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Novel Environmental Friendly Fire Retardants
Get PDFNowadays flame-retardant chemicals are mandatory in many products worldwide, flame-retardant chemicals are mandatory in many products worldwide, since they protect human life and property. Over the past few decades the use of flame-retardant chemicals has increase. Flame-retardant polymeric materials have spawned huge research interest in both scientific and industrial communities due to their broad range of applications in the fields of aviation, automotive industry, construction, electronics and telecommunications. The use of conventional FRs to meet the fire safety standards is of serious importance as they ultimately yield POPs of global concern. Considering eco-friendliness and other required properties, unsatisfactory fire performance is a major obstacle. The aim of this article is to provide an overview of traditional, commonly used flame retardants, as well as an overview of new, more environmentally acceptable alternatives
Study of Structural and Optical Properties of Fe2+ Doped Tin Oxide Nanoparticles
Get PDFTin dioxide nanoparticles (SnO2) were synthesized by a sol-gel method. And tin tetra chloride (SnCl4) and ammonium hydroxide (NH4OH) were used as the precursor. NH4OH maintain the homogeneity and stoichiometry of solution through pH. The obtained powder subjected to calcination about 110oC. The obtained samples are characterized by X-ray diffraction, Scanning electron microscope, Fourier transform infrared spectroscope and UV-Visible spectroscopy. From the characterizations it is confirmed that the tetragonal structure and the particles are small and nanosizes, The O-H stretching and C=C bending stretching with chemical compositions are analyzed. The improved conduction properties through lower bandgap and the results are further interpreted and discussed
Behaviour of Nitrogen Soluble Forms in Natural Water in the Presence of Anionic and Cationic Surfactants and Mineral Substrates
Get PDFThe redox processes, organic substances accumulation, chemical equilibria and adsorption of organic substances on the substrate surface function of natural water compositions and substrate granule sizes have been investigated. Laboratory simulations have been carried out for the Nistru and Isnovat river waters. The natural water models containing laurylsulphate (LS) as anionic surfactant (SAS An) and cetyltrimethylammonium (CTMA) as cationic surfactant (SAS Ct), separately and in a body, as well as the substrates Al(OH)3, Al2O3, CaCO3, H2SiO3, light fraction (clayey) of diatomite and expanded clay powder have been studied. The timely distribution of the soluble nitrogen species containing NH4+, NO2- and NO3- in the samples of natural waters has been analyzed. It has been found that LS diminishes the redox processes braking due to the partial fixation of toxic organic matter. Similar, but more pronounced enhancement impact on oxidation of nitrite ions as a result of fixation and sedimentation of organic components has been found in the case of the calcium carbonate powder. Also, CaCO3 produces a better SAS Ct separation/inactivation of organic part in the presence of both anionic and cationic SASs. A water self-purification processes effectiveness in polluted river waters decreases in the CaCO3, Al(OH)3, Al2O3, H2SiO3, light fraction (clayey) of diatomite, expanded clay powder substrate series
Investigating the Rheological Properties of Ultra High Strength Concrete Made with Various Superplasticizers
Get PDFUltra-High Strength Concrete (UHSC) is a high-strength and highly ductile material formulated to provide compressive strengths exceeding 130MPa. UHSC materials typically have a very low water-to-cementitious ratio (w/cm), which requires the use of superplasticizers to disperse the fine particles and to make the material workable for placing, handling and consolidating. Common examples of superplasticizer compositions include Polynaphthalene Sulfonate (PNS), Polymelamine Sulfonate (PMS) and Polycarboxylate Ether (PCE) based polymers. This study focuses on assessing the impact of various superplasticizers on the compressive strength and rheological performance of a UHSC mixture. Four different types of superplasticizers were used; two different PCE based superplasticizers from a leading manufacturer, one PNS superplasticizer, and one PCE superplasticizer, both of which were provided by a local chemical provider. Specific properties assessed were the superplasticizers' viscosity, concrete workability through the mortar-spread test, concrete rheology, and 7, 14, and 28 day compressive strengths. Two mixtures were produced with two w/cm (0.20 and 0.15), which would subsequently increase the amount of HRWRA needed, from 34.7L/m3 to 44.5L/m3. The results show that both name brand PCE superplasticizers produce a higher spread, lower viscosity, and a higher compressive strength at all ages tested up to 28 days than the two local superplasticizers. Additionally, the rheology test demonstrated that the name brand PCE superplasticizers, and UHSC produced with such superplasticizers, had a lower viscosity at all angular speeds than the local superplasticizers counterparts
Slope Stability Analysis of "Vorobyovy Gory" Landslide in Moscow
Get PDF There are many engineering-geological problems in Moscow, including seepage deformation, karst and landslide. Among them, landslides develop along the Moscow River and its branches. This paper aims to analyze the slope stability of "Vorobyovy Gory" landslide with the help of the program GeoStudio. According to the limit equilibrium method, we can know the slope stability. In addition, we can know the internal friction angle among in the physical and mechanical parameters of soil layer has the greatest influences on its stability by sensitivity analysis. Finally, we can get the probability of damage by probabilistic analysis
Determination of the Sufficient Inductance of AC Line Reactor at the Input of Frequency Converter
Get PDF This article discusses the problem of sufficient inductance of AC line reactor at the input of frequency converter. Author provided some simulations for frequency converter loaded by induction motors with different rated powers. For all induction motors the following characteristics of phase current consumed by frequency converter from the grid considered. Instantaneous peak current during the frequency acceleration of induction motor. Amplitude of the current in steady state mode after the end of induction motor acceleration. Instantaneous peak current during additional charge of DC-link capacitance through the shunting contact of charging resistance. Instantaneous peak current when charging DC-link capacitance through the charging resistance - the most stable characteristic, which is practically does not depend on the presence and nominal of the line reactor. It is advisable to demand to inductance of the line reactor, that is, to percent impedance or short-circuit voltage, %, that the considered in computational experiments peak and amplitude values of currents remain not higher than the last above mentioned. It can be stated that with the increase of induction motor rated power, the sufficient value of short-circuit voltage, %, also increases. 
PIXE Investigation of Ancient Linen Fabrics Dated from Old Kingdom to Ptolemaic Ages (2200-300 B.C.)
Get PDFExternal milli-beam particle induced X-ray emission spectroscopy (PIXE) has been used as non-destructive technique to investigate ancient linen fabrics from pre-dynastic and Ptolemaic ages belonging to the archaeological collections of the Egyptian Museum of Turin and to the Civic Archaeological Museum of Bologna, Italy. 9 linen fabric samples dated from Old Kingdom to Ptolemaic ages (2200-300 B.C.) were investigated, as well as 5 modern linen fabric samples, added for comparison. The primary goal of this work has been to advance the correct material description of the fabrics providing scientific data for further and more comprehensive comparative analyses. PIXE has provided quantitative analyses for the major (Si, Cl, K, Ca and Fe) and minor or trace elements as P, Ti and Mn, supplying information on the near-surface elemental composition. The achieved results contribute to comprehend the structural basis for the chemical properties of the considered materials, as well as to set up a classification according to the chemical composition, allowing in general a better understanding of the studied linen cloths
Optimized Extraction of Dietary Fiber from Defatted Rice Bran and Evaluation of the Fiber-fortified Drink Yogurt
Get PDFThe effects of time, temperature and concentration of hydrogen peroxide on the extraction yield of fiber from defatted rice bran, its color, water binding and oil binding capacity were investigated using the central composition design with three variables. Carboxymethyl cellulose (CMC) and extracted fiber were added to drink yogurt in different ratios (0-0, as blank sample, 0-0.05, 0-0.1, 0-0.2, 0.5-0.05 and 1-0.05) and rheological properties of the drink were analyzed weekly for 21 days. The results showed that temperature and hydrogen peroxide concentration significantly affected fiber extraction yield, and hydrogen peroxide concentration had the greatest impact on L*. The process temperature had the greatest impact on oil binding capacity of the fiber. However, water binding capacity was not affected by any parameter. Rheological tests indicated that blank sample was a Newtonian fluid while the drink yogurt fortified with the fiber showed a pseudo-plastic behavior
Introduction of Local Spatial Constraints and Local Similarity Estimation in Possibilistic c-Means Algorithm for Remotely Sensed Imagery
Get PDFThis paper presents a unique Possibilistic c-Means with constraints (PCM-S) with Adaptive Possibilistic Local Information c-Means (ADPLICM) in a supervised way by incorporating local information through local spatial constraints and local similarity measures in Possibilistic c-Means Algorithm. PCM-S with ADPLICM overcome the limitations of the known Possibilistic c-Means (PCM) and Possibilistic c-Means with constraints (PCM-S) algorithms. The major contribution of proposed algorithm to ensure the noise resistance in the presence of random salt & pepper noise. The effectiveness of proposed algorithm has been analysed on random “salt and pepper” noise added on original dataset and Root Mean Square Error (RMSE) has been calculated between original dataset and noisy dataset. It has been observed that PCM-S with ADPLICM is effective in minimizing noise during supervised classification by introducing local convolution
A Datamining Based Decision Support System For Fruit Manufacturing
Get PDFAgricultural activities provide one of the main sources of living in many regions of the world. Such products play significant roles for the survival of living organisms. Farmers all around the world work towards reaching their economic goals through agricultural activities. By doing this, they invest both their capital and time. In some occasions, such investments end up with serious losses and planted products either grow in low levels or do not grow at all. In this study, in order to avoid such situations and guide the investors intelligently, a decision support system based on decision tree is developed. Related parameters in accordance with the climatic and geographic characteristics of the region are determined within this proposed system. Then, appropriate types of fruits are proposed to the users as the outcome of the system based on these parameters. By doing this, producing more efficient and profitable products is aimed