bluuebunny/crossref_metadata_2025_split huggingface dataset:
Thermal state of permafrost and active‐layer monitoring in the antarctic: Advances during the international polar year 2007–2009
Authors: Vieira Gonçalo , Bockheim James , Guglielmin Mauro , Balks Megan , Abramov Andrey A , Boelhouwers Jan , Cannone Nicoletta , Ganzert Lars , Gilichinsky David A. , Goryachkin Sergey , López‐Martínez Jerónimo , Meiklejohn Ian , Raffi Rossana , Ramos Miguel , Schaefer Carlos , Serrano Enrique , Simas Felipe , Sletten Ronald , Wagner Dirk 
Published: June 2010

AbstractResults obtained during the International Polar Year (IPY) on the thermal state of permafrost and the active layer in the Antarctic are presented, forming part of ANTPAS (‘Antarctic Permafrost and Soils’), which was one of the key projects developed by the International Permafrost Association and the Scientific Committee for Antarctic Research for the IPY. The number of boreholes for permafrost and active‐layer monitoring was increased from 21 to 73 during the IPY, while CALM‐S sites to monitor the active layer were increased from 18 to 28. Permafrost temperatures during the IPY were slightly below 0°C in the South Shetlands near sea‐level, showing that this area is near the climatic boundary of permafrost and has the highest sensitivity to climate change in the region. Permafrost temperatures were much lower in continental Antarctica: from the coast to the interior and with increasing elevation they ranged between −13.3°C and −18.6°C in Northern Victoria Land, from −17.4°C to −22.5°C in the McMurdo Dry Valleys, and down to −23.6°C at high elevation on Mount Fleming (Ross Island). Other monitored regions in continental Antarctica also showed cold permafrost: Queen Maud Land exhibited values down to −17.8°C on nunataks, while in Novolazarevskaya (Schirmacher Oasis) at 80 m a.s.l. the permafrost temperature was −8.3°C. The coastal stations of Molodeznaya at Enderby Land showed permafrost temperatures of −9.8°C, Larsemann Hills – Progress Station in the Vestfold Hills region – recorded −8.5°C, and Russkaya in Marie Byrd Land, −10.4°C. This snapshot obtained during the IPY shows that the range of ground temperatures in the Antarctic is greater than in the Arctic. Copyright © 2010 John Wiley & Sons, Ltd.
Gain of local structure in an amphipathic peptide does not require a specific tertiary framework
Authors: Roman Ernesto A. , Rosi Pablo , Lebrero Mariano C. González , Wuilloud Rodolfo , Flecha F. Luis González , Delfino José M. , Santos Javier 
Published: June 2010

AbstractIn this work, we studied how an amphipathic peptide of the surface of the globular protein thioredoxin, TRX94‐108, acquires a native‐like structure when it becomes involved in an apolar interaction network. We designed peptide variants where the tendency to form α‐helical conformation is modulated by replacing each of the leucine amino acid residues by an alanine. The induction of structure caused by sodium dodecyl sulfate (SDS) binding was studied by capillary zone electrophoresis, circular dichroism, DOSY‐NMR, and molecular dynamics simulations (MDS). In addition, we analyzed the strength of the interaction between a C18 RP‐HPLC matrix and the peptides. The results presented here reveal that (a) critical elements in the sequence of the wild‐type peptide stabilize a SDS/peptide supramolecular cluster; (b) the hydrophobic nature of the interaction between SDS molecules and the peptide constrains the ensemble of conformations; (c) nonspecific apolar surfaces are sufficient to stabilize peptide secondary structure. Remarkably, MDS shed light on a contact network formed by a limited number of SDS molecules that serves as a structural scaffold preserving the helical conformation of this module. This mechanism might prevail when a peptide with low helical propensity is involved in structure consolidation. We suggest that folding of peptides sharing this feature does not require a preformed tightly‐packed protein core. Thus, the formation of specific tertiary interactions would be the consequence of peptide folding and not its cause. In this scenario, folding might be thought of as a process that includes unspecific rounds of structure stabilization guiding the protein to the native state. Proteins 2010. © 2010 Wiley‐Liss, Inc.
Quantitative description of dark current–voltage characteristics of multicrystalline silicon solar cells based on lock‐in thermography measurements
Authors: Breitenstein Otwin , Khanna Ankit , Warta Wilhelm 
Published: June 2010

AbstractA model is introduced which divides a solar cell locally into a ‘baseline’ region, showing a homogeneous exponential characteristic with a low ideality factor, and local ‘shunt’ regions which additionally show an inhomogeneous depletion region recombination current with a high, locally varying ideality factor. By measuring only three lock‐in thermograms and the corresponding currents at one reverse and two different forward biases, the local ohmic contributions, the positions of the shunt regions, the diode parameters of the baseline region, and the local diode parameters of the shunt regions are obtained. Based on these data a good fit of dark current–voltage characteristics of real solar cells over the whole bias range is obtained. These data may be used in a local network model of the cell. magnified image
Measured dark I–V characteristic (squares) and characteristic simulated from evaluating three lock‐in thermograms (line).
Analysis of fluctuation processes in forward‐biased solar cells using noise spectroscopy
Authors: Macku Robert , Koktavy Pavel 
Published: June 2010

AbstractThe manufacturing technology of n+p solar cells currently features a very high level of perfection. Its further development appears to be limited by amongst other issues imperfect diagnostic methods. The objective of our research consists in non‐destructive studies of processes that influence specimen life and reliability. To this end, we are going to employ noise‐based analysis methods. These methods are closely related to some specimen bulk imperfections, crystal‐lattice‐defect‐induced traps, local‐stress‐subjected regions and, finally, breakdowns, which might bring about specimen destruction. Based on a detailed study and understanding of transport processes, regions in which noise is generated can be identified and appropriate technological measures can be proposed and adopted. Our research focuses, first of all, on the structures, which are inhomogeneous in their nature and are difficult to diagnose. On the basis of our experiments carried out to date, it has been established that the noise signal arises as a consequence of several concurrent processes. A noise model has been worked out and a mathematical description of separate noise source behaviour has been suggested. Our model includes the shot noise, the 1/f noise and a 1/f2 spectrum type noise and provides an account of the unconventional behaviour of solar cells.
1.3 µm InAs/GaAs quantum dots with broad emission spectra
Authors: Tian Peng , Huang Lirong , Jiang Bo , Fei Shuping , Huang Dexiu 
Published: June 2010

AbstractInAs/GaAs quantum dot (QD) structures with broad emission spectra are grown by metal‐organic chemical vapor deposition. The effects of Indium composition of InGaAs strain‐reducing layer and InAs deposited coverage on the optical properties and structural characterization of QDs are investigated using photoluminescence (PL) and atomic force microscopy. It is found that through appropriately selecting growth parameters, the full width at half maximum of PL spectrum reaches up to 183 nm around 1.3 µm, covering the range from 1156 to 1339 nm.
The effect of ballistic and quasi‐ballistic electrons on the efficiency droop of InGaN light emitting diodes
Authors: Ni X. , Li X. , Lee J. , Liu S. , Avrutin V. , Özgür Ü. , Morkoç H. , Matulionis A. , Paskova T. , Mulholland G. , Evans K. R. 
Published: June 2010

AbstractThe effect of hot electrons on electroluminescence of m ‐plane double heterostructure light emitting diodes (with a single 6 nm active layer of In0.20Ga0.80N) is investigated. Diodes with an electron blocking layer (Al0.15Ga0.85N) demonstrate from 3 to 5 times higher electroluminescence efficiency than those without a blocking layer. The lower electroluminescence efficiency in devices without the blocking layer is ex‐ plained in terms of electron overflow caused by ballistic and quasi‐ballistic transport of injected electrons across the InGaN active region. The same mechanism explains the decrease, observed at high current densities, of the electroluminescence efficiency (efficiency droop) in the In0.20Ga0.80N diodes with the Al0.15Ga0.85N blocking layer. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Efficient nanocoax‐based solar cells
Authors: Naughton M. J. , Kempa K. , Ren Z. F. , Gao Y. , Rybczynski J. , Argenti N. , Gao W. , Wang Y. , Peng Y. , Naughton J. R. , McMahon G. , Paudel T. , Lan Y. C. , Burns M. J. , Shepard A. , Clary M. , Ballif C. , Haug F.‐J. , Söderström T. , Cubero O. , Eminian C. 
Published: June 2010

AbstractThe power conversion efficiency of most thin film solar cells is compromised by competing optical and electronic constraints, wherein a cell must be thick enough to collect light yet thin enough to efficiently extract current. Here, we introduce a nanoscale solar architecture inspired by a well‐known radio technology concept, the coaxial cable, that naturally resolves this “thick–thin” conundrum. Optically thick and elec‐ tronically thin amorphous silicon “nanocoax” cells are in the range of 8% efficiency, higher than any nanostructured thin film solar cell to date. Moreover, the thin nature of the cells reduces the Staebler–Wronski light‐induced degradation effect, a major problem with conventional solar cells of this type. This nanocoax represents a new platform for low cost, high efficiency solar power. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
p‐polarized infrared attenuated total reflection study of InN thin films grown on Si(111) substrate
Authors: Ng S. S. , Lee S. C. , Ooi P. K. , Hassan Z. , Abu Hassan H. , Chen W. L. 
Published: June 2010

AbstractWe report for the first time the surface phonon polariton (SPP) and interface phonon polariton (IPP) characteristics of InN thin films grown on AlN buffer layer on Si(111) substrate by molecular beam expitaxy. The p‐polarized infrared attenuated total reflection technique was used to excite the SPP and IPP modes of the sample. It was found that the SPP mode of InN and the IPP mode of InN/AlN were clearly ob‐ served at 609 cm–1 and 877 cm–1, respectively. The origins of the observed peaks were verified by theoretical simulations based on the anisotropic model. In general, a good agreement between the experimental and theoretical results was obtained. Finally, the effect of the free carriers on the SPP mode is discussed. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A comparison of SIMS and DESI and their complementarities
Authors: Salter T. L. , Green F. M. , Gilmore I. S. , Seah M. P. , Stokes P. 
Published: June 2010

AbstractThe most prevalent of the ambient mass spectrometries, desorption electrospray ionisation (DESI), which provides highly sensitive mass spectrometry from surfaces without the constraint of vacuum, is compared with secondary ion mass spectrometry (SIMS). The potential of DESI has been demonstrated in a wide range of application areas, including forensics, homeland security, counterfeit detection of pharmaceuticals and biological analysis. As with all techniques, there are some disadvantages: DESI cannot generally desorb molecules that are strongly bound to surfaces; there are low signals from molecules with low ionisation efficiency; and the spatial resolution is currently limited to approximately 100 µm. For these studies, SIMS is more powerful, but the two mass spectrometries are highly complementary. DESI uses a gentler desorption mechanism to remove material from the surface than the sputtering involved in SIMS. In particular, large fragile molecules can be detected intact, rather than heavily fragmented as in SIMS. Here, we illustrate the complementarities of SIMS and DESI for the analysis of 18 industrially relevant organic molecules. © Crown copyright 2010. Reproduced by permission of the Controller of HMSO and the Queen's printer for Scotland.
Advanced SIMS quantification in the first few nm of B, P and As ultrashallow implants
Authors: Merkulov A. , Peres P. , Choi S. , Desse F. , Schuhmacher M. 
Published: June 2010

AbstractThis paper presents an investigation on SIMS profile quantification for ultra‐shallow profiles. New configuration for the Cesium and Oxygen sources on the CAMECA IMS Wf tool provides SIMS profiling capability at 150 eV impact energy with a sputter rate of 1 and 2 nm/min for the Cs+ and O2+ primary beams, respectively. Results for as‐implanted B, P and As profiles using extremely low impact energy (EXLIE) sputtering conditions are compared with HR‐RBS and ERDA profiles. Copyright © 2010 John Wiley & Sons, Ltd.
Nano‐SIMS investigation of boron distribution in steels
Authors: Valle N. , Drillet J. , Pic A. , Migeon H.‐N. 
Published: June 2010

AbstractThe introduction of boron in amounts of tens parts per million (ppm) increases the hardenability of steels. Nevertheless, this positive effect of boron can drastically be reduced during the industrial process if boron precipitation occurs. In order to identify the different steps of boron precipitation for the main parts of the process (deformation at high temperature, cooling and welding), the distribution of boron in high strength steels is studied through SIMS nano‐analysis. It is shown that the B state and the nature of the B precipitates can be directly deduced from different ion maps (11B, 12C, 11B12C, 11B14N, 11B16O) acquired simultaneously. Depending on the progress of the process, borocarbides and boron nitrides precipitates are observed. Copyright © 2010 John Wiley & Sons, Ltd.
Numerical approach to resolve mass interference in depth profiling As in SiGe
Authors: Gui D. , Huang Y. H. , Nistala R. R. , Xing Z. X. , Mo Z. Q. , Hua Y. N. , Cha L. Z. 
Published: June 2010

AbstractSIMS analysis of SiGe material is intricate and challenging due to the mass interference effects. For instance, analysis of arsenic (As) in SiGe requires ultra‐high mass resolution (MR) to resolve the mass interferences to As and AsSi. Unfortunately, the ultra‐high MR is achieved at the cost of sensitivity for magnetic sector SIMS. Especially in the case of low‐dose As implantation, 75As28Si− should be monitored to ensure enough dynamic range. But the required MR to resolve mass interference of 74Ge29Si− to 75As28Si− is too high for all types of SIMS systems. In this work, a numerical approach has been developed to eliminate the mass interference to AsSi based on the dependence of interference ion intensity on Ge concentration. An undoped SiGe sample with a Ge fraction of 0.128 was used as the reference sample to determine the dependence of interference ion intensity on Ge‐contained reference ions intensity. Interpolation algorithm was applied to minimize the deviation caused by the test time difference. The effectiveness of two interpolation algorithms, linear and exponential interpolation, was evaluated in this paper. Gaussian‐like profiles of As implantation with the dose of 3.6E13 at/cm2 and 1E15 at/cm2 were obtained with this numerical approach. The profile of 1E15 at/cm2 As implantation agreed quite well with that obtained with ultra‐high mass resolution, and achieved at least two orders of improvement in the dynamic range. Copyright © 2010 John Wiley & Sons, Ltd.
A framework for groupware‐supported software architecture evaluation process in global software development
Authors: Ali Babar Muhammad 
Published: June 2010

SUMMARYA software architecture evaluation process requires a large number of stakeholders to be collocated for evaluation sessions. Given an increasing trend to using globally distributed software development teams, organizations are likely to be discouraged from introducing disciplined software architecture evaluation practices that require collocated stakeholders. To address this issue, we propose that a software architecture evaluation can be carried out using suitable groupware systems. In this paper, we present a framework for supporting the software architecture evaluation process using a groupware system. The framework highlights the changes that are required in the existing software architecture evaluation methods. We provide an illustrated example of modeling and mapping the activities of the presented process on electronic workspaces provided by a groupware system. We also identify some of the features that a groupware system should provide to successfully support the process. Copyright © 2010 John Wiley & Sons, Ltd.
Tribological properties of hydrophilic polymer brushes under wet conditions
Authors: Kobayashi Motoyasu , Takahara Atsushi 
Published: June 2010

AbstractThis article demonstrates a water‐lubrication system using high‐density hydrophilic polymer brushes consisting of 2,3‐dehydroxypropyl methacrylate (DHMA), vinyl alcohol, oligo(ethylene glycol)methyl ether methacrylate, 2‐(methacryloyloxy)ethyltrimethylammonium chloride (MTAC), 3‐sulfopropyl methacrylate potassium salt (SPMK), and 2‐methacryloyloxyethyl phosphorylcholine (MPC) prepared by surface‐initiated controlled radical polymerization. Macroscopic frictional properties of brush surfaces were characterized by sliding a glass ball probe in water using a ball‐on‐plate type tribotester under the load of 0.1–0.49 N at the sliding velocity of 10−5–10−1 m s−1 at 298 K. A poly(DHMA) brush showed a relatively larger friction coefficient in water, whereas the polyelectrolyte brushes, such as poly(SPMK) and poly(MPC), revealed significantly low friction coefficients below 0.02 in water and in humid air conditions. A drastic reduction in the friction coefficient of polyelectrolyte brushes in aqueous solution was observed at around 10−3–10−2 m s−1 owing to the hydrodynamic lubrication effect, however, an increase in salt concentration in the aqueous solution led to the increase in the friction coefficients of poly(MTAC) and poly(SPMK) brushes. The poly(SPMK) brush showed a stable and low friction coefficient in water even after sliding over 450 friction cycles, indicating a good wear resistance of the brush film. © 2010 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 10: 208–216; 2010: Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/tcr.201000001
Premature ejaculation: definition, assessment and management
Authors: Steggall Martin J. 
Published: June 2010

AbstractPremature ejaculation can be a distressing condition for men and their partners. The author discusses the different behavioural and drug treatments available, but makes it clear that there is no recommended first‐line therapy. Each case should be judged individually, taking into account the man's mental state and the status of his relationship. Copyright © 2010 Wiley Interface Ltd
Biases of traditional term prediction models: results from different sample‐based models evaluated on 41 343 ultrasound examinations
Authors: Økland I. , Gjessing H. K. , Grøttum P. , Eik‐Nes S. H. 
Published: June 2010

AbstractObjectiveTo evaluate two Norwegian traditional, sample‐based term prediction models as applied to the data from a large population‐based registry. The two models were also compared with an established German model.MethodsOur database included information from 41 343 non‐selected ultrasound scans registered over the years 1987–2005. The prediction models were applied to measurements from the ultrasound examinations, and the resulting term predictions were compared with the actual times of the deliveries. The median bias (the difference between the true and the predicted date of delivery) was calculated for each model, both for the study population as a whole and for subgroups of measurements of biparietal diameter (BPD) and femur length (FL). Secondary measures, i.e. proportion of births within ± 14 days and the rates of preterm and post‐term deliveries, were also assessed.ResultsThe analyses showed that the models had significant biases, predicting delivery date either too late or too early. For each model the size of the bias varied, depending on the fetal size at the time of the examination; the extremes were minus 4 and plus 4 days for the BPD‐based predictions. There were similar results with the FL‐based predictions.ConclusionTerm predictions made with traditional sample‐based models had significant biases that varied over each method's measurement range. These models have important shortcomings, probably because of strict selection criteria in the process of constructing the models, and because the methods primarily aim at estimating the last menstrual period‐based day of conception, not the day of birth. Copyright © 2010 ISUOG. Published by John Wiley & Sons, Ltd.
Monochorionic monoamniotic twin pregnancies with two yolk sacs may not be a rare finding: a report of two cases
Authors: Murakoshi T. , Ishii K. , Matsushita M. , Shinno T. , Naruse H. , Torii Y. 
Published: June 2010

AbstractThe exact determination of amnionicity is a major issue for the clinical management of monochorionic twin pregnancies, due to the high risk of perinatal mortality and morbidity in monochorionic monoamniotic (MCMA) twins. Counting the number of yolk sacs is believed to be a good indicator of amnionicity in the early first trimester, and it has previously been suggested that the number of yolk sacs is equal to amnionicity in both MCMA and monochorionic diamniotic twin pregnancies. However, the accuracy of the relationship between number of yolk sacs and amnionicity has recently been called into question. To the best of our knowledge, no previous reports have shown two yolk sacs in MCMA twin pregnancies. We report two cases of MCMA twins with two yolk sacs on first‐trimester ultrasonography, and confirmed monoamnionicity in the second trimester showing umbilical cord entanglement. Postnatal examination showed an MCMA placenta in both cases, and entangled umbilical cords confirmed monoamnionicity. The possibility of monoamnionicity must still be suspected when two yolk sacs are detected early in the first trimester on ultrasound examination in monochorionic twin pregnancies. Copyright © 2010 ISUOG. Published by John Wiley & Sons, Ltd.
Isolated single umbilical artery: need for specialist fetal echocardiography?
Authors: DeFigueiredo D. , Dagklis T. , Zidere V. , Allan L. , Nicolaides K. H. 
Published: June 2010

AbstractObjectiveTo examine the association between single umbilical artery (SUA) and cardiac defects and to determine whether patients with SUA require specialist fetal echocardiography.MethodsIncidence and type of cardiac defects were determined in fetuses with SUA detected at routine second‐trimester ultrasound examination.ResultsA routine second‐trimester scan was performed in 46 272 singleton pregnancies at a median gestation of 22 (range, 18–25) weeks and an SUA was diagnosed in 246 (0.5%). Cardiac defects were diagnosed in 16 (6.5%) of these cases, including 10 (4.3%) in a subgroup of 233 with no other defects and in six (46.2%) of the 13 with multiple defects. In 11 (68.8%) of the 16 cases with cardiac defects the condition was readily diagnosable by evaluating the standard four‐chamber view and the views of the great arteries. In the remaining cases there was left persistent superior vena cava or small ventricular septal defect, where prenatal diagnosis may not be important because they are not associated with adverse outcome.ConclusionAlthough SUA is associated with an increased incidence of cardiac defects it may not be necessary to refer such patients for specialist fetal echocardiography because the defects are detectable by evaluating standard cardiac views that should be part of the routine second‐trimester scan. Copyright © 2010 ISUOG. Published by John Wiley & Sons, Ltd.