bluuebunny/crossref_metadata_2025 huggingface dataset:
Perspectives on Opportunities Toward a Hazard-Free Bioprocessing Environment
Authors: Elliott LJ , Halperin WE , Landrigan PJ
Published: March 2009

Practical research and commercial applications of biotechnologies are expanding rapidly. The increasing utilization of biotechnology is evident in the areas of clinical research, general medicine, agriculture, chemical synthesis, and waste disposal, to name only a few. In an effort to identify potential occupational health hazards during the early stages of this development, the National Institute for Occupational Safety and Health conducted industrial hygiene surveys at six companies involved in research and development of recombinant DNA (rDNA) techniques applicable to fermentation processes. During each visit potential worker exposures, engineering controls, work practices, and medical surveillance programs were assessed. Varying degrees of proficiency and sophistication were noted in all of the assessed areas. Three companies new to the field (less than ten years old) of industrial fermentation were less sophisticated in their approach to issues involving occupational safety and health than were companies with years of experience (20, 25, and 106 years) in such operations. The three less experienced companies had no operational protocols, conducted limited (if any) environmental monitoring for chemical and microbial hazards, did not conduct preventive maintenance, and had very limited medical surveillance programs. Two of these companies had not conducted any environmental monitoring of the fermentation or product extraction processes. Recommendations were made in the areas of preventive maintenance, environmental monitoring, medical surveillance, and improved containment during fermenter inoculation.
Accepting Risk: Responsibility Versus Liability
Authors: James AN , Papermaster GE
Published: March 2009

Biotechnology has become a growth industry; recent advances in technology have enabled the industry to develop new products at an increasingly rapid rate. Although many traditional laboratory techniques are employed by manufacturers of biotechnology products, new techniques are also being developed that are more appropriate or more specific to the new technologies. Similarly, although many of the risks and potential liabilities associated with biotechnology laboratories are the same as those associated with the operation of conventional laboratories, bioprocessing presents unique risks and liabilities of its own. The paper provides a brief overview of the traditional bases of legal liability that most likely will be applied to biotechnology producers in the event injury or illness results from biotechnology products or production methods. The paper also discusses allocation of losses resulting from such liability and suggests ways to minimize the legal risks associated with bioprocessing technology. The bases of legal liability discussed include violation of statutes or regulations, negligence, strict liability, products liability, and workers' compensation. In discussing allocation of loss, the paper touches briefly on the need to promote the availability of appropriate insurance coverage. In discussing ways to minimize legal risks, the paper suggests specific courses of action, including compliance with regulatory and statutory requirements and appropriate community standards; voluntary initiation of risk avoidance and risk management programs; careful education of laboratory personnel in the use of appropriate safety procedures; education of consumers as to potential hazards and safe methods of use; documentation of employee participation in educational programs; health monitoring programs for employees; and continual reassessment of safety, compliance, and educational programs. Finally, the paper points out the need for international cooperation on the development of standards of safety and liability in the biotechnology industry.
Design Criteria for Safety in the Isolation and Purification of Antibiotics and Biologically Active Compounds
Authors: Paul EL
Published: March 2009

A summary is presented of safety-related design considerations and practices in the isolation and purification of antibiotics and other biologically active compounds from fermentation broths, as practiced by Merck & Co., Inc., in current production operations.

Profiles of physical activity are established on process streams, isolated intermediates, and the final bulk active compound. Design criteria for worker protection are developed based on these profiles.
Public Perception of Biotechnology: Green Revolution or Green Monster?
Authors: Goldburg RJ , Denison RA
Published: March 2009

The public's perception of risk from biotechnology is colored by several factors: experience with the unforeseen consequences of other technologies, the perceived benefits of biotechnology, and the degree of confidence placed in society's ability to mitigate risks. Through analogies to debates over hazardous waste disposal, the authors discuss how public participation in oversight, public access to information, and industry acceptance of regulation can foster public acceptance of biotechnology.
Community Awareness: Cooperation or Confrontation
Authors: Hyer WC
Published: March 2009

A current, well-thought-out community awareness program should be part of the management plan of every bioprocessing facility.

The enactment of Title III, “Emergency Planning and Community Right-To-Know,” of the federal Superfund Amendment and Reauthorization Act of 1986 (SARA) indicates a fundamental shift towards more involvement on the part of local citizens with manufacturing facilities which they believe might impact upon their safety and health.

This paper discusses how public expectations of industry have been shifting over the past four decades, points out trends which will lead to a greater importance of community awareness, delineates five different situations in which community awareness plays a major role, and offers suggestions for developing an effective community awareness program.
Facing Frankenstein: The Importance of Public Participation
Authors: Barnes AJ
Published: March 2009

As the story of Frankenstein showed almost two centuries ago, the public will be frightened and uncooperative if they do not understand the nature of scientific experiments that take place in their communities. Thus, it is extremely important to the future success of the biotechnology industry that both government and industry be responsive to public concerns about biotechnological testing. First, we must do everything in our power to ensure that the release of new organisms into the environment poses no threat to human health or natural ecosystems. And, second, we must take pains to alleviate public concerns about the risks associated with biotechnology, whether those concerns are well-founded or not. The achievement of both these ends requires the involvement of a technically capable, publicly credible regulatory agency.
Township Review of a New Bioprocessing Facility in Henrietta, New York
Authors: Breese JR
Published: March 2009

This paper describes the procedure observed during the township review of a new bioprocessing facility in Henrietta, New York. The paper also makes recommendations about how such a process should be carried out.
Building Deck Waterproofing from the Point of the Specifier's “Pencil”
Authors: Racusin RG
Published: March 2009

Basic concepts of building deck waterproofing stem from the need for economic use of limited land resources, from the advantage of thermal efficiency inherent with underground structures, and from esthetic considerations in architectural design. Plaza or terrace construction is simply a roof uniquely designed to accommodate other uses—pedestrian promenades, recreational and entertainment functions, and exhibition or parking areas—over occupied space. The most frequent problem in these types of construction is the failure to meet the fundamental need to keep water from leaking into the space below.

This paper addresses only the specification of quality and technical aspects of the design for the installation of waterproofing systems for horizontal applications. The specifier's selection of the waterproofing membrane depends on the type of substrate and on the nature of anticipated overlying components including membrane protection, insulation, drainage provisions, and wear surface, and on ambient climatic conditions and geographic location The wear surface can be monolithic or unitized.

The specifier should include requirements to protect components prior to installation and to prevent damage to the completed waterproofing membrane and overlying components.

Preconstruction quality assurance should include materials manufacturers and their applicators coordinating the surface treatment of substrate construction in order to assure compatibility of the substrate with the waterproofing membrane, and certifying the components and materials to be used. Contractor quality control should be specified to include continuous inspection of the application procedures and documentation of the installation.

The specifications must be coordinated and complementary with the drawings and details to avoid ambiguity, vagueness, and contradiction. The selected system of waterproofing membrane and related components should dictate the appropriate type of specification.

The histories of several projects will illustrate aspects of specifying building deck water-proofing.

Sources of nonpropnetary information for the design and installation of waterproofing systems include ASTM standards and the publications of trade organizations for architects, engineers, specifiers, applicators, and manufacturers. Components for the waterproofing system can be specified by use of generic standards or proprietary identifications.
Laboratory Evaluation of Different Methods for Adhering SBS-Modified Bituminous Roofing and Waterproofing Membranes
Authors: Berggren MA
Published: March 2009

Adhering SBS-modified asphalt roll roofing membranes with hot asphalt, using a propane torch to weld the SBS membrane to its substrate, and attachment of the SBS membrane with solvent-based bituminous adhesives are some of the major application techniques practiced successfully in the roofing industry. Integrity of the overlapping regions of placed membranes is of great concern, as this is seen as the most vulnerable route for moisture migration in a constructed membrane. The objective of this paper is to investigate and discuss the impact of each mode of application on the ability of the constructed SBS membrane overlap to provide adequate waterproofing and membrane lap strength. Results indicate that the energy to fail well-constructed laps in shear, regardless of mode of manufacture, approaches that of the energy to fail the individual membranes being adjoined. Cyclic fatigue results indicate that repeated load-bearing capability at 0°F (-17.8°C) without loss of waterproofing is possible for the three types of application methods. GPC shows that the torching process can be controlled to minimize SBS degradation. The results of all testing are dependent on application variables for each mode of manufacture. An understanding of the limitations to, as well as the requirements for, obtaining satisfactory performance has been developed.
Test Methods Used in ASTM Specifications for Liquid-Applied Elastomeric Membranes for Waterproofing Concrete
Authors: Evans RM
Published: March 2009

There are two types of waterproofing membranes, each designed to meet the special problems of concrete. The tests required by the two ASTM specifications for membranes—C 836 with a separate wearing course and C 957 with an integral wearing course—reflect the real life requirements of concrete surfaces.

Because concrete shrinks when weak, it tends to crack. Both specifications have tests to measure the ability to bridge cracks that open after the floor is laid and coated. Because concrete is very alkaline, both tests require tests of adhesion to concrete after water immersion. These same tests reflect the ability to penetrate and strengthen the powdery surface of the concrete.

A major application of waterproofings with an integral wearing course is the decks of parking garages. For this usage, tests of abrasion resistance, water and chemical resistance, and weather resistance are included in ASTM C 957.

This paper describes and critiques the rationale for these tests.
Seawater Corrosivity Around the World: Results from Three Years of Testing
Authors: Kirk WW , Pikul SJ
Published: March 2009

A world-wide test program was undertaken by Task Group G 1.09.02.03 to assess the relative corrosivity of seawater at 14 test sites. Aluminum alloy A95086, copper-nickel alloy C70600, and carbon steel alloy KOI501 specimens were prepared at one location, shipped to the various sites, and returned to the original site for final evaluations. Results obtained through three years of testing indicate that average corrosion behavior was generally within limits of previously published results. Individual site characteristics have been identified, however, that can have a profound effect on test results. Even when the ASTM standard test method was prescribed, variations affecting corrosion results became evident. In reality there is no natural seawater environment, as identified to date, in which to test materials. The final five year results are yet to be collected, but the cooperation of all program participants has contributed much toward accomplishment of the objectives. Still, more frequent and broader monitoring of sea-water variables at the exposure sites would assist in interpreting corrosion results.
Evaluating Corrosion Control in Water Distribution Systems at U.S. Army Bases
Authors: Temkar PM , Scholze RJ , Maloney SW , Neff CH
Published: March 2009

The U.S. Army Construction Engineering Research Laboratory (USA-CERL)has employed an apparatus known as the Pipe Loop System (CERL-PLS) to evaluate corrosion and corrosion control programs in distribution water systems The apparatus uses multiple corrosion specimens of distribution system materials in direct contact with water under conditions simulating typical operation At two U S Army water treatment plants, the CERL-PLS was used to monitor corrosion of mild steel and galvanized steel piping materials in the distribution system and determine the effect of a corrosion inhibitor on the long-term corrosion rates At another Army installation, the effects of various water treatment options were studied for reducing lead dissolution from plumbing system materials The data presented demonstrate the successful application of a pipe loop system for optimization of water treatment for corrosion control and hence to meet drinking water quality standards.
A Set of Standard Definitions for Laser Damage Parameters and Procedures
Authors: Arenberg JW
Published: March 2009

It is an essential aspect of science, technology and commerce to be able to communicate in a common language of units, procedure and phenomenology. Presently, there exist no such standards for the field of damage testing, leading to the present problems in scientific communication, comparison of test results and commercial activities. A necessary precursor to the standardization and proper cataloging of laser damage test data is a common nomenclature. There are many cases where parameters, phenomenology and test results are denoted by identical names. Moreover, there are cases where a single idea is known by multiple labels. This lack of standardization in the definitions and nomenclature leads to difficult, tedious and frequently unfruitful literature searches. This paper is intended to be the first step in the standardization of the field of laser induced damage by reviewing the literature and assigning in one review paper, a set of exclusive definitions or labels to the various definitions of damage, threshold determination, spot size and pulse width. In making these assignments, a vehicle is provided for the necessary seminal discussions leading to eventual adoption of accepted standards of procedure and definition for laser damage testing.
Damage Measurements on Optical Materials for Use in High-Peak-Power Lasers
Authors: Rainer F , Brusasco RM , Campbell JH , De Marco FP , Gonzales RP , Kozlowski MR , Milanovich FP , Morgan AJ , Scrivener MS , Staggs MC , Thomas IM , Velsko SP , Wolfe CR
Published: March 2009

Recently, we have expanded our efforts to develop state-of-the-art optical components for use in large-scale, high-peak-power, solid state lasers. Laser-induced damage to many of these components sets critical constraints on construction costs and limits the peak powers attainable in current and proposed devices. Increasing the damage threshold whenever possible by improving materials fabrication technology is therefore the ultimate goal of our work. The optical components and technological developments we are investigating are: Highly reflective mirrors • Kilo-layer coatings fabricated by high-temperature, plasma chemical vapor deposition (PCVD) • Laser conditioned physical-vapor-deposition (PVD) coatings • Multi-layer sol-gel coatings Anti-reflective coatings • Single layer sol-gel coatings deposited on substrates and non-linear crystals Non-linear crystals • High purity KDP, LAP and related frequency conversion crystals Substrates and laser hosts • High threshold surface preparation techniques • High threshold bulk materials Polarizers • Advanced PVD multi-layer coatings

Our research has resulted in an extensive database of laser-damage measurements. We present summaries of these measurements with particular emphasis on those taken at 1064 nm and 355 nm.
Prediction of Laser Induced Damage by Comparison of Laser Fluence Profile to Damage Spot Radius
Authors: Goedert R , Whittaker T , Templeton D
Published: March 2009

In this method, the laser induced damage threshold for a material is obtained by determining the fluence within the damaging beam at a radial distance equal to the radius of the damage spot. The energy profile of the laser pulse is determined by translating a slit across the beam and reading the energy passing through the slit with position. The laser profile is then quantified into fluence squares of area 400um2 in a two dimensional fluence grid. The radius of the damage site is then applied to the fluence grid, indicating the fluence square that corresponds to the edge of damage and it is this value that is the predicted damage threshold.
The Effect of Subsurface Defects on “Incipient” (Below Threshold) Laser Damage Nucleation in Fused Silica Optical Flats
Authors: Magee TJ , Leung CS , Orazio FD , Boyer JD , Mauro BR , Sanders VE
Published: March 2009

The development of subsurface defects in optical components has been extensively investigated by the authors and others over the past few years. Investigation of optical components using nondestructive photon backscattering (PBSTM), delineation etch/optical microscopy and charge decoration/delineation techniques has shown laterally variable spatial distributions of subsurface defects in the form of lineated remnant polishing traces, voids, and microscopic impurity clusters introduced during the surface finishing process. In this paper, we report on the correlation between nondestructive PBSTM mapping and delineation etch/optical microscopy techniques for detection of subsurface defects, as well as the effect of subsurface defects on the initiation of microscopic or “incipient” laser damage (λ= 248 nm) at levels below the point of macroscopic or catastrophic failure observed at the surface. The detection of laser induced microscopic cracking on nucleation sites within nondestructively identified areas provides additional insight into the progressive development of failure sites in distributed subsurface regions of low RMS, optically finished surfaces.
1-on-1 And n-on-1 Laser Strength of Binder Aided ZrO2 and ZrO2-SiO2 Reflective Sol-Gel Coatings
Authors: Floch HG , Priotton JJ
Published: March 2009

In continuation to our search program on laser-damage resistant coatings and in synergy with the Lawrence Livermore National Laboratory, we have prepared porous single layer coatings of ZrO2 on fused silica and BK-7 substrates from suitable aqueous colloidal suspensions of crystalline zirconia at room temperature. By adding judiciously a soluble inorganic binder to the suspension prior to application, it has been possible to increase substantially both the coating refractive index and the abrasion-resistance. The optimum binder concentration was about 30 % and at this level the optical properties and laser damage threshold of the zirconia coating were satisfactory. Multilayer high reflectivity dielectric coatings were also elaborated by laying down quaterwave-thick, alternating coats of this binder-aided zirconia with silica, also prepared from colloidal suspension. To achieve 99 % reflectivity, 17–19 layers were required. Single shot (1-on-1), laser damage tests at 1064-nm wavelength with a pulse length of 3-ns were carried out on both the single layer and multilayer systems. The thresholds averaged 8.6 and 8.2 J/cm2 respectively. With a laserannealing post-treatment, n-on-1 threshold values were higher than the 1-on-1 figures by a factor of about 1.5.
UV Seeding of IR Laser Induced Damage
Authors: Kerr NC , Clark SE , Emmony DC
Published: March 2009

The values of the laser induced surface damage thresholds for samples of silicon, fused quartz and soda lime glass at both 0.248μm (UV) and 10.6μm (IR) are presented. Experiments are then described where laser damage is induced using crossed UV-IR beams, with varying time delays imposed between the arrivals of the two laser pulses at the sample surface. The results of these crossed beam experiments are then discussed. Order of magnitude reductions in the IR damage thresholds of silicon and glass are observed when the beams are crossed, no such reduction is observed for quartz. Further, only in the case of glass samples is a reduction in the UV damage threshold seen when the beams are crossed. The reduction in IR threshold on silicon has been seen with delays between the laser pulses of up to 100ns. The reduction in IR threshold for glass was seen for delays up to 1.2ms. These results lead to a discussion of the role of so-called seed electrons in the damage process and the mechanisms operative at the different wavelengths.
Characterization of Lap Seam Strength for In-Place and Laboratory Prepared EFDM Roof Membranes
Authors: Hodges CP
Published: March 2009

A series of T-Peel lap seam adhesion tests were conducted on various EPDM roof membrane samples in order to characterize the typical expected seam strength in laboratory prepared samples, and in samples taken from new and in-service roofs. The program included constructing lap seams in the laboratory using four commercially available EPDM roof membranes and their proprietary adhesives and seaming techniques. In addition, two sets of seams were made and tested in the laboratory without the benefit of cleaning the splice area of the rubber. T-peel testing was also conducted on samples taken from two roofs that were approximately 6 months and 5 years in age. Three other sets of contractor prepared field seams were obtained during on-site roof construction and tested in T-peel. The objective of the study was to provide some reference data relative to seam strength developed in the laboratory versus that which is typically achieved in the field.
Evaluating Polymeric Roofing Membranes for Linear Dimensional Stability
Authors: Hogan LD
Published: March 2009

Currently available polymeric roofing membranes are ordinarily evaluated in a battery of tests that are hopefully indicators of in-situ performance. Field performance of some products has suggested that dimensional stability may be important among these. The test for such a property (ASTM D-1204) is a hot air bath environment for measured membrane samples. Presently, test environments are selected by manufacturers and range widely in the market. To promote congruency in testing/reporting, a scale is proposed for future testing within categories defined by generic polymer type.
Polyvinyl Chloride (PVC) Roofing: Preliminary Field Test Results
Authors: Foltz S , Bailey DM
Published: March 2009

Polyvinyl chloride (PVC) single-ply roofing systems have been installed at three U.S. military facilities for a ten year evaluation. This paper reports preliminary results through the first six years of testing. The test is part of long-term research by the U.S. Army Construction Engineering Research Laboratory (USA CERL) to identify alternatives to conventional built-up roofing for military construction and reroofing.

Membrane samples were taken periodically based on a schedule of every six months for the first two years and annually during the next four years. Laboratory testing was performed by the U. S. Bureau of Reclamation using American Society for Testing and Materials (ASTM) methods in most cases. A total of ten tests measuring mechanical and physical properties of the membranes and the seams were performed on each set of samples. Four other tests were done on a limited basis.
Photovoltaic Single-Ply Roofing Membranes
Authors: Laaly HO
Published: March 2009

The past twenty years is considered to be a landmark and revolutionary advancement period for the progress and recognition of various classes of Single-Ply Roofing Membranes in Canada and the United States. During the same two decades, parallel and independently tremendous efforts and billions of dollars were allocated to generate electricity from solar radiation by advancing the level of understanding and implementation of photovoltaic science and technology. Prohibitively expensive, in 1969, the dream of landing on the moon and returning to Earth became a reality by combined efforts of the U.S. scientific community. The use of photovoltaic semiconductors on glass panels was a key factor for the success of this monumental project.

Seventeen years later in 1986, the author succeeded in bringing these two technologies together. The photovoltaic single-ply roofing membrane is a product which combines the usefulness and universal utilization of both science and technologies. This patented procedure, the basic research and development of its components, and the self sufficiency of the electrical energy generated is discussed. The testing and application standards proposed for this class of revolutionary, flexible and bi-functional roofing membranes, examples of their potentials for mass production and applications are also provided.
Wind Test Methodology for Loose-Laid Roof Elements and Components
Authors: Pardo JE
Published: March 2009

This report concerns an investigation into the wind performance limits of loose-laid roof elements, as exemplified by membranes, pavers and other components of ballasted single-ply roofing systems. On the basis of comparisons between small scale model tests in Atmospheric Boundary Layer (ABL) wind tunnels and full scale prototype tests in aeronautical wind tunnels, a test method is developed and a semi-empirical analysis procedure is presented to account for the effects of air turbulence upon the limit windspeeds observed.
Structural Glazing from a Curtain Wall Designer's Perspective
Authors: Jacob LS , Johanson B
Published: March 2009

This paper endeavours to discuss the various issues that have to be considered by the curtain wall designer. Emphasis has been placed on the relativity and impact of new technology in the use of glass, sealants and other associated materials relative to the function and performance of the curtain wall. The need for acceptance and implementation of the current knowledge and technology is clearly demonstrated. The difference in the level of technology between the Researcher and the Practitioner is clearly identified and widening, specifically in relation to structural silicone design criteria.
Sealant Stresses in Tension and Shear
Authors: Shisler FW , Klosowski JM
Published: March 2009

This paper addresses the question, “Are the stress vs strain or modulus characteristics of various generic sealants the same in shear as they are in tension?”

The ASTM tests and Federal Specifications for sealants address the joint movement ability of sealants when they are stressed in tension and compression. Nowhere does a test or specification relate to the movement ability in shear directions. Many joints are made of dissimilar materials so that with temperature changes these materials change dimension by differing amounts. Also, some joints are stressed as one substrate moves in or out of the plane of the wall or floor. The above mentioned cases are examples of shear movement. The authors stressed a variety of different generic sealants in the tension mode as well as the two shear modes (longitudinal and transverse). They show the relationship of the tension movement to the shear movements for sealants from each of the generic types.
Experimental Work Carried out in Support of the Development of an International Standard on Movement Capability of Sealants
Authors: Wolf AT
Published: March 2009

The paper compares the results of different lab tests, suggested during the development of an ISO standard on sealant durability, with those obtained from outdoor weathering under mechanical strain. The comparison shows that the 70 C compression test, as included in ASTM C-719, is helpful in identifying sealants, which fail due to high compression set. The heat compression test, however, does not rule out sealants that tend to post-cure or embrittle upon ageing. The best correlation between lab tests and outdoor weathering is obtained, if the sealants are allowed to fully cure prior to lab testing.
The Influence of Heat Ageing on One-Part Construction Silicone Sealants
Authors: Stoegbauer H , Wolf AT
Published: March 2009

The paper studies the effects of heat ageing on the elongation at break and tensile strength of 10 commercially available, standard construction silicone sealants, based on acetoxy, alkoxy, aminoxy and oxime cure. Mechanical properties are measured on ISO 8339 tensile test joints after exposure to 100, 150, 180 and 200 °C as well as room temperature (as a control) over a period of 1, 3 and 6 months. The study shows that the heat stability of those one-part silicone sealants investigated is influenced mainly by their cure chemistry and only to a lesser extent by their formulation. A relative ranking of the heat stability of the sealants is derived based on the percentage change of their mechanical properties.
Use of Q-U-V to Predict the Edge Compatibility of Commercial Sealants with Laminated Glass
Authors: Gomez IL , Colella MR
Published: March 2009

An important factor to be considered when commercial sealants contact the edges of laminated glass is that of the compatibility of the sealants with the polyvinyl butyral (PVB) interlayer. Lack of compatibility with sealants, which is manifested by visible narrow edge-band defects in the laminates, is more detrimental to the aesthetic than to any of the other functional properties of these laminates. For the most part, however, the functionality of sealants is unaffected by these compatibility problems since they are created by the by-products of the normal curing reaction of the sealants. The information presented here is aimed at helping laminated glass users make more informed judgments regarding the selection of sealants. It uses mainly the Q-U-V laboratory accelerated weathering tester to predict these compatibility problems.
Criteria for Design and Testing of Sealants Used in Single-Ply Roofing and Waterproofing Systems
Authors: Gish LE
Published: March 2009

Roofing membranes are subjected to large temperature gradients, ultraviolet radiation from the sun, building movement, constant and intermittent water immersion, and microbial attack. Waterproofing membranes are subjected to many of the same stresses. In both cases sealants are generally used as the first line of defense for the seams in the membrane system. Each of the single ply roofing and waterproofing systems in use today utilizes at least one if not several sealants whose application is unique to that system.

Sealants used with each of the generic single ply types are described in terms of their function and required performance.

Criteria for testing such sealant products are discussed with emphasis on the design and interpretation of meaningful laboratory test methods, those that will rapidly predict the performance of a candidate sealant in conditions of actual use.

Systems discussed include EPDM, Neoprene, Butyl, and Hypalon elastomers, CPE and PVC thermoplastics, and modified bitumen.
Sealant Back-up Material and New Developments
Authors: Schroeder MJ , Hovis EE
Published: March 2009

During polyolefin extrusion trials in the first quarter of 1988, we were experimenting with polyolefin blends trying to develop a high resilient backing material which was suitable for use in a joint with slow curing, low modulus, self-leveling sealants. One of the requirements for this new backing material was better compression recovery than traditional closed cell polyethylene foams.

While working with polyolefin blends to increase recovery, it was discovered that a dimensionally stable, open cell/closed cell structure could be extruded with the added benefit of non-outgassing when ruptured.
European Experiences of Sealants in Service, Correlation to Results from Laboratory Tests
Authors: Burström PG
Published: March 2009

Various examinations of sealant joints show that there are many problems with leakage, even in fairly new buildings. Two main reasons have been that the sealant properties are overrated and that the joint design or workmanship is poor due to lack of knowledge about the basic requirements and the material properties.

The failure mechanism of an elastic sealant is described. This serves as a basis for a suggested engineering approach for designing sealant joints. A methodology is described by which aging and durability properties of a sealant can be evaluated. Examples of test results for various sealants are given.

Today there are sealants on the European market with excellent durability and high movement capability. The conditions are therefore good for a service life of at least 25 years for many selants. The problem is to get these sealants designed and used in the proper way.
Sealant Usage for Exterior Insulation and Finish Systems
Authors: Williams MF , Williams BL
Published: March 2009

Finish coat delamination is a prime reason for sealant joint failure in certain Exterior Insulation & Finish Systems (EIFS). Several factors contribute to the delamination process and subsequent failure at sealant joints. General design, specification and application procedures for sealant joints on EIFS are discussed with specific recommendations for avoiding this common cause of failure.
Why Construction Sealants Fail -- An Overview
Authors: Warseck KL
Published: March 2009

This article is intended as an overview of why construction sealants fail in the “real world”. These reasons can be categorized by design errors, application errors and materials failures. Design failures are those which occur from the work of the design professional, such as improper joint sizing. Application failures are those that occur due to problems during installation, such as lack of surface preparation. Materials failures result not only from problems with the sealant itself, but also because of the substrates to which they are applied.
Status of High-Rise Building Sealants in the U.S.
Authors: Panek JR
Published: March 2009

Polysulfide sealants were the only elastomeric sealants available for the modern curtainwall beginning in the early 1950's. They had rapid growth until the early 60's with sales of 3 million kgs., when solvent acrylic, urethane, and silicone sealants were introduced and broke the monopoly of polysulfides. By 1975 the above four sealants had sales in the range of 3 to 4.5 million kgs. By 1988 silicone sales were 10 million kgs followed by urethane with 6 million kgs. Polysulfide and solvent acrylic sealants totaled 3 million kgs. Butyl sealants and acrylic latex sealants are not really competitive with the above.
The Nondestructive Characterization of Corrosion
Authors: Clark WG , Metala MJ
Published: March 2009

Recent advances in nondestructive evaluation (NDE) technology have led to improved methods for quality control and in-service inspection. In addition, these same advancements have led to the development of new options for material diagnostics. No longer are NDE considerations directed only at crack detection and sizing. Detailed discontinuity characterization has become a major objective of much NDE work underway today. Specifically, this work is aimed at the creation of quantitative NDE methods which offer a rational alternative to destructive metallography for material evaluation. While this goal may be some ways off, significant progress has been made in the NDE characterization of corrosion-induced degradation. Nowhere have these developments been more evident than in the characterization of corrosion phenomena in small-diameter, heat exchanger tubing. This paper presents results from a continuing program designed to establish improved inspection methods for the assessment of corrosion degradation in nickel-alloy nuclear steam generator tubing. The major focus is directed at unique test methods and data analysis techniques which offer the potential to identify and discriminate between different kinds of corrosion degradation. While the results highlight success in the assessment of tubing, the concepts and general observations are equally applicable to other components.
Field Soil Corrosivity Testing—Engineering Considerations
Authors: Palmer JD
Published: March 2009

The state of the art in soil corrosivity testing was evaluated, with particular emphasis on field and in-situ tests that can be performed with reasonable accuracy by nonscientific personnel. Parameters reviewed include resistivity, pH, redox potential, moisture content, chloride levels, structure/soil potential, and microbiological activity. The reliability of in-situ tests versus laboratory tests is examined. Particular emphasis is placed on buried and immersed ferrous materials. A distinction is made between studies intended to determine the soil factors affecting the integrity of intended new installations and studies which examine the condition of the existing facilities and the relationship of soil parameters to structure condition and anticipated life. The latter circumstance is becoming increasingly evident as infrastructure rehabilitation studies focus on the condition and future life expectancy of buried facilities. Several approaches to expected life prediction are reviewed. Emphasis is focused on information presented in ASTM STP 741, Underground Corrosion, and ASTM STP1013, Effects of Soil Characteristics on Corrosion. The applicability of the ASTM Method for Field Measurement of Soil Resistivity Using the Wenner Four-Electrode Method (G 57-78) and the ASTM Test Method for pH of Soil for Use in Corrosion Testing (G 51-84) is considered. The available information is consolidated into recommended practices for soil corrosivity evaluations.
Derivation of a Damage Function for Galvanized Steel Structures: Corrosion Kinetics and Thermodynamic Considerations
Authors: Spence JW , Haynie FH
Published: March 2009

A damage function for predicting the corrosion of galvanized steel structures by wet and dry deposition has been developed from the thermodynamics and kinetics of atmospheric corrosion chemistry. The function mathematically expresses the competing reactions for the buildup and dissolution of the basic zinc-carbonate corrosion film with exposure time. Major findings as expressed by the theoretical function are as follows: 1. During periods of surface wetness, SO2 reaching the surface reacts stoichiometrically with the zinc. 2. Rain acidity reacts stoichiometrically with the zinc. 3. The corrosion film of basic zinc carbonate is soluble in clean rain. The dissolution depends on the residence time of rain on the galvanized steel surface. 4. Deposition velocity controls the rate of corrosion of galvanized steel structures by gaseous SO2 during periods of wetness.

This paper recommends testing the applicability of the proposed damage function with field corrosion data that is being acquired by the Bureau of Mines and the U.S. Environmental Protection Agency and with corrosion data from prior field exposure studies. In this manner a validated damage function should be developed for conducting an assessment of acid deposition to galvanized steel structures.
A Study of Large Sets of ASTM G 84 Time-of-Wetness Sensors
Authors: Heckher JJ , Boulanger J , Noël D , Dufresne R , Pinon C
Published: March 2009

Three sets of 32 to 39 ASTM time-of-wetness G 84-84 sensors were exposed during summer and winter in Montreal. For the summer periods, all sensors responded well to rain but had a very different sensitivity to dew, with some sensors never responding to dew. For the winter period all sensors responded well to condensation below the freezing point. The ASTM sensor selection criteria are sound for atmospheres having a small dew time-of-wetness compared to the rain time-of-wetness. For atmospheres having a large dew time-of-wetness, the sensors should be tested in order to discard those which are not very sensitive to the dew. A sensitivity factor for each sensor within a given set can be determined experimentally in order to increase the precision of the time-of-wetness values.
Application of the Critical Pitting Temperature Test to the Evaluation of Duplex Stainless Steel
Authors: Kane RD , Wilhelm SM , McIntyre DR
Published: March 2009

This paper presents the results of a laboratory testing program whose objective was to evaluate the localized corrosion resistance of duplex stainless steel weldments and to validate screening test methods for this task. The results of sodium chloride (NaCl) critical pitting temperature (CPT) tests, ferric chloride tests, electrochemical polarization (pitting) scans, and simulated service environment tests are presented. These studies revealed that the sodium chloride CPT screening test provided the best correlation with long-term simulated service environment tests in terms of rank ordering resistance to pitting and in the morphology of attack. In terms of pitting resistance of duplex stainless steel weldments, it was found that pitting susceptibility could be related to both ferrite content and pitting index (PI) of the weld metal. At equivalent values of PI and ferrite content, the weld metal had higher resistance to pitting than the base metal.
Simple Models/Practical Answers Using the Electrochemical Impedance Technique
Authors: Silverman DC
Published: March 2009

One practical use of the electrochemical impedance technique is rapid screening of either alloy corrosion resistance or process corrosivity as a function of process conditions. Curve-fitting of the impedance spectra using simple circuit analogue models can allow polarization or charge transfer resistances to be extracted even when there is limited understanding or characterization of the system under study. Practical corrosion predictions can be made from these results. Some successes and shortcomings in the technology are explored using corrosion of steel and 304SS in several environments. The results show that corrosion rates between 2.5 × 10-4 and 250 mm/year can be estimated and predictions made even when only limited information on the solution chemistry and corrosion mechanism is available. Some discussion is presented on how one can gain confidence that the model circuit elements are providing reliable information.
Electrochemical Impedance Measurements for Evaluating and Predicting the Performance of Organic Coatings for Atmospheric Exposure
Authors: Simpson TC , Moron PJ , Hampel H , Davis GD , Shaw BA , Arah CO , Fritz TL , Zankel KL
Published: March 2009

This paper focuses on the use of electrochemical impedance spectroscopy (EIS) as a predictive tool in assessing organic coating deterioration. EIS has been used by a number of investigators in recent years to assess coating deterioration. Good correlations between EIS data in immersion environments and other deterioration parameters exist (primarily evaluated visually). The potential use of EIS for sensing coating degradation in atmospheric exposure has not been fully evaluated. We have recently developed an atmospheric electrochemical monitor (ATMEIS) designed to assess degradation of painted metal substrates during atmospheric exposure using EIS. The monitor consists of a painted steel coupon upon which a gold electrode was electron-beam deposited to serve as a reference/counter electrode. EIS measurements are made between the underlying steel substrate and the gold reference/counter electrode residing on the coating surface. The ATMEIS has been tested both in immersion exposure and in an atmospheric exposure chamber and has been found to generate EIS data consistent with those predicted for a painted metal coupon in an aggressive environment. This aper reports the details of recent studies by other investigators in immersion environments using EIS to sense coating deterioration and discusses the design and testing of our ATMEIS monitor for atmospheric EIS.
Electrochemical Screening of Synergism of urfactants in the Inhibition of Corrosion of Aluminum by Silicate
Authors: Hirozawa ST , Coker DE
Published: March 2009

The passivation current obtained from galvanostaircase polarization curves indicates whether aluminum can be passivated in a given environment. The change in passivation current with increased passivation of aluminum is much more sensitive than changes in breakdown or corrosion potentials. This great sensitivity of passivation current was used to develop a rapid screening method to determine whether a surfactant was synergistic or antisynergistic with the inhibition of aluminum by silicate at elevated temperature. The passivation current was also used to screen surfactants for inhibition of aluminum corrosion in the absence of silicate.
Depth of Investigation and Vertical Resolution of Surface Geoelectric Arrays
Authors: Szalai Sándor , Novák Attila , Szarka László
Published: March 2009

Depth of investigation and vertical resolution values are determined and tabulated for 30 surface geoelectric arrays that have non-zero response, i.e., a depth of investigation characteristic (DIC) function due to a buried thin horizontal sheet. In accord with experience, results show a general reciprocal relationship between depth of investigation and vertical resolution. The most frequently used arrays in multi-electrode studies (i.e., Wenner-[Formula: see text], Wenner-[Formula: see text], Schlumberger, dipole-axial arrays and the pole-dipole array) offer reasonable compromises between depth of investigation and vertical resolution. Depth of investigation can be increased by using the pole-pole array; vertical resolution can be improved with, for example, the [Formula: see text] or [Formula: see text] arrays. Current focussing does not increase the depth of investigation for the horizontal thin-sheet model. The complete set of depth of investigation and vertical resolution values permits exact physical comparison of various geoelectric arrays and provides simple but useful rules for practical geoelectric applications, e.g., how to develop multi-electrode systems with higher vertical resolution, or how to select arrays to satisfy special exploration requirements.