In this paper, variable gain nonlinear PD and PI fuzzy logic controllers are designed and the effect of the variable gain characteristic of these controllers is analyzed to show its contribution in enhancing the performance of the closed loop system over a conventional linear PID controller. Simulation results and time domain performance characteristics show how these fuzzy controllers outperform the conventional PID controller when used to control a nonlinear plant and a plant that has time delay.

Abstract  

All central air conditioning systems contain piping system with various components, sizes, material, and layouts. If such systems in operating mode, the flow in piping system and its component such as valves can produce severe vibration due to some flow phenomenon’s. In this research, experimental measurements and numerical simulation are used to study the flow-induced vibration in valves. Computational fluid dynamics (CFD) concepts are included with one-way and two-way fluid-structure interaction concepts by using finite element software Package (ANSYS 14.57). Detection analysis is performed on flow characteristics under operation conditions and relations with structural vibration. Most of

Global warming has had considerable effects on vital ecosystems, which has also been caused by increased temperatures and CO₂ that follow changes in different abiotic factors, which poses threats to mangrove forests environment. This research was conducted to examine the physiological and morphological characteristics of the Rhizophora apiculata mangrove regarding higher air temperature for the variety of tree species that respond to climate change. Seedlings were cultivated for three months in regulated growth chambers with three varying temperatures of 38°C, 21°C under CO₂ at 450 ppm, and ambient CO₂ concentration i.e., 450 ± 20 ppm under average temperature at 28°C as the control condition

Experimental and numerical investigations of the centrifugal pump performance at non-cavitating and cavitating flow conditions were carried out in the present study. Experiments were performed by applying a vacuum to a closed-loop system to investigate the effects of the net positive suction head available (NPSHa), flow rate, water temperature and pump speed on the centrifugal pump performance. Accordingly, many of the important parameters concerning cavitation phenomenon were calculated. Also, the noise which is accompanied by cavitation was measured. Numerical analysis was implemented for two phase flow (the water and its vapor) using a 2-D simulation by ANSYS FLUENT software to investigate the internal flow of centrifugal pump under c

The effects of essential oilNigella sativa and Menthawas study on the chemical, microbial and sensory properties for soft white cheese that produced from it during storage at 0, 7 and 14 days .The results show significantly percent decrease in moisture for all samplesand maximum decrease was at the latest storage period for all them .The reduced in moisture was accompanied with increase in percentage of protein and fat during of storage period for all samples.
The control sample showed increased in bacterial logarithmic for total count bacterial, coliform, Staphylococcus aureus, proteolytic bacteria, lipolytic bacteria and mold and yeasts during of storage period , the highest results showed at the latest storage period 14days, it w

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Background: Age determination of skeletal remains is apart of many medico-legal as well as anthropological examination. Many anatomical structures have been studied, but the teeth and their measurements seem to be the most reliable method since teeth represent the most durable and resilient part of the skeleton. This study was undertaken for estimating the chronological age among Iraqi adult subjects based on various morphological variables of canine teeth using digital panoramic radiograph. Material and methods: The sample in the current study consisted of 240 Iraqi patients attending to the dental radiological clinic at College of dentistry/ Babylon University taking panoramic radiographs for different diagnostic purposes, the study samp

Background: Consanguineous marriage is a relationship between biologically related individuals. Genetic factors have a role in gene environment interactions that takes the center stage. The evidence of oral disease (gingivitis and periodontitis) may depend on genetic syndromes, inherited diseases, familial studies etc. The present study aims at assessing dental plaque and gingival health condition in children of inbreeding parents compared with children of outbreeding parents among primary schools in Al-Qasem city/ Babylon governorate in Iraq. Materials and methods: this comparative study included three hundred ninety eight (398) students, 6-12 years old, from 4 primary schools; 199 children had their parents of inbreeding marriage with