2,717 research outputs found

    Using of Chroococcus SP. to Treat Polluted Water with Cadmium & Nickel

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    Chroococcus sp. was exposed to different concentrations 0.3, 0.5, 1, 2, 3, 4, 5, 6 and 7 ppm, from cadmium and nickel. The results revealed that the ability of the alga to remove cadmium and nickel was increased with the increase of the metal concentration which the alga exposed to them and this case does not record before. This may relate to mechanisms of adsorption and removal which not understood perfectly till now according to many researches that concerned with this field of studies. It was noticed that the removal percentage of cadmium reaches to 77.66 & 76% in the two higher concentrations 6 & 7 ppm, which exposed to the alga till the last day (twelve days) from the experiment, but same percentage (77.66 & 76%) was recorded on the eighth day of the experiment to remove nickel and decrease to 12.5 & 28% on the last day of the experiment for the above two concentrations

    A review on femoropopliteal arterial deformation during daily lives and nickel-titanium stent properties

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    The increasing number of studies on the behaviour of stent placement in recent decades provides a clear understanding of peripheral artery disease (PAD). The severe mechanical loads (axial ten�sion and compression, bending, radial compression and torsion) deformation of the femoropopli�teal artery (FPA) is responsible for the highest failure rate of permanent nickel-titanium (Nitinol) stents. Therefore, the purpose of this article is to review research papers that examined the deformation of the natural load environment of FPA, the properties of Nitinol and mechanical considerations. In conclusion, a better understanding of mechanical behaviour for FPA Nitinol stents contributes to increased mechanical performance and fatigue-life

    The Bivariate Rogers-Szeg\"{o} Polynomials

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    We present an operator approach to deriving Mehler's formula and the Rogers formula for the bivariate Rogers-Szeg\"{o} polynomials hn(x,yq)h_n(x,y|q). The proof of Mehler's formula can be considered as a new approach to the nonsymmetric Poisson kernel formula for the continuous big qq-Hermite polynomials Hn(x;aq)H_n(x;a|q) due to Askey, Rahman and Suslov. Mehler's formula for hn(x,yq)h_n(x,y|q) involves a 3ϕ2{}_3\phi_2 sum and the Rogers formula involves a 2ϕ1{}_2\phi_1 sum. The proofs of these results are based on parameter augmentation with respect to the qq-exponential operator and the homogeneous qq-shift operator in two variables. By extending recent results on the Rogers-Szeg\"{o} polynomials hn(xq)h_n(x|q) due to Hou, Lascoux and Mu, we obtain another Rogers-type formula for hn(x,yq)h_n(x,y|q). Finally, we give a change of base formula for Hn(x;aq)H_n(x;a|q) which can be used to evaluate some integrals by using the Askey-Wilson integral.Comment: 16 pages, revised version, to appear in J. Phys. A: Math. Theo

    Wideband millimeter-wave substrate integrated waveguide cavity-backed antenna for satellites communications

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    This paper presents a new type of wideband waveguide (SIW) cavity-backed patch antenna for millimeter wave (mmW). The antenna proposed applies to applications of 31-36 GHz Ka-band such as satellites communications. The SIW is intended with settings for particular slots. The antenna is constructed on Rogers RT5880 (lossy) with 2.2 dielectric constant, l.27 mm thickness, and 0.0009 loss tangent. It is simulated in the programming of computer simulation technology (CST) Microwave Studio. The simulated results show that the SIW antenna resonates across 31 to 36 GHz bands, which means that this new antenna covers all applications within this range. The reflection coefficients in targeting range are below 10 dB. The antenna achieves good efficiency and gain with 80% and 8.87 dBi respectively

    The Polar form of a Neutrosophic Complex Number

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    In this paper, we will define the exponential form of a neutrosophic complex number. We have proven some characteristics and theories, including the conjugate of the exponential form of a neutrosophic complex number, division of the exponential form of a neutrosophic complex numbers, multiplication of the exponential form of a neutrosophic complex numbers. In addition, we have given the method of changing from the exponential to the algebraic form of a complex number

    Is there a role for melatonin in fibromyalgia?

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    Fibromyalgia, characterised by persistent pain, fatigue, sleep disturbance and cognitive dysfunction, is a central sensitivity syndrome that also involves abnormality in peripheral generators and in the hypothalamic pituitary adrenal axis. Heterogeneity of clinical expression of fibromyalgia with a multifactorial aetiology has made the development of effective therapeutic strategies challenging. Physiological properties of the neurohormone melatonin appear related to the symptom profile exhibited by patients with fibromyalgia and thus disturbance of it’s production would be compatible with the pathophysiology. Altered levels of melatonin have been observed in patients with fibromyalgia which are associated with lower secretion during dark hours and higher secretion during daytime. However, inconsistencies of available clinical evidence limit conclusion of a relationship between levels of melatonin and symptom profiles in patients with fibromyalgia. Administration of melatonin to patients with fibromyalgia has demonstrated suppression of many symptoms and an improved quality of life consistent with benefit as a therapy for the management of this condition. Further studies with larger samples, however, are required to explore the potential role of melatonin in the pathophysiology of fibromyalgia and determine the optimal dosing regimen of melatonin for the management of fibromyalgia

    The impact of Stieltjes' work on continued fractions and orthogonal polynomials

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    Stieltjes' work on continued fractions and the orthogonal polynomials related to continued fraction expansions is summarized and an attempt is made to describe the influence of Stieltjes' ideas and work in research done after his death, with an emphasis on the theory of orthogonal polynomials

    Fuzzy Logic Based Self-Adaptive Handover Algorithm for MobileWiMAX.

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    It is well known that WiMAX is a broadband technology that is capable of delivering triple play (voice, data, and video) services. However, mobility in WiMAX system is still a main issue when the mobile station (MS) moves across the base station (BS) coverage and be handed over between BSs. Among the challenging issues in mobile WiMAX handover are unnecessary handover, handover failure and handover delay, which may affect real-time applications. The conventional handover decision algorithm in mobile WiMAX is based on a single criterion, which usually uses the received signal strength indicator (RSSI) as an indicator, with the other fixed handover parameters such as handover threshold and handover margin. In this paper, a fuzzy logic based self-adaptive handover (FuzSAHO) algorithm is introduced. The proposed algorithm is derived from the self-adaptive handover parameters to overcome the mobile WiMAX ping-pong handover and handover delay issues. Hence, the proposed FuzSAHO is initiated to check whether a handover is necessary or not which depends on its fuzzy logic stage. The proposed FuzSAHO algorithm will first self-adapt the handover parameters based on a set of multiple criteria, which includes the RSSI and MS velocity. Then the handover decision will be executed according to the handover parameter values. Simulation results show that the proposed FuzSAHO algorithm reduces the number of ping-pong handover and its delay. When compared with RSSI based handover algorithm and mobility improved handover (MIHO) algorithm, respectively, FuzSAHO reduces the number of handovers by 12.5 and 7.5 %, respectively, when the MS velocity is <17 m/s. In term of handover delay, the proposed FuzSAHO algorithm shows an improvement of 27.8 and 8 % as compared to both conventional and MIHO algorithms, respectively. Thus, the proposed multi-criteria with fuzzy logic based self-adaptive handover algorithm called FuzSAHO, outperforms both conventional and MIHO handover algorithms

    New approaches to measuring anthelminthic drug efficacy: parasitological responses of childhood schistosome infections to treatment with praziquantel

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    By 2020, the global health community aims to control and eliminate human helminthiases, including schistosomiasis in selected African countries, principally by preventive chemotherapy (PCT) through mass drug administration (MDA) of anthelminthics. Quantitative monitoring of anthelminthic responses is crucial for promptly detecting changes in efficacy, potentially indicative of emerging drug resistance. Statistical models offer a powerful means to delineate and compare efficacy among individuals, among groups of individuals and among populations.; We illustrate a variety of statistical frameworks that offer different levels of inference by analysing data from nine previous studies on egg counts collected from African children before and after administration of praziquantel.; We quantify responses to praziquantel as egg reduction rates (ERRs), using different frameworks to estimate ERRs among population strata, as average responses, and within strata, as individual responses. We compare our model-based average ERRs to corresponding model-free estimates, using as reference the World Health Organization (WHO) 90 % threshold of optimal efficacy. We estimate distributions of individual responses and summarize the variation among these responses as the fraction of ERRs falling below the WHO threshold.; Generic models for evaluating responses to anthelminthics deepen our understanding of variation among populations, sub-populations and individuals. We discuss the future application of statistical modelling approaches for monitoring and evaluation of PCT programmes targeting human helminthiases in the context of the WHO 2020 control and elimination goals

    Effect of Partial Replacements of Coarse Aggregate by Polycarbonate Plastic Waste on the First Crack Impact Resistance of Concrete Beam

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    This paper examines impact strength properties of concrete in which different amounts 2.5%, 5% and 10% of polycarbonate plastic waste particles were used as coarse aggregate replacement. For each amount, six beams of 100 mm ×100 mm × 500mm were subjected to 4.5 kg hammer from 457 mm height. The number of blows of the hammer required to induce the first visible crack of the beams were recorded. The results are presented in terms of impact energy required for the first visible crack. The concrete mixtures exhibited ability to absorb a large amount of impact energy. The polycarbonate plastic waste increased the first crack impact energy of concrete. Keywords: Polycarbonate plastic waste; Cement concrete; Compressive strength; First crack impact energy. DOI: 10.7176/JEES/10-2-06 Publication date: February 29th 202
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