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−1 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−1 is due to O–H stretching vibration of hydroxyl groups and the peak at 1712 cm−1 corresponds to the carboxylic (C=O) group attached to the carbon fiber. The peaks at 2927 cm−1 and 2862 cm−1 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 σAC 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.
Abstract Portable communication devices such as WLAN, WiMAX, LTE, ISM, and 5G utilize one or more of the triple bands at (2.32.7 GHz,3.4–3.6GHz,and5–6GHz)andsufferfromtheeffectofmultipathproblemsbecausetheyareusedinurbanregions.To date, no one has performed a review of the antennas used for these types of wireless communications. This study reviewed two types of microstrip antennas (slot and fractal) that have been reported by researchers (as a single element) using a survey that included the evaluation of several important specifications of the antennas in previous research, such as operating bandwidth, gain, efficiency, axial ratio bandwidth (ARBW), and size. The weaknesses in the design of all antennas were carefully identified to de
... Show MoreCreatinine and Schiff`s bases are well known for their diverse range of biological activities and are thought to be emerging and useful therapeutic targets for the treatment of several diseases. The present work was aimed at the synthesis of new imidazolidine-4-one, thiazolidine-4-one, and oxazolidine-4-one derivatives derived from creatinine and to illustrate their influence on a colon cancer cell line and assess their antioxidant activity. Creatinine was reacted with α-chloroethyl acetate to produce 2-ethyl acetate creatinine 1. Then, the reaction of compound 1 with n-propyl bromide afforded N-propyl-2-ethylacetate creatinine 2. Compound 2
... Show MoreA study were conducted to examinate the effect of organic and aqueous (Hot, Cold) Extracts from leaves of Duranta repens on the growth and activities of the following types of Bacteria:- Staphylococcus aureus,Streptococcus pyogens ,Escherichia coli,Klebsilla pneumonia, in addition to the yeast Candida albicans and the fungi Aspergullis niger ,Aspergulls flavus.The result showed that gram Positive Bacteria is more sensitive to the extracts than gram negative bacteria with Minimum inhibitory concentration (MIC) value (50,25,50,100)% and Minimum Bactericidal Concentration (MBC) value (100,50,200,100)% for all types Bacteria respectively . The most active extract against A.niger ,A,flavus was cold and hot aqueous extract from the leaves with d
... Show MoreA factorial experiment was conducted at the laboratories of the College of Agriculture – Kerbala University during 2016. The aim was inhibitory efficiency for some aqueous and alcoholic extracts of Cumin, Fenugreek, Sweet Fennel and Black cumin in growth of Escherichia coli and Staphylococcus aureus bacteria. Results of Lab the extracts alcoholic, Concentrations 10, and 20 μg/ml giving to the highest percentage of inhibition from water extracts for both types of bacteria. Alcoholic extract of cumin highest percentage inhibition and concentration reached 23 and 26 mm, respectively, for the bacterium Staphylococcus aureus, while the bacteria Escherichia coli giving the alcoholic extract of the concentration of 20 μg/ml
... Show MoreThe study's goals were to separate and identify endophytic fungi from Aloe vera leaves by looking at their morphology and molecules, as well as to find the chemical compounds in the leaf extract by using HPLC, GC, and GC-Mass instruments. The results showed that 53 endophytic fungi were isolated from a total of 120 pieces of A. vera leaves, with a total colonization rate of 44.16%. The fungus Aspergillus terreus had a colonization rate of 14.16%; Aspergillus niger had a colonization rate of 13.33%; Penicillium chermesinum demonstrated a colonization rate of 6.66%; Paecilomyces variotii had a colonization rate of 2.5%; Talaromyces radicus; and Aspergillus flavus achie
... Show MoreThis study concluded detection of Toxoplasma gondii in milk, immunologically by using Elisa and nested PCR)nPCR (based on B1 gene, also to investigate the effect of toxoplasmosis, parity, breed and flock on some milk composition in the Iraqi local and Shami goats in the middle of Iraq. A total of 80 milk samples of the lactating goats were collected. Results of this study showed the prevalence of Toxoplasmosis was 21.25% and 28.75% by Elisa and nPCR respectively without significant differences. The sensitivity of Elisa was a low (30.43%) whereas the specificity was a high (82.45%). The degree of agreement estimated by Kappa coefficient revealed a slight agreement (0.14) between two methods. The results indicated that goats infected
... Show MoreAn experiment was conducted at the laboratories of College of Agriculture – Kerbala University during 2016. The aim of this study was to the effect of water extracts of medicinal plants germination percentage and development of plumule and radicle growth .The completely randomized design with three replicates was usedin each experiment consisted of water extracts (T1= Distilled water),(T2= Eruca sativa Eruca sativa L),(T3= Fenugreek ïºï»Ÿïº¤ï» ﺒﺔTrigonella foenum - graecum L),(T4= Sweet FennelFoeniculum vulgare.Mill),(T5=Borage Anchusa strigosa Lab),(T6=Dill Anethum graveolens L) ,(T7=Black cuminNigella Sativa L),(T8=Cumin Cuminumcyminum L),(T9= CorianderCoriandrum sativum L. ). Results of Lab.
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