Samples of Oxytricha falax were collected from Tigris River by 55µ. mesh net. Culturing of O. falax were cultivated in specific conditions (DO 3-5mg/l.; W.Temp. 24±1ºC; pH: 6.8-7.5).The effect of various furfural concentration 0, 20, 40, 80,100 and 124 ppm and toluene concentration 0, 15, 30, 34.2, 34.5 and 35 ppm after two periods of treatment (24 and 48 hr.) on the physiological parameters of O. falax ciliate were observed. This study showed that the lethal concentration of furfural was 124ppm and 80ppm after 24hr. and 48hr. from treatment which killed all the individual community respectively. Furthermore the treatment of O. falax individuals with different concentrations of toluene indicated that 34.5 ppm of it caused disappearance of the individuals' population after 48hr., while the 35ppm concentration from toluene caused dead of all individuals after 24 hr. from their treatment.
CdS and CdTe thin films were thermally deposited onto glass substrate. The CdCl2 layer was deposited onto CdS surface. These followed by annealing for different duration times to modify the surface and interface of the junction. The diffraction patterns showed that the intensity of the peaks increased with the CdCl2/annealed treatment, and the grain sizes are increased after CdCl2/annealed treatment
The toxicity of insecticide dichlorvos (90%) was tested in ovaries of mosquito fish using three sublethal concentrations (0.3, 0.6, 0.8 µg/L) and studied their effects on the means of body and ovary weights, gonadosomatic index, ovum size and ova number. Results showed that there was a significant (P<0.05) decrease in body and ovary weights, ovum size and ova count. However, there was no significant (P<0.05) difference in gonadosomatic index in treated groups with the three concentrations of dichlorvos compared with the control group. This study was added evidence on the ovular toxicity of dichlorvos concerning its effect on fish production as well as reduction in the means of productive offspring and their survival.
Background: This in vitro study evaluated the effect of canal dryness and flaring on the accuracy of two electronic apex locators for working length (WL) determination. Materials and methods: Sixty extracted teeth were used, after access opening was done, the occlusal surface was flattened to create stable reference point. The teeth were randomly divided into two equal main groups of flared and unflared group each one of 30 teeth. The flaring was done with Gates Glidden drills. The two main groups were further subdivided into two subgroups: dry canal and wet canal using 5.25% sodium hypochlorite groups, Electronic WL of each sample was determined using both Root ZX and i-Root apex locator. Consequently, histologic WL was determined by shav
... Show MoreIn this paper the effect of thermal annealing on the structural and optical properties of Antimony Selenide (Sb2Se3) is investigated. Sb2Se3 powder is evaporated on clean amorphous glass substrates at room temperature under high vacuum pressure (4.5×10-6 mbar) to form thin films. The structural investigation was done with the aid of X-ray diffraction (XRD) and atomic force microscopy (AFM). The amorphous to polycrystalline transformation of these thin films was shown by X-ray diffraction analysis after thermal annealing. These films' morphology is explained. (UV-Vis ) spectra in ranges from 300 to 1100 nm was used to examine the optical properties of the films .The absorption coefficient and optical energy gap of the investigated films are
... Show MoreOne of the most important challenges facing the development of laser weapons is represented by the attenuation of the laser beam as it passed through the layers of atmosphere.This paper presents a theoretical study to simulate the effect of turbulence attenuation and calculates the decrease of laser power in Iraq. The refractive index structure C_n^2 is very important parameter to measure the strength of the atmospheric turbulence, which is affected by microclimate conditions, propagation path, season and time in the day. The results of measurements and predictions are based on the Kolmogorov turbulence theory. It was demonstrated by simulations that the laser weapons in Iraq were severely affected due to the large change in temperatures,
... Show MoreThis work consists of a numerical simulation to predict the velocity and temperature distributions, and an experimental work to visualize the air flow in a room model. The numerical work is based on non-isothermal, incompressible, three dimensional, k turbulence model, and solved using a computational fluid dynamic (CFD) approach, involving finite volume technique to solve continuity, momentum and energy equations, that governs the room’s turbulent flow domain. The experimental study was performed using (1/5) scaled room model of the actual dimensions of the room to simulate room air flow and visualize the flow pattern using smoke generated from burnt herbs and collected in a smoke generator to delivered through
... Show MoreThe study aims to investigate the relationship between the gender diversity of board director, the accounting conservatism and firm value in Iraqi firms. The sample was represented by 30 Iraqi firms listed on the Iraqi market over the period 2017. The research was based on the main hypothesis that gender diversity has a positive relationship with conservatism and firm value, that conservatism as an intermediate variable will enhance the positive relationship between gender diversity and firm value. The study reached results that support the research hypotheses. The appointment of females to the board helps improve the provision of conservative accounting information and avoids overstate when reporting earnings. Based on these res
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