Print ISSN: 1813-0526

Online ISSN: 2220-1270

Volume 24, Issue 2

Volume 24, Issue 2, Summer and Autumn 2019, Page 1-150


Effect of magnetic field on mixed convection in superposed Nanofluid and porous layers inside lid-driven cavity

Ehab Abudlaziez Hamza; Abbas Saeed Hussain

AL-Rafdain Engineering Journal (AREJ), 2019, Volume 24, Issue 2, Pages 1-11
DOI: 10.33899/rengj.2019.164323

In the present research the effect of magnetic field on the mixed convection was carried numerically in lid driven composite two dimensional square cavity ,this cavity composed of two layers : a Cu-water nanofluid layer superposed a porous media ,the porous media saturated with the same nanofuid  The left and right walls are thermally insulated ,However the bottom wall which is in contact with porous media is isothermally hot while the top wall which is in contact with nanofluid layer is isothermally cold and being lid driven in constant velocity to right.
        The governing equations in this study were normalized and solved numerically by finite difference method. The convection term of the momentum and energy equations were treated by upwind scheme, while the diffusion and source terms were treated by central difference. Gauss-siedel iteration method were used for solution vorticity and energy equations and Successive Over Relaxation method were used for solution of stream function equation.. In this study the following parameters were considered:
Hartman number (Ha) from (0 to 60), nanoparticles volume fraction (0.01, 0.03, 0.05), Richardson number (Ri) (0.1, 1, 5), Darcy number (Da) (10-3, 10-4, 10-5) and porous layer thickness (Wp) (0.3, 0.5, 0.7) at constant Reynolds number (Re=100) and Prandtl number (Pr=6.24). The results show that increasing Hartman number causes a reduction in mixed convection heat transfer and this effect reduced by increased the porous layer thickness. In increased of Hartman number from 0 to 60 with Wp (0.3, 0.5, 0.7) a reduction in convection heat transfer. Moreover an increase in Richardson number ( Ri ) enhanced the convection heat transfer for all Hartman number , Also the increase of nanoparticles  volume fraction improve the heat transfer and this effect reduced as Hartman number increased. It is noticed that increasing Hartman number to 30 gives highest value of Nusselt number at lower thickness of porous layer.

Evaluating the Performance of the A2O System for Removing Nutrients from Municipality Wastewater

Saja Abd al-Razzaq Mohammed; Ammar Thamir Hamad

AL-Rafdain Engineering Journal (AREJ), 2019, Volume 24, Issue 2, Pages 12-24
DOI: 10.33899/rengj.2019.164334

Nitrogen and phosphorus are essential for the growth of micro-organisms used in wastewater treatment. When a treatment system is designed to remove a quantity of nutrients، larger than the ordinary metabolism requirements of bio-cell، the operation is called biological nutrient removal BNR. The BNR system consists of two processes: the biological nitrogen removal and the enhanced biological phosphorus removal (EBPR). There are several arrangements for biological nutrient removal processing. The selection of the suitable treatment scheme depends on the characteristics of the raw wastewater، quality of treated effluent required and the economical consideration. Several studies showed that the A2O system is the most suitable among different configurations because of its simplicity in operation، low oxygen requirements (i.e. low operational cost)، high efficiency of nutrient removal and a good settling characteristics of the sludge produced. A continuously flow laboratory scale of A2O was used in the current study. A raw municipal wastewater from the environmental engineering department is flowing at a rate of 0.6ml/sec. The mean cell residence time was 12 days. The experiments were conducted under three different internal cycle ratios (IR) and three returned activated sludge ratios، The effective sizes of the anaerobic، anoxic and aerobic compartments were 6.4، 8.65 and 17.21 L respectively، The results showed that the percentages of internal cycle ratio have a significant effect on the process of biological removal of nitrates while the percentage of returned activated sludge (RAS) has a significant impact on the biological removal of phosphorus. The A2O system removal efficiency of COD، orthophosphate and ammonia were: 85.7%، 93.5%، and 92.4%، respectively. The effluent quality is within the Iraqi standards with respect to organic and nutrients contents.

UNIFORMITY FOR PORTABLE GRID SPRINKLER SYSTEMS

Ahmad Thamer Ibrahim; Haqqi Ismail Yasin

AL-Rafdain Engineering Journal (AREJ), 2019, Volume 24, Issue 2, Pages 25-38
DOI: 10.33899/rengj.2019.164333

The proper size and diameter of the lateral sprinkler pipe is associated with the variations of pressure head along the pipeline; the greatest pressure head variations, the smallest pipe size and thereby an increase in the required pressure head at the inlet of lateral pipe and the pumping power unit.  The pattern of water distribution of sprinklers operating with different operating pressure will accordingly varies and may leads to variations in uniformity of water application along the lateral pipe. The research purpose is to study the effect of pressure head variation on the uniformity of the water distribution along the lateral pipe by adopting different values of the friction head losses that expressed as a fraction of average operating head, and linking with spacing between sprinkler heads. Furthermore, this study aims to compare between the increase in pumping power cost to ensure operating head at the lateral inlet associated with increase in the fraction of friction head losses, and decrease in the cost of the pipe. 18 tests were carried out to obtain the water distribution pattern for single sprinkler under different pressure heads and for five different type sprinklers,the water distribution pattern of a single sprinkler was estimated as a function of distance from the sprinkler and the pressure head with non-physical formulas and high determination coefficients. Fractions of head losses due to friction were chosen to be (10, 20, 30, 40, and 50) % of the sprinkler operating head. A computer program was developed to compute the pressure head at each sprinkle, water distribution pattern, and water application uniformity of the sprinkler network system using different sprinkler head spacing and three levels of operating heads. Also, the economics of pipe size and pumping operation cost using the selected fractions of the friction head losses was studied.
The results show that the water distribution uniformity increases when the pressure head at sprinkler head increases and this increase varies according to the sprinkler type and spacing; there is no observable change between the system water distribution uniformity and uniformity coefficient of application at the average operating pressure head for all sprinkler spacings and friction head looses fractions except the case of friction head loose equal to 50% of the operating head that showed very small differences. Also, the annual pumping cost to ensure required pressure head at lateral pipe inlet using same average operation head is constant for all used sprinkles. The total annual cost increases when the adopted friction head loose in the design of lateral sprinkler pipe increases stating that the economic pipe size is associated with low friction.

Using Intelligent Techniquesin Sustainable Buildings

Sinan Mohammad Talee

AL-Rafdain Engineering Journal (AREJ), 2019, Volume 24, Issue 2, Pages 39-55
DOI: 10.33899/rengj.2019.164354

Intelligent techniques represent integration between building system and technology. The merge of these techniques within a building serves and eases our life. Intelligent techniques became a common concept that defines the highest levels of various standards, which determine indoor environmental health. In other words, they increase productivity, raise prosperity, as well as enhancing the efficiency of resources, cost, flexibility, and adaptability. Thus, intelligent techniques reflect the concept of sustainability, as their effects cover all the main building aspects of function, structure, and form. The study considers form as the most obvious affected aspect of a sustainable building, especially as the intelligent techniques and materials formed the building envelope.
 
 The research is conducted on case-study samples from the region of Arab Gulf, which have a hot desert climate that is similar to the third desert climate in Iraq. The study defines the research problem as The knowledge insufficiency of the formal aspect identifications (with various classifications) that affected by intelligent techniques of sustainable buildings in the hot desert climate. The research aims to determine the aspects affected by intelligent techniques of the sustainable building in general and to verify their role and impact on the formal aspect of the façade design that can achieve the sustainability standards. Further, the samples of the case-study location in the hot desert climate aim to employ results on our local architecture in Iraq particularly.
 
The study defines its own structure and methodology in order to achieve its goals and solve the research problem, by dividing the research into several stages. Starting from defining the concept of the intelligence, and exploring previous studies to represent the theoretical framework. Then, listing the case-study samples, and measuring them using the descriptive analysis method, by analyzing the critical contexts upon the selected samples. The research concluded important points of the impact of the intelligent techniques on the formal aspect of the building. As the harsh conditions of the hot desert climate represent itself as a main challenge in the process, building protection against solar radiation and incandescent is vital. That is possible by methods of stirring, resistance, modulation, the control of the intelligence and the sustainability of the exterior materials.

Numerical Analysis of Effect of Nano-particles on Fluid Flow and Heat Transfer by Forced Convection in Channel with different traingle configuration

Ammar A. Mahmood; Amir S. Dawood

AL-Rafdain Engineering Journal (AREJ), 2019, Volume 24, Issue 2, Pages 56-64
DOI: 10.33899/rengj.2019.164321

This research presents a numerical analysis of the three-dimensional simulation of heat transfer and fluid flow incloded forced convection through a square-section channel with different ribs and the effect of addition of nanoparticles with constant heat flux up and down the channel. The single-phase approach of Nano-fluid is employed; it is assumed that the base fluid (water) and nanoparticles (Al2O3) are treated as a homogeneous mixture. The study assumes that the Nano-fluid incompressible, steady and laminar. The nanoparticles used in 25 nanometers and with volumetric concentration (1-5) %. ANSYS 18.1 FLUENT is a computational fluid dynamics (CFD) program. The finite volume method was used to solve the ruling equations. To ensure accuracy of the results, the validity was performed with previous studies of the channel and under the same boundary conditions and the result was Compatible. By using ribs at the top and bottom of the channel in two alignment inline and staggered, and five ribs per surface, and in tow shapes (triangle A and triangle B). The aspect ratio is equal to (2(. with five different values for Reynolds numbers (300, 500, 700, 900 and 1200). The results showed that triangular ribs type (A) with staggered alignment represent the optimal state of the all studied shapes and at all Reynolds numbers. The maximum value of the performance evaluation criteria (PEC) was 1.8561 and the use of Nano-fluid at a concentration of 5% compared to 1.5991 for the same channel using water only, and at Reynolds number 1200. At 5% volume concentration, the heat transfer coefficient (h) was 29.78% higher than the thermal conductivity increase of 16.48% when using only the Nano-fluid. When adding the triangular ribs type (A), the increase in heat transfer coefficient (h) is equal to (143.03%). Actually, other factors such as dispersion, Brownian motion, hermophoresis, vortex generator, and nanoparticles migration also are responsible for the enhancement of convective heat transfer.

Performance Study of Concentrated Circular Channels System (Orbal) for Removing Nutrients from Domestic Wastewater

Ammar Th. Hamad Al-Tai; Moamen W. Fathel Al-Tak

AL-Rafdain Engineering Journal (AREJ), 2019, Volume 24, Issue 2, Pages 65-73
DOI: 10.33899/rengj.2019.164328

   A biological nutrient removal was investigated as a continuous flow (orbal) system to study the efficiency of system for removing phosphor and nitrogen compounds, and to predict the effect of internal and external recirculation rates on its performance. The pilot plant consisted of three concentric circular channels: outer, intermediate and inner in capacities of 24, 16.8 and 8.7 m3 respectively. The last sedimentation basin has sludge return system to the outer channel. Pilot plant also has an internal cycle to return the mixed liquor from the inner channel to the intermediate one. Continues Flow was used to feed the plant with raw municipal wastewater from Al-Khadraa residential quarter at an average flow rate of 66.7 m3/day. The plant was equipped with a modified surface aeration system operating in total power equal to 0.48 kW to achieve the required dissolved oxygen concentrations in the outer, middle, and inner channels:  0.38, 1.3, and 2.4 mg /L respectively. The three-channel was operated on two levels of returned activated sludge (RAS): 60% and 80%. It has three levels of internal cycle (IR): 100%, 150% and 200%. The results showed: the total removal efficiencies of phosphorous, and ammonia were in the range of: (93.3% - 88.5%) and (93.5% - 92.4%), respectively. The results meet the Iraqi standards for wastewater disposal into rivers. This study revealed there is no significant correlation between removal efficiency of ammonia with the internal and external recirculation ratios, while the effluent phosphor concentrations significantly affected by RAS and IR ratios. This study adopted the hypothesis: the process of simultaneous nitrification and denitrification (SND) occurs in the outer channel, while the phosphorus removal by the pilot plant was performed by the mechanism of enhanced biological phosphorous removal (EBPR).

Simulation of Cold Forming of Spur Gears using DEFORM 3D

Zainab Mohammed T. Rasheed; Mohammed Najeeb Abdullah

AL-Rafdain Engineering Journal (AREJ), 2019, Volume 24, Issue 2, Pages 74-80
DOI: 10.33899/rengj.2019.164324

In the current study, the DEFORM3D program was used to simulation of cold forming of spur gears using lead metal. Three different forms of billets were used to forming the spur gear and the choose of the size of billets was determined according to the size of suggested gear in this study. Analyzes were performed such as effect of stress, strain, average stress, total distance and speed during the formation process. Through the results of the values ​​of the average stresses for the three billets, it was observed that the lowest value is obtained when using a solid billet. As indicated by the results of the study of the maximum stress occurs when the use of hollow billet with a diameter of 4 mm. In the study of effective stress, it was observed that there was a convergence in the stress values ​​for all work pieces; these values ​​in the age zone are greater than the center area. The results obtained from numerical modeling showed that the minimum effective strain occurs when using a hollow billet with a diameter of 4 mm and the highest value when using a solid billet. The velocity of the metal flow is proportional with the shape of the billet, it is noted that the value of the velocity in the case of hollow billets (4 mm and 6 mm) was close together and higher than the value of the metal flow velocity when using a solid billet. The speed of the metal flow is proportional with the amount of the billet cavity; in the case of the hard solid billet the speed is low. Peak load is affected during the formation of the spur gear with the shape of billet; it was observed that the peak load values ​​of the 4 mm hollow billet were less than the peak load of the other two cases.

Architectural Image of Mosques in terms of Historical Drawings Mental Image of Mosques in Miniature of Maqamat Al-Hariri

Sura Mohammed Adil Khaleel; Hassan Mahmood Kasim

AL-Rafdain Engineering Journal (AREJ), 2019, Volume 24, Issue 2, Pages 81-100
DOI: 10.33899/rengj.2019.164322

Islamic architecture (and Mosques) still the focus of attention for researchers and architects, there are continues attempts to renew the way that we look at the heritage of this architecture; to find what enrich and present new knowledge about the emergence of forms that was unique. The perception process is the most important part of architectural design process, It is the result of the designer's effort to determine the final outcome of the architectural work. This is because of the importance of the mental images that are formed in the recipient's perception of architecture he sees and lives in.
         As for Mosque architecture, scarceness of evidences and researches about the perception of people (whether they were producers or recipients) who lived in buildings of Islamic architecture at old ages when it was built.... In order to inquest recipients of Islamic Architecture at time when it was built; the aim of this research is to analyze the historical drawings (specifically the Arab miniatures), as an aspect to reveal the mentality of the recipient of that age which considering the painter who produced it as a witness to his age by his drawings which documented his mentality (the mentality of the prevailing culture). Research  procedure was to explore Moaque Architecture Factors from literature of Islamic Architecture, then to explore these factores by analyzing 12 miniatures selected from the two miniatures manuscripts of "Maqamat Al Hariri".
       By the discussion of results, it became clear that the mental image of the general architectural characteristics of the mosque extracted from the miniatures is represented by focusing on the inner spaces more than the external spaces, especially facades of courtyard, mosque extended horizontally dominated by strictly symmetry, and with high diversity in the use of architectural and decorative elements, and thus be compatible with the image of the mosque in modern literature. As for the mental image of mosque in terms of the architectural elements, it is mainly depicted as spaces with arches carried by columns with lamps hanging from them with much of decorative and secondary elements, with the presence of the mihrab, and minbar with moderate rate, minarets appeared in a few rates, while domes, doors and windows in rare rates. Thus this mental image of the mosque at that time realizes the architectural elements in rates that differ from what modern literature provides, specially about the importance of minarets and domes.

Effect of Impact Velocity and Angle on Erosion Behavior for Polymeric Composite Materials

Ahmed W. Khalid; Abdullhaqq A. Hamid

AL-Rafdain Engineering Journal (AREJ), 2019, Volume 24, Issue 2, Pages 101-114
DOI: 10.33899/rengj.2019.164326

Due to significant effect of the phenomenon of erosion and its entry in many engineering and industrial applications, hence the importance of the study of erosion, especially the key factors of impingement velocity and impingement angle, because of their high effect on the phenomenon of erosion. The erosion testing device was manufactured according to ASTM G76 specifications, and devices rotating molds casting and vacuum equipment were manufactured, and unsaturated polyester specimens and its composites were reinforced with two types of reinforcing materials silicon carbide particles (SiC) and fiberglass (5 wt. %) and (44%. wt. %) respectively.  The impingement velocity (25.2, 33 m / s) and impingement angles (30°, 60° and 90°) affecting erosion were studied. From the results obtained, it is noted that the behavior of polyester was brittle behavior and the composites behaves semi-ductile. And that the maximum erosion rate of polyester is at an impingement angle (90°) and the maximum erosion rate of polyester composites is at an impingement angle (60°). Silicon carbide particles improved erosion resistance at the impingement angles (90°, 30°), but at an angle (60°) they reduced pure polyester resistance to erosion, while fibers increased the rate of erosion. It was noted that the relationship between the impingement velocity and the rate of erosion is a direct relationship and that the effect of increasing the impingement velocity on the angle of impingement (60°) is greater than its impingement on the angles (90°, 30°).

Manufacturing of Erosion Measuring Rig for Polymers and Their Composites with some Experimental Results

Ahmed W. Khalid; Abdullhaqq A. Hamid

AL-Rafdain Engineering Journal (AREJ), 2019, Volume 24, Issue 2, Pages 115-129
DOI: 10.33899/rengj.2019.164327

Solid Particle Erosion System was manufactured as a laboratory and according to the ASTM G76 specifications in a horizontal position with a feeder screw, as the system consists of the main parts: air compressor, voltage regulator, and rubber connection hoses. And the main parts of the rig: nozzle, screw, DC motor, transmission pipes, and Installation platform. The nozzle was made of low alloy steel and hardened by water-quenching, and the conical nozzle cavity was made to insert sand into the nozzle barrel. Tolerance was chosen between the screw and cylinder in practice, with a tolerance of (4 mm) out of two experiments that were tried (2, 4 mm). So, the tolerance was chosen based on the used particles (erodent) in different ranges (150-350 µm), (350-500) µm) and (500-710 µm), preferably a tolerance that gives a smooth spin rotation. One of the things to consider is the stability of the sand flow rate and the issue of overflow or vice versa is the occurrence of a stop flow, and taking into consideration the calibration between the spin rotation and the pressure of the air. Also, the sizes of sand particles used can determine several things, including tolerance, the diameter of the nozzle barrel, and the velocity of particles that can be taken. The rig was tested for specimens of unsaturated polyester (UP) and its composites reinforced with (5 wt. %) of silicon carbide, where the experiment was carried out at an impingement velocity (25.2 m / s) and impingement angles (30°, 60°, 90°) and the size of the erodent from sand Silica has a size of (350-500 µm), so the results showed that the polyester gave the highest erosion rate at the angle (90°), which indicates its brittle behavior, while its composites gave the highest erosion rate at the angle (60°), which indicates its semi-ductile behavior. It is comparing the results obtained with previous research that shows that the rig gave positive results, and it can measure the rate of erosion of polymeric materials and their composites.
 

Effect of Irrigation Scheduling Using CROPWAT on Water Use Efficiency and Grain Yield and Components for Maize (Zea mays L.) in Semi Arid Regions

Ahmed Azhor Thanoon

AL-Rafdain Engineering Journal (AREJ), 2019, Volume 24, Issue 2, Pages 130-137
DOI: 10.33899/rengj.2019.164329

Irrigation scheduling is determining the appropriate time and quantity of irrigation to reach maximum production. In this research the irrigation scheduling was determined using a computer program CROPWAT , developed by FAO . The program used the climate , crop , and soil data for calculation the irrigation scheduling .The climate data represents average years (1971-2007) of pan evaporation to Mosul city for calculating the reference evapotranspiration , maize crop and light soil data , were used to input data . The program was used cases include three different irrigation timing levels are 100%, 70% and 50% of the readily soil moisture depletion(critical depletion and belowcritical depletion) with refill soil moisture content to field capacity . The results of  irrigation scheduling from the program were applied to the field experiment in the Mosul Technical Institute during the summer of 2010. The grain yield and components were measured at harvest to improve the best irrigation scheduling for maize crop in semi arid regions .
The results showed that the depth of irrigation added to three different irrigation levels 100% and 70% and 50% of the readily soil moisture depletion reached 860 and 881 and 900 mmrespectively, the number of irrigations 15, 21, 29 . The results also showed that the best irrigation scheduling for higher water use efficiency was0.55 kg/m3 and highest production356g/m2 for the treatment of 70% of  the readily soil moisture depletion. Therefore the CROPWAT is aneffective tool for planning and management of irrigation maize in semi arid regions .

The Situation Of Water Treatment Plant In Mosul City

Musab Abduljabbar al-tamir

AL-Rafdain Engineering Journal (AREJ), 2019, Volume 24, Issue 2, Pages 138-145
DOI: 10.33899/rengj.2019.164330

Abstract
The present paper dealt with the evalution of quantiy and qualtiy of water treatmetn plants WTPs withen Mosul city. According to the total productivity of WTPs the per capita share of water was 785 L/d, and after subtracting the losses and violation upon the water supply network that reaches upto 50% the per capita portion of water becomes 392 L/d. For the quality of water; the study revealed that there are a segnificant effect of the WTPs processes upon the water quality parameters of the product water comparing with the raw water, and the quality of product water is withen the Iraqi dirnking water spicifications regarding to the parameters taken into account withen the study. This study concentric to the turbidity removal by WTPs because these plants are designed to reduce the turbidity of water to acceptable levels withen the Iraqi specification. turbidity of water is out of the specification in 13% of the samplise with different portions through the WTPs, but the highst was at aldanadan and alsaheroon plants.
Duncn test revealed that there are a significant different betweent the average of the residual turbidity and  between the average of percentage removal of turbidity between WTPs and the worest plant from the residual turbidity are alsaheroon, alghzlani and aldanadan. And the woreste plant from the percent turbidity removal are alaiser aljadeed and alaiser altawsie.

Automated Segmentation of Retinal Blood Vessels using Fast Marching Method and local mathematical analysis

Hebat_allah Abd-Alaziz Alkhaddour

AL-Rafdain Engineering Journal (AREJ), 2019, Volume 24, Issue 2, Pages 1-9
DOI: 10.33899/rengj.2019.164325

In this work, Fast Marching Method (FMM) has been suggested for Retinal blood vessels segmentation. FMM is an optimization technique; and the main advantage of the FMM is its ability to deal with branches and bifurcations without any additional computational cost. This advantage had been used in robotics to find the optimal path for the robot to move from the starting point to the goal with no collisions. Considereing the tree structure of blood vessel, I will use FMM to find the shortest bath between the optic disk and the blood vessels ends to draw the tree of the blood vessels.This method has been implemented using the M language in MATLAB R2016b.  In this work local mathematical analysis has been implemented so that we can have an initial estimation of blood vessels distribution in an image in order to minimize the huge amount of noise included in retinal images and to make FMM implementing easier. FMM performance had been compared to other techniques used for retinal blood vessel detection like “Matched Filters”. The results showed that the FMM performance overcame some of those techniques and close to other high resolution methods. The FMM algorithm has been validated using the well-known “DRIVE” database and the resulting resolution ranged between 80% to 93% (depending on the noise amount in image) with iteration number between 500 to 1000 (according to the optic disk position in the image) with an average time of 0.57 seconds for each iteration which mean that the total running time is 5-10 minutes. FMM had also been validated using STARE data set and achieved a TPR of 90% for 700x605 STARE images in 15 minutes, and a TPR of 86% in 2.6 minutes when reducing image size to 350x303.

Investigation of Local Scour Around Group Bridge Pier with Different Shapes

Tahseen A. GELMIRAN; Khalil I. Othman; Mustafa GUNAL

AL-Rafdain Engineering Journal (AREJ), 2019, Volume 24, Issue 2, Pages 10-22
DOI: 10.33899/rengj.2019.164355

In this study, the establish on laboratory experiments for computing the depth of local scour (ds) around group bridge pier. For this purpose, fifteen models of bridge piers were constructed and tested, divided into five groups, of each group containing three bridge piers with the same specifications. The diameter of upstream bridge piers (D1) was varied to 2, 4, 6, 8, and 10 cm, and diameter of downstream bridge piers (D2) 10 cm for all. The spacing (S) between the bridge piers was varied three times 20, 30, and 50 cm for all groups. Considering the effectiveness study of upstream flow conditions, the size of diameters of bridge piers, the spacing between bridge piers and medium size of bed material on the maximum scour depth and scour pattern around bridge piers. The study was conductedby employing a physical hydraulic model for bridge piers operated below subcritical flow, clear-water condition and exploitation uniform cohesionless sand as bed material. The experimental results showed the scour depth (ds) increasing whenever increasing the upstream diameter (D1) of bridge pier and decreasing whenever decreasing the spacing (S) between bridge piers. The dimensional analysis techniques and statistical program were used for locating a new empirical formula with the facilitate of the experimental information; this formula is for calculating the maximum scour depth at bridge piers.

Real-Time Voice Transmission over Wireless Sensor Network (VoWSN) based Automatic Speech Recognition (ASR) Technique

Ina`am Fathi; Qutaiba Ibrahim Ali; Jassim M. Abdul-Jabbar

AL-Rafdain Engineering Journal (AREJ), 2019, Volume 24, Issue 2, Pages 23-35
DOI: 10.33899/rengj.2020.126441.1005

In this paper an efficient Real-Time Voice over Wireless sensor network (VoWSN) platform based on Automatic Speech Recognition (ASR) system to be used in emergency scenarios is proposed, implemented and evaluated. The workflow principle of the proposed system is depending on a Category Transformation Protocol (CTP) that transforms system category gradually from network dependent ASR system with a full dictionary and language model (i.e. large vocabulary) to fully embedded ASR system with customized dictionary and language model (i.e. small vocabulary ). Moreover, a comparison study has been performed between our proposed VoWSN based ASR system and a VoWSN based streaming system. This comparison is performed to elaborate the gains achieved when sending the text of the voice signal instead of sending the voice signal. Additionally, the Voice over IoTs (VoIoTs) system has been evaluated utilizing Voice streaming or ASR system to evaluate the system performance when connecting to the Internet.