458 research outputs found

    A Spectral Solenoidal-Galerkin Method for Rotating Thermal Convection between Rigid Plates

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    The problem of thermal convection between rotating rigid plates under the influence of gravity is treated numerically. The approach uses solenoidal basis functions and their duals which are divergence free. The representation in terms of the solenoidal bases provides ease in the implementation by a reduction in the number of dependent variables and equations. A Galerkin procedure onto the dual solenoidal bases is utilized in order to reduce the governing system of partial differential equations to a system of ordinary differential equations for subsequent parametric study. The Galerkin procedure results in the elimination of the pressure and is facilitated by the use of Fourier-Legendre spectral representation. Numerical experiments on the linear stability of rotating thermal convection and nonlinear simulations are performed and satisfactorily compared with the literature

    Constraints on Non-Commutative Physics Scale with Neutrino-Electron Scattering

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    Neutrino-electron scatterings (νe\nu - e) are purely leptonic processes with robust Standard Model (SM) predictions. Their measurements can therefore provide constraints to physics beyond SM. Non-commutative (NC) field theories modify space-time commutation relations, and allow neutrino electromagnetic couplings at the tree level. Their contribution to neutrino-electron scattering cross-section was derived. Constraints were placed on the NC scale parameter ΛNC\Lambda_{NC} from νe\nu - e experiments with reactor and accelerator neutrinos. The most stringent limit of ΛNC>3.3TeV\Lambda_{NC} > 3.3 TeV at 95% confidence level improves over the direct bounds from collider experiments.Comment: 6 pages, 2 figures, 2 tables, V2: minor revisions to match published versio

    A novel index in healthy infants and children — subarachnoid space: ventricle ratio

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    Background: The subarachnoid space (SAS) and ventricular width (VW) in normalinfants and children were studied with ultrasonography to provide the objectivemeasurement and define a normal range for these measurements. The additional aim was to determine the stable ratio as a SAS/VW.Materials and methods: A total of 100 healthy subjects, including 48 males and52 females, were studied. The cases were divided into 3 age groups: 0–6 months(n = 65), 7–12 months (n = 24) and > 13 months (n = 11). Transfontanel ultrasonography was performed in all the cases. SAS, VW and the SAS/VW ratios were calculated. The study was approved by the ethical committee. All parents wereinformed about the sonographic examination and their approvals were taken.Results: SAS was calculated as 3.1 (0.5–6) mm and VW was calculated as 3.6(1.3–5) mm. SAS/VW ratio was 0.9 ± 0.3. There was no statistically significant difference among SAS, VW and SAS/VW ratios in 3–97 percentile group (p > 0.05).Conclusions: Ultrasonography can be used as a practicable and reproducible modalityin the measurement of SAS and VW in healthy children. It is a non-invasivemethod and allows for serial follow-up. SAS/VW ratio can be used as an index inhealthy children

    Phenological observations belonging to vegetation period of some native and exotic plant species in KTU Kanuni campus

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    It is possible to determine specific periods in plants during the vegetation period making phenological observations. When making phenological observations, one can be collect information about occurrence time of some events, such as sowing, germination and bud bursting. Particularly, this evidence will contribute s to the selection of species in site conditions, when making decisions about the species to be left in the field. Therefore, it is important to know blossoming time and lifespan of flowers during the seasons. If coloration of the plants to be used in the landscape design is known to depend on the season, much better compositions with the plants can be created. The aim of the paper is to reveal the differences in the beginning of vegetation of some native and exotic plant species found in the campus of Karadeniz Technical University. In this study, bud bursting times of 19 species of bud bursting dates, including 10 native trees, 5 exotic trees, 2 native shrubs and 2 exotic shrub species were investigated during the 4 phases. Thus, when observations were made for the times from swelling of the buds to the completion of the bud burst, it appeared that the bursting period for Acer platanoides L. was completed in the longest time and those for Carpinus betulus L. and Liquidambar orientalis Mill. – over the shortest time from the native species. The same period for Wisteria sinensis (Sims) DC. was completed in the longest time, while for Prunus serrulata Lindl. «Kandzan» it was completed in the shortest time for the exotic species

    Distribution, frequency and occurrence of cereal nematodes on the Central Anatolian Plateau in Turkey and their relationship with soil physicochemical properties

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    The distribution of important plant-parasitic and free-living nematodes in the cereal production areas of the Central Anatolian Plateau (CAP) of Turkey was investigated with systematic surveys. Two important plant-parasitic nematode groups were found widely distributed; cereal-cyst nematodes (78.3%) and root-lesion nematodes (42.6%). Cereal cyst nematodes (CCN) were identified as Heterodera filipjevi in 18 provinces. Heterodera latipons was found in only one province. Pratylenchus thornei and P. neglectus were the most widely distributed species of root-lesion nematodes. Other frequently recorded plant-parasitic nematodes belonged to the genera Geocenamus (52.4%), Pratylenchoides (35.6%), Helicotylenchus (29.7%) and Paratylenchus (19.2%). Konya on the southern CAP had a significantly high incidence of P. neglectus as well as free-living nematodes. The incidence of CCN was greatest in areas of sandy soils on the CAP, with densities of up to 95 cysts (100 g soil)-1. Population densities of Geocenamus, Pratylenchus and Pratylenchoides were high in some locations. Soil physicochemical properties were investigated for their relationship to nematode distribution. There was a slight positive correlation of P. thornei and clay content; conversely, there was a significant negative correlation of P. neglectus with clay and a positive correlation with sand. Electrical conductivity (EC) was positively correlated with P. neglectus. Nematodes in the genera Helicotylenchus, Paratylenchus, Trophurus and Tylenchorhynchus were only recorded at low population densities in the sampled area. By contrast, nematodes in the genera Aphelenchus, Aphelenchoides, Ditylenchus, Dorylaimus, Tylenchus and bacterivorous genera had relatively high populations. Total free-living nematodes were positively correlated with EC and zinc (Zn) concentration. The Zn content of soil was generally at a level deficient for plant growt

    trans-rac-[1-Oxo-2-phenethyl-3-(2-thien­yl)-1,2,3,4-tetra­hydro­isoquinolin-4-yl]methyl 4-methyl­benzene­sulfonate

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    The title compound, C29H27NO4S2, was synthesized by reaction of trans-rac-4-(hydroxy­meth­yl)-2-phenethyl-3-(thio­phen-2-yl)-3,4-dihydro­isoquinolin-1(2H)-one and 4-methyl­benzene-1-sulfonyl chloride in the presence of Et3N in CH2Cl2. The relative orientations of the benzene ring (A) of the 3,4-dihydro­isoquinolinone ring system, the thio­phene ring (B), the benzene ring (C) of the methyl­benzene group and the phenyl ring (D) result in the following dihedral angles: A/B = 80.91 (16), A/C = 22.79 (18), A/D = 9.9 (2), B/C = 80.73 (19), B/D = 88.9 (2) and C/D = 29.9 (2)°. The crystal structure is stabilized by weak inter­molecular C—H⋯O hydrogen bonds and C—H⋯π inter­actions

    Methyl trans-rac-2-hexyl-1-oxo-3-(2-pyrid­yl)-1,2,3,4-tetra­hydroisoquinoline-4-carboxyl­ate

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    The title compound, C22H26N2O3, was synthesized by esterification of trans-rac-2-hexyl-1-oxo-3-(2-pyrid­yl)-1,2,3,4-tetra­hydro­isoquinoline-4-carboxylic acid in the presence of H2SO4 in methanol. The dihedral angle between the benzene and pyridine rings is 84.46 (17)°. The piperidine ring adopts a screw-boat conformation. In the crystal, inversion dimers linked by two C—H⋯O bonds occur

    Efecto de la temperatura de molturación sobre la composición y calidad del aceite de oliva virgen

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    The objective of the current study was to assess the influence of a modified crushing process and kneading operation on the quality parameters, volatile compounds, and the fatty acid and sterol profiles of virgin olive oil from the Edremit yaglik variety. In the study, olive oil samples were produced in two different processes. The first one was produced without malaxation and the second one was produced with the malaxing process. During crushing, the effect of different temperatures was tested. The results demonstrate that different crushing temperatures generally did not affect the amount of free fatty acids, or peroxide value. Total phenol contents were positively affected by the additional malaxation process. Fatty acids and sterol composition were not significantly altered at different crushing temperatures or during the subsequent malaxation application. PCA enabled a clear classification of the oils obtained from different processing techniques.El objetivo del presente estudio fue evaluar la influencia de un proceso de molturación modificado y de la etapa de batido sobre los parámetros de calidad, los componentes volátiles, los ácidos grasos y el perfil de esteroles de aceites de oliva virgen de la variedad Edremit yaglik. En este estudio, las muestras de aceite de oliva se obtuvieron mediante dos procesos diferentes con y sin malaxación. Durante la trituración, se probó el efecto de diferentes temperaturas. Los resultados demostraron que las diferentes temperaturas de trituración, en general, no mostraron tener efecto sobre la cantidad de ácidos grasos libres o el índice de peróxido. El contenido total de fenoles se vio afectado positivamente por el empleo de malaxación. La composición de ácidos grasos y de esteroles no se vieron afectados significativamente por el aumento de la temperatura en la trituración ni durante el proceso de malaxación. PCA permitió una clasificación clara de los aceites obtenidos mediante las diferentes técnicas de procesamiento

    Isolated interrupted inferior vena cava with azygos continuation mimicking paraesophageal lymph node enlargement

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    We report a case of interrupted inferior vena cava with azygos continuation diagnosed as a isolated finding in a patient with lung carcinoma. Findings of the unopacified CT scan initially simulated a paraesophageal lymphadenopathy. The contrast - enhanced spiral CT scan showed a dilated azygos vein in the absence of definable inferior vena cava
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