We use field emission scanning electron microscope (FE-SEM) to investigate the growth of palladium colloids over the surface of thin films of WO3/glass. The film is prepared by Pulsed Laser Deposition (PLD) at different temperatures. A PdCl2 (aq) dro
plet is injected on the surface and in the presence of steam hydrogen the droplet is dried through a reduction reaction process. Two distinct aggregation regimes of palladium colloids are observed over the substrates. We argue that the change in aggregation dynamics emerges when the measured water drop Contact Angel (CA) for the WO3/glass thin films passes a certain threshold value, namely CA = 46 degrees, where a crossover in kinetic aggregation of palladium colloids occurs. Our results suggest that the mass fractal dimension of palladium aggregates follows a power-law behavior. The fractal dimension (Df) in the fast aggregation regime, where the measured CA values vary from 27 up to 46 degrees, according to different substrate deposition temperatures, is Df = 1.75 (0.02). This value of Df is in excellent agreement with kinetic aggregation of other colloidal systems in fast aggregation regime. Whereas for the slow aggregation regime, with CA = 58 degrees, the fractal dimension changes abruptly to Df=1.92 (0.03). We have also used a modified Box-Counting method to calculate fractal dimension of gray-level images and observe that the crossover at around CA = 46 degrees remains unchanged.
Logarithmic representations of the conformal Galilean algebra (CGA) and the Exotic Conformal Galilean algebra ({sc ecga}) are constructed. This can be achieved by non-decomposable representations of the scaling dimensions or the rapidity indices, spe
cific to conformal galilean algebras. Logarithmic representations of the non-exotic CGA lead to the expected constraints on scaling dimensions and rapidities and also on the logarithmic contributions in the co-variant two-point functions. On the other hand, the {sc ecga} admits several distinct situations which are distinguished by different sets of constraints and distinct scaling forms of the two-point functions. Two distinct realisations for the spatial rotations are identified as well. The first example of a reducible, but non-decomposable representation, without logarithmic terms in the two-point function is given.
We present a field theoretic model for friction, where the friction coefficient between two surfaces may be calculated based on elastic properties of the surfaces. We assume that the geometry of contact surface is not unusual. We verify Amontons laws
to hold that friction force is proportional to the normal load.This model gives the opportunity to calculate the static coefficient of friction for a few cases, and show that it is in agreement with observed values. Furthermore we show that the coefficient of static friction is independent of apparent surface area in first approximation.
Recent developments on emergence of logarithmic terms in correlators or response functions of models which exhibit dynamical symmetries analogous to conformal invariance in not necessarily relativistic systems are reviewed. The main examples of these
are logarithmic Schrodinger-invariance and logarithmic conformal Galilean invariance. Some applications of these ideas to statistical physics are described.
We show that holomorphic Parafermions exist in the eight vertex model. This is done by extending the definition from the six vertex model to the eight vertex model utilizing a parameter redefinition. These Parafermions exist on the critical plane and
integrable cases of the eight vertex model. We show that for the case of staggered eight vertex model, these Parafermions correspond to those of the Ashkin-Teller model. Furthermore, the loop representation of the eight vertex model enabled us to show a connection with the O(n) model which is in agreement with the six vertex limit found as a special case of the O(n) model.
The falling of an object through a non-Newtonian fluid is an interesting problem, depending on the details of the rheology of the fluid. In this paper we report on the settling of spherical objects through two non-Newtonian fluids: Laponite and hair
Gel. A falling objects behavior in passing through a thixotropic colloidal suspension of synthetic clay, Laponite, has been reported to have many behavioral regimes. Here we report observation of a new regime where irregular motion is observed. We argue that this irregular motion may be interpreted as onset of chaos. Observation of this regime depends on the size of the falling sphere, relaxation time of fluid and concentration of particles in the suspension. Similar experiments in Gel, a yield stress polymeric fluid, do not reveal such behavior.
We show how logarithmic terms may arise in the correlators of fields which belong to the representation of the Schrodinger-Virasoro algebra (SV) or the affine Galilean Conformal Algebra (GCA). We show that in GCA, only scaling operator can have a Jor
danian form and rapidity can not. We observe that in both algebras logarithmic dependence appears along the time direction alone.
We investigate creation of optimal entanglement in symmetric networks. The proposed network is one in which the connections are organized by a group table in other words a group association scheme. We show that optimal entanglement can be provided ov
er such networks by adjusting couplings and initial state. We find that the optimal initial state is a simple local excited state. Moreover we obtain an analytic formula for entanglement achievable between vertex pairs located in the same strata and calculate their relevant optimal couplings. For those pairs located in different strata two upper bounds are presented. These results are also checked numerically.
