scholarly journals Thermal Volumetric Analysis (TVA): A New Test Method of the Kinetics of Gas Emissions from Moulding Sands and Protective Coatings Heated by Liquid Alloy

Author(s):  
Jerzy Stanisław Zych ◽  
Jan Mocek

Author(s):  
N.I. Konstantinova ◽  
◽  
N.V. Smirnov ◽  
O.V. Krivoshapkina ◽  
O.I. Molchadskiy ◽  
...  

Fiber cement finishing materials are widely used in the construction of industrial buildings and structures due to the complex of valuable operational properties. In the Russian market there are fiber-cement panels with a variety of design solutions for their coloring and application of protective coatings. Fiber cement board is a strong and moisture-resistant composite material made from a cement-sand mixture, reinforcing cellulose fibers and special additives. Not being a non-combustible material, the fiber cement boards in accordance with the current mandatory requirements, as a decorative, finishing and facing material for walls and ceilings have restrictions on their use. Existing domestic requirements regarding the methodology for assessing the combustibility of fiber cement products largely narrow the field of using these materials. Therefore, it is advisable to develop the proposals for amending the test methods and the regulatory framework governing their fire-safe extended scope. In the course of this work execution, the main provisions of the regulatory and methodological framework that establish the requirements for the fire-safe use of fiber cement materials are analyzed. Experimental complex studies of fire hazard properties of various types of samples of the fiber cement finishing panels and slabs were carried out. It is established that fiber-cement materials belong to the class of the least fire-hazardous materials. Advisability is determined concerning the introduction to the national regulatory practice of GOST R «Building materials. Test method for fire hazard under thermal exposure with a single burner (SBI)». Classification parameters of the group of non-combustible materials NG2 were established to amend GOST R 57270—2016 (method 1). Classification parameters of the group of non-combustible materials NG2 for making changes in GOST R 57270—2016 (method 1) are established. Proposals were developed to expand the scope of application of the materials and products made of fiber cement as enclosing structures, partitions, and decorative finishes (cladding) in the buildings and structures.



2018 ◽  
Vol 5 (4) ◽  
pp. 94
Author(s):  
Holly Clingan ◽  
Devon Rusk ◽  
Kathryn Smith ◽  
Antonio Garcia

In lateral flow and colorimetric test strip diagnostics, the effects of capillary action and diffusion on speed and sensitivity have been well studied. However, another form of fluid motion can be generated due to stresses and instabilities generated in pores when two miscible liquids with different densities and viscosities come into contact. This study explored how a swellable test pad can be deployed for measuring urea in saliva by partially prefilling the pad with a miscible solution of greater viscosity and density. The resultant Korteweg stresses and viscous fingering patterns were analyzed using solutions with added food color through video analysis and image processing. Image analysis was simplified using the saturation channel after converting RGB image sequences to HSB. The kinetics of liquid mixing agreed with capillary displacement results for miscible liquids undergoing movement from Korteweg stresses. After capillary filling, there was significant movement of liquid due to these fluidic effects, which led to mixing of the saliva sample with an enzyme test solution. Owing to the simplicity and speed of this test method, urea can be analyzed with an electronic nose over a useful range for detecting salivary urea concentration for rapid and early detection of dehydration.



2013 ◽  
Vol 53 (1) ◽  
pp. 127
Author(s):  
Neil Wilds

Corrosion under insulation (CUI) is a serious issue in the oil and gas industry, with failures often occurring without warning and having devastating effect. When expensive redesign is not possible or practical, operators have a number of options open to them to mitigate the risk of CUI; these include the use of various protective coatings or thermally sprayed metals. Despite a number of technologies presently available, the industry is yet to establish an accepted laboratory test method for the performance benchmarking of products. This has, in the past, damaged confidence in some solutions and hampered the selection and further development of CUI coatings. As a result, the subject of accelerated laboratory testing for CUI coatings is now receiving significant attention across the industry with joint industry programs proposed in both Europe and North America. This paper will examine state-of-the-art accelerated CUI testing, evaluating the advantages and disadvantages of the existing methods available. It will then offer a detailed description of a test method that has been in use since 2004, testing more than 300 specimens and assessing a wide range of coating technologies. The reproducibility of the test program will be established by the presentation of a range of data including results obtained from a third-party test house. The third-party results will then be correlated with a seven-year case study from an end user perspective provided by Santos, a major Australian oil and gas exploration and production company, from experiences at their Port Bonython facility in SA.



1995 ◽  
Vol 38 (1) ◽  
pp. 19-28
Author(s):  
J. Garrett ◽  
A. Glassford ◽  
J. Steakley

The American Society for Testing and Materials (ASTM) has published a new standard test method for characterizing time and temperature dependence of material outgassing kinetics and the deposition kinetics of outgassed species on surfaces at various temperatures. This new ASTM standard, E 1559,1 uses the quartz crystal microbalance (QCM) collection measurement approach. The test method was originally developed under a program sponsored by the U.S. Air Force Materials Laboratory to create a standard test method for obtaining outgassing and deposition kinetics data for spacecraft materials. Standardization by ASTM recognizes that the method has applications beyond aerospace. In particular, the method will provide data of use to the electronics, semiconductor, and high vacuum industries. This paper describes the ASTM E 1559 test method and presents some typical data. the paper also describes the Lockheed ASTM E 1559 test apparatus.



1999 ◽  
Vol 276 (4) ◽  
pp. H1167-H1171 ◽  
Author(s):  
Scott H. Buck ◽  
Patrick J. Konyn ◽  
Joseph Palermo ◽  
Jeffrey Robbins ◽  
Richard L. Moss

To investigate the role of myosin regulatory light chain isoforms as a determinant of the kinetics of cardiac contraction, unloaded shortening velocity was determined by the slack-test method in skinned wild-type murine atrial cells and transgenic cells expressing ventricular regulatory light chain (MLC2v). Transgenic mice were generated using a 4.5-kb fragment of the murine α-myosin heavy chain promoter to drive high levels of MLC2v expression in the atrium. Velocity of unloaded shortening was determined at 15°C in maximally activating Ca2+ solution (pCa 4.5) containing (in mmol/l) 7 EGTA, 1 free Mg2+, 4 MgATP, 14.5 creatine phosphate, and 20 imidazole (ionic strength 180 mmol/l, pH 7.0). Compared with the wild type ( n = 10), the unloaded shortening velocity of MLC2v-expressing transgenic murine atrial cells ( n = 10) was significantly greater (3.88 ± 1.19 vs. 2.51 ± 1.08 muscle lengths/s, P < 0.05). These results provide evidence that myosin light chain 2 regulates cross-bridge cycling rate. The faster rate of cycling in the presence of MLC2v suggests that the MLC2v isoform may contribute to the greater power-generating capabilities of the ventricle compared with the atrium.



Stroke ◽  
2015 ◽  
Vol 46 (suppl_1) ◽  
Author(s):  
Kristy Yuan ◽  
Rajat Dhar ◽  
Tobias Kulik ◽  
Yasheng Chen ◽  
Laura Heitsch ◽  
...  

Background: Large hemispheric infarcts (LHI) may be complicated by cerebral edema. Midline shift (MLS), a standard radiographic measure, only crudely estimates extent of edema. Volumetric analysis of CSF compartments over time may provide a reliable and accurate means of quantifying severity and kinetics of edema after LHI. Methods: We retrospectively identified stroke patients with NIHSS≥8 and baseline CT within 6 hours who developed cerebral edema (without hemorrhage) on follow-up (FU) CTs. Two raters outlined the sulci and lateral ventricles ipsilateral (IL) and contralateral (CL) to the infarct on baseline and serial FU CTs (both within 48 hours and at peak edema, 2-5 days post-stroke) and quantified CSF and infarct volumes. Changes in compartment volumes from baseline to peak edema CT were correlated with MLS and edema-related neurologic worsening (need for hemicraniectomy, osmotic therapy, or decline in GCS, associated with MLS≥5mm). Results: Ten patients were analyzed (median NIHSS 14, time to early FU CT 30 hours, IQR 15-37 and to peak edema CT 75 hours, IQR 64-95). Inter-rater reliability for volume measures was excellent (intraclass correlation >0.97). CSF volume diminished by 37±20% (49 ml) from baseline to peak edema, over half occurring within 48 hours; net decline in CSF volume correlated with infarct volume (r=-0.63,p=0.05). Greatest reductions in CSF were seen in IL sulci and IL ventricles (Figure, top), but it was % reduction in CL sulci that correlated best with MLS (Fig, bottom), even adjusting for infarct volume (p=0.02). Decline in volumes of IL and CL sulci were greater in the 5 subjects with neurological worsening (89% vs. 56% and 40% vs. 3%, p<0.05), while infarct volume was not. Conclusions: CSF volumetrics is a reliable tool for quantifying cerebral edema after LHI and a novel method of studying edema kinetics. Loss of sulcal volume correlates with MLS and is more strongly associated with edema-related deterioration than infarct volume alone.





2021 ◽  
Vol 33 (1) ◽  
Author(s):  
Andrea Brunelli ◽  
Loris Calgaro ◽  
Elena Semenzin ◽  
Virginia Cazzagon ◽  
Elisa Giubilato ◽  
...  

AbstractThe development of highly innovative techniques and technologies to enhance performance and technical sustainability of materials used in the field of cultural heritage conservation is providing conservators with innovative nanocomposites materials, including protective coatings, by merging the performances of engineered nanoparticles (NPs) with conventional chemicals. However, the human health and environmental risks that may potentially arise from these new materials are still largely unknown, requiring an adequate assessment and management along their entire life cycle. Concerns could emerge due to the leaching of the material containing NPs or of the NPs alone, especially during their use (exposure of the treated object to, e.g., heavy or acid rain) and disposal (when the wasted product is processed in, e.g., waste water treatment plants). To date, no standard leaching test methods have been specifically developed for nano-enabled products, with the consequent lack of data on the NPs potential exposure also in the field of cultural heritage. Therefore, an extensive review over the last 10 years by querying to the Scopus database “nanoparticles”, “leaching” and “coatings” has been herein reported to clearly highlight (i) the standard test methods used or adapted to estimate the NPs leaching from nano-based coatings; (ii) the available studies in which the NPs leaching from nano-based coatings was estimated without following any specific standard test method; (iii) the works focusing on other nanocomposite materials performances than leaching, in which standard test methods were applied, potentially useful to indirectly estimate NPs leaching. All the information gathered by this bibliographic search have been used to identify the most promising leaching tests for NPs estimation to be applied in the field of cultural heritage, especially for both large, e.g., building façades, and small, e.g., bronze works of art, surface areas from which the leaching of nano-based materials could be significant in terms of human health and ecological risks, based also on the (eco)toxicity of the leachate. The derived information can thus ultimately support effective risk management of innovative nano-enabled products, including the implementation of Safe by Design approaches.



Materials ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 6940
Author(s):  
Agnieszka Elżbieta Kochmańska ◽  
Aneta Jarlaczyńska ◽  
Jolanta Baranowska

New slurry cementation method was used to produce silicide and silicide-aluminide protective coatings on molybdenum alloy (TZM). The slurry cementation processes were carried out at a temperature of 1000 °C in different time intervals with the use of varied slurry mass values. The microstructure and thickness of the coatings were studied by means of scanning microscopy. Chemical composition using X-ray microanalysis and phase composition using X-ray diffraction were also investigated. Coating microhardness was determined. The obtained coatings had a multilayer structure. Phases from the Al-Si-Mo system were observed in silicide-aluminide coatings and phases from the Si-Mo system were observed in silicide coatings. The microhardness strongly depended on the phase composition of the coating. It was demonstrated that slurry mass values had an important influence on the morphology and growth kinetics of silicide-aluminide coatings. In the case of a small amount of the slurry, the deficiency of alloying elements occurring during long processes reduces growth kinetics and can lead to void formation in the structure of silicide-aluminide coatings.



Sign in / Sign up

Export Citation Format

Share Document