bluuebunny/crossref_metadata_2025_split huggingface dataset:
FACTORS THAT AFFECT THE REMOVAL OF NITROGEN AND PHOSPHOROUS FROM PIGGERY WASTEWATER USING MICROALGAE –BACTERIA CONSORTIUM
Authors: Chien Ngo Van 
Published: April 2018

Currently, most piggery farms in Viet Nam use biogas tank as a primary wastewater treatment system. However, even after the anaerobic treatment process, the concentration of nutrients was still high and exceeded the national effluent standard. If the wastewater was directly discharged into the water bodies, it was certainly hazardous to the environment and causes eutrophication. To remove the residual nutrients, several processes have been used, mostly chemical processes. The disadvantages of those chemical processes are high cost and the increase in amount of sludge. In this study, the biological method using microalgae-bacteria consortium was applied for the removal of nitrogen and phosphorous from wastewater from biogas treatment process. This study focused on factors which affect nitrogen and phosphorous removal efficiency in a batch reactor using microalgae-bacterial consortium. Studying on Chlorella sp A8. Activated sludge co-cultivation at different ratio (Chl/AS) gave good results in hydraulic retention time of 20 to 24 hours when C/N in wastewater was 4/1(m/m). In the fully mixing condition, DO range from 0.3 - 0.5 mg O2/L, the highest removal efficiencies of COD was 71 - 76 %; NH4+-N was 40 - 47 % and PO43--P was 64 - 77 % at Chl /As was 1.5:1, 2.5:1 and 1:1( g/g).
SYNTHESIS OF HYDROTALCITE POWDER AND BEAD TO REMOVE ARSENATE
Authors: Thanh Tung Nguyen 
Published: April 2018

The affecting factors on the synthesis of hydrotalcite (HT) powder and bead for effective arsenate removal were investigated. HTs with a ratio of Mg:Al = 2:1 (MA) were synthesized by the co-precipitation method at 70 oC with reaction times of 1 and 120 - 300 min. The synthesis of MA with a reaction time of 1 min was done under high supersaturation condition, the others under low supersaturation conditions. The characteristics of MA were examined by X-ray diffraction (XRD), scanning electron microscopy, and nitrogen adsorption/desorption isotherms. According to the XRD patterns, pure HT was obtained for all tested conditions. With increasing reaction time from 1 to 300 min, the crystal size of MA increased from 4.9 to 11.3 μm, the surface area of MA increased from 9.3 to 71.4 m2/g. Batch-mode experiments showed that 1-min reaction time MA had the highest As(V) removal capacity. MA beads were separately synthesized using alginate and poly acrylamide (PAM) as binding agents. For alginate/MA, heat drying (110 oC) and freeze drying were applied to test the effect of these drying methods on the beads. The results showed that As(V) adsorption capacity of PAM/MA was the highest, closely followed by freeze drying/alginate/MA, much higher than that of heat drying/alginate/MA bead.
FABRICATION OF CELLULOSE-BASED CHITOSAN COATING ADSORBENTS FOR CAPTURE TO CADMIUM (II) AND ZINC (II)
Authors: Cam Trang Truong Thi 
Published: April 2018

Cellulose fiberous adsorbent (CCCF) was prepared from sugacane agasse by coating chitosan on the fiber surface. The chitosan layer coated on the cellulose fiber enhanced adsorption to Cd2+ and Zinc2+. High efficency of the CCCF of removal % for the Cd (II) and Zn (II) was with 93.7 % and 93.0 %, respectively and the adsorption capacity was 2.0 mg/g.
STUDY OF SOME PARAMETERS RESPONSIBLE FOR GLYPHOSATE HERBICIDE MINERALIZATION BY ELECTRO - FENTON PROCESS
Authors: Le Thanh Son 
Published: April 2018

Glyphosate (C3H8NO3P) is a highly effective broad-spectrum, post-emergence, non- selective organophosphate herbicide and commonly applied in Viet Nam. The removal of glyphosate in aqueous solution has been investigated by electro - fenton process which is based on the continuous production of ●OH radicals by reaction between Fe2+ catalyst and H2O2 electrochemical generated on cathode. The carbon felt (60 cm2) and Pt gauze (45 cm2) were used as cathode and anode of the electro-fenton system, successively. Monitoring the total organic carbon (TOC) during the electrolysis proved that pH, current intensity, electrolysis time and catalyst concentration influenced the glyphosate mineralization efficiency. At the optimal conditions: [Fe2+] = 0.1 mM; pH = 3; [Na2SO4] = 0.05M ; I = 0.5A and the compressed air was bubbled through the solutions, the experiment results showed that 84.4 % Glyphosate was mineralized to CO2, H2O and inorganic acid after 50 min.
STUDY ON PRE-TREATMENT OF THE PHENOL, COD, COLOR IN THE COKE WASTEWATER BY OZONATION PROCESS
Authors: Thao Nguyen Thanh 
Published: April 2018

This paper aims to study destroying process of phenol, COD, color in coke wastewater by ozone process. All experiments were conducted in the bath type reactor on phenol solution prepared in lab. The results showed that removal efficiency of the phenol, color and COD were high relatively. Experiments were realized in the different conditions: phenol concentration: 260; 500 and 720 mg/L; COD corresponding 610; 1200 and 1700 mg/L; inlet ozone concentration from 1.1 to 1.7 g/L.h to study the effect of pH, rotary of magnetic and phenol concentration. The main results showed that phenol removal efficiency was of 98 %; COD of 75 % after 22 minutes of reaction at ozone dose 1.7g/L.h for initial phenol 260 mg/L. Ozone treatment has highest treatment efficiency with phenol but reduction rate of COD was much slower than phenol.
PHOTOCATALYTIC DEGRADATION OF PARAQUAT USING N-TiO2/SiO2 UNDER VISIBLE LIGHT
Authors: Phuong Mai Nguyen Thi 
Published: April 2018

In the present paper, photocatalytic degradation of paraquat using N-TiO2/SiO2 with different molar ratio of titanium: nitrogen (Ti:N) under visible light was investigated. The catalyst was prepared via immersed SiO2 in N-TiO2. N-TiO2 was synthesized by sol-gel method. The N-TiO2/SiO2 catalyst was characterized using X-ray diffraction, UV diffuse reflectance spectroscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy. The results from characterizations indicated that N-doped anatase TiO2 had a 20-25 nm size. Degradation of paraquat, at an initial concentration of 10 mg/L was determined by UV-Vis. Chemical oxygen demand (COD) was used for process performance. Based on the COD tests, the COD values in residual paraquat was lower than that in initial paraquat concentration after 8 hours illumination of visible light. Moreover, the experiment’s results indicated that 80% of paraquat was degraded within 8 h of illumination time. These results showed that N-TiO2/SiO2 with molar Ti:N=2:1 gives the highest degradation efficiency of paraquat under visible light. This catalyst was stable and reusable suggesting it can be applied to treat organic pollutant in water.
ADVANCED WASTEWATER TREATMENT BY HYDRAULIC AUTOMATIC FLOATING MEDIA FILTER
Authors: Son Tran Thanh 
Published: April 2018

A pilot scale experiment was carried out in tertiary wastewater treatment using hydraulic automatic floating filter. The hydraulic automatic floating media filter has been working with 120 cm depth of polystyrene bed. Wastewater from secondary biological treatment of WWTP was treated in the pilot filter with filtration velocity of 4 m/h. Oxygen concentration was remained constantly at level 2.0 mg/l by using an ejector. Headloss development and evaluation of SS, COD, NH4+ removals during filtration were objectives of the study. The experiment results showed that concentrations of SS, COD and NH4+ in effluent wastewater were kept lower than 5 mg/l, 30 and 0.5 mg/l respectively for almost filtration cycle. Effects of treatment in SS, COD and NH4+ were 88.27 %, 68.54 % and 5.59 %, respectively.
A data-driven framework for remaining useful life estimation
Authors: Nguyen Hoa Dinh 
Published: April 2018

Remaining useful life (RUL) estimation is one of the most common tasks in the field of prognostics and structural health management. The aim of this research is to estimate the remaining useful life of an unspecified complex system using some data-driven approaches. The approaches are suitable for problems in which a data library of complete runs of a system is available. Given a non-complete run of the system, the RUL can be predicted using these approaches. Three main RUL prediction algorithms, which cover centralized data processing, decentralize data processing, and in-between, are introduced and evaluated using the data of PHM’08 Challenge Problem. The methods involve the use of some other data processing techniques including wavelets denoise and similarity search. Experiment results show that all of the approaches are effective in performing RUL prediction.
EVALUATION OF ANTIOXIDANT AND ANTI-AGING EFFICACIES OF COFFEA ROBUSTA EXTRACT ON HUMAN FIBROBLAST
Authors: Ngoc Hoi Nguyen Thi 
Published: April 2018

The extract of Coffea robusta was evaluated via the antioxidant and anti-aging efficacies on human dermal fibroblast. Coffea robusta green beans harvested in Buon Ma Thuot - Vietnam were roasted and extracted by hot water. The anti-oxidant activity of the extract was measured by the DHHP assay. Additionally, the extract was dosed to fibroblast and proteome analysis using 2-D was conducted to observe the changes of proteins involving in aging process. The results show that the extract is a strong anti-oxidant factor with low IC50 value for DPPH scavenging (33.2 mg/L), and significant up-regulation of 5 natural antioxidant enzymes (GPX2, GCLM, PRDX4, GSTA1 and NQO1), as well as down-regulation of 2 supporting-free-radicals proteins (NF-kB1 and TNF-alpha) of human fibroblast. Furthermore, the extract is a potential anti-aging factor with the down-regulation of 4 proteins related to the degradation of elastin and dermal extracellular matrix (CELA2B, CELA3A, CELA3B and MMP3).
EFFECT OF TEMPERATURE, WATER ACTIVITY AND CINNAMON ESSENTIAL OIL ON THE GROWTH OF ASPERGILLUS FLAVUS LA01 AND ASPERGILLUS NIGER LA04
Authors: Kim Lien Phan Thi 
Published: April 2018

The aim of the study was to evaluate the influence of temperature, water activity and cinnamon essential oil on the growth of Aspergillus flavus LA01 and Aspergillus niger LA04 and these factors were further optimized to inhibit their growth. Both strains were isolated by Potato Dextrose Agar medium (PDA) and identified by sequencing method from rice collected in Long An province. Evaluating these factors’ inhibition on the fungi growth was based on growth rate at the various points of water activity (aw) (v/v) such as 0.85, 0.90, 0.95, 0.99 and at 25 oC, 30 oC, 37 oC, 42 oC; at various concentrations of the oils 0 %, 1 %, 3 %, 5 %, 7.5 %, 10 % and 15 % at 30 oC incubated for 5 days - the disc diffusion method. The results showed that 30 oC and aw = 0.95 - 0.99 were optimum conditions for Aspergillus flavus LA01 and Aspergillus niger LA04 growth. However, at 42 oC, 37 oC and aw = 0.85 - 0.9 could control Aspergillus flavus LA01 and Aspergillus niger LA04 growth. At concentration of 10 - 15% cinnamon essential oils (EOs), 30 oC and aw = 0.9 - 0.95 could also inhibit them.
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.
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.
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.
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.
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.
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.
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.
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.