Reactive moulding process modelling: structural analysis of thermoset insulated electrical components

Electrical equipment for medium and high voltage is manufactured using reactive moulding process. During mould filling, air bubbles or weld-lines can appear which may be a huge problem for electrical insulation devices. Moreover, the use of thermoset materials induces delamination due to the resin’s shrinkage. Product development delays can be reduced using numerical tools to simulate part forming process. In this paper, we present a three dimensional finite element analysis of the filling and curing stages of reactive moulding process. During the first stage, flow computation takes into account heat transfer and the curing reaction according to appropriate models. In the curing phase, the evolution of the degree of cure is coupled with an evolution model of the glass transition temperature. Taking in account his coupling phenomenon permits the computation of a more realistic curing kinetic and modelling of the slowdown at vitrification. The thermal field prediction is then more accurate. To validate this approach, experiments were performed. A comparison with computational results shows a good agreement in filling and temperature evolution inside the cavity.

Functional and structural analyses of behavior: Approaches leading to reduced use of punishment procedures?

ABSTRACTThis work focuses on developing a design methodology for reliable control system instrumentation. This methodology aims at optimising the instrumentation using a dependability criterion based on reliability and cost. The design methodology is primarily based on three processes: structural analysis of the relations between different variables and physical quantities that govern the system; evaluation of the reliability of the main mission of the control system instrumentation using the structural links, which depends on a graphical tree representation of the system in the design phase; and optimisation, which allows us to determine the best architecture for instrumentation. This methodology is illustrated for the design of an electric vehicle.

Intracellular processes are cascades of biochemical reactions, triggered in response to various types of stimuli. Mathematical models describing their dynamics have become increasingly popular in recent years, as tools supporting experimental work in analysis of pathways and regulatory networks. Not only do they provide insights into general properties of these systems, but also help in specific tasks, such as search for drug molecular targets or treatment protocols. Different tools and methods are used to model complex biological systems. In this work, we focus on ordinary differential equations (ODEs) and Petri nets. We consider specific methods of analysis of such models, i.e., sensitivity analysis (SA) and significance analysis. So far, they have been applied separately, with different goals. In this paper, we show that they can complement each other, combining the sensitivity of ODE models and the significance analysis of Petri nets. The former is used to find parameters, whose change results in the greatest quantitative and qualitative changes in the model response, while the latter is a structural analysis and allows indicating the most important subprocesses in terms of information flow in Petri net. Ultimately, both methods facilitate finding the essential processes in a given signaling pathway or regulatory network and may be used to support medical therapy development. In the paper, the use of dual modeling is illustrated with an example of ATM/p53/NF-kappaB pathway. Each method was applied to analyze this system, resulting in finding different subsets of important processes that might be prospective targets for changing this system behavior. While some of the processes were indicated in each of the approaches, others were found by one method only and would be missed if only that method was applied. This leads to the conclusion about the complementarity of the methods under investigation. The dual modeling approach of comprehensive structural and parametric analysis yields results that would not be possible if these two modeling approaches were applied separately. The combined approach, proposed in this paper, facilitates finding not only key processes, with which significant parameters are associated, but also significant modules, corresponding to subsystems of regulatory networks. The results provide broader insight into therapy targets in diseases in which the natural control of intracellular processes is disturbed, leading to the development of more effective therapies in medicine.

Assessing China's “developing a water-saving society” policy at a river basin level: A structural decomposition analysis approach

Active bending is an increasingly popular construction technique that uses elastically bent structural members to form complex curved shapes. The design and analysis of bending-active structures requires an accurate simulation of the bending process, which is often complicated by the occurrence of large displacements. In this article, we propose to combine a previously developed implicit dynamic relaxation method with co-rotational beam elements to obtain a fast and accurate method for form-finding and analysis of bending-active structures. This approach is applied to four test cases. Implicit dynamic relaxation is compared to the classic Newton–Raphson method and conventional dynamic relaxation. The results show that the proposed implicit dynamic relaxation approach can be stabilized intuitively by changing the time step and damping ratio, making it more stable than the classic Newton–Raphson method. Moreover, the proposed approach converges fast compared to the conventional dynamic relaxation: the total computation time is considerably lower, even though the computation time per iteration is higher. Finally, a high accuracy is achieved due to the use of co-rotational beam elements. The combination of high accuracy and low computation time makes this approach well-suited for both form-finding and analysis of bending-active structures.

Gaucher's disease (GD) is a genetic disorder in which glucocerebroside accumulates in cells and specific organs. It is broadly classified into type I, type II and type III. Patients with GD are at high risk of Parkinson's disease (PD), and the clinical and pathological presentation of GD patients with PD is almost identical to idiopathic PD. Several experimental models like cell culture, animal models, and transgenic mice models were used to understand the molecular mechanism behind GD and PD association; however, such mechanism remains unclear. In this context, based on literature reports, we identified the most common mutations K198T, E326K, T369M, N370S, V394L, D409H, L444P, and R496H, in the Glucosylceramidase (GBA) protein that are known to cause GD1, and represent a risk of developing PD. However, to date, no computational analyses have designed to elucidate the potential functional role of GD mutations with increased risk of PD. The present computational pipeline allows us to understand the structural and functional significance of these GBA mutations with PD. Based on the published data, the most common and severe mutations were E326K, N370S, and L444P, which further selected for our computational analysis. PredictSNP and iStable servers predicted L444P mutant to be the most deleterious and responsible for the protein destabilization, followed by the N370S mutation. Further, we used the structural analysis and molecular dynamics approach to compare the most frequent deleterious mutations (N370S and L444P) with the mild mutation E326K. The structural analysis demonstrated that the location of E326K and N370S in the alpha helix region of the protein whereas the mutant L444P was in the starting region of the beta sheet, which might explain the predicted pathogenicity level and destabilization effect of the L444P mutant. Finally, Molecular Dynamics (MD) at 50ns showed the highest deviation and fluctuation pattern in the L444P mutant compared to the two mutants E326K and N370S and the native protein. This was consistent with more loss of intramolecular hydrogen bonds and less compaction of the radius of gyration in the L444P mutant. The proposed study is anticipated to serve as a potential platform to understand the mechanism of the association between GD and PD, and might facilitate the process of drug discovery against both GD and PD.

Subject. The article considers the development of the institution of bankruptcy in the context of the emerging legal environment in this area. Objectives. The focus is to study the development of relations in the bankruptcy sphere in the Russian Federation that relate to inefficient procedures aimed at the financial recovery of business entities, and to formulate the main directions for further changes in the legal regulation of this area. Methods. The study employs research methods, like logical and structural analysis, systems and functional approach, the formal legal method. Results. The paper reveals the essence, specific features and legal regulation of bankruptcy, assesses the regulatory enforcement based on the existing law on insolvency, formulates the key problems of the law enforcement practice of business entities that has been formed over the past 20 years, defines further directions of changes in the legal regulation of bankruptcy relations in the Russian Federation. Conclusions. Changing the approaches to the current bankruptcy system in favor of expanding the application of rehabilitation procedures for restoring the solvency of debtors will enable to support businesses that are in difficult financial situation. This will result in preservation of employment, increased tax revenues to budgets at various levels, improved competitiveness of Russian businesses. The findings may be useful in terms of theory, for the study of issues relating to the concept, essence and legal regulation of the institution of bankruptcy in the Russian Federation, and in practice, for developing proposals to improve regulations in this sphere.

Purpose — Analysis of nonprismatic members has received a great deal attention from designers and engineers due to their ability in satisfaction of architectural and aesthetic necessities. Using these structural members in complex structures such as aircrafts, turbine blades and space vehicles, exact static and dynamic analyses of these members become more significant. Based on structural/mechanical principles, the purpose of this paper is to present a new method to evaluate exact structural matrices for nonprismatic Euler‐Bernoulli beam elements. Design/methodology/approach — Through introducing the concept of basic displacement functions (BDFs), it is shown that exact shape functions are derived in terms of BDFs. BDFs and their derivatives have structural interpretations; therefore, they are obtained via application of flexibility method. Unlike the conventional methods, which are almost categorized as displacement‐based methods, the flexibility basis of the method ensures the true satisfaction of equilibrium equations at any interior point of the element. Findings — The exact shape functions and consequently structural matrices are derived for general nonprismatic beam elements. Numerical examples are carried out to determine static deflection and natural frequencies, and the results are highly competent with the other methods in literature. Research limitations/implications — The method can be extended to structural analysis of curved beams, plates and shells as well. Moreover, it is possible to derive exact dynamic shape functions via BDFs by solving the governing equation for transverse vibration of beams. Theoretically, the method faces limitation in analysis of nonprismatic beams that converge to a point where cross‐sectional area and moment of inertia are equal to zero. Practical implications — The development of this idea, i.e. BDFs seems to lead to promotive novel approaches for structural analysis and could be a breaking point for developing new elements for plates and shells as it was shown for beam elements. Originality/value — The paper's introduction of special functions, namely BDFs and their application, in both static and dynamic analyses of structures, could be a breaking point in analysis procedures.

A cellular framework for structural analysis and optimization

ABSTRACTModern methodologies for the analysis of composite structures are demanded to satisfy the accuracy requirements at different scales, from micro to macro and possibly in a global/local sense. In this domain, the present paper proposes a hierarchical, component-wise approach for the linear static analysis of layered structures. By employing the Carrera Unified Formulation and a variational statement, finite element arrays of refined beam models are expressed in terms of fundamental nuclei. Legendre-based polynomials are utilized to implement, in a hierarchical form, higher-order beam kinematics. Also, curved cross-section geometries are formulated in a correct and consistent manner through mapping blending functions. Mapping and refined kinematics beam models are, thus, inherently combined to give the component-wise method, according to which each component of the structure (e.g., layer, fibers, and matrix) is modeled independently and with its geometric and mechanical characteristics. This approach is demonstrated to provide enhanced accuracy for the analysis of composite structures, from layer scale to fiber-matrix level, but still with low computational costs.

This paper investigates the collaboration of three numeral recognition techniques that will detect unconstrained handwritten numerals. Our research focuses on a feature-based approach, a method using eigenimages, and a structural analysis approach using wavelet transforms. These approaches will generate an estimate for the input numeral and a corresponding confidence value that in combination, yield a final decision. This paper shows that each individual method performs with a detection rate of better than 80%, and by combining the detection strategies, detection rates up to 94% are observed.

This study aims to determine the strategic factors and their relationship in improving the level of guest satisfaction at favehotel Gatot Subroto Jakarta. This study aims to determine the strategic factors and their relationship in increasing guest satisfaction at Favehotel Gatot Subroto Jakarta. This study uses a structural analysis approach. The analytical method uses MICMAC to identify the most influential variables and their relationship to guest satisfaction at Favehotel Gatot Subroto Jakarta. The results of the analysis that embody the typology of strategic variables based on the strength of influence found 19 strategic variables classified in 4 quadrants, namely: (1) Dominant variables consist of: 3 variables, 2 price dimensions and 1 location dimension, (2) Key variables consist of: 7 variables (2 dimensions of product, 2 dimensions of facilities, 2 dimensions of atmosphere, and 1 dimension of promotion). (3) The output variable consists of: 1 variable (1 service dimension). (4) Autonomous variables consist of: 8 variables (3 service dimensions, 2 promotion dimensions, 1 location dimension, 1 facility dimension, 1 location dimension). The results of this study indicate various sources of information for policy makers in increasing guest satisfaction at Favehotel Gatot Subroto Jakarta.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTFluidized catalytic cracker control. A structural analysis approachJoseph A. Bromley and Thomas J. WardCite this: Ind. Eng. Chem. Proc. Des. Dev. 1981, 20, 1, 74–81Publication Date (Print):January 1, 1981Publication History Published online1 May 2002Published inissue 1 January 1981https://pubs.acs.org/doi/10.1021/i200012a011https://doi.org/10.1021/i200012a011research-articleACS PublicationsRequest reuse permissionsArticle Views144Altmetric-Citations7LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access options Get e-Alerts

The problem we address in this paper is that of detecting flaws in woven textile fabrics. This task is currently performed by human inspectors with a maximum detection rate of only about 80%. An Automated Visual Inspection System (AVIS) is potentially a more reliable, objective, time and cost effective solution. Using computer vision it detects irregularities in homogeneously structured images of textile fabrics. However, its successful performance is largely dependent of the choice of an accurate and robust texture analysis algorithm. The technique of blob detection described in this paper is representative of a structural texture analysis approach and it accounts for aspects of the human visual system (HVS) in detecting large varieties of textile flaws. Measures of texture discrimination based on psychophysical experiments are used to indicate the levels of perceivable differences in blob attributes indicating the presence of defects. Defects are detected by observing a threshold of acceptable differences in the properties of blobs based on human perception.