Silicon nanowire arrays (SiNWs) are created utilizing the metal-assisted chemical etching method with an Ag metal as a catalyst and different etching time of 15, 30, and 60 minutes using n-Si (100). Physical properties such as structural, surface morphology, and optical properties of the prepared SiNWs are studied. The diameter of prepared SiNWs ranged from 20 to 280 nm, and the reflectance in the visible part of the wavelength spectrum was less than 1% for all prepared samples. The obtained energy gap of prepared SiNWs was around 2 eV, which is higher than the energy gap of bulk silicon. X-ray diffraction (XRD) has diffraction peaks at 68.70o for all prepared samples. The heterojunction solar cell was fabricated based on the n-SiNWs/ P3HT/PEDOT: PSS structure. The heterojunction solar cell produced for 60 minutes has the highest Jsc of 11.55 mA.cm-2 and a conversion efficiency of 0.93%. Based on SiNWs prepared for etching time of 15 min, the solar cell demonstrated Jsc and Voc of 2.73 mA/cm2 and 0.46 V, respectively, and a conversion efficiency of 0.34%.
The study scrutinises intermingled relations between children literature and some ecological issues. Such interwoven relationships would be highly recommended to encourage children to explore and identify themselves with nature from early ages to avoid facing an extreme experience later on. The research limits its scope to two novels Suzanne Collins’ (1962) The Hunger Games trilogy (2003-2007) and William Golding’s (1911-1993) Lord of the Flies (1954), and both novels have no direct connections with Ecology and the Eco-consciousness, yet it offers an insightful description about Man’s experience with Nature. Moreover, it raises serious moral questions, raises awareness, heals wounds and suggests solutions for the problems th
... Show MoreExperimental and numerical investigations of the centrifugal pump performance at non-cavitating and cavitating flow conditions were carried out in the present study. Experiments were performed by applying a vacuum to a closed-loop system to investigate the effects of the net positive suction head available (NPSHa), flow rate, water temperature and pump speed on the centrifugal pump performance. Accordingly, many of the important parameters concerning cavitation phenomenon were calculated. Also, the noise which is accompanied by cavitation was measured. Numerical analysis was implemented for two phase flow (the water and its vapor) using a 2-D simulation by ANSYS FLUENT software to investigate the internal flow of centrifugal pump under c
... Show MoreThe basic concepts of some near open subgraphs, near rough, near exact and near fuzzy graphs are introduced and sufficiently illustrated. The Gm-closure space induced by closure operators is used to generalize the basic rough graph concepts. We introduce the near exactness and near roughness by applying the near concepts to make more accuracy for definability of graphs. We give a new definition for a membership function to find near interior, near boundary and near exterior vertices. Moreover, proved results, examples and counter examples are provided. The Gm-closure structure which suggested in this paper opens up the way for applying rich amount of topological facts and methods in the process of granular computing.
Automatic recognition of individuals is very important in modern eras. Biometric techniques have emerged as an answer to the matter of automatic individual recognition. This paper tends to give a technique to detect pupil which is a mixture of easy morphological operations and Hough Transform (HT) is presented in this paper. The circular area of the eye and pupil is divided by the morphological filter as well as the Hough Transform (HT) where the local Iris area has been converted into a rectangular block for the purpose of calculating inconsistencies in the image. This method is implemented and tested on the Chinese Academy of Sciences (CASIA V4) iris image database 249 person and the IIT Delhi (IITD) iris
... Show MoreIn the current study, haemoglobin analytes dissolved in a special buffer (KH2PO4(1M), K2HPO4(1M)) with pH of 7.4 were used to record absorption spectra measurements with a range of concentrations from (10-8 to 10-9) M and an absorption peak of 440nm using Broadband Cavity Enhanced Absorption Spectroscopy (BBCEAS) which is considered a simple, low cost, and robust setup. The principle work of this technique depends on the multiple reflections between the light source, which is represented by the Light Emitting Diode 3 W, and the detector, which is represented by the Avantes spectrophotomer. The optical cavity includes two high reflectivity ≥99% dielectric mirrors (dia
... Show More<p>In this paper, a simple color image compression system has been proposed using image signal decomposition. Where, the RGB image color band is converted to the less correlated YUV color model and the pixel value (magnitude) in each band is decomposed into 2-values; most and least significant. According to the importance of the most significant value (MSV) that influenced by any simply modification happened, an adaptive lossless image compression system is proposed using bit plane (BP) slicing, delta pulse code modulation (Delta PCM), adaptive quadtree (QT) partitioning followed by an adaptive shift encoder. On the other hand, a lossy compression system is introduced to handle the least significant value (LSV), it is based on
... Show MoreThis study shows impoliteness as a form of face-threatening that can be intentionally caused by verbal threats in a particular setting. It investigates: what strategies and mitigators do Iraqi-Kurdish English as a foreign language (EFL) learners use in situations of threat responses? The present investigation paper aims to examine impoliteness strategies and mitigators by these learners when they respond to threatening situations in their context. Thus, it fills a gap in pragmatics literature by investigating the reactions to threats in an Iraqi-Kurdish EFL context. To this end, 50 participants have participated in this study. An open-ended questionnaire in the form of a Discourse Completion Task (DCT) is used to elicit responses fr
... Show MoreThis work is concerned with the design and performance evaluation of a shell and double concentric tubes heat exchanger using Solid Works and ANSY (Computational Fluid Dynamics).
Computational fluid dynamics technique which is a computer-based analysis is used to simulate the heat exchanger involving fluid flow, heat transfer. CFD resolve the entire heat exchanger in discrete elements to find: (1) the temperature gradients, (2) pressure distribution, and (3) velocity vectors. The RNG k-ε model of turbulence is used to determining the accurate results from CFD.
The heat exchanger design for this work consisted of a shell and eight double concentric tubes. The number of inlets are three and that of o
... Show MoreThe aim of the current study was to evaluate the knowledge and perception of the fifth stage pharmacy students (college of pharmacy/ University of Baghdad /Iraq) regarding generic medicines. This study is a cross-sectional study carried in a college of pharmacy /University of Baghdad during the period from (November 2018- March 2019). The number of students included in the current study was 168 undergraduate stager pharmacists. A questionnaire was used to collect data of the study. Nearly 86% of the students said that they had heard of generic and brand medicines, and pharmacy was the main source of knowledge regarding generic medicines (66.7%). About (33.3%) of the respondents agreed that generic medicines are bioequivalent to br
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