An Innovative Technique of Liquid Purity Analysis and Its Application to Analysis of Water Concentration in Alcohol-Water Mixtures and Studies on Change of Activation Energies of the Mixtures

The activation energy of a liquid molecule and hence its viscosity coefficient changes with addition of contaminants to the original liquid. This forms the basis of a new technology for analysis of purity of the liquid. We discovered that concentration of certain contaminants such as water in alcohol or vice versa can be uniquely and accurately determined in a short time (about 10-15 minutes) using a simple and yet innovative technique that only requires measurement of time of flow of the impure liquid (say, water-alcohol mixture) and distilled water through a simple viscometer designed and constructed for this purpose. We find that the viscosity coefficient μ of alcohol increased almost linearly with water concentration at a rate that depends on the type of alcohol and water concentration. We determined the increase of activation energy of alcohol molecules with increase of water concentration. This increase also depends on type of alcohol. Our detailed investigation on alcohol-water mixtures for both ethyl and methyl alcohol along with discussion on possible future potential application of such a simple, yet very reliable inexpensive technique for liquid purity analysis is presented. A comparison is made of our present method with other methods on the accuracies, problems and reliability of impurity analysis. A part of the quantum theory of viscosity of liquid mixtures that is in the developmental stage in order to explain some of the observed properties is presented

Dependence of temperature variation of the Jahn-Teller potential well splitting and phase transition temperature in CuxZn1-xTiF6.6H2O crystals on Cu2+ ion concentration, x

The energy Eo by which one of the three Jahn-Teller potential wells becomes lower than the other two in Cu2+:ZnTiF6.6H2O single crystal at phase transition temperature, Tcl are determined at temperatures below Tcl for different Cu2+ concentrations from the electron paramagnetic resonance (EPR) spectra. As the sample is cooled, it is found that for high Cu2+ concentration, Eo increases below Tcl at a rate much slower than that for low concentration and over a much broader temperature range. With the increase of Cu2+ concentration, Tcl is found to decrease significantly. These findings appear to have a bearing on the monoclinic distortion that proceeds in this system below Tcl. Qualitative explanation of the decrease of Tcl with Cu2+ impurity concentration is presented. Eo is negligibly small for Cu2+ concentrations above certain limits means that the barrier height is also vanishing for such Cu2+ concentrations that is, phase transition of host lattice ceases. This is likely the reason for nonexistence of phase transition in some compounds like CuTiF6.6H2O and ZnSiF6.6H2O belonging to the same class with ZnTiF6.6H2O

On the order of a non-abelian representation group of a slim dense near hexagon

We show that, if the representation group $R$ of a slim dense near hexagon $S$ is non-abelian, then $R$ is of exponent 4 and $|R|=2^{\beta}$, $1+NPdim(S)\leq \beta\leq 1+dimV(S)$, where $NPdim(S)$ is the near polygon embedding dimension of $S$ and $dimV(S)$ is the dimension of the universal representation module $V(S)$ of $S$. Further, if $\beta =1+NPdim(S)$, then $R$ is an extraspecial 2-group (Theorem 1.6)

EPR STUDIES OF THE HAMILTONIAN PARAMETERS OF THE SIMULTANEOUS AXIAL AND ORTHORHOMBIC JAHN-TELLER SPECTRA OF Cu2+ IN Cd2(NH4)2(SO4)3 SINGLE CRYSTALS AT DIFFERENT TEMPERATURES

This paper presents the study of the effective Hamiltonian parameters (g1, g2, A1, A2) and the observed g and A tensors of the derivative axial and orthorhombic Jahn- Teller EPR spectra of Cu2+ in Cd2(NH4)2(SO4)3 single crystals at different temperatures. The variations of these parameters with temperature in the three mutually perpendicular planes of the crystal confirm axial symmetry for T>Tc and orthorhombic symmetry for T<Tc in this system. The simultaneous axial and anisotropic symmetries of the spectra owe their origin to the behaviour of Cu2+ ions in the three JT potential wells because they can undergo reorientation from one well to another or quantum tunnelling among them which depends on temperature, burial height or thickness and energy of the ions. The results show that the components of the activation energy and Fermi-contact parameter increase with temperature while the decrease of the anisotropy parameter (u) is more than it compensates for the slight increase in the effective Hamiltonian parameters g1 and g2 with temperature

Effect of shear force on the separation of double stranded DNA

Using the Langevin Dynamics simulation, we have studied the effects of the shear force on the rupture of short double stranded DNA at different temperatures. We show that the rupture force increases linearly with the chain length and approaches to the asymptotic value in accordance with the experiment. The qualitative nature of these curves almost remains same for different temperatures but with a shift in the force. We observe three different regimes in the extension of covalent bonds (back bone) under the shear force.Comment: 4 pages, 4 figure

Crack roughness and avalanche precursors in the random fuse model

We analyze the scaling of the crack roughness and of avalanche precursors in the two dimensional random fuse model by numerical simulations, employing large system sizes and extensive sample averaging. We find that the crack roughness exhibits anomalous scaling, as recently observed in experiments. The roughness exponents ($\zeta$, $\zeta_{loc}$) and the global width distributions are found to be universal with respect to the lattice geometry. Failure is preceded by avalanche precursors whose distribution follows a power law up to a cutoff size. While the characteristic avalanche size scales as $s_0 \sim L^D$, with a universal fractal dimension $D$, the distribution exponent $\tau$ differs slightly for triangular and diamond lattices and, in both cases, it is larger than the mean-field (fiber bundle) value $\tau=5/2$

White light tunable emissions from ZnS: Eu3+ nanophosphors over 330–465nm excitation range for white LED applications

(ZnS: Eu3+ -CMC) nanophosphors of cubic (zinc blende) structure were synthesized using a precipitation technique with doping concentrations of Eu3+ ions 1 mol% and 5 mol%. The crystal sizes were 2.56 nmand 2.91 nmrespectively. Annealing at 300 °Cin a sulfur-rich atmosphere altered the crystal size to 4.35 nmand 3.65 nmrespectively and the band gap from 4.2 eV to 3.76 eV and 3.81 eV respectively. The as-synthesized samples gave pure orange-red emission when excited at wavelengths of 394 nmand 465 nm. After thermal annealing of the samples, a broad emission band in the blue-green region assigned to defect related states emerged or were enhanced. Also enhanced were the emission lines of Eu3+ ions in the orange-red region. A combination of these two transitions gave white light of different shades (recorded on the CIE 1931 chromaticity diagram) from cool white through day-light to warm white light, depending on Eu3+ concentration and the excitation wavelengths (UV-330 to blue 465 nm), thus showing great potential of these nano-phosphors in the generation of high quality white light

The Complexity of Separating Points in the Plane

We study the following separation problem: given n connected curves and two points s and t in the plane, compute the minimum number of curves one needs to retain so that any path connecting s to t intersects some of the retained curves. We give the first polynomial (O(n3)) time algorithm for the problem, assuming that the curves have reasonable computational properties. The algorithm is based on considering the intersection graph of the curves, defining an appropriate family of closed walks in the intersection graph that satisfies the 3-path-condition, and arguing that a shortest cycle in the family gives an optimal solution. The 3-path-condition has been used mainly in topological graph theory, and thus its use here makes the connection to topology clear. We also show that the generalized version, where several input points are to be separated, is NP-hard for natural families of curves, like segments in two directions or unit circles

To freeze or not to: Quantum correlations under local decoherence

We provide necessary and sufficient conditions for freezing of quantum correlations as measured by quantum discord and quantum work deficit in the case of bipartite as well as multipartite states subjected to local noisy channels. We recognize that inhomogeneity of the magnetizations of the shared quantum states plays an important role in the freezing phenomena. We show that the frozen value of the quantum correlation and the time interval for freezing follow a complementarity relation. For states which do not exhibit "exact" freezing, but can be frozen "effectively", by having a very slow decay rate with suitable tuning of the state parameters, we introduce an index -- the freezing index -- to quantify the goodness of freezing. We find that the freezing index can be used to detect quantum phase transitions and discuss the corresponding scaling behavior.Comment: 14 pages, 9 figures, close to published version, title changed by Phys. Rev. A. to 'Freezing of quantum correlations under local decoherence