Surface Topographical Characterization of Concrete Protected by Coal Tar Using 3D Profilometry

The results obtained for the characterization of the surface texture of concrete protected by coal tar using a 3D-topographical approach are presented here. The concrete, which presents a low waterbinder ratio, high compressive strength, and high impermeability, has been subjected to an aggressive acidic environment by immersion in 2.5%H2SO4. The profilometry technique, which produces 3D-topographical images and amplitude parameters, is used to compare the coated and uncoated surface textures before and after chemical attack, to evaluate the degradation of concrete, and the minimization of such effect in the coated concrete. The degradation and the minimization of degradation can be confirmed by the variation in all the parameters studied. This research, based on studies of profilometric analyses, demonstrates the accuracy, precision and efficiency of this technique in analyzing the concrete surface, indicating that it can be broadly employed in concrete durability research. The methodology adopted demonstrates that the application of coal tar as a protective coating for concrete in an aggressive environment minimizes its surface degradation and increases its durability.

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Effects of Anti-Graffiti Protection on Concrete Durability

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.634.517 ◽

2014 ◽

Vol 634 ◽

pp. 517-526 ◽

Cited By ~ 2

Author(s):

Elsa Neto ◽

Ana Souto ◽

Aires Camões ◽

Arlindo Begonha ◽

Paulo Cachim

Keyword(s):

Water Absorption ◽

Atmospheric Pressure ◽

Surface Characteristics ◽

Concrete Surface ◽

Experimental Program ◽

Concrete Durability ◽

Protection Systems ◽

Before And After ◽

Paint Removal ◽

Durability Of Concrete

The heritage of fair-faced concrete, largely built in the twentieth century and nowadays recognized as heritage to be protected, is susceptible to attacks by graffiti, a form of vandalism that causes a major social and economic impact on society. Concrete is a porous material sometimes deteriorated over the years, and the interactions between the inks and the substrate and removal methods sometimes deteriorate or alter the concrete surface, especially if it is necessary to repeat the removal process. The anti-graffiti products are applied on the surface of the concrete, hindering the adhesion of paints or preventing its penetration into the pores of concrete, which in turn facilitates their removal. However, it appears that many of the existing protective products on the market may also alter the surface characteristics of the concrete irreversibly. Considering that the durability of concrete depends on the composition and characteristics of the surface, it is essential to know the effects of anti-graffiti protection systems on the durability of concrete and adopt the appropriate methodology to preserve this heritage. Thus, an experimental program was developed for analyzing changes in durability indicators and surface properties that protect concrete from deterioration (i) concrete without protection before and after application of spray paint, (ii) concrete with protection before and after application of spray paint and (iii) after paint removal were studied. Two anti-graffiti products were evaluated: a permanent and a sacrificial one. Effects of the anti-graffiti systems on the concrete durability are investigated and the tests performed include: water absorption by capillary and immersion at atmospheric pressure. The results of the water absorption tests show that the graffiti protection reduces the water absorption into the concrete and facilitates the removal of the graffiti without affecting negatively the characteristics of the surface and thus contributing to improve its durability.

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An Electron Microscope Study of Interdiffusion and Compound Formation in Ta-Au Thin Films

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100070606 ◽

1973 ◽

Vol 31 ◽

pp. 32-33 ◽

Cited By ~ 1

Author(s):

T. C. Tisone ◽

S. Lau

Keyword(s):

Electron Microscope ◽

Electron Microscope Study ◽

Thermally Grown Oxide ◽

Ion Milling ◽

Compound Formation ◽

Technology Application ◽

Transmission Electron ◽

Before And After ◽

Au Thin Films

In a study of the properties of a Ta-Au metallization system for thin film technology application, the interdiffusion between Ta(bcc)-Au, βTa-Au and Ta2M-Au films was studied. Considered here is a discussion of the use of the transmission electron microscope(TEM) in the identification of phases formed and characterization of the film microstructures before and after annealing.The films were deposited by sputtering onto silicon wafers with 5000 Å of thermally grown oxide. The film thicknesses were 2000 Å of Ta and 2000 Å of Au. Samples for TEM observation were prepared by ultrasonically cutting 3mm disks from the wafers. The disks were first chemically etched from the silicon side using a HNO3 :HF(19:5) solution followed by ion milling to perforation of the Au side.

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Comparative Characterization of Water Quality of Brari-Nambal La goon of Dal Lake Before and After Kashmir Floods

Current Environmental Engineering ◽

10.2174/2212717804666161214143148 ◽

2017 ◽

Vol 4 (2) ◽

Author(s):

Faizanul Mukhtar ◽

Hamida Chisti ◽

Shabir A. Bhat

Keyword(s):

Water Quality ◽

Comparative Characterization ◽

Dal Lake ◽

Before And After

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EVALUATION OF TRIBOTECHNICAL PROPERTIES OF THE COATING OBTAINED BY ELECTRIC SPARK HARDENING

Tekhnicheskiy servis mashin ◽

10.22314/2618-8287-2020-58-1-157-163 ◽

2020 ◽

Vol 4 (141) ◽

pp. 157-163

Author(s):

IL’YA ROMANOV ◽

◽

ROMAN ZADOROZHNIY

Keyword(s):

Wear Resistance ◽

Reference Sample ◽

Optical Microscope ◽

Research Purpose ◽

Tribotechnical Properties ◽

Uncoated Surface ◽

Before And After ◽

Materials Used ◽

Friction Track

When applying coatings using various methods on the surfaces of moving parts that work in joints, it is important to make sure that the coatings are strong and wear-resistant in order to return them to their original resource. All existing hardening technologies and materials used to perform coatings have their own characteristics, therefore, the quality of the resulting coatings can be judged only after specific tests. (Research purpose) The research purpose is in evaluating the properties of the coating obtained by the method of electric spark hardening, and its ability to resist friction and mechanical wear. (Materials and methods) Authors conducted tests on the basis of the "Nano-Center" center for collective use. A coating was applied on the BIG-4M unit with a VK-8 hard alloy electrode, tribological properties were evaluated on a CSM Instruments TRB-S-DE-0000 tribometer, the width of the friction track was measured after the test using an inverted OLYMPUS gx51 optical microscope, and samples were weighed before and after the test on a VLR-200 analytical balance. Conducted research in accordance with GOST 23.224-86 and RD 50-662-88 guidelines. (Results and discussion) The article presents performed tests on the run-in and wear resistance of the coating. The samples were worked on with a step-by-step increase in the load. During the tests, the friction force was drawed on the diagram. Authors compared the results with the reference sample, an uncoated surface. (Conclusions) The resulting coating has better run-in and wear resistance compared to the standard, and the increase in wear resistance in dry friction conditions is very significant.

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Adsorption Studies on Magnetic Nanoparticles Functionalized with Silver to Remove Nitrates from Waters

Water ◽

10.3390/w13131757 ◽

2021 ◽

Vol 13 (13) ◽

pp. 1757

Author(s):

Yesica Vicente-Martínez ◽

Manuel Caravaca ◽

Antonio Soto-Meca ◽

Miguel Ángel Martín-Pereira ◽

María del Carmen García-Onsurbe

Keyword(s):

Magnetic Nanoparticles ◽

Nitrate Content ◽

Adsorption Efficiency ◽

Experimental Conditions ◽

Dependent Behavior ◽

Before And After ◽

Naoh Solution ◽

High Concentrations ◽

Interference Studies

This paper presents a novel procedure for the treatment of contaminated water with high concentrations of nitrates, which are considered as one of the main causes of the eutrophication phenomena. For this purpose, magnetic nanoparticles functionalized with silver (Fe3O4@AgNPs) were synthesized and used as an adsorbent of nitrates. Experimental conditions, including the pH, adsorbent and adsorbate dose, temperature and contact time, were analyzed to obtain the highest adsorption efficiency for different concentration of nitrates in water. A maximum removal efficiency of 100% was reached for 2, 5, 10 and 50 mg/L of nitrate at pH = 5, room temperature, and 50, 100, 250 and 500 µL of Fe3O4@AgNPs, respectively. The characterization of the adsorbent, before and after adsorption, was performed by energy dispersive X-ray spectroscopy, scanning electron microscopy, Brunauer-Emmett-Teller analysis and Fourier-transform infrared spectroscopy. Nitrates can be desorbed, and the adsorbent can be reused using 500 µL of NaOH solution 0.01 M, remaining unchanged for the first three cycles, and exhibiting 90% adsorption efficiency after three regenerations. A deep study on equilibrium isotherms reveals a pH-dependent behavior, characterized by Langmuir and Freundlich models at pH = 5 and pH = 1, respectively. Thermodynamic studies were consistent with physicochemical adsorption for all experiments but showed a change from endothermic to exothermic behavior as the temperature increases. Interference studies of other ions commonly present in water were carried out, enabling this procedure as very selective for nitrate ions. In addition, the method was applied to real samples of seawater, showing its ability to eliminate the total nitrate content in eutrophized waters.

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Assessment of Characteristics of Acid Mine Drainage Treated with Fly Ash

Applied Sciences ◽

10.3390/app11093910 ◽

2021 ◽

Vol 11 (9) ◽

pp. 3910

Author(s):

Saba Shirin ◽

Aarif Jamal ◽

Christina Emmanouil ◽

Akhilesh Kumar Yadav

Keyword(s):

Fly Ash ◽

Acid Mine Drainage ◽

Power Plants ◽

Mine Drainage ◽

Thermal Power ◽

Mineralogical Characterization ◽

Acid Mine ◽

Before And After ◽

Abandoned Coal Mines

Acid mine drainage (AMD) occurs naturally in abandoned coal mines, and it contains hazardous toxic elements in varying concentrations. In the present research, AMD samples collected from an abandoned mine were treated with fly ash samples from four thermal power plants in Singrauli Coalfield in the proximate area, at optimized concentrations. The AMD samples were analyzed for physicochemical parameters and metal content before and after fly ash treatment. Morphological, geochemical and mineralogical characterization of the fly ash was performed using SEM, XRF and XRD. This laboratory-scale investigation indicated that fly ash had appreciable neutralization potential, increasing AMD pH and decreasing elemental and sulfate concentrations. Therefore, fly ash may be effectively used for AMD neutralization, and its suitability for the management of coalfield AMD pits should be assessed further.

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Single Step 2-Port Device De-Embedding Algorithm for Fixture-DUT-Fixture Network Assembly

Electronics ◽

10.3390/electronics10111275 ◽

2021 ◽

Vol 10 (11) ◽

pp. 1275

Author(s):

Simone Scafati ◽

Enza Pellegrino ◽

Francesco de Paulis ◽

Carlo Olivieri ◽

James Drewniak ◽

...

Keyword(s):

Standard Technique ◽

Single Step ◽

Scattering Parameters ◽

Linear Set ◽

S Parameter ◽

Parameter Conversion ◽

Before And After ◽

One Step ◽

Typical Measurement

The de-embedding of measurement fixtures is relevant for an accurate experimental characterization of radio frequency and digital electronic devices. The standard technique consists in removing the effects of the measurement fixtures by the calculation of the transfer scattering parameters (T-parameters) from the available measured (or simulated) global scattering parameters (S-parameters). The standard de-embedding is achieved by a multiple steps process, involving the S-to-T and subsequent T-to-S parameter conversion. In a typical measurement setup, two fixtures are usually placed before and after the device under test (DUT) allowing the connection of the device to the calibrated vector network analyzer coaxial ports. An alternative method is proposed in this paper: it is based on the newly developed multi-network cascading algorithm. The matrices involved in the fixture-DUT-fixture cascading gives rise to a non-linear set of equations that is in one step analytically solved in closed form, obtaining a unique solution. The method is shown to be effective and at least as accurate as the standard multi-step de-embedding one.

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Transcriptomic analysis identifies differences in gene expression in actinic keratoses after treatment with imiquimod and between responders and non responders

Scientific Reports ◽

10.1038/s41598-021-88424-z ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Megan H. Trager ◽

Emanuelle Rizk ◽

Sharon Rose ◽

Kuixi Zhu ◽

Branden Lau ◽

...

Keyword(s):

Gene Expression ◽

Squamous Cell Carcinoma ◽

Distinct Pattern ◽

Study Endpoint ◽

Inflammatory Gene Expression ◽

Immune Modulators ◽

Actinic Keratoses ◽

Before And After ◽

Pre Treatment

AbstractThe presence of actinic keratoses (AKs) increases a patient’s risk of developing squamous cell carcinoma by greater than six-fold. We evaluated the effect of topical treatment with imiquimod on the tumor microenvironment by measuring transcriptomic differences in AKs before and after treatment with imiquimod 3.75%. Biopsies were collected prospectively from 21 patients and examined histologically. RNA was extracted and transcriptomic analyses of 788 genes were performed using the nanoString assay. Imiquimod decreased number of AKs by study endpoint at week 14 (p < 0.0001). Post-imiquimod therapy, levels of CDK1, CXCL13, IL1B, GADPH, TTK, ILF3, EWSR1, BIRC5, PLAUR, ISG20, and C1QBP were significantly lower (adjusted p < 0.05). Complete responders (CR) exhibited a distinct pattern of inflammatory gene expression pre-treatment relative to incomplete responders (IR), with alterations in 15 inflammatory pathways (p < 0.05) reflecting differential expression of 103 genes (p < 0.05). Presence of adverse effects was associated with improved treatment response. Differences in gene expression were found between pre-treatment samples in CR versus IR, suggesting that higher levels of inflammation pre-treament may play a part in regression of AKs. Further characterization of the immune micro-environment in AKs may help develop biomarkers predictive of response to topical immune modulators and may guide therapy.

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