In this paper a prey-predator-scavenger food web model is proposed and studied. It is assumed that the model considered the effect of harvesting and all the species are infected by some toxicants released by some other species. The stability analysis of all possible equilibrium points is discussed. The persistence conditions of the system are established. The occurrence of local bifurcation around the equilibrium points is investigated. Numerical simulation is used and the obtained solution curves are drawn to illustrate the results of the model. Finally, the nonexistence of periodic dynamics is discussed analytically as well as numerically.

In multivariate survival analysis, estimating the multivariate distribution functions and then measuring the association between survival times are of great interest. Copula functions, such as Archimedean Copulas, are commonly used to estimate the unknown bivariate distributions based on known marginal functions. In this paper the feasibility of using the idea of local dependence to identify the most efficient copula model, which is used to construct a bivariate Weibull distribution for bivariate Survival times, among some Archimedean copulas is explored. Furthermore, to evaluate the efficiency of the proposed procedure, a simulation study is implemented. It is shown that this approach is useful for practical situations and applicable fo

This research was conducted to determine content levels of heavy metal pollution. Samples taken from Ishaqi River bank and adjacent agricultural soils area, in ten sites, distributed along 48 km of the Ishaqi River, north Baghdad. The evaluated metals were Zinc, Copper, Manganese, Iron, Cobalt, Nickel, Chromium, Cadmium, Vanadium and Lead. PH and Electric Conductivity (EC) were measured to evaluate the acidity and (EC). Results showed that most site were contaminated with metals evaluated. Among these metals, Zn, Mn, Fe and Ni were consistently higher in all the samples (both river bank and adjacent soil) followed by PB, CU, V, Cd, Co and Cr. The level concentrations of river bank were almost higher than that of adjacent soil. As will be re

Background:The diabetogenic agent alloxan is a selective necrosis of insulin producing cells .Alloxan accumulated rapidly in liver and pancreatic islets , this study was carried out to evaluate the antidiabetic effect of cinnamon oil on the destructive effect of alloxan in liver and intestine diabetic tissues .
Materials and methods:Thirty male rats were used and divided into threegroups: Group I =10 animal controls, Group II =10 treated with alloxan, Group III = 10 treated with alloxan + cinnamon oil . 
Results:Liver and intestine tissues of diabetic groups revealed necrotic, degeneration of cells (histologically ) , increase in blood serum enzymes for acid and alkaline phosphatase , total protein&nbs

 In this paper we introduce several estimators for Binwidth of histogram estimators' .We use simulation technique to compare these estimators .In most cases, the results proved that the rule of thumb estimator is better than other estimators.

In this research, the TEC parameter has been determined for the ionosphere layer over the Iraqi zone. The calculations of this parameter have been conducted using the IRI model that considered as one of the recommended international models which used to calculate the ionosphere parameter (TEC). The determinations have been made for several sites or sites that located within the Iraqi territory. The years (2011-2013) of the solar cycle 24 have been adopted to make the determinations for the TEC parameter.The capital Baghdad has been selected to represent the transmitter station and many different communication points which are located in different directions around the transmitter station have been represented as receiving stations.

The coefficient of performance of a window type Air-Conditioner system can be improved if a reduction in the work of compressor can be achieved by a suitable technique. The present study investigates the effect of dispersing a low concentration of TiO2 nanoparticles in the mineral oil based lubricant, as well as on the overall performance of a window type Air-Conditioner system using R22 as the working fluid. An enhancement in the COP of the refrigeration system has been observed and the existence of an optimum volume fraction noticed, with low concentrations of nanoparticles suspended in the mineral oil. Results showed that the average compressor work reduced by 13.3%, which ultimately resulted in an increase of 11.99% in the COP due to

Within this paper, we developed a new series of organic chromophores based on triphenyleamine (TPA) (AL1, AL-2, AL-11 and AL-22) by engineering the structure of the electron donor (D) unit via replacing a phenyle ring or inserting thiophene as a π-linkage. For the sake of scrutinizing the impact of the TPA donating ability and the spacer upon the photovoltaic, absorptional, energetic, and geometrical characteristic of these sensitizers, density functional theory (DFT) and time-dependent DFT (TD-DFT) have been utilized. According to structural characteristics, incorporating the acceptor, π-bridge and TPA does not result in a perfect coplanar conformation in AL-22. We computed EHOMO, ELUMO and bandgap (Eg) energies by performing frequency a

Density Functional Theory (DFT) at the B3LYP/6-311G basis set level was performed on six new substituted Schiff base derivatives of PINH [(phenylallylidene) isonicotinohydrazide], The calculated quantum chemical parameters correlated to the inhibition efficiency are EHOMO (highest occupied molecular orbital energy), ELUMO (lowest unoccupied molecular orbital energy), the energy gap [ΔE(HOMO-LUMO)], hardness (η), softness (S), dipole moment (μ), electron affinity (EA), ionization potential (IE), the absolute electronegativity (χ), Global electrophilicity index ( ) and the fraction of electron transferred (ΔN), all have discussed at their equilibrium geometry and their correct symmetry (Cs). Comparisons of the order of inhibition effi