Application of Deep Compaction Techniques to Liquefaction Prevention

This article analyzes the application of dynamic compaction, vibroflotation and vibroreplacement (stone columns) to liquefaction prevention. The ground types to which they can be applied, the depths that can be reached and the degree of improvement that can be obtained are all studied. Finally, and on the basis of the above, basic guidelines are given for the design of ground improvement with these techniques and for the aforementioned purpose

Geometry, kinematics and rates of deformation in a normal fault segment boundary, central Greece

The geometry, kinematics and rates of deformation within a fault segment boundary between the ends of two major active normal fault segments have been investigated through examination of a faulted 126 ka marine terrace. Slip‐vector azimuths defined by striations on the faults indicate N‐S extension on c. E‐W faults, sub‐parallel to those from earthquake focal mechanisms, together with significant and contemporaneous E‐W extension on c. N‐S faults. Summed rates of E‐W extension along a c. 550 m transect (0.17 mm/yr) are comparable with those for N‐S extension (0.20 mm/yr) along a c. 350 m transect. Our observations show that distributed non‐plane strain extension occurs in fault segment boundaries and this should be noted when studying fault‐tip fracture toughness and regional deformation rates

Electropolymerization and Morphologic Characterization of α-Tetrathiophene

In this research, poly(α-tetrathiophene), poly(α-TTP), was potentiostatic and potentiodynamically electrosynthesized on Pt and F-doped SnO2 electrodes. The solvent effect (CH2Cl2 and CH3CN) on the nucleation and growth mechanism, NGM, and morphology of the respective deposit was established by potentiostatic method and scanning electron microscopy (SEM), respectively. Potentiodynamic electropolymerization at low sweep rates proved to favor the obtention of a polymer with a more uniform morphology and, in addition, its capacitance as capacitor increased and the p-doping/undoping relationship is close to one (reversible doping). On the other hand, when potentiostatic electropolymerization was realized, deconvolution of the obtained j/t transients revealed that under all conditions, the main contribution to electrolysis at high times (greater than 20 s) was instantaneous nucleation with 3D growth. Nevertheless, the contribution of instantaneous nucleation with 2D growth is always more important in the early stages of the process. However, regardless of the conditions employed in the electropolymerization, the use of an oligomer as starting unit, such as α-TTF, affords deposits with more homogeneous morphology than when the respective monomer is used. Therefore, the information gathered in the current work constitutes a significant contribution that validates the proposed model for the electropolymerization mechanism

Pseudo-transient Continuation, Solution Update Methods, and CFL Strategies for DG Discretizations of the RANS-SA Equations

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/106459/1/AIAA2013-2686.pd

Mo(SxOy) thin films deposited by electrochemistry for application in organic photovoltaic cells

In this study, Mo(SxOy) thin films were deposited onto fluorine doped tin oxide (FTO) using pulsed electrochemical deposition method. It is shown by scanning electron microscopy, energy-dispersive spectroscopy and X-ray photoelectron spectroscopy that after water cleaning the deposited Mo(SxOy) film corresponds to a hybrid layer MoSx:MoO3. This hybrid is used as anode buffer layer (ABL) in planar organic photovoltaic cells (OPVCs) based on the couple copper-phthalocyanine/fullerene. It is shown that it is necessary to proceed to a soft annealing-5 min at 150 °C- of the anode FTO/Mo(SxOy) to clean the ABL surface in order to obtain efficient contact with the organic material. The OPVC with the optimum Mo(SxOy) thickness, 12 nm, showed a power conversion efficiency, PCE = 1.41% under an illumination of AM1.5, which is 12% higher than that achieved with a simple MoO3 ABL. This improvement is attributed to the fact that using a hybrid MoS2:MoO3 ABL allows to combine the advantages of its both constituents. The MoSx blocks the electrons, while the high work function of MoO3 induces a high hole extraction efficiency at the interface electron donor/anode

Searching two or more databases decreased the risk of missing relevant studies: a metaresearch study

BACKGROUND AND OBJECTIVES: Assessing changes in coverage, recall, review, conclusions and references not found when searching fewer databases. METHODS: In randomly selected 60 Cochrane reviews, we checked included study publications' coverage (indexation) and recall (findability) using different search approaches with MEDLINE, Embase, and CENTRAL and related them to authors' conclusions and certainty. We assessed characteristics of unfound references. RESULTS: Overall 1989/2080 included references, were indexed in ≥1 database (coverage = 96%). In reviews where using one of our search approaches would not change conclusions and certainty (n = 44-54), median coverage and recall were highest (range 87.9%-100.0% and 78.2%-93.3%, respectively). Here, searching ≥2 databases reached >95% coverage and ≥87.9% recall. In reviews with unchanged conclusions but less certainty (n = 2-8): 63.3%-79.3% coverage and 45.0%-75.0% recall. In reviews with opposite conclusions (n = 1-3): 63.3%-96.6% and 52.1%-78.7%. In reviews where a conclusion was no longer possible (n = 3-7): 60.6%-86.0% and 20.0%-53.8%. The 265 references that were indexed but unfound were more often abstractless (30% vs. 11%) and older (28% vs. 17% published before 1991) than found references. CONCLUSION: Searching ≥2 databases improves coverage and recall and decreases the risk of missing eligible studies. If researchers suspect that relevant articles are difficult to find, supplementary search methods should be used

Rapid fabrication and characterization of sine wave targets

The effect of surface perturbations on Inertial Confinement Fusion target performance is currently being researched at Los Alamos National Laboratory (LANL). These perturbations can cause hydrodynamic instabilities which in turn reduce the targets` yield. To systematically measure the growth of these instabilities requires targets to be produced which have perturbations of a known amplitude and spatial frequency. The authors have recently assembled hardware onto one of their diamond turning lathes which enables them to machine and measure these sine waves in about 15 minutes. This is a significant reduction in time from the two and one half hours required by the previous method. This paper discusses the hardware, how it works, and how well the system is working for them to produce these targets

Asperities and barriers on the seismogenic zone in North Chile: state-of-the-art after the 2007 Mw 7.7 Tocopilla earthquake inferred by GPS and InSAR data

The Mw 7.7 2007 November 14 earthquake had an epicentre located close to the city of Tocopilla, at the southern end of a known seismic gap in North Chile. Through modelling of Global Positioning System (GPS) and radar interferometry (InSAR) data, we show that this event ruptured the deeper part of the seismogenic interface (30–50 km) and did not reach the surface. The earthquake initiated at the hypocentre and was arrested ~150 km south, beneath the Mejillones Peninsula, an area already identified as an important structural barrier between two segments of the Peru–Chile subduction zone. Our preferred models for the Tocopilla main shock show slip concentrated in two main asperities, consistent with previous inversions of seismological data. Slip appears to have propagated towards relatively shallow depths at its southern extremity, under the Mejillones Peninsula. Our analysis of post-seismic deformation suggests that small but still significant post-seismic slip occurred within the first 10 d after the main shock, and that it was mostly concentrated at the southern end of the rupture. The post-seismic deformation occurring in this period represents ~12–19 per cent of the coseismic deformation, of which ~30–55 per cent has been released aseismically. Post-seismic slip appears to concentrate within regions that exhibit low coseismic slip, suggesting that the afterslip distribution during the first month of the post-seismic interval complements the coseismic slip. The 2007 Tocopilla earthquake released only ~2.5 per cent of the moment deficit accumulated on the interface during the past 130 yr and may be regarded as a possible precursor of a larger subduction earthquake rupturing partially or completely the 500-km-long North Chile seismic gap