High-throughput Calculation of Atomic Planar Density for Compounds

A large collection of element-wise planar densities for compounds obtained from the Materials Project is calculated using brute force computational geometry methods. We demonstrate that the element-wise max lattice plane densities can be useful as machine learning features. The methods described here are implemented in an open-source Mathematica package hosted at https://github.com/sgbaird/LatticePlane.

Polarity Determination in EBSD Patterns Using the Hough Transformation

Currently, the automated electron backscatter diffraction (EBSD) technique only allows the differentiation of the Laue groups based on an electron backscatter pattern (EBSP). This article shows that information concerning the lattice plane polarity is not only stored in the EBSP, but also in the Hough transformed EBSP where it can be easily accessed for automated evaluation. Polar Kikuchi bands lead to asymmetric peaks during the Hough transformation that are dependent on the atomic number difference of the involved atoms. The effect can be strong enough to be detected when evaluating the intensities of the regular excess and deficiency lines. Polarity detection from the Hough transformation of an EBSP cannot only enhance the utility of the EBSD technique and expand the information gained from it, but also illustrates a path toward automated polarity determination during EBSD scans.

Optimized Synthesis Routes of MnOx-ZrO2 Hybrid Catalysts for Improved Toluene Combustion

In this contribution, the three Mn-Zr catalysts with MnxZr1−xO2 hybrid phase were synthesized by two-step precipitation route (TP), conventional coprecipitation method (CP) and ball milling process (MP). The components, textural and redox properties of the Mn-Zr hybrid catalysts were studied via XRD, BET, XPS, HR-TEM, H2-TPR. Regarding the variation of synthesis routes, the TP and CP routes offer a more obvious advantage in the adjustment of the concentration of MnxZr1−xO2 solid solution compared to the MP process, which directly commands the content of Mn4+ and oxygen vacancy and lattice oxygen, and thereby leads to the enhanced mobility of reactive oxygen species and catalytic activity for toluene combustion. Moreover, the TP-Mn2Zr3 catalyst with the enriched exposure content of 51.4% for the defective (111) lattice plane of MnxZr1−xO2 exhibited higher catalytic activity and thermal stability for toluene oxidation than that of the CP-Mn2Zr3 sample with a value of 49.3%. This new observation will provide a new perspective on the design of bimetal catalysts with a higher VOCs combustion abatement.

Using biochar from spent coffee grounds to treat pollution in livestock wastewater

Four types of biochar material synthesized from spent coffee grounds by slow pyrolysis process CF1 (500(C/0.5h); CF2 (500(C/1.5h); CF3 (500(C/3h); CF4 (500(C/6h) is studied to treat two pollution parameters (COD and TSS) in livestock wastewater. Material characteristics were determined by SEM, EDX and BET methods. The results showed that the 4 samples of biochar materials were structured fiber clearly, the interplanar spacing which corresponds to the lattice plane. The C content in the biochar sample is higher than the initial raw material sample; the highest value recorded reaches 90.61% C (CF2). 100 mL of the original livestock waster water is filtered through columns with 4g of biochar CF1-CF4 during reaction times varied from 0h, 1h, 4h and 8h, the COD treatment efficiency and adsorption content of CF4 sample is highest of 96.41% and 188 mg/g after 8h, and the lowest value is 76.67% and 149.5 mg/g after 1h recorded in CF3 sample, however the COD value after treatment is still higher from 1.2 to 1.46 times than Vietnamese standard 62: 2016/MONRE - national technical regulation on the effluent of livestock. The CF3 material samples have the highest TSS treatment efficiency and adsorption content of 95.19% and 6.425 mg/g after 8h and the lowest of 66.78% and 4.575 mg/g recorded in CF1 samples after 1h, response the requirements of QCVN 62: 2016/MONRE. The results showed that biochar is a potential sorbent to removed pollutants from waste water.

Algorithms for target transformations of lattice basis vectors

Simple algorithms are proposed for the transformation of lattice basis vectors to a specific target. In the first case, one of the new basis vectors is aligned to a predefined lattice direction, while in the second case, two of the new basis vectors are brought to a lattice plane with predefined Miller indices. The multi-dimensional generalization of the algorithm is available in the supporting materials. The algorithms are useful for such crystallographic operations as simulation of zone planes (i.e. geometry of electron diffraction patterns) or transformation of a unit cell for surface or cleavage energy calculations. The most general multi-dimensional version of the algorithm may be useful for the analysis of quasiperiodic crystals or as an alternative method of calculating Bézout coefficients. The algorithms are demonstrated both graphically and numerically.