103 research outputs found

    Novel Electromagnetic Sensors Embedded in Reinforced Concrete Beams for Crack Detection

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    This paper investigates the possibility of applying novel microwave sensors for crack detection in reinforced concrete structures. Initially, a microstrip patch antenna with a Split Ring Resonator (SRR) structure was designed, simulated and fabricated. To evaluate the sensor’s performance, a series of structural tests were carried out and the sensor responses were monitored. Four reinforced concrete (RC) beam specimens, designed according to the European Standards, were tested under 3-point bending. The load was applied incrementally to the beams and the static responses were monitored via the use of a load cell, displacement transducers and crack width gauges (Demec studs). In parallel, signal readings from the microwave sensors, which were employed prior to casting of the concrete, located at the neutral axis at the mid-span of the beam, were recorded at various load increments. The microwave measurements were analysed and compared with those from crack width gauges. A strong linear relationship between the crack propagation and the electromagnetic signal across the full captured spectrum was found, demonstrating the technique’s capability and its potential for further research offering a reliable, low cost option for structural health monitoring (SHM)

    Removal of phosphate from River water using a new baffle plates electrochemical reactor

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    During the last 50 years, the human activities have significantly altered the natural cycle of phosphate in this planet, causing phosphate to accumulate in the freshwater ecosystems of some countries to at least 75% greater than preindustrial levels, which indicates an urgent need to develop efficient phosphate treatment methods. Therefore, the current study investigates the removal of phosphate from river water using a new electrochemical cell (PBPR). This new cell utilises perforated baffle plates as a water mixer rather than magnetic stirrers that require power to work. This study investigates the influence of key operational parameters such as initial pH (ipH), current density (Ј), inter-electrode distance (ID), detention time (t) and initial phosphate concentration (IC) on the removal efficiency, and influence of the electrocoagulation process on the morphology of the surface of electrodes. Overall, the results showed that the new reactor was efficient enough to reduce the concentration of phosphate to the permissible limits. Additionally, SEM images showed that the Al anode became rough and nonuniform due to the production of aluminium hydroxides. The main advantages of the electrocoagulation technique are: 1- The EC method does not produce secondary pollutants as it does not required chemical additives, while other traditional treatment methods required either chemical or biological additives [[1], [2], [3], [4]]. 2- It has a large treatment capacity and a relatively short treatment time in comparison with other treatment methods, such as the biological methods [1,[5], [6], [7]]. 3- The EC method produces less sludge than traditional treatment traditional chemical and biological treatment methods [8,9]. EC technology, like any other treatment method, has some drawbacks that could limit its performance. For instance, it still has a clear deficiency in the variety of reactor design, and the electrodes should be periodically replaced as they dissolve into the solution due to the oxidation process [2,10]

    In vivo analgesic effect of aqueous extract of Tamarindus indica L. fruits.

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    To study the effects of Tamarindus indica L. aqueous fruit extract on the antinociceptive activities in rodent models. Methods: The analgesic effect was evaluated using acetic acid-induced writhing, hot plate and formalin tests. Results: The extract (60–600 mg/kg) significantly (p < 0.05) inhibited the writhing test in a dose-dependent manner with the percentage of analgesia recorded between 51.8 and 74.1%. In addition, the extract also significantly (p < 0.05) increased the latency time in the hot plate test in a dose-dependent manner. Further study showed that the extract elicited inhibitory activity in both the early and late phases of the formalin test. Moreover, pretreatment with 5 mg/kg naloxone, a nonselective opioid receptor antagonist, significantly (p < 0.05) modified the antinociceptive effect of the extract in all tests. Conclusion: The aqueous extract of T. indica possesses potential antinociceptive activity at both the peripheral and central levels, which are mediated via activation of the opioidergic mechanism

    M2M Communication in Virtual Sensor Network for SHAAL

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    Machine-to-Machine (M2M) communication has led to a new paradigm of Internet of Things (IoT). The future of M2M communication in smart home lies in the aggregation and allocation of resources and service provisioning of diverse applications using different radio technologies. M2M communication may operate on the virtual sensor network to provide independent applications running on heterogeneous network simultaneously. M2M is going to play a major role in the area of Smart Home and Ambient Assisted Living (SHAAL) providing assistance to the elderly people with smart sensors that monitor the home environment and provides aid health monitoring to human requiring medical assistance. The current state of the art frameworks are dedicated to specific applications with the support of single radio network with limited service provisioning options. However, in order to fully exploit the resources in this paper we present a service provisioning framework realization of M2M in virtual sensor network for SHAAL, which allows independent parties to work together in a secure and reliable manner. In addition to this, the framework is designed to include benefits of Service Oriented Architecture (SOA) and Resource Oriented Architecture (ROA) along with the use of different low power, low data rate protocols. A middleware is used as a platform to link the underlying virtual networks with various applications. The network virtualization approach is adopted to design an efficient middleware framework that can effectively discover and manage the underlying network resources and provide services at home gateway. The framework will be used as the basis for the development of the SHAAL networked system

    Asymmetric patch element reflectarray with dual linear and dual circular polarization

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    A reflectarray antenna consisting of asymmetrical patch elements is proposed, which is capable of producing dual linear and dual circular polarized operation at 26 GHz frequency. The main purpose of this design is to support four different polarizations using the same patch element. The proposed reflectarray has a single layer configuration with a linearly polarized feed and circular ring slots in the ground plane. Asymmetric patch element is designed from a square patch element by tilting its one vertical side to some optimized inclination. A wide reflection phase range of 600° is obtained with the asymmetric patch element during unit cell measurements. A 332 element circular aperture reflectarray is designed with the proposed configuration and experimentally validated with a linearly polarized prime feed configuration. Two different orientations of mirror and non-mirror asymmetric patch elements on the surface of reflectarray are analyzed. Dual linear polarization is obtained with the mirror orientation of the asymmetric patch elements on the surface of reflectarray. Alternatively, asymmetric patch elements without mirror orientation are demonstrated to produce dual circular polarization with the same linearly polarized feed. A maximum measured gain of 24.4 dB and 26.1 dB is achieved for dual linear and dual circular polarization, respectively. Their respective measured efficiencies are 28% and 41.3%, which are supported by a maximum −3 dB gain bandwidth of 13.8% and 11.5%. The circular polarization operation of the reflectarray is also supported by a 6 dB axial ratio bandwidth of 9.2%. The proposed asymmetric patch reflectarray antenna with polarization diversity, wide bandwidth and high gain is suitable to be used in many high frequency applications of 5G communication

    High prevalence of urinary schistosomiasis in two communities in South Darfur: implication for interventions

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    <p>Abstract</p> <p>Background</p> <p>There are few data on the prevalence of schistosomiasis in Darfur. We conducted this study in response to reports of 15 laboratory confirmed cases of schistosomiasis and visible haematuria among children from two communities in South Darfur. The aim of the study was to estimate the prevalence of schistosomiasis in the area and to decide on modalities of intervention.</p> <p>Methods</p> <p>A cross-sectional survey involving 811 children and adults from schools and health facilities was conducted in two communities of South Darfur in March 2010. Urine samples were collected and examined for ova of <it>Schistosoma haematobium </it>using a sedimentation technique. A semi-structured format was used to collect socio-demographic characteristics of the participants.</p> <p>Results</p> <p>Eight hundred eleven (811) urine samples were collected, 415 from Alsafia and 396 from Abuselala. Of the collected samples in 56.0% (95% Confidence Interval (CI); 52.6-59.4) <it>Schistosoma </it>eggs were found. The prevalence was high in both Abuselala 73.3% (95% CI; 68.9-77.6) and Alsafia 39.5% (95% CI; 34.8-44.2). More males (61.7%, 95%CI; 56.5-64.9) were infected than females (52.1%, 95%CI; 48.2-56.0). Children in the age group 10-14 has the highest (73.0%, 95%CI; 68.7-77.2) infection rate. School age children (6-15 years) are more likely to be infected than those >15 years (Adjusted Odds Ratio (AOR) = 2.70, 95% CI; 1.80-4.06). Individuals in Abuselala are more likely to be infected than those who live in Alsafia (AOR = 4.3, 95% CI; 3.2-5.9).</p> <p>Conclusion</p> <p>The findings of this study indicate that <it>S. hematobium </it>is endemic in Alsafia and Abuselala South Darfur in Sudan with a high prevalence of infection among older children. This signifies the importance of urgent intervention through Mass Drug Administration (MDA) to halt the infection cycle and tailored health messages to targeted groups. Based on the findings MDA was conducted in the villages.</p

    Electrocoagulation as a green technology for phosphate removal from River water

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    The current study investigates the removal of phosphate from water using a new baffle plates aluminium-based electrochemical cell (PBPR) taking consideration the influence of key operating parameters. This new cell utilises perforated baffle plates as a water mixer rather than magnetic stirrers that require extra power to work. As this unit is new, a comprehensive study has been carried to assess it performance. This study also includes preliminary estimates of the reactor’s operating costs, the amount of H2 gas produced and the yieldable energy from it. SEM (scanning electron microscope) was used to investigate the influence of the electrocoagulation process on the morphology of the surface of aluminium electrodes, and an empirical model developed to reproduce the phosphate removal process. The results showed that 99% of phosphate was removed within 60 minutes of electrolysis at an initial pH (ipH) of 6, inter-electrode distance (ID) of 0.5 cm, current density (J) of 6 mA/cm2, initial concentration of phosphate (IC) of 100 mg/L, and minimum operating cost of 0.503 US $/m3. The electrochemical cell produced enough H2 gas to generate 4.34 kWh/m3 of power. Statistically, it was proved that the influence of the operating parameters on phosphate removal could be modelled with an R2 of 0.882, the influence of these operating parameters on phosphate removal following the order: t>J>IC>ipH >ID. Finally, SEM images showed that after several electrolysing runs, the Al anode became rough and nonuniform which could be related to the production of aluminium hydroxides

    Encapsulated deep eutectic solvent for esterification of free fatty acid

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    A novel encapsulated deep eutectic solvent (DES) was introduced for biodiesel production via a two-step process. The DES was encapsulated in medical capsules and were used to reduce the free fatty acid (FFA) content of acidic crude palm oil (ACPO) to the minimum acceptable level (< 1%). The DES was synthesized from methyltriphenylphosphonium bromide (MTPB) and p-toluenesulfonic acid (PTSA). The effects pertaining to different operating conditions such as capsule dosage, reaction time, molar ratio, and reaction temperature were optimized. The FFA content of ACPO was reduced from existing 9.61% to less than 1% under optimum operating conditions. This indicated that encapsulated MTPB-DES performed high catalytic activity in FFA esterification reaction and showed considerable activity even after four consecutive recycling runs. The produced biodiesel after acid esterification and alkaline transesterification met the EN14214 international biodiesel standard specifications. To our best knowledge, this is the first study to introduce an acidic catalyst in capsule form. This method presents a new route for the safe storage of new materials to be used for biofuel production. Conductor-like screening model for real solvents (COSMO-RS) representation of the DES using σ-profile and σ-potential graphs indicated that MTPB and PTSA is a compatible combination due to the balanced presence and affinity towards hydrogen bond donor and hydrogen bond acceptor in each constituent

    Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

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    BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London
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