In this study, the dynamic modeling and step input tracking control of single flexible link is studied. The Lagrange-assumed modes approach is applied to get the dynamic model of a planner single link manipulator. A Step input tracking controller is suggested by utilizing the hybrid controller approach to overcome the problem of vibration of tip position through motion which is a characteristic of the flexible link system. The first controller is a modified version of the proportional-derivative (PD) rigid controller to track the hub position while sliding mode (SM) control is used for vibration damping. Also, a second controller (a fuzzy logic based proportional-integral plus derivative (PI+D) control scheme) is developed for both vibration damping and hub position tracking. A comparison is made between the performances of these two controllers. The Hybrid controller with PD and SM shows better tracking behavior than obtained from the suggested fuzzy (PI+D)2 controller for a single link flexible manipulator.
Objective: To conduct a standardized method for cavity preparation on the palatal surface of rat maxillary molars and to introduce a standardized method for tooth correct alignment within the specimen during the wax embedding procedure to better detect cavity position within the examined slides. Materials and methods: Six male Wistar rats, aged 4-6 weeks, were used. The maxillary molars of three animals were sectioned in the frontal plane to identify the thickness of hard tissue on the palatal surface of the first molar which was (250-300µm). The end-cutting bur (with a cutting head diameter of 0.2mm) was suitable for preparing a dentinal cavity (70-80µm) depth. Cavity preparation was then performed using the same bur on the tooth surf
... Show MoreAbstract The research investigates in detail the fascinating story of its title character, which may work as an allegory for Africa itself in its past. Ama Ata Aidoo is miscellaneous writers who wrote in different literary genre like drama , short stories novel and , poetry and criticism . She is also an active feminist. Aidoo is against the colonial practice and its influence on African minds. Aidoo's play Anowa confronts painful issues in Africa's past, mostly those of the slave trade. She goes further to tackle issues of patriarchal domination and African feminism, like the relationships between individuals and society, women and motherhood, men and women, husbands and wives, mothers and daughters, and above all the future invasion
... Show MoreThis review is concluded of 8-Hydroxyquinline (8HQ) compound and derivatives which has a very significant interests with a strong fluorescence , furthermore the relationship between divalent metal ions and characteristic of chelating . In the same way coordinated features have increase of its organic action and inorganic behavior by giving many samples of compounds which are a good chelating agents ligands with more capable of forming very stable complexes.Therefore, the role of (8HQ) is not limited on complexes only but its applications in different fields so this review will focus on demonstration preparation methods and properties of (8HQ) derivatives with their complexes and applications, hopefully that we will cover a part of scientifi
... Show MoreWar as a human phenomenon, has its own literature. Poetry is a major genre in this literature. This paper is an attempt to investigate and analyse some stylistic features in two selected, English and Arabic, war poems. These poems share the same theme.Both promote the principle of sacrificing one’s own life for the sake of homeland. This paper limits itself to analyse, thecontent words, tenses, semantic grouping of vocabulary and foregrounding in the two poems. The areas of analysis show great similarities in distributing the general content words (nouns, verbs, adjectives, and adverbs). In the analysis of the semantic areas of each content word, these poems reveal some similarities and some differences in their frequency rates.
... Show MoreThis study explores the semiotic aspects of American slang, specifically focusing on the phenomenon of reduplicative expressions in informal speech. Despite the extensive research on American slang, limited attention has been given to the cultural and mythical meanings embedded within reduplicative expressions. To address this gap, the study investigates how these expressions convey denotative, connotative, and mythical meanings within casual American discourse. The objectives of the study include: 1. To what extent does Barthes’ semiotic model hold potential for application in this study? 2. How are reduplicative slang expressions widely used in everyday American life? 3. To what extent do qualitative and quantitative methods hav
... Show MoreThis study includes a detailed morphological description of Cosmina baghdadensis sp. nov.
from Iraq.
Many characters are used in identification especially chaetotaxy and male genetalia.
Locality, host plant, and data of collection were given.