Research Journal Phranakhon Rajabhat : Science and Technology

MEASURING THERMAL CONDUCTIVITY OF MATERIALS BASED ON THERMOELECTRIC EFFECT

2023-06-28T14:07:29+07:00

This work aims to develop an apparatus for measuring the thermal conductivity of bulk materials based on the steady-state method, employing a thermoelectric module (TEM). The cost-effective and easily accessible TEMs were utilized as the heating source, cooling source, and heat flux meter. The TEM was used to generate heating and cooling on the basis of the Peltier effect, which involves the conversion of electricity into thermal energy. On the contrary, the Seebeck effect, based on the direct conversion of thermal energy into electricity, was employed as the principle for creating a heat flux meter. To generate heating or cooling, four TEMs, each with dimensions of 4.0 × 4.0 cm², were connected in a parallel circuit to form the heating and cooling sets. Each set was in direct contact with a copper heat exchanger plate, creating a sandwich model with an 8.0 × 8.0 cm² sample material placed in the middle. A TEM was embedded in the copper plate near the heating set to measure the heat passing through the sample surface. To validate the accuracy of this apparatus, the thermal conductivity value of a polystyrene foam, which was tested according to ASTM C518, was compared with the value obtained by using an apparatus developed in this work. The results indicated that this apparatus achieved high accuracy, with an average error of 0.87%.

DEVELOPMENT OF ODOR ABSORBED CHARCOAL LUMP PRODUCT FROM NIPA PALM FRUIT

2023-03-20T09:31:31+07:00

This research aimed to produce charcoal lumps from nipa palm fruit wastes for use within households and developed into odor absorbed products. The whole and half cut-nipa palm fruits were burned in an artificial charcoal kiln. The weight of nipa palm fruit charcoal after burning was lost by 50-60%, glossy surface, and perfect shape. Then, these charcoal lumps were investigated the chemical properties and heat values. It was found that the heat value of charcoal lumps was 5,883 calories/gram, fixed carbon content was 60.40%, and ash content was 18.37%. After that, the nipa palm fruit charcoal lumps were developed into 2 types of odor absorbed charcoal products. The whole-nipa palm fruit charcoal lumps were packed in the net bag as an odor absorbed charcoal bag. The half-cut nipa palm fruit charcoal lumps were ground and molded to an odor absorbed charcoal briquette by using tapioca starch as a binding agent. Both odor absorbed charcoal products were estimated for satisfaction by 30 volunteers. The results showed that the volunteers were satisfied with the appearance of both products at the highest level but satisfied with the durability of both products was the lowest level because easily broke out of charcoal products. This research shows that the nipa palm fruit wastes have the potential to be produced into charcoal lumps for use as fuel within households and as odor absorbed products.

LOWER BACK AND HIP MUSCLES STRENGTH AND KNEE PAIN IN RECREATIONAL RUNNERS

2023-07-20T09:43:43+07:00

Knee pain is the most common problem in runners. The core muscular strength is a related factor. This research aimed to compare the strength of lower back muscles, hip muscles in the group of recreational runners with and without knee pain. The research was conducted on the basis of retrospective descriptive study. The research participants included 44 runners aged 18-35 years, divided into 22 runners without knee pain and 22 runners with knee pain. Maximum isometric voluntary contraction of back extensor, trunk lateral flexor, hip extensor and hip abductor, classified into dominant side and non-dominant side were measured using a hand-held dynamometer for three times. The value of the maximum contraction was recorded. The mean, standard deviation, and data comparison were determined using the Independent T-test, with statistical significance set at 0.05 level. The study results indicated that the mean maximum isometric voluntary contraction of trunk lateral flexor, both dominant side and non-dominant side were statistically significantly different between groups, while the strength of back extensor, hip extensor, and hip abductor were not statistically significantly different between groups. The study results showed that the strength of trunk lateral flexor muscles seem to be another factor of knee pain in recreational runners. The information can be used in an exercise program for preventing or restoring knee pain in recreational runners accordingly.

DRYING MEDICAL PLANTS IN CHAI BADAN, LOPBURI BY SOLAR DRYER FOR PRODUCING THAI HERB PRODUCTS

2023-09-13T14:26:10+07:00

In this study, white fingerroot, turmeric, and green chiretta were dried using a solar dryer, reducing their moisture contents to 9.72, 10.14, and 9.83% on the wet basis (wb), respectively. The HPLC technique was used to examine the active components. The flavonoids, which include Pinostrobin 66.57 mg/g and Panduratin A 3.04 mg/g, are the active component of dried white fingerroot. Fresh and dried turmeric were found to have 6.78 mg/g and 48.23 mg/g of curcumin, respectively. The dried green chiretta leaf and stem powder contained 34.94 mg/g of andrographolide. In addition, the Thai Community Product Standard of 480/2547 indicated that the total microorganism was fewer than 1×10³ colonies/gram. Finally, the powdered dry herb was placed into capsules for easy application.

THE RELATIONSHIP OF SMARTPHONE ADDICTION BEHAVIOR AND ATTENTION DEFICIT HYPERACTIVITY DISORDER (ADHD) IN THE GENERATION Y POPULATION

2023-08-17T11:04:08+07:00

This research aimed to investigate the correlation between smartphone addiction behaviour and attention deficit hyperactivity disorder (ADHD) among the Generation Y population, as well as explore the association between personal factors and smartphone use behaviour. The study employed a quantitative research design and conducted a survey among Generation Y individuals (born between 1980 and 2000) residing in Bangkok, with a sample size of 317 participants (smartphone users). Data was collected using a questionnaire, and statistical analysis included frequency, percentage, mean, standard deviation, and chi-squared test.

The findings showed a significant association between smartphone addiction behaviour and ADHD at a significance level of 0.05. Moreover, factors such as age or year of birth, status, income, duration of smartphone use, number of days of use, and smartphone activities exhibited a significant relationship with smartphone addiction at a significance level of 0.05. Conversely, gender, age or year of birth, status, monthly income, occupation, duration of use, and smartphone use activities showed a significant correlation with ADHD at a significance level of 0.05.

EFFECTS OF SUCRALOSE AND CARRAGEENAN ON THE QUALITY OF READ-TO-DRINK JELLY PRODUCTS FROM FRUIT AND GINGER

2023-09-06T10:21:43+07:00

The objective of this research was to investigate the impact of sucralose and carrageenan application on the quality of ready-to-drink jelly prepared from fruit and ginger. The results of the experiment found that the jelly formula ‘A’ presents the highest sensory liking scores across all evaluated attributes, including appearance, color, aroma, flavor, texture, and overall preference. Replacing 40% of the sucrose with sucralose in the jelly formulas resulted in the highest liking scores from the testers in all aspects. A study of the 4 levels of carrageenan found that sucralose replaced sucrose and the reduction of carrageenan did not affect color values. The water dissociation value tends to increase and the hardness tends to decrease. The formulation containing 1.25 g of carrageenan was observed to have the highest acceptance score except aroma value by the testers. Therefore, ready-to-drink jelly products made from fruits and ginger were analyzed for chemical composition and found that based on 100 g, carbohydrates, fat, protein, and fiber were 31.83 ± 1.64, 0.02 ± 0.01, 24.87 ± 0.07 and 2.62 ± 0.19 g, respectively, and 226.98 ± 2.3 kcal for energy. Consumer acceptance testing found that people preferred the moderate level. The result in terms of consumers interested in purchasing the product if it is available in the market has a good taste, appealing appearance, and is considered healthy were 77, 39, 37 and 34%, respectively.

COMPARISON OF EFFECT OF PARASITISM OF ANISOPTEROMALUS CALANDRAE (HOWARD) AND THEOCOLEX ELEGANS (WESTWOOD) TO MAIZE WEEVIL (SITOPHILUS ZAEMAIS MOTSCHULSKY)

2023-09-22T10:59:55+07:00

The aim of this study was to evaluate the impact of percentage parasitism, quantity of progeny, and sex ratio on the fourth larval instar of the maize weevil in Anisopteromalus calandrae (Howard), Theocolax elegans (Westwood), and A. calandrae + T. elegans. Complete randomization (CRD) was used in the arrangement of the studies. Five pairs of male and female A. calandrae, T. elegans, and A. calandrae + T. elegans (1:1) were released into glass vials containing maize seeds and the larvae of the maize weevil.The result showed that the parasitism, the number of progeny and sex ratio of A. calandrae were significantly higher (p<0.05) than those of T. elegans and A. calandrae + T. elegans. A. calandrae exhibited the highest parasitism at 74.38%, 42.60+2.82 and 1:1.81, followed by T. elegans with 58.62%, 27.60+2.20 and 1:1.39, in terms of parasitism, progeny, and sex ratio. Whereas the parasitism, progeny count, and sex ratio of A. calandrae + T. elegans were 32.24%, 18.20+1.46, and 1:1.22, respectively.

CALCULATE THE ENERGY FROM URANIUM-236

2023-09-13T14:43:43+07:00

This academic article provides all the principles necessary to understand the calculation of the energy in uranium-236 which are suitable for the general teachers and lecturers. The histories, Einstein’s mass energy, average binding energy, were explained. Owing to the strange nature of nuclear fission, one must understand the interpretations of nuclear fission before properly understanding the calculation of the energy from uranium-236. We can now estimate the energy from uranium-236, using the deviation between the average binding energies of the uranium-236 parent nuclide and the fission product nuclei, which suggests that the energy of uranium-236 is about 203 MeV.