209,044 research outputs found
Cloud computing for business
No full textIn a new study, U-M business professor M. S. Krishnan says that cloud computing helps small businesses.http://deepblue.lib.umich.edu/bitstream/2027.42/85028/1/krishnan_nov_10.mp
Data for: Enhanced elastomer toughness and fracture properties imparted by chemically reactive flat nanoparticles
No full textThe files named "Fsweep_NAME", where "NAME" refers to NC45, NG45, CB45, CF45-PARL, CF45-PERP, and BASE, contain frequency-sweep dynamic mechanical analysis (DMA) data acquired at 30 °C for the respective elastomers. Measurements were made in the dual-cantilever mode using a strain amplitude of 0.1%.The files named "Tsweep_NAME" contain temperature-sweep DMA data acquired at a constant heating rate of 3 °C/min, a strain amplitude of 0.1 %, and a strain frequency of 1 Hz.The files named "TENSILE_NAME" contain stress vs. strain data acquired on dumbbell specimens with a gauge length of 20 mm, a width of 2 mm, and a thickness of 2 mm, at a constant extension rate of 500 mm/min. The files named "CYCLIC_TENSILE_NAME" contain stress vs. strain data for these specimens using a triangular strain waveform, consisting of loading and unloading of the dumbbell specimen at a constant displacement rate of 50 mm/min. All the tensile testing data were acquired at room temperature.The files named "LOAD_DISP_NAME" contain normalized load vs. displacement data acquired on SENT specimens, as discussed in ref. 1. The load is normalized by the initial area of the uncracked ligament. The files named "R_CURVE_SENT_NAME" contain R-curve data for the SENT specimens. The normalized strain energy is obtained by dividing the strain energy, U, by the initial area of the uncracked ligament. All the fracture testing data were acquired at room temperature.Reference:1. M. Torabizadeh, Z.A. Putnam, M. Sankarasubramanian, J.C. Moosbrugger, S. Krishnan, The effects of initial crack length on fracture characterization of rubbers using the j-integral approach, Polymer Testing, 73 (2019) 327-337
Effect of Mach number on the structure of turbulent spots
No full textDirect numerical simulations have been performed to study the dynamics of isolated turbulent spots in compressible isothermal-wall boundary layers. Results of a bypass transition scenario at Mach 2, 4 and 6 are presented. At all Mach numbers the evolved spots have a leading-edge overhang, followed by a turbulent core and a calmed region at the rear interface. The spots have an upstream-pointing arrowhead shape when visualized by near-wall slices, but a downstream-pointing arrowhead in slices away front the wall. The lateral spreading of the spot decreases substantially with the Mach number, consistent with a growth mechanism based on the instability of lateral shear layers. Evidence for a supersonic (Mach) mode substructure is found in the Mach 6 case, where coherent spanwise structures are observed under the spot overhang region
On the merging of turbulent spots in a supersonic boundary-layer flow
No full textThe complex transition flow physics associated with the merging of turbulent spots in a Mach 2 boundary-layer has been studied using direct numerical simulation. Dynamics of an isolated turbulent spot, merging of laterally displaced spots, and merging of two spots in tandem are considered. The coherent structures associated with the wingtip region of the spot are found to play a major role in destabilising the surrounding laminar fluid. In the merging of laterally displaced spots a strong velocity defect, resulting in unstable inflectional velocity profiles, is observed in the interaction zone. These local inflectional instabilities within the interaction region trigger new large scale coherent structures. During the inline merging, the calmed region behind the tail of the downstream spot is found to suppress the growth of the upstream spot. The upstream spot is ultimately engulfed by the downstream spot
Interview with Vijoo Krishnan
No full text<< Vijoo Krishnan is a farmers' rights activist serving as the Joint Secretary of the All India Kisan Sabha. He is also the Head of Department at St. Joseph's College, Bengaluru and a former JNUSU President from the Students' Federation of India (SFI), a student political organisation. He was also a member of the the Gender Sensitisation Committee Against Sexual Harassment (GSCASH) at JNU. This material is exhibited as part of the Memories of Change exhibition
バイノールヲボカクニユウスルヒカリオウトウセイフセイショクバイ：ソノデザイントマンニッヒガタハンノウオヨビアザ-フリーデル-クラフトハンノウヘノオウヨウテンカイ
No full textKrishnan C.G., Kondo M., Nakamura K., et al. Photoswitchable Chiral Cation-Binding Catalyst: Photocontrol of Catalytic Activity on Enantioselective Aminal Synthesis. Organic Letters 24, 2670, American Chemical Society, (2022); https://doi.org/10.1021/acs.orglett.2c00741.Krishnan C.G., Kondo M., Yasuda O., et al. Light-controlled pKa value of chiral Brønsted acid catalysts in enantioselective aza-Friedel-Crafts reaction. Chemical Communications 59, 9956, Royal Society of Chemistry, (2023); https://doi.org/10.1039/D3CC02719H
Investigation of material and mechanical properties of Al alloy and Al based MMC parts produced by DMLS for industrial application
No full textAdditive Manufacturing (AM) is the process of joining materials layer upon layer to produce parts from CAD model. Direct Metal Laser Sintering (DMLS) is an AM process in which metallic parts can be produced. The knowledge of material and mechanical properties are important for producing lightweight and functional parts. Hence, this thesis focuses on characterizing material and mechanical properties of a lightweight alloy processed by DMLS, and using it as metal matrix for producing composites in DMLS process. AlSi10Mg was selected as lightweight alloy and it is similar to an A360 cast alloy in chemical composition. The morphology and size distribution of the AlSi10Mg starting powder was investigated by using Field Emission Scanning Electron Microscope (FESEM) and laser granulometry, respectively. Chemical composition of the AlSi10Mg powder was analyzed by using Inductive Coupled Plasma test. Material characterization of AlSi10Mg specimen produced by DMLS was carried out by using optical microscope, FESEM and X-ray Diffraction technique (XRD). Thereafter, mechanical properties such as hardness, tensile strength and Charpy impact energy were evaluated. Effect of different post processing operations on mechanical properties of AlSi10Mg parts were also investigated. Due to the very fine microstructure of the AlSi10Mg parts produced by DMLS process, nanoindentation measurements were performed. Investigation of process parameters and their effect on final density and hardness of AlSi10Mg specimens based on Design of Experiments (DOE) approach was carried out. Regression analysis was also conducted. Effect of the heat treatment (e.g. precipitation hardening T6) on the AlSi10Mg parts was also investigated. Composite materials offer better properties comparing to traditional materials. The Metal Matrix Composite was produced by DMLS process. The matrix was of AlSi10Mg and 10 wt% SiC was used as ceramic reinforcement. The microstructure of the composite was studied by using optical microscopy and FESEM. Evaluation of mechanical properties of the composite specimens was carried out. Finally, the production of a complex shape lightweight structure by DMLS was studie
Data for 'Encapsulated Textile Organic Solar Cells Fabricated by Spray Coating'
No full textThis data supports the paper Li, Y., Arumugam, S., Krishnan, C., Charlton, M., & Beeby, S. (2018). Encapsulated Textile Organic Solar Cells Fabricated by Spray Coating.
Solution based processes such as screen printing and spray coating are established processes for fabricating organic solar cells (OSCs) on flexible polymer substrates. However, realizing a flexible solar cell on a textile substrate remains a significant challenge due to the properties of the textile itself, which can present an absorbent, rough and fibrous surface. The textile also limits processing temperatures which can reduce functional materials performance. In this work, we demonstrate an optimized fabrication approach using entirely spray coating to fabricate textile OSCs with a power conversion efficiency (PCE) of 0.4 %. An interface layer is first deposited on the standard woven textile that forms a smooth supporting layer for the subsequent spray coated functional layers. A top encapsulation layer is deposited on top of the fabricated textile OSCs, which improves the durability and life time of the OSCs is evidenced by cyclic bending test.</span
Dr. Duane M. Jackson, Morehouse College, July 2011
No full textThis video is a conversation with Dr. Duane M. Jackson. Dr. Jackson talks about his paper, "Recall and the Serial Position Effect: The Role of Primacy and Recency on Accounting Students' Performance." Jackie Daniel, AUC Woodruff Library, is the interviewer
Ways of thinking influencing the teaching and learning of evolution
No full textPresentation given by Georgia Southern faculty member Amanda L. Glaze with Katie Green, Brandon Foster, Margaret M. Lucero, Jose M. Pavez, Sandhya Krishnan, and David F. Jackson at National Association of Research in Science Teaching Baltimore, MD.
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