bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dissolved Phosphorus Export from an Animal Waste Impacted In‐Stream Wetland
Authors: Novak J. M. , Szogi A. A. , Stone K. C. , Watts D. W. , Johnson M. H. 
Published: April 2007

AbstractThe ability of wetlands to retain P makes them an important landscape feature that buffers P movement. However, their P retention ability can be compromised through hydrologic disturbances caused by hurricanes and tropical storms (TS). This study had three objectives: (i) to determine the effects of hurricanes and TS on dissolved phosphorus (DP) concentrations and loads discharged from a Coastal Plain in‐stream wetland (ISW); (ii) to evaluate shifts in P storage pools that would reflect P accretion/removal patterns; and (iii) to determine if relationships exist between storm characteristics with releases of DP and water volume. From January 1996 to October 1999, the ISW's outflow DP concentrations and flow volumes (Q) were measured and they were used to calculate DP mass export loads. In addition, the sediment total phosphorus (TP) concentrations were measured, and both the water column and sediment pore water DP concentrations were examined using passive samplers. In several instances, TS facilitated greater DP releases than a single hurricane event. The largest release of DP occurred in 1999 after Hurricanes Dennis, Floyd, and Irene. The large differences in DP exports among the storms were explained by Q variations. Storm activity also caused changes in sediment pore water DP and sediment TP concentrations. This study revealed that some TS events caused higher DP releases than a single hurricane; however, multiple hurricanes delivering heavy precipitation totals significantly increased DP export.
Vulcanization of polychloroprene rubber. I. A revised cationic mechanism for ZnO crosslinking
Authors: Desai H. , Hendrikse K. G. , Woolard C. D. 
Published: April 2007

AbstractData relating to the vulcanization of mercaptan‐grade polychloroprene (CR) by ZnO and MgO (alone or in combination) are examined. Compounds were vulcanized through the isothermal heating of samples at 140°C in a laboratory press and at programmed rates in a differential scanning calorimeter. The reaction was stopped at various points during the heating process. The crosslink densities were determined via swelling. Extractable ZnCl2 and MgCl2 were analyzed by atomic absorption spectrometry. Three different crosslinking processes were identified. The first crosslinking process involved the activation of the highly reactive tertiary allylic 1,2‐units along the polymer chain, whereas the second and third crosslinking processes were attributed to the activation toward crosslinking of 3,4‐ and 1,4‐units, respectively. The crosslinking reactions of the 1,2‐units comprised three distinct steps: isomerization (promoted by ZnO), dechlorination, and crosslinking. ZnCl2 (which formed during compounding and upon crosslinking) promoted crosslinking, and its addition to formulations decreased but did not eliminate the induction period before crosslinking. MgO retarded the crosslinking process by limiting the formation of ZnCl2 during mixing. The results of the CR/ZnO system are discussed, and a modified cationic mechanism for crosslinking is proposed. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Surface‐initiated ring‐opening polymerization of ϵ‐caprolactone from the surface of PP film
Authors: Sui Yuan , Zhao Jingbo , Gan Shenghua , Zhao Hongchi , Yang Wantai 
Published: April 2007

AbstractThis article presents the ring‐opening polymerization of ε‐caprolactone (ε‐CL) from PP film modified with an initiator layer composed of OSn(Oct) groups. This method consists of two steps: (1) Sn(Oct)2 exchanged with the hydroxyl groups on the surface of PP film, forming the OSn(Oct) groups bonded on the surface; (2) surface‐initiated ring‐opening polymerization of ε‐CL with the OSn(Oct) groups. The initiator layer is characterized by attenuated total reflectance‐Fourier transform infrared (ATR‐FTIR), contact angles, and X‐ray photoelectron spectroscopy (XPS). The growth of PCL chains from the initiator layer through ring‐opening polymerization is successfully achieved. ATR‐FTIR, XPS, and scanning electron microscope (SEM) are also used to characterize the grafted film. XPS results reveal that the PCL chains cover the surface of PP film after 4 h. The SEM images reveal that the PCL chain clusters grow into regular spheroidal particles, which can be changed into other different morphology by treated with different solvents. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Peroxide crosslinking of a styrene‐free unsaturated polyester
Authors: Mironi‐Harpaz I. , Narkis M. , Siegmann A. 
Published: April 2007

AbstractThermoset unsaturated polyesters are usually obtained by the crosslinking of unsaturated polyester chains dissolved in an unsaturated, reactive, monomeric diluent, which is usually styrene. This article describes a new approach in which styrene‐free unsaturated polyester chains are intrinsically cured into a crosslinked matrix. The gel time, gel content, swelling degree, glass‐transition temperature, dynamic mechanical properties, tensile properties, and molecular weight between crosslinks (calculated according to both the Flory–Rehner equation and the theory of rubber elasticity) of the crosslinked polymer are studied as a function of the peroxide concentration. All properties change considerably upon the addition of small amounts of peroxide (between 1 and 2 wt %) and change to a lesser extent with higher peroxide concentrations (up to 6 wt %). The thermal properties of the isolated gel fraction are studied as a function of the peroxide concentration. The sol fraction demonstrates a plasticizing effect on the crosslinked network, affecting the glass‐transition temperature and stress–strain behavior of the crosslinked polymer. In light of the crosslink densities derived from swelling experiments, a molecular structure and crosslinking mechanism are suggested for the gel fractions of 1 and 6 wt % peroxide crosslinked unsaturated polyester chains. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Investigation of MWNTs/PBO nanocomposite polymerization mechanism with model compound
Authors: Li Xia , Huang Yudong , Cao Hailin , Liu Li 
Published: April 2007

AbstractA model compound was obtained by reaction of benzoic acid and 4,6‐diamino‐1,3‐dihydroxybenzene dihydrochloride (DADHB · 2HCl) in the presence of functionalized multiwall carbon nanotubes (FMWNTs). FMWNTs were formed on raw multiwall carbon nanotubes (MWNTs) by chemical modification. The model compound was rinsed by chloroform and MWNTs were separated by centrifuge. The sediment yielded was denoted as graft multiwall carbon nanotubes (GMWNTs). Then X‐ray photoelectron spectroscopy (XPS), Raman spectroscopy, and Fourier‐transform infrared (FTIR) were used to investigate the existence of covalent bond between DADHB and FMWNTs. The results of XPS showed that nitrogen atoms amounted to about 3.3% except for oxygen and carbon on the surface of GMWNTs. Meantime, the reaction of COOH of the FMWNTs and themonomer DADHB occurred, and benzoxazole was formed predominantly by Raman spectroscopy analysis. FTIR spectroscopy confirmed the covalent grafting of monomer to FMWNTs in the processing procedure. As a result, the mechanism of the reaction of the poly(p‐phenylenebenzoxazole) (PBO) oligomer and FMWNT composites was deduced according to the reaction of the model compound. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Novel Gd‐substituted LiNi ferrite/polyaniline composite prepared by in situ polymerization
Authors: Jiang Jing , Li Liangchao , Xu Feng 
Published: April 2007

AbstractMagnetic composite containing polyaniline (PANI)‐coated LiNi0.5Gd0.08Fe1.92O4 was synthesized by in situ polymerization of aniline on the surface of LiNi0.5Gd0.08Fe1.92O4 ferrite particles. The obtained samples were characterized by powder X‐ray diffraction, Fourier transform infrared spectra, UV–visible absorption spectra, thermogravimetric analysis, transmission electron microscopy (TEM), and vibrating sample magnetometer. The results of spectroanalysis indicated that there was interaction between PANI chains and ferrite particles. TEM study showed that composite presented the core–shell structure. The composite under applied magnetic field exhibited the clear hysteretic behavior at room temperature. The bonding mechanism in the composite had been discussed. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Preparation and characterization of poly(D,L‐lactic‐co‐glycolic acid) nanoparticles containing 3‐(benzoxazol‐2‐yl)‐7‐(N,N‐diethyl amino)chromen‐2‐one
Authors: Gomes Anderson J. , Assunção Rosana Maria Nascimento , Filho Guimes Rodrigues , Espreafico Enilza M. , Machado Antonio Eduardo da Hora 
Published: April 2007

AbstractNanoparticles (NPs) of poly(D,L‐lactic‐co‐glycolic acid) containing the compound 3‐(benzoxazol‐2‐yl)‐7‐(N,N‐diethyl amino)chromen‐2‐one (C2) were prepared by the solvent‐evaporation technique with a mean loading efficiency of 74.0 ± 3.0%. Size distribution studies, done with dynamic light scattering and scanning electron microscopy, revealed that these particles were spherical in shape, with a mean diameter of 253 nm, a low polydispersity, and a tendency toward aggregation; the last was confirmed by the low ζ potential. A low release profile was observed for C2 when the NPs were dispersed in Hank's buffer (pH = 7.4); this was related to the low porosity of the NPs and the extremely low diffusivity of C2 in water. Differential scanning calorimetry data presented a glass‐transition temperature depression caused by an increase in the NP molecular mobility after the incorporation of C2. Spectroscopic and photophysical data exploring the capabilities of C2 as a fluorescent probe suggested a high microviscosity for the environment in which the probe was allocated, which was most likely due to strong polar interactions involving ester groups from the polymer and the diethylamino moiety from C2. The cellular toxicity and uptake of C2 and NP–C2 systems were evaluated with B16‐F10 murine cells, which showed that C2 (in solution or encapsulated) was nontoxic and able to be located inside the neoplasic cells. Besides, the encapsulation method was capable of maintaining the drug's properties and improved the drug delivery to the target cell. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007
High resolution NMR study of tropical fruit seed starches
Authors: de Miranda Costa Paula , Bruno Tavares Maria Inês , Bathista André L. B. S. , da Silva Emerson O. , Nogueira José S. 
Published: April 2007

AbstractThe nuclear magnetic resonance spectroscopy (NMR) studies of starches obtained by fruit seeds such as melon and watermelon were carried out as an analytical methodology to understand the molecular dynamic behavior. This study was also accompanied by the conventional X‐ray diffraction and thermal analysis. The NMR results give us a complete behavior of the samples at the molecular level. Thus, the information obtained from NMR will complement the data obtained from X‐ray and thermal analysis allowing us having responses on samples structure and dynamical behavior. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Thermal and mechanical properties of polystyrene/poly(acrylonitrile‐g‐(ethylene‐co‐propylene‐co‐diene)‐g‐styrene) (AES) blends prepared by the in situ polymerization of styrene
Authors: Lourenço Emerson , Felisberti Maria Isabel 
Published: April 2007

AbstractPolystyrene/AES blends formed by the in situ polymerization of styrene in the presence of poly(acrylonitrile‐g‐(ethylene‐co‐propylene‐co‐diene)‐g‐styrene) (AES) were prepared. AES is a commercial elastomer obtained by the radical copolymerization of styrene and acrylonitrile in the presence of an ethylene–propylene–diene terpolymer (EPDM). The polystyrene/AES blends presented two phases: an EPDM elastomeric phase dispersed in a rigid matrix. The phase behavior was strongly affected by the polymerization temperature. The blends showed higher thermal stability than the polystyrene homopolymer because of the stabilizing effect of EPDM incorporation. The mechanical properties were influenced by the polymerization temperature and blend composition. The blend prepared at 60°C with 13.0 wt % AES presented an enhancement of 60% in the impact resistance, whereas the blend prepared at 80°C with 21.8 wt % AES presented an enhancement of 150% in the strain at break. Both blends had these properties improved with a small loss in the Young's modulus. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Expression of Concern: Mechanisms of synthetic serine protease inhibitor (FUT‐175)‐mediated cell death
Authors: Uwagawa Tadashi , Li Zhongkui , Chang Zhe , Xia Qianghua , Peng Bailu , Sclabas Guido M. , Ishiyama Satoshi , Hung Mien‐Chie , Evans Douglas B. , Abbruzzese James L. , Chiao Paul J. 
Published: April 2007

AbstractBACKGROUNDConstitutive activation of nuclear factor‐κB (NF‐κB) is a frequent molecular alteration in pancreatic cancer and a number of studies have suggested that constitutive NF‐κB activity plays a key role in the aggressive behavior of this disease. In an attempt to identify an effective therapeutic agent for pancreatic cancer, the authors studied the role of FUT‐175, a synthetic serine protease inhibitor, in the inhibition of NF‐κB activation and the induction of apoptotic responses.METHODSTo examine the effect of FUT‐175 on the inhibition of NF‐κB and the induction of apoptosis in pancreatic cancer cell lines, Western and Northern blot analyses, electromobility shift (EMSA), luciferase reporter gene, DNA fragmentation, immunoprecipitation, in vitro kinase, small interfering RNA (siRNA), and chromatin immunoprecipitation (ChIP) assays were performed.RESULTSIn a time‐dependent and dose‐dependent manner, FUT‐175 inhibited IκBα phosphorylation and NF‐κB activation, thereby inhibiting the antiapoptotic activity of NF‐κB. Simultaneously, FUT‐175 up‐regulated the expression of tumor necrosis factor receptor‐1 (TNFR1), which in turn activated the proapoptotic caspase‐8 and Bid pathways and induced apoptosis in pancreatic cancer cells. FUT‐175‐induced activation of Fas‐associated death domain (FADD) and caspase‐8 was suppressed by RNA interference‐mediated inhibition of TNFR1 expression. Furthermore, expression of the transcription factor PEA3 was up‐regulated by FUT‐175 and was involved in FUT‐175–mediated TNFR1 expression.CONCLUSIONSThese results suggested a possible mechanism by which FUT‐175 may disrupt interconnected signaling pathways by both suppressing the NF‐κB antiapoptotic activity and inducing TNFR‐mediated apoptosis. Supported by this unique function as a NF‐κB inhibitor and apoptosis inducer, this well‐established synthetic serine protease inhibitor with as‐of‐yet poorly understood mechanisms of actions appears to be a potentially therapeutic agent for pancreatic cancer. Cancer 2007. © 2007 American Cancer Society.
Growth and characterization of a novel organic NLO crystal: 4 – ethoxy benzaldehyde – n – methyl 4 – stilbazolium tosylate
Authors: Jagannathan K. , Kalainathan S. , Gnanasekaran T. , Vijayan N. , Bhagavannarayana G. 
Published: April 2007

AbstractThe organic material 4‐Ethoxybenzaldehyde‐N‐methyl 4‐Stilbazolium Tosylate (EBST) is a new NLO material and new derivative in Stilbazolium Tosylate family. In this work we synthesized the EBST, the derivative of DAST. By slow evaporation method, we have grown the EBST crystal. Powder XRD confirms the crystalline property, the lattice parameters are calculated from single crystal XRD data and the molecular structure also revealed. The crystal system is found as monoclinic. The crystalline perfection is assessed by the high‐resolution X‐ray diffractometry. A single and reasonably sharp peak observed in the diffraction curve indicates that the quality of the crystal is quite good without having any internal structural grain boundaries. The FTIR and proton NMR study confirm the presence of functional groups. From the UV – Vis Far IR absorption spectra the good transparency is revealed. The Kurtz Perry SHG test confirms the NLO property of the EBST crystal grown and it is 11 times greater than urea. The melting point of the grown crystal is found to be 237°C from the DSC curve. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Structure and optical damage resistance of In:Yb:Er:LiNbO3 crystals
Authors: Hu Zhenghua , Guo Peng , Li Jingying , Zhen Xihe 
Published: April 2007

AbstractA series of In:Yb:Er:LiNbO3 crystals have been grown. The UV‐Vis absorption spectra and Infrared (IR) transmission spectra were measured and discussed in terms of the spectroscopic characterizations and the defect structure of the In:Yb:Er:LiNbO3 crystals. The optical damage resistance was characterized by the transmitted beam pattern distortion method. The optical damage resistance of In (3.0mol %):Yb:Er:LiNbO3 crystal is one order of magnitude higher than that of other crystal. The dependence of the optical damage resistance on the defect structure was studied. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Role of oxygen vacancies in the coloration of 0.65Pb(Mg1/3Nb2/3)O3‐0.35PbTiO3 single crystals
Authors: Xia Zhiguo , Li Qiang , Cheng Ming 
Published: April 2007

AbstractThe coloration and oxygen vacancies in 0.65Pb(Mg1/3Nb2/3)O3‐0.35PbTiO3 (PMN‐PT(65/35)) (starting composition) single crystals grown by a so‐called modified Bridgman technique were investigated in this paper. Light yellow and dark brown colored crystals were generally observed for the typical as‐grown PMN‐PT(65/35) single crystals. X‐ray diffraction results demonstrated that they were both of pure perovskite structure, but good electric properties were only obtained for the light yellow crystal. X‐ray photoelectron spectroscopy (XPS) was used to investigate the electronic structure of its components. The O 1s photoelectron spectra of the dark brown colored crystals located at the higher binding energy side, which meant the existence of the more oxygen vacancies. It accordingly led to the formation of the low valence cations associated with the coloration of the crystals, which is also testified by the obtained X‐ray photoelectron spectra of Ti and Nb. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Quasi Exact Model for the Anisotropy Driven Weibel Instability all over Fourier Space
Authors: Bret A. 
Published: April 2007

AbstractThe Weibel instability is prompted by a temperature anisotropy within a plasma. We investigate its growth rate for wave vectors making an arbitrary angle with the high temperature axis. We use a two temperatures waterbags model and derive stability conditions depending on both temperatures and wave vector orientation. It is found that the growth rate is maximum for wave vectors normal to the high temperature axis. Also, a critical angle is evidenced in the k space in which direction modes are unstable at high k although the growth rate decreases quickly in this direction. Exact results are derived in most cases. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Dispersion of Dust Acoustic Modes and Perturbations of Plasma Flux Balance
Authors: Tsytovich V. , Morfill G. 
Published: April 2007

AbstractPrevious considerations of dust acoustic waves is demonstrated to be inconsistent ‐ the required equilibrium state for perturbations was not defined since balance of plasma fluxes was neglecting. The self‐consistent treatment shows that plasma flux perturbations are accompanying any collective waves propagating in dusty plasmas and can play an important role in wave dispersion, wave damping and can create instabilities. This is illustrated by the derivation of dispersion relation for dust acoustic modes taking into account the plasma flux balances and plasma flux perturbations by waves. The result of this approach shows that the dust acoustic waves with linear dependence of wave frequency on the wave number exist only in restricted range of the wave numbers. Only for wave numbers larger than some critical wave number for low frequency modes the frequency can be have approximately a linear dependence on wave number and can be called as dust acoustic wave but the phase velocity of these waves is different from that which can be obtained neglecting the flux balance and depends on grain charge variations which are determined by the balance of fluxes. The presence of plasma fluxes previously neglected is the main typical feature of dusty plasmas. The dispersion relation in the range of small wave numbers is found to be mainly determined by the change of the plasma fluxes and is quite different from that of dust acoustic type, namely it is found to have the same form as the well known dispersion relation for the gravitational instability. This result proves in general way the existence of the collective grain attractions of negatively charged grains for for large distances between them and for any source of ionization. The attraction of grains found from dispersion relation of the dust acoustic branch coincides with that found previously for pair grain interactions using some models for the ionization source. For the existing experiments the effective Jeans length for such attraction is estimated to be about 8 – 10 times larger than the ion Debye length and the effective gravitational constant for the grain attraction is estimated to be several orders of magnitude larger than the usual gravitational constant. The grain attraction at large inter‐grain distances described by the gravitationlike grain instability is considered as the simplest explanation for observed dust cloud clustering, formation of dust structures including the plasma crystals. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Tungsten‐Doped Vanadium Oxides Prepared by Direct Liquid Injection MOCVD
Authors: Vernardou D. , Pemble M. E. , Sheel D. W. 
Published: April 2007

AbstractThis paper examines the effect of doping on vanadium(IV) oxide (VO2 (M)) coatings on glass, using atmospheric‐pressure, direct liquid injection metal‐organic (DLI‐MO)CVD, which potentially may find application as part of smart glazing units. It is found that tungsten‐doped VO2 (M) deposited on commercial SiO2‐precoated glass using a 0.1 M solution of vanadyl(IV) acetylacetonate (VO(acac)2) and tungsten (VI) ethoxide (W(OC2H5)5) in methanol shows a reduction in thermochromic transition temperature (Tc) from 60 °C in VO2 (M) to 35 °C in V0.98W0.02O2. This finding is discussed in terms of various atomic percentages of tungsten and oxygen flow rates. The crystallinity, composition, morphology, optical properties, uniformity, and oxidation phase of the films are evaluated by X‐ray diffraction (XRD), Rutherford backscattering spectroscopy (RBS), scanning electron microscopy (SEM), IR reflectance‐transmittance, and Raman spectroscopy, respectively. The relationship between dopant concentration and Tc in the most applicable range for solar window coatings is refined by formation of a single‐phase film and precise determination of these parameters.