Improvised Long Test Lengths via Stitching Scale Bar Method:

Periodic performance evaluation is a critical issue for ensuring the reliability of data from terrestrial laser scanners (TLSs). With the recent introduction of the ASTM E3125-17 standard, there now exist standardized test procedures for this purpose. Point-to-point length measurement is one test method described in that documentary standard. This test is typically performed using a long scale bar (typically 2 m or longer) with spherical targets mounted on both ends. Long scale bars can become unwieldy and vary in length due to gravity loading, fixture forces, and environmental changes. In this paper, we propose a stitching scale bar (SSB) method in which a short scale bar (approximately 1 m or smaller) can provide a spatial length reference several times its length. The clear advantages of a short scale bar are that it can be calibrated in a laboratory and has potential long-term stability. An essential requirement when stitching a short scale bar is that the systematic errors in TLSs do not change significantly over short distances. We describe this requirement in this paper from both theoretical and experimental perspectives. Based on this SSB method, we evaluate the performance of a TLS according to the ASTM E3125-17 standard by stitching a 1.15 m scale bar to form a 2.3 m reference length. For comparison, a single 2.3 m scale bar is also employed for direct measurements without stitching. Experimental results show a maximum deviation of 0.072 mm in length errors between the two approaches, which is an order of magnitude smaller than typical accuracy specifications for TLSs.

Download Full-text

Reliability of Miniature Concrete Prism Test in Assessing Alkali-Silica Reactivity of Moderately Reactive Aggregates

Transportation Research Record Journal of the Transportation Research Board ◽

10.1177/0361198120912247 ◽

2020 ◽

Vol 2674 (4) ◽

pp. 23-29

Author(s):

Harish Konduru ◽

Prasad Rangaraju ◽

Omar Amer

Keyword(s):

False Positive ◽

Standardized Test ◽

False Negative ◽

Test Method ◽

Test Procedures ◽

Concrete Prism ◽

Coarse Aggregates ◽

Fine Aggregates ◽

Mortar Bar ◽

Concrete Prism Test

Alkali-silica reaction (ASR) is one of the most significant durability issues in concrete structures. Although there are a number of standardized test procedures to evaluate the aggregate reactivity, each method has its own drawbacks. Two of the most common tests that are employed widely are the accelerated mortar bar test (AMBT) (ASTM C1260) and the concrete prism test (CPT) (ASTM C1293). The major issue with the AMBT test is the number of false-positive results from this test associated with high test temperature, rendering the test method unreliable. CPT is one of the most reliable tests for assessing the potential for ASR, but its major disadvantage is the duration of the test involved, which takes one to two years. In this research, a novel test method called the miniature concrete prism test (MCPT) was developed and the effectiveness and reliability of the results assessed when compared with CPT and AMBT. Samples of 26 coarse aggregates and 16 fine aggregates with various reactivity levels were employed for the testing. The test results were compared for MCPT versus CPT, in which 23 out of 26 coarse aggregates and eight out of 16 fine aggregates either passed or failed in both MCPT and CPT. For MCPT versus AMBT, 16 out of 26 coarse aggregates and 13 out of 16 fine aggregates either passed or failed in both MCPT and AMBT. The sensitivity of false-negative and false-positive aggregate sources is discussed and explained briefly.

Download Full-text

Standardized Test Methods for Use in Waste Compliance Testing in the Department of Energy'S Waste Acceptance Process

MRS Proceedings ◽

10.1557/proc-84-483 ◽

1986 ◽

Vol 84 ◽

Cited By ~ 2

Author(s):

George B. Mellinger

Keyword(s):

Standardized Tests ◽

Standardized Test ◽

Test Methods ◽

Test Method ◽

Approval Process ◽

Test Procedures ◽

Compliance Testing ◽

American Society

Summary:Standardized test methods that are currently in use or under development appear to adequately cover most of the testing that may be required to demonstrate compliance with the WAPS. It may be important to complete standardization of those tests that are under development, and to develop additional standardized tests for those specifications for which no standardized tests exist. A significant amount of work would be involved in this effort. Therefore, before this effort is undertaken, DOE must decide whether there is a need for a set of standardized test methods that would receive an “official approval” for use in waste compliance testing. If a set of approved tests is needed, DOE would need to determine what types of tests to include in the “approved list”, who should develop these tests, and which organizations should review and approve the test methods. Test method review and approval might be accomplished through the use of the Materials Review Board (MRB), an organization that was created by DOE for the purpose of reviewing and approving key test methods and data related to the repository licensing process. Alternatively, other means of standardizing these tests might be considered, such as processing the tests through the American Society for Testing and Materials for publication as ASTM standards.If a set of approved tests is adopted, producers would not be required to use these tests; however, if a producer wished to propose other tests for compliance testing, it would be reasonable to require that such test procedures undergo a review/approval process similar to that which the officially approved tests had undergone. Once approved, these alternate procedures could be used for compliance testing.

Download Full-text

Comparing Test Methods for the Intra-ply Shear Properties of Uncured Prepreg Tapes

Science and Engineering of Composite Materials ◽

10.1515/secm-2020-0009 ◽

2020 ◽

Vol 27 (1) ◽

pp. 89-96

Author(s):

Klaus Heller ◽

Moritz Hallmannseder ◽

David Colin ◽

Kalle Kind ◽

Klaus Drechsler

Keyword(s):

Material Properties ◽

Deformation Behavior ◽

Standardized Test ◽

Test Methods ◽

Test Method ◽

Test Procedures ◽

Automated Fiber Placement ◽

Bar Test ◽

Torsion Bar ◽

Rheometer Test

AbstractTo achieve cost-efficient manufacturing and a high part quality in Thermoset Automated Fiber Placement (TS-AFP), knowledge about the interaction between material and process parameters is of special interest. Material properties of prepregs are well known at the cured state of the resin. However, there are no standardized test procedures for the mechanical behavior of the uncured prepreg tapes. To investigate the intra-ply shear deformation behavior of uncured unidirectional prepreg tapes, we compared several measurement procedures and conducted experiments for rheometer based tests using 8552/AS4 material. We identified a rotational parallel platens rheometer test method and a torsion bar rheometer test method to be suitable. Experiments using both methods revealed that the Torsion Bar Test has a higher repeatability and the analysis is less complex. Furthermore, first results show that changes in material properties caused by aging can be analyzed using this method. In the future,we will use the Torsion Bar Test to characterize changes in deformation behavior due to material aging as well as material modifications. By this, we will be able to provide data for the material modeling thus enabling the prediction of lay-up defects such as buckling due to steering.

Download Full-text

Laboratory Test to Evaluate the Resistance of Cementitious Materials to Biodeterioration in Sewer Network Conditions

Materials ◽

10.3390/ma14030686 ◽

2021 ◽

Vol 14 (3) ◽

pp. 686

Author(s):

Amr Aboulela ◽

Matthieu Peyre Lavigne ◽

Amaury Buvignier ◽

Marlène Fourré ◽

Maud Schiettekatte ◽

...

Keyword(s):

Calcium Aluminate ◽

Standardized Test ◽

Performance Indicator ◽

Cementitious Materials ◽

Test Method ◽

Sustainable Construction ◽

Public Health Issue ◽

Sulfur Source ◽

Test Protocol ◽

Wide Range

The biodeterioration of cementitious materials in sewer networks has become a major economic, ecological, and public health issue. Establishing a suitable standardized test is essential if sustainable construction materials are to be developed and qualified for sewerage environments. Since purely chemical tests are proven to not be representative of the actual deterioration phenomena in real sewer conditions, a biological test–named the Biogenic Acid Concrete (BAC) test–was developed at the University of Toulouse to reproduce the biological reactions involved in the process of concrete biodeterioration in sewers. The test consists in trickling a solution containing a safe reduced sulfur source onto the surface of cementitious substrates previously covered with a high diversity microbial consortium. In these conditions, a sulfur-oxidizing metabolism naturally develops in the biofilm and leads to the production of biogenic sulfuric acid on the surface of the material. The representativeness of the test in terms of deterioration mechanisms has been validated in previous studies. A wide range of cementitious materials have been exposed to the biodeterioration test during half a decade. On the basis of this large database and the expertise gained, the purpose of this paper is (i) to propose a simple and robust performance criterion for the test (standardized leached calcium as a function of sulfate produced by the biofilm), and (ii) to demonstrate the repeatability, reproducibility, and discriminability of the test method. In only a 3-month period, the test was able to highlight the differences in the performances of common cement-based materials (CEM I, CEM III, and CEM V) and special calcium aluminate cement (CAC) binders with different nature of aggregates (natural silica and synthetic calcium aluminate). The proposed performance indicator (relative standardized leached calcium) allowed the materials to be classified according to their resistance to biogenic acid attack in sewer conditions. The repeatability of the test was confirmed using three different specimens of the same material within the same experiment and the reproducibility of the results was demonstrated by standardizing the results using a reference material from 5 different test campaigns. Furthermore, developing post-testing processing and calculation methods constituted a first step toward a standardized test protocol.

Download Full-text

Validation of a new standardized test method for the freshwater amphipodHyalella azteca: Determining the chronic effects of silver in sediment

Environmental Toxicology and Chemistry ◽

10.1002/etc.3453 ◽

2016 ◽

Vol 35 (10) ◽

pp. 2430-2438 ◽

Cited By ~ 4

Author(s):

Lisa N. Taylor ◽

Lesley Novak ◽

Martina Rendas ◽

Paula M.C. Antunes ◽

Rick P. Scroggins

Keyword(s):

Standardized Test ◽

Test Method ◽

Chronic Effects

Download Full-text

Towards Standardising SHPB Testing - A Round Robin Exercise

EPJ Web of Conferences ◽

10.1051/epjconf/201818302027 ◽

2018 ◽

Vol 183 ◽

pp. 02027

Author(s):

Reuben Govender ◽

Muhammad Kariem ◽

Dong Ruan ◽

Rafael Santiago ◽

Dong Wei Shu ◽

...

Keyword(s):

Split Hopkinson Pressure Bar ◽

Pure Copper ◽

Round Robin ◽

Standard Test ◽

Test Method ◽

Hopkinson Pressure Bar ◽

Test Procedures ◽

Draft Standard ◽

Shpb Test ◽

Pressure Bar

The Split Hopkinson Pressure Bar (SHPB) test, while widely utilised for high strain rate tests, has yet to be standardised. As an exploratory step towards developing a standard test method or protocol, a Round Robin test series has been conducted between four institutions: (i) Swinburne University of Technology, Australia (ii) University of São Paulo, Brazil, (iii) University of Cape Town, South African and (iv) Nanyang Technological University, Singapore. Each institution prepared specimens from a metallic material, and provided batches of specimens from their chosen material to the other institutions. The materials utilised in this round of testing were commercially pure copper and aluminium, magnesium alloy and stainless steel (316 grade). The intent of the first exercise is to establish the consistency of SHPB test results on nominally identical specimens at comparable elevated strain rates, conducted by different laboratories following notionally similar test procedures with some freedom in data processing. This paper presents and compares the results of the first batch of tests for copper, identifying variations between results from different laboratories. The variation between different laboratories’ results for copper is suffciently small that there is confidence in the potential to develop a draft standard in future.

Download Full-text

Soil and tissue tests to predict pasture yield responses to applications of potassium fertiliser in high-rainfall areas of south-western Australia

Australian Journal of Experimental Agriculture ◽

10.1071/ea01060 ◽

2002 ◽

Vol 42 (2) ◽

pp. 149 ◽

Cited By ~ 19

Author(s):

M. D. A. Bolland ◽

W. J. Cox ◽

B. J. Codling

Keyword(s):

Western Australia ◽

Field Experiments ◽

Relative Yield ◽

Subterranean Clover ◽

Test Method ◽

Yield Response ◽

Soil Test ◽

Test Procedures ◽

Pasture Production ◽

Yield Responses

Dairy and beef pastures in the high (>800 mm annual average) rainfall areas of south-western Australia, based on subterranean clover (Trifolium subterraneum) and annual ryegrass (Lolium rigidum), grow on acidic to neutral deep (>40 cm) sands, up to 40 cm sand over loam or clay, or where loam or clay occur at the surface. Potassium deficiency is common, particularly for the sandy soils, requiring regular applications of fertiliser potassium for profitable pasture production. A large study was undertaken to assess 6 soil-test procedures, and tissue testing of dried herbage, as predictors of when fertiliser potassium was required for these pastures. The 100 field experiments, each conducted for 1 year, measured dried-herbage production separately for clover and ryegrass in response to applied fertiliser potassium (potassium chloride). Significant (P<0.05) increases in yield to applied potassium (yield response) were obtained in 42 experiments for clover and 6 experiments for ryegrass, indicating that grass roots were more able to access potassium from the soil than clover roots. When percentage of the maximum (relative) yield was related to soil-test potassium values for the top 10 cm of soil, the best relationships were obtained for the exchangeable (1 mol/L NH4Cl) and Colwell (0.5 mol/L NaHCO3-extracted) soil-test procedures for potassium. Both procedures accounted for about 42% of the variation for clover, 15% for ryegrass, and 32% for clover + grass. The Colwell procedure for the top 10 cm of soil is now the standard soil-test method for potassium used in Western Australia. No increases in clover yields to applied potassium were obtained for Colwell potassium at >100 mg/kg soil. There was always a clover-yield increase to applied potassium for Colwell potassium at <30 mg/kg soil. Corresponding potassium concentrations for ryegrass were >50 and <30 mg/kg soil. At potassium concentrations 30–100 mg/kg soil for clover and 30–50 mg/kg soil for ryegrass, the Colwell procedure did not reliably predict yield response, because from nil to large yield responses to applied potassium occurred. The Colwell procedure appears to extract the most labile potassium in the soil, including soluble potassium in soil solution and potassium balancing negative charge sites on soil constituents. In some soils, Colwell potassium was low indicating deficiency, yet plant roots may have accessed potassum deeper in the soil profile. Where the Colwell procedure does not reliably predict soil potassium status, tissue testing may help. The relationship between relative yield and tissue-test potassium varied markedly for different harvests in each year of the experiments, and for different experiments. For clover, the concentration of potassium in dried herbage that was related to 90% of the maximum, potassium non-limiting yield (critical potassium) was at the concentration of about 15 g/kg dried herbage for plants up to 8 weeks old, and at <10 g/kg dried herbage for plants older than 10–12 weeks. For ryegrass, there were insufficient data to provide reliable estimates of critical potassium.

Download Full-text

New techniques for gap-filling and partitioning of H<sub>2</sub>O and CO<sub>2</sub> eddy fluxes measured over forests in complex mountainous terrain

10.5194/bg-2017-247 ◽

2017 ◽

Cited By ~ 1

Author(s):

Minseok Kang ◽

Joon Kim ◽

Bindu Malla Thakuri ◽

Junghwa Chun ◽

Chunho Cho

Keyword(s):

Environmental Changes ◽

Water Cycle ◽

Co2 Flux ◽

Test Method ◽

Co2 Fluxes ◽

Gap Filling ◽

New Techniques ◽

Diameter Increment ◽

Filling Method ◽

Rain Events

Abstract. The continuous measurement of H2O and CO2 fluxes using the eddy covariance (EC) technique is still challenging for forests in complex terrain because of large amounts of wet canopy evaporation (EWC), which occur during and following rain events when the EC systems rarely work correctly, and the horizontal advection of CO2 generated at night. We propose new techniques for gap-filling and partitioning of the H2O and CO2 fluxes: (1) a model-stats hybrid method (MSH) and (2) a modified moving point test method (MPTm). The former enables the recovery of the missing EWC in the traditional gap-filling method and the partitioning of the evapotranspiration (ET) into transpiration and (wet canopy) evaporation. The latter determines the friction velocity (u*) threshold based on an iterative approach using moving windows for both time and u*, thereby allowing not only the nighttime CO2 flux correction and partitioning but also the assessment of the significance of the CO2 drainage. We tested and validated these new methods using the datasets from two flux towers, which are located at forests in hilly and complex terrains. The MSH reasonably recovered the missing EWC of 16 ~ 41 mm year−1 and separated it from the ET (14 ~ 23 % of the annual ET). The MPTm produced consistent carbon budgets using those from the previous research and diameter increment, while it has improved applicability. Additionally, we illustrated certain advantages of the proposed techniques, which enables us to understand better how ET responses to environmental changes and how the water cycle is connected to the carbon cycle in a forest ecosystem.

Download Full-text

Aquatic testing guidelines insufficiently control the influence of dilution water toc and hardness on cationic polymer toxicity – A proposal to improve standardized test procedures

Chemosphere ◽

10.1016/j.chemosphere.2020.127473 ◽

2020 ◽

Vol 259 ◽

pp. 127473

Author(s):

Edward R. Salinas ◽

Jared S. Bozich ◽

Sara Kolbenschlag ◽

Miriam Kary-Heinrich ◽

Philipp W. Hopp ◽

...

Keyword(s):

Standardized Test ◽

Cationic Polymer ◽

Test Procedures ◽

Dilution Water

Download Full-text

Development of an in vitro test procedure for the characterization of left atrial appendage occluder devices

Current Directions in Biomedical Engineering ◽

10.1515/cdbme-2019-0116 ◽

2019 ◽

Vol 5 (1) ◽

pp. 461-463

Author(s):

Finja Borowski ◽

Sebastian Kaule ◽

Stefan Siewert ◽

Klaus-Peter Schmitz ◽

Michael Stiehm ◽

...

Keyword(s):

Left Atrial ◽

Left Atrial Appendage ◽

Standardized Test ◽

Test Procedure ◽

Test Method ◽

Atrial Appendage ◽

In Vitro Test ◽

Watchman Device ◽

Vitro Test

AbstractThe implantation of an occluder in the left atrial appendage (LAA) is an emerging therapy for the treatment of patients suffering from atrial fibrillation and with a contraindication to oral anticoagulation. The LAA occluder (LAAO) provides a reduction of the potential risk of strokes by thromboembolism. Currently, only a few CE-approved devices are available on the market and the number of clinical trials is comparatively low. Furthermore, there is currently no standardized test method available for testing functionality of the occluder, especially for testing safe anchorage and permeability. Therefore, the aim of this study is to establish an in vitro test method to prove anchorage mechanism and permeability regarding thromboembolism of the LAAO under physiological conditions. A standardized technical and fully parameterized silicone model of a LAA, based on studies of different morphologies and sizes, was developed. The LAA model was mounted onto the left atrial chamber of a commercial pulse duplicator system to simulate physiological hemodynamic conditions. The test was performed using the Watchman device (Boston Scientific, USA; size: 31 mm). The inner implantation diameter of the LAA model was designed according to a target compression of 10% for the Watchman device in the implanted configuration. Furthermore, thrombus-like particles (n=150, d=1,7±0,05 mm) were added to represent the flushing of thrombi out of the LAA after device implantation. Within several cycles it was confirmed that no particles were washed out of the LAA model with the implanted occluder leading to a full protection against thromboembolism. It could also be shown that the occluder is firmly anchored in the LAA. Pressure measurements with sensors in the left atrium and in the LAA distal to the occluder could also show that the occluder has no influence on the pressure conditions in the LAA.

Download Full-text