This paper analyzes micro-characteristics (single-particle wave functions, the dispersion law of elementary excitations) of sandwich structures. Such structures have exceptional properties and have become current issues in the light of relatively recent discoveries in crystalline structures such as boron nitride-graphene-boron nitride. In our case, structures with a simple cubic lattice are analyzed, but the results can be applied to the structures with monoclinic and triclinic lattices.
{"title":"Elementary particle microstates in sandwich nanostructures","authors":"J. Šetrajčić, S. Vučenović, S. Jaćimovski","doi":"10.5937/zasmat2302198s","DOIUrl":"https://doi.org/10.5937/zasmat2302198s","url":null,"abstract":"This paper analyzes micro-characteristics (single-particle wave functions, the dispersion law of elementary excitations) of sandwich structures. Such structures have exceptional properties and have become current issues in the light of relatively recent discoveries in crystalline structures such as boron nitride-graphene-boron nitride. In our case, structures with a simple cubic lattice are analyzed, but the results can be applied to the structures with monoclinic and triclinic lattices.","PeriodicalId":23842,"journal":{"name":"Zastita materijala","volume":"61 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87762552","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
L. Nyrkova, Anatolii Rybakov, L. Goncharenko, S. Osadchuk, Yulia Kharchenko
A complex of research has been conducted to establish the causes of the accident of the main gas pipeline made of 1420x15.7 mm X70 steel after 20 years of operation. It is found that pipe destruction was initiated by the longitudinal crack with a length of 470 mm and a maximum depth of 6.8 mm, oriented in the direction of the pipe and perpendicular to the outer surface of the pipe identified as stress-corrosion cracking. The crack initiation is due to the disboundment of the tape protection coating, the high corrosion activity of the soil, and the complex stress-strain state caused by deviations from the design objectives during construction. The chemical composition the base metal of all investigated pipes corresponds to the requirements of the technical conditions for steel pipes in category X70; pipes welding are performed with the typical materials used in pipe welding plants. Despite the differences, the structural and mechanical characteristics (yield strength, ultimate strength, and impact strength) of the steel and weld metal of the studied pipes are identical. The relative elongation (d5) of the operated pipes is below the normalized values, but, it is necessary to take into account the possibility of deviations in these characteristics of steel in the initial state. Significant reserves of toughness indirectly indicate low damage of metal and, accordingly, satisfactory resistance to destruction of the metal of the studied pipes.
为查明运行20年的1420x15.7 mm X70钢主燃气管道发生事故的原因，进行了综合研究。结果表明，管道破坏是由纵向裂缝引起的，裂缝长度为470 mm，最大深度为6.8 mm，裂缝方向与管道方向一致，垂直于管道外表面，为应力腐蚀裂纹。裂缝的起裂是由于胶带保护涂层的脱落、土壤的高腐蚀活性以及施工过程中偏离设计目标导致的复杂应力-应变状态。所有被调查钢管的母材化学成分符合X70类钢管技术条件的要求;管道焊接是用管道焊接厂使用的典型材料进行的。尽管存在差异，但所研究的管道的钢和焊缝金属的结构和力学特性(屈服强度、极限强度和冲击强度)是相同的。运行管道的相对伸长率(d5)低于标准化值，但有必要考虑钢在初始状态下这些特性偏差的可能性。较大的韧性储备间接表明金属损伤低，因此所研究的管道具有令人满意的抗破坏能力。
{"title":"Analysis of the causes of fracture of the main gas pipeline","authors":"L. Nyrkova, Anatolii Rybakov, L. Goncharenko, S. Osadchuk, Yulia Kharchenko","doi":"10.5937/zasmat2302177n","DOIUrl":"https://doi.org/10.5937/zasmat2302177n","url":null,"abstract":"A complex of research has been conducted to establish the causes of the accident of the main gas pipeline made of 1420x15.7 mm X70 steel after 20 years of operation. It is found that pipe destruction was initiated by the longitudinal crack with a length of 470 mm and a maximum depth of 6.8 mm, oriented in the direction of the pipe and perpendicular to the outer surface of the pipe identified as stress-corrosion cracking. The crack initiation is due to the disboundment of the tape protection coating, the high corrosion activity of the soil, and the complex stress-strain state caused by deviations from the design objectives during construction. The chemical composition the base metal of all investigated pipes corresponds to the requirements of the technical conditions for steel pipes in category X70; pipes welding are performed with the typical materials used in pipe welding plants. Despite the differences, the structural and mechanical characteristics (yield strength, ultimate strength, and impact strength) of the steel and weld metal of the studied pipes are identical. The relative elongation (d5) of the operated pipes is below the normalized values, but, it is necessary to take into account the possibility of deviations in these characteristics of steel in the initial state. Significant reserves of toughness indirectly indicate low damage of metal and, accordingly, satisfactory resistance to destruction of the metal of the studied pipes.","PeriodicalId":23842,"journal":{"name":"Zastita materijala","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79708267","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Triple-negative breast cancer (TNBC) accounts for 15-20% of all invasive breast cancers and has a poor prognosis. ZnO NPs are promising anti-cancer agents. Moreover, folate Alpha receptor (FRa) is a potential biomarker and therapeutic target because it is significantly expressed in TNBC. Therefore, ZnO and folic acid-conjugated ZnO (F-ZnO) NPs were synthesized by the solgel method. NPs were characterized by DLS, zeta potential, TEM, FTIR, and ICP-MS. FA-ZnO NPs had a mean diameter of 20 ± 2 nm and a surface charge of -15 mV, while ZnO NPs had a mean diameter of 40 ± 5 nm and a surface charge of -5 mV. The MTT assay and trypan blue test, respectively, were used to determine the cytotoxicity and viability percentage of ZnO and F-ZnO NPs at different concentrations of 2, 4, 8, 16, 32, 64 and 128 µg/mL for 12, 24, 48 and 72 hours (h) on the human TNBC cell line MDA-MB-231. The results indicated that both ZnO and F-ZnO NPs significantly reduced the viability of the cancer cells in a dose-dependent and time-dependent manner (p<0.05). The IC50 values for FA-ZnO NPs were approximately 3, 3.74, 4.38 and 5.5 times higher than those for ZnO NPs at 12-, 24-, 48and 72-hour time points, respectively. The results suggest that F-ZnO NPs have the potential to be a good option for TNBC treatment and warrant further investigations.
{"title":"Investigating the therapeutic effect of folic acid conjugated ZnO nanoparticles on human triple negative breast cancer cell line","authors":"Shiva Sabzandam, Masoumeh Zahmatkeshan, Moein Adel, Mehrad Mehrdadian, Farzaneh Saliminia, F. Esmaeili","doi":"10.5937/zasmat2302213s","DOIUrl":"https://doi.org/10.5937/zasmat2302213s","url":null,"abstract":"Triple-negative breast cancer (TNBC) accounts for 15-20% of all invasive breast cancers and has a poor prognosis. ZnO NPs are promising anti-cancer agents. Moreover, folate Alpha receptor (FRa) is a potential biomarker and therapeutic target because it is significantly expressed in TNBC. Therefore, ZnO and folic acid-conjugated ZnO (F-ZnO) NPs were synthesized by the solgel method. NPs were characterized by DLS, zeta potential, TEM, FTIR, and ICP-MS. FA-ZnO NPs had a mean diameter of 20 ± 2 nm and a surface charge of -15 mV, while ZnO NPs had a mean diameter of 40 ± 5 nm and a surface charge of -5 mV. The MTT assay and trypan blue test, respectively, were used to determine the cytotoxicity and viability percentage of ZnO and F-ZnO NPs at different concentrations of 2, 4, 8, 16, 32, 64 and 128 µg/mL for 12, 24, 48 and 72 hours (h) on the human TNBC cell line MDA-MB-231. The results indicated that both ZnO and F-ZnO NPs significantly reduced the viability of the cancer cells in a dose-dependent and time-dependent manner (p<0.05). The IC50 values for FA-ZnO NPs were approximately 3, 3.74, 4.38 and 5.5 times higher than those for ZnO NPs at 12-, 24-, 48and 72-hour time points, respectively. The results suggest that F-ZnO NPs have the potential to be a good option for TNBC treatment and warrant further investigations.","PeriodicalId":23842,"journal":{"name":"Zastita materijala","volume":"6 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80417976","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
E. Imo, C. Ihejirika, Adaugo Ndukaku, Peter Misoni
The microbiologically influenced corrosion of mild steel and aluminum in sea water (SW) caused by a sulfate reducing bacterium (SRB), Desulfotomaculum sp was investigated. The corrosion rates were evaluated at intervals of ten days for a period of sixty days using gravimetric and electrochemical methods. Results showed that corrosion rate decreased with exposure time after initial increase. The plot of the electrode potential (EP) with the exposure time shows a decrease as resistance increased due to the corrosion product formed on the surface of the metals. Aluminum recorded a maximal EP reduction (-0.85 mV) after 60 days of incubation, with an onset potential of -0.53 mV after 10 days. The more negative the EP, the greater the tendency to form ions and hence to corrode. The average corrosion rate of mild steel and aluminum coupons in the presence of SRB was 4-fold higher compared to coupons on media without Desulfotomaculum sp.
{"title":"Effects of Desulfotomaculum sp on corrosion behaviour of mild steel and aluminium in sea water","authors":"E. Imo, C. Ihejirika, Adaugo Ndukaku, Peter Misoni","doi":"10.5937/zasmat2302190i","DOIUrl":"https://doi.org/10.5937/zasmat2302190i","url":null,"abstract":"The microbiologically influenced corrosion of mild steel and aluminum in sea water (SW) caused by a sulfate reducing bacterium (SRB), Desulfotomaculum sp was investigated. The corrosion rates were evaluated at intervals of ten days for a period of sixty days using gravimetric and electrochemical methods. Results showed that corrosion rate decreased with exposure time after initial increase. The plot of the electrode potential (EP) with the exposure time shows a decrease as resistance increased due to the corrosion product formed on the surface of the metals. Aluminum recorded a maximal EP reduction (-0.85 mV) after 60 days of incubation, with an onset potential of -0.53 mV after 10 days. The more negative the EP, the greater the tendency to form ions and hence to corrode. The average corrosion rate of mild steel and aluminum coupons in the presence of SRB was 4-fold higher compared to coupons on media without Desulfotomaculum sp.","PeriodicalId":23842,"journal":{"name":"Zastita materijala","volume":"26 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75313495","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Ndukwe, Dan Etim, Anaele Uchenna, Ozoh Chibuike, Kooffreh Okon, Paulinus Agu
This study examined earlier research on using papaya and neem extracts as inhibitors to minimize the corrosion of mild steel in a variety of corrosive situations. The potential inhibitory characteristics of plant extracts to potentially replace the hitherto used, well-known inhibitors that are harmful to the people handling them as well as the environment, inspired several scholars to conduct corrosion inhibition tests on metals using plant extracts. The findings of earlier research demonstrated that the maximal inhibitory efficiency provided by neem leaf extract to prevent the degradation of carbon steel in a hydrochloric acid (1 M) medium was 97%, while 86% was observed for the protection in H2SO4 (1 M) solution. The extract from Carica papaya leaves was shown to have up to 83% maximum inhibitory efficacy for preventing mild steel corrosion in HCl (1 M). It has been revealed that when extract concentration increased, the rate of steel corrosion reduced. Additionally, papaya leaves' corrosion-inhibiting mechanism was said to occur mostly in the cathodic area. Both plant-leaf extracts (Papaya and Neem) have been reported to have adsorption qualities that, for the most part, agreed with the Langmuir adsorption isotherm model.
{"title":"The inhibition of mild steel corrosion by papaya and neem extracts","authors":"A. Ndukwe, Dan Etim, Anaele Uchenna, Ozoh Chibuike, Kooffreh Okon, Paulinus Agu","doi":"10.5937/zasmat2303274n","DOIUrl":"https://doi.org/10.5937/zasmat2303274n","url":null,"abstract":"This study examined earlier research on using papaya and neem extracts as inhibitors to minimize the corrosion of mild steel in a variety of corrosive situations. The potential inhibitory characteristics of plant extracts to potentially replace the hitherto used, well-known inhibitors that are harmful to the people handling them as well as the environment, inspired several scholars to conduct corrosion inhibition tests on metals using plant extracts. The findings of earlier research demonstrated that the maximal inhibitory efficiency provided by neem leaf extract to prevent the degradation of carbon steel in a hydrochloric acid (1 M) medium was 97%, while 86% was observed for the protection in H2SO4 (1 M) solution. The extract from Carica papaya leaves was shown to have up to 83% maximum inhibitory efficacy for preventing mild steel corrosion in HCl (1 M). It has been revealed that when extract concentration increased, the rate of steel corrosion reduced. Additionally, papaya leaves' corrosion-inhibiting mechanism was said to occur mostly in the cathodic area. Both plant-leaf extracts (Papaya and Neem) have been reported to have adsorption qualities that, for the most part, agreed with the Langmuir adsorption isotherm model.","PeriodicalId":23842,"journal":{"name":"Zastita materijala","volume":"84 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85995766","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The inhibitive effect of applied magnetic fields on the corrosion of mild steel in 1.0M HCl and 0.5M H2SO4 acid solutions has been investigated at room temperature by using the gravimetric technique. A locally made electromagnet with variable outputs and powered by a direct current source voltage provided the magnetic fields. In a typical experiment, the applied magnetic field was applied perpendicularly onto the surface of a mild steel coupon immersed completely in a chosen acid solution for an exposure time of two hours. It was observed that the corrosion rates of mild steel determined for each case of 1.0M HCl and 0.5M H2SO4 test solutions decrease as the applied magnetic field increases. This indicates that the presence of the applied magnetic field inhibits the corrosion of the mild steel in the test solutions. Results also show that the protection efficiency of the magnetic field increases as the applied magnetic field increases. More specifically, as the magnetic field was increased from 118.2 - 764.3mG [or 0.01182 - 0.07643 mT], the protection efficiency increased from 36.34 - 62.67% for mild steel in 1.0M HCl acid solution, while for mild steel in 0.5M H2SO4 acid solution, the protection efficiency increased from 12.68 - 46.88%. It was demonstrated that the observed inhibitive effect of the magnetic fields can be attributed partly to the phenomenon of transverse magnetoresistance and partly to the effect of the magnetic fields on the mass transport properties of the constituent ions in the electrochemical system
{"title":"The inhibitive effect of magnetic fields on mild steel corrosion in acidic media","authors":"Obi Tamadu, Mejeha Maurice, Okeoma Bierechi","doi":"10.5937/zasmat2301030o","DOIUrl":"https://doi.org/10.5937/zasmat2301030o","url":null,"abstract":"The inhibitive effect of applied magnetic fields on the corrosion of mild steel in 1.0M HCl and 0.5M H2SO4 acid solutions has been investigated at room temperature by using the gravimetric technique. A locally made electromagnet with variable outputs and powered by a direct current source voltage provided the magnetic fields. In a typical experiment, the applied magnetic field was applied perpendicularly onto the surface of a mild steel coupon immersed completely in a chosen acid solution for an exposure time of two hours. It was observed that the corrosion rates of mild steel determined for each case of 1.0M HCl and 0.5M H2SO4 test solutions decrease as the applied magnetic field increases. This indicates that the presence of the applied magnetic field inhibits the corrosion of the mild steel in the test solutions. Results also show that the protection efficiency of the magnetic field increases as the applied magnetic field increases. More specifically, as the magnetic field was increased from 118.2 - 764.3mG [or 0.01182 - 0.07643 mT], the protection efficiency increased from 36.34 - 62.67% for mild steel in 1.0M HCl acid solution, while for mild steel in 0.5M H2SO4 acid solution, the protection efficiency increased from 12.68 - 46.88%. It was demonstrated that the observed inhibitive effect of the magnetic fields can be attributed partly to the phenomenon of transverse magnetoresistance and partly to the effect of the magnetic fields on the mass transport properties of the constituent ions in the electrochemical system","PeriodicalId":23842,"journal":{"name":"Zastita materijala","volume":"5 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87258052","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
T. Gowrani, Nilavan Anitha, M. Dhanalakshmi, Subramaniam Aishwarya, Mary Subashini, Jenifer Flori, Shree Nithiya, Gurmeet Singh, A. Al-Hashem, S. Rajendran
Corrosion resistance of thermo active alloy and Gold 18K alloy immersed in artificial sweat in the absence and presence of 100 ppm of NaCl has been investigated by polarization study and AC impedance spectra. It is observed that corrosion resistance of thermo active alloy and also Gold 18K alloy immersed in artificial sweat in the presence of 100 ppm of NaCl increases. Hence it is concluded that people wearing ornaments made of these two alloys need not worry about the excess of sodium chloride in their sweat. When thermo active alloy is immersed in artificial sweat in the presence of 100 ppm of NaCl, linear polarization resistance value increases from 1760283 Ohm cm2 to 9506106 Ohm cm2 ; corrosion current decreases from 1.845x10-8 to 4.008x10-9 A/cm2 ; charge transfer resistance value increases from 4884 Ohmcm2 to 12210 Ohm cm2 ; impedance value increases from 4.367 to 4.8; double layer capacitance decreases from 1.0442 x10 -9 to 4.1769x10-10 F/cm2 , and phase angle increases from 48.1 to 66.34°. When Gold 18K alloy is immersed in artificial sweat in the presence of 100 ppm of NaCl, linear polarization resistance value increases from 1079199 Ohmcm2 to 2385141 Ohm cm2 ; corrosion current decreases from 4.036x10-8 to 0.1966 x 10 -8A/cm2 ; charge transfer resistance increases from 4291 Ohm cm2 to 48880 Ohm cm2 ; impedance value increases from 4.652 to 5.114; double layer capacitance decreases from 1.189 x10-9 to 1.0434 x10-10 F/cm2 , and phase angle increases from 61 to 88.
{"title":"Electrochemical studies on the corrosion resistance of Gold 18K and thermo active alloy in artificial sweat in presence of sodium chloride","authors":"T. Gowrani, Nilavan Anitha, M. Dhanalakshmi, Subramaniam Aishwarya, Mary Subashini, Jenifer Flori, Shree Nithiya, Gurmeet Singh, A. Al-Hashem, S. Rajendran","doi":"10.5937/zasmat2301038g","DOIUrl":"https://doi.org/10.5937/zasmat2301038g","url":null,"abstract":"Corrosion resistance of thermo active alloy and Gold 18K alloy immersed in artificial sweat in the absence and presence of 100 ppm of NaCl has been investigated by polarization study and AC impedance spectra. It is observed that corrosion resistance of thermo active alloy and also Gold 18K alloy immersed in artificial sweat in the presence of 100 ppm of NaCl increases. Hence it is concluded that people wearing ornaments made of these two alloys need not worry about the excess of sodium chloride in their sweat. When thermo active alloy is immersed in artificial sweat in the presence of 100 ppm of NaCl, linear polarization resistance value increases from 1760283 Ohm cm2 to 9506106 Ohm cm2 ; corrosion current decreases from 1.845x10-8 to 4.008x10-9 A/cm2 ; charge transfer resistance value increases from 4884 Ohmcm2 to 12210 Ohm cm2 ; impedance value increases from 4.367 to 4.8; double layer capacitance decreases from 1.0442 x10 -9 to 4.1769x10-10 F/cm2 , and phase angle increases from 48.1 to 66.34°. When Gold 18K alloy is immersed in artificial sweat in the presence of 100 ppm of NaCl, linear polarization resistance value increases from 1079199 Ohmcm2 to 2385141 Ohm cm2 ; corrosion current decreases from 4.036x10-8 to 0.1966 x 10 -8A/cm2 ; charge transfer resistance increases from 4291 Ohm cm2 to 48880 Ohm cm2 ; impedance value increases from 4.652 to 5.114; double layer capacitance decreases from 1.189 x10-9 to 1.0434 x10-10 F/cm2 , and phase angle increases from 61 to 88.","PeriodicalId":23842,"journal":{"name":"Zastita materijala","volume":"17 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87979312","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Amala Suvakeen, K. Kavipriya, Senthil Vadivelan, Anu Ratthika, T. Vidhya, Sindhuja Jerleen, Nilavan Anitha, R. Srinivasan, S. Rajendran, T. Gowrani
Copper barrel brandy can be taken orally with dilution of bisleri water or soda water and without dilution. People clipped with orthodontic wires may take copper barrel brandy orally, with dilution of without dilution. How far the orthodontic wires will be affected by these items? To find an answer the present research work is undertaken. Corrosion resistance of orthodontic wires made of Ni-Ti alloy and Ni-Cr alloy in artificial saliva in the absence and presence of copper barrel, water and soda water has been evaluated by AC impedance spectra. It is generally observed that Ni-Ti alloy is more corrosion resistant than Ni-Cr alloy in artificial saliva in the presence of copper barrel, water and soda water. When orthodontic wire made of Ni-Ti is immersed in artificial saliva, the charge transfer resistance (Rt) value is 31945Ohmcm2 . When it is immersed in copper barrel + artificial saliva (AS) system, Rtvalue increase to 80000Ohmcm2 . When it is immersed in soda water + artificial saliva (AS) system, Rtvalue increase to 76450Ohmcm2 . When it is immersed in water + artificial saliva (AS) system, Rtvalue increase to 82620Ohmcm2 . On the other hand, when orthodontic wire made of Ni-Cr is immersed in artificial saliva, the charge transfer resistance (Rt) value is 80930Ohmcm2 . When it is immersed in copper barrel + artificial saliva (AS) system, Rtvalue decrease to 11104Ohmcm2 . When it is immersed in soda water + artificial saliva (AS) system, Rtvalue decrease to 10437Ohmcm2 . It implies that the people who have been clipped with orthodontic wire made of Ni-Ti alloy can take copper barrel in any form, namely, with dilution or without dilution. The people who have been clipped with orthodontic wire made of Ni-Cr alloy should avoid taking copper barrel in any form, namely, with dilution or without dilution.
{"title":"Influence of dilution and addition of soda water on the corrosion resistance of orthodontic wires immersed in artificial saliva in presence of Copper Barrel, a hard drink","authors":"Amala Suvakeen, K. Kavipriya, Senthil Vadivelan, Anu Ratthika, T. Vidhya, Sindhuja Jerleen, Nilavan Anitha, R. Srinivasan, S. Rajendran, T. Gowrani","doi":"10.5937/zasmat2302119a","DOIUrl":"https://doi.org/10.5937/zasmat2302119a","url":null,"abstract":"Copper barrel brandy can be taken orally with dilution of bisleri water or soda water and without dilution. People clipped with orthodontic wires may take copper barrel brandy orally, with dilution of without dilution. How far the orthodontic wires will be affected by these items? To find an answer the present research work is undertaken. Corrosion resistance of orthodontic wires made of Ni-Ti alloy and Ni-Cr alloy in artificial saliva in the absence and presence of copper barrel, water and soda water has been evaluated by AC impedance spectra. It is generally observed that Ni-Ti alloy is more corrosion resistant than Ni-Cr alloy in artificial saliva in the presence of copper barrel, water and soda water. When orthodontic wire made of Ni-Ti is immersed in artificial saliva, the charge transfer resistance (Rt) value is 31945Ohmcm2 . When it is immersed in copper barrel + artificial saliva (AS) system, Rtvalue increase to 80000Ohmcm2 . When it is immersed in soda water + artificial saliva (AS) system, Rtvalue increase to 76450Ohmcm2 . When it is immersed in water + artificial saliva (AS) system, Rtvalue increase to 82620Ohmcm2 . On the other hand, when orthodontic wire made of Ni-Cr is immersed in artificial saliva, the charge transfer resistance (Rt) value is 80930Ohmcm2 . When it is immersed in copper barrel + artificial saliva (AS) system, Rtvalue decrease to 11104Ohmcm2 . When it is immersed in soda water + artificial saliva (AS) system, Rtvalue decrease to 10437Ohmcm2 . It implies that the people who have been clipped with orthodontic wire made of Ni-Ti alloy can take copper barrel in any form, namely, with dilution or without dilution. The people who have been clipped with orthodontic wire made of Ni-Cr alloy should avoid taking copper barrel in any form, namely, with dilution or without dilution.","PeriodicalId":23842,"journal":{"name":"Zastita materijala","volume":"11 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79211144","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
2-dimensional mathematical model of axisymmetric transient industrial quenched low carbon steel bar, to examine the influence of process history on metallurgical and material characteristics, a water-cooled model based on the finite element technique was adopted. A 2-dimensional axisymmetric mathematical model was utilized to predict temperature history and, as a result, the hardness of the quenched steel bar at any node (point). The LHP (lowest hardness point) is evaluated. In this paper, specimen points hardness was evaluated by the transformation of determined characteristic cooling time for phase conversion t8/5 to hardness. The model can be used as a guideline to design cooling approach to attain the desired microstructure and mechanical properties, for example, hardness. The mathematical model was verified and validated by comparing its hardness results to the results of commercial finite element software. The comparison demonstrates that the proposed model is reliable.
{"title":"A novel 2-D mathematical modeling to determine LHP to protect the industrial transient heat treatment quenched low carbon steels bar","authors":"A. Elmaryami, Amal Mohamed","doi":"10.5937/zasmat2303327e","DOIUrl":"https://doi.org/10.5937/zasmat2303327e","url":null,"abstract":"2-dimensional mathematical model of axisymmetric transient industrial quenched low carbon steel bar, to examine the influence of process history on metallurgical and material characteristics, a water-cooled model based on the finite element technique was adopted. A 2-dimensional axisymmetric mathematical model was utilized to predict temperature history and, as a result, the hardness of the quenched steel bar at any node (point). The LHP (lowest hardness point) is evaluated. In this paper, specimen points hardness was evaluated by the transformation of determined characteristic cooling time for phase conversion t8/5 to hardness. The model can be used as a guideline to design cooling approach to attain the desired microstructure and mechanical properties, for example, hardness. The mathematical model was verified and validated by comparing its hardness results to the results of commercial finite element software. The comparison demonstrates that the proposed model is reliable.","PeriodicalId":23842,"journal":{"name":"Zastita materijala","volume":"15 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75236370","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ion-plasma coatings are widely used to increase the wear resistance of hard alloy metalworking tools. However, plasma coatings are practically not combined with other technological operations and do not improve the physical and mechanical properties of tool working elements. Hardening tools made of hard alloys is one of the promising directions that is created by layered structures on the surface. It provides a gradient distribution of physical and chemical properties between the wear-resistant coating and the base material.
{"title":"Ion nitriding and surface alloying of H13A hard alloy cutting tools","authors":"Toshbotirovich Doniyor","doi":"10.5937/zasmat2302161t","DOIUrl":"https://doi.org/10.5937/zasmat2302161t","url":null,"abstract":"Ion-plasma coatings are widely used to increase the wear resistance of hard alloy metalworking tools. However, plasma coatings are practically not combined with other technological operations and do not improve the physical and mechanical properties of tool working elements. Hardening tools made of hard alloys is one of the promising directions that is created by layered structures on the surface. It provides a gradient distribution of physical and chemical properties between the wear-resistant coating and the base material.","PeriodicalId":23842,"journal":{"name":"Zastita materijala","volume":"20 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73663712","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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