The use of inert porous media based reactors for hydrogen production

The present review paper examines the production of hydrogen in inert porous media based reformer by thermal partial oxidation. Here we consider, specifically, the rich combustion of hydrocarbon fuels and the conversion of H₂S to hydrogen. The different technologies to produce hydrogen beside the experimental and numerical work done in this field are presented. The effect of different operating conditions, such as the equivalence ratio, the mass flow rate and the reactant feed temperature are explained. Additionally, design parameters, including the reactor geometry and porous material specifications, are discussed.     

Recognition of Handwritten Arabic Characters using Histograms of Oriented Gradient (HOG)

Optical Character Recognition (OCR) is the process of recognizing printed or handwritten text on paper documents. This paper proposes an OCR system for Arabic characters. In addition to the preprocessing phase, the proposed recognition system consists mainly of three phases. In the first phase, we employ word segmentation to extract characters. In the second phase, Histograms of Oriented Gradient (HOG) are used for feature extraction. The final phase employs Support Vector Machine (SVM) for classifying characters. We have applied the proposed method for the recognition of Jordanian city, town, and village names as a case study, in addition to many other words that offers the characters shapes that are not covered with Jordan cites. The set has carefully been selected to include every Arabic character in its all four forms. To this end, we have built our own dataset consisting of more than 43.000 handwritten Arabic words (30000 used in the training stage and 13000 used in the testing stage). Experimental results showed a great success of our recognition method compared to the state of the art techniques, where we could achieve very high recognition rates exceeding 99%.     

Multiple source imagery and linear features for detection of urban expansion in Aqaba City,Jordan

Aqaba is one of the most strategic cities in Jordan and the entire region, as it is the only seaport for Jordan and has a special economic zone as the only window to global markets. The main purpose of this study is to detect urban development in Aqaba region by detecting and registering linear features in images with various geometric and radiometric properties taken at different times. This article used linear features for image registration that were chosen since they can be reliably extracted from imagery with significantly different geometric and radiometric properties. The modified iterated Hough transform (MIHT) is used as the matching strategy for automatically deriving an estimate of the parameters involved in the transformation function relating the images to be registered as well as the correspondence between conjugate lines. Derived edges from the registered images are used as the basis for change detection. The utilization of edges is motivated by the fact that they are invariant with respect to possible radiometric differences between the images in question. Linear features extraction, feature matching, image registration and pixel–pixel subtraction have been implemented using SPOT, Landsat, Ikonos and aerial photographs that have different radiometric, spatial and temporal resolutions. It has been shown that linear features (straight-line segments) have high semantics and can be reliably extracted from the images. These linear features can be used for accurate co-registration as an essential prerequisite for a reliable change detection procedure. For the purpose of change detection, image–image registration is more crucial than image–ground registration, where corresponding features in images are registered with respect to each other regardless of the associated absolute errors. The results illustrate that using edges as the base for change detection in urban areas is efficient and reliable.     

A comprehensive review of nanofiltration membranes:Treatment, pretreatment, modelling, and atomic force microscopy

Nanofiltration membranes (NF) have applications in several areas. One of the main applications has been in watertreatment for drinking water production as well as wastewater treatment. NF can either be used to treat all kinds of water including ground, surface, and wastewater or used as a pretreatment for desalination. The introduction of NF as a pretreatment is considered a breakthrough for the desalination process. NF membranes have been shown to be able to remove turbidity, microorganisms and hardness, as well as a fraction of the dissolved salts. This results in a significantly lower operating pressure and thus provides a much more energy-efficient process. Similar to other membrane processes, a major problem in NF membrane applications is fouling. Several studies have investigated the mechanisms of fouling in NF membranes and suggested methods to minimize and control the fouling of NF membranes. For NF membrane characterizations and process prediction, modeling of NF processes and the use of atomic force microscopy (AFM) are very important. The ability to predict the performance of NF processes will lead to a lower number of experiments, saving of time and money, and help to understand the separation mechanisms during NF. A comprehensive review of NF in water treatments is presented including a review of the applications of NF in treating water as well as in the pretreatment process for desalination; the mechanism as well as minimization of NF membrane fouling problems; and theories for modelling and transport of salt, charged and noncharged organic compounds in NF membranes. The review will also address the application of AFM in studying the morphology of membrane surfaces as part of the NF membrane characterization.     

Electroosmotic Dewatering of Tomato Paste Suspension Under AC Electric Field

Laboratory tests have demonstrated electroosmosis under an alternate current (AC) to be effective for dewatering tomato paste suspension. Application of an alternate current (AC) field provided more promising results than those of direct current (DC) electrical field. The results show that the electroosmotic dewatering is influenced by the wave form (sine, rectangular, triangular). The decrease in the wave frequency resulted in an increase in the dewatering rate, whereas increasing the initial bed height increased the dewatering rate.