377. Corrosion by commercial sodium hypochlorites and its inhibition

Commercial sodium hypochlorites, whether containing KMnO4 or not, are shown to be corrosive at 150 p.p.m. available chlorine and 40° C. to metals such as aluminium, tinned copper, nickel silver and cast stainless steel (18 Cr, 8 Cu, 3 Mo) which are used in dairy equipment. Hypochlorites containing KMnO4 when aged are potentially dangerous to wrought 18/8 stainless steel. The attack is by pitting and therefore especially dangerous to all the metals investigated, and, in general, increases with increase of time of exposure and temperature.Decay of sodium hypochlorite solutions results in conversion of NaOCl to NaCl and NaC103, which reaction is shown to follow a simple equation fairly closely in various storage conditions.Attack on metals by sodium hypochlorite can be efficiently inhibited by addition of sodium silicate, which has a specific action in addition to the effect exerted by increase of alkalinity. NaOH and Na2CO3 additions to the same pH are not so effective and increase attack on aluminium.Increase of pH from 9 to 10·5 by addition of Na2CO3 or sodium silicate reduces bactericidal efficiency of hypochlorites to the same extent.

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A new expansion material used for roof-contacted filling based on smelting slag

Scientific Reports ◽

10.1038/s41598-021-81891-4 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Hua Na ◽

Guocheng Lv ◽

Lijuan Wang ◽

Libing Liao ◽

Dan Zhang ◽

...

Keyword(s):

Mechanical Properties ◽

Hydrogen Peroxide ◽

Compressive Strength ◽

Sodium Silicate ◽

Utilization Rate ◽

Ammonium Bromide ◽

Foaming Agent ◽

Copper Nickel ◽

Smelting Slag ◽

Nickel Smelting

AbstractThe improper handling of smelting slag will seriously pollute the environment, and the unfilled roof of the goaf of the mine will threaten the safety of the mine. Expansion materials have attracted more and more attention because of their excellent properties. In this paper, copper-nickel smelting slag that has some active ingredients of gelling is used instead of traditional aggregate and some part of cement in order to reduce its pollution to the environment and its costs. For safety reasons, hydrogen peroxide was chosen as the foaming agent. Sodium silicate and hexadecyl trimethyl ammonium bromide (CTAB) are used as additives. Our results showed that after 28 days of curing, the material has better mechanical properties and the early compressive strength of the material was enhanced by sodium silicate. The efficiency of foaming was improved by CTAB. It also proves that copper–nickel smelting slag can be used in expansion material. At the same time, the utilization rate of the copper–nickel smelting slag of this formula can reach 70%, reduce its pollution to the environment.

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Measurement of Dynamic Fracture Toughness of 13% Cr Cast Stainless Steel by Instrumented Charpy Test

Tetsu-to-Hagane ◽

10.2355/tetsutohagane1955.65.9_1460 ◽

1979 ◽

Vol 65 (9) ◽

pp. 1460-1461 ◽

Cited By ~ 3

Author(s):

Toshiro KOBAYASHI

Keyword(s):

Fracture Toughness ◽

Stainless Steel ◽

Dynamic Fracture ◽

Dynamic Fracture Toughness ◽

Charpy Test ◽

Cast Stainless Steel

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FEM Simulation of Waves Excited by Array Probe Propagating in Centrifugally Cast Stainless Steel With Hexagonal Column

10.1115/qnde2021-75766 ◽

2021 ◽

Author(s):

Shan Lin ◽

Yasushi Ikegami

Keyword(s):

Stainless Steel ◽

Fem Simulation ◽

Transversely Isotropic ◽

Primary Coolant ◽

Centrifugally Cast ◽

Anisotropic Property ◽

Array Probe ◽

Columnar Grains ◽

Promising Solution ◽

Cast Stainless Steel

Abstract Centrifugally cast stainless steel (CCSS) is widely used in PWR primary coolant systems. However, ultrasonic testing for such material is very challenging because its coarse grains and anisotropic property. The phased array ultrasonic technology (PAUT) is considered the most promising solution to the problem mentioned. To improve the accuracy of PAUT for CCSS with columnar grains, we used the voxel-based finite element method to perform simulation of wave propagation in CCSS, where waves were excited by a linear array. We modeled columnar grains in CCSS with hexagonal columns and introduced a side-drilled hole. It was easily to have different inclined columnar grains by rotating the crystal axes. All column crystals were considered cubic crystals while CCSS with columnar grains was macroscopically transversely isotropic. Wave propagations were computed for different focal laws and their results were compared. Waves exactly propagated toward and focused at the targeted SDH when focal laws were calculated according to the anisotropic property of CCSS, but deviated the target for focal laws based on isotropy.

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Identification and Location of Small Lead Particles Dispersed in As-Cast Stainless Steel / Bestimmung und Lokalisierung kleiner, in rostfreiem Stahl dispergierter Bleipartikeln

Practical Metallography ◽

10.1515/pm-1971-080505 ◽

1971 ◽

Vol 8 (5) ◽

pp. 300-308

Author(s):

Mario Sarracino ◽

Filippo S. Rossi

Keyword(s):

Stainless Steel ◽

Cast Stainless Steel

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Chlorine Resistance of Listeria monocytogenes Biofilms and Relationship to Subtype, Cell Density, and Planktonic Cell Chlorine Resistance

Journal of Food Protection ◽

10.4315/0362-028x-69.6.1292 ◽

2006 ◽

Vol 69 (6) ◽

pp. 1292-1296 ◽

Cited By ~ 38

Author(s):

JAMES P. FOLSOM ◽

JOSEPH F. FRANK

Keyword(s):

Stainless Steel ◽

Listeria Monocytogenes ◽

Cell Density ◽

Sodium Hypochlorite ◽

Resistance Mechanisms ◽

Planktonic Cell ◽

Planktonic Cells ◽

Planktonic Culture

Strains of Listeria monocytogenes vary in their ability to produce biofilms. This research determined if cell density, planktonic chlorine resistance, or subtype are associated with the resistance of L. monocytogenes biofilms to chlorine. Thirteen strains of L. monocytogenes were selected for this research based on biofilm accumulation on stainless steel and rep-PCR subtyping. These strains were challenged with chlorine to determine the resistance of individual strains of L. monocytogenes. Planktonic cells were exposed to 20 to 80 ppm sodium hypochlorite in 20 ppm increments for 5 min in triplicate per replication, and the experiment was replicated three times. The number of tubes with surviving L. monocytogenes was recorded for each isolate at each level of chlorine. Biofilms of each strain were grown on stainless steel coupons. The biofilms were exposed 60 ppm of sodium hypochlorite. When in planktonic culture, four strains were able to survive exposure to 40 ppm of chlorine, whereas four strains were able to survive 80 ppm of chlorine in at least one of three tubes. The remaining five strains survived exposure to 60 ppm of chlorine. Biofilms of 11 strains survived exposure to 60 ppm of chlorine. No association of biofilm chlorine resistance and planktonic chlorine resistance was observed; however, biofilm chorine resistance was similar for strains of the same subtype. Biofilm cell density was not associated with chlorine resistance. In addition, biofilms that survived chlorine treatment exhibited different biofilm morphologies. These data suggest that chlorine resistance mechanisms of planktonic cells and biofilms differ, with planktonic chlorine resistance being more affected by inducible traits, and biofilm chlorine resistance being more affected by traits not determined in this study.

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Biofilm formation by Vibrio parahaemolyticus on different surfaces and its resistance to sodium hypochlorite

Ciência Rural ◽

10.1590/0103-8478cr20180612 ◽

2018 ◽

Vol 48 (12) ◽

Cited By ~ 3

Author(s):

Janaina Viana da Rosa ◽

Natália Volpato da Conceição ◽

Rita de Cássia dos Santos da Conceição ◽

Cláudio Dias Timm

Keyword(s):

Stainless Steel ◽

Sodium Hypochlorite ◽

Biofilm Formation ◽

Vibrio Parahaemolyticus ◽

High Density Polyethylene ◽

High Density ◽

Bacterial Populations ◽

Farfantepenaeus Paulensis ◽

Materials Used ◽

Fish Industry

ABSTRACT: Vibrio parahaemolyticus is an important pathogen for both fish industry and consumers. It forms biofilm which makes it difficult to eliminate this microorganism using sanitizers. This study aimed to assess biofilm formation on different surfaces and effect of biofilm on resistance to sanitizers. Eight isolates of biofilm-forming V. parahaemolyticus were tested for the ability to form biofilms on a number of surfaces including high density polyethylene, stainless steel, glass, exoskeleton of Farfantepenaeus paulensis (Pink Shrimp), and operculum of Micropogonias furnieri (Whitemouth Croaker). Efficiency of sanitizer sodium hypochlorite against the bacteria was evaluated in the biofilms formed on the surface of the materials used; out the eight strains analyzed four formed biofilm on different surfaces. The present study shows that there are variations between surfaces in terms of biofilm formation, with more than one bacterial strain being able to form biofilm on the surface of the operculum of M. furnieri and on high density polyethylene as well. One isolate formed biofilm on glass, and one isolate formed biofilm on stainless steel. Sanitizers reduced biofilm formation on all surfaces. Based on our findings, we concluded that V. parahaemolyticus isolates have different ability to form biofilm on different surfaces. No isolates formed biofilm on shrimp shells. Results of this study also showed that sodium hypochlorite eat a concentration of 20 parts per million (20ppm) of Cl2, albeit not able to eliminate bacteria reported in biofilms, is still capable of reducing bacterial populations.

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Cast Stainless Steel and Nickel Base Alloys

Metallic Materials ◽

10.1201/9780203912423.ch17 ◽

2003 ◽

Keyword(s):

Stainless Steel ◽

Nickel Base ◽

Cast Stainless Steel

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Influence of disinfestation and osmotic conditioning on the germinating behavior of australian royal palm (Archontophoenix alexandrae)seeds

Revista Brasileira de Sementes ◽

10.1590/s0101-31222007000100021 ◽

2007 ◽

Vol 29 (1) ◽

pp. 155-159 ◽

Cited By ~ 1

Author(s):

Márcia Torres Teixeira ◽

Henrique Duarte Vieira ◽

Sílvio Lopes Teixeira ◽

Roberto Ferreira. da Silva

Keyword(s):

Sodium Hypochlorite ◽

Wood Species ◽

Pure Water ◽

Storage Conditions ◽

The Other ◽

Palm Tree ◽

Treatment Control ◽

Adverse Conditions ◽

Germination Speed ◽

Osmotic Potentials

The technique of Osmotic Conditioning, which consists of partial and controlled hydration of the seeds, has obtained success with various species of seeds, increasing the germinating span and tolerance to the adverse conditions of the environment, and has also reduced the time elapsed between sowing and the emergence of the plants. Associated to ideal storage conditions, the treatment has increased the performance of the seeds of tropical wood species. Aiming at studying the germinating environment and the effect of osmotic conditioning on the germination of seeds of the Australian Royal Palm tree, two experiments were performed. The first one evaluated the effect of disinfestation of the seeds of the Australian Royal Palm tree with NaClO. The treatments applied were: 0.5% sodium hypochlorite, exposure periods of 5, 15, 30, 45, 60, 90, 120 and 240 minutes, and the fungicide Captan, as control. The treatments with NaClO did not differ in relation to the final percentage of germination and to the germination speed index, and did not differ from the treatment control. The second test evaluated solutions with the following osmotic potentials: 0.0MPa (pure water), -0.4MPa, -0.6MPa and -0.8MPa, exposed for the periods of 10 and 20 days. The final percentage of germination did not differ among the treatments. The seeds hydrated in pure water for a period of 20 days showed a germination speed index significantly superior to the other treatments, and they did not show significant differences among themselves.

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