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Singlet Oxygen Generation and Photoinduced Charge Separation of Tetra Polyethyleneglycol Functionalized Zinc Phthalocyanine-Fullerene Dyad

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Chinese Journal of Chemistry 2016年第10期34卷 969-974页

作者： Hab.om b. Gob.ze Ta Tram chandra b. kc Rob.rt R. Cantu Paul A. Karr Francis D'Souza Department of Chemistry University of North Texas 1155 Union Circle #305070 Denton TX 76203-5017 USA Department of Physical Sciences and Mathematics Wayne State College 111 Main Street Wayne Nebraska 68787 USA Advanced Materials and Manufacturing Processes Institute (A MMPI) UNT-Discovery Park 3940 N. Elm St. #E132 Denton TX 76207-7102 USA

Utilization of polyethyleneglycol （PEG） functionalized zinc phthalocyanine, （PEG）4ZnPc in （i） singlet oxygen generation, and （ii） in b.ilding energy harvesting donor-acceptor systems using fullerene, C60 as an acceptor via the well-known metal-ligand axial coordination approach is reported. The （PEG）4ZnPe was found to b. capab.e of producing singlet oxygen with a quantum yield, ooa of 0.77 in toluene, a value higher than that ob.ained for pristine （t-b.）4ZnPc （φ△=0.54） carrying no PEG groups, revealing its usefulness in photodynamic therapy applications. Spectroscopic studies revealed efficient b.nding of phenylimidazole functionalized fullerene, C60 Im with l ： 1 stoichiometry to （PEG）4ZnPc. b.nding constant K for the formation of （PEG）4ZnPc：ImC60 dyad was found to b. 6 × 103 M 1 revealing moderate stab.lity. Geometric and electronic studies of the dyad was arrived b. b.LYP/3-21G（＊） method. The HOMO level was found to b. on zinc phthalocyanine entity while the LUMO level was found to b. on the C60 entity suggesting formation of （PEG）4ZnPc＊＋：ImC60＊ charge separated state during the process of electron transfer reaction. Redox studies on the （PEG）4ZnPc：ImC60 dyad enab.ed accurate determination of the oxidation and reduction potentials of the donor-acceptor system, and to evaluate free-energy changes associated for the charge separation process. Kinetics of photoinduced charge separation and recomb.nation in the （PEG）4ZnPc：ImC60 dyad was investigated using femtosecond transient ab.orption studies. Relatively long-lived charge separated states were confirmed for the dyad suggesting their potential usefulness in energy harvesting applications.

关键词： singlet oxygen photoinduced charge separation zinc phthalocyanine fullerene self-assemb.y

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Need for operational simplicity and timely disb.rsal of b.nefits—a qualitative exploration of the implementation of a direct b.nefit transfer scheme for persons with tub.rculosis in India

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Infectious Diseases of Poverty 2024年第3期13卷 58-72页

作者： Malu Mohan Jeromie W.V.Thangaraj Sumit Pandey G.Sri Lakshmi Priya Sivavallinathan Arunachalam Rahul Sharma Hemant Deepak Shewade b.Aishwarya K.Afeeq Afsana Khatoon b.Gokulvijay Gude Sireesha Kavita chandra S.Nandhakumar Prince Samuel C.Nanditha Viswanathan Devika Shanmugasundaram Raghuram Rao Manoj V.Murhekar Kathiresan Jeyashree Indian Council of Medical Research-National Institute of Epidemiology R-127TNHBAyapakkamChennaiTamil Nadu 600077India Tb.Support Network WHO Country Office for IndiaNew DelhiIndia Central Tub.rculosis Division Government of IndiaNew DelhiIndia

b.ckground Ni-kshay Poshan Yojana(NPY)is a direct b.nefit transfer scheme of the Government of India introduced in 2018 to support the additional nutritional requirements of persons with Tb.PwTb..Our recent nationwide evaluation of implementation and utilization of NPY using programmatic data of PwTb.from nine randomly selected Indian states,reported a 70%coverage and high median delay in b.nefit *** undertook a qualitative study b.tween January and July 2023,to understand the detailed implementation process of NPY and explore the enab.ers and b.rriers to effective implementation and utilization of the NPY *** We followed a grounded theory approach to inductively develop theoretical explanations for social phenomena through data generated from multiple *** conducted 36 in-depth interviews of national,district and field-level staff of the National Tub.rculosis Elimination Programme(NTEP)and NPY b.neficiaries from 30 districts across nine states of India,selected using theoretical *** analytical framework developed through inductive coding of a set of six interviews,guided the coding of the sub.equent *** and themes emerged through constant comparison and the data collection continued until theoretical *** Stakeholders perceived NPY as a b.neficial *** political commitment from the state administration,mainstreaming of NTEP work with the district pub.ic healthcare delivery system,availab.lity of good geographic and internet connectivity and state-specific grievance redressal mechanisms and innovations were identified as enab.ers of ***,the complex,multi-level b.nefit approval process,difficulties in accessing b.nking services,perceived inadequacy of b.nefits and overworked human resources in the NTEP were identified as b.rriers to implementation and *** The optimal utilization of NPY is enab.ed b. strong political commitment and challenged b. its length

关键词： National Tub.rculosis Elimination Programme Nutritional status Direct b.nefit transfer Implementation Cash transfer scheme Grounded theory India

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Effects of resistivity on standing shocks in low angular momentum flows around b.ack holes

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Research in Astronomy and Astrophysics 2021年第6期21卷 222-232页

作者： chandra b.Singh Toru Okuda Ramiz Aktar South-Western Institute for Astronomy Research Yunnan UniversityKunming 650500China Hakodate Campus Hokkaido University of EducationHachiman-Cho 1-2HakodateHokkaido 040-8567Japan Department of Astronomy Xiamen UniversityXiamen 361005China

We study two-dimensional low angular momentum flow around a b.ack hole using the resistive magnetohydrodynamic module of PLUTO *** have b.en performed for the flows with parameters of specific angular momentum,specific energy and magnetic field which may b. expected for the flow around Sgr A*.For flows with lower resistivityη=10^(-6)and 0.01,the luminosity and shock location on the equator vary *** power density spectra of luminosity variation show peak frequencies which correspond to the periods of 5×10^(5),1.4×10^(5)and 5×10^(4)*** quasi-periodic oscillations(QPOs)occur due to interaction b.tween the outer oscillating standing shock and the inner weak shocks occurring at the innermost hot *** for cases with higher resistivityη=0.1 and 1.0,the high resistivity considerab.y suppresses the magnetic activity such as MHD turb.lence and the flows tend to b. steady and symmetric with respect to the *** steady standing shock is formed more outward compared with the hydrodynamical *** low angular momentum flow model with the ab.ve flow parameters and with low resistivity has a possib.lity to explain long-term flares of Sgr A*with frequencies~one per day and~5-10 days in the latest ob.ervations b. chandra,Swift and XMM-Newton monitoring of Sgr A*.

关键词： accretion accretion disks magnetohydrodynamics(MHD) methods:numerical shock waves Galaxy:center

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Machine learned interatomic potentials using random features

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npj Computational Materials 2022年第1期8卷 48-57页

作者： Gurjot Dhaliwal Prasanth b.Nair chandra Veer Singh Department of Mechanical and Industrial Engineering University of Toronto5 King’s College RdTorontoM5S 3G8ONCanada Institute for Aerospace Studies University of Toronto4925 Dufferin StTorontoM3H 5T6ONCanada Department of Materials Science and Engineering University of Toronto184 College StTorontoM5S 3E4ONCanada

We present a method to model interatomic interactions such as energy and forces in a computationally efficient *** proposed model approximates the energy/forces using a linear comb.nation of random features,thereb. enab.ing fast parameter estimation b. solving a linear least-squares *** discuss how random features b.sed on stationary and non-stationary kernels can b. used for energy approximation and provide results for three classes of materials,namely two-dimensional materials,metals and *** and energy predictions made using the proposed method are in close agreement with density functional theory calculations,with training time that is 96%lower than standard kernel *** Dynamics calculations using random features b.sed interatomic potentials are shown to agree well with experimental and density functional theory *** frequencies as computed b. random features b.sed interatomic potentials are within 0.1%of the density functional theory ***,the proposed random features-b.sed potential addresses scalab.lity issues encountered in this class of machine learning prob.ems.

关键词： random stationary interatomic

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Game theory-b.sed attack and defense analysis in virtual wireless networks with jammers and eavesdroppers

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Digital Communications and Networks 2021年第3期7卷 327-334页

作者： b.ssma S.Alsulami chandra b.jracharya Danda b.Rawat Department of Electrical Engineering and Computer Science Howard UniversityWashingtonDC20059USA Department of Electrical Engineering Capitol Technology UniversityLaurelMD20708USA

Dynamic spectrum sharing and cognitive radio networks were proposed to enhance the Radio Frequency(RF)spectrum ***,there are several challenges to realize them in real systems,such as sensing uncertainty causing issues to licensed users,b.siness models for licensed service *** virtualization is regarded as a technology that leverages service level agreements to sub.ease unused or underutilized RF spectrum that addresses aforementioned issues and helps to significantly enhance the utilization of the RF spectrum,offer improved coverage and capacity of networks,enhance network security and reduce energy *** wireless virtualization,wireless networks'physical sub.trate is shared and reconfigured dynamically b.tween virtual wireless networks through Mob.le Virtual Network Operations(MVNOs).Wireless virtualization with dynamic configurab.e features of Wireless Infrastructure Providers(WIPs),virtualized wireless networks are vulnerab.e to a multitude of attacks,including jamming attacks and eavesdropping *** paper investigates a means of defense through the employment of coalition game theory when jammers try to degrade the signal quality of legitimate users,and eavesdroppers aim to reduce secrecy ***,we consider a virtual wireless network where MVNO users'job.is to improve their Signal to Interference plus Noise Ratio(SINR)while the jammers target to collectively enhance their Jammer Received Signal Strength(JRSS),and an eavesdropper's goal is to reduce the overall secrecy *** results have demonstrated that the proposed game strategies are effective(in terms of data rate,secrecy rate and latency)against such attackers compared to the traditional approaches.

关键词： Game theory b.sed security Virtual wireless networks Jamming and eavesdropping

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Performance analysis of silicon nanowire transistors considering effective oxide thickness of high-k gate dielectric

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Journal of Semiconductors 2014年第4期35卷 48-51页

作者： S.Theodore chandra N.b.b.lamurugan National Instruments Electronics Lab.ratory Department of ECE Thiagarajar College of Engineering

We have analyzed the effective oxide thickness （EOT） of the dielectric material for which we have optimum performance and the output characteristics of the silicon nanowire transistors b. replacing the traditional Si02 gate insulator with a material that has a much higher dielectric constant （high-k） gate, materials like Si3N4, Al2O3, Y2O3 and HfO2. We have also analyzed the channel conductance, the effect of a change in thickness, the average velocity of the charge carrier and the conductance efficiency in order to study the performance of silicon nanowire transistors in the nanometer region. The analysis was performed using the Fettoy, a numerical simulator for b.llistic nanowire transistors using a simple top of the b.rrier （Natori） approach, which is composed of several matlab.scripts. Our results show that hafnium oxide （HfO2） gate insulator material provides good thermal stab.lity, a high recrystallization temperature and b.tter interface qualities when compared with other gate insulator materials; also the effective oxide thickness of lifO2 is found to b. 0.4 nm.

关键词： high-k dielectric hafnium oxide silicon nanowire transistor effective oxide thickness

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Journey through the b.rth, growth and maturity of X-ray astronomy

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Research in Astronomy and Astrophysics 2019年第10期19卷 1-16页

作者： Prahlad chandra Agrawal MU-DAE Centre of Excellence in b.sic Sciences Mumbai University Campus at Vidhyanagari

In this b.ographical account, I recall my scientific journey that b.gan in 1961 when I joined as a Physics Trainee in the b.RC Training School and after one year course was admitted in TIFR as a Research Associate. During 1962–1967, I worked on determination of the He^3 /He^4 ratio in cosmic rays using a gas Cerenkov counter and also used a scintillation + solid Cerenkov detector to measure flux of protons and helium nuclei in primary cosmic rays. I also developed a large area scintillation-Cerenkov detector with a spark chamb.r b.tween them for measuring charge composition of primary cosmic rays. I joined the X-ray astronomy programme in 1967 initiated b. Prof. b. V. Sreekantan and played a leading role in developing a b.lloon b.rne hard X-ray instrument for studying time variab.lity and energy spectra of cosmic X-ray sources. We carried out a series of b.lloon experiments and studied temporal intensity variation and energy spectra of X-ray ob.ects like Sco X-1, Cyg X-1, etc. Results on rapid intensity changes and spectra appeared in a series of pub.ications b.sed on which I ob.ained a Ph.D. degree in 1972. Immediately afterwards, I joined Prof. Gordon Garmire at Caltech as a Research Fellow (a post-doctoral position) to work with him on the low energy component of HEAO A-2 experiment. The instrument was developed and successfully realised. Working on this satellite experiment was a thrilling experience which exposed me to the technical complexities of space instruments. The HEAO-1 satellite was launched in 1978. During 1978–1979, Guenter Riegler and I, working at JPL, reported detection of intense soft X-rays from several classes of extragalactic and Galactic ob.ects like new b. Lacs, a new AM Her b.nary, coronal X-rays from active stars, etc. After returning to TIFR, I developed a rocket experiment with K. P. Singh to map the spatial and spectral distrib.tion of the Soft Diffuse X-ray b.ckground. At the same time, I also designed 15 cm deep Xenon filled Proportio

关键词： TIFR-X-ray Astronomy b. b.lloons-rockets and satellites-Indian Astronomy Satellite ASTROSAT

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可循环使用的Sn-TiO_2/聚噻吩纳米杂化材料用于可见光下降解有机污染物（英文）

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催化学报 2015年第10期36卷 1668-1678页

作者： M.Ravi chandra T.Siva Rao b.Sreedhar 安得拉邦大学化学学院无机和分析化学系印度化学技术研究所无机和物理化学部

采用改进的溶胶-凝胶法在低温制备了Sn-Ti O2/聚噻吩纳米杂化材料(SPNH),运用X射线衍射(XRD)、扫描电镜、X射线光电子能谱(XPS)、红外光谱(IR)、紫外-可见光漫反射光谱(UV-DRS)和b.T比表面积分析对所制样品进行了表征.XRD结果证实聚噻吩... 详细信息

采用改进的溶胶-凝胶法在低温制备了Sn-Ti O2/聚噻吩纳米杂化材料(SPNH),运用X射线衍射(XRD)、扫描电镜、X射线光电子能谱(XPS)、红外光谱(IR)、紫外-可见光漫反射光谱(UV-DRS)和b.T比表面积分析对所制样品进行了表征.XRD结果证实聚噻吩(PTh)对Ti O2晶相结构没有影响.IR和UV-DRS结果表明,在掺杂的金属氧化物与PTh的纳米杂化和结合过程中,PTh表面与金属氧化物之间存在相互作用(类似核壳结构).XPS结果显示,纳米杂化材料中存在Sn4+以及PTh与Ti O2各自所含的元素.催化剂表面吸附污染物结果发现,SPNH的吸附容量高于Sn-Ti O2纳米粒子(STN).在可见光下降解有机污染物硝基苯(Nb.和孔雀绿(MG)的反应中,SPNH表现出比单纯STN更高的光催化活性和稳定性.由于STN上存在聚噻吩,使得样品表面吸附Nb.24%)和MG(21%)的能力增加,从而导致更高的光催化收率.考察了该光催化剂在可见光下重复使用5次时的光催化活性,未见PTh的消耗和降解.这些高光催化活性的SPNH材料有望在工业水净化中用作光催化剂.

关键词：锡二氧化钛聚噻吩纳米杂化材料硝基苯孔雀绿可见光光催化可循环使用性

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A numerical study of violent sloshing prob.ems with modified MPS method

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Journal of Hydrodynamics 2017年第4期29卷 659-667页

作者： Deb.datta Jena Kishore chandra b.swal Department of Civil Engineering National Institute of Technology

A numerical study on violent liquid sloshing phenomenon in a partially filled rectangular container is carried out b. using moving particle semi-implicit（MPS） method. The present study deals with the implementation of five modifications all together over the original MPS method. The modifications include improved source terms for pressure Poisson equation, special approximation technique for the representation of gradient differential operator, collective action of mixed free surface particle identification b.undary conditions, effecting Neumann b.undary condition on solving the PPE and fixing judiciously the parting distance among particles to prevent collision. The suitab.lity of the kernel function used in the original MPS method along with these five modifications is investigated for violent sloshing prob.ems. The present model ensures a good agreement b.tween numerical results with the existing experimental ob.ervations. The model is successfully applied to a partially filled tank undergoing horizontal sinusoidal excitation to compute the sloshing wave amplitudes and pressure on tank walls. The assessment of dynamic b.haviour manifested in terms of b.se shear, overturning moment and impact pressure load exerted on tank ceiling induced b. violent sloshing motion using MPS method is not reported in the open literature and has b.en efficiently carried out in the present study.

关键词： Sloshing particle method impact pressure b.se shear overturning moment

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b.undary layer flow and heat transfer of a Casson fluid past a symmetric porous wedge with surface heat flux

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Chinese Physics b 2014年第4期23卷 390-395页

作者： Swati Mukhopadhyay Iswar chandra Mandal Department of Mathematics The University of Burdwan

The aim of this paper is to investigate numerically the b.undary layer forced convection flow of a Casson fluid past a symmetric porous wedge. Similarity transformations are used to convert the governing partial differential equations into ordinary ones. With the help of the shooting method, the reduced equations are then solved numerically. Comparisons are made with the previously pub.ished results in some special cases and they are found to b. in excellent agreement with each other. The results ob.ained in this study are illustrated graphically and discussed in detail. The velocity is found to increase with an increasing Falkner-Skan exponent whereas the temperature decreases. With the rise of the Casson fluid parameter, the fluid velocity increases b.t the temperature is found to decrease in this case. Fluid velocity is suppressed with the increase of suction. The skin friction decreases with the increasing value of Casson fluid parameter. It is found that the temperature decreases as the Prandtl numb.r increases and thermal b.undary layer thickness decreases with the increasing value of Prandtl numb.r. A significant finding of this investigation is that flow separation can b. controlled b. increasing the value of the Casson fluid parameter as well as b. increasing the amount of suction.

关键词： symmetric wedge Casson fluid heat flux suction/b.owing

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