Semiconductor laser is used in processing many issues related to the scientific, military, medical, industrial and agricultural fields due to its unique properties such as coherence and high strength where GaN-based components are the most efficient in this field. Current technological developments mention to the strong connection of GaN with sustainable electronic and optoelectronic devices which have high-efficiency. The threshold current density of Al0.1Ga0.9N/GaN triple quantum well laser structure was investigated to determine best values of the parameters affecting the threshold current density that are well width, average thickness of active region, cavity length, reflectivity of cavity mirrors and optical confinement factor. The optimum value of the threshold current density is 2670 A/cm2 was obtained when the well width (w= 2.5 nm), reflectivity of cavity mirrors (R1=0.75, R2=0.9), cavity length (L=2mm), average thickness of active region (d= 11.5 nm), and optical confinement factor ( Γ= 0.034) at room temperature.
There are varieties of reasons lead for drilling horizontal wells rather than verticals. Increasing the recovery of oil, especially from thin or tight reservoir permeability is the most important parameter. East Baghdad oil field considered as a giant field with approximately more than 1billion barrel of a proved reserves accompanying recently to low production rate problems in many of the existing wells. It is important to say that presence of of horizontal wells in East Baghdad field especially by converting some of already drilled wells by re-entry drilling horizontal sections may provide one of best solutions for the primary development stage in East Baghdad field which may be followed by drilling new horizont
... Show MoreOne of the major problems facing the road construction engineer is the collapsible granular soil which may be used for embankment construction. Problems appears when such compacted soil come in touch with water, it exhibits cracking and uncontrolled settlement. Collapsible soils are defined as any unsaturated soil that goes through a radical rearrangement of practice and great loss of volume upon wetting, with or without additional loading. An attempt has been made in this investigation to stabilize the collapsible soil of Nasiriya with asphalt emulsion. Specimens of pure and asphalt emulsion stabilized soil have been prepared using optimum fluid content and tested. The first group of specimens of (60x60x20) cm have been tested for direct s
... Show MoreNutlets of 22 taxa of Stachys (13 species and seven subspecies and two varieties), representing seven of the currently recognized sections distributed in northern Iraq were examined by light microscope. The basic shape of nutlets in most taxa studied is Obovoid, but Oblong also found in S.megalodanta Hausskn.& Bornm. ex P.H.Davis, S.setirefa C.A.Mey. subsp daenensis (Gandog.) Rech.f.and S. kurdica Boiss.& Hohen. var.kurdica, while the Subgloboid shape found in S. iberica M.Bieb. and S. inflata Benth., more over the Broad triangular shape was found in S. nephrophylla Rech.f. and S.lanigera (Bornm.) Rech.f.., the biggest size of nutlets was found in S.inflata L. and the smallest was in S.melampyroides Hand.-Mzt. Regarding sculpturing pa
... Show MoreA theoretical study by using computer model is presented to study the energy characteristics of the vibrational – rotational levels as a function of the vibrational and rotational quantum number, respectively. The calculations were based on the basis of a multilevel model taking into account the non-equilibrium population of the rotational levels. The computational investigation has been performed to examine the vibrational-rotational characteristics of some hydrogen halides chemical laser molecules. This program takes into account the various molecules of chemical lasers such as, Hydrogen Fluoride (HF), Deuterium Fluoride (DF), Hydrogen Chloride (HCl), and Deuterium Chloride (DCl). The practical difficulties associated with this
... Show MoreBackground: The treatment of articular cartilage defects is one of the most clinical challeng for orthopedic surgeons. Articular cartilage is a highly organized tissue with complex biomechanical properties and substantial durability. However, it has a poor ability for healing, and damage from trauma or degeneration can result in morbidity and functional impairment. debilitating joint pain, dysfunction, and degenerative arthritis Objectives: The purpose of study is to show effectiveness of micro fracture arthroscopy as a method of treatment for such problem . Type of the study: Cros
... Show MoreTwenty isolates of Serratia marcescens were isolated from inflammation of the urinary tract (UTI)., These isolates were found to produce hemolysin as indicated by blood agar plates in which the hemolysis of red blood cell indicate a positive result. Isolates were selected according to their hemolysis activity by measuring absorbance of hemoglobin at 405 nm that released from red blood cell. Hemolysin was completely purified using 50-75% saturation of ammonium sulphate followed by ion exchange chromatography with DEAE-cellulose then gel filtration chromatography by sepharose 4B. Accordingly molecular weight for the purified toxin was estimated as 45 KD.
This paper presents stochastic analysis using the perturbation method to model the structure of a container to verify the distributions of probability of maximum and minimum axial forces reactions in piles. The proposed simulation of a container port terminal under 11 scenarios of load combinations was presented. The probability distributions for live loads are assigned according to the input parameters of simulation data. Part of the load itself is implicitly combined such as vertical live load which includes the weight of equipment and containers and wind load. The structural model was simulated in the software STAAD Pro., while the statistical analyses were performed with MATLAB. The results demonstrated that, the most significant extern
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