• Proceedings of the SAREK Conference
• /
• 2008.06a
• /
• pp.1249-1254
• /
• 2008

Industrial low temperature waste heat exists sparse in surroundings but its amount is huge. However, large portion of waste heat is discarded due to its poor recovery quality and inferior application technologies. The heat pump system in this research is based on the hybrid combination of compression cycle and absorption cycle in order to recycle various kind of industrial waste heat effectively. The prime objective is to design a compression absorption hybrid heat pump system which can produce high temperature above the level of $90^{\circ}C$ and low temperature of $20^{\circ}C$ at the same time using waste heat water of $50^{\circ}C$. A mathematical simulation was carried out as a basis to design a prototype 3 RT class hybrid heat pump. From the simulation results, fundamental parameters to design the system were obtained.

• Journal of the Korean GEO-environmental Society
• /
• v.14 no.10
• /
• pp.5-9
• /
• 2013

Electrokinetics technology is proposed for improving the recovery metals ion and oil from clay-sandy soil. In order to restore or extract them from clay-sandy soil, the gas produced by anode chamber is re-injected to the clay-sandy soil(sample). Samples produced in this study were completed to verify the proposed performance for 7 days by gradually increasing the pressure to the final pressure of 30psi($2.11kgf/cm^2$) through the compression process. Before compression, the copper rings were inserted into the sample, allowing us to observe the changes in appearance of copper ring after the end of the experiment. In this study, pressurized module and non-pressurized module were tested, respectively. The condition of test is a continuous process and the voltage gradient is 2V/cm during 24 hours. As a result, the efficiency of pressurized module is better than non-pressurized module.

• Journal of Fashion Business
• /
• v.7 no.4
• /
• pp.121-128
• /
• 2003

A new textile material, poly(trimethylene terephthalate) polymer, has been introduced to the textile industry. The structure of PTT is similar to the PET, while the tensile deformation and subsequent recovery property is better than that of PET. In this study, the physical and mechanical properties of textile woven fabrics made of PTT, PET, and nylon 6 yarns as the filling yarn were determined using the Kawabata Evaluation System (KES), including tensile, bending, shearing, compression, and surface related parameters. On top of these measurements, the subjective ratings by evaluators were performed on the fabric samples. From the examination of the stress-strain behavior of the yarn specimens focused on the recovery mode, it was evident that the PTT specimen developed lower stress at 3% elongation. The subsequent recovery curve showed that the PTT has less stress-decay rate than the other specimens, implying that the recovery behavior of the PTT is recommendable for the end-uses including stretchable textile materials, sports wears, etc. The KES bending rigidity(B) value of the PTT sample fabric was lower than that of the PET sample fabric. Subjective evaluation of the fabric samples by the evaluators on the descriptive word pair "soft - not soft" showed similar tendency with the KES B determination of the fabric samples.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.45 no.12
• /
• pp.1031-1038
• /
• 2017

In order to improve the performance of the air breathing engines, it is important to maximize the total pressure recovery through air intake. In this study, we investigated whether the Oswatitsch method, which guarantees the maximum pressure recovery for supersonic intake, is effective at hypersonic speed by compressing the intake air with the same intensity at each ramp. The non-linearity of the shock wave normal Mach number at each ramp stage was analyzed by comparing the compression ramp angle and the number of ramp to the inflow Mach number in terms of compressible thermodynamics and the operation limits of the inlet. Based on this analysis, the Oswaitisch technique yields valid conditions not only in supersonic but also hypersonic flight regime.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 2004.05a
• /
• pp.174-177
• /
• 2004

The nickel-based alloy Nimonic 80A possesses strength, and corrosion, creep and oxidation resistance at high temperature. These products are used for aerospace, marine engineering and power generation, etc. The control of forging parameters such as strain, strain rate, temperature and holding time is important because the microstructure change in hot working affects the mechanical properties. It is necessary to understand the microstructure variation evolution. The microstructure change evolution occurs by recovery, recrystallization and grain growth phenomena. The dynamic recrystallization evolution has been studied in the temperature range $950-1250^{\circ}C$ and strain rate range $0.05-5s^{-1}$ using hot compression tests. The metadynamic recrystallization and grain growth evolution has been studied in the temperature range $950-1250^{\circ}C$ and strain rate range 0.05, $5s^{-1}$, holding time range 5, 10, 100, 600 sec using hot compression tests. Modeling equations are developed to represent the flow curve, recrystallized grain size, recrystallized fraction and grain growth phenomena by various tests. Parameters of modeling equation are expressed as a function of the Zener-Hollomon parameter. The modeling equation for grain growth is expressed as a function of initial grain size and holding time.

• The Journal of Churna Manual Medicine for Spine and Nerves
• /
• v.5 no.1
• /
• pp.81-89
• /
• 2010

Objects : This study was to report a clinical effect of Chuna Treatment for a patient diagnosed by Magnetic Resonance Imaging(MRI) as Cervical Myelopathy. Methods: In order to alleviate shoulder pain and neck stiffness, the patient was treated by acupuncture therapy, herbal medicine, phamacopucture, cervical traction technique of Chuna treatment and conservative managements. To evaluate the effect of the treatment, Recovery rate of Hirabayashi, VAS(Visual Anlaogue Scale), NDI and ROM(Range of Motion) were used. Lhermitte's sign, Valsalva test, Distraction test, Compression test and Spurling test were carried out. Results: VAS, NDI and ROM were improved and Recovery rate was 100%. Conclusions: Korean Treatment can be effectively used for a patient with Cervical Myelopathy. Further clinical studies are needed to verify the findings.

• The Journal of Churna Manual Medicine for Spine and Nerves
• /
• v.4 no.1
• /
• pp.85-94
• /
• 2009

Objects : This study was to report a clinical effect of Korean Treatment for a patient diagnosed by Computed Tomography as Cervical Spinal Stenosis with Ossification of posterior Longitudinal Ligament. Methods : In order to alleviate left shoulder pain and neck stiffness, the patient was treated by acupuncture therapy, herbal medicine, distilled herbal injection, cervical traction technique of Chuna treatment and conservative managements. To evaluate the effect of the treatment, Recovery rate of Hirabayashi, VAS(Visual Anlaogue Scale), NDI and ROM(Range of Motion) were used. Lhermitte's sign, Valsalva test, Distraction test, Compression test and Spurling test were carried out. Results : VAS, NDI and ROM were improved and Recovery rate was 100%. Conclusions : Korean Treatment can be effectively used for a patient with Cervical Spinal Stenosis with OPLL. Further clinical studies are needed to verify the findings.

• The Journal of Churna Manual Medicine for Spine and Nerves
• /
• v.5 no.1
• /
• pp.145-156
• /
• 2010

Objects: This study was to report a clinical effect of Chuna Treatment for a patient diagnosed by Magnetic Resonance Imaging(MRI) as Cervical Myelopathy. Methods: In order to alleviate shoulder pain and neck stiffness, the patient was treated by acupuncture therapy, herbal medicine, pharmacopucture, cervical traction technique of Chuna treatment and conservative managements. To evaluate the effect of the treatment, Recovery rate of Hirabayashi, VAS(Visual Analogue Scale), NDI and ROM(Range of Motion) were used. Lhermitte's sign, Valsalva test, Distraction test, Compression test and Spurling test were carried out. Results: VAS, NDI and ROM were improved and Recovery rate was 100%. Conclusions: Korean Treatment can be effectively used for a patient with Cervical Myelopathy. Further clinical studies are needed to verify the findings.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• v.9 no.2
• /
• pp.763-767
• /
• 2005

RAID were proposed to stored double data or used to parity logging methode for error recovery. We describe a technique for automating the execution of redundant disk array operation, including recovery from errors, independent of array architecture. RAID5 provide highly reliable cost effective secondary storage with high performance for read access and large write accessed. It discusses the two architectural techniques used in disk arrays, striping across multiple disks to improve performance and redundancy to improve reliability. In this paper we compare with performance and reliability in RAID5 real/write to file and stripe size. than suggest to algorithm.

• Transactions of Materials Processing
• /
• v.7 no.6
• /
• pp.620-630
• /
• 1998

Conventional hot forging and thixoforging of Al 7075 alloy have been compared with respect to microstructures, formability and hardness. Two distinctive temperature-strain rate ranges for hot forging of Al 7075 alloy were observed from the results of simple compression tests with strain rates of 10-3∼101 sec-1 in the temperatures between $250^{\circ}C$ and $500^{\circ}C.$ In the dynamic recovery range (low temperature-high strain rate range) multi-stage forging was necessary to form a complex shape part due to the lack of formability. In the high temperature-low strain rate range, in which dynamic recrystallization takes place a complex shaped park could be formed by single-stage forging. About 50% cold working in the SIMA process was necessary to get a fine and homogeneous microstructures. Microstructural study suggest that thixoforged Al 7075 part has fine grains and homogeneous microstructures. Its hardness number is almost same to that of conventional hot forged part after aging treatment.