511 research outputs found

    ACOUSTIC BUILDING UNITS FOR FORMANT SYNTHESIS TEXT-TO-SPEECH CONVERTER SYSTEM FOR MODERN STANDARD ARABIC

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    In this paper an inventory of acoustic building units (ABUs) used for the synthesis of Arabic speech is presented. The ABUs are generated for the free programmable PCF-8200 formant synthesizer chip which has been used in the development of the real time text-to-speech multilingual system, the MULTIVOX. To utilize these ABUs for the synthesis of Arabic speech a set of 36 Arabic sounds and all their possible combinations are defined. The inventory of 255 ABUs is designed that each sound combination can be built up by using some of those ABUs. A grapheme-to-phone-code converter is designed so to convert the written input text into its equivalent phone-codes. Furthermore, it contains solutions for the difficult phonetic problems in the Arabic input text

    DATA-BASE RULE-SYSTEM FOR THE MULTIVOX TEXT-TO-SPEECH CONVERTER APPLICATION FOR ARABIC LANGUAGE

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    The MULTIVOX-Multilingual text-to-speech converter system is adapted to Modern Standard Arabic. In this system, Arabic speech is generated from the concatenation of a set of acoustic building units (ABUs). A 3-dimensional data-base rule-system for the synthesis of unlimited vocabulary Arabic text is organized to concatenate the appropri- ate ABUs for all possible phone-code pairs that may exist in the input text. The main functions of the MULTIVOX are explained. Illustrative examples are given to show the conversion of Arabic graphemes into phone-codes and the use of the data-base rule-system in the concatenation of the ABUs. Hearing tests have been carried out to test the quality of the synthesized speech

    Natural solution to antibiotic resistance: bacteriophages ā€˜The Living Drugsā€™

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    Antibiotics have been a panacea in animal husbandry as well as in human therapy for decades. The huge amount of antibiotics used to induce the growth and protect the health of farm animals has lead to the evolution of bacteria that are resistant to the drugā€™s effects. Today, many researchers are working with bacteriophages (phages) as an alternative to antibiotics in the control of pathogens for human therapy as well as prevention, biocontrol, and therapy in animal agriculture. Phage therapy and biocontrol have yet to fulfill their promise or potential, largely due to several key obstacles to their performance. Several suggestions are shared in order to point a direction for overcoming common obstacles in applied phage technology. The key to successful use of phages in modern scientific, farm, food processing and clinical applications is to understand the common obstacles as well as best practices and to develop answers that work in harmony with nature

    Kinetic Study of the Hydrolysis of synthesized Ibuprofen Ester and its Biological Activity

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    It is known that the oral administration of ibuprofen caused an irritation of stomach as a side effect due to its carboxylic moiety. Ibuprofen ester was synthesized by linking the carboxylic moiety of ibuprofen and the hydroxylic group of paracetamol to reduce its side effect. Study the kinetic hydrolysis of prepared ester was examined at different values of physiological pH (1.0, 5.8, 6.4 and 7.4) at 37 Ā± 0.1 of 1 hour period. Measurements of absorbance were carried out by UV-Visible spectrophotometer to follow the stability of ester, it showed Pseudo first order hydrolysis. The pH- apparent rate profiles of ester was exhibited a good stability at pH 1.0 and pH 5.8. Pharmacological activity in vivo of prepared ester was evaluated in relation to analgesic and anti-inflammatory activity using the acetic acid method and the hind paw oedema inhibition, respectively. Acetyl salicylic acid (aspirin) was used as a reference drug for the above tests. The synthesized ester showed higher analgesic and anti-inflammatory action than aspirin

    Preparation and Study of Properties of CdO: Al Thin Films Prepared by Chemical Spraying

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    The studies that are related to transparent conducting oxides and the consistent motivation to improve their different characteristics have been increasingly conducted. In this work, pristine and Aluminium doped cadmium oxide, CdO: Al thin films, were synthesized by a deposition over a substrate made from glass employing spray pyrolysis technique for several Al fractions (0, 3.0, and 6.0) v/v %. The effect of Al dopant on the microstructure, morphological, optical and electrical characterisation of CdO thin films were investigated elaborately. Pure CdO and (Al: CdO) exhibited face centred cubic structure with strong peak of 200 that reflected a preferential growth. The roughness of films was increased for the samples doped with Al from (38.54 to 149.2) nm according to the increment in Al concentration. The optical analysis confirmed that the value of band gap manifested a decrement (2.5 - 2.0) eV associated with the increment in doping by Al. The measurements of Hall Effect elucidated that the CdO and Al: CdO films classified as n-type semiconductors. The range of electrical conductivity of the Al: CdO films evinced a variation from (42.4 to 35.3) Ī©-1.cm- 1. The results concluded from some graphs emphasized that the activation energy is equal to zero, and the Al doped CdO films became a degenerated semiconductor

    Enhanced thermoelectric properties of the Zintl phase BaGa_2Sb_2 via doping with Na or K

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    Na- or K-doped samples of Ba_(1āˆ’x)(Na, K)xGa_2Sb_2 were prepared by ball-milling followed by hot-pressing. The topological analysis of the electron density of BaGa_2Sb_2 implies a polar covalent nature of the Sbā€“Ga bonds in which the Sb atoms receive the electrons transferred from Ba rather than the Ga atoms. Successful doping of BaGa_2Sb_2 with Na or K was confirmed with combined microprobe and X-ray diffraction analysis. Alkali metal doping of BaGa_2Sb_2 increased the p-type charge carrier concentration to almost the predicted optimum values (āˆ¼10^(20) h^+ cm^(āˆ’3)) needed to achieve high thermoelectric performance. With increasing alkali metal concentration, electronic transport was shifted from non-degenerate semiconducting behaviour observed for BaGa_2Sb_2 to degenerate one for Na- or K-doped compounds. Overall, the thermoelectric figure of merit, zT, values reached up to āˆ¼0.65 at 750 K, considerably higher than the undoped sample (zT āˆ¼ 0.1 at 600 K), and a slight improvement relative to previously reported Zn-doped samples (āˆ¼0.6 at 800 K)

    Thermoelectric properties of the Yb_9Mn_(4.2-x)Zn_xSb_9 solid solutions

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    Yb_9Mn_(4.2)Sb_9 has been shown to have extremely low thermal conductivity and a high thermoelectric figure of merit attributed to its complex crystal structure and disordered interstitial sites. Motivated by previous work which shows that isoelectronic substitution of Mn by Zn leads to higher mobility by reducing spin disorder scattering, this study investigates the thermoelectric properties of the solid solution, Yb_9Mn_(4.2āˆ’x)Zn_xSb_9 (x = 0, 1, 2, 3 and 4.2). Measurements of the Hall mobility at high temperatures (up to 1000 K) show that the mobility can be increased by more than a factor of 3 by substituting Zn into Mn sites. This increase is explained by the reduction of the valence band effective mass with increasing Zn, leading to a slightly improved thermoelectric quality factor relative to Yb_9Mn_(4.2)Sb_9. However, increasing the Zn-content also increases the p-type carrier concentration, leading to metallic behavior with low Seebeck coefficients and high electrical conductivity. Varying the filling of the interstitial site in Yb_9Zn_(4+y)Sb_9 (y = 0.2, 0.3, 0.4 and 0.5) was attempted, but the carrier concentration (~10^(21) cm^(āˆ’3) at 300 K) and Seebeck coefficients remained constant, suggesting that the phase width of Yb_9Zn_(4+y)Sb_9 is quite narrow

    Method for the location of primary wear scars from retrieved metal on metal hip replacements

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    Retrieved metal-on-metal acetabular cups are valuable resources in investigating the wear behaviour of failed hip implants, but adequate methods to do so are lacking. To further contribute to addressing this issue, we developed a method to detect the in vivo location of the primary wear scar of an explanted cup

    Effect of the Metallization on the Resonances of THz Fishnet Metamaterials

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    In this numerical study, the influence of the choice of metal (and hence of the conductivity) used for the fabrication of THz fishnet metamaterials is investigated. We explore an exemplary structure for which surface-plasmon-polaritons offer ā€“ assuming sufficiently good conductivity ā€“ pronounced extraordinary transmission and strong multiple magnetic resonances with negative permeability. We analyze the dependence of these signatures on the type of metallization. Studying five different metals, we find that the metallization is important for achieving the multiple resonances. A reduction of the conductivity can lead to a dramatic weakening and even a near-disappearance of magnetic resonances if they lose their diamagnetic character

    STUDY OF THE FIRE PERFORMANCE OF HYBRID STEEL-TIMBER CONNECTIONS WITH FULL-SCALE TESTS AND FINITE ELEMENT MODELLING

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    Connection design is critical in timber buildings since the connections tend to have lower strength than the structural members themselves and they tend to fail in a brittle manner. The effect of connection geometry on the fire performance of a hybrid steel-timber shear connection is investigated by full-scale testing. These tests were conducted by exposing the test specimens to the standard time-temperature curve defined by CAN/ULC-S101 (CAN/ULC-S101, 2007). Test results showed that the fire resistance of these connections depends on the load ratio, the type of connection and the relative exposure of the steel plate to fire. Finite element models of the connections under fire were constructed using ABAQUS/CAE and these were validated using the test results. These numerical model results correlate well with test results with Ā±8.32% variation
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