July 10, 2012 Tags: BERGMAN spaces, EQUATIONS -- Numerical solutions, FACULTY integration, HOLOMORPHIC functions, LINEAR operators, MATHEMATICAL models, NUMERICAL analysis
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This paper reports on an investigation of dimensional accuracy in additive manufacturing (AM) specifically an indirect metal laser sintering (IMLS) technique. An experimental programme with a series of simple parts has been carried out to establish dimensional accuracy of metal parts made using the three-dimensional (3-D) systems of indirect SLS process. In parallel basic engineering science and experimental has been used to analysed the relative loads experienced by different parts. The experimental data has been used to analyse the level of distortion experienced by parts which undergo infiltration is much less than that of parts which were deliberately not infiltrated; indicating that the early availability of liquid phase is key in avoiding distortion. Analysis has also shown that the propensity for distortion to develop during a sintering or sintering/infiltration step is directly related to the level of stress being experienced by the structure. These two findings show that the application of engineering science to Indirect Metal Laser Sintering could bring parts which are less distorted at the sintering/infiltration stage. [ABSTRACT FROM AUTHOR]
Read MoreJuly 10, 2012 Tags: ELECTRIC distortion, ELECTRIC interferenceLASER drilling, IRON -- Metallurgy, LASER ablation, LASERS -- Industrial applications, SINTERING
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Deep penetration laser welding is studied at processing speeds leading to the humping phenomenon. Matter melting, vaporization and re-solidification are considered through the implementation of user-defined functions (UDFs) used with a commercial computational fluid dynamics (CFD) Fluent code. The dynamic mesh method implementation allowed us to simulate regular hump formation. [ABSTRACT FROM AUTHOR]
Read MoreJuly 10, 2012 Tags: COMPUTATIONAL fluid dynamics, CRYSTALLIZATION, FLUID dynamics, LASER welding, SOLIDIFICATION, VAPORIZATION, WELDING
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Libertarian discourse questions bourgeois discourse and develops a sociocultural alternative that is often directly or indirectly related to science, medicine, health and disease (i.e. to biopower). The complex nature of libertarian thinking and biopower has led us to develop our analysis within a relational and eclectic theoretical-methodological framework that allows us to examine one of the devices of biopower – the process of medicalization. Many key explanatory traits of inter-war anarchist thinking may certainly be found in the process of medicalization, which was widely established in the early twentieth century, notwithstanding the fact that such processes have been marked by a wide variety of positions, some of which are alternative, such as those adopted to a large extent by the libertarian movement of that historical period. Thus, in this sense, our purpose is to analyse and understand to what extent discourses on the so-called ‘sexual reform’, as disseminated by the libertarian press in inter-war Spain, conditioned the processes of (de)medicalization; and also to what extent the latter conditioned discourses on sexual liberation. [ABSTRACT FROM AUTHOR]
Read MoreJuly 10, 2012 Tags: HEALTH, LIBERTY, TWENTIETH century, WAR
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We consider the generalized integration operator Due to image rights restrictions, multiple line equation(s) cannot be graphically displayed. where g is a holomorphic function on the unit disk 픻, 휑 is a holomorphic self map of 𝔻, n ∈ ℕ0. The boundedness and compactness of the operator from the space of Cauchy transforms to the Block-type spaces are characterized. [ABSTRACT FROM AUTHOR]
Read MoreJuly 10, 2012 Tags: BLOCH constant, CAUCHY problem, COMPACT spaces, Functional, GENERALIZATION, INTEGRAL transforms, INTEGRATION, OPERATOR theory
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Cardiovascular disease mostly in the form of atherosclerosis is responsible for 30% of all world deaths amounting to 17 million people per year. Atherosclerosis is due to the formation of plaque. The fatty plaque may be at risk of rupture, leading typically to stroke and heart attack. The plaque is usually associated with a high degree of lumen reduction, called a stenosis. The initiation and progression of the disease is strongly linked to the hemodynamic environment near the vessel wall. The aim of this study is to validate the flow of blood mimic through an arterial stenosis model with computational fluid dynamics (CFD) package. In experiment, an axisymmetric model constructed consists of contraction and expansion region that follow a mathematical form of cosine function. A 30% diameter reduction was used in this study. Particle image velocimetry (PIV) was used to characterize the flow. The fluid consists of rigid spherical particles suspended in waterglycerol- NaCl mixture. The particles with 20 µm diameter were selected to follow the flow of fluid. The flow at Re=155, 270 and 390 were investigated. The experimental result is compared with FLUENT simulated flow that account for viscous laminar flow model. The results suggest that laminar flow model was sufficient to predict flow velocity at the inlet but the velocity at stenosis throat at Re =390 was overestimated. Hence, a transition to turbulent regime might have been developed at throat region as the flow rate increases [ABSTRACT FROM AUTHOR]
Read MoreUsing fixed point methods, we prove the generalized Hyers-Ulam stability of homomorphisms in Banach algebras and of derivations on Banach algebras for the additive functional equation Due to image rights restrictions, multiple line equation(s) cannot be graphically displayed. for all m ∈ ℕ with m ≥ 2. [ABSTRACT FROM AUTHOR]
Read MoreJuly 10, 2012 Tags: ADDITIVE functions, BANACH algebras, FIXED point theory, FUNCTIONAL equations, GENERALIZATION, HOMOMORPHISMS (Mathematics), STABILITY
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Laser forming offers the industrial promise of controlled shaping of metallic and non-metallic components for prototyping, correction of design shape or distortion and precision adjustment applications. In order to fulfil this promise in a manufacturing environment the process must have a high degree of controllability, which can be achieved through a better understanding of its underlying mechanisms. One area of limited understanding is that of the variation in bend angle per pass observed during multi-pass laser forming along a single irradiation track, notably the decrease in bend angle per pass after many irradiations. Finite element (FE) modelling can be used to ascertain which of the various process parameters (such as graphite burn-off, geometrical effects, variation in absorption, etc.) contribute towards this phenomenon and subsequently the magnitude of their contribution. [ABSTRACT FROM AUTHOR]
Read MoreJuly 10, 2012 Tags: ABSORPTION, EXPANSION (Heat), FINITE element method, GRAPHITE, LASERS -- Industrial applications, STEEL, THERMAL stresses
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Salinity is one of the major factors limiting plant growth by imposing the osmotic, ion toxicity and oxidative stresses. The accumulation of osmoprotectants is a mechanism in which plants employ to protect tissue damages caused by salinity stress. The present study aimed to investigate the effect of two osmoprotectants (Sorbitol: Sor and Trehalose: Tre) on growth and physiology of rice (Oryza sativa L.) cvs. Khao Dawk Mali (KDML105; salt-sensitive) and Pokkali (PK: salt-tolerant) under NaCl stress. Under salt stress, KDML105 showed a significantly reduced growth and a large increase in the amount of hydrogen peroxide (H2O2), lipid peroxidation as indicated by Malondialdehyde (MDA) content and membrane Electrolyte Leakage (EL). The effects of salt were less severe in PK. Exogenously supplied Sor and Tre were able to enhance growth of salt-stressed KDML105 and alleviated the negative effects of salt by reducing H2O2 and MDA content. However, Sor and Tre did not have any beneficial effect on growth of PK plants. In some cases Sor worsened the salt-induced effects on lipid peroxidation and membrane damage. It can be concluded that exogenous Sor and Tre showed protective roles for salt-sensitive KDML105 but not salt-tolerant PK and the effects were more pronounced for Tre than Sor. [ABSTRACT FROM AUTHOR]
Read MoreJuly 10, 2012 Tags: MALONDIALDEHYDE, MEMBRANE lipids -- Peroxidation, RICE -- Yields, SALINITY, SALT-tolerant crops, SORBITOL, TREHALOSE
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Salinity is one of the most important abiotic stresses in many parts of the world. Salinity reduces growth by disturbing the physiological processes. Growth of the common bean (Phaseolus vulgaris L.) is sensitive to salinity. Only seedlings that have sufficient weight and hence sufficient strength for growth can withstand the effects of salinity. Sufficient strength is affected by transmitted materials from seed and the efficiency of this transmission. In order to identify which component of the bean’s seedlings is sensitive to the salinity, an experiment was conducted. The experiment tested for the effect of five levels of salinity on six genotypes of common beans. The experimental design was a randomized complete block design with four replications per treatment. Results showed that decreasing the seedling dry weight and seed reserve utilization efficiency, with increasing NaCl amount. Low levels of salinity up to 33 mM produced an increasing in seedling dry weight. The route of the changes in the weight of mobilized seed reserve and the seed reserve depletion percentage were in reverse with the seedling dry weight. These results clarity showed that seed reserve utilization efficiency is the main component (trait) for toleration of salinity. Therefore, breeding programs should be focused on the sensitive component, i.e., SRUE and the breeding of this component results in the breeding of SLDW in common bean. [ABSTRACT FROM AUTHOR]
Read MoreJuly 10, 2012 Tags: BLOCK designs, COMMON bean, DROUGHTSPHYSIOLOGICAL aspects, SALINITY, SEEDS -- Growth, SEEDS -- Physiology
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