bluuebunny/crossref_metadata_2025_split huggingface dataset:
Model for the Mass Transfer and Decay of Hydrogen Chloride in a Fire Scenario
Authors: Galloway FM , Hirschler MM 
Published: February 2009

It is now well established that hydrogen chloride is unusual among common fire gases in that it decays from the atmosphere. No model of hydrogen chloride transport and decay exists as yet, which has been formulated in such a way that it is generic enough to be used for scenarios different from the one in which the experiments were carried out, and can be incorporated into more comprehensive fire hazard models. The present paper introduces such a model. It deals with the influence of various surfaces [poly(methyl methacrylate) (PMMA), painted gypsum board, ceiling tile, cement block and Marinite], of surface to volume ratio and of humidity, on atmospheric hydrogen chloride concentration, both inside and outside the room of origin of the fire.
The present model incorporates generation of hydrogen chloride from poly(vinyl chloride), mass transfer to various wall locations, partition between the atmosphere and the surface, and a combination of diffusion and reaction inside the surface. The parameters in the model were fitted by using a non-linear (Marquardt) optimization procedure.
The model was corroborated using various experiments which involved the combustion of poly(vinyl chloride) in large- and small-scale scenarios.
It was found that, for a non-sorptive surface such as PMMA, the rate of mass transfer to the surface is much larger than the rates of the various reactions at the surface, in all cases. Such a surface, thus, allows much higher peak hydrogen chloride concentrations and much lower rates of decay than any of the sorptive surfaces investigated.
For sorptive surfaces and static systems the rate limiting process is the mass transfer to the surface. The activity of the various surfaces investigated was found to follow the order: ceiling tile &gt; cement &gt; Marinite ≥ painted gypsum board ≫ PMMA
The significance of this model is that it can predict hydrogen chloride decay in a real fire scenario. It is relevant to point out that normal construction surfaces are sorptive, and that hydrogen chloride decay will generally be quite fast in a fire, whereas it will be much slower in a small-scale toxicity test exposure chamber.
The Ladle Refining Process for Bearing-Quality Steels
Authors: Odar JA , Fecich DJ 
Published: February 2009

Bearing-quality steels that have been previously refined by the vacuum degas carbon deoxidation process for microcleanliness considerations are now able to achieve lower levels of oxygen and inclusion content by ladle refining. Through aluminum deoxidation in the presence of strong stirring energy, inclusions are removed by mechanical rather than chemical means. Such refining techniques are provided by ladle reheat capability, slag control, de-slagging, stirring, alloy and deoxidizer injection, and vacuum degassing, further enhanced with bottom pouring, shrouding, and casting.
Several ladle refining options were studied to evaluate the relative cleanliness levels that the processes were capable of producing. Superior levels of steel quality and chemistry control were achieved by these out-of-the furnace techniques in terms of microcleanliness as measured by the JK-worst field and SAM ratings, and of macrocleanliness as measured by magnetic particle inspection procedures of AMS 2301.
Chemically Induced Community Responses in a Compartmentalized Microcosm Assessed by Multidimensional State Space Transitions
Authors: de Zwart D , Langstraat H 
Published: February 2009

A test has been developed to assess the chemically induced disturbance produced by interactions between functionally different groups of organisms. Algae, daphnids, polyps, and decomposer organisms—representing adjacent trophic levels—were housed in separate containers. Water containing algae and nutrients was circulated through the compartments. In some experiments, according to a realistic scheme based on empirically derived knowledge of the needs of the individual populations, an interactive relationship was maintained between standing stock parameters and the circulation rate and between predation on daphnids and feeding by polyps. Since, for each compartment, input and output fluxes were experimentally determined, the rates of processes could be calculated. One of the major drawbacks of the small volume (14 L) of the microcosm was the necessity for nondestructive or micro methods of analysis.
In the experiments presented in this paper, only the standing stock parameters for the algae, daphnids, and polyps, and occasionally the pH, were measured with enough adequacy to construct a multivariate “normal operating range” (95% confidence interval) out of the rather long time series of preexpositional data. This “normal operating range” was used as a reference state for the changes after perturbation.
Perturbation of the model ecosystem with a toxic chemical (in this case, 2,4-dichloroaniline) was followed by a gradual displacement outside the normal operating range. All four systems tested showed a temporary or permanent shift in the three-dimensional state space outside the normal operating confinement within ten days after the addition of 0.010 mg L−1 of the toxicant, whereas the lowest “no-observed-toxic-effect level,” determined by semichronic tests on the susceptibility, individually, of populations of green algae, daphnids, and polyps, was slightly higher. (For Daphnia magna, this level was 0.032 mg L−1.)
Use of Freshwater Macroinvertebrate Microcosms in the Impact Evaluation of Toxic Wastes
Authors: Livingston RJ 
Published: February 2009

The author compared the impact of toxic waste sites on three streams in South Carolina and Florida. In addition to the field evaluations of macroinvertebrate distribution (as determined by artificial leaf-pack collectors), a series of acute (4-day) and chronic (30-day) leaf-pack bioassays were carried out with polluted water and leaf-pack microcosms taken from the related study sites. The comparison of laboratory and field data was carried out over a one to two-year period at quarterly intervals. These experiments were designed to evaluate and verify the use of microcosms in predicting field impact and to test for possible seasonality in the laboratory-field relationship.
Leaf-pack data from the field indicated that there was no impact in a South Carolina stream (Myers Creek) because the toxic wastes never entered the surface water system. The four-day leaf-pack bioassay was useful in confirming the lack of adverse effects in the field. Field gradients of macroinvertebrates were evident in Hogtown Creek, Florida (from the low dissolved oxygen and high levels of phenolic derivatives), and in the Little Dry Creek/Dry Creek system, Florida (from the low pH and high lead and aluminum). The acute leaf-pack tests in the Hogtown Creek system did not predict the field impact as well as the chronic tests, whereas both forms of testing in the Little Dry Creek/Dry Creek system were effective in the prediction of field impact. In both systems, the presence of pollution-resistant species complicated the direct extrapolation of bioassay results to field conditions. There was considerable variation in the responses of individual species to the laboratory conditions; however, species richness was a relatively robust laboratory indicator of impact in both streams. Variables that had some influence on the ability to predict field impact using bioassay tests included local features of the stream system, the type of toxic waste, the duration of laboratory exposure to the toxic agents, and the community index used for the comparison. In some instances, the period of sampling was a factor in the laboratory-field relationship. These test results indicate that calibration of the macroinvertebrate microcosm with field data is necessary if such tests are to be used to predict field impact of toxic wastes. Such microcosms, properly used, can be effective for extrapolation of laboratory results to complex field conditions.
The Need for International Cooperation Regarding Approvals
Authors: Hougaard M 
Published: February 2009

Research shows that chemical protective equipment should be permeation tested against the exact chemical it is expected to protect against. Because more than 10 000 different chemicals are used today, the amount of permeation testing is immense.
Public reaction to and the legal ramifications of inadequate protection are discussed. A negotiation model, including the four major interests to be fulfilled by an international approval or certification system, is established.
Standards and certification concepts are defined as well as the roles of the organizations involved. Due to the amount of testing, if a national approval or certification system for chemical protective clothing is created, then it should be designed with the prospect of becoming international at a later stage.
A data presentation form that can be implemented immediately by manufacturers of chemical protective equipment is proposed.
Evaluation of Fourteen Fabric Combinations, One Glove Material and Three Face Shield Materials to Molten Steel Impact
Authors: Forsberg K 
Published: February 2009

The heat resistance of fourteen fabric combinations, one glove material, and three face shield materials has been evaluated by controlled splashes of 1 kg of molten steel. The test procedure is described in ASTM Evaluating Heat Transfer through Materials Upon Contact with Molten Substances (F 955-85). Five- and forty-second calorimeter thermal responses were plotted. The heat resistance was determinated by measuring the temperature rise and calculating the maximum heat flux. The test materials were also visually examined.
The test materials were aluminized rayon; jacket/pant materials in wool, cotton, and wool/Cordelan; underwear materials in wool, cotton/modal, and Cordelan/polyester; Kevlar; and face shield materials in polysulfone polycarbonate and acetate.
The test results indicated &lt;1 cal/cm2/s of maximum heat flux in six of the fabric combinations and the three face shields.
The evaluation of the fabric combinations and face shield materials to molten steel impact was a part of the project named “Development of Protective Clothing Working at Continuous Casting.”
It was concluded that the proper combination of outer clothing and underwear clothing for the “8-h garment” can be a more comfortable substitute for the combination of aluminized clothing and outer clothing used today in front coats and flame-retardent clothing.
Approaches to Predicting the Cumulative Permeation of Chemicals Through Protective Clothing Polymers
Authors: Goydan R , Schwope AD , Reid RC , Krishnamurthy S , Wong K 
Published: February 2009

Approaches for predicting the permeation resistance of chemical protective clothing polymers were investigated and assessed for accuracy and applicability to the Premanufacture Notification (PMN) review process of the U.S. Environmental Protection Agency (EPA) Office of Toxic Substances (OTS). The approaches emphasize the prediction of cumulative permeation and include: (1) a predictive model based on Fickian diffusion theory and (2) test methods for directly assessing permeation resistance.
The predictive model is based on refinements of existing theoretical approaches for estimating diffusion coefficients and solubilities from the physical properties of the solute and polymer. Permeation model predictions were compared to well-documented permeation data from the literature. Examples of the model's range of applicability and its limitations are provided. Although the results of the permeation modeling approach are promising, direct testing is the most accurate approach to assess clothing performance for the variety and complexity of chemicals and chemical mixtures that are typical of PMN substances. Consequently, chemical resistance test methods were reviewed for accuracy and applicability. Test methods reviewed include permeation tests, degradation tests, liquid immersion weight change tests, and sorption/desorption methods. Based on this review, a hierarchy is proposed that ranks chemical resistance tests according to their ability to generate data needed to assess PMN clothing requirements.
Carbon-14 Tracers in Permeation Studies: Feasibility Demonstration
Authors: Ursin C , Drabaek I 
Published: February 2009

This paper deals with results from a feasibility study initiated by the U.S. Coast Guard under Contract DTCG39-85-R-80272 on Radioactive Tracers in Permeation Studies.
Permeation tests using 14C-labeled permeant chemicals have been performed according to ASTM Test Method for Resistance of Protective Clothing Materials to Permeation by Hazardous Liquid Chemicals (F 739-81). The method has included water as the collecting medium, discrete sampling with replenishment, and counting of the samples with liquid scintillation counting. Tests with Viton/chlorobutyl laminate on polyester support and acetone as permeant plus neoprene and nitrobenzene are reported. Due to a high sensitivity, breakthrough is seen in both cases in the first samples, that is, after 2 min for Viton/chlorobutyl laminate/acetone and after 2 s for neoprene/nitrobenzene. Steady-state permeation rate is achieved after 3.5 h at 0.49 mg/m2/s1, and 1 and 0.3 h at 5.93 mg/m2/s1 for the Viton/chlorobutyl laminate/acetone system and the neoprene/nitrobenzene system, respectively.
For the Viton/chlorobutyl laminate/acetone system, the propagation versus time of the permeant front inside the membrane has been visualized by autoradiography using a freezing technique and a cryomicrotome.
An autoradiographic calibration technique has been developed and applied giving the absolute concentration (mg/g) versus depth in microns from the exposed side of the membranes.
The tracer technique in combination with dry combustion has been applied to well-known decontamination procedures with the neoprene/nitrobenzene system. After thermal treatment, a residual amount of 0.08% nitrobenzene was found, implying a decontamination efficiency of 99.9%.
Testing the Quality of Breathable Textiles
Authors: Salz P 
Published: February 2009

New laboratory methods have been developed for the evaluation of the waterproofness and water vapor permeability of breathable rainwear. The waterproofness was measured using a dynamic shower tester than combines mechanical action and wicking effects, thus closely simulating actual wear conditions. It is shown that some microporous fabrics that have a high water entry pressure allow leakage when they are periodically compressed. Multiple-layer assemblies of water-repellent fabrics were also evaluated. The water vapor transmission of breathable fabrics in rain was determined using a heated cup method in combination with an artificial rain installation. The results indicate that vapor transport characteristics of fabrics are subject to change depending on the weather.
The new methods provide a means for selecting fabrics for high-performance rainwear.
Using Dipropyl Sulfide to Test the Leakage of Protective Clothing
Authors: Fang G , Dingmao H , Huaimin W 
Published: February 2009

Dipropyl sulfide is used as a leakage testing gas for either a carbon-containing permeable chemical protective suit or a permeation-resistant suit. It has the advantages of low toxicity, easiness of adsorption by activated carbon, relatively high vapor pressure, and commercial availability.
A sensitive Chloramide-Ester-Congo Red (CEC) indicator paper (cloth) was developed that can detect 0.014 mg/dm3 of dipropyl sulfide vapor by color change within 2 min.
Testing procedures are demonstrated that can evaluate the protective suit's airtightness.
Evaluation of Protective Clothing Materials Challenged by Petroleum and Synfuel Fluids
Authors: Gammage RB , Dreibelbis WG , Allen White D , Vo-Dinh T , Huguenard JD 
Published: February 2009

The permeation characteristics of eleven petroleum, coal, and shale oil hydrocarbon liquids through eight different types of glove were measured over 24 h. Two analytical techniques, photoionization and room-temperature phosphorescence of polynuclear aromatic compounds, were used to measure breakthrough times by volatile and low-volatility constituents, respectively. Serious drawbacks to the general use of these techniques for measuring steady-state rates of permeation were noted.
The lighter, smaller molecular-size constituents permeated faster than the larger, multi-ringed aromatic constituents. For the light hydrocarbon fuels, especially gasoline, there was preferential permeation by benzene and toluene. Nitrile was severely corroded after extended exposure to hydroxybenzene-containing coal-derived liquids. A general ranking, from worst to best, of the protection afforded by the different gloves was latex ≪ neoprene &lt; butyl rubber, polyvinyl chloride (PVC) &lt; nitrile &lt; Viton, Tyvek/Saranex 23, and polyvinyl alcohol (PVA). No breakthroughs within 24 h were observed with the latter three glove materials.
Decontamination of Chemical Protective Clothing Exhibiting Matrix Release
Authors: Berardinelli SP , Hall R 
Published: February 2009

This study was conducted to evaluate decontamination methods for a glove material/liquid chemical combination that, together, demonstrated matrix release. A glove material/liquid chemical combination was assumed to exhibit matrix release if the following two conditions were met: (1) the glove material, which was exposed to the challenge liquid chemical until equilibrium saturation was attained, slowly released the entrapped challenge chemical for at least 72 h after exposure; and (2) upon re-exposure to the challenge chemical, the glove material demonstrated a significantly different breakthrough time. A neoprene/n-butyl acetate (glove/liquid chemical) combination, meeting these conditions, was investigated in detail. Neoprene/p-xylene and nitrile/n-butyl acetate combinations were reviewed, but did not exhibit matrix release.
Three decontamination methods were tested: (1) air drying at 25°C, (2) 15-min manual detergent wash, and (3) elevated temperature washing-drying. For the neoprene/n-butyl acetate combination, both air drying and a single 15-min manual detergent wash were ineffective in cleaning the saturated matrix. Breakthrough time changes and measurement of the concentration of n-butyl acetate in the material demonstrated that the matrix was still saturated. However, elevated temperature washing and drying (45°C wash and 95°C drying) did remove the residual n-butyl acetate from the neoprene.
Development of a Comprehensive Approach to Chemical Protective Clothing Use
Authors: Mansdorf SZ 
Published: February 2009

Chemical protective clothing (CPC) is a “last line of defense.” As such, proper selection and use are essential to the safety and health of the wearer.
A comprehensive approach to CPC selection and use should include at least eight key elements. They are: (1) assessing the need; (2) determination of the level and type of chemical and physical protection required through a hazard assessment of the proposed task; (3) proper selection based on the hazard assessment; (4) lab and field validation of the effectiveness of the selection; (5) establishment of reuse and decontamination guidelines; (6) worker and supervisory training in the use and limitations of the selected equipment; (7) establishment of a routine inspection, maintenance, and repair program; and (8) development of a management audit scheme to assure all elements of the CPC selection process are being properly followed.
Chemical protective clothing can be an effective hazard control measure; however, the protection provided will only be as efficacious as the quality of the methodology or program utilized for its proper selection, use, and maintenance.
Kennedy Space Center Maintenance Program for Propellant Handlers Ensembles
Authors: Dudzinski DJ 
Published: February 2009

The Propellant Handlers Ensembles are utilized at the Kennedy Space Center to provide protection to personnel performing tasks in hostile environments related to launch activities, and represent state-of-the-art developments in protective clothing. Problems encountered in attaining a successful maintenance program have been overcome through utilization of available resources and the combined efforts of users, engineers, and maintenance technicians.
This paper provides an overview of the methods used at the Kennedy Space Center to maintain a sizable inventory of Propellant Handlers Ensembles. Discussion includes description of the maintenance facility, suit decontamination, leak testing, cleaning, visual inspection, and repair techniques.
Measuring the Integrity of Totally Encapsulating Chemical Protective Suits
Authors: Johnson JS , Stull JO 
Published: February 2009

The Lawrence Livermore National Laboratory's (LLNL) Hazards Control Department has recognized for some time that totally encapsulating chemical protective (TECP) suits must be tested to assure that they function properly with a high degree of reliability. Two general types of tests are necessary to properly evaluate a TECP suit: design qualification tests and field use tests. To develop these tests for the evaluation of TECP suit performance, LLNL is participating in a jointly funded project with the U.S. Coast Guard, the U.S. Occupational Safety and Health Administration, and the U.S. Fire Administration. Four tests have been developed to measure TECP suit performance: a quantitative test, a worst-case chemical exposure test, a pressure leakage test, and a chemical leak rate test.
A quantitative TECP suit test method using Freon 12 gas and an aerosol, polyethylene glycol molecular weight 400 (PEG 400), to measure the leakage of both test agents into the suit is being developed. This leak rate is expressed as a “protection factor” that is calculated by dividing the outside test agent concentration by the suit interior test agent concentration. A worst-case chemical exposure test has been demonstrated using the U.S. Coast Guard's Teflon-coated Nomex TECP suit in a hydrogen fluoride gas cloud.
Two types of field use tests have also been developed. The TECP pressure test measures the suit leak rate by inflating the suit to a prescribed pressure and monitoring pressure drop in the suit over time, ASTM Standard Practice for Pressure Testing of Gas Tight Totally Encapsulating Chemical Protective Suits (F 1052-87). The proposed chemical leak rate test consists of generating a known ammonia concentration in a test room, wearing the TECP suit into the room, and doing a series of prescribed light exercises. The interior of the suit is monitored for ammonia after the test subject exists the test room, and the protection factor is calculated in the same manner as described earlier in the Freon 12 test procedure.
By employing the four TECP suit tests in the various stages of suit development and field use, a high degree of safety can be assured.