The importance of vibrations in rotating rotors in engineering applications has been examined, as has the best approach to interpreting vibration data. The most extensively used analytical approaches for rotating shaft vibration analysis have been investigated. In this research, a detailed study was made of the Rayleigh and Dunkerley methods due to their importance in the special calculations to find the amplitude of vibrations in the rotation system. The multi-node method was used to calculate both Dunkerley's and Rayleigh's methods. An experimental platform was built to study the vibrations that occur in the rotating shafts, and the results were compared with theoretical calculations and with different distances of the bearings. It proved that there is very little error between the experimental and theoretical results. The vibration signal from the sensors was analyzed using the LABVIEW program. Rayleigh's method was compared to the exact method, and it was considered the most accurate method. It was found that it made very little difference, up to about 0.06%. As for the Dunkerley method, the difference between it and the proper method is about 4%, which is acceptable. Then a comparison was made between Rayleigh's and Dunkerley's methods, and it was found that Dunkerley's method is the most appropriate in the calculations.
With the development of communication technologies, the use of wireless systems in biomedical implanted devices has become very useful. Bio-implantable devices are electronic devices which are used for treatment and monitoring brain implants, pacemakers, cochlear implants, retinal implants and so on. The inductive coupling link is used to transmit power and data between the primary and secondary sides of the biomedical implanted system, in which efficient power amplifier is very much needed to ensure the best data transmission rates and low power losses. However, the efficiency of the implanted devices depends on the circuit design, controller, load variation, changes of radio frequency coil’s mutual displacement and coupling coef
... Show MoreThe theory of general topology view for continuous mappings is general version and is applied for topological graph theory. Separation axioms can be regard as tools for distinguishing objects in information systems. Rough theory is one of map the topology to uncertainty. The aim of this work is to presented graph, continuity, separation properties and rough set to put a new approaches for uncertainty. For the introduce of various levels of approximations, we introduce several levels of continuity and separation axioms on graphs in Gm-closure approximation spaces.
Background: Gingivitis is one of the most common and widely spread oral diseases in adolescents after dental caries occur in both developed and developing countries. Dental plaque is the main etiological factor of gingivitis. Another oral problem is enamel defect. The aim of this study was to estimate the oral hygiene (dental plaque), and determine the prevalence and severity of gingivitis and enamel defects among 16-17 years old secondary school female students in urban areas of Kirkuk city/Iraq. Materials and methods: A representative sample included in this study consisted of 750 secondary school female students distributed into 387 for the age sixteen and 363 for the age seventeen, they were selected randomly from different female secon
... Show MoreBackground: Water-pipe can be defined as a single or multi stemmed device that used to vaporize and smoke flavored tobacco whose smoke is passed via water vase before inhalation. Water-pipe smokers are at risk of exposure to many toxic chemicals that are not filtered by water, as well as risk of infectious diseases when the mouth piece of the water-pipe is shared. This study was carried out to investigate the effect of water pipe on the oral health. Materials and Methods: Sixty persons were included in this study aged between 22 and 23 years. Forty persons were coffee shop workers for at least five years, half of them were water-pipe smokers (active smokers) and the other weren’t smokers (passive smoker), the last group was the co
... Show MoreBackground: The scarce literature regarding oral hygiene attitude and periodontal awareness in Iraqi adults warranted the conduction of this study in order to provide a public profile and a baseline data for further researches. Aims of the study: assessing the oral hygiene attitude and periodontal awareness in a sample of Iraqi adults. Materials and Methods: Self-administered questionnaires were distributed to 500 adults. Results: Out of the 500 questionnaires distributed, 482 were included in the study.92% of the sample practiced tooth brushing, 69% out of them reported a daily brushing pattern with variable frequency,69% of the sample did not receive oral hygiene education from any source ,more than half of the sample 60 % used the hori
... Show MoreThis paper investigates the interaction between fiscal and monetary policy in Iraq after 2003 using the prisoner’s dilemma.The paper aims to determine the best form of coordination between these policies to achieve their goals; payoff matrix for both policies was constructed. To achieve the purpose, the quantitative approach was applied using several methods, including regression, building payoff matrices and decision analysis using a number of software.The results of the monetary policy payment function show that inflation rate has an inverse relationship with the auctions of selling foreign currency and a positive relationship with the government’s activity, while the fiscal policy function shows that real growth is positively
... Show MoreThe gravity method is a measurement of relatively noticeable variations in the Earth’s gravitational field caused by lateral variations in rock's density. In the current research, a new technique is applied on the previous Bouguer map of gravity surveys (conducted from 1940–1950) of the last century, by selecting certain areas in the South-Western desert of Iraqi-territory within the provinces' administrative boundary of Najaf and Anbar. Depending on the theory of gravity inversion where gravity values could be reflected to density-contrast variations with the depths; so, gravity data inversion can be utilized to calculate the models of density and velocity from four selected depth-slices 9.63 Km, 1.1 Km, 0.682 Km and 0.407 Km.
... Show MoreBackground: Background: Diabetes mellitus is a life-threatening disease. Global prevalence of diabetes mellitus is increasing rapidly providing a worrying indication and major threat to global health unless interventions are created through community awareness and knowledge regarding different aspect of DM.
Aims: To assess the level of awareness regarding diabetes risk factors, prevention and management among community members in Baqubah city and to identify any association between awareness level and some variables.
Methods: Across sectional study was carried out from the 1st of January - 30th of November 2019 in all primary health care centers (six centers) in center of Baqubah city. A convenien
... Show MoreThe aim of this research is to examine the relationship between entrepreneurial mindset and aspiration and small business performance Baghdad, Iraq. This study proposed a quantitative analysis in which entrepreneurial mindset and aspiration is a critical success factor of small business in Iraq. The method employed in the collection of data was by the means of self-administered questionnaire which was filled and completed by small business owners randomly selected from a sampling frame of registered small businesses. The questionnaire was adapted from the study of Davis, Halls & Mayer (2015) and Abdel-Maksoud, Asada & Nakagawa (2008) which was used to measure entrepreneurial mindset and aspiration using a ten items scale and small business
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