bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of UV irradiation on tribological properties of nano‐TiO2 thin films
Authors: Wang Yunxia , Wang Hongling , Yan Fengyuan 
Published: March 2009

AbstractOne‐layer and two‐layer nano‐TiO2 thin films were prepared on the surface of common glass by sol–gel processing. Water contact angle, surface morphology, tribological properties of the films before and after ultraviolet (UV) irradiation were investigated using DSA100 drop shape analyzer, scanning probe microscopy (SPM), SEM and universal micro‐materials tester (second generation) (UMT‐2MT) friction and wear tester, respectively. The stored films markedly resumed their hydrophilicity after UV irradiation. But UV irradiation worsened tribological properties of the films. After the film was irradiated by UV, the friction coefficient between the film and GCr15 steel ball increased about 10–50% and its wear life shortened about 20–90%. Abrasive wear, brittle break and adherence wear are the failure mechanisms of nano‐TiO2 thin films. It was believed that UV irradiation increased surface energy of the film and then aggravated adherence wear of the film at initial stage of friction process leading to severe brittle fracture and abrasive wear. Copyright © 2009 John Wiley & Sons, Ltd.
Preparation of Monodisperse Biodegradable Polymer Microparticles Using a Microfluidic Flow‐Focusing Device for Controlled Drug Delivery
Authors: Xu Qiaobing , Hashimoto Michinao , Dang Tram T. , Hoare Todd , Kohane Daniel S. , Whitesides George M. , Langer Robert , Anderson Daniel G. 
Published: March 2009

AbstractDegradable microparticles have broad utility as vehicles for drug delivery and form the basis of several therapies approved by the US Food and Drug Administration. Conventional emulsion‐based methods of manufacturing produce particles with a wide range of diameters (and thus kinetics of release) in each batch. This paper describes the fabrication of monodisperse, drug‐loaded microparticles from biodegradable polymers using the microfluidic flow‐focusing (FF) devices and the drug‐delivery properties of those particles. Particles are engineered with defined sizes, ranging from 10 µm to 50 µm. These particles are nearly monodisperse (polydispersity index = 3.9%). A model amphiphilic drug (bupivacaine) is incorporated within the biodegradable matrix of the particles. Kinetic analysis shows that the release of the drug from these monodisperse particles is slower than that from conventional methods of the same average size but a broader distribution of sizes and, most importantly, exhibit a significantly lower initial burst than that observed with conventional particles. The difference in the initial kinetics of drug release is attributed to the uniform distribution of the drug inside the particles generated using the microfluidic methods. These results demonstrate the utility of microfluidic FF for the generation of homogenous systems of particles for the delivery of drugs.
Two organizational case studies of IT‐Enabled value
Authors: Kanungo Shivraj 
Published: March 2009

AbstractIT‐enabled value has continued to attract research and managerial attention because some organizations tend to outperform others in deriving IT‐enabled value from their investments. Since there are many direct and indirect influencers of IT‐enabled value, we posit that what may distinguish one organization from another are the assumptions and conceptual models of transformation processes associated with IT‐enabled value creation. Transforming organizational inputs like technology investments, investments in improvement and training and management resources into IT‐enabled value is a complex process. Consequently, we adopted a process‐oriented stance to uncover the mental models and shared assumptions that underlie such transformative processes. By using interpretive structural modelling, we were able to map and analyse conceptual models of principal stakeholders who are associated with information technologies in two organizations. Our results show how antecedents and consequents associated with IT‐enabled value vary across organizations. The primary implication of our findings for managers and practitioners is that it is possible to identify the principal levers to derive IT‐enabled value. The major research implication lies in being able to frame the process of deriving IT‐enabled value as emergent and dynamic. Our methodological contribution is in presenting an efficient approach to understand and improve the process of IT‐enabled value creation. This forms an important contribution because post‐facto insights may be too late for organizations and managers to leverage the potential of new technologies. Copyright © 2009 John Wiley & Sons, Ltd.
Increasing lifetime of wireless sensor networks using controllable mobile cluster heads
Authors: Banerjee Torsha , Xie Bin , Jun Jung Hyun , Agrawal Dharma P. 
Published: March 2009

AbstractIn a static wireless sensor network (WSN), sensors close to the base station (BS) run out of energy at a much faster rate than sensors in other parts of the network. This is because the sensor close to the BS always relays the data for other sensors, resulting in an unequal distribution of network residual energy. In this paper, we propose a scheme for enhancing the network lifetime using multiple mobile cluster heads (CHs) that can move in the WSN in a controllable manner. The CH controllably moves toward the energy‐rich sensors or the event area, offering the benefits of maintaining the remaining energy more evenly, or eliminating multihop transmission. Therefore, the proposed scheme increases the network lifetime. We theoretically analyze the energy consumption in our scheme and propose three heuristical mobility strategies. We further study the collaboration among CHs in order to maintain their connectivity to the BS to ensure the delay requirement for real‐time applications. Simulation shows that network lifetime is increased by upto 75% over existing approach by making CHs always move toward a stable equilibrium point. Our connectivity algorithm provides a best case improvement of 40% in transmission delays over existing schemes. Copyright © 2009 John Wiley & Sons, Ltd.
Crystal Structure Refinement and Electronic Properties of Si(cI16)
Authors: Wosylus Aron , Rosner Helge , Schnelle Walter , Schwarz Ulrich 
Published: March 2009

AbstractSi(cI16) is prepared in polycrystalline form at 12(1.5) GPa at temperatures between 800(80) K and 1200(120) K. The crystal structure is refined by a full‐profile method using x‐ray powder diffraction data. Si(cI16) is diamagnetic (χ0 = –5.6(1.8) × 10–6 emu·mol–1) and shows a weakly temperature‐dependent electrical resistivity [ρ(300 K) = 0.3 × 10–3 Ω·m]. Computations of structural and electronic properties of Si(cI16) within the local density approximation evidence the metastable character of the allotrope with respect to diamond‐type silicon. The calculations yield a positional parameter which is in perfect agreement with the refined value. In agreement with the experimentally observed electrical conductivity properties, the computed density of states evidence that the Fermi level of Si(cI16) is located in a pseudo‐gap.
Bi-Functional Silica Nanoparticles Doped with Iron Oxide and CdTe Prepared by a Facile Method
Authors: Ren Cuiling , Sun Jiefang , Li Jinhua , Chen Xingguo , Hu Zhide , Xue Desheng 
Published: March 2009

Abstract
Cadmium telluride (CdTe) and iron oxide nanoparticles doped silica nanospheres were prepared by a multistep method. Iron oxide nanoparticles were first coated with silica and then modified with amino group. Thereafter, CdTe nanoparticles were assembled on the particle surfaces by their strong interaction with amino group. Finally, an outer silica shell was deposited. The final products were characterized by X-ray powder diffraction, transmission electron microscopy, vibration sample magnetometer, photoluminescence spectra, Fourier transform infrared spectra (FT-IR), and fluorescent microscopy. The characterization results showed that the final nanomaterial possessed a saturation magnetization of about 5.8 emu g−1and an emission peak at 588 nm when the excitation wavelength fixed at 380 nm.
Fine‐needle aspiration biopsies in the management of indeterminate follicular and Hurthle cell thyroid lesions
Authors: Mijović Tamara , Rochon Louise , Gologan Olguta , Hier Michael P. , Black Martin J. , Young Jonathan , Payne Richard J. 
Published: March 2009

ObjectivesTo determine the value of fine‐needle aspiration biopsies (FNABs) of the thyroid and stratify the risk of malignancy within the indeterminate FNAB diagnostic category at our institution.Study designCase series with chart review of preoperative FNABs of consecutive patients who underwent total thyroidectomy between 2005 and 2007.Subjects and MethodsA total of 115 cases were reviewed, and FNABs were categorized into four groups: benign, positive or suspicious for malignancy, indeterminate (follicular or Hurthle cell lesions), and nondiagnostic. Cytohistologic correlation was then established.ResultsThe accuracy of FNAB in detecting thyroid malignancy was 88 percent with false‐negative and false‐positive rates of 13 percent and 7 percent, respectively. Overall, 52 percent of the indeterminate cases were carcinomas (48 percent of follicular lesions and 62 percent of Hurthle cell lesions). In the presence of cytologic atypia, the rate of malignancy increased to 75 percent and 83 percent for the follicular and Hurthle cell lesions, respectively.ConclusionsFNAB is an accurate and helpful method for the evaluation of thyroid nodules with results directly correlating with management. Surgery should be considered for FNABs categorized as indeterminate, especially in the presence of cytologic atypia. Because of the high false‐negative rate, benign FNABs require close follow‐up with ultrasound examination and periodic biopsies.
A POLYNOMIAL RING CONSTRUCTION FOR THE CLASSIFICATION OF DATA
Authors: KELAREV A. V. , YEARWOOD J. L. , VAMPLEW P. W. 
Published: March 2009

AbstractDrensky and Lakatos (Lecture Notes in Computer Science, 357 (Springer, Berlin, 1989), pp. 181–188) have established a convenient property of certain ideals in polynomial quotient rings, which can now be used to determine error-correcting capabilities of combined multiple classifiers following a standard approach explained in the well-known monograph by Witten and Frank (Data Mining: Practical Machine Learning Tools and Techniques (Elsevier, Amsterdam, 2005)). We strengthen and generalise the result of Drensky and Lakatos by demonstrating that the corresponding nice property remains valid in a much larger variety of constructions and applies to more general types of ideals. Examples show that our theorems do not extend to larger classes of ring constructions and cannot be simplified or generalised.
A KADISON–SAKAI-TYPE THEOREM
Authors: MIRZAVAZIRI MADJID , MOSLEHIAN MOHAMMAD SAL 
Published: March 2009

AbstractSuppose thatσ:𝔐→𝔐 is an ultraweakly continuous surjective *-linear mapping andd:𝔐→𝔐 is an ultraweakly continuous *-σ-derivation such thatd(I) is a central element of 𝔐. We provide a Kadison–Sakai-type theorem by proving that ℌ can be decomposed into${\mathfrak K}\oplus {\mathfrak L}$anddcan be factored as the form$\delta \oplus 2Z\tau $, whereδ:𝔐→𝔐 is an inner *-σ𝔎-derivation,Zis a central element, 2τ=2σ𝔏is a *-homomorphism, andσ𝔎andσ𝔏stand for compressions ofσto 𝔎 and 𝔏 , respectively.
EMBEDDING GROUPS OF CLASS TWO AND PRIME EXPONENT IN CAPABLE AND NONCAPABLE GROUPS
Authors: MAGIDIN ARTURO 
Published: March 2009

AbstractWe show that ifGis anyp-group of class at most two and exponentp, then there exist groupsG1andG2of class two and exponentpthat containG, neither of which can be expressed as a central product, and withG1capable andG2not capable. We provide upper bounds for rank(Giab) in terms of rank(Gab) in each case.
ON MOROZOV’S DISCREPANCY PRINCIPLE FOR NONLINEAR ILL-POSED EQUATIONS
Authors: NAIR M. T. 
Published: March 2009

AbstractMorozov’s discrepancy principle is one of the simplest and most widely used parameter choice strategies in the context of regularization of ill-posed operator equations. Although many authors have considered this principle under general source conditions for linear ill-posed problems, such study for nonlinear problems is restricted to only a few papers. The aim of this paper is to apply Morozov’s discrepancy principle for Tikhonov regularization of nonlinear ill-posed problems under general source conditions.
Naphthoimidazoles promote different death phenotypes in Trypanosoma cruzi
Authors: MENNA-BARRETO R. F. S. , CORRÊA J. R. , CASCABULHO C. M. , FERNANDES M. C. , PINTO A. V. , SOARES M. J. , DE CASTRO S. L. 
Published: March 2009

SUMMARYIn a screening of 65 derivatives of natural quinones using bloodstream trypomastigotes of Trypanosoma cruzi, the 3 naphthoimidazoles derived from β-lapachone – N1, N2 and N3 – were selected as the most active. Investigation of their mode of action led to the characterization of mitochondrion, reservosomes and DNA as their main targets, and stimulated further studies on death pathways. Ultrastructural analysis revealed both autophagic (autophagosomes) and apoptotic-like (membrane blebbing) phenotypes. Flow cytometry analysis showed, in N2-treated trypomastigotes, a small increase of phosphatidylserine exposure, and a large increase in the percentage of necrosis, caused by N1 or N2. These death phenotypes were not detected in treated epimastigotes. The strong increase in labelling of monodansyl cadaverine, the inhibition of the death process by wortmannin or 3-methyladenine, the overexpression of ATG genes in treated epimastigotes, together with ultrastructural evidence point to autophagy as the predominant phenotype induced by the naphthoimidazoles. However, there are other pathways occurring concomitantly with variable intensities, justifying the need to detail the molecular features involved.
Observation of quasi mono-energetic electron bunches in the new ellipsoid cavity model
Authors: Sadighi-Bonabi R. , Navid H.A. , Zobdeh P. 
Published: March 2009

AbstractIn this work, we introduce a new ellipsoid model to describe bubble acceleration of electrons and discuss the required conditions of forming it. We have found that the electron trajectory is strongly related to background electron energy and cavity potential ratio. In the ellipsoid cavity regime, the quality of the electron beam is improved in contrast to other methods, such as that using periodic plasma wakefield, spherical cavity regime, and plasma channel guided acceleration. The trajectory of the electron motion can be described as hyperbola, parabola, or ellipsoid path. It is influenced by the position and energy of the electrons and the electrostatic potential of the cavity. In the experimental part of this work, a 20 TW power and 30 fs laser pulse was focused on a pulsed He gas jet. We have focused the laser pulse in the best matched point above the nozzle gas to obtain a stable ellipsoid bubble. The finding of the optimum points will be described in analytical details.
Twelve-month-olds learn novel word–object pairings differing only in stress pattern
Authors: CURTIN SUZANNE 
Published: March 2009

ABSTRACTInfants at 1 ; 2 demonstrate difficulty in accessing subtle phonetic information about newly learned word–object pairings (Stager & Werker, 1997). In this study, we examined whether or not infants can access subtle prosodic information such as lexical stress in a word learning task. We tested infants younger than 1 ; 2 to see if they could learn two new word–object associations that differ only in stress pattern (Sww versus wSw). Our results are the first to demonstrate that, even without contextual support, infants at 1 ; 0 succeed at this task, suggesting that the salient acoustic properties associated with lexical stress facilitate word–object associative learning.
Bengali raw silk, the East India Company and the European global market, 1770–1833
Authors: Davini Roberto 
Published: March 2009

AbstractIn 1769, the East India Company decided to transform the Bengali silk industry, and introduced Piedmontese reeling technologies and spatially concentrated working practices into the area. Although Bengali raw silk reeled with the new methods never reached the standards of Piedmontese silks, the Company was able to produce huge quantities of low-quality raw silks, and to gain market share in London from the 1770s to the 1830s. By investigating the reasons behind this partial success, this article shows that some features of Piedmontese technologies had a crucial impact on peasants who specialized in the mulberry cultivation and the rearing of silkworms. The Company had to cope with resistance from some rural economic agents in late eighteenth- and early nineteenth-century Bengal, but other elements in local society were able to profit from the Company's interest in producing raw silk.
‘Paying for the Emergency by displacing the settlers’: global coffee and rural restructuring in late colonial Kenya
Authors: Hyde David 
Published: March 2009

AbstractGlobal coffee markets entered into a deep cyclical downturn from the mid 1950s. As producers, notably Brazil and Colombia, continued to increase their output, intense struggles arose among global competitors for larger slices of a contracting market. The prospect of an economic catastrophe, following the release of Brazil's surplus stocks, preoccupied Kenya's colonial government, which was dependent on tax revenues derived from coffee sales, and was less able to support the settler-dominated industry in the face of the increased costs incurred by the Mau Mau Emergency after 1952. This left European settlers exposed, with many barely able to recover their costs of production. What began as a counter-insurgency strategy, by allowing an elite of African farmers to grow Arabica coffee (a privilege formerly reserved to settlers) was enlarged and accelerated in response to unrelenting global market pressures. These compelled the colonial government to beckon low-cost African farmers into coffee production, in a bid to save its tax base and ensure the survival of the coffee sector. Even though the Coffee Marketing Board confiscated much of their income, African farmers proved well able to rally family labour and achieve surpluses. Rationalization of production and the re-organization of the commodity chain to maintain high quality at lower cost were decisive in both reconfiguring the economic and social relationships that underpinned Kenya's independence in 1963 and securing the country's place on the world market. The aim here is to explain the crisis, and its grip on Kenya's economy during the transition to independence and beyond.
Discovery of an extended, halo-like stellar population around the Large Magellanic Cloud
Authors: Majewski Steven R. , Nidever David L. , Muñoz Ricardo R. , Patterson Richard J. , Kunkel William E. , Carlin Jeffrey L. 
Published: March 2009

AbstractWe describe an ongoing, large-scale, photometric and spectroscopic survey of the Large Magellanic Cloud (LMC) periphery. This survey uses WashingtonM,T2+DDO51 photometry to identify distant LMC red giant branch (RGB) star candidates; multi-object spectroscopy is used to confirm the stellar surface gravities of these RGB stars and their association with the LMC (e.g., through radial velocities). The survey now encompasses hundreds of fields ranging from the LMC center with full azimuthal coverage around the LMC and out to 23° from the LMC center. We have confirmed the existence of RGB stars with (the unusual) Magellanic velocities out to the radial limit of this survey coverage. From data in a subsample of these fields, we show that this extended population of stars makes up a diffuse structure enveloping the LMC with a two-dimensional distribution resembling a classical halo with a shallow de Vaucouleurs profile and a broad metallicity spread around a typical mean value of [Fe/H] ~ −1.0.
Modeling a high velocity LMC: The formation of the Magellanic Stream
Authors: Mastropietro Chiara 
Published: March 2009

AbstractI use high resolution N-body/SPH simulations to model the new proper motion of the Large Magellanic Cloud (LMC) within the Milky Way (MW) halo and investigate the effects of gravitational and hydrodynamical forces on the formation of the Magellanic Stream (MS). Both the LMC and the MW are fully self consistent galaxy models embedded in extended cuspy ΛCDM dark matter halos. I find that ram-pressure from a low density ionized halo is sufficient to remove a large amount of gas from the LMC's disk forming a trailing Stream that extends more than 120 degrees from the Cloud. Tidal forces elongate the satellite's disk but do not affect its vertical structure. No stars become unbound showing that tidal stripping is almost effectless.
The star formation process in the Magellanic Clouds
Authors: Oliveira J. M. 
Published: March 2009

AbstractThe Magellanic Clouds offer unique opportunities to study star formation both on the global scales of an interacting system of gas-rich galaxies, as well as on the scales of individual star-forming clouds. The interstellar media of the Small and Large Magellanic Clouds and their connecting bridge, span a range in (low) metallicities and gas density. This allows us to study star formation near the critical density and gain an understanding of how tidal dwarfs might form; the low metallicity of the SMC in particular is typical of galaxies during the early phases of their assembly, and studies of star formation in the SMC provide a stepping stone to understand star formation at high redshift where these processes can not be directly observed. In this review, I introduce the different environments encountered in the Magellanic System and compare these with the Schmidt-Kennicutt law and the predicted efficiencies of various chemo-physical processes. I then concentrate on three aspects that are of particular importance: the chemistry of the embedded stages of star formation, the Initial Mass Function, and feedback effects from massive stars and its ability to trigger further star formation.
Integrated spectral properties of star clusters in the Magellanic Clouds
Authors: Ahumada Andrea V. , Talavera M. L. , Clariá J. J. , Santos J. F. C. , Bica E. , Parisi M. C. , Torres M. C. 
Published: March 2009

AbstractWe present flux-calibrated integrated spectra in the optical spectral range of concentrated star clusters in the Large and Small Magellanic Clouds (LMC-SMC), approximately half of which constitute unstudied objects. We have mainly estimated ages and foreground interstellar reddening values from the comparison of the line strengths and continuum distribution of the cluster spectra with those of template spectra with known parameters. Also reddening values were estimated by interpolation between the extinction maps of Burstein & Heiles (1982) (BH). A good agreement between ages and reddenings derived through the different procedures was found. The ages of the 27 LMC star clusters range from 5 to 125 Myr, while those of the 13 SMC vary from 4 to 350 Myr.
Nonlinear modeling of InP devices for W-band applications
Authors: Resca Davide , Di Giacomo Valeria , Raffo Antonio , Cignani Rafael , Santarelli Alberto , Vannini Giorgio , Filicori Fabio , Schreurs Dominique , Medjdoub Farid , Thouvenin Nicolas , Gaquière Christophe 
Published: March 2009

A recently proposed technique for the distributed modeling of extrinsic parasitic effects in electron devices is used for the very first time in conjunction with a lumped equivalent circuit model for the intrinsic device.Nonlinear modeling of 0.1 μm InP HEMTs for W-band applications is considered here, leading to extremely accurate predictions of harmonic distortion and power added efficiency at the fundamental frequencies of 27 and 94 GHz.The distributed parasitic network is identified through accurate electromagnetic simulations up to the upper frequency limit of the millimeter-wave band (300 GHz), while standard pulsedI/VandS-parameter measurements up to 67 GHz are used for the identification of the intrinsic device model.