bluuebunny/crossref_metadata_2025 huggingface dataset:
Medication use in relation to noise from aircraft and road traffic in six European countries: results of the HYENA study
Authors: Floud Sarah , Vigna-Taglianti Federica , Hansell Anna , Blangiardo Marta , Houthuijs Danny , Breugelmans Oscar , Cadum Ennio , Babisch Wolfgang , Selander Jenny , Pershagen Göran , Antoniotti Maria Chiara , Pisani Salvatore , Dimakopoulou Konstantina , Haralabidis Alexandros S , Velonakis Venetia , Jarup Lars
Published: November 2010

Objectives

Studies on the health effects of aircraft and road traffic noise exposure suggest excess risks of hypertension, cardiovascular disease and the use of sedatives and hypnotics. Our aim was to assess the use of medication in relation to noise from aircraft and road traffic.

Methods

This cross-sectional study measured the use of prescribed antihypertensives, antacids, anxiolytics, hypnotics, antidepressants and antasthmatics in 4,861 persons living near seven airports in six European countries (UK, Germany, the Netherlands, Sweden, Italy, and Greece). Exposure was assessed using models with 1dB resolution (5dB for UK road traffic noise) and spatial resolution of 250×250m for aircraft and 10×10m for road traffic noise. Data were analysed using multilevel logistic regression, adjusting for potential confounders.

Results

We found marked differences between countries in the effect of aircraft noise on antihypertensive use; for night-time aircraft noise, a 10dB increase in exposure was associated with ORs of 1.34 (95% CI 1.14 to1.57) for the UK and 1.19 (1.02 to 1.38) for the Netherlands but no significant associations were found for other countries. For day-time aircraft noise, excess risks were found for the UK (OR 1.35; CI: 1.13 to 1.60) but a risk deficit for Italy (OR 0.82; CI: 0.71 to 0.96). There was an excess risk of taking anxiolytic medication in relation to aircraft noise (OR 1.28; CI: 1.04 to 1.57 for daytime and OR 1.27; CI: 1.01 to 1.59 for night-time) which held across countries. We also found an association between exposure to 24hr road traffic noise and the use of antacids by men (OR 1.39; CI 1.11 to 1.74).

Conclusion

Our results suggest an effect of aircraft noise on the use of antihypertensive medication, but this effect did not hold for all countries. Results were more consistent across countries for the increased use of anxiolytics in relation to aircraft noise.
"SCHWINGER MODEL" ON THE FUZZY SPHERE
Authors: HARIKUMAR E.
Published: November 2010

In this paper, we construct a model of spinor fields interacting with specific gauge fields on the fuzzy sphere and analyze the chiral symmetry of this "Schwinger model". In constructing the theory of gauge fields interacting with spinors on the fuzzy sphere, we take the approach that the Dirac operator Dq on the q-deformed fuzzy sphere [Formula: see text] is the gauged Dirac operator on the fuzzy sphere. This introduces interaction between spinors and specific one-parameter family of gauge fields. We also show how to express the field strength for this gauge field in terms of the Dirac operators Dq and D alone. Using the path integral method, we have calculated the 2n-point functions of this model and show that, in general, they do not vanish, reflecting the chiral non-invariance of the partition function.
QUANTUM INTERFERENCE EFFECTS IN HOŘAVA–LIFSHITZ GRAVITY
Authors: HAKIMOV ABDULLO , TURIMOV BOBUR , ABDUJABBAROV AHMADJON , AHMEDOV BOBOMURAT
Published: November 2010

The relativistic quantum interference effects in the spacetime of slowly rotating object in the Hořava–Lifshitz gravity as the Sagnac effect and phase shift of interfering particle in neutron interferometer are derived. We consider the extension of Kehagias–Sfetsos (KS) solution48 in the Hořava–Lifshitz gravity for the slowly rotating gravitating object. Using the covariant Klein–Gordon equation in the nonrelativistic approximation, it is shown that the phase shift in the interference of particles includes the gravitational potential term with the KS parameter ω. It is found that in the case of the Sagnac effect, the influence of the KS parameter ω is becoming important due to the fact that the angular velocity of the locally non-rotating observer is increased in Hořava gravity. From the results of the recent experiments50 we have obtained lower limit for the coupling KS constant as ω ≃ 1.25 ⋅10-25 cm -2. Finally, as an example, we apply the obtained results to the calculation of the UCN (ultra-cold neutrons) energy level modification in the gravitational field of slowly rotating gravitating object in the Hořava–Lifshitz gravity.
QCD AT NONZERO TEMPERATURE: BULK PROPERTIES AND HEAVY QUARKS
Authors: PETRECZKY PÉTER
Published: November 2010

We review recent progress in lattice QCD at nonzero temperature with emphasis on the calculations of equation of state and the properties of heavy quark–anti-quark pairs at high temperatures. We also briefly discuss the deconfinement and chiral symmetry restoring aspects of the QCD transition at finite temperature.
DARK ENERGY IN PRACTICE
Authors: SAPONE DOMENICO
Published: November 2010

In this paper we review a part of the approaches that have been considered to explain the extraordinary discovery of the late time acceleration of the Universe. We discuss the arguments that have led physicists and astronomers to accept dark energy as the current preferable candidate to explain the acceleration. We highlight the problems and the attempts to overcome the difficulties related to such a component. We also consider alternative theories capable of explaining the acceleration of the Universe, such as modification of gravity. We compare the two approaches and point out the observational consequences, reaching the sad but foresightful conclusion that we will not be able to distinguish between a Universe filled by dark energy or a Universe where gravity is different from General Relativity. We review the present observations and discuss the future experiments that will help us to learn more about our Universe. This is not intended to be a complete list of all the dark energy models but this paper should be seen as a review on the phenomena responsible for the acceleration.

Moreover, in a landscape of hardly compelling theories, it is an important task to build simple measurable parameters useful for future experiments that will help us to understand more about the evolution of the Universe.
ANALYSIS OF pp AND $\bar pp$ ELASTIC SCATTERING BASED ON HIGH ENERGY BOUNDS
Authors: CAMPOS S. D. , OKOROKOV V. A.
Published: November 2010

Considering the Froissart–Martin bound, Jin–Martin–Cornille bound and the optical theorem, we propose a novel parametrization for the total cross-section of proton–proton and antiproton–proton elastic scattering data. Using derivative dispersion relations we obtain the real part of the elastic scattering amplitude and thus the ρ parameter. Simultaneous fits to σtot and ρ are performed allowing very good statistical descriptions of the available data. Furthermore, predictions to σtot and ρ at energies not used in the fit procedures are presented. For σtot we obtain predictions at RHIC, LHC and future hadron collider energies.
DETERMINATION OF LIGHT QUARK MASSES IN QCD
Authors: DOMINGUEZ C. A.
Published: November 2010

The standard procedure to determine (analytically) the values of the quark masses is to relate QCD two-point functions to experimental data in the framework of QCD sum rules. In the case of the light quark sector, the ideal Green function is the pseudoscalar correlator which involves the quark masses as an overall multiplicative factor. For the past thirty years this method has been affected by systematic uncertainties originating in the hadronic resonance sector, thus limiting the accuracy of the results. Recently, a major breakthrough has been made allowing for a considerable reduction of these systematic uncertainties and leading to light quark masses accurate to better than 8%. This procedure will be described in this talk for the up-, down-, strange-quark masses, after a general introduction to the method of QCD sum rules.
GAUGE SYMMETRY IN PHASE SPACE CONSEQUENCES FOR PHYSICS AND SPACE–TIME
Authors: BARS ITZHAK
Published: November 2010

Position and momentum enter at the same level of importance in the formulation of classical or quantum mechanics. This is reflected in the invariance of Poisson brackets or quantum commutators under canonical transformations, which I regard as a global symmetry. A gauge symmetry can be defined in phase space (XM, PM) that imposes equivalence of momentum and position for every motion at every instant of the worldline. One of the consequences of this gauge symmetry is a new formulation of physics in space–time. Instead of one time there must be two, while phenomena described by one-time physics in 3+1 dimensions appear as various "shadows" of the same phenomena that occur in 4+2 dimensions with one extra space and one extra time dimensions (more generally, d+2). The 2T-physics formulation leads to a unification of 1T-physics systems not suspected before and there are new correct predictions from 2T-physics that 1T-physics is unable to make on its own systematically. Additional data related to the predictions, that provides information about the properties of the extra 1-space and extra 1-time dimensions, can be gathered by observers stuck in 3+1 dimensions. This is the probe for investigating indirectly the extra 1+1 dimensions which are neither small nor hidden. This 2T formalism that originated in 1998 has been extended in recent years from the worldline to field theory in d+2 dimensions. This includes 2T field theories that yield 1T field theories for the Standard Model and General Relativity as shadows of their counterparts in 4+2 dimensions. Problems of ghosts and causality in a 2T space-time are resolved automatically by the gauge symmetry, while a higher unification of 1T field theories is obtained. In this paper the approach will be described at an elementary worldline level, and the current status of 2T-physics will be summarized.
DOMAIN DECOMPOSITION FOR POROELASTICITY AND ELASTICITY WITH DG JUMPS AND MORTARS
Authors: GIRAULT V. , PENCHEVA G. , WHEELER M. F. , WILDEY T.
Published: November 2010

We couple a time-dependent poroelastic model in a region with an elastic model in adjacent regions. We discretize each model independently on non-matching grids and we realize a domain decomposition on the interface between the regions by introducing DG jumps and mortars. The unknowns are condensed on the interface, so that at each time step, the computation in each subdomain can be performed in parallel. In addition, by extrapolating the displacement, we present an algorithm where the computations of the pressure and displacement are decoupled. We show that the matrix of the interface problem is positive definite and establish error estimates for this scheme.
DISTAL RADIAL AND ULNAR LANDMARKS USED IN PERCUTANEOUS PIN FIXATION: ANATOMICAL RELATIONSHIP TO THE SUPERFICIAL RADIAL AND ULNAR NERVES
Authors: Tryfonidis M. , Charalambous C. P. , Mills S. P. , Jass G. K. , Jacob S. , Stanley J. K. , Hayton M. J.
Published: November 2010

Background: The radial and ulnar styloids as well as Lister's tubercle are important surgical landmarks in the surgical treatment of distal forearm fractures. There have been limited studies assessing their relative safety in terms of their distance from superficial nerves which are in danger during surgical procedures. The aim of this cadaveric study was to assess and compare the distance of superficial nerves to these important surgical landmarks.

Methods: Twenty embalmed cadaveric upper limbs were dissected exposing the nerves and tendons around the wrist. The radial styloid, Lister's tubercle, ulnar styloid and nerve branches were marked with pins. The distance of the nearest nerve branch to each landmark was measured with a digital calliper. Statistical analysis of the data was performed using SPSS for Windows 11.5 (SPSS Inc., Chicago, IL) using Friedman Tests and Wilcoxon Signed Ranks tests.

Results: The median distance of the nearest nerve branch to the radial styloid was 5.42 mm, to the Lister's tubercle was 16.68 mm and to the ulnar styloid was 13.56 mm. There was unequal safety for these three surgical landmarks regarding proximity to nerve branches (p < 0.00001). Paired comparison using Wilcoxon Signed Ranks Test showed that the Lister's tubercle was safer than the radial styloid (p < 0.0001) and ulnar styloid (p = 0.04). In addition, the ulnar styloid was safer than the radial styloid (p < 0.001).

Conclusions: There is a higher risk of injury to superficial nerves when operating near the radial styloid as it is significantly closer to nerve branches as compared to Lister's tubercle and ulnar styloid.
DORSALLY DISPLACED FRACTURES OF THE DISTAL RADIUS — A STUDY OF PREFERRED TREATMENT OPTIONS AMONG UK TRAUMA AND ORTHOPAEDIC SURGEONS
Authors: Hull P. , Baraza N. , Whalley H. , Brewster M. , Costa M.
Published: November 2010

Distal radius fractures are common, and surgeons have in their armament a variety of ways of treating them. In this study, 50 orthopaedic surgeons in the UK were shown five clinical scenarios and radiographs from patients with various fracture patterns of the distal radius, and were asked for their preferred management. There was a wide variation in the preferred treatment for each scenario presented. Across all of the cases, 52% of surgeons preferred to use a volar locking-plate compared with 21% who chose fixation with Kirschner wires. There was very little consensus among surgeons with regard to the optimal method of fixation for patients sustaining dorsally displaced fractures of the distal radius. This disagreement is not surprising as there is currently no high level evidence to guide surgeons as to the best management option for this common and potentially debilitating injury.
HIGH RESOLUTION ULTRASONOGRAPHY OF THE HAND AND WRIST: THREE-YEAR EXPERIENCE AT A DISTRICT GENERAL HOSPITAL TRUST
Authors: Chan J. K. K. , Choa R. M. , Chung D. , Sleat G. , Warwick R. , Smith G. D.
Published: November 2010

A retrospective analysis of 227 patients undergoing ultrasonography (US) of the hand/wrist over a three-year period in a district general hospital trust was performed. The usefulness in each case was assessed by two independent reviewers using a qualitative rating system, as (A) Useful: determines management, (B) Useful: contributory, (C) Not useful: not misleading, or (D) Not useful: misleading/potentially harmful. US was useful in 74.8% of cases but misleading/potentially harmful in 13.1%. Misleading rates exceeding 10% in sub-categories including tendinopathy, carpal tunnel syndrome, foreign body and lumps, where US findings may influence the decision to operate or not, are particularly worrying. There were a number of cases where US led to unnecessary operations or suggested operating on the wrong structures, and also cases where US findings wrongly suggested that surgery was unnecessary. Various recommendations aimed to improve the usefulness of US in the Hand and Wrist, including mandatory/formal musculoskeletal US training, are made.
A WORKING CLASSIFICATION FOR THE MANAGEMENT OF SCAPHO-TRAPEZIUM-TRAPEZOIDOSTEO-ARTHRITIS
Authors: Westhuizen Johan van der , Mennen Ulrich
Published: November 2010

Osteo-arthritis (OA) of the scapho-trapezium-trapezoid joint (STT) is the second most common involved joint after trapezium-metacarpal I OA in the wrist.

The possible aetiology causing or contributing to the development of STT OA is shortly discussed.

A working classification is then proposed, which assists in the management of STT OA.
HOW I DEVELOPED THE WORLD'S FIRST EVIDENCE-BASED ENDOSCOPIC MANAGEMENT OF CARPAL TUNNEL SYNDROME
Authors: Okutsu Ichiro
Published: November 2010

Carpal tunnel syndrome has been surgically treated by release of the transverse carpal ligament (flexor retinaculum of the hand) using a blind procedure since 1930 or by an open procedure since 1946. The blind procedure has the possibility of unreliable results and ensuing complications, hence, the open procedure was developed. The open procedure, however, also resulted in various complications as reported in the 1970s.

At the end of the 1970s, I had many questions regarding accepted surgical procedures for treatment of carpal tunnel syndrome. These included: "Why should any healthy tissue be injured?"; "How can I make operations as minimally invasive as possible?"; and "How can I shorten postoperative fixation periods that cause declines in activities of daily living?"

This paper describes how I developed the world's first evidence-based endoscopic management procedure for carpal tunnel syndrome using local anaesthesia without a pneumatic tourniquet on an outpatient basis.
ACCESSORY EXTENSOR DIGITI MINIMI MUSCLE SIMULATING A SOFT TISSUE MASS DURING SURGERY: A CASE REPORT
Authors: Natsis Konstantinos , Papathanasiou Efthymia , Anastasopoulos Nikolas
Published: November 2010

During a wrist ganglion excision originating at the tendon sheath of the extensor carpi ulnaris muscle, a soft tissue mass was observed just radial and distal to the surgical field. Dissection of the mass revealed an accessory extensor digiti minimi muscle belly which joined the radial extensor digiti minimi tendon. The surgical impact is discussed.
MYCOBACTERIUM MARINUMINFECTION OF THE DEEP STRUCTURES OF THE HAND AND WRIST: 25 YEARS OF EXPERIENCE
Authors: Cheung Jason Pui Yin , Fung Boris Kwok-Keung , Ip Wing-Yuk
Published: November 2010

Mycobacterium marinum infection could have various presentations, from superficial skin infection to deep structure destruction. The prognosis is relatively poor when deep structure is involved as it is more destructive. The prognosis is even worse when operation is required. In the retrospective study of 136 patients who suffered this disease with deep structure involvement, their clinical presentations could be classified into benign and aggressive type. It was found that both types of presentation could be treated conservatively by medication alone. Benign presentations could be treated successfully with chemotherapy alone without complications. Patients with aggressive presentation were usually associated with worse prognosis as there were more complications regardless of the management option. Therefore, the clinical presentation not only had prognostic value but could also guide the treatment plan.
SIMULTANEOUS FRACTURE OF THE WAIST OF THE SCAPHOID AND THE HOOK OF THE HAMATE
Authors: Komura Shingo , Suzuki Yasushi , Ikehata Tatsuya
Published: November 2010

A case of simultaneous fracture of the waist of the scaphoid and the hook of the hamate is presented. The scaphoid fracture was treated surgically with a headless compression screw, while the hook fracture was treated conservatively with cast immobilisation for eight weeks. Both fractures achieved bone union and the patient returned to work without any symptoms or complications.

Only two cases of fractures of the scaphoid and hamate have been reported previously. However, both of them involved fracture of the body of the hamate. This is the first report of simultaneous fracture of the scaphoid and the hook of the hamate.
ANATOMICAL STUDY OF ARCADE OF STRUTHERS
Authors: Tiyaworanan Piyapong , Jianmongkol Surut , Thammaroj Tala
Published: November 2010

The incidence and the anatomical location of the arcade of Struthers as related to the arm length were studied in 62 arms of adult fresh-frozen cadavers. The distance between the greater tuberosity and the lateral epicondyle was designated as the arm length. The arcades of Struthers were identified in 85.4%. The mean arm length was 27.85 ± 1.3 cm. The mean of the distance between proximal border of the arcade of Struthers and the medial humeral epicondyle was 8.24 ± 2.06 cm. The mean ratio between the distance from the proximal border of the arcade to the tip of the medial epicondyle and arm length was 0.29 ± 0.07. We concluded that the anatomical location of the arcade as related to the arm length was 29% proximally, from the tip of the medial epicondyle. This report of the anatomical location of the arcade of Struthers related to the arm length can be useful to identify this structure in the arms which have differences in arm length during the surgical exploration and anterior transposition of the ulnar nerve procedures.
ON THE UNBIASED ESTIMATOR OF THE EFFICIENT FRONTIER
Authors: BODNAR OLHA , BODNAR TARAS
Published: November 2010

In the paper, we derive an unbiased estimator of the efficient frontier. It is shown that the suggested estimator corrects the overoptimism of the sample efficient frontier documented in Siegel and Woodgate (2007). Moreover, an exact F-test on the efficient frontier is presented.
CREDIT RISK PREMIA AND QUADRATIC BSDEs WITH A SINGLE JUMP
Authors: ANKIRCHNER STEFAN , BLANCHET-SCALLIET CHRISTOPHETTE , EYRAUD-LOISEL ANNE
Published: November 2010

This paper is concerned with the determination of credit risk premia of defaultable contingent claims by means of indifference valuation principles. Assuming exponential utility preferences we derive representations of indifference premia of credit risk in terms of solutions of Backward Stochastic Differential Equations (BSDE). The class of BSDEs needed for that representation allows for quadratic growth generators and jumps at random times. Since the existence and uniqueness theory for this class of BSDEs has not yet been developed to the required generality, the first part of the paper is devoted to fill that gap. By using a simple constructive algorithm, and known results on continuous quadratic BSDEs, we provide sufficient conditions for the existence and uniqueness of quadratic BSDEs with discontinuities at random times.
DELEGATED MANAGEMENT IN DYNAMIC DUOPOLIES
Authors: PETKOV VLADIMIR P.
Published: November 2010

This paper studies the commitment value of delegation in a model of dynamic competition. We argue that separating ownership and control delivers an instantaneous first-mover advantage. Thus, delegation would enable an oligopolistic firm to increase its equilibrium profit relative to direct management. We focus on remuneration strategies that provide managers with intertemporal production incentives: future wages depend on current effort. Their composition and functional form are endogenously determined by the requirement for Markov perfection. For the case of linear-quadratic payoffs, we obtain a closed-form solution for the equilibrium wage strategies which is independent of industry structure.
STRATEGIC CHOICE BETWEEN PROCESS AND PRODUCT INNOVATION UNDER DIFFERENT COMPETITIVE REGIMES
Authors: FILIPPINI LUIGI , MARTINI GIANMARIA
Published: November 2010

This paper investigates the strategic choice between introducing a process or a product innovation in a duopoly model with vertical differentiation, comparing the outcomes in case of Bertrand and Cournot competition. It is shown that under both competitive regimes three equilibria in innovation adoption may arise: two symmetric equilibria, where firms select the same innovation type, and one asymmetric equilibrium. The competitive regime has an impact on the features of the asymmetric equilibrium, since in case of Bertrand competition, the high (low) quality firm chooses a product (process) innovation, while firms make the opposite choices in case of Cournot competition. The presence of a leapfrogging effect (only in the Cournot case) explains these different outcomes. Last, we find that the Cournot competitors tend to favor the introduction of a new product in comparison with the Bertrand competitors.
THE ISSUE OF TIME INCONSISTENCY REVISITED AS AN EXTENDED GAME
Authors: CELLINI ROBERTO , LAMBERTINI LUCA
Published: November 2010

We reformulate the monetary policy model of Barro and Gordon (1983a) by using an extended game with observable delay where the hierarchy of play between the central bank and the private sector is endogenous. This allows us to endogenise the institutional setup wherein the monetary policy game takes place. We show that positive inflation may be observed due to mixed strategies rather than time inconsistency.
THE AUMANN-DRÈZE VALUE, THE WIESE VALUE, AND STABILITY: A NOTE
Authors: TUTIC ANDREAS
Published: November 2010

In this note we present an example of a TU game where both the value presented by Aumann and Drèze (1974) and the value introduced by Wiese (2007) do not exhibit a stable coalition structure.
SINGLE-WALLED NANOTUBES AS KIRCHHOFF ELASTICAS
Authors: AGNIHOTRI PRABHAT K. , BASU SUMIT
Published: November 2010

Under compressive loads, single-walled carbon nanotubes (SWNTs) are known to behave like cylindrical shells at small aspect ratios and undergo a shell to column transition at somewhat larger aspect ratios. At even larger aspect ratios SWNTs are capable of undergoing large elastic deformations without suffering localized plastic kinks. In this work, we show that a very long SWNT can be modeled as a Kirchhoff elastica with a small initial twist. The elastic properties of the nanotubes, required to model them as elastica, are obtained from MD simulations on short SWNTs. The total twist on particular straight nanotube depends on its length, diameter and chirality and though small, affects the post buckling deformation of long nanotubes significantly. The modeling of a long SWNT as a twisted elastica may be effectively used to search for their possible folded and coiled equilibrium configurations under various ambient conditions.
MESOPOROUS CARBON ELECTRODE: SYNTHESIS, CHARACTERIZATION AND ELECTROCHEMICAL PROPERTIES
Authors: LONG XI , ZHAO CHUNXIA , CHEN WEN
Published: November 2010

The present paper studies a kind of mesoporous carbon (MC) with high electrochemical performance, which was prepared by vapor infiltration method. The microstructure and electrochemical properties of the mesoporous carbon were investigated by transmission electron microscopy (TEM), nitrogen adsorption–desorption isotherms, cyclic voltammetry (CV), constant current charge–discharge cycling (CD), and the long-term stability test. The results indicated that the mesoporous carbon has an ordered mesoporous structure, with pore size of about 3.87 nm and surface areas of 1087 m2 ⋅ g-1. The cyclic voltammetry curve reveals typical electrical double-layer capacitor property. After 200 cycles, the CV curves can almost be overlapped, which indicates excellent cycling stability. From the charge/discharge cycling, the specific capacitance of MC is 117 F ⋅ cm-1 in 1.0 M KNO3 electrolyte media at a scan rate of 1.0 mV ⋅ s-1, which decays with increasing current density. The charge–discharge efficiency also decays with it.
SYNTHESIS AND CHARACTERIZATION OF A RODLIKE LIQUID CRYSTALLINE POLYURETHANE OLIGOMER
Authors: WEI CHUN , GAO QIU-SHAN , GONG YONG-YANG , XIONG XUE-MEI , SHEN XIN
Published: November 2010

A novel rodlike liquid crystalline polyurethane (LCPU) oligomer was synthesized by polyaddition of hexane-1,6-diylbis(4-hydroxybenzoate) with toluene 2,4-diissocyanate in N, N′-dimethylformamide solution. The properties of the LCPU oligomer were investigated by FT-IR, DSC, TGA, POM, WAXD and SEM. The LCPU oligomer was a yellow powder at room temperature, which maintained a stable rodlike microstructure below its melting point, and had high crystallinity. The LCPU oligomer exhibited thermotropic liquid crystalline properties between 166–183°C, and the smectic-A phase with focal conic fan textures at the liquid crystal state was observed by POM. The decomposition temperature of the LCPU oligomer at 5% weight loss was 282°C.
STUDY OF HYDROTHERMAL SYNTHESIS AND PROPERTIES OF Bi2Fe4O9
Authors: WANG YIBO , SUN HUAJUN , ZHOU JING , LI BO , ZHANG CHENGYONG , CHEN WEN
Published: November 2010

Highly oriented Bi2Fe4O9 nanosheets can be fabricated with Fe(NO3)3 ⋅ 9H2O and Bi(NO3)3 ⋅ 5H2O using the low-temperature hydrothermal method. The as-prepared powders are characterized with X-ray diffraction (XRD), scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HRTEM), which exhibit an excellent orientation along the (00l) planes. The leakage current density and dielectric properties of the nanosheet samples are measured by Radiant Precision Workstation and HP4291B Impedance Analyzer, respectively. The effects of NaOH concentration on the phase transformation, sheet size and morphologies of the Bi2Fe4O9 crystallites are studied in this paper.
A SYNTHESIS ROUTE FOR LITHIUM IRON PHOSPHATE PREPARED BY IMPROVED COPRECIPITATION
Authors: ZHANG JUN-XI , XU MING-YU , CAO XIAO-WEI , XU NA , LAI CHUN-YAN , YAN LI-CHENG
Published: November 2010

Pure lithium iron phosphate and Mo -doped lithium iron phosphate were synthesized via improved coprecipitation, followed by spray dry processing and sintering at a high temperature for crystallization. The synthesis was based on a key step to promote the dissolution of Fe powder by the addition of Cu or CuO powder in phosphoric acid solution. The improved coprecipitation process could achieve homogeneous mixing of the reactants at the molecular level. The crystalline particle size of the LiFePO4 was between 20 and 70 nm. All the samples were pure single-phase indexed with orthorhombic Pnmb space group. The electrochemical performance of LiFe0.96Mo0.04PO4 , including its reversible capacity, cycle number and charge–discharge characteristics, were all better than those of pure LiFePO4 .
IMPROVEMENT ON THE ELECTROCHEMICAL PROPERTIES OF LiMn2O4 BY CODOPING
Authors: WANG JUN-FANG , ZHANG HAI-LANG
Published: November 2010

The cathode materials Li 1.05 Cr x Mn 1.95-x O 4(x = 0, 0.05, 0.10) for lithium ion batteries were synthesized by sol–gel method and calcined at 650, 700 and 750°C, respectively. The synthesized materials were characterized with X-ray diffraction (XRD). The electrochemical performances of the materials were tested by constant-current cyclic testing at room temperature for 38 cycles. The XRD results showed that the samples of cathode materials synthesized by the method possessed pure spinel phase. The Li1.05Cr0.1Mn1.85O4 powder with better cyclic performance of initial specific discharge capacity of 113.7 mAh ⋅ g-1 can be obtained at the calcination temperature of 700°C for 12 h, with an capacity retention of 95.5% after 38 cycles. It was evident that codoping of Li+ and Cr3+ can improve the stability of spinel structure and cycling performance.
CORE/SHELL STRUCTURED NANOCOMPOSITES FOR ELECTRODE MATERIALS OF LITHIUM ION BATTERIES
Authors: DUAN JIYUAN , WEI BIWEN , YANG RONGJING , PAN JIAZHEN
Published: November 2010

New materials are of great importance for further development of lithium ( Li ) ion batteries. This paper reviews the latest development on core/shell structured nanocomposites. Due to different roles of the cores and the shells, the nanocomposites can be tailored to improve their electrochemical performance. Finally, further directions are pointed out.
STUDY ON THE STRUCTURE, COMPOSITION AND PERFORMANCE OF NATURAL POLYMER
Authors: WEN JING , WANG QUN , JIN QIONGHUA , PAN ZELIN
Published: November 2010

The sunflower stem core is one kind of natural polymer material. Its structure presents obvious structure gradient from the center to outer part. This article mainly focuses on the relationship between nature of cell walls and the mechanical properties of sunflower stem core. The mechanical properties recorded by the universal testing machine; the cell wall's chemical composition, the cellulose crystallinity and the microfibril angle were measured using the chemical analysis method and X-ray powder diffraction. Research shows that the Young modulus of outer part is nearly 3 times more than that of center part, while the yield strength is 2.5 times more than that of center part. The main components of the sunflower stem core are cellulose, hemicellulose and lignin. The amount of those three components is about 70% of the total dry weight. The contents in the center and outer part are slightly different. The difference of crystallinity and microfibril angle between the center and outer part are quite small, which are 41.39–41.49% and 29.64–27.20%, respectively. Therefore, the results suggested that the nature of cell walls has little influence to the difference of mechanical properties between the center and outer part, and the cell structure is the main reason.
GLYCINE-ASSISTED SOL–GEL SYNTHESIS OF LiFePO4/C CATHODE MATERIALS FOR LITHIUM-ION BATTERIES
Authors: HU SHIGUANG , ZHANG TIANJING , CAO HUJUN , ZHANG HONGMEI , LI ZHAOHUI , LEI GANGTIE
Published: November 2010

Glycine was firstly used as a chelating agent to prepare LiFePO4/C cathodes by the sol–gel process and sucrose as carbon source. The effects of calcination temperature on properties of LiFePO4/C cathode were investigated using scanning electron microscope (SEM), X-ray diffraction (XRD), galvanostatic charge-discharge and cyclic voltammogram (CV) respectively. The XRD patterns indicate that all samples were of good crystallinity. The primary particle size increased with the calcination temperature from 600 to 750°C. The LiFePO4/C sample synthesized at 700°C has the best electrochemical performance with an initial discharge capacity of 162.6 mAh g-1 at 0.1 C and the discharge capacity remains at 154.6 mAh g-1 after 50 cycles.
Challenges in reservoir engineering from prospects for horizontal wells
Authors: Fayers F. J. , Arbabi S. , Aziz K.
Published: November 2010

In this review paper, a variety of reservoir applications are illustrated where horizontal wells can have advantages over the use of conventional vertical wells. It is stressed that one of the key advantages relates to the opportunities to optimize the orientation and position of horizontal wells with respect to the principal directions for the reservoir depositional environment, but this may interact with natural fracture or fault directions, and the principal stress direction if hydraulic fracturing is to be considered. Analytical methods for calculating critical coning rates in homogeneous reservoirs are reviewed, and shown to give a very large range of results for horizontal wells. The potential significance of two-phase pressure drop within the wellbore on GOR performance is discussed, and a range of uncertainty by a factor of six is indicated between the use of various correlations for calculating the well pressure drop. In the final section studies are summarized for a gas coning application using ECLIPSE, a commercial simulator. The simulation results indicated an apparently invariant behaviour on GOR history with respect to the effects of wellbore twophase pressure drop when the horizontal well was produced at constant rate in a homogeneous reservoir. However, when the controlling conditions on the horizontal well were made more representative, and reservoir non-uniformity was introduced, it was then found that the two-phase pressure drop became very significant. Some areas for further research are indicated.
Prediction and evaluation of horizontal well performance; North Slope, Alaska
Authors: Sherrard D. W.
Published: November 2010

Seven years of field production data from a horizontal well programme in Alaska are reviewed. Expectations and analyses prior to drilling are compared with extensive efforts to understand well performance once on production. Evaluation of well performance is considered through well testing, production logging and reservoir simulation. The review concludes that accurate reservoir description is critical to successful forecasting; simplistic description can lead to overestimation of productivity. Furthermore, innovative reservoir characterization techniques may be necessary to utilize a complex description properly in predictive mode. Production logging is highlighted as a critical diagnostic tool, despite the need to run on coiled tubing. In contrast, pressure transient analysis, for which theory is well developed, can be problematic and may require modification to traditional field practices.
The use of well seismic profiles and LWD to steer a horizontal well
Authors: Dobb A. , Robertson G. , Reilly J. M. , Purpich A. J.
Published: November 2010

The 9/13a-A53 sub-horizontal well was drilled from the Beryl Alpha platform in order to target bypassed oil reserves and produce low GOR oil. This paper outlines the work of the multi disciplinary team from the planning through to production. The primary producing unit in the Beryl Field is the Middle Jurassic Beryl Formation. In the Central Area of Beryl Alpha, re-injected gas has preferentially moved down structure in the higher permeability upper Beryl Formation sandstones, overriding a substantial volume of oil. Well 9/13a-A53 was designed to target this oil. Innovative data acquisition strategies were employed during the drilling of the well. The approach to the well target necessitated crossing a 150 ft fault and sub-seismic faults/fractures were anticipated within the wellbore. No pilot hole was planned, instead an intermediate look-ahead' well seismic profile (WSP) was run to determine the position of the fault prior to drilling. Real-time logging while drilling (LWD) was incorporated in the drilling assembly to pick stratigraphic markers and react to possible directional drilling changes. This detailed planning resulted in the well being drilled on prognosis. In the well completion, a cemented liner was landed to allow selective perforation, away from potentially gas-conductive fracture zones. A monobore completion was utilized to improve future gas isolation operations and to optimize deliverability. The well came on-line in late 1992 and is currently producing low GOR oil at commercial rates.
Crystalline basement focusing of heat versus fluid flow/compaction effects; a case study of the I-1 well in the Danish North Sea
Authors: Yu Z. , Thomsen R. O. , Lerche I.
Published: November 2010

The temperature distribution in the Danish Central Graben contains many local thermal anomalies, with the thermal gradient varying throughout the area from around 20 degrees Ckm (super -1) to about 55 degrees Ckm (super -1) . The presence of sub-surface salt structures of various shapes and sizes is responsible for many of the anomalies. In the case of the 1-1 well, however, four components can contribute to the observed thermal anomaly. (1) crystalline basement focusing of heat; (2) convection of heat from the deeper basin; (3) a local thermal anomaly due to salt or structure effects; and (4) the possible spatial variation of basement heat flux with position relative to the graben flank. While components (1), (2) and (3) do contribute to the thermal anomaly at the 1-1 well, they are not large enough to account for the anomaly without the presence of a local increase in basement heat flux of around 0.5 HFU (c. 21mWm (super -2) ).
The prediction of high porosity chalks in the East Hod Field
Authors: Campbell Simon J. D. , Gravdal N.
Published: November 2010

The East Hod Field in the Norwegian Block 2/11 produces from the Lower Tertiary and Upper Cretaceous Chalk Group. Although at first sight the trapping mechanism of the East Hod Field appears to be structural, increased understanding of porosity preservation, combined with new seismic interpretation, demonstrates that there is also a strong stratigraphic component. Both autochthonous and allochthonous facies occur, the latter forming the principal reservoirs. The extremely homogeneous nature of the matrix means that variations in seismic response directly reflect changes in pore volume, and a good correlation between seismic impedance and porosity is observed. High quality 3D seismic data made it possible to undertake seismic inversion which, together with the correlation between seismic impedance and porosity, allows prediction of porosity variations within the inter-well volume. The results indicate that within the allochthonous reservoir units, porosity is maintained in down-flank areas at depths previously believed to be predominantly tight. Seismic inversion is particularly accurate for predicting porosity because of the exceptionally uniform nature of the chalk matrix.
Petroleum potential of the North Hungarian Oligocene sediments
Authors: Milota K. , Kovacs A. , Galicz Z.
Published: November 2010

As part of Eoparatethys, a partly isolated sea existed to the north of the present-day Pannonian Basin during Oligocene time. From Lattorfian times thick shale sequences, rich in organic matter, were deposited. Locally, laminates of euxinic facies formed (Tard Clay Formation) and are the best oil-prone source rocks of the Oligocene sequence. Although oil discoveries were made in the basin in the late 1930s, exploration was prevented by the complicated tectonics. Currently, detailed seismic, geological and geochemical studies have been initiated, the first results of which are summarized in this paper. Rock-Eval pyrolysis data and bituminological analysis show the Tard Clay Formation to be a good source rock. Its thermal maturity has been influenced by subsequent tectonic movements and Neogene heat flux. Migration and accumulation of the generated hydrocarbons is controlled by unconformities and, in particular, by the tectonic elements. Complicated structural and stratigraphical traps are covered by the Pliocene basal marl.
Petroleum geology of the Carpathian Foredeep and overthrust zones in the Czech Republic
Authors: Ciprys V. , Adamek J. , Benada S.
Published: November 2010

The area is situated at the contact of two regional megastructures -the Bohemian Massif and the Western Carpathians. The eastern slope of the Bohemian Massif dips under the Carpathian Foredeep and thick Flysch nappes and is covered by Variscan and Neoidic autochthonous Palaeozoic, Mesozoic and Palaeogene sediments. In the southeast, the Vienna basin's Neogene fill overlies the units of the Magura Flysch and a part of the Zdanice unit. The area can be divided into three parts. The south is characterized by a thick Jurassic sedimentary complex that overlies the crystalline basement. The basal elastics of this Jurassic complex are very prospective and in the central part of the area the oil field Uhrice II is situated in these strata. In this central part two deep depressions - the Vranovice and Nesvacilka grabens - are the most important buried geomorphological elements. Both are filled with Palaeogene strata. The north of the area is characterized by uplifted crystalline basement with thin autochthonous sediments, mostly with Miocene strata of the foredeep and with the flysh nappes. Thick Palaeogene and Upper Jurassic pelites are supposed to be the main source rocks. The cap rocks are pelitic sequences of variable thicknesses including Jurassic marls, Palaeogene and Miocene claystones and basal claystones of flysch units. Traps are delimited by faults, lithology changes and unconformities.
Scale models of salt tectonics during basement-involved extension
Authors: Vendeville B. C. , Ge Hongxing , Jackson M. P. A.
Published: November 2010

Scaled experiments, whose design was based on recently published low values for the viscosity of natural rocksalt, suggest that under typically low geological extension rates, a salt layer 500 m thick or thicker decouples the brittle overburden from the faulted basement. Because of its low viscosity, salt cannot transmit the large differential stresses necessary for basement faults to propagate upward as faults or abrupt forced folds into the brittle overburden, unless the salt layer is thin or has been depleted. Thick salt diffuses localized deformation in the basement by flowing away from rising basement blocks, and toward sinking basement blocks. Basement extension is not transmitted to the overburden vertically but is laterally transmitted from the margins as the salt basin widens. Rather than being controlled by basement faults, the distribution of faults and diapirs in the overburden is controlled by lateral changes in overburden stratigraphy or thickness, preexisting faults, and faults that propagate laterally into the salt basin.
A continuum approach to the petrophysical classification and evaluation of reservoir rocks
Authors: Worthington Paul F.
Published: November 2010

The electrical behaviour of fully electrolyte-saturated reservoir rock samples has been represented through verified type curves as a continuum across a range of electrolyte resistivity. The type curves can be used to facilitate the well-log interpretation of clastic reservoirs for which the Archie porosity exponent is known or can be realistically assumed. They allow an immediate appreciation of the electrical characteristics of reservoir rocks and how these relate to other, previously studied formations. The type curves can be used with core or log data to infer whether a reservoir is behaving as effectively clean or shaly. In the case of effectively shaly sands, a single-point value of excess conductivity can be evaluated from log data alone. More generally, the type curves allow different reservoirs to be compared in terms of their electrical behaviours. Where these are similar, it is reasonable to assume that the petrophysical interpretation procedures will be similar for the reservoirs under consideration. Thus, the type curves allow a given reservoir to be characterized and evaluated within a generic framework of electrical behaviour. This, in turn, allows experience gained elsewhere to be brought to bear on the current appraisal, especially in terms of the identification of appropriate procedures for the well-log evaluation of hydrocarbons-in-place. Through this insight, the method constitutes a potential basis for greater confidence in petrophysically-supported reservoir models at an earlier stage in the evaluation of a field.
Subtle traps in extensional terranes; a model with reference to the North Sea
Authors: Gabrielsen Roy H. , Steel Ron J. , Nottvedt Arvid
Published: November 2010

The three stages of graben formation (initial, active stretching and thermal subsidence/sedimentary loading) offer different subsidence patterns, and, hence, different patterns of topography and deposition. The pre-rift stage (in rifts without pre-rift doming) is characterized by development of a broad basin with well developed axial and secondary transverse sediment transport. Stratigraphic traps are uniform and display less variation than in the subsequent stages. During the active stretching stage the basin geometry becomes more varied. Rotational fault blocks parallel to the graben margin become activated, and active fault scarps contribute to the instability of the system and to sedimentary transport systems parallel to the graben axis. The active stretching stage generates a topographically complex depositional environment, and potentially offers a great variety of subtle traps. The thermal subsidence/sedimentary loading stage brings the basin back to a less complicated geometry, and several types of unconformity traps will characterize the transition from the active stretching to the cooling stage. The dominant sediment transport system is transverse to the rift axis. The variety in types of subtle traps again is lowered.