Mechanical properties of (W,Ti)C and (W,Ti)C-NiAl₃ cermet consolidated by the high-frequency induction-heating method

Kim, W.,Suh, C.Y.,Roh, K.M.,Cho, S.W.,Na, K.I.,Shon, I.J. Elsevier Sequoia 2013 Journal of alloys and compounds Vol.568 No.-

In the case of cemented (W,Ti)C, Co is added as a binder for the formation of composite structures. However, the high cost of Co and the low corrosion resistance of the (W,Ti)C-Co cermet have generated interest in recent years for alternative binder phases. In this study, NiAl<SUB>3</SUB> was used as a binder and consolidated by the high-frequency induction heated sintering (HFIHS) method. The densification of both monolithic (W,Ti)C and (W,Ti)C-NiAl<SUB>3</SUB> cermet was accomplished within 3min. Highly dense (W,Ti)C and (W,Ti)C-NiAl<SUB>3</SUB> with a relative density of upto 99% were obtained within 3min by HFIHS under a pressure of 80MPa. The method was found to enable not only the rapid densification but also the prohibition of grain growth preserving the nano-scale microstructure. The average grain sizes of the sintered (W,Ti)C and (W,Ti)C-NiAl<SUB>3</SUB> were lower than 100nm. The addition of NiAl<SUB>3</SUB> to (W,Ti)C enhanced the toughness at the expense of the slight decrease in hardness. The hardness of (W,Ti)C and (W,Ti)C-NiAl<SUB>3</SUB> was significantly higher than that of (W,Ti)C-Co or (W,Ti)C-Ni. The fracture toughness and hardness values of (W,Ti)C, (W,Ti)C-5vol.%NiAl<SUB>3</SUB>, and (W,Ti)C-10vol.%NiAl<SUB>3</SUB> consolidated by HFIHS with a pressure of 80MPa and a induced current were 7.6+/-0.4MPam<SUP>½</SUP> and 2850+/-35kg/mm<SUP>2</SUP>, 8.5+/-0.3MPam<SUP>½</SUP> and 2610+/-37kg/mm<SUP>2</SUP>, 9.7+/-0.5MPam<SUP>½</SUP> and 2520+/-26kg/mm<SUP>2</SUP>, respectively.

한우 비육에 관한 연구 1 . Methylthiouracil 첨가 및 Estradiol 17β - Cypionate 주사가 약령 모우 비육에 미치는 효과

김창기 ( C K Kim ),이택원 ( T W Lee ),김종욱 ( J W Kim ),배대식 ( D S Bae ),오선균 ( S K Oh ),조지훈 ( C H Cho ),김법회 ( B H Kim ),김상렬 ( S Y Kim ),배신석 ( S S Bae ) 한국축산학회 1971 한국축산학회지 Vol.13 No.1

This study was performed to affirm any effects of methylthiouracil and estradiol 17β-cypionate administered to young bulls for short term fattening. Eighteen bulls of Korean native breed, approximately 1.5 to 2 years of age and 260㎏ to 360㎏ in weight, were used in this study. All bulls had received a basal ration of soiling corn and concentrate made up of 55% grains, 40% brans and 5% others, in a period of 40 days. Bulls were divided into six groups as follows: group C was not treated, group M-2 received 2g of methylthiouracil per day, group M-3 received 3g of methylthiouracil per day, group EM-0 was injected intramusculary with 25㎎ of estradiol 17β-cypionate in the neck region 10 days after the beginning of the fattening period, group EM-2 was injected with estradiol 17β-cypionate as above mentioned and simultaneously received 2g of methylthiouracil per day, and group EM-3 was injected with estradiol 17β-cypionate as above mentioned and simultaneously received 3g of methylthiouracil per day. The results obtained were summarized as follows. 1. The average daily gain was for group C: 0.83㎏, group M-2: 1.07㎏, group M-3: 1.40㎏, group EM-0, 0.93㎏, group EM-2: 0.95㎏, and group EM-3: 1.18㎏. The M-3 group gained significantly(P$lt;0.05) more weight than C and EM-0 group. There were no significant differences in the average daily gain between the groups injected with estradiol 17β-eypionate and the control group. 2. The average daily concentrate intake was as follows: group C: 5.47㎏, group M-2: 5.00㎏, group M-3: 4.52㎏, group EM-0: 5.21㎏, group EM-2: 4.35㎏, and group EM-3: 4.61㎏. The consumption of concentrate was decreased by 17% in the M-3 group compared with the C group. There was no significant difference in the soiling corn intake among these groups. 3. Feed consumed for 1㎏ gain were decreased by the supplementation of methylthiouracil. The consumption of DCP for 1㎏ gain was in group C: 0.82㎏, group M-2: 0.59㎏, group M-3: 0.41㎏, group EM-0: 0.70㎏, group EM-2: 0.59㎏, and group EM-3: 0.50㎏. The amounts of TDN required were; group C: 6.57㎏, group M-2: 4.76㎏, group M-3: 3.39㎏, group EM-0: 5.67㎏, group EM-Z: 4.87㎏, and group EM-3: 4.08㎏. The consumption of DCP and TDN for 1㎏ gain in the M-3 group was about a half of that in the C group. 4. There was not any significant difference in the increase in body measurements among the various groups. 5. The average margins in the fattening period of 40 days were for group C: 2,950won, group M-2: 5,327won, group M-3: 9,158won, group EM-0: 3,310won, group EM-2: 3,623won, and group EM-3: 5,575won. The margin of group M-3 was about three times higher than that of group C. In short, this experiment demonstrated that methylthiouracil when fed to young native Korean bulls at the proper level 40 days before slaughter would bring a noticeable effect on weight gain, feed efficiency and economic advantage. There were no advantages from the simultaneous injecting estradiol 17β-cypionate with methylthiouracil. The proper supplementation level of methylthiouracil would appear to be 3g per head per day in this experiment.

Characterization of Phosphoinositide-3-kinase, Class 3 (PIK3C3) Gene and Association Tests with Quantitative Traits in Pigs

Kim, J.H.,Choi, B.H.,Lim, H.T.,Park, E.W.,Lee, S.H.,Seo, B.Y.,Cho, I.C.,Lee, J.G.,Oh, S.J.,Jeon, J.T. Asian Australasian Association of Animal Productio 2005 Animal Bioscience Vol.18 No.12

This study deals with the characterization of porcine PIK3C3 and association tests with quantitative traits. PIK3C3 belongs to the class 3 PI3Ks that participate in the regulation of hepatic glucose output, glycogen synthase, and antilipolysis in typical insulin target cells such as those in the such as liver, muscle system, and fat. On the analysis of full-length mRNA sequence, the length of the PIK3C3 CDS was recorded as 2,664 bps. As well, nucleotide and amino acid identities between human and pig subjects were 92% and 99%, respectively. Five SNPs were detected over 5 exons. We performed genotyping by using a SNP C2604T on exon24 for 145 F$_2$ animals (from a cross between Korean native boars and Landrace sows) by PCR-RFLP analysis with Hpy8I used to investigate the relationship between growth and fat depot traits. In the total association analysis, which doesn' consider transmission disequilibrium, the SNP showed a significant effect (p<0.05) on body weight and carcass fat at 30 weeks of age as well as a highly significant effect (p<0.01) on back fat. In an additional sib-pair analysis, C allele still showed positive and significant effects (p<0.05) on back fat thickness and carcass fat. Moreover, the effects of C allele on the means of within-family components for carcass fat and back fat were estimated as 2.76 kg and 5.07 mm, respectively. As a result, the SNP of porcine PIK3C3 discovered in this study could be utilized as a possible genetic marker for the selection of pigs that possess low levels of back fat and carcass fat at the slaughter weight.

Glass / p μc-Si:H 특성에 따른 i μc-Si:H 층 및 태양전지 특성변화 분석

장지훈(Jang, J.H.),이지은(Lee, J.E.),김영진(Kim, Y.J.),정진원(Jung, J.W.),박상현(Park, S.H,),조준식(Cho, J.S.),윤경훈(Yoon, K.H.),송진수(Song, J.),박해웅(Park, H.W.),이정철(Lee, J.C.) 한국신재생에너지학회 2009 한국신재생에너지학회 학술대회논문집 Vol.2009 No.06

PECVD를 이용하여 제조된 미세결정질 p-i-n 실리콘 박막 태양전지에서, p 층은 태양전지의 윈도우 역할 및 그 위에 증착될 i {mu}c-Si:H 층의 'seed'층 역할을 수행하기 때문에, p층의 구조적 및 전기적, 광학적 특성은 태양전지의 전체 성능에 큰 영향을 미칠 수 있다. 본 연구에서는 SiH₄ 농도를 변화시켜 각기 다른 결정 특성을 갖는 p {mu}c-Si:H층을 제조하고 그 위에 i {mu}c-Si:H 층을 증착하여 p층의 결정 특성변화와 그에 따른 i {mu}c-Si:H 층 및 'superstrate' p-i-n 미세결정질 실리콘 박막 태양전지의 특성 변화를 조사하였다. P층의 경우, SiH₄ 농도가 증가함에 따라 결정분율 (Xc)이 감소하여 비정질화되었으며 그에 따라 dark conductivity가 감소하는 경향을 나타내었다. 각기 다른 결정분율을 가지는 p 'seed' 층 위에 증착된 태양전지는, p 'seed' 층의 결정분율이 증가함에 따라 개방전압, 곡선인자, 변환효율이 경향적으로 감소하였다. 이는 p 층 결정분율 변화에 따른 p/i 계면특성 저하 및 그 위에 증착되는 i {mu}c-Si:H 층의 결함밀도 증가 등에 따른 태양전지 특성 감소 때문인 것으로 판단되며, 이를 분석하기 위하여 i {mu}c-Si:H 층의 전기적, 구조적 특성 분석 및 태양전지의 dark I-V 특성 등을 분석하고자 한다.

능동형 태그를 포함한 900MHz RFID 교육용 시스템의 설계

김휴찬 ( H. C. Kim ),올자스 ( A. Ohlzahas ),김종민 ( J. M. Kim ),진효석 ( H. S. Jin ),조동관 ( D. G. Cho ),정중수 ( J. S. Chung ),강오한 ( O. H. Kang ),정광욱 ( K. W. Jung ) 한국인터넷정보학회 2007 인터넷정보학회논문지 Vol.8 No.4

본 논문에서는 RFID 기술 중 리더와 태그간 900MHz 대역을 사용하여 교육용 시스템 설계를 제시하였다. 능동형 태그와 리더의 설계를 임베디드 환경에서 제시하였으며 리더와 접속 가능한 서버의 소프트웨어 개발은 PC 윈도우 운영체제 환경에서 실현하였다. 개발 환경으로는 AT89C51ED2가 리더와 태그의 프로세서로, 개발 언어는 C 언어로, 이를 제어하기 위하여 케일 C 컴파일러가 사용되었다. 서버인 PC에서는 비쥬얼 스튜디오상의 비주얼 C 언어가 사용되었다. 시스템의 기능 점검을 위하여 PC에서는 리더를 통해 태그 주소를 인지하고, 메모리에 데이터를 읽고 쓰는 기능을 첨가하여 900MHz 대역의 RFID 교육용 소프트웨어 시스템을 구성하였다. This paper presents the development of RFID educational system based on using 900MHz air interface between the reader and the active tag. The software of reader and the active tag is developed on embedded environment, and the software of PC controlling the reader is based on window OS operated as the server. The AT89C51ED2 VLSI chip is used for the processor of the reader and the active tag. As the development environment, Keil compiler is used for the reader and the active tag of which the programming language is C. The visual C language of the visual studio on the PC activated as the server is used for development language. To verify the function of the system, PC gets the tag`s identification number through the reader and send the data to write the active tag memory a certain content as "write" operation . Finally the data written from the active tag`s memory is sent to the PC via the reader as "read" operation and compare the received data with one already sent to the tag.

LIGA-like 공정을 이용한 마이크로 부품 복제용 Ni과 Ni-W 금형 제조 및 특성

황완식,박준식,강영철,조진우,박순섭,이인규,강성군,Hwang, W.S.,Park, J.S.,Kang, Y.C.,Cho, J.W.,Park, S.S.,Lee, I.G.,Kang, S.G. 한국재료학회 2003 한국재료학회지 Vol.13 No.1

Electroplated Ni and Ni-W micro-molds using LIGA-like process for replication of micro-components such as microfluidic parts and micro optical parts have been investigated. In general, it is hard to produce micro-parts using conventional mechanical processes. Micro-mold formed by LIGA-like process could fabricate micro-parts with high aspect ratio. In this paper, fabrication and properties of electroplated Ni molds with varying applied current types as well as those of Ni-W molds were investigated. Ni molds fabricated under pulse-reverse current showed the highest hardness value of about 160 Hv. Ni-W molds showed the hardness of about 500 Hv which was much harder than that of Ni electroplated molds. The above results suggested that high quality micro-molds could be fabricated by using Ni electroplating of pulse-reverse type for core molds and sequential Ni-W alloys coating.

한우 c-fos 유전자의 염기서열 및 발현분석

유성란,정행진,정기철,이준헌,조규완,최재관,나기준,상병찬 한국동물자원과학회 2003 한국축산학회지 Vol.45 No.6

Cellular FOS(c-fos) protein is a transcription factor that forms heterodimers mostly with c-jun family and stimulates the transcription of genes containing AP-1 regulatory elements. This c-fos expression can control growth and differentiation of various precursor cells including myoblasts. The controls by c-fos gene have been identified for affecting skeletal muscle fiber traits which are the key determinants of meat quality in pigs. As a first step for identifying the relationship between c-fos gene and meat quality traits in cattle, we fully sequenced 1,443 bp of Hanwoo c-fos mRNA and analyzed expression patterns from various organs and muscle tissues. The sequence identities of Hanwoo c-fos with that of human, pig and mouse showed 89.8%, 93.3% and rib muscle from 7 organs and 9 different parts of muscles investigated. These results presented here can be used as a valuable marker for meat quality related traits in cattle with further verification.

Characterization of Insertional Variation of Porcine Endogenous Retroviruses in Six Different Pig Breeds

Jung, W.Y.,Yu, S.L.,Seo, D.W.,Jung, K.C.,Cho, I.C.,Lim, H.T.,Jin, D.I.,Lee, Jun-Heon Asian Australasian Association of Animal Productio 2012 Animal Bioscience Vol.25 No.10

Pigs may need to be exploited as xenotransplantation donors due to the shortage of human organs, tissues and cells. Porcine endogenous retroviruses (PERVs) are a significant obstacle to xenotransplantation because they can infect human cells in vitro and have the potential for transmission of unexpected pathogens to humans. In this research, 101 pigs, including four commercial breeds (23 Berkshire, 13 Duroc, 22 Landrace and 14 Yorkshire pigs), one native breed (19 Korean native pigs) and one miniature breed (10 NIH miniature pigs) were used to investigate insertional variations for 11 PERV loci (three PERV-A, six PERV-B and two PERV-C). Over 60% of the pigs harbored one PERV-A (907F8) integration and five PERV-B (B3-3G, B3-7G, 742H1, 1155D9 and 465D1) integrations. However, two PERV-A loci (A1-6C and 1347C1) and one PERV-B locus (B3-7F) were absent in Duroc pigs. Moreover, two PERV-C loci (C2-6C and C4-2G) only existed in Korean native pigs and NIH miniature pigs. The results suggest that PERV insertional variations differ among pig breeds as well as among individuals within a breed. Also, the results presented here can be used for the selection of animals that do not have specific PERV integration for xenotransplantation research.

Angular dependences of SiO₂ etch rates at different bias voltages in CF₄, C₂F₆, and C₄F₈ plasmas

Kim, J.H.,Cho, S.W.,Park, C.J.,Chae, H.,Kim, C.K. Elsevier Sequoia 2017 THIN SOLID FILMS - Vol.637 No.-

The angular dependences of SiO<SUB>2</SUB> etch rates at different bias voltages for in CF<SUB>4</SUB>, C<SUB>2</SUB>F<SUB>6</SUB>, and C<SUB>4</SUB>F<SUB>8</SUB> plasmas were investigated using a Faraday cage system. When the bias voltage was -400V, the normalized etch yields (NEYs) reached a maximum at 70<SUP>o</SUP> in CF<SUB>4</SUB> and C<SUB>2</SUB>F<SUB>6</SUB> plasmas, while they decreased monotonically with ion-incident angle in a C<SUB>4</SUB>F<SUB>8</SUB> plasma. This was because the thickness of the steady-state fluorocarbon film formed on the SiO<SUB>2</SUB> surface was minimized at an ion incident angle of 70<SUP>o</SUP> in CF<SUB>4</SUB> and C<SUB>2</SUB>F<SUB>6</SUB> plasmas, while much thicker fluorocarbon films were deposited in a C<SUB>4</SUB>F<SUB>8</SUB> plasma. When the bias voltage was as high as -1200V, the thicknesses of the steady-state fluorocarbon films were very thin (less than 2A) and nearly unchanged at all ion-incident angles for CF<SUB>4</SUB> and C<SUB>2</SUB>F<SUB>6</SUB> plasmas, resulting in nearly the same shape of the NEY curves. In a C<SUB>4</SUB>F<SUB>8</SUB> plasma, the NEY showed a maximum at an ion-incident angle of 50<SUP>o</SUP> because the thickness of the steady-state fluorocarbon film was minimized at this angle.

Data Build-up for the Construction of Korean Specific Greenhouse Gas Emission Inventory in Livestock Categories

Won, S.G.,Cho, W.S.,Lee, J.E.,Park, K.H.,Ra, C.S. Asian Australasian Association of Animal Productio 2014 Animal Bioscience Vol.27 No.3

Many studies on methane ($CH_4$) and nitrous oxide ($N_2O$) emissions from livestock industries have revealed that livestock production directly contributes to greenhouse gas (GHG) emissions through enteric fermentation and manure management, which causes negative impacts on animal environment sustainability. In the present study, three essential values for GHG emission were measured; i.e., i) maximum $CH_4$ producing capacity at mesophilic temperature ($37^{\circ}C$) from anaerobically stored manure in livestock category ($B_{0,KM}$, Korean livestock manure for $B_0$), ii) $EF_{3(s)}$ value representing an emission factor for direct $N_2O$ emissions from manure management system S in the country, kg $N_2O-N$ kg $N^{-1}$, at mesophilic ($37^{\circ}C$) and thermophilic ($55^{\circ}C$) temperatures, and iii) $N_{ex(T)}$ emissions showing annual N excretion for livestock category T, kg N $animal^{-1}$ $yr^{-1}$, from different livestock manure. Static incubation with and without aeration was performed to obtain the $N_2O$ and $CH_4$ emissions from each sample, respectively. Chemical compositions of pre- and post- incubated manure were analyzed. Contents of total solids (% TS) and volatile solid (% VS), and the ratio of carbon to nitrogen (C/N) decrease significantly in all the samples by C-containing biogas generation, whereas moisture content (%) and pH increased after incubation. A big difference of total nitrogen content was not observed in pre- and post-incubation during $CH_4$ and $N_2O$ emissions. $CH_4$ emissions (g $CH_4$ kg VS-1) from all the three manures (sows, layers and Korean cattle) were different and high C/N ratio resulted in high $CH_4$ emission. Similarly, $N_2O$ emission was found to be affected by % VS, pH, and temperature. The $B_{0,KM}$ values for sows, layers, and Korean cattle obtained at $37^{\circ}C$ are 0.0579, 0.0006, and 0.0828 $m^3$ $CH_4$ kg $VS^{-1}$, respectively, which are much less than the default values in IPCC guideline (GL) except the value from Korean cattle. For sows and Korean cattle, $N_{ex(T)}$ values of 7.67 and 28.19 kg N $yr^{-1}$, respectively, are 2.5 fold less than those values in IPCC GL as well. However, $N_{ex(T)}$ value of layers 0.63 kg N $yr^{-1}$ is very similar to the default value of 0.6 kg N $yr^{-1}$ in IPCC GLs for National greenhouse gas inventories for countries such as South Korea/Asia. The $EF_{3(s)}$ value obtained at $37^{\circ}C$ and $55^{\circ}C$ were found to be far less than the default value.