Influence of Various Binder of the Protective Properties of Paint Coatings

2009 ◽  
Vol 415 ◽  
pp. 73-76
Author(s):  
Cristian Pirvu ◽  
Rodica Stancu ◽  
Paula Drob ◽  
Ecaterina Vasilescu ◽  
Cora Vasilescu ◽  
...  

The paper presents the results of the electrochemical and surface study concerning the binder influence on protective properties of paint coatings. The protective films realized with various binders were applied on carbon steel substrate. The experiments carried out in a 3% NaCl solution, normal aerated at the room temperature. The experimental results show that the paint films containing binders with three-dimensional (3D) structure provide good protective properties. The best performance is exhibited by the paint films with the alkyd binder, due to their 3D structure formed as a result of chemical reactions of the binder with the oxygen from atmosphere during the curing process.

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
D. Elango ◽  
A. Daniel Das ◽  
S. P. Kumaresh Babu ◽  
S. Natarajan ◽  
A. Yeshitla

In this present research, the coatings of SA209-T1 using high velocity oxygen fuel were employed for the application of boiler tubes. Due to the adaptation of corrosion easy in boiler material, the research of those properties is significant because of its criticality and functionality during the service time. A right coating was found and applied on the SA209-T1 surface against corrosive environments. Good corrosion resistance is achieved by WC-flyash coatings applied on SA209-T1 substrate. The 90% WC-10% flyash coatings were found to be more protective followed by SA209-T1 steel. WC-flyash covering was tracked down so that the covering is compelling to secure the SA209-T1 steel substrate. It is reasoned that the arrangement of NiO, Cr2O3, CoO, and NiCr2O4 could add to the advancement of consumption opposition in coatings. The steel of uncoated endured erosion as extraordinary stripping and spalling of the scale, which could be because of the development of Fe2O3 oxide scale unprotectively. This paper reveals the performance, applications, and development of 90wt.% WC and 10wt.% fly ash through HVOF coating in SA209-T1 for electrochemical corrosion studies at room temperature.


2007 ◽  
Vol 72 (12) ◽  
pp. 1383-1392 ◽  
Author(s):  
Jelena Bajat ◽  
Vesna Miskovic-Stankovic ◽  
Dragutin Drazic

One of the most important factors in corrosion prevention by protective coatings is the loss of coating adhesion under environmental influence. In this work, the adhesion of epoxy cataphoretic coatings was examined on steel and steel modified by Zn-Fe and Zn-Co alloys. The dry and wet adhesions of epoxy primers were measured by the direct pull-off standardized procedure, as well as indirectly by the NMP test. The corrosion stability of the coated samples was investigated by electrochemical impedance spectroscopy. It was shown that under dry testing conditions all the samples exhibited very good adhesion. However, different trends of adhesion loss of different protective systems during exposure to a corrosive agent (3 % NaCl solution) were observed. The lowest adhesion values were obtained for epoxy coating on the steel substrate. The change in adhesion of the epoxy coating on steel modified by Zn-Co alloy during immersion in 3 % NaCl solution for 24 days was the smallest of all the investigated samples. Electrochemical impedance measurements in 3 % NaCl solution confirmed the good protective properties of this protective system, i.e., greater values of pore resistance were obtained.


Author(s):  
Jun Taniguchi ◽  
Shin-ichi Satake ◽  
Noriyuki Unno ◽  
Takahiro Kanai

UV nanoimprint lithography (UV-NIL) is powerful tool of nano-fabrication. This process is simple and quickly pattern transfer method because of room temperature process. Now, in this process sometimes generates the errors about shortage of filling or volume shrinking by photo-curable process. Therefore, observation of UV photo-curable resin behaviors at curing process is important. To observe this phenomenon, micro digital-holographic particle-tracking velocimetry (micro-DHPTV) method was used. This measurement method has sub-micron three dimensional spatial resolutions and high time-resolution at Newton fluid. The UV photo-curable resin is low viscosity liquid and observation was carried out. In conclusion, curing process of UV photo-curable resin was observed by micro-DHPTV.


Author(s):  
J. Frank ◽  
B. F. McEwen ◽  
M. Radermacher ◽  
C. L. Rieder

The tomographic reconstruction from multiple projections of cellular components, within a thick section, offers a way of visualizing and quantifying their three-dimensional (3D) structure. However, asymmetric objects require as many views from the widest tilt range as possible; otherwise the reconstruction may be uninterpretable. Even if not for geometric obstructions, the increasing pathway of electrons, as the tilt angle is increased, poses the ultimate upper limitation to the projection range. With the maximum tilt angle being fixed, the only way to improve the faithfulness of the reconstruction is by changing the mode of the tilting from single-axis to conical; a point within the object projected with a tilt angle of 60° and a full 360° azimuthal range is then reconstructed as a slightly elliptic (axis ratio 1.2 : 1) sphere.


Author(s):  
Jaap Brink ◽  
Wah Chiu

The crotoxin complex is a potent neurotoxin composed of a basic subunit (Mr = 12,000) and an acidic subunit (M = 10,000). The basic subunit possesses phospholipase activity whereas the acidic subunit shows no enzymatic activity at all. The complex's toxocity is expressed both pre- and post-synaptically. The crotoxin complex forms thin crystals suitable for electron crystallography. The crystals diffract up to 0.16 nm in the microscope, whereas images show reflections out to 0.39 nm2. Ultimate goal in this study is to obtain a three-dimensional (3D-) structure map of the protein around 0.3 nm resolution. Use of 100 keV electrons in this is limited; the unit cell's height c of 25.6 nm causes problems associated with multiple scattering, radiation damage, limited depth of field and a more pronounced Ewald sphere curvature. In general, they lead to projections of the unit cell, which at the desired resolution, cannot be interpreted following the weak-phase approximation. Circumventing this problem is possible through the use of 400 keV electrons. Although the overall contrast is lowered due to a smaller scattering cross-section, the signal-to-noise ratio of especially higher order reflections will improve due to a smaller contribution of inelastic scattering. We report here our preliminary results demonstrating the feasability of the data collection procedure at 400 kV.Crystals of crotoxin complex were prepared on carbon-covered holey-carbon films, quench frozen in liquid ethane, inserted into a Gatan 626 holder, transferred into a JEOL 4000EX electron microscope equipped with a pair of anticontaminators operating at −184°C and examined under low-dose conditions. Selected area electron diffraction patterns (EDP's) and images of the crystals were recorded at 400 kV and −167°C with dose levels of 5 and 9.5 electrons/Å, respectively.


Author(s):  
Jose-Maria Carazo ◽  
I. Benavides ◽  
S. Marco ◽  
J.L. Carrascosa ◽  
E.L. Zapata

Obtaining the three-dimensional (3D) structure of negatively stained biological specimens at a resolution of, typically, 2 - 4 nm is becoming a relatively common practice in an increasing number of laboratories. A combination of new conceptual approaches, new software tools, and faster computers have made this situation possible. However, all these 3D reconstruction processes are quite computer intensive, and the middle term future is full of suggestions entailing an even greater need of computing power. Up to now all published 3D reconstructions in this field have been performed on conventional (sequential) computers, but it is a fact that new parallel computer architectures represent the potential of order-of-magnitude increases in computing power and should, therefore, be considered for their possible application in the most computing intensive tasks.We have studied both shared-memory-based computer architectures, like the BBN Butterfly, and local-memory-based architectures, mainly hypercubes implemented on transputers, where we have used the algorithmic mapping method proposed by Zapata el at. In this work we have developed the basic software tools needed to obtain a 3D reconstruction from non-crystalline specimens (“single particles”) using the so-called Random Conical Tilt Series Method. We start from a pair of images presenting the same field, first tilted (by ≃55°) and then untilted. It is then assumed that we can supply the system with the image of the particle we are looking for (ideally, a 2D average from a previous study) and with a matrix describing the geometrical relationships between the tilted and untilted fields (this step is now accomplished by interactively marking a few pairs of corresponding features in the two fields). From here on the 3D reconstruction process may be run automatically.


Foods ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1809
Author(s):  
Zhanzhi Liu ◽  
Ying Li ◽  
Jing Wu ◽  
Sheng Chen

d-mannose has exhibited excellent physiological properties in the food, pharmaceutical, and feed industries. Therefore, emerging attention has been applied to enzymatic production of d-mannose due to its advantage over chemical synthesis. The gene age of N-acetyl-d-glucosamine 2-epimerase family epimerase/isomerase (AGEase) derived from Pseudomonas geniculata was amplified, and the recombinant P. geniculata AGEase was characterized. The optimal temperature and pH of P. geniculata AGEase were 60 °C and 7.5, respectively. The Km, kcat, and kcat/Km of P. geniculata AGEase for d-mannose were 49.2 ± 8.5 mM, 476.3 ± 4.0 s−1, and 9.7 ± 0.5 s−1·mM−1, respectively. The recombinant P. geniculata AGEase was classified into the YihS enzyme subfamily in the AGE enzyme family by analyzing its substrate specificity and active center of the three-dimensional (3D) structure. Further studies on the kinetics of different substrates showed that the P. geniculata AGEase belongs to the d-mannose isomerase of the YihS enzyme. The P. geniculata AGEase catalyzed the synthesis of d-mannose with d-fructose as a substrate, and the conversion rate was as high as 39.3% with the d-mannose yield of 78.6 g·L−1 under optimal reaction conditions of 200 g·L−1d-fructose and 2.5 U·mL−1P. geniculata AGEase. This novel P. geniculata AGEase has potential applications in the industrial production of d-mannose.


2014 ◽  
Vol 70 (9) ◽  
pp. i46-i46 ◽  
Author(s):  
Matthias Weil ◽  
Thomas Häusler

The crystal structure of the room-temperature modification of K[Hg(SCN)3], potassium trithiocyanatomercurate(II), was redetermined based on modern CCD data. In comparison with the previous report [Zhdanov & Sanadze (1952).Zh. Fiz. Khim.26, 469–478], reliability factors, standard deviations of lattice parameters and atomic coordinates, as well as anisotropic displacement parameters, were revealed for all atoms. The higher precision and accuracy of the model is, for example, reflected by the Hg—S bond lengths of 2.3954 (11), 2.4481 (8) and 2.7653 (6) Å in comparison with values of 2.24, 2.43 and 2.77 Å. All atoms in the crystal structure are located on mirror planes. The Hg2+cation is surrounded by four S atoms in a seesaw shape [S—Hg—S angles range from 94.65 (2) to 154.06 (3)°]. The HgS4polyhedra share a common S atom, building up chains extending parallel to [010]. All S atoms of the resulting1∞[HgS2/1S2/2] chains are also part of SCN−anions that link these chains with the K+cations into a three-dimensional network. The K—N bond lengths of the distorted KN7polyhedra lie between 2.926 (2) and 3.051 (3) Å.


2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Sevda Pouraghaei Sevari ◽  
Sahar Ansari ◽  
Alireza Moshaverinia

AbstractTissue engineering approaches have emerged recently to circumvent many limitations associated with current clinical practices. This elegant approach utilizes a natural/synthetic biomaterial with optimized physiomechanical properties to serve as a vehicle for delivery of exogenous stem cells and bioactive factors or induce local recruitment of endogenous cells for in situ tissue regeneration. Inspired by the natural microenvironment, biomaterials could act as a biomimetic three-dimensional (3D) structure to help the cells establish their natural interactions. Such a strategy should not only employ a biocompatible biomaterial to induce new tissue formation but also benefit from an easily accessible and abundant source of stem cells with potent tissue regenerative potential. The human teeth and oral cavity harbor various populations of mesenchymal stem cells (MSCs) with self-renewing and multilineage differentiation capabilities. In the current review article, we seek to highlight recent progress and future opportunities in dental MSC-mediated therapeutic strategies for tissue regeneration using two possible approaches, cell transplantation and cell homing. Altogether, this paper develops a general picture of current innovative strategies to employ dental-derived MSCs combined with biomaterials and bioactive factors for regenerating the lost or defective tissues and offers information regarding the available scientific data and possible applications.


2020 ◽  
Vol 53 (03) ◽  
pp. 324-334
Author(s):  
Gautam Biswas

Abstract Reconstruction of the complex anatomy and aesthetics of the midface is often a challenge. A careful understanding of this three-dimensional (3D) structure is necessary. Anticipating the extent of excision and its planning following oncological resections is critical.In the past over two decades, with the advances in microsurgical procedures, contributions toward the reconstruction of this area have generated interest. Planning using digital imaging, 3D printed models, osseointegrated implants, and low-profile plates, has favorably impacted the outcome. However, there are still controversies in the management: to use single composite tissues versus multiple tissues; implants versus autografts; vascularized versus nonvascularized bone; prosthesis versus reconstruction.This article explores the present available options in maxillary reconstruction and outlines the approach in the management garnered from past publications and experiences.


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