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The efficacy of wood dust fibre treatment on the property of wood dust reinforced recycled polypropylene composite (r-WoPPC) filament was investigated. The wood dust fibre was treated using alkali, silane, and NaOH-silane. The treated wood fibre was incorporated with r-PP using a twin-screw extruder to produce filament. The silane treatment on wood dust fibre enhances interfacial bonding between wood fibre and recycled PP; hence, a filament has the highest wire pull strength, which is 35.2% higher compared to untreated and alkaline-treated wood dust filament. It is because silanol in silane forms a siloxane bond that acts as a coupling agent that improves interfacial bonding between wood dust fibre and recycled PP. The SEM micrograph of the fracture structure reveals that treated silane has strong interfacial bonding between wood dust fibre and recycled PP, having minimal void, gap, and good fibre adhesion. The water absorption test results indicate that filament with treated wood dust absorbs less water than filament with untreated wood because the treatment minimizes the gap between wood fibres and recycled PP. The FTIR analysis identified the presence of silane on the wood dust surface for silane-treated wood dust. The DSC studies suggest that the temperature range 167–170 °C be used in the extrusion machine to produce r-WoPPC filament. As a result, r-WoPPc filaments containing silane-treated wood dust have better mechanical properties and have a greater potential for usage in FDM applications.

Customer care plays an important role in a company especially in managing churn for Telecommunication Company. Churn is perceived as the behaviour of a customer to leave or to terminate a service. This behaviour causes the loss of profit to companies because acquiring new customer requires higher investment compared to retaining existing ones. Thus, it is necessary to consider an efficient classification model to reduce the rate of churn. Hence, the purpose of this paper is to propose a new classification model based on the Rough Set Theory to classify customer churn. The results of the study show that the proposed Rough Set classification model outperforms the existing models and contributes to significant accuracy improvement. Keywords : customer churn; classification model; telecommunication industry; data mining; rough set.

Thin films of aluminum were exposed in short increments to a plasma environment using a semiconductor plasma asher. The process gas was a mixture of air and oxygen. The total exposed oxygen fluence was 1.2 × 10 21 oxygen atoms cm −2 accumulated over 34 h. Heavy contamination of film surfaces resulted from plasma etching of the chamber seals. The surface microstructure of this deposited contaminant was studied with atomic force microscopy (AFM). The contaminants appear to nucleate and grow at protruding surface features. These features appear in the AFM data as dome-shaped growths rising rapidly from the surface. The density of these observed growths is much higher on sputtered films than on electron-beam evaporated films. These differences are most likely due to the microstructure of the as-deposited films. The as-deposited sputtered films are rougher than their evaporated counterparts and provide more sites for nucleation of the observed contaminant growths. The surface roughness of the contaminated films increases quickly by a factor of 3–6 within 300 min of exposure and saturates thereafter. It is postulated that the surface roughness increases until a continuous, but rough, contaminant layer is formed. After the formation of a continuous layer, additional material deposits while maintaining the existing surface microstructure. The growth of rough contaminant features has a significant effect on the specular reflectance of the films. Sputtered films show larger losses in specular reflectance than evaporated films after asher exposure.

To study the effects of Atomic Oxygen on various thin film materials, fourteen thin film samples were exposed to the corrosive environment of low Earth orbit. Total exposure was 42 hours, resulting in a nominal atomic oxygen fluence of 2.2 X 1020 atoms/cm2. The films included aluminum, diamondlike carbon, diamond, and multilayer stacks. Included are experimental details of sample preparation, exposure, and post-flight results. Pre-flight characterization techniques included Variable Angle Spectroscopic Ellipsometry, optical reflectance and transmittance, Atomic Force Microscopy, and Raman scattering. Post-flight analysis repeated pre-flight characterization. Aluminum films resisted degradation. Surface contaminants were identified using Auger Electron Spectroscopy. Contaminants were SiC>2, fluorine, and sulfur which most likely result from degradation of cargo bay lining, waste water dumps, and outgassing. Diamondlike carbon films were completely etched away during exposure. Polycrystalline diamond films were extremely resistant to atomic oxygen degradation, showing no post-flight structural, compositional, or mass changes. Aluminum films 23.5 nm thick simultaneously protect silver reflecting layers from oxidation and increase the ultraviolet reflectance of the stack. Decreasing the aluminum thickness to 7.5 nm resulted in complete oxidation during exposure and failure as a protective coating.

In situ spectroscopic ellipsometry (SE) covering the spectral range from 280 to 1000 nm was performed during RF bias assisted electron cyclotron resonance (ECR) etching of SiO 2 , GaAs oxide, silicon, and GaAs by a CCl 2 F 2 /O 2 mixture. The etch rate of SiO 2 /Si samples as a function of RF bias power, and total pressure was then measured, in situ, for a constant ECR power of 175 W, and CCl 2 F 2 /O 2 flow rate ratio of 1 3 by performing SE at selected wavelengths most sensitive to changes in SiO 2 thickness. A wide range of etch parameters can be investigated without changing samples by employing a relatively thick SiO 2 layer. This allows rapid optimization of the etch parameters, and can also provide accurate endpoint detection in the face of a time-dependent etch rate. Ellipsometric monitoring of bulk silicon and GaAs samples cannot provide in situ etch rates, however, insight into the etch mechanism may be gained by observing the effect of the etch process on the native oxide layer, surface roughness, and in the case of GaAs, on the surface stoichiometry.

Using variable angle spectroscopic ellipsometry and atomic force microscopy (AFM), the surface roughness and oxidation of aluminum and titanium thin films have been studied as a function of substrate deposition temperature and oxygen plasma exposure. Increasing substrate deposition temperatures affect film microstructure by greatly increasing grain size. Short exposures to an oxygen plasma environment produce sharp spikes rising rapidly above the surface as seen by AFM. Ellipsometric measurements were made over a wide range of plasma exposure times, and results at longer exposure times suggest that the surface is greater than 30% void. This is qualitatively verified by the AFM images.

The motivation for this work was to develop in-situ monitoring and control of electron cyclotron resonance (ECR) as an anisotropic etch doing minimal surface damage to electronic materials. We have used a modular rotating- analyzer spectroscopic ellipsometer in both the in-situ and ex-situ modes to investigate etching of Si, SiO2, GaAs and InP, as well as GaAs/Al1−xGaxAs/GaAs and InP/In1−xGaxAs heterostructures. Etching was done using a 175 W ECR source with mixtures of CCl2F2 and either oxygen or insert gases in various flow ratios in order to prevent polymerization. The experimental variables in these experiments were the gas ratios, gas species, r.f. substrate bias voltage (power) and substrate temperature. Etching was found to create a thin damage region near the surface modeled ellipsometrically as crystalline-plus-amorphous semiconductor in a Bruggeman effective-medium mixture.

The magnetic properties of Co/Cu multilayers were investigated from 5 to 380 K and analyzed in terms of the interface magnetism and mean‐field model. The interface, which is about 1.2 A thick, is nonmagnetic at room temperature and becomes magnetic at 5 K with the average magnetization of 40% of the pure Co magnetization. The samples of X A Co/10 A Cu behaved superparamagnetically as X ranged from 4 to 6.5 A and did not show superparamagnetic behavior for thinner or thicker Co layer thickness.

Nanostructured Co/Ag composite films were prepared by magnetron sputtering using a single target. The average crystallite sizes of Co and Ag in the films depend on the deposition conditions. As the substrate temperature increases from 100 °C to 600 °C, the average Ag crystallite size increases from 39 to 452 A, and the average Co crystallite size increases from

Co/Cu and Co/Si multilayers of total thickness ∼3000 A were prepared by rf and dc magnetron sputtering. The nominal thicknesses of the individual layers were in the range of 4 to 100 A. A large coercivity (Hc) at 10 K was observed for very thin layers of Co in Co/Cu samples, and it decreased with increase of the Co layer thickness. For very thin layers of Co in Co/Cu samples, the layer behaved superparamagnetically. Similar behavior was not to be observed in Co/Si samples. With increased substrate temperature (Ts) during deposition, Hc was also observed to increase (decrease) for Co/Cu (Co/Si) samples. Magnetization data were modeled to determine the diffusion layer thicknesses.

Thin Co/Pt multilayers were prepared on Si and glass substrates by sputtering with Ar pressures ranging from 2.5 to 15 mTorr. The bilayer structure of the samples was Co(3 A)/Pt(15 A)×17, and all samples had the easy axis of magnetization perpendicular to the sample surface as determined with a SQUID magnetometer. All samples retained the layered structure, as revealed by low‐angle x‐ray diffraction. In addition, diffraction peaks due to the formation of Co‐Pt compounds (presumably at the interfaces between Co and Pt) were identified. The coercivity of samples changed from about 400 Oe for films deposited at low Ar sputtering pressure (2.5 mTorr) to as high as 2300 Oe for films deposited at high Ar pressure (15 mTorr). Ellipsometry and atomic force microscopy were used to study surface roughness and microstructure of samples prepared at different sputtering pressures.

Amorphous Tb/Co compositionally modulated films were deposited on Si substrates with different modulation layer thicknesses ranging from about 2.5 to 15 A. The nominal Tb to Co layer thickness ratios were systematically varied and the complex refractive index (n and k) and polar magneto‐optical Kerr effects (rotation and ellipticity) were measured in the 3000–8000‐A spectral range as well. The samples were divided into two groups. In one group, the thickness of the Co layers was fixed, the Tb layer thickness varied. In the second group, the thickness of the Tb layer was fixed, and that of the Co layer thickness varied. The Kerr rotation and the coercivities of the samples showed very consistent and interesting changes. X‐ray diffraction and x‐ray fluorescence were also performed on the samples, which revealed layered structures, or compositional modulation, and provided information on the Tb to Co atomic ratios in the samples.

Ultrafine Fe‐Ni‐B particles were synthesized by reducing iron and nickel salts with NaBH4 in aqueous solutions. The particles had diameters in the range of 100–300 A. X‐ray diffraction patterns showed that particles with boron concentration 18 at. % or more were amorphous; otherwise they were crystalline. It was also found that the amorphous particles contain less than 50 at. % of Fe. The coercivity of Fe‐B particles was increased by an addition of a small amount of Ni to the system. The room‐temperature coercivity and saturation magnetization for particles of composition Fe63Ni24B13 and of diameter 100 A were 1275 Oe and 70 emu/g, respectively.

In situ ellipsometry at selected wavelengths in the spectral range 280 nm to 1000 nnn was performed during the rf bias assisted electron cyclotron resonance (ECR) etching of bulk silicon, GaAs, InP, and GaAs/AlGaAs/GaAs, and InGaAs/InP layered strcutures by a CCl2F2 based etch gas.While real time thickness changes for bulk materials cannot be determined ellipsometrically, some insight into the etch mechanism may be gained by observing the effect of the process on the surface dynamically, and after the etch process has been completed. Monitoring of the layered structures during etching can provide a real time measure of the amount of material remaining in the layer being etched, and provide tight process control.

CVD deposited diamond-like carbon (DLC) films have been studied for possible use as a secondary standard for Low Earth Orbit materials degradation. Samples of various thicknesses have been exposed to a simulated Low Earth Orbit atomic oxygen (AO) environment using a plasma asher. Mass loss measurements indicate that DLC degrades at a rate of 0.7 mg/hr which is two to three times the rate of currently used Kapton samples which degrade at a rate of.3 mg/hr. Thickness measurements show that DLC thins at a rate of 77 Angstroms/min. Since DLC is not as susceptible to environmental factors such as moisture absorption, it could potentially provide more accurate measurements of AO fluence on short space flights. Adhesion of DLC films to both fused silica and crystalline silicon substrates has been studied under thermal cycling conditions. Film adhesion to fused silica can be enhanced by sputtering a thin layer of silicon dioxide onto the substrate prior to deposition. In addition to the above, the index of refraction and extinction coefficient of various thicknesses of DLC films has been characterized by Variable Angle Spectroscopic Ellipsometry.

Several aspects of the magnetic transitions seen in rare‐earth metallic glasses are discussed, particularly with reference to recent theoretical work. These include: (a) apparent double transitions observed in Gd glasses where exchange fluctuations are important, (b) evidence for a correlated speromagnetic state recently predicted by Chudnovsky and Serota, and (c) the analysis of a Tb glass with strong random anisotropy in terms of an Ising‐type spin‐glass transition.

Etude de Nd 15 Fe 77 B 8 , SmCo 5 , Sm 2 (Co, Fe, Cu, Zr) 17 , des aimants a ferrite de strontium et de particules monodomaines de ferrite de Ba et de Cu-Mn-Al. Mesure des courbes d'aimantation initiale, de la variation avec le champ de la coercivite et des courbes de remanences

The magnetic properties of fine Fe-B particles with different boron concentrations and particle sizes were studied. The powders were prepared by reducing Fe-salts with NaBH/sub 4/ as a reducing agent in aqueous solution. The particle size ranged from 300 to 600 AA. X-ray diffraction patterns show that the particles are crystalline for boron concentrations less than 20 at.% and amorphous for greater concentrations. The maximum coercivity and saturation magnetization obtained for these particles are approximately 1200 Oe and 160 emu/g at room temperature. The coercivities are about two orders of magnitude higher than the values reported for Fe-B metallic glasses and alpha -Fe. >

Measurements are reported on the relationship between magnetic properties and microstructure in thin amorphous and crystalline Fe/Nd multilayer films. The samples, denoted by (XAFe/YANd)≡(X/Y), were prepared in a multiple‐gun sputtering chamber with a microprocessor‐controlled rotating table. For X and Y values less than about 20 A an amorphous compositionally modulated structure is obtained, with magnetic properties characterized by speromagnetic ordering associated with strong Nd random anisotropy. The net magnetization in general lies in the plane of the film. The temperature and composition dependence of the coercivity, magnetization, and transition temperatures are discussed.

Barium ferrite fine particles have been synthesized from ferric nitrate and barium nitrate aqueous solution by an aerosol technique. The as-received particles showed a spin-glass behavior with a history-dependent low-field magnetization below 180 K. An exothermic peak with an initial crystallization temperature of 687 degrees C was found by DSC (differential scanning calorimetry) analysis. Heat treatments above this temperature greatly changed the magnetic properties and morphologies without changing the Ba/Fe atomic ratio, which was 1/12. Heat-treated samples had coercivities and saturation magnetizations as high as 5360 Oe and 70.6 emu/g, respectively. >

A study of compositionally modulated magnetic films of the form Fe/RE, particularly for RE=Nd and Dy, has been performed by vibrating sample magnetometry, ac susceptibility and x‐ray diffraction. The relationship between the magnetic properties and the layer thickness was studied systematically for X‐A Fe/Y‐A Dy, as the layer thicknesses X and Y were varied from 1.8 to 20 A. The ranges of layer thicknesses required for perpendicular anisotropy were determined. The interface and volume anisotropy energies were estimated for X‐A Fe/Y‐A Nd and the differences in the magnetic properties between X‐A Fe/7‐A Dy and X‐A Fe/7‐A Nd are discussed.

The generality and universality of the Ising spin‐glass‐like phase transitions observed in several rare‐earth, random‐anisotropy magnets are discussed. Some uncertainties and practical problems in determining critical exponents are considered, and a comparison is made to insulating spin glasses and crystalline spin glasses where an apparent anisotropy‐induced crossover from Heisenberg to Ising‐like behavior is seen. The observation of a reentrant transition in a weak anisotropy system and its correlation with the theory of Chudnovsky, Saslow, and Serota [Phys. Rev. B 33, 251 (1986)] for the correlated spin glass is discussed.

The magnetic and structural properties of fine iron and iron‐oxide particles have been studied. The samples of iron oxide were prepared by the aerosol method and those of pure iron were prepared by the vapor deposition technique. Electron micrographs showed the size of aerosol particles to be 200 nm and that of vapor deposition particles to be 10–20 nm. The maximum coercivity at 10 K obtained for aerosol particles was approximately 700 Oe, and for vapor deposited particles it was 1540 Oe.

The character of the magnetic transition is studied for a magnetic glass with strong random-anisotropy and ferromagnetic interactions. Field-dependent ac susceptibility measurements are presented near the ordering temperature of ${\mathrm{Tb}}_{64}$${\mathrm{Fe}}_{20}$${\mathrm{Ga}}_{16}$. The data are analyzed with a scaling theory for the singular susceptibility. An excellent collapse of the $H$, $T$ data is obtained for reduced temperatures in the range 0.002-0.13. These results, which are compared with recent theoretical work, provide strong evidence for a true phase transition in a random-anisotropy system.

AC susceptibility data taken in various dc applied fields are reported for a-Dy 60 Fe 30 B 10 . Strong random magnetic anisotropy produces a sharp speromagnetic transition to a spin-glass-like state at T f = 91.5 K. The data are analyzed in terms of an Ising-type spin-glass transition, and comparisons are made to related random systems.