101 research outputs found

    Acoustic Analysis of Nigerian English Vowels Based on Accents

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    Accent has been widely acclaimed to be a major source of automatic speech recognition (ASR) performance degradation. Most ASR applications were developed with native English speaker speech samples not minding the fact that the majority of its potential users speaks English as a second language with a marked accent. Nigeria like most nations colonized by Britain, speaks English as official language despite being a multi-ethnic nation. This work explores the acoustic features of energy, fundamental frequency and the first three formats of the three major ethnic groups of Nigerian based on features extracted from five pure vowels of English obtained from subjects who are Nigerians. This research aimed at determining the differences or otherwise between the pronunciations of the three major ethnic nationalities in Nigeria to aid the development of ASR that is robust to NE accent. The results show that there exist significant differences between the mean values of the pure English vowels based on the pronunciation of the three major ethnics: Hausa, Ibo, and Yoruba. The differences can be explored to enhance the performance of ASR in recognition of NE

    Construction and Testing of a Treatment System for Raw Water

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    Water is a wonder of Nature. One among the major problems confronting the world today is access to clean and safe water. The objective of the study was to assemble an affordable water treatment unit for domestic use. This study was carried out in Auchi, which is located between latitude 70 10’ and 70 20’ North of the equator and longitude 60 16’ and 60 36’ east of the Greenwich Meridian with an altitude of 207m. The components of the treatment system are raw water tank, coagulation tank, sedimentation tank, filtration chamber, micro filters, ultraviolent light and treated water storage tank. Sample of the raw water collected from River Orhle in Auchi was kept at a constant temperature in a refrigerator. The raw and  treated water sample was collected in a four litres jerican for laboratory analysis to test for Turbidity, pH, Appearance, Taste, Colour, Electrical conductivity, total dissolved solid (TDS), Nitrates, iron content, total hardness etc. The results met the desired specifications and standards set by WHO and NAFDAC for potable water usage. Keywords: Potable water, raw water, water treatment, slow sand filter, ultraviolent light, water qualit

    Effect of Piper guineensees on physicochemical and organoleptic properties of watermelon (Citrulus lanatus) juice stored in refrigerator and ambient

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    Extracted juice from watermelon containing 0.01gPiper guineensesstored in refrigerator (6±2 oC) and on the shelf (28±1oC) usingpolyethylene bottles was evaluated for physicochemical and organoleptic changes. pH, total soluble sugars, titratable acidity and organolepticevaluation of the juice was carried out till deterioration sets in. Results showed that the sample stored in therefrigerator kept for 7 days while the sample on the shelf lasted for 3 days. pH value decreased from 5.40 to 4.80 and 5.70 for the samplestored in the refrigerator and on the shelf respectively while TSS increased from 0.064%Brix to 0.435% Brix and 0.578%Brix for sample stored in refrigerator and shelf respectively. Titratable acidity decreased from 2.90 % to 0.20% and 0.50% for samples for the juice stored in the refrigerator and on shelf respectively.All these changes were statistically significant (p<0.05).The sample stored on the shelf lost its organoleptic qualities on the third day with an average value less than 2 for taste, smell and colour. However, the juice stored in the fridge lost its organoleptic qualities at the 7th day with an average value of 3.0, 2.90 and 2.80 for taste, smell andcolour respectively.  From the results, juice extracted from water meloncannot be kept at ambient temperature beyond 3 days without proper refrigeration and an additive. This calls for alternative way of extending its shelf life in the absence of electricity supply using local spice like P. guineenses and to make it available during off season

    Material Selection for Gas Turbine Blade Coating Using GRANTA Material Selector

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    This paper presents the selection of suitable candidate materials for thermal barrier coating of gas turbine blade using GRANTA software. There have been reported cases of gas turbine blade failure in service due to the extreme service conditions. Such failure could possibly have occurred due to poor material selection for thermal barrier coatings on the turbine blade thereby exposing the blade to harsh condition over time. The major adverse effects on these blades are thermal fatigue, high temperature oxidation, hot corrosion, interdiffusion, high cycle fatigue and creep

    Double-stage features extraction for Malays vowel classification using multinomial logistic regression

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    Automatic speech recognition (ASR) has recorded enormous development in both research and implementation such as voice commands to control electronic appliances, video games, interface to voice dictation, assistive leaving for the elderly, and dialogue systems. Rapid development on ASR can be seen on the English language, while duplicating the ASR framework for Malay language is possible, but the work demands endlessly efforts. One of common tools that is able to classify Malay vowels is Multinomial Logistic Regression (MLR). However, careless on estimating the parameters of MLR may lead to producing biased classifier which inappropriate for future classification. Besides, the used on huge number of features for classification sometimes hinder MLR to perform well. This paper outlines a new idea for estimating the unknown MLR parameters with less number of features using a double-stage features extraction based on MLR (DSFE-MLR). The proposed DSFE-MLR extracted 39-MFCC from speech waveform and constructed an MLR using training set. Next, the MLR output of class membership probabilities were further extracted through MLR and evaluated using test set. Empirical evidence on Malay sample of students shows that the DSFE-MLR recorded the highest accuracy compared to other classifiers. Besides, the method is able to recognize each of five Malay vowels correctly. In general, DSFE-MLR provides an increment of accuracy for Malay speech recognition

    Catalytic mechanism of the dehydrogenation of ethylbenzene over Fe-Co/Mg(Al)O derived from hydrotalcites

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    Catalytic mechanism of ethylbenzene dehydrogenation over Fe-Co/Mg(Al)O derived from hydrotalcites has been studied based on the XAFS and XPS catalyst characterization and the FTIR measurements of adsorbed species. Fe-Co/Mg(Al)O showed synergy, whereas Fe-Ni/Mg(Al)O showed no synergy, in the dehydrogenation of ethylbenzene. Ni species were stably incorporated as Ni(2+) in the regular sites in periclase and spinel structure in the Fe-Ni/Mg(Al)O. Contrarily, Co species exists as a mixture of Co(3+)/Co(2+) in the Fe-Co/Mg(Al)O and was partially isolated from the regular sites in the structures with increasing the Co content. Co addition enhanced Lewis acidity of Fe(3+) active sites by forming Fe(3+)-O-Co(3+/2+)(1/1) bond, resulting in an increase in the activity. FTIR of ethylbenzene adsorbed on the Fe-Co/Mg(Al)O clearly showed formations of C-O bond and pi-adsorbed aromatic ring. This suggests that ethylbenzene was strongly adsorbed on the Fe(3+) acid sites via pi-bonding and the dehydrogenation was initiated by alpha-H(+) abstraction from ethyl group on Mg(2+)-O(2-) basic sites, followed by C-O-Mg bond formation. The alpha-H(+) abstraction by O(2-)(-Mg(2+)) was likely followed by beta-H abstraction, leading to the formations of styrene and H(2). Such catalytic mechanism by the Fe(3+) acid-O(2-)(-Mg(2+)) base couple and the Fe(3+)/Fe(2+) reduction-oxidation cycle was further assisted by Co(3+)/Co(2+), leading to a good catalytic activity for the dehydrogenation of ethylbenzene

    Developing a core outcome set for future infertility research : An international consensus development study

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    STUDY QUESTION: Can a core outcome set to standardize outcome selection, collection and reporting across future infertility research be developed? SUMMARY ANSWER: A minimum data set, known as a core outcome set, has been developed for randomized controlled trials (RCTs) and systematic reviews evaluating potential treatments for infertility. WHAT IS KNOWN ALREADY: Complex issues, including a failure to consider the perspectives of people with fertility problems when selecting outcomes, variations in outcome definitions and the selective reporting of outcomes on the basis of statistical analysis, make the results of infertility research difficult to interpret. STUDY DESIGN, SIZE, DURATION: A three-round Delphi survey (372 participants from 41 countries) and consensus development workshop (30 participants from 27 countries). PARTICIPANTS/MATERIALS, SETTING, METHODS: Healthcare professionals, researchers and people with fertility problems were brought together in an open and transparent process using formal consensus science methods. MAIN RESULTS AND THE ROLE OF CHANCE: The core outcome set consists of: viable intrauterine pregnancy confirmed by ultrasound (accounting for singleton, twin and higher multiple pregnancy); pregnancy loss (accounting for ectopic pregnancy, miscarriage, stillbirth and termination of pregnancy); live birth; gestational age at delivery; birthweight; neonatal mortality; and major congenital anomaly. Time to pregnancy leading to live birth should be reported when applicable. LIMITATIONS, REASONS FOR CAUTION: We used consensus development methods which have inherent limitations, including the representativeness of the participant sample, Delphi survey attrition and an arbitrary consensus threshold. WIDER IMPLICATIONS OF THE FINDINGS: Embedding the core outcome set within RCTs and systematic reviews should ensure the comprehensive selection, collection and reporting of core outcomes. Research funding bodies, the Standard Protocol Items: Recommendations for Interventional Trials (SPIRIT) statement, and over 80 specialty journals, including the Cochrane Gynaecology and Fertility Group, Fertility and Sterility and Human Reproduction, have committed to implementing this core outcome set. STUDY FUNDING/COMPETING INTEREST(S): This research was funded by the Catalyst Fund, Royal Society of New Zealand, Auckland Medical Research Fund and Maurice and Phyllis Paykel Trust. The funder had no role in the design and conduct of the study, the collection, management, analysis or interpretation of data, or manuscript preparation. B.W.J.M. is supported by a National Health and Medical Research Council Practitioner Fellowship (GNT1082548). S.B. was supported by University of Auckland Foundation Seelye Travelling Fellowship. S.B. reports being the Editor-in-Chief of Human Reproduction Open and an editor of the Cochrane Gynaecology and Fertility group. J.L.H.E. reports being the Editor Emeritus of Human Reproduction. J.M.L.K. reports research sponsorship from Ferring and Theramex. R.S.L. reports consultancy fees from Abbvie, Bayer, Ferring, Fractyl, Insud Pharma and Kindex and research sponsorship from Guerbet and Hass Avocado Board. B.W.J.M. reports consultancy fees from Guerbet, iGenomix, Merck, Merck KGaA and ObsEva. C.N. reports being the Co Editor-in-Chief of Fertility and Sterility and Section Editor of the Journal of Urology, research sponsorship from Ferring, and retains a financial interest in NexHand. A.S. reports consultancy fees from Guerbet. E.H.Y.N. reports research sponsorship from Merck. N.L.V. reports consultancy and conference fees from Ferring, Merck and Merck Sharp and Dohme. The remaining authors declare no competing interests in relation to the work presented. All authors have completed the disclosure form

    Standardizing definitions and reporting guidelines for the infertility core outcome set: an international consensus development study

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    Study Question Can consensus definitions for the core outcome set for infertility be identified in order to recommend a standardized approach to reporting? Summary Answer Consensus definitions for individual core outcomes, contextual statements, and a standardized reporting table have been developed. What is Known Already Different definitions exist for individual core outcomes for infertility. This variation increases the opportunities for researchers to engage with selective outcome reporting, which undermines secondary research and compromises clinical practice guideline development. Study Design, Size, Duration Potential definitions were identified by a systematic review of definition development initiatives and clinical practice guidelines and by reviewing Cochrane Gynaecology and Fertility Group guidelines. These definitions were discussed in a face-to-face consensus development meeting, which agreed consensus definitions. A standardized approach to reporting was also developed as part of the process. Participants/Materials, Setting, Methods Healthcare professionals, researchers, and people with fertility problems were brought together in an open and transparent process using formal consensus development methods. Main Results and the Role of Chance Forty-four potential definitions were inventoried across four definition development initiatives, including the Harbin Consensus Conference Workshop Group and International Committee for Monitoring Assisted Reproductive Technologies, 12 clinical practice guidelines, and Cochrane Gynaecology and Fertility Group guidelines. Twenty-seven participants, from 11 countries, contributed to the consensus development meeting. Consensus definitions were successfully developed for all core outcomes. Specific recommendations were made to improve reporting. Limitations, Reasons for Caution We used consensus development methods, which have inherent limitations. There was limited representation from low- and middle-income countries. Wider Implications of the Findings A minimum data set should assist researchers in populating protocols, case report forms, and other data collection tools. The generic reporting table should provide clear guidance to researchers and improve the reporting of their results within journal publications and conference presentations. Research funding bodies, the Standard Protocol Items: Recommendations for Interventional Trials statement, and over 80 specialty journals have committed to implementing this core outcome set
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