bluuebunny/crossref_metadata_2025 huggingface dataset:
New estimates of Arctic and Antarctic sea ice extent during September 1964 from recovered Nimbus I satellite imagery
Authors: Meier W. N. , Gallaher D. , Campbell G. G.
Published: April 2013

Abstract. Visible satellite imagery from the 1964 Nimbus I satellite has been recovered, digitized, and processed to estimate Arctic and Antarctic sea ice extent for September 1964. September is the month when the Arctic sea ice reaches its minimum annual extent and the Antarctic sea ice reaches its maximum. Images from a three-week period were manually analyzed to estimate the location of the ice edge and then composited to obtain a hemispheric estimate. Uncertainties were based on limitations in the image analysis and the variation of the ice cover over the three-week period. The 1964 Antarctic extent is higher than estimates from the 1979–present passive microwave record, but is in accord with previous indications of higher extents during the 1960s. The Arctic 1964 extent is near the 1979–2000 average from the passive microwave record, suggesting relatively stable summer extents during the 1960s and 1970s preceding the downward trend since 1979 and particularly the large decrease in the last decade. These early satellite data put the recently observed record into a longer-term context.
¿Son necesarias políticas públicas sobre la biblioteca escolar? Situación en América Latina
Authors: Cárdenas Zardoni Horacio
Published: April 2013

La biblioteca escolar es uno de los recursos de mayor relevancia para para elevar el aprovechamiento de los educandos inscritos en el sistema educativo de cualquier nación. Todo país invierte cantidades sustanciales en recursos bibliotecarios para las escuelas, los cuales tienen la cualidad de permanecer e irse acumulando, con lo que al paso de los años la biblioteca escolar puede llegar a tener un importante acervo que poner al servicio de los estudiantes. Pese a su  valor innegable como coadyuvante en la formación de millones de ciudadanos que cursan sus estudios en las escuelas latinoamericanas, sin embargo su capacidad instalada y su potencial  distan mucho de ser capitalizado al máximo. La razón de esto es la inexistencia de políticas públicas que dispongan su plena incorporación al proceso enseñanza-aprendizaje.
Bibliotecas digitales universitarias en España y TIC como paradigmas de las necesidades de información para docentes y discentes
Authors: Oliva Marañón Carlos
Published: April 2013

Las bibliotecas digitales universitarias han experimentado un avance durante los últimos años, lo que facilita la recuperación de información en distintos soportes. Los objetivos de esta investigación son verificar la idoneidad de los catálogos online para satisfacer las necesidades de información de docentes y discentes en el área de Biblioteconomía y Documentación mediante la evaluación de una muestra de 23 bibliotecas digitales universitarias; y plantear las mejoras necesarias. Los resultados constatan la idoneidad de los catálogos online para solventar las necesidades informativas de profesores, investigadores y alumnos, siendo las bibliotecas de las Universidades de Barcelona, Granada y Sevilla las más relevantes en el área de Documentación; así como la profesionalidad del bibliotecario para atender las necesidades de los usuarios. Entre otras mejoras, se plantean la formación del profesorado y del alumnado en el uso de los recursos electrónicos; y la creación de ayudas en línea para perfeccionar las interfaces usuario-web con la finalidad de recuperar la información de forma rápida y eficaz.
Recordando a Martha Cajías: Homenaje de la Revista de Estudios Bolivianos a una tejedora
Authors: Editors BSJ
Published: April 2013

[This is a literary homage and therefore has no abstract]
Convocatoria
Authors: Convocatoria BSJ
Published: April 2013

Convocatoria / Call for papers
Association of Cytokines, High Sensitive C-Reactive Protein, VEGF and Beta-Defensin-1 Gene Polymorphisms and Their Protein Expressions with Chronic Periodontitis in the Chinese Population
Authors: Tian Ye , Li Jin-le , Hao Liang , Yue Yuan , Wang Min , Loo Wings TY , Cheung Mary NB , Chow Louis WC , Liu Qing , Yip Adrian YS , Ng Elizabeth LY , Chow Christopher YC
Published: April 2013

Purposes

This study aimed at investigating the association between interleukin-6 (IL-6), interleukin-12 (IL-12), C-reactive protein (CRP), vascular endothelial growth factor (VEGF) and β-defensin-1 polymorphisms and the susceptibility to periodontitis in the Chinese population.

Methods

DNA was extracted from the blood samples of 532 healthy individuals and 122 chronic periodontitis (CP) patients enrolled in the study. The genes encoding IL-6, IL-12, CRP, VEGF and β-defensin-1 were amplified using PCR and digested with restriction enzymes. The protein expression of the abovementioned genes was determined by ELISA. Differences in the allele/genotype frequencies were assessed with the chi-square test.

Results

The frequencies of the C/C genotypes of IL-6, IL-12, and VEGF were higher in CP patients than healthy controls (66.3% vs 25.9%; 27.8% vs 19.9%; and 64.8% vs 52.1%, respectively). In the patients' group we also recorded frequencies of the A/A genotypes of CRP and VEGF higher than in healthy controls (63.1% vs 58.1% and 64.8% vs 35.2%, respectively). Protein production evaluated by ELISA demonstrated significant differences between CP patients and healthy controls for IL-6, IL-12, CRP, VEGF and β-defensin-1.

Conclusions

The genotypes of IL-6, IL-12, VEGF and β-defensin-1 and their protein productions were associated with CP in a Chinese population. Genotypes and serum levels of CRP were associated with CP, but alleles frequency showed no difference between CP patients and healthy controls.
A New Monitor to Measure Dermal Blood Flow in Critically Ill Patients: A Preliminary Study
Authors: Cohen Jonathan , Skoletsky Ilya , Chen Rina , Weiss Daniel , Singer Pierre
Published: April 2013

Background. Conditions of reduced perfusion are characterized by redistribution of blood flow away from the skin to more vital organs. Objectives. To assess the efficacy of a noninvasive, dermal blood flow (DBF) monitor in detecting changes in perfusion in critically ill patients. Methods. Eleven adult, critically ill patients in a general ICU were studied. DBF, finger plethysmography, and invasive mean arterial pressure (MAP) were recorded over an 8-hour period. DBF was measured using the DermaFlow DBF monitor via a skin probe placed on the anterior chest wall. Sensitivity was evaluated by visual inspection during active states, either induced, for example, fluid administration, or spontaneous, for example, altered hemodynamics, while specificity was evaluated during stable states. Data are expressed in terms of standard deviation of the difference (SDD) between the MAP and each of the tested methods. Results. The DBF detected all true changes detected by MAP while plethysmography detected fewer of these events. Based on SDD, the specificity of the DBF was found to be better than that of plethysmography and close in value to the MAP. Conclusions. This preliminary study suggests that the DBF monitor may be a useful noninvasive method for detecting changes in perfusion in critically ill patients.
3-Pyrenylacrylates: Synthetic, Photophysical, Theoretical and Electrochemical Investigations
Authors: Reimann Sebastian , Sharif Muhammad , Wittler Kai , Knöpke Leif R. , Surkus Annette-E. , Roth Christian , Ludwig Ralf , Langer Peter
Published: April 2013

The Mizoroki-Heck coupling of 1-bromopyrene with acrylates provides a convenient access to a variety of 3-pyrenylacrylates in very good yields (up to 93%). Their photophysical properties combined with solvatochromic effects were studied. In addition, electrochemical oxidation potentials were determined by DPV (differential pulse voltammetry) measurements. The fine structure of the absorbance spectra obtained from photophysical measurements are compared with the results of theoretical calculations performed by time dependent TD-B3LYP methods using the 6-31G* basis set.
Mixed Linker Strategy for the Construction of a Fluorescent 2D Network Based on [Ag2(COO)2] as Secondary Building Unit
Authors: Sun Di , Yuan Shuai , Liu Shan-Shan , Zhao Ya-Qin , Han Lu-Lu , Wang Xing-Po
Published: April 2013

The ultrasound-assisted reaction of AgNO3, 2-amino-4,6-dimethylpyrimidine (dmapym) and 2,6-naphthalenedicarboxylic acid (H2npd) gave rise to a new 2D network of the formula [Ag2(dmapym)2(npd)]n (1). The atoms Ag1 and Ag2 in the complex show seesaw and distorted tetrahedral coordination geometries, respectively. The dmapym ligand acts as a bidentate bridge to bind paired Ag(I) ions into a chain. The chains are further connected by npd linkers to form the resultant 2D network reinforced by N-H···O hydrogen bonds between dmapym and npd. Weak C-H···p interactions are also found in the crystal structure. Complex 1 exhibits photoluminescence in the solid state at room temperature with an emission maximum at 418 nm upon excitation at 330 nm.
Synthesis, Crystal Structure and Properties of a Chiral 2D Zn(II) Coordination Polymer with Helical Chains
Authors: Kang Ting-Ting , Tang Hao , Wei Yong-Li , Zang Shuang-Quan
Published: April 2013

A chiral two-dimensional (2D) coordination polymer {[Zn(cmmb)(1,4-bbi)]·H2O}n (1) has been synthesized by a hydrothermal reaction of Zn(NO3)2·6H2O with 4- (carboxymethoxy)-2-methylbenzoic acid (H2cmmb) and 1,1`-(1,4-butanediyl)bis(imidazole) (1,4-bbi). It has been characterized by elemental analysis, X-ray crystallography, IR spectroscopy and thermogravimetry, and also by its fluorescence properties. The metal-organic layer of the complex is held together with its neighbors via C-H···O hydrogen bonds to give rise to a chiral three-dimensional supramolecular network.
Hydrothermal Synthesis and Crystal Structure of a Meso-Helical Chain Based on Lindqvist Polyoxometalates
Authors: Zhang Chun-Jing , Fang Rui , Yu Yan , Pang Hai-Jun , Ma Hui-Yuan , Cui De-Sheng , Li Dong-Ping
Published: April 2013

A new Lindqvist polyoxometalate-based hybrid compound with a helical chain structure, [Cu(bipy)2][W6O19] (1), (bipy = 2;20`-bipyridine), has been hydrothermally synthesized and characterized by elemental analysis, infrared spectroscopy, thermogravimetry, and single-crystal X-ray diffraction. The compound crystallizes in the space group C2/c of the monoclinic system. In 1, the [W6O19]2- anions are connected alternately with [Cu(bipy)2]2+ subunits to form a meso-helical chain. To our knowledge, this structure represents the first example of a helical chain structure consisting of the hexatungstate anion [W6O19]2-. The electrochemical properties of the title compound have been studied.
Synthesis of 1,4-Disubstituted 1,2,3-Triazoles from Aromatic a-Bromoketones, Sodium Azide and Terminal Acetylenes via Cu/Cu(OTf)2-catalyzed Click Reaction under Microwave Irradiation
Authors: Fazeli Azadeh , Oskooie Hossein A. , Beheshtiha Yahya S. , Heravi Majid M. , Moghaddam Firouz Matloubi , Foroushani Behzad Koushki
Published: April 2013

Reaction of aromatic a-bromoketones, sodium azide and aromatic or aliphatic terminal acetylenes in the presence of Cu/Cu(OTf)2 following the classical method (aqueous acetonitrile at room temperature) and under microwave irradiation (H2O at 85 °C) leads to 1,4-disubstituted 1,2,3-triazoles as the final products after simple filtration.
Illicit Drug Use Initiation in the Nordic Countries
Authors: Moeller Kim
Published: April 2013

Abstract: The aim of this review is to provide an overview of the most important research into young people's initiation of illicit drug use in the Nordic countries. A systematic literature review was undertaken in Sweden, Denmark, Norway, combined with a qualified search in Finland and Iceland. The search was based on the PubMed and Sociological Abstracts databases in combination with Google Scholar. A total of 333 documents were reviewed, primarily English peer-reviewed articles, but also reports and books in the Nordic languages. 46 documents were chosen to represent the research into illicit drug initiation in the Nordic countries. The review has two parts. In the first part the typical drug initiation sequence and the different interpretations of this sequence in the Nordic countries is presented. In the second part four categories of risk factors are identified, and a review of the most significant Nordic research into these is presented. The categories are: parenting styles, emotional control, sensation-seeking behaviour, collective identity-creation processes, and risk perceptions.
La Compagnie de la pêche sédentaire en Acadie, 1682–1708
Authors: Landry Nicolas
Published: April 2013

Traditionnellement, l’historiographie acadienne du régime français a eu tendance à négliger l’étude des structures économiques. Sous prétexte que des entrepreneurs comme Nicolas Denys et la Compagnie de la pêche sédentaire en Acadie firent faillite, on a rapidement conclu que cela était attribuable à de la mauvaise gestion ou à des conflits de personnalités. Or, comme pour d’autres cas dans l’histoire de la Nouvelle-France, il faut plutôt s’intéresser aux forces qui s’opposaient à ces entreprises pour mieux comprendre les causes de leurs difficultés. Dans le cas qui nous intéresse, la Compagnie de la pêche sédentaire en Acadie doit sans cesse se défendre contre les attaques d’administrateurs coloniaux français les percevant comme des compétiteurs commerciaux ou encore contre les attaques anglaises.
Les Acadiens à Halifax et dans l’île Georges, 1755–1764
Authors: LeBlanc Ronnie-Gilles
Published: April 2013

L’île Georges, sise dans le havre d’Halifax, a servi de lieu de détention pour des centaines d’Acadiennes et d’Acadiens durant l’époque de la Déportation, de 1755 à 1762. Parmi les premiers prisonniers détenus dans l’île figurent les députés acadiens qui ont refusé de prêter un serment inconditionnel devant le conseil du gouverneur, en juillet 1755. Peu après leur départ, une cinquantaine de personnes de Mirligouèche ou Lunenburg sont déportées en Caroline du Nord à partir de l’île, en novembre 1755. Ce sera la première de deux déportations en provenance de l’île, car des familles de la région de Cap-Sable et de la rivière Saint-Jean y seront gardées prisonnières en attendant leur déplacement forcé en novembre 1759. Une autre déportation, celle de 1762, se fera à partir de la ville d’Halifax même et elle comprendra plus de 900 personnes, pour la plupart des familles qui ont échappé à la déportation et qui ont offert une farouche résistance aux troupes britanniques entre 1755 et 1760. Enfin, à compter de novembre 1764, des centaines d’Acadiennes et d’Acadiens quitteront Halifax pour une vie meilleure en Louisiane, alors que d’autres y demeureront encore quelque temps avant de s’établir un peu partout dans la région atlantique.
Mémoires acadiennes de la Déportation
Authors: Viau Robert
Published: April 2013

La Déportation est l’événement capital de l’histoire de l’Acadie — un événement qui a marqué et qui continue de marquer la culture et la société acadiennes. Dans cet article, l’auteur examine les mémoires acadiennes de la Déportation telles qu’elles se sont manifestées lors des commémorations de 1930, de 1955 et de 2005 et lors de la querelle des « excuses de la Reine ». Il examine aussi la question : « Pourquoi se souvenir? » Évoquer la Déportation ne sert-il qu’à entretenir la victimisation des Acadiens et le sentiment tragique de leur existence en tant que peuple dépossédé? Au contraire, avoir une conscience historique ne signifie-t-il pas se percevoir dans une continuité, dans un projet? Le débat entourant la Déportation est loin d’être clos et que ce soit dans les romans récents, dans les manuels d’histoire ou lors des commémorations, le sujet demeure d’actualité.
L’utilisation des Tic par les PME dans les régions rurales francophones du sud-ouest de la Nouvelle-Écosse : étude exploratoire
Authors: Blinn Dianne , Sangaré Yalla
Published: April 2013

À l’instar de la plupart des régions rurales du Canada atlantique, le sud-ouest de la Nouvelle-Écosse fait face à des défis économiques importants. Au-delà du déclin démographique, il y a consensus pour dire que cette région doit progressivement passer d’une économie basée sur l’exploitation des matières premières et des ressources naturelles à une économie basée sur les services et le savoir. Dans quelles mesures les francophones du sud-ouest de la Nouvelle-Écosse s’adaptent-ils aux changements structurels dans l’environnement économique? L’objet de cet article est de voir quelle utilisation les entreprises francophones de cette région font des technologies de l’information et de la communication (Tic) à partir d’un sondage réalisé auprès des dirigeants et entrepreneurs. La principale conclusion de cette étude est que les entreprises ont pris le virage des Tic, mais elles ne les utilisent pas à leur plein potentiel.
Traduire Winslow
Authors: Clarke Patrick D.
Published: April 2013

Ce qui suit est le texte d’une allocution prononcée à l’Université de Moncton, en février 2011, dans le cadre des « Jeudis de la Librairie acadienne » (en collaboration avec le Groupe de recherche interdisciplinaire sur les cultures en contact), qui ont pour but de commenter un ouvrage jugé important et ce, en présence de l’auteur.
Des recherches patrimoniales à échelle réduite : l’avenir de Parcs Canada
Authors: Lavoie Marc
Published: April 2013

Au cours des derniers mois, le gouvernement fédéral a sabré dans les effectifs de nombreux ministères, surtout en ce qui a trait à la recherche. À Parcs Canada, le nombre de chercheurs a été réduit de beaucoup. Or il s’avère que les archéologues, les conservateurs et les historiens au service du gouvernement fédéral croulaient déjà sous une montagne de travail. Il faut se demander comment ceux qui ont survécu à ces coupures pourront poursuivre leurs recherches et répondre aux demandes à jamais croissantes du public pour des informations sur les sites patrimoniaux au pays.
Characterization of Random Telegraph Noise Generated by Process- and Cycling-Stress-Induced Traps in 26 nm NAND Flash Memory
Authors: Jo Bong-Su , Kang Ho-Jung , Joe Sung-Min , Jeong Min-Kyu , Han Kyung-Rok , Park Sung-Kye , Park Byung-Gook , Lee Jong-Ho
Published: April 2013

We characterized normalized noise power density (S
I/I
BL
2) and bit-line (BL) current fluctuation (ΔI
BL) using traps generated applying cycling stress in 26 nm NAND flash memory. The ΔI
BL, S
I/I
BL
2, and capture (τc) and emission times (τe) of random telegraph noise (RTN) were measured before and after cycling stress, respectively. With cycling stress, traps were generated, and S
I/I
BL
2 and ΔI
BL were increased significantly. The τc and τe of RTN after cycling stress are similar with to those before cycling stress. RTN was characterized in terms of the trap position in the three-dimensional space (x
T, y
T, and z
T) of the tunneling oxide and trap energy (E
T). three-dimensional technology computer-aided design (TCAD) simulation was used to determine the position of z
T through the effect of adjacent BL cells.
High-Current Reliability and Growth Conditions of Multilayer Graphene Wire Obtained by Annealing Sputtered Amorphous Carbon
Authors: Sato Motonobu , Takahashi Makoto , Nakano Haruhisa , Muro Takayuki , Takakuwa Yuji , Sato Shintaro , Nihei Mizuhisa , Yokoyama Naoki
Published: April 2013

We fabricated multilayer graphene directly on SiO2 by annealing of sputtered amorphous carbon under a catalyst layer without complicated transfer processes, and investigated the effects of the catalysts and the annealing ambient gases on obtaining large-grain, multilayer graphene. As a result, it was found that annealing conditions with a Co catalyst layer in a nitrogen gas atmosphere are important for increasing the ratio of oriented graphene sheets, corresponding to a lower resistivity of the film. Furthermore, it was confirmed that the multilayer graphene wire obtained by optimizing the growth conditions can sustain a high current density of 107 A/cm2, that is, the lifetime of the multilayer graphene wire is over two orders of magnitude longer than that of a Cu wire with the same current density; this current density is over one order of magnitude higher than the current density that can be carried by a Cu wire for the same lifetime.
Tunnel Field-Effect Transistor with Epitaxially Grown Tunnel Junction Fabricated by Source/Drain-First and Tunnel-Junction-Last Processes
Authors: Morita Yukinori , Mori Takahiro , Migita Shinji , Mizubayashi Wataru , Tanabe Akihito , Fukuda Koichi , Masahara Meishoku , Ota Hiroyuki
Published: April 2013

We fabricate p- and n-channel Si tunnel field-effect transistors (TFETs) with an epitaxially grown tunnel junction. In a novel source/drain-first and tunnel-junction-last fabrication process, a thin epitaxial undoped Si channel (epichannel) is deposited on a preferentially fabricated p- or n-type source area. The epichannel sandwiched by a gate insulator and a highly doped source well acts as a parallel-plate tunnel capacitor, which effectively multiplies drain current with an enlarged tunnel area. On the basis of its simple structure and easy fabrication, symmetric n- and p-transistor and complementary metal oxide semiconductor inverter operations were successfully demonstrated.
Impacts of Surface Roughness Reduction in (110) Si Substrates Fabricated by High-Temperature Annealing on Electron Mobility in n-Channel Metal–Oxide–Semiconductor Field-Effect Transistors on (110) Si
Authors: Jeon Sung-Ho , Taoka Noriyuki , Matsumoto Hiroaki , Nakano Kiyotaka , Koyama Susumu , Kakibayasi Hiroshi , Araki Koji , Miyashita Moriya , Izunome Koji , Takenaka Mitsuru , Takagi Shinichi
Published: April 2013

The effects of high-temperature Ar/H2 annealing on (110) Si, which is known to provide flat (110) Si surfaces, have been studied from the viewpoint of metal–oxide–semiconductor (MOS) interface roughness and inversion-layer electron mobility limited by surface roughness scattering in (110) Si n-channel metal–oxide–semiconductor field-effect transistors (n-MOSFETs). It has been confirmed by quantitative transmission electron microscope (TEM) analysis that the reduction in the surface roughness on (110) Si is still maintained after gate oxidation with gate oxide thickness (T
ox) of 6.9 nm. The mobility measurement of (110) Si n-MOSFETs fabricated using Si wafers with high-temperature Ar/H2 annealing has revealed that the high-temperature annealing increases the electron mobility of (110) Si MOSFETs at 10 K by 14 and 5.7% for T
ox values of 6.9 and 8.9 nm, respectively, and increases the electron mobility at 300 K by 2.5 and 0.72% for T
ox values of 6.9 and 8.9 nm, respectively. The T
ox dependence of the enhancement factor might be attributable to the increase in MOS interface roughness with increasing T
ox. It has also been observed that the mobility enhancement factor is slightly dependent on the channel direction. The mobility increase has been observed to be greater along <111> than along <112>.
Novel Field Effect Diode Type Vertical Capacitorless One Transistor Dynamic Random Access Memory Cell with Negative Hold Bit Line Bias Scheme for Improving the Hold Characteristics
Authors: Imamoto Takuya , Endoh Tetsuo
Published: April 2013

In this paper, the novel field effect diode (FED) type vertical capacitorless one transistor dynamic random access memory (1T-DRAM) cell with negative hold bit line (BL) voltage (V
BL) scheme is proposed. In comparison with the conventional planar type, the proposed vertical type with negative hold V
BL scheme shows excellent static and disturb retention time. The proposed vertical type memory cell with negative hold V
BL scheme achieves 1,000 times longer static retention time and 104 times longer BL disturb retention time at 85 °C than that of the conventional planar type. Furthermore, the proposed vertical type memory cell has a small cell size of 4F2 due to its stacked vertical structure. The proposed FED type vertical capacitorless 1T-DRAM cell with negative hold V
BL scheme is shown to be an excellent candidate for stand-alone and embedded memory applications and extends scaling limitations.
Physical Guiding Principles for High Quality Resistive Random Access Memory Stack with Al2O3 Insertion Layer
Authors: Yang Moon Young , Kamiya Katsumasa , Magyari-Köpe Blanka , Momida Hiroyoshi , Ohno Takahisa , Niwa Masaaki , Nishi Yoshio , Shiraishi Kenji
Published: April 2013

We theoretically clarified the atomistic role of the Al2O3 oxygen vacancy (VO) barrier layer in advanced ReRAM stacks. We found that VO filament formation in Al2O3 can be controlled by applying voltage when the Al2O3 layer is in contact with VO source layer such as Hf, although VO formation in Al2O3 is difficult in usual situation. Moreover, we proposed a physical guiding principle toward designing high quality ReRAM stacks with Al2O3 VO barrier layers.
A Programmable Difference-of-Gaussian Analog Complementary Metal Oxide Semiconductor Image Sensor Operating in the Subthreshold Regime
Authors: Wang Zheye , Shibata Tadashi
Published: April 2013

A difference-of-Gaussian (DoG) analog CMOS image sensor architecture in which the kernel size and shape are made arbitrarily programmable has been developed based on the MOS subthreshold characteristics. The variability of MOS transistor threshold voltage causes a serious problem in the circuits operating in the subthreshold regime because the current varies exponentially depending on the threshold voltage. The problem has been alleviated by introducing a cancellation scheme employing a switched floating-gate MOS (neuMOS) circuitry. A proof-of-concept chip was designed in a 0.18-µm CMOS technology. The operation of the designed circuits was investigated by SPICE (simulation program with integrated circuit emphasis) simulation and their basic functions were demonstrated. A part of the core function, i.e., the generation of the Gaussian function profile, was confirmed by the measurement of a fabricated test circuit.
Fractionally Injection-Locked Frequency Multiplication Technique with Multi-Phase Ring Voltage-Controlled Oscillator
Authors: Ikeda Sho , Lee Sang-yeop , Kamimura Tatsuya , Ito Hiroyuki , Ishihara Noboru , Masu Kazuya
Published: April 2013

In this paper, we present a fractionally injection-locked frequency multiplication technique that can solve the tradeoff between the selectable frequency step and phase noise of injection-locked frequency multipliers (ILFMs). For a given output frequency step, the phase noise of the proposed ILFM is lower than that of conventional ILFMs because higher-frequency signals can be injected. The proposed ILFM was fabricated using a 180 nm Si complementary metal oxide semiconductor (CMOS) process. 1/2-, 1/3-, 1/4-, and 1/6-integral frequency multiplications were realized, which means that the output frequency resolution is 6 times as high as that of conventional ILFM. When the reference frequency was 100 MHz, the measured phase noise at 725 (= 100×29/4) MHz was -120 dBc/Hz at a 1 MHz offset, and that at 767 (= 100×23/3) MHz was -119 dBc/Hz at 1 MHz offset.
Mechanism Study of Gate Leakage Current for AlGaN/GaN High Electron Mobility Transistor Structure Under High Reverse Bias by Thin Surface Barrier Model and Technology Computer Aided Design Simulation
Authors: Hayashi Kazuo , Yamaguchi Yutaro , Oishi Toshiyuki , Otsuka Hiroshi , Yamanaka Koji , Nakayama Masatoshi , Miyamoto Yasuyuki
Published: April 2013

Gate leakage current mechanism in GaN high electron mobility transistors (HEMTs) has been studied using a two-dimensional thin surface barrier (TSB) model to represent two unintentional donor thin layers that exit under and outside the gate electrode due to the existence of surface defects. The donor thin layer outside the gate affects the reverse gate current at the high gate voltage above the pinch-off voltage. Higher donor concentration of thin layer outside the gate results in larger ratio of lateral to vertical components of the electric field at the gate edge. On the other hand, the electric field at the center of the gate has only the vertical electric field component. As a result, the two-dimensional effects are only important for the reverse gate current above the pinch-off voltage. We have confirmed in this paper that the simulation results provided by our model correlate very well with the experimental reverse gate current characteristics of the device for a very wide range of reverse gate voltage from 0.1 to 90 V.
Strongly Enhanced Four-Wave Mixing Signal from GaAs/AlAs Cavity with InAs Quantnm Dots Embedded in Strain-Relaxed Barriers
Authors: Yasunaga Yukinori , Ueyama Hyuga , Morita Ken , Kitada Takahiro , Isu Toshiro
Published: April 2013

Strong ultrafast four-wave mixing signals at ∼1.5 µm were demonstrated in a GaAs/AlAs multilayer cavity containing self-assembled InAs quantum dots (QDs) embedded in strain-relaxed In0.35Ga0.65As barriers. Time-resolved optical measurements using 100 fs pulses with 100 kHz repetition rate were carried out in the various excitation powers at room temperature. Strongly enhanced four-wave-mixing signals were observed for a cavity with two InAs QDs layers inserted in a half-wavelength (λ/2) cavity layer compared with that of a GaAs λ/2 cavity that had no QDs, in the whole range of excitation power (0.3–2 mW). For a low excitation power below 0.6 mW, the four-wave-mixing signals were about two orders of magnitude larger than that of the GaAs λ/2 cavity owing to the large nonlinearity of the InAs QDs.
Impact of Illumination on Charge Injection and Accumulation in Organic Transistor in Presence of Plasmonic Nanoparticles
Authors: Lee Keanchuan , Weis Martin , Chen Xiangyu , Taguchi Dai , Manaka Takaaki , Iwamoto Mitsumasa
Published: April 2013

Effects of illumination on the carrier injection and transport due to photogenerated carriers were investigated in pentacene organic field-effect transistor (OFET). A plasmonic nanoparticles self-assembled monolayer (SAM) was incorporated in pentacene FET to act to enhance the photo-carrier generation. The influence of nanoparticles (NPs) on the photogeneration as well as on the charge trapping has been investigated using the current–voltage (I–V) and impedance spectroscopy (IS) measurements. The I–V results proved higher amount of photogenerated charge in presence of NPs even though this device has the contact resistance about two orders higher and effective mobility an order lower than the reference device without plasmonic NPs. The IS analysis of relaxation times verified strong influence of NPs on the charge trapping.
Synthesis and Physical Vapor Deposition of Low-Molecular-Weight Poly(3,4-ethylenedioxythiophene)
Authors: Eguchi Taikai , Tsuchiya Yuusuke , Hasegawa Ai , Tanaka Kuniaki , Ogino Kenji , Usui Hiroaki
Published: April 2013

Thin films of poly(3,4-ethylenedioxythiophene) (PEDOT) were obtained by physical vapor deposition. To this end, low-molecular-weight PEDOT was synthesized by oxidative polymerization using oxygen as the oxidizing reagent with palladium acetate and copper acetate as the catalysts. The degree of polymerization was controlled by adjusting reaction time. The material can be vapor-deposited by thermal evaporation when the degree of polymerization was about 10. Formation of PEDOT thin films was confirmed by infrared spectroscopy. The optical absorption edge of the deposited film showed a redshift with increasing degree of polymerization. The electrical conductivity of the deposited film was in the range from 10-4 to 10-3 S/cm. The deposited films are expected to be in the nondoped state since the oxidizing reagent (oxygen) is unlikely to remain in the films.
Fabrication and In vivo Evaluation of Poly(3,4-ethylenedioxythiophene) Stimulus Electrodes for Fully Implantable Retinal Prosthesis
Authors: Kigure Chikashi , Naganuma Hideki , Sasaki Yuichiro , Kino Hisashi , Tomita Hiroshi , Tanaka Tetsu
Published: April 2013

The development of poly(3,4-ethylenedioxythiophene) (PEDOT) stimulus electrodes and the relationship between the electrical stimulation of a rabbit retina and electrically evoked potential (EEP) were studied in detail. We fabricated implantable flexible cables with Pt, IrOx, and PEDOT electrodes and evaluated the electrochemical impedances (EIs) and charge injection capacities (CICs) of such electrodes. From the result, we confirmed that PEDOT electrodes have both lower EIs and larger CICs than Pt and IrOxelectrodes. In addition, we performed in vivo experiments with PEDOT electrodes and clarified the relationships between the electrical stimulation of the rabbit retina and EEP. It is highly probable that visual restoration will be realized safely with PEDOT electrodes.
Study of Insertion Characteristics of Si Neural Probe with Sharpened Tip for Minimally Invasive Insertion to Brain
Authors: Lee Sanghoon , Kanno Soichiro , Kino Hisashi , Tanaka Tetsu
Published: April 2013

We have fabricated various types of Si neural probe for in vivo and in vitro neuronal signal recordings by combining standard photolithography with a bulk micromachining process. To place the probe tip at target areas in the brain precisely, the mechanical properties of the Si neural probes with various tip shapes were carefully investigated under different insertion conditions to brain phantoms. As results, the minimum length and penetration force of the Si neural probe were determined from conditions where the Si neural probe began to penetrate the surface of the brain phantom. To control buckling of the Si neural probe, it is necessary to optimize the insertion rate in accordance with the conditions of the Si neural probe. Although the insertion forces of the Si neural probe with a sharpened tip were smaller than those of the Si neural probe with a normal tip, the effect of the probe tip shape became small with increased insertion speeds.
Parasitic Bipolar Effect of a Thin-Film Silicon-on-Insulator Power Metal–Oxide–Semiconductor Field-Effect Transistor at High Temperatures
Authors: Uchida Atsushi , Morisawa Yuka , Matsumoto Satoshi
Published: April 2013

In this paper, we describe the parasitic bipolar effect of the fabricated thin-film silicon-on-insulator (SOI) power metal–oxide–semiconductor field-effect transistor (MOSFET) at high temperatures. This effect in the on-state was suppressed as temperature increased. This effect in the off-state was promoted as temperature and body contact pitch increased. The parasitic bipolar effect caused by the thermally generated current is enhanced by increasing temperature and decreasing channel length. This reduced breakdown voltage.
Plan-View and Cross-Sectional Photoluminescence Imaging Analyses of Threading Dislocations in 4H-SiC Epilayers
Authors: Nagano Masahiro , Kamata Isaho , Tsuchida Hidekazu
Published: April 2013

We performed a plan-view and cross-sectional photoluminescence (PL) imaging and a spectral analysis of threading dislocations in 4H-SiC epilayers in the near-infrared region. The bright PL spots of threading screw dislocations (TSDs) and threading edge dislocations (TEDs) observed in the plan-view PL imaging are compared with the grazing incidence synchrotron X-ray topography contrast, and precise discrimination of threading dislocations using the PL technique and the direct acquisition of Burgers vector directions of TEDs are demonstrated. The inclination angles of TSDs and TEDs across a thick epilayer are revealed by the cross-sectional PL imaging, and the variations in the plan-view PL appearances of the threading dislocations are confirmed to originate from the line directions of such dislocations.
Impact of the Use of Xe on Electrical Properties in Magnetron-Sputtering Deposited Amorphous InGaZnO Thin-Film Transistors
Authors: Goto Tetsuya , Sugawa Shigetoshi , Ohmi Tadahiro
Published: April 2013

The use of heavier noble gases such as Xe instead of the lighter Ar during the magnetron sputtering deposition of amorphous indium–gallium–zinc oxide films is introduced to the fabrication of their thin-film transistors. Higher mobility in the Xe case is observed; typically, the saturation-region field-effect mobility is increased from ∼10 cm2V-1s-1in the Ar case to ∼13 cm2V-1s-1in the Xe case. The Hall mobility is also higher in the Xe case in the carrier density range of approximately 1017–1018cm-3. These results suggest that the Xe sputtering can reduce film damage, and improve film quality.
Effect of Indium–Tin-Oxide Schottky Contact on the Resistance Switching of NiO Film
Authors: No Young Soo , Park Dong-Hee , Lee Jeon-Kook , Lee Youn-Seoung , Kim Tae Whan , Choi Won-Kook
Published: April 2013

The effect of electrode materials on resistance switching was evaluated on the Pt/NiO/electrode (EL) structures where the EL contacts were Pt, Al, and indium–tin-oxide (ITO). It was confirmed that ohmic Pt contact needs to induce the effective electric field for resistance switching across the NiO film. For the Pt/NiO/Al structure, the barrier height of the Al Schottky contact was measured as 0.66 eV and no resistance switching was observed owing to a large voltage drop at the rectifying interface induced by the reduction of NiO resulting from the formation of Al oxide. In the ITO (EL)/NiO/Pt structure, the barrier height of the Schottky contact between ITO and NiO was about 0.52 eV and it did not show any resistance switching, either. Through the depth-profile study by X-ray photoelectron spectroscopy, chemical reactions at the interface ITO/NiO was identified to be not too much evolved compared with that of NiO/Al, which might due to be abundant oxygen on the ITO surface. Such Schottky barrier heights 0.52–0.66 eV were considered too high to induce a sufficient electric field in the NiO film causing the resistance switching.
Deposition of Ag(In,Ga)Se2 Solar Cells by a Modified Three-Stage Method Using a Low-Temperature-Deposited Ag–Se Cap Layer
Authors: Xianfeng Zhang , Kobayashi Tsuyoshi , Kurokawa Yasuyoshi , Miyajima Shinsuke , Yamada Akira
Published: April 2013

Ag(In,Ga)Se2 (AIGS) films with a uniform Ag depth profile were successfully deposited by a modified three-stage method in which a Ag–Se layer was pre deposited at a low temperature (350 °C) before a high-temperature process at around 600 °C. The Ag–Se layer acted as a cap layer and effectively prevented the desorption of In from the films during the high-temperature process. The In/(In+Ga) ratio of the AIGS films was found to be about 0.15. The best AIGS solar cell deposited by this method showed an active area conversion efficiency of 10.7%.
1 ms Pulse Beam Generation and Acceleration by Photocathode Radio Frequency Gun and Superconducting Accelerator
Authors: Kuriki Masao , Iijima Hokuto , Hosoda Seiichi , Watanabe Ken , Hayano Hitoshi , Urakawa Junji , Isoyama Goro , Kato Ryukou , Kawase Keigo , Kuramoto Ayaka , Kashiwagi Shigeru , Sakaue Kazuyuki
Published: April 2013

We report the successful generation and acceleration of a 1-ms-long pulse and multibunch electron beam by a normal conducting photocathode RF gun and a super conducting accelerator at the KEK Superconducting Test Facility (STF). A 1.3 GHz normal conducting RF gun generates a 1 ms and 10 mA macropulse that fully satisfies the designed parameters. This is the longest macropulse generated by a normal conducting RF gun with a frequency of more than 1 GHz. A beam acceleration of up to 40 MeV was demonstrated with more than 60% of the designed average current. The accelerated beam properties were evaluated: the intensity and energy fluctuations were 3.8% and less than 0.08%, respectively. These beam properties are sufficient for the requirement of the STF operation including that in the quantum beam project, which is high-brightness-X-ray generation by inverse laser Compton scattering. The intensity fluctuation should be improved toward the International Linear Collider (ILC) for uniform acceleration.
Do student-student interactions improve their language learning? A comparison between GTM and CLT approaches
Authors: Raissi Reza
Published: April 2013

Nowadays most of the scholars in the field of foreign/ second language teaching emphasized on learner centered approaches of language teaching and replacing them by old ones. In this research, researcher examined two different teaching approaches which are very common in Iran where English considered as a foreign language, namely Communicative Language Teaching (CLT) and Grammar Translation Method (GTM). Two groups of thirty participants have been participated in this study namely control and treatment groups. Students of the treatment group have received the CLT instruction in which they had high amount of interaction in the considered classes during 14 weeks of the classes while students in the control group didn’t receive any interaction in the target language by implementing GTM approach. Pretest and delayed posttest have been used in this study for measuring student’s proficiency during the course instruction. Results of the experiment have been analyzed descriptively which shows that by implementing CLT among nonnative students, their general knowledge of English can be improved significantly. At the end of the research some useful pedagogical implications have been proposed by the researcher.   Keywords - Language teaching and learning, interaction hypothesis, Communicative Language Teaching, Grammar Translation Method, English as a Foreign Language.
Library Marketing: A Promotional Strategy
Authors: Laspiñas Marilyn L.
Published: April 2013

The study determined library promotional strategies used by the MLIS students for 2nd semester 2008-2009. This study finds out the professional practices of the MLIS students; the different library promotional strategies; and the impacts of the promotional strategies to the clientele. The study employed qualitative approach. This method was designed to gather information about the existing promotional strategies with the primary purpose of describing the efficiency in providing quality services to the clientele. There are twenty MLIS students explore with three different types of libraries (school, academic, and special). Results showed that school libraries have monthly bulletin board display. On the other hand, school and academic libraries conduct regular library orientation and instructions, disseminates library guides, brochures, and new acquisitions to the students, faculty, department chairs, college deans, etc. However, the study found out the different library promotional strategies used by the MLIS students. Moreover, the study revealed the awareness of the clientele of the available library services, facilities and equipment, and resources and informed the rules and regulations of the library; 95% of the students and faculty utilized the library; the clientele is independent in using the library facilities and equipment, and in locating the books in the shelves. Keywords - Education, library marketing, promotional strategy, MLIS students, Philippines
Congress Must Update FDA Regulations for Medical AI
Authors: Gottlieb Scott
Published: July 2024

This JAMA Forum discusses pending legislation in the US House and Senate and the history of the “firm-based approach” the US Food and Drug Administration (FDA) could use when regulating artificial intelligence (AI) medical devices to augment patient care.
Hepatitis B Vaccine Refusal Trends in Washington, DC, Newborns, 2017-2022
Authors: Yang Y. Tony , Leslie Timothy F. , Delamater Paul L.
Published: July 2024

This cross-sectional study evaluates trends in rates of hepatitis B vaccine birth dose refusals in Washington, DC, from 2017 to 2022.
Women, Economy and
Authors: Visanich Valerie , Esterchild Elizabeth
Published: July 2024

Women's position in the economy and their general well‐being in all other spheres of life depend heavily on the type of society in which they reside. Historically, in various cultures, women have been excluded from economic opportunities by various restrictions being placed on their full participation in the workforce. In addition, women contribute, disproportionately to men, to unpaid carework. In recent years, the bridging of the gender gap has come to the forefront of international and national forums and policies, and the important role that women play in the economy has been given greater weight. This entry examines the place of women in the economy and changes to it over the years.
Dynamic Amorphous Zn0.17MnO2−n·0.52H2O Electrochemical Crystal Transition for Highly Reversible Zinc‐Ion Batteries with Ultrahigh Capacity and Long Lifespan
Authors: Chen Yumin , Miao Ling , Song Ziyang , Duan Hui , Lv Yaokang , Gan Lihua , Liu Mingxian
Published: July 2024

Mn‐based oxides promise high energy density and low toxicity cathodes for aqueous zinc‐ion batteries (ZIBs) but suffer from complex irreversible phase transitions, accompanied by continuous disproportionation reactions and manganese dissolution. Tailor‐made reversible and robust crystal structure in Mn‐based material is crucial and challenging. Here a controllable electrochemical oxidation induced crystal transition strategy is developed for the transformation of cubic α‐Mn2O3 into amorphous Zn0.17MnO2−n·0.52H2O, which serves as the host of Zn2+, empowering more highly accessible built‐in zincophilic sites whilst alleviating the lattice repulsion of Zn2+ (de)intercalation. As confirmed by crystal structure evolution characterizations and theoretical simulations, the amorphous Zn0.17MnO2−n·0.52H2O with excellent electronic properties and low zinc‐ion migration barrier can be reversibly converted into ZnMn3O7·3H2O. This stabilized dynamic electrochemical crystal transition equilibrium contributes ultrahigh capacity (558 mAh g−1), high‐energy density (696 Wh kg−1@6 kW kg−1), and superior stability (5000 cycles). The approach can also extend to Mn3O4 and α‐MnO2, opening new insights into electrochemical oxidation induced crystal conversion to build highly reversible and durable ZIBs.
Tough Supramolecular Hydrogels Crafted via Lignin‐Induced Self‐Assembly
Authors: Pan Xiaofeng , Pan Jiawei , Li Xiang , Wang Zhongkai , Ni Yonghao , Wang Qinhua
Published: July 2024

Supramolecular hydrogels are typically assembled through weak non‐covalent interactions, posing a significant challenge in achieving ultra strength. Developing a higher strength based on molecular/nanoscale engineering concepts is a potential improvement strategy. Herein, a super‐tough supramolecular hydrogel is assembled by gradually diffusing lignosulfonate sodium (LS) into a polyvinyl alcohol (PVA) solution. Both simulations and analytical results indicate that the assembly and subsequent enhancement of the crosslinked network are primarily attributed to LS‐induced formation and gradual densification of strong crystalline domains within the hydrogel. The optimized hydrogel exhibits impressive mechanical properties with tensile strength of ≈20 MPa, Young's modulus of ≈14 MPa, and toughness of ≈50 MJ m⁻3, making it the strongest lignin‐PVA/polymer hydrogel known so far. Moreover, LS provides the supramolecular hydrogel with excellent low‐temperature stability (<‐60 °C), antibacterial, and UV‐blocking capability (≈100%). Interestingly, the diffusion ability of LS is demonstrated for self‐restructuring damaged supramolecular hydrogel, achieving 3D patterning on hydrogel surfaces, and enhancing the local strength of the freeze‐thaw PVA hydrogel. The goal is to foster a versatile hydrogel platform by combining eco‐friendly LS with biocompatible PVA, paving the way for innovation and interdisciplinarity in biomedicine, engineering materials, and forestry science.