Porous ceramics based on diatomite: Mechanical properties and evolution of morphology after deformation

Journal of Electroceramics - The work is devoted to the study of the mechanical properties of porous ceramics based on diatomite, which has high porosity, adsorption capacity, weak thermal and...     

Diagnostic performance of edited 2HG MR spectroscopy of central glioma in the clinical environment

Magnetic Resonance Materials in Physics, Biology and Medicine - Oncometabolite D-2-hydroxyglutarate (2HG) is pooled in isocitrate dehydrogenase (IDH)-mutant glioma cells. Detecting 2HG by MR...     

Prediction of Power Consumption in a Mechanically Agitated Gassed Reactor in Viscous Batches

Volumetric mass transfer coefficient, power input, and gas holdup are key parameters in the design of mechanically agitated gas‐liquid contactors. Although the majority of industrial batches are of higher viscosity, reliable transport characteristics correlations for viscous batches are lacking in literature. These correlations are often based on the power input as the scale of energy dissipation. In order to develop reliable power input correlations, its measurements were carried out in a pilot‐plant vessel using multiple impellers of various types and diameters. Power input correlation shapes providing the best match with the comprehensive database are also expected to predict most precisely the impeller power in industrial‐scale vessels.     

Chemical Signals of Synthetic Disaccharide Derivatives Dominate Rhamnolipids at Controlling Multiple Bacterial Activities

Microbes secrete molecules that modify their environment. Here, we demonstrate a class of synthetic disaccharide derivatives (DSDs) that mimics and dominates the activity of naturally secreted rhamnolipids by Pseudomonas aeruginosa. The DSDs exhibit the dual function of activating and inhibiting the swarming motility through a concentration‐dependent activity reversal that is characteristic of signaling molecules. Whereas DSDs tethered with a saturated farnesyl group exhibit inhibition of both biofilm formation and swarming motility, with higher activities than rhamnolipids, a saturated farnesyl tethered with a sulfonate group only inhibits swarming motility but promote biofilm formation. These results identified important structural elements for controlling swarming motility, biofilm formation, and bacterial adhesion and suggest an effective chemical approach to control intertwined signaling processes that are important for biofilm formation and motilities.     

Mutual coupling between millimeter-wave dielectric-resonatorantennas

The mutual coupling between aperture coupled cylindrical dielectric-resonator antennas (DRAs) is analyzed using the finite-difference time domain method. The perfectly matched layer is used as absorbing boundary conditions. The voltage excitation source of microstrip structure is based on the Zhao's model, in which the source plane or the terminal plane can be moved very close to the discontinuity so that the computational domain can be reduced substantially. The numerical results are verified by measurements and reasonable agreement between theory and experiment is obtained. It is shown that this method is highly efficient for the analysis of DRAs     

A new inverted F antenna with a ring dielectric resonator

A new antenna combining the use of a ring dielectric resonator (DR) and an inverted F antenna (IFA) is proposed and investigated experimentally. In this application, the DR not only fills the role of a dielectric coating, but also serves the function of a radiator. The measurements of input impedance, return loss, and radiation pattern for both the IFA with the DR (IFA-DR) and the wire IFA (WIFA) are conducted at the S band. The measured data demonstrate that the IFA-DR operates in multiple resonance modes unlike a WIFA. Compared with the WIFA, the one proposed here incorporating a ring DR and an IFA is more attractive in having a smaller size and a larger impedance bandwidth     

Water based silicone elastomer controlled release tablet film coating V - A statistical approach

The silicone elastomer latex formulated with polyethylene glycol and colloidal silica produced a controlled release film coating on potassium chloride tablets. The release rate of potassium chloride was controlled by the total amount of polyethylene glycol and the weight fraction of polyethylene glycol 8000 and 1450 incorporated in the coating. A mathematical model was developed to quantitate the effect of coating components on the drug release rate using the statistical extreme vertices design. The predictive capability of this functional relationship was tested and validated experimentally.     

Detailed active site configuration of a new crystal form of methanol dehydrogenase from Methylophilus W3A1 at 1.9 A resolution

The three-dimensional structure of a new crystal form of methanol dehydrogenase from Methylophilus W3A1 has been obtained in the presence of substrate using data recorded at a synchrotron. The structure of this approximately 140 kDa heterotetramer, refined at 1. 9 A resolution, reveals the detailed configuration of its redox cofactor, pyrroloquinoline quinone (PQQ). C4, one of the oxygen-bearing atoms of this orthoquinone is in a planar configuration while C5, which bears the other quinone oxygen, is tetrahedral, suggesting that the PQQ is in the semiquinone redox state. The substrate binding site has been identified close to PQQ and to the side chain of Asp297, the putative active site base. The proximity of the hydroxyl of methanol to C5 of PQQ compared to the greater separation of the substrate methyl group from C5 supports the addition-elimination reaction mechanism involving a hemiketal intermediate.     

Dynamic characteristics of hydraulic brake devices with magnetorheological control

Consideration is given to the magnetorheological principle of control of an electrohydraulic brake device. The level of dissipation losses in the channel of the control unit, which determines the braking force in such systems, is regulated by a magnetic field adjusting a magnetosensitive pressure fluid to a prescribed effective viscosity. In an experiment, control of the main parameters characterizing the force and frequency characteristics of the device has been accomplished. It is found that the characteristic time of developing a braking force is 10⁻³ sec, and the speed of response of the system is mainly limited by the frequency characteristics of the inductor of the magnetic field of the magnetorheological throttling valve. Academic Scientific Complex “A. V. Luikov Heat and Mass Transfer Institute,” National Academy of Sciences of Belarus, Minsk, Belarus. Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 72, No. 5, pp. 874–880, September–October, 1999.