LOWER EXTREMITY KINEMATICS OF SKI MOTION ON HILLS

This research study aimed to collect thre- dimensional joint angles of the lower extremity during a basic ski motion in order to provide more quantitative teaching guide-lines for ski instructors. Eleven infrared cameras were placed to cover the capture volume of three different stopping movements (e.g. “Pflug Fahren”) on hills. Six ski instructors participated in the test. Three trials of each stop were selected for comparison. Based on the results, skiers tended to use the edge of the ski and maintain a wider “V” shape at the shortest stop distance (e.g. 2m) compared to the other stops. Also, each skier had to invert the foot with a less flexed and more abducted knee and hip position as the stopping distance was decreased. This information will be useful for the development of more objective teaching guide-lines for beginner skiers

A numerical study on the maneuverability of the DTMB 5415 using CFD

Error on spine and title page. Date reads 2018. Date of award is 2019.The International Maritime Organization (IMO) has proposed various safety standards which ship engineers are required to follow. It is therefore necessary to consider a ship's safety during its initial design stages. The larger ships such as large cargo carriers require strict safety standards. With larger vessels such as these, the IMO safety standards stipulate the need for a vessel to demonstrate high maneuverability - this may be achieved with a twin-screw ship. Demand for twin-screw ships will therefore increase in near future. Thus, when it comes to the maneuverability of a twin-screw ship, the existing research leaves a lot to be desired as it primarily focuses on container ships. For these reasons, it is crucial that thorough research is performed on the maneuverability of other styles of twin-screw ships, such as naval combatants.Most studies on the manoeuvrability of twin-screw ships have focused on container ships as there is an abundance of existing data available for them. However, container ships tend to have less manoeuvring problems compared to other types of ships. Thus, when it comes to the manoeuvrability of a twin-screw ship, the existing research leaves a lot to be desired as it primarily focuses on container ships. For these reasons, it is crucial that thorough research is performed on the manoeuvrability of other types of twin-screw ships, such as naval combatants.The main goal of this research is to assess the manoeuvrability of the twin-screw naval combatant ship the DTMB 5415 using Computational Fluid Dynamics (CFD) and MATLAB.In this research, Star-CCM+ is used as a RANS solver to measure the hydrodynamic forces and moments on the twin-screw and derive the hydrodynamic derivatives. To validate the simulated results, a comparison is made against the existing experimental data from the published literature. Following this, MATLAB will be used to predict the manoeuvrability of the vessel in question such as its turning ability and course changing ability. A Mathematical Modelling Group (MMG) model is then used to predict the individual hydrodynamic forcesof the propeller and hull.The International Maritime Organization (IMO) has proposed various safety standards which ship engineers are required to follow. It is therefore necessary to consider a ship's safety during its initial design stages. The larger ships such as large cargo carriers require strict safety standards. With larger vessels such as these, the IMO safety standards stipulate the need for a vessel to demonstrate high maneuverability - this may be achieved with a twin-screw ship. Demand for twin-screw ships will therefore increase in near future. Thus, when it comes to the maneuverability of a twin-screw ship, the existing research leaves a lot to be desired as it primarily focuses on container ships. For these reasons, it is crucial that thorough research is performed on the maneuverability of other styles of twin-screw ships, such as naval combatants.Most studies on the manoeuvrability of twin-screw ships have focused on container ships as there is an abundance of existing data available for them. However, container ships tend to have less manoeuvring problems compared to other types of ships. Thus, when it comes to the manoeuvrability of a twin-screw ship, the existing research leaves a lot to be desired as it primarily focuses on container ships. For these reasons, it is crucial that thorough research is performed on the manoeuvrability of other types of twin-screw ships, such as naval combatants.The main goal of this research is to assess the manoeuvrability of the twin-screw naval combatant ship the DTMB 5415 using Computational Fluid Dynamics (CFD) and MATLAB.In this research, Star-CCM+ is used as a RANS solver to measure the hydrodynamic forces and moments on the twin-screw and derive the hydrodynamic derivatives. To validate the simulated results, a comparison is made against the existing experimental data from the published literature. Following this, MATLAB will be used to predict the manoeuvrability of the vessel in question such as its turning ability and course changing ability. A Mathematical Modelling Group (MMG) model is then used to predict the individual hydrodynamic forcesof the propeller and hull

Impact of framework structure of ordered mesoporous carbons on the performance of supported Pt catalysts for oxygen reduction reaction

Ordered mesoporous carbons (OMCs) are investigated as support materials for Pt catalysts for oxygen reduction reaction (ORR). Three types of OMCs (CMK-3, CMK-3G, and CMK-5) are prepared by a nanocasting method using ordered mesoporous silica, SBA-15, as a template. These OMCs with the same hexagonal mesostructure have different carbon frameworks and graphiticity, which can affect their surface area and microporosity. Pt nanoparticles with an average size of 1 nm are uniformly supported on the three OMCs and Ketjenblack� and their electrochemical performance and durability are evaluated. Pt/CMK-3G exhibits the highest electrochemically active surface area, kinetic current density, mass activity, and half-wave potential, whereas Pt/CMK-3 shows the lowest values. Pt/CMK-3G also shows the highest ORR activity after an accelerated durability test, with a minimal shift in half-wave potential. The higher ORR activity of Pt/CMK-3G is attributed to the formation of highly crystalline Pt particles as well as its highly graphitic, crystalline carbon structure, which causes the weak adsorption of surface oxide and a strong interaction between the Pt particles and the support. Moreover, we can establish that the mass activity of the catalysts is nearly inversely proportional to the micropore volume of the carbon supports.close2

Durability of Pt Catalysts Supported on Ordered Mesoporous Carbon for Proton Exchange Membrane Fuel Cells

Ordered mesoporous carbons (OMCs) are investigated as support materials of Pt catalyst in proton exchange membrane fuel cells. Four types of Pt/OMC catalysts are prepared and their electrochemical performances and durability are evaluated by cyclic voltammetry and linear sweep voltammetry using a rotating disk electrode system. Pt nanoparticles of 2-3 nm seem to be uniformly dispersed on the supports regardless of the kind of OMC. The different pore structure between CMK-3 and CMK-5 affects the surface areas of carbon supports and the resulting Pt nanoparticles with indicating that larger surface area accompanies higher oxygen reduction reaction (ORR) activity. Although the graphitization of carbon support from CMK-3 to CMK-3G reduces the surface area of carbon support, the surface area and the ORR activity of Pt nanoparticles on CMK-3G are increased. In general, the reductions in electrochemical surface area (ECSA) and ORR activity become more noticeable in proportion to the initial ECSA and ORR of Pt/OMC after accelerated durability test

Building an eco-industrial park as a public project in South Korea. The stakeholders' understanding of and involvement in the project

This study aims to investigate the actual development of an eco-industrial park (EIP) in South Korea by employing a case study approach and deals with a pilot eco-industrial park project in the Macheon Industrial Park of Jinhae, Gyeongnam, in the south of Korea. This paper reviews the stakeholders' understanding of EIPs. Furthermore, research was conducted on the barriers to the actual promotion of the project in South Korea. First, stakeholders' understanding of EIPs is identified as being self-interested. The need for EIPs is mostly found in responding to civil complaints and pollutants resulting from the industrial park. However, the need is quite different from the original intention of EIPs. As a result, the project unsuccessfully deals with the needs of the stakeholders because of technical, economic, and social obstacles. Second, support from the public sector for the project seems quite inadequate. The public sector appears to lack the proper policy means and will to actualize the project. In conclusion, the Korean government needs to participate more actively in the project than it currently is doing. Copyright © 2007 John Wiley & Sons, Ltd and ERP Environment.