• Title/Summary/Keyword: C2F6

Search Result 2,879, Processing Time 0.03 seconds

A Research on Subjective Symptoms of Fatigue of Housewives at Shin-Chon Area in Seoul (피로 자각증상표에 의한 일부 신촌지역 주부들의 피로도에 관한 일 연구)

  • 이광옥;신공범
    • Journal of Korean Academy of Nursing
    • /
    • v.9 no.2
    • /
    • pp.27-38
    • /
    • 1979
  • This study was undertaken to determine the subjective symptoms of fatigue among the house-wives groups. Inquiries into subjective symptoms of fatigue were made by the form designied by the Industrial Fatigue Research Committee of the Japan Society of Industrial Health (1961), Comprising 30 items. These items are classified into 3 groups of 10 items, namely, A) Physical Symptoms, B) Mental Symptoms, C) Neuro-Sensory Symptoms (Figure 1 ). The results of the investigation can be summerized as follows: 1. Within the total items (T), the physical symptoms (A) were the strongest in the effect on the feelings of fatigue, and were followed by (B), and (C). 2. There was a significant difference shown in the distribution of responses by height (X$^2$=236.29, d.f. = 145, p < 0.00001). In the mental category (F = 2.22, d.f. = 4, p = 0.05) and neuro-sensory category (F = 2.64, d.f. = 4, p < 0.001), there was a difference in the responses’com-plaints by weight. 3. As for the ages, housewives at the age of 50 presented a higher rate than those 30 or 20. 4. Regarding the number of children, respondents have more children showed higher frequency rate of complaints. 5. In the investigation sample, complaints were related to education level (f = 18.34, d.f. = 3, p<0.0001) pentruation (t = 2.31, p< 0.022), and sleeping hours (F = 6.04, d.f. = 6, p< 0.0001).

  • PDF

Identification of Tetrachloroethylene Sorption Behaviors in Natural Sorbents Via Sorption Models

  • Al Masud, Md Abdullah;Choi, Jiyeon;Shin, Won Sik
    • Journal of Soil and Groundwater Environment
    • /
    • v.27 no.6
    • /
    • pp.47-57
    • /
    • 2022
  • A number of different methods have been used for modeling the sorption of volatile organic chlorinated compounds such as tetrachloroethylene/perchloroethylene (PCE). In this study, PCE was adsorbed in several natural sorbents, i.e., Pahokee peat, vermicompost, BionSoil®, and natural soil, in the batch experiments. Several sorption models such as linear, Freundlich, solubility-normalized Freundlich model, and Polanyi-Manes model (PMM) were used to analyze sorption isotherms. The relationship between sorption model parameters, organic carbon content (foc), and elemental C/N ratio was studied. The organic carbon normalized partition coefficient values (log Koc = 1.50-3.13) in four different sorbents were less than the logarithm of the octanol-water partition coefficient (log Kow = 3.40) of PCE due to high organic carbon contents. The log Koc decreased linearly with log foc and log C/N ratio, but increased linearly with log O/C, log H/C, and log (N+O)/C ratio. Both log KF,oc or log KF,oc decreased linearly with log foc (R2 = 0.88-0.92) and log C/N ratio (R2 = 0.57-0.76), but increased linearly with log (N+O)/C (R2 = 0.93-0.95). The log qmax,oc decreased linearly as log foc and log C/N increased, whereas it increased with log O/C, log H/C and log (N+O)/C ratios. The log qmax,oc increased linearly with (N+O)/C indicating a strong dependence of qmax,oc on the polarity index. The results showed that PCE sorption behaviors were strongly correlated with the physicochemical properties of soil organic matter (SOM).

Production of a Keratinolytic Protease by a Feather-Degrading Bacterium, Bacillus megaterium F7-1 (우모분해세균 Bacillus megaterium F7-1에 의한 Keratinolytic Protease의 생산)

  • 손홍주;박근태;김용균
    • Korean Journal of Microbiology
    • /
    • v.40 no.1
    • /
    • pp.43-48
    • /
    • 2004
  • Bacillus megaterium F7-1 producing keratinolytic protease was isolated from decayed chicken feather. The optimal culture conditions for the production of keratinolytic protease by B. megaterium F7-1 were investigated. The composition of optimal medium for the keratinolytic protease was 0.2% glucose, 0.8% skim milk, 0.05% NaCl, 0.01 % $(K_2HPO_4$, 0.02%, $(KH_2PO_4$ and 0.01 % $MgCl_2$. Especially, skim milk was found to be the most effective compound in keratinolytic protease production. The optimal temperature and initial pH were 6.5 and $25^{\circ}C$, respectively. The keratinolytic protease production under optimal condition reached a maximum of 269 U/ml after 5 days of cultivation. B. megaterium F7-1 degraded 98% of the feather used in the optimized medium within 6 days.

A Study on the Properties of WS $i_{x}$ Thin Film with Formation Conditions of Polycide (폴리사이드 형성 조건에 따른 WS $i_{x}$ 박막 특성에 관한 연구)

  • 정양희;강성준;김경원
    • The Transactions of the Korean Institute of Electrical Engineers C
    • /
    • v.52 no.9
    • /
    • pp.371-377
    • /
    • 2003
  • We perform the physical analysis such that Si/W composition ratios and phosphorus distribution change in the W/S $i_{x}$ thin films according to phosphorus concentration of polysilicon and W $F_{6}$ flow rate for the formation of WS $i_{x}$ polycide used as a gate electrode. We report that these physical characteristics have effects on the contact resistance between word line and bit line in DRAM devices. RBS measurements show that for the samples having phosphorus concentrations of 4.75 and 6.0${\times}$10$^{2-}$ atoms/㎤ in polysilicon, by applying W $F_{6}$ flow rates decreases from 4.5 to 3.5 sccm, Si/W composition ratio has increases to 2.05∼2.24 and 2.01∼2.19, respectively. SIMS analysis give that phosphorus concentration of polysilicon for both samples have decreases after annealing, but phosphorus concentration of WS $i_{x}$ thin film has increases by applying W $F_{6}$ flow rates decreases from 4.5 to 3.5 sccm. The contact resistance between word line and bit line in the sample with phosphorus concentration of 6.0 ${\times}$ 10$^{20}$ atoms/㎤ in polysilicon is lower than the sample with 4.75 ${\times}$ 10$^{20}$ atoms/㎤ After applying W $F_{6}$ flow rates decreases from 4.5 to 3.5 sccm, the contact resistance has been improved dramatically from 10.1 to 2.3 $\mu$ $\Omega$-$\textrm{cm}^2$.

Low Temperature Sintering and Dielectric Properties of BiNbO4 and ZnNb2O6 Ceramics with Zinc Borosilicate Glass

  • Kim, Kwan-Soo;Kim, Shin;Yoon, Sang-Ok;Park, Jong-Guk
    • Transactions on Electrical and Electronic Materials
    • /
    • v.8 no.5
    • /
    • pp.201-205
    • /
    • 2007
  • Low temperature sintering behavior and microwave dielectric properties of the $BiNbO_{4^-}$ and the $ZnNb_2O_{6^-}zinc$ borosilicate glass(ZBS) systems were investigated with a view to applying the composition to LTCC technology. The addition of $10{\sim}30$ wt% ZBS in both systems ensured successful sintering below $900^{\circ}C$. For the $BiNbO_{4^-}ZBS$ system, the sintering was completed when 15 wt% ZBS was added whereas 25 wt% ZBS was necessary for the $ZnNb_2O_{6^-}zinc$ system. Secondary phase was not observed in the $BiNbO_{4^-}ZBS$ system but a small amount of $ZnNb_2O_6$ with the willemite structure as the secondary phase was observed in the $ZnNb_2O_{6^-}ZBS$ system. In terms of dielectric properties, the application of the $BiNbO_{4^-}$ and the $ZnNb_2O_{6^-}ZBS$ systems sintered at $900^{\circ}C$ to LTCC were shown to be appropriate; $BiNbO_{4^-}15$ wt% ZBS($\varepsilon_r=25,\;Q{\times}f\;value=3,700GHz,\;\tau_f=-32ppm/^{\circ}C$) and $ZnNb_2O_{6^-}25$ wt% ZBS($\varepsilon_r=15.8,\;Q{\times}f\;value=5,400GHz,\;\tau_f=-98ppm/^{\circ}C$).

The Ductile Behavior of High-Strength R/C Columns Subjucted to Reversed Cyclic and Axial Loads (축력과 반복횡력을 받는 고강도 R/C기둥의 연성거동 확보)

  • 신성우;이지영;한범석;안종문;이광수
    • Proceedings of the Korea Concrete Institute Conference
    • /
    • 1998.10a
    • /
    • pp.507-512
    • /
    • 1998
  • An experimental investigation was conducted to examine the behavior of high strength R/C columns subjected to reversed cyclic and axial loads and to find the relationship between amounts of lateral reinforcement and axial loads ratios. The test parameters of column specimens were the compressive strength of concrete($f`_c$=250, 320, 460, $517kg/\textrm{cm}^2), $ the yield strength of longitudinal steel($f_y$=3700, $5254kg/\textrm{cm}^2), $ axial load ratio(0.3, 0.5, 0.6$f`_cA_g$). The results indicated that axial load can significantly affect and alter the behavior of HS R/C column under inelastic cyclic loadings. Also we found that the relationship between amounts of lateral reinforcement and axial load ratios was $\rho$ =(0.37η+0.15)f`/f.

  • PDF

Crystal Structure of N,N'-di-tert-butoxycabonyl-2, 7-diazabicyclo[3.3.0]oct-4-ene. (N,N'-di-tert-butoxycabonyl-2,7-diazabicyclo[3.3.0]oct-4-ene의 결정구조)

  • 김문집;이재혁
    • Korean Journal of Crystallography
    • /
    • v.8 no.2
    • /
    • pp.132-137
    • /
    • 1997
  • The crystal structure of N,N'-di-tert-butoxycabonyl-2,7-diazabicyclo[3.3.0]oct-4-ene has been determined from single crystal x-ray diffraction study; C16H26N2O4, Triclinic, P1, a=11.119(1) Å, b=13.638(1) Å, c=6.214(1) Å, α=92.14(1)°, β=103.49(1)°, γ=73.35(1)°, V=877.4(2)Å3, T=293(2)K, Z=2, CuKα(λ=1.5418Å). The structure was solved by direct method and refined by full-matrix least squares to a final R=5.38% for 2389 unique observed F0>4σ(F0) reflections and 225 parameters.

  • PDF

Analysis of Genetic Polymorphism by Bloodtyping in Jeju Horse (혈액형에 의한 제주말의 유전적 다형성 분석)

  • Cho Gil-Jae
    • Journal of Life Science
    • /
    • v.15 no.6 s.73
    • /
    • pp.972-978
    • /
    • 2005
  • The present study was carried out to investigate the blood markers of Jeju horses. The redcell cypes (blood groups) and blood protein types (biochemical polymorphisms) were tested from 102 Jeju horses by serological and electrophoretc procedure, and their phenotypes and gene frequencies were estimated. The blood group and biochemical polymorphism phenotypes observed with high frequency were $A^{af}\;(27.45\%$), $C^{a}\;(99.02\%$), $K^{-}\;(97.06\%$), $U^{a}\;(62.75\%$), $P^{b}\;(36.27\%$), $Q^{c}\;(47.06\%$), $D^{cgm/dghm}\;(13.73\%$), $D^{adn/cgm}\;(9.80\%$), $D^{ad/cgm}$\;(8.82\%$), $D^{dghm/dghm}(7.84\%$), $D^{cgm/cgm}(7.84\%$), $AL^{B}\;(48.04\%$), $GC^{F}\;(99.02\%$), $AlB^{K}\;(97.06\%$), $ES^{FI}\;(36.27\%$), $TF^{F2}\;(25.49\%$), $HB^{B1}\;(45.10\%$), and $PGD^{F}\;(86.27\%$) in Jeju horses, respectively. Alleles observed with high gene frequency were $A^{af}$ (0.3726), $A^{C}$ (0.2647), $C^{-}$ (0.5050), $K^{-}$ (0.9853), $U^{-}$ (0.6863), $P^{b}$ (0.4657), $Q^{c}$ (0.5294), $D^{cgm}$ (0.3039), $HB^{B1}$(0.6863), $PGD^{F}$ (0.9265), $AL^{B}$ (0.6912), $ALB^{K}$ (0.9852), $GC^{F}$ (0.9950), $ES^{I}$ (0.5000) and $TF^{F2}$ (0.4950) in Jeju horses, and sfecific alleles, $D^{cgm(f)}$ (0.0196), $HB^{A}$ (0.0147), $HB^{A2}$ (0.0196), $ES^{G}$ (0.0441), $ES^{H}$ (0.0098), $TF^{E}$TF'(0.0246), $TF^{H2}$ (0.0049) and $PGD^{D}$ (0.0098) were detected in Jeju horses. These preliminary results present basic information for detecting the genetic markers in Jeju horse. and developing a system for parentage verification and individuals identification in jeju horses.

Effect of Neutron irradiation in $Fe_{81}B_{13.5}_Si{3.5}C_2$Amorphous Ribbon (비정질 $Fe_{81}B_{13.5}_Si{3.5}C_2$ 리본의 중성자 조사에 따른 자기적 특성변화)

  • 김효철;홍권표;김철기;유성초
    • Journal of the Korean Magnetics Society
    • /
    • v.10 no.2
    • /
    • pp.49-52
    • /
    • 2000
  • The changes of magnetic properties in neutron irradiated F $e_{81}$ $B_{13.5}$S $i_{3.5}$ $C_2$ amorphous ribbon were studied by X-ray diffraction, hysteresis loop, temperature dependence of magnetization and complex permeability. The fluences of thermal ( $n_{th}$) and fast ( $n_{f}$) neutron were 6.95$\times$10$^{18}$ $n_{th}$ c $m^{-2}$ and 4.56$\times$10$^{16}$ $n_{f}$c $m^{-2}$ , respectively. The changes of XRD Profiles were not observable at the neutron irradiated sample. The complex permeability spectra showed that the permeability from domain wall motion decreased due to the increase of pinning force against domain motion by the neutron irradiation, and the relaxation frequency of rotational magnetization moved to higher frequency region. The measurement of hysteresis loop showed the increase of magnetic softness, related to rotational magnetization, but saturation magnetization was decreased in neutron irradiation sample. The Curie temperature was decreased in the neutron irradiated sample.e.e.e.

  • PDF

Intrageneric Protoplast Fusion between Alkalophilic Bacillus sp. F204 and Bacillus sp. K 17 (호알칼리성 Bacillus sp. F204와 Bacillus sp. K 17의 원형질체 융합)

  • 성낙계;노종수;박석규;정영철
    • Microbiology and Biotechnology Letters
    • /
    • v.16 no.4
    • /
    • pp.275-281
    • /
    • 1988
  • To develop cellulase and xylanase-producing strain by protoplast fusion, alkalophilic Bacillus sp. F204 and K17 were treated with NTG(N-methyl-N'-nitro-N-nitrosoguanidine) and isolated anti-biotics resistant strains of S20 (Km$^r$ , Cm$^r$) and G70 (Str$^r$). The frequency of protoplast formation was about 95% when cells of mid-log phase were treated with 200$\mu\textrm{g}$/ml Iysozyme at 37$^{\circ}C$ for 30-45 minutes. Under addition of 0.4-0.5M sodium succinate, 0.5% casamino acid, 1.5% polyvinylpyrrolidone, 25mM MgC1$_2$ and 50mM CaC1$_2$ to the regeneration medium, the regeneration frequency of Bacillus sp. F204 and K17 was 24.9% and 26.2%, respectively. The fusion frequency was 6.6$\times$10$^{-6}$ in the presence of 30% polyethylene glycol 6000 containing 50mM $Ca^{++}$ at 45$^{\circ}C$ for 5 minutes. Cellulase complex and xylanase activities of fusant were compared with parental strains.

  • PDF