Distributed-memory parallelization of an explicit time-domain volume integral equation solver on Blue Gene/P

Two distributed-memory schemes for efficiently parallelizing the explicit marching-on in-time based solution of the time domain volume integral equation on the IBM Blue Gene/P platform are presented. In the first scheme, each processor stores the time history of all source fields and only the computationally dominant step of the tested field computations is distributed among processors. This scheme requires all-to-all global communications to update the time history of the source fields from the tested fields. In the second scheme, the source fields as well as all steps of the tested field computations are distributed among processors. This scheme requires sequential global communications to update the time history of the distributed source fields from the tested fields. Numerical results demonstrate that both schemes scale well on the IBM Blue Gene/P platform and the memory efficient second scheme allows for the characterization of transient wave interactions on composite structures discretized using three million spatial elements without an acceleration algorithm

Explicit Solution of the Time Domain Volume Integral Equation Using a Stable Predictor-Corrector Scheme

An explicit marching-on-in-time (MOT) scheme for solving the time domain volume integral equation is presented. The proposed method achieves its stability by employing, at each time step, a corrector scheme, which updates/corrects fields computed by the explicit predictor scheme. The proposedmethod is computationally more efficient when compared to the existing filtering techniques used for the stabilization of explicit MOT schemes. Numerical results presented in this paper demonstrate that the proposed method maintains its stability even when applied to the analysis of electromagnetic wave interactions with electrically large structures meshed using approximately half a million discretization elements

Palaeozoic-Recent geological development and uplift of the Amanos Mountains (S Turkey) in the critically located northwesternmost corner of the Arabian continent

<p>We have carried out a several-year-long study of the Amanos Mountains, on the basis of which we present new sedimentary and structural evidence, which we combine with existing data, to produce the first comprehensive synthesis in the regional geological setting. The ca. N-S-trending Amanos Mountains are located at the northwesternmost edge of the Arabian plate, near the intersection of the African and Eurasian plates. Mixed siliciclastic-carbonate sediments accumulated on the north-Gondwana margin during the Palaeozoic. Triassic rift-related sedimentation was followed by platform carbonate deposition during Jurassic-Cretaceous. Late Cretaceous was characterised by platform collapse and southward emplacement of melanges and a supra-subduction zone ophiolite. Latest Cretaceous transgressive shallow-water carbonates gave way to deeper-water deposits during Palaeocene-Eocene. Eocene southward compression, reflecting initial collision, resulted in open folding, reverse faulting and duplexing. Fluvial, lagoonal and shallow-marine carbonates accumulated during Late Oligocene(?)-Early Miocene, associated with basaltic magmatism. Intensifying collision during Mid-Miocene initiated a foreland basin that then infilled with deep-water siliciclastic gravity flows. Late Miocene-Early Pliocene compression created mountain-sized folds and thrusts, verging E in the north but SE in the south. The resulting surface uplift triggered deposition of huge alluvial outwash fans in the west. Smaller alluvial fans formed along both mountain flanks during the Pleistocene after major surface uplift ended. Pliocene-Pleistocene alluvium was tilted towards the mountain front in the west. Strike-slip/transtension along the East Anatolian Transform Fault and localised sub-horizontal Quaternary basaltic volcanism in the region reflect regional transtension during Late Pliocene-Pleistocene (<4 Ma).</p

Comparisons between Tethyan Anorthosite-bearing Ophiolites and Archean Anorthosite-bearing Layered Intrusions: Implications for Archean Geodynamic Processes

Elucidating the petrogenesis and geodynamic setting(s) of anorthosites in Archean layered intrusions and Tethyan ophiolites has significant implications for crustal evolution and growth throughout Earth history. Archean anorthosite-bearing layered intrusions occur on every continent. Tethyan ophiolites occur in Europe, Africa, and Asia. In this contribution, the field, petrographic, petrological, and geochemical characteristics of 100 Tethyan anorthosite-bearing ophiolites and 155 Archean anorthosite-bearing layered intrusions are compared. Tethyan anorthosite-bearing ophiolites range from Devonian to Paleocene in age, are variably composite, contain anorthosites with highly calcic (An44-100) plagioclase and magmatic amphibole. These ophiolites formed predominantly at convergent plate margins, with some forming in mid-ocean ridge, continental rift, and mantle plume settings. The predominantly convergent plate margin tectonic setting of Tethyan anorthosite-bearing ophiolites is indicated by negative Nb and Ti anomalies and magmatic amphibole. Archean anorthosite-bearing layered intrusions are Eoarchean to Neoarchean in age, have megacrystic anorthosites with highly calcic (An20-100) plagioclase and magmatic amphibole and are interlayered with gabbros and leucogabbros and intrude pillow basalts. These Archean layered intrusions are interpreted to have predominantly formed at convergent plate margins, with the remainder forming in mantle plume, continental rift, oceanic plateau, post-orogenic, anorogenic, mid-ocean ridge, and passive continental margin settings. These layered intrusions predominantly crystallized from hydrous Ca- and Al-rich tholeiitic magmas. The field, petrographic and geochemical similarities between Archean and Tethyan anorthosites indicate that they were produced by similar geodynamic processes mainly in suprasubduction zone settings. We suggest that Archean anorthosite-bearing layered intrusions and spatially associated greenstone belts represent dismembered subduction-related Archean ophiolites

Examination of Factors Affecting Continuance Intention to use Web-Based Distance Learning System via Structural Equation Modelling

Purpose: The present study aims to model continuance intention to use web-based distance learning system and reveal the relationship between structures. Method: In this study, factors affecting continuance intention to use a web-based distance learning system was examined with a sample of 104 students attending an initial teacher training program through a web-based distance learning system at Van Yuzuncu Yil University. The structures used in the study were identified as a result of a detailed review of literature. Moreover, complex structure of web-based distance learning systems, which included many components, were analyzed

Effect of Therapeutic Touch on Sleep Quality in Elders Living at Nursing Homes

This study was carried out to investigate the effect of therapeutic touch on sleep quality in the elderly people living in the nursing homes. The study is a randomized controlled experimental study (pretest–posttest control group). The sample of the research consisted of 25 elderly people. As a result of the study, although there was a significant increase (p 0.05). Therapeutic touch is an effective method of improving the sleep quality of the elders living at a nursing home. © 2019, Springer Science+Business Media, LLC, part of Springer Nature

An investigation of polymerflooding in limestone reservoirs with a bottom water zone

The effects of polymers on waterflooding of a limestone reservoir with or without a bottom water zone, as well as the effect of vertical and horizontal production wells on oil recovery, have been investigated in laboratory models. Sixteen core flood displacement tests were conducted to study the effect of relative oil-water layer thickness, polymer slug size, and well configuration in a production port. A qualitative comparison was made to show the difference between waterflooding and polymer-augmented waterflooding runs, where a light crude oil with a viscosity of 14.5 mPa.s was used. The results of the displacement tests showed that as the thickness of the bottom water zone increases, the ultimate oil recovery decreases. The selected polymer solution had a favorable impact on the waterflood performance. However the worse the conventional waterflood performance was, the more effective was the polymer as a mobility control agent. For instance, when the bottom water zone was approximately as thick as the oil zone, only about 25% of Original Oil in Place (OOIP) was recovered by a waterflood, whereas with a polymer as the mobility control agent, more than 55% of OOIP was recovered. For polymer injection, the effect of slug size was discussed with the aid of concentration curves and retention rate values; and a slug of 0.60 PV was obtained as optimal. In a conventional waterflood, the horizontal production well showed slightly better oil recovery than the vertical production well with a thin bottom water zone. In polymer-augmented waterflooding, higher oil recoveries were obtained with vertical production wells as compared to horizontal production wells. This was because of the early production of polymer solutions and reductions of the swept area from investigation of concentration curves