bluuebunny/crossref_metadata_2025_split huggingface dataset:
Part Load Performance and Emission Improvement of Direct Injection Diesel Engine through Porous Medium Combustion Technique
Authors: Kannan Chidambaram , Tamilporai Packirisamy 
Published: October 2009

AbstractDiesel engines are being extensively used in the transport sector owing to their excellent fuel efficiency, low emissions of carbon dioxide, unburned hydrocarbons and carbon monoxide. However, high emissions of nitrogen oxides (NOx) and particulate matter (PM) place diesel engines on the down side. It is extremely complex to reduce both emissions at the same time, because of the trade‐off between NOx and PM emissions. Even though the implementation of high pressure injection and common rail system could reduce both NOx and PM emissions together, the cost involved would be high and unaffordable for many engine producers and consumers. In this research work, a new combustion technique termed, porous medium combustion, has been proven to be a proficient technique in reducing both NOx and PM emissions from the direct injection diesel engines. However, the NOx and PM emissions were found to be higher than the conventional engine at low range of part loads.
Removal of Chromium from Synthetic Effluent using Nymphaea rubra
Authors: Taj Rafi Yasmin , Renganathan Sahaderan , Partha Nagarajan , Baskar Gurunathan , Velan Manikom 
Published: October 2009

AbstractIn the present work, biosorption of Cr(VI) by Nymphaea rubra was investigated in batch studies. Batch experiments were conducted to study the effect of initial sorbent dosage, solution pH and initial Cr(VI) concentration. The results showed that the equilibrium uptake capacity was increased with decrease in biomass dosage. The Cr(VI) removal was influenced by the initial chromium compound concentration. Langmuir and Freundlich adsorption isotherm models were used to represent the equilibrium data. The Freundlich isotherm model was fitted very well with the equilibrium data when compared to Langmuir isotherm model. The sorption results were analyzed for pseudo‐first order and pseudo‐second order kinetic model. It was observed that the kinetic data fitted very well with the pseudo‐second order rate equation when compared to the pseudo‐first order rate equation. Fourier transform infrared spectrum showed the presence of different functional groups in the biomass. The surface morphology of the sorbent was exemplified by SEM analysis. Aquatic weeds seem to be a promising biosorbent for the removal of chromium ions from water environment. This paper reports the research findings of a laboratory‐based study on the removal of Cr(VI) from the synthetic solution using the dried stem of N. rubra as a biosorbent.
Degradation of Monoazo Pigments Red 53:1 and Red 48:2 by Fenton, Photo‐Fenton and UV/Peroxide Reactions
Authors: Ilha Clóvis E. G. , dos Santos Antônio J. M. G. , SouzaDe Jurandir R. 
Published: October 2009

AbstractThe degradation reactions of two monoazo pigments, namely, Red 53:1 and Red 48:2, by Fenton, photo‐Fenton and UV/H2O2 systems have been studied. The efficiencies of the Fenton reactions increased with temperature, but the formation of solid agglomerates was observed when the reactions were carried out above 50°C indicating a coagulant action of Fe+2 or Fe+3. Photo‐Fenton reactions irradiated by sunlight presented the best rate constants for cleavage of the azo bond and the naphthalene rings. The UV/H2O2 system exhibited the highest efficiency with respect to the consumption of H2O2. The presence of a carbonyl group in the ortho position of the naphthol ring hampered the oxidation of pigment Red 48:2 by hydroxyl radicals. This finding may be explained in terms of the acceptor character of the COOH group, and suggests the formation of a complex containing two six‐membered rings between Fe+3 and the pigment molecule.
Determination of Polycyclic Aromatic Hydrocarbons in Soil by Miniaturized Ultrasonic Extraction and Gas Chromatography‐Mass Selective Detection
Authors: Ozcan Senar , Tor Ali , Aydin Mehmet Emin 
Published: October 2009

AbstractA miniaturized ultrasonic extraction procedure was developed for the determination of polycyclic aromatic hydrocarbons (PAHs) in soil by gas chromatography‐mass spectrometry. After determination of the most suitable extraction solvent with 5 min sonication time, several other parameters (sample amount, solvent volume and number of extraction times) were optimized using a 23 factorial experimental design. Recoveries of PAHs from spiked soil samples were over 90% for three different fortification levels between 50 and 300 μg/kg, and relative standard deviations of the recoveries were in the range of < 1–15%. The limits of detection ranged from 0.002 to 1.87 μg/kg. The performance of the developed procedure was also compared with other traditional Soxhlet, shake flask and large scale ultrasonic extraction procedures on real soil samples, and extraction methods showed comparable efficiencies. The proposed procedure required small volumes of solvent and sample. It was practicable, rapid and easy to use for analysis of PAHs in soils.
Conformations of Entangled Semiflexible Polymers: Entropic Trapping and Transient Non‐Equilibrium Distributions
Authors: Hinsch Hauke , Frey Erwin 
Published: October 2009

AbstractThe tube model is a central concept in polymer physics, and allows one to reduce the complex many‐filament problem of an entangled polymer solution to a single‐filament description. We investigate the probability distribution function of conformations of confinement tubes and single encaged filaments in entangled semiflexible polymer solutions. Computer simulations are developed that mimic the actual dynamics of confined polymers in disordered systems with topological constraints on time scales above local equilibration, but well below large‐scale rearrangement of the network. We observe the statistical distribution of curvatures and compare our results to recent experimental findings. Unexpectedly, the observed distributions show distinctive differences from free polymers even in the absence of excluded volume. Extensive simulations permit to attribute these features to entropic trapping in network void spaces. The transient non‐equilibrium distributions are shown to be a generic feature in quenched‐disorder systems on intermediate time scales.
Diffusion of Circular DNA in Two‐Dimensional Cavity Arrays
Authors: Nykypanchuk Dmytro , Hoagland David A. , Strey Helmut H. 
Published: October 2009

AbstractThrough a two‐dimensional cavity array with connecting pores of submolecular size, diffusion of relaxed circular and linear DNA molecules is visualized by fluorescence microscopy. Across the entropic barriers transport regime, associated with spatially heterogeneous confinement of flexible polymers, circular DNA diffuses slower than linear DNA of the same length, a trend indicating that linear DNA preferably moves through connecting pores by the threading of an end rather than the looping of a midsection.
Automated quality assessment of autonomously acquired microscopic images of fluorescently stained bacteria
Authors: Zeder M. , Kohler E. , Pernthaler J. 
Published: October 2009

AbstractQuality assessment of autonomously acquired microscopic images is an important issue in high‐throughput imaging systems. For example, the presence of low quality images (≥10%) in a dataset significantly influences the counting precision of fluorescently stained bacterial cells. We present an approach based on an artificial neural network (ANN) to assess the quality of such images. Spatially invariant estimators were extracted as ANN input data from subdivided images by low level image processing. Different ANN designs were compared and >400 ANNs were trained and tested on a set of 25,000 manually classified images. The optimal ANN featured a correct identification rate of 94% (3% false positives, 3% false negatives) and could process about 10 images per second. We compared its performance with the image quality assessment by different humans and discuss the difficulties in assigning images to the correct quality class. The computer program and the documented source code (VB.NET) are provided under General Public Licence. © 2009 International Society for Advancement of Cytometry
1,1′‐Binaphthyl‐2‐methylpyridinium‐Based Peroxophosphotungstate Salts: Synthesis, Characterization, and Their Use as Oxidation Catalysts
Authors: Jahier Claire , Felpin François‐Xavier , Méliet Catherine , Agbossou‐Niedercorn Francine , Hierso Jean‐Cyrille , Nlate Sylvain 
Published: October 2009

AbstractA series of 1,1′‐binaphthyl‐2‐methylammonium and pyridinium salts 6, 7, and 8 was synthesized through the coupling reaction of 2‐(bromomethyl)‐1,1′‐binaphthalene (5) with the dendritic tetraallyl pyridinedicarbinol dendron 2 as well as triethylamine and 4‐tert‐butylpyridine. Tetraallyl pyridinedicarbinol dendron 2 was prepared by allylation of commercially available diethyl pyridine‐3,5‐dicarboxylate (1). The allylation of 2 with allyltrimethylsilane in the presence of boron trifluoride was unsuccessful, as tetraallyl pyridinedicarbinol trifluoroboron adduct 3 was obtained instead of expected hexaallylpyridine compound 4. The catalytic hydrogenation of allyl groups of the ammonium salt of 2, namely, tetraallyl 1,1′‐binaphthyl‐2‐methylpyridinium salt 6, successfully led to the corresponding tetra‐n‐propyl 1,1′‐binaphthyl‐2‐methylpyridinium salt 9. The reaction between salts 7, 8, and 9 and the heteropolyacid H3PW12O40 in the presence of a large excess of hydrogen peroxide afforded the corresponding 1,1′‐binaphthyl‐2‐methylammonium‐based polyoxometalate salts 10, 11, and 12, which contain a catalytically active trianionic [H3PW12O40]3– in the core. These binaphthyl–POM salts are soluble in commonly used organic solvents, and their IR and 31P NMR spectroscopic and elemental analysis data indicate the presence of the POM unit in the frameworks. These POM hybrids are efficient, recoverable, and reusable catalysts in the oxidation of thioanisole, cyclooctene, and cyclohexanol, with H2O2 as the oxidant. A study of the countercation effects indicated that the reaction kinetics and the selectivity are sensitive to the structure of the cation. Two cycles of catalytic reactions were performed without a discernible loss in activity. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Carboxylato‐Modified New Oxo‐Centred Triruthenium Cluster Compounds with CO and Solvent Ligands: The X‐ray Structure of [Ru3O(C2H5CO2)6(CO)(THF)2]
Authors: Inatomi Atsushi , Abe Masaaki , Hisaeda Yoshio 
Published: October 2009

AbstractNew synthetic precursors for CO‐coordinated, oxo‐centred triruthenium(II,III,III) complexes with varied carboxylato groups [Ru3O(RCO2)6(CO)(solvent)2] where R = C2H5, CH3 and C6H5 have been prepared and characterised. Among the series, the propionato‐bridged complex [Ru3O(C2H5CO2)6(CO)(THF)2] (1) was structurally determined by single‐crystal X‐ray crystallography. Cyclic voltammetry revealed thatthe benzoato‐bridged complex [Ru3O(C6H5CO2)6(CO)(C2H5OH)2] in 0.1 mol dm–3 nBu4NPF6/DMF undergoes two consecutive one‐electron processes assignable to the redox of the Ru3(μ3‐O) core, the redox potentials of which are highly dependent on the electron‐donating/accepting nature of the carboxylato groups. UV‐light excitation of the compounds in CH3CN resulted in the dissociation of CO to form the tris(CH3CN) compounds [Ru3O(RCO2)6(CH3CN)3] (R = C2H5, CH3 and C6H5). These compounds are highly useful as synthetic precursors to a wide range of μ3‐oxo‐triruthenium derivatives with well‐defined redox responses. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Contiguous multi‐proxy analyses (X‐radiography, diatom, pollen, and microcharcoal) of Holocene archaeological features at Kuk Swamp, Upper Wahgi Valley, Papua New Guinea
Authors: Denham Tim , Sniderman Kale , Saunders Krystyna M. , Winsborough Barbara , Pierret Alain 
Published: October 2009

AbstractContiguous multi‐proxy analyses (X‐radiography, diatom, pollen, and microcharcoal) have been conducted on the fills of early, mid‐, and mid‐late Holocene features at Kuk Swamp, Upper Wahgi Valley, Papua New Guinea. The features are associated with key periods of archaeological interest: plant exploitation (ca. 10,000 cal yr B.P.), earliest cultivation (6950–6440 cal yr B.P.), and earliest ditches (ca. 4000 cal yr B.P.). The analyses are designed to clarify uncertainties regarding the reliability and association of different samples within feature fills for the interpretation of human activities on the wetland in the past. Methodologically, these investigations have clarified site formation processes, including pedogenesis within feature fills, which enable a better determination of archaeological associations for different samples within those fills. Substantively, the results provide higher resolution interpretations of paleoenvironments and past human activities on the wetland margin. © 2009 Wiley Periodicals, Inc.
Rockshelter sedimentation in a dynamic tropical landscape: Late Pleistocene–Early Holocene archaeological deposits in Kitulgala Beli‐lena, southwestern Sri Lanka
Authors: Kourampas Nikos , Simpson Ian A. , Perera Nimal , Deraniyagala Siran U. , Wijeyapala W.H. 
Published: October 2009

AbstractKitulgala Beli‐lena, a rockshelter in gneiss in humid tropical southwestern Sri Lanka, was inhabited by Late Pleistocene–Early Holocene (>31,000–7880 B.P.) hunter‐gatherers who made geometric microliths and exploited rainforest resources. Micromorphological analysis of a ca. 3‐m‐thick succession of diamictic loams, clays, and breccia with cultural content suggests that relative contribution of episodic colluviation and roof fall, water seepage through joints and diverse human activity varied through time. Facies changes across the profile reflect monsoon weakening ca. 20,000–16,000 cal B.P. and abrupt intensification ca. 15,700 cal B.P., on the wane of the global Last Glacial Maximum (LGM). Post‐depositional modification included clay, sesquioxide, and minor phosphate translocation; termite and other arthropod bioturbation; and clast weathering on the rockshelter floor. Human input (tools and tool‐making refuse, reworked charcoal and associated combustion by‐products) is markedly higher in sediments younger than ca. 15,700 cal B.P., suggesting intensification of site use immediately after the LGM. © 2009 Wiley Periodicals, Inc.
Geomorphological evolution of the River Loukkos estuary around the Phoenician city of Lixus on the Atlantic Littoral of Morocco
Authors: Carmona Pilar , Ruiz José Miguel 
Published: October 2009

AbstractThe ancient city of Lixus, today situated on a hill on the right bank of the River Loukkos, 4km from the coast, was founded on the shore of a brackish lagoon that was sheltered from Atlantic storms. This geographical context provided the city with one of the best Phoenician harbors and abundant fishing resources, and allowed access to the Gharb cattle farming resources and cereal production systems. In this study, the historical evolution of the Loukkos estuarine environment is reconstructed through geomorphological and sedimentological analyses, combined with cartographic, archaeological, and geographical data. The outcomes reveal the progressive infilling of the estuarine lagoon of Lixus and its transformation into the current estuary and floodplain. The recent history of this estuary records four successive stages: (1) an initial stage associated with the maximum Holocene marine transgression (5500 to 5320 cal. yr B.P.) that reached the interior of the estuary; (2) a sheltered brackish tidal lagoon stage in Phoenician and Roman times; (3) a period of progressive infilling of the estuarine lagoon, from late Roman times to the Middle Ages (11th to15th centuries); (4) a period of rapid expansion of intertidal marshes (17th to 19th centuries) that saw the formation of the modern estuarine plain and meandering channel system (20th century). © 2009 Wiley Periodicals, Inc.
Anthropometric measures and epithelial ovarian cancer risk in the European Prospective Investigation into Cancer and Nutrition
Authors: Lahmann Petra H. , Cust Anne E. , Friedenreich Christine M. , Schulz Mandy , Lukanova Annekatrin , Kaaks Rudolf , Lundin Eva , Tjønneland Anne , Halkjær Jytte , Severinsen Marianne Tang , Overvad Kim , Fournier Agnès , Chabbert‐Buffet Nathalie , Clavel‐Chapelon Françoise , Dossus Laure , Pischon Tobias , Boeing Heiner , Trichopoulou Antonia , Lagiou Pagona , Naska Androniki , Palli Domenico , Grioni Sara , Mattiello Amalia , Tumino Rosario , Sacerdote Carlotta , Redondo María‐Luisa , Jakszyn Paula , Sánchez María‐José , Tormo María‐José , Ardanaz Eva , Arriola Larraitz , Manjer Jonas , Jirström Karin , Bueno‐de‐Mesquita H. Bas , May Anne M. , Peeters Petra H.M. , Onland‐Moret N. Charlotte , Bingham Sheila , Khaw Kay‐Tee , Allen Naomi E. , Spencer Elizabeth , Rinaldi Sabina , Slimani Nadia , Chajes Véronique , Michaud Dominique , Norat Teresa , Riboli Elio 
Published: October 2009

AbstractWe examined the associations of measured anthropometric factors, including general and central adiposity and height, with ovarian cancer risk. We also investigated these associations by menopausal status and for specific histological subtypes. Among 226,798 women in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort, there were 611 incident cases of primary, malignant, epithelial ovarian cancer diagnosed during a mean 8.9 years of follow‐up. Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs), adjusted for potential confounders. Compared to women with body mass index (BMI) < 25 kg/m2, obesity (BMI ≥ 30 kg/m2) was associated with excess ovarian cancer risk for all women combined (HR = 1.33, 95% CI = 1.05–1.68; ptrend = 0.02) and postmenopausal women (HR = 1.59, 95% CI = 1.20–2.10; ptrend = 0.001), but the association was weaker for premenopausal women (HR = 1.16, 95% CI = 0.65–2.06; ptrend = 0.65). Neither height or weight gain, nor BMI‐adjusted measures of fat distribution assessed by waist circumference, waist–hip ratio (WHR) or hip circumference were associated with overall risk. WHR was related to increased risk of mucinous tumors (BMI‐adjusted HR per 0.05 unit increment = 1.17, 95% CI = 1.00–1.38). For all women combined, no other significant associations with risk were observed for specific histological subtypes. This large, prospective study provides evidence that obesity is an important modifiable risk factor for epithelial ovarian cancer, particularly among postmenopausal women.
CXCR4 and CXCR7 regulate angiogenesis and CT26.WT tumor growth independent from SDF‐1
Authors: Kollmar Otto , Rupertus Kathrin , Scheuer Claudia , Nickels Ruth M. , Haberl Gudrun C.Y. , Tilton Bettina , Menger Michael D. , Schilling Martin K. 
Published: October 2009

AbstractRecent studies have shown that the chemokine stromal cell‐derived factor (SDF)‐1 and its receptor CXCR4 are involved in the metastatic process of colorectal cancer. The impact of SDF‐1 on the stimulated metastatic growth during hepatectomy‐associated liver regeneration is unknown. With the use of a heterotopic murine colon cancer model, we analyzed whether blockade of SDF‐1 inhibits angiogenesis and extrahepatic growth of colorectal cancer after liver resection. Functional neutralization of SDF‐1 by 1 mg/kg body weight anti‐SDF‐1 antibody only slightly delayed the initial tumor cell engraftment but also did not reduce the size of established extrahepatic tumors compared with controls. Tumor cell apoptosis was increased by anti‐SDF‐1 treatment only during the early 5–9‐day period of tumor cell engraftment, but was found significantly decreased during the late phase of tumor growth. The initial delay of tumor cell engraftment was associated with an increase of tumor capillary density and microvascular permeability. This was associated with an increased vascular endothelial growth factor (VEGF) expression and an enhanced tumor cell invasion of the neighboring tissue. In contrast to the neutralization of SDF‐1, blockade of the SDF‐1 receptors CXCR4 and CXCR7 significantly reduced tumor capillary density and tumor growth. Thus, our study indicates that neutralization of SDF‐1 after hepatectomy is not capable of inhibiting angiogenesis and growth of extrahepatic colorectal tumors, because it is counteracted by the compensatory actions through an alternative VEGF‐dependent pathway.
Investigation on the individual contributions of NH···OC and CH···OC interactions to the binding energies of β‐sheet models
Authors: Wang Chang‐Sheng , Sun Chang‐Liang 
Published: October 2009

AbstractIn this article, the binding energies of 16 antiparallel and parallel β‐sheet models are estimated using the analytic potential energy function we proposed recently and the results are compared with those obtained from MP2, AMBER99, OPLSAA/L, and CHARMM27 calculations. The comparisons indicate that the analytic potential energy function can produce reasonable binding energies for β‐sheet models. Further comparisons suggest that the binding energy of the β‐sheet models might come mainly from dipole–dipole attractive and repulsive interactions and VDW interactions between the two strands. The dipole–dipole attractive and repulsive interactions are further obtained in this article. The total of NH···HN and CO···OC dipole–dipole repulsive interaction (the secondary electrostatic repulsive interaction) in the small ring of the antiparallel β‐sheet models is estimated to be about 6.0 kcal/mol. The individual NH···OC dipole–dipole attractive interaction is predicted to be −6.2 ± 0.2 kcal/mol in the antiparallel β‐sheet models and −5.2 ± 0.6 kcal/mol in the parallel β‐sheet models. The individual CαH···OC attractive interaction is −1.2 ± 0.2 kcal/mol in the antiparallel β‐sheet models and −1.5 ± 0.2 kcal/mol in the parallel β‐sheet models. These values are important in understanding the interactions at protein–protein interfaces and developing a more accurate force field for peptides and proteins. © 2009 Wiley Periodicals, Inc. J Comput Chem 2010
Blind docking method combining search of low‐resolution binding sites with ligand pose refinement by molecular dynamics‐based global optimization
Authors: Vorobjev Yury N. 
Published: October 2009

AbstractThis study describes the development of a new blind hierarchical docking method, bhDock, its implementation, and accuracy assessment. The bhDock method uses two‐step algorithm. First, a comprehensive set of low‐resolution binding sites is determined by analyzing entire protein surface and ranked by a simple score function. Second, ligand position is determined via a molecular dynamics‐based method of global optimization starting from a small set of high ranked low‐resolution binding sites. The refinement of the ligand binding pose starts from uniformly distributed multiple initial ligand orientations and uses simulated annealing molecular dynamics coupled with guided force‐field deformation of protein–ligand interactions to find the global minimum. Assessment of the bhDock method on the set of 37 protein–ligand complexes has shown the success rate of predictions of 78%, which is better than the rate reported for the most cited docking methods, such as AutoDock, DOCK, GOLD, and FlexX, on the same set of complexes. © 2009 Wiley Periodicals, Inc. J Comput Chem 2010