Laboratory Evaluation of Asphalt Mixtures Using Nano SIO2 to Improve Rutting Resistance

Van Bach Le,Van Phuc Le,Dong Nguyen 한국도로학회 2018 한국도로학회 학술대회 발표논문 초록집 Vol.2018 No.05

Rice husk, in large quantities, is released to the environment due to rice production in Vietnam. If this material can be utilized, it can solve not only the economic issues but also the environmental problems and sustainable development of the country. Laboratory evaluation of asphalt mixture using Nano silica made from rice husk to improve rutting resistance of asphalt mixtures was presented in this study. A 60/70 bitumen was used as control asphalt binder. The ratio of Nano SIO2 used in this study was 0.3%, 0,6%, 0,9%, 1,2%, and 1,5% by weight of powder. A dense gradation with nominal maximum aggregate size of 12.5mm was used for the asphalt mixtures. Marshall stability (MS) test and wheel tracking (WT) test were conducted to evaluate the rutting resistance of asphalt mixtures. It was found that the asphalt mixtures using 0.5%, 1.0%, and 1.5% Nano SIO2 have the rut depths of 5.35mm, 5.39mm, and 5.45mm, respectively, which is 30%, 31% and 29% lower than the control asphalt mixtures at 15,000 load cycles. Moreover, the static modulus of asphalt mixtures using 0.9% Nano SIO2 at 60oC is higher than the control mixtures. Based on the results of this study, it can be concluded that the addition of Nano SIO2 into asphalt mixtures can enhance the rutting performance of asphalt concrete under high temperatures significantly. It is noted that these conclusions were based on only on a limited number of samples and conditions. Further studies must be conducted to investigate the effect of Nano SIO2 on fatigue cracking and moisture damage of asphalt pavement in the field.

Effects of Media on the Callogenensis and Cell Mass Production in Cell Cultures of Panax vietnamensis

Hoang Van Luong,Nguyen Van Long,Vu Binh Duong,Nguyen Linh Toan,Nguyen Van Minh,Le Bach Quang,Nam Hyuck Kim,Sang Yo Byun 한국생물공학회 2009 KSBB Journal Vol.24 No.2

This study was initiated to investigate the impacts of media types and other components on the callogenensis and cell mass production of Panax vietnamensis in the first step of the cell biomass procedure. Four media were checked: Murashige-Skoog (MS), White, Gamborg and Nitch-All. All the four media were shown potential media for Panax vietnamensis callogenensis and cell mass production, in which the MS medium showed the best results: the successful callogenensis ratio and cell mass formation were 30% and 62,93 ± 3,63 mg (DW) respectively, the Nitch medium showed the lowest results: the successful callogenensis ratio and cell mass formation were 15% and 27,10 ± 2,24 mg (DW) respectively. The results showed that the MS medium is the most suitable medium for Panax vietnamensis callogenensis and cell mass production.

Effects of Media on the Callogenensis and Cell Mass Production in Cell Cultures of Panax vietnamensis

Luong, Hoang Van,Long, Nguyen Van,Duong, Vu Binh,Toan, Nguyen Linh,Minh, Nguyen Van,Quang, Le Bach,Kim, Nam-Hyuck,Byun, Sang-Yo The Korean Society for Biotechnology and Bioengine 2009 KSBB Journal Vol.7 No.4

This study was initiated to investigate the impacts of media types and other components on the callogenensis and cell mass production of Panax vietnamensis in the first step of the cell biomass procedure. Four media were checked: Murashige-Skoog (MS), White, Gamborg and Nitch-AII. All the four media were shown potential media for Panax vietnamensis callogenensis and cell mass production, in which the MS medium showed the best results: the successful callogenensis ratio and cell mass formation were 30% and 62,93 ${\pm}$ 3,63 mg (DW) respectively, the Nitch medium showed the lowest results: the successful callogenensis ratio and cell mass formation were 15% and 27,10 ${\pm}$ 2,24 mg (DW) respectively. The results showed that the MS medium is the most suitable medium for Panax vietnamensis callogenensis and cell mass production.

Effect of thermolysis condition on characteristics and nonsteroidal anti-inflammatory drugs (NSAIDs) absorbability of Fe-MIL-88B-derived mesoporous carbons

Van Tran, Thuan,Nguyen, Duyen Thi Cam,Le, Hanh T.N.,Bach, Long Giang,Vo, Dai-Viet N.,Dao, To-Uyen T.,Lim, Kwon Taek,Nguyen, Trinh Duy Elsevier 2019 Journal of environmental chemical engineering Vol.7 No.5

<P><B>Abstract</B></P> <P>Discharge of nonsteroidal anti-inflammatory drugs (NSAIDs) from wastewater has been increasingly alarmed, led to the advent of the treatment techniques. Among these methods, adsorption is regarded as a tunable and green approach with the utilization of mesoporous carbon (MC) as an efficient and recyclable adsorbent. Herein, we described the strategy for the synthesis of novel MC from Fe-MIL-88B as a self-sacrificial template. Three thermolysis temperatures (550, 750, and 950 °C) were investigated to compare the structural characteristics and absorbability towards selected NSAIDs compounds including diclofenac sodium (DCF), aspirin (APR), and ibuprofen (IBU). Effect of contact time (0–480 min), concentration (10–40 mg/L), pH (2–10), and MC dosage (0.1–0.5 g/L) was systematically studied. Kinetic and isotherm models were also used to find out the adsorption mechanism and behavior of NSAIDs pharmaceutical over MC materials. Proposed mechanism and recyclability test were rigorously studied to gain more insight into how the NSAIDs molecules adsorb on the MC materials and their potential towards drug treatment.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Effect of thermolysis temperature on characteristics and absorbability towards anti-inflammatory drugs was conducted. </LI> <LI> Kinetic, isotherm, and recyclability experiments were systematically studied. </LI> <LI> Adsorption mechanisms including H-bond, π–π interaction, metal–oxygen bridging, and electrostatic attraction were rigorously proposed. </LI> <LI> Outstanding adsorption capacity (∼144 mg/g), and excellent reusability were monitored with Fe-MIL-88B-derived mesoporous carbon. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

A new hybrid sewage treatment system combining a rolled pipe system and membrane bioreactor to improve the biological nitrogen removal efficiency: A pilot study

Bach, Quang-Vu,Le, Van Tam,Yoon, Yong Soo,Bui, Xuan Thanh,Chung, Woojin,Chang, Soon Woong,Ngo, Huu Hao,Guo, Wenshan,Nguyen, Dinh Duc Elsevier 2018 Journal of Cleaner Production Vol.178 No.-

<P><B>Abstract</B></P> <P>A new hybrid pilot plant configuration based on a modularized rolled pipe system (RPS) combined with a submerged flat sheet membrane bioreactor (MBR) was investigated to enhance the sewage treatment and membrane performance. The system was operated under actual conditions for more than four months, that is, at a constant flow rate of 30 m³/d and with two internal recycling ratios. The results indicate that the hybrid system produces an excellent effluent quality and considerably mitigated membrane fouling. The average concentrations of SS, COD, TN, NH<SUB>4</SUB> <SUP>+</SUP>-N, NO<SUB>3</SUB> <SUP>−</SUP>-N, and PO<SUB>4</SUB> <SUP>3-</SUP>-P remained below 2.81, 8.29, 8.77, 0.15, 8.17, and 1.49 mg/L, respectively. It was estimated that the periodic chemical cleaning of the membrane could be extended to approximately six months. The MBR and RPS can virtually complete nitrification and denitrification, respectively. The highest average denitrification rate of the RPS is 116.95 mg NO<SUB>3</SUB>-N/(g MLVSS d), with a hydraulic retention time of 1.05 h. Therefore, the RPS–MBR hybrid system has potential to improve the sewage treatability. The emerging RPS technique can obtain high rates of denitrification coupled with a compact design, ease of installation, and small footprint.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A new hybrid sewage treatment system was explored. </LI> <LI> Excellent denitrification is achieved with the novel rolled pipe system. </LI> <LI> High rates of simultaneous nitrification and denitrification are obtained. </LI> <LI> The hybrid system performs well in removing organic and nitrogen compounds. </LI> <LI> The membrane fouling rate of the hybrid system is significantly low. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Controllable synthesis of MoS₂/graphene low-dimensional nanocomposites and their electrical properties

Long, Le Ngoc,Thi, Pham Tan,Trung Kien, Pham,Trung, Pham Thanh,Ohtani, Masataka,Kumabe, Yoshitaka,Tanaka, Hirofumi,Ueda, Shigenori,Lee, Hyoyoung,Thang, Phan Bach,Khai, Tran Van Elsevier 2020 APPLIED SURFACE SCIENCE - Vol.504 No.-

<P><B>Abstract</B></P> <P>In this study, a novel hydrothermal route has been developed for the synthesis of MoS<SUB>2</SUB>/graphene composite with controllable structures, in which ammonium molybdatetetrahydrate, as-prepared graphene oxide (GO), and thioacetamide were used as staring materials. Effects of Mo<SUP>4+</SUP>-to-C precursor ratios and crystalline time on the structures, components and morphologies of MoS<SUB>2</SUB>/graphene were investigated. MoS<SUB>2</SUB>/graphene samples were characterized using XRD, FESEM, HRTEM, FTIR, Raman spectroscopy, HAADF-STEM/EDS, HXPES and electrical measurements. The results show that petal-like MoS<SUB>2</SUB> nanostructures with ultrathin petals (~1–10 layers) and coexistence of 1T- and 2H-MoS<SUB>2</SUB> phases can be synthesized on graphene surface in a short time (~2 h). Comparison of crystallization conditions, we found that the crystallization time had a significant effect on the size of the MoS<SUB>2</SUB> nanopetals. The shorter the reaction time is, the thinner the petal-like MoS<SUB>2</SUB> nanoscale is. On the other hand, by adjusting the ratios of Mo<SUP>4+</SUP>to C (denoted as: MoS<SUB>2</SUB>/C (1:2), MoS<SUB>2</SUB>/C (3:2), MoS<SUB>2</SUB>/C (2.5:1) and MoS<SUB>2</SUB>/C (3:1)), different MoS<SUB>2</SUB>/graphene architectures including “sandwich-liked”, “layer–by–layer” and “anchored” can be obtained. On the basis of these results, a possible growth mechanism of MoS<SUB>2</SUB>nanopetals on GO was proposed. Interestingly, the as-synthesized material depicts its memristive behavior through the Volt-Ampere characteristics, suggesting a potential application in logic memory devices.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A novel hydrothermal route has been developed for the synthesis of MoS<SUB>2</SUB>/graphene composite with controllable structures. </LI> <LI> The effects of Mo<SUP>4+</SUP>-to-C precursor ratios and crystalline time on properties of MoS<SUB>2</SUB>/graphene were investigated by FESEM, HRTEM, XRD, FTIR, Raman spectroscopy, HAADF-STEM/EDS and HXPES. </LI> <LI> The memristive properties of the MoS<SUB>2</SUB>/graphenenanocomposite were presented. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Unipolar Resistance Switching Characteristics in a Thick ZnO/Cu/ZnO Multilayer Structure

Tran Le,Hoang Cao Son Tran,Van Hieu Le,Tuan Tran,Cao Vinh Tran,Thanh Tan Vo,Mau Chien Dang,김상섭,이재찬,Bach Thang Phan 한국물리학회 2012 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.60 No.7

The resistance switching mechanism and the electrical conduction of thick Cu/ZnO/Cu/ZnO/Cu structures were investigated for various ZnO thicknesses (40, 80, 160, and 320 nm) when the thickness of the middle Cu layer was 2 nm. The ZnO films had a microstructure with columnar grains normal to the substrate. The switching voltages (VSET and VRESET) varied with the thickness of the ZnO layer. A symmetric electrode structure exhibited a unipolar resistance switching. The electrical transport of both high-resistance state (HRS) and low-resistance state (LRS) was Ohmic conduction, and the resistance switching mechanism was driven by the formation and the rupture of Cu conducting paths.

Clerodendrum ervatamioides (Lamiaceae): A new record to the flora of Vietnam

Heyjoong KIM,Do Van Hai,Tran Duc THIEN,Tran The Bach,Bui Hong Quang,Duong Thi HOAN,Le Ngoc HAN,Tran Duc BINH,Ritesh Kumar Choudhary,이중구 한국식물분류학회 2022 식물 분류학회지 Vol.52 No.4

Clerodendrum ervatamioides C. Y. Wu was described in 1977 with its type locality in Yunnan, China. During our floristic investigation in the Muong Nhe Nature Reserve of Vietnam of Dien Bien province and in the Muong Te district of the Lai Chau province, we collected several specimens of Clerodendrum ervatamioides, marking the first record of its occurrence in Vietnam. In this paper, details of the morphological features, distribution, ecology, photo plates, and a table comparing the morphological features with its ally Clerodendrum garrettianum Craib are provided.

Control of morphology and Orientation of Electrochemically Grown ZnO Nanorods

Tran Hoang Cao Son,Le Khac Top,Nguyen Thi Dong Tri,Ha Thuc Chi Nhan,Lam Quang Vinh,Bach Thang Phan,김상섭,Le Van Hieu 대한금속·재료학회 2014 METALS AND MATERIALS International Vol.20 No.2

We report the direct electrochemical deposition of ZnO nanorods on an indium tin oxide substrate. Themorphology and orientation of the grown ZnO nanorods were investigated as functions of the currentdensity. It is likely that the concentrations of OH- and Zn2+ ions, which could be controlled by varying thecurrent density, determine the shape and alignment of the ZnO nanorods. The nanorods were tilted, hexagonal,and prismatic at a low current density (0.1 mA/cm2) and vertically aligned and obelisk-shaped at highcurrent densities (greater than 0.6 mA/cm2). By using the low and high current densities sequentially in atwo-step growth process, vertically aligned, hexagonal, and prismatic ZnO nanorods could be grownsuccessfully. The underlying mechanism responsible for the growth of the ZnO nanorods is also discussed.

Argyreia gyrobracteata Traiperm & Chitchak (Convolvulaceae): A new record to the flora of Vietnam

Binh Duc TRAN,Bach The TRAN,Do Van Hai,Quang Hong BUI,Son Hoang DOAN,Han Ngoc LE,Thuy Thu NGUYEN,엄상미 한국식물분류학회 2020 식물 분류학회지 Vol.50 No.3

Argyreia gyrobracteata Traiperm & Chitchak (Convolvulaceae) is newly recorded in Vietnam. It is similar to A. mekongensis Gagnep & Courch in having a white campanulate corolla but differs from that species by having whitish surface of the abaxial leaf, narrowly lanceolate or linear-oblong, curly, rolled up the bract with a longer length of the petiole and a shorter pedicel. It was previously known only in Thailand, but was recently found in Lam Dong Province, Vietnam, for the first time. The present study provides a detailed description, colorful photos and the distribution of the species. Furthermore, a comparison of the diagnostic characters between this species and a related species in Vietnam, A. mekongensis Gagnep & Courch, is provided.