A numerical finite-volume calculation method was used for application to fully-developed flow and heat transfer in straight ducts with 2-Cusp, 3-Cusp and 4-Cusp cross-sectional area. The method was formulated with reference to a non-orthogonal curvilinear coordinate system which was fitted exactly into duct shape. In turbulent flow, the Reynolds stresses were calculated by using the coupled algebraic stress model of Launder and Ying (1973) with a (k ) transport model. This turbulent stress model enabled secondary flows to be included in the non-circular duct calculations. In heat transfer solution, three thermal boundary conditions were investigated. Predictions were compared with available numerical and experimental data. The turbulent

The dynamics of flow and turbulence surrounding groynes in a bending canal are highly complex behaviors. This study, which was conducted by HEC-RAS version 6.5 software, focuses on the use of curved groynes in 180°-degree bend canals to study the flow behavior in bending by calculating the velocity of flow along the concave outer edge, in which bank erosion usually occurs, the flow velocity at the inner edge, and calculating the vortices that form between the groynes. The results showed that the curved groynes outperformed the commonly used straight groynes in the same conditions. The findings indicate that curved groins decrease the flow velocity at the outer edge by 99%, while straight groins achieve a reduction in fl

When selecting a material for product design, the focus is on its mechanical properties, a standard requirement in most applications. This paper’s research aimed to determine if better calibration of polymethyl methacrylate (PMMA) material samples welded with laser spot welding could be achieved by verifying joint strength performance and modulus of elasticity. Tensile tests were conducted using a universal testing machine with a 100 kN load capacity. Parameters studied included laser power, welding velocity, laser focus diameter, and spot geometric size. An orthogonal L9 array with three levels was used. Multi-objective optimization techniques TOPSIS-Quality Loss Function were used, and the results were compared. It w

This paper explores a fuzzy-logic based speed controller of an interior permanent magnet synchronous motor (IPMSM) drive based on vector control. PI controllers were mostly used in a speed control loop based field oriented control of an IPMSM. The fundamentals of fuzzy logic algorithms as related to drive control applications are illustrated. A complete comparison between two tuning algorithms of the classical PI controller and the fuzzy PI controller is explained. A simplified fuzzy logic controller (FLC) for the IPMSM drive has been found to maintain high performance standards with a much simpler and less computation implementation. The Matlab simulink results have been given for different mechanical operating conditions. The simulated

Low-level microbial activity due to the production of organic acids is a recognized problem during the initial phase of food waste composting. Increasing such activity levels by adjusting the pH values during the initial composting phase is the primary objective to be investigated. In this study, sodium acetate (NaoAc) was introduced as an amendment to an in-vessel composting system. NaoAc was added when the pH of the compost mixture reached a low level (pH < 5), the addition increased pH to 5.8. This had a positive effect on the degradation of organic materials i.e. the formation of methane gas compared to the results without NaoAc addition.

The results also proved that anaerobic-aerobic in-vessel composting could reduce the

The adsorption of Cr (VI) from aqueous solution by spent tea leaves (STL) was studied at different initial Cr (VI) concentrations, adsorbent dose, pH and contact time under batch isotherm experiments The adsorption experiments were carried out at 30°C and the effects of the four parameters on chromium uptake to establish a mathematical model description percentage removal of Cr (VI). The
analysis results showed that the experimental data were adequately fitted to second order polynomial model with correlation coefficients for this model was (R2 = 0.9891). The optimum operating parameters of initial Cr (VI) concentrations, adsorbent dose, pH and contact time were 50 mg/l, 0.7625 g, 3 and 100 min, respectively. At these conditions, th

The sealing effects of squeeze air film were analyzed experimentally and theoretically The air flow rate and the sealed pressure were measured in a squeeze face seal. The air flow rate can be expressed as the difference between the flow rate by the pumping and the flow rate by the leakage. The air flow rate by the pumping increases proportionally to the square of the vibration amplitude of the surface, as does the sealed pressure. The air flow rate by the leakage increases proportionally to the pressure difference between the vessel pressure and the ambient pressure. The experimental results showed good agreement with the theoretical results.

Orthogonal Frequency Division Multiplexing (OFDM) is an efficient multi-carrier technique.The core operation in the OFDM systems is the FFT/IFFT unit that requires a large amount of hardware resources and processing delay. The developments in implementation techniques likes Field Programmable Gate Array (FPGA) technologies have made OFDM a feasible option. The goal of this paper is to design and implement an OFDM transmitter based on Altera FPGA using Quartus software. The proposed transmitter is carried out to simplify the Fourier transform calculation by using decoder instead of multipliers. After programming ALTERA DE2 FPGA kit with implemented project, several practical tests have been done starting from monitoring all the results of

Many of mechanical systems are exposed to undesired vibrations, so designing an active vibration control (AVC) system is important in engineering decisions to reduce this vibration. Smart structure technology is used for vibration reduction. Therefore, the cantilever beam is embedded by a piezoelectric (PZT) as an actuator. The optimal LQR controller is designed that reduce the vibration of the smart beam by using a PZT element.  

In this study the main part is to change the length of the aluminum cantilever beam, so keep the control gains, the excitation, the actuation voltage, and mechanical properties of the aluminum beam for each length of the smart cantilever beam and observe the behavior and effec

In this research, a procedure to solve problems of unsteady flow to wells in confined aquifers by the computer is developed. The solution is based on the [THEIS:1935] procedure to solve such problems. The developed procedure is applied to (14) different sets of well – test data, including a predicted ideal one. The respective problems are solved completely by the computer without the need to construct or to refer to tables or nomographs; this, accordingly, deletes the role of personal judgment and the need to a high skill.
The applications indicate that the developed solution procedure is simple, easy to use, elaborate, superiorly fast in giving the required results, and comparatively accurate. Despite that the developed solution pr

Rutting is a significant problem in flexible asphalt pavements, causing permanent deformation. Increased traffic, axle load, tire pressure, and hot weather have recently accelerated rutting in flexible pavements. Several researchers have suggested using nanomaterials to improve asphalt pavement and prolong its lifespan. The nano clay chosen for this study is a natural, hydrophilic montmorillonite in its raw form. Consequently, incorporating Nano-montmorillonite (MMT) into asphalt mixtures to improve performance under dynamic loads has gained significant attention. This can help reduce rutting damage and ensure the safety and durability of road surfaces. This study examines the impact of incorporating MMT into hot mix asp

In this study, a genetic algorithm (GA) is used to detect damage in curved beam model, stiffness as well as mass matrices of the curved beam elements is formulated using Hamilton's principle. Each node of the curved beam element possesses seven degrees of freedom including the warping degree of freedom. The curved beam element had been derived based on the Kang and Yoo’s thin-walled curved beam theory. The identification of damage is formulated as an optimization problem, binary and continuous genetic algorithms
(BGA, CGA) are used to detect and locate the damage using two objective functions (change in natural frequencies, Modal Assurance Criterion MAC). The results show the objective function based on change in natural frequency i

In this paper, an exact stiffness matrix and fixed-end load vector for nonprismatic beams having parabolic varying depth are derived. The principle of strain energy is used in the derivation of the stiffness matrix.
The effect of both shear deformation and the coupling between axial force and the bending moment are considered in the derivation of stiffness matrix. The fixed-end load vector for elements under uniformly distributed or concentrated loads is also derived. The correctness of the derived matrices is verified by numerical examples. It is found that the coupling effect between axial force and bending moment is significant for elements having axial end restraint. It was found that the decrease in bending moment was
in the

In this study, the induced splined shaft teeth contact and bending stresses have been investigated numerically using finite element method(Ansys package version 11.0) with changing the most effecting design parameter,(pressure angle, teeth number, fillet radius and normal module), for internal and external splined shaft. Experimental work has been achieved using two dimensional photoelastic techniques to get the contact and bending stresses; the used material is Bakelite sheet type “PSM-4”.
The results of numerical stress analysis indicate that, the increasing of the pressure angle and fillet radius decrease the bending stress and increase the contact stress for both internal and external spline shaft teeth while the increasing of

 This study deals with thermal cyclic loading phenomena of plates which were fabricated from

composite materials (woven roving fiber glass + polyester) were exposed to (75 C°) temperature

gradient thermal shock for ten times in different stage of conditioning times due to the effect of thermal

fatigue using the method of Levy solution and compared these results with both results from

experimental published work and (ANSYS Ver. 9) program. A composite laminate plate with fiber

The artistic dimension appears as an important factor in urban townscape's identity shaping, as many cities in the world have a different identity through the different artistic elements in it, the artistic dimension is meant within the research (set of artistic elements that can contribute to urban identity shaping, whether on architecture or on urban design in addition to public, urban arts). Many previous global studies have dealt with one type or more of art affecting the urban townscape identity of specific cities as a case study. Thus, we can diagnose the research problem as (the lack of local knowledge about the role of the artistic dimension in all its components in achieving the urban townscape identity), and th

This research deals with the review of former research that made to solve the challenges and complexities of both static and dynamic soil structure interaction through discussing advanced computational models and their applications and exploring methods of solving the challenges of soil structure interaction in foundation engineering to provide a guide for the engineering community through the complexes of soil structure interaction. It was found that the numerical analysis for both static and dynamic soil structure interaction using the finite element method with the aid of advanced computional models is ideal for dealing with the non-linearity of soil and structure properties and loading conditions and that the use of

The seismic design of pile foundations mainly relies on analyzing the seismic response of layered, liquefiable locations. Two design scenarios are taken into consideration from the case histories; the first is how pile foundations react to the stresses and lateral displacements brought on by the lateral dispersion of liquefied soil. The second is how to piles reaction to seismic activity that occurs with the development of high pore water pressures. The PLAXIS 3D software is utilized in this research with a non-linear soil constitutive model (hypoplastic model) for both dry and saturated loose sandy soils under the impact of two earthquakes and the motion of different features to give a complete understanding of the dyna

Stripping is one of the major distresses within asphalt concrete pavements caused due to penetration of water within the interface of asphalt-aggregate matrix. In this work, one grade of asphalt cement (40-50) was mixed with variable percentages of three types of additives (fly ash, fumed silica, and phosphogypsum) to obtained an modified asphalt cement to resist the effect of stripping phenomena .The specimens have been tested for physical properties according to AASHTO. The surface free energy has been measured by using two methods namely, the wilhelmy technique and the Sessile drop method according to NCHRP-104
procedures. Samples of asphalt concrete using different asphalt cement and modified asphalt cement percentages(4.1,4.6 an

In this study, a dynamic analysis of machine foundations under vertical excitations is carried out.
The effect of embedment and foundation geometry has been taken into account. The stiffness and
damping of soil are considered as frequency dependents. A computer program (CPESP) in FORTRAN POWER STATION has been coded to evaluate the stiffness and damping coefficients depending on excitation frequency and embedment depth. Results have shown that increasing the embedment depth leads to increasing the resonant frequency and decreasing the amplitude of vibration.

Formation of emulsions during oil production is a costly problem, and decreased water content in emulsions leads to increases productivity and reduces the potential for pipeline corrosion and equipment used. The chemical demulsification process of crude oil emulsions is one of the methods used for reducing water content. The demulsifier presence causes the film layer between water droplets and the crude oil emulsion that to become unstable, leading to the accelerated of water coalescence. This research was performed to study the performance of a chemical demulsifier Chimec2439 (commercial) a blend of non-ionic oil-soluble surfactants. The crude oils used in these experiments were Basrah and Kirkuk Iraqi crude oil. These

This research presents a new study in reactive distillation by using consecutive reaction: the saponification reaction of diethyl adipate (DA) with sodium hydroxide solution .

The effect of three parameters were studied through a design of experiments applying 2³ factorial design . These parameters were : the mole ratio of DA to NaOH solution (0.1 and 1) , NaOH solution concentration (3 N and 8 N) , and batch time (1.5 hr. and 3.5 hr.) . The conversion of DA to sodium monoethyladipate(SMA)(intermediate product) was the effect of these parameters which was detected . Also , the percentage purity of the intermediate product was recorded . The results showed that increasing mole ratio of DA to NaOHsolutio

This research was conducted using ceramic microfiltration membrane for treatment of oily wastewater in the pilot-scale dead-end filtration system designed in the laboratory under the influence of conditions of feed flow rate 15-35 l/h, feed temperature 32-48°C, oil feed concentration 300-1200 ppm, feed solution pH 2.6-9.8. The influence of these conditions on the permeate flux rate and oil rejection percent were investigated. Experimental results indicated that when feed flow rate increased to 35 l/h permeate flux
rates increased to 100 l/m2.h and oil rejection percent decreased to 70.1%, and when feed temperature
increased to 48 ºC permeate flux rate increased to 62 l/m2.h and oil rejection percent decreased to 56.44%.
But wh

A new method for generation and simulation of meshing for involute helical gears is presented. The
approaches proposed for generation are based on the imaginary application of two rack-cutters one
for pinion and the other for gear generation. The proposed simulation of meshing of aligned and
misaligned helical gears gives (i) the shift of the bearing contact (real contact path) on pinion and
gear tooth surfaces, (ii) the function of transmission errors.

Global Navigation Satellite System (GNSS) is considered to be one of the most crucial tools for different applications, i.e. transportation, geographic information systems, mobile satellite communications, and others. Without a doubt, the GNSS has been widely employed for different scientific applications, such as land surveying, mapping, and precise monitoring for huge structures, etc. Thus, an intense competitive has appeared between companies which produce geodetic GNSS hardware devices to meet all the requirements of GNSS communities. This study aims to assess the performance of different GNSS receivers to provide reliable positions. In this study, three different receivers, which are produced by different manufactur

تظهر التربة القابلة للانهيار بالإضافة إلى الانواع الأساسية الأخرى التي تسبب مشاكل مثل التربة الانتفاخية والتربة العضوية، والمعروفة باسم التربة ذات المشاكل، قوة كبيرة عندما تجف ولكنها تتعرض لفقدان كبير في القوة عندما تكون مشبعة، مما يؤدي إلى هطول مفرط. إن توقع استجابة التربة للفيضانات والانهيارات الأرضية أو المستوطنات الكبيرة يمثل تحديًا هندسيا في هذه الأنواع من التربة. حيث يحدث الانخفاض الدائم في حجم ال

Random Number Generators (RNGs) are an important building block for algorithms and protocols in
cryptography. They are dominant in the construction of encryption keys and other cryptographic algorithm parameters. In practice, statistical testing is employed to gather evidence that a generator indeed produces numbers that appear to be random. In this paper a new algorithm is proposed to generate variable length random binary sequence. The random sequence is generated by selecting different point from hashed digital images; the selecting process is organized in such a way to ensure randomness and to avoid regeneration of same sequence within a year. The generated sequences are tested to meet the National Institute of Standard and Techno

A research was conducted to determine the feasibility of using adsorption process to remove boron from aqueous solutions using batch technique. Three adsorbent materials; magnesium, aluminum and iron oxide were investigated to find their abilities for boron removal. The effects of operational parameters on boron removal efficiency for each material were determined.
The experimental results revealed that maximum boron removal was achieved at pH 9.5 for magnesium oxide and 8 for aluminum and iron oxide. The percentage of boron adsorbed onto magnesium,aluminum and iron oxide reaches up to 90, 42.5 and 41.5% respectively under appropriate conditions. Boron concentration in effluent water after adsorption via magnesium oxide comply with th

An analysis was performed on the treated water from two water treatment plants in Baghdad
city. This analysis was used to evaluate the stability of the treated water from these plants and
that will flow in the distribution system to consider its corrosivity. The variation in water
stability with time and distance from the north to the south of Baghdad was indicated. The
analysis showed that the flowing water in the distribution system in Baghdad is corrosive to very
corrosive water by calculating Ryznar stability index (RI). In Al- Karkh WTP in the north, RI
maximum ranged between 7.958 to 9.403 where RI minimum ranged between 7.03 to 7.915.
Where in the south Al-Rasheed WTP, RI maximum ranged between 7.119 to 8.63 a

The present work considers an alternative solution for a complex configuration of rotor discs by applying Galerkin Method. The theoretical model consists of elastic shaft carrying number of discs and supported on number of journal bearings. The equation of motion was discretized to finite degree of freedom in terms of the system generalized coordinates. The various effects of the dynamical forces and moments arising from the bearing, discs and shaft were included. Rayleigh beam model is used for analyzing the shaft while the discs are considered rigid . The validity and convergence of the present analysis was carefully checked by comparing with the Finite Element solution. An example of rotor consists of three different size discs and su