This research aims to study the relationship between tax planning & performance and the stock prices & dividend payments of companies listed on the Stock Exchange of Thailand SET100 group. It was conducted by collecting information from financial statements annual reports and the information registration forms (Form 56-1) of 69 companies from 2015 to 2019. Descriptive statistics and inferential statistics were used for data analysis including correlation analysis and multiple regression analysis. The study results show that the return on equity ratio (ROE) book value per share (BV) and earnings per share (EPS) ratio positively correlated with the stock prices. The corporate income tax rate to total assets (TAX/ASSETS) the return on total assets (ROA) the return on equity (ROE) and the book value per share (BV) ratio were positively correlated with the dividend yield (DY) ratio. The earnings per share (EPS) ratio had a negative correlation with the dividend yield (DY) ratio and the effective corporate income tax (ETR) ratio had a positive correlation with the dividend payout ratio (DP) with a statistical significance at 0.01 and 0.05 levels.

Corrosion of steel reinforcements in concrete is one of the main causes of early deterioration and reduction of service loads of reinforced concrete (RC) structures. This paper reports the results of an experimental program that was carried out to evaluate the effect of reinforcement corrosion on the flexural performance of RC beams and to investigate the efficiency of externally bonded carbon fiber reinforced polymer (CFRP) sheets to repair the corrosion-damaged RC beams. Seven RC beams with the same cross section and reinforcement details were prepared including the control beam (B0). First tension reinforcements of six RC beams were corroded by using an accelerated impress-current process to obtain corrosion levels of 15% 30% and 50% of weight loss according to Faraday’s law. Then three beams were repaired using CFRP sheets attached to the bottom surface leaving the other three unrepaired. All beams were subjected to the four-point bending load test. The experimental results show that the corrosion specimens demonstrated a significant deterioration on the structural performance and the integrity by decreasing in their ultimate load capacity stiffness and ductility. The deterioration by corrosion of tension reinforcements can be successfully overcome using CFRP sheets as the repair material. The technique can restore the beam strength to its original design strength except specimen B50F2 having severe steel-corrosion damage of 50%. A conservative value of the ultimate bending capacity of the beams with low corrosions (15%-30%) can be predicted by using RC conventional models as suggested in ACI 318. However the opposite trend is obtained for the high corrosion beam (50%). Appling ACI 440.2R provision to predict the ultimate flexural capacity of corroded beams repaired with CFRP sheets shows rather fair values for low corrosions (15%-30%) but significantly overestimates the strength of the high corrosion beam (50%).

In this study the wind speed characteristic and evaluation of wind power generation at Samoeng district Chiang Mai were investigated using wind speed data and wind direction data during time of January 2011 to December 2011 and measured at a height of 20 40 and 80 m above ground level. It was found that the mean wind speed of 3.8 3.92 and 4.30 m/s. While the mean wind direction of 20.73% and indicating from the southwest. The mean of power density of 107 W/m2 the shape parameter (k) was 1.715 1.633 and 1.783 scale parameter (c) of 3.649 3.651 and 4.092 m/s the mean of wind shear coefficient was 0.19. The evaluation of wind energy for electricity generation by install the wind turbine of Nordex N50 from Germany and Vestas V90 from Denmark were capacity of 800 kW and 3 MW. It could produce annual electricity of 1761379 kWh and 3772400 kWh and the capacity factor show 25.13% and 14.35% respectively. Finally the results showed the northern area of Thailand was suitable for wind power development in further.

This research was aimed to study of the effect of dragging force on paper cone falling by using the high-speed video analysis technique. Four different sizes of paper cones ranged from 3.00-5.70 centimeter were used. The cones having the same mass of 12 g and falling from 2.50 meters height were recorded for 240 frames per second and then were analyzed using the Tracker Video Analysis software. The results showed that (1) all four different sizes of paper cones were not freely fall with the Earths gravity due to indirect proportion with time of theirs speeds. The terminal speed of two large cones having diameter of 5.00 and 5.70 centimeters were 4.42±0.03 and 3.97±0.04 meters per second respectively. Only 0.87% of these experimental values were different from the theoretical ones. (2) The theoretical trajectory of these cones falling using the terminal speed from the experimental agrees with the theoretical ones. (3) The experimental drag force showed a second order function of the paper cone’s speed. The evaluated drag force during terminal area is approximately equal to the cone weight. Thus this technique can help students and teachers to visualize simple physics phenomena and relate them to the physics principles learnt in the classroom

Direct thermal decomposition mercury analysis is an efficient technique for determination of mercury in facial whitening creams. The analysis can be performed without any sample preparation. The samples can be weighed and placed directly into the analyzer. Thus there is no chemical waste produced in sample preparation. The time and energy used in sample digestion are saved as well. The calibration curve between mercury absorbance in terms of peak height and weight of standard mercury in the range of 0.1-10 ng was created. The calibration curve was linear followed the equation y=2.003x10-2X– 5.14x10-4 with coefficient of determination (R2) 0.9991. The precision in term of repeatability were 14% and 5.9% rsd (n=3) at 1.2 and 868 µg kg-1 respectively. The recoveries were between 88-110%. The detection limit (LOD) was 0.1 µg kg-1 (3sd/m n=10). The amount of mercury detected in 12 whitening cream samples sold in Chonburi province during the year 2019 were within the safety standard permitted in general cosmetics under the notification of the Ministry of Public except two samples were over the permitted standard.