bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Viscoelastic Behavior on Electroconductivity of Recycled Activated Carbon Composites
Authors: Sakai Takenobu , Gushiken Tomohiko , Koyanagi Jun , Ríos-Soberanis Carlos Rolando , Masuko Tomoki , Matsushima Satoshi , Kobayashi Satoshi , Yoneyama Satoru
Published: August 2011

In the Waterworks Bureau, the activated carbon has been used for filtering water. After the life service of activated carbon, it is normally disposed. This work focuses on the processing of a composite material in order to recycle these wasted carbon particles. These activated carbons were used for the filler of composite materials, and a composite with carbon contents of 10% ~ 60% was manufactured and characterized. They exhibited electroconductive behavior because of the carbon particles used as fillers. The electroconductivity have an intimate relationship with the strain of the material. However, because of the composite viscoelasticity, the electroconductivity presented changes by their stress relaxation behavior with the same strain. In this study, it was revealed the relationship between the viscoelasticity and the electroconductivity of recycled activated carbon composites.
Analysis of the High Strain-Rate Behaviour of Polyethylene Based Nanocomposites
Authors: Gorwade Chandragupt , Hughes Foz , Cai Dong Yu , Ashcroft Ian A. , Silberschmidt Vadim V. , Swallowe Gerry , Song Mo , Shaw Steve
Published: August 2011

Advanced polymeric materials and polymer based nanocomposites are finding an increasing range of industrial and defence applications. These materials have the potential to improve combat survivability, whilst reducing cost and weight. This study deals with nanocomposites manufactured from blends of low density polyethylene (LDPE) with various nanofillers. The high strain rate behaviour of these materials was investigated using the split Hopkinson pressure bar (SHPB) test. The experimental results for non-reinforced materials were used as a reference to analyse the effect of the nanofillers on the properties and performance of the nano­composites. These results, together with those obtained from other mechanical tests, will be used as input into finite-element analyses to simulate the performance of these materials in lightweight armour applications. In the first step, the finite element model was validated by simulating the SHPB test and comparing the predicted results with those from the experiments. Explicit finite element analysis was used for the simulation. The fully developed model was able to demonstrate the behaviour of the test bar and specimen interaction correctly and reasonably good agreement between predicted and experimental results was observed.
A Phase Compensation Technique of Sampling Moiré Method for Accurate Single-Shot Phase Analysis
Authors: Ri Shien , Muramatsu Takashi , Saka Masumi
Published: August 2011

Recently, a technique for fast and accurate phase analysis called sampling moiré method has been developed for measurement of small-displacement distribution. In this study, a distribution of phase error caused by linear interpolation in case with mismatch between the sampling pitch and the grating pitch is theoretically analyzed. Moreover, a technique for effective phase compensation is proposed to reduce the periodic phase error. The performance of our compensation method is validated by a computer simulation. Phase analysis can be performed more accurately even in the case that the sampling pitch does not match to the grating pitch strictly.
Speckle Pattern Characterisation for High Resolution Digital Image Correlation
Authors: Crammond G. , Boyd S.W. , Dulieu-Barton Janice M.
Published: August 2011

Digital image correlation (DIC) is an optical technique for full field deformation measurement. The spatial resolution and precision of the measurements are limited by the number of pixels within the image. The use of magnifying optics provides greater spatial resolution images, enabling smaller displacements to be observed with greater accuracy. Increasing the magnification of an image significantly changes the appearance of the non-periodic, stochastic speckle pattern which provides the grey scale contrast necessary for the image correlation method. In the paper a methodology is developed to evaluate the properties of different speckle pattern types under a range of resolutions up to 705 pixel / mm. Numerical deformation of the patterns is also undertaken to evaluate how the changes in the pattern properties affect the accuracy of the DIC measurements.
Ultrasonic Measurement of Residual Stresses in Welded Elements of Ship Structure
Authors: Kudryavtsev Yuri , Kleiman Jacob , Polezhayeva Helena
Published: August 2011

The objective of the study described in this paper is to identify the residual stress distribution and relaxation in standard welded specimens as well as in a large-scale welded panel imitating the critical, from the fatigue point of view, zones of ship structure. The residual stresses were measured after welding and in the process of fatigue loading of welded elements by the UltraMARS system that is based on using ultrasound. The measurements had shown that the maximum residual stresses near the welds (4-5 mm away from the weld) reach levels 290-320 MPa that are close to the yield strength of considered material both in welded specimens and in the large scale panel. Analysis of residual stress relaxation in the welded panel under the action of cyclic loading confirmed the fact that within the interval of applied stress ranges corresponding to the multi-cycle region of loading of the welded joints, the relaxation of residual stresses occurs mainly during the first cycle.
Measurement of Thermomechanical Coupling and its Application in Stress and Damage Analysis
Authors: Dulieu-Barton Janice M.
Published: August 2011

Polymer composites are increasingly being used in high-end and military applications, mainly due to their excellent tailorability to specific loading scenarios and strength/stiffness to weight ratios. The overall purpose of the ongoing research at the University of Southampton is to develop an enhanced understanding of the behaviour of fibre reinforced polymer composites when subjected to a range of loading scenarios. The measurements lecture reviews progress in using the thermoelastic stress analysis technique as a tool that enables a better understanding of the behaviour of polymer composite single skin and sandwich structures.
Determination of X-Ray Elastic Constants for Q1N Submarine Pressure Hull Steel
Authors: Farrell S. P. , Avery K.J. , MacGregor L.W.
Published: August 2011

The Canadian Navy has a requirement to conduct on-site accurate residual stress investigations to improve the efficacy of risk assessment and damage tolerance analysis of critical structures. This paper describes the techniques for qualification of the portable miniature X-ray diffractometer (mXRD) for residual stress analysis on Canadian VICTORIA Class submarine (VCS) pressure hulls. The effect that thermomechanical processing has on the X-ray elastic constant (XREC) and resultant stress analysis is discussed. The approach for calibration of the mXRD equipment and calculation of residual stress values from strain measurements is explained. A new methodology for determination of the XREC, based on the ‘multiple angle method’, is presented discussed and applied to describe the stress-strain relation for tempered Q1N steel. This method, which expands on the ASTM standard, examines the change in lattice strain at multiple y angles (∂dfy /∂sin2y) and provides improved statistical error over the ASTM standard. An XREC of 195 ±6 GPa was experimentally determined for Q1N steel using the {211} crystallographic planes of bcc Fe (using Cr Kα radiation) using the multiple angle method.
Strain Evolution during Lap Shear Testing of SnCu Solder
Authors: Subramanian Sankara J. , Penmetcha Vijay K. R.
Published: August 2011

The lap-shear test is frequently used in the microelectronics industry to obtain mechanical properties of solder joints. In these tests, solder joints formed between slender metallic substrates are pulled apart in a simple shear configuration. Although it is known that calculation of stress-strain curves from lap shear tests is not straightforward due to rotation of the joints and strain inhomogeneity within the joint, these tests still find widespread use due to their simplicity and apparent ease of use. Chawla and co-workers [1, 2] show that the state of strain near the solder-substrate interfaces is significantly different from that in the interior of the joint and that this effect is only minimized for large joints. In the present work, we offer experimental evidence for these conclusions by presenting full-field strain measurements on solder joints in double-lap shear configuration, obtained using Digital Image Correlation (DIC). While confirming that significant strain gradients exist within the joint, the present work also indicates that a simple calculation of shear strain as axial displacement of the joint divided by joint thickness is misleading due to the presence of a significant gradient of the transverse displacement along the loading direction. This gradient persists through the course of the deformation and results in the actual average shear strain in the joint being smaller than that computed from the axial displacement alone.
Model Updating of an Enclosure Using Imaginary Elements
Authors: David-West O.S. , Wang J. , Cooper R.
Published: August 2011

This study was of two phases, one aspect tailored towards matching of the natural frequencies between experimental and finite element results and the second, focused on the effect of damping on the frequency response functions. The experimental Modal Analysis was performed on the real structure to characterize the dynamic behavior in terms of modes, natural frequency and damping using Bruel and Kjaer software. The base of the enclosure was clamped and could be an area of energy dissipation and a source of damping. This boundary condition was model with imaginary joint elements. The dynamic analysis was realized using the Lanczos tool in ANSYS 12 finite element code to extract the modes and also harmonic response analysis was conducted to get the response functions. The linear and rotational stiffness of the boundaries and structural stiffness of the panels were used as updating parameters, tailored towards minimisation of the percentage error in the natural frequencies. The inclusion of damping reduced the amplitude of vibration.
Using Numerical Models to Complement Experimental Setups by Means of Active Control of Mobility
Authors: Jungblut Timo , Wolter Stefan , Matthias Michael , Hanselka Holger
Published: August 2011

The behavior of a component observed after implementation might differ from the characteristic that was determined in laboratory before. These deviations are often caused by discrepancies in the boundary conditions between the field and laboratory environment. Active control of mobility allows replicating the boundary conditions as well as the dynamic behavior of adjoining subsystems within the test facility by means of active systems. Numerical models are used in order to simulate the behavior of the missing subsystems experimentally. Within this contribution two realizations from different fields of engineering are presented.
Analysis of Nonlinear Shear Deformations in CFRP and GFRP Textile Laminates
Authors: Ullah Himayat , Harland Andy R. , Blenkinsopp Robert , Lucas Tim , Price Dan , Silberschmidt Vadim V.
Published: August 2011

Carbon fibre-reinforced polymer (CFRP) and glass fibre-reinforced polymer (GFRP) woven composites are widely used in aerospace, automotive and construction components and structures thanks to their lower production costs, higher delamination and impact strengths. They can also be used in various products in sports industry. These products are exposed to different in-service conditions such as large tensile and bending deformations. Composite materials, especially ±45° symmetric laminates subjected to tensile loads, exhibit significant material as well as geometric non-linearity before damage initiation, particularly with respect to shear deformations. Such a nonlinear response needs adequate means of analysis and investigation, the major tools being experimental tests and numerical simulations. This research deals with modelling the nonlinear deformation behaviour of CFRP and GFRP woven laminates subjected to in-plane tensile loads. The mechanical behaviour of woven laminates is modelled using nonlinear elasto-plastic as well as material models for fabrics in commercial finite-element code Abaqus. A series of tensile tests is carried out to obtain an in-plane full-field strain response of [+45/-45]2s CFRP and GFRP laminates using digital image correlation technique according to ASTM D3518/D3518M-94. The obtained results of simulations are in good agreement with experimental data.
Pulse Phase Thermography and its Application to Kissing Defects in Adhesively Bonded Joints
Authors: Waugh R.C. , Dulieu-Barton Janice M. , Quinn S.
Published: August 2011

The feasibility of using pulse phase thermography (PPT) to identify defects in adhesively bonded joints is assessed. Artificial defects created in solid materials are successfully identified using the phase images produced by PPT. Contaminants typical of those found in the manufacturing environment have been used to recreate kissing defects in joints in polymer composite materials constructed using a single shot process and by using secondary bonding. It is shown that PPT has the potential to identify kissing defects.
Image Analysis for Full-Field Displacement/Strain Data: Method and Applications
Authors: Wang Wei Zhuo , Mottershead John E. , Sebastian Christopher M , Patterson Eann A , Siebert Thorsten , Ihle Alexander , Pipino Andrea
Published: August 2011

Recent advances in measurement techniques, including digital image correlation, automated photoelasticity, electronic speckle pattern interferometry and thermoelastic stress analysis, permit full-field maps of displacement or strain to be obtained easily. They provide large volumes of mostly redundant data, which should be condensed to the essential information to permit straightforward processes such as validations of computational models or damage assessments. A way to do this is by image processing, an important aspect of which is the definition of an orthogonal basis (orthogonal kernel functions). Generally, this is problem dependent and requires some skill from the analyst if the number of image features (the coefficients of the orthogonal basis) is to be restricted to a suitably small number. Advantage may be taken of patterns of symmetry, for example cyclically symmetric patterns are well-suited to treatment by Zernike polynomials and rectangular patterns are well-suited to treatment by Fourier series. The Zernike and Fourier kernels are continuous polynomials with orthogonality properties that require integration and must be discretised. The discrete Tchebichef polynomials are ideal for the treatment of full-field information at multiple discrete data points. In many cases the data field is localised around a particular feature, such as local strain around a hole in a tension-test specimen. In this case, the polynomial basis should similarly be localised by various forms of scaling – this requires the application of the Gram-Schmidt procedure to maintain orthogonality. The image features (sometimes called shape features) are meaningful and may be used to identify particular patterns in the data – e.g. for detecting cracks or other forms of damage. When assembled in a feature vector, the distance between feature vectors from measured and numerical results are useful for refining numerical models. In this paper the principles of image analysis, as applied to full-field displacement/strain data are explained and experimental examples are used to illustrate the practical usefulness of the method. The applications include (i) vibration mode shapes of laminated honeycomb structures and, (ii) strain in an aluminium plate with a central hole in tension.
Dynamic Response of Thermally Bonded Bicomponent Fibre Nonwovens
Authors: Demirci Emrah , Acar Memiş , Pourdeyhimi Behnam , Silberschmidt Vadim V.
Published: August 2011

Having a unique microstructure, nonwoven fabrics possess distinct mechanical properties, dissimilar to those of woven fabrics and composites. This paper aims to introduce a methodology for simulating a dynamic response of core/sheath-type thermally bonded bicomponent fibre nonwovens. The simulated nonwoven fabric is treated as an assembly of two regions with distinct mechanical properties. One region - the fibre matrix – is composed of non-uniformly oriented core/sheath fibres acting as link between bond points. Non-uniform orientation of individual fibres is introduced into the model in terms of the orientation distribution function in order to calculate the structure’s anisotropy. Another region – bond points – is treated in simulations as a deformable bicomponent composite material, composed of the sheath material as its matrix and the core material as reinforcing fibres with random orientations. Time-dependent anisotropic mechanical properties of these regions are assessed based on fibre characteristics and manufacturing parameters such as the planar density, core/sheath ratio, fibre diameter etc. Having distinct anisotropic mechanical properties for two regions, dynamic response of the fabric is modelled in the finite element software with shell elements with thicknesses identical to those of the bond points and fibre matrix.
Strain Analysis of Pipeline Test Specimens Containing Longitudinal and Circumferential Corrosion Defects
Authors: Freire José L. F. , Benjamin Adilson C. , Vieira Ronaldo D. , Diniz Jorge L. C.
Published: August 2011

The elastic and plastic strain data of tubular specimens undergoing rupture under internal pressure tests are presented and analyzed. Six tubular specimens were tested. The specimens were cut from longitudinally welded tubes made of API 5L X80 steel with a nominal outside diameter of 457.2mm (18in) and a nominal wall thickness of 7.93mm (0.312in). Each of the six specimens had one external longitudinal or circumferential corrosion defect that had been machined using spark erosion. Tensile specimens and impact test specimens were tested to determine material properties. Post-yielding electrical resistance strain gages were used to measure the elastic and plastic strains. The failure pressures measured in the laboratory tests were compared with those predicted by the DNV RP-F101 method for single defects and by the Kastner equation. The paper also discusses the strength of the pipe segments used in the tests under the assumptions of following the Tresca rupture criterion.
Determination of All Stress Components of Axisymmetric Stress State in Photoelastic Tomography
Authors: Errapart Andrei
Published: August 2011

In this paper we describe the application of photoelastic tomography for determining stresses in glass. The basic equations of linear approximation in photoelastic tomography are presented. Since these equations permit direct determination only of the axial and shear stress, a method for calculating the other stress components is described. In the case of the residual stresses, it uses the equilibrium equation and the generalized sum rule. In the case of stresses due to external loads, it uses the equilibrium and compatibility equations. It is shown, both graphically and analytically, that integration of these equations must start at the axis and proceed along the positive direction of the radial axis. As an example, residual stresses in the stem of a wine glass are determined. Results are verified by comparing the birefringence, calculated from the determined stress state, with measured birefringence. The numerical algorithm for the case of stresses due to external loads is verified by using the theoretical solution for a Hertzian contact stress problem.
Assessment of the Interface Shear Strength of Metal-Polymer System Based on the Single Filament Fragmentation Test Method
Authors: Thomsen O. T. , Charca S.
Published: August 2011

Among the different test methods to characterize the fibre/matrix interfacial shear strength, the fragmentation test is one of the most simple in terms of experimental setup and the amount of data that can be extracted from one single test. In this work, the fragmentation test method was implemented to assess the interface shear strength obtained for a single steel filament embedded in an unsaturated polyester resin.. The fragment lengths were discriminated and processed using the Kolmogorov-Smirnov and Chi-square fitting test methods showing that the fragment lengths correspond to the extreme statistical distributions. In addition, a very high shear strength (67MPa) of the steel/polyester interface was estimated using the Kelly and Tyson criteria considering the critical fragment length.
Thermoelastic Stress Analysis of T-Stub Model
Authors: Carazo Alvarez D. , Haq M. , Carazo Alvarez J.D. , Patterson Eann A
Published: August 2011

Thermoelastic Stress Analysis (TSA) has been used to obtain the stress field in bolted T-Stub joint models (as defined by Eurocode 3) subject to cyclic loading which were employed to validate a Finite Element (FE) model. It was concluded from the results of the experiments and modeling that the behavior of the T-Stub is more complex than claimed by Eurocode due to contact forces, bolt interaction and plastic behavior.
Residual Stress Interaction against Mechanical Loading during the Manufacturing Process of an Assault Rifle Component
Authors: Urriolagoitia-Sosa G. , Molina-Ballinas A. , Cedeño Verduzco Vistor Fernando , Romero-Ángeles B. , Urriolagoitia-Calderón G. , Hernández-Gómez Luis Héctor , Beltrán-Fernández Juan Alfonso
Published: August 2011

This paper presents results obtained on the harmful effect that a lamination process can cause in AISI 1018 steel during the manufacturing process of spring bed components in fire guns. The sequel presented by the induction of a residual stress field is analyzed as well. It has been established that the consequences produced by the residual stresses, could be minimized either by changing the geometric configuration of the component, or changing the manufacturing process, or regeneration of the microstructure of the material by heat treatment. This work analyzes the effects that consistently become apparent by the regeneration of the microstructure of the material, such as; level of the residual stress field, possible fracture and micro-structural changes. This article evaluates both the longitudinal and transverse residual stress that takes place during the punching process of the spring bed made of AISI 1018 steel. The Crack Compliance Method (CCM) for measurement the residual stress field was applied. Additionally, it is applied a micro-structural analysis of the component. A comparison between experimental results of grain size is shown. From this study it is possible to validate the correct behavior of the mechanical component and certify the expected useful life.
Validation of Impact Simulations of a Car Bonnet by Full-Field Optical Measurements
Authors: Lampeas George , Pasialis Vasilis , Siebert Thorsten , Feligiotti Mara , Pipino Andrea
Published: August 2011

Innovative designs of transport vehicles need to be validated in order to demonstrate reliability and provide confidence. The most common approaches to such designs involve simulations based on Finite Element (FE) analysis, used to study the mechanical response of the structural elements during critical events. These simulations need reliable validation techniques, especially if anisotropic materials, such as fibre reinforced polymers, or complex designs, such as automotive components are considered. It is normal practice to assess the accuracy of numerical results by comparing the predicted values to corresponding experimental data. In this frame, the use of whole field optical techniques has been proven successful in the validation of deformation, strain, or vibration modes [1]. The strength of full-field optical techniques is that the whole displacement field can be visualized and analyzed. By using High Speed cameras, the Digital Image Correlation (DIC) method can be applied to highly non-linear dynamic events and deliver quantitative information about the three-dimensional displacement field [2].
High/Ultra-High Speed Imaging as a Diagnostic Tool
Authors: Reu Phillip L.
Published: August 2011

The ability to see what is happening during an experiment is often critical to human understanding. High and ultra-high speed cameras have for decades allowed scientists to see these extremely short time-scale events; starting with film cameras and now with digital versions of these cameras. The move to digital cameras has invited the use of computer analysis of the images for obtaining quantitative information well beyond the qualitative usefulness of merely being able to see the event. Digital image correlation (DIC) is one of these powerful and popular quantitative techniques, but by no means the only possible image analysis method. All of these analysis techniques ask more of the camera technology than simply providing images. They require high-quality images that are amenable to analysis and do not introduce error sources that compromise the data. Possible error sources include image noise, image distortions, synchronization and spatial sampling issues. As a minimal starting point, the introduced errors must be well understood in order to put error bounds on the results. This is because in many experiments some result is better than no result; with the caveat that the error sources and the relative confidence of the data are understood. The concepts will be framed in relation to ongoing ultra-high speed work being done at Sandia. A call and challenge will be given to begin thinking in more detail about how to successfully turn these cameras into diagnostic instruments.
Damage Observation and Analysis of a Rock Brazilian Disc Using High-Speed DIC Method
Authors: Ma Shao Peng , Yan Dong , Wang Xian , Cao Yan Yan
Published: August 2011

Observation of damage evolution is of great importance to the understanding of the failure process of rock materials. High-speed DIC system is constructed and used to observe the strain field evolution of the granodiorite disc in Brazilian test. The strain fields at different load levels are analyzed based on the stain abnormality indicator (SAI) which is the ratio of the strain measured in experiment to the strain from theoretical solution in an isotropy and elastic model. SAI could be used to indicate the damage in the specimen. The process of damage and failure of the specimen in Brazilian disc test is quantitatively analyzed and deeply discussed according to the strain fields and the statistics of SAI. Experimental results in this paper show that the failure process of the disc specimen in Brazilian test is not simple crack propagation under tensile load, but a complicated damage evolution procedure.
Assessment of the Deformation of Low Density Polymeric Auxetic Foams by X-Ray Tomography and Digital Volume Correlation
Authors: Pierron Fabrice , McDonald Sam A. , Hollis D. , Withers Philip J. , Alderson A.
Published: August 2011

This paper deals with the use of X-ray tomography and Digital Volume Correlation in order to study the mechanical behaviour of a low density polymeric auxetic foam. First, the metrological performances of the procedure are assessed using rigid body translation. Then, tensile test results are analyzed for two load steps and comments on the deformation process of the foam are given with a specific view to Poisson’s effect.
Economic evaluation of OROS® hydromorphone for chronic pain: A Pan-European perspective
Authors: Hauber, PhD A. Brett , Fleischmann, PhD Jochen , Lothgren, PhD Mickael , Wilson, MSPH Michele , Lam, MHEcon Annette , Dubois, MD Dominique , Sabatowski, MD Rainer
Published: August 2011

Objectives: OROS® hydromorphone (osmotic extended-release oral delivery system [OROS] hydromorphone) is a long-acting opioid analgesic, which is approved in Europe for the management of severe pain. The authors aimed to estimate the economic value of this product relative to other widely used oral opioids, including sustained-release morphine, extended-release (ER) oxycodone, and twice-daily (bid) hydromorphone.Design: An adaptable, decision-analytic cost-utility model was developed. Separate versions of the model were developed for five European countries: Germany, Denmark, Slovakia, Portugal, and Italy.Results: OROS hydromorphone represents a cost-effective alternative to other strong oral opioids in the treatment of both nonmalignant and malignant pain in all five countries. In the treatment of chronic severe nonmalignant pain, OROS hydromorphone was dominant (ie, lower cost and incremental quality-adjusted life years gains) when compared with ER oxycodone in Denmark and bid hydromorphone in Germany. Likewise, OROS hydromorphone was dominant in the treatment of chronic severe malignant pain when compared with ER oxycodone in both Germany and Denmark and when compared with bid hydromorphone in all markets where hydromorphone was marketed.Conclusions: This model demonstrates the cost effectiveness of OROS hydromorphone relative to other strong oral opioids in the treatment of chronic severe malignant and nonmalignant pain.
Personal Consumption and Single Persons
Authors: Krueger Kurt V.
Published: August 2011

After examining the competing perspectives regarding single person consumption, this paper makes an effort to improve the quantification of economic losses in cases involving the wrongful death of single persons. I show a new disaggregation of the Consumer Expenditure Survey microdata source which is then used to calculate various economic loss measures warranted by legal jurisdiction and economic thought. Traditional personal consumption methodology computes economic losses as the decedent's earnings multiplied by one minus a personal consumption rate. This paper adds a new method of computing economic losses as the decedent's earnings multiplied by the percent of survivors' or estate's benefit from those earnings. Significant differences result between the methods and in the personal consumption amounts between males and females and wage-earners and non-wage earners of retirement age. It was also discovered that some single-person maintenance consumption results may be applicable to married persons.
The Markov Process Model of Labor Force Activity: Extended Tables of Central Tendency, Shape, Percentile Points, and Bootstrap Standard Errors
Authors: Skoog Gary R. , Ciecka James E. , Krueger Kurt V.
Published: August 2011

This paper updates the Skoog-Ciecka (2001) worklife tables, which used 1997–1998 data, and the Krueger (2005) worklife tables, which used 1998–2004 data. The present paper uses data generated by the methodology Krueger devised in his 2003 PhD dissertation. We have pooled the data beginning January 2005 and continuing through December 2009, a period of five years, using observations matched a year apart. Thus, we have roughly four times the data in the first of the previous studies, and about that of the second. We chose this period for a variety of reasons, including recency, business cycle and trend considerations. The result is the most current and disaggregated set of worklife tables, along with extended probability calculations and statistical measures available to forensic economists.
Dehydration of the stratosphere
Authors: Schoeberl M. R. , Dessler A. E.
Published: August 2011

Abstract. Domain filling, forward trajectory calculations are used to examine the global dehydration processes that control stratospheric water vapor. As with most Lagrangian models of this type, water vapor is instantaneously removed from the parcel to keep the relative humidity (RH) with respect to ice from exceeding saturation or a specified super-saturation value. We also test a simple parameterization of stratospheric convective moistening through ice lofting and the effect of gravity waves as a mechanism that can augment dehydration. Comparing diabatic and kinematic trajectories driven by the MERRA reanalysis, we find that, unlike the results from Liu et al. (2010), the additional transport due to the vertical velocity "noise" in the kinematic calculation creates too dry a stratosphere and a too diffuse a water-vapor tape recorder signal compared observations. We also show that the kinematically driven parcels are more likely to encounter the coldest tropopause temperatures than the diabatic trajectories. The diabatic simulations produce stratospheric water vapor mixing ratios close to that observed by Aura's Microwave Limb Sounder and are consistent with the MERRA tropical tropopause temperature biases. Convective moistening, which will increase stratospheric HDO, also increases stratospheric water vapor while the addition of parameterized gravity waves does the opposite. We find that while the Tropical West Pacific is the dominant dehydration location, but dehydration over Tropical South America is also important. Antarctica makes a small contribution to the overall stratospheric water vapor budget as well by releasing very dry air into the Southern Hemisphere stratosphere following the break up of the winter vortex.
Impacts of aerosols on weather and regional climate over the Pearl River Delta megacity area in China
Authors: Wang Y. , Wan Q. , Meng W. , Liao F. , Tan H. , Zhang R.
Published: August 2011

Abstract. Seven-year measurements of precipitation, lightning flashes, and visibility from 2000 to 2006 have been analyzed in the Pearl River Delta (PRD) region, China, with a focus on the Guangzhou megacity area. Statistical analysis shows that the occurrence of heavy rainfall (>25 mm per day) and frequency of lightning strikes are reversely correlated to visibility during this period. To elucidate the effects of aerosols on cloud processes, precipitation, and lightning activity, a cloud resolving – Weather Research and Forecasting (CR-WRF) model with a two-moment bulk microphysical scheme is employed to simulate a mesoscale convective system occurring on 28 Match 2009 in the Guangzhou megacity area. The model predicted evolutions of composite radar reflectivity and accumulated precipitation are in agreement with measurements from S-band weather radars and automatic gauge stations. The calculated lightning potential index (LPI) exhibits temporal and spatial consistence with lightning flashes recorded by a local lightning detection network. Sensitivity experiments have been performed to reflect aerosol conditions representative of polluted and clean cases. The simulations suggest that precipitation and LPI are enhanced by about 16 % and 50 %, respectively, under the polluted aerosol condition. Our results suggest that elevated aerosol loading suppresses light and moderate precipitation (less than 25 mm per day), but enhances heavy precipitation. The responses of hydrometeors and latent heat release to different aerosol loadings reveal the physical mechanism for the precipitation and lightning enhancement in the Guangzhou megacity area, showing more efficient mixed phase processes and intensified convection under the polluted aerosol condition.
Changes in chemical composition of the middle atmosphere caused by sudden stratospheric warmings as seen by GOMOS/Envisat
Authors: Sofieva V. F. , Kalakoski N. , Verronen P. T. , Salmi S.-M. , Kyrölä E. , Backman L. , Tamminen J.
Published: August 2011

Abstract. Sudden stratospheric warmings (SSW) are large-scale transient events, which have a profound effect on the Northern Hemisphere stratospheric circulation in winter. During the SSW events the temperature in stratosphere increases by several tens of Kelvins and zonal winds decelerate or reverse in direction. Changes in temperature and dynamics significantly affect the chemical composition of the middle atmosphere. In this paper, the response of the middle-atmosphere trace gases during several sudden stratospheric warmings in 2003–2008 is investigated using measurements from the GOMOS (Global Ozone Monitoring by Occultation of Stars) instrument on board the Envisat satellite. We have analyzed spatial and temporal changes of NO2 and NO3 in the stratosphere, and of ozone in the whole middle atmosphere. To facilitate our analyses, we have used the temperature profiles data from the MLS (Microwave Limb Sounder) instrument on board the Aura satellite, as well as simulations by the FinROSE chemistry-transport model and the Sodankylä Ion and Neutral Chemistry model (SIC). NO3 observations in the polar winter stratosphere during SSWs are reported for the first time. Changes in chemical composition are found not to be restricted to the stratosphere, but to extend to mesosphere and lower thermosphere. They often exhibit a complicated structure, because the distribution of trace gases is affected by changes in both chemistry and dynamics. The tertiary ozone maximum in the mesosphere often disappears with the onset of SSW, probably because of strong mixing processes. The strong horizontal mixing with outside-vortex air is well observed also in NO2 data, especially in cases of enhanced NO2 inside the polar vortex before SSW. Almost in all of the considered events, ozone near the secondary maximum decreases with onset of SSW. In both experimental data and FinROSE modelling, ozone changes are positively correlated with temperature changes in the lower stratosphere in the dynamically controlled region below ~35 km, and they are negatively correlated with temperature in the upper stratosphere (altitudes 35–50 km), where chemical processes play a significant role. Large enhancements of stratospheric NO3, which strongly correlate with temperature enhancements, are observed for all SSWs, as expected by the current understanding of temperature-dependence of NO3 concentrations and simulations with the CTM.
Erosion, deposition and replacement of soil organic carbon in Mediterranean catchments: a geomorphological, isotopic and land use change approach
Authors: Nadeu E. , Berhe A. A. , de Vente J. , Boix-Fayos C.
Published: August 2011

Abstract. The assessment of the net effect of soil erosion on the global carbon budget is still incomplete because of lack of enough focused studies and field data. Two of the major gaps on our understanding of the erosion induced terrestrial carbon sink issue include rate of eroded soil organic carbon (OC) replacement by production of new photosynthate and stability of eroded OC post deposition. Here we examine the effect of erosion processes and land use change on the stock, type and stability of OC in two medium-sized subcatchments (18 and 50 ha in size) in SE Spain. We analysed soil samples from drainage areas and depositional settings for stock and isotopic composition of OC (14C and 13C) and particle size distribution. In addition, we conducted land use change analysis for the period 1956–2008 and a geomorphological survey of the current erosion processes taking place in the slope-streambed connections. Our findings demonstrate how land use change influenced the dominating erosion processes and, thus, the source of eroding sediments. Carbon isotopes used as tracers revealed that in one of the subcatchments the deposited sediments derived from deep soil (average Δ14C of −271.5 ‰) through non-selective erosion processes. In the other subcatchment, topsoil material was predominantly eroded and the average Δ14C in sediments was −64.2 ‰. Replacement of eroded soil OC was positive (4 and 11 times-fold losses by erosion) for the analyzed soil profiles in the slopes suggesting that erosion processes do not necessarily provoke a decrease in soil OC stock.
Ventilation changes in the western North Pacific since the last glacial period
Authors: Okazaki Y. , Sagawa T. , Asahi H. , Horikawa K. , Onodera J.
Published: August 2011

Abstract. We reconstructed the ventilation record of deep water at 2100 m depth in the mid-latitude western North Pacific over the past 25 kyr from radiocarbon measurements of coexisting planktic and benthic foraminiferal shells in sediment with a high sedimentation rate. The 14C data on fragile and robust planktic foraminiferal shells were concordant with each other, ensuring high quality of the reconstructed ventilation record. The radiocarbon activity changes were consistent with the atmospheric record, suggesting that no massive mixing of old carbon from the abyssal reservoir occurred throughout the glacial to deglacial periods.
LANL*V2.0: global modeling and validation
Authors: Koller J. , Zaharia S.
Published: August 2011

Abstract. We describe in this paper the new version of LANL*, an artificial neural network (ANN) for calculating the magnetic drift invariant L*. This quantity is used for modeling radiation belt dynamics and for space weather applications. We have implemented the following enhancements in the new version: (1) we have removed the limitation to geosynchronous orbit and the model can now be used for a much larger region. (2) The new version is based on the improved magnetic field model by Tsyganenko and Sitnov (2005) (TS05) instead of the older model by Tsyganenko et al. (2003). We have validated the model and compared our results to L* calculations with the TS05 model based on ephemerides for CRRES, Polar, GPS, a LANL geosynchronous satellite, and a virtual RBSP type orbit. We find that the neural network performs very well for all these orbits with an error typically ΔL* < 0.2 which corresponds to an error of 3 % at geosynchronous orbit. This new LANL* V2.0 artificial neural network is orders of magnitudes faster than traditional numerical field line integration techniques with the TS05 model. It has applications to real-time radiation belt forecasting, analysis of data sets involving decades of satellite of observations, and other problems in space weather.
The within-day behaviour of 6 minute rainfall intensity in Australia
Authors: Western A. W. , Anderson B. , Siriwardena L. , Chiew F. H. S. , Seed A. , Blöschl G.
Published: August 2011

Abstract. The statistical behaviour and distribution of high-resolution (6 min) rainfall intensity within the wet part of rainy days (total rainfall depth >10 mm) is investigated for 42 stations across Australia. This paper compares nine theoretical distribution functions (TDFs) in representing these data. Two goodness-of-fit statistics are reported: the Root Mean Square Error (RMSE) between the fitted and observed within-day distribution; and the coefficient of efficiency for the fit to the highest rainfall intensities (average intensity of the 5 highest intensity intervals) across all days at a site. The three-parameter Generalised Pareto distribution was clearly the best performer. Good results were also obtained from Exponential, Gamma, and two-parameter Generalized Pareto distributions, each of which are two parameter functions, which may be advantageous when predicting parameter values. Results of different fitting methods are compared for different estimation techniques. The behaviour of the statistical properties of the within-day intensity distributions was also investigated and trends with latitude, Köppen climate zone (strongly related to latitude) and daily rainfall amount were identified. The latitudinal trends are likely related to a changing mix of rainfall generation mechanisms across the Australian continent.
Nucleation and growth of geological faults
Authors: Stoyan D. , Gloaguen R.
Published: August 2011

Abstract. We present a new model of fault nucleation and growth based on the Weibull theory, already widely used in fracture research engineering. We propose that, according to a birth-and-growth process, germs (nuclei) are born at random instants at random spatial locations and then grow with time. This leads to a satisfactory formulation of fault length distribution, different from classical statistical laws. Especially, this formulation reconciles previous analyses of fault datasets displaying power-law and/or exponential behaviors. The Weibull parameters can be statistically estimated in a simple way. We show that the model can be successfully fitted to natural data in Kenya and Ethiopia. In contrast to existing descriptive models developed for geological fault systems, such as fractal approaches, the Weibull theory allows to characterize the strength of the material, i.e. its resistance to deformation. Since this model is very general, we expect that it can be applied in many situations, and for simulations of geological fracture processes. The model is independent of deformation intensity and type and therefore allows a better constraint of the seismic risk in threatened regions.
Mapping turbidity currents using seismic oceanography
Authors: Vsemirnova E. A. , Hobbs R. W.
Published: August 2011

Abstract. Using a combination of seismic oceanographic and physical oceanographic data acquired across the Faroe-Shetland Channel we present evidence of a turbidity current that transports suspended sediment along the western boundary of the Channel. We focus on reflections observed on seismic data close to the sea-bed on the Faroese side of the Channel below 900m. Forward modelling based on independent physical oceanographic data show that thermohaline structure does not explain these near sea-bed reflections but they are consistent with optical backscatter data, dry matter concentrations from water samples and from seabed sediment traps. Hence we conclude that an impedance contrast in water column caused by turbidity currents is strong enough to be seen in seismic sections and this provides a new way to visualise this type of current and its lateral structure. By inverting the seismic data we estimate a sediment concentration in the turbidity current, present at the time of the survey, of 45 ± 25 mg l−1. We believe this is the first direct observation of a turbidity current using Seismic Oceanography.
Lathyrus aphaca L.: the distribution, habitats and remarks on the status of the species in Poland
Authors: Nobis Agnieszka , Nobis Marcin , Urbisz Alina
Published: August 2011

Lathyrus aphaca, which is in Poland considered to be an ephemerophyte recorded mainly in the north-west and the south-west, has lately been observed in arable fields in the south of the country. Recent and historical data on the distribution of the taxon in Poland are presented. Original relevés conducted in arable fields in Poland are analysed and compared to those from the Czech Republic, Germany and Slovenia. The current status of L. aphaca in the Polish flora is discussed.
Magnetic Molecularly Imprinted Polymer Nanocomposites via Surface‐Initiated RAFT Polymerization
Authors: Gonzato Carlo , Courty Matthieu , Pasetto Pamela , Haupt Karsten
Published: August 2011

A general protocol to synthesize superparamagnetic molecularly imprinted polymer particles, using a RAFT‐mediated approach, is described. S‐ propranolol‐imprinted composites were obtained by functionalizing commercially available amino‐modified Fe3O4 nanoparticles with a trithiocarbonate agent and subsequently by polymerizing thin molecularly imprinted layers. Different parameters were optimized and their effect on both nanomorphology and imprinting behaviour was studied. Optimum conditions allowed the synthesis of 40 nm composite particles with a 7 nm MIP shell, exhibiting superparamagnetic properties and specific molecular recognition of S‐ propranolol. The possibility of fine‐tuning the surface properties of the particles is demonstrated by using the “living” nature of active RAFT fragments present on the surface of the composites to further functionalize the particles with ethylene glycol methacrylate phosphate polymer brushes.