bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ultrasound initiated maleic anhydride grafted onto a novel polypropylene copolymer
Authors: Peng Bo , Wu Hong , Bao Wenting , Guo Shaoyun , Chen Yong , Huang Hua , Lai Shih‐Yaw , Jow Jinder 
Published: December 2011

AbstractThe reaction of maleic anhydride (MAH) grafted onto propylene‐based copolymer (DP) without adding any initiator was conducted through ultrasound assisted extrusion in this article. The effects of ultrasound power, die temperature, and MAH content on the grafting degree and efficiency were studied. With increasing ultrasound power, the grafting degree and efficiency of DP‐g‐MAH increase. The presence of ultrasound with higher power and lower die temperature is beneficial to increase the grafting degree and efficiency. The increase of MAH content can increase the grafting degree but reduce the grafting efficiency. Based on the results of melt flow index, dynamical rheological, gel permeation chromatograph (GPC), and Fourier transform infrared spectroscopy (FTIR) tests, the mechanisms of the grafting reaction were proposed. POLYM. ENG. SCI., 2012. © 2011 Society of Plastics Engineers
The role of filler network in nonlinear viscoelastic behavior of vapor grown carbon nanofiber filled polystyrene: A strain dependent rheological behavior and electrical conductivity study
Authors: Zhao Li , Yang Hongmei , Song Yihu , Tan Yeqiang , Hu Guo‐Hua , Zheng Qiang 
Published: December 2011

AbstractInfluence of filler network on Payne effect and modulus recovery for vapor grown carbon nanofiber (VGCF)/polystyrene (PS) composites with VGCF content above electrical percolation threshold was studied by using simultaneous measurements of viscoelasticity and electrical conductivity. The strain softening seems to be closely related to breakdown of filler network. Recovery tests of modulus and electrical conductivity by means of time sweep indicate that the reformation of deformed VGCF network structure could not be completed in several hours. Compared with recovery behavior of carbon black (CB) and silica (SiO2) network, the reformation of VGCF network appears more difficult. Moreover, solidification of composites exerts some effect on modulus recovery. The filler network disrupted by small strain can be perfectly recovered by matrix solidification while the initial filler structure collapsing at large strain is only partially restored. POLYM. ENG. SCI., 2012. © 2011 Society of Plastics Engineers
Water spray cooling of polymers
Authors: Tan S.B. , Hornsby P.R. , McAfee M.B. , Kearns M.P. , McCourt M.P. 
Published: December 2011

AbstractThe cooling process in conventional rotomolding is relatively long due to poor thermal conductivity of plastics. The lack of internal cooling is a major limitation although rapid external cooling is possible. Various internal cooling methodologies have been studied to reduce the cycle time. These include the use of compressed air, cryogenic liquid nitrogen, chilled water coils, and cryogenic liquid carbon dioxide, all of which have limitations. However, this article demonstrates the use of water spray cooling of polymers as a viable and effective method for internal cooling in rotomolding. To this end, hydraulic, pneumatic, and ultrasonic nozzles were applied and evaluated using a specially constructed test rig to assess their efficiency. The effects of nozzle type and different parametric settings on water droplet size, velocity, and mass flow rate were analyzed and their influence on cooling rate, surface quality, and morphology of polymer exposed to spray cooling were characterized. The pneumatic nozzle provided highest average cooling rate while the hydraulic nozzle gave lowest average cooling rate. The ultrasonic nozzle with medium droplet size traveling at low velocity produced satisfactory surface finish. Water spray cooling produced smaller spherulites compared to ambient cooling whilst increasing the cooling rate decreases the percentage crystallinity. POLYM. ENG. SCI., 2012. © 2011 Society of Plastics Engineers
A novel method for preparing nanoparticle‐coated additives used in polypropylene composites
Authors: Qian Zheng , Wang Peng , Gogos Costas G. 
Published: December 2011

AbstractA novel simultaneous, in situ milling and coating method carried out in a fluid energy mill (FEM) is applied for the first time to prepare nanoparticle‐coated CaCO3 (CC) additives for polymer composite materials. Simply milled (without coating) CC particles and as‐received CC particles were used as references for comparison. The effects of the grinding pressure and the fraction of the nanoparticles on the size and flowability of CC particles were studied. The composites made with polypropylene (PP) and this specially prepared CC have higher elongation at break, elastic modulus, and impact strength, compared with the PP filled with uncoated CC. The thermal and thermo‐oxidative stabilities of PP are improved as well by introducing the milled and nanoparticle‐coated CC. POLYM. ENG. SCI., 2012. © 2011 Society of Plastics Engineers
Improved photochromic and fatigue performance of (E)‐dicyclopropylmethylene‐(2,5‐dimethyl‐3‐furylethylidene)‐succinicanhydride doped in polyurethane thin film
Authors: Asiri Abdullah Mohamed 
Published: December 2011

AbstractImproved photochromic properties and fatigue performance of (E)‐dicyclopropylmethylene‐(2,5‐dimethyl‐3‐furylethylidene)‐succinicanhydride doped in polyurethane thin film were discussed in this study. Fulgide 1‐E doped in polyurethane polymer films was heated at various annealing temperatures. Upon irradiation with UV light (366 nm), fulgide 1‐E undergoes a conrotatory ring closure to the pink‐colored closed form 1‐C. The latter color was switched back to the original color when the films were irradiated with white light. The kinetics of photocoloration and photobleaching processes was followed spectrophotometrically by monitoring the absorbance of the ring‐closed product 1‐C at its λmax of 525 nm. The first‐order plots of photocoloration reaction show distinct linear line and the slope of which corresponding to the first‐order rate constants k. It was found that for photocoloration reaction, the rate constant of the photocoloration reaction is slower than the photobleaching reaction, and both reactions decrease with increasing the annealing temperatures. It was found that there was almost complete loss of photochemical fatigue resistance of fulgide 1 doped in polyurethane polymer film irrespective of the annealing temperature. POLYM. ENG. SCI., 2012. © 2011 Society of Plastics Engineers
Uniaxial compression and combined compression‐and‐shear response of amorphous polycarbonate at high loading rates
Authors: Prakash Vikas , Mehta Namit 
Published: December 2011

AbstractWe present results of a study conducted to better understand the yield and flow response of amorphous poly(bisphenol A carbonate), PC‐Lexan® (PC), under uniaxial compression and combined compression‐and‐shear impact loading. A split Hopkinson pressure bar (SHPB) is utilized to obtain nearly adiabatic uniaxial compression response of the PC in the strain‐rate range of 1000–2000 s−1. Since temperature is expected to play an important role in governing the dynamic response of PC, nearly isothermal SHPB tests are also conducted and compared with the adiabatic response. In order to investigate the coupling of shear behavior and dilatation in PC at high loading rates, combined compression‐and‐shear plate impact experiments are conducted at strain‐rates in the range of 105–106 s−1. In addition, novel plate impact experiments are conducted to better understand the evolution of the shearing resistance of PC in response to sudden alterations (drop) in hydrostatic pressure under extremely high shearing rates. POLYM. ENG. SCI., 2012. © 2011 Society of Plastics Engineers
Theoretical studies of ground and excited electronic states in a series of heteroleptic iridium complexes using density functional theory
Authors: Su Yan , Kang Li‐Hua 
Published: December 2011

AbstractA series of new heteroleptic iridium(III) complexes [Ir(C⁁N)2(N⁁N)]PF6 (1‐6) (each with two cyclometalating C⁁N ligands and one neutral N⁁N ancillary ligand, where C⁁N = 2‐phenylpyridine (ppy), 5‐methyl‐2‐(4‐fluoro)phenylpyridine (F‐mppy), and N⁁N = 2,2′‐dipyridyl (bpy), 1,10‐phenanthroline (phen), 4,4′‐diphenyl‐2,2′‐dipyridy (dphphen) were found to have rich photophysical properties. Theoretical calculations are employed for studying the photophysical and electrochemical properties. All complexes are investigated using density functional theory. Excited singlet and triplet states are examined using time‐dependent density functional theory. The low‐lying excited‐state geometries are optimized at the ab initio configuration interaction singles level. Then, the excited‐state properties are investigated in detail, including absorption and emission properties, photoactivation processes. The excited state of complexes is complicated and contains triplet metal‐to‐ligand charge transfer, triplet ligand‐to‐ligand charge transfer simultaneously. Importantly, the absorption spectra and emission maxima can be tuned significantly by changing the N⁁N ligands and C⁁N ligands. © 2011 Wiley Periodicals, Inc. Int J Quantum Chem, 2012
The distribution of height and diameter in random non‐plane binary trees
Authors: Broutin Nicolas , Flajolet Philippe 
Published: December 2011

AbstractThis study is dedicated to precise distributional analyses of the height of non‐plane unlabelled binary trees (“Otter trees”), when trees of a given size are taken with equal likelihood. The height of a rooted tree of size n is proved to admit a limiting theta distribution, both in a central and local sense, and obey moderate as well as large deviations estimates. The approximations obtained for height also yield the limiting distribution of the diameter of unrooted trees. The proofs rely on a precise analysis, in the complex plane and near singularities, of generating functions associated with trees of bounded height. © 2011 Wiley Periodicals, Inc. Random Struct. Alg., 2012
Model of Blast Furnace Hearth Drainage
Authors: Shao Lei , Saxén Henrik 
Published: December 2011

AbstractThe hearth plays an important role in the operation of the ironmaking blast furnace (BF). A simplified simulation model of the hearth based on the general principles of liquid drainage has been extended to make the model more practical and comprehensive. The tap rates of the liquids are determined by production and taphole conditions, including taphole diameter and length, and the tap‐end conditions are iteratively calculated to yield a quasi‐stationary tap cycle. The model, which considers both a sitting and a (partially) floating dead man, is illustrated with the use of a set of examples, where the effect of variables on the drainage behavior is studied. The model is finally validated by applying it to short‐term data from an industrial BF.
Metastatic disease to the pancreas: an imaging challenge
Authors: Triantopoulou Charikleia , Kolliakou E. , Karoumpalis I. , Yarmenitis S. , Dervenis C. 
Published: December 2011

Abstract
Metastatic lesions of the pancreas are uncommon, accounting for approximately 2% of pancreatic malignancies. Many tumours involve the pancreas secondarily and may manifest with different clinical and imaging characteristics. Although many patients have widespread disease, isolated metastases can be found. Surgical management is associated with improved survival in these cases. The experience of the pancreatic surgery unit and imaging department of our hospital in many patients presenting with pancreatic metastases is presented, and a review of the recent literature is undertaken.

Main Messages

• The early recognition of secondary pancreatic tumours on US, CT and MRI is extremely important.

• Pancreatic metastases may mimic primary pancreatic adenocarcinoma or induce acute pancreatitis.

• Most pancreatic metastases are discovered on a CT examination performed for follow-up.
The Late Triassic Kataev volcanoplutonic association in western Transbaikalia, a fragment of the active continental margin of the Mongol-Okhotsk Ocean
Authors: Donskaya T.V. , Gladkochub D.P. , Mazukabzov A.M. , De Waele B. , Presnyakov S.L. 
Published: December 2011

Abstract
The Kataev volcanoplutonic association has been recognized in western Transbaikalia. It unites the volcanosedimentary rocks of the Kataev Formation and associated granites localized within the lower plates of the Buteel-Nuur and Zagan metamorphic-core complexes. The rocks of the Kataev association are dynamometamorphosed to different degrees, which is due to the tectonic exposure of metamorphic-core complexes in the Early Cretaceous. The U-Pb zircon dating of the Kataev Formation rhyolites yielded an age of 226 ± 3 Ma. The U-Pb zircon age of the granites intruding the Kataev Formation rocks is 223.4 ± 5.0 Ma. The volcanics of the Kataev Formation belong to the subalkalic basalt-andesite-dacite-rhyolite series. The trachybasalts and trachyandesite-basalts of the Kataev Formation have geochemical characteristics of igneous rocks formed as a result of subduction, e.g., they show distinct negative Nb and Ti and positive Ba and Sr anomalies on multielemental patterns. The specific composition of mafic volcanics points to their formation through the melting of a mantle source resulted from the mixing of depleted mantle and subduction components. Trachyandesites have higher Th and U contents than basaltoids. They can result from the contamination of a mantle source, similar in composition to the Kataev Formation basaltoids, with crustal material. The felsic volcanics of the Kataev Formation and granites intruding them show nearly identical geochemical characteristics corresponding to both A-and I-type granites. These rocks might have formed through the melting of a moderately water-saturated magmatic source of diorite-tonalite composition at 742–833°C. We have established that the rocks of the Kataev volcanoplutonic association in western Transbaikalia and Northern Mongolia formed in the Late Triassic synchronously with the calc-alkaline granitoids of the Henteyn–Daurian batholith and the alkali granites and bimodal volcanic associations of the Kharitonovo and Tsagaan-Hurtey volcanoplutonic associations. The synchronous formation of volcanoplutonic associations of normal and high alkalinity agrees with the geodynamic setting of the Andean-type active continental margin existing in the area of present-day western Transbaikalia and Northern Mongolia in the Early Mesozoic. This setting was the result of the subduction of the Mongol-Okhotsk oceanic plate beneath the Siberian continent.
Cambrian paleomagnetism in the Bateni Ridge: evolution of the Kuznetsk Alatau island arc (southern Siberia)
Authors: Metelkin D.V. , Koz’min D.G. 
Published: December 2011

Abstract
We present paleomagnetic data on the Cambrian volcanosedimentary complexes of the Bateni Ridge, which correspond to the evolution of the Kuznetsk Alatau island arc. The paleomagnetic poles which served as the basis for the apparent polar-wander path (APWP) were determined. The paleomagnetic data were compared with those on the Cambrian poles for other fragments of the Kuznetsk Alatau island arc. For example, the APWP of the Bateni fragment corresponds to that of the Kiya (Martaiga) fragment of the eastern slope of the Kuznetsk Alatau. The distribution of the paleomagnetic poles suggests that the relative drift of the Kuznetsk Alatau arc fragments and the entire island arc system resulted from large-amplitude strike-slips. In the Cambrian, this paleoarc moved from ∼10° N to ∼10° S and rotated more than 50° clockwise. In the paleomagnetic record, its accretion is reflected in the coincidence of the Late Cambrian–Early Ordovician poles on the eastern slope of the Kuznetsk Alatau with one another and the coeval poles for the Siberian craton. This coincidence also suggests that the general structure of the present Kuznetsk Alatàu formed as early as the Early Caledonian. Nevertheless, the differences in the position of the poles on the western and eastern slopes of the Kuznetsk Alatau suggest that strike-slip activity along the Kuznetsk–Altai deep fault (the major one in the region) continued in the Late Paleozoic and, probably, in the Mesozoic.
Subject States and Tribute Provinces: The Aztec Empire in the Northern Valley of Mexico
Authors: Hicks Frederic 
Published: December 2011

AbstractThe Aztec empire was composed of at least two kinds of entities, subject states and tribute provinces, and these were administered through at least two separate hierarchies. Imperial tribute, which was extracted from the common people, was not delivered through the same channels as those through which subject rulers interacted with their imperial overlords. This arrangement enabled the latter to deal with the subject rulers not as tribute-givers, but as allies and colleagues, while extracting a heavy tribute from their commoner subjects. In the core area of the Aztec empire, which included the northern Valley of Mexico, the boundaries of the subject states and tribute provinces did not coincide, and this contributed to the economic and political integration of the core area. The tribute provinces consisted only of those communities within a region that gave tribute to the empire, and the elimination of such obligations after the Spanish conquest effectively liquidated the tribute provinces.
Prehistoric Political Change on the Southeast Mesoamerican Periphery
Authors: Dixon Boyd 
Published: December 2011

AbstractRecent archaeological settlement pattern research in the 550 sq km Comayagua Valley in central Honduras has documented considerable variation in the political structure of one ranked society over a 2,500-year period of prehistory. Data presented suggest that this Lenca and proto-Lenca culture group underwent at least five major political restructurings during this time as a response to the local, regional, and interregional political climate on the southeast Mesoamerican periphery. Such variability calls into question traditional models postulating a lack of complexity or adaptive flexibility for indigenous cultures of lower Central America.
Continuity and Change in a Royal Maya Residential Complex at Copan
Authors: Andrews V E. Wyllys , Fash Barbara W. 
Published: December 2011

AbstractExcavation of the large elite structures around the Structure 10L-32 plaza at the northeast corner of Group 10L-2, at the south edge of the Acropolis at Copan, supports the view that this group was the residence of the royal family during the Late and Terminal Classic Coner phase. During the hundred years of construction at the uppermost plaza level, structure change and growth follows two patterns: (1) a tendency for subsequent buildings in one place to retain a similar form and probably function, and (2) a trend away from domestic structures to ritual or public buildings. As the buildings around the plaza grew, access to the complex was increasingly limited. The largest two, Structures 10L-32 and 10L-30, were built late in the eighth century by a noble named Chac, who was a close associate, relative, or sibling of Yax Pac. The older Structure 10L-29, on the terrace above the plaza, was dedicated to the worship of royal lineage ancestors. The collapse of this group occurred in two stages, a decline of the nobility early in the ninth century, followed by violent destruction of buildings and monuments sometime before that century ended. This sequence of events may apply to the entire Principal Group and adjacent elite residential areas.
The Hieroglyphic Stairway and its Ancestors:Investigations of Copan Structure 10L-26
Authors: Fash William L. , Williamson Richard V. , Larios Carlos Rudy , Palka Joel 
Published: December 2011

AbstractThe investigation of Structure 10L-26 has revealed a series of sequent monumental constructions underlying the elaborate final phase temple/pyramid made famous by the Maya area's largest hieroglyphic stairway. The meticulous recording and analysis of the archaeological, architectural, hieroglyphic, and iconographic materials from this sequence of sculpture-adorned buildings provides the opportunity for a diachronic view of the nature of the historical record and political symbolism. Investigations conducted to date provide hieroglyphic and archaeological evidence in support of the sequence of rulers documented in the official histories of the last four rulers of Copan, and evidence of a dramatic shift in the use of this space, and of political symbolism in general, by the fifteenth king, Smoke Shell. While the lack of evidence for “re-writing of history” will be encouraging to many, the evidence also shows the need for a careful assessment of official histories by archaeological excavations. Just as important, the Copan Acropolis research demonstrates the usefulness of incorporating ideas and data derived from the careful scrutiny of the public monuments in ongoing archaeological investigations and model building.
The Founders of Lineages at Copan and other Maya Sites
Authors: Schele Linda 
Published: December 2011

AbstractDecipherments and interpretations presented by Peter Mathews and Bertold Riese a decade ago led to the identification of numbered-successor titles that list individual rulers according to their numerical position in a historical succession of kings. Work on the inscriptions of Copan has shown that the “counts of successors” there began with a single founding ancestor, who has been identified archaeologically. Since the rulers of other kingdoms calculated their descent from different founding ancestors, the evidence suggests that Maya kingdoms were ruled by lineages or dynasties of males who calculated their descent for a single anchoring ancestor, who was very probably a historical individual. Evidence from Naranjo also suggests that alternative descent lines were calculated from supernatural anchoring ancestors. The metaphorical term for these lineages was “spout-tree-house.” All of the people in the lineage descending from these founders were called “sprouts,” while the ruling patriarch was the ahau of the descent line.
PILGRIMAGES AND PERSISTENT SOCIAL MEMORY IN SPITE OF VOLCANIC DISASTERS IN THE ARENAL AREA, COSTA RICA
Authors: Sheets Payson 
Published: December 2011

AbstractAncient Costa Ricans in the Arenal area exhibited extraordinary persistence in landscape use and social memory, in spite of repeated catastrophes caused by explosive volcanic eruptions. The Cañales village on the south shore of Lake Arenal was struck by two large explosive eruptions during the Arenal phase (500b.c.–a.d.600). Following ecological recovery, the village was reoccupied after each of these eruptions. I argue that the people who reoccupied the village were direct descendants of pre-disaster villagers due to the fact that they reinstated use of the same path to the village cemetery. While previous interpretations emphasized ecological reasons for village reoccupation, I suggest that a dominating reason for reoccupation was to re-establish contact with the spirits of deceased ancestors in the cemetery. The living and the spirits of the deceased constituted the functioning community. The refugees re-established processional access to their cemetery as soon as possible, perhaps even before the village was reoccupied. Archaeologists rarely discover evidence of ancient pilgrimages. However, the combination of remote sensing and detailed stratigraphic analyses allow them to be detected in the Arenal area. Villagers created and perpetuated social memory by regular linear ritual processions along precisely the same path, in spite of challenging topography and occasional regional disasters obscuring the path. This recognition has implications for the arguments of sedentism versus residential mobility during the Arenal phase.