定价： 590元 / 折扣价： 502 元 加购物车

5.1 Excessive levels of hydrogen sulfide in the vapor phase above residual fuel oils in storage tanks can result in health hazards, violation of local occupational health and safety regulations, and public complaint. An additional concern is corrosion that can be caused by the presence of H2S during refining or other activities. Control measures to maintain safe levels of H2S require a precise method for the measurement of potentially hazardous levels of H2S in fuel oils. (Warning—Safety. Hydrogen sulfide (H2S) is a very dangerous, toxic, explosive and flammable, colorless and transparent gas which can be found in crude oil and can be formed during the manufacture of the fuel at the refinery and can be released during handling, storage, and distribution. At very low concentrations, the gas has the characteristic smell of rotten eggs. However, at higher concentrations, it causes a loss of smell, headaches, and dizziness, and at very high concentrations, it causes instantaneous death. It is strongly recommended that personnel involved in the testing for hydrogen sulfide are aware of the hazards of vapor-phase H2S and have in place appropriate processes and procedures to manage the risk of exposure.)5.2 This test method was developed so refiners, fuel terminal operators, and independent testing laboratory personnel can rapidly and precisely measure the amount of H2S in residual fuel oils and distillate blend stocks, with a minimum of training, in a wide range of locations.5.3 Test Method D5705 provides a simple and consistent field test method for the rapid determination of H2S in the residual fuel oils vapor phase. However it does not necessarily simulate the vapor phase H2S concentration of a fuel storage tank nor does it provide any indication of the liquid phase H2S concentration.5.4 Test Method D6021 does measure the H2S concentration of H2S in the liquid phase, however it requires a laboratory and a skilled operator to perform the complex procedure and calculations, and does not offer any reproducibility data. This test method (D7621) offers a 15 min automated test, simplicity, full precision, and a degree of portability.5.5 H2S concentrations in the liquid and vapor phase attempt to reach equilibrium in a static system. However, this equilibrium and the related liquid and vapor concentrations can vary greatly depending on temperature and the chemical composition of the liquid phase. The equilibrium of the vapor phase is disrupted the moment a vent or access point is opened to collect a sample.1.1 This test method covers procedures (A and B) for the determination of the hydrogen sulfide (H2S) content of fuel oils such as marine residual fuels and blend stocks, with viscosity up to 3000 mm2s-1 at 50 °C, and marine distillate fuels, as measured in the liquid phase.NOTE 1: Specification fuels falling within the scope of this test method are: ASTM Specification D396, MIL-DTL-16884, and ISO 8217.1.2 Procedure A has been shown to eliminate interferences such as thiols (mercaptans) and alkyl sulfides. Procedure B can give elevated results if such interferences are present (see Annex A2).NOTE 2: A procedure for measuring the amount of hydrogen sulfide in crude oil can be found in Appendix X1. Full precision for Appendix X1 has not yet been determined.1.3 Valid ranges for the precision are given in Table 2 and Table 3. Measurements can be made outside these ranges however precision has not been determined.1.4 Samples containing FAME do not affect the measurement of hydrogen sulfide by this test method.1.5 The values stated in SI units are to be regarded as standard. Non-SI units given in parentheses are for information only.1.6 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.1.7 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： 646元 / 折扣价： 550 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

定价： 590元 / 折扣价： 502 元 加购物车

5.1 This method directly determines the concentrations of dissolved PAH concentrations in environmental sediment pore water samples. The method is important from an environmental regulatory perspective because it can achieve the analytical sensitivities to meet the goals of the USEPA narcosis model for protecting benthic organisms in PAH contaminated sediments. Regulatory methods using solvent extraction have not achieved the wide calibration ranges from nanograms to milligrams per litre and the required levels of detection in the nanogram-per-litre range. In addition, conventional solvent extraction methods require large aliquot volumes (litre or larger), use of large volumes of organic solvents, and filtration to generate the pore water. This approach entails the storage and processing of large volumes of sediment samples and loss of low molecular weight PAHs in the filtration and solvent evaporation steps.5.2 This method can be used to determine nanogram to milligram per litre PAH concentrations in pore water. Small volumes of pore water are required for SPME extraction, only 1.5 mL per determination and virtually no solvent extraction waste is generated.1.1 The U.S. Environmental Protection Agency (USEPA) narcosis model for benthic organisms in sediments contaminated with polycyclic aromatic hydrocarbons (PAHs) is based on the concentrations of dissolved PAHs in the interstitial water or “pore water” in sediment. This test method covers the separation of pore water from PAH-impacted sediment samples, the removal of colloids, and the subsequent measurement of dissolved concentrations of the required 10 parent PAHs and 14 groups of alkylated daughter PAHs in the pore water samples. The “24 PAHs” are determined using solid-phase microextraction (SPME) followed by Gas Chromatography/Mass Spectrometry (GC/MS) analysis in selected ion monitoring (SIM) mode. Isotopically labeled analogs of the target compounds are introduced prior to the extraction, and are used as quantification references.1.2 Lower molecular weight PAHs are more water soluble than higher molecular weight PAHs. Therefore, USEPA-regulated PAH concentrations in pore water samples vary widely due to differing saturation water solubilities that range from 0.2 µg/L for indeno[1,2,3-cd]pyrene to 31 000 µg/L for naphthalene. This method can accommodate the measurement of microgram per litre concentrations for low molecular weight PAHs and nanogram per litre concentrations for high molecular weight PAHs.1.3 The USEPA narcosis model predicts toxicity to benthic organisms if the sum of the toxic units (ΣTUc) calculated for all “34 PAHs” measured in a pore water sample is greater than or equal to 1. For this reason, the performance limit required for the individual PAH measurements was defined as the concentration of an individual PAH that would yield 1/34 of a toxic unit (TU). However, the focus of this method is the 10 parent PAHs and 14 groups of alkylated PAHs (Table 1) that contribute 95 % of the toxic units based on the analysis of 120 background and impacted sediment pore water samples.3 The primary reasons for eliminating the rest of the 5-6 ring parent PAHs are: (1) these PAHs contribute insignificantly to the pore water TU, and (2) these PAHs exhibit extremely low saturation solubilities that will make the detection of these compounds difficult in pore water. This method can achieve the required detection limits, which range from approximately 0.01 µg/L, for high molecular weight PAHs, to approximately 3 µg/L for low molecular weight PAHs.1.4 The test method may also be applied to the determination of additional PAH compounds (for example, 5- and 6-ring PAHs as described in Hawthorne et al.).4 However, it is the responsibility of the user of this standard to establish the validity of the test method for the determination of PAHs other than those referenced in 1.1 and Table 1.1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.6 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. For specific hazard statements, refer to Section 9.1.7 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

The threshold temperature measured by this test method is an indication of the thermal instability of a chemical or mixture of chemicals, qualitatively expressed by the temperature rise. There is a potential hazard whenever the temperature of the chemical exceeds the threshold temperature unless proper design safeguards are utilized. This does not imply that temperatures lower than the threshold temperature are safe. Since this test is not an adiabatic type and does not indicate the effect of mass or time, other testing would be needed to characterize the use or storage of the chemical at lower temperatures.Because of rate and mass dependent factors, failure to find evidence of an exothermic reaction does not ensure thermal stability unless substantiated by other test methods.1.1 This test method is designed to determine the temperature at which a chemical or mixture of chemicals, confined initially as a solid or liquid in air or other controlled atmosphere under normal laboratory conditions, will start a reaction, generating appreciable heat when subjected to a programmed temperature increase. This test method is also designed to measure the magnitude and rate of heat generation.1.2 This test method is for use with condensed phases.1.3 This test method can be used over a temperature range from 0 to 500oC, and a pressure range of 0 to 5000 psi.1.4 As with any thermal stability test, proper safety precautions should be instituted to protect personnel. See also Section 6.1.5 Limitations1.5.1 The threshold temperature determined by this method may be higher than one determined by heating at a lesser rate.1.5.2 Samples of the same material having different thermal histories may have different threshold temperatures.1.6 This standard may involve hazardous materials, operations, and equipment. This standard does not purport to address all of the safety problems 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

The SCCW may be present in the workplace atmosphere where these materials are manufactured, processed, transported, or used. This test method can be used to monitor airborne concentrations of fibers in these environments. It may be employed as part of a personal or area monitoring strategy.This test method is based on dimensional considerations only. As such, it does not provide a positive identification of the fibers counted. Analysis by SEM or TEM is required when additional fiber identification information is needed.Note 1—This test method assumes that the analyst is familiar with the operation of PCM instrumentation and the interpretation of data obtained using this technique.This test method is not appropriate for measurement of fibers with diameters less than approximately 0.25 μm due to visibility limitations associated with PCM. The SEM or TEM methods may be used to provide additional size information of SCCW if needed (refer to Practice D6058 for additional information on the use of these methods).Results from the use of this test method shall be reported along with 95 % confidence limits for the samples being studied. Individual laboratories shall determine their intralaboratory coefficient of variation and use it for reporting 95 % confidence limits (1,3,4).1.1 This test method covers the sampling methods and analysis techniques used to assess the airborne concentration of single-crystal ceramic whiskers (SCCW), such as silicon carbide and silicon nitride, which may occur in and around the workplace where these materials are manufactured, processed, transported, or used. This test method is based on the collection of fibers by filtration of a known quantity of air through a filter. The filter is subsequently evaluated with a phase contrast microscope (PCM) for the number of fibers meeting appropriately selected counting criteria. This test method cannot distinguish among different types of fibers. This test method may be appropriate for other man-made mineral fibers (MMMF).1.2 This test method is applicable to the quantitation of fibers on a collection filter that are greater than 5 μm in length, less than 3 μm in width, and have an aspect ratio equal to or greater than 5:1. The data are directly convertible to a statement of concentration per unit volume of air sampled. This test method is limited by the diameter of the fibers visible by PCM (typically greater than 0.25 μm in width) and the amount and type of coincident interference particles.1.3 A more definitive analysis may be necessary to confirm the identity and dimensions of the fibers located with the PCM, especially where other fiber types may be present. Such techniques may include scanning electron microscopy (SEM) or transmission electron microscopy (TEM). The use of these test methods for the identification and size determination of SCCW is described in Practice D6058 and Test Methods D6059 and D6056.1.4 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 and health practices and determine the applicability of regulatory limitations prior to use.

定价： 0元 / 折扣价： 0 元

定价： 918元 / 折扣价： 781 元 加购物车

5.1 This practice increases the level of communication, provides an organized approach to cost control during the design of a project, and also provides a means of identifying extraordinary cost items and changes in assumptions between estimates.5.2 The users of this practice include owners, developers, contractors, cost professionals, estimators, architects, engineers, specification writers, quantity surveyors, and anyone charged with the responsibility of successfully managing the design of a building and its related site work within a specified project budget.5.3 Use this reporting format during the following:5.3.1 Contracting for design cost analysis services,5.3.2 Comparing the current design costs to a previous estimate, and5.3.3 Responding to each design phase.5.4 This practice provides a tool for analyzing design options and examining strategies to maintain the project budget.1.1 This practice covers an arranged method for providing cost analysis during the design phase of a building project.1.2 The use of this practice increases the level of communication between the design professional, owner, and the cost professional providing the cost consulting services.1.3 The practice establishes a structured method to support design decisions.1.4 The practice provides design and cost professionals with a framework for historically tabulating information to be used on relevant future projects.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： 515元 / 折扣价： 438 元 加购物车

定价： 983元 / 折扣价： 836 元 加购物车

3.1 Calcium phosphate coatings have been shown in animal and clinical studies to be biocompatible and to enhance the early attachment of bone to implant surfaces (see Refs. (1-5)).33.2 It is believed that the form of calcium phosphate ceramic and its purity with respect to secondary crystalline phases and amorphous material have an effect on its physical, mechanical, and biological properties. However, no definitive studies of effects on biological properties have been completed. To achieve reproducible clinical results and to permit the determination of the effects of properties of the coating on biological performance, it is essential that the properties of both clinical and experimental materials be well-characterized and consistent.3.3 This practice provides procedures for determination of the percentage by weight of the crystalline phases identified as hydroxyapatite, β-TCP, and CaO in plasma-sprayed hydroxyapatite coatings.1.1 This practice is for the determination, by the Reference Intensity Ratio External Standard Method, of the percent by weight of the crystalline phases, hydroxyapatite (HA), beta-(whitlockite) tricalcium phosphate (β-TCP), and calcium oxide (CaO) in coatings deposited upon metallic substrates by plasma spraying hydroxyapatite.1.2 A major component in plasma-sprayed HA coatings other than HA is expected to be amorphous calcium phosphate (ACP). Crystalline components other than HA that may be present include alpha- and beta- (whitlockite) tricalcium phosphates, tetracalcium phosphate (TTCP), calcium oxide, and calcium pyrophosphates. Quantification of the minor crystalline components has proven to be very unreliable due to extreme overlap and confounding of X-ray diffraction peaks. Therefore, this practice addresses the quantification of only HA, β-TCP, and CaO.1.3 This practice was developed for plasma-sprayed HA coatings with HA contents of at least 50 % of the total coating. It is recognized that the analysis of the crystalline components uses diffraction from regions of the pattern that also include a small contribution from the amorphous component. However, within the limits of applicability of this practice, the effect of such interference is believed to be negligible.1.4 The coating analyzed shall be produced and processed under manufacturing conditions equivalent to those used on the device of interest.1.5 This practice requires the use of monochromated copper Kα radiation and flat samples.1.6 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.7 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.1.8 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： 515元 / 折扣价： 438 元 加购物车

This specification covers the test methods and corresponding requirements for phase change-type disposable (for one time use only) clinical thermometers used for the intermittent determination of human temperature. When examined using the test methods suggested herein, sampled specimens shall comply with the specified requirements as to temperature range and graduation, accuracy, measurement retention, operating environment, storage environment, toxicity, workmanship, stability, and marking and labeling.1.1 This specification covers phase change-type clinical thermometers that are designed and intended for one-time use.1.2 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： 515元 / 折扣价： 438 元 加购物车