Strong green-emission phosphor Ca2SiO4:Eu2+ to achieve the color constancy and high luminous efficiency for white LEDs

The study uses the green phosphor of Ca2SiO4:Eu2+ to achieve the color constancy for the dual-film remote phosphor white-LED model at low as well as big CCTs. The utilized green phosphor Ca2SiO4:Eu2+ was prepared using the water-soluble-silicon liquid phase precursor method with the doped Eu2+ ion concentration of 3 mol%. The Ca2SiO4:Eu2+ phosphor emits strong green light with emission intensity focused at 502 nm wavelength, and a wide stimulation band of colors of 225 nm – 450 nm. After applying the Ca2SiO4:Eu2+ green phosphor and modifying its concentration, the modified color and luminous performances can be observed. The better color uniformity and higher luminescence efficiency can be obtained by increasing the percentage of Ca2SiO4:Eu2+ in the phosphor configuration. Meanwhile, the color rendering metrics tend to reduce slightly when the concentration of Ca2SiO4:Eu2+ is over 10% wt

A DOUBLE-SHRINK AUTOENCODER FOR NETWORK ANOMALY DETECTION

The rapid development of the Internet and the wide spread of its applications has affected many aspects of our life. However, this development also makes the cyberspace more vulnerable to various attacks. Thus, detecting and preventing these attacks are crucial for the next development of the Internet and its services. Recently, machine learning methods have been widely adopted in detecting network attacks. Among many machine learning methods, AutoEncoders (AEs) are known as the state-of-the-art techniques for network anomaly detection. Although, AEs have been successfully applied to detect many types of attacks, it is often unable to detect some difficult attacks that attempt to mimic the normal network traffic. In order to handle this issue, we propose a new model based on AutoEncoder called Double-Shrink AutoEncoder (DSAE). DSAE put more shrinkage on the normal data in the middle hidden layer. This helps to pull out some anomalies that are very similar to normal data. DSAE are evaluated on six well-known network attacks datasets. The experimental results show that our model performs competitively to the state-of-the-art model, and often out-performs this model on the attacks group that is difficult for the previous methods

Optimal Design of V-Shaped Fin Heat Sink for Active Antenna Unit of 5G Base Station

The active antenna unit (AAU) is one of the main parts of the 5G base station, which has a large size and a high density of chipsets, and operates at a significantly high temperature. This systematic study presents an optimal design for the heat sink of an AAU with a V-shaped fin arrangement. First, a simulation of the heat dissipation was conducted on two designs of the heat sink – in-line and V-shaped fins – which was validated by experimental results. The result shows that the heat sink with V-shaped fins performed better compared to conventional models such as heat sinks with in-line fins. Secondly, computational fluid dynamics (CFD) and the Lagrange interpolation method were applied to find out an optimal set of design parameters for the heat sink. It is worth noting that the optimal parameters of the orientation angle and fin spacing considerably affected the heat sink’s performance.  

Optimal Design of V-Shaped Fin Heat Sink for Active Antenna Unit of 5G Base Station

The active antenna unit (AAU) is one of the main parts of the 5G base station, which has a large size and a high density of chipsets, and operates at a significantly high temperature. This systematic study presents an optimal design for the heat sink of an AAU with a V-shaped fin arrangement. First, a simulation of the heat dissipation was conducted on two designs of the heat sink – in-line and V-shaped fins – which was validated by experimental results. The result shows that the heat sink with V-shaped fins performed better compared to conventional models such as heat sinks with in-line fins. Secondly, computational fluid dynamics (CFD) and the Lagrange interpolation method were applied to find out an optimal set of design parameters for the heat sink. It is worth noting that the optimal parameters of the orientation angle and fin spacing considerably affected the heat sink’s performance.  

Cyclization of some N-Arylidene-2-(Acetamido)-3-(4-Chlorophenyl)Acrylohydrazides to 1-Arylideneamino-4-(4-Chlorobenzylidene)-2-Methyl-1h-Imidazolin-5(4h)-Ones

Cyclization of the N-arylidene-2-(acetamido)-3-(4-chlorophenyl)acrylohydrazides, which were prepared from 4-chlorobenzaldehyde and acetylglycine via 4-chlorobenzylidene-2-methyl-(4H)-oxazol-5-one and then 2-(acetamido)-3-(4-chlorophenyl)acrylohydrazide, on treatment with acetic anhydride gave seven corresponding compounds namely 1-arylideneamino-4-(4-chlorobenzylidene)-2-methyl-1H-imidazolin-5(4H)-ones but did not give 3-acetyl-2-aryl-5-[1-acetamido-2-(4-chlorophenyl)vinyl]-1,3,4-oxadiazolines. The structure of the imidazoline-5-one compounds was confirmed by IR, 1H-NMR and MS spectral data

Recombinant protein expression of Magnaporthe oryzae MGG06069 and its polysaccharide monooxygenase domain in Escherichia coli

5 p.MGG06069 is a polysaccharide monooxygenase protein that originated from the fungus that causes rice blast, Magnaporthe oryzae. It has the potential to speed up the cellulolysis process, which can be beneficial for industry. In this study, the full-length MGG06069 protein and its polysaccharide monooxygenase domain were expressed in Escherichia coli in order to produce recombinant proteins on a large scale for further enzymatic experiment. It was shown that the amount of the recombinant polysaccharide monooxygenase domain protein was much higher compared to that of the full-length protein. In addition, only one band of expected size was obtained for the recombinant PMO domain protein. These results suggest the purified polysaccharide monooxygenase domain of MGG06069 that can be used for enzymatic assays in the future

Applied the Cokriging interpolation method to survey Air Quality Index (AQI) for dust TSP in Da Nang city

9 pages.Mapping to forecast the air pollution concentration in Da Nang city is an urgent issue for management agencies and researchers of environmental pollution. Although the simulation of spatial location has become popular, it uses the classical interpolation methods with low reliability. Based on the distribution of air quality monitoring stations located in industrial parks, residential areas, transport axes... and sources of air pollution, the application of geostatistical theories, this study presents the results of the Cokriging's interpolation selection which provides forecast results of air pollution distribution in Da Nang city with high reliability. In this article, we use the recorded TSP concentrations (one of major air pollution causes at large metropolis) at several observational stations in Da Nang city, employ the Cokriging interpolation method to find suitable models, then predict TSP dust concentrations at some unmeasured stations in the city. Our key contribution is finding good statistical models by several criteria, then fitting those models with high precision

CAMELLIA PAUCIPUNCTATA (THEACEAE), A NEW RECORD FOR THE FLORA OF VIETNAM

Camellia paucipunctata is described and illustrated as a new record for the flora of Vietnam. C. paucipunctata is a small tree with young branches glabrous; leaf blade elliptic to broadly elliptic or obovate, glabrous; secondary veins 6–7 pairs, obscurely serrulate, abaxially pale green and brown glandular punctate; flowers subsessile; sepals 4–(5), velutinous on the face; petals 5–6, broadly obovate, yellowish-white; stamens united at the base, inside velutinous; ovary 3–(4)-loculed; style 3–(4), free, 5–8 mm, glabrous; capsule subglobose to globose, 4.5–5.0 cm high, 3.0–4.0 cm wide, 3–(4)-loculed, pericarp thick, furfuraceous. The morphological evidence supports its placement in Camellia section Heterogenea

Study of Using Cassava Pulp to Produce Livestock Feed Pellet

In Vietnam, the cassava production capacity is about 10 million tons annually. Indeed, it eliminates approximate 4 million tons of cassava pulp from the cassava starch factories. This amount of cassava is usually dried to feed cattle or fertilizer. However, drying of cassava pulp has its disadvantages such as air pollution, difficult storage and transportation. This study has proposed and successfully tested a line of equipment used to produce pellets from the utilization of fresh cassava pulp bringing from cassava starch processing plants. The processing includes a mixing of fresh cassava pulp with dried cassava starch, pressing and drying of pellets. The experiment results show that when the mixing ratio between cassava starch and cassava residue is 1:10 – 1:5, the cassava pulp pellets after drying achieved the required technical specifications. Hence, it has high volume density, the dried specific weight of the pellets is about 700 kg / m3, the breaking strength of the pellets is greater than 2 kG, the tanning time of the pellets is greater than 116 minutes in water, the moisture content of the pellets is remained in 13% after drying in 5-5.5 hours

Investigation of factors affecting the green synthesis of silver nanoparticles from guava leaf extract

Green-synthesised silver nanoparticles offer substantial advantages for biomedical applications due to reduced chemical impacts, straightforward methods, and environmental friendliness. However, the outcome of nanoparticle synthesis is heavily influenced by reaction conditions, affecting their formation, size, and properties. It is therefore crucial to establish precise synthesis protocols and optimise conditions pertaining to reducing agents, silver salt concentration, and other influential factors. This study identifies optimal conditions for the green synthesis of silver nanoparticles using guava leaf extract. Various analytical techniques such as Ultraviolet-visible spectroscopy (UV-Vis), Dynamic light scattering (DLS), X-ray diffraction (XRD), Field-emission scanning electron microscopy (FE-SEM), Fourier-transform infrared spectroscopy (FT-IR), and Energy-dispersive X-ray spectroscopy (EDX) were employed to characterise the material properties. The synthesised silver nanoparticles exhibited absorption at 430 nm wavelength, demonstrated a face-centred cubic crystalline structure with high crystallinity, and showed an average particle size ranging from 30-40 nm, predominantly spherical and uniformly distributed. Flavonoids present in the guava leaf extract were identified as the primary compounds responsible for the reduction of silver ions. To minimise residual extract and enhance the applicability of silver nanomaterials, a washing and filtration process was implemented. A thorough investigation into influencing factors and the resolution of issues related to the green synthesis of silver nanoparticles can pave the way for future research and boost the commercial potential of green nanomaterial products for medical and environmental applications