Cognitive radio is observed as a new approach, which could be cope with the spectral limitations. This approach is designed to detect whether a particular segment of the radio spectrum is currently in use and to jump into the temporarily unused spectrum rapidly without interfering with the transmissions of other users. CR is the promising radio technology which aims to detect and utilize the temporally unused spectrum bands by sensing its radio environment in order to improve spectrum utilization. To enhance the sensing performance, cooperative spectrum sensing has been proposed. However, when the number of cognitive user tends to be very large, the bandwidth for reporting sensing results to the common receiver will be very huge. In this paper we described interference avoidance in spectrum sensing and then we illustrated the benefits of cooperation in cognitive radio by considering a simple user network and showing improvement in agility , we propose a practical scheme which allows cooperation between cognitive users.
Abstract
The research aims to stand on the practice of operations management of solid waste in the city of Hilla, carried out by the mayor of Hilla Directorate - solid and the environment Waste Division, through field visits and personal interview to officials of the municipal departments and units of its data collection and information related to solid waste, and assess the current status of the processes of collection and transport waste through the questionnaire that had been prepared for citizens and employees, the search reach a set of conclusions was the most important, operations carried out by the municipality of Hilla Directorate only limited to two (collection, transportation and disposal of wa
... Show MoreThe aim of the present study is to compare the biochemical action of the three vaccines taken in Iraq: Pfizer Biontech, AstraZeneca Oxford and Sinopharm based on biochemical parameters. Seventy COVID-19 Iraqi patients ( males and females ) were participated in the present study and classified into 7 groups : Gc : COVID-19 patients ( without vaccine ) , Gp1: COVID-19 patients took one dose of Pfizer Biontech, Gp2 : COVID-19 patients took two doses of Pfizer Biontech, Ga1 : patients took one dose of AstraZeneca Oxford vaccine , Ga2: patients took two doses of AstraZeneca Oxford vaccine , Gs1 : patients took one dose of Sinopharm vaccine and Gs2:
... Show MoreDrug –induced nephrotoxicity is an important cause of renal failure. Aminoglycoside antibiotics, such as amikacin, which causes ototoxicity and nephrtotoxicity as a main side effects, this is focused on the use of natural materials as antioxidants against the toxic oxidative action that exert a cell damaging effect. The most important one of these materials is the honey. The aim of this work is to evaluate the antioxidant effects of honey against amikacin – induced nephrotoxicity.18 albino rats divided into 3 groups (6 rats per each group), group 1 received I.P daily dose of normal saline (control), group 2 received (35 mg/kg/day) I.P dose of amikacin ,and group 3 received (35mg/kg/day) of amikacin I.P dose in combina
... Show MorePolyaniline films were successfully synthesized in this study using an oxidative polymerization method at temperatures ranging from 0 to 4 ° C. Polyaniline films were deposited using a single step of chemical oxidative polymerization rather than electrochemical polymerization. The polyaniline was examined using FTIR, XRD, SEM, AFM, and Four Point Probe. This result demonstrates that polyaniline synthesized using this method has a uniform morphology, small size (17 to 40) nm, high crystallinity, and high conductivity (9.42 s/cm).
Abstract
In this paper presents two dimensional turbulent flow of different nanofluids and ribs configuration in a circular tube have been numerically investigation using FLUENT 6.3.26. Two samples of CuO and, ZnO nanoparticles with 2% v/v concentration and 40 nm as nanoparticle diameter combined with trapezoidalribs with aspect ratio of p/d=5.72 in a constant tube surface heat flux were conducted for simulation. The results showed that heat flow as Nusselt number for all cases raises with Reynolds number and volume fraction of nanofluid, likewise the results also reveal that ZnO with volume fractions of 2% in trapezoidal ribs offered highest Nusselt number at Reynolds number of Re= 30000.
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... Show MoreThis study done was carried out identify the species of parasitical lice on. White cheeked bulbul(Pycnonotus leucotis).For this purpose 24 birds were collected from AlDiwaniya city and examined externally for the lice.The results showed that P. leucotis was infested with five species of chewing lice with a total infestation ratio of 87.5% .These species were:- Menacanthus sp., Columbicola columbae , Bonomiella columba , Coloceras damicorne and Alcedoecus sp. The result of this study represents the first isolation of these species from white cheeked bulbul in Iraq.The species were recorded from P. leucotis as a new host for such parasites. Menacanthus sp.
... Show MoreDrug-induced acute kidney injury is a serious disorder. Oxidative stress has a key role in its initiation and progression. In this study, the possible ameliorative effect of fimasartan against methotrexate-induced nephrotoxicity was investigated in comparison with α-tocopherol in rats. Wistar rats were allocated into six groups and treated as follows: group Ӏ received water on a daily basis for 8 successive days; group ӀӀ received methotrexate (20 mg/kg) on day 1, followed by water for 7 successive days; group ӀӀӀ received fimasartan (3 mg/kg/day) for 7 successive days; group IV received α-tocopherol (1 g/kg/day) for 7 successive days; group V re
... Show MoreDoppler broadening technique is suggested to monitor the development of tumours. It depends on the sensitivity of positronium (Ps) annihilation parameters to the sub- microstructural changes in biological tissues. This technique uses high resolution HpGe detector to measure the lineshape parameters (S and W) in normal mice's mammary tissues and adenocarcinoma mammary tissues as a function of tumour growth. The results demonstrate that the central parameter (S) decreases and the wing parameter (W) increases as the tumour grow. It is found that the S parameter changes considerably with the distribution of voids which are affected by the tumour development. Therefore the present technique can successfully be employed to monitor the developm
... Show MoreThe research aims to explain the References of receiving the explicit and implicit knowledge mentioned in the Noble Qur'an. The two researchers adopted the documentary and inductive approach to study the topic. Among the conclusions of the research: The Noble Qur'an dealt with many terms and concepts that refer to the References of making explicit knowledge available, including books, which were represented by the divine books (the Qur'an, the Torah, the Zabur and the Gospel) and their concepts (the book, the Qur'an, the guidance, the remembrance, the revelation, the light, the newspapers, the plates). He dealt with many concepts that refer to the References of providing tacit knowledge, which was represented by the communication between tw
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