bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hydrogen in silicon and generation of haze on silicon surface in aging
Authors: Shiraiwa T , Inenaga S 
Published: December 2008

Hydrogen in silicon wafers was analysed by the gas analysis method of metals. Silicon wafers made by routine process contain a few ppm hydrogen. Diffusive hydrogen was observed in p-type silicon. It was proved that these hydrogen is absorbed into the wafer from water containing acid. The present results agree with current reports that hydrogen diffuses into p-type silicon and acts as a compensator of an acceptor.
Haze which is observed on mirror polished surface of p-type silicon was investigated by SEM and ESCA, and they revealed that haze is due to scattering of light by nodules of silicon oxide which grow on the wafer sarface in density of 104/cm2. The present anthors suggest that oxidation is due to water formed by hydrogen which diffused out to the surface of wafer as well as moisture in the atmosphere.
Identifying Gettered Impurities in Silicon by LIMA Analysis
Authors: Arst MC 
Published: December 2008

LIMA — Laser Induced Mass Analysis — was used to identify impurities captured in defect structures formed by three different backsurface damage systems. Analysis data indicate that a poly layer and wet sandblast damage provide greater getter efficiency than abrasive SVG backsurface damage.
In this study oxidized CZ and FZ silicon samples were evaluated. Impurities such as Na, K, Al, Cr, Cu as well as H, C, O and Cl could be identified in the backsurface structures and the oxide layer, but not in the silicon bulk beyond the getter related defects. The so identified gettered impurities were directly correlated to the defect density observed on the front surface, while also considering the impact of the interstitial oxygen concentration in the CZ wafer samples.
The LIMA technique uses a Nd:Yag laser to vaporize and ionize portions of the sample. The generated ions are then injected into a “time of flight” mass spectrometer, which displays a complete mass spectrum within microseconds. This capability to vaporize and characterize microvolumes of sample materials in relatively short times make this an attractive technique for bulk analysis.
Computerized Yield Modeling
Authors: Beck CH 
Published: December 2008

A computer program has been developed which extends the existing technique for calculating global circuit yield factor of lateral geometric design rules by process simulation. The current paper describes the inclusion of resistor limits as part of the general yield model. The program depends upon a reliable data base including: 1) geometric tolerances, 2) skews or offsets of critical dimensions during processing, 3) tolerable minimum separation of circuit element edges, 4) film tolerances of resistivity and thickness, and 5) resistor design limits.
The program incorporates conventional means of original design rule creation.
A Comparative Study of Carrier Concentration Profiling Techniques in Silicon: Spreading Resistance and Electrochemical CV
Authors: Pawlik M , Groves RD , Kubiak RA , Leong WY , Parker EHC 
Published: December 2008

The need to be able to measure carrier concentration profiles in silicon has led to the improvements in well known techniques e.g. spreading resistance (SR) and the development of new techniques e.g. electrochemical CV profiling (ECV). Both of these techniques have demonstrated features such as depth resolution, sensitivity and dynamic range but each show some limitations and problems in practical implementation. This paper demonstrates the use of both techniques on a number of samples, in particular silicon grown by MBE showing rapid dopant transitions. The profiles obtained by both techniques are compared and reasons for differences are discussed.
It is concluded that both techniques offer certain advantages in carrier concentration profiling e.g. dynamic range with SR and speed of data acquisition with ECV but both have limitations e.g. the need for correction factors with SR and limited dynamic range in ECV. As a consequence, both techniques should be viewed as being complementary and not competing.
Computer Techniques in Corrosion Protection
Authors: Průšek J 
Published: December 2008

The development of a problem oriented corrosion expert system (CES) is described. The CES has the following aims: (1) compilation of corrosion data files from data obtained by experimental activities or from analyses of practical results, (2) analysis of corrosion problems (determination of environmental aggressivity, degradation mechanisms, and corrosion kinetics) with the use of corrosion data bases and generalized theoretical knowledge, (3) optimizing the selection of technology for the protection of engineering plant, machines, and products from corrosion, and (4) economic analysis of the individual corrosion protections suggested.
Corrosion technologists and designers can utilize CIS to (1) file the results of corrosion research for subsequent application in corrosion analysis and evaluations and (2) objectivize, upgrade, and speed up the designing of corrosion protection including its economic evaluation.
The structure of the software has been devised for the interactive solution of problems. A dialogue of the user and the computer permits protection design optimizing.
Principles of Closed Systems for Handling of Agricultural Pesticides
Authors: Brazelton RW , Akesson NB 
Published: December 2008

Closed transfer of pesticide chemicals from the shipping container to a closed mixing tank and thence to the application machine is but one part of a long range program to protect and improve on the health and safety of workers who handle and apply pesticides. Admittedly the task of maximizing safety in the use of pesticides is far from accomplished, but no one can deny the necessity for moving as quickly and expeditiously as possible toward improvement in this troubled area of farm worker safety.
The use of closed systems has reduced the number of illnesses of mixer/loader personnel. Environmental contamination is also discussed.
Development of Devices Designed to Increase Safety During Field Handling of Pesticides
Authors: Anderson DL 
Published: December 2008

Since the 1940s substantial changes have occurred in the use of agricultural pesticides. A variety of new chemicals have been put into use, and the total volume of pesticides applied has increased. Concern for the safe handling of many of these chemicals has intensified as acute illnesses have resulted from handling exposure. Additionally, society's increasing concern with the latent effects of human exposure to chemicals is reinforcing argument for a “minimum exposure” approach to all pesticide handling and has heightened awareness of the logic of limiting environmental pesticide contamination.
This paper discusses the development of devices designed to increase safety during field handling of pesticides. A list of application crew potential pesticide exposure is given.
Charged Drop Application of Antisapstain Formulations to Lumber
Authors: Smith RS 
Published: December 2008

In this investigation, formulations of PP523 and TCMTB were sprayed on softwood lumber using a specially-constructed “Electrodyn” sprayer developed by Imperial Chemical Industries PLC. The lumber surfaces were evaluated subsequently for overgrowth by fungi after a four-month period of incubation. Formulation PP523 provided adequate protection of hem-fir lumber while TCMTB gave suitable protection to the SPF lumber. Drop size and spray distribution patterns on the wood, were affected by Electrodyn nozzle voltage, fluid flow rates, height of the nozzle above the lumber surface and speed of lumber passing the nozzle. The wrap-around effect, caused by the charged drops, gave reasonable coverage by the chemical on the sides and lower surfaces of the lumber.
The efficiency of chemical application could be at least doubled when compared with conventional hydraulic sprays. Volumes of solution used to obtain adequate control of mould and stain on lumber were several magnitudes less than with hydraulic sprays while surface concentrations of chemical required to achieve protection were possibly lower. This technology could significantly advance the current procedures used in sawmills throughout Canada, by providing a more efficient and much safer method for applying antisapstain chemicals on lumber.
Aerial Application of a Granular Herbicide
Authors: Cochran RJ , Boring LE 
Published: December 2008

The aerial application of liquid pesticides has been used for many years as an effective, economical means of applying chemicals to large acreages. Aerial application of solid formulations has had only limited usage and has been mainly applied from fixed wing aircraft.
A granular herbicide formulation has been developed for herbaceous and brush control in conifer forest management. Aerial application provides an economical method to spread herbicides evenly across timberlands which can be very rough and have existing trees. Because timberlands are usually far from air fields used by fixed wing aircraft, helicopters are used flying out of locally cleared helipads. Since there was no commercially available equipment existing, application equipment was modified and application procedures developed to accurately apply the granules from helicopters. Refinements in the formulation and equipment have allowed application rates of 1000 acres per day.
Effect of Chemistry on Elevated Temperature Nodular Corrosion
Authors: Weidinger HG , Garzarolli F , Eucken CM , Baroch EF 
Published: December 2008

Short-term autoclave tests are currently being used by some as a selector for nodular corrosion, a phenomenon which is observed in boiling water reactors. The effects of composition have been evaluated previously with respect to mechanical properties. The present study extends this earlier work on chemical effects to include corrosion performance in 500°C steam, one of the predictor tests. Fifty-three ingots having compositions within as well as outside the specification range for the Zircaloys were melted and fabricated into plate and strip using a conventional fabrication procedure that incorporated an intermediate beta quench followed by working and annealing in the upper alpha region.
The roles of various elements, singly and in combination, on 500°C corrosion were examined systematically. The alloy elements covered the following ranges: tin, 0.02 to 5.14 wt%; iron, 0.04 to 0.57 wt%; chromium, 0.04 to 2.76 wt%; and nickel, 0.003 to 0.046 wt%. In addition, carbon, silicon, aluminum, and phosphorus were evaluated over the range of standard Zircaloys.
The frequency and severity of nodule formation were generally related to the weight gain for both static and refreshed autoclave tests. The transition elements chromium, iron, and nickel exhibited the most pronounced effects, with the effect of nickel being dominant. High weight gains are generally observed at low concentrations of iron, chromium, and nickel, and low weight gains are observed at high concentrations of these elements. The composition of Zircaloy is in the transition region between the two extremes. Equations were developed describing this relationship.
Heat treatments that affect the distribution of the intermetallics have a significant effect on the corrosion properties of Zircaloy. Process temperatures in the high alpha-range generally lead to high weight gains for Zircaloy. For beta quenching the results depend on the specific conditions of the quench and of the test performed. Testing in static steam resulted in low weight gains for all beta treatments studied, while testing in refreshed steam led to different results depending on quenching rate. In the refreshing autoclave tests high weight gains are observed at low quenching rates from the beta.
The best results are obtained by beta quenching at a minimum rate of above 5 K/s. For materials processed in this manner low weight gains persist even after long time annealing in the high alpha-range and sensitivity to nodular corrosion develops in Zircaloy only at temperatures close to the alpha/beta-transition.
Zircaloy Fuel Cladding Behavior in a Loss-of-Coolant Accident: A Review
Authors: Erbacher FJ , Leistikow S 
Published: December 2008

This paper reviews the state-of-the-art experimental work performed in several countries with respect to the acceptance criteria established for the emergency core cooling (ECC) in a loss-of-coolant accident (LOCA) of light water reactors (LWRs). It covers in detail oxidation, embrittlement, plastic deformation, and coolability of deformed rod bundles.
The main test results are discussed on the basis of research work performed at the Karlsruhe Nuclear Research Center (KfK) within the framework of the Nuclear Safety Project (PNS). Reference is made to test data obtained in other countries.
The paper concludes that the major mechanisms and consequences of oxidation, deformation, and emergency core cooling are sufficiently investigated in order to provide a reliable data base for safety assessments and licensing of LWRs. All test data prove that the ECC criteria are conservative and that the coolability of a LWR and the public safety in a LOCA can be maintained.
Residual Stresses in Textured Zirconium Alloys
Authors: MacEwen SR , Tomé C 
Published: December 2008

The elastic, plastic, and thermal properties of zirconium-base alloys are highly anisotropic. Consequently, thermomechanical treatments will leave fabricated components with high residual stresses. These stresses play an important role in determining subsequent mechanical properties and the dimensional stability of reactor-core components. When a component is deformed or subjected to a change in temperature, the total strain in any given grain will be accommodated elastically, plastically by shear on the active slip systems or by twinning, and by thermal expansion. The partitioning among the three modes depends not only on the particular orientation of the grain but also on the orientation of the other grains (texture) in the component. A self-consistent analysis, based on the concept of the hcp single-crystal yield surface, has been developed to predict the way that grains in a textured polycrystal respond to arbitrary external thermal or mechanical loading. The calculation follows the elastic-plastic evolution of strain inside each grain, taking into account the anisotropic elastic constants and thermal expansion coefficients. Workhardening due to shear on the active slip systems is included explicitly in the analysis.
Specific examples of the residual stresses produced by tension-compression deformation and thermal cycling of Zircaloy-2 rod will be described. It will be shown that the elastic-plastic transition in Zircaloy-2 requires much larger uniaxial strain and results in much higher apparent workhardening rates than in fcc metals. The predictions will be compared with experimental measurements of residual stresses made using the technique of neutron diffraction.
Zirconium-Barrier Cladding Attributes
Authors: Rosenbaum HS , Rand RA , Tucker RP , Cheng B , Adamson RB , Davies JH , Armijo JS , Wisner SB 
Published: December 2008

This metallurgical study of Zr-barrier fuel cladding evaluates the importance of three salient attributes: (1) metallurgical bond between the zirconium liner and the Zircaloy substrate, (2) liner thickness (roughly 10% of the total cladding wall), and (3) softness (purity). The effect that each of these attributes has on the pellet-cladding interaction (PCI) resistance of the Zr-barrier fuel was studied by a combination of analytical model calculations and laboratory experiments using an expanding mandrel technique. Each of the attributes is shown to contribute to PCI resistance.
The effect of the zirconium liner on fuel behavior during off-normal events in which steam comes in contact with the zirconium surface was studied experimentally. Simulations of loss-of-coolant accident (LOCA) showed that the behavior of Zr-barrier cladding is virtually indistinguishable from that of conventional Zircaloy cladding. If steam contacts the zirconium liner surface through a cladding perforation and the fuel rod is operated under normal power conditions, the zirconium liner is oxidized more rapidly than is Zircaloy, but the oxidation rate returns to the rate of Zircaloy oxidation when the oxide phase reaches the zirconium-Zircaloy metallurgical bond.
Iodine-Induced Stress Corrosion of Zircaloy Fuel Cladding: Initiation and Growth
Authors: Brunisholz L , Lemaignan C 
Published: December 2008

Because of its impact on nuclear power plant reliability, fuel cladding failure induced by pellet cladding interaction is a problem of major concern. It is usually analyzed as stress corrosion cracking caused by volatile fission products like iodine.
In order to analyze the mechanisms of iodine stress corrosion in Zircaloy-4 cladding tubes, a series of tests have been carried out on recrystallized and stress-relieved cladding from different origins. The tubes were pressurized in the presence of iodine (1.5 mg cm−2 Zry) at 350°C, and the time to failure was measured versus applied hoop stresses.
In order to be able to analyze independently initiation and growth, a special procedure has been developed to induce a small fatigue crack (⋍200 µm) in the inner wall of some specimens before the pressurization test. After failure of the specimen, the initial fatigue crack and the subsequent stress corrosion crack are clearly separated. Using linear elastic fracture mechanics analysis, those measurements allowed us to determine the stress corrosion average crack growth rates and the threshold stress intensity factor for crack growth KIscc.
The effect of loading path has been analyzed during slow tensile tests (5 µm s−1) performed under iodine vapor at 350°C along the axial and circumferential orientations. Differences in time to fracture and loss of ductility for the two orientations can be explained in terms of crack growth along preferred crystallographic planes or grain boundaries that were confirmed by SEM fracture surface observation.
Chemical Inhomogeneity Populations in Various Zircaloy Claddings and Their Association with SCC and Corrosion Resistance
Authors: Tasooji A , Miller AK , Cheung TY , Brooks M , Santucci J 
Published: December 2008

A technique has been developed that permits detection and characterization of sparsely distributed chemical inhomogeneities in Zircaloy. These inhomogeneities have previously been observed at the origins of iodine stress-corrosion cracks but are not detectable by, for example, simple scanning electron microscopy (SEM) examination. The technique uses radioactive iodine to “label” the chemical inhomogeneities, autoradiography to detect their locations, and SEM and energy-dispersive X-ray analysis (EDAX) to further characterize them. Large areas of surface have been surveyed and statistically meaningful populations of chemical inhomogeneities measured for five different lots of Zircaloy cladding. Inner surfaces and cladding cross-sectional surfaces have been studied. There are clear differences in chemical inhomogeneity size distribution and composition between the various claddings.
For three of the claddings characterized in this work, the previously measured stress-corrosion cracking (SCC) threshold stresses correlate well (inversely) with the new data on their average chemical inhomogeneity sizes. Of special interest is the fact that the most SCC-resistant cladding contains far fewer iron-bearing inhomogeneities than the other claddings.
To investigate whether chemical inhomogeneities relate to the aqueous corrosion performance of the material, a blind test was conducted on 14 samples representative of material previously tested in an autoclave at 500°C at 10 342 kPa (1500 psi) for 24 h. The unautoclaved companion samples were examined by autoradiography. The results show that, in general, materials with good corrosion performance in the high-temperature autoclave tests are also characterized by a low population of chemical inhomogeneities and vice versa.
Selected chemical inhomogeneities were cross-sectioned and studied further using the electron microprobe. These measurements confirm the existence of a silicon- and aluminum-rich region extending about 10 µm below the surface, and also indicate iron-rich locations which coincide with silicon-rich locations and have spacings on the order of the grain size. The distribution of aluminum is relatively flat.
The implication of these observations in terms of possible origins of the chemical inhomogeneities is discussed briefly.
Determination of Metal Sparking Characteristics and the Effects on Explosive Dust Clouds
Authors: Dahn CJ , Reyes BN 
Published: December 2008

Of major concern in industry are hazards posed by metal-to-metal sparking in environments where potentially explosive dusts are present. The probability of ignition of a dust cloud by metal sparking is dependent on many factors including the type of metal, the contact speed of the metal surfaces, the contact time of the metal surfaces, the pressure on the contact surface, and the type and concentration of the dust cloud present (per Bowden, F. P. and Thomas, P. H., “The Surface Temperature of Slidings Solids,” Proceedings of the Royal Society of London, Series A, Vol. 223, May 1954, pp. 29–40).
The purpose of the test program was to determine the sparking characteristics of a series of metals and the effects of the sparks produced on several types of hazardous dust clouds. Propellant and black powder dust layers and clouds would be considered as hazardous materials. The test program showed metal sparking could ignite hazardous materials in dust cloud form.
Testing of Electrical Equipment for Use in Class II Hazardous Locations
Authors: Vaickauski RC 
Published: December 2008

To prevent dust explosions, electrical equipment in Class II hazardous locations must have special construction features that meet rigid performance criteria. Dust-ignition-proof, dust-tight, and intrinsically safe are types of constructions used.
Underwriters Laboratories (UL) has developed construction and performance standards for these types of equipment. UL's hazardous location equipment test lab is a specially designed facility that provides separation of dust and explosion testing areas from laboratory personnel working areas. The lab has two dust test chambers for conducting dust penetration and dust blanket temperature tests. After each test setup is completed, testing is controlled remotely to protect lab personnel in case of a dust explosion. Testing is conducted using either grain or magnesium dust. Intrinsically safe equipment undergoes spark ignition tests with a specially constructed switching mechanism.
This paper describes Class II hazardous locations, types of protection used for equipment, and how electrical equipment tests are performed.