• Bulletin of the Korean Chemical Society
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• v.23 no.12
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• pp.1744-1748
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• 2002

Trifluoroacetate anion as a connector has been studied on $AgCF_3CO_2$ with 3,3'-$Py_2X$(X=O vs S) produces 1 : 1 adducts of [Ag($CF_3CO_2$)(3,3'-$Py_2X<$)]. Crystallographic characterization of [Ag($CF_3CO_2$)(3,3'-$Py_2X$)](monoclinic $P2_1$a=7.383(1)$\AA$b=19.801(3)$\AA$c=9.297(3)$\AA$,$\beta$=$100.26(2)^{\circ}$,V=1337.4(5) $\AA^3$, Z=2, R=0.0386) reveals that the 3,3'-$Py_2O$ spacer connects two silver ions to give a single strand and that the single strands are linked via the trifluoroacetate anions in an "up and down even-bridge" to give an elegant molecular grid. The framework of [$Ag(CF_3CO_2)(3,3'-Py_2X)$](monoclinic $P2_1/c$a=8.331(2)$\AA$b=14.010(2)$\AA$,c=11.926(3 $\AA$$\beta$=$93.70(2)^{\circ}$=1385.1(6)$\AA^3$, Z=4, R=0.0589) is a single-strand. The single strands are connected via the trifluoroacetate anions in a double-bridge, resulting in a typical molecular chicken-wire. The trifluoroacetate anion as a connector appears to be primarily associated with its moderately coordinating ability. Their structural features have been discussed based on the anion exchangeability. Thermal analyses indicate that the compounds are stable up to approximately $200^{\circ}C$.

• Journal of Science Education
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• v.45 no.2
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• pp.219-230
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• 2021

In this study, we derived several formulas for magnetic fields and induced voltages in a parallel plate capacitor biased by DC voltages. The computer simulation based on the derived formulas reveals that the magnetic fields due to the displacement current fall within the range of 10^-10T to 10^-9T and thence the experiment for the displacement current is not possible because the magnetic field sensor used in Data Logger could measure the magnetic fields of above 10^-5T range. Contrary to this, the computer simulation confirms that the induced voltages in a toroidal coil due to the displacement current range measurable values of 0.002~0.021V. The results imply that the displacement current can be confirmed by measuring the induced voltages in a toroidal coil inserted into a parallel plate capacitor under DC biasing.

• Journal of radiological science and technology
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• v.21 no.2
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• pp.36-42
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• 1998

Treatment of a large diseased area with electron often requires the use of two or more adjoining fields. In such cases, not only electron beam divergence and lateral scattering but also fields overlapping and separation may lead to significant dose inhomogeneities(${\pm}20%$) at the region of junction of fields. In this study, we made Acrylic Electron Wedges to improve dose inhomogeneities(${\pm}5%$) in these junction areas and to apply it to clinical practices. All measurements were made using 6, 9, 12, 16, 20 MeV Electron beams from a linear accelerator for a $10{\times}10\;cm$ field at 100cm of SSD. Adding a 1 mm sheet of acryl gradually from 1 mm to 15 mm acquires central axis depth dose beam profile and isodose curves in water phantom. As a result, for all energies, the practical range was reduced by approximately the same distance according to the acryl insert, e.g. a 1 mm thick acryl insert reduces the practical range by approximately 1 mm. For every mm thickness of acryl inserted, the beam energy was reduced to approximately 0.2 MeV. These effects were almost Independent of beam energy and field size. The use of Acrylic Electron Wedges produced a small increase(less than 3%) in the surface dose and a small increase(less than 1%) in X-ray contamination. For acryl inserts, thickness of 3 mm or greater, the penumbra width increased nearly linear for all energies and isodose curves near the beam edge were nearly parallel with the incident beam direction at the point of penumbra width($35\;mm{\sim}40\;mm$). We decide heel thickness and angle of the wedge at this point. These data provide the information necessary to design Acrylic Electron Wedge which can be used to improve dose uniformity at electron field junctions and it will be effectively applied to clinical practices.

• Korean Journal of Food Science and Technology
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• v.43 no.4
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• pp.513-517
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• 2011

The effects of nonthermal plasma treatments against Salmonella Typhimurium, Escherichia coli O157:H7, and Listeria monocytogenes living on polystyrene (PS), sausage casings, and smoked salmon were investigated. Inoculated PS, casings, and salmon were treated with nonthermal plasma generated with helium (5 L/min) or with both helium (5 L/min) and oxygen (100 mL/min) at 60 Hz and 30 kV/cm for 2, 5, or 10 min. S. Typhimurium exhibited the highest sensitivity to the helium-used treatment. The greatest reduction (3.9${\pm}$0.8 log$CFU/cm^2$) was observed with L. monocytogenes on PS after the treatment with the mixed gas for 5 min. The treatment with the mixed gas inhibited L. monocytogenes on casings and salmon by 0.5${\pm}$0.3 log$CFU/cm^2$ and 1.0${\pm}$0.3 log CFU/g, respectively. Different treatment times did not result in different reductions of L. monocytogenes on both casings and salmon. The types of treatment gas and material of contamination need to be considered for evaluating the antimicrobial effects of nonthermal plasma treatments.

• Journal of the Mineralogical Society of Korea
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• v.16 no.4
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• pp.307-320
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• 2003

Garnet has been considered as a possible matrix for the immobilization of radioactive actinides. It is expected that Fe­based garnet be able to have the high substitution ability of actinide elements because ionic radius of Fe in tetrahedral site is larger than that of Si of Si­based garnet. Accordingly, we synthesized Fe­garnet with the batch composition of $Ca_{2,5}$C $e_{0.5}$Z $r_2$F $e_3$ $O_{12}$ and $Ca_2$CeZrFeF $e_3$ $O_{12}$ and studied their phase relations and properties. Mixed samples were fabricated in pellet forms under the pressure of 400 kg/$\textrm{cm}^2$ and were sintered in the temperature range of 1100∼140$0^{\circ}C$ in atmospheric conditions. Phase identification and chemical composition of synthesized samples were analyzed by XRD and SEM/EDS. In results, where the compounds were sintered at 130$0^{\circ}C$, we optimally obtained Fe­garnets as the main phase, even though some minor phases like perovskite were included. The compositions of Fe­garnets synthesized from the batch compositions of $Ca_{2,5}$C $e_{0.5}$Z $r_2$F $e_3$ $O_{12}$ and $Ca_2$CeZrFeF $e_3$ $O_{12}$, are $Ca_{2.5­3.2}$C $e_{0.3­0.7}$Z $r_{1.8­2.8}$F $e_{1.9­3.2}$ $O_{12}$ and $Ca_{2.2­2.5}$C $e_{0.8­1.0}$Z $r_{1.3­1.6}$ F $e_{0.4­.07}$ F $e_{3­3.2}$ $O_{12}$, respectively. Ca contents were exceeded and Ce contents were exceeded or depleted in 8­coodinated site, comparing to the initial batch composition. These results were caused by the compensation of the difference of ionic radius between Ca and Ce.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.52 no.6
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• pp.587-595
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• 2019

Eighty-three Vibrio parahaemolyticus isolates from surface seawater in Gomso Bay on the west coast of Korea, and commercial fisheries from Gunsan fisheries center were analyzed for the presence of virulence genes and susceptibility to 30 different antimicrobials. All 83 isolates were examined for the presence of two virulence genes (tdh or trh) using polymerase chain reaction; however, neither gene was found in any of the isolates. A disk diffusion susceptibility test, showed that all of the strains studied were resistant to clindamycin, oxacillin, ticarcillin, and vancomycin, and also revealed varying levels of resistance to ampicillin (98.8%), penicillin G (95.2%), streptomycin (20.5%), cefoxitin (14.5%), amikacin (6.0%), cephalothin (4.8%), and erythromycin (3.6%). However, all of the strains were susceptible to 19 other antimicrobial agents, including cefepime, cefotaxime, chloramphenicol, gentamycin, nalidixic acid, sulfamethoxazole/trimethoprim, and trimethoprim. All 83 isolates (100%) were resistant to five or more classes of antimicrobials, and two strains exhibited resistance to ten antimicrobial agents. The average minimum inhibitory concentrations against V. parahaemolyticus of clindamycin, oxacillin, ticarcillin, and vancomycin were 55.9, 98.3, 499.3, and 44.3 ㎍/mL, respectively. These results provide new insight into the necessity for seawater sanitation in Gomso Bay and commercial fisheries, and provide evidence to help reduce the risk of contamination by antimicrobial-resistant bacteria.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2016.11a
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• pp.117-117
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• 2016

Total ankle replacement (TAR) is a visible option in the surgical treatment of degenerative or inflammatory diseases of ankle joint. it is attributed to the current TAR which has improvements in surgical technique, uncemented implant fixation and minimally constrained articulation. In the clinical result, they can show promised surgical result when compared to earlier attempts in TAR. However, TAR is still not as successful as total knee replacement (TKR) or total hip replacement (THR), it needs to be note that there are limitations in concerning of long term performance of TAR, the high failure rate still associated with wear of the PE (polyethylene) component that has related with their material property and surface roughness. The aim of this study was to introduce the tribology characteristics of total ankle joint prosthesis with one of TDR model which was fabricated to try multi-axis wear test as a region of motion in ankle joint. The wear specimen of TDR was prepared with Ti-6Al-4V alloy and UHMWPE (ultra-high molecular weight polyethylene) for tibia-talus and bearing component, respectively. A wear test was carried out using a Force 5 (AMTI, Massachusetts, US) wear simulator which can be allowed to move in three axis to flexion-extension ($+3^{\circ}{\sim}-6^{\circ}$), internal-external axial rotation (${\pm}5^{\circ}$), as well as sinusoidal compressive load (1.6 kN, R=10). All tests were performed following standard ISO 14243, wear rate was calculated with weight loss of UHMWPE bearing while the specimen has tested at certain cycles. As based on the preliminary results, wear rate of UHMWPE bearing was $7.9{\times}10^{-6}mg/cycles$ ($R^2=0.86$), calculated loss weight until $10^7cycles$ was 79 mg, respectively.

• Earthquakes and Structures
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• v.26 no.5
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• pp.349-361
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• 2024

Excessive torsional behaviour is one of the major reasons for failure of buildings, as inferred from past earthquakes. Numerous seismic codes across the world specify a displacement-based or drift-based criterion for classifying buildings as torsionally irregular. In recent years, quite a few researchers have pointed out some of the inherent deficiencies associated with the current codal guidelines on torsional irregularity. This short communication paper aims to envisage the need for a revision of the displacement-based guidelines on torsional irregularity, and further highlight the appropriateness of a rotation-based criterion. A set of 6 reinforced concrete building models with asymmetric shear walls are analysed using ETABS v18.0.2, by varying the number of stories from 1 to 9, and the torsional irregularity coefficient of various stories is calculated using the displacement-based formula. Since rotation about the vertical axis is a direct indication of the twist experienced by a building, the calculated torsional irregularity coefficients of all stories are compared with the corresponding floor rotations. The conflicting results obtained for the torsional irregularity coefficients are projected through five categories, namely mismatch with floor rotations, inconsistency in trend, lack of clarity in incorporation of negative values, sensitivity to low values of displacement and error conceived in the mathematical formulation. The findings indicate that the irregularity coefficient does not accurately represent the torsional behaviour of buildings in a realistic sense. The Indian seismic code-based values of 1.2 and 1.4, which are used to characterize buildings as torsionally irregular are observed to be highly sensitive to the numerical values of displacements, rather than the actual degree of rotation. The study thus emphasizes the revision of current guidelines based on a more relevant rotation-based or eccentricity-based approach.

• The Korean Journal of Physiology
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• v.18 no.1
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• pp.19-35
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• 1984

Since the first report of Drury and $Szent-Gy{\ddot{o}}rgyi$ in 1929, the inhibitory influences of adenosine on the heart have repeatedly been described by many investigators. These studies have shown that adenosine and adenine nucleotides have overall depressant effects, similar to those of acetylcholine. Heart beats become slow and weak. It is also well known that adenosine is a potent endogenous coronary vasodilator. Many investigations on the working mechanisms of adenosine have been focused mainly on the effects of the coronary blood flow. However, the cellular mechanisms underlying the inhibitory action of adenosine on sinus node are not well understood yet. Thus, this study was undertaken to examine the behavior of rabbit SA node under influence of adenosine. In these series of experiments three kinds of preparations were used: whole atrial pair, left atrial strip, and isolated SA node preparations. The electrical activity of SA node was recorded with conventional glass microelectrodes 30 to 50 $M{\Omega}$. The preparations were superfused with bicarbonate-buffered Tyrode solution of pH 7.35 and aerated with a gas mixture of $3%\;CO_2-97%\;O_2$ at $35^{\circ}C$. In whole atrial pair, adenosine suppressed sinoatrial rhythm in a dose-dependent manner. Effect of adenosine on atrial rate appeared at the concentration of $10^{-5}M$ and was enhanced in parallel with the increase in adenosine concentration. Inhibitory action of adenosine on pacemaker activity was more prominent in the preparation pretreated with norepinephrine, which can steepen the slope of pacemaker potential by increasing permeability of $Ca^{+2}$. Calcium ions in perfusate slowly produced a marked change in sinoatrial rhythm. Elevation of the calcium concentration from 0.3 to 8 mM increased the atrial rate from 132 to 174 beats/min, but over 10 mM $Ca^{+2}$ decreased. The inhibitory effect of adenosine on sinoatrial rhythm developed very rapidly. Atrial rate was recovered promptly from the adenosine-induced suppression by the addition of norepinephrine, but extra $Ca^{+2}$ was less suitable to restore the suppression of atrial rate. Adenosine suppressed also atrial contractility in the same dosage range that restricted pacemaker activity, even in the reserpinized preparation. In isolated SA node preparation, spontaneous firing rate of SA node at $35^{\circ}C$(mean{\pm}SEM, n=16) was $154{\pm}3.3\;beats/min. The parameters of action potentials were: maximum diastolic potential(MDP), $-73{\pm}1.7\;mV: overshoot(OS), $9{\pm}1.4\;mV: slope of pacemaker potential(SPP), $94{\pm}3.0\;mV/sec. Adenosine suppressed the firing rate of SA node in a dose-dependent manner. This inhibitory effect appeared at the concentration of $10^{-6}M$ and was in parallel with the increase in adenosine concentration. Changes in action potential by adenosine were dose-dependent increase of MDP and decrease of SPP until $10^{-4}M$. Above this concentration, however, the amplitude of action potential decreased markedly due to the simultaneous decrease of both MDP and OS. All these effects of adenosine were not affected by pretreatment of atropine and propranolol. Lowering extra $Ca^{2+}$ irom 2 mM to 0.3 mM resulted in a marked decrease of OS and SPP, but almost no change of MDP. However, increase of perfusate $Ca^{2+}$ from 2 mM to 6 or 8 mM produced a prominent decrease of MDP and a slight increase of OS and SPP. Dipyridamole(DPM), which is known to block the adenosine transport across the cell membrane, definately potentiated the action of adenosine. The results of this experiment suggest that adenosine suppressed pacemaker activity and atrial contractility simultaneously and directly, by decreasing $Ca^{2+}-permeability$ of nodal and atrial cell membranes.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.4
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• pp.519-528
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• 2003

A survey was conducted in certain parts of Haryana to record the prevalence of micro mineral deficiency in buffaloes. The prevalence of soil Cu, Co, Zn and Fe deficiency was 55.26%, 6.9%, 59.12% and 7.89% respectively. While that of fodder Cu, Co, Zn and Fe was 60.64%, 6.7%, 61.22% and 11.37% respectively. The overall prevalence of serum Cu, Co, Zn and Fe deficiency in Haryana was 59.2%, 19.1%, 59.2% and 19.9% respectively. The correlation co-efficient of Cu, Co, Zn and Fe in soil, fodder and serum was significant in most of the cases the values were above 0.8. Blood examination revealed significant decrease in haemoglobin and TEC level. However, no variation in level of TLC were observed in mineral deficient buffaloes. In micro mineral deficiency, thyroid hormone (T3 and T4) levels were decreased in buffaloes. Marginally lower concentration of vitamin A and E were observed in mineral deficient buffaloes in Haryana. The highest deficiency of micro minerals was 61.76% in copper at Ambala followed by 65.86% in zinc at Rhotak. For therapeutic studies a mineral mixture was prepared according to defiency obtained and fed to three groups of animals. Observation was recorded on 0, 15, 30, 45 and 60 days. Group A consist of normal healthy animals and group B mineral deficient animal untreated and group C mineral deficient animal, treated with prepared mineral mixture. 25 gram of mineral mixture was fed daily along with normal ration. There was increase in body weight, milk yield, haemoglobin concentration and total erythrocyte level in group C animals when compared to group B animals. The milk yield in group C animals increased to 6.970${\pm}$0.41 after 60th day of supplement in comparison to 0 day where it was 5.910${\pm}$0.37, similarly the body wt. of group C animals increased from 129.42${\pm}$01.13 (at 0 day) to 159.31${\pm}$03.61 at 60th day of treatment.