128 research outputs found

    A see-saw scenario of an A4A_4 flavour symmetric standard model

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    A see-saw scenario for an A4A_4 flavour symmetric standard model is presented. The latter, compared with the standard model, has an extended field content adopting now an additional A4A_4 symmetry structure (along with the standard model symmetry). As before, the see-saw mechanism can be realized in several models of different types depending on different ways of neutrino mass generation corresponding to the introduction of new (heavy in general) fields with different symmetry structures. In the present paper, a general description of all these see-saw types is made with a more detailed investigation on type-I models, while for type-II and type-III models a similar strategy can be followed. As within the original see-saw mechanism, the symmetry structure of the standard model fields decides the number and the symmetry structure of the new fields. In a model considered here, the scalar sector consists of three standard-model-Higgs-like iso-doublets (SUL(2)SU_L(2)-doublets) forming together an A4A_4-triplet, and three iso-singlets transforming as three singlets (1,1′1^{'} and 1′′1^{''}) of A4A_4. In the lepton sector, the three left-handed lepton iso-doublets form an A4A_4-triplet, while the three right-handed charged leptons are either A4A_4-singlets in one version of the model, or components of an A4A_4-triplet in another version. To generate neutrino masses through, say, the type-I see-saw mechanism, it is natural to add four right-handed neutrino multiplets, including one A4A_4-triplet and three A4A_4-singlets. For an interpretation, the model is applied to deriving some physics quantities such as neutrinoless double beta decay effective mass ∣⟨mee⟩∣|\langle m_{ee}\rangle|, CP violation phase δCP\delta_{CP} and Jarlskog parameter JCPJ_{CP}, which can be verified experimentally.Comment: LaTeX, 31 pages, 12 figures, 6 tables. V3: some parts modifie

    Model of neutrino effective masses

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    It is shown that an effective (nonrenormalizable) coupling of lepton multiplets to scalar triplets in the 331 model with sterile/exotic neutrinos, can be a good way for generating neutrino masses of different types. The method is simple and avoids radiative/loop calculations which, sometimes, are long and complicated. Basing on some astrophysical arguments it is also stated that the scale of SU(3)L symmetry breaking is at TeV scale, in agreement with earlier investigations. Or equivalently, starting from this symmetry breaking scale we could have sterile/exotic neutrinos with mass of a few keV's which could be used to explain several astrophysical and cosmological puzzles, such as the dark matter, the fast motion of the observed pulsars, the re-ionization of the Universe, etc

    Challenges And Opportunities For The Development Of Infrastructure After ‘Oda Graduation’ - Moving Towards Sustainable Development: Case Study Of Vietnam

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    The research on ODA will be focused on its relation to Goal 17, the Partnership, considered a major issue by the researchers, especially in the case of Vietnam as a developing economy. ODA was mainly used for investing in economic infrastructure when Vietnam witnessed a downfall in receiving financial aid due to its significant economic growth. ODA helped Vietnam transform from one of the world’s poorest nations into a lower middle-income country and soon, this is going to lead to the ‘ODA Graduation’. However, the process has just begun. The country is still in a process of industrialization and modernization and its socio-economic situation has not been stable or solid. By all means, ODA is not only a financial resource, it also helps the country to accomplish Sustainable Development Goals (SDGs) of the UN. ‘ODA Graduation’ means that the economy of Vietnam has faced certain challenges such as increasing pressure of outbound debts; raising impact on social development or imbalance between high capital recovery investments and public-services investments. However, ‘ODA Graduation’ has brought certain opportunities such as increasing Vietnam’s independence in capital mobilization, preventing the removal of tariffs barrier, reducing losses and waste of funds. This research gives recommendations for improving Vietnam’s economic situation and can help overcome the difficulties in the period of ‘ODA Graduation’

    Challenges And Opportunities For The Development Of Infrastructure After ‘Oda Graduation’ - Moving Towards Sustainable Development: Case Study Of Vietnam

    Get PDF
    The research on ODA will be focused on its relation to Goal 17, the Partnership, considered a major issue by the researchers, especially in the case of Vietnam as a developing economy. ODA was mainly used for investing in economic infrastructure when Vietnam witnessed a downfall in receiving financial aid due to its significant economic growth. ODA helped Vietnam transform from one of the world’s poorest nations into a lower middle-income country and soon, this is going to lead to the ‘ODA Graduation’. However, the process has just begun. The country is still in a process of industrialization and modernization and its socio-economic situation has not been stable or solid. By all means, ODA is not only a financial resource, it also helps the country to accomplish Sustainable Development Goals (SDGs) of the UN. ‘ODA Graduation’ means that the economy of Vietnam has faced certain challenges such as increasing pressure of outbound debts; raising impact on social development or imbalance between high capital recovery investments and public-services investments. However, ‘ODA Graduation’ has brought certain opportunities such as increasing Vietnam’s independence in capital mobilization, preventing the removal of tariffs barrier, reducing losses and waste of funds. This research gives recommendations for improving Vietnam’s economic situation and can help overcome the difficulties in the period of ‘ODA Graduation’

    The Impact of TikTok UGC Videos on Online Purchase Intention: Mediating Role of Cognitive States

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    Background: User-Generated Content (UGC) videos have received considerable attention in recent years thanks to their great potential for buyers and sellers. However, the effect of this content on consumer behavior remains unclear, especially in the context of developing countries (e.g., Vietnam). By applying the Stimulus-Organism-Response model (S-O-R model), this paper examines the effect of UGC videos on online purchase intention. Moreover, the mediating role of cognitive responses, consisting of perceived credibility, perceived diagnosticity, and mental imagery, is also examined to offer valuable insights to businesses, enabling them to leverage and effectively promote the trends of UGC videos. Method: A convenience sampling method was employed to collect the data. A total of 318 valid respondents participated in this survey. The data was analyzed with the Partial Least Squares Structural Equation Modeling method (PLS-SEM). Results: The findings show that UGC videos have a direct impact on online purchase intention. This paper also verified that cognitive states mediate the relationship between stimuli and subsequent behavioral intentions. Conclusion: Our research findings enrich the literature on consumer’s online purchase intentions by applying the S-O-R framework by highlighting the role of cognitive responses, and improving generalizability by contributing additional consumer behavior findings in developing Asian nations. Moreover, this paper offers businesses insights into the formation of customers\u27 purchase intentions while watching UGC videos. Based on that, this paper raises practical recommendations regarding promoting the UGC video trend and creating UGC videos effectively to improve the cognitive states perceived by customers, including credibility, diagnostic value, and mental imagery

    AGING OF WATERBORNE PAINT BASED ON THE ACRYLIC RESIN EMULSION AND ORGANIC PIGMENT

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    Aging of waterborne paint on the base of acrylic resin emulsion with and without green Luconyl have been investigated by general appearance assessment, adhesion change, FT-IR and discoloration. The obtained results showed that the both of paint-formulas coatings had no cracks, blisters, flacks and there was no change of adhesion during the aging process. However, IR analysis indicated that there were some changes in chemical structures of coating with and without Green Luconyl during aging process. To specify, IR spectrums of initial and aged coating no containing Green Luconyl illustrated aging process led content of O-H and C=C increased significantly but baseline of spectra was fairly unchanged. For coating filled Green Luconyl, IR spectrums’ shape was fairly stable but baseline saw a clear reduce during accelerated weather exposure. Moreover, SEM images indicated that surfaces morphology of samples changed differently depending on in presence of organic pigment. Surface of aged coating without Luconyl saw rougher than surface of coating with Luconyl after aging process. Hence, the weather aging test had more significant influence on paint coating in absence of Luconyl than paint coating in presence of Luconyl. It was explained that the macroradical produced in aging process would attack into conjugated double bonds of Luconyl instead of double bonds of AC-261 leading to aged coating filled Luconyl become more opaque than initial while coating no filled Luconyl had significant changes in chemical structure during aging process. Although this was a hypothesis, it saw a suitable with the obtained results. The paint coating in presence of Luconyl illustrated significant color change, especially, showed the loss of green color while the other paint coating showed slight color change

    An Aquaculture Water Checker--design and Manufacture

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    A real-time, mobile aquaculture water checker is presented. The configuration of double integrating spheres is developed for simultaneously measuring backward scattering RdR_d, forward scattering TdT_d  and transmitted light TcT_c . Based on Kubelka-Munk model, a set of optical parameters including absorption coefficient μa\mu _a , scattering coefficient μs\mu_s and anisotropy  gg  are calculated. The obtained results for diluted milk standard samples with different milk concentrations and aquaculture water samples with different densities of Psexdo-Nitzschia-delicatissium algae are also reported

    OXIDIZED MAIZE STARCH: CHARACTERIZATION AND EFFECT OF IT ON THE BIODEGRADABLE FILMS I. CHARACTERIZATION OF MAIZE STARCH OXIDIZED BY SODIUM HYPOCHLORITE

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    The effects of hypochlorite level, i.e. 0.5; 1 and 2 active chlorine g/100g starch, on the structures and physicochemical properties of oxidized maize starch were investigated. The obtained results shown that oxidation degree grew up with increasing hypochlorite concentration, specially, the carboxyl content saw higher increased than the content of carbonyl. SEM images indicated that surface of oxidized maize starches were rougher than native starch. The surface of oxidized starches saw rougher with increasing hypochlorite level. However, the DSC results illustrated that there was no significant difference of gelatinization temperature between the native starch and oxidized starches

    Effect of Silica Nanoparticles on Properties of Coatings Based on Acrylic Emulsion Resin

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    Effect of nanosilica size on physic-mechanical properties, thermal stability and weathering durability of coating based on acrylic emulsion. Nanocomposite coating formulas were filled by 2 wt.% nanosilica particles which were used in this study, namely: nanosilica from Sigma (15-20nm), nansilica from rice husk (~70-200 nm) and nanosilica from Arosil – Belgium (7-12 nm). Obtained results showed that viscosity flow of coating formula containing nanosilica from Arosil saw the highest flow-time while coating formulas filled other nanosilica and unfilled nanosilica experienced similar flow-time. In presence of nanosilica, coating properties were improved in comparison with neat coating. However, coating filled by nanosilica from rice husk indicated the best properties in studied coating formula. It may explained that size of nanosilica from rice husk was the largest in studied nanosilica particles and thus easily dispersing into coating formula

    HMU fluorinze mouthwash enhances enamel remineralization: An in vitro study

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    BACKGROUND: Fluoride therapy has long been used extensively to prevent dental caries. Fluoride appears in variety of dental care products such as mouthrinse, dentifrice, gel, etc. HMU fluorinze is the first mouthwash containing fluoride in Vietnam. AIM: This research was conducted to evaluate the efficacy of HMU Fluorinze mouthwash on remineralizing enamel in laboratory conditions. METHODS: 20 third molars teeth were cleaned and covered with nail polish , except for a 3x3 mm square on their buccal surfaces. These teeth went through two steps: demineralization using Coke and remineralization for 20 days: 1) using standard calcifying solution (control group) and 2) using standard calcifying solution + HMU Fluorinze mouthwash 2 times/day (experimental group). The mineralization index of enamel structure after demineralization and remineralization was assessed by DIAGNOdent pen 2190. RESULTS: The mineralization indexes of the control group and experimental group at baseline were 3.65 ± 0.76 and 3.35 ± 0.64, after demineralization were in turn of 21.78 ± 4.48 and 20.25 ± 2.26; and after remineralization were 6.30 ± 1.03 and 3.90 ± 1.24. The different figures  between the two groups after remineralization shows statistical significance (p<0.01). Group B using HMU fluorinze mouthwash after 20 days did not differ from the original results (p = 0.272), in contrast with the control group (p<0.01). CONCLUSIONS: HMU fluorinze mouthwash has better mineralization effect than standard calcifying solution
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