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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

Surgical Treatment of Osteonecrosis of the Femoral Head Using Minimally Invasive Surgical Drilling and Cancellous Grafting at Brazzaville University Hospital

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Open Journal of Orthopedics 2024年第2期14卷 122-132页

作者： Kevin parfait Bienvenu Bouhelo-pam Marius Monka Arnauld Sledje Wilfrid Bilongo Bouyou Regis perry Massouama paul Yèlai Ikounga Roger Bertrand sah Mbou Armand Moyikoua Department of Orthopaedic surgery and Traumatology University Hospital of Brazzaville Brazzaville Republic of the Congo Faculty of Health Sciences Marien N’GOUABI University Brazzaville Republic of the Congo

Introduction: Osteonecrosis of the femoral head (ONTF) is a debilitating condition. Several treatments have been proposed with controversial results. The aim of our study was to evaluate treatment by surgical drilling coupled with in situ cancellous grafting. Materials and methods: Our study was a case-control study conducted at Brazzaville University Hospital from 1st January 2018 to 31 December 2023. It compared two groups of patients with ONTF: non-operated (13 patients, 20 hips) and operated (22 patients, 35 hips). We used the visual digital scale (VDS) for pain assessment, the Merle D’Aubigne-postel (MDp) scoring system for clinical and functional assessment, and the evolution of necrosis. Results: The group of non-operated patients had a mean age of 35.69 ± 3.4 years, no improvement in pain with an EVN above seven at the last recoil and a mean global MDp score falling from 12.7 before offloading to 10.13 at one year. The group of patients operated on had a mean age of 37.86 ± 7.02 years, a significant reduction in pain (p = 0.00004) and a significantly increased MDp score (p = 0.0034). A comparison of the two groups of patients showed significant stabilization of the necrotic lesions in the operated patients (p = 0.00067), with better satisfaction in the same group. Conclusion: Surgical drilling combined with grafting in the treatment of early-stage ONTF has improved progress in our series. The technique is reproducible and less invasive. It has made it possible to delay unfavorable progression and, consequently, hip replacement surgery.

关键词： Hip Osteonecrosis of the Femoral Head Conservative Treatment Surgical Drilling Bone Grafting

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

Reoperation for early postoperative complications after gastric cancer surgery in a Chinese hospital

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World Journal of Gastroenterology 2010年第1期16卷 98-103页

作者： Birendra Kumar sah Department of General Surgery Ruijin HospitalShanghai Jiaotong UniversitySchool of MedicineShanghai Institute of Digestive Surgery

AIM:To investigate the occurrence of postoperative complications of gastric cancer surgery,and analyze the potential causes of reoperation for early postoperative complications. METHODS:A total of 1639 patients who underwent radical or palliative gastrectomies for gastric cancer were included in the *** study endpoint was the analysis of postoperative complications in inpatients. RESULTS:About 31%of patients had early postoperative complications,and complications of infection occurred most ***-abdominal hemorrhage and anastomotic leak were the main causes of reoperation,which accounted for about 2.2%.Mortality was 11.1%in the reoperation group,but was only 0.8%in other *** duration of postoperative stay in hospital was significantly longer and the total expenditure was markedly higher in the patients who underwent reoperation(pperation significantly increases the mortality rate and raises the burden of the surgical *** prospective studies are required to explore the potential risk factors.

关键词： Reoperation Gastric cancer Surgery postoperative complications

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

Does testosterone prevent early postoperative complications after gastrointestinal surgery?

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World Journal of Gastroenterology 2009年第44期15卷 5604-5609页

作者： Birendra Kumar sah Department of General Surgery&Shanghai Institute of Digestive Surgery Rui Jin HospitalShanghai Jiao Tong UniversitySchool of Medicine

AIM:To investigate the role of sex hormones in the early postoperative complications of gastrointestinal diseases. METHODS:A total of 65 patients who underwent operations for gastric and colorectal diseases(mainly malignant diseases)were included in the study. peripheral venous blood samples were collected at different times for analysis of estradiol,testosterone and *** only study endpoint was analysis of postoperative complications. RESULTS:patients of both sexes were uniform but postoperative complication rate was significantly higher in female patients(p=0.027).There was no significant association of estradiol and progesterone with postoperative *** levels in complicated patients were significantly lower than in uncomplicated patients(pperating characteristic curve showed that a lower value of testosterone was a predictor for higher complication rate(ppredictor of complications. CONCLUSION:patients with low testosterone level were prone to higher postoperative complications,which was evident in both ***,further studies are necessary to support this result.

关键词： Stomach neoplasms Testosterone Sex differences postoperative complications

A rare case of langerhans cell histiocytosis of the gastrointestinal tract

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World Journal of Gastroenterology 2012年第12期18卷 1410-1413页

作者： Uday Shankar Monika prasad om p Chaurasia Internal Medicine Mount Sinai School of Medicine at Queens Hospital CenterJamaicaNY 11432United States Department of Medicine University of CaliforniaIrvineCA 92697United States

Langerhans cell histiocytosis （LCH） is a group of idiopathic disorders characterized by the proliferation of specialized, bone marrow-derived langerhans cells and mature eosinophils. The clinical spectrum ranges from an acute, fulminant, disseminated disease called Letterer Siwe disease to solitary or few, indolent and chronic lesions of the bone or other organs called eosinophilic granuloma. Involvement of the gastrointestinal tract is very rare in LCH. We present the case of a 53-year-old woman referred by her primary care physician for a screening colonoscopy. A single sessile polyp, measuring 4 mm in size, was found in the rectum. Histopathological examination revealed that the lesion was relatively well circumscribed and comprised mainly a mixture of polygonal cells with moderate-to-abundant pink slightly granular cytoplasm. The nuclei within these cells had frequent grooves and were occasionally folded. Immunohistochemical staining was positive for CD la which confirmed the diagnosis of LCH. On further workup, there was no evidence of involvement of any other organ. On follow up colonoscopy one year later, there was no evidence of disease recurrence. Review of the published literature revealed that LCH presenting as solitary colonic polyp is rare. However, with the increasing rates of screening colonoscopy, more colonic polyps may be identified as LCH on histopathology. This underscores the importance of recognizing this rare condition and ensuring proper follow-up to rule out systemic disease.

关键词： Langerhans cells Histiocytosis Colonic pol-yp CD-la Eosinophilic granuloma Screening Colono-scopy