The performance of single and two stage solar concentrator were studied ' " The ratio of the primary to the secondary mirrors diameter is taking to be 0.5, depending on the theoretical calculation for the accumulated energy by the concentrator with ratio between 0.0 to 0.9. The design of the systems were designed and examined by using a ray-tracing program. The efficiency of the single and the two stage concentrators are calculated and compared with and without cooling systems.

In this paper, a single-phase boost type ac-dc converter with power factor correction (PFC) technique is designed and implemented. A current mode control at a constant switching frequency is used as a control strategy for PFC converter. The PFC converter is a single-stage singleswitch boost converter that uses a current shaping technique to reshape the non-sinusoidal input current drawn by the bulky capacitor in the conventional rectifier. This technique should provide an input current with almost free-harmonics, comply with the IEC61000-3-2 limits, and a system operates with near unity power factor. The other function of the boost converter that should be
accomplished is to provide a regulated DC output voltage. The complete designed

Background: Decalcification of surface enamel adjacent to fixed orthodontic appliances, in the form of white spot lesions, is a wide spread and familiar well-known side effect of orthodontic treatment. The present study was carried out to evaluate the effect of enamel protective agent (Clinpro white varnish) on shear and tensile bond strength of Dentaurum orthodontic stainless steel brackets by using 3M Unitek and Ormco as orthodontic adhesive agents. Materials and methods: Sixty-four extracted human upper first premolar teeth were selected and randomly divided into two groups with 32 teeth each, representing the shear and tensile bond strength testing groups. Then according to the type of bonding adhesive and the addition of Clinpro before

It has been a well-known practice to use seeds and the essential oil of Carum copticum as a strongly  antiseptic ,  antispasmodic ,  aromatic  , bitter ,  diaphoretic  ,  digestive  ,  diuretic , expectorant  and tonic. Also used for cure influenza, asthma, and rheumatoid arthritis. To our knowledge it will be the first time to use the seeds of this herb as a urinary tract stone lithotripsy.This research aimed to the use of these seeds as a lithotripsian against different types of urinary stones and determine the efficiency of these preparation against which types of stone.A liquid solution was prepared from dissolving the seeds powder in cow milk and then concentration this prep

Background: evaluate the effects of three different intracoronal bleaching agents on the shear bond strengths (SBS) and failure site of stainless steel and monocrystalline (sapphire) orthodontic brackets bonded to endodontically treated teeth using light cured orthodontic adhesive in vitro. Materials and methods: Eighty extracted sound human upper first premolars were selected, endondontically treated and randomly divided equally (according to the type of the brackets used) into two main groups (n = 40 per group). Each main group were subdivided (according to the bleaching agent used) into four subgroups 10 teeth each; as following : control (un bleached) group, hydrogen peroxide group (Hp) 35%, carbamide peroxide group (CP) 37% group and s

Nerium oleander known as oleander has belonged to the poisonous plants its habitat in a tropical andsubtropical region. The chemical analysis with GC-Mass of the alcoholic extract of oleander leaves revealedthat this plant has many chemical compounds more than 80 compounds and high-peaks about 29 compoundswhich are represented by alkaloids, phenol, terpenes, and fatty acid. HPLC analysis showed many essentialoils that have many biological effects.To evaluate the antibacterial activity of the alcoholic extract of N. oleander against locally isolatedPseudomonas aeroginosa the broth micro-dilution method was adapted to different concentrations werestarted from 3.9 to1000 mg/ml. The results revealed that the alcoholic extract has antiba

Observed visually prominent lumps on the surface of the lung or embedded in lung tissue and microscopically Register Anfaj thrombosis with pulmonary carcinoma that took shape food or with the composition of the vesicles papillomavirus lining cells cubic vertical or connective tissue and increase