Strain analysis at flat surfaces of loaded members using digital image correlation technique

This research examines the applicability of the planned Digital Image Correlation (DIC) system to measure the strains in tensile experiments. DIC is a low-cost optical technique, and is an appropriate measurement used to measure surface displacement, strain and stress map distribution without any contact with the tested surfaces. In the present research, the tensile test is conducted on two different flat samples, which are painted in a speckle pattern on the tested surface to use DIC features in stain measurements. To guarantee the efficiency of the planned DIC system, the DIC code has been built using MATLAB programming language. The obtained results from DIC technique is compared with the results from open-source software (Ncorr), the finite element analysis (ANSYS) as well as the exact and analytical solutions. The comparison results showed that there was A quite acceptable and agreement achieved between them. According to the exact solution, The percentage of accuracy of the obtained results for the Aluminum without hole plate was around (89-93) % whereas the accuracy with the NCORR was about 96 %. For the second copper plate with a central hole, the accuracy has been obtained to be (80.7-99) % with the analytical solution wherein its value has reached (81-97) % with Ncorr software

New State Observer Based On Takai-Sugeno Fuzzy Controller of Induction Motor

International audienceThis paper presents a nonlinear observer-based on Takagi-Sugeno (T-S)fuzzy controller design approach for induction motor (IM). The peculiarity of this paper is the synthesis of a mono-Luenberger observer for highly coupled system. The TS fuzzy model is firstly used to approximate the nonlinear IM systems. Next, based on the differential mean value theorem combined to the sector nonlinearity transformation , a nonlinear fuzzy observer is designed to estimate the system states in order to implement the fuzzy controller. Then, the parallel distributed compensator (PDC) scheme is used to design the fuzzy controller for the overall system. Fuzzy Controller and observer gains are obtained by solving a set of Linear Matrix Inequality (LMI).Finally, illustrative simulation results represented to validate the performance of the proposed approach

Seasonal variations of sexual activity of local bucks in western Algeria

The aim of the present study was to evaluate the seasonal variation of sexual activity among bucks of local breed (Arbia) in western Algeria. The experiment was carried out using eight bucks aged between 4 and 6 years, a group of males in their pre-puberty age (4 to 6 months) and two females. Animals were kept in a building during one year and fed with a constant ration of wheat and hay with free access to water. Sexual activity was evaluated by scrotal circumference and sexual behaviour analysis. Results showed that the monthly average of scrotal circumference was high during August and September (27.58 ± 0.16 and 27.67 ± 0.17 cm, respectively) and low during April and May (25.18 ± 0.11 and 25.25 ±0.17 cm, respectively). Monthly averages of sexual behaviour followed similar evolution. When the season of the year is considered, sexual behaviour and scrotal circumference presented significant variations. The two parameters are maximal during autumn (7.96 ± 1.28 and 26.89 ± 0.55 cm, respectively) and go down during winter (6.09 ± 1.25 and 25.65 ± 0.27 cm, respectively) to reach minimal values during spring (4.89 ± 1.66 and 25.41 ± 0.37 cm, respectively) then they go up during summer. Inconclusion, bucks of local breed in western Algeria have seasonal variations of sexual activity in relation to annual photoperiod variation; short days stimulate the sexual activity whereas long days inhibit it

Effect of organic extracts of Bunium incrassatum on the hematological, ovarian and uterine parameters of mature female rabbit

This work aims to evaluate the effect of the organic extracts of Bunium incrassatum roots on some hematological parameters and histological changes of the genital tract. The study was achieved on mature rabbits of the local breed for 15 days. The animals were divided into five groups, which have daily administered 0, 25, 50, 100 and 200 mg/kg/day doses, respectively. The group with dose 0 was taken as a control. After treatment, the rabbits were sacrificed. The rabbit blood was collected in heparin tubes and their ovaries and uterus were removed, fixed in 10 % formalin; and stained with hematoxylin-eosin. The treatment induces a significant decrease in the level of Triglyceride, Cholesterol and a significant increase in the number of growing follicles accompanied by a decrease in atretic follicles, compared to the control group. The study shows that the organic extract of B. Incrassatum has estrogenic effects.Keywords: Bunium incrassatum, Organic extract, Rabbits, Ovaries, Follicles, Liver, Uteru

Study of seasonal sexual activity variations in Algerian rams: Sexual behaviour, testosterone concentration control and environmental factors

This study focuses on the determination of seasonal effect on two main andrological sexual activity parameters within young and adults rams of Rembi breed from Algeria for a period of one year. The experiment involved a weekly evaluation of males’ sexual behaviour and a monthly measurement of serum testosterone concentration in order to know the main testicular endocrine activity. The purpose of this experiment was to assess better the characteristics of the reproductive activity between two categories of rams age-wise and to define the variations and interactions between the two parameters during each season. Data shows no statistically significant effect of age on the testosterone concentration but showed a highly significant difference between age groups in terms of sexual behaviour. Seasonal variations of the studied parameters were statistically significant in both ram ages with higher values during spring and autumn and lower values during summer and winter.Keywords: Rembi, ram, testosterone, sexual activity, season, age.African Journal of Biotechnology Vol. 12(41), pp. 6042-604

Radiation Hardness Tests Of Piezoelectric Actuators With Fast Neutrons At Liquid Helium Temperature

Piezoelectric actuators, which are integrated into the cold tuning system and used to compensate the small mechanical deformations of the cavity wall induced by Lorentz forces due to the high electromagnetic surface field, may be located in the radiation environment during particle accelerator operation. In order to provide for a reliable operation of the accelerator, the performance and life time of piezoelectric actuators (~24.000 units for ILC) should not show any significant degradation for long periods (i.e. machine life duration: ~20 years), even when subjected to intense radiation (i.e. gamma rays and fast neutrons). An experimental program, aimed at investigating the effect of fast neutrons radiation on the characteristics of piezoelectric actuators at liquid helium temperature (i.e. T~4.2 K), was proposed for the working package WP#8 devoted to tuners development in the frame of CARE project. A neutrons irradiation facility, already installed at the CERI cyclotron located at Orléans (France), was upgraded and adapted for actuators irradiations tests purpose. A deuterons beam (maximum energy and beam current: 25 MeV and 35µA) collides with a thin (thickness: 3 mm) beryllium target producing a high neutrons flux with low gamma dose (~20%): a neutrons fluence of more than 1014 n/cm2 is achieved in ~20 hours of exposure. A dedicated cryostat was developed at IPN Orsay and used previously for radiation hardness test of calibrated cryogenic thermometers and pressure transducers used in LHC superconducting magnets. This cryostat could be operated either with liquid helium or liquid argon. This irradiation facility was upgraded for allowing fast turn-over of experiments and a dedicated experimental set-up was designed, fabricated, installed at CERI and successfully operated for radiation hardness tests of several piezoelectric actuators at T~4.2 K. This new apparatus allows on-line automatic measurements of actuators characteristics and the cryogenic parameters. Further, the test-cell and actuators are equipped with high purity Ni foils for measuring the total neutrons dose by an activation method. In this report, the details of the irradiation test facility will be described then the experimental data will be analyzed and discussed

Electromechanical, Thermal Properties And Radiation Hardness Tests Of Piezoelectric Actuators At Low Temperature

IPN Orsay participates, in the frame of the CARE project activities supported by EU, to the development of a fast cold tuning system for SRF cavities. The main task of IPN is the full characterization of piezoelectric actuators at low temperature T, and the study of their behaviour when subjected to fast neutrons radiation at T=4.2 K. In order to compare the performance of various industrial piezoelectric actuators, a new apparatus was developed and successfully used for measuring their electromechanical and thermal properties for T in the range 1.8 K-300 K. Different parameters were investigated as function of T: piezoelectric constant, dielectric and thermal properties including heating ΔT due to dielectric losses vs. modulating voltage Vmod and frequency f. We observed a decrease of the maximum displacement ΔX of the actuators tested from ΔX ~40μm @ 300K down to 1.8μm-3.5 μm @ 1.8K, depending on both material and fabrication process of the piezostacks. Besides, both material and fabrication process have a strong influence on the shape of the characteristics ΔX vs. T dependence. Finally a dedicated facility located at CERI institute (Orléans, France) for radiation hardness tests of actuators with fast neutrons at T=4.2 K was developed and the first beam tests results are summarized

Seasonal variation of plasma testosterone levels in Algerian male Arabia goats

The aim of the present work was to evaluate the general monthly averages of the testosterone hormone and the influence of  season and photoperiod on plasma testosterone levels in Arabia bucks of Algeria. Testosterone concentrations were determined throughout one year in blood samples collected every fortnight of the month from nine males of Arabia goat breeds, fed a constant diet, maintained without interactions with female goat. Plasma testosterone level was measured by radioimmunoassay. Analyses performed show that the monthly averages of the testosterone hormone vary during the year; higher levels were recorded during August (T=8.57±6.72, P=0.00***) however, bucks displayed the same change tendency during the same period (P=0.79). Plasma testosterone concentrations vary significantly between seasons (P=0.00***) being higher during autumn (6.15±3.81ng/ml) compared with spring (0.90 ± 1.27ng/ml) when hormone synthesis reaches its lowest levels. In conclusion, Arabia bucks of Algeria displayed a clear seasonality of plasma testosterone concentration with very low levels in winter and spring (from January to May) and high levels in summer and autumn (from July to November).Keywords: Arabia bucks, testosterone, season, photoperiod

Modelling data of an urban drainage design using a Geographic Information System (GIS)database

This paper describes the development of a model to interface a planned urban drainage system with Geographic Information System (GIS)through the introduction of open-source tools; Auto Numbering and Get Elevation to extract essential data from GIS and Excel2GIS to bridge the output data between GIS and the drainage design program. Creating a range of essential data from digital database repositories aids the development of decision-support tools for urban planners in a simulation of different urban drainage scheme scenarios and moderates the interference with other infrastructure utilities. These tools, modelled with design software and GIS platform, are tested in two case studies; the results revealing essential improvements in accuracy of output, time taken to prepare and run the model and model presentation which visualised the hydraulic design results and global location of the drainage layout on an urban master plan. © 2019 Elsevier B.V