Search

Carbon/Carbon composites are advanced materials composed of carbon fibers and other carbon materials (graphite, graphene, carbon nanotubes, pyrolytic carbon, etc.). Due to the diverse structures and excellent properties of carbon fibers and other carbon-based materials, they have attracted widespread attention from scholars at home and abroad. Copper-carbon/carbon composites have gained widespread application in aerospace, electronic packaging, thermal management materials, high-speed rail transportation, and biomedical fields. Current laboratory studies indicate that these composites exhibit a friction coefficient of approximately 0.3, with flexural and tensile strengths reaching 150 MPa and 500 MPa respectively, and an overall thermal conductivity of about 600 W/m•K. Future research is expected to further optimize and enhance their fabrication methods, as well as their physical, mechanical, and biological properties. This review article provides a comprehensive overview of copper-carbon/carbon composites formed by combining copper with carbon fibers and other carbonaceous materials. It introduces several novel fabrication techniques, offering valuable references for research on copper-carbon/carbon composites. Additionally, the article discusses the future development trends of these advanced composite materials. [ABSTRACT FROM AUTHOR]

Silicon (Si) and boron (B) are a class of elements called metalloids, which have properties like metals and non-metals. Si is classified as a quasi-essential element, while B is a micronutrient element for plants. Nowadays, numerous discoveries have shown the analogy of silicon and boron in plant nutrition. In this minireview, the molecular mechanisms for the transport of these two metalloids are compared. We also discussed the chemical forms of Si and B and their functional similarity in response to environmental stresses in plants. In conclusion, it can be proposed that cell wall-bound silicon rather than silica might partially replace boron for plant growth, development, and stress responses, and the underlying mechanism is the Si contribution to B in its structural function. [ABSTRACT FROM AUTHOR]

Ultrafast diffusion disperses faster than super-diffusion, and this has been proven by several theoretical and experimental investigations. The mean square displacement of ultrafast diffusion grows exponentially, which provides a significant challenge for modeling. Due to the inhomogeneity, nonlinear interactions, and high porosity of cement materials, the motion of particles on their surfaces satisfies the conditions for ultrafast diffusion. The investigation of the diffusion behavior in cementitious materials is crucial for predicting the mechanical properties of cement. In this study, we first attempted to investigate the dynamic of ultrafast diffusion in cementitious materials underlying the Riemann–Liouville nonlocal structural derivative. We constructed a Riemann–Liouville nonlocal structural derivative ultrafast diffusion model with an exponential function and then extended the modeling strategy using the Mittag–Leffler function. The mean square displacement is analogous to the integral of the corresponding structural derivative, providing a reference standard for the selection of structural functions in practical applications. Based on experimental data on cement mortar, the accuracy of the Riemann–Liouville nonlocal structural derivative ultrafast diffusion model was verified. Compared to the power law diffusion and the exponential law diffusion, the mean square displacement with respect to the Mittag–Leffler law is closely tied to the actual data. The modeling approach based on the Riemann–Liouville nonlocal structural derivative provides an efficient tool for depicting ultrafast diffusion in porous media. [ABSTRACT FROM AUTHOR]

Microalgae are considered to be natural producers of bioactive pigments, with the production of pigments from microalgae being a sustainable and economical strategy that promises to alleviate growing demand. Chlorophyll, as the main pigment of photosynthesis, has been widely studied, but its medicinal applications as an antioxidant, antibacterial, and antitumor reagent are still poorly understood. Chlorophyll is the most important pigment in plants and algae, which not only provides food for organisms throughout the biosphere, but also plays an important role in a variety of human and man-made applications. The biological activity of chlorophyll is closely related to its chemical structure; its specific structure offers the possibility for its medicinal applications. This paper reviews the structural and functional roles of microalgal chlorophylls, commonly used extraction methods, and recent advances in medicine, to provide a theoretical basis for the standardization and commercial production and application of chlorophylls. [ABSTRACT FROM AUTHOR]

Microalgae are considered to be natural producers of bioactive pigments, with the production of pigments from microalgae being a sustainable and economical strategy that promises to alleviate growing demand. Chlorophyll, as the main pigment of photosynthesis, has been widely studied, but its medicinal applications as an antioxidant, antibacterial, and antitumor reagent are still poorly understood. Chlorophyll is the most important pigment in plants and algae, which not only provides food for organisms throughout the biosphere, but also plays an important role in a variety of human and man-made applications. The biological activity of chlorophyll is closely related to its chemical structure; its specific structure offers the possibility for its medicinal applications. This paper reviews the structural and functional roles of microalgal chlorophylls, commonly used extraction methods, and recent advances in medicine, to provide a theoretical basis for the standardization and commercial production and application of chlorophylls.

In this article, an innovative cooling system for photovoltaic panels is presented. This system uses the Seebeck effect to generate electricity. The proposed device differs from existing photothermoelectric systems by means of a compact, efficient and space-saving apparatus.In fact, in the proposed device the thermoelectric generator is integrated in the heat exchange system since the thermoelectric effect takes place inside the heat exchanger and only a small part of the removed heat is used to create the required temperature difference. A preliminary numerical analysis of the thermoelectric behaviour of the proposed device under different geometrical and fluid-dynamic conditions is also presented. For a standard photovoltaic panel of 100 ​× ​125 cm the proposed cooling system allows an increase of almost 15% of the electrical power converted by the cells. Moreover, the exploited Seebeck effect provides an electrical power (ranging from 61.2 to 71.2 ​W in the studied cases) that is respectively 10.9 and 1.33 times the power required for forced ventilation. The maximum system electrical power reachable, using commercial inorganic thermoelectric materials, considering all electrical power gains and losses is next to 300–310 ​W/m2.

Isotropic and anisotropic shape‐memory polymer foams are prepared by supercritical carbon dioxide foaming from a multiblock copolymer (PDLCL) consisting of poly(ω‐pentadecalactone) and poly(ε‐caprolactone) segments. Analysis by micro‐computed tomography reveals for the anisotropic PDLCL foam cells a high shape anisotropy ratio of R = 1.72 ± 0.62 with a corresponding Young's compression moduli ratio between longitudinal and transversal direction of 4.3. The experimental compression data in the linear elastic range can be well described by the anisotropic open foam model of Gibson and Ashby. A micro‐morphological analysis for single pores using scanning electron microscopy images permits the correlation between the macroscopic stress‐compression behavior and microscale structural changes. [ABSTRACT FROM AUTHOR]

The development of Internet technologies and their application to commerce environments has favored new business strategies for industries. These allow including in the design phase the experience of use that the clients have of the product. However, this new element has not been considered in formal terms. A fundamental problem in product design is that it has not been modeled in mathematical terms, which means that their characteristics do not appear in rigorous and short properties, but in long developments that from an economic point of view maintain their meaning but that from a mathematical point of view are not sufficiently manageable. Therefore, since these properties have not been axiomatically formalized, we cannot work with them mathematically. For this reason, we propose analyzing the design of products through a network and discrete chaos theory perspective, which will allow us to use important mathematical tools such as graph theory and concepts, such as coverage, invariability, orbits, attractors, and the structural function. This paper also draws attention to the importance of circular flow in the general systems theory and its application to the design phase of products. Finally, the Intel case study is analyzed, locating the current attractor and its relationship with the success of the company's products.

In the studies related to thermodynamic and structural functions of liquid alloys at high temperatures using linear temperature-dependent interaction parameters, in some cases, artificial miscibility gaps or artefacts are noticed. These artificial miscibility gaps in these functions at higher temperatures are usually asymmetric with respect to the concentration. The presence of the artificial miscibility gaps in the properties of the alloys at higher temperatures makes them less reliable and such data cannot be accepted at all. In the present work, we have computed thermodynamic and structural properties of liquid Al–Li alloy at temperatures 800, 1300 and 2000 K in the framework of Redlich–Kister (R-K) polynomials assuming interaction parameters to be linear temperature dependent and some artefacts were observed in these functions at around 2000 K. We have then obtained the optimised set of exponential temperature-dependent interaction parameters and computed the properties of the alloy again from the same polynomials where no miscibility gap was noticed at higher temperatures. [ABSTRACT FROM AUTHOR]

This paper reports the construction of a method for calculating the structural function within a moving window of the fixed size, based on measuring the vector of current concentrations of arbitrary air pollutants. The use of a moving window makes it possible to reveal the current moments of the emergence of inhomogeneities in the polluted atmosphere. In this case, the time shift of the structural function reveals the corresponding time scale of this heterogeneity. It has been shown that, in contrast to the known method, the proposed method makes it possible to reveal the dynamics of the levels and scales of local inhomogeneities of the polluted air using only the current measurements of concentration for an arbitrary number of pollutants. It is noted that the method does not use information about the current meteorological conditions of the atmosphere and the features of urban infrastructure near a pollution control point. Therefore, the method is universal; it could be applied to arbitrary control points of atmospheric pollution across various territories of states. The efficiency of the proposed method was tested using the example of actual measurements of the concentrations of urban air pollutants involving formaldehyde, ammonia, and nitrogen dioxide. The reported results generally indicate the applicability of the proposed method. It has been experimentally established that the method makes it possible to identify, in real time, the areas of local inhomogeneities characteristic of hazardous air pollution associated with the absence of dispersion and accumulation of pollutants in the air. In addition, the method makes it possible to detect in real time both the levels and the scale of inhomogeneities in the polluted atmosphere. It has been experimentally established that before the occurrence of the tested reliable emergency in a polluted atmosphere, the level of local heterogeneity was 0.015 units at its time scale corresponding to 8 counts. Next, by the time of the emergency, the level of heterogeneity decreased to 0.0025 units at the time scale corresponding to 2 counts. It has been experimentally established that for this case the forecast time of the occurrence of an emergency was 4 counts or 24 hours. [ABSTRACT FROM AUTHOR]

Copyright of Secretary (16742354) is the property of Secretary Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In Spain, gypsum and its many typologies play an important role as a construction material in Spanish architectural heritage. Its historical use is mainly a direct consequence of the abundance of gypsum deposits and a constructive tradition which began in ancient times. In addition to being a sign of constructive identity, gypsum is a clear example of the strong link between traditional architecture and the natural resources of the territory. The aim of this article is after to identify gypsum deposits and gypsum architectural heritage found in different parts of Spain and to explain the different gypsum typologies—other than powdered gypsum—used. Finally, the most unique construction techniques are described, differentiating between structural elements, partitions, and enclosures, as well as architectural elements and surface finishes. [ABSTRACT FROM AUTHOR]

Several selection pressures may explain the evolution of avian eggshell coloration patterns. In cavity-nesting species, there are two main non-exclusive hypotheses. The sexually selected eggshell colour hypothesis proposes that eggshell coloration is a sexually selected signal of female and offspring quality used by males that influences paternal care or future re-mating decisions. The structural function hypothesis proposes that pigments help strengthen the eggshell and are present at higher levels and at the blunt end of the egg when females face calcium shortages. We tested whether eggshell coloration (brown spots on a white ground colour) in blue tits (Cyanistes caeruleus) could reliably indicate female condition at laying by forcing females to produce two consecutive clutches, thus increasing their reproductive costs. Three measures of eggshell coloration – the area covered by spots as well as white ground UV-chroma and brightness – changed between clutches; the fourth measure, spot distribution, did not. The changes were more dramatic in young and lower-quality females. All the measures varied with female quality (i.e. body condition and/or laying date). Overall, higher-quality females produced more colourful (larger, more concentrated spotted surface area; higher UV-chroma) and less bright (i.e. putatively more pigmented) eggshells, a result that is generally in line with past research. We found a clear empirical link between eggshell coloration and female condition in blue tits, an important step in determining whether eggshell coloration is a sexual signal, but which does not exclude a potential concomitant structural function. [ABSTRACT FROM AUTHOR]

Highlights • Non-local structural derivative is used to illustrate concrete ultra-slow rheology. • Creep and relaxation responses are formulated by the proposed models. • The Lomnitz creep law is a special case of the ultra-slow Maxwell model. • The ultra-slow Maxwell model is validated by several concrete creep data. Abstract Ultra-slow rheological phenomena have widely been observed in engineering materials. The logarithmic law is normally used to describe the slow rheology, but it does not work well for the long-term ultra-slow rheology. In this paper, we devise a new Maxwell-type viscoelastic model to capture the ultra-slow rheology by using the non-local structural derivative, where the inverse Mittag-Leffler (ML) structural function is adopted. The viscoelastic responses of the ultra-slow Maxwell model are analytically derived, including creep and relaxation. The logarithmic creep law can be regarded as a special case of the ultra-slow Maxwell model. In addition, the proposed model is tested by several experimental data of concrete. Compared with the existed models, the present ultra-slow Maxwell model shows the reasonable accuracy. The derived results indicate that the non-local structural derivative involving the inverse ML function is feasible to capture the ultra-slow rheology of concrete. [ABSTRACT FROM AUTHOR]

A large quantity of resources consumed by the construction industry and the resultant pollution has inspired the need to study eco-friendly materials, such as kenaf fibers, that can be used for construction applications. Kenaf fibers were used to reinforce cement by fabricating fiber reinforced cement composites that exhibited outstanding mechanical and thermo-physical properties. A considerable interest has arisen in investigating the use of natural fiber to replace synthetic fiber for different composite products to alleviate the environmental impact from the traditional construction materials. In order to evaluate the environmental performances of glass fiber reinforced cement wall panels and kenaf fiber reinforced cement wall panels, this study conducted a comparative life cycle assessment (LCA) on the fiber reinforced cement wall panels between kenaf fiber and traditional glass fiber. The structural function and thermal insulation function of the wall panels were considered as two separate functional units. The LCA results showed that the environmental impact could be significantly reduced using kenaf fiber to replace glass fiber as reinforcement in the cement wall panels in regards to both structural and insulation functions. The major contribution to the environmental impact for the fiber reinforced wall panels was from cement and the production of the cement raw materials. Kenaf fiber significantly reduced environmental impact, which can be a viable eco-friendly material to replace glass fiber for the construction industry. [ABSTRACT FROM AUTHOR]

The effects of sharp variations in geomagnetic and solar activity at high latitudes on human brain bioelectrical activity were studied using a multichannel EEG structural function. Studies were performed on 10 healthy men aged 19-37 years. EEG recordings were made daily for 25 days. Solar flares of classes C and M occurred during the study period, as did geomagnetic storms of levels G2-G3. A first-order temporal structural function (SF) in eight-dimensional space was calculated from the EEG. The time scales of internal correlations in the multichannel EEG were assessed using the radius of the correlation of the SF, while the spatial correlational structure of the EEG was assessed in terms of the SF asymptote. Variations in geomagnetic activity were found to be reflected more in changes in the correlation radius than the level of the SF asymptote. Perturbing and modulating effects of geomagnetic and solar activity on SF parameters and the SF spectrum were identified. Thus, the SF of the multichannel EEG can be used to evaluate the integral reaction of the brain as a unified system to the actions of heliogeophysical factors and can be used in studies of the effects of the environment on humans. [ABSTRACT FROM AUTHOR]

In ultrasonic equipment (anemometers and thermometers), for the measurement of parameters of atmospheric turbulence, a standard algorithm that calculates parameters from temporary structural functions constructed on the registered data is usually used. The algorithm is based on the Kolmogorov−Obukhov law. The experience of using ultrasonic meters shows that such an approach can lead to significant errors. Therefore, an improved algorithm for calculating the parameters is developed, which allows more accurate estimation of the structural characteristics of turbulent fluctuations, with an error that is not more than 10%. The algorithm was used in the development of a new ultrasonic hardware-software complex, autonomous meteorological complex AMK-03-4, which differs from similar measuring instruments of turbulent atmosphere parameters by the presence of four identical ultrasonic anemometers. The design of the complex allows not only registration of the characteristics of turbulence, but also measurement of the statistical characteristics of the spatial derivatives of turbulent temperature fluctuations and orthogonal components of wind speed along each of the axes of the Cartesian coordinate system. This makes it possible to investigate the space−time structure of turbulent meteorological fields of the surface layer of the atmosphere for subsequent applications in the Monin−Obukhov similarity theory and to study turbulent coherent structures. The new measurement data of the spatial derivatives of temperature at stable stratification (at positive Monin−Obukhov parameters) were obtained, at which the behavior of the derivatives was been investigated earlier. In the most part of the interval of positive Monin−Obukhov parameters, the vertical derivative of the temperature is close to a constant value. This fact can be considered as a new significant result in similarity theory.

The main objectives of this paper are to formulate an introduction to the mathematical theory of indirect effects with respect to some biotic relations, including symbiosis, commensalism, mutualism and predation, along with the time functions for these relationships. We employ the theory of system linkage in Patten’s Theory of Environment to develop an analysis of the theoretical properties of direct and indirect influences, using the variables and structure of each system involved in the linkage. In this paper, in order to formulate the mathematical theory, we develop, as a contribution to Patten’s Theory of Environment, so-called H-semiotic systems.

The paper describes buildinga gas furnace model basedon the method of structural and parametric identification by discrete measurements of accidental input and output processes. The method is based on the theory of continued fractions. The method includes checkingthe stationarity and homogeneity of the furnaceprocesses, receiving the discrete model of the furnace, which can be further used for predicting, monitoring, control and diagnostics of the gas furnace processes.

This study investigates the ultraslow diffusion by a spatial structural derivative, in which the exponential function ex is selected as the structural function to construct the local structural derivative diffusion equation model. The analytical solution of the diffusion equation is a form of Biexponential distribution. Its corresponding mean squared displacement is numerically calculated, and increases more slowly than the logarithmic function of time. The local structural derivative diffusion equation with the structural function ex in space is an alternative physical and mathematical modeling model to characterize a kind of ultraslow diffusion. [ABSTRACT FROM AUTHOR]

Noodle dough is a complex system formed by the effects of external forces on water, starch, gluten, arabinoxylan. The migration of water among wheat flour ingredients affects dough structure and the processing and quality of wheat noodles. Spontaneous water molecule migration depends on competitive water absorption among different components, whereas the regularity and mechanism remain unclear. This study investigated the interaction of water molecules with flour ingredients. LF-NMR indicated that starch, with the largest content in flour, smallest contact angle, and uniform particles, shifted the hydrogen proton peaks towards short T 2 direction and narrowed the width of peaks. In addition, SEM showed the compactness and filling capacity of starch, accounted for its ability to uniformize water distribution (MRI). Gluten and arabinoxylan had stronger water trapping capacity, dispersed particles, and a loose and viscoelastic network structure that altered the water properties within dough. Spontaneous water molecule migration established a dynamic equilibrium between starch attraction and gluten-arabinoxylan constraint, providing dough for subsequent stages of noodle-making process. [Display omitted] • In wheat noodles, starch granules fully filled the viscoelastic network complexes constructed by gluten and arabinoxylans. • Water molecules spontaneously established a dynamic equilibrium between starch granules and gluten-arabinoxylan complexes. • Starch granules greatly attracted water molecules and made water molecules more structured and homogeneous. • Gluten-arabinoxylan network disorganized the structured and homogeneous water molecules made by starch granules. • Conventional water classification was corresponded with the water categories illustrated in transverse relaxation time (T 2) spectrum of LF-NMR. [ABSTRACT FROM AUTHOR]

Copyright of China Textile Leader is the property of China Textile Information Center and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Our work concerns interaction spherical study of three toxic products, bromobenzene, tetrachloroethylene, and 4-hydroxy-chromene-2-one; using the Leap Frog algorithm, we calculated new values of cut-off of the box through Lennard-Jones potential parameters. This model was adapted to allow the determination of the characteristics for the SP, SP and SP state points and was applied to study the properties for the three products by molecular dynamics. This method provides an advantage to confirm the structure-activity relationship for these compounds. We calculated the thermodynamic and structural properties for both canonical NVT and isothermal-isobaric NPT ensembles of these products. Numerical system results have been compared with both experimental data and recent investigation theoretical. Our simulation model isobaric-isothermal system gives accurate results, and comparing with the canonical system, this model agrees very well with the experimental data. We aim to demonstrate that the classical approach with a low statistical uncertainty for liquid toxic leads to data in very good agreement with experiment or other types of calculations. We obtained a good prediction of the thermodynamic properties. We hope that this model with a lower threshold to 2.5σ could be an effective starting material for studying the properties of complex systems. [ABSTRACT FROM AUTHOR]

The possibility of passive synthesis of the antenna aperture for satellite systems of monitoring ground-based radio radiation sources is discussed. Experimental data on the inverse passive synthesis on the Space-Earth paths are presented for reception of GPS navigation satellite radiation. The data confirm the possibility of developing the passive synthesized aperture radar and interference phase signal processing. [ABSTRACT FROM AUTHOR]

Abstract: This work concerns the site–site interaction study of 256 particles using the Buckingham potential model. We have calculated the new parameters of the Buckingham potential using an iterative algorithm with a mean square method. This adapted model allows determining the characteristics for each state point. We have applied this model to study the liquefied natural gas LNG properties for methane-nitrogen and methane–nitrogen–ethane mixtures by molecular dynamics. We have calculated the thermodynamic, dynamic and structural properties for both the microcanonical NVT and the isothermal-isobaric NPT ensembles of binary and ternary systems from the SP1 to SP9 points. Then, we have compared the results between binary and ternary systems. We have obtained a good prediction on transport properties. From the calculated values of self-diffusion coefficient and viscosity, we have confirmed the liquid state of the liquefied natural gas LNG system. [Copyright &y& Elsevier]

The problem of information extraction from discrete stochastic time series, produced with some finite sampling frequency, using flicker-noise spectroscopy, a general framework for information extraction based on the analysis of the correlation links between signal irregularities and formulated for continuous signals, is discussed. It is shown that the mathematical notions of Dirac δ- and Heaviside θ-functions used in the analysis of continuous signals may be interpreted as high-frequency and low-frequency stochastic components, respectively, in the case of discrete series. The analysis of electroencephalogram measurements for a teenager with schizophrenic symptoms at two different sampling frequencies demonstrates that the "power spectrum" and difference moment contain different information in the case of discrete signals, which was formally proven for continuous signals. The sampling interval itself is suggested as an additional parameter that should be included in general parameterization procedures for real signals. [ABSTRACT FROM AUTHOR]

Currently, it is challenging to select endpoints for measuring disease progression in glaucoma clinical trials. The endpoints that are used are not biological, but statistical, events because there is no reference standard for progression. Progression rates depend on the criteria used to define change, and in the absence of a reference standard for progression, reasonable criteria can be determined by paying attention to specificity (ie false-positive rate). Past randomized-clinical trials (CITGS, OHTS, and CNGT) have not made a accurate estimate of specificity at the time of trial design. It is not meaningful to compare the sensitivities (or more accurately the ‘hit rate’) of different progression criteria unless their respective specificities are equivalent. The ideal approach to compare progression rates, therefore, would be to equalize the specificities with each approach. However, owing to the lack of an external standard, this is difficult to achieve with reasonable confidence. With the advancement of research in visual field and imaging, clinical endpoints will have to be reviewed to incorporate new criteria for progression detection and measurement.Eye (2007) 21, S34–S37; doi:10.1038/sj.eye.6702886 [ABSTRACT FROM AUTHOR]

Based on some of the results and definitions provided in the article System linkage: Structural functions and hierarchies (Lloret et al. “System linkage: structural functions and hierarchies”, Cybern. Syst. Int. J., 29, pp. 35–46, 1998) and adding new definitions that are in keeping with the spirit of the same article, new results have been obtained that explore the utility of the structural input–output function (also transferable to the other structural functions) and that expand on studies conducted to date on variables (cells).Our approach is based principally on the application of graph theory to the study of relationships between variables (cells) using specific set theory concepts, introducing new definitions and adapting continuous function properties to our discrete environment. More specifically, we present two new concepts—coverage between sets and the invariant set—analysing their inter-relatedness from the perspective of structural functions, i.e. from the point of view of influences in the system. To date these concepts have been handled from a continuous point of view, and so the discrete approach described here will lay the foundations for new developments in this direction.Although the development of the concepts may, a priori, appear to very theoretical, they are, in fact, much more practical than would appear to be the case. A result such as the fact that A covers B, for example, can be interpreted in terms of the latter set being formed of direct influences from elements in the former set in relation to one or more than one relationships. Analogously, the invariant set concept may be interpreted as the set maintaining its structure and status, remaining constant with respect to any possible relationships. [ABSTRACT FROM AUTHOR]

A coherent system with independent components and known minimal paths (cuts) is considered. In order to compute its reliability, a tree structure T is constructed whose nodes contain the modified minimal paths (cuts) and numerical values. The value of a non-leaf node is a function of its child nodes'' values. The values of leaf nodes are calculated from a simple formula. The value of the root node is the system''s failure probability (reliability). Subsequently, an algorithm computing the system''s failure probability (reliability) is constructed. The algorithm scans all nodes of T using a stack structure for this purpose. The nodes of T are alternately put on and removed from the stack, their data being modified in the process. Once the algorithm has terminated, the stack contains only the final modification of the root node of T, and its value is equal to the system''s failure probability (reliability). [Copyright &y& Elsevier]