bluuebunny/crossref_metadata_2025_split huggingface dataset:
Modified SDM Model for the Calculation of shaped charge hole profiles
Authors: Schwartz Wolfgang 
Published: December 2004

AbstractShaped charge craters can be calculated in regards to depth and diameter profile using the SDM model named after Simon, DiPersio, and Merendino(3). Crater profiles calculated using the SDM formulae exhibit a systematic deviation if compared with test data from firings of certain MBB (now DASA) shaped charges into RHA.The calculated craters feature a significantly more trumpet‐shaped profile than the measured holes in RHA This phenomenon is caused, at least partly, by the assumption in the SDM model that the break‐up time and the jet diameter after break‐up are constant. Radiographs of particulated jets provide evidence that the diameter is generally not constant, rather increases from tip to tail. The evaluation of such radiographs also leads to the conclusion of variable break‐up times.Changing those two assumptions a modified set of SDM formulae was developed so that calculated and experimental crater profiles are in better agreement for the above mentioned MBB shaped charges.
Impact Testing of Explosives and Propellants
Authors: Coffey C. S. , De Vost V. F. 
Published: December 2004

AbstractThe drop weight impact test is the simplest and easiest test that can be performed on small quantities of explosives or propellants, and yet it has only a minimal role in assessing explosive sensitivity or performance. This paper examines the drop weight impact test as it is currently used, describes its major flaw, and suggests an alternative test that holds the promise of providing the impact energy required to ignite an energetic material. Other impact tests are described. One of these, the Ballistic Impact Chamber Test, measures the rate of reaction and extent of reaction during impact. This test demonstrates that during impact there are two forms of initiation reactions that occur, one that is very fast and is likely due to direct impact‐shear initiation of the crystalline solids in the sample. The other, a much slower component, is thought to arise due to burning of the sample.
Preheating Sensitization of a TATB Composition. Part Two: Microstructure Evolution
Authors: Le Gallic Christian , Belmas Robert , Lambert Philippe 
Published: December 2004

AbstractThis paper is devoted to a review of microstructure observations performed on a TATB composition submitted to thermal and combined thermal/mechanical stimuli. Effects are identified and quantified in terms of decomposition extension and microstructure evolution (porosity, shear bands, grains shape and orientation, anisotropy …︁). Several complex mechanisms and important transformations are exhibited as a function of temperature, heating duration and shock wave intensity. Conclusions on decomposition mechanisms are directly derived from these observations.
Study of Jet Interaction with Interlayer Material of Bulging Armor
Authors: Yadav H. S. 
Published: December 2004

AbstractThe paper presents an analytical approach for determining the effects of different properties of inert material of bulging armor sandwich on its efficiency against a shaped charge jet. The crater and shock wave parameters have been investigated. A theoretical relation for calculating the energy of the shock wave, produced by the jet impact, in the inert material has been derived on the basis of continuity of pressure and particle velocity at the interface of jet and inert material. This relation reveals that the higher the velocity of the jet the greater is the amount of energy in the shock wave. The energy of the shock wave also increases with increase of density and decrease of strength of the inert material. The shock energy has been found to further depend on the constants of equation of state of the inert material, (us=a+b u).
Aspects of the Tribology of the Plastic Bonded Explosive LX‐04
Authors: Hoffman D. Mark , Chandler Jeffrey B. 
Published: December 2004

AbstractThe dynamic coefficient of friction, μd, of the plastic bonded explosive (PBX) LX‐04 was measured on stainless steel, aluminum, Teflon and the explosive itself as a function of temperature between ambient and 135 °C at a rotational speed of 0.0025 rad/s−1. An optical profilometer was used to analyze surface roughness. LX‐04 is a composite of the explosive 1,3,5,7‐tetranitroazacyclooctane (HMX) and Viton A in an 85/15 weight ratio. For LX‐04 on stainless steel, μd decreased from 0.38 at ambient to 0.18 at 95 °C, then was nearly constant to about 125 °C, where the coefficient began to increase again. The opposite behavior was observed for aluminum. Against Teflon μd was nearly constant from ambient to 65 °C at 0.43, and then decreased to 0.17 from 100 °C to 135 °C. Against LX‐04 itself the coefficient of friction averaged 0.64 at temperatures between 35 °C and 95 °C, but tended to increase during the measurement, probably due to adhesion of the Viton to itself. Above 95 °C the coefficient dropped off and became nearly constant again at 0.16 up to 135 °C. Measurements on stainless steel with the mock explosive RM‐04‐BR, a composite of cyanuric acid and Viton A, and with the same weight ratio as the actual explosive, compared reasonably well with the explosive itself.
Neutralization of NGF‐TrkA receptor interaction by the novel antagonistic anti‐TrkA monoclonal antibody MNAC13: A structural insight
Authors: Covaceuszach Sonia , Cattaneo Antonino , Lamba Doriano 
Published: December 2004

AbstractMNAC13, a mouse monoclonal antibody, recognizes with high affinity and specificity the neurotrophin receptor TrkA and displays a neutralizing activity toward the NGF/TrkA interaction. Detailed knowledge of the molecular basis determining the specificity of this antibody is of importance because of its potential use as a modulator of the TrkA‐mediated NGF activity. Here, we report a full biochemical and structural characterization of the MNAC13 antibody. Epitope mapping studies, by serial deletion mutants and by phage display, reveal a conformational epitope that is localized on the carboxy‐terminal region of the first immunoglobulin‐like domain (d4) of TrkA. The X‐ray crystal structure of the MNAC13 Fab fragment has been determined and refined to 1.8 Å resolution. The antigen‐binding site is characterized by a crevice, surrounded by hydrophilic‐charged residues on either side, dipping deep toward three mainly hydrophobic subsites. Remarkably an isopropanol molecule has been found to bind in one of the hydrophobic crevices. Overall, the surface topology (shape and electrostatic potential) of the combining site is consistent with the binding data on TrkA ECD serial deletions mutants. The structure of the MNAC13 Fab fragment may assist in the rational structure‐based design of high affinity humanized forms of MNAC13, appropriate for therapeutic approaches in neuropathy and inflammatory pain states. Proteins 2005. © 2004 Wiley‐Liss, Inc.
Acaricide mode of action
Authors: Dekeyser Mark A 
Published: December 2004

AbstractThe last few years have seen the introduction of an unprecedented number of new classes of acaricides with novel or under‐exploited modes of action, discovered by traditional screening. Acaricide research has uncovered several unrelated compounds that possess improved properties. Pyridaben, acequinocyl, diafenthiuron, etoxazole, spirodiclofen and bifenazate, in particular, are acaricides that are safe to beneficials, have low mammalian toxicity and short environmental persistence. Many of the new acaricides appear to affect mitochondrial respiration, and previously unknown targets affecting mite growth and development have been identified, offering new opportunities for mite control. Copyright © 2005 Society of Chemical Industry
On the preparation of electron sensor using LiRbSO4 samples
Authors: El‐Muraikhi M. , Kassem M. E. , Gaafar M. , Abdel Gawad M. M. H. , Ragab I. M. 
Published: December 2004

AbstractThe dielectric spectroscopy of metal–metal sulfate LiRbSO4 samples are described with particular emphasis on sensor performance to be used in the field of radiation. The obtained results as the effect of different electron energy beams at fixed dose, 0.5 Gy, showed abrupt change of the electrical properties (electrical conductivity, capacitance, and loss tangent). The results can be explained on the basis of radiation‐induced defects followed by radiation quenching. The prepared samples can be used in the field of radiation dosimeter.
Microwave‐assisted Cu (I) Catalyzed Solvent‐free Three Component Coupling of Aldehyde, Alkyne and Amine
Authors: Ju Yuhong , Li Chao‐Jun , Varma Rajender S. 
Published: December 2004

AbstractDirect Grignard type addition of terminal alkynes to in situ generated imines, from aldehydes and amines, occurs under microwave irradiation using CuBr alone in a one‐pot operation. This solventless approach provides ready access to propargylamines and is applicable both to aromatic and aliphatic aldehydes.
Thickness measurements on layered materials in powder form by means of XPS and ion sputtering
Authors: Cross Y. M. , Dewing J. 
Published: December 2004

AbstractA model for the quantitative analysis of XPS data from coated spherical particles is described. The limitations of the application of flat surface intensity equations to this system are discussed. The predictions are compared with experimentally derived XPS results for SiO2O3 coated TiO2 powder samples. Sputtering profiles for these systems are presented and interpreted.
Auger electron spectroscopy (AES) an appraisal
Authors: Alford N. A. , Barrie A. , Drummond I. W. , Herd Q. C. 
Published: December 2004

AbstractElectron induced Auger electron spectroscopy of solid surfaces has proved a valuable analytical technique over the past ten years. In this paper the state of the technique is reviewed and compared with other methods of Auger spectroscopy, e. g. X‐ray induced AES.
A multichannel electro‐optical detector for rapid acquisition of X‐ray photoelectron spectroscopy data
Authors: Ceasar G. P. , Weber J. , Talmi Y. 
Published: December 2004

AbstractAn electro‐optical detector easily adaptable to any hemispherical sector photoelectron spectrometer is described. The detector consists of a channel plate electron multiplier array, phosphor screen, silicon intensified target vidicon an optical multichannel analyzer control unit. Data collection rates are improved by more than two orders of magnitude over conventional single channel detectors.
A total current spectroscopy study of the growth of thin metal and semiconductor surface layers
Authors: Komolov S. A. , Chadderton L. T. 
Published: December 2004

AbstractExperiments are described in which thin layers of silver and gold, and of cadmium sulphide and cadmium selenide, have been grown on metal substrates in ultra‐high vacuum. Total current spectroscopy (TCS) reveals details of the film formation processes until, finally, the spectrum obtained can be related to inelastic electron/electron scattering accompanied by interband transitions in the continuous overlayer. An analysis is presented which permits extraction of values for effective of values for effective mean free paths for different electron energies in the evaporated films.
Quantitative auger electron spectroscopy: Modulating the spectrometer
Authors: Seah M. P. 
Published: December 2004

AbstractAs part of an on‐going programme at the National Physical Laboratory on the quantification of surface spectroscopies, it is shown that, in using the modulation technique for quantitative Auger electron spectroscopic analysis in the differential mode, care must be taken in applying the modulation. With the complex electron spectrometers now being employed for combined X‐ray photoelectron and Auger spectroscopic work, error signals can be added into the spectra by several of the proposed systems of modulation. The error signals are analysed quantitatively and are shown to be important at energies below 200 eV. Similar error signals can be found in the case of the cylindrical mirror analyzer. To obtain the correct derivative spectrum care must be taken to modulate the whole electron spectrometer with AC levels in strict proportionality to the incremental DC changes appropriate to each of the electrodes.
A high pressure preparation lock for surface analysis
Authors: Polaschegg H. D. , Jungel A. , Schirk E. 
Published: December 2004

AbstractA lock will be described that facilitates the preparation of samples in a small high pressure preparation chamber at pressures up to 30 bar (30 atm) and temperatures up to 800°C and the transport of the treated sample into the analysis chamber, which is under UHV, without reducing the pressure in the preparation chamber.
Surface characterization and adhesive bonding of stainless steels: I—the surface characterization of the steels
Authors: Gettings M. , Kinloch A. J. 
Published: December 2004

AbstractIn part I of this study, surfaces of three stainless steels have been characterized by scanning electron microscopy, electron probe microanalysis, Auger electron spectroscopy and X‐ray photoelectron spectroscopy. The surface characteristics, which were investigated before and after chemical etching, were found to be strongly dependent upon the method of steel manufacture. The environmental resistance of adhesive joints prepared using the steels depended upon the surface chemistry and roughness induced by the etching treatment. In part II the interface region of the three steels and silane‐based primer will be analysed and results correlated with durability studies.
Quantitative ESCA surface analysis applied to catalysts: Investigation of concentration gradients
Authors: Finster Joachim , Lorenz Petra , Meisel Armin 
Published: December 2004

AbstractESCA intensity measurements for quantitative surface analysis can give more information than the average composition in the surface region, e.g. for substances which possess a concentration gradient vertical to the surface. This concerns almost all samples which were subject to solid‐state surface reactions, among them frequently also supported catalysts. Enrichment factors Γ (that is, the measured intensity ratio compared with the ratio corresponding to the stoichiometric composition of the sample) are introduced and calculated for an exponential concentration–depth profile by convolution with the exponential attenuation law for photoelectrons. The two characteristic parameters in a two‐component system (surface concentration x0 and profile parameter n) can be determined independently only by the measurement of two or more Γ values for one sample, varying either the escape angle or the escape depth of photoelectrons. We used the latter method and measured besides the Ni 2p/Si 2p intensity ratios also the Ni 2p/Ni 3p intensity ratios of a series of NiO/SiO2 catalysts. The application of this kind of depth profiling to high surface area substances (an enrichment of one components in the outer region is necessarily connected with a depletion of the same component in deeper regions) complicates the deduced equations and needs further model considerations. We determined the characteristic parameters of the Ni concentration gradient in these catalysts and from them calculated the most important first layer composition. In combination with the analysis of ESCA line positions and shapes and in agreement with the results of other measurements, we were able to set up a model of the catalyst surface structure.
The study of radiation‐induced chemical damage at solid surfaces using photoelectron spectroscopy: A review
Authors: Copperthwaite Richard G. 
Published: December 2004

AbstractAfter a short summary of the main processes occurring in an ionic solid during the absorption of radiation, the advantages of photoelectron spectroscopy in the study of the chemical consequences of such processes are summarized. A critical survey of the published work in this field is then undertaken, together with an assessment of future possibilities and applications.
X‐ray photoelectron study of thin evaporated films of Fe/Ni alloy
Authors: Nefedov V. I. , Pozdeyev P. P. , Dorfman V. F. , Pypkin B. N. 
Published: December 2004

AbstractThin evaporated films of Fe/Ni alloy on a SiO2 substrate were studied by means of ESCA. Depth‐composition profiles during ion sputtering and angular dependences of peak intensities upon take‐off angle of electrons were measured. The calibration curve for the ratio of intensities IFe 3p/INi 3p vs. bulk alloy composition was plotted. The uppermost layer of the film at the air/FeNi interface was enriched with Fe oxides. The next layer was slightly depleted of Fe atoms. At the FeNi/SiO2 interface the relative Fe and Ni content was the same as in the bulk of the film down to the layers of no more than 10 Å thickness. The approach to SiO2 during sputtering of the last thin layers of the film was accompanied by formation of charged Fe/Ni alloy islands on SiO2 which led to splitting of the Fe, Ni, Si, O and C lines. The width of the FeNi/SiO2 transition zone created by ion bombardment was about 35–50 Å for films of 100–200 Å thickness.
The energy dependence of the electron mean free path
Authors: Wagner C. D. , Davis L. E. , Riggs W. M. 
Published: December 2004

AbstractExperiments providing multi‐point data on electron mean free paths vs. energy in pure materials have been reviewed for energies from 150 to 4000 eV. With the assumption that the simple equation λ=kEm can approximate the data, one obtains values of m between 0.53 and 0.80. Observations by ESCA of widely spaced photoelectron lines for Mg, Cu, Zn, Ga, Ge and As also lead to the conclusion that the exponent is considerably larger than 0.5, and is more likely in the range 0.65‐0.75.
ISS/SIMS characterization of mica surfaces
Authors: Baun W. L. 
Published: December 2004

AbstractSIMS and ISS are used to characterize mica surfaces. The results on matching cleaved surfaces show that cleavage occurs along the potassium layer and the potassium ions are shared equally between the separated surfaces. A comparison of these freshly cleaved surfaces with original weathered surfaces shows large differences in the potassium content just at the surface. A mechanism of oxidation or chemisorption of water is suggested. Other ISS/SIMS data from treated mica surfaces show a high sensitivity for small chemical changes which take place on these surfaces. The experiments indicate that the ISS/SIMS technique should prove very useful for diffusion studies through thin films using mica surfaces.
Crater edge profling of Ni/Cr sandwich multilayer thin films by scanning Auger microscopy (sam)
Authors: Zalar A. , Hofmann S. 
Published: December 2004

AbstractThe principle of the technique of crater edge profiling is described as an alternative method to conventional sputter profiling. The predictions for the lateral composition profile assuming a Gaussian intensity distribution of the primary ion beam are tested for a multilayer sandwich structure of Ni/Cr layers of 11.5 nm single layer thicknesses after Ar+ ion sputtering through 20 layers and scanning Auger microscopy with a 10 µm diameter electron beam. Due to the small angle of 44.3″ of the slope of the crater formed by ion sputtering, a magnification factor (lateral variation/depth variation) of 5 × 103 is obtained.
Shading at different take‐off angles in X‐ray photoelectron spectroscopy
Authors: Ebel Maria F. , Wernisch J. 
Published: December 2004

AbstractResults of quantitative X‐ray photoelectron spectroscopic analysis are influenced by thin overlayers. Therefore, the reduced thickness of these layers has to be determined to allow a compensation to be made for this influence. An applicable method is based on the variation of the take‐off angle. In this paper the angular dependence of the photoelectron count rate caused by surface roughness is discussed. It is created mainly by X‐ray shading. As a consequence of these considerations the ultimate roughness depth can be given up to where the angular response of the count rate is not affected by X‐ray shading and thus the method of the variable take‐off angle can be applied.
XPS studies of a ferricyanide accelerated chromate paint pretreatment film on an aluminium surface
Authors: Treverton J. A. , Davies N. C. 
Published: December 2004

AbstractAn XPS analysis of a ferricyanide accelerated chromate paint pretreatment film found iron in the form of both a ferricyanide and a ferrocyanide ion. Chromium occurred in at least two different chemical environments, one of which was as a hydrated oxide. Aluminium and fluorine probably occurred together although the analysis was not conclusive in this respect. More positive evidence is available elsewhere. The behaviour of the elements on ion etching was consistent with a model of the film comprised mainly of hydrated chromium oxide microcrystallites covered with a monolayer of ferricyanides. Escape depth calculations and correlation of semiquantitative analysis with chemical and energy‐dispersive analyses of the film were also consistent with this model. Adsorption of ferricyanides on the surface of the precipitating particles of the growing film provides an explanation for their role as accelerators of film growth.
Determination of the centroid depths of shallow impurity profiles by X‐ray fluorescence spectrometry
Authors: Gries W. H. , Wybenga F. T. 
Published: December 2004

AbstractA method is presented for the non‐destructive determination of centroid (mean) depths of shallow standard profiles (ion implanted, diffused, square) of dopant impurities in lighter materials by comparative X‐ray fluorescence measurement at different take‐off angles. The method is based on an analytical expression which links the ratio of two fluorescence signals to the distribution moments of the impurity profile. It is also shown how this method can be used for the identification of unknown standard profiles as well as for the determination of p–n junction depths in Si wafers.
Practical peak area measurements in X‐ray photoelectron spectroscopy
Authors: Bishop H. E. 
Published: December 2004

AbstractAn assessment of the reliability of peak area measurements using the simple linear background subtraction approach has been made by comparing the results obtained by a number of workers from a set of simulated spectra mixing the Fe 2p peaks from Fe metal and Fe2O3. The simulated spectra are generated from Gaussian peaks with a step background similar to that of Shirley, but modified to reproduce the sloping background on the low kinetic energy side of the peak. The results show that systematic errors in the total area of the Fe 2p peak may be as great as 40% using the workers best estimate of the background line. An alternative approach involving the areas of both 2p3/2 and 2p1/2 peaks reduces this error to 17%.
An asymmetric model for XPS analysis
Authors: Dunn William L. , Dunn Terry S. 
Published: December 2004

AbstractThe process of determining the overlapping peaks in complex X‐ray photoelectron spectra of polymer surfaces is posed mathematically as an inverse problem whose solution can be reduced to a standard least‐squares procedure. Various models can be generated by assuming specific forms for the distribution of effective binding energies corresponding to photoelectron kinetic energies and for the spreading kernel characteristic of the spectrometer. A particular generalized asymmetric model is developed for monochromatic X‐ray photoelectron spectroscopy of polymer surfaces based on physically meaningful electron energy loss characteristics and assuming the spreading kernel to possess both Gaussian and Lorentzian forms. Computer fits to experimental X‐ray photoelectron spectra indicate that the asymmetric model and curve‐fitting procedures employed offer an effective and flexible means for analyzing X‐ray photoelectron spectra.