Phase diagram of J1-J2 transverse field Ising model on the checkerboard lattice: a plaquette-operator approach

We study the effect of quantum fluctuations by means of a transverse magnetic field ($\Gamma$) on the antiferromagnetic $J_1-J_2$ Ising model on the checkerboard lattice, the two dimensional version of the pyrochlore lattice. The zero-temperature phase diagram of the model has been obtained by employing a plaquette operator approach (POA). The plaquette operator formalism bosonizes the model, in which a single boson is associated to each eigenstate of a plaquette and the inter-plaquette interactions define an effective Hamiltonian. The excitations of a plaquette would represent an-harmonic fluctuations of the model, which lead not only to lower the excitation energy compared with a single-spin flip but also to lift the extensive degeneracy in favor of a plaquette ordered solid (RPS) state, which breaks lattice translational symmetry, in addition to a unique collinear phase for $J_2>J_1$. The bosonic excitation gap vanishes at the critical points to the N\'{e}el ($J_2 < J_1$) and collinear ($J_2 > J_1$) ordered phases, which defines the critical phase boundaries. At the homogeneous coupling ($J_2=J_1$) and its close neighborhood, the (canted) RPS state, established from an-harmonic fluctuations, lasts for low fields, $\Gamma/J_1\lesssim 0.3$, which is followed by a transition to the quantum paramagnet (polarized) phase at high fields. The transition from RPS state to the N\'{e}el phase is either a deconfined quantum phase transition or a first order one, however a continuous transition occurs between RPS and collinear phases.Comment: To appear in EPJB, 12 pages, 15 figures, 1 tabl

Consistency of Kaluza-Klein Sphere Reductions of Symmetric Potentials

In a recent paper, the complete (non-linear) Kaluza-Klein Ansatz for theconsistent embedding of certain scalar plus gravity subsectors of gaugedmaximal supergravity in D=4, 5 and 7 was presented, in terms of spherereductions from D=11 or type IIB supergravity. The scalar fields included inthe truncations were the diagonal fields in the SL(N,R)/SO(N) scalarsubmanifolds of the full scalar sectors of the corresponding maximalsupergravities, with N=8, 6 and 5. The embeddings were used for obtaining aninterpretation of extremal D=4, 5 or 7 AdS domain walls in terms of distributedM-branes or D-branes in the higher dimensions. Although strong supportingevidence for the correctness of the embedding Ansatze was presented, a fullproof of the consistency was not given. Here, we complete the proof, by showingexplicitly that the full set of higher-dimensional equations of motion aresatisfied if and only if the lower-dimensional fields satisfy the relevantscalar plus gravity equations

S3S^{3} and S4S^{4} Reductions of Type IIA Supergravity

We construct a consistent reduction of type IIA supergravity on S^3, leading to a maximal gauged supergravity in seven dimensions with the full set of massless SO(4) Yang-Mills fields. We do this by starting with the known S^4 reduction of eleven-dimensional supergravity, and showing that it is possible to take a singular limit of the resulting standard SO(5)-gauged maximal supergravity in seven dimensions, whose eleven-dimensional interpretation involves taking a limit where the internal 4-sphere degenerates to RxS^3. This allows us to reinterpret the limiting SO(4)-gauged theory in seven dimensions as the S^3 reduction of type IIA supergravity. We also obtain the consistent S^4 reduction of type IIA supergravity, which gives an SO(5)-gauged maximal supergravity in D=6

Cellular immune response of infectious bursal disease and Newcastle disease vaccinations in broilers exposed to monochromatic lights

To investigate the effects of various monochromatic lights on T lymphocytes proliferation and serum nitric oxide production in chicken vaccinated with infectious bursal disease and newcastle disease vaccines, a total of 60 one-day-old broilers were exposed to red, green, blue, white and yellow light by using a light-emitting diode system for 6 weeks. The results indicated that the proliferation of peripheral blood T lymphocytes in the chickens exposed to white and green lights significantly increased when compared with other groups at 37 days of age (P &lt; 0.05). In the early days, the results were different. The enhancement of T lymphocytes proliferation with green and yellow lights occurred at 18 days, whereas the enhancement with green light was less than other lights at 30 days. Red light promoted NO (nitrix oxide) production at maximum level in the chickens, while green light suppressed it at minimum level after 37 days. These results suggested that green and white lights had strong effects on immunity, especially at the last days of rearing.Key words: Monochromatic lights, vaccination, nitric oxide, broiler chicken

Consistent SO(6) Reduction Of Type IIB Supergravity on S^5

Type IIB supergravity can be consistently truncated to the metric and the self-dual 5-form. We obtain the complete non-linear Kaluza-Klein S^5 reduction Ansatz for this theory, giving rise to gravity coupled to the fifteen Yang-Mills gauge fields of SO(6) and the twenty scalars of the coset SL(6,R)/SO(6). This provides a consistent embedding of this subsector of N=8, D=5 gauged supergravity in type IIB in D=10. We demonstrate that the self-duality of the 5-form plays a crucial role in the consistency of the reduction. We also discuss certain necessary conditions for a theory of gravity and an antisymmetric tensor in an arbitrary dimension D to admit a consistent sphere reduction, keeping all the massless fields. We find that it is only possible for D=11, with a 4-form field, and D=10, with a 5-form. Furthermore, in D=11 the full bosonic structure of eleven-dimensional supergravity is required, while in D=10 the 5-form must be self-dual. It is remarkable that just from the consistency requirement alone one would discover D=11 and type IIB supergravities, and that D=11 is an upper bound on the dimension.Comment: Latex, 14 pages, typos corrected and comments adde

Toward Sustainable Tackling of Biofouling Implications and Improved Performance of TFC FO Membranes Modified by Ag-MOF Nanorods

In this work, nanorods with high antibacterial properties were synthesized with silver acetate as the metal source and 2-aminoterephthalic acid as the organic linker and were then embedded into thin-film composite (TFC) membranes to amend their performance as well as to alleviate biofouling. Silver metal-organic framework (Ag-MOF) nanorods with a length smaller than 40 nm were incorporated within the polyamide thin selective layer of the membranes during interfacial polymerization. The interaction of the synthesized nanorods with the polyamide was favored because of the presence of amine-containing functional groups on the nanorod's surface. The results of X-ray photoelectron spectroscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and atomic force microscopy characterizations proved the presence of Ag-MOF nanorods in the selective layer of thin-film nanocomposite (TFN) membranes. TFN membranes demonstrated improved water permeance, salt selectivity, and superior antibacterial properties. Specifically, the increased hydrophilicity and antibacterial potential of the TFN membranes led to a synergetic effect toward biofouling mitigation. The number of live bacteria attached to the surface of the neat TFC membrane decreased by more than 92% when a low amount of Ag-MOF nanorods (0.2 wt %) was applied. Following contact of the TFN membrane surface with Escherichia coli and Staphylococcus aureus, full inactivation, and degradation of bacteria cells were observed with microscopy, colony-forming unit tests, and disc inhibition zone analyses. This result translated to a negligible amount of the biofilm formed on the active layer. Indeed, the incorporation of Ag-MOF nanorods decreased the metal-ion release rate and therefore provided prolonged antibacterial performance