Development of PSO for tracking Maximum Power Point of Photovoltaic Systems

For a photovoltaic system, the relationship of the output voltage and power is usually non-linear, so it is essential to equip a MPPT controller in PV systems. Furthermore, the hotspot problem is a common phenomenon, resulting from the PV system operating under PSC. Partial shading not only damages the PV cells, but also makes it difficult to find the global MPP in the characteristic curves of P-V. The paper proposes a novel version of PSO, namely PPSO in order to detect the global peak among the multiple peaks, known as the true maximum energy from PV panel. For this, the PPSO algorithm makes the velocity of each particle be perturbed once the particles are struck into a local minima state in order to find the best optimum solution in the MPPT problem. The perturbation in the velocity vector of each particle not only helps them tracking the MPP accurately under the changing environmental conditions, such as large fluctuations of insolation and temperature like PSC; but also removes the steady-state oscillation. The proposed approach has been tested on a MPPT system, which controls a dc-dc boost converter connected in series with a resistive load. Moreover, the obtained results are compared to those obtained without any MPPT controller to prove the efficiency of the suggested method. In addition, this novel version gives the highest accuracy of tracking the optimum power in the least iteration number as compared to the conventional PSO

Using Online Games in Teaching: A Bibliometric Analysis

This paper aims to study an overview of the using online games in teaching based on the Scopus data source from January 2016 to July 2023. The PRISMA model is used to guide the selection of articles. After selection and consideration, 19 scientific articles were included for analysis. The author analyzes information such as number of research articles, country, author, citations, keywords. The results showed that the number of research articles on the use of online games in teaching is increasing, in which the article “Using online game-based platforms to improve student performance and engagement in histology teaching" of the authors Felszeghy S. et al. (2019) most influential with a citation index of 81. Student, learning, online, games are keywords that often appear in the articles analyzed. Therefore, through systematic review research to help educational researchers, teachers identify important information about the use of online games in teaching so that they can guide future studies

Impact of climate change on meteorological, hydrological and agricultural droughts in the Lower Mekong River Basin: a case study of the Srepok Basin, Vietnam

peer reviewedThe objective of this study is to assess future changes in meteorological, hydrology and agricultural droughts under the impact of changing climate in the Srepok River Basin, a subbasin of LMB, using three drought indices; standardized precipitation index (SPI), standardized runoff index (SRI) and standardized soil moisture index (SSWI). The well-calibrated Soil and Water Assessment Tool (SWAT) is used as a simulation tool to estimate the features of meteorological, hydrological and agricultural droughts. The climate data for the 2016–2040 period is obtained from four different regional climate models; HadGEM3-RA, SNU-MM5, RegCM4 and YSU-RSM, which are downscaled from the HadGEM2-AO GCM. The results show that the severity, duration and frequency of droughts are predicted to increase in the near future for this region. Moreover, the meteorological drought is less sensitive to climate change than the hydrological and agricultural droughts; however, it has a stronger correlation with the hydrological and agricultural droughts as the accumulation period is increased. These findings may be useful for water resources management and future planning for mitigation and adaptation to the climate change impact in the Srepok River Basin

Functional-Antioxidant Food

Nowadays, people face many different dangers, such as stress, unsafety food, and environmental pollution, but not everyone suffers. Meanwhile, free radicals are the biggest threat for humans because they lead to over 80 different diseases composed of aging. Free radicals can only be eliminated or minimized with antioxidant foods or antioxidants. The chapter on the functional-antioxidant food presents the antioxidant functional food concept, the classification, the structure, and the extraction process of antioxidant ingredients. Various antioxidant substances such as protein (collagen), polysaccharides (fucoidans, alginates, glucosamines, inulins, laminarins, ulvans, and pectins), and secondary metabolites (polyphenols (phlorotannins, lignins, polyphenols), alkaloids, and flavonoids) also present. The production technology, the mechanism, the opportunity, and the challenge of antioxidants functional food also present in the current chapter. The current chapter also gives the production process of functional-antioxidant food composed of the capsule, the tablet, tube, the pills, the powder, and the effervescent tablet

CSA: Thực hành nông nghiệp thông minh với khí hậu ở Việt Nam

During the last five years, Vietnam has been one of the countries most affected by climate change. Severe typhoons, flooding, cold spells, salinity intrusion, and drought have affected agriculture production across the country, from upland to lowland regions. Fortunately for Vietnam, continuous work in developing climate-smart agriculture has been occurring in research organizations and among innovative farmers and entrepreneurs. Application of various CSA practices and technologies to adapt to the impact of climate change in agriculture production have been expanding. However, there is a need to accelerate the scaling process of these practices and technologies in order to ensure growth of agriculture production and food security, increase income of farmers, make farming climate resilient, and contribute to global climate change mitigation. This book aims to provide basic information to researchers, managers, and technicians and extentionists at different levels on what CSA practices and technologies can be up scaled in different locations in Vietnam

ĐẶC ĐIỂM DÒNG CHẢY VEN BỜ BẮC TRUNG BỘ (HÀ TĨNH - THỪA THIÊN-HUẾ) THỜI KỲ 4/2016

This paper presents the modeled results of general current pattern (daily average value) in Northern Central Vietnam Coast (Ha Tinh - Thua Thien-Hue) during April 2016. Study results show that in general, current flowed from the North to the South with small and instable velocity (V ≈ 0.1 - 0.2 m/s). From 2nd to 6th April current flowed from the South to the North. From 7th to 29th April current flowed from the North to the South. During 13rd to 16th April current velocity was weak (V ≤ 0.1 m/s). In the southern region of Thua Thien-Hue province, the direction of current was instable (from 6th to 9th and from 20th to 22nd April current flowed from the South to the North). Current distribution pattern from modeled results was in accordance with the propagation characteristics of surface water temperatures in the studied area through data analysis of satellite images.Bài báo trình bày kết quả tính toán trường dòng chảy tổng hợp trung bình ngày cho khu vực ven bờ Bắc Trung Bộ (Hà Tĩnh - Thừa Thiên-Huế) thời kỳ 4/2016. Kết quả nghiên cứu cho thấy trong thời gian nghiên cứu nhìn chung dòng chảy tổng hợp trung bình ngày có hướng từ bắc xuống nam, tốc độ tương đối nhỏ V ≈ 0,1 - 0,2 m/s và không ổn định. Từ 2-6/4/2016 dòng chảy tổng hợp trung bình ngày ven bờ có hướng từ nam lên bắc. Từ 7-29/4/2016 dòng chảy ven bờ có hướng từ bắc xuống nam. Các ngày 13-16/4/2016 dòng chảy tổng hợp trung bình ngày có tốc độ nhỏ (V ≤ 0,1 m/s). Khu vực phía nam Thừa Thiên-Huế dòng chảy tổng hợp trung bình ngày có hướng bị biến động mạnh nhất (các ngày 6-9/4 và 20-22/4 hướng dòng từ nam lên bắc). Đặc điểm phân bố dòng chảy tính toán tương đối phù hợp với đặc điểm lan truyền nhiệt độ nước tầng mặt tại khu vực nghiên cứu qua số liệu phân tích ảnh vệ tinh

An Update on Anti-CD137 Antibodies in Immunotherapies for Cancer

The selective expression of CD137 on cells of the immune system (e.g., T and DC cells) and oncogenic cells in several types of cancer leads this molecule to be an attractive target to discover cancer immunotherapy. Therefore, specific antibodies against CD137 are being studied and developed aiming to activate and enhance anti-cancer immune responses as well as suppress oncogenic cells. Accumulating evidence suggests that anti-CD137 antibodies can be used separately to prevent tumor in some cases, while in other cases, these antibodies need to be co-administered with other antibodies or drugs/vaccines/regents for a better performance. Thus, in this work, we aim to update and discuss current knowledge about anti-cancer effects of anti-CD137 antibodies as mono- and combined-immunotherapies

Repeated local emergence of carbapenem-resistant Acinetobacter baumannii in a single hospital ward.

We recently reported a dramatic increase in the prevalence of carbapenem-resistant Acinetobacter baumannii infections in the intensive care unit (ICU) of a Vietnamese hospital. This upsurge was associated with a specific oxa23-positive clone that was identified by multilocus VNTR analysis. Here, we used whole-genome sequence analysis to dissect the emergence of carbapenem-resistant A. baumannii causing ventilator-associated pneumonia (VAP) in the ICU during 2009-2012. To provide historical context and distinguish microevolution from strain introduction, we compared these genomes with those of A. baumannii asymptomatic carriage and VAP isolates from this same ICU collected during 2003-2007. We identified diverse lineages co-circulating over many years. Carbapenem resistance was associated with the presence of oxa23, oxa40, oxa58 and ndm1 genes in multiple lineages. The majority of resistant isolates were oxa23-positive global clone GC2; fine-scale phylogenomic analysis revealed five distinct GC2 sublineages within the ICU that had evolved locally via independent chromosomal insertions of oxa23 transposons. The increase in infections caused by carbapenem-resistant A. baumannii was associated with transposon-mediated transmission of a carbapenemase gene, rather than clonal expansion or spread of a carbapenemase-harbouring plasmid. Additionally, we found evidence of homologous recombination creating diversity within the local GC2 population, including several events resulting in replacement of the capsule locus. We identified likely donors of the imported capsule locus sequences amongst the A. baumannii isolated on the same ward, suggesting that diversification was largely facilitated via reassortment and sharing of genetic material within the localized A. baumannii population

Dry reforming of methane over calcium-deficient hydroxyapatite supported cobalt and nickel catalysts

National audienceCalcium-deficient hydroxyapatite (HAP) non-porous supports were synthesized from Ca(NO3)2 and NH4H2PO4 (conventional synthesis route, HAP_N support) and from CaCO3 and H3PO4 (new synthesis route, HAP_C support) by wet chemical precipitation method. Monometallic and bimetallic supported catalysts were prepared by incipient wetness impregnation using Co(NO3)2 and Ni(NO3)2 salts. The size of Co- and Ni-based particles varied from some nm to dozens nm. Dry reforming of methane (DRM) tests at 700 °C, and 1.6 bar shows that HAP-supported cobalt catalysts were systematically more active than HAP-supported nickel catalysts, which is a new finding in DRM. Increasing the molar ratio of Ca/P from 1.43 (HAP_N) to 1.60 (HAP_C) support led to a slight decrease of the catalytic activity but an improvement of the catalytic stability. Thus, HAP_C support synthesized from CaCO3 and H3PO4 is a good candidate for designing an efficient catalyst for the DRM reaction