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Solitary kinetic Alfvén waves in a dense electron–positron–ion plasma with degenerate electrons and positrons

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plasma Science and Technology 2017年第12期19卷 42-49页

作者： Monzurul K AHMED om p sah Depatment of physics Birjhora MahavidyalayaBongaigaon-783380AssamIndia

Through the use of a reductive perturbation technique, solitary kinetic Alfvén waves（KAWs） are investigated in a low but finite b（particle-to-magnetic pressure ratio） dense electron–positron–ion plasma where electrons and positrons are degenerate. The degenerate plasma model considered here permits the existence of sub-Alfvénic compressive solitary KAWs. The influence of r（equilibrium positron-to-ion density ratio）, sF（electron-to-positron Fermi temperature ratio）, b and obliqueness parameter lzon various characteristics of solitary KAWs are examined through numerical plots. We have shown that there exists a critical value of lzat which a soliton width attains its maximum value which decreases with an increase in r and *** is also found that solitons with a higher energy propagate more obliquely in the direction of an ambient magnetic field. The results of the present investigation may be useful for understanding low frequency nonlinear electromagnetic wave propagation in magnetized electron–positron–ion plasmas in dense stars. Specifically, the relevance of our investigation to a pulsar magnetosphere is emphasized.

关键词： kinetic Alfvén waves solitons electron–positron–ion plasma degenerate plasma Thomas–Fermi approximation

Fault Detection for Microgrid Feeders Using Features Based on Superimposed positive-sequence power

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Journal of Modern power Systems and Clean Energy 2023年第6期11卷 1948-1958页

作者： Salauddin Ansari om Hari Gupta om p.Malik Department of Electrical Engineering National Institute of TechnologyJamshedpur 831014India IEEE Department of Electrical and Software Engineering University of Calgary2500 University Drive NWCalgary Alberta T2N 1N4Canada

With the integration of distributed generation(DG) into a microgrid, fault detection has become a major task to accomplish. A scheme for microgrid feeder protection based on a newly proposed feature, ΔRp, defined as the ratio of the sum of positive-sequence real power(pSRp) at the two ends of the feeder to the larger of the pSRps among the two ends, is proposed. If ΔRp is larger than a threshold, an internal fault is detected;otherwise, the fault is external or there is no fault. The proposed scheme is tested in various scenarios, including fault type, fault resistance, fault location, fault inception angle, varying DG penetration levels, and simultaneous, evolving, and composite faults. In addition to this, the proposed scheme offers a robust performance when subjected to noise, synchronization error, changes in sampling frequency, and changes in the topology of a microgrid. The dominancy of the proposed scheme is proven by a comprehensive comparative study with various available recent schemes. Test results on the IEEE 13-bus network indicate the viability of the proposed protection scheme for a microgrid. Finally, the proposed scheme has been validated on a real-time simulator.

关键词： Fault detection distributed generation microgrid protection superimposed power

Spatial Variability of Mass Movements in the Satluj Valley,Himachal pradesh during 1990～2006

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Journal of Mountain Science 2008年第1期5卷 38-51页

作者： Vikram GUpTA M.p.sah Wadia Institute of Himalayan Geology Dehra Dun-24 8 001 (Uttarakhand)

Satluj Valley is known to have a history of landslides and related mass movement activities since the geological times. Geological and geomorphological settings combined with anthropogenic activities constitute a propensity towards slope failure. During the last two decades,the area witnessed substantial increase in athropogenic pressure,mainly due to the exploitation of hydropower potential,changing landuse pattern and population growth. In addition,a shift of the climatic patterns in the form of larger area falling under the influence of rains was observed. These natural as well as anthropogenic changes in the area have resulted in increased spatial coverage of landslide in the area. This paper documents these changes during 1990～2006.

关键词： Landslides Mass movement Satluj Valley Himachal pradesh India

An Overview of the Geoenvironmental Status of the Kullu Valley, Himachal pradesh, India

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Journal of Mountain Science 2007年第1期4卷 3-23页

作者： M.p. sah R.K Mazari Wadia Institute of Himalayan Geology33 Gen. Mahadeo Singh Road Dehra Dun-248001 India

The north-south trending Kullu valley between Rohtang in the north and Hansu in the south is a wide and open valley filled with Quaternary sediments along the main eourse of the Beas River. The valley in the middle is drained by the Beas River and numerous tributaries join it laterally. The tributary ehannels have deposited large alluvial fans at their mouths whieh form three distinct levels. The Beas River has deposited alluvial terraees, whieh are very distinct towards the lower reaehes and form three to four levels. The upper slopes and high altitudinal areas are eovered with periglaeial and glaeial deposits. The terraee, fan and hill slopes have provided an ideal geoenvironment for human aetivities inehiding agrieulture, hortieulture, dense settlements and other eivil establishments. The Kulhi Valley is prone to various natural hazards, flash floods and eloudbursts that are very eommon in this valley due to its peeuliar geomorphie eonclifton, high relief of peripheral ridges and impact of monsoon winds. The studies carried out so far indicate that the losses caused by these phenomena both in terms of life and property are mainly due to unwise human interaction with the geoenvironment of the area. The paper gives an overview of the geoenvironmental status of the Kulhi Valley and suggests the necessity of undertaking further detailed studies ineluding resouree mapping for balaneed development of the area.

关键词： Geoenvironment Kullu Valley geomorphology natural hazard climate

partial sums of generalized harmonic starlike univalent functions generated by a (p,q)−Ruscheweyh-type harmonic differential operator

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Applied Mathematics(A Journal of Chinese Universities) 2024年第4期39卷 584-595页

作者： om p Ahuja Asena Cetinkaya Raj Kumar Department of Mathematical Sciences Kent State UniversityOhio44021USA Department of of Mathematics and Computer Science Istanbul Kultur UniversityIstanbulTurkey Department of of Mathematics DAV UniversityJalandharIndia

Let H denote the class of complex-valued harmonic functions f defined in the open unit disc D and normalized by f(0)=fz(0)-1=*** this paper,we define a new generalized subclass of H associated with the(p,q)-Ruscheweyh-type harmonic differential operator in *** first obtain a sufficient coefficient condition that guarantees that a function f in H is sense-preserving harmonic univalent in D and belongs to the aforementioned *** this coefficient condition,we then examine ratios of partial sums of f in *** all cases the results are *** addition,the results so obtained generalize the related works of some authors,and many other new results are obtained.

关键词： (p,q)-calculus (p,q)-derivative operator q-calculus q-derivative operator (p,q)-Ruscheweyhtype harmonic differential operator partial sums coefficient estimate

On Almost Armendariz Ring

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Algebra Colloquium 2020年第2期27卷 199-212页

作者： om prakash Sushma Singh K.p.Shum Department of Mathematics Indian Institute of Technology Patna PatnaBihar 801106India Department of Mathematics John Fulton Center The Chinese University of Hong KongShatinN.T.Hong KongChina

In this paper,we introduce the notion of an almost Armendariz ring,which is a generalization of an Armendariz ring,and discuss some of its *** has been found that every almost Armendariz ring is weak Armendariz but the converse is not *** prove that a ring R is almost Armendariz if and only if R[x]is almost *** is also shown th at if R/I is an almost Armendariz ring and I is a semicommutative ideal,then H is an almost Armendariz ***,the class of minimal non-commutative almost Armendariz rings is completely determined,up to isomorphism(minimal means having smallest cardinality).

关键词： Armendariz ring almost Armendariz ring weak Armendariz ring lower nil radical reduced ring semicommutative ring

The effects of habitat fragmentation on the reproduction and abundance of Angadenia berteroi

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Journal of plant Ecology 2017年第2期10卷 340-348页

作者： Beyte Barrios Roque Suzanne Koptur Jay p.sah plant Ecology Lab Department of Biological SciencesFlorida International University11200 SW 8th StMiamiFL 33199USA South Florida Terrestrial Ecosystems Lab Southeast Environmental Research CenterFlorida International University11200 SW 8th STMiamiFL 33199USA

Aims The pine rocklands of southern Florida are a fire-dependent forest associated with outcrops of *** rockland plants have sev-eral adaptations to fire,and for many species,burning increases plant growth,flowering and seedling *** pine rockland forest has been reduced and fragmented in recent *** of Everglades National park,only 2%of the original pine rocklands remain,and they are in the form of small *** objective is to investigate the effects of fragmentation and habitat quality on abun-dance and plant reproductive fitness of Angadenia berteroi(A.D.C.)Miers,a threatened species of the southern Florida pine *** We estimated the density of plants using a stratified random sam-pling design,and reproductive fitness(in terms of percentage of plants with flowers and fruit)by walking transects in an array of habitat fragments of different sizes and degrees of isolation(distance to the nearest fragment)as well as in continuous *** equation modeling(SEM)was employed to investigate how *** reproductive fitness was affected by fragmentation and habitat *** Findings Habitat fragment size was correlated with the density of ***,but did not have a great impact on its reproductive ***,habitat quality represented by litter depth and subcan-opy cover had strong negative effects on the reproductive fitness of ***,suggesting that increased light availability and low litter cover resulting from recent fires may favor reproduction.

关键词： habitat fragmentation habitat quality isolation fire structural equation modeling reproductive fitness abundance

MOS Capacitance-Voltage Characteristics:Ⅳ.Trapping Capacitance from 3-Charge-State Impurities

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Journal of Semiconductors 2012年第1期33卷 1-19页

作者： Jie Binbin sah Chihtang Department of physics Xiamen University Xiamen 361005China CTsah Associates GainesvilleFlorida 32605USA

Metal-Oxide-Semiconductor Capacitance-Voltage （MOSCV） characteristics containing giant carrier trapping capacitances from 3-charge-state or 2-energy-level impurities are presented for not-doped, n-doped, p- doped and compensated silicon containing the double-donor sulfur and iron, the double-acceptor zinc, and the amphoteric or one-donor and one-acceptor gold and silver impurities. These impurities provide giant trapping ca- pacitances at trapping energies from 200 to 800 meV （50 to 200 THz and 6 to 1.5 μm）, which suggest potential sub-millimeter, far-infrared and spin electronics applications.

关键词： multiple charge states trapping capacitance dopant impurity

Studies of Water V. Five phonons in protonic Semiconductor Lattice Model of pure Liquid Water

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Journal of Semiconductors 2017年第7期38卷 1-17页

作者： Binbin Jie Chihtang sah Department of physics Xiamen University Xiamen 361005 China Chinese Academy of Sciences Beijing 100864 China

We report physics based confirmation（~1% RMS deviation）, by existing experimental data, of protonprohol（proton-hole） ion product（p H） and mobilities in pure liquid water（0-100℃, 1-atm pressure） anticipated from our melted-ice Hexagonal-Close-packed（H_2O）_4Lattice Model. Five phonons are identified.（1） A propagating protonic phonon（520.9 meV from lone-pair-blue-shifted stretching mode of isolated water molecule） absorbed to generate a proton-prohol pair or detrap a tightly-bound proton.（2） Two（173.4 and 196.6 meV） bending-breathing protonic-proholic or protonic phonons absorbed during de-trapping-limited proton or proton-prohol mobilities.（3）Two propagating oxygenic-wateric Debye-Dispersive phonons（30.3 and 27.5 meV） absorbed during scatteringlimited proton or proton-prohol mobilities.

关键词： solid, soft and liquid material physics pure water point-mass positive proton and negative prohol pH proton-ion product and mobilities phonon scattering and detrapping-trapping of propagating-localized protons and prohols