Biodiesel can be prepared from various types of vegetable oils or animal fats with the aid of a catalyst.
Calcium oxide (CaO) is one of the prospective heterogeneous catalysts for biodiesel synthesis. Modification
of CaO by impregnation on silica (SiO2) can improve the performance of CaO as catalyst. Egg shells and rice
husks as biomass waste can be used as raw materials for the preparation of the silica modified CaO catalyst.
The present study was directed to synthesize and characterize CaO impregnated SiO2 catalyst from biomass
waste and apply it as catalyst in biodiesel synthesis. The catalyst was synthesized by wet impregnation
method and characterized by x-ray diffraction, x-ray fluorescence, nitrogen adsorption-desorption, and
basicity density. The activity of the catalyst in biodiesel synthesis was assayed at different molar ratios of
palm oil to methanol ranging from 1:6, 1:9, 1:12 and 1:15. The biodiesel composition was determined by gas
chromatography-mass spectroscopy and the properties of the biodiesel were also characterized. The results
showed that the CaO impregnated SiO2 catalyst was successfully synthesized based on confirmation by XRD
and XRF. The catalyst has a surface area, average pore diameter, total pore volume, and basicity density of
19.38 m2
/g, 3.22 nm, 0.0122 cm3
/g, and 3.4 mmol/g, respectively. The catalyst activity assay indicates that
the molar ratio of palm oil to methanol of 1:12 is the optimum condition for biodiesel synthesis. At this
molar ratio, 81.4% biodiesel yield was achieved, and it met the quality standards according to ASTM D
6751.
This research aims to predict the value of the maximum daily loss that the fixed-return securities portfolio may suffer in Qatar National Bank - Syria, and for this purpose data were collected for risk factors that affect the value of the portfolio represented by the time structure of interest rates in the United States of America over the extended period Between 2017 and 2018, in addition to data related to the composition of the bonds portfolio of Qatar National Bank of Syria in 2017, And then employing Monte Carlo simulation models to predict the maximum loss that may be exposed to this portfolio in the future. The results of the Monte Carlo simulation showed the possibility of decreasing the value at risk in the future due to the dec
... Show MoreMn2O3 was coated onto reduced titania nanotubes by reverse pulse electrodeposition, showing smooth and homogenous deposits without covering the opening of the nanotubes.
Background: The present in-vitro study was undertaken to evaluate and compare fracture resistance of weakened endodontically treated premolars with class II MOD cavities restored with different bulk fill composite restorations (EverX posterior, Alert, Tetric EvoCeram Bulk Fill, and SDR). The type and mode of fracture were also assessed for all the experimental groups. Materials and Method: Forty-eight human adult maxillary premolar teeth were selected for this study. Standardized extensive class II MOD cavities with endodontic treatment were prepared for all teeth, except those that were saved as intact control. The teeth were divided into six groups of eight teeth each (n=8): (Group 1) intact control group, (Group 2) unrestored teeth with
... Show MoreThe research aims to monitor the methods of Counter psychological warfare in the Iraqi press during the operations to liberate Mosul from the control of the terrorist organization ISIS.The research used the survey method, and “Tareek Al Shaab” Newspaper as a research sample, chosen according to the systematic random sample.
The research reached the following results:
1- The Communicator’s relied on the contents of the counter-psychological warfare and its methods in the battle of “Qadimun Ya Naynawa” used in the newspaper. The methods used were labels assigning such as : inevitable victory, prodding and morale, consensus, breaking of opposition morale, stereotyping, demonization of the opponent
Objectives: This study aims to assess and compare the micro-shear bond strength (μSBS) of a novel resin-modified glass-ionomer luting cement functionalized with a methacrylate co-monomer containing a phosphoric acid group, 30 wt% 2-(methacryloxy) ethyl phosphate (2-MEP), with different substrates (dentin, enamel, zirconia, and base metal alloy). This assessment is conducted in comparison with conventional resin-modified glass ionomer cement and self-adhesive resin cement. Materials and methods: In this in vitro study, ninety-six specimens were prepared and categorized into four groups: enamel (A), dentin (B), zirconia (C), and base metal alloys (D). Enamel (E) and dentin (D) specimens were obtained from 30 human maxillary first premolars e
... Show MoreKE Sharquie, AA Noaimi, BAM Saleh, 2015
This research is based on monitoring the local and environmental technologies in the design of the temporary hotel units (nomadic tents) in the desert in the south of Jordan in order to air condition them in summer and winter, maintaining the Jordanian identity, that they are presented with the form and technologies of the age in order to get to the universality.
The research adopted the descriptive analytical method and the researcher conducted the analysis of SWOT specified for the analysis of the positive and negative aspects in the design of the temporary hotel units and comparing them with the case studies available in the chosen research area "the Jordanian golden triangle", through the elements of the case under study. The res
This research discusses the verbal follow phenomenon in Al-Amali Abi Al-Qali’s book (seq.356 Hijri). It aims to limit the examples of this phenomenon in the book, and examine it phonologically. Accordingly, the researcher adopted the analaytical descriptive approach, taking into account Al-Rawi’s letter when ordering the verbal follow-based examples, and the order they took in the book in question. The purposes behind this phonological study of verbal follow in Al-Amali’s book are to: reach the sounds which Arabs prefer in the process of following, confirm different beautiful and desirable senses, have easy and speedy pronunciation, maintain harmony between adjacent sounds, count the sounds that occur at the beginning of the
... Show MoreDue to the large size of dealing in the transactions installment sales in durable products, especially real estate given the privacy to enjoy their property, among other products because of the large amount and the length of the repayment period leading to a risk of non-payment by the buyer because of the possibility to change the credit level to him, especially that most of this type of transaction customers are from limited income owners, So it has been proposed the use of other transactions in handling real estate instead of installment sales transactions, a rental sale transactions because of the protection provided by this transaction for a vendor that will be mentioned later.
So proposes to st
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