• Title/Summary/Keyword: Mass-estimation

Search Result 780, Processing Time 0.024 seconds

A Method to Determine Amount of Adsorbed Oil in Hair Washing Using Absorption Spectroscopy (흡수 분광법을 이용한 세정 과정에서 흡착된 오일의 평가)

  • Song, Sang-Hun;Kim, Hyun young;Son, Seong Gil
    • Journal of the Society of Cosmetic Scientists of Korea
    • /
    • v.45 no.2
    • /
    • pp.105-116
    • /
    • 2019
  • Oil adsorption during hair or body washing is responsible for the hair conditioning. In this study, we established a method to extract oil from a substrate, and to determine amount of adsorbed oil upon substrate using a conventional absorption spectroscopy. We controlled the mole fraction of a surfactant in a mixture of anionic and amphoteric surfactants because that it induces the coacervate that regulates amount of adsorbed oil through the alteration of oil viscosity. Based on this, we established the optimized condition for adsorption and extraction for oil. UV absorbance were employed to estimate the amount of adsorbed oil using optical absorbance after extraction via adsorption. The estimation was confirmed by comparing with a mass analysis in HPLC and an adhesive energy in AFM. It has been proved that this method can be applied to all cases of oil adsorption from the results with various cationic polymers and a complex system of the polymers which regulate the oil adsorption.

Improvement of In-Situ Stress Measurements by Hydraulic Fracturing - Focusing on the New Standard by Japanese Geotechnical Society (수압파쇄를 이용한 초기응력 측정 결과의 신뢰도 제고 방안 - 일본 지반공학회 표준시험법 개정안을 중심으로)

  • Kim, Hyung-Mok;Lee, Hangbok;Park, Chan;Park, Eui-Seob
    • Tunnel and Underground Space
    • /
    • v.32 no.1
    • /
    • pp.1-19
    • /
    • 2022
  • In this report, new standard, published by Japanese Geotechnical Society, on in-situ stress measurements by hydraulic fracturing was reviewed. In the standard, modification was made for the calculation of fracture re-opening pressure in consideration of fracture surface roughness and residual aperture. The standard also presents how much the system compliance influences the estimation of the fracture re-opening pressure and subsequent in-situ stresses. It is shown that the stiffer the rock mass is, the system compliance should be sufficiently small enough so as to obtain in-situ stress measurement with higher confidence.

Gadolinium- and lead-containing functional terpolymers for low energy X-ray protection

  • Zhang, Yu-Juan;Guo, Xin-Tao;Wang, Chun-Hong;Lu, Xiang An;Wu, De-Feng;Zhang, Ming
    • Nuclear Engineering and Technology
    • /
    • v.53 no.12
    • /
    • pp.4130-4136
    • /
    • 2021
  • By polymerization of gadolinium methacrylate (Gd (MAA)3), lead methacrylate (Pb(MAA)2) and methyl methacrylate (MMA), Gd and Pb were chemically bonded into polymers. The X-ray shielding performance was evaluated by Monte Carlo simulation method, and the results showed that the more metal functional organic monomer, the better the shielding performance of terpolymers. When the X-ray energy is 65 keV, Gd (MAA)3-containing polymers have better shielding performance than Pb(MAA)2-containing polymers. Gd could compensate for the weak absorption region of Pb. Therefore, polymers containing both Gd and Pb enhanced shielding efficiency against X-ray in various low-energy ranges. For obtaining terpolymers with uniform monomer compositions, the relationship between the monomer composition of the terpolymers and the conversion level was optimized by calculating the reactivity ratios. The value of reactivity ratios of r (Gd (MAA)3/Pb(MAA)2), r (Pb(MAA)2/Gd (MAA)3), r (Gd (MAA)3/MMA), r (MMA/Gd (MAA)3), r (Pb(MAA)2/MMA) and r (MMA/Pb(MAA)2) was 0.483, 0.004, 0.338, 2.508, 0.255, 0.029. The terpolymers with uniform monomer composition could be obtained by controlling the monomer compositions or conversion levels. The results can provide new radiation protection materials and contribute to the improvement in nuclear safety.

Uplift Capacity Estimation of Bond-type Rock Anchors Based on Full Scale Field Tests (실규모 현장시험을 통한 부착형 암반앵커의 인발저항력 평가)

  • Kim, Dae-Hong;Oh, Gi-Dae
    • Journal of the Korean Geotechnical Society
    • /
    • v.25 no.10
    • /
    • pp.5-15
    • /
    • 2009
  • This paper presents the results of full-scale uplift load tests performed on 24 passive anchors grouted to various lengths at Okchun and Changnyong site. Rock anchors were installed over a wide range of rock types and qualities with a fixed anchored depth of 1~6 m. The majority of installations used D51 mm high grade steel rebar to induce rock failure prior to rod failure. However, a few installations included the use of D32 mm rebar at relatively deeper anchored depth so as to induce rod failure. In many tests, rock failure was reached and the ultimate loads were recorded along with observations of the shape and extent of the failure surface. In addition to field tests, laboratory pullout tests were conducted to determine bond strength and bond stress-shear slip relation at the tendon/grout interface when a corrosion protection sheath is installed in the cement-based grout. The test results show that the ultimate tendon-grout bond strength is measured from 18~25% of unconfined compressive strength of grout. One of the important results from these tests is that the measured strains along the corrosion protection sheath were so small that practically the reduction of bond strength by the presence of sheath would be negligible.

Change of AMC due to Climatic Change (기후변화에 따른 선행토양함수조건(AMC)의 변화)

  • Yoo, Chulsang;Park, Cheong Hoon;Kim, Joong Hoon
    • KSCE Journal of Civil and Environmental Engineering Research
    • /
    • v.26 no.3B
    • /
    • pp.233-240
    • /
    • 2006
  • One of the main factor that effects on the CN's value in SCS Curve Number method for the estimation of direct runoff is the antecedent soil moisture condition (AMC). It is also common to use the AMC-III in hydrologic practice, which provides the largest runoff as possible. In this paper, AMC defending on the rainfall characteristics is analyzed using daily rainfall data at rainy season (June~September) of the Seoul station from 1961 to 2002. The probability mass function of AMC is also investigated to analyze the variation of AMC based on climate change, scenarios from several General Circulation Model (GCM) predictions. As a results we can find that the occurrence of AMC-I is reduced, and AMC-III is increased, whereas AMC-II does not change.

Assessments of the GEMS NO2 Products Using Ground-Based Pandora and In-Situ Instruments over Busan, South Korea

  • Serin Kim;Ukkyo Jeong;Hanlim Lee;Yeonjin Jung;Jae Hwan Kim
    • Korean Journal of Remote Sensing
    • /
    • v.40 no.1
    • /
    • pp.1-8
    • /
    • 2024
  • Busan is the 6th largest port city in the world, where nitrogen dioxide (NO2) emissions from transportation and port industries are significant. This study aims to assess the NO2 products of the Geostationary Environment Monitoring Spectrometer (GEMS) over Busan using ground-based instruments (i.e., surface in-situ network and Pandora). The GEMS vertical column densities of NO2 showed reasonable consistency in the spatiotemporal variations, comparable to the previous studies. The GEMS data showed a consistent seasonal trend of NO2 with the Korea Ministry of Environment network and Pandora in 2022, which is higher in winter and lower in summer. These agreements prove the capability of the GEMS data to monitor the air quality in Busan. The correlation coefficient and the mean bias error between the GEMS and Pandora NO2 over Busan in 2022 were 0.53 and 0.023 DU, respectively. The GEMS NO2 data were also positively correlated with the ground-based in-situ network with a correlation coefficient of 0.42. However, due to the significant spatiotemporal variabilities of the NO2, the GEMS footprint size can hardly resolve small-scale variabilities such as the emissions from the road and point sources. In addition, relative biases of the GEMS NO2 retrievals to the Pandora data showed seasonal variabilities, which is attributable to the air mass factor estimation of the GEMS. Further studies with more measurement locations for longer periods of data can better contribute to assessing the GEMS NO2 data. Reliable GEMS data can further help us understand the Asian air quality with the diurnal variabilities.

The relationship between shift work pattern and thyroid stimulating hormone in female workers

  • Hun Jeong;Chang Ho Chae;Jun Ho Lee;Hyo Won Chong
    • Annals of Occupational and Environmental Medicine
    • /
    • v.35
    • /
    • pp.14.1-14.10
    • /
    • 2023
  • Background: Shift work is known to cause changes in the circadian rhythm of the human body and adversely affect not only physical health but also mental health. Some studies have demonstrated the correlation between shift work and thyroid stimulating hormone (TSH), a hormone that changes according to the diurnal rhythm, but few studies have reported the different TSH levels according to the shift work type. This study aimed to investigate changes in TSH according to the shift work type. Methods: This study included 1,318 female workers who had a medical checkup at a university hospital in Changwon from 2015 to 2019. Shift work types were classified as non-shift work, regular 2 shifts, and irregular three shifts, and a TSH ≥ 4.2 mIU/L was defined as abnormal. A general linear model (GLM) was used to compare the TSH levels and the risk of subclinical hypothyroidism in each year, and a binary logistic analysis was performed using a generalized estimation equation (GEE) to compare the risk of subclinical hypothyroidism over the 5-year period. Results: Of the 1,318 participants included in this study, 363, 711, and 244 were non-shift, two-shift, and irregular three-shift workers, respectively. In the GEE analysis, after adjusting for age, body mass index, smoking, and alcohol consumption, the odds ratios (ORs) were 1.81 (95% confidence interval [CI]: 1.15-2.86; p = 0.011) in 2 shifts and 2.02 (95% CI: 1.23-3.32; p = 0.006) in irregular three shifts, compared to non-shift. Conclusions: Our results showed that shift work had a higher risk of subclinical hypothyroidism than non-shift work and that there was a significant difference in the risk of subclinical hypothyroidism according to the shift work type. These findings suggest that the shift work type can be considered in future thyroid function tests and evaluations.

ML-based prediction method for estimating vortex-induced vibration amplitude of steel tubes in tubular transmission towers

  • Jiahong Li;Tao Wang;Zhengliang Li
    • Structural Engineering and Mechanics
    • /
    • v.90 no.1
    • /
    • pp.27-40
    • /
    • 2024
  • The prediction of VIV amplitude is essential for the design and fatigue life estimation of steel tubes in tubular transmission towers. Limited to costly and time-consuming traditional experimental and computational fluid dynamics (CFD) methods, a machine learning (ML)-based method is proposed to efficiently predict the VIV amplitude of steel tubes in transmission towers. Firstly, by introducing the first-order mode shape to the two-dimensional CFD method, a simplified response analysis method (SRAM) is presented to calculate the VIV amplitude of steel tubes in transmission towers, which enables to build a dataset for training ML models. Then, by taking mass ratio M*, damping ratio ξ, and reduced velocity U* as the input variables, a Kriging-based prediction method (KPM) is further proposed to estimate the VIV amplitude of steel tubes in transmission towers by combining the SRAM with the Kriging-based ML model. Finally, the feasibility and effectiveness of the proposed methods are demonstrated by using three full-scale steel tubes with C-shaped, Cross-shaped, and Flange-plate joints, respectively. The results show that the SRAM can reasonably calculate the VIV amplitude, in which the relative errors of VIV maximum amplitude in three examples are less than 6%. Meanwhile, the KPM can well predict the VIV amplitude of steel tubes in transmission towers within the studied range of M*, ξ and U*. Particularly, the KPM presents an excellent capability in estimating the VIV maximum amplitude by using the reduced damping parameter SG.

A Study on the Estimation of Monthly Average River Basin Evaporation (월(月) 평균유역증발산량(平均流域蒸發散量) 추정(推定)에 관(關)한 연구(硏究))

  • Kim, Tai Cheol;Ahn, Byoung Gi
    • Korean Journal of Agricultural Science
    • /
    • v.8 no.2
    • /
    • pp.195-202
    • /
    • 1981
  • The return of water to the atmosphere from water, soil and vegetation surface is one of the most important aspects of hydrological cycle, and the seasonal trend of variation of river basin evaporation is also meaningful in the longterm runoff analysis for the irrigation and water resources planning. This paper has been prepared to show some imformation to estimate the monthly river basin evaporation from pan evaporation, potential evaporation, regional evaporation and temperature through the comparison with river basin evaporation derived from water budget method. The analysis has been carried out with the observation data of Yongdam station in the Geum river basin for five year. The results are summarized as follows and these would be applied to the estimation of river basin evaporation and longterm runoff in ungaged station. 1. The ratio of pan evaporation to river basin evaporation ($E_w/E_{pan}$) shows the most- significant relation at the viewpoint of seasonal trend of variation. River basin evaporation could be estimated from the pan evaporation through either Fig. 9 or Table-7. 2. Local coefficients of cloudness effect and wind function has been determined to apply the Penman's mass and energy transfer equation to the estimation of river basin evaporation. $R_c=R_a(0.13+0.52n/D)$ $E=0.35(e_s-e)(1.8+1.0U)$ 3. It seems that Regional evaporation concept $E_R=(1-a)R_C-E_p$ has kept functional errors due to the inapplicable assumptions. But it is desirable that this kind of function which contains the results of complex physical, chemical and biological processes of river basin evaporation should be developed. 4. Monthly river basin evaporation could be approximately estimated from the monthly average temperature through either the equation of $E_w=1.44{\times}1.08^T$ or Fig. 12 in the stations with poor climatological observation data.

  • PDF

Clinical Study on Primary Mediastinal Tumors and Cysts -Report of 344 Cases- (원발성 종격동 종양 및 낭종에 대한 임상적 고찰 -344예에 대한 보고-)

  • Lee, Hong-Lyeol;Kim, Se-Kyu;Kim, Hae-Kyun;Chung, Kyung-Young;Lee, Doo-Yun;Kim, Sung-Eun;Chang, Joon;Kim, Sung-Kyu;Lee, Won-Young
    • Tuberculosis and Respiratory Diseases
    • /
    • v.40 no.5
    • /
    • pp.575-583
    • /
    • 1993
  • Background: Mediastinal masses are not uncommon, and an overall incidence of one case per 100,000 population per year in individuals of all ages and with no difference in sex incidence may be a reasonable estimation. At least half of all mediastinal masses are asymptomatic and this proportion has increased in recent decades with wider use of screening chest roentgenography. Symptoms in patients with mediastinal mass lesions are usually due to compression or invasion of nearby intrathoracic structures. Most mediastinal mass lesions have characteristic predilectional locations. The basic focus of diagnostic evaluation is an orderly preparation for obtaining a tissue diagnosis but even lesions discovered to be benign must generally be removed. Seldom is this status known for certain preoperatively. In additaion, benign tumors may continue to enlarge, thus compromising vital organs; they may rupture, hemorrhage, become infected or have the possibility of various malignant degeneration. Therefore, all mediastinal masses must be surgically removed whether they are malignant or benign. Methods: We reviewed the medical records of 344 cases previously confirmed as mediastinal tumors or cysts from January, 1960 to August, 1992 and investigated the clinical findings. Results: Neurogenic tumors were the most common(24.7%) and thymomas were distinctively increased recently. Overall ratio between males and females was 1.1:1 and age distribution was relatively even among all age groups. Predilectional sites were posterior for neurogenic tumors, and anterior for teratodermoid tumors, thymomas and lymphomas. Dyspnea was the most common symptom in the patients of the mediastinal tumors and asymptomatic patients were 19.5%, Benign mediastinal mass lesions were 66.0% and malignant, 34.0%, Complete or partial resection was done in 42.4%. Conclusion: We could find the increasing incidence and the tendency of aggressive resection as possible in the mediastinal tumors. We expect the discovery of more mediastinal tumors with wider use of regular check-up and development of diagnostic methods.

  • PDF