50 research outputs found

    Studies on the Enrichment Feasibility of Rare Earth-Bearing Minerals in Mine Tailings

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    This Study Aimed to Investigate the Potential of Enrichment of Rare-Earth-Bearing Minerals in Historic Mine Tailing using the Froth Flotation Process. Characterization Studies Indicated that Tailings Contained 11,000 Ppm of Rare Earth Elements (REEs). the Major Mineral in the Tailings Was Apatite at ~84%, Which Was Associated with Iron Oxides (~16%). TESCAN\u27s Integrated Mineral Analysis (TIMA) Showed that Monazite Was the Main REE Mineral, and 69% of Monazite Was Locked in Apatite Grains. Characterization Studies Suggested that the Separation of REEs-Bearing Apatite from Iron Oxides is Possible using Froth Flotation, Wherein Apatite Was Floated and Iron Oxides Were Depressed. Zeta Potential Experiments Were Conducted to Understand the Behavior of the Main Minerals in the Feed When Selected Depressants of Iron Oxides Were Added. Depressants Included Corn Starch, Sodium Metasilicates, Polyacrylamide (PAM), Hybrid Polyacrylamide (HyPAM), and Chitosan. Zeta Potential Results Suggested that Chitosan and Polyacrylamide-Based Polymers Had the Strongest Adsorption on Magnetite at PH 7 and PH 9, Respectively, as Indicated by the Large Shift in the Zeta Potential of Magnetite Suspensions. Flotation Results Were Consistent with Zeta Potential Findings and Showed that Hy-PAM and Chitosan Had the Best Depression Efficiency of Iron Oxides at PH 9 and PH 7, Respectively

    Towards a teacher-centric approach for multi-touch surfaces in classrooms

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    The potential of tabletops to enable simultaneous interaction and face-to-face collaboration can provide novel learning opportunities. Despite significant research in the area of collaborative learning around tabletops, little attention has been paid to the integration of multi-touch surfaces into classroom layouts and how to employ this technology to facilitate teacher-learner dialogue and teacher-led activities across multi-touch surfaces. While most existing techniques focus on the collaboration between learners, this work aims to gain a better understanding of practical challenges that need to be considered when integrating multi-touch surfaces into classrooms. It presents a multi-touch interaction technique, called TablePortal, which enables teachers to manage and monitor collaborative learning on students' tables. Early observations of using the proposed technique within a novel classroom consisting of networked

    Relative and Absolute Mappings for Rotating Remote 3D Objects on Multi-Touch Tabletops

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    The use of human fingers as an object selection and manipulation tool has raised significant challenges when interacting with direct-touch tabletop displays. This is particularly an issue when manipulating remote objects in 3D environments as finger presses can obscure objects at a distance that are rendered very small. Techniques to support remote manipulation either provide absolute mappings between finger presses and object transformation or rely on tools that support relative mappings t o selected objects. This paper explores techniques to manipulate remote 3D objects on direct-touch tabletops using absolute and relative mapping modes. A user study was conducted to compare absolute and relative mappings in support of a rotation task. Overall results did not show a statistically significant difference between these two mapping modes on both task completion time and the number of touches. However, the absolute mapping mode was found to be less efficient than the relative mapping mode when rotating a small object. Also participants preferred relative mapping for small objects. Four mapping techniques were then compared for perceived ease of use and learnability. Touchpad, voodoo doll and telescope techniques were found to be comparable for manipulating remote objects in a 3D scene. A flying camera technique was considered too complex and required increased effort by participants. Participants preferred an absolute mapping technique augmented to support small object manipulation, e.g. the voodoo doll technique

    Architectures and Key Technical Challenges for 5G Systems Incorporating Satellites

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    Satellite Communication systems are a promising solution to extend and complement terrestrial networks in unserved or under-served areas. This aspect is reflected by recent commercial and standardisation endeavours. In particular, 3GPP recently initiated a Study Item for New Radio-based, i.e., 5G, Non-Terrestrial Networks aimed at deploying satellite systems either as a stand-alone solution or as an integration to terrestrial networks in mobile broadband and machine-type communication scenarios. However, typical satellite channel impairments, as large path losses, delays, and Doppler shifts, pose severe challenges to the realisation of a satellite-based NR network. In this paper, based on the architecture options currently being discussed in the standardisation fora, we discuss and assess the impact of the satellite channel characteristics on the physical and Medium Access Control layers, both in terms of transmitted waveforms and procedures for enhanced Mobile BroadBand (eMBB) and NarrowBand-Internet of Things (NB-IoT) applications. The proposed analysis shows that the main technical challenges are related to the PHY/MAC procedures, in particular Random Access (RA), Timing Advance (TA), and Hybrid Automatic Repeat reQuest (HARQ) and, depending on the considered service and architecture, different solutions are proposed.Comment: Submitted to Transactions on Vehicular Technologies, April 201

    PHYSIOLOGICAL ROLE OF HUNTERIA UMBELLATA FRUIT EXTRACT ON HORMONAL AND RENAL PROFILE IN CADMIUM INDUCED TOXICITY MALE WISTAR RATS

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    The present study was design with an objective to investigate the toxicity level of cadmium chloride on hormonal and biochemical markers and the restoration strength of Hunteria umbellata aqueous fruit extract administered at various dosage level of treatment in induced male wistar rats. The parameters investigated includes LH,FSH, Testosterone, Prolactin, Urea, Creatinine, and Uric acid following 0.07ml and 0.06ml single dose cdcl₂ induction of group2 and group3.However group4 was administered 0.03ml cdcl₂ daily while group1 serve as the control.Group2 was treated at 400mg/kg and group3 at 200mg/kg extract daily while group4 received no treatment but feed  and water ad libidum.Results from this study shows higher FSH (0.52 m/u/ml), LH (1.32 m/u/ml) and Prolactin (1.17ng/ml) among group3 treated at 200mg/kg extract of the Hunteria umbellata fruit. This was closely followed by group2 treated at 400mg/kg body weight ie LH (0.74 m/u/ml), Prolactin (1.04ng/ml) compared with group4 FSH of (0.25 m/u/ml), LH (0.37 m/u/ml) and control. The testosterone level was higher in group2 (4.65 ng/ml) compared with other groups. The study shows higher renal markers in group4 administered cdcl₂ without treatment. However in group2 treated at 400mg/kg extract had decreased renal markers followed by group3 treated at 200mg/kg extract.ie results from this study further indicate higher renal indices among group4 administered oral cdcl₂ daily with urea having (10.70mmol/l), Creatinine (178.5µmol/l) and uric acid (430.0µmol/l) compared with the control group of (9.6mmol/l),(165µmol/l) and (375µmol/l) respectively. This study have shown clearly the physio-pharmacological effect of Hunteria umbellata fruit extract in increasing glomerullar filtration rate to clear off these parameters from the blood and restore normal renal function

    End-to-End QoS Measurement over a DVB-RCS Satellite Network

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    Satellites play an important role in the future network due to their wide area coverage and for providing connectivity in remote regions of the world. This paper presents the end-to-end quality of service (QoS) measurements taken employing a European Space Agency (ESA) testbed over DVB-RCS infrastructure, in collaboration with University of Surrey, UK. The applications chosen for these experiments are file transfer (FTP), web browsing (HTTP) and video streaming. File transfer and web browsing require reliable transport mechanism as a corrupted bit will hinder the intact data delivery. Therefore, these applications use transmission control protocol (TCP) as the transport protocol. TCP involves a three way handshake, which introduces extra delay during data transfer. Video streaming is a real time application. It is time-sensitive and requires lesser reliability compared to FTP and Web services. Hence, it employs user datagram protocol (UDP) at the transport layer, which do not offer any guarantee of reliable data delivery but timely. The parameters that have been used to evaluate quality of service (QoS) are packet delivery time, file download time, round trip delay, packet sizes and packet loss. The paper presented measurement results and comparative analysis of the QoS of the applications over the DVB-RCS testbed

    Role of Caustic Addition in Bitumen-Clay Interactions

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    Coating of bitumen by clays, known as slime coating, is detrimental to bitumen recovery from oil sands using the warm slurry extn. process. Sodium hydroxide (caustic) is added to the extn. process to balance many competing processing challenges, which include undesirable slime coating. The current research aims at understanding the role of caustic addn. in controlling interactions of bitumen with various types of model clays. The interaction potential was studied by quartz crystal microbalance with dissipation monitoring (QCM-D). After confirming the slime coating potential of montmorillonite clays on bitumen in the presence of calcium ions, the interaction of kaolinite and illite with bitumen was studied. To represent more closely the industrial applications, tailings water from bitumen extn. tests at different caustic dosage was used. At caustic dosage up to 0.5 wt % oil sands ore, a negligible coating of kaolinite on the bitumen was detd. However, at a lower level of caustic addn., illite was shown to attach to the bitumen, with the interaction potential decreasing with increasing caustic dosage. Increasing concn. of humic acids as a result of increasing caustic dosage was identified to limit the interaction potential of illite with bitumen. This fundamental study clearly shows that the crit. role of caustics in modulating interactions of clays with bitumen depends upon the type of clays. Thus, clay type was identified as a key operational variable

    A blood RNA transcriptome signature for COVID-19.

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    BACKGROUND: COVID-19 is a respiratory viral infection with unique features including a more chronic course and systemic disease manifestations including multiple organ involvement; and there are differences in disease severity between ethnic groups. The immunological basis for disease has not been fully characterised. Analysis of whole-blood RNA expression may provide valuable information on disease pathogenesis. METHODS: We studied 45 patients with confirmed COVID-19 infection within 10 days from onset of illness and a control group of 19 asymptomatic healthy volunteers with no known exposure to COVID-19 in the previous 14 days. Relevant demographic and clinical information was collected and a blood sample was drawn from all participants for whole-blood RNA sequencing. We evaluated differentially-expressed genes in COVID-19 patients (log2 fold change ≥ 1 versus healthy controls; false-discovery rate  0.05). CONCLUSIONS: The whole-blood transcriptome of COVID-19 has overall similarity with other respiratory infections but there are some unique pathways that merit further exploration to determine clinical relevance. The approach to a disease score may be of value, but needs further validation in a population with a greater range of disease severity

    Medication errors in the Middle East countries: a systematic review of the literature

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    Background: Medication errors are a significant global concern and can cause serious medical consequences for patients. Little is known about medication errors in Middle Eastern countries. The objectives of this systematic review were to review studies of the incidence and types of medication errors in Middle Eastern countries and to identify the main contributory factors involved. Methods: A systematic review of the literature related to medication errors in Middle Eastern countries was conducted in October 2011 using the following databases: Embase, Medline, Pubmed, the British Nursing Index and the Cumulative Index to Nursing & Allied Health Literature. The search strategy included all ages and languages. Inclusion criteria were that the studies assessed or discussed the incidence of medication errors and contributory factors to medication errors during the medication treatment process in adults or in children. Results: Forty-five studies from 10 of the 15 Middle Eastern countries met the inclusion criteria. Nine (20%) studies focused on medication errors in paediatric patients. Twenty-one focused on prescribing errors, 11 measured administration errors, 12 were interventional studies and one assessed transcribing errors. Dispensing and documentation errors were inadequately evaluated. Error rates varied from 7.1% to 90.5% for prescribing and from 9.4% to 80% for administration. The most common types of prescribing errors reported were incorrect dose (with an incidence rate from 0.15% to 34.8% of prescriptions), wrong frequency and wrong strength. Computerised physician rder entry and clinical pharmacist input were the main interventions evaluated. Poor knowledge of medicines was identified as a contributory factor for errors by both doctors (prescribers) and nurses (when administering drugs). Most studies did not assess the clinical severity of the medication errors. Conclusion: Studies related to medication errors in the Middle Eastern countries were relatively few in number and of poor quality. Educational programmes on drug therapy for doctors and nurses are urgently needed
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