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Purple passion fruit is widely cultivated in Vietnam and its peels are considered by-products or agricultural waste after processing, which could cause environmental issues. Notably, these peels contain some valuable components with high bioactivities and applicability, such as anthocyanins (natural colorants) and pectin. Therefore, this work proposes a process for the sequential recycling of anthocyanins and pectin from purple passion fruit waste, in which anthocyanin extraction conditions and their bioactivity by ultrasound-assisted solvent extraction were studied and the characteristics of the obtained pectin were analyzed. The results showed that approximately 95% anthocyanins (125.4 mg/100 g dried peels) were extracted under the best conditions such as 80% ethanol (v/v), 1:25 (g/mL) solid/liquid ratio, 40°C incubation temperature, and 10 minutes sonication time. The findings demonstrated the antioxidant and cytotoxic activity of KB epithelial cells of the anthocyanin extract. Additionally, 7.47% of pectin from the residues after extraction anthocyanins were extracted by citric acid with pH 2 at 87°C for 90 minutes. The pectin has 68.34% purity, and 57.14% of DE, and its structure was confirmed by FT-IR spectra. This study can be utilized to recover useful components from purple passion fruit peel waste, improving the fruit’s value and reducing the environmental impacts of its peels.

This study addresses the crucial issue of predicting student performance in educational data mining (EDM) by proposing an Adaptive Dimensionality Reduction Algorithm (ADRA). ADRA efficiently reduces the dimensionality of student data, encompassing various academic, demographic, behavioral, social, and health-related features. It achieves this by iteratively selecting the most relevant features based on a combined normalized mean rank of five feature ranking methods. This reduction in dimensionality enhances the performance of predictive models and provides valuable insights into the key factors influencing student performance. The study evaluates ADRA using four different student performance datasets and six machine learning algorithms, comparing it to three existing dimensionality reduction methods. The results show that ADRA achieves an average dimensionality reduction factor of 6.2 while maintaing comprable accuracy with other mehtods.

During the rainy season, Can Tho city frequently faces severe flooding on its streets. In this study, the investigation is carried out on 30 streets and 10 canals nearby the streets in the center of Can Tho city. The results indicate that the surveyed manholes contain a lot of sludge with an average volume percent of 39.29%. In the food service areas, the average volume percent of sludge in manholes is found more than 70%. In the concentrated residential areas, the amount of sludge is less, but still at a relatively high rate (over 50%). In addition, the results show that the studied canals in the inner city are polluted due to waste directly from the drainage system. These issues have an effect on the drainage capacity of the roads. Some discussion on sand also shows that the sand shortage has reached an alarming level, which is the main factor leading to slow progress of some road projects. The sand reserves in the Mekong Delta region decrease sharply and the scarcity of sand causes sand prices to skyrocket, which is a difficult problem for this area. The development of mobile sludge treatment technology to produce a replacement material suitable for levelling and fertilizer purposes can be a potential topic for future research.

Soil cement mixing (SCM) using a high-pressure grouting method (Jet grouting), considered an improvement solution for soft soil has been popular in countries, especially in Japan and other countries in Northern Europe. However, the implementation of Jet grouting is still quite modest in the Mekong Delta. In this study, the depth effect on the compressive strength of soil-cement mixing is conducted at the Can Tho River embankment project. The results show that the uniformity of SCM depends on the cement content. The higher cement content gives a better distribution of compressive strength from the bottom to the top of SCM. In this study, the cement content of 400 kg/m3, considered the suitable content for the Jet-grouting method in Can Tho, is much higher than in (TCVN 9906:2014).

This study was carried out to optimize the treatment process of methyl blue (MB) in aqueous solution using dielectric barrier discharge (DBD) plasma and experiments were designed by using response surface methodology and central composite design (RSM-CCD). Four independent factors such as plasma power, liquid flow rate, air flow rate, and exposure time were investigated. According to the analyzed results of RSM, the experimental data is best fitted with a model of the quadratic polynomial with regression coefficient values of more than 0.9 for all responses. At optimal degradation conditions, the plasma power, liquid flow rate, air flow rate, and exposure time were 100 W, 1.5 lpm, 6 lpm, and 108.8 minutes respectively and the concentration of methyl blue was reduced to 95.8% with a concentration of 1.06 ppm. The degradation of methyl blue followed kinetic reaction rate was r = 1.6 10-3[MB]2.2.

This study was conducted to find a facile method for preparing dicalcium phosphate anhydrous (DCPA) from the bones of Nile Tilapia, recovered from a by-product of the fillet process. The by-product containing bones of the Nile Tilapia collected from a local factory was stewed in boiling water and treated with NaOH solution to remove organic impurities from the obtained bones of Tilapia. The pre-treated bones were then calcined and ground to a fine powder before converting to dicalcium phosphate anhydrous. The factors affecting the yield of DCPA such as precipitation pH, reaction temperature, and reaction time were investigated. Modern analytical methods, such as XRD, SEM, XRF, and TGA were employed to characterize the DCPA. The DCPA product with high crystallinity (~ 98.5%) with particle sizes ranging from 1 to 3 µm was obtained at pH 5, 90 min. reaction, and 80°C. This study showed a facile and viable method for producing dicalcium phosphate anhydrous from the bones of Nile Tilapia.

Using “green solvents” like ethylene glycol (EG) to replace water in hydrometallurgical processes is increasingly popular because of its feasibility and environmental friendliness advantages. In this study, the selective recovery behavior of Co(II) over Ni(II), Al(III), and Li(I) from mixed EG and H2O of HCl solution was studied by a combination of solvent extraction and stripping precipitation. The results showed that Co(II) from the EG-H2O solutions was selectively extracted over other metals by ionic liquids, in which ALi-SCN was more efficient than Aliquat 336. The presence of EG offered significant advantages in selectivity and efficiency for Co(II), whereas the effect of HCl concentration in the EG-H2O system was negligible. The selective extraction behavior of ALi-SCN for Co(II) is due to differences in the stability and speciation of metal complexes in the EG-H2O solution. Co(II) from the loaded ALi-SCN was directly precipitated to cobalt oxalate with above 99.9% purity under conditions: 60 min, O/A ratio of 1, and 1:2 of mole ratio of Co(II) to H2C2O4. ALi-SCN solutions after the Co(II) precipitation can be reused several times with selective Co(II) extraction capacity at high performance. Thus, Co(II) recovery from an EG-H2O system through continuous two steps of ALi-SCN extraction and precipitation is feasible.

Agrobacterium-mediated transformation is the most efficient method to transfer gene of interest into the plant genome. However, the transformation efficiency of this method with indica rice varieties is still low and needs to be improved. In this study, the Agrobacterium-mediated method was used to transfer reporter genes into the Nang Thom Cho Dao, an indica rice variety. Different transformation parameters, such as selection to used hygromycin at concentrations of 0, 25, 30, 40, and 50 mg/L, bacterial density, and infected duration, were tested and optimized. The results showed that 30 mg/L of hygromycin was the most appropriate concentration for selecting transgenic callus in Nang Thom Cho Dao. In addition, the highest transformation efficiency of this Nang Thom Cho Dao rice cultivar was observed at the bacterial suspension density OD600nm of 0.1, the infected duration of 20 minutes, and the 3-day co-culture period. The presence and expression of transgenes were confirmed by gus staining and PCR with specific primers for hptII and gus genes. This transformation procedure should be used for further studies in genetic engineering of Nang Thom Cho Dao and other indica rice varieties.

Smart parking systems along with that is continuous development of new technologies, are widely applied to improve our lives. It can also add new technologies with advanced functions making it a multi-functional management system. Thanks to the anti-theft technologies that are installed, modern cars are significantly more difficult to steal than they once were. However,  electrical systems can still experience issues, though and malfunction at some point. This paper suggests using video image recognition technology, at car parks and parking lots as an anti-theft solution, alerting the presence of the non-owner of vehicle in the driver’s seat. The system automatically predicts whether the driver is valid with the registration number plate. The image of the car is captured by the camera at the entrance gates of the parking lot. The proposed algorithm includes face recognition in images, building a deep learning convolutional network that classifies faces (subscriber’s images); using Cascade trainer to train number plate object recognition, vehicle number recognition through character recognition technique. The system can recognize reality through a personal computer connected to the camera at the scene or through photos and video files. Result, the model can face recognition and match to license plate in at a moment.