bluuebunny/crossref_metadata_2025 huggingface dataset:
Merits of Metallized Film Constructions
Authors: Skodis LC
Published: December 2008

This paper discusses the advantages of metallized films, which provide a wide range of options for innovation and consumer appeal and service, along with cost savings, for the alert converter and packaging material user. The vacuum metallizing process is described, uses of metallized films are discussed, and comparisons are made between metallized films and other packaging materials.
High-Barrier Flexible Polyvinylidene Chloride Composite Applications
Authors: Samuels JE
Published: December 2008

Saran polymers, polyvinylidene chloride (PVDC)/vinyl chloride copolymers, have long been known for excellent barrier characteristics against both water vapor and oxygen permeation.

This paper covers the development of a new high-barrier PVDC copolymer film (HBPVDC) for lamination use. The film is about ten times more resistant to oxygen transmission and about five times better a barrier to moisture passage than regular Saran film.

Laminations including HBPVDC films as the barrier ply offer a transparent alternative to foil and metallized structures. In addition, HBPVDC laminations have excellent flex performance characteristics while maintaining barrier properties.

Structures can be designed for cooking foods in a microwave oven or in retort pouches. Food packages in HBPVDC laminates may also be used in conjunction with metal detectors for tramp metal detection.

Applications of high-barrier laminates include snack food, drug, and pharmaceutical packaging; retort pouches for food and medical packaging; and bag-in-box packaging for liquids and industrial uses.
Polycarbonate Coextrusions for Barrier Flexible Packaging
Authors: Rohn BA
Published: December 2008

This paper evaluates the benefits of polycarbonate resin as a structural layer in high-barrier coextrusions for flexible packaging. High-temperature performance requirements are examined for hot-fill, retort, autoclave, and ovenable packaging. Coextrudable barrier resins and tie layer resins are evaluated for processability, and the benefits of low- and high-moisture barriers are compared in composites using moisture-sensitive oxygen barrier resins. Optimum barrier composite structures are defined and evaluated.
Inactivation of Microorganisms on Polyethylene Exposed to Hydrogen Peroxide Vapors in Air at Various Temperatures
Authors: Wang J , Toledo RT
Published: December 2008

Air saturated with hydrogen peroxide vapor in equilibrium with 35% (weight/weight) aqueous hydrogen peroxide solution possesses sporicidal properties suitable for use as a sterilant in aseptic packaging systems. At 70°C, a six-decimal reduction in population of Bacillus subtilis A and Bacillus subtilis var. globigii can be achieved after 0.95 and 1.2 min of exposure, respectively. Hydrogen peroxide vapor is adsorbed by the polyethylene surface. The adsorbed quantity that persists following 99.9999% inactivation of B. subtilis var. globigii decreased with increasing temperature. Without further treatment, residues will exceed the legal tolerance.
High-Performance Liquid Chromatography and Its Application to Flexible Packaging Materials
Authors: Richmond ML , Harte BR
Published: December 2008

High-performance liquid chromatography (HPLC) is a powerful analytical tool which has application to flexible packaging materials. The technique can be used for qualitative and quantitative evaluation of material components and processing variations and for physical characterization. Speed, versatility, accuracy, and sensitivity can be achieved by judicious selection of equipment components and separation techniques. HPLC applications to flexible packaging materials are described.
Use of Differential Scanning Calorimetry in Developing and Applying Films for Flexible Packaging
Authors: Dunn TJ
Published: December 2008

The fundamentals of differential scanning calorimetry (DSC) are presented, with particular emphasis on polymer systems used in flexible packaging. The use of DSC techniques to distinguish film properties from the properties of base polymers is described. Techniques for quantitative determination of melting points, percentage composition of dry-blended film resins, and latent heat of fusion are given. Qualitative analysis of crystallinity characteristics is described.

Application of these analytical techniques to considerations of film extrusion, extrusion coating, and heat seal performance demonstrates the value of DSC in selecting and characterizing films used in flexible packaging.
Coating EPA-complying Waterborne and 100% Solid Flexible Laminating Adhesives
Authors: Caimi RJ , Fries JA
Published: December 2008

Flexible packaging converters are increasingly using U.S. Environmental Protection Agency (EPA)-complying adhesives, in aqueous and 100% solid forms. Aqueous grades are applied with the same direct gravure coating stations used for solventborne systems; 100% solid types are applied by offset gravure. In both cases, new variables are introduced related to these less familiar forms. Wet-out, the coating quality, and the initial bond strength are affected. The variables must be understood and adjusted for optimum results. These variables fall into three groups. Some directly involve the adhesive, such as surface tension and vehicle-release characteristics; others involve the substrate, most important, the surface free energy. Coating equipment variables such as heat transfer at the laminating nip make up the third group.
The Modes of Appearance and Their Attributes
Authors: Hunter RS
Published: December 2008

To evaluate the appearances of objects and materials, it is necessary to assess both color and geometric attributes of appearance. Color stimuli can be synthesized by mixing proper amounts of three primary colored lights to match visually any unknown. Color is thus tridimensional. By contrast, the geometric attributes (gloss, texture, and distinctness-of-image) cannot be synthesized. Instead, different perceived attributes are selected on the basis of best correlation of measurement results with visual ratings. The best measurement methods are identified by ASTM and other organizations. In practice, however, only the most obvious sources of geometric appearance differences can be measured.

Complete analyses of geometric appearance, based on all directions of light distribution, would be too cumbersome to be usable.
A Colorimetric Determination of Dye Content on 100% Polyester Fabrics
Authors: Hauch LA , Glicksberg S , Yeh K-N
Published: December 2008

Colorimetric determinations of dye contents on polyester fibers evolved as a viable alternative to many hours of determining dye contents on fibers by soxlet extractions. Experimental work indicates a simple linear relationship between the amount of dye on the fabric and the color “appearance” of the fabric (as measured by a colorimeter). Varying dyeing procedures and dye carriers showed negligible effects on the correlation. Therefore, varying the penetration and fixation of the dye in the fiber were unimportant factors in this type of measurement. The established calibrations only relate to systems using identical fabric-dye combinations since both the dye and the fiber will affect colorimetric readings. The technique is applicable to any combination of fabric and dye (except pile fabrics), given the appropriate calibration. Where repeated determinations of dye contents on large quantities of similarly dyed fabrics will be required, colorimetric dye content determinations will save time and money.
On the Specification of Heterochromatic Brightness
Authors: Cowan WB
Published: December 2008

For many years it has been known that luminance, the CIE quantity best correlated with perceived brightness, does not work well for many colors. Consequently, the CIE charged a technical committee to find a better solution. The National Research Council of Canada, responding to the committee, has produced a function that can be used to correct luminance to produce predictions for brightness matches. This function, which is empirical, based on the extensive data that have been taken on brightness, is summarized in this report.
Functional Formulation for Prescription Performance
Authors: Kotz ME
Published: December 2008

Pesticide formulations generally comprise three objectives: convenience of physical properties, ease of application, and biological activity. Economic necessity frequently dictates that a fourth objective, maximum utility (i.e., the fewest formulations for the greatest number of proposed uses), be considered. An overemphasis of the latter can result in significant reductions of overall pesticide performance, particularly in specialized applications. Several case histories of formulations are presented that demonstrate the advantages of proper definition and prioritization of the compromising criteria before initiation of formulation development.
Effect of Droplet and Formulation Parameters on Pest Control Efficiency
Authors: Hall FR
Published: December 2008

The effect of droplet density and toxicant concentrations on the mortality and behavior of two-spotted spider mites was evaluated in a laboratory study. Residues of fenvalerate and cyhexatin under certain droplet densities resulted in an increase in oviposition. A formulation of permethrin (encapsulated) was found to have the same toxicity as the standard formulation to both apple aphid and Japanese beetle. However, the encapsulated formulation resulted in a loss of hyperactivity and repellancy shown by the standard formulation of permethrin.
Evaluation of Water Soluble Polymers as Co-Suspending Agents for Flowable Pesticides
Authors: Modi JJ
Published: December 2008

This work was done to evaluate water soluble polymers (WSP) as cosuspending agents with a commercially available inorganic thickening agent, Van Gel B, for the suspension of pesticide particles in agricultural flowable formulation.

Solutions of WSPs and Van Gel B were evaluated at several concentrations for viscosity stability, compatibility, and determination of yield value. A high yield value at low viscosity is desired for good suspension stability with ease of application. The solutions were prepared in commercial high-speed mixing equipment. The slurries were mixed for three minutes at high speed and then for three additional minutes at low speed. Specific blends of carboxymethyl cellulose (CMC) and Van Gel B provide satisfactory yield at low viscosity.

Optimized CMC/Van Gel B blends having high yield values and relatively low viscosities have been further evaluated in actual flowable pesticide formulations. Evaluations in these systems have shown promising results when compared with commercial formulations. Tests such as viscosity stability, solution stability, bloom, suspension, and pH were performed.
Practical Applications of the Particle Measuring Systems Two-Dimensional Imaging Spectrometer
Authors: Young BW
Published: December 2008

The Particle Measuring Systems two-dimensional PMS 2-D system has been successfully used in a wide variety of applications: for fundamental research, for quality control, and for field work. A number of features of the system make it particularly suitable as a versatile, robust tool for studying spray clouds of toxic materials; yet it can also be used as a highly refined tool for fundamental studies on single droplets. The ability to simultaneously measure droplet size and velocity is a particular advantage of the system.

As with any measuring technique it is necessary to accept the limitations of the system, the necessary precautions in its use, and to correctly interpret the data. Work on calibration of the system has led to a custom-designed graticule being made and to the possibility of a standard to be used on each instrument. This would create a new level of uniformity between the various user groups. Initial cross-calibration work with the Malvern system has also shown the possibility that meaningful comparisons between the different techniques may be made.
Titanium as Anode (and Cathode) Substrate Material for Industrial Electrolytic Applications
Authors: Woo MYC
Published: December 2008

The use of titanium as a conductive electrode substrate for industrial electrolytic applications began in the late 1960s when the so-called dimensionally stable anodes technology was commercialized for chlor-alkali production. Pioneered work by researchers, such as Cotton and Beer as far back as the 1940s through 1950s, recognized the fact that the passive oxide layer formed on titanium at high temperatures could be made conductive by doping the oxide with platinum group metals. The surface titanium oxide congruent with the precious metal oxide resulted in solid solution formation, and electrodes produced this way demonstrated unique electrochemical properties. It is the purpose of this paper to review some of the major advantages and limitations of dimensionally stable electrode technology. This review will be applications oriented and is targeted to provide an in-depth look at titanium as an electrocatalyst support for effecting electrolysis or other electrochemical reactions.
The Application of Titanium and Its Alloys in Alkali Chloride and Refined Salt Industries
Authors: Zuochen L , Qingzhi W , Xiamei S , Kaibing L
Published: December 2008

This paper describes the history, present condition, and prospect of applications of titanium and its alloys (Ti-Grade 12) in the alkali chloride and refined salt industries.
Titanium for Flue Gas Desulfurization (FGD) Systems: Testing and Evaluation
Authors: Young CS , Schutz RW , Grauman JS
Published: December 2008

Titanium is now beginning to be seriously considered as a material of construction for power plant flue gas desulfurization (FGD) scrubber systems. Corrosion problems have limited the effectiveness of even super-stainless and high nickel alloys, widely used in the last few years for FGD scrubber construction, while initial testing of titanium has shown it to be highly resistant to corrosion in the acidic chloride conditions of FGD systems.

This paper reviews the results of in-situ testing of titanium stainless, and nickel alloys in FGD scrubber systems, providing a basis for comparing relative alloy performance. The results are correlated with the findings of other in-situ tests as well as laboratory tests simulating the FGD scrubber environment.
Zirconium for Nitric Acid Solutions
Authors: Yau T-L
Published: December 2008

The excellent corrosion resistance of zirconium in nitric acid has been known for over 30 years. Recently, there is an increasing interest in using zirconium for nitric acid services. Therefore, an extensive research effort has been carried out to achieve a better understanding of the corrosion properties of zirconium in nitric acid. Particular attention is paid to the effect of concentration, temperature, structure, solution impurities, and stress.

Immersion, autoclave, U-bend, and constant strain-rate tests were used in this study. Results of this study indicate that the corrosion resistance of zirconium in nitric acid is little affected by changes in temperature and concentration, and the presence of common impurities such as seawater, sodium chloride, ferric chloride, iron, and stainless steel. Moreover, the presence of seawater, sodium chloride, ferric chloride, and stainless steel has little effect on the stress corrosion cracking (SCC) susceptibility of zirconium in 70% nitric acid at room temperatures. However, zirconium could be attacked by fluoride-containing nitric acid and the vapors of chloride-containing nitric acid. Also, high sustained tensile stresses should be avoided when zirconium is used to handle 70% nitric acid at elevated temperatures or > 70% nitric acid.
Fundamental Corrosion Characterization of High-Strength Titanium Alloys
Authors: Schutz RW , Grauman JS
Published: December 2008

Many commercially available and several developmental high-strength titanium alloys were evaluated for application in chloride-containing environments with respect to general, crevice, and stress corrosion resistance. Studies in boiling reducing and oxidizing acid chloride media permitted identification of certain high-strength titanium alloys, containing ≥ 4 weight % molybdenum, which are significantly more resistant than unalloyed titanium with respect to general and crevice attack. Data regression analysis suggests that molybdenum and vanadium impart a significant positive effect on alloy corrosion resistance under reducing acid chloride conditions, whereas aluminum is detrimental. Little effect of metallurgical condition (that is, annealed versus aged) on corrosion behavior of the higher molybdenum-containing alloys was noted. No obvious susceptibility to chloride and sulfide stress corrosion cracking (SCC) was detected utilizing U-bend specimens at 177°C.
Beta-C: An Emerging Titanium Alloy for the Industrial Marketplace
Authors: Thomas DE , Ankem S , Goodin WD , Seagle SR
Published: December 2008

Ti-38-6-44 (also known as Beta-C®) is a heat treatable, deep hardenable beta titanium alloy capable of ultimate strengths in excess of 1380 MPa (200 ksi). Its attractive properties include low elastic modulus, good ductility and toughness, light weight, excellent corrosion resistance, and good fabricability. The alloy's metallurgy and physical properties are reviewed. Special emphasis is given to those properties important in corrosion-related industrial applications.
Zirconium Fabrication and Junction Between Zirconium or Titanium and Stainless Steel
Authors: Decours J , Demay R
Published: December 2008

The procedures employed in irradiated fuel reprocessing installations have led to the use of zirconium for the fabrication of certain components because of its excellent behavior in nitrate solutions. This paper deals with (1) the forming of zirconium from semi-finished products, forming limit curves for deep drawing, hydroforming, and isostatic forming; (2) the weldability of large size zirconium, components outside the glovebox, influence of structural modifications on mechanical properties; and (3) the design of heterogeneous joints required for connection to the austenitic stainless steel pipes.
Status of Titanium Net-Shape Technology
Authors: Vogt RG , Eylon D , Froes FH
Published: December 2008

The status of net-shape technologies in the titanium industry is reviewed in this paper including powder metallurgy, casting, and isothermal precision forging. Although titanium and its alloys are a design choice for many industrial and aerospace applications, use is still limited because of the relative high component cost, the result of high material processing, and machining costs. Net-shape technologies are an attractive avenue for reducing the cost without sacrificing properties and reliability. The three approaches to titanium net-shape technology offer a range of shape and property combinations. Titanium casting and isothermal precision forging are already an industrial reality and powder metallurgy is rapidly reaching such a position. The isothermal precision forging and powder metallurgy net-shape approaches not only offer lower cost and reduced material use, but also provide some mechanical properties superior to conventional products because of microstructural homogeneity and refinement.
Quality Control Considerations in the Selection of Well Design, Drilling Procedures, and Well Construction Materials
Authors: Henne MS , Meinert WW
Published: December 2008

Groundwater monitoring wells are used extensively in the United States to detect and monitor plumes of contamination. Only with proper installation can the environmental scientist ensure that representative water samples are collected and that well installation will not contaminate “clean” aquifers. Options for drilling methods and well materials are discussed and their strengths and weaknesses are weighed.
A Review of Quality Control Considerations in Soil Sampling
Authors: Bruner RJ
Published: December 2008

Precision, accuracy, and representativeness of samples are as important in soil sampling programs as these considerations are for other quality assurance programs. Proper procedures for cleaning and preparing sampling equipment and containers, selecting sampling sites, sample collecting and handling, and laboratory quality assurance/quality control should be observed to preserve the integrity of soils analyses.
Preliminary Monitoring Design for Metal Pollution in Palmerton, Pennsylvania
Authors: Starks TH , Brown KW , Fisher NJ
Published: December 2008

Large concentrations of the metal soil pollutants, cadmium, copper, lead, and zinc, have been detected in and around Palmerton, Pennsylvania. Before a cleanup of the area can be undertaken, it will be necessary to map the spatial distribution of the concentrations of the pollutants over the area. Then boundaries can be determined for the regions that are above and below action levels. The estimation of the spatial distributions of the metal concentrations, with a prespecified level of precision, requires a definitive soil-sampling survey. The intensity of sampling (i.e., distance between sample points) needed to attain the prespecified level of precision will depend on the nonsampling error variance and the spatial structure of the concentration measurements. To determine the nonsampling error variance and the spatial structure, a preliminary soil-sampling study is required. This paper discusses the planning of such a preliminary study.
Volatile Organic Analytical Methods — General Description and Quality Control Considerations
Authors: Fisk JF
Published: December 2008

As a result of the enactment of the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA) in 1980, and the subsequent delegation of its Authority by the President of the United States to the Administrator of the Environmental Protection Agency, the Contract Laboratory Program (CLP) has been developed to analyze “Superfund” samples in a broad-based manner in order to obtain the most information about these samples with a reasonable investment in time and money. The CLP uses gas chromatography/mass spectrometry (GC/MS) as its primary tool for analysis of samples for organic constituents. More explicitly, it employs purge and trap techniques prior to MS detection for analysis of samples for volatile compounds. An elaborate Quality Assurance/Quality Control (QA/QC) system is in place to guarantee that data generated by the CLP is of known quality and will hold up to the rigors of litigation in addition to providing an ongoing monitoring of CLP laboratories QA/QC data in order to guarantee their successful performance.
Pesticide Analytical Methods — General Description and Quality Control Considerations
Authors: Marsden PJ , Pearson JG , Bottrell DW
Published: December 2008

Environmental samples are analyzed for organochlorine pesticides/PCB's as part of the Environmental Protection Agency's (EPA) Superfund Contract Laboratory Program (CLP). A new protocol is required because laboratories have difficulty meeting the present data acceptability criteria and because the surrogate now used is more chemically labile than the analytes determined with the protocol. The new pesticide/PCB protocol specifies an ultrasonic extraction procedure for soil and either continuous liquid-liquid or separatory funnel extraction of water. It describes clean-up procedures using gel permeation chromatography, adsorbtion columns and mercury, copper or tetrabutylammonium sulfate for sulfur removal. The protocol requires a dual gas chromatography (GC) column quantitation of 17 single component pesticides and nine multicomponent pesticides/PCB's using electron capture detection (ECD). The quality assurance/quality control (QA/QC) requirements include 12-hour GC performance checks, instrument and method blank requirements, matrix spike/matrix spike duplicate analyses every 20 samples and periodic performance checks of clean-up techniques. Validation of the protocol is being accomplished according to EPA guidelines for determining ruggedness, precision, bias, detection limits, and sensitivity.
A Preliminary Assessment of the Importance of Littoral and Benthic Autotrophic Communities in Acidic Lakes
Authors: Crisman TL , Clarkson CL , Keller AE , Garren RA , Bienert RW
Published: December 2008

Most of the research examining changes in aquatic biota relative to increasing acidity has concentrated on pelagic components. The possible influence of littoral-pelagic interactions on observed relationships has largely been ignored, and thus interpretation of pelagic biotic data unfortunately often is taken out of context of the whole ecosystem. While littoral and benthic communities are major contributors to the autotrophic production of small lakes in general, it is likely that their share assumes greater importance in acidic lakes where phytoplankton are often severely nutrient-limited. The availability of nutrients in the pelagic zone of acidic lakes may be regulated by littoral and benthic processes. Available data suggest that while the structure of littoral and benthic autotrophic communities has a direct influence on benthic invertebrates, it exerts an indirect control on zooplankton and fish principally through the quality and quantity of habitat and food resources. Future investigations of biota in acidic soft-water lakes should concentrate on quantifying such littoral-pelagic linkages.
Linking Automated Biomonitoring to Remote Computer Platforms with Satellite Data Retrieval in Acidified Streams
Authors: Morgan EL , Eagleson KW , Weaver TP , Isom BG
Published: December 2008

Recent advances in site-specific detection of fish's physiological responses to continuous stream flows now complement surveillance programs utilizing remote automated water quality monitoring stations. Developments in automated biosensing provide methods for measuring in situ fish breathing rate changes to stream episodes and add a real-time biological monitoring dimension to remote water quality networks incorporating automated data collection platforms and satellite data retrieval options.

In meeting our objective of developing automated biosensing capabilities for remote monitoring, a series of field trials was designed to test various configurations of in situ fish-holding chambers, breathing rate detectors, and system interface to streamside water quality data collection platforms for satellite data retrieval.

Results were used to design groups of automated biosensing devices for detecting rainbow trout breathing rate responses and to implement eight units at each of two data collection, platform-equipped, water quality stations located along a stream subject to acid precipitation influences in the Southern Appalachian Mountains. Remote stations are being maintained for real-time data needs as a part of the 5-year Acid Precipitation Mitigation Program initiated in 1985 by the U.S. Fish and Wildlife Service to evaluate stream ecological responses to regulated liming operations.
Consideration of Total Ion Composition in Designing Toxicity Tests Using Aluminum Salts and Mineral Acids
Authors: Young RC
Published: December 2008

Review of the current literature reveals that many researchers involved in the study of the effects of aluminum and pH on aquatic life are using aluminum salts, that is, sulfate or chloride forms, to obtain the desired aluminum concentration for their experiments. This technique raises some concern for soft water experiments due to the unknown effect of excessive concentrations (in relation to background) of the associated anions SO4= or Cl−. For example, if aluminum chloride (AlCl3) is employed to obtain a concentration of 0.5 mg/L aluminum, the solution also will be increased by 2.0 mg/L Cl−. Likewise, if aluminum sulfate [Al2(SO4)3] is used to achieve the 0.5 mg/L aluminum, SO4= will be increased 2.6 mg/L. For inland streams (that is, not affected by ocean salts), these values appear to be out of proportion. In some instances the use of aluminum salts can easily double or increase by the power of 10 the concentrations of associated anion. SO4= or Cl− concentrations are further increased by the use of sulfuric and hydrochloric acid to adjust pH. Since aluminum is an effective buffer below pH 5.0, solutions containing high concentrations of aluminum also will require larger volumes of acid to achieve pH values below this level, thus compounding the problem.

The question of acid form, that is, sulfuric, hydrochloric, nitric, etc., in relation to toxicity leads to the consideration that these “strong acids” are only one component contributing to the total acidity of a system. In coniferous forests with deep acid soils, storm water runoff could contribute significantly to the acidity of streams due to fulvic acids. Their chelating ability also could enhance the mobilization of aluminum. How these weak organic acids affect or regulate pH or pH/aluminum toxicity in fish is also unknown.

The paper discusses the importance of total solute concentration and the possible role specific anions play in mediating osmoregulation in acid- and acid/aluminum-stressed fish.
Opportunities with Alkalies in Concrete Testing, Research, and Engineering Practice
Authors: Idorn GM , Roy DM
Published: December 2008

From about 1940 alkalies have been known as a potentially important species in concrete, despite being a minor cement constituent. The hydration reaction of silica in aggregates in concrete in the presence of alkalies, which may cause deleterious expansion, is chemically similar to the process which makes finely ground cementitious components, such as blast-furnace slag, and mineral admixtures, such as fly ashes, natural pozzolana, and silica fume, able to prevent expansive reactions.

The chemistry of this process is briefly reviewed, and the impact of elevated temperatures, which occur more often in field concrete than in laboratory concrete and mortars, is discussed.

The advantageous effects of alkalies on the rheology of concrete containing mineral admixtures are discussed with reference to recent research regarding the electrochemistry of cement paste. The corresponding effect in densifying the microstructure of the cement paste in hardened concrete is also discussed.

Updating of the application of silicate chemistry is proposed as a basis for development of testing tailored to serve effectively the increased uses of the mineral admixtures.
A Model of Metal Ignition Including the Effect of Oxide Generation
Authors: Yuen WW
Published: December 2008

A theoretical model is presented to simulate the general behavior of the metal ignition process. The model includes many physical mechanisms (such as the various heat transfer rates, reaction rate, and the effect of oxide formation on the reacting surface) that are known to have influence on metal ignition. Based on numerical solutions, three separate types of metal ignition are identified. They are (1) external heating controlled ignition, (2) convection controlled ignition, and (3) convection and transition temperature controlled ignition. For certain types of metal ignition, such as the external heating controlled ignition, the ignition temperature appears to be an ineffective parameter in illustrating the relative ignitability of the different materials. For such cases, the concept of a minimum ignition heat flux is shown to be useful in correlating the relative ignitability.

Test data for five different alloys generated from the friction-rubbing test apparatus at the White Sands Test Facility are analyzed based on the present model. Qualitatively, almost all observed ignitions are shown to be external heating controlled. Tests with lower rotational speed and higher oxygen pressure are needed to determine the minimum ignition heat flux for the five alloys. Based on the current set of data, some conclusions concerning the minimum ignition heat flux of Type 316 SS and a preliminary ranking of the five alloys in terms of their relative ignitability are generated. These conclusions, however, require further verification by additional test data.
The Use of the Accelerating Rate Calorimeter in Oxygen Compatibility Testing
Authors: McIlroy K , Zawierucha R
Published: December 2008

A number of different test methods have been utilized to assess the compatibility of various materials or substances with oxygen. Accelerating rate calorimetry is a relatively new analytical technique that has been used to detect adiabatic, self-heating reactions at rates as slow as 0.03°C/min. In this study six materials were tested by the accelerating rate calorimeter and the conventional autoignition apparatus in oxygen over a wide range of pressures.

The results showed that exothermic reactions can occur well before the autogenous ignition temperature (AIT) for some materials. For example, nitrile rubber demonstrated that the onset of adiabatic self-heating occurred about 40 to 53°C below the AIT, and “MOBIL“ DTE 25 compressor oil showed a range of 38 to 73°C below AIT in the 13.6- to 36.7-MPa (2000- to 5400-psi) pressure range.
A Pressure Vessel Hatch Cover Failure: A Design Analysis
Authors: Kaplan MP , Willis T , Barnett RL
Published: December 2008

This case study involves a hatch cover located on a pressurized barge unloading concrete. The hatch cover exploded as a workman was kicking off one of the locking cams holding the cover to the deck. The cover, attached to the barge by a hinge, utilized six locking cams to hold the pressure seal to the compartment. The cover was 0.51 metres in diameter and fabricated from A356-T6 aluminum. The pressure to off-load the cement was 206.8 kPa. A finite element study was performed to determine the stresses in the cover as a function of locking geometry. Fracture toughness tests to determine KIc, a nondestructive inspection to determine crack size and crack population, and a design study to determine pressure vessel design characteristics were undertaken. A failure analysis was also conducted. Results of the studies indicate that the design choices (internal piping, hatch cover attachment, and material selection) allowed a potentially catastrophic situation to develop. Recommendations for design improvements are given.
Analysis of the Unstable Fracture of a Reactor Pressure Tube Using Fracture Toughness Mapping
Authors: (Peter) Chow CK , Simpson LA
Published: December 2008

On 1 August 1983, a Zircaloy-2 pressure tube in Ontario Hydro's Pickering-2 reactor failed by the unstable propagation of an axial crack. The reactor was quickly and safely shut down, without the need for any emergency cooling, and an extensive investigation into the event was initiated. One factor requiring explanation was the apparent failure of the leak-before-break principle, that is, why was the initiating flaw not detected by leakage prior to growing to an unstable size? This paper describes part of a program to address this question, which involved mapping the fracture toughness of the pressure tube as a function of position over the cracked region. The results of the fracture toughness mapping, plus selected fractography, are used to explain the sequence of events that occurred during the tube failure.
Preventing Fracture By Inspection and Analysis
Authors: Selz A , Peterson DB
Published: December 2008

A problem in operating pressure components under cyclic loading conditions is establishing an in-service inspection frequency to assure continued operability without threat of catastrophic failure. For some extremely high pressure components, this has been done on a rational basis by (1) establishing the regions of highest stress, usually thread roots or other local stress raisers in a high stress field, (2) establishing the minimum-size reliably observable crack-like defect, using proven inspection means, such as magnetic particle or eddy current testing, and (3) determining the number of design cycles this minimum observable crack needs to grow to critical size, using Paris law or analogous crack propagation relations, and then dividing the resulting number of cycles by a factor of at least three. This factor of three is based on retaining cyclic margin to failure, even if a given defect is below perceptible size at initial inspection and is missed during the next inspection. A factor of four would accommodate two consecutive failures to observe a defect. Methods have been also developed which permit modification of the inspection interval if the operating logs show the imposition of a distribution of operating cycles other than the design cycles upon the component.

The methods described were originally developed and applied to predicting safe life and establishing inspection intervals for a hypervelocity wind tunnel. They have since been applied to commercial pressure vessels and for recertification of pressure vessels for the National Aeronautics and Space Administration.
The Markham Mine Disaster
Authors: Demaid APA , Lawley A
Published: December 2008

The authors have applied linear elastic fracture mechanics to an official accident investigation of a fatigue failure. A single-line component in the mechanical braking system controlling the descent of a cage in a mine shaft fractured; the cage failed to slow down and eighteen miners were killed by the impact. It is shown that significant perceptions of the events prior to fracture are possible using a fracture mechanics approach. A Paris-Erdogan analysis is performed to highlight the constraints and limitations of a fracture mechanics fatigue analysis when applied to a real engineering problem. The Markham accident was a landmark case study in that it stimulated a new philosophy with respect to brake design.
The OSHA Hazard Communication Standard
Authors: McDaniel DW
Published: December 2008

On 25 Nov. 1983, The Occupational Safety and Health Administration (OSHA) issued a final rule on hazard communication. This final rule represents over ten years of rule-making activity. The purpose of the Hazard Communication Standard is to ensure that hazards of all chemicals produced or imported by chemical manufacturers are evaluated and that the information on these chemical hazards is transmitted to employers and employees within the manufacturing sector.

Employers in the manufacturing sector [Standard Industrial Classification (SIC) Codes 20–39] are to provide information to their employees about hazardous chemicals by means of a hazard communication program, labels and other forms of warning, Material Safety Data Sheets, and information and training. The purpose of the Hazard Communication Standard is threefold:

1. To ensure that the chemicals produced or imported or both by chemical manufacturers and importers are evaluated to determine their hazards.

2. To provide information about hazardous chemicals to all employers and employees in the manufacturing sector.

3. To establish uniform requirements nationwide by preempting state right-to-know laws applicable to the manufacturing sector. A state may assume responsibility in this area only through the provisions of Section 18 of the Occupational Safety and Health Act.

The standard applies to chemical manufacturers, importers, distributors, and employers in the manufacturing sector in SIC Codes 20 through 39. In addition, the standard applies to any chemical known to be present in the workplace in such a manner that employees may be exposed under normal conditions of use or in a foreseeable emergency. There is limited coverage for laboratories as well as exclusions for certain products.

There are six major elements of the Hazard Communication Standard:

1. Hazard assessment—the hazards of chemicals must be evaluated by chemical manufacturers and importers. The information must be passed on to employers in the manufacturing sector who purchase the hazardous chemicals.

2. Hazard communication program—employers covered by the regulation must develop a hazard communication program to transmit information on hazardous chemicals to their employees.

3. Labels and other forms of warning must be placed on containers of hazardous chemicals.

4. Materials Safety Data Sheets must be developed to transmit hazard information to the manufacturing employees and employers.

5. Employee information and training must be provided. This includes identifying work operations where hazardous chemicals are present as well as means that employees can take to protect themselves.

6. Trade secret provisions—there are provisions for the release and protection of trade secret information.
Labels and Material Safety Data Sheets in Hazard Communication
Authors: Freifeld M
Published: December 2008

In the Hazard Communication Standard (HCS), the Occupational Safety and Health Administration (OSHA) chose labels, Material Safety Data Sheets (MSDSs), and training as the vehicles for conveying to workers information about hazards on the job. Labels have always been aimed at the worker. MSDSs, on the other hand, have been written largely for health professionals. Training should, therefore, include the meaning of technical terms in labels and MSDSs so that workers can understand them.

A label is intended to provide an immediate warning about hazardous materials in the workplace. It may be in written or graphic form and must be tied in with training and MSDSs. The label must include the identity of the hazardous chemicals and appropriate warnings about the hazards. The label format is optional, and existing systems may be used. Some alternatives to labeling are allowed, such as large posters describing contents and hazards of a series of similar reactors. Chemical manufacturers, importers, and distributors must also include the name and address of the manufacturer of materials being shipped out of a plant. Substances covered by other federal laws are exempt from HCS's shipped container labeling requirements.

MSDSs complement the label and are more complex. They include: (1) the identity used on the label (except trade secrets) and the specific chemical identity of the hazardous ingredients; (2) physical and chemical characteristics of hazardous materials; (3) fire, explosion, and reactivity hazards; (4) health hazards—both short- and long-term; (5) safe handling and use procedures; (6) emergency and first aid procedures; and (7) date and name of the responsible party preparing the MSDS.

The Hazard Communication standard requires chemical manufacturers to make MSDSs available to their employees. It also requires them to supply MSDSs to downstream manufacturing employers, who in turn must make them available to employees. Clearly then, the chemical manufacturers face the challenge of preparing complete MSDSs. Manufacturing employers must be sure that their workers do indeed get the message.
Hazard Communication in Other Jurisdictions: A Proposed Canadian System
Authors: Geoffrey C. Granville
Published: December 2008

The Workplace Hazardous Materials Information System (WHMIS) was initiated as a tripartite project in 1982, and a final report was submitted to government during 1985. The report recommends an approach to the communication of hazardous properties of materials used in the Canadian workplace that is broadly similar to the OSHA Hazard Communication standard, although there are some notable differences.

At the time of publication, the report had not resulted in any new regulatory initiative.
Instrumented Impact Test Data Interpretation
Authors: Cheresh MC , McMichael S
Published: December 2008

This paper provides a guide for those becoming acquainted with instrumented impact testing and faced with acquiring accurate data and subsequently evaluating it. The discussion deals with (1) preparation of the system for data collection and (2) evaluating the data collected. The system preparation discussion covers the determination of the major data system parameters and gives examples of the most commonly occurring data collection problems. Procedures are also presented for determining the acceptability of the data produced, and guidelines are proposed for utilizing data to answer experimenters' questions.
Digital Filtering of Impact Data
Authors: Cain PJ
Published: December 2008

Idealized load signals were created to represent the failure of various types of materials under impact loading. The frequency content was investigated using Fourier transform methods. Several types of filtering approaches were applied to these signals. A numerical model of the impact process was used to generate data to study sources of noise in the impact process. Based on these investigations, a filter design was proposed and evaluated on examples of data from experiments. The conventional approaches to filter techniques may not be suitable for high rate data.
Testing, Simulation, and Interpretation of Materials Impact Characteristics
Authors: Jemian WA , Jang BZ , Chou JS
Published: December 2008

Research was initiated to measure the characteristics and properties of materials to support a valid simulation for general design purposes. Cushioning systems are used for personal protection in sports and transportation and for the safe transport of fragile materials. Design costs can be reduced by replacing prototype construction with simulation procedures.

Materials impact characteristics are in response to transient dynamic loading involving a sequence of structural processes during the period of contact. In most applications the engineering system responds in an overdamped configuration to eliminate oscillations. The cushioning component, however, is usually a viscoelastic, low-density substance with distinctive characteristics and properties. Cushioning is defined as the redirecting of motion under a controlled level of deceleration. The damping function is separate, being a dissipation of kinetic energy to terminate motion.

A variety of foamed plastics, including polypropylene, polystyrene, and polyurethane formulations were tested in the form of homogeneous blocks with dimensions of 3.8 by 3.8 by 2.5 cm (1.5 by 1.5 by 1.0 in.). Flat-surface impact was employed with drop heights ranging to 122 cm (48 in.). Voltage signals from an accelerometer in the impactor and a force cell below the specimen stage were recorded using a digital storage oscilloscope. These data were processed separately for analysis.

Specimen characterization also included measurement of density and stress relaxation and static testing at rates allowing effective specimen compliance. The objective of the experimental measurements was to determine the density, damping, and structural stiffness to provide the needed information for the deformation process in the governing differential equation Mü + C˙u + Ku = R where ü, , and u are the acceleration, velocity, and displacement in compression, respectively, and M, C, and K are the mass, damping, and structural stiffness properties of the materials in the test system.

Simulation was performed by finite element (FE) structural analysis developed in prior research. The FE program provided transient, dynamic analysis using nonlinear structural stiffness and damping. The FE model included the corresponding size, shape, and properties of the impactor, specimen, and stage in an appropriate manner. Simulation results were matched with measured responses to establish the validity of the simulation procedure.

Additional experimental drop tests showed pronounced differences between the characteristics of different materials. These observations and specific test procedures allowed conclusions to be drawn relative to the nature of the mechanical and structural responses at different stages of cushioning. These include separate effects of inertial stiffness, dynamic stiffness (due to damping), and structural stiffness occurring when motion is arrested.
Variable-Rate Impact Testing of Polymeric Materials—A Review
Authors: Driscoll SB
Published: December 2008

Instrumented impact testing has been discussed since the early 1970s but has still not been readily accepted and employed in characterizing polymeric materials systems. This paper explores this topic by reviewing some of the more important technical papers presented at various professional society meetings. The second part of this paper identifies areas of interest in research methodology, including testing parameters such as material composition, geometry, fabrication, loading history, and temperature.