[1] We characterized the effect of large-scale (>20 mm) soil physical structure on the age and recalcitrance of soil organic carbon (SOC) in upper (A) and lower (B) horizons of grassland soils from California’s Central Valley. The radiocarbon content of SOC from surfaces and interiors of large-scale soil structural units (‘‘peds’’) was measured in order to characterize the spatial distribution ...

This study aims to evaluate the efficiency of the concentration-number (C-N) fractal model for discrimination of soil horizon regarding the depth distribution profile. In this regard, soil parameters such as pH, organic carbon content, calcareous mineral content, electrical conductivity and available phosphorus of Ziarat forestland in Golestan Province, north of Iran, has been investigated. The...

horizons on a precision farming research site in Barnes County, North Dakota for precisely these reasons. An Although pedogenesis and landscape evolution have occurred on intriguing aspect of this work concerns the fact that soils the eastern North Dakota till plain since the inception of the Holocene, soils with argillic horizon are recognized on a very limited basis. with argillic horizons ha...

In this paper, we show a simple way to derive the p-shift finite impulse response (FIR) unbiased estimator (UE) recently proposed by Shmaliy for time-invariant discrete-time state-space models. We also examine its iterative Kalman-like form. We conclude that the Kalman-like algorithm can serve efficiently as an optimal estimator with large averaging horizons. It has better engineering features ...

In this article, we forecast crude oil and natural gas spot prices at a daily frequency based on two classification techniques: artificial neural networks (ANN) and support vector machines (SVM). As a benchmark, we utilize an autoregressive integrated moving average (ARIMA) specification. We evaluate outof-sample forecast based on encompassing tests and mean-squared prediction error (MSPE). We ...

We study the classical stability of a class of S-brane geometries having cosmological horizons. By considering the perturbations of the metric in these ge-ometries we establish that their horizons are unstable in the sense that an observer trying to cross the horizon experiences an infinite flux of radiation at the instant of crossing. The backreaction of this radiation is likely to convert the...

Quite recently, some new mathematical approaches to black holes have appeared in the literature. They do not rely on the classical concept of event horizon — which is very global, but on a the local concept of hypersurfaces foliated by trapped surfaces. After a brief introduction to these new horizons, we focus on a viscous fluid analogy that can be developed to describe their dynamics, in a fa...