In this paper a refractive index sensor based on micro-structured optical fiber has been proposed using Finite Element Method (FEM). The designed fiber has a hexagonal cladding structure with six air holes rings running around its solid core. The air holes of fiber has been infiltrated with different liquids such as water , ethanol, methanol, and toluene then sensor characteristics like ; effective refractive index , confinement loss, beam profile of the fundamental mode, and sensor resolution are investigated by employing the FEM. This designed sensor characterized by its low confinement loss and high resolution so a small change in the analyte refractive index could be detect which is could be useful to detect the change of the information of the biological molecule reaction and also in medical applications in fields like toxins, drug residues, vitamins, antibodies, proteins and parasites.
In this study, geopolymer mortar was designed in various experimental combinations employing 1% micro steel fibers and was subjected to different temperatures, according to the prior works of other researchers. The geopolymer mortar was developed using a variety of sustainable material proportions (fly ash and slag) to examine the influence of fibers on its strength. The fly ash weight percentage was 50%, 60%, and 70% by slag weight to study its effect on the geopolymer mortar's properties. The optimal ratio produced the most significant results when mixed at a 50:50 ratio of fly ash and slag with 1% micro steel fibers at curing temperature 240oC for 4 hours through two days. The compressive strength of the geopolymer mortar increas
... Show MoreFour simply supported reinforced concrete (RC) beams were test experimentaly and analyzed using the extended finite element method (XFEM). This method is used to treat the discontinuities resulting from the fracture process and crack propagation in that occur in concrete. The Meso-Scale Approach (MSA) used to model concrete as a heterogenous material consists of a three-phasic material (coarse aggregate, mortar, and air voids in the cement paste). The coarse aggregate that was used in the casting of these beams rounded and crashed aggregate shape with maximum size of 20 mm. The compressive strength used in these beams is equal to 17 MPa and 34 MPa, respectively. These RC beams are designed to fail due to flexure when subjected to lo
... Show MoreBackground. Body mass index (BMI) is a person's weight in kilograms (or pounds) divided by the square of height in meters (or feet). Obesity affects a wide spectrum of age groups, from the young to the elderly, and there are several eye diseases related to obesity like diabetic retinopathy, floppy eyelid syndrome, retinal vein occlusion, stroke-related vision loss, age-related macular degeneration, and possibly, refractive errors. Refractive errors (RE) are optical imperfections related to the focusing ability of the eye and are the main cause of visual impairment which may result in missed education and employment opportunities, lower productivity and impaired quality of life. Aim. The study aimed to find an association between bod
... Show MoreIn this paper, simulation study of the frequency shift of photonic bandgaps due to refractive index scaling using liquids filled hollow-core photonic crystal fibers is presented. Different liquids (distilled water, n-hexane, methanol, ethanol and acetone) are used to fill the cladding of 2 types of hollow core photonic crystal fibers (HC19-1060, HC7-1060). These liquids are used to change the effective index scaling and index contrast of the cladding. The effect of increasing temperature of the liquid (20-100 0C for water and 20-70 0C for other liquids ) infiltrated hollow core fiber on the bandgap width and transmission properties has been computed. The maximum photonic bandgap width at 0.0243 has appeared with filling HC7-1060 PCF with
... Show MoreIn this study, the stresses and displacement around a tunnel opening under water body in Baghdad city, middle of Iraq, during excavation and lining are discussed. For this purpose, the finite element method (FEM) was adopted as an effective approach to analyze the problem using (SIGMA/W) program. The research includes the study of the behavior of soil due to excavation of a tunnel by calculating the displacements and stresses in three positions of the tunnel (crown, wall, and invert) during the various stages of construction. The surface settlement is also studied. The finite element analyses were carried out Using (Elastic- plastic) and (linear elastic) models for the soil and the concrete liner respectively.
Computer models are used in the study of electrocardiography to provide insight into physiological phenomena that are difficult to measure in the lab or in a clinical environment.
The electrocardiogram is an important tool for the clinician in that it changes characteristically in a number of pathological conditions. Many illnesses can be detected by this measurement. By simulating the electrical activity of the heart one obtains a quantitative relationship between the electrocardiogram and different anomalies.
Because of the inhomogeneous fibrous structure of the heart and the irregular geometries of the body, finite element method is used for studying the electrical properties of the heart.
This work describes t
... Show MoreBending effects on the transmission of optical signal are investigated on a single mode
optical fiber (SMOF) of 10 m length, core radius of 5 μm and optical refractive index difference
0.003. The bending radii (R) were between 0.08 and 0.0015 m. A great decrease in the amplitude is
shown for radii below 0.01 m. Sudden break down occurs for radii less than 0.0015 m. Birefringence
(B) is difficult to measure for long fibers. Meanwhile, B was found by comparing with calibrated
fiber of the same properties but of length of 0.075 m. The results show an increase in propagation
constant (Δβ) and the decrease in beat length (Lb), and show that bending decreases the critical radius
of curvature (Rc) related to B. The chang
Seepage occurs under or inside structures or in the place, where they come into contact with the sides under the influence of pressure caused by the difference in water level in the structure U / S and D / S. This paper is designed to model seepage analysis for Kongele (an earth dam) due to its importance in providing water for agricultural projects and supporting Tourism sector. For this purpose, analysis was carried out to study seepage through the dam under various conditions. Using the finite element method by computer program (Geo-Studio) the dam was analysed in its actual design using the SEEP / W 2018 program. Several analyses were performed to study the seepage across Kongele
Finite Element Approach is employed in this research work to solve the governing differential equations related to seepage via its foundation's dam structure. The primary focus for this reason is the discretization of domain into finite elements through the placement of imaginary nodal points and the discretization of governing equations into an equation system; An equation for each nodal point or part, and unknown variables are solved. The SEEP / W software (program) is a sub-program of the Geo-Studio software, which is used by porous soil media to compensate for the problems of seepage. To achieve the research goals, a study was carried out on Hemrin dam, which located in the Diyala River 100 km northeast of Baghdad, Iraq. Thus, o
... Show MoreTwo dimensional meso-scale concrete modeling was used in finite element analysis of plain concrete beam subjected to bending. The plane stress 4-noded quadrilateral elements were utilized to model coarse aggregate, cement mortar. The effect of aggregate fraction distribution, and pores percent of the total area – resulting from air voids entrapped in concrete during placement on the behavior of plain concrete beam in flexural was detected. Aggregate size fractions were randomly distributed across the profile area of the beam. Extended Finite Element Method (XFEM) was employed to treat the discontinuities problems result from double phases of concrete and cracking that faced during the finite element analysis of concrete beam. Crac
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