定价： 1333元 / 折扣价： 1134 元

定价： 1515元 / 折扣价： 1288 元 加购物车

定价： 78元 / 折扣价： 67 元 加购物车

定价： 0元 / 折扣价： 0 元 加购物车

定价： 0元 / 折扣价： 0 元 加购物车

定价： 0元 / 折扣价： 0 元 加购物车

定价： 689元 / 折扣价： 586 元 加购物车

定价： 689元 / 折扣价： 586 元 加购物车

5.1 This guide provides a protocol for detecting, characterizing, and quantifying nucleic acids (that is, DNA) of living and recently dead microorganisms in fuels and fuel-associated waters by means of a culture independent qPCR procedure. Microbial contamination is inferred when elevated DNA levels are detected in comparison to the expected background DNA level of a clean fuel and fuel system.5.2 A sequence of protocol steps is required for successful qPCR testing.5.2.1 Quantitative detection of microorganisms depends on the DNA-extraction protocol and selection of appropriate oligonucleotide primers.5.2.2 The preferred DNA extraction protocol depends on the type of microorganism present in the sample and potential impurities that could interfere with the subsequent qPCR reaction.5.2.3 Primers vary in their specificity. Some 16S and 18S RNA gene regions present in the DNA of prokaryotic and eukaryotic microorganisms appear to have been conserved throughout evolution and thus provide a reliable and repeatable target for gene amplification and detection. Amplicons targeting these conserved nucleotide sequences are useful for quantifying total population densities. Other target DNA regions are specific to a metabolic class (for example, sulfate reducing bacteria) or individual taxon (for example, the bacterial species Pseudomonas aeruginosa). Primers targeting these unique nucleotide sequences are useful for detecting and quantifying specific microbes or groups of microbes known to be associated with biodeterioration.5.3 Just as the quantification of microorganisms using microbial growth media employs standardized formulations of growth conditions enabling the meaningful comparison of data from different laboratories (Practice D6974), this guide seeks to provide standardization to detect, characterize, and quantify nucleic acids associated with living and recently dead microorganisms in fuel-associated samples using qPCR.NOTE 3: Many primers, and primer and probe combinations that are not covered in this guide may be used to perform qPCR. This guide does not attempt to cover all of the possible qPCR assays and does not suggest nor imply that the qPCR assays (that is, combinations of primers and probes, and reaction conditions) discussed here are better suited for qPCR than other qPCR assays not presented here. Additional, primers, primers and probes combination, and qPCR assay conditions may be added in the future to this guide as they become available to the ASTM scientific community. Guide D6469 reviews the types of damage that uncontrolled microbial growth in fuels and fuel systems can cause.5.4 Culture-based microbiological tests depend on the ability of microbes to proliferate in liquid, solid or semisolid nutrient media, in order for microbes in a sample to be detected.5.5 There is general consensus among microbiologists that only a fraction of the microbes believed to be present in the environment have been cultured successfully.5.6 Since the mid-1990s, genetic test methods that do not rely on cultivation have been increasingly favored for the detection and quantification of microorganisms in environmental samples.5.7 qPCR is a quantitative, culture-independent method that is currently used in the medical, food, and cosmetic industries for the detection and quantification of microorganisms.5.8 Since the early 2000s, qPCR methodology has evolved and is now frequently used to quantify microorganisms in fuel-associated samples, but there is currently no standardized methodology for employing qPCR for this application (1-6).3 The purpose of this guide is to provide guidance and standardization for genetic testing of samples using qPCR to quantify total microbial populations present in fuel-associated samples.5.9 Although this guide focuses on describing recommended protocols for the quantification of total microorganisms present in fuel-associated samples using qPCR, the procedures described here can also be applied to the standardization of qPCR assays for other genetic targets and environmental matrices.5.10 Genetic techniques have great flexibility so that it is possible to design a nearly infinite number of methods to detect and quantify each and every gene. Because of this flexibility of genetic techniques, it is important to provide a standard protocol for qPCR so that data generated by different laboratories can be compared.5.11 This guide provides recommendations for primers sequences and experimental methodology for qPCR assays for the quantification of total microorganisms present in fuel-associated samples.1.1 This guide covers procedures for using quantitative polymerase chain reaction (qPCR), a genomic tool, to detect, characterize and quantify nucleic acids associated with microbial DNA present in liquid fuels and fuel-associated water samples.1.1.1 Water samples that may be used in testing include, but are not limited to, water associated with crude oil or liquid fuels in storage tanks, fuel tanks, or pipelines.1.1.2 While the intent of this guide is to focus on the analysis of fuel-associated samples, the procedures described here are also relevant to the analysis of water used in hydrotesting of pipes and equipment, water injected into geological formations to maintain pressure and/or facilitate the recovery of hydrocarbons in oil and gas recovery, water co-produced during the production of oil and gas, water in fire protection sprinkler systems, potable water, industrial process water, and wastewater.1.1.3 To test a fuel sample, the live and recently dead microorganisms must be separated from the fuel phase which can include any DNA fragments by using one of various methods such as filtration or any other microbial capturing methods.1.1.4 Some of the protocol steps are universally required and are indicated by the use of the word must. Other protocol steps are testing-objective dependent. At those process steps, options are offered and the basis for choosing among them are explained.1.2 The guide describes the application of quantitative polymerase chain reaction (qPCR) technology to determine total bioburden or total microbial population present in fuel-associated samples using universal primers that allow for the quantification of 16S and 18S ribosomal RNA genes that are present in all prokaryotes (that is, bacteria and archaea) and eucaryotes (that is, mold and yeast collectively termed fungi), respectively.1.3 This guide describes laboratory protocols. As described in Practice D7464, the qualitative and quantitative relationship between the laboratory results and actual microbial communities in the systems from which samples are collected is affected by the time delay and handling conditions between the time of sampling and time that testing is initiated.1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard with the exception of the concept unit of gene copies/mL (that is, 16S or 18S gene copies/mL) to indicate the starting concentration of microbial DNA for the intended microbial targets (that is, bacteria, archaea, fungi).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 This procedure describes a rapid and sensitive method for estimating the stability reserve of an oil. The stability reserve is estimated in terms of a separability number, where a low value of the separability number indicates that there is a stability reserve within the oil. When the separability number is between 0 to 5, the oil can be considered to have a high stability reserve and asphaltenes are not likely to flocculate. If the separability number is between 5 to 10, the stability reserve in the oil will be much lower. However, asphaltenes are, in this case, not likely to flocculate as long as the oil is not exposed to any worse conditions, such as storing, aging, and heating. If the separability number is above 10, the stability reserve of the oil is very low and asphaltenes will easily flocculate, or have already started to flocculate.5.2 This test method can be used by refiners and users of heavy oils, for which this test method is applicable, to estimate the stability reserves of their oils. Hence, this test method can be used by refineries to control and optimize their refinery processes. Consumers of oils can use this test method to estimate the stability reserve of their oils before, during, and after storage.5.3 This test method is not intended for predicting whether oils are compatible before mixing, but can be used for determining the separability number of already blended oils. However, experience shows that oils exhibiting a low separability number are more likely to be compatible with other oils than are oils with high separability numbers.1.1 This test method covers the quantitative measurement, either in the laboratory or in the field, of how easily asphaltene-containing heavy fuel oils diluted in toluene phase separate upon addition of heptane. The result is a separability number (%). See also Test Method D7061.1.2 The test method is limited to asphaltene-containing heavy fuel oils. ASTM specification fuels that generally fall within the scope of this test method are Specification D396, Grade Nos. 4, 5, and 6, Specification D975, Grade No. 4-D, and Specification D2880, Grade Nos. 3-GT and 4-GT. Refinery fractions from which such blended fuels are made also fall within the scope of this test method.1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this 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.

定价： 702元 / 折扣价： 597 元 加购物车

4.1 This specification provides designers of general aviation aeroplanes a process for evaluating and testing a fuel system under hot weather conditions to ensure safety during flight. The specification is applicable to kerosene-type turbine engine fuels and fuel systems for traditional general aviation aeroplanes.1.1 This standard practice provides requirements for performing hot weather testing as a means of compliance to Subsection 7.7 of Specification F3063/F3063M for kerosene-type turbine fuels such as Jet A and Jet A-1 (Specification D1655). The appendix provides supplemental information and considerations for turbine fuel system hot weather operation. The material was developed through open consensus of international experts in general aviation.1.2 An applicant intending to propose this information as Means of Compliance for a design approval must seek guidance from their respective oversight authority (for example, published guidance from applicable civil aviation authorities (CAAs)) concerning the acceptable use and application thereof. For information on which oversight authorities have accepted this standard (in whole or in part) as an acceptable Means of Compliance to their regulatory requirements hereinafter (“the Rules”), refer to the ASTM Committee F44 web page (www.astm.org/COMMITTEE/F44.htm).1.3 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system are not necessarily exact equivalents; therefore, to ensure conformance with the standard, each system shall be used independently of the other, and values from the two systems shall not be combined.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. A specific warning is given in Section 6 on Test Setup.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

18.1 For purpose of determining compliance with the specified limits for requirements of the properties listed in Table 5, an observed value or calculated value shall be rounded as indicated in accordance with the rounding method of Practice E29.1.1 This specification establishes the requirements for Type GAS seamless Copper UNS No. C12200 tube for use in above ground natural gas and liquified petroleum (LP) gas fuel distribution systems, commonly assembled with flared fittings or brazed joints.NOTE 1: Tube temper, size, and joining method are determined by installation code requirements.1.2 Units—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 The following safety hazard caveat pertains only to the test method(s) portion, Section 17, 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.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

5.1 Residual fuel oils can contain H2S in the liquid phase and this can result in hazardous vapor phase levels of H2S in storage tank headspaces. The vapor phase levels can vary significantly according to the headspace volume, fuel temperature and agitation. Measurement of H2S levels in the liquid phase provides a useful indication of the residual fuel oil’s propensity to form high vapor phase levels, and lower levels in the residual fuel oil will directly reduce risk of H2S exposure. It is critical, however, that anyone involved in handling fuel oil, such as vessel owners and operators, continue to maintain appropriate safety practices designed to protect the crew, tank farm operators and others who can be exposed to H2S.5.1.1 The measurement of H2S in the liquid phase is appropriate for product quality control, while the measurement of H2S in the vapor phase is appropriate for health and safety purposes.5.2 This test method was developed to provide refineries, fuel terminals and independent testing laboratories, which do not have access to analytical instruments such as a gas chromatograph, with a simple and consistent field test method for the rapid determination of H2S in the vapor phase above residual fuel oils.NOTE 1: D5705 is one of three test methods for quantitatively measuring H2S in residual fuels:1) Test Method D6021 is an analytical test method to determine H2S levels in the liquid phase.2) Test Method D7621 is a rapid test method to determine H2S levels in the liquid phase.NOTE 2: Because of the reactivity, absorptivity and volatility of H2S, any measurement method only provides an H2S concentration at a given moment in time.5.3 This test method does not necessarily simulate the vapor phase H2S concentration in a fuel storage tank. It does, however, provide a level of consistency so that the test result is only a function of the residual fuel oil sample and not the test method, operator, or location. No general correlation can be established between this field test and actual vapor phase concentrations of H2S in residual fuel oil storage or transports. However, a facility that produces fuel oil from the same crude source under essentially constant conditions might be able to develop a correlation for its individual case.1.1 This test method covers the field determination of hydrogen sulfide (H2S) in the vapor phase (equilibrium headspace) of a residual fuel oil sample.1.2 The test method is applicable to liquids with a viscosity range of 5.5 mm2/s at 40 °C to 50 mm2/s at 100 °C. The test method is applicable to fuels conforming to Specification D396 Grade Nos. 4, 5 (Heavy), and 6.1.3 The applicable range is from 5 μmol/mol to 4000 μmol/mol (micromoles per mole) (5 ppm v/v to 4000 ppm v/v (parts per million by volume)).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.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 specification establishes recognized requirements for determining the child resistance of portable gasoline containers intended for use by consumers. The following tests shall be performed: senior adult test; child-resistant test (test subject/selection criteria); child-resistant tests (test failures); sequential test; and senior adult use effectiveness to conform with the specified requirements.1.1 This specification establishes recognized requirements for determining the child resistance of portable fuel containers (PFCs) and other types of portable containers intended for use by consumers to hold, store, and transport liquid fuels such as gasoline, kerosene, and diesel.1.1.1 “Portable Fuel Container” is defined in Specification F852 and includes the receptacle for gasoline, kerosene, or diesel fuel as well as spouts, caps, and other closure mechanisms and components for use with or on portable gasoline, kerosene, or diesel receptacles.1.1.2 This specification is also applicable to spouts, caps, or other closure mechanisms sold separately for use with or on a fuel container.1.1.3 This specification does not cover one-time use portable emergency fuel containers conforming to Specification F2874.1.2 This standard addresses the effectiveness of the child resistance (CR) device only after closure cycling, but does not address closure effectiveness:1.2.1 When at high or low temperatures,1.2.2 After thermal aging of polymers,1.2.3 After exposure to sunlight,1.2.4 After exposure to intended fuels, and1.2.5 After physical abuses, such as drops or impacts.NOTE 1: Please see Appendix X2 for additional information on these exemptions.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.

定价： 590元 / 折扣价： 502 元 加购物车

5.1 During engine operation, engine oil can become contaminated by water and fuel. In the case of Ed85 fuels, this contamination can result in a non-emulsified aqueous bottom layer in the oil that can affect the lubrication and detergency of the engine oil. To avoid field problems, engine oil should be capable of emulsifying water contamination to the extent that no aqueous presence appears.5.2 The test described in this method is designed to evaluate the ability of an engine oil, contaminated with a specified amount of water (volume fraction of 10 % of the original oil sample) and simulated Ed85 fuel (also a volume fraction of 10 % of the original oil sample), to emulsify the water after agitation in a blender and to maintain this emulsion at temperatures of 20 °C to 25 °C and –5 °C to 0 °C for at least 24 h.5.3 This test method has potential use in specifications of engine lubricating oils, such as Specification D4485.1.1 This test method describes a qualitative procedure to measure the ability of a specific volume of engine oil to emulsify a specific added volume of combined water and simulated Ed85 fuel upon agitation in a high-speed blender and to retain this emulsified state for at least 24 h at temperatures of both 20 °C to 25 °C and –5 °C to 0 °C.1.2 Information Letters are published periodically by the ASTM Test Monitoring Center (TMC) to update this and other test methods under the jurisdiction of Subcommittee D02.B0. Copies of these letters can be obtained by writing the Center.21.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this 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.

定价： 590元 / 折扣价： 502 元 加购物车