Матрічні моделі у дослідженні ринкового стану промислового підприємства

Україна, як відомо, історично є промисловою державою, тобто промисловий сектор складає основу національної економічної системи та обумовлює певні тенденції у розвитку усіх сфер економічної діяльності. Так, на 01.01.2013р. вітчизняний промисловий ринок охоплює приблизно 300 тис. виробничих підприємств, які займають десь 60% усього працюючого населення, з них близько 50% працює на великих підприємствах. Проте більше 40% промислових підприємств є збитковими; обсяг промислової продукції, що призначена для використання споживачами промислового ринку, за останні п’ять років зменшилася удвічі і складає сьогодні менше 10%

Cross Flow past Circular Cylinder with Waviness in Confining Walls near the Cylinder

Two dimensional flow past circular cylinder confined by walls with local waviness near the cylinder has been studied. The aim of the present study is to identify the ability of the waviness to control vortex shedding, for which two different waviness configurations such as in-phase configurations (IPC) and out-phase configurations (OPC) are considered. Further, the effect of location of the local waviness with respect to the cylinder has also been studied. Air is the working fluid and the flow is assumed to be laminar and incompressible at Re=200. The finite volume based CFD solver Ansys Fluent (Version 15.0) is used for the computations. Flow characteristics such as drag, lift and Strouhal number are computed. Interesting shedding characteristics and drag reduction are observed due to the presence of local waviness. However, the significant factor is the location of waviness in the confining walls that leads to complete suppression of shedding. Among various locations and configurations of waviness studied, waviness in downstream with OPC3 suppresses the vortex shedding completely with reduced drag

Synthesis, Structural and Optical Properties of PVP Encapsulated CdS Nanoparticles

Highly monodispersed CdS nanoparticles using polyvinyl pyrrolidone (PVP) as the capping agent were synthesised by chemical coprecipitation method. The surface‐modified cadmium sulfide nanoparticles were found to be remarkably stable. In the presence of PVP, cubic phase with small grain size of CdS were observed in XRD. The peaks were identified to originate from (111), (220) and (311) planes of CdS, respectively. The crystallite size of the synthesised CdS nanoparticles was about 3 nm calculated from the (111) plane of XRD pattern and it was also confirmed through HRTEM. Morphology and elemental mapping of the synthesised nanoparticles were studied by SEM and EDX analyses. Increase in the band gap with decrease in the particle size was observed from the reflectance mode UV spectrum, which confirms the quantum confinement effect. From the photoluminescence studies, enhanced near‐band‐edge blue light emission and significantly reduced defect‐related green emission were observed. Longitudinal optical (LO) phonon modes, corresponds to pure CdS were observed in Raman spectrum

Redetermination of poly[μ-chlorido-hepta­chlorido-μ3-l-proline-μ2-l-proline-tetra­mercury(II)]

The asymmetric unit of the title compound, [Hg4Cl8(C5H9NO2)2]n, consists of four HgCl2 units and two L-proline ligands in the zwitterionic form. In each HgCl2 unit, the HgII ion is strongly bonded to two Cl atoms, and the HgII ions in two of the HgCl2 units are chelated by O atoms of two l-proline ligands, with one strong and one weak Hg—O bond. In the crystal structure, HgCl2 and L-proline units are linked to form an extended chain along the a axis. The chain structure is further stabilized by N—H⋯Cl hydrogen bonds, and the chains are arranged in layers parallel to the ab plane. The structure of the title compound was originally determined by Ehsan, Malik & Haider [(1996). J. Banglad. Acad. Sci. 20, 175] but no three-dimensional coordinates are available