Moment Tensor Analysis of Acoustic Emissions Induced by Laboratory-based Hydraulic Fracturing in Granite,

Moment Tensors of hydraulically induced AEs: Hydraulic fracturing is an important technique in the development of enhanced geothermal systems and unconventional resources. Although the fracture modes induced by hydraulic fracturing influence the recovery efficiency of the resources, the current understanding of this relationship is insufficient. In this study, we considered the acoustic emissions (AEs) induced during hydraulic fracturing under uniaxial loading conditions in the laboratory, and applied a moment tensor analysis by carefully correcting the coupling condition and directivity of AE transducers. Experiments were conducted for two types of Kurokami–jima granite samples: those with a rift plane perpendicular (Type H) or parallel (Type V) to the expected direction of fracture propagation (i.e. along the loading axis). In the experiments, both sample types experienced a significant number of shear, tensile and compressive events. The dominant fracture mode for Type H samples is found to be tensile events in which the fracture plane is parallel to the loading axis, whereas for Type V samples, shear events are dominant. This difference suggests that the dominant fracture modes induced by hydraulic fracturing are highly dependent on the relationship between the direction of fracture propagation and orientation of pre-existing weak planes

8-14 translocation in a Japanese Burkitt's lymphoma.

Chromosome analysis was performed on cells obtained from the pleural effusion of a Japanese patient with Burkitt's lymphoma. Two modal chromosomal numbers were found: 45 and 46. Five different karyotypes were present, all having a t (8q-;14q+) translocation. This case illustrates that Burkitt's lymphomas of Japanese are no exception to the frequent association of this chromosomal abnormality with Burkitt's lymphomas.</p

Coordinately Co-opted Multiple Transposable Elements Constitute an Enhancer for wnt5a Expression in the Mammalian Secondary Palate

Acquisition of cis-regulatory elements is a major driving force of evolution, and there are several examples of developmental enhancers derived from transposable elements (TEs). However, it remains unclear whether one enhancer element could have been produced via cooperation among multiple, yet distinct, TEs during evolution. Here we show that an evolutionarily conserved genomic region named AS3_9 comprises three TEs (AmnSINE1, X6b_DNA and MER117), inserted side-by-side, and functions as a distal enhancer for wnt5a expression during morphogenesis of the mammalian secondary palate. Functional analysis of each TE revealed step-by-step retroposition/transposition and co-option together with acquisition of a binding site for Msx1 for its full enhancer function during mammalian evolution. The present study provides a new perspective suggesting that a huge variety of TEs, in combination, could have accelerated the diversity of cis-regulatory elements involved in morphological evolution

Chromosome 14q+ in a Japanese patient with Burkitt's lymphoma.

Cytogenetic studies were performed on a biopsy specimen of a jaw tumor and on a bone marrow aspirate from a Japanese patient with Epstein-Barr virus-negative Burkitt's lymphoma. A 14q + chromosome was found in cells from either source, although each contained a different clone. Other karyotypic abnormalities present in common included 2dir dup (1q) (q21 leads to q32), 3q+, 6p--, +12, +mar.</p

Low Frequency Spectroscopy of the Correlated Metallic System CaxSr12xVO3

We study the photoemission and optical conductivity response of the strongly correlated metallic system CaxSr1-xVO3. We find that the basic features of the transfer of spectral weight in photoemission experiments and the unusual line shape of the optical response can be understood by modeling the system with a one-band Hubbard model close to the Mott-Hubbard transition. We present a detailed comparison between the low frequency experimental data and the corresponding theoretical predictions obtained within the local impurity self-consistent approximation that is exact in the limit of large lattice connectivity

Monitoring hydraulically-induced fractures in the laboratory using acoustic emissions and the fluorescent method

We investigated the relation between seismic events and fractures induced by hydraulic fracturing in laboratory experiments under uniaxial loading conditions using granite and shale blocks by monitoring acoustic emissions (AEs). We used a thermosetting acrylic resin mixed with a fluorescent compound as the fracturing fluid and fixed it within the blocks by heating immediately after fracturing. This allowed observation of fluid penetration regions and fracturing patterns on cross-sectional planes under ultraviolet light irradiation. The obtained AE hypocenters and resin penetration regions observed after the fracturing extended on both wings along the loading axis from the fracturing hole for all the samples. This was as expected theoretically, although the AEs were concentrated primarily on only one side for some samples. Patterns of wellbore pressurization histories, AE activities, and resin penetration regions were significantly different between the two rock types. In the experiments using granite samples, wellbore pressure increased linearly until 87.2–97.4% of the peak pressure, followed by a gradual decrease of the rate and sudden drop of pressure (breakdown). AEs started to occur at 49.6–93.2% of the peak pressure, significantly before the breakdown. Resin penetration regions have a width of 10–30 mm and such wide penetration regions resulted in indistinguishable main fractures. For the shale samples, both the nonlinearity of the wellbore pressure–time curve and the AE activity were initiated immediately before breakdown. The number of detected AEs was much smaller than for the granites. Resin in the rock samples showed thin traces with widths of < 1 mm, corresponding to the main fracture. Such dissimilarities between the two rock types likely resulted from differences in their permeability, grain size, and/or mineralogy. We also found aseismic regions that lacked AEs despite evidence of fluid penetration. Although such regions were affected by the fracturing operations, they cannot be revealed by the microseismic observations used in shale gas/oil fields and enhanced geothermal systems