Showing 5 results for Absorption
F. Salehtash, H. Banna Motejadded Emrooz, M. Jalaly,
Volume 15, Issue 2 (6-2018)
Abstract
Mesoporous SiO2 nanopowder was synthesized under an acidic condition by a sol-gel method using various amounts of cetyltrimethyl ammonium bromide (CTAB) as structure directing agent. The samples were investigated with XRD, SEM, FTIR, TEM and N2 absorption-desorption analysis. Also, the incremental effect of surfactant were examined. The results obtained from the analysis suggested that an increase in the amount of surfactant resulted in increasing specific surface area, pore size and pore volume, of the synthesized particles up to 549 m2.g-1, 17.3 nm, and 2 cm3.g-1, respectively. Absorption behavior of the mesoporous silica was investigated for degradation of methylene blue pigments (MB) in aqueous solutions. The samples SC0, SC0.5 and SC1 showed the maximum absorption capacities of 333, 454 and 526 mg/g, respectively
A. Allahverdi, Z. Padar, M. Mahinroosta,
Volume 16, Issue 2 (6-2019)
Abstract
It is demonstrated that the addition of organo-modified Na-bentonite (OMB) particles to Portland cement mortar can promote its physical and mechanical properties. A series of experimental works on some important physico-mechanical properties of Portland cement mortars mixed with various dosages of hydrophobic OMB were performed. The obtained results confirm that the OMB provides a dense packing effect. An optimum replacement level of around 3.5% (by weight) at an increased water-to-cement ratio of 0.53 results in an almost 11.43% increase in 28-day compressive strength along with about 20.78 and 16.20% reductions in total volume of permeable pore space and water absorption, respectively. Also, at the optimum replacement level, an increase of about 2.72% is taken place in dry bulk specific gravity.
Mohammad Ali Maghsoudlou, Reza Barbaz Isfahani, Saeed Saber-Samandari, Mojtaba Sadighi,
Volume 18, Issue 2 (6-2021)
Abstract
The low velocity impact (LVI) response of pure and glass fiber reinforced polymer composites (GFRP) with 0.1, 0.3 and 0.5 wt% of functionalized single-walled carbon nanotubes (SWCNTs) was experimentally investigated. LS-DYNA simulation was used to model the impact test of pure and incorporated GFRP with 0.3 wt% of SWCNT in order to compare experimental and numerical results of LVI tests. All tests were performed in two different levels of energy. In 30J energy, the specimen containing 0.5 wt% SWCNT was completely destructed. The results showed that the incorporated GFRP with 0.3 wt% SWCNT has the highest energy absorption and the back-face damage area of this sample was smaller than other specimens. TEM images from specimens were also analyzed and showed the incorporation of well-dispersed 0.1 and 0.3 wt% of SWCNT, while in specimens containing 0.5 wt% of CNT, tubes tended to be agglomerated which caused a drop in LVI response of the specimen. The contact time of impactor in numerical and experimental results was approximately equal; however, the maximum contact forces in LS DYNA simulation results were higher than the experimental results which could be due to the fact that in the numerical modeling, properties are considered ideal, unlike in experimental conditions.
Raghad Hadi, Furqan Almyahi,
Volume 21, Issue 0 (3-2024)
Abstract
In this investigation, a formulation was developed as a solution and thin films by combining poly (3-hexylthiophene) (P3HT) and fullerene Indene-C60 multi-adducts (ICxA) with varying solvent ratios. The formulations were prepared under ambient conditions. Morphological parameters were assessed utilizing a transmission electron microscope, scanning electron microscope and complemented by optical microscope pictures. UV-Visible absorbance and photoluminescence (PL) measurements were implemented to investigate the optical properties of active layers The values of the energy gaps of the prepared thin films and solutions increased as the solvent ratios of chlorobenzene to stander solvent increased, as a result of the isolation of P3HT chains from their neighbours. The Raman spectra are associated with high aggregation of composition and increased conformation when the intensity ratio (IC= C/IC-C) is small and the full width at high maximum (FWHM) is low. In ambient conditions, organic photovoltaic cells (OPVs) are produced with varying solvent ratios. The device with a 30% ratio exhibited the highest performance, with a power conversion efficiency (PCE) of approximately 1%, an open circuit voltage (VOC) of 0.571 V, a short circuit current density (JSC) of 7.47 mA.cm-2, and a fill factor (FF) of 38.6%.
Fathi Brioua, Chouaib Daoudi,
Volume 21, Issue 2 (6-2024)
Abstract
We have modeled theoretical incident photon-to-current electricity (IPCE) action spectra of poly(3-hexylthiophene) (P3HT) and [6,6]-Phenyl C61 butyric acid methyl ester active layer bulk-heterojunction. By the two-dimensional optical model of a multilayer system based on the structure of Glass substrate / SiO2 /ITO/ PEDOT: PSS /P3HT: PCBM(1:1)/Ca/Al, the optical responses of the device have been computed for different photoactive layer and Ca layer thicknesses to found an optimal structure which allows obtaining the maximum absorption localized in the active layer and high device performance. The electric field intensity, energy dissipation, generation rate, and IPCE have been computed to enhance the device's performance. The finite element method executes the simulation under an incident intensity of 100 mW/cm2 of the 1.5 AM illumination. It was found that the optimum structure is achieved by a 180 nm photoactive layer and 5 nm Ca layer thicknesses.
