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 work aimed to produce PVA and PVA/Ag nanofibers ultra-high sensitivity photodetector by electrospinning. The electrospinning process was used to successfully prepare PVA nanofibers and a PVA-Ag nanofiber composite. FE-SEM, XRD, UV, I-V characterizations are used to study the morphological, structural, optical, and electrical properties of the material. In contrast, the PVA-Ag nanofiber composite film displayed a cubic structure with favored orientation (200) that indicated the presence of Ag NPs in the PVA-Ag nanofibers film. While the optical energy gap for PVA was 3.96 eV, it was only 2.14 eV for PVA-Ag nanofibers composite film, making this composite sensitive to visible light, particularly green light at 550 nm with a 65% photosens
... Show MoreWith a descriptive and analytical approach, it discusses the concept of phenomenology as an approach to seeing the aesthetics of ugliness as one of the concepts associated with the aesthetic experience in contemporary art designs, as it is the result of communication between artistic production and the recipient, which leads to creating a state of aesthetic pleasure. A phenomenological method is used to uncover the aesthetics of ugly and to connect ugliness and beauty since ugliness in aesthetics incorporates beauty as a modern aesthetic vision from the phenomenological perspective. The study investigated aesthetics as a phenomenon of perception, sensory knowledge, and the aesthetic response to the production of designs in contemporary a
... Show MoreBackground: Irrigation has a central role in endodontic treatment. Several irrigating solutions have the antimicrobial activity and actively kill bacteria and yeasts when introduced in direct contact with the microorganisms. The purpose of this study was to evaluate the antimicrobial effectiveness of Dandelion (Taraxacum officinale) root and leaf extracts as possible irrigant solutions, used during endodontic treatments, and both were compared to Sodium hypochlorite, Propolis and Ethyl alcohol. Materials and Method: Forty seven human extracted single rooted teeth were selected. The teeth were decoronated using a diamond disk to have a length of 15 mm ±1 mm and they were instrumented using the hybrid technique. All roots were sterilized
... Show MoreA total of 680 fish specimens belonging to 31 species from the Yemeni coastal waters of the Red Sea were inspected for the isopod infestations. Four isopod species belonging to three families of the suborder Cymothoida were detected. These are: Aega psora (Linnaeus, 1758) from Lethrinus lentjan, Natatolana insignis Hobbins and Jones, 1993 from Abalistes stellatus, Excorallana tricornis (Hansen, 1890) from Epinephelus fuscoguttatus, E. guttatus and E. tauvina and Alcirona krebsi Hansen, 1890 from Epinephelus microdon. All these isopod species are reported here for the first time from the Yemeni coastal waters of the Red Se
... Show MoreThis paper investigates the experimental response of composite reinforced concrete with GFRP and steel I-sections under limited cycles of repeated load. The practical work included testing four beams. A reference beam, two composite beams with pultruded GFRP I-sections, and a composite beam with a steel I-beam were subjected to repeated loading. The repeated loading test started by loading gradually up to a maximum of 75% of the ultimate static failure load for five loading and unloading cycles. After that, the specimens were reloaded gradually until failure. All test specimens were tested under a three-point load. Experimental results showed that the ductility index increased for the composite beams relative to the reference specim
... Show MoreABSTRACT This study closely investigates the elements of Sigmund Freud’s theory “The Uncanny” in one of Larson’s most famous novels. Although the novel touches upon racial issues, the study explores the mysterious relationship between Irene and Clare based on the main features of Freud’s “The Uncanny,” which are represented by hidden sexual desire, envy, supernatural power, and double characters. The aspect of the sexual desire is indicated in the novel by sexual undertones expressed by Irene towards Clare’s physical features. Envy in the novel is expressed by Irene who shows resentful longing aroused by Clare’s possessions and qualities due to her passing to the white community. The aspect of omnipotence of thoughts is in
... Show MoreThe Ground Penetrating Radar (GPR) is frequently used in pavement engineering
for road pavement inspection. The main objective of this work is to validate
nondestructive, quick and powerful measurements using GPR for assessment of subgrade
and asphalt /concrete conditions. In the present study, two different antennas
(250, 500 MHz) were used. The case studies are presented was carried in University
of Baghdad over about 100m of paved road. After data acquisition and radar grams
collection, they have been processed using RadExplorer V1.4 software
implementing different filters with the most effective ones (time zero adjustment and
DC removal) in addition to other interpretation tool parameters.
The interpretatio