LC-decomposability and the AR-properly in linear metric spaces

departmental bulletin pape

Corrosion protection of carbon steel by an epoxy resin containing organically modified clay

This study focusses on the use of montmorillonite clay (MMT) treated with an organic compound (aminotrimethylphosphonic acid (ATMP)) and dispersed in an epoxy resin to improve corrosion protection of carbon steel. X-ray diffraction was performed to verify that the individual silicate layers were separated and dispersed in the epoxy resin. Corrosion resistance of the coated steel was evaluated by electrochemical impedance spectroscopy (EIS) and local electrochemical impedance spectroscopy (LEIS). Three systems were tested: the epoxy clear-coat, the epoxy resin containing 2 wt.% clay and the epoxy resin containing 2 wt.% clay modified byATMP (ATMP-modified clay). From conventional EIS, it was shown that the incorporation of clay or ATMP-modified clay in the epoxy matrix significantly improved the barrier properties of the coating. The corrosion resistance of the carbon steel coated by the epoxy resin containing ATMP-modified clay was higher than that obtained for the system containing non-treated clay. Local electrochemical measurements performed on scratched samples revealed the inhibitive role of ATMP at the carbon steel/coating interface

Incorporation of an indole-3 butyric acid modified clay in epoxy resin for corrosion protection of carbon steel

In the present work, indole-3 butyric acid (IBA) was inserted between montmorillonite clay platelets by cation exchange. The clay treated with the organic compound (IBA-modified clay) was then dispersed in an epoxy resin at a low concentration (2 wt.%). IBA was chosen to act both as an inhibitor and an adherence promoter. The effect of the IBA-modified clay on the microstructure and on the protective properties of the epoxy coating deposited on carbon steel was evaluated by a thermostimulated-current (TSC) method and by electrochemical impedance spectroscopy (EIS). The TSC measurements showed the specific action of IBA-modified clay which decreased the molecular mobility of the polymer chain by comparison with the pure epoxy. Impedance measurements corroborated the role of the modified clay on the barrier properties of the coating which remained high as a function of exposure time in a 0.5 M NaCl solution. The corrosion resistance of the carbon steel coated with the epoxy resin containing IBA-modified clay was significantly higher than that obtained with the clear coat. Polarization curves plotted in the presence of an artificial defect demonstrated the inhibitive role of IBA at the carbon steel/coating interface. The good adherence of the coating was seen during salt spray test

FATTY ACID COMPOSITION AND ANTIOXIDANT ACTIVITY OF CAMELLIA NINHII SEED OIL COLLECTED IN LAM DONG PROVINCE

The seed oil of Camellia ninhii was studied for the first time on its fatty acid composition by gas chromatography-mass spectrometry (GC-MS) and antioxidant activity by the DPPH method. The results show that unsaturated fatty acids account for the largest amount, especially oleic acid with 45.43% of the total sample analyzed. In addition, other fatty acids, palmitic, linoleic, pentadecanoic, and two aromatic acids, benzoic and cinnamic, were present. The sample of C. ninhii seed oil exhibited mild antioxidant activity against DPPH free radicals with IC50 = 0.94 mg/mL

ISOLATION AND STRUCTURAL IDENTIFICATION OF TRITERPENE COMPOUNDS FROM THE LEAVES OF RUBUS ANNAMENSIS CARDOT COLLECTED IN LAM DONG PROVINCE

From the leaves of Rubus annamensis Cardot collected in Lam Dong Province, two triterpene compounds were isolated and identified as niga-ichigoside F1 (2α,3β,19α,23-tetrahydroxy-urs-12-en-28-oic acid-β-D-glucopyranosyl ester) and ursolic acid (3-beta-3-hydroxy-urs-12-ene-28-oic acid) by using chromatographic and spectroscopic methods (IR, 1H-NMR, 13C-NMR, DEPT, HSQC, HMBC, and ESI-MS). This is the first time these compounds have been isolated from Rubus annamensis

Performance of the CMS Cathode Strip Chambers with Cosmic Rays

The Cathode Strip Chambers (CSCs) constitute the primary muon tracking device in the CMS endcaps. Their performance has been evaluated using data taken during a cosmic ray run in fall 2008. Measured noise levels are low, with the number of noisy channels well below 1%. Coordinate resolution was measured for all types of chambers, and fall in the range 47 microns to 243 microns. The efficiencies for local charged track triggers, for hit and for segments reconstruction were measured, and are above 99%. The timing resolution per layer is approximately 5 ns

Layered double hydroxides as containers of inhibitors in organic coatings for corrosion protection of carbon steel

The present work focuses on the use of layered double hydroxides (LDH) as containers for corrosion inhibitors in an epoxy coating. 2-Benzothiazolylthio-succinic acid (BTSA), used as corrosion inhibitor, was intercalated by co-precipitation in magnesium-aluminum layered double hydroxides. The obtained LDH-BTSA was characterized by infrared spectroscopy, X-ray diffraction and scanning electron microscopy. BTSA release from LDH-BTSA in NaCl solutions was investigated by UV-vis spectroscopy. The inhibitive action of LDH-BTSA on carbon steel corrosion was characterized by electrochemical methods and the protective properties of an epoxy coating containing LDH-BTSA were evaluated by electrochemical impedance spectroscopy. It was shown that the BTSA was intercalated in the layered double hydroxide and its loading was about 33%. The BTSA release was dependent on the NaCl concentration in the electrolyte. The polarization curves obtained on the carbon steel sample showed that the LDH-BTSA is an anodic inhibitor. Its efficiency was about 90% at a concentration of 3 g/l. The impedance results showed that the incorporation of LDH-BTSA (3%) in the epoxy matrix improved the corrosion protection of the carbon steel

Para-Social Interaction and Trust in Live-Streaming Sellers

Live streaming is one of the modern methods that allows sellers to create, transmit, or broadcast some content on the internet in real-time, and it has been used by many small individual merchants. Understanding how live streaming contributes to online consumption is becoming increasingly important in social commerce as the live-streaming industry has grown more and more popular. However, the number of studies on live streaming is still quite limited in Vietnam. Therefore, this research will look at the mechanism that enables live streaming to boost customer trust in streamers. Using PLS-SEM on a sample of 360 respondents who viewed selling live streams on social network sites in Vietnam, we discovered that other members' endorsement, value similarity, hedonic value, and utilitarian value contribute to good para-social interaction. Next, utilitarian and hedonic values, streamer product expertise, and para-social interaction all positively affect trust in the streamers. The findings could help live-streaming sellers better understand their social interactions with viewers, resulting in increased customer trust. Doi: 10.28991/ESJ-2023-07-03-06 Full Text: PD

Monitoring of coastline change using Sentinel-2 MSI data. A case study in Thanh Hoa Province, Vietnam

Vietnam is a coastal country with a coastline of more than 3,260 km, stretching from north to south. Coastal change in Vietnam is complicated further by the effects of climate change, including erosion and accretion, causing great impacts on infrastructure and the environment. This article presents the results of assessing coastline changes in Thanh Hoa Province (North Central region of Vietnam) from Sentinel-2 MSI satellite image data for the period 2015–23. Three Sentinel-2 MSI images taken in December 2015, December 2020 and December 2023 were used to calculate the water indices, including Normalised Difference Water Index (NDWI), Modified Normalised Difference Water Index (MNDWI) Argumented Normalised Difference Water Index (ANDWI) and Automated Water Extraction Index (AWEIsh), then extract the shoreline using the thresholding method and select the water index with the highest accuracy through comparing the overall accuracy and Kappa coefficient. The coastlines of 2015, 2020 and 2023 years are overlaid to evaluate the coastal changes in the study area. The results received in the study provide objective and timely information, helping managers effectively monitor and respond to coastline changes

FOMO (Fear Of Missing Out) and social media influencers: Exploring their impact on impulsive buying behavior among young TikTok users in Tra Vinh City

The rapid evolution of social media platforms, particularly TikTok, has transformed consumer behavior, driving impulsive purchasing trends among young users. TikTok Shop’s innovative “shoppertainment” model seamlessly blends entertainment with shopping, fostering unplanned purchases. This study integrates the Theory of Planned Behavior (TPB), the Technology Acceptance Model (TAM), and the black box model of consumer behavior to provide a comprehensive understanding of the factors influencing impulsive buying behavior among young people in Tra Vinh City. By focusing on Fear Of Missing Out (FOMO), social media influencers, perceived enjoyment, trust, price, and discounts, and impulsiveness, the study reveals significant psychological and environmental drivers of consumer behavior in social commerce. Based on 320 valid responses, Structural Equation Modeling (SEM) reveals that FOMO and influencers enhance perceived enjoyment by 21.7% and 17.7%, respectively, significantly contributing to impulsive buying behavior. The urgency to avoid missing out and the credibility of influencers create engaging shopping experiences that encourage spontaneous purchases. Additionally, price and discounts positively impact impulsive buying, while trust strengthens consumer confidence. These insights suggest that businesses on TikTok Shop can boost customer engagement and drive sales by implementing FOMO-driven campaigns, partnering with credible influencers, and maintaining transparency in product information and customer support