Velum Behavior in Professional Classic Operatic Singing

The velopharyngeal opening (VPO) is analyzed in 17 professional operatic singers, 3 high sopranos, 3 sopranos, 2 mezzo-sopranos, 3 tenors, 2 baritones, 2 bass-baritones, and 2 basses singing the vowels [a, i, u] at middle degree of vocal loudness at different pitches throughout their pitch range. Three methods were used for detection of a VPO. One was nasofiberscopy, which revealed VPO of various shapes in several singers. Another method was recording nasal and oral airflow by means of a divided flow mask. These measurements showed a nasal DC airflow at least at some pitches in a majority of the singers. A third method was a comparison of the level of the fundamental in the nasal and oral airflow signals; this level difference was less than 15 dB in cases where a nasal DC airflow was observed. Values less than 15 dB were observed in some cases, thus suggesting the presence of a VPO. The tokens produced by the singers were assessed by an expert panel with respect to nasal quality of the vowel timbre; no correlation was found between rated nasal quality and the presence of a VPO.     

Synthesis of 3,5-Dihydroxy-2-methylpyran-4-one (5-Hydroxymaltol)

We recently described the synthesis of the dihydropyranone 1 from aldohexoses and secondary amine salts¹: in addition to 1, Trace amounts of 5-hydroxyml to 1, 11, were formed. Compound 11 was isolated by preparative gas chromstography and identified by i.r., n.m.r., and mass spectrometric analysis.     

Single objective layout design of user interface components with multiple qualitative factors

The purpose of this paper is to present a model to design the layout of the user interface components that handles many numbers of qualitative factors. An alternate rating system is also proposed for the closeness relationship ratings between the various pairs of components evaluated by using GOMS (goals, operators, methods and selection rules) technique. The proposed model is applied to the design of the part of the user interface in order to obtain the best layout of the components. The results of the proposed model are compared with that of an existing model, which handles single qualitative factor applied to obtain the layouts of user interface components.     

Two Applications of a Generalization of an Asymptotic Fixed Point Theorem

We present a variant of an asymptotic version of the Abian-Brown Fixed Point Theorem, and applications to recursively defined sequences and Hammerstein integral equations.     

Temperature Driven Transformation of the Flexible Metal–Organic Framework DUT-8(Ni)

DUT-8(Ni) metal–organic framework (MOF) belongs to the family of flexible pillared layer materials. The desolvated framework can be obtained in the open pore form (op) or in the closed pore form (cp), depending on the crystal size regime. In the present work, we report on the behaviour of desolvated DUT-8(Ni) at elevated temperatures. For both, op and cp variants, heating causes a structural transition, leading to a new, crystalline compound, containing two interpenetrated networks. The state of the framework before transition (op vs. cp) influences the transition temperature: the small particles of the op phase transform at significantly lower temperature in comparison to the macroparticles of the cp phase, transforming close to the decomposition temperature. The new compound, confined closed pore phase (ccp), was characterized by powder X-ray diffraction and spectroscopic techniques, such as IR, EXAFS, and positron annihilation lifetime spectroscopy (PALS). Thermal effects of structural transitions were studied using differential scanning calorimetry (DSC), showing an overall exothermic effect of the process, involving bond breaking and reformation. Theoretical calculations reveal the energetics, driving the observed temperature induced phase transition.     

Die Existenz einer Gasphasenspezies BiSeO3I und das Verhalten bei Chemischen Transportreaktionen

The Existence of a Gaseous Species BiSeO₃I and the Behaviour at Chemical Vapour Transports The existence of gaseous species BiSeO₃I follows from chemical vapour transport experiments of BiOI_s with SeO_{2, g} as well as Bi₂SeO_{5, s} with BiI_{3, g} and SeO_{2, g} and Bi₂Se₃O_{9, s} witht BiI_{3, g}. The Enthalpy of formation and the Standardentropy were derived from the quantitative transport rates and the standard data of the solid state and gaseous phases.     

Bestimmung der Bildungsenthalpie von SmOCl durch Lösungskalorimetrie

Determination of the Enthalpy of Formation of SmOCl by Solution Calorimetry The enthalpy of formation of SmOCl (ΔH(SmOCl_f, 298) = —239.9 ± 0.5 kcal/mol) was determined from the heat of solution of SmOCl (ΔH_L(SmOCl_f298) = —31.24 ± 0.15 kcal/mol) on the base of the enthalpies of formation of Sm₂O₃ and SmCl₃ and their heats of solution in 4n HCl.