this paper investigates the radiative absorptivity of a spherical cavity by using monte carlo techniques. several parameters such as the angle of incoming radiation which inters the cavity for both diffuse wall cavity and specular wall cavity has been  investigated. the absorptivity of a spherical cavity has been calculated and compared with the exact values when the angle of incoming radiation...

‎In this work‎, ‎a regular polygon with $n$ sides is described by a periodic (circular) sequence with period $n$‎. ‎Each element of the sequence represents a vertex of the polygon‎. ‎Each symmetry of the polygon is the rotation of the polygon around the center-point and/or flipping around a symmetry axis‎. ‎Here each symmetry is considered as a system that takes an input circular sequence and g...

in this work, the optimization calculations were carried out on quetiapine hemifumarat, 4, and its analogues, 1-5. these calculations were carried out using the b3lyp/6-31g(d) level of theory. the dft calculations clarified a boat structure for dibenzothiazepine moiety of the molecule which piperazine moiety has a chair conformation. thermal energies (e), enthalpies (h), and free energies (g) o...

in this work the performance of a wavelength division multiple access (wdma) system with direct detection receiver is investigated. for this purpose, the probability of error in a wdma network with ook modulation considering crosstalk, isi, photo detector noise and thermal noise is calculated and the effect of each on system performance is investigated. the system performance in presence of pin...

in this paper, the structure of a new 16-membered macrocyclic schiff base compound n,n′-(3,3′-dimethoxy-2,2′-(propane-1,3-diyldioxy)dibenzylidene)propane-1,3-diamine, c22h26n2o4 (1), derived from 1,3-propanediamine and 3,3′-dimethoxy-2,2′-(propane-1,3-diyldioxy)dibenzaldehyde has been studied by single crystal x-ray diffraction, dft calculations at b3lyp/6-31g** and ft-ir spectroscopy. the titl...

ab initio calculations at hf/6-31g* level of theory for geometry optimization and mp2/6-31g*//hf/6-31g* for a single point total energy calculation are reported for the importantenergy-minimum conformations and transition-state geometries of 1, 3-diazacyclohepta-1, 2-diene (2) and 1, 3-diazacycloocta-1, 2-diene (3). the c2 symmetric twist-chair (2-tc)conformation of 2 is calculated to be 7.4 kj...