scholarly journals Assessment and investigation of measurement uncertainty of standard samples of substances and materials in physicochemical measurements based on standard test methods

2021 ◽  
Vol 2094 (5) ◽  
pp. 052011
Author(s):  
Sh M Masharipov ◽  
K R Ruzmatov ◽  
S A Rahmatullayev ◽  
F F Fattoyev ◽  
M M Mahmudjonov ◽  
...  
Keyword(s):  
Standard Sample ◽  
Reference Value ◽  
Test Methods ◽  
Standard Test ◽  
Pure Substance ◽  
Reference Level ◽  
Standard Samples ◽  
System Of Units ◽  
Pure Substances ◽  
Physicochemical Measurements

Abstract The article assessed and investigated the uncertainty of measurements of standard samples of substances and materials in physicochemical measurements based on standard test methods. A general approach to estimating the sources of uncertainty of standard samples is described. Uncertainties from heterogeneity of standard sample material. uncertainty from instability of standard sample characteristic values. uncertainty from method of setting reference value are investigated. Purity of substances is the main parameter that needs to be paid attention to when studying their properties. This is all the more important when it comes to using a pure substance as some approximation to the prototype reference value. since only this unit of seven main units in the International System of Units (SI system) does not have its own standard. In this sense. an important scientific task is the comprehensive study of pure substances for their practical use as benchmarks for comparison in metrological works and analytical research. The main and very important part of the measurement traceability system are materials with certified (certified) content of components and defined uncertainties of these values (standard samples of the approved type). which require pure substances certified at a higher - reference level. i.e. comparison standards.

scholarly journals An Intelligent Evaluation Method to Analyze the Competitiveness of Airlines

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Jun Zhao ◽  
Xumei Chen
Keyword(s):  
Neural Network ◽  
Prior Knowledge ◽  
Evaluation Method ◽  
Standard Sample ◽  
Reference Value ◽  
The Self ◽  
Index Data ◽  
Som Neural Network ◽  
Simulation Results ◽  
Self Organizing

An intelligent evaluation method is presented to analyze the competitiveness of airlines. From the perspective of safety, service, and normality, we establish the competitiveness indexes of traffic rights and the standard sample base. The self-organizing mapping (SOM) neural network is utilized to self-organize and self-learn the samples in the state of no supervision and prior knowledge. The training steps of high convergence speed and high clustering accuracy are determined based on the multistep setting. The typical airlines index data are utilized to verify the effect of the self-organizing mapping neural network on the airline competitiveness analysis. The simulation results show that the self-organizing mapping neural network can accurately and effectively classify and evaluate the competitiveness of airlines, and the results have important reference value for the allocation of traffic rights resources.

scholarly journals Comparison of Two Intergranular Corrosion Tests on EN AW-6016 Sheet Material

2021 ◽  
Vol 11 (11) ◽  
pp. 5294
Author(s):  
Peer Decker ◽  
Ines Zerbin ◽  
Luisa Marzoli ◽  
Marcel Rosefort
Keyword(s):  
Optical Microscopy ◽  
Intergranular Corrosion ◽  
Sheet Material ◽  
Test Methods ◽  
Standard Test ◽  
Corrosion Depth ◽  
Corrosion Tests ◽  
Automotive Company ◽  
Test Parameters

Two different intergranular corrosion tests were performed on EN AW-6016 sheet material, an ISO 11846:1995-based test with varying solution amounts and acid concentrations, and a standard test of an automotive company (PV1113, VW-Audi). The average intergranular corrosion depth was determined via optical microscopy. The differences in the intergranular corrosion depths were then discussed with regard to the applicability and quality of the two different test methods. The influence of varying test parameters for ISO 11846:1995 was discussed as well. The determined IGC depths were found to be strongly dependent on the testing parameters, which will therefore have a pronounced influence on the determined IGC susceptibility of a material. In general, ISO 11846:1995 tests resulted in a significantly lower corrosion speed, and the corrosive attack was found to be primarily along grain boundaries.

Correlation of Melting Results for Both Pure Substances and Impure Substances

1986 ◽  
Vol 108 (3) ◽  
pp. 649-653 ◽  
Author(s):  
E. M. Sparrow ◽  
G. A. Gurtcheff ◽  
T. A. Myrum
Keyword(s):  
Solid Phase ◽  
Equilibrium Phase ◽  
Equilibrium Phase Diagram ◽  
Vertical Tube ◽  
Step Change ◽  
Pure Substance ◽  
Characteristic Temperatures ◽  
Pure Substances ◽  
T Values ◽  
Melting Experiments

Melting experiments were performed encompassing both pure and impure substances. The pure substances included n-octadecane paraffin and n-eicosane paraffin, while the impure substances were mixtures synthesized from the pure paraffins. The experiments were carried out in a closed vertical tube whose wall was subjected to a step-change increase in temperature to initiate the melting. For each impure substance, supplementary measurements were made of two characteristic temperatures: the temperature T** at which melting of the solid phase first begins and the lowest temperature T* at which the melting can go to completion. For a pure substance, T** = T*. The time-dependent melting results for all the investigated substances, both pure and impure, were well correlated as a function of FoSte**(Gr**)1/8 alone, where the ** signifies the presence of T** in the temperature difference which appears in Ste and Gr. This correlation enables melting rates for impure substances to be determined from melting rates for pure substances. The T** values needed for the implementation of the correlation can be obtained from simple experiments, obviating the need for the complete equilibrium phase diagram.

Serviceability Assessment of a Printed Finish on T-Shirts

2021 ◽  
Vol 8 (2) ◽  
pp. 48-53
Author(s):  
Reannan Riedy ◽  
Meredith McQuerry
Keyword(s):  
Abrasion Resistance ◽  
Dimensional Change ◽  
Test Methods ◽  
Standard Test ◽  
Performance Expectations ◽  
Agricultural Worker ◽  
Soil Release ◽  
And Performance ◽  
Typical Consumer ◽  
Change Material

To improve the comfort of agricultural workers, a T-shirt with a printed active cooling finish was evaluated to determine if it would meet the wash life durability and performance expectations of such an arduous application. Six shirts with a printed phase change material (PCM) finish and six shirts without (control) were washed 50 times to replicate a typical consumer wash life. Shirts were evaluated for absorbency, dimensional change, colorfastness, crocking, abrasion resistance, soil release, and smoothness retention according to AATCC and ASTM standard test methods. Testing was conducted before laundering and after 1, 5, 10, 20, 30, 35, 40, 45, and 50 consumer laundry (CL) cycles. Absorbency and dimensional change were significantly influenced by the PCM finish. Results demonstrate the appropriateness of adopting such a finish technology for agricultural worker clothing applications.

Development of standard test methods for unmanned and manned industrial vehicles used near humans

2013 ◽  
Author(s):  
Roger Bostelman ◽  
Richard Norcross ◽  
Joe Falco ◽  
Jeremy Marvel
Keyword(s):  
Test Methods ◽  
Standard Test

Nondestructive Evaluation Method of Average Grain Size in TWIP Steel by Laser Ultrasonic

2018 ◽  
Vol 913 ◽  
pp. 324-330
Author(s):  
Yan Jie Zhang ◽  
Xiao Chen Wang ◽  
Quan Yang ◽  
Ren Jie Xue ◽  
An Min Yin
Keyword(s):  
Grain Size ◽  
Manufacturing Industry ◽  
Evaluation Method ◽  
High Efficiency ◽  
Standard Sample ◽  
Twip Steel ◽  
Test Sample ◽  
Standard Samples ◽  
Laser Ultrasonic ◽  
Average Grain Size

TWIP steel has the characteristics of high elongation and high tensile strength at room temperature, and therefore it is widely used in the automobile manufacturing industry. Since the grain size has a very important influence on its mechanical properties and corrosion resistance it is significant to study the average grain size of TWIP steel. In this experiment, the specimens were heated to 700~1000°C and preserved for one hour, and the recrystallized structures with different average grain sizes were obtained. All the samples were tested by laser ultrasonic experimental platform and the standard sample was selected. Then the attenuation coefficients of remaining samples were compared with the standard samples by conventional methods. The results showed that the larger the difference between the average grain size of the test sample and the standard sample is, the greater the error of the test will be. The new evaluation model was established by the improved method, and the prediction error was reduced to 5.44~11.61%, which proved the effectiveness of the new method. In addition, laser ultrasonic testing has the advantages of high efficiency and no damage compared with traditional methods.

scholarly journals Derived Interaction Parameters for the TSAI-WU Tensor Polynomial Theory of Strength for Composite Materials

2001 ◽  
Author(s):  
Steven J. DeTeresa ◽  
Gregory J. Larsen
Keyword(s):  
Hydrostatic Pressure ◽  
Fiber Composite ◽  
Strength Criterion ◽  
Test Methods ◽  
Standard Test ◽  
Transverse Compression ◽  
Strength Parameters ◽  
Carbon Fiber Composite ◽  
The Stability ◽  
Stability Limits

Abstract It is shown that the two interactive strength parameters in the Tsai-Wu tensor polynomial strength criterion for fiber composites can be derived in terms of the uniaxial or non-interacting strength parameters if the composite does not fail under practical levels of hydrostatic pressure or equal transverse compression. Thus the required number of parameters is reduced from seven to five and all five of the remaining strength terms are easily determined using standard test methods. The derived interactive parameters fall within the stability limits of the theory, yet they lead to open failure surfaces in the compressive stress quadrant. The assumptions used to derive the interactive parameters were supported by measurements for the effect of hydrostatic pressure and unequal transverse compression on the behavior of a typical carbon fiber composite.

scholarly journals The synergistic effect of borax and chlorinated paraffin as flame – retardants for epoxy and unsaturated polyester resins

2008 ◽  
Vol 5 (1) ◽  
pp. 131-136
Author(s):  
Baghdad Science Journal
Keyword(s):  
Synergistic Effect ◽  
Flame Retardants ◽  
Unsaturated Polyester ◽  
Test Methods ◽  
Standard Test ◽  
Good Effect ◽  
Polyester Resins ◽  
Unsaturated Polyester Resins ◽  
Flame Retardation ◽  
Chlorinated Paraffin

In this investigation , borax (B) (additive I) and chlorinated paraffin (CP.) (additive II) ,were used as flame retardants for each of epoxy and unsaturated polyester resins in the weight ratios of 2,4,6, & 8% by preparing films of (130×130×3) mm dimensions. Also films of these resins with a mixture of [50%(B.)+50%(CP.)] (additive III) in the same weight ratios were prepared in order to study the synergistic effect of these additives on the flammability of the two resins . Three standard test methods were used to measure the flame retardation which are : 1-ASTM : D-2863 2-ASTM : D-635 3-ASTM : D-3014 The results obtained from these tests indicated that the additives (B),(CP.) and their mixture , gave a good effect as flame retardants for each epoxy and unsaturated polyester resins , but their synergistic effect was more effective than each of them alone. Finally , the compatibility between the additives and resins (which showed a clear effect on retardation) was also studied .

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