PMMA (Poly methyl methacrylate) is considered one of the most commonly used materials in denture base fabrication due to its ideal properties. Although, a major problem with this resin is the frequent fractures due to heavy chewing forces which lead to early crack and fracture in clinical use. The addition of nanoparticles as filler performed in this study to enhance its selected mechanical properties. The Nano-additive effect investigated in normal circumstances and under a different temperature during water exposure. First, tests applied on the prepared samples at room temperature and then after exposure to water bath at (20, 40, 60) C° respectively. SEM, PSD, EDX were utilized for samples evaluation in this study. Flexural strength, shear stress, hardness value were evaluated for all samples, the tests applied periodically at (15, 30, 45) min. Interestingly, it is found that at the normal condition (NC) the cooperation of TiO2 NPs significantly improves the selected properties. The maximum increase is located at 4 wt % of TiO2 NPs addition. The results also showed that temperature increase accelerate the water permeability within all samples thus decrease the mechanical properties. Obviously, a better hardness value determined for the prepared nanocomposite comparing to the control group at the same test condition.
The experiment was conducted to study the effect of leaves extract of Salvia sclarea , Rosmarinus officinalis and Thymus vulgaris with 10% and 30% concentration on germination of seeds and growth of seedlings . The effect of these extracts on infection percentage of seeds decay and surface growth of Rhizoctonia solani . The results showed that the three extracts effected significantly to reduced percentage of seeds germination, acceleration of germination , promoter indicator , infection percentage of seeds decay and surface growth of R. solani especially in 30% concentration .
إسهام تطبيقات التكنولوجيا الرقمية في تطوير الكفاءات النحوية لطلبة اللغة الإسبانية في العراق.
Research objective: This research aims to unveil how to use the method of referral in understanding the Holy Quran.
The reason for choosing the research: The one that invited me to write on this topic is the importance of the referral method, so I liked the research in it, and unveiled this wonderful Qur’anic method, so that it helps to understand the intention of God Almighty in his dear book.
The research plan: The research was divided into three topics and a conclusion.
As for the first topic, it is divided into two requirements. The first requirement deals with the definition of referral language.
In the second re
Background: The association between facial types and dental arches forms has considerable implications in orthodontic diagnosis and treatment planning. The aim was to establish the maxillary and mandibular dental arches width and length in skeletal and dental class II division 1 and class III malocclusion groups, find out the most frequent dental arch form and facial type and the association between them and to check the gender differences. Materials and Methods: Frontal and lateral facial photographs and maxillary and mandibular occlussal photographs for 90 iraqi subjects with age 18-25 years old (45 males and 45 females) divided equally into three groups, the 1st group with class II division 1malocclusion (overjet more than 3mm but less t
... Show MoreObjective This study evaluated the effects of adding titanium oxide (TiO2) nanofillers on the tear strength, tensile strength, elongation percentage, and hardness of room-temperature-vulcanized (RTV) VST50F and high-temperature-vulcanized (HTV) Cosmesil M511 maxillofacial silicone elastomers. Methods Two types of maxillofacial elastomers, VST50F RTV and Cosmesil M511 HTV, were used. Nano-TiO2 powder was applied as a nanofiller. A total of 120 specimens were fabricated, 60 each of VST50F and Cosmesil M511. The specimens of each type of elastomer were divided into three equal groups on which tests were conducted for tear strength, tensile strength, and hardness i.e., 20 specimens were used for each test. Each group of 20 specimens was further
... Show MoreAn experimental investigation of the variation of argon discharge current with a glow and afterglow time intervals of a square discharge voltage was carried out at low pressure (6-11 mbar). The discharge was created between two circular metal electrodes of diameter (7.5 cm), separated horizontally by a distance (10 cm) at the two ends of a Pyrex cylindrical tube. A composite of two Gaussian functions has been suggested to fit and explain the variation graphs clearly. It is shown that the necessary times of glow and afterglow needed to attain a maximum discharge current are (70 us) and (60 us), respectively. The discharge current is observed to drop to the lowest value when the two times are serially longer than (85 us) and (72 u
... Show MoreThis paper displays the effect of uncoated and coated chopped carbon fibers with alumina Al2O3 or Tri calcium phosphate (TCP) on the impact strength of acrylic poly methyl methacrylate (PMMA) denture base resin. To improve bonding between carbon fibers and coating materials powders, the surface of carbon fibers has been treated with Para amino benzoic acid (C9H10N2O3) and poly vinyl alcohol (PVA) was also used. The morphology of the coating layers has been examined by field emission scanning electron microscope (FE-SEM). From the results, PMMA reinforced with uncoated chopped carbon fiber has high impact strength value but still have bad aesthetic. Samples prepared b
... Show MorePowders for (TiO 2 ) 1−x(MoO 3 ) x composites have been prepared with the use of a dry mix of TiO2 and MoO3 oxides with a variety of compositions (x = 0, 0.2, 0.4, 0.6, 0.8, and 1), then sintering at 1473 K. The materials have been ground and formed into pellets so that they could be used as targets for the pulsed laser deposition (PLD) process, which produced thin flms with a thickness of ≈150 nm on a glass substrate. When MoO3 is added to TiO2 , the crystal size has been observed to decrease from 33.3 to 25.8 nm, yet it after that continued to expand as MoO3 was added. The molybdenum ions were confrmed by XRD patterns, indicating that the substitution regarding Mo+6 ions for Ti +4 ions in TiO2 matrix is what is re
... Show More