74 research outputs found

    Effect of plant growth regulators on growth and lipid accumulation of microalgal Haematococcus pluvialis Flotow in two-stage culture

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    Haematococcus pluvialis cells were cultured in aerated liquid Bold’s Basal medium in two-stage (initial stage during in 7 weeks for increased biomass growth and second stage during in 3 weeks for increased lipid accumulation) with different volumes 250 mL, 10 L, and 1,000 L. With a volume of 250 mL, the medium was supplied with benzyl adenine (BA), indole-3-acetic acid (IAA) or gibberellic acid (GA3) at concentration from 0.1 - 0.2 mg/L in initial stage and IAA or GA3 at concentration from 0.1 - 0.2 mg/L in second stage. After 10 weeks of culture, results showed that supplement of 0.1 mg/L BA in initial stage and 0.125 mg/L IAA in second stage increased cell density, and microalgal cells had green color with a spherical shape. On the contrary, supplement of 0.15 mg/L IAA in initial stage and 0.175 mg/L GA3 in second stage increased lipid accumulation, and microalgal cells had red color with a spherical shape. With a volume of 10 L, the medium was supplied with 0.1 mg/L BA in initial stage, and treated with separation or combination from 2 - 3 of these factors (nitrogen starvation, 0.5% NaCl, 4.98 mg/L FeSO4) were applied in second stage. The result showed that the cultures was treated with nitrogen starvation increased dry biomass and biofuel, but treated with 4.98 mg/L FeSO4 only increased biofuel. With a volume of 1,000 L, microalgal cells were cultured in BB liquid medium in initial stage, and treated with 4.98 mg/L FeSO4 increased fresh 78.67 mg/mL and dry biomass 2.05 mg/L and total lipid content 28.24 %/ DW

    Factors affecting intention to purchase organic agriculture products among Vietnamese

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    Globally, customer intention to purchase has become the essential part of the product and organization's success in the market. More recently, the idea has captured the attention of academic and policymakers alike. Therefore, the current article analyses product quality features such as agreeableness, emotional stability conscientiousness, openness to experience and extroversion on the intention to purchase organic agricultural products in the context of Vietnam. The study also analyses the mediating role of customer satisfaction between the association of product quality features and intention to purchase organic products in Vietnam. The present study uses questionnaires to collect data pertaining to the health sector of Vietnam. The current study employs the smart-PLS to analyze the constructs and items' reliability as well as the association among constructs. The results show that product quality features except extroversion have a positive and significant association with intention to purchase organic products in Vietnam. The results also reveal that customer satisfaction significantly and positively mediates among the associations of product quality features and intention to purchase organic products in Vietnam. This study is suitable for policymakers while formulating policies that may directly or indirectly affect customers' intention to purchase organic agricultural products.Luong Thu Thuy (Faculty of Economics, Academy of Finance, Vietnam), Tran Thi Phuong Diu (Faculty of Economics, Academy of Finance, Vietnam), Nguyen Dinh Hoan (Faculty of Economics, Academy of Finance, Vietnam), Vu Viet Ninh (Faculty of Economics, Academy of Finance, Vietnam), Nguyen Thi Thuy Nga (Faculty of Economics, Academy of Finance, Vietnam)Includes bibliographical reference

    Bridging Cultures in Academia: The Role of Mindfulness in Enhancing Intercultural Communication and Social Capital among Scholars

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    Studies that comprehensively incorporate mindfulness therapies and the theory of intercultural communication into the investigation of social capital are lacking in the body of existing literature. This restricts our comprehension of how these important components interact and affect social relationships in academic communities as a whole. Therefore, the purpose of this study is to investigate how mindfulness practices affect cross-cultural communication and, in turn, build social capital in academic environments. A mixed method was adopted in the study. In the first stage, focused group interviews are employed in the first stage with seven groups of nine Australian alumni, for a total of 63 participants who have experience conducting research and teaching abroad or in multicultural settings. In the second stage, 149 alumni were surveyed, and Process Macro SPSS\u27s Hayes model was used to analyse the data. The results showed that those who practice mindfulness are more likely to approach cross-cultural encounters with a greater awareness of and respect for different points of view. According to the findings, mindfulness can be a potent instrument for boosting perception of the community, networking, trust and safety, scholarly participation, citizen power, life values and diverse perspectives among academics. Scholars who engage in mindfulness practices have the potential to cultivate closer ties within academic communities, which could result in joint research opportunities, information exchanges, and career assistance. This study might offer academics a fresh theoretical viewpoint that improves the conceptual frameworks for mindfulness practice for enhancing academic social capital via intercultural communication

    Feasibility of mango by-products and biogas solid residue aerobic co-composting at different C/N ratios

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    Purpose: Co-composting of mango by-products and biogas solid residue eliminates some shortcomings of composting these wastes separately. Specifically, co-composing solves the problem of the low pH values in mango by-products while enhances biodegradable organic matter of biogas solid residues. However, no research report is available on co-composting of mango by-products (MB) and biogas solid residue (BR). Method: This study established three in-vessel lab-scale composting bins with 3 different C/N ratios, including Bin 1: 27.4/1 (156 kg MB + 144 kg BR); Bin 2: 30.23/1 (193 kg MB + 107 kg BR); and Bin 3: 37.7/1 (224 kg MB + 76 kg BR). The raw compost materials underwent 57 days of incubation, including 36 days of raw incubation and 21 days of mineralization. Results: Bin 3 containing larger amounts of mango by-products and less amounts of biogas residue showed a higher percentage of remaining carbon in the final products (17.97%), lower nitrogen loss (17%), and showed 0.5% increase in available P2O5 content, compared to the other bins. From 300 kg of initial raw material, the final compost mass in Bin 1, Bin 2, and Bin 3 were 26.2 kg, 32.7 kg, and 88.1 kg, respectively. Conclusion: Resultantly, an initial C/N ratio of 37.7/1 could be suggested in the aerobic co-composting of biogas residue with mango by-products. Research Highlights ·       Co-composting of mango by-products and biogas solid residue eliminates some of the weaknesses of composting these wastes separately. ·       The incubation period determined was 57 days of incubation, including 36 days of raw incubation and 21 days of mineralization. ·       Among three C/N ratios surveyed, the highest C/N in bin 3 (C/N=37.7/1) showed the best-favoured condition for mango by-products treatment and generate the highest amount of compost product. ·       Bin 3 showed the highest percentage of remaining carbon in compost products (17.97%), a lower in nitrogen loss (17%), and 0.5% increase in available P2O5 content

    Piezoelectric catalysis for efficient reduction of CO<sub>2</sub> using lead-free ferroelectric particulates

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    The increase in global energy demand, together with a rise in carbon dioxide (CO2) levels have encouraged research into the reduction of CO2 into useful chemicals and fuels. In this paper, we demonstrate the piezo-catalytic reduction of CO2 using lead-free lithium-doped potassium sodium niobate (KNN) ferroelectric ceramic particulates. The application of acoustic waves generated by ultrasound to a suspension of the ceramics particles creates pressure waves result in a large change in the spontaneous polarisation of the KNN particles via the piezoelectric effect, which in turn creates surfaces charges for CO2 reduction. The effect of CO2 gas concentration, the presence of dissolved species, and catalyst loading on piezo-catalytic performance are explored. By optimization of the piezo-catalytic effect, a promising piezo-catalytic CO2 reduction rate of 438 ÎŒmol g−1 h−1 is achieved, which is much larger than the those obtained from pyro-catalytic effects. This efficient and polarisation tuneable piezo-catalytic route has potential to promote the development of CO2 reduction via the utilisation of vibrational energy for environmental benefit.</p

    Teaching practicum: The impacts on classroom management skills of novice lecturers

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    This research investigates the perspectives of the novice lecturers in the Faculty of English Language Teacher Education (FELTE) regarding Teaching Practicum’s impacts on their classroom management skills. Using survey research, data was gathered through questionnaires distributed among the whole population of 29 participants, followed by semi-structured interviews to gain a deeper insight into participants’ experience. The study’s results showed that novice lecturers generally made considerable progress in classroom management skills, especially in attention-drawing and response encouragement, creation of a motivating environment as well as physical and emotional interactions with students. On the other hand, it was discovered that inadequate duration and inappropriate timing generally impeded novice lecturers’ gains during their Teaching Practicum. However, some challenges related to supervisor and school choice turned out to be significant factors from which participants could derive considerable benefits, which is opposed to previous research. At the end of the study, some recommendations were suggested for future research on this topic

    Efficient methane dry reforming process with low nickel loading for greenhouse gas mitigation

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    In this study, a series of nickels supported on gamma alumina with a metal dosage ranging from 0.5 to 3 wt.% were prepared and employed as the catalysts. The effect of nickel dosage on material properties, reaction performance, and catalyst deactivation was investigated. At a low dosage, the nickel-free having low metal-support interaction contributed significantly to the total active site. The basicity of the material was enhanced along with the increase in nickel loading. The presence of active metal showed a great impact at the beginning leading to big improvements in feedstock conversion. However, beyond a nickel dosage of 2 wt.%, further additions did not noticeably influence the reaction performance. Regarding catalyst deactivation, different carbon species were observed on catalyst surface, depending on the nickel dosage. Catalysts with less than 2 wt.% nickel exhibited amorphous carbon as the dominant morphology on the spent catalyst. In contrast, catalysts with 2Ni/Al2O3 and 3Ni/Al2O3 compositions showed graphitic carbon as the main side product. These findings provide insights into the relationship between nickel dosage, catalyst properties, and catalytic performance in methane dry reforming. By understanding the effects of nickel loading on material properties and reaction behavior, researchers can optimize catalyst design and develop more efficient and stable catalysts for sustainable syngas production

    Characterization of Ag-Doped p-Type SnO Thin Films Prepared by DC Magnetron Sputtering

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    Crystalline structure and optoelectrical properties of silver-doped tin monoxide thin films with different dopant concentrations prepared by DC magnetron sputtering are investigated. The X-ray diffraction patterns reveal that the tetragonal SnO phase exhibits preferred orientations along (101) and (110) planes. Our results indicate that replacing Sn2+ in the SnO lattice with Ag+ ions produces smaller-sized crystallites, which may lead to enhanced carrier scattering at grain boundaries. This causes a deterioration in the carrier mobility, even though the carrier concentration improves by two orders of magnitude due to doping. In addition, the Ag-doped SnO thin films show a p-type semiconductor behavior, with a direct optical gap and decreasing transmittance with increasing Ag dopant concentration

    Carbon dioxide reforming of methane over modified iron-cobalt alumina catalyst : Role of promoter

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    Cobalt-based catalysts are widely employed in methane dry reforming but tend to deactivate quickly due to coke deposits and metal sintering. To enhance the performance, iron, a cost-effective promoter, is added, improving cobalt's metal dispersibility, reducibility, and basicity on the support. This addition accelerates carbon gasification, effectively inhibiting coke deposition. Methods: A series of iron-doped cobalt alumina MFe-5Co/Al2O3 (M= 0, 0.4, 0.8, 1, 2 wt.%) were prepared via simple incipient-wetness impregnation. The catalysts were thoroughly characterized via modern techniques including BET, XRD, H2-TPR, CO2-TPD. Significant findings: The addition of iron had a minimal impact on the properties of Îł-Al2O3, but it significantly affected the dispersibility of cobalt. At an optimal dosage of 0.8 wt.%, there was a notable decrease of 29.44% in Co3O4 particle size. However, excessive iron loading induced agglomeration of Co3O4, which was reversible. The presence of iron also resulted in a decrease in the reduction temperature of Co3O4. The material's basicity was primarily influenced by the loading of iron, reaching its highest value of 705.7 ÎŒmol CO2 g−1 in the 2Fe-5Co/Al2O3. The correlation between catalytic activity and the physicochemical properties of the material was established. The 0.8Fe-5Co/Al2O3 sample exhibited excellent performance due to the favorable dispersibility of cobalt, its reducibility, and its affordable basicity
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