bluuebunny/crossref_metadata_2025_split huggingface dataset:
On the predictability of volcano-tectonic events by low frequency seismic noise analysis at Teide-Pico Viejo volcanic complex, Canary Islands
Authors: Tárraga M. , Carniel R. , Ortiz R. , Marrero J. M. , García A. 
Published: April 2010

Abstract. The island of Tenerife (Canary Islands, Spain), is showing possible signs of reawakening after its last basaltic strombolian eruption, dated 1909 at Chinyero. The main concern relates to the central active volcanic complex Teide - Pico Viejo, which poses serious hazards to the properties and population of the island of Tenerife (Canary Islands, Spain), and which has erupted several times during the last 5000 years, including a subplinian phonolitic eruption (Montaña Blanca) about 2000 years ago. In this paper we show the presence of low frequency seismic noise which possibly includes tremor of volcanic origin and we investigate the feasibility of using it to forecast, via the material failure forecast method, the time of occurrence of discrete events that could be called Volcano-Tectonic or simply Tectonic (i.e. non volcanic) on the basis of their relationship to volcanic activity. In order to avoid subjectivity in the forecast procedure, an automatic program has been developed to generate forecasts, validated by Bayes theorem. A parameter called "forecast gain" measures (and for the first time quantitatively) what is gained in probabilistic terms by applying the (automatic) failure forecast method. The clear correlation between the obtained forecasts and the occurrence of (Volcano-)Tectonic seismic events - a clear indication of a relationship between the continuous seismic noise and the discrete seismic events - is the explanation for the high value of this "forecast gain" in both 2004 and 2005 and an indication that the events are Volcano-Tectonic rather than purely Tectonic.
Calendaricities and multimodality in the Eastern Mediterranean cyclonic activity
Authors: Osetinsky I. , Alpert P. 
Published: April 2010

Abstract. Calendaricities, or the occurrence of weather anomalies on fixed calendar dates, are investigated for the Eastern Mediterranean (EM). The anomalies discussed here are the maxima and minima in the frequency of occurrence of the EM synoptic systems bearing rainfall. Those are mostly the Winter Lows passing over Cyprus en route eastward of the Ionian Sea where they are generated in situ or come to from N. Italy. The Winter Lows produce the rainfall over the central and northern EM areas, including Cyprus, Israel, Lebanon, NW Syria, W. Jordan. The southern EM areas, i.e. S. Israel and NE Egypt, get rainfall followed by floods due to the Winter Lows as well, and in addition, due to a small proportion of the mostly dry Red Sea Troughs that occasionally turn out to cause heavy rainfall. The analysis of the daily resolved data based on the NCEP/NCAR reanalysis is carried out. A comparison of two 28-yr periods, 1948–1975 and 1976–2003, different in global climatology, showed their similarity in the timing of peaks in EM cyclonic activity. The winter was found to have five maxima of cyclonic activity, centered on early February and nearly bell-shaped over their magnitudes. This supports the earlier hypotheses of multimodality in the EM rainfall. The Red Sea Troughs have their main peak of occurrence in the late October – early November, and their small rain-bearing proportion falls as well on this period of a year.
Fractional Fourier approximations for potential gravity waves on deep water
Authors: Lukomsky V. P. , Gandzha I. S. 
Published: April 2010

Abstract. In the framework of the canonical model of hydrodynamics, where fluid is assumed to be ideal and incompressible, waves are potential, two-dimensional, and symmetric, the authors have recently reported the existence of a new type of gravity waves on deep water besides well studied Stokes waves (Lukomsky et al., 2002b). The distinctive feature of these waves is that horizontal water velocities in the wave crests exceed the speed of the crests themselves. Such waves were found to describe irregular flows with stagnation point inside the flow domain and discontinuous streamlines near the wave crests. In the present work, a new highly efficient method for computing steady potential gravity waves on deep water is proposed to examine the character of singularity of irregular flows in more detail. The method is based on the truncated fractional approximations for the velocity potential in terms of the basis functions 1/(1 - exp(y0 - y - ix))n, y0 being a free parameter. The non-linear transformation of the horizontal scale x = c - g sin c, 0 < g < 1, is additionally applied to concentrate a numerical emphasis on the crest region of a wave for accelerating the convergence of the series. For lesser computational time, the advantage in accuracy over ordinary Fourier expansions in terms of the basis functions exp(n(y + ix)) was found to be from one to ten decimal orders for steep Stokes waves and up to one decimal digit for irregular flows. The data obtained supports the following conjecture: irregular waves to all appearance represent a family of sharp-crested waves like the limiting Stokes wave but of lesser amplitude.
Instabilities in a thin current sheet and their consequences
Authors: Singh N. 
Published: April 2010

Abstract. Using a fully 3-D particle in-cell simulation, we studied the electrodynamics of a thin current sheet (CS). Starting with a uniform plasma and anti-parallel magnetic field, Harris equilibrium is achieved during the early stage of the simulation. In the processes of reaching the equilibrium, both electrons and ions in the newly formed CS are energized and develop pitch-angle anisotropies. We find two distinct stages of primarily electrostatic instabilities; in the first stage the relative drift between electrons and ions drives the instability in the central regions of the CS. The electrostatic fluctuations scatter electrons causing current disruption in the central region. The associated reduction in the average drift velocity of the current-carrying electrons generates sheared flow. The second stage of the instability begins when the drift velocity develops a minimum in the central plane. Then the shear and the growing electrostatic fluctuations under the condition of the maintained anti-parallel driving magnetic field configuration feed each other making the instability explosive. The growing fluctuations create plasma clumps as the electrons and ions are progressively trapped in the large-amplitude waves. The density clumping also generates clumps in the current. The non-uniform current distribution causes magnetic reconnection, accompanied by heating of electrons and ion at a fast rate and nearly complete bifurcation of the current sheet. Anomalous resistivity during different stages of the evolution of the CS is calculated and compared against theory.
Anisotropic scaling features and complexity in magnetospheric-cusp: a case study
Authors: Yordanova E. , Bergman J. , Consolini G. , Kretzschmar M. , Materassi M. , Popielawska B. , Roca-Sogorb M. , Stasiewicz K. , Wernik A. W. 
Published: April 2010

Abstract. Magnetospheric cusps are high-latitude regions characterized by a highly turbulent plasma, playing a special role in the solar wind-magnetosphere interaction. Here, using POLAR satellite magnetic field vector measurements we investigate the anisotropic scaling features of the magnetic field fluctuations in the northern cusp region. Our results seem to support the hypothesis of a 2D-MHD turbulent scenario which is consequence of a strong background magnetic field. The observed turbulent fluctuations reveal a high degree of complexity, which might be due to the interplay of many competing scales. A discussion of our findings in connection with the complex scenario proposed by Chang et al. (2004) is provided.
Stochastic parametric resonance in shear flows
Authors: Poulin F. J. , Scott M. 
Published: April 2010

Abstract. Time-periodic shear flows can give rise to Parametric Instability (PI), as in the case of the Mathieu equation (Stoker, 1950; Nayfeh and Mook, 1995). This mechanism results from a resonance between the oscillatory basic state and waves that are superimposed on it. Farrell and Ioannou (1996a, b) explain that PI occurs because the snap-shots of the velocity profile are subject to transient growth. If the flows were purely steady the transient growth would subside and not have any long lasting effect. However, the coupling between transient growth and the time variation of the basic state create PI. Mathematically, transient growth, and therefore PI, are due to the nonorthogonal eigenspace in the linearized system. Poulin et al. (2003) studied a time-periodic barotropic shear flow that exhibited PI, and thereby produced mixing at the interface between Potential Vorticity (PV) fronts. The instability led to the formation of vortices that were stretched. A later study of an oscillatory current in the Cape Cod Bay illustrated that PI can occur in realistic shear flows (Poulin and Flierl, 2005). These studies assumed that the basic state was periodic with a constant frequency and amplitude. In this work we study a shear flow similar to that found in Poulin et al. (2003), but now where the magnitude of vorticity is a stochastic variable. We determine that in the case of stochastic shear flows the transient growth of perturbations of the snapshots of the basic state still generate PI.
Large- and small-scale turbulent spectra in MHD and atmospheric flows
Authors: Chkhetiani O. G. , Eidelman A. , Golbraikh E. 
Published: April 2010

Abstract. In the present review we discuss certain studies of large- and small-scale turbulent spectra in MHD and atmospheric flows performed by S. S. Moiseev and his co-authors during the last years of his life and continued by his co-authors after he passed away. It is shown that many ideas developed in these works have not lost their novelty and urgency until now, and can form the basis of future studies in this field.
Nonlinear quenching of current fluctuations in a self-exciting homopolar dynamo
Authors: Hide R. 
Published: April 2010

Abstract. In the interpretation of geomagnetic polarity reversals with their highly variable frequency over geological time it is necessary, as with other irregularly fluctuating geophysical phenomena, to consider the relative importance of forced contributions associated with changing boundary conditions and of free contributions characteristic of the behaviour of nonlinear systems operating under fixed boundary conditions. New evidence -albeit indirect- in favour of the likely predominance of forced contributions is provided by the discovery reported here of the possibility of complete quenching by nonlineax effects of current fluctuations in a self-exciting homopolar dynamo with its single Faraday disk driven into rotation with angular speed y(τ) (where τ denotes time) by a steady applied couple. The armature of an electric motor connected in series with the coil of the dynamo is driven into rotation' with angular speed z(τ) by a torque xf (x) due to Lorentz forces associated with the electric current x(τ) in the system (just as certain parts of the spectrum of eddies within the liquid outer core are generated largely by Lorentz forces associated with currents generated by the self-exciting magnetohydrodynamic (MHD) geodynamo). The discovery is based on bifurcation analysis supported by computational studies of the following (mathematically novel) autonomous set of nonlinear ordinary differential equations: dx/dt = x(y - 1) - βzf(x), dy/dt = α(1 - x²) - κy, dz/dt = xf (x) -λz, where f (x) = 1 - ε + εσx, in cases when the dimensionless parameters (α, β, κ, λ, σ) are all positive and 0 ≤ ε ≤ 1. Within those regions of (α, β, κ, λ, σ) parameter space where the applied couple, as measured by α, is strong enough for persistent dynamo action (i.e. x ≠ 0) to occur at all, there are in general extensive regions where x(τ) exhibits large amplitude regular or irregular (chaotic) fluctuations. But these fluctuating régimes shrink in size as increases from zero, and they disappear altogether when ε = 1, leaving only steady régimes of dynamo action.
Formation of vortex clusters on a sphere
Authors: Pavlov V. , Buisine D. , Goncharov V. 
Published: April 2010

Abstract. This paper applies the Hamiltonian Approach (HA) to two-dimensional motions of incompressible fluid in curvi-linear coordinates, in particular on a sphere. The HA has been used to formulate governing equations of motion and to interpret the evolution of a system consisting of N localized two-dimensional vortices on a sphere. If the number of vortices N is large, N ~ 102 - 103 , a small number of vortex collective structures (clusters) is formed. The surprise is that a quasi-final state does not correspond to completely disorganized distribution of vorticity. Numerical analysis has been carried out for initial conditions taken in the form of a few axisymmetric chains of point vortices distributed initially in fixed latitudes. The scheme of Runge-Kutta of 4th order has been used for simulating an evolution of resulting flows. The numerical analysis shows that the Kelvin-Helmholtz instability appears immediately formating initial disorganized structures which are developed and finally "bursted". The system evolves to a few separated vortex "spots" which exist sufficiently for a long time.
Using modern time series analysis techniques to predict ENSO events from the SOI time series
Authors: Salisbury J. I. , Wimbush M. 
Published: April 2010

Abstract. We analyze the monthly 1866-2000 Southern Oscillation Index (SOI) data to determine: 1) whether the SOI data are sufficiently noise-free that useful predictions can be made from them, and 2) in particular, whether future ENSO events can be predicted from the SOI data. The "Hilbert-EMD" technique is used to aid the analysis. This new frequency-time algorithm, based on the Hilbert transform, may be applied to time series for which the conventional assumptions of linearity and stationarity may not apply.With the aid of the EMD procedure, a cleaner representation of ENSO dynamics is obtained from the SOI data. A polynomial function is then used to predict SOI values. Using only the data from January 1866 through December 1996, this prediction correctly indicated a warm event in 1997-1998 and a cold event in 1999. Using all the data (through December 2000), this prediction shows no strong ENSO events (positive or negative) during the time period January 2001 through December 2004.
Simulating biomass assimilation in a Mediterranean ecosystem model using SOFA: setup and identical twin experiments
Authors: Crispi G. , Pacciaroni M. , Viezzoli D. 
Published: April 2010

Abstract. Assessing the potential improvement of basin scale ecosystem forecasting for the Mediterranean Sea requires biochemical data assimilation techniques. To this aim, a feasibility study of surface biomass assimilation is performed following an identical twin experiment approach. NPZD ecosystem data generator, embedded in one eighth degree general circulation model, is integrated with the reduced-order optimal interpolation System for Ocean Forecasting and Analysis. The synthetic "sea-truth" data are winter daily averages obtained from the control run (CR). The twin experiments consist in performing two runs: the free run (FR) with summer-depleted phytoplankton initial conditions and the assimilated run (AR), in which, starting from the same FR phytoplankton concentrations, weekly surface biomasses averaged from the CR data are assimilated. The FR and AR initial conditions modify the winter bloom state of the phytoplankton all over the basin and reduce the total nitrogen, i.e. the energy of the biochemical ecosystem. The results of this feasibility study shows good performance of the system in the case of phytoplankton, zooplankton, detritus and surface inorganic nitrogen. The weak results in the case of basin inorganic nitrogen and total nitrogen, the latter nonperformant at surface, are discussed.
Distribution of overwintering Calanus in the North Norwegian Sea
Authors: Edvardsen A. , Pedersen J. M. , Slagstad D. , Semenova T. , Timonin A. 
Published: April 2010

Abstract. During winter 2003 and 2004, zooplankton and hydrographic data were collected in the northern parts of the Norwegian Sea (68–72° N, 8–17° E) west of the Norwegian shelf break at depths down to 1800 m. The results cover both inter and intra annual changes of hydrography and distribution of Calanus spp. For the whole survey area, average seawater temperature down to 1000 m was higher in 2004 than in the same period in 2003. For the upper 500 m the difference was ca. 1°C. Calanus finmarchicus dominated at ca. 75% of the total copepod abundance. Typical abundance of C. finmarchicus in the survey area was 30 000–40 000 m−2. C. hyperboreus was found deeper than C. finmarchicus while other copepods were found at the depth of C. finmarchicus or shallower. From January to February 2004, the peak of abundance of C. finmarchicus and C. hyperboreus shifted ca. 300 m upwards indicating that ascent from overwintering depth took place at a speed of 10 m d−1 during this period. In general, high abundance of copepods was found adjacent to the shelf slope while oceanic areas had low and intermediate abundance. In the southern part of the survey area, location of high and low copepod abundance shifted both between and within years. In the northern part of the survey area where the shelf slope is less steep, copepods was present at intermediate and high abundance during all surveys.
Cesium and Cesium Compounds
Authors: Bick Manfred , Prinz Horst , Steinmetz Anja 
Published: April 2010

AbstractThe article contains sections titled:1.Physical and Chemical Properties2.Resources3.Production4.Cesium Compounds5.Quality Specifications6.Chemical Analysis7.Storage and Transportation8.Uses9.Economic Aspects10.Toxicology and Occupational Health
Ethers, Aliphatic
Authors: Sakuth Michael , Mensing Thomas , Schuler Joachim , Heitmann Wilhelm , Strehlke Günther , Mayer Dieter 
Published: April 2010

AbstractThe article contains sections titled:1.Introduction2.Properties2.1.Physical Properties2.2.Chemical Properties2.2.1General Aspects2.2.2Peroxide Formation Tendency of Ethers3.Synthesis4.Individual Aliphatic Ethers4.1.Diethyl Ether4.2.Diisopropyl Ether4.3.Other Aliphatic Ethers4.3.1.Di‐n‐propyl Ether4.3.2.Di‐n‐butyl Ether4.3.3.Diamyl Ether4.4.Chloroalkyl Ethers4.4.1.Bis(chloromethyl) Ether4.4.2.Bis(2‐chloroethyl) Ether4.4.3.Bis(2‐chloroisopropyl) Ether5.Toxicology
Hafnium and Hafnium Compounds
Authors: Nielsen Ralph H. , Wilfing Gerhard 
Published: April 2010

AbstractThe article contains sections titled:1.Introduction2.Physical Properties3.Chemical Properties4.Occurrence and Raw Materials5.Production5.1.Ore Cracking5.2.Separation of Zirconium5.3.Winning of Metallic Hafnium5.4.Refining6.Environmental Protection7.Quality Specifications8.Analysis9.Storage and Transportation10.Uses11.Economic Aspects12.Hafnium Compounds12.1.Hafnium Borides12.2.Hafnium Tetrahydroborate12.3.Hafnium Carbide12.4.Hafnium Halides12.5.Hafnium Hydride12.6.Hafnium Nitride12.7.Hafnium Dioxide12.8.Other Derivatives13.Toxicology and Occupational Health
Metallic Soaps
Authors: Nora Angelo , Koenen Gunther 
Published: April 2010

AbstractThe article contains sections titled:1.Introduction2.Production2.1.Raw Materials2.2.Industrial Processes2.2.1.Double Decomposition2.2.2.Direct Reaction with Metal Compounds2.2.3.Direct Reaction with Metals2.3.Plant Equipment2.4.Storage3.Fire and Explosion Protection4.Occupational Health and Environmental Protection5.Individual Metallic Soaps5.1.Sodium Soaps5.2.Potassium Soaps5.3.Lithium Soaps5.4.Magnesium Soaps5.5.Calcium Soaps5.6.Barium Soaps5.7.Aluminum Soaps5.8.Lead Soaps5.9.Copper Soaps5.10.Zinc Soaps5.11.Cadmium Soaps5.12.Manganese Soaps5.13.Iron Soaps5.14.Cobalt Soaps5.15.Nickel Soaps6.Quality Specifications
Organometallic Compounds
Authors: Salzer Albrecht 
Published: April 2010

AbstractThe article contains sections titled:1.Introduction2.Main Group Compounds2.1.Group 12.2.Group 112.3.Group 22.4.Group 122.5.Group 132.6.Group 143.Transition Metal Compounds3.1.Alkyls and Aryls3.2.Carbenes and Carbynes3.3.Carbonyls and Related Compounds3.4.π‐Complexes4.Lanthanoid and Actinoid Compounds
Peptide Synthesis
Authors: Felgenhauer Thomas , Schirwitz Christopher , Breitling Frank 
Published: April 2010

AbstractThe article contains sections titled:1.Introduction2.Fundamentals of Peptide Synthesis3.Strategies for Peptide Synthesis3.1.Solid‐Phase Synthesis3.2.Microwave‐Assisted Peptide Synthesis3.3.Combinatorial Synthesis of Peptides3.4.Peptide Arrays3.5.Other Synthetic Methods4.Chain‐Growing‐, and Side‐Chain Protective Groups4.1.Protection of the α‐Amino Functionality (“Transient Protection”)4.1.1.Base‐Labile Protection of the α‐Amino Functionality4.1.2.Acid‐Labile Protection of the α‐Amino Functionality4.1.3.Other Orthogonal Protective Groups for the α‐Amino Functionality4.2.Side‐Chain Protective Groups (“Permanent Protection”)4.2.1.Side‐Chain Protective Groups for ω‐Carboxylic acids (D, E)4.2.2.Side‐Chain Protective Groups for Amides (N, Q)4.2.3.Side‐Chain Protective Groups for Thioles and Thioethers (C, M)4.2.4.Side‐Chain Protective Groups for the Imidazole Ring (H)4.2.5.Side‐Chain Protection for the Guanidinium Group (R)4.2.6.Side‐Chain Protective groups for ω‐Amines (K)4.2.7.Side‐Chain Protection for ω‐Hydroxyl Groups (S, T, Y)4.2.8.Side‐Chain Protection for Indole Groups (W)5.Coupling Methods—Formation of the Peptide Bond5.1.Diisopropylcarbodiimide (DIC)/N‐Hydroxybenzotriazole (HOBt) Activation5.2.Active Ester Method5.3.Symmetrical/Asymmetrical (Mixed) Anhydride Method5.4.Aminium and Phosphonium Activation5.5.Acid Fluorides6.Side Reactions6.1.Enantiomerization, Oxazolone Formation6.2.Aspartimide Formation6.3.Ornithine‐ and δ‐Lactam Formation7.Summary and Outlook
Characterization of a Classification or Separation Process
Authors: Leschonski Kurt 
Published: April 2010

AbstractThe article contains sections titled:1.Introduction2.Classification Based on Error‐Free Distribution Curves and Mass Balances2.1.Density and Cumulative Distribution Curves2.2.Mass Balances2.3.Indirect Evaluation ofv1andv22.4.Cut Size2.5.Grade Efficiency Curve (Tromp's Curve)2.6.Sharpness of Cut and Other Parameters3.Influence of Stochastic Errors3.1.Indirect Evaluation ofv1andv23.2.Evaluation of the Grade Efficiency Curve,T(x)4.Influence of Systematic Errors4.1.Splitting in the Classifier4.2.Incomplete Dispersion of the Feed Material4.3.Comminution in the Classifier5.Sample Splitting6.Sedimentation Analysis6.1.Calculation of the Equivalent Settling Rate Diameter,xw6.2.Methods of Sedimentation Analysis6.2.1.Suspension Techniques6.2.2.Superimposed Layer Techniques7.Classification Methods7.1.Sieve Analysis7.2.Air Classification7.2.1.Cross‐flow Classifiers7.2.2.Counterflow Classifiers8.Counting Methods8.1.Image Analysis8.2.Electrical Sensing Zone Method8.3.Measurement by Light Scattering or Absorption9.Fraunhofer Diffraction
Distillation, 2. Equipment
Authors: Stichlmair Johann 
Published: April 2010

Abstract

The article contains sections titled:

1.

Introduction

2.

Tray Columns

2.1.

Design Principles

2.2.

Operation Region of Tray Columns

2.3.

Two‐Phase Flow on Trays

2.4.

Mass Transfer in the Two‐Phase Layer

3.

Packed Columns

3.1.

Design Principles

3.2.

Operation Region of Packed Columns

3.3.

Two‐Phase Flow in Packed Columns

3.4.

Mass Transfer in Packed Columns
Disperse Systems, Characterization and Analysis
Authors: Polke Reinhard , Schäfer Michael 
Published: April 2010

AbstractThe article contains sections titled:1.Introduction2.Properties of Disperse Systems and their Relevance for Process Engineering2.1.Objectives of Product Characterization2.1.1.Property Function – Product Model2.1.2.Process Function – Process Model2.1.3.Control of the Process Environment2.1.4.Modeling2.2.Definition of Measurement and Use of Data2.3.Measurement Methods2.4.Mixing Status and Homogeneity2.5.Sensibility and Kinetics of Disperse Systems3.Measuring Methods for Particle Properties4.Measuring Process Technology5.On‐line Characterization6.Outlook