bluuebunny/crossref_metadata_2025_split huggingface dataset:
Photorefractive effect of ferroelectric liquid crystals
Authors: Sasaki Takeo 
Published: February 2006

AbstractThis paper reviews our recent work on the photorefractive effect of ferroelectric liquid crystals (FLCs). Thephotorefractive effectis defined as the optical modulation of the refractive index of a medium as a result of a variety of processes. The interference of two laser beams in a photorefractive material establishes a refractive index grating. This phenomenon enables the creation of different types of photonic applications. FLCs exhibit fast electric field response, and the orientation of the molecular axis of FLCs changes its direction according to the change in direction of the spontaneous polarization (Ps). When two laser beams interfere in a photoconductive FLC, an orientational grating is formed. The mechanism of the formation of the grating is based on the response of the Ps to the photoinduced internal electric field. The time of formation of the refractive index grating is significantly shorter in FLC materials. © 2006 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 6: 43–51; 2006: Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/tcr.20071
Knowledge diffusion in the African context: An institutional theory perspective
Authors: Kamoche Ken , Harvey Michael 
Published: February 2006

AbstractMultinational companies have been increasing their investments in Africa as they become aware of the high returns available there. These investments often require relations with African partners and rely on knowledge transfer for their success. For these relations to be successful, we argue that multinationals must eschew the knowledge‐transfer approaches that reflect the ethnocentric assumption that codifiable knowledge can be disseminated with little regard to the unique circumstances of the African context, and by disregarding culturally embedded tacit knowledge. This article offers the conceptual lens of institutional theory as a way to improve the processes of knowledge diffusion and learning. We show how this theory can lead to a better understanding of the process of knowledge diffusion within the African context by requiring foreign investors and expatriates to improve their understanding of the African business environment. We then assess the role of boundary spanners in the diffusion process and identify some circumstances that might impinge on knowledge diffusion. © 2006 Wiley Periodicals, Inc.
Bracing for MNC competition through innovative HRM practices: The way ahead for Indian firms
Authors: Som Ashok 
Published: February 2006

AbstractWith increasing globalization, firms are entering a dynamic world of international business that is marked by liberalization of economic policies in a large number of emerging economies like India. To face the challenge of increasing competition that has resulted from liberalization, Indian organizations have initiated adoption of innovative human resource management practices both critically and constructively to foster creativity and innovation among employees. With the help of 11 in‐depth case studies, this article tries to understand how innovative HRM practices are being adopted by Indian firms to brace for competition in the postliberalization scenario. © 2006 Wiley Periodicals, Inc.
Fitting strategy derived from strategic orientation to international contexts
Authors: Griffith David A. , Jacobs Laurence , Richey R. Glenn 
Published: February 2006

AbstractThe search for strategic fit within a market has become a core concept in strategy research. The issue of strategic fit is becoming increasingly important in international strategy as managers and academics explore the uniqueness of international markets. Unfortunately, during a time of open market diversity, many firms are driving toward a singular strategic orientation (i.e., market orientation), thus ignoring the underlying problems and criticisms with a standardized strategy, often resulting in suboptimal performance. A model highlighting the criteria necessary for fitting strategy to international contexts is developed. An empirical illustration is then used to examine the benefits of strategically fitting strategy to context. Finally, a process is provided to assist managers in the formation and implementation of their strategy. © 2006 Wiley Periodicals, Inc.
Formal Aspects of Correctness and Optimality of Interval Computations
Authors: Santiago Regivan H. Nunes , Bedregal Benjamín R. Callejas , Acióly Benedito Melo 
Published: February 2006

Abstract

An interval is a continuum of real numbers, defined by its end-points. Interval analysis, proposed by R. Moore in the 50's, concerns the discovery of interval functions to produce bounds on the accuracy of numerical results that are guaranteed to be sharp and correct. The last criterion,
correctness
, is the main one since it establishes that the result of an interval computation must always contains the value of the related real function.

Correctness rests on the ``Fundamental Theorem of Interval Arithmetic''. This theorem, induced us to define
interval representations
, which captures the fact that interval analysis works like a kind of language to express computations with real numbers, this is implicitly formulated at [HJE01] p. 1045, lemma 2.

Until now the idea of intervals as representation of real numbers was not explicitly defined and its relation with some aspects of interval analysis was not explored. Here we show some of these relations in terms of the topological aspects of intervals (Scott and Moore topologies). The paper also defines what we call
the canonical interval representation
of a real function, which is the obvious best ``mathematical'' (not necessarily computable) interval representation of a real function [inline-graphic not available: see fulltext]. The idea is to show some properties of correct interval algorithms giving a relationship with some other kind of functions, such as extensions and inclusion monotonic functions; and to show how this ideal object preserves the continuity of real functions into Scott and Moore topologies.
Training in Laparoscopic Appendectomy
Authors: Sweeney Karl J. , Dillon Mary , Johnston Sean M. , Keane Frank B. , Conlon Kevin C. 
Published: February 2006

AbstractBackgroundThe role of laparoscopic appendectomy (LA) in surgical training is unclear. Although LA as a therapeutic modality is potentially superior to open surgery, it has failed to become established as standard in training hospitals. The aim of the present study was to evaluate the outcome of LA performed by inexperienced surgeons in a training environment.Materials and MethodsA retrospective analysis of all attempted LA performed over a 12‐month period was undertaken. Data collected included operator grade (experienced and inexperienced), conversion rate and duration of surgery, complications, and postoperative stay.ResultsDuring the study period, 169 appendectomies were performed. The conversion rate to open surgery declined significantly from 28% in the first quarter to 9% in the last quarter, with no difference in the conversion rate between experienced and inexperienced surgeons. Operative time shortened significantly in the inexperienced group. Postoperative complications occurred in 8% of patients, independent of operative grade.ConclusionsOur findings demonstrate that LA may be safely introduced as a teaching procedure. Time‐to‐train should not preclude institutions from adopting the laparoscopic approach in the treatment of acute appendicitis.
Factors Associated with Disease Survival after Surgical Resection in Chinese Patients with Hepatocellular Carcinoma
Authors: Qiang Li , Huikai Li , Butt Kelly , Wang P. Peter , Hao Xishan 
Published: February 2006

AbstractObjectiveThe aim of this cohort study was to investigate clinical outcome and prognostic factors after surgical resection for hepatocellular carcinoma (HCC).Materials and MethodsA total of 1,157 HCC patients undergoing hepatic resection between 1998 and 2003 were included in this study. Univariate and multivariate analyses were performed to examine factors affecting clinical outcome and recurrence.ResultsSurgical procedures consisted of 1,011 (87.4%) anatomical resections, including 205 (17.7%) extended hepatectomies, 324 (28.0%) hemihepatectomies, 482 (41.7%) segmental resections, and 146 (12.6%) local resections. The results suggest that 56.6% of patients had a recurrence of HCC during the study period and the main recurrence type was intrahepatic (542; 83.1%). The median survival time was 45 months. The 1‐, 3‐ and 5‐year overall disease‐free survival rates for the study population were 74%, 47%, and 39% respectively.ConclusionsThe results of proportional hazard analyses suggest that tumor size, number of nodules and vascular invasion were significant predictors for poor survival rates.
The distribution of the Rocky Mountain tailed frog (Ascaphus montanus) in relation to the fluvial system: implications for management and conservation
Authors: Dupuis Linda , Friele Pierre 
Published: February 2006

AbstractThe mating, egg‐laying, and larval development of tailed frogs occur in dynamic mountain streams. During the lengthy (up to 5 years) aquatic residency these species are vulnerable to channel disturbances that can be exacerbated by land uses. Researchers have highlighted specific tailed frog habitat associations but never in the context of fluvial system processes. Based on an extensive regional study with a watershed‐wide sampling strategy, we demonstrate that the Rocky Mountain tailed frog (Ascaphus montanus) is limited to contributing basins of roughly 0.3–100 km2 in size, with peak numbers in basins up to 35 km2. We conclude that the primary determinant of tailed frog distribution patterns in a watershed is basin area, a proximate variable for channel process domain and regional stream discharge: tailed frogs are adapted to cascade and step‐pool channel morphologies that characterize these small basins, presumably because they afford more bedform stability and pore‐space refugia than do smaller, colluvial headwaters, or larger, floodplain‐forming plane bed and pool‐riffle bedforms of mainstem rivers. Secondarily, climate and physiography interact to influence occurrence and abundance at the watershed level by controlling such variables as runoff, water temperature, and sedimentation regime. This point has important management implications because it forces us to recognize that in complex ecosystems, wildlife habitat associations are contingent on site‐specific interactions amongst fluvial system control variables: significance levels of any one variable to tailed frog distribution will not necessarily be consistent among basins. The study clearly shows that case studies can produce conflicting results when they lack a process‐based understanding of ecological response.
Divergence of geometrical optics series at the boundary of its applicability: An analytical example in elementary functions (2D Gaussian beam in free space)
Authors: Kravtsov Yury , Buske Stefan 
Published: February 2006

Abstract
An analytical example in elementary functions is presented (2D Gaussian beam diffraction in free space), which demonstrates the divergence of the geometrical optics (GO) series when the conditions for its applicability are violated. This example shows that accounting for higher terms in GO power series leads to divergence and therefore becomes completely useless beyond the boundaries of GO applicability.
Coulomb blockade in molecular quantum dots
Authors: Walczak Kamil 
Published: February 2006

Abstract
The rate-equation approach is used to describe sequential tunneling through a molecular junction in the Coulomb blockade regime. Such device is composed of molecular quantum dot (with discrete energy levels) coupled with two metallic electrodes via potential barriers. Based on this model, we calculate nonlinear transport characteristics (conductance-voltage and current-voltage dependences) and compare them with the results obtained within a self-consistent field approach. It is shown that the shape of transport characteristics is determined by the combined effect of the electronic structure of molecular quantum dots and by the Coulomb blockade. In particular, the following phenomena are discussed in detail: the suppression of the current at higher voltages, the charging-induced rectification effect, the charging-generated changes of conductance gap and the temperature-induced as well as broadening-generated smoothing of current steps.
Influence of iodine on the electrical properties of magnesium phthalocyanines thin film devices
Authors: Varghese Abraham , Menon C. 
Published: February 2006

Abstract
The influence of iodine on the electrical properties of sandwich structures of magnesium phthalocyanine (Mg Pc) thin films with gold and aluminium electrodes has been investigated. The various electrical properties and different electrical parameters of the iodine-doped Mg Pc thin film devices have been estimated and compared with the values of normal Mg Pc devices from the analysis of the current-voltage characteristics. Generally samples showed an asymmetric conductivity both under forward and reverse bias. From our study we found that iodine doped Mg Pc films showed an enhanced electrical conductivity of nearly ten times that of typical Mg Pc. At low voltages the films showed an ohmic conduction with a hole concentration of P0 = 6.34 × 1018 m−3 and hole mobility μ = 9.16 × 10−5 m 2 V−1 s−1, whereas at higher voltage levels the conduction is dominated by space charged limited conduction (SCLC) with a discrete trapping level of 1.33 × 1022 m−3 at 0.63 eV above the valance band edge. The ratio of the free charges to trapped charges (trapping factor) for the doped samples was found to be 1.07 × 10−7. Furthermore the reverse conduction mechanisms have also been investigated. From the current limitations in the reverse condition a strong rectifying behaviour was evident which was attributed to Poole-Frankel emission with a field-lowering coefficient of value 2.24 × 10−5 eV m1/2 V−1/2.
Spin-dependent transport through magnetic nanojunctions
Authors: Walczak Kamil , Platero Gloria 
Published: February 2006

Abstract
Coherent electronic transport through a molecular device is studied using non-equilibrium Green's function (NEGF) formalism. Such device is made of atomic nanowire which is connected to ferromagnetic electrodes. The molecule itself is described with the help of Hubbard model (Coulomb interactions are treated by means of the Hartree-Fock approximation), while the coupling to the electrodes is modeled through the use of a broad-band theory. It was shown that magnetoresistance varies periodically with increasing length of the atomic wire (in the linear response regime) and oscillates with increasing bias voltage (in the nonlinear response regime). Since the TMR effect for analyzed structures is predicted to be large (tens of percent), these junctions seem to be suitable for application as magnetoresistive elements in future electronic circuits.
Large scale multi-configuration Hartree-Fock calculation of the hyperfine structure of the ground state of vanadium
Authors: Scharf Oliver , Gaigalas Gediminas 
Published: February 2006

Abstract
The hyperfine structure of the ground state of vanadium, 51VI, is calculated in the nonrelativistic framework of the multi-configuration Hartree-Fock approximation. A configuration state function limiting algorithm is used to make the calculations feasible and to study the influence of core, valence and core-valence correlations in detail. The obtained configuration state function space captures the most important orbital correlations within 2%. Further correlations are included through configuration interaction calculation. The atomic state functions are used to evaluate the magnetic dipole hyperfine factor A and the electric quadrupole factor B. It turns out that the ab initio calculation can not capture the core polarization of the 2s shell. It introduces an error that is higher than the Hartree-Fock approximation. However, the detailed correlations being observed suggest the introduction of a wrong correlation orbital due to the algorithm being used. Neglecting this orbital leads to good agreement with 2% deviation from the experimental values for the A factors.
Stock mechanics: Predicting recession in S&P500, DJIA and NASDAQ
Authors: Tuncay Çağlar 
Published: February 2006

Abstract
Proposed in this paper is an original method assuming potential and kinetic energies for prices and for the conservation of their sum that has been developed for forecasting exchanges. Connections with a power law are shown. Semiempirical applications on the S&P500, DJIA, and NASDAQ predict a forthcoming recession in them. An emerging market, the Istanbul Stock Exchange index ISE-100 is found harboring a potential to continue to rise.
Influence of interdiffusion on the electrical conductivity of multilayered metal films
Authors: Dekhtyaruk Leonid 
Published: February 2006

Abstract
The annealing-time dependence of the electrical conductivity of multilayered single-crystal and polycrystalline metal films has been analyzed theoretically within the frame of the semi-classical approach. It is demonstrated that changes in the electrical conductivity which are caused by the diffusion annealing allow for investigating the processes of the bulk and grain-boundary diffusion, and for estimating the coefficients of the diffusion. The electrical conductivity was calculated and the numerical analysis of the diffusion-annealing time dependence was performed at various parameters.
Ac electrical parameters of Al-ZnPc-Al organic semiconducting films
Authors: Kitaneh Rushdi , Saleh Abdelkarim , Gould Robert 
Published: February 2006

Abstract
The ac electrical parameters of thermally evaporated zinc phthalocyanine, ZnPc, semiconducting thin films was measured in the temperature range of 180–390 K and frequency between 0.1 and 20 kHz. Aluminum electrode contacts were utilized to sandwich the organic ZnPc semiconducting films. Capacitance and loss tangent decreased rapidly with frequency at high temperatures, but at lower temperatures a weak variation is observed. An equivalent circuit model assuming ohmic contacts could qualitatively and successfully explains capacitance and loss tangent behavior.
The ac conductivity showed strong dependence on both temperature and frequency depending on the relevant temperature and frequency range under consideration. Ac conductivity σ (ω) is found to vary with ω, as ω
s with the index s ≤ 1.35 suggesting a dominant hopping conduction process at low temperatures (< 250 K) and high frequency. The conductivity of some samples did not increase monotonically with temperature. This behavior was attributed to oxygen exhaustion of the sample as its temperature is increased. The ac conductivity behavior at low temperatures of ZnPc films could be described well by Elliott model assuming hopping of charge carriers between localized sites.
Performance of lead iodide nuclear radiation detectors with the introduction of rare earth elements
Authors: Hassan Mahmoud , Matuchova Marie , Zdansky Karel 
Published: February 2006

Abstract
Lead iodide has been recognized as a promising material for room temperature radiation detectors. It has a wide band-gap (∼ 2.3 eV), high atomic numbers (82, 53) and it is environmentally very stable compared to mercuric iodide. Electrical and optical properties of lead iodide grown crystals purified under the influence of selected rare earth elements have been investigated. Photo-luminescence and capacitance-voltage measurements have been performed using different rare earth elements.
IBM-2 calculations of some even-even selenium nuclei
Authors: Türkan Nurettin , Olgun Davut , Uluer Ýhsan 
Published: February 2006

Abstract
In this study, we determined the most appropriate Hamiltonian that is needed for present calculations of nuclei in the A≅ 80 region by the view of interacting boson model (IBM-2). Using the best-fitted values of parameters in the Hamiltonian, we have calculated energy levels and B(E2) values for a number of transitions in some doubly even Se nuclei. The results were compared with the previous experimental and theoretical data and it is observed that they are in good agreement. The calculations have been extended to Se isotopes with A < 76 for which some B(E2) values are still not known.
Tei index and neurohormonal activation in patients with incident heart failure: Serial changes and prognostic value
Authors: Mikkelsen Kirsten V. , Møller Jacob E. , Bie Peter , Ryde Henrik , Videbæk Lars , Haghfelt Torben 
Published: February 2006

AbstractBackgroundNatriuretic peptides and Tei index are useful indices for risk stratification in advanced left ventricular dysfunction (LVD). Their role in early stages is less clear.AimsIn relation to first diagnosis of LVD to assess the relation of plasma B‐type‐natriuretic peptide (NT‐proBNP) with Tei index, assess serial changes in indices, and to assess the value of indices to predict functional status.MethodsDoppler echocardiography and neurohormonal analysis were performed (n = 150). NYHA class was registered.ResultsTei index correlated with p‐NT‐proBNP (r = 0.75, p < 0.0001), and changes in indices correlated (r = 0.36, p = 0.001) in LVD (n = 80). No functional improvement (n = 47) was related to a median increase in Tei index (−0.2, −0.16; 0.09); an improvement (n = 31) to a reduction (0.06; −0.19; 0.35), p = 0.02. In the group with functional improvement, more patients had ≥ 30% reduction in p‐NT‐proBNP (75% vs. 45%, p < 0.01). Addition of NT‐proBNP or Tei index to a clinical model, of no functional improvement, improved log‐likelihood X2 from 9.32 to 20.18 (p = 0.001) and 20.67 (p = 0.001).ConclusionTei index and p‐NT‐proBNP demonstrated a fair correlation. Unimproved NYHA class was related to progressive LVD and might be identified by monitoring Tei index or p‐NT‐proBNP. Advanced LVD and high pre‐treatment p‐NT‐proBNP levels indicated a potential of improvement in functional status.
The influence of the lunar nodal cycle on Arctic climate
Authors: Yndestad Harald 
Published: February 2006

Abstract
The Arctic Ocean is a substantial energy sink for the northern hemisphere. Fluctuations in its energy budget will have a major influence on the Arctic climate. The paper presents an analysis of the time-series for the polar position, the extent of Arctic ice, sea level at Hammerfest, Kola section sea temperature, Røst winter air temperature, and the NAO winter index as a way to identify a source of dominant cycles. The investigation uses wavelet transformation to identify the period and the phase in these Arctic time-series. System dynamics are identified by studying the phase relationship between the dominant cycles in all time-series. A harmonic spectrum from the 18.6-year lunar nodal cycle in the Arctic time-series has been identified. The cycles in this harmonic spectrum have a stationary period, but not stationary amplitude and phase. A sub-harmonic cycle of about 74 years may introduce a phase reversal of the 18.6-year cycle. The signal-to-noise ratio between the lunar nodal spectrum and other sources changes from 1.6 to 3.2. A lunar nodal cycle in all time-series indicates that there is a forced Arctic oscillating system controlled by the pull of gravity from the moon, a system that influences long-term fluctuations in the extent of Arctic ice. The phase relation between the identified cycles indicates a possible chain of events from lunar nodal gravity cycles, to long-term tides, polar motions, Arctic ice extent, the NAO winter index, weather, and climate.