Manisa Celal Bayar Üniversitesi Akademik Arşiv Sistemi
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Structural and optical properties of SrAl2O4: Eu2+/Dy3+ phosphors synthesized by flame spray pyrolysis technique
No full textIn this study Sr0.985Al2O4:0.005Eu(2+)/0.01Dy(3+) luminescent materials with long afterglow and high intensity were synthesized by flame spray pyrolysis (FSP) method for the first time. Precursor solution was divided into two separate part. One of the parts was used FSP process, the other one was dried to simulate sol- gel process. Thermal properties and organic content of FSP derived particles and dried gel were compared using DTA-TG and FTIR devices. FSP derived particles were sintered in argon medium at 1200 degrees C. Phase and elemental analysis of the final phosphors were carried out by X-Ray Diffraction (XRD) and X-Ray Photo electron Spectroscopy (XPS) measurements. Scanning electron microscopy (SEM) images were obtained to observe particle morphology. Optical properties of phosphor were determined by Photoluminescence (PL), thermoluminescence (TL) and radioluminescence (RL) measurements. The emission spectra of Sr0.985Al2O4: 0.005Eu(2+)/0.01Dy(3+) were composed by a green band at 525 nm at room temperature when it was excited by 350 nm light, assigned to anomalous luminescence originated by Eu2+ and Dy3+ in the host lattice. There were estimated peaks at around 90, 130, 170 and 200 degrees C under the main glow curve in the sample irradiated by X- ray and He- Ne laser (lambda(exc) = 632 nm). RL spectrum of Sr0.985Al2O4 : 0.005Eu(2+)/0.01Dy(3+) powders have four distinct emission peaks at around 527 nm, 576 nm, 667 nm, 753; nm and a comparatively weak emission band at about 846 nm
Pell-Lucas polynomial method for Volterra integral equations of the second kind
No full textThis paper introduces a Pell-Lucas collocation method for solving Volterra integral equations of the second kind. The proposed method employs collocation points and represents Pell-Lucas polynomials and their derivatives in matrix vector form. By utilizing this approach, Volterra integral equations are converted into a matrix equation, wherein the undetermined coefficients correspond to the Pell-Lucas coefficients. The effectiveness and efficiency of the proposed method are demonstrated through numerical examples, which yield accurate solutions. The accuracy of these solutions is further assessed using absolute and residual error analysis. Moreover, the obtained numerical results obtained via the Pell-Lucas collocation method are compared with analytical solutions in tables and figures, thus providing a comprehensive evaluation of the method's performance
Nonlinear optical absorption of ZnO doped with copper nanoparticles in the picosecond and nanosecond pulse laser field
No full textThe nonlinear absorption of nanocomposite layers based on ZnO implanted with Cu+ ions with an energy of 160 keV in implantation doses of 10(16) and 10(17) ions/cm(2) was investigated. The values of the nonlinear absorption coefficient were measured by the Z-scan method at a wavelength of 532 nm by use of nanosecond and picosecond laser pulses. Possible optical applications of these materials are discussed. (c) 2005 Optical Society of America
MAGNETIC FIELD AS A TOOL FOR ENHANCING β-LACTAMASE ACTIVITY
No full textbeta-Lactam antibiotics have been extensively employed in bacterial treatment ever since penicillin's groundbreaking discovery. Despite the proliferation of antibiotics in the pharmaceutical sector today, bacteria often evolve defense mechanisms. Chief among these is the production of beta-lactamase enzymes, which degrade beta-lactam antibiotics, representing a prevalent form of antibiotic resistance. Additionally, these antibiotics exhibit limited biodegradability, with only 20% breaking down naturally. Hence, finding effective methods to mitigate the presence of beta-lactam antibiotics is crucial in combating antibiotic pollution
Determination of Hydrazine at a Platinum Nanoparticle and Poly(Bromocresol Purple) Modified Carbon Nanotube Electrode
No full textBromocresol purple was polymerized electrochemically at a carbon nanotube modified glassy carbon electrode and platinum nanoparticles were doped on the polymer film by electrochemical reduction. The modified electrodes were characterized by electrochemical impedance spectroscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy. The oxidation of hydrazine was investigated at the platinum nanoparticle modified electrode in phosphate buffer. The results were compared with those obtained using other modified and bare electrodes. The best catalytic activity was obtained at the platinum nanoparticle modified electrode due to shift of the oxidation peak to more negative values and highest current. The peak potential and current for hydrazine were -445mV and 175.5 mu A, respectively. Linear calibration curves for hydrazine were obtained from 10 to 1000mM. The limits of detection and quantitation for hydrazine were 1.0 and 3.0mM, respectively
Impacts of using a piezo-mounted elastic fin energy harvester on the power production and heat transfer control in a ventilated cavity during turbulent forced convection
No full textPiezo-electric energy harvesters (PE-EH) are used in a variety of engineering applications due to their simplicity, ease of installation, compact structure, higher power density, and lower cost. In this study, a novel elastic PE-EH fin assembly within a ventilated cavity is proposed for thermal management and power production during forced convection in turbulent flow regimes by using finite element method with ALE. Impacts of Reynolds number (Re between 10,000 and 50,000), opening ratio (OR between 0.5 and 2), fin vertical placement (yf between -0.3H and 0.3H), and inlet port horizontal position (xi between 0 and 0.6H) on the characteristics of generated power and convective heat transfer are numerically assessed. Higher deflection of the elastic fin assembly and vortex size reduction at the fin tip are the outcomes of higher Re and OR values. The average Nu rises by about 135% for Re values between Re = 10,000 and Re = 30,000 but reduces by 55% between Re = 30,000 and Re = 50,000. Cooling performance is improved by 165% when OR variation is taken into account, going from the lowest value of OR to OR = 1.5. For generated power, the enhancement factors are 290 and 81 when values of Re and OR are raised from their lowest to highest levels. For cooling performance and generated power, the corresponding improvement factors are 6.94 and 2.5, respectively, from the lowest to the maximum value of the vertical position. Inlet and outlet port locations closer to the middle of the top and bottom wall provides the highest power generation from the PE-EH. There are 121% and 41% variations of generated power when inlet and outlet port locations are varied. An artificial neural network is used to assess the power generated by the PE-EH device using a three-input, one-output system
Distinctive sleep complaints and polysomnographic findings in antibody subgroups of autoimmune limbic encephalitis
No full textIntroduction Sleep disturbances are being increasingly recognized in association with autoimmune encephalitis (AIE). We investigated the prevalence of sleep-related symptoms and polysomnographic features of patients with AIE and the long-term outcomes in these patients in a multi-center, prospective study from Turkey.Methods We prospectively evaluated patients with definite AIE in a common database including demographics, AIE-related and sleep-related symptomatology. Maximum and latest modified Rankin scores (mRS) and Liverpool Outcome Score (LOS) were noted.Results Of 142 patients, 87 patients (61.3%) fulfilled the criteria for definite AIE (mean age, 46.8+18.8 years; 51.7% women; mean disease duration, 21.0+38.4 months). 78.9% of patients had at least one or more new onset or worsened sleep-related symptomatology: insomnia (55.3%), excessive daytime sleepiness (EDS, 28.0%), sleep apnea (18.7%), REM sleep behavior disorder (RBD, 17.3%), restless legs syndrome (10.7%) and oneiric stupor (9.3%). Sleep efficiency, N3 and REM sleep were decreased and N1 sleep was increased in patients with Ab[+] AIE. LOS points were highest in those with insomnia and sleep apnea, and lowest in those with EDS, RBD and oneiric stupor. RBD and sleep apnea were more common in anti-LG1 Ab[+] group than anti-NMDAR Ab[+] group. Index of periodic leg movements was highest in anti-LG1 Ab[+] group. Patients with EDS and oneiric stupor had more common memory problems. Maximum and latest mRS scores were positively correlated with EDS and oneiric stupor. EDS, RBD and oneiric stupor were negatively correlated with LOS points.Conclusion Our study emphasizes the presence and importance of early diagnosis of sleep disturbances in AIE in regard to their deteriorative influences on disease prognosis
A hybrid adaptive large neighbourhood search algorithm for the capacitated location routing problem
No full textThis paper proposes a new hybrid metaheuristic algorithm that is composed of the adaptive large neighbourhood search (ALNS) and the variable neighbourhood search (VNS) algorithms to tackle the location routing problem (LRP) with capacity constraints. The rationale of the proposed hybrid metaheuristic algorithm is to enhance the performance of the ALNS algorithm by incorporating the VNS algorithm as an elitist local search. Therefore, the diversification and intensification strategies of the proposed hybrid metaheuristic algorithm are realized via the ALNS and VNS algorithms, respectively. The performance evaluation tests of the proposed hybrid metaheuristic algorithm are performed on the three classical LRP benchmark sets taken from the related literature, and the obtained results are compared against some of the formerly proposed and published methods in terms of solution quality. Computational results indicate that the proposed hybrid metaheuristic algorithm has a satisfactory performance in solving the LRP instances and is a competitive algorithm
Experience with mesocaval shunt with autologous jugular vein interposition in patients with Budd-Chiari syndrome
No full textBackground/Aims: In the present era of interventional. radiology and liver transplantation, the role of mesocaval shunt surgery for portal hypertension in Budd-Chiari syndrome is reviewed. Methodology: This study analyzed the management of 35 patients with Budd-Chiari syndrome between June 1994 and June 2004 in our institution. During this 10-year interval, 31 of the 35 patients with Budd-Chiari syndrome underwent shunt procedures and four patients underwent liver transplantation. Mesocaval shunts were preferred in 27 patients and seven of these patients required prior caval stenting. One portocaval shunt was performed in a patient having a thrombosed mesocaval shunt. In all mesocaval. shunt procedures the patient's internal jugular vein was used as an interposition graft between the superior mesenteric vein and inferior vena cava. In four patients with thrombosed vena cava a mesoatrial shunt was performed using poly-tetrafluoroethylene graft while four patients with established cirrhosis under-went orthotopic liver transplantation. Results: In the group of mesocaval shunts, 3 patients were lost in the early postoperative period with a mortality rate of 11%, 2 of them due to thrombosed shunts and one of them due to pneumonia. The median follow-up was 42 months (6-120 months) and one patient experienced shunt thrombosis and died afterwards due to the complications of portal hypertension. In the whole series the patency rate of the mesocaval shunt was 89%. Conclusions: Patients with Budd-Chiari syndrome can be managed by a combination of shunt surgery, interventional radiology and liver transplantation. Our results demonstrate the effectiveness of mesocaval shunt procedure with autologous jugular vein interposition to maintain long-term patency and survival
Effect of growth hormone on small intestinal homeostasis relation to cellular mediators IGF-I and IGFBP-3
No full textAIM: To evaluate the effects of growth hormone (GH) on the histology of small intestines which might be related to the role of insulin like growth factor (IGF)-I, IGF-binding protein 3 (IGFBP-3) and its receptors. METHODS: Twelve week-old adult male Wistar albino rats were divided into two groups. The study group (n = 10), received recombinant human growth hormone (rGH) at a dose of 2 mg/kg per day subcutaneously for 14 d and the control group (n = 10) received physiologic serum. Paraffin sections of jejunum were stained with periodic acid shift (PAS) and hematoxylin and eosin (HE) for light microscopy. They were also examined for IGF-I, IGFBP-3 and IGF-receptor immunoreactivities. Staining intensity was graded semi-quantitatively using the HS-CORE. RESULTS: Goblet cells and the cells in crypt epithelia were significantly increased in the study group compared to that of the control group. We have demonstrated an increase of IGF-I and IGFBP-3 immunoreactivities in surface epithelium of the small intestine by GH application. IGF-I receptor immunoreactivities of crypt, villous columnar cells, enteroendocrine cells and muscularis mucosae were also more strongly positive in the study group compared to those of in the control group. CONCLUSION: These findings confirm the important trophic and protective role of GH in the homeostasis of the small intestine. The trophic effect is mediated by an increase in IGF-I synthesis in the small intestine, but the protective effect is not related to IGF-I. (C) 2009 The WIG Press and Baishideng. All rights reserved