ANALYSIS OF ANGULAR MOMENTUM THE WHOLE BODY DURING GLIDE HITTING AND KICK HITTING IN BASEBALL

The purpose of this study were to analyze the biomechanical characteristics of glide and kick hitting in baseball which exerted by professional baseball players in Taiwan. Five professional baseball players were selected as the subjects. The experiment used two JVC-DV 9800 high-speed digital cameras(120 Hz).The video data was treated by Kwon3D 3.0 motion analysis system. The following are the main results: The kick hitting could get better rotation benefit and optimum. In the stride phase, angUlar momentum of the body is increasing by body inertia. In the rotation phase, the velocity increasing of the body center of gravity makes the angUlar momentum increase. The largest angular momentum appears right before the ball hi!. Because the body inertia in ball hitting moment was very small, the angUlar momentum was mainly affected by angular velocity. In the phase, the average value, largest value and hitting moment value of angular momentum with kick hitting are larger than those with glide hitting. Therefore, the kick hitting could get larger linear and angular momentum

EFFECT OF BACKPACK ON SELECTED GAIT PARAMETERS OF PRIMARY SCHOOL CHilDREN

The purpose of this study was to compare the effects of a backpack load of 15% body weight (BW) on selected gait parameters of primary school children. Ten participants were recruited from primary school (age: 10.3 ± 0.48 yrs; hI: 141.3 ± 0 .41 cm; mass: 38.1 ± 6.1 kg). A JVC 9800 (60 hz) video camera synchronized with an AMTI force plate (1200 Hz) were used to collect data. A repeated measure t-test (p < 0.05) was used for group comparisons. The backpack load did not affect either the proportionate time of the stance phase, swing phase, or the magnitude of selected vertical and anterioposterior ground reaction force parameters. However, the 15% backpack load did cause a significant increase in proportionate double leg support time

Antioxidant and tyrosinase inhibitor from Leucaena leucocephala

The experimental design is divided into two parts: chemical analysis and bioactive assay. One antioxidant lupeol (4) and one inhibition of tyrosinase pheophorbide a methyl ester (7) were identified in Leucaena leucocephala. Both showed effective 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity compared with vitamin C, and mushroom tyrosinase compared with kojic acid. These results suggest that these constituents of L. leucocephala act as natural antioxidants and play a potential role in prevention of pigmentation.Keywords: Leucaenana leucocephala, lupeol, pheophorbide a methyl ester, antioxidant, mushroom tyrosinas

Thermal Effect on Structure of Silver in Ion-Exchanged Soda-Lime Glasses and Aluminum-Doped Zinc Oxide Films

Heat treatment is commonly used during device processing in order to achieve specific functionalities of the devices. How a series of heat treatment applies to accomplish this goal can be found in the literature. However, specific properties of the devices after the treatment are more emphasized than the details of the structural modifications in the industrial applications. In this paper, it is intended to illustrate the fundamental changes in the structure due to heat treatment which result in the desired physical properties of the devices. Two study cases, Ag ion-exchanged soda-lime glasses and aluminum doped ZnO (AZO) films, were illustrated. The changes in chemical states, the structural modification during and after heat treatment are explored. By understanding how the metallic Ag formed and accumulated during annealing, an optimum heat treatment to grow the proper size and density of silver quantum dots in the films are possible. Post annealing effect on the AZO films shows that the crystallinity, the peak positions shifts, and grain sizes were changed after annealing. Both illustrated cases indicate thermally induced changes in chemical state, the stress release, and rearrangement of atoms in materials during and after annealing

Ventricular divergence correlates with epicardial wavebreaks and predicts ventricular arrhythmia in isolated rabbit hearts during therapeutic hypothermia

INTRODUCTION: High beat-to-beat morphological variation (divergence) on the ventricular electrogram during programmed ventricular stimulation (PVS) is associated with increased risk of ventricular fibrillation (VF), with unclear mechanisms. We hypothesized that ventricular divergence is associated with epicardial wavebreaks during PVS, and that it predicts VF occurrence. METHOD AND RESULTS: Langendorff-perfused rabbit hearts (n = 10) underwent 30-min therapeutic hypothermia (TH, 30°C), followed by a 20-min treatment with rotigaptide (300 nM), a gap junction modifier. VF inducibility was tested using burst ventricular pacing at the shortest pacing cycle length achieving 1:1 ventricular capture. Pseudo-ECG (p-ECG) and epicardial activation maps were simultaneously recorded for divergence and wavebreaks analysis, respectively. A total of 112 optical and p-ECG recordings (62 at TH, 50 at TH treated with rotigaptide) were analyzed. Adding rotigaptide reduced ventricular divergence, from 0.13±0.10 at TH to 0.09±0.07 (p = 0.018). Similarly, rotigaptide reduced the number of epicardial wavebreaks, from 0.59±0.73 at TH to 0.30±0.49 (p = 0.036). VF inducibility decreased, from 48±31% at TH to 22±32% after rotigaptide infusion (p = 0.032). Linear regression models showed that ventricular divergence correlated with epicardial wavebreaks during TH (p<0.001). CONCLUSION: Ventricular divergence correlated with, and might be predictive of epicardial wavebreaks during PVS at TH. Rotigaptide decreased both the ventricular divergence and epicardial wavebreaks, and reduced the probability of pacing-induced VF during TH

Studies on water soluble air-drying amino alkyd resin coatings

In this study,Three kinds of drying oils for the manufacturing water soluble air-drying alkyd resins,then blend it with a high imino methylated melamine resin crosslinker, neutralizing agents and other additives for wood coatings and then the properties of paints were investigated. The molecular weight and its distribution were determined by Gel Permeation Chromatography (GPC). The rheological properties were measured by Viscometer, and the drying time of film was obtained by drying recorder. The crosslinking reaction and weatherability were determined by Fourier Transform Infrared Spectroscopy (FTIR). Differential Scanning Calorimeter (DSC) was used to evaluate the curing kinetics. It was found that the nature of drying oils, neutralizing agents, and cosolvents would significantly influence on the molecular weight, viscosity, stability, drying time and curing kinetics of the paints. When the tung/castor oil, was used as resin generally it showed a higher molecular weight and viscosity than those using soybean or linseed oil. The diethylamine neutralizing agent for paints exhibited the best stability and lower viscosity, In contrast, ammonia exhibited lower stability. The paints which included the resin that using linseed oil,ammonia and butyl cellosolve (EGMBE), showing the fastest drying time for coating film. However, the drying time of the film was found to be significantly decreased, due to blending it with high imino methylated melamine resin. But the crosslinking peak was very weak on the FTIR plot. It was also found that below 109 ℃ during the solvent evaporation stage,the endothermic peak occurred and it would suppress the DSC exotherm associated with the autooxidation crosslinking reaction. However,the temperature was above 109 ℃,the solvent would be completely evaporated,and exothermic reaction would occur,therefore the crosslinking reaction of amino alkyd resin at high temperature would be performed.It was found that the solvent may significantly influence on thermal behavior, and it was also found that the alkyd resin with more iodine value and lower preexponential constant (InZ) and lower activation energy, generally it would have a short drying time. The physical and chemical properties of the coating film depended on the rate of evaporation and stability of the neutralizing agent and the number of unsaturated double bond and hydroxyl group of oil modified alkyd resin. The paints those including the neutralizing agent and using ammonia, showed the best film hardness and water-resistance; but the paint using diethylamine system, exhibited a higher thermal degradation than that of the other 2 kinds of neutralizing agents. Regarding the evaluation of paint which contained a drying oil, linseed oil modified resin, it had a higher film hardness. In contrast, a blend of the drying oil which soybean oil was used as modified resin, it showed both better water-resistance and thermal degradation-resistance. In addition, whatever the substrate was used as coating, it was found that the film had good flexibility after 15 cycles of cold and hot treatment. In order to qualify the weatherability, the coated wood was placed in the artificially accelerated weatherometer (enclosed carbon-arc type) for 240 hours. The paint system which included ammonia and soybean oil modified resin still maintained a higher gloss retention than that of the other formulations. In addition,the film of the coated wood appeared to have better appearance after 240 hours of exposure. According to the SRS-FTIR measurement, the absorption peak of the methoxyl group (915cm-1) and alkyl group (1376cm-1) disappeared after 240 hours of exposure. The absorption peak of the triazine ring (1556cm-1) disappeared after 268 hours, while the absorption peaks of the carbonyl group(1710cm-1, 1721cm-1) increased after 268 hours. It was found that the fastest drying time for coating film in air was the alkyd resin containing 5% trimethylol propane diallyl ether (TMPDAE). Alkyd resin containing 10% or 15% had a longer drying time, therefore it would not have any improved effect. With a relative humidity under 65% and various temperature, it was found that in creasing the temperature resulted in an increased speed of the drying of the film. It also indicated the synergism of both temperature and relative humidity in affecting the drying rate of film. The alkyd resin coating containing 5% TMPDAE in air at 50 ℃ and under 45% RH, 2 hours drying time would be required. When UV illumination was applied, the drying time was reduced to 1 hour. Under these condition, the drying time of film was 9-18 times faster than drying in air at 25 ℃ and under 65%RH condition. With a DSC experiment, it was found that increasing the TMPDAE content, resulted in an increasing in the speed of the crosslinking reaction of the film. This indicated that the synergism of temperature and TMPDAE would affect the rate of crosslinking reaction.高亞胺型甲基化三聚氰胺樹脂可作為水溶性醇酸樹脂之架橋劑，在不需添加酸觸媒下能夠調配氣乾型水性塗料。使用膠體滲透層析儀 (GPC)， 霍氏 轉換紅外線光譜儀(FTIR)，示差掃瞄熱卡儀(DSC)及其他相關儀器 ，評估 樹脂塗料系統之性質及塗膜性能，結果歸納如下： 1.樹脂塗料之分子量、黏度、穩定性、乾燥性、硬化動力學及塗膜物理 化學性能，主要受乾性油種類，中和劑種類所影響。桐油／篦麻油者 顯示最高分子量及黏度，依次為大豆油及亞麻仁油者；二乙胺中和之 塗料具有最佳穩定性及低黏度；氨者則穩定性最差，含亞麻仁油變性 之結合劑、氨中和劑及乙二醇單丁醚(EGMBE)共溶劑之配方，塗膜乾 燥速度最快。 2.DSC試驗知，水溶性塗料系統，在溶劑揮發階段，呈現吸熱峰，壓住 自動氧化聚合之放熱反應，溫度升高至109℃溶劑完全揮發後，則顯 示平緩的放熱現象，係高溫下胺基樹脂與醇酸樹脂之架橋反應。又知 塗膜乾燥速度與醇酸樹脂之碘價呈正相關，與塗料動力學之前指數 常數的自然對數(lnZ)及活化能(Ea)則具負相關性，此三項性質與塗 膜乾燥速度之關係，非常顯著。 3.氨中和者之塗料，在塗膜硬度、耐水性表現最好，二乙胺中和者耐劣 化溫度最高；亞麻仁油變性之樹脂塗料，其塗膜硬度最高，桐油/篦 麻油者附著性最好，大豆油者在耐水性及耐熱性均佳。三種中和劑與 三種氣乾型水溶性醇酸樹脂所調配塗料，其塗膜可撓性均佳。 4.木質塗裝材經240小時人工促進耐候處理，塗膜外觀尚保持良好，但 由SRS-FTIR光譜分析，顯示樹脂之化學組成已發生光降解反應，其胺 基樹脂之甲氧基(915cm-1)及烴基(1376cm-1)吸收峰，顯示消失，268 小時暴露後三氮雜環(1556cm-1)吸收峰亦消失，且羰基(1710cm-1， 1721cm-1)明顯增加。 5.醇酸樹脂含5%丙烯醚化合物(TMPDAE)之塗料系統，顯著縮短塗膜氣乾 時間，但10%及15%者則沒有改善效果。又知，塗膜於相對濕度65%， 在不同溫度下之乾燥時，顯示乾燥速率隨溫度升高，逐漸增快，而溫 濕度之作用具有相加相乘之增效效益。當溫度為50℃，相對濕度為 45%，塗膜乾燥時間約2小時，附加照射紫外光者則於１小時氣乾硬 化，它較乾燥條件在25℃，65%RH者快9-18倍。封面 目錄 表目錄 圖目錄 摘 要 SUMMARY 一、緒言 二、文獻回顧 (一)水溶性樹脂之開發與沿革 (二)水溶性三聚氰胺樹脂架橋劑之性質 (三)水溶性醇酸樹脂之性質 (四)氣乾型水溶性胺基醇酸樹脂之硬化反應性質 (五)胺基醇酸樹脂之架橋反應模式 (六)中和劑對水溶性樹脂塗料之影響 (七)添加對氣乾型水溶性胺基醇酸樹脂之影響 (八)塗膜硬化與塗裝性能之評估 三、氣乾型水溶性醇酸樹脂之合成與所調配塗料之性質 (一)試驗材料與方法 試驗材料與方法 1. 材料 【1】樹脂合成與塗料調配 【2】水溶油變性醇酸樹脂之合成 【2】商業用高亞胺型甲基化三聚氰按樹脂 【3】塗料調配 (2)塗料塗佈用玻璃基材 (3)KRS-5 晶片 2.方法 (1)酸價 (2)羥價 (3)碘價 (4)色數 (5)分子量與分子量分佈 (6)樹脂黏度及流變性質 (7)表面張力 (8)塗料穩定性 (9)乾燥時間 (10)紅外線光譜 (11)硬化動力學分析 (二)結果與討論 四、氣乾型水溶性胺基醇酸樹脂塗料塗膜性質 (一)試驗材料與方法 1材料 (1)木質基材 (2)塗料塗佈用玻璃基材 (3)塗料 2.方法 【1】 試片之塗裝 (2)塗膜性質測定 【1】塗膜硬度 【2】 塗膜附著力 (A)方格試驗 (B)剝離強度試驗 【3】塗膜抗化學性質 (A)塗膜耐水性 (B)塗膜耐鹼性 (C)塗膜耐酸性 【4】塗膜熱劣化性 【5】塗膜冷熱循環試驗 【6】人工促進耐候試驗 (二)結果與討論 五、塗料氣乾性質之改良 (一)試驗材料與方法 1.材料 (1)樹脂合成與塗料調配 【1】水溶性醇酸樹脂之合成 【2】商業用高亞胺型甲基化三聚氰胺樹脂 【3】塗料調配 (2)塗料塗佈用玻璃基材 (3)KRS-5晶片 (4)紫外光起始劑 (5)DSC分析鋁盤 2.方法 (1)硬化乾燥時間測定 (2)紫外光照射對塗膜乾燥時間之影響 (3)硬化 動力學分析 (4)紅外線光譜 (二)結果與討論 六、結論 七、參考文