The Role of Zn Doping on the Catalytic Activity of the Nanoparticle Perovskite La0.7Sr0.3MnO3

Tran Thi Minh Nguyet,Nguyen Quang Huan,Tran Que Chi,Do The Chan,Nguyen Doan Thai,Nguyen Cong Trang,Luu Tien Hung,Le Van Tiep,Nguyen Van Qui 한국물리학회 2008 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.52 No.5

The nanometer complex oxide La0:7Sr0.3Mn0.6Zn0.₄O₃ was prepared by using a Sol-Gel method with citric acid as a ligand. The in uence of Zn doping of La0.7Sr0.₃MnO₃ on the structure, the morphology, the surface properties and on the catalytic activity of material was studied by using X-ray diraction (XRD), transmission electron microscopy (TEM), a high-resolution images and selected area electron diraction (SAED), physical adsorption and temperature programmed surface reaction (TPSR) methods. The results showed that perovskite La0:7Sr0:3Mn0:6. Zn0.₄O₃ could well catalyse propene oxidation in the temperature range 190 { 280 ℃, which was reduced to 100 { 120 ℃ for catalyst La1-χSrχMnO₃ The nanometer complex oxide La0:7Sr0.3Mn0.6Zn0.₄O₃ was prepared by using a Sol-Gel method with citric acid as a ligand. The in uence of Zn doping of La0.7Sr0.₃MnO₃ on the structure, the morphology, the surface properties and on the catalytic activity of material was studied by using X-ray diraction (XRD), transmission electron microscopy (TEM), a high-resolution images and selected area electron diraction (SAED), physical adsorption and temperature programmed surface reaction (TPSR) methods. The results showed that perovskite La0:7Sr0:3Mn0:6. Zn0.₄O₃ could well catalyse propene oxidation in the temperature range 190 { 280 ℃, which was reduced to 100 { 120 ℃ for catalyst La1-χSrχMnO₃

Microwave-assisted synthesis of MgFe2O4-decorated UiO-66(Zr)-NH2 compositesfor collaborative adsorption and photocatalytic degradation of tetracycline

The Ky Vo,Minh Tien Nguyen,Van Cuong Nguyen,김진수 한국화학공학회 2022 Korean Journal of Chemical Engineering Vol.39 No.9

MgFe2O4-decorated UiO-66(Zr)-NH2 composites (MFO@UN) with different blending ratios were efficientlyprepared by microwave-assisted synthesis. The results indicate that the hybrid composite exhibits high surfacearea and magnetic properties. Moreover, combining ferrite into the UiO-66(Zr)-NH2 framework produces a heterojunctionstructure and an interfacial interaction that improves the composite's visible-light absorption. Tetracyclineremoval experiments show that the MFO@UN composites exhibit excellent photodegradation performance comparedwith the pure ferrite and MOF. The optimal 1.5MFO@UN catalyst (molar Zr4+/MgFe2O4=1.5) exhibits the highestremoval efficiency of approximately ca. ~92% after 90 min of pre-adsorption and 160min of visible-light illumination.The photocatalytic mechanism investigation reveals that photo-induced holes (h+) and ·OH radicals predominantlygovern the photodegradation process. Notably, the separation and immigration of the photo-induced holes and electronsimprove due to the heterojunction structures that form between the two semiconductors. In addition, the prepared catalystsare highly recoverable and renewable. These findings suggest that the microwave-derived MgFe2O4@UiO-66(Zr)-NH2 catalyst may be a promising candidate for treating organic contaminants in wastewater.

Selective Harmonic Elimination for Cascaded Multilevel Inverters Using Grey Wolf Optimizer Algorithm

Phan Quoc Dzung,Nguyen The Tien,Nguyen Dinh Tuyen,Hong-Hee Lee 전력전자학회 2015 ICPE(ISPE)논문집 Vol.2015 No.6

In this paper, Grey Wolf Optimizer (GWO) algorithm is applied to determine optimum switching angles for cascaded multilevel inverter of eliminating some high order harmonics while maintaining the required fundamental voltage. As case study in this paper, 11-level and 15-level inverter are considered and the optimum switching angles are calculated off-line to eliminate the 5th, 7th, 11th, 13th harmonics for the 11-level as well as 17th, 19th harmonics for 15-level. The total harmonic distortion is used to estimate the quality of output voltages. The results are shown graphically for better understanding, the mathematical formulations and simulation results will be presented.

Evaluation of Pt-based alloy/graphene nanohybrid electrocatalysts for triiodide reduction in photovoltaics

Dao, Van-Duong,Larina, Liudmila L.,Tran, Quoc Chinh,Bui, Van-Tien,Nguyen, Van-Toan,Pham, Thanh-Dong,Mohamed, Ibrahim M.A.,Barakat, Nasser A.M.,Huy, Bui The,Choi, Ho-Suk Elsevier 2017 Carbon Vol.116 No.-

<P>This work focuses on systematic studies of dissolution engineering for Pt0.9M0.1/graphene(M = Au, Co, Cu, Fe, Mo, Ni, Pd, Ru, and Sn) counter electrodes (CEs). The developed nanohybrid materials exhibit higher catalytic activity and electrical conductivity compared with those of Pt/graphene CEs. The results also indicate the improved stability of the developed CEs in iodide electrolyte. Furthermore, the trend in the variation of the reactivity of the PtM alloys agrees well with the concept of density functional theory (one-electron description). An enhancement in the catalytic activity of the developed nanohybrids results from the electronic effect that originates from an upward shift of the platinum d-band to the Fermi energy level upon alloying. Thus, the Pt(0.9)M(0.1)graphene nanohybrids are cost-effective alternative CE materials to the expensive Pt. The obtained results provide a foundation for enhancing the catalytic activities of CEs for dye-sensitized solar cells (DSCs). The implementation of the Pt0.9M0.1/graphene nanohybrids offers significant potential for increasing the efficiency of DSCs. (C) 2017 Elsevier Ltd. All rights reserved.</P>

Novel 3,4-dihydro-4-oxoquinazoline-based acetohydrazides: Design, synthesis and evaluation of antitumor cytotoxicity and caspase activation activity

Huan, Le Cong,Tran, Phuong-Thao,Phuong, Cao Viet,Duc, Phan Huy,Anh, Duong Tien,Hai, Pham The,Huong, Le Thi Thu,Thuan, Nguyen Thi,Lee, Hye Jin,Park, Eun Jae,Kang, Jong Soon,Linh, Nguyen Phuong,Hieu, Tr Elsevier 2019 Bioorganic chemistry Vol.92 No.-

<P><B>Abstract</B></P> <P>In search for novel small molecules with antitumor cytotoxicity via activating procaspase-3, we have designed and synthesized three series of novel (E)-<I>N</I>′-benzylidene-4-oxoquinazolin-3(4<I>H</I>)-yl)acetohydrazides (<B>5a-j, 6a-h,</B> and <B>7a-h)</B>. On the phenyl ring ò the benzylidene part, three different substituents, including 2-OH-4-OCH<SUB>3</SUB>, 4-OCH<SUB>3</SUB>, and 4-N(CH<SUB>3</SUB>)<SUB>2</SUB>, were introduced, respectively. Biological evaluation showed that the acetohydrazides in series <B>5a-j</B>, in which the phenyl ring of the benzylidene part was substituted by 2-OH-4-OCH<SUB>3</SUB> substituent, exhibited potent cytotoxicity against three human cancer cell lines (SW620, colon; PC-3, prostate; NCI-H23, lung). Most of the compounds, in this series, especially compounds <B>5c, 5b</B> and <B>5h,</B> also significantly activated caspase-3 activity. Among these, compound <B>5c</B> displayed 1.61-fold more potent than PAC-1 as caspase-3 activator. Cell cycle analysis showed that compounds <B>5b</B>, <B>5c</B>, and <B>5h</B> significantly arrested the cell cycle in G1 phase. Further apoptotic studies also demonstrated compounds <B>5b</B>, <B>5c</B>, and <B>5h</B> as strong apoptotic cell death inducers. The docking simulation studies showed that these compounds could activate procaspase <I>via</I> chelating Zn<SUP>2+</SUP> ion bound to the allosteric site of the zymogen.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Novel (<I>E</I>)-<I>N</I>′-benzylidene-2-(4-oxoquinazolin-<I>3(4H)-yl</I>)acetohydrazides were synthesized. </LI> <LI> The acetohydrazides <B>5a-i</B> exhibited potent cytotoxicity against three human cancer cell lines. </LI> <LI> A number of cytotoxic compounds exhibited good caspase activation activity. </LI> <LI> The cytotoxic compounds were shown to arrest cells at G1 phase. </LI> <LI> The cytotoxic compounds were shown as strong apoptotic inducers. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Hanoi, Socson,Namson 매립지에서 발생하는 침출수 처리에 관한 연구

( Cao The Ha ),( Nguyen Tien Thang ) 한국폐기물자원순환학회 2002 APLAS Vol.2002 No.2

매립지 침출수는 two-step 생물학적처리방법에 의해서 처리되고 난 뒤 페톤 산화에 의한 고도 산화 혹은 역삼투압 여과를 통해서 처리되어졌다. 실험 적으로 생물학적 처리만으로는 COD £ 100; TKN £ 60 mg/L에 대한 베트남 산업 폐수 방류 기준에 적합하지 않았다. PAC 흡착과 함께 펜톤산화의 조합의 적용은 COD와 색도의 문제를 해결할 수 있다. PAC적용은 참고문헌의 데이터와 비교시 펜톤산화의 COD 제거효율 2배 이상으로 증가되었다. 질소 함량의 경우, 대부분 암모니아성-질소는 조금만 변화가 일어났다. 생물학적으로 처리된 침출수는 역삼투압 기술에 의해서 여과되어졌다. COD, 색도와 TDS의 제거는 우수 하였으나, 질소화합물의 제거는 여전히 불충분하였다. Vietnamese standards 5945-1995 B 기준에 만족시키기 위한 최선의 침출수 처리 방법은 BOD 제거와, 질산화-탈질화 과정 혹은 장기 산화지를 포함하는 생물학적처리 다음에 고급산화- 흡착기술 혹은 연속 급속 모래여과법-역삼투압 여과법 둘 중에 하나를 적용하는 것이다. Landfill leachate has been treated by mean of two-step biological process following by either advanced oxidation by Fenton reagent/reaction (FR) or reverse osmosis filtration. It was experimentally proved that biologically treated landfill leachate itself can not meet demands of existing Vietnamese standards for industrial liquid discharge regarding to COD, N-content values (COD £ 100; TKN £ 60 mg/L). Application of Fenton reagent in combination with PAC adsorption can solve problem of COD and color. The application of PAC can increase COD removal efficiency of a unit H2O2 applied as much as twice or higher in comparison with reference reported data. In this case N-content, mostly N-ammonia, changed insignificantly. Biologically treated leachate can also be filtered by RO technique. COD, color and TDS removal were excellent, but N-compounds removal was still poor. The best way to treat leachate to meet Vietnamese standards 5945-1995 B is to apply biological treatments including BOD removal, nitrification-denitrification steps or long-term pond system following by either advanced oxidation-adsorption technique or with the sequence of rapid sand filtration- reverse osmosis filtration.

STUDY ON TREATMENT OF THE LEACHATE FROM LANDFILL SITE AT NAMSON, SOCSON, HANOI

( Cao The Ha ),( Nguyen Tien Thang ) 한국폐기물자원순환학회 2002 APLAS Vol.2002 No.1

Landfill leachate has been treated by mean of two-step biological process following by either advanced oxidation by Fenton reagent/reaction (FR) or reverse osmosis filtration. It was experimentally proved that biologically treated landfill leachate itself can not meet demands of existing Vietnamese standards for industrial liquid discharge regarding to COD, N-content values (COD ≤ 100; TKN ≤ 60 mg/L). Application of Fenton reagent in combination with PAC adsorption can solve problem of COD and color. The application of PAC can increase COD removal efficiency of a unit H₂O₂ applied as much as twice or higher in comparison with reference reported data. In this case N-content, mostly N-ammonia, changed insignificantly. Biologically treated leachate can also be filtered by RO technique. COD, color and TDS removal were excellent, but N-compounds removal was still poor. The best way to treat leachate to meet Vietnamese standards 5945-1995 B is to apply biological treatments including BOD removal, nitrification-denitrification steps or long-term pond system following by either advanced oxidation-adsorption technique or with the sequence of rapid sand filtration-reverse osmosis filtration.

Jasminum albicalyx Kobuski (Oleaceae): a new record from Vietnam

Bui Hong Quang,Ritesh Kumar Choudhary,Tran The Bach,Vu Tien Chinh,Nguyen Sinh Khang,이창영,이중구 한국식물분류학회 2014 식물 분류학회지 Vol.44 No.3

We report a new record of Jasminum albicalyx Kobuski in Vietnam. The plant differs from J. pedunculatum Gagnep., a closely related taxon, by foliar and floral characters such as less number of lateral veins, presence of domatia at vein axils on the abaxial surface of leaf, smaller bracts, white calyx having more number of lobes and less number of lobes in corolla. Morphological description, line drawing and color photographs are provided in addition to the species key of allied species of Jasminum albicalyx in Vietnam.

Design, synthesis and evaluation of novel <i>N</i>-hydroxybenzamides/<i>N</i>-hydroxypropenamides incorporating quinazolin-4(3<i>H</i>)-ones as histone deacetylase inhibitors and antitumor agents

Hieu, Doan Thanh,Anh, Duong Tien,Tuan, Nguyen Minh,Hai, Pham-The,Huong, Le-Thi-Thu,Kim, Jisung,Kang, Jong Soon,Vu, Tran Khac,Dung, Phan Thi Phuong,Han, Sang-Bae,Nam, Nguyen-Hai,Hoa, Nguyen-Dang Elsevier 2018 Bioorganic chemistry Vol.76 No.-

<P><B>Abstract</B></P> <P>In our search for novel small molecules targeting histone deacetylases, we have designed and synthesized several series of novel <I>N</I>-hydroxybenzamides/<I>N</I>-hydroxypropenamides incorporating quinazolin-4(3<I>H</I>)-ones (<B>4a-h</B>, <B>8a-d, 10a-d)</B>. Biological evaluation showed that these hydroxamic acids were generally cytotoxic against three human cancer cell lines (SW620, colon; <I>PC</I>-3, prostate; NCI-H23, lung cancer). It was found that the <I>N</I>-hydroxypropenamides (<B>10a-d)</B> were the most potent, both in term of HDAC inhibition and cytotoxicity. Several compounds, e.g. <B>4e</B>, <B>8b-c</B>, and <B>10a-c</B>, displayed up to 4-fold more potent than SAHA (suberoylanilide hydroxamic acid, vorinostat) in term of cytotoxicity. These compounds also comparably inhibited HDACs with IC<SUB>50</SUB> values in sub-micromolar range. Docking experiments on HDAC2 isozyme revealed some important features contributing to the inhibitory activity of synthesized compounds, especially for propenamide analogues. Importantly, the free binding energy computed was found to have high quantitative correlation (<I>R</I> <SUP>2</SUP> ∼ 95%) with experimental results.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Novel quinazolin-4(3H)-one-based <I>N</I>-hydroxybenzamides/<I>N</I>-hydroxypropenamides were synthesized. </LI> <LI> The <I>N</I>-hydroxybenzamides/<I>N</I>-hydroxypropenamides exhibited potent HDAC inhibition. </LI> <LI> The <I>N</I>-hydroxybenzamides/<I>N</I>-hydroxypropenamides exhibited good cytotoxicity. </LI> <LI> Docking studies and ADMET estimation were carried out. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>Two series of novel, simple <I>N</I>-hydroxybenzamides/<I>N</I>-hydroxypropenamides incorporating quinolin-4(3H)-one (<B>4a-h</B>, <B>8a-d, 10a-d</B>) were designed and synthesized. Biological evaluation showed that these benzamides/propenamides potently inhibited HDAC with IC<SUB>50</SUB> values in sub-micromolar range. A number of compounds also exhibited cytotoxicity up to 4-fold more potent than SAHA, a positive control.</P> <P>[DISPLAY OMISSION]</P>

A Single-Phase Transformerless Buck-Boost Inverter for Standalone and Grid-Tied Applications with Reduced Magnetic Volume

Fazal Akbar,Honnyong Cha,Seunghoon Lee,Tien-The Nguyen 전력전자학회 2019 ICPE(ISPE)논문집 Vol.2019 No.5

In this paper, a new single-phase single-stage transformerless inverter is proposed for grid-tied and standalone applications. The proposed inverter has low leakage current and is capable to perform both buck and boost functions. Further, as compared to the conventional state of art buck-boost inverters, it can achieve high power density because the magnetic volume is reduced significantly. High power conversion efficiency with reduced EMI concerns can be realized because only one switch operates at high frequency. Moreover, there is no need for generating high frequency deadtime because all the remaining switches operate at line frequency. In order to verify the proposed topology, a laboratory prototype is designed for 500 W and the experimental results are provided as well.