bluuebunny/crossref_metadata_2025 huggingface dataset:
Theory of competition between breakup and coalescence of droplets in flowing polymer blends
Authors: Fortelný Ivan , Živný Antonín
Published: December 2004

The Smoluchowski equation for the breakup and coalescence of dispersed droplets has been solved for flowing polymer blends. A scaling form for the distribution of droplet sized derived and published for a system of clusters with fragmentation and coagualation was used in our dervation. Equations are developed here for the average droplet size and for the characteristic time of transition to steady state flow of blends with a high content of the dispersed phase. Expressions reasonably describing the average size of droplets for all concentrations were obtained by a theory modification. Measured dependences of droplet size on the blend composition can be matched only if simultaneous collisions of three and more droplets are considered. The results of the theory indicate that the mechanism of droplet breakup (formation of pieces with the same or different volumes) has only a small effect on their average size in concentrated systems. The dependence of droplet size on the shear rate in flow is determined by properties of the blend components, and is generally nonmonotonic.
Impact testing of polypropylene blends and comosites
Authors: Pukánszky Béla , Maurer Frans H. J. , Boode J.‐W.
Published: December 2004

Polypropylene (PP) composites containing 0.30 vol% of talc filler, in addtion to blends modified with an ethylene‐propylene copolymer (EPR) elastomer were prepared and their fracture resistance was determined by the standard Ixod impact test and by a fracture mechanics technique. Effects of composition, type of modification, specimen size, and temperature were studied. The validity of linear elastic freacture mechanics (LEFM) conditions were checked: It was shown that under the conditions applied they can be satisfied even twith specimens of reasonable size (4 × 10 × 80 mm) prepared by conventional processing techniques. Calculations of minimum specimen thickness must be carried out, with material properties obtained under the conditions of impact. For heterogeneous blends and composites yield stress should be corrected for the effect of decreasing load‐bearing cross section. Linearity of the fracture energy (U) vs. BDϕ or U vs. B(D ‐ a) plots is not a proof for either elastic of plastic fracture. The composition dependence of fracture properties proved to be practicaly independent of specimen size, temperature, or measurement technique.
Canadian fundraising
Authors: Warnett Rebecca
Published: December 2004

Fundraising in Canada has changed substantially over the past fifteen years. The government has shifted away from funding core needs, and more and more Canadians are now donating both their time and their money.
Case study: Good news from the Middle East
Authors: Chahine Houssam
Published: December 2004

Are nongovernmental organizations in the Arab world ready to practice fundraising with Western techniques? This chapter seeks an answer by giving an example of one successful experience in Lebanon.
Nongovernmental organizations and fundraising: Why people equals power
Authors: Quebral Marianne G.
Published: December 2004

As programs and program offices of large foundations close one after the other, Philippine nonprofits and nongovernmental organizations are realizing that their only true allies are the people themselves.
Multinational philanthropy: An opportunity to develop local will and skill
Authors: Hamilton Richard
Published: December 2004

This chapter aims to influence thinking about international fundraising by using practical examples of multinational resource mobilization. It illustrates the value of developing local will and skill to achieve sustainable results.
Dry Etching of Electronic Oxides, Polymers, and Semiconductors
Authors: Pearton Stephen J. , Norton David P.
Published: December 2004

Summary: A review is given of commonly used plasma etching techniques and typical plasma chemistries for patterning electronic oxides, such as SiO2, HfO2, MgO, Sc2O3, and ZnO, polymers, and several important semiconductors (Si, GaAs, and InP). Issues that affect the reproducibility and manufacturability of etching processes, such as loading effects, endpoint detection, and etch selectivity, are also discussed. Finally, disruption to the etched surface in the form of polymer deposition, plasma residues, ion‐induced displacement damage, or preferential loss of one of the lattice elements during the etch process are covered.

SEM micrograph of features etched into a ZnMgO/ZnO structure using a BCl3/Cl2/Ar ICP plasma.

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SEM micrograph of features etched into a ZnMgO/ZnO structure using a BCl3/Cl2/Ar ICP plasma.
Surface Modification of PET Films Using Pulsed AC Plasma Polymerisation Aimed at Preventing Protein Adsorption
Authors: Ademovic Zahida , Wei Jiang , Winther‐Jensen Bjørn , Hou Xiaolin , Kingshott Peter
Published: December 2004

Summary: We utilise pulsed AC plasma polymerisation to create thin films that either contain reactive acid functional groups (by deposition of maleic anhydride (MAH) followed by hydrolysis) or are poly(ethylene glycol) (PEG)‐like in nature (by using diethylene glycol vinyl ether (DEGVE) as monomer). The MAH films were further modified with PEG chains using a two‐step wet chemical method. For the DEGVE films the plasma power was varied in order to change the degree of monomer fragmentation and thus retention of PEG‐like character. The chemistry of the surfaces was determined using Fourier‐transform infrared spectroscopy (FTIR), X‐ray photoelectron spectroscopy (XPS), and time‐of‐flight secondary ion mass spectroscopy (ToF SIMS). Significant reduction (up to 90%) in protein adsorption was achieved by the plasma polymer surfaces as determined using 125I‐radiolabelled fibrinogen adsorption experiments.

AC plasma experimental setup.

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AC plasma experimental setup.
Confederated Miniature Sieves as an Alternative to Nest Sieving
Authors: Kaye Brian H. , Clark Garry G.
Published: December 2004

Miniaturized sieves (1/2 inch diameter) can be mounted in a spinning riffler system to obtain small representative powder samples which eventually can be sieved in situ without removing the miniature sieves from the riffler system. By mounting several different aperture sieves around the riffler a confederation of miniature sieves could replace nest sieving. The sieving surface for these new sieves is so small compared to that of the traditional eight inch sieve that one could consider using the more expensive electroformed sieving surfaces for all test sieves in the quality control laboratory.
Particle Size Analysis of Some Difficult Measurable Systems
Authors: Hoffmann Brigitte , Bernhardt Claus
Published: December 2004

Knowledge of the granulometric behaviour of dispersed systems is vital for a full and complete characterisation. Despite the variety of methods and devices which have been developed for this purpose, difficulties frequently arise in the practical determination of particle size distribution. In this paper it is shown, by means of examples, how measurements for surface modified and porous particles can be influenced by the behaviour of the material, and which approaches exist to obtain accurate values by taking this into account.
Model‐Based On‐Line Analysis of Disperse Systems on the example of digital fourier spectroscopy
Authors: Weiss Martin , Schmidt Marc , Bottlinger Michael
Published: December 2004

With progress in the advancement of measuring techniques and information processing, it is increasingly possible to analyse even complex signals with on‐line methods. After fundamental considerations concerning the evaluation of such signals, digital Fourier spectroscopy is explained as an example of a new development. With this method the image of a particle collection will be transformed by the Fourier transformation. Methods such as used with laser diffraction spectrometry are applied to calculate back to the particle size distribution. After a description of the principles of the procedure, its application is demonstrated by different examples. It can be shown that digital Fourier spectroscopy is superior to conventional image analysis methods especially if the particle density in the image is high and the particles overlap. In a further development step it should be possible to determine the particle size distribution of the bulk from an image of its surface.
Non‐Invasive Size‐Control of Pneumatically Conveyed Particles
Authors: Block Franz Rudolf , Obst Heike‐ursula
Published: December 2004

Investigations on the size control of pneumatically conveyed coarse particles were carried out using a microphone which detects the structure‐borne sound caused by the impact of the particles on the pipe wall. Modes of eigenvibrations of the pipes are excited up to a maximum frequency, which decreases with increasing particle size. In an assembly of different sized particles, the lower frequencies are more stimulated as the fraction of larger particles increases. Changes in the particle size distribution are detected by analysing the intensities of the vibration modes which are set up in the walls of the tube by particle impact. One application is the monitoring of the upper range of a particle size distribution.
Global Analysis of Dynamic Light Scattering Autocorrelation Functions
Authors: Provencher Stephen W. , Štêpánek Petr
Published: December 2004

Dynamic light scattering has become a standard technique of investigating colloidal suspensions and polymer solutions. The experimental field autocorrelation function ĝ1(t) can often be well modelled by a Laplace transform relating ĝ1(t) to a distribution of decay times A(τ). In simple systems A(τ) can usually be directly related to a distribution of molecular weights, particle sizes, diffusion coefficients or other physically relevant quantities, With constrained regularization methods, the parameter‐free estimation of A(τ) has become straightforward. In complex systems, the resulting A(τ) may contain several components the identification of which is not always obvious. The problem often originates in a superposition of diffusive and angle‐independent components that have different variations of their respective decay times with the scattering vector. A method is presented based on a simultaneous fit of several autocorrelation functions measured at several different scattering angles, which, using simple and reasonable assumptions, yields a robust analysis of the spectra of decay times. The application of the method is illustrated on simulated autocorrelation functions and also on real experimental data obtained on a variety of different polymer systems.
The Interaction of the Efflux of Solid Propellants with Nozzle Materials
Authors: Klager K.
Published: December 2004

Progress in obtaining solid composite propellants with highest specific impulse caused severe problems with materials such as graphite used in the construction of insulation and nozzles in solid rockets. Refractory metals provide relief but at the expense of the desired and gained performance increase in propellants. On the basis of data obtained by experimental firings and thermodynamic analysis it was demonstrated that the primary cause of graphite removal in solid rocket motor nozzles is dependent on pressure and on chemical attack by certain species of the exhaust gas. The most damaging gases are those which react with carbon to form carbon monoxide. The chamber flame temperature does not directly affect graphite removal. Analysis of data indicates a good correlation of propellant composition and oxygen balance of the initial propellant from which the exhaust gases are generated. Application of these findings make it possible to select propellant formulations with minimum corrosive action on graphite.
Description of a Shock‐Wave Velocity Barrier
Authors: Walker F. E.
Published: December 2004

An analogy can be drawn between the sonic barrier in transonic flight, the thermal barrier in supersonic or hypersonic flight, and the limiting of the detonation process in high explosives.
Diameter Effect and Failure Diameter of a TATB‐Based Explosive
Authors: Campbell A. W.
Published: December 2004

The detonation velocity of PBX‐9502, an explosive consisting of 95 wt% TATB and 5 wt% Kel‐F 800, was measured precisely over a range of charge diameters at 75°C, 24°C, and −55 °C. The diameter‐effect curves obtained by plotting detonation velocity versus the reciprocal of charge radius were found to differ from those reported in the literature for other solid and liquid explosives, being concave upward at large diameters. The curve at 75°C was found to be a straight line at small diameters and thus simulates the behavior of a homogeneous explosive. At intermediate charge diameters, the effect of varying the temperature by 130°C was quite small. The failure diameter varied from 5.85 ± 0.15 mm at 75°C to 10.5 mm at −55 °C.
A Relationship between Impact Sensitivity and Molecular Electronegativity
Authors: Mullay J.
Published: December 2004

It is shown that statistically significant relationships exist between impact sensitivity and molecular electronegativity for several classes of organic high explosives. These include polynitroaromatic and polynitroaliphatic molecules. The correlations closely follow previous results which utilize the idea of “trigger linkages” (C–NO2, N–NO2 or O–NO2) and oxygen balance. However, the present work provides the possibility of establishing a closer relation between impact sensitivity and electronic structure for the molecules studied. It can also be used to clarify the relationship between the results of previous efforts with these molecules and similar work with other explosives. Through a closer analysis of these correlations it is also shown that the presence of a CO2 moiety in the molecules affects the impact sensitivity.
New Developments in the Field of Firing Techniques
Authors: Ziegler K.
Published: December 2004

After an introducing description about the development of electric firing systems the author tries to answer the question why so many new firing systems were developed within the last years, although the electric firing has reached a high level of elaboration.

The following firing systems are described with their advantages and disadvantages: Magnadet system which works on the basis of electric induction, detonators without primary charge as flying plate detonators or exploding bridge wire detonators, and non‐electric firing systems as Nonel‐system and Hercudet‐system.
Calculation of the Wave‐Shaper Effects on Detonation Wave in Shaped Charges
Authors: Pezzica G. , Pazienza G.
Published: December 2004

Results are presented from two‐dimensional computations simulating the development of detonation for various configurations of shaped charges containing inert elements. These calculations were performed using the nonlinear explicit finite‐difference computer code PISCES 2D ELK. The numerical model employed represented the high explosives by a finely zoned Lagrangian mesh and used JWL (Jones‐Wilkins‐Lee) equation of state with C‐J (Chapman‐Jouguet) burn model. The inert elements were modeled by Lagrangian grids and used Mie‐Grueneisen equations of state with a linear relationship between the shock velocity (Us) and particle velocity (Up) fitting the Hugoniot data of the inert materials. The development of detonation waves all around the wave‐shaper are shown in contour plots of pressure at various time steps during the calculations. Mesh plots of the different configurations are also reported. Our simulations are compared with previous radiographic and numerical results for a slab of explosive with an aluminium confinement and with recent not yet published streak‐camera tests on a particular shaped charge configuration with hemispherical wave‐shaper. Our numerical results appear to be in good agreement with the experimental data.
Combustion Mechanism of Azide Polymer
Authors: Kubota N. , Sonobe T.
Published: December 2004

The combustion wave structure and thermal decomposition process of azide polymer were studied to determine the parameters which control the burning rate. The azide polymer studied was glycidyl azide polymer (GAP) which contains energetic – N3 groups. GAP was cured with hexamethylene diisocyanate (HMDI) and crosslinked with trimethylolpropane (TMP) to formulate GAP propellant. From the experiments, it was found that the burning rate of GAP propellant is significantly high even though the adiabatic flame temperature of GAP propellant is lower than that of conventional solid propellants. The energy released at the burning surface of GAP propellant is caused by the scission of NN2 bond which produces gaseous N2. The heat flux transferred back from the gas phase to the burning surface is very small compared with the heat generated at the burning surface. The activation energy of the decomposition of the burning surface of GAP propellant, Es, is determined to be 87 kJ/mol. The burning rate is represented by r = 9.16 × 103 exp(–Es/RTs) where r (m/s) is burning rate, Ts (K) is the burning surface temperature, and R is the universal gas constant. The observed high temperature sensitivity of burning rate is correlated to the relationship of (∂Ts/∂T0)p = 0.481 at 5 MPa, where T0 is the initial propellant temperature.
Evaluation of a new organic azide: Hexakis(azidomethyl)benzene (HAB)
Authors: Gilbert E. E. , Voreck W. E.
Published: December 2004

HAB is a thermally‐ and hydrolytically‐stable solid, easily prepared from available raw materials. It is not highly sensitive to shock, friction, or electrostatic charge, but is sensitive to some types of impact, although not to others. It shows preliminary promise for possible use as a substitute for normal lead styphnate in less‐sensitive bridgewire detonators, and as a substitute for tetracene in percussion detonators, e.g. the M‐42 primer. Easy ignition, and a high burning rate without detonation, suggest application as an igniter. HAB is not sufficiently powerful to dent an aluminum witness block; therefore, it would not be suitable as a replacement for lead azide as an intermediate detonator charge.
Role of Boron in Burning Rate Augmentation of AP composite propellants
Authors: Kuwahara T. , Kubota N.
Published: December 2004

Effect of the addition of boron particles on the burning rate of solid propellants was examined. The propellants tested in this study consisted of ammonium perchlorate (AP) as an oxidizer and carboxyl terminated polybutadiene as a fuel binder. The propellant burning rate is increased significantly by the addition of a small amount of boron particles. The burning rate augmentation is dependent largely on the size and concentration of the boron particles mixed. Thermochemical experiments revealed that the boron particles react with the decomposed gases of AP on and just above the propellant burning surface. The heat flux transferred back from the gas phase to the burning surface of the propellant increases with increasing the total surface of the boron particles mixed within the unit mass of propellant. The burning rate augmentation is correlated to the heat of reaction generated by the oxidation reaction of boron particles.
On the Hydrodynamic Theory of Detonation
Authors: Schall R.
Published: December 2004

When the enthalpy of the unreacted explosive is correctly taken into account, the detonation rate D depends to some extent on the explosive's sound speed a0. With a perfect or Abel gas equation, correction terms of the order \documentclass{article}\pagestyle{empty}\begin{document}$ 1 - \frac{{{\rm a}_{\rm 0}^{\rm 2} }}{{{\rm D}^{\rm 2} }} $\end{document} with respect to the classical theory are obtained. They increase D, but lower density and pressure in thc C‐J plane. This agrees with the finding that data derived from experiments on the basis of the classical theory correspond better to a weak Than to a C‐J detonation. The observed difference in density coefficients, dD/dϱ0, of liquid and solid TNT as well as the anisotropy of D of elastically stretched rubberized high explosives are quantitatively understood. It is shown that the extended equations, though based on a gas equation of state, hold approximately for condensed explosives too, provided their compressibility is not too low.
The Initiation Threshold Sensitivity of LX‐15 Explosive as a function of its grain size
Authors: Gvishi M. , Solomonovici A.
Published: December 2004

The effect of the explosive binder 5 w/o‐Kel‐F‐800 on the initiation threshold sensitivity of LX‐15 had been measured. The initiation threshold (kinetic energy of flyer plate) versus explosive grain size shows constant difference of 5.5 ± 0.5 J/cm2 between threshold curves of HNS and LX‐15 explosives (HNS plus 5 w/o‐Kel‐F‐800). This result can be explained by hot spots model.
The cylinder test in the context of physical detonation measurement methods
Authors: Hornberg H. , Volk F.
Published: December 2004

A survey is given of the problems encountered in measuring where detonation physics are involved and the measurement procedures applied in their solution. The cylinder test is assigned a part within this framework and compared with competing measurement procedures. This test makes it possible to calculate the progression of detonation product expansion from the widening of the tube measured which, in turn; is needed as an input for computer programs to examine material deformation caused by explosives. The LLNL and ICf evaluation programs are presently available for this purpose. In addition, Gurney energies can also be determined as characteristic magnitudes for explosive effects either directly from the tube expansion or indirectly from the product expansion. Apart from density of explosive and velocity of detonation, both the Chapman‐Jouguet pressure as well as the detonation heat are required in order to establish the initial point of the product expansion curve. In the ICT program, both quantities can also be obtained through detailed examination of the flow conditions in tubes of variable cross‐sections, in conjunction with limit observations on the wall expansion progression; this makes the cylinder test independent of other measurement procedures.
Energetics of BAMO
Authors: Miyazaki Toshio , Kubota Naminosuke
Published: December 2004

3,3‐Bis(azidomethyl)oxetane (BAMO) is a typical energetic azide polymer containing two N3, bonds in the molecular structure. Since BAMO is a solidified polymer at room temperature, a liquid BAMO copolymer with tetrahydrofuran (THF) was synthesized in order to gain energetic binders for solid propellants. Various types of experiments were carried out to elucidate the decomposition and combustion processes of BAMO polymer, BAMO/THF copolymer, and crosslinked BAMO/THF copolymer. The heat produced by the decomposition is caused by the bond breakage of ‐N3 to produce N2, gas. The burning rate characteristics of crosslinked BAMO/THF copolymer depend largely on the mole fraction ratio of BAMO and THF.
Thermal Stability of ε‐Hexanitrohexaazaisowurtzitane in an Estane Formulation
Authors: Foltz M. Frances
Published: December 2004

A change in color and density during prolonged heating of a formulation containing ε‐hexanitrohexaazaisowurtzitane (HNIW) and Estane 5702 was investigated by Fourier transform infrared (FTIR) spectroscopic analysis. Starting materials, virgin and final colored formulation were studied. Analysis revealed polymorphic impurity at all stages of production and processing, the nature and concentration of which changed with treatment of the material. Thermally‐induced polymorphic conversion was determined to be the cause of the decrease in density, whereas the color change was speculated to be the result of binder degradation. Sensitivity to impact, friction and electrostatic spark were unchanged.
Review on Benzofuroxan System Compounds
Authors: Naixing Wang , Boren Chen , Yuxiang Ou
Published: December 2004

This paper reviews on benzofuroxan system compounds about structure, preparation and development. The replacement of nitro groups by furoxano groups on aromatic ring can increase density, detonation velocity and energy of explosives, so benzofuroxan system compounds and some energetic materials have aroused much attention.
Flame Spreading in a LOVA Charge: An Experimental Study
Authors: Wildegger‐Gaissmaier A. E. , Johnston I. R. , Teague G.
Published: December 2004

LOVA propellants due to their low sensitivity are difficult to ignite. ‘Non‐ideal’ ignition can result in loss of accuracy, misfire, hangfire or catastrophic failure of the gun. The flame spreading event can be used to evaluate the ignition process. An experimental technique has been developed to aid in the investigation of flame spreading in gun charges. Fibre optic sensors as a direct measurement method were used to record radial and axial flame spreading. Experiments were conducted for three different igniter designs. Significant differences in the flame spread history for the three igniters were found and the technique proved to be suitable for optimization of ignition systems. Results of the experimental study could be used to validate interior ballistic model predictions.
Time calculation for the after‐cure cooling process of the cast modified double base propellant in a large rocket motor
Authors: Zhanning Jia
Published: December 2004

An unsteady heat conduction model is proposed to calculate the temperature distribution of the case‐bonded rocket motors and the time required for the cooling process based on the experimentally determined thermal and mechanical parameters of a cast modified double base propellant (CMDB) and its glass steel shell. The resultant value of the time is then used to derive the corresponding stress relaxation modulus, which is compared with the modulus data obtained from uniaxial tensile stress relaxation experiments to see if the internal stress has been thoroughly relaxed within this period of time.
Transport and magnetotransport properties of cold‐pressed CrO2 powder
Authors: Liu H. , Zheng R. K. , Wang Y. , Bai H. L. , Zhang X. X.
Published: December 2004

Resistivity of cold‐pressed CrO2 powder has been measured over the temperature range of 2 to 350 K with a magnetic field up of to 50 kOe. High resolution transmission electron microscopy (HRTEM) images show that the CrO2 particles are needle‐shaped with an aspect ratio of 7:1 and have an average length of 200 nm, and are covered with an ultra‐thin (∼2.5 nm) native Cr2O3 layer. Temperature dependent conductivity can be well described by the expression below 55 K, a feature of electron tunneling, and by the higher‐order hopping for temperature above 55 K. The magnetoresistance, , reaches ∼33.5% at 2 K and decreases to nearly zero at room temperature. Temperature dependent saturation magnetization follows well the relation below 240 K. The spin‐wave stiffness constant, D, is estimated to be ∼91 meV Å2. By fitting the specific heat measured in the temperature range of 1.8–34 K by the relation , we obtained the electronic specific heat coefficient γ = 1.7 mJ/mol K2, this corresponds to a density of states at the Fermi level of 0.73 states/eV, which is in good accordance with the theoretical value of 0.69 states/eV.
Hohenberg–Kohn theory including spin magnetism and magnetic fields
Authors: Kohn Walter , Savin Andreas , Ullrich Carsten A.
Published: December 2004

Beginning with work by U. von Barth and L. Hedin in 1972 and continuing with recent papers in 2001 by K. Capelle and G. Vignale and by H. Eschrig and W. E. Pickett, questions have been raised about the meaning and validity of Hohenberg–Kohn theory when spin magnetism and/or magnetic fields are present. This article offers clarifications of some of these questions. In particular, it also concludes that these questions do not affect spin‐density functional theory for nondegenerate ground states as currently practiced. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2004
Quantitative electron spectroscopy of surfaces: A standard data base for electron inelastic mean free paths in solids
Authors: Seah M. P. , Dench W. A.
Published: December 2004

A compilation is presented of all published measurements of electron inelastic mean free path lengths in solids for energies in the range 0–10 000 eV above the Fermi level. For analysis, the materials are grouped under one of the headings: element, inorganic compound, organic compound and adsorbed gas, with the path lengths each time expressed in nanometers, monolayers and milligrams per square metre. The path lengths are vary high at low energies, fall to 0.1–0.8 nm for energies in the range 30–100 eV and then rise again as the energy increases further. For elements and inorganic compounds the scatter about a ‘universal curve’ is least when the path lengths are expressed in monolayers, λm. Analysis of the inter‐element and inter‐compound effects shows that λm is related to atom size and the most accuratae relations are λm = 538E−2+0.41(aE)1/2 for elements and λm=2170E−2+0.72(aE)1/2 for inorganic compounds, where a is the monolayer thickness (nm) and E is the electron energy above the Fermi level in eV. For organic compounds λd=49E−2+0.11E1/2 mgm−2. Published general theoretical predictions for λ, valid above 150 eV, do not show as good correlations with the experimental data as the above relations.
Mean free path for inelastic scattering of 1.2 kev electrons in thin poly(methylmethacrylate) films
Authors: Roberts R. F. , Allara D. L. , Pryde C. A. , Buchanan D. N. E. , Hobbins N. D.
Published: December 2004

Mean free paths for inelastic scattering (λ) of low energy electrons in poly(methylmethacrylate) (PMMA) have been determined by measuring Al Kα excited C 1s and Si 2s photoelectron signal intensities as a function of ellipsometrically determined thicknesses of PMMA overlayers on silicon substrates. The λ values obtained are 29 ± 4 Å for 1196 eV electrons and 33 ± 5 Å for 1328 eV electrons. These data are necessary for the quantitative analysis of the surface region of PMMA and similar polymers by X‐ray photoelectron spectroscopy (XPS). The magnitude of the λ values determined indicates that XPS measurements can provide chemical information about the surface region of polymers, such as PMMA, in the depth range of ∼6 to 100 Å. The results of this study are compared and discussed with respect to λ values determined for other organic compounds.
Determination of relative transmission function of two scanning modes of an electrostatic hemispherical analyser with a lens system
Authors: Richter K. , Peplinski B.
Published: December 2004

Evidence is provided, that the transmission function Tp,a of an electrostatic hemispherical analyser with a lens system, operated at fixed transmission energy (FATE mode) relative to that for operation at fixed retarding ratio (FRR mode) varies with kinetic energy E according to E−1.25 (400 eV < E < 1470 eV).
X‐ray photoelectron study of surface compounds formed during flotation of minerals
Authors: Nefedov V. I. , Salyn Ya. V. , Solozhenkin P. M. , Pulatov G. Yu.
Published: December 2004

The compounds formed on the surface of minerals under the action of flotation reagents have been studied by ESCA. On a ZnS surface treated with CuSO4 solution, Cu2S and SO were identified. The quantity of Cu2S increased and that of SO decreased with increased Fe content in ZnS. After treatment of PbS with K2Cr2O7 solution, a combination of Cr2O3 and Pb(OH)2, or PbCr2O4 was formed on the surface. The action of Pb(NO3)2 solution on Sb2S3 led to the formation of PbSb2S4 type compounds. HgO or HgS were formed on an Sb2S3 surface after treatment with (C2H5)2NC6H4HGOCOCH3 solution. In all cases excluding the PbS and K2Cr2O7 system the quantity of products formed on the surface increased with reagent concentration.
X‐ray photoelectron spectroscopic and electron spin resonance studies of cobalt species in CoMo/γ‐Al2O3hydrodesulfurization catalysts after operation for eight hours under pressure
Authors: Gajardo P. , Grange P. , Delmon B.
Published: December 2004

We report X‐ray photoelectron spectroscopic and electron spin resonance data on Co/γ‐Al2O3and CoMo/γ‐Al2O3catalysts Co/(Co+Mo) = 0.35 after sulfidation and catalytic operation under 30 bars pressure at 305°C for eight hours. The catalysts were protected from air contamination. Data on catalytic activity (hydrogenolysis of thiophene and hydrogenation of cyclohexene), X‐ray diffraction and diffuse reflectance spectroscopy are also reported. A reduced cobalt species is associated with Co9S8on Co/γ‐Al2O3. This species is not detected on CoMo/γ‐Al2O3, where cobalt occurs as CoAl2O4and as cobalt in a fully sulfided form, quite probably as Co9S8. If the hypothesis of the synergy by contact is correct, the results indicate that unreduced Co9S8is the activating agent.
Empirical atomic sensitivity factors for quantitative analysis by electron spectroscopy for chemical analysis
Authors: Wagner C. D. , Davis L. E. , Zeller M. V. , Taylor J. A. , Raymond R. H. , Gale L. H.
Published: December 2004

Quantitative information from electron spectroscopy for chemical analysis requires the use of suitable atomic sensitivity factors. An empirical set has been developed, based upon data from 135 compounds of 62 elements. Data upon which the factors are based are intensity ratios of spectral lines with F1s as a primary standard, value unity, and K2p3/2 as a secondary standard. The data were obtained on two instruments, the Physical Electronics 550 and the Varian IEE‐15, two instruments that use electron retardation for scanning, with constant pass energy. The agreement in data from the two instruments on the same compounds is good. How closely the data can apply to instruments with input lens systems is not known. Calculated cross‐section data plotted against binding energy on a log‐log plot provide curves composed of simple linear segments for the strong lines: 1s, 2p3/2, 3d5/2 and 4f7/2. Similarly, the plots for the secondary lines, 2s, 3p3/2, 4d5/2 and 5d5/2, are shown to be composed of linear segments. Theoretical sensitivity factors relative to F1s should fall on similar curves, with minor correction for the combined energy dependence of instrumental transmission and mean free path. Experimental intensity ratios relative to F1s were plotted similarly, and best fit curves were calculated using the shapes of the theoretical curves as a guide. The intercepts of these best fit curves with appropriate binding energies provide sensitivity factors for the strong lines and the secondary lines for all of the elements except the rare earths and the first series of transition metals. For these elements the sensitivity factors are lower than expected, and variable, because of multi‐electron processes that vary with chemical state. From the data it can be shown that many of the commonly‐accepted calculated cross‐section data must be significantly in error—as much as 40% in some cases for the strong lines, and far more than that for some of the secondary lines.
Polymer functional group mobility. 2—Partition of ion pairs between hydrophobic and hydrophilic phases of plasma oxidized polyethylene
Authors: Everhart Dennis S. , Reilley Charles N.
Published: December 2004

Plasma modification of polyethylene is modeled most simply as a process generating a two phase polymer system: a thin hydrophilic surface phase and a relatively unperturbed hydrophobic bulk phase. The oxidized surface of polyethylene exposed to a N (PEN) or to an Ar (PEAr) glow discharge plasma contains functional groups of N (i.e., amines) and of O (i.e., alcohols, carbonyls and carboxylic acids) and constitutes an interesting, chemically unique phase of the polymer. Lipophillic protonated alkyl ammonium nitrates, perchlorates and iodides are more soluble in the internal, hydrocarbon phase of the modified polymer and consequently show negligible electron spectroscopy for chemical analysis intensities. On the other hand, the hydrophilic protonated alkyl ammonium phosphates, sulfates and chlorides concentrate in the more polar surface phase and are readily detected by electron spectroscopy for chemical analysis. Electron spectroscopy for chemical analysis of protonated alkyl ammonium chlorides and iodides is complicated by the evolution of HCl and HI, respectively, into the vacuum. Complete protonation of the N functional groups of PEN with H2SO4 is prevented by prior intra polymer reactions of amines with carbonyl and carboxylic acid groups to form less basic imines and amides, respectively. Sodium carboxylate salts are more soluble in the surface hydrophilic phase, whereas tetrabutylammonium carboxylate salts readily partition into the internal hydrophobic phase. The partition of functional groups between the hydrophilic surface phase and the hydrophobic bulk phase will exert a profound influence on their availability for reaction at the polymer surface.
Suppression of metal surface oxidation during laser surface treatments
Authors: Draper Clifton W. , Kaufmann Elton N. , Buene Leif
Published: December 2004

Inert cover gases (He, Ar and N2) are commonly used to protect optical lenses, suppress plasma formation and inhibit metal surface oxidation during high power laser treatments. In the three examples studied, widely varying degrees of effectiveness have been found. A 20 lb inch−2nozzle gas of Ar is found to be effective in prohibiting oxidation of polycrystalline Ni during surface melting with a continuous CO2laser. A CuAlFe alloy, however, oxidizes significantly under nearly identical conditions. It has been found that the redistribution of Hf, implanted in single crystal Ni and laser surface melted with Q‐switched Nd–YAG laser pulses, is sensitive to whether the laser melting is done in air or with a He cover gas. This, in spite of the fact that the melt time is less than 500 ns. We conclude that the use of an inert gas or very short laser pulses does not necessarily prohibit the gaseous ambient from reacting with metal surfaces during laser treatments.
Depth profiling by SIMS—depth resolution, dynamic range and sensitivity
Authors: Magee C. W. , Honig R. E.
Published: December 2004

Depth profiling by secondary ion mass spectrometry is described with emphasis on three important aspects: (1) depth resolution, (2) dynamic range and (3) sensitivity. It is shown how, for samples which do not roughen during sputtering, depth resolution is limited by atomic mixing effects and the flatness of the analyzed area. The dynamic range of depth profiles is shown to be limited by (a) crater edge effects, (b) neutral beam effects and (c) several types of instrumental background. These include mass spectral overlap, residual gas contamination, redeposition and ‘memory’ effects, and detection of unfilterable particles. In the absence of measurable background, sensitivity is shown to be related to analyzed area and depth resolution.
SIMS study of a 55% AlZn alloy coating for corrosion protection of steel wire products
Authors: Van Craen M. , Adams F. , Haemers G.
Published: December 2004

Secondary ion mass spectrometry with a Cameca ion microscope was used to study the surface and in‐depth composition of a 55 wt % AlZn coating on steel wire. Several surface contaminants of the coating (C, Na, Mg, F, Cl, K, Ca, Mn and Fe) were identified and the spatial distribution of some of them and of the coating components Al, Si and Zn were obtained. The dendritic–interdendritic structure of the AlZn coating was observed using a secondary ion imaging facility. The distribution at the surface of the coating constituents Na and Cl, C and Al and Mn and Fe were strongly correlated. Quantitative analysis showed that the Mn and Fe surface concentrations were some hundreds and some thousand p.p.m. wt, respectively.
Behaviour of water containing materials in the high vacuum of an X‐ray photoelectron spectrometer
Authors: Hirokawa K. , Danzaki Y.
Published: December 2004

In order to examine the behaviour of water containing materials in the high vacuum of an electron spectrometer, semi‐quantitative XPS measurements of the atomic ratio of O to an element in certain inorganic compounds were carried out. Materials investigated were CuSO4·5H2O, KCr(SO4)2·12H2O, FeC2O4·2H2O, Sn(OH)2, Al(OH)3, Fe(OH)3, Ti(OH)4, Zn(OH)2, Zr(OH)4 and some metals. It can be anticipated from the correlation between the vapour pressure, of water and temperature that water containing materials, which are dehydrated under 400 °C at normal pressure, lose water under a vacuum of about 10−8 Torr. Of course, it became clear that measurements of water containing materials in the high vacuum should be performed very carefully.
The correlation of the auger parameter with refractive index: An XPS study of silicates using Zr Lα radiation
Authors: West R. H. , Castle J. E.
Published: December 2004

The value of using Zr Lα x‐rays as a source for the XPS study of AlSi compounds is proved by their ability to generate strong Al and Si is and KLL Auger peaks and with sufficient resolution for peak energies to be determined accurately. A study of the resultant Al and Si Auger parameters has been made for some 30 silicates and comparison with refractive index data allows the Auger parameters to be scaled directly with the polarization energy of the surrounding O ions. The O polarizability dominates the bulk polarizability in silicates and its magnitude is controlled by its site co‐ordination number and the electronegativity of charge‐balancing cations in the structure. Oxygen ions surrounding Si and tetrahedral Al sites have highly variable, but strongly interdependent, polarizabilities; however, the O polarizability is almost invariant around octahedral Al sites. The correlation of relaxation energy in a silicate lattice with polarizability is finally compared with the London force interaction between molecules.
Analysis of polymer surfaces by SIMS 1. An investigation of practical problems
Authors: Briggs D. , Wootton A. B.
Published: December 2004

Secondary ion mass spectrometry has the potential for high spatial resolution surface analysis of polymers via fingerprint mass spectra and the use of a focused ion beam. Several problems stand in the way of realizing this potential, namely: (a) the expected high rate of ion beam damage, (b) the need for charge neutralization leading to (c) the uncertainty of surface potential and (d) the possibility of electron stimulated desorption of secondary ions. The importance of these effects have been studied using a model short chain hydrocarbon and films of polystyrene and polytetrafluoroethylene.
Inelastic electron tunneling spectroscopic study of the silane coupling agents: 1—Aminophenyltrimethoxysilane adsorbed on plasma grown aluminum oxide and effects of high humidity
Authors: Furukawa T. , Eib N. K. , Mittal K. L. , Anderson H. R.
Published: December 2004

The adsorption mechanism of aminophenyltrimethoxysilane adsorbed from the vapor on plasma grown aluminum oxide and effects of high humidity on the adsorbed silane were studied by inelastic electron tunneling spectroscopy (IETS). The IETS spectrum of aminophenyltrimethoxysilane contains the bands due to phenyl rings, methyl groups and amino groups. The NH2 deformation mode is shifted to lower frequencies, which may imply that the silane is chemisorbed through the amino group. By exposing the sample to water vapor, the methoxy group hydrolizes and the resultant methanol is removed from the varrier region indicated by a significant loss of intensity of the CH3 stretching and deformation modes. A loss of intensity of the NH2 deformation mode was also observed after the exposure.
On the influence of crater edges and neutral beam component on impurity profiles from raster scanning SIMS
Authors: Vandervorst W. , Maes H. E. , De Keersmaecker R.
Published: December 2004

A mathematical evaluation is presented for the beam raster scanning mode of depth profiling with SIMS, combined with electronic gating of the detection system. A computer program was developed in which a former treatment of the influence of the crater edges is extended to arbitrary impurity profiles and which also accounts for neutral particles in the primary beam. It is shown that these neutrals have a dramatic effect on the obtained dynamic range and that the commonly used background subtraction technique does not necessarily lead to the correct profile. The simulation including neutrals shows good agreement with an experimentally measured profile. Finally, the influence of the crater edges and the choice of an appropriate structure for measuring depth resolution and outdiffusion are discussed.
On the influence of crater geometry on depth resolution of AES and XPS profiles of tantalum oxide films
Authors: Mathieu H. J. , Landolt D.
Published: December 2004

The influence of crater geometry on depth resolution in AES and XPS depth profile analysis was studied using modern apparatus with double cylindrical mirror analyser and a differentially‐pumped ion raster gun. Anodic Ta2O5 films with thicknesses between 3–100 nm served as a model system. Ion and electron beam raster size, beam alignment, ion energy and film thickness were varied. Results show that optimalization of geometrical factors is important for obtaining good depth resolution. Under favourable conditions, depth resolution characterized by the measured apparent width of the metal–oxide interface was found to be as low as 1.5 nm for AES and 2.3 nm for XPS, respectively. Because of impurity adsorption better depth resolution is obtained if analysis and sputtering are carried out simultaneously rather than alternatively.
Analysis of polymer surfaces by SIMS, 3—preliminary results from molecular imaging and microanalysis experiments
Authors: Briggs D.
Published: December 2004

Model studies of heterogeneous polymer surfaces are reported which demonstrate, for the first time, the potential of SIMS for molecular imaging and microanalysis of organic materials. Imaging resolution is essentially limited by the spot size of the ion beam (here to c. 50μm).
Quantitative determination of the kinetics of the reaction of NiO and Al2O3 to NiAl2O4 by Rutherford backscattering
Authors: De Roos G. , Fluit J. M. , Velthuizen R. P. , De Wit J. H. W. , Geus J. W.
Published: December 2004

A quantitative evaluation of RBS data resulted in data for the parabolic reaction rate constants for the reaction between Al2O3 and NiO at temperatures from 960°C up to 1105°C. The activation energy and the preexponential factor were in good agreement with literature data. The experimental data of this work also permitted a detailed description of reaction mechanisms on a microscopic level. The reaction between Al2O3 and NiO starts with penetration of Al3+ ions along the grain boundaries of NiO, followed by counter‐diffusion of Ni2+ ions. A thin spinel layer (NiAl2O4) is formed at the Al2O3/NiO interface, after a relatively short nucleation period. The reaction then proceeds, both by lateral and perpendicular diffusion. In an appendix, the detailed evaluation procedure of the spectra was described.
Monochromatized Ag Lα X‐rays as a source for higher energy XPS
Authors: Yates K. , West R. H.
Published: December 2004

Monochromatization of Ag Lα X‐rays is achieved by fitting an Ag anode to a conventional Al Kα monochromator. Many new XPS lines are generated by this high energy source including the 1s and KLL Auger series from Al to Cl. Chemical state determination by means of the Auger parameter for these elements is greatly assisted by the reduced X–ray linewidth after monochromatization. Three glass fibre samples with different surface pre‐treatments were studied to show that chemical state information could be extracted from even these complex, rough and insulating surfaces by using this novel X‐ray source.
Calibration of an X‐ray photoelectron spectrometer by means of noble metals
Authors: Ebel Maria F. , Ebel H. , Zuba G. , Wernisch J.
Published: December 2004

A review of the literature concerning binding energies of noble metal core levels has been carried out. From this data values for energy calibration in electron spectroscopy are recommended.