15,495 research outputs found
Different cytokines regulate antigen uptake and presentation of a precursor dendritic cell line
No full textEstablishment of a cell line with features of early dendritic cell precursors from fetal mouse skin
No full textThe impacts of social media on destination branding. Case study based on Hanoi city – the capital of Vietnam.
No full textThe purpose of the thesis was to discover the current situation of social media in destination branding with a use case of a developing city in Vietnam while weighing the impacts of social media marketing brings to advertise the destination.
In the theoretical chapters of the thesis, the author aimed to understand the general state of social media at the moment. Moreover, the author wanted to understand the impacts that social media has on the image of Hanoi. So that he could utilize the advantages and minimize the disadvantages affecting directly to the image of Hanoi. There were a few studies that only focus on the general picture of the relationship between social media marketing and destination branding. However, they did not concentrate on the specific purpose of the effectiveness of social media marketing in a destination. According to the data which was collected after six interviews, the author had an overview of the current impacts of social media marketing and the ways of improving them from the experts in this field.
Combined with previous studies, the influences of social media on the destination have been seen. Besides, there are more suitable proposals to improve and promote the image of Hanoi in the future. At the end chapter of the thesis, the author also gave a few pieces of advice as a guideline to build an effective social media marketing plan
Wettability of molten Sn-Bi-Cu solder on Cu substrate
No full textThe wetting behavior of a new Sn-Bi-Cu Pb-firee solder on Cu substrate was investigated by sessile drop method under an Ar-H(2) flow in the temperature range from 493 K to 623 K. The contact angle curves tested at 548 K and 623 K are found to fit exponential rule very well. However. the contact angle curve tested under493 K is not well consistent with exponential rule, for which the spreading course may be classified into three stages. Equilibrium contact angles between Sn-Bi-Cu solder and Cu substrate decrease monotonously with the increase in temperature, which are 28 degrees, 24 degrees and 18 degrees at 493 K. 548 K and 623 K, respectively. The results show that 69.5Sn30Bi-0.5Cu/exhibits good wettability on Cu substrate. Intermetallics formed at the 69.5Sn-30Bi-0.5Cu/Cu interface are identified as Cu(6)Sn(5) adjacent to the solder and Cu(3)Sn adjacent to the Cu substrate, respectively. Formation of intermetallic seems to improve strong wetting of the substrate by the solder. (C) 2009 Elsevier B.V. All rights reserved
Ordering of organic molecules on templated surfaces
No full textThis thesis describes the controlled growth of molecular nanostructures using modified metallic and semiconductor surfaces. The Ag/Si(lll)-(root3 x root3),the Sn/Cu(100) surface alloy system and the Bi/Si(100) nanolines and (2xn) surfaces were all investigated as suitable substrates for the controlled growth of pentacene, (C22H14) or trimesic acid, (C6H3(COOH)3) organic molecules. The following techniques were used in this study; Scanning Tunnelling Microscopy (STM), Low Energy Electron Diffraction (LEED), Normal Incident X-Ray Standing Waves (NIXSW) and Temperature Programmed Desorption (TPD).
The room temperature growth and ordering of trimesic acid on the AgfSi(ll1)-(root3 x root3) surface was investigated. An oblique unit cell was determined and a model proposed for the highly ordered close-packed domains.
The discovery of a new submonolayer phase on Sn/Cu(100) and the re-examined known phase are discussed. New models for these reconstructions are proposed. Adsorption of trimesic acid at room temperature on the clean substrate the lowest Sn coverage phase were studied. Two new Sn coverage dependent structures were discovered and bonding schemes in upright and flat orientations are discussed.
BifSi(100)-(2xn) surface was exploited as a template for the ordered growth of pentacene, which exhibited orientation specific adsorption. The Bi/Si(100)-(2xn) single domain surface created on vicinal silicon was used to test the suitable of Daresbury 4.2 beamline for NIXSW Imaging experiments and the quality of the results are discussed
Nanoindentation investigation on creep behavior of amorphous Cu-Zr-AI/nano crystalline Cu nanolaminates
No full textBerkovich nanoindentation experiments have been performed on amorphous /nanocrystalline nanolaminates with individual Cu-Zr-Al layers (45 nm 90 nm 225 nm) and Cu layers (7.5 nm & 15 nm). Elastic modulus hardness and indentation morphology were detected and compared to those of single Cu-Zr-Al thin film. Creep deformation was systematically investigated at various holding depths and loading rates. For the sample with thinner amorphous layer a more pronounced creep deformation was observed and it was confirmed to be due to the size effect of Cu-Zr-Al layers and the addition of Cu layers. The creep deformation was identified to be history-independent through applying various loading rates. The strain rate sensitivities were calculated from the steady-state creep and a sharp enlargement appeared as the amorphous layer reduced down to 90 nm implying a transition of creep mechanism in nanolaminates. (C) 2017 Elsevier B.V. All rights reserved
Cu isotopic compositions in Elsholtzia splendens: Influence of soil condition and growth period on Cu isotopic fractionation in plant tissue
No full textThis study investigates the magnitude and direction of Cu isotopic fractionation in the Cu-tolerant, strategy I plant, Elsholtzia splendens, considering the effect of soil condition and plant growth cycle. Uptake of Cu by E. splendens from soil was found to favor light Cu isotopic enrichment (delta Cu-65 < 0 parts per thousand) due to reduction at the soil root interface. The magnitude of fractionation between soil and plant was found to be dependent on free Cu ion species in soil solution correlated with pH value of soil other than the phytoavailable component of soil or total soil for the same parent soil
Competitive Advantages and Disadvantages in Romania’s Agri-Food Trade -Trends and Challenges
No full textThe paper is part of the studies concerning trade patterns and agri-food foreign trade policies in the EU enlargement context, aiming to assess the competitive trade advantages and disadvantages of the Romania’s agri-food products in the foreign trade relations. The analysis focuses on the challenges of the trade liberalization and its influence on the intensification of the commercial exchanges, the supply diversification and on the trade balance equilibrium, faced by Romania’s agri-food sector over the transition and pre-accession period. The structural reforms of the transition and EU accession preparations induced paramount changes in Romania’s agri-food trade pattern, i.e. a fluctuating evolution of the agri-food foreign trade, either in correlation with the variations in the agricultural supply, the performance deficiencies of the agri-food sector that provoked disequilibria on the export market, or with the effect of political changes upon the trade flows. The recent integration in the Single Market recalls a special attention on the opportunities for the competitive producers to attract benefits offered by the enlarged access possibilities and the openness to third countries. In this context, an in-depth analysis of the bilateral trade relation between Romania and EU has been performed by using an alternative method of the comparative trade advantage index, based on the one developed by Vollrath [1]. The results emphasize the identification of either the competitive agri-food trade potential, or of the sensitive zones that could be affected by the external competition post-accession, as well as the needed improvements in the Romanian agri-food sector’s competitiveness.Agri-food trade, competitiveness, comparative trade advantage index., International Relations/Trade,
Micro-cantilever Bending Test of Sintered Cu nanoparticles for Power Electronic Devices
No full textThe application of microporous sintered copper (Cu) as a bonding material to replace conventional die-attach materials in power electronic devices has attracted considerable interest. Many previous studies have focused on the effect of processing parameters (temperature, time, pressure) on the microstructure evolution of sintered Cu. However, there are only a few studies with regard to the mechanical properties of sintered Cu. As the die-attach layer undergoes thermal and mechanical stress during its application, it is essential to investigate the micro-scale mechanical properties of sintered Cu. Fracture toughness is a measure of the resistance of a material to crack propagation under predominantly linear-elastic conditions, which is an essential parameter for predicting fracture failure. As cracks and defects are difficult to avoid during fabrication and application processing for sintered Cu, which will definitely cause a significant effect on micromechanical properties. Thus, it is essential to reveal the effect of microstructure on fracture toughess of sintered Cu nanoparticles.Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Electronic Components, Technology and Material
Interfacial properties of Cu/SiO2 using a multiscale modelling approach in electronic packages
No full textInterfacial properties of Cu/SiO2 in semiconductor devices has continued to be the subject of challenging study for many years because of its difficulties in experimentally quantifying the critical strength of interface. In this paper, a multi-scale modeling approach is built to characterize the interfacial properties between Cu and SiO2. In this system, the Cu and SiO2 are bonded together by three types of chemical bonds, Cu-OO, Cu-O, and Cu-Si, which cause three atomistic interfacial structures. For Cu-O and Cu-Si bonded interfaces, the fracture occurs exactly at the interface, however, the fracture for Cu-OO bonded interface occurs at copper layer near the interface, which indicate two different fracture criterions coexist in Cu/SiO2 system. And, the calculated interfacial strength at macroscale is in agreement with available experimental results.Accepted author manuscriptElectronic Components, Technology and Material
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