bluuebunny/crossref_metadata_2025_split huggingface dataset:
On the effect of nonhomogeneous flow fields on the orientation distribution and rheology of fiber suspensions
Authors: Shanker Ravi , Gillespie J. W. , Güçeri S. I. 
Published: December 2004

AbstractThe influence of nonhomogeneous flow fields on the orientation distribution and rheology of fiber suspensions is investigated. The Stokes‐Burger model is used to approximate the forces and moments on the fiber for the subsequent calculation of fiber angular velocities for nonhomogeneous cases where the velocity gradients vary over the fiber length. For simple shear flows, an analytical solution based on the Stokes‐Burgers model is derived. Fiber angular velocities are compared to previously published results. An iterative numerical technique is developed to calculate the otherwise indeterminate fiber angular velocities for other nonhomogeneous flows, such as non‐isothermal Hele‐Shaw flows. The value of shear is derived for which the angular motion of the fiber in a quadratic velocity field is identical to that in a linear shear flow. Subsequently, numerical solutions for orientation distribution functions are presented for cases where analytical solutions for distribution functions are not obtainable. The rheological properties are then studied, using the orientation tensor description, for nonhomogeneous flow fields where the fiber motion can be approximated by that in a shear flow, the equivalent shear rate obtained from the numerical scheme.
A study on bicomponent two‐layer slot cast coextrusion
Authors: Park Chang‐Won 
Published: December 2004

AbstractExtensional flow of a bicomponent two‐layer slot cast coextrusion process has been studied. A Newtonian and an upper‐convected Maxwell fluid were considered to be the two layers, respectively, and the two‐layer flow was assumed to be steady and isothermal. This choice was made as a simple model for a system which consists of two distinctly different fluids in terms of their extensional behaviors. Present study considered only the draw‐down region where the film thickness changes slowly with the distance from the die exit. For this region, asymptotic solutions could be obtained for two limiting cases in which the elasticity effect of the Maxwell fluid layer is small and the applied tension at the take‐off is large, respectively. When the elasticity effect is small, the melt thickness and the velocity profiles are exponential as in the case of a Newtonian single‐layer flow. When the applied tension is large, on the other hand, the velocity profile is shown to be near linear. Furthermore, the viscoelasticity effect of the Maxwell fluid layer becomes so dominant that it dictates the mechanics of the coextrusion flow even when its flow rate and shear viscosity may be much smaller than those of the Newtonian layer.
The flow distribution of molten polymers in slit dies and coathanger dies through three‐dimensional finite element analysis
Authors: Wang Yeh 
Published: December 2004

AbstractThe isothermal flow of power‐law fluids in slit dies and coathanger dies is studied. A general three‐dimensional finite element code is developed for the purpose of flow analysis. The pressure distribution, the velocity distribution, and the transverse flow rate distribution are obtained. The effect of the die geometry on the flow distribution is critically discussed. It is found that a die channel with cross section of dog bone profile produces a flatter transverse flow rate distribution.
A polarized light scattering approach for dispersed phase morphology characterization in simulated polymer blends
Authors: Bélanger C. , Cielo P. , Patterson W. I. , Favis B. D. , Utracki L. A. 
Published: December 2004

AbstractA light scattering technique using a normal‐incidence polarized light beam for the characterization of skin/core simulated polymer blend samples is described. The patterns of reflected, polarized scattered light from an inhomogeneous blend were captured using a video camera. The blend was illuminated from a focused laser source. The simulated samples were constructed by incorporating glass fibers (skin) and glass microspheres (core) in a polymer matrix. Asymmetrical patterns were obtained. They reflect the anisotropic nature of the near‐surface morphology. Moreover, the change of the anisotropy ratio of the iso‐intensity curves plotted, as a function of distance from the position of the incident laser beam on the sample, gives information about the skin and the core content as well as the skin thickness.
Quantitative model relating electrical resistance, strain, and time for carbon black loaded silicone rubber
Authors: Kost J. , Foux A. , Narkis M. 
Published: December 2004

AbstractA quantitative model has been developed relating electrical resistance with strain and time for carbon black filled silicone rubber compounds. The model is based on concepts and methods used in the field of viscoelasticity. Relaxation experiments are performed in order to evaluate material parameters. With these, resistance‐strain‐history relations, under other loading conditions may be predicted.
On the Sizing Accuracy of Laser Optical Particle Counters
Authors: Szymanski W. W. , Liu Benjamin Y. H. 
Published: December 2004

AbstractThe performance of a narrow‐angle and a wide‐angle, forward scattering laser aerosol spectrometer has been studied as a function of particle size and refractive index. The results have been compared with theoretical calculations based on light scattering theory. The results indicate that for the narrow‐angle instrument, the scattered‐light intensity is not a monotonic function of particle size for transparent particles (a monotonic relationship is required for unambiguous particle size measurement) above 0.7 μm. The instrument is therefore limited in its useful range to size distribution measurement between 0.2 μm – its lower particle size limit – and 0.7 μm for transparent particles. In the case of the wide‐angle instrument, the instrument output is a monotonic function of particle size for transparent particles, but the output is severely attenuated for light absorbing particles above 0.3 μm. The instrument, therefore, cannot be used for accurate size measurements above 0.3 μm for light absorbing particles.
Pore Structure Analysis of Porous Particles by Equivalent Model
Authors: Yan Ji‐Min , Zhang Qi‐Yuan 
Published: December 2004

AbstractStarting from Wheeler's composite theory, which takes both the multilayer adsorption and the capillary condensation into consideration, and assuming the equivalent cylindrical model, we have deduced a strict and relatively simpler formula for the calculation of pore size distribution
equation image
by solving the integral equation directly. The formula is more convenient for application because of its recursion form. Following the same line of reasoning and using the mean value theorem of definite integrals under different conditions, we have unified the equations of Barrett‐Joyner‐Halenda, Dubinin, Cranston‐Inkley, Dollimore‐Heal and Roberts. A table of parameters which is required in the calculation is given. Besides the adsorption of nitrogen, the adsorption with water vapor as the adsorbate is investigated and the corresponding empirical equation of adsorption thickness is given.
Determination of Nitroester and Stabilizer Migration in combustible cartridge case wall
Authors: Ho C.‐H. , Tomkins B. A. , Ramsey R. S. , Griest W. H. , Counts Richard W. 
Published: December 2004

AbstractPropellant nitroesters (diethyleneglycol dinitrate and nitroglycerin) and stabilizer (Akardite II, N‐methyl‐N,N′‐diphenylurea) were determined in combustible cartridge case (CCC) wall specimens from 120 mm M829 rounds which had been exposed to elevated temperatures in environmental chambers or which were returned from deployment in Southwest Asia. The results suggest that the migration of these components from the propellant is uniform about the circumference of the adhesive joint between the CCC body and adapter but not longitudinally above and below the joint. The accumulation appears to be linear with time of exposure, with both nitroesters migrating at approximately the same rate with similar energies of activation. The conventional sampling and analysis method is compared with a new micro‐sampling and analytical method which reduces solvent waste and extraction time, and considerably reduces damage to the rounds from removal of the analytical specimen.
On the deflagration of aluminium/KClO4 mixtures
Authors: Hahma Arno 
Published: December 2004

AbstractExplosive properties of KClO4/Al‐mixtures (60/40) were studied using 15 different types of Al powders. The explosions were photographed and the propagation speed was measured. The detonation and detonation isentrope properties of the mixtures were calculated and the results compared to the measured data. A condensed phase detonation was not detected but shock waves were most likely present in the gas phase. The results indicate that aluminium powder is not able to sustain detonation at all. Additionally, powder with a surface area less than 5 m2/g will not even deflagrate reliably as a mixture with potassium perchlorate.
Primer Compositions in the Course of Time: From black powder and SINOXID to SINTOX compositions and SINCO booster
Authors: Brede Uwe , Hagel Rainer , Redecker Klaus H. , Weuter Waldemar 
Published: December 2004

AbstractStarting with methods used to ignite a propelling charge by means of a piece of glowing charcoal, iron or a burning match in the first firearms of the 14th century, this article contains a detailed description of the direction‐setting milestones and their effects on the development of handguns. The decisive turn‐around in ordnance engineering came with the discovery of impact‐sensitive mixtures and the manufacture or employment of primary explosives, such as mercury fulminate and, in particular, lead trinitroresorcinol and tetrazene, which were used worldwide in the SINOXID primer composition of Dynamit Nobel. With the development of a SINTOX primer composition which set standards by replacing lead, barium and antimony compounds of the SINOXID primer with harmless components, Dynamit Nobel, very early on took account of the public's increasing environmental awareness and health concerns. The same claim is met by the SINCO booster as an environmentally compatible and stable category of substances. Especially also suitable for gas generation in safety systems of motor vehicles for occupant protection. Over many decades, Dynamit Nobel's special achievements have always been characterized by new and innovative pioneering products meeting the changing needs of technology and environment.In many of his entrepreneurial functions both inside and outside the company, Dr. Homburg has shown great scientific and technical competence as a committed exponent of chemistry and technology at Dynamit Nobel. This contribution on primer compositions is dedicated to Dr. Homburg on the occasion of his 60th birthday.
Short‐Action Solid Rocket Motors with Double‐Base Propellants
Authors: Kentgens H. , Mackowiak H. P. , Schöffl R. 
Published: December 2004

AbstractDue to various reasons double‐base solid propellants have been replaced increasingly by composite propellants in the past years. However, the ALARM rocket motor of the Bayern‐Chemie GmbH is one exception. Applications ideal for double‐base propellants are short‐action rocket motors with burning times ranging from some milliseconds up to approximately 200 ms. Various rocket motors of this type were developed at Dynamit Nobel GmbH for different kinds of application. Based on multiple‐tube grains improved designs and manufacturing methods have been developed to enable cost‐effective solutions even at low production rates. This includes also simplified test procedures to supervise the propellant fabrication.
Detonation Products as a Function of Initiation Strength, ambient gas and binder systems of explosives charges
Authors: Volk Fred 
Published: December 2004

AbstractThe way of initiating an insensitive high explosive can influence the start of a detonation reaction remarkably. In order to study the extent of this influence, different boosters and different booster structures for the initiation of explosive mixtures containing TNT and nitroguanidine (NQ) have been used. The experiments have been conducted in a 1.5 m3 containment from which the detonation products could be taken and analyzed. In those cases where we only used a 10 g RDX booster together with a detonation cap no. 8, we had not a complete detonation reaction by initiating cylindrical charges of TNT/NQ and TNT/AN. This means that unreacted TNT was analyzed in the solid residue, mainly consisting of carbon soot. On the other hand, we had a complete detonation using an additional booster of about 18 g detonation sheet, placed on the front side of the cylindrical explosive, having the same diameter as the explosive charge.Another part of the investigations deals with the determination of the influence of different argon pressures on the composition of the detonation gas and the solid residue. Between vacuum and one bar argon a strong change not only of the gas but also of the soot residue was measured. A stronger influence on the products was found using a confinement with glass tubes.The investigation of Al‐containing charges exhibited a very different behavior compared with charges without Al. No more influence of vaccum or of different ambient gas pressure could be observed. By investigation of two composite explosive charges (PBX) containing binder systems of different energies and different oxygen balances, a great influence on the reaction of Al was found. The PBX charges with the better O2‐balance containing the energetic GAP‐binder reacted nearly completely with the Al, opposite to the charge containing the polyisobutylene (PIB) binder system.
Studies on 2,4,6‐Trinitrophenyl Substituted Naphthalenes. Part II. Synthesis of nitro‐ and polynitro‐1‐(2,4,6‐trinitrophenyl)naphthalenes
Authors: Bergman John S. , Duffin Henry C. , Golding Peter , Wells Clifford H. J. 
Published: December 2004

AbstractMononitro‐, dinitro‐, trinitro‐ and tetranitro‐derivatives of 1‐(2,4,6‐trinitrophenyl)naphthalene have been synthesised using a variety of nitration procedures. The mononitro‐ and dinitro‐derivatives have also been synthesised from 1‐bromonaphthalene and 1‐nitronaphthalene via a combination of bromination, nitration and Ullmann reactions.
Synthesis of a New Organic Azide: 1,9‐Diazido‐2,2,8,8‐tetranitro‐4,6‐dioxanonane
Authors: Hong Yan , Xiaopei Guan , Boren Chen 
Published: December 2004

AbstractThe title compound has been synthesized from its appropriate bis(trinitroethyl)formal. For this compound the molecular structure has been determined, and some of the properties are also reported.
Synthesis of 2‐Nitro‐1,3‐Diazidopropane Derivatives
Authors: Naixing Wang , Boren Chen , Yuxiang Ou 
Published: December 2004

Abstract2‐Nitro‐1,3‐diazidopropane derivatives were synthesized through a condensation reaction, substitution reaction and azideation. The molecular structure of the products have been determined by MS, IR, 1H‐NMR.
Sideways Plate Push Test for Detonating Solid Explosives
Authors: Tarver Craig M. , Tao William C. , Lee Chet G. 
Published: December 2004

AbstractA Sideways Plate Push Test has been developed to quantitatively measure the radial acceleration history of a thin metal plate driven by a detonating solid explosive using Fabry‐Perot laser interferometry. This test is designed to compliment the radial expansion cylinder test and axial plate push tests for detonating solid explosives by measuring very precisely the velocity of the metal plate as the explosive reaction products expand from the Von Neumann spike to a volume of approximately three times the initial volume. 1.27 cm thick slabs of LX‐14 (HMX‐based) and LX‐17 (TATB‐based) were detonated to radially accelerate 0.5 mm thick copper and tantalum plates. The measured radial velocity histories of the plates were compared to two‐dimensional hydrodynamic computer code calculations of the experiment. These comparisons showed that the Chapman‐Jouguet (CJ) description of detonation, which neglects the effect of the chemical reaction zone, generally slightly overestimates the radial velocity history of the plate and that the Ignition and Growth Zeldovich‐Von Neumann‐Döring (ZND) reactive flow model, which includes the momentum associated with the chemical reaction zone, yields good agreement with the Fabry‐Perot results. This Sideways Plate Push Test is very useful for determining explosive energy release for applications which depend on the high pressure, early time expansion of the detonation reaction products.
Herbicide sorption to concrete and asphalt
Authors: Ramwell Carmel T 
Published: December 2004

AbstractIn order to accurately predict the fate and behaviour of herbicides following application to hard surfaces, an understanding of the processes involved is required. Previous studies have demonstrated that herbicides with a low soil organic carbon partition coefficient (Koc) are preferentially removed from concrete and asphalt surfaces. It is possible, therefore, that sorption may play a role in retaining herbicides to hard surfaces. This study provides an indication of the extent to which herbicides may sorb to concrete and asphalt, and examines the results in the light of other research to identify the significance of sorption in describing herbicide losses after application. There was measurable sorption of herbicides to concrete and asphalt although this was limited compared with that to soils, especially for concrete. An exponential relationship between experimentally derived values of Kp and literature values of Koc for asphalt was established (r2 = 0.931); there was a weaker relationship for concrete (r2 = 0.606). The experimentally derived Kp values could be used to enhance the prediction of herbicide loss to receiving waters following application. It is probable that the fate of herbicides applied to concrete and asphalt surfaces depends more heavily on physical processes than is the case in soils. Copyright © 2004 Society of Chemical Industry
Expression of a wheat cytochrome P450 monooxygenase in yeast and its inhibition by glyphosate
Authors: Xiang Wen‐Sheng , Wang Xiang‐Jing , Ren Tian‐Rui , Ju Xiu‐Lian 
Published: December 2004

AbstractGlyphosate is a non‐selective herbicide which acts by inhibiting 5‐enolpyruvylshikimate‐3‐phosphate synthase. Wheat cytochrome P450 monooxygenase specifically catalyzes the metabolism of some sulfonylurea herbicides such as chlorsulfuron and triasulfuron. Here we report that glyphosate is an inhibitor of a wheat cytochrome (CYP71C6v1), the cDNA of which was amplified by RT‐PCR and heterologously expressed in yeast. The microsomal fractions derived from this strain had a Soret peak at 502 nm in the reduced carbon monoxide difference spectrum, which is a typical spectral characteristic. The addition of glyphosate to the microsomal protein resulted in a Type II spectrum indicative of binding via the nitrogen group to haem of cytochrome P450 as a sixth ligand. A spectral dissociation constant, Ks of 70 µmol litre−1 was observed and an IC50 of 11 µmol litre−1 was found for glyphosate inhibition of CYP71C6v1 P450 activity. Copyright © 2005 Society of Chemical Industry
New 2‐phenyl‐4,5,6,7‐tetrahydro‐2H‐indazole derivatives as paddy field herbicides
Authors: Hwang In Taek , Kim Hyoung Rae , Jeon Dong Ju , Hong Kyung Sik , Song Jong Hwan , Chung Chang Kook , Cho Kwang Yun 
Published: December 2004

AbstractA series of 3‐chloro‐2‐(4‐chloro‐2‐fluorophenyl)‐4,5,6,7‐tetrahydro‐2H‐indazole derivatives containing various substituted isoxazolinylmethoxy groups at the 5‐position of the benzene ring were synthesized and their herbicidal activities assessed under greenhouse and flooded paddy conditions. Among them, compounds having a phenyl or cyano substituent at the 3‐position of the 5‐methyl‐isoxazolin‐5‐yl structure demonstrated good rice selectivity and potent herbicidal activity against annual weeds at 16–63 g AI ha−1 under greenhouse conditions. Field trials indicated that these two compounds controlled a wide range of annual weeds rapidly with a good tolerance on transplanted rice seedlings by pre‐emergence application. They showed a low mammalian and environmental toxicity in various toxicological tests. Copyright © 2005 Society of Chemical Industry
Towards a practical rechargeable 5 V Li ion battery
Authors: Eglitis R. I. , Borstel G. 
Published: December 2004

AbstractCurrent lithium‐ion batteries are the state‐of‐the‐art power sources for consumer electronics operating mainly in the 4 V regime. One frequently discussed direction to improve the performance of such batteries is the development of a family of 5 V cathode materials. We report here a Full Potential Linearized Augmented Plane Wave (FP‐LAPW) calculation for Li2Co1Mn3O8 in the Fd$\bar 3 $m spinel structure. Our calculated battery voltage for this material is around 5 V. This result is stable against interchange of positions of Mn and Co atoms as well as the choice of the position of the Li vacancy. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Effect of semi‐empirical parameters on the triplet energy levels and triplet–triplet transition in benzene
Authors: Sannigrahi A. B. 
Published: December 2004

AbstractTriplet energy levels and triplet–triplet transition in benzene have been calculated semi‐empirically by considering CI up to and including doubly excited configurations and using various values of the core resonance and electron repulsion integrals. The usual method of calibrating β (core resonance integral) from one of the observed transitions in the semi‐empirical methods is critically examined with respect to the triplet levels of this molecule. Semi‐empirical parameters are found to have a pronounced effect on the energy of the triplets and the triplet–triplet transitions; but the intensities of such transitions are quite insensitive to the choice of such parameters.Numerical results show several 3B1u → 3E2g transitions of various intensities. Out of these, the transitions which correspond energetically to the observed triplet–triplet bands are found to have low intensity. Some strong triplet–triplet bands are predicted in the far ultra violet region.
Theory of intermolecular forces. I. On the inadequacy of the usual Rayleigh‐Schrödinger perturbation method for the treatment of intermolecular forces
Authors: Claverie Pierre 
Published: December 2004

AbstractThe problem of intermolecular interaction is examined by using spatial wave functions and the theory of permutation groups. In the special case of interacting 2‐electron systems it is proven that the Rayleigh–Schrödinger perturbation method, when starting from the ground state of the unperturbed system, could only give the physically inadmissible mathematical ground state of the complex (totally symmetric spatial eigenfunction). Then this property is considered in the case of arbitrary interacting systems and a general proof is proposed. From these results a general explanation of the inadequacy of the Rayleigh–Schrödinger expansion for the treatment of short range intermolecular interaction is proposed.
The optimum projection technique in many‐electron treatments
Authors: Cantu A. A. , Hart‐Davis A. 
Published: December 2004

AbstractThe optimum projection technique is the determination of the best function in the space spanned by a set off f(N, S) linearly independent antisymmetric space‐spin eigenfunctions of S2 obtainable from a spatial function made of a product of N‐independent orbitals. This is formulated in the spin‐free framework. We consider several sets of predetermined orbitals for the lithium 2S state. Both the energy and spin‐density are determined for each optimum projected function. The behavior of certain results is explained in terms of the “closeness” of the ls and ls′ split‐shell core orbitals.