Efficiency Of Complex Systems Research Articles

Adsorption behavior of lead, cadmium, and arsenic on manganese-modified biochar: competition and promotion.

Biochar adsorption of heavy metals has been a research hotspot, yet there has been limited reports on the effect of heavy metal interactions on adsorption efficiency in complex systems. In this study, the adsorbent was prepared by pyrolysis of rice straw loaded with manganese (BC-Mn). The interactions of Pb, Cd and As adsorption on BC-Mn were systematically studied. The results of the adsorption isotherms for the binary metal system revealed a competitive adsorption between Pb and Cd, resulting in decreased Pb (from 214.38mg/g to 148.20mg/g) and Cd (from 165.73mg/g to 92.11mg/g). A notable promotion occurred between As and Cd, showing an increase from 234.93mg/g to 305.00mg/g for As and 165.73mg/g to 313.94mg/g for Cd. In the ternary metal system, Pb inhibition did not counteract the promotion of Cd and As. Furthermore, the Langmuir isotherm effectively described BC-Mn's adsorption process in monometallic, binary, and ternary metal systems (R2 > 0.9294). Zeta and FTIR analyses revealed simultaneous competition between Pb and Cd for adsorption on BC-Mn's -OH sites. XPS analysis revealed that As adsorption by BC-Mn facilitated the conversion of MnO2 and MnO to MnOOH, resulting in increased hydroxyl radical production on BC-Mn's surface. Simultaneously, Cd combined with the adsorbed As to form ternary Cd-As-Mn complexes, which expedited the removal of Cd. These results help to provide theoretical support as well as technical support for the treatment of Pb-Cd-As contaminated wastewater.

Creating a concept and axiomatization of the applied theory of efficiency of complex technical systems with distributed parameters of input and output products

The object of this study is the processes of optimal control over complex technical systems with input and output products distributed in time. The automatic formation of optimal control trajectories of technical systems that ensure maximum efficiency of production processes is limited by the insufficient development of the applied theory of the efficiency of complex systems. This work considers the development of the conceptual base and axiomatization of the applied theory of the efficiency of technical systems. A system of definitions and a system of axioms describing the indicators of the functioning of the cybernetic model of a technical system have been developed. The resulting system of axioms formalizes the technique and methods for determining various indicators, as well as obtaining the current value of the performance indicator of the technical system. The obtained expressions make it possible to form a subsystem for assessing the effectiveness of a technical system, invariant with respect to its internal structure and the characteristics of the transformation processes implemented by it. The universality of the proposed indicators and the structural unity of the performance evaluation subsystem make it possible to express an opinion on the cybernetic level of these decisions. An example of the practical application of the proposed system of axioms of the applied theory of efficiency is given. The proposed method for determining the efficiency indicator can be applied to arbitrary technical systems with a distributed nature of the change in input and output products. The cybernetic level of abstractions used to determine the effectiveness of complex systems makes it possible to proceed to solving the problem of formalization and full automation of the processes of optimal control over complex technical systems with distributed input and output products

Nanoparticle affinity for natural soils: a functional assay for determining particle attachment efficiency in complex systems

Few standardized methods and reference systems have been established for evaluating the behavior of engineered nanomaterials in complex media like natural soils.

Method of dependability assessment of spacecraft in design and engineering studies

The paper examines the matters of operational dependability of space systems (SS), efficiency of complex systems, use of redundancy in spacecraft (SC) design. It presents methods of predicting the dependability of designed devices, design of devices with desired dependability and comparison of dependability of various SS. For that purpose, the authors set forth the fundamentals of the dependability theory for SS design, methods of collection and processing of data of equipment dependability based on the results of operation and special dependability tests. Methods, mathematical models are developed, the equipment architecture at the stage of design and manufacture is analyzed. The paper also cites the design ratios for various tested types of redundancy, lifetime extension of SC units based on the residual operating life estimation method. The existing methods of dependability analysis are classified and examined. The authors outline the problems of ambiguity of information of the input data in case of classical computing. The effect of nominal deviations of the external effects, irregularity of the failure rate, non-linear nature of the effect of external factors on the dependability are examined. The paper also takes a look at the way the external factors affect the dependability and the degree to which such factors are taken into consideration in the existing methods. It is noted that the qualitative, technical and organizational (design and software) requirements for dependability in the technical specifications for each stage of elements and SS development, shall be observed and confirmed at the respective stage of activities. The paper presents the methods of estimation of technical item operating life with the focus on those based on the physical premises of operating life depletion. Attention is drawn to the importance of the economic aspect in the research dedicated to SS lifetime extension.

Analysis of the efficiency of complex systems

Analysis of the efficiency of complex systems

КОМПЛЕКСНІ ТЕПЛОУТИЛІЗАЦІЙНІ СИСТЕМИ ДЛЯ КОТЛІВ МАЛОЇ ТА СЕРЕДНЬОЇ ПОТУЖНОСТІ З ПІДВИЩЕНИМ ВОЛОГОВМІСТОМ ВІДХІДНИХ ГАЗІВ

The results of studies of thermal and humidity regimes and thermal efficiency of complex systems for recovering waste heat from boiler plants with an increased moisture content of exhaust-gases are presented. Systems designed for heating boiler water, water of a chemical water treatment system and combustion air are considered. It is shown that, according to the heat engineering indications, systems with heating boiler water and combustion air have advantages over systems for heating input boiler water and water for chemical water treatment.

Measuring Nanoparticle Attachment Efficiency in Complex Systems.

As process-based environmental fate and transport models for engineered nanoparticles are developed, there is a need for relevant and reliable measures of nanoparticle behavior. The affinity of nanoparticles for various surfaces (α) is one such measure. Measurements of the affinity of nanoparticles obtained by flowing particles through a porous medium are constrained by the types of materials or exposure scenarios that can be configured into such column studies. Utilizing glass beads and kaolinite as model collector surfaces, we evaluate a previously developed mixing method for measuring nanoparticle attachment to environmental surfaces, and validate this method with an equivalent static column system over a range of organic matter concentrations and ionic strengths. We found that, while both impacted heteroaggregation rates in a predictable manner when varied individually, neither dominated when both parameters were varied. The theory behind observed nanoparticle heteroaggregation rates (αβB) to background particles in mixed systems is also experimentally validated, demonstrating both collision frequency (β) and background particle concentration (B) to be independent for use in fate modeling. We further examined the effects of collector particle composition (kaolinite vs glass beads) and nanoparticle surface chemistry (PVP, citrate, or humic acid) on α, and found a strong dependence on both.

Distributions of phenolic acid antioxidants between the interfacial and aqueous regions of corn oil emulsions—a commentary

Being capable of optimizing the usage of antioxidants is a challenge for any industry concerned with formulating food and non‐food products because it will affect its competitiveness and the product's attractiveness in response to consumer demand. This is also a challenge for scientists who remain puzzled by the unpredictable oxidative behavior of real, complex food, and non‐food matrices. Laurence Romsted and Carlos Bravo‐Diaz have developed some years ago a pseudophase kinetic model to determine the partitioning of chain‐breaking antioxidants in micellar systems and emulsions stabilized by surfactants. In this article, with Sonia Lasada‐Barreiro they used the pseudophase model to determine the partitioning of two phenolic antioxidants (gallic acid and caffeic acid) in a model oil‐in‐water emulsion with increasing surfactant concentrations and at different pH values. This commentary underlines the importance of the pseudo‐phase model and the present work to achieve a better use of antioxidants. It is also suggested that the enigma of antioxidant efficiency in complex systems is far from completely solved.

Using simulation and logic-probabilistic models to evaluate the effectiveness of complex systems

Substantiates methodical approach to the evaluation of the performance of complex systems using the aggregation of logical and probabilistic models and simulation. The necessity of direct or indirect use in terms of efficiency of complex systems the probability of their success as intended.

Evaluation of system efficiency using the Monte Carlo DEA: The case of small health areas

This paper uses Monte Carlo Data Envelopment Analysis (Monte Carlo DEA) to evaluate the relative technical efficiency of small health care areas in probabilistic terms with respect to both mental health care as well as the efficiency of the whole system. Taking into account that the number of areas did not permit maximum discrimination to be achieved, all the scenarios of non-correlated inputs and outputs of a specific size were designed using Monte Carlo Pearson to maximize the discrimination of Monte Carlo DEA and the information included in the models. A knowledge base was included in the simulation engine in order to guide the dynamic interpretation of non-standard inputs and outputs. Results show the probability that all DMU and the whole system have of being efficient, as well as the specific inputs and outputs that make the areas or the system efficient or inefficient, along with a classification of the areas into four groups according to their efficiency (k-means cluster analysis). This final classification was compared with an expert-based classification to validate both the knowledge base and the Monte Carlo DEA model. Both classifications showed results that were very similar although not exactly the same, basically due to the difficulty experts experience in recognizing “intermediately-inefficient” DMU. We propose this methodology as an instrument that could help health care managers to assess relative technical efficiency in complex systems under uncertainty.

Analyzing reliability for systems with complex structure on multilevel models

We consider approaches to modeling reliability and technical efficiency of complex systems. We give a brief classification of models and approaches to system reliability analysis. We discuss decomposition and aggregation methods for static and dynamic models. As an example, we briefly characterize gas supply systems.