187 research outputs found

    POSITION TRACKING CONTROL OF DC MOTOR FOR FRONT WHEEL SYSTEMS VIA HILS SIMULATION METHOD

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    This paper present about position tracking control of DC motor to be used as the actuator controller for the front wheel test rig system. The controller strategy that was developed is based on Proportional-Integral-Derivative (PID) controller. It consists of one single closed control loops namely position tracking control loop.  To evaluate the effectiveness of the proposed controller, simulation and experimental studies were performed by using various input demand such as saw tooth, sine and step functions in 5°, 10°, 15° and 20° with the present of steering ratio at 360:20. The results, it is found that the trend between simulation and experimental data are similar with the command position with acceptable level of error which less than 10% for application at hand

    Progressive collapse resistance of post-fire cellular beam-column substructures with various web-opening shapes

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    The sudden column loss, which is caused by fire, is a unique illustration of a localized failure that can eventually lead to the progressive collapse of the entire steel-framed structures. To avoid high costs, as well as risks of testing progressive collapse under fire conditions, numerical simulation, which utilizes the finite element (FE) software, is essential to investigate the fire exposure influence on steel-framed structures. In this study, FE simulations using ABAQUS-Explicit are used to examine the resistance of the progressive collapse of beam-column substructures with a cellular opening in the web under fire or post-fire conditions. The FE models' accuracy and reliability are accordingly enhanced and validated by comparing the results with previous experimental test results. Twenty different types of cellular beams with differently sized (i.e., D = 75, 90, and 105 mm) and shaped web openings (i.e., circular, square, and hexagon holes) are numerically investigated. The failure mechanism, load–displacement behavior, and collapse mechanisms are assessed as well. The results showed that the load-carrying capacity and associated displacement are significantly reduced for fire-exposed specimens. The flexural action and catenary action mechanism resistances of the fire-exposed specimens are all lower than those of the non-fire-exposed specimens, which established that the fire exposure condition might have worsened the initial stiffness and ultimate capacity of the specimens

    First principles study of mechanical, thermal, electronic, optical and superconducting properties of C40-type germanide-based MGe2 (M = V, Nb and Ta)

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    Non-centrosymmetric germanide-based superconductors have recently attracted particular attention because of their unconventional physical properties. In the present study, we comprehensively investigated the structural and hitherto unexplored electronic, optical, mechanical, thermal, and superconducting state properties of germanide-based superconductors, MGe2 (M = V, Nb, and Ta), using the density functional theory. The obtained lattice parameters and accordingly the volume of the unit cells agree very well with the earlier reported values, indicating the high reliability of the physical properties studied. All the compounds studied herein are dynamically and mechanically stable. The compounds are brittle (ranked: NbGe2 50% for all these compounds, demonstrating their potential for application as coating material to reduce heating from incident electromagnetic radiation. Based on the results obtained for thermal properties and comparison with benchmark system, Y4Al12O9 and some other predicted compounds, the titled compounds could also be used as thermal barrier coating materials. Some important parameters for the understanding of the superconducting behavior, such as the Coulomb pseudopotential, London penetration depth, coherence depth, Debye temperature, electron-phonon coupling constant, and Ginzburg-Landau parameter, are also estimated, and the results obtained support that the NbGe2and TaGe2 compounds should be categorized as a type-2 superconductors

    Exploring the cost-effectiveness of high versus low perioperative fraction of inspired oxygen in the prevention of surgical site infections among abdominal surgery patients in three low- and middle-income countries

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    Background: This study assessed the potential cost-effectiveness of high (80–100%) vs low (21–35%) fraction of inspired oxygen (FiO2) at preventing surgical site infections (SSIs) after abdominal surgery in Nigeria, India, and South Africa. Methods: Decision-analytic models were constructed using best available evidence sourced from unbundled data of an ongoing pilot trial assessing the effectiveness of high FiO2, published literature, and a cost survey in Nigeria, India, and South Africa. Effectiveness was measured as percentage of SSIs at 30 days after surgery, a healthcare perspective was adopted, and costs were reported in US dollars ().Results:HighFiO2maybecosteffective(cheaperandeffective).InNigeria,theaveragecostforhighFiO2was). Results: High FiO2 may be cost-effective (cheaper and effective). In Nigeria, the average cost for high FiO2 was 216 compared with 222forlowFiO2leadingtoa 222 for low FiO2 leading to a −6 (95% confidence interval [CI]: −13to 13 to −1) difference in costs. In India, the average cost for high FiO2 was 184comparedwith184 compared with 195 for low FiO2 leading to a −11(9511 (95% CI: −15 to −6)differenceincosts.InSouthAfrica,theaveragecostforhighFiO2was6) difference in costs. In South Africa, the average cost for high FiO2 was 1164 compared with 1257forlowFiO2leadingtoa 1257 for low FiO2 leading to a −93 (95% CI: −132to 132 to −65) difference in costs. The high FiO2 arm had few SSIs, 7.33% compared with 8.38% for low FiO2, leading to a −1.05 (95% CI: −1.14 to −0.90) percentage point reduction in SSIs. Conclusion: High FiO2 could be cost-effective at preventing SSIs in the three countries but further data from large clinical trials are required to confirm this

    Elective surgical services need to start planning for summer pressures.

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    SUITABILITY ASSESSMENT OF ORANGE FLESHED SWEETPOTATO VARIETIES AT NORTHERN REGION OF BANGLADESH

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    ABSTRACT The present experiment was conducted with four Bangladesh Agricultural Research Institute (BARI) released orange fleshed sweetpotato varieties and a local cultivar as check at Sadar Upazila of Gaibanda and Pirgachha Upazila of Rangpur district during 2019-20 cropping season for their suitability assessment. It was found that all yield and yield contributing characters varied significantly at both the locations. Due to higher adaptability in northern conditions, it was observed that the variety of BARI SP-12 produced the highest yield (39.63 ton/ha at Gaibandha and 30.02 t/ha at Rangpur) followed by BARI SP-8 (32.03 ton/ha at Gaibandha and 25.93 t/ha at Rangpur) while the lowest was recorded in BARI SP-15 (13.33 ton/ha at Gaibandha and 3.03 ton/ha at Rangpur). Considering locations, all the studied varieties performed better at Gaibandha than Rangpur district. The crop was evaluated at vegetative and harvesting stage at farmers’ field by the farmers, researchers and extension staffs. At harvesting stage evaluation results revealed that, BARI SP-8 ranked first at Gaibandha and BARI SP-12 at Rangpur while BARI SP-4 ranked (2nd) at both locations. During harvesting stage evaluation, participants preferred BARI SP-12 as at both locations followed by BARI SP-8 at Gaibandha and BARI SP-4 at Rangpur. Through organoleptic test BARI SP-4 and BARI SP-12 found good to excellent by the farmers, researchers and extension staffs. Keywords: Sweet potato, evaluation, organoleptic test

    Dynamic analysis of thick plates reinforced with agglomerated GNPs

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    In this work, the quasi-3D hyperbolic shear deformation theory (quasi-3D HSDT) is utilized to examine the dynamics of thick rectangular plates reinforced with rectangular nanofillers known as graphene nanoplatelets (GNPs). Agglomeration of the GNPs is incorporated and the mechanical characteristics like shear, elastic, and bulk moduli, Poisson's ratio, and density are analysed according to the mixture along with the Eshelby-Mori-Tanaka approach. Hamilton's principle is hired to derive the solving equations, the Navier approach is hired to present an analytical solution in the spatial domain, and the Newmark method is hired to provide an approximate solution in the time domain. The relevance of the dynamic response and the natural frequencies of the plate on several parameters are explored such as dispersion pattern and the GNPs percentage and agglomeration parameters. It is discovered that for a specific GNPs percentage, growth in the amount of agglomerated GNPs leads to lower natural frequencies and higher dynamic deflection. Meanwhile, for a specific mass fraction of the agglomerated GNPs, growth in the volume of clusters brings about higher natural frequencies and lower dynamic deflection

    Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries