scholarly journals Adsorption Aspects, Inhibitory Properties and a Study of Surface Corrosion of Carbon Steel in Acidic Media

2016 ◽  
Vol 10 (10) ◽  
pp. 82 ◽  
Author(s):  
Qhatan, A. Yousif ◽  
Adel, A. Al-Zhara
Keyword(s):  
Carbon Steel ◽  
Protective Layer ◽  
Steel Electrode ◽  
Adsorption Models ◽  
Isotherm Equation ◽  
Surface Corrosion ◽  
Langmuir Isotherm Equation ◽  
The Impact ◽  
Mixed Type Inhibitor

The impact of cupral compound on steel in presence of deaerated 0.25 M H2SO4 and 0.5M HClacidic solutions at 298.15K was examined by employing electrochemical measurements. It has been observed that the corrosion efficiency increased by increasing of cupral concentration of the corrosion inhibitor and this enhanced the inhibitory action as mixed type inhibitor. Several different adsorption models were examined which indicate the adsorption of cupral compound as inhibitor on the carbon steel electrode surface follows the Langmuir isotherm equation. The thermodynamic factors governing adsorption, as well as the parameters of kinetics corrosion have been estimated. The role of nanosilica has been observed to reduce the values of current density of corrosion process and this was confirmed by study the surface morphology of electrode via SEM-EDX and AFM techniques by formation a protective layer on carbon steel electrode.

The corrosion inhibition of carbon steel in 5 per cent HCl by Momordica charantia extract

2014 ◽  
Vol 61 (4) ◽  
pp. 255-260 ◽  
Author(s):  
Xie Xuejun* ◽  
Xiao Peng* ◽  
He Jie ◽  
Xiao Wen ◽  
Fu Qiang ◽  
...  
Keyword(s):  
Carbon Steel ◽  
Mixed Type ◽  
Inhibition Efficiency ◽  
Xps Analysis ◽  
Content Type ◽  
Isotherm Equation ◽  
Inhibition Effect ◽  
Langmuir Isotherm Equation ◽  
Ir Analysis ◽  
Mixed Type Inhibitor

Purpose – To study the inhibition effect and mechanism of the Momordica charantia extract (BM) to 20 A carbon steel in 5 per cent HCl. Design/methodology/approach – The weight loss, polarization curve, infrared spectrum (IR) analysis and X-ray photoelectron spectrum (XPS) analysis were carefully investigated to indicate the inhibition effect and mechanism of the BM to 20 A carbon steel in 5 per cent HCl. Findings – BM was composed of C, N and O. Functional groups such as N–H and C=O were found in BM. The inhibition efficiency increased with the increasing concentration of BM. BM behaved as a mixed-type inhibitor, and the inhibition of BM to 20 A carbon steel might be its adsorption through the coordinate covalent bonding among the lone pair electrons of N and O and the empty 3d orbits of Fe, and the adsorption on the surface of 20 A carbon steel obeyed the Langmuir isotherm equation. Research limitations/implications – The inhibition of the BM to 20 A carbon steel in 5 per cent HCl. Practical implications – BM could be used in 5 per cent HCl to prevent 20 A carbon steel from corrosion. Social implications – BM could be used in the chemical cleaning of the boilers to prevent the thermal equipments from corrosion. Originality/value – The inhibition effect and mechanism of the BM to 20 A carbon steel were studied by the weight loss, polarization curve, IR analysis and XPS analysis. BM was composed of C, N and O. Functional groups such as N–H and C=O were found in BM. BM behaved as a mixed-type inhibitor. The inhibition efficiency increased with the increasing concentration of BM, and the adsorption on the surface of 20 A carbon steel obeyed the Langmuir isotherm equation.

scholarly journals Antibacterial Inhibitor as an Expired Metoclopramide in 0.5M Phosphoric Acid

2019 ◽  
Vol 15 (1) ◽  
pp. 71-81 ◽  
Author(s):  
Rana Afif Anaee ◽  
Majed Hameed Abd Al-Majeed ◽  
Shaimaa Alaa Naser ◽  
Mustafa M. Kathem ◽  
Omer Akram Ahmed
Keyword(s):  
Carbon Steel ◽  
Langmuir Adsorption Isotherm ◽  
Efficient Inhibitor ◽  
X Ray ◽  
Langmuir Adsorption ◽  
Carbon Steel Surface ◽  
Adsorption Desorption ◽  
Expired Drug ◽  
Mixed Type Inhibitor

Expired drug Metoclopramide was investigated as an antibacterial corrosion inhibitor for carbon steel in 0.5M H3PO4 solution using the electrochemical method at 30oC and 60oC. The results showed that this drug is an efficient inhibitor for carbon steel and the efficiency reached to 82.244 % for 175 ppm at 30oC and 76.146% for 225 ppm at 60oC. The adsorption of drug on carbon steel surface follows Langmuir adsorption isotherm with small values of adsorption-desorption constant. The polarization plots revealed that Metoclopramide acts as mixed-type inhibitor. Some parameters of inhibition process were calculated and discussed. The surface morphology of the carbon steel specimens was analyzed using scanning electron microscope and energy dispersive X-ray analysis. Antibacterial activity of inhibitor was also tested. Fourier-transform infrared (FTIR) spectroscopy confirmed the inhibitive role of Metoclopramide drug.

scholarly journals Role of Apoptosis in Wound Healing and Apoptosis Alterations in Microgravity

2021 ◽  
Vol 9 ◽  
Author(s):  
Stefan Riwaldt ◽  
Thomas J. Corydon ◽  
Desiré Pantalone ◽  
Jayashree Sahana ◽  
Petra Wise ◽  
...  
Keyword(s):  
Wound Healing ◽  
Current Knowledge ◽  
Protective Layer ◽  
Health Concern ◽  
Human Organism ◽  
Impaired Wound Healing ◽  
Cell Lineages ◽  
Space Tourism ◽  
The Impact

Functioning as the outermost self-renewing protective layer of the human organism, skin protects against a multitude of harmful biological and physical stimuli. Consisting of ectodermal, mesenchymal, and neural crest-derived cell lineages, tissue homeostasis, and signal transduction are finely tuned through the interplay of various pathways. A health problem of astronauts in space is skin deterioration. Until today, wound healing has not been considered as a severe health concern for crew members. This can change with deep space exploration missions and commercial spaceflights together with space tourism. Albeit the molecular process of wound healing is not fully elucidated yet, there have been established significant conceptual gains and new scientific methods. Apoptosis, e.g., programmed cell death, enables orchestrated development and cell removal in wounded or infected tissue. Experimental designs utilizing microgravity allow new insights into the role of apoptosis in wound healing. Furthermore, impaired wound healing in unloading conditions would depict a significant challenge in human-crewed exploration space missions. In this review, we provide an overview of alterations in the behavior of cutaneous cell lineages under microgravity in regard to the impact of apoptosis in wound healing. We discuss the current knowledge about wound healing in space and simulated microgravity with respect to apoptosis and available therapeutic strategies.

Preparation of L-Tryptophan Imprinted Polymer Microspheres in Aqueous Media by In Situ Grafting on Surface

2011 ◽  
Vol 306-307 ◽  
pp. 1658-1662
Author(s):  
Jie Ding ◽  
Shuang Shuang Chen ◽  
Xiao Li ◽  
Xiao Guang Ying ◽  
Shang Feng Jiang ◽  
...  
Keyword(s):  
Self Assembly ◽  
Aqueous Media ◽  
Polymer Microspheres ◽  
Imprinted Polymer ◽  
Adsorption Models ◽  
Functional Monomers ◽  
Isotherm Equation ◽  
Porous Microspheres ◽  
Langmuir Isotherm Equation

In situ grafting on surface was developed to modify porous microspheres. Functional monomers were grafted onto the porous microspheres. The grafting yield was up to 54.6%. The self-assembly of functional monomer and L-tryptophan molecules was verified by UV spectrometry. The surface imprinted polymer microspheres (SMIPs) were synthesized based on the in situ grafting on surface. The competitive binding experiments were carried out to assess the recognition. The results showed good selectivity of the SMIPs towards target molecule. Langmuir and Freundlich adsorption models were applied to description of the experimental adsorption isotherm. The analysis suggested that the adsorbing behavior of SMIPs was in agreement with Langmuir isotherm equation.

Intergroup Threat and Outgroup Attitudes

2013 ◽  
Vol 44 (5) ◽  
pp. 311-319 ◽  
Author(s):  
Marco Brambilla ◽  
David A. Butz
Keyword(s):  
Gay Men ◽  
Social Group ◽  
Welfare Recipients ◽  
Intergroup Attitudes ◽  
Social Policies ◽  
Intergroup Threat ◽  
Economic Threat ◽  
The Impact ◽  
General Climate

Two studies examined the impact of macrolevel symbolic threat on intergroup attitudes. In Study 1 (N = 71), participants exposed to a macrosymbolic threat (vs. nonsymbolic threat and neutral topic) reported less support toward social policies concerning gay men, an outgroup whose stereotypes implies a threat to values, but not toward welfare recipients, a social group whose stereotypes do not imply a threat to values. Study 2 (N = 78) showed that, whereas macrolevel symbolic threat led to less favorable attitudes toward gay men, macroeconomic threat led to less favorable attitudes toward Asians, an outgroup whose stereotypes imply an economic threat. These findings are discussed in terms of their implications for understanding the role of a general climate of threat in shaping intergroup attitudes.

Sign in / Sign up

Export Citation Format

Share Document