The Temple of Zeus at Lebadea. The architecture and the semantics of a colossus

The Temple of Zeus Basileus at Lebadea rests almost unknown. Its physical remains and date (not systematically explored so far) pose a riddle, as regards not only the circumstances which entailed its presumed incompletion but also the historic context in which the commencement of construction can be embedded. The dimensions of the krepis alone render this edifice highly interesting in the history of temple-building. The in situ preserved architectural elements suggest that here was begun the erection of what was at the time the largest peristasis in Mainland Greece. The temple stylobate measures 200 feet/podes in length, with a lower column diameter equal to just over two metres, and the longest interaxial spacings and corresponding architraves of its time. By increasing the length and height of the structure, the architects achieved its qualification as colossal. This qualification is revealed from the uniquefor-the-Classical-period length of 14 columns along the peristasis, with visible euthynteria and hypeuthynteria courses. As shown in this paper, this colossal structure abided by the rules of Doric design. Ascribing the unfinished state of the temple probably to financial shortcoming and/or military adventures, Pausanias did comment on its ambitious, gigantic size. The level of construction eventually reached is another focal point of our investigation. The study of the Temple of Zeus Basileus brings out the multifaceted notion of the term “monumentality”, tightly related to visual impact. One of the aims of its commissioners would have been to establish a landmark on the summit where Zeus was probably co-worshipped with Trophonios, the Boeotian hero-prophet. Since the temple in question, as we propose, most probably commemorated both a grandiose military victory in the 3rd century BC and the contemporary political situation, its imposing volume, along with the aesthetic effect of bichromy, were meant to perpetuate the overtone of these events within the ambience of the sacred Lebadea. Another facet of monumentality involves the respective building programme, and it derives from epigraphical sources, namely a contract specifying construction details, with particular instructions already at the orthostate level, denoting that accuracy in execution safeguarded the high quality of ancient Greek architecture.

Pair lines of sight observations of multiphase gas bearing O vi in a galaxy environment

ABSTRACT Using HST/COS spectra of the twin quasar lines of sight Q 0107–025A & Q 0107–025B, we report on the physical properties, chemical abundances, and transverse sizes of a multiphase medium in a galaxy field at z = 0.399. The angular separation between the quasars corresponds to a physical separation of 520 kpc at the absorber redshift. The absorber towards Q 0107–025B is a partial Lyman limit system (pLLS) with $\log N({\mathrm{H}}{\small I})/\hbox{cm$^{-2}$}\approx 16.8$. The H i column density in the absorber along the other sightline is ≈ 2 orders of magnitude lower. The O vi along both sightlines have comparable column densities and broad b-values (b > 30 km s−1) whereas the low ionization lines are considerably narrower. The low ionization gas is inconsistent with the O vi when modelled assuming photoionization from the same phase. In both lines of sight, O vi and the broad H i coinciding, are best explained through collisional ionization in a cooling plasma with solar metallicity. Ionization models infer 1/10th solar metallicity for the pLLS and solar metallicity for the lower column density absorber along the other sightline. Within ± 250 km s−1 and 2 Mpc of projected distance from the sightlines 12 galaxies are identified, of which five are within 500 kpc. The twin sightlines are at normalized impact parameters of ρ ∼ 1.1Rvir, and ρ ∼ 0.8Rvir from a M* ∼ 1010.7 M⊙, L ∼ 0.07L*, and star formation rate (SFR) < 0.1 M⊙ yr−1 galaxy, potentially probing its CGM (circumgalactic medium). The next closest in normalized separation are a dwarf galaxy with M* ∼ 108.7 M⊙, and SFR ∼ 0.06 M⊙ yr−1, and an intermediate mass galaxy with M* ∼ 1010.0 M⊙, and SFR ∼ 3 M⊙ yr−1. Along both sightlines, O vi could be either tracing narrow transition temperature zones at the interface of low ionization gas and the hot halo of nearest galaxy, or a more spread-out warm component that could be gas bound to the circumgalactic halo or the intragroup medium. The latter scenarios lead to a warm gas mass limit of M ≳ 4.5 × 109 M⊙.

Elucidating the global distribution of reprocessing gas in NGC 1194

ABSTRACT A joint XMM–Newton and NuSTAR observation was conducted for the bright, local Seyfert 1.9 galaxy, NGC 1194. The hard spectral form of this active galactic nucleus (AGN) was modelled using the toroidal reprocessor mytorus. The decoupled model form provides a good description of the spectrum, with reflection arising from gas with a global average column density >4 × 1024 cm−2 and transmission of the continuum through an order-of-magnitude lower column. In this model, the reflection strength is a factor of ∼3 higher than expected from a simple torus. Such a result may indicate that much of the intrinsic X-ray continuum is hidden from view. An alternative model is that of a patchy torus, where 85 per cent of sightlines are obscured by Compton-thick gas and the remaining 15 per cent by Compton-thin gas. The patchy torus model is based on a solar abundance of Fe and is consistent with X-ray partial-covering results found in other AGN. That a patchy torus model would relieve the issue with the strength of the reflection signature is not an intuitive result: such an insight regarding the geometry of the global reprocessing gas could not have been obtained using ad hoc model components to describe the spectral form.

The Role of Sediment-induced Light Attenuation on Primary Production during Hurricane Gustav (2008)

We introduce a sediment-induced light attenuation algorithm into the biogeochemical model of the Regional Ocean Modeling System (ROMS). A fully coupled ocean-atmospheric-sediment-biogeochemical simulation is carried out to assess the impact of sediment-induced light attenuation on primary production in the northern Gulf of Mexico during Hurricane Gustav in 2008. The new model shows a better agreement with satellite data on both the magnitude of nearshore chlorophyll concentration and the distribution of offshore bloom. When Gustav approaches, resuspended sediments shift the inner shelf ecosystem from a nutrient-limited one to light-limited. One week after Gustav’s landfall, accumulated nutrient and favorable optical environment induces a post-hurricane algal bloom in the top 20 m of water column, while the productivity in the lower column is still light-limited due to unsettled sediment. Corresponding with the elevated offshore NO3 flux (38.71 mmol N/m/s) and decreased chlorophyll flux (43.10 mg/m/s), the post-hurricane bloom in the outer shelf is resulted from the cross-shelf nutrient supply instead of the lateral dispersed chlorophyll. Sensitivity tests indicate sediment light attenuation efficiency affects primary production when sediment concentration is moderately high.

Abrupt transitions in an atmospheric single-column model with weak temperature gradient approximation

We document a feature of the tropical atmosphere that could be relevant to episodes of abrupt transitions in global climate that regularly occurred during the last ice age. Using a single-column model incorporating the weak temperature gradient (WTG) approximation, we find that abrupt transitions occur as the sea surface temperature is steadily increased. Because these transitions arise from the interplay of scales between local deep convection and the large-scale adjustments that are required to maintain weak temperature and pressure gradients, they are only present with the WTG approximation relevant for the tropics but may be of interest as a trigger for abrupt transitions in global climate. These transitions are marked by an abrupt change in the partitioning of rainfall between convective and large-scale (microphysics) subroutines, in addition to various other features of the column including cloudiness, vertical velocity, temperature, and humidity. We conclude that the transitions are initiated by a failure of evaporative cooling in the lower free troposphere. This leads to lower-column heating and a burst of convection that heats the upper free troposphere, increasing the large-scale rainfall rate and re-stabilizing the lower-column evaporative cooling.

Seismic performance evaluation of reinforced concrete beam-column joints of existing buildings

Common computer programs generally model beam-column joint (BCJ) as a finite point without physical property that will neither yield nor fail. However, this assumption is not appropriate for modelling existing buildings without seismic provisions where the shear capacities of BCJs were uncertain. This paper presented the finite element analysis and cyclic load test results of four full-scale edge column BCJ specimens with and without column and BCJ shear link detailing according to seismic provisions. The aim was to compare the numerical analysis and experimental results to establish a reduction factor between BCJ with and without seismic detailing provisions and to verify the accuracy of numerical analysis results. With the proposed reduction factor, non-seismic provisioned BCJ that will fail under seismic actions can be determined from general computer analysis programs and correspondingly strengthened if necessary to ensure that yielding occurs in structural members connected to the joint instead of brittle joint shear failure. Furthermore, splitting crack along the lower column axis was observed in all non-seismic provisioned specimens due to eccentricity between the upper and lower column load centre and inadequate link confinement in the lower column.

Confronting Vitruvius: a geometric framework and design methodology for Roman rectangular temples

Studies of design principles of Roman temples typically have been based on Vitruvius, which inspired a belief that the colonnade was at the core of the geometric framework of every temple and that the lower column diameter (D) was used as a module to plan all other aspects, both horizontally and vertically. Archaeological evidence, however, shows that most extant temples do not match the Vitruvian model.1 Scholars have tried to explain the discrepancies in different ways: for example, by claiming that Vitruvius did not describe the actual state of Roman architecture but “what it should be”,2 that architects had to make “adjustments” to the “Vitruvian ideal” to create a particular effect, or that they had to make on-site corrections.3 A few studies have shown that also other design principles must have been at play. P. Barresi, based on the geometric analyses of several temple-podia of the 5th to 1st c. B.C. in central Italy, argued that they were designed and built relative to a square grid.4 He derived the size of each grid-module from the proportions of the rectangles of the temples' bases. He later reached the same conclusion for the temples of the Capitolium at Sufetula,5 while J.-N. Bonneville presented a similar theory for temples at Baelo Claudia.6 M. Wilson Jones observed that the principal parts of the façades of the Temple of Portunus at Rome and the Maison Carrée at Nîmes formed square contours,7 which he considered a reason for the “irregularities” (relative to Vitruvian principles) in the intercolumniations. He also presented other examples of simple geometric shapes in the compositions of the façades of Roman buildings.

The abundance and physical properties of O vii and O viii X-ray absorption systems in the EAGLE simulations

We use the EAGLE cosmological, hydrodynamical simulations to predict the column density and equivalent width distributions of intergalactic O vii ($E=574 \, \rm {eV}$) and O viii ($E=654 \, \rm {eV}$) absorbers at low redshift. These two ions are predicted to account for $40 \, \hbox{ per cent}$ of the gas-phase oxygen, which implies that they are key tracers of cosmic metals. We find that their column density distributions evolve little at observable column densities from redshift 1 to 0, and that they are sensitive to active galactic nucleus feedback, which strongly reduces the number of strong (column density $N \gtrsim 10^{16} \, \rm {cm}^{-2}$) absorbers. The distributions have a break at $N \sim 10^{16}\, \rm {cm}^{-2}$, corresponding to overdensities of ∼102, likely caused by the transition from sheet/filament to halo gas. Absorption systems with $N \gtrsim 10^{16} \, \rm {cm}^{-2}$ are dominated by collisionally ionized O vii and O viii, while the ionization state of oxygen at lower column densities is also influenced by photoionization. At these high column densities, O vii and O viii arising in the same structures probe systematically different gas temperatures, meaning their line ratio does not translate into a simple estimate of temperature. While O vii and O viii column densities and covering fractions correlate poorly with the H i column density at ${N}_{\rm {H}\, \rm {I}} \gtrsim 10^{15} \, \rm {cm}^{-2}$, O vii and O viii column densities are higher in this regime than at the more common, lower H i column densities. The column densities of O vi and especially Ne viii, which have strong absorption lines in the UV, are good predictors of the strengths of O vii and O viii absorption and can hence aid in the detection of the X-ray lines.

Comparing monolithic and fused core HPLC columns for fast chromatographic analysis of fat-soluble vitamins

HPLC stationary phases of monolithic and fused core type can be used to achieve fast chromatographic separation as an alternative to UPLC. In this study, monolithic and fused core stationary phases are compared for fast separation of four fat-soluble vitamins. Three new methods on the first and second generation monolithic silica RP-18e columns and a fused core pentafluoro-phenyl propyl column were developed. Application of three fused core columns offered comparable separations of retinyl palmitate, DL-α-tocopheryl acetate, cholecalciferol and menadione in terms of elution speed and separation efficiency. Separation was achieved in approx. 5 min with good resolution (Rs> 5) and precision (RSD ≤ 0.6 %). Monolithic columns showed, however, a higher number of theoretical plates, better precision and lower column backpressure than the fused core column. The three developed methods were successfully applied to separate and quantitate fat-soluble vitamins in commercial products.

Comparison of Hybrid Four-Dimensional Data Assimilation Methods with and without the Tangent Linear and Adjoint Models for Predicting the Life Cycle of Hurricane Karl (2010)

Two four-dimensional hybrid data assimilation systems based on the Weather Research and Forecasting (WRF) Model are applied over the life cycle of Hurricane Karl (2010). One method uses a mix of ensemble- and climate-based background error covariance in a four-dimensional variational data assimilation (4DVar) system that uses an adjoint model to assimilate observations over a time window (denoted E4DVar). The second method approximates the function of linearized models in 4DVar with perturbations generated from an ensemble forecast using the full nonlinear model (denoted 4DEnVar). Ensemble perturbations in 4DEnVar provide a four-dimensional covariance, which is combined with a static climate-based covariance for performing the data assimilation. In cycling data assimilation experiments, analyses produced by both methods provide more accurate intensity forecasts than E3DVar, owing mostly to a better representation of moisture near the developing storm. Despite providing a computationally efficient alternative to E4DVar, predictions made from 4DEnVar analyses are less accurate than E4DVar for the tested case study. Numerical experiments using identical background error statistics in both schemes reveal differences in the mesoscale structure of the developing storm, which are suspected to be responsible for this result. In particular, 4DEnVar analyses contain a less intense inner-core circulation and lower column relative humidity than E4DVar at analysis times closest to Karl’s genesis, which lead to a persistent slow bias in intensifying the storm. These results suggest errors introduced in the linearization of the model for E4DVar may be less severe than errors introduced by the localization of time covariances. This study provides the first comparison of hybrid E4DVar and 4DEnVar for a tropical cyclone application.