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Projectively Ricci-flat General(α,β)-metrics

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Acta Mathematica Sinica,English Series 2024年第6期40卷 1409-1419页

作者： esra Sengelen SEVIM Department of Mathematics Istanbul Bilgi University34060Eski Silahtaraga Elektrik SantraliKazim Karabekir Cad.No:2/13 EyupsultanIstanbulTurkey

In this paper,we study the projectively Ricci-flat general(α,β)-metrics within to a spray framework and also bring out the rich variety of behaviour displayed by an important projective *** Ricci curvature is one of the essential projective invariant in Finsler geometry which has been introduced by *** projective Ricci curvature is defined as Ricci curvature of a projective spray associated with a given spray G on M^(n) with a volume form dV on M^(n).

关键词： Finsler metrics general(α β)-metrics projective Ricci curvature

Effects of precommercial thinning on growth parameters in Pinus nigra ***(Lamb.)Holmboe stand

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Journal of Forestry Research 2020年第5期31卷 1803-1811页

作者： esra Bayar Ayse Deligoz Department of Forestry Engineering Faculty of ForestryIsparta University of Applied SciencesIsparta 32260Turkey

We investigated the effects of precommercial thinning(PCT)applied at different levels on the growth parameters of natural Anatolian black pine *** experimental site was located in the province of Isparta in southern *** was set up using a randomized complete block design with three replicates and three treatments(control,2–2.5 m×–2.5 m and 3–3.5 m×–3.5 m spacing).The experimental plots were established in March *** the end of the growing seasons for three years(2014–2016),growth parameters such as diameter,height and crown radius were *** was found to be significantly effective on diameter,height,individual tree basal area,and crown radius increment at the end of the third year(p<0.05).While diameter,individual tree basal area and crown radius increment increased with increasing PCT intensity,height increment was higher in control than *** the PCT treatments applied with 3–3.5 m spacing affected individual tree development positively,we need long-term results on wood quality and *** to the short-term results,it is thought that it is better to lower the stand closeness gradually,so,it may be advisable to apply PCT by 2–2.5 m×–2.5 m spacing.

关键词： Precommercial thinning Anatolian black pine Diameter increment Height increment

Binding energy of the donor impurities in GaAs-Ga_(1-x)Al_xAs quantum well wires with Morse potential in the presence of electric and magnetic fields

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Chinese Physics B 2016年第10期25卷 39-44页

作者： esra Aciksoz Orhan Bayrak Asim Soylu Department of Physics Akdeniz University Department of Physics Nigde University

The behavior of a donor in the GaAs–GaAlAs quantum well wire represented by the Morse potential is examined within the framework of the effective-mass approximation. The donor binding energies are numerically calculated for with and without the electric and magnetic fields in order to show their influence on the binding energies. Moreover, how the donor binding energies change for the constant potential parameters(De, re, and a) as well as with the different values of the electric and magnetic field strengths is determined. It is found that the donor binding energy is highly dependent on the external electric and magnetic fields as well as parameters of the Morse potential.

关键词： Morse potential electric field magnetic field the donor atom quantum well wire

Synthesis and Structural Studies of 6-(2,5-Dimethyl-1H-pyrrol-1-yl)pyridin-2-amine

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Chinese Journal of Structural Chemistry 2010年第5期29卷 720-725页

作者： SAHN Zarife Sibel KARABCEK Serdar SENSES esra KARABCEK esra ISIK Samil Department of Physics Faculty of Arts and SciencesOndokuz Mayιs University Department of Chemistry Faculty of Arts and SciencesKaradeniz Technical University

6-（2,5-Dimethyl-1H-pyrrol-1-yl）pyridin-2-amine （1） was synthesized and characte-rized by elemental analyses,1H-NMR and 13C-NMR,FTIR,Uv-Vis,mass spectral studies and single-crystal X-ray *** data obtained from spectral studies support the structural properties of *** N-H…N hydrogen bonds produce an R22（8） *** extensive three-dimensional network formed by C-H…π and N-H…π-facial hydrogen bonds is responsible for the crystal *** combination of C-H…π interactions produces R33（12）,R43（19） and R44（20） rings.

关键词： 2,6-diaminopyridine Schiff bases methylpyridine pyrrol

Speech Separation Methodology for Hearing Aid

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Computer Systems Science & Engineering 2023年第2期44卷 1659-1678页

作者： Joseph Sathiadhas esra Y.Sukhi Meenakshi Sundararajan Engineering College ChennaiTamil naduIndia R.M.K.Engineering College KavaraipettaiTamil naduIndia

In the design of hearing aids(HA),the real-time speech-enhancement is *** digital hearing aids should provide high signal-to-noise ratio,gain improvement and should eliminate *** generic hearing aids the perfor-mance towards different frequencies varies and non *** noise can-cellation and speech separation methods drops the voice magnitude under the noise *** performance of the HA for frequency response is non *** noise suppression methods reduce the required signal strength ***,the performance of uniform sub band analysis is poor when hearing aid is *** this paper,a speech separation method using Non-negative Matrix Fac-torization(NMF)algorithm is proposed for wavelet *** Proposed non-uniformﬁlter-bank was validated by parameters like band power,Signal-to-noise ratio(SNR),Mean Square Error(MSE),Signal to Noise and Dis-tortion Ratio(SINAD),Spurious-free dynamic range(SFDR),error and *** speech recordings before and after separation was evaluated for quality using objective speech quality measures International Telecommunication Union-Telecommunication standard ITU-T P.862.

关键词： Speech separation waveletﬁlter independent component analysis(ICA) non-negative matrix factorization(NMF) fejer-korovkin(FK) signal-to-noise ratio(SNR)

A study on the seismic behavior of a retrofitted building based on nonlinear static and dynamic analyses

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Earthquake Engineering and Engineering Vibration 2005年第1期4卷 173-180页

作者： esra Mete Güneyisi Gülay Altay Department of Civil Engineering Bo■azi■i University Bebek ■stanbul TurkeyResearchAssistantDepartment of Civil Engineering Bo■azi■i University Bebek ■stanbul Turkey Professor

This study describes the seismic performance of an existing five storey reinforced concrete building which represents the typical properties of low-rise non-ductile buildings in Turkey. The effectiveness of shear walls and the steel bracings in retrofitting the building was examined through nonlinear static and dynamic analyses. By using the nonlinear static analysis, retrofitted buildings seismic performances under lateral seismic load were compared with each other. Moreover, the performance points and response levels of the existing and retrofitting cases were determined by way of the capacity-spectrum method described in ATC-40 (1996). For the nonlinear dynamic analysis the records were selected to represent wide ranges of duration and frequency content. Considering the change in the stiffness and the energy dissipation capacities, the performance of the existing and retrofitted buildings were evaluated in terms of story drifts and damage states. It was found that each earthquake record exhibited its own peculiarities, dictated by frequency content, duration, sequence of peaks and their amplitude. The seismic performance of retrofitted buildings resulted in lower displacements and higher energy dissipation capacity depending mainly on the properties of the ground motions and the retrofitting strategies. Moreover, severe structural damage (irreparable or collapse) was observed for the existing building. However, buildings with retrofit alternatives exhibited lower damage levels changing from no damage to irreparable damage states.

关键词： nonlinear static analysis nonlinear time history analysis performance level retrofitting shear wall steel bracing

Minimizing FWM Impact in DWDM ROF DP-DQPSK System for Optical

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Computers, Materials & Continua 2023年第4期75卷 1033-1050页

作者： esra Ehsan Razali Ngah Nurul Ashikin Binti Daud Wireless Communication Centre School of Electrical EngineeringUniversiti Teknologi Malaysia Johor BahruMalaysia

The demonstration of a higher data rate transmission system was amajor aspect to be considered by researchers in recent years. The most relevantaspect to be studied and analyzed is the need for a reliable system to handlenonlinear impairments and reduce them. Therefore, this paper examines theinfluence of Four-Wave Mixing (FWM) impairment on the proposed highdata rate Dual polarization–Differential Quadrature phase shift keying (DPDQPSK)system using the Optisystem software. In the beginning, the impactof varied input power on the proposed system’s performance was evaluated interms of QF and BER metrics. More power is used to improve system ***, increasing power would raise theFWMeffects. Accordingly,a−10dBminput power and the proposed system are used to reduce the impactof FWM. Additionally, a hybrid amplification method is proposed to enhancesystem performance by utilizing the major amplification methods of erbiumdopedfiber amplifier (EDFA): semiconductor optical amplifier (SOA) andRadio optical amplifier (ROA). The evaluation demonstrates that the OAEDFAoutperformed the other two key amplification techniques of (EDFASOA)and (EDFA-ROA) in improving Quality factor (QF) and Bit error rate(BER) system results for all distances up to 720 km. Consequently, the methodcontributes to minimizing the impact of FWM. In the future, other forms ofnonlinearity will be investigated and studied to quantify their impact on theproposed system.

关键词： Direct detection DQPSK bit error rate quality factor Dense wavelength division multiplexing(DWDM)

COVID-19:Gastrointestinal manifestations,liver injury and recommendations

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World Journal of Clinical Cases 2022年第4期10卷 1140-1163页

作者： Zulal Ozkurt esraÇınar Tanrıverdi Department of Infectious Disease Atatürk UniversitySchool of MedicineErzurum 25100Turkey Department of Medical Education Atatürk UniversitySchool of MedicineErzurum 25100Turkey

Coronavirus disease 2019(COVID-19)has caused a pandemic that affected all countries with nearly 270 million patients and 5 million deaths,as of as of December,*** severe acute respiratory syndrome coronavirus 2 virus targets the receptor,angiotensin-converting enzyme 2,which is frequently found in human intestinal epithelial cells,bile duct epithelial cells,and liver cells,and all gastrointestinal system organs are affected by COVID-19 *** aim of this study is to review the gastrointestinal manifestations and liver damage of COVID-19 infection and investigate the severe COVID-19 infection risk in patients that have chronic gastrointestinal disease,along with current treatment guidelines.A literature search was conducted on electronic databases of PubMed,Scopus,and Cochran Library,consisting of COVID-19,liver injury,gastrointestinal system findings,and *** and intestinal involvements are the most common ***,anorexia,nausea/vomiting,abdominal pain are the most frequent symptoms seen in intestinal *** hepatitis occurs with elevated levels of *** involvement is associated with long hospital stay,severity of the disease,and intensive care unit *** and follow-up of patients with inflammatory bowel diseases,cirrhosis,hepatocellular carcinoma,or liver transplant have been negatively affected during the *** with cirrhosis,hepatocellular carcinoma,auto-immune diseases,or liver transplantation may have a greater risk for severe *** or therapeutic procedures should be restricted with specific *** should be used in non-urgent periodic patient follow ***-19 treatment should not be delayed in patients at the risk ***-19 vaccination should be prioritized in this group.

关键词： COVID-19 Gastrointestinal manifestations Liver injury Liver transplantation SARS-CoV-2

MOTIONS OF CURVES IN THE GALILEAN SPACE G_3

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Acta Mathematica Scientia 2015年第5期35卷 1046-1054页

作者： Ufuk OZTURK Suleyman CENGIZ esra Betul KOC OZTURK Department of Mathematics Faculty of Science ank?r? Karatekin University

In this article, we study the flows of curves in the Galilean 3-space and its equiform geometry without any constraints. We find that the Frenet equations and the intrinsic quantities of the inelastic flows of curves are independent of time. We show that the motion of curves in the Galilean 3-space and its equiform geometry are described by the inviscid and viscous Burgers＇ equations.

关键词： Galilean geometry equiform geometry motions of curves inextensible flows Burgers' equation Frenet frames