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This paper investigates the influence of piston geometry design and spark plug position on the engine performance and emission characteristics at a range of speeds from 1200 rpm to 2200 rpm. Accordingly, the parameters of the indentation depth, the spark plug position, the location of the recess, and the engine's compression ratio are changed and evaluated. The concave center depth improved the mixture of air and fuel, increased power, and reduced fuel consumption. The power can be improved by up to 3% when the piston top recess is 25 mm. In addition, within a limited range, the combustion process and the engine's power and emission characteristics are enhanced when the engine's compression ratio rises. Increasing the depth of the depression on the top of the piston improves fluid flow in the cylinder, resulting in increased power, fuel efficiency, and emissions; however, the improvement between the indentations remains unclear.

This paper develops a computer vision system integrated with a SCARA robot arm to pick and place objects. A novel method to calculate the 3D coordinates of the objects from a camera is proposed. This method helps simplify the camera calibration process. It requires no knowledge of camera modeling and mathematical knowledge of coordinate transformations. The least square method will predate the Equation describing the relationship between pixel coordinates and 3D coordinates. An image processing algorithm is presented to detect objects by color or pixel intensity (thresholding method). The pixel coordinates of the objects are then converted to 3D coordinates. The inverse kinematic Equation is applied to find the joint angles of the SCARA robot. A palletizing application is implemented to test the accuracy of the proposed method. The kinematic Equation of the robot arm is presented to convert the 3D position of the objects to the robot joint angles. So, the robot moves exactly to the required positions by providing suitable rotational movements for each robot joint. The experiment results show that the robot can pick and place 27 boxes on the conveyor to the pallet with an average time of 2.8s per box. The positions of the boxes were determined with an average error of 0.5112mm and 0.6838mm in the X and Y directions, respectively.

Unmanned Aerial Vehicles (UAVs) are envisioned to play a key role in the Sixth-Generation (6G) and Beyond Fifth-Generation (B5G) networks. Resolving spectrum constraints in UAV communications remains a critical issue. This article investigates Full-Duplex (FD) UAV-aided Non-Orthogonal Multiple Access (NOMA) to effectively utilise the scarce wireless spectrum. Specifically, exact closed-form formulas for the outage probability of FD UAV-aided NOMA have been developed. The results are validated using Monte Carlo simulation in 3GPP UMi conditions to provide practical guidelines for real-world deployment. In low transmission power regimes, the results also reveal that FD UAV-aided NOMA has a lower outage probability at the downlink Ground Users (GUs) than HD UAV-aided NOMA. At high transmit power regimes, FD UAV-aided NOMA is limited by residual SI at the UAV and interference from the UAV to the GUs. The numerical results also show that the transmission power at the UAV should be significantly lower than that at the Ground Base station (GB) to ensure low outages at the GUs.

The influence of different synthesis parameters on CeO _2 and Pt nanoparticle (NP) deposition on Ketjenblack carbon (C(KB)) was examined. The Pt NP diameter (3.1–4.1 nm) was not influenced by CeO _2 synthesis parameters. The CeO _2 NPs synthesized using ultrasound sonication contribute to a better durability of the Pt–CeO _2 /C against CO poisoning. In contrast, CeO _2 synthesized using the microwave heating method contributes to better methanol oxidation reaction (MOR) activity at low electrode potential. Synthesis parameters of CeO _2 and Pt NPs developed for the C(KB)-based catalysts were applied for C(Cr _3 C _2 )-based catalysts. The Pt NP diameter of C(Cr _3 C _2 )-based catalysts was slightly higher (7.2 nm) as some Pt NPs were agglomerated. The C(Cr _3 C _2 ) support facilitates the MOR and CO stripping, especially in the case of the Pt/C on C(Cr _3 C _2 ) support. The MOR activity at 0.85 V of Pt NPs on the C(Cr _3 C _2 ) support is as good as the MOR activity for the best Pt–CeO _2 on the C(KB) support. The C(Cr _3 C _2 ) support also improves the CO removal from the Pt surface. All the synthesized catalysts had better MOR activity than the commercial Pt/C(Vulcan) catalyst. The oxygen reduction reaction activity of Pt–CeO _2 /C catalysts with higher CeO _2 content synthesized with the microwave heating method was very good.

In 2017, Global Initiative for Chronic Lung Disease (GOLD) made substantial changes to its ABCD group categorization. Although several studies had been conducted to assess the impact of the new GOLD category, there was no research on the change of the GOLD classification in Vietnam. This retrospective analysis was conducted at Asthma and COPD clinic at the University Medical Center in Ho Chi Minh City, Vietnam. Our study population comprised patients visiting Medical Center from January 2018 to January 2020. We categorized patients’ demographic, clinical characteristics and pharmacotherapy based on GOLD 2011 and 2017 guidelines. A comparison between the two versions was also determined. A total of 457 patients were included in this study. The percentage of groups A, B, C and D according to GOLD 2011 was 5%, 20.8%, 13.1% and 61.1%; and according to GOLD 2017 was 6.1%, 34.1%, 12% and 47.8%, respectively. In terms of gender, male patients constituted nearly 95% of the study’s population (433/457 patients). Regarding pharmacotherapy, approximately 20% of the low-risk group (group A-B) was overtreated with ICS components: LABA+ICS (15.8%) and LAMA+LABA+ICS (3.8%). There were 13.3% and 1.1% of patients transferred from D to B and from C to A, respectively. All of them had lower FVC% pred, FEV1% pred and FEV1/FVC than the patients remained in group B or A (p

Green asparagus is widely consumed fresh due to its high nutritional value and a low calorie content. However, its short shelf-life due to a high water content causes high postharvest losses. In this study, we aimed to develop an innovative asparagus herbal drink to ease postharvest losses and diversify asparagus-derived products. We investigated the effects of process parameters on the quality of the herbal drink from green asparagus. In particular, we determined the optimal length and grinding size for asparagus and selected suitable blanching and drying methods. Analytical responses included the contents of total soluble solids, polyphenol, carbohydrates, and vitamin C, as well as the visual appearance of asparagus samples. The length of 5 mm was found suitable for subsequent steps as it facilitated an increase in solute in the asparagus infusion. Microwave blanching and convective drying were selected to achieve high contents of total soluble solids, polyphenol, carbohydrates, and vitamin C in the asparagus infusion. Dried asparagus ground into 1.5–2.0 mm particles was packaged into tea bags. The asparagus infusion subjected to sensory evaluation had a yellowish color, a characteristic asparagus flavor, and a relatively sweet taste. Total soluble solids in the infusion amounted to 26%. Our results showed a possibility of developing an asparagus herbal drink which could be a potent product in the commercial market. Therefore, further large-scale studies of the asparagus herbal drink should be carried out to enhance its feasibility in the food industry.

Honey is a natural product made by honeybees, its composition depends on factors such as climate, soil and plant source. In this study, the nutritional parameters, phenolic composition, antioxidant activity and antibacterial ability of 30 different types of honey of different botanical and geographical origins in Vietnam were investigated. The study focused on the characterization and evaluation of the influence of plant origin and geographical location on physical–chemical properties and biological activities (antioxidant and antibacterial). The obtained results show that all honey samples meet quality standards according to international standards and Vietnamese standards, except for some exceptions recorded in moisture, 5-hydroxymethylfurfural (HMF) value and ash. These samples were explored for the detection of 13 polyphenols by using high-performance liquid chromatography (HPLC). The classification of honey samples collected from different regions and botanical sources was performed by principal component analysis (PCA), and it was observed that certain phenolic compounds contributed to the identification of honey samples. In addition, the correlation between physicochemical properties, chemical composition and biological activity of most honeys was also first clarified in this study. Overall, our data provide an overview data set and essential results in creating a database on the world honey trait map.

Introduction: The 12-item Vietnamese smell identification test (VSIT) has been developed to evaluate the olfactory function of the Vietnamese population. This study aimed to investigate the normative value of the VSIT in different age groups and sexes. Methods: This cross-sectional study was conducted at Ho Chi Minh University Medical Center, Vietnam. All participants were evaluated for odor identification ability using the VSIT. We included healthy participants aged 18 years or older with no history of olfactory disturbances. Results: A total of 391 healthy volunteers were recruited with a mean age of 45.80 years (SD: 17.62; range: 18–86; female: 63.4 %). The tenth percentile of scores on the 0–12 VSIT scale was 8.3 in participants aged 18–29 years, 9.0 in 30–39 years, 8.0 in 40–49 years, 7.8 in 50–59 years, 7.9 in 60–69 years and 6.0 in over 70 years. Young adults (18–39 years old) had better olfactory identification ability than older adults (over 50 years), p