218 research outputs found

    Continuous thickening of non-ideal suspensions

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    The purpose of this study was to investigate the steady state continuous thickening of non-ideal suspensions such as sludges from water and wastewater treatment plants. Suspensions of high grade calcium carbonate, activated sludges, water softening sludges, and suspensions of fine glass beads were used. The suspensions were thickened in a closed, continuous, pi lot, thickening system. The sol ids flux theory was used successfully for predicting performance of the steady state continuous thickener from batch settling velocities of the suspensions. For the optimal performance of the thickener, effective stirring of concentration layers near the underflow level was found to be an absolute necessity. This was to prevent dilute solids from reaching the thickener bottom. Homogeneous distribution of the feed over the area of the tank was also essential. The feed concentration generally did not affect the thickening function. However, the interaction between thickening and clarification functions of the tank was established through the magnitude of feed concentrations. As the feed concentration decreased with fixed solids loading, the overflow velocity increased, and the clarity of overflow generally deteriorated.U.S. Department of the InteriorU.S. Geological SurveyOpe

    HDL composition, heart failure, and its comorbidities

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    Although research on high-density lipoprotein (HDL) has historically focused on atherosclerotic coronary disease, there exists untapped potential of HDL biology for the treatment of heart failure. Anti-oxidant, anti-inflammatory, and endothelial protective properties of HDL could impact heart failure pathogenesis. HDL-associated proteins such as apolipoprotein A-I and M may have significant therapeutic effects on the myocardium, in part by modulating signal transduction pathways and sphingosine-1-phosphate biology. Furthermore, because heart failure is a complex syndrome characterized by multiple comorbidities, there are complex interactions between heart failure, its comorbidities, and lipoprotein homeostatic mechanisms. In this review, we will discuss the effects of heart failure and associated comorbidities on HDL, explore potential cardioprotective properties of HDL, and review novel HDL therapeutic targets in heart failure

    The evaluating of efficacy of McKenzie exercises, Massage and foot Reflexology on pain and disability of men with mechanical chronic low back pain

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    Chronic low-back pain (CLBP) affects most people at some point in their lives. The aim of this study was to evaluate the efficiency of 3 methods which are popular and known as non-invasive way in rehabilitation of CLBP. 60 men in age of group 25-45 with CLBP were randomly divided into four groups (McKenzie, massage, reflexology and control) and instructed to perform McKenzie exercise for 8 week, massage and foot reflexology for 10 days. Patient were assessed by McGill pain questioner (MPQ) and Oswestry Disability Index (ODI), based on pain feeling and the ability to do routine activity of life before starting the study (Pre-test Data) and at the end of study procedure (post-test Data). Results were analyzed by Paired T test, one way ANOVA and Tukey post hock. There was no significantly difference in Pre-treatment session between the 4 groups. MPQ and ODI were significantly lower in post-treatment sessions as compared to pre-treatment values in experimental groups (McKenzie, massage and foot reflexology). Significant decrease in MPQ and ODI values were found in all experimental groups, but no difference in efficacy were found between these groups. However the result that reach from comparison between each of experimental group and control group, showed that the experimental groups were significantly effective. McKenzie exercise, massage and foot reflexology in men with mechanical chronic low-back pain reduce pain and improved disability. Researchers were not found any differences between these 3 methods as compare with each other. Due to the results, Authors suggest that may be using massage therapy or foot reflexology, for patients with CLBP, is better and more effective if therapists are looking for treating in shortest possible duration

    Aesthetic Automata: Synthesis and Simulation of Aesthetic Behaviour in Cellular Automata

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    This thesis addresses the computational notion of aesthetics in the framework of multistate two-dimensional cellular automata (2D CA). The measure of complexity is a core concept in computational approaches to aesthetics. Shannon's information theory provided an objective measure of complexity, which led to the emergence of various informational theories of aesthetics. However, entropy fails to take into account the spatial characteristics of 2D patterns; these characteristics are fundamental in addressing the aesthetic problem, in general, and of CA-generated patterns, in particular. This thesis proposes two empirically evaluated alternative measures of complexity, taking into account the spatial characteristics of 2D patterns and experimental studies on human aesthetic perception in the visual domain. The measures are extended to robustly quantify the complexity of multi-state 2D CA-generated patterns. The first model, spatial complexity, is based on the probabilistic spatial distribution of homogeneous/heterogeneous neighbouring cells over the lattice of a multi-state 2D cellular automaton. The second model is based on algorithmic information theory (Kolmogorov complexity) which is extended to estimate the complexity of 2D patterns. The spatial complexity measure presents performance advantage over information-theoretic models, specifically in discriminating symmetries and the orientation in CA-generated patterns, enabling more accurate measurement of complexity in relation to aesthetic evaluations of 2D patterns. A series of experimental stimuli with various structural characteristics and levels of complexity were generated by seeding 3-state 2D CA with different initial configurations for psychological experiments. The results of experimentation demonstrate the presence of correlation between spatial complexity measures and aesthetic judgements of experimental stimuli. The same results were obtained for the estimations of Kolmogorov complexity of experimental stimuli

    Heterogeneous cardiac sympathetic innervation gradients promote arrhythmogenesis in murine dilated cardiomyopathy

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    Ventricular arrhythmias (VAs) in heart failure are enhanced by sympathoexcitation. However, radiotracer studies of catecholamine uptake in failing human hearts demonstrate a proclivity for VAs in patients with reduced cardiac sympathetic innervation. We hypothesized that this counterintuitive finding is explained by heterogeneous loss of sympathetic nerves in the failing heart. In a murine model of dilated cardiomyopathy (DCM), delayed PET imaging of sympathetic nerve density using the catecholamine analog [11C]meta-Hydroxyephedrine demonstrated global hypoinnervation in ventricular myocardium. Although reduced, sympathetic innervation in 2 distinct DCM models invariably exhibited transmural (epicardial to endocardial) gradients, with the endocardium being devoid of sympathetic nerve fibers versus controls. Further, the severity of transmural innervation gradients was correlated with VAs. Transmural innervation gradients were also identified in human left ventricular free wall samples from DCM versus controls. We investigated mechanisms underlying this relationship by in silico studies in 1D, 2D, and 3D models of failing and normal human hearts, finding that arrhythmogenesis increased as heterogeneity in sympathetic innervation worsened. Specifically, both DCM-induced myocyte electrical remodeling and spatially inhomogeneous innervation gradients synergistically worsened arrhythmogenesis. Thus, heterogeneous innervation gradients in DCM promoted arrhythmogenesis. Restoration of homogeneous sympathetic innervation in the failing heart may reduce VAs

    Prediction of Stock Return Using Financial Ratios: A Decision Tree Approach

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    The purpose of this paper is to develop a model for prediction of present and prospect stock return using financial ratios. For this purpose, decision tree method was used. In this approach, a set of logical conditions in a hierarchical algorithmic model have been used for prediction or recognition of an event. Hereupon in this research, 70 percent of data were used to produce models in four popular decision tree algorithms (CHAID, ECHAID, QUEST and CRT) and the results of the tests were compared in 30 percent of residual of data with some of performance measures like accuracy, sensitivity and specificity. Information of 317 companies accepted in Tehran Stock Exchange was used in this study. The results indicated that ECHAID and CRT algorithms performed best in the prediction of present and CHAID algorithm in that of future. It was also shown that the models were better in that of present compared to that of future. The abilities of the models, however, were not significant in both cases. Accordingly, the hypothesis of the study was rejected

    Swarm intelligence approach in detecting spatially-independent symmetries in cellular automata

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    In late 1940's and with the introduction of cellular automata, various types of problems in computer science and other multidisciplinary fields have started utilising this new technique. The generative capabilities of cellular automata have been used for simulating various natural, physical and chemical phenomena. Aside from these applications, the lattice grid of cellular automata has been providing a by-product interface to generate graphical patterns for digital art creation. One notable aspect of cellular automata is symmetry, detecting of which is often a difficult task and computationally expensive. This paper uses a swarm intelligence algorithm - Stochastic Diffusion Search - to extend and generalise previous works and detect partial symmetries in cellular automata generated patterns. The newly proposed technique tailored to address the spatially-independent symmetry problem is also capable of identifying the absolute point of symmetry (where symmetry holds from all perspectives) in a given pattern. Therefore, along with partially symmetric areas, the centre of symmetry is highlighted through the convergence of the agents of the swarm intelligence algorithm. This technique is potentially applicable in the domain of aesthetic evaluation where symmetry is one of the measures
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