ARTICLE | doi:10.20944/preprints202207.0265.v1
Subject: Environmental And Earth Sciences, Remote Sensing Keywords: GOES-R; GRU; Deep Learning; Wildfires; Active Fires; Early Detection; Monitoring
Online: 18 July 2022 (10:28:06 CEST)
Early detection of wildfires has been limited using the sun-synchronous orbit satellites due to their low temporal resolution and wildfires’ fast spread in the early stage. NOAA’s geostationary weather satellites GOES-R can acquire images every 15 minutes at 2km spatial resolution, and have been used for early fire detection. However, advanced processing algorithms are needed to provide timely and reliable detection of wildfires. In this research, a deep learning framework, based on Gated Recurrent Units (GRU), is proposed to detect wildfires at early stage using GOES-R dense time series data. GRU model maintains good performance on temporal modelling while keep a simple architecture, makes it suitable to efficiently process time-series data. 36 different wildfires in North and South America under the coverage of GOES-R satellites are selected to assess the effectiveness of the GRU method. The detection times based on GOES-R are compared with VIIRS active fire products at 375m resolution in NASA’s Fire Information for Resource Management System (FIRMS). The results show that GRU-based GOES-R detections of the wildfires are earlier than that of the VIIRS active fire products in most of the study areas. Also, results from proposed method offer more precise location on the active fire at early stage than GOES-R Active Fire Product in mid-latitude and low-latitude regions.
ARTICLE | doi:10.20944/preprints202308.1304.v1
Subject: Engineering, Chemical Engineering Keywords: Cationic polyacrylamide; flocculant; suspension; oilfield wastewater
Online: 18 August 2023 (08:32:22 CEST)
Solid particle cationic polyacrylamide (CPAM) is one of the most commonly used organic polymer flocculants in oilfield wastewater treatment, but there are some problems, such as slow dissolution rate, and easy to form a "fish-eye" in the process of diluting into aqueous solution. However, the current liquid CPAM products also have some problems, such as low effective content, poor storage stability, degradation in a short time and high preparation cost. In this paper, a secondary processing technology of solid particle CPAM was studied, and a CPAM suspension was successfully prepared. This suspension has an effective content of 50.00%, No separation in 7 days of storage at room temperature, no separation in 30 min of centrifugation at a speed of 2000 r/min, and diluted to a 0.40 % weak gel solution in just 16.00 min. For 1000 NTU of diatomite simulated wastewater, the optimal turbidity removal rate of the suspension was 99.50%, which was higher than the optimal turbidity removal rate of 98.40% for the inorganic flocculant polymeric aluminum chloride (PAC). For oil and gas field oily wastewater, the optimal turbidity removal rate of CPAM suspension was 35.60%, which was higher than the optimal turbidity removal rate of 28.40% for solid particle CPAM.
ARTICLE | doi:10.20944/preprints202008.0232.v1
Subject: Biology And Life Sciences, Agricultural Science And Agronomy Keywords: Brassica yellows virus (BrYV); Myzus persicae; transgenic plants with BrYV full length genome; frozen BrYV infected plants; acquisition and transmission
Online: 10 August 2020 (03:34:00 CEST)
Brassica yellows virus (BrYV) is a tentative species of the genus Polerovirus, which occurs widely and mostly damage Brassicaceae plants in East Asia. Since BrYV could not be transmitted mechanically, an insect transmission method is required for further virus research. Here, a reliable and unrestricted method was described, in which non-viruliferous aphids (Myzus persicae) acquired BrYV from transgenic Arabidopsis thaliana plants with virus full length genome germinated from seeds and frozen infected leaves were used to transmit the virus to healthy plants, and there was no significant difference in acquisition rate though transmission rate from frozen infected leaves was somehow lower compared to fresh infected leaves. This novel simple method could be applied to preservation of virus inocula, evaluation of variety resistance to BrYV, biological research on interaction among BrYV, aphid and host, which also provide a new idea on establishing a basic method using virus genomic transgenic plants or frozen infected leaves for other poleroviruses research.