Back ground: Several devices with different physical bases have been developed for the clinical measurement of corneal thickness, they classified into 4 categories: Scheimpflug photography based, Slit –Scanning topography, optical coherence tomography (OCT) based and ultrasound (US) based.Objective:To evaluatethe precision of the new Scheimpflug –Placido disc corneal topography in measurement of corneal thickness and to compare the measured values with that obtained by US pachymetry.Methods: Setting of this study is Lasik center in Eye Specialty Private Hospital. Baghdad. Iraq.Eyes of healthy subjects were examined with the Sirius topography.3 consecutive measurements of central (CCT)and thinnest (TCT) corneal thicknesses were obtainedand the measurements repeated within 1 week. The within –subject standard deviation (Sw),test-retest repeatability ,coefficient of variation (CoV),and interclass correlation coefficient (ICC) were calculated to evaluate intra session repeatability and intersession reproducibility. For US pachymetry (Tomey-SP 100) only CCT was measured. Comparison ofthe measurements that obtained by the 2 devices done by paired t-test.Results: The topography provides high intrasession repeatability with test-retest and CoV close to 6μm and0.4%, respectively for both CCT and TCT. The inter session reproducibility also high with test-retest and CoV close to 8μm and 0.5%, respectively.ICC was higher than 0.97 for repeatability and reproducibility . Anarrow 95% limit of agreement was found between the pachymetry obtained by topography and US pachymetry measurements.Conclusions :The topography has been used showed high intrasession repeatability and intersession reproducibility of CCT and TCT measurements in healthy eyes .Absence of statistically significant differences suggest that the topography -TCT and the US pachymetry - CCT can be used interchangeably in subject with normal cornea.Financial Disclosure: No financial or proprietary interest in any material or method mentioned.
In this paper, we study, in details the derivation of the variational formulation corresponding to functional with deviating arguments corresponding to movable boundaries. Natural or transversility conditions are also derived, as well as, the Eulers equation. Example has been taken to explain how to apply natural boundary conditions to find extremal of this functional.
Abstract: In this research, nanofibers have been prepared by using an electrospinning method. Three types of polymer (PVA, VC, PMMA) have been used with different concentration. The applied voltage and the gap length were changed. It was observed that VC is the best polymer than the other types of polymers.
Using fiber-reinforced polymer (FRP) could effectively improve the strength and endurance of reinforced concrete (RC) constructions. This study evaluated the flexural behavior of one-way concrete slabs with openings reinforced with glass fiber-reinforced polymers (GFRP) bars. It strengthened using carbon fiber-reinforced polymer (CFRP) sheets around the openings. The experimental program of this study is adopted by casting and testing four one-way concrete slabs with dimensions of (150*750*2650) mm. These slabs are divided into two groups based on whether they were strengthened or un-strengthened. For each group, two different openings (either one rectangular or two square) measured 250*500 mm and 250*250 mm, respective
... Show MoreThe present investigation focuses on the response of simply supported reinforced concrete rectangular-section beams with multiple openings of different sizes, numbers, and geometrical configurations. The advantages of the reinforcement concrete beams with multiple opening are mainly, practical benefit including decreasing the floor heights due to passage of the utilities through the beam rather than the passage beneath it, and constructional benefit that includes the reduction of the self-weight of structure resulting due to the reduction of the dead load that achieves economic design. To optimize beam self-weight with its ultimate resistance capacity, ten reinforced concrete beams having a length, width, and depth of 2700, 100, and
... Show MoreThe solar eclipse occurs at short time before the crescent birth moment when the moon near any one of moon orbit nodes It is important to determine the synchronic month which is used to find Higree date. The 'rules' of eclipses are:
Y= ± 0.997 of Earth radius , the solar eclipse is central and 0.997 < |Y| < 1.026 the umbra cone touch the surface of the Earth, where Y is the least distance from the axis of the moon's shadow to the center of the Earth in units of the equatorial radius of the Earth.
A new model have been designed, depend on the horizontal coordinates of the sun, moon, the distances Earth-Moon (rm), Earth-sun (rs) and |Y| to determine the date and times of total solar eclipse and the geogra
... Show MoreSituational regret and its relation to the vitality of conscience among university students The research seeks to identify situational regret and its relation to the vitality of conscience among university students, identify the significant differences in regard with students’ gender, and identify if there is a correlation between situational regret and the vitality of conscience. To do this, two scales were adopted; one to measure situational regret consisted of (31) items, which was designed by (Al-badrani, 2006), besides, costa and macrys’ (1992) scale that translated in Arabic language by (Al-qaisy, 2013). It composed of (35) items. Total of (120) male and female students were collected from three-different colleges (science, art
... Show MoreThis paper presents the results of investigating the vibrational characteristics of oblate dish with and without framed structure . A finite element method, was applied to the dynamic analysis of oblate spheroidal shell. Different types of elements were considered in one dimension and two dimensions. It was found that the natural frequencies of oblate shells had two types of behavior against increasing the shell thickness and eccentricity, which are the membrane mode and bending mode –Since – the membrane modes natural frequencies tend to increase with the increasing the eccentricity of oblate, while the bending modes natural frequencies decrease with the increasing the eccentricity till reach the optimum eccentricity.
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The quote of a Canadian communication scientist (Marshall McLuhan) (“The world has become an electronic village”) has become an archaic information compared to the great and rapid development of communication in the last two decades of the 20th century and what will happen later in the 21st century, to the extent that the world is called, thanks to the internet, a “Small screen” and this fact is a sign of the great progress that has been made in this field. As for the other statement of the Canadian communication scientist mentioned before “the medium itself, is the message”, it has been renewed and developed in its meaning and it’s purpose. Each new technical development in the means of communication necessarily means a me
... Show MoreThere is no access to basic sanitation for half the world's population, leading to Socioeconomic issues, such as scarcity of drinking water and the spread of diseases. In this way, it is of vital importance to develop water management technologies relevant to the target population. In addition, in the separation form of water treatment, the compound often used as a coagulant in water treatment is aluminum sulfate, which provides good results for raw water turbidity and color removal. Studies show, however, that its deposition in the human body, even Alzheimer's disease, can cause serious harm to health and disease development. The study aims to improve the coagulation/flocculation stage related to the amount of flakes, i
... Show MoreGelatin a promising biomaterial which is useful and interesting natural polymer which offer possibilities of chemical modification through grafted copolymerization with an saturated acid anhydride such as methyl nadic anhydride formatted gelatin –g- methyl nadic anhydride copolymer (A1), then modified to its corresponding polymer (A2) by substituted salbutamol as useful derivative as biomaterial .the prepared drug biopolymer was characterization by FTIR spectroscopy and thermal analysis was studied controlled drug release was measured in different buffer solution at 37C0 .