Preference for Green Packaging in Consumer Product Choices: Empirical Evidence from Gen Z Consumers in Vietnam

Lan NGUYEN(Lan NGUYEN ),Trang Minh NGUYEN(Trang Minh NGUYEN ),Quyen TRINH(Quyen TRINH ),Nhu Anh DAO(Nhu Anh DAO ) 한국유통과학회 2023 The Journal of Asian Finance, Economics and Busine Vol.10 No.2

Recently, the call for better accountability and social responsibility from corporations has been regularly voiced, both in the academic literature and in public discussions. This poses a challenge to the existing literature in understanding consumption behaviors to direct them toward sustainable development. This study investigates the purchase intention of Gen Z consumers in Vietnam with green packaging products. Data were collected from 914 respondents by online questionnaire and then analyzed using OLS. The results suggest the significant influence of customers’ income and packaging in driving customers’ intention to use environmentally-friendly products. Specifically, consumers in a higher income class participate more actively in green purchases. However, problems associated with inadequate packaging are also illustrated, resulting in the poor perception of green messages and poor practice of ecological actions. Besides, subjective norms and green trust are found to be adversely related to green consumer intention. In addition, gender disparity in green behavior is reported, where female consumers show a higher tendency to ecological consumption than their male counterparts. Other demographic factors are also included in the model as control variables, which are age, education, price, environmental literacy, environmental concern, and psychological awareness, but they do not have a significant impact on green purchase intention.

Application of Total Quality Management in Developing Quality Assessment Model: The Case of Vietnamese Higher Education

Quyen Le Hoang Thuy To NGUYEN,Du Van NGUYEN,Ngoc Nguyen Mong CHU,Van Hong TRAN 한국유통과학회 2020 The Journal of Asian Finance, Economics and Busine Vol.7 No.11

The shift from elite education to mass education in Vietnam has met the demand for education for everybody as well as for quality human resource talent for an emerging nation. Under the resource constraint, understanding the quality dimensions of education and its priority level is important for effective and efficient policies. This study was carried out using both qualitative and quantitative methodologies to develop quality criteria and a ranking model. Two rounds of in-depth interviews were conducted with fifteen experts in the field, who were rectors, employers, and recruitment specialists to develop the quality framework applied in Vietnamese universities under total quality management (TQM), starting from the input of the senior secondary school leavers, through a teaching process to the output. The first round of interviews were unstructured questionnaires designed to explore the main factors in quality assessment model. The second round affirmed the experts’ agreement on the assessment model. Then, fuzzy logic was applied to rank eight criteria in the quality assessment model into priority order: cost, teaching and administrative staff, leadership, curriculum, student-related factors, internationalization, admissions, and campus. The results are critical for identifying the necessary actions to enhance the education quality and to further research on the optimal quality model.

Highly effective adsorption of organic dyes from aqueous solutions on longan seed-derived activated carbon

Nguyen Van Hung,Bui Thi Minh Nguyet,Nguyen Huu Nghi,Nguyen Mau Thanh,Nguyen Duc Vu Quyen,Vo Thang Nguyen,Dao Ngoc Nhiem,Dinh Quang Khieu 대한환경공학회 2023 Environmental Engineering Research Vol.28 No.3

In this study, longan seeds - an agricultural by-product was used to fabricate activated carbon (LSAC) through two-step pyrolysis with pre-carbonization at low temperature in the first step and then activation by H3PO4. LSAC with large surface area and porous structure exhibits an excellent capacity of absorption towards both cationic dyes (methylene blue (MB), rhodamine-B (RhB)) and anionic dyes (methyl orange (MO), congo red (CR)). Experimental data can be described well by the pseudo-second kinetic model. The maximum adsorption capacity based on Langmuir isotherm model was found as 502.84; 397.77; 464.66 and 350.64 mg.g−1 for MB, RhB, MO and CR, respectively. The adsorption of MB, RhB and CR on LSAC is spontaneous and endothermic, while that for MO is spontaneous but exothermic. Furthermore, the adsorption mechanism of dyes on LSAC was also studied showing that it can occur by electrostatic interaction, hydrogen bonding, the filling of pores involving the interaction between dye ions with specific functional groups such as –OH, –COOH, –NH2 and –PO43− on the LSAC surface. These results suggest that LSAC material may be envisaged as a promising adsorbent for treatment of wastewater in textile industries.

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.

Multi-Carrier Differential Chaos-Shift Keying With Repeated Spreading Sequence

Nguyen Xuan Quyen 한국통신학회 2018 Journal of communications and networks Vol.20 No.3

This paper proposes a multi-carrier differential chaosshiftkeying (MC-DCSK) system using repeated spreading sequence(RSS), namely RSS-MC-DCSK, for chaos-based wirelesscommunications. In the proposed system, instead of transmittingthe chaotic spreading sequence on a predefined subcarrier asin conventional MC-DCSK, a DCSK-modulated signal, of whicheach two-bit duration consisting of reference and data-bearing sequencesis sent via this subcarrier. Meanwhile, a repeated spreadingsequence is produced by copying the reference sequence of theDCSK-modulated signal to the same and next bit periods. Theparallel bit streams are multiplied with this RSS and the resultingsignals are then conveyed by corresponding subcarriers. Inthe receiver, the signal retrieved from the predefined subcarrieris DCSK-demodulated and simultaneously used to recover the repeatedspreading sequence. The correlative demodulation is performedfor all the signals retrieved from the remaining subcarriersto decode the data. The structure and operation of the proposedsystem are described. Bit error rate (BER) performance under amultipath Rayleigh fading channel is theoretically analyzed andthen verified by numerical simulations. In addition, the BER performance,energy and spectral efficiencies of RSS-MC-DCSK areevaluated in comparison to those of MC-DCSK.

Multi-Carrier Differential Chaos-Shift Keying with Repeated Spreading Sequence

Quyen, Nguyen Xuan The Korean Institute of Communications and Informa 2018 Journal of communications and networks Vol.20 No.3

This paper proposes a multi-carrier differential chaos-shift keying (MC-DCSK) system using repeated spreading sequence (RSS), namely RSS-MC-DCSK, for chaos-based wireless communications. In the proposed system, instead of transmitting the chaotic spreading sequence on a predefined subcarrier as in conventional MC-DCSK, a DCSK-modulated signal, of which each two-bit duration consisting of reference and data-bearing sequences is sent via this subcarrier. Meanwhile, a repeated spreading sequence is produced by copying the reference sequence of the DCSK-modulated signal to the same and next bit periods. The parallel bit streams are multiplied with this RSS and the resulting signals are then conveyed by corresponding subcarriers. In the receiver, the signal retrieved from the predefined subcarrier is DCSK-demodulated and simultaneously used to recover the repeated spreading sequence. The correlative demodulation is performed for all the signals retrieved from the remaining subcarriers to decode the data. The structure and operation of the proposed system are described. Bit error rate (BER) performance under a multipath Rayleigh fading channel is theoretically analyzed and then verified by numerical simulations. In addition, the BER performance, energy and spectral efficiencies of RSS-MC-DCSK are evaluated in comparison to those of MC-DCSK.

Drynaria bonii spore culture: optimization of culture conditions and analysis of gametophyte and sporophyte development

Quyen Van Nguyen,Hang Thi Khuat,Yen‑Ngoc Thi Nguyen,Dung Thi Vu,Thu‑Ha Bui,부경환 한국식물생명공학회 2020 Plant biotechnology reports Vol.14 No.5

Drynaria bonii H. Christ is a medicinal plant that has traditionally been used for the treatment of chronic diseases and tuberculosis. However, D. bonii has not yet been cultivated or propagated. In this study, we optimized the conditions for the spore culture of D. bonii to produce sporophytes. First, we evaluated the efects of various factors, such as temperature, light intensity, potting material, and pH, on spore germination and early gametophyte development. Under optimal culture conditions, 95–99% of the spores germinated within 2 weeks of culture. Next, based on these results, we established a culture system for gametophyte development and sporophyte production. Mature gametophytes frst appeared 5 months post-germination (mpg), and at 12 mpg, the rate of production of heart-shaped gametophytes reached 56.6%. Sporophytes at the early frst-leaf stage frst appeared at 6 mpg, and at 12 mpg, the rate of formation of sporophytes reached 15.4%. Interestingly, 6.3% of all gametophytes produced multiple sporophytes. Additionally, 42–62% of the gametophytes also produced multiple secondary gametophytes, indicating a high potential of D. bonii gametophytes to generate new gametophytes and, subsequently, sporophytes. When transferred to new trays or pots, sporophytes grew well and showed 100% survival. Overall, we conclude that this spore culture system can be successfully used for the propagation of D. bonii sporophytes.

Critical Factors Affecting Construction Price Index: An Integrated Fuzzy Logic and Analytical Hierarchy Process

NGUYEN, Phong Thanh,NGUYEN, Quyen Le Hoang Thuy To Korea Distribution Science Association 2020 The Journal of Asian Finance, Economics and Busine Vol.7 No.8

Nowadays, many construction engineering and technology enterprises are evolving to find that prosperity is driven and inspired by an open economy with dynamic markets and fierce multifaceted competition. Besides brand and product uniqueness, the ability to quickly provide customers with quotes are matters of concern. Such a requirement for prompt cost estimation of construction investment projects with the use of a construction price index poses a significant challenge to contractors. This is because the nature of the construction industry is shaped by changes in domestic and foreign economic factors, socio-financial issues, and is under the influence of various micro and macro factors. This paper presents a fuzzy decision-making approach for calculating critical factors that affect the construction price index. A qualitative approach was implemented based on in-depth interviews of experts in the construction industry in Vietnam. A synthetic comparison matrix was calculated using Buckley approach. The CoA approach was applied to defuzzified the fuzzy weights of factors that affect the construction price index. The research results show that the top five critical factors affecting the construction price index in Vietnam are (1) consumer price index, (2) gross domestic product, (3) basic interest rate, (4) foreign exchange rate, and (5) total export and import.

Effect of plant growth regulator combination and culture period on in vitro regeneration of spinach (Spinacia oleracea L.)

Quyen Van Nguyen,선현진,부경환,이도성,이지현,임평옥,이효연,Key Zung Riu,이동선 한국식물생명공학회 2013 Plant biotechnology reports Vol.7 No.1

The objective of this study was to develop an efficient system for the regeneration of spinach plants (Spinacia oleracea L.) by investigating the factors influencing callus and shoot induction. All plant growth regulator (PGR) combinations tested induced callus with high frequency (73–100 %), and the combination of 5 lM a-naphthaleneacetic acid (NAA), 10 lM 6-benzyladenine (BA) and 0.1 lM gibberellic acid (GA3) had the most significant effect on callus growth in term of weight (120.98 ± 22.56 mg). A high auxin-containing medium induced competent callus for shoot formation, while high cytokinin-containing media enhanced callus growth and made callus incompetent for shoot regeneration. Longer periods of callus induction in a high auxin-containing medium were required to form competent callus and led to a high regeneration capacity. The PGR combination shift from a high auxin to cytokinin ratio (ACR) to a low ACR resulted in highly efficient regeneration. Among the regeneration systems tested, the combination of 10 lM NAA and 0.3 lM GA3 for callus induction for 6 weeks followed by 2 lM NAA and 5 lM BA resulted in the highest plant regeneration frequency (83.33 ± 6.43 %) andthe highest number of plantlets per explant (7.93 ± 1.24). Somatic embryos at cotyledonary stage and plantlets were transferred to PGR-free medium to establish whole plants. Regenerated female plants grew well to maturity in the greenhouse (77.17 ± 9.80 %) and produced seeds (175.21 ± 28.01 firm seeds per plant).

Evaluation Factors Influencing Construction Price Index in Fuzzy Uncertainty Environment

NGUYEN, Phong Thanh,HUYNH, Vy Dang Bich,NGUYEN, Quyen Le Hoang Thuy To Korea Distribution Science Association 2021 The Journal of Asian Finance, Economics and Busine Vol.8 No.2

In recent years, Vietnam's economic growth rate has been attributed to the growth of many well-managed industries within Southeast Asia. Among them is the civil construction industry. Construction projects typically take a long time to complete and require a huge budget. Many socio-economic variables and factors affect total construction project costs due to market fluctuations. In recent years, crucial socioeconomic development indicators of construction reached a fairly high growth rate. Also, most infrastructure and construction projects have a high degree of complexity and uncertainty. This makes it challenging to predict the accurate project price. These challenges raise the need to recognize significant factors that influence the construction price index of civil buildings in Vietnam, both micro and macro. Therefore, this paper presents critical factors that affect the construction price index using the fuzzy extent analysis process in an uncertain environment. This proposed quantitative model is expected to reflect the uncertainty in the process of evaluating and ranking the influencing factors of the construction price index in Vietnam. The research results would also allow project stakeholders to be more informed of the factors affecting the construction price index in the context of Vietnam's civil construction industry. They also enable construction contractors to estimate project costs and bid rates better, enhancing their project and risk management performance.