http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Influence of polled direction on the stress distribution in piezoelectric materials
Nihat İlhan,Nagihan Koç 국제구조공학회 2015 Structural Engineering and Mechanics, An Int'l Jou Vol.54 No.5
In this paper, the influence of the polled direction of piezoelectric materials on the stress distribution is studied under time-harmonic dynamical load (time-harmonic Lamb’s problem). The system considered in this study consists of piezoelectric covering layer and piezoelectric half-plane, and the harmonic dynamical load acts on the free face of the covering layer. The investigations are carried out by utilizing the exact equations of motion and relations of the linear theory of electro-elasticity. The plane-strain state is considered. It is assumed that the perfect contact conditions between the covering layer and halfplane are satisfied. The boundary value problems under consideration are solved by employing Fourier exponential transformation techniques with respect to coordinates directed along the interface line. Numerical results on the influence of the polled direction of the piezoelectric materials such as PZT-5A, PZT-5H, PZT-4 and PZT-7A on the normal stresses, shear stresses and electric potential acting on the interface plane are presented and discussed. As a result of the analyses, it is established that the polled directions of the piezoelectric materials play an important role on the values of the studied stresses and electric potential.
Omer KISI,Nagihan Ustunsoy,Mehmet Gurdal 원광대학교 기초자연과학연구소 2023 ANNALS OF FUZZY MATHEMATICS AND INFORMATICS Vol.25 No.3
We introduce the idea of gradually $\left( \lambda ,\mu \right) $-statistical convergence with regards to the $n$-norm in gradual $n$-normed linear space (GN$n$LS) in this study. We look at certain inclusion relations with regards to the $n$-norm between the sets of gradually statistically convergent and gradually $\left( \lambda ,\mu \right) $-statistically convergent double sequences. We discover its relationship to gradually strongly Cesaro summability, gradually strongly $\left( V,\lambda ,\mu \right) $-summability, and gradually statistical convergence with regards to the $n$-norm in GN$n$LS.
( Emel Kiyak Caglayan ),( Yaprak Engin Ustun ),( Nagihan Sari ),( Seyhan Karacavus ),( Levent Seckin ),( Mustafa Kara ) 대한폐경학회 2015 대한폐경학회지 Vol.21 No.1
Objectives: The aim of the study was to compare bone mineral density (BMD) in healthy postmenopausal women to BMD in type 2 diabetic hypertensive postmenopausal women with hyperlipidemia. Methods: Fifty type 2 diabetic and hypertensive postmenopausal women with hyperlipidemia and 51 age and body mass index (BMI) matched healthy postmenopausal women were included. Lumbar spine and femoral neck BMD were noted in both groups. BMD was measured using dual energy X-ray absorptiometry (DXA). Serum alkaline phosphatase (ALP), calcium and phosphorous were also measured. Pearson correlation coefficients were used to establish the relationship between various clinical characteristics. Results: There were no significant differences between two groups in respect to lumbar and vertebral BMD values, age, BMI, gravidity, parity. Serum cholesterol and fasting glucose levels were significantly different between each groups (P = 0.0001, P = 0.002). Conclusion: We found that, accompanying chronic diseases such as diabetes, hypertension and hyperlipidemia don’t affect the BMD measurements at postmenopausal period. So these postmenopausal women don’t have excess risk regarding osteoporosis. (J Menopausal Med 2015;21:36-40)
Faiz, Ozlem,Colak, Ahmet,Saglam, Nagihan,Canakci, Sabriye,Belduz, Ali Osman Korean Society for Biochemistry and Molecular Biol 2007 Journal of biochemistry and molecular biology Vol.40 No.4
A novel hot spring thermophile, Anoxybacillus gonensis A4 (A. gonensis A4) was investigated in terms of capability of tributyrin degradation and characterization of its thermostable esterase activity by the hydrolysis of p-nitrophenyl butyrate (PNPB). It was observed that A. gonensis A4 has an esterase with a molecular weight of 62 kDa. The extracellular crude preparation was characterized in terms of substrate specificity, pH and temperature optima and stability, kinetic parameters and inhibition/activation behaviour towards some chemicals and metal ions. Tributyrin agar assay showed that A. gonensis A4 secreted an esterase and $V_{max}$ and $K_m$ values of its activity were found to be 800 U/L and 176.5 ${\mu}M$, respectively in the presence of PNPB substrate. The optimum temperature and pH, for A. gonensis A4 esterase was $60-80^{\circ}C$ and 5.5, respectively. Although the enzyme activity was not significantly changed by incubating crude extract solution at $30-70^{\circ}C$ for 1 h, the enzyme activity was fully lost at $80^{\circ}C$ for same incubation period. The pH-stability profile showed that original crude esterase activity increased nearly 2-fold at pH 6.0. The effect of some chemicals on crude esterase activity indicated that A. gonensis A4 produce an esterase having serine residue in active site and -SH groups were essential for its activity.
Neda Kalantari,Maged F. Bekheet,Parastoo Delir Kheyrollahi Nezhad,Jan O. Back,Ali Farzi,Simon Penner,Nagihan Delibas,Sabine Schwarz,Johannes Bernardi,Dariush Salari,Aligholi Niaei 한국공업화학회 2022 Journal of Industrial and Engineering Chemistry Vol.111 No.-
We introduced chromium and boron into the hierarchical structure of ZSM-5 by following an incipientwet impregnation and hydrothermal synthesis approach to enhance the performance of the catalystsin the methanol-to-propylene process. Crystal structure, preferred orientation, and crystal symmetry ofsynthesized zeolites were discussed using Rietveld refinement and revealed that all synthesized zeolitescrystallized in a monoclinic structure, whereas the boron-incorporated sample exhibited an orthorhombicsymmetry. Large-scale defect-free single-crystalline structures of hierarchical zeolite created by CTABand F127 mesoporogens are confirmed by electron microscopy and magic angle spinning nuclear magneticresonance (MAS NMR). The formation of surface metal oxides and extra-framework metal oxidescaused changes in the electronic structure of the components as visible in Si 2p and O 1s spectra. The predominantpresence of OH groups and the higher Cr (VI) /Cr (III) ratio account for the better performanceof impregnated chromium-ZSM-5 especially in the production of light olefins. The introduction of boronby impregnation further preserved the preferred growth orientation, hierarchical structure with highcrystallinity and caused surface acidity changes in favor of increasing propylene selectivity to 67% witha propylene/ethylene ratio of close to 8.