Single mode-no core-single mode fiber structure with a section of tuned no-core fiber diameter to sense changes in relative humidity has been experimentally demonstrated. The sensor performance with tuned NCF diameter was investigated to maximize the evanescent fields. Different tuned diameters of of (100, 80, and 60)μm were obtained by chemical etching process based on hydrofluoric acid immersion. The highest wavelength sensitivity was obtained 184.57 pm/RH% in the RH range of 30% –100% when the no-core fiber diameter diameter was 60 μm and the sensor response was in real-time measurements
This work aims to fabricate two types of plasmonic nanostructures by electrical exploding wire (EEW) technique and study the effects of the different morphologies of these nanostructures on the absorption spectra and Surface-Enhanced Raman Scattering (SERS) activities, using Rhodamine 6G as a probe molecule. The structural properties of these nanostructures were examined using X-Ray diffraction (XRD). The morphological properties were examined using field emission scanning electron microscopy (FESEM) and scanning transmission electron microscopy (STEM). The absorption spectra of the mixed R6G laser dye (concentration 1×10-6 M) with prepared nanostructures were examined by double beam UV-Vis Spectrophotometer. The Raman spe
... Show MoreText documents are unstructured and high dimensional. Effective feature selection is required to select the most important and significant feature from the sparse feature space. Thus, this paper proposed an embedded feature selection technique based on Term Frequency-Inverse Document Frequency (TF-IDF) and Support Vector Machine-Recursive Feature Elimination (SVM-RFE) for unstructured and high dimensional text classificationhis technique has the ability to measure the feature’s importance in a high-dimensional text document. In addition, it aims to increase the efficiency of the feature selection. Hence, obtaining a promising text classification accuracy. TF-IDF act as a filter approach which measures features importance of the te
... Show MoreBackground: Ventricular septal defect (VSD) is the most commonly recognized congenital heart defect. Isolated VSDs represent about 20-30% of all congenital cardiac malformations and have a prevalence of 1- 2 % per 1,000 live births.
Objective: This study is planned to review the outcome of surgical closure of VSD at Ibn Al-Nafees Teaching Hospital (Department Cardiac Surgery) Baghdad/Iraq.
Patients and methods: This study includes 50 cases of VSD both isolated and VSD associated with other congenital malformations admitted and underwent surgical repair of age range between 3 to 28 years and weight range between 9 to 80 kg. Different type of VSD, were found and repaired whether isolated or with other associated congenital anomalies
This research aims to analyze the indicators of spatial variation in the guide of health field in both Al-Adhamiyah and Rusafa districts according to the environmental and administrative units in 2016. The analysis was done by groups of health guide indicators. The objectives of the study were to identify the spatial variation of health services and assess the health situation for families following the environmental and administrative units of the studied area. Such objectives can be done by specifying the extent of the families’ consent to the type of services, measuring the cases of deprivation, and identifying the most deprived areas. The study has finally concluded that there is a clear spatial variation between the indicators and
... Show MoreThe current research aims to recognize the exploratory and confirmatory factorial structure of the test-wiseness scale on a sample of Hama University students, using the descriptive method. Thus, the sample consists of (472) male and female students from the faculties of the University of Hama. Besides, Abu Hashem’s 50 item test-wiseness scale (2008) has been used. The validity and reliability of the items of the scale have also been verified, and six items have been deleted accordingly. The results of the exploratory factor analysis of the first degree have shown the presence of the following five acceptable factors: (exam preparation, test time management, question paper handling, answer sheet handling, and revision). Moreover,
... Show MoreThis paper reports a fiber Bragg grating (FBG) as a biosensor. The FBGs were etched using a chemical agent,namely,hydrofluoric acid (HF). This implies the removal of some part of the cladding layer. Consequently, the evanescent field propagating out of the core will be closer to the environment and become more sensitive to the change in the surrounding. The proposed FBG sensor was utilized to detect toxic heavy metal ions aqueous medium namely, copper ions (Cu2+). Two FBG sensors were etched with 20 and 40 μm diameters and fabricated. The sensors were studied towards Cu2+ with different concentrations using wavelength shift as a result of the interaction between the evanescent field and copper ions. The FBG sensors showed
... Show MoreMode filtering technique is one of the most desired techniques in optical fiber communication systems, especially for multiple input multiple output (MIMO) coherent optical communications that have mode-dependent losses in communication channels. In this work, a special type of optical fiber sensing head was used, where it utilizes DCF13 that is made by Thorlabs and has two numerical apertures (NA’s). One is for core and 1st cladding region, while the 2nd relates the 1st cladding to the 2nd cladding. Etching process using 40 % hydro-fluoric (HF) acid was performed on the DCF13 with variable time in minutes. Investigation of the correlation between the degree of etching and the re
Abstract: In this work we demonstrate and investigate the optical pulse propagation in a photonic band gap fiber Bragg grating (FBG). The light propagates in opposite direction in FBG is explained and discussed by a Coupled Mode Theory (CMT). The photonic band gap (stop band gap) is created by fabricated, a Bragg grating in optical fiber. The results show the pulse spectrum falls entirely within the stop band gap, the entire pulse is reflected by the grating, while when the pulse spectrum is outside the stop band gap the pulses will transmitted through the grating. The group velocity (VG) becomes zero at the edges of the stop band and group velocity dispersion β2 is anomalous on the shorter side of stop band gap whereas β2 for uniform fi
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