Natural fibers and particles reinforced composites are being broadly used due to their bio and specific properties such as low density and easy to machine and production with low cost. In this work, water absorption and mechanical properties such as tensile strength, flexural strength and impact strength of recycled jute fibers reinforced epoxy resin were enhanced by treating these fibers with alkaline solution. The recycled jute fibers were treated with different concentration of (NaOH) solution at (25 0C) for a period of (24) hours. From the obtained results, it was found that all these properties are improved when fibers treated with (7.5wt% NaOH) related to untreated fibers. Conversely, the mentioned properties of composites decreased after fibers treated with (10wt% NaOH). In addition, the hybrid composite with recycled jute fibers and recycled walnut shell powder showed obvious enhancement in the above-mentioned properties.
This research study the effect of surface modification and copper (Cu) plating carbon fiber (CF) surface on the thermal stability and wettability of carbon fiber (CF)/epoxy (EP) composites. The TGA result indicates that the thermal-stability of carbon fiber may be enhanced after Cu coating CF. TGA curve showed that the treatment temperature was enhanced thermal stability of Ep/CF, this is due to the oxidation during heating. The Cu plating increased the thermal conductivity, this increase might be due to reduce in contact resistance at the interface due to chemical modification and copper plating and tunneling resistance.
The increase of surface polarity after coating cause decreas
... Show MoreThe current research aims to know the relationship between bullying and parental treatment. (200) pupils were selected randomly from the fifth and sixth grades of primary schools.
Two instruments were used. The first was to measure bullying and it included 19 items. To measure parental treatment, the researchers adopted (Aletaby 2001) scale.
Statistical analysis showed that correlation between bullying , wiggle and Firm treatment style was positive Statistically significant .Bulling was correlated negatively with (neglect, careless, and Authoritarian treatment style.
The application of pultruded (GFRP) composite has become increasingly prominent in civil infrastructure projects. This study provides a comprehensive analysis of experimental and numerical studies conducted on the mechanical characteristics of (GFRP) composites across various temperature conditions, encompassing ambient and fire scenarios. The compilation comprises over 100 scholarly articles that examine the mechanical behavior of (GFRP) materials, specifically emphasizing their tensile and compressive strengths, showed the mechanical properties of (GFRP) materials are commonly compromised when exposed to high temperatures that approach or surpass the resin's glass transition temperature (Tg). In contrast, temperatures that are low
... Show MoreIn the current study, CuAl0.7In0.3Te2 thin films with 400 nm thickness were deposited on glass substrates using thermal evaporation technique. The films were annealed at various annealing temperatures of (473,573,673 and 773) K. Furthermore, the films were characterized by X-ray Diffraction spectroscopy (XRD), field emission scanning electron microscopy (FESEM), atomic force microscopy (AFM), and Ultra violet-visible (UV–vis). XRD patterns confirm that the films exhibit chalcopyrite structure and the predominant diffraction peak is oriented at (112). The grain size and surface roughness of the annealed films have been reported. Optical properties for the synthesized films including, absorbance, transmittance, dielectric constant, and refr
... Show MoreTransparent thin films of CdO:Ce has been deposited on to glass and silicon substrates by spray pyrolysis technique for various concentrations of cerium (2, 4, and 6 Vol.%). CdO:Ce films were characterized using different techniques such as X-ray diffraction (XRD), atomic force microscopy(AFM) and optical properties. XRD analysis show that CdO films exhibit cubic crystal structure with (1 1 1) preferred orientation and the intensity of the peak increases with increasing's of Ce contain when deposited films on glass substrate, while for silicon substrate, the intensity of peaks decreases, the results reveal that the grain size of the prepared thin film is approximately (73.75-109.88) nm various with increased of cerium content. With a sur
... Show MoreThe aim of this paper, study the effect of carbon nanotubes on the electrical properties of polyvinylchloride. Samples of polyvinylchloride carbon nanotubes composite prepared by using hot press technique. The weight percentages of carbon nanotubes are 0,5,10 and 20wt.%. Results showed that the D.C electrical conductivity increases with increasing of the weight percentages of carbon nanotubes. Also, the D.C electrical conductivity changed with increase temperature for different concentrations of carbon nanotubes. The activation energy of D.C electrical conductivity is decreased with increasing of carbon nanotubes concentration.
Light is an important factor that influences the growth and photosynthetic efficiency of microalgae; however, little is known about how light intensity together with the wavelength affect the photosynthetic capacity and growth of marine microalgae. In the present study, the growth of the marine green microalga Dunaliella parva was studied and optimized under different light intensities (25 ~ 70 μmol m-2 s-1) and qualities (blue, green, and red) in comparison with white light at 40 μmol m-2 s-1 as a control. The growth was monitored by counting the cell number, pigment content, Chl a, Chl b, and carotenoids concentrations. The optimal growth and highest photosyntheti
... Show MoreIndium Antimonide (InSb) thin films were grown onto well cleaned glass substrates at substrate temperatures (473 K) by flash evaporation. X-ray diffraction studies confirm the polycrystalline of the films and the films show preferential orientation along the (111) plane .The particle size increases with the increase of annealing time .The transmission spectra of prepared samples were found to be in the range (400-5000 cm-1 ) from FTIR study . This indicates that the crystallinity is improved in the films deposited at higher annealing time.