Continuous Behavior of Using Food Delivery Mobile Applications in Vietnam after Covid-19 Pandemic

Ha Thu LUONG(Ha Thu LUONG ),Nhi Lan DAO(Nhi Lan DAO ),Trang Thu NGUYEN(Trang Thu NGUYEN ),Uyen Thu Thi LA(Uyen Thu Thi LA ),Na Thi Le TRAN(Na Thi Le TRAN ),Hoa Thi DUONG(Hoa Thi DUONG ) 한국유통과학회 2023 유통과학연구 Vol.21 No.3

Purpose: During and after Covid-19 pandemic, technology has emerged as a key factor in supporting the recovery of the economy and the rise of living standards. This study examines seven factors affecting the intention of food delivery apps usage, which include Performance Expectancy, Effort Expectancy, Social Influence, Hedonic Motivation, Price Value, and Habit, and how much influence they have on the customers' behavioral continuance of food delivery apps after Covid-19 Pandemic. Research methodology: This research is a quantitative descriptive research with 473 qualified respondents from 550 respondents collected. Besides using the UTAUT2 model (Venkatesh et al., 2012), Information Quality was added to give a better explanation for the consumers’ intention towards continuance behavior using food delivery apps. The collected data is then processed using SPSS 22.0. Results: Habit factors and Information Quality factors have significant positive effects on promoting food delivery apps usage intention, which in turn influences continuance behavior. In addition, Habit factors and Information Quality factors together have an effect of 48.57% on Behavioral Intention. Conclusion: The result proves that positive habits and food information quality can increase the usage intention towards the behavioral continuance of consumers. Higher usage frequency can be improved by increasing these two factors.

Ultra-broadband and flexible metamaterial absorber based on MoS2 cuboids with Mie resonances

Ha Duong Thi,Nam Man Hoai,Tung Bui Son,Khuyen Bui Xuan,Lam Vu Dinh,Le-Van Quynh 한국물리학회 2023 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.82 No.11

In this work, we present a type of fexible and broadband metamaterial absorber operating in the GHz range. The proposed structure consists of three layers: a periodic square-shaped array made of molybdenum disulfde (MoS2) on the top, a continuous polyimide layer in the middle and a continuous copper layer at the bottom. For fat model, the proposed absorber exhibits a broadband absorption in the frequency range of 10.1–17.6 GHz with an absorption of more than 90% under normal incidence. Due to the symmetry of structure, the absorption feature is polarization-insensitive. The absorption remains above 80% in the frequency range of 11.1–15.6 GHz when the incident angle is up to 60° for TE-polarized wave, while the absorption is higher than 90% in the frequency range of 13.5–18 GHz for incident angles up to 60° for TM-polarized wave. For bending model, the absorption is signifcantly expanded when the bending radius decreases to under 100 mm. The physical mechanism of the absorption properties is explained in detail by the electric feld distribution, the magnetic feld distribution following the Mie resonance theory and infuence of the loss of MoS2. Obtained results in the work might contribute to the development of potential applications based on metamaterials in the microwave region such as imaging, protecting and light emitting devices.

The Antecedents of Online Purchase Intention of Generation Z and Millennials toward Organic Cosmetics in an Emerging Economy

Thi Thu Ha Nguyen,Hiep-Hung Pham,Ngoc Linh Dao,Hong Hanh Dao,Thi Thuy Nuong Duong,Thi Ha Chu The International Academy of Global Business and T 2023 The International Academy of Global Business and T Vol.19 No.6

Purpose - Based on the extended theory of planned behavior (TPB), this study aims to investigate the antecedents of online purchase behavior toward organic cosmetics for Generation Z (Gen Z) and Millennials by focusing on the impact of subjective norms, health consciousness, trust, attitude, and intention. Design/Methodology/Approach - A survey method using an online questionnaire was adopted to collect data from 341 Gen Z and Millennial consumers in Vietnam. The collected data were then analyzed using structural equation modeling (SEM). Findings - The results of the study showed that, among antecedents, that attitude has the strongest impact on the purchase intention of online customers toward organic cosmetics, followed by trust and subjective norms. Interestingly, health consciousness has also been found to significantly impact Gen Z and Millennial online purchase intention toward organic cosmetics. Research Implications - This paper extends the academic literature on purchase intention toward green products. More importantly, to the best of the authors’ knowledge, this study is among the first to examine the antecedents of online purchase intention toward the organic cosmetics of Gen Z and Millennials in an emerging economy, Vietnam. The findings offer important implications for cosmetics companies, retailers, and other stakeholders to have deeper insights into factors influencing young Vietnamese consumer intentions toward purchasing organic beauty products online.

Facile synthesis of ZnBi2O4-graphite composites as highly active visible-light photocatalyst for the mineralization of rhodamine B

Nguyen Thi Mai Tho,Bui The Huy,Dang Nguyen Nha Khanh,Ho Nguyen Nhat Ha,Vu Quang Huy,Ngo Thi Tuong Vy,Do Manh Huy,Duong Phuoc Dat,Nguyen Thi Kim Phuong 한국화학공학회 2018 Korean Journal of Chemical Engineering Vol.35 No.12

Novel highly active visible-light photocatalysts in the form of zinc bismuth oxide (ZnBi2O4) and graphite hybrid composites were prepared by coupling via a co-precipitation method followed by calcination at 450 oC. The asprepared ZnBi2O4-graphite hybrid composites were tested for the degradation of rhodamine B (RhB) solutions under visible-light irradiation. The existence of strong electronic coupling between the two components within the ZnBi2O4- graphite heterostructure suppressed the photogenerated recombination of electrons and holes to a remarkable extent. The prepared composite exhibited excellent photocatalytic activity, leading to more than 93% of RhB degradation at an initial concentration of 50mg·L1 with 1.0 g catalyst per liter in 150min. The excellent visible-light photocatalytic mineralization of ZnBi2O4-1.0graphite in comparison with pristine ZnBi2O4 could be attributed to synergetic effects, charge transfer between ZnBi2O4 and graphite, and the separation efficiency of the photogenerated electrons and holes. The photo-induced h+ and the superoxide anion were the major active species responsible for the photodegradation process. The results demonstrate the feasibility of ZnBi2O4-1.0graphite as a potential heterogeneous photocatalyst for environmental remediation.

How Destination Image Factors Affect Domestic Tourists Revisit Intention to Ba Ria-Vung Tau Province, Vietnam

GIAO, Ha Nam Khanh,NGAN, Nguyen Thi Kim,PHUC, Nguyen Pham Hanh,TUAN, Huynh Quoc,HONG, Ha Kim,ANH, Huynh Diep Tram,NHU, Duong Thi Huynh,LAN, NgoThi Korea Distribution Science Association 2020 The Journal of Asian Finance, Economics and Busine Vol.7 No.6

This research examines the affect of destination image factors on revisit intention of domestic tourists at Ba Ria Vung-Tau (BRVT), by questioning directly 510 domestic tourists. The convenient sampling method is used in dividing the crowds into four groups; the four main surveyed areas in BRVT are: Vung Tau, Long Hai-Phuoc Hai, Xuyen Moc and Con Dao. A combination of qualitative and quantitative methodologies were utilized.A focus group of 10 domestic tourists wasset up to review and explore the variousfactors as well as the conceptual model. An in-depth interview with 12 participants was developed to fine-tune measurement items. The questionnaire applied a 5-point Likert scale. Checking the reliability by Cronbach's Alpha, exploratory factor analyzing and linear multiple regression were used with the SPSS program. The results show that there are eight main destination image factors affecting domestic tourists revisit intention to BRVT using linear regression and arranged by decreasing importance: Infrastructure, Variety Seeking, Accessibility, Local food, Atmosphere, Environment, Price Value, Leisure and Entertainment. From that, the research offers some suggestions and policy recommendations for the tourism business and provincial policy-makers to identify the main issues and develop better customer services to increase domestic tourists'revisit intention.

Preliminary study of doxycycline adsorption from aqueous solution on alkaline modified biochar derived from banana peel

Van-Truc Nguyen,Thanh-Binh Nguyen,Thi-Dieu-Hien Vo,Nguyen Duy Dat,Thi-Kim Quyen Vo,Xuan Cuong Nguyen,Viet-Cuong Dinh,Thi-Ngoc-Chau Le,Thi-Giang-Huong Duong,Manh-Ha Bui,Xuan-Thanh Bui 대한환경공학회 2023 Environmental Engineering Research Vol.29 No.3

This study explores the adsorption of doxycycline (DOX) from aqueous solutions onto biochar derived from banana peel, which was prepared using a potassium hydroxide activation method (KOH-BPB). The biochar properties were characterized based on morphology, surface area (SBET of 710.241 ㎡ g<SUP>−1</SUP>), functional groups, and surface charge (pHPZC = 7.7). Parameters, including initial pH, DOX concentration, and ionic strength, that influenced the DOX adsorption capacity of KOH-BPB were examined. Adsorption equilibrium of DOX on KOH-BPB was assessed through four isothermal models: the Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich models. The obtained data were most compatible with the Langmuir model (R² = 0.9879). KOH-BPB has a maximum DOX absorption capacity of 121.95 mg g<SUP>-1</SUP> which exceeds that of many comparable absorbents. The maximum DOX removal was 96.7% at pH 6, a DOX concentration of 20 mg L<SUP>-1</SUP>, and a KOH-BPB dose of 1.0g L<SUP>-1</SUP>. These findings reveal that biochar from banana peel effectively removes antibiotic residues from water. This study provides a potential, low-cost, and environmentally friendly adsorbent.

The Effect of Social Capital on Social Entrepreneurial Intention among Vietnamese Students

HA, Ngoc Thang,DOAN, Xuan Hau,VU, Trong Nghia,NGUYEN, Thi Phuong Linh,PHAN, Thanh Hoa,DUONG, Cong Doanh Korea Distribution Science Association 2020 The Journal of Asian Finance, Economics and Busine Vol.7 No.8

This study develops the model to estimate the links between social capital, social entrepreneurial self-efficacy, perceived desirability and social entrepreneurial intention. Besides exploring the direct impacts of social capital, social entrepreneurial self-efficacy, and perceived desirability on social entrepreneurial intention, this study also focus on discovering the mediating roles of perceived desirability and social entrepreneurial self-efficacy on this relationship. Throughout adopting measures from some previous studies, the authors design the questionnaires and distribute to students in Vietnam. The study presents some demographic information of 289 students, who are studying at university and colleges in Vietnam. Then, the validity and reliability of scales are assessed using the value of Cronbach's alpha, Exploratory Factor Analysis (EFA) and Confirmatory Factor Analysis (CFA). In addition, by utilizing the structural modeling structure (SEM), the authors show that social capital plays the important role in shaping social entrepreneurial self-efficacy, perceived desirability, and social entrepreneurial intention. Interestingly, besides the direct effects on social entrepreneurial intention, perceived desirability and social entrepreneurial self-efficacy also mediate the correlation between social capital and social entrepreneurial intention. Also, with the interesting findings of the study, the authors propose several recommendations for policy-makers, educators and academics to promote the social entrepreneurship and innovation among Vietnamese students.

Factors Affecting Corporate Investment Decision: Evidence from Vietnamese Economic Groups

Duong Thuy PHAN,Ha Thi NGUYEN 한국유통과학회 2020 The Journal of Asian Finance, Economics and Busine Vol.7 No.11

This paper analyzes factors affecting corporate investment decisions in economic groups listed on the Vietnam stock market. The panel data of the research sample includes 39 economic groups listed on the Vietnam stock market from 2009 to 2019. The Generalized Least Square (GLS) is employed to address econometric issues and to improve the accuracy of the regression coefficients. In this research, the investment rate is a dependent variable. Cash-flow (CF), Investment opportunities (ROA), Fixed capital intensity (FCI), Leverage (LEV), Sales growth (GR), Size (SZ), Business risk (RISK) are independent variables in the study. The model results show that cash flow and sales growth have the same impact on investment decisions of economic groups in Vietnam. In addition, investment opportunities have a negative impact on the capital investment decisions of economic groups. The remaining factors include fixed capital intensity, leverage, firm size, and business risks that have a weak and insignificant impact on capital investment decisions of economic groups in Vietnam. The findings of this article are useful for business administrators, and helping business managers make the right financial decisions. Besides, the research results are also meaningful to money management agencies. The authors recommend that the State Bank of Vietnam should maintain a sustainable monetary policy.

Buried objects detection in heterogeneous environment using UWB systems combined with curve fitting method

Nguyen Thi Huyen,Duong Duc Ha,Pham Thanh Hiep 한국통신학회 2020 ICT Express Vol.6 No.4

A new method is proposed to improve the accuracy of locating buried objects in heterogeneous environments using a shifted time pulses with radio impulse ultra wide band (IR-UWB), time-hopping pulse position modulation (TH-BPSK UWB), binary phase shift keying (TH-BPSK UWB) systems combine with the least square curve fitting method (LSCFM). The analytical expression is validated by simulation and the locating errors used to assess the performance of systems. The numerical results indicate that the proposed method has higher accuracy than the conventional ones.

Lanostane Triterpenoids from Ganoderma tropicum Collected in Vietnam and Their Nitroblue Tetrazolium Reductive Activity In Vitro

Nguyen Thi Duyen,Nguyen Minh Khoi,Phan Nguyen Truong Thang,Duong Minh Tan,Tran Viet Hung,Do Thi Ha 한국생약학회 2020 Natural Product Sciences Vol.26 No.4

A new compound, 3β-acetoxylanosta-7,9(11),24-triene-26-al (3), and seven known compounds (1 – 2 and 4 – 8) were isolated from Ganoderma tropicum (Jung.) Bres. collected in Tay Nguyen, Vietnam. The structures of these compounds were determined by one- and two-dimensional nuclear magnetic resonance spectroscopy, electrospray ionization mass spectrometry (ESI-MS), and high-resolution ESI-MS, and by comparison with literature data. All of the isolated compounds were tested for nitroblue tetrazolium (NBT) reduction activity in Saccharomyces cerevisiae-stimulated RAW 246.7 cells. Among them, compounds 2 – 4 and 6 – 8 enhanced the NBT reduction in a dose-dependent manner.