Utilizing industry 4.0 on the construction site : challenges and opportunities

In recent years a step change has been seen in the rate of adoption of Industry 4.0 technologies by manufacturers and industrial organisations alike. This paper discusses the current state of the art in the adoption of industry 4.0 technologies within the construction industry. Increasing complexity in onsite construction projects coupled with the need for higher productivity is leading to increased interest in the potential use of industry 4.0 technologies. This paper discusses the relevance of the following key industry 4.0 technologies to construction: data analytics and artificial intelligence; robotics and automation; buildings information management; sensors and wearables; digital twin and industrial connectivity. Industrial connectivity is a key aspect as it ensures that all Industry 4.0 technologies are interconnected allowing the full benefits to be realized. This paper also presents a research agenda for the adoption of Industry 4.0 technologies within the construction sector; a three-phase use of intelligent assets from the point of manufacture up to after build and a four staged R&D process for the implementation of smart wearables in a digital enhanced construction site

How Do Fermions Behave on a Random Lattice?

Comparing random lattice, naive and Wilson fermions in two dimensional abelian background gauge field, we show that the doublers suppressed in the free field case are revived for random lattices in the continuum limit unless gauge interactions are implemented in a non--invariant way.Comment: updated contribution to LAT92 conference; UM-P-92/90 and OZ-92/33; 4 pages; shar archive LaTex document with figures included, requires espcrc2.sty fil

Two-phonon scattering of magnetorotons in fractional quantum Hall liquids

We study the phonon-assisted process of dissociation of a magnetoroton, in a fractional quantum Hall liquid, into an unbound pair of quasiparticles. Whilst the dissociation is forbidden to first order in the electron-phonon interaction, it can occur as a two-phonon process. Depending on the value of final separation between the quasiparticles, the dissociation is either a single event involving absorption of one phonon and emission of another phonon of similar energy, or a two-phonon diffusion of a quasiexciton in momentum space. The dependence of the magnetoroton dissociation time on the filling factor of the incompressible liquid is found.Comment: 4 pages, no figure

Mycobacterium bovis shedding patterns from experimentally infected calves and the effect of concurrent infection with bovine viral diarrhoea virus

Concurrent infection of cattle with bovine viral diarrhoea virus (BVDV) and Mycobacterium bovis is considered to be a possible risk factor for onward transmission of bovine tuberculosis (BTB) in infected cattle and is known to compromise diagnostic tests. A comparison is made here of M. bovis shedding (i.e. release) characteristics from 12 calves, six experimentally co-infected with BVDV and six infected with M. bovis alone, using simple models of bacterial replication. These statistical and mathematical models account for the intermittent or episodic nature of shedding, the dynamics of within-host bacterial proliferation and the sampling distribution from a given shedding episode. We show that while there are distinct differences among the shedding patterns of calves given the same infecting dose, there is no statistically significant difference between the two groups of calves. Such differences as there are, can be explained solely in terms of the shedding frequency, but with all calves potentially excreting the same amount of bacteria in a given shedding episode post-infection. The model can be thought of as a process of the bacteria becoming established in a number of discrete foci of colonization, rather than as a more generalized infection of the respiratory tract. In this case, the variability in the shedding patterns of the infected calves can be explained solely by differences in the number of foci established and shedding being from individual foci over time. Should maximum exposure on a particular occasion be a critical consideration for cattle-to-cattle transmission of BTB, cattle that shed only intermittently may still make an important contribution to the spread and persistence of the disease

Subduction initiation and back-arc opening north of Neo-Tethys: Evidence from the Late Cretaceous Torbat-e-Heydarieh ophiolite of NE Iran

How new subduction zones form is an ongoing scientific question with key implications for our understanding of how this process influences the behavior of the overriding plate. Here we focus on the effects of a Late Cretaceous subduction-initiation (SI) event in Iran and show how SI caused enough extension to open a back-arc basin in NE Iran. The Late Cretaceous Torbat-e-Heydarieh ophiolite (THO) is well exposed as part of the Sabzevar-Torbat-e-Heydarieh ophiolite belt. It is dominated by mantle peridotite, with a thin crustal sequence. The THO mantle sequence consists of harzburgite, clinopyroxene-harzburgite, plagioclase lherzolite, impregnated lherzolite, and dunite. Spinel in THO mantle peridotites show variable Cr# (10−63), similar to both abyssal and fore-arc peridotites. The igneous rocks (gabbros and dikes intruding mantle peridotite, pillowed and massive lavas, amphibole gabbros, plagiogranites and associated diorites, and diabase dikes) display rare earth element patterns similar to MORB, arc tholeiite and back-arc basin basalt. Zircons from six samples, including plagiogranites and dikes within mantle peridotite, yield U-Pb ages of ca. 99−92 Ma, indicating that the THO formed during the Late Cretaceous and was magmatically active for ∼7 m.y. THO igneous rocks have variable εNd(t) of +5.7 to +8.2 and εHf(t) ranging from +14.9 to +21.5; zircons have εHf(t) of +8.1 to +18.5. These isotopic compositions indicate that the THO rocks were derived from an isotopically depleted mantle source similar to that of the Indian Ocean, which was slightly affected by the recycling of subducted sediments. We conclude that the THO and other Sabzevar-Torbat-e-Heydarieh ophiolites formed in a back-arc basin well to the north of the Late Cretaceous fore-arc, now represented by the Zagros ophiolites, testifying that a broad region of Iran was affected by upper-plate extension accompanying Late Cretaceous subduction initiation

Probing semiclassical analogue gravity in Bose--Einstein condensates with widely tunable interactions

Bose-Einstein condensates (BEC) have recently been the subject of considerable study as possible analogue models of general relativity. In particular it was shown that the propagation of phase perturbations in a BEC can, under certain conditions, closely mimic the dynamics of scalar quantum fields in curved spacetimes. In two previous articles [gr-qc/0110036, gr-qc/0305061] we noted that a varying scattering length in the BEC corresponds to a varying speed of light in the ``effective metric''. Recent experiments have indeed achieved a controlled tuning of the scattering length in Rubidium 85. In this article we shall discuss the prospects for the use of this particular experimental effect to test some of the predictions of semiclassical quantum gravity, for instance, particle production in an expanding universe. We stress that these effects are generally much larger than the Hawking radiation expected from causal horizons, and so there are much better chances for their detection in the near future.Comment: 18 pages; uses revtex4. V2: Added brief discussion of "Bose-Nova" phenomenon, and appropriate reference

On the Origin of the Outgoing Black Hole Modes

The question of how to account for the outgoing black hole modes without drawing upon a transplanckian reservoir at the horizon is addressed. It is argued that the outgoing modes must arise via conversion from ingoing modes. It is further argued that the back-reaction must be included to avoid the conclusion that particle creation cannot occur in a strictly stationary background. The process of ``mode conversion" is known in plasma physics by this name and in condensed matter physics as ``Andreev reflection" or ``branch conversion". It is illustrated here in a linear Lorentz non-invariant model introduced by Unruh. The role of interactions and a physical short distance cutoff is then examined in the sonic black hole formed with Helium-II.Comment: 12 pages, plain latex, 2 figures included using psfig; Analogy to ``Andreev reflection" in superfluid systems noted, references and acknowledgment added, format changed to shorten tex

Stabilization and pumping of giant vortices in dilute Bose-Einstein condensates

Recently, it was shown that giant vortices with arbitrarily large quantum numbers can possibly be created in dilute Bose-Einstein condensates by cyclically pumping vorticity into the condensate. However, multiply quantized vortices are typically dynamically unstable in harmonically trapped nonrotated condensates, which poses a serious challenge to the vortex pump procedure. In this theoretical study, we investigate how the giant vortices can be stabilized by the application of a Gaussian potential peak along the vortex core. We find that achieving dynamical stability is feasible up to high quantum numbers. To demonstrate the efficiency of the stabilization method, we simulate the adiabatic creation of an unsplit 20-quantum vortex with the vortex pump.Comment: 8 pages, 6 figures; to be published in J. Low Temp. Phys., online publication available at http://dx.doi.org/10.1007/s10909-010-0216-

Systematics of collective correlation energies from self-consistent mean-field calculations

The collective ground-state correlations stemming from low-lying quadrupole excitations are computed microscopically. To that end, the self-consistent mean-field model is employed on the basis of the Skyrme-Hartre-Fock (SHF) functional augmented by BCS pairing. The microscopic-macroscopic mapping is achieved by quadrupole-constrained mean-field calculations which are processed further in the generator-coordinate method (GCM) at the level of the Gaussian overlap approximation (GOA). We study the correlation effects on energy, charge radii, and surface thickness for a great variety of semi-magic nuclei. A key issue is to work out the influence of variations of the SHF functional. We find that collective ground-state correlations (GSC) are robust under change of nuclear bulk properties (e.g., effective mass, symmetry energy) or of spin-orbit coupling. Some dependence on the pairing strength is observed. This, however, does not change the general conclusion that collective GSC obey a general pattern and that their magnitudes are rather independent of the actual SHF parameters.Comment: 13 pages, 13 figure

Coarse-Grained Finite-Temperature Theory for the Condensate in Optical Lattices

In this work, we derive a coarse-grained finite-temperature theory for a Bose condensate in a one-dimensional optical lattice, in addition to a confining harmonic trap potential. We start from a two-particle irreducible (2PI) effective action on the Schwinger-Keldysh closed-time contour path. In principle, this action involves all information of equilibrium and non-equilibrium properties of the condensate and noncondensate atoms. By assuming an ansatz for the variational function, i.e., the condensate order parameter in an effective action, we derive a coarse-grained effective action, which describes the dynamics on the length scale much longer than a lattice constant. Using the variational principle, coarse-grained equations of motion for the condensate variables are obtained. These equations include a dissipative term due to collisions between condensate and noncondensate atoms, as well as noncondensate mean-field. To illustrate the usefulness of our formalism, we discuss a Landau instability of the condensate in optical lattices by using the coarse-grained generalized Gross-Pitaevskii hydrodynamics. We found that the collisional damping rate due to collisions between the condensate and noncondensate atoms changes sign when the condensate velocity exceeds a renormalized sound velocity, leading to a Landau instability consistent with the Landau criterion. Our results in this work give an insight into the microscopic origin of the Landau instability.Comment: 38 pages, 2 figures. Submitted to Journal of Low Temperature Physic