The PHENIX Experiment at RHIC

The physics emphases of the PHENIX collaboration and the design and current status of the PHENIX detector are discussed. The plan of the collaboration for making the most effective use of the available luminosity in the first years of RHIC operation is also presented.Comment: 5 pages, 1 figure. Further details of the PHENIX physics program available at http://www.rhic.bnl.gov/phenix

Laboratory investigation of asphaltene-induced formation damage

Abstract The purpose of this study is to evaluate the degree of formation damage caused by asphaltene deposition in the pore throats in case of oilfield operation. Many wells in the Samara region oilfields are operated under high reservoir drawdown, with downhole pressure lower than the bubble point. Such wells’ operating conditions lead to a change in oil composition (light components are extracted from oil while asphaltenes are precipitated and deposited) in the near wellbore, and the productivity of the wells declines due to asphaltene deposition. The study procedure presented in the paper included the following methods: high-pressure microscopy with grain size analysis (the visual method), the near infrared light scattering method and the gravimetric method to measure asphaltenes onset pressure in oil. Formation damage was measured by the filtration method. Asphaltene concentration in oil after filtration was measured by the photocolorimetric analysis. Microcomputed tomography of the core sample was provided to visualize formation damage. In addition, fluid flow in the pore space was simulated before and after asphaltene deposition using a dynamic simulator. In the paper, reservoir oil of one of the Russian oilfields was investigated. The main results of this paper are the following: asphaltene onset pressure in oil at the reservoir temperature (48 °C) was measured as equal to 6.8 MPa which is slightly higher than the bubble-point (6.5 MPa). Oil was flowed through the core sample of the field at three different specific backpressures (at constant flow rate) and formation damage was estimated. The studies have shown that decrease in permeability of the core is caused by asphaltene deposition in the pore space. In this case, a decrease in the amount of asphaltenes in oil emerging from the core sample is observed which was proved by the spectrophotometric analysis. Via microcomputed tomography, a 3D model of the rock matrix and the pore space of the initial and damaged core sample was constructed and a decrease in porosity after formation damage was estimated. Based on the obtained 3D model of the core, computer simulation of fluid flow (in a dynamic simulator) in the initial and damaged core was performed, and the flow parameters (velocity and streamlines) were calculated. The proposed methodology including a set of physical methods to study a core before and after formation damage combined with fluid flow simulation enables predicting potential complications under the field operation

Neuro-cognitive and biological effects of pine needle extract, Ropren on healthy elderly participants

Abstract not available

Application of Grazing-Incidence X-ray Methods to Study Terrace-Stepped SiC Surface for Graphene Growth

The synthesis of graphene by the graphitization of SiC surface has been driven by a need to develop a way to produce graphene in large quantities. With the increased use of thermal treatments of commercial SiC substrates, a comprehension of the surface restructuring due to the formation of a terrace-stepped nanorelief is becoming a pressing challenge. The aim of this paper is to evaluate the utility of X-ray reflectometry and grazing-incidence off-specular scattering for a non-destructive estimate of depth-graded and lateral inhomogeneities on SiC wafers annealed in a vacuum at a temperature of 1400–1500 °C. It is shown that the grazing-incidence X-ray method is a powerful tool for the assessment of statistical parameters, such as effective roughness height, average terrace period and dispersion. Moreover, these methods are advantageous to local probe techniques because a broad range of spatial frequencies allows for faster inspection of the whole surface area. We have found that power spectral density functions and in-depth density profiles manifest themselves differently between the probing directions along and across a terrace edge. Finally, the X-ray scattering data demonstrate quantitative agreement with the results of atomic force microscopy

Application of Molecular Modeling to Urokinase Inhibitors Development

Urokinase-type plasminogen activator (uPA) plays an important role in the regulation of diverse physiologic and pathologic processes. Experimental research has shown that elevated uPA expression is associated with cancer progression, metastasis, and shortened survival in patients, whereas suppression of proteolytic activity of uPA leads to evident decrease of metastasis. Therefore, uPA has been considered as a promising molecular target for development of anticancer drugs. The present study sets out to develop the new selective uPA inhibitors using computer-aided structural based drug design methods. Investigation involves the following stages: computer modeling of the protein active site, development and validation of computer molecular modeling methods: docking (SOL program), postprocessing (DISCORE program), direct generalized docking (FLM program), and the application of the quantum chemical calculations (MOPAC package), search of uPA inhibitors among molecules from databases of ready-made compounds to find new uPA inhibitors, and design of new chemical structures and their optimization and experimental examination. On the basis of known uPA inhibitors and modeling results, 18 new compounds have been designed, calculated using programs mentioned above, synthesized, and tested in vitro. Eight of them display inhibitory activity and two of them display activity about 10 μM

Rocking curve imaging of high quality sapphire crystals in backscattering geometry

We report on the characterization of high quality sapphire single crystals suitable for high-resolution X-ray optics at high energy. Investigations using rocking curve imaging reveal the crystals to be of uniformly good quality at the level of ∼10−4 in lattice parameter variations, δd/d. However, investigations using backscattering rocking curve imaging with a lattice spacing resolution of δd/d∼5×10−8 show very diverse quality maps for all crystals. Our results highlight nearly ideal areas with an edge length of 0.2–0.5 mm in most crystals, but a comparison of the back reflection peak positions shows that even neighboring ideal areas exhibit a relative difference in the lattice parameters on the order of δd/d=10–20×10−8; this is several times larger than the rocking curve width. Stress-strain analysis suggests that an extremely stringent limit on the strain at a level of ∼100 kPa in the growth process is required in order to produce crystals with large areas of the quality required for X-ray optics at high energy