• Title/Summary/Keyword: $Ni_2O_3$

Search Result 1,942, Processing Time 0.036 seconds

Microwave hybrid sintering of NTC themistor (마이크로파 하이브리드 소결법에 의한 NTC 서미스터의 제조)

  • 최영락;안진용;안주삼;백동규;최승철
    • Journal of the Korean Crystal Growth and Crystal Technology
    • /
    • v.8 no.3
    • /
    • pp.508-512
    • /
    • 1998
  • The NTC thermistors were sintered by using microwave hybrid heating method at $1100^{\circ}C$~$1300^{\circ}C$ and those electrical properties were investigated. The obtained $B_{25^{\circ}C/85^{\circ}C}$ values from temperature dependence of electrical resisitivity were around 3100~3200 K which were almost the same values as conventionally sintered ones. Compared with conventional sintering process, this process could complete whole sintering process within 20 minutes. This the processing time and energy consumption could be reduced through this rapid heating by using microwave hybrid heating.t there were showed only two peaks, glycolide melting peak and lower molecular weight melting peak without lauryl alcohol. Conversion increased slowly with the reaction time up to 50 minutes, and then gave a sudden increase above that. The reaction time to disappear in glycolide melting peak during polymerization was shortened with the increase of lauryl alcohol content. Zero-shear viscosity of polyglycolic acid decreased with the increase of free acid content in glycolide.ssional energy and bending hysteresis increased. \circled3 Surface characteristics such as friction coefficient and thickness variation of highly shrinkage fabrics became relatively roughened state. \circled4 Since stiffened and roughened characteristics of highly shrinkage fabrics, drapabilities of them were significantly lowered. Additionally thermal insulation property of high shrinkage fabric was higher than that of low shrinkage fabric due to bulky and thickened feature. From the results, it is considered that the silk fabrics with high filling shrinkage have the good bulkiness and heat keeping properties and thus they have the suitable characteristics for high quality men's and women's formal garments.

  • PDF

Changes in Chemical Properties of Paddy Field Soils as Influenced by Regional Topography in Jeonbuk Province (지형특성에 따른 전북지역 논토양 화학성 변화)

  • Ahn, Byung-Koo;Lee, Jin-Ho;Kim, Kab-Cheol;Kim, Hyung-Gook;Jeong, Seong-Soo;Jeon, Hye-Won;Zhang, Yong-Sun
    • Korean Journal of Soil Science and Fertilizer
    • /
    • v.45 no.3
    • /
    • pp.393-398
    • /
    • 2012
  • We investigated the changes in chemical properties of paddy field soils at 300 different sampling sites containing 4 topography in Jeonbuk province, Korea. The soil samples were collected 43.0% from local valley and fans, 39.3% from fluvio-marine deposits, 15.0% from alluvial plains, and 2.7% from diluvium sites. The optimal values of soil properties in the total soil samples were as follows: 65.3% of total samples in soil pH value, 48.3% of total samples in cation exchange capacity (CEC) value, and 22.3% of total samples in available phosphorus content, whereas the deficient values of soil properties were 63.3% of total samples in soil organic matter (SOM) content, 75.7% of total samples in available silicate content, and 61.3%, 51.0%, and 59.3% of total samples in exchangeable $K^+$, $Ca^{2+}$, and $Mg^{2+}$ concentrations, respectively. There were different soil types in the paddy fields: that is, 34.4% immature paddy and 33.6% sandy paddy in the local valley and fans, 57.8% sandy paddy in the alluvial plains, 47.4% normal paddy in the fluvio-marine deposits, and 75.7% immature paddy in the diluvium. Soil textures were also different: 53.5% loam in the local valley and fans, 37.8% sandy loam in the alluvial plains, and 55.1% silty loam in the fluvio-marine deposits. Soil pH and SOM contents were not different among the different topographical sampling sites. However, the mean value of available phosphorus content, 224 mg $kg^{-1}$, was exceeded optimal values in the diluvium. The contents of exchangeable cations were optimal in all the sites, except exchangeable $Ca^{2+}$ contents in the local valley and fans. The contents of available silicate ranged between 112 and 127 mg $kg^{-1}$ in all the sites, which were lower than optimal value. In addition, soil pH values were proportionally correlated to the order of available silicate, exchangeable $Ca^{2+}$, $Mg^{2+}$, $Na^+$, CEC, and exchangeable $K^+$. The contents of SOM were proportionally correlated to the order of CEC, available $P_2O_5$, exchangeable $Ca^{2+}$, and available silicate. The contents of heavy metals, Cd, Cr, Cu, Ni, Pb, and Zn, were only 10% of the threshold levels of the metals, and As content was about 20 to 30% of the threshold level.

Development of Particle-level Computer Assisted Instruction Materials for the ‘Solution’ Chapter in High School Chemistry Textbook and Analysis of the Educational Effects (고등학교 화학 교과서의 ‘용액’ 단원에 대한 입자 수준의 컴퓨터 보조 수업자료 개발 및 적용 효과 분석)

  • Baek, Seong-Hye;Kim, Jong-Hyeon;Kim, Jeong-Won;Park, Chan-Geun
    • Journal of the Korean Chemical Society
    • /
    • v.50 no.2
    • /
    • pp.163-177
    • /
    • 2006
  • Alpha Nickel hydroxide samples have been synthesized by electrodeposition on platinum and nickel substrates at current densities of 1, 5, 6, 7 and 10 mAcm?2 at a controlled temperature of 30.00 oC from Ni(NO3)2 bath. Platinum substrate shows a tendency to incorporate less nitrate ions with increase in current density thus producing less hydroxy-deficient nickel hydroxide layers. On the whole the interlayer distance (d003) is found to be inversely proportional to the amount of nitrate ions incorporated in-between the lattice. For the first time we have observed a decrease in lattice spacing with increase in concentration of intercalant (anions) and the reason for lattice contraction is attributed to the columbic attractive forces exerted by the oppositely charged nitrate ion and positively charged slabs. The Infrared spectra of the samples with expanded interlayers show two types of OH vibrations corresponding to hydrogen bonded and non-hydrogen bonded OH groups whereas the contracted interlayers show only hydrogen-boded OH groups. Although the faradaic efficiency is found to increase with increase in applied current there is a local minimum at 6.0 mAcm?2 current density on both platinum and nickel substrates. In this manuscript, GC-MS data is provided which clearly demonstrates the electrodeposited nickel hydroxide sample to consist of huge amount of carbonate ions although the electrolyte solution in nickel nitrate.

Ionic Dependence and Modulatory Factors of the Background Current Activated by Isoprenaline in Rabbit Ventricular Cells

  • Leem, Chae-Hun;Lee, Suk-Ho;So, In-Suk;Ho, Won-Kyung;Earm, Yung-E
    • The Korean Journal of Physiology
    • /
    • v.26 no.1
    • /
    • pp.15-25
    • /
    • 1992
  • In order to elucidate the properties of the background current whole cell patch clamp studies were performed in rabbit ventricular cells. Ramp pulses of ${\pm}80\;mV$ from holding potential of 40 mV(or 20 mV) at the speed of 0.8 V/sec were given every 30 sec(or 10 sec) and current-voltage diagrams(I-V curve) were obtained. For the activation of the background current isoprenaline, adenosine 3',5'-cyclic monophosphate(dBcAMP), guanosine 3',5'-cyclic monophosphate(cGMP), and $N^6$-2'-o-dibutyryladenosine 3',5'-cyclic monophosphate(dBcAMP) were applied after all known current systems were blocked with 2mM Ba, 1 mM Cd ,5 mM Ni, 10 ${\mu}M$ diltiazem, 10 ${\mu}m$ ouabain, and 20 mM tetraethylammonium(TEA). The conductance of background current in control was $0.65{\pm}0.69$ nS at 0 mV, its I-V curves was almost linear and reversed near 50 mV. When there was no taurine in pipette solution, isoprenaline hardly activated the background current but when taurine existed in pipette solution, isoprenaline activated the larger background current. Cyclic AMP or cyclic GMP alone had little effect on the activation of the background current, while cGMP potentiated cGMP effect. When the background current was activated with cGMP and cAMP, isoprenaline could not further increased the background current. The background current activated by isoprenaline depended on extracellular $Cl^-$ concentration and its reversal potential was shifted according to chloride equilibrium potential. The change of extracellular $Na+$ concentration had little effect on reversal potential of the background current activated by isoprenaline.

  • PDF

A Study of the Effect on Fertilization Condition on the Several Essential Elements in 2 Lettuce Cultivas (상치의 시비조건에 따른 상치내 몇 가지 미량원소의 함량에 관한 연구)

  • Kwon, O-Dal;Chung, Keun-Hi;Lee, Jin-Hi
    • Korean Journal of Organic Agriculture
    • /
    • v.7 no.1
    • /
    • pp.147-159
    • /
    • 1998
  • In order to study the effects of chemical fertilizer and organic fertilizer on the toxic mineral content in the absence or presence of the wood extraction, the lettuce an experiment of fatal 20 treatments was conducted far a peried of 10 weeks. The results obtained from the experiment are summarized as follows; 1. The mineral contents of the lettuce in the wood extraction-treated group and the wood extraction non-treated group showed no conspicious differenves. 2. These are no prominent differences in the mineal contents(Chromium, Nickel, Lead, and Aluminium) in the lettuce between the organic fertifized group and the lettuce raised in the chemical fertilized group. 3. Mercury was not detected in all samples of lettuces raised in all treatments.4. Cadmium contents in the lettuce samples were increased as the amount of organic fertilizer was increased from 25% to 100%.

  • PDF

A Study on the Nutrient Composition and Heavy Metal Contents in Livestock Manure Compost·Liquefied Fertilizer (가축분뇨 퇴비·액비의 비료성분 및 중금속 함량에 관한 연구)

  • Ahn, Taeung;Kim, Dongmin;Lee, Heungsoo;Shin, Hyunsang;Chung, Eugene
    • Journal of Korean Society on Water Environment
    • /
    • v.37 no.4
    • /
    • pp.306-314
    • /
    • 2021
  • The application of organic fertilizer could be accompanied by potential hazards to soil and humans due to trace metals. Livestock manure compost·liquefied fertilizer is a well-established approach for the stabilization of nutrients and the reduction of pathogens and odors in manures, which can be evaluated as compost·liquefied. In this study, the livestock manure compost·liquefied fertilizers produced at 333 liquid manure public resource centers and liquid fertilizer distribution centers were collected from May to December 2019. The nutrient content (nitrogen, phosphorus, and potassium), physicochemical properties, and heavy metal content were investigated. The livestock manure compost·liquefied fertilizer was measured using a mechanical maturity measurement device. The organic matter, arsenic, cadmium, mercury, lead, chromium, copper, nickel, zinc, E. coli (O157:H7), Salmonella, etc. of the livestock manure compost·liquefied fertilizers were analyzed. The average heavy metal content in the livestock manure compost·liquefied fertilizer was as follows: Cr 2.9 mg/kg (0.2~8.7 mg/kg), Cu 20.4 mg/kg (1.6~74.1 mg/kg), Ni 1.3 mg/kg (0.4~4.2 mg/kg), and Zn 79.8 mg/kg (3.0~340.7 mg/kg). Although large-scale organic fertilizer plants and resources recycling centers produce good organic (liquid) fertilizers with proper components, it is necessary to standardize livestock manure compost·liquefied fertilizer in order to facilitate efforts to turn livestock manure into useful resources.

Clinical Study on 1 Case of patient with Urinary Retention (요폐환자(尿閉患者) 1례(例)에 대한 임상적(臨床的) 고찰(考察))

  • Kim, Jae-Hyeng;Cho, Chung-Sik;Kim, Chul-Jung
    • Journal of Haehwa Medicine
    • /
    • v.14 no.1
    • /
    • pp.43-49
    • /
    • 2005
  • One case of patient with urinary retention was reported in this clinical study. After the study, the results were as follows: 1. Anulesis belongs to l$\acute{o}$ng-bi(癃閉) in oriental medicine and the patient of this case belongs to chronic anulesis. 2. The patient of this case was thought as broke out anuresis by vesical nerve palsy of diabetic bladder pathy and sequela of stroke, and ischuria of long lie down 3. The patient of this case changeable process is supposed to urinary frequency, 'bi(閉)', 'l$\acute{o}$ong(癃)', urinary incontinence and urinary frequency. 4. First time of drug treatment is GAMIPHALJENG-SAN(ji$\bar{a}$-w$\grave{e}$i-b$\bar{a}$-h$\bar{e}$ng-s$\check{a}$n) by oral administration that action of alleviate a fever, water utilization and metaphase, convalescence time of drug treatment is PHALMIWANGAMI (b$\bar{a}$-w$\grave{e}$i-w$\acute{a}$n-ji$\bar{a}$-w$\grave{e}$i), YIKLUENG-TANG(yi-ling-t$\bar{a}$ng), CHUKYOO-TANG(s$\grave{u}$-ni$\grave{a}$o-t$\bar{a}$ng) that action of recreation. 5. Accupuncture treatment is s$\bar{a}$n-x$\bar{i}$ng-xuw$\acute{e}$, zw$\acute{u}$-s$\bar{a}$n-li, qi-h$\check{a}$i, gu$\bar{a}$n-yu$\acute{a}$n, zh$\bar{o}$ng-ji by mild supplementing and reducing manipulation of needle and heat accupuncture is qi-h$\check{a}$i, gu$\bar{a}$n-yu$\acute{a}$n, zh$\bar{o}$ng-ji-xu$\acute{e}$. 6. The other treatment is a sitz bath that prevent of urinary tract infection, and relieve of initial acute auresis by using of urethral catheterization.

  • PDF

Chemical Components and Physiological Activities of Bamboo (Phyllostachys bambusoides Starf) Extracts Prepared with Different Methods (추출방법에 따른 대나무(왕대) 추출물의 화학성분 및 생리활성)

  • Ju, In-Ok;Jung, Gi-Tai;Ryu, Jeong;Choi, Joung-Sik;Choi, Yeong-Geun
    • Korean Journal of Food Science and Technology
    • /
    • v.37 no.4
    • /
    • pp.542-548
    • /
    • 2005
  • Chemical components and physiological activities Bamboo (Phyllostachys bambusoides Starf) extracts obtained by burning, dry heating or extracting with water or 70% ethanol and were investigated. Contents of soluble solid and total phenolic compounds were highest in the ethanol extract. Contents of polyphenols such as catechin, chlorogenic acid, caffeic acid, 3-hydroxy benzoic acid and ferulic acid were determined. Free sugars consisted of galactose, glucose, fructose, and sucrose. Organic acids including citric, tartaric, malic, succinic, and acetic acid were present in the bamboo extracts. Antioxidant activities of dry heat and ethanol extracts were higher than those of BHA or ${\delta}-tocopherol$. Nitrite- scavenging effect of extracts ranged from 84.7 to 99.6% at pH 1.2 ana 3.0. Tyrosinase-inhibitory activity was higher in the water extract, and SOD-like and ACE-inhibitory activity were highest in tile dry kent extract. Antimicrobial activities of the bamboo extracts were strong against Bacillus subtilis, Escherichia coli O157, and Staphylococcus aureus.

Direct Imaging of Polarization-induced Charge Distribution and Domain Switching using TEM

  • O, Sang-Ho
    • Proceedings of the Korean Vacuum Society Conference
    • /
    • 2013.08a
    • /
    • pp.99-99
    • /
    • 2013
  • In this talk, I will present two research works in progress, which are: i) mapping of piezoelectric polarization and associated charge density distribution in the heteroepitaxial InGaN/GaN multi-quantum well (MQW) structure of a light emitting diode (LED) by using inline electron holography and ii) in-situ observation of the polarization switching process of an ferroelectric Pb(Zr1-x,Tix)O3 (PZT) thin film capacitor under an applied electric field in transmission electron microscope (TEM). In the first part, I will show that strain as well as total charge density distributions can be mapped quantitatively across all the functional layers constituting a LED, including n-type GaN, InGaN/GaN MQWs, and p-type GaN with sub-nm spatial resolution (~0.8 nm) by using inline electron holography. The experimentally obtained strain maps were verified by comparison with finite element method simulations and confirmed that not only InGaN QWs (2.5 nm in thickness) but also GaN QBs (10 nm in thickness) in the MQW structure are strained complementary to accommodate the lattice misfit strain. Because of this complementary strain of GaN QBs, the strain gradient and also (piezoelectric) polarization gradient across the MQW changes more steeply than expected, resulting in more polarization charge density at the MQW interfaces than the typically expected value from the spontaneous polarization mismatch alone. By quantitative and comparative analysis of the total charge density map with the polarization charge map, we can clarify what extent of the polarization charges are compensated by the electrons supplied from the n-doped GaN QBs. Comparison with the simulated energy band diagrams with various screening parameters show that only 60% of the net polarization charges are compensated by the electrons from the GaN QBs, which results in the internal field of ~2.0 MV cm-1 across each pair of GaN/InGaN of the MQW structure. In the second part of my talk, I will present in-situ observations of the polarization switching process of a planar Ni/PZT/SrRuO3 capacitor using TEM. We observed the preferential, but asymmetric, nucleation and forward growth of switched c-domains at the PZT/electrode interfaces arising from the built-in electric field beneath each interface. The subsequent sideways growth was inhibited by the depolarization field due to the imperfect charge compensation at the counter electrode and preexisting a-domain walls, leading to asymmetric switching. It was found that the preexisting a-domains split into fine a- and c-domains constituting a $90^{\circ}$ stripe domain pattern during the $180^{\circ}$ polarization switching process, revealing that these domains also actively participated in the out-of-plane polarization switching. The real-time observations uncovered the origin of the switching asymmetry and further clarified the importance of charged domain walls and the interfaces with electrodes in the ferroelectric switching processes.

  • PDF

Preparation of Poly(propylene) Membrane Supported Gel Electrolyte Membranes for Rechargeable Lithium Ion Batteries through Thermal Polymerization of Di(ethylene glycol) Dimethacrylate (Di(ethylene glycol) Dimethacrylate의 열중합에 의한 Poly(propylene) 분리막으로 지지한 리튬이온 이차전지의 겔 전해질막 제조)

  • Yun, Mi-Hye;Kwon, So-Young;Jung, Yoo-Young;Cho, Doo-Hyun;Koo, Ja-Kyung
    • Membrane Journal
    • /
    • v.20 no.3
    • /
    • pp.259-266
    • /
    • 2010
  • Porous poly(propylene) supported gel polymer electrolytes (GPE) were synthesized by thermal polymerization of DEGDMA [Di(ethylene glycol) dimethacrylate] in electrolyte solutions (1 M solution of $LiPF_6$ in EC/DEC 1 : 1 mixture) at $70^{\circ}C$. AC impedance spectroscopy and cyclic voltammetry were used to evaluate its ionic conductivity and electrochemical stability window of the GPE membranes. Lithium ion battery (LIB) cells were also fabricated with $LiNi_{0.8}Co_{0.2}O_2$/graphite and GPE membranes via thermal polymerization process. Through the thermal polymerization, self sustaining GPE membranes with sufficient ionic conductivities (over $10^{-3}\;S/cm$) and electrochemical stabilities. The LIB cell with 5% monomer showed the best rate-capability and cycleability.