The effect of slip variability on earthquake slip-length scaling

There has been debate on whether average slip D in long ruptures should scale with rupture length L, or with rupture width W. This scaling discussion is equivalent to asking whether average stress drop Δσ, which is sometimes considered an intrinsic frictional property of a fault, is approximately constant over a wide range of earthquake sizes. In this paper, we examine slip-length scaling relations using a simplified 1-D model of spatially heterogeneous slip. The spatially heterogeneous slip is characterized by a stochastic function with a Fourier spectrum that decays as k^(−α), where k is the wavenumber and α is a parameter that describes the spatial smoothness of slip. We adopt the simple rule that an individual earthquake rupture consists of only one spatially continuous segment of slip (i.e. earthquakes are not generally separable into multiple disconnected segments of slip). In this model, the slip-length scaling relation is intimately related to the spatial heterogeneity of the slip; linear scaling of average slip with rupture length only occurs when α is about 1.5, which is a relatively smooth spatial distribution of slip. We investigate suites of simulated ruptures with different smoothness, and we show that faults with large slip heterogeneity tend to have higher D/L ratios than those with spatially smooth slip. The model also predicts that rougher faults tend to generate larger numbers of small earthquakes, whereas smooth faults may have a uniform size distribution of earthquakes. This simple 1-D fault model suggests that some aspects of stress drop scaling are a consequence of whatever is responsible for the spatial heterogeneity of slip in earthquakes

Study of Internal Strains Developed in Concrete Decks at Early Ages in Steel Continuous Bridges

The Arkansas Department of Transportation (ARDOT) has identified bridge deck cracking shortly after concrete decks are placed and prior to applying traffic loads. Previous researchers have confirmed improper construction practices and design methods can lead to deck cracking. Currently, many contractors throughout Arkansas are using continuous deck pours. This construction approach may restrict the concrete slab from movement during early age shrinkage, causing tensile stresses to develop. The final stresses at the end of construction must be lower than the concrete tensile strength, if not cracking issues will develop. Eventually, these cracks may enlarge due to service load stresses and environmental damage. A nation-wide Department of Transportation (US DOTs) survey was performed to investigate the early age cracking extensiveness level in other state’s bridges and what corrections, if any, they have made to address this problem. Additionally, Arkansas bridges with early age cracking were visited to examine any trends and inform instrumentation for bridge testing. A bridge deck was instrumented with 32 vibrating wire strain gauges prior to concrete placement to investigate strain and temperature changes in the first 14 days. Eurocode and ACI approximations for concrete mechanical properties were compared to field measured data for improving the understanding of an early age concrete deck behavior in a continuous steel bridge. Stress analysis study through the span length of bridge 030428 detected some locations prone to concrete cracking due to the variability of concrete mechanical properties and stress developed in the concrete deck. This thesis describes the results of this monitoring and anything that can be learned about formation of concrete stresses in continuous concrete bridge deck pours

Customer Journeys: A Systematic Literature Review

Purpose – Customer journeys has become an increasingly important topic in service management and design. The study reviews customer journey terminology and approaches within the research literature prior to 2013, mainly from the fields of design, management, and marketing. Design/methodology/approach - The study was conducted as a systematic literature review. Searches in Google Scholar, Scopus, Web of Knowledge, ACM Digital Library, and ScienceDirect identified 45 papers for analysis. The papers were analysed with respect to customer journey terminology and approaches, the relation to customer experience, the referenced background, and the use of visualizations. Findings – Across the reviewed literature, customer journeys are described not only as a means to take the viewpoint of the customer, but also to reach insight into their experiences. A rich and at times incoherent customer journey terminology is analysed and discussed, as are two emerging customer journey approaches: customer journey mapping (analysis of a service process "as is") and customer journey proposition (generative activities leading towards a possible service "to be"). Research limitations/implications – The review is limited to analysing and making claims on research papers that explicitly apply the term customer journey. In most of the reviewed papers, customer journeys are not the main object of interest but are discussed as one of several topics. Practical implications - A nuanced discussion of customer journey terminology and approaches is provided, supporting the practical application of a customer journey perspective. Originality/value - The review contributes a needed common basis for future customer journey research and practice.acceptedVersio

Decision-making and problem-solving methods in automation technology

The state of the art in the automation of decision making and problem solving is reviewed. The information upon which the report is based was derived from literature searches, visits to university and government laboratories performing basic research in the area, and a 1980 Langley Research Center sponsored conferences on the subject. It is the contention of the authors that the technology in this area is being generated by research primarily in the three disciplines of Artificial Intelligence, Control Theory, and Operations Research. Under the assumption that the state of the art in decision making and problem solving is reflected in the problems being solved, specific problems and methods of their solution are often discussed to elucidate particular aspects of the subject. Synopses of the following major topic areas comprise most of the report: (1) detection and recognition; (2) planning; and scheduling; (3) learning; (4) theorem proving; (5) distributed systems; (6) knowledge bases; (7) search; (8) heuristics; and (9) evolutionary programming

El diseño va al colegio: Oportunidades de Aplicación del Proceso de Diseño en la Educación Escolar Chilena [Design goes to school: Opportunities to apply the design process in Chilean school education]

El estado de desarrollo económico del país requiere de la formación de capital humano que domine habilidades de pensamiento superior, como pensamiento analítico, resolución creativa de problemas y colaboración; todas competencias que se despliegan ampliamente durante el proceso de diseño. A nivel escolar, esto no se resuelve solo con cambios curriculares, sino que requiere de la capacitación de profesores. Hay evidencia empírica de la aplicación en el extranjero de design thinking en el ámbito educativo, entre estudiantes y profesores. Sin embargo, su importación puede no resultar efectiva dadas las diferencias culturales y particularidades del sistema educacional chileno. Este proyecto busca identificar oportunidades para transferir el pensamiento de diseño a la educación chilena, así como desarrollar y testear un programa de capacitación en conjunto con profesores y directivos de colegios, de distintos niveles de dependencia. Para esto se diseñó una intervención -en modalidad de programa de capacitación-, que fue realizada por 20 profesores (cuatro de ellos con cargo directivo y/o administrativo). También, se generó una batería de recursos que permitieron recoger, sistematizar y analizar la información (ejercicios prácticos, cuestionarios, entrevistas, grupos focales, matrices, etcétera). En este artículo, se presentan los resultados preliminares del proyecto “developing human capital for 21st century economies: introducing design thinking to chilean schools”, que ha permitido identificar problemáticas en el ámbito curricular, de convivencia escolar y a nivel organizacional. Estas fueron abordadas por los profesores, aplicando herramientas entregadas en la capacitación. [The state of economic development of the country requires the formation of human capital that dominate higher-order thinking skills, as analytical thinking, creative problem solving and collaboration; all skills deployed extensively during the design process. At the school level, this is not resolved only with curricular changes, but requires teacher training and support. There is empirical evidence of the international application of design thinking in the field of education among students and teachers. However, directly importing such models may not be effective given the cultural differences and particularities of the chilean educational system. This project seeks to identify opportunities for the transfer of design thinking to chilean education, as well as develop and test a training program in conjunction with professors and directors of schools of various levels of dependency. An intervention was designed—in a training program mode—which was experienced by 20 teachers (four of them with managerial and/or administrative positions). A range of resources was used to collect, systematize and analyze the information (practical exercises, questionnaires, interviews, focus groups, arrays, etc.). In this article, we present the preliminary results of the project "developing human capital for 21st century economies: introducing design thinking to chilean schools", which has allowed us to identify problems in the field of curricula, school atmosphere and at the organizational level. These problems were addressed as opportunities by the teachers, applying tools delivered in the training.

Integrating life cycle inventory and process design techniques for the early estimate of energy and material consumption data

Life cycle assessment (LCA) is a powerful tool to identify direct and indirect environmental burdens associated with products, processes and services. A critical phase of the LCA methodology is the collection of representative inventory data for the energy and material streams related to the production process. In the evaluation of new and emerging chemical processes, measured data are known only at laboratory scale and may have limited connection to the environmental footprint of the same process implemented at industrial scale. On the other hand, in the evaluation of processes already established at commercial scale, the availability of process data might be hampered by industrial confidentiality. In both cases, the integration of simple process design techniques in the LCA can contribute to overcome the lack of primary data, allowing a more correct quantification of the life cycle inventory. The present paper shows, through the review of case study examples, how simplified process design, modeling and simulation can support the LCA framework to provide a preliminary estimate of energy and material consumption data suitable for environmental assessment purposes. The discussed case studies illustrate the implementation of process design considerations to tackle availability issues of inventory data in different contexts. By evidencing the case-specific nature of the problem of preliminary conceptual process design, the study calls for a closer collaboration of process design experts and life cycle analysts in the green development of new products and processes

Development of Multifunctional Shape Memory Polymer and Shape Memory Polymer Composites

Shape memory polymers (SMPs) are an emerging class of active polymers that can be used on a wide range of reconfigurable structures and actuation devices. The present study comprehensively examines the unconstrained shape recovery abilities of an epoxy-based SMP. In doing so, epoxy based SMP is synthesized and thermo-mechanically characterized. Results show that the present SMP exhibits excellent shape recoveries under unconstraint conditions, for a range of fixing strains and temperatures. Additionally, the stress-strain behavior of the SMP is determined to be nonlinear, finite deformation at all regions. The strain energy based models have been used to capture the complicate stress-strain behavior and shape recovery process of the SMPs. Further SMP based composites are considered to obtain a smart material that is suitable for applications at both above and below the glass transition temperature of the polymer. A smart composite made of SMP and SMA would allow many design possibilities due to their controllable temperature-dependent mechanical properties. In this study, the shape memory composites (SMCs) are created by embedding SMA components (particles and fibers) into SMP matrices, which take advantage of the complementary properties of SMAs and SMPs. The SMA-particle and SMA-fiber reinforced SMP composites are designed through numerical simulations for different weight fractions of the SMA fillers were varied from 0-50%. Addition of SMA fillers significantly increased modulus across the temperature regimes while maintaining the large actuation strain. In addition to the simulations, SMA-Particle + SMP composites are synthesized and tested using DMA in compression. The obtained modulus results from the simulations for SMA-Particle + SMP composite is comparable with the experimentally determined results. However, since SMP matrix is not conductive these composites often require external stimuli such as external heaters which limit their applications. To overcome this limitation, multi-functional Shape memory polymer based composites are thus fabricated in the present study by embedding CNT fibers and Ni particles in SMP matrix that resulted in electrically conductive and thermally stable SMP based composites