Design and Simulation of a Vision-Based Automatic Trout Fish-Processing Robot

Today, industrial automation is being applied in a wide range of fields. The initial modeling of robots and mechanical systems together with simulation results in optimal systems. In this study, the designed system is simulated to obtain the required velocities, accelerations and torques of the actuating arms in a vision-based automatic system. Due to the slippery skin of fish and the low friction coefficient, it is not easy to design an optimal tool to handle fish. Since the fish-processing operation is undertaken step by step and provides fish stability, it is essential that the gripper enables different processing operations along the system. The proposed system performs belly-cutting, beheading, gutting, and cleaning stages for different fish sizes, based on the extracted dimensions of the vision system. In the head-cutting section, the average speed of the actuator jack was considered as 500 mm s−1. Under these conditions, the maximum required force to provide this speed was 332.45 N. In the belly-cutting subsystem, the required torque for the stepper motor resulted in 1.79-2.15 N m. Finally, the maximum required torque for the gutting stepper motor was calculated as 0.69 N m in the tested processing capacitie

Occupational Exposure to Blood and other Bodily Fluids among Laboratory Technicians: An Underestimated Risk Factor

Background: The aim of this study was to evaluate risk of Needle stick and Sharp Injuries (NSI) and exposure to blood borne pathogens, among laboratory technicians.Methods: 213 self-reporting questionnaires were distributed among the laboratory technicians who were working at three educational hospitals in Tehran. A total of 193 laboratory personnel completed the questionnaire. Results: 69.9% of participants were females. 94 (43.5%) of participants had a history of needle stick injury and 70 (36.3%) had splash injury during their work life. The prevalence of one year (last year) exposure was 25.4% and 17.1% respectively. In 58 out of 94 cases, recapping was the mechanism of injury. 151 laboratory personnel (78.2%) had been immunized against Hepatitis B Virus (HBV). 79.8% of the laboratory personnel usually eat, drink or smoke at workplace. 175 (91%) of the study sample used personal protective equipment such as glove in laboratory environment. Conclusions: In this study, a high frequency of NSI and splash were observed among laboratory technicians in the research context, which was not related to some variables such as age, sex, duration of employment, the HBV vaccination status, participating in workshop of education and training for injury prevention

Occupational Exposure to Blood and other Bodily Fluids among Laboratory Technicians: An Underestimated Risk Factor

Background: The aim of this study was to evaluate risk of Needle stick and Sharp Injuries (NSI) and exposure to blood borne pathogens, among laboratory technicians.Methods: 213 self-reporting questionnaires were distributed among the laboratory technicians who were working at three educational hospitals in Tehran. A total of 193 laboratory personnel completed the questionnaire. Results: 69.9% of participants were females. 94 (43.5%) of participants had a history of needle stick injury and 70 (36.3%) had splash injury during their work life. The prevalence of one year (last year) exposure was 25.4% and 17.1% respectively. In 58 out of 94 cases, recapping was the mechanism of injury. 151 laboratory personnel (78.2%) had been immunized against Hepatitis B Virus (HBV). 79.8% of the laboratory personnel usually eat, drink or smoke at workplace. 175 (91%) of the study sample used personal protective equipment such as glove in laboratory environment. Conclusions: In this study, a high frequency of NSI and splash were observed among laboratory technicians in the research context, which was not related to some variables such as age, sex, duration of employment, the HBV vaccination status, participating in workshop of education and training for injury prevention

High Diversity of Genes for Nonhost Resistance of Barley to Heterologous Rust Fungi

Inheritance studies on the nonhost resistance of plants would normally require interspecific crosses that suffer from sterility and abnormal segregation. Therefore, we developed the barley–Puccinia rust model system to study, using forward genetics, the specificity, number, and diversity of genes involved in nonhost resistance. We developed two mapping populations by crossing the line SusPtrit, with exceptional susceptibility to heterologous rust species, with the immune barley cultivars Vada and Cebada Capa. These two mapping populations along with the Oregon Wolfe Barley population, which showed unexpected segregation for resistance to heterologous rusts, were phenotyped with four heterologous rust fungal species. Positions of QTL conferring nonhost resistance in the three mapping populations were compared using an integrated consensus map. The results confirmed that nonhost resistance in barley to heterologous rust species is controlled by QTL with different and overlapping specificities and by an occasional contribution of an R-gene for hypersensitivity. In each population, different sets of loci were implicated in resistance. Few genes were common between the populations, suggesting a high diversity of genes conferring nonhost resistance to heterologous pathogens. These loci were significantly associated with QTL for partial resistance to the pathogen Puccinia hordei and with defense-related genes

Development and performance simulation of a novel helical manure distributer machine

Organic manures play an important role in improvement of soil fertility, increase of crop yield and quality. Among these, the use of advantages of manures depends on method of spreading. Unsuitable method in spreading manure caused decreased crop production. Therefore in this study, a novel helical manure distributer machine was developed that capable to speared manure with maximum distribution width at different moisture of manure. The machine performance was modeled as well. This machine consisted of two screw conveyors (auger) on the bottom of hopper, grips, two drums, meshing plate and other component. Effect of speed of drum and mass of particle of manure on distribution width were considered. The power requirement of auger was calculated in different rotational speed of auger and three level of manure-manure friction. Drawbar power of machine was evaluated as well. The results showed that maximum distribution width was 14 m for mass of manure. Tractor speed was 5-10 km/hr. and consumed manure rate of 20-60 ton/ha. Volume of hopper was designed 6m3. The maximum value of PTO power requirement and drawbar power obtained was 7.7 hp and 11.45hp respectively

Elicitor-induced in vitro shoot multiplication and steviol glycosides production in Stevia rebaudiana

Stevia rebaudiana, which produces the non-caloric natural sweeteners referred to as steviol glycosides (SGs), is a perennial herb native to South America. This study examines the effect of various biotic elicitors, including chitosan (CH) and yeast extract (YE), as well one abiotic elicitor, namely methyl jasmonate (MeJA), on in vitro shoot multiplication and the SGs content of S. rebaudiana. Different concentrations of these elicitors (50, 100, 200, and 300 mg/L) were added to Murashige and Skoog medium that had been supplemented with 2 mg/L 6-benzylaminopurine (BAP). The results showed that both biotic and abiotic elicitors increase shoot multiplication significantly when compared to the basal medium alone. Shoot length and shoot number increased by 70% and 94%, respectively, after adding 200 mg/L CH. Dry weight increased by 51%, 47%, and 36% after adding YE 50, CH 200, and MeJA 100 mg/L, respectively. Interestingly, total SGs content increased with the addition of MeJA 100, CH 200, and YE 50 (by 60%, 44%, and 40%, respectively). Stevioside (ST) and rebaudioside A (Reb A) concentrations, which are the final products of the SGs pathway, were both augmented by the addition of MeJA 100 and CH 200 mg/L. Moreover, these elicitors significantly enhanced the Reb A/ST ratio. Overall, the results indicate that elicitors? CH 200, MeJA 100, and YE 50 mg/L, in particular? can be effective stimulants for the production of biomass and the chemical composition of SGs content of in vitro S. rebaudiana. ? 2020 SAAB. Published by Elsevier B.V. All rights reserved

The Effect of Teaching Uning a Blend of Collaborative and Mastery of Learning Models, on Learning of Vital Signs: An Experiment onNursing and Operation Room Students of Mashhad University of Medical Sciences

Introduction: Educational system is a set of plans, approaches, and materials which coordinately facilitate learners’ access to pedagogical objectives. With regard to the fact that each step of knowledge acquisition calls for a particular learning method or a specific approach, it might be possible to ease students’ achievement of learning objectives by using a blend of learning strategies. This study aimed to determine the effects of blended teaching models on learning of vital signs among nursing and operation room students. Methods: This was a quasi-experimental, with before and after-research design performed on two groups. All first semester nursing and operation room students (N=52) were selected for the study. They were randomly allocated into two groups of experiment and control and were instructed using blended and traditional education methods. Before and after each session of education, academic achievement tests were applied to evaluate students’ cognitive learning in three levels of knowledge, comprehension, and application regarding the topic of vital signs. Data was analyzed using t-test, Wilcoxon, Mann Whitney, and Fisher’s exact test. Results: Both teaching methods improved students’ learning in knowledge, comprehension, and application levels. Mean differences before and after education in both groups were statistically significant in all levels. The mean of increase in scores in all exams and sessions were significantly higher in the blended teaching group compared to the traditional one. The mean score of students’ satisfaction in experiment group(66.2±19.5) was significantly (p<.001) different from the control(38.9±21.4). Conclusion: The used blend of teaching methods was more effective than the traditional one, on the improvement of knowledge, comprehension and application of vital signs topic. It also satisfied students more. Of course, the traditional method was also effective, so both approaches may be used according to the situation

Numerical Investigation of Water Entry Problem of Pounders with Different Geometric Shapes and Drop Heights for Dynamic Compaction of the Seabed

The water entry problem of three-dimensional pounders with different geometric shapes of cube, cylinder, sphere, pyramid, and cone was numerically simulated by the commercial software Abaqus, and the effects of pounder shape and drop height from the free surface of water on deepwater displacement and velocity as well as pinch-off time and depth were investigated. An explicit dynamic analysis method was employed to model fluid-structure interactions using a Coupled Eulerian-Lagrangian (CEL) formulation. The simulation results are verified by showing the computed shape of the air cavity, displacement of sphere, pinch-off time, and depth which all agreed with the experimental results. The results reveal that the drag force of water has the highest and lowest effect on cubical and conical pounders, respectively. Increasing the pounder drop height up to the critical height leads to increased pounder velocity while impacting the model bed and more than the critical drop height has a reverse effect on pounder impact velocity. Pinch-off time is a very weak function of pounder impact velocity; but pinch-off depth increases linearly with increased impact velocity

Numerical study of seismic response of trapezoidal alluvial valleys against vertically propagating incident waves

The experience of previous earthquakes in the world shows that the structural damage due to the earthquakes is highly influenced by the site condition, which is known as site effects. Since most cities are built on alluviums, studying the seismic response of alluvial basin, which are the site of many structures, is very important. This study investigates the seismic response of 2D trapezoidal alluvial valleys with slope angles of 31, 45, and 71.5, against P and SV vertically propagating incident waves in middle and lateral areas of the valleys. Then the effect of changes in Poisson's ratio and specific weight of alluvial materials on the seismic response of the valley in the mentioned areas is investigated. Numerical modeling is done using QUAKE/W finite element software, based on the equivalent linear analysis. According to the results, by increasing the slope angle of the valley, the vertical acceleration and displacement response spectrum in the middle and lateral areas of the alluvial valley decrease and increase, respectively. Moreover, by increasing the Poisson's ratio and specific weight of alluvial materials, the vertical acceleration and displacement response spectrum in the middle area of the valley decrease, but do not undergo tangible changes in the lateral areas of the valley