• Journal of Electrochemical Science and Technology
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• 제15권1호
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• pp.178-189
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• 2024

This work aims to investigate the efficiency of electrocoagulation (EC) of pistachio processing industrial wastewater (PPIW) using the continuous EC process. The tubular reactor made of stainless steel with an internal diameter of 60 mm was used as a cathode electrode. The effect of some parameters was examined on the removal of chemical oxygen demand (COD) and total phenols (TP) removal efficiency. The influences of the initial pH of wastewater (from 4 to 8), flow rate (from 25 to 125 mL/min), current density (from 7 to 21 mA/cm²), and supporting electrolyte type (NaCl, NaNO₃, and Na₂SO₄), supporting electrolyte concentration (from 10 to 100 mg/L NaCl) on removal efficiency were investigated to determine the best experimental conditions. The examination of the physico-chemical parameters during the EC treatment showed that the best removal efficiency was obtained under conditions where the flow rate was 25 mL/min (20 min reaction time), the pH value was 5.2, and the current density was 21 mA/cm² has set. Under these experimental conditions, COD and TP removal efficiency were found to be 75% and 97%, respectively, while energy consumption was 18.5 kW h/m³. The study results show that the EC can be applied to PPIW pre-treatment.

• 소성∙가공
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• 제21권3호
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• pp.179-185
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• 2012

In this paper, it is proposed to produce high precision screws with a diameter of $800{\mu}m$ and a thread pitch of $200{\mu}m$ ($M0.8{\times}P0.2$) by means of a cold thread rolling process. In this part II of the study, the focus is on the production and reliability testing of the prototype $M0.8{\times}P0.2$ micro-screw. Designs for two flat dies were developed with the aid of the literature and previous studies. Process parameters during the cold thread rolling process were established through FE simulations. The simulation results showed that the threads of the micro-screw are completely formed through the rolling process. Prototype $M0.8{\times}P0.2$ micro-screw were fabricated with a high precision thread rolling machine. In order to verify the simulation results, the deformed shape and dimensions obtained from the experiment were compared with those from the simulations. Hardness and failure torque of the fabricated micro-screw were also measured. The values obtained indicate that the CAE based process design used in this paper is very appropriate for the thread rolling of micro-sized screws.

• Journal of Animal Science and Technology
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• 제57권12호
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• pp.45.1-45.5
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• 2015

Background: Physical and chemical properties of feedstuffs can be changed by feed processing. Moreover, through various mechanisms, feed processing can affect growth performance and feed efficiency of swine, nutrition value of the feed. Weaning-to service-intervals (WSI), subsequent farrowing rates, and total-born litter sizes were determined by feed intake and metabolic state during lactation. Methods: A total of 20 sows (Landrace ${\times}$ Yorkshire) with an average body weight (BW) of 266.1 kg 4 d before farrowing were used to determine the effect of feed processing on the performance of lactating sows and their offspring. The following two dietary treatments were used: 1) Crumble diet (C); and 2) Mash diet (M). Ten replications were used for each treatment. Back fat thickness of sows was measured 6 cm off the midline at the 10th rib using a real-time ultrasound instrument at 4 d before farrowing, 1 d after farrowing, and during weaning. Sow BW were also checked at 4 d before farrowing, 1 d after farrowing, and during weaning. Fecal score of sows were assessed on d 14. Fecal score of piglets were observed on d 7, 15, and 24. Data were analyzed using t-test procedure of SAS (2014) with sow as experimental unit. Results: No significant (p > 0.05) difference was observed in the reproduction performance of sows between the two treatments. In addition, there was no significant (p > 0.05) difference in the growth performance of piglets between the two treatments. Fecal score of sows or piglets showed no significant (p > 0.05) difference either. Conclusions: In conclusion, different feed processing (mash or crumble) did not make any significant difference on the performance of lactation sow or their piglets.

• 기술사
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• 제15권4호
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• pp.37-40
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• 1982

I investigated the processing-treatment of livestocks feces and body wastes in Tok- ushima prefecture, and made clear the problems relative to its influence to environments. Nowadays the load of pollution of the m is as following. COD P livestock 8.8% 38.5% body wastes 1,2 4.5 As for the livestock feces, the method of evaporation-permeation is more general than that of oxidation process because of costs. Another way is that the dung will be changed into the compost. However as these methods pollute environments remarkably, a large-scale digesting process is being planned. In case of the processing of body wastes, costs for the processing plant tend to increase to the highest level in accordance with the strong power inhabitants. In all processing, we suffer from a large amount of economical loads.

• 한국세라믹학회지
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• 제48권5호
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• pp.463-466
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• 2011

Wet foams formed through direct foaming were stabilized using various concentrations of amiphiphilic particles that could control pore size and porosity. These porous materials showed moderate strength upon compression with high porosity. Bubble size and wet foam stability were tailored by amphiphile concentration, particle concentration, contact angle, and pH of the suspension to obtain crack-free porous solid after sintering. Closed and open pores were obtained with sizes of 30~300 ${\mu}m$ and porosities of over 80%.

• Journal of Ceramic Processing Research
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• 제19권5호
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• pp.394-400
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• 2018

The current work investigates the effects of nucleation heat treatments, on the microstructure and mechanical properties of a novel silicate glass in $Li_2O-BaO-SiO_2$ system with 1 mol% $P_2O_5$ as nucleating agent. As-cast glass was exposed to nucleation heat treatments at $490-550^{\circ}C$ for 1-3 h. The microstructural examination was performed by SEM/EDS. The highest Vickers microhardness was determined to be 650 Hv for the sample heat treated at $550^{\circ}C$ for 1 h. The increase in the nucleation time also affected Vickers microhardness and the highest one was determined to be 600 Hv after nucleation for 3 h. The fracture toughness, $K_{IC}$ reached $2.51MPa.m^{1/2}$ after nucleation at $550^{\circ}C$ for 1 h. The nucleation temperatures had a more pronounced effect on the fracture toughnesses in comparison to nucleation times. The indentation toughness data was used to determine Weibull parameters from Ln ln [1/(1-P)]-$lnK_{IC}$ plots. Weibull modulus, m of the samples nucleated at 500, 510, 530, $550^{\circ}C$ for 1h. and $540^{\circ}C$ for 2 h. were determined similarly to be 3.8, 3.5, 4.7 and 3.9, respectively. The rest of the samples indicated higher Weibull moduli, which may be attributed to the formations of microcracks due to the mismatch in between newly formed crystals and remaining glassy matrix.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2008년도 추계학술발표대회
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• pp.1332-1335
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• 2008

In order to various service types of real time and non-real time traffic with varying requirements are transmitted over the IEEE 802.16 standard is expected to provide quality of service(QoS) researchers have explored to provide a queue management scheme with differentiated loss guarantees for the future Internet. The sides of a packet drop rate, an each class to differential drop probability on achieving a low delay and high traffic intensity. Improved a queue management scheme to be enhanced to offer a drop probability is desired necessarily. This paper considers multiple random early detection with differential drop probability which is a slightly modified version of the Multiple-RED(Random Early Detection) model, to get the performance of the best suited, we analyzes its main control parameters (max_th, min_th, max_p) for achieving the proportional loss differentiation (PLD) model, and gives their setting guidance from the analytic approach. we propose Dynamic-multiple queue management scheme based on differential drop probability, called Dynamic-VQSDDP(Variable Queue State Differential Drop Probability)T, is proposed to overcome M-RED's shortcoming as well as supports static max_p parameter setting values for relative and each class proportional loss differentiation. M-RED is static according to the situation of the network traffic, Network environment is very dynamic situation. Therefore max_p parameter values needs to modify too to the constantly and dynamic. The verification of the guidance is shown with figuring out loss probability using a proposed algorithm under dynamic offered load and is also selection problem of optimal values of parameters for high traffic intensity and show that Dynamic-VQSDDP has the better performance in terms of packet drop rate. We also demonstrated using an ns-2 network simulation.

• 한국식품영양과학회지
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• 제36권4호
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• pp.395-399
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• 2007

각종 미네랄과 무기염류의 함량이 풍부한 것으로 알려진 함초를 이용하여 발효 후 그에 따른 기능성을 검토해 보고자 하였다. 유산균 접종 후 pH는 초기 4.50에서 발효 후 2.84로 변했으며, 산도는 초기 0.29에서 발효 후 0.55로 증가하였다. 한편 생균수를 측정한 결과 초기 $1.2{\times}10^{11}CFU/mL$이었던 생균수는 발효 72시간 후 $1.4{\times}10^{13}CFU/mL$를 보였다. 함초 추출물 발효액을 동결건조시킨 후 그에 따른 기능성을 검토하였으며 SOD-유사활성과 DPPH-라디칼 소거능 측정결과, 농도 의존적인 경향을 보였으며 혈전분해능 측정결과 발효 전의 함초 추출물에서는 나타나지 않았던 혈전분해능을 발효 후 동결건조분말 25%의 시료 농도에서 plasmin $3.84{\mu}g/mL$의 농도와 동일한 수준의 혈전용해능을 보였다.

• 한국레이저가공학회지
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• 제10권4호
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• pp.13-17
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• 2007

Electron beam weldability was investigated for 1mm thick cold rolled sheets of commercially pure grade titanium and Ti-6Al-4V alloy. Accelerating voltage of 40kV, beam current of 6mA, and weld speed of 0.8m/min was used and focal position of focused electron beam was just on the surface of workpiece. Microstructure of weld metal, the heat affected zone and base metal was observed using optical microscope. Vickers hardness was measured across the welds and the transverse tensile test was carried out. Hydroformability test was also carried out for the butt welded coupons of commercially pure grade titanium. For the electron beam welded C P Ti, the average grain size was equiaxed $\alpha(15{\sim}25{\mu}m)$ for base metal, coarse equiaxed $\alpha(80{\sim}200{\mu}m)$ for weld metal and annealed and enlarged grain($40{\sim}120{\mu}m$) for the HAZ. The vickers hardness of C P Ti was $180{\sim}200Hv$ for base metal, and $160{\sim}180Hv$ for the weld metal and the HAZ. For the electron beam welded Ti-6Al-4V alloy, the vickers hardness was 360Hv for the base metal, abd $400{\sim}425Hv$ for the weld metal and the HAZ. All the failure occurred at the base metal, when the transverse weld tensile test was carried out for both electron beam welded C P Ti and Ti-6Al-4V alloy. The formability of electron beam welded C P Ti was decreased compared with that of C P Ti base alloy.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2017년도 추계학술발표대회
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• pp.442-445
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• 2017

전자투표시스템이 도입되었지만, 투표 과정에서 안정성 및 신뢰성 문제는 매번 제시되고 있다. 본 논문에서는 최근 보안 분야에서 주목받고 있는 블록체인 기술을 도입하여 위 문제를 해결하고자 한다. 블록체임 기술이란 기존의 서버-클라이언트 형태의 중앙 집중형이 아닌 P2P로 구현된 분산형 플랫폼을 제공하는 기술이다. 이를 활용해 다양한 분야에서 기반기술로써 사용될 수 있다. 데이터가 한 곳에 집중되는 것이 아닌 시스템에 참여한 모든 사용자가 동인한 데이터를 공유하기에 투명성, 공정성을 보증할 수 있다. 본 논문에서는 이 특징을 활용한 블록체인 기반 전자투표시스템을 제안한다. 이 시스템은 사용자가 시행한 투표와 관련된 정보를 블록으로 생성하여 모든 유권자에게 배포하며, 블록의 정당성을 검사한다. 또한, 사용자가 가진 블록체인을 분석하여 결과를 실시간으로 시각화한다.