This work aimed to study the improvement of mechanical properties and cost reduction of biodegradable packaging made from polylactic acid (PLA) by using sisal fiber. Because sisal fiber as natural fiber is good mechanical properties biodegradable material and low cost. The variables studied were the addition of sisal fiber surface treatment with epoxy silane and fiber direction. Their effects were investigated by tensile flexural and impact testings and morphology analysis. The results suggested that the addition of sisal fiber increased Young’s modulus Flexural modulus and ultimate tensile stress whereas elongation at break and impact strength tended to decrease. For the effect of surface treatment it was found that tensile and flexural moduli increased with epoxy silane treatment but tensile flexural and impact strengths slightly changed. Surface treatment by epoxy silane led to good interfacial bonding by hydrogen bonding between oxirane ring of epoxy silane and hydroxyl group of PLA. The effect of fiber direction revealed that tensile properties of composite in fiber direction of 0o were higher than those of composite in fiber direction of 45o. Fiber direction did not affect flexural and impact properties.

Oil spills in every household caused by cooking are difficult to eliminate when accumulating for a long time. In this study the researchers aimed to develop the remaining coffee grounds for oil absorption. From 2 coffee ground samples types A and B obtained from different coffee shop & coffee grounds type A demonstrated more effective in absorbing vegetable oil. The sample A was thus treated with hydrogen peroxide (H2O2) solution at the concentration of 0.5 1 3 33 50 80 and 100 percentages for 30 minutes and determined for the efficiency in oil elimination. The sample with at least 80 % (v/v) H2O2 showed the most effectiveness in absorbing oil. The coffee grounds that were later treated with pineapple juice fermented Kefir could help increase coffee ground degradation at 51.07 percentages. The Kefir treated coffee grounds packed in an absorbent bag revealed higher effectiveness in oil absorption at least 51.07 percentages compared to the controls that were cotton bag and coffee a harboring at the percentages of 73.85 and 30.04 respectively. This coffee ground bag after thrown into the ground could be decomposed in nature for 52 percentages within 1 month. Due to the oil elimination properties of the coffee grounds that are environmentally and human friendly as well as low cost it is possible to develop the kefir treated coffee grounds for being oil-absorbing products that can come in contact with human skin.

The objective of this research is to construct a phased array device to be able to inspect all sizes of welded pipes and to study materials suitable for creating a phased array. The results obtained from testing both materials are PLA plastics carbon fiber. In order to obtain the force exerted on the material and the intensity of the force exerted on the same material it is found that the strength of the comparison between the two materials is different from the PLA plastic test. Of carbon fibers will be strong and lighter than plastic. Result from the test for Elastic In the impact and strength tests of both materials it can be used to examine pipes with a circumference of 50 centimeters to 100 centimeters and to use a 34 mm. length phased array probe with a width of 24.6 mm. 36 degrees angle and then adjust the strap as needed to reduce the steps during the use of inspection equipment.

Nowadays Thailand is realizing the economic value of earthworms. Earthworm farming is a driving force that can stimulate the Thai economy. The objective of this project is to measure the humidity and temperature properties of the worms the two boards are circuit boards in microcontroller. These are the WeMos D1 ESP8266 board and NodeMCU ESP-32S board. The WeMos D1 ESP8266 board to measure the amount of water and temperature of of the soil and can turn the water supply on or off automatically. The NodeMCU ESP-32S board has a database system to collect real-time humidity and temperature data. The data is processed and displayed via a web interface. The experiment showed that in regard to earthworm farming the soil moisture alert system in the earthworm closet has a temperature accuracy of 28.5°C. The top soil has a humidity accuracy of 65% the middle soil has a humidity accuracy of 67% and the lower soil has a humidity accuracy of 67%. This allows the ideal moisture and humidity levels for the propagation of earthworms to be maintained. The alert system displays the temperature and humidity in the earthworm closet and can turn the water supply off if the soil moisture level gets too high for the worms - this can all be monitored via the web application. .

This research aimed to study the relationship between financial ratios of operating efficiency and profitability of listed companies on the Stock Exchange of Thailand. Data was collected from the financial statements of the real estate and construction groups from 2015 to 2019. The data were analyzed using descriptive statistics such as frequency percentage mean and standard deviation. The inferential statistics were Pearsons Correlation Coefficient and Multiple Regression Analysis. The results of the study found that 1. operating cash flow activities positively correlated with the return on asset 2. the debt to asset ratio was negatively correlated with the gross profit margin net profit margin return on asset and return on equity 3. average collection period was negatively correlated with the gross profit margin and net profit margin 4. inventory turnover had a negative correlation with the return on asset 5. the total asset turnover was positively correlated with the net profit margin return on asset and return on equity with the statistical significance at a level of 0.05.