4.1 Damage to pipe coating is almost unavoidable during transportation and construction. Breaks or holidays in pipe coatings may expose the pipe to possible corrosion since, after a pipe has been installed underground, the surrounding earth will be moisture-bearing and will constitute an effective electrolyte. Applied cathodic protection potentials may cause loosening of the coating, beginning at holiday edges. Spontaneous holidays may also be caused by such potentials. This test method provides accelerated conditions for cathodic disbondment to occur and provides a measure of resistance of coatings to this type of action.4.2 The effects of the test are to be evaluated by physical examinations and monitoring the current drawn by the test specimen. Usually there is no correlation between the two methods of evaluation, but both methods are significant. Physical examination consists of assessing the effective contact of the coating with the metal surface in terms of observed differences in the relative adhesive bond. It is usually found that the cathodically disbonded area propagates from an area where adhesion is zero to an area where adhesion reaches the original level. An intermediate zone of decreased adhesion may also be present.4.3 Assumptions associated with test results include:4.3.1 Maximum adhesion, or bond, is found in the coating that was not immersed in the test liquid, and4.3.2 Decreased adhesion in the immersed test area is the result of cathodic disbondment.4.4 Ability to resist disbondment is a desired quality on a comparative basis, but disbondment in this test method is not necessarily an adverse indication of coating performance. The virtue of this test method is that all dielectric-type coatings now in common use will disbond to some degree, thus providing a means of comparing one coating to another.4.5 The current density appearing in this test method is much greater than that usually required for cathodic protection in natural environments.1.1 This test method covers accelerated procedures for simultaneously determining comparative characteristics of coating systems applied to steep pipe exterior for the purpose of preventing or mitigating corrosion that may occur in underground service where the pipe will be in contact with natural soils and will receive cathodic protection. They are intended for use with samples of coated pipe taken from commercial production and are applicable to such samples when the coating is characterized by function as an electrical barrier.1.2 This test method is intended to facilitate testing of coatings where the test cell is cemented to the surface of the coated pipe specimen. This is appropriate when it is impractical to submerge or immerse the test specimen as required by Test Methods G8, G42, or G80. Coating sample configuration such as flat plate and small diameter pipe may be used, provided that the test procedure remains unchanged.21.3 This test method allows options that must be identified in the report.1.4 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

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定价： 590元 加购物车

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5.1  Hydrogen is delivered to fuel cell powered automotive vehicles and stationary appliances at pressures up to 87.5 MPa. The quality of hydrogen delivered is a significant factor in maximizing fuel cell efficiency and life span. Contamination can occur during the production of fuel cell feed gases, contaminating storage containers, station tubing, and fuel lines used for fuel delivery. Collection of a representative fuel sample without the introduction of contaminants even as low as parts-per-billion (ppb) per contaminant during collection is crucial for assessing the quality of fuel in real world applications.5.2 This practice is intended for application to high pressure, high purity hydrogen; however, the apparatus design and sampling techniques may be applicable to collection of other fuel cell feed gases. Many of the techniques used in this practice can be applied to lower pressure/lower purity gas streams.1.1 This standard practice describes a sampling procedure of high pressure hydrogen at fueling stations operating at 35 or 70 megapascals (MPa) using a hydrogen quality sampling apparatus (HQSA).1.2 This practice does not include the analysis of the acquired sample. Applicable ASTM standards include but are not limited to test methods referenced in Section 2 of this practice.1.3 This practice is not intended for sampling and measuring particulate matter in high pressure hydrogen. For procedures on sampling and measuring particulate matter see ASTM D7650 and D7651.1.4 The values stated in SI units are standard. The values stated in inch-pounds are for information only.1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

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5.1 This guide applies to flexible closed cell insulation tubing and sheet materials manufactured according to Specifications C534 and C1427. This standard is intended to provide a basic guide for installing these types of materials.5.2 Confirm application use temperature is consistent with specified use temperature for material as defined in ASTM Specifications unless otherwise agreed upon with the manufacturer. There are different grades for each of the insulation types referred to in this guide, material and grade installed should be that specified.5.3 This guide is not intended to cover all aspects associated with installation for all applications, consult the National, Commercial Industrial Insulation Standards (MICA Manual) or the specific product manufacturer for recommendations, or both. See ASHRAE Handbook (Fundamentals – Chapter 23) and ASHRAE Handbook (Refrigeration – Chapter 10).1.1 This guide covers recommended installation techniques for flexible closed cell pre-formed insulation in tube or sheet form. This guide is applicable to materials manufactured in accordance with Specification C534 (Elastomeric based insulation) or Specification C1427 (polyolefin based insulation). The materials covered in this guide encompass a service temperature of –297 to 300°F (–183 to 150°C) as indicated in the material specifications referenced above. Many of the recommendations made are specific to below ambient applications only.1.2 The purpose of this guide is to optimize the thermal performance and longevity of installed closed cell flexible insulation systems. By following this guide, the owner, and designer can expect to achieve the energy savings expected and prevention of condensation under the specified design conditions. This document is limited to installation procedures and does not encompass system design.1.3 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

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4.1  Zeolites Y and X, particularly for catalyst and adsorbent applications, are a major article of manufacture and commerce. Catalysts and adsorbents comprising these zeolites in various forms plus binder and other components have likewise become important. Y-based catalysts are used for fluid catalytic cracking (FCC) and hydrocracking of petroleum, while X-based adsorbents are used for desiccation, sulfur compound removal, and air separation.4.2 The unit cell dimension of a freshly synthesized faujasite-type zeolite is a sensitive measure of composition which, among other uses, distinguishes between the two synthetic faujasite-type zeolites, X and Y. The presence of a matrix in a Y-containing catalyst precludes determination of the zeolite framework composition by direct elemental analysis.4.3 Users of the test method should be aware that the correlation between framework composition and unit cell dimension is specific to a given cation form of the zeolite. Steam or thermal treatments, for example, may alter both composition and cation form. The user must therefore determine the correlation that pertains to his zeolite containing samples.3 In addition, one may use the test method solely to determine the unit cell dimension, in which case no correlation is needed.4.4 Other crystalline components may be present in the sample whose diffraction pattern may cause interference with the selected faujasite-structure diffraction peaks. If there is reason to suspect the presence of such components, then a full diffractometer scan should be obtained and analyzed to select faujasite-structure peaks free of interference.1.1 This test method covers the determination of the unit cell dimension of zeolites having the faujasite crystal structure, including synthetic Y and X zeolites, their modifications such as the various cation exchange forms, and the dealuminized, decationated, and ultra stable forms of Y. These zeolites have cubic symmetry with a unit cell parameter usually within the limits of 24.2 and 25.0 Å (2.42 and 2.50 nm).1.2 The samples include zeolite preparation in the various forms, and catalysts and adsorbents containing these zeolites. The zeolite may be present in amounts as low as 5 %, such as in a cracking catalyst.1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

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定价： 646元 加购物车

定价： 515元 加购物车

4.1 This practice describes a cell adhesion method that can be used to provide a detachment percent at a given RCF for cells that have adhered to a substrate, typically for a short time. The information generated by this practice can be used to obtain a semi-quantitative measurement of the adhesion of cells to either an uncoated or pre-coated substrate, when compared to a reference (adherent) cell type on the same substrate. As described in Reyes and Garcia (2003), it is recommended that the 50 % point be used for either ligand concentration or RCF for the most robust measurement of adhesion strength. The adhesion may vary due to changes in the phenotype of the cells or as a result of the specific properties of the surface. The substrate may include tissue culture-treated polystyrene, biomaterials, or bioactive surfaces. If the substrate is a hydrogel, care must be taken to avoid cohesive failure in the hydrogel (that is, detached cells have pulled away fragments of gel). The coating may consist of (but is not limited to) the following: natural or synthetic biomaterials, hydrogels, components of extracellular matrix (ECM), ligands, adhesion or bioactive molecules, genes, or gene products. Cell concentration is also critical, as use of too high a concentration of cells may result in cells detaching as a sheet, rather than as individual cells. This centrifugation approach, once validated, may be applicable for quality control (QC) and product development. However, until the method is correlated to other measures of cell attachment, the current method should be run in parallel with other known measures of cell adhesion.4.2 This practice does not cover methods to quantitate changes in gene expression, or changes in biomarkers, as identified by immunostaining. This practice additionally does not cover quantitative image analysis techniques. In some cases, the change in adhesive properties may reflect on the degree of differentiation or de-differentiation of the cells. However, it is worth noting that adhesive interactions do not necessarily reflect the differentiation state of a particular cell type, although in many instances they do. (See X1.3 for application to the adhesion of chondrocytes.)1.1 This practice covers a centrifugation cell adhesion assay that can be used to detect changes in adhesive characteristics of cells with passage or treatments. This approach measures the force required to detach cells from a substrate. Adhesion, among many variables, may vary due to changes in the phenotype of the cells.1.2 This practice does not cover methods to verify the uniformity of coating of surfaces, nor does it cover methods for characterizing surfaces.1.3 The cells may include adult, progenitor, or stem cells from any species. The types of cells may include chondrocytes, fibroblasts, osteoblast, islet cells, or other relevant adherent cell types.1.4 This practice does not cover methods for isolating or harvesting of cells. This practice does not cover methods to quantitate changes in gene expression, or changes in biomarker type or concentration, as identified by immunostaining. Nor does this practice cover quantitative image analysis techniques.1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

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This specification covers flexible closed-cell or non-interconnecting cellular products, the elastomer content of which is predominantly poly(vinyl chloride) foam or copolymers thereof. Materials shall be produced in sheet, strip, molded, or simple specific shapes. Complete details about apparatuses needed, specimen preparation, and procedures for the testing of compression deflection, compression set under constant deflection, and water absorption are thoroughly itemized.1.1 This specification covers flexible closed-cell or non-interconnecting cellular products, the elastomer content of which is predominantly poly(vinyl chloride) or copolymers thereof.1.2 In the case of conflict between the provisions of this specification and those of detailed specifications or methods of test for a particular product, the latter shall take precedence.1.3 Reference to the methods for testing closed-cell poly(vinyl chloride) contained herein shall specifically state the particular test or tests desired and not refer to these methods of test as a whole.1.4 The values stated in SI units are to be regarded as the standard. The inch-pound units given in parentheses are for information only.1.5 The following precautionary statement pertains to the test method portions only of this specification: This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.NOTE 1: There is no known ISO equivalent to this standard.1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

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4.1 Autologous PRP and platelet gels are utilized in a wide range of orthopedic, sports medicine, regenerative medicine, and surgical applications (3-5). PRP and platelet gels are layered, sprayed, injected, molded, or packed, alone or in combination with graft material or TEMPs, into a variety of anatomical sites, tissues, and voids (3, 6). These platelet concentrates can provide an assortment of bioactive molecules, cells, and physical properties that are potentially attractive for promoting healing and other cell therapy applications (7). Unfortunately, the term “platelet-rich plasma” or “PRP,” which is ubiquitous in early and contemporary medical literature related to a variety of platelet concentrates, only unambiguously denotes one critical parameter of a platelet suspension—increased platelet concentration. Without further context, this common description of PRP offers no information about other important physical and cellular aspects of platelet concentrations. As scientific and clinical understanding of PRP and other cellular therapies increases standardization of nomenclature and terminology is critical for defining key properties, standardizing processing parameters and techniques, and developing repeatable assays for quality assurance and scientific evaluation (5, 8-13). This guide outlines basic guidelines to describe key properties of unique PRP and platelet gel formulations in a standardized fashion. Reliable, standardized descriptions can provide valuable context to PRP end users, such as clinicians seeking a PRP or platelet gel with certain biological attributes or scientific investigators seeking to duplicate a published formulation or to correlate a given PRP or platelet gel feature to other biological properties or outcomes.1.1 This guide defines terminology and identifies key fundamental properties of autologous platelet-rich plasma (PRP) and PRP-derived platelet gels intended to be used for tissue engineered medical products (TEMPS) or for cell therapy applications. This guide provides a common nomenclature and basis for describing notable properties and processing parameters for PRP and platelet gels that may have utility for manufacturers, researchers, and clinicians. Further discussion is also provided on certain aspects of PRP processing techniques, characterization, and quality assurance and how those considerations may impact key properties. The PRP characteristics outlined in this guide were selected based n a review of contemporary scientific and clinical literature but do not necessarily represent a comprehensive inventory; other significant unidentified properties may exist or be revealed by future scientific evaluation. This guide provides general recommendations for how to identify and cite relevant characteristics of PRP, based on broad utility; however, users of this standard should consult referenced documents for further information on the relative import or significance of any particular PRP characteristic in a particular context.1.2 The scope of this guide is confined to aspects of PRP and platelet gels derived and processed from autologous human peripheral blood. Platelet-rich plasma, as defined within the scope of this standard, may include leukocytes.1.3 The scope of this document is limited to guidance for PRP and platelet gels that are intended to be used for TEMPS or for cell therapy applications. Processing of PRP, other platelet concentrates or other blood components for direct intravenous transfusion is outside the scope of this guide. Apheresis platelets and other platelet concentrates utilized in transfusion medicine are outside the scope of this document. Production of PRP or platelet gels for diagnostic or research applications unrelated to PRP intended for TEMPS or cell therapy is also outside the scope of this guide. Fibrin gels devoid of platelets are also excluded from discussion within this document.1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

定价： 590元 加购物车

定价： 646元 加购物车

定价： 590元 加购物车

定价： 646元 加购物车