จำนวน Repository ( 278 )

Factors influencing to the inappropriate behaviors for scuba diving in coral reef
Factors influencing to the inappropriate behaviors for scuba diving in coral reef

The study of factors influencing to the inappropriate behaviors of SCUBA divers in coral reef areas was done. The study performed by Quota sampling technique which the data was collected from 279 divers. The frequency of inappropriate behaviors of divers was recorded for in 10 minutes each. The results show that the average contacts damage and interference to aquatic organisms made by individual divers were 2.20 0.22 0.02 ? 0.01 and 1.70 0.20 respectively. No significant difference of factors of contact and damage made by divers but there was significant difference between nationality (t = 5.24; df = 277; p < 0.001) and pointer possession (t = 2.59; df = 277; p < 0.01) with the number of times divers made interference the aquatic organisms. This study results can be used to propose the guidelines and management strategies for conservative and sustainable of SCUBA diving in the coral reef.

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Comparison alpha and gamma spectrometry method for the determination of pb-210 in freshwater sediment
Comparison alpha and gamma spectrometry method for the determination of pb-210 in freshwater sediment

The comparison of methodology from and -spectrometry methods has been made for freshwater sediment. The differences of precisions 18% and 15% were found for ? and -ray spectrometry respectively. Results from the analysis of certified reference materials (IAEA-326 327) showed good agreement with recommended values and data available in the literature. Thus an alternative methodology based on alpha/gamma activity ratio was developed and tested using different samples. The method is based on the determination of total -activity (46.53 keV peak associate with Pb-210) and the total -activity present in the aliquot. Differences between methods could be caused by different behaviors of Pb-210 and Po-210 (used for alpha measurement) in the freshwater sediment. In gamma spectrometry errors may arise when many gamma emitters are measured simultaneously and their activity peaks overlap. In alpha spectrometry chemical separation of Po-210 may result in analytical error due to incomplete sample dissolution. Pb-210 activities derived by alpha and gamma methods are shown to agree within counting error. The inherent compatibility of analytical results based on alpha or gamma techniques is established. Nevertheless the choice of an alternate method to determine the freshwater sediment criteria to time comfortable convenient and budget.

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Thai dessert product development form palmyra - plum powder
Thai dessert product development form palmyra - plum powder

A research was aimed to investigate appropriate procedures of cabinet drying of flour made from Toddy palm at 60 65 and 70 degree Celsius and employed it as an ingredient in 3 Thai traditional desserts - Kanom-Chun Kanom Num-dok-mai and Kanom Puy-fai respectively. The investigation emphasized on these effects on color and odor of the products. Palm flours at the level of 0% 10% 20% and 30% was added then physical and chemical properties consumer’s acceptance were investigated and their shelf-life of the products packed in polyvinyl chloride and double layer of polyvinyl chloride and polyethylene at room temperature was inspected every day. Drying temperature of 60 ?C and 10% flour addition in the formulation found to be the optimal condition and also produces best quality of the products accepted by consumers as in such conditions overall score of acceptance was statistically significantly highest ( P>0.05) with 7.73 7.95 and 7.62 average scores for Chun Kanom Num-dok-mai and Kanom Puy-fai consecutively. Proximate analysis of these products in terms of moisture ash fat fiber protein and carbohydrate revealed that they were statistically different ( P>0.05). When 100 consumers were asked to taste and rank their acceptances Kanom Puy-fai Kanom Num-dok-mai and Kanom Puy-fai was acceptable by 66 28 and 6 panels successively. However these products should not store for more than a day due to the fact that microbiologically total viable count would be exceeds specified standard by a day.

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Solar powered aerator for public reservior
Solar powered aerator for public reservior

This paper presents a prototype of solar powered aerator for public reservoir which consist of three main parts first aerator-venturi type second electrical system from solar panels and third floating structures. The proposed aerator has been adopted from an used electric water pump to have a water inlet an air inlet and mixture air and water outlet releasing bubbles through under water. Electrical system acting as the core energy resource receives light of solar energy via 2x120 watts solar panels and then accumulating the obtained electric energy to battery. The 24-volt battery will supply power to 150 watt directed current motor for driving the venturi aerator. To archive evaluation the combined aerator with solar system has been installed at Nong Luang reservoir in Muang Tak province and has operated for 30 minutes. To collect water samples have been done twice times at before and after operation. The obtained laboratory results show that dissolved oxygen (DO) increased from 0.87 mg/l to 3.56 mg/l and the biological oxygen demand (BOD) decreasee from 9.7 mg/l to 7.2 mg/l. According to the results it confirms that the proposed solar powered aerator for public reservoir can operate efficiently and independently.

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Sensitivity analysis in efficiency of the solar water heater system self-circulated by a steam power
Sensitivity analysis in efficiency of the solar water heater system self-circulated by a steam power

The sensitivity analysis in efficiency of solar water heater system self-circulated by a stream power was performed in this study. The mathematical model of the system was developed based on the experimental results to predict the available amount of water pumped temperature and pressure in main devices. This system was operated by using a simple flat plate solar collector with an exposed area of 1.58 m2 and a storage tank of 30 liters. The results of systematic performance which performed by math model was compared to the experimental results. It was found that the values of were 5.876% 3.583% and 1.361% for vapor pressure and temperature in the flat plate solar collector and temperature in the storage tank respectively. The system was workable when the solar energy input values were equal to or greater than 584 W/m2 607 W/m2 632 W/m2 and 662 W/m2 for discharge head 1 m 1.5 m 2 m and 2.5 m respectively. From system simulation the system could have the daily average thermal efficiency was between 2.94 – 11.47% and the daily average pump efficiency 0.00057 – 0.0026% depending on the intensity of incident solar radiation and the discharge head of the system.

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