bluuebunny/crossref_metadata_2025_split huggingface dataset:
Experimental realization of high spin states in dilutely hydrogenated fullerenes
Authors: Makarova T. L. , Zakharova I. B. , Kvyatkovskii O. E. , Buga S. G. , Volkov A. P. , Shelankov A. L. 
Published: October 2009

AbstractA novel method for preparing dilutely hydrogenated fullerenes H:C60 is presented. DFT calculations of the Raman spectra at the B3LYP/3‐21G level are compared with the experimental data. Under the laser treatment these phases form a rich variety of dimeric and polymeric structures, quite in contrast to pristine C60 which forms dimers and polymers bonded through the [2 + 2] addition, and in contrast to heavily hydrogenated fullerenes which do not polymerize at all. Dilutely hydrogenated fullerenes polymerize differently, forming both double bonded structures and single bonded dimers. We have shown that dilute hydrogenation of C60 creates large amount of unpaired spins which disappear due to the formation of diamagnetic single bonded dimers.
Sorting of single‐walled carbon nanotubes by amphiphiles molecules adsorption studied by resonant Raman excitation profile
Authors: Alvarez Laurent , Righi Ariete , Maciel Indhira O. , Pimenta Marcos A. , Michel Thierry , Marquis Renaud , Meunier Stéphane , Sauvajol Jean‐Louis 
Published: October 2009

AbstractAdsorption of specifically designed polyaromatic amphiphiles were used to sort HiPCo single‐walled carbon nanotubes (SWNTs) with different helicities. The sorting is investigated by resonant Raman excitation profiles. Chiral indexes (n and m) of SWNTs present in our samples are determined by fitting the Raman peaks observed in the radial breathing modes region (RBM). Scanning over an excitation energy range between 2 and 2.2 eV with a 0.01 eV step allows to investigate mainly two families of metallic nanotubes (2n + m = 24 and 2n + m = 27). The transition energies of nanotubes measured from the Raman spectra differ from the calculated ones, leading to useful corrections of the Kataura plot. The results also display significant differences between the sorted and the reference samples, meaning that discrimination between SWNTs of different properties is possible.
Shear‐stimulated formation of multi‐wall carbon nanotube networks in polymer melts
Authors: Skipa T. , Lellinger D. , Saphiannikova M. , Alig I. 
Published: October 2009

AbstractWe report on shear‐induced nanotube network formation in multi‐wall nanotubes/polycarbonate (MWNT/PC) composite melts which was directly monitored by the time‐resolved DC‐conductivity measurements during steady shear. A small steady shear applied for 1 h to a non‐conductive composite with initially well‐dispersed nanotubes was found to induce the insulator‐to‐conductor transition resulting in a conductivity increase by about six orders of magnitude. Similar composite melt annealed without steady shear demonstrates much slower process of the network formation what can be attributed to an agglomeration of attractively interacting nanotubes in polymer melts. The rheologic properties were also measured for shear‐stimulated agglomeration. Unexpected difference between the electrical and mechanical networks in MWNT/PC composites was found. For the modeling of the network formation a shear‐dependent kinetic equation for the nanotube agglomeration was coupled with empirical formula for insulator‐to‐conductor transition.magnified imageElectric DC‐conductivity and shear modulus (G′ and G″) of MWNT/PC melt (230 °C) measured simultaneously during shear‐stimulated network formation.
Exciton energy calculations for single wall carbon nanotubes
Authors: Saito R. , Sato K. , Araujo P. T. , Jorio A. , Dresselhaus G. , Dresselhaus M. S. 
Published: October 2009

AbstractUsing the Bethe–Salpeter equation, we have calculated the exciton energies of (i) bright exciton states; (ii) 2g exciton energies; and (iii) the energy difference between dark and bright exciton states for single wall carbon nanotubes (SWNTs) as a function of diameter. By adjusting the dielectric constant, we can reproduce the observed exciton energies in the resonance Raman spectra and two‐photon absorption spectra for SWNTs. The environmental effect on the transition energies can be explained by a diameter‐dependent dielectric constant. However, the energy difference between the dark and bright exciton states cannot be reproduced simply by changing the dielectric constant consistently. Thus we need to consider the evaluation of the Coulomb interaction, especially with regard to the surrounding materials.
Electrophysical properties of multiwalled carbon nanotubes with various diameters
Authors: Romanenko A. I. , Anikeeva O. B. , Buryakov T. I. , Tkachev E. N. , Zhdanov K. R. , Kuznetsov V. L. , Mazov I. N. , Usoltseva A. N. 
Published: October 2009

AbstractWe have investigated temperature σ(T) and magnetic field σ(B) dependences of the conductivity σ of multiwalled carbon nanotubes (MWNTs) with different average outer diameter $\overline d $. From the experimental data we have separated the quantum corrections to σ(T) and σ(B). We have discovered that only quantum corrections for interaction electrons (QCIE) to σ(B) take place. It is associated to the absence of the bulk formations of amorphous carbon in produced MWNTs. From the data of QCIE we have estimated the constant of electron–electron interaction λ which is negative (attraction between electrons) and gradually falling with decrease in MWNTs $\overline d $. Influence of defectiveness and structure of MWNTs on electrophysical properties is discussed.
Diameter dependent Raman scattering of WS2 nanotubes
Authors: Krause Matthias , Virsek Marko , Remškar Maja , Kolitsch Andreas , Möller Wolfhard 
Published: October 2009

AbstractThe effect of the tube diameter and of the surface layer on the Raman spectra of WS2 nanotubes is investigated. With decreasing diameter, a disorder‐induced line in the A1g mode range, the D‐A1g line, is selectively enhanced. This enhancement is attributed to an increasing structural disorder in smaller nanotubes. On the other hand, no significant effect on the D‐A1g/A1g intensity ratio is observed for a Raman scan perpendicular to a 290 nm diameter tube. Therefore the enhancement of the disorder‐induced line is an intrinsic property of WS2 nanostructures and not a surface layer effect.
Self‐oscillations of carbon nanotube twist‐yarn during field emission
Authors: Kleshch V. I. , Zakhidov Al. A. , Obraztsov A. N. , Obraztsova E. D. , Baughman R. H. 
Published: October 2009

AbstractElectromechanical self‐oscillations were induced during field emission from the lateral surface of a twisted nanotube yarn obtained by solid‐state spinning from a forest of vertically aligned multi‐wall carbon nanotubes (CNT). Oscillations at several kilohertz frequencies were driven by applying a constant voltage between fixed opposite ends of the nanotube yarn and a flat anode. An electromechanical model is developed which explains the observed phenomenon. The model is equally applicable to any mechanically flexible field emitter including single nanoemitters like CNTs, which have shown a self‐oscillating behaviour in several previous in situ experiments. This phenomenon opens a possibility of developing a new type of devices for conversion of DC voltage into the high frequency electromagnetic oscillations utilizing flexible nanoemitters.
The quenching of ortho ‐positronium
Authors: Hyodo Toshio , Nakayama Takashi , Saito Haruo , Saito Fuminori , Wada Ken 
Published: October 2009

AbstractOrtho‐positronium (o ‐Ps), which self‐annihilates into 3γ with a lifetime of 142ns, may be quenched through various interactions with atoms and molecules. The quenching process of o ‐Ps in gases, (i) pick‐off quenching, (ii) attachment (chemical) quenching, (iii) spin conversion quenching through electron exchange, (iv) spin conversion quenching through spin‐orbit interaction with a heavy atom, are reviewed. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Positron annihilation studies on bulk cobalt silicides
Authors: Abhaya S. , Amarendra G. 
Published: October 2009

AbstractBulk cobalt silicides Co2Si, CoSi and CoSi2 have been investigated using experimental positron lifetime, coincidence Doppler broadening and depth‐resolved positron beam studies. Psitron lifetime and coincidence Doppler ratio curves have shown distinct features for the silicides as compared to that of pure Co and Si. Ab‐initio calculations of positron life time have been carried out using the DOPPLER program. The experimental positron lifetime values are higher than the theoretical estimates for Co2Si and CoSi2, suggesting that these silicides contain vacancy defects. This is further supported by positron diffusion lengths deduced from the VEPFIT analysis of positron beam results. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Transmission positron microscopes, application of imaging plates to positron, electron and muon research and a proposal for a strong positron source at J‐PARC
Authors: Doyama Masao , Kogure Yoshiaki , Inoue Miyoshi , Kurihara Toshikazu , Miyake Y. , Nishiyama Kusuo , Shimomura Koichiro , Yoshiie Toshisada , Hayashi Yosihiko , Xu Q. , Cao Xingzhong , Matsuya M. , Fujinami M. 
Published: October 2009

AbstractTransmission positron microscope projects in Japan are reviewed. Applications of imaging plates to obtain positron, electron and muon images are discussed and examples are shown. Characteristic features of positron, electron, and muon images are shown and compared. Quite interesting examples of crossed foils of copper and tungsten foils are shown and an explanation is given. Finally, a strong positron source at J‐PARC (Japan Proton Accelerator Research Complex) is proposed. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Development of a method to investigate interactions between positronium and the surface of fine particles
Authors: Saito Fuminori , Saito Kotaro , Hyodo Toshio 
Published: October 2009

AbstractA method is developed to use positronium (Ps) formed in silica nanoparticle aggregate to study the surfaces of various particles. The method is demonstrated with the study of the interactions of Ps with noble metal fine particles in which Ps is not formed. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
PALS investigation of chromium effect in ferritic/martensitic steels implanted with helium
Authors: Sojak Stanislav , Kršjak Vladimír , Slugeň Vladimír , Petriska Martin , Veterníková Jana 
Published: October 2009

AbstractChromium is an element with significant effect on the elevated temperature corrosion resistance and the low radiation induced void swelling. There were several studies carried out with regard to effect of Cr on the defect creation and stability [1, 2], but this issue is not fully understood yet. This paper contributes to this research with the study of Fe‐Cr binary alloys with different Cr content, implanted by helium by the use of cascade accelerator and investigated by conventional PALS set‐up. Our measurements show that chromium plays a role in the formation of small vacancy clusters, affecting the size and distribution of these defects. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Microstructure and positron behavior in FeCl3 doped PVA/PVP blend
Authors: Ravindrachary V. , Bhajantri R. F. , Harisha A. , Ismayil  , Ranganathaiah C. 
Published: October 2009

AbstractWe are reporting the positron behaviour in transition metal chloride FeCl3 doped PVA/PVP (50:50) blend. Pure and FeCl3 doped blend films were prepared using solution casting method and studied using X‐ray Diffraction (XRD) and Positron Annihilation Lifetime Spectroscopy (PALS). XRD studies show that the doping increases the amorphous nature of the blend and the PALS studies reveal that the o‐Ps lifetime (τ3) and intensity (I3) decreases with increase in FeCl3 doping level. This is due to chemical quenching and inhibition process of Ps due to doping concentration, which are discussed in the text. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Do tropical cyclones intensify by WISHE?
Authors: Montgomery Michael T. , Sang Nguyen Van , Smith Roger K. , Persing John 
Published: October 2009

AbstractIn this paper we seek and obtain a basic understanding of tropical cyclone intensification in three dimensions when precipitation and evaporative‐cooling (warm rain) processes are included. Intensification with warm rain physics included is found to be dominated by highly localized deep convective structures possessing strong cyclonic vorticity in their cores—dubbed ‘Vortical Hot Towers’ (VHTs). Unlike previous studies, the findings herein suggest an intensification pathway that is distinct from the ‘evaporation–wind’ feedback mechanism known as wind‐induced surface heat exchange (WISHE), which requires a positive feedback between the azimuthal‐mean boundary‐layer equivalent potential temperature and the azimuthal‐mean surface wind speed underneath the eyewall of the storm. Intensification from a finite‐amplitude initial vortex is shown to not require this evaporation–wind feedback process. Indeed, when the surface wind speed in the sea‐to‐air vapour fluxes is capped at a nominal (trade‐wind) value, the vortex still intensifies by the same pathway identified in the main experiments via the generation of locally buoyant VHTs and the near‐surface convergence that the VHTs induce within the boundary layer.The present findings and interpretations challenge the prevailing view that tropical cyclones are premier examples of vortical systems arising from WISHE. Given the potential significance on our understanding of the dynamics of hurricanes, and given the limitations of the present modelling framework, further tests of these predictions are advocated. Copyright © 2009 Royal Meteorological Society
Architecture and protocol design for a pervasive robot swarm communication networks
Authors: Li Ming , Harris John , Chen Min , Mao Shiwen , Xiao Yang , Read Walter , Prabhakaran B. 
Published: October 2009

AbstractThere has been increasing interest in deploying a team of robots, or robot swarms, to fulfill certain complicate tasks such as surveillance. Since robot swarms may move to areas of far distance, it is important to have a pervasive networking environment for communications among robots, administrators, and mobile users. In this paper, we first propose a pervasive architecture to integrate wireless mesh networks and robot swarm networks to build a robot swarm communication network within the areas of special interest. Under the proposed architecture, one or more robots can get connected with a nearby mesh router and access the remote server, while a self‐organizing mobilead hocnetwork is formed within each swarm for communications among the robots. We then address and analyze many important issues and challenges. Finally, we describe our work to enable this architecture through a scalable algorithm for autonomous swarm deployment and ROBOTRAK, a socket‐based‐swarm monitoring and control toolkit. Extensive simulation results and demonstrations are presented to show the desirable features of the proposed algorithm and toolkit. Copyright © 2009 John Wiley & Sons, Ltd.
CARS – Computer Assisted Radiology and Surgery
Authors: Lemke Heinz U. 
Published: October 2009

Einleitung
Innovative Entwicklungen zur CAD und CAT als auch ihre klinischen Anwendungen werden unter dem Begriff Computer Assisted Radiology and Surgery (CARS) zusammengefasst. Mit einer ständig wachsenden Anzahl von interdisziplinären und internationalen durchgeführten Forschungs- und Entwicklungsaktivitäten trägt CARS wesentlich dazu bei, dass ein signifikanter Teil der Medizin sich in einem fundamentalen Wandel hin zu einer Digitalisierung befindet.
Antioxidant-enriched enteral nutrition and immuno-inflammatory response after major gastrointestinal tract surgery
Authors: van Stijn Mireille F. M. , Boelens Petra G. , Richir Milan C. , Ligthart-Melis Gerdien C. , Twisk Jos W. R. , Diks Jeroen , Houdijk Alexander P. J. , van Leeuwen Paul A. M. 
Published: October 2009

Major surgery induces an immuno-inflammatory response accompanied by oxidative stress that may impair cellular function and delay recovery. The objective of the study was to investigate the effect of an enteral supplement, containing glutamine and antioxidants, on circulating levels of immuno-inflammatory markers after major gastrointestinal tract surgery. Patients (n21) undergoing major gastrointestinal tract surgery were randomised in a single-centre, open-label study. The effects on circulating levels of immuno-inflammatory markers were determined on the day before surgery and on days 1, 3, 5 and 7 after surgery. Major gastrointestinal surgery increased IL-6, TNF receptor 55/60 (TNF-R55) and C-reactive protein (CRP). Surgery reduced human leucocyte antigen-DR (HLA-DR) expression on monocytes. CRP decrease was more pronounced in the first 7 d in the treatment group compared with the control group. In the treatment group, from the moment Module AOX was administered on day 1 after surgery, TNF receptor 75/80 (TNF-R75) level decreased until the third post-operative day and then stabilised, whereas in the control group the TNF-R75 level continued to increase. The results of the present pilot study suggest that enteral nutrition enriched with glutamine and antioxidants possibly moderates the immuno-inflammatory response (CRP, TNF-R75) after surgery.
Trends in food intake in French children from 1999 to 2007: results from the INCA (étude Individuelle Nationale des Consommations Alimentaires) dietary surveys
Authors: Lioret Sandrine , Dubuisson Carine , Dufour Ariane , Touvier Mathilde , Calamassi-Tran Gloria , Maire Bernard , Volatier Jean-Luc , Lafay Lionel 
Published: October 2009

The objectives of the present study were to assess the intake of different food groups in French children aged 3–17 years (n1455), and to analyse trends since a dietary survey undertaken 8 years ago. Dietary intake was evaluated using data from the 2006–7 cross-sectional INCA2 national dietary survey (étude Individuelle Nationale sur les Consommations Alimentaires), based on a 7 d food record. Dietary intake (percentage of subjects consuming the food group and amount eaten) was assessed for thirty-nine food categories. We observed variations in food consumption by age, sex, North–South regional gradient, seasonal period and educational level of the responding parent. Trends in dietary intake between 1999 and 2007 were determined by comparing the INCA1 (n1126) and the INCA2 surveys. Both surveys had been carried out using the same methodology. The findings showed a decrease in energy intake in children aged 3–14 years, due to a reduction in the consumption of foods of animal origin and sweetened products. In adolescents aged 15–17 years, energy intake remained rather stable; during this 8-year period, the consumption of meat decreased, whereas the consumption of savoury snacks such as sandwiches and hamburgers significantly increased. These trends occurred during a time of growing concern about overweight and the associated co-morbidities in France. A number of public health measures were implemented over this period to improve dietary habits and physical activity patterns in children and adults. The periodic monitoring of dietary patterns through the INCA surveys is an essential part of the surveillance network in France.
The association between dietary protein intake and bone mass accretion in pubertal girls with low calcium intakes
Authors: Zhang Qian , Ma Guansheng , Greenfield Heather , Zhu Kun , Du Xueqin , Foo Leng Huat , Hu Xiaoqi , Fraser David R. 
Published: October 2009

To assess the association between protein intakes and bone mass accrual in girls, data were analysed for 757 pre-pubertal girls (mean age 10·1 years) in urban Beijing, China, who participated in a 5-year study including 2 years of milk supplementation (intervention groups only) and 3 years of follow-up study. At 0, 12, 24, 48 and 60 months from the baseline, bone mass of the proximal or distal forearm (PF or DF) and total body (TB) was measured with dual energy X-ray absorptiometry; dietary intakes were assessed by a 3-d food record (including two weekdays and one weekend day). Linear mixed models were used and continuous variables were logarithm transformed. The mean longitudinal Ca intake (432–675 mg/d on average) positively influenced bone mineral content (BMC) at TB, PF and DF after controlling for baseline bone mass and other possible confounders. However, negative associations were observed between protein intake (55·9–61·0 g/d on average) and BMC accrual at TB, PF or DF (β = − 1·92, − 10·2 or − 4·82, respectively, P < 0·01) after adjustment. When protein intake was considered according to animal or plant food sources, protein from animal foods, particularly meat, had significant negative effects on BMC accrual at DF or PF after adjustment. It was concluded that higher protein intake, especially from animal foods, appeared to have a negative effect on bone mass accrual in Chinese pubertal girls with low Ca intakes.
Identification and metabolite profiling ofSitophilus oryzaeL. by 1D and 2D NMR Spectroscopy
Authors: Trivedi A. , Kaushik P. , Pandey A. 
Published: October 2009

AbstractThe polyphagous insectSitophilus oryzaeL. (Coleoptera:Curculionidae) has a tremendous adaptability in feeding behaviour, making it a serious invasive pest of stored cereals. The present study identifies the metabolite composition ofSitophilus oryzae(S. oryzae) using Nuclear Magnetic Resonance (NMR) spectroscopy. Assignment of 1D-proton by NMR,1H-1H COSY, 2D-TOCSY1H-1H, had been done. Amongst the various biochemically important metabolites isoleucine, valine, leucine, β-hydroxybutyrate, lysine, glutamate, glutamine, proline, lactate, alanine, di-methylamine, α-glucose, β-glucose, choline, glycerophosphorylcholine and tyrosine are present inS. oryzae. In wheat-fedS. oryzae, the presence of threonine and the absence of lactate is observed. In rice-fedS. oryzae, however, the presence of lactate and the absence of threonine were observed. Barley-fedS. oryzaeshows presence of both tyrosine and lactate. It is concluded that the pestS. oryzaehas adaptability on different stored cereals and grains, depicting the presence of earlier reported metabolites. The present study aims to identify the key metabolic components and associated enzymes inSitophilus oryzaefed on different cereals.
Adult fecundity, host plant preferences, field activity and parasitism in the leaf weevilPhyllobius pyri(L.) (Coleoptera: Curculionidae)
Authors: Billiald H.E. , Straw N.A. , Stewart A.J.A. 
Published: October 2009

AbstractAdults of the leaf weevilPhyllobius pyri(L.) (Coleoptera: Curculionidae) feed on a wide variety of broadleaved trees and occasionally cause severe defoliation in newly established farm woodlands. There is little information, however, on the relative susceptibility of different tree species to damage or on the habitat associations of adults and larvae ofP. pyri, which might indicate the conditions that predispose trees to attack. Captures of adultP. pyriin emergence and flight traps in the current study indicated population densities in grassland of 0.5–6.4 adults per m2at emergence but higher densities up to 13.5 per m2in young pine plantations, where there was a mixture of grassy patches and young, naturally regenerating birch trees. The close proximity of larval food resources (grass roots) and a favoured adult host-plant, which also occurs in young farm woodlands, provided ideal conditions forP. pyriand allowed high population densities to develop. Feeding and performance experiments indicated that cherry, birch, oak and hornbeam were most susceptible toP. pyri, whereas field maple, hawthorn, rowan, lime and especially ash were resistant. Adult femaleP. pyriemerged in May reproductively immature and fed on tree foliage for 15.9±0.9 days before laying their first batch of eggs. Adults lived for 33.3±1.5 days, on average, and females laid a mean of 191.9±34.5 eggs (maximum=589) during their lifetime. Eggs hatched after 16–20 days. During 2003 and 2004, 11–16% of adultP. pyriwere parasitised byPygostylus falcatus(Hymenoptera: Braconidae) and 19–29% were parasitised byRondania fasciata(Diptera: Tachinidae).