bluuebunny/crossref_metadata_2025_split huggingface dataset:
Kinetics of nanoscale structure development during Mg-vapour reduction of tantalum oxide
Authors: Müller R. , Bobeth M. , Brumm H. , Gille G. , Pompe W. , Thomas J. 
Published: January 2008

Abstract
Electron microscopic observations revealed the development of a complex interpenetrating morphology of magnesia and tantalum after magnesium-vapour reduction of tantalum oxide powder. In the early reaction stage, a nanoscale lamellar and rod-like morphology is found. This rather regular structure decomposes and coarsens during further annealing. By leaching of magnesia, nanoporous tantalum with large inner surface area is obtained. A possible growth mechanism for the observed initial cellular structure is proposed. A theoretical analysis aims at finding the optimum process parameters in order to prepare and to stabilise especially fine magnesiatantalum structures as a base for producing highly nanoporous tantalum for capacitor applications.
Influence of external and internal length scale on the flow stress of copper
Authors: Kiener Daniel , Rester Martin , Scheriau Stefan , Yang Bo , Pippan Reinhard , Dehm Gerhard 
Published: January 2008

Abstract
The flow stress of bulk specimens is known to depend on the microstructure. With a reduction of specimen dimensions into the micrometer and nanometer regime, specimen size-effects also influence the mechanical properties. We characterized the size-dependent flow stress of copper over more than three orders of magnitude, starting from several tens of micrometers down to a few tens of nanometers. For this purpose nanoindentation, micro-compression, and tensile testing experiments were performed. Additionally, different grain sizes were generated by severe plastic deformation. The observed increase in flow stress with reduced critical dimension is discussed with respect to the different stress states and microstructures present in the reported experiments. The mechanism controlling deformation changes from dislocation pile-up for critical dimensions > 1 μm via a transition regime (1 μm > critical dimensions > 100 nm) to dislocation nucleation for critical dimensions < 100 nm.
Wetting of metals and glasses on Mo
Authors: Tomsia Antoni P. , Saiz Eduardo , López-Esteban Sonia , Benhassine Mehdi , de Coninck Joel , Rauch Nicole , Rühle Manfred 
Published: January 2008

Abstract
The wetting of low melting point metals and Si – Ca – Al – Ti – O glasses on molybdenum has been investigated. The selected metals (Au, Cu, Ag) form a simple eutectic with Mo. Metal spreading occurs under nonreactive conditions without interdiffusion or ridge formation. The metals exhibit low (non-zero) contact angles on Mo but this requires temperatures higher than 1100 °C in reducing atmospheres in order to eliminate a layer of adsorbed impurities on the molybdenum surface. By controlling the oxygen activity in the furnace, glass spreading can take place under reactive or nonreactive conditions. We have found that in the glass/Mo system the contact angle does not decrease under reactive conditions. In all cases, adsorption from the liquid seems to accelerate the diffusivity on the free molybdenum surface.
Do plastic zones form at crack tips in silicate glasses?
Authors: López-Cepero Jose M. , Wiederhorn Sheldon M. , Fett Theo , Guin Jean-Pierre 
Published: January 2008

Abstract
A number of recent studies claim that silicate glasses fracture by the formation, growth and coalescence of cavities at crack tips, in the same way as metals, but at a much smaller scale. Evidence for cavity formation comes from the examination of side surfaces of fracture mechanics specimens, at the point where the crack tip intersects the free surface. Such measurements exhibit small depressions in regions that are supposedly located in front of moving crack tips. These depressions were interpreted as cavities. In this paper, we summarize experimental results obtained using an atomic force microscope to characterize the fracture surfaces. The experimental results demonstrate an absence of residual damage on fracture surfaces that could be interpreted as cavity formation. We also observe cracks moving in glass and show that the features reported as cavities actually occur behind and not in front of the moving crack. A simulation of an atomic force microscope probe passing over the emerging tip of a crack in glass suggests that the features identified as cavities are in fact due to the roughness of the specimen surface. Our results support the view that cracks in glass propagate by brittle fracture. We find no evidence for nanoscale ductility in silicate glasses.
The compressive response of carbon fiber composite pyramidal truss sandwich cores
Authors: Finnegan K. , Kooistra G. , Wadley H. N. G. , Deshpande V. S. 
Published: January 2008

Abstract
Pyramidal truss sandwich cores with relative densities in the range 1 – 10 % have been made from carbon fiber reinforced polymer laminates using a snap-fitting method. The measured quasi-static uniaxial compressive strength increased with increasing from 1 to 11 MPa over the relative density range investigated here. A robust face-sheet/truss joint design was developed to suppress truss – face sheet node fracture. Core failure then occurred by either (i) Euler buckling () or (ii) delamination failure () of the struts. Micro-buckling failure of the struts was not observed in the experiments reported here. Analytical models for the collapse of the composite cores by Euler bucking, delamination failure and micro-buckling of the struts have been developed. Good agreement between the measurements and predictions based on the Euler buckling and delamination failure of the struts is obtained. The micro-buckling analysis indicates this mechanism of failure is not activated until delamination is suppressed. The measurements and predictions reported here indicate that composite cellular materials with a pyramidal micro-structure reside in a gap in the strength versus density material property space, providing new opportunities for lightweight, high strength structural design.
Classification tree analysis of stunting in Malian adolescent girls
Authors: Pawloski Lisa R. , Kitsantas Panagiota 
Published: January 2008

AbstractThis study examines relationships between growth data and energy expenditure, economic status, and family structure among Malian adolescent girls, aged 10–17 years living in the Segou Region of Mali. Classification and regression trees (CART) were used as the primary methodology to identify high‐risk subgroups for stunting (measured as height‐for‐age) in a sample of 1,103 Malian adolescents. Because CART has been used rarely to examine growth and development, this study provides a new way to better understand how economic status, family structure, and energy expenditure related factors influence stunting in Mali. The findings indicate that the greater the number of sisters and women in a household, the poorer the nutritional status of adolescent girls. The data also show that the presence of servants within the household may predict better nutritional success of young girls. Energy expenditure was an important predictor in the context of family structure regarding the number of sisters and the presence of servants. Wealth indicators did not appear in the final tree, suggesting that wealth may not play as great a role in predicting poor growth and nutritional status as family size and structure. In conclusion, classification trees may assist in understanding the interactive nature of predictive factors of stunting in this population, and further provide evidence for intervention programs aimed at improving the health and nutritional status of Malian adolescent girls. Am. J. Hum. Biol., 2008. © 2008 Wiley‐Liss, Inc.
Dynamic similarity predicts gait parameters for Homo floresiensis and the Laetoli hominins
Authors: Vaughan Christopher L. , Blaszczyk Maria B. 
Published: January 2008

AbstractLate in 2004, the skeletal remains of a pygmy‐sized hominin recovered from a cave on the Indonesian island of Flores were first documented, with the authors concluding that the “postcranial anatomy [was] consistent with human‐like obligate bipedalism” (Brown et al. [2004]: Nature 431:1055–1061). We have assumed that Homo floresiensis, who was estimated to be 18,000‐years‐old, walked with a gait pattern that was dynamically similar to modern man. The dynamic similarity hypothesis was also applied to the Australopithecines that left their footprints at Laetoli 4‐million‐years ago. According to this hypothesis, dimensionless gait parameters can be used in combination with known leg length or step length to calculate velocity of bipedal locomotion. We have gathered data on 20 extant modern humans to calculate the standard estimates of error when predicting gait parameters. We predict that the Homo floresiensis specimen walked at a velocity of 1.11 ± 0.14 m/s. For the Laetoli footprints, the velocity for Track 1 was estimated to be 1.03 ± 0.12 m/s and for Track 2 to be 1.14 ± 0.12 m/s. These latter values for Australopithecines are greater than prior analyses, but are in good agreement with more recent work based on evolutionary robotics. Since modern man walks at 1.44 ± 0.14 m/s, our results suggest that, despite their diminutive size, these ancient hominins were capable of ranging across a wide geographical area. Am. J. Hum. Biol., 2008. © 2008 Wiley‐Liss, Inc.
Paleoepidemiology of vertebral degenerative disease in a Pre‐Columbian Muisca series from Colombia
Authors: Rojas‐Sepúlveda Claudia , Ardagna Yann , Dutour Olivier 
Published: January 2008

AbstractMajor manifestations of vertebral degenerative joint disease were observed on a Pre‐Columbian Muisca series from the Soacha Cemetery (11th to 13th centuries) Colombia, South America. In total, 1,646 vertebrae of 83 individuals were examined. Osteophytes, vertebral body joint surface contour change (“lipping”), and vertebral body pitting were evaluated for each vertebral body. For apophyseal joints, joint surface contour change, pitting, and eburnation were recorded. Two methods of frequency calculation and five for vertebral degenerative disease diagnosis were applied and compared, allowing discussion of methodological considerations. Our study showed that 83% of individuals and 32% of vertebrae were classified as positive when diagnosed by the presence of at least one of the following manifestations: osteophytes, vertebral body joint surface contour change (“lipping”), apophyseal joint surface contour change, or eburnation (method called “Pitting excluded”). No significant differences were found between the sexes. In the youngest cohort (15–30 years), 65% of individuals and 10% of vertebrae exhibit at least one of the previously mentioned manifestations. High prevalences suggest a high level of physical activity beginning in childhood which may have accelerated the aging process in this Pre‐Columbian population. Historical data are compatible with this hypothesis. Am J Phys Anthropol, 2008 © 2008 Wiley‐Liss, Inc.
Season of birth affects short‐ and long‐term survival
Authors: Muñoz‐Tudurí Marta , García‐Moro Clara 
Published: January 2008

AbstractRecent research findings have highlighted the importance of early life conditions as risk factors for adult diseases and therefore determinants of subsequent survival. Given that individuals born during different seasons in seasonal environments experience different early‐developmental conditions, an analysis of the effects of the season of birth on survival is considered an effective approach in clarifying the influence of early life conditions on survival in later life. In the present study, we analyzed the long‐term effects of early developmental conditions in a historical population in which both nutritional levels and the burden of infectious diseases showed a seasonal variation. Using a semi‐computerized linkage process, we were able to match birth and death data for 4,646 individuals born between 1634 and 1870 in the village of Es Mercadal (Minorca Island, Spain). To determine ecological differences associated with the season of birth, we first evaluated the association between season of birth and early life survival. This analysis helped us to determine seasonal variations in early life conditions such as infectious burden and nutritional levels. The season of birth had a significant effect on long‐term survival in the birth cohort 1800–1870: summer births had a lower risk of death after age 15. We explain these results in terms of lower susceptibility to degenerative diseases in adult years due to superior in utero nutrition for summer births. These findings support the fetal origin hypothesis which states that the early life environment plays a key role in shaping the subsequent phenotype and risk of adult disease. Am J Phys Anthropol, 2008. © 2008 Wiley‐Liss, Inc.
Dimensional variation in the proximal ulna: Evaluation of a metric method for sex assessment
Authors: Cowal Lynne S. , Pastor Robert F. 
Published: January 2008

AbstractThe determination of sex is one of the fundamental assessments in the production of a biological profile for human skeletal remains, and a large number of studies have focused on evaluating sexual dimorphism metrically. A recent study of a contemporary American population presented high classification accuracies from discriminant function analysis of the proximal ulna (Grant and Jant,2003). The present research tests this method using a large sample (223 skeletons: 114 males and 109 females) from two skeletal assemblages of European origin, the documented Spitalfields Coffin‐Plate Collection (N= 171) and the archaeological Raunds Furnells Collection (N= 52). The three measurements from the original study (Grant and Jantz,2003), defined as the notch length (NL), the width of the olecranon process (OW), and the height of the coronoid process (CH) were tested, with the addition of a new variable radial notch height (RNH). Significant differences (P< 0.001) were found between male and female ulna measurements. Discriminant analysis found the original discriminant equation classified individuals with accuracies of only 40% for males but 99% for females. New discriminant functions were developed using direct and stepwise analyses of the Spitalfields sample. A direct multivariate function based on four dimensions (NL, OW, CH, RNH) produced an overall classification accuracy of 85.4% (males 82.4%; females 88.4%). A second function based on the original three measurements (NL, OW, CH) yielded nearly identical classification accuracies (males 81%; females 88.5%). Crossvalidation of the Spitalfields data using the three‐variable function yielded an overall classification rate of 84.2%. This study indicates that the ulna is sexually dimorphic but its development is population‐specific. Am J Phys Anthropol, 2008. © 2008 Wiley‐Liss, Inc.
Warfare related trauma at Orendorf, a middle Mississippian site in west‐central Illinois
Authors: Steadman Dawnie Wolfe 
Published: January 2008

AbstractSkeletal evidence of nonritual interpersonal trauma in the central Illinois valley is currently limited to the terminal prehistoric period in the region. Sixteen percent of the entire Norris Farms Oneota skeletal sample died violently, presumably because they intruded upon small groups of Mississippians who had not yet abandoned the region. Archaeological evidence of palisades, however, suggests that the region was embroiled in conflict before the Oneota arrived though the skeletal evidence supporting more than ritualized or geographically sporadic cases of scalping or embedded projectiles has been elusive. This study examines the frequency and nature of interpersonal trauma at Orendorf, a Middle Mississippian (AD 1150–1250) site at the northern periphery of the region. Nine percent (N = 25) of all 268 individuals documented at Orendorf suffered warfare‐related trauma, including 13 cases of scalping, six instances of decapitation, five individuals with healed cranial blunt force trauma, three projectile point impacts, and eight cases of projectile injuries inferred by the burial context. All of the traumatized individuals were at or above the age of 15 years and males and females were victimized equally. The trauma rate among adults is 16%, which is less than that of the Norris Farms Oneota (34%) but higher than other Mississippian groups in the Southeast. The nature of the injuries is more consistent with attacks by outsiders than codified or ritualized intragroup violence. Am J Phys Anthropol, 2008. © 2008 Wiley‐Liss, Inc.
Energy‐Efficient Syngas Production through Catalytic Oxy‐Methane Reforming Reactions
Authors: Choudhary Tushar V. , Choudhary Vasant R. 
Published: January 2008

AbstractThe considerable recent interest in the conversion of stranded methane into transportable liquids as well as fuel cell technology has provided a renewed impetus to the development of efficient processes for the generation of syngas. The production of syngas (CO/H2), a very versatile intermediate, can be the most expensive step in the conversion of methane to value‐added liquid fuels. The catalytic oxy reforming of methane, which is an energy‐efficient process that can produce syngas at extremely high space–time yields, is discussed in this Review. As long‐term catalyst performance is crucial for the wide‐scale commercialization of this process, catalyst‐related studies are abundant. Correspondingly, herein, emphasis is placed on discussing the different issues related to the development of catalysts for oxy reforming. Important aspects of related processes such as catalytic oxy‐steam, oxy‐CO2, and oxy‐steam‐CO2 processes will also be discussed.
Immobilization of Ruthenium in Organic–Inorganic Hybrid Copolymers: A Reusable Heterogeneous Catalyst for Oxidation of Alcohols with Molecular Oxygen
Authors: Matsumoto Tsutomu , Ueno Masaharu , Wang Naiwei , Kobayashi Shū 
Published: January 2008

AbstractA novel organic–inorganic hybrid ruthenium (HB Ru) catalyst for the oxidation of alcohols with molecular oxygen has been developed. The catalyst was prepared from a polystyrene‐based copolymer, which includes a trimethoxysilyl functionality, and dichlorotris(triphenylphosphine)ruthenium, [RuCl2(PPh3)3], as the metal source. A sol–gel process was employed for heterogenization of the catalyst. The choice of both ruthenium species and trialkoxysilyl‐bearing monomers was found to be important for high catalytic activity. In the presence of HB Ru corresponding to 5 mol % loading of ruthenium, the alcohols were oxidized with molecular oxygen or air at atmospheric pressure without any additives to afford the corresponding aldehydes or ketones in good to excellent yields. The catalyst could be recovered and reused at least five times without loss of activity.
Zur Erdbebenbemessung im Holzbau
Authors: Walter Burkhard , Wiesenkämper Tobias 
Published: January 2008

AbstractFast täglich erreichen uns Bilder aus Erdbebengebieten aus vielen Teil en der Welt mit zum Teil verheerenden Folgen für die Menschen, die Natur und die bebaute Umwelt. Viele wissen nicht, dass auch in Deutschland die Gefahr eines Erdbebens besteht. Selbst unter den Fachleuten ist das Thema Erdbeben in Deutschland lange vernachlässigt worden. Die bauaufsichtliche Einführung der Erdbebennorm erfolgte erstmalig 1998. Seit 2007 gilt in allen betroffenen Bundesländern verbindlich die neue Erdbebennorm aus dem Jahre 2005. Bei der Wahl der Baustoffe besteht bei vielen Fachleuten die landläufige Meinung, dass der Baustoff Holz weniger für das Bauen in Erdbebengebieten geeignet ist. Der ingenieurmäßige Umgang mit dem Baustoff Holz unter Erdbebenbeanspruchung und eine damit verbundene wirtschaftliche Bemessung von Holztragwerken sollen in diesem Aufsatz erläutert werden.Die neu eingeführte Holzbaunorm DIN 1052 ist ab Januar 2008 neben dem Eurocode alleinverbindliche Bemessungsnorm für den Holzbau. Durch das semiprobabilistische Sicherheitssystem ist die Holzbaunorm kompatibel mit der Erdbebennorm. Bei holzbaugerechter Planung und unter Berücksichtigung der Duktilität und auch der Schwingdauer der Holzbauten sind diese Gebäude hervorragend geeignet, um in Erdbebengebieten eingesetzt werden zu können.
Neue Regelungen für den Grund‐ und Tunnelbau im Bundesfernstraßenbereich – Teil II: Tunnelbau
Authors: Friebel Wolf‐Dieter , Kaundinya Ingo 
Published: January 2008

AbstractBereits in Bautechnik Heft 12/2007 [8] wurde ein allgemeiner Überblick über die Gliederung des Regel‐ und Vertragswerks für Ingenieurbauten im Bundesfernstraßenbereich (ZTV‐ING) gegeben und die neuen Regelungen für den Grundbau vorgestellt. In dieser Ausgabe werden die für den Straßentunnelbau in Deutschland geänderten und neu erarbeiteten Regelungen vorgestellt. Hierzu zählen insbesondere die neuen Regelungen zu den maschinellen Schildvortriebsverfahren und zur Abdichtung von Straßentunnelbauwerken in geschlossener und offener Bauweise.
Untersuchungen zur Porenwasserdruckentwicklung im Bereich der Ortsbrust bei maschinellen Tunnelvortrieben
Authors: Schmitt Jürgen , Stahlmann Joachim , Rehm Ulrich , Herrenknecht Martin 
Published: January 2008

AbstractZur Untersuchung der Ausbildung des Porenwasserdrucks im Bereich der Ortsbrust von maschinell aufgefahren Tunnelbauwerken wurden instationäre gekoppelte mechanisch‐hydraulische Variationsberechnungen an einem dreidimensionalen numerischen Simulationsmodell eines Erddruckschilds unter Anwendung der Finite‐Differenzen‐Methode durchgeführt. Im vorliegenden Aufsatz werden nach einer kurzen Darstellung des Stands der Forschung das Simulationsmodell, die Kalibrierungsberechnung und die Ergebnisse der Parameterstudien vorgestellt.
In vitrobiotransformation of imatinib by the tumor expressed CYP1A1 and CYP1B1
Authors: Rochat Bertrand , Zoete Vincent , Grosdidier Aurélien , von Grünigen Sandrine , Marull Marc , Michielin Olivier 
Published: January 2008

AbstractThe main objective of the study was to examine the biotransformation of the anticancer drug imatinib in target cells by incubating it with oxidoreductases expressed in tumor cells. The second objective was to obtain anin silicoprediction of the potential activity of imatinib metabolites.Anin vitroenzyme kinetic study was performed with cDNA expressed human oxidoreductases and LC‐MS/MS analysis. The kinetic parameters (KmandVmax) were determined for six metabolites. A molecular modeling approach was used to dock these metabolites to the target Abl or Bcr‐Abl kinases.CYP3A4 isozyme showed the broadest metabolic capacity, whereas CYP1A1, CYP1B1 and FMO3 isozymes biotransformed imatinib with a high intrinsic clearance. The predicted binding modes for the metabolites to Abl were comparable to that of the parent drug, suggesting potential activity.These findings indicate that CYP1A1 and CYP1B1, which are known to be overexpressed in a wide range of tumors, are involved in the biotransformation of imatinib. They could play a role in imatinib disposition in the targeted stem, progenitor and differentiated cancer cells, with a possible contribution of the metabolites toward the activity of the drug. Copyright © 2008 John Wiley & Sons, Ltd.