One of the approaches for improving the protective performance of organic coatings is to add organic corrosion inhibitors in the formulation. The scope of this research is to investigate the corrosion behavior of mild steel in 3.5% sodium chloride solution with zinc phosphate anticorrosion pigment (ZP) and 2-mercaptobenzimidazole as organic inhibitor through taking advantage of electrochemical impedance spectroscopy (EIS) and polarization measurements. The results which were obtained from electrochemical tests on the samples within 24 hours of immersion in the solution indicated superior protective performance of the combination of zinc phosphate anticorrosion pigment and 2-mercaptobenzimidazole inhibitor compared to only the zinc phosphate pigment. In general¡ time variations of parameters charge transfer resistance (Rct) which was obtained from electrochemical impedance spectroscopy and polarization resistance (Rp) as well as corrosion current density (icorr) which were extracted from polarization curves implied precipitation of a protective layer on the surface in the presence of 2-mercaptobenzimidazole inhibitor.

This work is aimed to evaluate the role of nanoclay in the protective performance of an eco-friendly silane sol-gel layer applied on mild steel substrate in 0.1M sodium chloride solution. At the first step, the effect of pH of the silane solution, consisting of a mixture of γ-glycidoxypropiltrimethoxysilane and methyltriethoxysilane and tetraethoxysilane, on the coating performance was evaluated through electrochemical noise measurements. The values of characteristic charge as a parameter extracted from shot noise theory revealed that the sol pH determining the rate of hydrolysis can play an important role in the corrosion protection behavior of silane coatings. Then, the influence of clay nanoparticles on the corrosion protective performance of the hybrid silane film was studied through taking advantage of electrochemical techniques, including electrochemical impedance spectroscopy and polarization curves, as well as surface analysis methods. The obtained electrochemical data including the values of charge transfer resistance, coating resistance, low frequency impedance and corrosion current density showed that the silane sol gel film in the presence of clay nanoparticles can present an improved corrosion protection. The behavior was connected to an enhancement in the coating barrier properties. Moreover, FESEM and water contact angle confirmed the higher reticulation in case of the coating incorporating nanoclay.

Organic coatings are the single most widely applied materials to protect metallic substrates against corrosion. Therefore, coating researchers need to understand how a coating can guarantee protective performance during service life. This study it is tried to find how adhesion durability can affect the protective performance of a coating. An epoxy resin (Araldite GY 783) was cured with a mixture of two types of hardeners (a polyether polyamine and a cycloaliphatic polyamine) in four different mixing ratios (i.e. 20–80, 50–50, 70–30, 90–10) to achieve various adhesion behaviors, water permeability, and viscoelastic properties. Samples were exposed to humidity in the testing chamber for 300 days and adhesion was measured at wet and dry conditions over time. After drying, adhesion loss and recovery were evaluated by a pull-off test. The electrochemical behavior of coatings was studied by electrochemical impedance spectroscopy (EIS). A series of impedance spectra of coatings during exposure to humidity were recorded and their protective properties were compared. The results showed a correlation between protective properties and viscoelastic behavior of coatings. It was found that a sample with a cycloaliphatic hardener has a higher elastic modulus (1275 MPa) and a sample with a polyether polyamine hardener has a lower elastic modulus (465 MPa). Additionally, it was found that a sample with excellent initial protective properties (|Z| =1010 Ω cm2), higher elastic modulus, and low initial water permeability (0.308 g/m2hr) may quickly fail because of the adhesion failure after wet cycles.

not following safety tips during mobile radiography can bring about risks for nurses in ICU wards.
the study aimed to determine the status of personal protection against radiation and its associated factors in nurses working in ICU wards of health care-educational centers affiliated with Guilan University of Medical Sciences in Rasht, Iran.
in this cross-sectional analytical study, the knowledge and performance of 142 nurses in ICU wards were examined in terms of personal protection against radiation as well as the protective equipment and facilities available through census. The data collection instruments included a research-made questionnaire and checklist. The questionnaire consisted of two sections: the first dealt with personal-occupational information, while the second section included 11 four-option questions related to knowledge about protection against radiation. For data analysis, descriptive and inferential statistical indices (mean, standard deviation, Mann-Whitney, Kruskal-Wallis, and logistic regression) were used.
the findings indicated that 64.1% of samples were women, 62.7% were married, and 90.1% had bachelor’s degree. Considering employment status, 52.1% were permanent employed, while 86.6% were in turn taking nurses. A total of 41.5% of samples had a working background of less than 5 years, and 97.9% of them had not participated in any course for protection against radiation. The results also indicated that most samples (62.7%) had poor knowledge about personal protection against radiation, and only 37.3% of samples had medium knowledge, and finally none of them had favorable level of knowledge. None of the ICU wards were equipped with necessary and sufficient equipment, among which only lead divider was sufficiently available in all wards. Regarding the protective performance of samples, the results showed that 100% of samples had a poor performance. There was a significant relationship between the knowledge of protection against radiation and gender (P=0.01), being married (P=0.041), and education (P=0.016). A significant relationship was also observed between the protective performance of samples and gender (P=0.011), training method (P=0.006), and age (P=0.005).
Considering the poor knowledge of the studied samples and inadequacy of equipment regarding protection against radiation, and in response to poor performance, training nurses and equipping the ICU wards seem to be essential.

Due to the adverse effects of exposure to electromagnetic waves on humans and equipment, engineering controls such as the use of shields are one of the best ways to control and reduce exposure to electromagnetic waves. There are various methods to evaluate the performance of electromagnetic shields. The aim of this study was to investigate the effect of shield penetration depth and thickness on the performance of nanocomposites.
In this study, paraffin wax was used as a matrix and black carbon spherical nanoparticles and Fe3O4 were used as filler. Two nanocomposite samples were made with different weight percentages of fillers. The electromagnetic properties of nanocomposites made were measured using a Vector Network Analyzer in the frequency range of 8-12.5 GHz (X) based on the transfer/reflection method. The Delta function was used to evaluate the shielding protective performance at different thicknesses and frequencies.
Based on the weight percentage of nanocomposite constituents, two samples were obtained. The highest penetration depth was observed in FN2 samples. Correlation between free space impedance and shield components was observed at the lowest shield thickness and at the initial frequencies. The lowest delta value was observed in the FN2 sample.
According to the Delta function, by increasing the absorption and decreasing the reflection in the shield, the protective efficiency of the shield increases. Shield thickness and frequency of electromagnetic waves affect the protective performance of the shield. Increasing the match of impedance between free space and shielding material increases the shield efficiency.

One of the approaches for improving the protective performance of silane sol gel coatings is to optimize the application condition and parameters related to the silane solution. The aim of this study is to investigate the effect of aging time of silane solution and dipping duration in the silane solution on anticorrosion function of an eco-friendly hybrid coating applied on stainless steel 304L. The results of electrochemical impedance spectroscopy (EIS) clearly indicated that the barrier and protective properties of silane coatings were affected by variation of the two parameters. In order to study the morphology, topography and roughness of the hybrid coatings, atomic force microscopy (AFM) and field emission scanning electron microscopy (FESEM) were used. The results of the electrochemical measurements and surface analysis revealed that that the most protective coating was obtained after 1 -s dipping of the metallic sample in the silane solution with no aging.

The incorporation of anticorrosion pigments into the coating formulation is one of the most effective approaches to enhance the resistance against cathodic disbonding. Accordingly، new generations of phosphate-based anticorrosion pigments could be used to improve inhibition efficiency of zinc phosphate pigment as a conventional alternative to toxic chromates. In addition to studying the role of zinc aluminum phosphate، which represents the second generation of phosphate-based anticorrosion pigments in the protective performance of an epoxy-polyamide coating through electrochemical noise method، this paper intends to investigate the effect of the modification of zinc phosphate pigment on the resistance to cathodic disbonding. In the presence of the modified pigment، the improved adhesion strength and decreased disbonding rate were connected to local pH control in the disbonding front and the precipitation of a protective layer، confirmed by electrochemical impedance spectroscopy parameters. Although elevated temperature and more cathodic potential accelerated coating disbondment، zinc aluminum phosphate still revealed superior performance in strengthening the adhesion between the anticorrosive coating and steel substrate and enhancing the resistance against cathodic disbonding.

School of Metallurgy and Materials Engineering, College of Engineering, University of Tehran, Tehran The paper intends to introduce innovations in the field of silane based coatings. Although the coatings are generally thin, they are able to provide a desirable corrosion protection. Hence, they could be taken into account as proper alternative for toxic chromate conversion coatings. In addition to protective action, silane layer can facilitate an excellent adhesion for the covering coating through covalent bonds. In spite of barrier properties, the coatings would fail to reveal active protection in case of introducing cracks or failures. Main aim of the paper is to introduce some novel approaches to improve protective performance of silane based coatings.

Self doped polyaniline-clay nanocomposite was synthesized via copolymerization of aniline and 3-amino benzene sulfonic acid with ammonium peroxydisulfate in ScCO2 in the presence of Cloisite 30B nano-clay. Self doped polyaniline was sunthesized in the same procedure. The synthesized self doped polyaniline and self doped polyaniline-clay nanocomposite were added into the epoxy and zinc rich epoxy coatings, separately. Corrosion protective properties of synthesized products were analyzed via determination of water vapor transmission and determining free corrosion potential (Ecorr.) and electrochemical impedance spectroscopy. Results revealed that the best protective performances were achieved by using self doped polyaniline-clay nanocomposite. J. Color Sci. Tech. 7(2014), 275-280©. Institute for Color Science and Technology.

Surge arresters are used to protection of high voltage equipment and power transmission lines. Due to the presence or absence of shielding wire in transmission lines, surge arresters play an important role in reducing overvoltages. In this paper, the performance of an external gap arrester is investigated by considering different values of ground resistance and also the effect of soil ionization. The effect of lightning strike parameters such as rise time and tail time on overvoltage, insulator failure and energy absorbed in surge arrester for 63 kV transmission line without shielding wire has been simulated and studied in EMTP-ATP software. Considering the effect of the ground system, the use of external gap line arresters has provided better results compared to conventional arresters. Also, the surge arresters in the transmission line with shielding wire have a different operation from the transmission line without it. The results show that the surge arrester with an external gap compared to the surge arrester without gap has a better protective performance in absorbing energy and reducing overvoltage in this type of transmission line.