Determination Of The Orientation Of Open Fractures From Hydrophone VSP

Open fractures are of interest in many areas such as ground water contamination, hazardous waste disposal, oil and gas recovery, and geothermal energy extraction. In borehole geophysics and engineering, fractures are usually located by acoustic borehole televiewer logging, however, not all of the observed fractures are permeable. The caliper log, on the other hand, provides the information about the change of borehole diameter, but increasing diameter does not prove the existence of open fractures. Nor can the combination of these two methods-televiewer logs and caliper logs-provide direct information about open fractures. However, tube waves, generated by P- and/or S-waves in hydrophone vertical seismic profiling (VSP) or cross-well seismic profiling section can detect open fractures intersecting the borehole. A new technique is developed to determine the orientation of open fractures using the normalized ratios of an S-wave-generated tube wave to a P-wave-generated tube wave. The fracture orientations determined by this method represent the average over the fracture planes for large radii, generally on the order of a meter. Numerical tests show that, given a good experiment design, a set of two independent measurements of these ratios with polarization information, or a set of three independent measurements without polarization information, provides a unique solution. The developed technique is stable in the presence of noise. This technique is applied to hydrophone VSP data from the Kent Cliffs test well in southeastern New York state. The orientations of the three major fractures which generate primary tube waves in the seismic profiling sections are obtained. The results agree well with the orientations measured from the borehole televiewer images in general. Any discrepancy may be attributed to the difference between the sampling size of this method and the borehole televiewer, to the deviation of rays from the straight lines due to inhomogeneity, and/or to possible BH-wave motion due to anisotropy and lateral inhomogeneity.Massachusetts Institute of Technology. Earth Resources Laborator

Higher-order elastic properties of single crystalline corundum

Corundum is frequently used for high-pressure and high-temperature applications. Its second-order pressure derivatives are, however, not measurable. A static rigid-ion lattice model for corundum, utilizing exponential-type repulsive force, is developed. The lattice parameters are determined from measured data of the bulk modulus and C33. Using these lattice parameters first-order pressure derivatives of bulk modulus and C33 are computed and compared to measured values, respectively. The deviations do not exceed 33%. The second-order pressure derivatives of bulk modulus and C33 are predicted and the results come out positive. These are usually negative for oxide mineral of cubic structure

Use of Adjacent Knot Data in Predicting Bending Strength of Dimension Lumber by X-Ray

In a previous study, the knot depth ratio (KDR) evaluation method was proposed to quantify the area of knots in a cross-section. That study reported that bending strength can be predicted by KDR analysis. However, the KDR model did not take into consideration the additional strength reduction caused by adjacent knots. It was found that the prediction of lumber strength was improved when adjacent knots were taken into consideration. Analysis using the KDRA (KDR adding knots) model revealed that the optimum cross-sectional interval, an input variable, is directly affected by knot size parallel to lumber length (KSPLL). KSPLL depends on the sawing method and log characteristics, and for species containing large knots, the cross-sectional interval is likely to be extremely wide. This can cause several adjacent small knots to be excluded from the analysis, requiring modification of the KDRA model algorithm. This modification resulted in improvement in the precision of the strength prediction, although the input variable of the cross-sectional interval was not used. The R2 values obtained using this method were 0.60 and 0.56 for Japanese larch and red pine, respectively

A Liquidity-Based Resolution of the Uncovered Interest Parity Puzzle

A new monetary theory is set out to resolve the “Uncovered Interest Parity Puzzle (UIP Puzzle)”. It explores the possibility that liquidity properties of money and nominal bonds can account for the puzzle. A key concept in our model is that nominal bonds carry liquidity premium due to their medium of exchange role as either collateral or means of payment. In this framework no-arbitrage condition ensures a positive comovement of real return on money and nominal bonds. Thus, when inflation in one country becomes relatively lower, i.e., real return on this currency is relatively higher, its nominal bonds should also yield higher real return. We show that their nominal returns can also become higher under the economic environment where collateral pledgeability and/or liquidity of nominal bonds and/or collateralized credit based transactions are relatively bigger. Since a currency with lower inflation is expected to appreciate, the high interest currency does indeed appreciate in this case, i.e., the UIP puzzle is no longer an anomaly in our model. Our liquidity based theory in fact has interesting implications on many empirical observations that risk based explanations find difficult to reconcile with

A Liquidity-Based Resolution of the Uncovered Interest Parity Puzzle

A new monetary theory is set out to resolve the “Uncovered Interest Parity Puzzle (UIP Puzzle)”. It explores the possibility that liquidity properties of money and nominal bonds can account for the puzzle. A key concept in our model is that nominal bonds carry liquidity premium due to their medium of exchange role as either collateral or means of payment. In this framework no-arbitrage condition ensures a positive comovement of real return on money and nominal bonds. Thus, when inflation in one country becomes relatively lower, i.e., real return on this currency is relatively higher, its nominal bonds should also yield higher real return. We show that their nominal returns can also become higher under the economic environment where collateral pledgeability and/or liquidity of nominal bonds and/or collateralized credit based transactions are relatively bigger. Since a currency with lower inflation is expected to appreciate, the high interest currency does indeed appreciate in this case, i.e., the UIP puzzle is no longer an anomaly in our model. Our liquidity based theory in fact has interesting implications on many empirical observations that risk based explanations find difficult to reconcile with

A Liquidity-Based Resolution of the Uncovered Interest Parity Puzzle

A new monetary theory is set out to resolve the “Uncovered Interest Parity Puzzle (UIP Puzzle)”. It explores the possibility that liquidity properties of money and nominal bonds can account for the puzzle. A key concept in our model is that nominal bonds carry liquidity premium due to their medium of exchange role as either collateral or means of payment. In this framework no-arbitrage condition ensures a positive comovement of real return on money and nominal bonds. Thus, when inflation in one country becomes relatively lower, i.e., real return on this currency is relatively higher, its nominal bonds should also yield higher real return. We show that their nominal returns can also become higher under the economic environment where collateral pledgeability and/or liquidity of nominal bonds and/or collateralized credit based transactions are relatively bigger. Since a currency with lower inflation is expected to appreciate, the high interest currency does indeed appreciate in this case, i.e., the UIP puzzle is no longer an anomaly in our model. Our liquidity based theory in fact has interesting implications on many empirical observations that risk based explanations find difficult to reconcile with

A Liquidity-Based Resolution of the Uncovered Interest Parity Puzzle

A new monetary theory is set out to resolve the “Uncovered Interest Parity Puzzle (UIP Puzzle)”. It explores the possibility that liquidity properties of money and nominal bonds can account for the puzzle. A key concept in our model is that nominal bonds carry liquidity premium due to their medium of exchange role as either collateral or means of payment. In this framework no-arbitrage condition ensures a positive comovement of real return on money and nominal bonds. Thus, when inflation in one country becomes relatively lower, i.e., real return on this currency is relatively higher, its nominal bonds should also yield higher real return. We show that their nominal returns can also become higher under the economic environment where collateral pledgeability and/or liquidity of nominal bonds and/or collateralized credit based transactions are relatively bigger. Since a currency with lower inflation is expected to appreciate, the high interest currency does indeed appreciate in this case, i.e., the UIP puzzle is no longer an anomaly in our model. Our liquidity based theory in fact has interesting implications on many empirical observations that risk based explanations find difficult to reconcile with

Stability of generalized additive Cauchy equations

A familiar functional equation f(ax+b)=cf(x) will be solved in the class of functions f:ℝ→ℝ. Applying this result we will investigate the Hyers-Ulam-Rassias stability problem of the generalized additive Cauchy equation f(a1x1+⋯+amxm+x0)=∑i=1mbif(ai1x1+⋯+aimxm) in connection with the question of Rassias and Tabor