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Calcium carbonate (CaCO3) is the most widely used filler material in paper, paint, food packaging, ceramic, cosmetic, medicine, and other industries. In the present paper, synthetic calcium carbonate has been produced from waste, which is carbide lime from the acetylene gas industry which uses limestone in its production. SCC was synthesized using an advanced method called ionic sucrose solution from carbide lime. There are two variable ionic solutions which the one going through with a natural filter and retardant agent, and the other one without them to keep as a reference. The morphology shows the reference SCC that has no filter, and no additional agent was slightly coarse compared with SCC that produced by natural filter and retardant agent. Also, there was a spot on the reference SCC that has more agglomerated particles, which was attributed to the intergrowth of SCC during its formation. The XRD analysis showed that the synthesized SCC samples were pure with all peaks matching standard peak ICDD No. 00-005-0586 (synthetic calcite CaCO3.) [ABSTRACT FROM AUTHOR]

There is currently a high demand for energy that can improve our daily lives. Coal, natural gas, and nuclear energy are just a few of the resources that can be used to produce energy. These fuels do, however, also contribute significantly to environmental pollution. Therefore, considering the current situation crisis, it is necessary to investigate and utilize any available alternative or clean resources. In this study, the development of a hydrogen gas wet cell is the main goal. Using the electrolysis principle, this hydrogen or HHO gas generator separates water into its two molecules of hydrogen and oxygen, which are then released as a gas known as brown gas. It is actually an electrolysis device, with high-grade stainless steel serving as the electrodes and a mixture of water and the appropriate ionic solution KOH serving as the electrolyte. The ideal Milliliters per Minute per Watt (MMW) value was found at 16 amps, 18 seconds, and 2.5g/l KOH concentration, and it was 11.72 ml/min/W. [ABSTRACT FROM AUTHOR]

Electrokinetic effects in porous media play a key role in a number of natural and industrial processes. Applications such as enhanced oil recovery, soil remediation, and even drug delivery are influenced by the Coulomb forces generated by solid-liquid interfacial interactions. These electrokinetic effects promote the development of an inhomogeneous sliding flow over charged surfaces at the pore scale, which can have a significant effect on the hydrodynamics of dense porous materials. For the transfer of ionic solutions in such systems, a combined effect of hydrodynamic transfer and electrokinetic transfer can be expected. While pressure driven transport will be expressed in high permeability flow paths, electric field transport will be more pronounced in dense pores where the electrical diffuse layer is not negligible. To predict the growth of an oxide film, a model is used that includes both linear kinetics and classical parabolic oxidation kinetics. It is based on the quasi-stationary approximation for a thin oxide film. The local film thickness is considered a desired value, which, in particular, is explicitly included in the boundary condition for the concentration of the oxidant. Various mechanisms of flow movement were considered, for example, conventional pressure controlled flow, pure electroosmosis, as well as their superposition. Next, the effect of these different flow regimes on oxidant transfer and pore-scale oxide growth was analyzed. The numerical solution of the two-dimensional problem was obtained by the finite element method using the FEniCS computing platform. [ABSTRACT FROM AUTHOR]

The modified (G′/G2)-expansion method is an effective and reliable to construct the traveling wave solutions for nonlinear equations (NLEs). The traveling wave solutions can depict the behavior of mathematical models in several branches of sciences. This paper used the modified (G′/G2)-expansion to find new traveling wave solutions for the ionic currents along microtubules dynamical and the longitudinal wave equation in a magneto electro-elastic circular rod. The found solutions are new comparing to other solutions in the literature. [ABSTRACT FROM AUTHOR]

The interaction between the surface of the material and the ionic solution can cause many different effects on the material. One impact that might occur is material swelling. The swelling of the polymer in the form of thin films causes changes in the mechanical property of the materials. Swelling results in an expansion of the volume of the polymer. In turn, it changes molecular density, modulus of elasticity of the film, and penetration of solution to the polymer. When the polymer film is deposited on a Quartz Crystal Microbalance (QCM) sensor, the change in the mechanical affects the sensor's resonant frequency. This study shows ionic strength with an average effect of the concentration of potassium chloride on a polymer film mixed between polyvinyl chloride (PVC), polystyrene (PS), and the crown-ether (CE) associated with changes in the frequency of the coated sensor. Minimum impedance measurements show that changes in the mechanical properties of the thin film are observed. The resonant frequency of the QCM sensor decrease with time when interacting with a potassium chloride solution. While the minimum impedance at series resonance remains constant. Distilled water and KCl solution, which is varied, are used to analyze the effects of swelling that occur. The result shows that the amount of the frequency decrease depends on the concentration of the KCl solution. [ABSTRACT FROM AUTHOR]

The effects of drought stress and different ionic titanium solution soaking on the biomass and physiological and biochemical characteristics of quinoa seedlings were studied using the quinoa variety "NEGRA COLLANA". The results showed that chlorophyll content, malondialdehyde content and relative conductivity of seedling leaves increased gradually with the increase of drought stress. Leaf biomass and chlorophyll content of quinoa seedlings soaked in ionic titanium solution increased significantly, especially at 1:500 concentration. The results showed that seed soaking with ionic Titanium had a significant effect on improving plant biomass and photosynthesis. It provides a theoretical basis for revealing the drought tolerance mechanism of quinoa and the effect of ionic Titanium on yield increase. [ABSTRACT FROM AUTHOR]

For the investigation of interactions of L-leucine in aqueous solutions of an ionic liquid (1-butyl-3-methylimidazolium tetra fluoroborate [Bmim][BF4]) at atmospheric pressure over a temperature range of (293.15K to 313.16K), we use the volumetric approach. By using the density data we have calculated the apparent molar volume, VΦ, limiting apparent molar volume, V0Φ, the slope, Sv, partial molar volume of transfer, V0Φ,tr. The values of these acoustical parameters have been used for the interpretation of different interactions like hydrophilic-hydrophilic, hydrophilic-hydrophobic, ion hydrophilic, solute-solvent and solute-solute interactions in the amino acid and ionic liquid solutions. [ABSTRACT FROM AUTHOR]

The objective of the study is to synthesis as fine as possible the particle size of precipitated calcium carbonate (PCC). In previous study carbon dioxide gas was introduced into ionic solution to produce PCC. In this study ionic solution was introduced from a column into water with dissolved CO2 gas. Four experiments were carried out by flowing 1 L ionic solution (calcium sucrate) into 3 L beaker that contained water at average flow rate of 0.1 L/min. The CO2 gas was flowed into 0.5 L of water at the rate of 0.5 L/min and 1.5 L/min respectively. This was repeated using 0.6 L of water. The micrographs of Field Emission Scanning Electron Microscope (FESEM) show that fine particle size of PCC produced was 254.6 nm and cubic shapes were formed in all the products. Based on the pattern of X-ray Diffraction (XRD) results show that all PCC produced was calcite [ABSTRACT FROM AUTHOR]

For autonomous vehicles, intelligent autonomous intersection management will be required for safe and efficient operation. In order to achieve safe operation despite uncertainties in ve- hicle trajectory, intersection management techniques must consider a safety buffer around the vehicles. For truly safe operation, an extra buffer space should be added to account for the network and computational delay caused by communication with the Intersection Manager (IM). However, modeling the worst-case computation and network delay as additional buffer around the vehicle degrades the through put of the intersection. To avoid this problem, AIM[1], a popular state-of-the-art IM, adopts a query-based approach in which the vehicle requests to enter at a certain arrival time dictated by its current velocity and distance to the intersection, and the IM replies yes/no. Although this solution does not degrade the position uncertainty, it ultimately results in poor intersection throughput. We present Crossroads, a time-sensitive programming method to program the interface of a vehicle and the IM. Without requiring additional buffer to account for the effect of network and compu- tational delay, Crossroads enables efficient intersection management. Test results on a 1=10 scale model of intersection using TRAXXAS RC cars demonstrates that our Crossroads approach obviates the need for large buffers to accommodate for the network and computation delay, and can reduce the average wait time for the vehicles at a single-lane intersection by 24%. To compare Crossroads with previous approaches, we perform extensive Matlab simulations, and find that Crossroads achieves on average 1.62X higher throughput than a simple VT-IM with extra safety buffer, and 1.36X better than AIM. [ABSTRACT FROM AUTHOR]

Salt or cations, present in solution play an important role in DNA denaturation and folding kinetics of DNA helix. In this work we study the thermal melting of double stranded DNA (dsDNA) molecule using Peyrard Bishop Dauxois (PBD) model. We modify the potential of H-bonding between the bases of the complimentary strands to introduce the salt and solvent effect. We choose different DNA sequences having different contents of GC pairs and calculate the melting temperatures. The melting temperature increases logarithmically with the salt concentration of the solution. The more GC base pairs in the chain enhance the stability of DNA chain at a fix salt concentration. The obtained results are in good accordance with experimental findings. [ABSTRACT FROM AUTHOR]

The number of counterions released by oppositely charged objects, in aqueous solvents, upon their self-assembly was investigated with mean field and liquid theory approaches. We find that both Poisson-Boltzmann (PB) equation and liquid theory lead to the same amount of ion's excess in the slit of asymmetrically charged plates at small plates separation and salt concentration. The incorporation of ion's size in PB equation does not lead to important corrections on the predicted excess of ions as compared to PB equation for pointlike ions when it is applied to study the self-assembly made by cationic lipids and DNA. [ABSTRACT FROM AUTHOR]

Since the resolution of the structure of the KcsA potassium channel was published [Science 280: 69–77, 1998], there have been numerous experimental and theoretical studies looking for an explanation of the highly refined selectivity to ions of biological channels. Most numerical simulations have dealt with a complex representation of the system, but with a simple modelling of the interactions. Our group has undertaken the opposite approach, simulating simple systems with complex interactions, consisting of ionic solutions inside structureless cylinders. This approach requires proper validation by comparison to experimental data of simple systems, which can be obtained from water-filled single-wall nanotubes (SWNT). The design of analytical models for simulating nanosolutions is discussed in this work; the reliability of the models is tested by comparison to data from experiments on SWNT. The implications for the molecular mechanism of ion selectivity obtained from simulations with these models can then be assessed on a more quantitative manner. [ABSTRACT FROM AUTHOR]

Recently a general hybride quantum mechanical molecular mechanical (QM/MM) methodology named Quantum Mechanical Charge Field (QMCF) ansatz has been introduced. A variety of systems is discussed demonstrating the enhanced capabilities of this methodology. Special focus is dedicated to the point charge embedding technique accounting for the Coulombic interaction between QM and MM region and difficulties encountered in the application in a periodic environment. Examples utilising the QMCF framework in Molecular Dynamics (MD) studies demonstrate the capabilities of the method which allows the treatment of numerous composite species in solution. [ABSTRACT FROM AUTHOR]

We have measured the heat capacity and neutrion quasi- and inelastic scattering spectra of some salts of 1-butyl-3-methylimidazolium ion bmim+, which is a typical cation of room-temperature ionic liquids, and its derivatives. The heat capacity measurements revealed that the room-temperature ionic liquids have glass transitions as molecular liquids. The temperature dependence of configurational entropy demonstrated that the room-temperature ionic liquids are “fragile liquids”. Both heat capacity and inelastic neutron scattering data revealed that the glassy phases exhibit large low-energy excitations usually called “boson peak”. The quasielastic neutron scattering data showed that so-called “fast process” appears around Tg as in molecular and polymer glasses. The temperature dependence of the self-diffusion coefficient derived from the neutron scattering data indicated that the orientation of bmim+ ions and/or butyl-groups of bmim+ ions is highly disordered and very flexible in an ionic liquid phase. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]

Viscous fingering in surfactant solutions was experimentally studied. Aqueous solutions of cetyltrimethylammonium bromide (CTAB) with sodium salicylate (NaSal) as a counter ion were used as test fluids. Excess of counter ion was added into a surfactant solution of CTAB to configure network structures of wormlike micelles. The experiments were mainly carried out using a square Hele-Shaw cell. The structure of fingering pattern was dimensionally analyzed to classify the patterns into three types. In addition, growth phenomena distinguishing for the viscous finger in the CTAB/NaSal solutions were observed: surface instabilities with dendrites, and a sudden protrusion from a cuspidate shaped finger tip. The dependence of the sudden protrusion on the shear rate was confirmed by the experiment using a rectangular cell. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]

The use of N@C[sub 60] as a spin probe is demonstrated in the ionic fulleride salt Rb[sub 6]C[sub 60]. The salt contains a few ppm of N@C[sub 60] and was synthesised using a low temperature reaction. The electron spin resonance of N@C[sub 60][sup 6-] of this compound at 225 GHz (g=2 at 8.1 T) shows a small diamagnetic shift of 88±15 ppm with respect to pure N@C[sub 60]. [ABSTRACT FROM AUTHOR]

Speciation of copper in the abstraction of nano copper with a room temperature ionic liquid (RTIL) (1-butyl-3-methylimidazolium hexafluorophosphate [C4mim][PF6]) has been studied by X-ray absorption near edge structural (XANES) and extended X-ray absorption fine structural (EXAFS) spectroscopies in the present work. The least-square fits of the XANES spectra suggest that nano CuO (79%) and Cu(II) complex (Cu(II)-IL) (21%) are the main copper species in the RTIL. The fitted EXAFS spectra show that the Cu-O (1st shell) bond distance is 2.08 Å with a coordination number (CN) of 2.6. In the second shells of copper, the average bond distance of Cu-Cu is 2.99 Å with a CN of 5.1. © 2007 American Institute of Physics [ABSTRACT FROM AUTHOR]

Examines the chemical and electrochemical behavior of gallium in a low-temperature molten salt system. Properties of room temperature ionic liquid; Use of linear and cyclic voltammetry and infrared spectroscopy; Measurement of the working electrode potential change after the short-term polarization of gallium.

The electrical resistivity of compound forming liquid alloy HgPb is studied as a function of concentration. Hard sphere diameters of Hg and Pb are obtained through the inter-ionic pair potential evaluated using Troullier and Martins ab initio pseudopotential, which have been used to calculate partial structure factors. Considering the liquid alloy to be a ternary mixture Ziman's formula for calculating the resistivity of binary liquid alloys, modified for complex formation, has been used. The concentration dependence in resistivity occurs due to preferential ordering of unlike atoms as nearest neighbours with help of complex formation model. Though the compound HgiPbi as per structure peaks is found to be less stable. However it contributes significantly to resistivity as compared to bare ions. [ABSTRACT FROM AUTHOR]

Room temperature ionic liquids (RTILs) have potential throughout the nuclear industry in the recovery and purification of actinide elements, as reactor components, as waste disposal forms, and potentially as media for the storage and/or separation of spent nuclear fuels. Due to their unique dissolution properties, RTILs can be used as substitutes for solvents currently used in the extraction of uranium from native ores, and in the dissolution and reprocessing of spent nuclear fuels. Research efforts in our laboratory focus on determining the chemical properties (i.e., solubility, complexation, redox properties, etc.) of actinide species in RTIL systems. We are currently involved in RTIL projects ranging from the spectroscopic characterization of actinide complexes by O[sup 17]NMR, low temperature UV-Vis, and EXAFS, to the enhanced dissolution and separation of actinide oxides in room temperature ionic liquids. © 2000 American Institute of Physics. [ABSTRACT FROM AUTHOR]

In recent years, nanopores nave become an important tool to study the properties of single biomolecules in ionic solutions. The technique is based on the translocation of biomolecules through pores of comparable size, which are recorded as changes in the pore conductance. Among the various topics that can be studied with this technique are DNA unzipping and protein denaturation Various types of nanopores are used for these experiments, including biological, chemical, and solid-state pores. Here we present a way to fabricate sub-5-nm pores in 20–100 nm thick SiC membranes by direct drilling with a focused ion beam. In order to obtain a user-friendly setup allowing low-noise measurements, these membranes have to be carefully integrated into an electrolytic cell. For this purpose, the membranes are fixed on a piece of Pyrex containing a micrometer-sized aperture, which is used to select the desired pore and at the same time reduces the area of the membrane that is exposed to the liquid, thus reducing the capacitance and the noise of the system. [ABSTRACT FROM AUTHOR]

Room temperature ionic liquid, RTIL, [BuMIm]PF[sub6], where BuMIm[sup+] is 1-butyl-3-methyl imidazolium, has been synthesized, purified on activated carbon, and characterized by ¹H, [sup13]C NMR. Drying of [BuMIm]PF[sub6] at 80°C in 4 h on a vacuum line (P∼5 mbar) allowed the reduction of the water content to 750 ppm. Complexes [BuMIm][sub2]NpCl[sub6] and [BuMIm][sub2]PuCl[sub6], have been obtained by precipitation from Np(IV) and Pu(IV) solutions in concentrated HCl in the presence of [BuMIm]Cl. Both compounds are very soluble in [BuMIm]PF[sub6]. UV/VIS/NIR spectra of Np(IV), and Pu(IV) in [BuMIm]PF[sub6] is similar to those in aqueous concentrated HCl or 7M HCl in 75% EtOH and quite different from the spectra of Np(IV) and Pu(IV) in diluted HCl. It was assumed that octahedral hexachlocomplexes AnCl[sub6][sup2-] predominate in this RTIL. Np(IV) and Pu(IV) are slowly hydrolyzed by water in [BuMIm]PF[sub6] solutions, even being stored in a dry atmosphere. [ABSTRACT FROM AUTHOR]