Säulen griechischer Tempel unter Erdbebenbeanspruchung

Columns of Greek Temples under seismic loading: Columns of ancient Greek Temples consist of accurately dressed individual blocks in total absence on binding mortars. The seismic response of such multi‐drum structures is completely different than the corresponding one of modern continuous structures. Their stability is governed by independent sliding and rocking of drums, which creates an external energy absorption mechanism. This paper presents numerical studies on the dynamic behaviour of ancient columns which exhibits a highly non‐linear response. Alternative modeling methods are used and calibrated to experimental results. It is concluded that ancient columns may be less vulnerable to seismic events compared to modern structures. The perfection of the form unified esthetical, architectural and structural requirements.     

A novel efficient mixed formulation for strain-gradient models

Various finite elements based on mixed formulations have been proposed for the solution of boundary value problems involving strain-gradient models. The relevant literature, however, does not provide details on some important theoretical aspects of these elements. In this work, we first present the existing elements within a novel, single mathematical framework, identifying some theoretical issues common to all of them that affect their robustness and numerical efficiency. We then proceed to develop a new family of mixed elements that addresses these issues while being simpler and computationally cheaper. The behavior of the new elements is further demonstrated through two numerical examples.     

Mobility of copper in greenhouse soils

The mobility of copper (Cu) was studied in 13 soil samples from greenhouses in Falasarna, northwestern Crete, Greece. The spatial variability of Cu concentration in greenhouse soils and their physicochemical characteristics were examined. The results showed that the concentrations varied considerably, between 15 and 4900 ppb. Sorption and leaching experiments--kinetic and equilibrium--were conducted in uncontaminated and contaminated soils, respectively. Both leaching and sorption equilibrium experiments were performed as a function of pH. The leaching experiment results indicated that the total dissolved Cu concentration was between 10 and 15 ppb at a pH of 7.5, which is below the drinking water standards. The results suggest that the kinetics of Cu leaching were fast and the leachate concentration was relatively low, whereas Cu sorption kinetics were rapid and the sorbed concentrations were significant.     

Mapping the Melatonin Receptor. 8. Selective MT2 Agonists Derived from 5,6-Dihydroindolo[2,1-a]isoquinolines and Related Systems

A series of substituted indolo[2,1-a]isoquinolines and indolo[1,2-a]benzoxazines have been prepared, as melatonin analogues, to investigate the nature of the binding site of the melatonin receptor. Agonist and antagonist potency of all the analogues was measured using the [35S]GTPγS binding assay protocol. The binding affinity of the analogues were measured by competition binding studies against the human MT1 (hMT1) and MT2 (hMT2) receptors stably transfected in Chinese Hamster Ovarian (CHO) cells, using 2-[¹²⁵I]-iodomelatonin, as a ligand. N-Acetyl 2-(10-methoxy-5,6-dihydroindolo[2,1-a]isoquinolin-12-yl)propyl-1-amine (12 a) binds strongly to both the hMT1 and hMT2 receptors, and shows a preference for the hMT2, as does its propanamido counterpart 12 b . The introduction of two methyl groups into their side chain, analogues 15 a and 1 5 b , leads to antagonism, in the case of the former, and drastically diminishes its hMT1 binding; an analogous profile is seen for 15 b , which, however, is a partial agonist. Introduction of chlorine or methoxy groups into ring 4 gives compounds, that are weakly binding, with a preference for MT2. Substitution of oxygen for carbon at position 5 gives the indolo[1,2-c]benzoxazines 33 , 36 a and b , that bind strongly to the human receptors, 33 , 36 b being potent agonists at the melatonin receptors, but do not discriminate between hMT1 and hMT2.