Journal of Basrah Researches (Sciences)

The cavity perturbation method has been used to measure the dielectric constant and loss factor of
(polystyrene/carbon black) composites of different concentrations of carbon black fillers (5 wt% -
20 wt%) . The used cavity is rectangular in shape that exited the dominant mode (TE101) with a
theoretical resonance frequency of about (9.7757 GHz). The composite having (20 wt%) carbon black
fillers shows higher values of the dielectric constant (???? ???? ???? 8.96 ) and loss tangent ( tan???? ???? 0.089 ).
Finally composites are very useful for electromagnetic shielding (SE) and radar absorbing materials
(RAM).In general ,in case of the heterogeneous mixture, the behavior of the dielectric constant and
loss tangent is found to increase with the increase of carbon black(CB) fillers.

By re-expressing of the master equations model of quantum dots (QDs) laser theory by C. Gies
et.al (2007), we have added a dynamical delay factor to the s-shall population’s equations to take into
account the retardation procedure. This addition has led to theoretical results nearly in isomorphism
with experimental data . We present a theoretical simulation of characteristics and the turn-on
dynamics of InGaAs/GaAs semiconductor QD laser output lasing with CW wavelength of 1.3????m at
room-temperature including the photon-assisted polarization contribution.

In this article we consider a set of repeated measurements on p variables on each of the n
individuals. Thus, data on each individual is unbalanced data. The n individuals themselves may be
divided and randomly assigned to g groups. We test the usual hypotheses and studied the likehood
ratio test of this test ,assuming that the data on an individual has a covariance matrix which is a
Kronecker product of two positive definite matrices.

I n this article we consider one-way Multivariate repeated measurements analysis of covariance
model (MRM ANCOVA), which contains one between-units factor (Group with q levels) ,one withinunits
factor (Time with p levels) and one covariate ( 1 Z ) . For this model the covariate is timeindependent,
that is measured only once . The test statistics of various hypotheses on between-unites
factors, within-units factors and the interaction between them are given

The study was included the isolation , the purification and the cultivation two cyanobacterial
species isolated from AL-Khandaq river , Basrah city/ southern of Iraq represented by species Nostoc
muscurum ( Agardh) and Anabaena variabilis ( kuetz.) in addition to green algae ( non- toxic alga)
Chlorella vulgaris Beijerinck with measuring their growth constant ( K ) and generation time ( G ) .
This study showed that the ability of two cyanobacterial species to produce toxins type hepatotoxins
( Microcystin-LR ) as the first time in Iraq especially for the two types above. Hepatotoxin was
identified after the extraction and the purification by using HPLC technique ( High performance liquid
chromatography ) to detect the purity and the concentration of this toxin , in addition Infra-red
technique was used to investigate chemical active groups of hepatotoxoins. The Concentration of
hepatotoxins reached to 28.57 μg/ml for alga N. muscurum and 4.61 μg/ml for species A. variabilis
respectively . The two cyanobacterial species were used as food for three economic fish larvae
represented by Cyprinus carpio L., Hypophthalmicthyes molitrix VaL. and Ctenopharyngodon idella
Val. The results showed significant decreasing in mean of weight , length and survival percentage for
all fish larvae when fed on toxic species compared with fed on non- toxic species C. vulgaris . Also
the results showed toxic effect of two cyanobacterial species on some zooplankton species
represented by Artemia salina , Daphnia magna and Brachionus calyciflorous after fed on toxic
species . This feeding led to significantly decreasing p???? 0.05 in the mean numbers of zooplankton
compared with those fed on non- toxic microalga C. vulgaris .

T he present study was designed to evaluate the relationship between ß-carotene as antioxidant
with malondialdehyde (oxidative stress) in the serum of asthmatic patients. In this study, a total
number of (50) asthmatic patients (24 males, 26 females) visiting Allergic and Asthma Medical Center
in Basrah city were involved and according to age, sex, severity, smoking and family history. From
each patient serum blood samples were collected to estimate the malondialdehyde (MDA) and ßcarotene.
In addition, (50) healthy subjects were investigated as a control group. We found that a
highly significant increase lipid peroxidation measured as MDA (p< 0.01) for all asthmatic patients as
compared to healthy control.
A lso the (MDA) serum level increases significantly (p< 0.05) with age and severity, while a
highly significant (p< 0.01) is with smoker patients and positive family history. The study also
revealed a statistically significant decrease (p< 0.01) in ß-carotene serum level in all asthmatic
patients as compared to healthy control. In regard to age and severity, serum ß-carotene level
decreased significantly (p< 0.05) while with smoker patients and positive family history a highly
significant decrease (p< 0.01). There were no significant changes in the (MDA) and ß-carotene levels
between male and female patients. Moreover, a negative correlation was also observed between ßcarotene
with (MDA) level in the patient group with these variables.
In conclusion, asthmatic patients suffer a high degree of reactive oxygen species (ROS) formation
causing considerable oxidative stress indicated by high level oxidant (MDA) and low level of the
antioxidant ß-carotene.