Multi-scale rheological model for discontinuous phenomena in materials under deformation conditions

A study of possibilities given by the developed Cellular Automata–Finite Element (CAFE) multi-scale model for prediction of the initiation and propagation of micro-shear bands and shear bands in metallic materials subjected to plastic deformation is described in the paper. Particular emphasis in defining the criterion for initiation of micro-shear and shear bands, as well as in defining the transition rules for the cellular automata, is put on accounting for the physical aspects of those phenomena occurring in two different scales in the material. The proposed approach led to the creation of the real multi-scale model of strain localization. This model predicts material behavior in various thermo-mechanical processes. Selected examples of applications of the developed model to simulations of metal forming processes, which involve strain localization, are presented in the paper. An approach based on the Smoothed Particle Hydrodynamic, which allows to overcome difficulties with remeshing in the traditional CAFE method, is presented in the paper as well. In this approach remeshing becomes possible and mesh distortion, which limits application of the CAFE method to simple deformation processes, is eliminated.

Possibilities to include in numerical simulation stochastic and discontinuous phenomena occurring in material

Simulation of materials processing has to face new difficulties regarding proper description of various discontinuous and stochastic phenomena occurring in materials. Commonly used rheological models based on differential equations treat material as continuum and are unable to describe properly several important phenomena. That is the reason for ongoing search for alternative models, which can account for non-continuous structure of the materials and for the fact, that various phenomena in the materials occur in different scales from nano to mezo. Accounting for the stochastic character of some phenomena is an additional challenge. One of the solutions may be the coupled Cellular Automata (CA) – Finite Element (FE) multi scale model. A detailed discussion about the advantages given by the developed multi scale CAFE model for strain localization phenomena in contrast to capabilities provided by the conventional FE approaches is a subject of this work. Results obtained from the CAFE model are supported by the experimental observations showing influence of many discontinuities existing in the real material on macroscopic response. An immense capabilities of the CAFE approach in comparison to limitations of the FE method for modeling of real material behavior is are shown this work as well.

Towards a digital representation of physical phenomena to assess comfort in future environments

This paper presents the concept and a test implementation of a digital representation of the physical world designed to assess comfort quality in
future environments. An integrated set of physical phenomena is modeled three-dimensionally to investigate the dynamic behavior of design objects
holistically.

The formulation supports the integration of computational simulation in the performance-based design process. It employs the principles of
geometrical and physical selfcontainedness to avoid that complex geometrical and physical circumstances have to be specified at design time. The concepts of congeneric cells and congeneric conjunctions are
introduced to simulate various physical phenomena simultaneously with a uniformly structured set of equations.

The concept, the prototype implementation and selected test cases are presented. Although it was not possible to implement all features and model parts completely, the research and the discussion of its achievements make valuable contributions towards more effective integration of computational simulation in the performance-based design process.

Towards a universal and integrated digital representation of physical phenomena: a model to investigate comfort and energy efficiency in future environments

This thesis describes the exploration and the development of computational means to investigate the behaviour of design objects before they are available for investigation in the physical world. The motivation is to inform the design process about the design object's performance in order to achieve better--more performance-oriented--design outcomes in the sense of energy efficiency and comfort performance than can be achieved by conventional design techniques.

A search for sources of preferential attachment phenomena in e-business

This paper presents and empirical study in which we examine the process of preserential attachment as it applies to business enterprises on the World Wide Web.  Using randomly selected business Web pages as nodes and their inbound links as edges, we explre the role of parked domain names in link creation and preferential attachment at very granular levels.  Our research leads us to the conclusion that the abundance of parked domain name sites does not present a plausible explanation for preferential attachment.

Many-body dissipative particle dynamics simulation of wetting phenomena

With the development of the simulation of particle dynamics, the traditional dissipative particle dynamics (DPD) method can not satisfy the needs of research in static or dynamic wetting phenomena. However, the Many-body DPD approach extends the ability of the traditional method to simulate the interface between solid and liquid or some other situation. In this paper, we propose a Many-body DPD program to simulate the solid-liquid interface and get satisfactory results.

Simulating crowd phenomena in African markets

Crowd simulation is an important feature in the computer graphics field. Typical implementations simulate battle scenes, emergency situations, safety issues or add content to virtual environments. The problem stated in this paper falls in the last category. We present a crowd simulation behavioural model which allows us to simulate identified phenomena in popular local African markets such as narrow street flows and crowd formation around street performances. We propose a three-tier architecture model enable to produce intentions, perform path planning and control movement. We demonstrate that this approach produces the desired behaviour associated with crowds in an African market, which includes navigation, flow formation and circle creation.

Study on the fouling phenomena of poly(vinylidene fluoride) (PVDF) membrane by protein and yeast

This sub-collection is the result of an investigation into the mechanism of organic fouling in membrane filtration processes. In this experiment, poly(vinylidene fluoride) (PVDF) membranes were used to filter two types of organic foulants, protein and yeast with a concentration of 50mg/l and 20 mg/l, respectively, from suspension in a dead-end filtration cell. These model foulants were stained with fluorescent dyes before filtration. This dataset contains a stack of images of the fouling layer on the PVDF membrane surface captured by a confocal laser scanning microscope (CLSM) and its associated acquisition software. This dataset would be useful to researchers who are investigating the membrane organic fouling mechanism so that new membrane materials and new anti-fouling surface treatment technologies can be developed for water and wastewater industry in the future.

Study on the fouling phenomena of poly(vinylidene fluoride) (PVDF) membrane by protein and sodium alginate

This sub-collection is the result of an investigation into the mechanism of organic fouling in membrane filtration processes. In this experiment, poly(vinylidene fluoride) (PVDF) membranes were used to filter two types of organic foulants, protein and sodium alginate with a concentration of 50mg/l and 40 mg/l, respectively, from suspension in a dead-end filtration cell. These model foulants were stained with fluorescent dyes before filtration. This dataset contains a stack of images of the fouling layer on the PVDF membrane surface captured by a confocal laser scanning microscope (CLSM) and its associated acquisition software. This dataset would be useful to researchers who are investigating the membrane organic fouling mechanism so that new membrane materials and new anti-fouling surface treatment technologies can be developed for water and wastewater industry in the future.

Study on the fouling phenomena of poly(vinylidene fluoride) (PVDF) membrane by protein, yeast and sodium alginate

This sub-collection is the result of an investigation into the mechanism of organic fouling in membrane filtration processes. In this experiment, poly(vinylidene fluoride) (PVDF) membranes were used to filter three types of organic foulants, yeast, protein and sodium alginate with a concentration of 50mg/l, 40mg/l and 20 mg/l, respectively, from suspension in a dead-end filtration cell. These model foulants were stained with fluorescent dyes before filtration. This dataset contains a stack of images of the fouling layer on the PVDF membrane surface captured by a confocal laser scanning microscope (CLSM) and its associated acquisition software. This dataset would be useful to researchers who are investigating the membrane organic fouling mechanism so that new membrane materials and new anti-fouling surface treatment technologies can be developed for water and wastewater industry in the future .

Elementary phenomena, body disturbances and symptom formation in ordinary psychosis

In my research, I examined body phenomena in psychosis by exploring onset, triggering events and stabilisation in psychosis. I concluded that body disturbances can be important indicators for the onset of psychosis and, that these disturbances provide a framework for better understanding the recovery from psychosis, particularly in schizophrenia.

Adult attachment insecurities are related to obsessive compulsive phenomena

Obsessive-compulsive disorder (OCD) is one of the most disabling and highly prevalent anxiety disorders. Cognitive models implicate maladaptive beliefs such as inflated sense of responsibility, perfectionism, importance/control of thoughts in the maintenance of the disorder, but little research has investigated factors that may lead to these beliefs. This paper investigated whether a dysfunctional attachment system may be one such factor, by examining how adult attachment orientations (dimensions of attachment anxiety and avoidance) relate to OCDrelated cognitions, OCD symptoms, and depression. Using structural equation modeling in a student sample (N = 446), the present study found evidence for a mediational model, where attachment dimensions contributed to OCD symptoms via OCD-related cognitions, while controlling for depression. The paper discusses the association between adult attachment orientations and OCD symptoms in the context of current cognitive-behavioral theories of OCD.

The relationship between neuropsychological performance, cognitive confidence, and obsessive-compulsive phenomena : a pilot study

Drawing on neuropsychological and cognitive-behavioral approaches to Obsessive-Compulsive Disorder (OCD), the present study examined the association between memory performance, cognitive confidence, and OCD phenomena. Forty-six analogue participants completed a series of self-report questionnaires and neuropsychological tasks before and after a manipulation of confidence in memory It was found that cognitive confidence predicts OCD symptoms over and above the influence of depressive symptoms and other OCD-related beliefs. Participants reported higher levels of cognitive confidence following positive feedback on the manipulation task. However, changes in cognitive confidence following the manipulation task were not reflected in neuropsychological performance. Implications for theory and treatment are discussed.