bluuebunny/crossref_metadata_2025 huggingface dataset:
X‐Folders: documents on the move
Authors: Rossi D.
Published: October 2005

X‐Folders is a software environment for multi‐party document‐based processes that aims at supporting the implementation of workflows involving multiple users that interact by means of documents stored in special, reactive, folders: the X‐Folders. A reaction in X‐Folders is a program whose control flow depends on the status of the folder and whose actions are invocations of local services (that can be used to interact with the documents in the folders) or of services exposed by external components. The actions performed by the actors and the reactions fired by the system flow in a sequence that drives to the accomplishment of the workflow process coordinating humans and software components using documents. Copyright © 2005 John Wiley & Sons, Ltd.
BisPNA Targeting to DNA: Effect of Neutral Loop on DNA Duplex Strand Invasion by aepPNA‐N7G/aepPNA‐C Substituted Peptide Nucleic Acids
Authors: Shirude Pravin S. , Kumar Vaijayanti A. , Ganesh Krishna N.
Published: October 2005

N7‐Alkyl‐substituted guanine (N7G) as a CH+ mimic has been introduced into aminoethylglycyl PNA (aegPNA) forming a hairpin through a neutral linker derived from bis(tetraethylene) glycol (teg‐teg). These form pH‐independent PNA2:DNA triplexes with complementary DNA sequences. The introduction of chiral, cationic aminoethylprolyl (aep) units with C and the CH+ mimic N7G in the backbone of the hairpin bisPNAs with a neutral teg‐teg linker, influenced the recognition of complementary DNA in an orientation‐selective manner. Fluorescence assay was used to examine the process of strand invasion of the target DNA duplex by the modified hairpin bisPNAs with the neutral teg linker and comparison of results of previous studies employing cationic linkers suggested the triplex formation to be a two‐step process, with the preferred formation of HG bonds in the first step. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Adhesion enhancement of steel fibers to acrylic bone cement through a silane coupling agent
Authors: Kotha S. P. , Lieberman M. , Vickers A. , Schmid S. R. , Mason J. J.
Published: October 2005

The use of a silane coupling agent (methacryloxypropyl‐trichlorosilane) to improve the mechanical properties of steel fiber‐reinforced acrylic bone cements was assessed. Changes to the tensile and fracture properties of bone cements reinforced with silane‐coated or uncoated 316L stainless steel fibers of different aspect ratios were studied. Contact‐angle measurements indicated that the coupling agent coats the metal surface through room temperature treatments in a short time (within 2 h). Push‐out tests indicated that the interfacial shear strength of silane‐coated 316L stainless steel rods is 141% higher than the uncoated rods. The elastic moduli, ultimate stresses, and fracture toughness of the silane‐coated, steel fiber‐reinforced bone cements are significantly higher than the bone cements reinforced with uncoated steel fibers. There were no differences in the tensile mechanical properties of the silane‐coated or uncoated, steel fiber‐reinforced cements after aging in a physiological saline solution, indicating that the bonding effectiveness is decreased by the intrusion of water at the metal–polymer interface. Because of possible biocompatibility issues with leaching of the silane coupling agent and no long‐term mechanical benefit in simulated aging experiments, the use of these agents is not recommended for in vivo use. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
An injection-locked, single-mode, continuous wave Ti:Sapphire laser
Authors: Amthor T , Sinther M , Walther T
Published: October 2005

We report on a single-mode, continuous wave Ti:Sapphire
laser injection-locked by an external cavity diode laser producing
up to 1 W of single-mode output. The laser features a simple
crystal temperature stabilization using a thermo-electric cooler
and can be operated without any intra-cavity elements. A pump
feedback mirror is used to increase efficiency.
Production and transport logistics scheduling with two transport mode choices
Authors: Wang Haiyan , Lee Chung‐Yee
Published: October 2005

This paper considers a new class of scheduling problems arising in logistics systems in which two different transportation modes are available at the stage of product delivery. The mode with the shorter transportation time charges a higher cost. Each job ordered by the customer is first processed in the manufacturing facility and then transported to the customer. There is a due date for each job to arrive to the customer. Our approach integrates the machine scheduling problem in the manufacturing stage with the transportation mode selection problem in the delivery stage to achieve the global maximum benefit. In addition to studying the NP‐hard special case in which no tardy job is allowed, we consider in detail the problem when minimizing the sum of the total transportation cost and the total weighted tardiness cost is the objective. We provide a branch and bound algorithm with two different lower bounds. The effectiveness of the two lower bounds is discussed and compared. We also provide a mathematical model that is solvable by CPLEX. Computational results show that our branch and bound algorithm is more efficient than CPLEX. © 2005 Wiley Periodicals, Inc. Naval Research Logistics, 2005
Design, syntheses, and characterization of new thermoplastic polyureas based on 3,4‐ethylenedioxythiophene
Authors: Ojha Uma P. , Ramesh C. , Kumar Anil
Published: October 2005

New thermoplastic polyureas labeled PUn (n = 2, 3, 4, 6, 7, 9, or 10), based on 3,4‐ethylenedioxythiophene (EDOT) with flexible aliphatic spacers, were synthesized and characterized for the first time. EDOT was chosen as a replacement for the aromatic phenyl group in conventional thermoplastics based on urea linkages to improve solubility without compromising the thermal properties. As synthesized, all the samples exhibited a semicrystalline nature. The glass‐transition and melting temperatures showed a strong dependence on the spacer length. A comparison of the thermal properties of these polyureas with the corresponding phenyl analogues indicated that EDOT was a viable heteroatomic analogue of the phenyl group to be inserted into the main‐chain polyureas without hampering their thermal stability. The polyureas with spacer lengths greater than hexamethylene formed transparent gels in N‐methylpyrrolidone, 1,1,2,2‐tetrachloroethane, and dimethyl sulfoxide. The molecular packing of the polyureas was assigned with wide‐angle X‐ray diffraction studies. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 5823–5830, 2005
New generic leak frequencies for process equipment
Authors: Spouge John
Published: October 2005

The likelihood of leaks from process equipment is a key input to any quantitative risk assessment (QRA) of process plant. This paper describes a new source of generic leak frequencies and reviews the challenges in using it for QRA.

Established leak frequencies for onshore process equipment are poor in quality because they are based on old data sources of unknown provenance, judgmentally modified. Recent data from offshore process activities provide a high‐quality data set, which appears to show that the established frequencies are much too low. Much of this discrepancy arises from the QRA practice of modeling only the most hazardous leak scenarios. Recognizing the practical difficulty of changing QRA practice to match new data, the present paper therefore describes a method of analyzing the new data to obtain leak frequencies for specific modeled scenarios.

Leaks are divided into three scenarios, allowing analysts to use frequencies for only those scenarios that are compatible with their QRA outflow modeling. Standardized leak frequencies have been developed for different types of process equipment, using leak frequency functions to ensure that consistent, nonzero frequencies are available for any equipment type and hole size. The results are consistent with traditional onshore leak frequencies, while also being traceable to specific incidents among the modern high‐quality offshore leak data. © 2005 American Institute of Chemical Engineers Process Saf Prog, 2005
Wind turbine response to parameter variation of analytic inflow vortices
Authors: Maureen Hand M. , Robinson Michael C. , Balas Mark J.
Published: October 2005

As larger wind turbines are placed on taller towers, rotors frequently operate in atmospheric conditions that support organized, coherent turbulent structures. It is hypothesized that these structures have a detrimental impact on the blade fatigue life experienced by the wind turbine. These structures are extremely difficult to identify with sophisticated anemometry such as ultrasonic anemometers. This study was performed to identify the vortex characteristics that contribute to high‐amplitude cyclic blade loads, assuming that these vortices exist under certain atmospheric conditions. This study does not attempt to demonstrate the existence of these coherent turbulent structures. In order to ascertain the idealized worst‐case scenario for vortical inflow structures impinging on a wind turbine rotor, we created a simple, analytic vortex model. The Rankine vortex model assumes that the vortex core undergoes solid body rotation to avoid a singularity at the vortex centre and is surrounded by a two‐dimensional potential flow field. Using the wind turbine as a sensor and the FAST wind turbine dynamics code with limited degrees of freedom, we determined the aerodynamic loads imparted to the wind turbine by the vortex structure. We varied the size, strength, rotational direction, plane of rotation, and location of the vortex over a wide range of operating parameters. We identified the vortex conformation with the most significant effect on the blade root bending moment cyclic amplitude. Vortices with radii on the scale of the rotor diameter or smaller caused blade root bending moment cyclic amplitudes that contribute to high damage density. The rotational orientation, clockwise or counter‐clockwise, produces little difference in the bending moment response. Vortices in the XZ plane produce bending moment amplitudes significantly greater than vortices in the YZ plane. Published in 2005 by John Wiley & Sons, Ltd.
The integrated development of network complexity modulates the diverse evolutionary mutation rates of individual proteins
Authors: Fernández Ariel
Published: October 2005

The rate of evolution‐related mutation varies widely among proteins while the unity of the organism implies an integrated evolution of its protein network. Focusing on the yeast interactome, we monitored the structural impact of amino acid substitution on yeast proteins with reported structure. The impact of mutation in creating or deleting structural markers for interactivity varies across proteins and modulates the evolutionary rates, yielding a unified kinetic law of accumulation of connectivities consistent with an integrated evolution of the interactome.
Osmotic regulation of STAT3 stability in H4IIE rat hepatoma cells
Authors: Lornejad-Schäfer Mohammad Reza , Albrecht Ute , Poppek Diana , Gehrmann Thor , Grune Tilman , Bode Johannes G. , Häussinger Dieter , Schliess Freimut
Published: October 2005

Little is known about the regulation of signal transducer and activator of transcription (STAT) stability. Here the osmolarity‐dependence of STAT3 stability, ubiquitination, Tyr705 phosphorylation, STAT3 transactivation and γ‐fibrinogen (γ‐FBG) expression was studied in hepatoma cells. Hyper‐osmolarity accelerated STAT3 degradation which was prevented by proteasome inhibitors. Hypo‐osmolarity stabilized STAT3, most likely due to a decrease in STAT3 ubiquitination. Accordingly, STAT3 Tyr705 phosphorylation, α2‐macroglobulin promoter activity and γ‐FBG expression were osmosensitive. Modulation of STAT3 stability may contribute to a hydration dependence of acute phase protein expression.
The long‐run stock performance of preferred stock issuers
Authors: Howe John S. , Lee Hongbok
Published: October 2005

We examine the long‐run common stock performance of preferred stock issuers. We find that significant abnormal underperformance is present only for 1 year after the issue. For the longer term we do not find consistently significant abnormal performance. This result contrasts with substantial underperformance of common equity and debt issuers during the 3 or 5 years post‐issue. The better long‐run performance of preferred issuers relative to common equity and debt issuers is driven primarily by financial firms' motivation to issue preferred stock to satisfy regulatory requirements of capital adequacy.
How a Wet Tropical Rainforest Copes with Repeated Volcanic Destruction
Authors: Jago Leigh C.F. , Boyd William E.
Published: October 2005

The Holocene Period for the province of West New Britain, Papua New Guinea, is characterised by periodic catastrophic volcanism. The region is mantled in dense wet tropical rainforest, and has been occupied by people since the Pleistocene. Analyses of peat from two nearby sites within a lowland rainforest environment provide us with a macro-level landscape account of the periodic destruction and recovery of the coastal forests during seven periods of volcanic activity in the latter part (∼2900 yr ago to present) of the Holocene. Radiocarbon dating shows the very close correlation of the peat and tephra layers at both sites, yet the pollen analysis reveals different vegetation communities. These initial results allow us to begin identifying the processes of recovery, and to recognise different ecological pressures placed on vegetation at these neighbouring sites. Evidence of hydrological changes are observed beginning with a marine incursion recorded at Garu Site 3 ∼1360 14C yr B.P. The distinct differences in the vegetation re-establishment and community regeneration rates suggest the greater level of disturbance at Garu Site 1 could be related to the depth of the ashfall, although the proximity of a known human settlement may also be a contributing factor. Of note, palynologically, we found that the fern spore flora is particularly rich and believe it will be useful for ecological interpretation.
USING INDIRECT METHODS TO UNDERSTAND THE IMPACT OF FORCED MIGRATION ON LONG-TERM UNDER-FIVE MORTALITY
Authors: SINGH KAVITA , KARUNAKARA UNNI , BURNHAM GILBERT , HILL KENNETH
Published: October 2005

Despite the large numbers of displaced persons and the often-lengthy periods of displacement, little is known about the impact of forced migration on long-term under-five mortality. This paper looks at the Brass Method (and adaptations of this method) and the Preceding Birth Technique in combination with a classification of women by their migration and reproductive histories, in order to study the impact of forced migration on under-five mortality. Data came from the Demography of Forced Migration Project, a study on mortality, fertility and violence in the refugee and host populations of Arua District, Uganda and Yei River District, Sudan. Results indicate that women who did not migrate in a situation of conflict and women who repatriated before the age of 15, had children with the highest under-five mortality rates compared with women who were currently refugees and women who repatriated after the age of 15.
Is there an ‘End’ to Philosophical Scepticism?
Authors: Alweiss Lilian
Published: October 2005

P F Strawson advocates a descriptive metaphysics. Contrary to Kant, he believes that metaphysics should be ‘content to describe the actual structure of thought about the world’, there is no need of postulating a world that lies beyond our grasp. We neither need to refute nor accept scepticism since we can ignore it with good reasons. Yet this paper argues that Strawson fails to provide us with good reasons. He fails to realise that one cannot do metaphysics by construing its claims as being merely descriptive of a conceptual scheme we find ourselves to possess without even purporting to establish the legitimacy of that scheme. The paper shows that it is possible to overcome this impasse if we endorse Kant's transcendental idealist position. The significance of Kant' position is that it not only allows us to describe our conceptual scheme but moreover that it acknowledges that the world may be (radically) otherwise without however instantiating the truth of scepticism
Philosophy's Neglect of the Arts
Authors: Magee Bryan
Published: October 2005

It is widely agreed that the arts can give us some of the most valuable and profound experiences of which we are capable, yet the conceptions of experience to which epistemology has addressed itself during its long history have usually omitted experience of the arts. This has had harmful consequences, because it has led to theories of experience being accepted which would have been falsified by a consideration of experience of the arts. The error still occurs, and there are important current examples of it: for instance, some widely held theories about the relationship between thought and language do not survive attempts to apply them to the thought-processes involved in composing a double fugue.
Sperm competition and the evolution of sperm midpiece volume in mammals
Authors: Anderson M. J. , Nyholt J. , Dixson A. F.
Published: October 2005

Sperm competition occurs when the gametes of two, or more, males compete for opportunities to fertilize a given set of ova. This study examined whether mammalian sperm morphology could be affected by sexual selection. Comparisons were made of linear and volumetric measurements of the sperm head, midpiece and flagellum for 123 species representing 71 genera of mammals having either single partner mating systems or multiple partner mating systems. Sperm midpiece volume was found to be significantly larger in those species were females mate with more than one male during a single peri‐ovulatory period. A positive correlation was also found between relative testes sizes and sperm midpiece volumes, while no relationship was found with any other sperm measure. These results indicate that, within mammals, the evolution of sperm midpiece volume has been affected by selection pressures resulting from sperm competition. The significance of these findings may relate to the density of mitochondria within the sperm midpiece. The mitochondria provide the energy required for sperm motility, in the absence of glycolytic support. A higher mitochondrial loading may therefore be associated with enhanced sperm motility.
Greek and the phylum Porifera: a living language for living organisms
Authors: Voultsiadou Eleni , Gkelis Spyros
Published: October 2005

This paper gives a detailed analysis of Greek language elements in sponge terminology and nomenclature, thus contributing to its comprehension by the scientists working on sponge biology and enlightening the extensive contribution of the Greek language to zoological terminology. The contemporary terminology of sponge morphology and the taxa names of the three living classes of the phylum Porifera, down to the genus level, were recorded and examined for their possible Greek origin. The analysis of the recorded material showed that 67% of the morphological terms and 78% of the taxa names were formed from Greek elements. Different patterns of term and name formation were revealed. Detailed etymological analysis is presented for all morphological terms and suprageneric taxa names built of Greek elements. The Greek words used for the formation of terms and names are listed and their English translation is given. More than 70% of the Greek words found were used only once to form terms or taxa names. The contribution of the Greek element in sponge nomenclature in all decades from 1759 up to the present was >65%, with a slightly decreasing trend during the last two decades.
Task-Specific Knowledge of the Law of Pendulum Motion in Children and Adults
Authors: Frick Andrea , Huber Susanne , Reips Ulf-Dietrich , Krist Horst
Published: October 2005

The present experiment investigated children and adults’ knowledge of the pendulum law under different task conditions. The question asked was whether adults and fourth-graders knew that the period of a pendulum is a function of pendulum length but is independent of its mass. The task was to judge the period on a rating scale (judgment task), to imagine the swinging pendulum and indicate the corresponding time interval (imagery task), or to adjust the period of a dynamically presented pendulum (perception task). Normative consideration of pendulum length as the only relevant factor was primarily found in the perception task and, for adults, in the imagery task, whereas in the judgment task, children and adults frequently considered the irrelevant dimension of mass. Most children showed poor imagery performance. Preceding adjustment (perception task) and rating (judgment task) had no differential influence on subsequent imagery performance.
Remote origins of interannual variability in the Indonesian Throughflow region from data and a global Parallel Ocean Program simulation
Authors: McClean Julie L. , Ivanova Detelina P. , Sprintall Janet
Published: October 2005

The mean and interannual variability of the thermal structure of the World Ocean Circulation Experiment (WOCE) repeat IX1‐expendable bathythermograph (XBT) transect between Java and Western Australia were compared statistically for the years 1987–1997 with concurrent, co‐located output from a global eddy‐permitting configuration of the Parallel Ocean Program (POP) model forced with realistic surface fluxes. Dominant variability at long timescales for both model and data in the southern IX1 region was associated with Pacific El Niño–Southern Oscillation (ENSO) events; at the northern end it was due to remote equatorial Indian Ocean forcing and Indian Ocean Dipole Mode events. In the Indo‐Pacific domain the model reproduced the structure and magnitude of observed low‐frequency variability. Event analyses following the warm ENSO phase showed low‐frequency off‐equatorial Rossby waves interacting with the North Pacific western maritime boundary to reflect onto the equator and excite a coastally trapped response that propagated through the Indonesian seas and along the northwest coast of Australia. In turn, the signal progressively propagated away from this coast as free baroclinic Rossby waves to 90°E. Cross‐spectral analyses confirmed that on interannual timescales, both off‐equatorial and equatorial signals remotely forced in the Pacific were largely responsible for the strong observed and modeled variability at the southern end of IX1.
Estimates of CO emissions from open biomass burning in southern Africa for the year 2000
Authors: Ito Akinori , Penner Joyce E.
Published: October 2005

This paper compares the results of emission estimates of trace gases from open vegetation fires in southern hemisphere Africa for the year 2000 using different data sets. The study employs several approaches, deriving carbon monoxide (CO) emissions from a variety of satellite information, measurement data sets, and empirically‐based techniques to estimate burned areas (BA), fuel consumption (FC), and emission factors (EF). Three BA data sets are used: the Moderate Resolution Imaging Spectroradiomter (MODIS) burned area data set, the Global Burned Area data set for the year 2000 (GBA2000), and the Global Burn Scar Atlas (GLOBSCAR) in July and September, 2000. The estimated total BA in southern Africa varies significantly among data sets from 210,000 to 830,000 km2for the sum of July and September. Temporal and spatial variations associated with CO emissions are analyzed using three different techniques for calculating the FC and EF. The first set of FC and EF extrapolates monthly variations in Zambia to southern Africa, the second extrapolates spatially resolved data for September to July, and the last includes monthly and spatial variations in both FC and EF. This analysis suggests the importance of accounting for the temporal and spatial variations in both FC and EF in order to determine the appropriate temporal and spatial variations of emissions from open vegetation fires. The CO emissions from open vegetation burning for the sum of July and September range from 18 to 31 Tg CO, using the MODIS BA data set and three different techniques for calculating FC and EF. The relative standard deviations (RSD) calculated from the three different methods are 58% for BA, 21% for FC, and 37% for EF. The best estimate of CO emissions from open biomass burning for the sum of the two months is 29 Tg CO, which may be compared to the estimates constrained by numerical models and measurements in 2000 which range from 22 to 39 Tg CO.
Hydrological consequences of Eucalyptus afforestation in the Argentine Pampas
Authors: Engel Vic , Jobbágy Esteban G. , Stieglitz Marc , Williams Mathew , Jackson Robert B.
Published: October 2005

The impacts of a 40 ha stand of Eucalyptus camaldulensis in the Pampas grasslands of Argentina were explored for 2 years using a novel combination of sap flow, groundwater data, soil moisture measurements, and modeling. Sap flow measurements showed transpiration rates of 2–3.7 mm d−1, lowering groundwater levels by more than 0.5 m with respect to the surrounding grassland. This hydraulic gradient induced flow from the grassland areas into the plantation and resulted in a rising of the plantation water table at night. Groundwater use estimated from diurnal water table fluctuations correlated well with sap flow (p < 0.001, r2 = 0.78). Differences between daily sap flow and the estimates of groundwater use were proportional to changes in surface soil moisture content (p < 0.001, r2 = 0.75). E. camaldulensis therefore used both groundwater and vadose zone moisture sources, depending on soil water availability. Model results suggest that groundwater sources represented ∼67% of total annual water use.
Global distribution and sources of dissolved inorganic nitrogen export to the coastal zone: Results from a spatially explicit, global model
Authors: Dumont E. , Harrison J. A. , Kroeze C. , Bakker E. J. , Seitzinger S. P.
Published: October 2005

Here we describe, test, and apply a spatially explicit, global model for predicting dissolved inorganic nitrogen (DIN) export by rivers to coastal waters (NEWS‐DIN). NEWS‐DIN was developed as part of an internally consistent suite of global nutrient export models. Modeled and measured DIN export values agree well (calibration R2 = 0.79), and NEWS‐DIN is relatively free of bias. NEWS‐DIN predicts: DIN yields ranging from 0.0004 to 5217 kg N km−2 yr−1 with the highest DIN yields occurring in Europe and South East Asia; global DIN export to coastal waters of 25 Tg N yr−1, with 16 Tg N yr−1 from anthropogenic sources; biological N2 fixation is the dominant source of exported DIN; and globally, and on every continent except Africa, N fertilizer is the largest anthropogenic source of DIN export to coastal waters.
Strain accumulation in the southern Alps (NE Italy) and deformation at the northeastern boundary of Adria observed by CGPS measurements
Authors: D'Agostino N. , Cheloni D. , Mantenuto S. , Selvaggi G. , Michelini A. , Zuliani D.
Published: October 2005

We use continuous GPS observations to investigate the rate of strain accumulation in the area affected by the 1976 Friuli earthquakes. Comparison between the motion predicted by the rigid‐rotation of Adria and the shortening observed across the study area suggests that the 2.0 ± 0.2 mm/yr motion of Adria is entirely absorbed in the southern Alps through thrusting and crustal thickening with very little or no motion transferred to the north. We use elastic dislocation modelling to investigate the rate of interseismic loading and the geometry of the shear zone at depth. The best‐fit solution indicates that a northward‐dipping creeping dislocation, whose edge is located within a 50 km wide area beneath the southern Alps, accomodates 2.1 ± 0.5 mm/yr of the Adria motion. Limited resolution on locking depth (acceptable values between 0 and 25 km) and trade‐off between dip and slip do not allow a precise reconstruction of the dislocation geometry. The range of acceptable model parameters is consistent with a 20°‐dipping dislocation, locked above 10 km depth and slipping at 2.4 mm/yr, whose geometry is suggested by seismological informations.
Frequency-dependent dielectric permittivity of salt-free charged lamellar systems
Authors: Rotenberg B. , Dufrêche J.-F. , Turq P.
Published: October 2005

We present a new model to analyze dielectric spectroscopy measurements on charged lamellar systems, with the following improvements with respect to the hitherto available models: (i) it does not rely on the hypothesis of local electro-neutrality, and allows to treat the salt-free case; (ii) the chemical exchange governing the partition between free and bound ions is properly taken into account; (iii) a fully analytical solution is provided. The variation of the frequency-dependent dielectric permittivity with both thermodynamic and kinetic characteristics of the free-bound ion equilibrium is presented. In particular, the relative weights of both relaxation modes (exchange and transport), and their characteristic frequencies are discussed. This study opens the way to the analysis of systems for which the usual models are irrelevant, such as salt-free clay gels or membranes.
Photoionization of small krypton clusters in the Kr 3d regime: Evidence for site-specific photoemission
Authors: Hatsui T. , Setoyama H. , Kosugi N. , Wassermann B. , Bradeanu I. L. , Rühl E.
Published: October 2005

Kr 3d ionization energies of small, variable size krypton clusters are investigated by photoelectron spectroscopy, where the size regime of clusters with an average size ⟨N⟩⩽30 is studied. Characteristic shifts in Kr 3d ionization energies to lower binding energies are found compared to the bare atom. These are also different from those of large krypton clusters. Moreover, we find evidence for photoionization of the krypton dimer. Its 3d ionization energy is barely shifted relative to the atomic value. Results from model calculations considering different isomers and cluster sizes as well as defect sites give evidence that the experimental results can be related to photoionization from different surface sites in variable size krypton clusters. This can be related to site-specific photoemission in small Kr clusters. The results are compared to size effects in Kr 3d near-edge features of variable size Kr clusters as well as recent results on Kr 3d photoionization of large Kr clusters.
Photovoltaic characteristics of postdeposition iodine-doped amorphous carbon films by microwave surface wave plasma chemical vapor deposition
Authors: Omer Ashraf M. M. , Adhikari Sudip , Adhikary Sunil , Uchida Hideo , Umeno Masayoshi
Published: October 2005

The amorphous carbon thin films have been deposited on silicon and quartz substrates by microwave surface wave plasma chemical vapor deposition at low temperature (<100°C) in Ar∕CH4 phase gas. Doping of iodine has been done in the postdeposited films by exposing them in iodine vapor. The photovoltaic measurements of the films were carried out before and after iodine doping. The results show dramatic decrease of optical gap from 3.4 to 0.9 eV corresponding to nondoping to iodine doping conditions, respectively. The preliminary photovoltaic characteristics of the film deposited on n-type silicon substrate under light illumination (AM1.5, 100mW∕cm2) reveal a short-circuit current density of 1.15μA∕cm2, open-circuit voltage of 177 mV and fill factor of 21.7%.
Long-band emission of microsphere lasers based on erbium-doped sol-gel silica-alumina glasses
Authors: Van Hoi Pham , Ha Chu Thi Thu , Hung Hoang Quang
Published: October 2005

This letter reports on long-band (L band) lasing whispering-gallery modes (WGMs) in microspheres based on sol-gel silica-alumina glasses doped with high concentration of erbium ions (Er+3 from 1250 to 15 000 ppm). The sol-gel method for making these Er-doped silica-alumina glasses is described. The microspheres with diameters from 40 to 200μm were built by electrical arc. The experimental results show that laser oscillations with high gain at L band were obtained with different coupling schemes, especially with forward pumping and/or backward pumping coupling. The collected laser output power of one WGM could reach to −5dBm in the L band of 1570–1610 nm.
Direct measurement of the intrinsic RC roll-off in a radio frequency single electron transistor operated as a microwave mixer
Authors: Reilly D. J. , Buehler T. M.
Published: October 2005

By operating the radio frequency single electron transistor (rf-SET) as a mixer we present measurements in which the RC roll-off of the tunnel junctions is observed at high frequencies. Our technique makes use of the nonlinear rf-SET transconductance to mix high frequency gate signals and produce difference-frequency components that fall within the bandwidth of the rf-SET. At gate frequencies >15GHz the induced charge on the rf-SET island is altered on time scales faster than the inverse tunnel rate, preventing mixer operation. We suggest the possibility of utilizing this technique to sense high frequency signals beyond the usual rf-SET bandwidth.
Synchrotron radiation x-ray photoelectron spectroscopy of Si nanocrystals grown onto Al2O3∕Si surfaces
Authors: Renault O. , Marlier R. , Gely M. , De Salvo B. , Baron T. , Hansson M. , Barrett N. T.
Published: October 2005

Synchrotron radiation x-ray photoelectron spectroscopy is used for the study of 5 nm Si nanocrystals (NCs) for applications in nonvolatile memory devices. A detailed peak shape analysis of the high-resolution Si2p core-level spectra reveals average chemical shifts for the oxidized components consistent with those observed for planar oxidation. However, a much larger Gaussian width is found for each spectral component, reflecting the important level of structural disorder in the NCs, arising from stress produced during the kinetics of the oxide shell growth. Final state contributions to the core-level spectra are also discussed.
Enhanced coercivity in B-rich nanocomposite α-Fe∕(NdPr)2Fe14B∕Fe3B hard magnetic alloys
Authors: Betancourt I. , Davies H. A.
Published: October 2005

The structures and magnetic properties of melt-spun B-rich (10 at. %) and Nb-containing nanocomposite alloys, with compositions based on the formula (Nd0.75Pr0.25)yFe90−y−xNbxB10 (y=8, 10; x=0, 2, 4) have been studied. Considerable enhancement of the intrinsic coercivity, (of 657kA∕m) together with excellent energy density (of 113kJ∕m3), were observed for y=8,x=4; while for y=10 and x=2, values of 912kA∕m and 140kJ∕m3 were attained. Results are interpreted in terms of a grain size refining effect of the Nb addition and to the more complete exchange coupling of the soft grains to the hard phase grains afforded by reduced grain sizes.
Liquid crystal phase gratings using photoregulated photocrosslinkable polymer liquid crystals
Authors: Sasaki Tomoyuki , Ono Hiroshi , Kawatsuki Nobuhiro , Kuwabara Masaomi
Published: October 2005

We have presented liquid crystal phase gratings using photoregulated photocrosslinkable polymer liquid crystals. The phase grating consists of homogeneous and 90°-twisted nematic area and shows unique polarization conversion in the diffraction process. The diffraction properties are well explained by the theory based on Jones calculus.
Ultraviolet-replicated focusing grating coupler in polymers at a wavelength of 405 nm
Authors: Suh Dongwoo , Ryu Hojun , Park Yongwoo , Paek Mun Cheol
Published: October 2005

A focusing grating coupler (FGC) in a polymer for a wavelength of 405 nm was implemented on a slab waveguide using nanoscale ultraviolet (UV) replication process. The polymer FGC with a high numerical aperture of 0.85 was designed by Bloch wave theory with the minimum spacing between adjacent grating ridges of 85 nm and replicated from the master pattern. After UV irradiation at an energy density of 2.68J∕cm2 and a loading force of 1 kN for 2 min, the replicated polymer FGC produced a spot size of 347 nm on the focal plane measured at the full width at half maximum. The out-coupling efficiency of the grating is 34%.
Direct measurements of water adsorption enthalpy on hafnia and zirconia
Authors: Ushakov Sergey V. , Navrotsky Alexandra
Published: October 2005

A commercial surface area analyzer and Calvet-type microcalorimeter were combined for measurements of heats of gas–solid interactions, providing enhanced resolution, flexibility, and throughput compared to conventional methods. Integral adsorption enthalpies for half monolayer coverage on HfO2 and ZrO2 surfaces were found to be in the range −130–190 and −110–170kJ per mole of gaseous H2O for differently prepared monoclinic phases and −70 and −90kJ∕mole for tetragonal phases from precipitation. The surface enthalpy for anhydrous tetragonal ZrO2 was derived as 1.23±0.04J∕m2 from water adsorption and high-temperature solution calorimetry data.
Characteristics of surface-wave and volume-wave plasmas produced with internally mounted large-area planar microwave launcher
Authors: Nagatsu Masaaki , Naito Katsutoshi , Ogino Akihisa , Ninomiya Keigo , Nanko Shohei
Published: October 2005

We studied discharge characteristics of microwave plasmas excited with a large-area planar microwave launcher installed internally in a 600-mm-diam cylindrical vacuum chamber. With the microwave power less than roughly 400W, we demonstrated the large volumetric volume-wave plasma (VWP) spread in the entire chamber at a pressure of 14–27Pa in He. Above 400W, the plasma discharge made a sudden transition to higher-density, uniform surface-wave plasma (SWP) having a spatial uniformity of ±3.5% over 300mm in diameter. Electron energy probability functions in the downstream region were studied using Langmuir probe measurements with Druyvesteyn method in both the SWP and VWP discharges.
Divergent effects of matrix metalloproteinases 3, 7, 9, and 12 on atherosclerotic plaque stability in mouse brachiocephalic arteries
Authors: Johnson Jason L. , George Sarah J. , Newby Andrew C. , Jackson Christopher L.
Published: October 2005

Matrix metalloproteinases (MMPs) are thought to be involved in the growth, destabilization, and eventual rupture of atherosclerotic lesions. Using the mouse brachiocephalic artery model of plaque instability, we compared apolipoprotein E (apoE)/MMP-3, apoE/MMP-7, apoE/MMP-9, and apoE/MMP-12 double knockouts with their age-, strain-, and sex-matched apoE single knockout controls. Brachiocephalic artery plaques were significantly larger in apoE/MMP-3 and apoE/MMP-9 double knockouts than in controls. The number of buried fibrous layers was also significantly higher in the double knockouts, and both knockouts exhibited cellular compositional changes indicative of an unstable plaque phenotype. Conversely, lesion size and buried fibrous layers were reduced in apoE/MMP-12 double knockouts compared with controls, and double knockouts had increased smooth muscle cell and reduced macrophage content in the plaque, indicative of a stable plaque phenotype. ApoE/MMP-7 double knockout plaques contained significantly more smooth muscle cells than controls, but neither lesion size nor features of stability were altered in these animals. Hence, MMP-3 and MMP-9 appear normally to play protective roles, limiting plaque growth and promoting a stable plaque phenotype. MMP-12 supports lesion expansion and destabilization. MMP-7 has no effect on plaque growth or stability, although it is associated with reduced smooth muscle cell content in plaques. These data demonstrate that MMPs are directly involved in atherosclerotic plaque destabilization and clearly show that members of the MMP family have widely differing effects on atherogenesis.
THE RELATIONSHIP BETWEEN ILLEGAL DRUG PRICES AT THE RETAIL USER AND SELLER LEVELS
Authors: DESIMONE JEFF
Published: October 2005

This article uses 1985–2000 DEA data on marijuana and cocaine prices in various metropolitan areas to empirically test two contrasting theories of the relationship between illegal drug prices at the retail seller and user levels. Regression results overwhelmingly reject a multiplicative model in which the ratio of prices at the two levels is constant, but strongly support an additive model in which the difference between these prices is constant. This finding reduces the attractiveness of policies aimed at raising wholesale prices, because retail price responses, and thus potential drug demand deterrence, would be substantially smaller than commonly assumed. (JEL D40, I18, K42)
THE RELATIONSHIP BETWEEN HIGH SCHOOL MARIJUANA USE AND ANNUAL EARNINGS AMONG YOUNG ADULT MALES
Authors: RINGEL JEANNE S. , ELLICKSON PHYLLIS L. , COLLINS REBECCA L.
Published: October 2005

This article uses a unique panel data set to examine the relationship between high school marijuana use and annual earnings at age 29. The authors estimate a series of OLS models that incrementally add potential confounding variables, including marijuana use at age 29. The analysis finds that part of the negative relationship reflects an indirect pathway whereby early marijuana use affects human capital accumulation, which in turn affects earnings. Moreover, the authors find evidence that the remaining association between early marijuana use and earnings, after controlling for differences in human capital, reflects the cumulative effect of marijuana use on cognitive ability and motivation. (JEL J30, I12)
Numerical Solutions for Mixed Control of Powder Reactions for Spherical, Cylindrical, or Planar Particles
Authors: Frade Jorge Ribeiro , Cable Michael
Published: October 2005

Numerical methods were developed for the kinetics of powder reactions when the process involves mixed control by diffusion and a first‐order slow interfacial reaction. Somewhat different methods are required for spherical, cylindrical, or planar particles. Use of suitable dimensionless treatment minimizes the number of relevant parameters, and the number of different cases for mixed control at the outer interface or the inner interface. These numerical solutions were used to establish the limitations of quasi‐steady‐state solutions, and to obtain a criterion to assess when the kinetics deviates significantly from diffusion control; this criterion is related to the value of krao/D, where kr is a reaction rate constant, ao is the initial particle size, and D is diffusivity.
Effects of Radiation and Hydrogen on the Fracture Resistance of Borosilicate Glasses
Authors: Moody Neville R. , Robinson Steven L. , Lucas James P. , Handrock James , Hwang Robert Q.
Published: October 2005

In this study, short bar fracture toughness samples were used to determine the effects of radiation and hydrogen on the resistance to fracture of vitreous silica and four commercial borosilicate glasses. The results showed that neither exposure to 1010 rads of γ‐radiation nor saturation to a room‐temperature‐equivalent exposure of 408 atm of hydrogen had an effect on fracture resistance. Nevertheless, when samples were saturated with hydrogen and then exposed to radiation, resistance to fracture increased significantly in some of the glasses. The increase in the resistance to fracture correlated directly with the increase in concentration of hydroxyl and hydride groups created by exposure to radiation and hydrogen. The concentration of these groups differs with glass composition and accounts for the difference in behavior between the types of glass studied.
Site‐Dependent Study of the Optical Properties of Eu3+ in Pure and Chlorine‐Doped Fluorozirconate Glasses
Authors: Soga Kohei , Uo Motohiro , Inoue Hiroyuki , Makishima Akio , Inoue Satoru
Published: October 2005

For the present study, the emission spectra and lifetimes of Eu3+ in fluorozirconate and fluorochlorozirconate glasses were measured site dependently using the fluorescence line narrowing (FLN) technique. At high excitation energies, two different types of Eu3+ sites can be distinguished in fluorozirconate glass. The introduction of chloride into this glass caused a significant effect at low excitation energy.
Fracture and Subcritical Crack Growth in Soda‐Lime Glass under Combined Modes I and II Loading
Authors: Yoda Mitsuo , Yoshikawa Yoshio , Ono K. , Ide M.
Published: October 2005

Fracture and subcritical crack growth characteristics under combined modes I and II loading were studied using the compact tension shear specimens of soda–lime glass. The maximum normal stress criterion gives a good agreement with the experimental mode I–mode II fracture toughness envelope for initially straight cracks and kinked cracks. Subcritical crack growth characteristics were determined under sustained modes I and II loading in water. The values of KI and KII were calculated approximately by replacing the subcritical kinked crack with an assumed straight crack ā, and the KImax value based on the maximum normal stress criterion was used to describe this subcritical kinked crack growth. The experimental results show that subcritical crack growth under pure mode I, pure mode II, and various combined modes I and II loading can be well described by the KImax value based on the approximate maximum normal stress criterion.
Codeposition of Free Silicon during CVD of Silicon Carbide
Authors: Yeheskel Jacob , Dariel Mordecai S.
Published: October 2005

Factors influencing the concentration and distribution of elemental silicon codeposited during chemical vapor deposition (CVD) of SiC from MTS (CH3SiCl3) and hydrogen diluted by argon are reported. The experiments were carried out in both hot‐ and cold‐wall reactors at 1383–1473 K at atmospheric pressure. Codeposition of free silicon was detected even at very low excess hydrogen, contrary to the prediction of thermochemical calculations. In the hot‐wall reactor, under conditions of high exchange rate of the feed gases, deposits of uniform composition were obtained, containing 0%–90% free silicon, depending upon feed gas composition. The deposits of pure silicon carbide consisted of β‐SiC with a microhardness of 2400 kg/mm2 at a typical formation rate of 30 μm/h. Microhardness decreased to 800 kg/mm2 with increasing silicon concentration. In the cold‐wall reactor, under impinging gas flow conditions, nonuni‐form deposition occurred: a local gradient of Si/SiC was obtained with free silicon concentrations varying gradually between 0% and 35%. Si/SiC ratios in the deposits were determined by a combination of XRD, scanning AES, and SMP.
Synthesis and Properties of CaAl2O4‐Coated AI2O3 Microcomposite Powders
Authors: Desai Priyadarshi G. , Xu Zhengkui , Lewis Jennifer A.
Published: October 2005

Novel microcomposite powders, consisting of inert cores (αAL‐Al2O3) surrounded by reactive cement‐based coatings (CaAl2O4), were synthesized by a modified Pechini process. The evolution of the crystalline CaAl2O4 phase during calcination was studied using multiple analytical techniques, including DRIFTS,13C and 27AlMAS FT‐NMR, and XRD, for both pure CaAl2O4 and CaAl2O4‐coated Al2O3 precursor powders. In both powders, decomposition proceeded via hydrocarbon chain scission and removal of ester groups at low temperatures (T < 450°C), followed by the formation of inorganic carbonates at higher temperatures (T > 450°C). These decomposition processes were accelerated by the underlying Al2O3 cores. Transmission electron microscopy (TEM) of the fully calcined powders showed that the inert αAL‐Al2O3 particles were surrounded by relatively uniform CaAl2O4 coatings ranging in thickness from approximately 10 to 100 nm.