Higher College of Technology

About: Higher College of Technology is a based out in . It is known for research contribution in the topics: Higher education & Tourism. The organization has 369 authors who have published 379 publications receiving 729 citations.

Detailed manufacturing process of a tubular carbon microfiltration membrane for industrial wastewater treatment

Abstract: This paper discusses the preparation of an asymmetric microfiltration carbon membrane made of mineral coal powder and phenolic resin. Tubular supports were obtained via extrusion of a paste prepared by mixing a carbon powder, a solution of phenolic resin and organic additives. The green tubes were cured then carbonized at 700 °C under nitrogen flow. Porous supports with an average pore diameter of 9 μm and 38% porous volume were achieved. The material presents high chemical and mechanical resistances. Experimental data showed that the particle size and homogeneity of the carbon powder are directly responsible of the average pore size and distribution of the final material. Phenolic resin acts as binder, carbon precursor and porosity agent with a constant 25% contribution to the total porous volume. The microfiltration layer was coated by means of the slip casting process, using a suspension of finely ground carbon powder dispersed in a phenolic resin alcoholic solution. Carbonization at 700 °C was necessary to obtain a defect-free layer with an average pore diameter of 0.5 and 25 μm thickness. The membrane material displayed a hydrophobic character. To increase its hydrophilic character, the membrane was oxidized under air at 350 °C for 30 min then tested for industrial wastewater filtration. The membrane’s behavior complied with the Darcy’s law even after oxidation. Nevertheless, the oxidation step changed the hydrophobic character of the membrane to a hydrophilic one. In fact, this treatment had a direct impact on the permeability of the membrane and on the filtration flux of industrial wastewater. The latter increased by a factor of 2.5 to 5. In addition, a total retention in turbidity was achieved with 47% of the organic matter retained by the membrane. Due to a complexation between the organic elements Ca2+ and Mg2+, the retention of these divalent ions was also important.

Denoising of Multispectral Images: An Adaptive Approach

Abstract: Spectral imaging enables detection of external details not processed by the human eye through its red, green, and blue receptors. Multispectral imaging aims to collect the range in a scene picture for each pixel and provide more accurate detail. Different noises eventually compromise Multispectral Image (MSI) due to hardware constraints and insufficiency in radiance. Hence, to enhance the quality of image, we proposed Kriging Interpolation-based Wiener Filtering (KIWF). This makes use of kriging interpolation algorithm to calculate the weights of wiener filter so that the best possible estimate is obtained for denoising the image. Initially, the pixels with noise are separated from clear pixels by global patch clustering, and the weight values are applied by estimating the semi-variance between the clear patches and noisy patches. Finally, the performance of the filter is tested and a comparative analysis is conducted with the existing denoising techniques to show its effectiveness.

Musa Acuminata Leaves Extract Impedes Bacterial Growth and Ultraviolet Protection in Cotton Fabric

Abstract: In this study, the methanol extract of Musa acuminate leaves has a significant development on the quality of the protection features such as, antibacterial and ultraviolet protection, was observed....

Pretreatment and acid hydrolysis of Omani Prosopis juliflora wood

Abstract: The objective of this research is to investigate different chemical pretreatment methods to reduce lignin and hemicellulose content of Omani Prosopis juliflora. The pretreated wood will then be acid hydrolysed to convert the cellulose content to sugar. Four types of pretreatment methods was employed namely: Alkaline pretreatment (Method I), Alkaline + Hydrogen peroxide pretreatment (Method II), Alkaline + Hydrogen peroxide + acid-chlorite pretreatment (Method III) and Alkaline + H2O2 + Acid-chlorite + bicarbonate pretreatment (Method IV). The effectiveness of each pretreatment method was assessed by measuring lignin, hemicellulose, and cellulose contents and the crystallinity index (CrI) using X-ray diffraction (XRD) analysis. The results were further assessed by taking images of the wood samples after each pretreatment step using Scanning Electron Microscope (SEM). The results showed that the CrI increases from 51% for the untreated samples to 61%, 65%, 68% and 73.2% after treating with Method I, II, III and IV respectively. Measuring the cellulose, hemicellulose and lignin contents showed that the effectiveness of the methods in ascending order was Method I The pretreated wood samples by method IV were acid hydrolysed. The effect of acid type namely: H2SO4, HNO3, HCl and H3PO 4 , concentration and hydrolysis time on the %conversion of cellulose to sugar was investigated. The results revealed that H2SO4 was the most effective acid whereas H3PO 4 was the weakest. The efficiency of the tested acids follow the following order: H2SO4 > HNO3 > HCL > H3PO 4 . For all acids tested, the %conversion of cellulose to reducing sugar as a function of time increases linearly till t = 90 min after which no change in the %conversion was obtained. Investigating the effect of acid concentration showed that as the concentration increases the %conversion increases too. Upon increasing acid concentration from 1% to 10%, the %conversion increases from 12% to 62% for H2SO4, from 5% to 43% for HNO3, from 0% to 47% for HCl, and from 5% to 34% for H3PO4.

Experimental Investigations and Concise Review on Biodiesel Production from Crude Sunflower Oil Using Lime-Based Catalysts

Abstract: Biodiesel is a renewable and clean-burning fuel used as a substitute for petroleum diesel. Biodiesel, as a biofuel, increases energy security and environment quality and provides safety benefits. The objective of this chapter is to study the effectiveness of various lime-based materials as catalysts for the preparation of biodiesel from crude sunflower oil through transesterification with methanol and ethanol. First, biodiesel was prepared from pure sunflower oil using methanol and NaOH as a catalyst. Then, biodiesel was prepared from pure sunflower oil using ethanol and rejected lime as a catalyst. Later, biodiesel was prepared from crude sunflower oil using methanol and various lime-based materials such as rejected lime, pure lime, and limestone as catalysts. Biodiesel was checked for its properties such as free fatty acid, density, dynamic viscosity, kinematic viscosity, flash and fire points, and cloud and pour points. From the results, it was found that pure lime is the suitable catalyst for the production of biodiesel from crude sunflower oil. A concise review on biodiesel production using lime-based materials as a catalyst was also presented.