• Transactions of Materials Processing
• /
• v.24 no.4
• /
• pp.280-286
• /
• 2015

Hemming is used to connect two sheet metal components by folding the edge of an outer panel around an inner panel to create a smooth edge. The minimization of hemming defects is critical to the final quality of automobile products because hemming is one of the last operations during fabrication. Designing the hemmed part is not easy and is influenced by the geometry of the bent part. Therefore, the main problem for automotive parts is dimensional accuracy since formed products often deviate geometrically due to large springback. Few numerical approaches using 3-dimensional finite element model have been applied to hemming due to the small element size which is needed to properly capture the bending behavior of the sheet around small die corner and the comparatively big size of automotive opening parts, such as doors, hoods and deck lids. The current study concentrates on the 3-dimensional numerical simulation of hemming for an automotive door. The relationship between the design parameters of the hemming operation and the height difference defect is shown. Quality improvement of the automotive door can be increased through the study of model parameters.

• Transactions of Materials Processing
• /
• v.24 no.4
• /
• pp.256-263
• /
• 2015

Electric resistance spot welding has been used to join overlapped steel sheets in automotive bodies. Recently to reduce weight in automotive vehicles, non-ferrous metals are being used or considered in car bodies for hoods, trunk lids, doors parts, etc. Various welding processes such as laser welding, self-piercing rivet, friction stir welding are being used. In the current study, a new electric resistance heated friction stir spot welding is suggested for the spot welding of non-ferrous metals. The welding method can be characterized by three uses of heat -- electric resistance heating, friction stir heating and conduction heating of steel electrodes -- for the fusion joining at the interfacial zone between the two sheets. The welding process has variables such as welding current, diameter of the steel electrodes, revolutions per minute (rpm) of the friction stir pin, and the insert depth of the stir pin. In order to obtain the optimal welding variables, which provide the best welding strength, many experiments were conducted. From the experiments, it was found that the welding strength could be reached to the required production value by using an electrode diameter of 10mm, a current of 7.6kA, a stirring speed of 400rpm, and an insert depth of 0.8mm for the electric resistance heated friction stir spot welding of 5052 aluminum 1.5mm sheets.

• Parasites, Hosts and Diseases
• /
• v.54 no.6
• /
• pp.787-792
• /
• 2016

Cutaneous leishmaniasis (CL) is a protozoan disease which is endemic in Iran. It is transmitted by the Phlebotomus sand fly. The eyelid is rarely involved possibly because the movement of the lids impedes the sand fly from biting the skin in this region. Here, we report 6 rare cases of eyelid CL. The patients were diagnosed by skin scraping, culture, and PCR from the lesions. Skin scraping examination showed Leishmania spp. amastigotes in the cytoplasm of macrophages. Culture examination was positive for Leishmania spp. PCR was positive for Leishmania major and Leishmania tropica. The lesions were disguised as basal cell carcinoma, chalazion, hordeolum, and impetigo. The patients were treated with intramuscular meglumine antimoniate (20 mg/kg/day) for at least 3 weeks. They showed a dramatic response, and the lesions almost completely disappeared. We emphasized the importance of clinical and diagnostic features of lesions, characterized the phylogenetic relationship of isolated parasites, and reviewed the literature on ocular leishmaniasis.

• Journal of Korean Society of Rural Planning
• /
• v.30 no.2
• /
• pp.69-77
• /
• 2024

As impervious area increases due to urbanization, rainfall on the impervious area does not infiltrate into the ground, and stormwater drains quickly. Low impact development (LID) practices have been suggested as alternatives to infiltrate and store water in soil layers. The practices in South Korea is applied to urban development projects, urban renewal projects, urban regeneration projects, etc., it is required to perform literature research, watershed survey, soil quality, etc. for the LID practices implementation. Prior to the LID implementation at fields, there is a need to simulate its' effect on watershed hydrology, and Storm Water Management Model (SWMM) provides an opportunity to simulate LID practices. The LIDs applied in South Korea are infiltration-based practices, vegetation-based practices, rainwater-harvesting practices, etc. Vegetation-based practices includes bio-retention cell and rain garden, bio-retention cells are mostly employed in the model, adjusting the model parameters to simulate various practices. The bio-retention cell requires inputs regarding surface layer, soil layer, and drain layer, but the inputs for the drain layer are applied without sufficient examination, while the model parameters or inputs are somewhat influential to the practice effects. Thus, the approach to simulate vegetation-based LID practices in SWMM uses was explored and suggested for better LID simulation in South Korea.

• Korean Journal of Food Science and Technology
• /
• v.37 no.3
• /
• pp.334-338
• /
• 2005

Method was developed to efficiently analyze semicarbazide (SEM) in foods. Although SEM is produced by thermal decomposition of blowing agent azodicarbonamide, it is too small to be activated by ultraviolet light or fluorescence. When 2-nitrobenzaldehyde semicarbazone, derivatization of SEM, was analyzed by HPLC with triple column system, coefficient correlation over 0.9997 and detection limit of 0.48 ng/g were observed. SEM level in commercial bottle cap gasket was 812.20-5771.30ng/g. Recoveries for SEM in food and PVC gasket were 83.45-97.33% and 92.12-98.71%, respectively. SEM level in plastic seals of press twist-off metal lids was ND-5771.330ng/g.

• Journal of Korean Ophthalmic Optics Society
• /
• v.9 no.1
• /
• pp.135-143
• /
• 2004

The Human body is subject to two patterns of senescence, both of which are represented in the eye and vision. This article discusses the anatomical and physiological changes in anterior and posterior segments which occur with age. The areas covered include the globe, lids, tears, conjunctiva, cornea, sclera, anterior chamber angle, iris, lens, choroid, vitreous and retina. A sample of 219 individuals between the ages of 50 and 79 years was tested with case history, slit lamp examination, palpebral fissure, horizontal visible iris diameter(HVID) and pupil size. The palpebral fissure decreases with age while HVID remains constant in all age classes. This study suggests that an understanding of anatomical and physiological changes which occur with age is helpful to all eye clinicians because the aging process affects all of the ocular tissues.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2005.03a
• /
• pp.401-408
• /
• 2005

Recently shield TBM tunnellings are being applied to subway construction in Korean cities. Generally these kinds of tunnellings have the problems in the stability of ground such as subsidence because urban subway is constructed in the shallow depth. A sinkhole occurred on the road just above the tunnel during tunneling in Kwangju, so a survey for upper layer of the tunnel was needed. But conventional Ground Probing Radar can't be applicable due to the presence of steel-mesh screen in the shield segment, so no existent geophysical method is applicable in this site. Because the outer surface of each shield segment is electrically insulated, dipole-dipole resistivity method which is popular in engineering site investigation, was tried to this survey for the first time. Specially manufactured flexible ring-type electrodes were installed into the grouting holes at an interval of 2.4 m on the ceiling. The K-Ohm II system which has been developed by KIGAM and tested successfully in many sites, was used in this site. The system consists of 1000Volt-1Ampere constant-current transmitter, optically isolated 24 bit sigma-delta A/D conversion receiver - maximum 12 channel simultaneous measurements, and graphical automatic acquisition software for easy data quality check in real time. Borehole camera logging with circular white LED lighting was also done to investigate the state of the layer. Measured resistivity data lack of some stations due to failing opening lids of holes, shows general high-low trend well. The dipole-dipole resistivity inversion results discriminate (1) one approximately 4 meter diameter cavity (grouted but incompletely hardened, so low resistivity - less than $30{\Omega}m$), (2) weak zone (100-200${\Omega}m$), and (3) hard zone (high resistivity - more than 1000${\Omega}m$) very well for the distance of 320 meters. The 2-D inversion neglects slight absolute 3-D effect, but we can get satisfactory and useful information. Acquired resistivity section and video tapes by borehole camera logging will be reserved and reused if some problem occurs in this site in the future.

• Korean Journal of Environmental Agriculture
• /
• v.33 no.2
• /
• pp.134-137
• /
• 2014

BACKGROUND: Dissipation of herbicides in paddy water varies significantly, being dependent on environmental conditions such as sunlight. The photodegradation under natural sunlight may be one of natural degradation routes of herbicides dissipation. Therefore, the aim of this study was to monitor the degradation of butachlor and pyrazosulfuron-ethyl in paddy water under natural sunlight. METHODS AND RESULTS: The 12 water sample bottles of treatment were covered by quart glass plates, which allow about 90% of UV radiation (280-2000 nm) to pass through, to minimize the UV attenuation. The other 12 water sample bottles of the control were covered by glass lids and wrapped with aluminum foils to prevent the sunlight. The concentration of butachlor and pyrazosulfuron-ethyl in paddy water samples bottles was monitored under ambient conditions with and without natural sunlight. The concentration of butachlor and pyrazosulfuron-ethyl for treatment decreased from $355.3{\mu}g/L$ to $37.8{\mu}g/L$ and from $10.5{\mu}g/L$ to $3.9{\mu}g/L$, respectively, during consecutive 21 days after herbicide application under natural sunlight. CONCLUSION: The concentration of butachlor in paddy water decreased quickly under ambient conditions with natural sunlight. The degradation of butachlor in paddy water was enhanced by the natural sunlight. However, the degradation of pyrazosulfuron-ethyl was insignificant under natural sunlight.

• Archives of Plastic Surgery
• /
• v.33 no.3
• /
• pp.335-340
• /
• 2006

Lower palpebral bags and tear trough grooves are the common signs of aging. Weakness of the orbital septum, atrophy of the orbicularis oculi muscle, slackness and laxity of the lower lid skin are the main causes of these aging changes. Tear trough groove with skeletonization of the lower orbital rim can not be corrected easily by the conventional lower blepharoplasty, but the augmentation of the volume, can be an effective method. Lower lids provide a well vascularized recipient site, which is vital for proper grafting of fat to occur. We treated tear trough groove with free fat graft of surgically removed orbital fat. Surgical excision of the fat pad and septal reinforcement with free fat graft below the levator labii superioris alaeque nasi muscle were performed to correct tear trough groove. This technique was performed in 29 consecutive individuals from October, 2001 to January, 2005. Palpebral bags and tear trough groove were corrected concomitantly and obtained a youthful attractive midface with no secondary hollowness of lower lid and irregularity. The overall results obtained were satisfactory without any complications. Recurrence of tear trough deformity due to grafted fat absorption was not noted during the 7 months of the follow-up period. The authors conclude that the procedure is safe and effective in selected patients.

• Physical Therapy Korea
• /
• v.25 no.4
• /
• pp.27-36
• /
• 2018

Background: We developed a novel integrative lumbar stabilization technique that combines lumbar extension (LE) exercise with abdominal drawing-in maneuver (ADIM) to ameliorate low back pain (LBP) associated with neuromuscular imbalance and instability, based on the collective evidence of contemporary spinal rehabilitation. Objects: The specific aim of the present study was to investigate the effects of LE exercise with and without ADIM on core muscle strength, lumbar spinal instability, and pain, as well as functional characteristics in individuals with LBP using advanced radiographic imaging techniques. Methods: patients with mechanical LBP (N = 40, 6 males; $35.1{\pm}7.6years$) were recruited and randomly assigned either to the combined LE and ADIM (experimental group) or the LE alone (control group). Outcome measures included the visual analog scale, the modified Oswestry Disability Index, muscle strength imbalance (MSI), and radiographic imaging. The lumbar intervertebral displacement (LID), intervertebral (IV) and total lumbar extension (TLE) angles were calculated to evaluate the lumbar segmental instability. Results: The experimental group showed significant differences in the L3-L4, L5-S1 LIDs, L4-L5 and L5-S1 IV angles, and TLE angle as compared to the controls (p<.05). Immediate pain reduction and muscle strength imbalance ratio were significantly different between the groups (p<.05). Conclusion: These results suggest that the addition of ADIM significantly increased lumbar spinal stabilization in individuals with LBP, thereby reducing pain associated with functional lumbar flexion during daily activities.