Raman Scattering Studies of Cu2ZnSnS4 Thin Films: Local Distribution of the Secondary Phase Cu2−xS and the Effect of KCN Etching on Cu2−xS

Trang Thi Thu Nguyen,신해영,김기영,김주리,조윌렴,윤석현,이기두,김진영 한국물리학회 2015 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.66 No.1

We used X-ray diffraction (XRD) and Raman scattering spectroscopy to study Cu2ZnSnS4(CZTS) thin films grown by using an electroplating method. We compared the Raman spectraof the CZTS thin films before and after potassium cyanide (KCN) etching. We observed a phononmode of the secondary phase Cu2−xS both from Cu-rich and Cu-poor CZTS samples before theKCN etching. We found that the intensity of the Cu2−xS-related vibration mode depended on theexcitation wavelength, from which we could estimate the stoichiometry of the Cu2−xS as x = 1. Interestingly, the Cu2−xS phonon is completely removed after the KCN etching. We could also getinformation regarding the local distribution of the secondary phase on the surfaces of the CZTSthin films by using micro-Raman scattering spectroscopy.

Detecting user status from smartphone sensor data

Nguyen, Thu-Trang,Nguyen, Thi-Hau,Nguyen, Ha-Nam,Nguyen, Duc-Nhan,Choi, GyooSeok The International Promotion Agency of Culture Tech 2016 International Journal of Advanced Culture Technolo Vol.4 No.1

Due to the high increment in usage and built-in advanced technology of smartphones, human activity recognition relying on smartphone sensor data has become a focused research area. In order to reduce noise of collected data, most of previous studies assume that smartphones are fixed at certain positions. This strategy is impractical for real life applications. To overcome this issue, we here investigate a framework that allows detecting the status of a traveller as idle or moving regardless the position and the direction of smartphones. The application of our work is to estimate the total energy consumption of a traveller during a trip. A number of experiments have been carried out to show the effectiveness of our framework when travellers are not only walking but also using primitive vehicles like motorbikes.

Raman scattering study of phase transition and vibration modes in MA cation of CH3NH3PbBr3 single crystals

Trang Thi Thu Nguyen,Yejin Kim,Hye Ri Jung,William Jo,Won Seok Woo,Chang Won Ahn,Shinuk Cho,Ill Won Kim,Seokhyun Yoon 한국진공학회 2019 한국진공학회 학술발표회초록집 Vol.2019 No.2

Application of Polyethylene/Modified Fly Ash/Ultra Flow Agent Composites in Vietnam

Nguyen Thuy Chinh,Nguyen Thi Thu Trang,Tran Thi Mai,Nguyen Vu Giang,Tran Huu Trung,Mai Duc Huynh,Thai Hoang 한국고분자학회 2019 한국고분자학회 학술대회 연구논문 초록집 Vol.44 No.1

PLEKHG3 enhances polarized cell migration by activating actin filaments at the cell front

Nguyen, Trang Thi Thu,Park, Wei Sun,Park, Byung Ouk,Kim, Cha Yeon,Oh, Yohan,Kim, Jin Man,Choi, Hana,Kyung, Taeyoon,Kim, Cheol-Hee,Lee, Gabsang,Hahn, Klaus M.,Meyer, Tobias,Heo, Won Do National Academy of Sciences 2016 PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF Vol.113 No.36

<P>Cells migrate by directing Ras-related C3 botulinum toxin substrate 1 (Rac1) and cell division control protein 42 (Cdc42) activities and by polymerizing actin toward the leading edge of the cell. Previous studies have proposed that this polarization process requires a local positive feedback in the leading edge involving Rac small GTPase and actin polymerization with PI3K likely playing a coordinating role. Here, we show that the pleckstrin homology and RhoGEF domain containing G3 (PLEKHG3) is a PI3K-regulated Rho guanine nucleotide exchange factor (RhoGEF) for Rac1 and Cdc42 that selectively binds to newly polymerized actin at the leading edge of migrating fibroblasts. Optogenetic inactivation of PLEKHG3 showed that PLEKHG3 is indispensable both for inducing and for maintaining cell polarity. By selectively binding to newly polymerized actin, PLEKHG3 promotes local Rac1/Cdc42 activation to induce more local actin polymerization, which in turn promotes the recruitment of more PLEKHG3 to induce and maintain cell front. Thus, autocatalytic reinforcement of PLEKHG3 localization to the leading edge of the cell provides a molecular basis for the proposed positive feedback loop that is required for cell polarization and directed migration.</P>

Detecting user status from smartphone sensor data

Thu-Trang Nguyen,Thi-Hau Nguyen,Ha-Nam Nguyen,Duc-Nhan Nguyen,GyooSeok Choi 국제문화기술진흥원 2016 International Journal of Advanced Culture Technolo Vol.4 No.1

Due to the high increment in usage and built-in advanced technology of smartphones, human activity recognition relying on smartphone sensor data has become a focused research area. In order to reduce noise of collected data, most of previous studies assume that smartphones are fixed at certain positions. This strategy is impractical for real life applications. To overcome this issue, we here investigate a framework that allows detecting the status of a traveller as idle or moving regardless the position and the direction of smartphones. The application of our work is to estimate the total energy consumption of a traveller during a trip. A number of experiments have been carried out to show the effectiveness of our framework when travellers are not only walking but also using primitive vehicles like motorbikes.

Compounds from the Aerial Parts of Aceriphyllum rossii and Their Cytotoxic Activity

( Thi Thu Trang Tran ),( Thi Yen Nguyen ),( Manh Hung Tran ),( Kwon Yeon Weon ),( Mi Hee Woo ),( Byung Sun Min ) 한국생약학회 2014 Natural Product Sciences Vol.20 No.3

The purification of the MeOH extracts from the aerial parts of Aceriphyllum rossii Engler (Saxifragaceae) using column chromatography furnished fourteen compounds (1 - 14). The chemical structures of the isolated compounds were determined using mainly nuclear magnetic resonance spectra and mass spectrometry. All the isolated compounds were tested for their cytotoxic activity against LH-60, MCF-7 and HeLa cancer cells in vitro using a MTT assay method. Compounds possessing an olean-triterpenoid skeleton entirely exhibit dose dependent cytotoxic activity. These findings partially confirmed the anticancer effect of this medicinal plant, suggesting a further study on the anticancer potential of the triterpenoid structure in compounds from this plant.

A Comparative Study on the Self-help Approach in Rural Development between Vietnam’s New Rural Development and Korea’s Saemaul Undong

Do Thu Trang,Nguyen Thi My Hanh,Vu Thu Trang 대외경제정책연구원 2016 East Asian Economic Review Vol.20 No.1

Vietnam’s “Doi Moi”, initiated in 1986, translated to high economic growth and rapid urbanization for the country, but also widened the gap between rural and urban areas. Vietnam’s National Target Program on New Rural Development for 2010- 2020 was aimed at developing the rural economy and improving the living standards of rural people, but after five years the urban-rural gap remains substantial. Two of the main reasons are the lack of investment capital and lack of effective ways to mobilize community involvement. In contrast, during the 1970s, rural areas in Korea experienced huge improvements under the “Saemaul Undong” movement. The program’s success at promoting sustainable development in Korea’s rural areas has inspired rural programs in other developing countries. In this paper, we compare and contrast the two movements to provide explanations for the different results between the two countries. Based on this analysis, and policy implications stemming from it, we recommend resource mobilization strategies to change villagers’ attitude and increase their involvement in Vietnam’s rural development movement, aligning with the inclusivity principle “people know, people discuss, people do and people check”.

Impacts of Corporate Social Responsibility and Authenticity on Brand Loyalty: Evidence from the Chain Coffee Shop Industry in Vietnam

MAI, Thi Cam Tu,NGUYEN, Hong Son,PHAN, Nguyen Ngoc Diem,LE, Minh Hang,LUU, Phuong Khanh,NGUYEN, Thi Thu Thao,NGUYEN, Thi Thu Trang Korea Distribution Science Association 2022 The Journal of Asian Finance, Economics and Busine Vol.9 No.6

This study examines the impact of CSR and its authenticity on customer loyalty through the brand image in the chain coffee shop industry. Using qualitative and quantitative methods, 601 survey questionnaires were distributed, of which 491 were analyzed. The results show that CSR has a positive impact on brand image and customer loyalty. In addition, authenticity does not moderate the impact of CSR on brand image and loyalty, as it is difficult for customers to verify the authenticity of CSR action programs. This study emphasizes the importance of CSR action programs and authenticity for businesses to sustainably enhance their distinctive brand image and customer loyalty. Therefore, for sustainable development in the future, managers of coffee shop chains need to focus on the following issues. First, the most important thing is the right awareness of businesses regarding CSR and CSR authenticity. Third, businesses should strengthen the transparency of CSR action programs in various media so that consumers can easily verify authenticity, to increase brand image and improve customer loyalty.

Effect of the Morphological Characteristic and Composition of Electrospun Polyvinylidene Fluoride/Graphene Oxide Membrane on Its Pb2+ Adsorption Capacity

Thuy Thi Thu Nguyen,Huu The Nguyen,Hai Thi Trinh,Trang Thi Thu Bui,Anh-Tuan Le,Tran Quang Huy 한국고분자학회 2022 Macromolecular Research Vol.30 No.2

In this study, the Pb2+ adsorption capacity of electrospun polyvinylidene fluoride/graphene oxide (PVDF/GO) membranes with different morphological characteristics and compositions were comprehensively compared. Firstly, the chemical characteristics, morphological characteristics and hydrophobicity relating to the adsorption capacity of electrospun PVDF/GO membranes were investigated through Fourier transform infrared spectroscopy, Raman spectroscopy, energy-dispersive X-ray spectroscopy, scanning electron microscopy and water contact angle measurement. Adsorption analysis showed that the adsorption performance of electrospun PVDF/ GO increased as GO contents increased. Variations in the average diameter of electrospun PVDF/GO fibres in the range of several micrometres did not cause a distinguishable change in their adsorption capacity. Electrospun PVDF/GO membranes without a porous structure inhibited a low adsorption capacity although they contained a high composition of GO. The modification of electrospun PVDF/GO membranes by adding PEG increased the distribution of GO on the surface of fibres, resulting in a more hydrophilic fibre surface and a notable increase in Pb2+ adsorption. The adsorption behaviour of Pb2+ onto electrospun PVDF/GO/PEG membranes was found to be dependent on contact time and pH. Reusability analysis indicated that the electrospun PVDF/GO/PEG membrane maintained a Pb2+ removal rate of over 80% after six adsorption-desorption cycles. Therefore, electrospun PVDF/GO/PEG membranes might be a promising adsorption material used in filtration systems for heavy metal removal.