5,896 research outputs found

    Safety assessment in primary Mycobacterium tuberculosis smear microscopy centres in Blantyre Malawi: A facility based cross sectional survey

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    IntroductionTuberculosis (TB) is caused by Mycobacterium tuberculosis and istransmitted mainly through aerosolization of infected sputum whichputs laboratory workers at risk in spite of the laboratory workersf risk ofinfection being at 3 to 9 times higher than the general public. Laboratorysafety should therefore be prioritized and optimized to provide sufficientsafety to laboratory workers.ObjectiveTo assess the safety for the laboratory workers in TB primary microscopycentres in Blantyre urban.MethodologyTB primary microscopy centers in Blantyre urban were assessed inaspects of equipment availability, facility layout, and work practice, usinga standardized WHO/AFRO ISO 15189 checklist for the developingcountries which sets the minimum safety score at .80%. Each center wasgraded according to the score it earned upon assessment.ResultsOnly one (1) microscopy center out nine (9) reached the minimum safetyrequirement. Four (4) centers were awarded 1 star level, four (4) centerswere awarded 2 star level and only one (1) center was awarded 3 star level.ConclusionIn Blantyre urban, 89% of the Tuberculosis microscopy centers are failingto provide the minimum safety to the laboratory workers. Governmentand other stake holders should be committed in addressing the safetychallenges of TB microscopy centres in the country to ensure safety forthe laboratory workers.RecommendationsIt is recommended that the study be conducted at the regional or nationallevel for both public and private laboratories in order to have a generalpicture of safety in Tb microscopy centres possibly across the country

    Modeling Infiltration Kinetics Of Liquids Into Porous Alumina Preforms

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    MODELING INFILTRATION KINETICS OF LIQUIDS INTO POROUS ALUMINA PREFORMS. Alpha-alumina preform was infiltrated with different infiltrant and pressure for studying the infiltration kinetic. Effects of pre-sintering temperature, type of infiltrant, pressure and multiple infiltrations on the rate of infiltration into porous alumina preforms were described. The pore radius of alumina preform is calculated based on the preform water system by using Washburn model. The pore radius from this model, r of 0.0147 μm is good agreement to the average pore radius found by using mercury porosity measurement, r of 0.0170 μm. The pore radius of 0.0147 μm is used to calculate the rate of infiltration, k. The k factors are 64.83 x 10-5 ms½ and 27.11 x 10-5 ms½ for water and TiCl3 respectively without involving pressure in the calculation. On the other hand, by using pressure, the k factors are 75.14 x 10-5 ms½ and 31.40 x 10-5 ms½ for water and TiCl3 respectively. Other formulas were also included as comparisons. The kinetic of water and titanium trichloride alumina preform system is parabolic in time or linier in square root of time

    Synthesis and characterisation of gel-derived mullite precursors from rice husk silica

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    The sol-gel synthesis and characterization of mullite precursor derived from rice husk silica and aluminum nitrate hydrate [(Al(NO3)3·9H2O] has been investigated. The samples were characterized using Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) coupled with Rietveld analysis, and scanning electron microscopy (SEM). FTIR results showed the presence of Si-O-Si, Al-O-Al, and Si-O-Al functional groups, which were associated with mullite, corundum, quartz, and cristobalite, as verified by XRD analysis. It is concluded that mullite formation started at 1150 °C, and its abundance increased rapidly with an increase in temperature from 1150 to 1350 °C, resulting in increased phase content from 30.9 to 67.7 wt%. Although mullite was formed at a low temperature, the complete reaction between corundum and silica to form mullite was not achieved. This finding demonstrated that rice husk silica is a potential alternative raw material for the production of mullite ceramic

    Cultural-based visual expression: Emotional analysis of human face via Peking Opera Painted Faces (POPF)

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    © 2015 The Author(s) Peking Opera as a branch of Chinese traditional cultures and arts has a very distinct colourful facial make-up for all actors in the stage performance. Such make-up is stylised in nonverbal symbolic semantics which all combined together to form the painted faces to describe and symbolise the background, the characteristic and the emotional status of specific roles. A study of Peking Opera Painted Faces (POPF) was taken as an example to see how information and meanings can be effectively expressed through the change of facial expressions based on the facial motion within natural and emotional aspects. The study found that POPF provides exaggerated features of facial motion through images, and the symbolic semantics of POPF provides a high-level expression of human facial information. The study has presented and proved a creative structure of information analysis and expression based on POPF to improve the understanding of human facial motion and emotion

    Damage and repair classification in reinforced concrete beams using frequency domain data

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    This research aims at developing a new vibration-based damage classification technique that can efficiently be applied to a real-time large data. Statistical pattern recognition paradigm is relevant to perform a reliable site-location damage diagnosis system. By adopting such paradigm, the finite element and other inverse models with their intensive computations, corrections and inherent inaccuracies can be avoided. In this research, a two-stage combination between principal component analysis and Karhunen-Loéve transformation (also known as canonical correlation analysis) was proposed as a statistical-based damage classification technique. Vibration measurements from frequency domain were tested as possible damage-sensitive features. The performance of the proposed system was tested and verified on real vibration measurements collected from five laboratory-scale reinforced concrete beams modelled with various ranges of defects. The results of the system helped in distinguishing between normal and damaged patterns in structural vibration data. Most importantly, the system further dissected reasonably each main damage group into subgroups according to their severity of damage. Its efficiency was conclusively proved on data from both frequency response functions and response-only functions. The outcomes of this two-stage system showed a realistic detection and classification and outperform results from the principal component analysis-only. The success of this classification model is substantially tenable because the observed clusters come from well-controlled and known state conditions

    Electronic structure of superconducting graphite intercalate compounds: The role of the interlayer state

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    Although not an intrinsic superconductor, it has been long--known that, when intercalated with certain dopants, graphite is capable of exhibiting superconductivity. Of the family of graphite--based materials which are known to superconduct, perhaps the most well--studied are the alkali metal--graphite intercalation compounds (GIC) and, of these, the most easily fabricated is the C8{}_8K system which exhibits a transition temperature Tc0.14\bm{T_c\simeq 0.14} K. By increasing the alkali metal concentration (through high pressure fabrication techniques), the transition temperature has been shown to increase to as much as 5\bm 5 K in C2{}_2Na. Lately, in an important recent development, Weller \emph{et al.} have shown that, at ambient conditions, the intercalated compounds \cyb and \cca exhibit superconductivity with transition temperatures Tc6.5\bm{T_c\simeq 6.5} K and 11.5\bm{11.5} K respectively, in excess of that presently reported for other graphite--based compounds. We explore the architecture of the states near the Fermi level and identify characteristics of the electronic band structure generic to GICs. As expected, we find that charge transfer from the intercalant atoms to the graphene sheets results in the occupation of the π\bm\pi--bands. Yet, remarkably, in all those -- and only those -- compounds that superconduct, we find that an interlayer state, which is well separated from the carbon sheets, also becomes occupied. We show that the energy of the interlayer band is controlled by a combination of its occupancy and the separation between the carbon layers.Comment: 4 Figures. Please see accompanying experimental manuscript "Superconductivity in the Intercalated Graphite Compounds C6Yb and C6Ca" by Weller et a

    Using Sat solvers for synchronization issues in partial deterministic automata

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    We approach the task of computing a carefully synchronizing word of minimum length for a given partial deterministic automaton, encoding the problem as an instance of SAT and invoking a SAT solver. Our experimental results demonstrate that this approach gives satisfactory results for automata with up to 100 states even if very modest computational resources are used.Comment: 15 pages, 3 figure

    Sparse Exploratory Factor Analysis

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    Sparse principal component analysis is a very active research area in the last decade. It produces component loadings with many zero entries which facilitates their interpretation and helps avoid redundant variables. The classic factor analysis is another popular dimension reduction technique which shares similar interpretation problems and could greatly benefit from sparse solutions. Unfortunately, there are very few works considering sparse versions of the classic factor analysis. Our goal is to contribute further in this direction. We revisit the most popular procedures for exploratory factor analysis, maximum likelihood and least squares. Sparse factor loadings are obtained for them by, first, adopting a special reparameterization and, second, by introducing additional [Formula: see text]-norm penalties into the standard factor analysis problems. As a result, we propose sparse versions of the major factor analysis procedures. We illustrate the developed algorithms on well-known psychometric problems. Our sparse solutions are critically compared to ones obtained by other existing methods
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