Copulas are very efficient functions in the field of statistics and specially in statistical inference. They are fundamental tools in the study of dependence structures and deriving their properties. These reasons motivated us to examine and show  various types of copula functions and their families. Also, we separately explain each method that is used to construct each copula in detail with different examples. There are various outcomes that show the copulas and their densities with respect to the joint distribution functions. The aim is to make copulas available to new researchers and readers who are interested in the modern phenomenon of statistical inferences.

  A new hetrocyclic liquid crystal compounds containing 1,3,4-oxadiazole with different substituted in para position (Bromo, Chloro, Nitro and Methyl) were synthesized and characterized by melting points, FTIR Spectroscopy and 1HNMR spectroscopy for [Cl-SR6] and [NO2-SR6] compounds. The liquid crystalline properties of the synthesized compounds were studied by using hot-stage polarizing optical microscopy (POM), so they determined the transition enthalpies and entropies by using differential scanning calorimetery (DSC). All of the compounds show mesomorphic properties. The compounds [Br-SR6], [Cl-SR6] and [NO2SR6] exhibit an enantiotropic dimorphism smectic (Sm) phase, while the compounds [MeSR6] showed nematic (N) phase throw cooli

    A new hetrocyclic liquid crystal compounds containing 1,3,4-oxadiazole with different substituted in para position (Bromo, Chloro, Nitro and Methyl) were synthesized and characterized by melting points, FTIR Spectroscopy and 1HNMR spectroscopy for [Cl-SR6] and [NO2-SR6] compounds. The liquid crystalline properties of the synthesized compounds were studied by using hot-stage polarizing optical microscopy (POM), so they determined the transition enthalpies and entropies by using differential scanning calorimetery (DSC). All of the compounds show mesomorphic properties. The compounds [Br-SR6], [Cl-SR6] and [NO2SR6] exhibit an enantiotropic dimorphism smectic (Sm) phase, while the compounds [MeSR6] showed nematic (N) phase thro

Abstract: When it comes to applications in welding, cutting, and surface engineering, the utilization of high-power fiber-delivered beams from solid-state lasers offers several benefits. This paper addresses the issue of cleaning the surface of the samples with different spot sizes (50, 100 and 200) (industrial ytterbium fiber laser) to prepared it to be welded. Angular laser cleaning with incident angles (5, 10, 15, 20, 25, 30) ° with different powers (3, 5, 7, 10) W and hatch distance 0.001 was use for implemented.

     The longitudinal electron scattering form factors and the electric quadrupole moments are calculated for the states with J^π T= 3⁺0 (ground state) and 1⁺ 0 (583keV excited state) of ²²Na and J^π T= 3⁺2 (ground state) of ²⁶Na. Shell model calculations are based on USDA, USDB and Wildenthal interactions. The exact center of mass correction is included in Born approximation picture to generate the longitudinal form factors. The core polarization (CP) effect with the values of effective nucleon charges e_p=1.35, e_n= 0.35, with Bohr Mottelson formula gave a good agreement with the measured electric quadrupole moments. The structure of th

Iraq is facing water shortage problems due to various factors, globally ( Global warming) and regionally ( GAP project) and locally ( improper water resources management projects). In this search the global warming influence on the annual mean value of temperature and yet on the annual mean value of the evapotranspiration for more than three decades has been studied. The climate of Iraq is influenced by its location between the subtropical aridity of the Arabian desert areas and the subtropical humidity of the Arabian Gulf. The relative ascension of temperature degrees in the recent decades was the main factor in relative humidity decrement which increase the evapotranspiration values, since that utilizing a temperature-based method as i

plaque forming assay was used enumerate the number of plaque forming cells of anti-HBc in eight patintes with chronic hepatitis and eight health