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Identifi cation and characterization of components
Get PDFIn the information age, components in all kinds of electronic products occupy an important position, in particular, somecommon electronic components, electronic products is essential to the basic material. The performance of various typesof components, features, the use of the scope of the function of the electronic product design and manufacturing hasa very important role especially in the past period. Along with the rapid development of the electronics industry, newrequirements and components industry is also constantly using new materials. New technology has introduced newproducts for the development of electronic products to open up new ways. This chapter will be a number of commonlyused electronic components according to its type, performance characteristics and testing. As a brief introduction andstrive to have a wide range of components have a general understanding in order to facilitate product design and expandthe range of components used
Polyethylene plastic production process
Get PDFPolyethylene has become the most important polyolefi n plastic with excellent mechanical properties, processingproperties and chemical resistance. It is used in the production of film, packaging and pipe. However, the nonpolarproperty and low rigidity of polyethylene limits its application in certain fi elds. The new progress of chemicalmodifi cation, physical modifi cation and modifi cation of polyethylene were reviewed. Chemical modifi cation includesgraft modification, copolymerization modification, crosslinking modification, chlorination, chlorosulfonationmodification and plasma modification. There are different methods of polyethylene production which include highpressure polyethylene, medium pressure polyethylene and low pressure polyethylene. All three methods have their ownbenefi ts and shortcomings which coexist in the industry
Fabrication and investigation of polymer-based carbon composite as gas diffusion layer of proton exchange membrane of fuel cells
Get PDFCarbon paper is one of the most important component in polymer electrolyte PEM fuel cells. In this research, we report two methods of manufacturing carbon papers that do not need the steps of carbonization and graphitization are common steps in carbon paper. At first method (mixing method), the short carbon fibers have a random distribution in the composite and in the second method (fabric method), the long carbon fibers are oriented in planar configuration .In order to investigate on the properties, the effect of paper thickness and expanded graphite value have been considered and compared with Toray carbon paper. The characterization is performed by scanning electron microscope, maximum pore size, mean pore size, permeability, electrical conductivity, flexibility, and performance (I-V) curve. The results show that mixing method resulting in a higher electrical conductivity, pore size, and permeability, as well as I-V curve similar to Toray paper. In addition, the cost estimates and flexibility test show that both fabric and mixing methods results in a much lower cost, due to removing the graphitization and carbonization steps, and more flexible samples in comparison to Toray paper
Designing Paste Thickeners for Copper Flotation Tailings, Using Bed depth Scale-up Factor
Get PDFAim:The paste thickener could increase the water recovery and reduce the environmental impacts in tailings dam. The present work aimed to find the appropriate scale-up factor for bed depth to design paste thickener for copper tailings, using a lab glass cylinder and an operating pilot column. The thickening tests were carried out on the flotation tailing samples obtained from the Sarcheshmeh and Miduk copper mines located in Iran. Based on the industrial conditions, the values of influential parameters for paste thickener used in these experiments were pH=11 and feed solid=10 %. Flocculant type was NF43U and used as 25g/t with dosage of 0.25 gt. The unit area of Sarcheshmeh and Miduk paste thickeners were designed as 0.057 and 0.047m2/t/day, respectively. Based on the dry feed rates to each paste thickener as 7920 and 4320 t/day, the thickener's diameters were determined as 23.9 and 16.1 meters which are similar to the actual thickener’s diameters (24 and 16 meters), respectively. In addition to unit area, the bed depth is also important in the paste thickeners design. Hence, the ratio of industrial to lab unit bed volume for Sarcheshmeh paste thickener was obtained 75 which was equal to the ratio of industrial to lab bed depth (bed depth scale-up factor exclusively for copper flotation tailings). This procedure was validated by using the Miduk sample. The bed depth in the paste thickeners was determined as 7.5 meters, by using the bed depth scale-up factor which was comparable to the actual bed depth (8 meters). This research confirmed that the bed depth scale-up factor is able to correctly determine the bed depth of industrial paste thickeners for copper tailings.
COMMON FIXED POINT THEOREMS USING COMPATIBLE MAPS IN D-METRIC SPACES OVER TOPOLOGICAL SEMI FIELD
Get PDFIn this paper, we introduce the concepts of compatible mappings in D-metric spaces over Topological semi field and prove the common fixed point theorem
Role of the P2Y6 receptor of UDP in the modulation of murine dendritic cell functions and Th1 polarisation of the immune response
Get PDFNumerous studies have demonstrated the role of uridine diphosphate (UDP) and its P2Y6 receptor in the inflammatory reaction and innate immunity. However, the importance of the P2Y6 receptor in the adaptive immune response remains unclear. In this study, we demonstrate that the P2Y6 receptor is functionally expressed in murine bone marrow dendritic cells (BMDC). UDP induced a Ca2+ transient in these cells that was decreased in P2Y6-deficient mice. UDP also increased the endocytosis of fluorescein isothiocyanate-dextran (FITC-dextran) and amplified the secretion of interleukin 12-p70 (IL-12p70) induced by CpG; these responses were abolished in P2Y6-deficient mice. In vivo experiments showed that the serum level of specific IgG2c after immunisation with ovalbumin was decreased in P2Y6-deficient mice, while the level of specific IgG1 was unchanged. These data suggest that the P2Y6-mediated effects of UDP on myeloid dendritic cells play a role in the in vivo Th1 skewing of the immune response
Medicines development in the Asia Pacific region
Get PDFThe Asia Pacific region is an extremely diverse region, characterized by heterogeneity from a number of aspects, including culture, religion, economics, landscapes, and languages. This also applies to the standard of medical care and the regulatory requirements for approval of drugs in the region. Developed economies such as Japan and Australia have requirements which are not dissimilar to those of the EU and USA, but still have their own unique requirements. The developing economies all have their own requirements. In the ASEAN region there is harmonization of the dossier format, but each country still has local requirements. The region has seen significant growth in clinical trial activity, both to satisfy local registration and safety requirements and to help accelerate global trial patient recruitment. There is a clear need for training in all aspects of medical, regulatory, clinical and safety aspects of medicines development, which is being addressed through several organizations and at different locations in the region
A study of temperature profiles and trends as revealed by COSMIC RO technique and balloon –borne radiosonde instrument
Get PDFThis research presents atmospheric temperature profiles and trends retrieved using COSMIC RO technique and balloon-borne radiosonde instrument in 2007 and a few cases during 2017. By effectively using ‘wet’ temperature product available at COSMIC Data Analysis and Archive Center (CDAAC) website, an analysis has been made to present temperature profiles and trends at various regions including, Indian, Taiwan and Japan. A one-to-one correspondence is, clearly, seen between temperature profiles retrieved with COSMIC RO and radiosonde instrument. But, few and dominant differences in temperature profiles are found below at an altitude of ~5 km and above around tropopause (~16-17 km). The dominant differences found at below ~5km could be due to the inhomogeneous distribution of humidity present, generally, at the tropical regions, whereas above the tropopause altitudes, differences might be due to the ionospheric residual correction as reported by other researchers. Further, temperature monthly trends at various regions show distinct characteristics including, a sharp temperature inversion up to tropopause altitude. In addition, it is also observed maximum temperatures (peaks) during the northern summer seasons (May, June, July, and August) and minimum temperatures (troughs) during the northern winter seasons (November, December, January, and February) near to the surface of the Earth. Interestingly, although it is generally observed that the tropopause altitude is located at ~ 16-17 km at various regions, a keen observation reveals that distinct seasonal and latitudinal variations can be witnessed. With this case study, it may be concluded that the COSMIC RO technique is able to provide very accurate measurement, which reiterates its importance as a powerful tool to explore the Earth’s atmosphere on the local and global scale
Applying high-resolution visible imagery to satellite melt pond fraction retrieval: A neural network approach
Get PDFDuring summer, melt ponds have a significant influence on Arctic sea-ice albedo. The melt pond fraction (MPF) also has the ability to forecast the Arctic sea-ice in a certain period. It is important to retrieve accurate melt pond fraction (MPF) from satellite data for Arctic research. This paper proposes a satellite MPF retrieval model based on the multi-layer neural network, named MPF-NN. Our model uses multi-spectral satellite data as model input and MPF information from multi-site and multi-period visible imagery as prior knowledge for modeling. It can effectively model melt ponds evolution of different regions and periods over the Arctic. Evaluation results show that the MPF retrieved from MODIS data using the proposed model has an RMSE of 3.91% and a correlation coefficient of 0.73. The seasonal distribution of MPF is also consistent with previous results
An attitude determination method based on convected Euler angle error model for SINS/CNS integrated system
Get PDFThe attitude determination method plays an important role in SINS/CNS integrated system for spacecraft. Since the misalignment angels are indirect measurements, the misalignment angle model used in the existing attitude determination method can cause transformation errors. To solve the problem, an attitude determination method based on convected Euler angle error model for SINS/CNS integrated system is proposed. The attitude error propagation is analyzed, and the convected Euler angle error model is derived. Furthermore, the state equation of SINS/CNS integrated system is established. The Kalman filter estimates and compensates the Euler angle errors. Finally, simulation results verified that the proposed method can improve the attitude accuracy compared to the conventional misalignment angle method