NKRAFA JOURNAL OF SCIENCE AND TECHNOLOGY

The Interpolation Theorems for the Star Arboricity

Teerasak Khoployklang — Thu, 02 Jan 2025 00:00:00 +0700

The purpose of this research is to prove that the star arboricity is an interpolation graph parameter on the class of simple and connected graphs with m edges and n vertices. The result of this research shows that the star arboricity is an interpolation graph parameter on the class of simple and connected graphs with m edges and n vertices denoted by and , respectively. As a result, for and , there exists a graph with for all . In the same way, for and there exists a graph with for all

Calculation the Equation of Spring Collapse Distance as a Function of Time via External Force Squared Sine Function in Simple Harmonic Motion

Artit Hutem, Jetsadaporn Pakamwang, Kan Khoomsab — Fri, 17 Jan 2025 00:00:00 +0700

This research aims to calculate the equation of spring collapse distance as a function of time. In a system of objects, mass moves with an external force against the end of a spring attached to mass . In this research, Newton's second law of motion is used to write the equations of motion of this system. We use the mathematics of nonhomogeneous second-order differential equations to calculate the equation of displacement of the spring as a function of time and to calculate the equation of displacement between mass and mass when the two objects collide at the intermediate spring. The result of the calculation of the spring compression distance will have a decrease in the number of ripples when the spring constant increases.

Marketing Mix Factors Affecting Satisfaction in Using Freight Transport Services in Nong Chok District, Bangkok

Chidchanok Inthong — Fri, 17 Jan 2025 00:00:00 +0700

This research aimed to study the marketing mix factors affecting the satisfaction of freight transport service users in Nong Chok District, Bangkok. The sample group consisted of 400 freight transport service users in Nong Chok District. The main research instrument was a questionnaire related to the 7Ps marketing mix: Product, Price, Place, Promotion, People, Process, and Physical. Data were analyzed using t-test, One-way ANOVA, and Multiple Regression Analysis. The results of the research found that the 4Ps: Place, Promotion, People, and Process had a statistical significance on the customer satisfaction of service users at the 0.05 level and could predict customer satisfaction by 73.9% ( = 0.739).

Printing Cotton Fabric with Buffalo Dung

Narat Pornitibun, Piyaphong Yongphet, Pannraphat Takolpuckdee — Sun, 02 Mar 2025 00:00:00 +0700

This research aimed to study the natural dye extraction process from buffalo dung, investigate mordants for enhancing dye fixation, and analyze the quality of the natural dye derived from buffalo dung, with the goal of developing a commercial prototype. In order to prepare the material for further processing with pre-mixed printing paste, the synthesis method for creating dye from buffalo dung was divided into 11 parts. These procedures included extraction at 90°C for 45 minutes, drying at 150°C for 60 minutes, and grinding into a fine powder. With a Hunter Lab apparatus, CIE (L*a*b*) color measurements were used to assess the use of mordants, particularly alum and ferrous sulfate. The results showed no statistically significant difference at a confidence level of 0.05. The dye's quality was evaluated using ISO 105-C10 Test A 2006 guidelines, and it showed washing fastness levels ranging from 4 to 5, which were classified as good to very good. Abrasion resistance testing under ISO 150-X12 2016 standards revealed that the dye performed better under dry conditions. The findings highlighted the potential of buffalo dung-derived dye in product development for income generation and as a pathway toward product standard certification.

Development of Microfluidic Paper-Based Analytical Devices for Simultaneous Colorimetric Ammonium and Nitrate Detection

Sun, 02 Mar 2025 00:00:00 +0700

The frequency of terrorist attacks involving Improvised Explosive Devices (IEDs) is expected to continue increasing. Ammonium nitrate fuel oil (ANFO) is the preferred main charge in IEDs due to its low cost and wide availability. Hence, there is a pressing need to develop an ammonium nitrate detection method that is easy to use, cost-efficient, fast, and reliable. This research developed the µPADs as viable devices for detecting ammonium nitrate in the field alongside a mobile phone camera. In this study, a two-lane µPAD was developed to detect both ammonium and nitrate ions in an ammonium nitrate solution. The purpose of this research was to develop a simple and low-cost colorimetric method for simultaneous ammonium and nitrate ion detection using microfluidic paper-based analytical devices (µPADs) fabricated by the wax-screen printing technique. The two-channel µPADs were designed and fabricated. The first channel was used for ammonium detection using Nessler’s reagent coated on the detection at the end of the channel. The second channel was used for nitrate detection using a Griess reagent. By simply dropping the sample at the center of µPADs, the developed µPADs were able to detect both ammonium and nitrate in a short time (only 4 minutes). The colored product on the µPAD (yellowish-brown and pink color for ammonium and nitrate, respectively) was then captured with a camera on a smartphone under a commercial controlled light box and its color intensity was obtained by using ImageJ software. Using the NH4NO3 concentration in the range of 100 – 800 ppm, under optimum conditions, there was a good linear relationship (r2 = 0.9961 for ammonium concentration range of 200-800 ppm and r2 = 0.9894 for nitrate concentration range of 100-800 ppm) and the detection limit was 48.760 and 81.966 ppm for ammonium and nitrate, respectively.

Innovation Weed Management using Alternating Current

Anucha Rikakorn, Yodphatarachai Kanitpunyacharoen, Thanit Metheenukul — Sun, 02 Mar 2025 00:00:00 +0700

The development of a weed control innovation using alternating current aims to create a chemical-free weed control prototype and evaluate its efficiency through research and development methods on giant mimosa weeds with stem diameters ranging from 12 to 35 millimeters subjected to alternating current at a maximum voltage of 2,500 volts for electric discharge durations of 5, 10, and 15 seconds. The results demonstrated that the weeds withered and ultimately died within an average of 2.25, 3.75, and 5.75 days, respectively, corresponding to an increase in average electric power from 95.45 to 203.14 watts, relative to stem diameter.

Designing a Smart Classroom System for Teaching and Learning to Improve Potential of Air Cadets

Sirunya Thanompolkrang, Tananop Limsuwanroj, Supavadee Leelayut — Wed, 26 Mar 2025 00:00:00 +0700

This research aimed to investigate the opinions of lecturers and air cadets regarding the teaching and learning model of the smart classroom system. The collected data were analyzed and used to design a smart classroom system for teaching and learning to enhance the potential of air cadets. The sample group consisted of 69 lecturers and 112 air cadets.

The study found that a tiered classroom layout is suitable for large classrooms, while group seating arrangements are more appropriate for smaller classrooms. However, in the field of Social Sciences, it was found that classroom layout had no impact on learning in small classrooms, whereas in Mathematics, the layout was perceived to have no effect on learning in large classrooms. Regarding classroom structure, multiple interconnected classrooms were found to be suitable for large classes, while independent classroom setups were more appropriate for small classes. Nonetheless, Mathematics lecturers believed that classroom structure did not affect learning performance, regardless of classroom size. Most lecturers and air cadets agreed that a blended learning approach was preferable. However, air cadets in the Social Sciences placed more importance on learner-centered teaching methods. In terms of essential skills, both instructors and air cadets considered digital technology proficiency to be the most important. In contrast, for the Humanities, communication skills were deemed more critical than technological skills. As for hardware, the most essential components identified were a reliable internet network and wireless microphones. In terms of software, both lecturers and air cadets agreed on the need for subject-specific programs and interactive learning software. Additionally, there was a strong demand for systems integrated with cloud services, especially in the Humanities and Social Sciences.

Weather Alert System for Air Cadet Training Using IoT

Chalermkwan Siripanth, Sirawich Tantra, Poomipat Jobkonsuek — Fri, 28 Mar 2025 00:00:00 +0700

A survey conducted during the academic years 2018–2021 found that 13 cadets from the Royal Thai Air Force Academy suffered from severe heat-related illnesses. As a result, the supervisor of the Commander Ready course for the academic year 2022 prioritized addressing heat-related injuries among cadets, implementing a policy that stated: “There must be no heat-related injuries during the training of pre-cadet students transitioning into air cadets.” To address this issue, the research team recognized the need to develop a device capable of measuring temperature, relative humidity, heat index, and dust concentration. The device should display real-time data via the internet and provide alerts and recommendations to those responsible for training, based on criteria from the U.S. Army Public Health Command (USAPHC) and the Thai Society of Toxicology. The proposed support device was developed using an ESP32 controller, a DHT22 sensor for temperature and humidity, a PMS5003 sensor for dust concentration, an online display system that operates without a central server, and a notification system through Line Notify. Testing by 22 training supervisors and instructors showed a satisfaction rate of 86% for the prototype device.

Development of an Information Technology Competency Evaluation System for Air Cadet

Chanyawat Sathidbhattarasombad, Chawaphong Khunsoongnoen, Tewa Kanjanachom — Tue, 01 Apr 2025 00:00:00 +0700

This research aimed to develop an IT competency assessment system for fifth-year class Air Cadets, implemented as a web application using ASP.NET technology and Microsoft Access database. The system consisted of two main components: the administrator module and the student module. The development followed the Waterfall Model approach. After development, the system was tested over a period of 8 years, from 2017 to 2024. The system was then evaluated in two parts: First, by IT experts, who rated it with an average score of 3.75 and a standard deviation of 0.57. Second, by 765 users, chosen through a purposive sampling method, who rated it with an average score of 3.60 and a standard deviation of 0.46. These results indicated that the system’s performance was considered to be at a good level.

Measuring of Volatile Compound from Roasting of Coffee Beans Using Portable Air Quality Device

Palathip Kakanopas, Napassanan Khiawkhwao — Tue, 08 Apr 2025 00:00:00 +0700

The coffee beverage industry has proliferated across Thailand, leading to intense competition. To attract customers, businesses have invested in aesthetically pleasing spaces, amenities, and affordable prices. However, another crucial factor is the roasting of coffee beans to achieve the right aroma, which directly influences the taste. Various methods have been developed for roasting coffee beans to obtain a harmonious flavor profile. Gas chromatography is a popular technique for analyzing the volatile organic compounds produced during roasting, but it requires specialized expertise and is costly, making it unsuitable for small-scale businesses. This research aimed to develop a technique for measuring volatile compounds from roasted coffee beans (Arabica, Robusta and Civet coffee) using portable air quality device. This would enable small-scale businesses to develop and assess the quality of their coffee beans as needed. A comparison of quantitative analysis results between the portable air quality monitor and gas chromatography revealed a correlation coefficient (R²) of 0.9792.