Ultrasonic absorption, velocity, viscosity, adiabatic compressibility, relaxation time and relaxation amplitude measurements are reported on different concentrations of poly(acrylic acid) solutions in common solvent water using pulsed ultrasonic apparatus technique operating at 26 kHz and 30 ºC. Results show an increase of velocity, viscosity, and absorption coefficient ،relaxation time and relaxation amplitude values with the increasing concentrations of the poly(acrylic acid) solutions, which might be the result of structural fluctuations of polymer molecules such as the segmental motions of the polymer chains. In contrast the compressibility decreases with the increasing concentration of this polymer. This study suggests there is an association between polymer and solvent molecules and also there is association between polymer molecules itself.
the sera levels of luteninizing hormone were investgaited prior tq surgery in 10 postmenopaisal women with benign and 10 postmenopausal women with maliganant healthy
The wall of the esophagus in Mabuya aurata septemaeniata as in high vertebrates consists of four layers, mucosa, submucosa,muscularis and serosa. Mucosa forms many unorganized short and long folds penetrate inside the esophageal cavity. Mucosa contains two sub layers, first one is lining epithelium which includes two types of cells, simple ciliated columnar epithelial cells and goblet cells, second one is lamina properia. Mucosa does not have muscularis mucosa. There is no esophageal glands within esophagus. Many special stains were used as (Periodic Acid Schiff (PAS)) to detect Carbohydrates in goblet cells. Alcian blue were used to detect the amount of goblet cells within lining epithelium. Alcian blue + PAS together confirm that the
... Show MoreAcrylic polymer/cement nanocomposites in dark and light colors have been developed for coating floors and swimming pools. This work aims to emphasize the effect of cement filling on the mechanical parameters, thermal stability, and wettability of acrylic polymer. The preparation was carried out using the casting method from acrylic polymer coating solution, which was added to cement nanoparticles (65 nm) with weight concentrations of (0, 1, 2, 4, and 8 wt%) to achieve high-quality specifications and good adhesion. Maximum impact strength and Hardness shore A were observed at cement ratios of 2 wt% and 4 wt%, respectively. Changing the filling ratio has a significant effect on the strain of the nanocomposites. The contact angle was i
... Show MoreBackground: Polycystic vary syndrome (PCOS) is a common endocrine disorder, affecting up to 10% of women of reproductive age. The cardinal features of PCOS are hyperandrogenism (HA) and oligo-anovulation. Many work teams recently have relate the severity of PCOS with Anti mullerian hormone (AMH) or antral follicle count (AFC). Objective: 1) to confirm if there is an increase of serum AMH in this group of patients with PCOS, 2) to relate the AMH level to the follicle status at ultrasound (U/S) in this group, and 3) to search if AMH or AFC can serve as surrogate for the definition of PCOS.
Patients and methods: Twenty five (control) and anoth
... Show Morein this paper the second order neutral differential equations are incestigated are were we give some new suffucient conditions for all nonoscillatory
Praise be to God, who created people from one soul, and made her husband, and prayers and peace be upon His Messenger, Mercy given and the grace given, and on a machine and companions pure. Divorce cases have increased in recent years in a worrying manner, especially since divorce has unforeseen consequences at the individual and social levels. The source of concern stems from the fact that the cohesion and integrity of society starts from a family as it is the cornerstone of the social structure, which is the foundation upon which the large society is based. Marital life may suffer from problems and obstacles that are difficult to solve, so the man presents the divorce of his wife and that the phenomenon of divorce is not a result of it, b
... Show MoreThis work aims to analyse the dynamic behaviours of the forest pest system. We confirm the forest pest system in plane for limit cycles bifurcating existence from a Hopf bifurcation under certain conditions by using the first Lyapunov coefficient and the second-order of averaging theory. It is shown that all stationary points in this system have Hopf bifurcation points and provide an estimation of the bifurcating limit cycles.
Objective: The aim of this study was to evaluate the effect of pumice, burning investment material
and black sand on the surface roughness of heat cure acrylic resin.
Methodology: Sixty specimens were prepared from pink heat cure acrylic resin, the specimens
where grouped into; 20 specimens which polished with pumice and water (control group); 20
specimens which polished with investment material (after burning it) and water; and 20 specimens
which polished with black sand and water. The average surface roughness of specimens after
polishing procedure had been determined by profilometer (surface roughness tester).
Results: Through the application of ANOVA and LSD tests, the result of this study showed that there
wa
Background: The main drawback of soft lining materials was that they debonded from the denture base after a certain period of usage. Therefore, the purpose of this research was to determine the impact of oxygen and argon plasma treatment on the shear bonding strength of soft liners to two different kinds of denture base materials: conventional acrylic resin and high impact acrylic resin. Materials and Methods: Heat cure conventional and high impact acrylic blocks (40 for each group) were prepared. A soft liner connected the final test specimen of two blocks of each acrylic material. Shear bond strength (SBS) was assessed using universal testing machine. Additional blocks were also prepared for analyzing Vickers microhardness, contact ang
... Show MoreIn this study two types of extraction solvents were used to extract the undesirable polyaromatics, the first solvent was furfural which was used today in the Iraqi refineries and the second was NMP (N-methyl-2-pyrrolidone).
The studied effecting variables of extraction are extraction temperature ranged from 70 to 110°C and solvent to oil ratio in the range from 1:1 to 4:1.
The results of this investigation show that the viscosity index of mixed-medium lubricating oil fraction increases with increasing extraction temperature and reaches 107.82 for NMP extraction at extraction temperature 110°C and solvent to oil ratio 4:1, while the viscosity index reaches to 101 for furfural extraction at the same extraction temperature and same