The study of entry and reentry dynamics for space vehicles is very important, particularly for manned vehicles and vehicles which is carry important devices and which can be used again. There are three types for entry dynamic, ballistics entry, glide entry and skip entry. The skip entry is used in this work for describing entry dynamics and determining trajectory. The inertia coordinate system is used to derive equations of motion and determines initial condition for skip entry. The velocity and drag force for entry vehicle, where generate it during entry into earth’s atmosphere are calculated in this work. Also the deceleration during descending and determining entry angles, velocities ratio and altitude ratio have been studied. The circular velocity and super circular velocity are used in this work as initial values. From results we noted the skip entry type has longer flight time compared with other types, and the velocity vehicle is lower at high layer for earth atmosphere, where the density of air is very low. Therefore the skip entry is suitable for space shuttle during entry from space
<p><span>A Botnet is one of many attacks that can execute malicious tasks and develop continuously. Therefore, current research introduces a comparison framework, called BotDetectorFW, with classification and complexity improvements for the detection of Botnet attack using CICIDS2017 dataset. It is a free online dataset consist of several attacks with high-dimensions features. The process of feature selection is a significant step to obtain the least features by eliminating irrelated features and consequently reduces the detection time. This process implemented inside BotDetectorFW using two steps; data clustering and five distance measure formulas (cosine, dice, driver & kroeber, overlap, and pearson correlation
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This paper presents a computer simulation model of a thermally activated roof (TAR) to cool a room using cool water from a wet cooling tower. Modeling was achieved using a simplified 1-D resistance-capacitance thermal network (RC model) for an infinite slab. Heat transfer from the cooling pipe network was treated as 2-D heat flow. Only a limited number of nodes were required to obtain reliable results. The use of 6th order RC-thermal model produced a set of ordinary differential equations that were solved using MATLAB - R2012a. The computer program was written to cover all possible initial conditions, material properties, TAR system geometry and hourly solar radiation. The cool water supply was considered time
... Show MoreThis research will deal in a simple way with the concept of urban expansion and taking the decision to sign the spatial signature of residential investment projects in order to reach through them in a real way to the extent of the proportionality of the decision taken, in light of the fulfillment of the conditions that must be met in the matter of making the decision of the spatial signature of the residential investment project and the extent of commitment to them, in which the conditions are: (Ease of access to services and transportation, adequacy of services, commitment to urban land uses) when establishing the investment project represented by the Al-Ayad residential project in the Hittin neighborhood of Al
... Show MoreBackground: The aim of this in vitro study was to evaluate and compare the microleakage between Vertise Flow T M composite material and other conventional (Filtek Z250, riva light cure and SDR) composite materials when restoring CII mesial box only cavity at gingival margin through die penetration test Materials and methods: Forty maxillary first premolars were prepared with class II box design only cavities. Samples were divided into four groups of ten teeth according to material used: group I (FiltekZ250 only). Group II (SDR+FiltekZ250). Group III (Vertise Flow +FiltekZ250). Group IV (Riva light cure+ FiltekZ250). After 24 hrs. immersion in 2% in methylene blue, samples were sectioned and micro leakage was estimated. Results: None of the
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Abstract: The increased interest in developing new photonic devices that can support high data rates, high sensitivity and fast processing capabilities for all optical communications, motivates a pre stage pulse compressor research. The pre-stage research was based on cascading single mode fiber and polarization maintaining fiber to get pulse compression with compression factor of 1.105. The demand for obtaining more précised photonic devices; this work experimentally studied the behavior of Polarization maintaining fiber PMF that is sandwiched between two cascaded singe mode fiber SMF and fiber Bragg gratings FBG. Therefore; the introduced interferometer performed hybrid interference of both Mach-Zehnder
... Show MoreBackground: Obesity and dental caries are multifactorial diseases related to poor eating habits and show a close relationship with the sociodemographic characteristics of individuals presenting these diseases. This research aimed to investigate the severity of dental caries among group of obese boys aged 12 year in relation to salivary interleukin-6 (IL-6) and C-reactive protein (CRP) of unstimulated whole saliva in comparison with normal weighted boys of the same age. Materials and Methods: The study group included 40 obese boys, with an age of 12 year. The control group included 40 normal weighted boys of the same age. The total sample involved for nutritional status assessment using Body Mass Index specific for age and gender according t
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The objective of this study is to ascertain the pivotal role of headlines in captivating viewers' attention toward news bulletins. Additionally, it aims to explore the factors that contribute to the correlation between headlines and the public's acceptance or rejection of the meticulously crafted news articles presented through these bulletins. The study delves into the mechanisms employed in writing and editing headlines, focusing on their style, expert composition, and intriguing nature. These factors inevitably influence the level of acceptance and engagement of the viewership with the news articles disseminated via the news bulletins. Employing a descriptive methodology, the researcher distributed 200 question
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The scope of the world of translation is an area filled with different types of translations, whether translations of scientific, social, political or economic in addition to the other types are endless, but the translation problematic grammatical that may confront us if we proceed to translate any subject are important issues that must Translator whether translators or interpreters that puts it into consideration and attaches great importance to the translation is very clear and without any ambiguity. One of these forms of grammatical task is to translate the relative pronoun (que) from Spanish into Arabic language, which revolves around the subject of this research.
The relative pron
... Show MoreAbstract: In the present work, the heat transfer of Nano Aluminum Oxide -NAO- has been studied practically to define the appropriate insulation conditions. This study focuses on finding of the amount of heat transfer through a glass substrate that is coated with nanoalumina doped on PMMA matrix. The optical and thermal properties were systematically investigated. The density of heat flow rate, was calculated in the range values (240-260) W/m2 while the optimum values confine between (250-260) W/m2 at temp. (25-35)Co. The results showed that the thermal insulation of the sample was significantly enhanced at temp. (30-50)Co. The simulated net heat transfer through window decreased linearly with incr
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This study aims to identify the level of patients’ satisfaction among a sample of hospitalized patients in the targeted hospital (Al-Kindy Teaching Hospital, and Al-Yarmook Teaching Hospital). Moreover, this study highlights the reality of services for patients, especially in the targeted governmental teaching hospitals. The Patient Satisfaction with Nursing Care (PSNCS) has been measured in these hospitals through the revised scale by Tang et al, (2013).This scale includes four major domains; Health Information (5 items), Influencing Support (4 items), Decision Control (4 items), Specialized Technical Competence (7 items). The method of surveying patients’ opinions about the degree
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