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Influence of annealing and bulk hydrogenation on lifetime limiting defects in nitrogen doped floating zone silicon

Influence of annealing and bulk hydrogenation on lifetime limiting defects in nitrogen doped floating zone silicon

Abstract—A recombination active defect is found in as-grown high-purity floating zone n-type silicon wafers containing grown-in nitrogen. In order to identify the properties of the defect, injection- dependent minority carrier lifetime measurements, secondary ion mass spectroscopy measurements, and photoluminescence lifetime imaging are performed. The lateral recombination center distribu- tion varies greatly in a radially symmetric way, while the nitrogen concentration remains constant. The defect is shown to be deac- tivated through high temperature annealing and hydrogenation. We suggest that a nitrogen-intrinsic point defect complex may be responsible for the observed recombination.

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Effect of Floating Zone Refining under Reduced Hydrogen Pressure
on Copper Purification

Effect of Floating Zone Refining under Reduced Hydrogen Pressure on Copper Purification

Furthermore, Appendix B suggests that, even if small amounts of Al and Si were present as the solid solution in the copper starting material, floating zone melting under a slight oxidizing atmosphere for the first several passes could be available for converting them to insoluble oxides by in- ternal oxidation. Thus, these oxides would be removed as a slag layer on the surface of the molten zone, as observed in this work. After that, the remaining impurities such as oxy- gen and some metallic elements could be reduced to very low levels by FZR under a reduced hydrogen pressure.

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Ultra Purification of Electrolytic Iron by Cold Crucible Induction Melting

and Induction Heating Floating Zone Melting in Ultra High Vacuum

Ultra Purification of Electrolytic Iron by Cold Crucible Induction Melting and Induction Heating Floating Zone Melting in Ultra High Vacuum

which were lower than each detection limit, was successfully obtained, even if this ingot contains their all elements of the detection limit value. Also the ultra-pure iron 35 g in weight of more than 99.9988 mass% purity was obtained from electrolytic iron of 99.996 mass% purity by the combination of cold-crucible induction melting in ultra-high vacuum and induction-heating floating-zone melting in UHV of 4 × 10 −7 Pa after the analysis of 35 elements. The concentration of C + N + O + S decreases from 14.4 mass ppm before zone-leveling to 2.4 mass ppm after four zone-leveling passes in ultra-high vacuum. For further ultra-purification of iron it is absolutely necessary to develop and establish the trace analysis techniques of measuring accurately the concentration of non-metallic impurity elements at levels below 0.1 mass ppm and metallic impurity elements at levels below 0.01 or 0.001 mass ppm.

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Preparation of Directionally Solidified B4C  TiB2  SiC Ternary Eutectic Composites by a Floating Zone Method and Their Properties

Preparation of Directionally Solidified B4C TiB2 SiC Ternary Eutectic Composites by a Floating Zone Method and Their Properties

SiC ternary composites generally included other end compo- nents and binary eutectic texture with ternary eutectic structure depending on composition and cooling rate. Since the cooling rate of directionally solidification by a floating zone method could be too fast to establish the thermody- namic equilibrium, phase boundaries or binary eutectic lines could not be demonstrated in the present study. However, the

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On the existence of solution of a two point boundary value problem in a cylindrical floating zone

On the existence of solution of a two point boundary value problem in a cylindrical floating zone

a liquid metal or semiconductor in a cylindrical floating zone of length 2L and radius R. In dimensionless coordinates (r ,y), points of the cylinder are given by −1 ≤ y = Y /L ≤ 1, 0 ≤ x = r /R ≤ 1, with free surface x = 1. The (y,r )-components of dimen- sionless velocity (u,v) are, respectively, u = 2A 3 (Re)f /x and v = −2A 3 (Re)f /x,

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k=0Magnetic Structure and Absence of Ferroelectricity in SmFeO3

k=0Magnetic Structure and Absence of Ferroelectricity in SmFeO3

4-mirror optical floating zone furnace. The high sample quality of this insulating reddish orange single crystal has been confirmed by EDX, Laue, and x-ray diffraction techniques as well as by magnetization and Mössbauer spectroscopy measurements; see the Supplemental Materials [6]. In the inset of Fig. 1(a) a polarization microscope image is shown that indicates — together with our Laue diffraction analysis — that our SmFeO 3 crystals are single domain single crystals. No impurity phases are visible in highly accurate synchrotron radiation powder x-ray diffraction measure- ments that have been performed at beamline B2 of DORIS-III at DESY. The lattice parameters, unit cell volume and relative expansion of the lattice parameters of SmFeO 3 (Pbnm setting with a < b < c) are shown in Figs. 1(a), 1(b). The b-lattice parameter exhibits a small anomalous kink around T N that is indicative for magnetoelastic cou-

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Virtex 4 Field Programmable Gate Array Based 32 bit FPM

Virtex 4 Field Programmable Gate Array Based 32 bit FPM

Many people consider floating-point arithmetic an esoteric subject. This is rather surprising because floating- point is ubiquitous in computer systems. Almost every language has a floating-point data type. Floating Point numbers represented in IEEE 754 format are used in most of the DSP Processors. Floating point arithmetic is useful in applications where a large dynamic range is required or in rapid prototyping applications where the required number range has not been thoroughly investigated. The floating Point Multiplier IP helps designers to perform floating point Multiplication on FPGA represented in IEEE 754 single precision floating point format. The single precision multiplier is divided into three main parts corresponding to the three parts of the single precision format [1]. The normalized floating point numbers have the form of

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Performance Evaluation of FPM on Spartan Family FPGAs and Analyze Its Effect on Bonded IOBs

Performance Evaluation of FPM on Spartan Family FPGAs and Analyze Its Effect on Bonded IOBs

floating point multiplier module have been explored because floating point multiplication is a most widely used operation in DSP/Math processors, robots, air traffic controller, digital computers. Because of its vast areas of application, the main emphasis is on the implementing it effectively such that it uses less combinational delay with high Speed. Floating point operations are hard to implement on FPGAs i.e. on reconfigurable hardware’s because of their complexity of their algorithms. On the other hand, many scientific problems require floating point arithmetic with high level of accuracy in their calculations. The parameter number of bonded IOBs (Input Output Blocks) has been analyzed while implementing the floating point multiplier on Spartan 2, Spartan 2E, Spartan 3 and Spartan 3E FPGA’s.

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FORMULATION AND EVAUTION OF FOATING TABETS OF METFORMIN HYDROCHORIDE

FORMULATION AND EVAUTION OF FOATING TABETS OF METFORMIN HYDROCHORIDE

evaluation for the all formulation is complies with the standard monograph. The post compression parameters like hardness, friability, thickness. The obtained data was best fitted for the floating tablet. The drug release data were explored for the type of release mechanism followed. The best fit with the highest determination r coefficients was shown by both the zero order and Higuchi models. Zero order release describes the release rate independent of drug concentration.

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Floating multiparticulate oral sustained release drug delivery system

Floating multiparticulate oral sustained release drug delivery system

Pharmaceutical invention and research are increasingly focusing on delivery systems which enhance desirable therapeutic objectives while minimizing side effects. Recent trends indicate that multiparticulate drug delivery systems are especially suitable for achieving sustained or delayed release oral formulations with low risk of dose dumping, flexibility of blending to attain different release patterns as well as reproducible and short gastric residence time. One of the approaches toward this goal is to develop the floating multiparticulates so as to increase the gastric retention time. Such systems have more advantages over the single-unit dosage forms. The development of floating multiparticulates involves different solvent evaporation techniques to create the hollow inner core. In this review, the current status of floating multiparticulate drug delivery systems including hollow microspheres (micro balloons), low density floating micro pellets and floating micro beads (acrylic resin based), microcapsules etc, their evaluation parameter, advantages, application, limitation and future potential for oral sustained release drug delivery are discussed.

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Non Linear Static Analysis of G+6 Storey Buildings With and Without Floating Columns by Provision of Infill Walls Using User Defined Hinges

Non Linear Static Analysis of G+6 Storey Buildings With and Without Floating Columns by Provision of Infill Walls Using User Defined Hinges

without floating columns are found to be 2.12 times safer than the models with floating columns. For brick infill models without floating columns, it is found to be 1.80 times safer than the models with floating columns. Similarly for concrete infill models without floating columns is found to be 2.12 times safer than the models with floating columns and by equivalent static pushover analysis. The bare frame, brick infill and concrete block models without floating columns are1.67, 1.64 and 1.97 times safer than the models with floating columns by response spectrum pushover analysis. From the above results it can be concluded that, the safety ratio for all the models are more than one, hence building models are over safe. The concrete infill models are safer compared to brick masonry infill models and bare frame models.

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FORMULATION OF REGIOSELECTIVE FLOATING MATRIX TABLETS OF DEXTRO METHORPHAN USING GAS FORMING TECHNIQUE AND EVALUATION

FORMULATION OF REGIOSELECTIVE FLOATING MATRIX TABLETS OF DEXTRO METHORPHAN USING GAS FORMING TECHNIQUE AND EVALUATION

ABSTRACT: The present study deals with the formulation and evaluation of gastroretentive floating tablets of dextromethorphan. Dextromethorphan is a highly potent and commonly used antitussive agent. It has no narcotic, analgesic or addictive properties and its potency as an antitussive agent is almost equal to that of codeine. The purpose of this research is to increase the gastric residence time by preparing gastroretentive floating tablets whereby making it available at its site of absorption and to achieve an extended action for a time period of 12 hrs. Dextromethorphan floating tablets were prepared by direct compression method using various grades of METHOCEL, POLYOX and CARBOPOL with three different concentrations. Preformulation studies were carried out and the compatibility of the drug with the excipients was confirmed through differential scanning calorimetry studies. The prepared gastroretentive floating tablets were evaluated for uniformity of weight, hardness, friability, density, drug content, floating lag time, floating time, swelling index and in vitro dissolution studies. The optimized formulations F3, F5 and F11 showed a floating time more than 12hrs with matrix integrity in pH 1.2. The in vitro release studies revealed that the drug release was sustained upto 12hrs. Optimized formulations showed no significant change in physical appearance, pre and post compression parameters and drug dissolution studies after storage at 40° C ± 2° C and 75% ± 5% relative humidity in a humidity chamber for 1 month. Using Higuchi’s Model and the Korsmeyer equation, the drug release mechanism from the floating sustained release tablets was found to be Anomalous (non-Fickian) diffusion.

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Discrete Fourier Transform Design Using Floating Point Numbers

Discrete Fourier Transform Design Using Floating Point Numbers

Floating point numbers are those numbers where there is a fixed number of digit before and after decimal point. For representing floating point number decimal point plays a major role. Depending upon the decimal point floating point bits are considered. The major disadvantages using with floating point number is it lacks accuracy and lowers the process speed. Fractional part representation is carried out using floating point number. Most of the languages are supported by the processors and large number of data computations is carried out. Hence for every computation to be carried out operating system should support the IEEE Standards.

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PREPARATION AND COMPARITIVE EVAULATION OF NIZATIDINE LOADED SUPER POROUS FLOATING HYDROGELS

PREPARATION AND COMPARITIVE EVAULATION OF NIZATIDINE LOADED SUPER POROUS FLOATING HYDROGELS

The floating tablets of Nizatidine were successfully formulated by effervescent technique. The floating tablets containing Chitosan, carbopol 934p and ethyl cellulose (F16) showed satisfactory results with respect to floating lag time, total floating duration, swelling ability and sustained drug release properties. The optimized formulation F16 followed zero order kinetic and the mechanism of drug release was found to be Higuchi mechanism.

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Seismic Analysis of Multi Storied Buildings with Floating Columns

Seismic Analysis of Multi Storied Buildings with Floating Columns

ABSTRACT: In Present scenario buildings either commercial or residential of higher occupancies need a wide amount of space for parking at ground floor levels, for the parking space needs the columns shouldn’t be spaced nearly. Avoiding of columns will impact severe effect on the performance of the Building. To avoid this type of Performance failure of structures, Floating columns are introduced in Buildings. The Floating columns are mainly laid and supported over the beams. In recent days, the floating columns are also using for structural appearance of buildings. To avoid the structural failure due to Floating Columns whenever there is a sudden impact of seismic waves occurs, it should be analyzed for seismic loads before its construction. In our design work, the floating columns are analyzed for seismic zone – II using ETABS Software and is compared with the building with and without floating column for Base Shear, Time Periods, Storey Displacements, Storey drifts of each floor, as per IS Codal Recommendations.

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Seismic Analysis of Multistorey Buildings with Vertical Irregularities having Floating Columns

Seismic Analysis of Multistorey Buildings with Vertical Irregularities having Floating Columns

The object of the present work is to compare the behaviour of multi-storey buildings with vertical irregularities having floating columns with and without shear walls under seismic forces. For this purpose a multi-storey building of 15 storeys is considered. To reduce lateral displacement and storey drift shear walls have been provided. Plan size of building is considered 20m x 20m. To study the behavior the response parameters selected are lateral displacement and storey drift. Building is assumed to be located in seismic zone III, zone IV and zone V. All the building models are analysed with and without shear wall. For this purpose 4 models of 15 storeys for zone III, zone IV and zone V are considered: Floating column without shear wall, Floating column with shear wall, Floating column with vertical irregularity without shear wall, Floating column with vertical irregularity with shear wall. In building having floating column area of 12m x 12m is taken in lower 4 storeys and 20m x 20m is taken in upper 11 storeys. For vertical irregularity building plan is reduced to 12m x 20m. From the results it is observed that in comparison to floating column building and floating column with vertical irregularity building, the model with vertical irregularity performs well in all the seismic zones. Also by providing shear wall drift and displacement values reduces as compared to without shear wall models for all the zones. In all the models storey drift and displacement values are less for lower zones and it goes on increases for higher zones because the magnitude of intensity will be the more for higher zones.

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A Detailed Study on Effective Floating Fibre Control in Ring Frame and its Impact on Yarn Quality

A Detailed Study on Effective Floating Fibre Control in Ring Frame and its Impact on Yarn Quality

As a basic principle, each of the two pairs of rollers in a drafting zone produces a zone of fibre friction by pressure. The fibre condensation caused by this pressure does not only have a vertical effect, but spreads from both sides into the fibre strand (shown in fig). The two fields of friction should not overlap, nor should their spheres of activity be too far apart.(Fig. 2)

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Seismic Analysis of Multistorey Buildings with Vertical Irregularities having Floating Columns

Seismic Analysis of Multistorey Buildings with Vertical Irregularities having Floating Columns

The object of the present work is to compare the behaviour of multi-storey buildings with vertical irregularities having floating columns with and without shear walls under seismic forces. For this purpose a multi-storey building of 15 storeys is considered. To reduce lateral displacement and storey drift shear walls have been provided. Plan size of building is considered 20m x 20m.

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Effect of Floating Column on The Behaviour of Composite Multistoried Building Subjected to Seismic Load

Effect of Floating Column on The Behaviour of Composite Multistoried Building Subjected to Seismic Load

building of G+3 situated at zone IV, using ETABS software linear static and response spectrum analysis is done and parameters such as displacement, storey drift and base shear is compared. A.P.Mundada and S.G. Sawdatkar[6]studied equivalent static analysis on existing building comprising of G+7. The load distribution on the floating columns and the various effects due to it is also been studied in the paper. The importance and effects due to line of action of force is also studied. In this paper they are dealing with comparative study of seismic analysis of multistoried building with and without floating columns. The equivalent static analysis is carried out for entire project mathematically 3D model using software STAAD Pro V8i and the comparison of these models and to get very systematic and economical design of structure.Shweta.A.Wagh and Dr.U.P.Waghe[7], have done comparative study of R.C.C. with Steel Concrete Composite (G+12, G+16, G+20, G+24) story buildings which situated in Nagpur earthquake zone II and wind speed 44m/s. Equivalent Static Method of Analysis is used. For modeling of Composite & R.C.C. structures, STAAD-Pro software is used and the results are compared. Comparative study includes deflection, axial force and shear force, bending moment in column and beam, cost. It is found that composite structure is more economical and speedy than R.C.C structure.Prof.Swapnil B. Cholekar and Basavalingappa.S.M[8] investigation is done on the mass irregularity of the building and its behavior in seismic regions, they have considered the Irregularity in the form of Mass in G+9 multistoried R.C.C. and Composite building and compared both R.C.C. and Composite structures. Equivalent static and Response spectrum methods are used to analyze the building as per IS 1893(Part 1):2002 using SAP 2000 software. Mass irregularity at upper or middle floor should be considered. The study shows that Composite structures having mass irregularity will better perform than R.C.C. structures.

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The Choice of Exchange Rate Regimes for EU Accession Countries

The Choice of Exchange Rate Regimes for EU Accession Countries

Before examining the question of what will be or should be the exchange rate policy of the candidate countries, current practices will be reviewed. Among the 10 EU candidate countries, there are three currency boards, Bulgaria and Estonia vis-à-vis the euro, and Lithuania vis-à-vis the dollar. Latvia applies a fixed exchange rate regime with an anchor to the SDR, Hungary, an inflation targeting system close to an exchange rate target with margins of 15%, and the other five authorise the directed exchange rate flotation. This type of plan covers a wide range of possibilities. As it stands, there is no indication that managed floating rates would be ‘ good management ’ . Among the six flexible exchange rates managed, the Czech Republic has an inflation target, excluding administered prices, the Slovak Republic, an inflation target (hard core of inflation), Poland (main inflation target) and the Slovenia, a growth rule for M3. The Central Bank of Romania is looking for price stability as the main objective, but without inflation targeting.

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