scholarly journals Research on Inhibiting Performance of Compound Corrosion Inhibitors Based on Nitrite

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Bing Yi ◽  
Jianmin Wang ◽  
Liyu Feng ◽  
Yilin Song ◽  
Junzhe Liu ◽  
...  

To solve rebar corrosion in existing concrete structures, two test methods, adding corrosion inhibitors into concrete and applying corrosion inhibitors on the existing concrete surface by brushing and pouring and composite repair, combined with natural potential, XRD and SEM, were used to comprehensively evaluate the performance of nitrite-based compound corrosion inhibitors. The research results show that nitrite has a better inhibitory effect than phosphate, and when the respective mass fraction of hydrogen phosphate and sodium nitrite is about 1.5%, the rust inhibition effect is the optimum. Brushing, perfusion, and composite repair can all play a good role in inhibiting corrosion of which composite repair is the best. The addition of phosphate can improve the macrocell corrosion caused by the low dosage or uneven distribution of nitrite.

2021 ◽  
Vol 67 (2) ◽  
pp. 3453-3464
Author(s):  
Evelin Korcz ◽  
László Varga ◽  
Zoltán Kerényi

Serratia species are opportunistic pathogenic microorganisms primarily known as nosocomial infectious agents, which can also cause food quality problems. The appearance of the extracellular pigment-producing Serratia marcescens in cow’s milk causes its red discoloration, posing a challenge to the dairy industry and food certification laboratories. The detection of the bacterium by conventional procedures based on microbiological methods is time-consuming and labor-intensive, and in many cases does not lead to satisfactory results due to the competitive inhibitory effect of the accompanying microflora. Following the analysis of the relevant literature, the published endpoint PCR methods and the primers used for the detection of S. marcescens were evaluated in in silico and in vitro assays, and then the procedure was tested on farm milk samples. Using the method, a total of 60 raw and pasteurized milk samples were analyzed, more than half of which (i.e., 32) were identified as S. marcescens positive. The significance of our work is mainly represented by the application of the published test methods in food industry practice. Our results highlight to the importance of detecting this bacterial species.


2016 ◽  
Vol 51 (12) ◽  
pp. 1929-1936 ◽  
Author(s):  
Raquel Villamizar-Gallardo ◽  
Johann Faccelo Osma Cruz ◽  
Oscar Orlando Ortíz-Rodriguez

Abstract: The objective of this work was to evaluate the microbicidal effect of silver nanoparticles (AgNPs) on potentially toxigenic fungi affecting cocoa (Theobroma cacao) crops. These fungi, isolated from diseased cocoa pods, were characterized phenotypically and genotypically. The microbicidal effect was assessed by measuring radial mycelial growth, in synthetic culture media, and at different AgNP concentrations in plant tissues. The inhibition effect was monitored in Petri dishes, and changes in fungal structures were observed through scanning electron microscopy. Two potentially toxigenic fungi were highly prevalent: Aspergillus flavus and Fusarium solani. The inhibition assays, performed in liquid and solid synthetic culture media, showed that AgNPs did not significantly affect the growth of these fungi, even at the highest concentration (100 ppm). By contrast, they showed a positive inhibitory effect in plant tissues, especially in the cortex, when infected with A. flavus, in which an 80 ppm dose completely inhibited fungal growth. However, once fungi have managed to penetrate inside the pods, their growth is unavoidable, and AgNP effect is reduced. On F. solani, the studied nanomaterial only induced some texture and pigmentation changes. The microbicidal effect of chemically synthesized silver nanoparticles is greater in plant tissues than in culture media.


2015 ◽  
Vol 12 (3) ◽  
pp. 479-484
Author(s):  
Baghdad Science Journal

In this study Candida speices was diagnosed in 26 swab samples from patients with denture stomatitis , investigates the antagonism activity of Lactobacillus was investigated against the yeast of Candida albicans in vitro.Results revealed that The inhibition effect of Lactic Acid Bacteria against C.albicans was examined in solid medium, L.plantarum gave higher inhibition average 11mm followed by L.acidophillus with average 9 mm and, L.fermentum , L.casei with averages 7 mm. Whereas the filtrates, the highest inhibition zone were 20 and 16 mm by L. plantarum and L.acidophillus, respectively.


2013 ◽  
Vol 686 ◽  
pp. 266-272 ◽  
Author(s):  
Syarizal Fonna ◽  
M. Ridha ◽  
Syifaul Huzni ◽  
Ahmad Kamal Ariffin

Particle Swarm Optimization (PSO) has been applied as optimization tool in various engineering problems. Inverse analysis is one of the potential application fields for PSO. In this research, the behavior of PSO, related to its inertia weight, in boundary element inverse analysis for detecting corrosion of rebar in concrete is studied. Boundary element inverse analysis was developed by combining BEM and PSO. The inverse analysis is carried out by means of minimizing a cost function. The cost function is a residual between the calculated and measured potentials on the concrete surface. The calculated potentials are obtained by solving the Laplace’s equation using BEM. PSO is used to minimize the cost function. Thus, the corrosion profile of concrete steel, such as location and size, can be detected. Variation in its inertia weight was applied to analyze the behavior of PSO for inverse analysis. The numerical simulation results show that PSO can be used for the inverse analysis for detecting rebar corrosion by combining with BEM. Also, it shows different behavior in minimizing cost function depending on inertia weight.


1979 ◽  
Author(s):  
L F. Mockros ◽  
S.D. Hirson ◽  
L. Zuckerman ◽  
J.A. Caprini ◽  
W.P. Robinson ◽  
...  

Anticoagulation (AC) levels were monitored simultaneously in dogs by 3 whole blood (WB) and 2 plasma CP) clotting assays. Three levels of heparin (50,100 and 200 U/kg were tested in 26 experiments by Intravenous injection. Blood was sampled at 10 and 30 min then repeated every 30 min for 4 hours. The WB clotting tests provided more sensitivity with respect to the kinetics of neutralization of the heparin than did the P assays. The levels of AC determined by each assay method was fit to exponential curves using a computerized iterative least squares method. The points were weighted inversely with the variance and the censored data was used by fitting the known values to a gamma distribution and deriving the average and SEN of the series. The coagulation curves were dependent upon the heparin dose and test methods. Extrapolated levels of initial AC demonstrate from 3 to 67 fold increases in relative clotting times for 50 and 200 U/kg dosages respectively, depending on the assay method. The AC half lives (T½) with the three WB assays varied from 15 to 41 min for the low dosage and 24 to 34 min and 27 to 30 min for 100 and 200 U/kg dosages respectively. The shortness of these T½ is a consequence-of using data acquired at 10 to 30 tnin post injection. Reanalysis of our data using sampling periods >60 min significantly prolonged the derived T½. Finally there was a marked post heparin shortening (less than pre-heparin values) of the WB assays at 2-4 hours. The values appeared to be dose dependent, as the shortest values occurred In those animals receiving the highest heparin dose. Therefore, intravenous heparin can be associated with high Initial AC followed within 2-4 hours by a quicker than normal clot time.


2020 ◽  
Vol 312 ◽  
pp. 113436 ◽  
Author(s):  
Jinghui Wang ◽  
Dan Liu ◽  
Shuyun Cao ◽  
Shiguang Pan ◽  
Hengzhi Luo ◽  
...  

2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Bihui Liu ◽  
Xin Yang ◽  
Liujin Guo ◽  
Jing Zhang ◽  
Xianrong Zhou ◽  
...  

Sichuan pickles (Paocai) are a traditional Chinese fermented vegetable food that is rich in beneficial microorganisms. In this study, the inhibition of constipation by Lactobacillus plantarum CQPC02 (LP-CQPC02) isolated from Sichuan Paocai was studied by establishing a constipation model of mice using activated carbon. The constipation inhibition effect of LP-CQPC02 was determined by observing the defecation of mice, rate of active carbon propulsion, pathological section observation, serum index, and small intestinal mRNA expression. The results showed that LP-CQPC02 inhibited the decrease in body weight caused by constipation in mice. At the same time, LP-CQPC02 also increased the propulsion rate of activated carbon in the small intestine and shortened the time of discharge for the first black stool. LP-CQPC02 increased gastrin (Gas), motilin (MTL), endothelin (ET), and acetylcholinesterase (AChE) in constipated mice, and it also decreased the level of somatostatin (SS). qPCR results showed that LP-CQPC02 upregulated the expression of c-Kit, stem cell factor (SCF), and glial cell-derived neurotrophic factor (GDNF) and downregulated the expression of transient receptor potential cation channel subfamily V member 1 (TRPV1) and inducible nitric oxide synthase (iNOS) in mice with constipation, and a stronger effect was observed with a high concentration of LP-CQPC02. The experimental results showed that LP-CQPC02 has a stronger constipation inhibitory effect than the commonly used commercial Lactobacillus delbrueckii subsp. bulgaricus (LB), and the inhibitory effect of LP-CQPC02 on constipation increases with increasing concentration of LP-CQPC02. Therefore, LP-CQPC02 is a high-quality microbial resource with a good constipation inhibition effect and probiotic potential.


2019 ◽  
Vol 814 ◽  
pp. 499-504
Author(s):  
Ren Jun Xu ◽  
Hua Lei He ◽  
Ying Li Tang ◽  
Min Lan Gao ◽  
Hai Peng Hui ◽  
...  

Ligustrum vulgare is an evergreen tree. The leaves are opposite, glossy dark green, 6–17 centimetres (2.4–6.7 in) long and 3–8 centimetres (1.2–3.1 in) broad. The ligustrum vulgare leaves contain two main components, one of which is oleanolic acid and the other is p-hydroxyphenylethanol which indicates its extracts suitable to be used as an effective corrosion inhibitor. Extracts of ligustrum vulgare leaves (PE) were modified with hydroxymethylation reaction (PM1) and Mannich reaction (PM2) to produce the relative stable green acidic corrosion inhibitors. The extracts of ligustrum vulgare leaves have been investigated on the corrosion inhibition of A3 steel with weight loss. The results show that these inhibitors have good corrosion inhibition effect on A3 steel. The PM2 are the most effective for corrosion inhibition, and the inhibition efficiency can reach 75.95%. When the temperature is 60°C, the corrosion inhibition rate of PE, PM1, PM2 is only 24.46%, 42.35% and 39.35% respectively which can not effectively prevent the corrosion of the metal. And the extracts inhibit corrosion mainly by adsorption mechanism. This adsorption accords with Langmuir adsorption isotherm.


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