bluuebunny/crossref_metadata_2025_split huggingface dataset:
Short‐Term Visits and Tongan Livelihoods: Enterprise and Transnational Exchange
Authors: Cave Jenny , Koloto 'Ana Hau'alofa'ia 
Published: March 2015

AbstractA culture of migration and return is now part of everyday life in the Kingdom of Tonga, and transnational exchange relationships are crucial to the country's economy. Despite research on the impacts of remittances and other transnational exchange activities on livelihoods in Tonga and in migrant host countries, there has been little research on the interwoven dependencies and relationships amongst home, host, local, and diasporan nodes or the impact of short‐term visits in both directions. This paper explores dynamic processes within the agency of family‐linked economic and social practices of migrants and their descendants in host countries as well as their homelands. These activities are theorised within transnational contexts ‘from below’ (micro), ‘above’ (macro), ‘middling’ (meso), and ‘from above’ (macro) levels. The methodology, grounded in Pacific and Western ontologies, co‐creatively analyses the exchange and enterprise activities of families on a remote island of Tonga with high out‐migration, compared with their relatives in Auckland, New Zealand. Key findings are that short‐term visiting ensures the survival of a range of economic, social, and cultural activities that are critically important for ‘being Tongan’ in the different diasporan contexts. The originality of the research lies in retheorising enterprise alternatives for transnational Tongans, development of a Pacific‐framed view of transnational enterprise, and method that captures exchange complexities. The analysis fills a gap in knowledge regarding the impact of short visits on diasporan livelihoods, with implications for labour policy in home and diasporan locations to encourage youth to stay longer and older people to return sooner. Copyright © 2015 John Wiley & Sons, Ltd.
Power dependence of unusual bands in photoluminescence spectra of AlGaN/GaN heterostructures
Authors: Osinnykh I. V. , Zhuravlev K. S. , Malin T. V. 
Published: March 2015

AbstractAlGaN/GaN heterostructures with a two‐dimensional electron gas (2DEG) grown by metalorganic chemical vapor deposition (MOCVD) and molecular beam epitaxy (MBE) techniques were investigated by photoluminescence (PL) spectroscopy. Series of PL bands located below the donor bound excitons band have been observed for a high quality MOCVD sample. Two of these PL bands peaked at ħωmax=3.446 and ħωmax=3.423 eV have been observed at both continuous and pulse excitation and connected with the recombination of 2DEG localized at the first and the second levels in the quantum well with free holes. The PL band at ħωmax=3.36 eV may be attributed to recombination of the 2DEG electrons with holes located at acceptors. Band at ħωmax=3.41 eV is not connected with 2DEG because of this band didn’t disappear after etching of the AlGaN layer and this band was observed in all samples. An intensity of all these four PL bands increased superlinearly with rise of the excitation power. The exponents for the Y bands more than 2, while the exponent for the excitonic band is about 1.5 at T=5 K. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Minority carrier diffusion length in AlxGa1‐xN (x = 0.1) grown by ammonia molecular beam epitaxy
Authors: Malin Timur , Gilinsky Alexander , Mansurov Vladimir , Protasov Dmitriy , Yakimov Eugeny , Zhuravlev Konstantin 
Published: March 2015

AbstractThe room‐temperature minority carrier diffusion length in n ‐Al0.1Ga0.9N grown by ammonia molecular beam epitaxy on (0001) sapphire for photodetector applications has been investigated. The measurements were performed using the spectral dependence of the photocurrent detected by the built‐in p‐n ‐junction on thinner layer samples, and by the electron beam induced current technique on films of up to 2 µm in thickness. The results show that the hole diffusion length in n ‐AlGaN films amounts to 120‐150 nm, which is by 3‐4 times larger than that in GaN films grown under similar growth conditions. The thicker films do not show a considerable improvement in the hole diffusion length value. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Fabrication of transparent CuxZnyS/ZnS heterojunction diodes by photochemical deposition
Authors: Ichimura Masaya , Maeda Yosuke 
Published: March 2015

AbstractA CuxZnyS/ZnS transparent pn heterostructure was successfully fabricated by the photochemical deposition (PCD) from aqueous solutions. In PCD, the substrate was immersed in the solution to a depth of about 2‐3 mm from solution surface, and irradiated with the light of an ultra‐high‐pressure mercury arc‐lamp through a lens. The growth solution of CuxZnyS contained 5 mM CuSO4, 1 mM ZnSO4, 600 mM Na2S2O3, and 3 mM Na2SO3. The growth solution of ZnS contained 1 mM ZnSO4, 600 mM Na2S2O3, and 3 mM Na2SO3. p‐type conduction of CuxZnyS and n‐type conduction of ZnS were confirmed by the photoelectrochemical measurement. Both the films had high optical transmission (>70%) in the visible range. The CuxZnyS/annealed‐ZnS heterostructure showed rectification properties and photoresponse to AM1.5 irradiation. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
High‐performance AlGaN/AlN/GaN high electron mobility transistor with broad gate‐to‐source operation voltages
Authors: Tsai Jung‐Hui , Chiang Chung‐Cheng , Wang Fu‐Min 
Published: March 2015

AbstractIn this article, a high‐performance AlGaN/AlN/GaN high electron mobility transistor (HEMT) with broad gate‐to‐source operation voltages is fabricated and demonstrated. The experimental results exhibit a maximum extrinsic transconductance of 94.2 mS/mm at VGS = ‐2.58 V and a threshold voltage of ‐3.68 V at drain output current of 1 mA/mm.The insertion of an AlN interfacial layer can enhance the carrier confinement ability in channel and extend the gate operation voltage to +5 V. Furthermore, the effect of gate recess on device performance is investigated by two‐dimensional simulation. The simulated results show that the AlGaN/AlN/GaN HEMT with gate recess structure has higher equivalent Schottky barrier height, larger electron concentration in channel, larger drain output current and transconductance as compared with the device without gate recess structure. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Low‐temperature heteroepitaxial growth of InAlAs layers on ZnSnAs2/InP(001)
Authors: Oomae Hiroto , Suzuki Akiko , Toyota Hideyuki , Nakamura Shin'ichi , Uchitomi Naotaka 
Published: March 2015

AbstractWe studied the epitaxial growth of InAlAs on ZnSnAs2 thin films to establish magnetic heterostructures involving ferromagnetic Mn‐doped ZnSnAs2 (ZnSnAs2:Mn) thin films. These heterostructures were successfully grown at temperatures around 300 °C to maintain room‐temperature ferromagnetism in ZnSnAs2:Mn. Reflection high‐energy electron diffraction, X‐ray diffraction measurements and cross‐sectional transmission electron microscopy revealed that the InAlAs layers were pseudomorphically lattice‐matched with ZnSnAs2, even at the low temperature of 300 °C. We attempted to prepare magnetic quantum well structures from the InAlAs/ZnSnAs2:Mn magnetic multilayer structure. We found that InAlAs layers heteroepitaxially grown on ZnSnAs2 and ferromagnetic ZnSnAs2:Mn films are suitable for preparing InP‐based magnetic semiconductor quantum structures. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Electronic structure of BaFeO3 studied by X‐ray spectroscopy
Authors: Mizumaki Masaichiro , Fujii Hitoshi , Yoshii Kenji , Hayashi Naoaki , Saito Takashi , Shimakawa Yuichi , Uozumi Takayuki , Takano Mikio 
Published: March 2015

AbstractWe investigated the electronic structure of BaFeO3 by using HAXPES and XAS measurements and first principle studies. The experimental and theoretical results indicated that BaFeO3 is a negative charge transfer compound. We concluded that the on‐site Coulomb energy and the strong hybridization between Fe‐3d and O‐2p orbitals play a very important role of emergence of negative charge transfer. And we found the new structure in the Fe‐2p XPS spectrum and concluded this structure is originated from non‐local screening. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Deposition of Cl‐doped CdTe polycrystalline films by close‐spaced sublimation
Authors: Okamoto Tamotsu , Takahashi Kohei , Akiba Sho , Yasuda Nao , Tokuda Satoshi , Kishihara Hiroyuki , Ichioka Akina , Doki Takahiro , Sato Toshiyuki 
Published: March 2015

AbstractThe effects of Cl‐doping on the CdTe layers by the close‐spaced sublimation (CSS) deposition were investigated. Cl‐doped CdTe polycrystalline films were deposited on graphite substrates by CSS method using a mixture of CdTe and CdCl2 powder as a source. In X‐ray diffraction (XRD) patterns of the obtained films with various deposition times, many diffraction peaks other than CdTe peaks were observed in the deposition times lower than 10 min. These diffraction peaks were probably due to the formation of chlorides of Cd, Te and C, such as CdCl2, TeCl4, Te3Cl2 and C10Cl8. X‐ray fluorescence (XRF) and secondary ion mass spectrometry (SIMS) analyses revealed that a large amount of chlorine was contained in the films with the deposition times lower than 10 min, and that Cl concentration decreased with increasing the deposition time above 3 min. These results indicate that the films containing the chlorides of Cd, Te and C in addition to CdTe are formed in the initial stage of the CSS deposition using a mixture of CdTe and CdCl2 powder as a source. Cross‐sectional images revealed that the grain size was decreased by the effect of Cl‐doping. Furthermore, current‐voltage (I ‐V) characteristics of the CdTe/graphite structures were measured, and it was found that the resistivity of the Cl‐doped CdTe layer was much higher than that of the undoped CdTe layer. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A mild hydrothermal route to synthesis of CZTS nanoparticle inks for solar cell applications
Authors: Vanalakar S. A. , Agwane G. L. , Gang M. G. , Patil P. S. , Kim J. H. , Kim J. Y. 
Published: March 2015

AbstractCu2ZnSnS4 (CZTS) is a promising thin film absorber material for low cost solar cell applications. Its absorption coefficient (∼ 104 cm‐1), crystal structure and band gap energies (∼1.5 eV) are similar to those of Cu(In,Ga)Se2 (CIGS), one of the most studied and flourishing thin film solar cell absorber materials. However, unlike CIGS, which requires the expensive and rare elements; In and Ga, CZTS is composed of reasonably priced and abundant elements like Zn and Sn. In the present investigation, kesterite CZTS nanoparticle inks were obtained by a hydrothermal process using Cu, Zn and Sn chlorides, and Na sulfide. The synthesized CZTS nanoparticles were characterized using optical absorption, X‐ray powder diffraction (XRD), energy dispersive spectroscopy (EDS), micro‐Raman spectroscopy, high‐resolution transmission electron microscopy (HRTEM), and X‐ray photoelectron spectroscopy (XPS). The optical and morphological properties demonstrated that the prepared nanoparticles have strong absorption in 300−550 nm range with band gap energy of 1.55 eV with an average particle size of 20 nm. The X‐ray and micro‐Raman analysis revealed that the synthesized CZTS nanoparticles have the phase pure kesterite structure. We believe that our synthetic method will be helpful for low‐cost and efficient thin film photovoltaic technology. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Effect of supercritical carbon dioxide treatment on the polarons of HCl‐doped polyaniline films
Authors: Fernando J. G. , Vequizo R. M. , Odarve M. K. G. , Sambo B. R. B. , Malaluan R. M. , Malaluan L. A. M. 
Published: March 2015

AbstractIn situ HCl‐doped polyaniline films were synthesized on glass substrates via chemical oxidative polymerization of aniline using ammonium peroxydisulfate as oxidant. The films were treated with supercritical carbon dioxide (SC‐CO2) at 30 MPa and 40 °C for 30 minutes. The physico‐chemical and electrical properties of the films were determined to establish the effect of supercritical carbon dioxide treatment on the polaron structures of polyaniline films. The treatment removed limited number of polarons which affected the properties of polyaniline. The treated films remained conducting despite that the conductance decreased substantially. The treatment enhanced the quinoid character of the films and altered the HOMO‐LUMO transitions. In addition, SC‐CO2 treatment was unable to remove the PANI precipitations adhering on the surface of the films. A mechanism on the effect of SC‐CO2 interaction to HCl‐doped PANI films was proposed. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Fabrication of Cu2ZnSnSe4 thin films by selenization of precursor using Cu2ZnSnSe4 compound for photovoltaic applications
Authors: Nakashima M. , Yamaguchi T. , Kusumoto K. , Yukawa S. , Sasano J. , Izaki M. 
Published: March 2015

AbstractCu2ZnSnSe4 ingot was synthesized and then used it and Na2Se powder as evaporation materials to prepare a precursor for selenization process in order to fabricate Cu2ZnSnSe4 thin films for solar cell applications. From EPMA analysis, the Sn content in the thin films was approximately constant with increasing Sn mole ratio and the Se content was under 50 at.% in the first experiment. The Se content in the thin films increased to around 50 at.% by the addition of Se layer in second experiment. XRD study showed that the thin films had a kesterite phase in Cu2ZnSnSe4. The Se layer addition enhanced to grow thin films having a close‐packed structure and columnar grains. Cu2ZnSnSe4 thin film solar cells demonstrated Voc= 282 mV, Isc= 3.00 mA/cm2. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Crystallization mechanism of sol‐gel synthesized spinel LiMn2O4
Authors: Kushida K. , Kuriyama K. 
Published: March 2015

AbstractCrystallization mechanism of sol‐gel synthesized spinel LiMn2O4 is studied by a differential scanning calorimetry (DSC) method. Lithium acetate and manganese acetate are dissolved in methanol in the atomic ratio of 1:2 (Li:Mn) with citric acid as a chelating agent, leading to a sol solution. A Li‐Mn gel precursor is obtained by partly evaporating the sol solution. A large exothermic reaction of the Li‐Mn gel starts at 280 °C, indicating that the combustions of C and H atoms released from the gel occur above 280 °C. After the rise in temperature to 290 °C, the exothermic reaction of the gel continues at the constant temperature of 290 °C, indicating that the rearrangement of Li, Mn and O atoms for the crystallization into the spinel structure mainly occurs at 290 °C. This suggests that annealing the Li‐Mn gel precursor above 290 °C is necessary to obtain spinel LiMn2O4. During the exothermic reaction, Mn atoms released from the gel occupy the octahedral sites in the spinel framework of O, and Li atoms also released are inserted into the tetrahedral sites. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Bulk crystal growth and characterization of ZnSnP2 compound semiconductor by flux method
Authors: Nakatsuka Shigeru , Nakamoto Hiroshi , Nose Yoshitaro , Uda Tetsuya , Shirai Yasuharu 
Published: March 2015

AbstractZnSnP2 is a promising candidate for solar absorber materials from the viewpoint of high absorption and earth‐abundant constitution elements. In this paper, we fabricated ZnSnP2 crystals by flux method based on the phase diagram of Sn‐ZnP2 pseudo‐binary system and investigated their properties for an application to photovoltaics. The crystal growth experiments with the cooling rate of 0.7 and 12 °C/h were carried out and we successfully obtained ZnSnP2 crystals with the diameter of 8mm and the thickness of a few mm by a slow cooling rate. The structure of grown crystals studied by X‐ray diffraction was indicated to be chalcopyrite‐type ZnSnP2. In addition, the decrease of the degree of order was observed with the increase of cooling rate. The lattice constants of a and c axes are 5.649 and 11.295 Å, respectively. The composition of grown crystals is a near stoichiometric ratio of ZnSnP2 by EDX analysis. The bandgaps of ZnSnP2 crystals obtained by cooling rate of 0.7 and 12 °C/h were estimated to be 1.61 and 1.48 eV, respectively, which is caused by the difference of the degree of order. The hall‐resistivity measurement showed that ZnSnP2 crystals with a slow cooling rate has a p‐type conduction. The resistivity, the hole concentration and the mobility are 10∼70 Ωcm, 6·1016∼2·1017 cm‐3, and 1∼3 cm2V‐1s‐1. The obtained properties are suitable for an absorber of photovoltaics. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Growth and characteristics of amorphous silica‐modified polyaniline films for ammonia sensor application
Authors: Odarve Majvell Kay , Vequizo Reynaldo 
Published: March 2015

AbstractThe characteristic properties of the nanostructured polyaniline (PAni) films synthesized via chemical oxidative polymerization of aniline on glass substrates using amorphous cristobalite silica (SiO2) as structural growth director are presented in this study. The change in the resistance of the sample was monitored upon exposure to ammonia gas using two‐probe method for two cycles, 40 min each. The structural and morphological property of the PAni/SiO2 samples were studied and compared to PAni samples alone using FTIR spectroscopy and scanning electron microscopy. It was found out that PAni/SiO2 films have higher and uniform response to ammonia with good repeatability during the two cycles and recovery upon removal of ammonia source. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Structure and optical properties of CdS:O films by cathode sputtering
Authors: Nakajima Masahiro , Asaba Ryo , Suzuki Akinori , Shim Yong‐Gu , Wakita Kazuki , Khalilova Kh. , Mamedov Nazim , Bayramov Ayaz , Huseynov Emil 
Published: March 2015

AbstractWe have studied the structure and optical properties of CdS:O films deposited on SLG (soda lime glass) substrates by cathode sputtering in the atmosphere of oxygen/argon gases. According to X‐ray diffraction (XRD) and confocal Raman scattering data, the films annealed in vacuum at temperatures above 300 °C exhibited crystalline structure of CdS. On the other hand, XRD, confocal Raman scattering, AFM (atomic force microscopy) and TEM (transmission electron microscopy) data indicated amorphous structure nano‐crystallization in CdS:O films annealed in vacuum at 400 °C. For the films, the emissions located at 3.35 eV were evident from photoluminescence measurements. The origin of this energy gap is discussed by taking into account redistribution of electronic density of states in the amorphous phase and quantum‐size effect. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Excitonic emission on CuInS2 epitaxial films by pulse laser deposition
Authors: Yoshida Ryo , Po‐Han Tseng , Shim Yong‐Gu , Wakita Kazuki 
Published: March 2015

AbstractThin films of epitaxial CuInS2 were deposited on a GaAs substrate at a temperature of 500 ºC by the pulse‐laser‐deposition method. Surface and cross‐section scanning electron microscopy (SEM) images were taken for all the films, with thicknesses estimated to range between 0.5‐1 μm. X‐ray diffraction (XRD) and Raman scattering confirmed the chalcopyrite structure of the films. For a film deposited by a pulse of energy density 0.8 J/cm2, free exciton and bound exciton emissions at 77 K were observed using photoluminescence (PL). The exciton emissions appear only at specific points in a PL‐intensity mapping. In addition, for the points with excitonic emission the composition ratio of the Cu and In was found to be very close to unity compared to other areas without emissions. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
High‐performance a‐Si1–xOx:H/c‐Si heterojunction solar cells realized by the a‐Si:H/a‐Si1–xOx:H stack buffer layer
Authors: Zhang He , Nakada Kazuyoshi , Miyajima Shinsuke , Konagai Makoto 
Published: March 2015

We used amorphous silicon oxide (a‐Si1–xOx:H) and microcrystalline silicon oxide (µc‐Si1–xOx:H) as buffer layer and p‐type emitter layer, respectively, in n‐type silicon hetero‐junction (SHJ) solar cells. We proposed to insert a thin (2 nm) intrinsic amorphous silicon (a‐Si:H) thin film between the thin (2.5 nm) a‐Si1–xOx:H buffer layer and the p‐layer to form a stack buffer layer of a‐Si:H/a‐Si1–xOx:H. As a result, a high open‐circuit voltage (VOC) and a high fill factor (FF) were obtained at the same time. Finally, a high efficiency of 19.0% (JSC = 33.46 mA/cm2, VOC = 738 mV, FF = 77.0%) was achieved on a 100 μm thick polished wafer using the stack buffer layer.
magnified image(© 2015 WILEY‐VCH Verlag GmbH &Co. KGaA, Weinheim)
Polymyxin‐B‐immobilized‐fiber column hemoperfusion with oseltamivir treatment for ARDS due to influenza H1N1/09
Authors: Binh Nguyen Gia , Manabe Toshie , Co Dao Xuan , Tuan Nguyen Dang , Thach Pham The , Kudo Koichiro 
Published: March 2015

AbstractAcute respiratory distress syndrome (ARDS) is one of the severe complications of influenza H1N1/09 infection, resulting in high mortality. Effective treatment strategies for ARDS are needed. This report presents two cases of ARDS due to influenza in Vietnam. Both cases were similar in terms of starting symptoms, the rapid progression to ARDS, and the treatment strategy, direct hemoperfusion with a polymyxin‐B‐immobilized fiber column (PMX‐DHP) and oseltamivir. However, the clinical course of disease and the outcomes were different. For case 1, treatment was initiated on day 4 following the onset of hypoxemia due to ARDS. Symptoms improved rapidly after treatment and the patient was discharged on day 12. For case 2, treatment was initiated on day 9 after the onset of symptoms. Despite intensive therapy, the patient died on day 18. In conclusion, treatment with PMX‐DHP and oseltamivir is effective on ARDS due to influenza but only if initiated early.
Introducing robotic surgery into an endometrial cancer service–a prospective evaluation of clinical and economic outcomes in a UK institution
Authors: Ind Thomas E. J. , Marshall Chris , Hacking Matthew , Harris Michelle , Bishop Liz , Barton Desmond , Bridges Jane E. , Shepherd John H. , Nobbenhuis Marielle 
Published: March 2015

AbstractBackgroundWe have assessed how the introduction of robotics in a publicly funded endometrial cancer service affects clinical and economic outcomes.MethodsThe study included 196 women. Costs were divided into those for wards, high dependency, staffing, theatres, pharmacy, blood products, imaging, pathology and rehabilitation. Capital depreciation was included.ResultsPrior to the introduction of robotics, 78/130 (60.0%) cases were performed open, compared to 17/66 (25.8%) afterwards ( p < 0.0001). The median operative time increased 37 min (95% CI 17–55 min; p = 0.0002); the median blood loss was 55 ml lower (95% CI 0–150 ml; p = 0.0181); the stay was 2 days shorter (95% CI 1–3; p < 0.0001). Complications reduced from 64/130 (49.2%) to 19/66 (28.8%) ( p = 0.0045). Costs reduced from £11 476 to £10 274 ( p = 0.0065). Conversions for 'straight stick' surgery were 18.2% (14/77) compared to 0.0% (0/24) for robotics ( p = 0.0164).ConclusionsIntroducing robotics resulted in fewer laparotomies, shorter stays, fewer complications and lower costs. © 2015 The Authors. The International Journal of Medical Robotics and Computer Assisted Surgery Published by John Wiley & Sons Ltd.