| 1. |
- Al-Maliki, Laheab A., et al.
(författare)
-
Perceptions about water pollution among university students : A case study from Iraq
- 2021
-
Ingår i: Cogent Engineering. - UK : Taylor & Francis. - 2331-1916. ; 8:1
-
Tidskriftsartikel (refereegranskat)abstract
- This study intends to evaluate university students’ awareness regarding water pollution in Iraq to show the environmental education contribution in reducing water pollution. The study was conducted in Wasit university, Wasit province, Iraq by field questionnaire survey with 388 students from the civil engineering department and engineering college. The questionnaires were divided according to the pollution causes into industrial, agricultural and sewage water pollutants. The data were analyzed utilizing the thematic analysis to assess environmental knowledge and awareness of water pollution risks. The results show that most students have high interest in environmental conservation, yet, a lack of education in general environmental education, as the educational curriculum focuses on theoretical aspects more than the practical ones. The results also show that the media role is inactive concerning environmental awareness of water pollution. This study provides a scientific view of policymakers for potential future conditions to find solutions that achieve sustainability goals.
|
|
| 2. |
|
|
| 3. |
|
|
| 4. |
|
|
| 5. |
- Ansari, Farhan, et al.
(författare)
-
Cellulose nanocomposites - Controlling dispersion and material properties through nanocellulose surface modification
- 2015
-
Ingår i: 20th International Conference on Composite Materials, ICCM 2015. - : International Committee on Composite Materials.
-
Konferensbidrag (refereegranskat)abstract
- The use of cellulosic nanofibers as reinforcement in polymer composites offers great advantages over their petroleum counterparts. Apart from being strong, stiff and low density; they are obtained from naturally occurring resources and as such are favorable from an environmental point of view. A major problem while studying nanomaterials is their tendency to agglomerate, thus leading to inhomogeneous distribution within the polymer matrix. This often results in stress concentrations in the matrix rich regions when the material is subjected to load and therefore, limits the potential application of these materials. A common approach to circumvent this is by surface modification, which facilitates the dispersion in non-polar matrices. An environmental friendly approach, inspired by clay chemistry, was used to functionalize the CNC surface. It was shown that the CNC could be modified in a rather convenient way to attach a variety of functional groups on the surface. Primarily, the problem of cellulose nanocrystal (CNC) distribution in a hydrophobic polymer matrix is investigated. Composites prepared from modified CNC were studied and compared with unmodified CNC. The distribution of the CNC is carefully monitored at different stages via UV-Vis spectroscopy and scanning electron microscopy (SEM). The mechanical properties of the resulting materials were characterized by dynamic mechanical as well as uniaxial tensile tests. It was shown that a homogeneous distribution of the CNC exposes a tremendous amount of surface area to interact with the matrix. In such a case, the stress transfer is much more efficient and perhaps, the matrix behavior is modified, which leads to significant improvements in the mechanical properties.
|
|
| 6. |
- Ansari, Farhan, et al.
(författare)
-
Cellulose nanofiber network for moisture stable, strong and ductile biocomposites and increased epoxy curing rate
- 2014
-
Ingår i: Composites. Part A, Applied science and manufacturing. - : Elsevier BV. - 1359-835X .- 1878-5840. ; 63, s. 35-44
-
Tidskriftsartikel (refereegranskat)abstract
- Nanocomposites with high volume fractions (15-50 vol%) of nanofibrillated cellulose (NFC) were prepared by impregnation of a wet porous NFC network with acetone/epoxy/amine solution. Infrared spectroscopy studies revealed a significant increase in curing rate of epoxy (EP) in the presence of NFC. The NFC provided extremely efficient reinforcement (at 15 vol%: 3-fold increase in stiffness and strength to 5.9 GPa and 109 MPa, respectively), and ductility was preserved. Besides, the glass transition temperature increased with increasing NFC content (from 68 degrees C in neat epoxy to 86 degrees C in 50 vol% composite). Most interestingly, the moisture sorption values were low and even comparable to neat epoxy for the 15 vol% NFC/EP. This material did not change mechanical properties at increased relative humidity (90% RH). Thus, NFC/EP provides a unique combination of high strength, modulus, ductility, and moisture stability for a cellulose-based biocomposite. Effects from nanostructural and interfacial tailoring are discussed.
|
|
| 7. |
|
|
| 8. |
|
|
| 9. |
- Ansari, Farhan, et al.
(författare)
-
Experimental evaluation of anisotropy in injection molded polypropylene/wood fiber biocomposites
- 2017
-
Ingår i: Composites. Part A, Applied science and manufacturing. - : Elsevier. - 1359-835X .- 1878-5840. ; 96, s. 147-154
-
Tidskriftsartikel (refereegranskat)abstract
- Although the anisotropy of wood fibers is reasonably well established, the anisotropy of injection molded wood fiber composites is not well understood. This work focuses on chemo-thermomechanical pulp (CTMP) reinforced polypropylene (PP) composites. A kinetic mixer (Gelimat) is used for compounding CTMP/PP composites, followed by injection molding. Effects from processing induced orientation on mechanical properties are investigated. For this purpose, a film gate mold was designed to inject composites in the shape of plates so that specimens in different directions to the flow could be evaluated. Observations from tensile tests were complemented by performing flexural tests (in different directions) on discs cut from the injected plates. SEM was used to qualitatively observe the fiber orientation in the composites. At high fiber content, both modulus and tensile strength could differ by as much as 40% along the flow and transverse to the flow. The fiber orientation was strongly increased at the highest fiber content, as concluded from theoretical analysis.
|
|
| 10. |
- Ansari, Farhan, et al.
(författare)
-
Hierarchical wood cellulose fiber/epoxy biocomposites : Materials design of fiber porosity and nanostructure
- 2015
-
Ingår i: Composites. Part A, Applied science and manufacturing. - : Elsevier BV. - 1359-835X .- 1878-5840. ; 74, s. 60-68
-
Tidskriftsartikel (refereegranskat)abstract
- Delignified chemical wood pulp fibers can be designed to have a controlled structure of cellulose fibril aggregates to serve as porous templates in biocomposites with unique properties. The potential of these fibers as reinforcement for an epoxy matrix (EP) was investigated in this work. Networks of porous wood fibers were impregnated with monomeric epoxy and cured. Microscopy images from ultramicrotomed cross sections and tensile fractured surfaces were used to study the distribution of matrix inside and around the fibers - at two different length scales. Mechanical characterization at different relative humidity showed much improved mechanical properties of biocomposites based on epoxy-impregnated fibers and they were rather insensitive to surrounding humidity. Furthermore, the mechanical properties of cellulose-fiber biocomposites were compared with those of cellulose-nanofibril (CNF) composites; strong similarities were found between the two materials. The reasons for this, some limitations and the role of specific surface area of the fiber are discussed.
|
|
