As the bit rate of fiber optic transmission systems is increased to more than , the system will suffer from an important random phenomena, which is called polarization mode dispersion. This phenomenon contributes effectively to: increasing pulse width, power decreasing, time jittering, and shape distortion. The time jittering means that the pulse center will shift to left or right. So that, time jittering leads to interference between neighboring pulses. On the other hand, increasing bit period will prevent the possibility of sending high rates. In this paper, an accurate mathematical analysis to increase the rates of transmission, which contain all physical random variables that contribute to determine the transmission rates, is presented. Thereafter, new mathematical expressions for: pulse power, peak power, time jittering, pulse width, and power penalty are derived. On the basis of these formulas, one can choose a certain operating values to reduce or prevent the effects of polarization mode dispersion.
After the success of the reforms Keynesian save the capitalist system from collapse and to apply the concepts of state intervention in economic activity in order to revive aggregate demand to achieve the purposes of macro-economic policies which draw their scope of economic (John Keynes) theory of effective demand, which created the new role of the state away from the classical concepts. Valley transmission role of the State of (State Guardian) to the process of state overlapping that increased and social functions have become responsible for raising the standard of living of classes with limited incomes, in particular, and the rest of the classes in general, through the expansion of the delivery of public servic
... Show MoreThe research tacklets the role of risks arising from the excessive use of derivative contracts for trading in financial crises, including the recent global financial crisis in (2008) which is known the mortgage crisis.
In order to prove the hypothesis of the research, the risk index of derivative contracts has been chosed as expressed in the measure of (value at risk) to be the main field for testing the hypothesis of research. The duration of the contract has been also chased for (15) years between the years (2001- 2015), the period preceding the global financial crisis, while the second represents the period of time that followed. The research reached a number of conclusions, bu
... Show MoreThis study is an objective literary study of the poems of Abu Dhu'ayb Al-Hudhali and Su'da Bint Al-Shamrdal. It aims to shed light on the philosophy of death in the poems, and the way this philosophy is treated by both poets. Thus, the main prominent poetic images have been addressed and the outstanding ones have been singled out. The study further investigates the intertextuality with other poetic verses and Quranic verses and reviews the deviation in their semantic, syntactic, and phonetic types. The study adopts the historical approach to examine the occasion of the poems by referring to several historical sources that indicate the seniority. It also adopts the and descriptive-analytical approach represented by the use of content anal
... Show MorePregnancy and delivery are physiological conditions that are marked by abrupt alterations to hormones, immunological and molecular characters. The current study aimed to evaluate oxytocin (OT), prolactin (PRL), cortisol and insulin growth factor-2 (IGF-2) levels as physiological biomarkers; programmed cell death protein-1 (PD-1), programmed cell death ligand-1 (PD-L1),interleukin-6 (IL-6) as immunological biomarkers, and single nucleotide polymorphisms (SNPs; rs53576 and rs2254298) of oxytocin receptor gene OXTR as molecular factors in samples of Iraqi women undergoing caesarean section (CS) and normal delivery (ND). Blood samples were collected from 96 pregnant women at term with ages ranging between 16-43 years. Regarding
... Show MoreThe consensus algorithm is the core mechanism of blockchain and is used to ensure data consistency among blockchain nodes. The PBFT consensus algorithm is widely used in alliance chains because it is resistant to Byzantine errors. However, the present PBFT (Practical Byzantine Fault Tolerance) still has issues with master node selection that is random and complicated communication. The IBFT consensus technique, which is enhanced, is proposed in this study and is based on node trust value and BLS (Boneh-Lynn-Shacham) aggregate signature. In IBFT, multi-level indicators are used to calculate the trust value of each node, and some nodes are selected to take part in network consensus as a result of this calculation. The master node is chosen
... Show MoreThis study was designed to investigate the hepatoprotective activity and antioxidant enzymes of purified Bauhinia variegate leaves extract and purified flowers extract were administered (200 mg/kg, orally once daily) to reduce the effect of carbon tetrachloride-damage in rat’sliver for three weeks. Thereafter, the levels of some serum biochemical factorssuch as alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase,and the activity of three different antioxidant enzymes (glutathione, superoxide dismutase, and catalase) were investigated.Liver homogenate can used to estimated antioxidant parameters: glutathione, superoxide dismutase and catalase. The purified Bauhinia variegate leaves and purified flowers significantly
... Show MoreThe current study was conducted in Baghdad governorate (Karkh and Al-Rasafa regions) which included collecting 50 samples of freshly slaughtered sheep meat randomly collected from local slaughter areas and approved governmental slaughterhouses (25 liver and 25 ulna muscles). The results of the aflatoxin B1 detection showed that all samples were contaminated with this toxin at different concentrations ranging from 25–422 ppb and 65–492 ppb for each ulna muscles and liver, respectively. The histopathological and immunological study was conducted in meat samples containing higher and lower concentrations of the toxin. The results of the pathological study in the liver revealed that the concentration (492 ppb) caused thickening of t
... Show MoreIn this study is the phenomenon of desertification risk assessment in the Abu Ghraib area west of Baghdad/Iraq, which has an area of about (384.168 km 2), that the annual mean temperature is more than (22 C). Rainfall was low, ranging from the (200 mm) per year for Iraq and (2.82) mm per year of the study area* temperature is high and evaporation is also high (mm 7.73) per year*, so the climate in general of the dry type and the system of soil moisture is the kind of Aridic (Torric). To this study was to identify three indicators to monitor for the period from 2001-2005 using GIS and these indicators are (soil, groundwater and the nature of land use), using ArcGIS 9.1. The results showed that the risk of desertification was part of the leve
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