• Particle and aerosol research
• /
• v.13 no.1
• /
• pp.33-40
• /
• 2017

Cobalt-iron oxides have emerged as alternative electrode materials for supercapacitors because they have advantages of low cost, natural abundance, and environmental friendliness. Graphene loaded with cobalt ferrite ($CoFe_2O_4$) nanoparticles can exhibit enhanced specific capacitance. In this study, we present three-dimensional (3D) crumpled graphene (CGR) decorated with $CoFe_2O_4$ nanoparticles. The $CoFe_2O_4$-graphene composites were synthesized from a colloidal mixture of GO, iron (III) chloride hexahydrate ($FeCl_3{\cdot}6H_2O$) and cobalt chloride hexahydrate ($CoCl_2{\cdot}6H_2O$) respectively, via one step aerosol spray pyrolysis. Size of $CoFe_2O_4$ nanoparticles was ranged from 5 nm to 10 nm when loaded onto 500 nm CGR. The electrochemical performance of the $CoFe_2O_4$-graphene composites was examined. The $CoFe_2O_4$-graphene composite electrode showed the specific capacitance of $253F\;g^{-1}$.

• Journal of Sport and Applied Science
• /
• v.7 no.3
• /
• pp.19-26
• /
• 2023

Purpose: This study attempted to investigate the effect of functional rehabilitation exercise for posture correction on physical strength factors and physical balance. Research design, data, and methodology: It consisted of 40 experimental groups that applied functional rehabilitation exercises to 80 people with posture imbalance and 40 comparative groups that performed general exercises, and was conducted four times a week, once for 40 minutes, and for 12 weeks. Results: D.S. (p<.o1) among F.M.S., a moving assessment. It increased significantly from the dictionary, and H.S. (p<.o5). I.L(p<.o5). S.M(p<.o5). A.S.L.R(p<.o5). T.S.P(p<.o01). It was confirmed that R.S. (p<.o5) decreased more after than before. In other words, Functional rehabilitation exercise was effective in improving physical balance. PAPS flexibility (bending forward) (p<.o1). Muscle strength (grip strength test) (p<.o1). Quickness (long jump) (p<.o1). Functional rehabilitation exercise was found to be effective in muscle strength, agility, and flexibility, but not in cardiopulmonary endurance. Pain: Based on the NRS scale (1-10 points). The experimental that there was a significant interaction between the groups.(F=38.583, P=.000). In the comparative group, there was no significant difference in the pre-post, and it was found that the pain level in the experimental group decreased after the pre-post (p<.001). Conclusion: As a result of the above study, it was confirmed that functional rehabilitation exercise improves physical strength factors and physical balance ability, and also affects physical pain reduction due to physical imbalance.

• Journal of the Korean Ceramic Society
• /
• v.48 no.5
• /
• pp.447-453
• /
• 2011

The monodisperse spherical $SiO_2$ particles were overcoated with $Y_2O_3:Eu^{3+}$ phosphor layers via a Pechini sol-gel process and the resulting $SiO_2@Y_2O_3:Eu^{3+}$ core-shell phosphors were subsequently annealed at $800^{\circ}C$ at an ambient atmosphere. The crystallographic structure, morphology, and luminescent property of core-shell structured $SiO_2@Y_2O_3:Eu^{3+}$ phosphors were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), and photoluminescence (PL). The spherical, nonagglomerated $SiO_2$ particles prepared by a Stober method exhibited a relatively narrow size distribution in the range of 260-300 nm. The thickness of phosphor shell layer in the core-shell particles can be facilely controlled by varying the coating number of $Y_2O_3:Eu^{3+}$ phosphors. The core-shell structured $SiO_2@Y_2O_3:Eu^{3+}$ phosphors showed a strong red emission, which was dominated by the $^5D_0-^7F_2$ transition (610 nm) of $Eu^{3+}$ ion under the ultraviolet excitation (263 nm). The PL emission properties of $SiO_2@Y_2O_3:Eu^{3+}$ phosphors were also compared with pure $Y_2O_3:Eu^{3+}$ nanophosphors.

• Journal of the Korean Magnetic Resonance Society
• /
• v.11 no.2
• /
• pp.95-109
• /
• 2007

Vanadium-incorporated aluminophosphate microporous molecular sieve VH-SAPO-42 has been studied by electron spin resonance(ESR) and electron spin-echo modulation (ESEM) spectroscopies to determine the vanadium location and interaction with various adsorbate molecules. The results are interpreted in terms of V(IV) ion location and coordination geometry. Assynthesized VH-SAPO-42 contains only vanadyl species with distorted octahedral or trigonal bipyramidal coordination. Vanadium incorporated into H-SAPO-42 occupied extra-framework site. After calcinations in $O_2$ and exposure to moisture, only species A is observed with reduced intensities. Species A is identified as a $VO(H_2O)_2^{2+}$ complex coordinated to three framework oxygen atoms bonded to aluminum. When hydrated VH-SAPO-42 is dehydrated at elevated temperature by calcination, species A loses its water ligand and transforms to $VO^{2+}$ ions coordinated to three framework oxygens (species B). Species B reduces its intensities significantly after treatment with $O_2$ at high temperature, thus suggesting oxidation of $V^{4+}$ to $V^{5+}$. When dehydrated VH-SAPO-42 makes contact with $D_2O$ at room temperature, the ESR signal of species A is regained. The species is assumed as a $VO(O_f)_3(D_2O)_2$ by considering three framework oxygens. Adsorption of deuterated methanol on dehydrated VH-SAPO-42 results in another new vanadium species D, which is identified as a $VO(CD_3OH)_2$ complex. When deuterated ethylene is adsorbed on dehydrated VH-SAPO-42, another new vanadium species E identified as a $VO(C_2D_4)^{2+}$, is observed. Possible coordination geometries of these various complexes are discussed.

• Archives of Pharmacal Research
• /
• v.12 no.3
• /
• pp.181-185
• /
• 1989

When 3-acetyl coumarin derivatives are treated with bromine, 3-(w-bromoacetyl) coumarin derivatives are obtained. The reaction of 3-(w-bromoacetyl)coumarin derivatives with thiourea or with amines for two hours leads to the formation of 2-Amino-4-(3-coumarinyl) thiazole or 3-(w-aminoacetyl) coumarin derivatives, respectively. While 3-(w-bromoacetyl) coumarin derivatives react with amines for 5-8 hours to yield imino derivatives of 3-(w-aminoacetyl) coumarin. The antimicrobial activity of Ia-b, IIa-c, IVc-f, IVh and V$_{c}$, f, h, k, m, and q was studied.d.

• Journal of Korean Society of Water and Wastewater
• /
• v.32 no.1
• /
• pp.19-25
• /
• 2018

The objectives of this study were to evaluate the removal characteristics of total nitrogen, the influence factor of denitrification and the optimum operating condition in the pigment wastewater treatment using PAC-A/O process. The operating conditions of PAC-A/O process were mean BOD volumetric loading $0.86kgBOD/m^3/day$, mean F/M ratio 0.072~0.13 kgBOD/kgMLVSS/day and mean C/N ratio 3.47, respectively. The conditions of anoxic process in the field plant test were mean pH 8.3~8.7 and mean temperature $34.1{\sim}44.0^{\circ}C$. The ORP bending point knee was eventually appeared in the ORP -107 mV and $NO_3{^-}-N$ removal efficiency was increased according to the ORP decrease. In the ORP -107 mV below condition, the removal efficiency of T-N and $NO_3{^-}-N$ was 92.3~95.0% and 98.5~99.7%. Denitrification rate was calculated to be 1.581~1.791 mg $NO_3{^-}-N/gMLSS/hr$. The experimental results showed that the ORP control in the PAC-A/O process could be an effective method for treatment of pigment wastewater.

• Korean Journal of Agricultural Science
• /
• v.12 no.1
• /
• pp.108-117
• /
• 1985

The process of conveying of soil with the open auger to cover the seed completly with less power was reviewed by theoretical analysis. The power efficiency, the reasonable range of RPM of the open auger and the velocity of soil conveying to the direction of the shaft are examined to establish the extent of characteristics of the open auger performance. The results of theoretical analysis and application of similitude are as follows: 1. It is possible to predict the power efficiency by the following equation; ${\eta}_p={\frac{P_n}{P_g}}=({\frac{{\omega}_s}{{\omega}_a}}){\cdot}tan{\gamma}{\frac{mg}{(F_mcos{\alpha}+F_scos{\gamma})}}$ 2. The reasonable range of the revolutions per minute of the open auger was presented as follow to cover completely with less power ; $$\frac{4d(L_a-L_i){\cdot}V_w}{{\pi}(D_o^2-D_s^2){\cdot}r{\cdot}{\frac{{\omega}_s}{{\omega}_a}}{\cdot}tan{\gamma}}{{\leq_-}}{\omega}_a{{\leq_-}}({\frac{{\omega}_a}{{\omega}_s}}){\sqrt{\frac{g}{r}}}$$ 3. The velocity of soil conveying to the direction of the auger shaft may be calculated by the equation; $V_h=({\frac{{\omega}_s}{{\omega}_s}})V_a{\cdot}tan{\gamma}$ 4. The factor of RPM was more important than other factors on the power efficiency.

• Journal of Plant Biotechnology
• /
• v.38 no.1
• /
• pp.22-29
• /
• 2011

Although reactive oxygen species (ROS) are inevitable by-products of many redox reactions in eukaryotic cells, they play a crucial role as signaling molecules in many cellular processes for development and defense response to abiotic stresses. The biphasic ROS production which was peaked twice in a first transient phase and a second massive phase was occurred after treatment of abiotic stress such as oxidative stress, high salinity. This biphasic generation of ROS was followed by the biphasic production of stress hormone, ethylene. The mechanism of interactions between ROS and ethylene biosynthesis is studied in tobacco (Nicotiana tabaccum L.) plants under the abiotic stresses. The stress-induced ethylene production was significantly inhibited in RbohD-AS and RbohF-AS, in which antisense expression of NADPH oxidase genes was performed. The accumulation of ROS, which was determined by DAB and DCFH-DA staining, was significantly decreased after abiotic stresses in transgenic plants. The suppression of signaling with ethylene and ROS induced more tolerance in response to abiotic stress. The transgenic plants were more tolerant in MS medium supplemented with salinity stress in contrast with wild-type. Stress-induced cell damage determined by DNA fragmentation was decreased at phase II in those transgenic plants. Therefore, the first burst of ROS is more responsible for making a role as a signaling molecule during stress-induced response. These results suggested that ethylene and ROS act in a positive feedback cycle that results in mutual enhancement of ethylene and ROS production during stress-induced cell death.

• The Journal of the Petrological Society of Korea
• /
• v.6 no.3
• /
• pp.166-184
• /
• 1997

The Wondong caldea is a deeply eroded structure that offers spectacular exposures through the core and margins of a resurgent caldera. The Wondong Tuff and the postcollapse intrusions range from medium-silica rhyolite to rhyodacite in composition and the postcollapse lava and tuff, preresurgent and resurgent intrusions also range from medium-silica rhyolite to an-desite, which jump to gap dacite composition. The continuous compositional zonations generally define a large stratified magma system in the postcollapse and resurgent magma chamber. Isotopic and trace element evidence suggest that the compositional zonations might have resulted from the differentiations from crystal fractionations of a parental andesitic magma, accompanying a little contamination from the crustal assimilations near the chamber roof and wall. But chemically and isotopically distinct late intusions might have resulted from emplacement of any different magma batch.

• Korean Journal of Pharmacognosy
• /
• v.16 no.4
• /
• pp.233-238
• /
• 1985

A number of sedative alkaloids were isolated from Sanjoin(酸棗仁), the seeds of Zizyphus vulgaris Lamark var. spinosus Bunge (Rhamnaceae) which is an important Chinese medicinal material used to treat insomnia and sometimes to treat sleepiness. Those compounds were designated as Sanjoinine-A, B, C, D, etc. depending on the order of increasing polarity. Sanjoinine-A, $C_{31}H_{42}N_4O_4$, $mp\;249^{\circ}$, $[{\alpha}]^{27}_D-316$, Sanjoinine-B, $C_{30}H_{40}N_4O_4$, $mp\;212{\sim}4^{\circ}$, Sanjoinene, $C_{29}H_{35}N_3O_4$, $mp\;281{\sim}2^{\circ}$, $[{\alpha}]^{22}_D-272$, Sanjoinine-D, $C_{32}H_{46}N_4O_5$, $mp\;256{\sim}8^{\circ}$, $[{\alpha}]^{22}_D-53.6$, Sanjoinine-F, $C_{31}H_{42}N_4O_5$, $mp\;228{\sim}9^{\circ}$, $[{\alpha}]^{22}_D-215$, and $Sanjoinine-G_1,\;C_{31}H_{44}N_4O_5,\;mp\;236{\sim}8^{\circ},\;[{\alpha}]^{22}_D-68.6$, were found as 14-membered cyclic peptide alkaloids, $Sanjoinine-G_2,\;C_{30}H_{42}N_4O_4,\;mp\;182^{\circ},\;[{\alpha}]^{22}_D-79.2$, as being open chain peptide alkaloid, and Sanjoinine-E, $C_{19}H_{21}NO_2$, $mp\;166^{\circ}$, $[{\alpha}]^{20}_D-146.2$, N-Methylasimilobine, $C_{18}H_{19}NO_2$, $mp\;193{\sim}5^{\circ}$, $[{\alpha}]^{20}_D-204$, Sanjoinine-Ia, $C_{18}H_{19}NO_2$, $mp\;155{\sim}7^{\circ}$, $[{\alpha}]^{20}_D-140$, Sanjoinine-Ib, $C_{19}H_{21}NO_4$, $mp\;184^{\circ}$, Sanjoinine-K, $C_{16}H_{19}NO_3$, $mp\;159{\sim}61^{\circ}$, $[{\alpha}]^{20}_D+35$, Caaverine, $C_{17}H_{17}NO_2$, $mp\;204^{\circ}$, $[{\alpha}]^{20}_D-80$, and Zizyphusine, $C_{20}H_{24}NO_4$, $mp\;214{\sim}6^{\circ}$, $[{\alpha}]^{20}_D+317$ as being aporphine alkaloids. The heat treatment of the cyclic peptide alkaloids produced their isomeric products which showed enhanced sedative activity. The chemical structure of the isomeric products will be discussed.