1.1 Cellular plastics are composed of the membranes or walls of polymer separating small cavities or cells. These cells may be interconnecting (open cell), non-connecting (closed cell), or any combination of these types. This test method determines numerical values for open cells. It is a porosity determination, measuring the accessible cellular volume of a material. The volume occupied by closed cells is considered to include cell walls. Since any conveniently sized specimen can only be obtained by some cutting operation, a fraction of the closed cells will be opened during sample preparation and will be included as open cells. 1.2 This test method consists of three procedures: 1.2.1 Procedure A , designed to correct for cells opened during sample preparation, by measuring cell diameter, calculating, and allowing for surface volume; 1.2.2 Procedure B , designed to correct for cells opened in sample preparation, by cutting and exposing new surface area equal to the surface area of the original sample dimension, and 1.2.3 Procedure C , which does not correct for cells opened during sample preparation and gives good accuracy on predominantly highly open-celled materials. The accuracy decreases as the closed cell content increases and as the cell size increases. 1.3 The values as stated in SI units are to be regarded as the standard. The values in parentheses are given for information only. 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. Specific precautionary statements are given in Notes 2, 4, and 8. Note 1-This test method and ISO 4590-1981 use the same basic principles but are significantly different in experimental detail.

定价： 0元 / 折扣价： 0 元

5.1 The laboratory weathering procedure will generate data that can be used to: (1) determine whether a solid material will produce an acidic, alkaline, or neutral effluent, (2) identify solutes in the effluent that represent dissolved weathering products formed during a specified period of time, (3) determine the mass of solute release, and (4) determine the rate at which solutes are released (from the solids into the effluent) under the closely controlled conditions of the test.5.2 Data generated by the laboratory weathering procedure can be used to address the following objectives: (1) determine the variation of drainage quality as a function of compositional variations (for example, iron sulfide and calcium+magnesium carbonate contents) within individual mine-rock lithologies, (2) determine the amount of acid that can be neutralized by the sample while maintaining drainage pH ≥6.0 under the conditions of the test, (3) estimate mine-rock weathering rates to aid in predicting the environmental behavior of mine rock, and (4) determine mine-rock weathering rates to aid in experimental design of site-specific kinetic tests.5.3 The laboratory weathering procedure provides conditions conducive to oxidation of solid material constituents and enhances the transport of weathering reaction products contained in the resulting weekly effluent. This is accomplished by controlling the exposure of the solid material sample to such environmental parameters as reaction environment temperature and application rate of water and oxygen.5.4 Because efficient removal of reaction products is vital to track mineral dissolution rates during the procedure, laboratory leach volumes are large per unit mass of rock to promote the rinsing of weathering reaction products from the mine-rock sample. A comparison of laboratory kinetic tests with field tests has shown that more reaction products from mineral dissolution are consistently released per unit weight and unit time in laboratory weathering tests (9). For example, sulfate release rates observed in laboratory tests of metal-mine rock have been reported to be 3 to 8 times those for small-scale field test piles of Duluth Complex rock (10), and from 2 to 20 times those for small-scale field test piles of Archean greenstone rock (11). A greater increase is anticipated when laboratory rates are compared with field rates measured from operational waste-rock piles.5.5 Fundamental assumptions governing Options A and B of the procedure:5.5.1 Option A—An excess amount of air pumped up through the sample during the dry- and wet-air portions of the weekly cycle reduces the potential for oxidation reaction rates being limited by low-oxygen concentrations. Weekly leaches with low-ionic-strength water promote the removal of leachable mineral dissolution products produced from the previous week's weathering cycle. The purpose of the three-day dry-air portion of the weekly cycle is to evaporate some of the water that remains in the pores of the sample after the weekly leach without totally drying out the sample. Consequently, sample saturation is reduced and air flow is enhanced. During the dry-air portion of the cycle, the oxygen diffusion rate through the sample may increase several orders of magnitude as compared to its diffusion rate under more saturated conditions of the leach. This increase in the diffusion rate under near-dryness conditions helps promote the oxidation of such constituents as iron sulfide. Additionally, evaporation from the three days of dry air increases pore water cation/anion concentrations and may also cause increased acidity (for example, by increasing the concentration of hydrogen ion generated from previously oxidized iron sulfide). Increased acid generation will enhance the dissolution of additional sample constituents. As evaporation continues, the remaining water may become oversaturated with respect to some mineral phases, consequently causing them to precipitate. Some precipitated minerals are potential sources of acidity when re-dissolved (for example, melanterite, FeSO4·7H2O; and jarosite, K2Fe6(OH)12(SO4)4). Compared to the three days of dry air where the pore-water mass decreases over time, the wet (saturated)-air portion of the weekly cycle helps maintain a relatively constant mass of pore water in the sample (12). This may help promote some diffusion of weathering products (for example, re-dissolved precipitation products) in the remaining pore water without totally saturating the sample and adversely affecting oxygen diffusion.NOTE 1: Under idealized conditions (that is, infinite dilution in air and water), published oxygen diffusion rates in air are five orders of magnitude greater than in water (0.178 cm2 s–1 versus 2.5 × 10–5 cm2·s–1 at 0 and 25 °C, respectively) (13).5.5.2 Option B—In contrast to Option A, Option B protocol does not include dry air or wet air introduction to the humidity cells during the weekly cycle. Instead, Option B requires that temperature and relative humidity be maintained within a constant range by storing the cells in an environmentally controlled enclosure during the six days following the weekly 500- or 1000-mL leach. Consequently, oxygen is delivered to the cells by diffusion (and possibly advection) of ambient air, rather than by pumping. Because it lacks a dry-air cycle, more interstitial water is retained in the Option B sample than in the Option A sample during the weekly cycle. Furthermore, the interstitial water content for Option B is more constant than that in Option A during the weekly dry-air cycle. In addition, the interstitial water content for Option B is less variable over the course of testing than that in Option A (14).5.6 This test method has been conducted on metal-mine wastes to classify their tendencies to produce acidic, alkaline, or neutral effluent, and to measure the concentrations of selected inorganic components leached from the waste (2, 3, 14-16).NOTE 2: Interlaboratory testing of this method to date has been confined to mine waste rock. The method has not been tested for applicability to metallurgical processing waste. Although the method has been applied by some practitioners to finely ground metallurgical processing wastes such as mill tailings, those materials were not included in the interlaboratory testing of the method. Consequently, modifications of this method might be necessary to deal with problems associated with finely ground materials, which would make this method as written inappropriate for kinetic testing of finely ground materials. For kinetic testing of finely ground materials, please refer to the biological acid production potential method in the appendix of Test Methods E1915 or other kinetic methods accepted by the regulatory jurisdiction.5.7 The following are examples of parameters for which the scheduled weekly, semi-monthly, or monthly collected effluent may be analyzed (see 11.5.2 for suggested effluent collection frequency):5.7.1 pH, Eh (oxidation/reduction potential), and conductivity (see Test Methods D1293, D1498, and D1125, respectively, for guidance);5.7.2 Alkalinity/acidity values (see Test Methods D1067 for guidance);5.7.3 Cation and anion concentrations;5.7.4 Metals and trace metals concentrations.5.8 An assumption used in this test method is that the pH of each of the leachates reflects the progressive interaction of the interstitial water with the acid-generating or acid-neutralizing capacity, or both, of the solid material under specified laboratory conditions.5.9 This test method produces leachates that are amenable to the determination of both major and minor constituents. It is important that precautions be taken in sample collection, filtration, preservation, storage, and handling to prevent possible contamination of the samples or alteration of the concentrations of constituents through sorption or precipitation.5.10 The leaching technique, rate of leach water addition, liquid-to-solid ratio, and apparatus size may not be suitable for all types of solid material.5.11 Notable differences have been observed between Option A and Option B protocols:5.11.1 Water retention in the solid material sample between weekly leaches is more variable for Option A than in Option B; for Option A, standard deviations from the mean water retention can range from 20 to 60 % of the mean value; comparable values for Option B have been reported at less than 9 % (14).5.11.2 Greater water retention in Option B cells may favor dissolution of, and consequent acid neutralization by, magnesium-bearing minerals; increased retention may facilitate transport of acidic reaction products from iron-sulfide minerals to magnesium-bearing minerals (14).5.11.3 Comparisons of sulfate mass release from the same sample subjected to Option A and Option B protocols indicate no significant difference in sulfate concentration as a result of water-retention variation between protocols (14). This suggests the increased water retention of Option B does not limit oxygen diffusion to the extent that sulfide mineral oxidation rates are reduced (14). However, samples containing greater than 7 % sulfur have not as yet been subjected to comparable Option A and Option B protocol studies.NOTE 3: Examples of products from the test include the following: (1) effluent pH, acidity/alkalinity, and specific conductance; (2) cumulative mass release of individual solutes; and (3) release rates for individual solutes (for example, the average release of μg sulfate/g of solid material sample/week). The dissolution time required for depletion of estimated NP and the subsequent duration of acid generation can be estimated using the values generated in items (2) and (3) above (15).1.1 This kinetic test method covers a laboratory weathering procedure that (1) enhances reaction-product transport in the aqueous leach of a solid material sample of specified mass, and (2) measures rates of weathering-product mass release. Soluble weathering products are mobilized by a fixed-volume aqueous leach that is performed and collected weekly. Leachate samples are analyzed for pH, alkalinity/acidity, specific conductance, sulfate, and other selected analytes.1.1.1 This test method is intended for use to meet kinetic testing regulatory requirements for mining waste rock and ores sized to pass a 6.3-mm (0.25-in.) Tyler screen.1.1.2 Interlaboratory testing of this method has been confined to mine waste rock. Application of this test method to metallurgical processing waste (for example, mill tailings) is outside the scope of the test method.1.2 This test method is a modification of a laboratory weathering procedure developed originally for mining wastes (1-3).2 However, it may have useful application wherever gaseous oxidation coupled with aqueous leaching are important mechanisms for contaminant mobility.1.3 This test method calls for the weekly leaching of a well-characterized solid material sample (weighing at least 1000 g) with water of specified purity, and the collection and chemical characterization of the resulting leachate. Test duration is determined by the user’s objectives of the test. See Guide D8187.31.4 As described, this test method may not be suitable for some materials containing plastics, polymers, or refined metals. These materials may be resistant to traditional particle size reduction methods.1.5 Additionally, this test method has not been tested for applicability to organic substances and volatile matter.1.6 This test method is not intended to provide leachates that are identical to the actual leachate produced from a solid material in the field or to produce leachates to be used as the sole basis of engineering design.1.7 This test method is not intended to simulate site-specific leaching conditions. It has not been demonstrated to simulate actual disposal site leaching conditions. Furthermore, the test is not designed to produce effluents that are in chemical equilibrium with the solid phase sample.1.8 This test method is intended to describe the procedure for performing the laboratory weathering of solid materials. It does not describe all types of sampling and analytical requirements that may be associated with its application.1.9 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.9.1 Exception—The values given in parentheses are for information only.1.10 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.1.11 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.

定价： 843元 / 折扣价： 717 元 加购物车

定价： 590元 / 折扣价： 502 元 加购物车

定价： 590元 / 折扣价： 502 元 加购物车

1.1 Scope and References 1.1.1 This standard applies to stationary fuel cell power systems that are packaged, self-contained or factory matched packages of integrated systems (see 1.2.1), which through electrochemical reactions and other processes, ge

定价： 5688元 / 折扣价： 4835 元

Scope 1.1.1 This Standard applies to ac and dc type portable fuel cell power systems, with a rated output voltage not exceeding 600 V, for commercial, industrial, and residential indoor and outdoor use in non-hazardous locations, in accordance with the R

定价： 5005元 / 折扣价： 4255 元

定价： 590元 / 折扣价： 502 元 加购物车

5.1 This test method is intended to be used in specifications where porosity of cellular plastics has a direct bearing on their end use. For example, for thermal insulation applications, a high percentage of closed cells is necessary to prevent escape of gases and to promote low thermal conductivity. In flotation applications, high closed-cell content generally reduces water absorption.5.2 Before proceeding with this test method, reference shall be made to the specification of the material being tested. Any test specimen preparation, conditioning, or dimensions, or both, and testing parameters covered in the materials specification shall take precedence over those mentioned in this test method. If there are no material specifications, then the default conditions apply.1.1 This test method covers cellular plastics, which are composed of membranes or walls of polymer separating small cavities or cells. These cells may be interconnecting (open cell), non-connecting (closed cell), or any combination of these types. This test method determines numerical values for open cells. It is a porosity determination, measuring the accessible cellular volume of a material. The remaining volume is that occupied by closed cells and cell walls. Since any conveniently sized specimen is typically obtained by some cutting operation, a fraction of the closed cells will be opened by specimen preparation and will be included as open cells, (see Note 2).1.2 This test method provides good accuracy on predominantly highly open-celled materials. By not accounting for closed cells that were opened during specimen preparation, the accuracy decreases as the closed cell content increases and as the cell size increases.1.3 The values as stated in SI units are to be regarded as the standard. The values in parentheses are given for reference only.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.NOTE 1: This test method and ISO 4590 use the same basic principles but are significantly different in experimental detail.NOTE 2: Two procedures for correcting for cells opened during specimen preparation are described in Appendix X1.1.1.5 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.

定价： 590元 / 折扣价： 502 元 加购物车

5.1 Knowledge of extractives from flexible barrier materials may serve many useful purposes. A test cell constructed as described in this practice may be used for obtaining such data. Another test cell has been found equivalent to the one described in this practice. See the appendix for the source of the alternate cell.5.2 United States Federal Regulations 21CFR 176.170 (d)(3), 21CFR 177.1330 (e)(4), 21CFR 177.1360 (b), 21CFR 177.1670 (b), and 21CFR Appendix VI (b) cite this standard practice as the basis for determining the amount of extractables from the surface of a package or multilayer film or modified paper in contact with food. In some cases, it is the only practice defined for this purpose. No alternative detail is given in the regulations for conducting extractions.5.3 Test Method D4754 is not an equivalent to this test method. It is for two-sided extraction of films having the same material on both of the exposed surfaces of the film.1.1 This practice covers the construction of test cells which may be used for the extraction of components from flexible barrier materials by suitable extracting liquids, including foods and food simulating solvents.1.2 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.1.3 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.

定价： 590元 / 折扣价： 502 元 加购物车

定价： 590元 / 折扣价： 502 元 加购物车

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.

定价： 590元 / 折扣价： 502 元 加购物车

5.1 Several physical properties of rigid cellular plastics are dependent on cell size and cell orientation. Measuring water absorption and open-cell content in accordance with Test Method D2842 and Test Method D6226 requires knowledge of surface cell volume, which uses cell size values in the calculations.5.2 This test method provides an apparent cell size because it assumes that there is no measurable edge to edge or top to bottom variation in average cell size and that the cell size distribution about the average cell size is normal. If the analyst is concerned there may be significant variation in either the average cell size or the cell size distribution more detailed analysis may be required.5.3 Before proceeding with this test method, reference should be made to the specification of the material being tested. Any test specimen preparation, conditioning, dimensions, or testing parameters, or a combination thereof, covered in the materials specification shall take precedence over those mentioned in this test method. If there are no material specifications, then the default conditions apply.FIG. 1 Razor Blade Cell Size Specimen SlicerFIG. 2 Cell Size Scale Slide Assembly1.1 This test method covers the determination of the apparent cell size of rigid cellular plastics by counting the number of cell-wall intersections in a specified distance.1.2 Procedure A requires the preparation of a thin slice, not more than one half the average cell diameter in thickness, that is mechanically stable. For most rigid cellular plastics this limits the test method to materials with an average cell size of at least 0.2 mm.1.3 Procedure B is intended for use with materials whose friable nature makes it difficult to obtain a thin slice for viewing.1.4 The values stated in SI units are to be regarded as 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.NOTE 1: The annex to ISO 2896 is technically equivalent to this test method.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.

定价： 590元 / 折扣价： 502 元 加购物车

This practice covers the procedures used for detection of mycoplasma contamination of cell cultures by growth on agarose medium. This practice does not cover identification of mycoplasma and indirect methods for detection of mycoplasma. This practice will not detect cultivar strains of Mycoplasma hyorhinis nor intended for use in detection of mycoplasma contamination in sera, culture media, vaccines, or other systems. The practice involves DM-1 solid medium preparation, quality control, and mycoplasma isolation.1.1 This practice covers the procedures used for detection of mycoplasma contamination by direct microbiological culture.1.2 This practice does not cover indirect methods for detection of mycoplasma such as DNA staining, biochemical detection, or genetic probes.1.3 This practice does not cover methods for identification of mycoplasma organisms.1.4 This practice will not detect cultivar strains (1) of Mycoplasma hyorhinis.1.5 This practice is not intended for use in detection of mycoplasma contamination in sera, culture media, vaccines, or other systems.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： 0元 / 折扣价： 0 元

Mycoplasma hyorhinis, cultivar α strains (1)3 do not grow on any of the standard media used for mycoplasma cultivation. These strains, which are found as contaminants in cell cultures, are detected by indirect methods.A specialized medium has been described but it is not yet in wide use (2).This practice should be used in conjunction with Practice E 1531.All cell cultures to be examined for mycoplasma should undergo a minimum of two passages in antibiototic-free tissue culture medium before testing.1.1 This practice covers the use of cell cultures and DNA-binding flurorochrome techniques to detect mycoplasma contamination of cell cultures.1.2 This practice does not cover axenic cultivation or identification of mycoplasmas.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： 0元 / 折扣价： 0 元

定价： 646元 / 折扣价： 550 元 加购物车