• 한국기계가공학회지
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• 제19권1호
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• pp.29-35
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• 2020

Car inspection systems are regularly carried out by the state to ensure the safety and emission status of cars, thereby improving the safety and quality of life by reducing fine dust and greenhouse gases that are the main culprits of vehicle defects and air pollution. These automobile inspections are largely divided into either regular or comprehensive inspections. This study analyzed the smoke measuring probes used in the lug - down 3 mode. In the previously issued paper "Improvement of Soot Probe Efficiency for Automotive Emission Measurement," an improved smoke measurement probe(B) improved on the problems that arise from the current smoke measurement probe (A). In this study, a technique that can improve the probe's inhalation efficiency over the improved (B) probes was applied to probes (C). Probe (C) involves a structure designed close to the center of the circumference of the exhaust pipe, and the suction efficiency was improved by adding a variable center unit.

• Journal of Korean Neurosurgical Society
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• 제45권5호
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• pp.318-321
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• 2009

Tension pneumocephalus may follow a cerebrospinal fluid(CSF) leak communicating with extensive extradural air. However, it rarely occurs after diagnostic lumbar puncture, and its treatment and pathophysiology are uncertain. Tension pneumocephalus can develop even after diagnostic lumbar puncture in a special condition. This extremely rare condition and underlying pathophysiology will be presented and discussed. The authors report the case of a 44-year-old man with a basal skull fracture accompanied by pneumothorax necessitating chest tube suction drainage, who underwent an uneventful lumbar tapping that was complicated by postprocedural tension pneumocephalus resulting in an altered mental status. The patient was managed by burr hole trephination and saline infusion following chest tube disengagement. He recovered well with no neurologic deficits after the operation, and a follow-up computed tomography (CT) scan demonstrated that the pneumocephalus had completely resolved. Tension pneumocephalus is a rare but serious complication of lumbar puncture in patients with basal skull fractures accompanied by pneumothorax, which requires continuous chest tube drainage. Thus, when there is a need for lumbar tapping in these patients, it should be performed after the negative pressure is disengaged.

• 대한의용생체공학회:의공학회지
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• 제30권1호
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• pp.18-22
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• 2009

Laser has been widely used in various fields of medicine. Recently, noninvasive low-level laser therapeutic medical devices have been introduced in market. However, low-level laser cannot deliver enough photon density to expect positive therapeutic results in deep tissue layer due to the light scattering property in tissue. In order to overcome the limitation, this study was aimed to develop a negative pressure applied low-level laser probe to optimize laser transmission pattern and therefore, to improve photon density in soft tissue. In order to evaluate the possibility of clinical application of the developed laser probe, ex-vivo experiments were performed with porcine skin samples and laser transmissions were quantitatively measured as a function of tissue compression. The laser probe has an air suction hole to apply negative pressure to skin, a transparent plastic body to observe variations of tissue, and a small metallic optical fiber guide to support the optical fiber when negative pressure was applied. By applying negative pressure to the laser probe, the porcine skin under the metallic optical fiber guide is compressed down and, at the same time, low-level laser is emitted into the skin. Finally, the diffusion images of laser in the sample were acquired by a CCD camera and analyzed. Compared to the peak intensity without the compression, the peak intensity of laser increased about $2{\sim}2.5$ times and FWHM decreased about $1.67{\sim}2.85$ times. In addition, the laser peak intensity was positively and linearly increased as a function of compression. In conclusion, we verified that the developed low-level laser probe can control the photon density in tissue by applying compression, and therefore, its potential for clinical applications.

• 대한환경공학회지
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• 제35권2호
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• pp.137-143
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• 2013

본 연구는 냄새 농도 평가를 위한 공기희석관능법의 단계별 희석가스 제조방법에 관한 것으로, 시료가스와 무취가스를 오리피스 튜브로 조절하여 희석하는 방법에 관한 것이다. 10배 및 30배 희석용 오리피스 튜브를 설계하고, 10, 30, 100, 300 및 1,000배 등의 단계별 희석가스를 10배 및 30배 희석용 오리피스 튜브를 반복적으로 사용하여 다양한 희석배율의 희석가스를 제조할 수 있다. 10배 희석용 오리피스 튜브의 홀 크기는 0.84 mm, 30배 희석용 오리피스 튜브의 홀 크기는 0.32 mm로 제작하였다. 제작된 냄새 평가를 위한 시료가스 희석용 오리피스 튜브에 의한 제조된 희석가스의 균질성은 2%RSD 내외로 우수한 재현성을 확인하였다. 또한, 기존 주사기를 이용하는 공기희석관능법에 의해 제조된 희석가스 농도와 비교하여 90% 이상의 상관성을 보이고 있었다. 진공펌프의 유량 변화에 따른 희석가스의 농도변화가 없이 간단히 진공흡인상자의 전단에 설치하여 활용할 수 있어 향후 다양한 현장 적용 평가 및 공기희석관능법과의 비교 연구를 통하여 현장에서의 복합악취 등의 평가에 활용할 수 있을 것으로 기대된다.