967 resultados para Additive Manufacturing 3D Printing FDM TPU nanocompisiti
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The catalytic activity of Perovskite-type mixed oxides (LaCo03 . PrCo03 and SmCo03 ) for the reduction of cyclohexanone to cyclohexanol with 2-propanol (Meerwein-Ponndorf-Verley reduction) has been studied. The data have been correlated with the surface electron donor properties of these mixed oxides.
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The catalytic activity of some of the ABO3 (A = La, Pr and Sm, B= Cr, Mn, Fe, Co and Ni) perovskite-type oxides for the liquid phase reduction of ketone and oxidation of alcohol in 2-propanol medium has been studied. The data have been correlated with the surface electron donor properties of these oxides. The surface electron donor properties have been determined from the adsorption of electron acceptors of varying electron affinities on the oxide surface.
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Three dimensional (3D) composites are strong contenders for the structural applications in situations like aerospace,aircraft and automotive industries where multidirectional thermal and mechanical stresses exist. The presence of reinforcement along the thickness direction in 3D composites,increases the through the thickness stiffness and strength properties.The 3D preforms can be manufactured with numerous complex architecture variations to meet the needs of specific applications.For hot structure applications Carbon-Carbon(C-C) composites are generally used,whose property variation with respect to temperature is essential for carrying out the design of hot structures.The thermomechanical behavior of 3D composites is not fully understood and reported.The methodology to find the thermomechanical properties using analytical modelling of 3D woven,3D 4-axes braided and 3D 5-axes braided composites from Representative Unit Cells(RUC's) based on constitutive equations for 3D composites has been dealt in the present study.High Temperature Unidirectional (UD) Carbon-Carbon material properties have been evaluated using analytical methods,viz.,Composite cylinder assemblage Model and Method of Cells based on experiments carried out on Carbon-Carbon fabric composite for a temparature range of 300 degreeK to 2800degreeK.These properties have been used for evaluating the 3D composite properties.From among the existing methods of solution sequences for 3D composites,"3D composite Strength Model" has been identified as the most suitable method.For thegeneration of material properies of RUC's od 3D composites,software has been developed using MATLAB.Correlaton of the analytically determined properties with test results available in literature has been established.Parametric studies on the variation of all the thermomechanical constants for different 3D performs of Carbon-Carbon material have been studied and selection criteria have been formulated for their applications for the hot structures.Procedure for the structural design of hot structures made of 3D Carbon-Carbon composites has been established through the numerical investigations on a Nosecap.Nonlinear transient thermal and nonlinear transient thermo-structural analysis on the Nosecap have been carried out using finite element software NASTRAN.Failure indices have been established for the identified performs,identification of suitable 3D composite based on parametric studies on strength properties and recommendation of this material for Nosecap of RLV based on structural performance have been carried out in this Study.Based on the 3D failure theory the best perform for the Nosecap has been identified as 4-axis 15degree braided composite.
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Entre los años 2005 y 2006, se realizaron en Madrid dos interesantes encuentros internacionales denominados Tecnologías para una Museografía Avanzada, promovidos por el Consejo Internacional de Museos (ICOM), donde representantes de diversas instituciones culturales explicaban las influencias enriquecedoras que han aportado a sus exposiciones los nuevos medios tecnológicos en conjunto con la didáctica y la Museografía Interactiva como elementos mediadores de discurso. Representantes y Directores de instituciones como el Museo de Historia de Valencia (MHV), el Museo Arqueológico Provincial de Alicante (MARQ) o el Museo de la Cultura Bizantina de Grecia por ejemplo, han presentado las propuestas que en este contexto les ha permitido comunicar ideas refrescantes y nuevas estrategias para la compresión de diversos tipos de patrimonios. La premisa expuesta por ellos enfatizaba el pensamiento de que las nuevas tecnologías aunadas a la Museografía Interactiva, constituyen un apoyo didáctico a la hora de transmitir significados provenientes de los objetos patrimoniales para desarrollar y ampliar la comprensión del visitante en relación a los contenidos de las exposiciones. A este respecto, llama la atención la ausencia de museos especializados en Arte ante este tipo de discursos innovadores que suelen provocar en los visitantes soluciones educativas in situ, otorgando nuevos enfoques de las cosas, de la historia, de los objetos y de las generaciones pasadas.
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The study is undertaken by the researcher with the object of examining the remuneration pattern of executive personnel in the manufacturing public enterprises in Kerala so as to find out whether there is any rationale or criteria involved in remunerating executives. It is also envisaged to find out the pattern of executive remuneration in the various categories of industries and inter—industry disparities among the public sector enterprises. This is considered to be a very fruitful area for investigation, particularly in view of the generally prevailing notion that public sector executives in Kerala are not remunerated properly and glaring inequalities and disparities are existing among the various categories of industries and within the same industry. Therefore the study is to explore the criteria used for the determination of executive remuneration and the relative weightage of various factors such as size of the firm, rate of return sales volume etc of the organisation and various other factors such as qualification, experience, level of job and functions of executives. Further the study is extended to find out the role of 'pay' towards motivation and efficiency of the executive personnel
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The literature on the involvement of developing countries in trade has focused on the effects of different aspects of globalization on firms, regions and countries. The study attempts to examine how an export based industry, locallyembedded and originated on the basis of regional strengths has been inserted into the global trade framework. Though the unit of analysis is the manufacturing export firm in the region of Kannur, it represents the entire home textile export industry from the state of Kerala, as close to 90% of fabric exports in home furnishing material, textiles for upholstery and decoration and stitched or fused, and branded made ups are from the region. From a global perspective, how developing countries face newer trade restrictions and overcome non quota barriers by firm and region specific activities within a value chain framework is a major research area, which has already contributions from the Ludhiana woolen cluster (Tewari,1999 ) and the Tirupur cluster in India (Cawthorne, 1995). The study contributes to the value chain literature by examining the governance and upgrading as well as how firms benefit from linkages. India has a number of export oriented agglomerations or regions where firms have been serving export markets for many years. In many cases it is no longer the supply side policy actions that determine how they are able to penetrate new markets or expand existing market share. Based on this study it becomes possible to understand how the global value chain operates in these different industries to examine whether there is a danger of immiserisation of growth or low road growth
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This study was on women's industries programme in Kerala, to assess the involvement of manpower in this field and to analyse the difficulties and problems faced by the women entrepreneurs which impede the growth and smooth functioning of units. It was supported by the views of 275 women entrepreneurs of Kerala. Census method was adopted and only 58 per cent of units responded by supplying necessary details. Details were collected from these: units through mailed questionnaires designed for the purpose. The study highlights the profile of workers in the women's industrial units, but the profile of the entrepreneurs is neglected. Problems faced by women entrepreneurs are analysed under the following major heads viz., capital, raw materials, marketing, competition from other units and availability of power. But the conclusions drawn from the survey are not on proper empirical support. It also includes suggestions of entrepreneurs. The major findings of the study are as follows : Nearly 82 per cent of the women's industrial units are functioning throughout the year. Proprietory concerns and co—operative societies are the popular ones. Majority of the units are running on profit. Women's units are still in their infancy and so the problems faced by them are many. The characteristics of having other business or sister concerns is lacking among women entrepreneurs. Nearly 94 per cent of the employees are permanent. About four-fifth (81%) of the workers are full time employees. Only a very small proportion of the employees (1%) get a reasonable income that is above Rs.50O per month. The workers are very young and 63 per cent workers have no experience at all.
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The study evolved from the basic premise that the existing distribution structure is not adequate or adaptive to meet the needs of the expanding manufacturing sector and the emerging mass market. The hypothised causes of the problem are the following: marketing channels are not used for strategy differentiation by manufacturers: there are too many intermediaries in the channels; the distributive institutions are not adaptive; and there is very little control over the flow of products through the channels. These assumptions about the causes of the problem have been translated into specific hypotheses and tested with data. Empirical analysis, while supporting some of these hypotheses, challenges certain widely held notions. The ensuing summary presents the important findings, in the sequence in which they are discussed in the study.
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The present study investigates the benefits of stabilizing the stone mastic asphalt (SMA) mixture in flexible pavement with shredded waste plastic. Conventional (without plastic) and the stabilized SMA mixtures were subjected to performance tests including Marshall Stability, tensile strength and compressive strength tests. Triaxial tests were also conducted with varying percentage bitumen by weight of mineral aggregate (6% to 8%) and by varying percentage plastic by weight of mix (6% to 12% with an increment of 1%). Plastic content of 10% by weight of bitumen is recommended for the improvement of the performance of Stone Mastic Asphalt mixtures. 10% plastic content gives an increase in the stability, split tensile strength and compressive strength of about 64%, 18% and 75% respectively compared to the conventional SMA mix. Triaxial test results show a 44% increase in cohesion and 3% decrease in angle of shearing resistance showing an increase in the shear strength. The drain down value decreases with an increase in plastic content and the value is only 0.09 % at 10% plastic content and proves to be an effective stabilizing additive in SMA mixtures
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This work presents an efficient method for volume rendering of glioma tumors from segmented 2D MRI Datasets with user interactive control, by replacing manual segmentation required in the state of art methods. The most common primary brain tumors are gliomas, evolving from the cerebral supportive cells. For clinical follow-up, the evaluation of the pre- operative tumor volume is essential. Tumor portions were automatically segmented from 2D MR images using morphological filtering techniques. These seg- mented tumor slices were propagated and modeled with the software package. The 3D modeled tumor consists of gray level values of the original image with exact tumor boundary. Axial slices of FLAIR and T2 weighted images were used for extracting tumors. Volumetric assessment of tumor volume with manual segmentation of its outlines is a time-consuming proc- ess and is prone to error. These defects are overcome in this method. Authors verified the performance of our method on several sets of MRI scans. The 3D modeling was also done using segmented 2D slices with the help of a medical software package called 3D DOCTOR for verification purposes. The results were validated with the ground truth models by the Radi- ologist.
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The objective of the present study is the formation of single phase Zn1−xTMxO thin films by PLD and increase the solubility limit of TM dopants. The TM doped ZnO nanostructures were also grown by hydrothermal method. The structural and morphological variation of ZnO:TM thin films and nanostructures with TM doping concentration is also investigated. The origin and enhancement of ferromagnetism in single phase Zn1−xTMxO thin films and nanostructures using spectroscopic techniques were also studied. The dependence of ablation parameters on the structural and optical properties of ZnO thin films were studied
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We investigate spacelike maximal surfaces in 3-dimensional Lorentz-Minkowski space, give an Enneper-Weierstrass representation of such surfaces and classify those with a Lorentzian or Euclidian rotation symmetry.
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Information display technology is a rapidly growing research and development field. Using state-of-the-art technology, optical resolution can be increased dramatically by organic light-emitting diode - since the light emitting layer is very thin, under 100nm. The main question is what pixel size is achievable technologically? The next generation of display will considers three-dimensional image display. In 2D , one is considering vertical and horizontal resolutions. In 3D or holographic images, there is another dimension – depth. The major requirement is the high resolution horizontal dimension in order to sustain the third dimension using special lenticular glass or barrier masks, separate views for each eye. The high-resolution 3D display offers hundreds of more different views of objects or landscape. OLEDs have potential to be a key technology for information displays in the future. The display technology presented in this work promises to bring into use bright colour 3D flat panel displays in a unique way. Unlike the conventional TFT matrix, OLED displays have constant brightness and colour, independent from the viewing angle i.e. the observer's position in front of the screen. A sandwich (just 0.1 micron thick) of organic thin films between two conductors makes an OLE Display device. These special materials are named electroluminescent organic semi-conductors (or organic photoconductors (OPC )). When electrical current is applied, a bright light is emitted (electrophosphorescence) from the formed Organic Light-Emitting Diode. Usually for OLED an ITO layer is used as a transparent electrode. Such types of displays were the first for volume manufacture and only a few products are available in the market at present. The key challenges that OLED technology faces in the application areas are: producing high-quality white light achieving low manufacturing costs increasing efficiency and lifetime at high brightness. Looking towards the future, by combining OLED with specially constructed surface lenses and proper image management software it will be possible to achieve 3D images.