The study investigated algorithms for processing the gamma spectrum of PVT detectors. Various commonly used algorithms and algorithms were examined for handling the gamma spectrum of PVT detectors. During the research, the Energy Weighted Counts (EWC) algorithm was selected and implemented to process the gamma spectrum using simulated data of gamma scattering spectra on PVT detectors. Specifically, the energy-weighted algorithm was applied to effectively differentiate between the gamma spectra of three important isotopes Cs137, Co60, and I131. The results of the study demonstrated the success in meeting the specified requirements, especially in selecting the optimal algorithm for identifying the three isotopes on the PVT detector, all achieved through the utilization of the GEANT4 simulation software. This research not only provided a detailed insight into gamma spectrum processing but also proposed an effective algorithm using simulation software to explore and evaluate algorithms on PVT detectors. This marked a significant step in the research and development within this field.

Diatomite from Tuy An district, Phu Yen province, with different purities and diatom integrity as catalyst carriers, were adopted to prepare TNTs/g-C3N4 composite catalysts by a sol-gel method, with an optimal weight ratio of 1:1 for TNTs/g-C3N4 and diatomite. Compared with pure TNTs, g-C3N4, and TNTs/g-C3N4, the obtained composite photocatalysts exhibited lower photocatalytic performance under the same conditions and NO removal within 30 min under visible light. The NO gas treatment efficiency under the same conditions with different catalyst supports only decreases by approximately 18% at a reaction rate of 0.0950 min-1. This research on composite photocatalysts is a promising step towards practical environmental remediation. The use of diatomite as a carrier for photocatalytic materials is particularly noteworthy, as it is a naturally available and cost-effective source of materials. However, further improvements in the photocatalytic performance of the composite material are necessary to fully realize its potential in environmental remediation, including removing NOx and other pollutants. Overall, this study provides valuable insights into the influence of carriers on the photocatalytic activity of composite photocatalysts and lays the foundation for future research in this field.

Abstract: Urban agriculture is a highly concerned issue during the period of rapid urbanization in Vietnam. Research aims to propose a cultivation process for cultivating oyster mushrooms, utilizing coffee grounds from coffee businesses as a resource. This approach promotes circular economy principles, generating economic benefits for households while protecting the environment and being suitable for urban areas. The study conducted experiments on grey oyster mushrooms using different mixtures of coffee grounds and rubber wood sawdust at the following ratios: 0%, 25%, 50%, 75%, and 100% coffee grounds/rubber wood sawdust, filled into bags with a weight of 1.2kg. The research results showed that disease infection rates were mild in the 0% and 25% mixture ratios, while the remaining ratios exhibited moderate to severe infection levels. The highest mushroom yield was observed in the mixture ratio of 25% coffee grounds, with an average number of mushroom ears per bag reaching 29.7grams/bag, the dry weight is 63.8 grams/bag, with an average size ranging from 3 to 14 cm and a moisture content of 79.5%. The fastest colonization speed on the substrate is achieved by 25%, 50% coffee grounds blend, which fully colonizes the bag in a period of 25 to 35 days, the shortest time compared to the 75% and 100% coffee grounds blends, which take 40 to 45 days. The experimental results show that the 25% coffee grounds: 75% rubber sawdust blend is suitable for urban mushroom cultivation models and can be expanded on a large-scale farm, contributing to minimizing environmental pollution, utilizing limited urban land area, and providing high economic efficiency.

In the current work, we study a Cauchy problem for a time-fractional pseudo-parabolic equation with a globally Lipschitz source term. We prove the unique existence of a mild solution to the problem, by the common Banach fixed point theorem. This solution is then verified that exists globally in time by Gr¨onwall’s inequality. Compare to previous works about the similar issuse, we approach in a way that does not require using weighted spaces. Although our approach share a similar spirit to previous studies, our method seems to be more precise and natural.

It is very common to stabilize the preset value (Wanted value) of analog signals such as temperature, pressure, weight, flow, speed in automatic control. However, these control objects often have some problems such as overshooting, taking a long time to bring the system to a steady value, and large errors. One of the most used systems to overcome these problems is the PID, which is a preset stabilizing system with a quick function that returns the system to the set value in a short time without overshooting. error is close to zero. However, determining the scale parameters Ki, integral Kp, and differential Kd for the system to work optimally is a problem that needs to be studied. This paper presents how to accurately determine differential, integral, and scale coefficients according to 3D virtual reality model. Used a lot in simulation modeling for training and practical applications.

The study is conducted to assess the level of noise pollution from traffic activities in urban areas (in the case of Thuan An city, Binh Duong province) with the specific goal of applying geographic information systems. (GIS) in building noise pollution distribution maps in the study area. The research team collected noise data at peak hours and normal hours on weekdays and weekends using noise meters at 61 survey points. Noise measurement data was then interpolated using IDW (Inverse Distance Weighting) method to assess the spatial distribution of noise in Thuan An city. In addition, the study digitizes traffic routes and special areas (hospitals, schools, churches - pagodas) in the study area to identify areas affected by sound noisy. The results show that the areas near the main road are most affected by noise during rush hour, while areas in the small lane are noise level within the permitted range. In addition, the results also show the difference in noise level and noise time between weekdays and weekends

Coffee is among the favorite drinks in Vietnam and many other countries. Production and consumption of coffee have released a huge amount of spent coffee ground. This study aimed to determine phenolic acids and fatty acids of spent coffee grounds collected in Ho Chi Minh city and how phenolic acid profile was affected by different environmentally friendly extractants. The results showed that average level of chlorogenic acid in ethanol/water extracts (840.4 779.9 ug/g) was significantly higher compared to water extracts (300.0 ug/g). Furthermore, the average total level of phenolic acids in ethanol/water extracts (1215.3 ug/g dry weight) was greater than that in the water extracts (779.9 ug/g dry weight). This indicated that ethanol/water outperformed water in regard to extraction of phenolic acids in the spent coffee grounds. Oil extracted from the spent coffee grounds was rich in linoleic acid (61 ug/g) and palmitic acid (47 ug/g). The findings of our study showed that the spent coffee grounds originating in Vietnam are a good source of phenolic acids and polyunsaturated fatty acids that could be utilized for food and nutraceutical production.

This study was conducted on a group of male and female students of age range of 6-11 years at an elementary school. In this paper it is tried to analyze the effects of nutrition and sports on height and weight of male and female students. The result showed that these factors have an impact on students’ height and weight, and there were the difference between groups doing sports regularly and rarely, also among groups of different nutrition.