Abstract: Cobalt catalysts were supported on extruded silica carrier and different-type (SiO2, γ-Al2O3) commercial supports with different shapes and sizes to produce heavy hydrocarbons for Fischer-Tropsch synthesis. The catalysts were characterized by N2 physisorption and H2-TPR. The catalytic performance of the catalysts was tested in a fixed bed reactor. The results of Fischer-Tropsch synthesis performance showed that the cobalt catalyst supported on spherical silica supports displayed a higher activity and a higher selectivity to C5+ products, due to the fact that the active components were only distributed in the surface layer of spherical carrier, and the influence of gas diffusion restriction on catalytic performance was weakened. Therefore, it can be concluded that the eggshell cobalt catalyst was superior to precious metals modified catalysts in the synthesis of heavy hydrocarbons.
Abstract: This research paper reports on the feasibility and viability of eggshells ash and its effects on the water content and setting time of cement. An experiment was carried out to determine the quantity of water required in order to follow standard cement paste of normal consistency in accordance with MS EN 196-3:2007. The eggshells ash passing the 90µm sieve was used in the investigation. Eggshells ash with percentage of 0%, 0.1%, 0.5%, 1.0%, 1.5% and 2.0% were constituted to replace the cement. Chemical properties of both eggshells ash and cement are compared. From the results obtained, both eggshells ash and cement have the same chemical composition and primary composition which is the calcium compounds. Results from the setting time show that by adding the eggshells ash to the cement, the setting time of the cement decreases. In short, the higher amount of eggshells ash, the faster the rate of setting and apply to all percentage of eggshells ash that were used in this investigation. Both initial and final setting times fulfill the setting time requirements by Malaysian Standard. Hence, it is suggested that eggshells ash can be used as an admixture in concrete mix.
Abstract: Fixed bed adsorption has become a frequently used
industrial application in wastewater treatment processes. Various low
cost adsorbents have been studied for their applicability in treatment
of different types of effluents. In this work, the intention of the study
was to explore the efficacy and feasibility for azo dye, Acid Orange 7
(AO7) adsorption onto fixed bed column of NaOH Treated eggshell
(TES). The effect of various parameters like flow rate, initial dye
concentration, and bed height were exploited in this study. The
studies confirmed that the breakthrough curves were dependent on
flow rate, initial dye concentration solution of AO7 and bed depth.
The Thomas, Yoon–Nelson, and Adams and Bohart models were
analysed to evaluate the column adsorption performance. The
adsorption capacity, rate constant and correlation coefficient
associated to each model for column adsorption was calculated and
mentioned. The column experimental data were fitted well with
Thomas model with coefficients of correlation R2 ≥0.93 at different
conditions but the Yoon–Nelson, BDST and Bohart–Adams model
(R2=0.911), predicted poor performance of fixed-bed column. The
(TES) was shown to be suitable adsorbent for adsorption of AO7
using fixed-bed adsorption column.
Abstract: Freshly laid eggs from green turtles, Chelonia mydas,
were randomly collected from Ras Al-Hadd Reserve, Oman.
Eggshells taken from eggs and sand collected from the body chamber
were analyzed for eight heavy metals (Al, Br, Cd, Co, Cu, Fe, S, and
Zn) using inductively coupled plasma mass spectrometry (ICP).
Heavy metal concentrations varied significantly (P
Abstract: In this study, fish bone waste was used as a new
catalyst for biodiesel production. Instead of discarding the fish bone
waste, it will be utilized as a source for catalyst that can provide
significant benefit to the environment. Also, it can be substitute as a
calcium oxide source instead of using eggshell, crab shell and snail
shell. The XRD and SEM analysis proved that calcined fish bone
contains calcium oxide, calcium phosphate and hydroxyapatite. The
catalyst was characterized using Scanning Electron Microscope
(SEM) and X-ray Diffraction (XRD).
Abstract: In this article, biomechanical aspects of hen-s eggshell as a natural ceramic structure are studied. The images, taken by a scanning electron microscope (SEM), are used to investigate the microscopic aspects of the egg. It is observed that eggshell has a three-layered microstructure with different morphological and structural characteristics. Studies on the eggshell membrane (ESM) as a prosperous tissue suggest that it is placed to prevent the penetration of microorganisms into the egg. Finally, numerical models of the egg are presented to study the stress distribution and its deformation under different loading conditions. The effects of two different types of loading (hydrostatic and point loadings) on two different shell models (with constant and variable thicknesses) are investigated in detail.
Abstract: There are few studies on eggshell of leatherback turtle
which is endangered species in Thailand. This study was focusing on
the ultrastructure and elemental composition of leatherback turtle
eggshells collected from Andaman Sea Shore, Thailand during the
nesting season using scanning electron microscope (SEM). Three
eggshell layers of leatherback turtle; the outer cuticle layer or
calcareous layer, the middle layer or middle multistrata layer and the
inner fibrous layer were recognized. The outer calcareous layer was
thick and porosity which consisted of loose nodular units of various
crystal shapes and sizes. The loose attachment between these units
resulted in numerous spaces and openings. The middle layer was
compact thick with several multistrata and contained numerous
openings connecting to both outer cuticle layer and inner fibrous
layer. The inner fibrous layer was compact and thin, and composed of
numerous reticular fibers. Energy dispersive X-ray microanalysis
detector revealed energy spectrum of X-rays character emitted from
all elements on each layer. The percentages of all elements were
found in the following order: carbon (C) > oxygen (O) > calcium
(Ca) > sulfur (S) > potassium (K) > aluminum (Al) > iodine (I) >
silicon (Si) > chlorine (Cl) > sodium (Na) > fluorine (F) >
phosphorus (P) > magnesium (Mg). Each layer consisted of high
percentage of CaCO3 (approximately 98%) implying that it was
essential for turtle embryonic development. A significant difference
was found in the percentages of Ca and Mo in the 3layers. Moreover,
transition metal, metal and toxic non-metal contaminations were
found in leatherback turtle eggshell samples. These were palladium
(Pd), molybdenum (Mo), copper (Cu), aluminum (Al), lead (Pb), and
bromine (Br). The contamination elements were seen in the outer
layers except for Mo. All elements were readily observed and
mapped using Smiling program. X-ray images which mapped the
location of all elements were showed. Calcium containing in the
eggshell appeared in high contents and was widely distributing in
clusters of the outer cuticle layer to form CaCO3 structure. Moreover,
the accumulation of Na and Cl was observed to form NaCl which was
widely distributing in 3 eggshell layers. The results from this study
would be valuable on assessing the emergent success in this
endangered species.