• Asian-Australasian Journal of Animal Sciences
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• v.14 no.6
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• pp.862-879
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• 2001

The walls of all higher plants are organized as a cellulosic, fibrillar phase embedded in a matrix phase composed of non-cellulosic polysaccharides, some proteins and, in most secondary walls, lignin. At the effective utilization of plant biomass, qualitative and quantitative analyses of plant cell walls are essential. Structural features of individual components are being clarified using newly developed equipments and techniques. However, "empirical" procedures to elucidate plant cell walls, which are not due to scientific definition of components, are still applied in some fields. These procedures may give misunderstanding for the effective utilization of plant biomass. In addition, interesting the investigation of wall organization is moving towards not only qualitatively characterisation, but also quantitation of the associations between wall components. These involve polysaccharide-polysaccharide and polysaccharide-lignin cross-links. Investigation of the associations is being done in order to understand the chemical structure, organization and biosynthesis of the cell wall and physiology of the plants. Procedures for qualitative and quantitative analyses based on the definition of cell wall components are reviewed focussing in nutritional elucidation of forage grasses by ruminant microorganisms.

• Journal of Chest Surgery
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• v.45 no.3
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• pp.177-182
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• 2012

Background: Tuberculous abscess of the chest wall is a very rare disease. Few articles have reported on it and those that have enrolled few patients. To determine the characteristics of this disease and to suggest an optimal treatment strategy, we reviewed patients treated by surgical management. Materials and Methods: Between October 1981 and December 2009, 68 patients treated by surgical management for a tuberculous abscess of the chest wall were reviewed retrospectively. Results: Of 33 men and 35 women, 31 patients had a current or previous history of tuberculosis. The main complaints were chest pain, a palpable mass, pus discharge, and coughing. A preoperative bacteriologic diagnosis was performed in 12 patients. Abscess excision was performed in 54 cases, abscess cavity excision and partial rib resection in 13, and abscess excision and partial sternum and clavicle excision in 1 case. Postoperative wound infection was noted in 16 patients and a secondary operation was performed in 1 patient. Recurrence occurred in 5 patients (7.35%). Reoperation with abscess excision and partial rib resection was performed in all of the 5 cases. Conclusion: Complete excision of the abscess and primary closure of the wound with obliteration of space would decrease postoperative complications. Anti-tuberculosis medication may reduce the chance of recurrence.

• Corrosion Science and Technology
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• v.16 no.1
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• pp.23-30
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• 2017

The inhibition effect of thioureido imidazoline inhibitor (TAI) for flow accelerated corrosion (FAC) at different locations for an X65 carbon steel elbow was studied by array electrode and computational fluid dynamics (CFD) simulations. The distribution of the inhibition efficiency measured by electrochemical impedance spectroscopy (EIS) is in good accordance with the distribution of the hydrodynamic parameters at the elbow. The inhibition efficiencies at the outer wall are higher than those at the inner wall meaning that the lower inhibition efficiency is associated with a higher flow velocity, shear stress, and turbulent kinetic energy at the inner wall of the elbow, as well as secondary flow at the elbow rather than the mass transport of inhibitor molecules. Compared to the static condition, the inhibition efficiency of TAI for FAC was relatively low. It is also due to a drastic turbulence flow and high wall shear stress during the FAC test, which prevents the adsorption of inhibitor and/or damages the adsorbed inhibitor film.

• Journal of the Korean Solar Energy Society
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• v.39 no.5
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• pp.65-78
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• 2019

In this study, we investigated the paraffin encapsulation using double-walled encapsulation technique. The first encapsulation used methyl methacrylic acid as the main component in acrylic polymer and the second encapsulation used melamine polymer. Particles size and distribution of the capsules were analyzed using scanning electron microscopy. In the first encapsulation, the stable capsules were obtained at 67% of phase change material ratio to methyl methacrylic acid monomer and the size of the capsule was from 0.2 to $0.3{\mu}m$. In the second encapsulation, the size of the capsules was almost the same with those capsules prepared in the first encapsulation. The particle size of single wall and double wall was about $0.3{\mu}m$. As a result of the encapsulation of paraffin using double-walled encapsulation technique, it was confirmed that the particle size was determined in the process of encapsulating using the acrylic polymer at the first wall material, and the physical and thermal stability of the capsules were imparted using melamine at the secondary wall material.

• Journal of the Korean Society of Propulsion Engineers
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• v.25 no.3
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• pp.1-13
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• 2021

Effects of the nozzle wall angles on the supersonic flow field in a thrust optimized nozzle were numerically investigated. The combustor and operating condition of 30-tonf rocket engine was selected to study the optimum nozzle shape. The nozzle flow of combustion products was realized by the shifting equilibrium calculation for the propellant of kerosene-LOx. The change of nozzle wall angles induced different developing patterns of the internal and secondary shock wave. The optimum nozzle was obtained when the internal shock was in a specific position at the nozzle outlet. The nozzle wall angles of the optimum nozzle were very similar to those of the optimum nozzle which does not consider the shock wave.

• Nuclear Engineering and Technology
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• v.53 no.8
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• pp.2488-2498
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• 2021

The wall film-wise condensation plays an important role in the heat transfer processes of heat exchangers, refrigerators, and air conditioner. In the field of nuclear engineering, steam condensation is often utilized in safety systems to remove the core decay heat under both transient and accident conditions. In particular, passive containment cooling system (PCCS), are designed to ensure containment safety under severe accident conditions. A computational fluid dynamics (CFD) scale analysis has been conducted to calculate the heat transfer rate of the PCCS. However, despite the increase in computing power, there are challenges in the long-term transient simulation of containment using CFD scale codes. In this study, a heat structure coupling between the CFD and system analysis codes was performed to efficiently analyze PCCS. In addition, the component unstructured program for interfacial dynamics (CUPID) was improved to analyze the condensation behavior of ternary gas mixtures. Thereafter, the condensation heat transfer on the primary side was calculated using the improved CUPID and CFD code, whereas that on the secondary side was simulated using MARS. Both the coupled codes were validated against the CONAN facility database. Finally, conjugate heat transfer simulations with wall condensation in the presence of non-condensable gases were appropriately performed.

• Transactions of the Korean Society of Mechanical Engineers
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• v.19 no.7
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• pp.1675-1683
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• 1995

A numerical study of the fluid flow and heat transfer characteristics of the two-dimensional impingement jet with a confinement plate has been carried out. The fluid flow was calculated by solving the full Navier-Stokes equation. In doing that, the well known SIMPLER algorithm was used and the trouble making convection term was discretized according to QUICKER scheme. The energy equation was simply solved by using the SOR method. For the Reynolds number of 10000, two channel heights, say 1.5 and 3.0 times the jet exit width, and two thermal boundary conditions constant wall temperature and constant wall heat flux were considered. Discrete heat sources were flush mounted along the impingement plate at a distance of 0, 2, 3, 4, 5, 6, 10, 12, times the jet exit width from the stagnation point. The length of each heat source is 4 times the jet exit width long. The Nusselt number averaged over each heat source was compared with experiment. Comparison shows that both calculations and experiment have the secondary peak of Nusselt number at downstream of stagnation point, even though there is a little quantitative difference in between. The difference is believed due to abscure thermal boundary condition in experiment and also accuracy of turbulence model used. The secondary peak is shown to be caused by rigorous turbulent flow motion generated as the wall jet flow is retarded and developes into the channel flow without flow reversal.

• Journal of Chest Surgery
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• v.30 no.12
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• pp.1247-1250
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• 1997

A 13-year-old boy presented with anterior chest wall depression and dyspnea on exertion(NYHA II). He underwent Ravitch operation for pectus excavatum 7 years ago. A preoperative echocardiographic study revealed secundum atrial septal defect. He had no other abnormality of laboratory test, except FVC and FEVI were decreased into 2.03 L(7 %) and 1.82 L(71 %). He underwent repair of secondary anterior chest wall deformity and secundum atrial septal defect. We used unique method, raising sternum at right angle to secure good operative field for open heart surgery. Acute respiratory insufficiency was developed on postoperative day 1. Mechanical ventilation was applied which could be weaned on postoperative day 6 and thereafter hospital course was uneventful without any other sequale. He was discharged on postoperative day 19.

• Journal of the Korea institute for structural maintenance and inspection
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• v.18 no.4
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• pp.138-146
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• 2014

Structural safety as well as variety and aesthetics of building facade are currently gathering more attention in building construction and stone curtain wall is widely used in exterior wall. However, two main problems are existed in curtain wall construction method. One is an uniformity of construction quality and the other is a repair work of stone panels. Also, the noise and vibration occurring in construction may be cause of civil complaint. Therefore, a new method is needed to overcome these problems. This paper presents a new stone curtain wall system using under cut anchor and secondary holes that was developed in this study. Additionally, structural performance evaluation was conducted to verify the constructability and structural safety for wind pressure and seismic load. Through the evaluation of this method, improved constructability and economic efficiency were verified.

• Corrosion Science and Technology
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• v.15 no.4
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• pp.182-188
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• 2016

Significant piping wall thinning caused by Flow-Accelerated Corrosion (FAC) and Erosion-Corrosion (EC) continues to occur, even after the Mihama Power Station unit 3 secondary pipe rupture in 2004, in which workers were seriously injured or died. Nuclear power plants in many countries have experienced FAC and EC-related cases in steam cycle piping systems. Korea has also experienced piping wall thinning cases including thinning in the downstream straight pipe of a check valve in a feedwater pump line, the downstream elbow of a control valve in a feedwater flow control line, and failure of the straight pipe downstream of an orifice in an auxiliary steam return line. Cause analyses were performed by reviewing thickness data using Ultrasonic Techniques (UT) and, Scanning Electron Microscope (SEM) images for the failed pipe, and numerical simulation results for FAC and EC cases in Korea Nuclear Power Plants. It was concluded that the main cause of wall thinning for the downstream pipe of a check valve is FAC caused by water vortex flow due to the internal flow shape of a check valve, the main cause of wall thinning for the downstream elbow of a control valve is FAC caused by a thickness difference with the upstream pipe, and the main cause of wall thinning for the downstream pipe of an orifice is FAC and EC caused by liquid droplets and vortex flow. In order to investigate more cases, additional analyses were performed with the review of a lot of thickness data for inspected pipes. The results showed that pipe wall thinning was also affected by the operating condition of upstream equipment. Management of FAC and EC based on these cases will focus on the downstream piping of abnormal or unusual operated equipment.