Non-uniform reinforced concrete brace facade systems are newly considered to improve seismic performance of reinforced concrete frame buildings under lateral load. For normal and high strength concrete of 30MPa, 80MPa, and 120MPa, the cross-sections of reinforced concrete brace facade systems were designed as different size with same amount of reinforcements. The strengthened frame systems were analyzed by a non-linear two-dimensional finite element technique which was considering material non-linearities of concrete and reinforcing bars under monotonic and cyclic loadings. From the study of non-linear analysis of the systems, therefore, it was provided that the proposed braced facade systems were reliable to improve laterally load-carrying capacity and minimize damages of concrete members through comparisons of load-displacement curves, crack patterns, and stress distributions of reinforcing bars predicted by current non-linear finite element analysis of frame specimens.

Cellulose has experienced a renaissance as a precursor for carbon fibers (CFs). However, cellulose possesses intrinsic challenges as precursor substrate such as typically low carbon yield. This study examines the interplay of strategies to increase the carbonization yield of (ligno-) cellulosic fibers manufactured via a coagulation process. Using Design of Experiments, this article assesses the individual and combined effects of diammonium hydrogen phosphate (DAP), lignin, and CO2 activation on the carbonization yield and properties of cellulose-based carbon fibers. Synergistic effects are identified using the response surface methodology. This paper evidences that DAP and lignin could affect cellulose pyrolysis positively in terms of carbonization yield. Nevertheless, DAP and lignin do not have an additive effect on increasing the yield. In fact, combined DAP and lignin can affect negatively the carbonization yield within a certain composition range. Further, the thermogravimetric CO2 adsorption of the respective CFs was measured, showing relatively high values (ca. 2 mmol/g) at unsaturated pressure conditions. The CFs were microporous materials with potential applications in gas separation membranes and CO2 storage systems.

In this study, a vibrating nozzle using the waste vibration energy of the compressor body was installed in the suction flow path to improve the efficiency of the compressor through the pre-compression. To this end, the behavior of the suction valve according to the vibrating nozzle and the mass flow rate of the refrigerant entering the compression chamber were numerically analyzed. The results showed that the mass flow rate increased proportionally as the angle of the vibration nozzle increased. Among the profile shapes of the vibration nozzle, the concave or straight shape showed the highest mass flow rate. Considering the ease of machining, the straight shape is more favorable. On the other hand, as the operating frequency and stroke of the vibration nozzle increased, the mass flow rate also increased proportionally. It can be seen that the largest nozzle angle, operating frequency, and stroke are favorable for pre-compression unless the suction flow is restricted.. In the future, it is necessary to apply the vibrating nozzle system to an actual compressor model to experimentally check the compressor's cooling power, compression work and EER.

In this research, a new piston pinhole boring machine for simultaneous 3-axis machining using linear motor and tilting unit is developed. We propose a new method that combines the linear motor and tilting unit to overcome the limitations of existing techniques. By using the linear motor, we suggest oval machining of piston pin holes. The horizontal reciprocating motion of the linear motor allows for oval machining, creating horizontal or vertical ovals on the pin holes based on the spindle tool's rotation angle. For profile machining of piston pin holes, we propose the use of a tilting unit that converts servo motor motion into linear motion. The vertical motion of the tilting unit enables profile machining, allowing the spindle tool connected to it to translate vertically during spindle rotation and shape the pin holes. To ensure simultaneous oval and profile machining, we suggest channel synchronization, separating the oval and profile machining channels. Synchronizing these channels enables both oval and profile machining to be performed simultaneously on the pin holes. In summary, this research aims to develop a piston pinhole boring machine that effectively utilizes the linear motor and tilting unit for accurate and productive pin hole machining, achieving simultaneous 3-axis machining.

In this research, a new structure of an asymmetric piston dedicated machining center is developed. By applying 2 linear motors in this machine, the slide unit structure could be simplified by comparing to the ball screw method, resulting in easier maintenance of the machine and enabling simultaneous machining in 2 axes and high-speed precision machining. In addition, a dedicated HMI for the asymmetric piston is developed to support efficient operation by workers, allowing them to verify product quality and take necessary actions. It is confirmed that by fully utilizing control libraries and productive programming languages, immediate response to future demands could be achieved. Through speed control loop performance testing, it is confirmed that applying feedforward function could improve the response speed, control accuracy, and stability of the speed control loop. The application of polynomial interpolation and Newton interpolation in the actual machining of asymmetric pistons confirmed the achievement of dynamic machining precision at high speeds. The developed machine and HMI are expected to contribute significantly to the efficiency, productivity, and improvement of product quality in the machining of asymmetric pistons.

A 13-year-old mixed dog was referred to the animal medical center, Gyeongsang National University. Lung masses were diagnosed at the left cranial and caudal lobes through diagnostic imaging, and consequently, left pneumonectomy was performed using a self-cutting linear endoscopic stapler. The pulmonary arteries, veins, and bronchus of each lung lobe were sealed and resected at once, and any air leakage or bleeding was not observed after the surgery. Compared to the conventional ligation method, the self-cutting linear endoscopic stapler has the advantage of significantly reducing the operation time and enabling simple and reliable sealing.

Well-crystallized vanadium pentoxide V2O5 thin films are fabricated on MgO single crystal substrates by using pulsed-laser deposition technique. The linear optical transmission spectra are measured and found to be in a wavelength range from 300 to 800 nm; the data are used to determine the linear refractive index of the V2O5 films. The value of linear refractive index decreases with increasing wavelength, and the relationship can be well explained by Wemple’s theory. The third-order nonlinear optical properties of the films are determined by a single beam z-scan method at a wavelength of 532 nm. The results show that the prepared V2O5 films exhibit a fast third-order nonlinear optical response with nonlinear absorption coefficient and nonlinear refractive index of 2.13 × 10−10 m/W and 2.07 × 10−15 cm2/kW, respectively. The real and imaginary parts of the nonlinear susceptibility are determined to be 3.03 × 10−11 esu and 1.12 × 10−11 esu, respectively. The enhancement of the nonlinear optical properties is discussed.