• Journal of Ecology and Environment
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• 제29권3호
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• pp.185-189
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• 2006

고로쇠나무의 수액 채취에 따른 임목 피해를 최소화하고 지속적으로 수액 채취가 가능하도록 하기 위해 적정 천공 크기와 천공 수를 조사하였다. 천공 크기별 수액 채취량은 12 mm 천공에서 189 L, 10 mm 천공에서 140 L, 8 mm 천공에서 193 L가 채취되었다. 천공 크기별 유합율은 8 mm 천공이 100%, 10 mm 천공이 89%, 12 mm 천공이 85% 가 유합되었다. 수액 채취량을 고려한다면 8 mm 천공의 경우 소경목은 3개, 중경목은 2개, 대경목은 3개, 12 mm 천공은 대경목에 2개의 천공이 적합한 것으로 추정된다. DB 도포제를 이용하여 8 mm로 소경목에 $1{\sim}3$개를 천공한 처리목은 $4{\sim}6$개월 만에 유합이 완료되는 것으로 나타났다. 8 mm 천공인 소경목의 l 개소 처리구, 중경목 2개소 처리구, 대경목 3개소 처리구에서 각각 0.60 mm, 1.12 mm, 0.47 mm로 가장 많은 직경 생장량을 나타내었다. 12 mm 천공인 경우의 직경 생장량은 대경목 0.55 mm, 중경목 0.30 mm, 소경목 0.23 mm 의 순으로 나타났다.

• 한국안전학회지
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• 제25권2호
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• pp.1-6
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• 2010

Flow characteristics of differential pressure flow meters which have a shape of triangular separate bar (TSB) was investigated according to the machining conditions in pressure tapping holes. Diameter of the pressure taping holes is either 1.0 mm or 1.5 mm. Also, number of the pressure tapping holes are drilled either 9 or 17. The mass flow rate of the TSB flow meters are calibrated with a laminar flow meter by connecting them in line. The mass flow rate in the TSB flow meters are plotted with a non-dimensional parameter H which includes the gas temperature, exhaust gas pressure and differential pressure at the flow meters. An empirical correlation between the mass flow rate at the TSB flow meter and the non-dimensional parameter H was obtained. The empirical correlation showed highly linear relationship between the mass flow rate and the non-dimensional parameter H. The hole size of the pressure tapping holes has a bigger effect on the flow rate than the number of the tapping holes.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 추계학술대회 논문집
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• pp.304-307
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• 2002

High speed machining was accomplished. through the technological advances which covers the whole field of mechanical industry. But tapping have many troubles because of its complicate cutting mechanism, for example. tool damage, chip elimination and synchronization between spindle rotation and feed motion. But High speed tapping is so important that it marches in step with the flow of the times and make improvement in the productivity. In this paper we analyze mechanism of high speed synchronized tapping with the signal of tapping torque and spindle speed obtained through the newly developed high speed tapping machine(NTT-30B). We made an experiment with this machine on condition of various speed from 1000rpm to 10000rpm. As one complete thread is performed through the whole chamfer cutting, cutting torque increases highly in chamfer cutting, but smoothly in full thread cutting functioning of the threads guide. And the size of cutting torque according to spindle speed(rpm) was not enough of a difference to be conspicuous.

• Journal of Korean Neurosurgical Society
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• 제60권1호
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• pp.1-7
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• 2017

Objective : The diagnosis of shunt malfunction can be challenging since neuroimaging results are not always correlated with clinical outcomes. The purpose of this study was to evaluate the efficacy of a simple, minimally invasive cerebrospinal fluid (CSF) lumbar tapping test that predicts shunt under-drainage in hydrocephalus patients. Methods : We retrospectively reviewed the clinical and radiological features of 48 patients who underwent routine CSF lumbar tapping after ventriculoperitoneal shunt (VPS) operation using a programmable shunting device. We compared shunt valve opening pressure and CSF lumbar tapping pressure to check under-drainage. Results : The mean pressure difference between valve opening pressure and CSF lumbar tapping pressure of all patients were $2.21{\pm}24.57mmH_2O$. The frequency of CSF lumbar tapping was $2.06{\pm}1.26times$. Eighty five times lumbar tapping of 41 patients showed that their VPS function was normal which was consistent with clinical improvement and decreased ventricle size on computed tomography scan. The mean pressure difference in these patients was $-3.69{\pm}19.20mmH_2O$. The mean frequency of CSF lumbar tapping was $2.07{\pm}1.25times$. Fourteen cases of 10 patients revealed suspected VPS malfunction which were consistent with radiological results and clinical symptoms, defined as changes in ventricle size and no clinical improvement. The mean pressure difference was $38.07{\pm}23.58mmH_2O$. The mean frequency of CSF lumbar tapping was $1.44{\pm}1.01times$. Pressure difference greater than $35mmH_2O$ was shown in 2.35% of the normal VPS function group (2 of 85) whereas it was shown in 64.29% of the suspected VPS malfunction group (9 of 14). The difference was statistically significant (p=0.000001). Among 10 patients with under-drainage, 5 patients underwent shunt revision. The causes of the shunt malfunction included 3 cases of proximal occlusion and 2 cases of distal obstruction and valve malfunction. Conclusion : Under-drainage of CSF should be suspected if CSF lumbar tapping pressure is $35mmH_2O$ higher than the valve opening pressure and shunt malfunction evaluation or adjustment of the valve opening pressure should be made.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2009년도 춘계학술대회 논문집
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• pp.1680-1686
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• 2009

삼각 분리 막대형 차압 유량계 압력 탭의 가공 조건에 따른 유량 특성을 연구하였다. 삼각 분리 막대탭 차압 유량계에 가공한 압력 탭의 크기는 1.0 mm 또는 1.5 mm로 하였다. 압력 탭의 개수는 5개 또는 17개로 가공하였다. 삼각 분리 막대탭 차압 유량계와 층류유량계를 직결한 후 유량 특성을 검정하였다. 삼각 분리 막대탭 차압 유량계의 질량 유량을 무차원 파라미터 H를 사용하여 나타내었다. H는 TSB 유량계에서의 배압, 기체 온도, 유량계 상류압과 하류압 간의 차압을 포함하는 무차원 파라미터이다. TSB 유량계의 질량 유량과 H 간에는 선형적 관계를 보였다. 압력 탭의 개수 보다는 압력 탭의 직경이 TSB 차압유량계의 유량 특성에 더 큰 영향을 미쳤다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 추계학술대회 논문집 Vol.16
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• pp.192-195
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• 2003

There has been increasing interest in the applications of synthesized molecules of nanometer scale in recent years due to their potential utilization in various fields such as biology, optoelectronics and molecular electronics. In this study, the terpyridine-platinum (II) complex on the periphery of the dendritic carbosilane has been prepared from the reaction of Pt(COD)Cl2 and the 4'-functionalized-(2,2':6',2"-terpyridine) on dendrimers. The self-assembly process was carried out to obtain indivially dispersed dendrimer on Au (111) substrate. It was found that STM was unsuitable to obtain a obvious image of dendrimers. Tapping-mode atomic force microscopy(AFM) has been used to investigate the shape and size of dendrimers individually dispersed on Au (111)substrate. As a result, the imaged single dendrimer show that dendrimer is dome shaped and its size can be measured by tapping-mode AFM.

• 에너지공학
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• 제21권1호
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• pp.43-46
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• 2012

A fluidized bed drying approach was utilized to the synthesis of water glass based silica aerogel powders. The effects of the fluidized bed drying conditions such as the superficial velocity and temperature of hot air and bead size as well as bead/wet-gel ratio, on the physical properties such as tapping density and productivity of the aerogel powders were systematically investigated. The experimental results showed that the amount of beads mixed with wet-gels in the fluidized bed column has the most profound impact on the fluidization efficiency, greatly enhancing the yield of the aerogel powders up to 98% with a proper bead/wet-gel weight ratio as compared to 72% without using beads. No significant change was observed in the tapping density over a wide range of the fluidized drying condition. Consequently the fluidized bed drying approach shows a good promise as an alternative route for the large-scale production of the aerogel powders.

• Journal of the Korean Wood Science and Technology
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• 제49권2호
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• pp.181-190
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• 2021

Screw-type fasteners are widely used to make connections between wood members or between wood and steel connectors because they can tolerate the applied loads by withdrawal or shearing. In this study, we evaluated the withdrawal resistances of the screw-type fasteners and analyzed the effects of the lead-hole size, relative grain direction (tangential, radial, and cross-sections) of the wood member, screw diameter, screw type, and species. Two wood species, including domestic larch and imported spruce, and three screw-type fasteners, including domestic lag screws (diameters of 9.46, 7.79, and 6.27 mm), domestic tapping screw (diameter, 6.3 mm), and imported Sherpa screw (diameter, 8.0 mm) were used. To assess the effect of lead-hole size, the lead holes with diameters corresponding to 68.7%, 70.8%, and 74.0% of the shank diameter of the lag screw were predrilled. The lead hole corresponding to 74% of the shank diameter was selected for this study because the smaller lead holes required higher rotational force for installation, which may cause damage in the screw neck, although there was no significant difference in the withdrawal resistance depending on the lead-hole sizes applied in this study. The lag screws installed on the tangential and radial surfaces showed similar withdrawal resistances to each other, which were greater than those installed on the cross-sectional surface. As the lag screw diameter increased from 6.27 mm to 9.46 mm, the withdrawal resistance also increased proportionally. The withdrawal resistance of the tapping screw having a diameter of 6.3 mm was almost 1.6 times higher than that of the lag screw having a similar diameter of 6.27 mm, while that of Sherpa screw having a diameter of 8.0 mm was around 1.4 times higher than that of the lag screw having a similar diameter of 7.79 mm.

• KIEE International Transactions on Electrophysics and Applications
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• 제12C권4호
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• pp.229-235
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• 2002

The apparent volume resistivity of powders measured by both the tapping and the compressing methods was compared in this study. Factors such as applied voltage, pressure, corona charging, and so on affecting the apparent volume resistivity of polymer powders were also examined experimentally. Powders of polyacrylonitrile and Nylon 11 were mainly used. The values of the apparent resistivity of polymer powders taken by the tapping method turned out to be larger than those taken by the compressing method, which indicates that the apparent volume resistivity of polymer powders depends strongly on the measurement method. The apparent resistivity of polymer powders increased with an increase in applied voltage while it decreased with an increase in pressure, tapping time, and particle size. The influence of the moisture content of powder and corona charging on the resistivity of polymer powders is also discussed.

• 대한의용생체공학회:의공학회지
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• 제33권1호
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• pp.47-52
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• 2012

The purpose of this study is to investigate whether medication and deep brain stimulation (DBS) have differential effects on the speed and amplitude of bradykinesia in patients with Parkinson's disease (PD). Five PD patients with implanted DBS electrodes (age: $60.6{\pm}7.4yrs$, H&Y stage: $3.1{\pm}0.2$) participated in this study. FT (finger tapping) movement was measured using a gyrosensor system in four treatment conditions: Med (Medication)-off/DBS-off, Med-off/DBS-on, Med-on/DBS-off and Med-on/DBS-on. Quantitative measures representing average speed and amplitude of FT movement included root-mean-squared (RMS) angular velocity and RMS angle. One-way repeated measures ANOVA showed that RMS angular velocity of Med-on/DBS-on was significantly greater than those of Med-off/DBS-off and Med-off/DBS-on (p < 0.01) whereas RMS angle was not different among conditions (p = 0.06). Two way repeated measures ANOVA showed that only medication improved RMS angular velocity (p < 0.01), whereas both medication and DBS had no significant effect on RMS angle (p > 0.02). Effect size of RMS angular velocity was greater than that of RMS angle in both medication and DBS. This suggests that medication and DBS have differential effects on FT bradykinesia and velocity and amplitude impairments may be associated with different functional aspects in PD.