bluuebunny/crossref_metadata_2025_split huggingface dataset:
Glass polyalkenoate dental cements based on physical blends of poly(acrylic acid) and poly(vinyl phosphonic acid)
Authors: Akinmade Ademola O. , Braybrook Julian H. , Nicholson John W. 
Published: May 2005

AbstractPhysical blends of spray‐dried poly(acrylic acid), PAA, with poly(vinyl phosphonic acid), PVPA, have been prepared and used in experimental dental cements by mixing them with basic sub‐45 μm acid‐degradable fluoroaluminosilicate glass powders and adding water. The effect of varying the ratio of PAA to PVPA, of altering the molar mass of PAA, and of using glasses of differing basicity have been investigated. The compressive strengths of the best of the cements formed from these blends were comparable to those formed from the individual polyacids, i.e. about 160 MPa.
Structural analysis of an interphase region of isotactic polypropylene
Authors: Włochowicz Andrzej , Garbarczyk Józef 
Published: May 2005

AbstractSmall‐angle X‐ray scattering (SAXS) data have been used to deduce the localization of organic additives in the bulk of isotactic polypropylene (iPP). The results have shown that changes in the thickness of a transition layer are not directly connected with the introduction of additives but with the content of the hexagonal β‐form. This leads to the conclusion that the additives are placed in the amorphous phase in spite of their crucial influence on the formation of the crystalline phase of iPP.
Temperature dependence of unperturbed dimension and interaction parameters of polyester resin in solvents
Authors: Devi G. Rama , Narender G. , Raju K. V. S. N. , Yaseen M. 
Published: May 2005

AbstractThe flow behaviour of a polyester in various solvents was studied at temperatures ranging from 10 to 80°C. The practical data obtained from the temperature dependence of limiting viscosity number [η] were used to calculate unperturbed dimensions and interaction parameters of the polyester resin in poor, moderate and good solvents. The data provided information regarding conformational transitions in the polymer chains in terms of exothermic or endothermic local ordering of solvents on resin segments and their fixation on polymer coils. The temperature dependence of unperturbed dimensions Ke, Flory–Huggins interaction parameter χ12, the second virial coefficient A2, entropy parameter U1, enthalpy parameter K1, and viscosity expansion factor αn, has been used to estimate the solvent quality for the resin.
Synthesis and binary copolymerizations of 2‐pyrimidyl acrylamide with different alkyl acrylates, vinyl acetate and acrylonitrile
Authors: Hamouly S. H. El , Azab M. M. 
Published: May 2005

Abstract2‐Pyrimidyl acrylamide (2PA) monomer was prepared by the reaction of 2‐aminopyrimidine with acryloyl chloride. Its structure was confirmed by IR, 1H NMR, and MS spectroscopy. Binary copolymerizations of this new monomer with methyl acrylate (MA), ethyl acrylate (EA), butyl acrylate (BuA), methyl methacrylate (MMA), vinyl acetate (VA), and acrylonitrile (AN) were performed in tetrahydrofuran, using 1 mol% azobisisobutyronitrile as initiator at 65°C. N analysis and 1H NMR spectroscopy were used to determine the composition of the copolymers. Copolymerization parameters for each system were calculated by both the Fineman & Ross and Kelen & Tüdös methods. The monomer reactivity ratios for the systems 2PA–MA, 2PA–EA, 2PA–BuA, 2PA–MMA, 2PA–VA, and 2PA–AN were found by the Kelen & Tudos method to be r1 = 0.58±0.042, r2 = 1.26±0.086; r1 = 0.63±0.041, r2 = 1.04±0.072; r1 = 0.88±0.051, r2 = 0.99±0.069; r1 = 0.43±0.021, r2 = 1.60±0.094, r1 = 0.69±0.051, r2 = 0.084±0.088; and r1 = 0.065±0.008, r2 = 2.54±0.220, respectively. The average Q and e values for 2PA were found to be 0.51 and 0.66, respectively.
Photografting of acrylamide on ethylene–vinyl alcohol copolymer film
Authors: Kubota Hitoshi , Sugiura Atsushi , Hata Yasuo 
Published: May 2005

AbstractPhotografting (λ > 300nm) of acrylamide on ethylene‐vinyl alcohol copolymer film (vinyl alcohol unit = 56 mol%, film thickness = 20μm) was investigated at 60°C in water medium, where photoinitiators were coated on the film earlier. The percent grafting decreased in the order of xanthone ≈ benzophenone > anthraquinone > benzoyl peroxide. The graft efficiencies in each sensitized system were less than 30%, showing a predominant formation of homopolymer. Grafting of acrylamide on the film was also initiated in systems with and without photoirradiation when ceric salt was used as an initiator. Based on electron probe microanalysis of the grafted films, the grafted chains of the sample prepared by photografting were distributed inside the film, while those of the sample prepared by ceric salt‐initiated grafting without photoirradiation were located mainly on the film surface. The grafted films prepared by the former system exhibited a higher moisture permeability than those prepared by the latter system.
Synthetic resins XXIX: Synthesis and characterisation of the resins derived from 2,4‐dinitrophenylhydrazone derivatives of resacetophenone–furfural–substituted hydroxy‐aromatic compounds
Authors: Aich Ritanjali , Lenka S. , Nayak P. L. 
Published: May 2005

AbstractA number of resins were synthesised by reacting 2,4‐dinitrophenylhydrazone derivatives of resacetophenone with substituted aromatic compounds and furfural in the presence of some acid and basic catalysts. The physicochemical properties of the resins are reported. The resins were characterised by their IR and NMR spectra. The ion exchange properties of the resins and the influence of electrolytes on the metal uptake of Cu2+, Co2+, Zn2+, Mn2+ and Mg2+ were studied. The distribution of metal ions at different pH are also reported. The thermal properties of the resins were evaluated by TGA, and kinetic parameters were evaluated using the Freeman–Anderson, Broido, Piloyan–Novikova, Coats–Redfern and Horowitz–Metzger methods.
Kinetic analysis of seeded emulsion polymerization of vinyl acetate
Authors: Lange David M. , Poehlein Gary W. , Hayashi Sadao , Komatsu Akihiko , Hirai Toshihiro 
Published: May 2005

AbstractParticle number and size data from a series of seeded, emulsifier‐free, vinyl acetate emulsion polymerization experiments have been analyzed with the aid of polymerization and particle growth models. A secondary population of particles, with a significantly greater number concentration than the seed, was nucleated in all experiments. The two populations (seed and new) had rather narrow size distributions and large diameters. Hence the reactions were in the area normally associated with Smith–Ewart Case III kinetics. Water‐phase termination reactions can be important in this reaction region but radical desorption from such large particles does not significantly influence the kinetics. The results of the analysis were used to evaluate the magnitude of water‐phase termination; to estimate radical capture coefficients; and to evaluate competitive particle growth.
Synthesis and characterization of polyamides containing s‐triazine rings in the main chain
Authors: Sarwade Bhimrao D. , Mahajan Sudhakar S. 
Published: May 2005

AbstractPolyamides were synthesized from diacids containing a s‐triazine ring and two aromatic diamines, namely 4,4′‐diaminodiphenyl ether (ODA) and 4,4′‐diaminodiphenylmethane (MDA), by direct polycondensation using the phosphorylation reaction. Polymers thus obtained were characterized by viscosity measurement, IR spectroscopy, thermogravimetry, X‐ray diffraction, and solubility tests. These polyamides had inherent viscosities in the range of 0.51–0.77 dL/g, and were amorphous in nature. All the polymers were readily soluble in various organic solvents and did not lose weight below 270°C in air.
New TiPTMO and ZrPTMO ceramer hybrid materials prepared by the sol gel method: Synthesis and characterization
Authors: Wang B. , Wilkes G. L. 
Published: May 2005

AbstractNew transparent flexible hybrid network “ceramer” materials have been synthesized by incorporating triethoxysilane capped polytetramethylene oxide with highly reactive titanium isopropoxide or zirconium n‐propoxide without adding chelating agents. Both of these types of ceramer materials display high transparency while the zirconium systems show considerable transparency in the UV region. The titanium systems exhibit higher refractive index than the corresponding zirconium materials of equal alkoxide content.
Surface properties and abhesion of undecyl oxazoline block and homopolymers
Authors: Cai Gangfeng , Litt Morton H. , Krieger Irvin M. 
Published: May 2005

AbstractThe surface properties of three undecyl oxazoline homopolymers and two phenyl/undecyl oxazoline block copolymers (as comparison) were studied. After coating on glass slides and annealing, all films had a low critical surface energy of 21 dynes/cm. Water contact angles were higher than 107° for the most hydrophobic films. The deduction that the polymer surfaces contained close‐packed methyl groups was further confirmed by electron spectroscopy chemical analysis (ESCA) angle profiling on an annealed undecyl oxazoline homopolymer film. A model was developed for the variation of elemental ratios as a function of photoelectron take‐off angle. This verified that the polymer films had the polymer backbones parallel to the surface with the undecyl tails oriented toward the surface. When these block and homopolymers were coated on copy paper and glass slides, the peel strengths of pressure‐sensitive adhesives with these surfaces were very low for short dwell times at room temperature. At long dwell times or at elevated temperatures, the peel strengths remained low for the homopolymers but increased greatly for the block copolymers to values higher than those in the tape on glass. After 24 h at 70°C, ESCA analysis showed that the adhesive diffused into the phenyl block domains of the diblock copolymer, generating high peel strength and cohesive failure. However, under the same annealing conditions, the triblock copolymer showed adhesive failure while peel strength increased. ESCA analysis showed very litle diffusion of the adhesive into the triblock copolymer. The homopolymers were stable toward vinyl acetate type adhesives even at elevated temperature; they were abhesive up to 100°C with no interdiffusion.
Counterion binding to cationic polyelectrolytes in aqueous solution
Authors: Ríos Hernán E. , Gamboa Consuelo , Ternero Gerardo 
Published: May 2005

AbstractThe mean ion activity coefficient, (γ±)px/(γ±)salt for different high‐linear charge density cationic polyelectrolyte fluoride, bromide, chloride and nitrate has been determined. The order found is: F− > CI− ≧ Br− > NO. The results obtained with added nitrate were compared with those predicted by Iwasa, Guéron, and Weisbuch and Manning's models. The latter presents the best agreement for polyion chloride and bromide. It was possible to establish the most probable microconfiguration for the polyions studied here. Manning's theory gives a moderate agreement for polyion fluoride values compatible with a lower charge density than for polyelectrolyte chloride and bromide.
Particle Technology – Manipulating the Divided
Authors: Scarlett Brian 
Published: May 2005

AbstractParticle Technology is a broad and multidisciplinary subject of great importance but diffuse in definition. In this paper a view is presented of the underlying science and its technological applications. In particular a structured subject is dependent upon characterization techniques from which predictions can be made. In this paper the interrelationship between macroscopic and microscopic characterization is discussed. The standardisation and development of the microscopic techniques, particle analysis, is identified as the key to the development of the whole subject.
The Application and Potential of Cluster Analysis in the Interpretation of multivariate particulate data
Authors: Cooke Steven P. , Butters Gordon 
Published: May 2005

AbstractThe classification of powders into groups possessing specific behavioural identities has long been recognized as desirable. This has been approached by describing different powders using two variables and plotting the data on a scatter diagram. The property of interest is then inferred from a powder's position on the scatter diagram. Unfortunately, a powder's behaviour is rarely adequately described by only two variables. To describe a powder more fully requires more variables and this presents a problem in interpretation. Cluster analysis refers to a range of techniques for interpreting multivariate data sets and is used in many fields. This paper describes cluster analysis and considers the method and potential of its application to particle technology. By way of an illustration, a cluster analysis has been performed on twenty‐seven powders resulting in groups recognizable by their characteristic fluidisation and flow properties. It is concluded that cluster analysis could be a powerful tool in predictive and analytical work in the field of particle technology.
Particle Size Analysis of Heterogeneous Powders by Sedimentation
Authors: Bernhardt Claus 
Published: May 2005

AbstractIt is often necessary to carry out sedimentation analysis of powders, consisting of two or more components, which differ in some physical properties. By means of theoretical studies of twocomponent systems the systematic errors of the measured particle size distributions were analysed for the case that differences exist in the following combinations of properties:–particle size distribution D(x) and solid density ϱs–D(x) and mass absorption coefficient μm–D(x) and ϱs and μmUsing real systems (SiO2 + Fe2O3, Al2O3 + SiO2, Al2O3 + Fe2O3) the partial and total errors were estimated and compared with the results obtained with a Sedigraph. Differences in the density of the components often result in negligible errors, even for the system SiO2 + Fe2O3, if the mass portion of one component is below about 10%. For the total error the differences of μm and D(x) are decisive. Its value is below 1% if the mass portion of the slightly absorbing component is <5% or if the strongly absorbing component is <1%.
The Characterizing of Particles by the Manner in which they break
Authors: Barnard W. John , Bull Frederick A. 
Published: May 2005

AbstractA modified drop‐shatter test apparatus was used to study the primary breakage of particles of two solid fuels. In this apparatus many particles could be subjected to just one impact under known conditions.About 100000 particles of each fuel, sorted by size and shape into eight separate groups, were dropped from four different heights and the fragments thus formed were sifted to determine their size distributions, that is the experimental breakage functions.The interior of particles, of regular or irregular shape, fails under tension and the resulting fragmentation is due to stress‐activated volume flaws which give rise to coarse fragments whose distribution can be represented by a theoretical breakage function of the form

where z is the relative size of the fragments and γ is the number of stress‐activated volume flaws per particle.The average values of γ, given by μγ = λ/(1 – e−λ), ranged from about one to five, corresponding to the formation of two to six coarse fragments per broken particle.The probability of breakage was log‐normally related to μγ.
Fractal Description of the Structure of Fresh and Eroded Aluminum shot fineparticles
Authors: Kaye Brian H. , Leblanc John E. , Abbot Paul 
Published: May 2005

AbstractFractal dimensions are numbers between the classical whole number dimensions which can be used to describe the ruggedness of a fineparticle boundary. This communication explores the utility of fractal dimensions between 1 and 2 for characterizing the ruggedness of fineparticle profiles. This type of fractal boundary is evaluated by estimating the perimeter of a profile of a fineparticle at various levels of scrutiny and then plotting a graph of the logarithm of the perimeter estimates against the logarithm of a unit representing the scale of scrutiny. Such a graph is known as a Richardson plot. Boundaries describable by fractal dimensions exhibit characteristic datalines on this type of graph.Aluminum shot fineparticles produced by the break up of turbulent jet of molten metal have irregular shapes because of the fluid turbulence in the regions where they solidify, but a smooth texture because of the effect of surface tension forces as the fineparticle solidifies. It is shown in this communication that the dataline on a Richardson plot of the estimated perimeter of an aluminum shot fineparticle consists of two regions. The first portion, at coarse levels of scrutiny, permits the calculation of a fractal dimension descriptor of the ruggedness of the profile. A second dataline at high resolution is parallel to the scrutiny axis indicating that at such levels of inspection the profile is effectively smooth and euclidean. Studies are reported of the changes in the ruggedness of an eroding aluminum shot fineparticle suspended in acid. It is shown that fractals can be used to describe the progress of corrosion and that, as corrosion proceeds, the euclidean portion of the Richardson plot of perimeter estimate recedes and disappears within the levels of scrutiny employed in these experiments.
Mercury Porosimetry Studies III: A Check on the Validity of the Critical pressure technique for porous powders
Authors: Davidson John A. 
Published: May 2005

AbstractIn any determination of the internal porosity (intra particle porosity) by mercury porosimetry, the penetration curve must be interpreted in such a way that the contribution of the interparticle porosity is deleted. In an earlier communication an experimental technique, known as the critical pressure technique, was developed to accomplish this goal. In this communication a hot stage microscopy image analysis technique is described for the determination of the intra particle porosity of PVC resins. This enables the validity of the critical pressure method to be independently tested. On 12 samples of PVC resin a 1 – 1 correlation between the two methods was found indicating the validity of the critical pressure technique. Another porosity determination technique described earlier, based on the uptake of wetting oil, is also discussed in the light of these findings. This work also illustrates that hot stage microscopy, combined with image analysis, can be used to determine the glass transition of polymers on samples as small as 1·10−8 grams.
Measurement of velocities and diameters of small particles by using fast digital circuits for the on‐line evaluation of laser‐doppler‐signals
Authors: Bauckhage Klaus , Schöne Armin 
Published: May 2005

AbstractInspection of the scattered light by two photodetectors makes it possible to investigate the velocities of droplets as well as their size in disperse systems and has some advantages against related methods. When this method is used, the size of the droplets can be derived from the phase difference of the signals from the first and the second photodetector.Special problems of this method are discussed in the paper. A system with fast signal processing facilities, working mostly digitally, was developed in order to solve these problems. This system derives several digital signals from the signals of high frequencies that are gained from the photodetectors. These digital signals are combined by digital circuits of the ECL‐type. The resulting pulse series are fed into several digital counters. The data from the counters and from some other inputs are further processed by a real time computer that was developed for this special task, using an 8088 micro processor. This real time computer is connected to an ordinary personal computer by a parallel interface.
Particle Deposition in High Capacity Preseparators
Authors: Fissan Heinz , Opiolka Siegfried 
Published: May 2005

AbstractHigh capacity preseparators are used to reduce bounce and blow‐off of large particles in cascade impactors. In this paper, results are presented of a detailed analysis of the deposition of particles in two slightly different preseparators of the impactor‐type which are used in connection with the Andersen Stack Sampler. The advantage of using any preseparator for aerosols mixed with large particles (x 10 μm) is clearly shown.A preseparator which is integrated into the impactor has the advantages of smaller overall size, accessible surfaces and, therefore, easier handling. The results of the study show that the reduction of unwanted particle losses is rather small when compared with a separate preseparator.
The Storage and Handling of Polymer Latices Used as Particle Standards
Authors: Wilkinson Michael , Hearn John , Karpowicz Franciszek , Chainey Malcolm 
Published: May 2005

AbstractLatices of 2, 4 and 9 μm diameter intended for use a particle standard have been examined under a variety of storage and handling conditions. The effects of light exposure, temperature variation and storage in isotonic saline were studied as well as the handling conditions, such as multiple sampling, dispersion technique and effects of foaming. Particle sizes and particle number densities were remarkably constant, even under the most extreme conditions investigated.
An Optical Particle Counting System for Testing Industrial Pulse‐Cleaned Cartridge Dust Collectors
Authors: Liu Benjamin Y. H. , Pui David Y. H. , Schaller Robin E. , McDonald Bruce N. , Johnson Todd W. 
Published: May 2005

AbstractAn optical particle counting system has been developed for testing industrial pulse‐cleaned cartridge dust collectors. The system is applied to measure fractional penetration of a full scale dust collector and to study its short term and long term dynamic behavior. Results show collector efficiencies for dust loadings of 23 g/m3 exceeding 99.999% over the particle size range from 0.5 μm to 10 μm, with a minimum fractional penetration occurring at approximately 2 μm.
Vision‐Guided Flame Control Using Fuzzy Logic and Neural Networks
Authors: Tao Wenjing , Burkhardt Hans 
Published: May 2005

AbstractThis paper presents an application of fuzzy and neural network techniques to a vision‐guided closed loop control for stationary luminous flames. The image processing technique is used to analyze and identify the process states. Fuzzy control strategy avoids the difficulty in establishing a mathematical model for an ill‐defined process. Expert knowledge and training patterns can be incorporated into fuzzy rules, which are represented in the form of neurons. The use of a neural network makes it easy to increase the number of control parameters and provides the system the possibility to adjust its performance automatically.
Extinction of Radiation in Sterically Interacting Systems of Monodisperse Spheres. Part 2: Experimental results
Authors: Kräuter Udo , Riebel Ulrich 
Published: May 2005

AbstractThe Bouguer‐Lambert‐Beer law (BLBL), commonly used to describe the extinction of radiation in disperse systems, is known to be valid in the limit of low concentrations only. In Part [1] it was shown that steric particle‐particle interactions lead to important effects in the range of high particle concentration and two versions of a more general extinction equation including steric interactions were derived for the regimes of fraunhofer diffraction and ray propagation in this part experimental evidence for the effects of steric interactions on the extinction of radiation in suspensions of monodisperse spherical particles is given. Various experiments on light extinction and on ultrasonic extinction are combined to cover a broad range of particle size parameters, mechanisms of particle‐wave interaction and receiver apertures.