bluuebunny/crossref_metadata_2025_split huggingface dataset:
Low-Speed Fan Noise Reduction with Trailing EDGE Blowing
Authors: Sutliff D.L. , Tweedt D.L. , Fite E.B. , Envia E. 
Published: January 2003

An experimental proof-of-concept test was conducted to demonstrate rotor-stator interaction tone noise reduction through rotor trailing edge blowing. The velocity deficit from the viscous wake of the rotor blades was reduced by injecting air into the wake from a trailing edge slot. Composite hollow rotor blades with internal flow passages were designed based on Computational Fluid Dynamics codes modeling the internal flow. The hollow blade with interior guide vanes creates flow channels through which externally supplied air flows from the root of the blade to the trailing edge. The impact of the rotor wake-stator interaction on the acoustics was also predicted analytically. The Active Noise Control Fan, located at the NASA Glenn Research Center, was used as the proof-of-concept test bed. In-duct mode and farfield directivity acoustic data were acquired at blowing rates (defined as mass flow supplied to trailing edge blowing system divided by fan mass flow) ranging from 0.5% to 2.0%. The first three blade passing frequency harmonics at fan rotational speeds of 1700 to 1900 rpm were analyzed. The acoustic tone mode power levels (PWL) in the inlet and exhaust were reduced 11.5&–0.1, 7.2&11.4, 11.8&19.1 PWL dB, respectively. The farfield tone power levels at the first three harmonics were reduced 5.4, 10.6, & 12.4 dB PWL. At selected conditions, two-component hotwire and stator vane unsteady surface pressures were acquired. These measurements show the modification of the rotor wake due to trailing edge blowing and its effect on the stator vane to illustrate the physics behind the noise reduction.
Crystallographic report: 1,3‐Bis[(trimethylsilylmethyl)dichlorostannyl]propane, [(Me3SiCH2)Cl2Sn]2(CH2)3
Authors: Dakternieks Dainis , Kuan Fong Sheen , Duthie Andrew , Tiekink Edward R. T. 
Published: January 2003

AbstractThe dinuclear molecule of [(Me3SiCH2)Cl2Sn]2(CH2)3 adopts an extended conformation and features distorted tetrahedral tin centres, with the greatest distortion manifested in the CSnC angles of approximately 128 °. The distortions are ascribed to the influence of intermolecular Sn···Cl interactions. Copyright © 2002 John Wiley & Sons, Ltd.
Crystallographic report: 1,4‐Bis(triphenylstannylmethyldimethylsilyl)benzene, p‐(Ph3SnCH2SiMe2)2C6H4
Authors: Dakternieks Dainis , Zobel Bernhard , Tiekink Edward R. T. 
Published: January 2003

AbstractThe dinuclear molecule of p‐(Ph3SnCH2SiMe2)2C6H4 adopts an ‘S’ conformation in the solid state, which is stabilized by CH···π interactions. Distorted tetrahedra defined by C4 donor sets are found for the tin atoms. Copyright © 2002 John Wiley & Sons, Ltd.
Crystallographic report: 1,4‐Bis[(phenyldichlorostannyl)ethyl]benzene, p‐(Cl2PhSnCH2CH2)2C6H4
Authors: Dakternieks Dainis , Duthie Andrew , Tiekink Edward R. T. 
Published: January 2003

AbstractAn ‘S’ conformation, stabilized by intramolecular CH···π interactions, is found in centrosymmetric p‐(Cl2PhSnCH2CH2)2C6H4. The dinuclear species features distorted tetrahedral tin centres, with the greatest distortion manifested in the CSnC angle of 134.32(16) °. Copyright © 2002 John Wiley & Sons, Ltd.
The cholesterol pathway of Trypanosoma congolense could be a target for triphenyltinsalicylate and triphenylsiliconsalicylate inhibition
Authors: Nok Andrew J. , Nock Ishaya H. , Bonire Josiah J. 
Published: January 2003

AbstractThe organometallic compounds triphenyltinsalicylate (TPTS) and triphenylsiliconsalicylate (TPSS) were found to be trypanocidal against culture forms of Trypanosoma congolense. Both compounds at 0.4–5 µmol ml−1 completely killed the parasites in vitro within 3‐8 min after incubation. A dosage of 1.5 µmol ml−1 TPTS killed at least 50% of the parasite population, which was preceded by a cluster effect as observed under phase contrast microscopy. Also, 3.5 µg ml−1 of TPSS was required to kill 50% of the T. congolense cells. At a low dosage of 2–10 µg ml−1, it was feasible to monitor the effect and mode of action of the organometallic compounds. There was a 50% reduction in the amount of synthesized cholesterols in the presence of 6 µg ml−1 and 10 µg ml−1 of TPTS and TPSS respectively. TPTS and TPSS also non‐competitively inhibited pyrophosphatase from lysed T. congolense with Ki values of 3.6 µM and 8.5 µM respectively. In the in vivo experiments, TPTS cured T. congolense infected mice at a dosage of 2–10 mg kg day−1 for 4 days. TPSS was, however, completely inactive in vivo. The use of organometallic compounds in the design of trypanocides is discussed. Copyright © 2002 John Wiley & Sons, Ltd.
Review: Chemistry of the phosphinophosphinidene tBu2PP, a novel π‐electron ligand
Authors: Olkowska‐Oetzel Jolanta , Pikies Jerzy 
Published: January 2003

AbstractIn reactions with transition metal compounds, tBu2PPP(X)tBu2 (X = Br, Me) acts mainly as a precursor of the tBu2PP ligand, whereas tBu(Me3Si)PPP(Me)tBu2 acts as a precursor of the (Me3Si)PPtBu ligand. Up to now, only Pt(0) d10 ML2 metal centres were found to be able to stabilize the tBu2PP group in ‘pure form’ by means of η2‐coordination (side on). Several compounds of the [{η2 − tBu2PP}Pt(PR3)2] type were sufficiently stable to be isolated and characterized; however, not all of them gave single crystals suitable for X‐ray structure determinations. The X‐ray structures of these compounds and of [{µ − (1,2:2 − η − tBu2PP)Pt(PR3)2} {M(CO)5}] strongly suggest the ethene‐like form of 1,1‐di‐tert‐butyldiphosphene in these complexes. Such a form is also in agreement with RI DFT calculations with SVP basis for free tBu2PP. However, in trapping experiments with cyclic olefins and cyclic dienes tBu2PP exhibits, to some extent, electrophilic ‘singlet carbene’ properties. Copyright © 2002 John Wiley & Sons, Ltd.
Organotin(IV) complexes of ethylsarcosine hydrochloride: synthesis, characterization and in vitro cytotoxic activity
Authors: Ronconi L. , Marzano C. , Russo U. , Sitran S. , Graziani R. , Fregona D. 
Published: January 2003

AbstractThe synthesis and characterization of new coordination compounds of some organotin(IV) chlorides with ethylsarcosine hydrochloride (N‐methylglycine ethyl ester hydrochloride) is reported; the ligand molecules appear to be bound to the tin atoms through the carbonyl oxygen atoms by means of dative bonds. As single crystals were not obtained, a number of experimental techniques were used to accomplish a definitive characterization and determination of their structure. The results obtained by 1H, 13C, 119Sn NMR, FT‐IR and 119mSn Mössbauer spectroscopy and thermogravimetric analysis suggested pentacoordination for the 1:1 (Sn:ligand (ESH)) derivatives, [R2SnCl2(ESH)]+Cl−, in a trigonal bipyramidal (TBP) structure, and hexacoordination for the 1:2 complexes, [R2SnCl2(ESH)2]2+2Cl−, in an octahedral structure (R = Me, n‐Bu, Ph; ESH = protonated ethylsarcosine, CH3CH2O(O)CCH2N(CH3)H2+). The triphenyltin(IV) chloride ethylsarcosine hydrochloride derivative exists only as a 1:1 pentacoordinated adduct in a strongly distorted TBP structure. Finally, the compounds have been tested for in vitro cytotoxic activity against human adenocarcinoma HeLa cells, showing, in some cases, a high potency, even at low concentration. Copyright © 2002 John Wiley & Sons, Ltd.
Electrochemically generated tungsten‐based active species as catalysts for metathesis‐related reactions: 1. Acyclic diene metathesis polymerization of 1,9‐decadiene
Authors: Dereli Okan , Düz Bülent , Zümreoğlu‐Karan Birgül , İmamoğlu Yavuz 
Published: January 2003

AbstractThe application of the WCl6–e−–Al–CH2Cl2 system to acyclic diene metathesis polymerization of 1,9‐decadiene is reported. The polyoctenamer formed is of a weight‐average molecular weight of 9000 with a polydispersity of 1.92. IR and NMR spectral analyses indicate the retention of the double bonds in the polymer structure with high trans content as expected from a step condensation reaction. This relatively stable catalytic system, however, also activates the competing vinyl addition reactions while being inactive in ring‐closure metathesis reactions. Copyright © 2002 John Wiley & Sons, Ltd.
Novel synthesis of polyimides of the third‐order optical nonlinearities by microwave assistance
Authors: Lu Jian‐Mei , Ji Shun‐Jun , Chen Nai‐Yong , Zhang Zheng‐Biao , Sun Zhen‐Rong , Zhu Xiu‐Lin , Shi Wei‐Ping 
Published: January 2003

AbstractThe third‐order optical nonlinearities and time responses of three new polymeric materials, which were prepared by polymerization of benzoguanamine (BGA) and pyromellitic dianhydride (PMDA), m,m′‐diaminobenzophenone (m,m′‐DABP) and PMDA, BGA, and 2,4‐tolylenediisocyanate (TDI) under microwave radiation, were measured by a picosecond forward three‐dimensional degenerate four‐wave mixing technique. The experimental results showed that nonresonant optical nonlinearity [χ(3)] of the three polymers is larger by microwave than by heating and that third‐order optical nonlinearities were not only affected by the length of polymer chain, but also by the polymer chain structure. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 87: 1739–1747, 2003
Study of electrical properties for albumin/ poly(vinyl alcohol) blends
Authors: Ragab H. S. , Abo Ellil M. S. , Shehap A. , Abd El‐ Kader F. H. 
Published: January 2003

AbstractThermally stimulated depolarization current (TSDC), d.c. electrical conductivity (σ), and current–time characteristic techniques were used to study electrical polarization and conduction mechanisms for pure poly(vinyl alcohol) (PVA) and 2.5, 5, 10, 12, 15, and 20 wt % albumin content in PVA thin films. The TSDC spectrum for PVA revealed the existence of two broad peaks, while the blend samples show only one broad peak with a shoulder in the high‐temperature side. The existence of this current maximum was analyzed and discussed in terms of dipole‐orientation and space‐charge phenomena. Quantitative analysis was carried out to determine the thermal activation energies of the conduction process, drift mobility, and carrier concentration. The crystallinty of the PVA matrix was enhanced by the addition of albumin, as indicated by X‐ray diffraction and differential scanning calorimetry (DSC) measurements. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 87: 1748–1757, 2003
Miscibility study on blend of thermotropic liquid crystalline polymers and polyester
Authors: Park Dae Soon , Kim Seong Hun 
Published: January 2003

AbstractThe miscibility of thermotropic liquid crystalline polymers (TLCPs) and polyester blends was investigated with thermal and morphological analyses, as well as transesterification. TLCPs composed of 80 mol % para‐hydroxybenzoate (PHB) and 20 mol % poly(ethylene terephthalate) (PET) or 60 mol % PHB and 40 mol % PET, and polyesters such as PET and poly(ethylene 2,6‐naphthalate) (PEN) were melt blended in an internal mixer. DSC analyses were performed to investigate the thermal transition behavior and to obtain thermodynamic parameters. All the blends showed only a single glass‐transition temperature, which means they are partially miscible in the molten state. The Flory–Huggins interaction parameter was calculated employing the Nishi–Wang approach, and negative values were obtained except for the P(HB8‐ET2)/PEN blends. Transesterification was investigated using 1H‐NMR, and the change of chemical shift compared to pure PET or P(HB‐ET)s was observed in the P(HB‐ET)/PET blends. An intermediate chemical shift value (4.83 ppm) was observed in the P(HB6‐ET4)/PEN blends, which indicates transesterification occurred. The fractured surface morphology of scanning electron micrographs showed that the interfaces between the LC droplets and matrix were not distinct. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 87: 1842–1851, 2003
Improvement of silicone endothelialization by treatment with allylamine and/or acrylic acid low‐pressure plasma
Authors: Monge Sophie , Mas André , Hamzaoui Amina , Kassis Camille M. , Desimone Joseph M. , Schué François 
Published: January 2003

AbstractPlasma polymerization of allylamine, acrylic acid, and an allylamine/acrylic acid mixture on Silastic® silicone rubber led to a strong increase in the silicone rubber's hydrophilicity and surface energy. Analysis of the deposited layer by X‐ray photoelectron spectroscopy with 20° and 70° takeoff angles showed segregation of the atoms according to the depth and the incorporation of amino groups, oxygenated groups, and both. The endothelialization of untreated and treated samples was evaluated by the seeding and growth of aorta epithelial cells from pigs in cellular adherence (%), doubling time (in hours), and confluent density (104 cells/cm2). The best results were obtained with the allylamine/acrylic acid mixture treatment, which brought a biocompatibility to Silastic® similar to classic tissue culture on polystyrene plates. The interpretation was based on the presence of NH/CO2− microareas in the deposited layer. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 87: 1794–1802, 2003
Preparation and characterization of nanofiltration membranes fabricated from poly(amidesulfonamide), and their application in water–oil separation
Authors: Chan Wing‐Hong , Tsao Sai‐Cheong 
Published: January 2003

AbstractNanofiltration membranes prepared from selected types of poly(amidesulfonamide) (PASA) targeted to retain either sucrose, raffinose, or β‐cyclodextrin were fabricated in conditions deduced from a chemometric method. Membrane performance was characterized by the permeation of solutions containing 1000 ppm carbohydrates and metal ions. To demonstrate the dependence of the membrane properties on the polymer structure, the separation characteristics of a series of four PASA homopolymers and four PASA copolymers were established. The results allowed us to screen out several promising PASA materials for the NF separation process. In addition, the superiority of the PASA materials, characterized by excellent retention and high flux rate, was evident from the results of a study comparing it with polysulfonamide, poly(ether amide), and commercially available regenerated cellulose. As a means of pollution control, the PASA NF membranes have been proven to be effective in removing oil from oily wastewater. Under an operating pressure of 2–3 psi, a constant flux of 5 L m−2 h−1 and 99.6% retention of a solution of 5000 ppm olive oil could be achieved with the PASA membranes over a period of 430 h. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 87: 1803–1810, 2003
Preparation of conductive polyaniline/nanosilica particle composites through ultrasonic irradiation
Authors: Xia Hesheng , Wang Qi 
Published: January 2003

AbstractPolyaniline/nano‐SiO2 particle composites were prepared through ultrasonic irradiation. Polymerization of aniline was conducted under ultrasonic irradiation in the presence of two types of nano‐SiO2: porous nanosilica and spherical nanosilica. The stability of the colloid dispersion, UV–vis spectra, composition, interaction, conductivity, and other characteristics of the composites were examined. It was found that the aggregation of nano‐SiO2 could be reduced under ultrasonic irradiation and that nanoparticles were redispersed in the aqueous solution. The formed polyaniline deposited on the surface of the nanoparticle, which led to a core–shell structure. Two particle morphologies, threadlike aggregates with a few spherical nanoparticles for porous nanosilica and spherical particles with a few sandwichlike particles for spherical nanosilica, were observed. X‐ray photoelectron spectroscopy showed that for two types of composites the ratio of Si atoms to N atoms (Si:N) on the surface was much higher than that in the bulk. The UV–vis spectra of the diluted colloid dispersion of polyaniline/nano‐SiO2 composite particles were similar to those of the polyaniline system. Fourier transform infrared spectroscopy suggested strong interaction between polyaniline and nano‐SiO2. The conductivity of the polyaniline/porous nanosilica (23.1 wt % polyaniline) and polyaniline/spherical nanosilica (20.6 wt % polyaniline) composites was 2.9 and 0.2 S/cm, respectively. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 87: 1811–1817, 2003
Grafting mechanisms in hybrid miniemulsion polymerization
Authors: Tsavalas John G. , Luo Yingwu , Schork F. Joseph 
Published: January 2003

AbstractThe ultimate objective of hybrid miniemulsion polymerization is to produce a water‐based crosslinkable coating through in situ grafting of a free radical growing acrylic polymer with an unsaturated resin. Certain authors have reported low grafting while others have reported higher. This article explores the factors that influence the grafting tendencies of these systems. Methacrylates such as methyl methacrylate (MMA) have a sterically hindered radical center that lowers its reactivity toward unsaturated resin. This steric hindrance from the methyl group forces grafting of this type of monomer to occur by abstraction of a hydrogen allylic to a resinous double bond. This chain transfer produces a relatively inactive radical on the resin that reduces the grafting efficiency. The transfer process also inherently produces some degree of terminated PMMA polymer within the particle. Grafting occurs in this type of system through termination of living PMMA chains with that radical produced on the resin. For relatively water‐soluble monomers such as MMA, grafting efficiency is further lessened by homogeneous nucleation resulting from the monomer hydrophilicity. These newly created particles cannot contain alkyd due to its hydrophobicity and thus inability to transport across the aqueous phase, and hence cannot produce grafted polymer. Nonetheless, degree of grafting of nearly 50% was observed in these systems. For hybrid systems involving an acrylate monomer such as butyl acrylate (BA), virtually complete grafting with alkyd was observed. This is due to the uninhibited BA radical center allowing the molecule to add directly through a resin double bond. This process offers the possibility for complete grafting. Homogeneous nucleation is not involved in this system due to the insolubility of BA in the aqueous phase. Resin double bond content and degree of conjugation also play an integral role in the grafting process. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 87: 1825–1836, 2003
The essential oil composition of Salvia brachyodon Vandas
Authors: Tzakou O. , Couladis M. , Slavkovska V. , Mimica‐Dukic N. , Jancic R. 
Published: January 2003

AbstractThe essential oils of Salvia brachyodon (samples A and B), collected from Montenegro, were analysed by GC–MS. Fifty‐four constituents were identified. The oil was characterized by a high content of oxygenated monoterpenes. The major constituents were 1,8‐cineole (23.0–17.2%), bornyl acetate (9.8–10.5%) and β‐pinene (8.8–9.4%). Copyright © 2002 John Wiley & Sons, Ltd.
Essential oils of Ocimum basilicum L., O. basilicum. var. minimum L. and O. basilicum. var. purpurascens Benth. grown in north‐eastern Brazil
Authors: de Vasconcelos Silva Maria Goretti , de Abreu Matos Francisco José , Lacerda Machado Maria Iracema , Craveiro Afrânio Aragão 
Published: January 2003

AbstractOcimum basilicum L. occurs everywhere in several forms, varieties and chemotypes whose essential oils presents marked variation on chemical composition. A new analysis of O. basilicum, O. basilicum var. minimum L. and O. basilicum var. purpuracens Benth. growing in north‐eastern Brazil showed that O. basilicum var. minimum represented a true estragole chemotype, while the other two species analysed may be considered linalool chemotypes. Copyright © 2002 John Wiley & Sons, Ltd.
Volatile components of the rhizomes of Cirsium japonicum DC
Authors: Miyazawa Mitsuo , Yamafuji Chikako , Kurose Kohsuke , Ishikawa Yukio 
Published: January 2003

AbstractThe chemical composition of the essential oils from the rhizomes of Cirsium japonicum DC. has been investigated by GC and GC–MS. Sixty‐seven components were identified in the essential oil, with palmitic acid (14.42%), caryophyllene oxide (12.57%), khusinol (6.31%), pentadecanoic acid (6.28%) and myristic acid (4.66%) as the major components. Terpenoids accounted for about 45.22%, especially sesquiterpenoids, which comprised 42.17% of the essential oil. Copyright © 2002 John Wiley & Sons, Ltd.
Volatile constituents of Cymbopogon nardus (Linn.) Rendle
Authors: Mahalwal Vijender S. , Ali Mohd. 
Published: January 2003

AbstractThe steam‐distilled volatile oil obtained from partially dried grass (citronella grass) Cymbopogon nardus (Linn.) Rendle (Syn. Andropogon nardus Linn.), cultivated in the Nilgiri Hills at Ooty, India, was analysed by capillary GC and GC–MS. The partially dried grass contained 35 components, of which 29 constituents, comprising 92.7% of the oil, were completely identified. The oil contains 16 monoterpenes (79.8%), nine sesquiterpenes (11.5%) and four non‐terpenic compounds (1.4%). The prominent monoterpenes were citronellal (29.7%), geraniol (24.2%), γ‐terpineol (9.2%) and cis‐sabinene hydrate (3.8%). The predominant sesquiterpenes were (E)‐nerolidol (4.8%), β‐caryophyllene (2.2%) and germacren‐4‐ol (1.5%). Copyright © 2002 John Wiley & Sons, Ltd.
Essential oil composition of Achillea santolina L. and Achillea biebersteinii Afan. collected in Jordan
Authors: Bader Ammar , Flamini Guido , Cioni Pier Luigi , Morelli Ivano 
Published: January 2003

AbstractThe essential oils of Achillea santolina L. and A. biebersteinii Afan., collected in Jordan, have been studied. The former has never been previously investigated, while the latter evidenced from a literature survey a high variability. The two oils were quite different: A. santolina oil showed mainly 1,8‐cineole, camphor, 4‐terpineol and trans‐carveol, while A. biebersteinii oil contained cis‐ascaridole, p‐cymene, carvenone oxide and camphor among its principal constituents. This is the second report of carvenone oxide from a natural source. Copyright © 2002 John Wiley & Sons, Ltd.
Composition and antimicrobial activity of the essential oils of Helichrysum kraussii Sch. Bip. and H. rugulosum Less. from South Africa
Authors: Bougatsos C. , Meyer J. J. M. , Magiatis P. , Vagias C. , Chinou I. B. 
Published: January 2003

AbstractThe chemical compositions of the essential oils obtained from the aerial parts of Helichrysum kraussii and H. rugulosum were analysed by GC and GC–MS. From the 39 identified constituents, representing 85.1% and 92.9% of the two oils, respectively, β‐caryophyllene (30.7%, 12.6%), α‐pinene (12.1%,−), β‐caryophyllene oxide (−, 8.8%), cis‐α‐bisabolene (−, 22.7%), β‐bisabolene (−, 4.7%) and α‐humulene (9.8%, −) were found to be the main components. Furthermore, the oils were tested against six Gram‐positive or ‐negative bacteria and three pathogenic fungi. It was found that oils from both plants, and especially that of H. rugulosum, exhibited interesting antibacterial activity. Copyright © 2002 John Wiley & Sons, Ltd.
Reduction of cis‐ and trans‐1,2‐epithio‐p‐menth‐8‐ene: preparation of new fragrant terpenoid thiols
Authors: Candela Karine , Fellous Roland , Joulain Daniel , Faure Robert 
Published: January 2003

AbstractThe synthesis of 2‐mercapto‐p‐menth‐8‐ene (3) and 1‐mercapto‐p‐menth‐8‐ene (4) are described, starting, respectively, from thioepoxydation of (+)‐trans‐limonene 1,2‐epoxide (1a) and (+)‐cis‐limonene 1,2‐epoxide (1b) via hydride reduction of episulphides 2a and 2b. Structural determination of these sulphur‐containing terpenoids was achieved by one‐ and two‐dimensional NMR spectroscopy. The odours of these two new monoterpene thiols were described, respectively, as reminescent of grapefruit juice and as being typically alliaceous. Copyright © 2002 John Wiley & Sons, Ltd.