bluuebunny/crossref_metadata_2025_split huggingface dataset:
Integrated analysis and interpretation of cross‐hole P‐ and S‐wave tomograms: a case study
Authors: Dietrich Peter , Tronicke Jens 
Published: August 2009

ABSTRACTWe present cross‐hole P‐ and S‐wave seismic experiments that have been performed along a ~100 m long transect for the detailed characterization of a contaminated sedimentary site (Bitterfeld research test site, Germany). We invert the corresponding first break arrival times for the P‐ and S‐wave velocity structure and compare two different strategies to interpret these models in terms of pertinent lithological and geotechnical parameter variations. The first (common) approach is based on directly translating the tomographic velocity models into the parameters of interest (e.g., elastic moduli). The second (zonal) approach first reduces the tomographic parameter information to a limited number of characteristic velocity combinations via ‐means cluster analysis. Then, for each zone (cluster) further parameters including uncertainties can be estimated. In the presented case study, our results indicate that the zonal approach provides an effective means for the integrated interpretation of different co‐located data.
GPR investigations to characterize Medieval and Roman foundations under existing shop premises: a case study from Chester, Cheshire, UK
Authors: Pringle J.K. , Lenham J.W. , Reynolds J.M. 
Published: August 2009

ABSTRACTA high‐resolution, ground‐penetrating radar (GPR) investigation was performed on existing commercial shop premises within The Rows, Chester, UK to detect near‐surface features, including a suspected Medieval undercroft (cellar), the location of which was unknown. GPR 2D profiles were acquired on a 0.5 m square grid‐pattern both within the premises and on an exterior, Medieval raised walkway. Multi‐frequency (250, 500 and 800 MHz dominant frequency) repeat‐surveys were acquired in selected areas over the grid to resolve progressively deeper near‐surface structures and used to generate 500 and 800 MHz horizontal ‘time‐slices’.Floor‐supporting wooden beams with steel supports on the exterior walkway, the Medieval undercroft, associated passageways and a hitherto unexpected access trap‐door were all successfully located. The undercroft was found to be air‐filled. Three near‐surface rectangular areas were identified and found not to be associated with the undercroft; these were interpreted to represent heterogeneous, rubble back‐fill. Separate, isolated, raised areas were also identified ~1.5 m below present floor level; these were interpreted as relict brick column supports from a long‐demolished, Roman building. GPR data acquired on the exterior raised walkway also found evidence for relict support structures from a former shopfront.All of the targeted anomalies were intrusively investigated and provided positive confirmation of the geophysical interpretations. Archaeological investigations of trial pits confirmed the site’s varied history and depth to bedrock. GPR was therefore effective in this study to locate and characterize the modern, Medieval and Roman features without extensive intrusive investigation, whilst causing minimal disruption to commercial operations. These results demonstrate the effectiveness of carefully acquired and processed, high‐resolution, closely‐spaced GPR survey data in near‐surface characterization for geotechnical investigations.
Markov random field image processing applications on ruins of the Hittite Empire
Authors: Uçan Osman N. , Muhittin Albora A. 
Published: August 2009

ABSTRACTIn this paper, we applied Markov random field processing to geophysical data as an alternative to classical deterministic approaches. Markov random field processing is an unsupervised statistical model‐based algorithm, which does not requirea prioriinformation. We present a dynamic programming based on evaluation of noisy and superpositioned effects of the various geological structures considering a statisticalmaximum a posterioricriterion. The objective of the proposed modelling is to capture the intrinsic character of the input potential anomaly map in a few parameters, so as to understand the nature of the phenomenon generating the anomaly. In order to decrease processing time and to enhance image performance of the Markov random field, we introduce a preprocessing step. The preprocessing step is crucial and it helps us to solve difficult multi‐disciplinary problems such as separation, enhancement of magnetic anomalies and border detection. We also decrease the noisy peak values of pixels by this smoothing process and emphasize the discontinuity properties of the noisy data by an absolute differentiation procedure. Here, the magnetic field of the input data is considered as a two‐dimensional image with a matrix composed ofpixels. We evaluate each pixel of thematrix using the Markov random field approach, regarding the neighbouring pixels and their locality in real time with noa prioritraining procedure. As synthetic examples, various prism models are considered and the separation and edge detection performance of the Markov random field is tested. As real data, we have evaluated the magnetic anomaly map of the Hittite civilization in the Sivas‐Alt1nyayla region of Turkey. We have obtained satisfactory results in both synthetic and real data and concluded that the Markov random field is a compromising approach for the separation problem of regional‐residual anomalies and edge detection of various geological bodies.
Trends in waterborne electrical and EM induction methods for high resolution sub‐bottom imaging
Authors: Butler Karl E. 
Published: August 2009

ABSTRACTShallow water applications of electrical and electromagnetic geophysical methods have grown in recent years with recognition of the information these methods can provide regarding groundwater‐surface water interaction, geotechnical engineering, exploration, marine geology and other fields. In many applications, spatial variations in resistivity are useful as a proxy for variations in another bulk material property such as pore water salinity, clay content, porosity, or temperature.Applications of galvanic resistivity methods have been buoyed by the development of marine configurations that are now commercially available. In contrast, with two notable exceptions, most applications of EM induction methods have involved experimental adaptations of instruments originally designed for use on land. Methods for shallow water resistivity and EM induction surveys are at an exciting stage of development where several promising applications have been demonstrated but the suite of tools and components commercially available and widely tested remains relatively small.
DC resistivity sensitivity patterns for tilted transversely isotropic media
Authors: Wiese Tim , Greenhalgh Stewart , Marescot Laurent 
Published: August 2009

ABSTRACTIn this paper we present and analyse DC resistivity sensitivity patterns for uniform anisotropic media and for various surface electrode arrays. The sensitivity functions (or Fréchet derivatives) give the responsive change in measured electric potential for a perturbation in a model parameter at a particular point in the subsurface for a specific electrode configuration. The anisotropic model investigated is the common tilted transversely isotropic medium, which is defined by four model parameters. We examine the changes in the Fréchet derivatives of the Green’s functions with respect to both the longitudinal and transverse conductivity and the dip and azimuth angle of the symmetry axis for varying model parameters. Anisotropic sensitivities are vastly different in strength and shape compared to the isotropic sensitivity pattern. The various arrays (pole‐pole, dipole‐dipole, Wenner and square array) produce distinctive patterns that are important in assessing resolution. Valuable insights were gained: the anisotropic Fréchet derivatives can vary greatly from the isotropic pattern in both strength and shape depending on the nature of the anisotropy. Also it was found that the relationship between components of current density (parallel and perpendicular to the symmetry axis) and the sensitivity patterns is somewhat akin to the dot product of the true source and adjoint source current density vectors in isotropic media. Understanding of the anisotropic sensitivity pattern variations will enable, through further analysis, computation of model resolution matrices and improvement of experimental design. Appreciation of the significant differences between isotropic and anisotropic sensitivities should help avoid errors in using inappropriate isotropic inversion schemes to interpret measurements made over anisotropic ground.
Combining airborne electromagnetic induction and hydrochemistry to quantify salinity contributions to a large basin stream, Colorado River, Texas, USA
Authors: Paine Jeffrey G. , Collins Edward W. , Nance H.S. , Niemann Kerry L. 
Published: August 2009

ABSTRACTWe combined multifrequency airborne electromagnetic induction (EM) measurements of apparent ground conductivity with chemical analyses of surface water to delineate natural and oilfield salinity sources that degrade surface water quality by elevating total dissolved solids, chloride and sulphate concentrations along several hundred kilometres of the Colorado River (western Texas, USA). To reduce the cost of airborne geophysical surveying over such large areas, we used a helicopter to tow an EM instrument at low altitude along the stream‐axis and measure the apparent electrical conductivity of the ground at multiple frequencies, examined results in the field to identify salinized stream segments and optimal water sampling locations and then flew more detailed surveys over these limited areas rather than over the entire basin as is typical in salinization studies. Minimally processed stream‐axis EM data (including apparent conductivities measured at single frequencies and multifrequency ‘spectrograms’ along the stream‐axis) helped identify salinized streambed segments, discriminate between surface and subsurface sources of salinity and determine water sampling locations upstream and downstream from each segment. We integrated EM, streamflow and hydrochemical data to calculate salinity loads, identify specific natural and oilfield salinity sources and guide and implement remediation efforts.Stream‐axis flight lines offer the advantage of rapidly acquiring high‐resolution subsurface conductivity data along long stream segments where traditional gridded flight‐line surveys and waterborne measurements are impractical or prohibitively expensive. They also overcome difficulties associated with topographic effects when surveying deeply incised streams. Such surveys provide valuable information on location, extent and type of salinization and can guide water sampling and more intensive ground or airborne measurements.
Continuous electrical imaging for mapping aquifer recharge along reaches of the Namoi River in Australia
Authors: Kelly B.F.J. , Allen D. , Ye K. , Dahlin T. 
Published: August 2009

ABSTRACTIn this study the capacity of towed floating electrical imaging for mapping a known aquifer recharge zone in more detail is investigated. A 50 km reach of the Namoi River, Australia, was surveyed. The river is perched up to 16 m above an unconfined aquifer that extends to 30 m below the ground surface. The unconfined aquifer overlies a semi‐confined aquifer system. The electrical array consists of two current electrodes near the boat, followed by nine potential electrodes. The sequence of 1D electrical sounding curves generated was automatically inverted to obtain a layered earth electrical model along the river to a depth of approximately 40 m. There was weak correlation between the water conductivity measured in boreholes and the layered earth electrical model. Lithological logs from boreholes near the river indicate that the major layers seen in the electrical conductivity cross‐section correspond to the major sedimentary units. Groundwater mounding in the vicinity of the river has been monitored after flooding. The groundwater flood mounds coincide with the location of the predominantly low electrically conductive sediments mapped beneath the river. This suggests that aquifer recharging waters migrate via the sands and gravels, then pool at the water table before dissipating. This survey demonstrates that mapping intervals of low electrically conductive sediments beneath the river maps potential aquifer recharge pathways.
Interaction Trap/Two‐Hybrid System to Identify Interacting Proteins
Authors: Golemis Erica A. , Serebriiskii Ilya , Finley Russell L. , Kolonin (hunt by interaction mating) Mikhail G. , Gyuris Jeno , Brent Roger 
Published: August 2009

AbstractThe yeast two‐hybrid method (or interaction trap) is a powerful technique for detecting protein interactions. The procedure is performed using transcriptional activation of a dual reporter system in yeast to identify interactions between a protein of interest (the bait protein) and the candidate proteins for interaction. The method can be used to screen a protein library for interactions with a bait protein or to test for association between proteins that are expected to interact based on prior evidence. Interaction mating facilitates the screening of a library with multiple bait proteins.Curr. Protoc. Protein Sci. 57:19.2.1‐19.2.35. © 2009 by John Wiley & Sons, Inc.
Strep/FLAG Tandem Affinity Purification (SF‐TAP) to Study Protein Interactions
Authors: Gloeckner Christian Johannes , Boldt Karsten , Ueffing Marius 
Published: August 2009

AbstractIn recent years, several methods have been developed to analyze protein‐protein interactions under native conditions. One of them, tandem affinity purification (TAP), combines two affinity‐purification steps to allow isolation of high‐purity protein complexes. This unit presents a methodological workflow based on an SF‐TAP tag comprising a doublet Strep‐tag II and a FLAG moiety optimized for rapid as well as efficient tandem affinity purification of native proteins and protein complexes in higher eukaryotic cells. Depending on the stringency of purification conditions, SF‐TAP allows both the isolation of a single tagged‐fusion protein of interest and purification of protein complexes under native conditions. Curr. Protoc. Protein Sci. 57:19.20.1‐19.20.19. © 2009 by John Wiley & Sons, Inc.
Genetic and environmental stability differs in reactive and proactive aggression
Authors: Tuvblad Catherine , Raine Adrian , Zheng Mo , Baker Laura A. 
Published: August 2009

AbstractThe aim of this study was to examine stability and change in genetic and environmental influences on reactive (impulsive and affective) and proactive (planned and instrumental) aggression from childhood to early adolescence. The sample was drawn from an ongoing longitudinal twin study of risk factors for antisocial behavior at the University of Southern California (USC). The twins were measured on two occasions: ages 9–10 years (N=1,241) and 11–14 years (N=874). Reactive and proactive aggressive behaviors were rated by parents. The stability in reactive aggression was due to genetic and nonshared environmental influences, whereas the continuity in proactive aggression was primarily genetically mediated. Change in both reactive and proactive aggression between the two occasions was mainly explained by nonshared environmental influences, although some evidence for new genetic variance at the second occasion was found for both forms of aggression. These results suggest that proactive and reactive aggression differ in their genetic and environmental stability, and provide further evidence for some distinction between reactive and proactive forms of aggression. Aggr. Behav. 35:437–452, 2009. © 2009 Wiley‐Liss, Inc.
Recent Progress in GaN‐Based Light‐Emitting Diodes
Authors: Jia Haiqiang , Guo Liwei , Wang Wenxin , Chen Hong 
Published: August 2009

AbstractIn the last few years the GaN‐based white light‐emitting diode (LED) has been remarkable as a commercially available solid‐state light source. To increase the luminescence power, we studied GaN LED epitaxial materials. First, a special maskless V‐grooved c‐plane sapphire was fabricated, a GaN lateral epitaxial overgrowth method on this substrate was developed, and consequently GaN films are obtained with low dislocation densities and an increased light‐emitting efficiency (because of the enhanced reflection from the V‐grooved plane). Furthermore, anomalous tunneling‐assisted carrier transfer in an asymmetrically coupled InGaN/GaN quantum well structure was studied. A new quantum well structure using this effect is designed to enhance the luminescent efficiency of the LED to ∼72%. Finally, a single‐chip phosphor‐free white LED is fabricated, a stable white light is emitted for currents from 20 to 60 mA, which makes the LED chip suitable for lighting applications.
Modeling and simulation of photofabrication processes using unsaturated polyester resins
Authors: Matias João Manuel , Bartolo Paulo Jorge , Pontes António Vilela 
Published: August 2009

AbstractSeveral kinetic models have been proposed to simulate thermosetting cure reactions. The most complex models, based on a mechanistic approach of cure reactions, are developed based on the concepts of free radical polymerization and the mechanism of reactions with diffusion. However, mechanistic models are usually quite impractical for engineering purposes because of the difficulty in obtaining the model parameters. An alternative to these mechanistic models are the phenomenological models, formulated in terms of the degree of cure and much easier to apply. Phenomenological models have been largely used to study thermal‐initiated cure reactions, although only few works used them to model the kinetics of ultraviolet‐initiated cure reaction. This work proposes a photo‐thermal‐kinetic model to study the behavior of unsaturated polyester resins during ultraviolet‐initiated cure reactions. The model considers samples with different amounts of initiator concentration and cure reactions performed under different ultraviolet light intensities. The model has been numerically solved using the finite element technique. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Influence of PP‐g‐MA on morphology, mechanical properties and deformation mechanism of copolypropylene/clay nanocomposite
Authors: Akbari Babak , Bagheri Reza 
Published: August 2009

AbstractCopolypropylene/organoclay nanocomposites are prepared by melt intercalation method in this research. Two different routes for addition of compatibilizer are examined, i.e. addition in the twin‐screw extruder along with the polymer and the clay powder simultaneously and premixing the compatibilizer with the reinforcement in a batch mixer before addition to the polypropylene (PP) matrix. Morphology, tensile and impact properties and deformation mechanisms of the samples made via two procedures are studied and compared with those of the noncompatibilized system. To study the structure of nanocomposites, x‐ray diffraction and transmission electron microscopy techniques are utilized. The deformation mechanisms of different samples are examined via reflected and transmitted optical microscopy. The results reveal that introduction of compatibilizer and also the procedure in which the compatibilizer is added to the compound, affect structure and mechanical properties of nanocomposite. The elastic modulus of PP‐clay nanocomposite has increased 11.5% with incorporation of compatibilizer. Also, introduction of organoclay without compatibilizer facilitates crazing at the notch tip of PP in 3PB testing. Incorporation of compatibilizer, however, makes difficulties in initiation and growth of crazes at the notch tip. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Suppression of breast cancer cells in vitro by polyamidoamine‐dendrimer‐mediated 5‐fluorouracil chemotherapy combined with antisense micro‐RNA 21 gene therapy
Authors: Mei Mei , Ren Yu , Zhou Xuan , Yuan Xu‐Bo , Li Fei , Jiang Ling‐Huo , Kang Chun‐Sheng , Yao Zhi 
Published: August 2009

AbstractA specific micro‐RNA (miRNA), micro‐RNA 21 (miR‐21), is strongly overexpressed in breast cancer cells. Antisense inhibition of miRNA function, an important tool for uncovering miRNA biology, which is often used to knockdown miRNA, can cause a notable inhibition of cell growth. In this study, 5‐fluorouracil (5‐FU) was conjugated to polyamidoamine dendrimers via direct encapsulation; this method was then combined with antisense micro‐RNA 21 (as‐miR‐21) strategies to evaluate the effects of the growth suppression of breast cancer cells. Our results show that as‐miR‐21 strategies significantly improved the chemosensitivity of free 5‐FU on breast cancer cells (MCF‐7). In addition, not only could as‐miR‐21 effectively increase the apoptotic cell numbers but it could also bring down the migration ability of MCF‐7 cells. Our results provide invaluable information for the future design of drug–polymer complexes for multimodal cancer treatments. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
The effects on the properties of PET bottles of changes to bottle‐base geometry
Authors: Demirel B. , Daver F. 
Published: August 2009

AbstractPoly(ethylene terephthalate) (PET) bottles are commonly used for packaging of carbonated beverages. Stress cracking in the petaloid‐shaped base of the filled bottle has been costly to the beverage industry. This study compares the performance of a standard bottle and a bottle with a base geometry optimized against environmental stress cracking (ESC). The crystallinity of the bottle base is evaluated across the base diameter for both bottles. Moreover, to explain the mechanism of the crack formation and propagation, the cracks in the bottle base are investigated through environmental scanning electron microscopy (ESEM) and optical microscopy. Top‐load strength, burst strength, and thermal stability are also reported. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Polyethylene‐collagen hydrolizate thermoplastic blends: Thermal and mechanical properties
Authors: Castiello Domenico , Chiellini Emo , Cinelli Patrizia , D'Antone Salvatore , Puccini Monica , Salvadori Maurizio , Seggiani Maurizia 
Published: August 2009

AbstractCollagen, a natural macromolecular protein from renewable resources, is widely used in many industrial applications. Mixtures of low‐density polyethylene (LDPE) with collagen hydrolizate derived from the tannery industry were investigated to assess the feasibility of producing polymeric materials suitable for production of thermoplastic items for applications in packaging and agricultural segments. Different grades of polyethylenes and collagen hydrolizates characterized by different molecular weight and salinity were investigated to develop optimal blends. The physical–chemical properties of the obtained blends were assessed by thermal–mechanical, spectroscopical analysis. Following the ongoing research activity, the reutilization of collagen hydrolizate derived from the leather industry for the production of environmental degradable polyethylene‐based thermoplastic films appears feasible and promising. Blends of collagen hydrolizate and LDPE up to 20–30 wt % of collagen hydrolizate allow obtaining slightly opaque, cohesive and flexible films that show satisfactory thermal–mechanical responses. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009