Effect of Zn/Al Cation Ratio on Corrosion Inhibition Capabilities of Hydrotalcites Containing Benzoate Against Carbon Steel

Thuy Duong Nguyen,To Thi Xuan Hang,Thu Thuy Pham,Anh Son Nguyen,Thu Thuy Thai,Gia Vu Pham,Ngoc Bach Ta 한국부식방식학회 2022 Corrosion Science and Technology Vol.21 No.6

Corrosion inhibitors based on Zn-Al hydrotalcites containing benzoate (ZnAlHB) with different molar ratios of Zn/Al were prepared with a co-precipitation process. Compositions and structures of the resulting hydrotalcites were studied with suitable spectroscopic methods such as inductively coupled plasma mass spectrometry (ICP-MS), ultraviolet-visible spectrophotometry (UV-Vis), scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and surface zeta potential measurements, respectively. Results of physico-chemical studies showed that crystallite sizes, compositions of products, and surface electrical properties were significantly changed when the molar ratio of Zn/Al was increased. The release of benzoate from hydrotalcites also differed slightly among samples. Anticorrosion abilities of hydrotalcites intercalated with benzoate at a concentration of 3 g/L on carbon steel were analyzed using electrochemical impedance spectroscopy (EIS), polarization curve, energy-dispersive X-ray spectroscopy (EDX), and SEM. Corrosion inhibition abilities of benzoate modified hydrotalcites in 0.1 M NaCl showed an upward trend with increasing Zn/Al ratio. The reason for the dependence of corrosion resistance on the Zn/Al ratio was discussed, including changes in the microstructure of hydrotalcites such as crystal size, density, uniformity, and formation of ZnO.

Inhibitory Effect of Benzoate-intercalated Hydrotalcite with Ce³⁺-loaded clay on Carbon Steel

( Thuy Duong Nguyen ),( Thu Thuy Pham ),( Anh Son Nguyen ),( Ke Oanh Vu ),( Gia Vu Pham ),( To Thi Xuan Hang ) 한국부식방식학회 2023 Corrosion Science and Technology Vol.22 No.1

This work studied the inhibitory effect of the combination of benzoate-intercalated hydrotalcite (HT-BZ) and Ce³⁺-loaded clay (Clay-Ce) on carbon steel (CS). HT-BZ was prepared by the co-precipitation method and Clay-Ce was fabricated by a cation exchange reaction. HT-BZ and Clay-Ce were assessed by scanning electron microscopy (SEM) and X-ray diffraction (XRD) coupled with zeta potential measurement. Electrochemical measurements coupled with scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM/EDX) were used for studying the inhibitory action of the mixture of HT-BZ and Clay-Ce on steel electrodes immersed in 0.1 M NaCl. For comparison, the inhibitory effect of HT-BZ or Clay-Ce alone was also evaluated. The results showed that HT-BZ combined with Clay-Ce provided synergistic inhibition of the CS substrate. The mixture of 0.5 g/L HT-BZ + 0.5 g/L Clay-Ce provided 93.5% inhibition efficiency. The protective mechanism of the HT-BZ + Clay-Ce mixture consisted of the reaction of released BZ and Ce³⁺ and the deposition of HT-BZ and Clay-Ce structures on the CS substrate.

A Comparative Study on the Adipogenic and Myogenic Capacity of Muscle Satellite Cells, and Meat Quality Characteristics between Hanwoo and Vietnamese Yellow Steers

Nguyen Thu Uyen,Dao Van Cuong,Pham Dieu Thuy,Luu Hong Son,Nguyen Thi Ngan,Nguyen Hung Quang,Nguyen Duc Tuan,In-ho Hwang 한국축산식품학회 2023 한국축산식품학회지 Vol.43 No.4

Myogenesis and adipogenesis are the important processes determining the muscle growth and fat accumulation livestock, which ultimately affecting their meat quality. Hanwoo is a popular breed and its meat has been exported to other countries. The objective of this study was to compare the myogenesis and adipogenesis properties in satellite cells, and meat quality between Hanwoo and Vietnamese yellow cattle (VYC). Same 28-months old Hanwoo (body weight: 728±45 kg) and VYC (body weight: 285±36 kg) steers (n=10 per breed) were used. Immediately after slaughter, tissue samples were collected from longissimus lumborum (LL) muscles for satellite cells isolation and assays. After 24 h post-mortem, LL muscles from left carcass sides were collected for meat quality analysis. Under the same in vitro culture condition, the proliferation rate was higher in Hanwoo compared to VYC (p<0.05). Fusion index was almost 3 times greater in Hanwoo (42.17%), compared with VYC (14.93%; p<0.05). The expressions of myogenesis (myogenic factor 5, myogenic differentiation 1, myogenin, and myogenic factor 6)- and adipogenesis (peroxisome proliferator-activated receptor gamma)-regulating genes, and triglyceride content were higher in Hanwoo, compared with VYC (p<0.05). Hanwoo beef had a higher intramuscular fat and total monounsaturated fatty acids contents than VYC beef (p<0.05). Whilst, VYC meat had a higher CIE a* and total polyunsaturated fatty acids content (p<0.05). Overall, there was a significant difference in the in vitro culture characteristics and genes expression of satellite cells, and meat quality between the Hanwoo and VYC.

Foreign Direct Investment -Small and Medium Enterprises Linkages and Global Value Chain Participation: Evidence from Vietnam

NGUYEN, Thi Minh Thu,NGUYEN, Thi Tuong Anh,NGUYEN, Thi Thuy Vinh,PHAM, Huong Giang Korea Distribution Science Association 2021 The Journal of Asian Finance, Economics and Busine Vol.8 No.3

Using a multinomial logit model with the panel-data set of Vietnam manufacturing firms, this paper investigates the impacts of foreign direct investment (FDI) - small and medium enterprises (SMEs) linkages and other factors on SMEs' participation in the global value chain (GVC). We consider GVC firms are those engaging in any of the three modes including (i) using domestic inputs to export (D2E), (ii) using imported inputs to produce for the domestic market (I2P), (iii) using imported inputs to export (I2E). We discover that FDI-SME linkages statistically encourage Vietnamese SMEs to integrate into the GVC via I2P and I2E, while no statistical association between FDI-SME linkage and D2E participation is found. GVCs participation likelihood is also positively correlated with the introduction of new product introduction. The establishment of firms' production facilities in industrial zones and foreign ownership are both reported to be significantly decisive factors to SMEs' decisions on GVC participation. Besides, there is a strong association between firms' attributes, i.e. employment, capital intensity as well as financial access, and their participation in the GVC. Local governance quality (proxied by the Provincial Competitiveness Index) and the share of skilled labor at the province-level can facilitate firms' integration into GVCs, while greater market concentration may be a hurdle to such potential.

Factors Affecting Infrastructure Connectivity: An Indian and Vietnamese Perspective

Thuy T.Dang,Nguyen Le Thy Thuong,Pham Thuy Nguyen 한국외국어대학교 인도연구소 2021 남아시아연구 Vol.27 No.3

Infrastructure connectivity plays an important role in Vietnam and India’s trade promotion, and international economic development and cooperation. Vietnam and India have become comprehensive strategic partners since 2016. In its “Act East” Policy, India considered Vietnam as a crucial destination for infrastructure development, trading and investment projects as well as a bridge to connect India with the Southeast Asia region. The article presents direct factors affecting infrastructure connectivity between India and Vietnam, in different aspects including geography and nature; politics and diplomacy; finance and economics; institutional policies and regulations; society and people; and infrastructure. From analyzing these factors, it can be seen that the harmonious diplomatic relations, stable internal politics and the increase in cooperation between Vietnam and India in various fields contribute to ensuring Vietnam - India infrastructure connectivity cooperation. A young, highly skilled workforce and a strong culture of integration also create favorable conditions for infrastructure connectivity between the two countries. However, the remote geographical distance, the limited economic resources, the relative disparity in the level of development of hard and soft infrastructure as well as the limited institutional capacity of each country create certain barriers. Due to the delay in decision-making and planning between the two countries, no direct projects between the two countries have been implemented so far. Currently, it is only possible to place the Vietnam - India infrastructure connectivity projects in the ASEAN - India infrastructure connectivity network, but most of these projects also stop at drafting and planning phase. Therefore, the infrastructure connectivity between Vietnam and India needs to overcome many barriers to achieve certain results.

The Influence of Hydrotalcite Intercalated with Benzoate on UV Stability of Acrylic Coating

Thuy Duong Nguyen,Anh Son Nguyen,Thu Thuy Thai,Gia Vu Pham,Thi Xuan Hang To,Marie-Georges Olivier 한국부식방식학회 2020 Corrosion Science and Technology Vol.19 No.1

It is important to realize that benzoate was intercalated into hydrotalcite (HTC-Bz) by the co-precipitationmethod. In this case, acrylic coating with 0.5 wt% HTC-Bz was deposited on carbon steel using the spincoating method. Next, the HTC-Bz structure was characterized by Field emission scanning electron microscopy(FESEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FT-IR). In fact, an ultravioletvision spectroscopy (UV-Vis) was used to determine the benzoate content in HTC-Bz, and the UV absorptionability of HTC-Bz. Using electrochemical techniques, water contact angle measurement, and thermal-gravimetricanalysis, we compared the protective properties before and after QUV test, hydrophobicity and the thermalstability of acrylic coating containing HTC-Bz. The obtained results showed that HTC-Bz with a plate-likestructure was successfully synthesized; benzoate was intercalated into the interlayer of hydrotalcite witha concentration of 28 wt%. Additionally, it was noted that HTC-Bz has an UV absorption peak at 225nm. In conclusion, the addition of HTC-Bz enhanced the UV stability, hydrophobicity and the thermal stabilityof acrylic coating.

Synthesis and Characterization of Hydrotalcite/Graphene Oxide Containing Benzoate for Corrosion Protection of Carbon Steel

( Thuy Duong Nguyen ),( Boi An Tran ),( Ke Oanh Vu ),( Anh Son Nguyen ),( Anh Truc Trinh ),( Gia Vu Pham ),( Thi Xuan Hang To ),( Thanh Thao Phan ) 한국부식방식학회(구 한국부식학회) 2020 Corrosion Science and Technology Vol.19 No.2

This work examined the corrosion protection performance of benzoate loaded hydrotalcite/graphene oxide (HT/GO-BZ) for carbon steel. HT/GO-BZ was fabricated by the co-precipitation method and characterized by infrared spectroscopy, X-ray diffraction, and scanning electronic microscopy. The corrosion inhibition action of HT/GO-BZ on carbon steel in 0.1 M NaCl solution was evaluated by electrochemical measurements. The benzoate content in HT/GO-BZ was determined by UV-Vis spectroscopy. Subsequently, the effect of HT/GO-BZ on the corrosion resistance of the water-based epoxy coating was investigated by the salt spray test. The obtained results demonstrated the intercalation of benzoate and GO in the hydrotalcite structure. The benzoate content in HT/GO-BZ was about 16%. The polarization curves of the carbon steel electrode revealed anodic corrosion inhibition activity of HT/GO-BZ and the inhibition efficiency was about 95.2% at a concentration of 3g/L. The GO present in HT/GO-BZ enhanced the inhibition effect of HT-BZ. The presence of HT/GO-BZ improved the corrosion resistance of the waterborne epoxy coating.

Preparing cuprous oxide nanomaterials by electrochemical method for non-enzymatic glucose biosensor

Nguyen, Thu-Thuy,Huy, Bui The,Hwang, Seo-Young,Vuong, Nguyen Minh,Pham, Quoc-Thai,Nghia, Nguyen Ngoc,Kirtland, Aaron,Lee, Yong-Ill IOP 2018 Nanotechnology Vol.29 No.20

<P>Cuprous oxide (Cu<SUB>2</SUB>O) nanostructure has been synthesized using an electrochemical method with a two-electrode system. Cu foils were used as electrodes and NH<SUB>2</SUB>(OH) was utilized as the reducing agent. The effects of pH and applied voltages on the morphology of the product were investigated. The morphology and optical properties of Cu<SUB>2</SUB>O particles were characterized using scanning electron microscopy, x-ray diffraction, and diffuse reflectance spectra. The synthesized Cu<SUB>2</SUB>O nanostructures that formed in the vicinity of the anode at 2 V and pH?=?11 showed high uniform distribution, small size, and good electrochemical sensing. These Cu<SUB>2</SUB>O nanoparticles were coated on an Indium tin oxide substrate and applied to detect non-enzyme glucose as excellent biosensors. The non-enzyme glucose biosensors exhibited good performance with high response, good selectivity, wide linear detection range, and a low detection limit at 0.4 <I>μ</I>M. Synthesized Cu<SUB>2</SUB>O nanostructures are potential materials for a non-enzyme glucose biosensor.</P>

Application of Electrocoagulation for Printing Wastewater Treatment: From Laboratory to Pilot Scale

Thuy, Nguyen Thi,Hoan, Nguyen Xuan,Thanh, Dang Van,Khoa, Pham Minh,Tai, Nguyen Thanh,Hoang, Quang Huy,Huy, Nguyen Nhat The Korean Electrochemical Society 2021 Journal of electrochemical science and technology Vol.12 No.1

This study reports for the first time the application of electrocoagulation (EC) from laboratory to pilot scales for the treatment of printing wastewater, a hazardous waste whose treatment and disposal are strictly regulated. The wastewater was taken from three real printing companies with strongly varying characteristics. The treatment process was performed in the laboratory for operational optimization and then applied in the pilot scale. The weight loss of the electrode and the generation of sludge at both scales were compared. The results show that the raw wastewater should be diluted before EC treatment if its COD is higher than about 10,000 mg/L. Pilot scale removal efficiencies of COD and color were slightly lower compared to those obtained from the laboratory scale. At pilot scale, the effluent CODs removal efficiency was 81.9 - 88.9% (final concentration of 448 - 992 mg/L) and color removal efficiency was 95.8 - 98.6% (final level of 89 - 202 Pt-Co) which proved the feasibility of EC treatment as an effective pre-treatment method for printing wastewater as well as other high colored and hard-biodegradable wastewaters.

Knowledge and Attitude Towards Tobacco Smoking among 13-15 Year-Old School Children in Viet Nam - Findings from GYTS 2014

Nguyen, Thanh Huong,Nguyen, Trung Kien,Kim, Bao Giang,Hoang, Van Minh,Phan, Thi Hai,Doan, Thu Huyen,Luong, Ngoc Khue,Nguyen, Thuy Linh,Nguyen, Tuan Lam,Pham, Thi Quynh Nga Asian Pacific Journal of Cancer Prevention 2016 Asian Pacific journal of cancer prevention Vol.17 No.no.sup1

Studies have shown that smoking is a learnt behavior, often initiated during adolescence. This paper aims to describe tobacco-related knowledge, attitude and associations among school adolescents aged 13-15 with exposure to anti-smoking information. Using data from the Global Youth Tobacco Survey (GYTS) in Viet Nam, 2014, knowledge was measured through 4 questions about tobacco use, and attitude was assessed through 3 questions on personal, social and environmental aspects. Students giving most anti-tobacco responses to all questions were considered as having correct knowledge or appropriate attitude or both. Access to anti-smoking information was determined by exposure to any media messages on tobacco control during the past 30 days and teaching in school about the danger of tobacco use during the past 12 months. A substantial percentage of students thought that being near others who smoke might be harmful to them and smoking is harmful to health (89.4% and 89.6% respectively). However, only 46.4% reported that it is definitely difficult to quit smoking and 66.9% thought that smoking for only 1 or 2 years, once stopped, is harmful to health. Slightly more than half of the respondents reported appropriate attitude that young smokers have fewer friends than others and smoking makes them less attractive and less comfortable at social events. Noticing anti-smoking messages in the media together with having lessons in school about the dangers of tobacco substantially increased the likelihood of having correct knowledge, appropriate attitude and both. Despite relatively high awareness about smoking harms, effective educational communication is still highly needed to improve the level of comprehensive knowledge and an appropriate attitude regarding tobacco use.