Vietnam Journal of Science and Technology
ACI
2815-5874
Cơ quản chủ quản: N/A
Lĩnh vực:
Các bài báo tiêu biểu
Finite element modelling for free vibration response of cracked stiffened FGM plates
Tập 58 Số 1 - Trang 119-129 - 2020
This paper presents the new numerical results of vibration response analysis of cracked FGM plate based on phase-field theory and finite element method. Effects of geometrical and material properties on the vibration behaviors of the plate are investigated in this work. The computed results show that the crack and stiffener have a strong influence on both the vibration responses and vibration mode......
#finite element #phase-field theory #FGM #crack #stiffened plates #vibration
EFFECT OF NANOSILICA FROM RICE HUSK ON THE GROWTH ENHANCEMENT OF CHILI PLANT (Capsicum frutescens L.)
Tập 54 Số 5 - Trang 607 - 2023
Nanomaterials hold great promise of improved plant disease resistance, controlled release of agro-chemicals, enhanced plant growth, etc. In this study, the effect of nanosilica (10 – 30 nm) prepared from rice husk on the growth promotion of chili plant in green house was carried out. The experiment of nanosilica treatment by foliar spraying was arranged in a factorial design with 3 replications at......
#Nanosilica #rice husk #growth #chili plant
Membrane distillation for seawater desalination applications in Vietnam: potential and challenges
Tập 55 Số 6 - Trang 659-682 - 2017
Desalination of seawater using membrane distillation (MD) can be a practical approach to mitigating the fresh water scarcity in Vietnam. This paper provides a comprehensive review of the seawater MD desalination process. The fundamentals of the MD process including configurations, membrane modules, membrane properties, and heat and mass transfer mechanisms together with approaches to enhancing hea......
#membrane distillation #seawater desalination #fresh water scarcity #desalination processes
Analytical solutions for bending, buckling and vibration analysis of functionally graded cylindrical panel
Tập 55 Số 5 - Trang 587-597 - 2017
The main purpose of this article is to present analytical solutions for bending, buckling and vibration analysis of cylindrical panel, which are composed of functionally graded materials (FGMs). Equations of motion are derived using Hamilton’s principle. The first-order shear deformation theory is used for developing Navier’s solutions of simply supported cylindrical panel. Comparison studies are ......
#functionally graded cylindrical shell #shear deformation theory #bending #buckling #vibration
Phenolic compounds from Callistemon citrinus leaves and stems
Tập 54 Số 2 - Trang 190-197 - 2016
In the search for bioactive constituents from Vietnamese plants, the leaves and stems of Callistemon citrinus (Curtis) Skeels were selected for chemical investigation. Phytochemical analysis of plant led to the isolation of eight phenolic compounds including two flavonoids (eucalyptine (1) and 8-demethyleucalyptine (2)), two alcohols (blumenol A (3), n-tetratriacontanol (4)), three benzoic acid d......
#Callistemon citrinus #flavonoid #triterpenoid.
Chemical and pharmacological evaluation of Manglicolous lichen Graphis ajarekarii PATW. & C. R. KULK.
Tập 57 Số 3 - Trang 300-308 - 2019
The chemical examination of ethanolic extract of manglicolous lichen Graphis ajarekarii (Ga-Et) resulted in isolation of three known metabolites – chiodectonic acid (1), graphenone (2) and graphisquinone (3). All the isolates (1-3) and Ga-Et were screened against DPPH and superoxide free radicals, six different cancer cell lines and one normal human cell line (NHME). This work is the first report ......
#manglicolous lichen #antioxidant #cancer #Sulforhodamine B assay
Biodiversity and distribution patterns of free-living nematodes communities in Ba Lai river, Ben Tre province
Tập 56 Số 2 - Trang 224-235 - 2018
Nematodes communities in Ba Lai river, Ben Tre province were investigated in September of 2015 (eight stations from estuary to upstream). The results showed that the nematodes communities have characterized by high density and biodiversity, providing useful information of nematodes assemblages in freshwater habitas, in particular inland river. Also the results indicated that the distribution of ne......
#Ba Lai dam #Ben Tre province #biodiversity #dam effect #distribution #nematodes communities
Chemical constituents from methanolic extract of Garcinia mackeaniana leaves and their antioxidant activity
Tập 58 Số 4 - Trang 411-418 - 2020
A phytochemical investigation of the methanolic extract of Garcinia mackeaniana leaves led to the isolation, and determination of five secondary metabolites, including one benzophenone 4,3',4'-trihydroxy-2,6-dimethoxybenzophenone (1), two flavone C-glucosides vitexin (2) and its 2''-O-acetyl derivative (3), one biflavone amentoflavone (4), and one mono-phenol methyl protocatechuate (5). The chemic......
#Garcinia mackeaniana #leaves #phytochemistry #antioxidant activity
Flavonoids isolated from the flowers of Camellia chrysantha
Tập 57 Số 3 - Trang 287-293 - 2019
Camellia chrysantha (the golden camellia, golden tea) is a species of evergreen shrub or small tree belonging to the family Theaceae. The flowers and the leaves of this plant are used as tea and drank for its health benefits. The aim of this study was to investigate the chemical constituents of the flowers of Camellia chrysantha. Five flavonoids were isolated from the flowers of Camellia chrysanth......
#Camellia chrysantha #Theaceae #catechin #epicatechin #quercetin #quercetin-3-O-methyl ether #kaempferol.
Application of fuzzy logic for controlling mechanism of relative manipulation robot (MRM robot)
Tập 54 Số 3 - Trang 385-401 - 2016
In robot control, mathematical equations describing dynamic behaviors of robots are usually complicated. Additionally, the components such as inertial and friction parameters appearing in these equations are very difficult to determine exactly. With robots having complex structure such as parallel robots, MRM robots etc., the derivation of dynamic equations becomes more difficult and sometimes can......
#mechanism of relative manipulation robot (MRM robot) #fuzzy logic #fuzzy control