Experimental investigations on forming limit diagram of ultra thin SS 304 steel : effect of circular grid size, sheet orientation, punch size and deformation speed

In the present work, SS 304 sheet of 200 μm thickness was used to experimentally evaluate the forming limit diagram (FLD). In this context, a sub-size limiting dome height (LDH) test setup was developed to deform rectangular specimens of different widths using a 30 mm hemispherical punch. Further, effect of various parameters such as change in circular grid size, stretching direction with respect to rolling direction of the sheet, punch size and deformation speed on limiting strains was investigated. It was observed that there was marginal change in limiting strains due to the change of punch diameter from 30 mm to 50 mm. The FLD0 level changed approximately 7.5% and 6.8% with the change in punch diameter and stretching direction respectively. It was also found that the FLD0 value increased by 15% with change in circular grid diameter from 2.5 mm to 2.0 mm. However, a negligible change in the limiting strains was noted when the grid diameter was further reduced to 1.0 mm. There was negligible change in the FLD0 level with increase in punch speed from 4 mm/min to 100 mm/min, but approximately 13% decrease was found when the punch speed was further increased to 400 mm/min. Moreover, the LDH, strain distribution and failure strains were also analyzed in context of formability

Profitability, productivity and price recovery patterns in the U.S. telecommunications industry

We undertake a study where we examine changes in the profitability, productivity and price recovery of firms in the U.S. telecommunications industry over a sixteen-year period. We assess the performance of thirty-three major companies in the local-exchange sector over six time periods 1975, 1978, 1981, 1984, 1987 and 1990, using a performance analysis model which disaggregates the profitability measure into two components: productivity and price recovery. We demonstrate the computation of performance using this technique. Our study indicates that the opening up of markets has had a significant impact on different dimensions of performance in the telecommunications industry, also validating a number of theoretical assumptions about the impact that industry changes are expected to have on firms.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/43575/1/11151_2004_Article_BF00163594.pd

Rare Case of Nasal Vault Oncocytic Cystadenoma

Background: Oncocytic Cystadenomas are a rare benign pathology often found to arise from the salivary glands, reported more commonly in minor salivary glands, but even more rarely in major salivary glands and the larynx. This is the first known report of a nasal vault oncocytic cystadenoma in a pediatric patient. Methods: Case Report and Literature Review. Case presentation: A 10-year-old female presented with a mass involving the left nasal vestibule that caused nasal obstruction and a visible external abnormality. MRI imaging revealed a cystic lesion in the anterior nasal cavity that was rim enhancing with a bright T2 signal that appeared to arise from the nasal mucosa. She was taken to the operating room for endoscopic-assisted removal of the lesion. Pathology showed an oncocytic cystadenoma. On follow-up clinic visit, she is doing well with no signs or symptoms of recurrence. Conclusion: The authors present the first reported case of a pediatric patient with nasal vault oncocytic cystadenoma. In other head and neck locations, these cysts are generally benign and only cause symptoms related to their location and proximity to other vital structures. Surgical endoscopic management was effective for resection

Quantum Electrodynamics in a Topological Waveguide

While designing the energy-momentum relation of photons is key to many linear, nonlinear, and quantum optical phenomena, a new set of light-matter properties may be realized by employing the topology of the photonic bath itself. In this work we experimentally investigate the properties of superconducting qubits coupled to a metamaterial waveguide based on a photonic analog of the Su-Schrieffer-Heeger model. We explore topologically induced properties of qubits coupled to such a waveguide, ranging from the formation of directional qubit-photon bound states to topology-dependent cooperative radiation effects. Addition of qubits to this waveguide system also enables direct quantum control over topological edge states that form in finite waveguide systems, useful for instance in constructing a topologically protected quantum communication channel. More broadly, our work demonstrates the opportunity that topological waveguide-QED systems offer in the synthesis and study of many-body states with exotic long-range quantum correlations

Quantum Electrodynamics in a Topological Waveguide

While designing the energy-momentum relation of photons is key to many linear, nonlinear, and quantum optical phenomena, a new set of light-matter properties may be realized by employing the topology of the photonic bath itself. In this work we experimentally investigate the properties of superconducting qubits coupled to a metamaterial waveguide based on a photonic analog of the Su-Schrieffer-Heeger model. We explore topologically induced properties of qubits coupled to such a waveguide, ranging from the formation of directional qubit-photon bound states to topology-dependent cooperative radiation effects. Addition of qubits to this waveguide system also enables direct quantum control over topological edge states that form in finite waveguide systems, useful for instance in constructing a topologically protected quantum communication channel. More broadly, our work demonstrates the opportunity that topological waveguide-QED systems offer in the synthesis and study of many-body states with exotic long-range quantum correlations