• Title/Summary/Keyword: T2 Measurement

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Design and Characterization of Low-noise Dewar for High-sensitivity SQUID Operation (고감도 SQUID 냉각을 위한 저잡음 듀아의 설계 및 특성 조사)

  • Yu, K.K.;Lee, Y.H.;Kim, K.;Kwon, H.;Kim, J.M.
    • Progress in Superconductivity
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    • v.11 no.2
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    • pp.152-157
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    • 2010
  • We have fabricated the low noise liquid helium(LHe) dewar with a different shape of thermal shield to apply the 64-channel SQUID(Superconducting Quantum Interference Device) gradiometer. The first shape of thermal shield was made of an aluminum plate with a wide width of 100 mm slit and the other shape was modified with a narrow width of 20 mm slit. The two types of dewars were estimated by comparing the thermal noise and the signal-to-noise ratio(SNR) of magnetocardiography(MCG) using the $1^{st}$ order SQUID gradiometer system cooled each dewar. The white noise was different as a point of the dewar. The noise was increased as close as the edge of dewar, and also increased at the thermal shield with the more wide width slit. The white noise of the dewar with thermal shield of 100 mm slit was 6.5 fT/$Hz^{1/2}$ at the center of dewar and 25 fT/$Hz^{1/2}$ at the edge, and the white noise of the other one was 3.5 - 7 fT/$Hz^{1/2}$. We measured the MCG using 64-channel SQUID gradiometer cooled at each LHe dewar and compared the SNR of MCG signal. The SNR was improved of 10 times at the LHe dewar with a modified thermal shield.

The Molecular Weight Dependance of Paramagnetic Gd-chelates on T1 and T2 Relaxation Times (상자성 복합체의 분자량에 따른 T1 및 T2 자기이완시간에 관한 연구)

  • Kim In-Sung;Lee Young-Ju;Kim Ju-Hyun;Sujit Dutta;Kim Suk-Kyung;Kim Tae-Jeong;Kang Duk-Sik;Chang Yong-Min
    • Progress in Medical Physics
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    • v.17 no.2
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    • pp.61-66
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    • 2006
  • To evaluate the T1, T2 magnetic relaxation properties of water molecule according to molecular weight of paramagnetic complex. 4-aminomethyicyclohexane carboxylic acid (0.63 g, 4 mmol) was mixed with the suspension solution of DMF (15 ml) and DTPA-bis-anhydride (0.71 g, 2 mmol) to synthesize the ligand. The ligand was then mixed with $Gd_2O_3$ (0.18 g, 0.5 mmol) to synthesize Gd-chelate. For the measurement of magnetic relaxivity of paramagnetic compounds, the compounds were diluted to 1 mM and then the relaxation times were measured at 1.57 (64 MHz). Inversion-recovery pulse sequence was employed for T1 relaxation measurement and CPMG (Carr-Purcell-Meiboon-Gill) pulse sequence was employed for T2 relaxation measurement. In case of inversion recovery sequence, total 35 images with different inversion time(T1)s ranging from 50 msec to 1,750 msec. To estimate the relaxation times, the signal intensity of each sample was measured using region of Interest (ROI) and then fitted by non-linear least square method to yield T1, T2 relaxation times and also R1 and R2. Compared to T1=($205.1{\pm}2.57$) msec and T2=($209.4{\pm}4.28$) msec of Omniscan (Gadodiamide), which is commercially available paramagnetic MR agent, T1 and T2 values of new paramagnetic complexes were reduced along with their molecular weight. That is, T1 value was ranged from $(96.35{\pm}2.04)\;to\;(79.38{\pm}1.55)$ msec and T2 value was ranged from $(91.02{\pm}2.08)\;to\;(76.66{\pm}1.84)$ msec. Among new paramagnetic complexes, there is a tendency that the R1 and R2 increase as the molecular weight is increases. As molecular weight of paramagnetic complex increases, T1 and T2 relaxation times reduce and thus the increase of relaxivity (R1 and R2) Is proportional to molecular weight.

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Consolidation Behavior of Soft Ground by Prefabricated Vertical Drains (연직드레인 공법에 의한 연약지반의 압밀거동)

  • 이달원;강예묵
    • Proceedings of the Korean Society of Agricultural Engineers Conference
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    • 1998.10a
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    • pp.376-381
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    • 1998
  • The large scaled field test by prefabricated vertical drains was performed to evaluate the superiority of vertical discharge capacity for drain materials through compare and analyze the time-settlement behavior with drain spacing and the compression index and consolidation coefficient obtained by laboratory experiments and field monitoring system 1. The relation of measurement settlement( $S_{m}$) versus design settlement( $S_{t}$) and measurement consolidation ratio( $U_{m}$) versus design consolidation ratio( $U_{t}$) were shown $S_{m}$=(1.0~l.1) $S_{t}$, $U_{m}$=(1.13~l.17) $U_{t}$, at 1.0m drain spacing and $S_{m}$=(0.7~0.8) $S_{t}$, $U_{m}$=(0.92~0.99) $U_{t}$ at 1.5m drain spacing, respectively. 2. The relation of field compression index( $C_{cfield}$) and virgin compression index( $V_{cclab}$) was shown $C_{cfield}$=(1.0~1.2) $V_{cclab}$, But it was nearly same value when considered the error with determination method of virgin compression index and prediction method of total settlement. 3. field consolidation coefficient was larger than laboratory consolidation coefficient, and the consolidation coefficient ratio( $C_{h}$/ $C_{v}$) were $C_{h}$=(2.4 ~ 3.0) $C_{v}$. $C_{h}$=(3.5 ~ 4.3) $C_{v}$ at 1.0m and 1.5m drain spacing and increased with increasing of drain spacingngasing of drain spacingng spacingng

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Clinical Study on Measurement Intervals in the Ultrasonographic Gastric Emptying Test for Functional Dyspepsia (기능성 소화불량에서 초음파 위배출능 측정간격에 대한 임상연구)

  • Kim, Keum-ji;Jeon, Hye-jin;Ko, Seok-jae;Park, Jae-woo
    • The Journal of Internal Korean Medicine
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    • v.41 no.6
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    • pp.1030-1051
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    • 2020
  • Objective: This study investigated the measurement interval in the ultrasonographic gastric emptying test for patients with functional dyspepsia (FD) and the correlation between gastric emptying and the findings of various questionnaires. Methods: In total, 119 patients (59 patients with FD and 60 healthy controls) were recruited from July 2018 to June 2020. Gastric volume (GV) and gastric emptying half-time (T1/2) were measured by ultrasonography at fasting and again at 0, 5, 10, 15, 30, 45, 60, 90, and 120 min after meals (apple juice, 500 mL, 224 kcal), and the average half-time (average T1/2) was calculated. Questionnaires on food retention (FRQ), phlegm pattern e (PPQ), cold and heat (CHQ), deficiency and excess (DEQ), and spleen-qi deficiency (SQDQ), stomach qi deficiency pattern (SSDQ), visual analogue scale (VAS), and Nepean dyspepsia index-Korean version (NDI-K) were completed by all participants. The differences in GV and T1/2 were analyzed in participants whose maximal GV occurred at 0 min versus after 0 min. The correlation of the average T1/2 with the questionnaire scores was also analyzed after excluding erroneous data. Results: Patients with FD who took a certain amount of time to reach maximal GV after meals had a greater gastric volume up to about 30 minutes after meals, and the PPQ, DEQ, and NDI-K scores, especially for upper gastrointestinal symptoms and general weakness-related symptoms, showed statistically significant correlations with average T1/2. Conclusions: Ultrasonography can be a quantitative evaluation tool for FD. However, further studies on measurement methods based on FD physiopathology are required.

Nausea/Vomiting and Anxiety of Hospitalized Cancer Patients Receiving Chemotherapy (항암화학요법을 받는 입원환자의 오심·구토 및 불안 정도에 관한 조사연구)

  • Choi, Ja Yun;So, Hyang-Sook;Cho, In Sook
    • Korean Journal of Adult Nursing
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    • v.16 no.2
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    • pp.211-221
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    • 2004
  • Purpose: The purpose of this study was to describe the pattern of changes on the score of nausea/vomiting and anxiety during one cycle of chemotherapy. Method: A total of 53 subjects who were admitted to C University Hospital for a period of 3 days and 2 nights for chemotherapy were selected from February to April, 2003. Total scores of nausea/vomiting were measured twice a day 3 days for a total of 6 measurements. Anxiety, anorexia, and fatigue were also measured at the first and last measurement points. Data were analyzed by one-way repeated measures, ANOVA, t-test, paired t-test, & Pearson's correlation. Result: The score of nausea/vomiting increased over time except for the 4th measurement point but no changes were significant over time. There were the significant differences between 1st and 2nd, and 2nd and 3rd nausea/vomiting score at p < 0.05. The scores of anxiety, anorexia, and fatigue between the first and 6th points were significantly different(t=-5.69, p=.001; t=6.25, p=.0001; t=3.65, p=.0007). Conclusion: Further studies are needed to identify the relationship between anxiety, and anticipatory and acute nausea/vomiting respectively.

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An investigation on the in si.tu measurement of the oil-concentration

  • Kim, Chang-Nyeun;Park, Young-Moo
    • International Journal of Air-Conditioning and Refrigeration
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    • v.8 no.2
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    • pp.80-88
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    • 2000
  • In order to predict thermodynamic performance of refrigeration system, it is required to know the oil concentration of the refrigerant/oil mixture. The current method is to extract the working mixture and then to measure the oil weight. In this study, oil concentration is measured in si.tu way without any extraction of the working fluid. Based on the measurement, a working equation is presented as follows, C=a +b x t +c x $t^2$ +(d + e x t +f x $t^2$) x SG. C is oil concentration, t is temperature($^{\circ}C). SG Is specific gravity of mixture and a~f is coefficients The oil concentration ranges over 0~l2 wt% and the temperature ranges over 20~50$^{\circ}C. The specific gravity and temperature are measured using the on-line densimeter and thermometer. This working equation enables to predict the oil concentration without any extraction of the mixture. This equation can be applied for R-12/Naphthenic oil and R-134a/P0E oil liquid mixtures.

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The Effects of Foot Reflexology on Pain and Quality of Sleep in Patients with Terminal Cancer (말기 암 환자에게 적용한 발 반사 마사지의 통증경감 및 수면증진 효과)

  • Kim, Eun Joo;Kyong, Boo Soon
    • Journal of Korean Clinical Nursing Research
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    • v.14 no.1
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    • pp.33-44
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    • 2008
  • Purpose: This study was performed to determine the effects of foot reflexology on pain and quality of sleep in patients with terminal cancer. Method: Quai-experimental research design was used. The subjects of this study were consisted of 19 for experimental group and 18 for control group. Visualue Scale(VAS) was used as the measurement tool of pain in this study, Verra & Snyder-Halpern Sleep Scale(VSH) and Visual Analogue Scale(VAS) were used as the measurement tool of perceived quality of sleep. Data were analyzed using statistical methods such as frequency, percent, $x^2$-test, t-test using SPSS WIN 12.0 program. Results: The hypothesis 1 that the experimental group with reflexology has less degree of pain than the control group without reflexology was supported (t=5.41, p<.001). The hypothesis 2 that the experimental group with reflexology has higher degree of VSH Scale than the control group without reflexology was supported(t=2.37, p=.02). The hypothesis 3 that the experimental group with reflexology has the difference among the mean of sleep VAS Scale during the 12 measurement periods was not supported(F=1.63, p=.08), and no significant interactions between group and time. Conclusion: It is considered that reflexology is effective for reducing cancer pain and improving quality of sleep in patients with terminal cancer.

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A Study on Measurement for Earth Resistance of Steel Structure (철탑접지저항 측정에 관한 연구)

  • 박석탁;김시영
    • 전기의세계
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    • v.22 no.6
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    • pp.33-51
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    • 1973
  • To lower the earth resistance shall be one of the most effective method for the prevention of lightening damage on power transmission line. In this report, in order to investigate various characteristic necessary to lowering the earth resistance, the following experiments have been made at 154KV U1San-PoHang T/L, 154KV YoSu-SoonChun T/L and so on. 1. Measurement of Earth specific resistance, 2. Efficiency of Earthing of concrete foundation for steel structure., 3. Efficiency of Earthing with counter poise., 4. Compound impulse test with foundation of steel structure and counter poise. With the above investigate a guidance have been prepared for the effective work-performance of steel structure.

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A Study on Management for Measuring Instrument of Small and Medium-sized Enterprises - Focusing on the Inspection Gig - (중소제조업체의 측정기 운영에 관한 실증적 연구 - 검사 지그를 중심으로 -)

  • Yoo, Hyun-Jong;Jung, Soo-Il
    • Journal of the Korea Safety Management & Science
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    • v.10 no.2
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    • pp.217-223
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    • 2008
  • Measurement is used for evaluation of product or process exactly. If it couldn't measured correctly, Quality-cost must be raised and it would be hard to improve product quality. So, this study suggests improvement guide line for the multilateral problems of measuring instrument operation based on the investigation of 157 small and medium-sized enterprises in February, 2008. To use inspection gig correctly, man who treat it must be accustomed with the structure, the performance, the method. The inspection gig is selected properly for the measurement goal. If not, results couldn't be correctly or wasted time, efforts, and costs. When selecting a inspection gig, the locating, the clamping, and the efficiency must be considered.

Static measurement of yield stress using a cylindrical penetrometer

  • Uhlherr, P.H.T.;Guo, J.;Fang, T.N.;Tiu, C.
    • Korea-Australia Rheology Journal
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    • v.14 no.1
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    • pp.17-23
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    • 2002
  • A novel and simple method using a cylindrical penetrometer is being developed for the measurement of yield stress. The principle of this technique is based on the measurement of the static equilibrium of a falling penetrometer in a yield stress fluid. The yield stress is simply determined by a balance of forces acting on the penetrometer. The yield stress of Carbopol gels and $TiO_2$ suspensions has been measured using this method. The results are in reasonable agreement with the values from conventional methods. The effects of the dimensions and weight of the penetrometer have been examined. The long-term behaviour was also observed. No measurable creep was seen and equilibrium was found to be very quickly established. The cylindrical penetrometer technique promises to be a simple, quick and reliable static method for the measurement of yield stress.