A decentralized proportional-integral sliding mode tracking controller for a 2 D.O.F robot arm

Trajectory tracking with high accuracy is a very challenging topic in direct drive robot control. This is due to the nonlinearities and input couplings present in the dynamics of the arm. This paper deals with the tracking control of a class of direct-drive robot manipulators. A robust Proportional-Integral (PI) sliding mode control law is derived so that the robot trajectory tracks a desired trajectory as closely as possible despite the highly non-linear and coupled dynamics. The controller is designed using the decentralized approaches. Application to a two degree of freedom direct drive robot arm is considered

Numerical Concepts between the Reality of Elementary Students' Understanding and their Teachers' Beliefs towards this Understanding in Saudi Arabia

The aim of the study was to identify the understanding of elementary school students of numerical concepts, and the beliefs of their teachers about this understanding. To achieve this goal, the content of the mathematics sixth grade textbook was analyzed to identify the numerical concepts. Then, a conceptual diagnostic test consisting of 24 multiple-choice questions to measure the understanding of numerical concepts was designed. Another questionnaire was built to measure the teachers' beliefs about their students understanding of these concepts. The teachers' questionnaire included 24 concepts as well. The sample size was 1411 male and female students; and the sample size of teachers was 528 mathematics teachers. Both were drawn randomly from three cities in the Kingdom of Saudi Arabia. The test of students showed that about 4.2% of the numerical concepts were highly understandable, whereas the questionnaire showed that teachers believed their students understood 17% of the concepts. Furthermore, students moderately understood about 37.5% of the concepts, while the questionnaire showed that teachers believed their students moderately undersood about 83% of the concepts. Moreover, the test showed that about 58.3% of the concepts were poorly understood, whereas the questionnaire showed that there were no concepts that would be poorly understood. The study found that there were statistically significant differences due to gender, credential, and experience; however, there was no statistically significant difference attributed to training on teachers' beliefs about students' understanding of mathematics

Androgen receptor and ultrastructural features of Nigella sativa oil and nicotine-treated male rat reproductive glands

Nicotine is claimed to increase free radicals, DNA damage and lipid peroxidation in male reproductive organs. Nigella sativa has been identified to ameliorate these adverse effects due to nicotine intake. This study was conducted to evaluate potential protective effects of N. sativa oil on the adverse effects of nicotine on androgen receptors (AR) and ultrastructural features of rat seminal vesicles and prostate glands. Twenty four Sprague Dawley male rats, 7-9 weeks of age and 200-250 g body weight (BW) were randomly divided into; Group 1 Saline (S), forced fed with 0.1 mL/100 g BW of 0.9% normal saline; Group 2 Nicotine (N), intramuscularly injected with 0.5 mg/100 g BW of nicotine; Group 3 N. sativa (NS), forced fed with 6.0 μL/100 g BW of N. sativa and Group 4 Nicotine-N. sativa (NNS), co-administered with 0.5 mg/100 g BW of nicotine and 6.0 μL/100 g BW of N. sativa. The seminal vesicles and prostate glands were extracted after 100 days of treatment. The seminal vesicle and prostate gland were processed for ultrastructural study and androgen receptor detection. The epithelial cells in prostate gland and seminal vesicle of the N group showed weaker brown staining intensity as compared to that of in the NS and NNS groups. This was consistent with the presence of some ultracellular changes observed in the prostate gland and seminal vesicle tissues of the N group. Findings from this study suggested that administration of N. sativa results in ameliorating effects on both the prostate gland and seminal vesicle structures and functions of the nicotine-treated rats

Unilateral, trifocal, diaphyseal fracture of the radius with ipsilateral mid-shaft ulna fracture in an adult: a case report

<p>Abstract</p> <p>Introduction</p> <p>To the best of our knowledge, a trifocal, diaphyseal fracture of the radius associated with ipsilateral mid-shaft fracture of the ulna in an adult has not been reported in the literature to date. The AO classification system does not include such a fracture configuration.</p> <p>Case presentation</p> <p>We report a case of trifocal, diaphyseal fracture of the radius with a mid-diaphyseal fracture of the ulna in a 53-year-old Caucasian, British, right-hand dominant woman involved in a head-on collision with another vehicle. The management of this rare fracture configuration is described and alternative treatment options discussed.</p> <p>Conclusions</p> <p>We describe an unusual, complex fracture, which with prompt surgical treatment resulted in a rapid, full and satisfactory functional recovery for our patient.</p

SYNTHESIS, CHARACTERIZATION AND BIOLOGICAL ACTIVITY OF POLYMER NICKEL (II) COMPLEX

4-vinyl pyridine nickel complex containing polymerizable vinyl group, prepared by condensing (4:1 molar ratio) of 4-vinylpyridine with Nickel chloride, then polymerized with methyl methacrylate at 70 °C using AIBN as initiator. Metal complexand polymer metal complex have been characterized by elemental analyses, molar conductance, IR, 1H-NMR , Massspectra and thermal analyses (DTA and TGA). Conductivity measurement reveals the nonelectrolytic nature of thecomplex. This confirms that, the anion is coordinated to the metal ion. The IR reveal the metal ion is coordinated via thenitrogen atom of 4-VP. Nickel complex and polymer nickel complex have been tested invitro against number of tumor andnumber of microorganisms in order to assess their anti tumor and antimicrobial properties. The antimicrobial activity wasobserved by compounds VP-Ni and MMA-VP-Ni under the screening conditions. The activity against HCT-116 cells wasdetected for compound VP-Ni (with IC50 value 9.8±0.6 µg/ml), compared with reference standard (24.6±0.3 µg/ml) followedby MMA-VP-Ni (48.3±1.5). In conclusion, this study highlighted the synthesis of polymer nickel complex, and proved thepromising biological activity of the synthesized compounds

Improvement growth and immune status using a potential probiotic bacteria Micrococcus species among Culured Oreochromis niloticus

ABSTRACT Probiotic bacteria Micrococcus species isolated from the gonads of apparently healthy Oreochromis niloticus was harmless to O. niloticus and had antagonistic effect against the pathogenic Aeromonas hydrophila invitro. The inhibition zone to A. hydrohpila was 47 mm in diameter due to M. species. The effect of supplemental dietary probiotic bacteria (pseudomonas sp.10 7 cells/g food) on some heamatological parameter, growth performance and survival rate of O. niloticus. were divided to two groups, with three replicates each. Fish were fed frequently on a diet (5% of body weight) three times daily for 60 days. The obtained results showed that the final weight, weight gain, specific growth rate and protein efficiency ratio of O. niloticus increased significantly in the treated fish, when compared to the untreated group. Also, feed conversion ratio was lower in the treated group than the control one. Erythrocytic counts and hemoglobin content total serum protein, A/G ratio and phagocytic activity in fish fed on diets containing M. species were higher than that of the control group. After feeding sixty days O. niloticus was challenged I/P by A. hydrophila 0.3×10 7 cells/ml. The survival rate was 75% with M. species while, it was 20% in the control group. Thus, the isolated M. sp. was harmless to O. niloticus and had probiotic effect in vitro and in vivo

Autoxidation of 4-Hydrazinylquinolin-2(1H)-one; Synthesis of Pyridazino[4,3-c:5,6-c′]diquinoline-6,7(5H,8H)-diones

An efficient synthesis of a series of pyridazino[4,3-c:5,6-c′]diquinolines was achieved via the autoxidation of 4-hydrazinylquinolin-2(1H)-ones. IR, NMR (1H and 13C), mass spectral data, and elemental analysis were used to fit and elucidate the structures of the newly synthesized compounds. X-ray structure analysis and theoretical calculations unequivocally proved the formation of the structure. The possible mechanism for the reaction is also discussed

Autoxidation of 4-Hydrazinylquinolin-2(1H)-one; Synthesis of Pyridazino[4,3-c:5,6-c′]diquinoline-6,7(5H,8H)-diones

An efficient synthesis of a series of pyridazino[4,3-c:5,6-c′]diquinolines was achieved via the autoxidation of 4-hydrazinylquinolin-2(1H)-ones. IR, NMR (1H and 13C), mass spectral data, and elemental analysis were used to fit and elucidate the structures of the newly synthesized compounds. X-ray structure analysis and theoretical calculations unequivocally proved the formation of the structure. The possible mechanism for the reaction is also discussed

Autoxidation of 4-Hydrazinylquinolin-2(1H)-one; Synthesis of Pyridazino[4,3-c : 5,6-c ']diquinoline-6,7(5H,8H)-diones

An efficient synthesis of a series of pyridazino[4,3-c:5,6-c']diquinolines was achieved via the autoxidation of 4-hydrazinylquinolin-2(1H)-ones. IR, NMR (H-1 and C-13), mass spectral data, and elemental analysis were used to fit and elucidate the structures of the newly synthesized compounds. X-ray structure analysis and theoretical calculations unequivocally proved the formation of the structure. The possible mechanism for the reaction is also discussed.Peer reviewe

Autoxidation of 4-Hydrazinylquinolin-2(1H)-one; Synthesis of Pyridazino[4,3-c:5,6-c′ ]diquinoline-6,7(5H,8H)-diones

An efficient synthesis of a series of pyridazino[4,3-c:5,6-c′]diquinolines was achieved via the autoxidation of 4-hydrazinylquinolin-2(1H)-ones. IR, NMR ($^1$H and $^13$C), mass spectral data, and elemental analysis were used to fit and elucidate the structures of the newly synthesized compounds. X-ray structure analysis and theoretical calculations unequivocally proved the formation of the structure. The possible mechanism for the reaction is also discussed