129 research outputs found
Classification of two and three dimensional Lie super-bialgebras
Using adjoint representation of Lie superalgebras, we obtain the matrix form
of super-Jacobi and mixed super-Jacobi identities of Lie superbialgebras. By
direct calculations of these identities, and use of automorphism supergroups of
two and three dimensional Lie superalgebras, we obtain and classify all two and
three dimensional Lie superbialgebras.Comment: 15 page
Assessment of human-structure interaction on a lively lightweight GFRP footbridge
This is the author accepted manuscript; the final version is available from Elsevier via the DOI in this record.Human activities and occupancy can induce excessive structural vibrations. Human-structure interaction (HSI) can significantly affect responses. However, this phenomenon is not accounted for in many design guidelines due to lack of experimental studies. Concurrently, there is increasing application of lightweight high-strength materials such as glass fibre reinforced polymer (GFRP). The vibration sensitivity of such structures is not yet well known, despite the expectation that it could be important due to high human-to-structure mass ratio. This paper examines the effect of HSI on the vibration response prediction of a lively lightweight GFRP footbridge, and it compares the results to those from a heavy concrete-composite footbridge. An extensive ensemble of test trials was conducted, accompanied by a survey on vibration perception by the walkers. The influence of HSI on the lightweight bridge vibration response is quantified. It is found that the non-interacting moving force models produce poor predictions, especially for the GFRP bridge. It is also found that vibration of the bridge had a strong influence on walking force, and to a lesser extent on the dynamics of the human-structure system. Finally, it is found that a response factor of about 2 is appropriate for determining the vibration tolerance level by walkers.Engineering and Physical Sciences Research Council (EPSRC
Non-linear inelastic analysis of steel arches at elevated temperatures
An innovative non-discretisation mechanical-based method is developed in this paper to analyse a steel arch at elevated temperatures so that its behaviour can be quantified. The steel arch has a generic but singly-symmetric cross-section with elastic and plastic parts,and it is subjected to an arbitrary thermal profile which varies along the length of the arch as well as through the depth of the cross-section. The effects of geometric and material non-linearity as well as potential catenary action which can occur at high temperatures are taken into account in the formulation.The efficiency and accuracy of the generic model developed is demonstrated by a comparison with a finite element model undertaken using ABAQUS. The proposed method is then utilised to elucidate some significant factors,such as the magnitude of the temperature at bottom fibre of the cross-section as well as the ratio of the temperature at the top fibre to that at the bottom fibre, on the response of a steel arch member during fire loading. The proposed model provides a computationally superior formulation to that of commercial finite element packages,and forms a platform which can be used for structural steel arch design and evaluation in the development of codified approaches to fire design on a performance basis
New trends on microbiological water treatment.
Silver nanoparticle-decorated porous polypropylene filter is prepared by physical vapor deposition method using a modified Balzers 760 coating machine. Silver nanoparticles were generated by electron beam bombardment of the silver metal. A 45nm layer of the silver nanoparticles were subsequently deposited on the polypropylene filter homogenously. The nano silver-coated filters were characterized using scanning electron microscopy, transmission electron microscopy and atomic force microscopy. The antibacterial efficiency of the nano silver-coated filters was evaluated using a custom- made experimental set up and the membrane filter method. A zone of inhibition test was also performed to compare the bactericidal effect of coated versus non-coated filters. At a flow rate of 3L/hr, the output count of Escherichia coli was zero after 6.5 hours filtration when the input water had a bacterial load of 103 colony-forming units (cfu) per milliliter. The inductively coupled plasma/mass spectrometry (ICP/MS) results showed that the 45nm layer of the silver nanoparticles are stable on the water filter and are not washed away by water flow even after 6.5h filtration
Effects of intravenous Semelil (ANGIPARS�) on diabetic foot ulcers healing: A multicenter clinical trial
Some diabetic foot ulcers, which are notoriously difficult to cure, are one of the most common health problems in diabetic patients .There are several surgical and medical options which already have been introduced for treatment of diabetic foot ulcers, so some patient will require amputation. The purpose of this study was to evaluate the efficacy of intravenous Semelil (ANGIPARS�), a naive herbal extract to accelerate healing of diabetic foot ulcers. A multi-centric randomized controlled trial was conducted to evaluate intravenous Semelil for healing of diabetic foot ulcers. Sixteen diabetic patients were treated with intravenous Semelil, and nine other patients were treated with placebo as control group. Both groups were otherwise treated by wound debridement and irrigation with normal saline solution, systemic antibiotic therapy and daily wound dressing. Before and after intervention, the foot ulcer surface area was measured, by digital photography, mapping and planimetry. After 4 weeks, the mean foot ulcer surface area decreased from 479.93±379.75 mm2 to 198.93±143.75 mm2 in the intervention group (p = 0.000) and from 766.22±960.50 mm2 to 689.11±846.74 mm2 in the control group (p = 0.076). Average wound closure in the treatment group was significantly greater than placebo group (64 vs. 25, p= 0.015). This herbal extract by intravenous rout in combination with conventional therapy is more effective than conventional therapy by itself probably without side effect. However, further studies are required in the future to confirm these results in larger population
Relationship between maximum clot firmness in ROTEM® and postoperative bleeding after coronary artery bypass graft surgery in patients using clopidogrel
Background: The aim of the present study was to investigate the relationship between maximum clot firmness (MCF) in rotational thromboelastometry (ROTEM®) and postoperative bleeding in patients on clopidogrel after emergency coronary artery bypass graft surgery (CABG). Methods: This observational study recruited 60 patients posted for emergency CABG following unsuccessful primary percutaneous coronary intervention (PCI) while on 600 mg of clopidogrel. The study population was divided into 2 groups on the basis of their MCF in the extrinsically activated thromboelastometric (EXTEM) component of the (preoperative) ROTEM® test: patients with MCF <50 mm (n = 16) and those with MCF �50 mm (n = 44). Postoperative chest tube drainage amount, need for blood product transfusion, postoperative complications, and duration of mechanical ventilation after CABG were recorded. Results: No significant differences were observed between the two groups regarding duration of surgery, cardiopulmonary bypass, and aortic cross-clamp time. Chest tube drainage at 6, 12, and 24 h after Intensive Care Unit admission were significantly higher in the patients with MCF below 50 mm. The need for blood product transfusion was higher in the group with MCF <50 mm. In patients who experienced postoperative bleeding of 1000 mL or more, the ROTEM® parameters of INTEM (Intrinsically activated thromboelastomery) and MCF, EXTEM and MCF, and HEPTEM (INTEM assay performed in the presence of heparinase) MCF (but not FIBTEM (Thromboelastometric assay for the fibrin part of the clot) values) were significantly lower than those with postoperative bleeding <1000 mL (P � 0.05). Conclusions: When platelet aggregometry is not available, the ROTEM® test could be useful for the prediction of increased risk bleeding after emergency CABG in patients who have received a loading dose of clopidogrel. © 2018 Annals of Cardiac Anaesthesia | Published by Wolters Kluwer - Medknow
New trends in microbiological water treatment
Clean water is essential to human life as well as the rest of the ecosystem. Nowadays, we are experiencing difficulties in responding to the increasing demand for reliable water sources. There are many approaches available for the disinfection of water. Each method has some practical difficulties and disadvantages. Nanotechnology is an emerging advanced technology with significant potential in various fields including solving water purification problems. Using nanotechnology methods it is possible to convert metal ions into nanoparticles for medical and non-medical [1] applications. The major property that makes nanoparticles attractive is that they are extremely small in size (1-100nm), which provides them with a higher surface area per unit mass. Nanomaterials often show unique and considerably enhanced physical, chemical and biological properties compared to their macro-scaled counterpart
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