Báo cáo vật lý: "Influence of the Silica-to-Surfactant Ratio and the pH of Synthesis on the Characteristics of Mesoporous SBA-15" ppt

... available in the literature.10,11 It is reported that the ratio of the silica source to the surfactant ratio and the pH of the synthesis gel can greatly influence the characteristics of the resulting ... amounts of C1– ions. Therefore, for the partial dehydration of PEO units, the volume of the hydrophilic part of the micelle decreases. This leads to an increase in the hydrophobic region or ... materials as they generally control the formation of micelles during the synthesis. 8 Hence, many aspects of the synthesis processes are involved in developing these porous materials, and they still...

... equation (5). Understanding the changes in these two constant values would lead to a better understanding of the changes in the Ea. Observation of the trend of the curve-line from the left ... traditional properties of activation energy and infinite-temperature viscosity constants, and it contains a new constant that is the zero-temperature viscosity. The ration of zero- and infinite-temperature ... equation and, together with the infinite-temperature viscosity constant, represents the fundamental value of the Ea constant. The stability of the viscosity – temperature observation is best...

Báo cáo vật lý: "The Kinetics and Mechanism of the Core-shell Styrene-butyl Acrylate Polymerisation" pdf

... polymerisation rate of the styrene core, and k is the rate reaction constant in the formation of the styrene core. 3.4 Mechanism of Reaction in the Formation of the Styrene Core The order of the ... concentration, the reaction rate becomes larger than the rate proposed by the Smith and Ewart theory.6 3.2 The Reaction Order of SLS The influence of surfactant concentration on the reaction ... Polymerisation 40 the connection equation of the number of particles or polymerisation rates as a function of surfactant and initiator concentrations.2,5,6 The other theory for emulsion polymer...

Báo cáo vật lý: "EFFECTS OF Si, Al2O3 AND SiC SUBSTRATES ON THE CHARACTERISTICS OF DBRS STRUCTURE FOR GaN BASED LASER" ppsx

... substrate. Where and are the refractive indices of the substrate and the corresponding layer respectively, is the geometrical thickness of the corresponding quarter wave layers and sn2,1n2,1dBλ ... INTRODUCTION III-V nitride semiconductors offer a wide range of applications due to their wide direct band gap, which is not found in conventional semiconductors. The current semiconductor ... covers only the region between infrared to green [1]. The band gap of GaN at room temperature is 3.4 eV (corresponding to a wavelength of 365 nm in the ultraviolet region) and that of InN,...

Báo cáo vật lý: "PREPARATION OF SELENIUM-DOPED ACTIVATED CARBON AND ITS UTILIZATION FOR IMPROVING THE QUALITY OF USED COCONUT OIL" pps

... certified solutions of known concentration of Se (500 mg/l). Standards are obtained from the National Bureau of Standards, IAEA, and commercial sources. 2.2. Materials Coconut fruits and 5% (v/v) ... 3.3 Determination of Se in MAC The following reaction of Se with neutron743426 resulted in radioactive isotope of Se. The concentration of Se in the fresh MAC was 340.3 mg/l and decreased ... the oil especially in reducing the levels Preparation of Selenium-Doped Activated Carbon 12 process that result in the generation of off-flavours that is often associated with the reduction...

Báo cáo vật lý: "EFFECT OF FIELD STRENGTH IN THE VELOCITY ANISOTROPY OF FERROFLUIDS" pptx

... al.23 concluded that at equilibrium, the magnitude of the magnetization is a function of the strength of external magnetic field, the volume concentration of the magnetic particles (their magnetic ... counteracts the orientation of the magnetic moments into the direction of the field. In a strong field, most of the particles become oriented and the magnetization of the sample attain saturated.22 ... Under the effect of an external magnetic field, the particles of the ferrofluid aggregate and chain-clusters appear to arrange along the direction of the field. The perusal of Table 2 further...

Báo cáo vật lý: "ULTRASONIC STUDY OF THE SELF–ASSOCIATION OF ANILINE IN ETHANOL-CYCLOHEXANE MIXTURES" pptx

... electrolytic solutions of copper sulphate (CuSO4.5H2O) and nickel sulphate (NiSO4.7H2O) in water. They concluded the existence of solute-solvent interactions between the components of the system. ... passage of sonic waves through the medium. Such studies as a function of concentration are useful in gaining an insight into the structure and bonding of associated molecular complexes and other ... splitting of a major component or (ii) the enlargement of existing molecules due to the added component. The contribution due to first reason will make the net inward chaos to be more and hence the...

Báo cáo vật lý: "Phase Transformation of Rust in the Presence of Various Tannins" pot

... adsorption of the tannins to the rusty surface, (ii) complexation of ferrous/ferric ions or complexation of surface iron Phase Transformation of Rust 38 Figure 6: XRD patterns of a ... lepidokrosit, magnetit Phase Transformation of Rust 32 1. INTRODUCTION The atmospheric corrosion of steel structures often results in the formation of iron oxyhydroxides such as geothites ... stabilizing action, resulting in the formation of more dense and pore free corrosion or rusted layers, may affect the protective property of tannins used.5 In addition, the composition of the rust...

Báo cáo vật lý: "The Potentiometric Analysis of Chloride Ion Using Modified Heterogeneous Chitosan Membranes" pdf

... surface. The smaller the ions the more easily they were in their mobility to the membrane surface than bulky ions. The 1.0 x 10–2 M concentration of interfering ions, B, used in these experiments ... Cl– solution | Figure 2: Illustration of ion-exchange mechanism at the surface of membrane. The mobility to and exchange of Cl– ion at cationic sites in the chitosan skeletons till equilibrium ... mechanism in the membrane. For chloride concentration 0.1 M or more, the effect of pH alteration is almost nil. Study on chitosan–Fe3+ membrane in extreme conditions, i.e. too acidic and too...

Báo cáo vật lý: "Immobilization of Dithizone onto Chitin Isolated from Prawn Seawater Shells (P. merguensis) and its Preliminary Study for the Adsorption of Cd(II) Ion" pdf

... absorption peaks of dithizone. On the other hand, although longer reaction time gives better immobilization, it seems that the active sites of the dithizone ligand bound to the surface of chitin ... for 3 h and the adsorbents were then separated from the adsorption medium. The concentration of Cd(II) ions in the solution was determined by AAS and the amount of adsorbed metal ions was calculated ... favorable condition for the metal adsorption. Further increase in pH of the solution (> 7), however, gives rise to the decrease of the adsorbed Cd(II) ion, probably due to the precipitation of Cd(II)...

Xem thêm