The identification of tyre induced vehicle interior noise

Sound transmission into a vehicle is classified as either airborne or structure borne sound. From the point view of noise control, the reduction of noise transferred by different paths requires different solutions. Coherence function analysis is often used to identify transmission paths. However it can be difficult to separate the airborne from structure borne components. The principle of acoustic reciprocity offers a convenient method for overcoming this difficulty. The principal states that the transfer function between an acoustic volume velocity source and an acoustic receiver is independent of a reversal of the position of source and receiver. The work done on this study involves exciting a stationary tyre and measuring the surface velocity of the tyre at a number of discrete points. The acoustic transfer functions between each point on the tyre and a receiver point are measured reciprocally. Two sets of measurements are then combined to yield a measure of the sound pressure due to a point force on the tyre via the acoustic transmission path only. This technique also provides information on the relative contributions of various regions of the tyre wall to the resultant noise. Also the sound radiation characteristics, the horn effect, and resonance at the wheel housing are identified through the reciprocal measurement.     

Fine competition and control among argentophilic,electrostatic, and π···π interactions in a molecular chair structure

The reaction of AgX (X⁻ = NO₃ ⁻, ClO₄ ⁻, or CF₃SO₃ ⁻) with 1,3-bis(3-pyridyl)tetramethyldisiloxane (L) at room temperature affords 20-membered metallacyclodimers, [Ag(L)]₂(X)₂. For the macrocyclodimer, fine competition among argentophilic, electrostatic, and π···π interaction exists. The macrocyclodimer is a unique molecular chair that tunes a transannular argentophilic interaction via the bite size of the counteranions. In order to reversibly control the argentophilic interaction, anion exchange has been accomplished. The anion exchangeability depends on the water solubility rather than the electrostatic interaction between silver(I) and anions.     

Directing Polymorphism in the Helical Nanofilament Phase

Herein, it is reported that the polymorphism in the helical nanofilament (HNF, B₄) liquid-crystalline phase depends on the fabrication methods, that is, UV-driven formation and template-assisted self-assembly in the nanoconfined geometry. As a result, uniaxially oriented HNFs with different helical structures were obtained, in which generation of the twisted-ribbon and cylindrical-ribbon polymorphs showed that even the molecular lattice has a different orientation. The detailed structures were directly observed by SEM and grazing-incidence X-ray diffraction with synchrotron radiation. The resultant polymorphs could be used in chiro-optical applications due to the capability for fine control of the helical structures.     

The impact of investment lags on investment decision

This paper suggests a valuation framework for an investment project through the concept of real options. Generally, in real asset world, decision time and its payment time are not identical. This so-called investment lag problem should be considered when valuing real assets. When investment lags exist, firms’ accommodation capacities play important roles. In this paper, the real effect of investment lag on investment value is tested upon various conditions. We show the valuation process of real assets under the risk-neutral world. The closed-form formula is also provided for valuing real assets, including R&D project.     

Numerical simulation of power law and yield stress fluid flows in double concentric cylinder with slotted rotor and vane geometries

In our previous report, we showed that a rheometer equipped with a double concentric cylinder geometry with slotted rotor could effectively reduce wall slip effects and thus it could be used as an alternative to a rheometer with a vane geometry in yield stress measurements. Here, we use three-dimensional CFD simulation to compare these two geometries for rheological measurements of power law and yield stress fluids. Our results indicate that the double concentric cylinder rheometer with slotted rotor (DCCR/SR) is able to accurately measure rheological properties of a wider spectrum of test fluids than a vane rheometer because of significant reduction of the end and secondary flow effects.     

Synthesis of novel pyridazine nucleosides

This paper presents the synthesis of novel pyridazine nucleosides containing the dicyanomethylene group and pyrrolo[2,3‐c]pyridazine nucleoside.     

Deposition of osmium and ruthenium thin films from organometallic cluster precursors

Single‐source organometallic precursors based on a number of homometallic clusters as well as heterometallic cluster RuOs₃(CO)₁₃(µ‐H)₂ have been used for the chemical vapor deposition of osmium films and osmium–ruthenium alloy films, respectively. Copyright © 2009 John Wiley & Sons, Ltd.