• 한국동물위생학회지
• /
• 제14권2호
• /
• pp.87-103
• /
• 1991

The somatic cell counts SCC and bacteria counts were done by D milk plant, P milk plant, S milk plant and Inch'${\v{\times}}n$ Vet. Serv. Lab from 1987 to 1990 with Coulter counter, Fossomatic 90, Bactoscan, Rolling ball viscometer and Resazurin reduction test. The results were summarized as follows 1. In the distribution of SCC of the bulk herd milk, D milk plant from Nov. 1989 to Oct. 1990 remarks 80.2% on the range below 500, 000, 14.5% ranging from 1, 000, 000 to 1, 500, 000, 1.2% ranging from 1, 500, 000 to 2, 000, 000, 0.69% ranging from 2, 000, 000 to 3, 000, 000, 0.71% on the range over 3, 000, 000. P milk plant remarks 237, 000 in the first half year and 251, 000 in the second half year in 1990 year. S milk plant remarks annual average of 335, 000 in 1987, 273, 000 in 1988 and 262, 000 in 1989. The individual record of Inch'${\v{\times}}n$ Vet. Serv Lab. remarks 79.35% and 80.2% below 500, 000 8.30% and 7.40% from 500, 000 to 1, 000, 000, 2.37% and 3.2% from 1, 000, 000 to 1, 500, 000, 2.77% and 2.30% from 1, 500, 000 to 2, 000, 000, 1.67% and 2.00% from 2, 000, 000 to 3, 000, 000, 5.53% and 4.40% over 3, 000, 000 in 1989 and 1990, respectively. The grade distirbution of SCC is as follows: D milk plant shows 1st grade-80.20%, 2nd grade-l6.5% and 3rd grade-3.30%. And P milk plant shows all 1st grade. S milk plant shows 87.30%, 8.6% and 4.1% in 1987 and 91.90%, 6.1% and 2.0% in 1988, and 92.40%, 6.1% and l.5% in 1989 on the 1st, 2nd and 3rd grade respectively. 2. The distribution of bacteria P milk plant reached 15.123 in 1st half year and 21.515 in 2nd half year. Also, S milk plant reached 81.5%, 12.5%, 6.0% in 1987, and 86.20%, 9.70%, 4.1% in 1988, and 86.2%, 10.8%, 3.0% in 1989 respectively for 1st, 2nd and 3rd grade. 3. The regional SCC distribution in D milk plant shows 1, 540, 000 in three regions and 714, 000 in one region. And monthly SCC distribution shows 671, 000 in December and 1, 165, 000 in June. 4. As a result of the individual SCC test, 9 times for 16 cows in “I”farm(1986-1988), and 6 times for 13 cows in“D”farm(1987-1988) No.3, 5, 9, 14 cows in“I”farm showed the high SCC beyond 1, 000, 000 over 4-5times. 5. If the SCC over 300, 000 reach 40%, the national producing quality of milk can be reduced by 87, 600M /I annually and in the sum of money, it should be about 35.5 billion Won. 6. The difference between high group and low group for SCC in D milk plant reached over 1, 000, 000. In case that the difference reaches 1, 000, 000 in the farm bulk milk at a farm breeding 20 cows which produce 20kg milk per day, it was estimate that the annual difference of producing quantity and sum of money respectively should be reached 26, 280kg in milk and 10, 643, 400 Won in income.

• Corrosion Science and Technology
• /
• 제15권1호
• /
• pp.18-27
• /
• 2016

In this study, the accelerated corrosion test by combined deteriorating action of salt damage and freeze-thaw was investigated. freeze-thaw cycle is one method for corrosion testing; corrosion initiation time was measured in four types of concrete samples, i.e., two samples mixed with fly ash (FA) and blast furnace slag (BS), and the other two samples having two water/cement ratio (W/C = 0.6, 0.35) without admixture (OPC60 and OPC35). The corrosion of rebar embedded in concrete occurred most quickly at the $30^{th}$ freeze-thaw cycle. Moreover, a corrosion monitoring method with a half-cell potential measurement and relative dynamic elastic modulus derived from resonant frequency measures was conducted simultaneously. The results indicated that the corrosion of rebar occurred when the relative dynamic elastic modulus was less than 60%. Therefore, dynamic elastic modulus can be used to detect corrosion of steel bar. The results of the accelerated corrosion test exhibited significant difference according to corrosion periods combined with each test condition. Consequently, the OPC60 showed the lowest corrosion resistance among the samples.

• Parasites, Hosts and Diseases
• /
• 제51권5호
• /
• pp.503-510
• /
• 2013

Toxoplasma gondii is an apicomplexan parasite with a broad host range of most warm-blooded mammals including humans, of which one-thirds of the human population has been infected worldwide which can cause congenital defects, abortion, and neonatal complications. Here, we developed a rapid diagnostic test (RDT) for T. gondii infection. Antigenic N-terminal half of the major surface antigen (SAG1) was linked with intrinsically unstructured domain (IUD) of dense granule protein 2 (GRA2). The recombinant GST-GRA2-SAG1A protein was successfully expressed and purified as 51 kDa of molecular weight. Furthermore, antigenicity and solubility of the rGST-GRA2-SAG1A protein were significantly increased. The overall specificity and sensitivity of GST-GRA2-SAG1A loaded RDT (TgRDT) were estimated as 100% and 97.1% by comparing with ELISA result which uses T. gondii whole cell lysates as the antigen. The TgRDT tested with Uganda people sera for field trial and showed 31.9% of seroprevalence against T. gondii antibody. The TgRDT is proved to be a kit for rapid and easy to use with high accuracy, which would be a suitable serodiagnostic tool for toxoplasmosis.

• 한국수소및신에너지학회논문집
• /
• 제32권5호
• /
• pp.401-409
• /
• 2021

The combination of different concentrations of ZnSO₄ in acidic solution as electrolyte in Zn-air batteries was investigated by Zn symmetrical cell test, half-cell and full cell tests. Using 1 M ZnSO₄ + 0.05 M H₂SO₄ as electrolyte and MnO₂ as air cathode catalyst with Zn foil anode, this combination had a satisfactory performance with balance of electrochemical activity and stability. Its electrochemical activity was matched to or even better than the PtRu catalyst in different current density. And its cycle life was improved (more than 100 cycles stable) by suppressing the growth of zinc dendrites on anode obviously. This electrolyte overcame the shortcomings of alkaline electrolyte that are easy to react with CO₂ in the air, severely growth of Zn dendrites caused by uneven plating/stripping of Zn.

• Journal of Periodontal and Implant Science
• /
• 제29권4호
• /
• pp.821-838
• /
• 1999

On the basis of the evidences that electrical stimulation could enhance proliferation and differentiation of bone cells and promote healing and regeneration of bone, this study was performed to investigate the effects of electrical stimulation on human periodontal ligament cells and gingival fibroblasts in vitro, which also have important roles in regeneration of periodontium, and to evaluate the potential of clinical application of electrical stimulation. Human periodontal ligament cells and gingival fibroblasts were primarily cultured from the root surface of extracted premolar and the adjacent gingiva without periodontal diseases. In control group, the cells ($5{\times}10^4$ cells/ml)were incubated only in Dulbecco's Modified Eagle's Medium contained with 10% fetal bovine serum. In test groups, electrical stimulation was given at the current intensity of $0.25{\mu]A$(test group 1), $1.0{\mu}A$(test group 2), and $2.5{\mu}A$(test group 3) for 12 hours to the same culture media with the control group. After 12 hour exposure of electrical stimulation, the cells were incubated for 2 and a half days(60 hours), and then each group of cells was analyzed for cell proliferation, protein level, and activity of alkaline phosphatase. The results were as follows ; 1. The Rate of cell proliferation of every test group increased significantly in both periodontal ligament cells and gingival fibroblasts, and in periodontal ligament cells, test group 3 showed significantly increased proliferation compared to the other test groups(p<0.05). 2. In the protein levels, neither periodontal ligament cell nor gingival fibroblast showed statistically significant differences between control and test groups. 3. The activity of alkaline phosphatase in periodontal ligament cells increased significantly in all test groups(p<0.05), but there were no significant differences between 3 test groups. In gingival fibroblasts, the activity of alkaline phosphatase increased significantly only in test group 3(p<0.05). From the above results, it is concluded that electrical stimulation may have beneficial effects on the regeneration of destructed periodontal tissue in regard of the stimulation of periodontal ligament cells and gingival fibroblasts as well as electrically stimulated bone formation that has been known, and that electrical stimulation may have the potential of clinical application.

• 한국동물위생학회지
• /
• 제36권4호
• /
• pp.255-261
• /
• 2013

The objective of the present study was to determine the minimum alcohol (ethanol) concentration that gives rise to the coagulation of goat milk for the alcohol precipitation test, and to evaluate the physical parameters of goat milk which include alcohol and heat stability. A total of 1,295 udder-half milk samples from 648 lactating dairy goats were collected from seven farms in Jeonnam province, Republic of Korea, to determine the alcohol and heat stability. The majority (99.6%) of the samples were coagulated when 70% ethanol was added to the milk, while only 11.0% of the samples were precipitated by the addition of an equal volume of 45% ethanol. With the concentration of 65%, 60%, 55% and 50% aqueous ethanol, 99.2%, 96.8%, 81.0% and 52.8% of the milk samples were coagulated, respectively. Of 1,295 dairy goat milk samples tested for heat stability, 127 (9.8%) were coagulated by boiling. Among the 143 alcohol test-positive udder-half milk samples, 52 (4.0%) were unstable by heat test, while 1,032 (79.7%) of the 1,152 alcohol test-negative milk samples were stable by heat test. According to the results of boiling test, sensitivity and specificity of 45% alcohol precipitation test were 0.3023 (95% CI: 0.2346~0.3772) and 0.9190 (95% CI: 0.9017~0.9344), respectively. The contents of protein and the specific gravity were higher in the milk samples of 45% alcohol test-positive than in those of 45% alcohol test-negative. However, lower levels of lactose and milk urea nitrogen were observed in the milk samples of 45% alcohol test-positive compared to the alcohol test-negative milk samples. The lowest pH values ($6.73{\pm}0.20$) were shown in the 45% alcohol test-negative and heat-unstable milk samples, while the lowest values of somatic cell counts and bacterial counts were shown in the 45% alcohol test-negative and heat-stable milk samples. Results of this study suggest that the alcohol precipitation for dairy goat milk may have to be tested with ethanol concentration less than 45% for the determination of freshness and heat-stability.

• 정보보호학회논문지
• /
• 제12권2호
• /
• pp.53-64
• /
• 2002

This paper describes a design of cryptographic processor that implements the AES (Advanced Encryption Standard) block cipher algorithm, "Rijndael". An iterative looping architecture using a single round block is adopted to minimize the hardware required. To achieve high throughput rate, a sub-pipeline stage is added by dividing the round function into two blocks, resulting that the second half of current round function and the first half of next round function are being simultaneously operated. The round block is implemented using 32-bit data path, so each sub-pipeline stage is executed for four clock cycles. The S-box, which is the dominant element of the round block in terms of required hardware resources, is designed using arithmetic circuit computing multiplicative inverse in GF($2^8$) rather than look-up table method, so that encryption and decryption can share the S-boxes. The round keys are generated by on-the-fly key scheduler. The crypto-processor designed in Verilog-HDL and synthesized using 0.25-$\mu\textrm{m}$ CMOS cell library consists of about 23,000 gates. Simulation results show that the critical path delay is about 8-ns and it can operate up to 120-MHz clock Sequency at 2.5-V supply. The designed core was verified using Xilinx FPGA board and test system.

• 전기화학회지
• /
• 제3권1호
• /
• pp.44-48
• /
• 2000

상온에서 DC-magnetron sputtering으로 증착한 비정질의 $V_2O_5$ 박막을 양극물질로 하여 $V_2O_5/LIPON/Li$으로 구성된 박막형 리튬이차전지를 제작하였다. $V_2O_5$의 양극특성은 액체전해질을 이용한 half cell 구조에서 평가하였으며, $Ar/O_2$ 분압비의 변화에 따라 제작된 $V_2O_5$ 양극은 분압비 80/20에서 가장 좋은 특성을 보였다. 자체 제작한 $Li_3PO_4$ 타겟을 사용하여 RF-sputtering으로 순수한 질소 분위기 하에서 양극 위에 고체전해질 LIPON 박막을 형성하였으며, 1.2-4.0V vs. Li 구간에서 리튬에 대해 반응성이 없는 안정한 화합물임을 확인하였다. 음극으로 쓰인 약 $2{\mu}m$두께의 금속리튬박막은 진공 열 증착법으로 제조하였으며, $V_2O_5/LIPON/Li$의 박막형 리튬이차전지는 $1.2\~3.5V$ 구간에서 초기에 약 $150{\mu}A/cm^2{\mu}m$의 높은 방전용량을 나타내었다.

• 전자공학회논문지SC
• /
• 제46권2호
• /
• pp.72-77
• /
• 2009

본 논문은 별도 기준 클록 없이 고속 시리얼 데이터 통신을 위한 3.2Gb/s 클록 데이터 복원(CDR) 회로를 설명한다. CDR회로는 전체적으로 5부분으로 구성되며, 위상검출기(PD)와 주파수 검출기(FD), 다중 위상 전압 제어 발진기(VCO), 전하펌프(CP), 외부 루프필터(LF)로 구성되어 있다. CDR회로는 half-rate bang-bang 타입의 위상 검출기와 입력 pull-in 범위를 늘릴 수 있도록 half-rate 주파수 검출기를 적용하였다. VCO는 4단의 차동 지연단(delay cell)으로 구성되어 있으며 튜닝 범위와 선형성 향상을 위해 rail-to-rail 전류 바이어스단을 적용하였다 각 지연단은 풀 스윙과 듀티의 부정합을 보상할 수 있는 출력 버퍼를 갖고 있다. 구현한 CDR회로는 별도의 기준 클록 없이 넓은 pull-in 범위를 확보할 수 있으며 기준 클록 생성을 위한 부가적인 Phase-Locked Loop를 필요치 않기 때문에 칩의 면적과 전력소비를 효과적으로 줄일 수 있다. 본 CDR 회로는 0.18um 1P6M CMOS 공정을 이용하여 제작하였고 루프 필터를 제외한 전체 칩 면적은 $1{\times}1mm^2$이다. 3.2Gb/s 입력 데이터 율에서 모의실험을 통한 복원된 클록의 pk-pk 지터는 26ps이며 1.8V 전원전압에서 전체 전력소모는 63mW로 나타났다. 동일한 입력 데이터 율에서 테스트를 통한 pk-pk 지터 결과는 55ps였으며 신뢰할 수 있는 입력 데이터율 범위는 약 2.4Gb/s에서 3.4Gb/s로 나타났다.

• 보존과학회지
• /
• 제34권6호
• /
• pp.503-515
• /
• 2018

원주 법천사지 지광국사탑의 1957년 수리 복원에 사용된 모르타르의 손상정도를 평가하고 제거 필요성에 대한 객관적인 데이터를 제공하기 위해 콘크리트 분야에서 사용되는 반전위측정방법을 적용하였다. 철근이 사용된 옥개석 모르타르와 실내 실험체의 촉진부식시험 후 반전위 측정값에 대한 다중회귀분석 결과, 부식량과 피복두께에 따른 HCP 값의 결정계수는 0.86이상의 높은 상관식이 도출되었다. ASTM C876기준에 따르면 옥개석의 습윤상태 측정값 - 431~-663 mV는 철근의 부식손상 확률이 90%이상이기 때문에 손상된 모르타르를 제거한 후 신석재를 사용한 복원이 필요한 것으로 판단된다.