Symmetry and Z_2-Orbifolding Approach in Five-dimensional Lattice Gauge Theory

In a lattice gauge-Higgs unification scenario using a Z_2-orbifolded extra-dimension, we find a new global symmetry in a case of SU(2) bulk gauge symmetry. It is a global symmetry on sites in a fixed point with respect to Z_2-orbifolding, independent of the bulk gauge symmetry. It is shown that the vacuum expectation value of a Z_2-projected Polyakov loop is a good order parameter of the new symmetry. The effective theory on lattice is also discussed.Comment: 13 pages, 3 figures; refined the explanation

Enamel Structure in Odontocete Whales

With regard to the enamel structure of mammals, a large number of studies have been reported in the past. Of them, however, the enamel structure of odontocetes has not yet been sufficiently elucidated. The author therefore observed the enamel structure of 11 species in 7 families of living odontocetes. A clear prism structure in the enamel is noted in delphinids and Pontoporia blainvillei. Neophocaena phocaenoides has a very simple-structured prism, but even this structure is obvious only in the deep layer of the enamel, disappearing gradually from the mid layer to surface layer. The prism pattern of delphinids differs significantly depending on the site of the enamel; that of Pontoporia shows as a whole pattern 1. On the other hand, the enamel of Physeter catodon, Berardius bairdi, Phocoena phocoena, Phocoenoides dalli and Delphmapterus leucus is prismless. The enamel of Physeter and Phocoena shows pseudo-prisms; that of Phocoenoides contains enamel tubuli. The enamel of Berardms and Delphinapterus is 3 to 8 μm thick, which is extremely thin for mammalian enamel. No enamel was noted in Monodon monoceros teeth. The enamel structure of living odontocetes is thus very variable. Several characteristic structures having been present during the evolutionary course of this tissue are still present in some of them. As the results of comparative histologic study, it is considered that the variable enamel structure of liv-ing odontocetes is a secondary phenomenon produced during the degenerative history of the enamel

THE EFFECT OF FOULING ON HEAT TRANSFER, PRESSURE DROP AND THROUGHPUT IN REFINERY PREHEAT TRAINS: OPTIMISATION OF CLEANING SCHEDULES

Optimising cleaning schedules for refinery preheat trains requires a robust and reliable simulator, reliable fouling models and the ability to handle the thermal and hydraulic impacts of fouling. The interaction between thermal and hydraulic effects is explored using engineering analyses and fouling rate laws based on the ‘threshold fouling’ concept; the potential occurrence of a new phenomenon, ‘thermo-hydraulic channeling’ in parallel heat exchangers, is identified. The importance of the foulant thermal conductivity is highlighted. We also report the development of a highly flexible preheat train simulator constructed in MATLAB&#;/Excel&#;. It is able to accommodate variable throughput, control valve operation and different cost scenarios. The simulator is demonstrated on a network of 14 heat exchangers, where the importance of optimising the flow split between parallel streams is illustrated