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
Fri Nov 15 2024
Journal Name
Iraqi Journal Of Science
A Comparative Investigation of Different Ionospheric Models to Predict the MUF Parameter During Severe Geomagnetic Storm on 17th March 2015.
...Show More Authors

The present work aimed to make a comparative investigation between three different ionospheric models: IRI-2020, ASAPS and VOACAP. The purpose of the comparative study is to investigate the compatibility of predicting the Maximum Usable Frequency parameter (MUF) over mid-latitude region during the severe geomagnetic storm on 17 March 2015. Three stations distributed in the mid-latitudes were selected for study; these are (Athens (23.50o E, 38.00o N), Jeju (124.53o E, 33.6o N) and Pt. Arguello (239.50o W, 34.80o N). The daily MUF outcomes were calculated using the tested models for the three adopted sites, for a span of five-day (the day of the event and two days preceding and following the event day). The calculated datasets were co

... Show More
View Publication Preview PDF
Scopus (1)
Crossref (1)
Scopus Crossref
Publication Date
Sun Apr 30 2023
Journal Name
Al-kindy College Medical Journal
Prevalence of Burnout Syndrome and its Association with Job Title and Violence among Physicians in Baghdad: A Triangulated Methodology Study
...Show More Authors

Background: Economic Globalization affects work condition by increasing work stress. Chronic work stress ended with burnout syndrome. Objectives: To estimate the prevalence of burnout syndrome and the association of job title, and violence with it among physicians in Baghdad, and to assess the burnout syndrome at patient and work levels by structured interviews. Subjects and Methods: A cross section study was conducted on Physicians in Baghdad. Sampling was a multistage, stratified sampling to control the confounders in the design phase. A mixed qualitative and quantitative approach (triangulation) was used. Quantitative method used self-administered questionnaires of Maslach Burn out Inventory. Qualitative approach used an open-end

... Show More
Preview PDF
Scopus (1)
Scopus Crossref
Publication Date
Thu May 29 2025
Journal Name
Bmc Public Health
Coping skills and associated sociodemographic, clinical, and psychological factors among women with breast cancer in Iraq: a cross-sectional study”
...Show More Authors

Background: Coping skills play a vital role in managing the physical and psychological effects of breast cancer (BC). Despite improvements in early detection and treatment, Breast cancer survivors continue to face long-term challenges after diagnosis. Therefore, this study aims to evaluate the coping skills employed by breast cancer women in Iraq and to identify the sociodemographic, clinical, and psychological factors associated with these coping skills. Methods: A cross-sectional study was conducted among 244 breast cancer women in The Medical City Teaching Oncology Hospital, Baghdad, Iraq, from August 2023 to October 2023, coping skills and psychological factors were assessed using the BRIEF COPE-28, and Hospital Anxiety Depression scale

... Show More
View Publication
Scopus (2)
Crossref (1)
Scopus Crossref
Publication Date
Tue Dec 15 2020
Journal Name
Technologies And Materials For Renewable Energy, Environment And Sustainability: Tmrees20
A comparative study of Williamson-Hall method and size-strain method through X-ray diffraction pattern of cadmium oxide nanoparticle
...Show More Authors

In this research, the Williamson-Hall method and of size-strain plot method was employed to analyze X- ray lines for evaluating the crystallite size and lattice strain and of cadmium oxide nanoparticles. the crystallite size value is (15.2 nm) and (93.1 nm) and lattice strain (4.2 x10−4 ) and (21x10−4) respectively. Also, other methods have been employed to evaluate the crystallite size. The current methods are (Sherrer and modified Sherrer methods ) and their results are (14.8 nm) and (13.9nm) respectively. Each method of analysis has a different result because the alteration in the crystallite size and lattice strain calculated according to the Williamson-Hall and size-strain plot methods shows that the non-uniform strain in nan

... Show More
View Publication
Scopus (43)
Crossref (34)
Scopus Clarivate Crossref
Publication Date
Thu Aug 01 2024
Journal Name
Al-kindy College Medical Journal
Through the Eyes of Healthcare Providers, the Necessity and Challenges of Implementing Medication Reconciliation at Hospital Discharge: A Qualitative Study
...Show More Authors

Background: Medication reconciliation can include medication reviewing and providing counseling and a list of all the medications during every transition of care. Objectives: to explore in-depth the perspectives of Iraqi physicians and pharmacists regarding the necessity of medication reconciliation at hospital discharge and identify the possible benefits and challenges that could face its implementation. Subjects and Methods: A qualitative study included semi-structured interviews with pharmacists and physicians working at a public teaching hospital in Iraq. The interviews were conducted face-to-face from February to March 2023. Thematic analysis was used to analyze the qualitative data generated from the interviews. Results: In th

... Show More
Preview PDF
Crossref (2)
Scopus Crossref
Publication Date
Tue May 12 2026
Journal Name
Applied Science And Engineering Progress
Valorization of Lignin-Rich Meranti (Shorea sp.) Sawdust into Cellulose Nanocrystals via APS Pretreatment: A Severity Map and Operating Window
...Show More Authors

Developing routes to produce cellulose nanocrystals (CNCs) from high-lignin wood residues is essential for expanding sustainable nanocellulose feedstocks. In this work, Meranti (Shorea sp.) sawdust was valorized into CNCs by integrating ammonium persulfate (APS) pretreatment with subsequent sulfuric acid hydrolysis. To establish a severity map and define an operating window, APS pretreatment severity was systematically varied by adjusting APS concentration and the sawdust-to-APS (solid-to-liquid) ratio, and its influence on CNC structural properties was evaluated. APS pretreatment partially disrupted and oxidized the lignocellulosic matrix, enabling acid hydrolysis to liberate crystalline cellulose domains. XRD analysis confirmed th

... Show More
View Publication
Crossref
Publication Date
Wed Mar 01 2023
Journal Name
Journal Of Molecular Structure
Synthesis, structural investigations, XRD, DFT, anticancer and molecular docking study of a series of thiazole based Schiff base metal complexes
...Show More Authors

A novel Schiff base (SB) ligand, abbreviated as HDMPM, resulted from the condensation of 2-amino-4-phenyl-5-methyl thiazole and 4-(diethylamino)salicyaldehyde, and its metal complexes with [Co(II), Cu(II), Ni(II), and Zn(II)] ions in high yield were formed. The physico-chemical techniques such as elemental analysis, molar conductance, IR, 1H and 13C NMR, mass spectroscopy, and electronic absorption studies were utilized to characterize the synthesized compounds. The studied compounds were examined for their possible anticancer activity against a number of human cancerous cell lines, including A549 lung carcinoma, HepG2 liver cancer, HCT116 colorectal cancer, and MCF-7 breast cancer cell lines, with doxorubicin serving as the standard. The s

... Show More
View Publication
Scopus (42)
Crossref (37)
Scopus Clarivate Crossref
Publication Date
Sat Apr 30 2022
Journal Name
Biomedical Research And Therapy
Association between anti-collagen type II autoantibodies and the acute rheumatoid arthritis phenotype in a cohort of rheumatoid arthritis patients
...Show More Authors

View Publication
Scopus (3)
Crossref (4)
Scopus Clarivate Crossref
Publication Date
Wed May 31 2023
Journal Name
International Journal Of Sustainable Development And Planning
Prediction of Formal Transformations in City Structure (Kufa as a Model) Based on the Cellular Automation Model and Markov Chains
...Show More Authors

The research utilizes data produced by the Local Urban Management Directorate in Najaf and the imagery data from the Landsat 9 satellite, after being processed by the GIS tool. The research follows a descriptive and analytical approach; we integrated the Markov chain analysis and the cellular automation approach to predict transformations in city structure as a result of changes in land utilization. The research also aims to identify approaches to detect post-classification transformations in order to determine changes in land utilization. To predict the future land utilization in the city of Kufa, and to evaluate data accuracy, we used the Kappa Indicator to determine the potential applicability of the probability matrix that resulted from

... Show More
View Publication
Scopus (9)
Crossref (2)
Scopus Crossref
Publication Date
Thu Aug 04 2022
Journal Name
Journal Of Nanomaterials
Thermal Management of the Melting Process in a Latent Heat Triplex Tube Storage System Using Different Configurations of Frustum Tubes
...Show More Authors

In this study, the energy charging mechanism is mathematically modeled to determine the impact of design modifications on the thermofluidic behavior of a phase change material (PCM) filled in a triplex tube containment geometry. The surface area of the middle tube, where the PCM is placed, is supported by single or multi-internal frustum tubes in vertical triplex tubes to increase the performance of the heating and cooling of the system. In addition to the ordinary straight triplex tubes, three more scenarios are considered: (1) changing the middle tube to the frustum tube, (2) changing the inner tube to the frustum tube, and (3) changing both the internal and central tubes to the frustum tubes. The impact of adopting the tube desig

... Show More
View Publication
Scopus (63)
Crossref (57)
Scopus Clarivate Crossref