The Sliding Mode Control (SMC) has been among powerful control techniques increasingly. Much attention is paid to both theoretical and practical aspects of disciplines due to their distinctive characteristics such as insensitivity to bounded matched uncertainties, reduction of the order of sliding equations of motion, decoupling mechanical systems design. In the current study, two-link robot performance in the Classical SMC is enhanced via Adaptive Sliding Mode Controller (ASMC) despite uncertainty, external disturbance, and coulomb friction. The key idea is abstracted as follows: switching gains are depressed to the low allowable values, resulting in decreased chattering motion and control's efforts of the two-link robot system. Un-known uncertainty bounded and reducing switching gains can be considered major advantages of ASMC leading to outperform ASMC upon CSMC. Simulink MATLAB 2019a was used to obtain the simulation outcomes. The outcomes have shown that both methodologies had good tracking performance to the desired position and made the system asymptotically stable through the steady-state errors investigate approaching zero. ASMC is better than CSMC illustrated by minimizing gains values, control efforts, and chattering for each link.
In this work chemical vapor deposition method (CVD) for the production of carbon nanotubes (CNTs) have been improved by the addition of S. Steel mesh container (SSMC) inside which the catalyst (Fe/Al2O3) was placed. Scanning electron microscopy (SEM) investigation method used to study nanotubes produced, showed that high yield of two types of (CNTs) obtained, single wall carbon nanotube (SWCNTs) with diameter and length of less than 50nm and several micrometers respectively and nanocoil tubes with a diameter and length of less than 100nm and several micrometers respectively. The chemical analysis of (CNTs) reveals that the main component is carbon (94%) and a little amount of Al (0.32%), Fe (2.22%) the reminder is oxygen. It was also fou
... Show MoreUsed vegetable oil was introduced to transesterfication reaction to produce Biodiesel fuel suitable for diesel engines. Method of production was consisted of filtration, transesterfication, separation and washing. Transesterfication was studied extensively with different operating conditions, temperature range (35-80oC), catalyst concentration (0.5-2 wt. % based on oil), mixing time (30-120 min.) with constant oil/methanol weight ratio 5:1 and mixing speed 1300 rpm. The concentration of Fatty acid methyl esters (Biodiesel) was determined for the transesterficated oil samples, besides of some important physical properties such as specific gravity, viscosity, pour point and flash point. The behavior of methyl esters production and the physica
... Show MoreThis study deals with Aphid predators of the genus Coccinella L. recognized in different
regions of the world. They have been arranged systematically according to Korschefsky’s
catalogue (1931). The list includes sites of study and the reference (works) that consider
Coccinellids as predator. The study has revealed that there are thirteen Aphid predator species
belonging to the genus Coccinella L. in different places of the world, although there might be
other species that were not recorded by this work.
Leishmaniasis is one of the neglected parasitic diseases, which belongs to the family Trypanosomatidae. Cutaneous leishmaniasis is endemic in Iraq and the available drugs are of side effect or resistant by the parasite. In this study, cytotoxicity of methotrexate was investigated on the promastigotes proliferation of the Iraqi strain ofL.tropica.The results showed a significant (p ≥ 0.05) difference in growth of treated groupsat all concentration (1000, 500, 250, 125.5, 62.5, 31.25, 15.6) μM, after 24 and 48 hours of follow up, while after 72 hours, significant difference was observed at concentration(1000, 125, 62.5) μM.The IC50 measured after 24and 48 hours and it was 40.366 and 44.452 μM, respectively.The present study showed
... Show MoreIt is uncertain whether terminal ileum intubation should be performed routinely during colonoscopy, as there is uncertainty regarding its diagnostic value. The aim of the present study is to assess the diagnostic yield of terminal ileum intubation during colonoscopy according to indications for colonoscopy. This is a cross-sectional study in which the results of 294 total colonoscopy procedures were reviewed; ileal intubation was performed in 269 (91.49%) patients. The indications for colonoscopy, the results of ileoscopy, and the histopathological results of ileal biopsies were evaluated.
A total of 54 (20%) out of 269 patients who had successful intubation into the terminal ileum sh
Pollen morphology of 4 species (A. aucheri , A. auriculata, A. caucasica, A. nova) belonging to the genus Arabis L. in Iraq was examined by light microscope and scanning electron microscope to determine the significance of pollen features as a taxonomic characters. The results showed pollen grains of the species were monades, homopolar, tricolpate, and with medium size, but the species varied in shapes (polar and equatorial view), colpus length and width, exine thickness and exine ornamentation. Pollen colors were brown convert to brownish yellow.
Reading strategies are of interest for what they reveal about the ways readers manage their interaction with written texts and how these strategies are related to text understanding, acquisition ,storage ,and retrieval of information .In EFL comprehension lessons, the students try to work out interpretations of the meaning related to the written word through the usage of different comprehension strategies. Yet, there are moments where the participants in the classroom fail to reach a successful understanding of the passage read despite the guidance of the teacher. The present research aims at investigating and identifying moments of comprehension failure and reasons behind them .It also aims at specifying the different strategies used in
... Show MoreObjective: The purpose of this work was to develop and optimize the emulgel formulation of piroxicam with two types of gelling agent chitosan and xanthan gum. The release profiles of prepared formulas were investigated. In addition, the rheology and stability of the best formula were investigated.Methods: Emulsified piroxicam was prepared to use oleic acid, tween 80 and PG with a ratio (3:10:10). In xanthan based emulgel, the xanthan gum (1% and 1.5%) was spread as powder on emulsified piroxicam with stirring until emulgel was formed. In chitosan-based emgels, Chitosan gel was added to emulsified piroxicam and stirring until the Emulgel was constructed. Chitosan gels were prepared by incorporating different concentration, 2%, 3%, 6%
... Show MoreThis research deals with the formalities of the mortgage contract according to American law, We have given an overview of the provisions of this law related to the subject, We have also taken into consideration the role of American jurisprudence and the judiciary in finding legal solutions to the aforementioned formality, We have discussed the formality of mortgage in American law in two sections, In the first section we showed the formalism in immovable mortgage, and the second section specified to studying the formalism in movable mortgage.
Image compression is an important tool to reduce the bandwidth and storage
requirements of practical image systems. To reduce the increasing demand of storage
space and transmission time compression techniques are the need of the day. Discrete
time wavelet transforms based image codec using Set Partitioning In Hierarchical
Trees (SPIHT) is implemented in this paper. Mean Square Error (MSE), Peak Signal
to Noise Ratio (PSNR) and Maximum Difference (MD) are used to measure the
picture quality of reconstructed image. MSE and PSNR are the most common picture
quality measures. Different kinds of test images are assessed in this work with
different compression ratios. The results show the high efficiency of SPIHT algori