The paper presents an investigation to the flutter speed of composite wing for different ply orientation. Structurally the composite wing was idealized as a composite beam load carrying structure. Theodorsen’s expression was used to get the 2- dimension unsteady lifting force and pitching moment in the limit of incompressible flow and subsonic speed which were integrated over the wing span. A free vibration analysis was first carried out to get the natural frequencies and mode shapes .The velocity-damping (V-g) method was used to calculate the flutter speed and the flutter frequency. A wing of unmanned aerial vehicle was manufactured from woven glass and polyester resin where the flutter speed was calculated experimentally by the wind tunnel test .The flutter speed was calculated analytically for different ply orientation, it is found that the increasing in torsion rigidity leads to increase in the flutter speed, the fiber combination with high torsion rigidity and relatively low coupling rigidity give higher flutter speed.
The effect of cognitive trips via the Internet (web quest) accompanying practical lessons in learning some basic handball skills for female students
The research aims to demonstrate the impact of tax techniques on the quality of services provided to income taxpayers by studying the correlational and influencing relationships between the exploited variable (tax techniques) and the dependent variable (the quality of services provided to income taxpayers), and in line with the research objectives, the main hypothesis of the research was formulated (there is a relationship Significance between tax techniques and the quality of services provided to income taxpayers) a number of sub-hypotheses emerged from this hypothesis that were stated in the research methodology, and a number of conclusions were reached, the most important of which were (through the use of the correlation coeff
... Show MoreIncorporating waste byproducts into concrete is an innovative and promising way to minimize the environmental impact of waste material while maintaining and/or improving concrete’s mechanical characteristics and strength. The proper application of sawdust as a pozzolan in the building industry remains a significant challenge. Consequently, this study conducted an experimental evaluation of sawdust as a fill material. In particular, sawdust as a fine aggregate in concrete offers a realistic structural and economical possibility for the construction of lightweight structural systems. Failure under four-point loads was investigated for six concrete-filled steel tube (CFST) specimens. The results indicated that recycled lightweight co
... Show MoreThe Mesopotamian marshlands faced a massive destruction from many years and this lead to effect to ecosystem. In this study a survey was made on the physical chemical and heavy metals characteristics and microbiological analysis of AL Chibaish marsh during the two months. Water analyses revealed unacceptable values for almost all physiochemical and biological properties, according to WHO standard limits for drinking water. Almost all major ions and heavy metal concentrations in water showed a distinct decreasing trend at the marsh outlet station compared to other stations. In general, major and minor ions, as well as heavy metals exhibit higher concentrations in location 1 than in location 3. The concentrations of heavy metals in water show
... Show Moret
The research deals with the statement of the importance of unanimous in Islamic Sharia in terms of being the third source of Islamic legislation after the Holy Qur’an and the Sunnah of the Prophet, and the extent of interest of the scholars of interpretation in it, and those who took great interest in mentioning what was agreed upon in every site that necessitated mentioning its issues within, or mentioning an event that has encountered an unanimous, and in various sciences, to extract and extrapolate Sharia rules when these rules are lost in the texts, because it is based on them and derived from them. Among these distinguished scholars is Muhammad bin Jarir al-Tabari. Besides, the research discusses in
... Show MoreIn this study, dependence of gamma-ray absorption coefficient on the size of Pb particle size ranging from 200µm up to 2.5mm, using different weights of each particle size. The results show that gamma-ray attenuation coefficient is inversely proportional with the size of Pb particle size due to the reduction of the spaces between the lead particles.
Objectives. This study aimed to evaluate the impact of nonnutritive sucking habits on the presence of oral Escherichia coli. Methods. One hundred and twenty children aged 3–5 years old were enrolled in the present case-control study, as follows: 60 children with continuous pacifier and thumb sucking habits (study group) and 60 children without any sucking habits (control group). The children in the two groups were matched in terms of age and gender. Information was gathered from the parents concerning their children using a special sheet. Sterile swabs were taken from both groups and cultured on agar plates. Then, they were subjected to further biochemical tests to identify E. coli species. The mean of the E. coli count was determ
... Show MoreRecently, interest in the use of projectiles in research on recycling waste materials for construction applications has grown. Using recycled materials for the construction of asphalt concrete pavement, in the meantime, has become a topic of research due to its significant benefits, such as cost savings and reduced environmental impacts. This study reports on comprehensive experimental research conducted using a typical mechanical milling waste, iron filing waste (IFW), as an alternative fine aggregate for warm mix asphalt (WMA) for pavement wearing surface applications. A type of IFW from a local machine workshop was used to replace the conventional fine aggregate, fine natural sand (FNS), at percentages of 25%, 50% 75%, and 100% b
... Show MoreKombucha(Khubdat Humza) is composed of yeast and acetic acid bacteria especially, Acetobacter xylinum which forms a cellulose pellicle on tea broth. Kombucha(Khubdat Humza) produces bacterial cellulose pellicles, with unique purity and fine structure. It can be used in many forms, such as an emulsifier, stabilizer, dispersing agent, thickener and gelling agent but these are generally subsidiary to its most important use of holding on to water. Recently, bacterial cellulose is used in many special applications such as a scaffold for tissue engineering of cartilages and blood vessels, also for artificial skin for temporary covering of wounds, as well as its used in the clothing industry. The yield of cellulose produced were investiga
... Show More