bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Weichselian Late‐glacial in southwestern Europe (Iberian Peninsula, Pyrenees, Massif Central, northern Apennines)
Authors: de Beaulieu J. ‐L. , Andrieu V. , Ponel P. , Reille M. , Lowe J. J. 
Published: February 2007

AbstractThis paper presents a summary of Late‐glacial environmental changes in southwestern Europe (lberian Peninsula, Pyrenees, Massif Central and the northern Apennines). The emphasis is on palaeoclimatic interpretations inferred from key sites in the region from which the most detailed records are available and which have been radiocarbon dated. The earliest evidence for climatic improvement following the end of the last glacial stage is dated to ca. 15 ka BP and is found at a few sites only. By 13 ka BP, a more widespread and marked climatic improvement is evident, although it is difficult to be precise in the timing and magnitude of the event. There are significant variations in detail between the Late‐glacial records, but evidence for a significant cooling correlated with the Younger Dryas event is widespread throughout the region. Just two sites in the region provide evidence for an earlier, less emphatic phase of climatic cooling, which is tentatively equated with the ‘Older Dryas’ of continental northern Europe. Dry conditions appear to have predominated throughout the region in the later part of the Younger Dryas and the early Holocene.
Glaciotectonics of the ltterbeck ‐ Uelsen push moraines, Germany
Authors: Kluiving Sjoerd J. 
Published: February 2007

AbstractThe two Saalian push moraines of ltterbeck ‐ Uelsen, formed during the Older Saalian glaciation, consist of Tertiary and Quaternary deposits. Locally, glaciofluvial deposits are prominent as a result of reworking of older deposits by meltwater. The push moraines are built up from a number of imbricated and folded structural units, which have moved laterally and, in part, frontally from two glacial basins. Dominant structures are large, shallow and flat‐lying glaciotectonic nappes that have been displaced over distances of at lest 1 km in the direction of tectonic transport. Overprinting relations of two deformation phases give a relative age difference between the two push morianes.
Late Devensian and Holocene relative sealevel changes at Loch nan Eala, near Arisaig, northwest Scotland
Authors: Shennan Ian , Innes James B. , Long Antony J. , Zong Yongqiang 
Published: February 2007

AbstractPollen, diatom, radiocarbon and lithostratigraphical data from isolation basins in northwest Scotland are used to quantify the reference water (tide) level, indicative range and age of differenty types of isolation and connection contacts. Tendencies of sea‐level movement and relative sea‐level changes from the mid‐Lateglacial Interstadial (11.8 ka BP) to the late Holocene are constructed from these data.Relative sea‐level fell continuously from + 17.8 m OD at 11.8 ka BP to ca. + 5.2 m OD at 10.1 ka BP. From an unkown minimum between 10 ka and 9 ka BP relative sea‐level then rose to +6.3 m OD at 8.3 ka BP. The maximum Holocene sea‐level occurred within the range +6.6 m OD to +9.3 m OD between 6.6 ka BP and 4.0 ka BP before falling to present. Isobase, age‐altitude and quantitative rebound models for northwest Scotland are tested using these sealevel data, but none of the published models shows close agreement with the new results.
Late Devensian and Holocene palaeoecology and palaeoenvironments of the Morrone Birkwoods, Aberdeenshire, Scotland
Authors: Huntley Brian 
Published: February 2007

AbstractResults are presented from analyses of pollen, vascular plant macrofossils and bryophyte remains at the Morrone Birkwoods, a site in the eastern Highlands of Scotland. The sedimentary record spans the past ca. 12 500 yr and is dated by a series of radiocarbon determinations.Quantitative palaeoclimate reconstructions are made using pollen‐climate response surfaces, with the selection of analogues constrained using evidence from the macrofossil stratigraphy. The results generally are in remarkably close agreement with those reconstructed from beetle remains by Atkinson et al. The only significant discrepancy is with respect to the extent of the warming at ca. 12500 yr BP.The palaeoclimate record indicates a marked cooling that coincides in age with the ‘Older Dryas’ event and which interrupts an overall cooling trend throughout the duration of the late‐glacial interstadial that culminates in the ‘Younger Dryas’. There is also evidence of a climate fluctuation during the first 500 yr of the Holocene. The mid‐ and late Holocene record of palaeoclimate is, in contrast, remarkably invariant until the last ca. 1500 yr, during which there is evidence of a period of warming followed by a subsequent cooling; it is speculated that these may correspond to the ‘Medieval Warm Period’ and to the ‘Little Ice Age’ respectively.The Morrone Birkwoods are noted today for their sub‐Arctic vegetation and their rich flora, with the Arctic—Alpine and northern montane biogeographical elements especially well represented. The macrofossil record indicates that the flora has long had this general character, whilst both this and the pollen record indicate that the sub‐Arctic character of the vegetation has most likely persisted since earliest Holocene times.
Strandflat development and Quaternary shorelines on Tiree and Coll, Scottish Hebrides
Authors: Dawson Alastair G. 
Published: February 2007

AbstractThe islands of Tiree and Coll in the Scottish Inner Hebrides are dominated by staircases of glaciated rock‐platform surfaces in Lewisian gneiss that are interpreted here as areas of strandflat. The rock platform surfaces exhibit differential glacio‐isostatic uplift from east to west and are considered to indicate at least four separate periods of strandflat formation during prolonged intervals of Quaternary cold climate. It is suggested that many of the well‐known areas of high rock platform located farther east in the Scottish Inner Hebrides represent eroded remnants of the strandflat surfaces described here. The existence of the Tiree and Coll strandflat surfaces in conjunction with their formation during periods of Quaternary glaciation implies that they were produced during periods when mainland Scotland was ice‐covered yet when the western margin of the ice sheet was normally located east of these islands. A prominent Late‐glacial raised shoreline also occurs on both islands and declines in altitude to the west, from 22 m in northeastern Coll to 9 m in western Tiree. It is believed that this shoreline, whose regional gradient is 0.39 m km−1, may represent part of the Main Wester Ross Shoreline that was formed in the Northwest Highlands of Scotland during a period of glacial advance that interrupted the decay of the last (Late Devensian) ice sheet. The general similarity in altitude between the Late‐glacial shoreline features and rock platform surfaces implies that during each period of Quaternary strandflat formation, relative sea‐level returned to the same approximate position. This would appear to indicate that the glacio‐isostatic and glacio‐eustatic components affecting the positions of relative sea level in Scotland have remained in approximate equilibrium throughout the duration of the Quaternary.
Late middle pleistocene interglacial deposits at upper strensham, worcestershire, england
Authors: de Rouffignac C. , Bowen D. Q. , Coope G. R. , Keen D. H. , Lister A. M. , Maddy D. , Robinson J. E. , Sykes G. A. , Walker M. J. C. 
Published: February 2007

AbstractPleistocene deposits containing the disarticulated skeleton of a mammoth, and associated faunal and floral remains, were discovered in July 1990 at Upper Strensham, Worcestershire. The environmental evidence from the fauna and flora together with limited geological evidence, indicates that the deposits accumulated within a low energy fluvial environment with a surrounding marsh and restricted tree cover on, or close to, the floodplain. The patchy occurrence of trees in a species‐rich grassland is discussed, and the climatic significance of the fauna and flora is considered.The Strensham site lies within the valley of the River Avon, which is known to contain at least five altitudinally distinct river terraces. The deposits at Strensham lie beneath a terraced surface that cannot be accommodated within the existing framework of terrace development in the valley, and evidence is presented which may suggest that these deposits form a previously unrecognised fluvial unit, the Strensham Member of the Avon Valley Formation. Amino‐acid age estimates from shells taken from the fossiliferous sediments of the Strensham Member suggest a correlation with Oxygen Isotope Stage 7. This correlation suggests that the temperate deposits at this site should be correlated with the temperate phase recorded at Marsworth, Buckinghamshire and Stoke Goldington in the valley of the Great Ouse.
A Late‐glacial colluvial sequence at Watcombe Bottom, Ventnor, Isle of Wight, England
Authors: Preece R. C. , Kemp R. A. , Hutchinson J. N. 
Published: February 2007

AbstractIn a dry valley near Ventnor, Isle of Wight, thick subaerial slope deposits of Devensian Late‐glacial age overlie the Chalk. The deposits are crudely stratified chalk muds and rubble produced by frost‐shattering, and moved downslope by the release of water from melting snow‐fields and frozen ground. A laterally extensive humic horizon of a rendzina soil occurs within the sequence, clearly reflecting a period of relative slope stability. In places this horizon divides and its upper surface appears to have been disturbed, possibly by cryoturbation. Micromorphological and other analyses confirm the pedogenic origin of this humic horizon, but also demonstrate the occurrence of pedological features both above and below it. The humic horizon therefore is not a ‘buried’ soil in the strictest sense, but is part of a vertical sequence representing a single complex soil with transported, accretionary and welded components.Molluscan analyses reveal that the sequence can be divided into four local mollusc zones, showing a progressive increase in faunal diversity throughout the profile. This succession is broadly similar to other Late‐glacial sequences described from south‐east England. Minute fragments of charcoal from the lower part of the humic horizon have yielded an AMS date of 11690 ± 120 vr BP, demonstrating formation during the ‘Allerød phase’ of the Late‐glacial Interstadial. This humic horizon is correlated provisionally with the ‘Pitstone Soil’, even though existing dates from its type‐site in Buckinghamshire are somewhat younger.
Rapid late‐glacial atmospheric CO2 changes reconstructed from the stomatal density record of fossil leaves
Authors: Beerling David J. , Birks Hilary H. , Woodward F. Ian 
Published: February 2007

AbstractThe Younger Dryas stadial (11 000‐10 000 yr BP) was an abrupt return to a glacial climate during the termination of the last glaciation. We have reconstructed atmospheric CO2 concentrations from a high‐resolution sequence of fossil Salix herbacea leaves through this climatic oscillation from Kråkenes, western Norway, using the relationship between leaf stomatal density and atmospheric CO2 concentration. High Allerød CO2 values (median 273 ppmv) decreased rapidly during 130–200 14C‐years of the late Allerød to ca. 210 ppmv at the start of the Younger Dryas. They then increased steadily through the Younger Dryas, reaching typical interglacial values once more (ca. 275 ppmv) in the Holocene. The rapid late Allerød decrease in CO2 concentration preceded the Younger Dryas temperature drop, possibly by several decades. This striking pattern of changes has not so far been recorded unambiguously in temporally coarse measurements of atmospheric CO2 from ice cores. Our observed late‐glacial CO2 changes have implications for global modelling of the ocean‐atmosphere‐biosphere over the last glacial‐interglacial transition.
Optimisation of production and storage stability of the starter bacteria Streptococcus thermophilus and Lactobacillus plantarum
Authors: Selma Maria V , MacNaughtan William , Mitchell John , Waites William 
Published: February 2007

AbstractThe growth of Lactobacillus plantarum and Streptococcus thermophilus was modelled by fitting isothermal calorimetric traces to arbitrary mathematical functions. There was a correlation between certain features on the thermal trace and parameters derived from a Baranyi fit to viable count data. In the presence of 75 g L−1 lactose, S. thermophilus showed a slower rate of growth than in the presence of 5 g L−1 lactose when measured by both viable count and heat flow. A simple equation described the variation in glass transition temperature with water activity for all preparations. A master curve fit for all mortality data for S. thermophilus showed the importance of a transition temperature for the survival of freeze‐dried preparations of bacteria. The temperature at which survival began to be impaired was 15–20 °C below the glass transition temperature determined by differential scanning calorimetry. Copyright © 2007 Society of Chemical Industry
Effect of salts on the solubility of phenolic compounds: experimental measurements and modelling
Authors: Noubigh Adel , Mgaidi Arbi , Abderrabba Manef , Provost Elise , Fürst Walter 
Published: February 2007

AbstractPhenolic compounds can be found in industrial or agricultural waste, such as waste water from olive mills. Because of the environmental problem caused by this residue from olive oil production, the aim of this work was to model the effect of salts on the solubility of four phenolic compounds. For this purpose, the solubilities of gallic acid, protocatechuic acid, vanillic acid and vanillin have been measured in various chloride solutions at constant temperature. The Clegg–Simonson–Pitzer activity coefficient, together with the dissociation constant obtained from the literature, has been used to represent the equilibrium solid‐liquid data. Good agreement (3.4%) between the experimental and calculated values for solubility was obtained. Copyright © 2007 Society of Chemical Industry
Synthesis and Characterization of N‐Propargyl Cinnamamide Polymers and Copolymers
Authors: Deng Jianping , Wang Jianmin , Zhao Weiguo , Zhang Zhigang , Yang Wantai 
Published: February 2007

AbstractThis paper deals with synthesis and characterization of a novel poly(N‐propargylamide) containing cinnamamide groups (poly(1)) in its side chains. Monomer 1, CHCCH2NHCOCHCH(C6H5), was synthesized and polymerized with a rhodium catalyst, (nbd)Rh+B−(C6H5)4 (nbd = 2,5‐norbornadiene). Effects of some factors on polymerization of monomer 1 such as solvent, temperature, and the ratio of monomer/catalyst were investigated in detail; polymers with moderate number‐average molecular weights ($\overline M _{\rm n}$) and low index of polydispersity ($\overline M _{\rm w} /\overline M _{\rm n}$) were obtained. To improve the polymers' solubility and to elucidate whether poly(1) could form helical conformation, another N‐propargylamide monomer 2, CHCCH2NHCOCH(CH2CH3)2, was employed to accomplish copolymerization with monomer 1. Copolymerization with monomer 2 improved obviously the solubility of the (co)polymers; the copolymers with certain monomer ratios could form helices under the examined conditions according to the related UV‐vis spectra.magnified image
Second‐trimester uterine artery Doppler pulsatility index and maternal serum PP13 as markers of pre‐eclampsia
Authors: Spencer Kevin , Cowans Nicholas J. , Chefetz Ilana , Tal Joseph , Kuhnreich Ido , Meiri Hamutal 
Published: February 2007

AbstractObjectiveTo evaluate whether measurement of maternal serum PP13 at 22 to 24 weeks of gestation, alone or in combination with second‐trimester biochemical markers or uterine artery pulsatility measured by Doppler velocimetry, is useful in predicting those women at risk of developing pre‐eclampsia.Study DesignA nested case‐control study of pre‐eclampsia cases with controls matched for gestational age and storage time for the maternal serum. PP13 was tested by an ELISA, with the samples blinded to pregnancy outcome. All patients also underwent uterine artery Doppler flow velocimetry at 22–24 weeks to measure the mean pulsatility index (PI). Results for Inhibin, Activin, PAPP‐A and Free β‐hCG were available from previous studies.ResultsThere were 73 controls and five cases with early pre‐eclampsia in which delivery was induced prior to 35 weeks. In addition, there were a further seven cases with pre‐eclampsia in which delivery was not induced before term. Median PP13 levels for controls and all cases were 295.9 and 212.6 pg/ml, and 171.2 pg/ml amongst the early pre‐eclampsia cases, with the MoMs 1.00, 0.94 and 0.63, respectively (p < 0.001). Receiver operator characteristic (ROC) curve analysis for either all cases or early cases versus controls yielded areas under the curve of 0.588 (95% CI: 0.42–0.76; p = 0.1526) and 0.693 (0.47–0.92; p = 0.0441) for PP13. At a specificity set to 0.80, the sensitivity for PP13 in the early cases was 0.40 and that in all cases was 0.25. Combining PP13 bivariately with any of the markers (PI, PAPP‐A, Activin, Inhibin or Free β‐hCG) tested in the 22–24 week period did not improve the detection of early, late or all cases of pre‐eclampsia compared with either marker alone.ConclusionLate second‐trimester PP13 alone is unlikely to be useful in predicting pre‐eclampsia and early pre‐eclampsia, and its prediction does not increase when coupled with second‐trimester Doppler PI or other potential biochemical markers. Measuring between‐trimester temporal changes may be worthy of further investigation. Copyright © 2007 John Wiley & Sons, Ltd.
Toughening of polypropylene combined with nanosized CaCO3 and styrene–butadiene–styrene
Authors: Yu Jianghua , Wang Guoquan , Chen Jianfeng , Zeng Xiaofei , Wang Wenyi 
Published: February 2007

AbstractNanocomposites of nanosized CaCO3/SBS/PP were prepared by using twin‐screw and single‐screw extruder. By adding nanosized CaCO3 particles into SBS/PP blend, the notched impact strength, flexural modulus, and tensile strength of the composites can be improved, whereas, by adding microsized CaCO3 particles into SBS/PP blend, the notched impact strength of the composite is decreased markedly. At nanosized CaCO3 content of 16 phr (parts per hundred PP resin by weight), the impact strength of nanosized CaCO3/SBS/PP composite reaches 56.55 KJ/m2, which is 1.27 times that of SBS/PP blend. At nanosized CaCO3 content of 4 phr, the tensile strength of the composites reaches 31.3 MPa, which is 1.23 times that of SBS/PP blend. The maximum and balanced torque of the composites improves significantly by the addition of CaCO3 nanoparticles. The increased shear force during compounding continuously breaks down SBS particles, resulting in the reduction of the SBS particles size, and improving the dispersion of SBS particles in PP matrix. Thus the toughening effect of SBS on matrix was improved. Simultaneously, the existence of SBS provides the matrix with a good intrinsic toughness, satisfying the condition that nanosized inorganic particle of CaCO3 efficiently toughens polymer matrix. The synergistic toughening function of nanosized CaCO3 and SBS on PP matrix was exhibited. POLYM. ENG. SCI. 47:201–206, 2007. © 2007 Society of Plastics Engineers
Preparation, surface chemistry, and electrical conductivity of novel silicon carbide/polypyrrole composites containing an anionic surfactant
Authors: Mičušík Matej , Omastová Mária , Boukerma Kada , Albouy Aurélie , Chehimi Mohamed M. , Trchová Miroslava , Fedorko Pavol 
Published: February 2007

AbstractNovel silicon carbide/polypyrrole (SiC/PPy) conducting composites were prepared using silicon carbide as inorganic substrate in the presence or absence of an anionic surfactant, dodecylbenzenesulfonic acid (DBSA). The surface modification of SiC particles was performed in aqueous solution containing the anionic surfactant by oxidative polymerization of pyrrole using ferric chloride as oxidant. Ash content analysis was used to determine the mass loading of organic fraction in the SiC/PPy composites. Scanning electron microscopy showed the surface modification of SiC by PPy. The presence of PPy in the composites was confirmed by infrared spectroscopy. The small gradual red shift of the band of the stretching vibrations of SiCO and SiOSi bonds and more intensive of PPy spectrum were observed when DBSA was used for composite preparation. The presence of both polypyrrole and surfactant was also detected by their respective N1s and S2p core level peaks recorded by X‐ray photoelectron spectroscopy. The electrical conductivity of SiC‐DBSA/PPy composites depends on PPy content at the surface and on pyrrole/DBSA molar ratio. The DBSA‐containing composites have a conductivity about 2 orders of magnitude higher than in the case of the composites prepared without DBSA when PPy loading was lower than 15 wt%. Above this PPy loading the difference in conductivity almost diminished due to a increased amount of PPy polymerized on the surface of the SiC substrate. SiC‐DBSA/PPy composites containing 15 wt% PPy prepared using a molar ratio pyrrole/DBSA = 5, exhibited a very hydrophobic behavior compared to the corresponding DBSA‐free composites, as they floated on water and did not sediment even after a prolonged period of time. POLYM. ENG. SCI., 47:1198–1206, 2007. © 2007 Society of Plastics Engineers
Effect of P‐induced gettering on extended defects in n‐type multicrystalline silicon
Authors: Acciarri M. , Binetti S. , Le Donne A. , Marchionna S. , Vimercati M. , Libal J. , Kopecek R. , Wambach K. 
Published: February 2007

AbstractThe electrical properties and the minority charge carrier recombination behaviour of grain boundaries (GBs) and intragrain dislocations in different n‐type multicrystalline silicon (mc‐Si) ingots were systematically studied through microwave‐detected PhotoConductance Decay (µW‐PCD), Electron Beam Induced Current (EBIC) and PhotoLuminescence (PL) spectroscopy on as‐grown samples and on samples submitted to P‐diffusion step. It was confirmed that the overall quality of n‐type mc‐Si is high, indicating that n‐type‐Si is a valid source for photovoltaic applications. As expected, the average lifetime increases after the P‐diffusion process, which induces impurity gettering effects at the external surfaces, like in the case of p‐type samples, but an evident local increase of electrical activity of some GBs after that process was also observed using the EBIC mapping technique. Apparently, a redistribution of impurities occurs at the processing temperature and impurities are captured at the deepest sinks. In fact, while all GBs act as heterogeneous segregation/precipitation sites, some of them will compete with the external surfaces sinks, partly vanishing the effect of P‐gettering. Last but not least, it was experimentally demonstrated that the average lifetime values measured with the µW‐PCD technique well correlate with the recombination activity of GBs measured with the EBIC technique, showing the extreme importance of GBs on the effective lifetime of this material. Copyright © 2007 John Wiley & Sons, Ltd.
Rule of five cyclizations in 5‐hexenyl radicals and photocycloadditions of 1,5‐hexadienes: effect of 4‐oxa substitution
Authors: Matlin Albert R. , Brinton Karen Feit , Nivaggioli Belinda Tsao 
Published: February 2007

AbstractThe effect of 4‐oxa substitution on the regiochemistry and rate of 5‐hexenyl radical cyclizations was investigated, as a potential model for [2 + 2] photocycloadditions of 2‐acyl‐4‐oxa‐1,5‐hexadienes. Increasing the electron density in the alkene decreases the rate of cyclization in the 4‐oxa‐hexenyl radicals, relative to the all carbon analogs, but has little effect on the regioselectivity of the cyclization. The radical model does not reproduce the high degree of 1,6 closure, observed in the [2 + 2] photocycloadditions for 4‐oxa‐1,5‐hexadiene 1a. However, the radical model does reinforce the interpretation that ground state conformational effects, engendered by substitution remote from the reacting centers have important rate consequences for cyclization reactions. Copyright © 2007 John Wiley & Sons, Ltd.