206 research outputs found
Factors Affecting Youtube Acceptance For Student Learning Needs
This study was conducted to demonstrate the factors that influence Vietnamese students’ acceptance of YouTube for educational purposes. Qualitative and quantitative research methods are combined to test the research hypotheses. Research data was collected using quota sampling, with a sample size of 306 students studying at universities in Vietnam. Structural equation modeling (SEM) helps demonstrate that five factors positively affect the intention to use YouTube for student learning needs. These factors include performance expectancy, effort expectancy, hedonic motivation, social influence, and flexibility. Furthermore, research has demonstrated the positive impact of intentional use on the behavioral usage of YouTube for the educational requirements of Vietnamese students. The study provides a valuable reference for educational administrators and researchers
Whole-genome sequencing of three local rice varieties (Oryza sativa L.) in Vietnam
Recently, a new technology, Next-generation sequencing (NGS) has been launched and providing whole-genome sequences that helps identify molecular markers across the genome. DNA markers such as single nucleotides and insertion – deletion (InDel) polymorphisms were widely used for plant breeding particularly to distinguish important traits in rice. These PCR-based markers can be used for the precision detection of polymorphisms. Moreover, PCR-based approaches are simple and effective methods for dealing with the issue of fraudulent labeling and adulteration in the global rice industry. In this study, three local varieties of Oryza sativa L. in Vietnam were sequenced with up to ten times genome depth and at least four times coverage (~83%) using the Illumina HiSeq2000™ system, with an average of 6.5 GB clean data per sample, generated after filtering low-quality data. The data was approximately mapped up to 95% to the reference genome IRGSP 1.0. The results obtained from this study will contribute to a wide range of valuable information for further investigation into this germplasm
SYNTHESIS OF SILVER NANOPARTICLES DOPED IN THE ZEOLITE FRAMEWORK BY CHEMICAL REDUCTION METHOD
ABSTRACT Silver ions (Ag+) were introduced at first into the porous zeolite 4A lattice by an ion-exchange route. And then silver nanoparticles (AgNPs) were synthesized in the zeolite framework by chemical reduction method using hydrazine hydrate (N2H4. H2O) as reducing agent. The synthesized AgNPs/zeolite product was characterized by ultraviolet-visible spectroscopy (UV-vis), X-ray diffraction (XRD), transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDX). The results showed the maximum absorption wavelength (lmax) of AgNPs/zeolite at 427 nm and the average size of the metallic AgNPs doped in the zeolite of about 30 nm. The synthesis process has been considered as suitable one to prepare AgNPs/zeolite with AgNPs content in zeolite of about 1.2% on large scale. The obtained AgNPs/zeolite product has been used for production of porous ceramic water filters with efficiently bacterial disinfection effect for treatment of drinking water
Optimizing Boiler Efficiency by Data Mining Teciques: A Case Study
In a fertilizer plant, the steam boiler is the most important component. In order to keep the plant operating in the effective mode, the boiler efficiency must be observed continuously by several operators. When the trend of the boiler efficiency is going down, they may adjust the controlling parameters of the boiler to increase its efficiency. Since manual operation usually leads to unex-pectedly mistakes and hurts the efficiency of the system, we build an information system that plays the role of the operators in observing the boiler and adjusting the controlling parameters to stabilize the boiler efficiency. In this paper, we first introduce the architecture of the information system. We then present how to apply K-means and Fuzzy C-means algorithms to derive a knowledge base from the historical operational data of the boiler. Next, recurrent fuzzy neural network is employed to build a boiler simulator for evaluating which tuple of input values is the best optimal and then automatically adjusting controlling inputs of the boiler by the optimal val-ues. In order to prove the effectiveness of our system, we deployed it at Phu My Fertilizer Plant equipped with MARCHI boiler having capacity of 76-84 ton/h. We found that our system have improved the boiler efficiency about 0.28-1.12% in average and brought benefit about 57.000 USD/year to the Phu My Fertilizer Plant
Dynamic stiffness method for free vibrations analysis of partial fluid-filled orthotropic circular cylindrical shells
Free vibrations of partial fluid-filled orthotropic circular cylindrical shells are investigated using the Dynamic Stiffness Method (DSM) or Continuous Element Method (CEM) based on theFirst Order Shear Deformation Theory (FSDT) and non-viscous incompressible fluid equations. Numerical examples are given for analyzing natural frequencies and harmonic responses of cylindrical shells partially and completely filled with fluid under various boundary conditions. The vibration frequencies for different filling ratios of cylindrical shells are obtained and compared with existing experimental and theoretical results which indicate that the fluid filling can reduce significantly the natural frequencies of studiedcylindrical shells. Detailed parametric analysis is carried out to show the effects of some geometrical and material parameters on the natural frequencies of orthotropic cylindrical shells. The advantages of this current solution consist in fast convergence, low computational cost and high precision validating for all frequency ranges
An Assessment of the Values of French Colonial Townhouses in Hanoi Towards A More Sustainable Conservation
As the capital city of French Indochina, Hanoi was well planned by the French and immensely invested in the construction of public buildings as well as houses. In addition to public buildings and villas designed in French colonial styles that shaped the so-called distinctive architectural heritage in Hanoi throughout the colonial years, a large number of townhouses built during 1920 - 1950 which formed the cityscape of Hanoi in the first half of the 20th century should be noted. After nearly 70 years since the French army withdrew from the city, the number of French townhouses has considerably decreased. The remaining houses have shown that this is a real “treasure” that needs to be conserved because of their important values, not only in terms of urban architecture but also in cultural and historical aspects. However, a fact requiring special attention is that French townhouses in Hanoi - unlike French public buildings and villas - have not yet been recognised as heritage so that they can be kept to avoid the risk of deterioration or demolition under the impact of rapid urbanisation in the market economy. One of the main reasons for this negative urban development is that there has been no concrete or comprehensive rating system to assess the values of those townhouses which will closely correspond to their characteristics and contexts. Therefore, the authors - based on site surveys and by applying some appropriate methods such as expert consultations and case studies - have developed a full set of criteria to help evaluate those remaining townhouses as accurately as possible. This system can be used as a basis for a systematic assessment and classification towards a more effective conservation and even promoting the values of those townhouses with regard to the development of a modern society and in consideration of sustainable heritage conservation as a mainstream in the world.
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