bluuebunny/crossref_metadata_2025_split huggingface dataset:
Materials Selection: Object-Oriented Structures for Factoring Polymer Information
Authors: Demaid A , Ogden S , Zucker J 
Published: March 2009

This paper discusses the fundamental issues involved in creating a taxonomy of engineering polymers capable of being implemented in class-instance, object-oriented programming languages. It reports the authors' experience of creating this taxonomy in POISE, our object-oriented database management system implemented in Smalltalk-80™ [1]. Our account is centred on the issues involved in a strict factoring of the domain of polymers according to chemical composition, molecular scale and molecular arrangement, where these produce similar effects. Knowledge representation of materials information in our taxonomy is implicit and potentially far-reaching when rules of composition and scale are adhered to, rather than explicit and restricting when pragmatic groupings are created for particular purposes.
Knowledge representation of the relatively large scale micro-structures which create reinforced plastics pose particularly difficult issues which are discussed in detail. We find that the usual high-level, factoring of the materials domain into metals, ceramics, plastics and composites or into polymers and reinforced polymers is inappropriate for a taxonomy designed to represent plastics knowledge in a robust way independently of a user's particular purposes. This finding complements the authors' work [2] on the importance of separating perspectives for representing engineering design knowledge. A strict regime of independent perspectives is seen to be desirable at all levels of knowledge representation. This argues against the generality, or extensibility, of mixed taxonomies that are commonly seen to arise from a representation of materials information in a particular context, for a particular purpose.
POISE allows complex entities such as polypropylene, polyolefin, crystalline thermoplastic, and thermoplastic, which represent a line of direct ancestry in our taxonomy, to be stored and processed as largely independent computing objects. This accords nicely with the intuition that in deciding whether to make a washing-up bowl from polypropylene or polyethylene an engineer will have an idea of the generic properties of the two plastics and that this process is ill-served by a database model which searches through many individual grades of these polymers.
We comment on the principled support of independent browsing facilities which our taxonomy supports and argue for the nature and benefits of an object-oriented model of materials information which allows complex computing representations to evolve rather than to be designed, and which allows a representation of the structure of polymer knowledge to exist in a useful form independently of a program which provides particular services over the knowledge base.
The Importance of Carbon Monoxide in the Toxicity of Fire Atmospheres
Authors: Debanne SM , Hirschler MM , Nelson GL 
Published: March 2009

This paper addresses the issue of determining toxic fire hazard in a manner that is relevant to the large-scale fire scenarios that cause most lethalities, ventilation controlled flashover fires.
The work involves (a) a literature study of background information on the toxicity of carbon monoxide (CO) to humans, (b) two very extensive forensic studies (with 2 241 and 2 673 cases, respectively) on human lethality involving CO in fires and non-fires, (c) statistical analyses of the forensic data, to ensure full separation of variables, and (d) an analysis of the literature on the effects of different parameters in fire atmospheres and in small-scale tests.
This work addresses five issues essential to fire hazard assessment: (1) Relative role of toxicants other than CO in causing fire fatalities and critical carboxyhemoglobin (COHb) values representing lethality. (2) Differences in populations between fire victims and those dying in other CO-containing atmospheres. (3) Comparison of modern fire atmospheres, containing smoke from man-made materials, with traditional fire atmospheres. (4) CO yields in flashover fires and effects of fuel chemistry. (5) CO yields in small-scale toxicity tests and fuel effects.
The work has shown that: (1) The toxicity of fire atmospheres is determined almost exclusively by the amount of CO. The lethal CO threshold level depends on the physical condition of the victim, but COHb values &gt; 20% can produce lethality with no other apparent cause. (2) Fire and non-fire CO victim populations are very different: fire victims are much older or much younger and more infirm, and thus more sensitive to CO than those in nonfire exposures. (3) Replacing large amounts of natural and traditionally used materials by man-made materials has made no difference to fire atmosphere toxicity. (4) CO concentrations in large-scale flashover fire atmospheres are determined by oxygen availability and such variables, but are little affected by chemical composition of fuels. (6) Small-scale tests give excessively low CO yields so that they cannot be used to predict toxic fire hazard for ventilation controlled flashover fires, although post computational CO concentration corrections can make these tests useful as part of fire hazard assessment calculations.
Electrical Cable Fire Hazard Assessment with the Cone Calorimeter
Authors: Hirschler MM 
Published: March 2009

A series of full-scale cable tray fire tests have been done and the results have been expressed in terms of heat release (rate and amount), smoke release (rate and amount), mass loss and gas emissions, as well as the standard properties of flame spread and extent of charring. These tests were carried out in two different full-scale facilities.
The same cables have also been tested in the cone rate of heat release calorimeter, (ASTM Method for Heat and Visible Smoke Release Rates for Materials and Products Using an Oxygen Consumption Calorimeter, E 1354), in a horizontal orientation, and the same prop-erties (except for gas emissions) are measured. Moreover, the combustible materials which make up many of the cables have also been tested in both the cone calorimeter and the Ohio State University (OSU) rate of heat release calorimeter (ASTM Method for Heat and Visible Smoke Release Rates for Materials and Products, E 906).
The rate of heat release results of the cone calorimeter tests on cables were well correlated, linearly, with the results of the full-scale tests. This was particularly true when the cone was used at an incident flux of 20 kW/m2. A model has therefore been devised to predict full-scale cable tray results.
The amount of smoke obscuration resulting from all full-scale cable tests was heavily dependent on the extent of burning of the cables. Those cables that did not burn extensively and released very little smoke. Similarly, those cables that did not burn extensively released low amounts of combustion gases, notably CO and HCl.
As far as smoke release is concerned, total smoke released in the full-scale fires correlated very well with smoke factors measured in the small-scale cone calorimeter tests. The total smoke released in the small-scale tests, following complete sample combustion, was a much less reliable measure of full-scale smoke release than the smoke factor.
The two small-scale rate of heat release instruments correlated well with each other, on all properties, except for time to sustained burning.
Some fire properties of the cable jacket material alone, in the cone calorimeter at 20 kW/ m2, can be used to give a priori indication of likely cable full-scale fire performance in a certain scenario. The properties most appropriate for this purpose are the peak rate of heat release and the smoke factor. The OSU calorimeter was a somewhat less reliable small-scale predictor than the cone calorimeter, based on jacket material results only.
Fire tests with the cone calorimeter can thus be used for preliminary fire hazard assessmentof electrical cables when installed in vertical cable trays.
A Reliability Methodology Applied to Halon 1301 Extinguishing Systems in Computer Rooms
Authors: Steciak J , Zalosh RG 
Published: March 2009

This fault tree analysis of a total flooding Halon 1301 extinguishing system in a computer room illustrates a methodology developed to estimate the probability that vaporizing liquid suppression systems may fail to protect against fire or smoke damage. The methodology follows four steps: 1) specify a prototype system; 2) identify failure scenarios; 3) determine the probability of occurrence of the failure scenarios; and 4) perform uncertainty calculations.
The prototype used here is a total flooding Halon 1301 system installed in a computer room in 1977. Three fire scenarios are analyzed: (1) a fire of electrical origin inside an equipment cabinet; (2) a paper trash fire; and (3) smoke entering from a fire outside the room (this last scenario is a measure of the detection, control system, and smoke damper effectiveness).
The results show that, of the three scenarios, the halon system is most effective against the fire of electrical origin providing the electrical ignition source is de-energized before the halon supply is depleted. The results also show that the system provides reliable protection against smoke damage from a fire outside the room, but is less effective against the paper trash fire because of the reignition hazard if the supply is depleted. Other analyses performed include the effect of different inspection intervals, human intervention, and acceptance tests on overall system reliability.
Application of Fire and Explosion Risk Assessment to an LPG Bulk Storage Facility
Authors: Barry TF 
Published: March 2009

This paper contains an analytical examination of risk to human life beyond the boundaries of a hypothetical plant site, labeled the XYZ Plant, which stores and handles liquefied petroleum gas (LPG). The focus is the integration of available risk assessment research and techniques into a structured decision support tool. Procedures presented in this paper can be applied to a wide array of hazardous storage versus off-site risk exposure projects.
Quantitative risk assessment procedures are applied in determining fire and explosion effect zones and fatality probabilities in the area directly north of the XYZ Plant. The risk is assessed assuming that all four 113 562 L LPG tanks are updated with specified high reliability emergency shutdown systems and fire protection systems.
Event tree methodology is used in developing the fire and explosion scenarios which could result from the accidental release of LPG from containment.
Risk assessment tasks include the selection of significant LPG failure modes, calculation of release rates, and consequence modeling of human fatality effect zones. Boiling liquid expanding vapor explosion (BLEVE), flash fire radiant heat exposure, and explosion overpressures from unconfined vapor cloud explosions are modeled. Probability modeling is conducted by structuring event trees and assigning initiating event frequencies and conditional probabilities to the defined loss events.
Results are presented in an individual risk profile which depicts the probability of human death versus distance from the LPG storage tanks. The individual risk profile is suitable for use by the local Planning Commission as one source of information for making informed decisions concerning future development in the area north of the XYZ Plant.
A Fire Risk and Protection Cost Assessment Model for Highrise Apartment Buildings
Authors: Hadjisophocleous GV , Yung D 
Published: March 2009

This paper describes a stochastic system model that was developed to represent the dynamic interaction between human behavior and fire growth and spread in highrise apartment buildings. The effects of the smoke and fire spread are calculated in terms of two performance parameters: the expected risk-to-life (ERL) and the fire-cost expectation (FCE).
These performance parameters are used to assess the cost-effectiveness of fire safety and protection provisions in highrise apartment buildings. The system model can be used as a tool to assess whether alternative designs provide equivalent safety and whether these alternative designs are cost effective. As an example, the model is applied to a 28-storey apartment building where the cost-effectiveness of 9 different combinations of alarm and sprinkler systems is assessed.
Overview of ASTM E-7 Nondestructive Testing Standards
Authors: Borucki JS 
Published: March 2009

The American Society for Testing and Materials Committee E-7 has developed and implemented nondestructive testing standards for the NDT industry for well over 50 years. Today there are more than 125 ASTM NDT standards available covering all major nondestructive testing disciplines with several more under development. The work of Committee E-7 continues in the 1990s as we strive to respond to the ever-growing needs of the NDT industry to establish new standards and improve on existing documents.
This publication focuses on the realization that a myriad of NDT standards exist, that they originate in several organizations worldwide, and that there is a serious need for improved global standardization. It is a goal of Committee E-7 to gain a better understanding of worldwide NDT standards needs and to establish better liaison and cooperation with these other organizations so that we can better respond to the needs.
Status and Future Directions for Acoustic Emission Standards
Authors: Jolly WD 
Published: March 2009

Acoustic emission is still a dynamic technology after some 25 years of continuing development. Standards are developed as new applications are proven, and the need for new standards is pressed by both suppliers and users of acoustic emission services. At the present time, ASTM has twelve acoustic emission standards in Volume 03.03 of the Annual Book of ASTM Standards and five in development; the American Society of Mechanical Engineers Section V has two acoustic emission standards; the Society for the Plastics Industry has one; and the American Society for Nondestructive Testing now offers testing for certification of acoustic emission practitioners.
Acoustic emission standards are typically written by representatives of the users, suppliers of services and instruments, and researchers. This mix assures that standards will satisfy the needs of the community and incorporate new technology. Some acoustic emission standards anticipated for the future are offshore testing, underwater surveillance, and aircraft structural-integrity assessment.
Nondestructive Testing/Examination in the Construction Industry
Authors: Plumstead WC 
Published: March 2009

Construction quality standards are dictated by engineering design or regulatory requirements. The type of service determines the specific nondestructive examination (NDE) requirements. Petrochemical, power, and high-pressure service are typical areas of construction that use codes and standards to specify quality requirements.
Most of the construction industry employs NDE subcontractors to perform required nondestructive examinations. Some companies use approved vendor lists for the selection of subcontractors. The evaluation of subcontractor programs and personnel is a cost to construction. Where it is not required, evaluations are often eliminated to reduce costs to construction.
A better system is needed to assure more consistent performance of nondestructive examinations. The present cost to industry resulting from substandard performance is excessive. Prequalification of NDE subcontractors programs and personnel will reduce the costs to construction that are associated with poor performance.
Increased utilization of ASTM Practice for Determining the Qualification of Nondestructive Testing Agencies (E 543) will improve the general qualifications of the nondestructive testing agencies and result in improved performance.
Applications of Materials Wear Testing to Solids Transport via Centrifugal Slurry Pumps
Authors: Pagalthivarthi KV , Helmly FW 
Published: March 2009

Erosion wear of centrifugal slurry pumps is traditionally attributed to two different mechanisms, particle impact and scouring, which occurs as a result of a sliding bed of particles scratching against the wear surface. The impact and sliding wear coefficients (energy consumed per unit volume of material removed) are usually determined by separately simulating the two processes of wear in laboratory test equipment.
Although such simulations yield acceptable relative wear indexes for ranking wear resistance of materials, they fail to yield reasonable absolute values of wear coefficients when compared with actual measurements of wear on a pump. Possible reasons for this lack of agreement are proposed, and an alternative approach is presented to determine the absolute wear coefficients. This approach involves the finite element analysis of two-phase flow within the pump casing coupled with wear measurements on an actual pump casing. Test results for the simulated laboratory tests and the actual pump test are presented and discussed.
The Pi Test for Evaluating Bioavailability of Phosphorus
Authors: Menon RG 
Published: March 2009

The Pi test is an innovative approach for evaluating the bioavailability of phosphorus (P) in soils. The test makes use of paper strips impregnated with iron oxides as a sink for P mobilized in a soil solution. The amount of P extracted by the strip was increased with increased surface area of the strip and increased time of contact between the iron oxide on the strip and phosphate ions in the soil solution. From soils the amount of P extracted increased with shaking time up to 8 h shaking. Over 8 h shaking, there was little increase in the amount of P extracted. Phosphorus extracted by the strips represents solution plus labile P that is mobilized. Soil : solution ratio had little effect on sorption of P by the Pi strips. Based on these, paper strips with 40 cm2 surface area and 16 h shaking time were chosen for further study.
The Pi test is insensitive to the type of soil. Significant amounts of P can be extracted by the filter paper strips from soils with low to high pH and the P extracted can predict yield and P uptake well at both low and high pH. Phosphorus extracted by the strips correlates well with P extracted by the Bray I, Mehlich I, and Olsen tests in acid soil and with Olsen P in alkaline and calcareous soils. The Pi test has a potential use in monitoring P concentrations in aquatic ecosystems, with preliminary studies showing that the test can reliably estimate dissolved P in water.
Hydraulic Conductivity of Vertical Cutoff Walls
Authors: Evans JC 
Published: March 2009

Vertical cutoff walls have been used to control the movement of contaminants and contaminated groundwater since the remediation of contaminated sites began. There are, however, significant hydraulic conductivity differences between soil-bentonite, cement-bentonite, plastic concrete, and in situ mixed cutoff walls. The results of laboratory and field studies were assessed to show the influence of material properties, confining stress, permeameter type, water table position, and state of stress, on the hydraulic conductivity of vertical cutoffs.
The results of these studies show the range of hydraulic conductivity expected for each of the cutoff wall types. Increasing confining stress markedly decreases the hydraulic conductivity of soil-bentonite and has a measurable but reduced impact on stronger backfill materials. Studies on soil-bentonite cutoff walls show that the stress at depth is less than predicted using the effective weight of the overlying materials. This reduction in stress is a result of soil-bentonite materials “hanging-up” on the side walls of the trench. Thus, applying the effective stress calculated from the effective weight of the overlying backfill overestimates the stress to be used in the laboratory tests and results in unconservative measures of hydraulic conductivity. Field data also reveals that, with time, the hydraulic conductivity of soil-bentonite above the water table may increase substantially. Further, the hydraulic conductivity does not significantly decrease upon re-saturation.
Slug Tests for Determining Hydraulic Conductivity of Natural Geologic Deposits
Authors: Herzog BL 
Published: March 2009

This paper reviews four methods for analyzing slug test data to determine hydraulic conductivity and examines the effects of slug size on slug test results. Data from more than 100 slug tests, including tests for low permeability (glacial tills and fractured rock) deposits, coarse-grained (sand) deposits, and simulated tests were analyzed. Analysis of the data showed that all four analytical methods can produce similar values of hydraulic conductivity for low permeability deposits. Values determined for coarser deposits were highly dependent on method; values commonly spanned up to two orders of magnitude. The method of Cooper et al. (1967) generally produced the highest values, followed by the methods of Bouwer and Rice (1976), Hvorslev (1951), and Nguyen and Pinder (1984).
For sandy materials, tests were repeated on each well using several different slug sizes, ranging from 0.5 to 6 meters. Several of the glacial till materials were tested using two different slug sizes. Calculated hydraulic conductivity values were independent of these slug sizes.
Volume-Controlled Hydrologic Property Measurements in Triaxial Systems
Authors: Olsen HW , Willden AT , Kiusalaas NJ , Nelson KR , Poeter EP 
Published: March 2009

New capabilities for hydrologic property measurements in triaxial systems include: (1) volume-controlled and simultaneous measurements of hydraulic conductivity and one-dimensional consolidation (or specific storage) of a saturated test specimen; and (2) volume-controlled measurements of hydraulic conductivity, matric potential, and the variation of these properties with the moisture content of an unsaturated test specimen.
Data on saturated kaolinite demonstrate simultaneous hydraulic-conductivity and one-dimensional consolidation tests with continuous monitoring of both vertical and horizontal effective stresses. Data on well-graded silty sand demonstrate the feasibility of concurrent constant-flow hydraulic conductivity and matric potential measurements, and the variation of these properties with moisture content, for undisturbed and unsaturated specimens mounted in triaxial cells. Refinements needed to realize the full potential of these capabilities include a more rigid triaxial cell to minimize compliance, and an improved technique for measuring hydraulic-head differences within an unsaturated test specimen.
A Model for Primary Creep of 63Sn-37Pb Solder
Authors: Schroeder SA , Morris WL , Mitchell MR , James MR 
Published: March 2009

A micromechanical model of transient and steady-state creep as it applies to near eutectic Sn-Pb solder is presented. The material is described as a two-phase system having individual material properties, coupled by long-range internal stresses. The constitutive equations permit primary creep and the transition to steady state to be simulated by a numerical analysis in which the global mechanical response is dependent on the local stress state.
The creep equations are calibrated through a series of shear strain measurements of thinwalled tubular solder specimens. Comparisons to predictions include cyclic shear straincontrolled experiments, creep relaxation, and combination ramp-hold shear strain and stress control environments. Application to finite element analysis of surface mount interconnects is described.