In this paper, we use concepts and results from percolation theory to investigate and characterize the effects of multi-channels on the connectivity of Dynamic Spectrum Access networks. 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-channels, 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 protocol, 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 define and characterize connectivity of the secondary network in terms of the available number of channels, deployment densities, number of transceivers per node, and communication range. When primary users are absent, we derive the critical number of channels which maintains super-criticality 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. Our results can be used to decide on the goodness of any channel rendezvous algorithm by computing the expected resultant connectivity.
Inhibitory effect of Lactobacillus plantarum was studied against Escherichia coli O157:H7 in minced beef , as well as the effect of some Spices ( Garlic , Cloves and Black Pepper ) was studied against this bacteria . Plate count method was used to estimate the viable cells of E. coli O157:H7 in the treated meat samples for incubation periods( 0 , 24 and 48) h. Results showed that Lactobacillus plantarum had inhibitory effect against E. coli O157:H7 , when reducing the number of cells after 24, 48 h., and reached to Zero after (24) h. As well as Spices in this study had inhibitory activity against E. coli O157:H7 .Garlic had
... Show MoreThis paper deals with the Kufis and basris agreements in Abo Al _ Barakat Al _ anbary’s
work “ Al- Insaf Fi Masael Al - Khilaf.It attempts to settle the disputes and find out the right
views.
The book presents the issnes that the two schools of Kufa and Basra dispute upon and try to
evaluate them so as to support the correct ones .The present researcher has noticed that the
author of the above work was not always right or accurate in picturing a number of issues as
disputable whereas they implicitly shared the same views .Accordingly ,this papor sheds light
on such cases and drew acadernic researchers, attention to the invalidity of Al –anbary’s
misjudged views.
Background: Although mammography is a powerful screening tool in detection of early breast cancer, it is imperfect, particularly for women with dense breast, which have a higher risk to develop cancer and decrease the sensitivity of mammogram, Automated breast ultrasound is a recently introduced ultrasonography technique, developed with the purpose to standardize breast ultrasonography and overcome some limitations of handheld ultrasound, this study aims to evaluate the diagnostic efficacy of Automated breast ultrasound and compare it with handheld ultrasound in the detection and characterization of breast lesions in women with dense breasts. Objectives: To evaluate the diagnostic efficacy of Automated breast ultrasound and compare
... Show MoreThis research tests the relationship linkage and effect between the Employees Empowerment Strategy and Organizational Innovation, The research problem is how to understand the Employees Empowerment Strategy role in the achievement Organizational Innovation in Diyala Public Company For Electrical Industrial. A questionnaire was used in data collection depending on the distribution of (32) forms to the research sample. Data were analyzed Using (SPSS)program. Using a number of statistical tools for tests the research hypothesis. The research found set of conclusions, one of the most important thinks was, that there is a linkage and impact relation between Employees Empowerment Strategy, its variables, and Organizational Innovation a
... Show MoreCrime is one of the most severe challenges facing States, and strives to find preventive measures, reduce its seriousness, and prevent them; due to developments, crimes have increased, and emerging new patterns of crimes, there is an urgent need to prevent crimes and reduce their effects. Modernizing its punitive system and diverting it to correctional rehabilitative justice to redress the prejudice caused by the crime and rehabilitate the convicted person by using alternative measures to short-term imprisonment. This research emphasizes alternative sanctions' value to minimizing short-term imprisonment penalties and their impact on societal security through several goals like, the negative consequences, justifications, and alternatives
... Show MoreThis research aims to identify the nutritional status of the individual's relationship to malnutrition using anthropometric measurements such as weight, height and impact on the values ??of the blood study sample included 200 male and 200 female of the inhabitants of the cities of Baghdad and Baquba reviewers Central Mahtbrat
Background: Most primary Health Care Centers (PHCCs) in Iraq have a referral system records; however, this mechanism does not function well because of the lack of other requirements for an efficient referral system.
Objective: To assess the practice & opinion of doctors in PHCs toward the referral system, and to determine the doctors in PHC's commitment to referral system instructions and guidelines.
Subjects and methods: A cross-sectional study with analytic elements was conducted in nine health directorates in Iraq, from the 1st October 2018 – 30th June 2019.One PHC was selected randomly form each sector in every governorate, A questionnaire was used to collect the required information.
... Show MoreThe article aims to study the liquidity that is required to be provided optimally and the profitability that is required to be achieved by the bank, and the impact of both of them on the value of the bank, and their effect of both liquidity and profitability on the value of the bank. Hence, the research problem emerged, which indicates the extent of the effect of liquidity and profitability on the value of the bank. The importance of the research stems from the main role that commercial banks play in the economy of a country. This requires the need to identify liquidity in a broad way and its most important components, and how to
... Show MoreHedera helix L. plant belongs to the family Araliaceae that provide a host of bioactive compounds (mainly saponins) of important biological activities, like spasmolytic, secretolytic, anti-inflammatory, and antibacterial activities. Literature survey revealed that there was no previously study concerning H. helix L. which is cultivated in Iraq, so we decided to carry out this study which include extraction, isolation, purification and identification of biologically important triterpenoid saponin hederacoside C from leaves of H. helix L. Extraction of hederacoside C was carried out using two methods; in the first method maceration was done with methanol 99.8% and in the second method soxhlet extraction wit
... Show MoreBackground: COVID-19 pandemic has influenced all life aspects; Dental staff, like other healthcare providers, may be exposed to COVID-19 as part of their work and its psychological impacts on healthcare workers should not be ignored
Objectives: To assess the anxiety, and fear from COVID-19 pandemic in dentists working in specialist dental centers: sample the Al-Resafa health directorate, and its relation between the anxiety, and COVID-19 fear with some of their demographic variables
Subjects and Methods: A cross-sectional study was conducted on 2nd Jan. to 14th Feb. 2021, by an electronic version of questionnaire through Google-form; the questionnaire was formed based on Mental-Health-American-Org
... Show More