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Multi-Channel Distributed DSA Networks: Connectivity and Rendezvous Tradeoffs
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In this paper, we investigate and characterize the effects of multi-channel and rendezvous protocols on the connectivity of dynamic spectrum access networks using percolation theory. In particular, we focus on the scenario where the secondary nodes have plenty of vacant channels to choose from a phenomenon which we define as channel abundance. To cope with the existence of multi-channel, we use two types of rendezvous protocols: naive ones which do not guarantee a common channel and advanced ones which do. We show that, with more channel abundance, even with the use of either type of rendezvous protocols, it becomes difficult for two nodes to agree on a common channel, thereby, potentially remaining invisible to each other. We model this invisibility as a Poisson thinning process and show that invisibility is even more pronounced with channel abundance. Following the disk graph model, we represent the multiple channels as parallel edges in a graph and build a multi-layered graph (MLG) in R2. In order to study the connectivity, we show how percolation occurs in the MLG by coupling it with a typical discrete percolation. Using a Boolean model and the MLG, we study both cases of primaries' absence and presence. For both cases, we define and characterize connectivity of the secondary network in terms of the available number of channels, deployment densities, number of simultaneous transmissions per node, and communication range. When primary users are absent, we derive the critical number of channels which maintains supercriticality of the secondary network. When primary users are present, we characterize and analyze the connectivity for all the regions: channel abundance, optimal, and channel deprivation. For each region we show the requirement and the outcome of using either type of rendezvous techniques. Moreover, we find the tradeoff between deployment-density versus rendezvous probability which results in a connected network. Our results can be used to decide on the goodness of any channel rendezvous algorithm by computing the expected resultant connectivity. They also provide a guideline for achieving connectivity using minimal resources.

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Publication Date
Sun Jul 19 2020
Journal Name
Egyptian Journal Of Chemistry
Synthesis, characterization, industrial and biological application of Co(II),Ni(II),Cu(II) and Zn(II) complexes with azo ligand derived from metoclopramide hydrochloride and 3,5-dimethylphenol
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Four complexes of Co(II),Ni(II),Cu(II) and Zn(II) with the azo ligand (4-chloro-N-(2-(dimethylamino)ethyl)-5-((2-hydroxy-4,6-dimethylphenol)diazenyl)-2-methoxybenzamide) L. The structure of ligand and complexes were confirmed on the basis of their analytical and spectral data, these dyes were tested as dyeing in cotton fabric, and also testing in light and cleaner firmness. Also, antimicrobial and antifungal activities of ligand and their complexes were evaluated and the results showed that the ZnL compound showed the higher antibacterial activity with inhibition zone of 13mm against Staphyloco-ccus epidermidis, Steptococcus sp. and Escherichia coli compared with ligand and other metal complexes .In case of ZnL compound the antifungal activ

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Publication Date
Sun Feb 03 2019
Journal Name
Iraqi Journal Of Physics
Study of charge density distributions, elastic charge form factors and root-mean square radii for 4He, 12C and 16O nuclei using Woods- Saxon and harmonic-oscillator potentials
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The nuclear charge density distributions, form factors and
corresponding proton, charge, neutron, and matter root mean square
radii for stable 4He, 12C, and 16O nuclei have been calculated using
single-particle radial wave functions of Woods-Saxon potential and
harmonic-oscillator potential for comparison. The calculations for the
ground charge density distributions using the Woods-Saxon potential
show good agreement with experimental data for 4He nucleus while
the results for 12C and 16O nuclei are better in harmonic-oscillator
potential. The calculated elastic charge form factors in Woods-Saxon
potential are better than the results of harmonic-oscillator potential.
Finally, the calculated root mean square

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Publication Date
Tue Dec 01 2009
Journal Name
Journal Of Economics And Administrative Sciences
The global financial crisis and the role of war and its characterization as solutions "The objective roots and the legal possibility of the crisis in economic thought"
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في البداية اود الاشارة الى ان فهم حقيقة الازمة هو ذو جانب فني يتعلق بالجينات الوراثية لنظام يملك في احيناته قدرة عالية على تفريخ المشتقات. هذا النظام الذي يزداد عقما وتدميرا يزداد قدرة على خلق النقود الائتمانية/المشتقات، وكلما اقتربنا اكثر من فهم هذا الجانب كلما اسقطت في ايدينا تلك التوصيفات الاكاديمية الجاهزة في نقص الرقابة والاشراف، تركيز المخاطر،....الخ التي تناولتها الكتابات الشائعة في معظم طروحات

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Publication Date
Thu Jun 30 2022
Journal Name
Iraqi Journal Of Market Research And Consumer Protection
STUDY OF SOME GROWTH CRITERIA AND YIELD OF SOYBEAN CROP WITH THE EFFECT OF BORON AND SOME GROWTH REGULATORS: STUDY OF SOME GROWTH CRITERIA AND YIELD OF SOYBEAN CROP WITH THE EFFECT OF BORON AND SOME GROWTH REGULATORS
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The study was conducted at research station A, department of field crops, college of agricultural engineering sciences, university of Baghdad during summer 2021 to evaluate the effect of boron and some growth regulators on some growth criteria and yield of soybean crop (cv. shimaa). The experiment  was carried out according to split plots by using randomized complete block design with three replications. The main plots included three concentrations of boron (75, 150 and 225) mg.L-1, the sub-plots included three levels of growth regulators, spraying kinetin (100 mg. L-1), spraying ethrel (200 mg.L-1) and spraying kinetin (100 mg.L-1) + spraying ethrel (200 mg.L-1) as

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Publication Date
Tue Jun 30 2020
Journal Name
Iraqi Journal Of Market Research And Consumer Protection
FACTORY OF SORTING AND RECYCLING OF WASTE IN THE DISTRICT OF AL-MAHMOUDIYAH BETWEEN THE ECONOMIC AND ENVIRONMENTAL IMPACT: FACTORY OF SORTING AND RECYCLING OF WASTE IN THE DISTRICT OF AL-MAHMOUDIYAH BETWEEN THE ECONOMIC AND ENVIRONMENTAL IMPACT
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The waste sorting and recycling plant in the district of al- Mahmudiya (Yusufiya) is the only laboratory in Baghdad governorate. It is the only one in Iraq that collects and recycles waste. After sorting, we have packages of raw materials (aluminum cans, glass bottles, plastic bottles, Nylon bags) as well as natural fertilizers (food residues and others) and a sanitary landfill with specifications that meet international standards; However, the absence of a structure for the management of the plant (manager, assistant manager, accountant, etc.) in addition to the non-supply of waste on a daily and continuous basis and the lack of cooperation of the Municipality of Baghdad with the management of the plant led to delay in the work

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Publication Date
Sun Mar 13 2016
Journal Name
Iraqi Journal Of Market Research And Consumer Protection
Isolation and Identification of food Probiotic Saccharomyces boulardii by using traditional methods, Vitek 2 system and molecular identification methods.: Isolation and Identification of food Probiotic Saccharomyces boulardii by using traditional methods, Vitek 2 system and molecular identification methods.
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This study was aimed to isolate and identify Saccharomyces boulardii from Mangosteen fruits (Garcinia mangostana L.) by traditional and molecular identification methods To get safe and healthy foods probiotics for use, The isolates and two commercial strains were subjected to cultural, morphological and biochemical tests, The colonies of the isolates were spherical, smooth, mucoidal, dull and white to cream colour on SD agar media .The shape of cells was globose to ovoid and sometimes with budding, in a single form or clustered like a beehive. The isolates and two commercial strains were unable to metabolized galactose and lactose , Results shows that all isolates were unable to utilize potassium nitrate and not grow in the presence of (

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Publication Date
Wed Jun 30 2021
Journal Name
Iraqi Journal Of Market Research And Consumer Protection
SYNTHESIS, CHARACTERIZATION, AND STUDY THE BIOLOGICAL ACTIVITY OF SOME SCHIFF'S BASES, AND 1,3 - OXAZEPINE COMPOUNDS DERIVED FROM SULFAMETHOXAZOLE DRUG: SYNTHESIS, CHARACTERIZATION, AND STUDY THE BIOLOGICAL ACTIVITY OF SOME SCHIFF'S BASES, AND 1,3 - OXAZEPINE COMPOUNDS DERIVED FROM SULFAMETHOXAZOLE DRUG
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This study including synthesis of some new Schiff bases compounds [16] from the reaction of Sulfamethoxazole drug with some aromatic aldehydes in classical Schiff base method then treatment Schiff  bases with succinic anhydride to get oxazepines rings [7-11]These derivatives were characterized by melting point, FTIR, 1H NMR and mass spectra. Some of synthesized compounds were evaluated in vitro for their antibacterial activities against three kinds of pathogenic strains Staphylococcus aureus, Escherichia coli

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Publication Date
Thu Jan 31 2019
Journal Name
Journal Of The College Of Education For Women
Urbanization and urban growth in Iraq
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The development issue is considered as one of the most important matters of concern to governments, intellectuals and specialists in the contemporary world, especially in developing countries that are trying hard to move out of the afflicting underdevelopment domain to a brighter future and achieve the aspirations of those countries through organized planning which take advantage of available resources, whether material or humanitarian, in the best way possible.
The development process are taking place at multiple levels ranging from national to regional to local where the community is stimulated and excited for the cooperation, participation and preparation to perform planned change in the methods of thinking, acting and production.<

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Publication Date
Sun Jun 01 2014
Journal Name
Baghdad Science Journal
Liquid crystalline dendrimer: Sythesis and Chracterization
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A new family of nematic liquid crystal dendrimers derived from 3,5-dihydroxybenzoic acid were synthesized. The synthesis of the dendrimers compounds shows the influence of the dendritic core on the mesomorphic properties. The liquid crystalline properties were studied by polarizing optical microscopy (POM) equipped with a hot stage, the structures of the synthesized compounds characterized using FTIR and 1HNMR spectroscopy.

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Publication Date
Fri Jan 01 2016
Journal Name
Al–bahith Al–a'alami
Political Consultation and Public Opinion Polls
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Increasingly important public opinion polls steadily .... especially in electoral campaigns, sheds searchlight on the side of the US elections, in different time periods, and cited the words of experts and people involved in it, and reviews Find great development that took place in the polls and what could happen to this work It is important in the future. Display search for certain types of polls, dividing them on as stated by the experts in the United States... This division shows that the surveys of the most political processes and accuracy of information, and that their Money being made and companies specialized in the administration of this type of measuring public opinion ..... what is returned decision-making, for example, in conj

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