bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract: Magnetic and thermal anomalies of Invar alloys
Authors: Matsui M. , Adachi K. , Chikazumi S. 
Published: February 2003

The anomalous thermal expansion coefficient of Fe-Ni Invar alloys has been well explained1) in terms of the two-state model of an Fe atom.2) The analysis of the thermal expansion coefficient (α) of disordered phase of Fe-Pt Invar alloys in terms of the Grüneisen equation shows that the anomalous part of α has negative values in the whole temperature region with monotonic temperature dependence and remains even at high tempertures above the ferromagnetic Curie point. These behaviors are similar to that of Fe-Ni Invar alloys. The ferromagnetic moment becomes unstable in the Invar region. The calculation of a molecular field approximation in terms of the two-state model, assuming the distribution of the ferromagnetic nature of the high spin state as well as the low spin state, shows that the magnetic moment at 0 °K and Curie point decrease and the temperature dependence of the magnetization deviates from the Brillouin function in the Invar region. The temperature dependence of the susceptibility of Fe-Ni alloys has been measured. The inverse susceptibility deviates from the Curie-Weiss law at high temperatures. The deviation is due to the temperature dependence of the number of the low spin states of Fe atoms. It has been clarified by means of the measurement of the integrated intensity of the X-ray diffraction experiment of Fe-Ni Invar alloys that the Debye temperature decreases at low temperatures, regarded as a lattice softening effect. The static deviation effect from the ordinary lattice point is also contained in the integrated intensity of the X-ray diffraction. The static deviation of atoms is large in Invar alloys and comes from the mixing of the two states of an Fe atom.
1 M. Matsui and S. Chikazumi J. Phys. Soc. Japan 45, 453 (1978).
2 R. J. Weiss, Proc. Phys. Soc. 32, 281 (1963).
Heat transfer model for cw laser material processing
Authors: Mazumder J. , Steen W. M. 
Published: February 2003

(Received 19 September 1979; accepted for publication 12 October 1979)
A three-dimensional heat transfer model for laser material processing with a moving Gaussian heat source is developed using finite difference numerical techniques. In order to develop the model, the process is physically defined as follows: A laser beam, having a defined power distribution, strikes the surface of an opaque substrate of infinite length but finite width and depth moving with a uniform velocity in the positive x direction (along the length). The incident radiation is partly reflected and partly absorbed according to the value of the reflectivity. The reflectivity is considered to be zero at any surface point where the temperature exceeds the boiling point. This is because a ’’keyhole’’ is considered to have formed which will act as a black body. Some of the absorbed energy is lost by reradiation and convection from both the upper and lower surfaces while the rest is conducted into the substrate. That part of the incident radiant power which falls on a keyhole is considered to pass into the keyhole losing some power by absorption and reflection from the plasma within the keyhole as described by a Beer Lambert absorption coefficient. Matrix points within the keyhole are considered as part of the solid conduction network, but operating at fictitiously high temperatures. The convective heat transfer coefficient is enhanced to allow for a concentric gas jet on the upper surface as used for shielding in welding and surface treatment, but not cutting. The system is considered to be in a quasi-steady-state condition in that the thermal profile is considered steady relative to the position of the laser beam. The advantages of this method of calculation over others are discussed together with comparisons between the model predictions and experiments in laser welding, laser arc augmented welding, laser surface treatment, and laser glazing. The system is assumed to be in a quasi-steady-state condition after the keyhole initiation period which for most practical purposes may be considered instantaneous.
Calculation of solid-phase reaction rates induced by a scanning cw laser
Authors: Gold R. B. , Gibbons J. F. 
Published: February 2003

An analytical model is presented for solid-phase reactions induced by a scanning cw laser. The results are applicable for both rate-limited reactions, such as the regrowth of implanted amorphous Si, and diffusion-limited reactions, such as the formation of metal silicides. The effect of the laser is interpreted in terms of a furnace anneal at an ’’effective temperature,’’ Teff, for an ’’effective time,’’ teff. Teff is shown to be equal to the maximum laser-induced surface temperature, while teff equals the laser dwell time multiplied by a ’’dwell-time reduction factor’’ which is a rational function of several material and annealing parameters and is typically on the order of
(1)/(3) . A comparison of theory and experiment is made for the specific case of the formation of Pd2Si.
PREVENTION OF DAMAGE CAUSED BY SURAL NERVE WITHDRAWAL FOR NERVE GRAFTING
Authors: Brunelli Giorgio A. 
Published: February 2003

Sural nerve withdrawal in peripheral nerve surgery is commonly performed for grafting nerve lesions with gap. Notwithstanding its popular use, this procedure is not entirely without fault as painful neuromas can occur after the withdrawal. We have treated 24 cases of painful neuromas of sural nerve after withdrawal; 11 of which were treated surgically. A safe procedure to cure and to prevent such neuromas is described — the electrical coagulation of the stump of the nerve by slowly increasing the intensity of the current. This procedure has been devised based on the fact that electrically burnt patients do not produce painful neuromas. An experimental histological study performed on rats demonstrated that slow electrical burning of the stump of a severed nerve prevents the formation of intraneural fibrosis which, on the contrary, forms abundantly when the cut nerve is not coagulated.
SPLINTING FOR PERIPHERAL NERVE INJURY IN UPPER LIMB
Authors: Chan Rebecca K. Y. 
Published: February 2003

The prognosis and speed of peripheral nerve recovery depend very much on the level of injury, severity of injury, the surgical intervention and the subsequent rehabilitative process. Many high level injuries may take years or months for the affected peripheral nerve to recover. Prolonged muscle imbalance causes joint contractures and over-stretching of denervated muscles. Without proper care, hand function recovery may be limited even the nerve regenerated afterwards. During the nerve regeneration period, splinting is one of the most useful modality to minimise deformities, prevent joint contractures and substitute loss motor control. Proper splinting encourages early use of the injured hand in daily activities. There are different types of splinting design for median nerve palsy, ulnar nerve palsy and radial nerve palsy. Dynamic splinting techniques are frequently employed to allow early prehension activities. Other therapeutic techniques, including pressure garment and sensory re-education are useful to enhance better functional return after nerve repair.
Automatic Summarization of Open-Domain Multiparty Dialogues in Diverse Genres
Authors: Zechner Klaus 
Published: February 2003

Automatic summarization of open-domain spoken dialogues is a relatively new research area. This article introduces the task and the challenges involved and motivates and presents an approach for obtaining automatic-extract summaries for human transcripts of multiparty dialogues of four different genres, without any restriction on domain. We address the following issues, which are intrinsic to spoken-dialogue summarization and typically can be ignored when summarizing written text such as news wire data: (1) detection and removal of speech disfluencies; (2) detection and insertion of sentence boundaries; and (3) detection and linking of cross-speaker information units (question-answer pairs). A system evaluation is performed using a corpus of 23 dialogue excerpts with an average duration of about 10 minutes, comprising 80 topical segments and about 47,000 words total. The corpus was manually annotated for relevant text spans by six human annotators. The global evaluation shows that for the two more informal genres, our summarization system using dialogue-specific components significantly outperforms two baselines: (1) a maximum-marginal-relevance ranking algorithm using TF*IDF term weighting, and (2) a LEAD baseline that extracts the first n words from a text.
Dreaming and Episodic Memory: A Functional Dissociation?
Authors: Fosse Magdalena J. , Fosse Roar , Hobson J. Allan , Stickgold Robert J. 
Published: February 2003

Abstract
The activity that takes place in memory systems during sleep is likely to be related to the role of sleep in memory consolidation and learning, as well as to the generation of dream hallucinations. This study addressed the often-stated hypothesis that replay of whole episodic memories contributes to the multimodal hallucinations of sleep. Over a period of 14 days, 29 subjects kept a log of daytime activities, events, and concerns, wrote down any recalled dreams, and scored the dreams for incorporation of any waking experiences. While 65% of a total of 299 sleep mentation reports were judged to reflect aspects of recent waking life experiences, the episodic replay of waking events was found in no more than 1–2% of the dream reports. This finding has implications for understanding the unique memory processing that takes place during the night and is consistent with evidence that sleep has no role in episodic memory consolidation.
Semantic Processing in the Left Inferior Prefrontal Cortex: A Combined Functional Magnetic Resonance Imaging and Transcranial Magnetic Stimulation Study
Authors: Devlin Joseph T. , Matthews Paul M. , Rushworth Matthew F. S. 
Published: February 2003

Abstract
The involvement of the left inferior prefrontal cortex (LIPC) in phonological processing is well established from both lesion-deficit studies with neurological patients and functional neuroimaging studies of normals. Its involvement in semantic processing, on the other hand, is less clear. Although many imaging studies have demonstrated LIPC activation during semantic tasks, this may be due to implicit phonological processing. This article presents two experiments investigating semantic functions in the LIPC. Results from a functional magnetic resonance imaging experiment demonstrated that both semantic and phonological processing activated a common set of areas within this region. In addition, there was a reliable increase in activation for semantic relative to phonological decisions in the anterior LIPC while the opposite comparison (phonological vs. semantic decisions) revealed an area of enhanced activation within the posterior LIPC. A second experiment used transcranial magnetic stimulation (TMS) to temporarily interfere with neural information processing in the anterior portion of the LIPC to determine whether this region was essential for normal semantic performance. Both repetitive and single pulse TMS significantly slowed subjects' reactions for the semantic but not for the perceptual control task. Our results clarify the functional anatomy of the LIPC by demonstrating that anterior and posterior regions contribute to both semantic and phonological processing, albeit to different extents. In addition, the findings go beyond simply establishing a correlation between semantic processing and activation in the LIPC and demonstrate that a transient disruption of processing selectively interfered with semantic processing.
COLLABORATIVE TACTICS FOR NESTSITE SELECTION BY PAIRS OF BLUE FOOTED BOOBIES
Authors: Stamps Judy , Calderón-De Anda Miriam , Perez Carmen , Drummond Hugh 
Published: February 2003

Abstract
The dual concern model suggests that pairs of animals can use four different behavioural strategies to resolve disputes that arise when making joint decisions. Based on their reproductive biology, we predicted that mated pairs of blue footed boobies would use one of these strategies, collaboration, when deciding on a location for their nest. Many of the behaviour tactics diagnostic of collaboration were observed in boobies. For instance, nestsite selection was accompanied by extensive exchanges of a specialized communication signal (nestpointing), rates of nestpointing at a given site were strongly related to the likelihood that a pair would select that site for their nest, couples in which the male and female 'disagreed' about the merits of an initial site went on to investigate additional sites together ('expanding the pie'), individuals pointed at maximal rates at a site only after their partner had already pointed at that same site ('feeling out procedures'), and both sexes appeared to have 'veto power' over potential nestsites, in the sense that a site was virtually never accepted for the nest if one of the two partners failed to point at that site prior to clutch initiation. These results support the hypothesis that mated pairs of blue footed boobies may use collaborative tactics when selecting a nestsite; descriptive accounts suggest that similar tactics may occur in other birds in which mated pairs jointly decide on the location for their nest.
'LAST WORD' EFFECTS OF MALE ADVERTISING CALLS ON FEMALE PREFERENCE IN LITTLE BLUE PENGUINS
Authors: Miyazaki Masamine , Waas Joseph 
Published: February 2003

AbstractPlayback experiments were conducted to investigate how advertising call overlap between male little blue penguins, Eudyptula minor, influenced other birds along shorelines in front of breeding colonies. We used a dual-speaker design in which calls from one speaker consistently overlapped those from the other speaker. Females approached overlapping advertising calls more than overlapped calls or a silent control speaker. At a proximate level, this might have occurred because 'masking effects' obscure information in overlapped calls that females require for mate choice. Alternatively, females may simply be able to locate overlapping calls (i.e. the last call they heard) more easily. Young birds and adult males did not distinguish between calling patterns. It is possible that call overlap is associated with dominance or other quality indicators; thus, females may approach overlappers more often because they represent higher quality mates.
INFLUENCE OF COLLECTIVE FEEDING ON WEIGHT GAIN AND SIZE VARIABILITY OF ANELOSIMUS JABAQUARA LEVI 1956 (ARANEAE: THERIDIIDAE)
Authors: De Oliveira Gonzaga Marcelo , Vasconcellos-Neto João 
Published: February 2003

AbstractDifferences in the size and weight of spiders within colonies may be an important factor for determining dispersion and food distribution among nestmates. In this study we report on the variation in size of spiders from 27 colonies of A. jabaquara, collected during one year. We also conducted an experiment under laboratory conditions to test if prey size, and consequently, collective or individual capture behaviours, influence the establishment of weight differences. Female size variation within colonies was high, increasing slightly from March to September. However, from November to January the variation was much lower, probably as a consequence of the emigration of large spiders during the reproductive period. Spiders that fed on large flies in the laboratory experiment grew more and collective feeding seemed to induce a larger variation in weight among individuals. These results indicate that collective feeding promotes an unequal distribution of food in A. jabaquara colonies.
BDNF regulates spontaneous correlated activity at early developmental stages by increasing synaptogenesis and expression of the K+/Cl- co-transporter KCC2
Authors: Aguado Fernando , Carmona Maria A. , Pozas Esther , Aguiló Agustín , Martínez-Guijarro Francisco J. , Alcantara Soledad , Borrell Victor , Yuste Rafael , Ibañez Carlos F. , Soriano Eduardo 
Published: February 2003

Spontaneous neural activity is a basic property of the developing brain,which regulates key developmental processes, including migration, neural differentiation and formation and refinement of connections. The mechanisms regulating spontaneous activity are not known. By using transgenic embryos that overexpress BDNF under the control of the nestin promoter, we show here that BDNF controls the emergence and robustness of spontaneous activity in embryonic hippocampal slices. Further, BDNF dramatically increases spontaneous co-active network activity, which is believed to synchronize gene expression and synaptogenesis in vast numbers of neurons. In fact, BDNF raises the spontaneous activity of E18 hippocampal neurons to levels that are typical of postnatal slices.We also show that BDNF overexpression increases the number of synapses at much earlier stages (E18) than those reported previously. Most of these synapses were GABAergic, and GABAergic interneurons showed hypertrophy and a 3-fold increase in GAD expression. Interestingly, whereas BDNF does not alter the expression of GABA and glutamate ionotropic receptors, it does raise the expression of the recently cloned K+/Cl- KCC2 co-transporter, which is responsible for the conversion of GABA responses from depolarizing to inhibitory, through the control of the Cl-potential. Together, results indicate that both the presynaptic and postsynaptic machineries of GABAergic circuits may be essential targets of BDNF actions to control spontaneous activity. The data indicate that BDNF is a potent regulator of spontaneous activity and co-active networks, which is a new level of regulation of neurotrophins. Given that BDNF itself is regulated by neuronal activity, we suggest that BDNF acts as a homeostatic factor controlling the emergence, complexity and networking properties of spontaneous networks.
Polyol‐Mediated Synthesis of Nanoscale Functional Materials
Authors: Feldmann C. 
Published: February 2003

AbstractNanoscale functional materials such as luminescent materials (ZnS:Ag+, Cl–; LaPO4:Ce3+,Tb3+; Y2O3:Eu3+), color pigments (CoAl2O4; Cr2O3; ZnCo2O4; (Ti0.85Ni0.05Nb0.10)O2; α‐Fe2O3; Cu(Fe,Cr)O4; TiO2), transparent conducting oxides (ZnO:In3+), and catalytically active oxides (CeO2; Mn3O4; V2O5) are prepared with the polyol method. All these materials are yielded as crystalline, spherical, and almost monodisperse particles, 30–200 nm in size. Characterization is carried out based on scanning electron microscopy (SEM), X‐ray powder diffraction (XRD), optical spectroscopy, and conductance measurements. The preparation via the polyol method is singled out due to its broad and easy applicability. The resulting material properties are similar to or better than nanoscale materials prepared by other measures. Some materials and their properties, e.g., ZnS:Ag+,Cl– as a phosphor, ZnCo2O4 and Cu(Fe,Cr)O4 as pigments, and ZnO:In3+ as transparent conductive oxide, are presented for the first time at the nanoscale.
Preparation and Characterization of Blue‐Luminescent Tris(8‐hydroxyquinoline)‐aluminum (Alq3)
Authors: Cölle M. , Gmeiner J. , Milius W. , Hillebrecht H. , Brütting W. 
Published: February 2003

AbstractUsing differential scanning calorimetry (DSC) measurements in combination with structural and optical characterization we have investigated the formation conditions of different phases of tris(8‐hydroxyquinoline)aluminum (Alq3). We have identified the δ‐phase as a high‐temperature phase of Alq3 being composed of the facial stereoisomer, and report an efficient method to obtain blue luminescent Alq3 by a simple annealing process. This allows the preparation of large amounts of pure δ‐Alq3 by choosing appropriate annealing conditions, which is necessary for further characterization of this blue‐luminescent phase, and offers the possibility of fabricating blue organic light‐emitting devices (OLEDs) from this material.
Magnetic Force Microscopy Images of a Nanometer‐Sized, Purely Organic High‐Spin Polyradical
Authors: Miyasaka M. , Saito Y. , Nishide H. 
Published: February 2003

AbstractMagnetic force microscopy (MFM) was applied to study both the molecular image and the magnetic response of π‐conjugated, non‐Kekulé‐, and nondisjoint‐type poly(1,2‐phenylenevinylene) (nondisjoint refers to a molecule in which non‐bonding molecular orbitals share the same region in the molecule and a multiplet ground state is significantly stabilized) networks bearing 4‐substituted di‐tert‐butylphenoxyl moities. The polyphenoxyl radicals 1 with molecular weights of 2.6, 9.3, and 32 kDa have a substantial stability even at room temperature and in air, and molecular sizes in the nanometer range of 10, 20, and 35 nm, respectively, with a disk‐like shape. The MFM clearly shows a magnetic gradient response exactly on the position of the polyradical molecule dispersed on a graphite surface. The MFM molecular image of polyradical samples with different molecular weights and spin concentrations was examined as a nanoscale and single‐molecular‐based magnetic dot.
Organometallic Synthesis of Size‐Controlled Polycrystalline Ruthenium Nanoparticles in the Presence of Alcohols
Authors: Pelzer K. , Vidoni O. , Philippot K. , Chaudret B. , Collière V. 
Published: February 2003

AbstractRuthenium nanoparticles of controlled size have been prepared by decomposition of the organometallic precursor Ru(cod)(cot) (cod = 1,5‐cyclooctadiene, cot = 1,3,5‐cyclooctatriene) under an H2 atmosphere in either a pure alcohol or an alcohol/THF mixture as solvent and in the absence of further stabilizer. The particles were characterized by transmission electron microscopy (TEM), high‐resolution electron microscopy (HREM), X‐ray diffraction (XRD), wide‐angle X‐ray scattering (WAXS), and X‐ray photoelectron spectroscopy (XPS). The colloidal solutions are stable for long periods of time, in some cases longer than one year. TEM images reveal in most cases the presence of polycrystalline sponge‐like particles of regular spherical shape and homogeneous size or, in some cases, the presence of isolated and well‐dispersed monocrystalline particles, depending upon the alkyl chain length of the alcohol used. In all cases the size distributions are relatively narrow. WAXS and XRD analyses indicate the exclusive presence of hexagonal close‐packed (hcp) ruthenium in these materials. The size of the particles can be controlled by adjusting the reaction temperature or the composition of the solvent mixture. In case of MeOH/THF mixtures, a linear correlation was established between the solvent composition and the size of the particles in the range of 4–85 nm. In the absence of stirring, small individual monocrystalline Ru particles are formed inside superstructures that assemble in some cases into monolayers. Finally, these materials are promising in catalytic hydrogenation of arenes under mild conditions.
Dendrite‐Assisted Growth of Silicon Nanowires in Electroless Metal Deposition
Authors: Peng K. , Yan Y. , Gao S. , Zhu J. 
Published: February 2003

AbstractThis article concerns the detailed investigations on the silver dendrite‐assisted growth of single‐crystalline silicon nanowires, and their possible self‐assembling nanoelectrochemistry growth mechanism. The growth of silicon nanowires was carried out through an electroless metal deposition process in a conventional autoclave containing aqueous HF and AgNO3 solution near room temperature. In order to explore the mechanism and prove the centrality of silver dendrites in the growth of silicon nanowires, other etching solution systems with different metal species were also investigated in this work. The morphology of etched silicon substrates strongly depends upon the composition of the etching solution, especially the metal species. Our experimental results prove that the simultaneous formation of silver dendrites is a guarantee of the preservation of free‐standing nanoscale electrolytic cells on the silicon substrate, and also assists in the final formation of silicon nanowire arrays on the substrate surface.