• Title/Summary/Keyword: tCS

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이성체쌍의 열중성자포획단면적비 측정

  • Park, Hy-Eil;Kim, Heon-Jun;Lee, Chul
    • Nuclear Engineering and Technology
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    • v.4 no.4
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    • pp.340-344
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    • 1972
  • Isomeric ratios were measured for the capture of thermal neutron by $^{79}$ Br, $^{80}$ Se, $^{103}$ Rh, $^{115}$ In and $^{133}$ Cs as well as those of epi-cadmium neutron by $^{79}$ Br, $^{80}$ Se and $^{l33}$Cs. The measurements were performed by analysing decay curves obtained by ${\gamma}$-ray spectrometry after irradiation. The counting efficiency curve was determined by using the calibrated standard sources with overall uncertainties of about 1%. Isomeric ratios, given in $\sigma$ high spin/($\sigma$ high spin + $\sigma$ low spin), of $^{80, 80m}$Br, $^{81,81m}$Se, $^{014, 104m}$Rh, $^{116,116m}$In and $^{134, 134m}$Cs produced by thermal neutron activation were found to be 0.21$\pm$0.01, 0.14$\pm$0.02, 0.12$\pm$0.02, 0.69$\pm$0.07 and 0.058$\pm$0.004, respectively, Those values of $^{80, 80m}$Br, $^{81,81m}$Se, and $^{134, 134m}$Cs Produced by epi-cadmium neutron were found to be 0.19$\pm$0.02, 0.29$\pm$0.02 and 0.074$\pm$0.011, respectively. The experimental values obtained were compared with the theoretical values deduced from the statistical model. There were the general agreements between the theory and the experiment.t.

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A Fundamental Study on Early Compressive Strength Improvement of the Blast Furnace Slag Cement Mortar Using the Fine Particle Cement and Gypsum (석고 및 미분시멘트에 의한 고로슬래그 미분말 치환 시멘트 모르타르의 초기강도 향상에 관한 기초적 연구)

  • Han, Cheon-Goo;No, Dong-Hyun
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.4 no.3
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    • pp.90-97
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    • 2009
  • The purpose of the study was to examine basic property at the time of applying cast ('CS' below) and high fineness fine particle cement ('FC' below) as a stimulant to 20% substitution cement mortar of ground granulated blast-furnace slag ('BS' below) to settle a problem that early strength of BS mortar is lowered. The results were as follows. First of all, as a characteristic of fresh mortar, liquidity was reduced as much as BS substitution rate was increased. When substituting CS for BS 20%, it didn't have a large effect regardless of substitution rate. When substituting FC, it was reduced as much as substitution was increased. In the event of compressive strength, it was reduced as much as BS substitution was increased in early age. In age 28, it was somewhat increased by reflection of potential hydraulicity. With regard to improvement of early compressive/bending strength of BS 20% substitution mortar, when substituting CS, in early age, they were a little increased as much as addition rate was increased. When substituting FC, in early and 28 age, they were largely increased as much as substitution rate was increased. To settle a problem that early strength of BS 20% substitution mortar was lowered, CS substitution has a little effect and FC 25% substitution was similar to plain with only OPC. Therefore, when substituting FC 25%, it is expected that its quality will be improved.

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An Implementation of The Embedded-Based Multi Mode Receiver Module & Demuxer (임베디드용 멀티모드 방송 수신 모듈 및 역다중화기 설계 및 구현)

  • Kwon, KiWon;Kim, SeongJun;Park, SeHo;Park, YoungSuk;Hong, SukGun
    • IEMEK Journal of Embedded Systems and Applications
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    • v.6 no.2
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    • pp.62-67
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    • 2011
  • In this paper, Multi Mode Receiver Module is designed in one H/W module for Multi-mode Digital Broadcasting. Multi mode means Digital TV, Mobile TV and Digital Radio on the Broadcasting. and T-DMB, DAB(+), ISDB-T and DVB-T standard. Our Module can receive various broadcasting signal such as ISDB-T, DVB-T and DAB. The Multi mode Receiver Module & demuxer was implemented using the one SoC Chip has good performances to receive the multi mode signals as well as standard interface such as SPI, to connect the main CPU Unit.

Storage stability of reduced sulfur gases in Tedlar bag sampler: Test of two different storing approaches (Tedlar-bag 시료채집법을 이용한 황화합물의 경시적 농도 변화특성: 시료의 생성방식의 차이에 따른 비교연구)

  • Jo, Hyo-Jae;Kim, Ki-Hyun
    • Analytical Science and Technology
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    • v.24 no.3
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    • pp.212-218
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    • 2011
  • In this study, temporal stability of 5 reduced sulfur compounds (RSCs) including ($H_2S$, $CH_3SH$, DMS, $CS_2$, and DMDS) was investigated up to 30 days. To learn the temporal changes in RSC concentration levels, two types of long-term storage experiment were carried out by employing two different approaches for sample storing in Tedlar bag samplers. The first one named as a forward (F) storage method consists of preparing all samples in the beginning of experiment. All these samples were analyzed sequentially through time. The second approach named as a reversed (R) storage method was carried out by preparing each sample through time and by analyzing all of them in the last day. For these experiments, RSC standards were prepared at 10 ppb in 10 L Tedlar bag. The results of both methods were consistent enough to show a tendency of the concentration reduction through time. Moreover, the lightest RSC, $H_2S$ showed the most significant reduction of 84.8% at the end of experiment. To validate difference between these results, t-test was applied to the data obtained between the two methods at 90% significance level. According to t-test, the results of the two approaches were greatly distinguished from 3 RSCs ($H_2S$, $CH_3SH$, and DMDS). The results also indicated that the temporal reduction of RSC differs greatly between light ($H_2S$ and $CH_3SH$) and heavy RSCs (DMS, DMDS, and $CS_2$). The former generally exhibited much significant reduction through time due probably to their lower stability.

An Analysis of ${\gamma}-ray$ Energy Spectra Using the NaI(T1) Scintillation Detector in the Air and Water (NaI(T1) 섬광검출기를 이용한 공기 및 수중에서의 감마선 에너지스펙트럼 분석)

  • Kim, Eun-Sug;Park, Jae-Woo
    • Journal of Radiation Protection and Research
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    • v.21 no.4
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    • pp.285-296
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    • 1996
  • The energy spectra in the air and water of several ${\gamma}-ray$ sources such as Cr-51, Cs-137, Mn-54, Zn-65 have been investigated using the NaI(T1) scintillation detector. General response functions, which can curve fit the measured spectra, have been constructed. We have found that the constructed response functions can successfully represent the measured spectra in the water as well as in the air, It is possible, by comparing the relevant parameters of the response functions, to quantitatively characterize the changing features of the measured spectra as obtained with varying the water depth. Of the response function parameters, those which affect the shape of the full-energy Peak have most notably changed. Besides, those parameters which affect the shapes of the flat continuum, the Compton continuum and edge have also shown slight changes with varying the water depth.

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A Study on Drying Characteristics and Drying Model Development of Korean Ginseng (인삼의 건조특성 구명 및 건조모델 개발에 관한 연구)

  • Choe, Byeong-Min;Lee, Jong-Ho;Park, Seung-Je
    • Journal of Ginseng Research
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    • v.16 no.2
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    • pp.111-123
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    • 1992
  • Drying characteristic data for peeled ginseng were obtained to determine dominant drying factors and fitted with five selected drying models and an empirical model. Among air temperature, relative humidity and diameter of ginseng root, drying air temperature was found to be the most influencing factor on drying rate. Drying velocity appeared faster as the drying temperature increased but its effect was less at high temperature than at low temperature. Quality change during the drying process did not occur except when relative humidity was 75fb. At high relative humidity, skin color of ginseng was turned to light brown. Approximate-Diffusion and the Empirical model for drying were in a good agreement with experimental data. The models are as follows; $.$ Approximate-Diffusion model MR = A$.$exe(-k$.$1) A = 1.72 + 0.407 In(D) - 0.0000963T3 - 0.358 In(RH) + 0.0000945 RH2 B= 1.01 + 0.0195RH - 0.O0518D2 + 0.0708 In(T) - 0.492 In(RHI-D.0000933RH2$.$Empirical model MR= Cl + Cs$.$In(t) Cl= 1.14+0.382 In(D)-0.00008477a-0.139 In(RH)+0.0000664RH2 Cs=0.440-0.0224 In(D)-0.193 In(T)+0.0000464T2-0.00000771RH2

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A Case Study on Optimization of the Sewage Treatment Plant (사례분석을 통한 하수처리장의 최적화에 관한 연구)

  • No, Yeong-Dae;U, In-Seong;Kim, Da-Yeong;Kim, Seong-Tae;Lee, Seon-Hui
    • Proceedings of the Safety Management and Science Conference
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    • 2012.11a
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    • pp.121-131
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    • 2012
  • This study is an analysis about BOD, COD, SS, T-N, T-P of 4Stage-BNR, MLE + CS(Coagulating Sedimentation), Bio-SAC BNR method of construction for 3 largest sewage treatment plants among 12 sewage treatment plants in Incheon. The purpose of this study is improving the operational effectiveness for Incheon sewage treatment plant by introducing the optimized method for quality of the discharged water.

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Fertilizer demand estimated in aspect of crop nutrition (작물영양면(作物營養面)에서 본 비료(肥料)의 수요전망(需要展望))

  • Park, Hoon;Park, Young Sun
    • Korean Journal of Soil Science and Fertilizer
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    • v.9 no.3
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    • pp.165-181
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    • 1976
  • Fertilizer(N,P,K) demand for crop production in 1980, 1990 and 2000 was estimated according to the two proposed models, one of which is fertilizer use efficiency model expressed in $Fn=(Y/E){\cdot}(1-Cs)Eu$, where Fn:fertilizer demand, Y:Crop production estimated, E:nutrient efficiency, Cs:fraction of natural resource nutrient in plant, Eu:fertilizer use efficiency and the other fertilization efficiency model expressed in Fn=Y(1-Cys)/Fe, where Cys:fraction of yield without fertilizer, Fe:fertilization efficiency. Total crop uptake of nutrient and its noncycling portion were estimated as criteria for fertilizer demand and nutrient maintenance. Total crop uptake of N,P,K was 600,000 M/T in 1965 700,000 M/T in 1974 and estimated to 880,000 M/T in 1980, 1,170,000 M/T in 1990 and 1,410,000 M/T in 2000. Fertilizer demand appeares to be about 90% of total crop uptake according to fertilizer use efficiency model and about 87% according to fertilization efficiency model. The noncycling nutrient was about 29% of total crop uptake. Fertilizer demand was almost same to the uptake amount in nitrogen, 1.5 times of uptake in phosphorus and half of uptake in potassium. Varietal development, improvement of soil fertility and cultivation method and development of fertilizer forms appears to decrease fertilizer demand by increasing efficiency term in two models while environmental stress such as low temperature appears to give reverse effect resulting in higher fertilizer demand. Fertilizer consumption in 1974 seemed to be unreasonably high especially in nitrogen and phosphorus and thus the effective use of fertilizer appeared as an urgent problem considering that large fields are still remained in lower fertility.

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Unidirectional Photo-induced Charge Separation and Thermal Charge Recombination of Cofacially Aligned Donor-Acceptor System Probed by Ultrafast Visible-Pump/Mid-IR-Probe Spectroscopy

  • Kim, Hyeong-Mook;Park, Jaeheung;Noh, Hee Chang;Lim, Manho;Chung, Young Keun;Kang, Youn K.
    • Bulletin of the Korean Chemical Society
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    • v.35 no.2
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    • pp.587-596
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    • 2014
  • A new ${\pi}$-stacked donor-acceptor (D-A) system, [Ru(1-([2,2'-bipyridine]-6-yl-methyl)-3-(2-cyclohexa-2',5'-diene-1,4-dionyl)-1H-imidazole)(2,2':6',2"-terpyridine)]$[PF_6]_2$ (ImQ_T), has been synthesized and characterized. Similar to its precedent, [Ru(6-(2-cyclohexa-2',5'-diene-1,4-dione)-2,2':6',2"-terpyridine)(2,2':6',2"-terpyridine)]$[PF_6]_2$ (TQ_T), this system has a cofacial alignment of terpyridine (tpy) ligand and quinonyl (Q) group, which facilitates an electron transfer through ${\pi}$-stacked manifold. Despite the presence of lowest-energy charge transfer transition from the Ru-based-HOMO-to-Q-based-LUMO (MQCT) predicted by theoretical calculations by using time-dependent density functional theory (TD-DFT), the experimental steady-state absorption spectrum does not exhibit such a band. The selective excitation to the Ru-based occupied orbitals-to-tpy-based virtual orbital MLCT state was thus possible, from which charge separation (CS) reaction occurred. The photo-induced CS and thermal charge recombination (CR) reactions were probed by using ultrafast visible-pump/mid-IR-probe (TrIR) spectroscopic method. Analysis of decay kinetics of Q and $Q^-$ state CO stretching modes as well as aromatic C=C stretching mode of tpy ligand gave time constants of <1 ps for CS, 1-3 ps for CR, and 10-20 ps for vibrational cooling processes. The electron transfer pathway was revealed to be Ru-tpy-Q rather than Ru-bpy-imidazol-Q.

Quay Crane Dual-cycle Plan considering Yard Tractor waiting time (야드 트랙터 대기시간을 고려한 크레인 듀얼 사이클 계획)

  • Chung, Chang-Yun;Shin, Jae-Young
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2009.10a
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    • pp.220-221
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    • 2009
  • One of the important performance measure for productivity at container terminals is the working productivity in the quay. working scheduling of quay cranes (QCs) gives a significant impact on the quay working productivity. The recent managers of the terminals pay high interests in equipment investment and operation methods with a new concept in order to enhance the quay working productivity. The double cycle or dual cycle, which is a method to increase the quay productivity with no application of new equipment, but with the change of operations, has been received strong attention in academic research. The majority of studies until this time has been realized the quay work as the bottleneck and focused on those works. However, if the QCs do notver, it the Cs d-trotver,(CT) if t the Cs, there would be the pos ibilf tes that the effectiveness of them is decreasedveaused by the longer, if t the Cs. Thus, this paper, suggests the solutions on the con th scheduling for the dual cycle operation considering the YT.

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