311 research outputs found

    Laboratory Validation of Calculations of Magnetic Field Mitigation Underneath Transmission Lines Using Passive and Active Shield Wires

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    This paper is aimed at reporting experimental measurements and calculations of how the magnetic field underneath overhead transmission lines is mitigated using passive and active shield wires. The magnetic field values were compared to those calculated using the current simulation technique (CST). A laboratory transmission line model representing the Egyptian 500 kV EHV line was built with dimensions scaled down in the ratio 10:1. The flat single circuit of the line was modeled in the laboratory by phase separation of 1.2 m and conductor diameter of 2.76 mm at height of 1.9 m. The shield wires were spaced 4.3 m at a height of 1.45 m. Magnetic field measurements were carried out for load currents of 5.7 and 10 A. The field was measured at 0.3 m above ground level with and without passive and active shield wires for several different lateral positions. The measured and calculated field values generally agreed reasonably with an error ranging between 2.5 and 20 % within the ROW. The maximum reduction of magnetic field from the passive shield wires is 10% at the edge of right of way. With active shield wires carrying a current of 5 A (one half of the conductor current), the reduction of magnetic field reached 17% at the edge of ROW

    Pentaquark searches at FOCUS

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    We find no evidence for high-energy photoproduction of pentaquarks at 1540 MeV/c2c^2, 1862 MeV/c2c^2, or 3099 MeV/c2c^2 using decay modes pKS0pK_S^0, Ξ−π−\Xi^-\pi^-, and D(∗)−pD^{(*)-}p, respectively.Comment: Proceedings from talk at 2004 DPF Meeting at University of California, Riversid

    On the SigmaN cusp in the pp -> pK+Lambda reaction

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    Measurements of the pp→pK+Λpp \to pK^+\Lambda reaction at TpT_p = 2.28 GeV have been carried out at COSY-TOF. In addition to the Λp\Lambda p FSI and N∗N^* resonance excitation effects a pronounced narrow structure is observed in the Dalitz plot and in its projection on the pΛp\Lambda-invariant mass. The structure appears at the pp→pp \to NK+ΣK^+\Sigma threshold and is interpreted as Σ\SigmaN cusp effect. The observed width of 20 MeV/c2c^2 is substantially broader than anticipated from previous inclusive measurements. Angular distributions of this cusp structure are shown to be dissimilar to those in the residual pK+ΛpK^+\Lambda channel, but similar to those observed in the pK+Σ0pK^+\Sigma^0 channel

    Effect of binary and ternary solid dispersions prepared by fusion method on the dissolution of poorly water soluble diacerein

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    The poor solubility of drug substances in water and their low dissolution rate in aqueous G.I.T fluid often leads to insufficient bioavailability. The present investigation is an attempt to improve the solubility and dissolution rate of diacerein (a poorly soluble drug) by solid dispersion technique. Binary solid dispersions were made using PEG-4000 or PEG-6000 as carriers with varying drug: carrier ratios 1:1, 1:3 and 1:5. Also ternary solid dispersions were made using PEG-4000 and Pluronic F-68 at ratios 1:5:1, 1:5:2 and 1:5:3. Nine formulae were prepared and evaluated for saturated solubility, In-vitro drug release. Solid state characterization including DSC, FTIR, XRD and SEM is also carried out. All formulae showed marked significant improvement in the solubility and dissolution rate of the drug. The interaction studies showed no interaction between the drug and any of the used carriers. Formula SD9 (1:5:3; drug: PEG-4000: Pluronic F-68) showed the best dissolution profile with about 44.73% of the drug being released in the first 5 minutes and more than 79 % of the drug being released in the first 15 minutes. Also this formula showed the highest dissolution rate of 6.66 %/min. It was concluded that combination of PEG-4000 and Pluronic F-68 can be well utilized to improve the solubility of poorly soluble drugs

    Effect of binary and ternary solid dispersions prepared by fusion method on the dissolution of poorly water soluble diacerein

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    The poor solubility of drug substances in water and their low dissolution rate in aqueous G.I.T fluid often leads to insufficient bioavailability. The present investigation is an attempt to improve the solubility and dissolution rate of diacerein (a poorly soluble drug) by solid dispersion technique. Binary solid dispersions were made using PEG-4000 or PEG-6000 as carriers with varying drug: carrier ratios 1:1, 1:3 and 1:5. Also ternary solid dispersions were made using PEG-4000 and Pluronic F-68 at ratios 1:5:1, 1:5:2 and 1:5:3. Nine formulae were prepared and evaluated for saturated solubility, In-vitro drug release. Solid state characterization including DSC, FTIR, XRD and SEM is also carried out. All formulae showed marked significant improvement in the solubility and dissolution rate of the drug. The interaction studies showed no interaction between the drug and any of the used carriers. Formula SD9 (1:5:3; drug: PEG-4000: Pluronic F-68) showed the best dissolution profile with about 44.73% of the drug being released in the first 5 minutes and more than 79 % of the drug being released in the first 15 minutes. Also this formula showed the highest dissolution rate of 6.66 %/min. It was concluded that combination of PEG-4000 and Pluronic F-68 can be well utilized to improve the solubility of poorly soluble drugs

    Salivary PCR detection of Helicobacter pylori DNA in Egyptian patients with dyspepsia

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    Several methods are available for detecting Helicobacter pylori infection: (1) invasive methods based on gastric biopsies, (2) non invasive methods like Urea Breath Test (UBT), serology and stool antigen tests. Importance of salivary PCR in detection of H. pylori is still questionable. To evaluate the role of salivary PCR technique in detecting H. pylori gastric affection in Egyptian patients with dyspepsia and in differentiating between functional dyspepsia and acid-ulcer syndrome. This study included 60 patients with dyspepsia classified into three groups: (Group 1) patients with gastric H. pylori and ulcers or erosions (n= 20), (Group 2) patients with gastric H. pylori and no ulcers or erosions and had functional dyspepsia (n= 20), (Group 3) patients without H. pylori and had functional dyspepsia (n= 20). All underwent upper gastrointestinal endoscopy with biopsies, rapid urease test and salivary samples for H. pylori PCR. Significant difference between the three groups regarding salivary PCR values. No significant difference between Group 1 and Group 2 but both had significant difference with Group 3, significant difference between gastric H. pylori positive patients (n= 40) and negative ones (n= 20). Salivary PCR test had sensitivity of 85%, specificity of 70% in diagnosing H. pylori. PCR value of 534000 Iu/ml had best sensitivity (75%) and specificity (100%) for diagnosing H. pylori, highly significant positive correlation between H. pylori gastric affection and salivary PCR values. No significant difference between patients with acid ulcer syndrome (n=20) and those with functional dyspepsia (n= 40) as regard salivary PCR mean values. Salivary PCR test showed sensitivity of 100%, specificity of 50% in differentiating between patients with acid ulcer syndrome and those with functional dyspepsia. PCR value of 440000 Iu/ml had best sensitivity (100%) and specificity (55%) in differentiating acid ulcer syndrome from functional dyspepsia with non significant. H. pylori salivary PCR may be of value in diagnosing H. pylori gastric affection and is strongly correlated with it but it is of limited value in differentiating between acid ulcer syndrome and functional dyspepsia.Keywords: Salivary PCR; Helicobacter pylori; Functional dyspepsia; Acid ulcer syndrom

    Pentaquarks in the Chiral Symmetry Limit

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    We demonstrate that a five quark state of positive parity with an internal P-wave structure - usually pictured as a composite of an antiquark and two diquarks in a P-wave state - can couple to nucleons and Goldstone particles in a chirally invariant way. The corresponding decay width is generally not suppressed. A pentaquark of positive or negative parity with an internal S-wave structure, which may be viewed as a composite of an antiquark and two chirally different diquarks in an S-state, does not couple to nucleons and light mesons in the limit of an unbroken chiral symmetry. It is stable in this limit. However, such states can decay via the effect of the spontaneous breaking of chiral symmetry. This breaking is strong because of the sizeable magnitude of the quark condensate. Thus, chiral symmetry cannot be the cause of a tiny decay amplitude, even for pentaquarks stable in a strict chiral symmetry limit.Comment: Modified version. We added a discussion of the effect of spontaneous breaking of chiral symmetry on the pentaquark. This has changed part of our conclusions: we argue that the effect is large indicating that chiral symmetry cannot be the origin of the small width of the pentaquar

    EFFECT OF SOME MAJOR ELEMENTS ON GROWTH PERFORMANCE AND BLOOD PARAMETERS IN FISH

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    he present experiment was conducted to determine the optimal source and level of phosphorus supplementation in commercial feeds with the highest growth rate and the lowest releasing in environmental and protect water quality of Nile Juveniles tilapia (Oreochromis niloticus). Fish were divided into twelve groups (groups) each group was stocked into two aquaria each contains 10 fish.  Fish were fed diet contained different levels of phosphorus (0.005, 0.007, 0.009 and 0.011%Kg diet phosphorus) from   three different sources of phosphorus (mono calcium phosphate, mono potassium phosphate and mono sodium phosphate) for a period of 12 weeks. Results showed that average daily gain, specific growth rate, protein efficiency ratio and feed conversation ratio were significantly improved at (p) 1.1% dietary phosphorus level with mono sodium phosphate as the source of phosphorus, mono calcium phosphate represented the highest significant (P<0.05) value of growth and blood parameters (Packed cell volume (PCV), Hemoglobein(Hb) ,red blood cell(RBC) and white blood cell(WBC) in Oreochromis niloticus .  Concerning levels of phosphorus the result clearly indicated that the 0.9% phosphorus level recorded the significant (P<0.05) highest growth and blood parameters in Oreochromis niloticus. Body composition analysis showed that the whole body protein and ash content were increased linearly but lipid was decreased (P<0.05) with increasing dietary of phosphorus

    The Experimental Search for Pentaquark

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    The existence of an anti-decuplet of pentaquark particles has been predicted some year ago within the chiral soliton model. In the last year, several experimental groups have reported evidence for a S=+1 baryon resonance, with mass ranging from 1.52 and 1.55 GeV and width less than 25 MeV, by looking at the invariant mass of the KNK N system. This resonance, has been identified with the lowest mass of the anti-decuplet, the Θ+\Theta^+. At the same time, there are a number of experiment, mostly at high energies, that report null results. An overview of the experimental results so far obtained will be given here together with a review of the second generation experiments currently ongoing and planned at Jefferson Lab Hall B.Comment: 10 pages, 9 figures, 3 tables Proceedings of the INCP2004 Conference - Goteborg (Sweden) June 27 - July 2, 200
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