Interested Transactions By Corporate Directors : A Weakening of the Fiduciary Duty of Loyalty

Holtz, Richard W. 東國大學校 大學院 法學科 商事法 2001 商事法 세미나 Vol.10 No.-

Suppression of Time-Varying Resonances in the Power Supply Line of AC Locomotives by Inverter Control

JOACHIM HOLTZ,JENS ONNO KRAH 전력전자학회 1992 ICPE(ISPE)논문집 Vol.1992 No.4

Sources of Variability in Children's Problem Solving

Patricia D. Stokes,Danielle Holtz,Tracey Massel,Alison Carlis,Jessica Eisenberg 대한사고개발학회 2008 The International Journal of Creativity & Problem Vol.18 No.2

Variability is defined as the number of different ways in which something is done. Adaptive variability reflects varying in correct ways; error variability, in incorrect ways. This study examined two sources of variability in children’s problem solving: age and reinforcement. First, third, and fifth graders at a suburban, public elementary school played a computer maze game with increasing variability requirements. Baseline variability levels were higher in fifth- than in first-graders. These differences disappeared when variability was required. Error scores increased with variability requirements, but were higher in first- than in third- or fifth-graders. Older students used more efficient strategies than younger ones. Students with high variability and low error scores shared response patterns and strategies, regardless of grade. Pedagogical implications of age and reinforcement effects are discussed.

Carcass Characteristics and Meat Quality of Swamp Buffaloes (Bubalus bubalis) Fattened at Different Feeding Intensities

Lambertz, C.,Panprasert, P.,Holtz, W.,Moors, E.,Jaturasitha, S.,Wicke, M.,Gauly, M. Asian Australasian Association of Animal Productio 2014 Animal Bioscience Vol.27 No.4

Twenty-four male 1-year old swamp buffaloes (Bubalus bubalis) were randomly allocated to 4 groups. One group grazed on guinea grass (GG) and another on guinea grass and the legume Stylosanthes guianensis (GL). The other two groups were kept in pens and fed freshly cut guinea grass and concentrate at an amount of 1.5% (GC1.5) and 2.0% (GC2.0) of body weight, respectively. The effect of the different feeding intensities on carcass characteristics and meat quality were assessed. The mean body weight at slaughter was 398 (${\pm}16$) kg. Average daily gain was higher in concentrate-supplemented groups (570 and 540 g/d in GC1.5 and GC2.0, respectively) when compared to GG (316 g/d) and GL (354 g/d) (p<0.01). Likewise, the warm carcass weight was higher in GC1.5 and GC2.0 compared to GG and GL. Dressing percentage was 48.1% and 49.5% in GC1.5 and GC2.0 in comparison to 42.9% and 44.8% observed in GG and GL, respectively. Meat of Longissimus throracis from GC1.5 and GC2.0 was redder in color (p<0.01), while water holding capacity (drip and thawing loss) was improved in pasture-fed groups (p<0.05). Protein and fat content of Longissimus thoracis was higher in animals supplemented with concentrate (p<0.01), as was cholesterol content (p<0.05), whereas PUFA:SFA ratio was higher and n-6/n-3 ratio lower (p<0.01) in pasture-fed buffaloes. Results of the present study showed that the supplementation of pasture with concentrate enhances the growth and carcass characteristics of swamp buffaloes expressed in superior dressing percentage, better muscling, and redder meat with a higher content of protein and fat, whereas animals grazing only on pasture had a more favorable fatty acid profile and water holding capacity. In conclusion, the supplementation of concentrate at a rate of about 1.5% of body weight is recommended to improve the performance and carcass quality of buffaloes.

Effects of Meiotic Stages, Cryoprotectants, Cooling and Vitrification on the Cryopreservation of Porcine Oocytes

Huang, Wei-Tung,Holtz, Wolfgang Asian Australasian Association of Animal Productio 2002 Animal Bioscience Vol.15 No.4

Different factors may affect the sensitivity of porcine oocytes during cryopreservation. The effect of two methods (cooling and vitrification), four cryoprotectants [glycerol (GLY), 1, 2-propanediol (PROH), dimethyl sulfoxide (DMSO) or ethylene glycol (EG)] and two vitrification media (1 M sucrose (SUC)+8 M EG; 8 M EG) on the developmental capacity of porcine oocytes at the germinal vesicle (GV) stage or after IVM at the metaphase II (M II) stage were examined. Survival was assessed by FDA staining, maturation and cleavage following IVF and IVC. A toxicity test for different cryoprotectants (GLY, PROH, DMSO, EG) was conducted at room temperature before cooling. GV and M II-oocytes were equilibrated stepwise in 1.5 M cryoprotectant and diluted out in sucrose. The survival rate of GV-oocytes in the GLY group was significantly lower (82%, p<0.01) than that of the other group (92 to 95%). The EG group achieved a significantly higher maturation rate (84%, p<0.05) but a lower cleavage rate (34%, p<0.01) than the DMSO group and the controls. For M II-oocytes, the survival rates for all groups were 95 to 99% and the cleavage rate of the GLY group was lower than the PROH-group (21 vs 43%, p<0.01). After cooling to $10^{\circ}C$, the survival rates of GV-oocytes in the cryoprotectant groups were 34 to 51%, however, the maturation rates of these oocytes were low (1%) and none developed after IVF. For M II-oocytes, the EG group showed a significantly higher survival rate than those of the other cryoprotectant groups (40% vs 23-26%, p<0.05) and the cleavage rates of PROH, DMSO and EG group reached only 1 to 2%. For a toxicity test of different vitrification media, GV and M II-oocytes were equilibrated stepwise in 100% 8 M EG (group 1) and 1 M SUC + 8 M EG (group 2) or equilibrated in sucrose and then in 8 M EG (SUC+8 M EG, group 3). For GV-oocytes, the survival, maturation and cleavage rates of Group 1 were significantly lower than those in group 2, 3 and control group (p<0.05). For M II-oocytes, there were no differences in survival, maturation and cleavage rates between groups. After vitrification, the survival rates of GV and M II-oocytes in group 2 and 3 were similarly low (4-9%) and none of them matured nor cleaved after in vitro maturation, fertilization and culture. In conclusion, porcine GV and M II-oocytes do not seem to be damaged by a variety of cryoprotectants tested, but will succumb to a temperature decrease to $10^{\circ}C$ or to the process of vitrification, regardless of the cryoprotectant used.

Addendum < Session : Nanocrystalline Materials > : PROCESSING OF NANOCRYSTALLINE MAGNESIUM - NICKEL ALLOYS FOR HYDROGEN STORAGE

M . A . Imam,R . L . Holtz 대한금속재료학회 ( 구 대한금속학회 ) 1995 Advanced Material and Processing Vol.3 No.-

Cooling System Design in Power Electronic

Chan-Ki Kim,Hong-Woo Rhew,Yoon-Ho Kim,J. Holtz 전력전자학회 2003 전력전자학술대회 논문집 Vol.2003 No.7(2)

In this paper, heatsink design for high powei converter is presented There are many ways of designing heatsink, but air cooling is by far the most used and much more practical than any of the other methods In this paper, the practical methods of cooling which include the method to reduce a noise and a Vibration due to a fan and the method to design a gap resistance and a contact resistance due to mounting force between thyristor and heatsink is proposed Finally, simulation and experimental results are described to verify validity of the proposed method<br/>

Unconfined Compressive Strength of Soil-Cement Pavement with Recycled Red Mud

Lee Yunkyu(이윤규),Baek Seungcheol(백승철),R. D. Holtz,Jeong Dongyoung(정동영) 한국지반환경공학회 2008 한국지반환경공학회논문집 Vol.9 No.7

알루미늄 제조 시 발생하는 산업부산물인 Red mud가 첨가된 흙-시멘트 포장 재료를 개발하기 위하여 일축압축강도시험을 수행하였으며 Red mud 함유율, 시멘트 함유율, Fly ash 대체 비율 및 모래의 대체 비율이 일축압축강도에 미치는 영향을 검토하기 위하여 양생기간 7일, 14일 및 21일에 대한 공시체를 제작하였다. 시험결과, Red mud와 Fly ash 함유량이 감소할수록 시멘트 함유량이 증가할수록 일축압축강도는 증가하였고, 화강풍화잔류토를 사용할 경우 모래의 대체 비율에 따른 일축압축강도에 미치는 영향은 없는 것으로 나타났다. The unconfined compressive strength of soil-cement mixed with red mud, an industrial by-product of alumina production, was investigated in the laboratory. The investigation involved laboratory tests under the various conditions such as red mud content, cement content, fly ash content and ratio of soil replacement with sands. The unconfined compressive strength tests were performed at 7, 14 and 21 days after specimen preparation. Results of the study show that the unconfined compressive strength increased as red mud and fly ash content decreased and cement content increased. Increasing the soil replacement ratio with sands had an insignificant effect on compressive strength because the soil had a similar particle size as the replacement sands.

Predation behavior of Podisus nigrispinus on Spodoptera eridania

José Romário de Carvalho,Dirceu Pratissoli,Luis Moreira de Araujo Junior,Alixelhe Pacheco Damascena,Anderson Mathias Holtz,Leandro Pin Dalvi,Ulysses Rodrigues Vianna 한국응용곤충학회 2020 Journal of Asia-Pacific Entomology Vol.23 No.4

The behavior and effective predation time can affect the prey death in pest biological control programs. This work studied the Podisus nigrispinus (Dallas, 1851) (Heteroptera: Pentatomidae) behavior on Spodoptera eridania (Cramer, 1782) (Lepidoptera: Noctuidae) caterpillars, and its implications in case of prey escape. The preference bioassay (B1) aimed to verify the caterpillars body region (anterior: head and thorax; median and posterior) preferred by the predator and its implication in prey mortality. The predation duration bioassay considered the following effective predation times: 1, 2, 4, 8, 16, 32, 64 and 128 min; the caterpillars were removed after each predation time, to simulate prey escape, and the dead were counted until the seventh day. This experiment was performed in two ways: with randomly selected and not repeated predators (B2); and with the same predators in successive times (B3). The predator preferred to attack the caterpillars anterior region. The caterpillars mortality increased with increasing effective predation time. The mortality was 90% after 64 min under B2. This value was estimated for 16 min under B3. The P. nigrispinus prefers to attack the caterpillars anterior region and mortality of S. eridania caterpillars was favored in predators that have suffered predation interruption.