bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparison of long term series of total ozone and NO2 column measurements in the southern tropics by SAOZ/NDACC UV-Vis spectrometers and satellites
Authors: Pastel M. , Pommereau J.-P. , Goutail F. , Richter A. , Pazmiño A. , Ionov D.
Published: May 2013

Abstract. Long series of ozone and NO2 total column measurements at the Southern tropics are available from two ground-based SAOZ (Système d'Analyse par Observation Zenithale) UV-visible spectrometers operated within the NDACC (Network for the Detection of Amtospheric Composition Change) deployed in Bauru in S-E Brazil and Reunion Island in the S-W Indian Ocean in 1995 and 1993 respectively. Although at the same latitude, the data show larger columns of both species above the South American continent than above the Indian Ocean. For verifying the reliability of these data before carrying out trend analysis, they have been compared to satellites observations available during the same period. However, since no single satellite was operating from 1995 until present, the comparison requires the building of a composite, called merged satellites series. As systematic differences exist between the individual data sets because of the many differences between instruments, spectral ranges, absorption cross-sections, and retrieval procedures used, the building of such a composite requires thorough evaluation and normalisation of each. From comparisons with SAOZ, the merged satellite data set build with EP-TOMS from 1995 to 2004 and OMI-TOMS from 2005 to 2012 are found best for ozone in the Southern tropics. After correction for biases with SAOZ, both are confirming the larger ozone columns reported by SAOZ above South America compared to the Indian Ocean shown to origin from ozone production by lightning NOx (LNOx) over the continent in the summer and the advection from Africa of ozone produced by biomass burning emissions in the winter. For NO2, best matching the SAOZ is a combination of GOME GDP4 1996–2003 and SCIAMACHY 2003–2012 products, after correction for the photochemical diurnal change of the concentration of the species between the SAOZ twilight observations and the time of satellites overpasses. The merged data series built from the data of these two satellites fully confirms the larger NO2 column reported by SAOZ above the South American continent as well as and its seasonality. The 35% larger column above Brazil in the summer is shown to be due to the NOx production in the upper troposphere by the frequent lightning during the thunderstorm season, whereas the winter maximum is shown to come from the larger exchange of NOx rich air with mid-latitudes in the lower stratosphere due to the more equatorial latitude of the subtropical jet above South America compared to the Indian Ocean.
Differential response of planktonic primary, bacterial, and dimethylsulfide production rates to vertically-moving and static incubations in upper mixed-layer summer sea waters
Authors: Galí M. , Simó R. , Pérez G. L. , Ruiz-González C. , Sarmento H. , Royer S.-J. , Fuentes-Lema A. , Gasol J. M.
Published: May 2013

Abstract. Microbial plankton experience fluctuations in total solar irradiance and in its spectral composition as they are vertically moved by turbulence in the oceanic upper mixed layer (UML). The fact that the light exposure is not static but dynamic may have important consequences for biogeochemical processes and ocean-atmosphere fluxes. However, most biogeochemical processes other than primary production, like bacterial production or dimethylsulfide (DMS) production, are seldom measured in sunlight and even less often in dynamic light fields. We conducted four experiments in oligotrophic summer stratified Mediterranean waters, where a sample from the UML was incubated in ultraviolet (UV)-transparent bottles at three fixed depths within the UML and on a vertically-moving basket across the same depth range. We assessed the response of the phyto- and bacterioplankton community with physiological indicators based on flow cytometry singe-cell measurements, Fast Repetition Rate fluorometry (FRRf), phytoplankton pigment concentrations and particulate light absorption. Dynamic light exposure caused a disruption of the photoinhibition and photoacclimation processes associated to ultraviolet radiation (UVR), which slightly alleviated bacterial photoinhibition but did not favor primary production. Gross DMS production (GPDMS) decreased sharply with depth in parallel to shortwave UVR, and displayed a dose-dependent response that mixing did not significantly disrupt. To our knowledge, we provide the first measurements of GPDMS under in situ UV-inclusive optical conditions.
A first chronology for the NEEM ice core
Authors: Rasmussen S. O. , Abbott P. , Blunier T. , Bourne A. , Brook E. , Buchardt S. L. , Buizert C. , Chappellaz J. , Clausen H. B. , Cook E. , Dahl-Jensen D. , Davies S. , Guillevic M. , Kipfstuhl S. , Laepple T. , Seierstad I. K. , Severinghaus J. P. , Steffensen J. P. , Stowasser C. , Svensson A. , Vallelonga P. , Vinther B. M. , Wilhelms F. , Winstrup M.
Published: May 2013

Abstract. A stratigraphy-based chronology for the North Greenland Eemian Ice Drilling (NEEM) ice core has been derived by transferring the annual layer counted Greenland Ice Core Chronology 2005 (GICC05) from the NGRIP core to the NEEM core using 787 match points of mainly volcanic origin identified in the Electrical Conductivity Measurement (ECM) and Dielectrical Profiling (DEP) records. Tephra horizons found in both the NEEM and NGRIP ice cores are used to test the matching based on ECM and DEP and provide additional horizons used for the time scale transfer. A thinning function reflecting the accumulated strain along the core has been determined using a Dansgaard–Johnsen flow model and an isotope-dependent accumulation rate parameterization. Flow parameters are determined from Monte Carlo analysis constrained by the observed depth-age horizons. In order to construct a chronology for the gas phase, the ice age–gas age difference (Δage) has been reconstructed using a coupled firn densification–heat diffusion model. Temperature and accumulation inputs to the Δage model, initially derived from the water isotope proxies, have been adjusted to optimize the fit to timing constraints from δ15N of nitrogen and high-resolution methane data during the abrupt onsets of interstadials. The ice and gas chronologies and the corresponding thinning function represent the first chronology for the NEEM core, and based on both the flow and firn modelling results, the accumulation history for the NEEM site has been reconstructed, providing the necessary basis for further analysis of the records from NEEM.
Spatial and temporal distribution of drainage and solute leaching in heterogeneous urban vegetation environments
Authors: Nouri H. , Beecham S. , Hassanli A. M. , Ingleton G.
Published: May 2013

Abstract. Deep percolation enhancement from recycled wastewater irrigation may contribute to salt accumulation and water table elevation that can ultimately cause soil and ground water degradation. The spatial and temporal variation of drainage rate and solute leaching were investigated in an urban park containing heterogeneous landscape plants that were irrigated with recycled wastewater. Field monitoring was undertaken at Veale Gardens in the Adelaide Parklands, Australia. Based on the landscape variation in Veale Gardens, two landscape zones were defined: one being largely covered with turf grasses with few trees and shrubs (MG) with the second zone being mostly trees and shrubs with intermittent turf grasses (MT). Experiments were performed using two zero-tension lysimeters placed horizontally 100 cm below ground to monitor the spatio-temporal behaviour of drained water and nutrient loadings for four seasons. The outcomes showed a large spatial and temporal variation of drainage quantity and quality in the MT and MG zones. The low vegetation cover in the MG zone resulted in more drained water than in the high vegetation cover (MT zone). In both zones, more drainage water was collected in winter than in other seasons. This is in spite of the input water showing a maximum rate in summer. The seasonal salinities measured in the two lysimeters showed very similar trends with the lowest salinity rate in autumn with the levels increasing through winter and spring. Chemical analyses of the leachate solute indicated no detrimental impact from using recycled wastewater during the study period.
Post processing rainfall forecasts from numerical weather prediction models for short term streamflow forecasting
Authors: Robertson D. E. , Shrestha D. L. , Wang Q. J.
Published: May 2013

Abstract. Sub-daily ensemble rainfall forecasts that are bias free and reliably quantify forecast uncertainty are critical for flood and short-term ensemble streamflow forecasting. Post processing of rainfall predictions from numerical weather prediction models is typically required to provide rainfall forecasts with these properties. In this paper, a new approach to generate ensemble rainfall forecasts by post processing raw NWP rainfall predictions is introduced. The approach uses a simplified version of the Bayesian joint probability modelling approach to produce forecast probability distributions for individual locations and forecast periods. Ensemble forecasts with appropriate spatial and temporal correlations are then generated by linking samples from the forecast probability distributions using the Schaake shuffle. The new approach is evaluated by applying it to post process predictions from the ACCESS-R numerical weather prediction model at rain gauge locations in the Ovens catchment in southern Australia. The joint distribution of NWP predicted and observed rainfall is shown to be well described by the assumed log-sinh transformed multivariate normal distribution. Ensemble forecasts produced using the approach are shown to be more skilful than the raw NWP predictions both for individual forecast periods and for cumulative totals throughout the forecast periods. Skill increases result from the correction of not only the mean bias, but also biases conditional on the magnitude of the NWP rainfall prediction. The post processed forecast ensembles are demonstrated to successfully discriminate between events and non-events for both small and large rainfall occurrences, and reliably quantify the forecast uncertainty. Future work will assess the efficacy of the post processing method for a wider range of climatic conditions and also investigate the benefits of using post processed rainfall forecast for flood and short term streamflow forecasting.
On Kristeva's Fiction
Authors: Trigo Benigno
Published: May 2013

An essay about the reception of Kristeva's fiction so far in the popular press and in academic journals, as well as an inquiry into its use and value as a psychoanalytic antidote.
Narrative Ethics and Vulnerability: Kristeva and Ricoeur on Interdependence
Authors: Purcell Elizabeth
Published: May 2013

The character and extent of disabilities, especially cognitive disability, have posed significance problems for existing moral theories. Certain philosophers have even questioned the moral personhood of people with disabilities and have argued that people with profound cognitive impairments should not be granted the same moral status as those who are cognitively able-bodied. This paper proposes an alternative understanding of moral personhood as relational rather than individuated. This relational moral personhood finds its foundation in the clinical practice and psychoanalysis of Julia Kristeva and the hermeneutic narrative identity of Paul Ricoeur. One consequence of this relational personhood is a new understanding of moral status through narrative co-authorship rather than intellectual or social capacity. Another consequence is a refiguration of narrative identity as narrative interdependence.
Anemophilous plant pollen in spring specific honeys from the Rzeszów area
Authors: Ceglińska Katarzyna
Published: May 2013

The present study comprises pollen analyses of 23 samples of spring specific honeys collected from apiaries situated in 12 communes in the Rzeszów area during the 2005-2006 apicultural season. Forty two pollen taxa were identified in the examined material, of which 31 nectariferous and 11 non-nectariferous anemophilous plants. Among the nectariferous plants, the highest pollen frequency was found for Brassicaceae (others) (95.7%), Rubus type (91.3%) and Prunus type (86.9%). The presence of anemophilous pollen grains was recorded in all the samples, with Poaceae reaching the highest frequency (69.8%). The frequency of over 50% was characteristic of Quercus and Rumex, while the lowest frequency (less than 10%) was recorded for Cerealia, Corylus avellana and Humulus lupulus. The highest participation was found for Quercus, whose pollen grains constituted as much as 80% of anemophilous pollen grains in a single sample. The lowest participation (below 3%) was found for Rumex, Pinus and Artemisia. Among all the taxa of pollen grains found in a single sample, Poaceae pollen reached the highest share of anemophilous pollen in a sample of honey from fruit trees (10%), whereas Quercus pollen in one honey from Brassica napus (7.8%) and in one honey from Acer (4.5%). The pollen share of the remaining anemophilous taxa in the examined honeys ranged between 0.2% and 2.9%. The identified anemophilous taxa belong to 10 botanical families. In 19 out of 23 examined samples of honeys, small indicators of honeydew were discovered.
Fungi colonizing shoots of common yew (Taxus baccata L.) in the Jagiellonian University Botanic Garden in Cracow
Authors: Mirski Waldemar
Published: May 2013

The aim of the investigations was determination the reasons of dying down of needles and branches of common yew (Taxus baccata L.) in the park collection of Botanic Garden of Jagiellonian University in Cracow. The disease changes of infectious nature were observed on the examined plants' parts. The changes'appearance, its location and extent were described in details. At first the spots were brown colour with distinct hem. Then the needle and branch tissues were dying down. From end of May to July mass falling down of infesteted needles was observed. Mycological analysis of diseased tissues showed 34 fungi species. To the dominant species belonged: Alternaria alternata, Colletotrichum gloeosporioides, Fusarium spp., Pestalotiopsis guepinii, Phomopsis juniperivora and Zythiostroma pinastri. Common yew pathogens: Phomopsis juniperivora and Sclerophoma pityophila were found among the isolated fungi.
A review of the tribes of Deltocephalinae (Hemiptera: Auchenorrhyncha: Cicadellidae)
Authors: Zahniser James N , Dietrich Chris
Published: May 2013

The classification of the largest subfamily of leafhoppers, Deltocephalinae, including 38 tribes, 923 genera, and 6683 valid species, is reviewed and revised. An updated phylogeny of the subfamily based on molecular (28S, Histone H3) and morphological data and an expanded taxon sample (37 taxa not included in previous analyses) is presented. Based on the results of these analyses and on the morphological examination of many representatives of the subfamily, the classification of the tribes and subtribes of Deltocephalinae is revised. Complete morphological descriptions, illustrations, lists of the included genera, and notes on their distribution, ecology, and important vector species are provided for the 38 recognized tribes and 18 subtribes. A dichotomous key to the tribes is provided. All names in the taxonomic treatments are hyperlinked to online resources for individual taxa which are supported by a comprehensive database for Deltocephalinae compiled using the taxonomic database software package 3I. The online functionality includes an interactive key to tribes and subtribes and advanced database searching options. Each taxon (subspecies through subfamily) has a unique taxon webpage providing nomenclatural information, lists of included taxa, an automated description (if available), images (if available), distributional information, bibliographic references and links to outside resources. Some observations and trends regarding the history of taxonomic descriptions in Deltocephalinae are reported. Four new tribes are described: Bahitini tribe nov. (25 genera), Bonsapeiini tribe nov. (21 genera), Phlepsiini tribe nov. (4 genera), and Vartini tribe nov. (7 genera). The circumscription and morphological characterization of Scaphoideini Oman, 1943 (61 genera) is substantially revised. Eleven new species are described: Acostemma stilleri sp. nov., Arrugada linnavuorii sp. nov., Drabescus zhangi sp. nov., Parabolopona webbi sp. nov., Goniagnathus emeljanovi sp. nov., Hecalus hamiltoni sp. nov., Scaphoideus omani sp. nov., Dwightla delongi sp. nov., Abimwa knighti sp. nov., Gannia viraktamathi sp. nov., and Doratulina dmitrievi sp. nov. Some family-group level taxonomic changes are made: Platymetopiini Haupt, 1929, Anoterostemmini Haupt, 1929, and Allygidiina Dmitriev, 2006 are synonymized with Athysanini Van Duzee, 1892, syn. nov.; Procepitini Dmitriev, 2002 is synonymized with Cicadulini Van Duzee, 1892, syn. nov.; Listrophorini Boulard, 1971 is synonymized with Chiasmini Distant, 1908, syn. nov.; Adamini Linnavuori & Al-Ne’amy, 1983, Dwightlini McKamey, 2003, and Ianeirini Linnavuori, 1978 are synonymized with Selenocephalini Fieber, 1872 syn.nov., and all three are now recognized as valid subtribes in their parent tribe. New placements of many genera to tribe and subtribe are made, and these are described in individual taxon treatments.
TRPM5-mediated calcium uptake regulates mucin secretion from human colon goblet cells
Authors: Mitrovic Sandra , Nogueira Cristina , Cantero-Recasens Gerard , Kiefer Kerstin , Fernández-Fernández José M , Popoff Jean-François , Casano Laetitia , Bard Frederic A , Gomez Raul , Valverde Miguel A , Malhotra Vivek
Published: May 2013

Mucin 5AC (MUC5AC) is secreted by goblet cells of the respiratory tract and, surprisingly, also expressed de novo in mucus secreting cancer lines. siRNA-mediated knockdown of 7343 human gene products in a human colonic cancer goblet cell line (HT29-18N2) revealed new proteins, including a Ca2+-activated channel TRPM5, for MUC5AC secretion. TRPM5 was required for PMA and ATP-induced secretion of MUC5AC from the post-Golgi secretory granules. Stable knockdown of TRPM5 reduced a TRPM5-like current and ATP-mediated Ca2+ signal. ATP-induced MUC5AC secretion depended strongly on Ca2+ influx, which was markedly reduced in TRPM5 knockdown cells. The difference in ATP-induced Ca2+ entry between control and TRPM5 knockdown cells was abrogated in the absence of extracellular Ca2+ and by inhibition of the Na+/Ca2+ exchanger (NCX). Accordingly, MUC5AC secretion was reduced by inhibition of NCX. Thus TRPM5 activation by ATP couples TRPM5-mediated Na+ entry to promote Ca2+ uptake via an NCX to trigger MUC5AC secretion.
Band Offsets at the ZnO/Cu2ZnSnS4 Interface Based on the First Principles Calculation
Authors: Bao Wujisiguleng , Ichimura Masaya
Published: May 2013

Cu2ZnSnS4 (CZTS) is attracting much attention recently as an absorber layer material in a heterojunction solar cell. We evaluate the valence band offset ΔE
v at the ZnO/CZTS heterojunction interface by calculating the local density of states for each atom in the heterostructure supercell by the first-principles method. ΔE
v is in the range of 0.8–1.3 eV, depending on the interface anion-atom species and the lattice constraint condition. The conduction band minimum of CZTS is predicted to be lower than that of ZnO.
A Study of Reducing the Residual Stresses for Multilayer Chip Inductors
Authors: Chien Shih-Feng , Tsai Yin-Lai , Lee Ying-Chieh , Lee Wen-Hsi
Published: May 2013

The residual stress built up by sintering causes not only the destruction of the structure of magnetic components but also a reduction in their permeability. In this paper, the relationship between residual stress and permeability is examined, and two possible methods for improving this situation are presented. Because one of the causes of increased residual stress is competition between the shrinking behaviors from the silver and ceramic layers inside the components during sintering, the first method is changing the particle size of the silver paste to alter its shrinking behavior. The results show that choosing a finer silver particle paste as the inner electrode material can reduce the onset temperature of shrinkage of the silver layer and then separate the silver layer from the ceramic layer to shrink the layers individually, reducing the residual stress. The second method is based on the phenomenon of separate shrinking seen in the first method, and we used carbon paste as the isolation layer for the silver and ceramic layers to achieve this. The results show that this method can reduce the residual stress more than the first one, although it can cause a high direct current resistance (DCR) and a low bending strength, and other conditions should be considered in order to avoid these weaknesses.
Effects of Doping Ratio and Thermal Annealing on Structural and Electrical Properties of Boron-Doped ZnO Thin Films by Spray Pyrolysis
Authors: Yu Cheng-Chang , Hsu Yu-Ting , Lee Shao-Yi , Lan Wen-How , Kuo Hsin-Hui , Shih Ming-Chang , Feng David Jui-Yang , Huang Kai-Feng
Published: May 2013

Boron-doped zinc oxide (BZO) thin films have been fabricated by spray pyrolysis on a glass substrate. The morphology and electrical properties of the thin films were investigated. X-ray diffraction (XRD) and scanning electron microscopy (SEM) analyses were performed. It was found that [B]/[Zn] ratio altered both the microstructure and concentration of the BZO thin films. The film grain size was reduced by increasing the [B]/[Zn] ratio. The highest Hall mobility was 3.65 cm2V-1s-1for the undoped ZnO thin film, and the highest carrier concentration of 1.0×1019cm-3was achieved for the as-deposited BZO thin film with [B]/[Zn] = 1.5 at. %. Conductivity was determined at different measurement temperatures and shallow donors provided the dominate conduction mechanism for the as-deposited BZO thin films. After 600 °C annealing, shallow level reduction and donors with a high activation energy of 129±6 meV in the BZO thin films were characterized, and the shallow donors that dominate the carrier concentration for the as-deposited spray-pyrolized BZO thin film were eliminated.
Self-Separation of Sublimation-Grown AlN with AlSiN Buffer Layer
Authors: Nishino Katsushi , Nakauchi Jun , Hayashi Kotaro , Tsukihara Masashi
Published: May 2013

AlN was grown by a sublimation method on 6H-SiC. We found the grown AlN layer is easily separated from the substrate when Si powder is added to the AlN source powder. The formation of AlSiN layer with the Si content of 15% at the AlN/6H-SiC interface was confirmed by energy-dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD). This AlSiN layer causes the separation of AlN.
In situ X-ray Reflectivity Measurements on Annealed InxGa1-xN Epilayer Grown by Metalorganic Vapor Phase Epitaxy
Authors: Ju Guangxu , Fuchi Shingo , Tabuchi Masao , Takeda Yoshikazu
Published: May 2013

The thermal decomposition of c-plane GaN/sapphire templates was studied in a metalorganic vapor phase epitaxy (MOVPE) system installed in a laboratory-level X-ray diffractometer by using in situ X-ray reflectivity (XRR). GaN remained thermally stable in pure N2 up to 900 °C, while a significant decomposition occurred at 950 °C. Then, thin In
x
Ga1-x
N epilayers were grown on the annealed templates at 830 °C. In situ XRR measurements were conducted before and after InGaN growth. By theoretical and experimental analyses of the XRR spectra, the sample structure change upon thermal annealing was clarified. Photoluminecescence (PL) and atomic force microscopy (AFM) results demonstrated that thermal annealing affected the optical properties and microstructures of InGaN films. The PL peaks from InGaN slightly blue-shifted with thermal annealing.
Accumulation of Background Impurities in Hydride Vapor Phase Epitaxy Grown GaN Layers
Authors: Usikov Alexander , Soukhoveev Vitali , Kovalenkov Oleg , Syrkin Alexander , Shapovalov Liza , Volkova Anna , Ivantsov Vladimir
Published: May 2013

We report on accumulation of background Si and O impurities measured by secondary ion mass spectrometry (SIMS) at the sub-interfaces in undoped, Zn- and Mg-doped multi-layer GaN structures grown by hydride vapor phase epitaxy (HVPE) on sapphire substrates with growth interruptions. The impurities accumulation is attributed to reaction of ammonia with the rector quartz ware during the growth interruptions. Because of this effect, HVPE-grown GaN layers had excessive Si and O concentration on the surface that may hamper forming of ohmic contacts especially in the case of p-type layers and may complicate homo-epitaxial growth of a device structure.
Fabrication of InGaN/GaN Multiple Quantum Wells on (11̄01) GaN
Authors: Tanikawa Tomoyuki , Sano Tomotaka , Kushimoto Maki , Honda Yoshio , Yamaguchi Masahito , Amano Hiroshi
Published: May 2013

InGaN/GaN multiple quantum wells (MQWs) on semipolar (11̄01) GaN microstripes on a Si substrate were fabricated and their optical properties were investigated. From cathodoluminescence (CL) analysis, strong CL emission was obtained in an MQW emitting at 433 nm. However, dark lines appeared in MQWs emitting at longer wavelengths. These dark lines are attributed to lattice relaxation and the generation of misfit dislocations and stacking faults in an MQW, resulting in nonradiative centers. The internal quantum efficiency (IQE) was estimated from excitation-power-dependent photoluminescence analysis. The (11̄01) InGaN/GaN MQW had a high IQE owing to the high crystalline quality of the underlying GaN and the reduced piezoelectric field. The IQE at a carrier concentration of 1×1018 cm-3 in a sample emitting at 490 nm was as high as 90%. The efficiency decreased in a sample with a higher indium content in the MQW due to the generation of misfit dislocations and stacking faults.
Nucleation and Coalescence of Indium Rich InGaN Layers on Nitridated Sapphire in Metal–Organic Vapor Phase Epitaxy
Authors: Dinh Duc V. , Solopow Sergej , Pristovsek Markus , Kneissl Michael
Published: May 2013

We report on the evolution of N-polar wurtzite (0001̄) InGaN layers with high indium content grown directly on nitridated (0001) sapphire by metal–organic vapor phase epitaxy. In-situ ellipsometry showed an initial growth delay of 5–8 nm for layers with more than 45% indium content. Atomic force microscopy showed small dense islands which reached their final size after 5–8 nm deposition. The roughness saturated only after 15 nm, and the width of the X-ray diffraction (00.2) reflex showed a similar behavior. Therefore, N-polar InGaN grows via nucleation (d < 10 nm) followed by coalescence (d < 20 nm). With less than 40% indium the coalescence is much slower, very similar to Ga-polar (0001) GaN despite N-polarity of the InN layers. This indicates towards a surface transition between 40 and 50% indium content.
Direct Growth of AlN Single Crystal on Sapphire by Solution Growth Method
Authors: Matsubara Hiroaki , Mizuno Kohei , Takeuchi Yukihisa , Harada Shunta , Kitou Yasuo , Okuno Eiichi , Ujihara Toru
Published: May 2013

AlN was directly grown on a sapphire substrate by the solution growth method with the Cu–Si–Al–Ti solvent under a nitrogen gas flow. X-ray diffraction measurements revealed that the grown AlN was single crystal. The AlN layer was epitaxially formed on the sapphire substrate with the orientation relationships: (0001)AlN ∥(0001)sapphire and [1̄100]AlN ∥[112̄0]sapphire. The full widths at half maximum (FWHMs) of X-ray rocking curves for tilt and twist components were 414 and 2031 arcsec, respectively.
Spectral Sensitivity Tuning of Vertical InN Nanopyramid-Based Photodetectors
Authors: Winden Andreas , Mikulics Martin , Haab Anna , Grützmacher Detlev , Hardtdegen Hilde
Published: May 2013

In this paper, we report on the fabrication of InN nanopyramid-based photodetectors operating within the telecommunication wavelength range. We found that the spectral sensitivity of individually addressable InN nanopyramids can be tuned within an interval of 1550–1750 nm since the band edge luminescence energy correlates with the structure size. According to this, we optimized the nanopatterning technique of SiO2/GaN/sapphire substrates as well as the selective area growth to precisely control the nanostructure dimensions. Furthermore, we developed a technological process to contact InN nanopyramids and to integrate them into a high-frequency device layout. Thus, InN nanopyramid-based photodetectors exhibit a low R
C constant, low dark currents below 1 nA, as well as a high responsivity of about 0.2 A/W at a wavelength of 1.55 µm.
Laser Operation of Nitride Laser Diodes with GaN Well Layer in 340 nm Band
Authors: Kuwabara Masakazu , Yamashita Yoji , Torii Kousuke , Yoshida Harumasa
Published: May 2013

We have reported the laser operation of a short-wavelength ultraviolet laser diode with multiple quantum wells composed of GaN well layers. The GaN well-width is estimated to be around 1–1.5 nm. We have simulated whole laser-diode structure, and calculated wave-function overlap integrals. It is provided the integral becomes the maximum value in the well-width of 1.5 nm. The laser operation has been achieved in 340-nm-band under the pulsed current mode at room temperature. The wavelength is far from the wavelength corresponding to band gap of GaN, and the shortest lasing wavelength ever reported for a semiconductor laser composed of binary compound well layer. Moreover, the device has been realized on an Al0.2Ga0.8N underlying layer with 0.1 lower AlN mole fraction margin than that of a previous reported 342 nm laser-diode with an Al0.3Ga0.7N underlying layer. These results provide a chance to the next stage for a shorter-wavelength ultraviolet laser diode.
GaInN-Based Tunnel Junctions in n–p–n Light Emitting Diodes
Authors: Kaga Mitsuru , Morita Takatoshi , Kuwano Yuka , Yamashita Kouji , Yagi Kouta , Iwaya Motoaki , Takeuchi Tetsuya , Kamiyama Satoshi , Akasaki Isamu
Published: May 2013

We optimized p++-GaInN/n++-GaN tunnel junctions grown on conventional light-emitting diodes, corresponding to n–p–n structures. We investigated two dependences at the tunnel junctions, the InN mole fraction dependence and a doping dependence. The lowest voltage drop at the reverse-biased tunnel junction was 0.68 V at 20 mA with a 3 nm p++-Ga0.8In0.2N (Mg: 1×1020 cm-3)/30 nm n++-GaN (Si: 4×1020 cm-3) structure. We then found that the Mg memory effect was reasonably suppressed by using the p++-GaInN instead of a p++-GaN. At the same time, the amount of Si doping in the following n++-GaN should be substantially high to overcome the Mg memory effect.
Luminescence Properties of Eu-Doped GaN Grown on GaN Substrate
Authors: Wakamatsu Ryuta , Lee Dong-gun , Koizumi Atsushi , Dierolf Volkmar , Terai Yoshikazu , Fujiwara Yasufumi
Published: May 2013

We report a study on Eu the luminescence properties of Eu-doped GaN (GaN:Eu) grown on a GaN substrate by organometallic vapor phase epitaxy (OMVPE). Thermal quenching of the Eu luminescence was suppressed using the GaN substrate, which is due to the preferential formation of a Eu luminescent site with a local structure with high symmetry. The preferential formation of this luminescent site was supported by the observation of strong near-band-edge emission. The strong near band-edge emission occurred as a result of suppressed formation of the dominant Eu luminescent site in GaN:Eu on a sapphire substrate, which is known to be coupled with a defect and to have a large capture cross section of photogenerated carriers.
AlN-Capped AlInN/GaN High Electron Mobility Transistors with 4.5 W/mm Output Power at 40 GHz
Authors: Tirelli Stefano , Marti Diego , Lugani Lorenzo , Carlin Jean-François , Grandjean Nicolas , Bolognesi Colombo R.
Published: May 2013

We report the characterization of GaN high electron mobility transistors (HEMTs) using a new AlN-capped AlInN/GaN epilayer structure developed to achieve high current densities and reduced gate leakage currents. Devices with gate lengths of 75 and 200 nm and various and source–drain separations were fabricated simultaneously, allowing the selection of the most favorable configuration for power performance. We show that, as anticipated, aggressive scaling of source–drain spacing and gatelength does not benefit power performance because of early breakdown and more pronounced short-channel effects. For a non-field-plated 0.2 µm gate length in a 4 µm source–drain gap, the new epitaxial structure achieved a power density of 4.5 W/mm at 40 GHz. To the best of our knowledge, this is the highest power reported at 40 GHz for AlInN/GaN-based transistors, and the first report of the large-signal performance of an AlN-capped AlInN/GaN-based HEMT.
High-Temperature Characteristics in Recessed-Gate AlGaN/GaN Enhancement-Mode Heterostructure Field Effect Transistors with Enhanced-Barrier Structures
Authors: Maeda Narihiko , Hiroki Masanobu , Sasaki Satoshi , Harada Yuichi
Published: May 2013

Recessed-gate AlGaN/GaN enhancement-mode (E-mode) heterostructure field-effect transistors (HFETs) with enhanced-barrier structures were fabricated, and their high-temperature characteristics were examined. Owing to enhanced-barrier structures, where a thin AlGaN layer with a higher Al composition is inserted into the AlGaN barrier, excellent E-mode operation with threshold voltage (V
th) higher than +3 V and drain current density (I
d) higher than 600 mA/mm was obtained at room temperature. Interestingly, I
d did not decrease much at high temperatures, i.e., I
d decreased from 610 to 590 mA upon a temperature raise from RT to 300 °C. Open-gate devices with and without recessed-gate structures were fabricated and their two-terminal characteristics were comparatively examined, revealing that the observed peculiar characteristics are ascribed to recessed-gate structures. A model for explaining the observed high-temperature characteristics is proposed.
Reliability Evaluation of Al2O3 Deposited by Ozone-Based Atomic Layer Deposition on Dry-Etched n-Type GaN
Authors: Kikuta Daigo , Narita Tetsuo , Kutsuki Katsuhiro , Uesugi Tsutomu , Kachi Tetsu
Published: May 2013

The time-to-breakdown (t
BD) of Al2O3 deposited by ozone-based atomic layer deposition (ALD) on dry-etched n-type GaN was evaluated by constant-voltage-stress time-dependent dielectric breakdown (TDDB) measurements. The influence of dry etching was not observed in the TDDB and current–voltage (I–V) measurements at room temperature. The t
BD of the ALD-Al2O3 film was estimated to be more than 40,000 years at 3 MV/cm and room temperature. However, the t
BD estimated at 250 °C was around 102–103 s.
Metal–Oxide–Semiconductor Interface and Dielectric Properties of Atomic Layer Deposited SiO2 on GaN
Authors: Takashima Shinya , Li Zhongda , Chow T. Paul
Published: May 2013

The dielectric and MOS interface properties of SiO2 deposited with atomic layer deposition (ALD) on GaN with different surface treatments have been investigated with DC current–voltage (I–V) measurements and UV-assisted capacitance–voltage (C–V) measurements. Dielectric breakdown characteristics and leakage conduction mechanism for ALD SiO2 depend on surface conditions. Dry etch with NaOH post-etch GaN surface exhibited high oxide breakdown voltage with small distribution, larger barrier height characteristics, and higher charge to breakdown characteristics when compared with un-etched surface condition and dry etch with tetramethylammonium hydroxide (TMAH) post-etch surface condition. Moreover, fixed charge density and interface trap density at MOS interface extracted by UV-assisted C–V were comparable between un-etched surface sample and dry etch with NaOH post-etch surface sample, indicating dry etching damage recovery and demonstrating the usability of NaOH post-etching treatment. Comparison has also been made to a composite oxide of SiO2/Al2O3/SiO2, showing possibility of oxide charge engineering toward positive threshold voltage but carrier trapping by insertion of Al2O3.
Bedside Sonography for Detection of Postprocedure Pneumothorax
Authors: Shostak Eugene , Brylka Douglas , Krepp Joseph , Pua Bradley , Sanders Abraham
Published: May 2013

Objectives

Bedside sonography for diagnosis of pneumothorax has been well described in emergency and trauma medicine literature. Its role in detection of iatrogenic pneumothorax has not been well studied. We describe the performance of bedside sonography for detection of procedure‐related pneumothorax and highlight some limitations.

Methods

A total of 185 patients underwent thoracentesis (n = 60), transbronchial biopsy (n = 48), and computed tomography–guided needle lung biopsy (n = 77). Bedside preprocedure and postprocedure transthoracic sonography and postprocedure chest radiograph were performed in all patients. Patients in whom the pleural surface was not well imaged with sonography were said to have a limited examination. Chest radiography was the standard for diagnosing pneumothorax.

Results

Chest radiography showed pneumothorax in 8 of 185 patients (4.0%). These patients had undergone computed tomography–guided needle lung biopsy (n = 7) and transbronchial needle lung biopsy (n = 1). Sonography showed pneumothorax in 7 of these patients. The sensitivity, specificity, and diagnostic accuracy were 88%, 97%, and 97%, respectively. Limited‐quality sonographic examinations due to preexisting lung disease were seen in 43 of 185 patients. The positive and negative likelihood ratios for patients with adequate scans were 55 and 0.17, respectively. The likelihood ratio for patients with limited‐quality scans was 1.08.

Conclusions

When a good‐quality scan is achieved, bedside chest sonography is a valuable tool for evaluation of postprocedure pneumothorax. Patients with preexisting lung disease, in whom the quality of the sonographic examination is limited, should be studied with chest radiography.
Molecular and genomic aberrations in Chlamydophila psittaci negative ocular adnexal marginal zone lymphomas
Authors: Zhu Daxing , Ikpatt Offiong F. , Dubovy Sander R. , Lossos Chen , Natkunam Yasodha , Chapman‐Fredricks Jennifer R. , Fan Yao‐Shan , Lossos Izidore S.
Published: May 2013

The etiology and pathogenesis of ocular adnexal extranodal marginal zone lymphoma (OAEMZL) are still unknown and the association with Chlamydophila psittaci (C. psittaci) has been shown in only some geographic regions. Herein, we comprehensively examined the frequency of chromosomal translocations as well as CARD11, MYD88 (L265P), and A20 mutations/deletions in 45 C. psittaci negative OAEMZLs. t(14;18)(q32;q21) IGH‐MALT1 and t(11;18)(q21;q21) API2‐MALT1 were not detected in any of the analyzed tumors while three tumors harbored IGH translocations to an unidentified partner. CARD11 mutations were not found in all analyzed tumors, while the MYD88 L265P mutation was detected in three (6.7%) tumors. A20 mutations and deletions were each detected in seven (15.6%) and six (13.3%) tumors, respectively. Therefore, the observed genetic aberrations could account for the activation of the nuclear factor (NF)‐kB signaling pathway in only a minority of the cases. Further studies are needed to identify the molecular mechanisms underlying the pathogenesis of OAEMZL. Am. J. Hematol. 88:730–735, 2013. © 2013 Wiley Periodicals, Inc.
Distribution and characteristics of occupational injuries and diseases among farmers: A retrospective analysis of workers' compensation claims
Authors: Karttunen Janne P. , Rautiainen Risto H.
Published: May 2013

Background

Research indicates occupational injuries and diseases are not evenly distributed among workers. We investigated the distribution and characteristics of compensated occupational injuries and diseases requiring medical care in the Finnish farming population.

Methods

The study population consisted of 93,564 Finnish farmers, spouses, and salaried family members who were covered by the mandatory workers' compensation insurance in 2002. This population had a total of 133,207 occupational injuries and 9,148 occupational diseases over a 26‐year period (1982–2008).

Results

Clustering of claims was observed. Nearly half (47.1%) of the population had no compensated claims while 52.9% had at least one; 50.9% of farmers had one or more injuries and 8.1% had one or more diseases. Ten percent of the population had half of injury cases, and 3% of the population had half of occupational disease cases. Claims frequently involved work tasks related to animal husbandry and repair and maintenance of farm machinery. Injury and disease characteristics (work activity, cause, ICD‐10 code) differed between individuals with high and low personal claim rate. Injuries and diseases of the musculoskeletal system had a tendency to reoccur among those with high claim rate. These outcomes were often related to strenuous working motions and postures in labor‐intensive animal husbandry.

Conclusions

Analyses of longitudinal insurance data contributes to better understanding of the long‐term risk of occupational injury and disease among farmers. We suggest focusing on recurrent health outcomes and their causes among high risk populations could help design more effective interventions in agriculture and other industries. Am. J. Ind. Med. 56:856–869, 2013. © 2013 Wiley Periodicals, Inc.
Natural history and parental experience of children with trisomy 18 based on a questionnaire given to a Japanese trisomy 18 parental support group
Authors: Kosho Tomoki , Kuniba Hideo , Tanikawa Yuko , Hashimoto Yoko , Sakurai Hiroko
Published: May 2013

We conducted a questionnaire‐based study in collaboration with a Japanese trisomy 18 parental support group. Sixty‐five children (female, 68%) with full trisomy 18 were evaluated. Diagnosis was made prenatally in 17% (11/65) and 57% (37/65) were born following a cesarean. The mean gestational age at delivery was 38 weeks and 6 days, and the mean birth weight was 1,920 g (−2.6SD). A total of 51% (24/47) of children had apneic episodes. Thirteen children experienced generalized seizures, and a minority was seizure‐free with medication. Parents of 36% (18/50) of children were offered intensive treatment. A total of 45% (27/60) of children received intermittent mandatory ventilation, which was weaned off in half of them. Nine had surgeries, including esophageal atresia/omphalocele correction, cardiac surgery, and tracheostomy. A total of 15% (8/55) were fed fully orally, and 45% (29/64) were discharged home. Slow but constant psychomotor development was observed, and in four long‐term survivors over 10 years, two walked unassisted. Factors significantly associated with survival over 1 year included diagnosis after birth, absence of prematurity, heavier birth weight, absence of esophageal atresia, extubation, ability to feed orally without medical assistance, and home discharge. Parents appeared to be positive about caring for their children, and the children seemed to interact with parents and siblings as long as they lived, resulting in quality family time. The family point of view, as well as knowledge of natural history, should be considered when policy statements about the care of children with trisomy 18 are made. © 2013 Wiley Periodicals, Inc.
Design and synthesis of water‐soluble photosensitive α‐cyclodextrin and its application in dispersing carbon nanotubes
Authors: Liu Jingcheng , Liu Ren , Jiang Jinqiang , Liu Xiaoya
Published: May 2013

This manuscript describes the use of a novel water‐soluble photosensitive α‐cyclodextrin modified coumarin (α‐CD‐C) to disperse carbon nanotubes (CNTs) in water. First, using epichlorohydrin as the bridged unit, water‐soluble α‐cyclodextrin (α‐CD) was introduced to modify 7‐hydroxy‐4‐methylcoumarin and prepare α‐CD‐C. α‐CD‐C was characterized with hydrogen nuclear magnetic resonance spectra (1H‐NMR) and High pressure liquid chromatography‐mass spectrometry. The photodimerization experiment showed that α‐CD‐C could photodimerize upon 365 nm irradiation, and then photo‐de‐crosslink upon the subsequent 254 nm irradiation. Next, α‐CD‐C was used to disperse CNTs in water. Transmission electron microscope and scanning electron microscope demonstrated that α‐CD‐C effectively adsorbed onto the surface of CNTs. The α‐CD‐C is an efficient dispersant for CNTs. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 2588–2593, 2013
Active Mode Recognition of Switched Nonlinear Systems: Application to Fault Detection and Isolation
Authors: Zouari Talel , Pekpe Komi Midzodzi , Cocquempot Vincent , Ksouri Moufida
Published: May 2013

Robust switching detection and active mode recognition are addressed for switched nonlinear systems. The nonlinear modes are represented by Takagi‐Sugeno (TS) models where the weighting functions are supposed to be online computable. The proposed switching detection technique and the active mode recognition method lie on indicator signals that are generated using a data‐driven projection technique. The main advantage of this method is that it does not need the knowledge of local model parameter values. Only input‐output data and the weighting functions of the TS model are used to generate these indicator signals. A numerical example is provided to illustrate the proposed approach.
A semiparametric cure model for interval‐censored data
Authors: Lam Kwok Fai , Wong Kin Yau , Zhou Feifei
Published: May 2013

There is a growing interest in the analysis of survival data with a cured proportion particularly in tumor recurrences studies. Biologically, it is reasonable to assume that the recurrence time is mainly affected by the overall health condition of the patient that depends on some covariates such as age, sex, or treatment type received. We propose a semiparametric frailty‐Cox cure model to quantify the overall health condition of the patient by a covariate‐dependent frailty that has a discrete mass at zero to characterize the cured patients, and a positive continuous part to characterize the heterogeneous health conditions among the uncured patients. A multiple imputation estimation method is proposed for the right‐censored case, which is further extended to accommodate interval‐censored data. Simulation studies show that the performance of the proposed method is highly satisfactory. For illustration, the model is fitted to a set of right‐censored melanoma incidence data and a set of interval‐censored breast cosmesis data. Our analysis suggests that patients receiving treatment of radiotherapy with adjuvant chemotherapy have a significantly higher probability of breast retraction, but also a lower hazard rate of breast retraction among those patients who will eventually experience the event with similar health conditions. The interpretation is very different to those based on models without a cure component that the treatment of radiotherapy with adjuvant chemotherapy significantly increases the risk of breast retraction.