bluuebunny/crossref_metadata_2025 huggingface dataset:
Inhibition of Oxygen Reduction on Copper in Neutral Sodium Chloride
Authors: Kendig M. , Hon Melitta , Sinko John
Published: November 2006

Corrosion of high strength aluminum alloys used in aerospace structures depends on the oxygen reduction reaction (ORR) at noble Cu-rich secondary phases in the alloy. Inhibition of the ORR makes a significant impact on limiting the corrosion rate of these materials in neutral chloride environments. Several different types of ORR inhibitors have been compared in terms of adsorbtion and effectiveness in limiting the ORR on a well defined Cu cathode in 0.5 M aerated NaCl.
Drying Effects on Corrosion Properties of Cr(VI)- and Cr(III)- Treated Electrogalvanized Steel
Authors: Zhang Xiaolong , van den Bos Chris , Sloof Wim G. , Hovestad Arjan , Terryn Herman , De Wit J.H.W .
Published: November 2006

Drying effects on corrosion performance of Cr(VI)- and Cr(III)- treated electro-galvanized steel have been studied in NaCl solution using potentiodynamic measurements and electrochemical impedance spectroscopy (EIS). The Cr(VI) and the Cr(III) treated specimens were dried at three different temperatures: 60, 110 and 210{degree sign}C. The surface layers were investigated using SEM, AES and XPS. The results show that the drying temperature not only affects the morphology of the surface layer, but also changes the chromium oxidation states in the layer. The corrosion protection given to the EG steel by Cr(VI) and Cr(III) pretreatments can be severely reduced if the pretreated surfaces are heated above 110{degree sign}C. Both types of coating undergo some dehydration during heat treatments, which is undesirable for good corrosion protection. For Cr(VI) coatings, additional degradation mechanisms include widening of the cracks in the coating, and reduction of Cr(VI) to the Cr (III) oxidation state.
An Electrochemical Impedance Study on the Influence of Flow on the Corrosion Inhibition of Carbon Steel by Fatty Amines in Association with Phosphonocarboxylic Acid Salts
Authors: Pebere Nadine , Ochoa Nathalie , Tribollet Bernard
Published: November 2006

This work is an extension of studies into the mechanism of inhibition of a carbon steel in a 200 mg l-1 NaCl solution by a non-toxic multicomponent inhibitor used for the treatment of water in cooling circuits. The inhibitive formulation was composed of 50 mg l-1 fatty amines associated with 200 mg l-1 phosphonocarboxylic acid salts. The influence of flow was investigated by electrochemical impedance spectroscopy with a rotating disc electrode. The results were dependent on the experimental protocols used. The properties of the protective layers were dependent on the electrode rotation rate. The presence of two layers on the electrode surface with protective properties that depend on the electrode rotation rate allowed the non-monotonic variation of the corrosion current densities to be explained. This behavior was related to the influence of flow on the anodic kinetics.
Relative Inhibitors Efficiencies in Systems Containing Stainless Steels
Authors: Ilevbare G. O. , Burstein G.T.
Published: November 2006

A study of selected inhibitors on the inhibition of pitting corrosion in stainless steels 304 and 316 has been undertaken using both macroelectrodes and microelectrodes. Electrolytes contained [Cl-] of 0.1 M Cl- with 0.01 M concentration of inhibitor. Results showed that generally, total number of nucleation and metastable pits had an inverse relationship with the stable pitting potential of stainless steel.
Corrosion Inhibition of Carbon Steel in CO2-Saturated Brine by Phosphate Monoester
Authors: Devine Thomas M. , Chou Peter
Published: November 2006

The inhibition of carbon steel's corrosion in CO2-saturated brine with 300 ppm of phosphate ester, was investigated by a combination of potentiodynamic polarization tests and in situ surface enhanced Raman spectroscopy. The cathodic polarization behavior was unaffected by the phosphate ester, but the anodic polarization curve was lowered by a factor of 10 to 100. At sufficiently high potentials the steel suffered significant pitting corrosion in the inhibited electrolyte. The results suggest that the phosphate ester bonds to the steel's scale rather than to bare steel
The Evolution of Surface Roughness of Copper Electrodeposition Directly on Ultra-Thin Air Exposed TaN Layers
Authors: Lay Nicole , Duquette David
Published: November 2006

Surface roughness of both seed layers and electrodeposited copper for ULSI interconnects affect adhesion and fracture characteristics of the electrodeposited plate. In this program experiments were performed on copper, deposited from complexing citrate baths, directly onto TaN barrier layers, as a function of copper thickness (as measured by plating time) and subsequent annealing. It has been shown that surface roughness increase with increasing plate thickness, reaching a constant roughness at a thickness of about 350 nm. Annealing, in order to enhance plate resistivity, has no appreciable effect on surface roughness.
Electrical Properties of Organic and Silicon Carbide Etch Stop Layers in Copper/Porous MSQ Structures
Authors: Smith Gregory C. , McGowan Richard , Hosali Sharath , Smith Larry , Pfeifer Klaus
Published: November 2006

Dual damascene structures were formed and tested at various trench depths on 300 mm wafers in order to compare etch stop layers of silicon carbide and an organic polymer material with a dielectric constant of 3.2. The metal 2 trenches were filled with Ta and Cu, inlaid and tested at various stages of etch. It has been reported [1] that while damascene structures made with this etch stop material realized reductions in Keff, they exhibited lower intralevel breakdown voltage. The organic etch stop layer exhibited more leakage current as the trenches landed than did the SiC. Ramped voltage breakdown results were similar for the SiC and organic layers except at the tighter pitch and the longest over etch. TDDB lifetimes at 300oC and 1.3 MV/cm were ranked unlanded>SiC etch stop>organic etch stop.
Degradation of Cu/Ta-N/Ta/Low-k Structure via Outgassing of Low-k Dielectrics
Authors: Chen Jen-Sue , Chang Ching-Chun , JangJian Shiu-Ko , Lai Yi-Sheng
Published: November 2006

In this work, the effects of thermal treatment on the materials characteristics of Cu/Ta-N/Ta/low-k material/ structures are explored, where Ta-N layers are as-deposited amorphous TaNx (x~0.5) or polycrystalline TaN films and low-k materials include fluorinated silicate glass (FSG) and organosilicate glass (OSG). The thermal stability of the multilayered structures are examined by annealing the samples in a vacuum furnace at 400 oC for 30 or 60 min and investigated by using scanning electron microscopy, thermal desorption spectroscopy, Fourier transform infrared spectrometer, and X-ray photoelectron spectrometry. The cross- sectional images of the specimens show that delamination of the metallization layers can be eliminated by baking the dielectrics prior to the deposition of metallization layers. Furthermore, the experimental results indicate that not only water absorption but also fluorine gas outgassing should be the serious drawbacks of FSG in applications. Meanwhile, TaN is a more effective barrier to prevent Ta from interacting with FSG and Cu from diffusing than TaNx(x~0.5) is. On the other hand, for the OSG, it possesses an evidently better thermal stability as compared with FSG. The interfacial reactions between the Ta-N/Ta bi-layer and low-k materials, which degrade the devices, will be discussed in this study, too.
Development of Electrochemical Mechanical Polishing for Advanced Copper Planarization
Authors: Jia Renhe , Wang You , Wang Zhihong , Tsai Stan , Diao Jie , Mao Daxin , Karuppiah Laksh , Chen Liang-Yuh
Published: November 2006

Incorporation of low-k materials in advanced metallization calls for novel planarization technology to avoid delamination and improve defect performance. Electrochemical mechanical polishing (EcmpTM) uses electrical voltage as the main driving force for Cu removal, enabling low down force operation that is needed when polish fragile low-k materials. Previously reported Ecmp results discussed the bulk Cu removal step. We now have developed the Ecmp process on the Cu residue clearance step. Therefore, low down force can be applied during the entire Cu removal process, as required when the industry moves to low-k dielectric materials. In addition, due to specific formulation of the consumables used in the process, Ecmp will lead to reduced dishing and erosion, as well as improved surface finish. This paper is focused on the copper clearance step. Chemistry development is key for Ecmp to reduce dishing and maintain good surface finish. The basic principle of Ecmp and the behaviors of some electrolyte will be discussed. It was found that the dishing performance is closely related to the pH of the electrolyte used.
Fabrication of Deep Sub-lithographic Al-Based Nanointerconnects Utilizing a Wet Chemical Hard Mask Trim Process
Authors: Engelhardt Manfred , Steinlesberger Gernot , Kirchner Udo
Published: November 2006

A wet chemical trim of the SiO2 hard mask used for reactive ion etching of Al was developed to fabricate Al-based interconnects with line widths below those in today's most advanced semiconductor products. The electrical characterization of such narrow interconnects was done for a comparison with the data available for Cu Damascene interconnects with deep sub-100nm CDs. For very tight CDs very high electrical resistivities were obtained due to imperfect processing of Al. A fit of the combined compact model for size effects in Al to the experimental data obtained for CDs where process imperfections were not observed, allows an assessment of the expected increase of electrical resistivity of Al due to size effects for very tight feature sizes. The comparison of the data of Al- based interconnects fabricated with RIE using the trimmed SiO2 hard mask with Cu Damascene interconnects suggests a cross-over of electrical resistivities for CDs around 20nm.
Electrografting, A Unique Wet Technology for Seed and Direct Plating in Copper Metallization
Authors: Gonzalez Jose , Raynal Frédéric , Monchoix Hervé , Ben Hamida Abdeslem , Daviot Jerome , Rabinzohn Patrick , Bureau Christophe
Published: November 2006

This paper introduces a novel electrochemical technology called electrografting (eG{trade mark, serif}). After describing electrografting the main characteristics, it will be shown that this technology can be successfully applied to the formation of thin, conformal, and uniform seed layers for IC copper interconnects. Seed layer thicknesses down to 10nm thick are deposited on various copper diffusion barrier materials and characterized in terms of sheet resistance, morphology, conformality, adhesion, and gapfilling capability. Initial results pointed out that the technology can be extended to seedless direct filling of interconnect structures.
Control of Edge Shape, Sidewall Profile, and Sidewall Roughness of the Plasma Etched Copper
Authors: Kuo Yue , Liu Guojun
Published: November 2006

A novel plasma-based, room-temperature copper etching method was reported recently. In this paper, the authors investigated the influence of process parameters on the edge shape, sidewall profile and the sidewall roughness of the etched copper patterns. The additive gas, such as CF4 and N2, affects not only the etch rate but also the sidewall profile. With the proper plasma condition, such as power, pressure, and additive gas, copper lines with a vertical profile and smooth sidewall surface were obtained.
Ethnic and Gender Differences in Ambulatory Blood Pressure Trajectories
Authors: Wang Xiaoling , Poole Joseph C. , Treiber Frank A. , Harshfield Gregory A. , Hanevold Coral D. , Snieder Harold
Published: November 2006

Background—

Cross-sectional studies demonstrated ethnic and gender differences in ambulatory blood pressure patterns, but little is known about the longitudinal development of these differences.

Methods and Results—

Twenty-four-hour ambulatory blood pressure was measured up to 12 times (5 times on average) over a 15-year period in 312 African Americans (AAs) and 351 European Americans aged 7 to 30 years. Multivariate individual growth curves across age were created for daytime and nighttime blood pressure jointly. For both daytime and nighttime systolic blood pressure (SBP), AAs and males had higher levels (
P
<0.001) than European Americans and females. Males also showed a greater increase with age (
P
<0.001) than females. For nighttime SBP, a faster increase of SBP with age (
P
<0.01) in AAs was additionally observed. The ethnic difference in nighttime SBP levels and its increase with age were significantly larger than in daytime SBP. For daytime and nighttime diastolic blood pressure, AAs had higher levels than European Americans (
P
<0.001), and this difference was significantly larger at night. From late adolescence onward, males showed a greater increase in diastolic blood pressure with age than females. Ethnic and gender differences persisted after adjustment for height, body mass index, socioeconomic status, and stress-related coping styles. Family history of essential hypertension explained ethnic differences in daytime SBP.

Conclusions—

We observed significant ethnic and gender differences in longitudinal trajectories of ambulatory blood pressure in youth and young adults. The blunted nocturnal decline and its exacerbation with age in AAs corroborate and extend findings of cross-sectional studies.
Alcohol Consumption and Risk of Heart Failure in the Physicians’ Health Study I
Authors: Djoussé Luc , Gaziano J. Michael
Published: November 2006

Background—

Heart failure (HF) is the leading cause of hospitalization among the elderly, and 1 in 5 adults aged 40 years will develop HF in their lifetime. Data on the effects of moderate alcohol consumption on the risk of HF have been sparse and inconsistent. This study sought to evaluate the association between moderate alcohol consumption and incident HF.

Methods and Results—

A total of 21 601 participants of the Physicians’ Health Study I who were free of HF and provided data on alcohol intake at baseline were prospectively followed up from 1982 to 2005. Incident HF cases were ascertained through annual follow-up questionnaires and validated with the use of Framingham criteria. During an average follow-up of 18.4 years, 904 incident cases of HF occurred. The crude incidence rates of HF were 25.0, 20.0, 24.3, and 20.6 cases per 10 000 person-years for alcohol categories of <1, 1 to 4, 5 to 7, and >7 drinks per week, respectively. Corresponding hazard ratios (95% CI) were 1.0 (reference), 0.90 (0.76 to 1.07), 0.84 (0.71 to 0.99), and 0.62 (0.41 to 0.96), respectively, with
P
for trend=0.012 adjusted for age, body mass index, smoking, and history of valvular heart disease. There was no evidence for a strong association between moderate alcohol consumption and HF without antecedent coronary artery disease.

Conclusions—

Although heavy drinking should be discouraged, our data indicate that moderate drinking may lower the risk of HF. The lack of an association between moderate alcohol intake and HF without antecedent coronary artery disease suggests that possible benefits of moderate drinking on HF may be mediated through beneficial effects of alcohol on coronary artery disease.
Anatomical Substrates of Visual and Auditory Miniature Second-language Learning
Authors: Newman-Norlund Roger D. , Frey Scott H. , Petitto Laura-Ann , Grafton Scott T.
Published: November 2006

Longitudinal changes in brain activity during second language (L2) acquisition of a miniature finite-state grammar, named Wernickese, were identified with functional magnetic resonance imaging (fMRI). Participants learned either a visual sign language form or an auditory-verbal form to equivalent proficiency levels. Brain activity during sentence comprehension while hearing/viewing stimuli was assessed at low, medium, and high levels of proficiency in three separate fMRI sessions. Activation in the left inferior frontal gyrus (Broca's area) correlated positively with improving L2 proficiency, whereas activity in the right-hemisphere (RH) homologue was negatively correlated for both auditory and visual forms of the language. Activity in sequence learning areas including the premotor cortex and putamen also correlated with L2 proficiency. Modality-specific differences in the blood oxygenation level-dependent signal accompanying L2 acquisition were localized to the planum temporale (PT). Participants learning the auditory form exhibited decreasing reliance on bilateral PT sites across sessions. In the visual form, bilateral PT sites increased in activity between Session 1 and Session 2, then decreased in left PT activity from Session 2 to Session 3. Comparison of L2 laterality (as compared to L1 laterality) in auditory and visual groups failed to demonstrate greater RH lateralization for the visual versus auditory L2. These data establish a common role for Broca's area in language acquisition irrespective of the perceptual form of the language and suggest that L2s are processed similar to first languages even when learned after the “critical period.” The right frontal cortex was not preferentially recruited by visual language after accounting for phonetic/structural complexity and performance.
The Impact of Proficiency on Syntactic Second-language Processing of German and Italian: Evidence from Event-related Potentials
Authors: Rossi Sonja , Gugler Manfred F. , Friederici Angela D. , Hahne Anja
Published: November 2006

The present study investigated the role of proficiency in late second-language (L2) processing using comparable stimuli in German and Italian. Both sets of stimuli consisted of simple active sentences including a word category violation, a morphosyntactic agreement violation, or a combination of the two. Four experiments were conducted to study high- and low-proficiency L2 learners of German as well as high- and low-proficiency L2 learners of Italian. High-proficiency L2 learners in both languages showed the same event-related potential (ERP) components as native speakers for all syntactic violations. For the word category violation, they displayed an early anterior negativity (ELAN), an additional negativity reflecting reference-related processes, and a late P600 evidencing processes of reanalysis. For the processing of the morphosyntactic error, an anterior negativity (LAN) and a P600 were observed, whereas for the combined violation, the same ERP components were found as in the pure category violation. In high-proficiency L2 learners, the timing of the processing steps was equivalent to that of native speakers, although some amplitude differences were present. Low-proficiency L2 learners, however, showed qualitative differences in the agreement violation characterized by the absence of the LAN and quantitative differences reflected in a delayed P600 in every violation condition. These findings emphasize that with a high proficiency, late L2 learners can indeed show native-like neural responses with the timing approximating that of native speakers. This challenges the idea that there are fundamental differences in language processing in the brain between natives and late L2 learners.
Time Course of Brain Activity during Change Blindness and Change Awareness: Performance is Predicted by Neural Events before Change Onset
Authors: Pourtois Gilles , De Pretto Michael , Hauert Claude-Alain , Vuilleumier Patrik
Published: November 2006

People often remain “blind” to visual changes occurring during a brief interruption of the display. The processing stages responsible for such failure remain unresolved. We used event-related potentials to determine the time course of brain activity during conscious change detection versus change blindness. Participants saw two successive visual displays, each with two faces, and reported whether one of the faces changed between the first and second displays. Relative to blindness, change detection was associated with a distinct pattern of neural activity at several successive processing stages, including an enhanced occipital P1 response and a sustained frontal activity (CNV-like potential) after the first display, before the change itself. The amplitude of the N170 and P3 responses after the second visual display were also modulated by awareness of the face change. Furthermore, a unique topography of event-related potential activity was observed during correct change and correct no-change reports, but not during blindness, with a recurrent time course in the stimulus sequence and simultaneous sources in the parietal and temporo-occipital cortex. These results indicate that awareness of visual changes may depend on the attentional state subserved by coordinated neural activity in a distributed network, before the onset of the change itself.
When Gaze Turns into Grasp
Authors: Pierno Andrea C. , Becchio Cristina , Wall Matthew B. , Smith Andrew T. , Turella Luca , Castiello Umberto
Published: November 2006

Previous research has provided evidence for a neural system underlying the observation of another person's hand actions. Is the neural system involved in this capacity also important in inferring another person's motor intentions toward an object from their eye gaze? In real-life situations, humans use eye movements to catch and direct the attention of others, often without any accompanying hand movements or speech. In an event-related functional magnetic resonance imaging study, subjects observed videos showing a human model either grasping a target object (grasping condition) or simply gazing (gaze condition) at the same object. These two conditions were contrasted with each other and against a control condition in which the human model was standing behind the object without performing any gazing or grasping action. The results revealed activations within the dorsal premotor cortex, the inferior frontal gyrus, the inferior parietal lobule, and the superior temporal sulcus in both “grasping” and “gaze” conditions. These findings suggest that signaling the presence of an object through gaze elicits in an observer a similar neural response to that elicited by the observation of a reach-to-grasp action performed on the same object.
Precursors of Insight in Event-related Brain Potentials
Authors: Lang Simone , Kanngieser Nadine , Jaśkowski Piotr , Haider Hilde , Rose Michael , Verleger Rolf
Published: November 2006

Event-related potentials (ERPs) were investigated to find precursors of insightful behavior. Participants had to process successive pairs in strings of digits to obtain a final response in each trial. Within the sequence of five responses required in each trial, the last two responses mirrored the two preceding ones. This hidden regularity, allowing for shortcutting each trial from five to two responses, was discovered by 6 out of 26 participants. Both groups, solvers and nonsolvers, implicitly learned the regularity, reflected by faster responses to the repeated, predictable responses, but this differential effect was larger in solvers, whereas nonsolvers became unspecifically faster with all responses. Several ERP components were larger in solvers than in nonsolvers from the outset: slow positive wave, frontocentral P3a, anterior N1 to those digits that triggered the critical repeating responses, and P3b to the digit that evoked the immediately repeating response. Being already present in the first block, these effects were early precursors of insightful behavior. This early occurrence suggests that participants who will gain insight may be distinguished beforehand by their individual characteristics.
Blue Grass Music and Ant-Steps
Authors: Watson Chris
Published: November 2006

Insect chorus track from down amongst the Blue Grass of Kentucky.
Sonic Postcards
Authors: Laurence Becca
Published: November 2006

Sonic Postcard 1: From Chelsea Children's Hospital School, London, created by the pupils from the Collingham Gardens site, facilitated by Jo Lucas. Sonic Postcard 2: From Ashcott Primary School, Somerset, created by Sophie Hunt-Davison and Victoria Langford, facilitated by Tony Whitehead. Sonic Postcard 3: From Market Place Primary School, Aberdeenshire, created by class P6, facilitated by Pippa Murphy.
A Daytime Complement to the Reverse Absorption Technique for Improved Automated Detection of Volcanic Ash
Authors: Pavolonis Michael J. , Feltz Wayne F. , Heidinger Andrew K. , Gallina Gregory M.
Published: November 2006

An automated volcanic cloud detection algorithm that utilizes four spectral channels (0.65, 3.75, 11, and 12 μm) that are common among several satellite-based instruments is presented. The new algorithm is physically based and globally applicable and can provide quick information on the horizontal location of volcanic clouds that can be used to improve real-time ash hazard assessments. It can also provide needed input into volcanic cloud optical depth and particle size retrieval algorithms, the products of which can help improve ash dispersion forecasts. The results of this new four-channel algorithm for several scenes were compared to a threshold-based reverse absorption algorithm, where the reverse absorption algorithm is used to identify measurements with a negative 11–12-μm brightness temperature difference. The results indicate that the new four-channel algorithm is not only more sensitive to the presence of volcanic clouds but also generally less prone to false alarms than the standard reverse absorption algorithm. The greatest impact on detection sensitivity is seen in the Tropics, where water vapor can often mask the reverse absorption signal. The four-channel algorithm was able to detect volcanic clouds even when the 11–12-μm brightness temperature difference was greater than +2 K. In the higher latitudes, the greatest impact seen was the significant reduction in false alarms compared to the reverse absorption algorithm and the improved ability to detect optically thick volcanic clouds. Cloud water can also mask the reverse absorption signal. The four-channel algorithm was shown to be more sensitive to volcanic clouds that have a water (ice or liquid water) component than the reverse absorption algorithm.
The 2D-S (Stereo) Probe: Design and Preliminary Tests of a New Airborne, High-Speed, High-Resolution Particle Imaging Probe
Authors: Lawson R. Paul , O’Connor Darren , Zmarzly Patrick , Weaver Kim , Baker Brad , Mo Qixu , Jonsson Haflidi
Published: November 2006

The design, laboratory calibrations, and flight tests of a new optical imaging instrument, the two-dimensional stereo (2D-S) probe, are presented. Two orthogonal laser beams cross in the middle of the sample volume. Custom, high-speed, 128-photodiode linear arrays and electronics produce shadowgraph images with true 10-μm pixel resolution at aircraft speeds up to 250 m s−1. An overlap region is defined by the two laser beams, improving the sample volume boundaries and sizing of small (<∼100 μm) particles, compared to conventional optical array probes. The stereo views of particles in the overlap region can also improve determination of three-dimensional properties of some particles.

Data collected by three research aircraft are examined and discussed. The 2D-S sees fine details of ice crystals and small water drops coexisting in mixed-phase cloud. Measurements in warm cumuli collected by the NCAR C-130 during the Rain in Cumulus over the Ocean (RICO) project provide a test bed to compare the 2D-S with 2D cloud (2D-C) and 260X probes. The 2D-S sees thousands of cloud drops <∼150 μm when the 2D-C and 260X probes see few or none. The data suggest that particle images and size distributions ranging from 25 to ∼150 μm and collected at airspeeds >100 m s−1 by the 2D-C and 260X probes are probably (erroneously) generated from out-of-focus particles. Development of the 2D-S is in its infancy, and much work needs to be done to quantify its performance and generate software to analyze data.
Considerations on Open Boundary Conditions for Regional and Coastal Ocean Models
Authors: Marsaleix P. , Auclair F. , Estournel C.
Published: November 2006

This paper reviews the usual open boundary conditions (OBCs) for coastal ocean models and proposes a complete set of open boundaries based on stability criteria, on mass and energy conservation arguments, and on the ability to enforce external information. This set includes a radiation condition for barotropic variables, an equation of wave propagation for baroclinic velocities, and an advection equation for tracers. Considerations on mass and energy conservation properties suggest a suitable numerical treatment of the barotropic scheme, which is different from what is commonly used. Restoring terms, when classically added in the Sommerfeld OBCs, are not consistent with external fields. It is shown that this can be avoided if proper numerical schemes are used or if OBCs are applied on differences between the model and forcing rather than on absolute variables. Finally, this paper shows that simplistic advection-type methods for temperature and salinity should not be used in sigma coordinate models because this introduces errors in the computation of the horizontal pressure gradient.
Comparison of Observed and Modeled Drifter Trajectories in Coastal Regions: An Improvement through Adjustments for Observed Drifter Slip and Errors in Wind Fields
Authors: Edwards K. P. , Werner F. E. , Blanton B. O.
Published: November 2006

Lagrangian particle tracking using three-dimensional (3D) numerical modeling approaches has become an important tool in coastal oceanography. In this note, an approach is described that can reduce the difference between observed and numerical drifter trajectories in the coastal ocean by including corrections to the water velocity due to differences between observed winds and the wind field used to drive the 3D circulation model and some specific characteristics of the observed drifters in the algorithm that estimate the numerical trajectory. Quantitative improvements are obtained whereby the separation distance between the numerical and observed drifters is almost halved (in this particular field case from 2.6 to 1.4 km day−1).
High-Altitude Cloud Effects on Airborne Electro-Optical Sensor Performance
Authors: Chervet Patrick , Roblin Antoine
Published: November 2006

A modeling approach is proposed to predict the impact of high-altitude clouds on the detection performance of an airborne electro-optical surveillance sensor. The sensor is dedicated to target detection, and it may be disturbed by cloud presence along the line of sight. The targets are supposed to be dim artificial sources in the atmosphere or stars, and the viewing conditions lead to lines of sight close to horizontal paths. The model is suitable to determine sensor performance for various locations in the earth’s atmosphere and for different seasons. It is based on cloud statistics data determined by the inversion of NOAA satellite observations. Computations of clear line-of-sight probabilities are based on geometric and statistical approaches, and the major hypothesis used here is that all clouds can be considered opaque. Seasonal and diurnal/nocturnal cloud cover variations strongly change the probability of a clear line of sight for a fixed viewing geometry, and the maximal range without clouds that can be reached for a fixed viewing angle and a fixed observer altitude has large temporal variations. These results can be used to reduce the sensor’s field of view to a line of sight having a sufficiently high probability of being cloud free.
Rainfall Profiling Using Atmospheric Radiation Measurement Program Vertically Pointing 8-mm Wavelength Radars
Authors: Matrosov Sergey Y. , May Peter T. , Shupe Matthew D.
Published: November 2006

An attenuation-based method to retrieve vertical profiles of rainfall rate from vertically pointing Ka-band radar measurements has been refined and adjusted for use with the U.S. Department of Energy’s cloud radars deployed at multiple Atmospheric Radiation Program (ARM) test bed sites. This method takes advantage of the linear relationship between the rainfall rate and the attenuation coefficient, and can account for a priori information about the vertical profile of nonattenuated reflectivity. The retrieval method is applied to a wide variety of rainfall events observed at different ARM sites ranging from stratiform events with low-to-moderate rainfall rates (∼5 mm h−1) to heavy convective rains with rainfall rates approaching 100 mm h−1. The Ka-band attenuation-based retrieval results expressed in both instantaneous rainfall rates and in rainfall accumulations are compared to available surface data and measurements of a scanning C-band precipitation polarimetric radar located near the Darwin, Australia, ARM test bed site. The Ka-band retrievals are found to be in good agreement with the C-band radar estimates, which are based both on conventional radar reflectivity approaches and on polarimetric differential phase shift measurements. Typically, the C-band–Ka-band radar estimate differences are within the expected retrieval uncertainties. The magnitude of the Ka-band rainfall-rate estimate error depends on the retrieval resolution, rain intensity, and uncertainties in the profiles of nonattenuated reflectivity. It is shown that reasonable retrieval accuracies (∼15%–40%) can be achieved for a large dynamic range of observed rainfall rates (4–100 mm h−1) and the effective vertical resolution of about 1 km. The potential enhancements of the Ka-band attenuation-based method by including a priori information on vertical profiles of nonattenuated reflectivity and increasing the height range of the retrievals by using Ka-band polarization measurements are also discussed. The addition of the precipitation products to the suite of ARM hydrometeor retrievals can enhance the overall characterization of the vertical atmospheric column.
Generally Cylindrical Orthotropic Constitutive Properties Modeling of Matrix-filled Single-walled Nanotubes: Axial Mechanical Properties
Authors: Kalamkarov Alexander L. , Askari Davood , Veedu Vinod P. , Ghasemi-Nejhad Mehrdad N.
Published: November 2006

The technology of filling hollow carbon nanotubes with desirable materials has created tremendous interest in recent years. The objective of this study is to introduce analytical solutions for effective longitudinal Young's modulus and major Poisson's ratio of matrix-filled single-walled nanotubes (SWNTs). In this work, both SWNT and its filler material are considered generally cylindrical orthotropic. Analytical solutions are obtained and accordingly reduced to transversely isotropic as well as isotropic cases for both tube and filler materials, and then the results are compared with the existing solutions. For further validation, a 3-D model of a matrix-filled single-walled carbon nanotube (SWCNT) is generated and solved for displacement and strain results numerically, using the finite element method. The finite element numerical analysis is employed to verify the accuracy of the results obtained from the analytical approach for generally cylindrical orthotropic materials. Excellent agreement is achieved between the results obtained from the analytical and numerical methods. Furthermore, a parametric study is also conducted to investigate the effective properties variations of the matrix-filled nanotubes based on the variations of nanotube/filler geometry and material properties.
Cement Composites Reinforced with Surface Modified Coir Fibers
Authors: Li Zhijian , Wang Lijing , Ai Wang Xung
Published: November 2006

An experimental investigation of coir mesh reinforced mortar (CMRM) is conducted using nonwoven coir mesh matting. The main parameters in this study are the fiber volume fraction (number of mesh layers) and fiber surface treatment with a wetting agent. The composites are subjected to the four-point bending test. The short-term mechanical properties of CMRM are discussed. Scanning electron micrograph analysis is used to observe the fiber—matrix interfacial characteristics. The results indicate that the addition of coir mesh to mortar significantly improves the composite post-cracking flexural stress, toughness, ductility, and toughness index, compared to plain mortar materials. The Albatex © FFC wetting agent (2-ethylhexanol) can effectively improve water absorption of coir fiber and enhance the fiber—matrix bonding strength. These coir mesh reinforced composites may be useful in civil engineering applications.
An Analysis of Assessment and Intervention Frameworks in Educational Psychology Services in Scotland
Authors: Kennedy Hilary
Published: November 2006

This article describes the main findings of a follow-up survey of assessment and intervention models (current frameworks and future aspirations) used by Scottish Psychological Services that offer placements to Educational Psychologists in Training from the Dundee MSc in Educational Psychology from 1996–2005. This survey led to a study where questionnaires, interviews, debates, national conference workshops involving Educational Psychologists in Training (EPITs) and Educational Psychologists (EPs) in Scotland were used to examine assessment and intervention models. The results show a marked shift in theoretical bases during the period studied from a Cognitive/developmental, Social learning theory base towards a stronger Social Interactionist and Ecological/systemic base. The frameworks current in 1997 and 2002 showed clearly how Educational Psychology Services are moving towards more solution-focused, systemic, naturalistic and collaborative assessments. In all these areas they have surpassed their 1997 aspirations. However, there has been very little change in the use of norm-referenced assessments which perhaps explains why Dynamic (interactive) assessment is not as well established as had been hoped in 1997. The author proposes a new paradigm based on ‘intersubjectivity’ as a unifying foundation for current EP practice.
Academic Correlates of Children and Adolescents' Life Satisfaction
Authors: Suldo Shannon M. , Riley Kristen N. , Shaffer Emily J.
Published: November 2006

Educators and psychologists alike have trumpeted calls for a reduced focus on deficits and pathology and increased attention to strengths and general wellness in all children. Life satisfaction is one of the most well-established indicators of general wellness and, moreover, positive functioning. Most examinations of children's life satisfaction have examined the role of family relations and intrapersonal variables. Studies of life satisfaction in relation to schooling are less prevalent, despite the extraordinary focus on education during this developmental period. Initial studies have examined the extent to which a few categories of school-related factors (school climate, intelligence and ability grouping at school, academic achievement and overall appraisals of one's happiness with school) are correlated with students' life satisfaction. Notably, most empirical examinations have examined one or few school-related factors in isolation. The purpose of the current article is to provide a comprehensive summary of the multiple school-related correlates of life satisfaction through a thorough review of the literature. Implications of the literature base for educators and future research are discussed.
Hopelessness and Loneliness Among Suicide Attempters in School-Based Samples of Taiwanese, Philippine and Thai Adolescents
Authors: Page Randy M. , Yanagishita Jun , Suwanteerangkul Jiraporn , Zarco Emilia Patricia , Mei-Lee Ching , Miao Nae-Fang
Published: November 2006

The aim of this study was to assess the level of suicide attempts in three school-based samples of Southeast Asian adolescents (Taipei, Taiwan; the Philippines; Chiang Mai, Thailand) and determine whether adolescent suicide attempters score higher on measures of hopelessness and loneliness relative to nonattempters. It was hypothesized that hopelessness and loneliness would be related to suicide attempts, and that hopelessness would continue to be associated with suicide attempts when controlling for loneliness. The prevalence of suicide attempts across the three samples of Asian youth were not consistent with Taiwanese girls and boys as the most likely to have ever attempted suicide. As expected, results showed that suicide attempters (in past 12 months and ever) scored higher on hopelessness and loneliness than nonattempters across all three samples and for both genders. However, the statistical control of loneliness demonstrably weakened the association between suicide attempt behaviour and hopelessness across the samples and for both genders, and resulted in nonsignificant ANCOVA tests for some of the sample-gender groups. These results attest to the need for more research investigating connections between youth suicide attempts, hopelessness and loneliness in adolescent populations. Loneliness should be included as a potential determinant of youth suicidal behaviour in future research.
Sex and Age Differences in Self-Reported Distress Among Affluent Adolescents in an Educational Counselling Setting in the United States
Authors: Zand Debra H. , Gouwens Donald L. , Evenson Richard C.
Published: November 2006

This study investigated the most strongly endorsed problems for a group of affluent suburban girls ( n = 58) and boys ( n = 148), between ages 13 to 18, who were referred for educational counselling in the United States. Considerable overlap existed for male and female adolescents with regard to their most frequently reported problems, with boys and girls reporting seven common endorsements. Of particular interest was the prominence of items related to depression, compulsivity and achievement. Girls tended to report more depressive symptoms, whereas boys tended to report more symptoms related to compulsivity and achievement. Additionally, a significantage by sex interaction emerged for items related to achievement issues. Implications of these results for working with youth in cross-national educational counselling settings are discussed.
Sexuality, Power and Resistance in the Workplace
Authors: Fleming Peter
Published: November 2006

This paper investigates whether the expression of sexuality in organizations represents an opportunity for employee resistance or increased management control. It draws upon an empirical study of a high-commitment culture programme that encouraged both heterosexual and homosexual discourses. The study reveals a complex scenario in which sexuality is simultaneously a facet of control, a site of empowerment and an object of resistance. It is suggested that a multilevelled conceptualization of power and resistance is required in order to untangle the complex political implications of sexuality and re-eroticization at work.
Arthroscopic Distal Clavicle Resection in Athletes
Authors: Charron Kevin M. , Schepsis Anthony A. , Voloshin Ilya
Published: November 2006

Background

The clinical success of arthroscopic distal clavicle resection for athletes has been well documented. There are, however, no published studies that prospectively compare the recovery rates in athletes as well as the outcomes of the indirect versus direct approaches.

Hypothesis

Both procedures are equally successful; however, the direct approach affords faster return to sports.

Study Design

Randomized controlled clinical trial; Level of evidence, 2.

Methods

Thirty-eight consecutive athletes with osteolysis of the distal clavicle or isolated posttraumatic arthrosis of the acromioclavicular joint without instability underwent arthroscopic distal clavicle resection. The patients were randomized into 2 groups: a direct superior approach and an indirect subacromial approach. American Shoulder and Elbow Surgeons and Athletic Shoulder Scoring System scores were measurable outcomes.

Results

Thirty-four athletes were available for a minimum 2-year follow-up. The 2 groups were similar, including preoperative American Shoulder and Elbow Surgeons and Athletic Shoulder Scoring System scores. Both groups demonstrated significant improvement in both scores at final follow-up when compared with preoperative scores (P < .001). The direct group demonstrated higher American Shoulder and Elbow Surgeons (82 vs 64) and Athletic Shoulder Scoring System (74 vs 56) scores at week 2 (P < .001) and week 6 (American Shoulder and Elbow Surgeons, 88 vs 77; Athletic Shoulder Scoring System, 87 vs 73) (P < .001). At final follow-up, both groups demonstrated excellent clinical outcomes, even though there was a statistical difference in scores, with the direct group scoring better (American Shoulder and Elbow Surgeons, 95.7 vs 91.2; Athletic Shoulder Scoring System -94.9 vs 88.3). The direct group demonstrated faster return to sports (mean, 21 days) than the indirect group (mean, 42 days) (P < .001). Radiographic analysis demonstrated an equivalent resection. One patient in each group had a clinically insignificant increase in coracoclavicular distance.

Conclusions

Both the direct superior approach and the indirect subacromial approach to the arthroscopic distal clavicle resection result in successful clinical outcome with clinically insignificant difference at final follow-up. Athletes treated with the direct superior approach improved faster clinically and returned to sports earlier.
Effects of organochlorine pesticides on interleukin secretion from lymphocytes
Authors: Beach T M , Whalen M M
Published: November 2006

Organochlorine pesticides have been used worldwide primarily as insecticides. Due to their chemical stability, they often persist in the environment long after their use has ceased. In a previous study, we found that six organochlorine compounds (α-chlordane, γ-chlordane, 4,4′-DDT, heptachlor, oxychlordane, and pentachlorophenol (PCP)), at concentrations of 5 μM, were able to significantly decrease the ability of highly purified human natural killer (NK) cells to lyse tumor cells after exposures, ranging from 1 hour to 6 days. However, if T cells were present with the NK cells (T/NK cells), loss of lytic function was seen only with oxychlordane and PCP. The purpose of the current study is to begin to investigate the mechanism by which T cells may be blocking the negative effects of some organochlorine compounds on NK cell function. Here, we investigated the hypothesis that T cells could produce significant levels of NK-stimulatory interleukin(s) (ILs), and that this may account for the decreased inhibition seen with organochlorine exposures when T cells were present. Secretion of four cytokines that have a demonstrated capacity to influence NK function, and/or are secreted by T cells, was measured (IL-2, IL-4, IL-10, IL-12). We measured both the baseline levels of ILs and the effects of organochlorine compound on IL secretion in T/NK cells. The results showed that baseline levels of the NK-stimulatory IL, IL-12, were 898±264 pg/mL at 24 hours and IL-10 levels were 564±337 pg/mL. In contrast, IL-2 levels were 14±10 pg/mL, and IL-4 levels were 3±2 pg/mL at 24 hours. The two compounds that retained their capacity to decrease NK lytic function in T/NK cells, oxychlordane (5 μM) and PCP (5 and 10 μM), were able to either decrease the secretion of NK-stimulatory ILs (IL-2, IL-12 and/or IL-10) and/or increase secretion of the NK-inhibitory cytokine, IL-4, at each length of exposure tested.
Effect of lead exposure on serum immunoglobulins and reactive nitrogen and oxygen intermediate
Authors: Mishra K P , Chauhan U K , Naik Sita
Published: November 2006

Metal toxicants may affect immune regulation with an increased incidence of infectious diseases, cancer or autoimmune diseases. Lead is the leading environmental toxin among heavy metals and has aroused concern, as continuous low-level exposure leads to a variety of health problems. We compared serum immunoglobulins (Ig) and reactive oxygen and nitrogen intermediates (super oxide and nitric oxide (NO)) in culture supernatant of lead-exposed (blood lead; Pb-B > 10 μg/dL) individuals with that of unexposed healthy controls (blood lead <10 μg/dL). The serum IgA level was significantly increased in lead-exposed individuals in comparison to controls (1829±53 versus 1389±52 μg/dL; ( P <0.05). Furthermore, lipopolysaccharide-induced NO production by mouse macrophage cells, RAW 264.7, showed significant suppression (P<0.05) after treatment with lead acetate (100 ppm). This study suggested that lead could modulate the immune system by targeting the humoral as well as innate immune cells.