scholarly journals Current Ice Adhesion Testing Methods and the Need for a Standard: A Concise Review

Standards ◽  
2021 ◽  
Vol 1 (2) ◽  
pp. 117-133
Author(s):  
Monika Bleszynski ◽  
Edward Clark
Keyword(s):  
Economic Losses ◽  
Ice Accretion ◽  
Testing Methods ◽  
Adhesion Testing ◽  
Standard Testing ◽  
Testing Method ◽  
Concise Review ◽  
Main Factors ◽  
Airplane Accidents ◽  
Ice Adhesion

Ice accretion is a serious problem in cold climates, causing automobile and airplane accidents, as well as severe economic losses throughout various sectors. To combat these issues, many solutions have been developed, such as de-icing materials, which can delay or prevent the adhesion of ice to a surface through chemical, temperature, or physical means. To effectively assess the properties of a de-icing material, ice adhesion testing must be conducted, of which there are numerous types, each with their own characteristics. Unfortunately, the same material, tested with different methods, may provide very different ice adhesion values. This makes it difficult to properly characterize a material’s de-icing properties and compare values across the literature. In this review, we identified the main ice adhesion testing methods and compared ice adhesion values for a particular material with different testing methods. We then discussed some of the main issues with current ice testing methods and identified some of the main factors that may affect ice adhesion values, namely ice quality and the use of a mold, which may significantly affect the final ice adhesion results. Finally, we proposed a new, simple standard testing method, in an attempt to eliminate some of the issues with current ice testing methods.

scholarly journals 9. Evaluation of Synergy Testing Methods for Clinical Labs to Determine Susceptibility of Extensively Drug-resistant Gram-negatives to Ceftazidime/ Avibactam and Aztreonam Combination Therapy

2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S5-S6
Author(s):  
Ayesha Khan ◽  
Samuel G Erickson ◽  
Cedric H Pettaway ◽  
Cesar A Arias ◽  
William R Miller ◽  
...  
Keyword(s):  
Combination Therapy ◽  
Clinical Decision Making ◽  
Research Study ◽  
Scientific Research ◽  
Major Error ◽  
Testing Methods ◽  
Research Support ◽  
Testing Method ◽  
Study Investigator ◽  
Synergy Testing

Abstract Background Carbapenem-resistant Enterobacterales (CRE) and Pseudomonas aeruginosa (CR-PA) producing Metallo-β-lactamases (MBLs) cause severe nosocomial infections with no defined treatment. Combination therapy with ceftazidime/ avibactam (CZA) and aztreonam (ATM) is a potential option, but there is no approved, feasible, synergy testing method for clinical labs to guide clinical decision making. Here, we evaluate the performance of 4 synergy testing methods using gradient-strips or disks. Methods We used 10 representative Enterobacterales strains, namely, E. coli, K. pneumoniae, and E. cloacea, and 6 PA strains harboring MBL, GES or non-MBL enzymes (Fig 1). 4 strains were successfully treated with CZA-ATM in case reports, the rest were from the CDC AR Bank. Four synergy testing methods were evaluated, i) Disk stack (DS), ii) Disk elution (DE), iii) Gradient-strip Stack (SS), iv) Gradient-strip Cross (SX) (Fig 1). All methods were run side-by-side as per CLSI guidelines with broth microdilution (BMD) as the reference. Data is the mean of 3 replicates. Synergy is defined as a strain that is resistant (R) to ATM but drops to ≤ the susceptible (S) breakpoint (Table 1) in the presence of CZA (Fig 2). Categorical agreement (CA), very major error (VME), major error (ME), minor error (MI) were calculated across methods for CZA-ATM synergy relative to BMD. Summary of synergy testing methods evaluated CLSI Breakpoints used for this study Results All CRE with NDM and PA with GES were ATM-R, CZA-R and S to the CZA-ATM combination. PA with NDM or VIM remained R to CZA-ATM likely due to other mechanisms of resistance. CA was high for DE (100%), SS (81%, MI 19%), and SX (88%, MI 13%) but low for DS (25%, ME 54%, MI 31%). Representative strains are shown (Fig 2, Table 2). Removing PA, CA for DE, SS, and SX was 100% and 20% for DS. Representative results of strains with each synergy testing method. Representative data of strains displaying synergy (green) or no synergy (red) Conclusion Overall, DE was the most reliable method for CZA-ATM synergy testing, and could be a valuable tool in low-resource labs. SS and SX were reliable but prone to technical error. DS had the worst performance. Disks and gradient-strips had identical performance across brands. We propose an algorithm for ATM-R, CZA-R, and MBL-positive CRE, where CZA-ATM synergy testing may be beneficial to guide therapy. These methods are reliable qualitative indicators of the presence or absence of synergy. Synergy testing is not recommended for CR-PA due to complex resistance profiles. Disclosures Cesar A. Arias, M.D., MSc, Ph.D., FIDSA, Entasis Therapeutics (Scientific Research Study Investigator)MeMed (Scientific Research Study Investigator)Merck (Grant/Research Support) William R. Miller, MD, Entasis Therapeutics (Scientific Research Study Investigator)Merck (Grant/Research Support)Shionogi (Advisor or Review Panel member)

scholarly journals Seed viability of common ragweed (Ambrosia artemisiifolia L.) is affected by seed origin and age, but also by testing method and laboratory

NeoBiota ◽  
2021 ◽  
Vol 70 ◽  
pp. 193-221
Author(s):  
Rea Maria Hall ◽  
Bernhard Urban ◽  
Hana Skalova ◽  
Lenka Moravcová ◽  
Ulrike Sölter ◽  
...  
Keyword(s):  
Seed Viability ◽  
Ambrosia Artemisiifolia ◽  
Testing Methods ◽  
Triphenyltetrazolium Chloride ◽  
Viability Test ◽  
Common Ragweed ◽  
Testing Procedures ◽  
Testing Method ◽  
Seed Origin ◽  
Set Up

Common ragweed (Ambrosia artemisiifolia L.) is an annual Asteraceae species native to North America which is highly invasive across Europe and has harmful impacts, especially on human health and agriculture. Besides its wide ecological range, particularly its high reproductive power by seeds is promoting its spread to various habitats and regions. To prevent further spread and to control the plant, the European Commission funded projects and COST-Actions involving scientists from all over Europe. A joint trial was set up comprising eight different laboratories from Europe to study seed viability variation in different seed samples. Three different testing methods (viability test with 2,3,5-triphenyltetrazolium chloride (TTC), a germination test combined with a subsequent TTC test and a crush test) were tested within the EU-COST-Action SMARTER network to four different seed origins. The viability test results from different laboratories were compared for variation amongst tests and laboratories. The main aim was to optimise the reliability of testing procedures, but results revealed not only significant effects of seed origin and seed age on seed viability, but also considerable differences between the output of the individual testing methods and furthermore between laboratories. Due to these significant differences in the results of the testing labs, additionally a second test was set up. Twelve Austrian ragweed populations were used for TTC testing to obtain a precise adjustment of the testing method as well as a tight guideline for interpreting the results, particularly for the TTC state “intermediate” since a proper classification of TTC-intermediate coloured seeds is still a challenge when determining viability rates.

scholarly journals Research on the Computer Software Testing Method Based on Multiple Platforms

2020 ◽  
Vol 2 (3) ◽  
Author(s):  
Yongfang Sun ◽  
Jianjun Li
Keyword(s):  
Software Development ◽  
Software Testing ◽  
Computer Software ◽  
Test Accuracy ◽  
Testing Methods ◽  
Modern Life ◽  
Testing Method ◽  
Software Companies ◽  
And Control

Informationization plays an important role in modern life and production. And various software is one of the bases for it. Before it goes into service, software needs to go through many steps, including software development, design, etc. In software development, test is the key to identify and control bugs and errors in the software. Therefore, software companies often test the software to ensure that it is qualified. In recent years, more attention has been paid to a multi-platform computer software testing method, which can make up for defects in traditional testing methods to improve test accuracy. Firstly, this paper illustrates the connotation and features of software testing. Secondly, common software testing platforms and their requirements are analyzed. Finally, this paper proposes software testing method based on multiple platforms.

scholarly journals Assessing Operability on Berthed Ships. Common Approaches, Present and Future Lines

2020 ◽  
Vol 8 (4) ◽  
pp. 255
Author(s):  
Rafael Molina-Sanchez ◽  
Álvaro Campos ◽  
Marta de Alfonso ◽  
Francisco J. de los Santos ◽  
Pablo Rodríguez-Rubio ◽  
...  
Keyword(s):  
Field Monitoring ◽  
Economic Losses ◽  
Extreme Conditions ◽  
Factors Affecting ◽  
Logistic Chain ◽  
Main Factors ◽  
Port Areas

The revenue of a ship company, a terminal, a port and even the whole logistic chain largely depends on the performance of (un)loading operations inside port areas. However, they are conditioned by met-ocean agents that exert stresses on fixed structures, berthed ships and mooring systems that can affect the comfort, productivity and safety of the operations. Under extreme conditions, operations may be interrupted, producing periods of inactivity, economic losses and even jeopardizing the terminal’s reliability. Therefore, it is crucial to develop strategies for characterizing and predicting operability in docks and anchorages. The present paper aims to assess the main approaches up to date to address the operability on berthed ships and to explore present and future strategies. To accomplish this, main factors affecting the operability are reviewed and different methodologies for the characterization and calculation of operability are detailed, together with some results regarding the perception of vulnerability from the Spanish port community. Rather than aiming for generic mono-parametric thresholds, the results highlight the need for addressing this challenge in a specific way for each dock and anchorage, broadening field monitoring and considering the varied peculiarities and the specific perception and experience of main port’s actors.

scholarly journals Hard Quasicrystalline Coatings Deposited by HVOF Thermal Spray to Reduce Ice Accretion in Aero-Structures Components

Coatings ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 290
Author(s):  
J. Mora ◽  
P. García ◽  
R. Muelas ◽  
A. Agüero
Keyword(s):  
Thermal Spray ◽  
Surface Engineering ◽  
High Hardness ◽  
Ceramic Materials ◽  
Ice Accretion ◽  
Adhesion Properties ◽  
Wetting Properties ◽  
Lap Shear ◽  
Hvof Thermal Spray ◽  
Ice Adhesion

Weather hazards, in particular icing conditions, are an important contributing factor in aviation accidents and incidents worldwide. Many different anti-icing strategies are currently being explored to find suitable long-lasting solutions, such as surface engineering, which can contribute to reduce ice accumulation. Quasicrystals (QCs) are metallic materials, but with similar properties to those of ceramic materials, such as low thermal and electrical conductivities, and high hardness. In particular, QCs that have low surface energy are commercially used as coatings to replace polytetrafluoroethylene (PTFE), also known as Teflon, on frying pans, as they do not scratch easily. PTFE exhibits excellent anti-wetting and anti-icing properties and therefore QCs appear as good candidates to be employed as ice-phobic coatings. Al-based QCs have been applied by High Velocity Oxyfuel (HVOF) thermal spray on typically used aeronautic materials, such as Ti and Al alloys, as well as steels. The coatings have been characterized and evaluated, including the measurement of hardness, roughness, wetting properties, ice accretion behavior in an icing wind tunnel (IWT), and ice adhesion by a double lap shear test. The coatings were studied, both as-deposited, as well as after grinding, in order to study the effect of the surface roughness and morphology on the ice accretion and adhesion properties. The QC coating was compared with PTFE and two polyurethane (PU)-based commercial paints, one of them known to have anti-icing properties, and the results indicate an ice accretion reduction relative to these two materials, and ice adhesion lower than bare AA6061-T6, or the PU paint in the ground version of one of the two QCs. Since the QC coatings are hard (GPa Vickers hardness > 5), a durable behavior is expected.

Mechanically robust superhydrophobic coating for aeronautical composite against ice accretion and ice adhesion

2019 ◽  
Vol 176 ◽  
pp. 107267 ◽  
Author(s):  
Wei Tong ◽  
Dangsheng Xiong ◽  
Nan Wang ◽  
Zhen Wu ◽  
Huangjie Zhou
Keyword(s):  
Ice Accretion ◽  
Superhydrophobic Coating ◽  
Ice Adhesion

scholarly journals Metamorphic Testing Integer Overflow Faults of Mission Critical Program: A Case Study

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Zhanwei Hui ◽  
Song Huang ◽  
Zhengping Ren ◽  
Yi Yao
Keyword(s):  
Collision Avoidance ◽  
Traditional Method ◽  
Property Testing ◽  
Testing Methods ◽  
Metamorphic Testing ◽  
Testing Method ◽  
Safety Property ◽  
Mission Critical ◽  
Collision Avoidance System

For mission critical programs, integer overflow is one of the most dangerous faults. Different testing methods provide several effective ways to detect the defect. However, it is hard to validate the testing outputs, because the oracle of testing is not always available or too expensive to get, unless the program throws an exception obviously. In the present study, the authors conduct a case study, where the authors apply a metamorphic testing (MT) method to detect the integer overflow defect and alleviate the oracle problem in testing critical program of Traffic Collision Avoidance System (TCAS). Experimental results show that, in revealing typical integer mutations, compared with traditional safety property testing method, MT with a novel symbolic metamorphic relation is more effective than the traditional method in some cases.

New microbioassays based on biomarkers are more sensitive to fluvial water micropollution than standard testing methods

2013 ◽  
Vol 93 ◽  
pp. 52-59 ◽  
Author(s):  
S. Esteban ◽  
J. Fernández Rodríguez ◽  
G. Díaz López ◽  
M. Nuñez ◽  
Y. Valcárcel ◽  
...  
Keyword(s):  
Testing Methods ◽  
Standard Testing

scholarly journals New test method with a Hybrid III Anthropomorphic Dummy for Textile Safety Harnesses

2020 ◽  
Vol 28 (1(139)) ◽  
pp. 81-86
Author(s):  
Krzysztof Baszczyński
Keyword(s):  
Test Method ◽  
Strength Testing ◽  
Head Acceleration ◽  
Testing Methods ◽  
Testing Method ◽  
Experimental Stand ◽  
Hybrid Iii ◽  
Mechanical Factors ◽  
Fall Arrest ◽  
Full Body

A full body harness is a basic component of personal fall arrest equipment. It is made from webbing connected by seams and metal fittings to firmly hold and support the user’s body. The paper proposes a new method for full body harness testing using a Hybrid III anthropomorphic dummy; also the design of the experimental stand and software used are described. The method analyses the behaviour of a dummy during a fall arrest under well-defined conditions. The critical mechanical factors measured during the study presented were: the head acceleration, forces acting on the spine, the position of the dummy, the impacts of harness elements to the head, etc. The tests identified some potentially dangerous phenomena associated with falls from a height. The harness testing method developed turned out to be a valuable tool that should be applied in conjunction with existing strength testing methods.

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