Psychoacoustics of in-car switch buttons: From feelings to engineering parameters

The car interior is becoming quieter and other sounds are now exposed to user perception, such as the sound produced by interface buttons when actuated. So, the functional role of the button sound on interface operation and its aesthetic and emotional role on the user experience are now more important than before. However, little research and design effort has been paid to understand how to design buttons that produce a pleasant sound. Moreover, the button’s sound requirements received by interface manufacturers are ill-defined, insufficient or even inexistent, and consequently their conversion into specifications for manufacturing is problematic and leads to long and costly development processes. The purpose of this paper is to contribute to identify relevant acoustic parameters that explain the users sound preferences. Data on preference subjective judgments were collected and buttons acoustic signals were measured allowing the development of preference models based on partial least squares regression and neural networks methods. The former was successful in selecting the relevant parameters to describe the preference ratings of the buttons sound. The later, dealing with the non-linear nature of acoustic perception, was able to predict preferences based on the relevant parameters.     

Mean activity coefficient of electrolyte solutions

In this paper, we deal with the mean activity coefficient, gamma, of electrolyte solutions. The case gamma < or = 1 is investigated. As is generally recognized, the most accepted models (specific ion interaction/Pitzer theory) have the disadvantage of the dependence on semiempirical parameters. These are not directly accessible from experimental measurements, but can only be estimated by means of best-fitting numerical techniques from experimental data. In the general context of research devoted to the achievement of some reduction of complexity, we propose a model of electrolyte solution that allows us to calculate gamma without using fitting parameters where the (upper) concentration exists at which the electrolyte solution exhibits gamma = 1 (molality scale). In the remaining cases, we show that a unique parameter is required, that is, the concentration that should ideally give gamma = 1 for the electrolyte. Compared to other models that do not require adjustable parameters, the present one is generally applicable over a wider range of concentrations; moreover, it does not impose any restriction on the ion-size variations. Our model follows a pseudolattice approach, starting from the primitive idea of a disordered lattice of solute ions within a continuous solvent at extremely dilute solutions and coming to a disordered lattice of local arrangements of both solute ions and solvent dipoles at higher concentrations. Compared to other theories based on lattice models, this work stresses the role of statistical deviations from any time-averaged (lattice) configuration. All formulas in this paper are applied for 1:1, 2:2, 1:2, and 2:1 aqueous electrolytes at 25 degrees C.     

Transition metal bisdithiolene complexes based on extended ligands with fused tetrathiafulvalene and thiophene moieties: new single-component molecular metals

The gold and nickel bisdithiolene complexes based on new highly extended ligands incorporating fused tetrathiafulvalene and thiophene moieties (alpha-tdt=thiophenetetrathiafulvalenedithiolate and dtdt=dihydro- thiophenetetrathiafulvalenedithiolate), were prepared and characterised by using cyclic voltammetry, single crystal X-ray diffraction, EPR, magnetic susceptibility and electrical transport measurements. These complexes, initially obtained under anaerobic conditions as diamagnetic gold monoanic [nBu(4)N][Au(alpha-tdt)(2)] (4), [nBu(4)N][Au(dtdt)(2)] (3) and nickel dianionic species [(nBu(4)N)(2)][Ni(alpha-tdt)(2)] (8), [(nBu(4)N)(2)][Ni(dtdt)(2)] (7), can be easily oxidised to the stable neutral state just by air or iodine exposure. The monoanionic complexes crystallise in at least two polymorphs, all of which have good cation and anion segregation in alternated layers, the anion layers making a dense 2D network of short SS contacts. All of the neutral complexes, obtained as microcrystalline or quasi amorphous fine powder, present relatively large magnetic susceptibilities that correspond to effective magnetic moments in the range 1-3 mu(B) indicative of high spin states and very high electrical conductivity that in case of the Ni compound can reach sigma(RT) approximately 250 S cm(-1) with a clear metallic behaviour. These compounds are new examples of the still rare single-component molecular metals.     

Polymers for microlithographic applications: new directions and challenges

Advances in the fabrication technologies associated with electronic devices have placed increasing demands on microlithography, the technology used to generate today's integrated circuits. Within the next few years, a new form of lithography will be required that routinely produces features of less than 0.1 μm. As the exposing wavelength of light decreases to facilitate higher resolution imaging, the opacity of traditional materials precludes their use; and major research efforts to develop alternate materials are underway. As a current example, lithography tools utilizing 193 nm light are now being introduced into the manufacturing environment. Through understanding of materials structure and its relationship to device process requirements and performance, a new class of cyclo‐olefin based polymers was designed for these applications. In particular, alicyclic monomers such as norbornene are readily copolymerized with maleic anhydride and substituted acrylates to afford a wide range of alternative matrices that exhibit transparency at the exposing wavelength and aqueous base solubility. Materials properties must be carefully tailored to maximize lithographic performance with minimal sacrifice of other performance attributes. Further reduction in exposing wavelength to 157 nm introduces new challenges in polymer materials design. Efforts to address those challenges will be discussed.     

The nicholas approach to natural product hybrids

The intermolecular Nicholas reaction of terpene-based scaffolds is an excellent access to natural product hybrid compounds. These intermolecular reactions have a low selectivity and are scarcely efficient for non-conjugated cations, but they are highly efficient to produce new terpene structures through an intramolecular reaction pathway. The use of cations derived from natural product derived [Co(2)(CO)(6)]-enyne complexes is, in contrast, a highly efficient regio- and stereoselective procedure to prepare very complex structures, incorporating diverse densely functionalized or labile moieties. Thus, beta-pinene-diterpene-alkaloid or homohybrids can be accessed in totally stereo-, regio- and siteselective fashion. This approach efficiently discriminates between different propargylic positions by selecting the nature of the alcohol, being the enyne-derived cations the most reactive. The chimera 38 with a steroid-terpene-indole skeleton was prepared in this way.     

Structural and hyperfine properties of Mn and Co-incorporated akaganeites

The structural and hyperfine properties of pure and substituted akaganeites prepared in the presence of Mn, Co and urea are presented and discussed. In all samples, the chloride content increased with the increase in the urea concentration of the parent solution, and a small Mn-for-Fe or Co-for-Fe substitution occurred. In pure akaganeites, the increase of urea concentration provoked an enlargement of the unit cell volume and a decrease of the crystallinity of the synthesised oxides. The incorporation of Mn and Co provoked changes in cell parameters and an increase in the crystallinity of the samples. The hyperfine parameters for both iron sites of the akaganeites remained practically unchanged, and the spectral areas of the iron sites located close to the chlorides decreased for the doped samples. The recoilless f-factor increased for the substituted akaganeites, indicating an increase in the strength of the atomic bonding of the iron ions.     

Grafting onto microfibrils of native cellulose

Attempts to modify the surface of oxidized cellulose microfibrils were made using amine terminated molecules. First, native cellulose was oxidized with catalytic amounts of 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO), sodium hypochlorite and sodium bromide in water. The primary alcohol moieties were selectively oxidized into carboxyl groups. Then, the oxidized cellulose was coupled with amines derivatives by a peptidic reaction by using carbodiimide and hydroxysuccimide as catalyst and amidation agent. The obtained coupled cellulose showed low polarity, with stability in non-polar solvents. The products were characterized by FTIR, ¹³C NMR, rheology and conductometric titration as well as transmission electron microscopy. Their hydrophobic character was evaluated by observing their behavior in polar and non-polar solvents.     

About Earthquake Forecasting by Markov Renewal Processes

We propose and validate a new method for the evaluation of seismic hazard. In particular, our aim is to model large earthquakes consistently with the underlying geophysics. Therefore we propose a non-Poisson model, which takes into account occurrence history, improved with some physical constraints. Among the prevalent non-Poisson models, we chose the Markov renewal process, which is expected to be sufficient to capture the main characteristics, maintaining simplicity in analysis. However, due to the introduction of some physical constraint, our process differs significantly from others already presented in literature. A mixture of exponential + Weibull distributions is proposed for the waiting times and their parameters are estimated following the likelihood method. We validated our model, using data of earthquakes of high severity occurred in Turkey during the 20th century. Our results exhibit a good accordance with the real events.