Steady State Simulation and Experimental Study of an Ethane Recovery Unit in an Iranian Natural Gas Refinery

The production and consumption of natural gas is on the rise throughout the world as a result of its wide availability, ease of transportation, use and clean-burning characteristics. The chief use of ethane is in the chemical industry in the production of Ethene (ethylene) by steam cracking. In this simulation, obtained ethane recovery percent based on Gas sub-cooled process (GSP) is 99.9 by mole that is included 32.1% by using de-methanizer column and 67.8% by de-ethanizer tower. The outstanding feature of this process is the novel split-vapor concept that employs to generate reflux for de-methanizer column. Remain amount of ethane in export gas cause rise in gross heating value up to 36.66 MJ/Nm3 in order to use in industrial and household consumptions.

The Recreation Technique Model from the Perspective of Environmental Quality Elements

The quality improvements of the environmental elements could increase the recreational opportunities in a certain area (destination). The technique of the need for recreation focuses on choosing certain destinations for recreational purposes. The basic exchange taken into consideration is the one between the satisfaction gained after staying in that area and the value expressed in money and time allocated. The number of tourists in the respective area, the duration of staying and the money spent including transportation provide information on how individuals rank the place or certain aspects of the area (such as the quality of the environmental elements). For the statistical analysis of the environmental benefits offered by an area through the need of recreation technique, the following stages are suggested: - characterization of the reference area based on the statistical variables considered; - estimation of the environmental benefit through comparing the reference area with other similar areas (having the same environmental characteristics), from the perspective of the statistical variables considered. The model compared in recreation technique faced with a series of difficulties which refers to the reference area and correct transformation of time in money.

Numerical Studies on Flow Field Characteristics of Cavity Based Scramjet Combustors

The flow field within the combustor of scramjet engine is very complex and poses a considerable challenge in the design and development of a supersonic combustor with an optimized geometry. In this paper comprehensive numerical studies on flow field characteristics of different cavity based scramjet combustors with transverse injection of hydrogen have been carried out for both non-reacting and reacting flows. The numerical studies have been carried out using a validated 2D unsteady, density based 1st-order implicit k-omega turbulence model with multi-component finite rate reacting species. The results show a wide variety of flow features resulting from the interactions between the injector flows, shock waves, boundary layers, and cavity flows. We conjectured that an optimized cavity is a good choice to stabilize the flame in the hypersonic flow, and it generates a recirculation zone in the scramjet combustor. We comprehended that the cavity based scramjet combustors having a bearing on the source of disturbance for the transverse jet oscillation, fuel/air mixing enhancement, and flameholding improvement. We concluded that cavity shape with backward facing step and 45o forward ramp is a good choice to get higher temperatures at the exit compared to other four models of scramjet combustors considered in this study.

A New Approach for the Fingerprint Classification Based On Gray-Level Co- Occurrence Matrix

In this paper, we propose an approach for the classification of fingerprint databases. It is based on the fact that a fingerprint image is composed of regular texture regions that can be successfully represented by co-occurrence matrices. So, we first extract the features based on certain characteristics of the cooccurrence matrix and then we use these features to train a neural network for classifying fingerprints into four common classes. The obtained results compared with the existing approaches demonstrate the superior performance of our proposed approach.

Seismic Behaviour of Steel Frames Investigation with Knee Brace Based on Pushover Analysis

The knee bracing steel frame (KBF) is a new kind of energy dissipating frame, which combines excellent ductility and lateral stiffness. In this framing system, a special form of diagonal brace connected to a knee element instead of beam-column joint, is investigated. Recently, a similar system was proposed and named as chevron knee bracing system (CKB) which in comparison with the former system has a better energy absorption characteristic and at the same time retains the elastic nature of the structures. Knee bracing can provide a stiffer bracing system but reduces the ductility of the steel frame. Chevron knee bracing can be employed to provide the desired ductility level for a design. In this article, relation between seismic performance and structural parameters of the two above mentioned systems are investigated and compared. Frames with similar dimensions but various heights in both systems are designed according to Iranian code of practice for seismic resistant design of building, and then based on a non-linear push over static analysis; the seismic parameters such as behavior factor and performance levels are compared.

Numerical Investigation of High Attack Angle Flow on 760/450 Double-Delta Wing in Incompressible Flow

Along with increasing development of generation of supersonic planes especially fighters and request for increasing the performance and maneuverability scientists and engineers suggested the delta and double delta wing design. One of the areas which was necessary to be researched, was the Aerodynamic review of this type of wings in high angles of attack at low speeds that was very important in landing and takeoff the planes and maneuvers. Leading Edges of the wings,cause the separation flow from wing surface and then formation of powerful vortex with high rotational speed which studing the mechanism and location of formation and also the position of the vortex breakdown in high angles of attack is very important. In this research, a double delta wing with 76o/45o sweep angles at high angle of attack in steady state and incompressible flow were numerically analyzed with Fluent software. With analaysis of the numerical results, we arrived the most important characteristic of the double delta wings which is keeping of lift at high angles of attacks.

The Effect of Cyclone Shape and Dust Collector on Gas-Solid Flow and Performance

Numerical analysis of flow characteristics and separation efficiency in a high-efficiency cyclone has been performed. Several models based on the experimental observation for a design purpose were proposed. However, the model is only estimated the cyclone's performance under the limited environments; it is difficult to obtain a general model for all types of cyclones. The purpose of this study is to find out the flow characteristics and separation efficiency numerically. The Reynolds stress model (RSM) was employed instead of a standard k-ε or a k-ω model which was suitable for isotropic turbulence and it could predict the pressure drop and the Rankine vortex very well. For small particles, there were three significant components (entrance of vortex finder, cone, and dust collector) for the particle separation. In the present work, the particle re-entraining phenomenon from the dust collector to the cyclone body was observed after considerable time. This re-entrainment degraded the separation efficiency and was one of the significant factors for the separation efficiency of the cyclone.

Mobility Analysis of the Population of Rabat-Salé-Zemmour-Zaer

In this paper, we present the 2006 survey study origin destination and price that we carried out during 2006 fall in the area in the Moroccan region of Rabat-Salé-Zemmour-Zaer. The survey concerns the people-s characteristics, their displacements behavior and the price that they will be able to pay for a tramway ticket. The main objective is to study a set of relative features to the households and to their displacement's habits and to their choices among public and privet transport modes. A comparison between this survey results and that of the 1996's is made. A pricing scheme is also given according to the tram capacity. (The Rabat-Salé tramway is under construction right now and it will be operational beginning 2010).

Effect of Chemical Pretreatments and Dehydration Methods on Quality Characteristics of Tomato Powder and Its Storage Stability

Dehydration process was carried out for tomato slices of var. Avinash after giving different pre-treatments such as calcium chloride (CaCl2), potassium metabisulphite (KMS), calcium chloride and potassium metabisulphite (CaCl2 +KMS), and sodium chloride (NaCl). Untreated samples served as control. Solar drier and continuous conveyor (tunnel) drier were used for dehydration. Quality characteristics of tomato slices viz. moisture content, sugar, titratable acidity, lycopene content, dehydration ratio, rehydration ratio and non-enzymatic browning as affected by dehydration process were studied. Storage study was also carried out for a period of six months for tomato powder packed into different types of packaging materials viz. metalized polyester (MP) film and low density poly ethylene (LDPE). Changes in lycopene content and non-enzymatic browning (NEB) were estimated during storage at room temperature. Pretreatment of 5 mm thickness of tomato slices with calcium chloride in combination with potassium metabisulphite and drying using a tunnel drier with subsequent storage of product in metalized polyester bags was selected as the best process.

The Synergistic Effects of Using Silicon and Selenium on Fruiting of Zaghloul Date Palm (Phoenix dectylifera L.)

During 2011 and 2012 seasons, Zaghloul date palms received four sprays of silicon (Si) at 0.05 to 0.1% and selenium (Se) at 0.01 to 0.02%. Growth, nutritional status, yield as well as physical and chemical characteristics of the fruits in response to application of silicon and selenium were investigated. Single and combined applications of silicon at 0.05 to 0.1% and selenium at 0.01 to 0.02% was very effective in enhancing the leaf area, total chlorophylls, percentages of N, P and K in the leaves, yield, bunch weight as well as physical and chemical characteristics of the fruits in relative to the check treatment. Silicon was superior to selenium in this respect. Combined application was favorable than using each alone in this connection. Treating Zaghloul date palms four times with a mixture of silicon at 0.05% + selenium at 0.01% resulted in an economical yield and producing better fruit quality.

MIMO Performances in Tunnel Environment: Interpretation from the Channel Characteristics

The objective of this contribution is to study the performances in terms of bit error rate, of space-time code algorithms applied to MIMO communication in tunnels. Indeed, the channel characteristics in a tunnel are quite different than those of urban or indoor environment, due to the guiding effect of the tunnel. Therefore, MIMO channel matrices have been measured in a straight tunnel, in a frequency band around 3GHz. Correlation between array elements and properties of the MIMO matrices are first studied as a function of the distance between the transmitter and the receiver. Then, owing to a software tool simulating the link, predicted values of bit error rate are given for VLAST, OSTBC and QSTBC algorithms applied to a MIMO configuration with 2 or 4 array elements. Results are interpreted from the analysis of the channel properties.

Free Convective Heat Transfer in an Enclosure Filled with Porous Media with and without Insulated Moving Wall

The present work is concerned with the free convective two dimensional flow and heat transfer, in isotropic fluid filled porous rectangular enclosure with differentially heated walls for steady state incompressible flow have been investigated for non- Darcy flow model. Effects of Darcy number (0.0001 £Da£ 10), Rayleigh number (10 £Ra£ 5000), and aspect ratio (0.25 £AR£ 4), for a range of porosity (0.4 £e£ 0.9) with and without moving lower wall have been studied. The cavity was insulated at the lower and upper surfaces. The right and left heated surfaces allows convective transport through the porous medium, generating a thermal stratification and flow circulations. It was found that the Darcy number, Rayleigh number, aspect ratio, and porosity considerably influenced characteristics of flow and heat transfer mechanisms. The results obtained are discussed in terms of the Nusselt number, vectors, contours, and isotherms.

Behavior of RC Buildings to Tsunami Action

The present report describes the characteristics of damages and behavior of reinforced concrete buildings during the tsunami action. The discussion is based on the field damage survey in selected cities located on the coast of the zone affected by the Great East Japan Earthquake on March 11, 2011. This earthquake is the most powerful know earthquake that has hit Japan with a magnitude 9.0 and with epicenter located at 129 km of Sendai city (off the coast). The earthquake triggered a destructive tsunami with run up height of up to 40 meters that mainly affect cities located on the Pacific Ocean coast of the Tohoku region (north-east region of Japan). Reinforced concrete buildings in general resist the tsunami without collapse however the non-structural elements like panels and ceilings were severely damaged. The analysis of damages has permitted to understand the behavior of RC buildings under tsunami attack, and has also permitted to establish recommendations for their use to take refuge from tsunami in places where natural topography makes impossible to reach hilltops or other safer places.

A Study of Performance of Wastewater Treatment Systems for Small Sites

The pollutant removal efficiency of the Intermittently Decanted Extended Aeration (IDEA) wastewater treatment system at Curtin University Sarawak Campus, and conventional activated sludge wastewater treatment system at a local resort, Resort A, is monitored. The influent and effluent characteristics are tested during wet and dry weather conditions, and peak and off peak periods. For the wastewater treatment systems at Curtin Sarawak and Resort A, during dry weather and peak season, it was found that the BOD5 concentration in the influent is 121.7mg/L and 80.0mg/L respectively, and in the effluent, 18.7mg/L and and 18.0mg/L respectively. Analysis of the performance of the IDEA treatment system showed that the operational costs can be minimized by 3%, by decreasing the number of operating cycles. As for the treatment system in Resort A, by utilizing a smaller capacity air blower, a saving of 12% could be made in the operational costs.

Requirements Driven Multiple View Paradigm for Developing Security Architecture

This paper describes a paradigmatic approach to develop architecture of secure systems by describing the requirements from four different points of view: that of the owner, the administrator, the user, and the network. Deriving requirements and developing architecture implies the joint elicitation and describing the problem and the structure of the solution. The view points proposed in this paper are those we consider as requirements towards their contributions as major parties in the design, implementation, usage and maintenance of secure systems. The dramatic growth of the technology of Internet and the applications deployed in World Wide Web have lead to the situation where the security has become a very important concern in the development of secure systems. Many security approaches are currently being used in organizations. In spite of the widespread use of many different security solutions, the security remains a problem. It is argued that the approach that is described in this paper for the development of secure architecture is practical by all means. The models representing these multiple points of view are termed the requirements model (views of owner and administrator) and the operations model (views of user and network). In this paper, this multiple view paradigm is explained by first describing the specific requirements and or characteristics of secure systems (particularly in the domain of networks) and the secure architecture / system development methodology.

Entropy based Expeditive Methodology for Rating Curves Assessment

The river flow forecasting represents a crucial point to employ for improving a management policy addressed to the right use of water resources as well as for conjugating prevention and defense actions against environmental degradation. The difficulties occurring during the field activities encourage the development and implementation of operative computation and measuring methods addressed to time reduction for data acquisition and processing maintaining a good level of accuracy. Therefore, the aim of the present work is to test a new entropy based expeditive methodology for the evaluation of the rating curves on three gauged sections with different geometric and morphological characteristics. The methodology requires the choice of only three verticals along the measure section and the sampling of only the maximum velocity. The results underline how in most conditions the rating curves drawn can replace those built with classic methodologies, simplifying thus the procedures of data monitoring and calculation.

A Weighted Least Square Algorithm for Low-Delay FIR Filters with Piecewise Variable Stopbands

Variable digital filters are useful for various signal processing and communication applications where the frequency characteristics, such as fractional delays and cutoff frequencies, can be varied. In this paper, we propose a design method of variable FIR digital filters with an approximate linear phase characteristic in the passband. The proposed variable FIR filters have some large attenuation in stopband and their large attenuation can be varied by spectrum parameters. In the proposed design method, a quasi-equiripple characteristic can be obtained by using an iterative weighted least square method. The usefulness of the proposed design method is verified through some examples.

Processing and Assessment of Quality Characteristics of Composite Baby Foods

The usefulness of weaning foods to meet the nutrient needs of children is well recognized, and most of them are precooked roller dried mixtures of cereal and/or legume flours which posses a high viscosity and bulk when reconstituted. The objective of this study was to formulate composite weaning foods using cereals, malted legumes and vegetable powders and analyze them for nutrients, functional properties and sensory attributes. Selected legumes (green gram and lentil) were germinated, dried and dehulled. Roasted wheat, rice, carrot powder and skim milk powder also were used. All the ingredients were mixed in different proportions to get four formulations, made into 30% slurry and dried in roller drier. The products were analyzed for proximate principles, mineral content, functional and sensory qualities. The results of analysis showed following range of constituents per 100g of formulations on dry weight basis, protein, 18.1-18.9 g ; fat, 0.78-1.36 g ; iron, 5.09-6.53 mg; calcium, 265-310 mg. The lowest water absorption capacity was in case of wheat green gram based and the highest was in rice lentil based sample. Overall sensory qualities of all foods were graded as “good" and “very good" with no significant differences. The results confirm that formulated weaning foods were nutritionally superior, functionally appropriate and organoleptically acceptable.

Comprehensive Characteristics of the Municipal Solid Waste Generated in the Faculty of Engineering, UKM

The main aims in this research are to study the solid waste generation in the Faculty of Engineering and Built Environment in the UKM and at the same time to determine composition and some of the waste characteristics likewise: moisture content, density, pH and C/N ratio. For this purpose multiple campaigns were conducted to collect the wastes produced in all hostels, faculties, offices and so on, during 24th of February till 2nd of March 2009, measure and investigate them with regard to both physical and chemical characteristics leading to highlight the necessary management policies. Research locations are Faculty of Engineering and the Canteen nearby that. From the result gained, the most suitable solid waste management solution will be proposed to UKM. The average solid waste generation rate in UKM is 203.38 kg/day. The composition of solid waste generated are glass, plastic, metal, aluminum, organic and inorganic waste and others waste. From the laboratory result, the average moisture content, density, pH and C/N ratio values from the solid waste generated are 49.74%, 165.1 kg/m3, 5.3, and 7:1 respectively. Since, the food waste (organic waste) were the most dominant component, around 62% from the total waste generated hence, the most suitable solid waste management solution is composting.

The Photo-Absorption and Surface Feature of Nano-Structured TIO2 Coatings

Titanium dioxide coatings were deposited by utilizing atmospheric plasma spraying (APS) system. The agglomerated nanopowder and different spraying parameters were used to determine their influences on the microstructure surface feature and photoabsorption of the coatings. The microstructure of as-sprayed TiO2 coatings were characterized by scanning electron microscope (SEM). Surface characteristics were investigated by Fourier Transform Infrared (FT-IR). The photo absorption was determined by UV-VIS spectrophotometer. It is found that the spray parameters have an influence on the microstructure, surface feature and photo-absorption of the TiO2 coatings.