Applied Mechanics and Materials Vol. 749

Abstract: The application properties of magnetic cores made of Fe_72.8Si_11.2B_10.8Cr_2.3C_2.9 powders was studied. The amorphous Fe_72.8Si_11.2B_10.8Cr_2.3C_2.9 powders were prepared by a spinning water atomization process (SWAP), and the cores further were fabricated from those powders by a hydraulicpressing process. The particle size distribution of powders was about 10 to 20 μmand the alloy powders would crystallize during milling. For the cores, the maximum permeability μ_i was 14 and quality factor Q was 84 between 100kHz - 2000kHz for 1 wt.% Na₂SiO₄solidified with H-epoxy at 300°C. The minimum coercivityH_cwas 0.22 Oe at 1 wt.% Na₂SiO₄ with PVB consolidated at 150 °C, and the maximum saturation magnetization B_m was 7.64×10² G for 2 wt.% Na₂SiO₄ with H-epoxy at 300 °C.

Abstract: Recently, the display industry is focusing on making bendable or flexible displays with higher quality and larger area. Ultimately, there is a very high possibility that future displays will be rollable. The biggest problem with rollable displays is the fabrication of a polarizer film to prevent reflection of the OLED. To develop a rollable display, the display should be made of material with a very thin thickness, like that of paper. However, the thickness of the polarizer film used for displays is only approximately 180 μm. This means that the film is too thick to be applied to rollable displays. If a polarizer of wire grid type, which we investigate in this study, is used, it can reduce the thickness of this film to a value under approximately 1 μm. One research result has been to discover that Fe₃O₄ is a very slightly absorptive material. Especially, most research into Fe₃O₄ thin films has concentrated on its characteristics in nanotubes. So, our purpose in this research is to investigate the deposition process of Fe₃O₄ thin-film under various conditions using an E-beam evaporator; we intend to compare these various processes with each other after measuring the refractive index.

Abstract: In this project we have represented the reduction of the ancillary heavy oil substance in the rotary kilns in the new foundry of the new Ferronickel in Drenas, with the use of the ancillary substance Pet Kok. The experimental and industrial research have been analyzed during the years 2008,2009,2010,2011,2012 and 2013. The chemical composition of heavy oil was analyzed in the INKOS Institute in Obiliq, while the composition of Pet Kok in the laboratory of the new foundry in the new Ferronickel in Drenas. The use of Pet Kok reduces the attachment of the substances in the rotary kilns walls, and it impacts the benefit of the calcines in a higher temperature and quality. The big amount of moisture of the Fe-Ni ore and the lack of an adequate dryer to reduce the moisture of the ore are two of the many factors of the large amount of ancillary substances in the rotary kilns. On 12.05.2011 pet kok has begun to be used in rotary kiln two, while in rotary kiln one pet kok has been used from 1.09.2012, the favorable impact of the use of pet kok in the technological process in the new foundry of the new Ferronickel in Drenas in the qualitative iron-nickel affected the reduction of the amount of heavy oil.

Abstract: The problem of formation of a material, which has the coefficients of attenuation and scattering close or coinciding with the same coefficients for some other predetermined material, was considered. A computer processing of values of these coefficients for a big set of various materials has been carried out and their dependence on radiation energy value was studied. The conclusion was drawn about probability of successful solution of the problem in some cases and difficulties, which may occur were pointed out. A set of computer calculations carried out for some specific materials is provided.

Abstract: The flexible dye-sensitized solar cells have a need to improve adhesive property in each layer in order to increase efficiency of this solar cell. Flexible surface with Polyethylene naphthalate (PEN) were modified by using surface treatment from developed the low-pressure high-frequency Plasma Chemical Vapor Deposition system in order to improve adhesive characteristic. The oxygen plasma treatment can improve adhesive property of Polyethylene naphthalate (PEN) films and also cleaning surface. We were using the mixture of Ar and O₂ gas for plasma treatment with oxygen gas flow rate from 0.1 L/min. to 0.5 L/min. while Ar gas flow rate was set at 10 L/min. and 5 minute for treatment time. The results indicate that using low-pressure high-frequency Plasma Chemical Vapor Deposition system can be possible improvement adhesive characteristic of PEN films with radical increased on films.

Abstract: 1-Benzyl-3-methyl-imidazolium hexafluoroantimonate (BMH) was newly synthesized and characterized with FT-IR, 1H-NMR. We synthesized catalysts fulfill requirements for a rapid cure at a moderately elevated temperature in curing the epoxy resin for neat diglycidyl ether bisphenol A (DGBEA). The cure behavior of this resin was investigated at elevated temperature and cure temperature in the presence of 0.5, 1.0, 2.0 wt% of 1-benzyl-3-methyl-imidazolium hexafluoroantimonate (BMH) by mean of differential scanning calorimeter (DSC). Chemical conversion as function of temperature and amount of BMH (0.5, 1.0, 2.0 wt%) were determined from DSC. It was found that BMH were superior latent thermal catalyst for catinonic curing which have a good thermal stability.

Abstract: Recently, pyroelectric polymers i.e. polyvinyledene fluoride (PVDF) and its copolymer of P(VDF-TrFE), including poly (vinylidene fluoride-hexafluoropropylene) - P(VDF-HFP) have been reconsidered greatly for energy conversion or energy harvesting. This work study the effect of temperature on mechanical and dielectric properties of thin film P(VDF-HFP). All samples were prepared by solution casting method then stretched and poled at 35 μm/s of velocity and 60 MV/m of electric field, respectively. The dielectric properties were determined by LCR meter varying on temperature (30°C to 155 °C) at 1 kHz. For mechanical properties were investigated by dynamic mechanical analysis (DMA) which explained the viscoelastic behavior and obtained a glass transition temperatures (T_g) of all samples. The range of operated temperatures is-100 °C to 100 °C in rate 5°C/min. The results showed a tiny shift of T_g among non-stretched, stretched, and polarized P(VDF-HFP) which is related to their degree of crystallinity and ability of polarization on dielectric behavior of sample. Correlation of the temperature dependence of mechanical and dielectric properties under stretching and poling of these polymers are also discussed.

Abstract: We carried out ab initio electronic structure calculations in the frameworks of the Density Functional Theory (DFT) to study the electronic structures and hyperfine interaction of muonium (Mu) in imidazole (C₃H₄N₂) and 1–methylimidazole (CH₃C₃H₃N₂). The local energy minima and hyperfine interactions of the Mu trapped at the three studies sites were determined by performing geometry optimization procedure. The results show the total energies for all three studied sites are close to one another. The Mu hyperfine interactions were also determined, with the corresponding values vary from 343.00 MHz to 471.28 MHz for the imidazole–Mu cluster, and from 380.21 MHz – 465.57 MHz to 475.93 MHz for the cluster of 1–methylimidazole–Mu, respectively.

Abstract: Undoped and Sb doped SnO₂ nanoparticle thin films were synthesized by sparking process. The nanoparticles were continuously deposited onto the substrate by varying the number of sparking cycles ranging from 10-30 and the deposited film were subsequently annealed at 500 °C in tube furnace under air atmosphere for 1 h. The effect of Sb doped SnO₂ nanoparticles thin film on their structure and optical characteristics were investigated. The optical properties of the nanoparticles thin films have been studied from transmission spectra. An average transmittance of the thin films decrease from 70% to 50% when the doping level increased from 0 to 7 %Sb doped SnO₂. Opitical band gap energy of thin films were found to vary in range of 3.85-3.89 eV which the energy band gap decrease with the increasing Sb doping concentration. From the experimental data, the reduction of optical transmittance spectra in the antimony doped SnO₂ thin films make it suitable for generation of window layer coating and prevent unwanted absorption in UV range.

Abstract: Ellipsometry is power instrument for testing several properties of thin films. Advantage and attractiveness of these optical studies consist in that they are non-destructive and non-disturbing. High sensitivity to surface state allows us to monitoring properties of films beginning from atomic scale as in-situ and as ex situ. Ellipsometry give us information about film thickness, and film composition, and its surface morphology. From analysis of ellipsometric spectra it is possible get data about zone structure of semiconductor materials, such as energy of critical points, absorption edge location, and crystallinity. Speed of data acquisition is sufficient high to test dynamic of film growth. Ellipsometric measurements are quite simple but its interpretation requires special software. In this paper some possibilities of ellipsometric method are demonstrated in examples film polymorphism.