Kirkuk Journal of Science

The aim of this research is to improve the flow properties of polymers,
in particular viscosity, by mixing polymers to be used in various fields.
Samples prepared by stirring polyvinyl alcohol on fire for half a second
in a fixed weight ratio with divergent weight ratios of polyethylene
glycol and polyvinylpyrrolidone, both separately. Other samples were
prepared in the same way by mixing the three polymers followed by
measuring the molecular weight of all the samples. This method of
preparation made the polymers insoluble in water, therefore nitric acid
was used to dissolve them. Flow time of the solvent and all solutions
were measured, which was used to calculate the viscosities, It has been
shown that these viscosities increase with increasing concentrations of
polymers in solutions by establishing a positive relationship between
them, It was found that the intrinsic viscosity decreases with increasing
concentrations after being graphed using intrinsic viscosity calculations
from the relationship between specific viscosity and relative viscosity
logogram with concentration. These results may be used in industrial
medical applications as well as scientific studies.

This paper is concerned with the Orthogonal Frequency Division Multiplexing (OFDM) system that is adopted by a wireless communication
system for transmitting multicarrier modulated signals simultaneously
with robustness against interference and noise facing the system. It
presents a significant issue related to the OFDM system known as the
raise of Peak to Average Power Ratio (PAPR) that is the high peaks of
OFDM signals compared to its average power. Increasing the PAPR
yields in the component devices of the OFDM system does not cope
with the high peaks resulting in distortion and signal losses. Therefore,
the objective of this article is to review different approaches of PAPR
reduction techniques and compare them to select the best technique for
a particular system. The approaches are mainly of three classifications;
distortion, probabilistic, and coding schemes with each including several
techniques.

The Degala Basin is one of the water reservoirs in the heart of the
Degala sub-district, roughly 50 kilometers east of Erbil City. Samples
were collected monthly from different sites of Degala Basin during
October 2020 to August 2021 to determine physicochemical and
biological properties EC, TDS, Chloride, Na, K, Ca hardness, total
alkalinity, nitrate, and DO, pH, total hardness, Mg hardness, and Sulfate.
The statistical analysis of the data revealed that there were significant
differences in physico-chemical parameters between the two sites, with
high significant relationships for (EC, TDS, chloride, Na, K, Ca hardness,
total alkalinity, nitrate, and DO) and low significant relationships for
(pH, total hardness, Mg hardness, and Sulfate) at the (p ≤ 0.05) for all
parameters studied different algal species obtained from all sampling
sites in Degala basin revealed the presence of a variety of algal species.
There is small change in the pH value during the observation period
among upstream, basin and downstream. Different genera of algae
found in Degala basin.