bluuebunny/crossref_metadata_2025 huggingface dataset:
EFFECTS OF MALTING CONDITIONS TO QUALITY OF GERMINATED RED SORGHUM
Authors: Cuong Nguyen Tien
Published: April 2018

Sorghum, one of the most popular cereals in the world, can be used directly or in malted and/or fermented form in the preparation of several traditional foods. The aim of this study was to investigate the effects of malting conditions to quality germination of red sorghum in order to select the malted sorghum for beverage production. Twenty malts types originated from red sorghum (Sorghum bicolor L. Moench) were produced under different experimental conditions: steeping (30 °C for 15 - 44 h with and without aeration), germination (30 °C, 98 % relative humidity, 45 - 72 h) and drying or lyophilisation. Dry matter loss, production of sugar, α and β-amylase activities were determined. The obtained results showed the distribution of dry matter loss during malting: steeping (2.2 - 4.0 %), germination (3.7 - 6.5 %), drying (1 %) and degerming (4.3 - 7.5 %). The starch was slightly hydrolysed (2.5 %) for producing soluble sugars: maltose (2.9 - 4.0 %) and glucose (1.7 - 3.6 %). Any organic acids production during the malting was detected. The obtained malted sorghum contained high α-amylase activity but a low level of β-amylase. The highest α- and β-amylase activities were 173.1 U.gms-1 and 3.4 U.gms-1, respectively. These results were obtained for steeping 44 h with aeration, germinated 45 h and lyophilised sorghum. The amylase activities were positively correlated with the water content of grain at the end of steeping.
EXPLORATION OF THE FACTORS AFFECTING THE SOLUBLE PROTEIN EXTRACTION FROM CULTURED SNAKEHEAD FISH (Channa striata) MUSCLE
Authors: Ngan Vo Hoang
Published: April 2018

This study was conducted to identify the factors affecting the soluble protein extraction from cultured snakehead fish muscle, a protein having bioavailability and nutritional value. The study investigated the ratio of fish muscle to water (from 1:1 to 1:5 w/v) and salt (NaCl) concentration (from 0.05 M to 0.25 M) that are suitable for extracting soluble protein effectively. Research has applied a response surface methodology using a central composite design to optimize the effect of temperature and time extraction on soluble protein extraction efficiency. In addition, the study investigated the effect of pH of salt solution (pH 2 to pH 12) on the efficiency of soluble protein extraction from cultured snakehead fish muscle. As a result, the use of 0.15 M NaCl solution with 1:2 ratio of fish muscle to water gave high soluble protein extraction efficiency. The optimum extraction temperature and time were determined as 34.8 °C and 15.2 min respectively, and the appropriate pH value was also determined as pH 10. At the optimum extraction conditions, soluble protein recovery calculated by the amount of soluble protein extraction dividing total protein of fish muscle was 14.39 ± 0.18 %.
IMPROVING THE PHYSICOCHEMICAL PROPERTIES OF SNAKEHEAD FISH (Channastriata) SAUSAGE BY PROTEASE FROM ITS VISCERA
Authors: Truc Tran Thanh
Published: April 2018

The study was conducted to investigate the possibility of enhancing the quality of cultured snakehead fish (Channastriata) protein, especially used in the processing of sausage products, by treatment with protease from its viscera. The change in physicochemical properties (expressed by water holding capacity, emulsifying capacity of protein, texture characteristics and whiteness index) of snakehead fish paste related to various protease activity (0, 3, 6, 9, 12, 15 U/L) and washing time (20, 30 and 40 min) were determined. In addition, protease treatment conditions were fixed at ambient temperature (30 ± 2 °C) and the ratio of minced fish and protease solution was 1:1(w/v). The results showed that physicochemical properties, gel quality and sensory properties of sausage significantly improved from soaked minced fish in protease solution at 9 U/L for 30 minutes.
INFLUENCES OF MALTODEXTRIN AND HOT AIR TEMPERATURE ON LOSSES OF BETACYANIN AND ANTIOXIDANT CAPACITY IN BEETROOT JUICE SPRAY DRYING
Authors: Dat Lai Quoc
Published: April 2018

Beetroot (Beta vulgaris L.), which is rich in betacyanin and antioxidant compounds, has been utilized as a good source of red pigment and antioxidants. Nevertheless, these compounds are thermally sensitive, consequently, being degraded in processes conducted at high temperature. This research focused on effects of maltodextrin and hot air temperature on losses of betacyanin and antioxidant capacity in spray drying of beetroot juice. Results indicated that adding maltodextrin and temperature of hot air significantly influenced on loss by thermal effect, consequently, on the recovery yield of betacyanin and antioxidant capacity of beetroot juice powder. Adding maltodextrin enhanced protection of betacyanin and antioxidants in beetroot juice against thermal effect. Increasing temperature of hot air caused increase in loss by thermal effect of betacyanin and antioxidant capacity. The loss of antioxidant capacity by thermal effect was higher than that of betacyanin. Results also indicated that the suitable conditions of spray drying of beetroot juice are adding maltodextrin to reach 30 % w/w of total solid content and 150 oC of hot air temperature.
FUNCTIONAL PROPERTIES AND INFLUENCES OF COCONUT FLOUR ON TEXTURE OF DOUGH AND COOKIES
Authors: Dat Lai Quoc
Published: April 2018

Coconut flour, a significant byproduct of coconut milk and oil productions, is rich in fiber and protein. It can be utilized as an alternative material for cookies products. This paper focused on the functional properties of coconut flour and effect of coconut flour supplement on texture of dough and cookies. Results indicated that hydration properties and oil binding capacity (OBC) were significantly influenced by size of particles in coconut flour. With increase in size of coconut flour, water absorption capacity (WAC) and swelling capacity (SC) values increased; whereas, OBC value decreased. Maximum value of water retention capacity (WRC) was observed at 0.20–0.25 mm of particle size. Adding coconut flour into dough caused enhancement of hardness, cohesiveness and adhesiveness; whereas, insignificantly influenced on springiness. In addition, adding coconut flour led to decrease in spread ratio and increase in hardness of cookies. The results can be applied for substitution of coconut flour for wheat flour in cookies processing.
RESEARCH ON THE SUITABLE PARAMETERS FOR HYDROLYSIS REACTION OF RED MEAT OF STRIPED TUNA (SARDA ORIENTALIS) BY USING COMMERCIAL PROTAMEX
Authors: Dong Bui Xuan
Published: April 2018

Red meat of Sarda orientalis is one of by-products of tuna processing industry, the source of Sarda orientalis red meat is abundant in Vietnam. Red meat of Sarda orientalis contained       27 % of protein and 0.53 % of lipid, thus, it was classified into lean fish meat and a perfect resource for protein hydrolysate production. The purpose of this research is to hydrolyze Sarda orientalis red meat by using protamex enzyme to obtain protein hydrolysates. The suitable parameters for hydrolysis reaction were reaction time of 4 h, ratio of Protamex enzyme to red meat of 0.4 % (based on the weight of red meat, w/w), and reaction temperature of 55 °C with the maximal value of degree of hydrolysis of 7.03 %. The highest degree of hydrolysis in this research can compare to previous researches.
HIGH SOLID FERMENTATION AT PILOT SCALE FOR POTABALE ETHANOL PRODUCTION FROM RICE
Authors: Nghia Nguyen Chinh
Published: April 2018

In recent year, besides conventional process comprising separated liquefaction, saccharification and fermentation steps, few ethanol distilleries in Vietnam started using Simultaneous Saccharification and Fermentation (SSF) for ethanol production. In this work, we developed an SSF process of rice mash at high solids for potable ethanol production at pilot scale of 30 liters. After investigation on liquefaction and boiling time of five SSF processes, we selected the most suitable one (SSF3) to apply to pilot scale. At pilot scale, rice flour (RF) was dissolved in water to reach 315.4 g/l dry matter, then the mixture was liquefied at 85 oC for 60 min by using an alpha-amylase (Liquozyme SC DS at 45.36 KNU-S/kg RF) and a beta-glucanase (Optimash TBG at 2.812 U/kg CF). The starch slurry was then boiled for 30 min. SSF of liquefied mash was performed at 30 oC with the simultaneous addition of a gluco-amylase (Spirizyme SC DS at 540 AGU/kg RF) and a protease (FermgenTM at 600 SAPU/kg RF), active dry yeast (Ethanol Red at 1.5×107cells/l), urea (12 mM) and KH2PO4 (4 mM). Under these conditions, SSF process finished after 120 h and achieved 16.7  % v/v ethanol, which was equivalent to 87.1  % of the theoretical yield. Therefore, the VHG fermentation of rice flour could be a great potential to be applied in potable ethanol industry in Vietnam.
ISOLATION OF HALOPHILIC LACTIC BACTERIA TETRAGENOCOCCUS HALOPHILUS FROM VIETNAMESE FISH SAUCE
Authors: Nga To Thi
Published: April 2018

Halophilic lactic bacteria Tetragenococcus halophilus were isolated from Thailand fish sauce. They were suggested to play an important role in flavor and aroma development and used as starter culture during fish sauce fermentation.In this study the isolation of Tetragenococcus halophilus from two different factories of fish sauce production in Vietnam was conducted on MRS agar media supplemented with 0.5 % CaCO3 and 5 % NaCl under anaerobic condition. The Tetragenococcus halophilus was present in all investigated fish sauce samples from 2 months to 8 months. Six isolates CH2-4, CCH8-3, CH6-1, CH6-2, CH8-1 and V5-1 were selected based on various ability to grow in fish broth supplemented with 25 % NaCl and degrade fish protein to oligopeptide. The 16S rDNA sequence analysis of 6 isolates showed that they were closely related to Tetragenococcus halophilus ATCC 33315 and Tetragenococcus halophilus MCR10-7-8 and MRC 5-5-2 from study of Thailand scientist with more than 99 % sequence homology, suggesting their potential using as starter culture in fish sauce fermentation.
THE CHANGES OF PROTEIN STRUCTURE IN TILAPIA SURIMI DURING GELATION BY RAMAN SPECTROSCOPY
Authors: Yen Do Thi
Published: April 2018

Structural changes, textural properties in Tilapia surimi myofibrillar protein during gelation were studied by Raman spectroscopy. The change in the amide I (1600-1700 cm-1) region indicated that the decrease in a-helices content accompanied by increase in ß-sheet and random coil after heating. The conformation of S-S bond was observed in the Raman spectrum near 500-600 cm-1 in the samples of 30-40 oC incubation temperature which produce textural profile with high gel strength. Intensity of the band near 758 cm-1 as well as a slight decrease in I853/I826 ratio when the heat increase 60-70 oC showed that the hydrophobic interaction was involved in the heat-induced gelation of surimi protein.
SODIUM LAURYL SULFATE EFFECTS ON ELECTROCHEMICAL BEHAVIOR OF POSITIVE ACTIVE MATERIAL AND COMMERCIAL POSITIVE PLATES IN LEAD-ACID BATTERY
Authors: Nguyen Xuanq Thang
Published: April 2018

Sodium lauryl sulfate (SLS) is an anionic surfactant used in many applications such as cleaning and hygiene products, electroplating, etc. For the first time, effects of SLS as an electroyte additive on electrochemical behavior of positive active material and commercial positive plates have been studied by cyclic voltammetry (CV), eletrochemical impedance measurements. The electrode surface morphology after 20 cycles of CV was studied by using scanning electron microscopy (SEM). Results show  that SLS additive significantly improves the conversion reactions of positive active material and therefore enhances charge/discharge capacity. By increasing SLS concentrate, crystalline structure of positive active material changed. The effects of SLS on kinetic parameters of positive electrode reactions are also discussed in this paper. The results showed that SLS is promising for use as electrolyte additive for lead- acid batteries.
QUALITY REINFORCEMENT OF ELECTROPLATING ZINC COATINGSELECTRODEPOSITED FROM CYANIDE FREE ALKALINE SOLUTION BY POLYAMINE 70.000 AND POLYVINYL ALCOHOL 16.000
Authors: Nam Truong Thi
Published: April 2018

Zinc coatings have been deposited electrochemically from cyanine free alkaline solutions containing zinc ions with the presence of polyamine 70.000 and polyvinyl alcohol at different contents. The scanning electron microscope (SEM) images showed that the size of zinc grains decreased with the presence of polyamine 70.000 and polyvinyl alcohol with smoother surface of zinc coating. The polarization measurements also revealed that the coatings with the presence of polyamine or polyvinyl alcohol possessed higher value of polarity degree. This result is in good agreement with the result obtained from SEM images.
METALLIC LEAD ELECTROREFINING FROM RAW MATERIAL IN LEAD - DIETHYLENETRIAMINE COMPLEX SOLUTION
Authors: Dang Trung Dung
Published: April 2018

Metallic lead was refined from raw material via electrolysis process in lead - diethylenetriamine (Pb-DETA) complex solution with presence of various additives. The influence of the additives, Pb-DETA concentration, current density and temperature on lead deposition, dendrite formation and electric current performance were studied. The additives strongly affect to dendrite formation and the deposition of lead metal in the Pb-DETA complex solution.  The morphology and composition of the electrolyzed lead were analyzed by optical microscope, scanning electron microscope (SEM) and energy-dispersive X-ray spectroscopy (EDX). After electrorefining, the impurities were removed and the product was pure lead metal. The lead diethylenetriamine complex solution with three additives as gelatine, dextrine and β-naphthol is promising electrolyte for lead refining via electrolysis process.
STUDY ON THE PREPARATION OF MANGANESE DIOXIDE VIA CATHODIC ELECTROLYSIS
Authors: Dang Trung Dung
Published: April 2018

A novel synthesis method was developed to prepare manganese dioxide via cathodic electrolysis in potassium permanganate solution. The morphology and the composition of the synthesized products were analyzed by scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDX) and X-ray diffraction spectroscopy (XRD). The electrolyzed products include two kinds of materials: amorphous and crystalline manganese dioxide. The manganese dioxides were formed by cathodic reduction via two reaction mechanisms: direct and indirect electrochemical reactions. The electrolysis current performance strongly depends on the electrolyte solution temperature, applied voltage and not clearly depends on electrolyte solution concentration. With high current performance and uniformity products, the cathodic reduction of potassium permanganate is promising method for manganese dioxide fabrication.
CHARACTERIZATION OF FLUORIDATED HYDROXYAPATITE (FHA) SOL-GEL COATINGS ON TITANIUM SUBSTRATE
Authors: Anh Tuyet Ngo Thi
Published: April 2018

In this paper, FHA coatings [FHA, Ca10(PO4)6(OH)2-x Fx] (wherein 0 ≤ x ≤ 2) were deposited on titanium substrate by sol-gel method with heat treatment at 900 oC for 4 hours. Different concentrations of F- were incorporated into the apatite structure during the sols preparation. The FHA sols were prepared using various amounts of ammonium fluoride [NH4F] with the [P]/[F] molar ratios of 12, 6, 4, 3 in order to have the corresponding compositions of Ca10(PO4)6(F0.5 OH1.5), Ca10(PO4)6 FOH, Ca10(PO4)6(F1.5 OH0.5) and Ca10(PO4)6F2, respectively. The fabricated FHA coatings were assessed by various methods, namely: morphological structure and chemical composition of coatings were studied by scanning electron microscopy (SEM) and Energy dispersive spectrometry (EDS). The anti-corrosion properties of samples were evaluated by Potentiodynamic polarization curves and Nyquist impedance spectrum. The biocompatibility of FHA coatings on titanium substrates were evaluated by in-vitro tests in simulated body fluid (SBF) solution during 21 days, and ICPMS (Inductively Coupled Plasma Mass Spectrometry) analysis method has been used. The results showed that with dense structure, FHA coatings expressed higher anti-corrosion and biocompatibility performance as compared with that of HA coating.
PROTECTION OF STEEL JISG 3141 WITH CHROMIUM-FREE CONVERSION COATING BASED ON INORGANIC SALT (Zr/Ti/Mo)
Authors: Hong Phan Duong Thi
Published: April 2018

Chromium-free conversion coatings based on Zr/Ti/Mo compounds were prepared to improve the corrosion resistance of the SPCC-JISG 3141 steels. Passivation layer containing Zr, Ti and Mo has been successfully carried out on steel by dipping in solution of 17 g/l Na2MoO4, 8 g/l K2ZrF6, 1 g/l H2TiF6 and pH = 5. Scanning electron microscopy couples with energy - dispersive spectroscopy (SEM/ EDX) were used to provide the microscopy structure information and presence of Zr/Ti/Mo on surface of the steels. The corrosion potential and current of coating in case of with and without passivation layer on the steels was determined by potentiodynamic polarization test, showed that the corrosion current density decreased when using Zr/Ti/Mo coating. The passivation layer provided the corrosion resistance of coating. Furthermore, the salt spray test (Model SAM Y90) evidenced the higher corrosion resistance of the coated samples compared to bare steel when electro - deposition coating (ED) applied. The treatment using inorganic salt could significantly increase the anticorrosion of steels with their environment-friendly.
SIMULTANEOUS DETERMINATION OF DOPAMINE IN THE PRESENCE OF ASCORBIC ACID AND URIC ACID BY ELECTROCHEMICALLY OXIDIZED SCREEN PRINTED CARBON ELECTRODE
Authors: Viet Nguyen Xuan
Published: April 2018

This research reported the simple method to determine of dopamine (DA) in the simultaneous presence of ascorbic acid (AA) and uric acid (UA). Three – electrode system manufactured by screen printing method was used due to its disposal and low cost. The screen printed carbon electrode (SPCE) was oxidized by electrochemical technique in acid medium. The capacity of oxidized electrode for selective detection of dopamine was confirmed in a sufficient amount of ascorbic acid and uric acid. The large separated peaks of DA from ascorbic acid and uric acid are observed. The peak separation between UA and DA, DA and AA was 110 mV and 160 mV, respectively. The bare SPCE cannot determine simultaneously AA and DA due to the overlap peaks of AA and DA around 0.2 V vs AgCl/Ag. This sensor also exhibited good sensitivity to DA with limit of detection 100 nM in phosphate buffer solution.
SYNTHESIS AND STRUCTURAL CHARACTERIZATION OF PALLADIUM(II) COMPLEXES WITH TETRADENTATE N2O2 AND BIDENTATE NO-DONOR SALICYLALDEHYDE SCHIFF BASE LIGANDS
Authors: Hai Lam Quang
Published: April 2018

In this study, a salen-type (R)- and (S)-N-5-tert-butyl-salicylidene-1-phenylethylamine Schiff base ligands and their Pd(II) complexes were synthesized and characterized by ESI-MS, IR and NMR spectroscopies. The ligands were synthesized from the condensation of ethylenediamine with 5-fluoro-salicylaldehyde and (R)- or (S)-1-phenylethylamine with 5-tert-butyl-salicylaldehyde with high yields of 96,3-97.5 %. Their corresponding Pd(II) complexes were formed with yields around 76 %.
A STUDY ON PRASEODYMIUM 4-HYDROXYCINNAMATE AS AN INHIBITOR FOR CARBON STEEL IN FRESH COOLING WATER SYSTEM OF CA MAU FERTILIZER PLANT
Authors: Ngan D. T.
Published: April 2018

Praseodymium 4-hydroxycinnamate compound has been successfully studied as an effective corrosion inhibitor for carbon steel in 0.1 M NaCl solution using electrochemical techniques and surface analysis. The results of electrochemical techniques indicated that there were the decrease of current density and the appearance of protective film on the steel surface evidencing the presence of inhibitor and the effect of Pr(4OHCin)3 compound depending on its concentration in solution. The surface analysis show a confirmation of the protective film formation which is a result of adsorption between the metal and inhibitor components. In addition, inhibition performance of Pr(4OHCin)3 compound is also compared to the inhibition performance of TRACT 109, which has been added to a fresh cooling water system of Ca Mau fertilizer plant.
EFFECT OF ANION GROUPS ON CORROSION INHIBITION BEHAVIOURS OF VIETNAM ORANGE PEEL ESSENTIAL OIL FOR MILD STEEL IN THE ACIDIC MEDIA
Authors: Thanh Huyen Bui Thi
Published: April 2018

This paper deals with the effect of anion groups (SO42- and Cl-) on inhibition behaviours of Vietnam orange peel essential oil (OPE) for corrosion process of mild steel in acidic media. The electrochemical techniques (potentiodynamic, electrochemical impedance spectroscopy (EIS)), weight loss and scanning electron microscopy (SEM) analyses are used in this study. The results show that anion groups do not affect the inhibition mechanism of OPE. The OPE ­behaves as mixed inhibitor for mild steel corrosion in both 1N HCl and H2SO4 acid. The inhibition efficiency of OPE in 1N HCl is greater than that in 1N H2SO4 which implies that the adsorption of the inhibitor is influenced by the nature of anions in acidic solutions. Moreover, the OPE inhibits both general and pitting corrosion for mild steel in the acidic media.
A STUDY ON THE KINETICS OF OXYGEN REDUCTION FOCOAR
Authors: Khanh Le Quoc
Published: April 2018

In poor oxygenated environments the oxidation and growth of the living organisms are slowed or stopped, so that food is better preserved. The most appropriate method for oxygen depletion in the air-tight minienvironment is oxygen reduction with iron-based reducing agent, which can reduce the air oxygen concentration to about 0 %, and maintain this low oxygen concentration long during storage. This paper studies the kinetics of oxygen reduction by reducing agent FOCOAR in an airtight minienvironment under isobaric conditions. The kinetics of the reduction process calculated according to the relation vav = [21 % - (end) ] / tend, in which vav is average reduction rate, (end) is oxygen concentration at the end of the experiment, tend is total time needed for the oxygen reduction experiment. Instantaneous reduction rate vred was calculated according to equation vred = ∆/△t, in which ∆is oxygen concentration reduced in time △t, and △t = ti+1 - ti is time interval for oxygen reduction. It is found that vav depends on the quantity of reducing agent FOCOAR, and in certain time interval varies as linear function of reduction time, corresponding to constant vred.  The kinetic result allows an estimating the amount of the reducing agent FOCOAR needed for a preserve minienvironment.
CORROSION INHIBITION OF CARBON STEEL BY LDH/GO HYBRID INTERCALATED WITH 2-BENZOTHIAZOLYTHIO-SUCCINIC ACID
Authors: Duong Nguyen Thuy
Published: April 2018

Layered double hydroxide/graphene oxide hybrid (LDH/GO) intercalated with corrosion inhibitor 2-benzothiazolylthio-succinic acid (BTSA) was prepared using co-precipitation method. The synthesized LDH/GO-BTSA was characterized by FTIR, XRD and SEM. The inhibitive action of LDH/GO-BTSA on carbon steel was evaluated and compared with LDH-BTSA by electrochemical measurement. It was shown that the GO and BTSA were intercalated in LDH structure. The obtained results showed that LDH/GO-BTSA is anodic corrosion inhibitors, and the inhibition efficiency was 94 % at concentration of 1 g/l.
STUDY ON ELECTRO-OXIDATION OF GLYCEROL IN ALKALINE MEDIUM USING TRIMETALLIC Pt-Pd-Ni COMPOSITE ELECTRODEPREPARED ON GLASSY CARBON
Authors: Lan Phuong Huynh Thi
Published: April 2018

In this research, the effect of temperature and conversion of glycerol was studied by using cyclic voltammetry technique. The results showed that this reaction occurred following to diffusion mechanism with activation energy approximately of 3.44 (kcal/mol). Moreover, conversion of glycerol by electrolysis using Pt-Pd-Ni/C catalyst also was investigated and compared with the case of using pure Pt. Electrolysis process with electrode Pt-Pd-Ni/GC and pure Pt-was occurred by the first order and this result was well-suit with the previous study about the reaction mechanism of glycerol electro-oxidation process. Obtained results showed that conversion of glycerol on the trimetallic catalyst was higher than the pure Pt.
UNDERSTANDING CORROSION BEHAVIOR OF Zn AND Zn ALLOY GALVANIZED STEELS IN HUMID TROPICAL CLIMATE
Authors: Tru Nguyen Nhi
Published: April 2018

The humid tropical climate parameters and airborne salinity are generally considered important factors affecting detrimental corrosion of zinc and its alloy coatings. To more thoroughly understand their corrosion performances, the five years weathering tests for zinc and Zn-Al galvanized steels in rural and coastal humid tropical areas were conducted. Corrosion rates and other performance characteristics of zinc and Zn-Al coated samples were determined and discussed in relation with climatic and environmental parameters. Behavior of the coatings in rural and coastal tropical conditions revealed a strong influence of time of wetness (TOW) and airborne salinity on corrosion rates. In both test conditions, the dependence of coating’s mass loss on exposure time shows that the corrosion process of zinc coatings mostly obeys the law of power model M = Atn. Corrosion is recorded considerably stronger in the coastal atmosphere containing higher chlorides. The laboratory observation in cut-edge area of zinc alloys coated steel was also conducted and their corrosion behavior was detailed in condition of chloride ions attack.
BENTONITE PILLARED BY MESOPOROUS SILICA AND ITS APPLICATION FOR GASOLINE TREATMENT
Authors: My Nga Vo Thi
Published: April 2018

Di Linh bentonite was successfully pillared by mesoporous silica and this result had been published in previous reports. The acidity of this material was estimated by modern physico-chemical methods such as IR, TPD-NH3and the material was applied in the field of petrochemical catalysis. The acidity of the material has also been demonstrated by Cumen cracking at low temperatures about 350 °C with benzene conversion of 36.46 % and benzene selectivity of 73.98 %. In addition, the gasoline yield of silica mesoporous material pillared bentonite had got more twice higher than the one when using a mixture of bentonite powder and MCM-41 powder in the cracking Wax. This result confirms that the bond formation between bentonite and mesoporous silica when using one-step method, which increase  acidity of the synthesized material.
CORROSION PROTECTION AND CHACRACTERISTICS OF Ni-CeO2-CuO ELECTROPLATING LAYER ON STEEL SUBSTRATE
Authors: Phuoc Mai Van
Published: April 2018

The particles of CeO2  and CuO are capable of catalyzing the oxidation reaction of carbon monoxide and hydrocarbons at low temperature, especially at nanometer size. They can be deposited on the metal material surface by using electroplating method. This paper reports some results on corrosion resistance, wear resistance, adhesion strength and catalytic behavior of Ni-CeO2-CuO composite by electroplating on steel substrate from nickel sulfate solution using CeO2 and CuO particles with 40÷60 nm size.
SYNTHESIS AND CATALYTIC ACTIVITY OF BRANCHED GOLD NANOPARTICLES IN AQUEOUS MEDIUM
Authors: Nu Diem Phan Ha
Published: April 2018

In this article, a simple method for the preparation of multi–branched gold nanoparticles from an aqueous solution of silver seeds, cetyl-trimethylammonium bromide (CTAB), HAuCl4, and Pluronic F–127 was described. It was found that morphologies and sizes of gold nanostructures (AuNPs) depended strongly on such experimental parameters as concentrations of Pluronic F–127 and Au3+. The products were characterized by transmission electron microscopy (TEM). Interestingly, the multi – branched AuNPs were found to serve as an eﬀective catalyst for the reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) in the presence of NaBH4. Kinetic data have been obtained from monitoring the concentrations of 4-NP and BH4‒ by UV‒vis spectroscopy.
STUDY ON THE PROPERTIES OF SILVER PLATING ON A6061 ALUMINUM ALLOY
Authors: Thanh Vu Minh
Published: April 2018

This article presents the properties of the silver plating on A6061 aluminum alloy. The structure, chemical composition, phase composition, thickness and corrosion durability of the plating are determined by scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS), X-ray diffraction, corrosion current measurement, frost acceleration and hygrothermal test. The results show that the silver plating has good corrosion resistance, is not blistered, remains white, light, no appearance of rust and other abnormalities. These parameters meet the technical requirements laid out for resonator of ultra - high frequency filter.
PREPARATION AND CHARACTERIZATION OF POROUS CARBON FROM RICE HUSK APPLIED FOR ELECTRODE MATERIALS
Authors: Thu Huyen Nguyen Thi
Published: April 2018

Rice husk (RH) was used as the precursor for porous carbon preparation applying as electrode materials. Porous carbon was synthesized by pyrolysis of RH under inert gas atmosphere followed by hydrothermal treatment in NaOH to remove the silica fraction and K2CO3 activation to increase porosity of archived carbon. The temperature of RH decomposition was determined by the thermal gravimetric analysis (TGA) method in the nitrogen atmosphere. The performance of porous carbon and C-SiOx were examined using Brunauer-Emmett-Teller (BET) measurement and Scanning electron microscopy (SEM). The electrochemical characterizations of the synthesized materials were analyzed using cyclic voltammetry (CV) and chronopotentiometry techniques. The effect of parameters of hydrothermal and activation steps on the capacity of these porous carbons were researched. The activated porous carbon which obtained by K2CO3 activation at 9000C in 2 hours has high specific surface area (SBET = 769.3 m2/g). Specific capacitance of the as-prepare electrode is 116.2 F.g-1 at scan rate of 5 mV/s. Therefore, as-prepared porous carbon from RH would be proper candidate for application as electrode material.
THE EFFECT OF NANOCARBON MATERIALS STRUCTURES ON THE PERFOMANCES OF EPOXY-BASED PAINT COATING FOR STEEL SURFACES
Authors: Thuy Hang Phan Thi
Published: April 2018

This paper reports the effect of the nanocarbon materials addition on the physico-mechanical properties and corrosion protective ability of epoxy based paint coatings for the steel surfaces. In this work the nanotubes and nanosheets (layers) structures of nanocarbon materials were used for the investigation. The properties of received products were measured by the test techniques for paint coating characterization. The results showed that the addition of the nanocarbon materials (only ratio of 0.1 wt%) significantly improved the physico-mechanical performance and corrosion protection ability of epoxy coatings for steel surfaces. However improvement quantity depends on the structure of nanocarbon materials. The obtained results showed that the nanosheets structure of carbons coatings made the physico-mechanical properties of the epoxy coating increased better than those of nanotube structure.
OPTIMAL PLACEMENT AND ACTIVE VIBRATION CONTROL OF COMPOSITE PLATES INTEGRATED PIEZOELECTRIC SENSOR/ACTUATOR PAIRS
Authors: Tham Vu Van , Quoc Tran Huu , Tu Tran Minh
Published: April 2018

In this study, a finite element model based on first-order shear deformation theory is presented for optimal placement and active vibration control of laminated composite plates with bonded distributed piezoelectric sensor/actuator pairs. The model employs the nine-node isoparametric rectangular element with 5 degrees of freedom for the mechanical displacements, and 2 electrical degrees of freedom. Genetic algorithm (GA) is applied to maximize the fundamental natural frequencies of plates; and the constant feedback control method is used for the vibration control analysis of piezoelectric laminated composite plates. The results of this study can be used to aid the placement of piezoelectric sensor/actuator pairs of smart composite plates as well as for robust controller design.
LARGE-SCALE MIMO MC-CDMA SYSTEM USING COMBINED MULTIPLE BEAMFORMING AND SPATIAL MULTIPLEXING
Authors: Trung Nguyen Huu , Binh Doan Thanh
Published: April 2018

This paper proposes a novel Large-scale (massive) Multi-input Multi-output Multi-carrier Code division multiple access (LS MIMO MC-CDMA) model and application to Fifth-Generation Mobile Communication Systems (5G). This system uses combined cylindrical array antenna multiple beamforming architecture with spatial multiplexing. The model is optimized by Min-Max criteria in order to minimize side lobes and maximize compression of propagation loss. The Monte Carlo simulation results unify with the analytical solution for system performance.
The influence of carbon additive on the electrochemical behaviors of Fe2O3/C electrodes in alkaline solution
Authors: Anh Trinh Tuan , Thang Doan Ha , Hang Bui Thi
Published: April 2018

Acetylene Black (AB) and Fe2O3 nanoparticles were used as the additive and active materials, respectively for preparing Fe2O3/AB composite electrode. The effects of carbon additive and binder content on the electrochemical properties of Fe2O3/AB electrodes in alkaline solution were investigated to find the suitable anode for the Fe/air battery. The results of electrochemical measurements showed that both the AB additive and binder content significantly affected on the electrochemical behaviors of Fe2O3/AB electrodes. AB additive improves in redox reaction of iron oxide.
RECONSTITUTION OF DIFFERENT SIGNAL PEPTIDES FOR ENHANCED THERMOSTABLE ALPHA AMYLASE SECRETION IN Bacillus subtilis
Authors: Da Nguyen Thị , Man Tran Dinh , Thoa Nguyen Kim
Published: April 2018

Three signal peptides of alpha amylase genes of three isolated strains that were Bacillus licheniformis DA23, Bacillus subtilis D5-2, Bacillus cereus CN1-5 were successfully sequenced. Three predicted “Sec – type” signal peptides have a length varying from 27 (CN1-5) to 33 residues (D5-2).  The secretion of alpha amylase of the recombination B. subtilis 168MPgrac strain (pHV33–PgracAmy3BT2) with 71.4U/ml was larger than that of 168MPamy with 53.2U/ml. Base on analyzed rerults of PAGE and zymogram about molecular weight, alpha amylases in both strains were the same size, nearly 58kDa. The extracellular amylase activity of signal peptide SsubtilisD5.2 in 168M was highest with 76.4±4.3 U/ml in four signal peptide targets.
NUCLEOTIDE DIVERSITY OF 15 CONIFER SPECIES IN VIETNAM’ S CENTRAL HIGHLANDS BASED ON THE ANALYSIS OF ITS, trnH-psbA, matK, trnL AND rpoC1 GENE REGIONS
Authors: Phong Dinh Thi , Hien Vu Thi Thu , Lieu Tran Thi
Published: April 2018

In this study, five DNA sequences from ITS, trnH-psbA, matK, trnL and rpoC1 gene regions were used to explore relationships of 15 conifer species in Highlands of Vietnam. All target gene segments has been cloned at size as predicted by the theory for all 15 species of conifers. Nucleotide-level change of 15 coniferous species in five gene regions showed from the highest to the lowest as follows: the ITS gene region (0.428),  the trnH-psbA region (0.378), the trnL (0.354), the matK gene (0.192) and the rpoC1 gene (0.105). The matK gene region showed the highest level of conservation (671 nucleotides) and the trnH-psbA gene region showed the lowest (78 nucleotides). Phylogenetic tree showed that the species in the same family are formatted in a separate evolutionary branch with bootstrap values ​​obtained from the branching nodes of each species ranging from 52 to 97% for the ITS gene, from 50 to 100% for trnH-psbA gene region, from 66 to 100% for matK gene region, from 50 to 100% for trnL gene region and from 57 to 100% for rpoC1 gene region. Of the three gene regions of matK, trnL and rpoC1, the grouping of species in the same family showed the most obvious. This result suggests the three gene regions of matK, trnL and rpoC1 could be used as barcode for the 15 conifer species in central highlands of Vietnam.
AMMONIA-REMOVAL EFFICIENCY OF A NOVEL ACINETOBACTER CALCOACETICUS STRAIN ISOLATED FROM INDUSTRIAL WASTEWATER OF NINH BINH COAL NITROGENOUS FERTILIZER PLANT
Authors: Cuong Do Bien , Han Hoang Ngoc , Thiem Pham Van
Published: April 2018

Ammonium removal from wastewaters has recently became a major concern of fertilizer manufacturers and industrial zones in Vietnam. Using aerobic ammonium remover may be a appreciate solution for reduction of treatment cost. This study describes the isolation and characterization of a novel bacterium for ammonium removal under aerobic conditions. Twelve ammonium remover strains were isolated from wastewater of a local fertilizer industry. The isolated strains were initially screened using solid media for their nitrifying activities. Among them two of the bacteria displayed the highest removal of ammonium without much accumulation of nitrite and nitrate. The isolates were identified as Acinetobacter based on biochemical characteristis and 16S rRNA sequence. One of these two isolates, Acinetobacter calcoaceticus A8 strain, showed 88% ammonium removal from industrial fertilizer wastewater.
A STUDY ON THE LOCALIZED CORROSION INHIBITION FOR MILD STEEL IN SALINE SOLUTION
Authors: Nam Nguyen Dang , Hien Pham Van , Vaka Mahesh
Published: April 2018

In this study, 0.45 mM yttrium 4-nitrocinnamate (Y(4NO2Cin)3) embedded in various aqueous chloride solutions, which has been studied as a possible localized corrosion inhibition system using electrochemical techniques and surface analysis. Furthermore, a wire-beam electrode (WBE) exposed to NaCl solutions containing Y(4NO2Cin)3 compound. The results indicated the possible application of a WBE in simulating and monitoring the localized corrosion inhibition. Moreover, Y(4NO2Cin)3 compound showed an excellent localized corrosion inhibition at 0.01 M due to high inhibition performance and good protective film formation. It also indicated that addition of 0.45 mM Y(4NO2Cin)3 compound increased the localized corrosion inhibition with a decrease of the Clˉ ion concentration in the investigated solutions. A new method of localized corrosion inhibition estimation has been developed using a WBE which shows a consistent result with electrochemical and surface analysis data. In addition, other electrochemical techniques and surface analysis are also used for not only ensuring but also confirming the localized corrosion inhibition.
SPATIAL-SPECTRAL FUZZY K-MEANS CLUSTERING FOR REMOTE SENSING IMAGE SEGMENTATION
Authors: Sinh Mai Dinh , Long Ngo Thanh , Hang Trinh Le
Published: April 2018

Spectral clustering is a clustering method based on algebraic graph theory. The clustering effect by using spectral method depends heavily on the description of similarity between instances of the datasets. Althought, spectral clustering has been significant interest in recent times, but the raw spectral clustering is often based on Euclidean distance, but it is impossible to accurately reflect the complexity of the data. Despite having a well-defined mathematical framework, good performance and simplicity, it suffers from several drawbacks, such as it is unable to determine a reasonable cluster number, sensitive to initial condition and not robust to outliers. In this paper, we present a new approach named spatial-spectral fuzzy clustering which combines spectral clustering and fuzzy clustering with spatial information into a unified framework to solve these problems, the paper consists of three main steps: Step 1, calculate the spatial information value of the pixels, step 2 applies the spectral clustering algorithm to change the data space from the color space to the new space and step 3 clusters the data in new data space by fuzzy clustering algorithm. Experimental results on the remote sensing image were evaluated based on a number of indicators, such as IQI, MSE, DI and CSI, show that it can improve the clustering accuracy and avoid falling into local optimum.
EFFECTS OF COD/TN RATIO AND LOADING RATES ON PERFORMANCE OF MODIFIED SBRs IN SIMULTANEOUS REMOVAL OF ORGANIC MATTER AND NITROGEN FROM RUBBER LATEX PROCESSING WASTEWATER
Authors: Nam Duong Van , Chau Nguyen Hoai , Tatsuhide Hamasaki , Vien Dinh Van , Hung Phan Do
Published: April 2018

Two modified sequencing batch reactors (SBRs) specially configured to consist of both oxic and anoxic zones, and be operated with only a single simultaneous oxic/anoxic phase in each treatment batch were tested to evaluate their applicability in treatment of rubber latex processing (RLP) wastewater. The former, R1 was operated with constant aeration, whereas the latter, R2 was operated with air flow varied from lower rate in the early period of the reaction phase to higher rate in the later one. Effects of the chemical oxygen demand (COD) to total nitrogen (TN) ratio and their loading rates on performance of the modified SBRs in simultaneous removal of organic matter and nitrogen from RLP wastewater were investigated. It was observed that performance of the two reactors in removal of COD and ammonium nitrogen was similar, and did not remarkably change when varying COD/TN ratio, as well as COD and TN loading rates in the ranges of 3.4 – 6.0 gCOD/gN, 0.8 – 1.7 kgCOD×m-3×d-1 and 0.15 – 0.34 kgN×m-3×d-1, respectively. The average COD removal efficiencies were over 95%. Ammonium nitrogen was almost completely eliminated in both reactors with effluent concentrations lower than 1.0 mg/L. Nevertheless, TN removal efficiencies of both reactors were significantly increased with increasing the COD/TN ratio from 3.4 to 6.0, and slightly decreased when increasing the TN loading rate from 0.15 to 0.34 kgN×m-3×d-1. The most effective COD/TN ratios were in the range of 5 – 6, at which the maximal TN removal efficiencies of R1 and R2 were 92% and 97%, respectively.
USING LANDSAT SATELLITE IMAGES AND GIS TO ESTIMATE AND MONITOR THE AMOUNT OF ABSORBED CO2 IN DIPTEROCARP FOREST, DAK LAK PROVINCE
Authors: Trinh Huynh Thi Kieu , Duc Bui Hien
Published: April 2018

Dipterocarp forest is a typical ecosystem in Central Highlands of Vietnam and Dak Lak province. Dipterocarp forest plays significant role about biodiversity values, CO2 absorption and concentration. However, there is a lack of awareness of biological potentials in the local people after years of logging. It is necessary to collect data about forest biomass and carbon stored on maps by space and time in order to estimate and monitor CO2 absorbed in the large area. Hence, using GIS to develop relationships between biomass factor and carbon stock with digital values for monitoring carbon sequestration is important and meaningful in dipterocarp forest ecosystem; this method can generate the necessary database and information in terms of CO2 emission. The research results can create a basis for the dissemination and promotion of payment for environmental services according to REDD+ program.Unsupervised classification into 3-4-5 class and overlap forming combinations were close relationships with TAGTB derived from square plots (30x30m) and achieved confidence level 86.8% which were applied to estimate biomass and forest carbon through Landsat image. In this study, remote sensing and management of data in ArcGIS software through allometric equations model showed dipterocarp forest in Ea Soup and Ea Hleo districts (Dak Lak province) with a total area of 125,404.8 hectares and biomass tanks (above and below ground) of forest trees reaching at 8,156,667.6 tons. Total carbon was stored 4,093,501.1 tons. Total CO2 was absorbed 15,023,149.1 tons.
SEEDED GROWTH SYNTHESIS OF GOLD NANORODS FOR PHOTOTHERMAL APPLICATION
Authors: Do Hue Thi , Duong Vu Thi Thuy , Nghia Nguyen Trong , Tran Nhung Hong , Nghiem Lien Thi Ha
Published: April 2018

In this paper, the gold nanorods (GNRs) were synthesized via a seed-mediated method using 1-3 nm seeds-in diameter and gold atoms created from the reduced Au3+ ions by ascorbic acid (AA) in the presence of cetyltrimethylammonnium bromide (CTAB) as a surfactant templating. The aspect ratio of GNRs as well as growth yield was controlled by adjusting the concentration of Ag+ ions.
USE OF WHEY PROTEIN FOR ENCAPSULATION AND CONTROLLED RELEASE OF PROBIOTIC FROM PROTEIN MICROENCAPSULE IN EX VIVO PORCINE GASTROINTESTINAL CONTENTS
Authors: Le Nguyen Thi My , Hieu Nguyen Van
Published: April 2018

The aim of this study was to evaluate the efficacy of whey protein isolate (WPI) as an encapsulation matrix for improvement of L. fermentum 39-183 viability to low pH and bile and releasing the encapsulated bacteria in ex vivo porcine gastrointestinal (GI) contents. 1g of protein microcapsules (≈ 108 CFU of L. fermentum 39-183 or E. coli GFP+) were incubated in ex vivo porcine GI contents (9 mL) under anaerobic conditions at 370C. Results showed that there was higher than 86% cell survival for encapsulated L. fermentum 39-183 after 3 h incubation in pH 2.0, whereas free cell experienced complete viability loss. Encapsulated L. fermentum 39-183 showed only about 0.86 log reduction for all bile salt levels tested (0.5 ÷ 2.0%), while 3.34 log decrease of free cell after 6 h of incubation. There was almost a complete release (3.9 x 108 CFU) of microencapsulated bacteria in the ileal contents within 2 h, while there was no significant release of encapsulated bacteria in the gastric contents even after 8 h of incubation. This study led to the development and design of a protein capsulation for reinforced probiotic protection during the stressful conditions of gastric and controlled release at a defined location.
Construction and demolition waste as partial cement replacement
Authors: Rocha Sabina , Sousa-Coutinho Joana
Published: April 2018

In recent years several studies have been carried out using waste from various industries to partially replace cement in concrete. In addition to improving concrete durability, the use of these waste materials also contributes to reducing emissions, mainly carbon dioxide, and to saving resources. In this study, the applicability of finely ground construction and demolition waste (CDWg) in concrete as a partial substitute for Portland cement was evaluated and the effects on durability were assessed. Mortars and pastes with cement replacements of 0%, 5% (CDWg5) and 10% (CDWg10) were produced. The different mortar types were tested to ascertain their 7, 28 and 90 d strengths and durability-related properties, including capillary absorption, chloride diffusion, accelerated carbonation, resistance to alkali–silica reaction (ASR) and sulfate attack. Mortar containing CDWg performed better than the control only with regard to expansion due to ASR. In the other tests, mortar containing CDWg did not attain the performance of the control specimens. However, for the CDWg5 mortar, performance losses were not significant, indicating that this particular waste at this dosage may be used to partially replace Portland cement. A replacement of 10% could be considered in concretes with lower levels of performance requirements.
Effect of chemico-osmosis on solute transport in clay barriers
Authors: Malusis Michael A , Scalia Joseph , Norris Anna S , Shackelford Charles D
Published: April 2018

The significance of chemico-osmosis on solute transport through clay barriers exhibiting membrane behaviour was investigated by conducting coupled solute transport model simulations in which the effect of chemico-osmosis was either included or omitted. Results show that percentage reductions in solute flux (P RF) through a clay barrier increase with increasing membrane efficiency coefficient, ω; decreasing Péclet number, P e (representing the relative importance of advection to diffusion); and increasing osmotic number, N π (representing the relative importance of chemico-osmosis to diffusion). Predicted P RF values under diffusion-dominated conditions (P e = 0·01) based on experimental data reported for bentonite barriers in contact with monovalent salt solutions (0·015 ≤ ω ≤ 0·73; 0·049 ≤ N π ≤ 0·30) ranged from 3·8 to 74% when the effect of chemico-osmosis was omitted (i.e. by setting N π = 0). When the effect of chemico-osmosis was included, P RF increased by 0·5–10%, indicating that chemico-osmosis has only a minor influence on solute transport in bentonite barriers exhibiting N π ≤ 0·30.