• Mass Spectrometry Letters
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• 제11권4호
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• pp.108-112
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• 2020

A certified reference material (CRM) for the analysis of nutrient elements in an edible mushroom (Ganoderma lyceum) powder has been developed (KRISS CRM 108-10-011). The mass fractions of calcium (Ca), iron (Fe), and zinc (Zn) were measured by isotope dilution inductively coupled plasma mass spectrometry (ID ICP/MS). To dissolve the fungi cell wall of mushroom consisted of chitin fibers, sample preparation method by single reaction chamber type microwave-assisted acid digestion with acid mixtures was optimized. The mean measurement results obtained from 12 sample bottles were used to assign as the certified values for the CRM and the between-bottle homogeneities were evaluated from the relative standard deviations. The certified values were metrologically traceable to the definition of the kilogram in the International System of Units (SI). This CRM is expected to be used for validation of analytical methods or quality control of measurement results in analytical laboratories when they determine the mass fractions of elements in mushroom or other similar samples.

• 대한기계학회논문집B
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• 제26권8호
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• pp.1077-1087
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• 2002

The heat (mass) transfer characteristics on the blade surface of a high-turning first-stage turbine rotor for power generation has been investigated by employing the naphthalene sublimation technique. A four-axis profile measurement system is developed successfully for the measurements of local sublimation depth on the curved surface In the leading edge region, there is a good agreement between the present heat (mass) transfer data and the previous result on a turbine blade with a moderate turning angle, but some discrepancies are found in the mid-chord heat (mass) transfer between the two results. The local heat (mass) transfer on the present suction surface is greatly enhanced due to an earlier boundary transition, compared with that on a turbine blade with a moderate turning angle, meanwhile there is only a slight change in the pressure-side heat (mass) transfer between the two different turbine rotors. In general, the heat (mass) transfer augmentation by the endwall vortices is found much higher on the suction surface than on the pressure surface.

• 한국추진공학회지
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• 제16권4호
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• pp.70-79
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• 2012

공력학적 성능을 평가하는 대형 유동 시험장치에서 시험체 입구로 들어가는 유체의 압력, 온도, 유량등은 시험체의 성능 계산에 필수적인 항목이므로, 이 값들을 정확하게 측정하는 것이 중요하다. 본 논문에서는 벨마우스와 레이크를 사용하여 보정 유량 범위가 5 ~ 8 kg/s인 대용량 유량을 계측하는 방법을 연구하였다. 벨마우스는 ISO Standard를 따라 0.5% 정확도를 만족할 수 있도록 설계하였고, 레이크는 등면적으로 배치하도록 설계하였다. 총 9 회의 서로 다른 조건의 시험을 분석한 결과 레이크 레이놀즈 수와 유량값의 비가 1차 함수 관계에 있음을 확인하였고, 이 관계식을 이용하여 레이크의 유량값을 벨마우스의 값을 기준으로 최대 -0.507%, 평균 -0.000274% 오차율로 보정할 수 있었다.

• Mass Spectrometry Letters
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• 제10권1호
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• pp.11-17
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• 2019

Drosophila melanogaster (fruits fly) is a representative model system widely used in biological studies because its brain function and basic cellular processes are similar to human beings. The whole head of the fly is often used to obtain the key function in brain-related diseases like degenerative brain diseases; however the biomolecular distribution of the head may be slightly different from that of a brain. Herein, lipid profiles of the head and dissected brain samples of Drosophila were studied using electrospray ionization-mass spectrometry (ESI-MS). According to the sample types, the detection of phospholipid ions was suppressed by triacylglycerol (TAG), or the specific phospholipid signals that are absent in the mass spectrum were measured. The lipid distribution was found to be different in the wild-type and the microRNA-14 deficiency model ($miR-14{\Delta}^1$) with abnormal lipid metabolism. A few phospholipids were also profiled by comparison of the head and the brain in two fly model systems. The mass spectra showed that the phospholipid distributions in the $miR-14{\Delta}^1$ model and the wild-type were different, and principal component analysis revealed a correlation between some phospholipids (phosphatidylethanolamine (PE), phosphatidylinositol (PI), and phosphatidylserine (PS)) in $miR-14{\Delta}^1$. The overall results suggested that brain-related lipids should be profiled using fly samples after dissection for more accurate analysis.

• 한국지구과학회지
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• 제32권1호
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• pp.12-20
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• 2011

변성암복합체, 옥천층군, 조선누층군 및 화성암류에서 지하 지질분포 및 밀도 불연속면을 파악하기 위해 충주호 주변에 있는 256개 지점에서 중력측정을 실시하였다. 부게 중력이상은 옥천층군에서 높은 값을 가지며 조선누층군으로 갈수록 상대적으로 낮은 값의 분포를 보였다. 지하 밀도 불연속면의 평균심도는 약 2.0 km이며, 전반적으로 문주리층과 황강리층이 서창리층보다 중력기반 심도가 상대적으로 얇으며, 옥천계 동측에 위치한 조선누층군이 옥천층군보다 비교적 두꺼운 기반 심도로 분포된 것으로 파악되었다.

• Mass Spectrometry Letters
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• 제1권1호
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• pp.17-20
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• 2010

As background significantly affects measurement accuracy and a detection limit in determination of the trace amounts of uranium, it is necessary to minimize the impurities in the filaments used for thermal ionization mass spectrometry (TIMS). We have varied the degassing condition such as the heating currents and duration times to reduce the backgrounds from the filaments prepared with zone-refined rhenium tape. The most efficient degassing condition of the heating current and the duration time was determined as 3.5 A and 60 min, respectively. The TIMS measurement combined with the isotope dilution mass spectrometry (IDMS) technique showed that the uranium backgrounds were determined to be in a few fg level from blank rhenium filaments. The background minimized filaments were utilized to measure the uranium isotope ratios of a U030 (NIST) standard sample. The excellent agreement of the measurement with the certified isotope ratios showed that the degassing procedure optimized in this study efficiently reduced the impurity signals of uranium from blank rhenium filaments to a negligible level.

• 한국의상디자인학회지
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• 제25권4호
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• pp.45-57
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• 2023

This research compared and analyzed a representative jacket pattern making method to suggest implications for the mass customization process of clothing. Four types of pattern making methods were selected according to the degree of reflection of human body measurements. Patterns were analyzed according to the size of middle-aged women. The results of this study are as follows. First, it identified and compared the difference in human body measurement and drafting processes required for pattern drafting. Next, as a result of analyzing the manuals and institutional figures presented in the pattern drafting manuals, problems such as B.P. location and compartment of the chest circumference, which are not appropriate, were found and the human body measurement method is different for each pattern making method. Through the above analysis, the advantages and disadvantages of the pattern making methods were identified and proposed improvements and implications for the application to the apaarel mass customization process were presented.

• 한국가스학회지
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• 제22권6호
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• pp.109-122
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• 2018

국내 LPG 미터는 "계량에 관한 법률"에 의거 LPG 정량에 대한 검사가 실시되고 있다. LPG 미터는 "계량에 관한 법률 시행령"에 따라 3년마다 재검정이 실시된다. 검사 시 최대허용오차는 ${\pm}1.0%$ 이내, 사용오차는 ${\pm}1.5%$ 이내이다. 정량 측정 시에는 밀도부액계, 저울, 압력용기를 사용한다. LPG는 온도와 압력에 따라 부피 변화의 정도가 매우 심하다. 현행 정량 측정 방법은 LPG의 부피를 구하기 위해 온도 및 압력, 밀도를 측정해야 하며, 이에 따른 장비들이 필요하다. 반면에 코리올리 질량유량계는 질량유량, 밀도, 온도를 동시에 측정하며, 컴퓨터 프로그램을 사용하여 측정값을 필요한 값으로 변환 및 산출 할 수 있어, 산업현장에서 널리 적용되고 있다. 본 연구에서는 LPG 정량 측정에 대한 기초연구로서, 코리올리 질량유량계를 이용하여 LPG 충전기에서 나온 LPG 부피를 측정했다. 또한, 기존 LPG 충전기 검사방법과의 비교를 통해 코리올리 질량유량계를 이용한 LPG 충전기 검사도 가능하다는 결론을 얻었다.

• 한국대기환경학회지
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• 제23권6호
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• pp.689-698
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• 2007

Particular attention is paid to the validity of PM-10 measurement using beta attenuation method. In this study, the inter-comparison studies were undertaken for PM-10 sampler with different measuring methods. The three beta attenuation monitoring instruments (BAM1020, FH C-14, and DIGS-150) and filter based gravitational method using High Volume Air Sampler were collocated and mass concentrations were compared from August to November, 2006. The results of the investigation show that beta attenuation monitoring instruments are comparable with gravitational method within 10% of measurement error. For specific conditions under high humidity and high concentrations, the inter-comparison results also showed a relatively good agreement and this can be explained as the effect of inlet heating of beta attenuation instrument. Subsequently, this study shows that beta attenuation monitoring instruments can be equivalently used with reasonable validity when compared gravimetric method.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 추계학술대회논문집
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• pp.358-362
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• 2002

The HDD unbalance, with higher rotational speed, is directly influenced by the mechanical assembly allowance between clamping disk and platter disk. The low frequency structural vibration induced by the unbalance force finally gives rise to the structure borne noise of the personal computer. To meet the noise and vibration requirements, the absolute unbalance mass of HDD needs to be measured and adjusted in the disk assembling stage. This study introduces the measurement methods of the absolute magnitude and position of the unbalance mass of HDD based on the mobility and acceleration orbit. The absolute unbalance mass can be obtained by the acceleration responses and the mobility of the mechanical part, while the position of the unbalance mass ran be obtained by the rotation acceleration orbit.