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 May 01 2020
Journal Name
Journal Of Engineering
Parametric Study on Unconnected Piled Raft Foundation Using Numerical Modelling
...Show More Authors

Piled raft is commonly used as foundation for high rise buildings. The design concept of piled raft foundation is to minimize the number of piles, and to utilize the entire bearing capacity. High axial stresses are therefore, concentrated at the region of connection between the piles and raft. Recently, an alternative technique is proposed to disconnect the piles from the raft in a so called unconnected piled raft (UCPR) foundation, in which a compacted soil layer (cushion) beneath the raft, is usually introduced.  The piles of the new system are considered as reinforcement members for the subsoil rather than as structural members. In the current study, the behavior of unconnected piled rafts systems has been studie

... Show More
View Publication Preview PDF
Crossref (6)
Crossref
Publication Date
Fri Jul 21 2023
Journal Name
Journal Of Engineering
FINITE ELEMENT ANALYSIS OF HUMAN AND ARTIFICIAL ARTICULAR CARTILAGE
...Show More Authors

Joint diseases, such as osteoarthritis, induce pain and loss of mobility to millions of people around the world. Current clinical methods for the diagnosis of osteoarthritis include X-ray, magnetic resonance imaging, and arthroscopy. These methods may be insensitive to the earliest signs of osteoarthritis. This study investigates a new procedure that was developed and validated numerically for use in the evaluation of cartilage quality. This finite element model of the human articular cartilage could be helpful in providing insight into mechanisms of injury, effects of treatment, and the role of mechanical factors in degenerative
conditions, this three-dimensional finite element model is a useful tool for understanding of the stress d

... Show More
View Publication Preview PDF
Crossref
Publication Date
Sun Jul 02 2023
Journal Name
Iraqi Journal Of Science
Promethazine-HCl Determination Using Entrapped Persulphate in Water Crystals by Flow Injection / Stopped - Flow Technique and Ayah 3SX3-3D Solar Cell Micro Photometer
...Show More Authors

A new mode of methodology was adopted in the assay of PM- HCL based on the use of water crystal gel bead made of poly acrylic acid in which the gel beads were left to absorbe persulphate solution that is necessary for the oxidation of PM- HCL in aqua media . The water crystal act as a reserviour for S2O82- . Optimum parameters were studied giving to specify the chemical and physical parameters. Two line manifold was used .The flow rates of 1.5 and 1.2 ml.min-1 was used , 3 gel beads , 120 μL sample volume , a linear dynamic range extend from 0.01- 18 mmol.L-1. A correlation coefficient (r) of 0.9991while the percentage linearity (r2%) of 99.82% with R.S.D% at 8 mmol.L-1 promethazine-HCl is less than 0.5% (ten replicates) and a detection

... Show More
View Publication Preview PDF
Publication Date
Fri Nov 02 2018
Journal Name
Iraqi National Journal Of Nursing Specialties
Impact of Maternal Risk Factors on Birth Weight of Newborn in Two Maternity Hospitals in Baghdad City
...Show More Authors

Objectives: A cross sectional analytic study was carried out to identify the maternal risk factors which
contribute to occurrence of low birth weight, and to determine the statistical significant differences between low
birth weight and maternal risk factors.
Methodology: A purposive sample of (400) woman was selected from AL-Elwyia Maternity Teaching Hospital
and Fatima Al-Zaharia Maternity and Pediatric Teaching Hospital. Data was collected through the interview of
mothers. Questionnaire format was designed and consisted seven parts, demographic variables, and reproductive
variables , Reproductive health variables, complications during the current pregnancy, the mother newborn
variables nutritional status for the m

... Show More
View Publication Preview PDF
Publication Date
Fri Jun 24 2022
Journal Name
Iraqi Journal Of Science
Biological activity of some plants extract against in the survival of rate adult Oryzaephilus surinamensis (Coleopteran Silvanaidae)
...Show More Authors

A laboratory study was conducted to evaluate the effect of crud extracts from seven plant species (Nigella sativa, Eugenia caryophylota, Corianderum sativum, Piper nigrum, Peganum hermala, Achillea santolina, Citrullus colocynthis) belong to different families tested as food feeding toxicity against adult of Oryzaephilus surinamensis. The results of the current study showed that hexane extracts from all plants used were more influential in all used concentrations than, the alcoholic extract, and hexane extract of Hanzal was more effective reaching survival rate of adult to 58.3% at concentration of 10% then the plant yarrow and black pepper about 66.2%, and 67.3% respectively, at the same concentration. While the survival rate was approx

... Show More
View Publication Preview PDF
Publication Date
Fri Nov 24 2023
Journal Name
Iraqi Journal Of Science
Effect of Orange Peel (Citrus sinensis) (L) extrcts and powder on confused flour beetle Tribolum confusum (Coleoptera: Teneberionidae)
...Show More Authors

This study was carried out to determine the effect of extras of orange peel of (Citrus sinensis) in concentrations (1,5, 10) % as well as stomachic effect for the powder of the plant with doses of 5,10 , 15/gm on the biological activities of the adults of Tribolim confusum . The effect of powder from the adults has been evaluated using different concentrations of the orange peel. The results showed that the powder have significant effect on the mortality rates of adults. and caused reduction in number of adults after 3 days with 5,10,15/gm killed (30,40, 43.3)% respectively. The use of different doses of Citrus sinensis peels powder not impact significantly after just one day. The extract of essential oil also caused growth inhibition in

... Show More
View Publication Preview PDF
Publication Date
Fri May 01 2020
Journal Name
Journal Of Engineering
Improvement of the Rheological and Filtration Properties of Drilling Mud Using the Syrian Clay
...Show More Authors

Drilling fluid properties and formulation play a fundamental role in drilling operations. The Classical water-based muds prepared from only the Syrian clay and water without any additives((Organic and industrial polymers) are generally poor in performance. Moreover, The high quantity of Syrian clay (120 gr / l) used in preparing drilling fluids. It leads to a decrease in the drilling speed and thus an increase in the time required to complete the drilling of the well. As a result, the total cost of drilling the well increased, as a result of an increase in the concentration of the solid part in the drilling fluid. In this context, our study focuses on the investigation of the improvement in drilling mud   Prepa

... Show More
View Publication Preview PDF
Crossref (1)
Crossref
Publication Date
Sun Mar 06 2016
Journal Name
Baghdad Science Journal
Molecular Identification of Rhizosphere Trichoderma spp. and Their Antagonistic Impact Against Some Plant Pathogenic Fungi
...Show More Authors

The main aim of this study was to molecular identification and determine the antagonistic impact of rhizosphere Trichoderma spp. against some phytopathogenic fungi, including (Magnaporthe grisea) pyricularia oryzae, Rhizoctonia solani and Macrophomina phasolina. Four Trichoderma isolates were isolated from rhizosphere soils of the different host plants in different locations of Egyptian governorates. The morphological characterization of isolated Trichoderma as well as using of (ITS1-5.8S-ITS2) ribosomal gene sequence acquisition and data analyses. By comparing the results of DNA sequences of ITS region, the fungi represented one isolate were positively identified as T. asperellum (1 isolate T1) and one as T. longibrachiatum (1 isolate T2)

... Show More
View Publication Preview PDF
Crossref
Publication Date
Sun Jul 31 2022
Journal Name
Iraqi Journal Of Science
Association of CTLA-4 Single Nucleotide Polymorphisms with Autoimmune Hypothyroidism in Iraqi Patients
...Show More Authors

Genetic and environmental factors are believed to have a key role in the development and pathogenesis of autoimmune thyroid diseases (AITD). This study aimed to investigate the association between two CTLA-4 gene single nucleotide polymorphisms (SNPs) CT60/rs3087243 and CT61/rs11571319 with autoimmune thyroiditis in a sample of Iraqi patients. Seventy-five patients (67 females, 8 males) and eighty-eight subjects (79 females and 9 males) matched in age, gender, and ethnicity as a control group. Thyroid autoantibodies were present in females more than in males with a total positivity of anti-TPO of 92% and anti-TG positivity of
57.3 %. Thyroid evaluation tests including T3, T4, and TSH were abnormal only in patients not receiving L-th

... Show More
View Publication Preview PDF
Scopus (7)
Crossref (2)
Scopus Crossref
Publication Date
Sat Jan 01 2022
Journal Name
Journal Of The Mechanical Behavior Of Materials
The slenderness ratio effect on the response of closed-end pipe piles in liquefied and non-liquefied soil layers under coupled static-seismic loading
...Show More Authors
Abstract<p>This study presents the findings of a 3D finite element modeling on the performance of a single pile under various slenderness ratios (25, 50, 75, 100). These percentages were assigned to cover the most commonly configuration used in such kind of piles. The effect of the soil condition (dry and saturated) on the pile response was also investigated. The pile was modeled as a linear elastic, the surrounded dry soil layers were simulated by adopting a modified Mohr-Coulomb model, and the saturated soil layers were simulated by the modified UBCSAND model. The soil-pile interaction was represented by interface elements with a reduction factor (R) of 0.6 in the loose sand layer and 0.7 in t</p> ... Show More
Scopus (9)
Crossref (5)
Scopus Clarivate Crossref