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HF Wave Propagation Prediction Based On Passive Oblique Ionosonde
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High frequency (HF) communications have an important role in long distances wireless communications. This frequency band is more important than VHF and UHF, as HF frequencies can cut longer distance with a single hopping. It has a low operation cost because it offers over-the-horizon communications without repeaters, therefore it can be used as a backup for satellite communications in emergency conditions. One of the main problems in HF communications is the prediction of the propagation direction and the frequency of optimum transmission (FOT) that must be used at a certain time. This paper introduces a new technique based on Oblique Ionosonde Station (OIS) to overcome this problem with a low cost and an easier way. This technique uses the international shortwave radio stations and the global beacons as the OIS transmitter and a normal HF receiver as the OIS receiver to verify the direction of propagation and the FOT. In addition, the critical frequency for F2 layer (fof2) was estimated in this paper for Iraq experimentally. The proposed technique was tested practically, and FOT range between Baghdad and other remote stations was estimated successfully using a radio receiver from Kenwood model R 1000 with a long wire antenna as a passive OIS system receiver.

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Publication Date
Sun Jan 01 2017
Journal Name
Journal Of Engineering
EFFECT OF PVD AND VACUUM PRESSURE ON SATURATED-UNSATURATED SOFT SOILS
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    Soft clays are generally sediments deposited by rivers, seas, or lakes. These soils are fine-grained plastic soils with appreciable clay content and are characterized by high compressibility and low shear strength. To deal with soft soil problems there is more than one method that can be used such as soil replacement, preloading, stone column, sand drains, lime stabilization and Prefabricated Vertical Drains, PVDs. A numerical modeling of PVD with vacuum pressure was analyzed to investigate the effect of this technique on the consolidation behavior of fully and different depths of partially saturated soft soils.  Laboratory experiments were also conducted by using a specially-designed large consol

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Publication Date
Mon Apr 01 2013
Journal Name
International Journal Of Mathematical Archive
ON GROUPS OF GEOMETRIC FIGURES
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In this paper we introduce the basic of definitions of groups for geometric figures; we describe some of geometric figures by using the properties of groups. The classification of some geometric figures by using the properties of some algebraic structures.

Publication Date
Mon Mar 01 2021
Journal Name
Journal Of Physics: Conference Series
On Quasi-Small Prime Modules
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Abstract<p>Let R be a commutative ring with identity, and W be a unital (left) R-module. In this paper we introduce and study the concept of a quasi-small prime modules as generalization of small prime modules.</p>
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Publication Date
Sun Jan 01 2023
Journal Name
Journal Of Discrete Mathematical Sciences &amp; Cryptography
On β*-supra topological spaces
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In this paper, a new type of supra closed sets is introduced which we called supra β*-closed sets in a supra topological space. A new set of separation axioms is defined, and its many properties are examined. The relationships between supra β*-Ti –spaces (i = 0, 1, 2)   are studied and shown with instances. Additionally, new varieties of supra β*-continuous maps have been taken into consideration based on the supra β*-open sets theory. 

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Publication Date
Sun Oct 03 2010
Journal Name
Baghdad Science Journal
On Semi-p-Compact Space
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Publication Date
Tue May 20 2008
Journal Name
Journal Of Planner And Development
Notes on regional development policies
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the regional and spatial dimension of development planning must be taken as a point of departure to the mutual of the spatial structure of the economy , development strategy and policies applied 'therein such as the location principles and regional development coordination of the territorial problems with the national development planning and timing of regional vis-a-vis national development plan_. Certain balance and integration is of sound necessity' between national _regional and local development objectives through which the national development strategy should have to represent the guidelines of the local development aspirations and goals. The economic development exerts an impact on the spatial evolution, being itself subje

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Publication Date
Wed May 08 2013
Journal Name
Iraqi Journal Of Science
On D- Compact Topological Groups
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In the present paper, we have introduced some new definitions On D- compact topological group and D-L. compact topological group for the compactification in topological spaces and groups, we obtain some results related to D- compact topological group and D-L. compact topological group.

Publication Date
Sat Mar 06 2010
Journal Name
J. Of University Of Anbar For Pure Science
Some Results on Epiform Modules
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The concept of epiform modules is a dual of the notion of monoform modules. In this work we give some properties of this class of modules. Also, we give conditions under which every hollow (copolyform) module is epiform.

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Publication Date
Sat Oct 01 2022
Journal Name
University Of Baghdad, College Of Education For Pure Sciences / Ibn Al-haitham, Department Of Mathematics
On Fibrewise Fuzzy Topological Spaces
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The aim of this research is to study some types of fibrewise fuzzy topological spaces. The six major goals are explored in this thesis. The very first goal, introduce and study the notions types of fibrewise topological spaces, namely fibrewise fuzzy j-topological spaces, Also, we introduce the concepts of fibrewise j-closed fuzzy topological spaces, fibrewise j-open fuzzy topological spaces, fibrewise locally sliceable fuzzy j-topological spaces and fibrewise locally sectionable fuzzy j-topological spaces. Furthermore, we state and prove several Theorems concerning these concepts, where j={δ,θ,α,p,s,b,β} The second goal is to introduce weak and strong forms of fibrewise fuzzy ω-topological spaces, namely the fibrewise fuz

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Publication Date
Thu Apr 08 2021
Journal Name
Journal Of Interdisciplinary Mathematics
On regular δ-semi.open space
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It is shown that if a subset of a topological space (χ, τ) is δ-semi.closed, then it is semi.closed. By use this fact, we introduce the concept regularity of a topological space (χ, τ) via δ-semi.open sets. Many properties and results were investigated and studied. In addition we study some maps that preserve the δ-semi.regularity of spaces.

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