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This paper deals with the dynamic response of Functionally Graded Material (FGM) plates resting on a viscoelastic foundation under dynamic loads. The governing equations are derived by using Hamilton’s principle using the classical plate theory and the higher-order shear deformation plate theory. Using state-space methods to find the closed-form solution of the dynamic response of functionally graded rectangular plates resting on a viscoelastic foundation. Numerical examples are given for displacement and stresses in the plates with various structural parameters and the effects of these parameters are discussed. The result of the numerical example shows a marked decrease in displacement and stresses as the coefficient of viscous damping is increased.

Tea leaves (Camellia sinensis) have many health benefits due to their abundance of polyphenols with antioxidant activity, most notably epigallocatechin‐3‐gallate (EGCG). To protect those bioactive compounds, the spray‐drying technique of green tea‐extracted solution is conducted because of encapsulating. This study aimed to optimize the spray‐drying condition using the response surface methodology (RSM) with respect to the maximal polyphenol content of the product. Furthermore, the characterizations of resulting powder were determined. The results showed that optimal spray‐drying temperature, input flow rate, and whey protein isolate (WPI) content were evaluated at 136℃, 6.8 rpm, and 10.3% of dry basis, respectively. The obtained green tea powder products, which got from optimal spray‐drying process, achieved total polyphenol content (TPC), EGCG, and caffeine content of 322.06 mg GAE/g, 11.4%, and 2.8% of dry basis, respectively. This result revealed the feasibility of green tea leaves to produce tea powder rich in EGCG and polyphenols by spray‐drying technique, potentially contributing to the diversification of tea products., The spray‐drying process to make tea powder from the extract was optimized by RSM with response of total polyphenol. The tea powder product shows attractive characterization of remained total polyphenol, chlorophyll, EGCG, and caffeine.

Plus tree selection is the first step to improve production and quality in forestry. An individual-based method is widely used to select plus trees for timber production, timber form, freedom from diseases and insects. In this study, a method to select plus trees for flower production is described and named as a crown-area-based method. Both individual-based and crown-area-based methods were used to select plus trees for Camellia impressinervis, a golden camellia; its yellow flowers have been used to treat sore throat and diarrhea, and to prevent cancers in China and Vietnam. Flower production of 21 concerned individuals was compared to the population mean and it was generated as a percentage. The population mean of the individual-based method is the mean of production of 21 trees as mean production/tree. While population mean of the crown-area-based method is mean production/m2 crown area (first production/m2 crown area for each tree was generated, then mean for population). The results indicated that both methods show seven individual trees with flower production >100% population mean. However, individual trees are different. Only five of 7 trees are the same in both methods. The tree rankings by flower production percentage in both methods are totally different. The highest ranking by individual-based method (310% mean) is 4th ranking by crown-area-based method (181% mean). While the highest ranking by crown-area-based method (270% mean) is third ranking by individual-based method (260% mean). It is concluded that crown-area-based method is better in selecting plus trees for flower purpose, as it considers the crown area which is known as a productive part of a tree to form flowers.

Biotic and abiotic factors control aboveground biomass (AGB) and the structure of forest ecosystems. This study analyses the variation of AGB and stand structure of evergreen broadleaved forests among six ecoregions of Vietnam. A data set of 173 1-ha plots from 52 locations in undisturbed old-growth forests was developed. The results indicate that basal area and AGB are closely correlated with annual precipitation, but not with annual temperature, evaporation or hours of sunshine. Basal area and AGB are positively correlated with trees > 30 cm DBH. Most areas surveyed (52.6%) in these old-growth forests had AGB of 100–200 Mg ha−1; 5.2% had AGB of 400–500 Mg ha−1, and 0.6% had AGB of > 800 Mg ha−1. Seventy percent of the areas surveyed had stand densities of 300–600 ind. ha−1, and 64% had basal areas of 20–40 m2 ha−1. Precipitation is an important factor influencing the AGB of old-growth, evergreen broadleaved forests in Vietnam. Disturbances causing the loss of large-diameter trees (e.g., > 100 cm DBH) affects AGB but may not seriously affect stand density.

Standardized surveillance for health care-associated infections (HAI) is critical to understand HAI burden and inform prevention strategies at a national level. Due to differing and generally limited resources in Vietnam's health care facilities, implementation of HAI surveillance has been variable and data quality has not been systematically assessed. In 2016, the Vietnam Administration for Medical Services (VAMS) under the Ministry of Health, with the support of partners, began to establish a context-appropriate, standardized HAI surveillance system for bloodstream infections (BSI) and urinary tract infections (UTI) among 6 pilot hospitals in Vietnam. We identified 5 key elements of our HAI surveillance implementation process that have been conducive to ensuring data quality and program sustainability and scalability. These include: (1) engaging stakeholders, (2) designating roles and responsibilities, (3) developing context-sensitive, standardized surveillance protocols, (4) creating a surveillance implementation strategy, and (5) linking HAI surveillance and prevention activities. With the active participation of infection prevention and control staff from the 6 pilot hospitals, standardized HAI surveillance for BSIs and UTIs was expanded to 12 additional hospitals in 2019. Together, VAMS and partners are helping Vietnam fulfill its commitment to safe health care for all patients.

Soybean is one of the essential ingredients when formulating a tube feeding formula. In this study, we initially focused on determining which enzyme is suitable for hydrolyzing soy and comparing the soy protein enzymatic hydrolysis of three different enzymes at the same enzyme content: Flavourzyme, Protamex, and Alcalase. The result showed that Flavourzyme attained the highest soluble protein recovery efficiency (SPRE). Secondly, the study determined the effect of thermal treatment conditions such as thermal treatment duration, and then it showed that when combining the thermal treatment and enzymatic hydrolysis, the yield reached (61.44 &plusmn, 0.22)%, which was much higher than only using enzymatic hydrolysis (52.57 &plusmn, 0.27)%. Next, optimizing the enzymatic hydrolysis (combining thermal treatment) using Flavourzyme and Alcalase, Flavourzyme achieved (62.47 &plusmn, 0.12)%, while Alcalase attained (41.32 &plusmn, 0.13)%. The soy hydrolyzate using Flavourzyme achieved an average molecular size of 3.19 kDa at the following optimizing conditions: enzyme concentration, 16.09 U&middot, g&minus, 1, pH, 7.02, temperature, 45.8 &deg, C, and beans/water ratio, 1:3. In contrast, when using Alcalase, the soy hydrolyzate achieved an average molecular size of 1.52 kDa at the following optimizing conditions: enzyme concentration, 28.01 U&middot, pH, 7.2, temperature, 56.5 &deg, beans/water ratio, 1:4.6. Soy protein hydrolyzate of suitable viscosity and particle size flow through the inhaler with branched-chain amino acids achieved a BCAA (Branched Amino Acid) ratio of 2:1:1 for Alcalase and 4:1:1 for Flavourzyme. Soybean hydrolyzate using both enzymes attained a high SPRE and was suitable for the digestive ability of patients recovering from surgery. Soy protein is divided into amino acids, di- and tri-amino acids, and peptides to create a soluble protein source that helps feed patients with a sonde tube easily. In addition, the molecular weight of peptides will reduce viscosity significantly when passing through a sonde tube, preventing tube congestion.

NaYF4:(Yb,Tm) upconversion materials were synthesized by the simple hydrothermal method. Growth duration was varied from 4h to 12h under a growth temperature of 150oC. The structural, optical and surface morphology characteristics of the NaYF4:(Yb,Tm) UC materials were investigated. The XRD and SEM results illustrated that the NaYF4:(Yb,Tm) materials were transformed from the multiple phases (hexagonal and cubic) to the single-phase (hexagonal prism) as growth duration being longer than 8h with the average diameter and length of these prisms being about 0.5 µm and 2 µm, respectively. Under 980 nm laser excitation, the NaYF4:(Yb,Tm) emits at peaks of 450 nm (1D2→ 3F4), 475 nm (1G4→3H6), 647 nm (1G4→3F4) and 697 nm (3F3→3H6), with the highest emission belonging to NaYF4:(Yb,Tm) grown for 8h. Keywords: NaYF4:(Yb,Tm), upconversion materials, photoluminescence, growth duration, hydrothermal method. References [1] L. Wang, R. Yan, Z. Huo, L. 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