Investigation in to Properties of Polyurethane Closed Cell by High Loading of SiO 2 Nanoparticles

Abstract In this research the composition of polyurethane closed cell (PUCC

WordHunch : Architecture and design of an android application

I detta projekt har en arkitektur och användargränssnitt skapats för Tweakers HB. Arkitekturen och designen kommer att användas till ett ord-baserat spel. Det här projektet är en del utav ett ännu större projekt som omfattar en klient-server android applikation. Hela klienten kommer att skapas utifrån arkitekturen som beskrivs i projektet. Användargränssnittdesignen och dess implementation skapar vyn. Arkitekturen har utvecklats med Astah Community Edition och dokumenterats med hjälp av Microsoft Word 2013. Den modell som valdes är MVC mönstret och den har anpassats en del för att vara lämplig just den här applikationen. Designen har arbetats fram med hjälp av Eclipse, Extreme programming och testdriven utveckling. Med hjälp av Eclipse har plugins som är essentiella laddats ned för att skapa användargränssnittet. Själva användargränssnittets design skapades mestadels i Photoshop men också med hjälp av inbyggda verktyg som följde med android sdk tools. Alla krav som ställdes har uppfyllts och är vältestade. Designen blev inte bara uppskattad estetiskt utan praktiskt, detta bekräftades genom att testarna var med på utvecklingen kontinuerligt och gav oss feedback.This project creates a user interface and architecture for Tweakers HB. The architecture and design will be used to create a word based game. The project is a smaller part of an even larger project which is a client-server android application. The client will be created from the architecture designed in this project. The user interface design and the solutions presented will make up the view. The architecture has been designed with Astah Community Edition and documented with Microsoft Word 2013. The model that was chosen for this application is the well-known MVC pattern which was slightly reconfigured to be fitting for this application. The user interface has been developed with Eclipse, Extreme programming and test-driven development. Plugins which are essential for the developement have been downloaded via Eclipse. The design of the user interface was mostly created with Photoshop but also with the help of android sdk tools. All of the requirements were well tested and successfully met. The design is not only beautiful but also simple and easy to navigate. This has been confirmed by the testers who have been following the project and providing constant feedback

Evaluation of structural, optical and physical properties of polyurethane composites doped with metal alkoxides

In this research, polyurethane (PU)/tetraethyl orthosilicate (TEOS) composite was prepared via one-step polymerization method using different concentrations of TEOS in PU. The structural, optical and physical properties of PU composite were characterized by SEM imaging, FT-IR spectroscopy, water uptake, Raman spectroscopy and optical microscopy imaging of synthesized samples. The SEM results showed that by adding TEOS to the PU, the cell and window size of synthesized samples decreased. This result was also observed in the optical micrographs. The bonding characteristics of PU/TEOS composites were analyzed using Raman and FT-IR spectra. According to the FT-IR spectra, the degree of phase separation (DPS) and hydrogen bonding index, R, in 800 μl TEOS/PU had the highest R and DPS factors. By adding different concentrations of TEOS to PU, the apparent density decreased but the real density increased. The total, open and closed porosity of the synthesized samples were calculated. At low loading of TEOS in PU, the open porosity of the samples increased. The PU/TEOS composites may be promising candidates for absorbing sound

Structural and optical properties of cordierite glass-ceramic doped in polyurethane matrix

The cordierite (2Mg.2Al2O3.5SiO2) was synthesized by the Pechini method and added to polyurethane open cell (PUOC) foam in three different percentages. Fourier transform infrared spectroscopy (FTIR) was employed to evaluate the bonding characteristics of PUOC/cordierites. The effect of temperature on the synthesis of cordierite and crystallographic structure of the final product were studied by XRD. By increasing the temperature, the widths of the XRD peaks decreased, approaching the single crystal spectrum. The SEM results show that by increasing of cordierite percentage in PUOC foam, the matrix structure was much damaged. Using Z-scan method, optical nonlinearities of samples were measured by continues wave (CW) laser at the wavelength of 532 nm. The nonlinear refractive (NLR) indices and nonlinear absorption (NLA) coefficients of the synthesized samples are obtained in the order of 10−8 (cm2/W) with negative sign and 10−5 (cm/W), respectively. The origin of optical nonlinearity may be attributed to the presence of strong saturable absorption (SA) effect

Determination of Nonlinear Optical Properties of MgO Nanoparticles Doped in Poly (Ether) Urethane

The third-order optical nonlinearities of poly (ether) urethane open cell (PEUOC)/MgO nanocomposites, dissolved in dimethylformamide are characterized by Z-scan technique with CW Nd:YAG laser at its second harmonic frequency of 532 nm with TEM00 Gaussian profile. The synthesized samples are also characterized by optical microscopy and scanning electron microscopy imaging. The nonlinear refractive indices and nonlinear absorption coefficients of the synthesized samples are obtained in the order of $10^{-8} cm^{2}//W$ with negative sign and $10^{-5} cm//W$, respectively. The origin of optical nonlinearity in this case may be attributed due to the presence of strong saturable absorption effect. All the results suggest that the nonlinear coefficients of the synthesized samples can be controlled by nanoparticles content into PEUOC. Furthermore, the results show that PEUOC/MgO may be promising candidate for the application to optical limiting in the visible region

Optical and Physical Properties of SiO2 Nanoparticles and Tetra Ortho Silicate

In this article optical and physical property of the composition of polyurethane open cell (PUOC) with two different concentrations of SiO2 nanoparticles (1 and 2wt. %) will be reported. Tetra ortho silicate (TEOS) as an organic agent with different concentrations trations (0.05, 0.1, 0.15 and 0.2 Vol./Vol.) was added to polyurethane composition. Optical microscopy imaging, watering uptake, FTIR and Raman spectroscopy of the synthesized samples were measured. The cell size of samples by adding SiO2 NPs and TEOS was decreased. The PUOC/1wt. % SiO2 was recognized as a best specimen for absorbing water. By focusing on the recorded Raman spectra, it is revealed that PUOC/1wt. % SiO2 and PUOC/200µl TEOS have more covalent bonds than others. The degree of phase separation, DPS, and the hydrogen bonding index, R, in samples were evaluated in terms of their FTIR spectroscopy data. Two samples, PUOC/1wt. % SiO2 and PUOC/800µl TEOS, have the highest R and DPS factors among the synthesized samples. By adding SiO2 NPs and TEOS into to PUOC, the apparent density of foams was increased. This is similar to the behavior of real density in SiO2 NPs into PUOC but by adding TEOS into PUOC, the real density of samples were decreased. The total porosity, open porosity and closed porosity of the synthesized samples were calculated. By adding SiO2 NPs and TEOS into PUOC, the open porosity of samples was increased

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The influence of γ-irradiation on molecular structure and mass attenuation coefficients of γ-Al2O3 nanoparticles

In this research, γ-Al2O3 nanoparticles (NPs) were synthesized by using the sol–gel process. The photon attenuation properties of these NPs were obtained by measuring the linear and mass attenuation coefficients (μl, μm) at different photon energies. In addition, the theoretical values of μm for γ-Al2O3 micro-particles were calculated using the WinXCom computer program and compared with the experimental values of μm for NPs of γ-Al2O3. Furthermore, in order to evaluate the impact of γ-irradiation on these NPs, the experimental values of μl and μm for γ-Al2O3 NPs, before and after receiving 20 kGy dose of γ-irradiation, were investigated. It was observed that μm of γ-Al2O3 NPs decreases after receiving γ-irradiation because of increasing the photon’s energy, which indicates the changes in the molecular structure of NPs after γ-irradiation. Moreover, the structural properties of NPs were evaluated by UV–Vis spectroscopy, x-ray diffraction patterns, and scanning electron microscopy images. UV–Vis spectroscopy showed an absorption peak at 212.5 nm before γ-irradiation, and the absorption peak of NPs disappeared when γ-irradiation was started. The average crystalline size was determined to be 3.65 nm in the sample before γ-irradiation and 9.29 nm in the sample with the maximum dose of 20 kGy. The results of scanning electron microscopy show an increase in particle size from 6.5 nm in a non-irradiated sample up to 9 nm in a sample with the highest γ-irradiation dose

Optical and dielectric properties of NiFe2O4 nanoparticles under different synthesized temperature

In this research, NiFe2O4 nanoparticles was prepared via the simple sol-gel route, using different sintering temperature. This nanoparticle was characterized via X-ray diffraction (XRD) pattern, scanning electron microscopy (SEM), and FTIR spectra. The XRD patterns show by increasing the synthesized temperature, the intensity, and broadening of peaks are decreased so the results are more crystallization and raising the size of nanoparticles. The size distribution in the histogram of the NiFe2O4 nanoparticles is 42, 96, and 315 nm at 750 °C, 850 °C, and 950 °C, respectively. The FTIR spectra were evaluated using Kramers-Kronig method. Results approved the existing of certain relations between sintering temperatures and grain size of nanoparticles. By raising the temperature from 750 °C to 950 °C, the grain size was increased from 70 nm to 300 nm and the optical constants of nanoparticles were strongly related to synthesizing temperature as well. Since by increasing temperature, both real/imaginary parts of the refractive index and dielectric function were decreased. Consequently, the transversal (TO) and longitudinal (LO) phonon frequencies are detected. The TO and LO frequencies have shifted to red frequencies by increasing reaction temperature. Keywords: NiFe2O4, Transversal phonon frequency, Longitudinal phonon frequency, Refractive index, Nanostructure

Structural, optical and dielectric studies of Ag nanoparticles decorated by herceptin

Silver nanoparticles (AgNPs) were synthesized (with 17�31 nm sizes) by reduction of AgNO3 by NaBH4 solution and covered by anti-HER2 monoclonal antibody (Herceptin). The morphology, structure, optical and dielectric properties of the prepared AgNPs have been characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), UV�Vis system and Fourier transform infrared (FTIR) spectroscopy. The complex index of refraction and the dielectric coefficient Herceptin and AgNPs covered by Herceptin were measured over the spectral region of 400�4000 cm�1. The XRD patterns showed the formation of face-centered cubic lattice structure of AgNPs and according to the TEM image AgNPs had spherical shape with an average diameter size of about 25 nm. By using Kramers�Kronig (KK) dispersion relations analysis, these measurements allow the determination of the real and imaginary parts of refractive index and dielectric coefficient over the entire wavelength intervals. By covering AgNPs with antibody, the intensity of n and k peaks were decreased. After decoration with AgNPs, the real and imaginary parts of permittivity in samples were also decreased. In addition, the resonance frequency of decorated samples with AgNPs have red shifts in comparison with the pure samples. These results are applicable in development of methods for detection of airborne pathogenic agent. © 2019 Elsevier B.V