scholarly journals Atomic Scale Insight into Corrosion Inhibition: DFT Study of 2-Mercaptobenzimidazole on Locally De-Passivated Copper Surfaces

2021 ◽  
Author(s):  
Fatah Chiter ◽  
Dominique Costa ◽  
Vincent Maurice ◽  
Philippe Marcus
Keyword(s):  
Metal Surface ◽  
Barrier Properties ◽  
Copper Surface ◽  
Atomic Scale ◽  
Localized Corrosion ◽  
Oxide Surface ◽  
Organic Film ◽  
Copper Surfaces ◽  
Significant Difference ◽  
Key Factor

Abstract A key factor for effective inhibition by organic molecules of the initiation of localized corrosion by pitting is their ability to form a protective organic film in locally de-passivated zones exposing the bare metal next to the oxide-covered surface. Herein, based on quantum chemical DFT calculations, we study the chemistry of the interface between 2-mercaptobenzimidazole (MBI) and a copper surface partially covered by a Cu2O passive oxide film. The results show the adaptability of the molecule to adsorb strongly on the different zones, oxide or metal, of a locally de-passivated surface. However, differences in the local adsorption configurations, involving covalent bonding with H-bonding depending on oxide or metal and on conformer, thione or thiolate, lead to the formation of an inhomogeneous organic film. Increasing order of local adsorption strength is oxide walls < metal surface < oxide surface < oxide edges for the thione species, whereas there is no significant difference of local adsorption strength for the thiolate species. Our results suggest that both species of MBI can heal the oxygen and copper low coordinated sites as well as can protect the exposed metal surface, thus enhancing the barrier properties of the passivated surface even when locally defective.

scholarly journals Corrosion inhibition of locally de-passivated surfaces by DFT study of 2-mercaptobenzothiazole on copper

2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Fatah Chiter ◽  
Dominique Costa ◽  
Vincent Maurice ◽  
Philippe Marcus
Keyword(s):  
Metal Surface ◽  
Barrier Properties ◽  
Copper Surface ◽  
Atomic Scale ◽  
Localized Corrosion ◽  
Oxide Surface ◽  
Protection Efficiency ◽  
Surface Areas ◽  
Organic Inhibitors ◽  
Quantum Chemical Dft Calculations

AbstractInvestigating the interaction of organic inhibitors with metal and alloy surfaces is crucial for an atomic-scale understanding of their protection efficiency, particularly on the initiation of localized corrosion by pitting. Quantum chemical DFT calculations were performed to optimize the constructed model of a depassivated copper surface and to study the adsorption of 2-mercaptobenzothiazole (MBT), on different zones exposed by local depassivation. Reactive sites exist at the metal surface, at the oxide surface, as well as on the oxide edges and oxide walls. The surface-reactive sites are the unsaturated and saturated copper atoms and singly and doubly unsaturated oxygen atoms of the oxide, and the copper atoms of the metal. The sulfur (Sexo and Sendo) and nitrogen (N or NH) atoms are the reactive sites in the molecules. MBT can covalently bond to the oxide surface as well as to the oxide edges, oxide walls, and metal surface exposed by depassivation. For the thione species, local adsorption strength decreases as oxide edges > oxide surface > metal surface > oxide walls, suggesting that MBT heals the low coordinated sites. For the thiolate species, adsorption strength is similar on the different area, except the oxide walls. The results show the ability of the inhibitor to interact on different zones of a locally depassivated surface and to form a strongly adsorbed organic film, which can block the initiation of localized corrosion by enhancing the interfacial barrier properties, including in the local surface areas incompletely passivated or locally damaged by depassivation.

Influence of natural organic matter on the morphology of corroding copper surface

1994 ◽  
Vol 52 ◽  
pp. 678-679
Author(s):  
G. V. Korshin ◽  
J. F. Ferguson ◽  
M. E. Rock
Keyword(s):  
Organic Matter ◽  
Natural Organic Matter ◽  
Natural Waters ◽  
Copper Surface ◽  
Metal Corrosion ◽  
Localized Corrosion ◽  
Corrosion Attack ◽  
Copper Surfaces ◽  
Mineralized Water ◽  
Polymeric Species

Natural organic matter (NOM) is a ubiquitous and important component of natural waters. Polymeric species related to humus found in soils constitute the major part of NOM. NOM is of major importance for the speciation of metals in waters but its effects on metal corrosion are little known. The influence of NOM on the morphology of corroding copper surfaces is discussed in this communication. The studies were performed for copper coupons exposed for 7 weeks to waters supporting an intense localized corrosion attack called pitting. Two types of waters were used: highly mineralized water at pH close to 7.3 (water A) and soft water at pH close to 9.3 (water B). The morphology of the surface was examined using conventional photography and SEM (JEOL 5200). The range of accelerating voltages was from 10 to 25 kV.Profound effects of NOM on the state of the corroding copper surface were found.

scholarly journals Simulation and surface topology of activity of pyrazoloquinoline derivatives as corrosion inhibitor on the copper surfaces

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Razieh Razavi ◽  
Savaş Kaya ◽  
Mahboobeh Zahedifar ◽  
Sayed Ali Ahmadi
Keyword(s):  
Metal Surface ◽  
Profile Analysis ◽  
Aqueous Media ◽  
Copper Surface ◽  
Molecular Structures ◽  
Surface Topology ◽  
Bond Critical Point ◽  
Inhibitor Molecule ◽  
Copper Surfaces ◽  
Inhibition Performance

AbstractIn the present study, corrosion inhibition performances of some pyrazolo [3,4-b] quinoline-3,5-dione derivatives against the corrosion of copper metal were investigated using B3LYP/6-311++g(d,p) calculation level in aqueous media. Additionally, interaction energies were calculated for all the pyrazoloquinoline derivatives compounds. In the calculations it is observed that studied molecules adsorb on metal surface with the help of electron donor heteroatoms in their molecular structures. Chemical thermodynamic parameters regarding the interaction between inhibitor molecule and copper surface were estimated and discussed. Density of the electron profile analysis and chemical electrostatic potential of nuclear charges in the molecule were applied to consider the nature of a number of probable interactions between Cu metal surface and inhibitors in terms of bond critical point (BCP). Calculated quantum chemical parameters showed that the pyrazoloquinoline derivatives including the OH and NO2 exhibit high inhibition performance.

scholarly journals Development of Copper Hatch Baskets and Evaluation of the Productive Indexes of a Commercial Hatchery

2020 ◽  
Vol 48 ◽  
Author(s):  
Ronise Faria Rohde Depner ◽  
Vivian Lucca ◽  
Rômulo Alexandre Depner ◽  
Karine Patrin Pontin ◽  
Luciana Pötter ◽  
...  
Keyword(s):  
Adverse Effects ◽  
Copper Alloys ◽  
Antimicrobial Properties ◽  
Test Group ◽  
Copper Surface ◽  
Control Group ◽  
Copper Surfaces ◽  
Significant Difference ◽  
Bacteria And Fungi ◽  
Cleaning And Disinfection

Background: The dissemination of pathogenic microorganisms in hatcheries leads to a higher number of contaminated eggs, causing reduction in hatchability and increase of discarded chicks. Sanitation programs are crucial for maximum hatchability and chick quality. Efforts have been made to find alternative approaches to the conventional disinfectants, and surfaces with copper, which have antimicrobial properties, could assist in this process. However, the possible adverse effects of copper surfaces on chicks in hatcheries have not yet been evaluated. The present study aimed at developing hatch baskets composed of copper and evaluating the effect of these baskets on the productive indexes of a hatchery.Materials, Methods and Results: For this experiment, 3.15 kg hatch tray prototypes with 99.9% Cu (Cu11000) were developed to fit inside conventional polypropylene hatch baskets (580 × 755 × 83 mm). Six polypropylene hatch baskets (control group) and 6 polypropylene hatch baskets covered by 99.9% copper (Cu11000) hatch trays (test group) were evaluated during 5 hatchings. Hatched eggs and chicks remained in contact with the hatch basket surfaces for at least 72 h, corresponding to the entire period in which they were located in the hatcher. Cleaning and disinfection programs of the hatchery were not modified. The level of microbial contamination on the hatch baskets was evaluated at 6 different periods: 0 h (initial contamination after disinfection and egg transfer to the trays); 24 h, 30 h, 45 h and 60 h after the first sampling; and at the moment when chicks were removed from the hatching cabinet and transferred to the chick-holding room (> 60 h). Counting of total moulds and yeasts, mesophilic microorganisms, Enterobacteria and Escherichia coli colonies was performed. The number of hatched chicks, non-hatched eggs, and chicks discarded were registered for each hatching. Microbiologic analyses showed no growth on hatch baskets neither of the test group nor on those of the control group, regardless of the period evaluated. No significant difference was found between the two groups in the counts of hatched chicks, non-hatched eggs, and chicks discarded. Discussion: The antimicrobial efficacy of copper surfaces has been established for a variety of bacteria and fungi, including in the healthcare environment. In addition, antimicrobial resistance to copper is extremely rare because of copper’s multisite kill mechanism and other mostly nonspecific damage mechanisms. Several copper applications have been established; however, the potential adverse effects of using copper surfaces in hatcheries on chicks or on hatchery productive indexes had not yet been evaluated. The analyses performed in this study did not show microbiological growth. The results showed that the copper surface did not cause any significant adverse effects on chicks. The hatched chicks were visually healthy, and no significant difference was found between the numbers of chicks discarded in the control and test groups. Since the production parameters were not altered or impaired in the present study, it is possible to conclude that the use of copper surfaces in hatcheries can be an effective tool in the microbiological control of these environments. Nevertheless, copper alloys lend themselves to the creation of self-sanitizing surfaces that should be used as a complement and not as a substitute for standard cleaning and disinfection practices.

The Use of Ratio-Recording Interferometry for the Measurement of Infrared Emission Spectra: Applications to Oxide Films on Copper Surfaces

1975 ◽  
Vol 29 (6) ◽  
pp. 496-500 ◽  
Author(s):  
D. Kember ◽  
N. Sheppard
Keyword(s):  
Emission Spectra ◽  
Black Body ◽  
Infrared Emission ◽  
Thin Layers ◽  
Oxide Surface ◽  
Surface Layers ◽  
Selective Reflection ◽  
Copper Surfaces ◽  
Emission And Absorption Spectra ◽  
Direct Correspondence

Infrared emission spectra from metal samples with oxide surface layers are shown to be very advantageously studied using the spectrum-ratioing facility of a recording infrared interferometer. The emission from a given sample is ratioed against that from a black-body emitter at the same temperature so as to give emittance as a function of wavenumber directly. This method has very useful application to irregularly shaped metal emitters. In the absence of selective reflection there is a direct correspondence between emission and absorption spectra for thin layers of an emitting substance. However, the presence of selective reflection leads to reduced emission and to considerable differences in the appearance of “absorption” and emission spectra in regions of strong absorption. Emission spectra obtained from copper plates heated, above 150°C, for different periods in air are shown clearly to indicate the presence of cuprous, Cu(I), and cupric, Cu(II), oxides in the surface layer.

scholarly journals PSIII-5 Effects of ingredient composition of oral drenches in small piglets post-farrowing on average daily gain and pre-wean mortality

2020 ◽  
Vol 98 (Supplement_3) ◽  
pp. 238-238
Author(s):  
Olivia Harrison ◽  
Samantha Tauer ◽  
Brent Frederick
Keyword(s):  
Birth Weight ◽  
Average Daily Gain ◽  
High Energy ◽  
Experimental Unit ◽  
Swine Industry ◽  
Bioactive Proteins ◽  
Randomized Design ◽  
Significant Difference ◽  
Key Factor ◽  
Daily Gain

Abstract Number of pigs born alive has been a key factor of the increasing efficiency of the U.S. swine industry. However, with increased pigs in the uterus, birth weight has been negatively impacted, with more small or at-risk pigs being born per litter. In order to overcome these changes, a study testing three commercial oral drenches against a control to determine which would increase average daily gain and decrease preweaning mortality. In a completely randomized design, 877 one-day-old suckling pigs from a high-health farm were selected for the experiment if they appeared to be in the bottom 20% of bodyweight compared to their contemporaries. Selected pigs were given one of four drenching treatments: 1) none (control), 2) bioactive proteins (BP), 3) high energy sugars (HES), and 4) immunoglobulins (IgY). Pigs were weighed on d 1 and d 19 of age (weaning), with mortality tracked during the suckling period. Data were analyzed using SAS v 9.4 (Cary, NC), with pig as the experimental unit and an accepted alpha of 0.05. Treatment had no detected effect on birth weight, weaning weight, ADG, or mortality (P = 0.79, 0.96, 0.86, 0.38 respectively). Likewise, statistical contrasts were used to determine there was no detected impact (P &gt; 0.10) of drench, regardless of type, compared to the control in any measured response criteria. Interesting, pigs drenched with BP or IgY had numerically lower preweaning mortality (11.2 and 11.5% respectively), than those administered the control or HES (15.4 and 15.2%, respectively). In conclusion, this experiment showed no significant difference in the performance between piglets given no product vs. those drenched with bioactive proteins, high energy sugars, or immunoglobulins. However, additional research is warranted with greater replication or disease stressors to better understand if oral drenches may improve preweaning performance or mortality in different situations.

scholarly journals Acceptability of a Sublingual Drug Formulation for Respiratory Tract Infections in Children Aged 3 to 5 Years

Pharmaceutics ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 294
Author(s):  
Andrzej Emeryk ◽  
Thibault Vallet ◽  
Ewelina Wawryk-Gawda ◽  
Arkadiusz Jędrzejewski ◽  
Frederic Durmont ◽  
...  
Keyword(s):  
Respiratory Tract ◽  
Respiratory Tract Infections ◽  
Drug Formulation ◽  
Reference Framework ◽  
Significant Difference ◽  
Key Factor ◽  
Treatment Safety ◽  
The Many ◽  
Tract Infections ◽  
Recurrent Respiratory Tract Infections

In pediatrics, acceptability has emerged as a key factor for compliance, and consequently for treatment safety and efficacy. Polyvalent mechanical bacterial lysate (PMBL) in 50-mg sublingual tablets is indicated in children and adults for the prophylaxis of recurrent respiratory tract infections. This medication may be prescribed in children over 3 years of age; the appropriateness of this sublingual formulation should thus be demonstrated amongst young children. Using a multivariate approach integrating the many aspects of acceptability, standardized observer reports were collected for medication intake over the course of treatment (days 1, 2, and 10) in 37 patients aged 3 to 5 years, and then analyzed in an intelligible model: the acceptability reference framework. According to this multidimensional model, 50-mg PMBL sublingual tablets were classified as “positively accepted” in children aged 3 to 5 years on all three days of evaluation. As the acceptability evaluation should be relative, we demonstrated that there was no significant difference between the acceptability of these sublingual tablets and a score reflecting the average acceptability of oral/buccal medicines in preschoolers. These results highlight that sublingual formulations could be appropriate for use in preschoolers.

scholarly journals Emotional Processing In Patients with Ischemic Heart Diseases

2018 ◽  
Vol 6 (9) ◽  
pp. 1627-1632
Author(s):  
Shirali Kharamin ◽  
Mohammad Malekzadeh ◽  
Arash Aria ◽  
Hamide Ashraf ◽  
Hamid Reza Ghafarian Shirazi
Keyword(s):  
Cardiovascular Disease ◽  
Emotional Processing ◽  
Heart Diseases ◽  
Public Health Problem ◽  
Ischemic Heart ◽  
Control Group ◽  
Stress Appraisal ◽  
Processing Styles ◽  
Significant Difference ◽  
Key Factor

BACKGROUND: Cardiovascular disease is the most prevalent public health problem on a worldwide scale, and ischemic heart disease accounts for approximately one-half of these events in high-income countries. One of the most important risk factors for this disease is mental and psychological especially stressful experiences. AIM: This research was established to compare emotional processing, as a key factor in stress appraisal, between IHD patients and people with no cardiovascular disease. METHODS: Using simple sampling, fifty patients were selected from people who diagnosed as IHD in the hospital and referred for treatment after discharging care and treatment. Control group participants were selected as control group peoples, using neighbourhood controls selection. The Emotional Processing Scale was filled by all members of the two groups. RESULTS: There were significant differences between the two groups on the EPS-25 total scores, as well as on emotional processing dimensions of signs of unprocessed emotion, unregulated emotion; avoidance and impoverished. Also, there was no significant difference between the two groups in the dimension of Suppression. The final step of regression revealed a β of 10.15 and 1.05 for AVO and IEE subscales respectively. CONCLUSION: The result showed that patients with IHD are using more negative emotional processing styles.

scholarly journals Key Factors of Sustainability for Smartphones Based on Taiwanese Consumers’ Perceived Values

2018 ◽  
Vol 10 (12) ◽  
pp. 4446 ◽  
Author(s):  
Jui-Che Tu ◽  
Xiu-Yue Zhang ◽  
Sin-Yi Huang
Keyword(s):  
Service Quality ◽  
Purchase Intention ◽  
Perceived Value ◽  
Income Level ◽  
Demographic Variables ◽  
Key Factors ◽  
Significant Difference ◽  
Perceived Values ◽  
Perceived Price ◽  
Key Factor

The rapid growth of smartphones over recent decades has brought a large amount of e-waste as well as an increased carbon footprint. Facing severe environmental issues, sustainable development of smartphones has become a particularly important public concern. The main aim of this study was to clarify the key factor of sustainability for smartphones based on Taiwanese consumers’ perceived values. Apple’s iPhone was taken as an example. First, key factors of perception that smartphone consumers valued the most in terms of sustainable practice were extracted through a factor analysis. Second, demographic differences related to these key factors were investigated through t-test and one-way ANOVA analyses; demographic variables were gender, age, education level, occupation, and income level. The results were as follows: (1) the key factors were “recognition”, “brand advantage”, “service quality”, “usage period”, and “perceived price”; (2) there was a significant difference between genders on the key factors of perceived value (“recognition”, “brand advantage”, and “perceived price”). Specifically, females have higher perceived values of “recognition”, “brand advantage”, and “perceived price” than males; (3) there was a significant effect of income level on the key factor (“perceived price”) of perceived value. Specifically, respondents with an income level of NTD15,001–30,000 had a higher perceived value of “perceived price” than respondents earning NTD30,001–45,000. Among the five key factors, “recognition” and “brand advantage” are primary factors influencing purchase motivation; “recognition”, “brand advantage”, and “service quality” are primary factors that could influence brand loyalty; “perceived price” is the primary factor that affects purchase intention. This study contributes to the green market segmentation of smartphones. The limitations of the study relate to the size and distribution of the samples.

Sign in / Sign up

Export Citation Format

Share Document