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Spin Polaron in a Diluted Parabolic Magnetic Quantum Well

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Communications in Theoretical Physics 2010年第4期53卷 782-786页

作者： A.john Peter Department of Physics Zhejiang Institute of Modern Physics Zhejiang University

Theoretical investigations of spin polaron in a quantum well in the spin doping superlattice systems Cd1-xinMnxinTe/Cd1-xMnxout Te are presented in this paper. A variational procedure within the effective mass approximation is employed in the presence of magnetic field to calculate the donor ionization energy. Spin polaronic shifts are estimated using a mean field theory. The results show that the donor binding energy （i） Increases with the reduction in well sizes （ii） Decreases with the magnetic field is increased for a given well width （ill） Increases to a maximum value at 90 A and then decreases as the size of the well increases beyond 90 A and （iv） Spin polaronic shifts to the donor binding energy not only decrease in a magnetic field but also with the well width. The results are compared with the existing available literature.

关键词： spin polaron donor binding quantum dot semimagnetic system

Development of a 3D model for particle-wall collision and induced rotation and its influence on particle trajectories

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Particuology 2024年第11期94卷 211-228页

作者： Cairen Miranda john Palmore Jr. Department of Mechanical Engineering Virginia TechBlacksburg24060VAUSA Department of Mechanical Engineering University of WashingtonSeattle98195WAUSA

The present research focuses on improving the prediction of rotating particle *** particle-surface collision models do not accurately predict the particle rebound when taking rotation into *** data,such as the studies by Gorham and Kharaz(2000),Buck,Tang,Heinrich,Deen and Kuipers(2017),and Dong and Moys(2006)show that the Tsuji,Oshima and Morikawa(1985)model is inaccurate due to the incorrect tangential coefficient of restitution ***,Kuipers,Mohd Salleh,Stein,and Seville(2001)introduced a similar model to the work by Tsuji et al.(1985)which includes a tangential coefficient of restitution but is only in two dimensions and does not consider out of plane *** work re-derives the particle collision model from the impulse equations for binary collisions in 3D while considering rotating *** derived equations in this work compares well to experimental particle-surface impact *** implications of this model are seen by investigating erosion due to particle collision in a simple pipe *** is shown that Tsuji et al.(1985)over predicts the *** small differences in particle trajectories between the present model and the Tsuji et al.(1985)model will grow in complex flows with multiple close range particle impacts leading to inaccurate erosion predictions which will negatively impact the design of turbomachinery and pneumatic pipes.

关键词： Particle collisions CFD Rotation Three dimensional

Phytoremediation of engineered nanoparticles using aquatic plants: Mechanisms and practical feasibility

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Journal of Environmental Sciences 2020年第7期32卷 151-163页

作者： Parisa Ebrahimbabaie Weeradej Meeinkuirt john Pichtel Ball State University EnvironmentGeology and Natural ResourcesMuncieIN 47306USA Mahidol University Nakhonsawan CampusNakhonsawan 60130Thailand

Certain plants have demonstrated the capability to take up and accumulate metals,thus offering the potential to remediate metal-contaminated water and *** aquatic species have further been identified which can take up metal and metal oxide engineered nanoparticles(ENPs).It is important to evaluate if aquatic plants exhibiting potential for metal phytoremediation can be applied to remediation of metallic *** the interactions between ENPs and aquatic plants,and evaluating possible influences on metal uptake and phytoremediation processes is therefore *** review article will address the feasibility of green plants for treatment of ENP-affected aquatic *** will include common types of ENPs in current use;transformations of ENPs in aquatic systems;the importance of microorganisms in supporting plant growth;ENP entry into the plant;the influence of microorganisms in promoting plant uptake;and recent findings in phytoremediation of ENP-affected water,including applications to constructed wetlands.

关键词： Aquatic plants Constructed Wetlands Nanoparticles Phytoremediation

2D matrix based indexing with color spectralhistogram for efficient image retrieval

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Journal of Systems Engineering and Electronics 2016年第5期27卷 1122-1134页

作者： maruthamuthu ramasamy john sanjeev kumar athisayam Department of Software Engineering RVS College of EngineeringDindigul 624005India Department of Computer Applications Thiagarajar College of EngineeringMadurai 625015India

A novel content based image retrieval （CBIR） algorithmusing relevant feedback is presented. The proposed frameworkhas three major contributions： a novel feature descriptor calledcolor spectral histogram （CSH） to measure the similarity betweenimages; two-dimensional matrix based indexing approach proposedfor short-term learning （STL）; and long-term learning （LTL）.In general, image similarities are measured from feature representationwhich includes color quantization, texture, color, shapeand edges. However, CSH can describe the image feature onlywith the histogram. Typically the image retrieval process starts byfinding the similarity between the query image and the imagesin the database; the major computation involved here is that theselection of top ranking images requires a sorting algorithm to beemployed at least with the lower bound of O（n log n）. A 2D matrixbased indexing of images can enormously reduce the searchtime in STL. The same structure is used for LTL with an aim toreduce the amount of log to be maintained. The performance ofthe proposed framework is analyzed and compared with the existingapproaches, the quantified results indicates that the proposedfeature descriptor is more effectual than the existing feature descriptorsthat were originally developed for CBIR. In terms of STL,the proposed 2D matrix based indexing minimizes the computationeffort for retrieving similar images and for LTL, the proposed algorithmtakes minimum log information than the existing approaches.

关键词： content based image retrieval (CBIR) color spectralhistogram (CSH) short-term learning (STL) long-term learning(LTL) similarity measures.

CFD-DEM simulation of Small-Scale Challenge Problem 1 with EMMS bubble-based structure-dependent drag coefficient

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Particuology 2021年第2期19卷 48-61页

作者： Musango Lungu john Siame Lloyd Mukosha Multiphase Flow Research Group Chemical Engineering DepartmentSchool of Mines and Mineral SciencesCopperbelt UniversityKitwe 10101Zambia

In this study,the energy minimization multi-scale(EMMS)/Bubbling model is coupled with the computational fluid dynamics/discrete element method(CFD-DEM)model via a structure-dependent drag coefficient to simulate the National Energy Technology Laboratory(NETL)small-scale challenge problem using the open-source multiphase flow code *** numerical predictions are compared against particle velocity measurements obtained from high-speed particle image velocimetry(HSPIV)and differential pressure *** drag-reduction effect of the EMMS bubble-based drag coefficient is observed to significantly improve predictions of the horizontal particle velocity and granular temperature when compared to several other drag coefficients tested;however,the vertical particle velocity and pressure fluctuation characteristic predictions are *** drag-reduction effect is characterized by a reduction in the sizes of slugs or voids,as identified through spectral decomposition of the pressure ***,this study shows great promise in employing drag coefficients,developed via multi-scale approaches(such as the EMMS paradigm),in CFD-DEM models.

关键词： CFD-DEM Drag model EMMS/Bubbling model Fluidization Multi-scale

The influence of abiotic and spatial variables on woody and herbaceous species abundances in a woodland-grassland system in the Eastern Terai of India

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Journal of Plant Ecology 2022年第1期15卷 155-167页

作者： Dhritiman Das Subham Banerjee john Lehmkuhl Jagdish Krishnaswamy Robert john Academy of Conservation Science and Sustainability Studies Ashoka Trust for Research in Ecology and the Environment(ATREE)Royal EnclaveSriramapuraJakkur PostBangalore 560064India Manipal Academy of Higher Education Manipal 576104KarnatakaIndia Pygmy Hog Conservation Programme Durrell Wildlife Conservation TrustLes Augres ManorLa Profonde RueTrinityJersey JE35BPChannel Islands Department of Biological Sciences Indian Institute of Science Education and ResearchKolkataRoom 214Research ComplexMohanpur 741246West BengalIndia USDA Forest Service Pacific Northwest Research StationWenatcheeWA 98801USA

The environmental factors that influence tree-grass abundances in tropical savanna and grasslands are not well understood,particularly for woodland-grassland mosaics in humid *** studied the effects of abiotic and spatial variables on woody and herbaceous species distributions in a Terai ecosystem of northeastern *** evaluated the importance of climatic and non-climatic factors that maintain variable tree-grass ratios across the landscape,and also accounted for spatial connectivity and *** measured species abundances of woody and herbaceous plant species in 134 plots with each 30 m×30 m in a 519 km^(2)protected Terai habitat,and derived several climatic and non-climatic environmental *** constructed variables based on different models of spatial connectivity among sites,to test their influence on species *** then used redundancy analyses and variation partitioning to quantify the importance of environmental variables and spatial structure on variation in tree-grass *** found that environmental variables including rainfall,fire,water stress,topography and soil nutrients had statistically significant effects on species abundance and tree-grass *** structure was significant,and the best spatial model was an inverse distance-weighted model with linkage extending to 23.5 km,indicating weak dispersal *** 21%of the variation in species abundance was explained by the selected environmental and spatial *** results indicate that dynamic plant communities in which spatial-temporal variation in environmental factors may drive stochasticity in species distribution and abundance,thus dominantly influencing on the vegetation mosaic.

关键词： woodland-grassland Eastern Terai Manas National Park variation partitioning ground fires spatial connectivity

Optimization of specific cell-peptide interactions at the bio-material interface via regulation of nonspecific biofouling interactions

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Science China Chemistry 2020年第2期63卷 143-144页

作者： john L.Brash Department of Chemical Engineering School of Biomedical EngineeringMcMaster University

Materials that interact with biological systems in a wellcontrolled,predictable manner are highly sought after for numerous biomedical and biotechnological *** example,it is essential that devices such as stents or heart valves in the blood stream of patients do not cause thrombosis or infection,or that biosensors do not lose their function due to adverse interactions with the bio environment.A general approach to the design of biointerfaces that addresses this need has been pursued over a number of years[1].It has two elements:(1)prevention of non-specific interfacial interactions,and(2)promotion of specific biointeractions required for the intended functioning of the *** practice this means preventing all interactions except for the desired one(s).With respect to the first point it should be appreciated that biological species such as proteins and cells have a natural affinity for the interfacial ***,the realization of a surface that eliminates the adsorption/adhesion of these species is extremely *** of PEO/PEG,other hydrophilic polymers(PVP,PHEMA),and zwitterionic polymers[2]to the surface is the most common strategy to achieve“bio-resistance”.Regarding the second point,the surface must be designed so that it interacts selectively and exclusively with the component(s)(proteins,cells)that will give the desired *** this purpose,“ligands”that bind these specific components are incorporated into the surface[3].

关键词： desired interfacial realization

Iwasawa Theory of Quadratic Twists of X0（49）

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Acta Mathematica Sinica,English Series 2018年第1期34卷 19-28页

作者： Junhwa CHOI john COATES Department of Mathematics POSTECH Emmanuel College Cambridge University

The field K ---- Q（x/-AT） is the only imaginary quadratic field with class number 1, in which the prime 2 splits, and we fix one of the primes p of K lying above 2. The modular elliptic curve X0 （49） has complex multiplication by the maximal order O of K, and we let E be the twist of Xo （49） by the quadratic extension K（v/M）/K, where M is any square free element of O with M -- i mod 4 and （M, 7） = 1. In the present note, we use surprisingly simple algebraic arguments to prove a sharp estimate for the rank of the MordeII-Weil group modulo torsion of E over the field F∞=k（Ep∞ ）, where Epic denotes the group of p∞-division points on E. Moreover, writing B for the twist of X0（49） by K（C/ET）/K, our Iwasawa-theoretic arguments also show that the weak form of the conjecture of Birch and Swinnerton-Dyer implies the non-vanishing at s =1 of the complex L-series of B over every finite layer of the unique Z2-extension of K unramified outside p. We hope to give a proof of this last non-vanishing assertion in a subsequent paper.

关键词： Birch-Swinnerton-Dyer conjecture elliptic curves Iwasawa theory

Ground support design for dynamic loading conditions:A quantitative data-driven approach based on rockburst case studies

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Journal of Rock Mechanics and Geotechnical Engineering 2019年第5期11卷 909-919页

作者： Philippe Morissette john Hadjigeorgiou Agnico Eagle Mines Limited 10 200route de PreissacRouyn-NorandaJ0Y 1C0Canada University of Toronto TorontoM5S 3E3Canada

There are considerable challenges associated with the design of ground support for seismically-active underground *** is extremely difficult to establish the demand on ground support as well as the capacity of a ground support *** resulting dynamic or impact loads caused by mining-induced seismicity are difficult to anticipate and *** performance of a ground support system is defined by the load distribution and interaction between several reinforcement and surface support ***,the design of ground support in seismically-active mines tends to evolve,or be modified based on qualitative assessments of perceived performance or response to significant seismic events or *** research is motivated by a need to provide quantitative and data-driven design guidelines for ground support systems subjected to dynamic-loading *** data were collected from three deep and seismically-active underground mines in the Sudbury basin in *** constructed database comprises 209 seismic events that resulted in damage to mine excavations and ground *** events were associated with damage at 324 locations within the three *** developed ground support design strategy,based on these documented case studies,identifies areas where the use of dynamic or enhanced support should be *** developed design methodology provides guidelines for the zoning of mine locations in which installation of enhanced support is recommended,the specifications for an optimal ground support system,and the timing or sequence of installation.

关键词： Ground support design Mining-induced seismicity Rockburst