Effect of Age, Gender and Vowel Type on Vowel Space Area in Sinhala Speakers

This study was conducted to document the effect of age, gender and vowel type on vowel space area in Sinhala language. Three groups of participants were employed. Group 1 included 20 children, Group 2 included 20 adults and Group 3 consisted of 20 elderly subjects. All the subjects spoke the dialect of central province of Sri Lanka. Words consisting of three Sinhala short vowels /a/, /i/ and /u/ in were recorded. Formant frequencies of vowels were extracted and vowel space area was constructed. The results showed that the formant frequencies were significantly higher for children compared with those of adults.Female subjects had significantly higher formant frequency values than male subjects. Effect of vowel types were also significant on the formant frequencies and vowel space area. Sinhala also follows universal criteria of resonance characteristics and vocal tract constriction.Keywords: vowel space area, formant frequencies, Sinhala, vowel articulatio

Effect of Age and Gender on Voice Onset Time: Data from Sinhalese

Objective: To documenting the voice onset time in voiced and unvoiced stop consonants in Sinhala and to investigating the effects of age and gender on voice onset time values in Sinhalese speakers. Methods: Three groups of participants were employed. Group 1 included 20 children, Group 2 included 20 adults and Group 3 consisted of 20 elderly subjects. All the subjects spoke the dialect of central province of Sri Lanka. Words consisting of three Sinhala short vowels /a/, /i/ and /u/ in were recorded. Voice onset time values from two voiced and voiceless stop consonants were extracted. Results: Voiced stop consonants had significantly longer voice onset time values compared to voiceless stop consonants. Significant effect of age as well as gender on voice onset time values were also observed. Conclusion: Supplementary investigations on the normative aspects of voice onset time among the Sinhala population would provide additional insights and validated tools for indexing the articulatory and acoustic characteristics of stop consonants in Sinhalese. Keywords: Voice Onset Time, Sinhalese, Elderly, Sinhala, Acoustic analysi

Experience with Dilute Chemical Decontamination in Indian Pressurized Heavy Water Reactors

AbstractDilute Chemical Decontamination (DCD) process has been used in several full system and components of nuclear coolant systems to effectively remove the radioactive contaminants that causes radiation field and consequent MANREM problem. The DCD process uses chemicals in very low concentrations (millimolar) and dissolves the oxide film along with the activity incorporated in the oxide film. In DCD process operated under the regenerative mode, the chemical formulation spent in the process of oxide dissolution is replenished by passing through cation exchange columns. Finally, after achieving sufficient decontamination of the system/component, the added decontamination chemicals along with the activities and metal ions released during the process are removed by mixed bed ion exchange columns and the system is restored to normal operating condition in a few days time. In PHWRs, the regenerative DCD process is applied for full primary coolant system decontamination. The chemicals are added directly to the heavy water coolant with the fuel in the core. In Indian PHWRs (MAPS#1&2, RAPS#1&2, NAPS#1&2 and KAPS#1), the process has been applied eleven times. A chemical formulation based on NTA, Citric acid and Ascorbic acid has been applied seven times with good results. Decontamination factors in the range 2-30 have been obtained in different components with good MANREM savings in the subsequent maintenance works.Efforts are on to modify the process to take care of the challenges posed by antimony isotopes. An inhibitor (Rodine-92B) based process was successfully tested in NAPS#2 for removing antimony isotopes (122Sb and 124Sb). Further refining of the antimony removal process is being worked out. Similarly, the process is being modified to effectively remove the hotspot causing stellite particles in the moderator system of PHWRs. A permanganate based process has been developed and tested in several adjustor rod drive mechanisms in KAPS and NAPS. The experience of applying/testing the DCD process in the Indian nuclear reactors is described in this paper

Moduli of Abelian varieties, Vinberg theta-groups, and free resolutions

We present a systematic approach to studying the geometric aspects of Vinberg theta-representations. The main idea is to use the Borel-Weil construction for representations of reductive groups as sections of homogeneous bundles on homogeneous spaces, and then to study degeneracy loci of these vector bundles. Our main technical tool is to use free resolutions as an "enhanced" version of degeneracy loci formulas. We illustrate our approach on several examples and show how they are connected to moduli spaces of Abelian varieties. To make the article accessible to both algebraists and geometers, we also include background material on free resolutions and representation theory.Comment: 41 pages, uses tabmac.sty, Dedicated to David Eisenbud on the occasion of his 65th birthday; v2: fixed some typos and added reference

Gauge Orbit Types for Theories with Classical Compact Gauge Group

We determine the orbit types of the action of the group of local gauge transformations on the space of connections in a principal bundle with structure group O(n), SO(n) or $Sp(n)$ over a closed, simply connected manifold of dimension 4. Complemented with earlier results on U(n) and SU(n) this completes the classification of the orbit types for all classical compact gauge groups over such space-time manifolds. On the way we derive the classification of principal bundles with structure group SO(n) over these manifolds and the Howe subgroups of SO(n).Comment: 57 page

2D-spectral estimation based on DCT and modified magnitude group delay

This paper proposes two new 2D-spectral estimation methods. The 2D-modified magnitude group delay (MMGD) is applied to 2D-discrete Fourier transform (2DDFT) for the first and to the analytic 2D-discrete Cosine transform for the second. The analytic 2D-DCT preserves the desirable properties of the DCT (like, improved frequency resolution, leakage and detectability) and is realized by a 2D-discrete cosine transform (2D-DCT) and its Hilbert transform. The 2D-MMGD is an extension from 1D to 2D, and it reduces the variance preserving the original frequency resolution of 2D-DFT or 2D-analytic DCT, depending upon to which is applied. The first and the second methods are referred to as DFT-MMGD and DCT-MMGD, respectively. The proposed methods are applied to 2D sinusoids and 2D AR process, associated with Gaussian white noise. The performance of the DCT-MMGD is found to be superior to that of DFT-MMGD in terms of variance, frequency resolution and detectability. The performance of DFT-MMGD and DCT-MMGD is better than that of 2D-LP method even when the signal to noise ratio is low

Anodising of aluminium in sulphamic acid electrolyte

Anodising of aluminium and its alloys in conventional anodising electrolytes such as sulphuric, oxalic, chromic and phosphoric acid to get the required physical properties for desired applications are well known. Anodising in organic acids was also investigated in the past. Hard anodising at ambient temperatute to get thick, Hard and wear resistant coating on alluminium alloys using sulphamic acid which is one such promising electrolyte. This electrolyte system has been selected due to lesser aggressive power and abiility to produce more compact oxide film on alluminium alloys. So a systematic investigation has been carried out and the physical properties of the oxide film produced under various operations conditions are measured. The effect of concentration, temperature, current density and addition agents on the quality of the oxide film are reported and the results are discussed