bluuebunny/crossref_metadata_2025_split huggingface dataset:
On the linear correlation between microhardness and mechanical properties in polar polymers and blends
Authors: Giménez E , Lagarón JM , Gavara R , Saura JJ 
Published: July 2003

AbstractThe tensile elastic modulus (E), yield stress (σY) and microhardness (MH) of neat and binary and ternary blends of glassy semicrystalline ethylene–vinyl alcohol copolymer (EVOH), a glassy amorphous polyamide and a semicrystalline nylon‐containing ionomer covering a broad range of properties were examined. The tests were carried out on dry and water‐equilibrated samples to produce stiffer and softer materials, respectively. From the results, more accurate linear correlations were found to describe adequately the microhardness, modulus and yield stress of these strongly self‐associated polymers through hydrogen bonding. Copyright © 2003 Society of Chemical Industry
Preparation and properties of acrylonitrile–butadiene copolymer hybrid nanocomposites with organoclays
Authors: Nah Changwoon , Ryu Hyune Jung , Kim Wan Doo , Chang Young‐Wook 
Published: July 2003

AbstractAcrylonitrile–butadiene rubber (NBR) hybrid nanocomposites with organoclays were prepared by melt mixing, and their properties were compared with those of conventional rubber compounds filled with carbon black and silica. Based on X‐ray diffraction and transmission electron microscopy, the NBR nanocomposites obtained were found to form generally an intercalated structure, although they formed an exfoliated structure when the organoclay content was low enough, <2 parts per 100 rubber. The NBR nanocomposite showed a simultaneous improvement in ultimate strength and stiffness, which is generally in a trade‐off relation in rubbery materials. A characteristic fracture morphology of ‘laminated board‐type’ was observed for NBR nanocomposites instead of typical ‘cross‐hatched’ morphology in conventional rubber composites. The NBR nanocomposites also showed much higher hysteresis and tension set. Copyright © 2003 Society of Chemical Industry
Effect of diisopropyl thiophosphoryl‐N‐oxydiethylene sulfenamide and some disulfidic compounds in the covulcanization of NR–EPDM blends
Authors: Ghosh Arup Kumar , Basu Dipak Kumar 
Published: July 2003

AbstractSynergistic combinations of diisopropyl thiophosphoryl‐N‐oxydiethylene sulfenamide (DIPTOS) with some disulfide accelerators or sulfur donors improve the physical properties of NR–EPDM blend vulcanizates. Various combinations of DIPTOS with dibenzothiazyl disulfide (MBTS), tetramethyl thiuram disulfide (TMTD), bis(N‐oxydiethylene) disulfide (ODDS) and bis(diisopropyl) thiophosphoryl disulfide (DIPDIS) were used in this study. DIPTOS when used alone produces NR vulcanizates with a moderate range of physical properties, whereas in conjunction with MBTS and DIPDIS it exhibits significant mutual activities. Morphological studies of the tensile‐fractured surfaces of the blend vulcanizates by scanning electron microscopy corroborate the physical data. Copyright © 2003 Society of Chemical Industry
Fullerene membrane transport mediated by γ‐cyclodextrin immobilised in poly(vinyl alcohol) films
Authors: Eddaoudi Hassan , Deratani André , Tingry Sophie , Sinan Fouad , Seta Patrick 
Published: July 2003

AbstractThis paper reports on fullerene C60 and C70 transport across hydrophilic membrane materials consisting of a poly(vinyl alcohol) matrix on which γ‐cyclodextrin moieties were attached as molecular recognition sites. The rate‐limiting step of the membrane transport was demonstrated to be dissociation of the inclusion complex at the stripping interface. Copyright © 2003 Society of Chemical Industry
Study of optically active methacrylates containing 1,1′‐binaphthyl side‐groups polymerized by anionic, group transfer and free radical methods
Authors: Xue Hong , Xu Yong‐An , Song Nai‐Heng , Gao Lian‐Xun , Ding Meng‐Xian 
Published: July 2003

AbstractOptically active and racemic poly(meth)acrylates with pendant 1,1′‐binaphthalene moiety of 2‐methacryloyloxy‐ and 2‐acryloyloxy‐2′‐methoxy‐1,1′‐binaphthalene (MAMBN and AMBN) were synthesized by anionic, group transfer and free radical polymerization methods. Their polymerizability and chiroptical properties are somewhat different, depending on the three types of polymerization methods used. The yields for poly(MAMBN)s are lower than for poly(AMBN)s. The optical rotation of the optically active polymers is identical to that of the corresponding monomers. The values of specific rotation of optically active poly(AMBN)s are much larger than those of optically active poly(MAMBN)s. © 2002 Society of Chemical Industry
A theoretical framework for gain scheduling
Authors: Fromion Vincent , Scorletti Gérard 
Published: July 2003

AbstractThe weighted incremental norm approach was originally introduced as a natural framework for extending well‐known H∞ linear control concepts into the nonlinear context. In this paper, we investigate the numerous links between this new approach and the classical gain‐scheduling technique. Although based on heuristic rules, gain‐scheduled control is probably the most widespread nonlinear technique. In this paper, we point out that the control objectives of the gain‐scheduled controller design can be expressed as the weighted incremental norm minimization of a nonlinear operator. The result interest is twofold: it first provides a rigorous mathematical formulation of the gain‐scheduling problem. Furthermore, existing gain‐scheduling techniques can be interpreted as approximate solutions to the weighted incremental norm minimization of a nonlinear operator. Copyright © 2003 John Wiley & Sons, Ltd.
RobustH2filtering of linear systems with time delays
Authors: Fridman E. , Shaked U. , Xie L. 
Published: July 2003

AbstractThe problem of robustH2estimation of a combination of states of a stationary linear system with time delays is considered. Since the problem is infinite dimensional in nature, an attempt is being made to develop finite dimensional methods that will guarantee a preassigned estimation accuracy. The approach of minimizing the trace of a matrix that overbounds the exact covariance of the estimation error is considered. Sufficient conditions are given in the form of linear matrix inequalities (LMIs). The results are illustrated by a numerical example. Copyright © 2003 John Wiley & Sons, Ltd.
The lichen flora of unprotected soft sea cliffs and slopes
Authors: Gilbert Oliver L. 
Published: July 2003

AbstractSoft unprotected sea cliffs and slopes were surveyed at forty localities around the English coast and found to support a restricted lichen flora that was zoned in relation to sea-level. Bed rock composition, structural heterogeneity and high levels of instability largely control the terricolous lichen vegetation, which is predominantly composed of calcicoles typical of early successional stages. Cyanobacterial lichens are well represented. The species encountered can be arranged into three provisional assemblages characteristic of alkaline bed rock, acidic bed rock, and turf edges. Few species with maritime affinities were present but this group included rarely recorded species of Pyrenocollema and abundant Lecanora zosterae. Other rare and unusual lichens were present, often at a low density and in only a few localities. The lichen flora of soft cliffs has links with that found on urban wasteland and, remotely, with that of sand dunes.
The lichenicolous fungi of Great Britain and Ireland: an overview and annotated checklist
Authors: Hawksworth David L. 
Published: July 2003

AbstractSince the last compilation in 1983, the number of lichenicolous fungi (and lichenicolous lichens) recorded in Great Britain and Ireland has increased from 218 to 403 species (a rise of 85%). The introduction includes accounts of: the history of investigation, circumscription, phylogenetic relationships, symbiotic interactions, dispersal and establishment, distribution, culture, host restriction, and identification. The checklist enumerates the recorded species. Information is provided on the systematic position of each genus, together with the authors and dates of publication of all accepted names; synonyms used in the literature of the two countries since 1910 are cross-indexed. References to pertinent literature with descriptions and discussions are included, together with notes on particular species. The list of references cited includes 298 publications. The following new scientific names are introduced: Diederichia gen. nov., and Dactylospora scapanaria (syn. Lecidea scapanaria), Diederichia pseudevemiae (syn. Macrophomina pseudeverniae), Muellerella ventosicola (syn. Microthelia ventosicola) and Nigromacula uniseptata (syn. Vouauxiella uniseptata) combs, nov.
Luminescence chronology of late Pleistocene loess-paleosol and tephra sequences near Fairbanks, Alaska
Authors: Berger Glenn W. 
Published: July 2003

AbstractThermoluminescence (TL) and infrared-stimulated luminescence (IRSL) sediment-dating methods have been applied to paleosol- and tephra-bearing loess sequences younger than marine oxygen isotope stage (MIS) 7 at three important sites. TL ages indicate the development of significant paleosols ∼75,000 and ∼30,000 yr ago in the loess sequence at the Gold Hill site. Relatively minor soil development occurred ∼70,000 and ∼48,000 yr ago. Like the ∼75,000-yr-old soil, the 30,000-yr-old soil is apparently of global extent, and consistent in timing with inferred warm intervals elsewhere (e.g., Greenland, Europe, western and central China). At Birch Hill, replicate TL dating of primary loess combined with two earlier TL results from the same site, and with an earlier mean fission-track-glass-shard age of 140,000 ± 10,000 yr for the associated Old Crow tephra, yield a more precise numeric age of 142,300 ± 6600 yr for this Alaska/Yukon chronostratigraphic marker ash bed. Three of the TL ages at the Halfway House site are difficult to interpret, but combined with other evidence, they indicate: (1) the upper 5–6 m of loess from Halfway House is not part of the Gold Hill Loess (equivalent to pre-MIS 5 age) as long thought by T.L. Péwé, but rather is much younger; (2) the regionally significant variegated tephra, found in the Fairbanks and Klondike areas and previously thought to be older than MIS 5, has an age of 77,800 ± 4100 yr (late MIS 5).
Late Quaternary vegetation and climate history of the central Bering land bridge from St. Michael Island, western Alaska
Authors: Ager Thomas A. 
Published: July 2003

AbstractPollen analysis of a sediment core from Zagoskin Lake on St. Michael Island, northeast Bering Sea, provides a history of vegetation and climate for the central Bering land bridge and adjacent western Alaska for the past ≥30,000 14C yr B.P. During the late middle Wisconsin interstadial (≥30,000–26,000 14C yr B.P.) vegetation was dominated by graminoid-herb tundra with willows (Salix) and minor dwarf birch (Betula nana) and Ericales. During the late Wisconsin glacial interval (26,000–15,000 14C yr B.P.) vegetation was graminoid-herb tundra with willows, but with fewer dwarf birch and Ericales, and more herb types associated with dry habitats and disturbed soils. Grasses (Poaceae) dominated during the peak of this glacial interval. Graminoid-herb tundra suggests that central Beringia had a cold, arid climate from ≥30,000 to 15,000 14C yr B.P. Between 15,000 and 13,000 14C yr B.P., birch shrub-Ericales-sedge-moss tundra began to spread rapidly across the land bridge and Alaska. This major vegetation change suggests moister, warmer summer climates and deeper winter snows. A brief invasion of Populus (poplar, aspen) occurred ca.11,000–9500 14C yr B.P., overlapping with the Younger Dryas interval of dry, cooler(?) climate. During the latest Wisconsin to middle Holocene the Bering land bridge was flooded by rising seas. Alder shrubs (Alnus crispa) colonized the St. Michael Island area ca. 8000 14C yr B.P. Boreal forests dominated by spruce (Picea) spread from interior Alaska into the eastern Norton Sound area in middle Holocene time, but have not spread as far west as St. Michael Island.
Paleoecology of two marine oxygen isotope stage 7 sites correlated by the Sheep Creek tephra, northwestern North America
Authors: Schweger Charles E. 
Published: July 2003

AbstractPollen analysis at two sites, correlated by the presence of the 190,000 yr-old Sheep Creek tephra, documents fluctuations in vegetation and climate consistent with this date and indicates that the records span marine oxygen isotope stage 7 and the stage 6/7 transition. Dawson Cut, near Fairbanks, Alaska, provides a 5.2-m-long pollen record of interglacial boreal forest succeeded by shrub tundra and then forest/tundra. Ash Bend, Stewart River, central Yukon, provides a 9.5-m-long record of interglacial boreal forest succeeded by forest/tundra, shrub tundra, and herbaceous tundra. The replacement of forest at both sites by more open or tundra vegetation indicates warm interglacial conditions giving way to cold and arid climate. It is not clear whether stage 7 was warmer than the present. The warm–cool–warm climate oscillation evident at both sites may correlate to Lake Baikal substages 7a, 7b, and 7c. Sheep Creek tephra fell on forest/tundra vegetation.
Recurring middle Pleistocene outburst floods in east-central Alaska
Authors: Froese Duane G. , Smith Derald G. , Westgate John A. , Ager Thomas A. , Preece Shari J. , Sandhu Amanjit , Enkin Randolph J. , Weber Florence 
Published: July 2003

AbstractRecurring glacial outburst floods from the Yukon-Tanana Upland are inferred from sediments exposed along the Yukon River near the mouth of Charley River in east-central Alaska. Deposits range from imbricate gravel and granules indicating flow locally extending up the Yukon valley, to more distal sediments consisting of at least 10 couplets of planar sands, granules, and climbing ripples with up-valley paleocurrent indicators overlain by massive silt. An interglacial organic silt, occurring within the sequence, indicates at least two flood events are associated with an earlier glaciation, and at least three flood events are associated with a later glaciation which postdates the organic silt. A minimum age for the floods is provided by a glass fission track age of 560,000 ± 80,000 yr on the GI tephra, which occurs 8 m above the flood beds. A maximum age of 780,000 yr for the floods is based on normal magnetic polarity of the sediments. These age constraints allow us to correlate the flood events to the early-middle Pleistocene. And further, the outburst floods indicate extensive glaciation of the Yukon-Tanana Upland during the early-middle Pleistocene, likely representing the most extensive Pleistocene glaciation of the area.
Late Pliocene to late Pleistocene environments preserved at the Palisades Site, central Yukon River, Alaska
Authors: Matheus Paul , Begét James , Mason Owen , Gelvin-Reymiller Carol 
Published: July 2003

AbstractThe Palisades Site is an extensive silt-loam bluff complex on the central Yukon River preserving a nearly continuous record of the last 2 myr. Volcanic ash deposits present include the Old Crow (OCt; 140,000 yr), Sheep Creek (SCt; 190,000 yr), PA (2.02 myr), EC (ca. 2 myr), and Mining Camp (ca. 2 myr) tephras. Two new tephras, PAL and PAU, are geochemically similar to the PA and EC tephras and appear to be comagmatic. The PA tephra occurs in ice-wedge casts and solifluction deposits, marking the oldest occurrence of permafrost in central Alaska. Three buried forest horizons are present in association with dated tephras. The uppermost forest bed occurs immediately above the OCt; the middle forest horizon occurs below the SCt. The lowest forest bed occurs between the EC and the PA tephras, and correlates with the Dawson Cut Forest Bed. Plant taxa in all three peats are common elements of moist taiga forest found in lowlands of central Alaska today. Large mammal fossils are all from common late Pleistocene taxa. Those recovered in situ came from a single horizon radiocarbon dated to ca. 27,000 14C yr B.P. The incongruous small mammal assemblage in that horizon reflects a diverse landscape with both wet and mesic environments.
Trace-element geochemistry of individual glass shards of the Old Crow tephra and the age of the Delta glaciation, central Alaska
Authors: Begét James E. , Keskinen Mary J. 
Published: July 2003

AbstractTwo widespread tephra deposits constrain the age of the Delta Glaciation in central Alaska. The Old Crow tephra (ca. 140,000 ± 10,000 yr), identified by electron microprobe and ion microprobe analyses of individual glass shards, overlies an outwash terrace coeval with the Delta glaciation. The Sheep Creek tephra (ca. 190,000 yr) is reworked in alluvium of Delta age. The upper and lower limiting tephra dates indicate that the Delta glaciation occurred during marine oxygen isotope stage 6. We hypothesize that glaciers in the Delta River Valley reached their maximum Pleistocene extent during this cold interval because of significant mid-Pleistocene tectonic uplift of the east-central Alaska Range.
Use of a tropical bay in southeastern Brazil by juvenile and subadult Micropogonias furnieri (Perciformes, Sciaenidae)
Authors: da Costa Marcus R , Araújo Francisco G 
Published: July 2003

Abstract
The white croaker Micropogonias furnieri is a commercially important marine fish that uses bays and other semi-closed coastal areas early in its life. A sampling programme, using beach-seine and otter trawl, was carried out in Sepetiba Bay (22°54′–23°04′S, 43°34′–44°10′W), southern Brazil, from October 1998 to September 1999, with the objective of assessing the patterns of temporal and spatial usage of the bay by white croaker during its early life. Early recruits (total length, TL, 10–50 mm) appear off beaches of the inner bay between October and December, move away from them during late summer and early autumn (January–April), and are caught by trawl offshore from May to September at a TL of 70–150 mm. From May to August, new recruits (10–50 mm) are again found inshore. Fish grow from 10–40 to 70–150 mm during the first year of life in the shallows of the bay, before moving offshore. They cross the deeper waters of the bay as they migrate towards the open ocean. Juveniles (TL 70–150 mm) are most abundant in the inner bay, and subadults (TL 150–200 mm) in the outer and central bay. M. furnieri use semi-closed coastal areas as nursery grounds, before moving out over the continental shelf, where they spawn.
Phytoplankton trends in the Baltic Sea
Authors: Wasmund N. , Uhlig S. 
Published: July 2003

Abstract
Monitoring data of phytoplankton abundance and biomass (1979–1999) and Chl. a (1979–2000) from surface samples (0–10 m) of the Kattegat, Belt Sea and Baltic proper were investigated for long-term trends. The Mann–Kendall test as well as the LOESS smoother was applied for three taxonomic groups in spring, summer and autumn separately. Chl. a trends were analysed by linear regression. Downward trends were found for diatoms in spring and summer whereas dinoflagellates generally increased in the Baltic proper but decreased in the Kattegat. In autumn, diatoms increased at some stations. For cyanobacteria, downward trends were detected mainly in the Kattegat/Belt Sea area. Chl. a concentrations showed a general decrease in the Kattegat/Belt Sea area but an increase in the Baltic proper. Observed changes in trends during the two decades might indicate shifts in the ecosystem.
Variability of demographic parameters and population dynamics of Atlantic salmon Salmo salar L. in a south-west French river
Authors: Dumas J. , Prouzet P. 
Published: July 2003

Abstract
The abundance of the salmon population in the Nivelle River was assessed for 11 cohorts during all the stages of their life cycle, from eggs to spawners. A stochastic life history model was used to simulate the changes in numbers at each stage over several years and to evaluate the parameters of a Ricker-type Stock and Recruitment (S–R) relationship. Parameters necessary for managing the exploitation of the species were also estimated. The results indicated that an average deposition of 611 700 eggs (values varying in a proportion of 1 to 3, depending on the year) produced 4870 0+ parr in autumn (variation from 1 to 5.6); 71.8% of which belonged to the group of future 1-year old smolts. The age 1+ parr were eight times less numerous. Survival from egg to 0+ parr was on average 0.97%, but highly variable (varying from 1 to 15). It was density-dependent and followed Ricker S–R model with an optimum of 7800 parr for a survival rate of 3%. During their second year, the survival of 1+ parr reached 53.4% and varied little. The adult runs of complete cohorts amounted to 196 maiden salmon (range, 88 to 382) and previous spawners comprised only 0.9% of adults. Grilse (1 year in the sea) constituted the majority (88.7%). The overall survival rates from 0+ parr to adult returns (6.2% on average) varied three-fold. The majority was females among the grilse (56.2%) and 2-sea-year salmon (88.6%); all 3-sea-year adults were female. Eggs deposited per female averaged 4200, 8500 and 12 750 eggs in each age group, respectively. Simulations of population abundances at various life stages were in good agreement with the observed data. The S–R relationship revealed the low productivity and the vulnerability of this stock, mainly due to the low survival rate of the young during their first year of life. The maximum yield of 12.2% of recruits could be obtained from a deposition of 1 424 000 eggs, which is twice the present average level.
A requiem for the use of 20 log10 Length for acoustic target strength with special reference to deep-sea fishes
Authors: McClatchie S , Macaulay G.J , Coombs R.F 
Published: July 2003

Abstract
Although it is well known that the slopes of target strength (TS) and length relationships vary widely, it is common in fisheries acoustics to force the TS–length regression through a slope of 20. Is it time to abandon this practice? The theoretical justification was that TS should be proportional to cross-sectional area, and that area should scale as the square of the linear dimension (fish length). There are now many species other than gadoids that are the subject of acoustic surveys, and many of them do not have the same morphology as the gadoid fishes. The slope of the TS–length regressions deviates significantly from 20. The empirical slope should be used wherever it can be shown to be more appropriate than the 20 log10 L model. Using the data from swimbladder models, it is shown that Macrourids, a merluccid hake and Oreosomatidae have a different relationship should between swimbladder size and fish size compared with that of gadoids. It is demonstrated that the 20 log10 L model is not appropriate for these deep-water fish and that deviations from the model arise, to a considerable degree, from variation in fish morphotypes. The TS of deep-water Macrourids, a merluccid hake and Oreosomatidae are lower than that of gadoids. This is related to the swimbladder size–fish size relationship in different morphotypes, although not much evidence can be found to support the concept that swimbladder sizes are generally smaller in deep-sea fishes.