14 research outputs found

    Thermal Properties of Graphene, Carbon Nanotubes and Nanostructured Carbon Materials

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    Recent years witnessed a rapid growth of interest of scientific and engineering communities to thermal properties of materials. Carbon allotropes and derivatives occupy a unique place in terms of their ability to conduct heat. The room-temperature thermal conductivity of carbon materials span an extraordinary large range - of over five orders of magnitude - from the lowest in amorphous carbons to the highest in graphene and carbon nanotubes. I review thermal and thermoelectric properties of carbon materials focusing on recent results for graphene, carbon nanotubes and nanostructured carbon materials with different degrees of disorder. A special attention is given to the unusual size dependence of heat conduction in two-dimensional crystals and, specifically, in graphene. I also describe prospects of applications of graphene and carbon materials for thermal management of electronics.Comment: Review Paper; 37 manuscript pages; 4 figures and 2 boxe

    Normal parameter reduction algorithm in soft set based on hybrid binary particle swarm and biogeography optimizer

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    © 2019, Springer-Verlag London Ltd., part of Springer Nature. Existing classification techniques that are proposed previously for eliminating data inconsistency could not achieve an efficient parameter reduction in soft set theory, which effects on the obtained decisions. Meanwhile, the computational cost made during combination generation process of soft sets could cause machine infinite state, which is known as nondeterministic polynomial time. The contributions of this study are mainly focused on minimizing choices costs through adjusting the original classifications by decision partition order and enhancing the probability of searching domain space using a developed Markov chain model. Furthermore, this study introduces an efficient soft set reduction-based binary particle swarm optimized by biogeography-based optimizer (SSR-BPSO-BBO) algorithm that generates an accurate decision for optimal and sub-optimal choices. The results show that the decision partition order technique is performing better in parameter reduction up to 50%, while other algorithms could not obtain high reduction rates in some scenarios. In terms of accuracy, the proposed SSR-BPSO-BBO algorithm outperforms the other optimization algorithms in achieving high accuracy percentage of a given soft dataset. On the other hand, the proposed Markov chain model could significantly represent the robustness of our parameter reduction technique in obtaining the optimal decision and minimizing the search domain.Published versio

    Systemic lupus erythematosus and ocular involvement: an overview

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    Systemic lupus erythematosus (SLE) is a multisystem autoimmune disease of undefined etiology and with remarkably heterogeneous clinical features. Virtually any organ system can be affected, including the eye. SLE-related eye involvement can be diagnosed in approximately one-third of the patients and is usually indicative of disease activity. An early diagnosis and the adoption of suitable therapeutic measures are necessary to prevent sight-threatening consequences, especially in patients with juvenile SLE. Periocular lesions, such as eyelid involvement and orbital inflammation, are relatively rare and, in case of orbital masses, may require a biopsy control. Keratoconjunctivitis sicca or secondary Sjogren's syndrome is the most frequent ophthalmic manifestation of SLE. According to its variable severity, lubricating tear drops may be sufficient in mild cases, whereas cyclosporine-A ophthalmic solution, glucocorticoids (GCs), methotrexate, and/or other immunosuppressive drugs may be required in the more severe cases. Partial occlusion of the lacrimal punctum by thermal cautery is rarely applied. Although uncommon, episcleritis and scleritis can sometimes be detected as an initial finding of SLE and reveal themselves as moderate to intense ocular pain, redness, blurred vision, and lacrimation. Unilateral or more often bilateral retinopathy is responsible for visual loss of variable severity and is ascribed to vasculitis of the retinal capillaries and arterioles. In addition to the combined treatment suitable for all patients with active SLE, intravitreal bevacizumab should be considered in cases of severe vaso-occlusive retinopathy and laser photocoagulation in cases of neovascularization. Purtscher-like retinopathy is likely ascribable to the formation of microemboli that results in retinal vascular occlusion and microvascular infarcts. Choroidal disease is characterized by monolateral or bilateral blurred vision. Because of the choroidal effusion, retinal detachment and secondary angle-closure glaucoma may occur. Ischemic optic neuropathy is characterized by acute-onset and progressive binocular visual impairment as a consequence of occlusion of the small vessels of the optic nerves due to immune complex vasculitis. Intravenous GC boluses followed by oral GCs and/or, in case of recurrence, intravenous cyclophosphamide and/or rituximab are commonly employed. Neovascularization can be treated by intravitreal bevacizumab and progression of retinal ischemic areas by retinal laser photocoagulation. Ocular adverse events (AE) have been described following the long-term administration of one or more of the drugs presently used for the treatment of SLE patients. Posterior subcapsular cataracts and secondary open-angle glaucoma are common AE of the prolonged GC administration. The long-term administration of hydroxychloroquine (HCQ) sulfate is well known to be associated with AE, such as vortex keratopathy and in particular the often irreversible and sight-threatening maculopathy. Length of administration > 5 years, > 1000 g total HCQ consumption, > 6.5 mg/kg daily dosing, coexistence of renal disease, and preexisting maculopathy are all considered risk factors for HCQ-induced retinopathy. Ocular AE of additional immunosuppressive and biological agents are still poorly known, given the worldwide more limited experience with their long-term use.A thorough ophthalmological control is strongly recommended at closer intervals for all SLE patients, in step with the total length of exposure to the drugs and the cumulative dose administered
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