Optimal instar and method of meta-tolyl-N-methyl-carbamate application for killing Aphrophora costalis Matsumura

BioResources ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. 8082-8097
Author(s):  
Yi Huang ◽  
Ze Huang ◽  
Junpeng Liu ◽  
Fei Wu ◽  
Qingde Li ◽  
...  
Keyword(s):  
Insect Pests ◽  
Gradual Increase ◽  
Practical Significance ◽  
Leaching Rate ◽  
Chromatography Method ◽  
Brown Soil ◽  
Soil Clay ◽  
The Impact ◽  
Layer Chromatography ◽  
Desorption Capacity

For determining the effects of meta-tolyl-N-methylcarbamate (MTMC, metolcarb) on Aphrophora costalis Matsumura (ACM) and the migration and leaching law of MTMC in soil, the thin-layer chromatography method was used. The characteristics of migration and leaching of MTMC in the dark brown soils, and the most critical influences such as soil type, pH, and amount of water were considered to evaluate the impact of leaching rate. The results showed that 25% MTMC diluted 1,000 times was most effective in controlling ACM, with a mortality reaching 87.8% by root irrigation, and a mortality of up to 94.4% by root burial. For dark brown soil, clay minerals are primarily quartz, as well as small amounts of agalmatolite, mica, and kaolinite. Adsorption of MTMC by dark brown soil begins within 2 h, which increases rapidly in capacity before 16 h, and tends to balance with a decrease in the gradient concentration after 16 h. The desorption capacity of MTMC exhibits a gradual increase within 2 h, showing a maximum around 12 μg·g-1, which tends to stabilize after 12 h. MTMC has moderate mobility in dark brown soil. This research has important practical significance for controlling tree diseases and insect pests and protecting the environment.

scholarly journals Erosion Transportation Processes as Influenced by Gully Land Consolidation Projects in Highly Managed Small Watersheds in the Loess Hilly–Gully Region, China

Water ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1540
Author(s):  
Qianqian Ji ◽  
Zhe Gao ◽  
Xingyao Li ◽  
Jian’en Gao ◽  
Gen’guang Zhang ◽  
...  
Keyword(s):  
Similarity Theory ◽  
Design Method ◽  
Simulation Method ◽  
Practical Significance ◽  
Land Consolidation ◽  
Small Watershed ◽  
Flood Peak ◽  
Erosion Area ◽  
The Impact ◽  
Erosion Environment

The Loess Hilly–Gully region (LHGR) is the most serious soil erosion area in the world. For the small watershed with high management in this area, the scientific problem that has been paid attention to in recent years is the impact of the land consolidation project on the erosion environment in the gully region. In this study, the 3D simulation method of vegetation, eroded sediment and pollutant transport was innovated based on the principles of erosion sediment dynamics and similarity theory, and the impacts of GLCP were analyzed on the erosion environment at different scales. The verification results show that the design method and the scale conversion relationship (geometric scale: λl = 100) were reasonable and could simulate the transport process on the complex underlying surface of a small watershed. Compared with untreated watersheds, a significant change was the current flood peak lagging behind the sediment peak. There were two important critical values of GLCP impact on the erosion environment. The erosion transport in HMSW had no change when the proportion was less than 0.85%, and increased obviously when it was greater than 3.3%. The above results have important theoretical and practical significance for watershed simulation and land-use management in HMSW.

scholarly journals Morphological, thermal and mechanical properties of recycled HDPE foams via rotational molding

2021 ◽  
pp. 0021955X2110137
Author(s):  
Yao Dou ◽  
Denis Rodrigue
Keyword(s):  
Cell Density ◽  
Morphological Analysis ◽  
Mechanical Characterization ◽  
Gradual Increase ◽  
Thermal And Mechanical Properties ◽  
Rotational Molding ◽  
Average Cell Size ◽  
Average Cell ◽  
The Impact ◽  
Recycled Hdpe

In this study, foamed recycled high density polyethylene (rHDPE) parts were produced by rotational molding using different concentration (0 to 1% wt.) of a chemical blowing agent (CBA) based on azodicarbonamide. From the samples produced, a complete morphological, thermal and mechanical characterization was performed. The morphological analysis showed a gradual increase in the average cell size, while the cell density firstly increased and then decreased with increasing CBA content. As expected, increasing the CBA content decreased the foam density as well as the thermal conductivity. Although increasing the CBA content decreased both tensile and flexural properties, the impact strength showed a similar trend as the cell density with an optimum CBA content around 0.1% wt. Finally, neat rHDPE samples were also produced by compression molding. The results showed negligible differences between the rotomolded and compression molded properties indicating that optimal rotomolding conditions were selected. These results confirm the possibility of using 100% recycled polymers to produce rotomolded foam parts.

scholarly journals Lipemia in the Plasma Sample Affects Fentanyl Measurements by Means of HPLC-MS2 after Liquid-Liquid Extraction

Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4514
Author(s):  
Marta Tikhomirov ◽  
Tomasz Śniegocki ◽  
Błażej Poźniak
Keyword(s):  
Forensic Toxicology ◽  
Liquid Extraction ◽  
Rabbit Plasma ◽  
Chromatography Method ◽  
Method Performance ◽  
Liquid Liquid Extraction ◽  
Normal Plasma ◽  
Validation Procedure ◽  
Liquid Chromatography Method ◽  
The Impact

Examination of fentanyl levels is frequently performed in certain scientific evaluations and forensic toxicology. It often involves the collection of very variable blood samples, including lipemic plasma or serum. To date, many works have reported the methods for fentanyl detection, but none of them have provided information about the impact on the assay performance caused by an excessive amount of lipids. This aspect may be, however, very important for highly lipophilic drugs like fentanyl. To address this issue, we developed the liquid chromatography method with mass spectrometry detection and utilized it to investigate the impact of lipids presence in rabbit plasma on the analytical method performance and validation. The validation procedure, conducted for normal plasma and lipemic plasma separately, resulted in good selectivity, sensitivity and linearity. The limits of detection and quantification were comparable between the two matrices, being slightly lower in normal plasma (0.005 and 0.015 µg/L) than in lipemic plasma (0.008 and 0.020 µg/L). Liquid–liquid extraction provided a low matrix effect regardless of the lipid levels in the samples (<10%), but pronounced differences were found in the recovery and accuracy. In the normal plasma, this parameter was stable and high (around 100%), but in the lipemic matrix, much more variable and less efficient results were obtained. Nevertheless, this difference had no impact on repeatability and reproducibility. In the present work, we provided reliable, convenient and sensitive method for fentanyl detection in the normal and lipemic rabbit plasma. However, construction of two separate validation curves was necessary to provide adequate results since the liquid-liquid extraction was utilized. Therefore, special attention should be paid during fentanyl quantification that involves lipemic plasma samples purified by this technique.

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