148 research outputs found
Pressure fluctuations in centrifugal compressor diffusers
No full textThe unstable flow phenomenon like rotating stall and surge in centrifugal compressors occur at very low flow rates. These would cause unduly large vibrations in the turbo- machinery components and results in mechanical failure. It is important to detect this phenomenon and avoid it by means of early warning systems. An attempt has been made in this paper to study the pressure fluctuations using high frequency miniature transducers in vane and vaneless diffusers of a centrifugal compressor. The unstable nature of the flow is characterized. The observation from the measurements indicate the pressure fluctuations in the vane diffusers are getting amplified and carried to the exit of the diffuser whereas in the case of vaneless diffuser such a phenomena is not observed. The flow near the leading edge of diffuser plays an important role in diffuser performance. The unsteady pressure fluctuations in the diffuser are characterized in terms of instability parameter at various locations in the diffuser. The location where such an instability parameter is sensitive to the flow coefficient is identified as the diffuser throat. Through this instability parameter it is possible to provide early warning just before compressor goes into stall. (Author
Alternate stabilizers: solution towards reducing sulfate swell in expansive clay subgrades in Dallas district
No full textDue to the character of the original source materials and the nature of batch digitization, quality control issues may be present in this document. Please report any quality issues you encounter to [email protected], referencing the URI of the item.Includes bibliographical references.Issued also on microfiche from Lange Micrographics.The practice of using lime as a stabilizer during construction of pavements is widespread and is considered economical. However under certain conditions, the beneficial effects of lime stabilization is overridden. Proximity of gypsum deposits in the soil formations indicates the presence of soluble sulfates. In such areas, when lime is added for stabilization during construction operations, instead of the cementitious reactions, a heaving phenomenon results. This swell induced by lime-soluble sulfate reaction is attributed to the formation of expansive minerals and due to the disruption of the pozzolanic reaction. This research study investigated the material properties of soils in two problem areas, SH 161 and IH 635 when stabilized with commercially available nonstandard stabilizers. From the tests conducted, two of the additives tested namely, Roadbond ENI and EMC Squared were found to show superior qualities regarding strength, stiffness, permeability and other properties when compared to lime. Hence it is recommended that these two additives be used at these two sites in place of lime
The Prevalence and Factors Associated With Crude Herbs Use among Patients with Chronic Diseases: A Cross-Sectional Survey in Combination with Laboratory Analysis
No full textVirtual environments and autism: a developmental psychopathological approach
No full textIndividuals with autism spectrum disorders supposedly have an affinity with ICT, making it an ideally suited media for this population. Virtual environments (VEs) – both two dimensional and immersive – represent a particular kind of ICT that might be of special benefit. Specifically, this paper discusses the importance of psychological theory for VE designed for this population. I describe the contribution that different theories of autism (e.g., theory of mind, executive function, weak central coherence theory) have made and can make, as well as the potential of other non-autism-specific theories (e.g., embodied cognition). These technologies not only illuminate our understanding of autism, but they can also be used to develop new technologies for people without autism. So, as well as being an area of specialism, I argue that VE research in autism has extended – and will go onto – the boundaries of human–computer interaction more generally. This is because autism provides a unique window into human social communication and learning. Further, this field offers a chance for better inclusivity for individuals with autism within a digital society
Luxury as a Driver for New Urban Identities in Milan: Geographies, Spatial Practices, and Open Questions
No full textIn contemporary cities, the role of capital and private investors who finance interventions in the field of urban regeneration has become an increasingly important catalyst for the physical and social impacts of these transformations. This paper aims to point out the role of urban projects developed by luxury companies or stakeholders in consolidated urban regions. Starting by analysing the spatial distribution of luxury firms in Milan and composing a tentative classification system based on a variety of case studies, the author proposes a mental map of spaces shaped, occupied, transformed and infected by the sector within the contemporary metropolis. The resulting network of urban places sprawls out not only across centralized areas, but also in peripheral neighbourhoods, which interact with existing contexts, spatial and economic relationships as well as evident and hidden flows. From this basis, the contribution reflects on a set of luxury-driven practices and their impacts on urban identities. The reflection includes the role played by media technologies in these transformations and in the study of their development. The conclusions then discuss the role of luxury; whether it transforms the physical form of our city (its shape and patterns) or rather influences processes of transformation
Pronounced effects of the nominal concentrations of WO3 and Ag: WO3 nano-plates (obtained by a co-precipitation method) on their structural, morphological and optical properties
No full textInvestigation of organic solvents assisted nano magnesium oxide nanoparticles and their structural, morphological, optical and antimicrobial performance
No full textStudies on the Structural, Morphological, Optical, Electro Chemical and Antimicrobial Activity of Bare, Cu and Ag @ WO3 Nanoplates by Hydrothermal Method
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