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Different Engineering applications require dealing with improper integral on unbounded domains (improper integrals of the first kind). The classical way for solving these integrals is by means of elementary Calculus (antiderivatives and limit computations) or using numerical approaches. In both situations different problems can arise. For example: the non-existence of antiderivative, the corresponding limit does not exist or integrals depending on parameters which complicate the use of numerical approaches. In order to solve this situation, Advanced Calculus techniques, such as Laplace or Fourier Transforms and the Residue Theorem can be applied. A brief review of the corresponding theoretical frame is included in this paper. Computer Algebra Systems ( Cas ) are pieces of software that allow symbolic computations. Nowadays, there are many Cas in the market with an increasing level of sophistication which make them a very powerful tool in Engineering. In this paper, a brief review on the history of Cas evolution is introduced. In this work, some Advanced Calculus techniques for computing improper integrals of the first kind which cannot be solved with standard procedures are described. These techniques could be easily integrated in almost every Cas . However, we have detected some lacks of these techniques in many widely used Cas . In this paper, some tests involving improper integrals have been developed. These tests have been used to check the capabilities of some Cas and the results have provided a classification of the Cas with respect to this field. One of the main contributions in this work is the generation of different rules to compute improper integrals of the first kind. The rules have been classified in specific rules (those coming from the tests) and general rules (those coming from theoretical frames and generalizations of the specific rules). These rules are easy to include in a Cas increasing the facilities of the Cas in the field of improper integral computation. [ABSTRACT FROM AUTHOR]

• The distribution characteristics of CaS in the radial direction of the hearth were analyzed. • The formation mechanism and migration process of CaS in the hearth were analyzed. • The interface reaction between slag and coke is the main source of CaS formation in the furnace hearth. As the main occurrence form of sulfur element in blast furnace hearth, high content of CaS within the blast furnace hearth have a certain impact on low-carbon smelting of blast furnace. In this paper, the micro-morphology and distribution of CaS in the hearth area are studied by scanning electron microscopy and industrial CT, and the formation process of CaS in the deadman is clarified by drilling core samples of residual iron in the hearth of 3200 m3 blast furnace in China. The research results indicate that CaS in the hearth is mainly formed by slag-coke interface reaction and slag-iron interface reaction. Based on an analysis of the relative difficulty of these two pathways, it was observed that CaS is more readily generated through the slag-coke interface reaction. Based on the analysis of the difficulty of the two generation paths, it is found that CaS in the blast furnace hearth is more easily generated through slag coke interface reaction. The CaS particles generated in the hearth take the slag as the growth matrix, and with the flow of slag and iron and the renewal of the deadman coke, they are finally enriched and precipitated in the edge area of the deadman in the form of agglomerates. Based on the formation mechanism of CaS in the hearth, it is analyzed that the formation of CaS aggregates in the hearth is mainly affected by three factors: sulfur load, slag basicity and hearth temperature. This study provides a certain theoretical reference and guidance for steel enterprises aiming to reduce fuel consumption and achieve green production practices. [ABSTRACT FROM AUTHOR]

Organizations are increasingly looking to trusted data to drive their decision making process. Trusted data has a clear, defined and consistent quality which meets the expectations of the user. Data infrastructures which produce trusted data and provide organizations with the capability to make the right decisions at the right time are socio-technical networks, consisting of technical infrastructures and actor networks, and as such they are often complex and adaptive. Critical issues, challenges, and dilemmas can be identified while looking at data infrastructures as a socio-technical systems. This paper explores conditions and factors for effective and sustainable development of data infrastructures in organizations and suggests that the inherent complexity of data infrastructures requires a multi-faceted way of data governance. Several predefined components of data infrastructures which contain the behavior of agents through various coordination mechanisms have been developed to model the effect of data governance on data infrastructures. These components can be further customized to model an empirical situation more closely. Finally, the paper suggests institutionalization of data governance within an organization as a unifying concept towards the effectiveness and sustainability of data infrastructures, recognizing their inherent complexities. The approach is illustrated with a case study in the asset management domain. [ABSTRACT FROM AUTHOR]

This paper addresses approaches to handle System Engineering and Integration (SE&I) activities associated with complex adaptive systems (CAS). In this paper we will talk about two major initiatives within advanced SEI capabilities that address risk driven engineering and integration challenges posed from a CAS like environment. The first initiative is based on the use of an advanced Conops development and modelling approach implemented through a CONOPS Simulator concept. Next initiative outlines advanced applications of Reference Architectures (RA's) as it relates to system design activities within a CAS environment. These initiatives are applied as the foundation for a risk adverse design within CAS Enterprises. [ABSTRACT FROM AUTHOR]

More and more asset management organizations are relying on trusted data to drive their decision making process. Yet little systematic research has been performed regarding the generation of trusted data. Trusted data has a clear, defined and consistent quality which meets the expectations of the user. The aim of the research presented in this paper is to develop a conceptual model to support asset management organizations with regards to their development of data infrastructures which produce trusted data and provide organizations with the capability to make the right decisions at the right time. The autonomous characteristics of agent-based systems and process orientation of discrete-event simulation are combined in our conceptual model. In this way both the autonomous social behavior of organizations and their business processes can be modelled. Several predefined components containing the behavior of agents through various coordination mechanisms have been developed. These components can be further customized to model an empirical situation more closely. The approach is illustrated with a case study in the asset management domain. [ABSTRACT FROM AUTHOR]

Thermal barrier coatings (TBC) in service are prone to the attack by molten calcium–magnesium aluminosilicates (CMAS) resulting from the ingestion of siliceous minerals (dust, sand, volcanic ash) by the aeroengines. As CMAS deposits observed on ex-service parts present complex and highly variable compositions, progress in the understanding of the interaction mechanism between CMAS and TBC has been mostly obtained during laboratory experiments using simplified CMAS compositions. This paper consists in a microstructural characterization of the isothermal chemical interaction between a synthetic calcium aluminosilicate (CAS) and a standard 8YPSZ EB-PVD coating deposited on alumina substrates. The chosen CAS is the lowest melting temperature eutectic (1170°C) in the ternary (CaO–Al2O3–SiO2) system and it is prepared as a glass. The evolution of the reaction zone morphology and chemistry is studied after 1200°C treatments from 15min to 100h. The CAS/TBC interaction is governed by the classical mechanism of dissolution/reprecipitation with formation of Y-lean zirconia and Ca2Zr(Y)Si4O12. Ca2Zr(Y)Si4O12 formation induces local variation in the CAS composition leading to CaAl2Si2O8 (anorthite) precipitation. Y2O3 depletion in the YSZ regions infiltrated by CAS is attested using X-ray compositional mapping and the association of EDS and EBSD clearly illustrates that the morphological transformation from porous initial YSZ to dense globular Y-lean YSZ is associated with the structural transformation from initial tetragonal t′ to tetragonal Y-lean zirconia transforming into monoclinic during cooling. The degradation of the TBC columns increases with the duration of the 1200°C heat-treatment. The interfacial Ca2Zr(Y)Si4O12 phase forms on an increasing amount of columns and is finally observed on all the columns. Interfacial phase formation is discussed and compared to other phase assemblages reported in the literature. [ABSTRACT FROM AUTHOR]

Abstract: The superhydrophobic spherical-like α-FeOOH films on the wood surface was obtained from ferric sulfate and urea by a hydrothermal reaction process followed by a self-assembly of Octadecyltrichlorosilane (OTS) monolayer. The microstructure, chemical state and composition of the products were observed by scanning electron microscope (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and Energy disperse X-ray analysis (EDX). The hydrophobic property of the treated samples was described by static water contact angles (CAs) and sliding water contact angles (SA) measurement. The stability under ambient condition and durability for corrosive liquid of the surperhydrophobic samples were also investigated in this paper. An analytical characterization revealed that the spherical-like α-FeOOH films with micro–nano structure uniformly deposited on the wood surface and OTS molecules combined with α-FeOOH films. The water contact angle of the as-prepared samples reached as high as 158° and the sliding angle was about 4°. The prepared superhydrophobic wood surface still maintained the superhydrophobic property when stored under ambient condition for 3 months or immersed in a sodium hydroxide solution of pH 12 and a hydrochloric acid solution of pH 2 for 2h at room temperature. [Copyright &y& Elsevier]

Abstract: Software engineers require systematic approaches in order to develop complex large-scale systems and to integrate and migrate existing solutions. Also they need techniques to improve the software reliability, maintainability, performance and dependability, and methodological support to manage the development process effectively and productively. Computer algebra systems are software packages, usually Object-oriented, which are used in manipulation of mathematical formulas. The primary goal of a Computer Algebra System (CAS) is to automate tedious and sometimes difficult algebraic manipulation tasks. The specific uses and capabilities of these systems vary greatly from one system to another. Some of them include facilities for graphing equations and provide a programming language for the user to define their own procedures. In this paper we are going to examine new design strategies and techniques. [Copyright &y& Elsevier]

Currently, computer-assisted surgery (CAS) systems like surgical robots and navigation systems are established in the OR. The goal of this paper is to quantify to what extent experts perceive their CAS system is adapted to the needs of daily clinical routine. A questionnaire was distributed via Internet to CAS experts worldwide. The clinical usability of CAS systems is evaluated in terms of reliability, learnability and user satisfaction. In period of last 24 months (from October 2001 to October 2003), 62 responses were received regarding 21 different CAS systems. In general, the clinical usability of CAS systems in daily routine work was rated to be low, which suggested that the ergonomic system design should be improved in order to assure clinical usability and reduce the incidence and impact of human error. [Copyright &y& Elsevier]

In this paper, we discuss physically based approaches to the modeling of deformable soft tissue for the long-term prediction of patient''s postoperative appearance in cranio-maxillofacial (CMF) surgery simulations. Since the biomechanical properties of living tissues and their numerical modeling are, in general, very complex, our focus is on the investigation of qualitative and quantitative differences between different physical models for the range of boundary value problems (BVP) typically appear in cranio-maxillofacial surgery. [Copyright &y& Elsevier]

In global efforts to reduce harmful greenhouse gas emissions from the transportation sector, novel bio-hybrid liquid fuels from renewable energy and carbon sources can be a major form of energy for future propulsion systems due to their high energy density. A fundamental understanding of the spray and mixing performance of the new fuel candidates in combustion systems is necessary to design and develop the fuels for advanced combustion concepts. In the fuel design process, a large number of candidates is required to be screened to arrive at potential fuels for further detailed investigations. For such a screening process, three-dimensional (3D) simulation models are computationally too expensive and hence unfeasible. Therefore, in this paper, we present a fast, reduced-order model for inert sprays. The model is based on the cross-sectionally averaged spray (CAS) model derived by Wan (1997) from 3D multiphase equations. The original model was first tested against a wide range of conditions and different fuels. The discrepancies between the CAS model and experimental data are addressed by integrating state-of-the-art breakup and evaporation models. In addition, a transport equation for vapor mass fraction is proposed, which is important for evaporation modeling. Furthermore, the model is extended to consider polydisperse droplets by modeling the droplet size distribution by commonly used presumed probability density functions, such as Rosin–Rammler, lognormal, and gamma distributions. The improved CAS model is capable of predicting trends in the macroscopic spray characteristics for a wide range of conditions and fuels. The computational cost of the CAS model is lower than the 3D simulation methods by up to 6 orders of magnitude depending on the method. This enables the model to be used not only for the rapid screening of novel fuel candidates, but also for other applications, where reduced-order modeling is useful. • A fast, reduced-order CAS model is presented for transient inert sprays. • Latest droplet breakup, evaporation models and vapor transport improve predictions. • Trends of spray penetration are captured for a wide range of conditions and fuels. • Information on the droplet size distribution can be obtained along the spray axis. • Computational costs are lower by orders of magnitude for CAS model vs. 3D methods. [ABSTRACT FROM AUTHOR]

Although a large amount of past research has studied the measurement of institutional research and development (R&D) efficiency, there has been limited dynamic empirical investigation of this topic. This study differs from previous studies in its consideration of R&D capital stock, which is defined as a carry-over activity between two consecutive periods. To further test high-tech institutes' R&D performance in the pre-reform and post-reform periods, we evaluate a panel of 29 high-tech institutes of the Chinese Academy of Sciences (CAS) for 2011–2017 with a dynamic slacks-based measure. (a) The empirical value of the average overall efficiency is 0.5559, and the clustering analysis shows that institutes operating above the average overall efficiency level follow an increasing and then decreasing trend, while those operating below the average overall efficiency level follow a decreasing and then increasing trend. (b) The efficiency of low-performing institutes has increased from 0.2259 in the pre-reform period to 0.2727 in the post-reform period, which does not reflect the efficiency improvements of high-performing institutes. (c) High-tech institutes selected as pilot institutes have an average efficiency level of 0.6524, which is higher than that of non-pilot institutes (0.4765), indicating the benchmarking effect of pilots. (d) The types of pilot institutes can be ordered as follows: feature institutes > centres of excellence > innovative academies. (e) The total-factor input efficiency level has decreased in the post-reform period. Only the total-factor efficiency of high-quality papers has increased in the post-reform period (by 0.0094). • We concentrated on the dynamic performance evaluation of high-tech institutes in CAS. • We compared the R&D efficiency in the pre-reform and post-reform period. • We tested the difference between high-performance institutes and low-performance institutes in investment structures. • Pilots are more efficient than the non-pilots, indicating the benchmarking effect of pilot institutes. • Regional differences still exist in the development of high-tech institutes in China. [ABSTRACT FROM AUTHOR]