Pravilni poligoni u taxicab ravnini

In this paper, we define taxicab regular polygons and determine which Euclidean regular polygons are also taxicab regular, and which are not. Finally, we investigate the existence or nonexistence of taxicab regular polygons.U radu definiramo pravilne taxicab poligone i određujemo koji su pravilni euklidski poligoni ujedno i pravilni taxicab poligoni, a koji nisu. Naposljetku, ispitujemo postojanje ili nepostojanje pravilnih taxicab poligona

Pravilni poligoni u taxicab ravnini

In this paper, we define taxicab regular polygons and determine which Euclidean regular polygons are also taxicab regular, and which are not. Finally, we investigate the existence or nonexistence of taxicab regular polygons.U radu definiramo pravilne taxicab poligone i određujemo koji su pravilni euklidski poligoni ujedno i pravilni taxicab poligoni, a koji nisu. Naposljetku, ispitujemo postojanje ili nepostojanje pravilnih taxicab poligona

Enhanced thermoelectric performance via the solid solution formation: The case of pseudobinary alloy (Cu2Te)(Ga2Te3)3 upon Sb substitution for Cu

In this work we have observed the beneficial effect from the solid solution formation on the thermoelectric performance of (Cu2(1 − x)Sb2xTe)(Ga2Te3)3 upon Sb substitution for Cu. This substitution allows the different occupations of Sb in the crystal lattice, i.e. Sb at Cu sites with x ≤ 0.05 and at Ga sides with x ≥ 0.05, which has resulted in the Pisarenko relation does not exactly capture the measured Seebeck coefficient under assumed effective masses m*. The reduction of the lattice thermal conductivity (κL) has been quantified within the temperature range from room temperature to 723 K. Over the entire composition range, the κL value is reduced by 33% and 25% at temperature 723 K and 580 K, respectively. This observation is in a good agreement with the theoretical calculation based on the Callaway model used in the solid solutions. Along with the increasing of the mobility and electrical conductivity, the thermoelectric performance has been improved with the highest ZT value of 0.58 at 723 K, which is about double the value of intrinsic (Cu2Te)(Ga2Te3)3

Commencement of normal menstrual cycles after 17 years in a patient with Sheehan's syndrome.

We solve problems 85 a(nd 87 from Birkhoff's book "Lattice Theory" (3rdedition

Effect of clonazepam on Raynaud's phenomenon and fingertip ulcers in scleroderma.

OBJECTIVE: To report the novel finding of a significant improvement in Raynaud's phenomenon symptoms with clonazepam in a patient with systemic sclerosis. CASE SUMMARY: A 45-year-old female with limited scleroderma and chronic renal failure was admitted to our hospital due to hyponatremia (sodium 103 mEq/L). Her hyponatremia was treated by intravenous infusion of NaCl 3%. Clonazepam, which had been prescribed previously for anxiety and insomnia, was discontinued. Three weeks after she was discharged from the hospital, the patient presented with the complaint of increased severity of Raynaud's phenomenon and digital ulcers. She told us that her fingertip ulcers had been healed while she was taking clonazepam and that episodes of Raynaud's phenomenon had increased after discontinuation of the drug. Clonazepam 1 mg twice daily was restarted, and Raynaud's phenomenon and fingertip ulcers resolved within a month. On 2 occasions after that time, we discontinued clonazepam and replaced it with alprazolam, as the patient believed alprazolam was more beneficial in alleviating anxiety. Episodes of Raynaud's phenomenon and new digital ulcers recurred on both of these occasions, and clonazepam was restarted. At the time of writing, no severe episodes of Raynaud's phenomenon or fingertip ulcers have occurred with clonazepam treatment. DISCUSSION: Raynaud's phenomenon and recurrent digital ulcers are a manifestation of vascular disease in patients with systemic sclerosis and lead to pain, impaired function, and tissue loss. Few drugs have previously been shown to affect digital ulcers in the setting of scleroderma. Our patient experienced a significant and sustained improvement in Raynaud's phenomenon and digital ulcers following the initiation of clonazepam. To our knowledge, as of March 2007, this is the first reported use of clonazepam in Raynaud's phenomenon and digital ulcer. While its therapeutic mechanism remains unclear, clonazepam may offer some advantages compared with current agents. CONCLUSIONS: We report a case of Raynaud's phenomenon and digital ulcers responding to clonazepam. Further research is warranted to test the robustness of this preliminary finding

Ab initio study of structural, elastic and vibrational properties of praseodymium chalcogenides

WOS: 000290650200002The plane-wave pseudopotential approach to the density-functional theory within the GGA approximation implemented in Vienna Ab-initio Simulation Package (VASP) code have been used to calculate structural, elastic and lattice dynamical properties of praseodymium chalcogenides: PrS, PrSe and PrTe. The structural properties are performed in five different crystal structures: NaCl (space group Fm3m(225)), CsCl (space group Pm3m(221)), ZB (space group F43m(216)), WC (space group P6m2(187)) and CuAu (P4/mmm(123)). Our results showed that these chalcogenides are stable in NaCl phase which are in agreement with the experimental works. The phonon dispersion curves are showed that the gap between the optic and acoustic branches decreases on going from PrS to PrTe. We have also estimated some thermodynamical properties such as entropy and heat capacity at the temperature range 0-1000 K. (C) 2011 Elsevier B.V. All rights reserved