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Thorium/uranium mixed oxide nanocrystals： Synthesis, structural characterization and magnetic properties

Nano Research 2014年第1期7卷 119-131页

作者： Damien Hudry Jean-Christophe Griveau Christos Apostolidis Olaf Walter Eric Colineau Gert Rasmussen Di wang venkata sai kiran chakravadhaluna Eglantine Courtois Christian Kubel Daniel Meyer European Commission: Joint Research Centre Institute for Transuranium Elements P. O. Box 2340 76125 Karlsruhe Germany Karlsruhe Institute of Technology Institute ofNanotechnology Hermann-von-Helmholtz-Platz1 76344 Eggenstein-Leopoldshafen Germany Karlsruhe Institute of Technology Karlsruhe Nano Micro Facility Hermann-von-Helmholtz-Platz 1 76344 Eggenstein-Leopoldshafen Germany Helmholtz Institute UIm for Electrochemical Energy Storage Albert-Einstein-Allee 11 89069 UIm Germany Institut de Chimie Separative de Marcoule UMR 5257 BP 1717 1 30207 Bagnols sur Ceze Cedex France Karlsruhe Institute of Technology Institute for Catalysis Research and Technology Hermann-von-Helmholtz-Platz 1 76344 Eggenstein Leopoldshafen Germany

One of the primary aims of the actinide community within nanoscience is to develop a good understanding similar to what is currently the case for stable elements. As a consequence, efficient, reliable and versatile synthesis techniques dedicated to the formation of new actinide-based nano-objects (e.g. nanocrystals) are necessary. Hence, a “library” dedicated to the preparation of various actinidebased nanoscale building blocks is currently being developed. Nanoscale building blocks with tunable sizes, shapes and compositions are of prime importance. So far, the non-aqueous synthesis method in highly coordinating organic media is the only approach which has demonstrated the capability to provide size and shape control of actinide-based nanocrystals (both for thorium and uranium, and recently extended to neptunium and plutonium). In this paper, we demonstrate that the non-aqueous approach is also well adapted to control the chemical composition of the nanocrystals obtained when mixing two different actinides. Indeed, the controlled hot co-injection of thorium acetylacetonate and uranyl acetate (together with additional capping agents) into benzyl ether can be used to synthesize thorium/uranium mixed oxide nanocrystals covering the full compositional spectrum. Additionally, we found that both size and shape are modified as a function of the thorium:uranium ratio. Finally, the magnetic properties of the different thorium/uranium mixed oxide nanocrystals were investigated. Contrary to several reports, we did not observe any ferromagnetic behavior. As a consequence, ferromagnetism cannot be described as a universal feature of nanocrystals of non-magnetic oxides as recently claimed in the literature.

关键词：混合氧化物纳米晶体合成技术双氧铀磁学性质结构表征钍锕系元素

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Nonlinear Rydberg exciton-polaritons in Cu2O microcavities

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Light(Science & Applications) 2024年第4期13卷 619-627页

作者： Maxim Makhonin Anthonin Delphan Kok Wee Song Paul Walker Tommi Isoniemi Peter Claronino Konstantinos Orfanakis sai kiran Rajendran Hamid Ohadi Julian Heckötter Marc Assmann Manfred Bayer Alexander Tartakovskii Maurice Skolnick Oleksandr Kyriienko Dmitry Krizhanovskii Department of Physics and Astronomy University of SheffieldSheffield S37RHUK. Department of Physics and Astronomy University of ExeterStocker RoadExeter EX44PYUK. SUPA School of Physics and AstronomyUniversity of St AndrewsSt Andrews KY169SSUK. Fakultät Physik TU DortmundAugust-Schmidt-Straße 444227 DortmundGermany

Rydberg excitons(analogues of Rydberg atoms in condensed matter systems)are highly excited bound electron-hole states with large Bohr *** interaction between them as well as exciton coupling to light may lead to strong optical nonlinearity,with applications in sensing and quantum information ***,we achieve strong effective photon–photon interactions(Kerr-like optical nonlinearity)via the Rydberg blockade phenomenon and the hybridisation of excitons and photons forming polaritons in a Cu2O-filled *** pulsed resonant excitation polariton resonance frequencies are renormalised due to the reduction of the photon-exciton coupling with increasing exciton *** analysis shows that the Rydberg blockade plays a major role in the experimentally observed scaling of the polariton nonlinearity coefficient as∝n4.4±1.8 for principal quantum numbers up to n=*** high principal quantum numbers studied in a polariton system for the first time are essential for realisation of high Rydberg optical nonlinearities,which paves the way towards quantum optical applications and fundamental studies of strongly correlated photonic(polaritonic)states in a solid state system.

关键词： density Rydberg polar

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Erosion Wear Behaviour of Kenaf/Glass Hybrid Polymer Composites

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Journal of Harbin Institute of Technology(New Series) 2024年第1期31卷 78-89页

作者： Chandrakanta Mishra Deepak Kumar Mohapatra Chitta Ranjan Deo Punyapriya Mishra kiran Kumar Ekka Department of Mechanical Engineering Veer Surendra Sai University of TechnologySambalpur 768018India

The awareness amongst the researchers to develop an environment friendly sustainable material leads to explore new class of plant-based fiber for making composites. Hybridization of such plant-based fiber with inclusion of engineered fiber is one of the promising methods to not only enhanced the mechanical performance but also suppressed the drawbacks that associate with such plant-based fiber to some extent. A usual hand lay-up method was taken-up in this work to fabricate four layered of hybrid kenaf(K)/glass(G)polyester laminates with different stacking order such as KKKK,KGKG,KGGK,GKKG and GGGG. The erosive character of the laminates was examined under three distinct particle velocities(48m/s, 70m/s,82m/s)and four different impact angles(30°, 45°, 60°, 90°). All fabricated laminates exhibited a semiductile character at lower velocities(48m/s and70m/s)as peak wear rate was observed at45° impact angle. However,they showed a semi-brittle character at high velocity(82m/s)as maximum rate of erosion was noticed at60° impact angle. Again,the influence of stacking order of piles on erosion wear was also clearly noticed. Moreover,the semi-brittle/semi-ductile characterization was also evidenced in accordance to the range of erosion efficiencies. The micro-structures of worn surfaces were inspected thoroughly from the images of scanning electron microscope(SEM)to evident the mechanism of erosion.

关键词： hybrid composites erosion wear void micro⁃hardness

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Performance Improvement of Kenaf/Glass Polymer Hybrid Composites by Effective Application of Fish Scale Powder as Filler:A Novel Approach

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Journal of Harbin Institute of Technology(New Series) 2024年第3期31卷 80-96页

作者： Chandrakanta Mishra Deepak Kumar Mohapatra Chitta Ranjan Deo Chetana Tripathy kiran Kumar Ekka Department of Mechanical Engineering Veer Surendra Sai University of TechnologySambalpur 768018OdishaIndia

Modern technology for developing new items made from renewable resources is becoming more and more popular as a result of rising environmental ***,contemporary polymer composites have included the hybridization of natural fibers with synthetic ones,along with the inclusion of a variety of biowaste filler for developing sustainable *** this work,the kenaf/glass hybrid polyester composites are strengthened by the addition of fish scale(FS),which is taken from the fish􀆳s outermost layer of *** different stacked-order laminates,such as KKKK,KGKG,GKKG,KGGK,and GGGG,are fabricated by using the hand lay-up method with four different weight concentrations of filler content:0%,5%,10%,and 15%.Mechanical possessions such as tensile,flexural,impact strength and micro-hardness have been evaluated through experimentation in accordance with ASTM *** experimental findings revealed that,the tensile strength and micro-hardness value of KGKG laminates with 15wt% of FS filler are found to be maximum of 118.72 MPa and 17.82 HV respectively which are 39.67%and 26.11%greater than that of KGKG laminates without FS ***,the flexural and impact strength of same laminates with 10 wt% FS filler exhibited a maximum value of 142.77 MPa and 62.08 kJ/m^(2).In order to corroborate its applicability for structural and building materials in open environment,the dimensional stability of the composite has been studied through moisture absorption *** influences of FS filler loading on dimensional stability and resistance to moisture absorption capacity of laminates are also *** experimental results reflected that the addition of FS-filler has significantly improved the dimensional stability of the laminates in moist environment by reducing the moisture absorption *** further support the mode of failures,a fractography investigation of fractured surfaces was conducted.

关键词： fish scale fiber polyester hybrid composites mechanical properties

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Non-invasive optical characterization and estimation of Zn porosity in gas tungsten arc welding of Fe–Al joints using CR model and OES measurements

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Plasma Science and Technology 2023年第11期25卷 133-141页

作者： sai SRIKAR Tinku KUMAR Degala venkata kiran Reetesh Kumar GANGWAR Department of Physics&CAMOST Indian Institute of Technology TirupatiYerpedu 517619India Department of Mechanical Engineering Indian Institute of Technology TirupatiYerpedu 517619India

In this study,we employed a non-invasive approach based on the collisional radiative(CR)model and optical emission spectroscopy(OES)measurements for the characterization of gas tungsten arc welding(GTAW)discharge and quantification of Zn-induced porosity during the GTAW process of Fe–Al *** OES measurements were recorded as a function of weld current,welding speed,and input *** OES measurements revealed significant line emissions from Zn-I in 460–640 nm and Ar-I in 680–800 nm wavelength ranges in all experimental *** OES coupled CR model approach for Zn-I line emission enabled the simultaneous determination of both essential discharge parameters *** temperature and electron ***,these predictions were used to estimate the Zn-induced porosity using OES-actinometry on Zn-I emission lines using Ar as actinometer *** OES-actinometry results were in good agreement with porosity data derived from an independent approach,i.e.x-ray radiography *** current study shows that OES-based techniques can provide an efficient route for real-time monitoring of weld quality and estimate porosity during the GTAW process of dissimilar metal joints.

关键词： optical emission spectroscopy collisional radiative model actinometry GTAW Fe Al joints Zn vapor porosity radiographic imaging(Some figures may appear in colour only in the online journal)

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Morphologic,Radiographic,and Stereomicroscopic Evaluation of Teeth Subjected to High Temperatures:An In vitro Forensic Study

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Journal of Forensic Science and Medicine 2023年第3期9卷 228-235页

作者： M.sai Geethika N.Purnachandra Rao Naik A.Ravi kiran Y.Samatha B.Naveen Kumar P.Shruthi Sethu Manjusha Saranu K.Pavani Sanjana Marpuri Department of Oral Medicine and Radiology Sibar Institute of Dental SciencesGunturAndhra PradeshIndia

Background:To evaluate morphologic,radiographic,and stereomicroscopic changes of teeth when subjected to specific high temperatures in both direct heat and gradual heat and to compare the changes among two heat groups and also among different types of *** and Methods:An in vitro study was conducted on 90 healthy extracted human teeth,in which the teeth were divided into two *** 1(45)was subjected to direct heat and Group 2(45)was subjected to gradual *** 1 and Group 2 were further subdivided into three subgroups(A)anteriors,(B)premolars,and(C)molars each consisting of 15 *** were subjected to temperatures of 200°C,400°C,600°C,800°C,and 1000°C in a muffle electric *** color changes were noted using the Revised Munsell soil color chart and the radiographic and stereomicroscopic changes were *** results obtained were subjected to statistical ***:Teeth in direct heat showed more destructive changes at lower temperatures,i.e.,400°C and 600°C when compared to gradual heat where changes are observed at 600°C and 800°*** different types of teeth,anteriors and premolars showed more changes when compared to *** and Conclusion:It can be concluded that dental evidence may provide clues to solve the mystery in fire investigations as dental structures are the last to be destroyed under extreme conditions,whether temperature,acid,or putrefaction.

关键词： Color changes in teeth forensic odontology high temperatures incinerated teeth radiographs stereomicroscope

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Generation of Labelled Datasets to Quantify the Impact of Security Threats to Cloud Data Centers

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Journal of Information Security 2016年第3期7卷 172-184页

作者： sai kiran Mukkavilli Sachin Shetty Liang Hong Department of Electrical & Computer Engineering Tennessee State University Nashville TN USA

Anomaly based approaches in network intrusion detection suffer from evaluation, comparison and deployment which originate from the scarcity of adequate publicly available network trace datasets. Also, publicly available datasets are either outdated or generated in a controlled environment. Due to the ubiquity of cloud computing environments in commercial and government internet services, there is a need to assess the impacts of network attacks in cloud data centers. To the best of our knowledge, there is no publicly available dataset which captures the normal and anomalous network traces in the interactions between cloud users and cloud data centers. In this paper, we present an experimental platform designed to represent a practical interaction between cloud users and cloud services and collect network traces resulting from this interaction to conduct anomaly detection. We use Amazon web services (AWS) platform for conducting our experiments.

关键词： Amazon Web Services Anomaly Detection Cloud Computing Datasets Intrusion Detection Network Traces

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Aceclofenac-Soluplus&reg Nanocomposites for Increased Bioavailability

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Soft Nanoscience Letters 2015年第2期5卷 13-20页

作者： Sandeep Patnaik sai kiran Aditha Tanu Rattan venkataramaniah Kamisetti Department of Physics Sri SathyaSai Institute of Higher Learning Prasanthi Nilayam India

Aceclofenac is a new generational Non-Steroidal Anti-Inflammatory Drug (NsaiD), and is considered a better alternative to the popular pain-killer diclofenac, as it overcomes some of the adverse gastrointestinal and cardiac side effects associated with the latter. However, the bioavailability of the drug remains limited due to low aqueous solubility (0.058 μg/mL) and poor dissolution characteristics. Hence, improving its dissolution characteristics is of prime significance in order to establish its optimal therapeutic efficacy. In an effort to tackle this issue, we report the use of novel Soluplus®-based nanocomposites, prepared from emulsion templates, as effective drug loading agent for aceclofenac. Nanoemulsion templates were prepared by high-shear homogenization using a probe sonicator. The emulsions were subsequently lyophilized to obtain free flowing powders. The amorphization of the drug with increasing polymer content was clearly observed from powder X-ray diffractogram, while the drug-polymer interaction was explored by FTIR spectroscopy. The phase purity and homogeneity of the formulation was characterized using Differential Scanning Calorimetry. The dissolution profiles of the formulations were established by an USP paddle apparatus. Phase solubility study was conducted to evaluate the effect of polymer concentration on aqueous solubility of aceclofenac. The values of Gibbs-free energy (ΔG°tr) associated with the aqueous solubility of aceclofenac in the presence of Soluplus was used to optimize the polymer content. The in vitro dissolution rates of aceclofenac from the nanoparticles were significantly higher compared to the pure drug. Thus, Soluplus nanoparticles provide promising formulations for the improvement of the dissolution profiles and thus, the bioavailability, of aceclofenac.

关键词： Aceclofenac Soluplus Nanocomposites Dissolution Emulsion

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Efficient Text Extraction Algorithm Using Color Clustering for Language Translation in Mobile Phone

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Journal of Signal and Information Processing 2012年第2期3卷 228-237页

作者： Adrián Canedo-Rodríguez Jung Hyoun Kim Soo-Hyung Kim John Kelly Jung Hee Kim Sun Yi sai kiran Veeramachaneni Yolanda Blanco-Fernández College of Engineering North Carolina A&T State University Greensboro USA Department of Computer Science Chonnam National University Kwangju South Korea Department of Telematics Engineering University of Vigo Vigo Spain

Many Text Extraction methodologies have been proposed, but none of them are suitable to be part of a real system implemented on a device with low computational resources, either because their accuracy is insufficient, or because their performance is too slow. In this sense, we propose a Text Extraction algorithm for the context of language translation of scene text images with mobile phones, which is fast and accurate at the same time. The algorithm uses very efficient computations to calculate the Principal Color Components of a previously quantized image, and decides which ones are the main foreground-background colors, after which it extracts the text in the image. We have compared our algorithm with other algorithms using commercial OCR, achieving accuracy rates more than 12% higher, and performing two times faster. Also, our methodology is more robust against common degradations, such as uneven illumination, or blurring. Thus, we developed a very attractive system to accurately separate foreground and background from scene text images, working over low computational resources devices.

关键词： Text Extraction Color Quantization Text Binarization Language Translation

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