Preferred Language
Articles
/
joe-145
Sliding Mode Vibration Suppression Control Design for a Smart Beam
...Show More Authors

Active vibration control is the main problem in different structure. Smart material like piezoelectric make a structure smart, adaptive and self-controlling so, they are effective in active vibration control. In this paper piezoelectric elements are used as sensors and actuators in flexible structures for sensing and actuating purposes, and to control the vibration of a cantilever beam by using sliding mode control. The sliding mode controller (SMC) is designed to attenuate the vibration induced by initial tip displacement which is equal to 15 mm.  It is designed based on the balance realization reduction method where three states are selected for the reduced model from the 24th states that describe the cantilever beam according to the FEM. These states are most controllable and observable. The stability and control performance for the proposed SMC are proved using candidate Lyapunov function and the equivalent control concept. The control spillover, which is the sources of instability, is completely avoided as ensured within the control performance proof.

            Numerical simulations are preformed to test the vibration attenuation ability of the proposed SMC. For 15 mm initial tip displacement, the piezoelectric actuator was found able to reduce the tip displacement to about (0.2) mm within (2.5 s), while it is equal to (3.5) mm with the open loop case. Moreover, the induced chattering in system response, due to the discontinuous control action, is removed by approximating the signum function by a continuous arctan function. As a result  a smoother response are obtained with the same control performance as can be shown in the sliding variable, the control input voltage and the tip displacement plots.

 

 

View Publication Preview PDF
Quick Preview PDF
Publication Date
Sun Mar 01 2020
Journal Name
مجلة البحوث والدراسات الإسلامية
Religious and Psychological guidance in the Qur’an and Sunnah, a descriptive study
...Show More Authors

God saw his servants with truth and light, and made him easy for them, and he commanded those who help them, including a counselor, guide and preacher, so if a Muslim sees deficiencies or defects, he must help him to reform and refine it. That it was in the hands of the prophets, God Almighty created the human being together straight, then melted on those scholars and researchers in all religions on psychological counseling and religious sychotherapy, stressing the importance of religious values in the process of understanding man in the process of psychotherapy and in controlling human behavior. A lot of research and studies have been published. I dealt with the religious approach in the process of treating mental disorders and the aim of

... Show More
Publication Date
Mon Jan 02 2023
Journal Name
International Journal Of Nonlinear Analysis And Applications
Diagnostic COVID-19 based on chest imaging of COVID-19: A survey
...Show More Authors

Publication Date
Fri Mar 15 2019
Journal Name
Journal Of The College Of Education For Women
A Cognitive Linguistic Study of the Satirical Language in Al-Hajjar's Caricatures
...Show More Authors

The present study is a qualitative study that aims to investigate the way the Iraqi caricaturist,Dheaa Al-Hajjar uses caricatures to produce a satirical meaning humorously.Producing satire while at the same maintaining humor requires a creative thinking on the part of the caricaturist. Thus, the study examines the production of humorous satire in terms of creativity. The analysis is done from the cognitive linguistic point of view using Arthur Koestler's theory of bisociation as presented in his book The Act of Creation in 1964. The main principle on which the theory is based is that humor is created via linking (or bisociating in Koestler's terms) two habitually incompatible trains of thought in order to come up with a novel me

... Show More
View Publication Preview PDF
Publication Date
Sun Jan 01 2023
Journal Name
Česká A Slovenská Farmacie
Hyperferritinemia as a factor associated with poor prognosis in COVID-19 patients
...Show More Authors

Worldwide, hundreds of millions of people have been infected with COVID-19 since December 2019; however, about 20% or less developed severe symptoms. The main aim of the current study was to  assess  the  relationship  between  the  severity of Covid-19 and different clinical and laboratory parameters. A total number of 466 Arabs have willingly joined this prospective cohort. Out of the total number, 297 subjects (63.7%) had negative COVID-19 tests, and thus, they were recruited as controls, while 169 subjects (36.3%) who tested positive for COVID-19 were enrolled as cases. Out of the total number of COVID-19 patients, 127 (75.15%) presented with mild symptoms, and 42 (24.85%) had severe symptoms. The age range for the partic

... Show More
View Publication
Scopus Crossref
Publication Date
Tue Dec 01 2015
Journal Name
Solar Energy
A review of studies on using nanofluids in flat-plate solar collectors
...Show More Authors

Continuous escalation of the cost of generating energy is preceded by the fact of scary depletion of the energy reserve of the fossil fuels and pollution of the environment as developed and developing countries burn these fuels. To meet the challenge of the impending energy crisis, renewable energy has been growing rapidly in the last decade. Among the renewable energy sources, solar energy is the most extensively available energy, has the least effect on the environment, and is very efficient in terms of energy conversion. Thus, solar energy has become one of the preferred sources of renewable energy. Flat-plate solar collectors are one of the extensively-used and well-known types of solar collectors. However, the effectiveness of the coll

... Show More
Scopus (137)
Crossref (127)
Scopus Clarivate Crossref
Publication Date
Fri Oct 20 2023
Journal Name
Al-ameed Journal For Medical Research And Health Sciences
Perceptions of Nursing Students about COVID-19 Transmission: A Multi University Study
...Show More Authors

Publication Date
Sun Jun 30 2024
Journal Name
Iraqi Journal Of Science
Gray-Scale Image Compression Method Based on a Pixel-Based Adaptive Technique
...Show More Authors

     Today in the digital realm, where images constitute the massive resource of the social media base but unfortunately suffer from two issues of size and transmission, compression is the ideal solution. Pixel base techniques are one of the modern spatially optimized modeling techniques of deterministic and probabilistic bases that imply mean, index, and residual. This paper introduces adaptive pixel-based coding techniques for the probabilistic part of a lossy scheme by incorporating the MMSA of the C321 base along with the utilization of the deterministic part losslessly. The tested results achieved higher size reduction performance compared to the traditional pixel-based techniques and the standard JPEG by about 40% and 50%,

... Show More
View Publication
Scopus (2)
Crossref (2)
Scopus Crossref
Publication Date
Tue Dec 30 2014
Journal Name
College Of Islamic Sciences
Approaches to the formation of a contemporary explanatory mindset: Critical inductive study
...Show More Authors

The issue of the development of Qur'anic studies for the tasks, and the first thought of minds and multiple understandings, and the most precious ideas, and the alternatives were floated, and varied visions, especially as we live in an era exploding knowledge, and complicate secretions, and scramble his ideas, and to devise intellectual approaches To achieve the witnesses of civilization in the words of the Almighty (to be martyrs on the people) Surat Al - Baqarah / 143 attendance and participation in the achievement and a positive interaction with the participants of humanity and civilization in the light of the meaning (to know) rooms / 13.
Therefore, we must emerge from the one-dimensional view of the Koran to the complex mindset t

... Show More
View Publication Preview PDF
Publication Date
Wed Mar 29 2017
Journal Name
Iraqi Journal Of Pharmaceutical Sciences ( P-issn 1683 - 3597 E-issn 2521 - 3512)
Application of Seed Mucilage Extracted from Lallemantia royleana as a Suspending Agent
...Show More Authors

The mucilage from the seeds of Lallemantia royleana family Labiatae was extracted and subjected to preformulation study for evaluation of its suitability for use as suspending agent. Furosemide suspensions were prepared using (1.5% w/v) of the extracted Lallemantia royleana mucilage, (1.5% w/v) chitosan and (0.35% w/v) xanthan gum. The mucilage was white in color and the average yield of dried mucilage obtained from L.royleana nutlets was 14 % w/w of the seeds used. It is sparingly soluble in water but swells in contact with it, giving a highly viscous solution. It is slightly acidic to neutral. It was found that the extracted natural mucilage of Lallemantia royleana exhibited a higher viscosity profil

... Show More
View Publication Preview PDF
Crossref (8)
Crossref
Publication Date
Tue Jan 30 2024
Journal Name
Iraqi Journal Of Science
A Study of Drinking Water Properties in Some Hospitals in Baghdad City
...Show More Authors

One of the bigger problems in drinking water is disinfection by-products (DBPs) that come from chlorinated disinfection. This study’s goal was to evaluate the drinking water in Al-Yarmouk Teaching Hospital, Ibn Sina Hospital and Ibn-Al-Nafis Hospital.  Samples were collected between October 2018 and September 2019. Physical and chemical characteristics of the water were studied, including (temperature, hydrogen ion (pH), total dissolved solids (TDS), electrical conductivity (EC), turbidity, free residual chlorine, total organic carbon (TOC), total trihalomethanes (THMs), total halo acetic acid (THAAs)). Data analysis showed the highest value of study temperature, pH, TDS, EC, turbidity, free residual chlorine and TOC which was

... Show More
View Publication
Scopus (2)
Scopus Crossref