Buddhist Practices during Medieval Nepal

Bhadra Ratna Bajracharya 회당학회 2010 회당학보 Vol.15 No.-

불교의 가르침이 전해질 때 그의 문화도 함께 전해진다는 것이 공통적인 믿음이다. 역사적으로 봤을 때도 불교를 종교로만 받아들이지 않고 문명과 문화로 받아들인 것으로 보인다. 그래서 불교는 새로운 전통으로서 아시아 각국에서 자기만의 다양한 색깔과 자연에 따라 사회의 격변과 수정 속에 조금씩 변화해 왔다. 그러나 불교전통은 아직도 본래 그대로 부처님의 가르침과 기본적인 것을 지켜오고 있다. 본 논문에서는 특히 중세 네팔의 불교 수행을 소개하고자 한다.

Adsorptive removal of wide range of pharmaceuticals and personal care products from water using bio-MOF-1 derived porous carbon

Bhadra, Biswa Nath,Jhung, Sung Hwa Elsevier 2018 Microporous and mesoporous materials Vol.270 No.-

<P><B>Abstract</B></P> <P>Bio-MOF-1 was pyrolyzed at 1000 °C to obtain highly porous carbon containing oxygen and nitrogen. The bio-MOF-derived carbons (BMDCs) were firstly applied in the adsorptive removal of four pharmaceuticals and personal care products (PPCPs), with a wide range of acidities or basicities, from water. BMDC-12 h, obtained by pyrolysis for 12 h, was very competitive in the adsorption of PPCPs, in terms of both adsorption rate and adsorbed quantity. More importantly, carbon showed the highest adsorption capacities for both basic atenolol (ATNL; 552 mg/g) and acidic clofibric acid (CLFA; 540 mg/g) among all the adsorbents reported so far. The recyclability of BMDC-12 h in adsorption was also confirmed (after solvent washing) by both adsorption and characterization (by nitrogen adsorption and FTIR analyses). The plausible adsorption mechanism was also suggested based on the effect of solution pH on the adsorbed amounts of PPCPs. Electrostatic interaction was the primary mechanism for the adsorption of ATNL. However, CLFA adsorption could be explained mainly by H-bonding, where CLFA was the acceptor for hydrogen donated from BMDC-12 h. BMDC-12 h was suggested as a promising adsorbent for the removal of a wide range of PPCPs from water, based on the remarkably high adsorption capacity, rapid adsorption, and stable reusability.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Porous carbon derived from Bio-MOF-1 was applied in removal of PPCPs. </LI> <LI> Bio-MOF-1-derived carbon showed the highest atenolol and clofibric acid adsorption. </LI> <LI> The principal adsorption mechanisms could be defined for each adsorbate. </LI> <LI> The adsorbent showed perfect reusability for successive adsorptions in water. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Oxidative desulfurization and denitrogenation of fuels using metal-organic framework-based/-derived catalysts

Bhadra, Biswa Nath,Jhung, Sung Hwa Elsevier 2019 Applied Catalysis B Vol.259 No.-

<P><B>Abstract</B></P> <P>Removal of sulfur- and nitrogen-containing compounds (SCCs and NCCs) from commercial fuel is very important since those impurities can cause various problems including catalyst deactivation and acid rain. Because of the limitations of the conventional refinery methods, development of a new method such as oxidative desulfurization (ODS) is highly desirable. Metal-organic frameworks (MOFs)-based and MOF-derived nanohybrid materials were suggested as a good catalyst for ODS of fuels. Moreover, removal of NCCs via oxidation with MOF-derived catalyst was also reported even though the technique is just emerging. Therefore, it is required to analyze the reported results; and more importantly to suggest a new research direction; and finally, to estimate the possibility of new desulfurization/denitrogenation technology that might replace/compensate studied technologies. This review might be quite beneficial not only to accumulate or understand the reported results but also to develop new efficient catalysts for the probable commercialization of the ODS/ODN technology.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Oxidative purification of fuel with MOFs or MOF-derived materials was summarized. </LI> <LI> Oxidative catalysis to remove S- and N-compounds from fuel was analyzed. </LI> <LI> The mechanism and limit/possibility of the catalysis with those catalysts were summarized. </LI> <LI> The prospect and future research direction on the field were summarized/suggested. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Liquid-Phase Adsorption of Aromatics over a Metal-Organic Framework and Activated Carbon: Effects of Hydrophobicity/Hydrophilicity of Adsorbents and Solvent Polarity

Bhadra, Biswa Nath,Cho, Kyung Ho,Khan, Nazmul Abedin,Hong, Do-Young,Jhung, Sung Hwa American Chemical Society 2015 The Journal of Physical Chemistry Part C Vol.119 No.47

Adsorption of diclofenac sodium from water using oxidized activated carbon

Bhadra, B.N.,Seo, P.W.,Jhung, S.H. Elsevier 2016 CHEMICAL ENGINEERING JOURNAL -LAUSANNE- Vol.301 No.-

Adsorption of diclofenac sodium (DCF) from aqueous solutions using surface-modified/oxidized activated carbons (OACs) was investigated and compared with that over virgin activated carbon (AC). The obtained results showed a remarkable increase (~6 times) in DCF removal over oxidized AC compared to that over a commercial, unmodified AC, despite the decreased surface area in the OAC. The large increase in DCF removal may be due to the presence of acidic surface functional groups, which are created on the AC surface upon oxidation. To understand the role of these acidic functional groups on the increased adsorption capacity (q<SUB>t</SUB>), the concentration of acidic groups was determined using Boehm titration after oxidation with different quantities of oxidizing agent. The adsorption capacity of the OAC prepared by treatment with 2.0M ammonium persulfate solution (OAC (2.0)) was the highest of the prepared adsorbents. Therefore, OAC (2.0) was studied in detail by characterizing the material and investigating the adsorption performances. The effect of pH on the surface charge (zeta potential) and DCF adsorption capacity of OAC (2.0) was investigated to lead to the mechanism of DCF adsorption such as hydrogen bonding and electrostatic interactions. Additionally, the OAC can be recycled for adsorptive removal of DCF by simple solvent washing. Therefore, the OAC was found to be a promising adsorbent for the removal of DCF from contaminated water.

Synthesis of higher soluble nanostructured polyaniline by vapor-phase polymerization and determination of its crystal structure

Bhadra, Sambhu,Lee, Joong Hee Wiley Subscription Services, Inc., A Wiley Company 2009 Journal of applied polymer science Vol.114 No.1

<P>Higher soluble nanostructured polyaniline was prepared by vapor-phase polymerization after passing aniline vapor through an aqueous acidic solution of ammonium persulfate (PANI-V). Polyaniline was also synthesized by the conventional oxidative polymerization method (PANI-C) in an aqueous medium for the comparison of its properties with PANI-V. PANI-V exhibited lower conductivity but higher hydrophilicity and higher solubility (2–3 times) in different solvents, such as tetrahydrofuran, N-methyl-2-pyrrolidone, dimethylsulfoxide, N,N-dimethyl formamide, and m-cresol at room temperature compared with that of PANI-C. The thermal stability of PANI-V was higher than that of PANI-C. In-depth investigations of the crystal structures of PANI-C and PANI-V were performed through powder X-ray diffraction analysis. The PANI-V showed a less ordered structure with a lower crystallinity and crystallite size and with a higher d-spacing and interchain separation compared with PANI-C. The unit cell volume of PANI-V was significantly higher with a greater number of atoms in the unit cell than that of PANI-C. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009</P>

Adsorptive removal of aromatic hydrocarbons from water over metal azolate framework-6-derived carbons

Bhadra, Biswa Nath,Song, Ji Yoon,Lee, Su-Kyung,Hwang, Young Kyu,Jhung, Sung Hwa Elsevier 2018 Journal of hazardous materials Vol.344 No.-

<P><B>Abstract</B></P> <P>Metal azolate framework-6 (MAF-6) was pyrolyzed at 1000°C to yield MOF-derived carbons (MCs). The obtained MCs were used to eliminate aromatic hydrocarbons, including polyaromatic hydrocarbons (PAHs; e.g., naphthalene (NAP), anthracene (ATC), and pyrene (PRN)) and benzene (BZ) from water via adsorption. The adsorption results over the MCs were compared with that of pristine MAF-6 and commercial activated carbon (AC). MC obtained after 24h (MC-24) exhibited a remarkable adsorption efficiency compared to that of the other MCs (obtained after different durations), MAF-6, and AC. For example, MC-24 led to adsorptions of NAP around 17 and 2.5 times those of pristine MAF-6 and AC, respectively. Or, the maximum adsorption capacities (<I>Q</I> <SUB>0</SUB>) of MAF-6, AC and MC-24 for NAP were 14, 104 and 237mg/g, respectively. Moreover, <I>Q</I> <SUB>0</SUB> values of MC-24 for ATC and PRN were also very high of 284 and 307mg/g, respectively. Based on the properties of PAHs and the hydrophobicity of MC-24, hydrophobic interaction was suggested as the main mechanism for the adsorption of PAHs and BZ. In addition, MC-24 can be recycled by washing with acetone with little loss in performance. Therefore, MC-24 is recommended as a competitive adsorbent for aromatic hydrocarbon removal from water.</P> <P><B>Highlights</B></P> <P> <UL> <LI> MOF-derived carbons (MCs) were obtained by pyrolysis of MAF-6 in wide conditions. </LI> <LI> MCs showed highly effective adsorption of aromatic hydrocarbons from water. </LI> <LI> The remarkable adsorptions were because of high porosity/hydrophobicity of MCs. </LI> <LI> Hydrophobic interaction was suggested as the main mechanism for the adsorption. </LI> <LI> The new adsorbents can be regenerated by simple acetone washing. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

TiO₂-Containing Carbon Derived from a Metal–Organic Framework Composite: A Highly Active Catalyst for Oxidative Desulfurization

Bhadra, Biswa Nath,Song, Ji Yoon,Khan, Nazmul Abedin,Jhung, Sung Hwa American Chemical Society 2017 ACS APPLIED MATERIALS & INTERFACES Vol.9 No.36

<P>A new metal organic framework (MOP) composite consisting of Ti- and Zn-based MOFs (ZIF-8(x) @H2N-MIL-125; in brief, ZIF(x)@MOF) was designed and synthesized. The pristine MOF [H2N-MIL-125 (MOF)]- and an MOF-composite [ZIF(30)@MOF]-derived mesoporous carbons consisting of TiO2 nanoparticles were prepared by pyrolysis (named MDC-P and MDC-C, respectively). MDC-C showed a higher surface area, larger pore sizes, and larger mesopore volumes than MD C-P. In addition, the TiO2 nanoparticles on MDC-C have more uniform shapes and sizes and are smaller than those of MDC-P. The obtained MDC-C and MDC-P [together with MOF, ZIF(30)@MOF, pure/nanocrystalline TiO2, and activated carbon] were applied in the oxidative desulfurization reaction of dibenzothiophene in a model fuel. The MDC-C, even with a lower TiO2 content than that of MDC-P, showed an outstanding catalytic performance, especially with a very low catalyst dose (i.e., a very high quantity of dibenzothiophene was converted per unit weight of the catalyst), fast kinetics (similar to 3 times faster than that for MDC-P), and a low activation energy (lower than that for any reported catalyst) for the oxidation of dibenzothiophene. The large mesopores of MDC-C and the well-dispersed/small TiO2 might be the dominant factors for the superior catalytic conversions. The oxidative desulfurization of other sulfur-containing organic compounds with various electron densities was also studied with MDC-C to understand the mechanism of catalysis. Moreover, the MDC-C catalyst can be reused many times in the oxidative desulfurization reaction after a simple washing with acetone. Finally, composing MOFs and subsequent pyrolysis is suggested as an effective way to prepare a catalyst with well-dispersed active sites, large pores, and high mesoporosity.</P>

Conversion of ethylene into propylene with the siliceous SSZ-13 zeolite prepared without an organic structure-directing agent

Bhadra, Biswa Nath,Song, Ji Yoon,Khan, Nazmul Abedin,Jun, Jong Won,Kim, Tae-Wan,Kim, Chul-Ung,Jhung, Sung Hwa Elsevier 2018 Journal of catalysis Vol.365 No.-

<P><B>Abstract</B></P> <P>The SSZ-13 zeolite was synthesized via seed-assisted method without an organic structure-directing agent (OSDA) from sodium silicate, sodium aluminate, and seed crystals using a wide range of silica/alumina ratios (SARs) in the precursor gels. The SAR of the SSZ-13 was quite high (10) when the SAR of the precursor gel was 40, which was the optimum ratio for high crystallinity. The zeolite was steamed at a high temperature to further increase the SAR via dealumination. The crystal structure of SSZ-13 was stable during steaming because of its high SAR, quite different from another SSZ-13 zeolite obtained from the conversion of zeolite Y in K<SUP>+</SUP> ion in the absence of an OSDA. Steaming at 800 °C and further washing with acid led not only to an increase in the SAR up to 21, but also to a steady increase in porosity. However, the concentration of acid sites, especially strong ones, decreased steadily with increasing steaming time, and octahedral aluminum was removed successfully after adequate steaming. Both pristine and steamed SSZ-13 zeolites were applied to the ethylene-to-propylene (ETP) reaction. With increased steaming time, both the stability of the ethylene conversion and the maximum propylene yield increased. Compared to conventional SSZ-13 zeolites synthesized using expensive OSDAs, adequately steamed SSZ-13 zeolites were competitive for catalyzing the ETP. The exceptional performance of the SSZ-13 zeolite obtained in this study may be understood in terms of its adequate SAR and the decreased number of acid sites (especially strong acid sites), which might be active for hydrogen transfer and ethylene oligomerization. Therefore, it could be suggested that the SSZ-13 zeolite synthesized without an OSDA can be effective in the ETP reaction when steam-treated under suitable conditions.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Siliceous (silica/alumina ratio > 20) SSZ-13 zeolite was obtained without organics. </LI> <LI> Because of high SAR, as-synthesized SSZ-13 can be steamed at high temperature. </LI> <LI> Steaming increased SAR and porosity, and removed octahedral aluminum effectively. </LI> <LI> The SSZ-13s showed remarkable catalyses in ethylene conversion into propylene. </LI> <LI> The remarkable catalyses were due to adequate SAR and removal of strong acid sites. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

MOF-derived carbonaceous materials enriched with nitrogen: Preparation and applications in adsorption and catalysis

Bhadra, Biswa Nath,Vinu, Ajayan,Serre, Christian,Jhung, Sung Hwa Elsevier 2019 Materials today Vol.25 No.-

<P><B>Abstract</B></P> <P>Porous carbons have been considered very important for a long time because of various possible applications. In this review, we summarize the current progress in the field of porous carbons, especially N-enriched carbons, obtained from the carbonization of MOFs with or without additional N-containing compounds. Moreover, metal- or metal oxide-loaded N-doped carbons are also dealt with. Not only the preparation but also the applications in adsorption and catalysis are summarized. More importantly, research ideas or trends will be suggested for further development of these fields. Finally, this study summarizes a number of methods for the preparation of N-enriched carbons (with or without metal or metal oxide) and their efficiencies in various potential applications, including adsorption (liquid-/gas-phase) and organo-/photo-/electro-catalyses, based on their physicochemical properties.</P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>