Fundamental efficiency bound for coherent energy transfer in nanophotonics

We derive a unified quantum theory of coherent and incoherent energy transfer between two atoms (donor and acceptor) valid in arbitrary Markovian nanophotonic environments. Our theory predicts a fundamental bound $\eta_{max} = \frac{\gamma_a}{\gamma_d + \gamma_a}$ for energy transfer efficiency arising from the spontaneous emission rates $\gamma_{d}$ and $\gamma_a$ of the donor and acceptor. We propose the control of the acceptor spontaneous emission rate as a new design principle for enhancing energy transfer efficiency. We predict an experiment using mirrors to enhance the efficiency bound by exploiting the dipole orientations of the donor and acceptor. Of fundamental interest, we show that while quantum coherence implies the ultimate efficiency bound has been reached, reaching the ultimate efficiency does not require quantum coherence. Our work paves the way towards nanophotonic analogues of efficiency enhancing environments known in quantum biological systems.Comment: 5 pages, 4 figure

The perspective of psychology students on the areas of psychology

Perception is defined as the result of an awareness process about phenomena, things (living animals, plants, or humans), connections between objects by activities including noticing, observing, differentiating, and acknowledging. A recent study was conducted to investigate the undergraduate’s perception of areas of psychology. This research used the Vietnamese version of the Scale of Interests by Areas of Psychology (EIAPsi), including ten subscales to survey 252 psychology students (57 males and 195 females) from four universities in Vietnam. The findings showed significant effects of university and major on psychology undergraduate’s perception of areas of psychology. Students majoring in Counseling and Clinical Psychology had more general knowledge about the functions and roles of Clinical and Health Psychology and Neuropsychology than other undergraduates. Industrial and Organizational Psychology students had more general knowledge about Organizational Psychology than students in other majors

Genetic diversity of two successive generations of selection in bighead catfish (Clarias macrocephalus) populations

Selective programs associated with domestication can improve fish production but also can have an impact on broodstock’s genetic diversity. In this study, the genetic diversity of original sources (G0) from wild and cultured bighead catfish populations, as well as the two successive generations (G1 and G2) subjected to selection experiments, was assessed. G0 wild adults were collected in Ca Mau conservation area and G0 cultured fish were from a hatchery in Can Tho. The G1 fish included pure crosses and crossbreeds of G0, while G2 was the offspring of the selected G1. Fin clips from 27 to 29 individuals of each fish group were randomly sampled for genetic analysis. The amplification results using six ISSR primers showed that the genetic diversity was relatively higher in G0 (effective number of alleles Ne from 1.43 to 1.49; heterozygosity He from 0.265 to 0.290) than in G1 (Ne = 1.32±0.04; He = 0.201±0.023) and G2 (Ne = 1.34±0.04; He = 0.216±0.023). Genetic differences increased between the original populations and the descending generations. To reduce the detrimental impacts of low genetic diversity in domesticated bighead catfish in the Mekong Delta, it is recommended that broodstock in later generations should be produced in a larger..

Analysing factors influencing land use planning for sustainable land resource management in Vietnam: a case study of Dan Phuong district in Hanoi city

Land use planning is an important task for every country in the world to ensure the sustainable use of land resources for economic and social development activities. However, many land use plans have not achieved their desired effectiveness due to a lack of consideration and evaluation of factors affecting the land use planning implementation process. This study was conducted to answer the following question: what are the main factors influencing the land use planning process in Vietnam? In this study, we use multivariate regression to identify the main factors influencing land use planning in Vietnam, including the economic factor group; institutional and policy factor group; urbanisation factor group; planning factor group; social factor group; environmental factor group; and organisational and implementation factor group. The results identified five groups of factors influencing land use planning in the Dan Phuong district through the influencing factor analysis method, including policy (Po), economy (Ec), society (So), environment (En), and others (Ot). In addition, the linear regression model obtained for land use planning in Dan Phuong district is as follows: land use planning = 0.408Po + 0.454Ec + 0.398So + 0.368En + 0.259Ot. In which the group of factors with the strongest influence was the Eco factors (β = 0.454), the second was the Po factors (β = 0.408), the third was the So factors (β = 0.398), the fourth was the En factors (β = 0.368), and lastly, there were the Ot factors (β = 0.259). The results of the analysis were used to plan land use effectively and according to local conditions. This can help managers to find solutions for the sustainable use of land resources in the future

分子遺伝学的手法を用いたわが国メロン品種の多様性と分類

For the breeding of Japanese netted melon, various types of foreign cultivars have been utilized for improving adaptability, disease and pest resistance, fruit quality and so on. However, little is known about their genetic diversity and relationships, since most cultivars derived from crosses between various horticultural groups. To figure out the genetic structure of Japanese melon, in this study, 57 melon accessions from three horticultural groups were examined using 55 RAPD markers produced by 24 RAPD primers. Genetic diversity of the Japanese netted melon was as high as those of cultivar groups of Groups Cantalupensis and Inodorus, while it was low in Group Conomon irrespective of large variations in fruit traits. Cluster analysis and PCO analysis based on genetic distance showed that Group Conomon was distantly related to other melon accessions. Among the latter, European cantaloupe (nonnetted) and American open-field type (netted) proved to be genetically close, while England glasshouse melon (netted) including ‘Earl’s Favourite’ is distantly related to these two groups and closely related with Group Inodorus. It was therefore suggested that England glasshouse type was established from hybrids between European cantaloupe and Group Inodorus. Japanese netted melon was most closely related with England glasshouse type, irrespective of the fact that various kinds of melon accessions have been crossed to improve adaptability, disease resistance and so on. In contrast, pure line cultivars of the Japanese netted melon bred by pure line selection from ‘Earl's Favourite’ or by crossing ‘Earl’s Favourite’ with ‘British Queen’ were confirmed to be mostly homogenous, and it was difficult to establish RAPD markers to discriminate each cultivar. Group Conomon var. makuwa and var. conomon, which have been cultivated and utilized as different crops, proved to be genetically indistinguishable and were considered to share the same gene pool

Effect of Polypyrrole on the Electrical, Dielectric and Mechanical Properties of Waterborne Epoxy Coatings

In this context, conducting composite based on waterborne epoxy system and polypyrrole (PPy) was investigated. The polypyrrole was synthesized by chemical oxidation polymerization. Its morphology and chemical structure were confirmed by using field emission scanning electron microscopy (FESEM) and Fourier transform infrared spectroscopy (FTIR). Then, PPy was well-dispersed in the epoxy coating and had a good compatibility with the matrix. The effects of PPy on dielectric, electrical and mechanical properties of epoxy/PPy composites was examined. The dielectric constant and electrical conductivity of the coatings increased with addition of PPy fillers. Over to 15 wt. % of PPy loading, the volume resistivity of samples slightly decreased from 6.7 × 1010 to 1.5 × 1010 Ω cm. In contrast, the presence of PPy diminished both impact and abrasion resistance of the epoxy/PPy composites, down to 160 kg cm and 10.2 L/mil, respectively, but they stayed acceptable for the coatings. The results reveal that the epoxy containing polypyrrole is suitable for various electrical and dielectric applications

Catalytic Dye Oxidation over CeO2 Nanoparticles Supported on Regenerated Cellulose Membrane

A novel regenerated cellulose (RC) membrane containing cerium oxide (CeO2) nanoparticles is described in detail. In this work, CeO2 nanoparticles with high surface area and mesoporosity were prepared by a modified template-assisted precipitation method. Successful synthesis was achieved using cerium nitrate as a precursor, adjusting the final pH solution to around 11 by ammonium hydroxide and ethylene diamine, and annealing at 550 °C for 3 hours under a protective gas flow. This resulted in a surface area of 55.55 m².g–1 for the nanoparticles. The regenerated cellulose membrane containing CeO2 particles was synthesized by the novel and environmentally friendly method. The catalyst CeO2 and cellulose/CeO2 membrane were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Electron paramagnetic resonance (EPR), and Brunauer-Emmett-Teller (BET) measurements. The g-value of 2.276 has confirmed the presence of the surface superoxide species of CeO2 nanoparticles in EPR. The photocatalytic activity of the catalyst and the membrane containing the catalyst was evaluated through the degradation of methylene blue under visible light irradiation by UV-VIS measurements. The cellulose/CeO2 membrane degraded 80% of the methylene blue solution in 120 minutes, showing a better photocatalytic activity than the CeO2 catalyst, which degraded approximately 62% in the same period. It has been proven that the RC membrane is not only a good transparent supporting material but also a good adsorption for high-performance of CeO2 catalyst. Copyright © 2022 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

Assessing forest cover changes in Dak Lak province (Central Highlands of Vietnam) from multi-temporal Landsat data and machine learning techniques

Dak Lak is a province in the Central Highlands region of Vietnam, with a large area of forests and forestry land. However, the forest cover has changed dramatically in recent times due to the influence of human activities and climate change. This article presents the results of assessing forest cover changes in Dak Lak province from Landsat satellite image data for the period 2000 – 2020. Three Landsat satellite image scenes, including Landsat 5 TM images taken in March 2000 and February 2010 and Landsat 8 OLI image taken in February 2020 are used to classify forest cover. Three common machine learning techniques, including Random Forest (RF), Support Vector Machine (SVM), Classification and Regression Tree (CART) and the traditional maximum likelihood classification algorithm are used to classify forest cover in the study area, thereby choosing the method with the highest accuracy. The results show that the RF algorithm has the highest accuracy in classifying forest cover from multi-temporal Landsat images by comparing the overall accuracy value and the Kappa coefficient. The obtained results are used to build forest cover change maps in the period 2000 - 2010, 2010 - 2020 and 2000 - 2020. The results received in the study provide information to help managers in monitoring and protecting forest resources