Controllable Preparation of Cubic Zeolite A and Application of Langmuir Model in Carbon Dioxide Adsorption

A large amount of remaining fly ash has been piled up or landfilled, which not only a waste of land resources but also results in a series of environmental problems. Therefore, using fly ash to produce high value-added products is a win-win development orientation between human beings and nature. In this study, zeolite A is successfully synthesized using a hydrothermal method using fly ash. Additionally, it is at 1.0 mol·L−1 of the alkali concentration that the crystallinity of zeolite A reaches the maximum value, about 96.6%. FTIR research shows that the main secondary structural unit D4R vibration band of zeolite A appears at 555 cm−1. The results of the SEM study indicate the structure of zeolite A is cubic. The TEM results show that the crystal structure of the zeolite A belongs to the body-centered cubic structure. Meanwhile, the positively charged sodium ions cooperate with the silicon oxygen tetrahedron and the aluminum oxygen tetrahedron to form the zeolite A skeleton. Carbon dioxide adsorption equilibrium study shows that the maximum adsorption capacity of zeolite A of 46.5 mL·g−1 is significantly higher than the maximum adsorption capacity of commercial-grade zeolite 4A of 39.3 mL·g−1. In addition, the application of the Langmuir model in the adsorption of carbon dioxide by commercial-grade zeolite 4A and zeolite A is studied, which not only extends the application of zeolite A, but can be further extended to other zeolite materials as well. Meanwhile, the adsorption process belongs to the Langmuir model, which is a single layer adsorption on an ideal surface.

Phosphogypsum-Paraffin Composites for Low Temperature Thermal Energy Storage Applications

Phoshpogypsum (PG) is an environmentally hazardous industrial by-product of the fertilizer industry with an annual production of 300 Mt, with a utilization rate of only 15%. In this work, we propose a novel use-case for PG. The latter is combined with a commercial-grade paraffin to fabricate composite phase change materials (CPCMs), for thermal energy storage applications. CPCMs are fabricated following a comminution and sintering process. The fabricated materials exhibit a stable latent heat (75 J/g) after 96 cycles (25 to 100 °C), with a maximum average specific heat capacity of 1.54 J/gK at 60% paraffin content. The thermal conductivity is found to be 75% higher than pure paraffin, while the energy storage density is only 14% lower.

Detecting Excessive Daytime Sleepiness With CNN And Commercial Grade EEG

Epworth sleepiness scale is a self-assessment method in sleep medicine that has been proven to be a good predictor of obstructive sleep apnea. However, the over-reliance of the method making the process not socially distancing friendly enough in response to a global covid-19 pandemic. A study states that the Epworth sleepiness scale is correlated with the brainwave signal that commercial-grade EEG can capture. This study tried to train a classifier powered by CNN and deep learning that could perform as well as the Epworth with the objectiveness of brainwave signal. We test the classifier using the 20 university student using the Epworth sleepiness test beforehand. Then, we put the participant in 10 minutes EEG session, downsampling the data for normalization purposes and trying to predict the outcome of the ESS in respect of their brainwave state. The AI predict the reaching 65% of accuracy and 81% of sensitivity with just under 100.000 dataset which is excellent considering small dataset although this still have plenty room for improvement.

Simulation of RSO Images for Space Situation Awareness (SSA) Using Parallel Processing

With the rapid increase in resident space objects (RSO), there is a growing demand for their identification and characterization to advance space simulation awareness (SSA) programs. Various AI-based technologies are proposed and demonstrated around the world to effectively and efficiently identify RSOs from ground and space-based observations; however, there remains a challenge in AI training due to the lack of labeled datasets for accurate RSO detection. In this paper, we present an overview of the starfield simulator to generate a realistic representation of images from space-borne imagers. In particular, we focus on low-resolution images such as those taken with a commercial-grade star tracker that contains various RSO in starfield images. The accuracy and computational efficiency of the simulator are compared to the commercial simulator, namely STK-EOIR to demonstrate the performance of the simulator. In comparing over 1000 images from the Fast Auroral Imager (FAI) onboard CASSIOPE satellite, the current simulator generates both stars and RSOs with approximately the same accuracy (compared to the real images) as STK-EOIR and, an order of magnitude faster in computational speed by leveraging parallel processing methodologies.

Effects of Curing on Photosensitive Resins in SLA Additive Manufacturing

Different mechanical properties characterise the materials of 3D printed components, depending on the specific additive manufacturing (AM) process, its parameters, and the post-treatment adopted. Specifically, stereolithography (SLA) uses a photopolymerisation technique that creates solid components through selective solidification. In this study, 72 specimens were 3D printed using 12 commercial-grade methacrylate resins and tested under uniaxial tensile loads. The resin specimens were evaluated before and after curing. The recommended cure temperature and time were followed for all materials. The stress-strain curves measured during the testing campaign were evaluated in terms of maximum tensile strength, Young’s modulus, ductility, resilience, and toughness. The results reveal that the curing process increases the material stiffness and resistance to tensile loads. However, it was found that the curing process generally reduces the plasticity of the resins, causing a more or less marked brittle behaviour. This represents a potential limitation to the use of SLA 3D printing for structural elements which require some plasticity to avoid dangerous sudden failures.

Toward nanotechnology-enabled face masks against SARS-CoV-2 and pandemic respiratory diseases

Wearing a face mask has become a necessity following the outbreak of the coronavirus (COVID-19) disease, where its effectiveness in containing the pandemic has been confirmed. Nevertheless, the pandemic has revealed major deficiencies in the ability to manufacture and ramp up worldwide production of efficient surgical-grade face masks. As a result, many researchers have focused their efforts on the development of low cost, smart and effective face covers. In this article, following a short introduction concerning face mask requirements, the different nanotechnology-enabled techniques for achieving better protection against the SARS-CoV-2 virus are reviewed, including the development of nanoporous and nanofibrous membranes in addition to triboelectric nanogenerators based masks, which can filter the virus using various mechanisms such as straining, electrostatic attraction and electrocution. The development of nanomaterials-based mask coatings to achieve virus repellent and sterilizing capabilities, including antiviral, hydrophobic and photothermal features are also discussed. Finally, the usability of nanotechnology-enabled face masks is discussed and compared with that of current commercial-grade N95 masks. To conclude, we highlight the challenges associated with the quick transfer of nanomaterials-enabled face masks and provide an overall outlook of the importance of nanotechnology in counteracting the COVID-19 and future pandemics.

The Effect of Nitrogen Linear Flow on Lubricant Removal and Sintering Densification of Alumix 431D Grade Powder

ECKA Granules Alumix 431D commercial grade, press ready, pre-alloyed aluminium-based powder containing 1.5 mass% of Acrawax C was used to study the effect of nitrogen linear flow on de-lubrication and sintering densification. In situ dimensional changes were controlled by dilatometry. Microstructural observations of sintered compacts were also performed. The results clearly showed the strong influence of nitrogen linear flow on de-lubrication, and thus on the sintering behaviour of the examined powder. High nitrogen linear flow is required to produce the desired sintered microstructure—characterised by residual porosity. In contrast, at low nitrogen velocity, the lubricant removal is not complete, which in turn significantly impedes densification.

Influence of seed invigouration and foliar spray on seed yield of semi dry rice

A study was conducted in Soil and Water Management Research Institute, Thanjavur with different combination of seed treatments and foliar spray on growth parameters of rice and its seed yield. Paddy variety Anna (R) 4 seeds were invigourated with different seed treating chemical/biocontroll agents viz., 1% Potassium Chloride, 750 PPM Gelatin (commercial grade), 2% Pigmented Facultative Methylotroph (PPFM) for 12 hours soaking and dried back to original moisture content of 13%. The seeds were dibbled with a spacing of 20 x 10 cm and other recommended package of practice was followed to all the plots. Foliar nutrition on 60 and 90 days after sowing was done with 2% DAP, 4 % cowpea sprout extract and 4 % horsegram sprout extract were applied. Seeds hardened with 2% Pink Pigmented Facultative Methylotroph (PPFM) for 12 hrs and foliar spray with 4 % cowpea sprout extract on 60 and 90 days after sowing recorded significant enhancement in productive tillers, seeds /panicle, 1000 seed weight and 11 per cent higher seed yield than the control.