bluuebunny/crossref_metadata_2025 huggingface dataset:
Predicting sleep disordered breathing in outpatients with suspected OSA
Authors: Cowan Douglas C , Allardice Gwen , MacFarlane Duncan , Ramsay Darren , Ambler Heather , Banham Stephen , Livingston Eric , Carlin Christopher
Published: April 2014

Objective

To validate the utilities of Berlin, STOP and STOP-BANG Questionnaires, other patient characteristics, comorbidities, Epworth Sleepiness Scale (ESS), fractional exhaled nitric oxide (FENO) and blood markers for the prediction of sleep disordered breathing (SDB) on limited polygraphy.

Setting

North Glasgow Sleep Service (a tertiary referral centre).

Participants

129 consecutive patients, aged ≥16 years, referred to the sleep clinic for assessment of possible obstructive sleep apnoea.

Interventions

We selected cut-points of apnoea hypopnoea index (AHI) of ≥5 and ≥15/h from their home polygraphy and determined associations of these with individual symptoms, questionnaire scores and other results. Receiver operating characteristic analysis and univariate and multivariate logistic regression were used to explore these.

Primary and secondary outcomes measures

Primary: The utility of STOP, STOP-BANG and Berlin Questionnaires for prediction of SDB.Secondary: The utility of other measures for prediction of SDB.

Results

AHI was ≥5 in 97 patients and ≥15 in 56 patients. STOP and STOP-BANG scores were associated with both AHI cut-points but results with ESS and Berlin Questionnaire scores were negative. STOP-BANG had a negative predictive value 1.00 (0.77–1.00) for an AHI ≥15 with a score ≥3 predicting AHI ≥5 with sensitivity 0.93 (95% CI 0.84 to 0.98) and accuracy 79%, while a score ≥6 predicted AHI ≥15 with specificity 0.78 (0.65 to 0.88) and accuracy 72%. Neck circumference ≥17 inch and presence of witnessed apnoeas were independent predictors of SDB.

Conclusions

STOP and STOP-BANG Questionnaires have utility for the prediction of SDB in the sleep clinic population. Modification of the STOP-BANG Questionnaire merits further study in this and other patient groups.
The quality of police data on RTC fatalities in India
Authors: Raban Magdalena Z , Dandona Lalit , Dandona Rakhi
Published: April 2014

Background

Police records are the major source of data on road traffic collision (RTC) deaths in India.

Objective

To examine the utility and quality of police data on RTC deaths available from two sources.

Methods

Police data on RTC deaths available from National Crime Records Bureau (NCRB) and Ministry of Road Transport and Highways (MoRTH) were accessed. The utility of these data for surveillance and consistency of data reported by the two organisations was examined. Data completeness was assessed for India, its six geographic regions and for the mode of travel using cause of death estimates from the Sample Registration System (SRS) and Global Burden of Disease (GBD) as a reference.

Results

Data imperative for surveillance including deaths by age and sex for each state, the counterpart vehicle or object and use of safety equipment were not available. The total number of deaths reported by NCRB and MoRTH was similar across states but showed large differences by mode of travel categories. Compared with GBD, completeness of the number of fatalities reported by both sources in 2010 was approximately 50%. Completeness for the geographic regions ranged from 26.4% to 76.4%, using SRS data, in 2001–2003.

Conclusions

This detailed examination of police data on RTC fatalities from two sources has raised several questions about the validity of these data and has highlighted a number of gaps that limit the usefulness of these data for surveillance and informing road safety policies. Unless these are addressed, significant reductions in RTC fatalities cannot be achieved in India.
Genetically predicted 17β-estradiol and systemic inflammation in women: a separate-sample Mendelian randomisation analysis in the Guangzhou Biobank Cohort Study
Authors: Zhao J , Jiang C Q , Lam T H , Liu B , Cheng K K , Kavikondala S , Zhang W S , Leung G M , Schooling C M
Published: April 2014

Background

Many chronic diseases are characterised by low-grade systemic inflammation. Oestrogens may promote immune response consistent with sex-specific patterns of diseases. In vitro culture and animal experiments suggest oestrogens are anti-inflammatory and might thereby protect against low-grade systemic inflammation. Evidence from epidemiological studies is limited. Using a Mendelian randomisation analysis with a separate-sample instrumental variable (SSIV) estimator, we examined the association of genetically predicted 17β-estradiol with well-established systemic inflammatory markers (total white cell count, granulocyte and lymphocyte count).

Methods

A genetic score predicting 17β-estradiol was developed in 237 young Chinese women (university students) from Hong Kong based on a parsimonious set of genetic polymorphisms (ESR1(rs2175898) andCYP19A1(rs1008805)). Multivariable linear regression was used to examine the association of genetically predicted 17β-estradiol with systemic inflammatory markers among 3096 older (50+ years) Chinese women from the Guangzhou Biobank Cohort Study.

Results

Predicted 17β-estradiol was negatively associated with white blood cell count (−6.3 103/mL, 95% CI −11.4 to −1.3) and granulocyte count (−4.5 103/mL, 95% CI −8.5 to −0.4) but not lymphocyte count (−1.5 103/mL, 95% CI −3.4 to 0.4) adjusted for age only. Results were similar further adjusted for education, smoking, use of alcohol, physical activity, Body Mass Index, waist-hip ratio, age of menarche, age at menopause, use of hormonal contraceptives and hormone replacement therapy.

Conclusions

Endogenous genetically predicted 17β-estradiol reduced low-grade systemic inflammatory markers (white blood cell count and granulocyte count), consistent with experimental and ecological evidence of 17β-estradiol promoting immune response. Replication in a larger sample is required.
Extended supramolecular [3×3] Mn9 grid arrays organized by Ag(I) and Au(III)  — structural and magnetic properties
Authors: Milway Victoria A. , Dawe Louise N. , Thompson Laurence K.
Published: April 2014

A square [3×3] Mn(II)9 supramolecular grid complex with appended ligand SEt groups provides a focus for extended molecular organization through outer-sphere interactions with soft metal ions. Reactions with Ag(I) and Au(III) led to extended 3D arrays in complexes [Mn9(SEt2poap)6]Ag5.75(CF3SO3)2(NO3)9.75(H2O)18 (4), [Mn9(SEt2poap)6][Ag(CN)2]2 [Ag3(CN)5](OH)2(H2O)18 (5), and [Mn9(SEt2poap-3H)4(SEt2poap-2H)2(AuCl3)4] (AuCl4)3.25Cl1.75(H2O)14 (6), involving Mn9 [3×3] square grids with external Ag–S contacts, but with Au(III) extended organization resulting through Au–N ligand contacts only. Structural and magnetic properties are discussed. In the gold complex, magnetic and structural data revealed that Au(III) behaves as an oxidant, leading to oxidation of some corner Mn(II) sites in the grid to Mn(III). Intra-grid magnetic exchange is antiferromagnetic in all cases (J = −4.4 cm−1 (4), J = −5.0 cm−1 (5)), leading to noncompensation of spins because of the odd number of metal ions and low-spin ground states.
Synthesis, characterization, redox, and Hg2+optical ion sensing properties of ferrocenyl-containing maleo- and fumaronitrile derivatives
Authors: Dahlby Michael R. , Purchel Anatolii A. , Solntsev Pavlo V. , Rohde Gregory T. , Zatsikha Yuriy V. , Nemykin Victor N.
Published: April 2014

Mono-((Z)-2-amino-3-((E)-ferrocenylideneamino)butenedinitrile) (1) and bis-((E)-2,3-bis-((E)-ferrocenylideneamino)butenedinitrile) (2) substituted Schiff bases obtained by the reaction between ferrocenecarbaldehyde and diaminomaleonitrile were prepared and characterized by1H and13C NMR, IR, and UV-vis-NIR spectroscopy methods, elemental analysis, and X-ray crystallography. Density functional theory and time-dependent density functional theory were used to elucidate the electronic structure and the origin of observed excited states in both compounds. Electrochemical techniques were employed to investigate the possibility for the formation of a mixed-valence state of the iron centers in 2+, which are connected by a conjugated π-system. Two reversible oxidation potentials were observed in cyclic voltammetry, and spectroelectrochemical experiments revealed the presence of a low-energy intervalence charge transfer band in 2+, corresponding to class II of the mixed-valence systems. Both complexes were tested for cation-recognition properties using a variety of main group and transition-metal cations. It was shown that complex 1 can be used as a selective optical sensor in recognition of Hg2+ions. It was also shown by NMR spectroscopy and X-ray crystallography that one of the final reaction products between Hg2+ions and complex 1 is 2-ferrocenyl-4,5-dicyanoimidazole (3).
Do natural history data predict the movement ecology of fishes in Lake Ontario streams?
Authors: Dolinsek Ivan J. , McLaughlin Robert L. , Grant James W.A. , O’Connor Lisa M. , Pratt Thomas C.
Published: April 2014

Little is known about the movements of most stream fishes, so fisheries managers often rely on natural history data from the literature to make management decisions. Observations of over 15 000 individuals from 37 species across 3 years were used to evaluate four aspects of the reliability of literature data for predicting the movement behaviour of stream fishes: (i) water temperature when fish enter streams; (ii) reasons for moving into the streams; (iii) stream residence times of migrants; and (iv) relative use of lake and stream habitats. Comparisons of our data for arrival times in the streams, water temperature at arrival, and time spent in the streams were highly correlated with literature data, whereas relative use of the lake was not. Further, our detailed data revealed two novel findings: (1) in many species juveniles were also moving into streams, even in those species where adults were clearly spawning in the streams; and (2) adult-sized individuals were moving into streams for nonreproductive purposes. Our results suggest that fishery managers can confidently use natural history information to gain general insights into the movement ecology of fishes, but should also recognize that this information remains incomplete in important ways.
Factors associated with the success of native and nonnative species in an unfragmented arid-land riverscape
Authors: Whitney James E. , Gido Keith B. , Propst David L.
Published: April 2014

Native fish persistence is threatened by the establishment and spread of nonnatives. Identifying environmental and biotic factors associated with the success of co-occurring native fishes and nonnative taxa is central to identifying mechanisms responsible for native declines and nonnative expansion. We related physicochemical variables, food resources, and community composition to the success (secondary production) of native and nonnative fishes, tadpoles, and crayfish across six sites in three reaches (tributary, canyon, and valley) during 2008–2011 in the Gila River, New Mexico. Native fish success was greater than nonnative success across a range of physicochemical conditions, basal resource supply rates, and nonnative communities, although nonnative fish, tadpole, and crayfish success could approach or exceed that of native fishes in canyon habitats, a warm-water tributary, or in downstream valley sites, respectively. Native fish success was lowest in canyon reaches, when flathead catfish (Pylodictis olivaris) and common carp (Cyprinus carpio) were highly productive. These results demonstrate the potential for native fish persistence in the presence of nonnatives in physically unmodified streams, highlighting the importance of habitat preservation for native conservation.
Klein–Gordon oscillator under a uniform magnetic field in cosmic string space–time
Authors: Boumali Abdelmalek , Messai Nadjette
Published: April 2014

In this article, we study the influence of the gravitational fields produced by a topology such as cosmic string space–time on a Klein–Gordon oscillator in the presence of a uniform magnetic field. We present the eigensolutions of our problem in question and analyze the influence of cosmic string space–time on the eigenvalues.
Controlling photons in a box and exploring the quantum to classical boundary
Authors: Haroche Serge
Published: April 2014

Microwave photons trapped in a superconducting cavity constitute an ideal system to realize some of the thought experiments imagined by the founding fathers of quantum physics. The interaction of these trapped photons with Rydberg atoms crossing the cavity illustrates fundamental aspects of measurement theory. The experiments performed with this "photon box" at the Ecole Normale Supérieure (ENS) belong to the domain of quantum optics called "Cavity Quantum Electrodynamics." We have realized the non-destructive counting of photons, the recording of field quantum jumps, the preparation and reconstruction of "Schrödinger cat" states of radiation and the study of their decoherence, which provides a striking illustration of the transition from the quantum to the classical world. These experiments have also led to the demonstration of basic steps in quantum information processing, including the deterministic entanglement of atoms and the realization of quantum gates using atoms and photons as quantum bits. This lecture starts with an introduction stressing the connection between the ENS photon box and the ion trap experiments of David Wineland, whose accompanying lecture recalls his own contribution to the field of single particle control. I give then a personal account of the early days of Cavity Quantum Electrodynamics before describing the main experiments performed at ENS during the last twenty years and concluding with a discussion comparing our work to other research dealing with the control of single quantum particles.
SPARSITY SCORE: A NOVEL GRAPH-PRESERVING FEATURE SELECTION METHOD
Authors: LIU MINGXIA , ZHANG DAOQIANG
Published: April 2014

As thousands of features are available in many pattern recognition and machine learning applications, feature selection remains an important task to find the most compact representation of the original data. In the literature, although a number of feature selection methods have been developed, most of them focus on optimizing specific objective functions. In this paper, we first propose a general graph-preserving feature selection framework where graphs to be preserved vary in specific definitions, and show that a number of existing filter-type feature selection algorithms can be unified within this framework. Then, based on the proposed framework, a new filter-type feature selection method called sparsity score (SS) is proposed. This method aims to preserve the structure of a pre-defined l1graph that is proven robust to data noise. Here, the modified sparse representation based on an l1-norm minimization problem is used to determine the graph adjacency structure and corresponding affinity weight matrix simultaneously. Furthermore, a variant of SS called supervised SS (SuSS) is also proposed, where the l1graph to be preserved is constructed by using only data points from the same class. Experimental results of clustering and classification tasks on a series of benchmark data sets show that the proposed methods can achieve better performance than conventional filter-type feature selection methods.
SALIENCY-BASED UNSUPERVISED IMAGE MATTING
Authors: TAN GUANGHUA , QI JUN , GAO CHUNMING , CHEN JIN , ZHUO LIYUAN
Published: April 2014

Spectral matting is the state-of-the-art matting method and can well solve the highly under-conditioned matte problem without manual intervention. However, it suffers from huge computation cost and inaccurate alpha matte. This paper presents a modified spectral matting method which combines saliency detection algorithm to get a higher accuracy of alpha matte with less computational cost. First, the saliency detection algorithm is used to detect general locations of foreground objects. For saliency detection method, original two-stage scheme is replaced by feedback scheme to get a more suitable saliency map for unsupervised image matting. Next, matting components are obtained through a linear transformation of the smallest eigenvectors of the matting Laplacian matrix. Then, the improved saliency map is used for grouping matting components. Finally, the alpha matte is obtained based on matte cost function. Experiments show that the proposed method outperforms the state-of-the-art methods based on spectral matting both in speed and alpha matte accuracy.
Q-switched erbium-doped fiber laser using multi-layer graphene based saturable absorber
Authors: Kasim N. , Anyi C. L. , Haris H. , Ahmad F. , Ali N. M. , Ahmad H. , Munajat Y. , Harun S. W.
Published: April 2014

The performance of a stable passive Q-switched Erbium Ytterbium co-doped fiber laser (EYFL) operating at 1532.5 nm is demonstrated using a multi-layer graphene film based saturable absorber. The graphene is synthesized by electrochemical exfoliation of graphite at room temperature in 1% sodium dodecyl sulphate (SDS) aqueous solution. Graphene flakes obtained from the process are mixed with polyethylene oxide (PEO) as the host polymer to produce free standing composite thin film which acts as a passive Q-switcher in the EYFL ring cavity. At 980 nm pump power of 44 mW, the EYFL generates optical pulse train with a repetition rate of 12.33 kHz and pulse width of 9.36 μs. The highest energy of 5.8 nJ and the lowest pulse width of 2.68 μs are achieved at the maximum pump power of 78 mW. Further increase in the pump power is expected to further improve both the pulse energy and pulse width.
Physical and optical study of potassium-doped meta-Nitroaniline crystal (mNAK)
Authors: Thilak T. , Ahamed M. Basheer , Murugakoothan P.
Published: April 2014

A nonlinear optical crystal of potassium-doped meta-Nitroaniline (mNAK) was grown by slow evaporation method using methanol as solvent. The growth mechanism was understood by chemical etching studies. The presence of potassium in the crystal was identified by energy-dispersive X-ray diffraction. Lattice parameters for the title crystal were determined by single-crystal X-ray diffraction and powder X-ray diffraction techniques, and the functional groups in the crystal were revealed by Fourier transform infrared study. Optical properties of the crystal were evaluated by UV-Vis-NIR transmission and absorption spectra in the range of 200–1000 nm. Thermal stability of the crystal was studied by thermo gravimetric analysis and differential thermal analysis. Mechanical properties of the crystal were analyzed using Vicker's microhardness technique. Second harmonic generation efficiency of the crystal was examined using pulsed Nd :YAG laser. Finally, the third-order nonlinear optical properties of the crystal were measured using single-beam Z-scan technique.
Effects of Hot-Carrier Stress on the RF Performance of a 0.18-μm MOS Divide-by-4 LC Injection-Locked Frequency Divider
Authors: Jang Sheng-Lyang , Fu Tsung-Chao
Published: April 2014

The effect of ac hot-carrier stress on the performance of a wide locking range divide-by-4 injection-locked frequency divider (ILFD) is investigated. The ILFD was implemented in the TSMC 0.18 μm 1P6M CMOS process. The ILFD uses direct injection MOSFETs for coupling external signal to the resonators. Radio frequency (RF) circuit parameters such as oscillation frequency, tuning range, phase noise, and locking range before and after RF stress at an elevated supply voltage for 5 h have been examined by experiment. The measured locking range, operation range and phase noise after RF stress shows significant degradation from the fresh circuit condition.
Interacting two-component fluid models with varying EoS parameter
Authors: Khurshudyan M. , Pourhassan B. , Kahya E. O.
Published: April 2014

In this paper, we consider Universe filled with two-component fluid. We study two different models. In the first model we assume barotropic fluid with the linear equation of state (EoS) as the first component of total fluid. In the second model we assume van der Waals gas as the first component of total fluid. In both models, the second component assumed generalized ghost dark energy. We consider also interaction between components and discuss, numerically, cosmological quantities for two different parametrizations of EoS which varies with time. We consider this as a toy model of our Universe. We fix parameters of the model by using generalized second law of thermodynamics. Comparing our results with some observational data suggests interacting barotropic fluid with EoS parameter [Formula: see text] and generalized ghost dark energy as an appropriate model to describe our Universe.
INTANGIBLE RESOURCES AS DRIVERS OF HIGH GROWTH
Authors: RASMUSSEN CASPER CLAUDI
Published: April 2014

This paper examines the effects of innovativeness, creative climate and learning on high growth. We study how fast-growing SMEs, known as gazelles, differ from other SMEs. A survey of 345 Norwegian gazelles and 135 non-gazelles supports the idea that innovativeness is an important factor in whether a company becomes a gazelle. Creative climate, learning and innovativeness were conceptualized and analyzed as first-order constructs using confirmatory factor analysis, OLS and Probit regression. Learning and creative climate were found to have a positive impact on growth through innovativeness. Based on the data, it seems that younger companies are more likely to be innovative and grow quickly.
The 3-adic eigencurve at the boundary of weight space
Authors: Roe David
Published: April 2014

This paper generalizes work of Buzzard and Kilford to the case p = 3, giving an explicit bound for the overconvergence of the quotient Eκ/V(Eκ) and using this bound to prove that the eigencurve is a union of countably many annuli over the boundary of weight space.
Integral orbits over function fields
Authors: Huang Hsiu-Lien , Sun Chia-Liang , Wang Julie Tzu-Yueh
Published: April 2014

Over the function field of a smooth projective curve over an algebraically closed field, we investigate the set of S-integral elements in a forward orbit under a rational function by establishing some analogues of the classical Siegel theorem.
Quadratic p-ring spaces for counting dihedral fields
Authors: Mayer Daniel C.
Published: April 2014

Let p denote an odd prime. For all p-admissible conductors c over a quadratic number field [Formula: see text], p-ring spaces Vp(c) modulo c are introduced by defining a morphism ψ : f ↦ Vp(f) from the divisor lattice ℕ of positive integers to the lattice 𝒮 of subspaces of the direct product Vpof the p-elementary class group 𝒞/𝒞pand unit group U/Upof K. Their properties admit an exact count of all extension fields N over K, having the dihedral group of order 2p as absolute Galois group Gal (N | ℚ) and sharing a common discriminant dNand conductor c over K. The number mp(d, c) of these extensions is given by a formula in terms of positions of p-ring spaces in 𝒮, whose complexity increases with the dimension of the vector space Vpover the finite field 𝔽p, called the modified p-class rank σpof K. Up to now, explicit multiplicity formulas for discriminants were known for quadratic fields with 0 ≤ σp≤ 1 only. Here, the results are extended to σp= 2, underpinned by concrete numerical examples.
A generalization of (G′/G)-expansion method and its application to nonlinear reaction–diffusion equations arising in mathematical biology
Authors: Jabbari A. , Heris J. Manafian , Kheiri H. , Bekir A.
Published: April 2014

In this paper, by introducing a proper transformation, the (G′/G)-expansion method is further extended into the nonlinear reaction–diffusion equations in mathematical biology whose balancing numbers may be negative integer. As a result, hyperbolic function solutions and trigonometric function solutions with free parameters are obtained. When the parameters are taken as special values the solitary wave solutions and the periodic wave solutions are also derived from the traveling wave solutions. Moreover, it is observed that the suggested techniques is compatible of such problems.
Synthesis, structure and electrochemical behavior of a 3D crystalline copper(II) metal-organic framework
Authors: Bai Hong-Ye , Fan Wei-Qiang , Liu Chun-Bo , Shi Wei-Dong , Yan Yong-Sheng
Published: April 2014

Using an flexible amide-type tripodal ligand N , N ′, N ″-tris(3-pyridyl)-1,3,5-benzenetricarboxamide (L) and 1,4-benzenedicarboxylic acid ( H 2 bdc ), a three-dimensional copper(II) metal-organic framework (MOF) formulated as [ Cu ( bdc )( L )]n has been hydrothermally synthesized and structurally characterized by IR, elemental, X-ray single-crystal diffraction and thermal analysis. The complex crystallizes in the triclinic, space group P - 1, a = 8.891(2) Å, b = 11.760(2) Å, c = 15.348(3) Å, α = 96.73(3)°, β = 105.96(3)°, γ = 106.47(3)°, V = 1446.2(5) Å3, Mr = 666.10, Dc = 1.530 g/cm3, Z = 2, F(000) = 682, GOOF = 1.0560, μ(MoKα) = 0.817 mm-1, R = 0.0366 and wR = 0.0885. The structural analyses reveal that the title compound consists of one Cu ( II ) atom, two halves of bdc, and one L ligand. Each Cu ( II ) atom is linked by two bdc ligands and three L ligands to form a three-dimensional network. In addition, the electrochemical behavior of title compound has been studied. CCDC No. 990526.
Vector meson-baryon octet interaction and resonances generated dynamically
Authors: Sun B.-X. , Wang Y.-W.
Published: April 2014

The interaction potentials between vector mesons and baryon octet are calculated explicitly with a summation of t-, s-, and u- channel diagrams and a contact term originating from the tensor interaction. Altogether, 13 resonances are generated dynamically in different channels of strangeness zero by solving the relativistic Lippman-Schwinger equations in the S-wave approximation, and their masses, decay widths, isospins and spins are determined. Some resonances are well fitted with their counterparts listed in the newest review of Particle Data Group (PDG),1 while others might stimulate the experimental observation in these energy regions in the future.
Skyrmions, half-skyrmions and nucleon mass in dense baryonic matter
Authors: Ma Yong-Liang , Harada Masayasu , Lee Hyun Kyu , Oh Yongseok , Rho Mannque
Published: April 2014

We explore the hadron properties in dense baryonic matter in a unified way by using a Skyrme model constructed with an effective Lagrangian which includes the ρ and ω vector mesons as hidden gauge bosons and is valid up to O(p4) in chiral expansion including the homogeneous Wess-Zumino terms. With the two input values of pion decay constant and the lowest lying vector meson mass which can be fixed in free space, all the other low energy constants in the effective Lagrangian are determined by their master formulas derived from holographic QCD models, which allows us to study the baryonic matter properties with no additional free parameters and thus without ambiguities. We find that the ω field that figures in the homogeneous Wess-Zumino term plays a crucial role in the skyrmion structure and its matter properties. The most striking and intriguing observation is that the pion decay constant that smoothly drops with increasing density in the Skyrmion phase stops decreasing at n1/2 at which the skyrmions in medium fractionize into half-skyrmions and remains nearly constant in the half-skyrmion phase. In accordance with the large Nc consideration, the baryon mass also stays non-scaling in the half-skyrmion phase. This feature is supported by the nuclear effective field theory with the parameters of the Lagrangian scaling modified at the skyrmion–half-skyrmion phase transition. Our exploration also uncovers the crucial role of the ω meson in multi-baryon systems as well as in the structure of a single skyrmion.
On mass shifts induced by the hadron-loop effects
Authors: Zhou Zhi-Yong , Xiao Zhi-Guang
Published: April 2014

In the past decades, more and more hadron states were observed by experiments. Some of them run out of the predictions of the quark potential models. In this paper, we review how to understand their masses and decays according to the hadron loop effect. Typically, this effect can solve the "low-mass" puzzle for some charmed or charmed-strange states. It also provides unified descriptions for some charmonium-like states including the X(3872) state.
Gauge invariance, canonical quantization and Poincaré covariance in nucleon structure
Authors: Wang Fan , Sun W. M. , Chen X. S. , Zhang P. M.
Published: April 2014

There are different quark and gluon momentum, spin and orbital angular momentum operators used in the study of nucleon structure. We analyze the physical contents of these operators and propose a new set of operators based on gauge invariance principle, canonical quantization rule and Poincaré covariance. Atomic structure is a simpler testing ground of these operators and has been analyzed together. These new operators are the gauge invariant version of the gauge non-invariant canonical version used in physics since the establishment of quantum mechanics and reduce to the familiar canonical ones in Coulomb gauge.
On the largest eigenvalue of products from the β-Laguerre ensemble
Authors: Gelbaum Zachary
Published: April 2014

We determine the limiting distribution of the largest eigenvalue of products from the β-Laguerre ensemble. This limiting distribution is given by a Tracy–Widom law with parameter β0 > 0 depending on the ratio of the parameters of the two matrices involved.
Synthetic Routes for the Preparation of Ordered Vanadium Oxide Inverted Opal Electrodes for Li-Ion Batteries
Authors: Armstrong Eileen , Khunsin Worawut , Sotomayor Torres Clivia M. , Osiak Michal , O'Dwyer Colm
Published: April 2014

Synthetic routes for the formation of opal assemblies as templates for the inverted opal vanadium oxide electrodes are presented. A method for the formation of monolayer opal templates on gold substrates is discussed and the formation of multilayer opal templates on conductive substrates by electrophoretic deposition is also described, with order defined by angle resolved light scattering measurements. Inverted opals are formed from a diluted solution of IPA and vanadium alkoxide precursor, infiltrated into the templates by several methods. The effect of different heat treatments and method of polymer template removal on the resulting inverse opal morphology and structure is investigated.
Selective Detection of Hydrogen Concentration in Mixture Gas with Methane Using an Electrolyte Made of Manganese Dioxide
Authors: Araki Ryota , Yoshikawa Kenichi , Koyanaka Hideki
Published: April 2014

A potentiometric type hydrogen sensor using an electrolyte made of manganese dioxide in a wet condition with water that enabled measurements of hydrogen concentration over a wide range of 1-99.9 vol. % at room temperature was previously reported. In this study, we examined a capability of the sensor to measure various hydrogen concentrations in a mixture gas of hydrogen and methane.
Solubility and Stability of Superoxide Radical Anions in Room-Temperature Ionic Liquids
Authors: Ishikawa Daisuke , Hashimoto Ayumu , Kitada Atsushi , Murase Kuniaki
Published: April 2014

Because superoxide anion is easily decomposed by the presence of proton, it is known that superoxide anion only dissolves in specific highly polar aprotic solvents such as dimethylsulfoxide. Organic solvents are dangerous due to their high volatility and flammability, while ionic liquids possess inflammability, nonvolatility, and high ion conductivity. Additionally, in the area of organic synthesis, there is a potential for a new reaction media different from existing organic reaction media. Therefore, it would be attractive to use ILs as a new reaction media and an electrolyte of batteries. In this study, we studied solubility and stability of superoxide anion in five kinds of ILs. It was found that P14,6,6,6Cl was the most suitable solvent in terms of the solubility and stability of superoxide anion.
Non-Enzymatic Selective Detection of Glucose Based on a Gold Nanoparticle- Carbon Nanotube Composite Film
Authors: Branagan David , Breslin Carmel B.
Published: April 2014

A gold nanoparticle-functionalised multi-walled carbon nanotube composite, fMWCNT-Aunano, was prepared by a simple reduction method using sodium borohydride and was used for sensing glucose non-enzymatically at neutral pH. The morphology and composition of the fMWCNT-Aunano hybrid were characterised by TEM, EDX and AA. TEM analysis indicated the gold nanoparticles to be mainly under 10 nm in size and both EDX and AA quantified the gold loading at 2% weight of composite. Constant potential amperometry was used for electrochemical detection of glucose and Nafion® membranes were employed to reduce interference from the commonly occurring AA and UA interferants, present in blood at high concentrations.
New Electrochemical Oscillation Appeared in H2O2-H2SO4-Pt System by Addition of Na2SO4 and K2SO4
Authors: Mukouyama Yoshiharu , Hasegawa Mitsuhisa , Yamamoto Shuhei , Nakanishi Shuji , Okamoto Hiroshi
Published: April 2014

We have studied the H2O2 reduction on Pt in 0.10 M H2SO4 + 0.25 M H2O2 solutions and found that a new potential oscillation, named oscillation H, appears under current controlled conditions when Na2SO4 or K2SO4 is added to the solutions. The oscillation range is between ca. 0.1 and 0.6 V, where a negative differential resistance (NDR) is formed. Oscillation H, therefore, is classified into a hidden-NDR oscillator. We have also found that oxygen bubbles evolve constantly from the electrode surface during oscillation H and showed that the local pH at the electrode surface is basic due to the presence of the salts. Therefore, the oxygen bubbles are produced probably by the catalytic decomposition of HO2
- formed via the dissociation of H2O2 at the electrode surface.
Preparation and Electrochemical Behavior of Carbonaceous Fiber Sheets Derived from Bamboo
Authors: Kinumoto Taro , Matsumura Takuya , Matsuoka Miki , Tsumura Tomoki , Toyoda Masahiro
Published: April 2014

Phyllostachys, which is generally called as “bamboo”, is one of the sustainable natural resources with high CO2 immobilization capacity and is expected to use in the next generation. In the present study, the carbonaceous sheets are prepared from phyllostachys through a series of physical, chemical and heat treatments. The average diameter of obtained single bamboo fiber was ca. 12.5 mm and is reduced by the carbonization; on the other hand, the microscopic morphology is remained “fibrous”. The electric conductivity, which is measured by four-probe method, is 35 S cm-1 after heat treatment at 2000oC in this study. From the cyclic vlotammogram obtained in in 0.1 mol dm-3 of perchloric acid aqueous solution under N2 atmosphere, significantly current flow due to an electrochemical reaction is not recognized and only electrochemical double layer capacity can be observed. The results of this study suggest that phyllostachys could be used to for the material of the electrochemical devices.
Demonstration of Enhanced Sensitivity to CO in H2 Fuel Stream of an Electrochemical Analyzer
Authors: Quesada Calita , Rockward Tommy , Garzon Fernando , Burleigh David , Mukundan Rangachary
Published: April 2014

Low levels of carbon monoxide present in hydrogen fuels can poison polymer electrolyte membrane fuel cells, therefore low cost analytical methods for detecting the presence of CO are highly desirable. We have designed an analytical electrochemical analyzer to detect trace quantities of carbon monoxide in a hydrogen fuel stream. The electrochemical analyzer operates on principles similar to those observed in CO poisoning on Pt-catalyst surfaces in polymer electrolyte fuel cells. The analysis cell consists of a low surface area sputtered Pt electrode, a Nafion® electrolyte, along with a high surface area Pt-Vulcan reference electrode. The analyzer is optimized as a hydrogen pumping cell, utilizing hydrogen on both electrodes to probe the presence of CO. The low surface area electrode consists of an unsupported Pt catalyst at 0.1mgPt/cm2 loading, pressed onto Nafion® 117 membranes with a high surface area Pt-Vulcan carbon loaded at 0.2mgPt/cm2. The analyzer exhibited a response to concentrations as low as 100 ppb CO at 30oC and 100% relative humidity.
Outer and Inner Surface Contribution of Manganese Dioxides Energy Storage Characterization by Cavity Microelectrode Technique
Authors: Athouël Laurence , Arcidiacono Paul , Ramirez-Castro Claudia , Crosnier Olivier , Guay Daniel , Bélanger Daniel , Brousse Thierry
Published: April 2014

Cryptomelane and birnessite form of manganese dioxides powders have been investigated in mild aqueous sulfate based electrolytes using the cavity microelectrode (CME) technique. The micro electrochemistry on small quantities of powder allows the study of active materials, without the use of a binder and an electronic conductor, and also can be performed at high potential cycling rates. A few hundred nanograms of the pristine isolated MnO2 powder is electrochemically characterized in sulfate based electrolytes with or without conductive acetylene black, making possible a kinetic approach highlighting the outer and inner surface contribution in manganese dioxides energy storage. The cation effect of the electrolyte is also showed.
Synthesis and Characterization of Vanadium Oxide Nanotube Electrode Material for Electrochemical Capacitors
Authors: Wei Yiying , Wang Guoxiu , Zhu Jianguo
Published: April 2014

Vanadium oxide nanotube was synthesized by hydrothermal treatment with high-speed stirring. The preparation involved dissolution of V2O5 into H2O2 and high-speed stirring (10000r/min) with hexadecylamine. The product was characterized by using scanning electron microscopy, transmission electron microscope, X-ray diffraction and thermogravimetric analysis. The electrochemical properties of the material as the electrode of electrochemical capacitor were evaluated by cyclic voltammetry in a three electrode system consisting of a saturated calomel electrode as reference electrode, platinum as a counter electrode and the active material as the working electrode. A capacitance of 297F/g was obtained at a scan rate of 2mV/s in 2M KCl, and it still maintained a high capacitance of 210F/g at a higher scan rate of 50mV/s in 2M KCl. Even though the materials achieved the highest capacitance of 304F/g in 2M LiCl at the scan rate of 2mV/s, the specific capacitance degraded significantly as the increase of the scan rate.
Fluoroethylene Carbonate and Propylene Carbonate Mixtures Based Electrolytes for Supercapacitors
Authors: Jänes Alar , Thomberg Thomas , Eskusson Jaanus , Lust Enn
Published: April 2014

The electrochemical characteristics of the electrical double layer capacitors consisting of the microporous titanium carbide derived carbon (TiC-CDC) electrode in 1M (C2H5)3CH3NBF4 solutions in 4-methyl-1,3-dioxolan-2-one, (so-called propylene carbonate (PC)), 4-fluoro-1,3-dioxalan-2-one, (so-called fluoroethylene carbonate (FEC)), and in various mixtures of named solvents like FEC:PC (1:1 volume ratio), FEC:PC (1:9) and FEC:PC (1:19) have been studied using cyclic voltammetry and electrochemical impedance spectroscopy methods. The specific capacitance, phase angle and series resistance values dependent on the solvent system used and temperature applied (from -45 ºC to 90 ºC) have been established. The region of ideal polarizability ΔE ≥ 3.0V has been demonstrated for TiC-CDC electrodes in all electrolytes and at temperatures investigated, except at T ≥ 90 ºC. Specific conductivity and viscosity values have been obtained and correlated with electrochemistry data. The limiting capacitance, the characteristic time constant and complex power values depend noticeably on the solvent used for preparation of electrolyte, i.e. on the viscosity and specific conductivity of electrolyte solution used.
Silver Electrodeposition from Ionic Liquids: Coatings Morphology and Mass Transport Issues
Authors: Cinotti Serena , Banchelli Elena , Becucci Lucia , Bencistà Ilaria , Innocenti Massimo , Lavacchi Alessandro , Luconi Leandro , Wang Lianqin
Published: April 2014

Silver electrodeposition from [Ag][BF4] solution in [BMIM][BF4] has been investigated with the purpose of understanding the effect of the deposition conditions on the morphology of the coatings. Dense and compact silver coatings with crystalline structure have been obtained with a significant reduction of the mean grain size as a result of the increase of the current density. A discussion on the electrolyte mass transport properties and their influence in the deposition rate is also reported.
DFT Analysis on Cathodic Reaction of Au Thiosulfate Complex at Au(111) Surface – Cathodic Reaction Modeling
Authors: Kunimoto Masahiro , Nakai Hiromi , Homma Takayuki
Published: April 2014

We attempted to theoretically investigate cathodic reaction of Au thiosulfate complex at Au (111) surface. Theoretical model of the solid-liquid interface was built using density functional theory calculation and Monte-Carlo method. As a comparison, the cathodic reaction of Au cyanide complex is also analyzed. Calculated results from this model successfully reproduced behavior of the reactions of two complexes. Furthermore, detailed analyses on the results indicated that total charge, dipole moment, and end atom of coordinates play key roles to determine the reactivity of complexes.
A Spontaneous Morphology Change on the Surface of Electrodeposited Single-Crystal Copper Films during Room-Temperature Aging
Authors: Nakahara Shohei , Ahmed Shafaat , Buckley D. Noel
Published: April 2014

During room-temperature aging, a morphological transition described as a spontaneous morphology change was discovered to occur on the surface of single-crystal copper electrodeposits grown epitaxially on {001} copper substrates. Within half to two hours after the completion of deposition, well-defined periodic contour lines appeared suddenly around the originally smooth-faced pyramids. These contour lines were thought to represent periodic cracks/steps, which were formed to relieve tensile stress developed as a result of surface annihilations of excess vacancies trapped in the deposits. Thus the formation of these lines was phenomenologically the same as the sudden appearance of fine grains observed previously on the surface of polycrystalline copper electrodeposits during room-temperature aging.
Porous Silicon with Deposited Iron Oxide as Vehicle for Magnetically Guided Drug Delivery
Authors: Rumpf Klemens , Granitzer Petra , Tian Yuan , Coffer Jeffery , Akkaraju Giri , Poelt Peter , Michor H.
Published: April 2014

Due to the fact that both materials porous silicon as well as iron oxide nanoparticles are biocompatible and porous silicon can be functionalized easily to attach therapeutic nucleotides the aim is to create a cytocompatible arrangement to promote magnetically guided delivery into targeted cells. Furthermore porous silicon dissolves in body fluid dependent on the porosity which increases the possible applications. Within the frame of this work the field and temperature dependent magnetic properties of the nanocomposite have been investigated as well as its cytocompatibility according to the porous silicon morphology and the iron oxide particle size.
SECM Dissolution Studies of Pasted Battery Cathodes in Ionic Liquid Electrolytes
Authors: Snook Graeme Andrew , Huynh Thuy Diem , Best Adam Samuel
Published: April 2014

This work aims to detect the instability of cathode materials in alternate battery electrolytes known as room temperature ionic liquids. For this purpose, the scanning electrochemical microscope (SECM) has been used to detect solubilisation of species leaving LiCoO2 battery material while cycling in the ionic liquid electrolyte. In this work, LiCoO2 / binder / conducting carbon mixes were pasted onto aluminium foil current collectors to simulate the behaviour in a real battery system. Here, dissolution of cobalt in overcharge conditions is observed. The added complication is that at higher voltages the aluminium current collector becomes unstable and begins to corrode. Evidence for the combined dissolution of aluminium ions and cobalt ions is presented in this work.
Understanding the Influence of Carbon on the Oxygen Reduction and Evolution Activities of BSCF/Carbon Composite Electrodes in Alkaline Electrolyte
Authors: Mohamed Rhiyaad , Fabbri Emiliana , Levecque Pieter , Kötz Ruediger , Schmidt Thomas J. , Conrad Olaf
Published: April 2014

The influence of carbon on the oxygen reduction and evolution reactions (ORR and OER) on Ba0.5Sr0.5Co0.8Fe0.2O3-δ (BSCF) perovskite oxide has been studied in alkaline electrolyte. A lowering of the ORR overpotential by 100 mV for the BSCF/Carbon composite electrode compared to BSCF without carbon was observed, while for the OER the overpotential was reduced by some 65 mV. The results of this work suggest that the carbon present in the composite electrodes acts as more than a simple conductivity-improving agent and enhances the electrocatalytic activity of the oxide significantly.
High Surface Area Carbon Electrodes for the Bromine Reactions in H2-Br2 Fuel Cells
Authors: Yarlagadda Venkata , Nguyen Trung Van
Published: April 2014

The H2-Br2 system is considered as one of the viable options for large scale electrical energy storage due to faster H2 and Br2 reaction kinetics, low cost, and high round-trip efficiency. In order to improve the performance of the H2-Br2 fuel cell, carbon electrodes with high active surface area are needed. A preliminary study was conducted to synthesize and characterize the carbon nanotube based electrodes. Based on the results obtained from SEM, TEM, and EDX analysis, multi-wall carbon nanotube growth is confirmed. Also, the results from the multi-step chronoamperometry study have shown that the active areas of carbon nanotube electrodes are significantly higher than a plain carbon electrode.
The Electrolyte Monitoring of a Vanadium Redox Flow Battery
Authors: Al-Fetlawi Hassan Abdul-Zehra
Published: April 2014

A series of carbon felts was examined by cyclic voltammetry to investigate their suitability as an electrode material for the all-vanadium redox flow battery. A commercially supplied vanadium electrolyte of unknown concentration was analysed by UV-visible spectroscopy and was shown to contain VO2+ and V3+ ions in a ratio of 4.8:1 with a total vanadium concentration of 1.5 mol dm-3 in 4 mol dm-3 H2SO4. A unit laboratory redox flow battery (100 cm2 membrane area) was assembled using carbon felts and planar carbon feeders as the positive and negative electrodes with a Nafion® 115 proton exchange membrane. Its performance was examined using both 1.5 mol dm-3 and 1.1 mol dm-3 vanadium electrolytes at volumetric flow rates in the range of 0.5 to 3 cm3 min-1. At a vanadium concentration of 1.1 mol dm-3, a suitable volumetric flow rate was found to be in the range1.5 – 2.0 cm3 min-1. At a constant current density charge and discharge of 100 mA cm-2 for 45 minute half-cycles (and <30 cycles), the typical voltage efficiencies were 65 %.
Microbial Fuel Cell as an Alternative for Glycerin Utilization
Authors: Queiroz Guimarães Amanda , Linares José J
Published: April 2014

A glycerol-based microbial fuel cells was implemented based on activated sludge from a Wastewater Treatment Plant (WWTP). The influence of the substrate concentration was studied, observing a Monod-type behavior for the cell performance (cell voltage under closed circuit and power output) and the TSS, without improvement when the glycerol concentration in the influent exceeded 1080 mg.L-1. Under these conditions, the electrochemical performance did not rely on the substrate availability, but on the limited capability of the microorganism for electroxidating glycerol. In terms of the coulombic efficiency, half of the organic matter is degraded with simultaneous generation of electricity for a glycerol concentration of 320 mg L-1 in the influent, reducing at higher glycerol concentrations down to 20%. Finally, the anode appeared as the governing electrode, whose performance varied significantly with the glycerol concentration.