• 여성건강간호학회지
• /
• 제8권3호
• /
• pp.402-411
• /
• 2002

Purpose: The objective of this study was to identify the effectiveness of continued breast feeding and maternal identity between rooming-in and not rooming-in groups of mothers in post partum care. Method: The subjects were selected by convenient sampling, with 95 women in childbirth completing a questionnaire. The data were collected on the 2nd day after delivery by questionnaire, and after the 4th and 8th weeks by telephone interview. Measures used in this study included general characteristics, breast feeding related characteristics, and the maternal identity scale revised by Koh(1996). The data were analyzed with the SPSS program, and the Chi-test and t-test were used to identify the effect on breast feeding and maternal identity. Results: Continued breast feeding up to 4 weeks after deliverly was not statistically significant between rooming-in and not rooming-in group, but beyond 8 weeks of deliverly, it was significantly different in rooming-in group(p<.01). Maternal identity was significantly higher in rooming-in group than in not rooming-in group(<.01). Conclusion: Mothers preferred rooming-in system because it helped breast feeding and baby care. Rooming-in system provides self confidence in taking care of baby, knowledge about breast feeding and stimulates early phase lactation. We recommend rooming-in system in hospitals to promote breast feeding and maternal identity. Nurses are encouraged to discuss prenatal breast feeding before delivery and rooming-in care should be planned individually for continuation of breast feeding and formation of maternal identity.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2001년도 하계학술대회 논문집
• /
• pp.170-173
• /
• 2001

Thin films of phase-pure perovskite (P $b_{0.72}$L $a_{0.28}$) $Ti_{0.93}$ $O_3$(PLT) were deposited in-situ onto Pt/Ti/ $SiO_2$/Si substrates by pulsed laser deposition. We have systematically investigated the variation of grain sizes depending on the process condition. Both in-situ annealing and ex-situ annealing treatments have been compared depending on the annealing time. Two-step process to grow (P $b_{0.72}$L $a_{0.28}$) $Ti_{0.93}$ $O_3$(PLT) films was adopted and verified to be useful to enlarge the grain size of the film and to enhance the leakage current characteristics. The grain sizes of PLT thin films were successfully controlled 260 to 350 nm by changing process parameters. Electrical properties including dielectric constant, ferroelectric characteristics, crystallization and leakage current of PLT thin films were shown to be strongly inf1uenced by grain size. Also PLT thin films on p-type(100) Si substrate will be fabricated by pulsed laser deposition technique using a Nd:YAG laser with different wavelengths of 355, 532 and 1064 nm. Effect of the variation of laser wavelength on dielectric properties will be discussed. Microstructural and electrical properties of the film were investigated by C-V measurement leakage current measurement and SEM.ent and SEM.

• 한국수소및신에너지학회논문집
• /
• 제13권2호
• /
• pp.151-158
• /
• 2002

The hydorgen storage alloys were produced by melting in arc melting furnace and then solution heat treated at $1,100^{\circ}C$ followed by pulverization. The chemical analysis on the samples showed that the major elements of misch metal(Mm) were La, Ce, Pr and Nd with impurity less than 1wt.%. X-ray diffraction indicated that the structure for these samples were a single phase of hexagonal with $CaCu_5$ type. Compared to the initial particle size $100{\sim}110{\mu}m$, the many fine cracks were found and particle size decreased to $14{\mu}m$ for $MmNi_{4.5}Mn_{0.5}$ after hydriding/dehydring test run. To activate the sample the vessel filled with hydrogen storage alloys was first evacuated for for at $70^{\circ}C$ and then treated for 10.5hr under hydrogen pressure of 20atm for $MmNi_{4.5}Mn_{0.5}$ alloy. The experimental data showed that the hydrogen storage alloy of $MmNi_{4.5}Mn_{0.5}$ had superior adsorption and description properties within a temperature rang of $40^{\circ}C{\sim}80^{\circ}C$ and also they had a good P-C-T curve.

• Korean Chemical Engineering Research
• /
• 제56권1호
• /
• pp.139-142
• /
• 2018

Silicon (Si) is a promising anode material for next-generation lithium ion batteries (LIBs) because of its high capacity of 4,200 mAh/g ($Li_{4.4}Si$ phase). However, the large volume expansion of Si during lithiation leads to electrical failure of electrode and rapid capacity decrease. Generally, a binder is homogeneously mixed with active materials to maintain electrical contact, so that Si needs a particular binding system due to its large volume expansion. Polyvinyl alcohol (PVA) is known to form a hydrogen bond with partially hydrolyzed silicon oxide layer on Si nanoparticles. However, the decrease of its cohesiveness followed by the repeated volume change of Si still remains unsolved. To overcome this problem, we have introduced the electrospinning method to weave active materials in a stable nanofibrous PVA structure, where stresses from the large volume change of Si can be contained. We have confirmed that the capacity retention of Si-based LIBs using electrospun PVA matrix is higher compared to the conservative method (only dissolving in the slurry); the $25^{th}$ cycle capacity retention ratio based on the $2^{nd}$ cycle was 37% for the electrode with electrospun PVA matrix, compared to 27% and 8% for the electrodes with PVdF and PVA binders.

• 한국미생물·생명공학회지
• /
• 제13권4호
• /
• pp.321-327
• /
• 1985

색소를 형성하지 못하는 Serratia sp. LW-1 균주의 균체의 protease생성조건을 검토하고 효소를 간단한 방법으로 정제하였다. 효소 생산을 위한 최적온도는 brain heart infusion배지에서 $25^{\circ}C$이었으며, 배양후 76-80시간에 최고의 균체의 효소활성을 나타냈다. Aeration효과는 5$\ell$용 flask에 배지량을 1$\ell$주입하여 180 cycles/min으로 진탕배양 하였을 때가 aeration하지 않았을 경우보다 약 8배의 균체의 효소생산을 보였다. 효소의 정 제는 ammonium sulfate침 전, ammonium sulfate분별염석 및 두번의 DEAE-cellulose column 크로마토그라피에 의하여 수행하였으며, 정제된 효소는 정제도가 약 100배, 회수율이 16%이었다. 정제된 효소는 analytical ultracentrifuge pattern에서 단일 단백질로 나타났으며 최고 활성을 나타내는 pH는 vitamin free casein을 substrate로 사용하였을 때 pH 8.5-9.5이었고 최적온도는 4$0^{\circ}C$ 근처이었다

• 한국응급구조학회지
• /
• 제23권1호
• /
• pp.61-69
• /
• 2019

Purpose: The study aims to provide basic data to enhance the health of paramedics responsible for patient transport and treatment by analyzing the exposure level of paramedics to electromagnetic waves generated by electric devices used in ambulances. Methods: The study measured electromagnetic waves in ambulances in N region from July to December 2018. ME3030B produced by German Gigahertz Solutions was used to measure these waves and the maximum value was selected by moving it slowly in various directions. Each measurement part was selected and the mean value was calculated by repeatedly measuring at 10-minute intervals three times in total: $1^{st}$, $2^{nd}$, and $3^{rd}$ phase. Results: Among the electrical devices installed in the patient room of the ambulance measured at distances of 1 cm or 30 cm, results showed a high level of electric waves at the inverter ($26.25{\pm}39V/m$) and high level of electromagnetic waves ($564.00{\pm}31.75nT$) at the ozone sterilizer. According to measurements toward the front near the driver's seat, results indicated high levels of electric waves ($3.67{\pm}1.15V/m$) and electromagnetic waves ($450.00{\pm}19.52nT$) at the black box hard drive. Conclusion: Electromagnetic waves within the ambulance were stable and not beyond the range that might impact human health. However, in the case of the black box hard drive ($3.67{\pm}1.15V/m$, $450.00{\pm}19.52nT$) located under the passenger seat, it may have a direct effect on the human body and, thus it is necessary to move it to a storage area further away from the paramedics to minimized the impact.

• International Journal of Internet, Broadcasting and Communication
• /
• 제13권1호
• /
• pp.47-53
• /
• 2021

Gait kinematics and kinetics have a similar tendency between men and women, yet it remains unclear how walking while carrying a load affects the gait mechanism. Twenty adults walked with preferred velocity on level ground of 20 m relative to change of a load carriage (no load, 15%, 30% of the body weights) aimed to observe gait mechanism. We measured gait posture using the three-dimensional image analysis and ground reaction force system during stance phase on left foot. In main effect of gender difference, men showed increased displacement of center of gravity (COG) compared to women, and it showed more extended joint angle of hip and knee in sagittal plane. In main effect of a load difference, knee joint showed more flexed postuel relative to increase of load carriage. In main effect of load difference on the kinetic variables, medial-lateral force, anterior-posterior force (1st breaking, 2nd propulsive), vertical force, center of pressure (COP) area, leg stiffness, and whole body stiffness showed more increased values relative to increase of load carriage. Also, men showed more increased COP area compared to women. Interaction showed in the 1st anterior-posterior force, and as a result of one-way variance analysis, it was found that a load main effect had a greater influence on the increase in the magnitude of the braking force than the gender. The data in this study explains that women require little kinematic alteration compared to men, while men in more stiff posture accommodate an added load compared to women during gait. Additionally, it suggests that dynamic stability is maintained by adopting different gait strategies relative to gender and load difference.

• Animal Bioscience
• /
• 제36권7호
• /
• pp.1059-1066
• /
• 2023

Objective: Present study was designed to evaluate the efficacy of Acacia nilotica bark extract as an alternative to antibiotic growth promoters in broilers. Methods: Six hundred, day-old broiler chicks were randomly divided into six groups (NC, without any supplementation; AB, NC+Zinc Bacitracin; PB, NC+Safmannan; ANBE1, NC+A. nilotica bark extract 0.1%; ANBE3, NC+A. nilotica bark extract 0.3%; ANBE5, NC+A. nilotica bark extract 0.5%), with ten replicates per group (10 chicks/replicate) and feeding trial was lasted for 35 days. Results: Results showed that weight gain (1,296.63 g) and feed conversion ratio (FCR, 1.59) of AB was better than NC, during the finisher phase. Overall FCR of AB (1.53), PB (1.54), and ANBE5 (1.54) was significantly (p<0.05) better than NC. From carcass parameters relative weight of wing and heart were highest in ANBE3 (2.5% and 1.51%, respectively). Significantly (p<0.05) highest blood glucose level was observed in NC (264.5 mg/dL) and highest albumin concentration was found in AB (1.46 mg/dL). In addition, antibody titer levels against ND and IBD were higher in ANBE5 than NC, while higher relative weight of bursa was observed in ANBE3 than NC. The villus height to crypt depth ratio in all experimental groups was better than NC. Conclusion: Acacia nilotica bark extract could be a suitable alternative to antibiotic growth promoters to support the growth in broilers.

• 한국결정성장학회:학술대회논문집
• /
• 한국결정성장학회 1996년도 제11차 KACG 학술발표회 Crystalline Particle Symposium (CPS)
• /
• pp.55-85
• /
• 1996

지르코니아 분말은 ZrO2 결정상이 온도변화에 따라 부피변화를 수반하는 상전이변태를 나타낸다. 단사정 ZrO2가 110$0^{\circ}C$에서는 정방정으로, 2$700^{\circ}C$ 내외에서는 입방정으로 결정구조가 가역적으로 변한다. 이 ZrO2에 금속산화물을 고용시키면 형석 (CaF2:Florite)형의 입방정 결정구조가 실온에서도 안정하게 존재하게 된다. 안정화제 산화물은 caO, MgO등 2가 산화물외에 3가 또는 4가의 금속산화물로서 Sc2O3, Y2O3, Sm2O3, Nd2O3, Gd2O3, Y2O3, CeO2 등이며 이들은 금속이온의 원자가가 변하기 쉬운 희토류 산화물이다. 안정화 지르코니아는 형석형 결정구조이며 결정화학적으로 보면 금속양이온이 산소이온에 대해서 정육면체형의 8배위를 하고 있다. 이때 이온반경비(양이온/음이온)에 따라 Zr+4자리와 O-2자리의 격자위치와 모양이 형성되므로 비틀어진 정육면체구조이건 이상적인 정육면체 형석구조를 이룬다. 이는 지르코니아의 결정상의 2상-3상인 부분안정화 지르코니아다결정체(PSZ : partially stabilized zirconia)이거나 단일상-2상인 정방정 지르코니아다결정체(TZP : tetragonal zirconia polycrystal)의 결정구조를 가지는데 기인한다. PSZ는 주로 MgO, CaO를 안정화제로 고용시켜 입방정 영역에서 소결하고 이를 다시 입방정과 정방정의 상 영역에서 열처리하여 입방정 입자내부에 정방정을 석출 형성시킨 것이며 TZP는 Y2O3 및 CeO2를 고용시켜 PSZ와 다르게 일반적인 상압소결한 정방정 결정상의 미립자이다. 산화지르코늄 분말은 지르콘사에서 열분해시킨 지르코늄소결.융해괴(caustic fusion clinker)를 산처리하여얻어진 지르코늄산용액(zirconyl acid solution : cloride, sulfide, nitride 등)으로부터 제조된다. 고순도 산화지르코늄은 용액 결정석출법에 의해 ZrOCl2.8H2O, 5ZrO2.3SO3.15H2O, ZrO(NO3)2.xH2O 등의 지르코늄 수화물만을 재결정화시킨 것으로부터 얻을 수 있으며 이 지르코늄염 수용액으로부터 입자미세구조를 효과적으로 제어하여 산화지르코늄 및 안정화 지르코니아 분말제조가 가능하다. 안정화 지르코니아 분말은 ZrO2와 안정화산화물의 고용을위하여 가열처리를 필요로 하며 일정온도에서 최적상태로 숙성하므로서 2가지 상(phase) 이상의 고용체를 가지게 된다. 안정화 지르코니아 분말은 고용처리온도를 낮추고 효과적으로 생성시키기 위해서는 지르코늄 및 안정화제염을 혼합하고 습식 직접합성하여 저온에서 고용체의 합해진상 영역을 생성시키는 것이다. 이는 지르코니아 원료분말의 미세구조를 제어하므로서 가능하며 이때 화학성분조성과 크기형태가 균일하게 분포된 입자분말을 얻을 수 있다.

• 한국식품영양과학회지
• /
• 제43권6호
• /
• pp.842-853
• /
• 2014

본 연구는 고올레산 해바라기유(high oleic sunflower oil, HOSO), palmitic ethyl ester 및 stearic ethyl ester를 이용하여 대칭형 유지와 비대칭형 유지를 합성하였으며, 이를 이용하여 in vitro digestion에서의 소화율(%)을 비교하고자 하였다. 생성된 대칭형 유지와 비대칭형 유지는 acetone을 이용하여 분별함으로써 대칭형 유지는 I, II, III으로, 비대칭형 유지는 IV, V로 분별되었다. 그 후 분별물들을 이용하여 in vitro digestion을 진행함으로써 소화율(%)과 농도변화량(mg/mL/min)을 비교하였으며, 분별물들의 위치별 지방산 및 TAG 조성 분석, DSC를 통한 흡열 및 발열곡선 분석, solid fat index와 융점 측정을 통해 특성을 알아보고자 하였다. 위치별 지방산 조성 분석 결과 I, II, III은 sn-2 위치에 palmitic acid와 stearic acid의 합이 4.9~6.5 area%로 나타나 주로 대칭형 TAG로 이루어졌고, IV와 V는 41.9~43.9 area%로 나타나 주로 비대칭형 TAG로 구성되어 있는 것으로 확인되었다. 한편 in vitro digestion을 진행하여 분별물간의 가수분해율(%)을 비교한 결과, 반응시간 120분에서는 V만 다른 분별물에 비해 약 40% 정도 소화가 되지 않았으며, V의 융점이 $49^{\circ}C$로 반응온도($37^{\circ}C$)보다 높았다. 초기 반응시간(15분)에서는 I,II>IV>III>V 순으로 소화가 되지 않았으며, 각 분별물에서 ${\bigcirc}{\bigcirc}{\bigcirc}$와 POS/PSO의 가수분해율(%)을 비교해 본 결과 TAG 간의 가수분해율 차이가 없는 것으로 나타났다. 한편 III과 IV를 비교해 보았을 때, IV가 III에 비해 두 개의 포화지방산으로 구성된 TAG 함량이 약 40 area% 적지만 complete melting point가 III과 유사한 것으로 나타나 비대칭형 TAG가 대칭형 TAG에 비해 융점이 높다는 것을 알 수 있었다. 따라서 slip melting point가 in vitro digestion 결과에 가장 큰 영향을 미치며, 융점은 총지방산 조성에서의 포화지방산 함량이 높을수록, 두 개의 포화지방산으로 구성된 TAG의 함량이 높을수록, 비대칭형 TAG로 이루어질수록 높아짐을 알 수 있었다.