Micromorphic Electromagnetic Theory and Waves

This paper introduces a continuum microelectromagnetic theory (also called micromorphic electromagnetic theory), to discuss electromagnetic phenomena in bodies with microstructures. Balance laws of microelectromagnetic media of the first-grade are given. Constitutive equations are developed. The field equations are obtained . It has been shown that, this theory gives rise to several new vector and tensor waves. A theorem of conservation of energy (Poynting type) is proved. Dispersion relations are obtained for both vector and tensor waves. Relations of tensor waves to microscopic phenomena (such as spin waves) are discussed.     

Triethylamin-mediated addition of 2-aminoethanethiol hydrochloride to chalcones: Synthesis of 3-(2-aminoethylthio)-1-(aryl)-3-(thiophen-2-yl) propan-1-ones and 5,7-diaryl-2,3,6, 7-tetrahydro-1,4-thiazepines

The triethylamin-mediated addition of 2-aminoethanethiol hydrochloride to chalcone analogs was investigated. This addition, bearing a 2-thienyl group at the 3-position, gave the only addition adduct at room temperature in 3 h, whereas the chalcones bearing the 2-furyl group at the 1-position gave an addition-cyclization product (1, 4-thiazepine) in the same conditions. The effect of the groups to the reaction was investigated by changing the 1- and 3-position groups. The chalcones bearing the 2-thienyl group at the 1-position and the others afforded the mixture of products in different ratio at rt for 0.5–24 h. Moreover, the addition–cyclization products (1,4-thiazepine) were obtained under reflux conditions in 36 h. The structures of the synthesized compounds were elucidated by ¹H NMR, ¹³C NMR, infrared, and elemental analysis.     

Polymer-Enhanced Ultrafiltration of Fe(III) and Cu(II) Aqueous Solutions Using Poly(Vinyl Alcohol)-Alginic Acid/Cellulose Membranes

This study deals with the removal of Fe(III) and Cu(II) from dilute aqueous solutions using a polymer-enhanced ultrafiltration process. The ultrafiltration studies were carried out in batch stirred cell and the applied pressure was controlled by nitrogen gas. Properties of the composite membranes and its application in metal removal from aqueous solutions were studied. A composite poly(vinyl alcohol)-alginic acid/cellulose membranes were prepared by coating poly(vinyl alcohol)-alginic acid mixture solutions on the filter paper. Poly(vinyl alcohol) and alginic acid were also used as complexing agents to enhance the retention of metal ions. In the filtration of Fe(III) and Cu(II) solutions, the effects of membrane contents, pressure and pH on the retention and the flux were studied. The maximum retention of metals was found as 99% for Fe(III) solution at pressure of 45 psi, pH of 3 in the presence of poly(vinyl alcohol) as complexing agent by using 0.50 (w/v)% [(75 Poly(vinyl alcohol)/25 Alginic acid) (w/w)]/cellulose composite membranes.     

Stress concentration at the tip of crack

By means of the theory of nonlocal elasticity, the stress concentration is determined at the tip of crack subjected to a uniform tension perpendicular to the line of crack at infinity. The stress concentration is found to be finite and depends on the length of the crack.     

Theory of micropolar plates

Zusammenfassung Auf der Basis der linearen Theorie der mikropolaren Elastizität wird eine Theorie für Dehnung und Biegung mikropolarer Platten entwickelt. Die Platten werden aus Hantel-Elementen zusammengesetzt angenommen. Die Theorie berücksichtigt Drehungs- und Schiebungseffekte sowohl klassischen wie auch mikropolaren Ursprungs. Es entstehen symmetrische und antimetrische Spannungsverteilungen als Bestandteile einer ungekoppelten Feldtheorie. Es werden Sätze bezüglich der inneren Energie und der Eindeutiekeit der Lösung aufgestellt. Einige Näherungstheorien sowie die Natur mikropolarer Biegewellen in unendlichen Platten werden diskutiert.     

Deformation in cooperative molecular motors

We implement a model to represent the effect of the deformation of the backbone of a system of motor proteins while sliding on a track filament. This model incorporates a nearest neighbor interaction term among the motors for the deformation energy. Correlations induced by this term result in increased motor force for inter-particle distances small compared to the ratchet period. Received 20 February 2001 and Received in final form 31 May 2001     

Crystal Data,Electrical Resisitivity and Mobility in Cu3In5Se9 and Cu3In5Te9 Single Crystals

X-ray powder diffraction data were obtained for Cu₃In₅Se₉ and Cu₃Te₉, which were found to crystallize in orthorhombic and tetragonal systems, respectively. The electrical resistivities and Hall mobilities of these compounds were investigated in the temperature range 35–475 K. Cu₃In₅Se₉, was identified to be n-type with a room temperature resistivity of 3 × 10³ Ω·cm which decreases with increasing temperature. For T < 65 K impurity activation energy of 0.03 eV and for T > 350 K onset of intrinsic conduction yielding a band gap energy of 0.99eV were detected. The neutral impurity scattering was found to dominate at low temperatures, while in the high temperature region thermally activated mobility was observed. Cu₃In₅Te₉ exhibits p-type conduction with a room temperature resistivity of 8.5 × 10⁻³ Ω·cm decreasing sharply above 400 K and yielding an impurity ionization energy of 0.13 eV. The temperature dependence of mobility indicates the presence of lattice and ionized impuritiy scattering mechanisms above and below 160 K, respectively.