Papers by Keyword: Duty Factor

Abstract: Living creatures can walk or run more elegant and advanced than any other legged mechanical models. Principles of existing robot systems are based more on technical rather than on biological concepts, yielding unstable locomotion with low speed. In order to apply advanced biological phenomena to the mechanical model, three types of vertebrates are selected, and their structures are modeled by 13 links and 12 joints, covering all existing leg and body arrangements, which is a rigid multi-body system and simulated to obtain optimal conditions by calculating locomotion efficiency, which satisfy the principle of minimum energy expenditure.

Abstract: Legged living creatures can move on any kinds of terrain with good adaptability. They read the terrain conditions and repeat inherent or acquired obstacle crossing sequences, which can be imitated mechanically for the design of a Quadruped. For the prototype model and the step, four corner distances are determined according to the desired body angle and the continuous locomotion sequences are determined. Also, the requirements to satisfy three conditions for step-down are introduced, which makes it possible to determine the exact number of steps in the second phase of step-down. Since step-up is the reverse of step-down, all the governing parameters are the same and the locomotion sequences of step-down are also the reverse of step-up, except for the case of walking-down by gravity. The dimensions of a suggested quadruped are used to calculate the crossing performance for the purpose of comparison.

Abstract: Electrocoagulation (EC) has been proven by a substantial number of studies to be an efficient technology to remove organic pollutants from wastewater. Nevertheless, the high energy consumption of this technology inhibits its extensive application. The objective of this work is to investigate the feasibility of electrical energy conservation and high efficiency by using Pulse Electrocoagulation (PE). PE, a combination of a pulsing technique and EC, was proposed in an attempt to treat the dye wastewater. The results demonstrated that PE, as compared with DCE (direct current electrocoagulation), resulted in up to 51.66% energy conservation by using two iron electrodes as anode and cathode. Moreover, this high energy conservation was obtained during a high level of treatment efficiency: 99.62% of color removal and 91.15% of COD removal for 1000 mg L^-1 4BS solution in a short electrolyzing time of 15 mins.

Abstract: Dry Electrical discharge machining (Dry EDM), using gas as dielectric, has been developed to solve problems against environment. It has both advantages of high material removal ratio (MRR) and low relative electrode wear ratio (REWR). We investigated the effect of duty factor, peak current, and reference ratio of gap voltage on MRR and REWR of Dry EDM, respectively. Moreover, trying to prove the attachment on electrode surface could decline REWR. It is considered that melting material of work-piece was sputtered and stuck onto electrode surface, and to become a protection layer as result in low REWR. However, the attachment will be removed under the condition of high peak current and high discharge frequency. But the amount of attachment just has little change when discharge number and arc discharge ratio are both decrease.