合的功能及其半独立存在和半被动构成两种特殊性质,并以开发状态为依据,将城市街道分为已开发城区街道和新开发城区街道两种类型,归纳分析了业已得到广泛应用的面向已开发城区街道的城市设计的典型模式,并指出此种典型模式在应用于新开发城区街道时,所遇到的设计过程困境和实施过程困境,然后,提出针对新开发城区街道的城市设计,应以强化规划设计弹性为导向进行规划思想和技术方法的双重革新,文章最后以余姚市南雷南路城市设计为例,介绍了以规划设计弹性为导向的新开发城区街道城市设计.     

2-D analysis of circular tunnel against earthquake loading

The use of underground structures such as tunnel for subways, highways, material storage, and sewage and water transport is increasing in developed countries. The safety of these facilities during operation in areas with seismic activities such as in Japan, Taiwan and Turkey in recent earthquakes has been questioned. Dynamic effects on these structures are in the form of deformations that they experience during earthquakes. In this paper, first latest methods on the subject are reviewed and then the interaction between the ground and tunnel lining during earthquake excitation is investigated by a finite difference computer program (CA2). Analysis show that a good agreement between analytical closed form and numerical solutions exist. According to the results obtained in this study some practical suggestion for using closed form solution are also given.     

Numerical analysis of piping elbows for in-plane bending and internal pressure

This work presents the development of two different finite piping elbow elements with two nodal tubular sections for mechanical analysis. The formulation is based on thin shell displacement theory, where the displacement is based on high-order polynomial or trigonometric functions for rigid-beam displacement, and uses Fourier series to model warping and ovalization phenomena of cross-tubular section. To model the internal pressure effect an additional formulation is used in the elementary stiffness matrix definition. Elbows attached to nozzle or straight pipes produce a stiffening effect due to the restraint of ovalization provided by the adjacent components. When submitted to any efforts, the excessive oval shape may reduce the structural resistance and can lead to structural collapse. For design tubular systems it is also important to consider the internal-pressure effect, given its effect on the reduction of the pipe flexibility. Some conclusions and examples are compared with results produced by other authors.     

Problem-Solving Base Building under Uncertainty and Ambiguity: Multiple-Case Study on an Airport Expansion Program

This multiple-case study induces alternative strategies to coordinate the overlap of tasks to detail and physically execute base building with tasks to conceptualize the business-critical fit out. Base-building subsystems provide service space for occupancy, whereas fit-out subsystems make the space functional. Our empirical findings on problem-solving base-building design under uncertainty and ambiguity stem from a number of projects in an airport expansion program. They suggest that base-building subsystems show low sensitivity to incremental changes in fit out as their definitions are seldom optimized to eliminate slack. Yet, base-building subsystems show high sensitivity to radical changes in fit out when the architectures of the two subsystems are integral to one another. Three strategies for problem-solving base building stand out: (1) iterate design when preliminary information about fit out is ambiguous, or precise but unstable; (2) physically decouple the architectures of base building and fit out; and (3) design buffers in base building when preliminary information about fit out lacks precision but it is not ambiguous. These buffers can be designed out if uncertainties in fit out resolve favorably before starting the physical execution for base building.     

The theoretical rationale for a multinationality-performance relationship

Abstract and Key Results