215 research outputs found

    A Comparative Study of Different Phase Detrending Algorithms for Scintillation Monitoring

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    Rapid and sudden fluctuations of phase and amplitude in Global Navigation Satellite System (GNSS) signals due to diffraction of the ionosphere phase components when signals passing through small-scale irregularities (less than hundreds meters) are commonly so-called ionospheric scintillation. The aim of the paper is to analyze the implementation and compare the performance of different phase detrending algorithms to improve scintillation monitoring. Three different phase detrending methods, namely, three cascaded second-order high pass filters, six order Butterworth filter conducted by cascading six first-order high pass Butterworth filters, and Fast Iterative Filter (FIF) are considered in this paper. The study exploits real GNSS signals (GPS L1, Galileo E1b) affected by significant phase scintillation effects, collected in early September 2017 at Brazilian Centro de Radioastronomia e Astrofisica Mackenzie (CRAAM) monitoring station and at Adventdalen (Svalbard, Norway) research station. In this study, a software defined radio (SDR) based GNSS receiver is used to process GNSS signals and to implement the aforementioned detrending algorithms

    The effect of aromatherapy massage with lavender and chamomile oil on anxiety and sleep quality of patients with burns

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    Introduction: Regarding the importance of anxiety management and improvement of the quality of sleep in patients with burn injuries, this study aimed to determine the effect of aromatherapy massage (using aromatic oils of lavender and chamomile) on the anxiety and sleep quality of the patients with burn injuries. Method: In a quasi-experimental study, 105 patients with burns were recruited by convenience sampling method and then assigned into three groups (control, placebo massage, and combined aromatic oil massage). The study intervention was performed 20 min before bedtime in three sessions, within a week. The control group was only under daily routine care. The study data were collected using the Persian version of Spielberg's anxiety scale and the Pittsburgh Sleep Quality Inventory. Descriptive and inferential statistical tests were used to analyze the data in SPSS version 20. Results: The results showed a significant difference among the three groups in terms of anxiety score (P < 0.001) and in terms of sleep quality after the intervention (P = 0.027). Conclusion: Since the aromatherapy massage as a non-pharmacological and simple method can improve the anxiety and quality of sleep in patients with burns, it is suggested that nurses and burn medical care team apply it to reduce burn patients� anxiety and promote their sleep quality. Applying massage alone also reduces anxiety in burn survivors. © 2019 Elsevier Ltd and ISB

    Dynamics of levitated nanospheres: towards the strong coupling regime

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    The use of levitated nanospheres represents a new paradigm for the optomechanical cooling of a small mechanical oscillator, with the prospect of realising quantum oscillators with unprecedentedly high quality factors. We investigate the dynamics of this system, especially in the so-called self-trapping regimes, where one or more optical fields simultaneously trap and cool the mechanical oscillator. The determining characteristic of this regime is that both the mechanical frequency ωM\omega_M and single-photon optomechanical coupling strength parameters gg are a function of the optical field intensities, in contrast to usual set-ups where ωM\omega_M and gg are constant for the given system. We also measure the characteristic transverse and axial trapping frequencies of different sized silica nanospheres in a simple optical standing wave potential, for spheres of radii r=20500r=20-500\,nm, illustrating a protocol for loading single nanospheres into a standing wave optical trap that would be formed by an optical cavity. We use this data to confirm the dependence of the effective optomechanical coupling strength on sphere radius for levitated nanospheres in an optical cavity and discuss the prospects for reaching regimes of strong light-matter coupling. Theoretical semiclassical and quantum displacement noise spectra show that for larger nanospheres with r100r \gtrsim 100\,nm a range of interesting and novel dynamical regimes can be accessed. These include simultaneous hybridization of the two optical modes with the mechanical modes and parameter regimes where the system is bistable. We show that here, in contrast to typical single-optical mode optomechanical systems, bistabilities are independent of intracavity intensity and can occur for very weak laser driving amplitudes

    Combination of Nigella sativa and honey in eradication of gastric helicobacter pylori infection

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    Background: Gastric Helicobacter pylori is extremely common worldwide. Objectives: The aim of this study was to assess the effectiveness of combination of Nigella sativa and honey (Dosin) in eradication of gastric H. pylori infection. Patients and Methods: Nineteen patients who had positive result for H. pylori infection by urea breath test (UBT) without a past history of peptic ulcer, gastric cancer or gastrointestinal bleeding, were suggested to receive one teaspoon of the mixture of Dosin (6 g/day of N. sativa as ground seeds and 12 g/day of honey) three times a day after meals for two weeks. The second UBT was used to detect the presence of H. pylori four weeks after completion of the test. In addition, symptoms of dyspepsia were scored before and after the study and analyzed with Wilcoxon signed-rank test Results: Fourteen patients completed the study. Negative UBT was observed in 57.1 (8/14) of participants after intervention. The median and interquartile range (IQR) of total dyspepsia symptoms was significantly reduced from 5.5 (5 -12) to 1 (0 -4) (P = 0.005). All the patients tolerated Dosin except for one who was excluded due to mild diarrhea. No serious adverse events were reported. Conclusions: Dosin was concluded to be an anti H. pylori and an anti-dyspeptic agent. Further studies are recommended to investigate the effect of Dosin plus antibiotics (concurrently or following another) on gastric H. pylori infection. � 2016, Iranian Red Crescent Medical Journal

    Additive manufacturing of bioactive glass biomaterials

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    Tissue engineering (TE) and regenerative medicine have held great promises for the repair and regeneration of damaged tissues and organs. Additive manufacturing has recently appeared as a versatile technology in TE strategies that enables the production of objects through layered printing. By applying 3D printing and bioprinting, it is now possible to make tissue-engineered constructs according to desired thickness, shape, and size that resemble the native structure of lost tissues. Up to now, several organic and inorganic materials were used as raw materials for 3D printing; bioactive glasses (BGs) are among the most hopeful substances regarding their excellent properties (e.g., bioactivity and biocompatibility). In addition, the reported studies have confirmed that BG-reinforced constructs can improve osteogenic, angiogenic, and antibacterial activities. This review aims to provide an up-to-date report on the development of BG-containing raw biomaterials that are currently being employed for the fabrication of 3D printed scaffolds used in tissue regeneration applications with a focus on their advantages and remaining challenges

    ∼3-nm ZnO nanoislands deposition and application in charge trapping memory grown by single ALD step

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    Low-dimensional semiconductor nanostructures are of great interest in high performance electronic and photonic devices. ZnO is considered to be a multifunctional material due to its unique properties with potential in various applications. In this work, 3-nm ZnO nanoislands are deposited by Atomic Layer Deposition (ALD) and the electronic properties are characterized by UV-Vis-NIR Spectrophotometer and X-ray Photoelectron Spectroscopy. The results show that the nanostructures show quantum confinement effects in 1D. Moreover, Metal-Oxide-Semiconductor Capacitor (MOSCAP) charge trapping memory devices with ZnO nanoislands charge storage layer are fabricated by a single ALD step and their performances are analyzed. The devices showed a large memory window at low operating voltages with excellent retention and endurance characteristics due to the additional oxygen vacancies in the nanoislands and the deep barrier for the trapped holes due to the reduction in ZnO electron affinity. The results show that the ZnO nanoislands are promising in future low power memory applications. © The Author(s) 2016

    The effects of myrtle (myrtus communis) and clindamycin topical solution in the treatment of mild to moderate acne vulgaris: A comparative split-face study

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    Objectives: Although Acne vulgaris is a chronic skin disease, which its standard treatment causes therapeutic limitations and some common adverse effects, medicinal plants can be effective in treatment with low adverse effects as combination therapy. Myrtle (Myrtus Communis) has some beneficial properties, which has been administered topically and orally for some skin diseases in Persian medicine. This study aimed to compare the efficacy and safety of Myrtle formula and 1 clindamycin topical solution. Methods: This was a split-face clinical trial that was done on 55 patients with mild to moderate acne vulgaris for 16 weeks. The patients received topical Myrtle solution to the right side of the face (group 1) and clindamycin solution to the left side (group 2) twice daily for 12 weeks. All participants were examined for the acne severity index (ASI) and total acne lesions counting (TLC) at certain times during the study. Then, they stopped using them for four weeks. They also did not take the drug in the final four weeks of the study. Results: Forty-eight patients completed the study for 16 weeks; 40 (83.2) patients were female and the rest of them were male. The mean age and standard deviation were 25.62 ± 7.62 years. After 12 weeks, the percentage changes of comedones, inflammatory lesions, ASI and TLC were significantly reduced in both groups (p < 0.001). The percentage change of inflammatory lesions and ASI decrease was significantly higher in the group 1 (p = 0.03). There was no significant difference in the incidence of side effects between the two groups. There was a more significant decrease in sebum percentage change in the group 1 (p = 0.003). Conclusion: Myrtle lotion was effective and safe for the treatment of mild to moderate acne vulgaris. Copyright © Korean Pharmacopuncture Institut
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