bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of Section Size on Transition Temperature Behavior of Structural Steels
Authors: Landes JD , McCabe DE 
Published: December 2008

The transition temperature behavior of structural steels was evaluated using fracture mechanics specimens and elastic-plastic evaluation techniques. In the transition temperature region, the ductile tear and JR-curve behavior of structural steels was relatively independent of test temperature and specimen geometry effects. Consistent JR-curve development was interrupted by Jc instability events, however, and it is this property that showed high sensitivity to test temperature and constraint variations. The temperature at which the Jc instability toughness rises rapidly was dominated by specimen thickness but within this behavior was a subtle interaction with constraint variations due to ligament length variations.
Specimens of fixed proportionalities can be used with Weibull analysis and extremal statistics methodology to demonstrate why the transition temperature behavior of steels is specimen size dependent. A distribution of Jc cleavage instabilities on small specimens can be used to predict Jc instability distributions on larger specimens.
The Purity Determination of Three Compendial Steroids by Differential Scanning Calorimetry
Authors: Lim OB , Oliver EA 
Published: December 2008

The use of a differential scanning calorimetry (DSC) with a data reduction system and a commercially available purity program is presented as an alternate method for the determination of the purity of the steroids Norethindrone, Mestranol, and Ethinyl Estradiol currently listed in the United States Pharmacopeia (USP). This method's ability to determine the purity of a material without recourse to the use of a pure reference standard of the same substance has been seen as one of the major advantages of differential scanning calorimetry (DSC).
An evaluation of the applicability of the DSC methodology was carried out using prepared steroid mixtures. Compositions of 1 and 4% of foreign related steroids with each chosen steroid were used to establish predetermined purity levels for subsequent analysis. As the primary objective of this work was to establish an alternate method for the purity evaluation of pharmaceutical grade raw materials, comparison with the current USP and equivalent methodology was carried out. Thus, results also were obtained for both ultraviolet spectrophotometric (USP) and gas chromatographic methods. Good correlation was obtained between the three methods. However, the DSC method proved to have superior characteristics in terms of precision and accuracy and hence offers an attractive and reliable alternative for the determination of the purity of these materials.
Production and Development of Neutron Transmutation Doped Silicon
Authors: Herzer H 
Published: December 2008

Considering the production of NTD-silicon our interest is focussing on market growth, application fields and questions like reactor capacity, costs and material quality. Market growth still is in a further steady increase and since IC application particularly CMOS devices are not expected to turn over to NTD-silicon there is plenty of reactor capacity available to follow the market increase in power device application.
Further development of NTD-silicon is discussed regarding maximum diameter, upper resistivity limit and quality aspects.
Metal Ion Sensors Based on Immobilized Fluorogenic Ligands
Authors: Seitz WR , Saari LA , Zhujun Z , Pokornicki S , Hudson RD , Sieber SC , Ditzler MA 
Published: December 2008

A metal ion sensor may be prepared by immobilizing a fluorogenic ligand on the common end of a bifurcated fiber optic. Fluorescence is excited through one arm of the fiber optic and observed through the other. When the immobilized ligand is placed in a solution of metal ion, some of the metal associates with the ligand causing its fluorescence characteristics to change. Equations are derived for the response of a sensor for systems where a 1:1 complex is formed.
We have successfully immobilized several ligands including morin, quercetin, and calcein to cellulose using cyanuric chloride as a coupling reagent. Immobilized morin is only very weakly fluorescent but forms fluorescent complexes with Al+3 and Be+2 and can be used to sense these ions. Immobilized calcein is fluorescent by itself but is quenched by several metal ions. We have also immobilized hydroxy napthol blue and 8-hydroxyquinoline-5-sulfonate on anion exchangers. In addition 2, 2′, 4-trihydroxy-azobenzene and p-tosyl-8-aminoquinoline have been immobilized to silica gel.
An Experimental and Theoretical Approach to Rock Deformation at Elevated Temperature and Pressure
Authors: Brodsky NS , Getting IC , Spetzler H 
Published: December 2008

Specimens of Westerly granite have been tested to failure in triaxial compression during investigations of strain rate and temperature-dependent deformation within the brittle regime. We have used a method of specimen pretreatment that enables more accurate measurement of temperature dependent deformation caused by thermally activated crack growth under applied load. Thermal cycling of Westerly granite before testing to failure modifies the form of the stress-strain curve obtained.
In modelling our experimental results we find stress corrosion and a fracture mechanics approach for evaluating crack-tip stresses adequate to explain time-dependent phenomena. To reasonably predict temperature and confining pressure dependent deformation, we must include additional constraints such as frictional characteristics or perhaps plastic deformation mechanisms.
Measurement of Thermal Conductivity and Thermal Expansion at Elevated Temperatures and Pressures
Authors: Van Buskirk R , Enniss D , Schatz J 
Published: December 2008

Laboratory procedures and equipment have been developed to measure thermal response of rock under a simulated in situ environment of overburden stress, pore fluid pressure, and temperature. Routine tests are conducted up to 250°C, with stress levels to 100 MPa, on basalt, shale, tuff, and sandstone. High-pressure high-temperature use of the transient “needle-probe” heat source technique for the measurement of thermal conductivity is discussed. Considerations in the design of the thermal expansion apparatus, which maximize stability and minimize error, are included.
Laboratory procedures used, calibration techniques, and overall accuracy of the testing are reviewed. Thermal conductivity and thermal expansion are measured on equipment calibrated by using fused quartz as a standard. Uncertainty of calibrations caused by some inconsistency in published values for fused quartz is discussed. Methodical specimen preparation, frequent calibrations and computer test control, and data reduction allow accuracy to be maximized and relatively long-term tests to be conducted with a high degree of repeatability.
Where possible, results of the tests are compared with previously published values. A suite of data obtained in support of studies on a potential nuclear waste repository in tuff is examined. Comparisons of theoretical thermal conductivities and expansions, derived from the behavior of the mineral constituents of the rock, and the measured responses are made.
The advantages of these systems lie in the relative ease by which specimens may be tested at elevated temperatures and pressures, and the repeatability of the results. The accuracies (which are dependent upon calibration accuracies) are well within the range of engineering investigations.
A Small-Scale System to Evaluate Anti-Foam Performance
Authors: Frank R , Hazen JL 
Published: December 2008

Foaming is a widely observed phenomenon in manufacturing and product-filling and in dilution of agricultural chemicals. Foam generation should be avoided, however, since time and container volume are limited. Antifoam agents are designed to minimize foam-related trouble when used in the formulation as a processing aid or a spray-tank defoamer. This paper describes the design of simple equipment which allows easy laboratory-scale evaluation of defoamers for liquid systems.
The principle is as follows: A calculated amount of water at given pressure is added to a certain volume of formulation through a specially designed nozzle. After generation of foam, its initial volume and decomposition rate are measured versus time. This system allows very simple testing of the influence of defoamers on liquid systems. It requires only a very small amount of material and it quickly yields accurate results relating to real-life conditions.
Evaluation of Plant Growth Regulators
Authors: Armstrong TF 
Published: December 2008

In recent years, interest in plant growth retardants (PGRs) for use on turfgrass has been very high. This interest has occurred because of the availability of some new experimental compounds, increases in fuel and labor rates, and the desire for people to have more recreation time. In the past, turfgrass PGRs were primarily foliage-absorbed compounds; however, the identification of root or crown absorbed experimental compounds (such as MON-4620) has created a renewed interest in the evaluation and potential use of a PGR on turfgrass.
This paper presents an overview of Monsanto's development efforts to identify and implement turfgrass PGR evaluation parameters, and it discusses the need to standardize these evaluation parameters with both chemical industry and university researchers.
An Inexpensive, Multiple-Experiment Monitoring, Recording, and Control System
Authors: Meyn DA , Moore PG , Bayles RA , Denney PE 
Published: December 2008

Strip chart recorders and data loggers have numerous shortcomings for monitoring sustained-load cracking (SLC) and fatigue tests, principally because they record at fixed rates. During a long test this affords low resolution during rapidly changing events and creates large amounts of mostly useless data. For over two years the authors have used a personal computer to monitor tests and record data for SLC and fatigue experiments. The computer stores specimen identification and test parameters, converts raw data into usable form, displays current test status, notes and acts on various test status parameters, periodically stores significant data on a floppy disk system, and automatically terminates tests as specified by the operator. The decision-making capability of the computer greatly reduces the amount of nonsignificant data to be stored while permitting more rapid data acquisition when the signals begin to change rapidly. A fast-switching battery-inverter system provides standby power for up to two and a half days in the event of power failure. If both primary and standby power fail, the computer's autostart feature allows it to resume data collection when power resumes.
The use of BASIC permits software to be produced in-house and allows revision as operational needs change. The input routines, start-up, and running of experiments are completely interactive, and designed to prevent omissions and errors by the operator. Presently four experiments can be conducted simultaneously, but a newly acquired 16-channel, 12-bit analog-to-digital converter will allow for considerable expansion. Because system response is inadequate to measure and record fatigue load signals directly, they are filtered to produce an average value which is recorded. The analysis of data stored on disk files is done using another personal computer to avoid interference with data acquisition. A unique feature of the analytical method is the use of the decrease in load with increasing crack length in the stiff, displacement-controlled test configuration to calculate crack lengths, instead of using a clip gage across the notch.
Krak-Gages for Automated Fatigue Crack Growth Rate Testing: A Review
Authors: Liaw PK , Logsdon WA , Roth LD , Hartmann H-R 
Published: December 2008

Bondable Krak-gages were utilized to monitor fatigue crack growth rates (FCGR) of various steels in air and salt water at 24°C and in wet hydrogen at 80°C. The FCGR data generated via bondable Krak-gages were consistent with those generated via either the compliance technique or optical measurements. Moreover, Krak-gages were effective in monitoring short crack extension.
Using atomic fusion technology, Krak-gages were sputtered on specimens so as to perform high-temperature (288 and 427°C) FCGR experiments. The FCGR results obtained with the sputtered Krak-gages were in good agreement with those obtained by the compliance method.
The Krak-gages were found to be a valuable addition to fracture mechanics testing. They readily interface with computers for fully automated FCGR experiments.
Evaluation of Thermal Conductance of Liquefied Natural Gas Tank Insulation
Authors: Brendeng E 
Published: December 2008

The activities in testing of liquefied natural gas (LNG) insulation of The Division of Refrigeration Engineering at the University in Trondheim were initiated by the need for a satisfactory insulation system for the spherical tank LNG carriers of Moss Rosenberg Verft. A large scale guarded hot plate apparatus has been built, with test area 2 by 3 m2. The temperature on the cold plate may be 0 to –162°C, and on the warm plate 30 to –30°C. Measurements may be made in horizontal convection-free mode, and in vertical convection mode.
A load-bearing evacuated insulation may be a possible solution in the efforts to reduce the boil-off of the tank content. A heat flow meter apparatus for testing evacuated insulations under load has been built, with diameter of the specimen 400 mm, and thickness up to 100 mm.
Recent Developments with the Thin-Heater Thermal Conductivity Apparatus
Authors: Hager NE 
Published: December 2008

A thin-foil heating element is employed in a thermal conductivity apparatus that operates in accordance with the basic concept of the guarded hot plate. The metal foil is sufficiently thin that lateral heat flow along the plane of the heater is insignificant, at least in the central region, so there is no need for isolation and separate temperature control of a guard region. This makes the apparatus simple and inexpensive to construct and operate. The resultant low-mass configuration minimizes drift error and usually reaches steady state in less than 30 min with 0.5-cm-thick specimens of nonmetallic solids. Thermal conductivity values are calculated on an absolute basis with an estimated accuracy of ±3%.
Speed and simplicity make the apparatus well suited for product-development and quality-control applications. Because temperature differences within the sample do not exceed a few degrees, uncertainty in mean sample temperature is sharply limited, water-vapor-migration problems are minimized, and thermal conductivity can be measured close to melting points or other critical temperatures. New data obtained with dry calcium silicate give preliminary experimental verification of the validity of the apparatus in the temperature range extending between ambient and 550 K.
Research in Calibration and Application Errors of Heat Flux Sensors
Authors: van der Graaf F 
Published: December 2008

The influence of the presence of a built-in heat flux sensor on local heat flux has been studied.
Starting with the definition of a calibration value for the heat flux sensor (the intrinsic calibration value), this influence is described and expressed in measurement errors. The influence is considered to result from two separate and well-recognized effects, namely, the change in thermal resistance and the heat flux deflection. This splitting up has been proved correct by both experiments and calculations. A satisfying agreement between the methods was found.
The importance of a well-dimensioned guard ring, dependent on parameters such as thermal conductivity and dimension, is apparent. Finally, rough guidelines for the design of “low-error” heat flux sensors and a basic calibration method are given.
A New Type of Heat Flowmeter for Application and Study of Insulation and Systems
Authors: Degenne M , Klarsfeld S 
Published: December 2008

Greater and greater use is being made of the heat flowmeter for laboratory and in situ measurements of materials and systems. Two new types of flowmeters are described: (1) with junctions arranged in two parallel planes and (2) with coplanar junctions.
Through metallization and photoetching, as employed in printed circuits, it is possible to achieve relatively slim and sensitive “intergrating” heat flowmeters that offer a large surface area and excellent uniformity.
Stress and Load Dependence of Microindentation Hardness
Authors: Vitovec FH 
Published: December 2008

The effect of the test load on the sensitivity to stress of the diamond pyramid hardness (DPH) was investigated on a martensitic spring steel, a Type 304 stainless steel, and an aluminum bronze with duplex microstructure. For this purpose, a loading frame and load cell of 1200-N capacity were fitted to the microhardness tester, which provided for application of uniaxial tensile loads to a flat test specimen. The test materials were heat treated differently and had different surface preparations, ranging from polished before vacuum annealing to electropolished following the annealing treatment.
Within the load range of 15 to 500 gf, the hardness increased in most cases to a peak from which it leveled off to a more or less constant value as the test load increased. Applied uniaxial tensile stresses did not change this trend except when plasticity initiated. In general, the hardness decreased linearly with increasing applied tensile stress. The rate of decrease was independent of the load for the hardness measurement. Yielding affected the hardness sensitively, particularly at small loads, thus changing the trend of the effect of applied stress on hardness as well as the hardness-load relation. Surface films or residual stresses do substantially affect the hardness-load relationship and the trend of the stress effect.
Review of Scratch Test Studies of Abrasion Mechanisms
Authors: Kosel TH 
Published: December 2008

The use of scratch tests to simulate the material removal mechanisms which occur during abrasion is reviewed. Although useful studies of the effect of the rake angle on material removal have been carried out using diamond tools, closer simulation of the mechanisms of material removal can be obtained using actual irregular individual abrasive particles as scratch tools.
Previous studies are reviewed in which scratch tests have been performed with both conventional scratch test instruments and a specially designed system used for in situ scratch tests in the scanning electron microscope (SEM). Multiple-pass scratch tests over the same scratch path have been shown to create surface features and wear debris particles which are very similar to those produced by low-stress abrasion. Alumina (Al2O3) particles have been shown to produce continuous micromachining chips from the hard, brittle carbide phase of Stellite alloys, establishing direct cutting as the important mechanism of material removal for this type of abrasive. An in situ study of material removal from white cast irons by quartz particles has provided conclusive evidence that carbide removal does not occur by direct cutting but rather always involves microfracture.
Previously unpublished work which has compared scratch tests with crushed quartz and alumina particles is included. Also described is a new scratch test system which controls the depth of cut rather than the scratch load in order to simulate high-stress abrasion, in which abrasive particles are constrained to a fixed depth of cut. Preliminary new results show substantially different carbide fracture behavior under fixed-depth conditions.
Quality Assurance of Flexible Plastic Pipes for Hot-Water Service
Authors: Skarelius J 
Published: December 2008

A common way to express the durability of a plastic material is to present a long-term strength diagram for different temperatures for well made straight pipes. In the case of materials for hot-water pipes, the testing time must be longer, and the tests must also be completed with bent and notched pipes, and tests in water completed with additives reducing the surface tension. Examples and test methods are given in the paper. Comparisons between testing with water or air outside the pipes at high temperatures are also made.
A way to measure the thermostability and lifetime of a material or product is to use induction time in differential thermal analysis (DTA) or differential scanning calorimetry (DSC). This method must be used with greatest care and only together with other long-term tests. The use of Arrhenius plots at high temperatures to predict lifetimes of pipes is not helpful. Examples are given in the paper.
DTA or DSC induction tests are however very useful in production control and in, for example, testing of antioxidants resistance to extraction into water. When the type tests mentioned above have secured the possibility of a long service life of the material, the quality control methods (short-term production control tests) shall ensure that production quality is the same as the type tested quality. The correspondence between long- and short-term tests must then be proven. The paper will also deal with these questions.
Ultrastructural Examination of In Vitro and In Vivo Cells Exposed to Elements from Type 316L Stainless Steel
Authors: Lucas LC , Bearden LJ , Lemons JE 
Published: December 2008

The ultrastructural features of in vivo and in vitro cells exposed to Type 316L stainless steel corrosion product solutions were examined. The in vivo cells were from fibrous tissue capsules formed around stainless steel rods implanted in the back muscles of New Zealand white rabbits. Aqueous solutions of the stainless steel alloy were injected at the implant-to-capsule interface to increase the concentration of alloy constituents bathing the tissues. The in vitro cells were cultured human gingival fibroblasts also exposed to stainless steel solutions of similar concentration. The ultrastructural features of both in vitro and in vivo cells were examined by transmission electron microscopy.
The following observations were made for both the in vitro and in vivo cells:
1. The severity of the cellular response increased when the concentration of the solutions of stainless steel exposed to the cells increased.
2. As the severity of the cellular response increased, the cells showed a decrease in rough endoplasmic reticulum, an increase in cytoplasmic vacuolation with altered organelles, a more diffuse plasma membrane, and a decrease in cellular organization.