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In this paper, we present the upgraded version of RockGIS, a stochastic program for the numerical simulation of rockfalls and their fragmentation, based on a fractal model. The code has been improved to account for a range of fragmentation scenarios, depending on the impact conditions. In the simulation, the parameters of the fractal fragmentation model that define the sizes of the generated fragments were computed at each impact according to the kinematic conditions. The performance of the upgraded code was verified and validated by real-scale rockfall tests performed in a quarry. The tests consisted of the release of 21 limestone blocks. For each release, the size and spatial distribution of the fragments generated by the impacts were measured by hand and from orthophotos taken via drone flights. The trajectories of the blocks and the resulting fragments were simulated with the code and calibrated with both the volume distribution and the runout distances of the fragments. Finally, as all the relevant rockfall parameters involved were affected by strong uncertainty and spatial variability, a parametric analysis was carried out and is discussed., This work has been carried out with the support of the Spanish Ministry of Economy and Competitiveness thanks to a fellowship to the first author (BES-2014-069795) and in the framework of the research project RockModels (Ref. BIA2016-75668-P, AEI/FEDER, UE). The collaboration of Canteras Hermanos Foj (Barcelona metropolitan area, Spain) is gratefully acknowledged., Peer Reviewed, Postprint (published version)

Functional coatings produced using scalable and cost-effective processes such as electrodeposition and etching lead to the creation of random roughness at multiple length scales on the surface. The first part of thesis work aims at developing a fundamental mathematical understanding of multiscale coatings by presenting a fractal model to describe wettability on such surfaces. These surfaces are described with a fractal asperity model based on the Weierstrass-Mandelbrot function. Using this description, a model is presented to evaluate the apparent contact angle in different wetting regimes. Experimental validation of the model predictions is presented on various hydrophobic and superhydrophobic surfaces generated on several materials under different processing conditions. Superhydrophobic surfaces have myriad industrial applications, yet their practical utilization has been severely limited by their poor mechanical durability and longevity. Toward addressing this gap, the second and third parts of this thesis work present low cost, facile processes to fabricate superhydrophobic copper and zinc-based coatings via electrodeposition. Additionally, systematic studies are presented on coatings fabricated under different processing conditions to demonstrate excellent durability, mechanical and underwater stability, and corrosion resistance. The presented processes can be scaled to larger, durable coatings with controllable wettability for diverse applications. Apart from their use as superhydrophobic surfaces, the application of multiscale coatings in photo-thermal conversion systems as solar selective coatings is explored in the final part of this thesis. The effects of scale-independent fractal parameters of the coating surfaces and heat treatment are systematically explored with respect to their optical properties of absorptance, emittance, and figure of merit (FOM).

Enzymatic hydrolysis of corn stover was studied at agitation speeds from 50 to 500 rpm in a stirred tank bioreactor, at high solid concentrations (20% w/w dry solid/suspension), 50 °C and 15.5 mgprotein·gglucane −1. Two empirical kinetic models have been fitted to empirical data, namely a potential model and a fractal one. For the former case, the global order dramatically decreases from 13 to 2 as agitation speed increases, suggesting an increment in the access of enzymes to cellulose in terms of chemisorption followed by hydrolysis. For its part, the fractal kinetic model fits better to data, showing its kinetic constant a constant augmentation with increasing agitation speed up to a constant value at 250 rpm and above, when mass transfer limitations are overcome. In contrast, the fractal exponent decreases with rising agitation speed till circa 0.19, suggesting higher accessibility of enzymes to the substrate. © 2016 Elsevier Ltd

This paper presents a preliminary work to evaluate the thermal conductivity performance in pure and blended cement pastes with fly ash, slag and silica fume. The thermal conductivity of cement pastes cured in saturated and dry status with different hydration ages are also measured and predicted by quick thermal conductivity meter (QTM) and innovative non-contact impedance measurement (NCIM) based on a newly proposed fractal model. Besides, a corresponding simulation of fractal-like network is developed to evaluate the influences of pore structure parameters, intrinsic thermal conductivity coefficients of solid and water or gas phase on thermal conductivity performance of cement pastes. (C) 2014 Elsevier Ltd. All rights reserved.

The article examined the fractal model of organizational diagnosis of pathologies in project management development. The proposed fractal model based on the competency approach to project management and allows evaluating the pathology of the project-oriented organizations., В статье рассматривается фрактальная модель диагностики организационных патологий в управлении проектами развития. Предложенная фрактальная модель базируется на основе компетентностного подхода в управлении проектами и позволяет оценивать патологии деятельности проектно-ориентированных организаций., У статті розглядається фрактальна модель діагностики організаційних патологій в управлінні проектами розвитку. Запропонована фрактальна модель базується на основі компетентнісного підходу в управлінні проектами і дозволяє оцінювати патології діяльності проектно-орієнтованих організації.

This paper presents a preliminary work to evaluate the thermal conductivity performance in pure and blended cement pastes with fly ash, slag and silica fume. The thermal conductivity of cement pastes cured in saturated and dry status with different hydration ages are also measured and predicted by quick thermal conductivity meter (QTM) and innovative non-contact impedance measurement (NCIM) based on a newly proposed fractal model. Besides, a corresponding simulation of fractal-like network is developed to evaluate the influences of pore structure parameters, intrinsic thermal conductivity coefficients of solid and water or gas phase on thermal conductivity performance of cement pastes. (C) 2014 Elsevier Ltd. All rights reserved.

This paper presents a preliminary work to evaluate the thermal conductivity performance in pure and blended cement pastes with fly ash, slag and silica fume. The thermal conductivity of cement pastes cured in saturated and dry status with different hydration ages are also measured and predicted by quick thermal conductivity meter (QTM) and innovative non-contact impedance measurement (NCIM) based on a newly proposed fractal model. Besides, a corresponding simulation of fractal-like network is developed to evaluate the influences of pore structure parameters, intrinsic thermal conductivity coefficients of solid and water or gas phase on thermal conductivity performance of cement pastes. (C) 2014 Elsevier Ltd. All rights reserved.

This paper evaluates the permeability assessment of young cement pastes using innovative Non-Contact Impedance Measurement (NCIM). A fractal permeability model based on NCIM is proposed in this work. The permeability value of young cement pastes can be measured non-destructively and continuously with hydration by means of this model and NCIM. Furthermore, a fractal simulation is conducted to study the influence of porosity, minimal and maximal pore sizes on permeability. From the comparison of experimental and simulated results, the fractal model and simulation based on NCIM may provide an alternative way to evaluate the permeability of young cement-based materials in situ. (C) 2014 Elsevier Ltd. All rights reserved.

This paper evaluates the permeability assessment of young cement pastes using innovative Non-Contact Impedance Measurement (NCIM). A fractal permeability model based on NCIM is proposed in this work. The permeability value of young cement pastes can be measured non-destructively and continuously with hydration by means of this model and NCIM. Furthermore, a fractal simulation is conducted to study the influence of porosity, minimal and maximal pore sizes on permeability. From the comparison of experimental and simulated results, the fractal model and simulation based on NCIM may provide an alternative way to evaluate the permeability of young cement-based materials in situ. (C) 2014 Elsevier Ltd. All rights reserved.

Understanding the changes in multiphase flow parameters caused by mineral dissolution-precipitation is required for multiple applications ranging from geological storage of CO2, enhanced geothermal energy production or ground water pollution. We present a physically-based theoretical model for describing the temporal evolution of porosity, saturated and relative permeabilities, retention curve and diffusion coefficient during rock dissolution by reactive fluids. The derivation of the model is based on the assumption that the pore structure of the rock can be represented by an ensemble of capillary tubes with fractal tortuosity and cumulative pore size distribution. Therefore, the model depends only on the minimum and maximum pore radii, the size of the representative elementary volume and the fractal dimensions of pore size and tortuosity, but do not need any other fitting parameters. Using this fractal description and known physical properties, we obtain analytical expressions for the hydrodynamic properties required by continuum (i.e., Darcy scale) multiphase flow models. Further, assuming periodic fluctuations in the radius of the pores, it is also possible to represent constrictivity and hysteresis. Finally, assuming a constant rate dissolution reaction it is possible to derive closed-form analytical expressions for the time evolution of porosity, retention curve, saturated and relative permeabilities and diffusion coefficient. (C) 2014 Elsevier Ltd. All rights reserved., Peer Reviewed, Postprint (published version)

This paper evaluates the permeability assessment of young cement pastes using innovative Non-Contact Impedance Measurement (NCIM). A fractal permeability model based on NCIM is proposed in this work. The permeability value of young cement pastes can be measured non-destructively and continuously with hydration by means of this model and NCIM. Furthermore, a fractal simulation is conducted to study the influence of porosity, minimal and maximal pore sizes on permeability. From the comparison of experimental and simulated results, the fractal model and simulation based on NCIM may provide an alternative way to evaluate the permeability of young cement-based materials in situ. (C) 2014 Elsevier Ltd. All rights reserved.

Any atomic-crystalline structure is a multilayer fractal structure and its topological dimension is d = ln5 / ln2 ≈ 1.809. From the point of view of a three-dimensional observer, the topological dimension will be d = ln13 / ln2 ≈ 5,1299250, and with the maximum tendency of iterative rotation and fractalization operations according to the algorithm of the original figures, two tetrahedra fill the elementary cubic cell., Любая атомно-кристаллическая конструкция представляет собой многослойную фрактальную конструкцию и ее топологическая размерность составляет d = ln5/ln2 ≈ 1,809. С точки зрения трехмерного наблюдателя топологическая размерность составит d = ln13/ln2 ≈ 5,1299250, а при предельном стремлении итеративных операций поворота и фрактализации по алгоритму исходных фигур – двух тетраэдров фрактально заполняется элементарная кубическая ячейка., Будь-яка атомно-кристалічна структура являє собою багатошарову фрактальную конструкцію і її топологічна розмірність складає d = ln5 / ln2 ≈ 1,809. З точки зору тривимірного спостерігача топологічна розмірність складе d = ln13 / ln2 ≈ 5,1299250, а при граничному прагненні ітеративних операцій повороту і фракталізаціі за алгоритмом вихідних фігур - двох тетраедрів фрактально заповнюється елементарна кубічна осередок.

Any atomic-crystalline structure is a multilayer fractal structure and its topological dimension is d = ln5 / ln2 ≈ 1.809. From the point of view of a three-dimensional observer, the topological dimension will be d = ln13 / ln2 ≈ 5,1299250, and with the maximum tendency of iterative rotation and fractalization operations according to the algorithm of the original figures, two tetrahedra fill the elementary cubic cell., Любая атомно-кристаллическая конструкция представляет собой многослойную фрактальную конструкцию и ее топологическая размерность составляет d = ln5/ln2 ≈ 1,809. С точки зрения трехмерного наблюдателя топологическая размерность составит d = ln13/ln2 ≈ 5,1299250, а при предельном стремлении итеративных операций поворота и фрактализации по алгоритму исходных фигур – двух тетраэдров фрактально заполняется элементарная кубическая ячейка., Будь-яка атомно-кристалічна структура являє собою багатошарову фрактальную конструкцію і її топологічна розмірність складає d = ln5 / ln2 ≈ 1,809. З точки зору тривимірного спостерігача топологічна розмірність складе d = ln13 / ln2 ≈ 5,1299250, а при граничному прагненні ітеративних операцій повороту і фракталізаціі за алгоритмом вихідних фігур - двох тетраедрів фрактально заповнюється елементарна кубічна осередок.

BaTiO3-ceramics are known as some of the most useful electroceramics with a various applications. In this study the effect of Er2O3 as additive on the microstructure and dielectric properties of doped BaTiO3 was investigated. The samples doped with 0.01 to 1.0 wt% Er2O3 were prepared using by conventional solid state procedure, and were sintered at 1350 degrees C for four hours. The microstructure of sintered specimens was investigated by SEM-5300 and capacitance and dielectric loss measurements have been done using LCR-metra Agilent 4284A in the frequency range from 20Hz to 1MHz. The microstructure study with low additive concentration shows abnormal grain size, with average grain size between 20-60 mu m. With the higher dopant concentracion the abnormal grain growth is inhibited and the grain size ranged between 5-15 mu m. The dielectric constant decrease with increase of dopant concentration and for all of the investigated samples ranged from 650 to 1600 at room temperature. The dissipation losses a linear decrease v.s frequency is mesured for all investigated samples. We applied a fractal method for the microstructure analysis. This method for analysis of the structure of ceramics provides a new approach for describing, predicting and modeling the grain shape and relations between the BaTiO3 ceramic structure and dielectrical properties.

BaTiO3-ceramics are known as some of the most useful electroceramics with a various applications. In this study the effect of Er2O3 as additive on the microstructure and dielectric properties of doped BaTiO3 was investigated. The samples doped with 0.01 to 1.0 wt% Er2O3 were prepared using by conventional solid state procedure, and were sintered at 1350 degrees C for four hours. The microstructure of sintered specimens was investigated by SEM-5300 and capacitance and dielectric loss measurements have been done using LCR-metra Agilent 4284A in the frequency range from 20Hz to 1MHz. The microstructure study with low additive concentration shows abnormal grain size, with average grain size between 20-60 mu m. With the higher dopant concentracion the abnormal grain growth is inhibited and the grain size ranged between 5-15 mu m. The dielectric constant decrease with increase of dopant concentration and for all of the investigated samples ranged from 650 to 1600 at room temperature. The dissipation losses a linear decrease v.s frequency is mesured for all investigated samples. We applied a fractal method for the microstructure analysis. This method for analysis of the structure of ceramics provides a new approach for describing, predicting and modeling the grain shape and relations between the BaTiO3 ceramic structure and dielectrical properties.

In this paper we present an image processing application for

A constitutive equation for viscoelastic behavior containing time derivatives of stress and strain to fractional order is obtained from a fractal rheological model. Equivalence between tree and ladder fractal models at long times is demonstrated. The fractional differential equation is shown to be equivalent to ordinary differential formulations in the case of a simple power-law response; the adequacy of such formulations to describe non-linearity has been demonstrated previously. The model gives a good description of viscoelastic behavior under all stress modes and will be extended in future to include aging effects. © 1994 Steinkopff-Verlag., SCOPUS: ar.j, info:eu-repo/semantics/published

A constitutive equation for viscoelastic behavior containing time derivatives of stress and strain to fractional order is obtained from a fractal rheological model. Equivalence between tree and ladder fractal models at long times is demonstrated. The fractional differential equation is shown to be equivalent to ordinary differential formulations in the case of a simple power-law response; the adequacy of such formulations to describe non-linearity has been demonstrated previously. The model gives a good description of viscoelastic behavior under all stress modes and will be extended in future to include aging effects. © 1994 Steinkopff-Verlag., SCOPUS: ar.j, info:eu-repo/semantics/published