Stoichiometry and Stability Constant Values for Copper (II) Chelates with Ethylene Diamine in Deep Eutectic Solvents (DES) (Ethaline) Solutions

In this study we used the deep eutectic solvents (ionic liquids) to investigate the reaction between copper (II) with ethylene diamine (en). Two of the existing methods for analyzing spectrophotometric measurements have been applied for establishing, the stoichiometry and whenever possible, the stability constants of the chelates formed. The method of continuous variations was necessary to determine first whether, the metal ion and the ligand ethylene diamine form one or more than one chelate, when more than one chelate formed, the results obtained depend on the wavelength and for meaningful conclusions the wavelengths were carefully selected. The empirical formulae of the chelates were further substantiated by the molar ratio method. The effect of time and temperature on the formation and stability of these chelates in solution is also studied. The stability constants, K1 and K2 for the copper (II) chelates were calculated, though reliable, and are comparable to literature values.

Effect of Carrier Liquid on Electrorheological Performance and Stability of Oxalate Group-modified TiO2 Suspensions

By using oxalate group-modified TiO2 nanoparticles as the dispersing phase, different kinds of silicone oil with various viscosities and terminal groups（hydroxyl, hydrogen, and methyl） were used as the dispersing media to prepare different electrorheological（ER） fluids. Their zero-field viscosity, yield stress under direct current electric fields, ER efficiency, shear stability, leakage current density, and sedimentation stability were tested to study the effect of carrier liquid on the properties of ER fluids. The results indicate that the zerofield viscosity, the yield stress, and the leakage current density increase with increasing viscosity of the silicone oils. The effects of the viscosity on the ER efficiency, the shear stability, and the sedimentation ratio depend on the competition between the viscous resistance and the aggregation of the particles. Among the three ER fluids prepared with silicone oil with different terminal groups, hydroxyl-terminated oil based sample has the highest zero-field viscosity, the highest field-induced yield stress and ER efficiency, the largest current density, and the best sedimentation stability.

MHD Stability Analysis and Flow Controls of Liquid Metal Free Surface Film Flows as Fusion Reactor PFCs

Numerical and experimental investigation results on the magnetohydrodynamics（MHD） film flows along flat and curved bottom surfaces are summarized in this study. A simplified modeling has been developed to study the liquid metal MHD film state, which has been validated by the existing experimental results. Numerical results on how the inlet velocity（V）, the chute width（W） and the inlet film thickness（d0） affect the MHD film flow state are obtained. MHD stability analysis results are also provided in this study. The results show that strong magnetic fields make the stable V decrease several times compared to the case with no magnetic field,especially small radial magnetic fields（Bn） will have a significant impact on the MHD film flow state. Based on the above numerical and MHD stability analysis results flow control methods are proposed for flat and curved MHD film flows. For curved film flow we firstly proposed a new multi-layers MHD film flow system with a solid metal mesh to get the stable MHD film flows along the curved bottom surface. Experiments on flat and curved MHD film flows are also carried out and some firstly observed results are achieved.

Stability of liquid crystal systems doped withγ-Fe_(2)O_(3)nanoparticles

In order to explore the stability of a liquid crystal(LC)system doped withγ-Fe_(2)O_(3)nanoparticles,the physical properties(clearing point,dielectric properties),electro-optical properties and residual direct-current voltage(RDCV)of the doped LC system were measured and evaluated at different times.First,the temperature was controlled by precision hot stage,and the clearing point temperature of doped LC was observed and measured by a polarized optical microscope.Using a precision LCR meter,we measured the capacitance-voltage curves of the doped LC system at the temperature of 27℃.The dielectric constant of doped LC was calculated by the dualcell capacitance method.Then,the electro-optical properties of the doped LC system were measured.Finally,the RDCV of the doped LC system was measured and calculated.After five months,the parameters of the doped LC system were re-measured and analyzed under the same conditions to evaluate its stability.The experimental results show that,within five months,the clearing point change rate of doped LC is in the range of 0.24%-1.37%,the change of dielectric anisotropy is in the range of 0.035-0.2,the curves of electro-optical properties are basically fitted,and the change rate of saturated RDCV is about 11.2%,which basically indicate that the LC system doped withγ-Fe_(2)O_(3)nanoparticles has good stability.

Stability analysis of liquid filled spacecraft system with flexible attachment by using the energy–Casimir method

The stability of partly liquid filled spacecraft with flexible attachment was investigated in this paper. Liquid sloshing dynamics was simplified as the spring-mass model, and flexible attachment was modeled as the linear shearing beam. The dynamic equations and Hamiltonian of the coupled spacecraft system were given by analyzing the rigid body, liquid fuel, and flexible appendage. Nonlinear stability conditions of the coupled spacecraft system were derived by computing the variation of Casimir function which was added to the Hamiltonian. The stable region of the parameter space was given and validated by numerical computation. Related results suggest that the change of inertia matrix, the length of flexible attachment, spacecraft spinning rate, and filled ratio of liquid fuel tank have strong influence on the stability of the spacecraft system.

Experimental research on breakup of 2D power law liquid film

On account of limited knowledge of the breakup of power law liquid film, the process of its disintegration and atomization was studied by using a planar liquid film. A linear stability analysis was adopted to predict the breakup characteristics of the power law film. The predicting formulas of stripping breakup length and diameter of ligament were put forward presently. Through high-speed photography and laser light sheet illumination,different breakup characteristics of flat power law film under different conditions were derived. The characteristic dimension of breakup regimes were defined and extracted. The effects of several parameters(injection pressure,ambient pressure, nozzle structure and fluid property) on the stripping breakup length and spray angle were investigated. The results revealed that increasing both the velocity of liquid film and the ambient pressure facilitated the breakup of film, reduced the stripping breakup length and enlarged the spray angle in different extents. The comparison between theoretical and experimental results was conducted to validate the feasibility of the linear stability theory.

A selective reflecting film with a temperature-dependent pitch length

A(polymer network/liquid crystal/chiral dopants) composite exhibiting a temperature-sensing switch of infrared spectrum has been developed.Because of the different change of the chiral dopant in the helical twisting power and the anchoring effect of the polymer network,the polymer stabilized liquid crystal(PSLC) films,of which the bandwidth of the selective reflection spectra increased with changing temperature,were obtained.

Solid state synthesis of nano-mineral particles

Many researchers in academia and industries are interested in reducing particle sizes from few submicrometers to nano-meter levels.These nano-particles find application in several areas including ceramics,paints,cosmetics,microelectronics,sensors,textiles and biomedical,etc.This article reviews the present state of the art for solid state synthesis of mineral nano-particles by wet milling,including their operating variables such as ball size,solid mass fraction and suspension stability.This article concludes and recommends with a critical discussion of nano-particles synthesis and a few common strategies to overcome stability issues.

Improved suspension quality and liquid level stability in stirred tanks with Rotor-Stator agitator based on CFD simulation

The solid-liquid mixing is an important operation unit in the preparation of composites by stirring casting.High quality composite materials need good homogeneity and stable liquid level.In this work,the performances of the Rotor-Stator agitator for solid suspension in stirred tank were investigated through CFD modeling,including the homogeneity,power consumption and liquid level stability.The Eulerian-Eulerian(E-E)multiphase model and the RNG k-εturbulence model were adopted for modeling the multiphase flow and the turbulence effects,respectively.The effect of various important parameters such as stirring speed,particle size,solid loading and the use of baffles were examined.Adding a stator structure with array holes outside the rotor can optimize the flow pattern,thereby improving the mixing uniformity and liquid level stability.The homogeneity and liquid level stability attained by the Rotor-Stator agitator were better than those for the A200(an axial-flow agitator)and the Rushton(a radial-flow agitator).

Multiple-SO3H functioned ionic liquid as efficient curing agent for phthalonitrile-terminated poly(phthalazinone ether nitrile)

Combined with the advantages of low melting point,high thermal stability and strong acidity,a multipleSO_3H functioned ionic liquid（MIL） was developed successfully as a curing agent to promote the curing reaction of phthalonitrile-terminated poly（phthalazinone ether nitrile）（PPEN-Ph）.The curing kinetics over differential scanning calorimetry（DSC） showed that both the initial curing temperature Tp0＇ and apparent activation energy Ea＇（based on Kissinger equation） were reduced significantly over MIL（207.9℃ and 101.5 kJ/mol） compared to the common curing agent ZnCl_2（268.5℃ and 201.5 kJ/mol）.Moreover,under identical curing conditions,the resulting thermosetting resin over former（Td5%=526.1℃） showed better thermal stability than that over latter（Td5%=512.1 ℃）.These results indicated that MIL should be a good candidate as a curing agent for phthalonitrile resins.

Charge distribution into illuminated dye-doped surface stabilized ferroelectric liquid crystal cell

Surface stabilized （anti） ferroelectric liquid crystal cells can be used as an optically addressed media for optical data processing. The structure of the cell has to contain a photo sensible agent, i.e, an absorbing dye-doped orienting layer. The all-optical generation of the diffractive grating can be done due to the switching parameters of the smectic slab within cells with a sensitive layer. This Letter considers a study of the optically induced charge generation into the dye-doped layer, and the explanation of the phenomena of the selective molecular director reorientation, while cell driving what leads to the induction of phase grating.

Comparison of short-term and long-term performances for polymer-stabilized sand and clay

A series of tests were carried out on sulfate rich, high-plasticity clay and poorly-graded natural sand to study the effectiveness of a methylene diphenyl diisocyanate based liquid polymer soil stabilizer in improving the unconfined compressive strength （UCS） of freshly stabilized soils and aged sand specimens. The aged specimens were prepared by exposing the specimens to ultraviolet radiation, freeze-thaw, and wet-dry weathering. The polymer soil stabilizer also mitigated the swelling of the expansive clay. For clay, the observations indicated that the sequence of adding water and liquid polymer had great influence on the gained UGS of stabilized specimens. However, this was shown to be of little importance for sand. Furthermore, sand samples showed incremental gains in UCS when they were submerged in water. This increase was significant for up to 4 days of soaking in water after 4 days of ambient air curing. Conversely, the clay samples lost a large fraction of their UCS when soaked in water; however, their remaining strength was still considerable. The stabilized specimens showed acceptable endurance under weathering action, although sample yellowing due to ultraviolet radiation was evident on the surface of the specimens. Except for moisture susceptibility of the clay specimens, the results of this study suggested the liquid stabilizer could be successfully utilized to provide acceptable strength, durability and mitigated swelling.

Local heat transfer properties in co- and counter-current G-L-S magnetically stabilized fluidized beds

Heat transfer coefficients were measured by immersed probes in co- and counter-current G-L-S magnetically stabilized fluidized beds （MSFBs） using air, water and nickel-alloy particles as the gas, liquid and solid phases. Influences of major factors, including magnetic field intensity, superficial gas and liquid velocities, liquid viscosity and surface tension, on heat-transfer properties were studied experimentally, indicating that both co- and counter-current G-L-S MSFB can provide relatively uniform radial distribution of heat transfer coefficients under appropriate operation conditions, thus controlling operation temperature for highly exothermic multi-phase reaction systems. Two correlations were provided to estimate accurately heat transfer properties in both co- and counter-current G-L-S MSFB systems, with an average error of less than 10%.