Maintenance Policies for Multicomponent Systems: An Overview

1996 ◽  
pp. 117-136 ◽  
Author(s):  
Frank Van der Duyn Schouten
Keyword(s):  
Multicomponent Systems ◽  
Maintenance Policies

A standard for transmission electron spectroscopy

1978 ◽  
Vol 36 (1) ◽  
pp. 530-531 ◽  
Author(s):  
Dennis Maher ◽  
David Joy ◽  
Peggy Mochel
Keyword(s):  
Thin Films ◽  
Electron Spectroscopy ◽  
Host Lattice ◽  
Single Element ◽  
Multicomponent Systems ◽  
Transmission Electron ◽  
Major Interest ◽  
Standard Specimens ◽  
Forms Of Carbon ◽  
Electron Energy Loss

A variety of standard specimens is needed in order to systematically investigate the instrumentation, specimen, data reduction and quantitation variables in electron energy-loss spectroscopy (EELS). Pure single element specimens (e.g. various forms of carbon) have received considerable attention to date but certain elements of interest cannot be prepared directly as thin films. Since studies of the first and second row elements in two- or multicomponent systems will be of considerable importance in microanalysis using EELS, there is a need for convenient standards containing these species. For many investigations a standard should contain the desired element, or elements, homogeneously dispersed through a suitable matrix and at an accurately known concentration. These conditions may be met by the technique of implantation.Silicon was chosen as the host lattice since its principal ionization energies, EL23 = 98 eV and Ek = 1843 eV, are well removed from the K-edges of most elements of major interest such as boron (Ek = 188 eV), carbon (Ek = 283 eV), nitrogen (Ek = 400 eV) and oxygen (Ek = 532 eV).

Modeling of Multicomponent Systems

2011 ◽  
Vol 43 (1) ◽  
pp. 72-84 ◽  
Author(s):  
Boris A. Beletskiy
Keyword(s):  
Multicomponent Systems

Competitive hydrogenation of olefinic substrates in multicomponent systems

1978 ◽  
Vol 43 (9) ◽  
pp. 2387-2394 ◽  
Author(s):  
Libor Červený ◽  
Dana Plecháčová ◽  
Vlastimil Růžička
Keyword(s):  
Multicomponent Systems ◽  
Competitive Hydrogenation

Understanding mechanisms in the adsorption of lead and copper ions on chili seed waste in single and multicomponent systems: a combined experimental and computational study

2021 ◽  
Author(s):  
Angélica Forgionny ◽  
Nancy Y. Acelas ◽  
Raúl Ocampo-Pérez ◽  
Erika Padilla-Ortega ◽  
Roberto Leyva-Ramos ◽  
...  
Keyword(s):  
Copper Ions ◽  
Computational Study ◽  
Multicomponent Systems

Availability analysis and maintenance optimization for multiple failure mode systems considering imperfect repair

2021 ◽  
pp. 1748006X2110127
Author(s):  
Qingan Qiu ◽  
Baoliang Liu ◽  
Cong Lin ◽  
Jingjing Wang
Keyword(s):  
Failure Modes ◽  
Maintenance Cost ◽  
Imperfect Maintenance ◽  
Maintenance Policy ◽  
Cost Rate ◽  
Availability Analysis ◽  
Long Run ◽  
Optimal Maintenance ◽  
Maintenance Policies ◽  
Periodic Inspections

This paper studies the availability and optimal maintenance policies for systems subject to competing failure modes under continuous and periodic inspections. The repair time distribution and maintenance cost are both dependent on the failure modes. We investigate the instantaneous availability and the steady state availability of the system maintained through several imperfect repairs before a replacement is allowed. Analytical expressions for system availability under continuous and periodic inspections are derived respectively. The availability models are then utilized to obtain the optimal inspection and imperfect maintenance policy that minimizes the average long-run cost rate. A numerical example for Remote Power Feeding System is presented to demonstrate the application of the developed approach.

scholarly journals Applications of Supercritical Anti-Solvent Process in Preparation of Solid Multicomponent Systems

Pharmaceutics ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 475
Author(s):  
Guijin Liu ◽  
Junjian Li ◽  
Shiming Deng
Keyword(s):  
Solid State ◽  
Solid Dispersions ◽  
Crystal Form ◽  
Great Promise ◽  
Computational Techniques ◽  
Large Contribution ◽  
Continuous Manufacturing ◽  
Multicomponent Systems ◽  
On Line ◽  
Underlying Mechanisms

Solid multicomponent systems (SMS) are gaining an increasingly important role in the pharmaceutical industry, to improve the physicochemical properties of active pharmaceutical ingredients (APIs). In recent years, various processes have been employed for SMS manufacturing. Control of the particle solid-state properties, such as size, morphology, and crystal form is required to optimize the SMS formulation. By utilizing the unique and tunable properties of supercritical fluids, supercritical anti-solvent (SAS) process holds great promise for the manipulation of the solid-state properties of APIs. The SAS techniques have been developed from batch to continuous mode. Their applications in SMS preparation are summarized in this review. Many pharmaceutical co-crystals and solid dispersions have been successfully produced via the SAS process, where the solid-state properties of APIs can be well designed by controlling the operating parameters. The underlying mechanisms on the manipulation of solid-state properties are discussed, with the help of on-line monitoring and computational techniques. With continuous researching, SAS process will give a large contribution to the scalable and continuous manufacturing of desired SMS in the near future.

scholarly journals Fleet Resilience: Evaluating Maintenance Strategies in Critical Equipment

2020 ◽  
Vol 11 (1) ◽  
pp. 38
Author(s):  
Orlando Durán ◽  
Javier Aguilar ◽  
Andrea Capaldo ◽  
Adolfo Arata
Keyword(s):  
Application Study ◽  
System Availability ◽  
Maintenance Strategies ◽  
Resilience Index ◽  
Reliability Block Diagrams ◽  
Maintenance Policies ◽  
Definition Of ◽  
The Impact ◽  
Important System ◽  
Intrinsic Characteristic

Resilience is an intrinsic characteristic of systems. Through it, the capacity of a system to react to the existence of disruptive events is expressed. A series of metrics to represent systems’ resilience have been proposed, however, only one indicator relates the availability of the system to this characteristic. With such a metric, it is possible to relate the topological aspects of a system and the resources available in order to be able to promptly respond to the loss of performance as a result of unexpected events. This work proposes the adaptation and application of such a resilience index to assess the influence of different maintenance strategies and topologies in fleets’ resilience. In addition, an application study considering an actual mining fleet is provided. A set of critical assets was identified and represented using reliability block diagrams. Monte Carlo simulation experiments were conducted and the system availability data were extracted. Resilience indexes were obtained in order to carry out the definition of the best maintenance policies in critical equipment and the assessment of the impact of modifying system redundancies. The main results of this work lead to the overall conclusion that redundancy is an important system attribute in order to improve resiliency along time.

scholarly journals Integrating Modelling of Maintenance Policies within a Stochastic Hybrid Automaton Framework of Dynamic Reliability

2021 ◽  
Vol 11 (5) ◽  
pp. 2300
Author(s):  
Simone Arena ◽  
Irene Roda ◽  
Ferdinando Chiacchio
Keyword(s):  
Model Systems ◽  
Mitigation Measures ◽  
Repairable Systems ◽  
Maintenance Policy ◽  
Hybrid Automaton ◽  
Dynamic Reliability ◽  
Software Model ◽  
Maintenance Policies ◽  
Mathematical Techniques ◽  
Continuous And Discrete Variables

The dependability assessment is a crucial activity for determining the availability, safety and maintainability of a system and establishing the best mitigation measures to prevent serious flaws and process interruptions. One of the most promising methodologies for the analysis of complex systems is Dynamic Reliability (also known as DPRA) with models that define explicitly the interactions between components and variables. Among the mathematical techniques of DPRA, Stochastic Hybrid Automaton (SHA) has been used to model systems characterized by continuous and discrete variables. Recently, a DPRA-oriented SHA modelling formalism, known as Stochastic Hybrid Fault Tree Automaton (SHyFTA), has been formalized together with a software library (SHyFTOO) that simplifies the resolution of complex models. At the state of the art, SHyFTOO allows analyzing the dependability of multistate repairable systems characterized by a reactive maintenance policy. Exploiting the flexibility of SHyFTA, this paper aims to extend the tools’ functionalities to other well-known maintenance policies. To achieve this goal, the main features of the preventive, risk-based and condition-based maintenance policies will be analyzed and used to design a software model to integrate into the SHyFTOO. Finally, a case study to test and compare the results of the different maintenance policies will be illustrated.

Photon upconversion in multicomponent systems: Role of back energy transfer

2020 ◽  
Vol 153 (11) ◽  
pp. 114302
Author(s):  
Diletta Meroni ◽  
Angelo Monguzzi ◽  
Francesco Meinardi
Keyword(s):  
Energy Transfer ◽  
Multicomponent Systems ◽  
Back Energy Transfer
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