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Go to Editorial ManagerAfter long eras of socialism, wars and economic embargo when Iraqi people were severely exhausted, Iraq finally adopts free market economy. Its Gross Domestic Product (GDP) increased rapidly.The fortune was to flow in a proper frame of legislations to Iraqis.Since wealth needs time to grow for a person, and housing commodity is of high costs, then legislation were to be issued to organize flow of the national wealth to support private sector in housing finance.In respond, the Law of Iraqi Housing Bank (IHB) No. 32 was issued in 2011.This research is to solve the conflicts of the (IHB) Law and to support Iraqi legislators regarding this aspect. This research claims that this law should be revised by the Iraq Parliament. The research comes to help in this mission. The law of (IHB) should not conflict with The Iraqi Constitution.The range of this research is the “Status-in-force” Iraqi legislations only.It discusses the housing finance relations in various Iraqi legislations.
The heat exchanger is a device used to transfer heat energy between two fluids, hot and cold. In this work, an output feedback adaptive sliding mode controller is designed to control the temperature of the outlet cold water for plate heat exchanger. The discontinuous gain value of the sliding mode controller is adapted according to a certain adaptation law, where the only information required is the measurement of the outlet cold temperature. A sliding mode differentiator was design to estimate time derivative of outlet hot water temperature. Two constraints which imposed on the volumetric flow rate of the hot water (control input) were considered within the rules of the proposed adaptation law in this work. These are the control input is positive only and has a maximum value. For constructing the sliding variable, the outlet hot water temperature and its time derivative are required. The maximum allowable desired outlet cold water has been estimated as function of heat exchanger parameters and maximum control input. The simulation results demonstrate the performance of the proposed adaptive sliding mode control where the outlet cold water was forced to follow desired temperature equal to . Additionally, the robustness of the proposed controller was tested for the case where the cold inlet temperature is not constant. The results reveal the robustness of the proposed controller.
The free vibration analysis of rotating multi-layered cylindrical shell is investigated based on the first order shear deformation theory (FSDT) of shell. Cylindrical shell consists of three layers; outer and inner layers are isotropic material and the middle layer is a functionally graded material (FGM). The material properties for middle layer are assumed to be graded in the thickness direction. Based on Hamilton’s principle, the equilibrium equations and the equations of motion are derived and then solved by using the differential quadrature method (DQM) as a numerical tool. MATLAB software was adopted for programming the equations and the related boundary condition. The effect of (FGM) layer thickness, angular speed, index power law, circumferential wave number on the natural frequency of the clamped-clamped rotating cylindrical shell were examined. The numerical results showed that a reasonable agreement between the present study and analytical data available in the literature.
This paper presents a numerical investigation to study the effect of variations in displacement history sequence and magnitude on cyclic response of RC tapered (haunched) beams (RCHBs).Five simply supported RCHBs (four haunched and one prismatic) were selected from experimental work carried out by Aranda et al. The selected variables included were five loading history types. The first part of this study focused to verify the finite element analysis with selected experimental work and the second part of this study focused too studying the effect of varying in loading history to the response of RCHBs. The finite element code Abaqus was used in the modeling. The adopted cyclic simulation performance of the selected beams using the plastic- damage model for concrete developed by Lubliner and Lee & Fenves. The constitutive model of plain concrete describing the uniaxial compression response under cyclic loading proposed by Thorenfeldt, and the uniaxial tension response follows the softening law proposed by Hordijk was used in the modeling. Menegotto-Pinto model was used to simulate the steel response. Model verification has shown A good agreement to the selected experimental work. The variations in loading history will decrease the ultimate load and corresponding deflection with increase in the number of cycles at ultimate load.
A substantial amount of research has been dedicated to improving the efficiency of heat exchangers, which are extensively utilized in electronic equipment, heating and air conditioning systems, space vehicles, thermal power systems, industrial applications, and transportation. Enhancing the efficiency of these devices can lead to significant reductions in materials, cost, and space. Constructal design offers a promising approach to optimizing various heat transfer systems, including electronic packages, by applying the constructal law to achieve optimal configurations. This review aims to examine recent advancements in the application of constructal design theory to heat exchangers and its potential for enhancing thermal performance. The most recent state-of-the-art developments are thoroughly described, along with their evaluating parameters, and recommendations for further research in this field are provided.