Economic comparison of tillage and planting operations in three tillage systems

 To study the economy of tillage operations and present suitable systems for land preparation and planting, costs of execution of three different tillage operations in irrigated wheat crop were compared for three successive years.  The three systems include: conventional or maximum tillage (Max-till), reduced tillage (Red-till) using multitask machine, and using direct planting machinery to represent the no-tillage case (No-till).  Costs were composed of rental cost of tractor, the used implements, multitask machine and direct planting machine.  For each case, data were compared and analyzed in randomized block design.  The variance of wheat yield in the three tillage systems was significant at the 1% level.  Total costs per hectare were 109 and 78 and 46 Dollars for Max-till, Red-till and the No-till case, respectively.  Since, the test area under cultivation was part of a 200 hectare farm, crop protection and harvesting operations were carried out alike in the whole farm.  Accordingly, operations costs were estimated as 445 Dollars ha-1 tare.  Average yields of 7.85, 7.68, 5.2 t ha-1 were obtained, respectively, for Max-till, Red-till and No-till systems.  Since, the price per kg of wheat was equal to 0.36 Dollars ha-1, the profits of the harvest was equal to 2,271 Dollars ha-1 for the Max-till, 2,242 Dollars ha-1 for Red-till and 1,384 Dollars ha-1 for the No-till system.  In tillage and planting operations, usage of the reduce tillage system is offered as an alternative to the conventional tillage and no-till systems.  The Red-till system reduces fuel consumption, operation time, soil compaction due to decrease in the number of tractor trips, which leads to reduced production costs.  In addition, less investment in purchasing implements and preparation of the soil, which breaks the soil cohesion, are achieved with the reduced tillage system.   Keywords: costs of production, field performance, Max-till, Multitask machine, no-till, red-till, soil compaction

TEACH Pilot Study: Implementation of an e-Learning Course in Physical Activity and Sedentary Behaviour for Pre- and In-Service Early Childhood Educators (ECEs)

Early childhood educators (ECEs) are highly influential in promoting healthy movement behaviours (e.g. physical activity [PA] and sedentary behaviour [SB]) in early childhood. It is essential that ECEs gain knowledge and confidence in their ability to incorporate appropriate amounts of high-quality movement experiences for children in their care. However, ECEs do not currently receive related education in their current pre-service programs or professional development in practice. The Training EArly CHildhood educators in physical activity (TEACH) study intends to improve ECEs’ knowledge, confidence, and intentions regarding promoting healthy movement behaviours by providing comprehensive training in PA, SB, outdoor and risky play in childcare settings via an e-Learning course. The TEACH pilot study tests the implementation (e.g., fidelity, feasibility, acceptability, etc.) of an e-Learning course in PA and SB in a sample of Canadian pre-service (i.e., post-secondary students) and in-service (i.e., practicing) ECEs. The 4-module e-learning course was developed via a Delphi process and was completed by 32 pre-service and 121 in-service ECEs. Implementation outcomes were measured cross-sectionally at post-intervention via a process evaluation survey (baseline & follow-up) interviews (transcribed & sorted to implementation outcomes) and e-Learning course metrics (dose delivered, fidelity, complexity & feasibility) Participants reported that the course was highly acceptable, compatible, effective, feasible, and appropriate in complexity; however, some ECEs experienced technical difficulties with the e-Learning platform and noted a longer than anticipated course duration. The findings demonstrate the value of e-Learning for professional development interventions for ECEs. Participant feedback will be used to improve the scalability of this training

Changes in biochemical and physiological responses of common carp, Cyprinus carpio L. after long-term exposure to Pb (II)

In this study, the chronic toxic effects of Pb (II) on common carp, Cyprius carpio were investigated using several biomarkers at different levels of biological functions for assessing changes in ecosystem quality. In a bioassay,common carp juveniles were individually exposed to different dose of heavy metal, Pb II (0, 0.45, 0.89, 1.34 mg.l-1) for 28 days. Morphological indices such as hepatosomatic index, condition factor and lipid peroxidation (LPO) level and also the activities of superoxide dismutase (SOD) and catalase (CAT) were measured. These results indicated that there was significant lower condition factor in fish exposed to the highest concentration of Pb (p<0.05). The activity of hepatic antioxidant enzymes (SOD & CAT) and LPO level was significantly elevated after long-term exposure to higher concentration of Pb (p<0.05). Briefly, our findings suggested that common carp exposed to lead, develop oxidative stress, hence long-term exposure to higher concentrations of Pb could seriously affect the health status of fish

A compound current limiter and circuit breaker

© 2019 by the authors. Licensee MDPI, Basel, Switzerland. The protection of sensitive loads against voltage drop is a concern for the power system. A fast fault current limiter and circuit breaker can be a solution for rapid voltage recovery of sensitive loads. This paper proposes a compound type of current limiter and circuit breaker (CLCB) which can limit fault current and fast break to adjust voltage sags at the protected buses. In addition, it can act as a circuit breaker to open the faulty line. The proposed CLCB is based on a series L-C resonance, which contains a resonant transformer and a series capacitor bank. Moreover, the CLCB includes two anti-parallel power electronic switches (a diode and an IGBT) connected in series with bus couplers. In order to perform an analysis of CLCB performance, the proposed structure was simulated using MATLAB. In addition, an experimental prototype was built, tested, and the experimental results were reported. Comparisons show that experimental results were in fair agreement with the simulation results and confirm CLCB’s ability to act as a fault current limiter and a circuit breaker

Vibration analysis of a small diesel engine using diesel-biodiesel fuel blends

Biodiesel as an environmentally friendly fuel has the potential to provide comparable engine performance results.  Biodiesel is a renewable fuel produced from vegetable and seed oils, animal fats or waste edible oils.  Sound and vibration caused by the combustion process in the engine might have direct effects on users.   One of the important characteristics of diesel fuels is high noise and vibration.  The present study was carried out to examine the vibration of different diesel-biodiesel fuel blends in power tiller engine.  The main goal was to present fuels with the minimum vibration.  So, the time domain signals were analyzed in five levels of engine speed, three axes and six fuel blends on the engine.  The signal processing and statistical approach were applied for data analysis.  The results showed that in all engine speeds, the dominant frequency is matched to the piston stroke frequency of the engine, as well as the frequency of vibration with the increase of engine speed.  The experiments indicated that the magnitude of vibration in the power tiller engine depends on the axis of measurement, engine speed and the fuel blends.  Vibration acceleration is significantly affected by engine speed and the increase in forward speed due to the increase in vibration acceleration rms.  The results of the experiments revealed that vibration acceleration is significantly affected by the axis of measurement.  The magnitude of vibration acceleration in vertical axis was more than that in the other two axes and magnitude of vibration acceleration in the longitudinal axis was more than that in the lateral axis.  Fuel blends had significant effect on the vibration.  It demonstrated that B100, B5 and B20 have the lowest vibration.  On the contrary, B15 and B10 have the highest vibration.   Keywords: vibration analysis, power tiller, time domain, frequency domain, diesel-biodiesel fuel blend

Supervised and non-supervised AE data classification of nanomodified CFRP during DCB tests

Aim of the paper is to use acoustic emissions to study the effect of electrospun nylon 6,6 Nanofibrous mat on carbon-epoxy composites during Double Cantilever beam (DCB) tests. In order to recognize the effect of the nanofibres and to detect different damage mechanisms, k-means clustering of acoustic emission signals applied to rise time, count, energy, duration and amplitude of the events is used. Supervised neural network (NN) is then applied to verify clustered signals. Results showed that clustered acoustic emission signals are a reliable tool to detect different damage mechanisms; neural network showed the method has a 99% of accuracy

A multi-inductor h bridge fault current limiter

© 2019 by the authors. Current power systems will suffer from increasing pressure as a result of an upsurge in demand and will experience an ever-growing penetration of distributed power generation, which are factors that will contribute to a higher of incidence fault current levels. Fault current limiters (FCLs) are key power electronic devices. They are able to limit the prospective fault current without completely disconnecting in cases in which a fault occurs, for instance, in a power transmission grid. This paper proposes a new type of FCL capable of fault current limiting in two steps. In this way, the FCLs’ power electronic switches experience significantly less stress and their overall performance will significantly increase. The proposed device is essentially a controllable H bridge type fault current limiter (HBFCL) that is comprised of two variable inductances, which operate to reduce current of main switch in the first stage of current limiting. In the next step, the main switch can limit the fault current while it becomes open. Simulation studies are carried out using MATLAB and its prototype setup is built and tested. The comparison of experimental and simulation results indicates that the proposed HBFCL is a promising solution to address protection issues

Risk measurement in the global supply chain using monte-carlo simulation

Abstract Nowadays, logistics and supply chain management (SCM) is critical to compete in the current turbulent markets. In addition, in the global context, there are many uncertainties which affect on the market. One of the most important risks is supplier disruption. The first step to cope with these uncertainties is quantifying them. In this regard many researches have focused on the problem but measurement of the risk in the global SCM is yet a challenge. In the uncertain conditions, simulation is a good tool to study the system. This paper aims to study a global supply chain with related risks and measurement of the risks using simulation. Global aspects considered in the paper are: 1-currency exchange rate, 2-extended leadtime for abroad supplies, 3-regional and local uncertainties. In this regard, two popular risk measurement approaches (VaR and CVaR) are used in the simulation of uncertainties in the global supply chain. Results showed that adopting risk averse behavior to cope with the uncertainties leads to the lower stockouts and also higher costs

CFD Study of the Impacts of a Turbocharger’s Various Wastegate and Bypass Configurations on the Efficiency and the Flow Field of its Radial Turbine

Turbocharger systems enhance the engine power and efficiency, reduce its pollution, and downsize the engine volume. As the significance of exploiting turbochargers in gasoline engines is surging among automobile manufacturers, the necessity of improvement in the system components becomes more critical. This paper investigates the impacts of a turbocharger turbine bypass and wastegate geometry alterations on the performance and the flow field characteristics via numerical simulations. The numerical method verification and mesh independence study are performed for the original geometry. The simulation results of the altered geometries indicate that better alignment between the bypassed and the bulk flows leads to higher efficiency of the turbocharging system. In addition, the bent or elbow-shaped and protruded turbine walls immediately downstream of the wheel are found to be unfavorable. It is also uncovered that if the wastegate shape and the housing walls are designed in such a way that the effects of ensuing vortices are minimized, it improves the stage efficiency, which is desirable for two-stage turbochargers. Furthermore, a novel manufacturable design is proposed in this study, which increases the efficiency and useful power by 19.9% and 6.7%, respectively

How native state topology affects the folding of Dihydrofolate Reductase and Interleukin-1beta

The overall structure of the transition state and intermediate ensembles experimentally observed for Dihydrofolate Reductase and Interleukin-1beta can be obtained utilizing simplified models which have almost no energetic frustration. The predictive power of these models suggest that, even for these very large proteins with completely different folding mechanisms and functions, real protein sequences are sufficiently well designed and much of the structural heterogeneity observed in the intermediates and the transition state ensembles is determined by topological effects.Comment: Proc. Natl. Acad. Sci. USA, in press (11 pages, 4 color PS figures) Higher resolution PS files can be found at http://www-physics.ucsd.edu/~cecilia/pub_list.htm