Comparison of different infiltration amounts of CeO2 inside Ni-YSZ anodes to improve stability and efficiency of Single-Chamber SOFCs operating in methane

Electrochemically active oxide-based anodes capable of working in Single-Chamber Solid Oxide Fuel Cells (SC-SOFCs) were developed. Their performance is related to the selectivity of the electrodes. Tests are carried out on lab-scale devices with YSZ pellets as solid electrolytes in electrolyte supported cells. Selecting methane as a fuel, a gas mixture in the ratio CH4/O2 = 2 was chosen. The Ni-YSZ (NiO:YSZ=60:40) anode was optimized through CeO2 nanocatalysts infiltration to enhance the anode catalytic activity and make its reduction easier. Several infiltration amounts were compared, from null to 15% of the electrode weight. Both symmetric and complete cells (with LSCF-based cathodes) were tested in H2 and CH4/O2. For increasing amounts of infiltrated CeO2, symmetric cells tests describe an area specific resistance (ASR) reduction from 40 Ω cm2 to 1.7 Ω cm2 in hydrogen and from 11 Ω cm2 to 3.9 Ω cm2 in the methane/oxygen mixture. While complete cells tests displayed an ASR drop from 30 Ω cm2 to 2.9 Ω cm2 in H2, and from 8.7 Ω cm2 to 4.3 Ω cm2 in the methane/oxygen mixture, while OCP and power grew from 478 mV and 3.7 mW cm-2 to 766 mV and 13 mW cm-2.

Development of a Caterpillar-Type Walker for the Elderly People

A walker assists elderly people with age-related reduced walking ability and helps to improve stability and balance ability. However, if the general-type walker (GTW) is used on an uneven, obstacle, or sloped terrain, it may cause excessive muscle use and falls. Therefore, in this study, we developed a caterpillar-type walker (CTW) that elderly people can safely use in various terrains. Twelve elderly who were able to walk normally participated in the study. The activity of upper and lower extremity muscles, the number of obstacles overcome, and walking speed was compared and analyzed when using two types of walkers in uneven terrain, obstacle terrain, and sloped terrain. In addition, satisfaction with the use of these walkers was evaluated. When CTW was used, the activity of the muscles of the upper and lower extremities was significantly reduced compared to the use of GTW on all terrains. The walker developed in this study overcame obstacles of all heights, but the GTW failed to overcome obstacles starting from the 2 cm section. In terms of walking speed, when the CTW was used, the walking speed was higher than that of the GTW in uneven terrain and obstacle terrain. In satisfaction, there were significant differences in safety, durability, simplicity of use, comfort, and effectiveness. Through these results, it was confirmed that the CTW can efficiently and safely assist the elderly in walking on uneven terrain, obstacle terrain, and inclined terrain.

Evolution of Chewing Force in Geriatric Edentulous Patients

Objective The aim of this study was to assess the evolution of chewing force in edentulous geriatric patients rehabilitated with complete dentures. Chewing function is compromised in individuals who lose all their teeth, as well as in those with complete dentures. The maintenance and recovery of the chewing function in these patients require replacement of the lost natural teeth. Materials and Methods In this study, the chewing force was evaluated by electromyographic analysis of the temporalis and masseter muscle endings in 120 patients with old and new bimaxillary complete dentures. Results Replacement of complete dentures was shown to improve stability, retention, occlusion, and support of the prosthesis. All jaw movements were evaluated using electromyography to assess the evolution of chewing force with and without occlusal adjustment, identify premature contact points, identify occlusal interference, respect the balanced occlusal scheme, and assess the increase in muscle strength. This study found that muscle strength in patients with prosthesis without occlusal adjustment was 527.1 N but was higher for prostheses with occlusal adjustment at 614.7 N, and this strength of 614.7 N was maintained after 1 month of control. Conclusion The chewing force evolved in patients with complete dentures, and an increase was observed when occlusal adjustment was performed.

Estimation of the stability of a fishing vessel during purse seining

One of the reasons for the emergency of a fishing vessel, as well as for the failure of fishing equipment, is the sudden tension of the purse rope, which occurs when the fishing equipment is pulled. As a result of the loss of stability the vessel may enter the encircled seine area and even capsize. There are a number of measures to improve stability during the operation of the vessel. However, when designing fishing equipment, it is necessary to know forces acting on the vessel from the seine side. The article presents a method for assessing the static stability of a vessel with a static application of the tension force of the purse rope. As a result of the study, an expression for determining the static heel angle using a three-dimensional representation of the vessel is given. During simulation the geometrical parameters of the purse rope in the process of purse seine were taken into account. The tension force of the purse rope is also presented as a variable.

Conditions for stability of the “vessel-purse seine” system during purse seining

In the process of tightening the rings of the lower seine line, significant forces of hydrodynamic resistance of the netting can capsize the vessel or pull it into the encircled seine area. There is a risk of damage to the propeller-rudder system of the vessel. The list and trim of a fishing vessel can occur. It affects the safety and comfort of the crew, leads to malfunctions of fishing equipment and mechanisms, and can cause accidents. During the vessel’s operation, there are a number of measures to improve stability. However, when designing fishing equipment, it is necessary to know the forces acting from the seine side on the vessel. The article discusses the relationship between the vessel and the seine during purse seining. On the basis of the developed mathematical model of the tension force of the purse rope, taking into account the geometrical parameters of the warp during purse seining, conditions for stability of the “vessel-purse seine” system were obtained.

An Experimental Study on Electrosparking of Tool Electrode Forced Cooling Based on Micro Heat Pipe Bundle

An electrosparking experiment of ASP30 powder metallurgical steel was carried out through tool electrode forced cooling based on micro heat pipe bundle by using the semiconductor encapsulation mould. Results demonstrate that the micro groove formed among sintered copper fibers based on wick of micro heat pipe and the unique composite structure of the surface chopped morphology can not only increase capillary pressure of the wick, but also strengthen evaporation/condensation process at two ends of the micro heat pipe, and improve cooling effect of micro heat pipe to tool electrode significantly. Compared with traditional electrosparking, electrosparking of tool electrode forced cooling based on micro heat pipe bundle increases the inter-electrode cooling, chip removal and deionization of electrosparking and further lowers tool electrode loss by strengthening heat dissipation of tool electrode. Hence, it can improve stability of electrosparking, increase pulse utilization and increase the processing speed and processing surface quality significantly.