Fabrication of a Nanosize Hematite Pigment via Waste Ferrous Sulfate Recycling Using Sulfur Reduction

Nanometer-sized hematite was prepared via a two-step process. In the first step, FeSO₄·7H₂O was oxidized to Fe₂(SO₄)₃ by oxygen in an acidic solution. In the second step, the Fe₂(SO₄)₃ was reduced to nanosize hematite with sulfur vapor at 550 °C. The...

Classification of airborne laser scanning point cloud using point-based convolutional neural network

In various applications of airborne laser scanning (ALS), the classification of the point cloud is a basic and key step. It requires assigning category labels to each point, such as ground, building or vegetation. Convolutional neural networks have achieved great success in image classification and semantic segmentation, but they cannot be...