Suitability assessment and recommendations for Urban agricultural development: A case study in Cai Rang District, Can Tho City, Viet Nam

This study aimed to assess the contributing aspects and design decentralized adaptive models for urban agriculture. The research techniques included data collection, surveying and interviewing farmers, statistical analysis and FAO land suitability assessment techniques. The results show that the model of growing green vegetables, fruits and vegetables outside, together with decorative plants, orchids and raising cattle, is the most effective. Moreover, job-creating models boost income, calm down people, spread joy, supply clean food right away, provide room for greenery, recycle agricultural waste and reduce environmental pollution. The outcome is the foundation for selecting the best foreign investment model for future growth. According to the study's findings, sustainable agricultural options for the area assist people in living better, protecting the environment, and earning more money in the future

Effects of Frequency and Mass of Eccentric Balls on Picking Force of The Coffee Fruit for The As-Fabricated Harvesting Machines

Currently, Vietnam ranks second about the coffee export in the world. To match that position, the use of coffee harvesting tools/machines according to the automatic trend is essential. However, the most common forms of coffee harvesting in Vietnam are manual, improved manual-coffee picking machines that are imported from foreign countries. The above harvesting forms have low productivity and have some disadvantages such as labor cost, labor hiring, high labor cost, and long harvesting time, low harvesting, and post-harvesting quality. Studies of scientists around the world have applied the principle of vibration to produce the picking force for coffee fruits, and the picking force is known to be different from many factors in every region of the world growing coffee. The paper presents the method of design and manufacturing an automatic coffee harvesting machine based on the evaluation of picking force for coffee in Vietnam. The influences of eccentric ball mass and vibrating frequency on the magnitude of the picking force are carefully calculated. On that basis, the experimental programming is applied to find the optimal working point of the picking machine for coffee. The results showed that the eccentric ball mass of 8.5 kg, the rotation speed of the eccentric ball from 480 to 574 rpm would produce the picking force by the coffee fruit of Vietnam

Impact of foaming conditions on quality for foam-mat drying of Butterfly pea flower by multiple regression analysis

In recent years, the Butterfly pea flower has been increasingly interested in its color and function. However, the preservation of the extract faced many difficulties; therefore, foam drying technology was applied to solve this problem. The study was conducted to determine the effect of foaming conditions, including albumin ratio, carboxymethyl cellulose (CMC) ratio, and whipping time on foam characteristics. At the same time, the multi-dimensional regression method was also used to determine the most suitable foaming conditions for the following process. The research results showed that all 3 factors strongly influenced the foaming process of pea flower extract. It could be concluded that the most suitable condition for foaming is to use 9.3% albumin, 0.79% CMC and stir for 19 min. Under these conditions, the foam expansion and stability were 584.79% and 96.44% respectively. The powder obtained from the foam drying of Butterfly pea flower extract was also analyzed for quality. The temperature of 65 oC for 4 hrs gave relatively high-quality powder with protein content, anthocyanin and antioxidant activity of 9.89 g/100g, 1.15 mg/g and 87.34% respectively. In conclusion, the foam-mat dried powder from butterfly pea flower extract is suitable for other processing processes, especially in the processing of folk cakes, pasta and bread industry

Effect of humate and controlled released NPK fertilizers (NPK-CRF) on rice yield and soil fertility of intensive alluvial soils

The study aims to assess the effect of mixed fertilizers, including controlled slow-release NPK (NPK-CRF) and urea, potassium humate fertilizers, on soil fertility and rice yield. The on-Farm Trials experiment was carried out on alluvial soil, with two models corresponding to two farming techniques: (i) Traditional fertilization, applying conventional fertilizers with the formula 92.2 N–82.8 P2O5–22.8 K2O kg/ha; (ii) New generation fertilizers (NPK-CRF, urea humate, and potassium humate) with the formula 50.1 N–39.9 P2O5–30.0 K2O. Each pattern was repeated three times, corresponding to 3 farmers. Each household's area is 1,000m2, cultivating continuously through three seasons of Winter-Spring (WS), Summer-Autumn (SA), and Autumn-Winter (AW) in Chau Thanh A district, Hau Giang province. The results showed that the new generation fertilizer application significantly improved rice yield and yield composition of the Winter-Spring cropping season (6.92 tons/ha), Summer-Autumn (5.94 tons/ha), and Autumn-Winter (6.15 tons/ha), which are different from farmers' fields. Furthermore, the combined application of NPK-CRF, urea-humate, and K-humate fertilizers for rice in SA and AW crops significantly reduced the total acid content, Al3+ exchange in the soil, and improved soil fertility of pH, N, and available P, organic matter (%C). However, there was no difference in soil's physical properties over the three farming seasons. Finally, adding humic acid to controlled-release fertilizer can improve soil fertility, and increase yield and yield components, nitrogen uptake, enhance nitrogen usage efficiency, all of which have positive yield and soil consequences

Effect of phosphate fertilizer-coated Dicarboxylic Acid Polymer on rice yield and components under greenhouse conditions

A significant amount of phosphorus (P) becomes fixed by aluminium (Al) and iron (Fe) in acidic soils, leading to decreased efficiency in P utilization and subsequently lowering crop yield. Enhanced P fertilization offers a potential solution, as the dicarboxylic acid polymer (DCAP) coating on P fertilizer promotes increased plant productivity and more effective P utilization. The improvement achieved through enhanced P fertilization can contribute to higher rice yields in acidic soils, accompanied by an increase in P solubility. The study aimed to determine the impact of DCAP-mixed phosphate fertilizer on P uptake by plants, absorption efficiency, and rice yield. The results demonstrated a significant increase in available P (about 3.5 mg P/kg) when DCAP was used in a greenhouse setting, resulting in elevated yields and total P absorption (ranging from 0.03 to 0.05 grams/pot). However, the addition of 60 kg of phosphate mixed with DCAP has not yet demonstrated a significant increase in available phosphorus in the soil compared to adding just 60 kg of phosphate. The application of phosphate at a dose of 30 kg of P2O5 mixed with DCAP for growth and phosphorus absorption yield results equivalent to using 60 kg of P2O5 without DCAP. Furthermore, the use of DCAP in conjuction with 50% P fertilizer increased P availability by the same amount as that achieved with 100% P fertilizer. Consequently, DCAP reduced chemical P fertilizer in the soil by approximately 50%. However, it is essential to evaluate the effectiveness of mixed phosphate fertilizer (DCAP) under field conditions before recommending its widespread use

TRANSFORMING EXTENDED ENTITY-RELATIONSHIP MODEL INTO OWL ONTOLOGY IN TEMPORAL DATABASES

Many previous systems were built based on the ER model, so the upgrading and transforming the ER model into ontology for reducing cost is really necessary. There are several studies aim at transforming from ER and EER model into ontology. However, these studies have not classified the semantic of the recursive relationship in ER model, so the semantic of the recursive relationship will be easily lost during the transformation. Also, the studies have not mentioned the designing of the ontology that supports temporal attributes based on the temporal ER model. This paper discusses the semantic classification of the recursive relationship and TimeER model (extended EER in temporal databases) and OWL ontology. And propose a method to transform into OWL ontology

A study of 3D modelling the vibrations induced from grab shock at the Metro Line 3 project in Hanoi

The density of high-rise building is increasing over recent years in urban city. Construction activities, particularly piling processes, D-wall excavation, are paid attention due to ground borne vibrations. The impact of vibrations induced from construction activates on existing buildings is discussed in the past and so on. However, there is rarely study their vibrations in Vietname specially in construction activities such as grab shocking. Continuing the analytical and experimental studies of the grab shocking in the Metro Line 3 project in Hanoi, 3D modelling of vibrations induced from the grab shocking on the existing building is carried out by Plaxis software. The hardening soil model is used and the acceleration of the grabin the bentonite slurry is considered in the model. The comparison between the analytical solution and the 3D simulation is highlighted in the paper to show the accuracy and robustness of the 3D modeling. This study is applied to investigate the vibrations on existing building in the Metro Line 3 project and to control the grab drop length as well as the distance of existing building to the vibration source

Extracting Fetal Electrocardiogram from Being Pregnancy Based on Nonlinear Projection

Fetal heart rate extraction from the abdominal ECG is of great importance due to the information that carries in assessing appropriately the fetus well-being during pregnancy. In this paper, we describe a method to suppress the maternal signal and noise contamination to discover the fetal signal in a single-lead fetal ECG recordings. We use a locally linear phase space projection technique which has been used for noise reduction in deterministically chaotic signals. Henceforth, this method is capable of extracting fetal signal even when noise and fetal component are of comparable amplitude. The result is much better if the noise is much smaller (P wave and T wave can be discovered)

Evaluation of water loss and solute uptake during osmotic treatment of white radishes (Raphanus sativus L.) in salt-sucrose solution

White radish, scientifically known as Raphanus sativus L., is a yearly vegetable. Currently, it was being grown and widely used in the world, including Vietnam. These plants have been used as food or food processing. The osmotic treatment of vegetables involves the removal of water from plants in which the solids from the osmotic solution are transported to the plant material by osmosis. By this procedure, sucrose and saline solution are usually performed. White radishes were dehydrated in different hypertonic solutions by combined sucrose and NaCl at three different concentrations, including 9 runs. Mass transfer behaviour was applied according to three common models such as Fick’s second law, Weibull and Peleg’s equations based on the change of moisture and solid content of white radish during osmotic dehydration. The obtained results showed that the mass transfer was fast at initial stage and became slowly at the later stage. The effective moisture (Dm) and solid diffusivities (Ds) were ranged from 1.0186 to 1.2826x10-8 and from 1.0692 to 2.3322x10-8 (m2/s) respectively. The Peleg’s equation was found to be the best fitting for water loss and solid uptake thanks to the high determination coefficient (>97.64%) and the low average relative error (<3.174%). Raised up solution concentration resulted in higher water loss and mass gain