Macroscopic Order Research Articles

AKTIVITAS ANTIBAKTERI EKSTRAK ISOLAT FUNGI ENDOFIT DARI AKAR MANGROVE (Rhizophora apiculata Blume) SECARA KLT BIOAUTOGRAFI

Endophytic fungi have the ability to produce bioactive compounds one of which is antibacterial. A search of bioactive compounds in this research are the first was isolated endophytic fungi on the roots of mangrove then be purified and macroscopic order to obtain pure 6 isolates endophytic fungi. Proceed with the screening test to test bacteria and endophytic fungal isolates obtained first by IJM 2 code which provides activity against 5 test bacteria with the formation of the largest inhibition zone diameter. Then proceed with the fermentation of isolates IJM 2 for 21 days at room temperature using Potato Dextrose Broth medium after the separation to obtain a supernatant and mycelia. Then proceed with the solvent extraction using ethyl acetate and the extract obtained extract supernatant and mycelia. The extract obtained is then followed by TLC-Bioautografi testing using the eluent n-butanol: acetic acid: water (8: 1: 2). Results chromatogram profile with KLT-Bioutografi method showed antibacterial activity against bacteria Shigella dysentriae , Pseudomonas aeruginosa , Salmonella thypii , Vibrio cholerae , Stahpylococcus aureus .

AKTIVITAS ANTIBAKTERI EKSTRAK ISOLAT FUNGI ENDOFIT DARI AKAR MANGROVE (Rhizophora apiculata Blume) SECARA KLT BIOAUTOGRAFI

Endophytic fungi have the ability to produce bioactive compounds one of which is antibacterial. A search of bioactive compounds in this research are the first was isolated endophytic fungi on the roots of mangrove then be purified and macroscopic order to obtain pure 6 isolates endophytic fungi. Proceed with the screening test to test bacteria and endophytic fungal isolates obtained first by IJM 2 code which provides activity against 5 test bacteria with the formation of the largest inhibition zone diameter. Then proceed with the fermentation of isolates IJM 2 for 21 days at room temperature using Potato Dextrose Broth medium after the separation to obtain a supernatant and mycelia. Then proceed with the solvent extraction using ethyl acetate and the extract obtained extract supernatant and mycelia. The extract obtained is then followed by TLC-Bioautografi testing using the eluent n-butanol: acetic acid: water (8: 1: 2). Results chromatogram profile with KLT-Bioutografi method showed antibacterial activity against bacteria Shigella dysentriae , Pseudomonas aeruginosa , Salmonella thypii , Vibrio cholerae , Stahpylococcus aureus .

Fragmented-condensate solid of dipolar excitons

We discuss a possible link between the recently observed macroscopic ordering of ultra cold dipolar excitons (MOES) and the phenomenon of supersolidity. In the dilute limit we predict a stable supersolid state for a quasi-one-dimensional system of bosonic dipoles characterized by two- and three-body contact repulsion. We phenomenologically extend our theory to the strongly-correlated regime and find a critical value of the contact interaction parameter at which the supersolid exhibits a quantum phase transition to a fragmented state. The wavelength of the fragmented-condensate solid is defined by the balance between the quantum pressure and the entropy due to fluctuations of the relative phases between the fragments. Our model appears to be in good agreement with the relevant experimental data, including the very recent results on commensurability effect and wavelength of the MOES.

Macroscopically constrained Wang-Landau method for systems with multiple order parameters and its application to drawing complex phase diagrams.

A generalized approach to Wang-Landau simulations, macroscopically constrained Wang-Landau, is proposed to simulate the density of states of a system with multiple macroscopic order parameters. The method breaks a multidimensional random-walk process in phase space into many separate, one-dimensional random-walk processes in well-defined subspaces. Each of these random walks is constrained to a different set of values of the macroscopic order parameters. When the multivariable density of states is obtained for one set of values of fieldlike model parameters, the density of states for any other values of these parameters can be obtained by a simple transformation of the total system energy. All thermodynamic quantities of the system can then be rapidly calculated at any point in the phase diagram. We demonstrate how to use the multivariable density of states to draw the phase diagram, as well as order-parameter probability distributions at specific phase points, for a model spin-crossover material: an antiferromagnetic Ising model with ferromagnetic long-range interactions. The fieldlike parameters in this model are an effective magnetic field and the strength of the long-range interaction.

Cluster multipole theory for anomalous Hall effect in antiferromagnets

We introduce a cluster extension of multipole moments to discuss the anomalous Hall effect (AHE) in both ferromagnetic (FM) and antiferromagnetic (AFM) states in a unified framework. We first derive general symmetry requirements for the AHE in the presence or absence of the spin-orbit coupling, by considering the symmetry of the Berry curvature in k space. The cluster multipole (CMP) moments are then defined to quantify the macroscopic magnetization in non-collinear AFM states, as a natural generalization of the magnetization in FM states. We identify the macroscopic CMP order which induces the AHE. The theoretical framework is applied to the non-collinear AFM states of Mn3Ir, for which an AHE was predicted in a first-principles calculation, and Mn3Z (Z=Sn, Ge), for which a large AHE was recently discovered experimentally. We further compare the AHE in Mn3Z and bcc Fe in terms of the CMP. We show that the AHE in Mn3Z is characterized with the magnetization of a cluster octupole moment in the same manner as that in bcc Fe characterized with the magnetization of the dipole moment.

Design of Macroscopically Ordered Liquid Crystalline Hydrogel Columns Knitted with Nanosilver for Topical Applications.

The design of liquid crystalline hydrogels knitted with silver nanoparticles in macroscopic ordering is becoming a subject of research interest due to their promising multifunctional applications in biomedical and optoelectronic applications. The present work describes the development of liquid crystalline Schiff-based hydrogel decorated with silver nanoparticles and the demonstration of its antifungal applications. Schiff base was prepared from polyglucanaldehyde and chitosan, and the former was prepared by the oxidation of amylose (polyglucopyranose) isolated from abundantly available unutilized jackfruit seed starch. Self-assembled silver columns decorated with macroscopically ordered networks were prepared in a single step of in situ condensation and a reduction/complexation process. The various noncovalent interactions among the -OH, -C═O, and -NH impart rigidity and ordering for the formation of macroscopically ordered liquid crystalline hydrogel and the Ag(I) complexation evidenced from the studies made by FT-IR spectroscopy in combination with rheology and microscopic techniques such as SEM, TEM, AFM, XRD, and PLM. The antifungal studies were screened using species of Candida by disc diffusion method. The MIC and MFC values, in vitro antifungal studies, reactive oxygen species (ROS) production, and propidium iodide (PI) uptake results suggest that the present macroscopically ordered liquid crystalline hydrogel system can be considered an excellent candidate for topical applications. All these results suggest that this design strategy can be exploited for the incorporation of biologically relevant metal nanoparticles for developing unique robust hydrogels for multifunctional applications.

Effect of ZnO twin grain boundary on Zn vacancies induced d0 ferromagnetism: First‐principles calculations

First‐principles calculation, based on density functional theory, is applied to study the electronic and magnetic properties of Zn vacancies in ZnO Σ7 (120) twin grain boundary with fivefold coordination sites. The fivefold coordination can facilitate the formation and aggregation of Zn vacancies. The O atoms around Zn vacancies are responsible for the ferromagnetic state, which has an obvious character of d0 ferromagnetism. Meanwhile, the twin grain boundaries have a two‐dimensional periodic structure, and periodical fivefold coordination sites are available, which favors the realization of the macroscopic ferromagnetic ordering. The result also gives us a new thinking to understand d0 ferromagnetism in undoped ZnO.

Dynamically Controlled Iridescence of Cholesteric Cellulose Nanocrystal Suspensions Using Electric Fields.

Cellulose nanocrystal suspensions in apolar solvent spontaneously form iridescent liquid-crystalline phases but the control of their macroscopic order is usually poor. The use of electric fields can provide control on the cholesteric orientation and its periodicity, allowing macroscopic sample homogeneity and dynamical tuning of their iridescent hues, and is demonstrated here.

Topological thermal Hall effect in frustrated kagome antiferromagnets

In frustrated magnets the Dzyaloshinsky-Moriya interaction arising from spin-orbit coupling can induce a magnetic long-range order. Here, we report a theoretical prediction of thermal Hall effect in frustrated kagom\'e magnets such as KCr$_3$(OH)$_6$(SO4)$_2$ and KFe$_3$(OH)$_{6}$(SO$_{4}$)$_2$. The thermal Hall effects in these materials are induced by scalar spin chirality as opposed to DMI in previous studies. The scalar spin chirality originates from magnetic-field-induced chiral spin configuration due to non-coplanar spin textures, but in general it can be spontaneously developed as a macroscopic order parameter in chiral quantum spin liquids. Therefore, we infer that there is a possibility of thermal Hall effect in frustrated kagom\'e magnets such as herbertsmithite ZnCu$_3$(OH)$_6$Cl$_2$ and the chromium compound Ca$_{10}$Cr$_7$O$_{28}$, although they also show evidence of magnetic order in the presence of a magnetic field or pressure.

Evolution of the domain structure of triglycine sulphate single crystal in the vicinity of phase transition

ABSTRACTThe temporal behavior of the domain structure of triglycine sulphate single crystal (TGS) was studied by means of atomic force microscopy near the phase transition temperature: 321 K ≤ T <TC = 322 K. It is shown that the total number of domains and their total linear dimensions along two selected directions decrease exponentially in time. The average linear dimensions of domains along nearly [001] and [100] directions obey to the law: <w> ∼ tϕ. The exponent ϕ varies from 0,45 to 0,93. These values indicate to the non-conservative nature of macroscopic order parameter characterizing the domain structure of TGS in the temperature interval under study. A character of time dependence of the average velocity of lateral movement (nearly along [001]) of the domain walls changes qualitatively when removing from the phase transition temperature.

Hierarchy of universal entanglement in 2D measurement-based quantum computation

AbstractMeasurement-based quantum computation (MQC) is a paradigm for studying quantum computation using many-body entanglement and single-qubit measurements. Although MQC has inspired wide-ranging discoveries throughout quantum information, our understanding of the general principles underlying MQC seems to be biased by its historical reliance upon the archetypal 2D cluster state. Here we utilise recent advances in the subject of symmetry-protected topological order (SPTO) to introduce a novel MQC resource state, whose physical and computational behaviour differs fundamentally from that of the cluster state. We show that, in sharp contrast to the cluster state, our state enables universal quantum computation using only measurements of single-qubit Pauli X, Y, and Z operators. This novel computational feature is related to the ‘genuine’ 2D SPTO possessed by our state, and which is absent in the cluster state. Our concrete connection between the latent computational complexity of many-body systems and macroscopic quantum orders may find applications in quantum many-body simulation for benchmarking classically intractable complexity.

Temperature dependence of angular momentum transport across interfaces

Angular momentum transport in magnetic multilayered structures plays a central role in spintronic physics and devices. The angular momentum currents or spin currents are carried by either quasi-particles such as electrons and magnons, or by macroscopic order parameters such as local magnetization of ferromagnets. Based on the generic interface exchange interaction, we develop a microscopic theory that describes interfacial spin conductance for various interfaces among non-magnetic metals, ferromagnetic and antiferromagnetic insulators. Spin conductance and its temperature dependence are obtained for different spin batteries including spin pumping, temperature gradient and spin Hall effect. As an application of our theory, we calculate the spin current in a trilayer made of a ferromagnetic insulator, an antiferromagnetic insulator and a non-magnetic heavy metal. The calculated results on the temperature dependence of spin conductance quantitatively agree with the existing experiments.

Non-extensive statistical analysis of magnetic field during the March 2012 ICME event using a multi-spacecraft approach

Abstract In this study we present some new and significant results concerning the dynamics of interplanetary coronal mass ejections (ICMEs) observed in the near Earth at L1 solar wind environment, as well as its effect in Earth’s magnetosphere. The results are referred to Tsallis non-extensive statistics and in particular to the estimation of Tsallis q -triplet, ( q s t a t , q s e n , q r e l ) of magnetic field time series of the ICME observed at the Earth resulting from the solar eruptive activity on March 7, 2012 at the Sun. For this, we used a multi-spacecraft approach based on data experiments from ACE, CLUSTER 4, THEMIS-E and THEMIS-C spacecraft. For the data analysis different time periods were considered, sorted as “quiet”, “shock” and “aftershock”, while different space domains such as the Interplanetary space (near Earth at L1 and upstream of the Earth’s bowshock), the Earth’s magnetosheath and magnetotail, were also taken into account. Our results reveal significant differences in statistical and dynamical features, indicating important variations of the magnetic field dynamics both in time and space domains during the shock event, in terms of rate of entropy production, relaxation dynamics and non-equilibrium meta-stable stationary states. So far, Tsallis non-extensive statistical theory and Tsallis extension of the Boltzmann–Gibbs entropy principle to the q -entropy principle (Tsallis, 1988, 2009) reveal strong universality character concerning non-equilibrium dynamics (Pavlos et al. 2012a,b, 2014a,b; Karakatsanis et al. 2013). Tsallis q -entropy principle can explain the emergence of a series of new and significant physical characteristics in distributed systems as well as in space plasmas. Such characteristics are: non-Gaussian statistics and anomalous diffusion processes, strange and fractional dynamics, multifractal, percolating and intermittent turbulence structures, multiscale and long spatio-temporal correlations, fractional acceleration and Non-Equilibrium Stationary States (NESS) or non-equilibrium self-organization process and non-equilibrium phase transition and topological phase transition processes according to Zelenyi and Milovanov (2004). In this direction, our results reveal clearly strong self-organization and development of macroscopic ordering of plasma system related to strengthen of non-extensivity, multifractality and intermittency everywhere in the space plasmas region during the CME event.

Spontaneous piezoelectric effect as order parameter in (NH4)2CuBr4·2H2O crystal

Temperature change of piezoelectric properties of (NH4)2CuBr4·2H2O crystal in the low-temperature ferroelastoelectric phase is studied. The macroscopic order parameter is proved to be the h36 component of the spontaneous piezoelectric tensor. The critical exponent related with the phase transition is α=0.60±0.05.

The inherent dynamics of isotropic- and nematic-phase liquid crystals.

The geodesic (shortest) pathways through the potential energy landscape of a liquid can be thought of as defining what its dynamics would be if thermal noise were removed, revealing what we have called the "inherent dynamics" of the liquid. We show how these inherent paths can be located for a model liquid crystal former, showing, in the process, how the molecular mechanisms of translation and reorientation compare in the isotropic and nematic phases of these systems. These mechanisms turn out to favor the preservation of local orientational order even under macroscopically isotropic conditions (a finding consistent with the experimental observation of pseudonematic domains in these cases), but disfavor the maintenance of macroscopic orientational order, even in the nematic phase. While the most efficient nematic pathways that maintain nematic order are indeed shorter than those that do not, it is apparently difficult for the system to locate these paths, suggesting that molecular motion in liquid-crystal formers is dynamically frustrated, and reinforcing the sense that there are strong analogies between liquid crystals and supercooled liquids.

Molecular field theory for polar, biaxial bent-core nematics

ABSTRACTWe have studied a polar, biaxial nematic liquid crystal formed from bent-core molecules using molecular field theory. The model includes a simple Heisenberg-form dipolar intermolecular interaction in addition to the usual quadrupolar nematic interaction, and mimics a system consisting of nematogenic bent-core molecules with a large transverse dipole along the bisector of the two molecular arms. Such systems are regarded as good candidates for biaxial nematic liquid crystals. In principle, the molecular dipoles can align, thus stabilising the ordering of the minor axes. Our calculations predict that, for suitable values of the bent-core interarm angle, the biaxial nematic phase can be stabilised at higher temperatures than in the absence of the transverse dipole. In general, the transverse macroscopic polar order stabilises the biaxial nematic phase. In particular, for a large enough dipolar interaction, the Landau point in the pure biaxial nematic develops into a line of first-order polar biaxial nematic-to-isotropic phase transitions.

Exciton Delocalization in H2OBPc1–xMOBPcx (M = Co, Cu, Ni, Mn) Crystalline Thin-Film Organic Alloys

Novel solution-processing deposition techniques in tandem with chemical synthesis design of small-molecule soluble derivatives represent a viable avenue for exploring organic analogues of semiconductor alloyed systems, where excitonic properties are tunable through alloy concentration. Here these properties are explored using absorption, grazing incidence X-ray diffraction (GIXRD), and temperature-dependent/time-resolved photoluminescence spectroscopy (TRPL) in a series of crystalline thin film alloys of metal-free (H2OBPc) and metal (MOBPc) octabutoxy-phthalocyanine, H2OBPc1–xMOBPcx (M = Co, Cu, Ni, or Mn) where 0.5 ≥ x ≥ 0.001. Films are fabricated using a solution-processed, novel hollow pen-writing technique that results in millimeter-sized crystalline grains with long-range macroscopic order for all concentrations. The spectroscopy experiments produce two important results that offer great insight into the fundamental quantum mechanics of delocalized excitons in small-molecule semiconductors. First, ...

Interface and Confinement Induced Order and Orientation in Thin Films of Poly(ϵ-caprolactone)

Infrared transition moment orientational analysis (IR-TMOA), X-ray diffraction (XRD), and model calculations are combined to study interface and confinement induced order and orientation in thin (h ≈ 11 μm) films of poly(ϵ-caprolactone) (PCL), as prepared by drop-casting on silicon wafers. Depending on the crystallization temperature, 303 K ≤ Tx ≤ 333 K, nonbanded spherulites with a diameter of 1 μm ≤ dS ≤ 500 μm form. Macroscopic order of the crystalline lamellae is imposed by interfacial layers and geometrical confinements of the spherulitc structures (dS > h): radial crystal growth is restricted to a disc of aspect ratio dS/h. Order is quantified by IR-TMOA and XRD pole figure measurements, which both rely on the relative orientation of the sample and the incident radiation and measure, in the case of PCL, the orientation distribution of complementary crystal directions. This enables one to (1) correlate the directions of the transition moments with the crystal axes and (2) estimate the volume fraction...

Photoinduced and Thermal Relaxation in Surface-Grafted Azobenzene-Based Monolayers: A Molecular Dynamics Simulation Study.

Extensive atomistic molecular dynamics simulations have been employed to study the structure and molecular orientational relaxation of azobenzene-based monolayers grafted to a solid substrate. Systems with surface coverage of 0.6 nm(2)/molecule were investigated over a wide temperature range ranging from 298 K, where the mesogens show local ordering and the monolayer dynamics was found to be glassy, up to 700 K, where the azobenzene groups have a nearly isotropic orientational distribution, with a subnanosecond characteristic orientational relaxation time scale. Biased simulations that model single-molecule thermal excitation and conformational isomerization have been conducted to obtain insight into the mechanisms for photoinduced athermal fluidization and monolayer reorganization observed experimentally in this system. Our simulations clearly indicate that trans-cis conformational isomerization transitions of azobenzene units can lead to reorientation of mesogens and to the formation of a monolayer with strong macroscopic in-plane nematic order. While local heating created by excitation process can facilitate this process, thermal excitation alone is not sufficient to induce ordering in the monolayer. Instead, the work done by a molecule undergoing cis-trans isomerization on the cage of neighboring molecules is the key mechanism for photofluidization and orientational ordering in dMR monolayers exposed to linearly polarized light leading to relaxation dynamics that can be described in terms of higher effective temperature. The obtained simulation results are discussed in light of recent experimental data reported for these systems.

Chiral-Linkage-Induced Hierarchical Ordering of Colloidal Achiral Nanotubes in their Thixotropic Gel.

Macroscopic continuous hierarchical ordering of achiral nanotube "imogolite" was achieved by thixotropic gelation of imogolite with chiral hydroxy acid and their flow-orienting/subsequent standing for uniaxial alignments of imogolite. The chirality change of the hydroxy acids resulted in an inversion of the helical ordering. The study presented here first exhibits the millimeter-scale supramolecular chirality induced by angstrom-scale molecular handedness in the architecture of nanotubes.