Comparison of the Incidences of Selected Events Performed by Youth Players in Regulation and Modified Soccer Games

( Eugene W. Brown ),( David M. Wisner ),( Anthony Kontos ) 한국스포츠정책과학원(구 한국스포츠개발원) 2000 International Journal of Applied Sports Sciences Vol.12 No.1

Videotape data were collected on youth soccer games played under two conditions: 11 players per side on α regulation field and 7 players per side on α smaller field. Multivariate analysis of variance (MANOVA) was used to analyze selected incidences of events per ten minutes of game time per field player. Comparisons were made between the two field/player combinations, between boys and girls, and between second-grade and fourth-grade players. Significant differences were found between regulation and modified play (F(3,16)=47.93, p=0.004), with nearly all measures for modified play being significantly greater, suggesting that modified play offers greater exposure to game events and thus greater opportunity for learning and skill development. No significant differences were found between boys and girls (F(3,16)= 4.86, p=0.109). Significant differences were found between second-grade and fourth-grade players (F(3,16)=60.49, p=0.003), mostly favoring older players. The amount of time the ball remained in play was also analyzed. Under both field/player combinations the ball remained in play less than 60 percent of the total game time.

프레팅 피로 균열 발생

허용학(Yong-Hak Huh),R.E Edwards,M.W. Brown,E.R. de los Rios 대한기계학회 2002 대한기계학회 춘추학술대회 Vol.2002 No.3

Governing parameters on location of crack Initiation and direction of crack initiation were investigated by performing fretting fatigue tests and analysis on Al 2024-T351. Fatigue tests were carried out using biaxial fatigue machine. It was shown that the dominant fatigue crack tended to initiate at the outer edge of one of the four bridge pads, growing at an angle beneath a pad, before turing perpendicular to the orientation of the axial load. Distribution of stresses generated during fretting fatigue loading along the interface was calculated by elastic FE simulation. It can be known that the location of crack initiation can be predicted by using the maximum tangential stress range or the maximum shear stress range. Futhermore, the crack initiation direction can be predicted by a maximum tangential stress range.

Discovery of betulinic acid as a selective inhibitor of human melanoma that functions by induction of apoptosis

Pisha, Emily,Chai, Heesyung,Lee, Ik Soo,Changwedera, Tangai E.,Farnsworth, Norman R.,Cordell, Geoffrey A.,Beecher, Christopher W.W.,Fong, Harry H. S.,Kinghorn, A.Douglas,Brown, Daniel M.,Wani, Mansukh 전남대학교 약품개발연구소 1996 약품개발연구지 Vol.4 No.1

알루미늄 합금에서의 프레팅 피로 거동 : 접촉 재료에 따른 비교

허용학(Yong-Hak Huh),R.E. Edwards,M.W. Brown,E.R. de los Rios 대한기계학회 2002 대한기계학회 기타 간행물 Vol.2002 No.11

Comparative adsorption–regeneration performance for newly developed carbonaceous adsorbent

H.M.A. Asghar,S.N. Hussain,N.W. Brown,E.P.L. Roberts 한국공업화학회 2019 Journal of Industrial and Engineering Chemistry Vol.69 No.-

A proprietary adsorbent material called Nyex 1000 was developed by the Arvia Technology Ltd. (UK based waste water treatment company). Nyex 1000 was being employed for a number of commercial applications dealing with the removal of organic contaminants from industrial effluents. This adsorbent material had small adsorptive capacity. With the aim to address small adsorptive capacity, a new graphite based adsorbent material was developed. The particle design was accomplished through successive chemical, thermal and mechanical treatments of raw graphite material (natural large flake graphite, to be called here as NLFG). The chemical treatment of the NLFG was carried out through electrochemical intercalation using dilute (50%) sulfuric acid in an electrochemical cell. Chemically treated NLFG then went through thermal treatment at 850 °C and followed by mechanical treatments consisting of compression (4536 kgf cm−2) and chopping at 18,000 rpm for 30 s. The developed adsorbent material, (exfoliated compacted graphite, to be called here as ECG) and NLFG were characterized using state of the art techniques including SEM, BET surface area, XRD, Zeta potential, Boehm surface titration, bed electrical conductivity and laser size analysis. The characterization results showed significant increase in internal specific surface area from 1 to 17 m2 g−1. It was attributed to the development of partially porous particle surface verified by SEM results. The XRD, Boehm surface titration, Zeta potential results endorsed the associated chemical and physical changes appeared in the composition of the NLFG as a result of chemical, thermal and mechanical treatments. Adsorption-regeneration studies were conducted using developed ECG and existing Nyex 1000 materials. The pollutants used for adsorption–regeneration studies were acid violet 17, phenol, humic acid, ethane thiol and methyl propane thiol dissolved in aqueous solution. The results were compared and it was found that ECG showed significantly improved adsorption capacity with many folds. Both adsorbent materials, ECG and Nyex 1000 delivered 100% electrochemical regeneration efficiencies.

Microstructure development and properties of alumina-Ti aluminide interpenetrating composites

Ching Zen Han,Ian W.M. Brown,D.L. Zhang 한국물리학회 2006 Current Applied Physics Vol.6 No.3

Interpenetrating phase Al2O3Ti3Al composites have been fabricated by reaction sintering of 2 and 4-h discus milled composite pow-ders containing Al and TiO2 using controlled heat-treatment in non-oxidizing atmospheres. Pressureless sintering and hot pressing of thepowders has been carried out under vacuum and argon at temperatures between 1278.C and 1500 .C and a heating rate of 5.C/min.pressing compared to pressureless sintering.The microstructure development and mechanical properties of dense Al2O3Ti3Al composites fabricated by hot pressing of AlTiO2powder blends were examined. Fully dense microstructures could be achieved by hot pressing at 1387.C under vacuum. An increase ofVickers hardness was observed with increasing temperature, which can be attributed to the increase of density and the decrease in the2O3particle size and porosity level. Fracture toughness of 6.3 ± 0.8 MPa m1/2 and Vickers hardness of 13.6 ± 0.4 GPa were achieved forthe fully dense composite produced by hot pressing discus milled powder.

Seed Potato Certification in Korea

La Yong-Joon,Franckowiak J. D.,Brown W. M. Korean Society of Applied Entomology 1977 한국식물보호학회지 Vol.16 No.3

한국에서 감자의 여러 가지 감수요인중 가장 중요한 것은 각종병해인데, 이 가운데에서도 특히 바이러스 병인 모자이크병과 잎말림병에 의한 수량감소가 가장 큰 것으로 보인다. 한국에서는 무병 건전한 씨감자를 생산해서 농민에게 보급할 목적으로 1961년에 고랭지시험장에서 씨감자 검역사업이 시작되었다. 본고에서는 현재 우리나라에서 시행되고 있는 춘작용 보급종 씨감지(남작품종)의 생산개황을 설명하였다. 1976년도에는 대관령에 있는 2개 씨감자 생산조합회원들에 의해 약 1마톤 (M/T)의 보급종 남작 씨감자가 생산되어 농수산부의 종자보급소를 통해 농민에게 공급되었고, 이들 보급종 씨감자의 검역은 국립농산물검사소 검사원들이 실시하였다. 보급종 씨감자는 단위수량에 있어서 농민들이 자 채종해서 재배하는 씨감자를 월등히 능가하지만, 1976년도의 경우 보급종씨감자의 절대생산량부족으로, 급량은 소요량의 1/5에 불과하였다. 한편 추작용 상품종인 "시마바라"의 보급종은 한국에서 생산되지 않고 있다. 바이러스병에 걸린 씨감자를 심으면 아무리 맥배 리를 잘해도 수량의 증대는 기대할 수 없다. 따라서 단위수량의 제고는 농민들이 보다 우량한 씨감자를 심어야만 이루어질 수 있으며, 그러기 위해서는 현재 씨감자 공급량을 2-3배로 증가해야 한다. 현재의 부족되는 보급종 씨감자의 공급량을 충족시키기 위해서는 씨감자의 재배면적확대와 씨감자 생포장에서의 단위수량증대가 이루어져야 한다. 한국에서는 씨감자생산에 적당한 고랭지가 많이 있으며, 고랭지 이외의 곳에서도 우량한 씨감자는 생산될 수 있다. 우량씨감자의 보급과 재배법의 개선은 감자의 단위량을 크게 증대시킬 것이다. 한편 고랭지시험장에서 생산되고 있는 원원종씨감자의 질을 향상시키기 위해 최근에 개발된 몇가지 새로운 재배기술을 활용해봄직하다. 또한, 무병 건전한 신품종의 씨감자가 신속히 농민에게 보급될 수 있도록 현행 씨감자 검역제도는 개선되어야 한다. Potato diseases, especially mosaics and leaf roll, appear to reduce potato yield in Korea more than any other factor. A seed potato certification program was established at the Alpine Experiment Station (AES) in 1961 to produce high quality seed potatoes for distribution to Korean farmers. The present program for production of certified seed of Namjak (Irish Cobbler), the only variety recommended for spring plantings, is outlined. In 1976, approximately 10,000 MT of certified grade Namjak seed was produced by members of two Seed Producers Cooperatives in the Daekwanryeong area for distribution by the Office of Seed Production and Distribution (OSPD). The seed was inspected and certified by officers of the National Agricultural Products Inspection Office (NAPIO). Although the quality of the certified seed is far superior to that used by many farmers, the supply planted less than 1/5 of the 1977 potato crop. Certified seed of Shimabara, the variety recommended for autumn plantings, is not produced in Korea. The yield response of virus infected seed to improved cultural practices is poor. Therefore, an increase in potato acreage and yields appears to be possible only if more good quality seed is used by Korean farmers. A two or three fold increase in seed supply would be desirable. The volume of seed could be increased by expanding the production area and by improving yield in seed fields. More land is available in the alpine area and good seed potatoes could be grown in other parts of Korea. Planting better quality seeds and using better cultural pracitces would improve seed yields. Several techniques could be used to improve the quality of elite seed produced at AES. Changes in seed potato certification program should be made so that healthy seed stocks of new varieties can be released rapidly.

Third-Order Nonlinear Susceptibility and Hyperpolarizability of CdSe Nanocrystals with Femtosecond Excitation

Seongmin Ma,JaeTae Seo,A. Jackson,B. Tabibi,H. Brown,K. Lee,L. Creekmore,M. Namkung,Q. Yang,R. Battle,S. S. Jung,T. Skyles,W. Yu 한국물리학회 2006 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.48 No.6

Single beam femtosecond Z-scan spectroscopy at 775 nm revealed that the effective third-order nonlinear susceptibility and hyperpolarizability of CdSe colloidal nanocrystals near the Bohr radius were 0.7 . 1.0 × 10.22 m2/V2 and 0.18 . 2.0 × 10.44 m5/V2, respectively. The non-resonant nonlinearity increase for CdSe colloidal quantum dots with bigger than average diameters is attributed to their absorption cross-section being larger and their bandgap energy being narrower than those of the quantum dots with smaller sizes.

Structural and thermal characterisation of nanostructured alumina templates

I.W.M. Brown,M.E. Bowden,T. Kemmitt,K.J.D. MacKenzie 한국물리학회 2006 Current Applied Physics Vol.6 No.3

Nanostructured anodic aluminium oxide materials containing a two dimensional array of high aspect ratio aligned pores of 200 nm.C. Thermal analysis shows two discrete irreversible exothermic eventsat 850.C and 1020 .C. XRD and27Al MAS NMR show the progressive development of local and long range order in the heated struc-tures and indicate a reaction sequence of amorphous Al2O3 ! h-Al2O3 ! a-Al2O3 (corundum). NMR shows the co-existence of alumin-ium in 4, 5 and 6-coordinated sites through most of the heating sequence until the stable (6-coordinated) corundum phase is established.Phosphorus impurities incorporated during the membrane fabrication process crystallise as an AlPO4 phase above 850 .C and play animportant role in directing the chemical, physical and structural outcomes of the heat treatment.

Fabrication, microstructure and properties of Fe-TiC ceramic-metal composites

I. W. M. Brown,W. R. Owers 한국물리학회 2004 Current Applied Physics Vol.4 No.2-4

Ceramic–metal composites based on the Fe–TiC system can be synthesised by reduction of the mineral ilmenite (FeTiO3) with carbon in flowing argon or under vacuum in the temperature range 1100–1400 C. The ratio of Fe:TiC can be controlled through adjustment of the reactant materials, as can the addition of alloying metals such as Co, Cr or Ni. Dense bodies formed by sintering Fe–TiC powders displaya microstructure of uniformlydispersed TiC grains in a continuous metal matrix. The grain size of the TiC can be controlled between 1 and 20 lm byvary ing the heat treatment schedules. Hardness values of 14 GPa can be achieved through pressureless sintering of unalloyed Fe:3TiC bodies. Technologies have been developed for fabricating a range of compositions from 6 wt% to over 80 wt% TiC in iron alloymatrices, leading to broad suite of potential industrial applications as wear parts or cutting ools.