23 research outputs found
Undrained Response and Liquefaction Behaviour of Non-Plastic Silty Sands Under Cyclic Loading
The undrained response and liquefaction behaviour of fine sand and silty sands consisting of 30% and 50% non-plastic fines were investigated in the present study. The effect of consolidation stress level, cyclic stress amplitude and amount of non-plastic fines on soil liquefaction have been studied through a systematically planned stress controlled cyclic triaxial tests. To examine the effect of consolidation pressure on liquefaction behaviour, the sand-silt specimens were prepared at 40% relative density and consolidated at pressures of 50, 100 and 200 kPa. To investigate the effect of fines content on liquefaction resistance of sands at constant postconsolidation void ratio, the sand-silt specimens were prepared at different relative densities of 20, 40 and 70%. The cyclic loading with CSR in the range of 0.075 to 0.275 was applied at a frequency of 1Hz in different tests. Test results show the influence of the addition of non-plastic fines to the sand on the reduction of liquefaction resistance. Soil specimens had exhibited higher resistance to liquefaction at low consolidation pressures and lower resistance at high consolidation pressures
Crystal structure of 7,8-benzocoumarin-4-acetic acid
The fused-ring system in the title compound [systematic name: 2-(2-oxo-2H-benzo[h]chromen-4-yl)acetic acid], C15H10O4, is almost planar (r.m.s. deviation = 0.031â
Ă
) and the CarâCâC=O (ar = aromatic) torsion angle for the side chain is â134.4â
(3)°. In the crystal, molecules are linked by OâH...O hydrogen bonds, generating [100] C(8) chains, where the acceptor atom is the exocyclic O atom of the fused-ring system. The packing is consolidated by a very weak CâH...O hydrogen bond to the same acceptor atom. Together, these interactions lead to undulating (001) layers in the crystal
Observation of Associated electron Production in Annihilation
We have observed K o s production in e + e â annihilation between 3.6 and 4.4 GeV CMS energy. In the 4.0â4.1 GeV range K o s mesons occur correlated with prompt electrons, indicating the formation and weak decay of charmed particle. Within the sensitivity of the experiment, no K o s -electron correlation is seen at 3.6 and around 4.4 GeV
The total hadronic cross section for annihilation between 3.1 and 4.8 GeV center of mass energy
Search for a âtopâ threshold in hadronic annihilation at energies between 22 and 31.6
Search for narrow resonances in annihilation at petra
We have performed a search for narrow resonances in the center of mass energy range from 29.90 to 31.46 GeV using the e + e â storage ring PETRA at DESY. We present the total cross section for hadron production and an upper limit for resonance production, indicating that no bound state of charge- 2 3 quarks exists in this energy range