Seismic scattering and absorption mapping of debris flows, feeding paths, and tectonic units at Mount St. Helens volcano

Acknowledgments We thank Edoardo Del Pezzo, Ludovic Margerin, Haruo Sato, Mare Yamamoto, Tatsuhiko Saito, Malcolm Hole, and Seth Moran for the valuable suggestions regarding the methodology and interpretation. Greg Waite provided the P wave velocity model of MSH. An important revision of the methods was done after two blind reviews performed before submission. The suggestions of two anonymous reviewers greatly enhanced our ability of imaging structures, interpreting our results, and testing their reliability. The facilities of the IRIS Data Management System, and specifically the IRIS Data Management Center, were used for access to waveform and metadata required in this study, and provided by the Cascades Volcano Observatory – USGS. Interaction with geologists and geographers part of the Landscape Dynamics Theme of the Scottish Alliance for Geoscience, Environment and Society (SAGES) has been important for the interpretation of the results.

Assessment of expected damage on buildings subjected to Lorca earthquake through an energy-based seismic index method and nonlinear dynamic response analyses

The city of Lorca (Spain) was hit on May 11th, 2011, by two consecutive earth-quakes of magnitudes 4.6 and 5.2 Mw, causing casualties and important damage in buildings. Many of the damaged structures were reinforced concrete frames with wide beams. This study quantifies the expected level of damage on this structural type in the case of the Lorca earth-quake by means of a seismic index Iv that compares the energy input by the earthquake with the energy absorption/dissipation capacity of the structure. The prototype frames investigated represent structures designed in two time periods (1994–2002 and 2003–2008), in which the applicable codes were different. The influence of the masonry infill walls and the proneness of the frames to concentrate damage in a given story were further investigated through nonlinear dynamic response analyses. It is found that (1) the seismic index method predicts levels of damage that range from moderate/severe to complete collapse; this prediction is consistent with the observed damage; (2) the presence of masonry infill walls makes the structure very prone to damage concentration and reduces the overall seismic capacity of the building; and (3) a proper hierarchy of strength between beams and columns that guarantees the formation of a strong column-weak beam mechanism (as prescribed by seismic codes), as well as the adoption of counter-measures to avoid the negative interaction between non-structural infill walls and the main frame, would have reduced the level of damage from Iv=1 (collapse) to about Iv=0.5 (moderate/severe damage)

Thermal Treatments of Fe—Mn Alkoxide of Glycerol: Infrared absorption and emission

Synthetic Fe—Mn alkoxide of glycerol samples are submitted to controlled heating conditions and examined by IR absorption spectroscopy. On the other hand, the same sample is studied by infrared emission spectroscopy (IRES), upon heating in situ from 100 to 600°C. The spectral techniques employed in this contribution, especially IRES, show that as a result of the thermal treatments ferromagnetic oxides (manganese ferrite) are formed between 350 and 400°C. Some further spectral changes are seen at higher temperatures.

Optical absorption and EPR studies on tenorite mineral

Optical absorption and EPR studies of the mineral tenorite, a cupric oxide, which originated from Mexico and contains 54.40 wt% of CuO. EPR spectral results indicate two Cu(II) closely interacting ions to give a d2 type structure. The calculated spin Hamiltonian at Rt and LNT are g = 2.160 and D = 125 G . The intensity of resonance line is not the same in low and high field regions. The optical absorption spectrum is due to Cu(II) which three sets of energies indicating Cu(II) in two independent tetragonal C4v symmetry, in addition to d2 structure of octahedral coordination. The octahedral and tetragonal field parameters are compared with those reported for several other copper containing minerals.

Seismic performance of brick infilled RC frame structures in low and medium rise buildings in Bhutan

The construction of reinforced concrete buildings with unreinforced infill is common practice even in seismically active country such as Bhutan, which is located in high seismic region of Eastern Himalaya. All buildings constructed prior 1998 were constructed without seismic provisions while those constructed after this period adopted seismic codes of neighbouring country, India. However, the codes have limited information on the design of infilled structures besides having differences in architectural requirements which may compound the structural problems. Although the influence of infill on the reinforced concrete framed structures is known, the present seismic codes do not consider it due to the lack of sufficient information. Time history analyses were performed to study the influence of infill on the performance of concrete framed structures. Important parameters were considered and the results presented in a manner that can be used by practitioners. The results show that the influence of infill on the structural performance is significant. The structural responses such as fundamental period, roof displacement, inter-storey drift ratio, stresses in infill wall and structural member forces of beams and column generally reduce, with incorporation of infill wall. The structures designed and constructed with or without seismic provision perform in a similar manner if the infills of high strength are used.