检索结果-南通市图书馆

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

在线全文

学校读者我要写书评

暂无评论

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

在线全文

学校读者我要写书评

暂无评论

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

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

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

Ultrastructural view of colon anastomosis under propolis effect by transmission electron microscopy

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2008年第30期14卷 4763-4770页

作者： Sibel Serin Kilicoglu Bulent Kilicoglu esra Erdemli Department of Histology and Embryology Ufuk University School of Medicine 4th General Surgery Department Ankara Training and Research Hospital Department of Histology and Embryology Ankara University School of Medicine

AIM： To evaluate the effect of propolis administration on the healing of colon anastomosis with light and transmission electron microscopes. METHODS： Forty-eight Wistar-AIbino female rats were divided into two groups and had colon resection and anastomosis. In group Ⅰ, rats were fed with standard rat chow pre- and postoperatively. The rats in group Ⅱ were fed with standard rat chow and began receiving oral supplementation of propolis 100 mg/kg per day beginning 7 d before the operation and continued until they were sacrificed. Rats were sacrificed 1, 3, 7 and 14 d after operation, and anastomotic bursting pressures measured. After the resection of anastomotic segments, histopathological examination was performed with light and transmission electron microscopes by two blinded histologists and photographed. RESULTS： The colonic bursting pressures of the propolis group were statistically significantly better than the control group. UItrastructural histopathological analysis of the colon anastomosis revealed that propotis accelerated the phases of the healing process and stimulated mature granulation tissue formation and collagen synthesis of fibroblasts. CONCLUSION： Bursting pressure measurements and ultra structural histopathological evaluation showed that administration of propolis accelerated the healing of colon anastomosis following surgical excision.

关键词： Propolis Wound healing Colon anastomosis Histopathology Transmission electron microscope

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

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

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

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

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

Effectiveness of an educational program on improving healthcare providers' knowledge of acute stroke: A randomized block design study

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Emergency Medicine 2021年第2期12卷 93-98页

作者： Jehad A.Rababah Mohammed MAl-Hammouri esra’a AlNsour Jordan University of Science and Technology Faculty of NursingIrbid 22110Jordan Prince Al Hussein Bin Abdullah II Academy for Civil Protection Amman 11511Jordan

BACKGROUND: Stroke is a time-sensitive neurological disease and a life-threatening medical condition. Providing timely management for stroke patients is a crucial issue in healthcare settings. The primary objective of this study is to evaluate the effectiveness of an evidence-based educational program on healthcare providers'(HCPs) overall knowledge of ***: A randomized block design with post-test only was used. A total of 189 HCPs(physicians, registered nurses, and paramedics) involved with treating stroke patients in the emergency were recruited. Participants were randomly assigned to either the intervention or waiting list control group. A one-session, stroke educational program was offered to the HCPs followed by a post-test designed to assess knowledge about stroke. RESULTS: A significant main effect on the profession type was found, with physicians having higher mean scores of stroke knowledge compared with nurses and paramedics(F [2, 183]=48.55, P<0.001). The implemented educational program had a positive effect on increasing the level of stroke knowledge among HCPs(F [1, 183]=43.31, P<0.001). The utilization of any evidence-based assessment tools for patients with suspected stroke was denied by 36% of the total ***: The implemented intervention can increase HCP's knowledge regarding stroke. Stroke education should be considered as one of the essential requirements for professional development for all HCPs in the emergency.

关键词： Stroke Misdiagnosis Healthcare providers'knowledge Stroke knowledge

MOTIONS OF CURVES IN THE GALILEAN SPACE G_3

在线全文

学校读者我要写书评

暂无评论

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

Suitability and assessment of the dams water for the purpose of agricultural irrigation

在线全文

学校读者我要写书评

暂无评论

International Journal of Agricultural and Biological Engineering 2023年第6期16卷 255-262页

作者： Barış Bülent Aşık esra Bozan Kapdı Bursa Uludag University Faculty of AgricultureDepartment of Soil Science and Plant NutritionBursaTurkey Bursa Uludag University Graduate School of Natural and Applied ScienceBursaTurkey

This study was carried out to evaluate the water quality of selected dam lakes as well as their suitability for agricultural *** dams were selected for water sampling and samples were collected monthly,including during the irrigation season for a period of one year from March to September *** samples were analyzed for temperature,pH,physicochemical parameters such as temperature,pH value,salinity(EC),anions(CO_(3),HCO_(3),CI,SO_(4),P,NO_(3)),cations(Na,K,Ca,Mg,B,NH_(4))and heavy *** irrigation suitability assessment was made using various indices such as SAR(sodium adsorption rate),TDS(total dissolved solids),Na%(sodium percentage),RSC(residual sodium bicarbonate),MAR(magnesium adsorption rate),KR(Kelly ratio),and PI(permeability index).The temperature values of the water samples varied between 5.8℃-25.1℃,pH and EC values changed between 7.51 and 8.46,282,and 1400μS/cm *** water samples were evaluated as C_(2)S_(1) and C_(3)S_(1) irrigation water *** heavy metal contents of the water samples were determined below the limit *** dams were found suitable for irrigation in terms of EC(salinity),SAR(sodium adsorption rate),TDS(total dissolved solids),Na%(sodium percentage),RSC(residual sodium bicarbonate),MAR(magnesium adsorption rate),and KR(Kelly ratio).Water samples were determined as the second class of PI(permeability index).Güllübağdam was not found suitable as irrigation water in terms of EC,Na%,RSC,and KR *** a result,it specifically points to the restrictions on the use of water from the Güllübağdam for irrigation purposes.

关键词： anions cations irrigation water water quality