Trade facilitation performance influences on ASEAN trade flows

The Association of Southeast Asian Nations (ASEAN) considers trade facilitation as a driving force in forming a single market and a single production base. This paper constructs an ASEAN scorecard for measuring the performance of trade facilitation strategic plans by ASEAN member states. Next, a structural gravity model is used in the paper in order to estimate the trade facilitation performance influence on ASEAN trade flows. The fact that the indicator of easing Nontariff Barriers (NTBs) and institutional coordination, on the one hand, and the ASEAN member states’ engagement indicator, on the other, had the highest enforcement scores in ASEAN in the period 2017-2019. Those two indicators also exert the biggest influence on ASEAN trade flows, especially ASEAN extra-regional trade

Using fly ash treated by NaOH and H2SO4 solutions for Hg2+ and Cd2+ ion adsorption.

This paper presents the results of adsorption ability of heavy metal ions (Hg2+ and Cd2+) by fly ash (FA) before and after treatment using NaOH and H2SO4 solutions.  Original- and treated FA were characterized by Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), and Scanning Electron Microscope (SEM). Specific surface area of FA before and after treatment was calculated by Brunauer – Emmett – Teller (BET) isotherm equation. The obtained results indicated that the morphology and specific surface area of FA changed clearly after treatment by acid or alkaline solutions. Adsorption capacity the Hg2+ and Cd2+ ion by FA was determined from data of UV-Vis spectra. After treatment, the adsorption capacity of ions by FA increased remarkably in comparison with non-treated FA. The FA treated by NaOH solution has the adsorption capacity higher than FA treated by H2SO4 solution. The maximum adsorption capacity of the FA treated by NaOH solution for Cd2+ and Hg2+ ions at room temperature is 28.97 and 14.60 mg/g, respectively. The equilibrium adsorption data were described by the Langmuir and Freundlich isotherm models. The results showed that equilibrium data were fitted well to the Langmuir isotherm. Keywords. Fly ash, treatment, adsorption capacity, heavy metal, Langmuir isotherm

Osteogenesis activity of fractions extracted from Clinacanthus nutans (Burm. F.) Lindau

Osteogenesis activity of fractions extracted from Clinacanthus nutans was evaluated on an in vitro model using osteoblast MC3T3-E1 cells. The results showed that all fractions, including ethanol (EtOH), n-hexane, ethyl acetate (EtOAc) and butanol (BuOH) were not significantly toxic to the osteoblast cells at the test concentrations of 5, 10, 25, and 50 µg/mL. The EtOH and EtOAc fractions exhibited the highest osteogenesis activity in terms of enhancement of alkaline phosphatase (ALP) and mineralization activity of MC3T3-E1 cells, especially the EtOAc fraction which increased ALP activity up to 30% and mineralization activity up to 100%. Thus, the EtOAc fraction shows osteogenesis activity through stimulating activites of the two markers for bone generation including ALP and mineralization in osteoblast cells. The fraction is now under extensive investigation to isolate and fully understand the modes of action of the active compounds. 

Preparation and characterization of magnesium hydroxyapatite coatings on 316L stainless steel

Magnesium hydroxyapatite coatings (MgHAp) were deposited on the surface of 316L stainless steel (316L SS) substrates by electrodeposition technique. Different concentrations of Mg2+ ion were incorporated into the apatite structure by adding Mg(NO3)2 into electrolyte solution containing 3×10-2 M Ca(NO3)2, 1.8×10-2 M NH4H2PO4 and   6×10-2 M NaNO3. With Mg2+ concentration 1×10-3 M, the obtained coatings have 0.2 wt% Mg2+. The influences of scanning potential ranges, scanning times to deposit MgHAp coatings were researched. The analytical results FTIR, SEM, X-ray, EDX, thickness and adhension strength showed that MgHAp coatings were single phase of HAp, fibrous shapes, thickness 8.1 µm and adhesion strength 7.20 MPa at the scanning potential ranges of 0÷-1.7 V/SCE and scanning times of 5 scans. Keywords. 316L SS, Electrodeposition, MgHAp

ELECTRODEPOSITION OF CO-DOPED HYDROXYAPATITE COATING ON 316L STAINLESS STEEL

Hydroxyapatite (HAp) co-doped by magnesium (Mg), strontium (Sr), sodium (Na) and fluorine (F) were deposited on the 316L stainless steel (316L SS) substrate by electrodeposition method. The influences of scanning potential ranges, scanning times, scanning rates to form MgSrFNaHAp coating were investigated. The analytical results FTIR, SEM, Xray, EDX, thickness and adhension of the obtained coating at scanning potential ranges of 0 ÷ -1.7 V/SCE; scaning times of 5, scanning rate of 5 mV/s showed that MgSrFNaHAp coatings were single phase crystals of HAp, rod shape with the thickness 8.9 µm and the adhesion strength reached 8.38 MPa

Electrodeposition of HAp coatings on Ti6Al4V alloy and its electrochemical behavior in simulated body fluid solution

Hydroxyapatite (HAp) coatings were prepared on Ti6Al4V substrate by electrodeposition method from electrolyte solution containing Ca(NO3)2, NH4H2PO4 and NaNO3. The results show that the HAp coatings were single phase crystals of HAp. Scanning electron microscope (SEM) images present that HAp/Ti6Al4V have flake shapes which arrange to form like-coral agglomerates. In vitro test of the Ti6Al4V and HAp/Ti6Al4V in simulated body fluid (SBF) solution was investigated with different immersion times. pH of SBF solution decreased and the mass of materials increased. SEM images prove the formation of apatite on the surface of Ti6Al4V and HAp/Ti6Al4V. The corrosion current density during immersion time of substrate is always higher than the one of HAp/Ti6Al4V because the deposited HAp can protect well for the substrate

Optimization of culture conditions of Streptomyces antibioticus strain 1083 to improve the antimicrobial activity against Aeromonas hydrophila

Fish is a healthy, high protein and low fat food that encourages the health and growth of people, especially children. However, in fact fish is very sensitive to many diseases which affects the productivity and quality of fish. Therefore, identifying the cause of the diseases and finding preventive measures become an urgent task today. In the previous study, we isolated Streptomyces antibioticus strain 1083 that has the ability to antagonize Aeromonas hydrophila - a pathogenic bacterium in fish. Based on the obtained results, we continue to perform this study to determine optimal conditions for the culture of S. antibioticus strain 1083 in order to produce antimicrobial compounds against A. hydrophila. The production of antagonists by the strain 1083 was optimized by controlling the condition of different inoculations such as media, pH, temperature and incubation period. The results indicated that International Streptomyces Project 2 (ISP2) was the best medium for S. antibioticus strain 1083 to produce the highest antimicrobial activity against A. hydrophila with 32 mm in diameter of inhibited zone. The actinomycete strain 1083 could express the maximum antimicrobial activity when they were incubated in shaker incubator (200rpm) at 40oC with pH8 in 8 days. The ability of the actinomycete strain in antagonism against A. hydrophila was evaluated by adding different culture medium volume of S. antibioticus strain 1083. With adding 10% cultured solution volume of S. antibioticus strain 1083 into the culture medium of A. hydrophila, after 1 day of inoculation the number of pathogenic bacteria cells were completely eliminated

Conditions for establishing cross-border economic zones in the North of Vietnam

The formation and development of border economic zones (BEZ) and cross-border economic zones (CBEZ) is not only an opportunity for the border regions, but also an engine for developing the supply chain and the production network as a result of border connectivity. The paper focuses on analyzing the conditions for the CBEZ in the border areas in the North of Vietnam, including Cao Bang, Lao Cai, Lang Son and Quang Ninh. There is a big difference in readiness for the establishment of the CBEZ among the four studied sites. However, connectivity needs the most improvement on all the sites, which includes both infrastructure connectivity and policy harmonization

Establishment of a ground surface temperature map for climate change response on the basis of Landsat 8 OLI satellite images

In recent years, in Vietnam, there have been studies using the thermal infrared channel to estimate the surface temperature value, studies using Plank's formula to estimate the surface temperature value from the thermal infrared channel without using the surface emissivity, using the emissivity as a common constant for coating objects [1 – 4]. In the area of Bim Son town – Thanh Hoa province – Vietnam, along with the process of urbanization as well as socio-economic development, the quality of the urban environment, surface coverage by plants and use activities have been greatly affected, especially the limestone mining for cement of one of the largest cement plants in the country (Bim Son cement plant) has had a significant impact on the temperature of the area. The monitoring results have not provided an overview of the temperature background of the whole area of Bim Son town in the period of 2017-2023 in order to assess the change in the temperature background of the region, thereby providing solutions to respond to climate change. The article uses Landsat 8 OLI satellite images to establish a surface heat map for the assessment of climate change for the area of Bim Son – Thanh Hoa, thereby making more general assessments for other areas in Vietnam. The experimental results were compared and evaluated to show the relevance of the data as well as the image processing process

Effects of oil and grape seed tannin extract on intakes, digestibility, milk yield and composition of Saanen goats

An experiment was conducted as a 4×4 Latin square design using 4 lactating Saanen goats, 19 months old and 47.9±1.04 kg of body weight, to evaluate the effect of oil and grape seed tannin extract (GSTE) supplementation on feed intake, digestibility, milk yield and milk composition. Each experimental period lasted for 21 days including 16 days for adjustment and 5 days for sampling. Goats were fed a control diet (Ctrl) consisting of 60% concentrate and 40% fresh Para grass (dry matter, DM, basis) while other 3 treatments were supplementation of 2.5% soybean oil (SO); 2.5% soybean oil + tuna fish oil at 3:2 w:w (SFO); 2.5% soybean oil + tuna fish oil at 3:2 w:w + 0.8% GSTE (OCT). The results showed that oil and GSTE did not affect feed intake, digestibility, milk yield and composition of goats (P > 0.05). However, digestibility of EE was higher (P < 0.05) in SFO and OCT diets (85.4% and 84.7%, respectively) compared with Ctrl (76.2%). Combined data suggested that feeding 2.5% oil blend with or without 0.8% GSTE increased EE digestibility in goats without affecting intake, animal performance and milk composition