선진복합재료 적층판의 동적 층간 파괴 인성평가

김지훈,양인영,김영남,심재기 한국산업안전학회 1998 한국안전학회지 Vol.13 No.4

In this paper, an investigation was performed on the dynamic interlaminar fracture toughness of CFRP(carbon fiber reinforcement plastics) composite laminates. Composite laminates used in this experimentation are CF/EPOXY and CF/PEEK laminated plates. In the experiments, Split Hopkinson's Bar(SHPE) test was applied to dynamic and notched flexure test. The mode II fracture toughness of each unidirectional CFRP was estimated by the analyzed deflection of the specimen and J-integral with the measured impulsive load and reactions at the supported points. As an experimental result, the vibration amplitude of CF/PEEK laminates appear more than that of CF/EPOXY laminates for the J-integral and displacement velocity at a measuring point. Also, it is thought that the dynamic. fracture toughness of two kind specimens(CFRP/EPOXY and CF/PEEK) with the in crease of displacement velocity becomes a little greater at a measuring point within the range of measurement.

다른 광물질과 혼합된 크롬 피콜린산 급여가 비육돈의 성장 , 도체특성 , 혈액성상에 미치는 영향

김지훈,한인규,김진동,김대성,양종석,손현수,현영 한국영양사료학회 1999 韓國營養飼料學會誌 Vol.23 No.5

본 시험은 여러 가지 광물질과 혼합된 크롬 피콜린 산을 첨가한 사료의 급여가 비육돈의 성장, 도체특성, 혈액성상에 미치는 영향을 알아보기 위하여 수행되었다. 개시체중이 69㎏인 총 513두의 비육돈을 돈방당 16∼21두씩 수용하여 사양시험을 수행하였으며, 9마리가 대사시험에 사용되었다. 처리구는 2개의 단백질 수준별 대조구 (Con 12, Cen 14)와 외산 크롬 피콜린산 (CrP-CaCO₃ ; Prince사 제품). 크롬 제오라이트 (CrP-Zeolite 12, 14), 국산 크롬 피콜린산 1 (CrP-CaCO₃; KIST 개발), 크롬 피콜린산-산화아연 (CrP-CaCO₃-ZnO 12, 14) 그리고 국산 크롬 피콜린산 2 (CrP-CaCO₃ ; M. H. Lee 개발)이었다. 성장성적에 있어서는 일당중체량, 일당사료섭취량, 사료효율 등 모든 조사항목에서 처리구간의 차이가 발견되지 않았으나, 등지방 두께는 크롬 피콜린산 첨가에 의해 감소하는 경향이 발견되었고, 이러한 경향은 출하체중이 무거울수륵 뚜렷하게 나타났다. 도체등급은 크롬 제오라이트구와 크롬 피콜린산-산화아연처리구에서 높게 나타났으며, 혈액내 콜레스테를의 함량도 크롬 제오라이트구와 크롬 피콜린산-산화아연처리구에서 대조구에 비해 유의적으로 감소하였다 (p<0.05). 크롬 피콜린산-산화아연처리구와 크롬 피콜린산구에서 건물 및 단백질 소화율이 향상되었다 (p<0.05). This experiment was conducted to investigate the effects of chromium picolinate in different combinations with minerals on growth, carcass characteristics, serum traits and nutrient digestibility in finishing pigs. Five-hundred and thirteen pigs (69.0 ㎏ of initial weight) were assigned to 9 treatments, each containing three replicates of sixteen to twenty-one pigs each. Additional nine pigs were used in a digestion trial. Treatments were two controls (12% CP and 14% CP), foreign CrP-CaCO₃, two CrP-Zeolite (12% CP and 14% CP), domestic CrP-CaCO₃ 1, CrP-CaCO₃-ZnO (12% CP and 14% CP) and domestic CrP-CaCO₃ 2. ADG was not significantly different among the treatments. Tenth rib backfat thickness tended to be decreased by feeding diet with CrP. Carcass grade was improved by using zeolite and CaCO₃ + ZnO along with CrP in diets. Serum cholesterol level was significantly reduced by feeding diets containing CrP with CaCO₃ + ZnO or Zeolite compared with the control. Supplementation of Cr with CrP-CaCO₃ + ZnO or CrP-CaCO₃ in diets significantly improved the digestibility of crude protein and dry matter (p<0.05). The excretion of nitrogen was lower in pigs fed diets containing Cr regardless of the combinations with minerals. The excretion of phosphorus was lowest in the CrP-CaCO₃ + ZnO group which showed the highest phosphorus digestibility.

크롬 피콜린산 또는 카르니틴이 첨가된 사료급여가 비육돈의 성장 및 도체특성에 미치는 영향

김지훈,한인규,김대성,배극환,양종석,손현수,현영 한국영양사료학회 1999 韓國營養飼料學會誌 Vol.23 No.5

본 시험은 여러 가지 광물질과 혼합된 크롬 피콜린산이나 카르니틴을 첨가한 사료의 급여가 비육돈의 성장 및 도체특성에 미치는 영향을 조사하기 위하여 실시되었다. 평균체중 60.69±1.11 kg인 삼원교잡종 (Yorkshire×Landrace×Duroc) 비육돈 암수 180마리를 대조구, CFC{CrP + Fe₂O₃ + CaCO₃}, CFZC{CrP + Fe₂O₃ + ZnO + CaCO₃}, CZC-1 {CrP (1/300) + ZnO(9/300) + CaCO₃(290/300)}, CZC-2(CrP(1/300) + ZnO(14/300) + CaCO₃ (285/300)} 그리고 카르니틴구 등 6처리구에 성별로 배치하였다. 크롬 피콜린산이나 카르니틴에 의한 성장개선은 발견되지 않았다. 수퇘지에 있어서는 CFZC 처리구가 CZC-2 처리구보다 유의적으로 사료효율이 좋았다 (p<0.05). 도체특성에 있어서도 전체적으로 처리구간의 유의적인 차이는 발견되지 않았으나, 수퇘지에서는 CFZC 처리구가 대조구에 비해 등지방두께가 않았고 (p<0.05), 가장 좋은 도체등급은 CZC-2 처리구에서 나타났다. A study was conducted to investigate the effect of feeding diets containing chromium picolinate (CrP) or carnitine on growth and carcass characteristics in finishing pigs. A total of 180 cross bred pigs (Yorkshire x Landrace x Duroc; initial body weight of 60.7±1.1 kg) were assigned to 6 treatments : Control, CFC{CrP + Fe₂O₃ + CaCO₃}, CFZC{CrP + Fe₂O₃ + ZnO + CaCO₃}, CZC-1 {CrP (1/300) + ZnO(9/300) + CaCO₃(290/300)}, CZC-2(CrP(1/300) + ZnO(14/300) + CaCO₃ (285/300)} and camitine. No significant improvement was found in average daily gain (ADG), average daily feed intake (ADFI), and feed/gain ratio (F/G) by feeding diets containing chromium picolinate. The feed efficiency of male pigs fed with CFZC was better than pigs fed CZC-2 diet during the entire period (p<0.05). No differences were found in carcass characteristics between treatments expect that backfat thickness was reduced in male pigs fed the CFZC diet compared to the control (p<0.05). The best carcass grade was found in pigs fed CZC-2 the diet.

2 차원 정현파 가진을 받는 강체블록의 록킹진동에 있어서의 카오스 : 미끄럼이 없는 경우에 대하여 In the Case of No Sliding Occurrence

김지훈,김정호,양인영,정만용,양광영 한국산업안전학회 1999 한국안전학회지 Vol.14 No.2

This research deals with the non-linearities associated with impact and sliding for the rocking behavior of rigid block subjected to two dimensional excitation of horizontal and vertical direction. The non-linearities examined of impact between block and base: The transition of two governing rocking equations, the abrupt reduction in kinetic energy associated with impact. In this study, the rocking vibration system of two types are considered for several friction condition. One is the undamped rocking vibration system, disregarding energy dissipation at impact and the other is the damped rocking system, including energy dissipation at impact. The response analysis by non-dimensional rocking equation is carried out for the change of excitation amplitude. The chaos responses were discovered in the wide response region, particularly, in the case of high vertical excitation and their chaos characteristics are examined by Poincare map, power spectra and Lyapunov Exponent. The complex behavior of chaos response, in the phase space, were illustrated by Poincare map. Therefore, Poincare map will be a significant material in order to understand chaos of rocking system.

수평방향의 정현파 가진을 받는 강체 블록의 비선형 로킹진동특성

김지훈,김정호,양인영,정낙규,정만용 한국산업안전학회 1999 한국안전학회지 Vol.14 No.4

This research concentrates on the influence of non-linearities associated with impact for the nonlinear rocking behavior of rigid block subjected to one dimensional sinusoidal excitation of horizontal direction. The transition of two governing rocking equations, the abrupt reduction in the kinetic energy associated with impact, and sliding motion of block. In this study, two type of rocking vibration system are considered. One is the undamped rocking vibration system, disregarding energy dissipation at impact and the other is the damped rocking system, including energy dissipation and sliding motion. The response analysis using non-dimensional rocking equation is carried out for the change of excitation parameters and friction coefficient. The chaos responses were discovered in the wide response region, particularly, for the case of high excitation amplitude and their chaos characteristics were examined by the time history, Poincare map, power spectra and Lyapunov Exponent of rocking responses. The complex behavior of chaos response, in the phase space, were illustrated by Poincare map. The bifurcation diagram and Poincare map were shown to be effective in order to understand chaos of rocking system.

Cu-Al-Ni-Ti-Mn 합금의 변태특성 및 기계적 성질에 미치는 가공열처리의 영향

강조원,장우양,양권승,이영수,곽사호,김춘동,백승남 한국열처리공학회 1999 熱處理工學會誌 Vol.12 No.2

The distribution of the second phase, the change of transformation temperature and mechanical properties with thermomechanical treatment conditions were investigated by metallography, calorimetry, EDS, tensile test and fractography in a Cu-Al-Ni-Ti-Mn alloy. The cast structure revealed Ti-rich precipitates(X_L phase) between dendrite arms, which have been identified as (Cu,Ni)₂TiAl intermetallic compounds. By homogenizing above 900℃, the X_L phase was melted in the matrix, while the X_s phase was precipitated in matrix and the volume fraction of it was increased. When hot-rolled specimen was betatized below 750℃, recrystallization could not be observed. However, the specimen betatized above 800℃ was recrystallized and the grain size was about 50㎛, while X_s phase was precipitated in matrix. With raising betatizing temperature, M_s and A_s temperatures were fallen and transformation hysteresis became larger. The strain of the specimen betatized at 800℃ was 8.2% as maximum value. The maximum shape recovery rate could be obtained in the specimen betatized at 800℃ but it was decreased due to the presence of X_s phase with increasing betatizing temperature.

Malic acid 와 Citric acid 의 첨가가 반추위 곰팡이의 성장 및 섬유소 분해율에 미치는 영향

고주,이성실,노영애,김홍대,하종규,양승학 한국영양사료학회 1999 韓國營養飼料學會誌 Vol.23 No.3

본 실험은 처음으로 malic acid와 citric acid의 첨가가 곰팡이의 성장 및 섬유소 분해력에 미치는 영향을 관찰하였고 혼합 미생물의 성장 및 대사에 미치는 영향을 구명하고자 실험 1, 2, 3으로 나누어 수행하였는데, malic acid의 농도가 배지의 0.001%∼0.01%까지는 곰팡이의 성장 및 섬유소 분해효소의 활력과 섬유소 분해율을 증가시켰다. 그러나 0.1% 이상의 malic acid를 첨가하면 오히려 곰팡이의 성장이나 섬유소 분해효소 및 섬유소 분해력이 떨어지는 것으로 나타났다. 그리고 citic acid를 배지의 0.005% 첨가했을 때 곰팡이의 성장량과 섬유소 분해효소의 활력 및 섬유소 분해율이 대조구에 비하여 유의적으로 증가하였으며 0.1%에서는 크게 억제되는 것으로 나타났다 This study was conducted to evaluate the effects of malic or citric acid supplementation on the growth and cellulolytic activity of rumen fungi. Malic acid or citric acid were supplemented into Lowe's medium at the level of 0.001, 0.005, 0.01, 0.05 and 0.1%, respectively. N. frontalis was used as inoculant. Incubation was lasted for 1, 2, 3, 5 and 7 days and pH, CMCase and xylanase activity, filter paper degradability and fungal protein were estimated after incubation. When supplementation level was from 0.001 to 0.01%, malic acid stimulated the fungal growth, cellulolytic enzymes activity and cellulose degradability, but results were reversed when malic acid concentration was above 0.1%. Citric acid affected rumen fungal growth and cellulolytic enzyme activity in the similar trend. .

혼성 Cresol 과 POCl3 의 반응에 의한 tri - Cresyl Phosphate 의 분리공정 연구

이상석,김장규,원성호,양승남,김남기 한국산업안전학회 1998 한국안전학회지 Vol.13 No.2

Tri-cresyl phosphate(TCP) was synthesized by reaction of phosphorus chloride with mixed cresol(mixture of m-cresol, p-cresol,and others) in the presence of AlCl₃. Some of unwanted products and unreactants colored TCP. In order to separate TCP from these, vaccume distillation was carried twice, but colorless TCP could not be producted. Separation of unwanted materials by 2% NaOH solution was introduced before first and second distillation and optimal separation conditions such as NaOH concentration, mixing volume ratio, mixing time, and rpm were investigated for new batch separation and production of colorless TCP. Optimal conditions were 2% NaOH solution, 36% mixing volume ratio of 2% NaOH solution, 1.5 hours of mixing time, and 20 rpm.

한글 WORD PROCESSOR 에 관한 연구

김현욱,김덕진,양정윤,김낙빈,김영천,이순흠 고려대학교 공학기술연구소 1984 고려대학교 생산기술연구소 생기연논문집 Vol.20 No.1

A Hanguel word processing software which could be ported into a general purpose microcomputer that has Z-80A CPU and FDOS operating system has been described in this paper. This software consists of input routine, processing routine, and output routine. In the input routine, Hanguel inputted linearly by the ASCII keyboard is combined into a character, and is displayed on the CRT screen in two-dimensional form. In the processing routine, any function among (1) editing (2) updating (3) printing (4) deleting could be selectively performed. In the output routine, Hanguel characters could be selectively printed in the 3 different sized character forms, i.e., 16×16 dot, 24×24 dot, and 32×32 dot size.

낙추식 충격시험에 의한 CFRP 적층판의 강도평가에 관한 연구

양인영,이정주,박노식 한국산업안전학회 1999 한국안전학회지 Vol.14 No.3

In this study, a drop-weight impact tester was manufactured to assess the strength of CFRP laminate plates. The tests were conducted on several laminates of different ply orientation. A system for the impact strength of CFRP laminates was made considering stress wave propagation theory using drop-weight impact tester as one of impact test. Results indicate that absorbed energy of quasi-isotropic specimen, having four interfaces is higher than that of orthotropic laminates with two interfaces. Absorbed energy in the specimen that ply number, interface number and fiber stacking sequences is same but having hybrid is higher than that of orthotropic laminates without hybrid.