Sail aerodynamics: Understanding pressure distributions on upwind sails

The pressure distributions on upwind sails is discussed and related to the flow field around the headsail and the mast/mainsail. Pressures measured on several horizontal sections of model-scale and full-scale sails are used to provide examples. On the leeward side of the sails, leading edge separation and turbulent reattachment occurs, sometimes followed by trailing edge separation. On the windward side, leading edge separation occurs on the mast/mainsail and, at low angles of attack, it can also occur on the headsail. Differences were found between the leading edge bubbles on the two sails. Pressure trends for different angles of attack are presented, and these can be explained in terms of standard aerodynamic theory, particularly in terms of short and long leading edge separation bubble types. It was found that the pressure distributions measured on mainsails at full- and model-scale showed good agreement on both the windward and leeward sides.     

In search of the quantum oneness

Final State Interactions. By John Gillespie. (Holden-Day Inc., 728 Montgomery St., San Francisco, 1965.) [Pp. viii + 104.] $6.95.

Puzzles and Paradoxes. By T. H. O'Beirne. (Oxford University Press, 1965.) [Pp. xiv + 238.] 30s.

Discovering Physics. By Philip E. Heafford. (Longmans, 1965.) [Pp. x + 262.] 15s.

The Reactivity of Solids. International Symposium, Munich 1964. (Butterworth, 1965 .) [Pp. v + 387452.] 20s.

Concepts in Physics. By Reuben Benumof. (Prentice Hall, 1965.) [Pp. 562.]

Elements of Physics. (4th Edition.) By George Shortley and Dudley Williams. (Prentice-Hall, 1965.) [Pp. xiii + 924.] 84s.

Physics. By K. R. Atkins. (John Wiley &; Sons Ltd., 1965.) [Pp. 754.1 72s.

Introduction to Mathematics with Applications. By Herbert Barkhan and Carl Konove. (D. Van Nostrand, 1965.) [pp. xiii + 365.] 62s.

Quasi-Stellar Sources and Gravitational Collapse. Edited by Ivor Robinson, Alfred Schild and E. L. Schucking. (University of Chicago Press.) [Pp. 475.] 72s.

Solid State Physics. Vol. 16. Edited by F. Seitz and D. Turnbull. (Academic Press, 1964.) [Pp. xvit-446.] 124s.

Angular Correlation Methods in Gamma-Ray Spectroscopy. By A. J. Ferguson. (Amster- dam: North Holland Publishing Co., P.O. Box 103, 1965.) [Pp. xi+214.] 50s.

Classical Dynamics. By Jerry B. Marion. (Academic Press Inc., 111 Fifth Avenue, New York, 1965.) [Pp. xv + 576.] 92s.

Scientijic Research in British Universities and Colleges 1964-65. Vol. I. Physical Sciences, pp. xix + 368, price 37s. 6d. Vol. 11. Life Sciences, pp. xviii + 404, price 40s.

Theory of Superconductiwity. By G. Richayzen. (Wiley, 1965.) [Pp. xvi+483.] 170s.

Auroral Phenomena. Edited by MARTIN WALT. (O.U.P., 1965.) [Pp. 170.1 40s.

Physics of Thin Films. Vol. 11. Edited by Georg Haw and Rudolf Thun. (Academic Press, 1964.) [Pp. xii + 441.] 120s.     

Energy Science,Principles, Technologies and Impacts: Second Edition,by John Andrews and Nick Jelley

It is now possible to obtain informative nuclear magnetic resonance (NMR) spectra from living tissue such as muscle. A discussion is given of the various ways in which NMR can be applied to biological material, and particular emphasis is placed on some recent phosphorus NMR studies of muscle. These studies can provide detailed information about the chemical reactions that are associated with muscular contraction. Mention is made of some of the biochemical and medical applications of NMR that may become feasible in the next few years.     

Characterization of poly(ethylene oxide) modified with different phenyl hepta isobutyl polyhedral oligomeric silsesquioxanes

Journal of Thermal Analysis and Calorimetry - Poly(ethylene oxide)/polyhedral oligomeric silsesquioxanes (PEO/POSSs) composites were prepared by the melting method. The investigation of their...     

Validation of a liquid chromatography coupled with tandem mass spectrometry method for the determination of drugs in wastewater using a three‐phase solvent system

Pharmaceuticals constitute one of the most important emerging classes of environmental pollutants. A three‐phase solvent system of water, water containing 0.1% of formic acid and acetonitrile was successfully used to separate, by liquid chromatography with mass spectrometry (LC‐MS), polarity‐matched pharmaceuticals, that is, carbamazepine, clarithromycin, and erythromycin, as well as amoxicillin and metformin. Despite of polarity similarities, these pharmaceuticals were completely resolved in the analytical run time of 15 min. The optimized three‐phase solvent system based‐method was validated for the simultaneous analysis of six matched‐polarity pharmaceuticals in wastewater samples. Good linearity (coefficient of determination more than 0.993) and precision (relative standard deviation less than 15.66%) were achieved. Recovery of analytes from the wastewater was between 0.70 and 1.18. Limits of detections ranged from 0.0001 to 0.5114 µg/L. No significant matrix effect, evaluated by post extraction addition, was observed in the electrospray ionization (ESI) source. Then, this methodology has been successfully applied to environmental study of pharmaceutical residues occurring in influent and effluent wastewater samples, from the main wastewater treatment plant in Potenza (Basilicata, Southern Italy).     

Characterization of artificial spherical particles for DEM validation studies

This paper describes a study in which advanced particle-scale characterization was carried out on spherical particles that can be used in experimental tests to validate discrete element method (DEM) simulations. Two types of particle, alkaline and borosilicate glass beads, made from two different materials, were considered. The particle shape, stiffness, contact friction properties and surface roughness were measured. The influences of hardness and roughness on the mechanical response of the particles were carefully considered. Compared to the alkaline beads, the borosilicate beads were more spherical and more uniform in size, and they exhibited mechanical characteristics closer to natural quartz sand. While only two material types were studied, the work has the broader implication as a methodology for selecting particles suitable for use in DEM studies and the key parameters that should be considered in the selection process are highlighted.     

Almost‐anywhere theories: Reductionism and universality of emergence

Here, we aim to show that reductionism and emergence play a complementary role in understanding natural processes and in the dynamics of science explanation. In particular, we will show that the renormalization group—one of the most refined tools of Theoretical Physics—allows to understand the importance of emergent processes' role in Nature identifying them as universal organization processes, that is, they are scale independent. We can use the syntaxes of Quantum Field Theory and the processes of Spontaneous Symmetry Breaking as a trans‐disciplinary theoretical scenario for many other forms of complexity, especially the biological and cognitive ones. © 2010 Wiley Periodicals, Inc. Complexity, 2010     

Optimizing the photocatalytic properties of hydrothermal TiO2 by the control of phase composition and particle morphology. a systematic approach

The possibility of controlling the photocatalytic activity of TiO2 nanoparticles by tailoring their crystalline structure and morphology is a current topic of great interest. In this study, a broad variety of well-faceted particles with different phase compositions, sizes, and shapes have been obtained from concentrated TiOCl2 solutions by systematically changing temperature, pH, and duration of the hydrothermal treatment. The guide to select the suitable experimental conditions was provided by thermodynamic modeling based on available thermochemical data. By combining the results of TEM, HRTEM, XRD, density, and specific surface area measurements, a complete structural and morphological characterization of the particles was performed. Correlation between the photocatalytic activity in the UV photodegradation of phenol solutions and the particle size was established. Prismatic rutile particles with length/width ratio around 5 and breadth of 60-100 nm showed the highest activity. The surface chemistry of the particles was also investigated. Treatments that decrease the surface acidity, such as washing the powders with ammonia solution and/or calcining at 400 degrees C, have detrimental effect on photocatalytic activity. The overall results suggest correlation between particle morphology and photocatalytic activity and indicate that both electron-hole recombination and adsorption at the surface can be rate-controlling processes. The systematic approach presented in this study demonstrates that a substantial improvement of the photocatalytic activity of TiO2 can be achieved by a careful design of the particle morphology and the control of the surface chemistry.     

Stereochemical control mechanisms in propylene polymerization mediated by C1-symmetric CGC titanium catalyst centers

This work analyzes stereochemical aspects of olefin polymerization processes mediated by the C1-symmetric constrained geometry catalyst H2Si(ind)(tBuN)TiCH3+ (ind = indenyl), including the role of the cocatalyst/counteranion. The energetics of catalyst activation are first analyzed and shown to compare favorably with experiment. The energetics of heterolytic ion pair separation are next scrutinized, and the effects of solvation environment are assessed. Computed thermodynamic profiles for ethylene insertion at H2Si(ind)(tBuN)TiCH3+ indicate that the kinetics of insertion processes at the H2Si(ind)(tBuN)TiR+ cation can be analyzed in terms of SCF potential energies. We next compare the energetic profile for ethylene insertion at the naked H2Si(ind)(tBuN)TiCH3+ cation with that at the related H2Si(ind)(tBuN)TiCH3+H3CB(C6F5)3- ion pair to understand counterion effects. It is seen that the counterion, although affecting overall catalytic activity, does not significantly influence enchainment stereochemistry or polymer microtacticity. Next, the second ethylene insertion at H2Si(ind)(tBuN)Ti(nC3H7)+H3CB(C6F5)3- is analyzed to evaluate counteranion influence on the propagation barrier. It is found that the ethylene uptake transition state is energetically comparable to the first insertion transition state and that solvation has negligible effects on the energetic profile. These findings justify analysis of the propylene insertion process within the less computationally demanding "naked cation" model. Thus, monomer enchainment at H2Si(ind)(tBuN)TiR+ is analyzed for H2Si(ind)(tBuN)TiCH3+ + propylene (first insertion) and for H2Si(ind)(tBuN)Ti(iC4H6)+ + propylene (second insertion). Data describing the first insertion highlight the sterically dominated regioselection properties of the system with activation energies indicating that olefin insertion regiochemistry is predominantly 1,2 (primary), while the second insertion similarly reflects the catalyst stereoinduction properties, with steric effects introduced by the growing chain (mimicked by an isobutyl group) preferentially favoring insertion pathways that afford isotactic enrichment, in agreement with experiment.     

Self-assembly of nanosize coordination cages on si(100) surfaces

Bottom-up fabrication of 3D organic nanostructures on Si(100) surfaces has been achieved by a two-step procedure. Tetradentate cavitand 1 was grafted on the Si surface together with 1-octene (Oct) as a spatial spectator by photochemical hydrosilylation. Ligand exchange between grafted cavitand 1 and self-assembled homocage 2, derived from cavitand 5 bearing a fluorescence marker, led to the formation of coordination cages on Si(100). Formation, quantification, and distribution of the nanoscale molecular containers on a silicon surface was assessed by using three complementary analytical techniques (AFM, XPS, and fluorescence) and validated by control experiments on cavitand-free silicon surfaces. Interestingly, the fluorescence of pyrene at approximately 4 nm above the Si(100) surface can be clearly observed.