bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cryoscopic Determination of the Purity of Benzene by Calorimetry
Authors: Furukawa GT , Piccirelli JH , Reilly ML 
Published: December 2008

To test the cryoscopic method for determination of purity, the impurity concentrations of duplicate specimens taken from four prepared lots of benzene were determined on the basis of the van't Hoff law of freezing-point lowering and on the assumption that the phases in equilibrium were composed of pure solid benzene and of liquid benzene containing all of the impurities in ideal solution. The adiabatic calorimeter method was used in conjunction with automatic temperature controls and platinum resistance thermometry. Three of the four lots contained weighted amounts of pure n-heptane as an impurity, known only to the preparer, which were added to portions of the first lot which had been purified to better than 99.999 mol % by a fractional crystallization technique.
The mean impurity concentration determined by the calorimetric method for duplicate specimens from the lot of purified benzene was found to be 0.000660 mol % with deviations of ±27% from the mean of the two specimens. The results of the duplicate specimens from each of the three lots containing added impurity did not deviate by more than ±2% from their means which were 0.0883, 0.206, and 1.09 mol % impurity. These mean values deviated by −4, +2, and −7%, respectively, from the values calculated from the known amount of n-heptane impurity that was added to each lot. These results demonstrate that the cryoscopic determination of purity by calorimetry yields accurate values.
Hot-Wire Technique for Droplet Measurements
Authors: Mahler DS , Magnus DE 
Published: December 2008

An instrument using hot-wire technology to measure droplet size distributions in the 1 to 450 µm size range is discussed. Such instrumentation has several advantages over present techniques which are dominated by a variety of laser light scattering approaches. The major advantages are: (1) the hot-wire instrument is readily portable; (2) no careful alignment is necessary; and (3) the instrument is available at a fraction of the cost of optical instruments.
The present paper discusses some details of the droplet/wire interaction, for example, effects of the wire mounting posts, “grazing” interactions, aerodynamic effects, and liquid variation. Also discussed are the means of raw data corrections to obtain a variety of mean droplet sizes, volume concentration, and volume flow rates.
Limitations will be discussed along with examples of where the instrument can best be utilized.
Industrial Applications of Corrosion-Resistant Tantalum, Niobium, and Their Alloys
Authors: Burns RH , Shuker FS , Manning PE 
Published: December 2008

During the period 1960–1982, tantalum, niobium, and their alloys have become increasingly important in industrial applications where superior corrosion resistance is required. These materials are particularly attractive when selected on the basis of “life cycle costing”. This takes into account initial cost, levels of product quality, length of trouble-free operation, and any increase in productivity due to reduced downtime and lower maintenance requirements. The chemical process industry, in particular, has taken advantage of these materials for processing mineral acids at temperatures and concentrations higher than can be withstood by any other materials.
Advances in electron-beam melting technology have also made it possible to manufacture larger and cleaner ingots, resulting in the availability to industry of larger sheets, tubes, and plates with improved property reliability.
Evaluation of Gettering Efficiency of Backside Damage by the Use of the “Haze” Test
Authors: Domenici M , Ferrero G , Malinverni P 
Published: December 2008

“Haze” test has been used to evaluate gettering efficiency on the wafers damaged by different techniques.
The wafers have been partially back side damaged and then intention ally contaminated by “pure” contaminants, such as the most common 3d transition and noble metals.
In the particular case of contamination by iron we are calibrating our qualitative results by parallel measurements using neutron activation analysis: this is done utilizing thermal as well as epithermal and fast neutrons to transmute Fe-54 into *Mn-54.
Optimization Criteria for the Stabilization of Sewage Sludge and Biogas Production Through Anaerobic Digestion: An Example of an Environmental Biotechnology Application
Authors: Ferraiolo G , del Borghi M , Solisio C , Gardi G 
Published: December 2008

According to environmental protection and energy conservation principles, anaerobic digestion of activated sludges should have two main purposes: to stabilize the sludge within allowable limits and to increase biogas production as much as possible, in order to meet ecological requirement without neglecting a particular energy source. This implies optimization procedures for the design of the process, based upon its actual kinetics.
This optimization has been developed in the present paper on the basis of experimental results on anaerobic digestion kinetics achieved in previous research.
In particular, optimal biogas production has been determined under ecological constraint due to sludge stabilization.
This procedure has proved that the volatile solids (VS) concentration in the digester feed must be kept above an allowable limit, which has been determined in the authors' research.
If the process design is also required to keep the pollutant concentrations of the outlet supernatant liquor within allowable limits, optimization of biogas “production factors” is no longer feasible because, in this instance, a single digester would work as a purifier rather than a biogas productive unit.
A Computer-Assisted Technique for Measuring KI-V Relationships
Authors: Coyle RT , Buhl ML 
Published: December 2008

We developed a computer-assisted data collection technique for flatjackloaded, short-rod specimens to readily obtain crack velocity V as a function of stress intensity factor KI. The technique facilitates the study of stress corrosion in glass and ceramic materials and allows us to determine the crack velocity at which the critical stress intensity factor is evaluated. The experimental apparatus included (1) a stepper motor to automate pressurization of the flatjack and (2) a digital oscilloscope to acquire information about the flatjack pressure and sample displacement at preselected time intervals.
We conducted fracture experiments using samples of soda-lime-silicate float glass and alumino-borosilicate glass (Corning 7809 Solar Glass) in an environmental chamber at 25°C and 30% relative humidity. We found that the critical stress-intensity factor for float glass, extrapolated to a crack velocity of 0.1 m/s, was 0.77 MPa m1/2 compared to 0.81 MPa m1/2 for the solar glass. Comparison of KI versus V data for the two glasses showed that the coefficient n in the empirical relationship V = AKIn is 27.5 for the solar glass and 18 for float glass.
The Effect of Binder Chemistry on the Fracture Toughness of Cemented Tungsten Carbides
Authors: Tingle JR , Shumaker CA , Jones DP , Cutler RA 
Published: December 2008

The fracture toughness of WC-10Co compositions with varying carbon concentrations were investigated. Both the material property, KIcSR and the apparent toughness, KQ, decreased rapidly upon the appearance of eta carbides in the microstructure. The amount of tungsten in the cobalt binder, as well as the presence of free carbon or eta carbides in the microstructure, affected the magnitude of the macroscopic residual stresses in the cermet.
The fracture toughness of compositions in which varying amounts of nickel had been substituted for cobalt were also investigated. It was found that up to 25% nickel could be substituted for cobalt without adversely affecting the fracture toughness or the hardness of the cermet.
Analytical Applications of Proton-Transfer Spectroscopy. Detection of Trace Hydrogen-Bonding Impurities in Hydrocarbon Solvents Using 3-Hydroxyflavone as a Fluorescence Probe
Authors: McMorrow D , Kasha M 
Published: December 2008

The photo-excitation steps in 3-hydroxyflavone leading to proton-transfer are described. The consequence of the ultra-rapid (&lt;8 ps) phototautomerization is the emission of a unique yellow-green tautomer fluorescence (λmax 525 nm) in hydrocarbon solution, instead of the violet fluorescence expected from the first UV absorption (onset λ 370 nm, first peak λ 354 nm). The tautomerization is intramolecular, involving the transfer of the hydroxyl hydrogen to the neighboring carbonyl group of the 3-hydroxyflavone molecule.
The analytical applications suggested by the qualitative spectroscopic features investigated result from the extreme sensitivity of the intramolecular H-bond to external solvent perturbations, which appear most strikingly in low-temperature spectroscopic studies as induced violet fluorescences of the H-bonded solvates. Using solute concentrations of 10−5 to 10−7 M, H-bonding impurities are detectable at substoichiometric concentrations. In the case of water in hydrocarbon solvents, the present experiments suggest that 10−7 to 10−9 M water may be detectable.
Ethers, alcohols, water, and other H-bonding solvents give characteristic violet solvate fluorescence band contours and peak positions, permitting qualitative discrimination of trace contaminants. The use of 3-hydroxyflavone as a fluorescence probe for solvent impurities is suggested. An application is made of isolated-site crystal matrix spectroscopy to determine the intrinsic low-temperature spectroscopic behavior of solutes, such as quinones and ketones, which can H-bond with trace impurities.
Developmental Researches on the Lightweight Structure for Future Satellite in the National Development Agency of Japan
Authors: Kawashima T , Yamamoto M , Yamawaki T , Yoshimura Y 
Published: December 2008

In recent years we are making some developmental studies on lightweight spacecraft structure and several lightweight components in National Space Development Agency of Japan (NASDA). Presented here are the test results of the structural components which were made of graphite fiber reinforced composites, carbon fiber reinforced composites, and aluminum alloy plate and honeycomb core, etc.
We describe the three items as well as the manufacturing process. First, graphite-epoxy tube trusses were manufactured and tested for use as struts and main frames of the satellite structure. Second, lightweight honeycomb panels were designed and fabricated to provide spacecraft structural components which are used as some equipment panels or stiffened panels. Third, lightweight solar panel was developed and tested for 3-axis stabilized spacecraft with sunoriented solar arrays which are expected to meet the power requirement of more than 1.8 kW. The panel has successfully been tested under acoustic noise environment, thermal cycling, and sinusoidal vibration, and thus qualified for space applicability.
Injection of Chemicals for Subsurface Drip Irrigated Cotton
Authors: Tollefson S 
Published: December 2008

Since 1980, Sundance Farms, Inc. has successfully grown three crops of cotton and one crop of wheat using subsurface drip irrigation systems. In evaluating drip on a commercial basis we have been able to increase yields by 36% to 50% and reduce total water use by more than half.
A large part of this success can be attributed to the injection of chemicals through the drip systems. Mechanical injectors have enabled the application of N-P-K fertilizers and chelated micronutrients directly to drip systems resulting in considerable flexibility and greater application efficiency. In addition, exceptional nematode control has been achieved with fumigants and contact nematicides siphoned into the systems. Injection systems for the introduction of sulfuric acid into pressurized drip systems has also been developed. The acid treatments have in part been responsible for three times the reduction of soluble salt levels in the soil. The continuous injection of acid has also helped in the maintenance of drip tubes by eliminating salt precipitation around the emitters.
A Low-Cost Microprocessor-Based Data Acquisition and Control System for Fatigue Crack Growth Testing
Authors: Sooley PM , Hoeppner DW 
Published: December 2008

The requirements for obtaining economic fatigue crack growth data from the threshold regime to instability in inert, gaseous, elevated-temperature, and aqueous environments necessitate the development of remote crack growth monitoring techniques. Two of these processes used extensively are the compliance method and the potential-drop method.
The performance of a microprocessor-based machine controller and data acquisition system utilizing the d-c potential-drop method of monitoring crack length is presented. The development of software for performing K-increasing and threshold tests and their compliance with the present ASTM standards are discussed. The successful development and use of the machine are shown by the results obtained during round-the-clock testing for acquiring crack growth data for a titanium alloy.
Computerized Single-Specimen J-R Curve Determination for Compact Tension and Three-Point Bend Specimens
Authors: Jablonski DA 
Published: December 2008

A computer-controlled test system was developed to measure J-R curves and JIc on compact tension and three-point bend specimens. The crack length was measured by unloading compliance. Improved crack length accuracy was obtained by amplifying the load and crack opening displacement (COD) signals by factors of 10 to 20 before the unloading. Crack length accuracy was further improved by collecting 500 data pairs on unloading using a fast data acquisition method. In the compact tension specimen, crack length and load-line displacement were measured with a load-line COD gage. In the three-point bend specimen, load-line deflection was measured using the crosshead deflection corrected for specimen and test fixture stiffness. An error analysis was performed to determine the crack length errors. The analysis showed the beneficial effect of using load and COD ranging to reduce the crack length errors.
J-R curves were measured on 17-4-Ph stainless steel heat treated to 948 MPa yield. The J-R curves were measured on two specimen geometries, compact tension and three-point bend, using four starting a/w ratios from 0.65 to 0.80 and three side groove depths, 0%, 12.5%, and 25%. The test results showed that in specimens with side grooves of 12.5% and 25%, the measured JIc-values were independent upon both specimen geometry and starting a/w ratio. The material tearing modulus, Tmaterial, was found not to be a material property since its value depended upon specimen geometry.
Industrial Systems Testing Using Heat Flux Transducers
Authors: Whitaker TE 
Published: December 2008

A heat flux transducer was calibrated on a guarded-end pipe tester and inserted under the jacket of an outdoor steam-heated pipe. The pipe was designed to allow the condensate to be collected and measured. The heat loss was calculated from the condensate volume and the thermal properties of steam. When compared with the heat loss measured by the transducer, agreement was within 6%.
The transducer output was recorded continuously over a one-year period. The average was obtained over a 24-h period to allow for comparison with average ambient weather conditions. Typically, the transducer output was inversely proportional to the average ambient temperature. Increasing wind speed reduced the surface temperature of the pipe and increased the average transducer output (heat loss).
Data are presented showing typical readings averaged over 1 h, 24 h, and two months. The data indicate that a heat flux transducer can be used to measure heat loss adequately in an industrial environment.
Heat Flow Sensors on Walls—What Can We Learn?
Authors: Flanders SN 
Published: December 2008

This paper addresses the validity of employing heat flow sensors (HFSs) on the indoor surfaces of building walls to determine thermal characteristics. It also reports on the results obtained in the field.
Some of the factors affecting HFS measurement accuracy (together with a likely percentage standard deviation attributable to that factor) are as follows: (a) the conductivities of HFS and its surroundings (3%), (b) convection mode changing over the sensor, causing a +21% bias (26%), (c) the mismatch of HFS absorptivity with the surroundings (6%), and (d) thermal contact of the HFS with the surface (1%). A propagation-of-errors analysis indicates that the resulting standard deviation of an HFS measurement would be approximately 10% of the mean of the measurements.
The R-value measurements of 20 buildings at four Army bases and installations demonstrated that the technique is repeatable—the same data time series with different start times results in the same R-value, side-by-side sensors give the same results (±5%), and different buildings of the same construction give similar results. Buildings whose construction was verified by boring into the wall gave measurements that agreed within 10% with the American Society of Heating, Refrigerating, and Air Conditioning Engineers (ASHRAE) calculations. Also, convection cells were very evident, even in insulated frame walls, necessitating a traverse of sensors from the top to the bottom of the wall.
With appropriate awareness of potential error sources, surface-mounted HFSs can render reasonable results.
Fabrication and Certification of Electroformed Microhardness Standards
Authors: Kelley DR , Johnson CE , Lashmore DS 
Published: December 2008

A commonly quoted characteristic of a material is its hardness. Accurate measurements of this characteristic require the use of precise standards to verify that the testing instrument, procedures, and comparisons with the results of another laboratory are accurate; however, it is recognized that currently available standards vary considerably in hardness from point to point across the surface. Electroplating technology was utilized to fabricate new microhardness standards. This technology provides a means for obtaining uniform hardness by close control of process variables which determine grain structure and composition.
Two microhardness standards are now in production—one with a hardness of ∼125 kg/mm2 and the other at ∼600 kg/mm2. The hardness values are certified at loads of 0.245, 0.490, and 0.981 N (25, 50, and 100 gf) with both Vickers and Knoop indenters. These electroplated materials have standard deviations in hardness, particularly at low loads, that are significantly better than the available standards. The fabrication of the new standards, their certification procedures, and testing instrument characteristics are discussed.
An Industrial Approach to Quality Assurance—Boring? You Bet! But Not If You Want to Make Money
Authors: Ziegel KD , Knox RE 
Published: December 2008

Quality assurance is that corporate function that negotiates and then monitors the implicit (and explicit) contract between the industrial customer and the manufacturer. Implementation of that function can and will depend on the structure of the corporate organization and on the nature of the industrial product. In the elastomers industry, we face a particular challenge: the products we manufacture must undergo not only a change in physical shape (forming by extrusion, molding, and so forth) but also a chemical transformation known as vulcanization. Quality assurance in the elastomers industry requires more complex testing and release procedures than are required for nonvulcanizable thermoplastics; test results are, in addition, highly dependent on compounding, heat history, and processing variability.
To meet these technical challenges, we have elected to organize our quality program in a hybrid fashion with responsibility for quality control (release and classification of product) located at the individual manufacturing sites and with quality assurance (negotiation of the customer/manufacturing contract) located in a single centralized laboratory equipped with up-to-date forming and vulcanizing equipment designed to simulate the customers' specific industrial processes. This approach maintains primary quality responsibility in the manufacturing organization, eliminates duplication of effort when several manufacturing sites are involved, and provides an effective representation of the specific needs of the customer and the market. Born of necessity in the elastomers industry, this concept of quality assurance/control can serve as a model for similar programs for other industrial products.
The Role of Interlaboratory Test Programs in Quality Assurance
Authors: Barnes JD 
Published: December 2008

A program for assuring the quality of products made from plastics is only as valid as the test methodology that supports it. Test methods can be characterized as to their repeatability and reproducibility. Both of these measures describe the level of precision, or agreement among test results, obtained when a test method is used to characterize a product, be it a raw material or a finished part. ASTM requires that each test method in the ASTM Book of Standards be provided with a statement of precision and accuracy. This paper describes some recent efforts within Committee D20 on Plastics to assess the precision of two test methods. The results are analyzed using ASTM Practice for Conducting an Interlaboratory Test Program to Determine the Precision of a Test Methods (E 691).
The implications of the measured precision of the test methods for their use in quality assurance activities are described.
Hydrogen Embrittlement of Zimaloy: A Cobalt-Chromium-Molybdenum Orthopedic Implant Alloy
Authors: Edwards BJ , Louthan MR , Sisson RD 
Published: December 2008

Controlled potential, slow strain rate tests of Zimaloy (a cobalt-based orthopedic implant alloy) in Ringer's solution (a physiological saline solution) at 37°C show that hydrogen absorption may degrade the mechanical properties of that alloy. Potentials were controlled so that the tensile sample was either cathodic or anodic with respect to the metal's free corrosion potential. Hydrogen was generated on the sample surface when the specimen was cathodic, and dissolution of the sample was encouraged when the sample was anodic. The results of these controlled potential tests showed no susceptibility of this alloy to stress corrosion cracking at anodic potentials.
However, when samples were tested at a potential of 150 mV cathodic to the free corrosion potential, the difficulty was decreased by 37%. The 150-mV shift in potential was selected because that was the potential observed when this alloy, in a creviced condition, was placed in Ringer's solution for two months. Support for this reduction in ductility during the cathodic exposures was obtained by testing the hydrogen compatibility of the alloy. Samples charged in gaseous hydrogen showed significant losses in ductility. The most severe hydrogen charging (207 MPa at 300°C for ten days) reduced the tensile ductility to 0% reduction in the area at fracture while less severe charging (6.9 MPa at 200°C for seven days) caused a 50% decrease in ductility. Results of these tests indicate that this cobalt-based alloy suffers a significant loss in ductility under conditions that may arise if a creviced sample is exposed to saline solutions.