4,474,312 research outputs found
A comparative review of processing methods for graphene-based hybrid filler polymer composites and enhanced mechanical, thermal, and electrical properties
No full textDirect numerical simulation of 'short' laminar separation bubbles with turbulent reattachment
No full textDirect numerical simulation of the incompressible Navier–Stokes equations is used to study flows where laminar boundary-layer separation is followed by turbulent reattachment forming a closed region known as a laminar separation bubble. In the simulations a laminar boundary layer is forced to separate by the action of a suction profile applied as the upper boundary condition. The separated shear layer undergoes transition via oblique modes and [Lambda]-vortex-induced breakdown and reattaches as turbulent flow, slowly recovering to an equilibrium turbulent boundary layer. Compared with classical experiments the computed bubbles may be classified as ‘short’, as the external potential flow is only affected in the immediate vicinity of the bubble. Near reattachment budgets of turbulence kinetic energy are dominated by turbulence events away from the wall. Characteristics of near-wall turbulence only develop several bubble lengths downstream of reattachment. Comparisons are made with two-dimensional simulations which fail to capture many of the detailed features of the full three-dimensional simulations. Stability characteristics of mean flow profiles are computed in the separated flow region for a family of velocity profiles generated using simulation data. Absolute instability is shown to require reverse flows of the order of 15–20%. The three-dimensional bubbles with turbulent reattachment have maximum reverse flows of less than 8% and it is concluded that for these bubbles the basic instability is convective in nature
Analisis Kapasitas Saluran Daerah Irigasi Lubuk Buntak Kecamatan Dempo Selatan Kota Pagar Alam
No full textBuilders in this irrigation area are a great opportunity to improve the economy of the community Lubuk Buntak. In order to improve and maintain agricultural production of food crops, the Pagar Alam City Government has until now built irrigation facilities and infrastructure both for the construction of new irrigation or rehabilitation in order to support the planned food security program. Irrigation channels located in the Lubuk Buntak irrigation area during the rainy season the water found on the irrigation canal has exceeded the capacity of the irrigation channel so that the irrigation can not work optimally, due to the high rainfall that occurs Thus the irrigation of Lubuk Buntak City Pagaralam irrigation area needs to be analyzed for the rainfall that occurs, in order to determine the ideal irrigation canal design and in accordance with the magnitude of the planned flood discharge, so that the planned irigassi channel works optimally. The purpose of this survey is about Rainfall Analysis, Calculation of planned flood discharge, Irrigation Channel Dimension, in this thesis using five Smirnov-Kolmogorov matching medotas from the calculation of the suitability of the method used is the gumbel method because the maximum difference (Dmax) -4, 70 <from Critical Value 41% (0.41), and analyze flowrate, so that the Irrigation Channel remains optimal for water resources can be utilized according to its designation, based on the parameters obtained. Next, identify the irrigation channel, calculate the intensity of rainfall, determine the flood discharge and the last design the channel dimensions for the area. The research carried out with a land area of 50 ha was obtained by the value of the intensity of the 50-year return rainfall of 530.76 m3 / sec, the planned flood return period of 50 years was 1.48 m3 / sec and the design of the channel dimension was (h) = 1, 42 m (B) = 1.40 m, (wf) = 0.29 m, and (TMA) = 1.17
The electrical behavior of functionalized multiwall carbon nanotubes decorated with polymer nanocomposites
No full textSimple and facile technique of Chemical Vapor Deposition technique were employed to synthesize the multiwall carbon nanotubes, their morphology and characteristics were proven ability to deliver excellent mechanical, electrical properties and multi-functional properties for diverse applications. In order to delivering the benefits of technology, acidified and functionalized multiwall carbon nanotubes as an efficient reinforcement in terms of polymer nanocomposite. New comprehensive strategy of appropriate dispersion and good interfacial adhesion between the functionalized multiwall carbon nanotubes and Polymer matrix are desire able and addressed. Functionalized multiwall carbon nanotubes have been confirmed by using “Scanning Electron Microscopy (SEM)” “Transmission Electron Microscopy (TEM)” “Fourier Transform Infrared Spectroscopy (FTIR)” and “Energy Dispersive X-Ray Spectroscopy (EDS)”. For effective and uniform dispersion of functionalized multiwall carbon nanotubes in Epoxy resin, various form of experimental strategies have been employed to achieve their maximum stability/strength and enhanced electrical properties. The engineering and adaptation of functionalized multiwall carbon nanotubes by epoxy provides not only excellent dispersion but also provide eminence interfacial adhesion. The mobility of the nanocomposite has been carried out by Hall analysis. The detailed investigation of electrical behavior of such nanocomposite also confirmed the insulative behavior of the matrix. It is expected that following product will contribute significantly in field of electronics sue to countless attractive features
Ultra-broadband wavelength conversion based on four-wave mixing in a Raman DFB fiber laser
No full textWe report highly efficient four-wave mixing (FWM) within a 30cm-long centre pi phase-shifted Raman DFB fiber laser with a continuous frequency tuning range of ~19.9 THz with the FWM conversion efficiency up to -25dB
Travelling along the public service co-production road: a bibliometric analysis and interpretive review
No full textA bibliometric analysis and an interpretive review have been undertaken to advance the debate on public service co-production and public value co-creation, conceiving them as the cornerstones of public service logic. The systematization of 114 articles, which were sorted in 4 clusters through bibliographic coupling, revealed a 'new normality' of public service delivery relying on citizens' involvement as value co-creators. Citizens and regular producers should be empowered to act as partners in co-designing and co-delivering public services. However, the interaction between citizens and regular producers generates value tensions, which should be addressed to avoid backlash on public value generation
Isatin-based ibuprofen and mefenamic acid Schiff base derivatives as dual inhibitors against urease and α–glucosidase: In vitro, in silico and cytotoxicity studies
No full textα-Glucosidase and urease inhibitors have emerged as crucial for developing therapeutic drugs targeting diabetes and gastrointestinal disorders. This study reports on new series of ibuprofen and mefenamic acid Schiff base derivatives incorporating isatin as dual inhibitors of α-glucosidase and urease enzymes. These synthesized derivatives (7a-r) were structurally characterized by 1H NMR, 13C NMR and HRMS (EI). Biological evaluation (IC50) identified several derivatives i.e., 7a (urease = 17.37 ± 1.37 μM, α-glucosidase = 44.1 ± 1.15 μM), 7j, (urease = 16.61 ± 1.37 μM, α-glucosidase = 81.2 ± 1.33 μM), 7o, (urease = 18.63 ± 1.27 μM, α-glucosidase = 70.3 ± 1.14 μM), 7r (urease = 11.36 ± 1.32 μM, α-glucosidase = 39.3 ± 1.17 μM), as dual inhibitors of urease (thiourea 21.37 ± 1.76 μM) and α–glucosidase (acarbose 375.82 ± 1.76 μM) enzymes. These bioactive derivatives were explored for cell viability studies against mononuclear cells revealing a good cytocompatibility. In silico molecular docking studies were also conducted to predict the binding mode of new derivatives with target enzymes that were found consistent with the results of in vitro research
Symmetry Analysis and Conservation Laws for the Class of Time-Fractional Nonlinear Dispersive Equation
No full textTime-fractional nonlinear dispersive equationLie symmetry methodConservation lawsWang, G., Kara, A.H. & Fakhar, K. (2015). Symmetry analysis and conservation laws for the class of time-fractional nonlinear dispersive equation. Nonlinear Dynamics, May 2015. DOI 10.1007/s11071-015-2156-4Furthermore, the author may only post his/her version provided acknowledgement is given to the original source of publication and a link is inserted to the published article on Springer's website. The link must be provided by inserting the DOI number of the article in the following sentence: “The final publication is available at Springer via http://dx.doi.org/[insert DOI]”.
Analisa Struktur Atas (Upper Structure) Jembatan Kaburejo Kota Pagar Alam
No full textOne means of transportation is a bridge that connects an area due to obstacles or road divides. There are many bridges in the City of Pagar Alam, one of which is in the Kaburejo area, the bridge in this area is less feasible for vehicles because it has a smaller bridge span than the highway. The purpose of this study is to do an upper structure re-design with a 6 m wide bridge and a 15 m long bridge span made with reinforced concrete construction that has a reinforced longitudinal beam which is an integral part of the vehicle floor so that it can meet the maximum traffic capacity. Bridge planning analysis is carried out on the bridge structure which includes the backrest, sidewalk floor, floor plate and main beam
Antitumor activity of zinc oxide nanoparticles fused with green extract of Nigella sativa
No full textZinc oxide nanoparticles have attracted considerable attention as promising candidates in various fields, especially in the realm of medical science. In the present experimental study, the co-precipitation method was used to synthesize chemical and green ZnO NPs. Zinc nitrate Zn (NO3)2 served as the main precursor, while sodium hydroxide (NaOH) and Nigella sativa extract were used to synthesize chemical and green Zinc Oxide nanoparticle, respectively. Then, the chemical and green fabricated Zinc Oxide nanoparticles were subjected to annealing at 400 °C and 550 °C temperature for a period of 2 hours respectively. After final product obtained, various characterization techniques were employed to validate the crystal structure, morphology, optical properties, and functional groups (e.g., OH stretching group, ZnO mode, etc.) via XRD, SEM, UV–Vis, and FTIR analysis. The Scherer formula was applied to calculate the average crystalline size of green and chemical fabricated Zinc Oxide nanoparticles, which confirmed the presence of the hexagonal wurtzite phase. Moreover, the fabricated products were finally tested for anticancer activity using MTT assay by optimizing cellular absorption against concentration. The MTT assay confirmed significant antitumor/anticancer efficacy against HepG2 cancer cells for both green actively and chemical fabricated Zinc Oxide nanoparticles superficial. The current development of this novel experimental strategy is anticipated to make a substantial contribution in the field of biomedical sciences, particularly in anticancer activity
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