• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.22 no.3
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• pp.399-405
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• 2011

In this paper, we present the design of Q-band LC VCO and injection locking buffer for 77 GHz automotive radar sensor using 130 nm RF CMOS process. To improve the phase noise characteristic of LC tank, the transmission line is used. The negative resistance by the active device cross-coupled pair of buffer is used for high output power, with or without oscillation of buffer. The measured phase noise is -102 dBc/Hz at 1 MHz offset frequency and tuning range is 34.53~35.07 GHz. The output power is higher than 4.1 dBm over entire tuning range. The fabricated chip size is $510{\times}130\;um^2$. The power consumption of LC VCO is 10.8 mW and injection locking buffer is 50.4 mW from 1.2 V supply.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.40 no.8
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• pp.598-609
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• 2003

This paper describes a CMOS IF PLL frequency synthesizer. The designed frequency synthesizer can be programmed to operate at various intermediate frequencies using different external LC-tanks. The VCO with automatic amplitude control provides constant output power independent of the Q-factor of the external LC-tank. The designed frequency divider includes an 8/9 or 16/17 dual-modulus prescaler and can be programmed to operate at different frequencies by external serial data for various applications. The designed circuit is fabricated using a 0.35${\mu}{\textrm}{m}$ n-well CMOS process. Measurement results show that the phase noise is 114dBc/Hz@100kHz and the lock time is less than 300$mutextrm{s}$. It consumes 16mW from 3V supply. The die area is 730${\mu}{\textrm}{m}$$\times$950${\mu}{\textrm}{m}$.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.52 no.3
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• pp.268-273
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• 2019

This study evaluated acute nitrate nitrogen ($NO_3-N$) toxicity in juvenile blackhead seabream Acanthopagrus schlegelii. Seventy juveniles (Trial A, $7.1{\pm}0.6g$) and nine juveniles (Trial B, $71.3{\pm}3.5g$) per 70 L tank were exposed to $NO_3-N$ concentrations of 0, 500, 1500, 2500, 3500, and 4500 mg/L and 0, 600, 1200, 1800, 2400, and 3000 mg/L, respectively, in triplicate for 7 days. In Trial A, all fish exposed to 3500 and $4500mg\;NO_3-N/L$ died within 48 h; in Trial B, all fish exposed to $3000\;NO_3-N/L$ died after 120 h. The $96\;LC_{50}$ and $168\;LC_{50}$ were 2505 and $1806mg\;NO_3-N/L$, respectively, in Trial A, and 2663 and $2377mg\;NO_3-N/L$ in Trial B. Large juveniles were more resistant to $NO_3-N$ than small juveniles. The results of acute $NO_3-N$ toxicity studies provide important data for subsequent chronic toxicity studies.

• Journal of Animal Science and Technology
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• v.58 no.7
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• pp.24.1-24.7
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• 2016

Background: Clinoptilolite is a natural zeolite with high adsorption capacity for polar mycotoxins such as aflatoxins. The efficacy of clinoptilolite in ameliorating the toxic effects of aflatoxicosis has been proven in monogastric animals, but there is no such evidence for ruminants. The aim of this study was to evaluate, under field conditions, whether the dietary administration of clinoptilolite in dairy cows could reduce the concentration of aflatoxin M1 ($AFM_1$) in bulk-tank milk, in farms with higher than or close to $0.05{\mu}g/kg$ of milk (European maximum allowed residual level). An objective of the present study was also to investigate the effect of particle size of clinoptilolite on aflatoxin binding. Methods: Fifteen commercial Greek dairy herds with AFM1 concentrations in bulk tank milk ${\geq}0.05{\mu}g/kg$ were selected. Bulk tank milk AFM1 was determined prior to the onset and on day 7 of the experiment. Clinoptilolite was added in the total mixed rations of all farms at the rate of 200 g per animal per day, throughout this period. Two different particle sizes of clinoptilolite were used; less than 0.15 mm in 9 farms (LC group) and less than 0.8 mm in 6 farms (HC group). Results: Clinoptilolite administration significantly reduced $AFM_1$ concentrations in milk in all farms tested at an average rate of 56.2 % (SD: 15.11). The mean milk $AFM_1$ concentration recorded on Day 7 was significantly (P < 0.001) lower compared to that of Day 0 ($0.036{\pm}0.0061$ vs. $0.078{\pm}0.0074{\mu}g/kg$). In LC group farms the reduction of milk $AFM_1$ concentration was significantly higher than HC group farms ($0.046{\pm}0.0074$ vs. $0.036{\pm}0.0061{\mu}g/kg$, P = 0.002). As indicated by the Pearson correlation, there was a significant and strong linear correlation among the milk $AFM_1$ concentrations on Days 0 and 7 (R = 0.95, P < 0.001). Conclusions: Dietary administration of clinoptilolite, especially of smallest particle size, at the rate of 200 g per cow per day can effectively reduce milk $AFM_1$ concentration in dairy cattle and can be used as a preventive measure for the amelioration of the risks associated with the presence of aflatoxins in the milk of dairy cows.

• Journal of Life Science
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• v.30 no.4
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• pp.321-330
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• 2020

The aim of this study was to investigate the effect of copper (II) chloride (CuCl₂) on zebrafish. Zebrafish were exposed to various CuCl₂ concentrations and subjected to different exposure times to determine the median lethal concentration (LC₅₀) values. To evaluate stress responses, we measured whole-body cortisol levels and behavioral parameters using the open field test (OFT) or the novel tank test (NTT). The zebrafish were exposed to CuCl₂ solution at concentrations of 1.5-150 ㎍/l or a vehicle for 1 hr before behavioral tests or sample collection for whole-body cortisol. The LC₅₀ values were 30.3, 25.3, and 14.8 ㎍/l at 24, 48, and 96 hr, respectively. The NTT showed that mobility, velocity, and distance covered were significantly lower in zebrafish exposed to CuCl₂ than in the control group (p<0.05), while the turn angle was significantly higher in zebrafish exposed to a CuCl₂ concentration of 150 ㎍/l than in the control group (p<0.05). The OFT also showed that mobility, velocity, and distance covered were significantly lower and the turn angle and meandering were significantly higher in zebrafish exposed to all concentrations of CuCl₂ than in the control group (p<0.05). The whole-body cortisol levels were significantly higher in zebrafish exposed to CuCl₂ than in the control group (p<0.05). These results suggest that exposure to lethal CuCl₂ concentrations induces an intense toxic and stress response in zebrafish, causing behavioral changes and increasing whole-body cortisol levels.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.45 no.4
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• pp.36-42
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• 2008

40Gb/s CMOS Clock and Data Recovery circuit design for optical serial link is proposed. The circuit generates 8 multiphase clock using LC tank PLL and controls the phase between the clock and the data using the $2{\times}$ oversampling Bang-Bang PD. 40Gb/s input data is 1:4 demultiplexed and recovered to 4 channel 10Gb/s outputs. The design was progressed to separate the analog power and the digital power. The area of the chip is $2.8{\times}2.4mm^2$ for the inductors and the power dissipation is about 200mW. The chip has been fabricated using 0.18um CMOS process. The measured results show that the chip recovers the data up to 9.5Gb/s per channel(Equivalent to serial input rate of up to 38Gb/s).

• Journal of the Society of Disaster Information
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• v.9 no.4
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• pp.449-461
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• 2013

As the hydrofluoric acid leak in Gumi-si, Gyeongsangbuk-do or hydrochloric acid leak in Ulsan, Gyeongsangnam-do demonstrated, chemical related accidents are mostly caused by large amounts of volatile toxic substances leaking due to the damages of storage tank or pipe lines of transporter. Safety assessment is the most important concern because such toxic material accidents cause human and material damages to the environment and atmosphere of the surrounding area. Therefore, in this study, a hydrofluoric acid leaked from a storage tank was selected as the study example to simulate the leaked substance diffusing into the atmosphere and result analysis was performed through the numerical Analysis and diffusion simulation of ALOHA(Areal Location of Hazardous Atmospheres). the results of a qualitative evaluation of HAZOP (Hazard Operability)was looked at to find that the flange leak, operation delay due to leakage of the valve and the hose, and toxic gas leak were danger factors. Possibility of fire from temperature, pressure and corrosion, nitrogen supply overpressure and toxic leak from internal corrosion of tank or pipe joints were also found to be high. ALOHA resulting effects were a little different depending on the input data of Dense Gas Model, however, the wind direction and speed, rather than atmospheric stability, played bigger role. Higher wind speed affected the diffusion of contaminant. In term of the diffusion concentration, both liquid and gas leaks resulted in almost the same $LC_{50}$ and ALOHA AEGL-3(Acute Exposure Guidline Level) values. Each scenarios showed almost identical results in ALOHA model. Therefore, a buffer distance of toxic gas can be determined by comparing the numerical analysis and the diffusion concentration to the IDLH(Immediately Dangerous to Life and Health). Such study will help perform the risk assessment of toxic leak more efficiently and be utilized in establishing community emergency response system properly.

• Proceedings of the KIEE Conference
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• 2003.10b
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• pp.209-212
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• 2003

This paper proposes a soft-transition control strategy for a three phase ZCS(Zero Current Switching) inverter circuit. Each phase leg of inverter circuit consists of an LC resonant tank, two main switches, and one auxiliary switches. This paper presents design consideration via a study example of a three phase prototype inverter for motor drives. A simple device tester with zero current switching capability is proposed to select eligible auxiliary switches. The principle of operation, feature and design considerations are illustrated and verified through the experiment with a 2.2kW 5kHz IGBT based experimental circuit.

• Proceedings of the KIPE Conference
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• 2008.06a
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• pp.157-159
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• 2008

Generally, Capacitor charging power supply (CCPS) consist of the full-bridge inverter, LC resonant tank and capacitance load. The multi-connection systems are normally used for high voltage or high power application. In this paper, conventional parallel operation resonant type and proposed series operation PWM type CCPS for pulse corona occurrence of DeSOx, DeNOx system using magnetic pulse compressor make a comparison. The effect of proposed CCPS is verified by circuit characteristics analysis of parallel operation resonant type and series operation PWM type, and it is confirmed by simulation result.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 2006.07a
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• pp.716-716
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• 2006