Preferred Language
Articles
/
bhbXE4gBVTCNdQwCinNA
Electrical and thermal characteristics of MWCNTs modified carbon fiber/epoxy composite films
...Show More Authors
Abstract<p>To enhance interfacial bonding between carbon fibers and epoxy matrix, the carbon fibers have been modified with multiwall carbon nanotubes (MWCNTs) using the dip- coating technique. FT-IR spectrum of the MWCNTs shows a peak at 1640 cm<sup>−1</sup> corresponding to the stretching mode of the C=C double bond which forms the framework of the carbon nanotube sidewall. The broad peak at 3430 cm<sup>−1</sup> is due to O–H stretching vibration of hydroxyl groups and the peak at 1712 cm<sup>−1</sup> corresponds to the carboxylic (C=O) group attached to the carbon fiber. The peaks at 2927 cm<sup>−1</sup> and 2862 cm<sup>−1</sup> are assigned to C–H stretching vibration of epoxy produced at the defect sites of acid-oxidized carbon fiber surface. SEM image shows a better interface bonding between the fiber and the matrix of modified composites (MWCNTs-CF/Ep) than those of unmodified composite. The loss factor curve of CF-MWCNTs/Ep composites is the narrowest compared with neat epoxy and CF/Ep composites which evinces that the length distribution range of molecular chain segments in the matrix is the narrowest. From the dependence of the AC conductivity on temperature, we can see that σ<sub>AC</sub> increases when temperature increases. The increase in electrical conductivity of the composites may be a result of the increased chain ordering due to annealing effect. The use of MWCNTs to modify the surface of carbon fiber resulted in a large amount of junctions among MWCNT causing an increase in the electrical and thermal conductivity by forming conducting paths in the matrix. The MWCNTs-CF/Ep composite shows better thermal stability than unmodified composites. The strong interaction between CF and MWCNTs can retard diffusion of small molecules from the resin matrix at high temperature and hence, result in the improved thermal stability of the modified CF/Ep composite.</p>
Scopus Clarivate Crossref
View Publication
Publication Date
Tue Sep 01 2020
Journal Name
Baghdad Science Journal
Modified Weighted Pareto Distribution Type I (MWPDTI)
...Show More Authors

In this paper, the Azzallini’s method used to find a weighted distribution derived from the standard Pareto distribution of type I (SPDTI) by inserting the shape parameter (θ) resulting from the above method to cover the period (0, 1] which was neglected by the standard distribution. Thus, the proposed distribution is a modification to the Pareto distribution of the first type, where the probability of the random variable lies within the period  The properties of the modified weighted Pareto distribution of the type I (MWPDTI) as the probability density function ,cumulative distribution function, Reliability function , Moment and  the hazard function are found. The behaviour of probability density function for MWPDTI distrib

... Show More
View Publication Preview PDF
Scopus (3)
Crossref (1)
Scopus Clarivate Crossref
Publication Date
Wed Feb 08 2023
Journal Name
Iraqi Journal Of Science
Modified Light Stemming Algorithm for Arabic Language
...Show More Authors

Stemming is a pre-processing step in Text mining applications as well as it is very important in most of the Information Retrieval systems. The goal of stemming is to reduce different grammatical forms of a word and sometimes derivationally related forms of a word to a common base (root or stem) form like reducing noun, adjective, verb, adverb etc. to its base form. The stem needs not to be identical to the morphological root of the word; it is usually sufficient that related words map to the same stem, even if this stem is not in itself a valid root. As in other languages; there is a need for an effective stemming algorithm for the indexing and retrieval of Arabic documents while the Arabic stemming algorithms are not widely available.

... Show More
View Publication Preview PDF
Publication Date
Sun Dec 30 2012
Journal Name
Al-kindy College Medical Journal
Modified alvarado scoring system. How much helpful?
...Show More Authors

Background:-The Modified Alvarado Scoring System (MASS) has been reported to be a cheap and quick diagnostic tool in patients with acute appendicitis. However, differences in diagnostic accuracy have been observed if the scores were applied to various populations and clinical settings.
Objectives:- The purpose of this study was to evaluate the diagnostic value of Modified Alvarado Scoring System in patients with acute appendicitis in our setting.
Methods:-one hundre twenty eight patients ,were included in this study, admitted to Al-Kindy teaching hospital from June 2009 to June 2010. Patients’ age ranged from 8 to 56 years (21±10) they were divided into three groups; paediatrics, child bearing age females & adult males,. MAS

... Show More
View Publication Preview PDF
Publication Date
Wed Feb 08 2023
Journal Name
Iraqi Journal Of Science
A Modified Key Scheduling Algorithm for RC4
...Show More Authors

Rivest Cipher 4 (RC4) is an efficient stream cipher that is commonly used in internet protocols. However, there are several flaws in the key scheduling algorithm (KSA) of RC4. The contribution of this paper is to overcome some of these weaknesses by proposing a new version of KSA coined as modified KSA . In the initial state of the array is suggested to contain random values instead of the identity permutation. Moreover, the permutation of the array is modified to depend on the key value itself. The proposed performance is assessed in terms of cipher secrecy, randomness test and time under a set of experiments with variable key size and different plaintext size. The results show that the RC4 with improves the randomness and secrecy with

... Show More
View Publication Preview PDF
Publication Date
Tue Jan 08 2019
Journal Name
Iraqi Journal Of Physics
X- ray diffraction and dielectric properties of PbSe thin films
...Show More Authors

Lead selenide PbSe thin films of different thicknesses (300, 500, and 700 nm) were deposited under vacuum using thermal evaporation method on glass substrates. X-ray diffraction measurements showed that increasing of thickness lead to well crystallize the prepared samples, such that the crystallite size increases while the dislocation density decreases with thickness increasing. A.C conductivity, dielectric constants, and loss tangent are studied as function to thickness, frequency (10kHz-10MHz) and temperatures (293K-493K). The conductivity measurements confirm confirmed that hopping is the mechanism responsible for the conduction process. Increasing of thickness decreases the thermal activation energy estimated from Arhinus equation is

... Show More
View Publication Preview PDF
Crossref (2)
Crossref
Publication Date
Tue May 01 2018
Journal Name
Journal Of Physics: Conference Series
Doping And Annealing Effect On Evaporation Of ZnO Thin Films
...Show More Authors

View Publication Preview PDF
Scopus (2)
Scopus Clarivate Crossref
Publication Date
Mon Mar 08 2021
Journal Name
Baghdad Science Journal
New Solar Thermal Materials
...Show More Authors

A number of ehemical ion materials were used as an absorber against solar energy. These materials were selected according to their absorption spectra in the wavelength range 300-800nm where the solar spectrum is coventrated. A solar olleetorw^esigd and The ability of each material inside the collector for absorbing the solar radiation was examined by a converter parameter “R”.According to the “R” parameter, the cohaltous and copperic ions material seems to be of higher capability for absorbing solar energy than the other materials.All the results were analyzed by means of a least-squared fitting program.

View Publication Preview PDF
Crossref
Publication Date
Mon Jan 30 2023
Journal Name
Iraqi Journal Of Science
Characteristics of Lead and Sulfur Plasma Parameters by Optical Emission Spectroscopy
...Show More Authors

This study uses the optical emission spectroscopy (OES) technique to find the lead(Pb) and sulfur (S) plasma parameters employing a pulse of Nd: YAG laser (Q-switched 1064nm wavelength) and different laser energies of (400,500,600 and 700 mJ). The electron temperature Te (eV) is calculated using the Boltzmann-Plot method, and the electron density ne (cm-3)is determined by the Stark broadened way. Moreover, Debye length λD (cm) and plasma frequency ωp (Hz) are studied as a function of laser energy. An apparent increase was noted in the electron temperature of lead plasma and a decrease in sulfur plasma. The results also showed that each increase in the laser intensity causes an incr

... Show More
View Publication Preview PDF
Scopus (5)
Crossref (4)
Scopus Crossref
Publication Date
Wed Jan 01 2020
Journal Name
Journal Of Information Hiding And Multimedia Signal Processing
Enhancement of lsb audio steganography based on carrier and message characteristics
...Show More Authors

Data steganography is a technique used to hide data, secret message, within another data, cover carrier. It is considered as a part of information security. Audio steganography is a type of data steganography, where the secret message is hidden in audio carrier. This paper proposes an efficient audio steganography method that uses LSB technique. The proposed method enhances steganography performance by exploiting all carrier samples and balancing between hiding capacity and distortion ratio. It suggests an adaptive number of hiding bits for each audio sample depending on the secret message size, the cover carrier size, and the signal to noise ratio (SNR). Comparison results show that the proposed method outperforms state of the art methods

... Show More
Publication Date
Tue Feb 01 2022
Journal Name
Iraqi Journal Of Science
Hydrochemical Characteristics and Seasonal Variations of Al-Hammar Marsh, Southern Iraq
...Show More Authors

Devastated by the combined impact of massive drainage works and upstream damming since the 1980's, Al-Hammar Marsh, Southern Iraq, has completely collapsed with 94 % of its land cover transformed into bare land and salt crusts by 2000. After a policy initiated to restore the Iraqi marshes again in 2003, the marsh recovered about half of its former area. As a part of the ecological recovery assessment of this newly inundated marsh, it is important to investigate the extend impact of desiccation after 3 years of inundation on water quality as the latter plays an important role in the restoration process of the marshes. Therefore, from a restoration point of view, major and trace element distribution and sourcing as well as seasonal variati

... Show More
View Publication Preview PDF