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An Optimum Strategy for Producing Precise GPS Satellite Orbits using Double-Differenced Observations
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Both the double-differenced and zero-differenced GNSS positioning strategies have been widely used by the geodesists for different geodetic applications which are demanded for reliable and precise positions. A closer inspection of the requirements of these two GNSS positioning techniques, the zero-differenced positioning, which is known as Precise Point Positioning (PPP), has gained a special importance due to three main reasons. Firstly, the effective applications of PPP for geodetic purposes and precise applications depend entirely on the availability of the precise satellite products which consist of precise satellite orbital elements, precise satellite clock corrections, and Earth orientation parameters. Secondly, the PPP processing strategy has been employed by the International GNSS Service (IGS) and IGS analysis centers to evaluate their products in terms of homogeneity and precision over a long period of time. Thirdly, the precise positions, which are determined using PPP technique, and are referenced directly to the geodetic reference frame of the satellite orbital parameters. Thus, the definition of the geodetic datum of the site coordinates using different strategies plays an enormous role in the process of generation satellite orbital parameters which have to be compatible with the corresponding satellite clock corrections and the Earth orientation parameters. This study focuses on producing uninterrupted series of satellite orbit and clock products using different criteria and assesses these products using PPP. The double-difference processing technique was used to achieve the goal of this study by Bernese GPS software version 5.0. Twenty-two globally distributed IGS stations were selected to run PPP based on the generated products and then compare the results with corresponding PPP results which were created based on the IGS rapid products. The comparison pointed to a significant improvement in the generated precise products which have considerably increased the precision of positions. What is more, this study stated that there is an observable agreement between the horizontal positions accuracies which are generated using different techniques for modeling the reference frame.

 

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Publication Date
Fri Dec 22 2006
Journal Name
Journal Of Planner And Development
Abu Ghraib Urban Growth An Analytical Study in General Characteristics
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The Results Of Interest In Capitals And Major Cities Have Become Major Attraction Centers For People In Rural Areas And Different Regions, Especially With The Concentration Of Industrial And Commercial Establishments And Public Services, Which Helped To Find The Wide Differences Between Them. Recently, The Trend To Develop Small Urban Centers In Rural Back Areas Great And Serious Attempt To Reduce Inflation. The Suburb Of Abu Ghraib Is One Of The Important Suburbs Near The City Of Baghdad And Through The Study Of The Reality Of The Suburb Shows That The Outcome Of Its Career And Urban Development Lies In Its Mutual Relationship With The City Of The Mother In The Light Of Considerations And Measures Of The Most Important Accessibility And

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Publication Date
Thu Oct 18 2018
Journal Name
Applied Bionics And Biomechanics
Active Impedance Control of Bioinspired Motion Robotic Manipulators: An Overview
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There are two main categories of force control schemes: hybrid position-force control and impedance control. However, the former does not take into account the dynamic interaction between the robot’s end effector and the environment. In contrast, impedance control includes regulation and stabilization of robot motion by creating a mathematical relationship between the interaction forces and the reference trajectories. It involves an energetic pair of a flow and an effort, instead of controlling a single position or a force. A mass-spring-damper impedance filter is generally used for safe interaction purposes. Tuning the parameters of the impedance filter is important and, if an unsuitable strategy is used, this can lead to unstabl

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Publication Date
Mon Jul 01 2019
Journal Name
Journal Of Physics: Conference Series
Cu (In, Ga) Se2 an absorber layer of photovoltaic devices
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CIGS nanoink has synthesized from molecular precursors of CuCl, InCl3, GaCl3 and Se metal heat up 240 °C for a half hour in N2-atmosphere to form CIGS nanoink, and then deposited onto substrates of soda-lime glass (SLG). This work focused on CIGS nanocrystals, indicates their synthesis and applications in photovoltaic devices (PVs) as an active light absorber layers. in this work, using spin-coating to deposit CIGS layers (75 mg/ml and 500 nm thickness), without selenization at high temperatures, were obtained up to 1.398 % power conversion efficiency (PCE) at AM 1.5 solar illumination. Structural formations of CIGS chalcopyrite structure were studied by using x ray diffraction XRD. The morphology and composition of CIGS were studied using

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Publication Date
Thu Aug 17 2023
Journal Name
Journal Of Thermoplastic Composite Materials
Fabrication and characterization of PEKK nanocomposites: An in vitro study
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Although the number of implants has increased gradually and consistently over the years to around one million per year globally, there is still far more potential for advancement in the field of dental implantology which is typically growing quickly. This study investigates the effect of nanofiller reinforcement high-performance polymer matrix to enhance mechanical and physical characteristics. Calcium silicate (CS)/Polyetherketoneketone (PEKK) biomedical composite (G0 as a control group) is reinforced with different weight percentages (G1-G4) of tellurium dioxide nanoparticles (TeO2NPs) ( n = 5). This research uses ethanol as a binder for mixing various weight percentages (wt%) of TeO2NPs w

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Publication Date
Tue Jun 15 2021
Journal Name
Arab World English Journal
Impoliteness and Threat Responses in an Iraqi-Kurdish EFL Context
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This study shows impoliteness as a form of face-threatening that can be intentionally caused by verbal threats in a particular setting. It investigates: what strategies and mitigators do Iraqi-Kurdish English as a foreign language (EFL) learners use in situations of threat responses? The present investigation paper aims to examine impoliteness strategies and mitigators by these learners when they respond to threatening situations in their context. Thus, it fills a gap in pragmatics literature by investigating the reactions to threats in an Iraqi-Kurdish EFL context. To this end, 50 participants have participated in this study. An open-ended questionnaire in the form of a Discourse Completion Task (DCT) is used to elicit responses fr

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Publication Date
Thu Oct 09 2025
Journal Name
Journal Of Baghdad College Of Dentistry
Radiopacity of modified microhybrid composite resin:(An in vitro study)
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Background: The aim of this study was to measure the radiopacity (RO) of modified microhybrid composite resins by adding 2 types of nanofillers (Zinc Oxide and Calcium Carbonate) in two concentrations 3% and 5% and comparing them to unmodified microhybrid composite resins and to nanofilled composite resin. Materials and Methods: Two types of composite resin were used (Microhybrid composite MH Quadrent anterior shine and Nanofilled composite resin Filtek Z350 XT), for each tested group five disk-shaped specimens (1-mm-thick and 15 mm diameter) were fabricated. The material samples were radiographed together with the aluminum step wedge. The density of the specimens was determined with a transmission densitometer and was expressed in term of

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Publication Date
Tue Jan 29 2019
Journal Name
Journal Of The College Of Education For Women
The Environmental Education and her role to protect an Environment
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Environmental education is considered as process of getting Humans in communication with this environment and all its various resources. such process requires acquiring knowledge about the environment that com help humans understand their correlative relations with the environmental elements on one hand and among the environmental elements themselves on the other . Besides, such a process requires developing human skills that help them participate in developing environmental circumstances. Therefore environmental education is responsible for perspective and cultural development that governs human behavior. Regarding their environment and stimulating tendencies and interests towards the environment , let alone helping humans acquire the c

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Publication Date
Wed Dec 30 2015
Journal Name
Mathematical Theory And Modeling
On the stability of an SIS epidemic model involving treatment
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The objective of this paper is to study the stability of SIS epidemic model involving treatment. Two types of such eco-epidemiological models are introduced and analyzed. Boundedness of the system is established. The local and global dynamical behaviors are performed. The conditions of persistence of the models are derived.

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Publication Date
Mon Jun 30 2008
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
Biotreatment of Oil Wells Drilling Waste in an Agricultural Soil
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One of the most important environmental issues is the responsible effective and economic treatment of drilling waste especially oily waste.
In this research two fungal isolates named Pleurotus ostreatus and Trichoderma harzianum were chosen for the first time to treat biologically the oily drilled cuttings contaminated with diesel which resulted from drilling oil wells use oil based muds (OBMs).
The results showed that the fungi under study utilized the hydrocarbon of contaminated soil as a source of nutrient and growth and that both fungi can be considered hydrocarbon degrading microorganisms. The used biotreatment is cost effective process since most of the materials used in the cultivation and growth of the present fungi were av

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Publication Date
Thu Dec 28 2023
Journal Name
Al–bahith Al–a'alami
Digital Interactive Elements in The Twitter Platform: An Analytical Study
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The primary issue addressed in this research revolves around identifying the interactive elements provided by the Twitter platform and understanding their utilization by digital newspapers with official accounts. These newspapers broadcast content in line with their policies. This study is classified within descriptive research that employed a survey method and content analysis tool. The methodology relies on the "how was it said?" approach to categorize the analysis. The research yielded the following results:
Twitter utilized numerous interactive elements for disseminating tweets, which include "text, branching links, hashtags, digital images, digital videos, digital audio, and digital polls." However, thes

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